Bacterial Meningitis Following Aneurysmal Subarachnoid Hemorrhage and Its Association with Cerebral Vasospasm

Aneurysmal subarachnoid hemorrhage (aSAH) is a critical condition with high in-hospital mortality rates. Delayed cerebral ischemia (DCI), a secondary complication associated with aSAH, can also contribute to morbidity and mortality. Although draining the hematoma from the subarachnoid space has been considered effective in preventing DCI, the placement of a drainage system could increase the risk of bacterial meningitis and ventriculitis. This study aimed to examine the association between meningitis following aSAH and the occurrence of DCI, focusing on the role of cerebral vasospasm. Patients who underwent endovascular coiling or surgical clipping for aSAH from April 2001 to March 2022 were included in this study, while those who did not undergo postoperative drainage were excluded. The patient's clinical characteristics, treatment modalities, and outcomes were then analyzed, after which logistic regression was used to assess the odds ratios (OR) for DCI. A total of 810 patients with aSAH were included in this study. Meningitis following aSAH was identified as an independent factor associated with DCI (odds ratio 5.0 [95% confidence intervals (CI) 2.3-11]). Other significant factors were female sex (odds ratio 1.5 [95% CI 0.89-2.5]) and surgical clipping (odds ratio 2.1 [95% CI 1.3-3.4]). This study demonstrated a significant association between meningitis following aSAH and the development of DCI, suggesting that the inflammatory environment associated with meningitis may contribute to cerebral vasospasm. Early recognition and treatment of meningitis in patients with aSAH could reduce the risk of DCI and improve patient outcomes.