NIH Stroke Scale (NIHSS) Calculator

NIH Stroke Scale (NIHSS): Explanation and Clinical Context The NIH Stroke Scale (NIHSS) is a standardized tool developed by the National Institutes of Health to objectively quantify the neurological deficit in acute stroke patients. It evaluates 11 domains of neurological function, including level of consciousness, gaze, vision, facial movement, motor strength, ataxia, sensation, speech, and neglect. The total score ranges from 0 to 42, with higher scores indicating greater neurological impairment.

Clinically, the NIHSS score assists physicians in multiple aspects of stroke management — from identifying stroke severity, selecting candidates for reperfusion therapy (such as intravenous thrombolysis or thrombectomy), to monitoring recovery or deterioration during hospitalization. A score of 0 suggests no stroke symptoms, 1–4 indicates minor stroke, 5–15 moderate stroke, 16–20 moderate to severe stroke, and 21–42 severe stroke. Scores above 20 are associated with a higher risk of poor functional outcomes and mortality.

This scale has been validated in numerous trials and remains a cornerstone of acute stroke evaluation. Regular use of NIHSS promotes consistency in clinical assessment and enhances communication across multidisciplinary teams in stroke centers.