[Histology and elementary pathology of the peripheral nerve]

The lesions which give rise to peripheral neuropathy are induced by a variety of mechanisms. Their etiology can often be established from the results of electrophysiological examination and (or) study of nerve biopsy; knowledge of the etiology will guide the treatment strategy. In this chapter, we discuss typical lesional mechanisms including: axonal involvement (Wallerian degeneration, axonopathies) and demyelinating lesions (whether segmental, indicative of an acquired inflammatory process, or of a more extensive nature, indicative of a genetic origin). The indication for nerve biopsy, which enables identification of the lesions, should be considered on a case by case basis.