Carpal Tunnel Syndrome

A familial syndrome of constrictive median neuropathy caused by enlarged tendons and/or ligaments in the wrist, often resulting from inflammation.

Thenar Amyotrophy of Carpal Origin; Constrictive Median Neuropathy.

Autosomal dominant. A high degree of penetrance within affected families has been described. Genetic linkage unknown.

Marked, noninflammatory thickening of the transverse carpal ligaments and/or flexor tendon sheaths, digital flexor tenosynovitis, constrictive median neuropathy, associated with thenar atrophy and weakness of the hand. Severe vitamin B6 deficit is associated with this disorder, and supplemental vitamin B6 improves the symptoms in some cases, even obviating surgery.

Early age of onset (usually third decade of life, but much earlier onset has been described) of entrapment neuropathy. Progressive course with need for surgical relief. The clinical course of the entrapment neuropathy is characteristic and includes paresthesia in the distribution of the median nerve, nocturnal aggravation of symptoms, and thenar atrophy and hand weakness in long-standing cases. Electromyography can be used to confirm the diagnosis.

Symptoms may be reproduced by volar wrist percussion (Tinel sign), sustained wrist flexion (Phalen sign), or wrist extension (palmar prayer sign). Occurring in the context of familial aggregation and excluding secondary causes such as trauma, local edema (during pregnancy), tissue infiltration (myxedema, mucopolysaccharidosis, mucolipidosis, sarcoidosis, amyloidosis), or inflammatory tenosynovitis (rheumatoid arthritis, gout, systemic lupus erythematosus). Thickened transverse carpal ligament and digital flexor tenosynovitis are observed. Familial carpal tunnel syndrome is described in related persons suffering from amyloidosis, mucopolysaccharidosis, and mucolipidosis.

Local infiltration, regional anesthesia, and general anesthesia have all been used successfully.