Carpal Tunnel Syndrome

The carpal tunnel is a defined space, bordered by carpal bones on the floor and sides of the wrist, and a thick ligament on top. Through this tunnel, nine flexor tendons and the median nerve course through from the forearm to the digits. If for any reason this compartment or space becomes tight (compressed), median nerve function is compromised and classical symptoms of “Carpal Tunnel Syndrome” become apparent. The cause of the increased pressure within the carpal tunnel is often unknown (idiopathic). Carpal tunnel syndrome has been linked to multiple factors including fluid retention, various medical conditions (diabetes, rheumatoid arthritis, and hypothyroidism), personal attributes (obesity), pregnancy, and wrist and thumb arthritic changes. Certain injuries such as distal radius fractures are also acknowledged causes for an increased chance of developing Carpal Tunnel Syndrome (categorized as “post-traumatic”). It remains unclear if repetitive activities such as typing increase the chance of developing Carpal Tunnel Syndrome.

A diagnosis of Carpal Tunnel Syndrome is established by classical symptoms, physical findings, and may be confirmed with electrodiagnostic studies. Symptoms include tingling (paresthesias) of the fingers predominantly at night; numbness of the thumb, index, middle, and one-half of the ring finger, and weakness of the thumb. Physical findings include sensory changes in the median nerve distribution, weakness or atrophy of the Thenar musculature, and positive provocative tests (such as Tinel’s sign, median nerve compression test, and Phalen’s test) on examination. Electrodiagnostic studies can provide objective evidence of conduction abnormalities of the median nerve at the wrist supporting the presence of Carpal Tunnel Syndrome. Electrodiagnostic studies can also determine if there are other neurological abnormalities, which may mimic symptoms and findings of Carpal Tunnel Syndrome.

Treatment for Carpal Tunnel Syndrome involves simple supportive means, such as cortisone injection, and/or surgical decompression.

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