NIH Stroke Scale (NIHSS) Calculator
Calculate the NIH Stroke Scale score to quantify stroke severity. NIHSS assesses 11 items including consciousness, gaze, visual fields, facial palsy, motor function, ataxia, sensory, language, dysarthria, and extinction. Score 0 = no symptoms, 1-4 = minor, 5-15 = moderate, 16-20 = moderate-severe, 21-42 = severe.
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1. Level of Consciousness
2-4. Gaze, Visual, Facial
5-6. Motor
7-11. Ataxia, Sensory, Language, Extinction
Recommendations
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⚠️For informational purposes only — not medical advice. Consult a healthcare professional before acting on results.
The NIH Stroke Scale (NIHSS) is a 15-item standardized assessment developed by the NIH to quantify neurological deficits in acute stroke. Scores range from 0 (no deficit) to 42. It evaluates consciousness (1a-1c), gaze, visual fields, facial palsy, motor arms/legs, ataxia, sensory, language, dysarthria, and extinction. NIHSS guides tPA eligibility, thrombectomy consideration, and outcome prediction.
Sources: Brott T Stroke 1989; NIH/NINDS.
Key Takeaways
- • NIHSS 0-4: Minor stroke; consider tPA based on window and risk.
- • NIHSS 5-15: Moderate; urgent tPA and CTA for LVO.
- • NIHSS ≥6: Thrombectomy candidate evaluation.
- • Motor score (max 16) is often largest contributor.
Did You Know?
How Does NIHSS Work?
Scoring
Each item is scored 0 (normal) to max (e.g., 4 for motor). Total = sum of all 15 items. Worst response in each category is used.
Interpretation
0 = no symptoms; 1-4 = minor; 5-15 = moderate; 16-20 = moderate-severe; 21-42 = severe. Higher scores = worse prognosis.
Treatment
tPA within 4.5h if eligible. NIHSS ≥6: consider CTA for LVO and thrombectomy. Serial NIHSS tracks improvement.
Expert Tips
NIHSS Severity Reference
| Score | Severity |
|---|---|
| 0 | No stroke symptoms |
| 1-4 | Minor stroke |
| 5-15 | Moderate stroke |
| 16-20 | Moderate-severe |
| 21-42 | Severe stroke |
Frequently Asked Questions
What is the NIH Stroke Scale?
The NIHSS is a 15-item standardized assessment that quantifies neurological deficits in acute stroke. Scores range from 0 (no deficit) to 42 (maximum). It evaluates consciousness, gaze, visual fields, facial palsy, motor function (arms/legs), ataxia, sensory, language, dysarthria, and extinction/inattention.
How is NIHSS interpreted?
0 = no symptoms; 1-4 = minor stroke; 5-15 = moderate; 16-20 = moderate-severe; 21-42 = severe. NIHSS guides tPA eligibility (within 4.5h window), thrombectomy consideration (NIHSS ≥6), and prognostication. Higher scores correlate with worse outcomes.
When should NIHSS be performed?
At initial stroke presentation, before treatment decisions, 24h post-treatment, at discharge, and with any neurological change. Certified assessors improve reliability. Pre-sedation GCS/LOC should be used if patient is intubated.
What is the motor score contribution?
Motor function (items 5-6) contributes up to 16 points: 4 points per arm and per leg. Asymmetry helps localize (e.g., right arm/leg weakness suggests left MCA stroke). Motor is often the largest contributor to total NIHSS.
Who should use this calculator?
Emergency physicians, neurologists, stroke team members, and clinicians evaluating acute stroke. NIHSS is required for tPA and thrombectomy protocols. Training and certification improve inter-rater reliability.
Can this replace medical advice?
No. This tool is for educational purposes only. Clinical decisions require professional assessment. Always consult a qualified healthcare provider. Seek emergency care for stroke symptoms (FAST: Face, Arm, Speech, Time).
Key Statistics
Official Data Sources
⚠️ Disclaimer: This calculator is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider. Seek emergency care for stroke symptoms (FAST: Face drooping, Arm weakness, Speech difficulty, Time to call 911).