Table 1. Degree of nerve injury and anticipated recovery.

Degree of nerve injury	Definition of nerve injury	Prognosis	Tinel sign	Surgical intervention
First (Neurapraxia)	Segmental demyelination Axonal continuity maintained; endoneurium, perineurium and epineurium, intact	Favorable	None	None, distal decompression
Second (Axonotmesis)	Discontinuity of axon and myelin; endoneurium, perineurium, and epineurium intact	Favorable	Present, progressive	None, distal decompression, supercharge procedure
Third	Discontinuity of axon, myelin and endoneurium; perineurium and epineurium intact	Favorable	Present, progressive	None, distal decompression, supercharge procedure
Fourth	Only the epineurium remains intact	Unfavorable	Present; no progression	Nerve repair, graft, transfer
Fifth (Neurotmesis)	Complete nerve transection	Unfavorable	Present; no progression	Nerve repair, graft, transfer
Sixth	Mixed injury pattern	Variable	Variable	All options may be appropriate