Timing of thrombolysis for acute ischemic stroke: "timing is everything" or "everyone is different".

It is indisputable that in the first 2 to 3 hours of an acute ischemic, the best strategy to maximize recovery is robustly time-based and depends on getting the artery open as soon as possible. The second law of thermodynamics and the underappreciated effect of clot consistency and size must be accounted for in our efforts to minimize time to recanalization within the first 2 to 3 hours. It is also clear that at later time intervals, beyond 4.5 hours, few patients completely recover even with sustained complete recanalization, and that the ability to recover depends more on physiologic tissue issues than on the duration of the occlusion. Clinical factors as well as imaging should be used to select patients who may benefit from delayed attempts at reperfusion.