Two recent studies, one of which was cut short due to the positive outcomes of the first study; are changing the way “wake-up strokes” are treated. The mainstream and drug of choice for acute ischemic strokes is TPA. TPA is a clot buster, or as I like to call it “a little clot bomb”. TPA initiates local fibrinolysis by binding to fibrin in a thrombus and converts entrapped plasminogen to plasmin. The FDA approved window to use TPA is within 3-4.5 hours of stroke symptoms onset. Since TPA was approved by the FDA in 1996, it seems that with each passing Stroke Guideline, neurologists are pushing the boundaries of medication utilization. If you’ve ever had the privilege of being part of the stroke team and mixed TPA for patients, you’d see how beneficial this medication is. After administration of TPA, the NIH score improves, patients regain motor function and deficits are slowly diminished. But that’s not to say that this medication doesn’t come with risk. As the pharmacist on the stroke team, it is my job to counsel patients and family members of the risk associated with TPA.
When I staffed overnight in the emergency room, wake-up strokes were a very sad and unfortunate way to end the shift. Since most of these patients were last seen normal when they went to bed over 4.5 hours ago, the stroke team was limited on what could be done pharmacologically. When I first heard the hospital would be implementing a “wake-up stroke protocol” I too was a bit hesitant. My mind flashed back at the rare instances where TPA was given within the appropriate window and unfortunately an adverse event occurred.
Upon carefully reading the studies, I came to the conclusion that extending the TPA administration window wasn’t taken lightly and multiple imagining tests had to be performed. The studies used imaging to determine how recent the stroke was by estimating the volume of irreversibly injured ischemic-core tissue. Both trials suggested beneficial outcomes for patients within 90 days, but both trials were also cut short.