20250131 Nerve injury Dr Izzuddin

A 55-year-old male laborer comes in with a chief complaint of clumsiness with his right hand for the past 3 months including difficulty using a hammer while at work. He has had no injury to the right upper extremity. On physical examination, he has persistent small finger abduction/extension with finger extension and active adduction. An EMG is performed and demonstrates ulnar nerve conduction velocities of 31 m/sec (normal >52m/sec). The patient symptoms are most accurately described as:

• A. Axonotmesis with ischemia origin

• B. Axonotmesis with myelin disruption

• C. Neurapraxia with ischemia origin

• D. Neurapraxia with endoneurium disruption

• E. Neurotmesis

The patient sustains the injury seen in Figure A from a gunshot injury. The physical exam is notable for lack of sensation in his fourth and fifth digits as well as a positive Froment's sign. Which of the following factors has not been shown to be a significant prognostic indicator of functional recovery following nerve repair?

• A. Duration to time of repair

• B. Repair level

• C. Length of repair

• D. Postoperative physical rehabilitation

• E. Type of autograft used

Which of the following nerves has the most favorable regenerative potential in restoring motor function after a graft repair within half a year after being injured?

• A. Median

• B. Ulnar

• C. Radial

• D. Tibial

• E. Peroneal

Axon regeneration almost always occurs following a Sunderland second-degree nerve injury because which anatomic structure is not injured?

• A. Epineurium

• B. Endoneurium

• C. Perineurium

• D. Myelin sheath

• E. Schwann cell

Which of the following peripheral nerve structures functions to cushion the nerve against external pressure?

• A. Endoneurium

• B. Fibronectin

• C. N-cadherin

• D. Epineurium

• E. Perineurium