A familial syndrome of constrictive median neuropathy
caused by enlarged tendons and/or ligaments in the wrist, often resulting
Thenar Amyotrophy of Carpal Origin; Constrictive Median
Autosomal dominant. A high degree of
penetrance within affected families has been described. Genetic linkage
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.
David WS, Chaudhry V, Dubin AH, et al: Literature review: NervePace
digital electroneurometer in the diagnosis of carpal tunnel syndrome.
Gossett JG, Chance PF: Is there a familial carpal tunnel syndrome? An
evaluation and literature review. Muscle Nerve