Axonotmesis

Question 1

Initial injury- axon distruption

Answer 1

Cause - Severe compression, traction or crush - axon is damaged not the connective tissue sheath

Axonal continuity is lost, nerve signal are interrupted
Myelin sheath might also be disrupted

Question 2

Wallerian degeneration

Answer 2

Distal part of the axon degenerates with 24-48 hours
Macrophages and Schwann cells remove debris - this clears the way for axonal regeneration

Question 3

Proximal axonal reaction

Answer 3

The nerve cell body undergoes Chromatolysis
Growth factors are produced to promote axonal sprouting

Question 4

Axonal regeneration

Answer 4

Axonal sprouts emerge from the proximal stump
Schwann cells play a critical role by forming regeneration tubes

Question 5

What is it?

Answer 5

Axonotmesis is a moderate form of nerve injury where the axons (nerve fibers) are damaged, but the surrounding connective tissue structures (e.g., endoneurium, perineurium, and epineurium) remain intact. This injury results in loss of nerve function and conduction below the injury site. Unlike neuropraxia, axonotmesis involves Wallerian degeneration of the distal axonal segment. However, since the connective tissue framework is preserved, the nerve has a good potential for regeneration and recovery.