Locked-In Syndrome

If you try to read the medical literature on this subject, you will find that the term locked-in syndrome has been applied to more than one medical syndrome, including some caused by stroke and at least one psychiatric condition. The specific syndrome I will address in this article refers to a very rare outcome of stroke, caused by a stroke in a small, but important area of the brain. This area, located in the brain stem, is a conduit zone for the brain's motor pathways.

Large areas of the outer surface of the brain are associated with functions, such as receiving and processing visual information from the eyes or sensory information from the skin. Other large areas send signals out of the brain. These are mostly signals of the motor system, by which we tell our muscles to contract and move our limbs. All of the brain cells devoted to the motor system are spread out over large areas of the brain surface, and send out their signals via long wire-like extensions, called axons, downward through the brain, brainstem, and spinal cord, eventually transmitting to nerves that run out to the muscles.

As the axons leave the large motor areas on the brain surface and descend toward the brain stem, they converge on one another to form a tight bundle called the motor tract. A dime-sized stroke near the surface of the brain, where brain cells and their wires are spread out, may not cause significant disability. But in the brainstem motor tracts, where all of the motor axons from both halves of the brain are tightly packed together, a dime-sized stroke can lead to total paralysis.

In a classic complete locked-in syndrome, the victim's ability to move all the limbs, the trunk, the neck and even muscles of the face is completely destroyed; he lies completely motionless and devoid of expression and speech. Breathing may or may not be impaired. Some victims may need the assistance of a breathing tube and a respirator machine. Feeding must be given by a tube in the stomach.

Eye movement, however, usually remains intact, so he can look about and follow moving objects. If there has been no extension of the stroke to sensory tracts (which also bundle tightly in the brainstem), then the patient can still feel touch, pressure, and (importantly) pain sensation in all parts of the body. Perhaps most important is the fact that, barring more stroke damage in other parts of the brain, the victim's ability to feel emotions, hear and understand spoken language, read, and think complex thoughts remains unimpaired. Thus, the pejorative term "vegetable" cannot be applied to such a person! The victim can even learn to communicate by looking successively at different words or letters on a communication board held in front of him, or by learning to use Morse Code in eye blinks. In many cases, the syndrome is incomplete and there may be residual movement in the face, speech muscles, or other body parts. In other cases, more extensive areas of brain damage may impair other functions mentioned above.

The initial care of a locked-in person, after the acute medical issues are resolved, involves total care. Urine and bowel output must be drained or cleaned away regularly. The victim must be turned and rotated frequently to avoid the formation of bedsores, which can lead to infected ulcers deep enough to destroy muscle and bone. Feedings are usually maintained via a thin tube going directly through the wall of the abdomen into the stomach. Since the victim cannot communicate discomfort or wants, his needs must me anticipated and met by diligent caregivers. The victim's needs include companionship and the variety of daily experiences that any person would crave. Profound disability is long-term or even permanent. However, even a victim who appears to have the complete locked-in syndrome immediately after a stroke may recover some motor function over time, even enough to perform a few simple tasks by himself.

© Mayank Pathak, M.D.

SAFE (Stroke Awareness for Everyone, Inc.) has been given permission to reproduce this article by its author, Mayank Pathak, M.D. Dr. Pathak is Staff Physician, at The Parkinson's and Movement Disorders Institute, Fountain Valley, California.

For further locked-in-syndrome resources—including a supportive message board, survivor and caregiver listings, and information on assistive devices—please visit Brain Stem Stroke, Locked-In Syndrome online.