MRI - Multiple sclerosis: This 35-year-old woman with a history of migraine headaches presented with a two-week history of slurred speech and trouble walking. Her examination was significant for slight left hemiparesis, brisk jaw jerk and bilateral hyperreflexia. Laboratory data demonstrated oligoclonal banding in the cerebrospinal fluid. These FLAIR-weighted axial MR images show multiple high signal lesions within the periventricular white matter. On the sagittal image on the right the signals emanate radially from the corpus callosum.