Cerebral microbleeds development after stroke thrombolysis: A secondary analysis of the THAWS randomized clinical trial.

New cerebral microbleeds developed within 36 h in 11% of the patients after intravenous thrombolysis, and they were significantly associated with mixed-distribution and ≥5 cerebral microbleeds. New cerebral microbleeds development might impede neurological improvement. Furthermore, cerebral microbleeds burden might affect the effect of alteplase.