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| __NOTOC__
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| {{Epilepsy}} | | {{Epilepsy}} |
| {{CMG}} {{AE}} {{VVS}} | | {{CMG}}; {{AE}} {{Fs}} |
| ==Classification==
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| Epilepsies are classified five ways:
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| # By their first cause (or [[etiology]]).
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| # By the observable manifestations of the seizures, known as semiology.
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| # By the location in the brain where the seizures originate.
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| # As a part of discrete, identifiable medical [[syndrome]]s.
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| # By the event that triggers the seizures, as in primary reading epilepsy.
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| In 1981, the International League Against Epilepsy (ILAE) proposed a classification scheme for individual seizures that remains in common use.<ref name="ILEA1981">{{cite journal
| | == Overview == |
| | author =
| | Epilepsy may be classified according to type of onset into [[Focal Epilepsy|focal]], [[Generalised epilepsy|generalized]] and unknown. Each of these groups can be further divided into motor and non-motor subgroups. |
| | title = Proposal for revised clinical and electroencephalographic classification of epileptic seizures. From the Commission on Classification and Terminology of the International League Against Epilepsy.
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| | journal = Epilepsia
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| | volume = 22
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| | issue = 4
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| | pages = 489-501
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| | year = 1981
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| | id = PMID 6790275}}</ref> This classification is based on observation (clinical and EEG) rather than the underlying pathophysiology or anatomy and is outlined later on in this article. In 1989, the ILAE proposed a classification scheme for epilepsies and epileptic syndromes.<ref name="ILEA1989">{{cite journal
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| | author =
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| | title = Proposal for revised classification of epilepsies and epileptic syndromes. Commission on Classification and Terminology of the International League Against Epilepsy.
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| | journal = Epilepsia
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| | volume = 30
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| | issue = 4
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| | pages = 389-99
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| | year =1989
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| | id = PMID 2502382}}</ref> This can be broadly described as a two-axis scheme having the cause on one axis and the extent of localisation within the brain on the other. Since 1997, the ILAE have been working on a new scheme that has five axes: ictal phenomenon, seizure type, syndrome, etiology and impairment.<ref name="ILAE">{{cite web
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| | url = http://www.ilae-epilepsy.org/Visitors/Centre/ctf/overview.cfm
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| | title = A Proposed Diagnostic Scheme For People With Epileptic Seizures And With Epilepsy: Report Of The Ilae Task Force On Classification And Terminology
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| | accessdate = 2006-07-18
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| | author = Jerome Engel
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| | publisher = ILAE
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| }}</ref>
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| === Seizure types === | | ==Classification== |
| {{Main|Seizure types}} | | * Epilepsy may be classified according to type of onset into:<ref name="FisherCross2017">{{cite journal|last1=Fisher|first1=Robert S.|last2=Cross|first2=J. Helen|last3=D'Souza|first3=Carol|last4=French|first4=Jacqueline A.|last5=Haut|first5=Sheryl R.|last6=Higurashi|first6=Norimichi|last7=Hirsch|first7=Edouard|last8=Jansen|first8=Floor E.|last9=Lagae|first9=Lieven|last10=Moshé|first10=Solomon L.|last11=Peltola|first11=Jukka|last12=Roulet Perez|first12=Eliane|last13=Scheffer|first13=Ingrid E.|last14=Schulze-Bonhage|first14=Andreas|last15=Somerville|first15=Ernest|last16=Sperling|first16=Michael|last17=Yacubian|first17=Elza Márcia|last18=Zuberi|first18=Sameer M.|title=Instruction manual for the ILAE 2017 operational classification of seizure types|journal=Epilepsia|volume=58|issue=4|year=2017|pages=531–542|issn=00139580|doi=10.1111/epi.13671}}</ref> |
| Seizure types are organized firstly according to whether the source of the seizure within the brain is localized ([[Focal seizures|''partial'' or ''focal'']] onset seizures) or distributed (''generalized'' seizures). Partial seizures are further divided on the extent to which consciousness is affected. If it is unaffected, then it is a ''[[Simple partial seizure|simple partial]]'' seizure; otherwise it is a ''[[Complex partial seizure|complex partial]]'' (psychomotor) seizure. A partial seizure may spread within the brain - a process known as ''secondary generalization''. Generalized seizures are divided according to the effect on the body but all involve loss of consciousness. These include [[Absence seizure|absence]] (petit mal), [[Myoclonus|myoclonic]], [[Clonus|clonic]], tonic, [[Tonic-clonic seizure|tonic-clonic]] (grand mal) and [[Atonic seizure|atonic]] seizures.
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| === Seizure Syndromes ===
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| There are many different epilepsy syndromes, each presenting with its own unique combination of seizure type, typical age of onset, EEG findings, treatment, and prognosis. Below are some common seizure syndromes:
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| {| style="border: 0px; font-size: 90%; margin: 3px;" align=center
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| |+ '''Seizure Syndromes '''
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| ! style="background: #4479BA; color:#FFF;" | Type of seizure
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| ! style="background: #4479BA; color:#FFF;" | Typical age of onset
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| ! style="background: #4479BA; color:#FFF;" | Description
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| ! style="background: #4479BA; color:#FFF;" | EEG findings
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| ! style="background: #4479BA; color:#FFF;" | Prognosis
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| ! style="background: #4479BA; color:#FFF;" | Treatment
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| | style="padding: 5px 5px; background: #F5F5F5;" | ''[[Infantile spasms]] ([[West syndrome]])''
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| | style="padding: 5px 5px; background: #F5F5F5;" | Affects infants (30 days to 1 year of life)
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| * Characterized by sudden flexor and extensor spasms of head, trunk, and extremities<BR>
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| * Associated with brain development abnormalities, [[tuberous sclerosis]] and perinatal insults to the brain
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| | style="padding: 5px 5px; background: #F5F5F5;" | [[Hypsarrhythmia]], or a high-voltage slow wave with multifocal spikes
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| [[image:Spike-waves.png|right|thumb|Generalized 3 Hz spike and wave discharges in EEG]]
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| | style="padding: 5px 5px; background: #F5F5F5;" | Poor prognosis (more than two-thirds will have severe deficits)
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| * First line treatment for these patients is [[adrenocorticotropic hormone]] ([[ACTH]] or [[corticotropin]])<BR>
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| * [[Vigabatrin]] is particularly effective when tuberous sclerosis is the cause of seizures
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| |}
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| | | {{Family tree/start}} |
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| | {{Family tree | | | | | | | | | | | A01 | | | | | | | | | | A01=Type of onset}} |
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| | {{Family tree | | | |,|-|-|-|-|-|-|-|+|-|-|-|-|-|-|-|-|-|.| | | | | }} |
| * ''[[Childhood absence epilepsy]]''
| | {{Family tree | | | B01 |~| B00 |~| B02 | | | | | | | | B03 | | | | B01=Focal|B00=secondary generalized|B02=Generalized|B03=Unknown}} |
| Affects children between the ages of 4 and 12 years of age.
| | {{Family tree | |,|-|^|-|.| | | |,|-|^|-|.| | | |,|-|-|-|+|-|-|-|.|}} |
| These patients have recurrent absence seizures that can occur hundreds of times a day.
| | {{Family tree | C01 | | C02 | | C03 | | C04 | | C05 | | C06 | | C07 | | |C01=[[Motor]]|C02=Non-motor|C03=Motor|C04=Non-motor|C05=Motor|C06=Non-motor|C07=Unclassified }} |
| On EEG, one finds the stereotyped generalized 3 Hz spike and wave discharges.
| | {{Family tree | |!| | | |!| | | |!| | | |!| | | |!| | | |!| | | | | | | | }} |
| A subset of these patients will also develop generalized tonic-clonic seizures.
| | {{Family tree |boxstyle=text-align: left; | D01 | | D02 | | D03 | | D04 | | D05 | | D06 | | | | | | D01=•[[Automatisms]]<br>• [[Atonic]]<br>• [[Clonic]]<br>• Epileptic [[spasm]]<br>• [[Hyperkinetic]]<br>• [[Myoclonic]]<br>• [[Tonic]]|D02=• [[Autonomic]]<br>• Behavior arrest<br>• Cognitive<br>• Emotional<br>• [[Sensory]]<br>|D03=• Tonic-clonic<br>• Clonic<br>• Tonic<br>• Myoclonic<br>• [[Myoclonic-tonic-clonic]]<br>• [[Myoclonic-atonic]]<br>• [[Atonia]]<br>• Epileptic [[spasm]]<br>|D04=• Typical<br>• Atypical<br>• [[Myoclonic]]<br>• [[Eyelid]] [[myocloni]]<br>|D05=• [[Tonic-clonic]]<br>• Epileptic<br>• [[Spasm]]<br>|D06=• Behavior arrest<br>|}} |
| This condition carries a fairly good prognosis in that these children do not usually show cognitive decline or neurological deficits.
| | {{Family tree | | | | | | | | | | | | | | | | | | | | }} |
| First line treatment for pure absence seizures is [[ethosuximide]]. If patients do not respond or have mixed seizures along with their absence seizures, then [[valproic acid]] can be used.
| | {{Family tree | | | | | | | | | | | | | | | | | | | | }} |
| | | {{Family tree/end}} |
| * ''[[Dravet's syndrome]]'' Severe myoclonic epilepsy of infancy (SMEI).
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| This very rare syndrome is delimitated from benign myoclonic epilepsy by its severity and must be differentiated from the Lennox-Gastaut syndrome and Doose’s myoclonic-astatic epilepsy.
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| Onset in first year of life. Symptoms peak at about 5 months of age with febrile hemiclonic or generalized status epilepticus. Boys twice as often affected as girls. Prognosis is poor. Most cases are sporadic. Family history of epilepsy and febrile convulsions is present in around 25 percent of the cases, but familial cases are exceptionnal. From: [http://www.dravet.com www.dravet.com]
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| * ''[[Benign focal epilepsies of childhood]]''
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| The most common syndromes comprising the benign focal epilepsies of childhood include Benign Childhood Epilepsy with Centro-Temporal Spikes (or benign rolandic epilepsy), and Benign Childhood Epilepsy with Occipital Paroxysms.
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| Benign rolandic epilepsy begins in children between the ages of 3 and 16 years. Apart from their seizure disorder, these patients are otherwise normal.
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| Seizures typically occur at night, and are brief, focal motor events affecting facial and pharyngeal muscles, though may be generalized convulsions as well.
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| Focal seizures may be less frequently reported than more obvious generalized seizures. Between seizures, patients have a stereotyped EEG pattern that includes di- or triphasic sharp waves over the central-midtemporal (Rolandic) regions.
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| Prognosis is quite good overall with seizures disappearing by adolescence.
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| There is no consensus on the first line treatment, however most cases respond well to most [[anticonvulsant]]s.
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| * ''[[Juvenile myoclonic epilepsy]]'' (JME)
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| begins in patients aged 8 to 20 years. These patients have normal IQ and are otherwise neurologically intact. JME is thought to be genetic, though that is not to say that JME will show in immediate family members. The seizures are morning myoclonic jerks often with generalized tonic-clonic seizures that occur just after waking. 'Petit mal' or absence seizures are less common in cases of JME, but are known to occur more often in young girls.
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| EEG readings reveal generalized spikes with 4-6 Hz spike wave discharges and multiple spike discharges. Interestingly, these patients are often first diagnosed when they have their first generalized tonic-clonic seizure later in life when they experience sleep deprivation (e.g., freshman year in college after staying up late to study for exams). Alcohol is a major contributing factor and those with severe JME should monitor their intake of units.
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| [[Valproic acid]] is the first line treatment, whereas carbamazepine can actually worsen symptoms. This condition is lifelong, thus patients must be taught appropriate sleep hygiene to prevent generalized tonic-clonic seizures. The severity of JME varies from person to person - some will experience full blown tonic-clonic seizures regularly, others will suffer only under sufficient stress from lack of sleep and intoxication. | |
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| * ''[[Temporal lobe epilepsy]]'' is the most common epilepsy of adults. In most cases, the epileptogenic region is found in the medial temporal structures (e.g., the hippocampus, amygdala, and parahippocampal gyrus). Seizures begin in late childhood and adolescence. There is an association with febrile seizures in childhood, and some studies have shown herpes simplex virus (HSV) DNA in these regions, suggesting that perhaps this epilepsy has an infectious etiology.
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| Most of these patients have complex partial seizures sometimes preceded by an [[Aura (symptom)|aura]], and some TLE patients also suffer from secondary generalised [[tonic-clonic seizures]].
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| If the patient does not respond sufficiently to medical treatment, surgery may be considered.
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| * ''[[Fetal alcohol syndrome]]''
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| (FAS) is caused by prenatal [[alcohol]] exposure and results in [[central nervous system]] (CNS) damage. Seizure disorders due to prenatal alcohol exposure are one of several possible criteria for diagnosing FASD; however, any seizure disorder due to postnatal insult does not qualify as a diagnostic criterion for FASD.<ref>Astley, S.J. (2004). ''Diagnostic Guide for Fetal Alcohol Spectrum Disorders: The 4-Digit Diagnostic Code''. Seattle: University of Washington. Can be downloaded at http://depts.washington.edu/fasdpn.</ref>
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| * ''[[Frontal lobe epilepsy]]''
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| * ''[[Lennox-Gastaut syndrome]]''
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| * ''Occipital lobe epilepsy''
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| ==References== | | ==References== |
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| {{WH}} | | {{WH}} |
| {{WS}} | | {{WS}} |
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| [[Category:Needs overview]] | | [[Category:Needs overview]] |
| [[Category:Neurological disorders]] | | [[Category:Neurological disorders]] |
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| [[Category:Pediatrics]] | | [[Category:Pediatrics]] |
| [[Category:Emergency medicine]] | | [[Category:Emergency medicine]] |
| [[Category:Primary care]]
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