Mirror movements and involuntary homolateral limb synkinesis in a patient with probable Creutzfeldt-Jakob disease.

We report a 63-year-old man, who was diagnosed with probable Creutzfeldt-Jakob disease, manifested by rapid progressive cognitive decline, gait disturbance, right focal hand dystonia, myoclonus, mirror movements, and involuntary homolateral limb synkinesis during alternating limb movements. Although the exact pathophysiology for contralateral and homolateral limb synkinesis is not known, dysfunction of the secondary motor areas and dorsal premotor cortex by spongiform degeneration of gray matter may cause these abnormalities.