Background: The anterior perforated arteries (APA) are crucial for cerebral circulation, yet the relationship between vasospasm in these arteries and neuron density in the pterygopalatine ganglion during subarachnoid hemorrhage remains unexplored.
Methods: This study was conducted on 21 rabbits previously utilized in other experiments. Five rabbits were selected from a baseline control group, five formed the sham group by receiving 1 cc of physiological serum, and sixteen were designated as the subarachnoid hemorrhage group. Subarachnoid hemorrhage was induced by injecting autologous blood into their cisterna magna. After seven days of observation, the animals were euthanized, and their APAs and pterygopalatine ganglia were examined stereologically. The ratio of the wall sectioning surface area (Wall ring) to the lumen surface values was calculated as the vasospasm index (VSI), with higher values indicating more severe vasospasm. Statistical comparisons of VSI values and neuron densities of the pterygopalatine ganglia were performed using the Kruskal-Wallis and Mann-Whitney U tests, with significance considered at p < 0.005.
Results: The average normal/degenerated neuronal density in the pterygopalatine ganglia and corresponding VSI values were 12.310±1.590/mm³/12±3/mm³ and VSI=0.234±0.031 in control animals (n=5). The sham group showed a neuronal density of 12.165±1.370/mm³/56±8/mm³ and a mean VSI of 0.995±0.121 (n=5); 10.110±1.170/mm³/782±112/mm³ and a VSI of 1.127±0.654/763±98/mm³ were observed with slight vasospasm (Study A: n=6). In animals with severe vasospasm (Study B: n=5), the mean neuronal density was 8960±990/mm³/1954±189/mm³ and the VSI was 2.126±0.986. Differences were significant at p<0.005 for Control/Sham; p<0.0005 for Sham/Study; and p<0.000001 for Control/Study.
Conclusions: Neuron density in the pterygopalatine ganglia may play a crucial role in the development of APA vasospasm induced by subarachnoid hemorrhage.