What is "locked-in syndrome"

n. (context medicine neurology English) A rare, severe physical disorder in which a person cannot speak and is paralyzed—with the possible exception of some voluntary eye movement—while his or her mental faculty remain fully intact.

Locked-in syndrome (LIS) is a condition in which a patient is aware but cannot move or communicate verbally due to complete paralysis of nearly all voluntary muscles in the body except for the eyes. Total locked-in syndrome is a version of locked-in syndrome wherein the eyes are paralyzed as well. Fred Plum and Jerome Posner coined the term for this disorder in 1966. Locked-in syndrome is also known as cerebromedullospinal disconnection, de-efferented state, pseudocoma, and ventral pontine syndrome.