Analysis of central mechanism of cognitive training on cognitive impairment after stroke: Resting-state functional magnetic resonance imaging study

Effectiveness and safety of Governor vessel acupuncture therapy for post-stroke cognitive impairment: A meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of Governor vessel acupuncture (GV Ac) in treating post-stroke cognitive impairment (PSCI).

METHODS

There was a total of seven databases examined. Four English databases (Cochrane Library, PubMed, Embase, and Medline) and three Chinese databases (Chinese National Knowledge Infrastructure (CNKI), Chinese Science and Technology Periodical Databases (VIP), and Wan Fang Database) contain all randomized controlled trials (RCTs) comparing Governor vessel acupuncture to other treatments or none acupuncture for PSCI. The exact dates for the search period are from January 1, 2000, to January 1, 2023.Two researchers independently reviewed the literature, gathered RCT data, and performed statistical analysis. All data were analyzed using Review Manager software (Rev Man) 5.3.

RESULTS

This meta-analysis includes a total of 39 trials with 2044 patients. There were 1022 participants in each of the test and control groups. Following 12-120 days of acupuncture treatment, a meta-analysis revealed that the treatment groups (GV Ac combined with conventional treatment groups) significantly increased their scores on the Curative ratio (OR = 3.00, 95 %CI = 2.37-3.79, P = 0.98, I² = 0 %), Montreal Cognitive Assessment (MoCA)(MD = 1.82, 95 %CI = 1.60-2.03, P = 0.11, I² = 25 %), Mini-Mental State Examination (MMSE)(MD = 2.18, 95 %CI = 1.64-2.72, P<0.005, I² = 92 %), and Activity of Daily Living (ADL)(MD = 5.99, 95 %CI = 5.33-6.64, P = 0.19, I² = 26 %).

CONCLUSION

The results suggested that acupuncture on points of the Governor vessel enhanced cognitive function in stroke survivors.

Investigating functional connectivity related to stroke recovery: A systematic review

INTRODUCTION

Stroke recovery is a complex process influenced by various factors, including specific neural reorganization. The objective of this systematic review was to identify important functional connectivity (FC) changes in resting-state fMRI data that were often correlated with motor, emotional, and cognitive outcome improvement.

METHOD

A systematic search using PubMed and SCOPUS databases was conducted to identify relevant studies published between 2010 and 2023.

RESULTS

A total of 766 studies were identified, of which 20 studies (602 S individuals) met the inclusion criteria. Fourteen studies focussed on motor recovery while six on cognitive recovery. All studies reported interhemispheric FC to be strongly associated with motor and cognitive recovery. The preservation and changes of M1-M1 (eight incidences) and M1-SMA (nine incidences) FC were found to be strongly correlated with motor function improvement. For cognitive recovery, restoration and preservation of FC with and between default mode network (DMN)-related regions were important for the process.

CONCLUSIONS

This review identified specific patterns of FC that were consistently reported with recovery of motor and cognitive function. The findings may serve in refining future management strategies to enhance patient outcomes.

Intervention and assessment of executive dysfunction in patients with stroke: A scoping review

Rehabilitation methods for executive dysfunction were focused on cognitive rehabilitation in patients with stroke and traumatic brain injury. However, no reviews have focused on the various rehabilitation methods and assessment of executive function in patients with only stroke and included various study designs. This study aimed to identify various interventions and assessments in patients with stroke and executive dysfunction via a scoping review. We searched for articles using the PubMed, Web of Science, and CINAHL databases. Two reviewers independently screened the articles based on the inclusion and exclusion criteria using the title, abstract, and full text. We subsequently determined the study design, sample size, time since stroke, intervention, and assessment. We extracted 1131 articles, of which 27 articles were selected. The study designs were randomized controlled trials (81.5%), pilot studies (11.1%), and feasibility studies (7.4%), with a total of 599 participants. Interventions varied from cognitive training (22.2%), virtual reality (22.2%), noninvasive brain stimulation (14.8%), and dual-task training (11.1%), with consistent results. The assessments used were the Trail Making Test Part B (70.4%), Stroop Color and Word Test (44.4%), Digit Symbol Test, Frontal Assessment Battery, and Tower of London test (11.1%). In conclusion, this scoping review provided various interventions and assessments in patients with stroke with executive dysfunction.

Engineering Virtuous health habits using Emotion and Neurocognition: Flexibility for Lifestyle Optimization and Weight management (EVEN FLOW)

Interventions to preserve functional independence in older adults are critically needed to optimize 'successful aging' among the large and increasing population of older adults in the United States. For most aging adults, the management of chronic diseases is the most common and impactful risk factor for loss of functional independence. Chronic disease management inherently involves the learning and adaptation of new behaviors, such as adopting or modifying physical activity habits and managing weight. Despite the importance of chronic disease management in older adults, vanishingly few individuals optimally manage their health behavior in the service of chronic disease stabilization to preserve functional independence. Contemporary conceptual models of chronic disease management and health habit theory suggest that this lack of optimal management may result from an underappreciated distinction within the health behavior literature: the behavioral domains critical for initiation of new behaviors (Initiation Phase) are largely distinct from those that facilitate their maintenance (Maintenance Phase). Psychological factors, particularly experiential acceptance and trait levels of openness are critical to engagement with new health behaviors, willingness to make difficult lifestyle changes, and the ability to tolerate aversive affective responses in the process. Cognitive factors, particularly executive function, are critical to learning new skills, using them effectively across different areas of life and contextual demands, and updating of skills to facilitate behavioral maintenance. Emerging data therefore suggests that individuals with greater executive function are better able to sustain behavior changes, which in turn protects against cognitive decline. In addition, social and structural supports of behavior change serve a critical buffering role across phases of behavior change. The present review attempts to address these gaps by proposing a novel biobehavioral intervention framework that incorporates both individual-level and social support system-level variables for the purpose of treatment tailoring. Our intervention framework triangulates on the central importance of self-regulatory functioning, proposing that both cognitive and psychological mechanisms ultimately influence an individuals' ability to engage in different aspects of self-management (individual level) in the service of maintaining independence. Importantly, the proposed linkages of cognitive and affective functioning align with emerging individual difference frameworks, suggesting that lower levels of cognitive and/or psychological flexibility represent an intermediate phenotype of risk. Individuals exhibiting self-regulatory lapses either due to the inability to regulate their emotional responses or due to the presence of executive functioning impairments are therefore the most likely to require assistance to preserve functional independence. In addition, these vulnerabilities will be more easily observable for individuals requiring greater complexity of self-management behavioral demands (e.g. complexity of medication regimen) and/or with lesser social support. Our proposed framework also intuits several distinct intervention pathways based on the profile of self-regulatory behaviors: we propose that individuals with intact affect regulation and impaired executive function will preferentially respond to 'top-down' training approaches (e.g., strategy and process work). Individuals with intact executive function and impaired affect regulation will respond to 'bottom-up' approaches (e.g., graded exposure). And individuals with impairments in both may require treatments targeting caregiving or structural supports, particularly in the context of elevated behavioral demands.

Effects of home-based computerized cognitive training and tai chi exercise on cognitive functions in older adults with mild cognitive impairment

BACKGROUND

A randomized trial was conducted to investigate the effects of computerized cognitive training (CCT) and tai chi exercise (TCE) vs. health education (HE) on cognitive functions in 189 older adults with mild cognitive impairment (MCI).

METHODS

Cognitive functions were assessed by the five-domain Mattis Dementia Rating Scale (MDRS) (attention, initiation/perseveration, construction, conceptualization, and memory) and the modified Telephone Interview of Cognitive Status (TICS-M), while the timed up and go (TUG), Tinetti's balance, activities of daily living (ADLs), and Activities-specific Balance Confidence (ABC) were also evaluated. Each intervention was delivered once a week for 6 months. All outcomes were followed up at 6 and 12 months of the study.

RESULTS

Compared to HE, CCT increased scores on the MDRS's total, initiation/perseveration, construction, and conceptualization domains and on the TICS-M at 6 months and those on the MDRS's total, attention, construction, conceptualization, and memory domains and on the TICS-M at 12 months; TCE increased scores on the MDRS's total and construction domains and on the TICS-M at 6 months and those on the MDRS's total, attention, initiation/perseveration, and conceptualization domains and on the TICS-M at 12 months. Moreover, CCT improved the TUG at 6 and 12 months and Tinetti's balance at 12 months, and TCE improved the TUG at 6 and 12 months, Tinetti's balance, and ABC at 6 and 12 months, and ADLs at 12 months.

CONCLUSIONS

The effects of CCT and TCE on improving global cognition and certain cognitive domains for older MCI adults may have been small but they lasted for at least 12 months.

Neuroplastic Changes Associated With Hybrid Exercise-Cognitive Training in Stroke Survivors With Mild Cognitive Decline: A Randomized Controlled Trial

BACKGROUND

Exercise and cognitive training have been shown to induce neuroplastic changes and modulate cognitive function following stroke. However, it remains unclear whether hybridized exercise-cognitive training facilitates cortical activity and further influences cognitive function after stroke.

OBJECTIVE

The study aimed to investigate the effects of 2 hybridized exercise-cognitive trainings on neuroplastic changes and behavioral outcomes in stroke survivors with mild cognitive decline.

METHODS

This study was a single-blind randomized controlled trial. Stroke survivors were randomly assigned to 1 of 3 groups: (1) sequential exercise-cognitive training (SEQ), (2) dual-task exercise-cognitive training (DUAL), or (3) control group (CON). All groups underwent training 60 min per day, 3 days per week, for a total of 12 weeks. The primary outcome was the resting-state (RS) functional connectivity (FC) in functional magnetic resonance imaging. Secondary behavioral outcomes included cognitive and physical functions.

RESULTS

After 12 weeks of training, patients in the SEQ group (n = 21) exhibited increased RS FC between the left occipital lobe and posterior cingulate gyrus with right parietal lobe, compared to the DUAL (n = 22) and CON (n = 20) groups. Additionally, patients in the DUAL group showed increased FC of the left temporal lobe. However, changes in behavioral outcome measures were non-significant among the 3 groups (all P's > .05).

CONCLUSIONS

This study highlights the distinct neuroplastic mechanisms associated with 2 types of exercise-cognitive hybridized trainings. The pre-post functional magnetic resonance imaging measurements illustrated the time course of neural mechanisms for cognitive recovery in stroke survivors following different exercise-cognitive training approaches. Trial registration. NCT03230253.

Cognitive Computerized Training for Older Adults and Patients with Neurological Disorders: Do the Amount and Training Modality Count? An Umbrella Meta-Regression Analysis

Numerous applications have been created to train cognition and challenge the brain, a process known as computerized cognitive training (CCT). Despite potential positive results, important questions remain unresolved: the appropriate training duration, the efficacy of CCT depending on its type (commercial or developed in-house for the rehabilitation of specific patients) and delivery mode (at-home or on-site), and the patients most likely to benefit such intervention. This study aims to perform an umbrella meta-analysis and meta-regression to determine if the type of CCT, the delivery mode, the amount of training, and participants' age at inclusion influence the improvement of the cognitive function. To do so, we performed a umbrella meta-analysis. One hundred studies were included in this analysis representing 6407 participants. Statistical improvements were found for the different conditions after the training. We do not find statistical difference between the type of intervention or the delivery mode. No dose-response relationship between the total amount of training and the improvement of cognitive functions was found. CCT is effective in improving cognitive function in patients suffering from neurological conditions and in healthy aging. There is therefore an urgent need for health care systems to recognize its therapeutic potential and to evaluate at a larger scale their integration into the clinical pipeline as preventive and rehabilitation tool.

Problem-solving training modifies cognitive functioning and related functional connectivity in healthy adults

Cognitive functioning evolves throughout life. Regular practice of stimulating activities maintains or even strengthens cognitive skills. This study investigated the effects of a cognitive training programme based on complex closed-ended problem solving on innovative thinking. To this end, using partial least squares variance-based structural equation modeling, we first evaluated in 83 healthy adults how inhibition, cognitive flexibility, and reasoning were related to the distinct dimensions of innovative thinking. Second, we assessed how these interactions were modified after cognitive training based on problem solving in a subgroup of 16 subjects compared to leisure activity based on crossword solving in another subgroup of 15 subjects. Third, in a pilot fMRI study, we evaluated changes in brain connectivity at rest as a result of training in the problem solving group. Data on cognitive measures showed that innovative thinking was influenced by reasoning in control subjects, whereas it was influenced by cognitive flexibility following problem-solving training. These findings highlight that a cognitive intervention based on complex closed-ended problem solving promotes innovative thinking by changing the way subjects recruit and use relevant cognitive processes. Modifications in the resting-state connectivity of attention, default mode and visual networks were observed in the problem solving group.

American Speech-Language-Hearing Association Clinical Practice Guideline: Cognitive Rehabilitation for the Management of Cognitive Dysfunction Associated With Acquired Brain Injury

BACKGROUND

Cognitive-communication impairments following acquired brain injury (ABI) can have devastating effects on a person's ability to participate in community, social, vocational, and academic preinjury roles and responsibilities. Guidelines for evidence-based practices are needed to assist speech-language pathologists (SLPs) and other rehabilitation specialists in the delivery of cognitive rehabilitation for the adult population.

PURPOSE

The American Speech-Language-Hearing Association, in conjunction with a multidisciplinary panel of subject matter experts, developed this guideline to identify best practice recommendations for the delivery of cognitive rehabilitation to adults with cognitive dysfunction associated with ABI.

METHOD

A multidisciplinary panel identified 19 critical questions to be addressed in the guideline. Literature published between 1980 and 2020 was identified based on a set of a priori inclusion/exclusion criteria, and main findings were pooled and organized into summary of findings tables. Following the principles of the Grading of Recommendations Assessment, Development and Evaluation Evidence to Decision Framework, the panel drafted recommendations, when appropriate, based on the findings, overall quality of the evidence, balance of benefits and harms, patient preferences, resource implications, and the feasibility and acceptability of cognitive rehabilitation.

RECOMMENDATIONS

This guideline includes one overarching evidence-based recommendation that addresses the management of cognitive dysfunction following ABI and 11 subsequent recommendations focusing on cognitive rehabilitation treatment approaches, methods, and manner of delivery. In addition, this guideline includes an overarching consensus-based recommendation and seven additional consensus recommendations highlighting the role of the SLP in the screening, assessment, and treatment of adults with cognitive dysfunction associated with ABI. Future research considerations are also discussed.

Computer-assisted training of executive functions in adult patients with non-progressive acquired brain damage - a pilot study on efficacy of a new therapeutic application

Executive dysfunction is most often caused by post-traumatic or post-stroke damage to the prefrontal regions of the brain. The aim of this study was to compare the efficacy of two computer-assisted therapy programs for executive dysfunctions in patients with acquired brain injury. Patients were trained using either a newly developed application ExeSystem (designed to help improve the ability to manage and control one's own behavior by performing tasks imitating natural, everyday situations) or a combination of two commercial applications RehaCom and CogniPlus. Data collected after a three-week period of therapy conducted in two 15-person groups of participants indicated comparable efficacy of both therapy programs in improving quality of daily functioning, executive attention, as well as planning and problem-solving but not memory. The improvement in social competence (p = .028) was the only advantage of therapy with the ExeSystem. Therapeutic interactions using computer programs were shown to be positively evaluated by patients (p < .01). This study confirmed at least equal efficacy of computer-based executive function therapy using ExeSystem compared to RehaCom and CogniPlus. However, despite the implementation of a more ecological and comprehensive approach to the content of a new application, the benefits of this approach were limited.

Occupational therapy for cognitive impairment in stroke patients

BACKGROUND

Cognitive impairment is a frequent consequence of stroke and can impact on a person's ability to perform everyday activities. Occupational therapists use a range of interventions when working with people who have cognitive impairment poststroke. This is an update of a Cochrane Review published in 2010.

OBJECTIVES

To assess the impact of occupational therapy on activities of daily living (ADL), both basic and instrumental, global cognitive function, and specific cognitive abilities in people who have cognitive impairment following a stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register, CENTRAL, MEDLINE, Embase, four other databases (all last searched September 2020), trial registries, and reference lists.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials that evaluated an intervention for adults with clinically defined stroke and confirmed cognitive impairment. The intervention needed either to be provided by an occupational therapist or considered within the scope of occupational therapy practice as defined in the review. We excluded studies focusing on apraxia or perceptual impairments or virtual reality interventions as these are covered by other Cochrane Reviews. The primary outcome was basic activities of daily living (BADL) such as dressing, feeding, and bathing. Secondary outcomes were instrumental ADL (IADL) (e.g. shopping and meal preparation), community integration and participation, global cognitive function and specific cognitive abilities (including attention, memory, executive function, or a combination of these), and subdomains of these abilities. We included both observed and self-reported outcome measures.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies that met the inclusion criteria, extracted data, and assessed the certainty of the evidence. A third review author moderated disagreements if consensus was not reached. We contacted trial authors for additional information and data, where available. We assessed the certainty of key outcomes using GRADE.  MAIN RESULTS: We included 24 trials from 11 countries involving 1142 (analysed) participants (two weeks to eight years since stroke onset). This update includes 23 new trials in addition to the one study included in the previous version. Most were parallel randomised controlled trials except for one cross-over trial and one with a two-by-two factorial design. Most studies had sample sizes under 50 participants. Twenty studies involved a remediation approach to cognitive rehabilitation, particularly using computer-based interventions. The other four involved a compensatory and adaptive approach. The length of interventions ranged from 10 days to 18 weeks, with a mean total length of 19 hours. Control groups mostly received usual rehabilitation or occupational therapy care, with a few receiving an attention control that was comparable to usual care; two had no intervention (i.e. a waiting list). Apart from high risk of performance bias for all but one of the studies, the risk of bias for other aspects was mostly low or unclear.  For the primary outcome of BADL, meta-analysis found a small effect on completion of the intervention with a mean difference (MD) of 2.26 on the Functional Independence Measure (FIM) (95% confidence interval (CI) 0.17 to 4.22; P = 0.03, I2 = 0%; 6 studies, 336 participants; low-certainty evidence). Therefore, on average, BADL improved by 2.26 points on the FIM that ranges from 18 (total assist) to 126 (complete independence). On follow-up, there was insufficient evidence of an effect at three months (MD 10.00, 95% CI -0.54 to 20.55; P = 0.06, I2 = 53%; 2 studies, 73 participants; low-certainty evidence), but evidence of an effect at six months (MD 11.38, 95% CI 1.62 to 21.14, I2 = 12%; 2 studies, 73 participants; low-certainty evidence). These differences are below 22 points which is the established minimal clinically important difference (MCID) for the FIM for people with stroke. For IADL, the evidence is very uncertain about an effect (standardised mean difference (SMD) 0.94, 95% CI 0.41 to 1.47; P = 0.0005, I2 = 98%; 2 studies, 88 participants). For community integration, we found insufficient evidence of an effect (SMD 0.09, 95% CI -0.35 to 0.54; P = 0.68, I2 = 0%; 2 studies, 78 participants). There was an improvement of clinical importance in global cognitive functional performance after the intervention (SMD 0.35, 95% CI 0.16 to 0.54; P = 0.0004, I2 = 0%; 9 studies, 432 participants; low-certainty evidence), equating to 1.63 points on the Montreal Cognitive Assessment (MoCA) (95% CI 0.75 to 2.52), which exceeds the anchor-based MCID of the MoCA for stroke rehabilitation patients of 1.22. We found some effect for attention overall (SMD -0.31, 95% CI -0.47 to -0.15; P = 0.0002, I2 = 20%; 13 studies, 620 participants; low-certainty evidence), equating to a difference of 17.31 seconds (95% CI 8.38 to 26.24), and for executive functional performance overall (SMD 0.49, 95% CI 0.31 to 0.66; P < 0.00001, I2 = 74%; 11 studies, 550 participants; very low-certainty evidence), equating to 1.41 points on the Frontal Assessment Battery (range: 0-18). Of the cognitive subdomains, we found evidence of effect of possible clinical importance, immediately after intervention, for sustained visual attention (moderate certainty) equating to 15.63 seconds, for working memory (low certainty) equating to 59.9 seconds, and thinking flexibly (low certainty), compared to control.

AUTHORS' CONCLUSIONS

The effectiveness of occupational therapy for cognitive impairment poststroke remains unclear. Occupational therapy may result in little to no clinical difference in BADL immediately after intervention and at three and six months' follow-up. Occupational therapy may slightly improve global cognitive performance of a clinically important difference immediately after intervention, likely improves sustained visual attention slightly, and may slightly increase working memory and flexible thinking after intervention. There is evidence of low or very low certainty or insufficient evidence for effect on other cognitive domains, IADL, and community integration and participation.  Given the low certainty of much of the evidence in our review, more research is needed to support or refute the effectiveness of occupational therapy for cognitive impairment after stroke. Future trials need improved methodology to address issues including risk of bias and to better report the outcome measures and interventions used.

Enhanced Medial Prefrontal Cortex and Hippocampal Activity Improves Memory Generalization in APP/PS1 Mice: A Multimodal Animal MRI Study

Memory generalization allows individuals to extend previously learned movement patterns to similar environments, contributing to cognitive flexibility. In Alzheimer’s disease (AD), the disturbance of generalization is responsible for the deficits of episodic memory, causing patients with AD to forget or misplace things, even lose track of the way home. Cognitive training can effectively improve the cognition of patients with AD through changing thinking mode and memory flexibility. In this study, a T-shaped maze was utilized to simulate cognitive training in APP/PS1 mice to elucidate the potential mechanisms of beneficial effects after cognitive training. We found that cognitive training conducted by a T-shaped maze for 4 weeks can improve the memory generalization ability of APP/PS1 mice. The results of functional magnetic resonance imaging (fMRI) showed that the functional activity of the medial prefrontal cortex (mPFC) and hippocampus was enhanced after cognitive training, and the results of magnetic resonance spectroscopy (MRS) showed that the neurochemical metabolism of N-acetyl aspartate (NAA) and glutamic acid (Glu) in mPFC, hippocampus and reuniens (Re) thalamic nucleus were escalated. Furthermore, the functional activity of mPFC and hippocampus was negatively correlated with the escape latency in memory generalization test. Therefore, these results suggested that cognitive training might improve memory generalization through enhancing the functional activity of mPFC and hippocampus and increasing the metabolism of NAA and Glu in the brain regions of mPFC, hippocampus and Re nucleus.

Who, what, when, where, why, and how: a systematic review of the quality of post-stroke cognitive rehabilitation protocols

BACKGROUND

. Rehabilitation research findings are not routinely incorporated into clinical practice. A key barrier is the quality of reporting in the original study, including who provided the intervention, what it entailed, when and where it occurred, how patient outcomes were monitored, and why the intervention was efficacious.

OBJECTIVES

. To facilitate clinical implementation of post-stroke cognitive rehabilitation research, we undertook a review to examine the quality of intervention reporting in this literature.

METHODS

. Four databases were systematically searched, identifying 27 randomised controlled trials of post-stroke cognitive rehabilitation. The quality of intervention protocol descriptions in each study was independently rated by 2 of the authors using the 12-item Template for Intervention Description and Replication (TIDieR) checklist.

RESULTS

.Why, when, and where items were reported in more than 70% of interventions, what materials and procedures used was described in 50% to 70%, how items were described in approximately half of the interventions, and who provided interventions was reported in 22% of studies. No study addressed all 12 TIDieR items. "Active ingredients" that may further characterise an intervention and the potential mechanisms of action included restorative training, massed practice, feedback, and tailoring demands (present in approximately 50% of studies).

CONCLUSIONS

. Descriptions of intervention protocols are variable and frequently insufficient, thereby restricting the ability to understand, replicate, and implement evidence-based cognitive rehabilitation. Use of reporting checklists to address this barrier to research translation is a readily achievable and effective means to advance post-stroke care.

A Novel Active Rehabilitation Model for Stroke Patients Using Electroencephalography Signals and Deep Learning Technology

The main clinical manifestations of stroke are motor, language, sensory, and mental disorders. After treatment, in addition to being conscious, other symptoms will still remain in varying degrees. This is the sequelae of stroke, including numbness, facial paralysis, central paralysis, and central paralysis. If the sequelae of stroke are not treated effectively, they can easily develop into permanent sequelae. Most of the affected people have sequelae, and most of them have symptoms of upper limb paralysis. Therefore, it is of great significance to study how to carry out effective rehabilitation training for stroke patients to reduce the disease and even restore their motor function. Based on this background, this research aims to use deep learning technology to design a stroke rehabilitation model based on electroencephalography (EEG) signals. First, the patient's EEG signal will be preprocessed. Then, an improved deep neural network model (IDNN) is used to get the EEG classification results. The traditional DNN model construction process is simple and suitable for scenarios where there is no special requirement for the data format, but the generalization of a single DNN model is usually poor. Large margin support vector machine (LM_SVM) is an extension method of support vector machine (SVM), suitable for any occasion. By optimizing the edge distribution, better generalization performance can be obtained. Taking into account the advantages of DNN and LM_SVM and the high aliasing characteristics of stroke data, an improved DNN model is proposed. Finally, based on the EEG recognition result of the model, the rehabilitation equipment is controlled to assist the patient in rehabilitation treatment. The experimental results verify the superiority of the EEG classification model used, and further prove that this research has good practical value.

Efficacy of a Training on Executive Functions in Potentiating Rehabilitation Effects in Stroke Patients

Cognitive impairment after a stroke has a direct impact on patients' disability. In particular, impairment of Executive Functions (EFs) interferes with re-adaptation to daily life. The aim of this study was to explore whether adding a computer-based training on EFs to an ordinary rehabilitation program, regardless of the specific brain damage and clinical impairment (motor, language, or cognitive), could improve rehabilitation outcomes in patients with stroke. An EF training was designed to have minimal motor and expressive language demands and to be applied to a wide range of clinical conditions. A total of 37 stroke patients were randomly assigned to two groups: a training group, which performed the EF training in addition to the ordinary rehabilitation program (treatment as usual), and a control group, which performed the ordinary rehabilitation exclusively. Both groups were assessed before and after the rehabilitation program on neuropsychological tests covering multiple cognitive domains, and on functional scales (Barthel index, Functional Independence Measure). The results showed that only patients who received the training improved their scores on the Attentional Matrices and Phonemic Fluency tests after the rehabilitation program. Moreover, they showed a greater functional improvement in the Barthel scale as well. These results suggest that combining an EF training with an ordinary rehabilitation program potentiates beneficial effects of the latter, especially in promoting independence in activities of daily living.

Efficacy of computerized cognitive training on improving cognitive functions of stroke patients: A systematic review and meta-analysis of randomized controlled trials

AIM

To evaluate the effects of computerized cognitive training on the cognitive functions of stroke patients.

BACKGROUND

With increased publications on computerized cognitive training, a meta-analysis is essential to determine the effects of computerized cognitive training among stroke patients.

DESIGN

A systematic review and meta-analysis of randomized controlled studies.

DATA SOURCES

Cochrane Library, Pubmed, EBSCO, Scopus, China National Knowledge Infrastructure, China Biology Medicine disc and Wanfang Database were explored to search for research studies from inception to January 2020.

REVIEW METHODS

Six outcomes indicators were considered to determine the effects of computerized cognitive training. Two reviewers were selected to search and independently appraise the available articles from various databases. Meta-analysis was performed using the RevMan 5.3 software.

RESULTS

A total of 622 patients with 17 studies were included. Computerized cognitive training significantly improves global cognition, working memory, attention and executive function of stroke patients. However, there was inadequate evidence to demonstrate any effects of computerized cognitive training on activities of daily living and depression.

CONCLUSION

Computerized cognitive training improves the cognitive functions of stroke patients. However, further research studies are needed to confirm its efficacy in activities of daily living as well as on alleviating depression.

Developing of Focal Ischemia in the Hippocampus or the Amygdala Reveals a Regional Compensation Rule for Fear Memory Acquisition

Circuit compensation is often observed in patients with acute ischemic stroke, suggesting the importance of the interaction between brain regions. Also, contextual fear memory is an association between multisensory contexts and fearful stimuli, for which the interaction between the hippocampus and the amygdala is believed to be critical. To understand how focal ischemia in one region could influence the other region, we used a modified photo-thrombosis to induce focal ischemia in the hippocampus or the amygdala or both in freely-moving rats. We found that the learning curve and short-term memory (STM) were not affected in the rats although focal ischemia was induced 5 h before learning in either the hippocampus or the amygdala; these were impaired by the induction of ischemia in both the regions. Furthermore, the learning curve and STM were impaired when ischemia was induced 24 h before learning in either the hippocampus or the amygdala when the synaptic transmission was altered in one region because of ischemia in the other region. These results suggest that the circuit compensation between the hippocampus and the amygdala is critical for fear memory acquisition.

Reliability, sensitivity, and predictive value of fMRI during multiple object tracking as a marker of cognitive training gain in combination with tDCS in stroke survivors

Computerized cognitive training (CCT) combined with transcranial direct current stimulation (tDCS) has showed some promise in alleviating cognitive impairments in patients with brain disorders, but the robustness and possible mechanisms are unclear. In this prospective double-blind randomized clinical trial, we investigated the feasibility and effectiveness of combining CCT and tDCS, and tested the predictive value of and training-related changes in fMRI-based brain activation during attentive performance (multiple object tracking) obtained at inclusion, before initiating training, and after the three-weeks intervention in chronic stroke patients (>6 months since hospital admission). Patients were randomized to one of two groups, receiving CCT and either (a) tDCS targeting left dorsolateral prefrontal cortex (1 mA), or (b) sham tDCS, with 40s active stimulation (1 mA) before fade out of the current. Of note, 77 patients were enrolled in the study, 54 completed the cognitive training, and 48 completed all training and MRI sessions. We found significant improvement in performance across all trained tasks, but no additional gain of tDCS. fMRI-based brain activation showed high reliability, and higher cognitive performance was associated with increased tracking-related activation in the dorsal attention network and default mode network as well as anterior cingulate after compared to before the intervention. We found no significant associations between cognitive gain and brain activation measured before training or in the difference in activation after intervention. Combined, these results show significant training effects on trained cognitive tasks in stroke survivors, with no clear evidence of additional gain of concurrent tDCS.

Post Stroke Rehabilitation Using Computer-based Cognitive Intervention (CBCI): A Systematic Review

Background:

Cognitive impairment as a consequence of stroke is a major cause affecting the patient’s functional independence, activity participation, daily living skills, and occupation. Almost 75% of post-stroke patients are diagnosed with significant cognitive impairment, which includes problems with attention, orientation, memory, language, and perception. Along with effective pharmaceutical cures, cognitive intervention as a part of rehabilitation approaches that may prevent, delay, or treat cognitive impairment is becoming increasingly important. Many studies have reported improvement in cognitive functions of post-stroke patients after using computer-based cognitive intervention (CBCI). CBCI can be an effective add-on to available rehabilitation programs.

Objective:

This article provides reviews related to relevant literature and, represents a structure to specify the efficacy of CBCI for the rehabilitation of post-stroke patients for future research.

Methods:

We searched many search engines namely MEDLINE, Web of Science, clinical key and The Cochrane Library, for studies investigating the effect of cognitive intervention based on a computer program for post-stroke patients. The results of selected studies were summarized. Total 19 publications from January 2007 to January 2019 are included in this review. The search terms entered were a combination of these search areas that defined (1) the population as adults who had suffered a stroke and cognitive dysfunction, (2) intervention search term included cognitive abilities, cognitive training, and computer-based training; computer-based cognitive intervention for rehabilitation.

Results:

The results after computer-based training showed improvement in various cognitive functions such as; memory, attention and executive functions of post-stroke patients. However, a significant difference between the study groups has not been observed in all the studies. Most studies analyzed in this research project indicated that such interventions might contribute to the improvement of cognitive function, especially attention concentration and memory. Of the 19 kinds of research that discussed CBCI outcomes 18 found significant improvements for one or more cognitive functions. When the effect size for CBCI was reported, effects were large in comparison to other traditional cognitive interventions of post-stroke patients.

Conclusion:

Studies related to cognitive functions strongly support CBCI except few have reported a significant difference. The review of all the studies suggests that CBCI may help to change the functional aspect of post-stroke patients by improving their cognitive functions. In this field, it is a challenge to conduct well designed and sufficiently powered studies due to low budgets availability, the limited number of available patients, heterogeneity of the population, and ethical considerations. Future studies should examine all the challenges, limitations, and valuable insights into the study and emphasize the need for a carefully designed computer-based cognitive intervention program for the future. Future studies should target to compare CBCI with active and passive control conditions and include a larger sample size.

Effectiveness of computer-based training on post-stroke cognitive rehabilitation: A systematic review and meta-analysis

A systematic review and meta-analysis based on randomized controlled trials (RCTs) from the last 10 years was conducted to identify the effect of computer-based training compared to routine methods on post-stroke cognitive rehabilitation and to provide recommendations for future research. A literature search was performed in the Cochrane Library, EMBASE, PubMed, EBSCO (CINAHL), and Web of Science that focused on studies comparing the effects of computerized cognitive training and routine methods in stroke survivors. After extraction of the study characteristics and methodological quality evaluation, a meta-analysis was conducted using the standard model based on the level of the overall cognitive domain. Ten out of 201 studies were included in the systematic review, with a total of 600 stroke survivors. The average age of the participants ranged from 42.1 to 66 years old, 305 participants used the computer-based training method, and males accounted for approximately 58.5%. All studies compared the baseline characteristics of participants at the onset of their studies, and no significant difference was shown. Six studies that reported the results for the overall cognitive domain were further analyzed by meta-analysis. The outcome of the meta-analysis showed that the effect size was 0.61 with a 95% confidence interval [-0.18, 0.35], and the P value (P = 0.54) indicated no significant difference between the control group and the computer-based cognitive training group. The results of the meta-analysis, based on a limited number of studies, did not show significant superiority of computer-based cognitive training compared to the traditional method in post-stroke patients. More high-quality studies focusing on different illness phases and various types of intervention software should be conducted to improve the meta-analysis and to explore the influence of computer-based cognitive training by subgroup analysis.Abbreviation: CBCT: Computer-based cognitive training; PICOS: Participants, interventions, comparisons, outcomes, and study design.

Behavioral and Neural Correlates of Cognitive Training and Transfer Effects in Stroke Patients

Stroke lesions are frequently followed by cognitive impairments. Cognitive training is a non-pharmacological intervention that can promote neural compensation mechanisms and strategies to remediate cognitive impairments. The aims of this study were: (1) To investigate the cognitive performance, generalization effects, and neural correlates of semantic organization strategy training (SOST) in patients with chronic left frontoparietal stroke and healthy controls (HC); and (2) to compare the behavioral effects and neural correlates of SOST with an active control psychoeducation intervention (PI). In this randomized controlled study, all participants were randomly allocated into two groups, one group received SOST, and the other received PI intervention. Participants underwent two fMRI sessions, one prior and the other, after intervention. In each fMRI session, images were obtained during memory encoding task using a list of semantically related words. We found improved post-intervention memory performance in participants that received SOST (both patients and controls), indicated by number of words recalled, word clustering scores, and performance in a generalization task. The fMRI analysis revealed negative correlation between task performance and regions of the default-mode network. These results suggest that cognitive training using semantic organization strategy can improve episodic memory performance and promote potential functional neuroplasticity in patients with ischemic stroke lesions. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03644290.

Computer-based cognitive interventions in acquired brain injury: A systematic review and meta-analysis of randomized controlled trials

Introduction

Acquired brain injury (ABI) leads to cognitive deficits in a great variety of cognitive functions. Interventions aimed at reducing such deficits include the use of computer-based cognitive interventions. The present work synthetizes and quantitively analyses the effect of computer-based cognitive interventions in ABI.

Methods

PubMed, Scopus, Web of Science, ProQuest and Ovid databases were searched for randomized controlled trials (RCT) addressing this issue. A total number of 8 randomized-controlled trials were included for systematic review and meta-analysis. Univariate meta-analyses were conducted for every cognitive function, producing aggregates when a study contributed more than one effect size per cognitive domain.

Results

Random-effects meta-analyses showed an improvement of Visual and Verbal working memory, while other domains like Attention, Processing speed, Executive functions and Memory were not benefited by the interventions.

Conclusions

Computer-based cognitive interventions might be a beneficial intervention for ABI population to improve Visual and Verbal working memory, although no effect was found in other cognitive domains. Implications and possible future directions of the research are discussed.

[Multimodal stimulation in the neurorehabilitation of patients with poststroke cognitive impairment]

Loss of functional activity after a stroke is a leading cause of disability in adults worldwide. Particular attention is currently being paid to post-stroke cognitive impairment. Approaches based on multimodal exposure are increasingly being used when planning rehabilitation programs, which makes it possible to comprehensively cover the entire spectrum of existing neurological disorders in patients and enables to achieve a more effective recovery of functional activity after a stroke.

Pragmatic Solutions for Stroke Recovery and Improved Quality of Life in Low- and Middle-Income Countries-A Systematic Review

Background: Given the limited healthcare resources in low and middle income countries (LMICs), effective rehabilitation strategies that can be realistically adopted in such settings are required. Objective: A systematic review of literature was conducted to identify pragmatic solutions and outcomes capable of enhancing stroke recovery and quality of life of stroke survivors for low- and middle- income countries. Methods: PubMed, HINARI, and Directory of Open Access Journals databases were searched for published Randomized Controlled Trials (RCTs) till November 2018. Only completed trials published in English with non-pharmacological interventions on adult stroke survivors were included in the review while published protocols, pilot studies and feasibility analysis of trials were excluded. Obtained data were synthesized thematically and descriptively analyzed. Results: One thousand nine hundred and ninety six studies were identified while 347 (65.22% high quality) RCTs were found to be eligible for the review. The most commonly assessed variables (and outcome measure utility) were activities of daily living [75.79% of the studies, with Barthel Index (37.02%)], motor function [66.57%; with Fugl Meyer scale (71.88%)], and gait [31.12%; with 6 min walk test (38.67%)]. Majority of the innovatively high technology interventions such as robot therapy (95.24%), virtual reality (94.44%), transcranial direct current stimulation (78.95%), transcranial magnetic stimulation (88.0%) and functional electrical stimulation (85.00%) were conducted in high income countries. Several traditional and low-cost interventions such as constraint-induced movement therapy (CIMT), resistant and aerobic exercises (R&AE), task oriented therapy (TOT), body weight supported treadmill training (BWSTT) were reported to significantly contribute to the recovery of motor function, activity, participation, and improvement of quality of life after stroke. Conclusion: Several pragmatic, in terms of affordability, accessibility and utility, stroke rehabilitation solutions, and outcome measures that can be used in resource-limited settings were found to be effective in facilitating and enhancing post-stroke recovery and quality of life.

Functional connectivity of the retrosplenial cortex in rats with ischemic stroke is improved by electroacupuncture

BACKGROUND

The aim of this study was to investigate the central mechanism underlying the putative beneficial effects of electroacupuncture (EA) on learning and memory ability of rats with ischemic stroke-induced cognitive deficits by resting-state functional magnetic resonance imaging (fMRI).

METHODS

A rat model of middle cerebral artery occlusion (MCAO)-induced cognitive deficit (MICD) was established. Rats were randomly assigned into a sham-operated control group (SC group, n = 12), untreated MICD model group (MICD group, n = 12), and MICD group receiving EA treatment at GV20 and GV24 (MICD + EA group, n = 12).

RESULTS

Compared to the MICD group, rats in the MICD + EA group receiving EA at GV20 and GV24 exhibited significantly shortened escape latency times and crossed the position of the platform a significantly increased number of times during the Morris water maze test on the 14th day after EA, which suggested EA could significantly improve spatial learning and memory ability. Furthermore, compared to the MICD group, functional connectivity of the left retrosplenial cortex (RSC) with the left hippocampus, left RSC, right RSC, left cingulate gyrus, right cingulate gyrus, right tegmentum of midbrain, and right visual cortex was increased in the MICD + EA group; the MICD group showed decreased functional connectivity of the left RSC with the left hippocampus, right hippocampus, left RSC, right RSC, right amygdaloid body, left visual cortex, and right visual cortex.

CONCLUSION

These findings suggest that EA at GV20 and GV24 might improve the learning and memory ability of MICD rats by increasing the functional connectivity between the RSC and hippocampus, cingulate gyrus and midbrain, which is encouraging for the potential treatment for cognitive impairment secondary to ischemia stroke.

Decreasing postoperative cognitive deficits after heart surgery: protocol for a randomized controlled trial on cognitive training

Background

The occurrence of postoperative cognitive deficits, especially after heart surgery, has been demonstrated in several studies. These deficits can clearly be noticed by the patients and by their close relatives in daily life. Furthermore, postoperative cognitive deficits can decrease quality of life in social functioning and earning capacity. The aim of this study is to investigate whether early postoperative cognitive training can reduce subjective and objective postoperative cognitive deficits.

Methods

The proposed study is a multicenter, two-arm, randomized controlled trial involving 144 elderly patients undergoing elective heart-valve surgery with extracorporeal circulation. Patients will be assigned to either a training group or a control group. The intervention involves paper-and-pencil-based cognitive training, which is conducted for 36 min over a period of 18 days. The training starts about 1 week after surgery and is carried out during the hospitalized rehabilitation phase. The control group will not receive cognitive training or a placebo intervention. A detailed assessment of psychological functions and health-related quality of life prior to surgery at discharge from rehabilitation and 3 and 12 months after discharge will be performed. The primary outcome of this trial is the training effect on objective cognitive functions at discharge from rehabilitation. Secondary outcomes are the training effect on objective and subjective cognitive functions (3 and 12 months after discharge), depression, health-related quality of life, and the impact of perioperative cerebral ischemia on the training effect. Perioperative cerebral ischemia will be measured with postoperative magnetic resonance imaging including diffusion-weighted sequences.

Discussion

Should it be shown that our cognitive training can improve postoperative cognitive deficits and quality of life, one possibility could be to integrate this intervention into early rehabilitation. Furthermore, we hope that the investigation of perioperative ischemia by diffusion-weighted magnetic resonance imaging will improve our understanding of neurobiological factors influencing the course of postoperative cognitive plasticity.

Trial registration

German Clinical Trials Register (DRKS), DRKS00015512. Retrospectively registered on 21 September 2018.

Effects of Mnemonic Strategy Training on Brain Activity and Cognitive Functioning of Left-Hemisphere Ischemic Stroke Patients

Memory dysfunction is one of the main cognitive impairments caused by stroke, especially associative memory. Therefore, cognitive training, such as face-name mnemonic strategy training, could be an important intervention for this group of patients. The goal of this study was to evaluate the behavioral effects of face-name mnemonic strategy training, along with the neural substrate behind these effects, in the left frontoparietal lobe stroke patients. Volunteers underwent 2 sessions of functional magnetic resonance imaging (fMRI) during face-name association task: one prior and the other after the cognitive training. The fMRI followed a block design task with three active conditions: trained face-name pairs, untrained face-name pairs, and a couple of repeated face-name pairs. Prior to each fMRI session, volunteers underwent neuropsychological assessment. Training resulted in better performance on delayed memory scores of HVLT-R, and on recognition on a generalization strategy task, as well as better performance in the fMRI task. Also, trained face-name pairs presented higher activation after training in default-mode network regions, such as the posterior cingulate cortex, precuneus, and angular gyrus, as well as in lateral occipital and temporal regions. Similarly, untrained face-name pairs also showed a nonspecific training effect in the right superior parietal cortex, right supramarginal gyrus, anterior intraparietal sulcus, and lateral occipital cortex. A correlation between brain activation and task performance was also found in the angular gyrus, superior parietal cortex, anterior intraparietal sulcus, and lateral occipital cortex. In conclusion, these results suggest that face-name mnemonic strategy training has the potential to improve memory performance and to foster brain activation changes, by the recruitment of contralesional areas from default-mode, frontoparietal, and dorsal attention networks as a possible compensation mechanism.

Optogenetic fMRI and electrophysiological identification of region-specific connectivity between the cerebellar cortex and forebrain

Complex animal behavior is produced by dynamic interactions between discrete regions of the brain. As such, defining functional connections between brain regions is critical in gaining a full understanding of how the brain generates behavior. Evidence suggests that discrete regions of the cerebellar cortex functionally project to the forebrain, mediating long-range communication potentially important in motor and non-motor behaviors. However, the connectivity map remains largely incomplete owing to the challenge of driving both reliable and selective output from the cerebellar cortex, as well as the need for methods to detect region specific activation across the entire forebrain. Here we utilize a paired optogenetic and fMRI (ofMRI) approach to elucidate the downstream forebrain regions modulated by activating a region of the cerebellum that induces stereotypical, ipsilateral forelimb movements. We demonstrate with ofMRI, that activating this forelimb motor region of the cerebellar cortex results in functional activation of a variety of forebrain and midbrain areas of the brain, including the hippocampus and primary motor, retrosplenial and anterior cingulate cortices. We further validate these findings using optogenetic stimulation paired with multi-electrode array recordings and post-hoc staining for molecular markers of activated neurons (i.e. c-Fos). Together, these findings demonstrate that a single discrete region of the cerebellar cortex is capable of influencing motor output and the activity of a number of downstream forebrain as well as midbrain regions thought to be involved in different aspects of behavior.

Effects and mechanism of the HECT study (hybrid exercise-cognitive trainings) in mild ischemic stroke with cognitive decline: fMRI for brain plasticity, biomarker and behavioral analysis

Purpose

Cognitive decline after stroke is highly associated with functional disability. Empirical evidence shows that exercise combined cognitive training may induce neuroplastic changes that modulate cognitive function. However, it is unclear whether hybridized exercise-cognitive training can facilitate cortical activity and physiological outcome measures and further influence on the cognitive function after stroke. This study will investigate the effects of two hybridized exercise-cognitive trainings on brain plasticity, physiological biomarkers and behavioral outcomes in stroke survivors with cognitive decline.

Methods and significance

This study is a single-blind randomized controlled trial. A target sample size of 75 participants is needed to obtain a statistical power of 95% with a significance level of 5%. Stroke survivors with mild cognitive decline will be stratified by Mini-Mental State Examination scores and then randomized 1:1:1 to sequential exercise-cognitive training, dual-task exercise-cognitive training or control groups. All groups will undergo training 60 min/day, 3 days/week, for a total of 12 weeks. The primary outcome is the resting-state functional connectivity and neural activation in the frontal, parietal and occipital lobes in functional magnetic resonance imaging. Secondary outcomes include physiological biomarkers, cognitive functions, physical function, daily functions and quality of life. This study may differentiate the effects of two hybridized trainings on cognitive function and health-related conditions and detect appropriate neurological and physiological indices to predict training effects. This study capitalizes on the groundwork for a non-pharmacological intervention of cognitive decline after stroke.

Impact of Cognitive Remediation Therapy on Neurocognitive Processing in Anorexia Nervosa

BACKGROUND

Anorexia nervosa (AN) is characterized by severe malnutrition as well as inefficiencies in neurocognitive functioning, which are believed to contribute to the maintenance of disordered eating. The aim of this study was to examine the impact of individual cognitive remediation therapy (CRT) on neurocognition in AN.

METHODS

A total of 145 adult women from an eating disorders inpatient program took part in the present study. All participants were given individual CRT in addition to treatment as usual. Neurocognitive processes were assessed at baseline and at the end of treatment using task-based and self-report measures. The task-based measures included the Rey-Osterrieth Complex Figure test and the Brixton test, which were used to assess central coherence and set-shifting. The Detail and Flexibility Questionnaire was used to examine patients self-reported detail focus and cognitive flexibility.

RESULTS

Participants showed significant improvement in task-based measures of neurocognition following CRT. There were no significant changes in self-report measures.

CONCLUSION

These findings suggest that CRT may be an effective intervention targeting inefficiencies in neurocognition in AN. Future studies may benefit from assessing neural changes associated with these improvements and conducting randomized controlled trials to replicate these findings.

Synergistic effects of aerobic exercise and cognitive training on cognition, physiological markers, daily function, and quality of life in stroke survivors with cognitive decline: study protocol for a randomized controlled trial

Background

Aerobic exercise and cognitive training have been effective in improving cognitive functions; however, whether the combination of these two can further enhance cognition and clinical outcomes in stroke survivors with cognitive decline remains unknown. This study aimed to determine the treatment effects of a sequential combination of aerobic exercise and cognitive training on cognitive function and clinical outcomes.

Methods/design

Stroke survivors (n = 75) with cognitive decline will be recruited and randomly assigned to cognitive training, aerobic exercise, and sequential combination of aerobic exercise and cognitive training groups. All participants will receive training for 60 minutes per day, 3 days per week for 12 weeks. The aerobic exercise group will receive stationary bicycle training, the cognitive training group will receive cognitive-based training, and the sequential group will first receive 30 minutes of aerobic exercise, followed by 30 minutes of cognitive training. The outcome measures involve cognitive functions, physiological biomarkers, daily function and quality of life, physical functions, and social participation. Participants will be assessed before and immediately after the interventions, and 6 months after the interventions. Repeated measures of analysis of variance will be used to evaluate the changes in outcome measures at the three assessments.

Discussion

This trial aims to explore the benefits of innovative intervention approaches to improve the cognitive function, physiological markers, daily function, and quality of life in stroke survivors with cognitive decline. The findings will provide evidence to advance post-stroke cognitive rehabilitation.

Trial registration

ClinicalTrials.gov, NCT02550990. Registered on 6 September 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2153-7) contains supplementary material, which is available to authorized users.

Effects of computerized cognitive training on neuroimaging outcomes in older adults: a systematic review

BACKGROUND

Worldwide, the population is aging and the number of individuals diagnosed with dementia is rising rapidly. Currently, there are no effective pharmaceutical cures. Hence, identifying lifestyle approaches that may prevent, delay, or treat cognitive impairment and dementia in older adults is becoming increasingly important. Computerized Cognitive Training (CCT) is a promising strategy to combat cognitive decline. Yet, the underlying mechanisms of the effect of CCT on cognition remain poorly understood. Hence, the primary objective of this systematic review was to examine peer-reviewed literature ascertaining the effect of CCT on both structural and functional neuroimaging measures among older adults to gain insight into the underlying mechanisms by which CCT may benefit cognitive function.

METHODS

In accordance with PRISMA guidelines, we used the following databases: MEDLINE, EMBASE, and CINAHL. Two independent reviewers abstracted data using pre-defined terms. These included: main study characteristics such as the type of training (i.e., single- versus multi-domain), participant demographics (age ≥ 50 years; no psychiatric conditions), and the inclusion of neuroimaging outcomes. The Physiotherapy Evidence Database (PEDro) scale was used to assess quality of all studies included in this systematic review.

RESULTS

Nine studies were included in this systematic review, with four studies including multiple MRI sequences. Results of this systematic review are mixed: CCT was found to increase and decrease both brain structure and function in older adults. In addition, depending on region of interest, both increases and decreases in structure and function were associated with behavioural performance.

CONCLUSIONS

Of all studies included in this systematic review, results from the highest quality studies, which were two randomized controlled trials, demonstrated that multi-domain CCT could lead to increases in hippocampal functional connectivity. Further high quality studies that include an active control, a sample size calculation, and an appropriate training dosage, are needed to confirm these findings and their relation to cognition.

Brain training improves recovery after stroke but waiting list improves equally: A multicenter randomized controlled trial of a computer-based cognitive flexibility training

BACKGROUND

Brain training is currently widely used in an attempt to improve cognitive functioning. Computer-based training can be performed at home and could therefore be an effective add-on to available rehabilitation programs aimed at improving cognitive functioning. Several studies have reported cognitive improvements after computer training, but most lacked proper active and passive control conditions.

OBJECTIVE

Our aim was to investigate whether computer-based cognitive flexibility training improves executive functioning after stroke. We also conducted within-group analyses similar to those used in previous studies, to assess inferences about transfer effects when comparisons to proper control groups are missing.

METHODS

We conducted a randomized controlled, double blind trial. Adults (30-80 years old) who had suffered a stroke within the last 5 years were assigned to either an intervention group (n = 38), active control group (i.e., mock training; n = 35), or waiting list control group (n = 24). The intervention and mock training consisted of 58 half-hour sessions within a 12-week period. Cognitive functioning was assessed using several paper-and-pencil and computerized neuropsychological tasks before the training, immediately after training, and 4 weeks after training completion.

RESULTS AND CONCLUSIONS

Both training groups improved on training tasks, and all groups improved on several transfer tasks (three executive functioning tasks, attention, reasoning, and psychomotor speed). Improvements remained 4 weeks after training completion. However, the amount of improvement in executive and general cognitive functioning in the intervention group was similar to that of both control groups (active control and waiting list). Therefore, this improvement was likely due to training-unspecific effects. Our results stress the importance to include both active and passive control conditions in the study design and analyses. Results from studies without proper control conditions should be interpreted with care.

Increased functional connectivity one week after motor learning and tDCS in stroke patients

Recent studies using resting-state functional magnetic resonance imaging (rs-fMRI) demonstrated that changes in functional connectivity (FC) after stroke correlate with recovery. The aim of this study was to explore whether combining motor learning to dual transcranial direct current stimulation (dual-tDCS, applied over both primary motor cortices (M1)) modulated FC in stroke patients. Twenty-two chronic hemiparetic stroke patients participated in a baseline rs-fMRI session. One week later, dual-tDCS/sham was applied during motor skill learning (intervention session); one week later, the retention session started with the acquisition of a run of rs-fMRI imaging. The intervention+retention sessions were performed once with dual-tDCS and once with sham in a randomized, cross-over, placebo-controlled, double-blind design. A whole-brain independent component analysis based analysis of variance (ANOVA) demonstrated no changes between baseline and sham sessions in the somatomotor network, whereas a FC increase was observed one week after dual-tDCS compared to baseline (qFDR <0.05, t₆₃=4.15). A seed-based analysis confirmed specific stimulation-driven changes within a network of motor and premotor regions in both hemispheres. At baseline and one week after sham, the strongest FC was observed between the M1 and dorsal premotor cortex (PMd) of the undamaged hemisphere. In contrast, one week after dual-tDCS, the strongest FC was found between the M1 and PMd of the damaged hemisphere. Thus, a single session of dual-tDCS combined with motor skill learning increases FC in the somatomotor network of chronic stroke patients for one week.

Cognitive Training in Parkinson's Disease: A Review of Studies from 2000 to 2014

Cognitive deficits are prevalent among patients with Parkinson's disease (PD), in both early and late stages of the disease. These deficits are associated with lower quality of life, loss of independence, and institutionalization. To date, there is no effective pharmacological treatment for the range of cognitive impairments presented in PD. Cognitive training (CT) has been explored as an alternative approach to remediating cognition in PD. In this review we present a detailed summary of 13 studies of CT that have been conducted between 2000 and 2014 and a critical examination of the evidence for the effectiveness and applicability of CT in PD. Although the evidence shows that CT leads to short-term, moderate improvements in some cognitive functions, methodological inconsistencies weaken these results. We discuss several key limitations of the literature to date, propose methods of addressing these questions, and outline the future directions that studies of CT in PD should pursue. Studies need to provide more detail about the cognitive profile of participants, include larger sample sizes, be hypothesis driven, and be clearer about the training interventions and the outcome measures.

Cognitive rehabilitation for memory deficits after stroke

BACKGROUND

Memory problems are a common cognitive complaint following stroke and can potentially affect ability to complete functional activities. Cognitive rehabilitation programmes either attempt to retrain lost or poor memory functions, or teach patients strategies to cope with them.Some studies have reported positive results of cognitive rehabilitation for memory problems, but the results obtained from previous systematic reviews have been less positive and they have reported inconclusive evidence. This is an update of a Cochrane review first published in 2000 and most recently updated in 2007.

OBJECTIVES

To determine whether participants who have received cognitive rehabilitation for memory problems following a stroke have better outcomes than those given no treatment or a placebo control.The outcomes of interest were subjective and objective assessments of memory function, functional ability, mood, and quality of life. We considered the immediate and long-term outcomes of memory rehabilitation.

SEARCH METHODS

We used a comprehensive electronic search strategy to identify controlled studies indexed in the Cochrane Stroke Group Trials Register (last searched 19 May 2016) and in the Cochrane Central Register of Controlled Trials (CENTRAL2016, Issue 5), MEDLINE (2005 to 7 March 2016), EMBASE 2005 to 7 March 2016), CINAHL (2005 to 5 February 2016), AMED (2005 to 7 March 2016), PsycINFO (2005 to 7 March 2016), and nine other databases and registries. Start dates for the electronic databases coincided with the last search for the previous review. We handsearched reference lists of primary studies meeting the inclusion criteria and review articles to identify further eligible studies.

SELECTION CRITERIA

We selected randomised controlled trials in which cognitive rehabilitation for memory problems was compared to a control condition. We included studies where more than 75% of the participants had experienced a stroke, or if separate data were available from those with stroke in mixed aetiology studies. Two review authors independently selected trials for inclusion, which was then confirmed through group discussion.

DATA COLLECTION AND ANALYSIS

We assessed study risk of bias and extracted data. We contacted the investigators of primary studies for further information where required. We conducted data analysis and synthesis in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. We performed a 'best evidence' synthesis based on the risk of bias of the primary studies included. Where there were sufficient numbers of similar outcomes, we calculated and reported standardised mean differences (SMD) using meta-analysis.

MAIN RESULTS

We included 13 trials involving 514 participants. There was a significant effect of treatment on subjective reports of memory in the short term (standard mean difference (SMD) 0.36, 95% confidence interval (CI) 0.08 to 0.64, P = 0.01, moderate quality of evidence), but not the long term (SMD 0.31, 95% CI -0.02 to 0.64, P = 0.06, low quality of evidence). The SMD for the subjective reports of memory had small to moderate effect sizes.The results do not show any significant effect of memory rehabilitation on performance in objective memory tests, mood, functional abilities, or quality of life.No information was available on adverse events.

AUTHORS' CONCLUSIONS

Participants who received cognitive rehabilitation for memory problems following a stroke reported benefits from the intervention on subjective measures of memory in the short term (i.e. the first assessment point after the intervention, which was a minimum of four weeks). This effect was not, however, observed in the longer term (i.e. the second assessment point after the intervention, which was a minimum of three months). There was, therefore, limited evidence to support or refute the effectiveness of memory rehabilitation. The evidence was limited due to the poor quality of reporting in many studies, lack of consistency in the choice of outcome measures, and small sample sizes. There is a need for more robust, well-designed, adequately powered, and better-reported trials of memory rehabilitation using common standardised outcome measures.

Computer-Based Cognitive Training for Executive Functions after Stroke: A Systematic Review

Background: Stroke commonly results in cognitive impairments in working memory, attention, and executive function, which may be restored with appropriate training programs. Our aim was to systematically review the evidence for computer-based cognitive training of executive dysfunctions.

Methods: Studies were included if they concerned adults who had suffered stroke or other types of acquired brain injury, if the intervention was computer training of executive functions, and if the outcome was related to executive functioning. We searched in MEDLINE, PsycINFO, Web of Science, and The Cochrane Library. Study quality was evaluated based on the CONSORT Statement. Treatment effect was evaluated based on differences compared to pre-treatment and/or to a control group.

Results: Twenty studies were included. Two were randomized controlled trials that used an active control group. The other studies included multiple baselines, a passive control group, or were uncontrolled. Improvements were observed in tasks similar to the training (near transfer) and in tasks dissimilar to the training (far transfer). However, these effects were not larger in trained than in active control groups. Two studies evaluated neural effects and found changes in both functional and structural connectivity. Most studies suffered from methodological limitations (e.g., lack of an active control group and no adjustment for multiple testing) hampering differentiation of training effects from spontaneous recovery, retest effects, and placebo effects.

Conclusions: The positive findings of most studies, including neural changes, warrant continuation of research in this field, but only if its methodological limitations are addressed.

Specific locations within the white matter and cortex are involved in the cognitive impairments associated with periventricular white matter lesions (PWMLs)

The aim of this study was to test the hypothesis that both white matter disruption and the corresponding cortical dysfunction are involved in the cognitive impairments associated with periventricular white matter lesions (PWMLs). Twenty-two PWMLs subjects were divided into cognitively impaired (PWMLs-CI) and normal (PWMLs-CN) groups. Twelve subjects with normal magnetic resonance imaging (MRI) and cognition were recruited as controls. After cognitive evaluation, diffusion tension image (DTI) and resting-state functional MRI (rfMRI) scans, the fractional anisotropy (FA) values of DTI and the fractional amplitude of low-frequency fluctuation (fALFF) values of rfMRI were measured. Finally, correlations between the cognitive scores and MRI values were analyzed in PWMLs subjects. Our results demonstrated that compared with the other groups, the PWMLs-CI group demonstrated significantly decreased scores in Trail-Making Test (TMT), Symbol Digit Modalities Test (SDMT) and Logical Memory Test (LMT). Compared with the PWMLs-CN group, the PWMLs-CI group displayed decreased FA values in the right splenium of the corpus callosum and right posterior cingulum bundle; lower fALFF values in the left frontal middle gyrus, left precentral gyrus, right angular gyrus and right precuneus; and higher fALFF values in the right mid cingulum cortex, right hippocampus amygdala, right cerebellar hemisphere and left vermis. Meanwhile, the cognitive assessment scores were significantly correlated with the FA or fALFF values in some of the above-mentioned white matter or cortical regions. Conclusively, our results indicate that specific regions of WMLs and cortical dysfunction are involved in the cognitive impairments associated with PWMLs.

Effect of integrated cognitive therapy on hippocampal functional connectivity patterns in stroke patients with cognitive dysfunction: a resting-state FMRI study

Objective. This study aimed to identify abnormal hippocampal functional connectivity (FC) following ischemic stroke using resting-state fMRI. We also explored whether abnormal hippocampal FC could be modulated by integrated cognitive therapy and tested whether these alterations were associated with cognitive performance. Methods. 18 right-handed cognitively impaired ischemic stroke patients and 18 healty control (HC) subjects were included in this study. Stroke subjects were scanned at baseline and after integrated cognitive therapy, while HCs were only scanned at baseline, to identify regions that show significant correlations with the seed region. Behavioral and cognitive assessments were obtained before each scan. Results. During the resting state, we found abnormal hippocampal FC associated with temporal regions, insular cortex, cerebellum, and prefrontal cortex in stroke patients compared to HCs. After integrated cognitive therapy, however, the stroke group showed increased hippocampal FC mainly located in the prefrontal gyrus and the default mode network (DMN). Altered hippocampal FC was associated with cognitive improvement. Conclusion. Resting-state fMRI may provide novel insight into the study of functional networks in the brain after stroke. Furthermore, altered hippocampal FC may be a compensatory mechanism for cognitive recovery after ischemic stroke.