Diagnosis of Carpal Tunnel Syndrome
Early diagnosis and treatment are very important to avoid permanent damage to the median nerve and tendons in Carpal Tunnel Syndrome(CTS). Physical examination of the hands, arms, shoulders, and neck helps determine whether the patient's complaints are related to daily activities or to any underlying disorder. The wrist is examined for physical changes like tenderness, swelling, warmth, and discoloration. Each finger should be tested for sensation. The muscles should be examined for strength and signs of atrophy. Routine laboratory tests and X-rays reveal underlying cause like diabetes, arthritis, and fractures.
Doctors might ask patients to try and make a movement that brings on symptoms.
Clinical findings that are positive in CTS are:
- Wasting of thenar eminence
- Weakness in palm abduction and thumb supination movements
- Weakness of opponens pollicis muscle
- Skin examination might result:
- Ulcerative, necrotic or bullous lesions
- Digital anhydrosis, alopecia, nail change (rare)
To confirm the diagnosis, at times it's important to check the functioning of median nerve by use of electro diagnostic tests. In a nerve conduction study, electrodes are placed on the hand and wrist and the speed with which nerves transmit impulses is measured. In electromyography, a fine needle is inserted into muscle and the electrical activity is viewed on the screen to determine the severity of damage to median nerve. Two common tests that confirm the presence of carpel tunnel syndrome are called Tinel's and Phalen's Test.
- Tinel's Sign - Tinel's Sign is elicited by tapping the median nerve along its course in the wrist, the worsening of symptoms are checked for. A positive test is found when tapping causes worsening of the tingling sensation in the fingers when the nerve is tapped.
- Phalen's Sign - Phalen's test is done by joining the back of hands and pushing the back of hands together for one minute. This compresses the carpal tunnel. Positive test reflects when this causes worsening of symptoms.