Carpal Tunnel Syndrome

Carpal tunnel syndrome is constriction of the median nerve as it passes through the carpal tunnel in the wrist. Symptoms include pain, paresthesias, and weakness, all in the median nerve distribution. Diagnosis is suggested by symptoms and signs and confirmed by nerve conduction velocity testing. Treatments include ergonomic improvements, analgesia, splinting, and sometimes corticosteroid injection or surgery.

Geriatric Essentials

• Carpal tunnel syndrome can be the first manifestation of arthritis in the wrist.
• Elderly patients with carpal tunnel syndrome often present with nerve compression at more than one level (eg, cervical radiculopathy or myelopathy plus carpal tunnel).

Carpal tunnel syndrome is common. Contributing factors in the elderly include RA or other wrist arthritis (sometimes carpal tunnel syndrome is the first manifestation), diabetes mellitus, hypothyroidism, acromegaly, and amyloidosis. Other risk factors include obesity, tobacco use, relying on crutches or a walker, and activities or jobs requiring repetitive wrist flexion and extension. Most cases are idiopathic.

Symptoms and Signs

Symptoms include hand and wrist pain with paresthesia and numbness, characteristically in the median nerve distribution (ie, the palmar side of the thumb, index and middle fingers, and radial half of the ring finger). Typically, the patient wakes at night with burning or aching pain, numbness, and tingling; the patient typically shakes the hand to obtain relief and restore sensation. Hypoalgesia in the median nerve distribution and weak thumb abduction are common and suggestive. Tinel's sign (tingling in the median nerve region is elicited by tapping the palmar surface of the wrist over the median nerve site in the carpal tunnel) and wrist flexion maneuvers, such as Phalen's maneuver (tingling in the median nerve region is elicited by holding the patient's wrist in acute passive flexion for about 1 min), are not specific. Thenar muscle atrophy is a late sign.

Diagnosis

Diagnosis is suggested by clinical findings. Median nerve compression is confirmed by electrodiagnostic testing. Electrodiagnostic evidence of median nerve compression is usually considered the most accurate diagnostic finding but does not always predict the response to treatment.

Paresthesia of the 4th and 5th fingers suggests ulnar nerve compression. Patients that have simultaneous deficits in the distribution of >= 2 hand nerves almost always have compression at the brachial plexus. Elderly patients with carpal tunnel syndrome often present with double-level nerve compression (eg, cervical radiculopathy or myelopathy plus carpal tunnel).

Treatment

For those who use a keyboard frequently, repositioning the keyboard or making other ergonomic corrections may provide relief. Additional treatment includes using a lightweight wrist splint (see Figure 55-4). It is especially important to use the splint at night because of the tendency to hyperextend or flex the wrist when sleeping. Some physicians prescribe pyridoxine (vitamin B₆) 50 mg po bid and mild analgesics (eg, acetaminophen, NSAIDs). If these measures do not control symptoms, a corticosteroid should be locally injected into the carpal tunnel at a site just ulnar to the palmaris longus tendon and proximal to the distal crease at the wrist. If bothersome symptoms persist or recur or if hand weakness and thenar wasting progress, surgical decompression of the carpal tunnel using an open technique or endoscopic approach is recommended.

This topic was last updated May 2006.