Locked-in syndrome.

Locked-in syndrome is a rare neuropsychological disorder. Its primary features are quadriplegia and paralysis of the cranial nerves except for those responsible for vertical eye movements. The differential diagnosis includes persistent vegetative state, brain death, minimally conscious states, C3 transection of the spinal cord, and conversion locked-in syndrome. Etiologies of locked-in syndrome include hemorrhagic and thrombotic events, tumors affecting the ventral pons, infectious agents, iatrogenic causes, trauma, metabolic abnormalities, and other miscellaneous causes. The clinical manifestations, differential diagnosis, neuropsychological assessment, rehabilitation, and prognosis of patients with locked-in syndrome are discussed.