Spinal Arachnoiditis and The Axonal Degeneration of The Spinal Nerve Roots Due to Ischemia Induced By Vasospasm: An Experimental Study

Objective: Various reasons have been ascribed to arachnoiditis development, among which subarachnoid hemorrhage (SAH) may be an important factor in this process. In this experimental study, we investigated the effect of SAH on histopathological findings. The volumetric changes of the radicular arteries and the density of spinal nerve root axons of a SAH model on C4 roots in rabbits were measured.Materials and Methods: In this study, 18 rabbits were used. The animals were randomly divided into three groups: subarachnoid hemorrhage (SAH; n = 10), physiologic serum (SF; n = 4) and control (n = 4) groups. SAH was performed by injecting 0.5 cc of blood into cisterna magna taken from their auricular veins. Cervical spinal nerve roots at the C4 level were examined histopathologically.Results: Meningeal thickening and adhesions, reddish spinal cord and radices were detected macroscopically. Histopathologically, leptomeningeal adhesions, intimal lesions of radicular arteries and axonal injury were detected at the nerve radices. The mean radicular artery volume was found to be low on the arachnoiditis developing animals. The mean alive axon density of the C4 nerve root decreased and axonal degeneration was observed in the SAH group.Conclusion: Our study suggests that SAH may be an important etiologic factor in spinal arachnoiditis.