Which is the mildest form of traumatic peripheral nerve injury?

• A. Axonotmesis
• B. Neurotmesis
• C. Neuropraxia
• D. Demyelinating neuropathy

Answer: (C)

The main idea is that the mildest traumatic peripheral nerve injury is a temporary conduction block without actual nerve fiber damage. This is Neuropraxia. In this scenario, the myelin sheath is briefly impaired—usually from compression or blunt trauma—so nerve signals can’t get through right away, but the axon itself and the surrounding connective tissue stay intact. Because the axon isn’t damaged, there’s no Wallerian degeneration, and function typically returns as the myelin recovers, often within days to a few weeks.

In contrast, when the axon itself is damaged while the surrounding connective tissue is still largely preserved, you have an axonotmesis. Recovery is possible because the axon can regrow along intact endoneurial tubes, but it’s slower and longer, and there may be some residual deficits. If the nerve is completely severed, as in neurotmesis, recovery without surgical repair is unlikely. Demyelinating neuropathy represents a disease process affecting myelin not necessarily caused by traumatic injury, so it isn’t categorized as a traumatic nerve injury.