We describe a patient who presented with the clinicopathological features of corticobasal degeneration (CBD). Over the course of 8 years, the patient developed myoclonus, dystonia, and supranuclear gaze palsy associated with an akinetic-rigid syndrome. To our knowledge, no previous report of a patient with CBD has described clear-cut regional white matter changes as revealed by magnetic resonance imaging (MRI) scans. In our patient, a T2-weighted MR image of the brain showed focal atrophy of the bilateral frontal cortex and asymmetric regional hyperintensities of the subjacent white matter. These signal changes seemed to primarily reflect the progression of neuronal degeneration, especially the demyelination secondary to axonal loss or change.