Grade VI classification describes mixed degrees within a single nerve trunk.
Cable Pathology Probe
Identify the degree of nerve injury from Bruising (Neuropraxia) to complete severance (Neurotmesis) to determine surgical necessity.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Classifying peripheral nerve trauma based on clinical exam and intraoperative nerve conduction.
Deciding between conservative observation, neurolysis, or nerve grafting.
Section 2
Literature
Development
Sir Sydney Sunderland expanded Seddon's original 3-tier classification (Neuropraxia, Axonotmesis, Neurotmesis) into 5 degrees based precisely on which connective tissue layers are breached. In 1989, Dr. Susan Mackinnon introduced the 6th degree (a mixed injury) because real-life nerve trauma (like a jagged glass cut) often spares some fascicles while completely severing others in the same nerve.
Section 3
Pearls/Pitfalls
The Grade VI Strategy
In a Degree VI injury, the surgeon must map the fascicles intraoperatively. The functioning fascicles (Degrees I-III) are painstakingly separated out (internal neurolysis) and spared, while the destroyed fascicles (Degrees IV-V) are resected and grafted.
