An epidemiological study of children with status epilepticus in Okayama, Japan

Background: The incidence of status epilepticus (SE) in Asian children, including Japanese, has not been reported. Methods: In 2003, we performed an epidemiological study of SE on Japanese children (31 days or older to <15 years of age) in Okayama City by ascertaining all lifetime first episodes of SE. Results: Thirty-seven patients (22 males and 15 females) were identified. The annual incidence of SE was 38.8 per 100,000 population (95% CI: 24.5-49.5). Febrile SE in the absence of CNS infection accounted for 17. Acute symptomatic etiologies other than febrile SE were observed in eight patients, including three cases of influenza encephalitis/encephalopathy. Five were classified as remote symptomatic and the remaining seven as cryptogenic. The highest incidence (155.1/100,000) was seen in the age range of 31 days or older to <1 year, followed by 101.5/100,000 in the age range of one year, and the incidence decreased after eight years. In 26 of the 37 patients, SE was their first seizure. As for seizure types, 32 had convulsive SE, including tonic status in one. Five others showed nonconvulsive SE, including complex partial SE in four and absence status in one. No one died of SE. Two patients who brought on SE because of influenza encephalitis/encephalopathy suffered from motor disturbance with or without mental disturbance after SE. Conclusions: The incidence of SE tended to be higher in Japanese children than reported in Caucasians. The Japanese had an age-specific incidence pattern similar to that of Caucasians.