In Stanley Kubrick's movie Dr Strangelove,1 the main character is described as "erratic" and displays a bizarre movement disorder. His right hand seems to be driven by a will of its own, at times clutching his own throat and at other times raising into a Nazi salute. Dr Strangelove must try to restrain this wayward limb with his left hand. Bizarre as this fictional character is, a similar movement disorder can occur in neurologic disease. The complex phenomenon associated with this disorder falls under the rubric of alien hand syndrome. This syndrome is characterized by a limb that seems to perform meaningful acts without being guided by the intention of the patient. Patients find themselves unable to stop the alien limb from reaching and grabbing objects, and they may be unable to release these grasped objects without using their other hand to pry open their fingers. These patients frequently express astonishment and frustration at the errant limb. They experience it as being controlled by an external agent and often refer to it in the third person. This article outlines the origins of the terminology used in describing this syndrome, early observations, and studies regarding its functional neuroanatomy.
Biran I, Chatterjee A. Alien Hand Syndrome. Arch Neurol. 2004;61(2):292-294. doi:10.1001/archneur.61.2.292