Description: Reversible conduction block due to moderate pressure on the nerve.
Impact: No damage to axons or endoneural sheaths.
Recovery: Spontaneously recovers in 1-4 weeks.
2. Wallerian Degeneration
a. Axonotmesis
Description: Degeneration of nerve axons with intact endoneural sheaths.
Regeneration: Axons regrow at 1mm/day.
Recovery: Spontaneous recovery in about 2-3 months, may be incomplete.
b. Neurotmesis
Description: Degeneration of both axon and endoneural sheaths.
Consequences: Regenerating axons become misaligned, causing synkinesis (e.g., mouth movement with eye closure) and crocodile tears (lacrimation during eating).
Recovery: Clinical improvement begins in 3-4 months, usually incomplete.
Note: Complete transection of the nerve, including the epineurial sheath, is severe with limited hope for useful regeneration unless the nerve ends are properly approximated.
