MY CONTENT

This article addresses the importance of collateral circulation in preserving the tissues contained within the ischemic penumbra in patients with acute stroke treated with IV thrombolysis. The authors evaluated not only the presence of collaterals but also their quality. They quantified a normalized collateral circulation deficit and correlated it with parameters thought to affect its quality, such as baseline NIHSS score, volume of DWI abnormalities, and modified Rankin scale at 3 months. The normalized collateral circulation deficit correlated with NIHSS, lesion volume as seen on DWI, and recanalization at 24 hours. Full recanalization as well as the probability of full recanalization also correlated with the normalized collateral circulation deficit. Thus, this index is a good predictor of recanalization and outcome in patients with acute stroke treated with IV thrombolysis.