Dementia and Stroke Risk Associated with Brain Artery Luminal Diameters

Importance: It is unclear whether brain artery diameters measured on conventional T2-weighted brain MRI images relate to dementia and stroke outcomes across distinct populations. We aimed this study to evaluate the association of T2-weighted brain artery luminal diameters with dementia and stroke in three distinct population‑based studies. Methods: Three longitudinal population-based studies with 8420 adults \u3e40 years old (Northern Manhattan Study [NOMAS] from the United States, and the Rotterdam Study [RS], from the Netherlands, and Three-City, from France) with brain MRI scans obtained between 1999 and 2015. The median follow-up time for clinical events ranged between 7 and 12.5 years. We tested our hypothesis in each cohort separately due to local data‑sharing regulations. The exposure variable was brain carotid and basilar artery luminal diameters measured on MRI axial T2‑weighted scans. Multivariable hazard ratios (HRs) and their 95% confidence intervals (CI) expressed the risk of dementia and stroke (primary outcomes) associated with the lowest (\u3c5th) and highest (\u3e95th) percentiles of the rank‑normalized brain artery diameters compared to a reference group defined as the diameters distributed between the 5th and 95th percentiles. Secondary outcomes included total and vascular mortality, and fatal and nonfatal cardiovascular and coronary end points. Results: Among the three cohorts (mean age ranged from 65 to 73 y, ≥57% women), 335 participants developed dementia and 331 strokes. Compared with the reference group, participants with arterial diameters \u3e95th percentile had a higher risk of dementia (HR range 1.15-4.50) and any stroke (HR range 1.29-2.03). For secondary outcomes, participants with arterial diameters \u3e95th percentile had a consistent higher risk of coronary outcomes, vascular mortality and a composite of any vascular events. The results were less supportive of a higher risk of events among participants with arterial diameters \u3c5th percentile except for vascular mortality. Conclusions: Individuals with dilated brain arteries are at higher risk of dementia and vascular events. Our findings were consistency across distinct populations in spite of using a non-enhanced, conventional T2-weighted MRI sequence. Understanding the underlying physiopathology of the reported associations, particularly with dementia and stroke, might reveal novel vascular contributions to dementia

Assessment and risk stratification of ageing-related target organ damage and adverse health outcomes in the general population

The objectives of this doctoral thesis are to address the contribution of blood pressure to the presence of subclinical target-organ damage and the development of adverse health complications that associate with a poor life course of aging. This thesis focuses on ambulatory blood pressure monitoring to provide the most accurate information about the blood pressure level and variability over a 24-hour period. Moreover, by investigating the role of novel markers, including imaging markers and biomarkers, this thesis also provides possible pathophysiological and biological mechanisms that might explain the association between vascular risk factors and adverse health complications. We envisage that the results of our study will contribute to the refinement of risk stratification of major micro- (ophthalmological, neurological) and macro‑vascular (neurological, cardiovascular) complications associated with poor aging

Effects of missing data imputation methods on univariate blood pressure time series data analysis and forecasting with ARIMA and LSTM

Background Missing observations within the univariate time series are common in real-life and cause analytical problems in the flow of the analysis. Imputation of missing values is an inevitable step in every incomplete univariate time series. Most of the existing studies focus on comparing the distributions of imputed data. There is a gap of knowledge on how different imputation methods for univariate time series affect the forecasting performance of time series models. We evaluated the prediction performance of autoregressive integrated moving average (ARIMA) and long short-term memory (LSTM) network models on imputed time series data using ten different imputation techniques. Methods Missing values were generated under missing completely at random (MCAR) mechanism at 10%, 15%, 25%, and 35% rates of missingness using complete data of 24-h ambulatory diastolic blood pressure readings. The performance of the mean, Kalman filtering, linear, spline, and Stineman interpolations, exponentially weighted moving average (EWMA), simple moving average (SMA), k-nearest neighborhood (KNN), and last-observation-carried-forward (LOCF) imputation techniques on the time series structure and the prediction performance of the LSTM and ARIMA models were compared on imputed and original data. Results All imputation techniques either increased or decreased the data autocorrelation and with this affected the forecasting performance of the ARIMA and LSTM algorithms. The best imputation technique did not guarantee better predictions obtained on the imputed data. The mean imputation, LOCF, KNN, Stineman, and cubic spline interpolations methods performed better for a small rate of missingness. Interpolation with EWMA and Kalman filtering yielded consistent performances across all scenarios of missingness. Disregarding the imputation methods, the LSTM resulted with a slightly better predictive accuracy among the best performing ARIMA and LSTM models; otherwise, the results varied. In our small sample, ARIMA tended to perform better on data with higher autocorrelation. Conclusions We recommend to the researchers that they consider Kalman smoothing techniques, interpolation techniques (linear, spline, and Stineman), moving average techniques (SMA and EWMA) for imputing univariate time series data as they perform well on both data distribution and forecasting with ARIMA and LSTM models. The LSTM slightly outperforms ARIMA models, however, for small samples, ARIMA is simpler and faster to execute

Revitalizing Alzheimer\u27s Community Engagement in the RGV Post-Pandemic: Insights from the First Two Alzheimer\u27s Forums

Background: The Rio Grande Valley (RGV), with a population predominantly composed of Hispanic/Latinos (93%), faces a higher risk of Alzheimer\u27s Disease (AD) compared to other groups. The COVID-19 pandemic has highlighted the lack of education and awareness surrounding AD and related dementias in our community. To address these challenges, we partnered with the Alzheimer\u27s Association to organize the first two Community Forums after the pandemic. Our goal is to raise awareness, provide resources, and support those affected by AD and related conditions in the RGV. Methods: Through a proactive partnership, our objective was to meet the growing demand for education, resources, and support for individuals impacted by Alzheimer\u27s. We hosted two Alzheimer’s Community Forums on May 9th, 2023, at the UTRGV Harlingen Auditorium in Harlingen and May 23rd at UTRGV Salon Cassia in Brownsville. We used the Community Assessment Toolkit as guiding frameworks. These forums served as a dynamic engagement strategy, bringing together healthcare professionals, researchers, and community members to exchange valuable insights and information. With involvement from UTRGV teams, including marketing, we developed impactful marketing resources and invited UTRGV Community Partners to set up informational tables to promote resources for those impacted by dementia. To maximize outreach, we distributed flyers and engaged in conversations with people on the streets. This grassroots approach attracted a significant number of attendees who signed in, allowing us to present crucial information and facilitate discussions. Our Community Partners generously donated door prizes to further incentivize participation and engagement. Results: With the combined forums, we hosted nearly 60 participants, including caregivers, individuals with a family history of AD, community members seeking knowledge, stakeholders, and community health workers. Attendees who were previously unaware of AD and dementia research in the Valley expressed a commitment to prevention and participation in research, including their wish to become volunteers and advocates within their community. Approximately 28 potential participants expressed interest in enrolling in our study. Having individuals willing to actively participate in research is crucial for advancing our understanding of AD and developing potential treatments and preventive measures. The forums have motivated people to become volunteers and advocates within their community, as their involvement can have a positive impact on increasing awareness and driving further research efforts. Conclusions: The Forums provided attendees with increased knowledge and tools for AD awareness and support. Efforts should continue to bridge gender gaps and diversify attendee representation. This report documents the success and impact of these Alzheimer\u27s community forums, aiming to inspire ongoing efforts to raise awareness and improve the quality of life for those affected by AD in the RGV. The strong partnerships forged with Community Partners demonstrated a lasting relationship that we hope will ultimately contribute to positive change in the impact of AD on the RGV and Latino/a community. The forums have clearly had a meaningful impact on the community, fostering engagement, education, and a commitment to AD prevention and research. This outcome reflects the importance of providing platforms for knowledge sharing and community involvement in healthcare initiatives

Using Cartesian Coordinate Systems to Create, Classify, and Retrieve Biomedical Time-Series: Applications to 24-hour Ambulatory Blood Pressure Monitoring

Background: Ambulatory Blood Pressure Measurement (ABPM) allows physicians to monitor blood pressure variability under everyday living conditions and predicts clinical outcomes better than conventional blood-pressure measurement. ABPM can demonstrate mean arterial pressure (MAP) behavior over 24 hours relevant to clinical practice, such as nocturnal hypertension or increased blood pressure variability. We hypothesized that individuals with the same cardiovascular health status would have the same MAP signal (MAPs) waveform. Methods: This study reutilizes a data subset from the IDACO Consortium to create 24-hour MAPs. We assigned all the MAPs to data matrix X, performed principal components analysis (PCA) to X, and calculated the percentage of the total variance explained by each of the 82 principal components (PC). The first three PC explained 85.03%, 9.47%, and 5.50% of the total variance. We used every MAP signal\u27s first three PC scores as their three-dimensional Euclidean Space (x, y, z) coordinates and assigned them to matrix C. Then, we calculated hierarchical clusters of the rows of C with Ward\u27s linkage minimum variance algorithm and a Euclidian metric and encoded this information on the agglomerative hierarchical cluster tree Z. We determined the gap statistic in Z to obtain the optimal number of clusters. We created seven agglomerative clusters from the linkages stored in Z, using Ward’s distance as the criterion for defining the clusters. Finally, we plotted and colored the mapped MAPs by their assigned cluster number at the locations specified by their (x, y, z) coordinates. Results: The MAPs cartesian representations show that MAPs with similar waveforms cluster in the same three-dimensional Euclidean subspace. These patterns identified individuals with dipping and non-dipping blood pressure behavior, which is relevant to clinical management. Conclusions: Mapping a set of physiological signals into a Euclidian space creates a mathematical formalism that provides a statistical framework to classify physiological signals by their waveform. By applying our method to existing electrophysiological and physiological databases, we can cluster any biomedical time-series (blood pressure, ECG, EEG, EMG, patch-clamp, single-unit recordings, etc.) by physiologic or pathological waveform, so further epidemiological and genetic studies can be conducted on the subjects or tissue samples sharing similar patterns

24-Hour Blood Pressure Variability Assessed by Average Real Variability: A Systematic Review and Meta-Analysis

Background-—Although 24-hour blood pressure (BP) variability (BPV) is predictive of cardiovascular outcomes independent of absolute BP levels, it is not regularly assessed in clinical practice. One possible limitation to routine BPV assessment is the lack of standardized methods for accurately estimating 24-hour BPV. We conducted a systematic review to assess the predictive power of reported BPV indexes to address appropriate quantification of 24-hour BPV, including the average real variability (ARV) index. Methods and Results-—Studies chosen for review were those that presented data for 24-hour BPV in adults from meta-analysis, longitudinal or cross-sectional design, and examined BPV in terms of the following issues: (1) methods used to calculate and evaluate ARV; (2) assessment of 24-hour BPV determined using noninvasive ambulatory BP monitoring; (3) multivariate analysis adjusted for covariates, including some measure of BP; (4) association of 24-hour BPV with subclinical organ damage; and (5) the predictive value of 24-hour BPV on target organ damage and rate of cardiovascular events. Of the 19 assessed studies, 17 reported significant associations between high ARV and the presence and progression of subclinical organ damage, as well as the incidence of hard end points, such as cardiovascular events. In all these cases, ARV remained a significant independent predictor (P Conclusions-—Current evidence suggests that ARV index adds significant prognostic information to 24-hour ambulatory BP monitoring and is a useful approach for studying the clinical value of BPV

Exploring Imageability through Architecture to Study Neuroscience: Preliminary Results of a Systemic Review

Background: Neuroscience and architecture are often combined to study the impact of environment, physical spaces, colors, shapes, and buildings on brain activity and health. This is an emerging field with distinct areas examining architecture in relation to neuroscience. Among the numerous elements of architecture, imageability seems to be of particular interest. Imageability refers to the quality of a physical space that evokes strong images in people’s mind, and influence cognitive functions including visual, memory, and spatial recall. It is hypothesized that environments, spaces, and buildings with poor imageability might negatively affect cognition, behavior, and brain health. Diverse studies have been conducted to test such a hypothesis however, there is a lack of compiled evidence that highlights how imageability and neurosciences are connected. Therefore, we conducted this systematic review to explore the current understanding of imageability from an architectural perspective in the study of neuroscience with focused on its implications for cognitive health and well-being. Methods: This review conducted a comprehensive search across four electronic databases: EBSCO, OVID, PubMed, and Web of Science. Our search term included “Imageability” as the main key word combined (AND) with architecture, environment, built environment, neuroarchitecture, aphantasia, urban design, memorability, visual recall, mental visualization, architectural features, façade, wayfinding, familiarity, familiarity, architecture, familiarity, environment, and vividness. Eligibility criteria included peer-reviewed articles in English that focused on the relationship between imageability, health, and architecture. The synthesis of results was conducted following PRISMA\u27s four-phase flow diagram. Results: The initial search showed 5269 articles, which were screened to exclude duplicates (n=1763). Subsequently, we conducted a thorough review of the remaining 3506 articles and we excluded (n=3393) articles that were not related to the research, non-original research (n=24), systematic review (n=5), not enough data (n=3), non-related articles, and for various other reasons (n=13). The selected studies (n=61) highlighted the impact of architecture on cognitive, the role of urban design in mental health, and the application of brain imaging methods to assess the influence of built environments. Imageability involves and contributes to various cognitive processes such as memory, perception, sensation, and language depending on the type of stimuli used. Imagery was shown to activate the visual cortex and showed great activity in the anterior areas of the brain such as the insula, medial frontal cortex, and left dorsal lateral prefrontal cortex. Discussion: This review highlights the potential of integrating neuroscience into architectural design, fostering a multidisciplinary approach to enhance cognitive and brain health. Spaces with high imageability, characterized by distinctive, memorable features, can significantly influence cognitive processes, such as memory and spatial navigation. We found limited manuscripts about imageability in elderly people and this is a gap that warrants attention because of the alarming rates of neurodegenerative diseases such as Alzheimer’s disease-related disorders in elderly populations. The findings suggest that a more profound understanding of imageability within neuroarchitecture can lead to innovative design strategies that support mental and physical well-being

Impacts of imageability of architecture on brain health: A systematic literature review

Imageability is a component of urban design and planning that has been recognized for its potential to enhance people’s perceptual and emotional engagement with their environment. Nevertheless, evidence supporting specific strategies and its impacts on brain health is still unclear. This systematic review aimed to characterize and summarize the evidence on the importance of imageability of architecture for brain cognitive and psychological health. This systematic review was conducted following the PRISMA guidelines. Our keywords included imageability and architecture, environment, built environment, neuroarchitecture, aphantasia, urban design, memorability, visual recall, mental visualization, architectural features, façade, wayfinding, familiarity, vividness, cognition, expectations, green walls, biophilia, aesthetics, emotions, embodied cognition and embodiment. We searched electronic databases for studies showing the relationship among imageability, architecture, and neuroscience. From the 5,270 identified articles, we included 56 original peer-reviewed articles. The findings suggest that environments with high imageability are correlated with better cognitive and psychological health, high emotional engagement, and enhanced social connectivity. In conclusion, studies have also highlighted that high-imageability environments enhance livability, promote wayfinding, and support physical activity. However, some gaps were identified, including the need for standardized methods to assess imageability and its impact on brain health by examining brain structures and functions with imaging studies. Imageability seems to play an important role in creating environments that promote cognitive and psychological health, physical activity and foster a sense of community belonging. Future research should focus on developing objective, replicable methods for evaluating imageability and exploring the neural paths that underlie its effects

Retinal Microvasculature in Relation to Central Hemodynamics in a Flemish Population

Arterial stiffness and wave reflection predict cardiovascular mortality and morbidity and are associated with renal microvascular disease. We hypothesized that the retinal microvascular traits might be associated with central hemodynamic properties. In 735 randomly recruited Flemish (mean age, 50.3 years; 47.1% women), we derived central pulse pressure and carotid-femoral pulse wave velocity by applanation tonometry and calculated forward (Pf) and backward (Pb) pulse waves, using an automated pressure-based wave separation algorithm. We measured central retinal arteriolar (CRAE) and venular equivalent and their ratio, using IVAN software (Vasculomatic ala Nicola, version 1.1). Mean values for pulse wave velocity (n=554), Pf and Pb were 7.50 m/s, 32.0 mm Hg, and 21.5 mm Hg, respectively. In multivariable-adjusted analyses, CRAE was 4.62 µm and 1.26 µm smaller (P≤0.034) for a 1-SD increment in central mean arterial pressure (+11.3 mm Hg) and central pulse pressure (+15.2 mm Hg); a 1-SD increment in the augmentation ratio (+7.0%), aortic pulse wave velocity (+1.66 m/s), Pf (+10.0 mm Hg), and Pb (+8.5 mm Hg), was associated with smaller CRAE; the association sizes were -1.91 µm, -1.59 µm, -1.45 µm, and -2.38 µm (P≤0.014), respectively. Associations of arteriole-to-venule diameter ratio with the central hemodynamic traits mirrored those of CRAE. None of the multivariable-adjusted associations of central retinal venular diameter with the central hemodynamic traits reached significance with the exception of central diastolic blood pressure (-1.62 µm; P=0.030). In conclusion, in the general population, higher central pulse pressure, pulse wave velocity, Pf, and Pb were associated with smaller CRAE

Identification of Retinal Microvasculature Associated with Alzheimer’s Disease-Related Disorders Using Optical Tomography Coherence Angiography: A Systematic Review

Introduction: Alzheimer’s dementia (AD) is the most common type of form of dementia in older adults. Detection and diagnosis are based on invasive and expensive procedures including PET scanning and lumbar puncture cerebrospinal fluid analysis. Optical Tomography Coherence (OCT) angiography may be an alternative solution for early, cost-effective non-invasive detection of AD. We aimed to conduct a systematic review to summarize the current evidence describing the association between OCT angiography and AD using PubMed as data source. Methods: Pubmed was used to compile resources for a systematic review. Keywords used include “Alzheimer’s disease”, “preclinical Alzheimer’s disease”, “OCT”, “OCTA”, “neurovascular degeneration”, “retina”, “vessel density”, “foveal avascular zone”, “Optical imaging”, “dementia”, “optic nerve”, “retinal biomarkers”, and “retinal imaging.” Only original research studies were included in this systematic review. Results: Macular volume and choroidal thickness were both decreased. OCTA demonstrated reduced vascular density in the macula, superficial, and deep vascular plexus in AD. There was an inverse relationship between vessel density and associated AD risk. There was also foveal avascular zone enlargement. Limitations of these studies are often secondary to the small sample sizes. Furthermore, there needs to be repeat testing to validate that OCTA imaging may perform better than the gold-standard neuropathological examination. Another challenge would be the lack of specificity for the detection of AD, because microvascular retinal changes are not exclusive to AD and may occur in other neurodegenerative disorders Conclusions: Assessment of the retinal microcirculation might represent a unique and novel opportunity to investigate AD. Imaging modalities have shown neurovascular changes, amyloid beta and tau deposition, neurodegenerative changes, and inflammation, all of which may potentially be used as new biomarkers. Imaging may also be used in the future as an objective measure to track disease progression. Future studies are needed for deeper understanding of the pathophysiology relationship between AD and the retina. Furthermore, studies need to be expanded to include more participants with more diverse demographics. This new information could lead to innovation in optical imaging technology and a standardization of retinal imaging used in the diagnosis and management of AD