Experimental cervical myelopathy: effects of compression and ischemia on the canine cervical cord

Abstract

✓ Maximal tolerable compression was produced in 28 dogs by advancing a screw through the anterior portion of the C-5 vertebral body into the spinal canal until limb weakness occurred. Chronic vascular insufficiency was established in the cervical cord of 17 dogs by blocking or ligating the spinal and vertebral arteries and their branches in various combinations. Vascular insufficiency was also established in combination with maximal compression. Neurological, microangiographic, and histological findings in all groups of dogs were compared. Dogs in the last group with the most severe injury had more abnormal findings in surface vessels than did all other dogs. When the dogs were bled to the point of weakness, that point also appeared soonest in the last group. From these findings, the authors conclude that the effects of vascular insufficiency and compression are additive and that this may be an explanation of the clinical signs in patients with cervical spondylotic myelopathy who appear to have relatively slight mechanical compression.