NIHSS: National Institutes of Health Stroke Scale

The NIHSS is the standard acute stroke severity assessment tool used in emergency departments, stroke centers, and clinical trials worldwide. Developed by the NIH Stroke Study Group in 1989, the 15-item scale provides rapid, reproducible quantification of acute neurological deficit from ischemic or hemorrhagic stroke. NIHSS scores inform thrombolytic and thrombectomy eligibility, predict outcomes, and serve as primary endpoint in stroke intervention trials.