The incidence, etiology, seizure characteristics, and outcome in childhood convulsive status epilepticus (CSE) are reviewed by researchers from Great Ormond Street Hospital for Children, and the Institute of Child Health, London, UK. Neonatal seizures require separate consideration and were excluded. Despite attempts to modify the definition of CSE, without a set temporal criterion (ILAE (2001), or a duration as low as 5 min (operational definition), there is no clear reason to modify the “traditional” 30-min-duration definition. By 30 min CSE has become self-sustaining, drug resistance has occurred, and neuronal injury has begun.

Etiology is an important determinant of CSE, and a significant proportion of cases are associated with fever. ILAE classification of SE according to etiologies (1993) lists 1) acute symptomatic - previously neurologically normal child, within 1 week of underlying etiology including CNS infection, prolonged febrile seizure, encephalopathy, head trauma, cerebrovascular disease, metabolic or toxic; 2) remote symptomatic - preexisting CNS disorder >1 week before; 3) idiopathic epilepsy related; 4) cryptogenic epilepsy related; and 5) Unclassified. This classification should be revised, with febrile CSE as a distinct category with an overall favorable prognosis, and separate from acute symptomatic CSE.

Incidence estimates of CSE in children are few, the most recent conducted in North London, the only study of a wholly pediatric population. The incidence of childhood CSE in North London is 18-20/100,000/year, higher than the 4-6/100,000/year reported in adults, excluding the elderly. The incidence in children less than 1 year is 51/100,000/year, compared to those aged 1-4 (29/100,000/year). The higher frequency of CSE in the very young is related to a high proportion of acute symptomatic causes, to brain immaturity, or congenital, genetic, and metabolic disorders in this age group. Future studies should clarify the role of CSE in mesial temporal sclerosis and seizures, and identify specific ethnic, genetic, or socioeconomic factors in etiology and methods of CSE prevention. [1]

COMMENT. In a current Dutch study of SE in children with epilepsy, 41 (8.3%) of 494 had one or more episodes of SE at the time of epilepsy diagnosis. Three had febrile SE, followed by unprovoked seizures, and 38 were unprovoked SE [2]. After 5 year follow-up, 31.7% of patients with SE at onset had a shorter terminal remission <1 year compared to 21.2% of those without SE. Mortality was not significantly increased for children with SE. Risk factors for SE at onset of epilepsy were remote symptomatic and cryptogenic etiology, and a history of febrile seizures. SE during the course of the epilepsy has a worse prognosis and a high recurrence rate of SE.