Locked-in syndrome

Locked-in syndrome
Classification and external resources
Locked-in syndrome can be caused by stroke at the level of the basilar artery denying blood to the pons, among other causes.
ICD-10	G46.3
ICD-9	344.81
MeSH	D011782

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 except for the eyes. Total locked-in syndrome is a version of locked-in syndrome where the eyes are paralyzed as well.^[1] 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". In French, the common term is "maladie de l'emmuré vivant", literally translated as walled-in alive disease; in German it is sometimes called "Eingeschlossensein".^[2]

Locked-in syndrome is also known as cerebromedullospinal disconnection,^[3] de-efferented state, pseudocoma,^[4] and ventral pontine syndrome.

The term for this disorder was coined by Plum and Posner in 1966.^[5][6]

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.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 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.^[7] This restricts them from producing voluntary sounds, even though the vocal cords themselves are not paralysed.^[7]

Causes

In children, the most common cause is a stroke of the ventral pons.^[8]

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, usually of the basilar artery

Number of cases

In the U.S, 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.^[9] 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.^[10][11]

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.^[12]

Notable cases

Jean-Dominique Bauby

Parisian journalist Jean-Dominique Bauby suffered a stroke in December 1995, and when he awoke 20 days later he found that his body was almost completely paralyzed: he could control only his left eyelid. By blinking this eye, he slowly dictated one alphabet character at a time and, in so doing, was able over a great deal of time to write his memoir The Diving Bell and the Butterfly. A few days after it was published in March 1997, Bauby died of pneumonia.^[13] The 2008 film The Diving Bell and the Butterfly is a screen adaptation of Bauby's memoir.

Julia Tavalaro

In 1966, Julia Tavalaro, then aged 32, suffered two strokes and a brain hemorrhage and was sent to Goldwater Memorial Hospital on Roosevelt Island, New York. For six years, it was believed she was in a vegetative state. In 1972, a family member noticed her trying to smile after she heard a joke. After alerting doctors, a speech therapist, Arlene Kratt, discerned cognizance in her eye movements. Kratt and another therapist, Joyce Sabari, were eventually able to convince doctors that she was in a locked-in state. After learning to communicate with eye blinks in response to letters being pointed to on an alphabet board, she became a poet and author. Eventually, she gained the ability to move her head enough to touch a switch with her cheek, which operated a motorized wheelchair and a computer. She gained national attention in 1995 when The Los Angeles Times Magazine published her life story. It was republished by Newsday on Long Island and in other newspapers across the country. She died in 2003 at the age of 68.^[12][14]

Gary Griffin

Gary Griffin was a veteran of the United States Air Force who became immobile due to amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease). He was later equipped with a device called the NeuroSwitch which allows him to control a computer and communicate with his family. Sensors are attached to the skin over a patient’s muscles and signals are sent to an interface that translates the slightest muscle contractions into usable code. A video of Griffin and his use of the NeuroSwitch has been posted on Youtube.^[15]

Erik Ramsey

In 1999, 16-year-old Erik Ramsey suffered a stroke after a car accident that left him in a locked-in state. His story was profiled in an edition of Esquire magazine in 2008. Erik is currently working with doctors to develop a new communication system that uses a computer that, through implants in his brain, reads the electronic signals produced when he thinks certain words and sounds. At present, Erik is only able to communicate short and basic sounds. However, doctors believe that within a few years, Erik will be able to use this system to communicate words, phrases and eventually, to "talk" normally.^[12][16]

Rom Houben

In 1983, Rom Houben survived a near-fatal car crash and was diagnosed as being in a vegetative state. 23 years later, with the help of modern brain imaging techniques and equipment, doctors were able to properly diagnose his condition as locked-in syndrome.^[17] Now he apparently communicates by typing into a keyboard with his right hand^[18], though he does so via a facilitator who moves or helps him move his hand^[19].

Houben's case calls into question the current methods of diagnosing vegetative state and arguments against withholding care from such patients.^[17][20][21]

Popular culture

• On the TV program CSI: NY's first season episode "Blink", a disgraced Russian doctor working in New York as a cabbie experiments on his female passengers and a woman who was staying with the doctor and his wife. Detective Mac Taylor is only able to communicate with the final victim by her blinking twice for yes and once for no.
• Locked-in syndrome was a diagnosis given to Jean-Pierre, one of the main characters in Bernard Werber's novel L'ultime secret.
• Locked-in syndrome secondary to leptospirosis was the case study for Dr. Gregory House and his team in the season 5 episode Locked In of the US TV Drama House, MD.
• In a play named "Pills, Thrills and Automobiles," one of the characters (Eddie) is left in a locked in state due to a car crash.^{[citation needed]}
• In Alexandre Dumas' novel The Count of Monte Cristo, Monsieur Noirtier de Villefort is stricken with locked-in syndrome after a stroke and communicates with his granddaughter Valentine using only movements of his eyes and eyelids.
• The main character also suffers from this in the Star Wars: Galaxy of Fear book, City of the Dead.
• In the book "The Second Opinion" by Michael Palmer, there is a character with locked-in syndrome who communicates with his daughter by movements of his eye.
• On the TV show Scrubs fifth season in episode 19 "His Story III" a character, Mr. McNair suffers from Locked-In Syndrome, and communicates with his eye movements.
• In the book "Sleepy Head" by Mark Billingham D.I. Tom Thorn hunts a man trying to cause locked-in syndrome in women across London
• In the Star Trek episode "The Menagerie", fleet captain Christopher Pike is paralyzed, mute, badly scarred, and dependent on a brainwave-operated wheelchair. His only means of communicating is through a light on the chair: one flash meaning "yes" and two flashes indicating "no".

References

External links

• Locked-in Syndrome Association's guide to communicating without language (French)