Abstract T MP58: Incidence and Etiology of Punctate Infarcts in Ischemic Stroke Patients

Abstract

Background/Objective: Punctate infarcts (PI) are increasingly seen on DWI of patients with intracerebral hemorrhage (ICH) due to small vessel disease (SVD). We aimed to determine their incidence and potential causes in a large ischemic stroke (IS) cohort that had thorough etiologic workup. Methods: Consecutive patients with MRI-confirmed IS within 72 hours of onset were enrolled. Subjects had either a single high-risk embolic source (cardioembolic or large vessel disease) or no embolic source. PIs were classified by their relationship to the primary infarct as within or outside the same vascular territory. White matter disease burden (WMDB) and microbleed counts were obtained to be used as markers of severity of SVD. Multivariable regression models were constructed to assess the association between PIs and potential etiologies (embolism vs SVD). Results: We analyzed 946 IS patients, mean age 69 +/- 15 years, 46% female. We detected PI (≤5mm) in 269 (28%) subjects, 190 (71%) within the vascular territory of the primary infarct. Large-vessel atherosclerosis (p<0.001), cardioembolic source (p<0.001), higher WMDB (p=0.032) and lower systolic blood pressure (SBP, p=0.024) were independently associated with the presence of PI. While lower SBP was associated with PI in any location (p<0.05), WMDB was only associated with PI outside the vascular territory of the primary infarct (p=0.033); and large vessel atherosclerosis was only associated with PI within the vascular territory of the primary infarct (p=0.004). Conclusions: PIs occurring within the vascular territory of a larger infarct are more likely to have a proximal embolic source, but those occurring outside are more likely related to SVD. Their relatively high incidence and diverse etiologic associations in a cohort of IS patients emphasize the importance of research into their mechanisms.