Late-Onset Epileptic Spasms: Clinical Evidence and Outcome in 34 Patients.

To evaluate the diverse presentation and course of late-onset epileptic spasms in relation to etiology, we analyzed the clinical, electroencephalographic (EEG), and prognostic features in 34 patients. We divided the patient sample into cryptogenic or symptomatic based on etiology. An association emerged between symmetric spasms at onset and focal interictal EEG abnormalities in cryptogenic patients, and onset with focal or generalized seizures before displaying asymmetric spasms, and multifocal or diffuse EEG abnormalities, in the symptomatic group. Despite an overall poor prognosis, symptomatic patients starting with generalized seizures seem to have a relatively more favorable outcome. The high occurrence of intellectual disability, and sometimes psychomotor regression, confirmed this rare and poorly understood heterogeneous clinical condition as a severe form of epileptic encephalopathy that deserves further study.