Diagnostic Clinical Criteria of Carpal Tunnel Syndrome*

Question

Answer

The "carpal tunnel" consists of 9 tendons (Flexor Pollicis Longus, 4 tendons of the Flexor Digitorum Profundus and 4 tendons of the Flexor Digitorum Superficialis) and the median nerve.  Due to the small space that these structures run through, they are prone to irritation.  In fact, during composite finger flexion, these structures undergo changes:

• Flattening/displacement of the median nerve
• Proximal migration of the lumbricals
• Pressure on FDP and FDS tendons

As a result of these structural changes, Carpal Tunnel Syndrome (CTS) can occur.  The six diagnostic clinical criteria of CTS are:

1. Numbness and tingling in the median nerve distribution (thumb, index and middle finger).
2. Nocturnal numbness or exacerbation of symptoms at night
3. Weakness or atrophy of the thenar musculature
4. Tinel sign (Tapping on nerve produces symptoms.)
5. Phalen's test (Hyperextending wrists with both hands together produces the symptoms.)
6. Loss of 2 point discrimination

Research shows that the best CTS management strategies is splinting the wrist in neutral/slight flexion with slight ulnar deviation and the MPs in neutral in combination with lumbrical stretches.  Ultrasound and neural flossing have found to be helpful.  Activity modification such as performing activities with a neutral wrist position and 45 degrees of forearm rotation has also found to decrease the symptoms.