Brachial Artery Vasospasm Caused by Cervical Dorsal Root Ganglion Degeneration After Subarachnoid Hemorrhage: An Experimental Study

Abstract

Subarachnoid hemorrhage (SAH) may lead to vasospasm in various vessels. The cervical nerves have a vasodilatory effect on the upper extremity arteries. The aim of this study was to investigate if there is a relationship between C6 dorsal root ganglion (DRG) degeneration and brachial artery (BA) vasospasm after spinal SAH. This experimental study was conducted on 23 rabbits. The animals were divided into 3 groups: control (n= 5), SHAM (n= 5), and study group (n= 13). One cubic centimeter (cc) of serum saline was injected into the cisterna magna of animals of the SHAM group; the same procedure was performed by 1 cc of homologous blood in the study group. Degenerated neuron densities (DNDs) of DRGs (n/mm3) at C6 levels and BA vasospasm indexes (VSI; wall surface/lumen surface) of all animals were determined and results were analyzed statistically. Mean VSI values of BAs and DNDs of C6DRGs of the control, SHAM, and study groups were estimated as 10 ± 3/1.12 ± 0.11 n/mm3, 34 ± 9/1.27 ± 0.24 n/mm3, and 1031 ± 145/2.93 ± 0.78 n/mm3, respectively. Mean DNDs and VSI values were statistically significantly different between the control and study groups (P < 0.0001). C6DRG degeneration may be considered as an important factor in the etiopathogenesis of severe BA vasospasm after SAH.