Alien hand syndrome

Classification according to ICD-10
C71.9	Malignant neoplasm of the brain, unspecified
ICD-10 online (WHO version 2019)

The alien hand syndrome (AHS) is a previously rare described neurological disorder in which affected people one of the two hands is no longer subject to voluntary control. It is best documented in people in whom the corpus callosum (bar) is severed in the brain ( split-brain patient ). The disorder can also occur after a stroke or infection . It was first described in 1908 by the German neurologist Kurt Goldstein . The term alien hand syndrome comes from a paper from 1972 in which three cases of patients with a tumor on the corpus callosum were described who showed corresponding disorders of the control of one hand.

impact

The affected patients have little or no control over one hand, the so-called alien hand . They perceive this hand as strange and not part of their body. This hand often works against the other. This can lead, for example, to the person concerned wanting to eat something with their right hand and their left hand preventing them from doing so, or in extreme cases trying to strangle them.

Since the affected hand and thus the responsible hemisphere has no contact with the other, no information about a felt object can be recorded and processed even in times of conscious control. For example, it cannot be recognized whether an object is round or square.

causes

The exact causes, apart from indications of the spatial localization of the corresponding functional disorders in the brain, are not yet known. It is assumed that two different forms can be distinguished.

In one form there is damage to the corpus callosum, and in some cases to the frontal lobe . In these patients, the left hand is usually affected. A severing or other damage to the corpus callosum leads to a disruption of communication between the two hemispheres of the brain. Since each half of the brain is responsible for controlling the opposite half of the body, the left hand is only subject to the control of the right side of the brain in such a case. However, in addition to controlling the right half of the body, the left side of the brain is also generally responsible for logical-analytical thought processes and for the control of complex fine-motor movement processes through the exchange of information with the right half of the brain via the corpus callosum. In these patients, the left hand is no longer subject to this function of the left hemisphere. This form is often characterized by the fact that the affected hand is mainly active when the unaffected hand is also performing movements.

In a second form, there is only damage to the frontal lobe, while the corpus callosum is not affected. The frontal lobe contains areas of the brain that are important for the planning and voluntary execution of movements. In affected patients, the hand on the dominant half of the body is usually affected, in most cases the right. What is noticeable about this form is often an obsessive-compulsive reaching for objects that are in the patient's field of vision.

treatment

There are currently no treatment options for Alien Hand Syndrome, however, improvement often occurs on its own after a certain period of time.

See also

• Bristowe Syndrome

literature

• PG Gasquoine: Alien hand sign. In: Journal of Clinical and Experimental Neuropsychology , Vol. 15, No. 5, September 1993, ISSN  1380-3395 , PMID 8276927 , pp. 653-667.

Web links

• Daniela Ovadia: Exotic disease: tormented by the ghost hand Spiegel.de on December 17, 2006.

Individual evidence

1. ^ S. Brion, CP Jedynak: Rev Neurol (Paris). 1972 Apr; 126 (4): 257-66

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !