**Question:** All of the following show ulnar nerve injury EXCEPT

A. Cubital Tunnel Syndrome
B. Radial Nerve Injury
C. Ulnar Nerve Injury at the Elbow
D. Median Nerve Injury

**Core Concept:** The ulnar nerve is a major peripheral nerve that runs through the forearm, providing motor and sensory innervation to the muscles and skin of the ulnar side of the hand. Ulnar nerve injuries can occur in various locations, including the elbow (Cubital Tunnel Syndrome, Ulnar Nerve Injury at the Elbow), wrist (Ulnar Nerve Entrapment), and wrist (Ulnar Nerve Compression or Entrapment). In contrast, radial nerve injuries (A) and median nerve injuries (D) are different nerves supplying the opposite side of the hand.

**Why the Correct Answer is Right:** Option D (Median Nerve Injury) is correct because a median nerve injury would affect the ulnar side of the hand, which is the opposite side of the hand from the ulnar nerve. Median nerve injury would result in motor and sensory deficits in the thumb, index, middle, and half of the ring finger, while ulnar nerve injury would affect the little finger and ulnar two-thirds of the ring finger.

**Why Each Wrong Option is Incorrect:**

A. Cubital Tunnel Syndrome (Cubital Tunnel Syndrome) and Ulnar Nerve Injury at the Elbow (Ulnar Nerve Injury at the Elbow) are both ulnar nerve injuries occurring at the elbow. These conditions affect the same side of the hand as the ulnar nerve injury, making them incorrect options in comparison to median nerve injury.

B. Radial Nerve Injury (Radial Nerve Injury) is a different nerve supplying the opposite side of the hand to the ulnar nerve. Injuries to the radial nerve would result in motor and sensory deficits in the thumb, index, middle, and half of the ring finger, not the ulnar side of the hand.

C. Ulnar Nerve Compression or Entrapment (Ulnar Nerve Compression or Entrapment) is another term for Cubital Tunnel Syndrome or Ulnar Nerve Injury at the Elbow. These conditions are also ulnar nerve injuries occurring at the elbow, making them incorrect options in comparison to median nerve injury.

**Clinical Pearl:** The median nerve is the most common cause of ulnar nerve compression neuropathy, accounting for about 25% of all peripheral nerve injuries. The cubital tunnel syndrome occurs in the elbow due to entrapment of the ulnar nerve as it passes through the cubital tunnel at the medial elbow joint. This can result in symptoms like sensory loss in the ulnar two-thirds of the ring finger and ulnar two-thirds of the little finger, as well as motor weakness in the little finger. Careful clinical examination is necessary to differentiate between a median nerve injury and ulnar nerve injury in the elbow, as they share similar symptoms.