What is Carpal tunnel syndrome?

• A. A condition where the median nerve becomes constricted as it runs from the forearm into the palm.
• B. A condition where the radial nerve becomes compressed at the wrist.
• C. A condition of shoulder impingement.
• D. An inflammatory arthritis of the fingers.

Answer: (A)

Carpal tunnel syndrome happens when the median nerve is compressed as it passes through the carpal tunnel at the wrist. The tunnel is formed by the carpal bones on the bottom and the transverse carpal ligament on top, and the median nerve plus several flexor tendons travel through it. When pressure builds in this narrow space, the nerve’s function is disrupted, leading to numbness, tingling, and sometimes weakness in the areas served by the median nerve.

The description in the correct option aligns with this anatomy and mechanism: compression of the median nerve as it moves from the forearm into the hand through the carpal tunnel. That is the defining feature of carpal tunnel syndrome.

Other choices describe different problems that don’t fit the typical nerve compression at the wrist. Compression of the radial nerve at the wrist would affect different areas of the hand, often the dorsal side, and isn’t the median nerve distribution. Shoulder impingement is a problem of the shoulder joint, not the wrist. Inflammatory arthritis of the fingers involves joint inflammation and swelling rather than nerve compression.

Clinically, you’d expect paresthesias in the thumb, index, middle, and radial half of the ring finger, often worse at night, with possible thenar weakness if it’s advanced. Management ranges from splinting and activity modification to injections or surgical release if conservative measures fail or nerve testing is abnormal.