The Integrity of the Corpus Callosum Mitigates the Impact of Blood Pressure on the Ventral Attention Network and Information Processing Speed in Healthy Adults

Abstract

Hypertension is a risk factor for cognitive impairment in older age. However, evidence of the neural basis of the relationship between the deterioration of cognitive function and elevated blood pressure is sparse. Based on previous research, we speculate that variations in brain connectivity are closely related to elevated blood pressure even before the onset of clinical conditions and apparent cognitive decline in individuals over 60 years of age. Forty cognitively healthy adults were recruited. Each received a blood pressure test before and after the cognitive assessment in various domains. Diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (rsfMRI) data were collected. Our findings confirm that elevated blood pressure is associated with brain connectivity variations in cognitively healthy individuals. The integrity of the splenium of the corpus callosum is closely related to individual differences in systolic blood pressure. In particular, elevated systolic blood pressure is related to resting-state ventral attention network (VAN) and information processing speed. Serial mediation analyses have further revealed that lower integrity of the splenium statistically predicts elevated systolic blood pressure, which in turn predicts weakened functional connectivity (FC) within the VAN and eventually poorer processing speed. The current study sheds light on how neural correlates are involved in the impact of elevated blood pressure on cognitive functioning.

Association of blood pressure with cognitive function at midlife: a Mendelian randomization study

“…Indeed, regional white matter integrity is lower among individuals with higher BP, regardless of hypertension status [38]. In a recent study of cognitively healthy older adults, the relationship between SBP and poorer processing speed appeared to be mediated by functional connectivity of the right superior temporal gyrus within the ventral attention network (VAN) [39]. This is consistent with a previous report showing that variation in structural organization within the frontoparietal system, which comprises the VAN, is associated with differences in attentional functions, including visual short-term memory capacity, processing speed, and spatial bias [40].…”

Visual and visuomotor interhemispheric transfer time in older adults

“…Functional measures of the posterior CC could be an important measure for tracking changes in the aging brain that may deviate from the trajectory of normal development. For example, lower splenium integrity has been linked to increases in hypertension in older adults (Wong, Ma, & Lee, 2017b), which in turn is associated with increased risk of coronary heart disease and cardiovascular problems later in life (Rigaud & Forette, 2001).…”

“…The evidence from neuroimaging suggests that differential patterns of degeneration in the CC may be related to typical and pathological aging (Bastin et al, 2010;Penke et al, 2010;Salat et al, 2005). For example, white matter integrity in the posterior section of the CC has been related to processing speed, hypertension and cognitive abilities in older adults (Penke et al, 2010;Wong, Ma, & Lee, 2017a). Therefore, rigorous measurement of the CC and its associated functions has the potential to provide important information about how the brain ages successfully and unsuccessfully.…”

Shifts in Audiovisual Processing in Healthy Aging

“…It has been well established that performance of aging adults decline on a number of cognitive tasks spanning multiple domains including working memory [103, 104], visuospatial abilities [105], and speed of information processing [106, 107]. Furthermore, more recent work has also highlighted age-related increases in intra-individual variability on a number of these tasks [108-110].…”