How many alien hand syndromes? Follow-up of a case.

We report the follow-up of a patient affected by a persistent alien left nondominant hand. CT and MRI showed an ischemic lesion localized to the mesial frontal region and involving the supplementary motor area and anterior fibers of the corpus callosum. These findings support theories suggesting a critical role of both these lesions in determining "chronic" forms of alien hand of either upper limb.