Who've absolutely blocked arteries because the human body may have produced collateral circulation that bypasses the blockage People obtaining stroke signs might be candidates for treatment with clot-busting medicine or thrombolytics, although the treatment need to be initiated within 4.5 hrs from the main onset of such signs or symptoms. https://www.sgvascularctr.com/treating-carotid-artery-disease-an-overview-of-treatment-options-in-singapore/