Ulnar Nerve Entrapment

Ulnar Nerve Entrapment

Question 1. Give the effects of injury to the posterior interosseous nerve.
Answer.

The posterior interosseous nerve supplies all the muscles on the back of the forearm except the anconeus, brachioradialis, and extensor carpi radialis longus.

The posterior interosseous nerve is commonly injured in the fracture or dislocation of the head of the radius.

Posterior Interosseous Nerve Effects

• Paralysis of all the muscles on the back of the forearm except extensor carpi radialis longus, brachioradialis, and anconeus (which are supplied by the radial nerve directly).
• There is no wrist drop because the extensor carpi radialis longus, being a powerful muscle, keeps the wrist joint extended.

ulnar nerve entrapment

Question 2. Write a short note on carpal tunnel syndrome.
Answer.

It occurs due to compression of the median nerve in the carpal tunnel. The carpal tunnel is an osseofibrous tunnel formed by the anterior concavity of the corpus bridged by the flexor retinaculum. This tunnel is tightly packed with long flexor tendons of the fingers, with their surrounding synovial sheaths and the median nerve.

cubital tunnel syndrome

Carpal Tunnel Syndrome Clinical Features

• Painful paraesthesia (i.e., burning pain or pins and needles) along the distribution of the median nerve to the palm and lateral 3½ fingers.
• Weakness and wasting of the thenar muscles.
• No paraesthesia over the skin of the thenar eminence because this area of skin is supplied by the palmar cutaneous branch of the median nerve, which arises in the forearm proximal to the flexor retinaculum.
• It is more frequent in women than in men.
• Intermittent attacks of pain are more common at night.