Which nerve is affected in Carpal Tunnel syndrome?

Which nerve is affected in Carpal Tunnel syndrome?

• A. Median Nerve
• B. Ulnar Nerve
• C. Radial Nerve
• D. Axillary Nerve

Answer: (A)

Carpal tunnel syndrome happens when the median nerve is compressed as it passes through the carpal tunnel in the wrist. The tunnel is formed by the carpal bones and the flexor retinaculum, and the median nerve travels with several finger flexor tendons there. When this nerve is compressed, the symptoms appear in the areas it supplies: numbness or tingling in the thumb, index, middle, and the radial side of the ring finger, and weakness of the thumb muscles that control opposition (the thenar muscles). The palmar skin sensation can be affected in those digits, though the median nerve sends a branch (the palmar cutaneous) before entering the tunnel, so some palm sensation may be spared. The other nerves listed do not pass through the carpal tunnel. The ulnar nerve goes through a different passage (Guyon’s canal) at the wrist and mainly handles the little finger side of the hand and most intrinsic hand muscles. The radial nerve supplies the back of the hand and the extensor muscles of the forearm, not the carpal tunnel. The axillary nerve is in the shoulder region, innervating the deltoid and teres minor.

Carpal tunnel syndrome happens when the median nerve is compressed as it passes through the carpal tunnel in the wrist. The tunnel is formed by the carpal bones and the flexor retinaculum, and the median nerve travels with several finger flexor tendons there. When this nerve is compressed, the symptoms appear in the areas it supplies: numbness or tingling in the thumb, index, middle, and the radial side of the ring finger, and weakness of the thumb muscles that control opposition (the thenar muscles). The palmar skin sensation can be affected in those digits, though the median nerve sends a branch (the palmar cutaneous) before entering the tunnel, so some palm sensation may be spared.

The other nerves listed do not pass through the carpal tunnel. The ulnar nerve goes through a different passage (Guyon’s canal) at the wrist and mainly handles the little finger side of the hand and most intrinsic hand muscles. The radial nerve supplies the back of the hand and the extensor muscles of the forearm, not the carpal tunnel. The axillary nerve is in the shoulder region, innervating the deltoid and teres minor.