What is locked-in syndrome?
Locked-in syndrome is a rare situation in which a person is wakeful and aware but has quadriplegia and paralysis of the lower cranial nerves that does not allow the person to show facial expressions or make muscular movements such as moving limbs, swallowing, speaking, or breathing. The affected person cannot communicate except by eye movements (blinking, and some patients may possess vertical eye movements). The patients, however, have the ability to see and hear and have normal intelligence and reasoning capabilities. Total locked-in syndrome occurs when the eyes are also paralyzed. Locked-in syndrome has also been termed cerebromedullospinal disconnection, de-efferented state, pseudocoma, and ventral pontine syndrome.
What causes locked-in syndrome?
Locked-in syndrome usually results from a brainstem hemorrhage or infarct resulting in quadriplegia and disruption of the lower cranial nerves. Other potential causes that can affect this part of the brainstem can include trauma, tumors, infection, loss of myelin (protective insulation of nerves), polymyositis (inflammation of the nerves), and other disorders such as ALS (amyotrophic lateral sclerosis) or medication overdose.
What are the symptoms and signs of locked-in syndrome?
The signs and symptoms of locked-in syndrome are as follows:
- Quadriplegia and paralysis that is global except for vertical eye movements and blinking
- A coma-like condition (pseudocoma) where the patient only can respond or communicate with others by eye movements
- Unresponsiveness to painful stimuli (inability to withdraw an extremity from painful stimuli)
- No horizontal eye movements
- Cannot consciously chew food, swallow, breathe, speak, or move voluntary muscles
- Must rely on caregivers for most basic functions (body movements and hygiene, for example)
- Fully alert and aware of the environment
- Ability to see, hear, and have normal sleep-wake cycles
- Ability to think and reason normally
A concussion is a traumatic brain injury.
Locked-in Syndrome Causes: Brain Hemorrhage
A brain hemorrhage is bleeding in or around the brain. Causes of brain hemorrhage include high blood pressure, abnormally weak blood vessels that leak, drug abuse, and trauma. Many people who experience a brain hemorrhage have symptoms as though they are having a stroke, and can develop:
- weakness on one side of their body,
- difficulty speaking, or
- a sense of numbness.
Difficulty performing usual activities, including problems with walking or even falling, are not uncommon symptoms. About 10% of all strokes are hemorrhagic, or caused by bleeding into the brain.
How is locked-in syndrome diagnosed?
Locked-in syndrome may be difficult to diagnose in some patients initially because some patients may be comatose for a while and then develop locked-in syndrome; some patients with a new onset stroke may resemble individuals with locked-in syndrome. The diagnosis can be missed if eye movement (vertical and blinking) is not assessed in seemingly unresponsive patients. Evidence for locked-in syndrome can be seen with MRI imaging of the specific brain area that shows damage. In addition, PET and SPECT brain scans can further assess the patient's abnormality. About half of patients with locked-in syndrome are discovered (diagnosed) by family members that realize the patient is aware and able to respond (communicate), usually with their eye movements. Other tests such as EEGs show normal sleep-wake patterns.
What is the treatment for locked-in syndrome?
There is no specific treatment for locked-in syndrome. Supportive care is the main treatment for locked-in syndrome. Supportive care includes the following:
- Breathing support
- Good nutrition
- Preventing complications of immobilization such as lung infections, urinary tract infections, and blood clot formation
- Preventing pressure ulcers
- Physical therapy to prevent contractures
- Speech therapy to help in developing communication via eye blinks and/or eye vertical movements
- Possibly, computer terminal control linked to the patient's eye movements
Infrequently, treatment of the underlying cause such as shrinking a tumor or rapidly treating a medical overdose may improve the patient's condition.
Is recovery from locked-in syndrome possible?
Depending upon the cause (for example, transient blood loss to the brainstem), rarely, a person may recover, although complete recovery is highly unusual. The majority of patients with this syndrome do not recover although they may learn to communicate using eye movements.
What statistics are associated with locked-in syndrome?
About half of all patients with locked-in syndrome are initially found to be aware and able to communicate with others by family members who visit the patient regularly and communicate to the patient's physicians that they suspect the patient is conscious and aware of their surroundings. The other half of patients are diagnosed by their physicians. Although locked-in syndrome can affect anyone at any age, it is most often seen in adults that are at higher risk for brain strokes and bleeding problems. The number of those affected by locked-in syndrome is unknown, because it is rare and often either misdiagnosed or not recognized.
What is the prognosis with locked-in syndrome?
The prognosis of patients with locked-in syndrome varies from fair to poor. Those patients that are diagnosed early and get supportive care that includes development of ways to communicate with other people usually do better than those diagnosed at a later time (sometimes months to years later). Patients that learn to communicate may have a survival rate of 80% after 10 years.
The majority of patients with locked-in syndrome do not recover functionality; most will be entirely dependent upon caregivers for most of their basic functions (feeding, cleaning, changing positions in bed, for example). Rarely, the patient may recover some basic functionality.
Can locked-in syndrome be prevented?
Prevention of trauma that leads to locked-in syndrome is possible, but difficult to predict. Avoiding lifestyles that lead to coronary artery disease which, in turn, can result in strokes may prevent locked-in syndrome in some patients; but because this syndrome is rare, there are little or no data to support this speculation.
See brain scan pictures of Alzheimer's and types of dementia
Additional information on locked-in syndrome
The family and friends of a patient with locked-in syndrome may want to better understand the patient's condition. Some physicians and families suggest reading a book written by Jean-Dominique Bauby, a patient with locked-in syndrome called, The Diving Bell and the Butterfly: A Memoir of Life in Death. The book has also been made into a movie by the same name.
Additional information may be obtained by contacting the following:
NIH National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
Phone: (301) 496-5751
Toll-free: (800) 352-9424
United States Society for Augmentative and Alternative Communication
100 E. Pennsylvania Avenue, Courtyard
Towson, MD 21286 USA
Toll-free: (877) 887-7222
Subscribe to MedicineNet's General Health Newsletter
Medically Reviewed on 11/9/2018
Medically reviewed by Jon Glass, MD; American Board of Psychiatry and Neurology with Sub-specialty in Neurology
"Locked In Syndrome." National Organization for Rare Diseases (NORD). 2015.