Locked-In Syndrome Explained
Locked-in syndrome is a rare 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. In French, the condition is described as “maladie de l’emmure vivant”, literally translated as walled-in alive disease.
The official medical term for the disease is cerebromedullospinal disconnection, pseudocoma, or ventral pontine syndrome.
The condition can result from several factors. It can be the caused by a stroke at the basilar artery which feeds blood to the pons (the upper portion of the brainstem), traumatic brain injury, diseases of the circulatory system, medication overdose, or damage to the myelin sheath of the nerve cells. Cerebral air embolism and transient vertebrobasilar insufficiency are potentially reversible causes.
Patients with locked-in syndrome are conscious and aware with no loss of cognitive function. The can sometimes retain proprioception (an awareness of the positioning of the body) and sensation. Some patients may have the ability to move certain facial muscles, but most cannot chew, swallow or speak. The vocal cords are typically not paralyzed, but locked-in syndrome patients cannot coordinate breathing and voice, which restricts them from making voluntary sounds. The patient may be able to communicate with others by blinking or moving his eyes, which often are not affected.
In the United States, there are no statistics available on the number of people who have locked-in syndrome. It is estimated that several thousand patients each year survive the type of brainstem stroke that causes the condition. 90% die within the first four months of onset.
There is no standard treatment or cure. It is rare for any significant motor function to return except when the cause of the condition can be reversed, such as in the case of Guillain-Barre syndrome. Stimulation of muscle reflexes with electrode, a therapy called functional neuromuscular stimulation, has been known to help patients regain some muscle function.