Risk Factors of Unprovoked Seizures after Acute Symptomatic Seizures in Children

Abstract

Purpose : Acute symptomatic seizure is defined as a temporary seizure together with acute systemic, metabolic, or toxic insult in association with an acute central nervous system insult. And unprovoked seizure is defined as seizure without provocating factors. We studied the risk factors of unprovoked seizures after acute symptomatic seizure in children. Methods : We retrospectively reviewed the records of one hundred and ten children with acute symptomatic seizures who were admitted to the pediatric department of Chungbuk National University Hospital between January, 1998 and December, 2003. We analyzed overall risk factors of unprovoked seizures after acute symptomatic seizures involving etiology, incidence, type of seizure, duration and neuroimaging. Results : We analyzed records of 110 children with acute symptomatic seizures aged from 1 month to 17 years. 24 children had unprovoked seizures (21.8%) after acute symptomatic seizures. Causes in order of frequency were encephalopathy, central nervous system infection, brain tumor, cerebrovascular disease. The risk of unprovoked seizure was significantly greater for those with status epilepticus (68.4%) than without status epilepticus, with partial seizure (64.7%) than generalized seizure. And the risk of unprovoked seizure was strongly associated with abnormal finding of electroencephalogram (79.1%) and neuroimaging (41.6%). Conclusion : In conclusion, the leading cause of subsequent unprovoked seizure in children with acute symptomatic seizure was encephalopathy and age specific incidence was high in the group aged 24-72 months. The risk for subsequent unprovoked seizure was greater for those with partial seizure, status epilepticus, abnormal finding of neuroimaging and electroencephalography.