CARPAL TUNNEL SYNDROME

DEFINITION

Carpal tunnel syndrome (CTS) is a disorder caused by pressure on the median nerve in the wrist. Numbness and tingling are characteristic symptoms of the disorder.

DESCRIPTION

The carpal (pronounced CAR-pull) tunnel is an area in the wrist formed by bones and ligaments. It provides a protected passageway for the median nerve. The median nerve is responsible for feelings and movement in the hand, especially the thumb and first three fingers. When pressure is applied to the median nerve, the hand feels as if it has gone to sleep.

Carpal Tunnel Syndrome: Words to Know

Carpal tunnel:

A passageway in the wrist, created by bones and ligaments, through which the median nerve passes.

Electromyography:

A test used to measure how well a nerve is functioning.

Median nerve:

A nerve that runs through the wrist and into the hand, providing feeling and movement to the hand, thumb, and fingers.

Carpal tunnel syndrome is most common among women between the ages of thirty and sixty. The disorder is a major cause of missed workdays because of the pain it causes. In 1995 about $270 million was spent for sick days taken as a result of CTS-related problems.

CAUSES

The carpal tunnel is a narrow passageway. Any swelling in this area causes pressure on the median nerve. That pressure eventually makes it difficult for a person to use the hand normally. Some conditions that can lead to pressure on the median nerve include pregnancy, obesity (see obesity entry), arthritis (see arthritis entry), diabetes (see diabetes mellitus entry), certain diseases of the thyroid and pituitary glands, and injuries to the arm and wrist.

One of the most common causes of CTS is repetitive motion. Repetitive motion is any activity that a person performs over and over again. Typing, working at a computer keyboard or cash register, playing some kinds of musical instruments, and working at certain types of factory jobs may involve repetitive motion. Repetitive motion forces a person to use the wrist over and over again and can lead to swelling in the carpal tunnel area, subsequent pressure on the media nerve, and thus to CTS.

SYMPTOMS

Symptoms of carpal tunnel syndrome include numbness, burning, tingling, and a prickly pin-like sensation in the palm of the hand, thumb, and fingers. Some individuals notice a shooting pain that starts in the wrist and goes up into the arm or down into the hand and fingers. CTS can also lead to muscle weakness in the hand. A person may have difficulty opening jars and holding objects. In advanced cases, hand and thumb muscles may actually decrease in size. If left untreated, CTS can result in permanent weakness in the hand and fingers, loss of feeling, and even paralysis of the thumb and fingers.

DIAGNOSIS

The first step in diagnosing carpal tunnel syndrome is a simple one. The doctor asks the patient to hold his or her hand in position with the wrist bent for about a minute. The presence of the symptoms described suggests the presence of CTS. The doctor may also perform other simple tests to measure muscle strength and feeling in the hand and arm. Additional tests may be used to rule out other problems. For example, an X ray can show that a tumor is causing pressure on the median nerve.

The doctor may also order an electromyograph (pronounced e-LEK-tromy-uh-graf) of the affected area. An electromyograph measures the speed with which nerve transmissions move through the median nerve. It indicates the amount of damage that has been done to the nerve.

TREATMENT

The first step in treating carpal tunnel syndrome is to immobilize the wrist, that is, prevent it from moving. A splint around the wrist is used for this purpose. Some people get relief from CTS by wearing the splint at night. Others may also need to wear the splint during the day.

Certain drugs may be prescribed to reduce pain and swelling. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (pronounced i-byoo-PRO-fuhn), are commonly used for this purpose. In advanced cases of CTS, injections of steroids may be necessary. Steroids also reduce pain and swelling.

In the most serious cases of CTS, surgery may be necessary. The doctor cuts a ligament in the wrist, increasing the size of the carpal tunnel. This procedure results in decreased pressure on the median nerve and, therefore, less pain for the patient. This procedure is almost always done in a doctor's office. A local anesthetic is used to numb the hand and wrist. The patient usually recovers quickly.

PROGNOSIS

Without proper diagnosis and treatment, carpal tunnel syndrome may lead to permanent damage to the affected hand. In most cases, splints and anti-inflammatory drugs are able to control the symptoms of CTS. For those who require surgery, about 95 percent will get complete relief from the disorder.

PREVENTION

The goal of CTS prevention is to reduce the amount of repetitive motion that places stress on the wrist. Ergonomics (pronounced ur-ga-NAHM-iks) can be a major help in reaching this goal. Ergonomics works with the design of machines and other equipment to make them less stressful for humans. For example, research in ergonomics has led to the development of new computer keyboard designs that are easier and less stressful to use. The early use of splints can also help prevent people at risk for CTS from developing the condition.

FOR MORE INFORMATION

Books

Butler, Sharon J. Conquering Carpal Tunnel Syndrome and Other Repetitive Strain Injuries. Oakland, CA: New Harbinger Publications, 1996.

Crouch, Tammy. Carpal Tunnel Syndrome and Repetitive Stress Injuries: The Comprehensive Guide to Prevention, Treatment and Recovery. Berkeley: North Atlantic Books, 1996.

Pascarelli, Emil. Repetitive Strain Injury: A Computer User's Guide. New York: John Wiley & Sons, 1994.

Periodicals

Brody, Jane E. "Experts on Carpal Tunnel Syndrome Say that Conservative Treatment is the Best First Approach." New York Times (February 28, 1996): p. 89+.

Glazer, Sarah. "Repetitive Stress Injury: A Modern Malady." Washington Post (March 12, 1996): p. WH12.