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.
"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)). "
[Show abstract][Hide abstract] 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.
"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. "
"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). "
[Show abstract][Hide abstract] 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 · 3.57 Impact Factor
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