闭锁综合征（Locked-in syndrome）是指患者虽然意识清醒，但却由于全身随意肌（除眼睛外）全部瘫痪，导致患者不能活动、不能自主说话的一种综合征。如果患者眼睛也瘫痪，则被称为完全性闭锁综合征，它是闭锁综合征的一种特殊形式。闭锁综合征是在1966年由美国神经学家弗雷德·普拉姆（Fred Plum）和杰罗姆·波斯纳（Jerome Posner）首先提出。闭锁综合征有时也被称为脑延脊髓中断（cerebromedullospinal disconnection）、去传出状态（de-efferented state）、假性昏迷（pseudocoma）、脑桥腹外侧综合征（ventral pontine syndrome）或基督山综合征（Monte-Cristo syndrome）。

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.