Seizure overview
|
Seizure Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Seizure overview On the Web |
|
American Roentgen Ray Society Images of Seizure overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
A seizure is a temporary abnormal electro-physiologic phenomenon of the brain, resulting in abnormal synchronization of electrical neuronal activity. It can manifest as an alteration in mental state, tonic or clonic movements, convulsions, and various other psychic symptoms (such as déjà vu or jamais vu). It is caused by a temporary abnormal electrical activity of a group of brain cells. The medical syndrome of recurrent, unprovoked seizures is termed epilepsy, but some seizures may occur in people who do not have epilepsy.
The treatment of epilepsy is a subspecialty of neurology; the study of seizures is part of neuroscience.
Classification
The numerous epileptic seizure types are most commonly defined and grouped according to a scheme proposed by the International League Against Epilepsy (ILAE) in 1981.[1] Distinguishing between seizure types is important since different types of seizure may have different causes, prognosis and treatments.
Epidemiology and Demographics
About 4% of people will have an unprovoked seizure by the age of 80 and yet the chance of experiencing a second seizure is between 30% and 50%.
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
Electroencephalogram
EEG should be performed as soon as possible and can detect: focal sharp waves or spikes (focal epilepsy) and bilateral/generalized epileptiform activity (generalized epilepsy).[2]
CT
Computed tomography scan (CT scan) in the emergency department is helpful in ruling out hemorrhage or other lesions.[3]
MRI
MRI scan (preferably 3 tesla) should be performed in order to detect epileptogenic lesions.[3]
Other Imaging Findings
Other Diagnostic Studies
EEG with sleep deprivation is helpful when standard EEG does not detect any epileptiform changes.[4]
Treatment
Medical Therapy
In the acute setting, seizures are initially treated with benzodiazepines (lorazepam or midazolam), followed by phenytoin or phenobarbital.[5]
Antiepileptic drugs (AEDs) are commonly used in treating focal and generalized epilepsies.[2]
Surgery
Surgery may be helpful in patients with focal epilepsy if there is no seizure control after two or more antiepileptic drugs (AEDs).
Laser interstitial thermal ablation and neurostimulation may be helpful as alternative therapies to surgery in some patients.[2]
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Further studies are required for producing new drugs with novel mechanisms of action and finding new treatments by increasing the knowledge of the mechanisms of dietary therapy in epilepsy and the role that neurosteroid hormones have in exacerbating epilepsy.[2]
References
- ↑ "Proposal for revised clinical and electroencephalographic classification of epileptic seizures. From the Commission on Classification and Terminology of the International League Against Epilepsy". Epilepsia. 22 (4): 489–501. 1981. PMID 6790275.
- ↑ 2.0 2.1 2.2 2.3 Johnson EL (2019). "Seizures and Epilepsy". Med Clin North Am. 103 (2): 309–324. doi:10.1016/j.mcna.2018.10.002. PMID 30704683.
- ↑ 3.0 3.1 Bank AM, Bazil CW (2019). "Emergency Management of Epilepsy and Seizures". Semin Neurol. 39 (1): 73–81. doi:10.1055/s-0038-1677008. PMID 30743294.
- ↑ Schreiner A, Pohlmann-Eden B (2003). "Value of the early electroencephalogram after a first unprovoked seizure". Clin Electroencephalogr. 34 (3): 140–4. doi:10.1177/155005940303400307. PMID 14521275.
- ↑ Glauser T, Shinnar S, Gloss D, Alldredge B, Arya R, Bainbridge J; et al. (2016). "Evidence-Based Guideline: Treatment of Convulsive Status Epilepticus in Children and Adults: Report of the Guideline Committee of the American Epilepsy Society". Epilepsy Curr. 16 (1): 48–61. doi:10.5698/1535-7597-16.1.48. PMC 4749120. PMID 26900382.