Which finding during the Phalen's test indicates carpal tunnel syndrome?

Which finding during the Phalen's test indicates carpal tunnel syndrome?

• A. Tingling or numbness in the thumb, index and middle fingers
• B. Numbness in the little finger and ring finger
• C. Ring and middle fingers
• D. Tingling or numbness in the thumb, index and middle fingers

Answer: (D)

Phalen's test checks for compression of the median nerve inside the carpal tunnel. When the wrist is flexed, pressure on the median nerve increases, and if CTS is present, symptoms are reproduced in its sensory distribution. The median nerve supplies sensation to the thumb, index finger, and middle finger (and the radial side of the ring finger). Therefore, tingling or numbness in the thumb, index, and middle fingers during the test best indicates carpal tunnel syndrome. Numbness in the little finger and ring finger points to the ulnar nerve, not CTS, and the middle/ring finger pattern alone doesn’t fit the typical median nerve distribution.

Phalen's test checks for compression of the median nerve inside the carpal tunnel. When the wrist is flexed, pressure on the median nerve increases, and if CTS is present, symptoms are reproduced in its sensory distribution. The median nerve supplies sensation to the thumb, index finger, and middle finger (and the radial side of the ring finger). Therefore, tingling or numbness in the thumb, index, and middle fingers during the test best indicates carpal tunnel syndrome. Numbness in the little finger and ring finger points to the ulnar nerve, not CTS, and the middle/ring finger pattern alone doesn’t fit the typical median nerve distribution.