Risk factors were identified in 69 children with a first febrile seizure compared to 99 matched controls seen in a three year period at the Bronx Municipal Hospital Center, Montifiore Medical Center, and North Central Bronx Hospital, and Albert Einstein College of Medicine, New York. Multivariable analysis of data obtained from medical records and parent interviews showed that the height of body temperature and family history of febrile seizures were significant independent risk factors. The risk of having a febrile seizure almost doubled for each 0F above 101. An association between otitis media and seizure frequency was related to the higher fevers with this infection. Gastroenteritis was not a factor and may have had a protective effect, although none had Shigella. A history of febrile seizures in at least one first-degree relative was obtained in 17 (25%) cases compared to 5 (5%) controls. Maternal smoking during pregnancy showed a significant predisposing trend. [1]

COMMENT. A previous study of 110 patients with febrile seizures examined between 1956 and 1958, almost forty years ago, at the Bronx Municipal Hospital Center, and laboratory investigations involving four animal species, reported in a series of five articles from the Albert Einstein College of Medicine, had established the height of the body temperature as a measure of febrile seizure threshold and the important determinant of occurrence or induction of fever-induced convulsions. In individual patients and in the group as a whole, seizures occurred when the degree of fever reached or surpassed the threshold convulsive temperature. Contrary to previous reports, the rapidity of rise of temperature was not a predisposing factor. [2]

Age and maturity, changes in the balance of water and electrolytes in the brain, and various drugs were factors found to modify the threshold convulsive temperature in young animals. An antihistamine, diphenhydramine and the anticonvulsant, phenytoin lowered the threshold convulsive temperature and exacerbated fever-induced seizures, whereas phenobarbital and phetharbital elevated the threshold and prevented seizures [3]. See Progress in Pediatric Neurology II, 1994, ppl6-32, and I, 1991, ppl4-24, (edited by Millichap, PNB Publishers) for a compendium of more current articles on febrile seizures.