WFNS SAH Grade — Subarachnoid Hemorrhage Severity

The World Federation of Neurosurgical Societies (WFNS) Subarachnoid Hemorrhage (SAH) Grading Scale is a 5-grade classification of clinical severity in patients with aneurysmal subarachnoid hemorrhage, based on the Glasgow Coma Scale (GCS) score and the presence or absence of focal motor deficits. Developed by Drake et al. and adopted by the WFNS, it is the most widely used SAH grading system in neurosurgical practice, correlating with surgical risk, neurological outcome, and vasospasm risk.