That's the conclusion of a new study from the January issue of the Archives of Physical Medicine and Rehabilitation , which found that wearing a custom-made wrist splint for six weeks could bring long-lasting relief.

"This fairly innocuous, low-cost intervention dramatically improves the level of discomfort, not only in the short-term, but the relief lasts up to a year out," said study author Dr. Robert Werner, the chief of physical medicine and rehabilitation at the Ann Arbor VA Medical Center in Michigan.

Carpal tunnel syndrome is a repetitive stress injury that occurs when the median nerve in the wrist is compressed for long periods of time. This compression can cause permanent nerve damage if left untreated. According to the National Institutes of Health, carpal tunnel syndrome is five times more common in women than in men and most often occurs in people between the ages of 30 and 60.

Conservative treatment options include wrist splints, rest, non-steroidal anti-inflammatory medications (NSAIDs), diuretics, cold laser, vitamin B6 and steroid injections, according to the study.

"Simple treatments like nighttime splits can be useful when you get at it early, but many people don't seek treatment right away, and light carpal tunnel can go for long periods of time, causing permanent nerve injury," said Peter Stevens, a physician's assistant in the orthopedics department at Ochsner Clinic Foundation Hospital in New Orleans.

If simple treatments fail, surgery becomes an option. Werner said that about half the people with carpal tunnel syndrome end up having surgery, which is successful for most. But, he added, surgery is expensive and means a month or so of lost work and discomfort.

One hundred and twelve people working at a Midwestern automotive plant were recruited for the study. The repetitive nature of their work puts auto workers at an increased risk of carpal tunnel syndrome, the researchers said. All of the study participants had early symptoms of the syndrome, including burning, tingling, numbness, and pain in the hand that lasted longer than a week and happened more than three times in the six months before the study.

All of the participants watched a short video about carpal tunnel syndrome that contained tips on reducing the risk of the disorder.

Then, 63 people were fitted with custom-made wrist splints that held their wrist in a neutral position, which meant the median nerve wasn't compressed at all. They were told to wear the splints every night for six weeks. The other 49 received no additional instruction.

After 30 days, the group wearing the splints had almost a 50 percent reduction in symptom severity; the control group had a 15 percent reduction.

The researchers followed up with the study participants again after a year, and many who had used the splints still had improvement in their symptoms.

"This study clearly indicates that if you do nighttime splinting that the discomfort levels are improved," said Werner, who suggested that people can try this at home. He said the splints are available at drugstores and they're a "simple home remedy."

But, he added, if you don't start feeling relief after six weeks, or your symptoms are getting worse, you should seek medical attention.

Werner said that wearing the splints kept the study participants from compressing the median nerve at night because people often sleep with their wrists in strange positions. The splints also allowed the median nerve to rest and begin to repair overnight, he said.

"Early intervention is key," said Heather Turkopp, an occupational therapist and certified hand therapist at William Beaumont Hospital in Royal Oak, Mich. "The longer that nerve is compressed, the more permanent damage you're doing."

She said symptoms to be on the watch for include numbness and tingling in the median nerve area, which includes the thumb, index and middle finger, and sometimes part of the ring finger.

Stevens pointed out the symptoms are often worse at night, and when the wrist is bent, such as holding a book or the telephone.

If you buy splints on your own, Turkopp pointed out that you should make sure the wrist isn't flexed at all. Sometimes, she said, you have to bend the metal support to ensure that the wrist is in a neutral position.

The study was funded by the United Auto Workers-General Motors National Joint Committee on Health and Safety.

SOURCES: Robert Werner, M.D., professor, department of physical medicine and rehabilitation, University of Michigan Health System, and chief, physical medicine and rehabilitation, Ann Arbor VA Medical Center, Ann Arbor, Mich., Peter Stevens, certified physician's assistant, department of orthopedics, Ochsner Clinic Foundation Hospital, New Orleans; Heather Turkopp, occupational therapist and certified hand therapist, William Beaumont Hospital, Royal Oak, Mich.; January 2005 Archives of Physical Medicine and Rehabilitation