Dr. Siegler and colleagues evaluated outcomes of mechanical thrombectomy (MT) vs medical management in a multinational cohort of 554 patients with a prestroke modified Rankin Scale (mRS) score of 2–4 and anterior circulation large vessel occlusion, treated 6–24 hours from the time last seen well. They found that MT was associated with higher odds of return to prestroke mRS by 90 days. In response, Drs. Bruno and Nichols noted that there is no clear guidance for scoring a baseline or prestroke mRS (indeed, the mRS was originally intended for evaluating poststroke outcomes). They also contend that scoring a 90-day mRS in patients with prestroke disability is not clearly defined. Responding to these comments, the authors agree that the prestroke mRS has important limitations, but point to the fact that this measure has been used in various studies, including in the selection of patients for interventional stroke trials. They correctly note that current guidelines to score the poststroke mRS are intended simply to score how the patient is functioning at the time in question, rather than making judgments about how they are doing in relation to their prestroke status. Overall, this exchange demonstrates important nuances in the assessment of prestroke status and poststroke outcomes in patients with prestroke disability—a population that has been poorly represented in acute stroke trials.
