Steroid shot can ease carpal tunnel syndrome pain

By Amy Norton

NEW YORK (Reuters Health) - A single corticosteroid injection in the wrist can bring temporary relief from the pain of carpal tunnel syndrome, a new research review suggests.

Carpal tunnel syndrome (CTS) is caused by pressure on the median nerve, which runs through a narrow passageway in the wrist -- the carpal tunnel. Symptoms include pain, numbness and weakness in the hand, fingers and wrist. In severe cases, a permanent loss of feeling or partial paralysis may occur.

Inflammation in nearby soft tissue is often the source of pressure on the median nerve, and injections of anti-inflammatory corticosteroids are sometimes used to treat CTS. However, there's been relatively little research into how well the therapy works.

For the new study, researchers, led by Dr. Shawn Marshall of the University of Ottawa in Canada, identified 12 published studies that tested corticosteroid injections for CTS. Overall, they found that a single steroid shot was more effective than a placebo at relieving patients' symptoms for one month.

There wasn't much evidence of a longer-term benefit, however. One study suggested that the symptom relief can last for 6 months, but another found that, over 8 weeks, the shots were no better than oral anti-inflammatory medications or wrist splints at improving CTS symptoms.

The findings appear in the Cochrane Library, which is published by the Cochrane Collaboration, an international organization that evaluates medical research.

"Our study conclusions suggest that benefit beyond 1 month is not assured," Marshall told Reuters Health. Nor is it clear which people with CTS are the best candidates for corticosteroid injections, according to the researcher.

For now, he said, people with moderate symptoms could try the therapy, as could those with severe symptoms who do not want surgery. People who are awaiting surgery could also try an injection for some temporary relief, Marshall added.