[Variations in spinal cord blood flow in stepwise spinal cord impaction injury]

Referring to the experimental study on acute spinal cord injury, it is known that gray matter falls into an ischemia after injury, but opinions have not been unanimous whether or not the white matter falls into ischemia or hyperemia. The blood flow through the white matter varies according to the severity of the injury and degree of resultant paraplegia. Using rabbits, the authors carried out a series of experimental acute spinal cord impaction injury giving impactions at different strength stepwise, i.e., 400, 300, 200 and 100 gcf (g X cm X force) respectively at the 9th thoracic level of the spinal cord. Thus, upon observation of the paralysed levels and measurement of variable spinal cord blood flows according to the hydrogen clearance method, it was concluded as follows: In the 400 and 300 gcf impaction groups a complete paraplegia was observed with a decrease of spinal cord blood flow both in the gray and white matters. In the 200 gcf group mainly incomplete paraplegia was occurred, and while gray matter showed ischemia, white matter showed indefinite response consisting of both ischemia and hyperemia. In the 100 gcf impaction group the gray matter fell into ischemia, but white matter showed a biphasic increase of blood flow. From the above results it was noted that upon impaction causing complete paraplegia spinal white matter shows ischemia and upon impaction giving transient paraplegia blood flow increases. Ischemia thus does not appear to be a common behavior of spinal cord blood flow spinal cord injury.