Thrombolysis for acute stroke

To the Editor. —The Original Contribution reporting results from the European Cooperative Acute Stroke Study (ECASS) 1 begs at least three basic questions. The first concerns the puzzling statement regarding recombinant tissue plasminogen activator (rt-PA): Herniation from space-occupying edema was more frequent in the rt-PA—treated group. These data do not support the hypothesis that successful recanalization is followed by a significantly increased risk of brain edema that may require aggressive therapy for increased intracranial pressure. The fundamental objective of the rt-PA treatment in the ECASS was declared to be recanalization, and this was apparently achieved to a significant extent. If brain edema was observed to occur more frequently in the treated group—and the data of Table 5 in the article declare that Edema, herniation resulted in at least 50% greater differential neurological mortality in the target population at all time points, as well as overall—how is it that a hypothesis