Collateral response modulates the time-penumbra relationship in proximal arterial occlusions

Abstract

OBJECTIVE: While clinical benefit from thrombolysis decreases with increase in time from stroke onset, the relationship of acute physiologic tissue compartments and collateral response to stroke onset time remains unclear. METHODS: We studied consecutive patients with proximal arterial occlusions (n = 355) with whole-brain perfusion CT with CT angiography within 6 hours of stroke onset. Penumbra and core were defined using voxel-based thresholds. Tissue mismatch was defined as the ratio of penumbra to core. Collateral scores were assessed using a previously validated visual score. RESULTS: Mean (SD) age was 72.1 (12.4) years, median (interquartile range) NIH Stroke Scale score 16 (4), mean (..