The role of exercise in mitigating subcortical ischemic vascular cognitive impairment

Comparative effect of Tai Chi and aerobic exercise on cognitive function in advanced lung cancer survivors with perceived cognitive impairment: a three-arm randomized controlled trial with mediation analysis

PURPOSE

Cancer-related cognitive impairment is prevalent in metastatic lung cancer survivors. This study aimed to compare the effectiveness of aerobic exercise and Tai Chi on perceived cognitive function and the mediating role of psychoneurological symptoms with perceived cognitive impairment.

METHODS

In a subgroup of a parent randomized clinical trial, participants who reported cognitive impairment underwent a 16-week aerobic exercise (n = 49), Tai Chi (n = 48), and control (n = 54) groups. Measures included perceived cognitive function and psychoneurological symptoms (sleep disturbance, fatigue, anxiety, and depression) assessed at baseline (T0), 16-week (T1), and 1 year (T2).

RESULTS

Participants in Tai Chi showed significant improvements compared to aerobic exercise and control groups in perceived cognitive function at T1 (AE: between-group difference, 6.52; P < 0.001; CG: 8.34; P < 0.001) and T2 (AE: between-group difference, 3.55; P = 0.05; CG: 5.94; P < 0.001). Sleep disturbance, fatigue, anxiety, and depression at month 12 explained 24%, 31%, 32%, and 24% of the effect of the intervention on cognitive function at month 12, respectively. Only anxiety at month 4 explained 23% of the intervention effect at month 12.

CONCLUSIONS

Tai Chi demonstrated beneficial effects on cognitive function in advanced lung cancer survivors with perceived cognitive impairment. Improvement in cognitive function was mediated by reducing sleep disturbance, fatigue, anxiety, and depression, highlighting the importance of addressing these symptoms in future interventions to improve cognitive function, with anxiety playing a significant role at an earlier stage.

IMPLICATIONS FOR CANCER SURVIVORS

Tai Chi is a potentially safe complementary therapeutic option for managing cognitive impairment in this vulnerable population.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04119778; retrospectively registered on 8 October 2019.

Resistance Training Maintains White Matter and Physical Function in Older Women with Cerebral Small Vessel Disease: An Exploratory Analysis of a Randomized Controlled Trial

Background

As the aging population grows, there is an increasing need to develop accessible interventions against risk factors for cognitive impairment and dementia, such as cerebral small vessel disease (CSVD). The progression of white matter hyperintensities (WMHs), a key hallmark of CSVD, can be slowed by resistance training (RT). We hypothesize RT preserves white matter integrity and that this preservation is associated with improved cognitive and physical function.

Objective

To determine if RT preserves regional white matter integrity and if any changes are associated with cognitive and physical outcomes.

Methods

Using magnetic resonance imaging data from a 12-month randomized controlled trial, we compared the effects of a twice-weekly 60-minute RT intervention versus active control on T1-weighted over T2-weighted ratio (T1w/T2w; a non-invasive proxy measure of white matter integrity) in a subset of study participants (N = 21 females, mean age = 69.7 years). We also examined the association between changes in T1w/T2w with two key outcomes of the parent study: (1) selective attention and conflict resolution, and (2) peak muscle power.

Results

Compared with an active control group, RT increased T1w/T2w in the external capsule (p = 0.024) and posterior thalamic radiations (p = 0.013) to a greater degree. Increased T1w/T2w in the external capsule was associated with an increase in peak muscle power (p = 0.043) in the RT group.

Conclusion

By maintaining white matter integrity, RT may be a promising intervention to counteract the pathological changes that accompany CSVD, while improving functional outcomes such as muscle power.

Impact of Diet and Exercise Interventions on Cognition and Brain Health in Older Adults: A Narrative Review

The ability to preserve cognitive function and protect brain structure from the effects of the aging process and neurodegenerative disease is the goal of non-pharmacologic, lifestyle interventions focused on brain health. This review examines, in turn, current diet and exercise intervention trends and the collective progress made toward understanding their impact on cognition and brain health. The diets covered in this review include the Mediterranean diet (MeDi), Dietary Approaches to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), ketogenic diet, intermittent fasting, and weight loss management. The exercise approaches covered in this review include endurance, resistance, combined exercise programs, yoga, tai chi, and high-intensity interval training. Although valuable evidence is building concerning how diet and exercise influence cognitive performance and brain structure, many of the open questions in the field are concerned with why we see these effects. Therefore, more strategically designed intervention studies are needed to reveal the likely multiple mechanisms of action in humans.

Multimodality neuroimaging in vascular mild cognitive impairment: A narrative review of current evidence

The vascular mild cognitive impairment (VaMCI) is generally accepted as the premonition stage of vascular dementia (VaD). However, most studies are focused mainly on VaD as a diagnosis in patients, thus neglecting the VaMCI stage. VaMCI stage, though, is easily diagnosed by vascular injuries and represents a high-risk period for the future decline of patients’ cognitive functions. The existing studies in China and abroad have found that magnetic resonance imaging technology can provide imaging markers related to the occurrence and development of VaMCI, which is an important tool for detecting the changes in microstructure and function of VaMCI patients. Nevertheless, most of the existing studies evaluate the information of a single modal image. Due to the different imaging principles, the data provided by a single modal image are limited. In contrast, multi-modal magnetic resonance imaging research can provide multiple comprehensive data such as tissue anatomy and function. Here, a narrative review of published articles on multimodality neuroimaging in VaMCI diagnosis was conducted，and the utilization of certain neuroimaging bio-markers in clinical applications was narrated. These markers include evaluation of vascular dysfunction before tissue damages and quantification of the extent of network connectivity disruption. We further provide recommendations for early detection, progress, prompt treatment response of VaMCI, as well as optimization of the personalized treatment plan.

A Nationwide Multi-Center Questionnaire Survey on the Real-World State and Clinical Management of Poststroke Dementia in Japan

Background:

Poststroke dementia (PSD) is a serious problem for stroke survivors. However, there is still limited data on the real-world state and clinical management of PSD worldwide, and several countries already have a super-aged society.

Objective:

We conducted a nationwide questionnaire survey to examine the real-world state and management of PSD in Japan.

Methods:

A survey was conducted in the top 500 Japanese hospitals regarding the number of stroke patients treated between July 2018 and August 2019. Thirteen questions regarding PSD were mailed to doctors responsible for stroke management.

Results:

Responses were obtained from 251 hospitals (50.2%). The chief doctors responsible for stroke management answered the questionnaires. The median numbers of patients admitted annually with stroke in the departments of neurology and neurosurgery in the hospitals were 281.0 (interquartile range [IQR], 231.8–385.3) and 253.5 (IQR, 210.0–335.3), respectively, and most hospitals were acute care hospitals. Executive dysfunction was the most common cognitive dysfunction (10.9%), followed by amnesia (9.5%) and apathy (4.1%). Surprisingly, many stroke survivors lived alone at home (23.7%). Montreal Cognitive Assessment was significantly uncommon compared to Mini-Mental State Examination (p < 0.01). Furthermore, objective evaluation tests for behavioral and psychological symptoms of dementia were not often performed. Cognitive rehabilitation treatments were performed more often and earlier than drug treatments. The first drug of choice for PSD was predominantly donepezil (79.1%), followed by galantamine (6.1%), cilostazol (4.9%), memantine (2.5%), and rivastigmine (1.8%).

Conclusion:

Our study provides real-world evidence for the state of clinical practice related to PSD in Japan.

Cardiovascular risk moderates the effect of aerobic exercise on executive functions in older adults with subcortical ischemic vascular cognitive impairment

Aerobic training (AT) can promote cognitive function in adults with Subcortical Ischemic Vascular Cognitive Impairment (SIVCI) by modifying cardiovascular risk factors. However, pre-existing cardiovascular health may attenuate the benefits of AT on cognitive outcomes in SIVCI. We examined whether baseline cardiovascular risk moderates the effect of a 6-month progressive AT program on executive functions with a secondary analysis of a randomized controlled trial in 71 adults, who were randomized to either: (1) 3×/week progressive AT; or (2) education program (CON). Three executive processes were measured: (1) response inhibition by Stroop Test; (2) working memory by digits backward test; and (3) set shifting by the Trail Making Test. Baseline cardiovascular risk was calculated using the Framingham cardiovascular disease (CVD) Risk Score (FCRS), and participants were classified as either low risk (< 20% FCRS score; LCVR) or high risk (≥ 20% FCRS score; HCVR). A complete case analysis (n = 58) was conducted using an analysis of covariance (ANCOVA) to evaluate between-group differences in the three executive processes. A significant interaction was found between cardiovascular risk group and intervention group (AT or CON) for the digit span backward and the Trail Making Test. AT improved performance compared with CON in those with LCVR, while in those with HCVR, AT did not improve performance compared with CON. Baseline cardiovascular risk significantly moderates the efficacy of AT on cognition. Our findings highlight the importance of intervening early in the disease course of SIVCI, when cardiovascular risk may be lower, to reap maximum benefits of aerobic exercise.

Mind the gaps: functional networks disrupted by white matter hyperintensities are associated with greater falls risk

White matter hyperintensities (WMH) are associated with greater falls risk and slow gait speed. Whether these deficits are caused by the disruption of large-scale functional networks remains inconclusive. Further, physical activity moderates the association between WMHs and falls, but whether this extends to the disruption of functional networks remains unknown. One hundred and sixty-four adults (>55 years old) were included in this study. Using lesion network mapping, we identified significant correlations between the percentage of WMH-related disruption of the dorsal attention network and Physiological Profile Assessment (PPA) score (r = 0.24, p < 0.01); and between disruption of both the sensorimotor (r = 0.23, p < 0.01) and ventral attention networks (r = 0.21, p = 0.01) with foam sway. There were no significant associations with floor sway or gait speed. Physical activity moderated the association between the dorsal attention network and PPA score (p = 0.045). Thus, future research should investigate whether physical activity should be recommended in the clinical management of older adults with cerebral small vessel disease.

Lactate as Potential Mediators for Exercise-Induced Positive Effects on Neuroplasticity and Cerebrovascular Plasticity

The accumulated evidence from animal and human studies supports that exercise is beneficial to physical health. Exercise can upregulate various neurotrophic factors, activate neuroplasticity, and play a positive role in improving and enhancing cerebrovascular function. Due to its economy, convenience, and ability to prevent or ameliorate various aging-related diseases, exercise, a healthy lifestyle, is increasingly popularized by people. However, the mechanism by which exercise performs this function and how it is transmitted from muscles to the brain remains incompletely understood. Here, we review the beneficial effects of exercise with different intensities on the brain with a focus on the positive effects of lactate on neuroplasticity and cerebrovascular plasticity. Based on these recent studies, we propose that lactate, a waste previously misunderstood as a by-product of glycolysis in the past, may be a key signal molecule that regulates the beneficial adaptation of the brain caused by exercise. Importantly, we speculate that a central protective mechanism may underlie the cognitive benefits induced by exercise.

Sweat the Fall Stuff: Physical Activity Moderates the Association of White Matter Hyperintensities With Falls Risk in Older Adults

Background: Falls in older adults are a major public health problem. White matter hyperintensities (WMHs) are highly prevalent in older adults and are a risk factor for falls. In the absence of a cure for WMHs, identifying potential strategies to counteract the risk of WMHs on falls are of great importance. Physical activity (PA) is a promising countermeasure to reduce both WMHs and falls risk. However, no study has yet investigated whether PA attenuates the association of WMHs with falls risk. We hypothesized that PA moderates the association between WMHs and falls risk.

Methods: Seventy-six community-dwelling older adults aged 70–80 years old were included in this cross-sectional study. We indexed PA using the Physical Activity Score for the Elderly (PASE) Questionnaire. Falls risk was assessed using the Physiological Profile Assessment (PPA), and WMH volume (mm³) was determined by an experienced radiologist on T2-weighted and PD-weighted MRI scans. We first examined the independent associations of WMH volume and PASE score with PPA. Subsequently, we examined whether PASE moderated the relationship between WMH volume and PPA. We plotted simple slopes to interpret the interaction effects. Age, sex, and Montreal Cognitive Assessment (MoCA) score were included as covariates in all models.

Results: Participants had a mean age of 74 years (SD = 3 years) and 54 (74%) were female. Forty-nine participants (66%) had a Fazekas score of 1, 19 (26%) had a score of 2, and 6 (8%) a score of 3. Both PASE (β = −0.26 ± 0.11; p = 0.022) and WMH volume (β = 0.23 ± 0.11; p = 0.043) were each independently associated with PPA score. The interaction model indicated that PASE score moderated the association between WMH volume and PPA (β = −0.27 ± 0.12; p = 0.030), whereby higher PASE score attenuated the association between WMHs and falls risk.

Conclusion: PA is an important moderator of falls risk. Importantly, older adults with WMH can reduce their risk of falls by increasing their PA.

Painting by lesions: White matter hyperintensities disrupt functional networks and global cognition

White matter hyperintensities (WMH) are a prominent feature of cerebral small vessel disease and are associated with cognitive impairment. These deficits in cognition may be caused by the disruption of large-scale functional networks due to the presence of WMHs. However, knowledge regarding the relevance of these lesions on functional networks remains inconclusive. These inconsistencies may derive from issues with interpreting functional imaging data from clinical populations. Lesion network mapping is a technique that allows the overlaying of lesions from a patient population to the functional connectivity of a human connectome derived from healthy adults. This allows researchers to identify functional networks that would be disrupted in a healthy population should the WMHs seen in cerebral small vessel disease be present. We hypothesized that the extent to which these functional networks are disrupted by WMHs is associated with cognitive performance in older adults with cerebral small vessel disease. This cross-sectional study combined baseline data from four studies to create a total sample of 164 older adults (aged ≥55) from metropolitan Vancouver with cerebral small vessel disease. Using lesion network mapping, we assessed the percentage overlap between voxels functionally connected with both the WMHs (lesion network) and five common functional networks: (1) visual; (2) dorsal attention; (3) ventral attention; (4) sensorimotor; and (5) frontoparietal. Cognition was assessed using: (1) Montreal Cognitive Assessment (MoCA); (2) Stroop Colour Word Test (3-2); (3) Trail Making Tests (Part B-A); and (4) Digit Symbol Substitution Test. A One-Way ANOVA and Tukey post-hoc tests were performed to identify the functional networks with greatest percentage overlap with the lesion network. Partial correlations controlling for age were used to analyse whether the extent of the overlap between the lesion and functional networks was associated with poorer cognition. The visual, ventral attention, and frontoparietal networks had significantly greater overlap with the lesion network. After controlling for multiple comparisons, level of lesion network overlap with both the sensorimotor network (p<.001) and ventral attention network (p <. 001) was significantly correlated with MoCA score. Thus, the greater the disruption to the sensorimotor and ventral attention networks, the poorer the global cognition. Our results reveal that the visual, ventral attention, and frontoparietal networks are most vulnerable to disruptions stemming from WMHs. Additionally, we identified that disruption to the sensorimotor and ventral attention networks, as a result of WMHs, may underlie deficits in global cognition in older adults with cerebral small vessel disease.

Reshaping the path of vascular cognitive impairment with resistance training: a study protocol for a randomized controlled trial

Background

Subcortical ischemic vascular cognitive impairment (SIVCI) is the most common form of vascular cognitive impairment. Importantly, SIVCI is considered the most treatable form of cognitive impairment in older adults, due to its modifiable risk factors such as hypertension, diabetes mellitus, and hypercholesterolemia. Exercise training is a promising intervention to delay the progression of SIVCI, as it actively targets these cardiometabolic risk factors. Despite the demonstrated benefits of resistance training on cognitive function and emerging evidence suggesting resistance training may reduce the progression of white matter hyperintensities (WMHs), research on SIVCI has predominantly focused on the use of aerobic exercise. Thus, the primary aim of this proof-of-concept randomized controlled trial is to investigate the efficacy of a 12-month, twice-weekly progressive resistance training program on cognitive function and WMH progression in adults with SIVCI. We will also assess the efficiency of the intervention.

Methods

Eighty-eight community-dwelling adults, aged > 55 years, with SIVCI from metropolitan Vancouver will be recruited to participate in this study. SIVCI will be determined by the presence of cognitive impairment (Montreal Cognitive Assessment < 26) and cerebral small vessel disease using computed tomography or magnetic resonance imaging. Participants will be randomly allocated to a twice-weekly exercise program of (1) progressive resistance training or (2) balance and tone training (i.e., active control). The primary outcomes are cognitive function measured by the Alzheimer’s Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-13 with additional cognitive tests) and WMH progression.

Discussion

The burden of SIVCI is immense, and to our knowledge, this will be the first study to quantify the effect of progressive resistance training on cognitive function and WMH progression among adults with SIVCI. Slowing the rate of cognitive decline and WMH progression could preserve functional independence and quality of life. This could lead to reduced health care costs and avoidance of early institutional care.

Trial registration

ClinicalTrials.gov NCT02669394. Registered on February 1, 2016

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05156-1.

Double-task exercise programmes to strengthen cognitive and vascular health in older adults at risk of cognitive decline: protocol for a randomised clinical trial

INTRODUCTION

Cognitive and physical declines are frequent causes of disability among older adults (OAs) in Mexico that imposes significant burden on the health system and OAs' families. Programmes to prevent or delay OAs' cognitive and physical decline are scarce.

METHODS AND ANALYSIS

A double-blind randomised clinical trial will be conducted. The study will aim to evaluate two 24-week double-task (aerobic and cognitive) square-stepping exercise programmes for OAs at risk of cognitive decline-one programme with and another without caregiver participation-and to compare these with an aerobic-balance-stretching exercise programme (control group). 300 OAs (100 per group) affiliated with the Mexican Institute of Social Security (IMSS) between 60 and 65 years of age with self-reported cognitive concerns will participate. They will be stratified by education level and randomly allocated to the groups. The intervention will last 24 weeks, and the effect of each programme will be evaluated 12, 24 and 52 weeks after the intervention. Participants' demographic and clinical characteristics will be collected at baseline. The outcomes will include: (1) general cognitive function; (2) specific cognitive functions; (3) dual-task gait; (4) blood pressure; (5) carotid intima-media thickness; (6) OAs' health-related quality of life; and (7) caregiver burden. The effects of the interventions on each outcome variable will be examined using a repeated-measures analysis of variance (ANOVA), with study groups as the between-subjects variable and time as the within-subject variable.

ETHICS AND DISSEMINATION

The study was approved by the IMSS Ethics and Research Committees (registration number: 2018-785-095). All participants will sign a consent form prior to their participation. The study results will be disseminated to the IMSS authorities, healthcare providers and the research community.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT04068376).

Cortical Alterations Are Associated with Depression in Subcortical Vascular Mild Cognitive Impairment Revealed by Surface-Based Morphometry

BACKGROUND

Late-life depression often coexists with vascular cognitive impairment and affects the quality of life for elders. However, little is known about cortical morphometric interactions between subcortical vascular mild cognitive impairment (svMCI) and concomitant mild depressive symptoms at the early stage.

OBJECTIVE

We aimed to investigate cortical alterations of svMCI with and without depressive symptoms and determine whether these parameters are associated with depression symptoms and/or cognitive impairments.

METHODS

Surface based morphometry was performed on 18 svMCI patients with depressive symptoms (svMCI + D), 16 svMCI patients without depressive symptoms (svMCI-D), and 23 normal controls (NC).

RESULTS

Compared to NC, both svMCI + D and svMCI-D patients exhibited significantly decreased surface area (SA) in many cortical areas. Interestingly, svMCI + D patients showed significantly increased rather than decreased SA in right lateral occipital gyrus (LOG.R), and a consistent trend of increased SA in these areas compared to svMCI-D. In addition, the svMCI + D showed increased gray matter volume of left pericalcarine (periCAL.L) than svMCI-D, whereas svMCI-D showed decreased gray matter volume of periCAL.L than NC. Further correlation analyses revealed that the SA of left superior temporal gyrus (STG.L) and right lateral orbital part of frontal gyrus (lorbFG.R) were significantly correlated with Hamilton depression rating scale of svMCI + D.

CONCLUSION

In conclusion, these results extend our insight into svMCI and add weight to reevaluation of concomitant early stage depressive symptoms. Moreover, we suggest that LOG.R∖periCAL.L∖STG.L∖lorbFG.R might serve as sensitive and trait-dependent biomarkers to detect concomitant depressive symptoms in svMCI patients.

Exercise May Affect Metabolism in Cancer-Related Cognitive Impairment

Cancer-related cognitive impairment (CRCI) is a significant comorbidity for cancer patients and survivors. Physical activity (PA) has been found to be a strong gene modulator that can induce structural and functional changes in the brain. PA and exercise reduce the risk of cancer development and progression and has been shown to help in overcoming post-treatment syndromes. Exercise plays a role in controlling cancer progression through direct effects on cancer metabolism. In this review, we highlight several priorities for improving studies on CRCI in patients and its underlying potential metabolic mechanisms.

Arterial Stiffness and Cognition Among Adults: A Systematic Review and Meta-Analysis of Observational and Longitudinal Studies

Background

To estimate the strength of the cross‐sectional and longitudinal association between arterial stiffness, measured by pulse‐wave velocity, and cognitive function, distinguishing between global cognition, executive functions, and memory and to examine the influence of demographic, clinical, and assessment characteristics on this relationship.

Methods and Results

Systematic review of MEDLINE (via PubMed), Scopus, and WOS databases from their inception to March 2019, to identify cross‐sectional and longitudinal studies on the association between pulse‐wave velocity and cognitive domains (ie, global cognition, executive functions, and memory) among adult population. A total of 29 cross‐sectional and 9 longitudinal studies support the negative relationship between arterial stiffness and cognitive function, including global cognition, executive function, and memory. Demographic, clinical, and assessment characteristics did not substantially modify the strength of this association.

Conclusions

Evidence reveals a negative association between arterial stiffness, measured using pulse‐wave velocity, and cognition, specifically executive function, memory, and global cognition. This association seems to be independent of demographic, clinical, and assessment characteristics. These results accumulate evidence supporting that pulse‐wave velocity assessment could be a useful tool to identify individuals at high risk of cognitive decline or early stages of cognitive decline, to implement interventions aimed at slowing the progression to dementia.

The Effect of Exercise on Cancer-Related Cognitive Impairment and Applications for Physical Therapy: Systematic Review of Randomized Controlled Trials

BACKGROUND

Cancer-related cognitive impairment (CRCI), often called "chemo-brain" or "chemo-fog," is a common side effect among adults with cancer, which can persist well after treatment completion. Accumulating evidence demonstrates exercise can improve cognitive function in healthy older adults and adults with cognitive impairments, suggesting exercise may play a role in managing CRCI.

PURPOSE

The purpose was to perform a systematic review of randomized controlled trials (RCTs) to understand the effect of exercise on CRCI.

DATA SOURCES

Relevant literature was retrieved from CINAHL, Medline (Ovid), and EMBASE.

STUDY SELECTION

Eligible articles were RCTs that prescribed aerobic, resistance, combined aerobic/resistance, or mind-body (eg, yoga or Qigong) exercise during or following cancer treatment and included cognitive function outcome measures.

DATA EXTRACTION

Descriptive information and Cohen d effect sizes were directly extracted or calculated for included trials.

DATA SYNTHESIS

Twenty-nine trials were included in the final analysis. A statistically significant effect of exercise on self-reported cognitive function, both during and postadjuvant treatment, was reported in 12 trials (41%) (Cohen d range: 0.24-1.14), most commonly using the EORTC QLQ-C30. Ten trials (34%) performed neuropsychological testing to evaluate cognitive function; however, only 3 trials in women with breast cancer reported a significant effect of exercise (Cohen d range: 0.41-1.47).

LIMITATIONS

Few RCTs to date have evaluated the effect of exercise on CRCI as a primary outcome. Twenty-six trials (90%) in this review evaluated CRCI as secondary analyses.

CONCLUSIONS

Evidence supporting exercise as a strategy to address CRCI is limited. Future research evaluating CRCI as a primary outcome, including self-reported and objective measures, is needed to confirm the possible role of exercise in preventing and managing cognitive impairments in adults with cancer.

Physical Activity and Cerebral Small Vein Integrity in Older Adults

Identifying promoters of cerebral small vein integrity is important to counter vascular contributions to cognitive impairment and dementia.

PURPOSE

In this preliminary investigation, the effects of a randomized 24-month physical activity (PA) intervention on changes in cerebral small vein integrity were compared to those of a health education (HE) control.

METHODS

Cerebral small vein integrity was measured in 24 older adults (n = 8, PA; n = 16, HE) using ultra-high field MRI before and at the end of the 24-month intervention. Deep medullary veins were defined as straight or tortuous; percent change in straight length, tortuous length, and tortuosity ratio were computed. Microbleed count and white matter hyperintensities were also rated.

RESULTS

Accelerometry-based values of PA increased by 17.2% in the PA group but declined by 28.0% in the HE group. The PA group, but not the HE group, had a significant increase in straight vein length from baseline to 24-month follow-up (P = 0.02 and P = 0.21, respectively); the between-group difference in percent change in straight length was significant (increase: median, 93.6%; interquartile range, 112.9 for PA; median, 28.4%; interquartile range, 90.6 for HE; P = 0.07). Between group differences in other markers were nonsignificant.

CONCLUSIONS

Increasing PA in late-life may promote cerebral small vein integrity. This should be confirmed in larger studies.

Cerebral Small Vessel Disease (CSVD) - Lessons From the Animal Models

Cerebral small vessel disease (CSVD) refers to a spectrum of clinical and imaging findings resulting from pathological processes of various etiologies affecting cerebral arterioles, perforating arteries, capillaries, and venules. Unlike large vessels, it is a challenge to visualize small vessels in vivo, hence the difficulty to directly monitor the natural progression of the disease. CSVD might progress for many years during the early stage of the disease as it remains asymptomatic. Prevalent among elderly individuals, CSVD has been alarmingly reported as an important precursor of full-blown stroke and vascular dementia. Growing evidence has also shown a significant association between CSVD's radiological manifestation with dementia and Alzheimer's disease (AD) pathology. Although it remains contentious as to whether CSVD is a cause or sequelae of AD, it is not far-fetched to posit that effective therapeutic measures of CSVD would mitigate the overall burden of dementia. Nevertheless, the unifying theory on the pathomechanism of the disease remains elusive, hence the lack of effective therapeutic approaches. Thus, this chapter consolidates the contemporary insights from numerous experimental animal models of CSVD, to date: from the available experimental animal models of CSVD and its translational research value; the pathomechanical aspects of the disease; relevant aspects on systems biology; opportunities for early disease biomarkers; and finally, converging approaches for future therapeutic directions of CSVD.

The many faces of vascular cognitive impairment

This Preface introduces the articles of the special issue on "Vascular Dementia" in which several recognized experts provide an overview of this research field. The brain is a highly vascularized organ and consequently, vascular dysfunction and related pathways affect cognitive performance and memory. Vascular dementia or vascular cognitive impairment is the second most common type of dementia after Alzheimer's disease, and both disorders often occur in parallel. With this special issue, we hope to provide insight and a stimulating discussion for the future development of this research field. This article is part of the Special Issue "Vascular Dementia".