Locked-in syndrome due to tentorial herniation.

A 28-year-old man had a chronic locked-in syndrome following tentorial herniation caused by an epidural hematoma. Postmortem examination revealed bilateral corticospinal tract degeneration caudal to the midbrain, with infarction of the right internal capsule just rostral to the cerebral peduncle and pressure necrosis of the pyramidal portion of the left cerebral peduncle.