LOCKED-IN SYNDROME [ back to Glossary Index ]
Locked-In Syndrome exists when a patient with a stroke, advanced Parkinson's, advanced ALS, or other neurologic condition, cannot communicate his thoughts or feelings through words or gestures because of complete muscular paralysis. Such patients are conscious, alert and have normal cognitive functions, but cannot express themselves to others because when their brain commands their body to act it does nothing in response. Stroke can kill the cortico-spinal nerve switching stations which direct movement commands from the brain through the spinal cord. Parkinson's involves depletion of the neurotransmitter dopamine, without which movement commands will not be communicated. ALS kills upper motor neurons necessary to transmit movement commands into the muscles. Occasionally a severe TBI can produce the same result. Some of the "luckier" patients retain voluntary movement of their eyelids and can communicate through blinking. In the past, the patients without control over their eyelid muscles had no means to communicate with others. This is beginning to change with the very recent invention of biomedical devices such as direct implantation of a glass cone with an internal electrode into the brain, which signals a computer which then translates the signals into impulses which drive a cursor on a computer screen.