What is it?

Locked-in syndrome is a condition, in which a patient is aware and awake, but cannot move or communicate due to complete paralysis of nearly all voluntary muscles in the body. It is the result of a brain stem lesion in which the ventral part of the pons is damaged. The condition has been described as "the closest thing to being buried alive".

Locked-in syndrome is also known as cerebromedullospinal disconnection, de-efferented state, pseudo coma, and ventral pontine syndrome. The term for this disorder was coined by Plum and Posner in 1966.

Presentation

Locked-in syndrome is usually the result of quadriplegia and inability to speak in otherwise cognitively-intact individuals. Those with locked-in syndrome may be able to communicate with others by coding messages by blinking or moving their eyes, which are often not affected by the paralysis. Patients who have locked-in syndrome are conscious and aware with no loss of cognitive function.

They can sometimes retain proprioception and sensation throughout their body. Some patients may have the ability to move certain facial muscles, most often some or all of the extraocular eye muscles.

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.

Causes

Unlike persistent vegetative state, in which the upper portions of the brain are damaged and the lower portions are spared, locked-in syndrome is caused by damage to specific portions of the lower brain and brainstem with no damage to the upper brain.
Possible causes of locked-in syndrome include:

Number of cases

In the United States, there are no statistics available on how many people have locked-in syndrome but it is estimated that several thousand patients each year survive the kind of brain-stem stroke that causes the condition.

Treatment

There is no standard treatment for locked-in syndrome, nor is there a cure. Stimulation of muscle reflexes with electrodes (NMES) has been known to help patients regain some muscle function.

Other courses of treatment are often symptomatic. Assistive computer interface technologies, such as Dasher in combination with eye tracking may be used to help patients communicate. New direct brain interface mechanisms may provide future remedies.

Prognosis

It is extremely rare for any significant motor function to return. The majority of locked-in syndrome patients do not regain motor control, but devices are available to help patients communicate.

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.

Source: Wikipedia