Failure to finger carpal tunnel syndrome.

Failure to finger carpal tunnel syndrome 

Sensations of pain, numbness and tingling in the hand and fingers raise the hint of carpal tunnel syndrome, a disorder caused by compression of the median nerve that runs through the wrist, palm and fingers. But two recent reports raise questions about the validity of certain diagnostic tests physicians commonly use to identify people with carpal tunnel syndrome.

In the first report, Jeffrey N. Katz of the Harvard Medical School and colleagues studied 110 people referred to the Brigham and Women's Hospital for evaluation of hand pain. The Boston researchers gave study participants a variety of diagnostic tests, including one called Tinel sign, in which physicians drop a small reflex hammer five times on the wrist and record whether the patient feels pain in at least one finger innervated by the median nerve. The team compared the results of those initial screening tests with findings obtained by nerve conduction testing, which accurately identifies more than 90 percent of carpal tunnel syndrome cases. Their report in the March 1 ANNALS OF INTERNAL MEDICINE shows the diagnostic screens were of limited value when used alone to find cases of carpal tunnel syndrome, which is thought to result from repetitive movements of the hand and wrist.

A second report, by researchers at the University of Limburg in the Netherlands, shows Tinel sign and 11 other diagnostic screening tests failed to reliably identify carpal tunnel syndrome when measured against a positive nerve conduction test. M. de Krom and his team conclude in the Feb. 17 LANCET that physicians should send patients with suspected carpal tunnel syndrome directly to the nerve conduction laboratory.

But Katz says combinations of screening tests can help avoid costly nerve conduction studies for certain people with hand pain. His study shows people younger than 40 who have a negative Tinel sign and "hand pain diagram" are at low risk of carpal tunnel syndrome.