Subarachnoid Hemorrhage in Bacterial Meningitis Patients

Introduction: Subarachnoid hemorrhage (SAH) has been described as an uncommon complication of community-acquired bacterial meningitis. However, the incidence, clinical course, and outcome are unclear. Methods: We assessed the clinical characteristics, incidence, and clinical outcome of patients with SAH complicating bacterial meningitis in a prospective nationwide cohort study from 2006 to 2018 in the Netherlands. Patients were identified through the Netherlands Reference Laboratory for Bacterial Meningitis, which receives around 90% of CSF isolates of all Dutch patients with bacterial meningitis, or after direct report by the treating physician. Results: SAH was diagnosed in 22 of 2,306 episodes (0.9%), of which 7 (32%) were diagnosed upon admission and 15 (68%) during admission. All patients showed clinical deterioration before SAH was diagnosed: altered mental status in 18 of 22 patients (82%), focal neurological symptoms in 2 (9%) and, new-onset fever with severe tachycardia in 1 (5%). Acute onset of headache was not reported in any of the patients. Distribution of blood was diffuse in the subarachnoid space in 7 patients (32%), multifocal in 8 patients (36%), and focal in 7 patients (32%) of 22 patients. In 6 patients (27%), CT angiography, MR angiography, or digital subtraction angiography was performed, showing a mycotic aneurysm in 1 patient (5%) and vasculitis in 1 patient (5%). Presence of SAH in bacterial meningitis patients was associated with a poor prognosis assessed at discharge: 12 of 22 patients with SAH died (54%) compared to 361 of 2,257 (16%, p < 0.001) without SAH, and 19 of 22 had an unfavorable outcome (86%) compared to 831 of 2,257 (37%, p < 0.001). Conclusion: SAH is an uncommon complication in bacterial meningitis and is associated with high case fatality and morbidity.