What MRI scans tell us about patients with embolic strokes of unknown origin
Brian infarcts are quite common among patients with a history of embolic stroke of undetermined source (ESUS), according to new data published in Stroke.
The study's authors aimed to use MRI findings to learn more about ESUS, which are believed to make up roughly 20% or 30% of all ischemic strokes. Their analysis included 918 patients from 15 different countries who participated in the NAVIGATE ESUS trial. All patients were treated between 2014 and 2017.
Sixty-percent of patients were men, and the mean patient age was 67 years old. There was a median of 64 days between the qualifying ischemic stroke and MRI.
According to the authors, on MRI, 93% of the patients had chronic or recent visible brain infarcts. There were multiple infarcts in 70% of patients, and the infarcts involved multiple arterial territories in 62% of patients. Meanwhile, all of the remaining patients who did not have visible infarcts on their MRI scan still had infarcts reported detected on prior imaging studies.
In addition, multiple brain infarcts were seen in 68% of patients without a history of stroke or transient ischemic attack before the qualifying ESUS.
The group also found that large and/or cortical infarcts were present in 89% of patients with infarcts. In the patients who had multiple large and/or cortical infarcts, 57% had one or more involving a different vascular territory from the qualifying ESUS.
“We characterized the spectrum of brain infarction among patients with ESUS, who represent a large subset of patients with cryptogenic stroke with a presumed embolic stroke mechanism,” wrote lead author Mukul Sharma, MD, with the Population Health Research Institute in Canada, and colleagues. “Multiple brain infarcts predominated, with a median of four infarcts detected by MRI and involving multiple arterial territories. Because this sub-study MRI was completed many weeks after the qualifying ESUS in most patients, recent infarcts representing the qualifying stroke could not be reliably identified.”
Sharma et al. noted that one limitation of their work was the fact that only 13% of NAVIGATE ESUS trial participants were enrolled in this phase of the sub-study.
“However sub-study participants were generally representative of the overall trial cohort and of patients with ESUS in non-trial clinical cohorts," they wrote.
Read the full study here.