Effect of cognitive reserve on cognitive function in Parkinson’s disease

Risk factors for falls in Parkinson's disease: a cross-sectional observational and Mendelian randomization study

Background

Patients with Parkinson's disease (PD) exhibit a heightened risk of falls and related fractures compared to the general population. This study aims to assess the clinical characteristics associated with falls in the patient with PD and to gain further insight into these factors through Mendelian randomization analysis.

Methods

From January 2013 to December 2023, we included 591 patients diagnosed with Parkinson's disease at Shenzhen Baoan People's Hospital. Using univariate and multivariate logistic regression analyses, we identified clinical variables associated with falls. We constructed a nomogram based on these variables and evaluated the predictive efficacy of the model. Additionally, we employed summary statistics from genome-wide association studies to conduct two-sample Mendelian randomization (MR) analyses on key variables influencing falls.

Results

Compared to the control group, we identified osteoporosis, motor dysfunction, higher Hoehn and Yahr scale as significant risk factors for falls in PD patients. Conversely, treatment with levodopa and a higher level of education exhibited a protective effect against the risk of falling. MR analysis further confirmed a causal relationship between osteoporosis, education level and falls in PD patients.

Conclusion

Osteoporosis and educational attainment are correlated with falls in Parkinson's disease.

Psychometric properties and normative data of the Italian version of the Cognitive Function at Work Questionnaire: a screening tool for detecting subjective cognitive complaints at work

INTRODUCTION

Considering the extension of working life due to socioeconomic and political factors, many people may experience cognitive complaints (CC) at their workplace, with severe consequences on their quality of life. The identification of workers reporting significative SCC is crucial to eventually address them to an objective neuropsychological evaluation and implement cognitive interventions to guarantee workers' well-being. Since no Italian questionnaires for detecting CC were designed for occupational settings, the aim of the study was to validate the Italian version of the Cognitive Function at Work Questionnaire (CFWQ) and to provide its normative data.

MATERIALS AND METHODS

Internal consistency, convergent and divergent validity, and factorial structure of the CFWQ were evaluated. A regression-based procedure served to compute percentiles of CFWQ and its subscales.

RESULTS

Four hundred twenty-one participants without psychiatric and/or neurological disorders completed the survey. We found that the Italian CFWQ included 26 items, with a good internal consistency (Cronbach's alpha = 0.897) and a six-factor structure (memory, language, processing speed, abstract thinking/behavioral control, behavioral inertia, planning ability). CFWQ score did not correlate with empathy but correlated strongly with memory scores and moderately with anxiety and depression scores.

CONCLUSIONS

The Italian CFWQ showed good psychometric properties, in analogy with the original English scale. Therefore, it can be successfully employed in organizational contexts to possibly identify workers with CC and therefore with possible co-occurrent psychological, behavioral, and cognitive consequences.

Influence of cognitive reserve on cognitive and motor function in α-synucleinopathies: A systematic review and multilevel meta-analysis

Cognitive reserve has shown promise as a justification for neuropathologically unexplainable clinical outcomes in Alzheimer's disease. Recent evidence suggests this effect may be replicated in conditions like Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. However, the relationships between cognitive reserve and different cognitive abilities, as well as motor outcomes, are still poorly understood in these conditions. Additionally, it is unclear whether the reported effects are confounded by medication. This review analysed studies investigating the relationship between cognitive reserve and clinical outcomes in these α-synucleinopathy cohorts, identified from MEDLINE, Scopus, psycINFO, CINAHL, and Web of Science. 85 records, containing 176 cognition and 31 motor function effect sizes, were pooled using multilevel meta-analysis. There was a significant, positive association between higher cognitive reserve and both better cognition and motor function. Cognition effect sizes differed by disease subtype, cognitive reserve measure, and outcome type; however, no moderators significantly impacted motor function. Review findings highlight the clinical implications of cognitive reserve and importance of engaging in reserve-building behaviours.

GBA moderates cognitive reserve's effect on cognitive function in patients with Parkinson's disease

BACKGROUND

Cognitive reserve (CR) involves an individual's ability to maintain cognitive vitality over their lifespan. Glucocerebrosidase (GBA) gene mutations contribute to additional effects on cognitive function in Parkinson's disease (PD) patients, but the interplay between GBA mutations and CR remains unclear. We investigated the interactions among CR, GBA, and diseases, aiming to examine whether the CR established at different stages interacts with specific genotypes to affect cognitive function.

METHODS

Three hundred and eighteen participants' CR indicators (i.e., education, occupation, and social function) and comprehensive neuropsychological function (i.e., tests for executive function, attention/working memory, visuospatial function, memory, and language) were evaluated.

RESULTS

We found that CR established in a specific life stage influences the individual's cognitive function, particularly in PD, based on their distinct GBA rs9628662 genotypes. Attention/working memory and memory performance are affected by occupational complexity in midlife in PD patients with the GG genotype (q < 0.0001; q < 0.0001) and healthy adults with the T genotype (q = 0.0440; q < 0.0001). Language is influenced by early education and occupation, and the effects of occupation are also observed in PD patients with the GG genotype (q = 0.0040) and in healthy adults carrying the T genotype (q = 0.0040).

CONCLUSIONS

CR, established at different life stages, can be influenced by the GBA rs9628662 genotype, impacting later-life cognition. Validating genotypes and incorporating genotype information when assessing cognitive reserve effects is crucial and can enhance targeted cognitive training.

Relationship between lifestyle proxies of cognitive reserve and cortical regions in older adults

Introduction

With the rapid increase in the population over 65 years old, research on healthy aging has become one of the priorities in the research community, looking for a cost-effective method to prevent or delay symptoms of mild cognitive disorder or dementia. Studies indicate that cognitive reserve theory could be beneficial in this regard. The aim of this study was to investigate the potential relationship between lifestyle socio-behavioral proxies of cognitive reserve and cortical regions in adults with no subjective cognitive decline.

Methods

Overall, 58 participants, aged 65-85 years, were included in the data analysis (M = 71.83, SD = 5.02, 20.7% male). Cognitive reserve proxies were measured using the Cognitive Reserve Index questionnaire, while cortical volumes were obtained with the Siemens 1.5 T Avanto MRI scanner and further mapped using the Desikan-Killiany-Tourville (DKT) Atlas. Estimated intracranial volume and age were used as covariates.

Results

The results indicated that higher occupational complexity was associated with larger cortical volume in the left middle temporal gyrus, the left and right inferior temporal gyrus, and the left inferior parietal lobule, while a combined proxy (the total CRI score) showed a positive relationship with the volume of left middle temporal gyrus and inferior parietal lobule, and pars orbitalis in the right hemisphere.

Discussion

These results might indicate that more complex occupational activities and overall more intellectually and socially active life-style could contribute to better brain health, especially in regions known to be more vulnerable to Alzheimer's disease.

Proxy-analysis of the genetics of cognitive decline in Parkinson's disease through polygenic scores

Cognitive decline is common in Parkinson's disease (PD) and its genetic risk factors are not well known to date, besides variants in the GBA and APOE genes. However, variation in complex traits is caused by numerous variants and is usually studied with genome-wide association studies (GWAS), requiring a large sample size, which is difficult to achieve for outcome measures in PD. Taking an alternative approach, we computed 100 polygenic scores (PGS) related to cognitive, dementia, stroke, and brain anatomical phenotypes and investigated their association with cognitive decline in six longitudinal cohorts. The analysis was adjusted for age, sex, genetic ancestry, follow-up duration, GBA and APOE status. Then, we meta-analyzed five of these cohorts, comprising a total of 1702 PD participants with 6156 visits, using the Montreal Cognitive Assessment as a cognitive outcome measure. After correction for multiple comparisons, we found four PGS significantly associated with cognitive decline: intelligence (p = 5.26e-13), cognitive performance (p = 1.46e-12), educational attainment (p = 8.52e-10), and reasoning (p = 3.58e-5). Survival analyses highlighted an offset of several years between the first and last quartiles of PGS, with significant differences for the PGS of cognitive performance (5 years) and educational attainment (7 years). In conclusion, we found four PGS associated with cognitive decline in PD, all associated with general cognitive phenotypes. This study highlights the common genetic factors between cognitive decline in PD and the general population, and the importance of the participant's cognitive reserve for cognitive outcome in PD.

Measures of cognitive reserve: An umbrella review

Objective: Recently, there has been a growing interest in operationalizing and measuring cognitive reserve (CR) for clinical and research purposes. This umbrella review aims to summarize the existing systematic and meta-analytic reviews about measures of CR. Method: A literature search was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the guidelines of Aromataris et al. (2015) to identify the systematic reviews and meta-analysis involving the assessment of CR. The methodological quality of the papers included in this umbrella review was assessed with A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR-2) and Specialist Unit for Review Evidence (SURE). Results: Thirty-one reviews were identified, sixteen of which were systematic reviews, and fifteen were meta-analyses. Most of the reviews had a critically low quality, according to AMSTAR-2. The reviews included between two and 135 studies. Most of the papers focused on older adults, mainly those with dementia. CR was measured using one to six proxies, but most considered each proxy separately. The most assessed proxies of CR were education on its own, combined with occupation and/or engagement in activities or combined with parental education, bilingualism, and engagement in activities when four CR proxies were studied. Most of the studies included in higher quality reviews focused on three proxies, with education and engagement in activities being the most evaluated using CR questionnaires. Conclusion: Despite the growing interest in measuring CR, its operationalization did not improve since the last umbrella review in this field.

Influence of cognitive reserve on cognitive and motor function in α-synucleinopathies: A systematic review protocol

Cognitive reserve has been used to justify neuropathologically unexplainable mismatches in Alzheimer's disease outcomes. Recent evidence has suggested this effect may be replicable across other conditions. However, it is still unclear whether cognitive reserve applies to α-synucleinopathies or to motor outcomes, or if medication confounds effects. This review protocol follows PRISMA-P guidelines and aims to investigate whether cognitive reserve can predict both cognitive and motor outcomes for α-synucleinopathy patients. MEDLINE (via PubMed), Scopus, psycINFO (via Ovid), CINAHL (via EBSCO), and Web of Science have been searched. Cross-sectional, cohort, case-control, and longitudinal studies investigating the association between cognitive reserve and cognitive and/or motor outcomes for Parkinson's disease, dementia with Lewy bodies, or multiple system atrophy will be included. Reviewers will independently perform screening, while also extracting data, assessing the risk of bias (using a version of the Quality in Prognostic Studies tool), and rating evidence quality (using GRADE). If possible, random-effects meta-analyses will be conducted for each unique outcome variable and α-synucleinopathy; otherwise, a narrative synthesis will be performed. Depending on the number of studies, exploratory analyses may involve meta-regression to assess potential confounding effects. Understanding the broader protective effect of cognitive reserve has significant implications for preventive interventions in the wider population.

Outcome of visuospatial dysfunction assessment in patients with Parkinson's disease using mobile application software

Background

Visuospatial dysfunction and cognitive impairment are common in Parkinson's disease (PD), which draw increasing attention in the current literature. But clinicians still lack rapid, effective and unified cognitive battery for visuospatial assessment.

Objective

A new approach was studied to explore the feasibility of using mobile application software (APP) to evaluate visuospatial dysfunction in patients with PD and compared with traditional assessment tools. We aimed to verify the threshold score of the APP for early diagnosis.

Materials and methods

A total of 41 patients with PD underwent assessments using several test modules including Digit Symbol Test (DST), Visual Organization Test (VOT), Facial Recognition Test (FRT), Vocabulary Memory Test (VMT) of this APP, as well as Clock Drawing Test (CDT), Cube Copying Test (CCT) and the Mini-Mental State Examination (MMSE) for comparison. Among the 41 PD patients, 30 individuals were found to have visuospatial dysfunction based on CDT score < 5 and CCT score of<18 while the remaining 11 patients served as control.

Results

There were statistically significant differences in DST, VOT, and FRT scores (all p ≤ 0.001 for group comparisons). DST, VOT, and FRT-1 were significantly correlated with MMSE, CDT and CCT and the correlations were moderate or fairly strong. For visuospatial dysfunction diagnosis, all the areas under curves (AUC) of DST, VOT, and FRT-1 were statistically significant (p < 0.0001, p = 0.0002, and p = 0.0002, respectively). The estimates and 95% confidence intervals of AUC were 0.8303 (0.6868, 0.9739), 0.8045 (0.6423, 0.9668), and 0.7833 (0.6344, 0.9322), respectively. Their cut-off points for visuospatial dysfunction were 26, 17, and 19, respectively. After dichotomization by the cut-off points, DST had high sensitivity of 96.67% while VOT and FRT-1 had high specificity of 81.82 and 90.91%.

Conclusion

This study demonstrated that visuospatial disorders was highly prevalent in PD patients, and the APP used in study could be a practical clinical screening tool for visuospatial ability assessment with high sensitivity and specificity.

Cognitive reserve profiles are associated with outcome in schizophrenia

Cognitive reserve (CR), the brain's ability to cope with brain pathology to minimize symptoms, could explain the heterogeneity of outcomes in neuropsychiatric disorders, however it is still rarely investigated in schizophrenia. Indeed, this study aims to classify CR in this disorder and evaluate its impact on neurocognitive and socio-cognitive performance and daily functioning. A group of 106 patients diagnosed with schizophrenia was enrolled and assessed in these aereas: neurocognition, Theory of Mind (ToM) and daily functioning. A composite CR score was determined through an integration of the intelligence quotient and education and leisure activities. CR profiles were classified with a two-step cluster analysis and differences among clusters were determined with an analysis of variance (ANOVA). The cluster analysis was identified with three CR profiles characterized, respectively, by high, medium and low CR. ANOVA analysis showed significant differences on neurocognition, ToM and daily functioning between the clusters: people with higher CR reached significantly superior scores. This study suggests that greater general cognitive resources could act as a buffer against the effect of brain pathology, allowing patients to have a better cognitive performance, social outcome and quality of life.