Carpal Tunnel Syndrome

Overview

Carpal tunnel syndrome is a painful condition caused by repetitive movements which put pressure on the median nerve in the wrist. It most often occurs in people over the age of 50 and is more common in women than men. In the past decade there have been more and more cases of workers afflicted with CTS perhaps because of increased automation and job specialization that has fragmented tasks to the point where a given job may involve only a few manipulations performed over and over again during the course of a day.

Symptoms

Symptoms usually start gradually. You may feel burning tingling or itching numbness in the palm of the hand and the fingers especially the thumb and the index and middle fingers. Some people say their fingers feel swollen even though little or no inflammation is apparent. Symptoms often first appear during the night with sufferers waking up feeling the need to "shake out" the hand or wrist.

As symptoms worsen you might feel tingling during the day and your grip won't be as strong as it usually is. You might find it more difficult to form a fist hold on to small objects squeeze things or perform other manual tasks.

Causes

The carpal tunnel is a narrow rigid passageway of ligament and bones at the base of the hand. Repetitive flexing and extension of the wrist may cause a thickening of the protective sheaths which surround each of the tendons. This thickening from irritated tendons or other swelling narrows the tunnel and causes the median nerve to be compressed at the wrist. This nerve controls sensations to the palm side of the thumb and all but the little finger as well as impulses to some small muscles in the hand that allow the fingers and thumb to move.

Sometimes no specific cause can be identified but it is thought that some people may have a congenital predisposition to CTS because their carpal tunnel is smaller than most. Other contributing factors include:

  • sprain or fracture or other trauma or injury to the wrist that causes swelling
  • an overactive pituitary gland
  • hypothyroidism
  • rheumatoid arthritis
  • mechanical problems in the wrist joint
  • work stress
  • repeated use of vibrating hand tools
  • fluid retention during pregnancy or menopause
  • the development of a cyst or tumor in the canal

There are also certain factors that may increase your risk of getting carpal tunnel syndrome:

  • Women are three times more likely than men to develop carpal tunnel syndrome
  • People with diabetes or other metabolic disorders that directly affect the body's nerves and make them more susceptible to compression are also at high risk.
  • Carpal tunnel syndrome is especially common in people who perform assembly line work

Treatment

Early diagnosis and treatment are important to avoid permanent damage to the median nerve. Initially this generally involves resting the affected hand and wrist for at least 2 weeks and avoiding activities that may worsen symptoms. Sometimes a splint is used to immobilize the wrist to avoid further damage.

Nonsteroidal anti-inflammatory drugs such as aspirin ibuprofen and other nonprescription pain relievers may ease symptoms. If necessary your doctor can give you a corticosteroid shot in the wrist which will immediately relieve pressure on the medien nerve.

If symptoms don't ease within six months surgery may be recommended. This involves severing the band of tissue around the wrist to reduce pressure on the median nerve. The procedure is usually done as outpatient day surgery.

Additional Resources:

The Arthritis Society