Seizure overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Shakiba Hassanzadeh, MD[2]
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.
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Seizure from Other Diseases
Epidemiology and Demographics
It is estimated that 11% of the population experience a seizure in their life compared to the estimation of 3% for epilepsy.[2][3] In the US, seizure is estimated to account for 1 million or 1% of emergency department (ED) visits annually.[4]. The incidence of acute symptomatic seizures is estimated to be 39 cases per 100,000 individuals in the US. [5] Seizures are more common among males and the Black race.[4][5]
Risk Factors
Risk factors that can perticipate or provoke seizure may include: excessive sleep deprivation, alcohol use, illicit drug use, some medications that reduce the seizure threshold, toxins, homeostasis abnormality due to organ failure, metabolic abnormalities, and medical and surgical histories that may be important in assessing the patient’s risk for future seizures. [6][7][8]
Screening
Natural History, Complications, and Prognosis
The recurrence rate of seizure within 2 years is 35% to 40% in patients with a first-time unprovoked seizure.[9] Status epilepticus occurs in about 6%-7% of the patients with seizure in the emergency department (ED).[10][11][12] The overall mortality rate of status epilepticus is approximately 22% (3% in pediatric patients to 26% in adults).[13] Simple febrile seizures are considered normal in childhood and the prognosis is generally excellent. The recurrence rate is about 12% in children that have their first febrile seizure in infancy and about 50% in those who have their first febrile seizure later.[14][15]
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).[16]
CT
Computed tomography scan (CT scan) in the emergency department is helpful in ruling out hemorrhage or other lesions.[17]
MRI
MRI scan (preferably 3 tesla) should be performed in order to detect epileptogenic lesions.[17]
MRI is more sensitive in detecting some findings compared to CT scan.[18]
Other Imaging Findings
3-T MRI may be helpful in patients with epilepsy and negative 1.5-T MRI.[19][20]
Other Diagnostic Studies
EEG with sleep deprivation is helpful when standard EEG does not detect any epileptiform changes.[21]
Treatment
Medical Therapy
In the acute setting, seizures are initially treated with benzodiazepines (lorazepam or midazolam), followed by phenytoin or phenobarbital.[22]
Antiepileptic drugs (AEDs) are commonly used in treating focal and generalized epilepsies.[16]
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.[16]
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
The national economical impact of epilepsy is estimated at $9.6 billion per year in the United States.[23]
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.[16]
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.
- ↑ Bethune P, Gordon K, Dooley J, Camfield C, Camfield P (1993). "Which child will have a febrile seizure?". Am J Dis Child. 147 (1): 35–9. doi:10.1001/archpedi.1993.02160250037013. PMID 7678187.
- ↑ Hauser WA, Annegers JF, Rocca WA (1996). "Descriptive epidemiology of epilepsy: contributions of population-based studies from Rochester, Minnesota". Mayo Clin Proc. 71 (6): 576–86. doi:10.4065/71.6.576. PMID 8642887.
- ↑ 4.0 4.1 Pallin DJ, Goldstein JN, Moussally JS, Pelletier AJ, Green AR, Camargo CA (2008). "Seizure visits in US emergency departments: epidemiology and potential disparities in care". Int J Emerg Med. 1 (2): 97–105. doi:10.1007/s12245-008-0024-4. PMC 2657249. PMID 19384659.
- ↑ 5.0 5.1 Annegers JF, Hauser WA, Lee JR, Rocca WA (1995). "Incidence of acute symptomatic seizures in Rochester, Minnesota, 1935-1984". Epilepsia. 36 (4): 327–33. doi:10.1111/j.1528-1157.1995.tb01005.x. PMID 7607110.
- ↑ Pohlmann-Eden, Bernd; Legg, Karen T. (2013). "Treatment of first seizure in adults: A comprehensive approach integrating 10 key principles". Epileptology. Elsevier BV. 1 (1): 61–67. doi:10.1016/j.epilep.2013.01.005. ISSN 2212-8220.
- ↑ Delanty N, Vaughan CJ, French JA (1998). "Medical causes of seizures". Lancet. 352 (9125): 383–90. doi:10.1016/S0140-6736(98)02158-8. PMID 9717943.
- ↑ Gavvala JR, Schuele SU (2016). "New-Onset Seizure in Adults and Adolescents: A Review". JAMA. 316 (24): 2657–2668. doi:10.1001/jama.2016.18625. PMID 28027373.
- ↑ Berg AT, Testa FM, Levy SR, Shinnar S (1996). "The epidemiology of epilepsy. Past, present, and future". Neurol Clin. 14 (2): 383–98. doi:10.1016/s0733-8619(05)70263-2. PMID 8827178.
- ↑ Huff JS, Morris DL, Kothari RU, Gibbs MA, Emergency Medicine Seizure Study Group (2001). "Emergency department management of patients with seizures: a multicenter study". Acad Emerg Med. 8 (6): 622–8. doi:10.1111/j.1553-2712.2001.tb00175.x. PMID 11388937.
- ↑ Krumholz A, Grufferman S, Orr ST, Stern BJ (1989). "Seizures and seizure care in an emergency department". Epilepsia. 30 (2): 175–81. doi:10.1111/j.1528-1157.1989.tb05451.x. PMID 2924743.
- ↑ Brinar V, Bozicević D, Zurak N, Gubarev N, Djaković V (1991). "Epileptic seizures as a symptom of various neurological diseases". Neurol Croat. 40 (2): 93–101. PMID 1883923.
- ↑ DeLorenzo RJ, Hauser WA, Towne AR, Boggs JG, Pellock JM, Penberthy L; et al. (1996). "A prospective, population-based epidemiologic study of status epilepticus in Richmond, Virginia". Neurology. 46 (4): 1029–35. doi:10.1212/wnl.46.4.1029. PMID 8780085.
- ↑ Kenney RD, Taylor JA (1992). "Absence of serum chemistry abnormalities in pediatric patients presenting with seizures". Pediatr Emerg Care. 8 (2): 65–6. doi:10.1097/00006565-199204000-00001. PMID 1603702.
- ↑ Walton DM, Thomas DC, Aly HZ, Short BL (2000). "Morbid hypocalcemia associated with phosphate enema in a six-week-old infant". Pediatrics. 106 (3): E37. doi:10.1542/peds.106.3.e37. PMID 10969121.
- ↑ 16.0 16.1 16.2 16.3 Johnson EL (2019). "Seizures and Epilepsy". Med Clin North Am. 103 (2): 309–324. doi:10.1016/j.mcna.2018.10.002. PMID 30704683.
- ↑ 17.0 17.1 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.
- ↑ Radue EW, Scollo-Lavizzari G (1994). "Computed tomography and magnetic resonance imaging in epileptic seizures". Eur Neurol. 34 Suppl 1: 55–7. doi:10.1159/000119510. PMID 8001611.
- ↑ Ladino LD, Balaguera P, Rascovsky S, Delgado J, Llano J, Hernández-Ronquillo L; et al. (2016). "Clinical Benefit of 3 Tesla Magnetic Resonance Imaging Rescanning in Patients With Focal Epilepsy and Negative 1.5 Tesla Magnetic Resonance Imaging". Rev Invest Clin. 68 (3): 112–8. PMID 27408997.
- ↑ Knake S, Triantafyllou C, Wald LL, Wiggins G, Kirk GP, Larsson PG; et al. (2005). "3T phased array MRI improves the presurgical evaluation in focal epilepsies: a prospective study". Neurology. 65 (7): 1026–31. doi:10.1212/01.wnl.0000179355.04481.3c. PMID 16217054.
- ↑ 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.
- ↑ Yoon D, Frick KD, Carr DA, Austin JK (2009). "Economic impact of epilepsy in the United States". Epilepsia. 50 (10): 2186–91. doi:10.1111/j.1528-1167.2009.02159.x. PMID 19508694.