Dizziness pathophysiology
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Fatimo Biobaku M.B.B.S [2] Norina Usman, M.B.B.S[3]
Overview
The pathophysiology of dizziness depends on the etiological subtype including orthostatic hypotension, benign paroxysmal positional vertigo, Meniere's disease, Parkinson's disease, hyperventilation syndrome, peripheral neuropathy, and vestibular migraine.
Pathophysiology
The pathophysiology of dizziness depends on the etiological subtype, and area of pathology involved[1][2][3][4][5].
| Cause | Pathophysiology | Category of dizziness |
|---|---|---|
| Orthostatic hypotension | It is a drop in blood pressure on changing the position or can be due to the side effect of the medicine | Presyncope |
| Benign paroxysmal positional vertigo | The semicircular canal contains loose otolith, which gives a false sense of motion. | Vertigo |
| Meniere's disease | Excessive endolymphatic fluid in the inner ear | Vertigo |
| Hyperventilation syndrome | Hyperventilation leads to respiratory alkalosis | Lightheadedness |
| Peripheral neuropathy | Decrease tactile sensation may cause patients to lack the feeling of feet to be touched to the ground leading to falls and imbalance. | Disequilibrium |
| Parkinson disease | Gait dysfunction cause falls and imbalance | Disequilibrium |
| Vestibular migraine | Uncertain | Vertigo |
The pathophysiology of dizziness can be explained according to one of its classification systems based on central and peripheral, although there is often overlap between the two. [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16]
-Peripheral:
-Vestibular dysfunction which involves vestibular neuritis/neuronitis can occur as a single attack or multiple attacks. When there is concurrent hearing loss, it is termed at neurolabyrinthitis. The hair cell bodies are said to be involved that help in transducing movement.
-Bilateral vestibular hypofunction (partial or complete): usually by toxic (gentamicin) or immune mechanisms.
-Autoimmune: rapidly progressive and bilateral. Like any other autoimmune disease, there is a female preponderance in the reproductive age group.
-Systemic or central vestibular dysfunction: involves the vestibular nuclei.
-Meniere's disease which is the tetrad of vertigo, tinnitus, sensorineural hearing loss and aural fullness. The exact etiology is unknown although viral causes have been implicated. The symptoms arise because of endolymphatic pressure change.
-BPPV: The posterior semicircular canal is the most commonly involved space. The most likely etiology is dislodgment of an otoconia.
-Perilymphatic fistula: Fistula is an abnormal communication between two structures; in this case between the membranous labyrinth and middle ear. Can be due to causes like barotrauma (implosive) or increased intracranial pressure (explosive). Acquired fistulas may result from chronic ear surgery.
-Central causes can be further divided based on issues with circulation and other miscellaneous causes as follows
-Circulation related causes:
-Cardiogenic, such as: infarction, occlusion. Conditions that compromise blood supply to the brain for example; cardiac failure, aortic stenosis, arrhythmia, etc can causes dizziness. -Occlusion of the carotid artery: usually not a cause for dizziness unless both anterior and posterior circulations are compromised. -Cerebrovascular accidents which involve both large and small vessel ischemia or stroke. -Large vessel syndromes: -Veretebrobasilar insufficiency -Vertebral artery thrombosis -Basilar artery thrombosis -Small vessel syndromes: -Wallenberg(Lateral medullary) syndrome: accompanying features are Horner's syndrome, dysarthria, hemiataxia -Anterior inferior cerebellar artery syndrome- labyrinthine artery ischemia causing unilateral deafness, ataxia and facial weakness -Labyrythnine artery syndrome -Other causes:
-Acoustic neuroma: benign tumor of the eighth cranial nerve causing hearing loss that is high frequency and sensorineural. Unilateral tinnitus, dizziness is seen in <20% of the population, upto 70% may have imbalance. -Cervicogenic -Metabolic dizziness: comprising of low blood sugar (hypoglycemia) and accompanied by other symptoms such as tremors, palpitations, sweating, etc. Thyroid conditions (both hypothyroidism and hyperthyroidism) as well as low blood magnesium levels can also cause dizziness. -Migraine- Neuhauser and his colleagues formed the following list of criteria for migrainous vertigo: -recurrent attacks of vertigo -headache meeting criteria of International Headache Society -At least one of the following symptoms during at least two of these attacks: migraine headache, intolerance to light, intolerance to sound, presence of an aura, absence of other causes -Pathophysiologic- integration of the visual, vestibular, autonomic, and proprioceptive systems. Not necessarily pathologic, example: feeling of falling while standing on the ledge of a building that is very tall. -Anxiety and related disorders: may or may not be related to hyperventilation. Possible exacerbation by a vestibular syndrome. Phobic dizziness/ postural vertigo is the fear of falling without gait instability. Usually associated with panic disorder or agoraphobia. -Vestibular epilepsy: episode of dizziness or vertigo accompanied by a seizure or preceding the aura.
References
- ↑ Hanley K, O'Dowd T, Considine N (2001). "A systematic review of vertigo in primary care". Br J Gen Pract. 51 (469): 666–71. PMC 1314080. PMID 11510399.
- ↑ Ebersbach G, Sojer M, Valldeoriola F, Wissel J, Müller J, Tolosa E; et al. (1999). "Comparative analysis of gait in Parkinson's disease, cerebellar ataxia and subcortical arteriosclerotic encephalopathy". Brain. 122 ( Pt 7): 1349–55. doi:10.1093/brain/122.7.1349. PMID 10388800.
- ↑ Kroenke K, Lucas CA, Rosenberg ML, Scherokman B, Herbers JE, Wehrle PA; et al. (1992). "Causes of persistent dizziness. A prospective study of 100 patients in ambulatory care". Ann Intern Med. 117 (11): 898–904. doi:10.7326/0003-4819-117-11-898. PMID 1443950.
- ↑ Hoffman RM, Einstadter D, Kroenke K (1999). "Evaluating dizziness". Am J Med. 107 (5): 468–78. doi:10.1016/s0002-9343(99)00260-0. PMID 10569302.
- ↑ Kentala E, Rauch SD (2003). "A practical assessment algorithm for diagnosis of dizziness". Otolaryngol Head Neck Surg. 128 (1): 54–9. doi:10.1067/mhn.2003.47. PMID 12574760.
- ↑ Hughes GB, Kinney SE, Hamid MA, Barna BP, Calabrese LH (August 1985). "Autoimmune vestibular dysfunction: preliminary report". Laryngoscope. 95 (8): 893–7. doi:10.1288/00005537-198508000-00001. PMID 3875013.
- ↑ Goodhill V (1981). "Ben H. Senturia lecture. Leaking labyrinth lesions, deafness, tinnitus and dizziness". Ann Otol Rhinol Laryngol. 90 (2 Pt 1): 99–106. doi:10.1177/000348948109000201. PMID 7224522.
- ↑ Oas JG (October 2001). "Benign paroxysmal positional vertigo: a clinician's perspective". Ann N Y Acad Sci. 942: 201–9. doi:10.1111/j.1749-6632.2001.tb03746.x. PMID 11710462.
- ↑ Pearson BW, Brackmann DE (October 1985). "Committee on Hearing and Equilibrium guidelines for reporting treatment results in Meniere's disease". Otolaryngol Head Neck Surg. 93 (5): 579–81. doi:10.1177/019459988509300501. PMID 2932668.
- ↑ Minor LB, Solomon D, Zinreich JS, Zee DS (March 1998). "Sound- and/or pressure-induced vertigo due to bone dehiscence of the superior semicircular canal". Arch Otolaryngol Head Neck Surg. 124 (3): 249–58. doi:10.1001/archotol.124.3.249. PMID 9525507.
- ↑ Neuhauser H, Leopold M, von Brevern M, Arnold G, Lempert T (February 2001). "The interrelations of migraine, vertigo, and migrainous vertigo". Neurology. 56 (4): 436–41. doi:10.1212/wnl.56.4.436. PMID 11222783.
- ↑ Xie S, Guo J, Wu Z, Qiang D, Huang J, Zheng Y, Yao Q, Chen S, Tian D (December 2013). "Vibration-induced nystagmus in patients with unilateral peripheral vestibular disorders". Indian J Otolaryngol Head Neck Surg. 65 (4): 333–8. doi:10.1007/s12070-013-0638-6. PMC 3851498. PMID 24427594.
- ↑ Wrisley DM, Sparto PJ, Whitney SL, Furman JM (December 2000). "Cervicogenic dizziness: a review of diagnosis and treatment". J Orthop Sports Phys Ther. 30 (12): 755–66. doi:10.2519/jospt.2000.30.12.755. PMID 11153554.
- ↑ Fife TD, Tusa RJ, Furman JM, Zee DS, Frohman E, Baloh RW, Hain T, Goebel J, Demer J, Eviatar L (November 2000). "Assessment: vestibular testing techniques in adults and children: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology". Neurology. 55 (10): 1431–41. doi:10.1212/wnl.55.10.1431. PMID 11094095.
- ↑ Epley JM (1980). "New dimensions of benign paroxysmal positional vertigo". Otolaryngol Head Neck Surg (1979). 88 (5): 599–605. doi:10.1177/019459988008800514. PMID 7443266.
- ↑ White J, Savvides P, Cherian N, Oas J (July 2005). "Canalith repositioning for benign paroxysmal positional vertigo". Otol Neurotol. 26 (4): 704–10. doi:10.1097/01.mao.0000178128.66482.7e. PMID 16015173.