Using magnetic resonance imaging (MRI), we studied the myelination of the brains of 8 patients with West syndrome. All cases were symptomatic, 2 having severe asphyxia, 1 lissencephaly, 1 Leigh encephalopathy, and 4 with normal brain imaging. The myelination pattern was abnormal in all cases, with delayed myelination in 6 and hypomyelination in 2. The results suggest that West syndrome is associated with a specific pattern of myelination abnormalities. The study provides new insights into the pathophysiology of West syndrome and may have implications for the diagnosis and treatment of the disorder.