Hemichorea-hemiballism and anosognosia following a contralateral infarction of the caudate nucleus and anterior limb of the internal capsule.

The authors describe a patient who experienced the sudden occurrence of hemicorea-hemiballism on the left side of the body and the contemporary agnosia of it. An unenhanced CT-scan disclosed an ischemic lesion involving the head of the caudate nucleus and of the anterior limb of the internal capsule of the contralateral hemisphere. The authors discuss the possible pathophysiologic mechanisms explaining the rare association of these two symptoms and suggest that the involvement of the pyramidal tract in the internal capsule usually does not allow hyperkinesis to manifest itself.