[A case of hemichorea presenting with inattention and denial of involuntary movement].

We report a case of hemichorea presenting inattention and denial of involuntary movement. A 64-year-old right-handed man was hospitalized with acute hemichorea on the right side of the body. The patient had hemichorea which was frequently followed by purposeful movement such as fumbling with his glasses or combing his hair. He claimed that the involuntary movements were habits showing both inattention and denial of the involuntary movements. These symptoms were very unique. On MRI of the brain, T2 elongated spots were detected at the bilateral pallidum, suggesting occulusive cerebrovascular disease. On 123I-IMP-SPECT hypoperfusion was observed at the right cerebral basal ganglia extending to the right medial frontal lobe. We supposed that this inattention and denial of involuntary movements were caused by dysfunction of the system connecting the medial frontal lobe with basal ganglia which was presented as hypoperfusion on SPECT.