Abstract TP248: Distribution and Number of Cerebral Microhemorrhages Differ According to Ischemic Stroke Subtype

Abstract

Introduction: Cerebral microhemorrhages/microbleeds (CMBs) are foci of hemosiderin deposition that appear as well-circumscribed hypointensities on T2*-weighted gradient echo magnetic resonance imaging(1). They are a bio marker of small vessel disease but may also be seen as a consequence of thromboembolism to the brain and are commonly seen in the wake of acute ischemic stroke(2). We sought to understand the relationship between CMB burden and distribution and ischemic stroke subtype. Methods: We undertook a retrospective observational study of patients admitted for management of acute ischemic stroke via clinical data archived as part of an institutional quality improvement project. Patient information was gathered including demographics, past medical history, treatment and ischemic stroke subtype. T2*/GRE imaging was inspected and the presence or absence, number and distribution of definite CMBs (according to Microbleed Anatomic Rating Scale (MARS) criteria(3) was documented for each patient. Results: 695 patients with acute ischemic stroke confirmed on imaging had T2*/GRE imaging of adequate quality. The mean age in our population was 71.14 (+-15.28). 22.3% of the population had CMBs and the average number of CMBs per person was 0.66. The mean number of CMBs was higher in patients with stroke of small vessel etiology (mean of 1.97) compared with the group as a whole and this difference persisted after adjusting for age and hypertension (p=0.024). Patients with stroke of cardioembolic etiology had a higher proportion of lobar microhemorrhages (11.83%) compared with those with stroke of small vessel etiology (6.90%) though this difference did not persist after adjusting for age. Discussion: Distribution and number of CMBs differ based on stroke pathophysiology. CMB pattern may aid in distinguishing strokes of small vessel etiology from other ischemic stroke subtypes.