A Scoping Review of Alzheimers Disease Hypotheses: An Array of Uni- and Multi-Factorial Theories

Background

There is a common agreement that Alzheimers disease (AD) is inherently complex; otherwise, a general disagreement remains on its etiological underpinning, with numerous alternative hypotheses having been proposed.

Objective

To perform a scoping review of original manuscripts describing hypotheses and theories of AD published in the past decades.

Results

We reviewed 131 original manuscripts that fulfilled our inclusion criteria out of more than 13,807 references extracted from open databases. Each entry was characterized as having a single or multifactorial focus and assigned to one of 15 theoretical groupings. Impact was tracked using open citation tools.

Results

Three stages can be discerned in terms of hypotheses generation, with three quarter of studies proposing a hypothesis characterized as being single-focus. The most important theoretical groupings were the Amyloid group, followed by Metabolism and Mitochondrial dysfunction, then Infections and Cerebrovascular. Lately, evidence towards Genetics and especially Gut/Brain interactions came to the fore.

Conclusions

When viewed together, these multi-faceted reports reinforce the notion that AD affects multiple sub-cellular, cellular, anatomical, and physiological systems at the same time but at varying degree between individuals. The challenge of providing a comprehensive view of all systems and their interactions remains, alongside ways to manage this inherent complexity.

Impaired lexical access for unique entities in individuals with subjective cognitive decline

Subjective cognitive decline (SCD) may serve as an early indicator of Alzheimer's disease (AD). However, accurately quantifying cognitive impairment in SCD is challenging, mainly because existing assessment tools lack sensitivity. This study examined how tasks specifically designed to assess knowledge of famous people, could potentially aid in identifying cognitive impairment in SCD. A total of 60 adults with SCD and 60 healthy controls (HCs) aged 50 to 82 years performed a famous people verbal fluency task and a famous people naming task. In the famous people fluency task, the results showed that the individuals with SCD produced significantly fewer famous names in the total time allowed than the HCs, and this difference was also found in the first and the second time interval. In the famous people naming task, the performance of the SCD group was significantly lower than that of the HC group only in the more recent period of fame. Overall, these results suggest that retrieving the names of famous people was more difficult for people with SCD than for people without cognitive complaints. They also suggest that famous people verbal fluency and naming tasks could be useful in detecting cognitive decline at the preclinical stage of AD.

REM sleep is reduced in late middle-aged and older APOE4 allele carriers

STUDY OBJECTIVES

Apolipoprotein E ɛ4 (APOE4) is the strongest genetic risk factor for Alzheimer's disease (AD). In addition, APOE4 carriers may exhibit sleep disturbances, but conflicting results have been reported, such that there is no clear consensus regarding which aspects of sleep are impacted. Our objective was to compare objective sleep architecture between APOE4 carriers and non-carriers, and to investigate the modulating impact of age, sex, cognitive status and obstructive sleep apnea.

METHODS

198 dementia-free participants aged >55 years old (mean age: 68.7 ± 8.08 years old, 40.91% women, 41 APOE4 carriers) were recruited in this cross-sectional study. They underwent polysomnography, APOE4 genotyping and a neuropsychological evaluation. ANCOVAs assessed the effect of APOE4 status on sleep architecture, controlling for age, sex, cognitive status and the apnea-hypopnea index. Interaction terms were added between APOE4 status and covariates.

RESULTS

REM sleep percentage (F=9.95, p=0.002, ηp2=0.049) and duration (F=9.23, p=0.003, ηp2=0.047) were lower in APOE4 carriers. The results were replicated in a subsample of 112 participants without moderate-to-severe obstructive sleep apnea. There were no significant interactions between APOE4 status and age, sex, cognitive status and obstructive sleep apnea in the whole sample.

CONCLUSIONS

Our results show that APOE4 carriers exhibit lower REM sleep duration, including in cognitively unimpaired individuals, possibly resulting from early neurodegenerative processes in regions involved in REM sleep generation and maintenance.

Challenges and facilitators in the experience of caregiving for an older adult with traumatic brain injury: A longitudinal qualitative study in the first-year postinjury

PURPOSE

To obtain a better understanding of the factors which complicate or facilitate the adjustment of caregivers after traumatic brain injury (TBI) in older adults.

RESEARCH METHOD

At 4, 8, and 12 months post-TBI (mild to severe), 65 caregivers answered two open-ended questions regarding facilitators and challenges linked to the injury of their loved one. A thematic analysis was performed.

RESULTS

Participants mentioned almost as many facilitators as challenges at each time point. Among the facilitators, we found the following themes: receiving social support, having access to rehabilitation, improvement of the injured loved one's health condition, returning to live at home, having access to home services, feeling useful, effective communication, and having time for oneself. The challenges identified were: health issues in the injured loved one, psychological impact on the caregiver, assuming a new role, relationship strain, and decrease in activities and outings.

CONCLUSIONS

During the first year following TBI in older adults, caregivers were able to identify several facilitators despite the presence of challenging factors, suggesting effective coping and resilience. This knowledge can guide potential caregivers in their adaptation after TBI in an older adult, and we propose a simple tool to support this process. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Normative Data for the Judgment of Line Orientation Test (Long and Short Forms) in the Quebec-French Population Aged between 50 and 89 Years

The Judgment of Line Orientation (JLO) Test of Benton assesses visuospatial processing without requiring motor skills. The test is frequently used in geriatric or brain-injured populations. As with other cognitive tests, performance on the JLO test may vary according to age, level of education, sex, and cultural background of individuals. The present study aimed to establish normative data for a short (15 items) and a long (30 items) form of the JLO. The sample for the short and long forms comprised 198 and 260 individuals, respectively, aged 50-89 years. All participants were French-speaking people from the province of Quebec, Canada. Using regression-based norming, the effects of age, years of formal education, and sex on JLO performance were estimated. The normative adjustment of the JLO short and long forms considered the weight of each predictor on test performance. Results indicated that JLO performance was positively associated with years of formal education and male sex, whereas it was negatively associated with age. Accordingly, normative data were generated using Z-scores and adjusted scaled scores derived from the regression equations. To conclude, the present norms will ease the detection of visuospatial impairment in French-Quebec middle-aged and older adults.

Normative Data for the Alternating and Orthographic Constraint Semantic Fluency Tests in the Adult French-Quebec Population and Validation Study in Mild Cognitive Impairment and Alzheimer's Disease

Verbal fluency tests, known to elicit executive functions (EFs), have proven useful in distinguishing healthy individuals from those with cognitive impairment. The present study addresses two new tests of verbal fluency that elicit EFs, namely, extradimensional alternating fluency (EAF) and extradimensional orthographic constraint semantic fluency (EOCSF). The aim of Study 1 was to provide normative data in the adult and elderly population of French Québec for the two fluency tests. The aim of Study 2 was to determine their psychometric value. The normative sample consisted of 338 healthy controls (HCs) aged 50-89 years. Multiple linear regressions were used to generate equations for calculating Z-scores. Convergent validity was established by administering the two verbal fluency tests and the Letter-Number Sequence (LNS) subtest of the WAIS-III. To assess predictive validity, the performance of 19 HCs was compared with that of 19 participants with mild cognitive impairment (MCI) and 19 participants with Alzheimer's disease (AD). To determine test-retest reliability, the test was administered twice, 3 months apart, to a subsample of 20 HCs. Age and educational level were significantly related to performance in the EAF and the EOCSF. The two tests correlated significantly and positively with the LNS. The EAF and the EOCSF distinguished the performance of HCs from that of participants with MCI or AD. A test-retest analysis showed that scores on the two tests were stable over time. The norms and psychometric data for the EAF and the EOCSF will help clinicians and researchers better identify executive impairments associated with pathological conditions.

REM sleep is associated with the volume of the cholinergic basal forebrain in aMCI individuals

BACKGROUND

Rapid-eye movement (REM) sleep highly depends on the activity of cholinergic basal forebrain (BF) neurons and is reduced in Alzheimer's disease. Here, we investigated the associations between the volume of BF nuclei and REM sleep characteristics, and the impact of cognitive status on these links, in late middle-aged and older participants.

METHODS

Thirty-one cognitively healthy controls (66.8 ± 7.2 years old, 13 women) and 31 participants with amnestic Mild Cognitive Impairment (aMCI) (68.3 ± 8.8 years old, 7 women) were included in this cross-sectional study. All participants underwent polysomnography, a comprehensive neuropsychological assessment and Magnetic Resonance Imaging examination. REM sleep characteristics (i.e., percentage, latency and efficiency) were derived from polysomnographic recordings. T1-weighted images were preprocessed using CAT12 and the DARTEL algorithm, and we extracted the gray matter volume of BF regions of interest using a probabilistic atlas implemented in the JuBrain Anatomy Toolbox. Multiple linear regressions were performed between the volume of BF nuclei and REM sleep characteristics controlling for age, sex and total intracranial volume, in the whole cohort and in subgroups stratified by cognitive status.

RESULTS

In the whole sample, lower REM sleep percentage was significantly associated to lower nucleus basalis of Meynert (Ch4) volume (β = 0.32, p = 0.009). When stratifying the cohort according to cognitive status, lower REM sleep percentage was significantly associated to both lower Ch4 (β = 0.48, p = 0.012) and total BF volumes (β = 0.44, p = 0.014) in aMCI individuals, but not in cognitively unimpaired participants. No significant associations were observed between the volume of the BF and wake after sleep onset or non-REM sleep variables.

DISCUSSION

These results suggest that REM sleep disturbances may be an early manifestation of the degeneration of the BF cholinergic system before the onset of dementia, especially in participants with mild memory deficits.

Subjective and objective burden and psychological distress in care partners of older adults with traumatic brain injury

PURPOSE/OBJECTIVE

In care partners of older persons (65 years and older) having sustained traumatic brain injury (TBI), the objectives were (a) to describe subjective burden (emotional, social, financial, and physical burden), objective burden (new roles and responsibilities), and psychological distress at 4 months postinjury, and (b) to explore the predictors of subjective burden and psychological distress.

RESEARCH METHOD/DESIGN

This is an observational study of care partners of older adults with TBI (n = 46; M_age = 65.2 years, SD = 11.2, 87% female). Participants completed the Zarit Burden Interview, the Hospital Anxiety and Depression Scale, the Brain Injury Complaint Questionnaire (measuring difficulties of the injured older adult perceived by the care partner), and the modified Medical Outcomes Study Social Support Survey.

RESULTS

A majority of care partners (88%) reported at least one form of objective burden (e.g., increased/decreased time spent in certain activities post-TBI), 29% perceived at least mild subjective burden, and 27% reported either significant anxiety or depressive symptoms. Linear regressions indicated that a higher number of difficulties reported regarding the injured person and poorer perceived social support predicted higher subjective burden and psychological distress. A younger age of the care partner also predicted a higher subjective burden.

CONCLUSIONS/IMPLICATIONS

This study provides a better understanding of the potential impacts of TBI in older age for care partners. Future research should examine how to support adequately care partners in their psychological adaptation after TBI in an elderly person. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Normative data for the Tower of London (Drexel version) in the Quebec-French population aged between 50 and 88 years

The Tower of London (ToL) is a neuropsychological test used to assess several executive functions such as strategical reasoning, mental planning, and problem-solving. Like other cognitive tests, performance on the ToL can vary according to age, level of education, sex, and cultural background of individuals. The present study aimed to establish normative data for the Drexel version of the ToL among French-Quebec people aged 50 years and over. The normative sample consisted of 174 healthy individuals aged 50-88 years, all from the province of Quebec, Canada. Analyses were performed to estimate the associations between age, sex, and education level on one hand, and ToL performance, on the other hand. Results indicated that Total Execution Time was associated with age, whereas the Total Type II Errors and Total Rule Violation score (Type I + II Errors) were associated with both age and education level. All other scores were not significantly associated with the demographic characteristics of the participants. Since the distributions of the data were all skewed, the normative data are presented in the form of percentile ranks. To conclude, the present norms will ease the detection of executive impairments in French-Quebec middle-aged and older adults.

Normative data for the 12-item Buschke memory task in the Quebec-French population aged 50 and over

OBJECTIVE

The 12-item Buschke memory test is used to assess verbal episodic memory in adults and older adults. However, there is no normative data for this test adjusted to the older Quebec-French population. The aim of the study was to produce normative data for the 12-item Buschke for the Quebec-French population aged 50 and older.

METHOD

The normative sample consisted of 172 healthy French-speaking participants aged 50-89 years, from the Province of Quebec (Canada). The influence of age, years of formal education, and sex on five 12-item Buschke scores were analyzed. Based on the distribution of scores, normative data were developed as Z-scores equation, regression equation, and percentiles.

RESULTS

Age, years of formal education, and sex were all associated with performance. Equations to calculate Z-scores were provided for the free recall trial 1 and the free recall trials 1-3. Stratified percentiles were provided for the delayed free recall and total recall 1-3.

CONCLUSIONS

The normative data for the 12-item Buschke improve the accuracy of clinicians to detect verbal episodic memory impairments in Quebec's aging population.

Normative data for the verb fluency test in the adult French-Quebec population and validation study in mild cognitive impairment

Verbal fluency tests are used to assess executive functions and language. The verb fluency test has proven successful in distinguishing healthy individuals (HCs) from participants with pathological conditions. However, few normative and psychometric studies have been published for the verb fluency test. The aim of Study 1 was to provide normative data in the adult population of French Québec for the verb fluency test. The aim of Study 2 was to determine its discriminant validity and test-retest reliability. The normative sample consisted of 424 HCs aged 50-92 years. Multiple linear regressions were used to generate equations for calculating Z-scores. To assess discriminant validity, the performance of 46 HCs was compared with that of 46 participants with mild cognitive impairment (MCI). To determine test-retest reliability, the test was administered twice, 3 months apart, to a group of 25 HCs. Age, sex, and education level were significantly related to performance on the test. The test distinguished the performance of HCs from that of participants with MCI. Test-retest analysis showed that scores had good stability over time. Norms and psychometric data for the verb fluency test will help clinicians and researchers better identify executive and language impairments associated with pathological conditions.

Preliminary Validation Study of the French-Quebec Version of the Mild Behavioral Impairment Checklist

BACKGROUND

Alzheimer disease dementia may be preceded by cognitive stages during which behavioral and psychological changes can occur. More precisely, behavioral symptoms may be observed during the subjective cognitive decline (SCD) or the mild cognitive impairment (MCI) stages; these symptoms can be measured using the Mild Behavioral Impairment Checklist (MBI-C).

OBJECTIVE

To validate the French-Quebec version of the MBI-C in individuals ages 60-85 years.

METHOD

The sample included 60 participants (20 MCI, 20 SCD, 20 cognitively healthy) and their informants. To assess the discriminant validity of the MBI-C, a Kruskal-Wallis analysis with a multiple comparisons test was performed on the MBI-C Total score. To determine convergent validity, Spearman correlations were calculated between the MBI-C subscales and a set of validation tools. Finally, test-retest reliability was assessed with Spearman correlations of MBI-C scores between two test sessions.

RESULTS

All of the analyses indicated satisfactory psychometric properties for the French-Quebec version of the MBI-C.

CONCLUSION

This validation study reveals that the MBI-C can be used successfully in dementia risk assessments. From now on, the use of a validated MBI-C will be possible in the French-Quebec population.

Validation of and Normative Data of the DVAQ-30, a New Video-Naming Test for Assessing Verb Anomia

OBJECTIVE

Anomia is usually assessed using picture-naming tests. While many tests evaluate anomia for nouns, very few tests have been specifically designed for verb anomia. This article presents the DVAQ-30, a new naming test for detecting verb anomia in adults and elderly people.

METHOD

The article describes three studies. Study 1 focused on the DVAQ-30 development phase. In Study 2, healthy participants and individuals with post-stroke aphasia, mild cognitive impairment, Alzheimer's disease, or primary progressive aphasia were assessed using the DVAQ-30 to establish its convergent and discriminant validity, test-retest reliability, and internal consistency. In Study 3, a group of adults and elderly Quebec French-speaking adults were assessed to obtain normative data.

RESULTS

The DVAQ-30 had good convergent validity and distinguished the performance of healthy participants from that of participants with pathological conditions. The test also had good internal consistency, and the test-retest analysis showed that the scores had good temporal stability. Furthermore, normative data were collected on the performance of 244 participants aged 50 years old and over.

CONCLUSIONS

The DVAQ-30 fills an important gap and has the potential to help clinicians and researchers better detect verb anomia associated with pathological aging and post-stroke aphasia.

Longitudinal association between ß-amyloid accumulation and cognitive decline in cognitively healthy older adults: A systematic review

This systematic review examined the longitudinal association between amyloid-β (Aβ) accumulation and cognitive decline in cognitively healthy adults. It was conducted using the PubMed, Embase, PsycInfo, and Web of Science databases. The methodological quality of the selected articles was assessed. In fine, seventeen longitudinal clinical studies were included in this review. A minority (seven out of 17) of studies reported a statistically significant association or prediction of cognitive decline with Aβ change, measured by positron emission tomography (PET; n = 6) and lumbar puncture (n = 1), with a mean follow-up duration of 3.17 years for cognition and 2.99 years for Aβ. The studies reporting significant results with PET found differences in the frontal, posterior cingular, lateral parietal and global (whole brain) cortices as well as in the precuneus. Significant associations were found with episodic memory (n = 6) and global cognition (n = 1). Five of the seven studies using a composite cognitive score found significant results. A quality assessment revealed widespread methodological biases, such as failure to report or account for loss-to follow up and missing data, and failure to report p-values and effect sizes of non-significant results. Overall, the longitudinal association between Aβ accumulation and cognitive decline in preclinical Alzheimer's disease remains unclear. The discrepancy in results between studies may be explained in part by the choice of neuroimaging technique used to measure Aβ change, the duration of longitudinal studies, the heterogeneity of the healthy preclinical population, and importantly, the use of a composite score to capture cognitive changes with increased sensitivity. More longitudinal studies with larger sample sizes are needed to elucidate this relationship.

It's all about cognitive trajectory: Accuracy of the cognitive charts-MoCA in normal aging, MCI, and dementia

BACKGROUND

The Montreal Cognitive Assessment (MoCA) is an established cognitive screening tool in older adults. It remains unclear, however, how to interpret its scores over time and distinguish age-associated cognitive decline (AACD) from early neurodegeneration. We aimed to create cognitive charts using the MoCA for longitudinal evaluation of AACD in clinical practice.

METHODS

We analyzed data from the National Alzheimer's Coordinating Center (9684 participants aged 60 years or older) who completed the MoCA at baseline. We developed a linear regression model for the MoCA score as a function of age and education. Based on this model, we generated the Cognitive Charts-MoCA designed to optimize accuracy for distinguishing participants with MCI and dementia from healthy controls. We validated our model using two separate data sets.

RESULTS

For longitudinal evaluation of the Cognitive Charts-MoCA, sensitivity (SE) was 89%, 95% confidence interval (CI): [86%, 92%] and specificity (SP) 79%, 95% CI: [77%, 81%], hence showing better performance than fixed cutoffs of MoCA (SE 82%, 95% CI: [79%, 85%], SP 68%, 95% CI: [67%, 70%]). For current cognitive status or baseline measurement, the Cognitive Charts-MoCA had a SE of 81%, 95% CI: [79%, 82%], SP of 84%, 95% CI: [83%, 85%] in distinguishing healthy controls from mild cognitive impairment or dementia. Results in two additional validation samples were comparable.

CONCLUSIONS

The Cognitive Charts-MoCA showed high validity and diagnostic accuracy for determining whether older individuals show abnormal performance on serial MoCAs. This innovative model allows longitudinal cognitive evaluation and enables prompt initiation of investigation and treatment when appropriate.

The Influence of Birth Cohorts on Future Cognitive Decline

BACKGROUND

Slowed rates of cognitive decline have been reported in individuals with higher cognitive reserve (CR), but interindividual discrepancies remain unexplained. Few studies have reported a birth cohort effect, favoring later-born individuals, but these studies remain scarce.

OBJECTIVE

We aimed to predict cognitive decline in older adults using birth cohorts and CR.

METHODS

Within the Alzheimer's Disease Neuroimaging Initiative, 1,041 dementia-free participants were assessed on four cognitive domains (verbal episodic memory; language and semantic memory; attention; executive functions) at each follow-up visit up to 14 years. Four birth cohorts were formed according to the major historical events of the 20th century (1916-1928; 1929-1938; 1939-1945; 1946-1962). CR was operationalized by merging education, complexity of occupation, and verbal IQ. We used linear mixed-effect models to evaluate the effects of CR and birth cohorts on rate of performance change over time. Age at baseline, baseline structural brain health (total brain and total white matter hyperintensities volumes), and baseline vascular risk factors burden were used as covariates.

RESULTS

CR was only associated with slower decline in verbal episodic memory. However, more recent birth cohorts predicted slower annual cognitive decline in all domains, except for executive functions. This effect increased as the birth cohort became more recent.

CONCLUSION

We found that both CR and birth cohorts influence future cognitive decline, which has strong public policy implications.

Psychological Distress, Cognition, and Functional Disability Trajectory Profiles of Aging in Primary Care Older Adults

OBJECTIVES

To identify profiles of aging by combining psychological distress, cognition and functional disability, and their associated factors.

METHODS

Data were drawn from the Étude sur la Santé des Aînés-Services study and included 1585 older adults. Sociodemographic, psychosocial, lifestyle and health factors were informed from structured interviews. Group-based multi-trajectory modeling and multinomial logistic regression were used to identify aging profiles and correlates. Sampling weights were applied to account for the sampling plan.

RESULTS

The weighted sample size was 1591. Three trajectories were identified: a favorable (79.0%), intermediate (14.5%), and severe scenario (6.5%). Factors associated with the severe scenario were older age, male gender, lower education, the presence of anxiety disorders, low physical activity, and smoking. Membership in the intermediate scenario was associated with daily hassles, physical disorders, anxiety and depression, antidepressant/psychotherapy use, low physical activity, and no alcohol use. High social support was protective against less favorable profiles.

CONCLUSIONS

Symptoms of anxiety and depression and high burden of physical disorders were associated with less favorable trajectories. Modifiable lifestyle factors have a significant effect on healthy aging.

CLINICAL IMPLICATIONS

Assessment and management of anxio-depressive symptoms are important in older adults. Clinical interventions including access to psychotherapy and promotion of healthier lifestyles should be considered.

Hippocampal Volume and Episodic Associative Memory Identify Memory Risk in Subjective Cognitive Decline Individuals in the CIMA-Q Cohort, Regardless of Cognitive Reserve Level and APOE4 Status

BACKGROUND

Subjective cognitive decline (SCD) was proposed to identify older adults who complain about their memory but perform within a normal range on standard neuropsychological tests. Persons with SCD are at increased risk of dementia meaning that some SCD individuals experience subthreshold memory decline due to an underlying progression of Alzheimer's disease (AD).

OBJECTIVE

Our main goal was to determine whether hippocampal volume and APOE4, which represent typical AD markers, predict inter-individual differences in memory performance among SCD individuals and can be used to identify a meaningful clinical subgroup.

METHODS

Neuropsychological assessment, structural MRI, and genetic testing for APOE4 were administered to one hundred and twenty-five older adults over the age of 65 from the CIMAQ cohort: 66 SCD, 29 individuals with mild cognitive impairment (MCI), and 30 cognitively intact controls (CTRLS). Multiple regression models were first used to identify which factor (hippocampal volume, APOE4 allele, or cognitive reserve) best predicted inter-individual differences in a Face-name association memory task within the SCD group.

RESULTS

Hippocampal volume was found to be the only and best predictor of memory performance. We then compared the demographic, clinical and cognitive characteristics of two SCD subgroups, one with small hippocampal volume (SCD/SH) and another with normal hippocampal volume (SCD/NH), with MCI and CTRLS. SCD/SH were comparable to MCI on neuropsychological tasks evaluating memory (i.e., test of delayed word recall), whereas SCD/NH were comparable to CTRLS.

CONCLUSION

Thus, using hippocampal volume allows identification of an SCD subgroup with a cognitive profile consistent with a higher risk of conversion to AD.

Normative data for the Color Trails Test in middle-aged and elderly Quebec-French people

OBJECTIVE

Despite the widespread use of the Color Trails Test (CTT) in clinical and research settings, information regarding the impact of sociodemographic variables on test performance in Quebec-French adults and elderly people is non-existent. This study aimed to establish French-Quebec normative data for error scores and completion time on all test trials (CTT1 and CTT2) taking into account the impact of age, education, and sex on test performance.

METHOD

The sample consisted of 169 community-dwelling and healthy Quebec-French individuals aged between 50 and 90 years and having between 6 and 21 years of formal education.

RESULTS

Regression analyses indicated that age was associated with completion time on CTT1 and CTT2. Spearman correlations also revealed that age was positively associated with error scores (CTT1 errors, CTT2 number errors, CTT2 near-misses) and index interference. Education was marginally associated with CTT1 but was not associated with CTT2 completion time or interference index. Education was only associated with the number of errors in the CTT2. Finally, sex was not associated with any variables. Equations to calculate Z scores and percentiles are presented.

CONCLUSIONS

Norms for the CTT will ease the interpretation of executive functioning in Quebec-French adults and the elderly and favor accurate discrimination between normal and pathological cognitive states.

Normative data for the story recall subtest of the BEM-144 in the Quebec-French population aged 50 years and over

OBJECTIVE

The story recall subtest of the Batterie d'Efficience Mnésique (BEM-144) is a verbal episodic memory test that assesses immediate and episodic memory. Variables such as age, sex, and education level can impact performance on this type of memory test, as can cultural differences. Therefore, the purpose of this study was to establish normative data for the story recall subtest of the BEM-144 in the elderly French-Quebec population.

METHOD

The normative sample consisted of 260 healthy individuals aged 50-90 years, all from the province of Quebec, Canada. Analyses were performed to estimate the association between age, sex, and education level on one hand, and immediate and delayed recall performance, on the other hand.

RESULTS

The results show that all sociodemographic variables are significantly associated with story recall performance. Normative data are proposed in the form of regression equations.

CONCLUSIONS

Overall, these norms will be beneficial for the evaluation and detection of episodic memory impairment in middle-aged and older adults.

Medial temporal lobe and obstructive sleep apnea: Effect of sex, age, cognitive status and free-water

Medial temporal structures, namely the hippocampus, the entorhinal cortex and the parahippocampal gyrus, are particularly vulnerable to Alzheimer's disease and hypoxemia. Here, we tested the associations between obstructive sleep apnea (OSA) severity and medial temporal lobe volumes in 114 participants aged 55-86 years (35 % women). We also investigated the impact of sex, age, cognitive status, and free-water fraction correction on these associations. Increased OSA severity was associated with larger hippocampal and entorhinal cortex volumes in women, but not in men. Greater OSA severity also correlated with increased hippocampal volumes in participants with amnestic mild cognitive impairment, but not in cognitively unimpaired participants, regardless of sex. Using free-water corrected volumes eliminated all significant associations with OSA severity. Therefore, the increase in medial temporal subregion volumes may possibly be due to edema. Whether these structural manifestations further progress to neuronal death in non-treated OSA patients should be investigated.

Does culture shape our understanding of others' thoughts and emotions? An investigation across 12 countries

Measures of social cognition have now become central in neuropsychology, being essential for early and differential diagnoses, follow-up, and rehabilitation in a wide range of conditions. With the scientific world becoming increasingly interconnected, international neuropsychological and medical collaborations are burgeoning to tackle the global challenges that are mental health conditions. These initiatives commonly merge data across a diversity of populations and countries, while ignoring their specificity.

OBJECTIVE

In this context, we aimed to estimate the influence of participants' nationality on social cognition evaluation. This issue is of particular importance as most cognitive tasks are developed in highly specific contexts, not representative of that encountered by the world's population.

METHOD

Through a large international study across 18 sites, neuropsychologists assessed core aspects of social cognition in 587 participants from 12 countries using traditional and widely used tasks.

RESULTS

Age, gender, and education were found to impact measures of mentalizing and emotion recognition. After controlling for these factors, differences between countries accounted for more than 20% of the variance on both measures. Importantly, it was possible to isolate participants' nationality from potential translation issues, which classically constitute a major limitation.

CONCLUSIONS

Overall, these findings highlight the need for important methodological shifts to better represent social cognition in both fundamental research and clinical practice, especially within emerging international networks and consortia. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Cognitive functioning following traumatic brain injury in older adults: associations with social participation and health-related quality of life

OBJECTIVES

To describe objective and subjective cognitive functioning older adults who sustained TBI at age 65 or over, and to determine whether cognitive functioning is associated with health-related quality of life (HRQoL) and social participation.

METHOD

The sample consisted of 40 individuals with TBI (mean age = 73 years; 65% mild, 35% moderate/severe TBI). On average 15 months post-injury, they completed measures of objective and subjective cognitive functioning (Telephone Interview for Cognitive Status-Modified, Alphaflex, Medical Outcomes Study Cognitive Functioning Scale), HRQoL (SF-12), and social participation (Participation Assessment with Recombined Tools - Objective).

RESULTS

Mean score for objective cognitive functioning was lower than normative values, while mean scores for executive functioning and subjective cognitive functioning were comparable to normative values. There was no relationship between objective and subjective measures. Subjective cognitive functioning and (to a lesser extent) global objective cognitive functioning were significantly associated with mental HRQoL but not with physical HRQoL or social participation.

CONCLUSION

These results underscore the importance of considering both subjective perception and objective performance when assessing and intervening on cognition to promote better mental HRQoL in older adults with TBI.

Factors associated with late-life psychosis in primary care older adults without a diagnosis of dementia

PURPOSE

The epidemiology of late-life psychosis (LLP) remains unclear comparatively to early-onset psychosis. The study aims to estimate the prevalence and incidence of LLP over a 3-year period and examine the correlates of LLP in community-living older adults aged ≥ 65 years recruited in primary care.

METHODS

Study sample included N = 1481 primary care older adults participating in the Étude sur la Santé des Aînés (ESA)-Services study. Diagnoses were obtained from health administrative and self-reported data in the 3 years prior and following baseline interview. The prevalence and incidence of LLP (number of cases) were identified in the 3-year period following interview. Participants with dementia or psychosis related to dementia were excluded. Logistic regressions were used to ascertain the correlates of LLP as function of various individual and health system factors.

RESULTS

The 3-year prevalence and incidence of LLP was 4.7% (95% CI = 3.64-5.81) and 2.8% (95% CI = 1.99-3.68), respectively. Factors associated with both prevalent and incident LLP included functional status, number of physical diseases, hospitalizations, continuity of care and physical activity. Older age and the presence of suicidal ideation were associated with incident LLP, while higher education, a depressive disorder and a history of sexual assault were associated with persistent cases.

CONCLUSIONS

Results highlight the importance of LLP in primary care older adult patients without dementia. Health system factors were consistent determinants of prevalent and incident LLP, suggesting the need for better continuity of care in at-risk primary care older adults.

Videoconference version of the Montreal Cognitive Assessment: normative data for Quebec-French people aged 50 years and older

Background

The COVID-19 pandemic forced health professionals to rapidly develop and implement telepractice and remote assessments. Recent reviews appear to confirm the validity of a wide range of neuropsychological tests for teleneuropsychology and among these, the Montreal Cognitive Assessment (MoCA), a cognitive screening test widely used in clinical settings. The normative data specific to the context of videoconference administration is essential, particularly that consider sociodemographic characteristics.

Aims

This study had for objective to develop French-Quebec normative data for videoconference-administration of the MoCA that consider sociodemographic characteristics.

Methods

A total of 230 community-dwelling adults aged 50 years and older taking part in clinical trials completed the MoCA by videoconference. Regression analyses were run with sex, education, and age as predictors of the total MoCA scores, based on previously published norms. As an exploratory analysis, a second regression analysis was also run with cardiovascular disease as a predictor.

Results

Regression analyses revealed that older age and lower education were associated with poorer total MoCA scores, for medium effect size (p < 0.001, R² = 0.17). Neither sex nor cardiovascular disease, were significant predictors in our analyses. For clinicians, a regression equation was proposed to calculate Z scores.

Discussion

This study provides normative data for the MoCA administered via videoconference in Quebec-French individuals aged 50 years and over.

Conclusions

The present normative data will not only allow clinicians to continue to perform assessments remotely in this pandemic period but will also allow them to perform cognitive assessments to patients located in remote areas.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-022-02092-1.

Body mass index and cognitive decline among community-living older adults: the modifying effect of physical activity

Objective

To examine the associations between BMI categories and subsequent 3-year cognitive decline among older adults, and to test whether physical activity modifies the associations.

Methods

Study sample included n = 1028 cognitively unimpaired older adults participating in the Étude sur la Santé des Aînés (ESA)-Services longitudinal study and followed 3 years later. Cognitive decline was defined as a decrease of > 3 points in MMSE scores between baseline and follow-up. BMI categories (normal weight (reference), underweight, overweight, obese) were derived from self-reported weight and height. Moderate to vigorous physical activity of ≥20 min (# of times per week) was self-reported. The presence of chronic disorders was ascertained from administrative and self-reported data. Logistic regression analyses were used to study the risk of cognitive decline associated with BMI categories stratified by weekly physical activity (≥140 min), the presence of metabolic, cardiovascular and anxio-depressive disorders.

Results

In the overall sample, there was no evidence that underweight, overweight, or obesity, as compared to normal weight, was associated with cognitive decline, after adjusting for sociodemographic, lifestyle factors, and comorbidities. Individuals with overweight reporting high physical activity had lower odds of cognitive decline (OR = 0.25, 95% CI = 0.07–0.89), whereas no association was observed in individuals with overweight reporting low physical activity (OR = 0.85, 95% CI = 0.41–1.75). Among participants with metabolic and cardiovascular disorders, individuals with overweight reporting high physical activity had lower odds of cognitive decline (OR = 0.09, 95% CI = 0.01–0.59 and OR = 0.03, 95% CI = 0.01–0.92 respectively), whereas no association was observed in those with low physical activity.

Conclusion

Physical activity modifies the association between overweight and cognitive decline in older adults overall, as in those with metabolic and cardiovascular disorders. Results highlight the importance of promoting and encouraging regular physical activity in older adults with overweight as prevention against cognitive decline.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11556-022-00284-2.

Birth Cohorts and Cognitive Reserve Influence Cognitive Performances in Older Adults

BACKGROUND

Evidence suggests birth cohort differences in cognitive performance of older adults. Proxies of cognitive reserve (CR), such as educational attainment and occupational complexity, could also partly account for these differences as they are influenced by the sociocultural environment of the birth cohorts.

OBJECTIVE

To predict cognitive performance using birth cohorts and CR and examine the moderating influence of CR on cognitive performance and structural brain health association.

METHODS

Using ADNI data (n = 1628), four birth cohorts were defined (1915-1928; 1929-1938; 1939-1945; 1946-1964). CR proxies were education, occupational complexity, and verbal IQ. We predicted baseline cognitive performances (verbal episodic memory; language and semantic memory; attention capacities; executive functions) using multiple linear regressions with CR, birth cohorts, age, structural brain health (total brain volume; total white matter hyperintensities volume) and vascular risk factors burden as predictors. Sex and CR interactions were also explored.

RESULTS

Recent birth cohorts, higher CR, and healthier brain structures predicted better performance in verbal episodic memory, language and semantic memory, and attention capacities, with large effect sizes. Better performance in executive functions was predicted by a higher CR and a larger total brain volume, with a small effect size. With equal score of CR, women outperformed men in verbal episodic memory and language and semantic memory in all cohorts. Higher level of CR predicted better performance in verbal episodic memory, only when total brain volume was lower.

CONCLUSION

Cohort differences in cognitive performance favor more recent birth cohorts and suggests that this association may be partly explained by proxies of CR.

The Importance of Being Familiar: The Role of Semantic Knowledge in the Activation of Emotions and Factual Knowledge from Music in the Semantic Variant of Primary Progressive Aphasia

BACKGROUND

The role of semantic knowledge in emotion recognition remains poorly understood. The semantic variant of primary progressive aphasia (svPPA) is a degenerative disorder characterized by progressive loss of semantic knowledge, while other cognitive abilities remain spared, at least in the early stages of the disease. The syndrome is therefore a reliable clinical model of semantic impairment allowing for testing the propositions made in theoretical models of emotion recognition.

OBJECTIVE

The main goal of this study was to investigate the role of semantic memory in the recognition of basic emotions conveyed by music in individuals with svPPA.

METHODS

The performance of 9 individuals with svPPA was compared to that of 32 control participants in tasks designed to investigate the ability: a) to differentiate between familiar and non-familiar musical excerpts, b) to associate semantic concepts to musical excerpts, and c) to recognize basic emotions conveyed by music.

RESULTS

Results revealed that individuals with svPPA showed preserved abilities to recognize familiar musical excerpts but impaired performance on the two other tasks. Moreover, recognition of basic emotions and association of musical excerpts with semantic concepts was significantly better for familiar than non-familiar musical excerpts in participants with svPPA.

CONCLUSION

Results of this study have important implications for theoretical models of emotion recognition and music processing. They suggest that impairment of semantic memory in svPPA affects both the activation of emotions and factual knowledge from music and that this impairment is modulated by familiarity with musical tunes.

Childhood Socioeconomic Status Does Not Predict Late-Life Cognitive Decline in the 1936 Lothian Birth Cohort

This study examined childhood socioeconomic status (SES) as a predictor of later life cognitive decline. Data came from 519 participants in the Lothian Birth Cohort 1936 (LBC1936) study. SES measures at 11 years of age included parental educational attainment, father's occupational status, household characteristics and a composite measure of global childhood SES (i.e., a total of low SES childhood indicators). Cognitive abilities were assessed by the Mini-Mental State Exam at ages 69.8, 72.8 and 76.7 years. Most indicators of low childhood SES (i.e., father manual worker, less than secondary school father education, household overcrowding, exterior located toilet, and global childhood SES) did not predict cognitive decline between the ages of 69.8 and 76.7. Participants with less educated mothers showed an increase in cognitive decline (β = -0.132, p = 0.048, and CI = -0.80, -0.00). The relationship between maternal educational attainment and cognitive decline became non-significant when controlling for adult SES (i.e., participant educational attainment and occupation). Adult SES did not mediate the latter relationship. This study provides new evidence that childhood SES alone is not strongly associated with cognitive decline. New knowledge is critical to improving population health by identifying life span stages in which interventions might be effective in preventing cognitive decline.

Cognitive Profile of the Logopenic Variant of Primary Progressive Aphasia Using the Dépistage Cognitif de Québec

BACKGROUND/AIMS

The logopenic variant of primary progressive aphasia (lvPPA) is characterized by impaired word-finding and sentence repetition with phonologic errors but spared motor speech and grammar and semantic knowledge. Although its language deficits have been well studied, the full spectrum of cognitive changes in the lvPPA remains to be defined. We aimed to explore the neurocognitive profile of the lvPPA using a newly developed cognitive screening tool for atypical dementias, the Dépistage Cognitif de Québec (DCQ).

METHODS

We compared 29 patients with lvPPA to 72 amnestic variant Alzheimer disease (aAD) to 438 healthy control (HC) participants. Performance on the 5 indexes of the DCQ (Memory, Visuospatial, Executive, Language and Behavioral) was compared between the 3 groups.

RESULTS

Results showed a significantly lower performance for lvPPA participants in all neurocognitive domains, when compared to HC. When compared to aAD, lvPPA participants had significantly lower scores for language, executive, and visuospatial abilities, but not for memory and behavior.

CONCLUSION

Altogether, these findings better define the neurocognitive changes of lvPPA.

TDQ-30-A New Color Picture-Naming Test for the Diagnostic of Mild Anomia: Validation and Normative Data in Quebec French Adults and Elderly

OBJECTIVE

A reduction in lexical access is observed in normal aging and a few studies also showed that this ability is affected in individuals with subjective cognitive decline. Lexical access is also affected very early in mild cognitive impairment as well as in major neurocognitive disorders. The detection of word-finding difficulties in the earliest stages of pathological aging is particularly difficult because symptoms are often subtle or mild. Therefore, mild anomia is underdiagnosed, mainly due to the lack of sensitivity of naming tests. In this article, we present the TDQ-30, a new picture-naming test designed to detect mild word-finding deficits in adults and elderly people.

METHOD

The article comprises three studies aiming at the development of the test (Study 1), the establishment of its validity and reliability (Study 2), and finally, the production of normative data for French-speaking adults and elderly people from Quebec (Study 3).

RESULTS

The results showed that the TDQ-30 has good convergent validity. Also, the TDQ-30 distinguished the performance of healthy controls from those of participants with mild cognitive impairment, Alzheimer's disease, and post-stroke aphasia. This suggests good discriminant validity. Finally, this study provides normative data computed from a study sample composed of 227 participants aged 50 years and over.

CONCLUSIONS

The TDQ-30 has the potential to become a valuable picture-naming test for the diagnosis of mild anomia associated with pathological aging.

A quadratic function of activation in individuals at risk of Alzheimer's disease

INTRODUCTION

Brain activation is hypothesized to form an inverse U-shape in prodromal Alzheimer's disease (AD), with hyperactivation in the early phase, followed by hypoactivation.

METHODS

Using task-related functional magnetic resonance imaging (fMRI), we tested the inverse U-shape hypothesis with polynomial regressions and between-group comparisons in individuals with subjective cognitive decline plus (SCD+; smaller hippocampal volumes compared to a group of healthy controls without SCD and/or apolipoprotein E [APOE] ε4 allele) or mild cognitive impairment (MCI).

RESULTS

A quadratic function modeled the relationship between proxies of disease severity (neurodegeneration, memory performance) and left superior parietal activation. Linear negative functions modeled the relationship between neurodegeneration and left hippocampal/right inferior temporal activation. Group comparison indicated presence of hyperactivation in SCD+ and hypoactivation in MCI in the left superior parietal lobule, relative to healthy controls.

DISCUSSION

These findings support the presence of an inverse U-shape model of activation and suggest that hyperactivation might represent a biomarker of the early AD stages.

Normative Data for a Tablet-Based Dual-Task Assessment in Healthy Older Adults

OBJECTIVE

The objective of this study is to provide normative data for a tablet-based dual-task assessment in older adults without cognitive deficits.

METHOD

In total, 264 participants aged between 60 and 90 years, French and English-speaking, were asked to perform two discrimination tasks, alone and concurrently. The participants had to answer as fast as possible to one or two images appearing in the center of the tablet by pressing to the corresponding buttons. Normative data are provided for reaction time (RT), coefficient of variation, and accuracy. Analyses of variance were performed by trial types (single-pure, single-mixed, dual-mixed), and linear regressions assessed the relationship between performance and sociodemographic characteristics.

RESULTS

The participants were highly educated and a large proportion of them were women (73.9%). The accuracy on the task was very high across all blocks. RT data revealed both a task-set cost and a dual-task cost between the blocks. Age was associated with slower RT and with higher coefficient of variability. Men were significantly slower on dual-mixed trials, but their coefficient of variability was lower on single-pure trials. Education was not associated with performance.

CONCLUSIONS

This study provides normative data for a tablet-based dual-task assessment in older adults without cognitive impairment, which was lacking. All participants completed the task with good accuracy in less than 15 minutes and thus, the task is transferable to clinical and research settings.

Validation of the Dépistage Cognitif de Québec in the Oldest Old

OBJECTIVE

We aimed to validate the Dépistage Cognitif de Québec (DCQ; www.dcqtest.org), a new cognitive screening tool for atypical degenerative syndromes, in the oldest old.

METHODS

The DCQ was developed by expert behavioural neurologists and clinical neuropsychologists based on updated criteria for Alzheimer's disease, primary progressive aphasia, and behavioural variant frontotemporal dementia. It targets five relevant cognitive domains: Memory, Visuospatial, Executive, Language, and Behaviour. Validation was performed using a prospective community-based sample consisting of 53 healthy French-speaking Canadian volunteers aged between 80 and 94 years old. Normative data were derived from participants with no history of cognitive difficulties and a Montreal Cognitive Assessment (MoCA) score ≥ 24.

RESULTS

The mean DCQ total score (out of 100) was 84.65 (SD = 6.33). Pearson's correlation coefficient showed a moderate, but significant, correlation (r = 0.36, p < .01) with the MoCA. Normative data shown in percentiles were stratified by age and education for DCQ total score and for each of the five cognitive domains.

CONCLUSIONS

This study suggests that the DCQ is a valid cognitive screening test in the oldest old. It is proposed that the DCQ can help early identification of atypical degenerative syndromes.

Evaluation of the Effects of an Intervention Intended to Optimize the Sleep Environment Among the Elderly: An Exploratory Study

Purpose

The objective of this exploratory study was to evaluate the effects of a brief intervention intended to optimize the sleep environment in older people living in the community and to examine the way these effects change over time.

Methods

The sample was made up of 44 participants (19 men and 25 women) aged 65-85 years, with a mean age of 71.4. The intervention consisted in a group training session that covered the reasons for and ways to ("why" and "how") optimize a sleep environment. It comprises six themes: air quality and odors, luminosity, noises and sounds, comfort of the mattress, comfort of the pillow, and temperature. Participants completed a set of questionnaires before the intervention, and one month and four months later.

Results

Four months after the intervention, the replies to the questionnaires showed that the participants experienced reduced severity of insomnia, sleep latency and anxiety. The subjective quality of the participants' sleep along with their sleep efficacy also increased significantly during the same period.

Conclusion

A brief intervention intended to optimize the sleep environment appears promising as an addition or alternative to the two other sleep improvement options generally offered to older people: medication and cognitive behavioral therapy.

Efficacy of cognitive-behavioural therapy interventions on reducing burden for caregivers of older adults with a neurocognitive disorder: a systematic review and meta-analysis

By 2025, 34 million people worldwide will be living with Alzheimer's disease or another form of dementia (i.e., neurocognitive disorders). Symptoms of neurocognitive disorders have functional repercussions on daily activities. People with neurocognitive disorders often rely on a caregiver to alleviate the impact of their symptoms, but this help has consequences for the caregiver. Indeed, caregivers report subjective burden, depressive symptoms, stress, anxiety and a lower quality of life than non-caregivers. Multiple cognitive-behavioral therapy (CBT) trials have been conducted to reduce these symptoms for caregivers. No meta-analysis has been conducted to evaluate the efficacy of this type of intervention on reducing subjective burden. Articles were selected from PsycNet, MEDLINE, AgeLine and ProQuest Dissertation and Theses for the period from 2000 to 2017. Article selection, data extraction and bias analysis for individual studies were completed by two independent authors who used a consensus procedure when discrepancies occurred. A total of 20 articles were included in the systematic review. Ten studies evaluated the efficacy of CBT in reducing subjective burden, and the meta-analysis suggested a significant reduction in subjective burden following CBT. Additionally, 17 studies evaluated the efficacy in reducing depressive symptoms, and the meta-analysis revealed a significant reduction for these caregivers following CBT. CBT for caregivers of individuals with a neurocognitive disorder had no impact on stress, anxiety, or quality of life.

User-Centered Design and Evaluation of a Web-Based Decision Aid for Older Adults Living With Mild Cognitive Impairment and Their Health Care Providers: Mixed Methods Study

Background

Mild cognitive impairment (MCI) is often considered a transitional state between normal and pathologic (eg, dementia) cognitive aging. Although its prognosis varies largely, the diagnosis carries the risk of causing uncertainty and overtreatment of older adults with MCI who may never progress to dementia. Decision aids help people become better informed and more involved in decision making by providing evidence-based information about options and possible outcomes and by assisting them in clarifying their personal values in relation to the decision to be made.

Objective

This study aimed to incorporate features that best support values clarification and adjust the level of detail of a web-based decision aid for individuals with MCI.

Methods

We conducted a rapid review to identify options to maintain or improve cognitive functions in individuals with MCI. The evidence was structured into a novel web-based decision aid designed in collaboration with digital specialists and graphic designers. Qualitative and user-centered evaluations were used to draw on users’ knowledge, clarify values, and inform potential adoption in routine clinical practice. We invited clinicians, older adults with MCI, and their caregivers to evaluate the decision aid in 6 consecutive rounds, with new participants in each round. Quantitative data were collected using the Values Clarity and Informed subscales of the Decisional Conflict Scale, the System Usability Scale, the Ottawa Acceptability questionnaire, and a 5-point satisfaction rating scale. We verified their comprehension using a teach-back method and recorded usability issues. We recorded the audio and computer screen during the session. An inductive thematic qualitative analysis approach was used to identify and describe the issues that arose. After each round, an expert panel met to prioritize and find solutions to mitigate the issues. An integrated analysis was conducted to confirm our choices.

Results

A total of 7 clinicians (social workers, nurses, family physicians, psychologists) and 12 older (≥60 years) community-dwelling individuals with MCI, half of them women, with education levels going from none to university diploma, were recruited and completed testing. The thematic analysis revealed 3 major issues. First, the user should be guided through the decision-making process by tailoring the presentation of options to users’ priorities using the values clarification exercise. Second, its content should be simple, but not simplistic, notably by using information layering, plain language, and pictograms. Third, the interface should be intuitive and user friendly, utilize pop-up windows and information tips, avoid drop-down menus, and limit the need to scroll down. The quantitative assessments corroborated the qualitative findings.

Conclusions

This project resulted in a promising web-based decision aid that can support decision making for MCI intervention, based on the personal values and preferences of the users. Further ongoing research will allow its implementation to be tested in clinical settings.

Evidence of a Relation Between Hippocampal Volume, White Matter Hyperintensities, and Cognition in Subjective Cognitive Decline and Mild Cognitive Impairment

OBJECTIVE

The concepts of mild cognitive impairment (MCI) and subjective cognitive decline (SCD) have been proposed to identify individuals in the early stages of Alzheimer's disease (AD), or other neurodegenerative diseases. One approach to validate these concepts is to investigate the relationship between pathological brain markers and cognition in those individuals.

METHOD

We included 126 participants from the Consortium for the Early Identification of Alzheimer's disease-Quebec (CIMA-Q) cohort (67 SCD, 29 MCI, and 30 cognitively healthy controls [CH]). All participants underwent a complete cognitive assessment and structural magnetic resonance imaging. Group comparisons were done using cognitive data, and then correlated with hippocampal volumes and white matter hyperintensities (WMHs).

RESULTS

Significant differences were found between participants with MCI and CH on episodic and executive tasks, but no differences were found when comparing SCD and CH. Scores on episodic memory tests correlated with hippocampal volumes in both MCI and SCD, whereas performance on executive tests correlated with WMH in all of our groups.

DISCUSSION

As expected, the SCD group was shown to be cognitively healthy on tasks where MCI participants showed impairment. However, SCD's hippocampal volume related to episodic memory performances, and WMH to executive functions. Thus, SCD represents a valid research concept and should be used, alongside MCI, to better understand the preclinical/prodromal phase of AD.

Cognitive decline and alcohol consumption adjusting for functional status over a 3-year period in French speaking community living older adults

BACKGROUND

The effect of alcohol consumption on cognitive decline is not clear. We aimed to study the association between alcohol consumption and cognitive functioning controlling for functional heath status.

METHODS

A total of 1610 older adults with a score ≥26 on the Mini-Mental State Examination (MMSE) were followed to assess the change in scores at the 3-year follow-up. Information on alcohol consumption as well as socio-demographic, lifestyle, psychosocial and clinical factors, as well as health service use were assessed at baseline and 3-year follow-up interviews. Linear mixed models with repeated measures were used stratifying by functional status.

RESULTS

Close to 73% reported consuming alcohol in the past 6 months, of which 11% were heavy drinkers (≥11 and ≥16 drinks for women and men). A significant decrease in MMSE scores was observed in low functioning non-drinkers (-1.48; 95% CI: -2.06, -0.89) and light to moderate drinkers (-0.99; 95% CI: -1.54, -0.44) and high functioning non-drinkers (-0.51; 95% CI: -0.91, -0.10).

CONCLUSIONS

Alcohol consumption did not contribute to cognitive decline. Cognitive decline was greater in individuals reporting low functional status. Research should focus on the interaction between changing patterns of alcohol consumption and social participation in individuals with low and high functioning status.

Behavioral and Psychological Symptoms that Predict Cognitive Decline or Impairment in Cognitively Normal Middle-Aged or Older Adults: a Meta-Analysis

Epidemiological studies have revealed that behavioral and psychological (or non-cognitive) symptoms are risk factors for cognitive decline in older adults. This study aimed to systematically review the literature and determine which behavioral and psychological symptoms are most predictive of future cognitive decline among individuals with no pre-existing cognitive impairments. The selected studies included middle-aged or older adults without cognitive impairments. The predictors were assessed using behavioral and psychological questionnaires, or diagnostic interviews, to identify non-cognitive symptoms or psychiatric clinical conditions. The follow-up period was at least one year, and the design of the selected studies was either retrospective or prospective. This study compared individuals with and without non-cognitive manifestations and resulted in one of three outcomes: (a) a score change on a cognitive measure, (b) a diagnosis of mild cognitive impairment, or (c) a diagnosis of Alzheimer's disease or dementia. Four online databases were searched for eligible studies from the database inception to January 17, 2017: MEDLINE (PubMed), Embase (OVID), PsycINFO, and Web of Science. Pooled effect sizes were estimated using a random-effect model. Higgins I², the Q statistic, and tau-squared were used to quantify the observed heterogeneity between the studies. Results indicate that depression and sleep duration (long and short) were the most consistent associations between behavioral or psychological symptoms and cognitive decline. This meta-analysis supports the need to assess behavioral and psychological symptoms in cognitively intact older adults to identify those who are at risk for cognitive decline.

Polyphenols From Grape and Blueberry Improve Episodic Memory in Healthy Elderly with Lower Level of Memory Performance: A Bicentric Double-Blind, Randomized, Placebo-Controlled Clinical Study

Polyphenols are promising nutritional bioactives exhibiting beneficial effect on age-related cognitive decline. This study evaluated the effect of a polyphenol-rich extract from grape and blueberry (PEGB) on memory of healthy elderly subjects (60-70 years-old). A bicentric, randomized, double-blind, placebo-controlled trial was conducted with 215 volunteers receiving 600 mg/day of PEGB (containing 258 mg flavonoids) or a placebo for 6 months. The primary outcome was the CANTAB Paired Associate Learning (PAL), a visuospatial learning and episodic memory test. Secondary outcomes included verbal episodic and recognition memory (VRM) and working memory (SSP). There was no significant effect of PEGB on the PAL on the whole cohort. Yet, PEGB supplementation improved VRM-free recall. Stratifying the cohort in quartiles based on PAL at baseline revealed a subgroup with advanced cognitive decline (decliners) who responded positively to the PEGB. In this group, PEGB consumption was also associated with a better VRM-delayed recognition. In addition to a lower polyphenol consumption, the urine metabolomic profile of decliners revealed that they excreted more metabolites. Urinary concentrations of specific flavan-3-ols metabolites were associated, at the end of the intervention, with the memory improvements. Our study demonstrates that PEGB improves age-related episodic memory decline in individuals with the highest cognitive impairments.

Psychological predictors of benzodiazepine discontinuation among older adults: Results from the PASSE 60

BACKGROUND

Long-term benzodiazepine (BZD) use among seniors is mostly inappropriate and associated with adverse health outcomes. To prevent these consequences, withdrawal is crucial, yet knowledge is limited about what predicts BZD discontinuation. Until now, most studies have focused on sociodemographic and BZD intake factors as predictors while neglecting psychological factors. This research addresses this issue by studying how the intensity of depressive symptoms, social support satisfaction, self-perceived competence in the ability to withdraw, and overall quality of sleep predict discontinuation in long-term older consumers.

METHOD

Seventy-three participants aged 60 years and older were enrolled in this study. There were four time measures: before discontinuation (T1), after (T2), 3 months after (T3), and 12 months after (T4). Data were collected in the "Programme d'Aide du Succès au SEvrage" (PASSE-60+) study.

RESULTS

Social support satisfaction predicted discontinuation at T2 and T4. Self-perceived competence in the ability to withdraw and depressive symptoms predicted discontinuation at T4. This later prediction was counterintuitive; higher depressive symptoms at T1 were linked with higher discontinuation success. BZD intake factors (length of use and dose) were good predictors for short term discontinuation. Psychological factors were moderate predictors for short term and good predictors for long term discontinuation.

CONCLUSION

Psychological factors are good predictors of discontinuation and are better predictors than BZD intake factors of long-term discontinuation. Discontinuation programs should focus on social support and self-perceived competence to improve their efficacy. Further studies are needed to acquire a more complete picture of the psychological predictors of discontinuation success. ClinicalTrials.gov Identifier: NCT02281175.

Caregivers' emotional distress due to neuropsychiatric symptoms of persons with amnestic mild cognitive impairment or Alzheimer's disease

Compared to the literature on Alzheimer's disease (AD), less is known about the emotional distress of caregivers of persons with amnestic Mild Cognitive Impairment (aMCI). This study describes and compares emotional distress due to neuropsychiatric symptoms (NPS) among children and spousal caregivers of aMCI or mild AD care recipients. It also examined the association between the frequency and severity of NPS and caregivers' emotional distress. In total, 108 spouses or children of persons with aMCI or mild AD were administered the Neuropsychiatric Inventory, measuring the frequency/severity of NPS in the patient as well as the associated caregiver's emotional distress. Emotional distress due to each NPS was compared between children and spouses and the relationship between NPS and emotional distress was assessed. There was no significant difference in emotional distress between aMCI and mild AD spousal caregivers for all symptoms, but for children caregivers, emotional distress was significantly higher in the mild AD group than in the aMCI group. Regardless of the caregiver's relationship to the patient or the condition (aMCI vs mild AD) of the latter, there was a positive relationship between the frequency/severity of NPS and caregiver emotional distress. Caregivers of persons with aMCI experienced emotional distress due to the presence of NPS in their significant others at a level that is generally similar to that experienced by caregivers of persons with mild AD. This study highlights the need for interventions to reduce emotional burden by helping caregivers manage NPS in care recipients.

The Consortium for the early identification of Alzheimer's disease-Quebec (CIMA-Q)

Introduction

The Consortium for the early identification of Alzheimer's disease–Quebec (CIMA-Q) created a research infrastructure to recruit, characterize, and track disease progression in individuals at risk of dementia.

Methods

CIMA-Q established standardized clinical, neuropsychological, neuroimaging, blood (plasma, serum, RNA, genomic DNA), cryopreserved peripheral blood mononuclear cells, and cerebrospinal fluid collection protocols. These data and biological materials are available to the research community.

Results

In phase 1, 115 persons with subjective cognitive decline, 88 with mild cognitive impairment, 31 with early probable Alzheimer's disease, and 56 older adults with no worries nor impairments received detailed clinical and cognitive evaluations as well as blood and peripheral blood mononuclear cells collections. Among them, 142 underwent magnetic resonance imaging, 29 a ¹⁸fluorodeoxyglucose positron emission tomography, and 60 a lumbar puncture.

Discussion

CIMA-Q provides procedures and resources to identify early biomarkers and novel therapeutic targets, and holds promise for detecting cognitive decline in Alzheimer's disease.

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Well-ascertained cohort of 290 community-dwelling elderly individuals in Quebec.

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Large number of individuals with subjective cognitive decline studied longitudinally.

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Clinical, neuropsychology, neuroimaging, and biomaterials available for Alzheimer's disease studies.