A good night’s rest may do a world of good for the hands and wrists of workers who suffer from painful carpal tunnel syndrome (search).

New research shows that nighttime splinting can significantly reduce hand and wrist pain among employees with carpal tunnel syndrome (CTS) who might otherwise miss work due to their condition.

“Workers with carpal tunnel syndrome have more lost work time than any other work-related injury,” says researcher Robert Werner, MD, chief of physical medicine and rehabilitation at the VA Ann Arbor Healthcare System, in a news release.

“Additionally, CTS is frequently misdiagnosed and there’s very little scientific research to show which initial treatments are actually the most effective for those with symptoms of carpal tunnel syndrome.”

Carpal tunnel syndrome is a common work-related disorder caused by pressure on the median nerve within the wrist. Symptoms include pain, tingling, and numbness from compression of the nerve which innervates the thumb, index, and middle fingers of the hand. The disease can progress and lead to weakness of the muscle of the hand.

Initial treatments for carpal tunnel syndrome include wrist splinting, modification of hand activity, pain medication, diuretics, and steroid injections. These treatments can help reduce inflammation caused by repeated injury to the nerve.

Splinting May Relieve Carpal Tunnel Pain

In the study, which appears in the January issue of the Archives of Physical Medicine and Rehabilitation, researchers evaluated nighttime splinting of the hands and wrists in relieving the symptoms of carpal tunnel in a group of Midwestern automotive assembly plant workers. All of the workers had symptoms consistent with carpal tunnel syndrome, such as persistent numbness, burning, and pain in the median nerve, but had not sought medical treatment for their condition.

About half of the workers were fitted with a custom wrist-hand splint that kept the wrist in a neutral position during sleep. They were instructed to wear the splint at night for six weeks. The treatment group and the remaining participants were also instructed on how to reduce stress on the median nerve at work and watched a 20-minute video on carpal tunnel syndrome.

After six weeks of treatment, about half of those who used the splint reported significant improvement in their carpal tunnel symptoms, and one participant reported complete relief of symptoms. Compared with the nontreatment group, the splinted group also had significantly less hand, wrist, elbow, and forearm discomfort three months later.

The study showed that a year after treatment, the improvement experienced by each group depended largely on the level of nerve damage and initial pain.

Among those who used the splint, those with healthy or injured median nerves who reported higher levels of pain and discomfort at the beginning of the study experienced the greatest improvement. In the nontreated group, those with healthy nerves reported reduced pain but those with injured nerves felt no improvement over time.

Although splinting is one of the most popular initial treatments for carpal tunnel, researchers say that until now there has been little evidence on its effectiveness. They say this study shows it can be an effective initial treatment when symptoms of carpal tunnel first emerge, but it has a minimal effect on those with advanced carpal tunnel.

“Early intervention with splinting is key to effective management of carpal tunnel syndrome,” says Werner. “It’s very cost-effective and the odds are very good that you will feel the benefits.”

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCES: Werner, R. Archives of Physical Medicine and Rehabilitation, January 2005. News release, University of Michigan Health System.