Clinical Assessment of Stroke Severity Scales

Clinical assessment of stroke severity relies primarily on structured scales that quantify the extent of neurological deficit, guide therapeutic choices and predict outcomes. The National Institutes of Health Stroke Scale (NIHSS) remains the most widely adopted instrument, evaluating consciousness, motor function, language, sensory loss, visual fields and neglect through a 42-point score. Modifications and alternatives have been proposed to address recognised limitations, such as underrepresentation of right hemisphere dysfunction and cognitive impairment. Other scales, including the Canadian Neurological Scale, Scandinavian Stroke Scale and Acute Physiology and Chronic Health Evaluation (APACHE), offer complementary perspectives on prognosis and intensive care needs. Contemporary work emphasises refinement of item weighting, integration of cognitive tasks, digital delivery and automated scoring to improve interrater reliability and to expedite assessment in hyperacute settings. Advances in imaging and biomarker research have also spurred efforts to correlate severity scores with lesion volume and tissue viability, facilitating personalised management pathways. As endovascular and reperfusion therapies extend treatment windows, rapid and accurate severity assessment remains central to optimising benefit–risk balance and supporting equitable care worldwide.

Research from Nature Portfolio

Recent studies have analysed how different reperfusion strategies influence specific NIHSS domains. In large vessel occlusion, combined endovascular thrombectomy and intravenous thrombolysis produced the most pronounced improvements across all neurological functions, with cortical language recovery consistently exceeding gains in motor strength. This differential response underscores the importance of domain-specific analysis when interpreting aggregate severity scores and planning rehabilitation. Findings suggest that language items in the NIHSS may serve as sensitive markers of perfusion restoration, guiding post-procedure prognostication and resource allocation.

Clinical Assessment of Stroke Severity Scales publication trend

The graph below shows the total number of articles in clinical assessment of stroke severity scales across all publications each year (not limited to Nature Index journals).

Technical terms

National Institutes of Health Stroke Scale (NIHSS): A standardised tool comprising 11 items to quantify stroke-related neurological deficit, with scores ranging from 0 (no deficit) to 42 (severe deficit).

Endovascular thrombectomy (EVT): A mechanical procedure to remove a clot from a cerebral artery, often used in conjunction with intravenous thrombolysis.

Reperfusion therapy: Treatments aiming to restore blood flow in ischaemic stroke, including thrombolytic drugs and thrombectomy devices.

Neglect: A deficit in attention or awareness of one side of space, assessed in the NIHSS by visual-spatial tasks.

Lesion volume: The size of infarcted brain tissue measured on imaging, often correlated with clinical severity scores.

References

1. Asynchronous Distance Learning Performance and Knowledge Retention of the National Institutes of Health Stroke Scale Among Health Care Professionals Using Video or e-Learning: Web-based Randomized Controlled Trial.. Journal of Medical Internet Research (2025).
2. Relative improvement in language vs. motor functions with reperfusion therapies for large vessel occlusion. Scientific Reports (2025).
3. Neglect scoring modifications in the National Institutes of Health Stroke Scale improve right hemisphere stroke lesion volume prediction. European Journal of Neurology (2023).
4. Left Hemisphere Bias of NIH Stroke Scale Is Most Severe for Middle Cerebral Artery Strokes. Frontiers in Neurology (2022).