Changes of blood flow, oxygen tension, action potential and vascular permeability induced by arterial ischemia or venous congestion on the spinal cord in canine model.

It is generally considered that the genesis of myelopathy associated with the degenerative conditions of the spine may result from both mechanical compression and circulatory disturbance. Many references about spinal cord tissue ischemic damage can be found in the literature, but not detailed studies about spinal cord microvasculature damage related to congestion or blood permeability. This study investigates the effect of ischemia and congestion on the spinal cord using an in vivo model.

Experimental syringohydromyelia induced by adhesive arachnoiditis in the rabbit: changes in the blood-spinal cord barrier, neuroinflammatory foci, and syrinx formation.

There are many histological examinations of syringohydromyelia in the literature. However, there has been very little experimental work on blood permeability in the spinal cord vessels and ultrastructural changes. We prepared an animal model of spinal adhesive arachnoiditis by injecting kaolin into the subarachnoid space at the eighth thoracic vertebra of rabbits.

Vasomotion of intraradicular microvessels in rat.

Study Design: This study is to investigate the changes of vasomotion of intraradicular microvessels in vivo.

Objective: We have observed microvascular corrosion casts of the lumbar nerve root by scanning electron microscopy and used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerve in blood vessels of the nerve root.

Summary Of Background Data: It is generally considered that the genesis of radiculopathy associated with the degenerative conditions of the spine may result from both mechanical compression and circulatory disturbance.

Fine structure of cartilage canal and vascular buds in the rabbit vertebral endplate. Laboratory investigation.

Object: The vascular terminations (vascular buds) in the bone-disc junction area are structurally very similar to cartilage. In all previous studies to date, however, the roles of cartilage canals and vascular buds were mainly discussed using histological and transparent sections but not electron microscopic sections. The purpose of this study was to clarify the ultrastructure of the vascular bud seen in the bone-disc junction in comparison to the cartilage canal.

Atlantoaxial subluxation-induced myelopathy in cleidocranial dysplasia. Case report.

The authors describe the clinical course and treatment of a patient with cleidocranial dysplasia in whom spastic myelopathy developed due to atlantoaxial subluxation. This 27-year-old woman with cleidocranial dysplasia and a history of atlantoaxial subluxation presented with spastic myelopathy. Surgery was performed twice for cervical myelopathy and atlantoaxial subluxation, including laminectomy at the atlas and cervicooccipital fusion in which the Luque rod system was used, as well as C1-2 fusion via the transpharyngeal route.

Effect of mechanical compression on the lumbar nerve root: localization and changes of intraradicular inflammatory cytokines, nitric oxide, and cyclooxygenase.

Study Design: Investigation of intraradicular inflammation induced by mechanical compression.

Objective: To investigate the mechanism of nerve root pain, this study used a lumbar nerve root compression model.

Summary Of Background Data: The manifestation of pain at sites of inflammation has a close relationship with the release of mediators from macrophages.

Localization and changes of intraneural inflammatory cytokines and inducible-nitric oxide induced by mechanical compression.

Study Design: Investigation of intraneural inflammation induced by mechanical compression.

Objectives: In order to investigate the mechanism of neuropathy, this study used a median nerve compression model in dogs. Immunohistochemistry was used to examine the localization and changes of inflammatory cytokines and nitric oxide (NO).

Commentary on the prevention of paralysis after traumatic spinal cord injury in humans: the neglected factor--urgent restoration of spinal cord circulation.

Although advances in the management of spinal injuries during the past 60 years have led to greatly increased life expectancy for paralysed patients, most remain disabled. Around the world, spinal injury centres have become specialized rehabilitation units, where staff accepts the inevitability of persisting paralysis. In part, this pessimism has been based on incorrect information about the anatomy and function of the circulation of the spinal cord.

Changes of calcitonin gene-related peptide in primary sensory neurons and their central branch after nerve root compression of the dog.

Objective: To investigate changes in axonal flow after nerve root compression by using immunohistochemical techniques to detect calcitonin gene-related peptide (CGRP), which is thought to be involved in pain sensation.

Design: Experimental, controlled study.

Setting: University medical school in Japan.

Effect of lumbar nerve root compression on primary sensory neurons and their central branches: changes in the nociceptive neuropeptides substance P and somatostatin.

Study Design: This study examined the effect of lumbar nerve root compression on nociceptive neuropeptides in the axonal flow using an in vivo model.

Objectives: The aim was to investigate changes in axonal flow after nerve root compression by using immunohistochemical techniques to detect substance P (SP) and somatostatin (SOM), which is thought to be involved in temperature and pain sensation.

Summary Of Background Data: Disturbance of intraradicular blood flow and nerve fiber deformation caused by mechanical compression are thought to be involved in the pathophysiology of diseases characterized by radicular symptoms, such as lumbar disc herniation and lumbar canal stenosis.

Pathology of lumbar nerve root compression. Part 2: morphological and immunohistochemical changes of dorsal root ganglion.

Study Design: This study is to investigate the changes of dorsal root ganglion (DRG) induced by mechanical compression using in vivo model.

Objectives: The effect of axonal flow disturbance induced by nerve root compression was determined in DRG.

Summary Of Background Data: The dorsal root ganglion should not be overlooked when considering the mechanism of low back pain and sciatica, so it is important to understand the morphologic and functional changes that occur in primary sensory neurons of the dorsal root ganglion as a result of nerve root compression.

Pathology of lumbar nerve root compression. Part 1: Intraradicular inflammatory changes induced by mechanical compression.

Study Design: This study is to investigate the intraradicular inflammation induced by mechanical compression using in vivo model.

Objectives: The relationship between the intraradicular edema and nerve fiber degeneration induced by mechanical compression was determined in the nerve root.

Summary Of Background Data: Recently some studies reported that mechanical compression increased microvascular permeability of the endoneurial capillaries and resulted in an intraradicular inflammation.

Changes in nerve root motion and intraradicular blood flow during intraoperative femoral nerve stretch test. Report of four cases.

Object: It is not known whether changes in intraradicular blood flow (IRBF) occur during the femoral nerve stretch test (FNST) in patients with lumbar disc herniation. An FNST was conducted in patients with lumbar disc herniation to observe the changes in IRBF, and results were then compared with clinical features.

Methods: The study was composed of four patients with L3-4 disc herniation who underwent microdiscectomy.

Changes in nerve root motion and intraradicular blood flow during an intraoperative straight-leg-raising test.

Study Design: An intraoperative straight-leg-raising (SLR) test was conducted to investigate patients with lumbar disc herniation to observe the changes in intraradicular blood flow, which then were compared with the clinical features.

Objective: The legs of each patient were hung down from the operating table as a reverse SLR test during surgery, and intraradicular blood flow was measured.

Summary Of Background Data: It is not known whether intraradicular blood flow changes during the SLR test in patients with lumbar disc herniation.

Effect of mechanical compression on the vascular permeability of the dorsal root ganglion.

The dorsal root ganglion contains primary sensory neurons and is closely related to low back pain and sciatia. The present study investigated whether endoneurial edema, which is involved in the onset of pain and nerve dysfunction, was increased in the dorsal root ganglion by compression. The influence of mechanical compression on the vascular permeability of the lumbar dorsal root ganglion was determined.