Sleep disorder in alien hand syndrome.

A 63-year-old right-handed woman developed an alien hand syndrome (AHS) after an acute infarction in the territory of the left anterior cerebral artery. The uncontrolled hand movements were present during the daytime and eventually disturbed sleep. Polysomnography revealed that these motor actions only appeared when the patient was awake. These awakenings emerged mostly from NREM sleep stage 2 during the first half of the night. There was no evidence of any epileptiform activity, dyssomnia or parasomnia. These movements were controlled making her wear an oven mitt during sleep. The temporal distribution of this motor activity seems to follow the progressive hyperpolarization of anterior horn neurons that occurs when sleep deepens. The accommodation of the grasp reflex in AHS probably helps control this unwanted motor activity.