[Risk factors for the occurrence of recurrent convulsions following an initial febrile convulsion].

The results of a follow up study of 155 Dutch children who visited the emergency room of an urban paediatric hospital after experiencing their first febrile seizure are presented. Median follow up time was 38 months (range 27-60). Of these 155 initially untreated children 58 (37%) suffered at least one, 47 (30%) at least two and 27 (17%) at least three recurrent seizures. The recurrence hazard after any seizure was highest in the first six months, and dropped markedly after 6 months without seizures. The effect of the various postulated risk factors on the occurrence of any recurrent seizure and three or more recurrences was assessed. A first degree family history of febrile or nonfebrile seizures appears to be a predictor of multiple recurrences; an age of at least 30 months and a temperature of 40.0 degrees C or higher at the initial seizure are associated with a decreased risk. Several factors act together on the risk of recurrent seizures, sometimes in opposite directions. By considering the action of all relevant factors (age at onset, family history and features of the initial febrile seizure) subgroups of children with one year seizure recurrence rates as low as 15% and as high as 48% were identified.