Evolutional changes and outcome of West syndrome: correlation with magnetic resonance imaging findings.

The prognosis and evolutional changes of 77 patients with West syndrome (WS) were studied after patients were classified into four groups on the basis of their magnetic resonance imaging (MRI) findings: anomaly, perinatal injury, normal, and the other groups. The average age at onset of spasms was earliest in the patients with anomalies and latest in patients with normal MRI findings. Patients with normal MRI findings had the shortest duration of spasms, and patients with anomalies had the longest duration of spasms. Antecedent seizures were observed in 6 patients (3 patients with anomalies, 1 patient with normal MRI findings, and 2 patients with other abnormalities). Thirty-five patients had subsequent seizures. Patients with anomalies often had partial seizures and patients with perinatal injuries often had generalized seizures. Seizures were infrequent in patients with normal MRI findings. Developmental outcome was best in the patients with normal MRI findings and worst in patients with perinatal injuries. Various types of epileptic syndromes occurred subsequent to WS in patients with anomalies, although nonspecific symptomatic generalized epilepsy was common in patients with perinatal injuries. These results suggest that seizure prognosis, evolutional changes in seizures, and developmental outcome are different among the types of brain lesions.