Purpose: To underline the unusual but possible occurrence of epileptic spasms (ES) in children >1 year of age.
Methods: Cases in whom onset of spasms occurred after 1 year of age were identified through a retrospective review of the records of all patients referred for ES to the Saint-Vincent de Paul Hôpital (Paris) and American Memorial Hospital (Reims) between 1974 and 1994.
Results: Eighteen cases were identified among the 734 children referred for ES, 18 cases were identified where spasm onset time ranged from 12 to 38 months of age. In 1/3 of the cases, the diagnosis was suspected from the onset of clinical manifestations; in the remaining 2/3, diagnosis was delayed by a mean 6 months (range, 2-25 months). Neurobehavioral regression affected two-thirds of the patients. Modified hypsarrhythmia was present in 11 patients; all but one exhibited major and diffuse spike- and slow-wave activity. EEG abnormalities were detected in the frontal areas in 11 patients. Spasms were cryptogenic in 9 patients. Steroids were administered to 13 patients; these controlled the spasms in 6 patients. Outcome was favorable for both seizures; cognition favorable in only 2 of the 18 patients.
Conclusions: Beginning after the first year of life, ES, or late-onset infantile spasms, are distinct from early Lennox-Gastaut syndrome, although etiology, prognosis and treatment are similar to that for the classical infantile spasms.