The alien hand sign--case report and review of the literature.

The alien hand sign refers to a group of signs which include a feeling that the hand is foreign together with autonomous activity, as if the hand is driven by an external agent. These features are commonly associated with frontal and callosal lesions. We report the alien hand sign in a man with left medial cortical infarct, presenting with autonomous grasping and groping with his right upper limb, denial of ownership of his limb, and dissociative phenomena including self restriction and intermanual conflict.