Evolutional Changes and Outcome of West Syndrome: Correlation with Magnetic Resonance Imaging Findings

Abstract

Summary:The prognosis and evolutional changes of 77 patients with West syndrome (WS) were studied after patients were classified into four groups op 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 MFU 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. Key Words: West syndrome-Magnetic resonance imaging.West syndrome (WS) is an age-dependent epileptic syndrome caused by various brain disorders. WS has been frequently classified into two groups: cryptogenic and symptomatic. The prognosis and evolutional changes of WS have usually been discussed according to this classification. Because the symptomatic WS group consists of patients with numerous types of brain lesions, the prognosis and evolutional changes may be different among the types of brain lesions. Magnetic resonance imaging (MRI) provides us with detailed information about brain lesions (1,2). In the present study, we studied the prognosis and evolutional changes of WS after classifying the patients with WS into four major groups and several subgroups on the basis of their MRI findings. SUBJECTS AND METHODSPatients with WS, who were treated in Department of Pediatrics, Nagoya University Hospital, and three related institutions were evaluated. In this study, patients who met the following criteria were studied: (a) onset of WS between 1985 and 1994, (b) >2 years follow-up observation, and (c) performance of at least one cranial MRI. Eventually, 77 patients (46 boys and 3 1 girls) were studied. Twenty-three of them were born prematurely, and the corrected age was applied to the subsequent analysis of these patients. Seizures and epileptic syndromes were classified on the basis of their clinical manifestations and EEG according to the Classification of the International League Against Epilepsy (ILAE). WS was diagnosed when a patient had a series of spasms and showed hypsarrhythmia on their interictal EEG. Severe epilepsy with multiple independent spike f...

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