- See:
Nerve Repair:
- Discussion:
- most severe nerve injury;
- complete disruption of axons, endoneurium, perineurium, & epineurium;
-
Wallerian degeneration occurs;
- recovery requires operative repair and the prognosis is variable, ranging from complete recovery to no recovery;
- factors that influence the degree of recovery;
- the age of the patient
- type of injury
- degree of injury
- level of injury
- if an injury causes division of the nerve close to the cell body, cell death occurs;
- presence of associated injury
- composition of the severed nerve trunk
- if axonal regeneration into the empty endoneural sheaths is delayed, these sheaths
undergo shrinkage that becomes more severe with time;
- nerve injury results in changes within the cell body, the axon proximal & distal to site of injury, and the functional unit innervated;
- more proximal the injury, the greater the cell body damage, as evidenced by changes in the size and internal organization;
- after injury, the cell body progressively enlarges for approx 20 days and remains enlarged until axon regeneration is complete;
- proximal nerve stump swells in response to the accumulation of gel like, amorphous substance containing large
quantities of acid mucopolysaccaride;
- schwan cells begin proliferating 48 to 72 hours after injuries and assume a phagocytic role (Wallerian degeneration);
Long-term follow-up evaluation of cold sensitivity following nerve injury.
