NIH Stroke Scale Calculator

The NIHSS aggregates scores across 15 distinct neurological examination parameters. Each individual category assesses a specific neurological function, yielding a point value where higher numbers indicate greater impairment. The final cumulative score is derived using the standard additive equation: Score = Responsiveness + Month and Age + Command + Best Gaze + Visual + Palsy + Left Arm + Right Arm + Left Leg + Right Leg + Ataxia + Sensation + Language + Dysarthria + Extinction. The total score ranges from 0 (no stroke symptoms) to 42 (severe impairment or coma).

Consider a patient undergoing a post-stroke evaluation in a clinical setting. The clinician assesses each variable systematically: Level of Consciousness Responsiveness yields 1 point, Month and Age questions yield 0 points, and Commands yield 0 points. Gaze testing yields 1 point for partial gaze palsy, and Visual testing adds 1 point for a partial hemianopia. Facial Palsy adds 2 points for a central lower facial weakness. Motor assessments show drift in the Left Arm (2 points) and moderate weakness in the Right Arm (1 point), while both Left Leg and Right Leg score 1 point each for drift. Limbs show no Ataxia (0 points). Mild to moderate sensory loss scores 1 point, Aphasia adds 2 points for Language deficits, mild Dysarthria scores 1 point, and visual Extinction adds 1 point. Summing these values together: Score = 1 + 0 + 0 + 1 + 1 + 2 + 2 + 1 + 1 + 1 + 0 + 1 + 2 + 1 + 1, resulting in a total NIHSS score of 15, indicating moderate stroke severity.

Always score what the patient actually does, not what you think they can do. Resist the temptation to guess or extrapolate values if a patient is uncooperative; grade their immediate response during the exam. Perform and record assessments in the exact order prescribed to ensure consistency across multidisciplinary shift handoffs.