Verbal and spatial memory spans in mild cognitive impairment

The effects of exergames for cognitive function in older adults with mild cognitive impairment: a systematic review and metaanalysis

Purpose

Exergames are an innovative method that can promote neuroplasticity and improve the cognitive abilities of the elderly. This study aimed to compare the effects of single-task and multi-task exergames on the cognitive ability of the elderly with mild cognitive impairment (MCI).

Methods

Computerized literature search was performed using PubMed, Web of Science, EBSCO, Elsevier, ProQuest, China National Knowledge Infrastructure (CNKI), Wanfang and VIP database to identify relevant articles from the establishment of the database from inception to April 1, 2024. The inclusion criteria were: (i) participants aged 60 or older diagnosed with mild cognitive impairment, regardless of gender; (ii) use of randomized controlled trials (RCTs); (iii) interventions involving exergames with physical activity or as the primary variable; and (iv) outcome measures using standardized neuropsychological instruments to assess cognitive function, including statistical data on sample size, mean, and standard deviation. Finally, the included study comprised a total of 526 participants. Mean difference (MD) and 95% confidence interval (CI) were used to synthesize the effect size in the data.

Results

11 studies were included. Due to the differences in the intervention methods, subgroup analysis was performed on the included research. Compared with the control group assessed by the Montreal Cognitive Assessment Scale, the single-task intervention improved the cognitive ability of the elderly with MCI (MD 3.40, 95% CI 2.43-4.37), the Mini-Mental State Examination Scale (MD 2.38, 95% CI -2.03 to 2.72), the Trail Making Test (MD -3.89, 95% CI -6.45 to -1.33), and the Digit Span Forward test (MD 1.16, 95% CI 0.73-1.60).

Conclusion

This meta-analysis supports that exergames could be an effective cognitive rehabilitation method for MCI patients. Our study recommends that patients implement a customized exergames program and adhere to it for a long time. It is necessary to pay attention to the exercise guidelines and provide evidence from clinicians.

Strengths and limitations of this study

(1) This meta-analysis supports that exergames could be an effective cognitive rehabilitation method for MCI patients. Our study recommends that patients implement a customized exergames program and adhere to it for a long time. It is necessary to pay attention to the exercise guidelines and provide evidence from clinicians. (2) This research provides preliminary evidence for the clinical utility of VR tasks developed for mild cognitive impairment. (3) In this paper, only relevant studies in Chinese and English were searched, and no studies in other languages were searched.

Subjective clustering in patients with fronto-temporal dementia

In the behavioral variant of frontotemporal dementia (bvFTD) memory deficits have been traditionally considered as due to difficulties in encoding/retrieval frontal strategies. However, the frontal origin of memory deficits in bvFTD has been questioned and hippocampal dysfunction has been also proposed. Here we analyzed bvFTD patients' proficiency in subjectively organizing memories without an external criterion. Twenty bvFTD patients and 20 healthy individuals were assessed with memory and executive tasks. The ability to subjectively organize memories in the immediate recall of a 15 unrelated word list was measured by calculating the index of subjective clustering (ISC) based on the constancies in response order across the five consecutive free recall trials. Results revealed reduced ISC in bvFTD patients with respect to normal controls. In the bvFTD group, the ISC score correlated with the Corsi span backward score and the number of categories achieved on the Modified Card Sorting Test. The bvFTD patients' reduced ISC and its correlation with executive performance suggest that executive deficits underlie their defective strategic organization of memories. However, as ISC did not predict memory accuracy in these patients, the memory deficit may not be the mere expression of their executive difficulties.

Assessment of Language Function in Older Mandarin-Speaking Adults with Mild Cognitive Impairment using Multifaceted Language Tests

BACKGROUND

Individuals with amnestic mild cognitive impairment (aMCI), especially for those with multidomain cognitive deficits, should be clinically examined for determining risk of developing Alzheimer's disease. English-speakers with aMCI exhibit language impairments mostly at the lexical-semantic level. Given that the language processing of Mandarin Chinese is different from that of alphabetic languages, whether previous findings for English-speakers with aMCI can be generalized to Mandarin Chinese speakers with aMCI remains unclear.

OBJECTIVE

This study examined the multifaceted language functions of Mandarin Chinese speakers with aMCI and compared them with those without cognitive impairment by using a newly developed language test battery.

METHODS

Twenty-three individuals with aMCI and 29 individuals without cognitive impairment were recruited. The new language test battery comprises five language domains (oral production, auditory and reading comprehension, reading aloud, repetition, and writing).

RESULTS

Compared with the controls, the individuals with aMCI exhibited poorer performance in the oral production and auditory and reading comprehension domains, especially on tests involving effortful lexical and semantic processing. Moreover, the aMCI group made more semantic naming errors compared with their counterparts and tended to experience difficulty in processing items belonging to the categories of living objects.

CONCLUSIONS

The pattern identified in the present study is similar to that of English-speaking individuals with aMCI across multiple language domains. Incorporating language tests involving lexical and semantic processing into clinical practice is essential and can help identify early language dysfunction in Mandarin Chinese speakers with aMCI.

Delayed primacy recall performance predicts post mortem Alzheimer's disease pathology from unimpaired ante mortem cognitive baseline

We propose a novel method to assess delayed primacy in the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) memory test. We then examine whether this measure predicts post mortem Alzheimer's disease (AD) neuropathology in individuals who were clinically unimpaired at baseline. A total of 1096 individuals were selected from the Rush Alzheimer's Disease Center database registry. All participants were clinically unimpaired at baseline, and had subsequently undergone brain autopsy. Average age at baseline was 78.8 (6.92). A Bayesian regression analysis was carried out with global pathology as an outcome; demographic, clinical, and apolipoprotein E (APOE) data as covariates; and cognitive predictors, including delayed primacy. Global AD pathology was best predicted by delayed primacy. Secondary analyses showed that delayed primacy was mostly associated with neuritic plaques, whereas total delayed recall was associated with neurofibrillary tangles. Sex differential associations were observed. We conclude that CERAD-derived delayed primacy is a useful metric for early detection and diagnosis of AD in unimpaired individuals.

Highlights

We propose a novel method to analyse serial position in the CERAD memory test.We analyse data from 1096 individuals who were cognitively unimpaired at baseline.Delayed primacy predicts post mortem pathology better than traditional metrics.

Prefrontal hemodynamic features of older adults with preserved visuospatial working memory function

Memory decline has been observed in the aging population and is a risk factor for the later development of dementia. Understanding how memory is preserved in older adults has been an important topic. The present study examines the hemodynamic features of older adults whose memory is comparable with that of young adults. In the present study, 45 younger and 45 older adults performed the visual memory task with various difficulty levels (i.e., the items to be remembered), and their cerebral hemodynamics at each level were measured by functional near-infrared spectroscopy (fNIRS). The results showed that older adults exhibited higher activation than younger adults under more difficult but not easier levels. In addition, older adults whose performance is comparable with that of young adults (i.e., being able to remember six items) showed more right-lateralized activation. However, those unable to do so showed more left-lateralized activation. The results suggested that high-performing older adults possess successful compensatory mechanisms by recruiting cognitive resources in a specialized brain region.

"Life's Essential 8" Cardiovascular Health and Dementia Risk, Cognition, and Neuroimaging Markers of Brain Health

OBJECTIVE

To evaluate associations of Life's Essential 8 (LE8) score, the recently updated metric for promoting cardiovascular health (CVH), with the risk of incident dementia and its subtypes, cognition, and neuroimaging outcomes and to determine whether these associations differ among apolipoprotein E (APOE)-ε4 genotypes.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

A total of 316,669 participants [mean (SD) age, 56.3 (8.1) years] without prior cardiovascular disease or dementia from the UK Biobank study at baseline survey (2006-2010) were enrolled.

METHODS

A modified version of the LE8 score was created (range: 0-100) and categorized into poor (0-49), intermediate (50-79), and optimal (80-100) CVH. Cox proportional hazard and multivariable linear regression models were used.

RESULTS

During a median 12.6 years of follow-up, 4238 all-cause dementia cases including 1797 Alzheimer's disease and 939 vascular dementia (VaD) occurred. Individuals with optimal CVH had 44% (95% CI, 0.48-0.64) lower incident all-cause dementia risk and 71% (95% CI, 0.22-0.38) lower VaD risk compared with those who had poor CVH. A 10-point increment in LE8 was associated with higher fluid intelligence scores (β, 0.088; 95% CI, 0.073-0.102) and numeric memory scores (β, 0.054; 95% CI, 0.043-0.065), and was also associated with lower white matter hyperintensity volume (β, -0.673; 95% CI, -0.751 to -0.596), larger total brain volume (β, 77.93; 95% CI, 62.03-93.84), and hippocampal volume (β, 0.197; 95% CI, 0.106-0.288). In addition, the association between LE8 profiles and dementia diagnosis differed by APOE genotype (all P for interaction ≤ .001), and was more evident among APOE-ε4 noncarriers.

CONCLUSIONS AND IMPLICATIONS

Individuals with a higher LE8 score experienced fewer dementia events (driven especially by incident VaD) and were associated with better neurocognitive brain health profiles. CVH optimization may be beneficial to the maintenance of brain health.

A comparison of diagnostic performance of word-list and story recall tests for biomarker-determined Alzheimer's disease

BACKGROUND

Wordlist and story recall tests are routinely employed in clinical practice for dementia diagnosis. In this study, our aim was to establish how well-standard clinical metrics compared to process scores derived from wordlist and story recall tests in predicting biomarker determined Alzheimer's disease, as defined by CSF ptau/Aβ42 ratio.

METHODS

Data from 295 participants (mean age = 65 ± 9.) were drawn from the University of Wisconsin - Madison Alzheimer's Disease Research Center (ADRC) and Wisconsin Registry for Alzheimer's Prevention (WRAP). Rey's Auditory Verbal Learning Test (AVLT; wordlist) and Logical Memory Test (LMT; story) data were used. Bayesian linear regression analyses were carried out with CSF ptau/Aβ42 ratio as outcome. Sensitivity analyses were carried out with logistic regressions to assess diagnosticity.

RESULTS

LMT generally outperformed AVLT. Notably, the best predictors were primacy ratio, a process score indexing loss of information learned early during test administration, and recency ratio, which tracks loss of recently learned information. Sensitivity analyses confirmed this conclusion.

CONCLUSIONS

Our study shows that story recall tests may be better than wordlist tests for detection of dementia, especially when employing process scores alongside conventional clinical scores.

Repeatable battery for the assessment of neuropsychological status and its relationship to biomarkers of Alzheimer's disease

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) has been associated with commonly used biomarkers of Alzheimer's disease (AD). However, prior studies have typically utilized small and poorly characterized samples, and they have not analyzed the subtests of the RBANS. The current study sought to expand on prior work by examining the relationship between the Indexes and subtest scores of the RBANS and three AD biomarkers: amyloid deposition via positron emission tomography, hippocampal volume via magnetic resonance imaging, and APOE ε4 status.

One-hundred twenty-one older adults across the AD continuum (intact, amnestic Mild Cognitive Impairment, mild AD), who were mostly Caucasian and well-educated, underwent assessment with the RBANS and collection of the three biomarkers.

Greater amyloid deposition was significantly related to lower scores on all five Indexes and the Total Scale score of the RBANS, as well as 11 of 12 subtests. For bilateral hippocampal volume, significant correlations were observed for 4 of the 5 Indexes, Total Scale score, and 9 of 12 subtests, with smaller hippocampi being related to lower RBANS scores. Participants with at least one APOE ε4 allele had significantly lower scores on 3 of the 5 Indexes, Total Scale score, and 8 of the 12 subtests.

In this sample of participants across the dementia spectrum, most RBANS Indexes and subtests showed relationships with the amyloid deposition, hippocampal volumes, and APOE status, with poorer performance on the RBANS being associated with biomarker positivity. Although memory scores on the RBANS have traditionally been linked to biomarkers in AD, other Index and subtest scores also hold promise as indicators of AD. Replication in a more diverse sample is needed.

No Common Factor Underlying Decline of Visual Abilities in Mild Cognitive Impairment

INTRODUCTION

Recent work has shown an association between cognitive and visual impairments and two main theories were advanced, namely the sensory deprivation and the common cause theories. Most studies considered only basic visual functions such as visual acuity or visual field size and evaluated the association with dementia.

OBJECTIVES

To reconcile between these theories and to test the link between visual and cognitive decline in mildly cognitive impaired people.

METHODS

We employed a battery of 19 visual tasks on 39 older adults with mild cognitive impairment and 91 without any evidence of cognitive decline, as measured by the Montreal Cognitive Assessment.

RESULTS

Our results show a strong association between visual impairment and mild cognitive impairment. In agreement with previous results with younger and healthy older adults, we found also only weak correlations between most tests in older adults with mild cognitive impairment.

CONCLUSION

Our results suggest that visual and cognitive abilities decline simultaneously, but they do so independently across visual and cognitive functions and across participants.

Environmental manganese exposure and cognitive control in a South African population

OBJECTIVE

To characterize the association between environmental (residential air) manganese (Mn) exposure and cognitive performance, focusing on cognitive control, in a Black African population.

METHODS

We administered the Go-No-Go, Digit Span, and Matrix Reasoning tests to population-based samples age ≥40 from a high Mn (smelter) exposed community, Meyerton (N = 629), and a demographically comparable low (background levels) non-exposed community, Ethembalethu, (N = 96) in Gauteng province, South Africa. We investigated the associations between community and performance on the cognitive tests, using linear regression. We adjusted a priori for age and sex, and examined the effect of adjustment for education, nonverbal IQ, smoking, and alcohol consumption. We measured airborne PM_2.5-Mn to confirm community exposure differences.

RESULTS

Compared to Ethembalethu residents, Meyerton residents' test scores were lower (poorer) for all tests: 0.55 (95 % confidence interval [CI] 0.08, 1.03) lower scores for Matrix Reasoning, 0.34 (95 % CI -0.07, 0.75) lower for Digit Span, and 0.15 (95 % CI 0.09, 0.21) lower for Go-No-Go (high frequency discriminability index [probability]). The latter represented the most marked difference in terms of z-scores (0.50, 95 % CI 0.30, 0.71 standard deviations lower). The mean of the z-score of each of the three tests was also lower (0.34, 95 % CI 0.18, 0.50 standard deviations lower). These associations were similar in men and women, but attenuated with adjustment for education. Differences for Matrix Reasoning and Digit Span between the two communities were observed only among those who had lived in Meyerton ≥10 years, whereas for Go-No-Go, differences were also apparent among those who had lived in Meyerton <10 years. Mean PM_2.5-Mn at a long-term fixed site in Meyerton was 203 ng/m³ and 10 ng/m³ in Ethembalethu.

CONCLUSION

Residence in a community near a high Mn emission source is associated with cognitive dysfunction, including aspects of cognitive control as assessed by the Go-No-Go test.