Background and purpose: Stroke severity in cases of hyperacute carotid ischemic stroke may be related to site of arterial occlusion. We evaluated the relationships between National Institutes of Health Stroke Scale (NIHSS) scores and findings on intra-arterial digital subtraction angiograms (IA-DSA) of patients with ischemic stroke within 6 hr of stroke onset.
Methods: A total of 43 consecutive patients (38 men and five women; mean age, 69.4 +/- 8.7 years) with ischemic stroke in the carotid territory underwent IA-DSA within 6 hr of stroke onset. Baseline NIHSS score was assessed immediately before IA-DSA. Patients were divided into four groups according to site of arterial occlusion: 1) the internal carotid artery (ICA group, n = 10); 2) stem of the middle cerebral artery or stem of the anterior cerebral artery (Stem group, n = 14); 3) branches of middle cerebral artery or anterior cerebral artery (Branch group, n = 11); and 4) no arterial occlusion (Normal group, n = 8).
Results: Mean (+/-SD) NIHSS score was 14.7 +/- 7.4. The interval from stroke onset to IA-DSA study was 205 +/- 76 min. NIHSS score was higher in the ICA group (median, 23; range, 6-32) than in the Branch (median, 17; range, 11-25; P =.02) or Normal (median, 15; range, 2-17; P <.001) groups but was not higher than in the Stem group (median, 6; range, 1-11; P =.73). Sensitivity-specificity curve analysis suggested an NIHSS score > or = 10 as indicative of arterial occlusion of the carotid system. A total of 96.9% of patients with NIHSS scores > or = 10 displayed arterial occlusion, and 63.6% of patients with NIHSS scores <10 displayed no arterial occlusion.
Conclusion: NIHSS score is related to site of arterial occlusion in cases of hyperacute carotid ischemic stroke. An NIHSS score of 10 seems to represent the cut-off for discriminating between patients with arterial occlusion and patients without.