Peripheral nerve injury

Peripheral nerve damage is categorized in the Seddon classification based on the extent of damage to both the nerve and the surrounding connective tissue since the nervous system is characterized by the dependence of neurons on their supporting glia. Unlike in the central nervous system, regeneration in the peripheral nervous system is possible. The processes that occur in peripheral regeneration can be divided into the following major events: Wallerian degeneration, axon regeneration/growth, and nerve reinnervation. The events that occur in peripheral regeneration occur with respect to the axis of the nerve injury. The proximal stump refers to the end of the injured neuron that is still attached to the neuron cell body; it is the part that regenerates. The distal stump refers to the end of the injured neuron that is still attached to the end of the axon; it is the part that will degenerate but remains the area that the regenerating axon grows toward. The study of peripheral nerve injury began during the American Civil War and has expanded to not only include extensive characterization of the processes and factors that contribute to nerve regeneration and reinnervation, but also determine therapies that enhance nerve regeneration such as biological conduits and the administration of growth-promoting molecules.