NIH Stroke Scale (NIHSS)
15-item neurological assessment tool quantifying stroke severity. Guides thrombolysis eligibility and predicts outcome.
Score interpretation
NIHSS 0: No detectable stroke symptoms
→ Consider TIA if rapid resolution; ABCD² score; antiplatelet; neurology review
NIHSS 1–4: Minor stroke
→ Consider thrombolysis if within window; dual antiplatelet 21 days; urgent brain imaging; admit for monitoring
NIHSS 5–15: Moderate stroke
→ IV alteplase if eligible (within 4.5h); mechanical thrombectomy if large vessel occlusion; stroke unit; antihypertensive caution first 24h
NIHSS 16–20: Moderate-severe stroke
→ Thrombectomy if LVO; consider decompressive craniectomy in malignant MCA; stroke unit/HDU; PEG if dysphagia; physio/SALT/OT
NIHSS >20: Severe stroke
→ Thrombectomy evaluation; goals of care discussion; ICU if deteriorating; neuropalliative care planning
Interpretation bands for the NIHSS. Apply clinical judgement and local guidance.
References
- Brott T, et al. Measurements of acute cerebral infarction: a clinical examination scale. Stroke. 1989;20(7):864-870.
Related
Curated clinical cross-links plus same-class fallbacks.
- Acute Stroke / TIA Assessment · NICE NG128; RCP Stroke Guidelines 2023
- Status Epilepticus (Adults) · NICE CG137; ESEM guidelines; RCP Neurology Guidelines
- Suspected Subarachnoid Haemorrhage · NICE NG228; RCEM 2023; AHA/ASA 2023
- Adult Head Injury · NICE NG232 (2023)
- Bell's Palsy / Facial Nerve Palsy · ENT UK 2017; AAN
- Vertigo Workup · ENT UK; NICE CKS
Featured in these MRCEM clinical pathways
The NIHSS is covered in detail — with RCEM/NICE evidence base, indications and pitfalls — in the following exam-focused pathways on our sister siteReviseMRCEM.
MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.