The effects of compression on the physiology of nerve roots.

The spinal roots connect the central and peripheral nervous systems. In doing so, the nerve roots pass through the spinal column, where they are located in narrow spaces, close to vertebrae and intervertebral discs. At these locations, nerve roots can be subjected to mechanical compression in association with, for example, disc herniation, spinal stenosis and spine trauma. In this article, basic aspects of the anatomy and physiology of nerve roots are reviewed. Nerve fiber arrangements, connective tissue layers and blood supply are described. The effects of compression on nerve root structure and function are summarized, based on experimental studies involving analyses of nerve function, nutrition, including blood flow, and edema formation in the nerve root. Pain mechanisms in nerve root compression are reviewed in relation to various clinical conditions.