Neurology of the Spine

Abstract

The embryological appearance of a vertebral column marks the beginning of the final stages of neural development. The peripheral nerves develop from cells adjacent to the embryonic neural crest. They develop from ectodermal tissue and continue to proliferate and eventually lie in long strands along the dorsal aspect of the neural tube. In the developing embryo, nerve elements lie in a homogenous undifferentiated mass at first, but at the limb bud level sheets of nerve fibers infiltrate the primitive muscle mass lying about the skeletal core. As the limb grows, the muscle mass develops into individual muscles, drawing the nerve connections with it. The nerve roots around the upper extremities form the brachial plexus, while those around the lower extremities form the lumbosacral plexus.