Mirror movements in the alien hand syndrome. Case report

The alien hand syndrome has been associated with different descriptions of abnormal motor behavior. We report on two patients with transient left hemiparesis who remained with limb apraxia and were particularly impaired by a variety of involuntary skilled movements of their apractic limb. After the report and a review of the literature, we discuss the presence of one type of abnormal movement observed in this syndrome. These movements resemble the mirror movements seen in the normal development of motor control and in some pathologic conditions later. Their appearance in the alien hand syndrome seems to demand both intrahemispheric and interhemispheric motor pathway damage.