[Serial changes of magnetic resonance imagings in acute disseminated encephalomyelitis]

We reported serial changes of MRIs in a case of acute disseminated encephalomyelitis (ADEM). On November 1, 1990, a previously healthy 73-year-old man had a grand mal seizure following myoclonic jerks of the right arm for six days. On admission, he was drowsy and presented with right facial palsy and incomplete tetraparesis. He became coma on the next day of admission. There was moderate leukocytosis. A spinal tap showed a normal opening pressure, 2 white blood cells/mm3, a total protein of 84 mg/dl, glucose of 89 mg/dl. CSF IgG (6.2 mg/dl) and myelin basic protein (6.7 ng/dl) were slightly increased. Serological examinations for virus titer were all negative. A CT scan on the 2nd day showed no abnormal findings, but MRI revealed small high intensity areas in the left thalamus, left prefrontal gyrus and right corona radiata, internal capsule on both the T2-weighted and proton density sequences. An MRI on the 14th day showed high intensity signals in the white matter of the bilateral frontal lobes, left operculum and right corona radiata. In contrast, the left thalamic lesion became smaller and less conspicuous than on the initial scans, but was enhanced with Gd on the T1-weighted sequences. Our findings indicate that MRIs are valuable in detecting pathophysiological changes of ADEM from the acute to chronic phases.