Coping with carpal tunnel syndrome

You may first notice numbness or tingling in one or both of your hands. As time goes by, your condition may become painful, and you may find it more difficult to do simple tasks that involve your fingers and hands. Eventually, the tingling or pain in your hand may awaken you at night.

If you experience these symptoms, you may be one of the many people who suffer from a hand condition called carpal tunnel syndrome (CTS) – the best known of the so-called repetitive strain injuries. A study published in the Journal of the American Medical Association in 1999 suggests that CTS is fairly common, affecting nearly three percent of the general population in Sweden. Experts believe the prevalence in many countries is probably about the same.

Named after the part of your hand where the disorder originates, carpal tunnel syndrome affects more commonly the dominant hand. As an occupational injury, it’s brought on by repetitive work or movement. Carpenters, dentists, people working with electric drills or other vibrating instruments, sewing machine operators, needlepointers, piano players and, indeed, anyone who works with his or her hands for long hours can get CTS. So can tennis and squash players, aerobic dancers using hand weights, and people who frequently use rowing machines or other exercise equipment. Thousands of cases of CTS are diagnosed each year, and women are far more susceptible to it than men because women tend to do the kinds of industrial, office, and domestic jobs that promote CTS. And their carpal tunnel space is small to begin with.

Crowded House

Indeed, the carpal tunnel is by nature an anatomically crowded location (see illustration). It’s a narrow channel on the underside of either wrist with bones on three sides and a ligament on the other. The flexor tendons and a single nerve run through it.

Called the median nerve, it supplies sensation to your thumb, index, and middle fingers, and part of the ring finger. Trouble arises when the tendons in this confined space become inflamed and squeeze the median nerve inside the carpal tunnel. The tendons may swell for various reasons:

• Fractures and dislocations in the wrist that change the shape of the tunnel.

• Endocrine and metabolic disorders that increase fluid retention in the tendons (e.g. thyroid imbalance, diabetes, pregnancy and others).

• Long-term, sustained motion of the wrist and hand, such as the prolonged use of a computer. Repetitive twisting and turning also cause the tendons to swell.

Keys to Diagnosis

Not everyone who has numbness or tingling in their hands has CTS. Among the 3,000 people surveyed for the Swedish study, about 14 percent reported CTS-like symptoms. But only one in five of these people was deemed to have CTS, based on physical examination and electrodiagnostic testing.

One or several of these signs or tests may help make the diagnosis:

• Phalen’s maneuver. Your physician will ask you to place your elbow on a table top with your arm and hand in an upright position. He or she will then ask you to flex your hand at your wrist joint and hold it in that position for about one minute. If this test causes your symptoms to appear, it helps confirm a diagnosis of CTS.

• Tinel’s sign. Your physician will tap lightly on your wrist over the median nerve. If the tapping makes your fingers tingle, carpal tunnel syndrome could be the reason.

• Electrodiagnostic test. This test consists of a nerve conduction velocity (NCV) study and electromyography (EMG). The nerve conduction velocity test measures the nerve’s ability to send electrical impulses. It can accurately determine if these impulses are slowed as they travel through your carpal tunnel, denoting a nerve block in that area. Electromyography analyzes the different electrical potentials produced by the different muscles supplied by the median nerve. NCV/EMG studies can pinpoint the exact segment of the affected nerve in the carpal tunnel and the severity of the nerve damage.

Prevention

Here is how to avoid CTS at home and at work:

• When working with your hands, keep your wrists straight. Flexing and twisting them stress the carpal tunnel.

• Lift objects with your whole hand – or better yet, with both hands – to reduce stress on the wrist.

• Make sure your work station is comfortable. If you’re working at a computer keyboard, your fingers should be lower than your wrists. Don’t rest the heel of your hands on the keyboard.

• Take breaks frequently when working with your hands. Working too rapidly may contribute to the problem.

• Type with a soft touch. Don’t pound the keys.

• If your hand hurts while you’re on the rowing machine, for instance, or while playing racquet sports, ease up. Pain is always a signal to stop. If you carry hand weights while running or exercising, make sure they aren’t too heavy.

• If the work you do is stressing your hands, see if you can rotate tasks or share work with someone else.

Treatment Options

The syndrome is much easier to treat and much less likely to cause long-term problems if you diagnose it early. And if you’re diagnosed with carpal tunnel syndrome, a first step in treating the condition is for you to stop doing the activities that aggravate your symptoms. Sometimes, you may only need to stop for a brief period of time.

In addition, here are several methods of managing carpal tunnel syndrome:

• Splinting. You can find relief from minor symptoms of CTS by wearing a lightweight, molded plastic splint that supports your hand and wrist in a neutral position for about two to three weeks. At that time, your physician will reassess your condition. Some physicians recommend wearing the splint at all times. Other doctors find that many people achieve satisfactory results from wearing their splint only at night.

• Non-steroidal anti-inflammatory drugs (NSAIDs). This class of medications can decrease inflammation enough to eliminate symptoms for some people.

• Physical therapy. Local heat application, ultrasound, and transcutaneous electrical nerve stimulation (TENS) may block nerve pathways and can relieve persistent pain and discomfort. Exercises can also improve strength and flexibility which can help restore normal function of the hand and wrist. Here’s a simple exercise that may help:

1. Extend and stretch both wrists and fingers fully as if in a handstand position. Hold for a count of five.

2. Straighten both wrists and relax the fingers.

3. Make a tight fist with both hands.

4. With fists still clenched, bend both wrists down. Hold for a count of five.

5. Straighten both wrists and relax fingers, for a count of five.

6. Repeat this sequence 10 times.

• Steroid injections. More severe cases are often treated by injecting steroid into or near the carpal tunnel. A study in the October 2, 1999 issue of the British Medical Journal offers further support for this practice, with 23 of 30 patients who received a steroid injection improving significantly at the end of one month. Other physicians, however, caution that the injections aren’t risk-free, since there’s a chance the doctor could accidentally hit the nerve with the needle, causing further damage. And besides, there are earlier studies which suggest that up to two-thirds of people who receive steroid injections will eventually end up needing surgery.

• Surgery. For the operation, the surgeon snips the ligament that forms the roof of the carpal tunnel to relieve pressure on the median nerve. This can be done with local anesthesia and doesn’t usually require an overnight hospital stay. Overall, it’s very effective – about 90 percent of people had improved after 18 months, as reported in a recent study published in the Archives of Surgery.

But for many patients with carpal tunnel syndrome, surgery may never be necessary if they talk to their doctor early, at the onset of their symptoms, and take the necessary corrective action.