Carpal tunnel syndrome is a repetitive stress disorder caused by the compression of the median nerve in the carpal tunnel in the wrist that causes pain and numbness in the hand and fingers.
Rodney loved coaching his son John's Little League team. Shortly before the season began, though, Rodney took a new job on a small appliance assembly line. After a few weeks, his fingers began to tingle and hurt. When he was at baseball practice, he experienced pain while gripping the bat properly. When the pain did not get better, Rodney went to the doctor and complained that it hurt to cross his thumb over the palm of his hand and that the pain and tingling came and went but was worse at night.
The median nerve extends through the forearm into the palm of the hand where it divides and sends branches to the thumb and first three fingers. To reach the hand, the nerve passes through a narrow space, or tunnel, in the wrist formed by ligaments * and the carpal bones of the wrist. Carpal tunnel syndrome (CTS) occurs when this space becomes narrowed and the median nerve is compressed or irritated. Pressure on the median nerve causes numbness, weakness, and pain. If not corrected, CTS can result in permanent damage and loss of feeling in some fingers. It usually occurs in the dominant hand.
It is hard to estimate how many people develop CTS because many people with mild CTS do not see a doctor. One study found that as many as half of the people in high-risk occupations develop CTS. Another study estimated that 10 percent of people in the United States would have CTS at some point during their lifetime. Most people do not develop CTS until after age 35. Women are at least three times more likely to develop the condition than men. Researchers hypothesize that is because the space in the wrist that the median nerve must pass through is smaller in women to begin with, so it takes less narrowing to put pressure on the nerve.
CTS is common, especially among people who perform repeated motions with their hands and wrists or who use them in ways that are not ergonomically * correct. This is most common in assembly line work and warehouse employees. Athletes and musicians are affected as well. There are other causes of CTS, and often the cause is not clear. CTS affects some people who have synovitis * , arthritis * , diabetes * , thyroid disease, and acromegaly * . Injury to the wrist is another cause of CTS. Pregnant women sometimes retain fluid, making the ligaments in the carpal tunnel swell and causing CTS.
The doctor can usually diagnose CTS by having the patient do certain manipulations with his or her hands and noting whether these are painful. Another clue to CTS is that the little finger is not painful, because the median nerve does not send a branch to this finger. More extensive testing can be done to rule out other conditions, for example x-rays may be done to rule out a fractured wrist bone. Sophisticated tests can measure the speed at which the median nerve transmits impulses if a diagnosis of CTS is uncertain.
Mild CTS is usually treated by resting the wrists and then splinting them. Medications like nonsteriodal anti-inflammatories (NSAIDS) will help with pain but do not solve the problem. Alternative therapies can also help with pain. Exercises taught by a physical or occupational therapist can restore normal use of the hand, wrist, and arm without need for surgery.
However, the best way to treat CTS caused by repetitive motion is to eliminate the cause, which could mean allowing assembly line workers to switch jobs frequently during their shift or purchasing ergonomically correct office equipment and computer keyboards.
Advanced CTS may be treated by the injection of cortisone * or a related medication into the wrists. In severe cases of CTS, the doctor may recommend a surgical procedure called carpal tunnel release. This surgery cuts a band of tissue in the wrist so that the space for the median nerve is widened. The procedure is usually done as outpatient surgery and does not require hospitalization. If left untreated, CTS can cause permanent nerve damage. With early treatment and lifestyle modifications most people achieve pain relief.
See also Repetitive Stress Syndrome • Strains and Sprains
Johnson, Jim. Treat Your Own Carpal Tunnel Syndrome: Treatment and Prevention Strategies for Individuals, Therapists, and Employers. Indianapolis, IN: Dog Ear Publishing, 2014.
Seradge, Housang. “Carpal Tunnel Syndrome Exercises.” http://www.eatonhand.com/hw/ctexercise.htm (accessed November 27, 2015).
Arthritis Foundation. “Carpal Tunnel Syndrome Relief.” http://www.arthritis.org/living-with-arthritis/life-stages/work/carpaltunnel-relief.php (accessed November 27, 2015).
American Academy of Orthopaedic Surgeons. 6300 N. River Rd., Rosemont, IL 60018-4262. Telephone: 847-823-7186. Website: http://orthoinfo.aaos.org (accessed November 27, 2015).
Association for Repetitive Motion Syndromes. PO Box 471973, Aurora, CO 80047-1973. Telephone: 303-369-0803. Website: http://www.certifiedpst.com/arms (accessed November 27, 2015).
National Institute of Neurological Disorders and Stroke. PO Box 5801, Bethesda, MD 20828. Toll-free: 800-352-9424. Website: http://www.ninds.nih.gov/disorders/carpal_tunnel/carpal_tunnel.htm (accessed November 27, 2015).
* ergonomics (er-go-NOM-iks) is a science that helps people to know the best postures and movements to use while working, in order to avoid injury and discomfort.
* synovitis (sin-o-VY-tis) is inflammation of the membrane surrounding a joint.
* arthritis (ar-THRY-tis) refers to any of several disorders characterized by inflammation of the joints.
* diabetes (dye-uh-BEE-teez) is a condition in which the body's pancreas does not produce enough insulin or the body cannot use the insulin it makes effectively, resulting in increased levels of sugar in the blood. This can lead to increased urination, dehydration, weight loss, weakness, and a number of other symptoms and complications related to chemical imbalances within the body.
* acromegaly (akro-MEG-al-ee) is a disease in which the pituitary gland secretes too much growth hormone with the effect of gradual and permanent enlargement of flat bones, the hands and feet, abdominal organs, and some facial features.
* ligaments (LlG-a-ments) are bands of fibrous tissue that connect bones or cartilage, supporting and strengthening the joints. Ligaments in the mouth hold the roots of teeth in the tooth sockets.
* cortisone (KOR-ti-zone) is a medication used to relieve inflammation.