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NIH Stroke Scale (NIHSS)

Also called NIHSS, National Institutes of Health Stroke Scale, stroke severity score

Standard 15-item bedside examination of stroke deficit, total 0 to 42, used for thrombolysis and thrombectomy decisions and trial entry.

1a. Level of consciousness
1b. LOC questions (month, age)

Intubated, severe dysarthria or language barrier = 1; aphasic or stuporous = 2.

1c. LOC commands (eyes, grip)
2. Best gaze
3. Visual fields
4. Facial palsy
5a. Motor arm, left

Arm at 90° sitting or 45° supine for 10 s.

5b. Motor arm, right
6a. Motor leg, left

Leg at 30° supine for 5 s.

6b. Motor leg, right
7. Limb ataxia

Score only if out of proportion to weakness; absent if the patient cannot understand or is paralysed.

8. Sensory

Coma (1a = 3) scores 2.

9. Best language

Coma (1a = 3) scores 3.

10. Dysarthria
11. Extinction and inattention

Fill 15 more fields to see the result.

Formula and scoring

Sum of items 1a–11 (5 and 6 scored for each limb). Range 0–42. Score what the patient does, not what you think the patient can do; record the first attempt.

Exam and ward pearls

  • A patient in coma (1a = 3) is automatically scored 2 on sensory and 3 on language.
  • UN is allowed only for motor items (amputation or joint fusion), ataxia, and dysarthria (intubation). Item 11 is never untestable.
  • Ataxia is scored only when out of proportion to weakness, so a plegic limb scores 0 for ataxia.

When not to rely on it

  • Needs trained examiners: interrater agreement in the derivation study was good overall (mean kappa 0.69) but varied by item.
  • Not a diagnostic test for stroke; stroke mimics can score.

Source

  1. Brott T, Adams HP Jr, Olinger CP, Marler JR, Barsan WG, Biller J, et al. Measurements of acute cerebral infarction: a clinical examination scale. Stroke. 1989;20(7):864-70. doi:10.1161/01.str.20.7.864 · PMID 2749846
  2. National Institute of Neurological Disorders and Stroke. NIH Stroke Scale (Know Stroke booklet), item definitions and scoring. Link

Formula and cut-offs checked against these sources on 8 Nov 2026. Educational tool for clinicians; it does not replace clinical judgement.

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