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Essentials of Diagnosis
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Pain, burning, and tingling in the distribution of the median nerve
Initially, most bothersome during sleep
Late weakness or atrophy, especially of the thenar eminence
Can be caused by repetitive activities using the wrist
Commonly seen during pregnancy and in patients with diabetes mellitus or rheumatoid arthritis
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General Considerations
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May occur due to fluid retention of pregnancy, in individuals with a history of repetitive use of the hands, or following injuries of the wrists
Caused by compression of the median nerve between the carpal ligament and other structures within the carpal tunnel
The contents of the tunnel can be compressed by
Synovitis of the tendon sheaths or carpal joints
Recent or malhealed fractures
Tumors
Tissue infiltration
Congenital syndromes (eg, mucopolysaccharidoses)
There is a familial type in which no etiologic factor can be identified
Can also be a feature of many systemic diseases, such as
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Pain, burning, and tingling in the distribution of the median nerve; it is most bothersome at night
A Tinel or Phalen sign may be positive (eTable 41–2)
A Tinel sign is tingling or shock-like pain on volar wrist percussion
The Phalen sign is pain or paresthesia in the distribution of the median nerve when the patient flexes both wrists to 90 degrees for 60 seconds
The carpal compression test, in which numbness and tingling are induced by the direct application of pressure over the carpal tunnel, may be more sensitive and specific than the Tinel and Phalen tests (eTable 41–2)
Muscle weakness or atrophy, especially of the thenar eminence, can appear later than sensory disturbances as compression of the nerve worsens
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