Locked-in syndrome is a rare neurological disorder characterized by complete paralysis of voluntary muscles in all parts of the body except for those that control eye movement. Total locked-in syndrome is a version of locked-in syndrome where the eyes are paralyzed as well. Locked-in syndrome is also known as cerebromedullospinal disconnection, de-efferented state, pseudocoma, and ventral pontine syndrome.

It may result from:

• Traumatic brain injury
• Diseases of the circulatory system
• Diseases that destroy the myelin sheath surrounding nerve cells
• Medication overdose

Individuals with locked-in syndrome are conscious and can think and reason, but are unable to speak or move. Individuals with locked-in syndrome lack coordination between breathing and voice. This restricts them from producing voluntary sounds, even though the vocal cords themselves are not paralysed. The disorder leaves individuals completely mute and paralyzed. Communication may be possible with blinking eye movements.

While in rare cases some patients may regain certain functions, the chances for motor recovery are very limited. Within the first four months after its onset, 90% of those with this condition die. However, some people with the condition continue to live much longer periods of time.

There is no cure for locked-in syndrome, nor is there a standard course of treatment. A therapy called functional neuromuscular stimulation, which uses electrodes to stimulate muscle reflexes, may help activate some paralyzed muscles. Several devices to help communication are available. Other treatment is symptomatic and supportive.