The usefulness of the Phalen test and the Hoffmann-Tinel sign in the diagnosis of carpal tunnel syndrome.

Both the Phalen test and the percussion (Hoffmann-Tinel) test are considered to be the classic diagnostic tests for Carpal Tunnel Syndrome (CTS). Sensitivity of these tests, as given in the literature, ranges from 42 to 85% (Phalen) and from 38 to 100% (Hoffmann-Tinel), and specificity from 54 to 98% and from 55 to 100% respectively. The objective of this study was to evaluate sensitivity and specificity of both tests and to analyse the influence of such selected factors, such as patient's age and duration of symptoms. The clinical group consisted of 112 patients (147 hands) with CTS confirmed clinically and on nerve conduction studies. The control group of 50 patients (100 hands) was selected from hospital volunteers, who did not complain of any hand symptoms. Sensitivity and specificity of the Phalen test turned out to be respectively 85 and 89% and for the percussion test, 67 and 68%. There was no significant influence of patients' age upon the test results. Seventeen patients showed negative results for both tests, but in these individuals, the duration of symptoms was significantly longer than in the remaining group. These findings indicated essential diagnostic value for the Phalen test, but considerably smaller for the percussion test. In the diagnosis of long lasting syndromes, the usefulness of both tests is limited.