Abstract WP74: Right Hemispheric Infarcts Have Higher CT Perfusion Penumbra Volume for Given NIH Stroke Scale: Results From BEST Prospective Cohort Study

Abstract

Introduction: Right hemispheric strokes have a higher average infarct volume than left hemisphere strokes for the same severity of NIH stroke scale (NIHSS). This phenomenon, although well documented by CT and MRI based volume calculation of final infarct volume, is yet to be confirmed with automated acute CT/MR perfusion imaging in acute large vessel stroke setting. Additionally, penumbral volumes have not been well studied with regard to laterality of stroke. Methods: Data from the BEST prospective cohort study, a multicenter study that enrolled consecutive patients with anterior cerebral large vessel occlusion undergoing endovascular treatment were used for analysis. We determined the correlation between baseline NIHSS and CTP penumbra volume (CTPp; total volume of Tmax>6sec) as well as core infarct volume (CTPc) for right sided and left sided strokes. We also determined the difference in CTPp and CTPc between right and left sided stroke for every 5-point increase in the baseline NIHSS. Results: Of the 443 enrolled patients, 165 (82 female, median age 69 [IQR 57, 81]) had complete data for baseline CTPp and CTPc; one patient with bilateral strokes was excluded. Median CTPp for right sided (n=74) strokes was 127.5 cc [IQR 83, 167] and for left sided (n=90) strokes was 93.0 cc [IQR 62, 155]. Median CTPc for right sided strokes was 15.0 cc [IQR 0, 35] and that for left sided strokes was 6.5 cc [0, 24]. After adjusting for baseline NIHSS, right sided strokes had significantly higher CTPp than did left sided (p=0.001), but no evidence of laterality for CTPc was observed (p=0.09). The correlation coefficient for NIHSS and CTPp was 0.23 and 0.33, and that for CTPc was 0.16 and 0.19 for right and left side, respectively. Highest difference in CTPp between sides was observed at NIHSS 16-25 (table). Conclusions: Right hemispheric strokes have higher CTPp but not CTPc as compared to the left. For a given NIHSS, right hemispheric strokes may have larger salvageable tissue.