[Alien hand syndrome: a review of the literature]

Alien hand syndrome (AHS) is a rare neurological disorder, but is an important condition because of its disabling impact on the daily life. The common feature of AHS is the involuntary, autonomous motor activity of the affected limb and the denial of limb ownership, characterized by involuntary, uncontrollable, and purposeless movements.

AHS as a nosologic entity has been modified during the last decades, being able to be a result of several diseases involving corpus callosum or medial frontal cortex, although some authors reported cases of AHS in patients due to posterior cerebral lesions. Frontal AHS occurs in the dominant hand, is associated with grasping, groping and compulsive manipulation of tools. Callosal subtype is characterized by inter-manual conflict and was the first to been described en the context of callosal disconnection.

Alien hand behaviours are increased in conditions of fatigue or anxiety and are usually elicited by nearby objects. The rehabilitative treatment, targeted toward the specific needs of each patient, could allow the improvement of the activities of daily life.