Which type of nerve injury is considered the most severe, with complete nerve division?

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

Answer: (C)

When a nerve is completely severed, the continuity of both the axon and its supporting connective tissue is lost, so spontaneous reinnervation across the injury site is unlikely without surgical repair. This full disruption is called neurotmesis, and it carries the poorest natural prognosis because regrowth cannot effectively bridge the gap on its own. Recovery, if any, typically depends on surgical realignment and possible grafting to restore function.

By comparison, neuropraxia is a temporary conduction block with the nerve's axons intact, so function returns quickly once the block heals. Axonotmesis involves axonal damage but preserves the surrounding endoneurial tubes, allowing potential regrowth along the original pathway, though it may take time. Demyelinating neuropathies primarily affect the myelin sheath around otherwise intact axons, so recovery hinges on remyelination rather than nerve continuity.