Coming to us from the Department of Common Sense: don’t give tPA to stroke patients who already have intracranial hemorrhage. There’s a little more subtlety here, of course, because in this instance, we’re dealing with cerebral microbleeds – tiny foci of angiographic damage visualized only on MRI.
These authors performed a pooled and individual-patient meta-analysis of those undergoing MRI prior to treatment with intravenous thrombolysis. When stratified by CMB burden, arbitrarily divided into “none”, “1-10”, and “>10”, the obvious is … obvious: patients who are already bleeding are more likely to continue bleeding. In the unadjusted raw numbers, patients with no CMB had a symptomatic intracranial hemorrhage rate of 4.3%, those with 1-10 CMB had 6.1%, and those with >10 had 40.0%.
There are many technical limitations inherent to the retrospective nature of their study, as well as likely other confounding variables – but, the basic gist: our current practice relying only on non-contrast CT likely misses an important safety indicator in the setting of tPA use.
“Risk of Symptomatic Intracerebral Hemorrhage After Intravenous Thrombolysis in Patients With Acute Ischemic Stroke and High Cerebral Microbleed Burden”
https://www.ncbi.nlm.nih.gov/pubmed/27088650