wikidoc - User contributions [en]

Dana syndrome

2012-07-06T15:17:20Z

Aiham Jbeli: ←Redirected page to Vitamin B12 deficiency

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Dana syndrome

2012-07-06T15:16:34Z

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Dissociative drugs

2012-07-06T15:12:56Z

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Christmas Cherry poisoning

2012-07-06T15:11:32Z

Aiham Jbeli: ←Redirected page to Jerusalem cherry

#redirect[[Jerusalem cherry]]

Datura tramonium

2012-07-06T15:07:37Z

Aiham Jbeli: ←Redirected page to Datura

#redirect[[Datura]]

Extreme fatigue

2012-07-06T14:57:05Z

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Bell mania

2012-07-06T14:29:52Z

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Brief psychotic disorder

2012-07-06T14:25:52Z

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Optic nerve lesion

2012-07-06T14:23:44Z

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Retinal ischemia

2012-07-06T14:17:07Z

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Acanthamoeba infection of the central nervous system

2012-07-06T14:00:30Z

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Barbiturate abuse

2012-07-06T13:57:34Z

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Isoniazid toxicity

2012-07-06T13:56:15Z

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Ethchlorvynol withdrawal

2012-07-06T13:53:32Z

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Sodium Monofluoroacetate

2012-07-06T13:50:56Z

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Glaze

2012-07-06T13:49:26Z

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Ammonium Sulfamate

2012-07-06T13:33:10Z

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Marijuana intoxication

2012-07-06T13:30:43Z

Aiham Jbeli: ←Redirected page to Marijuana intoxication (patient information)

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Cocaine withdrawal

2012-07-06T13:28:21Z

Aiham Jbeli: ←Redirected page to Cocaine withdrawal (patient information)

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Cocaine withdrawal

2012-07-06T13:25:49Z

Aiham Jbeli:

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Cocaine withdrawal

2012-07-06T13:25:22Z

Aiham Jbeli:

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Cocaine withdrawal

2012-07-06T13:23:49Z

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Hallucination

2012-07-05T20:39:26Z

Aiham Jbeli: /* In alphabetical orderSailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016 Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts...

'''For patient information click [[Hallucination (patient information)|here]]'''

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==Overview==
A '''hallucination''' is a perception in the absence of a [[stimulus (physiology)|stimulus]] that the person may or may not believe is real (Hallucinations are psychotic symptoms that occur when patients perceive stimuli that do not exist). Hallucinations may occur in any sensory modality—[[visual system|visual]], [[auditory system|auditory]], [[olfaction|olfactory]], [[taste|gustatory]], [[tactition|tactile]], [[proprioception|proprioceptive]], [[equilibrioception|equilibrioceptive]], [[nociception|nociceptive]], [[thermoception|thermoceptive]]. Hallucinations are different from illusions. In an illusory experience, a genuine sensation is attributed to an incorrect cause, misinterpreting a coat hanging on a door to be an intruder or thinking there is water on a hot road, due to the heat rising from the road. A delusional perception is where a genuine perception (ie. correctly sensed and interpreted) is given some additional (and typically bizarre) significance. [[Hypnagogic hallucination]]s and [[hypnopompia|hypnopompic hallucination]]s are considered normal phenomena. Hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up. Hallucinations may also be associated with [[Psychoactive drug|drug]] use (particularly [[Psychedelics, dissociatives and deliriants|hallucinogenic drug]]s), [[sleep deprivation]], psychosis or [[neurological disorder|neurological illness]].

*Hallucinations may involve any of the five senses:
:* Auditory
:* Gustatory
:* Olfactory
:* Tactile
:* Visual
* The most common type of hallucinations are auditory
* Patients may either dismiss the hallucination as being false, or they may identify them to be true

==Prevalence==

Studies have now shown hallucinatory experiences take place across the world. Previous studies, one as early as 1894,<ref>Sidgwick, H., Johnson, A, Myers, FWH et al (1894) Report on the census of hallucinations. ''Proceedings of the Society for Psychical Research'', 34, 25-394. </ref> have reported that approximately 10% of the population experience hallucinations. A recent survey of over 9,000 people<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11166087&dopt=Abstract Ohayon MM. (2000)] Prevalence of hallucinations and their pathological associations in the general population. ''Psychiatry Research'', 97(2-3), 153-64. </ref> reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survey, [[olfactory]] (smell) and [[gustatory]] (taste) hallucinations seem the most common in the general population.

==Auditory hallucinations==

[[Sound|Auditory]] hallucinations, particularly of one or more talking voices, are particularly associated with [[psychosis|psychotic]] disorders such as [[schizophrenia]]. and the presence may have significance in diagnosing these conditions, People not suffering from diagnosable [[mental illness]] may sometimes hear voices as well.<ref>{{cite web | url = http://www.livescience.com/humanbiology/060915_hearing_voices.html | title = Hearing Voices: Some People Like It | last = Thompson | first = Andrea | publisher = LiveScience.com | date = September 15, 2006|accessdate = 2006-11-25 }}</ref> The [[Hearing Voices Movement]] is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucinations include musical hallucinations, where people will hear music playing in their mind, usually songs they are familiar with. This can be caused by [[lesions]] on the [[brain stem]], occurring most often from [[strokes]], but also [[tumors]], sencephalitis, or [[abscesses]].<ref>{{cite web | url = http://www.sciencedaily.com/releases/2000/08/000809065249.htm | title = Rare Hallucinations Make Music In The Mind | publisher = ScienceDaily.com | date = August 9, 2000 | accessdate = 2006-12-31 }}</ref> Recent reports have also mentioned that it is possible to get musical hallucinations from listening to music for long periods of time.

==Visual hallucinations==

===Hypnagogic hallucination===
These hallucinations occur just before falling asleep and affect a surprising number of people in the population. The hallucinations can last from seconds to minutes, all the while the subject usually remains aware of the true nature of the images. These are usually associated with [[narcolepsy]], but can also affect normal minds. Hypnagogic hallucinations are sometimes associated with brainstem abnormalities, but this is rare.<ref name=manford> [http://brain.oxfordjournals.org/cgi/content/abstract/121/10/1819 Manford and Andermann (1998)] Complex visual hallucinations. Clinical and Neurobiological insights''Brain'', 121(10), 1819-1840.</ref>

===Peduncular hallucinosis===
Peduncular means pertaining to the [[peduncle]], which is a neural tract running to and from the [[pons]] on the [[brain stem]]. These hallucinations occur most often in the evenings, but not during drowsiness as in the case of hypnagogic hallucination. The subject is usually fully conscious and can interact with the hallucinatory characters for extended periods of time. As in the case of [[hypnagogic hallucinations]], insight into the nature of the images remains intact. The false images can occur in any part of the visual field, and are rarely [[wikt:polymodal|polymodal]].<ref name=manford/>

===Delirium tremens===
{{main|Delerium tremens}}
One of the most enigmatic forms of visual hallucinations are the highly variable, possibly polymodal [[delirium tremens]]. Individuals suffering from delerium tremens may be agitated and confused, especially in the later stages of this disease. Insight is gradually reduced with the progression of this disorder. Sleep is disturbed and occurs for a shorter period of time, with [[REM overflow]].<ref name=manford/>

===Parkinson's disease and Lewy body dementia===
[[Parkinson's disease]] is linked with [[Dementia with Lewy bodies|Lewy body dementia]] for their similar hallucinatory symptoms. The symptoms strike during the evening in any part of the visual field and are rarely polymodal. The segue into hallucinations may start with illusions<ref>[http://www.nytimes.com/2006/02/14/health/14case.html?ex=1151121600&en=04560d31e7926bee&ei=5070 Mark Derr (2006)] Marilyn and Me, "The New York Times" Feb. 14th, 2006 </ref> where sensory perception is greatly distorted, but no novel sensory information is present. These typically last for several minutes, during which time the subject may be either conscious and normal or drowsy/inaccessible. Insight into these hallucinations is usually preserved and [[REM sleep]] is usually reduced. Parkinson's disease is usually associated with a degraded [[substantia nigra]] pars compacta, but recent evidence suggests that PD affects a number of sites in the brain. Some places of noted degradation include the median raphe nuclei, the noradrenergic parts of the locus coeruleus and the [[cholinergic]] neurons in the parabrachial and pedunculopontine nuclei of the [[tegmentum]].<ref name=manford/>

===Migraine coma===
This type of hallucination is usually experienced during the recovery from a comatose state. The migraine coma can last for up to two days and a state of depression is sometimes comorbid. The hallucinations occur during states of full consciousness and insight into the hallucinatory nature of the images is preserved. It has been noted that ataxic lesions accompany the migraine coma.<ref name=manford/>

===Charles Bonnet syndrome===
[[Charles Bonnet syndrome]] is the name given to visual hallucinations experienced by blind patients. The hallucinations can usually be dispersed by opening or closing the eyelids until the visual images disappear. The hallucinations usually occur during the morning or evening, but are not dependent on low light conditions. These prolonged hallucinations usually do not disturb the patients very much as they are aware that they are hallucinating.<ref name=manford/>

===Focal epilepsy===
The visual hallucinations from focal epilepsy are characterized by being brief, and stereotyped. They are usually localized to one part of the visual field and last only a few seconds. Other epileptic features may present themselves between visual episodes. Consciousness is usually impaired in some way, but nevertheless insight into the hallucination is preserved. Usually this type of focal epilepsy is caused by a lesion in the posterior temporoparietal.<ref name=manford/>

==Tactile hallucinations==

Can be associated with substance use, such as someone who feels bugs crawling on them after a prolonged period of [[cocaine]] use.

==Scientific explanations==
Various theories have been put forward to explain the occurrence of hallucinations. When [[psychodynamic]] ([[Freud]]ian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes, thoughts and wants. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the [[brain]]. With reference to mental illness, the function (or dysfunction) of the [[neurotransmitter]] [[dopamine]] is thought to be particularly important.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505794&dopt=Abstract Kapur S. (2003)] Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. ''American Journal of Psychiatry'', 160(1), 13-23. </ref>
[[Psychology|Psychological]] research has argued that hallucinations may result from biases in what are known as [[metacognition|metacognitive]] abilities.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2404293&dopt=Abstract Bentall RP. (1990)] The illusion of reality: a review and integration of psychological research on hallucinations. ''Psychological Bulletin'', 107(1), 82-95. </ref> These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, [[memory|memories]], [[belief]]s and [[thought]]s). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences. Projection of an internal state or a person's own reaction to another may arise in the form of hallucinations, especially auditory hallucinations. A few scientists have argued that such hallucinations may be the result of other conscious thoughts.

==Stages of a hallucination==
#Emergence of surprising or warded-off memory or [[fantasy (psychology)|fantasy]] images <ref name=horowitz>Horowitz, Mardi J., M.D. “Hallucinations: An Information Processing Approach." In Siegel, Ronald K., Ph. D. and L. J. West, eds. ''Hallucinations: Behavior, Experience and Theory'' (1975). New York: John Wiley.</ref>
#Frequent reality checks <ref name=horowitz />
#Last vestige of insight as hallucinations become “real” <ref name=horowitz />
#Fantasy and distortion elaborated upon and confused with actual perception <ref name=horowitz />
#Internal-external boundaries destroyed and possible pantheistic experience <ref name=horowitz />

==Diagnosis==

=== History and Symptoms ===
* Timing of hallucinations
* Suicidal/homicidal ideations
* Drug regimen
* Work with psychiatrist (if patient cannot communicate mental and physical history)

=== Laboratory Findings ===
* [[Complete blood count]] ([[CBC]])
* [[Glucose]]
* [[Calcium]]
* [[Albumin]]
* [[Alkaline phosphatase]]
* [[Blood urea nitrogen]] ([[BUN]])/[[creatinine]]
* [[Liver function tests]] ([[LFT]]s)
* [[Magnesium]]
* [[Phosphate]]
* [[Toxicology]] screen
* [[Urinalysis]]
* [[Pulse oximetry]]
* Drug levels
* [[Folate levels]]
* [[Vitamin B12]]
* [[Antinuclear antibody]] ([[ANA]])
* [[Heavy metal]] screen
* [[Ammonia]]

=== Electrolyte and Biomarker Studies ===

* Electrolytes

=== Chest X Ray ===
* [[Chest X-ray]] (infectious etiologies)

=== Other Imaging Findings ===
* [[Electroencephalogram]] ([[EEG]])

=== Other Diagnostic Studies ===
* [[Lumbar puncture]]

== Differential Diagnosis ==

===Common Causes<ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>===

* Alcohol withdrawal
* [[Bipolar Disorder]]
* Central nervous system (CNS) infections
* [[Delirium]]
* [[Dementia]]
* [[Encephalitis]]
* Hallucinogenic syndromes (drug-induced)
* Heavy metal ingestion
* Lewy Body Dementia
* Mass lesions
* Occipital lobe injury
* Postpartum major depression
* [[Post Traumatic Stress Disorder|Post-Traumatic Stress Disorder]]
* Psychotic disorder
* Schizoaffective disorder
* [[Schizophrenia]]
* Schizophreniform disorder
* [[Seizures]]
* [[Systemic Lupus Erythematosus]]

===Organ based===
{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Chemical / poisoning'''
|bgcolor="Beige"| [[Amanita muscaria]], [[Alcohol Withdrawal]], [[Carbon monoxide poisoning]], [[Alcoholism]], [[Mescaline]], [[Lysergic acid diethylamide]], [[Jenkem]], [[Nitrogen narcosis]], [[Laudanum]], [[Incapacitating agent]], [[Solanine]], [[Cocaine withdrawal ]], [[Bufotenin]], [[2C-T-2]], [[DESOXY]], [[3,4-Methylenedioxyamphetamine]], [[2C-E]], [[Dimethoxyamphetamine]], [[TOM (psychedelic)]], [[TOET (psychedelic)]], [[Substance D]], [[Ergot]], [[Henbane]], [[Phencyclidine]], [[Muscimol]], [[Datura tramonium]], [[Deadly nightshade]], [[Datura inoxia]], [[Datura wrightii]], [[Thujone]], [[5-Hydroxytryptophan]], [[2C-B]], [[2C-T-7]], [[Benzylpiperazine]], [[Candyflipping]], [[Mercury(II) chloride]], [[Ibotenic acid]], [[Khat]], [[PMA]], [[Amphetamine]], [[Psychedelic plants]], [[Psilocybin mushrooms]], [[Datura metel]], [[4-Acetoxy-DIPT]], [[Hallucinogen persisting perception disorder]], [[Formication]], [[Ergotism]], [[Ichthyoallyeinotoxism]], [[Abrin]], [[Delirium tremens]], [[Ascomycota]], [[Hawaiian baby woodrose]], [[Solanaceae]], [[Cocaine dependence]], [[5-F-AMT]], [[5-MeO-AMT]], [[Diisopropyltryptamine]], [[Dipropyltryptamine]], [[Marijuana intoxication]], [[Cannabis]], [[1,3-Butadiene ]], [[Acrylamide ]], [[Ammonium Sulfamate ]], [[Bromide]], [[Ether ]], [[Gasoline]], [[Glaze]], [[Sodium Monofluoroacetate ]], [[Solder]], [[Thallium]], [[Trichloroethane ]], [[Christmas Cherry poisoning]]

|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Procainamide ]], [[Alatrofloxacin Injection ]], [[Lomotil]], [[Fluphenazine ]], [[Acyclovir ]], [[Cefaclor]], [[Morphine Oral ]], [[Pentamidine Isethionate Injection ]], [[Alfentanil Hydrochloride Injection ]], [[Atropine]], [[Aspirin]], [[Zolpidem ]], [[Zaleplon ]], [[Voriconazole ]], [[Venlafaxine]], [[Trovafloxacin ]], [[Trihexyphenidyl ]], [[Trifluoperazine Oral ]], [[Tolterodine ]], [[Atomoxetine]], [[Tolcapone ]], [[Thiothixene Oral ]], [[Thioridazine ]], [[Benztropine Mesylate Oral ]], [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]], [[Bupropion]], [[Butorphanol Injection ]], [[Chlorpromazine ]], [[Clarithromycin]], [[Clomipramine ]], [[Dexmethylphenidate]], [[Dextroamphetamine]], [[Dextromethorphan]], [[Dimenhydrinate]], [[Efavirenz ]], [[Entacapone ]], [[Eszopiclone ]], [[Fluconazole ]], [[Flurazepam ]], [[Galantamine ]], [[Gatifloxacin ]], [[Gatifloxacin Injection ]], [[Haloperidol Oral ]], [[Ifosfamide ]], [[Ketorolac]], [[Levodopa]], [[Lithium ]], [[Loxapine Oral ]], [[Mefloquine ]], [[Memantine]], [[Methylphenidate Transdermal ]], [[Mirtazapine]], [[Modafinil ]], [[Nabilone ]], [[Nalbuphine injection ]], [[Naltrexone ]], [[Orphenadrine ]], [[Oxybutynin ]], [[Pemoline ]], [[Pergolide ]], [[Perphenazine oral ]], [[Phenelzine ]], [[Pramipexole ]], [[Prochlorperazine ]], [[Procyclidine ]], [[Promethazine ]], [[Ropinirole ]], [[Scopolamine patch ]], [[Selegiline ]], [[Sertraline]], [[Sodium oxybate ]], [[Solifenacin ]], [[Sufentanil citrate injection ]], [[Procyclidine hydrochloride]], [[3-Quinuclidinyl benzilate]], [[Ketamine]], [[Nalmefene]], [[Dezocine]], [[Dimethyltryptamine]], [[Scopolamine]], [[Methamphetamine]], [[Morphine]], [[Alprazolam]], [[Beta-blockers]], [[Buspirone]], [[Hydroxyzine]], [[Imipramine]], [[Lorazepam]], [[Phentermine]], [[Temazepam]], [[Tizanidine]], [[Triazolam]], [[Ethchlorvynol withdrawal ]], [[Serotonin syndrome]], [[Psychotomimetic]], [[Benzodiazepine withdrawal syndrome]], [[Ziconotide]], [[Diphenhydramine]], [[Dizocilpine]], [[NMDA receptor antagonist]], [[Pentazocine]], [[Opioid]], [[Ketazocine]], [[Valproate semisodium]], [[Ephedrine]], [[SSRI discontinuation syndrome]], [[Baclofen]], [[Flucytosine]], [[Oxamniquine]], [[Aciclovir]], [[Nitrazepam]], [[Loprazolam]], [[Lormetazepam]], [[Biperiden]], [[Clozapine]], [[Dantrolene]], [[Tricyclic antidepressant]], [[Zopiclone]], [[Propylhexedrine]], [[Dissociative drugs]], [[Toxidrome]], [[Tifluadom]], [[Phenazocine]], [[Etoxadrol]], [[Cabergoline]], [[Dexedrine overdose ]], [[Appian-Plutarch syndrome]], [[Isoniazid toxicity]], [[Ritalin overdose]], [[Steroids]], [[Barbiturate abuse]]

|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| [[Myxedematous psychosis]], [[Adrenal adenoma]], [[Adrenal Cancer ]], [[Adrenal gland hyperfunction]], [[Hyperadrenalism]], [[Cushing's Syndrome]], [[Adrenal incidentaloma]],

|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| [[Gluten-sensitive enteropathy associated conditions]]

|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| [[Creutzfeldt-Jakob Disease]], [[Rabies]], [[Acanthamoeba infection of the central nervous system]], [[Trypanosomiasis ]], [[Granulomatous amebic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Narcolepsy]], [[Encephalopathy]], [[Acute Disseminated Encephalomyelitis]], [[Migraine]], [[Dementia]], [[Delirium]], [[Complex partial seizure]], [[Arachnoid cyst]], [[Charles Bonnet syndrome]], [[Phantom eye syndrome]], [[Coats disease]], [[Entoptic phenomenon]], [[Closed-eye hallucination]], [[Cortical blindness]], [[High altitude cerebral edema]], [[Cerebral edema]], [[False memory]], [[Sleep deprivation]], [[Morvan's syndrome]], [[Fatal familial insomnia]], [[Endaural phenomena]], [[Parkinson plus syndrome]], [[Dementia with Lewy bodies]], [[Peduncular hallucinosis]], [[Temporal lobe epilepsy]], [[Aura (symptom)]], [[Parkinson's disease]], [[Traumatic brain injury]], [[Sensory deprivation]], [[Brain tumor]], [[Binswanger's disease]], [[Stroke]], [[Dana syndrome]], [[Lhermitte-McAlpine syndrome]], [[Autoimmune limbic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Nutritional / Metabolic'''
|bgcolor="Beige"| [[Porphyria]], [[Variegate porphyria]], [[Korsakoff's psychosis]], [[Nyssen-Van Bogaert syndrome ]]

|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Opthalmologic'''
|bgcolor="Beige"| [[Cataracts]], [[Glaucoma]], [[Retinal ischemia ]], [[Optic nerve lesion]]

|-
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
|bgcolor="Beige"| [[Pseudoephedrine]], [[Caffeine]], [[Mazindol]]

|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Schizophrenia]], [[Hypnagogia]], [[Kleine-Levin syndrome]], [[Clinical lycanthropy]], [[Paris syndrome]], [[Homosexual panic]], [[Ganser syndrome]], [[Psychosis]], [[Psychotic depression]], [[Clinical depression]], [[Stendhal syndrome]], [[Alice in Wonderland syndrome]], [[Delusional disorder]], [[Oneirophrenia]], [[Postnatal depression]], [[Avolition]], [[Disorganized schizophrenia]], [[Schizoaffective disorder]], [[Mania]], [[Schizotypal personality disorder]], [[Brief psychotic disorder]], [[Bipolar disease]], [[Grief ]], [[Bell mania]], [[Briquet syndrome]], [[Schizoid personality disorder]]

|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
|bgcolor="Beige"| [[Hypercalcemia]], [[Hypomagnesemia]], [[Kidney failure]]

|-
|-bgcolor="LightSteelBlue"
| '''Rheum / Immune / Allergy'''
|bgcolor="Beige"| Systemic Lupus Erythematosus

|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| [[Visual snow]], [[Apparitional experience]], [[Hallucinations in the sane]], [[Extreme fatigue]], [[Extreme physical stress]], [[Dehydration ]]

|-
|}

===In alphabetical order<ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>===
{{MultiCol}}
* [[1,3-Butadiene ]]
* [[2C-B]]
* [[2C-E]]
* [[2C-T-2]]
* [[2C-T-7]]
* [[3,4-Methylenedioxyamphetamine]]
* [[3-Quinuclidinyl benzilate]]
* [[4-Acetoxy-DIPT]]
* [[5-F-AMT]]
* [[5-Hydroxytryptophan]]
* [[5-MeO-AMT]]
* [[Abrin]]
* [[Acanthamoeba infection of the central nervous system]]
* [[Aciclovir]]
* [[Acrylamide ]]
* [[Acute Disseminated Encephalomyelitis]]
* [[Acyclovir ]]
* [[Adrenal adenoma]]
* [[Adrenal Cancer ]]
* [[Adrenal gland hyperfunction]]
* [[Adrenal incidentaloma]]
* [[Alatrofloxacin Injection ]]
* [[Alcohol Withdrawal]]
* [[Alcoholism]]
* [[Alfentanil Hydrochloride Injection ]]
* [[Alice in Wonderland syndrome]]
* [[Alprazolam]]
* [[Amanita muscaria]]
* [[Ammonium Sulfamate ]]
* [[Amphetamine]]
* [[Apparitional experience]]
* [[Appian-Plutarch syndrome]]
* [[Arachnoid cyst]]
* [[Ascomycota]]
* [[Aspirin]]
* [[Atomoxetine]]
* [[Atropine]]
* [[Aura (symptom)]]
* [[Autoimmune limbic encephalitis]]
* [[Avolition]]
* [[Baclofen]]
* [[Barbiturate abuse]]
* [[Bell mania]]
* [[Benzodiazepine withdrawal syndrome]]
* [[Benztropine Mesylate Oral ]]
* [[Benzylpiperazine]]
* [[Beta-blockers]]
* [[Binswanger's disease]]
* [[Biperiden]]
* [[Bipolar disease]]
* [[Brain tumor]]
* [[Brief psychotic disorder]]
* [[Briquet syndrome]]
* [[Bromide]]
* [[Bufotenin]]
* [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]]
* [[Bupropion]]
* [[Buspirone]]
* [[Butorphanol Injection ]]
* [[Cabergoline]]
* [[Caffeine]]
* [[Candyflipping]]
* [[Cannabis]]
* [[Carbon monoxide poisoning]]
* [[Cataracts]]
* [[Cefaclor]]
* [[Cerebral edema]]
* [[Charles Bonnet syndrome]]
* [[Chlorpromazine ]]
* [[Christmas Cherry poisoning]]
* [[Clarithromycin]]
* [[Clinical depression]]
* [[Clinical lycanthropy]]
* [[Clomipramine ]]
* [[Closed-eye hallucination]]
* [[Clozapine]]
* [[Coats disease]]
* [[Cocaine dependence]]
* [[Cocaine withdrawal ]]
* [[Complex partial seizure]]
* [[Cortical blindness]]
* [[Creutzfeldt-Jakob Disease]]
* [[Cushing's Syndrome]]
* [[Dana syndrome]]
* [[Dantrolene]]
* [[Datura inoxia]]
* [[Datura metel]]
* [[Datura stramonium]]
* [[Datura wrightii]]
* [[Deadly nightshade]]
* [[Dehydration ]]
* [[Delirium tremens]]
* [[Delirium]]
* [[Delusional disorder]]
* [[Dementia with Lewy bodies]]
* [[Dementia]]
* [[DESOXY]]
* [[Dexedrine overdose ]]
* [[Dexmethylphenidate]]
{{ColBreak}}
* [[Dexoxadrol]]
* [[Dextroamphetamine]]
* [[Dextromethorphan]]
* [[Dezocine]]
* [[Diisopropyltryptamine]]
* [[Dimenhydrinate]]
* [[Dimethoxyamphetamine]]
* [[Dimethyltryptamine]]
* [[Diphenhydramine]]
* [[Dipropyltryptamine]]
* [[Disorganized schizophrenia]]
* [[Dissociative drugs]]
* [[Dizocilpine]]
* [[Efavirenz ]]
* [[Encephalopathy]]
* [[Endaural phenomena]]
* [[Entacapone ]]
* [[Entoptic phenomenon]]
* [[Ephedrine]]
* [[Ergot]]
* [[Ergotism]]
* [[Eszopiclone ]]
* [[Ethchlorvynol withdrawal ]]
* [[Ether ]]
* [[Etoxadrol]]
* [[Extreme fatigue]]
* [[Extreme physical stress]]
* [[False memory]]
* [[Fatal familial insomnia]]
* [[Fluconazole ]]
* [[Flucytosine]]
* [[Fluphenazine ]]
* [[Flurazepam ]]
* [[Formication]]
* [[Galantamine ]]
* [[Ganser syndrome]]
* [[Gasoline]]
* [[Gatifloxacin ]]
* [[Gatifloxacin Injection ]]
* [[Glaucoma]]
* [[Glaze]]
* [[Gluten-sensitive enteropathy associated conditions]]
* [[Granulomatous amebic encephalitis]]
* [[Grief ]]
* [[Hallucinations in the sane]]
* [[Hallucinogen persisting perception disorder]]
* [[Haloperidol Oral ]]
* [[Hawaiian baby woodrose]]
* [[Henbane]]
* [[High altitude cerebral edema]]
* [[Homosexual panic]]
* [[Hydroxyzine]]
* [[Hyperadrenalism]]
* [[Hypercalcemia]]
* [[Hypnagogia]]
* [[Hypomagnesemia]]
* [[Ibotenic acid]]
* [[Ichthyoallyeinotoxism]]
* [[Ifosfamide ]]
* [[Imipramine]]
* [[Incapacitating agent]]
* [[Isoniazid toxicity]]
* [[Jenkem]]
* [[Ketamine]]
* [[Ketazocine]]
* [[Ketorolac]]
* [[Khat]]
* [[Kidney failure]]
* [[Kleine-Levin syndrome]]
* [[Korsakoff's psychosis]]
* [[Laudanum]]
* [[Levodopa]]
* [[Lhermitte-McAlpine syndrome]]
* [[Lithium ]]
* [[Lomotil]]
* [[Loprazolam]]
* [[Lorazepam]]
* [[Lormetazepam]]
* [[Loxapine Oral ]]
* [[Lysergic acid diethylamide]]
* [[Mania]]
* [[Marijuana intoxication]]
* [[Mazindol]]
* [[Mefloquine ]]
* [[Memantine]]
* [[Mercury(II) chloride]]
* [[Mescaline]]
* [[Methamphetamine]]
* [[Methylphenidate Transdermal ]]
* [[Migraine]]
* [[Mirtazapine]]
* [[Modafinil ]]
* [[Morphine Oral ]]
* [[Morphine]]
* [[Morvan's syndrome]]
* [[Muscimol]]
* [[Myxedematous psychosis]]
* [[Nabilone ]]
* [[Nalbuphine injection ]]
* [[Nalmefene]]
{{ColBreak}}
* [[Naltrexone ]]
* [[Narcolepsy]]
* [[Nitrazepam]]
* [[Nitrogen narcosis]]
* [[NMDA receptor antagonist]]
* [[Nyssen-Van Bogaert syndrome ]]
* [[Oneirophrenia]]
* [[Opioid]]
* [[Optic nerve lesion]]
* [[Orphenadrine ]]
* [[Oxamniquine]]
* [[Oxybutynin ]]
* [[Paris syndrome]]
* [[Parkinson plus syndrome]]
* [[Parkinson's disease]]
* [[Peduncular hallucinosis]]
* [[Pemoline ]]
* [[Pentamidine Isethionate Injection ]]
* [[Pentazocine]]
* [[Pergolide ]]
* [[Perphenazine oral ]]
* [[Phantom eye syndrome]]
* [[Phenazocine]]
* [[Phencyclidine]]
* [[Phenelzine ]]
* [[Phentermine]]
* [[PMA]]
* [[Porphyria]]
* [[Postnatal depression]]
* [[Pramipexole ]]
* [[Procainamide ]]
* [[Prochlorperazine ]]
* [[Procyclidine ]]
* [[Procyclidine hydrochloride]]
* [[Promethazine ]]
* [[Propylhexedrine]]
* [[Pseudoephedrine]]
* [[Psilocybin mushrooms]]
* [[Psychedelic plants]]
* [[Psychosis]]
* [[Psychotic depression]]
* [[Psychotomimetic]]
* [[Rabies]]
* [[Retinal ischemia ]]
* [[Ritalin overdose]]
* [[Ropinirole ]]
* [[Schizoaffective disorder]]
* [[Schizoid personality disorder]]
* [[Schizophrenia]]
* [[Schizotypal personality disorder]]
* [[Scopolamine patch ]]
* [[Scopolamine]]
* [[Selegiline ]]
* [[Sensory deprivation]]
* [[Serotonin syndrome]]
* [[Sertraline]]
* [[Sleep deprivation]]
* [[Sodium Monofluoroacetate ]]
* [[Sodium oxybate ]]
* [[Solanaceae]]
* [[Solanine]]
* [[Solder]]
* [[Solifenacin ]]
* [[SSRI discontinuation syndrome]]
* [[Stendhal syndrome]]
* [[Steroids]]
* [[Stroke]]
* [[Substance D]]
* [[Sufentanil citrate injection ]]
* [[Systemic Lupus Erythematosus]]
* [[Temazepam]]
* [[Temporal lobe epilepsy]]
* [[Thallium]]
* [[Thioridazine ]]
* [[Thiothixene Oral ]]
* [[Thujone]]
* [[Tifluadom]]
* [[Tizanidine]]
* [[TOET (psychedelic)]]
* [[Tolcapone ]]
* [[Tolterodine ]]
* [[TOM (psychedelic)]]
* [[Toxidrome]]
* [[Traumatic brain injury]]
* [[Triazolam]]
* [[Trichloroethane ]]
* [[Tricyclic antidepressant]]
* [[Trifluoperazine Oral ]]
* [[Trihexyphenidyl ]]
* [[Trovafloxacin ]]
* [[Trypanosomiasis ]]
* [[Valproate semisodium]]
* [[Variegate porphyria]]
* [[Venlafaxine]]
* [[Visual snow]]
* [[Voriconazole ]]
* [[Zaleplon ]]
* [[Ziconotide]]
* [[Zolpidem ]]
* [[Zopiclone]]
{{EndMultiCol}}

== Treatment ==
* Treat underlying etiologies

=== Acute Pharmacotherapies ===
* [[Antipsychotic drugs]]
* [[Benzodiazepine]]s

== See also ==
* [[Apparitional experience]]
* [[Closed-eye hallucination]]
* [[Delusion]]
* [[Dimethyltryptamine]]
* [[Dream]]
* [[Focal seizures]]
* [[Folie à deux]]
* Form constant
* [[Hallucinations in the sane]]
* [[Illusion]]
* Imaginary friend
* [[Phantom eye syndrome]]
* [[Psychedelics, dissociatives and deliriants|Hallucinogenic drug]]
* [[Psychosis]]
* [[Salvia divinorum]]
* Simulated reality

== References ==
{{reflist|2}}

{{SIB}}
{{WH}}
{{WS}}

[[Category:Signs and symptoms]]
[[Category:Psychiatry]]
[[Category:Mature chapter]]

[[cs:Halucinace]]
[[da:Hallucination]]
[[de:Halluzination]]
[[et:Hallutsinatsioon]]
[[es:Alucinación]]
[[fr:Hallucination]]
[[ga:Bréagchéadfa]]
[[it:Allucinazione]]
[[ku:Hallûsînasyon]]
[[he:הזיה]]
[[ka:ჰალუცინაცია]]
[[lb:Halluzinatioun]]
[[lt:Haliucinacija]]
[[hu:Hallucináció]]
[[mk:Халуцинација]]
[[nl:Hallucinatie]]
[[ja:幻覚]]
[[no:Hallusinasjon]]
[[pt:Alucinação]]
[[ru:Галлюцинация]]
[[simple:Hallucination]]
[[sk:Halucinácia]]
[[sl:Halucinacija]]
[[sr:Халуцинација]]
[[pl:Halucynacja]]
[[tr:Halüsinasyon]]
[[fi:Hallusinaatio]]
[[sv:Hallucination]]
[[ur:خطاۓ حس]]
[[zh:幻觉]]

Hallucination

2012-07-05T20:34:34Z

'''For patient information click [[Hallucination (patient information)|here]]'''

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MedlinePlus = 003258 |
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{{SI}}
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==Overview==
A '''hallucination''' is a perception in the absence of a [[stimulus (physiology)|stimulus]] that the person may or may not believe is real (Hallucinations are psychotic symptoms that occur when patients perceive stimuli that do not exist). Hallucinations may occur in any sensory modality—[[visual system|visual]], [[auditory system|auditory]], [[olfaction|olfactory]], [[taste|gustatory]], [[tactition|tactile]], [[proprioception|proprioceptive]], [[equilibrioception|equilibrioceptive]], [[nociception|nociceptive]], [[thermoception|thermoceptive]]. Hallucinations are different from illusions. In an illusory experience, a genuine sensation is attributed to an incorrect cause, misinterpreting a coat hanging on a door to be an intruder or thinking there is water on a hot road, due to the heat rising from the road. A delusional perception is where a genuine perception (ie. correctly sensed and interpreted) is given some additional (and typically bizarre) significance. [[Hypnagogic hallucination]]s and [[hypnopompia|hypnopompic hallucination]]s are considered normal phenomena. Hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up. Hallucinations may also be associated with [[Psychoactive drug|drug]] use (particularly [[Psychedelics, dissociatives and deliriants|hallucinogenic drug]]s), [[sleep deprivation]], psychosis or [[neurological disorder|neurological illness]].

*Hallucinations may involve any of the five senses:
:* Auditory
:* Gustatory
:* Olfactory
:* Tactile
:* Visual
* The most common type of hallucinations are auditory
* Patients may either dismiss the hallucination as being false, or they may identify them to be true

==Prevalence==

Studies have now shown hallucinatory experiences take place across the world. Previous studies, one as early as 1894,<ref>Sidgwick, H., Johnson, A, Myers, FWH et al (1894) Report on the census of hallucinations. ''Proceedings of the Society for Psychical Research'', 34, 25-394. </ref> have reported that approximately 10% of the population experience hallucinations. A recent survey of over 9,000 people<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11166087&dopt=Abstract Ohayon MM. (2000)] Prevalence of hallucinations and their pathological associations in the general population. ''Psychiatry Research'', 97(2-3), 153-64. </ref> reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survey, [[olfactory]] (smell) and [[gustatory]] (taste) hallucinations seem the most common in the general population.

==Auditory hallucinations==

[[Sound|Auditory]] hallucinations, particularly of one or more talking voices, are particularly associated with [[psychosis|psychotic]] disorders such as [[schizophrenia]]. and the presence may have significance in diagnosing these conditions, People not suffering from diagnosable [[mental illness]] may sometimes hear voices as well.<ref>{{cite web | url = http://www.livescience.com/humanbiology/060915_hearing_voices.html | title = Hearing Voices: Some People Like It | last = Thompson | first = Andrea | publisher = LiveScience.com | date = September 15, 2006|accessdate = 2006-11-25 }}</ref> The [[Hearing Voices Movement]] is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucinations include musical hallucinations, where people will hear music playing in their mind, usually songs they are familiar with. This can be caused by [[lesions]] on the [[brain stem]], occurring most often from [[strokes]], but also [[tumors]], sencephalitis, or [[abscesses]].<ref>{{cite web | url = http://www.sciencedaily.com/releases/2000/08/000809065249.htm | title = Rare Hallucinations Make Music In The Mind | publisher = ScienceDaily.com | date = August 9, 2000 | accessdate = 2006-12-31 }}</ref> Recent reports have also mentioned that it is possible to get musical hallucinations from listening to music for long periods of time.

==Visual hallucinations==

===Hypnagogic hallucination===
These hallucinations occur just before falling asleep and affect a surprising number of people in the population. The hallucinations can last from seconds to minutes, all the while the subject usually remains aware of the true nature of the images. These are usually associated with [[narcolepsy]], but can also affect normal minds. Hypnagogic hallucinations are sometimes associated with brainstem abnormalities, but this is rare.<ref name=manford> [http://brain.oxfordjournals.org/cgi/content/abstract/121/10/1819 Manford and Andermann (1998)] Complex visual hallucinations. Clinical and Neurobiological insights''Brain'', 121(10), 1819-1840.</ref>

===Peduncular hallucinosis===
Peduncular means pertaining to the [[peduncle]], which is a neural tract running to and from the [[pons]] on the [[brain stem]]. These hallucinations occur most often in the evenings, but not during drowsiness as in the case of hypnagogic hallucination. The subject is usually fully conscious and can interact with the hallucinatory characters for extended periods of time. As in the case of [[hypnagogic hallucinations]], insight into the nature of the images remains intact. The false images can occur in any part of the visual field, and are rarely [[wikt:polymodal|polymodal]].<ref name=manford/>

===Delirium tremens===
{{main|Delerium tremens}}
One of the most enigmatic forms of visual hallucinations are the highly variable, possibly polymodal [[delirium tremens]]. Individuals suffering from delerium tremens may be agitated and confused, especially in the later stages of this disease. Insight is gradually reduced with the progression of this disorder. Sleep is disturbed and occurs for a shorter period of time, with [[REM overflow]].<ref name=manford/>

===Parkinson's disease and Lewy body dementia===
[[Parkinson's disease]] is linked with [[Dementia with Lewy bodies|Lewy body dementia]] for their similar hallucinatory symptoms. The symptoms strike during the evening in any part of the visual field and are rarely polymodal. The segue into hallucinations may start with illusions<ref>[http://www.nytimes.com/2006/02/14/health/14case.html?ex=1151121600&en=04560d31e7926bee&ei=5070 Mark Derr (2006)] Marilyn and Me, "The New York Times" Feb. 14th, 2006 </ref> where sensory perception is greatly distorted, but no novel sensory information is present. These typically last for several minutes, during which time the subject may be either conscious and normal or drowsy/inaccessible. Insight into these hallucinations is usually preserved and [[REM sleep]] is usually reduced. Parkinson's disease is usually associated with a degraded [[substantia nigra]] pars compacta, but recent evidence suggests that PD affects a number of sites in the brain. Some places of noted degradation include the median raphe nuclei, the noradrenergic parts of the locus coeruleus and the [[cholinergic]] neurons in the parabrachial and pedunculopontine nuclei of the [[tegmentum]].<ref name=manford/>

===Migraine coma===
This type of hallucination is usually experienced during the recovery from a comatose state. The migraine coma can last for up to two days and a state of depression is sometimes comorbid. The hallucinations occur during states of full consciousness and insight into the hallucinatory nature of the images is preserved. It has been noted that ataxic lesions accompany the migraine coma.<ref name=manford/>

===Charles Bonnet syndrome===
[[Charles Bonnet syndrome]] is the name given to visual hallucinations experienced by blind patients. The hallucinations can usually be dispersed by opening or closing the eyelids until the visual images disappear. The hallucinations usually occur during the morning or evening, but are not dependent on low light conditions. These prolonged hallucinations usually do not disturb the patients very much as they are aware that they are hallucinating.<ref name=manford/>

===Focal epilepsy===
The visual hallucinations from focal epilepsy are characterized by being brief, and stereotyped. They are usually localized to one part of the visual field and last only a few seconds. Other epileptic features may present themselves between visual episodes. Consciousness is usually impaired in some way, but nevertheless insight into the hallucination is preserved. Usually this type of focal epilepsy is caused by a lesion in the posterior temporoparietal.<ref name=manford/>

==Tactile hallucinations==

Can be associated with substance use, such as someone who feels bugs crawling on them after a prolonged period of [[cocaine]] use.

==Scientific explanations==
Various theories have been put forward to explain the occurrence of hallucinations. When [[psychodynamic]] ([[Freud]]ian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes, thoughts and wants. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the [[brain]]. With reference to mental illness, the function (or dysfunction) of the [[neurotransmitter]] [[dopamine]] is thought to be particularly important.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505794&dopt=Abstract Kapur S. (2003)] Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. ''American Journal of Psychiatry'', 160(1), 13-23. </ref>
[[Psychology|Psychological]] research has argued that hallucinations may result from biases in what are known as [[metacognition|metacognitive]] abilities.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2404293&dopt=Abstract Bentall RP. (1990)] The illusion of reality: a review and integration of psychological research on hallucinations. ''Psychological Bulletin'', 107(1), 82-95. </ref> These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, [[memory|memories]], [[belief]]s and [[thought]]s). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences. Projection of an internal state or a person's own reaction to another may arise in the form of hallucinations, especially auditory hallucinations. A few scientists have argued that such hallucinations may be the result of other conscious thoughts.

==Stages of a hallucination==
#Emergence of surprising or warded-off memory or [[fantasy (psychology)|fantasy]] images <ref name=horowitz>Horowitz, Mardi J., M.D. “Hallucinations: An Information Processing Approach." In Siegel, Ronald K., Ph. D. and L. J. West, eds. ''Hallucinations: Behavior, Experience and Theory'' (1975). New York: John Wiley.</ref>
#Frequent reality checks <ref name=horowitz />
#Last vestige of insight as hallucinations become “real” <ref name=horowitz />
#Fantasy and distortion elaborated upon and confused with actual perception <ref name=horowitz />
#Internal-external boundaries destroyed and possible pantheistic experience <ref name=horowitz />

==Diagnosis==

=== History and Symptoms ===
* Timing of hallucinations
* Suicidal/homicidal ideations
* Drug regimen
* Work with psychiatrist (if patient cannot communicate mental and physical history)

=== Laboratory Findings ===
* [[Complete blood count]] ([[CBC]])
* [[Glucose]]
* [[Calcium]]
* [[Albumin]]
* [[Alkaline phosphatase]]
* [[Blood urea nitrogen]] ([[BUN]])/[[creatinine]]
* [[Liver function tests]] ([[LFT]]s)
* [[Magnesium]]
* [[Phosphate]]
* [[Toxicology]] screen
* [[Urinalysis]]
* [[Pulse oximetry]]
* Drug levels
* [[Folate levels]]
* [[Vitamin B12]]
* [[Antinuclear antibody]] ([[ANA]])
* [[Heavy metal]] screen
* [[Ammonia]]

=== Electrolyte and Biomarker Studies ===

* Electrolytes

=== Chest X Ray ===
* [[Chest X-ray]] (infectious etiologies)

=== Other Imaging Findings ===
* [[Electroencephalogram]] ([[EEG]])

=== Other Diagnostic Studies ===
* [[Lumbar puncture]]

== Differential Diagnosis ==

===Common Causes<ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>===

* Alcohol withdrawal
* [[Bipolar Disorder]]
* Central nervous system (CNS) infections
* [[Delirium]]
* [[Dementia]]
* [[Encephalitis]]
* Hallucinogenic syndromes (drug-induced)
* Heavy metal ingestion
* Lewy Body Dementia
* Mass lesions
* Occipital lobe injury
* Postpartum major depression
* [[Post Traumatic Stress Disorder|Post-Traumatic Stress Disorder]]
* Psychotic disorder
* Schizoaffective disorder
* [[Schizophrenia]]
* Schizophreniform disorder
* [[Seizures]]
* [[Systemic Lupus Erythematosus]]

===Organ based===
{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Chemical / poisoning'''
|bgcolor="Beige"| [[Amanita muscaria]], [[Alcohol Withdrawal]], [[Carbon monoxide poisoning]], [[Alcoholism]], [[Mescaline]], [[Lysergic acid diethylamide]], [[Jenkem]], [[Nitrogen narcosis]], [[Laudanum]], [[Incapacitating agent]], [[Solanine]], [[Cocaine withdrawal ]], [[Bufotenin]], [[2C-T-2]], [[DESOXY]], [[3,4-Methylenedioxyamphetamine]], [[2C-E]], [[Dimethoxyamphetamine]], [[TOM (psychedelic)]], [[TOET (psychedelic)]], [[Substance D]], [[Ergot]], [[Henbane]], [[Phencyclidine]], [[Muscimol]], [[Datura tramonium]], [[Deadly nightshade]], [[Datura inoxia]], [[Datura wrightii]], [[Thujone]], [[5-Hydroxytryptophan]], [[2C-B]], [[2C-T-7]], [[Benzylpiperazine]], [[Candyflipping]], [[Mercury(II) chloride]], [[Ibotenic acid]], [[Khat]], [[PMA]], [[Amphetamine]], [[Psychedelic plants]], [[Psilocybin mushrooms]], [[Datura metel]], [[4-Acetoxy-DIPT]], [[Hallucinogen persisting perception disorder]], [[Formication]], [[Ergotism]], [[Ichthyoallyeinotoxism]], [[Abrin]], [[Delirium tremens]], [[Ascomycota]], [[Hawaiian baby woodrose]], [[Solanaceae]], [[Cocaine dependence]], [[5-F-AMT]], [[5-MeO-AMT]], [[Diisopropyltryptamine]], [[Dipropyltryptamine]], [[Marijuana intoxication]], [[Cannabis]], [[1,3-Butadiene ]], [[Acrylamide ]], [[Ammonium Sulfamate ]], [[Bromide]], [[Ether ]], [[Gasoline]], [[Glaze]], [[Sodium Monofluoroacetate ]], [[Solder]], [[Thallium]], [[Trichloroethane ]], [[Christmas Cherry poisoning]]

|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Procainamide ]], [[Alatrofloxacin Injection ]], [[Lomotil]], [[Fluphenazine ]], [[Acyclovir ]], [[Cefaclor]], [[Morphine Oral ]], [[Pentamidine Isethionate Injection ]], [[Alfentanil Hydrochloride Injection ]], [[Atropine]], [[Aspirin]], [[Zolpidem ]], [[Zaleplon ]], [[Voriconazole ]], [[Venlafaxine]], [[Trovafloxacin ]], [[Trihexyphenidyl ]], [[Trifluoperazine Oral ]], [[Tolterodine ]], [[Atomoxetine]], [[Tolcapone ]], [[Thiothixene Oral ]], [[Thioridazine ]], [[Benztropine Mesylate Oral ]], [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]], [[Bupropion]], [[Butorphanol Injection ]], [[Chlorpromazine ]], [[Clarithromycin]], [[Clomipramine ]], [[Dexmethylphenidate]], [[Dextroamphetamine]], [[Dextromethorphan]], [[Dimenhydrinate]], [[Efavirenz ]], [[Entacapone ]], [[Eszopiclone ]], [[Fluconazole ]], [[Flurazepam ]], [[Galantamine ]], [[Gatifloxacin ]], [[Gatifloxacin Injection ]], [[Haloperidol Oral ]], [[Ifosfamide ]], [[Ketorolac]], [[Levodopa]], [[Lithium ]], [[Loxapine Oral ]], [[Mefloquine ]], [[Memantine]], [[Methylphenidate Transdermal ]], [[Mirtazapine]], [[Modafinil ]], [[Nabilone ]], [[Nalbuphine injection ]], [[Naltrexone ]], [[Orphenadrine ]], [[Oxybutynin ]], [[Pemoline ]], [[Pergolide ]], [[Perphenazine oral ]], [[Phenelzine ]], [[Pramipexole ]], [[Prochlorperazine ]], [[Procyclidine ]], [[Promethazine ]], [[Ropinirole ]], [[Scopolamine patch ]], [[Selegiline ]], [[Sertraline]], [[Sodium oxybate ]], [[Solifenacin ]], [[Sufentanil citrate injection ]], [[Procyclidine hydrochloride]], [[3-Quinuclidinyl benzilate]], [[Ketamine]], [[Nalmefene]], [[Dezocine]], [[Dimethyltryptamine]], [[Scopolamine]], [[Methamphetamine]], [[Morphine]], [[Alprazolam]], [[Beta-blockers]], [[Buspirone]], [[Hydroxyzine]], [[Imipramine]], [[Lorazepam]], [[Phentermine]], [[Temazepam]], [[Tizanidine]], [[Triazolam]], [[Ethchlorvynol withdrawal ]], [[Serotonin syndrome]], [[Psychotomimetic]], [[Benzodiazepine withdrawal syndrome]], [[Ziconotide]], [[Diphenhydramine]], [[Dizocilpine]], [[NMDA receptor antagonist]], [[Pentazocine]], [[Opioid]], [[Ketazocine]], [[Valproate semisodium]], [[Ephedrine]], [[SSRI discontinuation syndrome]], [[Baclofen]], [[Flucytosine]], [[Oxamniquine]], [[Aciclovir]], [[Nitrazepam]], [[Loprazolam]], [[Lormetazepam]], [[Biperiden]], [[Clozapine]], [[Dantrolene]], [[Tricyclic antidepressant]], [[Zopiclone]], [[Propylhexedrine]], [[Dissociative drugs]], [[Toxidrome]], [[Tifluadom]], [[Phenazocine]], [[Etoxadrol]], [[Cabergoline]], [[Dexedrine overdose ]], [[Appian-Plutarch syndrome]], [[Isoniazid toxicity]], [[Ritalin overdose]], [[Steroids]], [[Barbiturate abuse]]

|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| [[Myxedematous psychosis]], [[Adrenal adenoma]], [[Adrenal Cancer ]], [[Adrenal gland hyperfunction]], [[Hyperadrenalism]], [[Cushing's Syndrome]], [[Adrenal incidentaloma]],

|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| [[Gluten-sensitive enteropathy associated conditions]]

|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| [[Creutzfeldt-Jakob Disease]], [[Rabies]], [[Acanthamoeba infection of the central nervous system]], [[Trypanosomiasis ]], [[Granulomatous amebic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Narcolepsy]], [[Encephalopathy]], [[Acute Disseminated Encephalomyelitis]], [[Migraine]], [[Dementia]], [[Delirium]], [[Complex partial seizure]], [[Arachnoid cyst]], [[Charles Bonnet syndrome]], [[Phantom eye syndrome]], [[Coats disease]], [[Entoptic phenomenon]], [[Closed-eye hallucination]], [[Cortical blindness]], [[High altitude cerebral edema]], [[Cerebral edema]], [[False memory]], [[Sleep deprivation]], [[Morvan's syndrome]], [[Fatal familial insomnia]], [[Endaural phenomena]], [[Parkinson plus syndrome]], [[Dementia with Lewy bodies]], [[Peduncular hallucinosis]], [[Temporal lobe epilepsy]], [[Aura (symptom)]], [[Parkinson's disease]], [[Traumatic brain injury]], [[Sensory deprivation]], [[Brain tumor]], [[Binswanger's disease]], [[Stroke]], [[Dana syndrome]], [[Lhermitte-McAlpine syndrome]], [[Autoimmune limbic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Nutritional / Metabolic'''
|bgcolor="Beige"| [[Porphyria]], [[Variegate porphyria]], [[Korsakoff's psychosis]], [[Nyssen-Van Bogaert syndrome ]]

|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Opthalmologic'''
|bgcolor="Beige"| [[Cataracts]], [[Glaucoma]], [[Retinal ischemia ]], [[Optic nerve lesion]]

|-
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
|bgcolor="Beige"| [[Pseudoephedrine]], [[Caffeine]], [[Mazindol]]

|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Schizophrenia]], [[Hypnagogia]], [[Kleine-Levin syndrome]], [[Clinical lycanthropy]], [[Paris syndrome]], [[Homosexual panic]], [[Ganser syndrome]], [[Psychosis]], [[Psychotic depression]], [[Clinical depression]], [[Stendhal syndrome]], [[Alice in Wonderland syndrome]], [[Delusional disorder]], [[Oneirophrenia]], [[Postnatal depression]], [[Avolition]], [[Disorganized schizophrenia]], [[Schizoaffective disorder]], [[Mania]], [[Schizotypal personality disorder]], [[Brief psychotic disorder]], [[Bipolar disease]], [[Grief ]], [[Bell mania]], [[Briquet syndrome]], [[Schizoid personality disorder]]

|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
|bgcolor="Beige"| [[Hypercalcemia]], [[Hypomagnesemia]], [[Kidney failure]]

|-
|-bgcolor="LightSteelBlue"
| '''Rheum / Immune / Allergy'''
|bgcolor="Beige"| Systemic Lupus Erythematosus

|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| [[Visual snow]], [[Apparitional experience]], [[Hallucinations in the sane]], [[Extreme fatigue]], [[Extreme physical stress]], [[Dehydration ]]

|-
|}

===In alphabetical order<ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>===
* [[1,3-Butadiene ]]
* [[2C-B]]
* [[2C-E]]
* [[2C-T-2]]
* [[2C-T-7]]
* [[3,4-Methylenedioxyamphetamine]]
* [[3-Quinuclidinyl benzilate]]
* [[4-Acetoxy-DIPT]]
* [[5-F-AMT]]
* [[5-Hydroxytryptophan]]
* [[5-MeO-AMT]]
* [[Abrin]]
* [[Acanthamoeba infection of the central nervous system]]
* [[Aciclovir]]
* [[Acrylamide ]]
* [[Acute Disseminated Encephalomyelitis]]
* [[Acyclovir ]]
* [[Adrenal adenoma]]
* [[Adrenal Cancer ]]
* [[Adrenal gland hyperfunction]]
* [[Adrenal incidentaloma]]
* [[Alatrofloxacin Injection ]]
* [[Alcohol Withdrawal]]
* [[Alcoholism]]
* [[Alfentanil Hydrochloride Injection ]]
* [[Alice in Wonderland syndrome]]
* [[Alprazolam]]
* [[Amanita muscaria]]
* [[Ammonium Sulfamate ]]
* [[Amphetamine]]
* [[Apparitional experience]]
* [[Appian-Plutarch syndrome]]
* [[Arachnoid cyst]]
* [[Ascomycota]]
* [[Aspirin]]
* [[Atomoxetine]]
* [[Atropine]]
* [[Aura (symptom)]]
* [[Autoimmune limbic encephalitis]]
* [[Avolition]]
* [[Baclofen]]
* [[Barbiturate abuse]]
* [[Bell mania]]
* [[Benzodiazepine withdrawal syndrome]]
* [[Benztropine Mesylate Oral ]]
* [[Benzylpiperazine]]
* [[Beta-blockers]]
* [[Binswanger's disease]]
* [[Biperiden]]
* [[Bipolar disease]]
* [[Brain tumor]]
* [[Brief psychotic disorder]]
* [[Briquet syndrome]]
* [[Bromide]]
* [[Bufotenin]]
* [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]]
* [[Bupropion]]
* [[Buspirone]]
* [[Butorphanol Injection ]]
* [[Cabergoline]]
* [[Caffeine]]
* [[Candyflipping]]
* [[Cannabis]]
* [[Carbon monoxide poisoning]]
* [[Cataracts]]
* [[Cefaclor]]
* [[Cerebral edema]]
* [[Charles Bonnet syndrome]]
* [[Chlorpromazine ]]
* [[Christmas Cherry poisoning]]
* [[Clarithromycin]]
* [[Clinical depression]]
* [[Clinical lycanthropy]]
* [[Clomipramine ]]
* [[Closed-eye hallucination]]
* [[Clozapine]]
* [[Coats disease]]
* [[Cocaine dependence]]
* [[Cocaine withdrawal ]]
* [[Complex partial seizure]]
* [[Cortical blindness]]
* [[Creutzfeldt-Jakob Disease]]
* [[Cushing's Syndrome]]
* [[Dana syndrome]]
* [[Dantrolene]]
* [[Datura inoxia]]
* [[Datura metel]]
* [[Datura stramonium]]
* [[Datura wrightii]]
* [[Deadly nightshade]]
* [[Dehydration ]]
* [[Delirium tremens]]
* [[Delirium]]
* [[Delusional disorder]]
* [[Dementia with Lewy bodies]]
* [[Dementia]]
* [[DESOXY]]
* [[Dexedrine overdose ]]
* [[Dexmethylphenidate]]
* [[Dexoxadrol]]
* [[Dextroamphetamine]]
* [[Dextromethorphan]]
* [[Dezocine]]
* [[Diisopropyltryptamine]]
* [[Dimenhydrinate]]
* [[Dimethoxyamphetamine]]
* [[Dimethyltryptamine]]
* [[Diphenhydramine]]
* [[Dipropyltryptamine]]
* [[Disorganized schizophrenia]]
* [[Dissociative drugs]]
* [[Dizocilpine]]
* [[Efavirenz ]]
* [[Encephalopathy]]
* [[Endaural phenomena]]
* [[Entacapone ]]
* [[Entoptic phenomenon]]
* [[Ephedrine]]
* [[Ergot]]
* [[Ergotism]]
* [[Eszopiclone ]]
* [[Ethchlorvynol withdrawal ]]
* [[Ether ]]
* [[Etoxadrol]]
* [[Extreme fatigue]]
* [[Extreme physical stress]]
* [[False memory]]
* [[Fatal familial insomnia]]
* [[Fluconazole ]]
* [[Flucytosine]]
* [[Fluphenazine ]]
* [[Flurazepam ]]
* [[Formication]]
* [[Galantamine ]]
* [[Ganser syndrome]]
* [[Gasoline]]
* [[Gatifloxacin ]]
* [[Gatifloxacin Injection ]]
* [[Glaucoma]]
* [[Glaze]]
* [[Gluten-sensitive enteropathy associated conditions]]
* [[Granulomatous amebic encephalitis]]
* [[Grief ]]
* [[Hallucinations in the sane]]
* [[Hallucinogen persisting perception disorder]]
* [[Haloperidol Oral ]]
* [[Hawaiian baby woodrose]]
* [[Henbane]]
* [[High altitude cerebral edema]]
* [[Homosexual panic]]
* [[Hydroxyzine]]
* [[Hyperadrenalism]]
* [[Hypercalcemia]]
* [[Hypnagogia]]
* [[Hypomagnesemia]]
* [[Ibotenic acid]]
* [[Ichthyoallyeinotoxism]]
* [[Ifosfamide ]]
* [[Imipramine]]
* [[Incapacitating agent]]
* [[Isoniazid toxicity]]
* [[Jenkem]]
* [[Ketamine]]
* [[Ketazocine]]
* [[Ketorolac]]
* [[Khat]]
* [[Kidney failure]]
* [[Kleine-Levin syndrome]]
* [[Korsakoff's psychosis]]
* [[Laudanum]]
* [[Levodopa]]
* [[Lhermitte-McAlpine syndrome]]
* [[Lithium ]]
* [[Lomotil]]
* [[Loprazolam]]
* [[Lorazepam]]
* [[Lormetazepam]]
* [[Loxapine Oral ]]
* [[Lysergic acid diethylamide]]
* [[Mania]]
* [[Marijuana intoxication]]
* [[Mazindol]]
* [[Mefloquine ]]
* [[Memantine]]
* [[Mercury(II) chloride]]
* [[Mescaline]]
* [[Methamphetamine]]
* [[Methylphenidate Transdermal ]]
* [[Migraine]]
* [[Mirtazapine]]
* [[Modafinil ]]
* [[Morphine Oral ]]
* [[Morphine]]
* [[Morvan's syndrome]]
* [[Muscimol]]
* [[Myxedematous psychosis]]
* [[Nabilone ]]
* [[Nalbuphine injection ]]
* [[Nalmefene]]
* [[Naltrexone ]]
* [[Narcolepsy]]
* [[Nitrazepam]]
* [[Nitrogen narcosis]]
* [[NMDA receptor antagonist]]
* [[Nyssen-Van Bogaert syndrome ]]
* [[Oneirophrenia]]
* [[Opioid]]
* [[Optic nerve lesion]]
* [[Orphenadrine ]]
* [[Oxamniquine]]
* [[Oxybutynin ]]
* [[Paris syndrome]]
* [[Parkinson plus syndrome]]
* [[Parkinson's disease]]
* [[Peduncular hallucinosis]]
* [[Pemoline ]]
* [[Pentamidine Isethionate Injection ]]
* [[Pentazocine]]
* [[Pergolide ]]
* [[Perphenazine oral ]]
* [[Phantom eye syndrome]]
* [[Phenazocine]]
* [[Phencyclidine]]
* [[Phenelzine ]]
* [[Phentermine]]
* [[PMA]]
* [[Porphyria]]
* [[Postnatal depression]]
* [[Pramipexole ]]
* [[Procainamide ]]
* [[Prochlorperazine ]]
* [[Procyclidine ]]
* [[Procyclidine hydrochloride]]
* [[Promethazine ]]
* [[Propylhexedrine]]
* [[Pseudoephedrine]]
* [[Psilocybin mushrooms]]
* [[Psychedelic plants]]
* [[Psychosis]]
* [[Psychotic depression]]
* [[Psychotomimetic]]
* [[Rabies]]
* [[Retinal ischemia ]]
* [[Ritalin overdose]]
* [[Ropinirole ]]
* [[Schizoaffective disorder]]
* [[Schizoid personality disorder]]
* [[Schizophrenia]]
* [[Schizotypal personality disorder]]
* [[Scopolamine patch ]]
* [[Scopolamine]]
* [[Selegiline ]]
* [[Sensory deprivation]]
* [[Serotonin syndrome]]
* [[Sertraline]]
* [[Sleep deprivation]]
* [[Sodium Monofluoroacetate ]]
* [[Sodium oxybate ]]
* [[Solanaceae]]
* [[Solanine]]
* [[Solder]]
* [[Solifenacin ]]
* [[SSRI discontinuation syndrome]]
* [[Stendhal syndrome]]
* [[Steroids]]
* [[Stroke]]
* [[Substance D]]
* [[Sufentanil citrate injection ]]
* [[Systemic Lupus Erythematosus]]
* [[Temazepam]]
* [[Temporal lobe epilepsy]]
* [[Thallium]]
* [[Thioridazine ]]
* [[Thiothixene Oral ]]
* [[Thujone]]
* [[Tifluadom]]
* [[Tizanidine]]
* [[TOET (psychedelic)]]
* [[Tolcapone ]]
* [[Tolterodine ]]
* [[TOM (psychedelic)]]
* [[Toxidrome]]
* [[Traumatic brain injury]]
* [[Triazolam]]
* [[Trichloroethane ]]
* [[Tricyclic antidepressant]]
* [[Trifluoperazine Oral ]]
* [[Trihexyphenidyl ]]
* [[Trovafloxacin ]]
* [[Trypanosomiasis ]]
* [[Valproate semisodium]]
* [[Variegate porphyria]]
* [[Venlafaxine]]
* [[Visual snow]]
* [[Voriconazole ]]
* [[Zaleplon ]]
* [[Ziconotide]]
* [[Zolpidem ]]
* [[Zopiclone]]

== Treatment ==
* Treat underlying etiologies

=== Acute Pharmacotherapies ===
* [[Antipsychotic drugs]]
* [[Benzodiazepine]]s

== See also ==
* [[Apparitional experience]]
* [[Closed-eye hallucination]]
* [[Delusion]]
* [[Dimethyltryptamine]]
* [[Dream]]
* [[Focal seizures]]
* [[Folie à deux]]
* Form constant
* [[Hallucinations in the sane]]
* [[Illusion]]
* Imaginary friend
* [[Phantom eye syndrome]]
* [[Psychedelics, dissociatives and deliriants|Hallucinogenic drug]]
* [[Psychosis]]
* [[Salvia divinorum]]
* Simulated reality

== References ==
{{reflist|2}}

{{SIB}}
{{WH}}
{{WS}}

[[Category:Signs and symptoms]]
[[Category:Psychiatry]]
[[Category:Mature chapter]]

[[cs:Halucinace]]
[[da:Hallucination]]
[[de:Halluzination]]
[[et:Hallutsinatsioon]]
[[es:Alucinación]]
[[fr:Hallucination]]
[[ga:Bréagchéadfa]]
[[it:Allucinazione]]
[[ku:Hallûsînasyon]]
[[he:הזיה]]
[[ka:ჰალუცინაცია]]
[[lb:Halluzinatioun]]
[[lt:Haliucinacija]]
[[hu:Hallucináció]]
[[mk:Халуцинација]]
[[nl:Hallucinatie]]
[[ja:幻覚]]
[[no:Hallusinasjon]]
[[pt:Alucinação]]
[[ru:Галлюцинация]]
[[simple:Hallucination]]
[[sk:Halucinácia]]
[[sl:Halucinacija]]
[[sr:Халуцинација]]
[[pl:Halucynacja]]
[[tr:Halüsinasyon]]
[[fi:Hallusinaatio]]
[[sv:Hallucination]]
[[ur:خطاۓ حس]]
[[zh:幻觉]]

Hallucination

2012-07-05T18:29:29Z

Aiham Jbeli: /* Differential Diagnosis */

'''For patient information click [[Hallucination (patient information)|here]]'''

{{Infobox_Disease |
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ICD10 = |
ICD9 = |
ICDO = |
OMIM = |
MedlinePlus = 003258 |
eMedicineSubj = |
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{{SI}}
{{CMG}}

==Overview==
A '''hallucination''' is a perception in the absence of a [[stimulus (physiology)|stimulus]] that the person may or may not believe is real (Hallucinations are psychotic symptoms that occur when patients perceive stimuli that do not exist). Hallucinations may occur in any sensory modality—[[visual system|visual]], [[auditory system|auditory]], [[olfaction|olfactory]], [[taste|gustatory]], [[tactition|tactile]], [[proprioception|proprioceptive]], [[equilibrioception|equilibrioceptive]], [[nociception|nociceptive]], [[thermoception|thermoceptive]]. Hallucinations are different from illusions. In an illusory experience, a genuine sensation is attributed to an incorrect cause, misinterpreting a coat hanging on a door to be an intruder or thinking there is water on a hot road, due to the heat rising from the road. A delusional perception is where a genuine perception (ie. correctly sensed and interpreted) is given some additional (and typically bizarre) significance. [[Hypnagogic hallucination]]s and [[hypnopompia|hypnopompic hallucination]]s are considered normal phenomena. Hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up. Hallucinations may also be associated with [[Psychoactive drug|drug]] use (particularly [[Psychedelics, dissociatives and deliriants|hallucinogenic drug]]s), [[sleep deprivation]], psychosis or [[neurological disorder|neurological illness]].

*Hallucinations may involve any of the five senses:
:* Auditory
:* Gustatory
:* Olfactory
:* Tactile
:* Visual
* The most common type of hallucinations are auditory
* Patients may either dismiss the hallucination as being false, or they may identify them to be true

==Prevalence==

Studies have now shown hallucinatory experiences take place across the world. Previous studies, one as early as 1894,<ref>Sidgwick, H., Johnson, A, Myers, FWH et al (1894) Report on the census of hallucinations. ''Proceedings of the Society for Psychical Research'', 34, 25-394. </ref> have reported that approximately 10% of the population experience hallucinations. A recent survey of over 9,000 people<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11166087&dopt=Abstract Ohayon MM. (2000)] Prevalence of hallucinations and their pathological associations in the general population. ''Psychiatry Research'', 97(2-3), 153-64. </ref> reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survey, [[olfactory]] (smell) and [[gustatory]] (taste) hallucinations seem the most common in the general population.

==Auditory hallucinations==

[[Sound|Auditory]] hallucinations, particularly of one or more talking voices, are particularly associated with [[psychosis|psychotic]] disorders such as [[schizophrenia]]. and the presence may have significance in diagnosing these conditions, People not suffering from diagnosable [[mental illness]] may sometimes hear voices as well.<ref>{{cite web | url = http://www.livescience.com/humanbiology/060915_hearing_voices.html | title = Hearing Voices: Some People Like It | last = Thompson | first = Andrea | publisher = LiveScience.com | date = September 15, 2006|accessdate = 2006-11-25 }}</ref> The [[Hearing Voices Movement]] is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucinations include musical hallucinations, where people will hear music playing in their mind, usually songs they are familiar with. This can be caused by [[lesions]] on the [[brain stem]], occurring most often from [[strokes]], but also [[tumors]], sencephalitis, or [[abscesses]].<ref>{{cite web | url = http://www.sciencedaily.com/releases/2000/08/000809065249.htm | title = Rare Hallucinations Make Music In The Mind | publisher = ScienceDaily.com | date = August 9, 2000 | accessdate = 2006-12-31 }}</ref> Recent reports have also mentioned that it is possible to get musical hallucinations from listening to music for long periods of time.

==Visual hallucinations==

===Hypnagogic hallucination===
These hallucinations occur just before falling asleep and affect a surprising number of people in the population. The hallucinations can last from seconds to minutes, all the while the subject usually remains aware of the true nature of the images. These are usually associated with [[narcolepsy]], but can also affect normal minds. Hypnagogic hallucinations are sometimes associated with brainstem abnormalities, but this is rare.<ref name=manford> [http://brain.oxfordjournals.org/cgi/content/abstract/121/10/1819 Manford and Andermann (1998)] Complex visual hallucinations. Clinical and Neurobiological insights''Brain'', 121(10), 1819-1840.</ref>

===Peduncular hallucinosis===
Peduncular means pertaining to the [[peduncle]], which is a neural tract running to and from the [[pons]] on the [[brain stem]]. These hallucinations occur most often in the evenings, but not during drowsiness as in the case of hypnagogic hallucination. The subject is usually fully conscious and can interact with the hallucinatory characters for extended periods of time. As in the case of [[hypnagogic hallucinations]], insight into the nature of the images remains intact. The false images can occur in any part of the visual field, and are rarely [[wikt:polymodal|polymodal]].<ref name=manford/>

===Delirium tremens===
{{main|Delerium tremens}}
One of the most enigmatic forms of visual hallucinations are the highly variable, possibly polymodal [[delirium tremens]]. Individuals suffering from delerium tremens may be agitated and confused, especially in the later stages of this disease. Insight is gradually reduced with the progression of this disorder. Sleep is disturbed and occurs for a shorter period of time, with [[REM overflow]].<ref name=manford/>

===Parkinson's disease and Lewy body dementia===
[[Parkinson's disease]] is linked with [[Dementia with Lewy bodies|Lewy body dementia]] for their similar hallucinatory symptoms. The symptoms strike during the evening in any part of the visual field and are rarely polymodal. The segue into hallucinations may start with illusions<ref>[http://www.nytimes.com/2006/02/14/health/14case.html?ex=1151121600&en=04560d31e7926bee&ei=5070 Mark Derr (2006)] Marilyn and Me, "The New York Times" Feb. 14th, 2006 </ref> where sensory perception is greatly distorted, but no novel sensory information is present. These typically last for several minutes, during which time the subject may be either conscious and normal or drowsy/inaccessible. Insight into these hallucinations is usually preserved and [[REM sleep]] is usually reduced. Parkinson's disease is usually associated with a degraded [[substantia nigra]] pars compacta, but recent evidence suggests that PD affects a number of sites in the brain. Some places of noted degradation include the median raphe nuclei, the noradrenergic parts of the locus coeruleus and the [[cholinergic]] neurons in the parabrachial and pedunculopontine nuclei of the [[tegmentum]].<ref name=manford/>

===Migraine coma===
This type of hallucination is usually experienced during the recovery from a comatose state. The migraine coma can last for up to two days and a state of depression is sometimes comorbid. The hallucinations occur during states of full consciousness and insight into the hallucinatory nature of the images is preserved. It has been noted that ataxic lesions accompany the migraine coma.<ref name=manford/>

===Charles Bonnet syndrome===
[[Charles Bonnet syndrome]] is the name given to visual hallucinations experienced by blind patients. The hallucinations can usually be dispersed by opening or closing the eyelids until the visual images disappear. The hallucinations usually occur during the morning or evening, but are not dependent on low light conditions. These prolonged hallucinations usually do not disturb the patients very much as they are aware that they are hallucinating.<ref name=manford/>

===Focal epilepsy===
The visual hallucinations from focal epilepsy are characterized by being brief, and stereotyped. They are usually localized to one part of the visual field and last only a few seconds. Other epileptic features may present themselves between visual episodes. Consciousness is usually impaired in some way, but nevertheless insight into the hallucination is preserved. Usually this type of focal epilepsy is caused by a lesion in the posterior temporoparietal.<ref name=manford/>

==Tactile hallucinations==

Can be associated with substance use, such as someone who feels bugs crawling on them after a prolonged period of [[cocaine]] use.

==Scientific explanations==
Various theories have been put forward to explain the occurrence of hallucinations. When [[psychodynamic]] ([[Freud]]ian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes, thoughts and wants. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the [[brain]]. With reference to mental illness, the function (or dysfunction) of the [[neurotransmitter]] [[dopamine]] is thought to be particularly important.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505794&dopt=Abstract Kapur S. (2003)] Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. ''American Journal of Psychiatry'', 160(1), 13-23. </ref>
[[Psychology|Psychological]] research has argued that hallucinations may result from biases in what are known as [[metacognition|metacognitive]] abilities.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2404293&dopt=Abstract Bentall RP. (1990)] The illusion of reality: a review and integration of psychological research on hallucinations. ''Psychological Bulletin'', 107(1), 82-95. </ref> These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, [[memory|memories]], [[belief]]s and [[thought]]s). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences. Projection of an internal state or a person's own reaction to another may arise in the form of hallucinations, especially auditory hallucinations. A few scientists have argued that such hallucinations may be the result of other conscious thoughts.

==Stages of a hallucination==
#Emergence of surprising or warded-off memory or [[fantasy (psychology)|fantasy]] images <ref name=horowitz>Horowitz, Mardi J., M.D. “Hallucinations: An Information Processing Approach." In Siegel, Ronald K., Ph. D. and L. J. West, eds. ''Hallucinations: Behavior, Experience and Theory'' (1975). New York: John Wiley.</ref>
#Frequent reality checks <ref name=horowitz />
#Last vestige of insight as hallucinations become “real” <ref name=horowitz />
#Fantasy and distortion elaborated upon and confused with actual perception <ref name=horowitz />
#Internal-external boundaries destroyed and possible pantheistic experience <ref name=horowitz />

==Diagnosis==

=== History and Symptoms ===
* Timing of hallucinations
* Suicidal/homicidal ideations
* Drug regimen
* Work with psychiatrist (if patient cannot communicate mental and physical history)

=== Laboratory Findings ===
* [[Complete blood count]] ([[CBC]])
* [[Glucose]]
* [[Calcium]]
* [[Albumin]]
* [[Alkaline phosphatase]]
* [[Blood urea nitrogen]] ([[BUN]])/[[creatinine]]
* [[Liver function tests]] ([[LFT]]s)
* [[Magnesium]]
* [[Phosphate]]
* [[Toxicology]] screen
* [[Urinalysis]]
* [[Pulse oximetry]]
* Drug levels
* [[Folate levels]]
* [[Vitamin B12]]
* [[Antinuclear antibody]] ([[ANA]])
* [[Heavy metal]] screen
* [[Ammonia]]

=== Electrolyte and Biomarker Studies ===

* Electrolytes

=== Chest X Ray ===
* [[Chest X-ray]] (infectious etiologies)

=== Other Imaging Findings ===
* [[Electroencephalogram]] ([[EEG]])

=== Other Diagnostic Studies ===
* [[Lumbar puncture]]

== Differential Diagnosis ==

In alphabetical order. <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>

* Alcohol withdrawal
* [[Bipolar Disorder]]
* Central nervous system (CNS) infections
* [[Delirium]]
* [[Dementia]]
* [[Encephalitis]]
* Hallucinogenic syndromes (drug-induced)
* Heavy metal ingestion
* Lewy Body Dementia
* Mass lesions
* Occipital lobe injury
* Postpartum major depression
* [[Post Traumatic Stress Disorder|Post-Traumatic Stress Disorder]]
* Psychotic disorder
* Schizoaffective disorder
* [[Schizophrenia]]
* Schizophreniform disorder
* [[Seizures]]
* [[Systemic Lupus Erythematosus]]

{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Chemical / poisoning'''
|bgcolor="Beige"| [[Amanita muscaria]], [[Alcohol Withdrawal]], [[Carbon monoxide poisoning]], [[Alcoholism]], [[Mescaline]], [[Lysergic acid diethylamide]], [[Jenkem]], [[Nitrogen narcosis]], [[Laudanum]], [[Incapacitating agent]], [[Solanine]], [[Cocaine withdrawal ]], [[Bufotenin]], [[2C-T-2]], [[DESOXY]], [[3,4-Methylenedioxyamphetamine]], [[2C-E]], [[Dimethoxyamphetamine]], [[TOM (psychedelic)]], [[TOET (psychedelic)]], [[Substance D]], [[Ergot]], [[Henbane]], [[Phencyclidine]], [[Muscimol]], [[Datura tramonium]], [[Deadly nightshade]], [[Datura inoxia]], [[Datura wrightii]], [[Thujone]], [[5-Hydroxytryptophan]], [[2C-B]], [[2C-T-7]], [[Benzylpiperazine]], [[Candyflipping]], [[Mercury(II) chloride]], [[Ibotenic acid]], [[Khat]], [[PMA]], [[Amphetamine]], [[Psychedelic plants]], [[Psilocybin mushrooms]], [[Datura metel]], [[4-Acetoxy-DIPT]], [[Hallucinogen persisting perception disorder]], [[Formication]], [[Ergotism]], [[Ichthyoallyeinotoxism]], [[Abrin]], [[Delirium tremens]], [[Ascomycota]], [[Hawaiian baby woodrose]], [[Solanaceae]], [[Cocaine dependence]], [[5-F-AMT]], [[5-MeO-AMT]], [[Diisopropyltryptamine]], [[Dipropyltryptamine]], [[Marijuana intoxication]], [[Cannabis]], [[1,3-Butadiene ]], [[Acrylamide ]], [[Ammonium Sulfamate ]], [[Bromide]], [[Ether ]], [[Gasoline]], [[Glaze]], [[Sodium Monofluoroacetate ]], [[Solder]], [[Thallium]], [[Trichloroethane ]], [[Christmas Cherry poisoning]]

|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Procainamide ]], [[Alatrofloxacin Injection ]], [[Lomotil]], [[Fluphenazine ]], [[Acyclovir ]], [[Cefaclor]], [[Morphine Oral ]], [[Pentamidine Isethionate Injection ]], [[Alfentanil Hydrochloride Injection ]], [[Atropine]], [[Aspirin]], [[Zolpidem ]], [[Zaleplon ]], [[Voriconazole ]], [[Venlafaxine]], [[Trovafloxacin ]], [[Trihexyphenidyl ]], [[Trifluoperazine Oral ]], [[Tolterodine ]], [[Atomoxetine]], [[Tolcapone ]], [[Thiothixene Oral ]], [[Thioridazine ]], [[Benztropine Mesylate Oral ]], [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]], [[Bupropion]], [[Butorphanol Injection ]], [[Chlorpromazine ]], [[Clarithromycin]], [[Clomipramine ]], [[Dexmethylphenidate]], [[Dextroamphetamine]], [[Dextromethorphan]], [[Dimenhydrinate]], [[Efavirenz ]], [[Entacapone ]], [[Eszopiclone ]], [[Fluconazole ]], [[Flurazepam ]], [[Galantamine ]], [[Gatifloxacin ]], [[Gatifloxacin Injection ]], [[Haloperidol Oral ]], [[Ifosfamide ]], [[Ketorolac]], [[Levodopa]], [[Lithium ]], [[Loxapine Oral ]], [[Mefloquine ]], [[Memantine]], [[Methylphenidate Transdermal ]], [[Mirtazapine]], [[Modafinil ]], [[Nabilone ]], [[Nalbuphine injection ]], [[Naltrexone ]], [[Orphenadrine ]], [[Oxybutynin ]], [[Pemoline ]], [[Pergolide ]], [[Perphenazine oral ]], [[Phenelzine ]], [[Pramipexole ]], [[Prochlorperazine ]], [[Procyclidine ]], [[Promethazine ]], [[Ropinirole ]], [[Scopolamine patch ]], [[Selegiline ]], [[Sertraline]], [[Sodium oxybate ]], [[Solifenacin ]], [[Sufentanil citrate injection ]], [[Procyclidine hydrochloride]], [[3-Quinuclidinyl benzilate]], [[Ketamine]], [[Nalmefene]], [[Dezocine]], [[Dimethyltryptamine]], [[Scopolamine]], [[Methamphetamine]], [[Morphine]], [[Alprazolam]], [[Beta-blockers]], [[Buspirone]], [[Hydroxyzine]], [[Imipramine]], [[Lorazepam]], [[Phentermine]], [[Temazepam]], [[Tizanidine]], [[Triazolam]], [[Ethchlorvynol withdrawal ]], [[Serotonin syndrome]], [[Psychotomimetic]], [[Benzodiazepine withdrawal syndrome]], [[Ziconotide]], [[Diphenhydramine]], [[Dizocilpine]], [[NMDA receptor antagonist]], [[Pentazocine]], [[Opioid]], [[Ketazocine]], [[Valproate semisodium]], [[Ephedrine]], [[SSRI discontinuation syndrome]], [[Baclofen]], [[Flucytosine]], [[Oxamniquine]], [[Aciclovir]], [[Nitrazepam]], [[Loprazolam]], [[Lormetazepam]], [[Biperiden]], [[Clozapine]], [[Dantrolene]], [[Tricyclic antidepressant]], [[Zopiclone]], [[Propylhexedrine]], [[Dissociative drugs]], [[Toxidrome]], [[Tifluadom]], [[Phenazocine]], [[Etoxadrol]], [[Cabergoline]], [[Dexedrine overdose ]], [[Appian-Plutarch syndrome]], [[Isoniazid toxicity]], [[Ritalin overdose]], [[Steroids]], [[Barbiturate abuse]]

|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| [[Myxedematous psychosis]], [[Adrenal adenoma]], [[Adrenal Cancer ]], [[Adrenal gland hyperfunction]], [[Hyperadrenalism]], [[Cushing's Syndrome]], [[Adrenal incidentaloma]],

|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| [[Gluten-sensitive enteropathy associated conditions]]

|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| [[Creutzfeldt-Jakob Disease]], [[Rabies]], [[Acanthamoeba infection of the central nervous system]], [[Trypanosomiasis ]], [[Granulomatous amebic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Narcolepsy]], [[Encephalopathy]], [[Acute Disseminated Encephalomyelitis]], [[Migraine]], [[Dementia]], [[Delirium]], [[Complex partial seizure]], [[Arachnoid cyst]], [[Charles Bonnet syndrome]], [[Phantom eye syndrome]], [[Coats disease]], [[Entoptic phenomenon]], [[Closed-eye hallucination]], [[Cortical blindness]], [[High altitude cerebral edema]], [[Cerebral edema]], [[False memory]], [[Sleep deprivation]], [[Morvan's syndrome]], [[Fatal familial insomnia]], [[Endaural phenomena]], [[Parkinson plus syndrome]], [[Dementia with Lewy bodies]], [[Peduncular hallucinosis]], [[Temporal lobe epilepsy]], [[Aura (symptom)]], [[Parkinson's disease]], [[Traumatic brain injury]], [[Sensory deprivation]], [[Brain tumor]], [[Binswanger's disease]], [[Stroke]], [[Dana syndrome]], [[Lhermitte-McAlpine syndrome]], [[Autoimmune limbic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Nutritional / Metabolic'''
|bgcolor="Beige"| [[Porphyria]], [[Variegate porphyria]], [[Korsakoff's psychosis]], [[Nyssen-Van Bogaert syndrome ]]

|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Opthalmologic'''
|bgcolor="Beige"| [[Cataracts]], [[Glaucoma]], [[Retinal ischemia ]], [[Optic nerve lesion]]

|-
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
|bgcolor="Beige"| [[Pseudoephedrine]], [[Caffeine]], [[Mazindol]]

|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Schizophrenia]], [[Hypnagogia]], [[Kleine-Levin syndrome]], [[Clinical lycanthropy]], [[Paris syndrome]], [[Homosexual panic]], [[Ganser syndrome]], [[Psychosis]], [[Psychotic depression]], [[Clinical depression]], [[Stendhal syndrome]], [[Alice in Wonderland syndrome]], [[Delusional disorder]], [[Oneirophrenia]], [[Postnatal depression]], [[Avolition]], [[Disorganized schizophrenia]], [[Schizoaffective disorder]], [[Mania]], [[Schizotypal personality disorder]], [[Brief psychotic disorder]], [[Bipolar disease]], [[Grief ]], [[Bell mania]], [[Briquet syndrome]], [[Schizoid personality disorder]]

|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
|bgcolor="Beige"| [[Hypercalcemia]], [[Hypomagnesemia]], [[Kidney failure]]

|-
|-bgcolor="LightSteelBlue"
| '''Rheum / Immune / Allergy'''
|bgcolor="Beige"| Systemic Lupus Erythematosus

|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| [[Visual snow]], [[Apparitional experience]], [[Hallucinations in the sane]], [[Extreme fatigue]], [[Extreme physical stress]], [[Dehydration ]]

|-
|}

== Treatment ==
* Treat underlying etiologies

=== Acute Pharmacotherapies ===
* [[Antipsychotic drugs]]
* [[Benzodiazepine]]s

== See also ==
* [[Apparitional experience]]
* [[Closed-eye hallucination]]
* [[Delusion]]
* [[Dimethyltryptamine]]
* [[Dream]]
* [[Focal seizures]]
* [[Folie à deux]]
* Form constant
* [[Hallucinations in the sane]]
* [[Illusion]]
* Imaginary friend
* [[Phantom eye syndrome]]
* [[Psychedelics, dissociatives and deliriants|Hallucinogenic drug]]
* [[Psychosis]]
* [[Salvia divinorum]]
* Simulated reality

== References ==
{{reflist|2}}

{{SIB}}
{{WH}}
{{WS}}

[[Category:Signs and symptoms]]
[[Category:Psychiatry]]
[[Category:Mature chapter]]

[[cs:Halucinace]]
[[da:Hallucination]]
[[de:Halluzination]]
[[et:Hallutsinatsioon]]
[[es:Alucinación]]
[[fr:Hallucination]]
[[ga:Bréagchéadfa]]
[[it:Allucinazione]]
[[ku:Hallûsînasyon]]
[[he:הזיה]]
[[ka:ჰალუცინაცია]]
[[lb:Halluzinatioun]]
[[lt:Haliucinacija]]
[[hu:Hallucináció]]
[[mk:Халуцинација]]
[[nl:Hallucinatie]]
[[ja:幻覚]]
[[no:Hallusinasjon]]
[[pt:Alucinação]]
[[ru:Галлюцинация]]
[[simple:Hallucination]]
[[sk:Halucinácia]]
[[sl:Halucinacija]]
[[sr:Халуцинација]]
[[pl:Halucynacja]]
[[tr:Halüsinasyon]]
[[fi:Hallusinaatio]]
[[sv:Hallucination]]
[[ur:خطاۓ حس]]
[[zh:幻觉]]

Hallucination

2012-07-05T18:20:25Z

Aiham Jbeli: /* Differential Diagnosis */

'''For patient information click [[Hallucination (patient information)|here]]'''

{{Infobox_Disease |
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ICDO = |
OMIM = |
MedlinePlus = 003258 |
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{{SI}}
{{CMG}}

==Overview==
A '''hallucination''' is a perception in the absence of a [[stimulus (physiology)|stimulus]] that the person may or may not believe is real (Hallucinations are psychotic symptoms that occur when patients perceive stimuli that do not exist). Hallucinations may occur in any sensory modality—[[visual system|visual]], [[auditory system|auditory]], [[olfaction|olfactory]], [[taste|gustatory]], [[tactition|tactile]], [[proprioception|proprioceptive]], [[equilibrioception|equilibrioceptive]], [[nociception|nociceptive]], [[thermoception|thermoceptive]]. Hallucinations are different from illusions. In an illusory experience, a genuine sensation is attributed to an incorrect cause, misinterpreting a coat hanging on a door to be an intruder or thinking there is water on a hot road, due to the heat rising from the road. A delusional perception is where a genuine perception (ie. correctly sensed and interpreted) is given some additional (and typically bizarre) significance. [[Hypnagogic hallucination]]s and [[hypnopompia|hypnopompic hallucination]]s are considered normal phenomena. Hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up. Hallucinations may also be associated with [[Psychoactive drug|drug]] use (particularly [[Psychedelics, dissociatives and deliriants|hallucinogenic drug]]s), [[sleep deprivation]], psychosis or [[neurological disorder|neurological illness]].

*Hallucinations may involve any of the five senses:
:* Auditory
:* Gustatory
:* Olfactory
:* Tactile
:* Visual
* The most common type of hallucinations are auditory
* Patients may either dismiss the hallucination as being false, or they may identify them to be true

==Prevalence==

Studies have now shown hallucinatory experiences take place across the world. Previous studies, one as early as 1894,<ref>Sidgwick, H., Johnson, A, Myers, FWH et al (1894) Report on the census of hallucinations. ''Proceedings of the Society for Psychical Research'', 34, 25-394. </ref> have reported that approximately 10% of the population experience hallucinations. A recent survey of over 9,000 people<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11166087&dopt=Abstract Ohayon MM. (2000)] Prevalence of hallucinations and their pathological associations in the general population. ''Psychiatry Research'', 97(2-3), 153-64. </ref> reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survey, [[olfactory]] (smell) and [[gustatory]] (taste) hallucinations seem the most common in the general population.

==Auditory hallucinations==

[[Sound|Auditory]] hallucinations, particularly of one or more talking voices, are particularly associated with [[psychosis|psychotic]] disorders such as [[schizophrenia]]. and the presence may have significance in diagnosing these conditions, People not suffering from diagnosable [[mental illness]] may sometimes hear voices as well.<ref>{{cite web | url = http://www.livescience.com/humanbiology/060915_hearing_voices.html | title = Hearing Voices: Some People Like It | last = Thompson | first = Andrea | publisher = LiveScience.com | date = September 15, 2006|accessdate = 2006-11-25 }}</ref> The [[Hearing Voices Movement]] is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucinations include musical hallucinations, where people will hear music playing in their mind, usually songs they are familiar with. This can be caused by [[lesions]] on the [[brain stem]], occurring most often from [[strokes]], but also [[tumors]], sencephalitis, or [[abscesses]].<ref>{{cite web | url = http://www.sciencedaily.com/releases/2000/08/000809065249.htm | title = Rare Hallucinations Make Music In The Mind | publisher = ScienceDaily.com | date = August 9, 2000 | accessdate = 2006-12-31 }}</ref> Recent reports have also mentioned that it is possible to get musical hallucinations from listening to music for long periods of time.

==Visual hallucinations==

===Hypnagogic hallucination===
These hallucinations occur just before falling asleep and affect a surprising number of people in the population. The hallucinations can last from seconds to minutes, all the while the subject usually remains aware of the true nature of the images. These are usually associated with [[narcolepsy]], but can also affect normal minds. Hypnagogic hallucinations are sometimes associated with brainstem abnormalities, but this is rare.<ref name=manford> [http://brain.oxfordjournals.org/cgi/content/abstract/121/10/1819 Manford and Andermann (1998)] Complex visual hallucinations. Clinical and Neurobiological insights''Brain'', 121(10), 1819-1840.</ref>

===Peduncular hallucinosis===
Peduncular means pertaining to the [[peduncle]], which is a neural tract running to and from the [[pons]] on the [[brain stem]]. These hallucinations occur most often in the evenings, but not during drowsiness as in the case of hypnagogic hallucination. The subject is usually fully conscious and can interact with the hallucinatory characters for extended periods of time. As in the case of [[hypnagogic hallucinations]], insight into the nature of the images remains intact. The false images can occur in any part of the visual field, and are rarely [[wikt:polymodal|polymodal]].<ref name=manford/>

===Delirium tremens===
{{main|Delerium tremens}}
One of the most enigmatic forms of visual hallucinations are the highly variable, possibly polymodal [[delirium tremens]]. Individuals suffering from delerium tremens may be agitated and confused, especially in the later stages of this disease. Insight is gradually reduced with the progression of this disorder. Sleep is disturbed and occurs for a shorter period of time, with [[REM overflow]].<ref name=manford/>

===Parkinson's disease and Lewy body dementia===
[[Parkinson's disease]] is linked with [[Dementia with Lewy bodies|Lewy body dementia]] for their similar hallucinatory symptoms. The symptoms strike during the evening in any part of the visual field and are rarely polymodal. The segue into hallucinations may start with illusions<ref>[http://www.nytimes.com/2006/02/14/health/14case.html?ex=1151121600&en=04560d31e7926bee&ei=5070 Mark Derr (2006)] Marilyn and Me, "The New York Times" Feb. 14th, 2006 </ref> where sensory perception is greatly distorted, but no novel sensory information is present. These typically last for several minutes, during which time the subject may be either conscious and normal or drowsy/inaccessible. Insight into these hallucinations is usually preserved and [[REM sleep]] is usually reduced. Parkinson's disease is usually associated with a degraded [[substantia nigra]] pars compacta, but recent evidence suggests that PD affects a number of sites in the brain. Some places of noted degradation include the median raphe nuclei, the noradrenergic parts of the locus coeruleus and the [[cholinergic]] neurons in the parabrachial and pedunculopontine nuclei of the [[tegmentum]].<ref name=manford/>

===Migraine coma===
This type of hallucination is usually experienced during the recovery from a comatose state. The migraine coma can last for up to two days and a state of depression is sometimes comorbid. The hallucinations occur during states of full consciousness and insight into the hallucinatory nature of the images is preserved. It has been noted that ataxic lesions accompany the migraine coma.<ref name=manford/>

===Charles Bonnet syndrome===
[[Charles Bonnet syndrome]] is the name given to visual hallucinations experienced by blind patients. The hallucinations can usually be dispersed by opening or closing the eyelids until the visual images disappear. The hallucinations usually occur during the morning or evening, but are not dependent on low light conditions. These prolonged hallucinations usually do not disturb the patients very much as they are aware that they are hallucinating.<ref name=manford/>

===Focal epilepsy===
The visual hallucinations from focal epilepsy are characterized by being brief, and stereotyped. They are usually localized to one part of the visual field and last only a few seconds. Other epileptic features may present themselves between visual episodes. Consciousness is usually impaired in some way, but nevertheless insight into the hallucination is preserved. Usually this type of focal epilepsy is caused by a lesion in the posterior temporoparietal.<ref name=manford/>

==Tactile hallucinations==

Can be associated with substance use, such as someone who feels bugs crawling on them after a prolonged period of [[cocaine]] use.

==Scientific explanations==
Various theories have been put forward to explain the occurrence of hallucinations. When [[psychodynamic]] ([[Freud]]ian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes, thoughts and wants. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the [[brain]]. With reference to mental illness, the function (or dysfunction) of the [[neurotransmitter]] [[dopamine]] is thought to be particularly important.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505794&dopt=Abstract Kapur S. (2003)] Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. ''American Journal of Psychiatry'', 160(1), 13-23. </ref>
[[Psychology|Psychological]] research has argued that hallucinations may result from biases in what are known as [[metacognition|metacognitive]] abilities.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2404293&dopt=Abstract Bentall RP. (1990)] The illusion of reality: a review and integration of psychological research on hallucinations. ''Psychological Bulletin'', 107(1), 82-95. </ref> These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, [[memory|memories]], [[belief]]s and [[thought]]s). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences. Projection of an internal state or a person's own reaction to another may arise in the form of hallucinations, especially auditory hallucinations. A few scientists have argued that such hallucinations may be the result of other conscious thoughts.

==Stages of a hallucination==
#Emergence of surprising or warded-off memory or [[fantasy (psychology)|fantasy]] images <ref name=horowitz>Horowitz, Mardi J., M.D. “Hallucinations: An Information Processing Approach." In Siegel, Ronald K., Ph. D. and L. J. West, eds. ''Hallucinations: Behavior, Experience and Theory'' (1975). New York: John Wiley.</ref>
#Frequent reality checks <ref name=horowitz />
#Last vestige of insight as hallucinations become “real” <ref name=horowitz />
#Fantasy and distortion elaborated upon and confused with actual perception <ref name=horowitz />
#Internal-external boundaries destroyed and possible pantheistic experience <ref name=horowitz />

==Diagnosis==

=== History and Symptoms ===
* Timing of hallucinations
* Suicidal/homicidal ideations
* Drug regimen
* Work with psychiatrist (if patient cannot communicate mental and physical history)

=== Laboratory Findings ===
* [[Complete blood count]] ([[CBC]])
* [[Glucose]]
* [[Calcium]]
* [[Albumin]]
* [[Alkaline phosphatase]]
* [[Blood urea nitrogen]] ([[BUN]])/[[creatinine]]
* [[Liver function tests]] ([[LFT]]s)
* [[Magnesium]]
* [[Phosphate]]
* [[Toxicology]] screen
* [[Urinalysis]]
* [[Pulse oximetry]]
* Drug levels
* [[Folate levels]]
* [[Vitamin B12]]
* [[Antinuclear antibody]] ([[ANA]])
* [[Heavy metal]] screen
* [[Ammonia]]

=== Electrolyte and Biomarker Studies ===

* Electrolytes

=== Chest X Ray ===
* [[Chest X-ray]] (infectious etiologies)

=== Other Imaging Findings ===
* [[Electroencephalogram]] ([[EEG]])

=== Other Diagnostic Studies ===
* [[Lumbar puncture]]

== Differential Diagnosis ==

In alphabetical order. <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>

* Alcohol withdrawal
* [[Bipolar Disorder]]
* Central nervous system (CNS) infections
* [[Delirium]]
* [[Dementia]]
* [[Encephalitis]]
* Hallucinogenic syndromes (drug-induced)
* Heavy metal ingestion
* Lewy Body Dementia
* Mass lesions
* Occipital lobe injury
* Postpartum major depression
* [[Post Traumatic Stress Disorder|Post-Traumatic Stress Disorder]]
* Psychotic disorder
* Schizoaffective disorder
* [[Schizophrenia]]
* Schizophreniform disorder
* [[Seizures]]
* [[Systemic Lupus Erythematosus]]

{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Chemical / poisoning'''
|bgcolor="Beige"| [[Amanita muscaria]], [[Alcohol Withdrawal]], [[Carbon monoxide poisoning]], [[Alcoholism]], [[Mescaline]], [[Lysergic acid diethylamide]], [[Jenkem]], [[Nitrogen narcosis]], [[Laudanum]], [[Incapacitating agent]], [[Solanine]], [[Cocaine withdrawal ]], [[Bufotenin]], [[2C-T-2]], [[DESOXY]], [[3,4-Methylenedioxyamphetamine]], [[2C-E]], [[Dimethoxyamphetamine]], [[TOM (psychedelic)]], [[TOET (psychedelic)]], [[Substance D]], [[Ergot]], [[Henbane]], [[Phencyclidine]], [[Muscimol]], [[Datura tramonium]], [[Deadly nightshade]], [[Datura inoxia]], [[Datura wrightii]], [[Thujone]], [[5-Hydroxytryptophan]], [[2C-B]], [[2C-T-7]], [[Benzylpiperazine]], [[Candyflipping]], [[Mercury(II) chloride]], [[Ibotenic acid]], [[Khat]], [[PMA]], [[Amphetamine]], [[Psychedelic plants]], [[Psilocybin mushrooms]], [[Datura metel]], [[4-Acetoxy-DIPT]], [[Hallucinogen persisting perception disorder]], [[Formication]], [[Ergotism]], [[Ichthyoallyeinotoxism]], [[Abrin]], [[Delirium tremens]], [[Ascomycota]], [[Hawaiian baby woodrose]], [[Solanaceae]], [[Cocaine dependence]], [[5-F-AMT]], [[5-MeO-AMT]], [[Diisopropyltryptamine]], [[Dipropyltryptamine]], [[Marijuana intoxication]], [[Cannabis]], [[1,3-Butadiene ]], [[Acrylamide ]], [[Ammonium Sulfamate ]], [[Bromide]], [[Ether ]], [[Gasoline]], [[Glaze]], [[Sodium Monofluoroacetate ]], [[Solder]], [[Thallium]], [[Trichloroethane ]], [[Christmas Cherry poisoning]]

|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Procainamide ]], [[Alatrofloxacin Injection ]], [[Lomotil]], [[Fluphenazine ]], [[Acyclovir ]], [[Cefaclor]], [[Morphine Oral ]], [[Pentamidine Isethionate Injection ]], [[Alfentanil Hydrochloride Injection ]], [[Atropine]], [[Aspirin]], [[Zolpidem ]], [[Zaleplon ]], [[Voriconazole ]], [[Venlafaxine]], [[Trovafloxacin ]], [[Trihexyphenidyl ]], [[Trifluoperazine Oral ]], [[Tolterodine ]], [[Atomoxetine]], [[Tolcapone ]], [[Thiothixene Oral ]], [[Thioridazine ]], [[Benztropine Mesylate Oral ]], [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]], [[Bupropion]], [[Butorphanol Injection ]], [[Chlorpromazine ]], [[Clarithromycin]], [[Clomipramine ]], [[Dexmethylphenidate]], [[Dextroamphetamine]], [[Dextromethorphan]], [[Dimenhydrinate]], [[Efavirenz ]], [[Entacapone ]], [[Eszopiclone ]], [[Fluconazole ]], [[Flurazepam ]], [[Galantamine ]], [[Gatifloxacin ]], [[Gatifloxacin Injection ]], [[Haloperidol Oral ]], [[Ifosfamide ]], [[Ketorolac]], [[Levodopa]], [[Lithium ]], [[Loxapine Oral ]], [[Mefloquine ]], [[Memantine]], [[Methylphenidate Transdermal ]], [[Mirtazapine]], [[Modafinil ]], [[Nabilone ]], [[Nalbuphine injection ]], [[Naltrexone ]], [[Orphenadrine ]], [[Oxybutynin ]], [[Pemoline ]], [[Pergolide ]], [[Perphenazine oral ]], [[Phenelzine ]], [[Pramipexole ]], [[Prochlorperazine ]], [[Procyclidine ]], [[Promethazine ]], [[Ropinirole ]], [[Scopolamine patch ]], [[Selegiline ]], [[Sertraline]], [[Sodium oxybate ]], [[Solifenacin ]], [[Sufentanil citrate injection ]], [[Procyclidine hydrochloride]], [[3-Quinuclidinyl benzilate]], [[Ketamine]], [[Nalmefene]], [[Dezocine]], [[Dimethyltryptamine]], [[Scopolamine]], [[Methamphetamine]], [[Morphine]], [[Alprazolam]], [[Beta-blockers]], [[Buspirone]], [[Hydroxyzine]], [[Imipramine]], [[Lorazepam]], [[Phentermine]], [[Temazepam]], [[Tizanidine]], [[Triazolam]], [[Ethchlorvynol withdrawal ]], [[Serotonin syndrome]], [[Psychotomimetic]], [[Benzodiazepine withdrawal syndrome]], [[Ziconotide]], [[Diphenhydramine]], [[Dizocilpine]], [[NMDA receptor antagonist]], [[Pentazocine]], [[Opioid]], [[Ketazocine]], [[Valproate semisodium]], [[Ephedrine]], [[SSRI discontinuation syndrome]], [[Baclofen]], [[Flucytosine]], [[Oxamniquine]], [[Aciclovir]], [[Nitrazepam]], [[Loprazolam]], [[Lormetazepam]], [[Biperiden]], [[Clozapine]], [[Dantrolene]], [[Tricyclic antidepressant]], [[Zopiclone]], [[Propylhexedrine]], [[Dissociative drugs]], [[Toxidrome]], [[Tifluadom]], [[Phenazocine]], [[Etoxadrol]], [[Cabergoline]], [[Dexedrine overdose ]], [[Appian-Plutarch syndrome]], [[Isoniazid toxicity]], [[Ritalin overdose]], [[Barbiturate abuse]]

|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| [[Myxedematous psychosis]], [[Adrenal adenoma]], [[Adrenal Cancer ]], [[Adrenal gland hyperfunction]], [[Hyperadrenalism]], [[Adrenal incidentaloma]]

|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| [[Gluten-sensitive enteropathy associated conditions]]

|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| [[Creutzfeldt-Jakob Disease]], [[Rabies]], [[Acanthamoeba infection of the central nervous system]], [[Trypanosomiasis ]], [[Granulomatous amebic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Narcolepsy]], [[Encephalopathy]], [[Acute Disseminated Encephalomyelitis]], [[Migraine]], [[Dementia]], [[Delirium]], [[Complex partial seizure]], [[Arachnoid cyst]], [[Charles Bonnet syndrome]], [[Phantom eye syndrome]], [[Coats disease]], [[Entoptic phenomenon]], [[Closed-eye hallucination]], [[Cortical blindness]], [[High altitude cerebral edema]], [[Cerebral edema]], [[False memory]], [[Sleep deprivation]], [[Morvan's syndrome]], [[Fatal familial insomnia]], [[Endaural phenomena]], [[Parkinson plus syndrome]], [[Dementia with Lewy bodies]], [[Peduncular hallucinosis]], [[Temporal lobe epilepsy]], [[Aura (symptom)]], [[Parkinson's disease]], [[Traumatic brain injury]], [[Sensory deprivation]], [[Brain tumor]], [[Binswanger's disease]], [[Stroke]], [[Dana syndrome]], [[Lhermitte-McAlpine syndrome]], [[Autoimmune limbic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Nutritional / Metabolic'''
|bgcolor="Beige"| [[Porphyria]], [[Variegate porphyria]], [[Korsakoff's psychosis]], [[Nyssen-Van Bogaert syndrome ]]

|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Opthalmologic'''
|bgcolor="Beige"| [[Cataracts]], [[Glaucoma]], [[Retinal ischemia ]], [[Optic nerve lesion]]

|-
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
|bgcolor="Beige"| [[Pseudoephedrine]], [[Caffeine]], [[Mazindol]]

|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Schizophrenia]], [[Hypnagogia]], [[Kleine-Levin syndrome]], [[Clinical lycanthropy]], [[Paris syndrome]], [[Homosexual panic]], [[Ganser syndrome]], [[Psychosis]], [[Psychotic depression]], [[Clinical depression]], [[Stendhal syndrome]], [[Alice in Wonderland syndrome]], [[Delusional disorder]], [[Oneirophrenia]], [[Postnatal depression]], [[Avolition]], [[Disorganized schizophrenia]], [[Schizoaffective disorder]], [[Mania]], [[Schizotypal personality disorder]], [[Brief psychotic disorder]], [[Bipolar disease]], [[Grief ]], [[Bell mania]], [[Briquet syndrome]], [[Schizoid personality disorder]]

|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
|bgcolor="Beige"| [[Hypercalcemia]], [[Hypomagnesemia]], [[Kidney failure]]

|-
|-bgcolor="LightSteelBlue"
| '''Rheum / Immune / Allergy'''
|bgcolor="Beige"| Systemic Lupus Erythematosus

|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| [[Visual snow]], [[Apparitional experience]], [[Hallucinations in the sane]], [[Extreme fatigue]], [[Extreme physical stress]], [[Dehydration ]]

|-
|}

== Treatment ==
* Treat underlying etiologies

=== Acute Pharmacotherapies ===
* [[Antipsychotic drugs]]
* [[Benzodiazepine]]s

== See also ==
* [[Apparitional experience]]
* [[Closed-eye hallucination]]
* [[Delusion]]
* [[Dimethyltryptamine]]
* [[Dream]]
* [[Focal seizures]]
* [[Folie à deux]]
* Form constant
* [[Hallucinations in the sane]]
* [[Illusion]]
* Imaginary friend
* [[Phantom eye syndrome]]
* [[Psychedelics, dissociatives and deliriants|Hallucinogenic drug]]
* [[Psychosis]]
* [[Salvia divinorum]]
* Simulated reality

== References ==
{{reflist|2}}

{{SIB}}
{{WH}}
{{WS}}

[[Category:Signs and symptoms]]
[[Category:Psychiatry]]
[[Category:Mature chapter]]

[[cs:Halucinace]]
[[da:Hallucination]]
[[de:Halluzination]]
[[et:Hallutsinatsioon]]
[[es:Alucinación]]
[[fr:Hallucination]]
[[ga:Bréagchéadfa]]
[[it:Allucinazione]]
[[ku:Hallûsînasyon]]
[[he:הזיה]]
[[ka:ჰალუცინაცია]]
[[lb:Halluzinatioun]]
[[lt:Haliucinacija]]
[[hu:Hallucináció]]
[[mk:Халуцинација]]
[[nl:Hallucinatie]]
[[ja:幻覚]]
[[no:Hallusinasjon]]
[[pt:Alucinação]]
[[ru:Галлюцинация]]
[[simple:Hallucination]]
[[sk:Halucinácia]]
[[sl:Halucinacija]]
[[sr:Халуцинација]]
[[pl:Halucynacja]]
[[tr:Halüsinasyon]]
[[fi:Hallusinaatio]]
[[sv:Hallucination]]
[[ur:خطاۓ حس]]
[[zh:幻觉]]

Hallucination

2012-07-05T18:14:44Z

Aiham Jbeli: /* Differential Diagnosis */

'''For patient information click [[Hallucination (patient information)|here]]'''

{{Infobox_Disease |
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MedlinePlus = 003258 |
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{{SI}}
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==Overview==
A '''hallucination''' is a perception in the absence of a [[stimulus (physiology)|stimulus]] that the person may or may not believe is real (Hallucinations are psychotic symptoms that occur when patients perceive stimuli that do not exist). Hallucinations may occur in any sensory modality—[[visual system|visual]], [[auditory system|auditory]], [[olfaction|olfactory]], [[taste|gustatory]], [[tactition|tactile]], [[proprioception|proprioceptive]], [[equilibrioception|equilibrioceptive]], [[nociception|nociceptive]], [[thermoception|thermoceptive]]. Hallucinations are different from illusions. In an illusory experience, a genuine sensation is attributed to an incorrect cause, misinterpreting a coat hanging on a door to be an intruder or thinking there is water on a hot road, due to the heat rising from the road. A delusional perception is where a genuine perception (ie. correctly sensed and interpreted) is given some additional (and typically bizarre) significance. [[Hypnagogic hallucination]]s and [[hypnopompia|hypnopompic hallucination]]s are considered normal phenomena. Hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up. Hallucinations may also be associated with [[Psychoactive drug|drug]] use (particularly [[Psychedelics, dissociatives and deliriants|hallucinogenic drug]]s), [[sleep deprivation]], psychosis or [[neurological disorder|neurological illness]].

*Hallucinations may involve any of the five senses:
:* Auditory
:* Gustatory
:* Olfactory
:* Tactile
:* Visual
* The most common type of hallucinations are auditory
* Patients may either dismiss the hallucination as being false, or they may identify them to be true

==Prevalence==

Studies have now shown hallucinatory experiences take place across the world. Previous studies, one as early as 1894,<ref>Sidgwick, H., Johnson, A, Myers, FWH et al (1894) Report on the census of hallucinations. ''Proceedings of the Society for Psychical Research'', 34, 25-394. </ref> have reported that approximately 10% of the population experience hallucinations. A recent survey of over 9,000 people<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11166087&dopt=Abstract Ohayon MM. (2000)] Prevalence of hallucinations and their pathological associations in the general population. ''Psychiatry Research'', 97(2-3), 153-64. </ref> reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survey, [[olfactory]] (smell) and [[gustatory]] (taste) hallucinations seem the most common in the general population.

==Auditory hallucinations==

[[Sound|Auditory]] hallucinations, particularly of one or more talking voices, are particularly associated with [[psychosis|psychotic]] disorders such as [[schizophrenia]]. and the presence may have significance in diagnosing these conditions, People not suffering from diagnosable [[mental illness]] may sometimes hear voices as well.<ref>{{cite web | url = http://www.livescience.com/humanbiology/060915_hearing_voices.html | title = Hearing Voices: Some People Like It | last = Thompson | first = Andrea | publisher = LiveScience.com | date = September 15, 2006|accessdate = 2006-11-25 }}</ref> The [[Hearing Voices Movement]] is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucinations include musical hallucinations, where people will hear music playing in their mind, usually songs they are familiar with. This can be caused by [[lesions]] on the [[brain stem]], occurring most often from [[strokes]], but also [[tumors]], sencephalitis, or [[abscesses]].<ref>{{cite web | url = http://www.sciencedaily.com/releases/2000/08/000809065249.htm | title = Rare Hallucinations Make Music In The Mind | publisher = ScienceDaily.com | date = August 9, 2000 | accessdate = 2006-12-31 }}</ref> Recent reports have also mentioned that it is possible to get musical hallucinations from listening to music for long periods of time.

==Visual hallucinations==

===Hypnagogic hallucination===
These hallucinations occur just before falling asleep and affect a surprising number of people in the population. The hallucinations can last from seconds to minutes, all the while the subject usually remains aware of the true nature of the images. These are usually associated with [[narcolepsy]], but can also affect normal minds. Hypnagogic hallucinations are sometimes associated with brainstem abnormalities, but this is rare.<ref name=manford> [http://brain.oxfordjournals.org/cgi/content/abstract/121/10/1819 Manford and Andermann (1998)] Complex visual hallucinations. Clinical and Neurobiological insights''Brain'', 121(10), 1819-1840.</ref>

===Peduncular hallucinosis===
Peduncular means pertaining to the [[peduncle]], which is a neural tract running to and from the [[pons]] on the [[brain stem]]. These hallucinations occur most often in the evenings, but not during drowsiness as in the case of hypnagogic hallucination. The subject is usually fully conscious and can interact with the hallucinatory characters for extended periods of time. As in the case of [[hypnagogic hallucinations]], insight into the nature of the images remains intact. The false images can occur in any part of the visual field, and are rarely [[wikt:polymodal|polymodal]].<ref name=manford/>

===Delirium tremens===
{{main|Delerium tremens}}
One of the most enigmatic forms of visual hallucinations are the highly variable, possibly polymodal [[delirium tremens]]. Individuals suffering from delerium tremens may be agitated and confused, especially in the later stages of this disease. Insight is gradually reduced with the progression of this disorder. Sleep is disturbed and occurs for a shorter period of time, with [[REM overflow]].<ref name=manford/>

===Parkinson's disease and Lewy body dementia===
[[Parkinson's disease]] is linked with [[Dementia with Lewy bodies|Lewy body dementia]] for their similar hallucinatory symptoms. The symptoms strike during the evening in any part of the visual field and are rarely polymodal. The segue into hallucinations may start with illusions<ref>[http://www.nytimes.com/2006/02/14/health/14case.html?ex=1151121600&en=04560d31e7926bee&ei=5070 Mark Derr (2006)] Marilyn and Me, "The New York Times" Feb. 14th, 2006 </ref> where sensory perception is greatly distorted, but no novel sensory information is present. These typically last for several minutes, during which time the subject may be either conscious and normal or drowsy/inaccessible. Insight into these hallucinations is usually preserved and [[REM sleep]] is usually reduced. Parkinson's disease is usually associated with a degraded [[substantia nigra]] pars compacta, but recent evidence suggests that PD affects a number of sites in the brain. Some places of noted degradation include the median raphe nuclei, the noradrenergic parts of the locus coeruleus and the [[cholinergic]] neurons in the parabrachial and pedunculopontine nuclei of the [[tegmentum]].<ref name=manford/>

===Migraine coma===
This type of hallucination is usually experienced during the recovery from a comatose state. The migraine coma can last for up to two days and a state of depression is sometimes comorbid. The hallucinations occur during states of full consciousness and insight into the hallucinatory nature of the images is preserved. It has been noted that ataxic lesions accompany the migraine coma.<ref name=manford/>

===Charles Bonnet syndrome===
[[Charles Bonnet syndrome]] is the name given to visual hallucinations experienced by blind patients. The hallucinations can usually be dispersed by opening or closing the eyelids until the visual images disappear. The hallucinations usually occur during the morning or evening, but are not dependent on low light conditions. These prolonged hallucinations usually do not disturb the patients very much as they are aware that they are hallucinating.<ref name=manford/>

===Focal epilepsy===
The visual hallucinations from focal epilepsy are characterized by being brief, and stereotyped. They are usually localized to one part of the visual field and last only a few seconds. Other epileptic features may present themselves between visual episodes. Consciousness is usually impaired in some way, but nevertheless insight into the hallucination is preserved. Usually this type of focal epilepsy is caused by a lesion in the posterior temporoparietal.<ref name=manford/>

==Tactile hallucinations==

Can be associated with substance use, such as someone who feels bugs crawling on them after a prolonged period of [[cocaine]] use.

==Scientific explanations==
Various theories have been put forward to explain the occurrence of hallucinations. When [[psychodynamic]] ([[Freud]]ian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes, thoughts and wants. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the [[brain]]. With reference to mental illness, the function (or dysfunction) of the [[neurotransmitter]] [[dopamine]] is thought to be particularly important.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505794&dopt=Abstract Kapur S. (2003)] Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. ''American Journal of Psychiatry'', 160(1), 13-23. </ref>
[[Psychology|Psychological]] research has argued that hallucinations may result from biases in what are known as [[metacognition|metacognitive]] abilities.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2404293&dopt=Abstract Bentall RP. (1990)] The illusion of reality: a review and integration of psychological research on hallucinations. ''Psychological Bulletin'', 107(1), 82-95. </ref> These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, [[memory|memories]], [[belief]]s and [[thought]]s). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences. Projection of an internal state or a person's own reaction to another may arise in the form of hallucinations, especially auditory hallucinations. A few scientists have argued that such hallucinations may be the result of other conscious thoughts.

==Stages of a hallucination==
#Emergence of surprising or warded-off memory or [[fantasy (psychology)|fantasy]] images <ref name=horowitz>Horowitz, Mardi J., M.D. “Hallucinations: An Information Processing Approach." In Siegel, Ronald K., Ph. D. and L. J. West, eds. ''Hallucinations: Behavior, Experience and Theory'' (1975). New York: John Wiley.</ref>
#Frequent reality checks <ref name=horowitz />
#Last vestige of insight as hallucinations become “real” <ref name=horowitz />
#Fantasy and distortion elaborated upon and confused with actual perception <ref name=horowitz />
#Internal-external boundaries destroyed and possible pantheistic experience <ref name=horowitz />

==Diagnosis==

=== History and Symptoms ===
* Timing of hallucinations
* Suicidal/homicidal ideations
* Drug regimen
* Work with psychiatrist (if patient cannot communicate mental and physical history)

=== Laboratory Findings ===
* [[Complete blood count]] ([[CBC]])
* [[Glucose]]
* [[Calcium]]
* [[Albumin]]
* [[Alkaline phosphatase]]
* [[Blood urea nitrogen]] ([[BUN]])/[[creatinine]]
* [[Liver function tests]] ([[LFT]]s)
* [[Magnesium]]
* [[Phosphate]]
* [[Toxicology]] screen
* [[Urinalysis]]
* [[Pulse oximetry]]
* Drug levels
* [[Folate levels]]
* [[Vitamin B12]]
* [[Antinuclear antibody]] ([[ANA]])
* [[Heavy metal]] screen
* [[Ammonia]]

=== Electrolyte and Biomarker Studies ===

* Electrolytes

=== Chest X Ray ===
* [[Chest X-ray]] (infectious etiologies)

=== Other Imaging Findings ===
* [[Electroencephalogram]] ([[EEG]])

=== Other Diagnostic Studies ===
* [[Lumbar puncture]]

== Differential Diagnosis ==

In alphabetical order. <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>

* Alcohol withdrawal
* [[Bipolar Disorder]]
* Central nervous system (CNS) infections
* [[Delirium]]
* [[Dementia]]
* [[Encephalitis]]
* Hallucinogenic syndromes (drug-induced)
* Heavy metal ingestion
* Lewy Body Dementia
* Mass lesions
* Occipital lobe injury
* Postpartum major depression
* [[Post Traumatic Stress Disorder|Post-Traumatic Stress Disorder]]
* Psychotic disorder
* Schizoaffective disorder
* [[Schizophrenia]]
* Schizophreniform disorder
* [[Seizures]]
* [[Systemic Lupus Erythematosus]]

{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Chemical / poisoning'''
|bgcolor="Beige"| [[Amanita muscaria]], [[Alcohol Withdrawal]], [[Carbon monoxide poisoning]], [[Alcoholism]], [[Mescaline]], [[Lysergic acid diethylamide]], [[Jenkem]], [[Nitrogen narcosis]], [[Laudanum]], [[Incapacitating agent]], [[Solanine]], [[Cocaine withdrawal ]], [[Bufotenin]], [[2C-T-2]], [[DESOXY]], [[3,4-Methylenedioxyamphetamine]], [[2C-E]], [[Dimethoxyamphetamine]], [[TOM (psychedelic)]], [[TOET (psychedelic)]], [[Substance D]], [[Ergot]], [[Henbane]], [[Phencyclidine]], [[Muscimol]], [[Datura tramonium]], [[Deadly nightshade]], [[Datura inoxia]], [[Datura wrightii]], [[Thujone]], [[5-Hydroxytryptophan]], [[2C-B]], [[2C-T-7]], [[Benzylpiperazine]], [[Candyflipping]], [[Mercury(II) chloride]], [[Ibotenic acid]], [[Khat]], [[PMA]], [[Amphetamine]], [[Psychedelic plants]], [[Psilocybin mushrooms]], [[Datura metel]], [[4-Acetoxy-DIPT]], [[Hallucinogen persisting perception disorder]], [[Formication]], [[Ergotism]], [[Ichthyoallyeinotoxism]], [[Abrin]], [[Delirium tremens]], [[Ascomycota]], [[Hawaiian baby woodrose]], [[Solanaceae]], [[Cocaine dependence]], [[5-F-AMT]], [[5-MeO-AMT]], [[Diisopropyltryptamine]], [[Dipropyltryptamine]], [[Marijuana intoxication]], [[Cannabis]], [[1,3-Butadiene ]], [[Acrylamide ]], [[Ammonium Sulfamate ]], [[Bromide]], [[Ether ]], [[Gasoline]], [[Glaze]], [[Sodium Monofluoroacetate ]], [[Solder]], [[Thallium]], [[Trichloroethane ]], [[Christmas Cherry poisoning]]

|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Procainamide ]], [[Alatrofloxacin Injection ]], [[Lomotil]], [[Fluphenazine ]], [[Acyclovir ]], [[Cefaclor]], [[Morphine Oral ]], [[Pentamidine Isethionate Injection ]], [[Alfentanil Hydrochloride Injection ]], [[Atropine]], [[Aspirin]], [[Zolpidem ]], [[Zaleplon ]], [[Voriconazole ]], [[Venlafaxine]], [[Trovafloxacin ]], [[Trihexyphenidyl ]], [[Trifluoperazine Oral ]], [[Tolterodine ]], [[Atomoxetine]], [[Tolcapone ]], [[Thiothixene Oral ]], [[Thioridazine ]], [[Benztropine Mesylate Oral ]], [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]], [[Bupropion]], [[Butorphanol Injection ]], [[Chlorpromazine ]], [[Clarithromycin]], [[Clomipramine ]], [[Dexmethylphenidate]], [[Dextroamphetamine]], [[Dextromethorphan]], [[Dimenhydrinate]], [[Efavirenz ]], [[Entacapone ]], [[Eszopiclone ]], [[Fluconazole ]], [[Flurazepam ]], [[Galantamine ]], [[Gatifloxacin ]], [[Gatifloxacin Injection ]], [[Haloperidol Oral ]], [[Ifosfamide ]], [[Ketorolac]], [[Levodopa]], [[Lithium ]], [[Loxapine Oral ]], [[Mefloquine ]], [[Memantine]], [[Methylphenidate Transdermal ]], [[Mirtazapine]], [[Modafinil ]], [[Nabilone ]], [[Nalbuphine injection ]], [[Naltrexone ]], [[Orphenadrine ]], [[Oxybutynin ]], [[Pemoline ]], [[Pergolide ]], [[Perphenazine oral ]], [[Phenelzine ]], [[Pramipexole ]], [[Prochlorperazine ]], [[Procyclidine ]], [[Promethazine ]], [[Ropinirole ]], [[Scopolamine patch ]], [[Selegiline ]], [[Sertraline]], [[Sodium oxybate ]], [[Solifenacin ]], [[Sufentanil citrate injection ]], [[Procyclidine hydrochloride]], [[3-Quinuclidinyl benzilate]], [[Ketamine]], [[Nalmefene]], [[Dezocine]], [[Dimethyltryptamine]], [[Scopolamine]], [[Methamphetamine]], [[Morphine]], [[Alprazolam]], [[Beta-blockers]], [[Buspirone]], [[Hydroxyzine]], [[Imipramine]], [[Lorazepam]], [[Phentermine]], [[Temazepam]], [[Tizanidine]], [[Triazolam]], [[Ethchlorvynol withdrawal ]], [[Serotonin syndrome]], [[Psychotomimetic]], [[Benzodiazepine withdrawal syndrome]], [[Ziconotide]], [[Diphenhydramine]], [[Dizocilpine]], [[NMDA receptor antagonist]], [[Pentazocine]], [[Opioid]], [[Ketazocine]], [[Valproate semisodium]], [[Ephedrine]], [[SSRI discontinuation syndrome]], [[Baclofen]], [[Flucytosine]], [[Oxamniquine]], [[Aciclovir]], [[Nitrazepam]], [[Loprazolam]], [[Lormetazepam]], [[Biperiden]], [[Clozapine]], [[Dantrolene]], [[Tricyclic antidepressant]], [[Zopiclone]], [[Propylhexedrine]], [[Dissociative drugs]], [[Toxidrome]], [[Tifluadom]], [[Phenazocine]], [[Etoxadrol]], [[Cabergoline]], [[Dexedrine overdose ]], [[Appian-Plutarch syndrome]], [[Isoniazid toxicity]], [[Ritalin overdose]], [[Barbiturate abuse]]

|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| [[Myxedematous psychosis]], [[Adrenal adenoma]], [[Adrenal Cancer ]], [[Adrenal gland hyperfunction]], [[Hyperadrenalism]], [[Adrenal incidentaloma]]

|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| [[Gluten-sensitive enteropathy associated conditions]]

|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| [[Creutzfeldt-Jakob Disease]], [[Rabies]], [[Acanthamoeba infection of the central nervous system]], [[Trypanosomiasis ]], [[Granulomatous amebic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Narcolepsy]], [[Encephalopathy]], [[Acute Disseminated Encephalomyelitis]], [[Migraine]], [[Dementia]], [[Delirium]], [[Complex partial seizure]], [[Arachnoid cyst]], [[Charles Bonnet syndrome]], [[Phantom eye syndrome]], [[Coats disease]], [[Entoptic phenomenon]], [[Closed-eye hallucination]], [[Cortical blindness]], [[High altitude cerebral edema]], [[Cerebral edema]], [[False memory]], [[Sleep deprivation]], [[Morvan's syndrome]], [[Fatal familial insomnia]], [[Endaural phenomena]], [[Parkinson plus syndrome]], [[Dementia with Lewy bodies]], [[Peduncular hallucinosis]], [[Temporal lobe epilepsy]], [[Aura (symptom)]], [[Parkinson's disease]], [[Traumatic brain injury]], [[Sensory deprivation]], [[Brain tumor]], [[Binswanger's disease]], [[Stroke]], [[Dana syndrome]], [[Lhermitte-McAlpine syndrome]], [[Autoimmune limbic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Nutritional / Metabolic'''
|bgcolor="Beige"| [[Porphyria]], [[Variegate porphyria]]

|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Opthalmologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
|bgcolor="Beige"| [[Pseudoephedrine]], [[Caffeine]], [[Mazindol]]

|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Schizophrenia]], [[Hypnagogia]], [[Kleine-Levin syndrome]], [[Clinical lycanthropy]], [[Paris syndrome]], [[Homosexual panic]], [[Ganser syndrome]], [[Psychosis]], [[Psychotic depression]], [[Clinical depression]], [[Stendhal syndrome]], [[Alice in Wonderland syndrome]], [[Delusional disorder]], [[Oneirophrenia]], [[Postnatal depression]], [[Avolition]], [[Disorganized schizophrenia]], [[Schizoaffective disorder]], [[Mania]]

|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
|bgcolor="Beige"| [[Hypercalcemia]], [[Hypomagnesemia]]

|-
|-bgcolor="LightSteelBlue"
| '''Rheum / Immune / Allergy'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| [[Visual snow]], [[Apparitional experience]], [[Hallucinations in the sane]], [[Extreme fatigue]], [[Extreme physical stress]], [[Dehydration ]]

|-
|}

== Treatment ==
* Treat underlying etiologies

=== Acute Pharmacotherapies ===
* [[Antipsychotic drugs]]
* [[Benzodiazepine]]s

== See also ==
* [[Apparitional experience]]
* [[Closed-eye hallucination]]
* [[Delusion]]
* [[Dimethyltryptamine]]
* [[Dream]]
* [[Focal seizures]]
* [[Folie à deux]]
* Form constant
* [[Hallucinations in the sane]]
* [[Illusion]]
* Imaginary friend
* [[Phantom eye syndrome]]
* [[Psychedelics, dissociatives and deliriants|Hallucinogenic drug]]
* [[Psychosis]]
* [[Salvia divinorum]]
* Simulated reality

== References ==
{{reflist|2}}

{{SIB}}
{{WH}}
{{WS}}

[[Category:Signs and symptoms]]
[[Category:Psychiatry]]
[[Category:Mature chapter]]

[[cs:Halucinace]]
[[da:Hallucination]]
[[de:Halluzination]]
[[et:Hallutsinatsioon]]
[[es:Alucinación]]
[[fr:Hallucination]]
[[ga:Bréagchéadfa]]
[[it:Allucinazione]]
[[ku:Hallûsînasyon]]
[[he:הזיה]]
[[ka:ჰალუცინაცია]]
[[lb:Halluzinatioun]]
[[lt:Haliucinacija]]
[[hu:Hallucináció]]
[[mk:Халуцинација]]
[[nl:Hallucinatie]]
[[ja:幻覚]]
[[no:Hallusinasjon]]
[[pt:Alucinação]]
[[ru:Галлюцинация]]
[[simple:Hallucination]]
[[sk:Halucinácia]]
[[sl:Halucinacija]]
[[sr:Халуцинација]]
[[pl:Halucynacja]]
[[tr:Halüsinasyon]]
[[fi:Hallusinaatio]]
[[sv:Hallucination]]
[[ur:خطاۓ حس]]
[[zh:幻觉]]

Hallucination

2012-07-05T18:11:12Z

Aiham Jbeli: /* Differential Diagnosis */

'''For patient information click [[Hallucination (patient information)|here]]'''

{{Infobox_Disease |
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OMIM = |
MedlinePlus = 003258 |
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{{SI}}
{{CMG}}

==Overview==
A '''hallucination''' is a perception in the absence of a [[stimulus (physiology)|stimulus]] that the person may or may not believe is real (Hallucinations are psychotic symptoms that occur when patients perceive stimuli that do not exist). Hallucinations may occur in any sensory modality—[[visual system|visual]], [[auditory system|auditory]], [[olfaction|olfactory]], [[taste|gustatory]], [[tactition|tactile]], [[proprioception|proprioceptive]], [[equilibrioception|equilibrioceptive]], [[nociception|nociceptive]], [[thermoception|thermoceptive]]. Hallucinations are different from illusions. In an illusory experience, a genuine sensation is attributed to an incorrect cause, misinterpreting a coat hanging on a door to be an intruder or thinking there is water on a hot road, due to the heat rising from the road. A delusional perception is where a genuine perception (ie. correctly sensed and interpreted) is given some additional (and typically bizarre) significance. [[Hypnagogic hallucination]]s and [[hypnopompia|hypnopompic hallucination]]s are considered normal phenomena. Hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up. Hallucinations may also be associated with [[Psychoactive drug|drug]] use (particularly [[Psychedelics, dissociatives and deliriants|hallucinogenic drug]]s), [[sleep deprivation]], psychosis or [[neurological disorder|neurological illness]].

*Hallucinations may involve any of the five senses:
:* Auditory
:* Gustatory
:* Olfactory
:* Tactile
:* Visual
* The most common type of hallucinations are auditory
* Patients may either dismiss the hallucination as being false, or they may identify them to be true

==Prevalence==

Studies have now shown hallucinatory experiences take place across the world. Previous studies, one as early as 1894,<ref>Sidgwick, H., Johnson, A, Myers, FWH et al (1894) Report on the census of hallucinations. ''Proceedings of the Society for Psychical Research'', 34, 25-394. </ref> have reported that approximately 10% of the population experience hallucinations. A recent survey of over 9,000 people<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11166087&dopt=Abstract Ohayon MM. (2000)] Prevalence of hallucinations and their pathological associations in the general population. ''Psychiatry Research'', 97(2-3), 153-64. </ref> reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survey, [[olfactory]] (smell) and [[gustatory]] (taste) hallucinations seem the most common in the general population.

==Auditory hallucinations==

[[Sound|Auditory]] hallucinations, particularly of one or more talking voices, are particularly associated with [[psychosis|psychotic]] disorders such as [[schizophrenia]]. and the presence may have significance in diagnosing these conditions, People not suffering from diagnosable [[mental illness]] may sometimes hear voices as well.<ref>{{cite web | url = http://www.livescience.com/humanbiology/060915_hearing_voices.html | title = Hearing Voices: Some People Like It | last = Thompson | first = Andrea | publisher = LiveScience.com | date = September 15, 2006|accessdate = 2006-11-25 }}</ref> The [[Hearing Voices Movement]] is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucinations include musical hallucinations, where people will hear music playing in their mind, usually songs they are familiar with. This can be caused by [[lesions]] on the [[brain stem]], occurring most often from [[strokes]], but also [[tumors]], sencephalitis, or [[abscesses]].<ref>{{cite web | url = http://www.sciencedaily.com/releases/2000/08/000809065249.htm | title = Rare Hallucinations Make Music In The Mind | publisher = ScienceDaily.com | date = August 9, 2000 | accessdate = 2006-12-31 }}</ref> Recent reports have also mentioned that it is possible to get musical hallucinations from listening to music for long periods of time.

==Visual hallucinations==

===Hypnagogic hallucination===
These hallucinations occur just before falling asleep and affect a surprising number of people in the population. The hallucinations can last from seconds to minutes, all the while the subject usually remains aware of the true nature of the images. These are usually associated with [[narcolepsy]], but can also affect normal minds. Hypnagogic hallucinations are sometimes associated with brainstem abnormalities, but this is rare.<ref name=manford> [http://brain.oxfordjournals.org/cgi/content/abstract/121/10/1819 Manford and Andermann (1998)] Complex visual hallucinations. Clinical and Neurobiological insights''Brain'', 121(10), 1819-1840.</ref>

===Peduncular hallucinosis===
Peduncular means pertaining to the [[peduncle]], which is a neural tract running to and from the [[pons]] on the [[brain stem]]. These hallucinations occur most often in the evenings, but not during drowsiness as in the case of hypnagogic hallucination. The subject is usually fully conscious and can interact with the hallucinatory characters for extended periods of time. As in the case of [[hypnagogic hallucinations]], insight into the nature of the images remains intact. The false images can occur in any part of the visual field, and are rarely [[wikt:polymodal|polymodal]].<ref name=manford/>

===Delirium tremens===
{{main|Delerium tremens}}
One of the most enigmatic forms of visual hallucinations are the highly variable, possibly polymodal [[delirium tremens]]. Individuals suffering from delerium tremens may be agitated and confused, especially in the later stages of this disease. Insight is gradually reduced with the progression of this disorder. Sleep is disturbed and occurs for a shorter period of time, with [[REM overflow]].<ref name=manford/>

===Parkinson's disease and Lewy body dementia===
[[Parkinson's disease]] is linked with [[Dementia with Lewy bodies|Lewy body dementia]] for their similar hallucinatory symptoms. The symptoms strike during the evening in any part of the visual field and are rarely polymodal. The segue into hallucinations may start with illusions<ref>[http://www.nytimes.com/2006/02/14/health/14case.html?ex=1151121600&en=04560d31e7926bee&ei=5070 Mark Derr (2006)] Marilyn and Me, "The New York Times" Feb. 14th, 2006 </ref> where sensory perception is greatly distorted, but no novel sensory information is present. These typically last for several minutes, during which time the subject may be either conscious and normal or drowsy/inaccessible. Insight into these hallucinations is usually preserved and [[REM sleep]] is usually reduced. Parkinson's disease is usually associated with a degraded [[substantia nigra]] pars compacta, but recent evidence suggests that PD affects a number of sites in the brain. Some places of noted degradation include the median raphe nuclei, the noradrenergic parts of the locus coeruleus and the [[cholinergic]] neurons in the parabrachial and pedunculopontine nuclei of the [[tegmentum]].<ref name=manford/>

===Migraine coma===
This type of hallucination is usually experienced during the recovery from a comatose state. The migraine coma can last for up to two days and a state of depression is sometimes comorbid. The hallucinations occur during states of full consciousness and insight into the hallucinatory nature of the images is preserved. It has been noted that ataxic lesions accompany the migraine coma.<ref name=manford/>

===Charles Bonnet syndrome===
[[Charles Bonnet syndrome]] is the name given to visual hallucinations experienced by blind patients. The hallucinations can usually be dispersed by opening or closing the eyelids until the visual images disappear. The hallucinations usually occur during the morning or evening, but are not dependent on low light conditions. These prolonged hallucinations usually do not disturb the patients very much as they are aware that they are hallucinating.<ref name=manford/>

===Focal epilepsy===
The visual hallucinations from focal epilepsy are characterized by being brief, and stereotyped. They are usually localized to one part of the visual field and last only a few seconds. Other epileptic features may present themselves between visual episodes. Consciousness is usually impaired in some way, but nevertheless insight into the hallucination is preserved. Usually this type of focal epilepsy is caused by a lesion in the posterior temporoparietal.<ref name=manford/>

==Tactile hallucinations==

Can be associated with substance use, such as someone who feels bugs crawling on them after a prolonged period of [[cocaine]] use.

==Scientific explanations==
Various theories have been put forward to explain the occurrence of hallucinations. When [[psychodynamic]] ([[Freud]]ian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes, thoughts and wants. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the [[brain]]. With reference to mental illness, the function (or dysfunction) of the [[neurotransmitter]] [[dopamine]] is thought to be particularly important.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505794&dopt=Abstract Kapur S. (2003)] Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. ''American Journal of Psychiatry'', 160(1), 13-23. </ref>
[[Psychology|Psychological]] research has argued that hallucinations may result from biases in what are known as [[metacognition|metacognitive]] abilities.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2404293&dopt=Abstract Bentall RP. (1990)] The illusion of reality: a review and integration of psychological research on hallucinations. ''Psychological Bulletin'', 107(1), 82-95. </ref> These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, [[memory|memories]], [[belief]]s and [[thought]]s). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences. Projection of an internal state or a person's own reaction to another may arise in the form of hallucinations, especially auditory hallucinations. A few scientists have argued that such hallucinations may be the result of other conscious thoughts.

==Stages of a hallucination==
#Emergence of surprising or warded-off memory or [[fantasy (psychology)|fantasy]] images <ref name=horowitz>Horowitz, Mardi J., M.D. “Hallucinations: An Information Processing Approach." In Siegel, Ronald K., Ph. D. and L. J. West, eds. ''Hallucinations: Behavior, Experience and Theory'' (1975). New York: John Wiley.</ref>
#Frequent reality checks <ref name=horowitz />
#Last vestige of insight as hallucinations become “real” <ref name=horowitz />
#Fantasy and distortion elaborated upon and confused with actual perception <ref name=horowitz />
#Internal-external boundaries destroyed and possible pantheistic experience <ref name=horowitz />

==Diagnosis==

=== History and Symptoms ===
* Timing of hallucinations
* Suicidal/homicidal ideations
* Drug regimen
* Work with psychiatrist (if patient cannot communicate mental and physical history)

=== Laboratory Findings ===
* [[Complete blood count]] ([[CBC]])
* [[Glucose]]
* [[Calcium]]
* [[Albumin]]
* [[Alkaline phosphatase]]
* [[Blood urea nitrogen]] ([[BUN]])/[[creatinine]]
* [[Liver function tests]] ([[LFT]]s)
* [[Magnesium]]
* [[Phosphate]]
* [[Toxicology]] screen
* [[Urinalysis]]
* [[Pulse oximetry]]
* Drug levels
* [[Folate levels]]
* [[Vitamin B12]]
* [[Antinuclear antibody]] ([[ANA]])
* [[Heavy metal]] screen
* [[Ammonia]]

=== Electrolyte and Biomarker Studies ===

* Electrolytes

=== Chest X Ray ===
* [[Chest X-ray]] (infectious etiologies)

=== Other Imaging Findings ===
* [[Electroencephalogram]] ([[EEG]])

=== Other Diagnostic Studies ===
* [[Lumbar puncture]]

== Differential Diagnosis ==

In alphabetical order. <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>

* Alcohol withdrawal
* [[Bipolar Disorder]]
* Central nervous system (CNS) infections
* [[Delirium]]
* [[Dementia]]
* [[Encephalitis]]
* Hallucinogenic syndromes (drug-induced)
* Heavy metal ingestion
* Lewy Body Dementia
* Mass lesions
* Occipital lobe injury
* Postpartum major depression
* [[Post Traumatic Stress Disorder|Post-Traumatic Stress Disorder]]
* Psychotic disorder
* Schizoaffective disorder
* [[Schizophrenia]]
* Schizophreniform disorder
* [[Seizures]]
* [[Systemic Lupus Erythematosus]]

{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Chemical / poisoning'''
|bgcolor="Beige"| [[Amanita muscaria]], [[Alcohol Withdrawal]], [[Carbon monoxide poisoning]], [[Alcoholism]], [[Mescaline]], [[Lysergic acid diethylamide]], [[Jenkem]], [[Nitrogen narcosis]], [[Laudanum]], [[Incapacitating agent]], [[Solanine]], [[Cocaine withdrawal ]], [[Bufotenin]], [[2C-T-2]], [[DESOXY]], [[3,4-Methylenedioxyamphetamine]], [[2C-E]], [[Dimethoxyamphetamine]], [[TOM (psychedelic)]], [[TOET (psychedelic)]], [[Substance D]], [[Ergot]], [[Henbane]], [[Phencyclidine]], [[Muscimol]], [[Datura tramonium]], [[Deadly nightshade]], [[Datura inoxia]], [[Datura wrightii]], [[Thujone]], [[5-Hydroxytryptophan]], [[2C-B]], [[2C-T-7]], [[Benzylpiperazine]], [[Candyflipping]], [[Mercury(II) chloride]], [[Ibotenic acid]], [[Khat]], [[PMA]], [[Amphetamine]], [[Psychedelic plants]], [[Psilocybin mushrooms]], [[Datura metel]], [[4-Acetoxy-DIPT]], [[Hallucinogen persisting perception disorder]], [[Formication]], [[Ergotism]], [[Ichthyoallyeinotoxism]], [[Abrin]], [[Delirium tremens]], [[Ascomycota]], [[Hawaiian baby woodrose]], [[Solanaceae]], [[Cocaine dependence]], [[5-F-AMT]], [[5-MeO-AMT]], [[Diisopropyltryptamine]], [[Dipropyltryptamine]], [[Marijuana intoxication]], [[Cannabis]], [[1,3-Butadiene ]], [[Acrylamide ]], [[Ammonium Sulfamate ]], [[Bromide]], [[Ether ]], [[Gasoline]], [[Glaze]], [[Sodium Monofluoroacetate ]], [[Solder]], [[Thallium]], [[Trichloroethane ]], [[Christmas Cherry poisoning]]

|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Procainamide ]], [[Alatrofloxacin Injection ]], [[Lomotil]], [[Fluphenazine ]], [[Acyclovir ]], [[Cefaclor]], [[Morphine Oral ]], [[Pentamidine Isethionate Injection ]], [[Alfentanil Hydrochloride Injection ]], [[Atropine]], [[Aspirin]], [[Zolpidem ]], [[Zaleplon ]], [[Voriconazole ]], [[Venlafaxine]], [[Trovafloxacin ]], [[Trihexyphenidyl ]], [[Trifluoperazine Oral ]], [[Tolterodine ]], [[Atomoxetine]], [[Tolcapone ]], [[Thiothixene Oral ]], [[Thioridazine ]], [[Benztropine Mesylate Oral ]], [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]], [[Bupropion]], [[Butorphanol Injection ]], [[Chlorpromazine ]], [[Clarithromycin]], [[Clomipramine ]], [[Dexmethylphenidate]], [[Dextroamphetamine]], [[Dextromethorphan]], [[Dimenhydrinate]], [[Efavirenz ]], [[Entacapone ]], [[Eszopiclone ]], [[Fluconazole ]], [[Flurazepam ]], [[Galantamine ]], [[Gatifloxacin ]], [[Gatifloxacin Injection ]], [[Haloperidol Oral ]], [[Ifosfamide ]], [[Ketorolac]], [[Levodopa]], [[Lithium ]], [[Loxapine Oral ]], [[Mefloquine ]], [[Memantine]], [[Methylphenidate Transdermal ]], [[Mirtazapine]], [[Modafinil ]], [[Nabilone ]], [[Nalbuphine injection ]], [[Naltrexone ]], [[Orphenadrine ]], [[Oxybutynin ]], [[Pemoline ]], [[Pergolide ]], [[Perphenazine oral ]], [[Phenelzine ]], [[Pramipexole ]], [[Prochlorperazine ]], [[Procyclidine ]], [[Promethazine ]], [[Ropinirole ]], [[Scopolamine patch ]], [[Selegiline ]], [[Sertraline]], [[Sodium oxybate ]], [[Solifenacin ]], [[Sufentanil citrate injection ]], [[Procyclidine hydrochloride]], [[3-Quinuclidinyl benzilate]], [[Ketamine]], [[Nalmefene]], [[Dezocine]], [[Dimethyltryptamine]], [[Scopolamine]], [[Methamphetamine]], [[Morphine]], [[Alprazolam]], [[Beta-blockers]], [[Buspirone]], [[Hydroxyzine]], [[Imipramine]], [[Lorazepam]], [[Phentermine]], [[Temazepam]], [[Tizanidine]], [[Triazolam]], [[Ethchlorvynol withdrawal ]], [[Serotonin syndrome]], [[Psychotomimetic]], [[Benzodiazepine withdrawal syndrome]], [[Ziconotide]], [[Diphenhydramine]], [[Dizocilpine]], [[NMDA receptor antagonist]], [[Pentazocine]], [[Opioid]], [[Ketazocine]], [[Valproate semisodium]], [[Ephedrine]], [[SSRI discontinuation syndrome]], [[Baclofen]], [[Flucytosine]], [[Oxamniquine]], [[Aciclovir]], [[Nitrazepam]], [[Loprazolam]], [[Lormetazepam]], [[Biperiden]], [[Clozapine]], [[Dantrolene]], [[Tricyclic antidepressant]], [[Zopiclone]], [[Propylhexedrine]], [[Dissociative drugs]], [[Toxidrome]], [[Tifluadom]], [[Phenazocine]], [[Etoxadrol]], [[Cabergoline]], [[Dexedrine overdose ]], [[Appian-Plutarch syndrome]], [[Isoniazid toxicity]], [[Ritalin overdose]], [[Barbiturate abuse]]

|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| [[Myxedematous psychosis]], [[Adrenal adenoma]], [[Adrenal Cancer ]], [[Adrenal gland hyperfunction]], [[Hyperadrenalism]], [[Adrenal incidentaloma]]

|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| [[Gluten-sensitive enteropathy associated conditions]]

|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| [[Creutzfeldt-Jakob Disease]], [[Rabies]], [[Acanthamoeba infection of the central nervous system]], [[Trypanosomiasis ]], [[Granulomatous amebic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Narcolepsy]], [[Encephalopathy]], [[Acute Disseminated Encephalomyelitis]], [[Migraine]], [[Dementia]], [[Delirium]], [[Complex partial seizure]], [[Arachnoid cyst]], [[Charles Bonnet syndrome]], [[Phantom eye syndrome]], [[Coats disease]], [[Entoptic phenomenon]], [[Closed-eye hallucination]], [[Cortical blindness]], [[High altitude cerebral edema]], [[Cerebral edema]], [[False memory]], [[Sleep deprivation]], [[Morvan's syndrome]], [[Fatal familial insomnia]], [[Endaural phenomena]], [[Parkinson plus syndrome]], [[Dementia with Lewy bodies]], [[Peduncular hallucinosis]], [[Temporal lobe epilepsy]], [[Aura (symptom)]], [[Parkinson's disease]], [[Traumatic brain injury]], [[Sensory deprivation]], [[Brain tumor]], [[Binswanger's disease]], [[Stroke]], [[Dana syndrome]], [[Lhermitte-McAlpine syndrome]], [[Autoimmune limbic encephalitis]]

|-
|-bgcolor="LightSteelBlue"
| '''Nutritional / Metabolic'''
|bgcolor="Beige"| [[Porphyria]], [[Variegate porphyria]]

|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Opthalmologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
|bgcolor="Beige"| [[Pseudoephedrine]], [[Caffeine]], [[Mazindol]]

|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Schizophrenia]], [[Hypnagogia]], [[Kleine-Levin syndrome]], [[Clinical lycanthropy]], [[Paris syndrome]], [[Homosexual panic]], [[Ganser syndrome]], [[Psychosis]], [[Psychotic depression]], [[Clinical depression]], [[Stendhal syndrome]], [[Alice in Wonderland syndrome]], [[Delusional disorder]], [[Oneirophrenia]], [[Postnatal depression]], [[Avolition]], [[Disorganized schizophrenia]], [[Schizoaffective disorder]], [[Mania]]

|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
|bgcolor="Beige"| [[Hypercalcemia]], [[Hypomagnesemia]]

|-
|-bgcolor="LightSteelBlue"
| '''Rheum / Immune / Allergy'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| [[Visual snow]], [[Apparitional experience]], [[Hallucinations in the sane]]

|-
|}

== Treatment ==
* Treat underlying etiologies

=== Acute Pharmacotherapies ===
* [[Antipsychotic drugs]]
* [[Benzodiazepine]]s

== See also ==
* [[Apparitional experience]]
* [[Closed-eye hallucination]]
* [[Delusion]]
* [[Dimethyltryptamine]]
* [[Dream]]
* [[Focal seizures]]
* [[Folie à deux]]
* Form constant
* [[Hallucinations in the sane]]
* [[Illusion]]
* Imaginary friend
* [[Phantom eye syndrome]]
* [[Psychedelics, dissociatives and deliriants|Hallucinogenic drug]]
* [[Psychosis]]
* [[Salvia divinorum]]
* Simulated reality

== References ==
{{reflist|2}}

{{SIB}}
{{WH}}
{{WS}}

[[Category:Signs and symptoms]]
[[Category:Psychiatry]]
[[Category:Mature chapter]]

[[cs:Halucinace]]
[[da:Hallucination]]
[[de:Halluzination]]
[[et:Hallutsinatsioon]]
[[es:Alucinación]]
[[fr:Hallucination]]
[[ga:Bréagchéadfa]]
[[it:Allucinazione]]
[[ku:Hallûsînasyon]]
[[he:הזיה]]
[[ka:ჰალუცინაცია]]
[[lb:Halluzinatioun]]
[[lt:Haliucinacija]]
[[hu:Hallucináció]]
[[mk:Халуцинација]]
[[nl:Hallucinatie]]
[[ja:幻覚]]
[[no:Hallusinasjon]]
[[pt:Alucinação]]
[[ru:Галлюцинация]]
[[simple:Hallucination]]
[[sk:Halucinácia]]
[[sl:Halucinacija]]
[[sr:Халуцинација]]
[[pl:Halucynacja]]
[[tr:Halüsinasyon]]
[[fi:Hallusinaatio]]
[[sv:Hallucination]]
[[ur:خطاۓ حس]]
[[zh:幻觉]]

Hallucination

2012-07-05T15:15:35Z

Aiham Jbeli: /* Differential Diagnosis */

'''For patient information click [[Hallucination (patient information)|here]]'''

{{Infobox_Disease |
Name = {{PAGENAME}} |
Image = |
Caption = |
DiseasesDB = |
ICD10 = |
ICD9 = |
ICDO = |
OMIM = |
MedlinePlus = 003258 |
eMedicineSubj = |
eMedicineTopic = |
MeshID = |
}}
{{SI}}
{{CMG}}

==Overview==
A '''hallucination''' is a perception in the absence of a [[stimulus (physiology)|stimulus]] that the person may or may not believe is real (Hallucinations are psychotic symptoms that occur when patients perceive stimuli that do not exist). Hallucinations may occur in any sensory modality—[[visual system|visual]], [[auditory system|auditory]], [[olfaction|olfactory]], [[taste|gustatory]], [[tactition|tactile]], [[proprioception|proprioceptive]], [[equilibrioception|equilibrioceptive]], [[nociception|nociceptive]], [[thermoception|thermoceptive]]. Hallucinations are different from illusions. In an illusory experience, a genuine sensation is attributed to an incorrect cause, misinterpreting a coat hanging on a door to be an intruder or thinking there is water on a hot road, due to the heat rising from the road. A delusional perception is where a genuine perception (ie. correctly sensed and interpreted) is given some additional (and typically bizarre) significance. [[Hypnagogic hallucination]]s and [[hypnopompia|hypnopompic hallucination]]s are considered normal phenomena. Hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up. Hallucinations may also be associated with [[Psychoactive drug|drug]] use (particularly [[Psychedelics, dissociatives and deliriants|hallucinogenic drug]]s), [[sleep deprivation]], psychosis or [[neurological disorder|neurological illness]].

*Hallucinations may involve any of the five senses:
:* Auditory
:* Gustatory
:* Olfactory
:* Tactile
:* Visual
* The most common type of hallucinations are auditory
* Patients may either dismiss the hallucination as being false, or they may identify them to be true

==Prevalence==

Studies have now shown hallucinatory experiences take place across the world. Previous studies, one as early as 1894,<ref>Sidgwick, H., Johnson, A, Myers, FWH et al (1894) Report on the census of hallucinations. ''Proceedings of the Society for Psychical Research'', 34, 25-394. </ref> have reported that approximately 10% of the population experience hallucinations. A recent survey of over 9,000 people<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11166087&dopt=Abstract Ohayon MM. (2000)] Prevalence of hallucinations and their pathological associations in the general population. ''Psychiatry Research'', 97(2-3), 153-64. </ref> reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survey, [[olfactory]] (smell) and [[gustatory]] (taste) hallucinations seem the most common in the general population.

==Auditory hallucinations==

[[Sound|Auditory]] hallucinations, particularly of one or more talking voices, are particularly associated with [[psychosis|psychotic]] disorders such as [[schizophrenia]]. and the presence may have significance in diagnosing these conditions, People not suffering from diagnosable [[mental illness]] may sometimes hear voices as well.<ref>{{cite web | url = http://www.livescience.com/humanbiology/060915_hearing_voices.html | title = Hearing Voices: Some People Like It | last = Thompson | first = Andrea | publisher = LiveScience.com | date = September 15, 2006|accessdate = 2006-11-25 }}</ref> The [[Hearing Voices Movement]] is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucinations include musical hallucinations, where people will hear music playing in their mind, usually songs they are familiar with. This can be caused by [[lesions]] on the [[brain stem]], occurring most often from [[strokes]], but also [[tumors]], sencephalitis, or [[abscesses]].<ref>{{cite web | url = http://www.sciencedaily.com/releases/2000/08/000809065249.htm | title = Rare Hallucinations Make Music In The Mind | publisher = ScienceDaily.com | date = August 9, 2000 | accessdate = 2006-12-31 }}</ref> Recent reports have also mentioned that it is possible to get musical hallucinations from listening to music for long periods of time.

==Visual hallucinations==

===Hypnagogic hallucination===
These hallucinations occur just before falling asleep and affect a surprising number of people in the population. The hallucinations can last from seconds to minutes, all the while the subject usually remains aware of the true nature of the images. These are usually associated with [[narcolepsy]], but can also affect normal minds. Hypnagogic hallucinations are sometimes associated with brainstem abnormalities, but this is rare.<ref name=manford> [http://brain.oxfordjournals.org/cgi/content/abstract/121/10/1819 Manford and Andermann (1998)] Complex visual hallucinations. Clinical and Neurobiological insights''Brain'', 121(10), 1819-1840.</ref>

===Peduncular hallucinosis===
Peduncular means pertaining to the [[peduncle]], which is a neural tract running to and from the [[pons]] on the [[brain stem]]. These hallucinations occur most often in the evenings, but not during drowsiness as in the case of hypnagogic hallucination. The subject is usually fully conscious and can interact with the hallucinatory characters for extended periods of time. As in the case of [[hypnagogic hallucinations]], insight into the nature of the images remains intact. The false images can occur in any part of the visual field, and are rarely [[wikt:polymodal|polymodal]].<ref name=manford/>

===Delirium tremens===
{{main|Delerium tremens}}
One of the most enigmatic forms of visual hallucinations are the highly variable, possibly polymodal [[delirium tremens]]. Individuals suffering from delerium tremens may be agitated and confused, especially in the later stages of this disease. Insight is gradually reduced with the progression of this disorder. Sleep is disturbed and occurs for a shorter period of time, with [[REM overflow]].<ref name=manford/>

===Parkinson's disease and Lewy body dementia===
[[Parkinson's disease]] is linked with [[Dementia with Lewy bodies|Lewy body dementia]] for their similar hallucinatory symptoms. The symptoms strike during the evening in any part of the visual field and are rarely polymodal. The segue into hallucinations may start with illusions<ref>[http://www.nytimes.com/2006/02/14/health/14case.html?ex=1151121600&en=04560d31e7926bee&ei=5070 Mark Derr (2006)] Marilyn and Me, "The New York Times" Feb. 14th, 2006 </ref> where sensory perception is greatly distorted, but no novel sensory information is present. These typically last for several minutes, during which time the subject may be either conscious and normal or drowsy/inaccessible. Insight into these hallucinations is usually preserved and [[REM sleep]] is usually reduced. Parkinson's disease is usually associated with a degraded [[substantia nigra]] pars compacta, but recent evidence suggests that PD affects a number of sites in the brain. Some places of noted degradation include the median raphe nuclei, the noradrenergic parts of the locus coeruleus and the [[cholinergic]] neurons in the parabrachial and pedunculopontine nuclei of the [[tegmentum]].<ref name=manford/>

===Migraine coma===
This type of hallucination is usually experienced during the recovery from a comatose state. The migraine coma can last for up to two days and a state of depression is sometimes comorbid. The hallucinations occur during states of full consciousness and insight into the hallucinatory nature of the images is preserved. It has been noted that ataxic lesions accompany the migraine coma.<ref name=manford/>

===Charles Bonnet syndrome===
[[Charles Bonnet syndrome]] is the name given to visual hallucinations experienced by blind patients. The hallucinations can usually be dispersed by opening or closing the eyelids until the visual images disappear. The hallucinations usually occur during the morning or evening, but are not dependent on low light conditions. These prolonged hallucinations usually do not disturb the patients very much as they are aware that they are hallucinating.<ref name=manford/>

===Focal epilepsy===
The visual hallucinations from focal epilepsy are characterized by being brief, and stereotyped. They are usually localized to one part of the visual field and last only a few seconds. Other epileptic features may present themselves between visual episodes. Consciousness is usually impaired in some way, but nevertheless insight into the hallucination is preserved. Usually this type of focal epilepsy is caused by a lesion in the posterior temporoparietal.<ref name=manford/>

==Tactile hallucinations==

Can be associated with substance use, such as someone who feels bugs crawling on them after a prolonged period of [[cocaine]] use.

==Scientific explanations==
Various theories have been put forward to explain the occurrence of hallucinations. When [[psychodynamic]] ([[Freud]]ian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes, thoughts and wants. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the [[brain]]. With reference to mental illness, the function (or dysfunction) of the [[neurotransmitter]] [[dopamine]] is thought to be particularly important.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505794&dopt=Abstract Kapur S. (2003)] Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. ''American Journal of Psychiatry'', 160(1), 13-23. </ref>
[[Psychology|Psychological]] research has argued that hallucinations may result from biases in what are known as [[metacognition|metacognitive]] abilities.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2404293&dopt=Abstract Bentall RP. (1990)] The illusion of reality: a review and integration of psychological research on hallucinations. ''Psychological Bulletin'', 107(1), 82-95. </ref> These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, [[memory|memories]], [[belief]]s and [[thought]]s). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences. Projection of an internal state or a person's own reaction to another may arise in the form of hallucinations, especially auditory hallucinations. A few scientists have argued that such hallucinations may be the result of other conscious thoughts.

==Stages of a hallucination==
#Emergence of surprising or warded-off memory or [[fantasy (psychology)|fantasy]] images <ref name=horowitz>Horowitz, Mardi J., M.D. “Hallucinations: An Information Processing Approach." In Siegel, Ronald K., Ph. D. and L. J. West, eds. ''Hallucinations: Behavior, Experience and Theory'' (1975). New York: John Wiley.</ref>
#Frequent reality checks <ref name=horowitz />
#Last vestige of insight as hallucinations become “real” <ref name=horowitz />
#Fantasy and distortion elaborated upon and confused with actual perception <ref name=horowitz />
#Internal-external boundaries destroyed and possible pantheistic experience <ref name=horowitz />

==Diagnosis==

=== History and Symptoms ===
* Timing of hallucinations
* Suicidal/homicidal ideations
* Drug regimen
* Work with psychiatrist (if patient cannot communicate mental and physical history)

=== Laboratory Findings ===
* [[Complete blood count]] ([[CBC]])
* [[Glucose]]
* [[Calcium]]
* [[Albumin]]
* [[Alkaline phosphatase]]
* [[Blood urea nitrogen]] ([[BUN]])/[[creatinine]]
* [[Liver function tests]] ([[LFT]]s)
* [[Magnesium]]
* [[Phosphate]]
* [[Toxicology]] screen
* [[Urinalysis]]
* [[Pulse oximetry]]
* Drug levels
* [[Folate levels]]
* [[Vitamin B12]]
* [[Antinuclear antibody]] ([[ANA]])
* [[Heavy metal]] screen
* [[Ammonia]]

=== Electrolyte and Biomarker Studies ===

* Electrolytes

=== Chest X Ray ===
* [[Chest X-ray]] (infectious etiologies)

=== Other Imaging Findings ===
* [[Electroencephalogram]] ([[EEG]])

=== Other Diagnostic Studies ===
* [[Lumbar puncture]]

== Differential Diagnosis ==

In alphabetical order. <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>

* Alcohol withdrawal
* [[Bipolar Disorder]]
* Central nervous system (CNS) infections
* [[Delirium]]
* [[Dementia]]
* [[Encephalitis]]
* Hallucinogenic syndromes (drug-induced)
* Heavy metal ingestion
* Lewy Body Dementia
* Mass lesions
* Occipital lobe injury
* Postpartum major depression
* [[Post Traumatic Stress Disorder|Post-Traumatic Stress Disorder]]
* Psychotic disorder
* Schizoaffective disorder
* [[Schizophrenia]]
* Schizophreniform disorder
* [[Seizures]]
* [[Systemic Lupus Erythematosus]]

{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Chemical / poisoning'''
|bgcolor="Beige"| [[Amanita muscaria]], [[Alcohol Withdrawal]], [[Carbon monoxide poisoning]], [[Alcoholism]], [[Mescaline]], [[Lysergic acid diethylamide]], [[Jenkem]], [[Nitrogen narcosis]], [[Laudanum]], [[Incapacitating agent]], [[Solanine]], [[Cocaine withdrawal ]], [[Bufotenin]], [[2C-T-2]], [[DESOXY]], [[3,4-Methylenedioxyamphetamine]], [[2C-E]], [[Dimethoxyamphetamine]], [[TOM (psychedelic)]], [[TOET (psychedelic)]], [[Substance D]], [[Ergot]], [[Henbane]], [[Phencyclidine]], [[Muscimol]], [[Datura tramonium]], [[Deadly nightshade]], [[Datura inoxia]], [[Datura wrightii]], [[Thujone]], [[5-Hydroxytryptophan]], [[2C-B]], [[2C-T-7]], [[Benzylpiperazine]], [[Candyflipping]], [[Mercury(II) chloride]], [[Ibotenic acid]], [[Khat]], [[PMA]], [[Amphetamine]], [[Psychedelic plants]], [[Psilocybin mushrooms]], [[Datura metel]], [[4-Acetoxy-DIPT]], [[Hallucinogen persisting perception disorder]], [[Formication]], [[Ergotism]], [[Ichthyoallyeinotoxism]], [[Abrin]], [[Delirium tremens]], [[Ascomycota]], [[Hawaiian baby woodrose]], [[Solanaceae]], [[Cocaine dependence]], [[5-F-AMT]], [[5-MeO-AMT]], [[Diisopropyltryptamine]], [[Dipropyltryptamine]]

|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Procainamide ]], [[Alatrofloxacin Injection ]], [[Lomotil]], [[Fluphenazine ]], [[Acyclovir ]], [[Cefaclor]], [[Morphine Oral ]], [[Pentamidine Isethionate Injection ]], [[Alfentanil Hydrochloride Injection ]], [[Atropine]], [[Aspirin]], [[Zolpidem ]], [[Zaleplon ]], [[Voriconazole ]], [[Venlafaxine]], [[Trovafloxacin ]], [[Trihexyphenidyl ]], [[Trifluoperazine Oral ]], [[Tolterodine ]], [[Atomoxetine]], [[Tolcapone ]], [[Thiothixene Oral ]], [[Thioridazine ]], [[Benztropine Mesylate Oral ]], [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]], [[Bupropion]], [[Butorphanol Injection ]], [[Chlorpromazine ]], [[Clarithromycin]], [[Clomipramine ]], [[Dexmethylphenidate]], [[Dextroamphetamine]], [[Dextromethorphan]], [[Dimenhydrinate]], [[Efavirenz ]], [[Entacapone ]], [[Eszopiclone ]], [[Fluconazole ]], [[Flurazepam ]], [[Galantamine ]], [[Gatifloxacin ]], [[Gatifloxacin Injection ]], [[Haloperidol Oral ]], [[Ifosfamide ]], [[Ketorolac]], [[Levodopa]], [[Lithium ]], [[Loxapine Oral ]], [[Mefloquine ]], [[Memantine]], [[Methylphenidate Transdermal ]], [[Mirtazapine]], [[Modafinil ]], [[Nabilone ]], [[Nalbuphine injection ]], [[Naltrexone ]], [[Orphenadrine ]], [[Oxybutynin ]], [[Pemoline ]], [[Pergolide ]], [[Perphenazine oral ]], [[Phenelzine ]], [[Pramipexole ]], [[Prochlorperazine ]], [[Procyclidine ]], [[Promethazine ]], [[Ropinirole ]], [[Scopolamine patch ]], [[Selegiline ]], [[Sertraline]], [[Sodium oxybate ]], [[Solifenacin ]], [[Sufentanil citrate injection ]], [[Procyclidine hydrochloride]], [[3-Quinuclidinyl benzilate]], [[Ketamine]], [[Nalmefene]], [[Dezocine]], [[Dimethyltryptamine]], [[Scopolamine]], [[Methamphetamine]], [[Morphine]], [[Alprazolam]], [[Beta-blockers]], [[Buspirone]], [[Hydroxyzine]], [[Imipramine]], [[Lorazepam]], [[Phentermine]], [[Temazepam]], [[Tizanidine]], [[Triazolam]], [[Ethchlorvynol withdrawal ]], [[Serotonin syndrome]], [[Psychotomimetic]], [[Benzodiazepine withdrawal syndrome]], [[Ziconotide]], [[Diphenhydramine]], [[Dizocilpine]], [[NMDA receptor antagonist]], [[Pentazocine]], [[Opioid]], [[Ketazocine]], [[Valproate semisodium]], [[Ephedrine]], [[SSRI discontinuation syndrome]], [[Baclofen]], [[Flucytosine]], [[Oxamniquine]], [[Aciclovir]], [[Nitrazepam]], [[Loprazolam]], [[Lormetazepam]], [[Biperiden]], [[Clozapine]], [[Dantrolene]], [[Tricyclic antidepressant]], [[Zopiclone]], [[Propylhexedrine]], [[Dissociative drugs]], [[Toxidrome]], [[Tifluadom]], [[Phenazocine]], [[Etoxadrol]], [[Cabergoline]]
|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| [[Myxedematous psychosis]]

|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| [[Gluten-sensitive enteropathy associated conditions]]

|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| [[Creutzfeldt-Jakob Disease]], [[Rabies]]

|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Narcolepsy]], [[Encephalopathy]], [[Acute Disseminated Encephalomyelitis]], [[Migraine]], [[Dementia]], [[Delirium]], [[Complex partial seizure]], [[Arachnoid cyst]], [[Charles Bonnet syndrome]], [[Phantom eye syndrome]], [[Coats disease]], [[Entoptic phenomenon]], [[Closed-eye hallucination]], [[Cortical blindness]], [[High altitude cerebral edema]], [[Cerebral edema]], [[False memory]], [[Sleep deprivation]], [[Morvan's syndrome]], [[Fatal familial insomnia]], [[Endaural phenomena]], [[Parkinson plus syndrome]], [[Dementia with Lewy bodies]], [[Peduncular hallucinosis]], [[Temporal lobe epilepsy]], [[Aura (symptom)]], [[Parkinson's disease]], [[Traumatic brain injury]], [[Sensory deprivation]]

|-
|-bgcolor="LightSteelBlue"
| '''Nutritional / Metabolic'''
|bgcolor="Beige"| [[Porphyria]], [[Variegate porphyria]]

|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Opthalmologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
|bgcolor="Beige"| [[Pseudoephedrine]], [[Caffeine]], [[Mazindol]]

|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Schizophrenia]], [[Hypnagogia]], [[Kleine-Levin syndrome]], [[Clinical lycanthropy]], [[Paris syndrome]], [[Homosexual panic]], [[Ganser syndrome]], [[Psychosis]], [[Psychotic depression]], [[Clinical depression]], [[Stendhal syndrome]], [[Alice in Wonderland syndrome]], [[Delusional disorder]], [[Oneirophrenia]], [[Postnatal depression]], [[Avolition]], [[Disorganized schizophrenia]], [[Schizoaffective disorder]], [[Mania]]

|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
|bgcolor="Beige"| [[Hypercalcemia]], [[Hypomagnesemia]]

|-
|-bgcolor="LightSteelBlue"
| '''Rheum / Immune / Allergy'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| [[Visual snow]], [[Apparitional experience]], [[Hallucinations in the sane]]

|-
|}

== Treatment ==
* Treat underlying etiologies

=== Acute Pharmacotherapies ===
* [[Antipsychotic drugs]]
* [[Benzodiazepine]]s

== See also ==
* [[Apparitional experience]]
* [[Closed-eye hallucination]]
* [[Delusion]]
* [[Dimethyltryptamine]]
* [[Dream]]
* [[Focal seizures]]
* [[Folie à deux]]
* Form constant
* [[Hallucinations in the sane]]
* [[Illusion]]
* Imaginary friend
* [[Phantom eye syndrome]]
* [[Psychedelics, dissociatives and deliriants|Hallucinogenic drug]]
* [[Psychosis]]
* [[Salvia divinorum]]
* Simulated reality

== References ==
{{reflist|2}}

{{SIB}}
{{WH}}
{{WS}}

[[Category:Signs and symptoms]]
[[Category:Psychiatry]]
[[Category:Mature chapter]]

[[cs:Halucinace]]
[[da:Hallucination]]
[[de:Halluzination]]
[[et:Hallutsinatsioon]]
[[es:Alucinación]]
[[fr:Hallucination]]
[[ga:Bréagchéadfa]]
[[it:Allucinazione]]
[[ku:Hallûsînasyon]]
[[he:הזיה]]
[[ka:ჰალუცინაცია]]
[[lb:Halluzinatioun]]
[[lt:Haliucinacija]]
[[hu:Hallucináció]]
[[mk:Халуцинација]]
[[nl:Hallucinatie]]
[[ja:幻覚]]
[[no:Hallusinasjon]]
[[pt:Alucinação]]
[[ru:Галлюцинация]]
[[simple:Hallucination]]
[[sk:Halucinácia]]
[[sl:Halucinacija]]
[[sr:Халуцинација]]
[[pl:Halucynacja]]
[[tr:Halüsinasyon]]
[[fi:Hallusinaatio]]
[[sv:Hallucination]]
[[ur:خطاۓ حس]]
[[zh:幻觉]]

Hallucination

2012-07-05T15:05:02Z

Aiham Jbeli: /* Differential Diagnosis */

'''For patient information click [[Hallucination (patient information)|here]]'''

{{Infobox_Disease |
Name = {{PAGENAME}} |
Image = |
Caption = |
DiseasesDB = |
ICD10 = |
ICD9 = |
ICDO = |
OMIM = |
MedlinePlus = 003258 |
eMedicineSubj = |
eMedicineTopic = |
MeshID = |
}}
{{SI}}
{{CMG}}

==Overview==
A '''hallucination''' is a perception in the absence of a [[stimulus (physiology)|stimulus]] that the person may or may not believe is real (Hallucinations are psychotic symptoms that occur when patients perceive stimuli that do not exist). Hallucinations may occur in any sensory modality—[[visual system|visual]], [[auditory system|auditory]], [[olfaction|olfactory]], [[taste|gustatory]], [[tactition|tactile]], [[proprioception|proprioceptive]], [[equilibrioception|equilibrioceptive]], [[nociception|nociceptive]], [[thermoception|thermoceptive]]. Hallucinations are different from illusions. In an illusory experience, a genuine sensation is attributed to an incorrect cause, misinterpreting a coat hanging on a door to be an intruder or thinking there is water on a hot road, due to the heat rising from the road. A delusional perception is where a genuine perception (ie. correctly sensed and interpreted) is given some additional (and typically bizarre) significance. [[Hypnagogic hallucination]]s and [[hypnopompia|hypnopompic hallucination]]s are considered normal phenomena. Hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up. Hallucinations may also be associated with [[Psychoactive drug|drug]] use (particularly [[Psychedelics, dissociatives and deliriants|hallucinogenic drug]]s), [[sleep deprivation]], psychosis or [[neurological disorder|neurological illness]].

*Hallucinations may involve any of the five senses:
:* Auditory
:* Gustatory
:* Olfactory
:* Tactile
:* Visual
* The most common type of hallucinations are auditory
* Patients may either dismiss the hallucination as being false, or they may identify them to be true

==Prevalence==

Studies have now shown hallucinatory experiences take place across the world. Previous studies, one as early as 1894,<ref>Sidgwick, H., Johnson, A, Myers, FWH et al (1894) Report on the census of hallucinations. ''Proceedings of the Society for Psychical Research'', 34, 25-394. </ref> have reported that approximately 10% of the population experience hallucinations. A recent survey of over 9,000 people<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11166087&dopt=Abstract Ohayon MM. (2000)] Prevalence of hallucinations and their pathological associations in the general population. ''Psychiatry Research'', 97(2-3), 153-64. </ref> reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survey, [[olfactory]] (smell) and [[gustatory]] (taste) hallucinations seem the most common in the general population.

==Auditory hallucinations==

[[Sound|Auditory]] hallucinations, particularly of one or more talking voices, are particularly associated with [[psychosis|psychotic]] disorders such as [[schizophrenia]]. and the presence may have significance in diagnosing these conditions, People not suffering from diagnosable [[mental illness]] may sometimes hear voices as well.<ref>{{cite web | url = http://www.livescience.com/humanbiology/060915_hearing_voices.html | title = Hearing Voices: Some People Like It | last = Thompson | first = Andrea | publisher = LiveScience.com | date = September 15, 2006|accessdate = 2006-11-25 }}</ref> The [[Hearing Voices Movement]] is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucinations include musical hallucinations, where people will hear music playing in their mind, usually songs they are familiar with. This can be caused by [[lesions]] on the [[brain stem]], occurring most often from [[strokes]], but also [[tumors]], sencephalitis, or [[abscesses]].<ref>{{cite web | url = http://www.sciencedaily.com/releases/2000/08/000809065249.htm | title = Rare Hallucinations Make Music In The Mind | publisher = ScienceDaily.com | date = August 9, 2000 | accessdate = 2006-12-31 }}</ref> Recent reports have also mentioned that it is possible to get musical hallucinations from listening to music for long periods of time.

==Visual hallucinations==

===Hypnagogic hallucination===
These hallucinations occur just before falling asleep and affect a surprising number of people in the population. The hallucinations can last from seconds to minutes, all the while the subject usually remains aware of the true nature of the images. These are usually associated with [[narcolepsy]], but can also affect normal minds. Hypnagogic hallucinations are sometimes associated with brainstem abnormalities, but this is rare.<ref name=manford> [http://brain.oxfordjournals.org/cgi/content/abstract/121/10/1819 Manford and Andermann (1998)] Complex visual hallucinations. Clinical and Neurobiological insights''Brain'', 121(10), 1819-1840.</ref>

===Peduncular hallucinosis===
Peduncular means pertaining to the [[peduncle]], which is a neural tract running to and from the [[pons]] on the [[brain stem]]. These hallucinations occur most often in the evenings, but not during drowsiness as in the case of hypnagogic hallucination. The subject is usually fully conscious and can interact with the hallucinatory characters for extended periods of time. As in the case of [[hypnagogic hallucinations]], insight into the nature of the images remains intact. The false images can occur in any part of the visual field, and are rarely [[wikt:polymodal|polymodal]].<ref name=manford/>

===Delirium tremens===
{{main|Delerium tremens}}
One of the most enigmatic forms of visual hallucinations are the highly variable, possibly polymodal [[delirium tremens]]. Individuals suffering from delerium tremens may be agitated and confused, especially in the later stages of this disease. Insight is gradually reduced with the progression of this disorder. Sleep is disturbed and occurs for a shorter period of time, with [[REM overflow]].<ref name=manford/>

===Parkinson's disease and Lewy body dementia===
[[Parkinson's disease]] is linked with [[Dementia with Lewy bodies|Lewy body dementia]] for their similar hallucinatory symptoms. The symptoms strike during the evening in any part of the visual field and are rarely polymodal. The segue into hallucinations may start with illusions<ref>[http://www.nytimes.com/2006/02/14/health/14case.html?ex=1151121600&en=04560d31e7926bee&ei=5070 Mark Derr (2006)] Marilyn and Me, "The New York Times" Feb. 14th, 2006 </ref> where sensory perception is greatly distorted, but no novel sensory information is present. These typically last for several minutes, during which time the subject may be either conscious and normal or drowsy/inaccessible. Insight into these hallucinations is usually preserved and [[REM sleep]] is usually reduced. Parkinson's disease is usually associated with a degraded [[substantia nigra]] pars compacta, but recent evidence suggests that PD affects a number of sites in the brain. Some places of noted degradation include the median raphe nuclei, the noradrenergic parts of the locus coeruleus and the [[cholinergic]] neurons in the parabrachial and pedunculopontine nuclei of the [[tegmentum]].<ref name=manford/>

===Migraine coma===
This type of hallucination is usually experienced during the recovery from a comatose state. The migraine coma can last for up to two days and a state of depression is sometimes comorbid. The hallucinations occur during states of full consciousness and insight into the hallucinatory nature of the images is preserved. It has been noted that ataxic lesions accompany the migraine coma.<ref name=manford/>

===Charles Bonnet syndrome===
[[Charles Bonnet syndrome]] is the name given to visual hallucinations experienced by blind patients. The hallucinations can usually be dispersed by opening or closing the eyelids until the visual images disappear. The hallucinations usually occur during the morning or evening, but are not dependent on low light conditions. These prolonged hallucinations usually do not disturb the patients very much as they are aware that they are hallucinating.<ref name=manford/>

===Focal epilepsy===
The visual hallucinations from focal epilepsy are characterized by being brief, and stereotyped. They are usually localized to one part of the visual field and last only a few seconds. Other epileptic features may present themselves between visual episodes. Consciousness is usually impaired in some way, but nevertheless insight into the hallucination is preserved. Usually this type of focal epilepsy is caused by a lesion in the posterior temporoparietal.<ref name=manford/>

==Tactile hallucinations==

Can be associated with substance use, such as someone who feels bugs crawling on them after a prolonged period of [[cocaine]] use.

==Scientific explanations==
Various theories have been put forward to explain the occurrence of hallucinations. When [[psychodynamic]] ([[Freud]]ian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes, thoughts and wants. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the [[brain]]. With reference to mental illness, the function (or dysfunction) of the [[neurotransmitter]] [[dopamine]] is thought to be particularly important.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505794&dopt=Abstract Kapur S. (2003)] Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. ''American Journal of Psychiatry'', 160(1), 13-23. </ref>
[[Psychology|Psychological]] research has argued that hallucinations may result from biases in what are known as [[metacognition|metacognitive]] abilities.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2404293&dopt=Abstract Bentall RP. (1990)] The illusion of reality: a review and integration of psychological research on hallucinations. ''Psychological Bulletin'', 107(1), 82-95. </ref> These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, [[memory|memories]], [[belief]]s and [[thought]]s). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences. Projection of an internal state or a person's own reaction to another may arise in the form of hallucinations, especially auditory hallucinations. A few scientists have argued that such hallucinations may be the result of other conscious thoughts.

==Stages of a hallucination==
#Emergence of surprising or warded-off memory or [[fantasy (psychology)|fantasy]] images <ref name=horowitz>Horowitz, Mardi J., M.D. “Hallucinations: An Information Processing Approach." In Siegel, Ronald K., Ph. D. and L. J. West, eds. ''Hallucinations: Behavior, Experience and Theory'' (1975). New York: John Wiley.</ref>
#Frequent reality checks <ref name=horowitz />
#Last vestige of insight as hallucinations become “real” <ref name=horowitz />
#Fantasy and distortion elaborated upon and confused with actual perception <ref name=horowitz />
#Internal-external boundaries destroyed and possible pantheistic experience <ref name=horowitz />

==Diagnosis==

=== History and Symptoms ===
* Timing of hallucinations
* Suicidal/homicidal ideations
* Drug regimen
* Work with psychiatrist (if patient cannot communicate mental and physical history)

=== Laboratory Findings ===
* [[Complete blood count]] ([[CBC]])
* [[Glucose]]
* [[Calcium]]
* [[Albumin]]
* [[Alkaline phosphatase]]
* [[Blood urea nitrogen]] ([[BUN]])/[[creatinine]]
* [[Liver function tests]] ([[LFT]]s)
* [[Magnesium]]
* [[Phosphate]]
* [[Toxicology]] screen
* [[Urinalysis]]
* [[Pulse oximetry]]
* Drug levels
* [[Folate levels]]
* [[Vitamin B12]]
* [[Antinuclear antibody]] ([[ANA]])
* [[Heavy metal]] screen
* [[Ammonia]]

=== Electrolyte and Biomarker Studies ===

* Electrolytes

=== Chest X Ray ===
* [[Chest X-ray]] (infectious etiologies)

=== Other Imaging Findings ===
* [[Electroencephalogram]] ([[EEG]])

=== Other Diagnostic Studies ===
* [[Lumbar puncture]]

== Differential Diagnosis ==

In alphabetical order. <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>

* Alcohol withdrawal
* [[Bipolar Disorder]]
* Central nervous system (CNS) infections
* [[Delirium]]
* [[Dementia]]
* [[Encephalitis]]
* Hallucinogenic syndromes (drug-induced)
* Heavy metal ingestion
* Lewy Body Dementia
* Mass lesions
* Occipital lobe injury
* Postpartum major depression
* [[Post Traumatic Stress Disorder|Post-Traumatic Stress Disorder]]
* Psychotic disorder
* Schizoaffective disorder
* [[Schizophrenia]]
* Schizophreniform disorder
* [[Seizures]]
* [[Systemic Lupus Erythematosus]]

{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Chemical / poisoning'''
|bgcolor="Beige"| [[Amanita muscaria]], [[Alcohol Withdrawal]], [[Carbon monoxide poisoning]], [[Alcoholism]], [[Mescaline]], [[Lysergic acid diethylamide]], [[Jenkem]], [[Nitrogen narcosis]], [[Laudanum]], [[Incapacitating agent]], [[Solanine]], [[Cocaine withdrawal ]], [[Bufotenin]], [[2C-T-2]], [[DESOXY]], [[3,4-Methylenedioxyamphetamine]], [[2C-E]], [[Dimethoxyamphetamine]], [[TOM (psychedelic)]], [[TOET (psychedelic)]], [[Substance D]], [[Ergot]], [[Henbane]], [[Phencyclidine]], [[Muscimol]], [[Datura tramonium]], [[Deadly nightshade]], [[Datura inoxia]], [[Datura wrightii]], [[Thujone]], [[5-Hydroxytryptophan]], [[2C-B]], [[2C-T-7]], [[Benzylpiperazine]], [[Candyflipping]], [[Mercury(II) chloride]], [[Ibotenic acid]], [[Khat]], [[PMA]], [[Amphetamine]], [[Psychedelic plants]], [[Psilocybin mushrooms]], [[Datura metel]], [[4-Acetoxy-DIPT]], [[Hallucinogen persisting perception disorder]], [[Formication]], [[Ergotism]], [[Ichthyoallyeinotoxism]], [[Abrin]], [[Delirium tremens]], [[Ascomycota]], [[Hawaiian baby woodrose]], [[Solanaceae]], [[Cocaine dependence]], [[5-F-AMT]], [[5-MeO-AMT]], [[Diisopropyltryptamine]], [[Dipropyltryptamine]]

|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Procainamide ]], [[Alatrofloxacin Injection ]], [[Lomotil]], [[Fluphenazine ]], [[Acyclovir ]], [[Cefaclor]], [[Morphine Oral ]], [[Pentamidine Isethionate Injection ]], [[Alfentanil Hydrochloride Injection ]], [[Atropine]], [[Aspirin]], [[Zolpidem ]], [[Zaleplon ]], [[Voriconazole ]], [[Venlafaxine]], [[Trovafloxacin ]], [[Trihexyphenidyl ]], [[Trifluoperazine Oral ]], [[Tolterodine ]], [[Atomoxetine]], [[Tolcapone ]], [[Thiothixene Oral ]], [[Thioridazine ]], [[Benztropine Mesylate Oral ]], [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]], [[Bupropion]], [[Butorphanol Injection ]], [[Chlorpromazine ]], [[Clarithromycin]], [[Clomipramine ]], [[Dexmethylphenidate]], [[Dextroamphetamine]], [[Dextromethorphan]], [[Dimenhydrinate]], [[Efavirenz ]], [[Entacapone ]], [[Eszopiclone ]], [[Fluconazole ]], [[Flurazepam ]], [[Galantamine ]], [[Gatifloxacin ]], [[Gatifloxacin Injection ]], [[Haloperidol Oral ]], [[Ifosfamide ]], [[Ketorolac]], [[Levodopa]], [[Lithium ]], [[Loxapine Oral ]], [[Mefloquine ]], [[Memantine]], [[Methylphenidate Transdermal ]], [[Mirtazapine]], [[Modafinil ]], [[Nabilone ]], [[Nalbuphine injection ]], [[Naltrexone ]], [[Orphenadrine ]], [[Oxybutynin ]], [[Pemoline ]], [[Pergolide ]], [[Perphenazine oral ]], [[Phenelzine ]], [[Pramipexole ]], [[Prochlorperazine ]], [[Procyclidine ]], [[Promethazine ]], [[Ropinirole ]], [[Scopolamine patch ]], [[Selegiline ]], [[Sertraline]], [[Sodium oxybate ]], [[Solifenacin ]], [[Sufentanil citrate injection ]], [[Procyclidine hydrochloride]], [[3-Quinuclidinyl benzilate]], [[Ketamine]], [[Nalmefene]], [[Dezocine]], [[Dimethyltryptamine]], [[Scopolamine]], [[Methamphetamine]], [[Morphine]], [[Alprazolam]], [[Beta-blockers]], [[Buspirone]], [[Hydroxyzine]], [[Imipramine]], [[Lorazepam]], [[Phentermine]], [[Temazepam]], [[Tizanidine]], [[Triazolam]], [[Ethchlorvynol withdrawal ]], [[Serotonin syndrome]], [[Psychotomimetic]], [[Benzodiazepine withdrawal syndrome]], [[Ziconotide]], [[Diphenhydramine]], [[Dizocilpine]], [[NMDA receptor antagonist]], [[Pentazocine]], [[Opioid]], [[Ketazocine]], [[Valproate semisodium]], [[Ephedrine]], [[SSRI discontinuation syndrome]], [[Baclofen]], [[Flucytosine]], [[Oxamniquine]], [[Aciclovir]], [[Nitrazepam]], [[Loprazolam]], [[Lormetazepam]], [[Biperiden]], [[Clozapine]], [[Dantrolene]], [[Tricyclic antidepressant]], [[Zopiclone]], [[Propylhexedrine]], [[Dissociative drugs]], [[Toxidrome]], [[Tifluadom]], [[Phenazocine]], [[Etoxadrol]], [[Cabergoline]]
|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Narcolepsy]], [[Encephalopathy]], [[Acute Disseminated Encephalomyelitis]], [[Migraine]], [[Dementia]], [[Delirium]], [[Complex partial seizure]], [[Arachnoid cyst]], [[Charles Bonnet syndrome]], [[Phantom eye syndrome]], [[Coats disease]], [[Entoptic phenomenon]], [[Closed-eye hallucination]], [[Cortical blindness]], [[High altitude cerebral edema]], [[Cerebral edema]], [[False memory]], [[Sleep deprivation]], [[Morvan's syndrome]], [[Fatal familial insomnia]], [[Endaural phenomena]], [[Parkinson plus syndrome]], [[Dementia with Lewy bodies]], [[Peduncular hallucinosis]], [[Temporal lobe epilepsy]], [[Aura (symptom)]], [[Parkinson's disease]], [[Traumatic brain injury]], [[Sensory deprivation]]

|-
|-bgcolor="LightSteelBlue"
| '''Nutritional / Metabolic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Opthalmologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Schizophrenia]], [[Hypnagogia]], [[Kleine-Levin syndrome]], [[Clinical lycanthropy]], [[Paris syndrome]], [[Homosexual panic]], [[Ganser syndrome]], [[Psychosis]], [[Psychotic depression]], [[Clinical depression]], [[Stendhal syndrome]], [[Alice in Wonderland syndrome]], [[Delusional disorder]], [[Oneirophrenia]], [[Postnatal depression]], [[Avolition]], [[Disorganized schizophrenia]], [[Schizoaffective disorder]], [[Mania]]

|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Rheum / Immune / Allergy'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| No underlying causes
|-
|}

== Treatment ==
* Treat underlying etiologies

=== Acute Pharmacotherapies ===
* [[Antipsychotic drugs]]
* [[Benzodiazepine]]s

== See also ==
* [[Apparitional experience]]
* [[Closed-eye hallucination]]
* [[Delusion]]
* [[Dimethyltryptamine]]
* [[Dream]]
* [[Focal seizures]]
* [[Folie à deux]]
* Form constant
* [[Hallucinations in the sane]]
* [[Illusion]]
* Imaginary friend
* [[Phantom eye syndrome]]
* [[Psychedelics, dissociatives and deliriants|Hallucinogenic drug]]
* [[Psychosis]]
* [[Salvia divinorum]]
* Simulated reality

== References ==
{{reflist|2}}

{{SIB}}
{{WH}}
{{WS}}

[[Category:Signs and symptoms]]
[[Category:Psychiatry]]
[[Category:Mature chapter]]

[[cs:Halucinace]]
[[da:Hallucination]]
[[de:Halluzination]]
[[et:Hallutsinatsioon]]
[[es:Alucinación]]
[[fr:Hallucination]]
[[ga:Bréagchéadfa]]
[[it:Allucinazione]]
[[ku:Hallûsînasyon]]
[[he:הזיה]]
[[ka:ჰალუცინაცია]]
[[lb:Halluzinatioun]]
[[lt:Haliucinacija]]
[[hu:Hallucináció]]
[[mk:Халуцинација]]
[[nl:Hallucinatie]]
[[ja:幻覚]]
[[no:Hallusinasjon]]
[[pt:Alucinação]]
[[ru:Галлюцинация]]
[[simple:Hallucination]]
[[sk:Halucinácia]]
[[sl:Halucinacija]]
[[sr:Халуцинација]]
[[pl:Halucynacja]]
[[tr:Halüsinasyon]]
[[fi:Hallusinaatio]]
[[sv:Hallucination]]
[[ur:خطاۓ حس]]
[[zh:幻觉]]

Hallucination

2012-07-05T14:32:24Z

Aiham Jbeli: /* Differential Diagnosis */

'''For patient information click [[Hallucination (patient information)|here]]'''

{{Infobox_Disease |
Name = {{PAGENAME}} |
Image = |
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ICD10 = |
ICD9 = |
ICDO = |
OMIM = |
MedlinePlus = 003258 |
eMedicineSubj = |
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}}
{{SI}}
{{CMG}}

==Overview==
A '''hallucination''' is a perception in the absence of a [[stimulus (physiology)|stimulus]] that the person may or may not believe is real (Hallucinations are psychotic symptoms that occur when patients perceive stimuli that do not exist). Hallucinations may occur in any sensory modality—[[visual system|visual]], [[auditory system|auditory]], [[olfaction|olfactory]], [[taste|gustatory]], [[tactition|tactile]], [[proprioception|proprioceptive]], [[equilibrioception|equilibrioceptive]], [[nociception|nociceptive]], [[thermoception|thermoceptive]]. Hallucinations are different from illusions. In an illusory experience, a genuine sensation is attributed to an incorrect cause, misinterpreting a coat hanging on a door to be an intruder or thinking there is water on a hot road, due to the heat rising from the road. A delusional perception is where a genuine perception (ie. correctly sensed and interpreted) is given some additional (and typically bizarre) significance. [[Hypnagogic hallucination]]s and [[hypnopompia|hypnopompic hallucination]]s are considered normal phenomena. Hypnagogic hallucinations can occur as one is falling asleep and hypnopompic hallucinations occur when one is waking up. Hallucinations may also be associated with [[Psychoactive drug|drug]] use (particularly [[Psychedelics, dissociatives and deliriants|hallucinogenic drug]]s), [[sleep deprivation]], psychosis or [[neurological disorder|neurological illness]].

*Hallucinations may involve any of the five senses:
:* Auditory
:* Gustatory
:* Olfactory
:* Tactile
:* Visual
* The most common type of hallucinations are auditory
* Patients may either dismiss the hallucination as being false, or they may identify them to be true

==Prevalence==

Studies have now shown hallucinatory experiences take place across the world. Previous studies, one as early as 1894,<ref>Sidgwick, H., Johnson, A, Myers, FWH et al (1894) Report on the census of hallucinations. ''Proceedings of the Society for Psychical Research'', 34, 25-394. </ref> have reported that approximately 10% of the population experience hallucinations. A recent survey of over 9,000 people<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11166087&dopt=Abstract Ohayon MM. (2000)] Prevalence of hallucinations and their pathological associations in the general population. ''Psychiatry Research'', 97(2-3), 153-64. </ref> reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survey, [[olfactory]] (smell) and [[gustatory]] (taste) hallucinations seem the most common in the general population.

==Auditory hallucinations==

[[Sound|Auditory]] hallucinations, particularly of one or more talking voices, are particularly associated with [[psychosis|psychotic]] disorders such as [[schizophrenia]]. and the presence may have significance in diagnosing these conditions, People not suffering from diagnosable [[mental illness]] may sometimes hear voices as well.<ref>{{cite web | url = http://www.livescience.com/humanbiology/060915_hearing_voices.html | title = Hearing Voices: Some People Like It | last = Thompson | first = Andrea | publisher = LiveScience.com | date = September 15, 2006|accessdate = 2006-11-25 }}</ref> The [[Hearing Voices Movement]] is a support and advocacy group for people who hallucinate voices, but do not otherwise show signs of mental illness or impairment. Other types of auditory hallucinations include musical hallucinations, where people will hear music playing in their mind, usually songs they are familiar with. This can be caused by [[lesions]] on the [[brain stem]], occurring most often from [[strokes]], but also [[tumors]], sencephalitis, or [[abscesses]].<ref>{{cite web | url = http://www.sciencedaily.com/releases/2000/08/000809065249.htm | title = Rare Hallucinations Make Music In The Mind | publisher = ScienceDaily.com | date = August 9, 2000 | accessdate = 2006-12-31 }}</ref> Recent reports have also mentioned that it is possible to get musical hallucinations from listening to music for long periods of time.

==Visual hallucinations==

===Hypnagogic hallucination===
These hallucinations occur just before falling asleep and affect a surprising number of people in the population. The hallucinations can last from seconds to minutes, all the while the subject usually remains aware of the true nature of the images. These are usually associated with [[narcolepsy]], but can also affect normal minds. Hypnagogic hallucinations are sometimes associated with brainstem abnormalities, but this is rare.<ref name=manford> [http://brain.oxfordjournals.org/cgi/content/abstract/121/10/1819 Manford and Andermann (1998)] Complex visual hallucinations. Clinical and Neurobiological insights''Brain'', 121(10), 1819-1840.</ref>

===Peduncular hallucinosis===
Peduncular means pertaining to the [[peduncle]], which is a neural tract running to and from the [[pons]] on the [[brain stem]]. These hallucinations occur most often in the evenings, but not during drowsiness as in the case of hypnagogic hallucination. The subject is usually fully conscious and can interact with the hallucinatory characters for extended periods of time. As in the case of [[hypnagogic hallucinations]], insight into the nature of the images remains intact. The false images can occur in any part of the visual field, and are rarely [[wikt:polymodal|polymodal]].<ref name=manford/>

===Delirium tremens===
{{main|Delerium tremens}}
One of the most enigmatic forms of visual hallucinations are the highly variable, possibly polymodal [[delirium tremens]]. Individuals suffering from delerium tremens may be agitated and confused, especially in the later stages of this disease. Insight is gradually reduced with the progression of this disorder. Sleep is disturbed and occurs for a shorter period of time, with [[REM overflow]].<ref name=manford/>

===Parkinson's disease and Lewy body dementia===
[[Parkinson's disease]] is linked with [[Dementia with Lewy bodies|Lewy body dementia]] for their similar hallucinatory symptoms. The symptoms strike during the evening in any part of the visual field and are rarely polymodal. The segue into hallucinations may start with illusions<ref>[http://www.nytimes.com/2006/02/14/health/14case.html?ex=1151121600&en=04560d31e7926bee&ei=5070 Mark Derr (2006)] Marilyn and Me, "The New York Times" Feb. 14th, 2006 </ref> where sensory perception is greatly distorted, but no novel sensory information is present. These typically last for several minutes, during which time the subject may be either conscious and normal or drowsy/inaccessible. Insight into these hallucinations is usually preserved and [[REM sleep]] is usually reduced. Parkinson's disease is usually associated with a degraded [[substantia nigra]] pars compacta, but recent evidence suggests that PD affects a number of sites in the brain. Some places of noted degradation include the median raphe nuclei, the noradrenergic parts of the locus coeruleus and the [[cholinergic]] neurons in the parabrachial and pedunculopontine nuclei of the [[tegmentum]].<ref name=manford/>

===Migraine coma===
This type of hallucination is usually experienced during the recovery from a comatose state. The migraine coma can last for up to two days and a state of depression is sometimes comorbid. The hallucinations occur during states of full consciousness and insight into the hallucinatory nature of the images is preserved. It has been noted that ataxic lesions accompany the migraine coma.<ref name=manford/>

===Charles Bonnet syndrome===
[[Charles Bonnet syndrome]] is the name given to visual hallucinations experienced by blind patients. The hallucinations can usually be dispersed by opening or closing the eyelids until the visual images disappear. The hallucinations usually occur during the morning or evening, but are not dependent on low light conditions. These prolonged hallucinations usually do not disturb the patients very much as they are aware that they are hallucinating.<ref name=manford/>

===Focal epilepsy===
The visual hallucinations from focal epilepsy are characterized by being brief, and stereotyped. They are usually localized to one part of the visual field and last only a few seconds. Other epileptic features may present themselves between visual episodes. Consciousness is usually impaired in some way, but nevertheless insight into the hallucination is preserved. Usually this type of focal epilepsy is caused by a lesion in the posterior temporoparietal.<ref name=manford/>

==Tactile hallucinations==

Can be associated with substance use, such as someone who feels bugs crawling on them after a prolonged period of [[cocaine]] use.

==Scientific explanations==
Various theories have been put forward to explain the occurrence of hallucinations. When [[psychodynamic]] ([[Freud]]ian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes, thoughts and wants. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the [[brain]]. With reference to mental illness, the function (or dysfunction) of the [[neurotransmitter]] [[dopamine]] is thought to be particularly important.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505794&dopt=Abstract Kapur S. (2003)] Psychosis as a state of aberrant salience: a framework linking biology, phenomenology, and pharmacology in schizophrenia. ''American Journal of Psychiatry'', 160(1), 13-23. </ref>
[[Psychology|Psychological]] research has argued that hallucinations may result from biases in what are known as [[metacognition|metacognitive]] abilities.<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2404293&dopt=Abstract Bentall RP. (1990)] The illusion of reality: a review and integration of psychological research on hallucinations. ''Psychological Bulletin'', 107(1), 82-95. </ref> These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, [[memory|memories]], [[belief]]s and [[thought]]s). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences. Projection of an internal state or a person's own reaction to another may arise in the form of hallucinations, especially auditory hallucinations. A few scientists have argued that such hallucinations may be the result of other conscious thoughts.

==Stages of a hallucination==
#Emergence of surprising or warded-off memory or [[fantasy (psychology)|fantasy]] images <ref name=horowitz>Horowitz, Mardi J., M.D. “Hallucinations: An Information Processing Approach." In Siegel, Ronald K., Ph. D. and L. J. West, eds. ''Hallucinations: Behavior, Experience and Theory'' (1975). New York: John Wiley.</ref>
#Frequent reality checks <ref name=horowitz />
#Last vestige of insight as hallucinations become “real” <ref name=horowitz />
#Fantasy and distortion elaborated upon and confused with actual perception <ref name=horowitz />
#Internal-external boundaries destroyed and possible pantheistic experience <ref name=horowitz />

==Diagnosis==

=== History and Symptoms ===
* Timing of hallucinations
* Suicidal/homicidal ideations
* Drug regimen
* Work with psychiatrist (if patient cannot communicate mental and physical history)

=== Laboratory Findings ===
* [[Complete blood count]] ([[CBC]])
* [[Glucose]]
* [[Calcium]]
* [[Albumin]]
* [[Alkaline phosphatase]]
* [[Blood urea nitrogen]] ([[BUN]])/[[creatinine]]
* [[Liver function tests]] ([[LFT]]s)
* [[Magnesium]]
* [[Phosphate]]
* [[Toxicology]] screen
* [[Urinalysis]]
* [[Pulse oximetry]]
* Drug levels
* [[Folate levels]]
* [[Vitamin B12]]
* [[Antinuclear antibody]] ([[ANA]])
* [[Heavy metal]] screen
* [[Ammonia]]

=== Electrolyte and Biomarker Studies ===

* Electrolytes

=== Chest X Ray ===
* [[Chest X-ray]] (infectious etiologies)

=== Other Imaging Findings ===
* [[Electroencephalogram]] ([[EEG]])

=== Other Diagnostic Studies ===
* [[Lumbar puncture]]

== Differential Diagnosis ==

In alphabetical order. <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016</ref> <ref>Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X</ref>

* Alcohol withdrawal
* [[Bipolar Disorder]]
* Central nervous system (CNS) infections
* [[Delirium]]
* [[Dementia]]
* [[Encephalitis]]
* Hallucinogenic syndromes (drug-induced)
* Heavy metal ingestion
* Lewy Body Dementia
* Mass lesions
* Occipital lobe injury
* Postpartum major depression
* [[Post Traumatic Stress Disorder|Post-Traumatic Stress Disorder]]
* Psychotic disorder
* Schizoaffective disorder
* [[Schizophrenia]]
* Schizophreniform disorder
* [[Seizures]]
* [[Systemic Lupus Erythematosus]]

{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Chemical / poisoning'''
|bgcolor="Beige"| [[Amanita muscaria]], [[Alcohol Withdrawal]], [[Carbon monoxide poisoning]], [[Alcoholism]], [[Mescaline]], [[Lysergic acid diethylamide]], [[Jenkem]], [[Nitrogen narcosis]], [[Laudanum]], [[Incapacitating agent]], [[Solanine]], [[Cocaine withdrawal ]], [[Bufotenin]], [[2C-T-2]], [[DESOXY]], [[3,4-Methylenedioxyamphetamine]], [[2C-E]], [[Dimethoxyamphetamine]], [[TOM (psychedelic)]], [[TOET (psychedelic)]], [[Substance D]], [[Ergot]], [[Henbane]], [[Phencyclidine]], [[Muscimol]], [[Datura tramonium]], [[Deadly nightshade]], [[Datura inoxia]], [[Datura wrightii]], [[Thujone]], [[5-Hydroxytryptophan]], [[2C-B]], [[2C-T-7]], [[Benzylpiperazine]], [[Candyflipping]], [[Mercury(II) chloride]], [[Ibotenic acid]], [[Khat]], [[PMA]], [[Amphetamine]], [[Psychedelic plants]], [[Psilocybin mushrooms]], [[Datura metel]], [[4-Acetoxy-DIPT]], [[Hallucinogen persisting perception disorder]], [[Formication]], [[Ergotism]], [[Ichthyoallyeinotoxism]], [[Abrin]], [[Delirium tremens]], [[Ascomycota]], [[Hawaiian baby woodrose]], [[Solanaceae]], [[Cocaine dependence]], [[5-F-AMT]], [[5-MeO-AMT]], [[Diisopropyltryptamine]], [[Dipropyltryptamine]]

|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Procainamide ]], [[Alatrofloxacin Injection ]], [[Lomotil]], [[Fluphenazine ]], [[Acyclovir ]], [[Cefaclor]], [[Morphine Oral ]], [[Pentamidine Isethionate Injection ]], [[Alfentanil Hydrochloride Injection ]], [[Atropine]], [[Aspirin]], [[Zolpidem ]], [[Zaleplon ]], [[Voriconazole ]], [[Venlafaxine]], [[Trovafloxacin ]], [[Trihexyphenidyl ]], [[Trifluoperazine Oral ]], [[Tolterodine ]], [[Atomoxetine]], [[Tolcapone ]], [[Thiothixene Oral ]], [[Thioridazine ]], [[Benztropine Mesylate Oral ]], [[Buprenorphine Sublingual and Buprenorphine and Naloxone Sublingual ]], [[Bupropion]], [[Butorphanol Injection ]], [[Chlorpromazine ]], [[Clarithromycin]], [[Clomipramine ]], [[Dexmethylphenidate]], [[Dextroamphetamine]], [[Dextromethorphan]], [[Dimenhydrinate]], [[Efavirenz ]], [[Entacapone ]], [[Eszopiclone ]], [[Fluconazole ]], [[Flurazepam ]], [[Galantamine ]], [[Gatifloxacin ]], [[Gatifloxacin Injection ]], [[Haloperidol Oral ]], [[Ifosfamide ]], [[Ketorolac]], [[Levodopa]], [[Lithium ]], [[Loxapine Oral ]], [[Mefloquine ]], [[Memantine]], [[Methylphenidate Transdermal ]], [[Mirtazapine]], [[Modafinil ]], [[Nabilone ]], [[Nalbuphine injection ]], [[Naltrexone ]], [[Orphenadrine ]], [[Oxybutynin ]], [[Pemoline ]], [[Pergolide ]], [[Perphenazine oral ]], [[Phenelzine ]], [[Pramipexole ]], [[Prochlorperazine ]], [[Procyclidine ]], [[Promethazine ]], [[Ropinirole ]], [[Scopolamine patch ]], [[Selegiline ]], [[Sertraline]], [[Sodium oxybate ]], [[Solifenacin ]], [[Sufentanil citrate injection ]], [[Procyclidine hydrochloride]], [[3-Quinuclidinyl benzilate]], [[Ketamine]], [[Nalmefene]], [[Dezocine]], [[Dimethyltryptamine]], [[Scopolamine]], [[Methamphetamine]], [[Morphine]], [[Alprazolam]], [[Beta-blockers]], [[Buspirone]], [[Hydroxyzine]], [[Imipramine]], [[Lorazepam]], [[Phentermine]], [[Temazepam]], [[Tizanidine]], [[Triazolam]], [[Ethchlorvynol withdrawal ]], [[Serotonin syndrome]], [[Psychotomimetic]], [[Benzodiazepine withdrawal syndrome]], [[Ziconotide]], [[Diphenhydramine]], [[Dizocilpine]], [[NMDA receptor antagonist]], [[Pentazocine]], [[Opioid]], [[Ketazocine]], [[Valproate semisodium]], [[Ephedrine]], [[SSRI discontinuation syndrome]], [[Baclofen]], [[Flucytosine]], [[Oxamniquine]], [[Aciclovir]], [[Nitrazepam]], [[Loprazolam]], [[Lormetazepam]], [[Biperiden]], [[Clozapine]], [[Dantrolene]], [[Tricyclic antidepressant]], [[Zopiclone]], [[Propylhexedrine]], [[Dissociative drugs]], [[Toxidrome]], [[Tifluadom]], [[Phenazocine]], [[Etoxadrol]], [[Cabergoline]]
|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Narcolepsy]], [[Encephalopathy]], [[Acute Disseminated Encephalomyelitis]], [[Migraine]], [[Dementia]], [[Delirium]], [[Complex partial seizure]], [[Arachnoid cyst]], [[Charles Bonnet syndrome]], [[Phantom eye syndrome]], [[Coats disease]], [[Entoptic phenomenon]], [[Closed-eye hallucination]], [[Cortical blindness]], [[High altitude cerebral edema]], [[Cerebral edema]], [[False memory]], [[Sleep deprivation]], [[Morvan's syndrome]], [[Fatal familial insomnia]], [[Endaural phenomena]], [[Parkinson plus syndrome]], [[Dementia with Lewy bodies]], [[Peduncular hallucinosis]], [[Temporal lobe epilepsy]], [[Aura (symptom)]], [[Parkinson's disease]], [[Traumatic brain injury]], [[Sensory deprivation]]

|-
|-bgcolor="LightSteelBlue"
| '''Nutritional / Metabolic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Opthalmologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Rheum / Immune / Allergy'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| No underlying causes
|-
|}

== Treatment ==
* Treat underlying etiologies

=== Acute Pharmacotherapies ===
* [[Antipsychotic drugs]]
* [[Benzodiazepine]]s

== See also ==
* [[Apparitional experience]]
* [[Closed-eye hallucination]]
* [[Delusion]]
* [[Dimethyltryptamine]]
* [[Dream]]
* [[Focal seizures]]
* [[Folie à deux]]
* Form constant
* [[Hallucinations in the sane]]
* [[Illusion]]
* Imaginary friend
* [[Phantom eye syndrome]]
* [[Psychedelics, dissociatives and deliriants|Hallucinogenic drug]]
* [[Psychosis]]
* [[Salvia divinorum]]
* Simulated reality

== References ==
{{reflist|2}}

{{SIB}}
{{WH}}
{{WS}}

[[Category:Signs and symptoms]]
[[Category:Psychiatry]]
[[Category:Mature chapter]]

[[cs:Halucinace]]
[[da:Hallucination]]
[[de:Halluzination]]
[[et:Hallutsinatsioon]]
[[es:Alucinación]]
[[fr:Hallucination]]
[[ga:Bréagchéadfa]]
[[it:Allucinazione]]
[[ku:Hallûsînasyon]]
[[he:הזיה]]
[[ka:ჰალუცინაცია]]
[[lb:Halluzinatioun]]
[[lt:Haliucinacija]]
[[hu:Hallucináció]]
[[mk:Халуцинација]]
[[nl:Hallucinatie]]
[[ja:幻覚]]
[[no:Hallusinasjon]]
[[pt:Alucinação]]
[[ru:Галлюцинация]]
[[simple:Hallucination]]
[[sk:Halucinácia]]
[[sl:Halucinacija]]
[[sr:Халуцинација]]
[[pl:Halucynacja]]
[[tr:Halüsinasyon]]
[[fi:Hallusinaatio]]
[[sv:Hallucination]]
[[ur:خطاۓ حس]]
[[zh:幻觉]]

Hallucination

2012-07-05T14:20:08Z

Aiham Jbeli: /* Differential Diagnosis */

Hallucination

2012-07-05T14:12:26Z

Aiham Jbeli: /* Differential Diagnosis */

Hallucination

2012-07-05T14:09:27Z

Aiham Jbeli: /* Differential Diagnosis */

Hallucination

2012-07-03T20:31:04Z

Aiham Jbeli: /* Differential Diagnosis */