Cerebrovascular Reactivity and Cognitive Decline in Patients With Alzheimer Disease

Abstract

Background and Purpose-The aim of this study was to explore the possible contribution of alterations in cerebral hemodynamics to the evolution of cognitive impairment in patients with Alzheimer disease (AD). Method-Fifty-three patients with AD were investigated. The evolution of cognitive decline over 12 months was evaluated by means of changes in Mini Mental State Examination (MMSE) and AD Assessment Scale for Cognition (ADAS-Cog) scores. Demographic characteristics, vascular risk profile, pharmacological treatment, and presence of white matter lesions were assessed at entry. Further, a basal evaluation of cerebrovascular reactivity to hypercapnia was measured with transcranial Doppler ultrasonography using the breath-holding index (BHI). Results-Of all the variables considered, both MMSE and ADAS-Cog changes had the highest correlation with BHI, followed by age and diabetes. After subdividing both cognitive measures reductions into bigger and smaller-thanaverage decline (2 points for MMSE; 5 points for ADAS-Cog), multiple logistic regression indicated BHI as the sole significant predictor of cognitive decline. Conclusions-These results show an association between impaired cerebral microvessels functionality and unfavorable evolution of cognitive function in patients with AD. Further research is needed to fully establish whether altered cerebral hemodynamics may be considered an independent factor in sustaining cognitive decline progression or an effect of pathological processes involved in AD.

Midlife Metabolic Profile and the Risk of Late-Life Cognitive Decline

“…For example, several reports have shown that midlife overweight and obesity increased the risk of CD, VaD, and AD in late life [12-15, 48, 49]. It is now widely accepted that vascular and metabolic risk factors play an important role in the onset and progression not only of VaD, but also of AD and other dementias [50,51]. The magnitude of the effect is wider if they are present during midlife, maybe because their biological mechanisms need a long "window period" to determine the pathological process.…”

Quantitative mapping of cerebrovascular reactivity using resting-state BOLD fMRI: Validation in healthy adults

“…The same is true for the RSFA approach (Kannurpatti et al, 2014), which we found to not be uniformly associated with standard CVR estimates. We argue the same for our parametricdeconvolution-based rs-qCVR estimates, as in many cases, such as in stroke ) and Alzheimer's disease (Silvestrini et al, 2006;Yezhuvath et al, 2012), CVR maps are used to depict local abnormalities rather than make statements regarding global differences between individuals. In such cases, it is more crucial that the spatial pattern rather than the absolute value of the CVR estimates be accurate, and therefore, calibration of the rs-fMRI CVR values is not necessary.…”

Cognitive Disorders and Dementia in CKD

“…55 Hence, impaired cerebral hemodynamics, as evaluated by transcranial Doppler ultrasonography, may reveal interesting information on the association between altered cerebrovascular hemodynamics and cognitive impairment. 56 Indeed, previous transcranial Doppler studies show a positive correlation between hemodynamic impairment and cognitive impairmentsuggesting that microvascular damage contributes to the cognitive changes observed in the early stages of dementia. 57,58 Additionally, the prevalence of traditional 2 This might explain the association between CKD and cerebrovascular disease because the latter plays the largest role in the pathogenesis of cognitive impairment in CKD patients.…”