Vascular and neural pathology of lumbosacral spinal stenosis

Abstract

During a study of the intrinsic vasculature of the lumbosacral spinal nerve roots in cadavers, a typical case of spinal stenosis was encountered. A review of the antemortem anamnesis revealed that this patient had had an intermittent claudication of the cauda equina. Investigation of the concomitant vascular and histopathological alterations of the affected nerve roots suggested that the claudication may have resulted from ectopic nerve impulse discharges elicited by rapid changes in the blood supply following exertion. The unexpectedly slight apparent neural deficit relative to observed root damage may be attributed to a neuronal plasticity within the spinal cord that permitted functional compensations to develop during the slow acquisition of the chronic nerve root pathology.

Effects of experimental graded compression on blood flow in spinal nerve roots. A vital microscopic study on the porcine cauda equina

“…According to the results in the present study, pressures of this magnitude would result in total ischemia of the compressed parts of the nerve roots. On the other hand, in spinal stenosis there is probably a wide range of pressures, also including relative low pressures, acting on the nerve roots (22,28). The clinical picture, with symptoms at exercise that decline at rest, suggests that the impairment of the blood flow in the nerve roots is incomplete in the resting situations.…”

Outcomes of a prospective cohort study on peri-radicular infiltration for radicular pain in patients with lumbar disc herniation and spinal stenosis

“…In spinal stenosis, chronic mechanical compression and indirect vascular insufficiency lead to nerve root ischaemia and demyelination [31]. In contrast, experimental studies of the effect of LDH on the nerve root have shown that, in addition to mechanical compression, chemical irritation from the immunogenic substance of disc material may have a significant role in radiculopathy [7,20,21,22,24].…”

Phrenic paresis—a possible additional spinal cord dysfunction induced by neck manipulation in cervical spondylotic myelopathy (CSM): A report of two cases with anatomical and clinical considerations

“…For this reason, the authors have chosen the more inclusive term "paresis" rather than "paralysis" to refer to a possible range of compressive impairments even though the effects may be occult. Also, most CSM is a relatively slowly developing condition, and as was noted by Watanabe and Parke (1986) in stenosis of the lumbar spine, and by Ito et al (1996) in comparable cervical constrictions with gradually acquired cord compressions, there was evidence that some neuronal regeneration and reassociation may preserve some of the more essential functions. Considering the extent of midcervical spinal cord compression evident before the cervical manipulation in both of the cases presented here, it is very probable that some degree of phrenic nerve impairment existed before the operative incidents, and it was the additional insult that then elicited the more obvious manifestations of the phrenic paresis.…”