Cerebrovascular Function in Aging and Dementia: A Systematic Review of Transcranial Doppler Studies

Keage, Hannah A.D.; Churches, Owen; Köhler, Manfred; Pomeroy, Danielle; Luppino, Rocco; Bartolo, Michelle L.; Elliott, Scott

doi:10.1159/000339234

Cited by 69 publications

(69 citation statements)

References 110 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was observed that the first branch in the MABP-CBFV relationship exhibited the traditional high-pass dynamic characteristic that is consistently observed in TFA [1,3,13,24,25,29]. The corresponding ANF is mainly rectilinear and was shown to dominate the linear dynamic MABP-CBFV relationship.…”

Section: Discussionmentioning

confidence: 70%

“…As mentioned, a commonly used model is the compartmental model of the cerebral circulation [6,10,13,19-21,28,31,32]. In this approach, the cerebral vasculature is summarized by the interconnection of lumped parameters representing vascular resistance and compliance.…”

Section: Modeling Methodsmentioning

confidence: 99%

“…Quantitative assessment of cerebral autoregulation (CA) and vasomotor reactivity (VR) in humans serves as an important modeling goal, due to the observed association between cerebrovascular structure and function in the outcome of head injury, stroke, vascular dementia, Alzheimer's disease, and other forms of cognitive impairment [2,4,5,8,13,22,29]. The availability of non-invasive measurements of relevant hemodynamic data has provided a means to obtain objective measures of CA and VR.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Compartmental and Data-Based Modeling of Cerebral Hemodynamics: Nonlinear Analysis

Henley

Shin

Zhang

et al. 2017

IEEE Trans. Biomed. Eng.

View full text Add to dashboard Cite

Objective As an extension to our study comparing a putative compartmental and data-based model of linear dynamic cerebral autoregulation (CA) and CO2-vasomotor reactivity (VR), we study the CA-VR process in a nonlinear context. Methods We use the concept of Principal Dynamic Modes (PDM) in order to obtain a compact and more easily interpretable input-output model. This in silico study permits the use of input data with a dynamic range large enough to simulate the classic homeostatic CA and VR curves using a putative structural model of the regulatory control of the cerebral circulation. The PDM model obtained using theoretical and experimental data are compared. Results It was found that the PDM model was able to reflect accurately both the simulated static CA and VR curves in the Associated Nonlinear Functions (ANFs). Similar to experimental observations, the PDM model essentially separates the pressure-flow relationship into a linear component with fast dynamics and nonlinear components with slow dynamics. In addition, we found good qualitative agreement between the PDMs representing the dynamic theoretical and experimental CO2-flow relationship. Conclusion Under the modeling assumption and in light of other experimental findings, we hypothesize that PDMs obtained from experimental data correspond with passive fluid dynamical and active regulatory mechanisms. Significance Both hypothesis-based and data-based modeling approaches can be combined to offer some insight into the physiological basis of PDM model obtained from human experimental data. The PDM modeling approach potentially offers a practical way to quantify the status of specific regulatory mechanisms in the CA-VR process.

show abstract

Section: Discussionmentioning

confidence: 70%

Section: Modeling Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Compartmental and Data-Based Modeling of Cerebral Hemodynamics: Nonlinear Analysis

Henley

Shin

Zhang

et al. 2017

IEEE Trans. Biomed. Eng.

View full text Add to dashboard Cite

show abstract

“…7 In addition, lower vasoreactivity correlates with higher volumes of cerebral white matter lesions, 8 which are strongly associated with cognitive decline and dementia. 9 Several small cross-sectional studies have found CVR to be reduced in patients with dementia or mild cognitive impairment compared with healthy controls, [10][11][12] but its impact on cognitive decline and the risk of dementia is uncertain.…”

mentioning

confidence: 99%

Cerebral Vasoreactivity, Apolipoprotein E, and the Risk of Dementia

Wolters

Bruijn

Hofman

et al. 2016

ATVB

View full text Add to dashboard Cite

A bout 44 million people worldwide are living with dementia, and because of a rapidly aging population this number is predicted to nearly double every 20 years until 2050. 1,2 Consequently, the social and economic burden of dementia will increase enormously, unless preventive or curative measures can be established. Cardiovascular health is increasingly acknowledged as a key determinant in prevention of dementia, including Alzheimer disease (AD).3,4 Yet, the mechanism by which vascular damage leads to cognitive decline remains largely unknown.Although many studies have related cognitive function to static markers of cerebrovascular pathology, such as small vessel disease on magnetic resonance imaging and the retinal vasculature, few provide a functional measure of cerebral vascular disease. Cerebral vasoreactivity (CVR) reflects the ability of the cerebral arterioles and capillaries to dilate in response to increased neuronal metabolic demand, 5 and can be quantified in vivo using transcranial Doppler (TCD) or magnetic resonance imaging. Vasoreactivity is essential for maintenance of continuous cerebral perfusion, and impaired vasoreactivity is associated with (cardiovascular) mortality in the general population 6 and risk of stroke in the presence of flow-limiting carotid artery stenosis. 7 In addition, lower vasoreactivity correlates with higher volumes of cerebral white matter lesions, 8 which are strongly associated with cognitive decline and dementia.9 Several small cross-sectional studies have found CVR to be reduced in patients with dementia or mild cognitive impairment compared with healthy controls, 10-12 but its impact on cognitive decline and the risk of dementia is uncertain.We hypothesized that impaired CVR precedes dementia, and aimed to determine the association of CVR with cognitive decline and the risk of dementia in a population-based study.© 2015 American Heart Association, Inc. Materials and MethodsThis study is embedded within the Rotterdam study, an ongoing population-based cohort study in The Netherlands. TCD investigation with induction of hypercapnia was added to the core protocol for the second follow-up examination, from July 1997 to December 1999. Materials and Methods are available in the online-only Data Supplement. ResultsAmong 2569 eligible participants undergoing TCD with induced hypercapnia, no temporal bone window was present on either side in 632 (24.6%) individuals. Measurements could not be completed in 214 (8.3%) cases because of participants feeling anxious or unwell (n=54), lack of time (n=3), or other undocumented causes (n=157). In addition, in 94 participants we failed to obtain a reliable measurement of CVR despite adequate CO 2 induction, thus leaving a total of 1629 cases for analysis. Baseline characteristics of participants in comparison with nonparticipants are shown in Table 1. CVR was strongly impaired in current smokers and to a lesser extent in participants with a history of hypertension or diabetes mellitus. Conversely, higher systolic and diastoli...

show abstract

“…TCD was first used in neurology in the 1980s and measures cerebral blood flow velocity (CBFV) [2]. TCD has demonstrated utility in the diagnosis of clinical conditions such as acute ischemic stroke [3], intracranial pressure [4], [5], sickle cell disease [6], traumatic brain injury [7], dementia [8], cerebral emboli [9] and many others [10], [11]. K. Jalaleddini, N. Canac, S. Thorpe CBFV beat waveform morphology has not been extensively studied mainly due to the noise level and lack of signal processing techniques developed for TCD signal analysis [4], [12].…”

Section: Introductionmentioning

confidence: 99%

Objective Assessment of Beat Quality in Transcranial Doppler Measurement of Blood Flow Velocity in Cerebral Arteries

Jalaleddini

Canac

Thorpe

et al. 2019

Preprint

View full text Add to dashboard Cite

Objective: Transcranial Doppler (TCD) ultrasonography measures pulsatile cerebral blood flow velocity in the arteries and veins of the head and neck. Similar to other real-time measurement modalities, especially in healthcare, the identification of high quality signals is essential for clinical interpretation. Our goal is to identify poor quality beats and remove them prior to further analysis of the TCD signal.Methods: We selected objective features for this purpose including Euclidean distance between individual and average beat waveform, cross-correlation between individual and average beat waveform, ratio of the high frequency power to the total beat power, beat length, and variance of the diastolic portion of the beat waveform. We developed an iterative outlier detection algorithm to identify and remove the beats that are different from others in a recording. Finally, we tested the algorithm on a dataset consisting of more than 16 hours of TCD data recorded from 48 stroke and 35 in-hospital control subjects.Results: We assessed the performance of the algorithm in estimating clinically important TCD parameters by comparison to those identified from beats hand-annotated by an expert. The results show that there is strong correlation between the two that delineates the algorithm has successfully recovered clinically important features. We obtained significant improvement in estimating the TCD parameters using the algorithm accepted beats compared to using all beats (r>0.78, p<0.01).Significance: Our algorithm provides a valuable tool to the clinicians for automated detection of the reliable portion of the data. Moreover, it can be used as a pre-processing tool to improve the data quality for machine learning algorithms for automated diagnosis of pathologic beat waveform.

show abstract

Cerebrovascular Function in Aging and Dementia: A Systematic Review of Transcranial Doppler Studies

Cited by 69 publications

References 110 publications

Compartmental and Data-Based Modeling of Cerebral Hemodynamics: Nonlinear Analysis

Compartmental and Data-Based Modeling of Cerebral Hemodynamics: Nonlinear Analysis

Cerebral Vasoreactivity, Apolipoprotein E, and the Risk of Dementia

Objective Assessment of Beat Quality in Transcranial Doppler Measurement of Blood Flow Velocity in Cerebral Arteries

Contact Info

Product

Resources

About