Etiologic factors and long-term prognosis of convulsive disorders in the first year of life.

Etiological factors and long-term prognosis were studied in 562 cases with convulsive disorders in the first year of life; 114 (20.3%) were prenatal, 114 (20.3%) perinatal, 24 (4.3%) postnatal, and 257 cases (45.7%) were cryptogenic. The remaining 53 (9.4%) patients were doubtful cases. The mortality before six years of age of the pre- and perinatal cases at 17.6% and 15.7%, respectively was significantly higher than in the other etiologic groups. The incidence of a family history of epilepsy or other convulsive disorders was highest in the cryptogenic cases (23.5%), and lowest in the prenatal cases (10.4%) (p less than 0.05). The onset of seizures was very early in the pre- and perinatal groups and they decreased in number after four months of age, whereas cryptogenic cases increased after four months of age. With regard to the seizure types in the first year of life, infantile spasms occurred most frequently as the initial seizures in the prenatal (62.8%) and doubtful (50.9%) group, and generalized motor seizures in the cryptogenic (78.8%) group. The prognosis of seizures and mental and physical development was much better in cryptogenic cases. More than 80% of cases with cryptogenic etiology became seizure-free, mentally and physically normal, whereas in other etiologic groups the rate was much lower.