Peripheral Nerve Injury

The peripheral nervous system (PNS) consists of nerves and ganglia outside of brain and spinal cord. Unlike the central nervous system, the peripheral nerves show an intrinsic capability for regeneration post injury, although limited [3]. The functional unit of the PNS, the neuron consisting of a body, its processes, dendrites and an axon, has no ability to undergo cell division. The neuroglia, however, can undergo mitotic division, especially in response to trauma.
Peripheral nerve injury is classified into five types – first-degree (neurapraxia), second-degree (axonotmesis), third-degree, fourth degree and fifth-degree. Neurapraxia is the mildest type in which there is a temporary loss of conduction without loss of axonal continuity. Axonotmesis