Alien Hand Syndrome
Onorio Eugene D’Adamo
Charter Oak State College
Alien Limb Syndrome (ALS), also termed Alien Hand Syndrome, (AHS),is primarily a degenerative condition (corticobasal) that affects the hands and arms in the majority of the documented cases. The alien hand syndrome is a Psychomotor disorder defined by a dissociation between intention and action. One of the patient's hands performs apparently purposeful movements, which are independent of purposeful control, as if the hand is driven by an external agent. The symptoms vary according to location of the lesion (Arberlaiz et al. 1993). Although the definition to the locations and damage involved in the AHS, how or why each case appears to be unique remains a mystery.
In this paper the introductions, methods, discussions and results sections of peer reviewed and scholarly articles on the subject will be summarized. These summaries will be compared for overall thoroughness and content. Further discussion will also be offered as recommendations for research and treatment.
Keywords: alien hand syndrome; corpus callosum; callosal lesions.
Alien hand syndrome is defined according to Amar and Tiwari (2007) “Alien limb syndrome (ALS) is a very rare condition where the affected persons are not able to recognize the affected limb as their own, and regard it as being foreign or alien to them.” Corticobasal Degeneration (CBD), also known as corticobasal ganglionic degeneration, is a debilitating disease with no identified cure or origin. The most common manifestation of this is alien hand syndrome, a group of symptoms dominated by involuntary movement of an upper limb in conjunction with experiencing an estrangement from the movements of the limb itself. Another explanation of this syndrome is according to Aboitiz et al. (2003) “We propose that the cases of alien hand described in the literature can be classified into at least five broad categories: diagnostic dyspraxia and related syndromes, alien hand, way-ward hand and related syndromes, supernumerary hands and agonistic dyspraxia.” Alien hand syndrome is presents with a cluster of symptoms characterized by the involuntary movement of a single upper limb in conjunction with the experience of estrangement from or personification of the movements of the limb itself. An anatomically derived definition of the alien hand syndrome has not been identified conclusively. A reason for this broadened acceptable application has been the identification of theoretically dissociable subtypes (Fan et al. 2004). Historical Review Alien hand or alien limb phenomenon has been defined as a syndrome where the patient complains that an arm or leg has a ‘life of its own’ and is almost always asymmetrical. The limb may move and even grasp objects involuntarily. This activity is best observed best by distracting the patient with other tasks and observing the limb as it act independently of the rest of the body (Fan et al. 2004). The history of Alien hand syndrome is the development after a Callosal interruption and almost exclusive to the left side with only 1-2% of the reported cases being right-side affected. The evaluation and determination of this phenomenon was that it is a disconnection of the area responsible for motor activity of the left side, (hand, leg) initiating from the right hemisphere of the brain where the motor cortex for the left hand and leg are located. The occurrence of this syndrome to the right side of the body has been identified as a double lesion both from the Corpus Callosum and the Supplementary Motor Area (Della Salla et al. 1991). Not all of the articles perused for this paper included identified introduction sections. Some started with abstracts and proceeded to the body of the article or to case studies. For the purpose of