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Seddon's and Sunderland's classifications of nerve injuries |
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| Injury |
Pathophysiology |
Exam Findings |
Nerve Studies |
Prognosis |
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| Neurapraxia (Seddon) First Degree (Sunderland) |
Reversible conduction block. Local compression with ischemia; selective demyelination of the axon sheath possible. |
Motor paralysis: complete Muscle atrophy: minimal Sensory alteration: minimal, often with sparing |
Distal nerve conduction: present. Motor unit action potential: absent. Fibrillation: occasionally detectable. |
Good prognosis. Full recovery usually within days to 2–3 weeks |
| Axonotmesis (Seddon) Second Degree (Sunderland) |
More severe injury with disruption of the axon and myelin sheath. |
Motor paralysis: complete Muscle atrophy: progressive Sensory alteration: complete |
Distal nerve conduction: absent. Motor unit action potential: absent. Fibrillation: present. |
Fair prognosis. Full recovery possible without surgery; recovery at 1 mm/day |
| Third Degree (Sunderland) |
Endoneurium disrupted; epineurium and perineurium intact. |
Same |
Same |
Same |
| Fourth Degree (Sunderland) |
Endoneurium and perineurium disrupted; epineurium intact. |
Same |
Same |
Same |
| Neurotmesis (Seddon) Fifth Degree (Sunderland) |
Complete nerve division with disruption of the endoneurium, perineurium, and epineurium. |
Same |
Same |
Poor prognosis. Requires surgery with varying degrees of impairment present even after surgery |
Chandler et al. Patient Safety in Surgery 2007 1:8 doi:10.1186/1754-9493-1-8 |
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