Shannon Z. Klekociuk

Absence of a relationship between subjective memory complaint and objective memory impairment in mild cognitive impairment (MCI): is it time to abandon subjective memory complaint as an MCI diagnostic criterion?

BACKGROUND Subjective memory complaints are a requirement in the diagnosis of mild cognitive impairment (MCI) as they are thought to indicate a decline in objective memory performance. However, recent research suggests that the relationship between subjective memory complaint and objective memory impairment is less clear. Thus, it is possible that many people without subjective memory complaints who develop Alzheimers disease are precluded from a diagnosis of MCI. METHODS The present study examined the relationship between subjective memory complaint assessed using the Multifactorial Memory Questionnaire (MMQ) and objective memory impairment assessed using standard neuropsychological measures in cases of amnestic MCI (n = 48), non-amnestic MCI (n = 27), and unimpaired healthy participants (n = 64). RESULTS Correlational and regression analyses indicated that subjective memory complaints displayed a poor relationship with objective memory performance. A subsequent discriminant function analysis indicated that subjective memory complaints failed to improve the diagnostic accuracy of MCI and resulted in increased rates of false negative and false positive diagnoses. CONCLUSION The results of the present study suggest that a diagnostic criterion of subjective memory complaint reduces the accuracy of MCI diagnosis, resulting in an elevated rate of false positive and false negative diagnoses. The results of this study in conjunction with recent research indicate that a criterion of subjective memory complaint should be discarded from emerging diagnostic criteria for MCI.

Reducing false positive diagnoses in mild cognitive impairment: the importance of comprehensive neuropsychological assessment

Longitudinal studies of mild cognitive impairment (MCI) report that a sizeable proportion of MCI cases revert to normal levels of functioning over time. The rate of recovery from MCI indicates that existing MCI diagnostic criteria result in an unacceptably high rate of false positive diagnoses and lack adequate sensitivity and specificity.

Lowered performance in working memory and attentional sub-processes are most prominent in multi-domain amnestic mild cognitive impairment subtypes

Research suggests that working memory and attention deficits may be present in mild cognitive impairment (MCI). However, the functional status of these domains within revised MCI subtypes remains unclear, particularly because previous studies have examined these cognitive domains with the same tests that were used to classify MCI subtypes. The aim of this study was to examine working memory and attention function in MCI subtypes on a battery of neuropsychological tests that were distinct from those used to classify MCI subtypes

Exploring the validity of mild cognitive impairment (MCI) subtypes: Multiple-domain amnestic MCI is the only identifiable subtype at longitudinal follow-up

Background: Epidemiological research exploring risk factors for Alzheimer’s dementia resulted in the identification of the mild cognitive impairment (MCI) profile. Subsequently, distinct subtypes of MCI have been proposed; however, the validity of these as diagnostic entities remains uncertain. Design and participants: The aim of the present study was to examine the longitudinal neuropsychological profiles of MCI subtypes. A total of 118 adults aged 60–90 years were classified at screening as amnestic (a-MCI), nonamnestic (na-MCI), and multiple-domain amnestic (a-MCI+) and were assessed at two time points across 20 months on a comprehensive neuropsychological assessment battery. Results: The a-MCI+ group displayed the poorest performance of all groups in terms of episodic memory, working memory, attention, and executive functioning. Conclusions: These findings suggest that the a-MCI+ subtype is the only variant that is recognizable via neuropsychological testing. In contrast, the differentiation between single-domain subtypes and healthy controls is difficult and may not be achievable through current neuropsychological assessment practices.

The learning profile of persistent mild cognitive impairment (MCI): a potential diagnostic marker of persistent amnestic MCI

Previous research examining mild cognitive impairment (MCI) has highlighted the heterogeneity of outcome in MCI sufferers. MCI is associated with greater risk of progression to dementia; however, a substantial proportion of those identified with MCI have alternative outcomes including recovery to unimpaired status. This heterogeneity may in part reflect insufficient sensitivity and specificity in identifying subclinical memory impairment.

The BDNF Val66Met polymorphism moderates the effect of cognitive reserve on 36-month cognitive change in healthy older adults

Cognitive reserve (CR) and BDNF Val66Met are independently associated with the rate of cognitive decline in preclinical Alzheimers disease. This study was designed to investigate the interactive effects of these variables on 36‐month cognitive change in cognitively intact older adults.

The Self-Fulfilling Prophecy of Episodic Memory Impairment in Mild Cognitive Impairment: Do Episodic Memory Deficits Identified at Classification Remain Evident When Later Examined with Different Memory Tests?

Previous studies of mild cognitive impairment (MCI) have been criticised for using the same battery of neuropsychological tests during classification and longitudinal followup. The key concern is that there is a potential circularity when the same tests are used to identify MCI and then subsequently monitor change in function over time. The aim of the present study was to examine the evidence of this potential circularity problem. The present study assessed the memory function of 72 MCI participants and 50 healthy controls using an alternate battery of visual and verbal episodic memory tests 9 months following initial comprehensive screening assessment and MCI classification. Individuals who were classified as multiple-domain amnestic MCI (a-MCI+) at screening show a significantly reduced performance in visual and verbal memory function at followup using a completely different battery of valid and reliable tests. Consistent with their initial classification, those identified as nonamnestic MCI (na-MCI) or control at screening demonstrated the highest performance across the memory tasks. The results of the present study indicate that persistent memory deficits remain evident in amnestic MCI subgroups using alternate memory tests, suggesting that the concerns regarding potential circularity of logic may be overstated in MCI research.

Improving Knowledge and Practice through Massive Open Online Dementia Education: The Understanding Dementia and Preventing Dementia MOOCs

Background: There is a documented need and growing demand for evidence-based consumer-friendly education to enable more effective dementia care and wider adoption of strategies to prevent dementia. The Wicking Dementia Research and Education Centre developed the Understanding Dementia Massive Open Online Course (UD-MOOC) to increase knowledge of dementia and person-centred care practices, particularly for those providing care. The Centre’s Preventing Dementia MOOC (PD-MOOC) was developed to educate people on the scientific basis of dementia risk reduction, both those interested in reducing their own risk, and those providing related services. Methods: The 9-week UD-MOOC examined how the brain is affected by diseases that cause dementia, symptoms, diagnosis, stages, management, and perspectives of those affected and caregivers. The 5-week PD-MOOC explored non-modifiable and modifiable risk factors, myths about dementia risk and causes, and barriers and enablers of health-behaviour change. MOOC completion was defined as a passing grade of 70% on 3 quizzes. To assess MOOC impact, completing participants were asked how they had applied knowledge gained and a natural-language processing algorithm was used to identify common themes. Results: Six iterations of the UD-MOOC from 2013 to 2017 attracted a total of 119,611 enrolments, with 47,793 (40%) completing the course. Two offerings of the PD-MOOC in 2016 and 2017 attracted 27,048 enrolments and 13,778 (51%) completed. 76% of 2017 UD-MOOC and 75% of 2017 PD-MOOC feedback survey respondents agreed they had already applied the knowledge gained from the MOOC. Thematic analyses revealed UD-MOOC completers were applying a more person-centred approach to care, changing work practices, and sharing knowledge with others, and had improved understanding of dementia, and more empathy for and confidence in supporting people experiencing dementia. PD-MOOC completers specified they were increasing physical, social and cognitive activity, improving their diet, losing weight, having check-ups for vascular risk factors, more motivated to reduce their risk, and sharing knowledge with others. Conclusions: The large enrolments and high completion rates for Wicking’s dementia MOOCs highlight the scale of demand for accessible quality dementia education. Participant feedback demonstrates that the MOOCs are improving both knowledge and practice, with potential large-scale impacts for dementia care and prevention.

Validation of a Dynamic Measure of Current Cognitive Reserve in a Longitudinally Assessed Sample of Healthy Older Adults: The Tasmanian Healthy Brain Project

Cognitive reserve (CR) is a theoretical construct describing the underlying cognitive capacity of an individual that confers differential levels of resistance to, and recovery from, brain injuries of various types. To date, estimates of an individual’s level of CR have been based on single proxy measures that are retrospective and static in nature. To develop a measure of dynamic change in CR across a lifetime, we previously identified a latent factor, derived from an exploratory factor analysis of a large sample of healthy older adults, as current CR (cCR). In the present study, we examined the longitudinal results of a sample of 272 older adults enrolled in the Tasmanian Healthy Brain Project. Using results from 12-month and 24-month reassessments, we examined the longitudinal validity of the cCR factor using confirmatory factor analyses. The results of these analyses indicate that the cCR factor structure is longitudinally stable. These results, in conjunction with recent results from our group demonstrating dynamic increases in cCR over time in older adults undertaking further education, lend weight to this cCR measure being a valid estimate of dynamic change in CR over time.

BUILDING CAPACITY FOR DEMENTIA RISK REDUCTION: THE PREVENTING DEMENTIA MOOC

theDSE group during the intervention period.During 5 years spanning the intervention’s end and post-intervention follow-up, repeated cognitive assessments were obtained in 1,091 individuals who had been assigned to ILI or DSE. Results:Compared with DSE, assignment to ILI was associated with a mean 0.082 standard deviation (SD) relative deficit in global cognitive function (p1⁄40.010) over time. However, overweight (body mass index <30 kg/m) ILI participants had mean [95% confidence interval] 0.099 [-0.006,0.259] SD better composite cognitive function scores across follow-up while obese (body mass index >30 kg/m) ILI participants had -0.117 [-0.185, -0.049] worse mean composite cognitive function scores (interaction p1⁄40.014). For both overweight and obese participants, cognitive decline was steeper for ILI compared with DSE participants, with differences reaching nominal significance for tests of attention (p1⁄40.037) and memory (p1⁄40.031), andmarginal significance for composite cognitive function (p1⁄40.068).Conclusions:Long-term behavioral weight loss intervention was not associated with lasting cognitive benefits in adults with type 2 diabetes, and potentially small relative mean deficits among individuals who are obese.