Distribution of modified Rankin scores (mRS) by dichotomized collateral scores on presentation. (A) mRS at discharge for the cohorts of patients presenting with collateral grades 3–4 vs 0–2 (4±1.7 vs 5±1.6, p<0.01, Mann–Whitney U test). (B) mRS at 90 days for the cohorts of patients presenting with collateral grades 3–4 vs 0–2 (2.5±2.3 vs 4±1.9, p=0.03, Mann–Whitney U test). Values were available for a subset of the cohort, as indicated in parentheses. For both figures, numbers in white indicate the percentage of patients within each category.