L O C K E D IN S Y N D R O M E
Locked-in syndrome, or LIS for short, is a condition in which a patient is aware and awake 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 where the eyes are paralyzed, as well.
The term for this disorder was coined by Fred Plum and Jerome Posner in 1966.
Locked-in syndrome is also known as cerebromedullospinal disconnection, de-efferented state, pseudocoma, and ventral pontine syndrome.
PRESENTATION
Locked-in syndrome usually results in quadriplegia and the inability to speak in otherwise cognitively intact individuals.
hose with locked-in syndrome may be able to communicate with others through coded messages by blinking or moving their eyes, which are often not affected by the paralysis.
The symptoms are similar to those of sleep 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 bodies.
Some patients may have the ability to move certain facial muscles, and most often some or all of the extraocular eye muscles.
Individuals with the syndrome lack coordination between breathing and voice. This restricts them from producing voluntary sounds, though the vocal cords are not paralysed.
TREATMENT
Neither a standard treatment nor a cure is available. 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, combined with eye tracking, may be used to help patients communicate.
New direct brain interface mechanisms may provide future remedies; one effort in 2002 allowed a fully locked-in patient to answer yes-or-no questions.
Some scientists have reported that they have developed a technique that allows locked-in patients to communicate via sniffing.