Which nerve injury is characterized by temporary motor loss from compression or blunt trauma and is the most common?

• A. Axonotmesis
• B. Neuropraxia
• C. Neurotmesis
• D. Palsy

Answer: (B)

Neuropraxia is a temporary blockage of nerve conduction caused by compression or a blunt impact. In this scenario the nerve fibers themselves stay intact, so there’s no axonal damage or Wallerian degeneration. Because the conduction block is reversible, motor function often returns quickly once the pressure or trauma is removed—usually within days to weeks. This pattern—temporary loss without structural nerve injury—makes it the most common nerve injury seen with these mechanisms, such as transiently impaired motor function after a blunt hit or brief compression.

Axonotmesis involves actual disruption of the axon with preservation of the surrounding connective tissue; recovery occurs by axonal regrowth and is slower, and some distal degeneration occurs. Neurotmesis is a complete severance of the nerve, with poor natural recovery without surgical repair. A general term like palsy describes paralysis but does not specify the nerve injury mechanism or prognosis.