The locked-in syndrome consists of almost complete paralysis. Awareness and mental function are not affected. People cannot make facial expressions, move, speak, or communicate on their own, but they can move their eyes up and down and blink.
Locked-in syndrome is usually caused by a stroke but may be caused by Guillain-Barré syndrome or cancer that affects a certain part of the brain.
People with this syndrome cannot move their lower face, chew, swallow, speak, move their limbs, or move their eyes from side to side, but they can usually see, hear, move their eyes up and down, and blink.
To identify locked-in syndrome, doctors test people who do not move and appear unresponsive by asking them to open and close their eyes, and they do imaging tests to identify the cause.
Treatment includes treating the cause (if identified), providing good nutrition, preventing problems due to not being able to move (such as pressure sores), and providing communication training.
Locked-in syndrome usually results from a stroke. But it may result from
Any disorder (such as brain cancer, an infection, or a head injury) that destroys the middle part of the brain stem but does not affect the parts of the brain that control consciousness and mental function (the upper part of the brain stem and the cerebrum, which is the largest part of the brain)
Certain toxic substances, such as insecticides, or overuse of opioids
Rarely, complete paralysis of peripheral nerves and muscles, as may result from severe Guillain-Barré syndrome or from cancer that affects the middle part of the brain stem or the area around it
Symptoms of Locked-In Syndrome
People with locked-in syndrome cannot move their lower face, chew, swallow, speak, move their limbs, or move their eyes from side to side. They may have difficulty breathing but can see and hear.
Locked-in syndrome resembles stupor or coma because people have no obvious way of responding even though they are fully conscious. However, most can move their eyes up and down and blink. If caregivers do not notice the eye movements, people with locked-in syndrome may mistakenly be thought to be unaware of their surroundings and unable to think or communicate.
People with locked-in syndrome can learn to communicate by opening and closing their eyes in response to questions. Some people with locked-in syndrome can learn to communicate using a computer that interprets brain activity and that can be controlled by eye movements and sometimes by other means.
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Diagnosis of Locked-In Syndrome
A doctor's evaluation
Imaging tests such as magnetic resonance imaging
Because locked-in syndrome can be mistaken for stupor or coma, doctors test people who do not move and appear unresponsive by asking them to open and close their eyes.
Imaging tests of the brain, such as magnetic resonance imaging (MRI) and computed tomography (CT), are done to determine the cause, particularly to check for any treatable disorders that may be contributing to the problem.
If the diagnosis is in doubt, doctors may do other imaging tests, such as electroencephalography (EEG), positron emission tomography (PET), single-photon emission computed tomography (SPECT), functional MRI, or evoked responses.
Treatment of Locked-In Syndrome
Preventive measures for problems due to immobilization
Good nutrition
Communication training
Early treatment involves correcting any conditions that may contribute to the syndrome. People who have difficulty breathing may need assistance with breathing, such as mechanical ventilation.
Long-term care
Like people in a coma, people in a locked-in syndrome require comprehensive care.
Providing good nutrition (nutritional support) is important. People are fed through a tube inserted through the nose and into the stomach (called tube feeding). Sometimes they are fed through a tube inserted directly into the stomach or small intestine through an incision in the abdomen. Medications may also be given through these tubes.
Many problems result from being unable to move, and measures to prevent them are essential. For example, the following can happen:
Pressures sores: Lying in one position can cut off the blood supply to some areas of the body, causing skin to break down and pressure sores to form.
Weak muscles and nerve damage: When muscles are not used, they waste away (atrophy) and become weak. Lying in one position for a long time can put enough pressure on a nerve to damage it.
Contractures: Lack of movement can also lead to permanent stiffening of muscles (contractures) causing joints to become permanently bent.
Blood clots: Lack of movement makes blood clots more likely to form in leg veins.
Pressure sores can be prevented by frequently repositioning the person and placing protective padding under parts of the body that are in contact with the bed, such as the heels, to protect them.
To prevent muscle weakness, nerve damage, and contractures, physical therapists gently move the person’s joints in all directions (passive range-of-motion exercises) or splint joints in certain positions.
Preventing blood clots includes use of medications and compression or elevation of the person's legs. Moving the limbs, as occurs in passive-range-of-motion exercises, may also help prevent blood clots.
Because people are incontinent, care should be taken to keep the skin clean and dry. If the bladder is not functioning and urine is being retained, a tube (catheter) may be placed in the bladder to drain urine. Catheters are carefully cleaned and regularly examined to prevent urinary tract infections from developing.
Communication training
People with the locked-in syndrome can learn to communicate using a computer input device controlled by eye movements. Other devices can detect when people sniff slightly. These devices can also be connected to a computer and used to communicate. Speech therapists can help people develop a communication code using eye blinks or sniffs. If they recover use of another body part (such as a thumb or the neck), they can communicate in other ways.
However, these methods are tiring and slow. So other methods are being developed using electrodes that are attached to the scalp or implanted in the brain. The electrodes can detect electrical signals produced by nerve cells. These signals are sent to a computer and processed. They can be used to move cursors on a computer screen, operate a robotic arm, and produce computer-generated speech.
Other issues
Because communication can usually be established, affected people should make their own health care decisions. However, affected people are often very depressed and may need to be advised by a compassionate mental health care practitioner, especially when they are considering future medical interventions and life support measures.
If present, depression is treated.
Prognosis for Locked-In Syndrome
Whether people recover depends on the cause and its severity, as in the following examples:
If the cause is a small stroke and people are not completely paralyzed, people may recover completely or enough to do some daily tasks, such as eating and speaking, on their own.
If the stroke is large, most people need full-time nursing care permanently.
If the cause is Guillain-Barré syndrome, people may improve over several months, but recovery is seldom complete.
If the cause is a progressive disorder such as cancer, death usually results.
