Classification of Seddon for Peripheral Nerve Injury

Seddon described 3 types of nerve injury following trauma. These correlate with the severity of injury and duration of impairment.

Parameters:

(1) severity of injury

(2) duration of impairment

(3) sensory change

(4) nerve conduction

(5) damage

Terms for different types of nerve injury (tmesis = Greek for cut apart or sever):

(1) neurapraxia

(2) axonotmesis

(3) neurotmesis

Parameter	Neurapraxia	Axonotmesis	Neurotmesis
severity	mild	moderate	severe
duration	hours to days	weeks to months	months to forever
sensory change	mild paresthesias	severe paresthesias	anesthesia
nerve conduction	decreased across lesion but normal distal and proximal	decreased across and distal to lesion	none
damage	nerve sheath intact with no axonal loss	axonal degeneration distal	complete disruption
recovery	complete	incomplete	none to limited

where:

• Neurapraxia may be associated with disturbed stimulus interpretation and/or poor discrimination.

• Recovery follow neurotmesis may occur if the damage occurs within a bony canal or if the patient has surgery.

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