Massive Ischemic Stroke: Definitions, Large Infarct Criteria, and NIHSS Correlation

This brief but focused session defines massive or malignant ischemic stroke, establishes criteria for large infarcts based on vascular territory involvement, and examines the correlation between NIH stroke scale scores and infarct size.

Practitioner-Guided Note

A massive or malignant stroke involves two vascular territories (e.g., MCA plus ACA or PCA), CT hypodensity over 50% of the MCA territory, and NIHSS above 20. A large infarct involves more than one-third of the MCA territory or more than half of the PCA territory. An NIHSS above 15 is a strong indicator of a large infarct and a contraindication to anticoagulation.

Key Takeaways

Massive or malignant stroke: involves two vascular territories, CT hypodensity over 50% of MCA territory, and NIHSS above 20.Large infarct: more than one-third of MCA territory or more than half of PCA territory on CT or MRI.NIHSS above 15 is a strong clinical indicator of a large infarct.