Locked-In syndrome

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".^[1]

Locked-in syndrome is also known as Cerebromedullospinal Disconnection,^[2] De-Efferented State, Pseudocoma,^[3] and ventral pontine syndrome.

The phrase "Locked-In syndrome" was created by Plum and Posner in 1966.^[4][5]

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Presentation

Locked-in syndrome results in 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 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.

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:

• Traumatic brain injury
• Diseases of the circulatory system
• Medication overdose
• Damage to nerve cells, particularly destruction of the myelin sheath, caused by disease (e.g. central pontine myelinolysis secondary to rapid correction of hyponatremia).
• A stroke or brain hemorrhage

Treatment

There is no standard treatment for Locked-In syndrome, nor is there a cure. Stimulation of muscle reflexes with electrodes (Neuromuscular stimulation) has been known to help patients regain some muscle function. Other courses of treatment are often symptomatic.^[6]

New direct brain interface mechanisms may provide future remedies.^[7]

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.

Assistive technology

See:

• Dasher

Notable case

Parisian journalist Jean-Dominique Bauby had a stroke in 1995, and when he awoke 20 days later he found that his body had stopped working: he could only control his left eyelid. By blinking his eye he dictated a letter at a time and in this way he wrote The Diving Bell and the Butterfly.^[8]

Cultural references

• (1844) In Dumas's The Count of Monte Cristo, Monsieur Noirtier de Villeforte becomes locked-in after suffering a stroke.
• (1989) The Metallica music video for the single "One" features a young soldier who is fully conscious but cannot move his body at all or communicate. It is edited from the 1971 film adaptation of Johnny Got His Gun, which the band bought outright so that they could produce the video.
• (2001) Bernard Werber - L'ultime Secret (The Ultimate Secret): one side of two parallel stories is about broken life of a modest bank clerk in Nice, Jean-Louis Martin, victim of a car accident to Locked-In Syndrome ("Immured alive", whose brain continues to function, the rest of the nerve system being paralysed) (list of works)
• (2003) In the first of Mark Billingham's novels featuring London detective Tom Thorne, Sleepyhead, a murderer is able to induce locked-in syndrome by manipulating cranial pressure points.
• (2003) German electronic-industrial band SITD, on their album Stronghold, released a song entitled "Locked In Syndrom," discussing the condition and its effects.
• (2004) In the first episode of CSI: NY, the only witness to a series of murders is a woman with locked-in syndrome.
• (2006) In the episode "His Story III" of Scrubs, a patient with locked-in syndrome is featured.
• (2007) In episode #315 "The Little Things You Do Together" of Desperate Housewives, Gloria Hodge suffers a massive stroke that leaves her paralyzed and unable to speak but otherwise cognitively aware.

References