This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
What is Neurapraxia: September 2010 
Select and explain. 
A. Complete division of nerve, B. Loss of conduction due to axonal interruption, C. Irreversible injury, D. Reversible physiological nerve conduction block
D: Reversible physiological nerve conduction block
Answer: D: Reversible physiological nerve conduction block 
Explanation: Ans. D: Reversible physiological nerve conduction block Neurapraxia is pa of Seddon's classification scheme used to classify nerve damage. It is a transient episode of motor paralysis with little or no sensory or autonomic dysfunction. Neurapraxia describes nerve damage in which there is no disruption of the nerve or its sheath. In this case there is an interruption in conduction of the impulse down the nerve fiber, and recovery takes place without true regeneration, as Wallerian degeneration does not occur. This is the mildest form of nerve injury. This is probably a biochemical lesion caused by concussion or shock-like injuries to the fiber.