Heidi Moawad, MD, in a recent blog on the Neurology Times website, sheds some light on the rare neurological disorder alien hand syndrome.

Its main symptom, according to the blog, is a lack of voluntary hand control; the hand may move on its own, almost like it is being controlled by some outside force.

The affected hand is not weak but maintains normal strength, and the hand movements are not spastic or convulsive. Instead, the affected hand performs normal movements such as picking up objects and touching the face—but the actions are neither intentional, wanted, or expected.

Diagnosis can be challenging because alien hand syndrome is a neurological rather than a psychiatric disorder. Therefore, careful observation and evaluation of the patient is necessary for diagnosis versus any other condition that may be causing the symptoms.

Causes vary and may include stroke, the blog continues. Alien hand syndrome may occur after neurosurgical procedures, especially those involving an incision in the corpus callosum. Lesions including areas of the motor cortex or supplementary motor cortex may also be identified with alien hand syndrome. In addition, trauma and cancer may also cause the disorder.

Therapies that have been used to treat alien hand syndrome include those that are directed at muscle control, such as botulinum toxin and neuromuscular blocking agents, as well as cognitive therapy techniques.

[Source: Neurology Times]