NIH Stroke Scale (NIHSS) Score Sheet
The NIHSS is a standardized 11-item neurological assessment tool that quantifies stroke severity on a 0-42 point scale, with higher scores indicating more severe neurological deficits. 1
Scale Components and Scoring
The NIHSS evaluates 11 distinct neurological domains:
Consciousness Assessment (Items 1A-1C)
- 1A. Level of Consciousness: 0 (alert) to 3 (coma/unresponsive)
- 1B. Orientation Questions: 0 (both correct) to 2 (neither correct) - asks month and age
- 1C. Response to Commands: 0 (performs both) to 2 (performs neither) - tests ability to follow two simple commands
Cranial Nerve Function (Items 2-4)
- 2. Gaze: 0 (normal horizontal movements) to 2 (complete gaze palsy)
- 3. Visual Fields: 0 (no defect) to 3 (bilateral hemianopia)
- 4. Facial Movement: 0 (normal) to 3 (complete unilateral palsy)
Motor Function (Items 5-6)
- 5. Motor Arm (tested separately for left and right): 0 (no drift) to 4 (no movement)
- Scored based on ability to maintain position for 10 seconds
- 6. Motor Leg (tested separately for left and right): 0 (no drift) to 4 (no movement)
- Scored based on ability to maintain position for 5 seconds
Coordination and Sensation (Items 7-8)
- 7. Limb Ataxia: 0 (no ataxia) to 2 (ataxia in 2 limbs)
- 8. Sensory: 0 (no sensory loss) to 2 (severe sensory loss)
Language and Communication (Items 9-11)
- 9. Language: 0 (normal) to 3 (mute or global aphasia)
- 10. Articulation: 0 (normal) to 2 (severe dysarthria)
- 11. Extinction or Inattention: 0 (absent) to 2 (severe - loss in 2 modalities)
Clinical Applications
The NIHSS serves multiple critical functions in acute stroke management:
- Treatment eligibility determination - particularly for thrombolytic therapy and mechanical thrombectomy 2
- Baseline severity documentation - enables objective tracking of neurological changes over time 2
- Risk stratification - identifies patients at higher risk for complications including intracerebral hemorrhage 2
- Prognostic assessment - correlates with infarct volume, cerebral perfusion, and functional outcomes 3
- Standardized communication - facilitates clear information exchange between healthcare providers 1, 4
Administration Details
The scale can be performed rapidly in 5-8 minutes and may be administered by diverse healthcare providers including nurses, emergency physicians, and neurologists with appropriate training and certification 4. The assessment demonstrates established reliability and validity across multiple settings 2.
Important Clinical Considerations
Hemispheric bias exists: For equivalent NIHSS scores, right hemisphere strokes typically have approximately double the median infarct volume compared to left hemisphere strokes 5. This occurs because 7 of 42 possible points directly assess language function (predominantly left hemisphere) versus only 2 points for neglect (predominantly right hemisphere). Clinicians should recognize that identical NIHSS scores may represent different stroke severities depending on hemisphere involvement.
Baseline severity adjustment is essential when comparing outcomes across different stroke systems of care, as NIHSS strongly influences prognosis along with age, blood glucose, and imaging findings 2.
The scale's widespread adoption in quality improvement initiatives has been associated with improved timeliness of IV alteplase administration, lower in-hospital mortality, reduced intracranial hemorrhage rates, and increased home discharge rates 2.