Axonotmesis

Axonotmesis is a disruption of nerve cell axon, with Wallerian degeneration occurring below and slightly proximal to the site of injury. If axons and their myelin sheath are damaged, but Schwann cells, the endoneurium, perineurium and epineurium remain intact, it is called axonotmesis. Axonotmesis is usually the result of a more severe crush or contusion than neuropraxia. In axonotmesis, the proximal section is repaired by creating a sprout with its growth cone, but in the distal section occurs axonal degeneration. The rate of outgrowth of regenerating nerve fibers is about 1 mm to 2 mm per day, so that the recovery of conduction to a target structure depends on not only regrowth into the appropriate endoneurial tube (endoneurium), but also on the distance involved.