Search

White matter hyperintensities (WMH) and infarcts found on magnetic resonance imaging (MR infarcts) are common biomarkers of cerebrovascular disease. In this review, we summarize the methods, publications, and conclusions stemming from the Alzheimer's Disease Neuroimaging Initiative (ADNI) related to these measures. We combine analysis of WMH and MR infarct data from across the three main ADNI cohorts with a review of existing literature discussing new methodologies and scientific findings derived from these data. Although ADNI inclusion criteria were designed to minimize vascular risk factors and disease, data across all the ADNI cohorts found consistent trends of increasing WMH volumes associated with advancing age, female sex, and cognitive impairment. ADNI, initially proposed as a study to investigate biomarkers of AD pathology, has also helped elucidate the impact of asymptomatic cerebrovascular brain injury on cognition within a cohort relatively free of vascular disease. Future ADNI work will emphasize additional vascular biomarkers. HIGHLIGHTS: White matter hyperintensities (WMHs) are common to advancing age and likely reflect brain vascular injury among older individuals. WMH and to a lesser extent, magnetic resonance (MR) infarcts, affect risk for transition to cognitive impairment. WMHs and MR infarcts are present, even among Alzheimer's Disease Neuroimaging Initiative (ADNI) participants highly selected to have Alzheimer's disease (AD) as the primary pathology. WMH burden in ADNI is greater among individuals with cognitive impairment and has been associated with AD neurodegenerative markers and cerebral amyloidosis. The negative additive effects of cerebrovascular disease appear present, even in select populations, and future biomarker work needs to further explore this relationship.

Traumatic brain injury (TBI) survivors face debilitating long-term psychosocial consequences, including social isolation and depression. TBI modifies neurovascular physiology and behavior but the chronic physiological implications of altered brain perfusion on social interactions are unknown. Adult C57/BL6 male mice received a moderate cortical TBI, and social behaviors were assessed at baseline, 3-, 7-, 14-, 30-, and 60-days post injury (dpi). Magnetic resonance imaging (MRI, 9.4T) using dynamic susceptibility contrast perfusion weighted MRI were acquired. At 60dpi mice underwent histological angioarchitectural mapping. Analysis utilized standardized protocols followed by cross-correlation metrics. Social behavior deficits at 60dpi emerged as reduced interactions with a familiar cage-mate (partner) that mirrored significant reductions in cerebral blood flow (CBF) at 60dpi. CBF perturbations were dynamic temporally and across brain regions including regions known to regulate social behavior such as hippocampus, hypothalamus, and rhinal cortex. Social isolation in TBI-mice emerged with a significant decline in preference to spend time with a cage mate. Cortical vascular density was also reduced corroborating the decline in brain perfusion and social interactions. Thus, the late emergence of social interaction deficits mirrored the reduced vascular density and CBF in regions known to be involved in social behaviors. Vascular morphology and function improved prior to the late decrements in social function and our correlations strongly implicate a linkage between vascular density, cerebral perfusion, and social interactions. Our study provides a clinically relevant timeline of alterations in social deficits alongside functional vascular recovery that can guide future therapeutics.

Background: This study aimed to investigate the factors associated with the time that community-dwelling stroke survivors spent walking. Methods: We analyzed the cross-sectional data of 1534 community-dwelling stroke survivors from the Korean National Health and Nutrition Examination Survey. Complex-sample logistic regression analyses were performed to determine the factors associated with insufficient walking time (<90 min/wk). The mean time spent walking was examined according to age, sex, resistance exercise level, and self-reported disability using complex-sample general linear models. Results: Women (odds ratio [OR] 1.5; 95% confidence interval [CI], 1.0–2.3), current smokers (OR 1.7; 95% CI, 1.1–2.8), insufficient resistance exercise (OR 2.3; 95% CI, 1.5–3.5), and those with rural residences (OR 1.4; 95% CI, 1.0–1.9) were independently associated with insufficient walking time. The mean time spent walking was significantly lower in older adults aged ≥65 years than in young adults aged <65 years (200.0 ± 42.0 min/wk vs 287.2 ± 36.6 min/wk, P =.002), in women than in men (200.9 ± 44.9 vs 286.2 ± 37.7 min/wk, P =.027), and in individuals engaging in insufficient resistance exercise compared with those engaging in sufficient resistance exercise (203.2 ± 36.2 vs 283.9 ± 43.0 min/wk, P =.008). The mean walking time did not vary according to the presence of self-reported disabilities. Conclusions: Environmental and personal factors are associated with insufficient walking time in community-dwelling stroke survivors. [ABSTRACT FROM AUTHOR]