Adaptive working memory strategy training in early Alzheimer's disease: randomised controlled trial

Comparison of Cognitive Intervention Strategies for Individuals With Alzheimer's Disease: A Systematic Review and Network Meta-analysis

Accumulating evidence has shown the effectiveness of cognitive interventions, which can be divided into cognitive training (CT), cognitive stimulation (CS), cognitive rehabilitation (CR), and combined interventions (i.e., cognitive interventions combined with other non-pharmacological interventions such as physical exercise), in individuals with Alzheimer's disease (AD). However, the effectiveness of cognitive interventions varies greatly among studies and more comprehensive studies are required. We aimed to evaluate whether the current evidence shows that cognitive interventions are effective at improving cognition, neuropsychiatric symptoms, depression, quality of life, and basic activities of daily living among individuals with possible or probable AD. Randomized controlled trials of all types of cognitive intervention were identified for inclusion in pairwise and network meta-analyses. There was a moderate and statistically significant post-intervention improvement in global cognition among individuals with AD for all types of cognitive intervention compared to control interventions (39 studies, g = 0.43, 95% CI: 0.28 to 0.58, p < 0.01; Q = 102.27, df = 38, p < 0.01; I2 = 61.97%, τ2 = 0.13). Regarding the specific types of cognitive intervention, combined interventions had the highest surface under the cumulative ranking curve (SUCRA) value (90.7%), followed by CT (67.8%), CS (53.4%), and lastly CR (28.9%). Significant effects of cognitive interventions were also found for working memory, verbal memory, verbal fluency, confrontation naming, attention, neuropsychiatric symptoms, basic activities of daily living, and quality of life.

Intrinsic functional brain connectivity changes following aerobic exercise, computerized cognitive training, and their combination in physically inactive healthy late-middle-aged adults: the Projecte Moviment

Lifestyle interventions have positive neuroprotective effects in aging. However, there are still open questions about how changes in resting-state functional connectivity (rsFC) contribute to cognitive improvements. The Projecte Moviment is a 12-week randomized controlled trial of a multimodal data acquisition protocol that investigated the effects of aerobic exercise (AE), computerized cognitive training (CCT), and their combination (COMB). An initial list of 109 participants was recruited from which a total of 82 participants (62% female; age = 58.38 ± 5.47) finished the intervention with a level of adherence > 80%. Only in the COMB group, we revealed an extended network of 33 connections that involved an increased and decreased rsFC within and between the aDMN/pDMN and a reduced rsFC between the bilateral supplementary motor areas and the right thalamus. No global and especially local rsFC changes due to any intervention mediated the cognitive benefits detected in the AE and COMB groups. Projecte Moviment provides evidence of the clinical relevance of lifestyle interventions and the potential benefits when combining them.

The cognitive profile of middle-aged and older adults with high vs. low autistic traits

Cognitive differences in memory, information processing speed (IPS), and executive functions (EF), are common in autistic and high autistic trait populations. Despite memory, IPS and EF being sensitive to age-related change, little is known about the cognitive profile of older adults with high autistic traits. This study explores cross-sectional memory, IPS and EF task performance in a large sample of older adults in the online PROTECT cohort (n = 22,285, aged 50-80 years), grouped by high vs. low autistic traits. Approximately 1% of PROTECT participants (n = 325) endorsed high autistic traits [henceforth Autism Spectrum Trait (AST) group]. Differences between AST and age-, gender-, and education-matched comparison older adults (COA; n = 11,744) were explored on memory, IPS and EF tasks and questionnaires administered online. AST had lower performance than COA on tasks measuring memory, working memory, sustained attention, and information processing. No group differences were observed in simple attention or verbal reasoning. A similar pattern of results was observed when controlling for age, and current depression and anxiety symptoms. In addition, AST self-reported more cognitive decline than COA, but this difference was not significant when controlling for current depression symptoms, or when using informant-report. These findings suggest that autistic traits are associated with cognitive function in middle-aged and later life. Older adults with high autistic traits experienced more performance difficulties in a range of memory, IPS and EF tasks compared with the low autistic traits comparison group. Further longitudinal work is needed to examine age-related change in both older autistic and autistic trait populations.

Non-drug Therapies for Alzheimer's Disease: A Review

Alzheimer's disease (AD) is a debilitating disease leading to great social and economic burdens worldwide. During the past decades, increasing understanding of this disease enables dynamic trials for disease interventions. Unfortunately, at present, AD still remains uncurable, and therefore, developing intervention strategies for improving symptoms and slowing down the disease process becomes a practical focus in parallel with searching for a disease-modifying medication. The aim of this review is to summarize the outcomes of AD clinical trials of non-drug therapies published in the past decade, including cognitive-oriented interventions, physical exercise interventions, brain stimulation, as well as nutrition supplementations, to find out the most effective interventions in the category by looking through the primary and secondary outcomes. The outcomes of the trials could be varied with the interventional approaches, the tested cohorts, the settings of observing outcomes, and the duration of follow-ups, which are all discussed in this review. Hence, we hope to provide crucial information for application of these interventions in real-world settings and assist with optimization of clinical trial designs in this area.

Unifying framework for cognitive training interventions in brain aging

Cognitive training is a promising tool for slowing or preventing cognitive decline in older adults at-risk for dementia. Its success, however, has been limited by a lack of evidence showing that it reliably causes broad training effects: improvements in cognition across a range of domains that lead to real-world benefits. Here, we propose a framework for enhancing the effect of cognitive training interventions in brain aging. The focus is on (A) developing cognitive training task paradigms that are informed by population-level cognitive characteristics and pathophysiology, and (B) personalizing how these sets are presented to participants during training via feedback loops that aim to optimize "mismatch" between participant capacity and training demands using both adaptation and random variability. In this way, cognitive training can better alter whole-brain topology in a manner that supports broad training effects in the context of brain aging.

Altered Functional Network Connectivity of Precuneus and Executive Control Networks in Type 2 Diabetes Mellitus Without Cognitive Impairment

In epidemiological studies, type 2 diabetes mellitus (T2DM) has been associated with cognitive impairment and dementia, but studies about functional network connectivity in T2DM without cognitive impairment are limited. This study aimed to explore network connectivity alterations that may help enhance our understanding of damage-associated processes in T2DM. MRI data were analyzed from 82 patients with T2DM and 66 normal controls. Clinical, biochemical, and neuropsychological assessments were conducted in parallel with resting-state functional magnetic resonance imaging, and the cognitive status of the patients was assessed using the Montreal Cognitive Assessment-B (MoCA-B) score. Independent component analysis revealed a positive correlation between the salience network and the visual network and a negative connection between the left executive control network and the default mode network in patients with T2DM. The differences in dynamic brain network connectivity were observed in the precuneus, visual, and executive control networks. Internal network connectivity was primarily affected in the thalamus, inferior parietal lobe, and left precuneus. Hemoglobin A1c level, body mass index, MoCA-B score, and grooved pegboard (R) assessments indicated significant differences between the two groups (p < 0.05). Our findings show that key changes in functional connectivity in diabetes occur in the precuneus and executive control networks that evolve before patients develop cognitive deficits. In addition, the current study provides useful information about the role of the thalamus, inferior parietal lobe, and precuneus, which might be potential biomarkers for predicting the clinical progression, assessing the cognitive function, and further understanding the neuropathology of T2DM.

Neuronal efficiency following n-back training task is accompanied by a higher cerebral glucose metabolism

Recent functional magnetic resonance imaging (fMRI) studies revealed lower neural activation during processing of an n-back task following working memory training, indicating a training-related increase in neural efficiency. In the present study, we asked if the training induced regional neural activation is accompanied by changes in glucose consumption. An active control and an experimental group of healthy middle-aged volunteers conducted 32 sessions of visual and verbal n-back trainings over 8 weeks. We analyzed data of 52 subjects (25 experimental and 27 control group) for practice effects underlying verbal working memory task and 50 subjects (24 experimental and 26 control group) for practice effects underlying visual WM task. The samples of these two tasks were nearly identical (data of 47 subjects were available for both verbal and visual tasks). Both groups completed neuroimaging sessions at a hybrid PET/MR system before and after training. Each session included criterion task fMRI and resting state positron emission tomography with FDG (FDG-PET). As reported previously, lower neural activation following n-back training was found in regions of the fronto-parieto-cerebellar circuitry during a verbal n-back task. Notably, these changes co-occurred spatially with a higher relative FDG-uptake. Decreased neural activation within regions of the fronto-parietal network during visual n-back task did not show co-occurring changes in relative FDG-uptake. There was no direct association between neuroimaging and behavioral measures, which could be due to the inter-subjects' variability in reaching capacity limits. Our findings provide new details for working memory training induced neural efficiency on a molecular level by integrating FDG-PET and fMRI measures.

Associations of subjective cognitive and memory decline with depression, anxiety, and two-year change in objectively-assessed global cognition and memory

Research studies exploring the association of cognitive complaints with objectively assessed cognitive decline report inconsistent results. However, many of these have methodological limitations. We investigated whether 1) more severe subjective cognitive decline (SCD) and subjective memory decline (SMD) predict change in objectively assessed global cognition, remote memory, recent memory, learning; 2) the predictive value of more severe SMD over change in objectively assessed remote memory, recent memory, and learning is stronger for individuals that report an SMD that started within the past five years than for those that report an SMD that started five or more years previously and/or stronger for those that experienced SMD within the past two years than for those who had not; and 3) greater depression and anxiety are associated with more severe SCD and SMD. We used two-year longitudinal data from the CFAS-Wales study (N = 1,531; mean (SD) age = 73.0 (6.0) years). We fitted linear regression models. More severe SCD and SMD did not predict change in objectively assessed global cognition, remote memory, and recent memory but predicted lower scores in learning. The prediction of SMD over change in learning was not stronger when individuals reported an SMD that started within the past five years compared to when they reported an SMD that started five or more years previously nor when individuals reported an SMD that started within the past two years than those who did not. Greater depression and anxiety were associated with more severe SCD and SMD. More severe SMD may be useful for predicting lower learning ability and for identifying individuals experiencing depression and anxiety.

The Effect of Cognitive Intervention on Cognitive Function in Older Adults With Alzheimer's Disease: A Systematic Review and Meta-Analysis

Cognitive intervention includes cognitive stimulation, cognitive training, and cognitive rehabilitation. This systematic review was performed to re-assess the efficacy of cognitive intervention for the patients with Alzheimer's disease (AD). Twenty studies (2012 participants) were eventually included. For global cognitive function, the combined mean difference (MD) in eight studies was 1.67 (95% Confidence Interval: 0.45, 2.89, p = 0.007; Q = 33.28, df = 8, p < 0.0001, τ² = 2.17, I² = 76%) for the short term. The pooled standardized mean difference (SMD) of six RCTs was 1.61 (95% Confidence Interval: 0.65, 2.56, p = 0.0009; Q = 127.66, df = 6, p < 0.00001, τ² = 1.56, I² = 95%) for the medium term. The pooled SMD of seven studies was 0.79 (95% Confidence Interval: 0.33, 1.25, p = 0.0008; Q = 35.10, df = 7, p < 0.0001, τ² = 0.33, I² = 80%) for the long term. For depression, the pooled SMD of two trials was -0.48 (95% Confidence Interval: -0.71, -0.24; p < 0.0001, I² = 4%) for the short term. Cognitive training may show obvious improvements in global cognitive function whether after short, medium, or long-term interventions and in depression after short term intervention. However, the positive effect of the intervention on general cognitive function or depression did not seem to persist after intervention ended. There is still a lack of reliable and consistent conclusions relevant to the effect of cognitive stimulation and cognitive rehabilitation on observed outcomes, cognitive training for memory or other non-cognitive outcomes. PROSPERO registration number: CRD42019121768.

The Cognition and Flow Study: A Feasibility Randomized Controlled Trial of the Effects of Cognitive Training on Cerebral Blood Flow

BACKGROUND

Cognitive training (CT) has demonstrated benefits for healthy older adults (HG) and mild cognitive impairment (MCI), but the effects on vascular function are unknown.

OBJECTIVE

This is a feasibility trial investigating the effects of CT on cerebral blood flow velocity (CBFv).

METHODS

Twenty HG, 24 with Alzheimer's disease (AD), and 12 with MCI were randomized to 12 weeks of multi-domain CT or control. Outcomes included: cognition (Addenbrooke's Cognitive Examination III), mood, quality of life (QoL), physical, and neurovascular function (transcranial Doppler ultrasonography measured task activation of CBFv responses). Data are presented as mean difference (MD) and 95% confidence interval (CI).

RESULTS

47 participants completed the trial. There were three dropouts from the training arm in the AD group, and one in the HG group. The intervention was acceptable and feasible to the majority of participants with a high completion rate (89%). The dropout rate was higher among participants with dementia. Few changes were identified on secondary analyses, but QoL was significantly improved in HG post-training (MD: 4.83 [95% CI: 1.13, 8.54]). CBFv response rate was not significantly different in HG (MD: 1.84 [95% CI: -4.81, 1.12]), but a significant increase was seen in the patient group (MD: 1.79 [95% CI: 0.005, 3.58]), requiring sample sizes of 56 and 84 participants respectively for a fully-powered trial.

CONCLUSION

A 12-week CT program was acceptable and feasible in HG, AD, and MCI. CT may be associated with alterations in vascular physiology which require further investigation in an appropriately powered randomized controlled trial.

Economization of cerebral activation under training: The inverse U- shaped function revisited

As already observed as early as 1967 by Ingvar and Risberg in their pioneering work, effects of practice of working memory on cerebral functions have been confirmed repeatedly in a number of neuroimaging studies using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). Accordingly, initial performance gains are typically accompanied by increased cerebral activation, while consolidation of such performance gains goes along with a subsequent decrease in activation resembling an inverse U-shaped function. This observed pattern can be interpreted as an economization of cerebral functioning as tasks are being accomplished with relatively lower effort and may also apply to other cognitive domains. However, the economization of cerebral activation under training may depend on task difficulty and training characteristics on the one hand and individual factors, including age, intelligence, cognitive reserve, education, physical and mental health on the other. These findings bear important implications for the design of neuroimaging studies and stimulation protocols, in which similar tasks are routinely repeated.

International relevance of two measures of awareness of age-related change (AARC)

BACKGROUND

A questionnaire assessing awareness of positive and negative age-related changes (AARC gains and losses) was developed in the US and Germany. We validated the short form of the measure (AARC-10 SF) and the cognitive functioning subscale from the 50-item version of the AARC (AARC-50) questionnaire in the UK population aged 50 and over.

METHODS

Data from 9410 participants (Mean (SD) age = 65.9 (7.1)) in the PROTECT cohort were used to explore and confirm the psychometric properties of the AARC measures including: validity of the factor structure; reliability; measurement invariance across men and women, individuals with and without a university degree, and in middle age, early old age, and advanced old age; and convergent validity with measures of self-perception of aging and mental, physical, and cognitive health. We explored the relationship between demographic variables (age, sex, marital status, employment, and university education) and AARC.

RESULTS

We confirmed the two-factor structure (gains and losses) of the AARC-10 SF and the AARC-50 cognitive functioning subscale. Both scales showed good reliability and good convergent validity for AARC losses, but weak convergent validity for AARC gains. For both scales metric invariance was held for the two subgroups defined by education level and age. For the AARC-50 subscale, but not for the AARC-10 SF, strong invariance was also held for the two subgroups defined by sex. Age, sex, marital status, employment, and university education predicted AARC gains and losses.

CONCLUSIONS

The AARC-10 SF and AARC-50 cognitive functioning subscale identify UK individuals who perceive age-related changes in their mental, physical, and cognitive health.

Dissociable effects of attention vs working memory training on cognitive performance and everyday functioning following fronto-parietal strokes

Difficulties with attention are common following stroke, particularly in patients with frontal and parietal damage, and are associated with poor outcome. Home-based online cognitive training may have the potential to provide an efficient and effective way to improve attentional functions in such patients. Little work has been carried out to assess the efficacy of this approach in stroke patients, and the lack of studies with active control conditions and rigorous evaluations of cognitive functioning pre and post-training means understanding is limited as to whether and how such interventions may be effective. Here, in a feasibility pilot study, we compare the effects of 20 days of cognitive training using either novel Selective Attention Training (SAT) or commercial Working Memory Training (WMT) programme, versus a waitlist control on a range of attentional and working memory tasks. We demonstrate separable effects of each training condition, with SAT leading to improvements in spatial and non-spatial aspects of attention and WMT leading to improvements on closely related working memory tasks. In addition, both training groups reported improvements in everyday functioning, which were associated with improvements in attention, suggesting that improving attention may be of particular importance in maximising functional improvements in this patient group.

The Effects of Cognitive Training on Brain Network Activity and Connectivity in Aging and Neurodegenerative Diseases: a Systematic Review

Cognitive training (CT) is an increasingly popular, non-pharmacological intervention for improving cognitive functioning in neurodegenerative diseases and healthy aging. Although meta-analyses support the efficacy of CT in improving cognitive functioning, the neural mechanisms underlying the effects of CT are still unclear. We performed a systematic review of literature in the PubMed, Embase and PsycINFO databases on controlled CT trials (N > 20) in aging and neurodegenerative diseases with pre- and post-training functional MRI outcomes up to November 23rd 2018 (PROSPERO registration number CRD42019103662). Twenty articles were eligible for our systematic review. We distinguished between multi-domain and single-domain CT. CT induced both increases and decreases in task-related functional activation, possibly indicative of an inverted U-shaped curve association between regional brain activity and task performance. Functional connectivity within ‘cognitive’ brain networks was consistently reported to increase after CT while a minority of studies additionally reported increased segregation of frontoparietal and default mode brain networks. Although we acknowledge the large heterogeneity in type of CT, imaging methodology, in-scanner task paradigm and analysis methods between studies, we propose a working model of the effects of CT on brain activity and connectivity in the context of current knowledge on compensatory mechanisms that are associated with aging and neurodegenerative diseases.

Neuropsychological outcome of cognitive training in mild to moderate dementia: A randomized controlled trial

Effectiveness of a 12-week cognitive training (CT) programme for community-dwelling patients with dementia was evaluated on various cognitive functions (attention, memory, executive functions and reasoning) and psychological well-being (PWB). A single-blind randomized controlled trial was conducted in adult day care centres in Helsinki, Finland. Participants (N = 147) were older individuals with mild to moderate dementia living at home and attending day care (mean age 83 years, 72% female, 63% at mild stage of dementia). The intervention group (n = 76) received systematic CT for 45 min twice a week while the control group (n = 71) attended day care as usual. The cognitive and psychological outcomes were measured at baseline, and followed up at 3 and 9 months. No differences between the two groups in changes of any of the cognitive functions, or PWB over time were found. We observed a positive trend at 3 months in the change for PWB favouring the intervention group, but no significant interaction effect was found (p = .079; d = -0.31). Thus, systematic CT appears to have no effect on neuropsychological outcomes of cognitive functioning and PWB in older adults who already have dementia.

Evaluation of Cognitive Function in Relation to Progression of Parkinson Disease

OBJECTIVE

Cognitive impairments are among the nonmotor symptoms in patients with Parkinson disease. Understanding the cognitive impairments in patients with Parkinson disease may be critical for developing effective rehabilitation interventions. The aims of this study were to assess cognitive function in patients with Parkinson disease using the Wechsler Adult Intelligence Scale Third Edition, and the Wechsler Memory Scale Revised and to investigate how cognitive impairments relate to progression of disease in patients with Parkinson disease according to the Hoehn and Yahr stages.

DESIGN

Seventy-eight patients with Parkinson disease participated in the present study. Our study consisted of patients in the following Hoehn and Yahr groups: 1 (no disability, n = 11), 2 (mild, n = 34), 3 (moderate, n = 26), and 4 and 5 (severe, n = 7). Cognitive function was assessed using the Wechsler Adult Intelligence Scale Third Edition, and the Wechsler Memory Scale Revised.

RESULTS

The verbal memory was significantly higher in group 1 (106.4 ± 12.0) than in the other groups (2: 90.5 ± 14.0, 3: 89.9 ± 16.9, 4 and 5: 89.6 ± 11.4). Visual memory and delayed recall were similar to the results seen with verbal memory; however, the differences between groups were not statistically significant. The full-scale IQ was not significantly different (1: 107.3 ± 8.1, 2: 96.9 ± 18.2, 3: 96.7 ± 14.8, 4 and 5: 91.7 ± 9.5).

CONCLUSIONS

These results suggest that a comprehensive assessment focused on memory impairments is important for applying the appropriate interventions in patients with early-stage Parkinson disease.

Age differences in the fronto-striato-parietal network underlying serial ordering

Maintaining the ability to arrange thoughts and actions in an appropriate serial order is crucial for complex behavior. We aimed to investigate age differences in the fronto-striato-parietal network underlying serial ordering using functional magnetic resonance imaging. We exposed 25 young and 27 older healthy adults to a digit ordering task, where they had to reorder and recall sequential digits or simply to recall them. We detected a network comprising of the lateral and medial prefrontal, posterior parietal, and striatal regions. In young adults, the prefrontal and parietal regions were more activated and more strongly connected with the supplementary motor area for "reorder & recall" than "pure recall" trials (psychophysiological interaction, PPI). In older adults, the prefrontal and parietal activations were elevated, but the PPI was attenuated. Individual adults who had a stronger PPI performed more accurately in "reorder & recall" trials. The decreased PPI appeared to be compensated by increased physiological correlations between the prefrontal/parietal cortex and the striatum, and by that between the striatum and the supplementary motor area.

Randomized controlled trial of TDCS on cognition in 201 seniors with mild neurocognitive disorder

OBJECTIVE

To examine the efficacy and safety of combined transcranial direct current stimulation (tDCS) and working memory training (WMT) in enhancing the cognitive functions for individuals with mild neurocognitive disorder due to AD (NCD-AD).

METHODS

In this double-blind, sham-controlled randomized clinical trial (RCT), 201 patients with NCD-AD were randomly assigned for a 4-week intervention of either a combination of tDCS and WMT, sham tDCS and WMT, or tDCS and control cognitive training (CCT). Global cognition and domain-specific cognitive function were assessed before and after the intervention with Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog), category verbal fluency test, logical memory, digit, and visual span tests.

RESULTS

Study participants did not show intervention group differences in baseline demographics, or cognitive characteristics (ANOVA). Cognitive enhancement was found across three groups after 4 weeks intervention. Combined tDCS-WMT group showed significantly greater improvement compared with single-modality groups in delayed recall (P = 0.043, η²  = 0.036) and working memory capacity (P = 0.04, η²  = 0.038) at 4th week, and logical memory at 12th week (P = 0.042, η²  = 0.037). Adverse events, including skin lesions (2.2%), were similar between groups.

INTERPRETATION

tDCS or WMT could be a safe, feasible, and effective intervention for individuals with NCD-AD. A combination of tDCS and WMT presents greater cognitive enhancement, which may highlight the potential synergistic effects of combined modality intervention on cognition.

Psychosocial Interventions for Community-Dwelling People Following Diagnosis of Mild to Moderate Dementia: Findings of a Systematic Scoping Review

National policies and evidence reviews recommend psychosocial interventions (PIs) as an essential support, particularly in the period following dementia diagnosis. However, availability and uptake of these interventions are comparatively low. One of the reasons for this is that clinicians lack information about what might be provided and the potential benefits of different interventions. This article identifies and describes PIs for community-dwelling people following diagnosis of mild to moderate dementia and presents the available evidence to inform practice decisions. A systematic scoping review was employed to map the evidence relating to PIs for this group. This identified 63 relevant studies, testing 69 interventions, which could be grouped into 6 intervention categories: 20 cognition-oriented, 11 behavior-oriented, 11 stimulation-oriented, 13 emotion-oriented, 5 social-oriented, and 9 multimodal. There were three targets for outcome measurement of these PIs: the person with dementia, the family caregiver, and the person-caregiver dyad. Over 154 outcome measures were identified in the studies, with outcomes measured across 11 main domains. The lack of a classification framework for PIs means it is difficult to create a meaningful synthesis of the breadth of relevant evidence to guide clinical practice. Possible dimensions of a classification framework are proposed to begin to address this gap.

Neurocircuitry of acupuncture effect on cognitive improvement in patients with mild cognitive impairment using magnetic resonance imaging: a study protocol for a randomized controlled trial

Background

Mild cognitive impairment (MCI) is defined as a decline in cognitive state with preservation of activities of daily living. Medications such as donepezil and rivastigmine have been commonly prescribed for MCI, but their use is controversial. Acupuncture has been widely used in Korea and has been shown to improve cognitive function. The aim of this study is to evaluate the efficacy of acupuncture for MCI and investigate the effect of acupuncture on structural and functional brain changes in patients with MCI.

Methods

This study is a randomized, assessor-blinded, sham-controlled trial. Fifty participants with MCI will be randomly assigned to the acupuncture group (n = 25) or sham acupuncture group (n = 25). The acupuncture group will receive acupuncture treatment at nine acupuncture points (GV20, EX-HN1, bilateral LI4, and ST36) twice a week for 12 weeks. The sham acupuncture group will receive sham acupuncture treatment at the same points with non-penetrating sham needles. Both groups will be restricted from all other treatments for the improvement of cognitive function. The primary outcome measure is the Digit Span Test (DST). The secondary outcome measures are the Digit Symbol Substitution Test (DSST), Korean version of Montreal Cognitive Assessment (MoCA-K), Seoul Neuropsychological Screening Battery-II (SNSB-II), Beck Depression Inventory-II (BDI-II), State-Trait Anxiety Inventory (STAI), working memory (WM) task performance score, and structural/functional brain changes. Outcomes will be assessed at screening, baseline, 4 and 8 weeks, and after the end of treatment. We will also observe adverse events. In the statistical analysis, a full analysis set and per-protocol analysis will be performed.

Discussion

This randomized clinical trial aims to examine the efficacy of acupuncture treatment for MCI. Neuropsychological tests, psychological inventories for measuring depression and anxiety, and magnetic resonance imaging will be performed to investigate the underlying neurological mechanisms and the association between cognition, emotion, and brain networks following acupuncture treatment. The results of the trial will provide evidence supporting the efficacy of acupuncture and also add to the neurobiological understanding of acupuncture treatment for MCI.

Trial registration

Clinical Research Information Service, KCT0002896. Registered on 25 May 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3446-9) contains supplementary material, which is available to authorized users.

[Aging and verbal memory -an experimental study using structured and non-structured word lists]

AIM

Typical neuropsychological methods for measuring the verbal memory function include the Rey Auditory Verbal Learning Test (AVLT) and the California Verbal Learning Test (CVLT). The stimulus words of the CVLT are structured according to their semantic categories, and many researchers have claimed that the CVLT can also evaluate subjects' memory strategy. However, the stimulus words of these tests do not have equal difficulty, which is necessary when comparing their performances directly, and there are no standard word lists for them in Japanese. In this study, we developed two word lists with the same number and difficulty of stimulus words in order to examine the effects of aging on the comprehension of structured word lists.

METHODS

A non-structured (NS) verbal memory test to represent the AVLT and a structured (S) test to represent the CVLT were developed. The subjects were 40 healthy young adults (18-25 years of age) and 40 healthy elderly individuals (65-80 years of age).

RESULTS

The results revealed that the elderly group correctly recalled significantly fewer words than the young group. The elderly group demonstrated a significantly higher rate of word loss due to interference. The number of correctly recalled words in the elderly group was significantly more for the S test than for the NS test, which was not the case in the young group.

CONCLUSIONS

Since elderly people have a poorer verbal memory than younger people, they gain more benefit from the S test, in which the word list is structured and subjects may be able to use memory strategies more easily. This is the first study in Japan to present standardized word lists for list-learning tasks and their normative data in different age groups.

Cognitive training for people with mild to moderate dementia

BACKGROUND

Cognitive impairment, a defining feature of dementia, plays an important role in the compromised functional independence that characterises the condition. Cognitive training (CT) is an approach that uses guided practice on structured tasks with the direct aim of improving or maintaining cognitive abilities.

OBJECTIVES

• To assess effects of CT on cognitive and non-cognitive outcomes for people with mild to moderate dementia and their caregivers.• To compare effects of CT with those of other non-pharmacological interventions, including cognitive stimulation or rehabilitation, for people with mild to moderate dementia and their caregivers.• To identify and explore factors related to intervention and trial design that may be associated with the efficacy of CT for people with mild to moderate dementia and their caregivers.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group Specialised Register, on 5 July 2018. ALOIS contains records of clinical trials identified through monthly searches of several major healthcare databases and numerous trial registries and grey literature sources. In addition to this, we searched MEDLINE, Embase, PsycINFO, CINAHL, LILACS, Web of Science Core Collection, ClinicalTrials.gov, and the World Health Organization's trials portal, ICTRP, to ensure that searches were comprehensive and up-to-date.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that described interventions for people with mild to moderate dementia and compared CT versus a control or alternative intervention.

DATA COLLECTION AND ANALYSIS

We extracted relevant data from published manuscripts and through contact with trial authors if required. We assessed risk of bias using the Cochrane 'Risk of bias' tool. We divided comparison conditions into active or passive control conditions and alternative treatments. We used a large number of measures and data to evaluate 19 outcomes at end of treatment, as well as 16 outcomes at follow-up in the medium term; we pooled this information in meta-analyses. We calculated pooled estimates of treatment effect using a random-effects model, and we estimated statistical heterogeneity using a standard Chi² statistic. We graded the evidence using GradePro.

MAIN RESULTS

The 33 included trials were published between 1988 and 2018 and were conducted in 12 countries; most were unregistered, parallel-group, single-site RCTs, with samples ranging from 12 to 653 participants. Interventions were between two and 104 weeks long. We classified most experimental interventions as 'straight CT', but we classified some as 'augmented CT', and about two-thirds as multi-domain interventions. Researchers investigated 18 passive and 13 active control conditions, along with 15 alternative treatment conditions, including occupational therapy, mindfulness, reminiscence therapy, and others.The methodological quality of studies varied, but we rated nearly all studies as having high or unclear risk of selection bias due to lack of allocation concealment, and high or unclear risk of performance bias due to lack of blinding of participants and personnel.We used data from 32 studies in the meta-analysis of at least one outcome. Relative to a control condition, we found moderate-quality evidence showing a small to moderate effect of CT on our first primary outcome, composite measure of global cognition at end of treatment (standardised mean difference (SMD) 0.42, 95% confidence interval (CI) 0.23 to 0.62), and high-quality evidence showing a moderate effect on the secondary outcome of verbal semantic fluency (SMD 0.52, 95% CI 0.23 to 0.81) at end of treatment, with these gains retained in the medium term (3 to 12 months post treatment). In relation to many other outcomes, including our second primary outcome of clinical disease severity in the medium term, the quality of evidence was very low, so we were unable to determine whether CT was associated with any meaningful gains.When compared with an alternative treatment, we found that CT may have little to no effect on our first primary outcome of global cognition at end of treatment (SMD 0.21, 95% CI -0.23 to 0.64), but the quality of evidence was low. No evidence was available to assess our second primary outcome of clinical disease severity in the medium term. We found moderate-quality evidence showing that CT was associated with improved mood of the caregiver at end of treatment, but this was based on a single trial. The quality of evidence in relation to many other outcomes at end of treatment and in the medium term was too low for us to determine whether CT was associated with any gains, but we are moderately confident that CT did not lead to any gains in mood, behavioural and psychological symptoms, or capacity to perform activities of daily living.

AUTHORS' CONCLUSIONS

Relative to a control intervention, but not to a variety of alternative treatments, CT is probably associated with small to moderate positive effects on global cognition and verbal semantic fluency at end of treatment, and these benefits appear to be maintained in the medium term. Our certainty in relation to many of these findings is low or very low. Future studies should take stronger measures to mitigate well-established risks of bias, and should provide long-term follow-up to improve our understanding of the extent to which observed gains are retained. Future trials should also focus on direct comparison of CT versus alternative treatments rather than passive or active control conditions.

Dynamic network coding of working-memory domains and working-memory processes

The classic mapping of distinct aspects of working memory (WM) to mutually exclusive brain areas is at odds with the distributed processing mechanisms proposed by contemporary network science theory. Here, we use machine-learning to determine how aspects of WM are dynamically coded in the human brain. Using cross-validation across independent fMRI studies, we demonstrate that stimulus domains (spatial, number and fractal) and WM processes (encode, maintain, probe) are classifiable with high accuracy from the patterns of network activity and connectivity that they evoke. This is the case even when focusing on 'multiple demands' brain regions, which are active across all WM conditions. Contrary to early neuropsychological perspectives, these aspects of WM do not map exclusively to brain areas or processing streams; however, the mappings from that literature form salient features within the corresponding multivariate connectivity patterns. Furthermore, connectivity patterns provide the most precise basis for classification and become fine-tuned as maintenance load increases. These results accord with a network-coding mechanism, where the same brain regions support diverse WM demands by adopting different connectivity states.

Computerized multi-domain cognitive training reduces brain atrophy in patients with amnestic mild cognitive impairment

The present study aimed to explore the effect of computerized multi-domain cognitive training (MDCT) on brain gray matter volume and neuropsychological performance in patients with amnestic mild cognitive impairment (amnestic MCI). Twenty-one patients with amnestic MCI participated in a computerized MDCT program. The program targeted a broad set of cognitive domains via programs focused on reasoning, memory, visuospatial, language, calculation, and attention. Seventeen Participants completed the intervention and all completed a battery of neuropsychological tests to evaluate cognitive function while 12 out of 17 underwent 3 T MRI scanning before and after the intervention to measure gray matter (GM) volume. We examined correlations between the changes in neuropsychological scores and GM volumes across participants after the intervention. After training, we observed significant increases in GM volume in the right angular gyrus (AG) and other parietal subareas near the intraparietal sulcus (p < 0.05, FWE-corrected, 10000 permutations). However, we found no significant changes in neuropsychological test scores (p > 0.05). A correlation analysis revealed positive correlations between the changes in GM volume in the right AG and scores in the immediate recall component of the Hopkins Verbal Learning Test-Revised (HVLT-R) (r = 0.64, p = 0.024) and the Brief Visuospatial Memory Test-Revised (BVMT-R) (r = 0.67, p = 0.016). Our findings indicate that a computerized MDCT program may protect patients with amnestic MCI against brain GM volume loss and has potential in preserving general cognition. Thus, our non-pharmacological intervention may slow the rate of disease progression.

A step-by-step translation of evidence into a psychosocial intervention for everyday activities in dementia: a focus group study

OBJECTIVE

In order to increase the efficacy of psychosocial interventions in dementia, a step-by-step process translating evidence and public engagement should be adhered to. This paper describes such a process by involving a two-stage focus group with people with dementia (PwD), informal carers, and staff.

METHODS

Based on previous evidence, general aspects of effective interventions were drawn out. These were tested in the first stage of focus groups, one with informal carers and PwD and one with staff. Findings from this stage helped shape the intervention further specifying its content. In the second stage, participants were consulted about the detailed components.

FINDINGS

The extant evidence base and focus groups helped to identify six practical and situation-specific elements worthy of consideration in planning such an intervention, including underlying theory and personal motivations for participation. Carers, PwD, and staff highlighted the importance of rapport between practitioners and PwD prior to commencing the intervention. It was also considered important that the intervention would be personalised to each individual.

CONCLUSIONS

This paper shows how valuable public involvement can be to intervention development, and outlines a process of public involvement for future intervention development. The next step would be to formally test the intervention.

Online assessment of risk factors for dementia and cognitive function in healthy adults

OBJECTIVE

Several potentially modifiable risk factors for cognitive decline and dementia have been identified, including low educational attainment, smoking, diabetes, physical inactivity, hypertension, midlife obesity, depression, and perceived social isolation. Managing these risk factors in late midlife and older age may help reduce the risk of dementia; however, it is unclear whether these factors also relate to cognitive performance in older individuals without dementia.

METHOD

Data from 14 201 non-demented individuals aged >50 years who enrolled in the online PROTECT study were used to examine the relationship between cognitive function and known modifiable risk factors for dementia. Multivariate regression analyses were conducted on 4 cognitive outcomes assessing verbal and spatial working memory, visual episodic memory, and verbal reasoning.

RESULTS

Increasing age was associated with reduced performance across all tasks. Higher educational achievement, the presence of a close confiding relationship, and moderate alcohol intake were associated with benefits across all 4 cognitive tasks, and exercise was associated with better performance on verbal reasoning and verbal working memory tasks. A diagnosis of depression was negatively associated with performance on visual episodic memory and working memory tasks, whereas being underweight negatively affected performance on all tasks apart from verbal working memory. A history of stroke was negatively associated with verbal reasoning and working memory performance.

CONCLUSION

Known modifiable risk factors for dementia are associated with cognitive performance in non-demented individuals in late midlife and older age. This provides further support for public health interventions that seek to manage these risk factors across the lifespan.

Functional neuroanatomical associations of working memory in early-onset Alzheimer's disease

OBJECTIVE

To characterize metabolic correlates of working memory impairment in clinically defined subtypes of early-onset Alzheimer's disease.

BACKGROUND

Established models of working memory suggest a key role for frontal lobe function, yet the association in Alzheimer's disease between working memory impairment and visuospatial and language symptoms suggests that temporoparietal neocortical dysfunction may be responsible.

METHODS

Twenty-four patients with predominantly early-onset Alzheimer's disease were clinically classified into groups with predominantly amnestic, multidomain or visual deficits. Patients underwent neuropsychological evaluation focused on the domains of episodic and working memory, T1-weighted magnetic resonance imaging and brain fluorodeoxyglucose positron emission tomography. Fluorodeoxyglucose positron emission tomography data were analysed by using a region-of-interest approach.

RESULTS

Patients with multidomain and visual presentations performed more poorly on tests of working memory compared with amnestic Alzheimer's disease. Working memory performance correlated with glucose metabolism in left-sided temporoparietal, but not frontal neocortex. Carriers of the apolipoprotein E4 gene showed poorer episodic memory and better working memory performance compared with noncarriers.

CONCLUSIONS

Our findings support the hypothesis that working memory changes in early-onset Alzheimer's disease are related to temporoparietal rather than frontal hypometabolism and show dissociation from episodic memory performance. They further support the concept of subtypes of Alzheimer's disease with distinct cognitive profiles due to prominent neocortical dysfunction early in the disease course. Copyright © 2017 John Wiley & Sons, Ltd.