Vascular health and longitudinal changes in brain and cognition in middle-aged and older adults
Institute of Gerontology, Wayne State University, Detroit, Michigan, United States Neuropsychology
(Impact Factor: 3.27).
03/2007; 21(2):149-57. DOI: 10.1037/0894-4188.8.131.52
The impact of vascular health on the relations between structural brain changes and cognition was assessed in a longitudinal study of 46 adults, 23 of whom remained healthy for 5 years and 23 of whom had hypertension at baseline or acquired vascular problems during follow-up. At both measurement occasions, the volume of white matter hyperintensities (WMH) and regional brain volumes correlated with age. In 5 years, WMH volume more than doubled in the vascular risk group but did not increase in healthy participants. The frontal lobes had the highest WMH load at baseline and follow-up; the parietal WMH showed the greatest rate of expansion. In the vascular risk group, systolic blood pressure at follow-up correlated with posterior WMH volume. The fastest cortical shrinkage was observed in the prefrontal cortex and the hippocampus. Fluid intelligence correlated with WMH burden and declined along with faster WMH progression. In the vascular risk group, WMH progression and shrinkage of the fusiform cortex correlated with decline in working memory. Thus, poor vascular health contributes to age-related declines in brain and cognition, and some of the age-related declines may be limited to persons with elevated vascular risk.
Available from: Sarah Szymkowicz
- "For example, men and women have been found to have different trajectories of age-related structural changes (Murphy et al., 1996;Coffey et al., 1998;van Velsen et al., 2013). Demographic and clinical variables such as education, vascular disease, and genetic variation may also moderate the relationships of age with brain structure (Decarli et al., 1999;Swan et al., 2000;Seshadri et al., 2004;Raz et al., 2005Raz et al., , 2007bLuders et al., 2006;Brundel et al., 2010;Debette et al., 2011;Leritz et al., 2011;Villeneuve et al., 2014;Gonzalez et al., 2015) but have not always been accounted for in previous studies. Additionally, findings from cross-sectional studies may differ from longitudinal studies, as there is evidence that some regions show no cross-sectional differences but do change over time (Fjell et al., 2014). "
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ABSTRACT: Age is associated with reductions in surface area and cortical thickness, particularly in prefrontal regions. There is also evidence of greater thickness in some regions at older ages. Non-linear age effects in some studies suggest that age may continue to impact brain structure in later decades of life, but relatively few studies have examined the impact of age on brain structure within middle-aged to older adults. We investigated age differences in prefrontal surface area and cortical thickness in healthy adults between the ages of 51 and 81 years. Participants received a structural 3-Tesla magnetic resonance imaging scan. Based on a priori hypotheses, primary analyses focused on surface area and cortical thickness in the dorsolateral prefrontal cortex, anterior cingulate cortex, and orbitofrontal cortex. We also performed exploratory vertex-wise analyses of surface area and cortical thickness across the entire cortex. We found that older age was associated with smaller surface area in the dorsolateral prefrontal and orbitofrontal cortices but greater cortical thickness in the dorsolateral prefrontal and anterior cingulate cortices. Vertex-wise analyses revealed smaller surface area in primarily frontal regions at older ages, but no age effects were found for cortical thickness. Results suggest age is associated with reduced surface area but greater cortical thickness in prefrontal regions during later decades of life, and highlight the differential effects age has on regional surface area and cortical thickness.
Available from: Barbara Spano
- "These structural abnormalities are correlated with poorer executive performance (e.g., Nagahama et al., 1997; Gunning-Dixon and Raz, 2003; Van Petten et al., 2004; Raz et al., 2007; Cardenas et al., 2011). For example, increased WMA and smaller anterior cingulate cortex volume are associated with poorer performance on the Stroop test and fluid intelligence tasks (e.g., Raz et al., 2007; Elderkin-Thompson et al., 2008, but see Salthouse (2011)). "
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ABSTRACT: Age is known to affect prefrontal brain structure and executive functioning in healthy older adults, patients with neurodegenerative conditions and TBI. Yet, no studies appear to have systematically investigated the effect of age on cognitive performance in patients with focal lesions. We investigated the effect of age on the cognitive performance of a large sample of tumour and stroke patients with focal unilateral, frontal (n=68), or non-frontal lesions (n=45) and healthy controls (n=52). We retrospectively reviewed their cross sectional cognitive and imaging data. In our frontal patients, age significantly predicted the magnitude of their impairment on two executive tests (Raven's Advanced Progressive Matrices, RAPM and the Stroop test) but not on nominal (Graded Naming Test, GNT) or perceptual (Incomplete Letters) task. In our non-frontal patients, age did not predict the magnitude of their impairment on the RAPM and GNT. Furthermore, the exacerbated executive impairment observed in our frontal patients manifested itself from middle age. We found that only age consistently predicted the exacerbated executive impairment. Lesions to specific frontal areas, or an increase in global brain atrophy or white matter abnormalities were not associated with this impairment. Our results are in line with the notion that the frontal cortex plays a critical role in aging to counteract cognitive and neuronal decline. We suggest that the combined effect of aging and frontal lesions impairs the frontal cortical systems by causing its computational power to fall below the threshold needed to complete executive tasks successfully.
Available from: Prapti Gautam
- "These relationships also survived corrections for cortical volume and thickness and were independent of age and sex, suggesting that despite sharing a large proportion of variance with volume and thickness, there is a unique relationship between cognitive function and cortical gyrification in the lateral frontal cortex. Our results in this population are also relevant in the context of cognitive aging, as there are indications that the cognitive difficulties that are observed in older adulthood are related to brain  and cognitive health   much earlier in the lifespan. Given the age-related vulnerability of the frontal cortex to volume decrease and its important role in cognitive aging, it is of value to document if prefrontal gyrification relates to cognitive function, especially in a midlife population who are still underinvestigated in the literature. "
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ABSTRACT: Across species, greater cortical gyrification, or folding of the cortex, has been shown to be associated with higher cognitive abilities and is thought to reflect an evolutionary process aimed at maximizing the number of cerebral computational units while minimizing the energy and communication costs of larger brains. Relatively little is known about the significance of individual variation in gyrification in humans and how it relates to other aspects of cerebral structure and function. In the current study, we examined relationships between cortical gyrification and i) cortical volume, ii) cortical thickness, and iii) executive functions. Participants were middle-aged healthy adults (44-48 years old, n=396) in a community-based sample. T1-weighted 3D structural magnetic resonance imaging scans were acquired in a Fast Field Echo sequence. Cortical gyrification, volume, and thickness were measured through the semi-automated software FreeSurfer. Results showed that cortical gyrification was strongly and positively related to cortical volume, but was negatively related to cortical thickness in many regions of the cortex. In addition, frontal gyrification was positively related to performance in working memory and mental flexibility tasks. These results support the view that greater cortical gyrification is related both to bigger brain volumes and better cognitive function, but not to greater cortical thickness. The results provide evidence of functional relevance of cortical gyrification development, and show that it can be a useful index to investigate structure-cognition relationships.
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