CARPAL TUNNEL SYNDROME

(CTS) a painful condition caused by repetitive flexing or stressing of the wrist over a lengthy period of time. CTS is caused by pressure on the median nerve, which carries nervous impulses back and forth between the hand and the spinal cord. The wrist joint is formed by a set of bones called the carpal bones. The carpal tunnel is a small passage on the inner side of the wrist that is bounded on three sides by the carpal bones and on the fourth by a ligament. Through the carpal tunnel pass nine tendons that flex the fingers; i.e., enable them to close, as when making a fist. The median nerve also passes through the carpal tunnel. During movements of the fingers and wrist, the finger flexor tendons rub against the walls of the carpal tunnel. This may cause swelling of the tendons, and, because there is little room for them to expand, they squeeze against the median nerve, which is the softest tissue in the tunnel. This pressure causes the numbness, tingling, and pain in the wrist and hand that are the primary symptoms of CTS. If the pressure on the nerve worsens, affected individuals may temporarily lose control of some of the hand muscles and experience difficulties in picking up or holding objects. CTS typically occurs in workers who do repetitive hand tasks or whose tasks require awkward hand positions; repeated, forceful gripping or grasping motions; or mechanical stress on the palms. CTS occurs most commonly in assembly-line workers and in people who spend prolonged periods of time typing on computer keyboards. Avoiding or reducing the activity responsible for the syndrome often alleviates the symptoms in mild cases. More serious cases are relieved by anti-inflammatory drugs while the patient wears a wrist brace or splint. Surgery is also sometimes necessary to correct the condition.