Neurotmesis

Question 1

Initial injury - complete nerve disruption

Answer 1

Cause - severe trauma

Axons & connective tissue are completely disrupted
Transmit signals immediately lost unless repaired

Question 2

Wallerian degeneration

Answer 2

The nerve distal to the injury starts to degenerate 24-48 hours after injury
Macrophages and Schwann cell clears axon and myelin debris

Question 3

Proximal axonal reaction

Answer 3

The nerve cell body undergoes Chromatolysis
Axonal sprouts form at proximal stump, growth is uncoordinated due to lack of guiding framework

Question 4

Fibrosis and scar tissue formation

Answer 4

Without surgery, the severed nerve ends retract, forming scar tissue
Scar tissue impedes axonal regrowth = neuroma

Question 5

Failure of spontaneous regeneration

Answer 5

Axons fails to reconnect with their distal targets (muscle, organs)
Permanent function loss without surgery

Question 6

What is it?

Answer 6

Neurotmesis is the most severe type of nerve injury, involving complete disruption of the nerve, including both the axon and its surrounding connective tissue structures (endoneurium, perineurium, and sometimes epineurium). This results in total loss of nerve conduction and function below the injury site. Unlike neuropraxia and axonotmesis, neurotmesis has limited potential for spontaneous recovery without surgical intervention due to the disconnection of the nerve fibers and disruption of the guiding framework for regeneration.