Neurotmesis

The neurotmesis is a traumatic injury to a peripheral nerve, in addition to the axon ( axonotmesis ) the myelin sheath and the connective tissue accompanying structures ( perineurium, epineurium ) are more or less severed. The axon disintegrates distally of the lesion site in the meaning of the Wallerian degeneration, while the proximal axon growth cones and truncated forms an attempted vorzuwachsen again in the innervation.

Demarcation

From neurotmesis the lighter Läsionsformen of neurapraxia and axonotmesis be differentiated according to the Herbert Seddon (1903-1977) coined classification.

Note: The axons are surrounded by endoneurium and combined to form a fascicle. Several fascicles are grouped together by the perineurium to the actual nerve. The nerve itself is surrounded by an epineurium.

The targeted operational transection of a nerve (without loss of substance ) or neurectomy called neurotomy ( with loss of substance ).

Forecast

The prognosis depends on the degree of injury. While a neurapraxia usually healed without consequences after a few weeks, it comes at the axonotmesis only after a few months to a regeneration, the most complete but ( restitutio ad integrum ). In Neuronotmesis grade 3 there is an incomplete regeneration, which occurs at a rate of about 1-3 mm / day. In higher-grade lesions (such as grade 4 and 5) forms a scar tissue ( Kontinuitätsneurom ), which permits no or only a very poor recovery. Therefore there is a surgical indication. In particular, in grade 5 (ie, the complete transection of all nerve structures) can only be a nerve suture have a view of recovery of neurological function. The nerve stumps are not brought close, then a Nerveninterponat be used, ie There are other nerve fibers in nerve transplantation into the gap, so the defect is bridged.