Axonotmesis is a traumatic injury to a peripheral nerve involving transection of the axon. The myelin sheath formed by Schwann cells is also damaged; however, crucially, the continuity of the nerve’s connective tissue sheaths is preserved. Because the axon has been interrupted, Wallerian degeneration initially occurs. The proximal axonal stump forms a growth cone and grows along the preserved endoneurial sheath.
Prognosis
If regeneration is successful, substantial restoration of function is likely.
Classification
Axonotmesis corresponds to a grade 2 or 3 peripheral nerve lesion according to the Sunderland classification.