Impaired Cerebral Vasomotor Reactivity in Alzheimer’s Disease

Abstract

Background Recent studies have shown that cerebral vascularity may be impaired in Alzheimer's disease. Cerebral vasomotor reactivity could be an important biomarker for this pathology. Aims The aim of this study was to investigate the alterations in cerebral vascular motor reactivity in Alzheimer's disease subjects and to associate these changes with their cognitive scores. Methods We recruited subjects with a diagnosis of Alzheimer's disease and healthy controls. Demographic, clinical, imaging, and cognitive test were obtained. Then all participants performed a cerebral vascular motor reactivity test with 7% CO2 and cerebral blood flow velocities (CBFV) were recorded with transcranial doppler ultrasound before and after the test. Results We recruited 45 subjects, 26 (21 female) Alzheimer's disease participants and 19 (15 female) healthy controls. There were no differences in baseline cerebral blood flow velocities between the groups. After the cerebral vasomotor reactivity test, absolute mean difference in mean CBFV (ΔCBFV-m) was 8.70±4.14 versus 4.81±6.96 (p<0.01), respectively. Calculated percentage of change (%CVMR) was lower in the AD group 7.45±18.25 versus 23.29±17.48, and there was a positive but weak correlation with mini-mental scores (ρ=0.337, p=0.023). Conclusions In this study, Alzheimer's disease subjects showed significant changes in all absolute cerebral blood flow velocities after the cerebral vasomotor reactivity test with CO2, but only diastolic phase responses were statistically significant. There was a positive but weak correlation between cerebral vasomotor reactivity and cognitive scores. Further studies are needed to investigate these effects in larger Latin-American samples.

Cerebral vasomotor reactivity across the continuum of subjective cognitive impairment, amnestic mild cognitive impairment and probable Alzheimer's dementia: A transcranial Doppler and PET/MRI study

“…Many previous studies have shown that cerebral vasomotor reactivity with breath-holding, CO 2 inhalation or acetazolamide injection is impaired in Alzheimer's dementia. 27–34 The degree of this impairment has been correlated well with clinical disease severity as assessed by the MMSE. 27,31 A recent study has shown an inverse relationship between cerebrospinal fluid amyloid β42 level and BHI.…”

Age‐related changes in cerebrovascular health and their effects on neural function and cognition: A comprehensive review

“…In mice, age‐dependent impairment of neurovascular coupling in the hippocampus correlated with reduced performance on a spatial memory task (Lourenço et al., 2018). There is also a wealth of research relating CVR impairment to age‐related cerebral pathologies, including mild cognitive impairment and Alzheimer's Disease (Alwatban et al., 2019; Bär et al., 2007; Cantin et al., 2011; Chen, 2018; Glodzik et al., 2013; Gongora‐Rivera et al., 2018; Heun et al., 1994; Kalaria, 2010; Kelleher & Soiza, 2013; Richiardi et al., 2015; Sánchez‐Catasús et al., 2017; Silvestrini et al., 2006; Viticchi et al., 2012; Yezhuvath et al., 2012). Overall, this research suggests that age‐related declines in CVR are mostly present in the temporal lobe, although future work will help to confirm and clarify the details of the effects of age on regional CVR and cognition.…”

Cerebrovascular Hemodynamics in Cognitive Impairment and Dementia: A Systematic Review and Meta-Analysis of Transcranial Doppler Studies

“…A total of 35 studies [14‒16, 19‒21, 27‒55] were included in the review and meta-analysis after full-text review of 86 articles, as shown in Figure 1. Reasons for exclusion of studies that did not fulfill the eligibility criteria are shown in online supplementary material 2.…”

“…The general characteristics of the included studies are shown in Table 1 [ 40 ], [ 19 ], [ 51 ], [ 38 ], [ 48 ], [ 52 ], [ 20 ], [ 41 ], [ 42 ], [ 43 ], [ 14 ], [ 44 ], [ 55 ], [ 27 ], [ 34 ], [ 45 ], [ 53 ], [ 28 ], [ 46 ], [ 16 ], [ 49 ], [ 29 ], [ 30 ], [ 31 ], [ 47 ], [ 39 ], [ 32 ], [ 21 ], [ 54 ], [ 37 ], [ 33 ], [ 50 ], [ 15 ], [ 36 ], [ 35 ]. Studies included in the meta-analysis were published between 1989 and 2021.…”

“…Quality assessments of the included studies according to the CEBM checklist designed for cross-sectional studies are shown in Table 2 [ 40 ], [ 19 ], [ 51 ], [ 38 ], [ 48 ], [ 52 ], [ 20 ], [ 41 ], [ 42 ], [ 43 ], [ 14 ], [ 44 ], [ 55 ], [ 27 ], [ 34 ], [ 45 ], [ 53 ], [ 28 ], [ 46 ], [ 16 ], [ 49 ], [ 29 ], [ 30 ], [ 31 ], [ 47 ], [ 39 ], [ 32 ], [ 21 ], [ 54 ], [ 37 ], [ 33 ], [ 50 ], [ 15 ], [ 36 ], [ 35 ], with an unclear risk of bias for most of the included studies. The certainty in the pooled estimates was evaluated using GRADE, shown in Tables 3 – 6 .…”