EpilepsyGene

About epilepsy	Epilepsy classification	Seizure type	Phenotype & abbreviation

What is epilepsy?

• Epilepsy is a group of neurological disorders characterized by recurrent epileptic seizures [1]

• Recurrent epileptic seizures (two or more) occurring >24 h apart. [2]

• Or one unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years. [3]

• Or diagnosis of an epilepsy syndrome. [3]

• Unprovoked by any immediate identified cause. [2]

• It affects 3.5-6.5 per 1000 children [4] and 10.8 per 1000 elderly people [5].

What is epileptic seizure?

• An epileptic seizure is a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". [1]

• Seizures can be classified into two types: partial seizure and generalized seizure

• An electroencephalography (EEG) will be useful to determine the seizure type.

What is non-epileptic seizure?

• A non-epileptic seizure is a paroxysmal event that is similar to an epileptic seizure. [6]

• Do not involve abnormal, rhythmic discharges of cortical neurons. [6]

• Caused by physiological or psychological conditions.

• For example:

Seizures are caused by conditions such as low blood sugar (hypoglycaemia) or a change to the way the heart is working.

Some very young children have 'febrile convulsions' (jerking movements) when they have a high temperature. [7]

Comorbidity with other disorders?

• Autism spectrum disorder (ASD) may occur in 15-35% of children with epilepsy. [8]

• Epilepsy is estimated to affect 7-46% of patients with ASD. [8]

• All seizure types have been reported in ASD, but focal epilepsy seems to be prevalent. [8-9]

• Children and adolescents with epilepsy tend to show an increase risk of attention deficit hyperactivity disorder (ADHD), which is present in 12-70%. [8,10-12]

• The prevalence of epilepsy in patients with autism and mental retardation (MR) is up to 40 percent. [13]

• Individuals with epilepsy are at increased risk of having schizophrenia. [14]

References:

[1] Epidemiology, C.o. and Prognosis, I.L.A.E. (1993) Guidelines for epidemiologic studies on epilepsy. Epilepsia, 34.

[2] Commission on Epidemiology and Prognosis, International League Against Epilepsy. Guidelines for epidemiologic studies on epilepsy[J]. Epilepsia, 1993, 34(4).

[3] Fisher R S, Acevedo C, Arzimanoglou A, et al. ILAE Official Report: A practical clinical definition of epilepsy[J]. Epilepsia, 2014, 55(4): 475-482.

[4] Lo-Castro A, Curatolo P. Epilepsy associated with autism and attention deficit hyperactivity disorder: Is there a genetic link?[J]. Brain and Development, 2013.

[5] Faught E, Richman J, Martin R, et al. Incidence and prevalence of epilepsy among older US Medicare beneficiaries[J]. Neurology, 2012, 78(7): 448-453.

[6] Ricker J H. Differential diagnosis in adult neuropsychological assessment[M]. Springer Publishing Company, 2004.

[7] International League Against Epilepsy (ILAE)

[8] Lo-Castro A, Curatolo P. Epilepsy associated with autism and attention deficit hyperactivity disorder: Is there a genetic link?[J]. Brain and Development, 2013.

[9] Olsson I, Steffenburg S, Gillberg C. Epilepsy in autism and autisticlike conditions: a population-based study[J]. Archives of Neurology, 1988, 45(6): 666.

[10] Holdsworth L, Whitmore K. A study of children with epilepsy attending ordinary schools. I: their seizure patterns, progress and behaviour in school[J]. Developmental Medicine & Child Neurology, 1974, 16(6): 746-758.

[11] Davies S, Heyman I, Goodman R. A population survey of mental health problems in children with epilepsy[J]. Developmental Medicine & Child Neurology, 2003, 45(5): 292-295.

[12] Sherman E, Slick D J, Connolly M B, et al. ADHD, Neurological Correlates and Health.related Quality of Life in Severe Pediatric Epilepsy[J]. Epilepsia, 2007, 48(6): 1083-1091.

[13] Tuchman R, Moshé L, Rapin I. Convulsing toward the pathophysiology of autism[J]. Brain and Development, 2009, 31(2): 95-103.

[14] Cascella N G, Schretlen D J, Sawa A. Schizophrenia and epilepsy: is there a shared susceptibility?[J]. Neuroscience research, 2009, 63(4): 227-235.