Vascular cognitive impairment: Advances and trends

A Comparison of Two Multi-Tasking Approaches to Cognitive Training in Cardiac Surgery Patients

BACKGROUND

The multi-tasking approach may be promising for cognitive rehabilitation in cardiac surgery patients due to a significant effect on attentional and executive functions. This study aimed to compare the neuropsychological changes in patients who have undergone two variants of multi-tasking training and a control group in the early postoperative period of coronary artery bypass grafting (CABG).

METHODS

One hundred and ten CABG patients were divided into three groups: cognitive training (CT) I (a postural balance task with mental arithmetic, verbal fluency, and divergent tasks) (n = 30), CT II (a simple visual-motor reaction with mental arithmetic, verbal fluency, and divergent tasks) (n = 40), and control (n = 40).

RESULTS

Two or more cognitive indicators improved in 93.3% of CT I patients, in 72.5% of CT II patients, and in 62.5% of control patients; CT I patients differed from CT II and control (p = 0.04 and p = 0.008, respectively). The improving short-term memory and attention was found more frequently in the CT I group as compared to control (56.7% vs. 15%; p = 0.0005). The cognitive improvement of all domains (psychomotor and executive functions, attention, and short-term memory) was also revealed in CT I patients more frequently than CT II (46.7% vs. 20%; p = 0.02) and control (46.7% vs. 5%; p = 0.0005).

CONCLUSIONS

The CT I multi-tasking training was more effective at improving the cognitive performance in cardiac surgery patients as compared to CT II training and standard post-surgery management. The findings of this study will be helpful for future studies involving multi-tasking training.

Alzheimer's and vascular disease classification using regional texture biomarkers in FLAIR MRI

Interactions between subcortical vascular disease and dementia due to Alzheimer's disease (AD) are unclear, and clinical overlap between the diseases makes diagnosis challenging. Existing studies have shown regional microstructural changes specific to each disease, and that textures in fluid-attenuated inversion recovery (FLAIR) MRI images may characterize abnormalities in tissue microstructure. This work aims to investigate regional FLAIR biomarkers that can differentiate dementia cohorts with and without subcortical vascular disease. FLAIR and diffusion MRI (dMRI) volumes were obtained in 65 mild cognitive impairment (MCI), 21 AD, 44 subcortical vascular MCI (scVMCI), 22 Mixed etiology, and 48 healthy elderly patients. FLAIR texture and intensity biomarkers were extracted from the normal appearing brain matter (NABM), WML penumbra, blood supply territory (BST), and white matter tract regions of each patient. All FLAIR biomarkers were correlated to dMRI metrics in each region and global WML load, and biomarker means between groups were compared using ANOVA. Binary classifications were performed using Random Forest classifiers to investigate the predictive nature of the regional biomarkers, and SHAP feature analysis was performed to further investigate optimal regions of interest for differentiating disease groups. The regional FLAIR biomarkers were strongly correlated to MD, while all biomarker regions but white matter tracts were strongly correlated to WML burden. Classification between Mixed disease and healthy, AD, and scVMCI patients yielded accuracies of 97%, 81%, and 72% respectively using WM tract biomarkers. Classification between scVMCI and healthy, MCI, and AD patients yielded accuracies of 89%, 84%, and 79% respectively using penumbra biomarkers. Only the classification between AD and healthy patients had optimal results using NABM biomarkers. This work presents novel regional FLAIR biomarkers that may quantify white matter degeneration related to subcortical vascular disease, and which indicate that investigating degeneration in specific regions may be more important than assessing global WML burden in vascular disease groups.

Machine-learning-based analysis of the sensitivity and specificity on lipid-lowering effect of one-month-administered statins

Few predictive studies have been reported on the efficacy of atorvastatin in reducing lipoprotein cholesterol to be qualified after 1-month course of treatment in different individuals. A total of 14,180 community-based residents aged ≥ 65 received health checkup, 1013 of whom had low-density lipoprotein (LDL) higher than 2.6mmol/L so that they were put on 1-month course of treatment with atorvastatin. At its completion, lipoprotein cholesterol was measured again. With < 2.6 mmol/L considered as the treatment standard, 411 individuals were judged as the qualified group, and 602, and as the unqualified group. The basic sociodemographic features covered 57 items. The data were randomly divided into train sets and test ones. The recursive random-forest algorithm was applied to predicting the patients response to atorvastatin, the recursive feature elimination method, to screening all the physical indicators. The overall accuracy, sensitivity and specificity were calculated, respectively, and so were the receiver operator characteristic curve and the area under the curve of the test set. In the prediction model on the efficacy of 1-month treatment of statins for LDL, the sensitivity, 86.86%; and the specificity, 94.83%. In the prediction model on the efficacy of the same treatment for triglyceride, the sensitivity, 71.21%; and the specificity, 73.46%. As to the prediction of total cholesterol, the sensitivity, 94.38%; and the specificity, 96.55%. And in the case of high-density lipoprotein (HDL), the sensitivity, 84.86%; and the specificity, 100%. recursive feature elimination analysis showed that total cholesterol was the most important feature of atorvastatin efficacy of reducing LDL; that HDL was the most important one of its efficacies of reducing triglycerides; that LDL was the most important one of its efficacies of reducing total cholesterol; and that triglyceride was the most important one of its efficacies of reducing HDL. Random-forest can help predict whether atorvastatin efficacy of reducing lipoprotein cholesterol to be qualified after 1-month course of treatment in different individuals.

Comparative efficacy and acceptability of cholinesterase inhibitors and memantine based on dosage in patients with vascular cognitive impairment: a network meta-analysis

BACKGROUND

Considering the lack of direct comparison between cholinesterase inhibitors and memantine in patients with vascular cognitive impairment (VCI), determining how to choose the best treatment plan remains inconclusive. Hence, we conducted the network meta-analysis to compare the efficacy and acceptability of these drugs.

METHODS

PubMed, the Cochrane Central Register of Controlled Trials, Embase and Web of Science were searched for double-blind randomized controlled trials (RCTs) for the treatment of VCI, which involved donepezil, galantamine, rivastigmine, and memantine, from database inception to January 1, 2020. Then, a network meta-analysis based on the frequency method was conducted.

RESULTS

Eleven RCTs were included. Compared with the placebo, in terms of efficacy donepezil 5 mg (standardized mean difference = -1.11, 95% confidence interval = -1.88 to -0.34), donepezil 10 mg (-1.44, -2.31 to -0.56), galantamine 24 mg (-1.99, -3.03 to -0.95), and memantine 20 mg (-1.89, -2.93 to -0.86) were more effective on the cognition of ADAS-cog; and donepezil 5 mg (0.46, 0.12 to 0.81), donepezil 10 mg (0.76, 0.34 to 1.17), and rivastigmine 12mg (0.60, 0.10 to 1.10) exhibited superior benefits on the cognition of MMSE. Donepezil 10 mg (-0.25, -0.44 to -0.06; -1.47, -2.79 to -0.15) exhibited improvements on CDR-SB and EXIT25, respectively. In terms of acceptability, the memantine behaved as the best.

CONCLUSIONS

Donepezil 5 mg, donepezil 10 mg, galantamine 24 mg, memantine 20 mg, and rivastigmine 12 mg have beneficial effects on cognition, and donepezil 10mg provides beneficial effects on executive function and global status. Based on the network meta-analysis, donepezil 10 mg might be the best choice, considering the benefits on cognition function, executive function and global status, but dose-related adverse reactions need to be noted. In the meantime, memantine is a better comprehensive choice, in terms of efficacy and safety acceptability.

OUP accepted manuscript

Subcortical ischemic vascular disease could induce subcortical vascular cognitive impairments (SVCIs), such as amnestic mild cognitive impairment (aMCI) and non-amnestic MCI (naMCI), or sometimes no cognitive impairment (NCI). Previous SVCI studies focused on focal structural lesions such as lacunes and microbleeds, while the functional connectivity networks (FCNs) from functional magnetic resonance imaging are drawing increasing attentions. Considering remarkable variations in structural lesion sizes, we expect that seeking abnormalities in the multiscale hierarchy of brain FCNs could be more informative to differentiate SVCI patients with varied outcomes (NCI, aMCI, and naMCI). Driven by this hypothesis, we first build FCNs based on the atlases at multiple spatial scales for group comparisons and found distributed FCN differences across different spatial scales. We then verify that combining multiscale features in a prediction model could improve differentiation accuracy among NCI, aMCI, and naMCI. Furthermore, we propose a graph convolutional network to integrate the naturally emerged multiscale features based on the brain network hierarchy, which significantly outperforms all other competing methods. In addition, the predictive features derived from our method consistently emphasize the limbic network in identifying aMCI across the different scales. The proposed analysis provides a better understanding of SVCI and may benefit its clinical diagnosis.

Magnetic Resonance Image Feature Analysis under Deep Learning in Diagnosis of Neurological Rehabilitation in Patients with Cerebrovascular Diseases

To explore the impact of magnetic resonance imaging (MRI) image features based on deep learning algorithms on the neurological rehabilitation of patients with cerebrovascular diseases, eighty patients with acute cerebrovascular disease were selected as the research objects. According to whether the patients were with vascular cognitive impairment (VCI), they were divided into VCI group (34 cases) and non-VCI group (46 cases). In addition, based on the convolutional neural network (CNN), a new multimodal CNN image segmentation algorithm was proposed. The algorithm was applied to the segmentation of MRI images of patients with vascular cognitive impairment (VCI) and compared with the segmentation results of CNN and fully CNN (FCN). As a result, the segmentation results of the three different algorithms showed that the Dice coefficient, accuracy, and recall of the multimodal CNN algorithm were 0.78 ± 0.24, 0.81 ± 0.28, and 0.88 ± 0.32, respectively, which were significantly increased compared to those of other two algorithms (P < 0.05). The neurological evaluation results showed that the MMSE and MoCA scores of VCI patients were 15.4 and 14.6 ± 5.31, respectively, which were significantly lower than those of the non-VCI group (P < 0.05). The TMT-a and TMT-b scores of VCI patients were 221.7 and 385.9, respectively, which were significantly higher than those of the non-VCI group (P < 0.05). The FA and MD values of nerve function-related fibers shown in the MRI images of the VCI group were significantly different from those of the non-VCI group (P < 0.05). Therefore, the neurological recovery process of VCI patients was affected by multiple neurocognitive-related fiber structures. To sum up, the multimodal CNN algorithm can sensitively and accurately reflect the degree of neurological impairment in patients with cerebrovascular disease and can be applied to disease diagnosis and neurological evaluation of VCI patients.

[Cerebrovascular disease with neurocognitive impairment]

In the International Classification of Diseases 11th revision in the section «Diseases of the nervous system», it is proposed to distinguish «Cerebrovascular disorder with neurocognitive impairment», which corresponds to both discirculatory encephalopathy (DEP) or chronic cerebral ischemia (CCI) accepted in our country, and also vascular cognitive impairments. The terminology, prevalence, risk factors and pathological basis of the disease are discussed, in particular multiple infarctions, strategic infarctions, cerebral small vessel disease, specific microangiopathies, intracerebral hemorrhage and global hypoperfusion. Post-stroke cognitive impairments are discussed in detail. The article presents relevant data on the pathogenesis of the disease, highlights the issues of clinical and neuroimaging diagnostics. Based on the data presented in the article, we can conclude that the diagnosis of DEP, CCI should be based on the presence of cerebrovascular disease with neurocognitive impairment, which implies the verification of vascular cognitive impairments and reliable neuroimaging signs of cerebrovascular pathology while excluding other causes. Early diagnosis and effective treatment of cerebrovascular disease with neurocognitive impairment (DEP, CCI) is becoming increasingly important, since treatment can slow the progression of the disease and lead to a decrease in the incidence of stroke and dementia.

Caveolin-1, a novel player in cognitive decline

Cognitive decline (CD), which related to vascular dementia, Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis and diabetes mellitus, is a growing health concern that has a great impact on the patients' quality of life. Although extensive efforts, the mechanisms of CD are still far from being clarified, not to mention the effective treatment and prevention strategies. Caveolin-1 (Cav-1), a trans-membrane protein, is a major component of the caveolae structure and scaffolding proteins. Recently, ample evidence depicts a strong correlation between Cav-1 and CD, however, the specific role of Cav-1 in CD has not been clearly examined and how they might be connected have yet to be identified. This review seeks to provide a comprehensive overview about how Cav-1 modulates pathogeneses of CD-associated diseases. In summary, Cav-1 can promote structural and functional plasticity of neurons, improve neurogenesis, relieve mitochondrial dysfunction, inhibit inflammation and suppress oxidative stress, which have shed light on the idea that Cav-1 may be an efficacious therapeutic target to treat CD.

Pro-Neurotensin/Neuromedin N and Risk of Cognitive Impairment in a Prospective Study

BACKGROUND

The neuropeptide neurotensin (NT) has been linked to cardiometabolic disease. Cardiovascular risk factors are being recognized as risk factors for cognitive impairment.

OBJECTIVE

To examine the association of the stable precursor of NT, pro-neurotensin/neuromedin N (pro-NT/NMN), with incident cognitive impairment (ICI).

METHODS

We conducted a prospective nested case-control study in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort. In 2003-2007, REGARDS enrolled 30,239 Black and White adults aged ≥45 years. ICI was identified using a 3-test cognitive battery administered biannually. Baseline pro-NT/NMN was measured by immunoassay in 393 cases of ICI and 490 controls after 3.4 years follow up. Multivariable logistic regression was used to calculate odds ratios (OR) of ICI by pro-NT/NMN quartiles. Race, age, and sex differences were studied with stratified models and interaction testing.

RESULTS

Pro-NT/NMN was higher in Black participants and those with hypertension and diabetes. Women with a 4th versus 1st-quartile pro-NT/NMN had 2.28-fold increased odds of ICI (95% CI 1.08-4.78) after adjusting for risk factors and incident stroke. There was no association of higher pro-NT/NMN quartiles with ICI in the overall group or men. There were no race or age differences in associations.

CONCLUSION

In this biracial population-based study, elevated systemic pro-NT/NMN was associated with more than doubled risk of ICI in women but not men. Others reported sex-specific associations in women for cardiovascular mortality and diabetes with higher pro-NT/NMN, supporting a role for future research on sex differences in the neurotensinergic system.

Imaging of vascular cognitive impairment

Vascular cognitive impairment (VCI) is a major health challenge and represents the second most common cause of dementia. We review the updated imaging classification and imaging findings of different subtypes of VCI. We will focus on the magnetic resonance imaging (MRI) markers of each subtype and highlight the role of advanced MR imaging sequences in the evaluation of these patients. Small vessel dementia appears as white matter hyperintensity, lacunae, microinfarcts, and microbleeds. Large vessel dementia includes strategic infarction and multi-infarction dementias. Hypoperfusion dementia can be seen as watershed infarcts and cortical laminar necrosis. Hemorrhagic dementia results from cerebral amyloid angiopathy and cortical superficial siderosis. Hereditary forms of VCI, caused by gene mutations such as CADASIL, should be suspected when dementia presents in young patients. Mixed dementia is seen in patients with Alzheimer's disease and the coexistence of cerebrovascular disease.

Stroke promotes the development of brain atrophy and delayed cell death in hypertensive rats

Post-stroke cognitive impairment (PSCI) is a major source of disability, affecting up to two thirds of stroke survivors with no available therapeutic options. The condition remains understudied in preclinical models due to its delayed presentation. Although hypertension is a leading risk factor for dementia, how ischemic stroke contributes to this neurodegenerative condition is unknown. In this study, we used a model of hypertension to study the development of PSCI and its mechanisms. Spontaneously hypertensive rats (SHR) were compared to normotensive rats and were subjected to 1-h middle cerebral artery occlusion or sham surgery. Novel object recognition, passive avoidance test and Morris water maze were used to assess cognition. In addition, brain magnetic resonance images were obtained 12-weeks post-stroke and tissue was collected for immunohistochemistry and protein quantification. Stroked animals developed impairment in long-term memory at 4-weeks post-stroke despite recovery from motor deficits, with hypertensive animals showing some symptoms of anhedonia. Stroked SHRs displayed grey matter atrophy and had a two-fold increase in apoptosis in the ischemic borderzone and increased markers of inflammatory cell death and DNA damage at 12 weeks post-stroke. This indicates that preexisting hypertension exacerbates the development of secondary neurodegeneration after stroke beyond its acute effects on neurovascular injury.

Efficacy and safety of butylphthalide as adjunctive therapy for vascular dementia: A protocol for systematic review and meta-analysis

BACKGROUND

Butylphthalide is widely used for the adjunctive treatment of vascular dementia; however, the clinical evidences are not well synthesized yet.

METHODS

We proposed a systematic review and meta-analysis to evaluate the efficacy and safety of butylphthalide as adjunctive therapy for vascular dementia. Seven electronic databases (China National Knowledge Infrastructure, Wanfang database, Chongqing VIP database, China Biomedical Literature Database, Pubmed, EMBASE and Cochrane library) will be searched for eligible randomized controlled trials (RCTs). Required data of included studies will be collected. Quality of studies will be evaluated using Cochrane risk of bias assessment tool. Data synthesis will be performed using Review Manager software. Subgroup analysis and sensitivity analysis will also be carried.

RESULTS

Synthesis results of current available RCTs regarding the efficacy and safety of butylphthalide for the treatment vascular dementia will be provided by this systematic review and meta-analysis.

CONCLUSION

This systematic review and meta-analysis will provide high level evidence of butylphthalide clinical application.

REGISTRATION

PROSPERO CRD42020168947.

Function-based dementia severity assessment for vascular cognitive impairment

BACKGROUND/PURPOSES

Unimpaired activities of daily living (ADL) is essential for the diagnosis of normal cognition and mild cognitive impairment. However, diagnosis according to this concept is difficult to apply to patients comorbid with motor dysfunction. We aim to use a novel ADL questionnaire for operationally diagnosing unimpaired ADL in vascular cognitive impairment with no dementia (VCIND).

METHODS AND PARTICIPANTS

This was a retrospective cohort study with both cross-sectional and long-term follow-up analysis. Patients with cerebrovascular disease with normal cognition (CVDNC), VCIND, and vascular dementia (VaD) were analyzed. Cutoff scores for differentiating different stages of cognitive impairment were compared between the new History-based Artificial Intelligent ADL questionnaire (HAI-ADL) and other tools.

RESULTS

A total of 596 individuals were analyzed, including 40 CVDNC, 167 VCIND, 218 mild, 119 moderate, and 52 severe-dementia patients. The cutoff scores for determining unimpaired ADL in VCIND were 8.5, 3.5, 5, 100, and 60 in HAI-ADL, CDR-SB, IADL, BI, and CASI, respectively. HAI-ADL had the highest correlations with CDR-SB and the CDR staging system compared to other tools. Four models of progression rates from CVDNC/VCIND to VaD revealed it was much higher in the group with HAI-ADL > 8.5 compared to those with HAI-ADL≦8.5 with odds ratios of 3.75, 3.66, 3.31, and 2.77, respectively.

CONCLUSION

Our study showed that HAI-ADL provides an operational determinates unimpaired ADL which is necessary for the diagnosis of VCIND. The predictive value for progression to dementia was proved by a long-term follow-up analysis of the research cohort.

A Deep Learning-Based Model for Classification of Different Subtypes of Subcortical Vascular Cognitive Impairment With FLAIR

Deep learning methods have shown their great capability of extracting high-level features from image and have been used for effective medical imaging classification recently. However, training samples of medical images are restricted by the amount of patients as well as medical ethics issues, making it hard to train the neural networks. In this paper, we propose a novel end-to-end three-dimensional (3D) attention-based residual neural network (ResNet) architecture to classify different subtypes of subcortical vascular cognitive impairment (SVCI) with single-shot T2-weighted fluid-attenuated inversion recovery (FLAIR) sequence. Our aim is to develop a convolutional neural network to provide a convenient and effective way to assist doctors in the diagnosis and early treatment of the different subtypes of SVCI. The experiment data in this paper are collected from 242 patients from the Neurology Department of Renji Hospital, including 78 amnestic mild cognitive impairment (a-MCI), 70 nonamnestic MCI (na-MCI), and 94 no cognitive impairment (NCI). The accuracy of our proposed model has reached 98.6% on a training set and 97.3% on a validation set. The test accuracy on an untrained testing set reaches 93.8% with robustness. Our proposed method can provide a convenient and effective way to assist doctors in the diagnosis and early treatment.

Donepezil attenuates vascular dementia in rats through increasing BDNF induced by reducing HDAC6 nuclear translocation

Vascular dementia (VD) is the second most common dementia disease after Alzheimer's diseases (AD) in the world. Donepezil is used to treat mild to moderate AD, and it has been shown to treat cognitive impairment and memory deficits caused by VD. However, the action mechanism of donepezil against VD has not been clarified. In this study, a bilateral common carotid artery occlusion (BCCAO) model was established in rats to simulate the pathology of VD. Two weeks after the surgery, the rats were administered donepezil (10 mg · kg^-1 · d^-1, ig) for 3 weeks, and then subjected to behavioral tests. We showed that donepezil treatment significantly improved the performance of BCCAO rats in Morris Water Mazes test and Step-down test. Furthermore, we showed that donepezil treatment significantly attenuated neurodegeneration and restored the synapse dendritic spines density in cortex and hippocampus. We revealed that donepezil treatment significantly increased BDNF expression in cortex and hippocampus. Interestingly, donepezil treatment significantly decreased nuclear translocation of HDAC6 and the binding between HDAC6 and BDNF promoter IV in cortex, but not in the hippocampus. The attenuated neurodegeneration by donepezil in cortex and hippocampus might due to the reduced ROS levels and increased phosphorylation of AMPK, whereas increased phosphorylation of AKT was only detected in cortex. In conclusion, our results demonstrate that donepezil attenuates neurodegeneration in cortex and hippocampus via increasing BDNF expression; the regulation of donepezil on HDAC6 occurred in cortex, but not in the hippocampus. This study further clarifies the pharmacological mechanism of donepezil, while also emphasizes the promising epigenetic regulation of HDAC6.

Current status and future prospects of pathophysiology-based neuroprotective drugs for the treatment of vascular dementia

Vascular dementia (VaD) is a progressive neurocognitive clinical syndrome that is caused by a decrease in cerebral blood flow and damage to the neurovascular unit. Given increasing life expectancy, VaD is emerging as one of the leading health problems in society. Despite the high global prevalence of cognitive impairment associated with VaD, diagnosis and treatment still remain limited because of the complexity of mechanisms of neuronal loss. Therefore, advances in our understanding of the pathophysiological mechanisms involved is crucial for the development of new therapeutic strategies. In this review, we highlight the pathophysiology, current pharmacology-based primary and secondary prevention strategies and emerging treatment options for VaD.

Vascular Cognitive Impairment: Information from Animal Models on the Pathogenic Mechanisms of Cognitive Deficits

Vascular cognitive impairment (VCI) is the second most common cause of cognitive deficit after Alzheimer's disease. Since VCI patients represent an important target population for prevention, an ongoing effort has been made to elucidate the pathogenesis of this disorder. In this review, we summarize the information from animal models on the molecular changes that occur in the brain during a cerebral vascular insult and ultimately lead to cognitive deficits in VCI. Animal models cannot effectively represent the complex clinical picture of VCI in humans. Nonetheless, they allow some understanding of the important molecular mechanisms leading to cognitive deficits. VCI may be caused by various mechanisms and metabolic pathways. The pathological mechanisms, in terms of cognitive deficits, may span from oxidative stress to vascular clearance of toxic waste products (such as amyloid beta) and from neuroinflammation to impaired function of microglia, astrocytes, pericytes, and endothelial cells. Impaired production of elements of the immune response, such as cytokines, and vascular factors, such as insulin-like growth factor 1 (IGF-1), may also affect cognitive functions. No single event could be seen as being the unique cause of cognitive deficits in VCI. These events are interconnected, and may produce cascade effects resulting in cognitive impairment.

Vinpocetine in the treatment of poststroke cognitive dysfunction: A protocol for systematic review and meta-analysis

BACKGROUND

Previous clinical trials have reported that vinpocetine can be used for the treatment of cognitive dysfunction. However, its efficacy is still inconclusive. In this systematic review study, we aim to assess its efficacy and safety for the treatment of poststroke cognitive dysfunction (PSCD).

METHODS

We will search the following electronic databases from the inception to the present to evaluate the efficacy and safety of vinpocetine for patients with PSCD. These databases include CENTRAL, EMBASE, MEDILINE, CINAHL, AMED, and four Chinese databases. All randomized controlled trials (RCTs) of vinpocetine for PSCD will be considered for inclusion without the language restrictions. The methodological quality of all included RCTs will be evaluated by the Cochrane risk of bias tool. The 95% confidence intervals will be utilized to calculate the continuous data, the mean difference or standard mean difference, and dichotomous data with risk ratio.

DISSEMINATION AND ETHICS

The results of this review will be disseminated through peer-reviewed journals. Its results may provide important evidence for the clinical practice, as well as the future studies. It does not require ethical approval, because this systematic review will not involve the individual data.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018115224.

Multi-modal neuroimaging of dual-task walking: Structural MRI and fNIRS analysis reveals prefrontal grey matter volume moderation of brain activation in older adults

It has been well established over the last two decades that walking is not merely an automatic, motoric activity; it also utilizes executive function circuits, which play an increasingly important role in walking for older people and those with mobility and cognitive deficits. Dual-task walking, such as walking while performing a cognitive task, is a necessary skill for everyday functioning, and has been shown to activate prefrontal lobe areas in healthy older people. Another well-established point in healthy aging is the loss of grey matter, and in particular loss of frontal lobe grey matter volume. However, the relationship between increased frontal lobe activity during dual-task walking and loss of frontal grey matter in healthy aging remains unknown. In the current study, we combined oxygenated hemoglobin (HbO₂) data from functional near-infrared spectroscopy (fNIRS), taken during dual-task walking, with structural MRI volumetrics in a cohort of healthy older subjects to identify this relationship. We studied fifty-five relatively healthy, older participants (≥65 years) during two separate sessions: fNIRS to measure HbO₂ changes between single-task (i.e., normal walking) and dual-task walking-while-talking, and high-resolution, structural MRI to measure frontal lobe grey matter volumes. Linear mixed effects modeling was utilized to determine the moderation effect of grey matter volume on the change in prefrontal oxygenated hemoglobin between the two walking tasks, while controlling for covariates including task performance. We found a highly significant interaction effect between frontal grey matter volume and task on HbO₂ levels (p < 0.0001). Specifically, increased HbO₂ levels during dual-task compared to single-task walking were associated with reduced frontal grey matter volume. Regional analysis identified bilateral superior and rostral middle gyri as the primary areas driving these results. The findings provide support for the concept of neural inefficiency: in the absence of behavioral gains, grey matter loss in relatively healthy, older individuals leads to over-activation of frontal lobe during a cognitively demanding walking task with established clinical and predictive utility.

Progression in Vascular Cognitive Impairment: Pathogenesis, Neuroimaging Evaluation, and Treatment

Vascular cognitive impairment (VCI) defines an entire spectrum of neurologic disorders from mild cognitive impairment to dementia caused by cerebral vascular disease. The pathogenesis of VCI includes ischemic factors (e.g., large vessel occlusion and small vessel dysfunction); hemorrhagic factors (e.g., intracerebral hemorrhage and subarachnoid hemorrhage); and other factors (combined with Alzheimer's disease). Clinical evaluations of VCI mainly refer to neuropsychological testing and imaging assessments, including structural and functional neuroimaging, with different advantages. At present, the main treatment for VCI focuses on neurological protection, cerebral blood flow reconstruction, and neurological rehabilitation, such as pharmacological treatment, revascularization, and cognitive training. In this review, we discuss the pathogenesis, neuroimaging evaluation, and treatment of VCI.

Prediabetes is associated with post-stroke cognitive impairment in ischaemic stroke patients

AIM

Diabetes mellitus is associated with post-stroke cognitive impairment. To the best of our knowledge, no study has explored the relationship between prediabetes and post-stroke cognitive impairment. The purpose of this study is to explore the association between prediabetes and cognitive impairment in ischaemic stroke patients at 1 month.

METHODS

Two hundred one acute ischaemic stroke patients were consecutively recruited within the first 24 h after admission and were followed up for 1 month. Patients were divided into a diabetes mellitus group, prediabetes group and non-diabetes mellitus group by fasting glucose levels, 2-h postprandial blood glucose levels and glycosylated haemoglobin levels at admission. Cognitive function was evaluated by the Mini-Mental State Examination at 1 month after stroke.

RESULTS

The prediabetes group had a higher risk of post-stroke cognitive impairment than the non-diabetes group (35.7% vs. 18.1%, χ² = 4.252, P = .039). In logistical analyses, prediabetes was associated with post-stroke cognitive impairment after adjusting for potential confounding factors (odds ratio 3.062, 95% confidence interval 1.130-8.299, P = .028).

CONCLUSIONS

Our findings show that prediabetes is associated with post-stroke cognitive impairment and may predict its development at 1 month post-stroke.