Aneurysmal Subarachnoid Hemorrhage Inclusion Criteria

Inclusion criteria included a diagnosis of SAH based on CT or the presence of xanthochromia in cerebrospinal fluid (CSF) in patients older than 18 years who were admitted within 48 h of symptoms onset (bleed day 0). Exclusion criteria included traumatic SAH, arteriovenous malformation (AVM), or other non-aneurysmal vascular lesions identified on digital subtraction angiography, the presence of auto-immune diseases, pro-inflammatory conditions like malignancy and pregnancy, and the diagnosis of isolated perimesencephalic SAH. A flowchart depicting the patients selected for analysis is shown in Supplementary Figure 1.