Understanding Carpal Tunnel Syndrome

Where Is the Carpal Tunnel?

Carpal Tunnel
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The median nerve travels from the forearm into your hand through a "tunnel" in your wrist. The bottom and sides of this tunnel are formed by wrist bones. The top of the tunnel is covered by a strong band of connective tissue called a ligament (transverse ligament).

What Else Is in the Tunnel?

Wrist and carpal tunnel structures.
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The tunnel also contains nine tendons that connect muscles to bones and work to bend your fingers and thumb. These tendons are covered with a lubricating membrane, called synovium. The synovium may enlarge and swell under certain conditions.

How Is Damage Done to the Carpal Tunnel?

Wrist Pain and Mouse
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If the swelling is sufficient, it may cause the median nerve to be pressed up against the transverse ligament, causing what is known as carpal tunnel syndrome. The syndrome may be associated with various conditions, such as rheumatoid arthritis, or it may be unrelated to any other condition.

Is There Another Reason for Carpal Tunnel Syndrome?

Carpal tunnel surgery
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Some cases of carpal tunnel may be due to enlargement of the median nerve rather than compression from surrounding tissues. Carpal tunnel syndrome, however, is the most common and widely known of the entrapment neuropathies in which the body's peripheral nerves are compressed or traumatized.

What Are the Symptoms of Carpal Tunnel Syndrome?

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Symptoms of carpal tunnel syndrome usually start gradually, with frequent burning, tingling, or itching numbness in the palm of the hand and the fingers (especially the thumb, index, and middle fingers). There may be the sensation of swelling even if no swelling is apparent.

Symptoms typically occur during the night, in one or both hands. As symptoms become more severe, tingling can be felt during the day. Clumsiness, decreased grip strength, and problems with tasks requiring manual dexterity may develop.

Treatment of Carpal Tunnel Syndrome - Splinting

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Early diagnosis and treatment is important to avoid permanent damage to the median nerve. Conservative treatments are usually tried before surgery is considered. In mild cases, splinting the wrist in a neutral position may relieve symptoms.

Treatment of Carpal Tunnel Syndrome - Medications

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Oral medications may be used to relieve the symptoms of carpal tunnel syndrome, such as:

Local injections of corticosteroids into the carpal tunnel area may be tried to help nonspecific or inflammatory tenosynovitis.

Surgical Treatment of Carpal Tunnel Syndrome

Carpal tunnel syndrome surgery.
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When conservative treatments fail, surgical decompression of the tunnel by release of the transverse carpal ligament and removal of tissue compressing the median nerve can be beneficial. Carpal tunnel release is one of the most common surgical procedures in the United States.

The procedure is generally recommended if symptoms persist for 6 months. Even after surgery though, symptoms may recur. It is important to treat carpal tunnel syndrome. Left untreated, there may be permanent nerve or muscle damage.


NIH Publication No 03-4898