NIH Stroke Scale Calculator

The NIH Stroke Scale (NIHSS) is a standardized 15-item neurological examination used to objectively quantify the severity of stroke-related impairment. It is widely used in acute stroke settings, clinical trials, and outcome prediction.

Each of the 15 items is scored on a scale of 0 to 2, 3, or 4 depending on the item. The total score ranges from 0 to 42, with higher scores indicating greater stroke severity.

A score of 0 indicates no stroke symptoms detectable on the NIHSS examination. However, a normal NIHSS does not completely rule out stroke, as some deficits may be subtle or not captured by the scale.

A score of 21 or higher is generally considered a severe stroke. Scores of 16–20 indicate moderate to severe stroke, and scores above 25 are associated with very poor outcomes.

Yes, the NIHSS can be used for ischemic stroke, hemorrhagic stroke, and transient ischemic attack (TIA). However, it may not capture all deficits in posterior circulation strokes or subtle cognitive impairments.

IV tPA (alteplase) is typically administered within 3 hours of symptom onset for eligible patients, with some guidelines extending to 4.5 hours based on imaging criteria and clinical factors.

Mechanical thrombectomy is an endovascular procedure where a catheter-based device is used to physically remove a blood clot from a large cerebral artery. It is typically performed up to 6–24 hours after stroke onset in selected patients.

The GCS measures level of consciousness (eye, verbal, motor responses) and is used broadly for neurological assessment, while the NIHSS is specifically designed to quantify stroke-related neurological deficits.

A TIA is a temporary episode of neurological dysfunction caused by focal brain ischemia without acute infarction. Symptoms typically resolve within 1–2 hours and always within 24 hours.

Ischemic stroke (about 87% of cases) is caused by a blood clot blocking a cerebral artery. Hemorrhagic stroke (about 13%) is caused by a ruptured blood vessel bleeding into the brain.

The CHA₂DS₂-VASc score is a clinical prediction tool used to estimate the risk of stroke in patients with atrial fibrillation. It considers factors like congestive heart failure, hypertension, age, diabetes, and prior stroke.

Yes, baseline NIHSS score is one of the strongest predictors of 3-month functional outcome after ischemic stroke. Higher scores are associated with increased mortality and disability.

A full NIHSS assessment by a trained clinician typically takes 5–15 minutes. The scale is designed to be quick and reliable in acute settings.

The NIHSS requires formal certification through the National Stroke Association or American Heart Association. Online training and certification are available and typically take 2–3 hours.

Motor arm, motor leg, and language items have the strongest predictive value for 3-month functional outcome. LOC and gaze items also contribute significantly.

A stroke causes permanent brain damage due to prolonged ischemia, while a TIA causes temporary symptoms without infarction. TIA symptoms always resolve, but it is a strong warning sign for future stroke.

FAST stands for Face drooping, Arm weakness, Speech difficulty, and Time to call emergency services. It is a simple screening tool for the public to recognize stroke symptoms.

For patients eligible for tPA, blood pressure must be lowered to <185/110 mmHg before administration. For non-thrombolysis patients, permissive hypertension is often allowed up to 220/120 mmHg.

The HAS-BLED score is a bleeding risk assessment tool for patients on anticoagulation for atrial fibrillation. It helps clinicians weigh the risks and benefits of anticoagulation therapy.

Antiplatelet agents like aspirin, clopidogrel, and dipyridamole are used for secondary prevention of ischemic stroke. They reduce the risk of recurrent stroke by preventing platelet aggregation.

A lacunar stroke is a small subcortical infarct caused by occlusion of a single small penetrating artery. They are often associated with hypertension and diabetes and have a relatively good prognosis.

Pediatric stroke is rare but occurs. The NIHSS can be used in older children with some modifications, but pediatric stroke assessment often requires age-specific scales.

The APGAR score is a quick newborn assessment performed at 1 and 5 minutes after birth. It evaluates Appearance, Pulse, Grimace, Activity, and Respiration on a 0–2 scale.

In acute stroke, the NIHSS is typically performed at baseline, 24 hours post-treatment, and at discharge. Serial assessments help track neurological improvement or deterioration.

Malignant MCA infarction is a life-threatening condition where a large middle cerebral artery stroke causes massive cerebral edema, midline shift, and herniation. It often requires decompressive hemicraniectomy.

The mRS is a 6-point disability scale from 0 (no symptoms) to 5 (severe disability) and 6 (death). It is commonly used as an outcome measure in stroke clinical trials.

The TOAST classification categorizes ischemic stroke into five subtypes: large artery atherosclerosis, cardioembolism, small vessel occlusion, other determined cause, and undetermined cause.

Diabetes increases the risk of ischemic stroke by 2–4 fold. It accelerates atherosclerosis, promotes endothelial dysfunction, and is associated with worse outcomes after stroke.

The ABC/2 method is a quick formula to estimate intracerebral hemorrhage volume on CT scan. It multiplies the three orthogonal diameters and divides by 2, using the largest cross-sectional area.

Cerebral edema is swelling of brain tissue following ischemic or hemorrhagic stroke. It typically peaks at 3–5 days and can cause neurological deterioration, herniation, and death if severe.

Statins reduce LDL cholesterol, stabilize atherosclerotic plaques, and have anti-inflammatory effects. They are a cornerstone of secondary stroke prevention for patients with ischemic stroke or TIA.