Vascular health and longitudinal changes in brain and cognition in middle-aged and older adults
ABSTRACT 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.
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- "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. "
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. Copyright © 2015 Elsevier B.V. All rights reserved.Behavioural brain research 03/2015; 287. DOI:10.1016/j.bbr.2015.03.018 · 3.39 Impact Factor
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- "Most of the studies aimed at understanding processing of acoustical signals in presbycusis state that the mental condition of the volunteers is adequate for their age; however, these statements are mostly based on self-reported memory and cognitive abilities (Aine et al. 2010). Therefore, the probability that volunteers have subclinical cognitive pathologies is present, especially in cases of vascular risk factors (Raz et al. 2007), hypertension (Qiu et al. 2005), type 2 diabetes (Manschot et al. 2006), or high serum cholesterol (Schmidt et al. 2000). "
ABSTRACT: Aging is accompanied by the deterioration of hearing that complicates our understanding of speech, especially in noisy environments. This deficit is partially caused by the loss of hair cells as well as by the dysfunction of the stria vascularis. However, the central part of the auditory system is also affected by processes accompanying aging that may run independently of those affecting peripheral receptors. Here, we review major changes occurring in the central part of the auditory system during aging. Most of the information that is focused on age-related changes in the central auditory system of experimental animals arises from experiments using immunocytochemical targeting on changes in the glutamic-acid-decarboxylase, parvalbumin, calbindin and calretinin. These data are accompanied by information about age-related changes in the number of neurons as well as about changes in the behavior of experimental animals. Aging is in principle accompanied by atrophy of the gray as well as white matter, resulting in the enlargement of the cerebrospinal fluid space. The human auditory cortex suffers not only from atrophy but also from changes in the content of some metabolites in the aged brain, as shown by magnetic resonance spectroscopy. In addition to this, functional magnetic resonance imaging reveals differences between activation of the central auditory system in the young and old brain. Altogether, the information reviewed in this article speaks in favor of specific age-related changes in the central auditory system that occur mostly independently of the changes in the inner ear and that form the basis of the central presbycusis.Cell and Tissue Research 01/2015; 361(1). DOI:10.1007/s00441-014-2107-2 · 3.33 Impact Factor
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- "Over five years, the fastest cortical degeneration was observed in the prefrontal cortex and the hippocampus. Significantly, fluid intelligence correlated with white matter hyperintensities (WMH) burden and declined with WMH progression whilst working memory declined with temporal lobe degeneration (Raz et al., 2007). MetS has also been associated with general cognitive decline (Yaffe et al., 2009) and amnestic mild cognitive impairment (a-MCI) (Feng et al., 2013) although not always (Solfrizzi et al., 2010). "
ABSTRACT: ABSTRACT Background: An association between metabolic syndrome (MetS) and disturbances in neurocognitive function has been identified in Caucasians but the nature and extent of impaired cognition in Asian MetS patients, who may be at greater risk of degenerative cognitive decline, remains unspecified. Methods: A cross-sectional study was conducted at the National University Hospital of Singapore. Participants were recruited from a diabetes clinic at the National University Hospital. Fifty-three patients who met MetS criteria and 44 clinical controls were recruited. All participants were 55 years and above and community ambulant. Neurocognitive function was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). CANTAB performances between MetS and control groups were examined with analysis of variance (ANOVA) and the relative contributions of vascular risk, and intrademographic factors on CANTAB scores were dilineated with stepwise regression analyses. Results: Participants with MetS consistently performed significantly worse than controls across all CANTAB subtests. Education and Chinese race were found to be potential protective factors. Conclusions: Executive and memory impairment is present in Asian patients with midlife MetS who may be particularly vulnerable to the detrimental impact of MetS in midlife.International Psychogeriatrics 05/2014; 26(8):1-12. DOI:10.1017/S104161021400057X · 1.89 Impact Factor