How fast can acute stroke treatment become to still be reliable?

Every day roughly three new stroke suspects are rushed by ambulance to Helsinki University Hospital Emergency Department to be considered for urgent clot-busting thrombolytic therapy or thrombectomy to prevent permanent stroke caused by acute cerebral ischemia. But perilously, out of one hundred such ‘thrombolysis candidates’ only half is actually caused by this condition and the rest have other kinds of diagnoses. Despite the tremendous time-pressure, the rapid diagnoses need to be accurate.