Nicola Gates

Cognitive and memory training in adults at risk of dementia: A Systematic Review

BackgroundEffective non-pharmacological cognitive interventions to prevent Alzheimers dementia or slow its progression are an urgent international priority. The aim of this review was to evaluate cognitive training trials in individuals with mild cognitive impairment (MCI), and evaluate the efficacy of training in memory strategies or cognitive exercises to determine if cognitive training could benefit individuals at risk of developing dementia.MethodsA systematic review of eligible trials was undertaken, followed by effect size analysis. Cognitive training was differentiated from other cognitive interventions not meeting generally accepted definitions, and included both cognitive exercises and memory strategies.ResultsTen studies enrolling a total of 305 subjects met criteria for cognitive training in MCI. Only five of the studies were randomized controlled trials. Meta-analysis was not considered appropriate due to the heterogeneity of interventions. Moderate effects on memory outcomes were identified in seven trials. Cognitive exercises (relative effect sizes ranged from .10 to 1.21) may lead to greater benefits than memory strategies (.88 to -1.18) on memory.ConclusionsPrevious conclusions of a lack of efficacy for cognitive training in MCI may have been influenced by not clearly defining the intervention. Our systematic review found that cognitive exercises can produce moderate-to-large beneficial effects on memory-related outcomes. However, the number of high quality RCTs remains low, and so further trials must be a priority. Several suggestions for the better design of cognitive training trials are provided.

The effect of exercise training on cognitive function in older adults with mild cognitive impairment: a meta-analysis of randomized controlled trials.

OBJECTIVES Investigations of exercise and cognition have primarily focused on healthy or demented older adults, and results have been equivocal in individuals with mild cognitive impairment (MCI). Our aim was to evaluate efficacy of exercise on cognition in older adults with MCI. DESIGN We conducted a meta-analysis of random controlled trials (RCTs) of exercise effects on cognitive outcomes in adults with MCI. Searches were conducted in Medline, EMBASE, CINAHL, PEDro, SPORTSDICUS, PsychInfo, and PubMed. PARTICIPANTS Adults aged over 65 years with MCI or Mini-Mental State Exam mean score 24-28 inclusive. MEASUREMENTS Study quality was assessed using the PEDro scale; data on participant and intervention characteristics and outcomes were extracted, followed by meta-analysis. RESULTS Fourteen RCTs (1,695 participants; age 65-95 years) met inclusion criteria. Quality was modest and under-powering for small effects prevalent. Overall, 42% of effect sizes (ESs) were potentially clinically relevant (ES >0.20) with only 8% of cognitive outcomes statistically significant. Meta-analysis revealed negligible but significant effects of exercise on verbal fluency (ES: 0.17 [0.04, 0.30]). No significant benefit was found for additional executive measures, memory, or information processing. Overall results were inconsistent with benefits varying across exercise types and cognitive domains. CONCLUSIONS There is very limited evidence that exercise improves cognitive function in individuals with MCI, although published research is of moderate quality and inconclusive due to low statistical power. Questions remain regarding the magnitude, generalization, persistence, and mechanisms of benefits. Large-scale, high-quality RCTs are required to determine if exercise improves cognition or reduces dementia incidence in those with MCI.

Cognitive Exercise and Its Role in Cognitive Function in Older Adults

Converging lines of research indicate that complex mental activity is associated with reduced dementia risk. Thus, intense interest exists in whether different forms of cognitive exercise can help protect against cognitive decline and dementia. However, there is considerable confusion in terminology that is hindering progress in the field. We therefore introduce a concrete definition of cognitive training (CT) and make this the focus of our article. Clinical research that has evaluated CT in normal aging, mild cognitive impairment, and dementia is then critically reviewed. Despite many methodological shortcomings, the overall findings indicate that multidomain CT has the potential to improve cognitive function in healthy older adults and slow decline in affected individuals. Finally, practical issues, including the strengths and weaknesses of commercial products, are explored, and recommendations for further research and clinical implementation are made.

The Study of Mental and Resistance Training (SMART) study—resistance training and/or cognitive training in mild cognitive impairment: a randomized, double-blind, double-sham controlled trial.

BACKGROUND Mild cognitive impairment (MCI) increases dementia risk with no pharmacologic treatment available. METHODS The Study of Mental and Resistance Training was a randomized, double-blind, double-sham controlled trial of adults with MCI. Participants were randomized to 2 supervised interventions: active or sham physical training (high intensity progressive resistance training vs seated calisthenics) plus active or sham cognitive training (computerized, multidomain cognitive training vs watching videos/quizzes), 2-3 days/week for 6 months with 18-month follow-up. Primary outcomes were global cognitive function (Alzheimers Disease Assessment Scale-cognitive subscale; ADAS-Cog) and functional independence (Bayer Activities of Daily Living). Secondary outcomes included executive function, memory, and speed/attention tests, and cognitive domain scores. RESULTS One hundred adults with MCI [70.1 (6.7) years; 68% women] were enrolled and analyzed. Resistance training significantly improved the primary outcome ADAS-Cog; [relative effect size (95% confidence interval) -0.33 (-0.73, 0.06); P < .05] at 6 months and executive function (Wechsler Adult Intelligence Scale Matrices; P = .016) across 18 months. Normal ADAS-Cog scores occurred in 48% (24/49) after resistance training vs 27% (14/51) without resistance training [P < .03; odds ratio (95% confidence interval) 3.50 (1.18, 10.48)]. Cognitive training only attenuated decline in Memory Domain at 6 months (P < .02). Resistance training 18-month benefit was 74% higher (P = .02) for Executive Domain compared with combined training [z-score change = 0.42 (0.22, 0.63) resistance training vs 0.11 (-0.60, 0.28) combined] and 48% higher (P < .04) for Global Domain [z-score change = .0.45 (0.29, 0.61) resistance training vs 0.23 (0.10, 0.36) combined]. CONCLUSIONS Resistance training significantly improved global cognitive function, with maintenance of executive and global benefits over 18 months.

Study of Mental Activity and Regular Training (SMART) in at risk individuals: a randomised double blind, sham controlled, longitudinal trial.

BackgroundThe extent to which mental and physical exercise may slow cognitive decline in adults with early signs of cognitive impairment is unknown. This article provides the rationale and methodology of the first trial to investigate the isolated and combined effects of cognitive training (CT) and progressive resistance training (PRT) on general cognitive function and functional independence in older adults with early cognitive impairment: Study of Mental and Regular Training (SMART). Our secondary aim is to quantify the differential adaptations to these interventions in terms of brain morphology and function, cardiovascular and metabolic function, exercise capacity, psychological state and body composition, to identify the potential mechanisms of benefit and broader health status effects.MethodsSMART is a double-blind randomized, double sham-controlled trial. One hundred and thirty-two community-dwelling volunteers will be recruited. Primary inclusion criteria are: at risk for cognitive decline as defined by neuropsychology assessment, low physical activity levels, stable disease, and age over 55 years. The two active interventions are computerized CT and whole body, high intensity PRT. The two sham interventions are educational videos and seated calisthenics. Participants are randomized into 1 of 4 supervised training groups (2 d/wk × 6 mo) in a fully factorial design. Primary outcomes measured at baseline, 6, and 18 months are the Alzheimers Disease Assessment Scale (ADAS-Cog), neuropsychological test scores, and Bayer Informant Instrumental Activities of Daily Living (B-IADLs). Secondary outcomes are psychological well-being, quality of life, cardiovascular and musculoskeletal function, body composition, insulin resistance, systemic inflammation and anabolic/neurotrophic hormones, and brain morphology and function via Magnetic Resonance Imaging (MRI) and Spectroscopy (fMRS).DiscussionSMART will provide a novel evaluation of the immediate and long term benefits of CT, PRT, and combined CT and PRT on global cognitive function and brain morphology, as well as potential underlying mechanisms of adaptation in older adults at risk of further cognitive decline.Trial RegistrationAustralia and New Zealand Clinical Trials Register (ANZCTR): ANZCTRN12608000489392

Is Cognitive Training an Effective Treatment for Preclinical and Early Alzheimer's Disease?

There is much interest in early intervention for the prevention or postponement of dementia in Alzheimers disease (AD). The results of drug trials in this regard have thus far been disappointing, and non-pharmacological interventions are receiving increased attention. One such intervention is complex cognitive activity. Evidence from epidemiological studies suggests that participation in stimulating mental activities is associated with lowered dementia risk. The introduction of novel and complex cognitive interventions to healthy adults and those with cognitive impairment may represent an efficacious treatment option to improve cognition, lower dementia incidence, and slow rate of decline. This review examines the evidence for restorative cognitive training (CT) and addresses a number of clinically relevant issues regarding cognitive benefit and its transfer and persistence. Although the number of randomized controlled trials is limited, preliminary evidence suggests that CT may provide immediate and longer term cognitive benefits which generalize to non-trained domains and non-cognitive functions, with supervised small group multi-domain training providing greatest benefits. Possible neuroplastic mechanisms are discussed, and recommendations for further research and clinical implementation provided.

Mediation of Cognitive Function Improvements by Strength Gains After Resistance Training in Older Adults with Mild Cognitive Impairment: Outcomes of the Study of Mental and Resistance Training

To determine whether improvements in aerobic capacity (VO2peak) and strength after progressive resistance training (PRT) mediate improvements in cognitive function.

Psychological well-being in individuals with mild cognitive impairment

Objectives Cognitive impairments associated with aging and dementia are major sources of burden, deterioration in life quality, and reduced psychological well-being (PWB). Preventative measures to both reduce incident disease and improve PWB in those afflicted are increasingly targeting individuals with mild cognitive impairment (MCI) at early disease stage. However, there is very limited information regarding the relationships between early cognitive changes and memory concern, and life quality and PWB in adults with MCI; furthermore, PWB outcomes are too commonly overlooked in intervention trials. The purpose of this study was therefore to empirically test a theoretical model of PWB in MCI in order to inform clinical intervention. Methods Baseline data from a convenience sample of 100 community-dwelling adults diagnosed with MCI enrolled in the Study of Mental Activity and Regular Training (SMART) trial were collected. A series of regression analyses were performed to develop a reduced model, then hierarchical regression with the Baron Kenny test of mediation derived the final three-tiered model of PWB. Results Significant predictors of PWB were subjective memory concern, cognitive function, evaluations of quality of life, and negative affect, with a final model explaining 61% of the variance of PWB in MCI. Discussion Our empirical findings support a theoretical tiered model of PWB in MCI and contribute to an understanding of the way in which early subtle cognitive deficits impact upon PWB. Multiple targets and entry points for clinical intervention were identified. These include improving the cognitive difficulties associated with MCI. Additionally, these highlight the importance of reducing memory concern, addressing low mood, and suggest that improving a person’s quality of life may attenuate the negative effects of depression and anxiety on PWB in this cohort.

Computerized and on-line neuropsychological testing for late-life cognition and neurocognitive disorders: are we there yet?

Purpose of review Cost-effective, valid, efficient and accessible tests for the detection of late-life neurocognitive disorders are crucial, as early identification facilitates appropriate early intervention. Proponents of computerized neuropsychological assessment devices (CNADs) assert that technology-based assessments improve upon traditional neuropsychological tests. However, there remain fundamental questions of validity, reliability, normative data and administration, raising the question of whether CNADs are appropriate alternatives. Recent findings Since publication of the 2012 American Academy of Clinical Neuropsychology and National Academy of Neuropsychology joint position paper outlining appropriate standards for CNAD development, the field has not significantly advanced, with the majority of recommendations inadequately addressed. Summary Whilst there is a pressing need for innovative and readily applicable cognitive tests, these requirements do not outweigh the necessity for valid measures. Overall, the psychometric quality, standardization, normative data and administration advice of CNADs for neurocognitive disorders are lacking. Therefore, the risk of diagnostic errors is potentially high and poor clinical decisions could potentially arise, having significant impact upon individuals in terms of their well being and access to treatment. We recommend clinicians and researchers make informed decisions about CNAD suitability for their clients and their individual requirements based upon published psychometric and other test information.

A Neuropsychologist’s Guide To Undertaking a Systematic Review for Publication: Making the most of PRISMA Guidelines

There is increasing impetus to improve the quality of research and scientific writing. Systematic reviews provide Class 1 research evidence, are based upon an established rigor and communicate results in a comprehensive manner, and are therefore particularly relevant to clinicians and researchers. Clinician requirements for quality systematic reviews are twofold: to keep up to date with research and to make informed decisions including those required for diagnoses, disease or risk assessment, and treatment. Researchers rely upon quality systematic reviews to compete for diminishing research funds, prove efficacy for intervention trials, and to meet increasing demand for evidence based intervention. However, insufficient systematic reviews are undertaken, and the methodological rigor and quality are often variable. The aim of this article is to guide researchers through the iterative systematic review process in order to improve quality and thereby increase publication rates. The step by step guide provides a road map through the EQUATOR network and practical suggestions in order to meet the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) (Moher et al. 2009) as well as encouraging high standards through the use of quality rating scales. Lastly, information is provided to encourage quantitative analysis to improve the synthesis of results and qualitative interpretation, such as calculating effect sizes or conducting a meta-analyses as the ultimate goal of a systematic review.