Spinal cord blood flow patterns in experimental traumatic paraplegia

Abstract

✓ Alterations in spinal cord blood flow patterns in experimental traumatic paraplegia were studied by using thioflavine S, a fluorescent dye that stains the endothelium of blood vessels. Feline spinal cords, exposed by laminectomy, were traumatized with a 400 gm-cm contusion, and a rapid intravenous injection of thioflavine S administered. The spinal cords were excised within one circulation time after the injection, and the resulting spinal cord sections were examined under ultraviolet light. As thioflavine S is a fluorescent substance that binds to the blood vessel walls and as the spinal cord was excised within one circulation time, it was possible to determine in which vessels blood was flowing at the time of injection. Control animals showed blood flow in all parts of the spinal cord. At 15 min postcontusion there was a marked decrease in the number of vessels perfused in the white matter; however, at 30 min many of the vessels had evidence of renewed blood flow. By 1 hr postcontusion the entire gray matter showed hemorrhagic infarction. The number of fluorescing vessels in the white matter decreased considerably between 1 and 8 hrs postcontusion. At 8 hrs the thioflavine S-stained vessels were limited to the peripheral half of the white matter; however, by 24 hrs most of the vessels again fluoresced, but the gray matter remained without perfusion. In this experimentally-produced lesion, the gray matter of the spinal cord was infarcted by 1 hr postcontusion; the white matter was ischemic between 1 and 8 hrs with resumed blood flow by 24 hrs.