Carpal Tunnel Syndrome

Presentation

The patient complains of pain, tingling, or a “pins and needles” sensation in the hand(s) or fingers. There may be the sensation of swelling or tightness in the absence of edema in the affected hand(s) as well as the sensation of extreme temperature. Onset may have been abrupt or gradual, but the problem is most noticeable after extended use of the hand or when driving or holding up reading material. There may be decreased grip strength, resulting in loss of dexterity, and patients may complain of dropping things and having difficulty with opening jars. Symptoms are usually worse at night and commonly awaken the patient. Sports such as racquetball and handball or activities such as assembly-line work and use of vibratory tools (e.g., jackhammers) are frequently associated with carpal tunnel syndrome (CTS). CTS has also been associated with a number of systemic conditions, including rheumatoid arthritis, sarcoidosis, multiple myeloma, leukemia, diabetes, hypothyroidism, acromegaly, gout, renal failure, obesity, pregnancy, and menopause. The dominant hand can be affected initially but the uncomfortable sensation is often bilateral, may include pain in the wrist or forearm, and, is usually ascribed to the entire hand until specific physical examination localizes it to the median nerve distribution (thumb, index, and middle finger on the palmar side). Strenuous use of the hand almost always aggravates the symptoms. To relieve the symptoms, patients often flick the wrist as if shaking down a thermometer (flick sign). More established cases may include weakness of the thumb and atrophy of the thenar eminence. Although one hand typically has more severe symptoms, as previously mentioned, both hands are often affected.

Physical examination localizes paresthesia and decreased sensation to the median nerve distribution (which may vary) ( Fig. 101.1 ). Motor weakness, if present, is localized to intrinsic muscles with median innervation. Innervation varies widely, but the muscles most reliably innervated by the median nerve are the abductors and opponens of the thumb ( Fig. 101.2 ). CTS typically occurs after 30 years of age and is three times more common in women than in men.