Locked-in syndrome

Locked-in syndrome
Specialty	Neurology

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.

Locked-in syndrome is also known as Cerebromedullospinal Disconnection, De-Efferented State, Pseudocoma, and ventral pontine syndrome.

Presentation

It 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.

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. 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.

Notable cases

Parisian journalist Jean-Dominique Bauby had a stroke in 1995, and when he awoke 20 days later he found that his body had all but 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.

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 full conscious but cannot move his body at all or communicate.
• (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.
• (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 (tv series), a patient with locked-in syndrome is featured.
• (2007) In episode #315 The Little Things You Do Together of Desperate Housewives (tv series), Gloria Hodge suffers a massive stroke that leaves her paralyzed and unable to speak but otherwise cognitively aware.
• (2007) An account of a New Zealand man living with locked-in syndrome: http://tvnz.co.nz/view/video_popup_windows_skin/1059923?bandwidth=128k (11:40)

References

• lockedinsyndrome at NINDS
• tbi at NINDS (Traumatic Brain Injury)
• Locked-in.nl (in Dutch)