NIHSS sub-item scores predict collateral flow in acute middle cerebral artery infarction

The status of collateral vessels has important clinical implications in acute ischemic stroke. To evaluate which components of ischemic symptoms were predictive of pretreatment collateral status, we tested the hypothesis that sub-item scores from the National Institutes of Health Stroke Scale (NIHSS) are associated with leptomeningeal collateral status in acute ischemic stroke with middle cerebral artery (MCA) occlusion.

This study included consecutive patients with acute M1 occlusion who underwent revascularization treatment for acute MCA infarction. We evaluated clinical factors and the NIHSS score according to the collateral status assessed by multiphase perfusion computed tomography.

Eighty-six patients were included (48 good collateral status, 38 poor collateral status). The patients with poor collateral status were more likely to have a higher total NIHSS score (18 versus 11, p < 0.001) and atrial fibrillation (65.8% versus 41.7%, p = 0.026) than patients with good collateral flow. In a multiple logistic regression, the NIHSS sub-items such as profound "facial palsy" (score 2 versus 0-1) and "visual field defect" (score 2 versus 0-1) were independently associated with poor collateral status.

Among the NIHSS sub-items, severe facial palsy and visual field defect were associated with poor collateral status in acute MCA stroke with M1 occlusion. Decision on whether to treat these patients endovascularly should be made more cautiously due to the possibility of a poor outcome.