Predementia constructs: Mild cognitive impairment or mild neurocognitive disorder? A narrative review

Effects of a dual intervention (motor and virtual reality-based cognitive) on cognition in patients with mild cognitive impairment: a single-blind, randomized controlled trial

BACKGROUND

The increase in cases of mild cognitive impairment (MCI) underlines the urgency of finding effective methods to slow its progression. Given the limited effectiveness of current pharmacological options to prevent or treat the early stages of this deterioration, non-pharmacological alternatives are especially relevant.

OBJECTIVE

To assess the effectiveness of a cognitive-motor intervention based on immersive virtual reality (VR) that simulates an activity of daily living (ADL) on cognitive functions and its impact on depression and the ability to perform such activities in patients with MCI.

METHODS

Thirty-four older adults (men, women) with MCI were randomized to the experimental group (n = 17; 75.41 ± 5.76) or control (n = 17; 77.35 ± 6.75) group. Both groups received motor training, through aerobic, balance and resistance activities in group. Subsequently, the experimental group received cognitive training based on VR, while the control group received traditional cognitive training. Cognitive functions, depression, and the ability to perform activities of daily living (ADLs) were assessed using the Spanish versions of the Montreal Cognitive Assessment (MoCA-S), the Short Geriatric Depression Scale (SGDS-S), and the of Instrumental Activities of Daily Living (IADL-S) before and after 6-week intervention (a total of twelve 40-minutes sessions).

RESULTS

Between groups comparison did not reveal significant differences in either cognitive function or geriatric depression. The intragroup effect of cognitive function and geriatric depression was significant in both groups (p < 0.001), with large effect sizes. There was no statistically significant improvement in any of the groups when evaluating their performance in ADLs (control, p = 0.28; experimental, p = 0.46) as expected. The completion rate in the experimental group was higher (82.35%) compared to the control group (70.59%). Likewise, participants in the experimental group reached a higher level of difficulty in the application and needed less time to complete the task at each level.

CONCLUSIONS

The application of a dual intervention, through motor training prior to a cognitive task based on Immersive VR was shown to be a beneficial non-pharmacological strategy to improve cognitive functions and reduce depression in patients with MCI. Similarly, the control group benefited from such dual intervention with statistically significant improvements.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06313931; https://clinicaltrials.gov/study/NCT06313931 .

A novel abbreviated version of the Luria neuropsychological diagnosis battery: reliability and convergent validity in Spanish older adults

OBJECTIVE

To estimate the test-retest and inter-rater reliability of the new Spanish abbreviated version of the Luria Neuropsychological Diagnosis (DNA-2) battery for older adults.

METHOD

A total of thirty cognitively healthy volunteers were examined in this study. The participants completed a comprehensive standardized assessment, encompassing cognitive and functional performance. Intraclass correlation coefficients (ICC) were used to examine test-retest and inter-rater reliability. One month was allowed between administrations. Furthermore, correlations between Luria DNA-2 (total and domain subscores) and other classical cognitive measures were explored.

RESULTS

The test-retest reliability on the overall Luria DNA-2 score was high (ICC= .834, 95% CI [.680, .917], p < .001). Furthermore, the inter-rater reliability for the total score demonstrated an excellent concordance between administrators (ICC= .990, 95% CI [.979, .995], p < .001). Positive and significant correlations were observed between Luria DNA-2 (both total and domain subscores) and the Addenbrooke's Cognitive Examination (ACE-III; ρ = .857, p < .001).

CONCLUSIONS

This study supports the adequate reliability of the Luria DNA-2, as an abbreviated neuropsychological battery, for assessing cognitive performance in Spaniards aged 55 years and older. Future studies should continue to explore the psychometric properties of the Luria DNA-2, particularly those related to its diagnostic validity for early detection of cognitive impairment.

The effects of the interplay between vitamins, antibiotics, and gut microbiota on the pathogenesis and progression of dementia: A systematic review and meta-analysis

Background

Given that there is already evidence of a neural network that connects the brain and gut and that the gut microbiota actively modulates gut health, it is crucial to know which foods, supplements, and medications to use or avoid when treating any disease that causes dementia or cognitive impairment. Previous research has examined the relationships between vitamins, antibiotics, and gut microbiota and the correlations between these factors and dementia. The question arises of how these three factors interact together and if evidence suggests one element is more important than the others in the pathogenesis and development of dementia.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standards were followed when conducting this review. The papers' publication dates varied from (2012-2022). Cochrane/EMBASE, PEDro, and PubMed/Medline databases were searched. The precise terms "gut microbiota," vitamins," antibiotics," and "dementia" were included in the search method, along with the conjunctions "OR" and "AND."

Results

Gut dysbiosis has a significant impact on cognition, brain function, and the development and progression of dementia. The two most popular probiotics used in studies linked to cognition benefits were Lactobacillus and Bifidobacterium. Numerous scales were used to evaluate cognition, but the mini-mental state examination was the most popular, and the most prevalent impairment was Alzheimer's disease. The supplements with the most significant impact on gut microbiota were vitamin B-12 and folic acid.

Conclusion

This systematic review concluded that vitamins, gut microbiota and antibiotics have a close association with the development of dementia. More research is required to establish causality and elucidate the underlying mechanisms because there is still little evidence connecting the interactions of vitamins, medications, and microbiota with dementia. The complexity of interactions between genetics, lifestyle factors, and comorbidities, as well as the heterogeneity of dementia, may make it more challenging to interpret the findings.

The relationship between perceived stigma and perceived stress in cognitive decline: a survey of persons with mild cognitive impairment and their caregivers

Introduction

While Alzheimer's disease and other causes of dementia have rapidly become a global health crisis with growing incidence that is unabated, the incidence of Mild Cognitive Impairment (MCI) far exceeds that of Alzheimer's disease. Persons with MCI demonstrate some level of cognitive impairment, but daily functions remain intact and there is no certainty that they will develop dementia. Yet, the possibility conjures a considerable amount of fear and anxiety, further fueled by a vast array of misconceptions and stigma. The pervasive nature of this stigma permeates society and culture at many levels. Persons with MCI who are at higher risk for development of dementia may be especially vulnerable to fear and stigma associated with the diagnosis. Based on this premise, the primary aim of this study was to examine the relationship between perceived stigma and perceived stress in persons with MCI and their care partners, including the relationship between income and the study variables. The secondary aim was to examine the effect of a combined cognitive rehabilitation and wellness program on these perceptions.

Methods

Thirty participants were recruited from Mayo Clinic's Health Action to Benefit Independence and Thinking (HABIT) program. MCI (n = 15) and care partner (n = 15) participants completed the Stigma Impact Scale (SIS) and the Perceived Stress Scale (PSS) before and after the HABIT program.

Results

Average SIS and PSS scores decreased in the MCI, care partner, and combined groups, both pre- and post-HABIT. Linear regression was used to assess the relationship between perceived stigma and stress, controlling for income. A significant relationship was found between perceived stigma and perceived stress both pre and post-HABIT.

Discussion

The results suggest a relationship exists between perceived stigma and perceived stress in persons with MCI and their care partners, and an educational program such as HABIT may strengthen this relationship by informing participants of potential challenges that occur in cognitive decline. Understanding these relationships may provide an opportunity to provide tools for this vulnerable population.

Current Challenges in the Diagnosis of Progressive Neurocognitive Disorders: A Critical Review of the Literature and Recommendations for Primary and Secondary Care

Screening for early symptoms of cognitive impairment enables timely interventions for patients and their families. Despite the advances in dementia diagnosis, the current nosography of neurocognitive disorders (NCDs) seems to overlook some clinical manifestations and predictors that could contribute to understanding the conversion from an asymptomatic stage to a very mild one, eventually leading to obvious disease. The present review examines different diagnostic approaches in view of neurophysiological and neuropsychological evidence of NCD progression, which may be subdivided into: (1) preclinical stage; (2) transitional stage; (3) prodromal or mild stage; (4) major NCD. The absence of univocal criteria and the adoption of ambiguous or narrow labels might complicate the diagnostic process. In particular, it should be noted that: (1) only neuropathological hallmarks characterize preclinical NCD; (2) transitional NCD must be assessed through proactive neuropsychological protocols; (3) prodromal/mild NCDs are based on cognitive functional indicators; (4) major NCD requires well-established tools to evaluate its severity stage; (5) insight should be accounted for by both patient and informants. Therefore, the examination of evolving epidemiological and clinical features occurring at each NCD stage may orient primary and secondary care, allowing for more targeted prevention, diagnosis, and/or treatment of both cognitive and functional impairment.

Risk Prediction Performance of the Thai Cardiovascular Risk Score for Mild Cognitive Impairment in Adults with Metabolic Risk Factors in Thailand

Individuals with metabolic risks are at high risk of cognitive impairment. We aimed to investigate whether the Thai Cardiovascular Risk (TCVR) score can be used to predict mild cognitive impairment (MCI) in Thai adults with metabolic risks. The study was conducted using secondary data of patients with metabolic risks from Maharaj Nakorn Chiang Mai Hospital. MCI was indicated by an MoCA score of less than 25. Six different TCVR models were used with various combinations of ten different variables for predicting the risk of MCI. The area under the receiver operator characteristic curve (AuROC) and Hosmer–Lemeshow goodness of fit tests were used for determining discriminative performance and model calibration. The sensitivity of the discriminative performance was further evaluated by stratifying by age and gender. From a total of 421 participants, 348 participants had MCI. All six TCVR models showed a similar AuROC, varying between 0.58 and 0.61. The anthropometric-based model showed the best risk prediction performance in the older age group (AuROC 0.69). The laboratory-based model provided the highest discriminative performance for the younger age group (AuROC 0.60). There is potential for the development of an MCI risk model based on values from routine cardiovascular risk assessments among patients with metabolic risks.