Table 1.

Seddon and Sunderland classification of nerve injury.

Seddon's classification	Sunderland's classification	Injured Tissue	Spontaneous recovery	Electromyography
Neurapraxia	Grade I	Myelin	Yes	Normal morphology and poor motor unit action potential recruitment
Axonotmesis	Grade II	Myelin, axon	Yes, slower than neurapraxia	Abnormal activity
Axonotmesis	Grade III	Myelin, axon, endoneurium	Not very likely, surgical intervention may be needed
Axonotmesis	Grade IV	Myelin, axon, endoneurium, perineurium	Highly unlikely, surgical intervention is necessary
Neurotmesis	Grade V	Myelin, axon, endoneurium, perineurium, epineurium	No, surgical intervention is necessary	Abnormal activity