The risk of epilepsy after febrile convulsions was determined in a national population based study in the United Kingdom and reported from the Department of Paediatrics, Addenbrooke’s Hospital, Cambridge and the Institute of Child Health, University of Bristol, England. Of 16,004 neonatal survivors born during 1 week in April 1970 and enrolled in the British Birth Survey, 398 (2.7% of those followed) had at least 1 febrile convulsion by 10 years of age. The ratio of simple to complex febrile seizures was 4 to 1. Those with complex febrile convulsions had a significantly greater incidence of febrile seizure recurrences than the simple febrile seizure group. Prophylactic anticonvulsants were prescribed for longer than a month in only 14% of patients; the seizure was simple in 26 and complex in 14. Afebrile seizures developed in 13 patients (3.4%) and 9 (2.3%) had epilepsy or recurrent afebrile seizures. Complex febrile convulsions and especially focal febrile convulsions were predictive of epilepsy. Afebrile complex partial seizures occurred in 9.4% of children with prolonged febrile convulsions. Of 14,278 children in this study who had no febrile convulsions, 53 (0.4%) developed epilepsy by the age of 10 years. 
COMMENT. Complex febrile convulsions (longer than 15 minutes, focal, or multiple) accounted for 20% of the febrile seizures in this study, an incidence identical with that reported by pediatricians in the United States . In contrast, complex and simple febrile seizures are seen with equal frequency in pediatric neurology practice in the U.S. . Compared to the United Kingdom where prophylactic anticonvulsants are used infrequently (14% of patients), in the United States long-term phenobarbital is prescribed by 89% of pediatric neurologists for the prevention of complex febrile seizures and by 43% for simple febrile seizures. Parental anxiety was a factor in the prescription of anticonvulsants by 67% of respondents to a questionnaire. Despite the publicity regarding adverse effects on behavior and cognition, phenobarbital therapy is still favored by the majority of pediatric neurologists in the U.S., particularly in the prevention of complex febrile seizures. The recent Seattle study  failed to convince members of the Child Neurology Society that phenobarbital has any long-term persistent adverse effects on cognition and they are skeptical of the claim that phenobarbital is ineffective in the control of febrile seizures. The viewpoint stated in an editorial  that prophylactic anticonvulsants are rarely needed and have no long term benefit in febrile convulsions is shared by only 17% of pediatric neurologists in the United States.
Several factors might explain the transatlantic differences in the management of febrile seizures: 1) a greater availability and reliance on rectal diazepam for use by parents in the U.K., 2) geographic considerations and the greater distances to hospitals for emergency room treatment of the acute seizure in rural areas of the U.S., 3) the apparent importance of parental anxiety and physician concern for litigation in the U.S. Therapeutic guidelines may be helpful but the decision to treat must be made on an individual basis. When further and more carefully evaluated, perhaps the EEG will prove of value and receive attention in febrile seizure management.