PATHOGENESIS OF MYELOPATHY IN CERVICAL SPONDYLOSIS

Abstract

A new explanation is offered for the pathogenesis of the myelopathy observed with cervical spondylosis. It is proposed that the root-sleeve fibrosis associated with the degenerative changes of the zygapophyseal and intervertebral joints can cause spasm of the lateral spinal arteries and their branches to the pial anastomoses. The spasm may originate either from direct stretching and kinking of these arteries during movement at the joints or may be mediated reflexly. The resultant intermittent cervical-cord ischæmia and loss of vascular autoregulation superimposed on a cord already compromised by external compression lead to a progressive myelopathy. This hypothesis assigns a major role to the degenerative changes compressing the cervical cord, but it is also compatible with the paradox that cervical cords with an ischæmic myelopathy do not show unequivocal histological evidence of vascular disease.