The Role of Pterygopalatine Ganglion Neuron Density in the Severity of APA Vasospasm Following Subarachnoid Hemorrhage: A Preliminary Experimental Study

Introduction: Anterior perforating arteries (APA) play a critical role in cerebral circulation. Whether there is a correlation between APA vasospasm and the neuronal density of the pterygopalatine ganglion during subarachnoid hemorrhage (SAH) has not yet been elucidated. Methods: This study included 21 rabbits, divided into three groups: control (n=5), sham (n=5), and SAH (n=11). SAH was induced by injecting autologous blood into the cisterna magna. Seven days post-induction, the animals were decapitated, and both the APA and pterygopalatine ganglia were stereologically analyzed. Vasospasm severity was quantified using the vasospasm index (VSI). VSI values and neuronal densities were statistically evaluated using the Kruskal-Wallis and Mann-Whitney U tests, with significance set at p < 0.005. Results: Significant differences were found among the groups in both VSI values and neuronal densities. The control group exhibited a VSI of 0.234 ± 0.031, the sham group 0.995 ± 0.121, and the SAH group showed 1.127 ± 0.654 in cases of mild vasospasm and 2.126 ± 0.986 in cases of severe vasospasm. Neuronal density was also significantly reduced in the SAH group compared to the control group. Conclusion: The neuronal density of the pterygopalatine ganglion may significantly influence the severity of APA vasospasm following subarachnoid hemorrhage.