Periodic Limb Movements in a Comatose Patient: Case Report.

Periodic limb movements (PLMs) may occur as a primary condition or be associated with other pathologies, such as sleep disorders. However, PLMs have not been described in comatose patients. We report the case of a 66-year-old man, with no history of sleep disorders, who presented PLMs during coma caused by an extensive right hemispheric abscess inducing midline shift. These movements were further characterized by video and electromyographic recordings, which displayed bilateral periodic bursts of the tibialis anterior muscles, occurring every 7 to 15 seconds, with no concomitant electroencephalographic correlate. After a long period of hospitalization, the patient eventually regained consciousness and PLMs seem to persist, only in sleep. To the best of our knowledge, this is the first report showing that PLMs may be observed in a setting where the networks supporting consciousness are lost, namely in a coma of structural etiology.