Antemortem MRI findings associated with microinfarcts at autopsy

Background and Purpose-Small cerebellar infarct cavities have been recently found on magnetic resonance imaging (MRI) to preferentially involve the cerebellar cortex, but epidemiological studies are lacking. We aimed to determine the prevalence and risk factor profiles of cerebellar cortical infarct cavities (≤1.5 cm) as well as their association with MRI markers of cerebrovascular disease and functioning. Methods-We analyzed the 1.

Section: Discussionsupporting

confidence: 76%

Cerebellar Cortical Infarct Cavities

Cocker¹,

Kloppenborg²,

Graaf³

et al. 2015

“…Microinfarcts are the most attractive candidate lesion fitting that description 48–52 . Clinical-pathological studies 17, 49 support an association between microinfarcts and brain volume loss, justifying our use of cortical volume as the indicator of the covert microscopic process.…”

Section: Discussionmentioning

confidence: 93%

Vascular Imaging Abnormalities and Cognition

Knopman

Griswold

Lirette

et al. 2015

136

Background and Purpose The relationships between cerebrovascular lesions visible on imaging and cognition are complex. We explored the possibility that cerebral cortical volume mediated the relationship. Methods 1906 non-demented participants (59% women; 25% African-American; mean age 76.6 years) in the Atherosclerosis Risk in Communities (ARIC) study underwent cognitive assessments, risk factor assessments, and quantitative MR imaging for white matter hyperintensities (WMH) and infarcts. The Freesurfer imaging analysis pipeline was used to determine regional cerebral volumes. We examined associations of cognitive domain outcomes with cerebral volumes (hippocampus, and separate groups of posterior and frontal cortical regions of interest (ROI)) and cerebrovascular imaging features (presence of large or small cortical/subcortical infarcts and WMH volume). We performed mediation pathway analyses to assess the hypothesis that hippocampal and cortical volumes mediated associations between cerebrovascular imaging features and cognition. Results In unmediated analyses, WMH and infarcts were both associated with worse psychomotor speed/executive function (PS/EF). In mediation analyses, WMH and infarcts associations on PS/EF were significantly attenuated, but not abolished, by the inclusion of the posterior cortical ROI volume in the models, and the infarcts on PS/EF association was attenuated, but not abolished, by inclusion of the frontal cortical ROI volume. Conclusions Both WMH and infarcts were associated with cortical volume, and both lesions were also associated with cognitive performance, implying shared pathophysiological mechanisms. Although cross-sectional, our findings suggest that WMH and infarcts could be proxies for clinically covert processes that directly damage cortical regions. Microinfarcts are one candidate for such a clinically covert process.

“…CMIs and higher WMH volume have been associated previously, 1,2 although recent studies, both at autopsy and on 7T MRI, could not consistently reproduce this association. [6][7][8] This study has some limitations. The sensitivity of 1 mm 3 3T MRI is limited, and small CMIs may be left undetected.…”

Section: Discussionmentioning

confidence: 96%

Cortical Microinfarcts Detected In Vivo on 3 Tesla MRI

Dalen

Scuric

Veluw

et al. 2015

Background and Purpose— Cortical microinfarcts (CMIs) are a common postmortem finding associated with vascular risk factors, cognitive decline, and dementia. Recently, CMIs identified in vivo on 7 Tesla MRI also proved retraceable on 3 Tesla MRI. Methods— We evaluated CMIs on 3 Tesla MRI in a population-based cohort of 194 nondemented older people (72–80 years) with systolic hypertension. Using a case–control design, participants with and without CMIs were compared on age, sex, cardiovascular risk factors, and white matter hyperintensity volume. Results— We identified 23 CMIs in 12 participants (6%). CMIs were associated with older age, higher diastolic blood pressure, and a history of recent stroke. There was a trend for a higher white matter hyperintensity volume in participants with CMIs. Conclusions— We found an association of CMIs with clinical parameters, including age and cardiovascular risk factors. Although the prevalence of CMIs is relatively low, our results suggest that the study of CMIs in larger clinical studies is possible using 3 Tesla MRI. This opens the possibility of large-scale prospective investigation of the clinical relevance of CMIs in older people.