Table 1.

Classification of nerve damage

Seddon/Sunderland	Histological changes and responses			Recovery (period)	Treatment
Neurapraxia	I	Transient ischemia, demyelination, intra-bundle edema	Conduction disorder	Reversible (hours to weeks)	Observation
Axonotmesis	II	Damaged axon (intact endoneurium)	Wallerian degeneration	Reversible (weeks)	Observation
	III	Damaged axon, endoneurium (intact perineurium)	Wallerian degeneration	Varies (weeks to months)	Need to check for damage
	IV	Damaged axon, endoneurium, and perineurium (intact epineurium)	Wallerian degeneration, death of neuron, neuroma, fibrosis	Irreversible	Microsurgical reconstruction
Neurotmesis	V	Complete nerve transection	Wallerian degeneration, death of neuron, neuroma, fibrosis	Irreversible	Microsurgical reconstruction