Computed tomographic (CT) brain scans of patients with subacute necrotizing encephalomyelopathy (SNE) may reveal focal lesions that correspond to sites of anatomic involvement of the disease. Three patients with SNE were followed with serial CT brain scans. In two patients radiographic abnormalities appeared well after the onset of clinical symptoms. In all three patients the radiographic lesions changed with time. This variability seen with serial scanning is an important feature of SNE.