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.
Specialty: Neurology
ICD-10: ,