Neurotmesis

Neurotmesis is part of Seddon's classification scheme used to classify nerve damage. Neurotmesis is the most severe lesion with potential of recovering. It occurs on severe contusion, stretch, laceration, or Local Anesthetic Toxicity. Not only the axon, but the encapsulating connective tissue lose their continuity. The last (extreme) degree of neurotmesis is transsection, but most neurotmetic injuries do not produce gross loss of continuity of the nerve but rather internal disruption of the architecture of the nerve sufficient to involve perineurium and endoneuruim as well as axons and their covering. Denervation changes recorded by EMG are the same as those seen with axonotmetic injury. There is a complete loss of motor, sensory and autonomic function. If the nerve has been completely divided, axonal regeneration causes a neuroma to form in the proximal stump. For neurotmesis, it is better to use a new more complete classification called the Sunderland System.