Prevalence and Clinical Aspects of Mild Cognitive Impairment in Parkinson's Disease: A Meta‐Analysis

Cognitive reserve and executive functions in dual task gait performance in Parkinson's disease

A higher level of education was correlated with less severe motor impairment in Parkinson's Disease (PD). Nevertheless, there is limited evidence on the relationship between cognitive reserve and motor performance in complex situations in PD. To investigate the association between cognitive reserve and the dual-task gait effect in PD. Additionally, we examined the relationship between executive function, clinical and sociodemographic variables and, dual-task gait effects. We conducted a cross-sectional study with 44 PD participants. We evaluated dual-task effect on cadence, stride length, and gait velocity. Dual-task effects were correlated with neurophysiological factors, including cognitive reserve (Cognitive Reserve Index Questionnaire), overall cognitive performance of executive functions, a specific executive function domain (Trail Making Test), and the global cognitive status (Montreal Cognitive Assessment and Mini-Mental State Examination). Age, gender, and disease severity were considered as variables to be examined for correlation. We found that cognitive reserve did not influence gait performance under dual-task conditions in this sample. However, executive functions, age, and disease severity were associated with the dual-task effect on gait. The overall cognitive performance with respect to the Trail Making Test showed an inverse relationship in the dual-task gait effect on cadence. Our study's findings have important implications for understanding the association between executive functions, age, and disease severity with the dual-task effect on gait in PD. Pre-life factors, such as education, occupation, and leisure activity, did not contribute to coping with complex gait situations in PD.

The Care Needs of Patients With Cognitive Impairment in Late-Stage Parkinson's Disease

BACKGROUND

Cognitive impairment is common in Parkinson's disease (PD), but care needs and resource use for those with significant cognitive impairment are not well established.

METHODS

675 participants with PD from the international Care of Late-Stage Parkinsonism (CLaSP) study were grouped into those without (n = 333, 49%) and with cognitive impairment (MMSE < 24/30 or diagnosis of dementia or Mild Cognitive Impairment; n = 342, 51%) and their clinical features, care needs and healthcare utilisation compared. The relationship between cognition and healthcare consultations was investigated through logistic regression.

RESULTS

Cognitive impairment was associated with more motor and non-motor symptoms, less antiparkinsonian but higher rates of dementia and antipsychotic medication, worse subjective health status and greater caregiver burden. A considerable proportion did not have a pre-established cognitive diagnosis. Care needs were high across the whole sample but higher in the cognitive impairment group. Home care and care home use was higher in the cognitive impairment group. However, use of healthcare consultations was similar between the groups and significantly fewer participants with cognitive impairment had had recent PD Nurse consultations. Worse cognitive impairment was associated with lower frequency of recent PD nurse and multidisciplinary therapy consultation (physiotherapy, massage, occupational therapy, speech training and general nursing).

CONCLUSIONS

Those with cognitive impairment have more severe PD, higher care needs and greater social care utilisation than those with normal cognition, yet use of health care services is similar or less. Cognitive impairment appears to be a barrier to PD nurse and multidisciplinary therapy consultations. This challenges current models of care: alternative models of care may be required to serve this population.

PLAIN LANGUAGE SUMMARY

Parkinson's disease is a long-term progressive health condition. Over time, many people with Parkinson's develop problems with thinking and memory, called cognitive impairment. This can negatively impact the daily lives of the person with Parkinson's and their caregiver. It is also thought to be a barrier to accessing healthcare. How people with Parkinson's who have cognitive impairment use healthcare and detail of their care needs is not well known.We analysed data from a large sample of people with advanced Parkinson's from six European countries to investigate their symptoms, care needs and healthcare use. We compared those with cognitive impairment to (342 people) to those without cognitive impairment (333 people).We found that those with cognitive impairment had more severe Parkinson's across a range of symptoms compared to those without cognitive impairment. They also had more care needs, reported their health status to be worse, and their caregivers experienced greater strain from caring. Whilst use of other healthcare services was similar between the two groups, those with cognitive impairment were less likely to have recently seen a Parkinson's nurse than those without cognitive impairment. Further analysis showed an association between cognitive impairment and not having seen a Parkinson's nurse or therapist recently, taking psychiatric symptoms, functional disability and care home residence into account. Therapists included were physiotherapy, massage, occupational therapy, speech training and general nursing. These findings highlight unmet need. We suggest that healthcare should be more targeted to help this group of people, given their higher care needs.

Capturing subjective cognitive decline with a new combined index in low education patients with Parkinson's disease

Objectives

Subjective Cognitive Decline (SCD) refers to self-reported cognitive decline with normal global cognition. This study aimed to capture SCD among low educated patients with Parkinson's disease (PD) using a newly established indicator.

Methods

We recruited 64 PD patients with low education levels (education ≤12 years) for the study. The presence of SCD was determined based on a Unified Parkinson's Disease Rating Scale Part I (1.1) score ≥ 1. Spearman analysis and multivariate binary logistic regression analyses were conducted to investigate factors associated with the PD-SCD group. The receiver operating characteristic (ROC) curve was used to evaluate the sensitivity and specificity of the new combined index.

Results

The prevalence of SCD in PD patients was 43.75%. Low educated PD-SCD patients had higher scores on the Non-Motor Symptoms Scale (NMSS), Parkinson's Fatigue Scale (PFS), Epworth Sleepiness Scale (ESS), as well as higher scores on the UPDRS-I and UPDRS-II, compared to PD patients without SCD. They also demonstrated poorer performance on the Montreal Cognitive Assessment (MoCA), particularly in the domains of executive abilities/attention/language. Multivariate binary regression confirmed the significant association between PD-SCD and MoCA-executive abilities/attention/language. Based on these findings, a combined index was established by summing the scores of MoCA-executive abilities, MoCA-attention, and MoCA-language. ROC analysis showed that the combined index could differentiate PD-SCD patients with an area under the curve (AUC) of 0.876. A score of 12 or less on the combined index had a sensitivity of 73.9% and a specificity of 76.2% for diagnosing PD-SCD.

Conclusion

These low education patients with PD-SCD may exhibit potential PD-related pathological changes. It is important for clinicians to identify PD-SCD patients as early as possible. The newly combined index can help capture these low educated PD-SCD patients, with an AUC of 0.867, and is expected to assist clinicians in earlier identification and better management of PD patients.

Prevalence of Mild and Severe Cognitive Impairment in World Trade Center Exposed Fire Department of the City of New York (FDNY) and General Emergency Responders

Background

The emergency personnel who responded to the World Trade Center (WTC) attacks endured severe occupational exposures, yet the prevalence of cognitive impairment remains unknown among WTC-exposed-FDNY-responders. The present study screened for mild and severe cognitive impairment in WTC-exposed FDNY responders using objective tests, compared prevalence rates to a cohort of non-FDNY WTC-exposed responders, and descriptively to meta-analytic estimates of MCI from global, community, and clinical populations.

Methods

A sample of WTC-exposed-FDNY responders (n = 343) was recruited to complete an extensive battery of cognitive, psychological, and physical tests. The prevalences of domain-specific impairments were estimated based on the results of norm-referenced tests, and the Montreal Cognitive Assessment (MoCA), Jak/Bondi criteria, Petersen criteria, and the National Institute on Aging and Alzheimer's Association (NIA-AA) criteria were used to diagnose MCI. NIA-AA criteria were also used to diagnose severe cognitive impairment. Generalized linear models were used to compare prevalence estimates of cognitive impairment to a large sample of WTC-exposed-non-FDNY responders from the General Responder Cohort (GRC; n = 7102) who completed the MoCA during a similar time frame.

Result

Among FDNY responders under 65 years, the unadjusted prevalence of MCI varied from 52.57% to 71.37% depending on the operational definition of MCI, apart from using a conservative cut-off applied to MoCA total scores (18 < MoCA < 23), which yielded a markedly lower crude prevalence (24.31%) compared to alternative criteria. The prevalence of MCI was higher among WTC-exposed-FDNY-responders, compared to WTC-exposed-non-FDNY-GRC-responders (adjusted RR = 1.53, 95% C.I. = [1.24, 1.88], p < .001) and meta-analytic estimates from different global, community, and clinical populations. Following NIA-AA diagnostic guidelines, 4.96% of WTC-exposed-FDNY-responders met the criteria for severe impairments (95% CI = [2.91% to 7.82%]), a prevalence that remained largely unchanged after excluding responders over the age of 65 years.

Discussion

There is a high prevalence of mild and severe cognitive impairment among WTC-responders highlighting the putative role of occupational/environmental and disaster-related exposures in the etiology of accelerated cognitive decline.

Mid- and late-life lifestyle activities as main drivers of general and domain-specific cognitive reserve in individuals with Parkinson's disease: cross-sectional and longitudinal evidence from the LANDSCAPE study

BACKGROUND

Cognitive reserve (CR) is considered a protective factor for cognitive function and may explain interindividual differences of cognitive performance given similar levels of neurodegeneration, e.g., in Alzheimer´s disease. Recent evidence suggests that CR is also relevant in Parkinson's disease (PD).

OBJECTIVE

We aimed to explore the role of life-stage specific CR for overall cognition and specific cognitive domains cross-sectionally and longitudinally in PD.

METHODS

The cross-sectional analysis with data from the DEMPARK/LANDSCAPE study included 81 individuals without cognitive impairment (PD-N) and 87 individuals with mild cognitive impairment (PD-MCI). Longitudinal data covered 4 years with over 500 observations. CR was operationalized with the Lifetime of Experiences Questionnaire (LEQ), capturing the complexity of lifestyle activities across distinct life-stages. Cognition was assessed using a comprehensive neuropsychological test battery.

RESULTS

Higher LEQ scores, particularly from mid- and late-life, were observed in PD-N compared to PD-MCI [F(1,153) = 4.609, p = .033, ηp2 = 0.029]. They were significantly associated with better cognitive performance (0.200 ≤ β ≤ 0.292). Longitudinally, linear mixed effect models (0.236 ≤ marginal R2 ≤ 0.441) revealed that LEQ scores were positively related to cognitive performance independent of time. However, the decline in overall cognition and memory over time was slightly more pronounced with higher LEQ scores.

CONCLUSIONS

This study emphasizes the association between complex lifestyle activities and cognition in PD. Data indicate that while CR might be related to a delay of cognitive decline, individuals with high CR may experience a more pronounced drop in overall cognition and memory. Future studies will have to replicate these findings, particularly regarding domain-specific effects and considering reverse causal mechanisms.

Psychometrics and diagnostics of the Italian version of the Alternate Verbal Fluency Battery (AVFB) in non-demented Parkinson's disease patients

BACKGROUND

Verbal fluency (VF) tasks are known as suitable for detecting cognitive impairment (CI) in Parkinson's disease (PD). This study thus aimed to evaluate the psychometrics and diagnostics of the Alternate Verbal Fluency Battery (AVFB) by Costa et al. (2014) in an Italian cohort of non-demented PD patients, as well as to derive disease-specific cut-offs for it.

METHODS

N = 192 non-demented PD patients were screened with the Montreal Cognitive Assessment (MoCA) and underwent the AVFB-which includes phonemic, semantic and alternate VF tests (PVF; SVF; AVF), as well as a Composite Shifting Index (CSI) reflecting the "cost" of shifting from a single- to a double-cued VF task. Construct validity and diagnostics were assessed for each AVFB measure against the MoCA. Internal reliability and factorial validity were also tested.

RESULTS

The MoCA proved to be strongly associated with PVF, SVF and AVF scores, whilst moderately with the CSI. The AVFB was internally consistent and underpinned by a single component; however, an improvement in both internal reliability and fit to its factorial structure was observed when dropping the CSI. Demographically adjusted scores on PVF, SVF and AVF tests were diagnostically sound in detecting MoCA-defined cognitive impairment, whilst this was not true for the CSI. Disease-specific cut-offs for PVF, SVF and AVF tests were derived.

DISCUSSION

In conclusion, PVF, SVF and AVF tests are reliable, valid and diagnostically sound instruments to detect cognitive impairment in non-demented PD patients and are therefore recommended for use in clinical practice and research.

Parkinson's disease CA2-CA3 hippocampal atrophy is accompanied by increased cholinergic innervation in patients with normal cognition but not in patients with mild cognitive impairment

Although brain cholinergic denervation has been largely associated with cognitive decline in patients with Parkinson's disease (PD), new evidence suggests that cholinergic upregulation occurs in the hippocampus of PD patients without cognitive deficits. The specific hippocampal sectors and potential mechanisms of this cholinergic compensatory process have been further studied here, using MRI volumetry and morphometry coupled with molecular imaging using the PET radiotracer [18F]-Fluoroethoxybenzovesamicol ([18F]-FEOBV). Following a thorough screening procedure, 18 participants were selected and evenly distributed in three groups, including cognitively normal PD patients (PD-CN), PD patients with mild cognitive impairment (PD-MCI), and healthy volunteers (HV). Participants underwent a detailed neuropsychological assessment, structural MRI, and PET imaging with [18F]-FEOBV. Basal forebrain Ch1-Ch2 volumes were measured using stereotaxic mapping. Hippocampal subfields were automatically defined using the MAGeT-Brain segmentation algorithm. Cholinergic innervation density was quantified using [18F]-FEOBV uptake. Compared with HV, both PD-CN and PD-MCI displayed significantly reduced volumes in CA2-CA3 bilaterally. We found no other hippocampal subfield nor Ch1-Ch2 volume differences between the three groups. PET imaging revealed higher [18F]-FEOBV uptake in CA2-CA3 of the PD-CN compared with HV or PD-MCI. A positive correlation was observed between cognitive performances and [18F]-FEOBV uptake in the right CA2-CA3 subfield. Reduced volume, together with increased [18F]-FEOBV uptake, were observed specifically in the CA2-CA3 hippocampal subfields. However, while the volume change was observed in both PD-CN and PD-MCI, increased [18F]-FEOBV uptake was present only in the PD-CN group. This suggests that a cholinergic compensatory process takes place in the atrophied CA2-CA3 hippocampal subfields and might underlie normal cognition in PD.

Neutrophil-to-lymphocyte ratio and longitudinal cognitive performance in Parkinson's disease

OBJECTIVE

Previous studies have suggested a link between peripheral inflammation and cognitive outcomes in the general population and individuals with Parkinson's disease (PD). We sought to test the association between peripheral inflammation, measured by the neutrophil-to-lymphocyte ratio (NLR), cognitive performance, and mild cognitive impairment (MCI) status in individuals with PD.

METHODS

A retrospective, longitudinal analysis was carried out using data from the Parkinson's Progression Markers Initiative (PPMI), including 422 participants with PD followed over 5 years. Cognitive performance was assessed using a neuropsychological battery including the Montreal Cognitive Assessment (MoCA) and tests of verbal learning, visuospatial function, processing speed, and executive function. Mixed-effect regression models were used to analyze the association between NLR, cognitive performance, and MCI status, controlling for age, sex, education, APOE genotype, and motor severity.

RESULTS

There was a negative association between NLR and MoCA, even after adjusting for covariates (b = -0.12, p = 0.033). MoCA scores for individuals in the high NLR category exhibited a more rapid decline over time compared to the low NLR group (b = -0.16, p = 0.012). Increased NLR was associated with decreased performance across all cognitive domains. However, NLR was not associated with MCI status over 5 years of follow-up.

INTERPRETATION

This study demonstrates a link between elevated NLR and cognitive performance in PD, but not with MCI status over 5 years. This suggests that NLR is more strongly associated with day-to-day cognitive performance than with incident MCI, but this requires further study in more heterogeneous cohorts.

Unraveling sex differences in Parkinson's disease through explainable machine learning

Sex differences affect Parkinson's disease (PD) development and manifestation. Yet, current PD identification and treatments underuse these distinctions. Sex-focused PD literature often prioritizes prevalence rates over feature importance analysis. However, underlying aspects could make a feature significant for predicting PD, despite its score. Interactions between features require consideration, as do distinctions between scoring disparities and actual feature importance. For instance, a higher score in males for a certain feature doesn't necessarily mean it's less important for characterizing PD in females. This article proposes an explainable Machine Learning (ML) model to elucidate these underlying factors, emphasizing the importance of features. This insight could be critical for personalized medicine, suggesting the need to tailor data collection and analysis for males and females. The model identifies sex-specific differences in PD, aiding in predicting outcomes as "Healthy" or "Pathological". It adopts a system-level approach, integrating heterogeneous data - clinical, imaging, genetics, and demographics - to study new biomarkers for diagnosis. The explainable ML approach aids non-ML experts in understanding model decisions, fostering trust and facilitating interpretation of complex ML outcomes, thus enhancing usability and translational research. The ML model identifies muscle rigidity, autonomic and cognitive assessments, and family history as key contributors to PD diagnosis, with sex differences noted. The genetic variant SNCA-rs356181 may be more significant in characterizing PD in males. Interaction analysis reveals a greater occurrence of feature interplay among males compared to females. These disparities offer insights into PD pathophysiology and could guide the development of sex-specific diagnostic and therapeutic approaches.

The Effects of Multidisciplinary Intensive Rehabilitation on Cognitive and Executive Functions in Parkinson's Disease: A Clinical Database Analysis

Background/Objectives: This study is based on data collected from a medical health record review to assess whether multidisciplinary intensive rehabilitation treatment in Parkinson's disease (PD) patients can improve global cognitive functioning and executive functions. Methods: The data related to PD patients were extrapolated from a clinical database called "NeuroRehab". A total of 104 PD patients (51 males; 53 females) performed 6 weeks of multidisciplinary intensive rehabilitation treatment in clinical practice from January 2019 to May 2023. This training program was characterized by three daily sessions of 60 min of activities (muscle relaxation and stretching exercises, moderate physical aerobic exercise, and occupational therapy). The patients were classified and stratified according to disease severity (according to the Hoehn and Yahr scale), postural instability and gait difficulty (PIGD) or tremor-dominant (TD) subtypes, disease duration (DD), and the presence of dyskinesias. The effect of multidisciplinary intensive rehabilitation treatment on cognitive and executive functions was evaluated through the administration of cognitive tests, such as the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Frontal Assessment Battery (FAB). All the parameters were evaluated at the baseline (T0) and at the end of the rehabilitation program (T1). Results: The multidisciplinary intensive rehabilitation treatment significantly improved cognitive performance. The MMSE, MoCA, and FAB test scores after the rehabilitation program (T1) were significantly higher compared to the scores obtained at the baseline (T0). Moreover, further analyses on subgroups of the patients who scored below the cut-off in the MMSE showed that at least 50% of patients overcame the cut-off score. Interestingly, the same analyses performed for the MoCA and FAB revealed a higher rate of improvement in cognitive functions, with normal scores in both tests after 6 weeks of multidisciplinary intensive rehabilitation treatment. Conclusions: This study revealed the potential effects of a 6-week multidisciplinary rehabilitation program in improving cognitive status in a PD inpatient cohort.

Are the criteria for PD-MCI diagnosis comprehensive? A Machine Learning study with modified criteria

BACKGROUND

Mild cognitive impairment in Parkinson's disease (PD-MCI) includes deficits in different cognitive domains, and one domain to explore for neurocognitive impairment following the DSM-V is social cognition. However, this domain is not included in current criteria for PD-MCI diagnosis. Moreover, tests vary across studies. It is, therefore, crucial to optimize cognitive assessment in PD-MCI. We aimed to do so by using Machine Learning.

METHODS

275 PD patients were included. Four cognitive batteries were created: two Standard ones (Levels I and II), applying current criteria and "traditional" tests; two Alternative ones (Levels I and II), which incorporated a test of social cognition. These batteries were included in the Random Forest (RF) classifier. To assess RF performance, the AUC was considered, and the Variable Importance Index was estimated to understand the contribution of each test in PD-MCI classification.

RESULTS

Standard Level I and II showed an AUC of 0.852 and 0.892, while Alternative Level I and II showed an AUC of 0.898 and of 0.906. Variable Importance Index revealed that TMT B-A, Ekman test, RAVLT-IR, MoCA, and Action Naming were tests that most contributed to PD-MCI classification.

CONCLUSION

The Alternative level I assessment demonstrated a similar classification capacity to the Standard level II assessment. This finding suggests that in the cognitive assessment of PD patients, it is crucial to consider the most affected cognitive domains in this clinical population, including social cognition. Taken together, these results suggest to revise current criteria for the diagnosis of PD-MCI.

Assessment tools for cognitive performance in Parkinson's disease and its genetic contributors

Background

We have shown that genetic factors associating with motor progression of Parkinson's disease (PD), but their roles in cognitive function is poorly understood. One reason is that while cognitive performance in PD can be evaluated by various cognitive scales, there is no definitive guide indicating which tool performs better.

Methods

Data were obtained from the Parkinson's Progression Markers Initiative, where cognitive performance was assessed using five cognitive screening tools, including Symbol Digit Modalities Test (SDMT), Montreal Cognitive Assessment, Benton Judgment of Line Orientation, Modified Semantic Fluency Test, and Letter Number Sequencing Test, at baseline and subsequent annual follow-up visit for 5 years. Genetic data including ApoE and other PD risk genetic information were also obtained. We used SPSS-receiver operating characteristic and ANOVA repeated measures to evaluate which cognitive assessment is the best reflecting cognitive performance in PD at early stage and over time. Logistic regression analyses were used to determine the genetic associations with the rapidity of cognitive decline in PD.

Results

SDMT performed better in detecting mild cognitive impairment at baseline (AUC = 0.763), and SDMT was the only tool showing a steady cognitive decline during longitudinal observation. Multigenetic factors significantly associated with cognitive impairment at early stage of the disease (AUC = 0.950) with IP6K2 rs12497850 more evident, and a significantly faster decline (AUC = 0.831) within 5 years after motor onset, particularly in those carrying FGF20 rs591323.

Conclusion

SDMT is a preferable cognitive assessment tool for PD and genetic factors synergistically contribute to the cognitive dysfunction in PD.

Financial capability of people living with Parkinson's disease - A case-control study

Parkinson's disease (PD) is a neurodegenerative disorder affecting 1% of people older than 60 years. One of the abilities that seems vulnerable to the cognitive impairments associated with PD is financial capability. This explorative study aimed to evaluate the extent and type of problems in financial capability of people with PD without a diagnosis of dementia. Participants were 31 people with PD and 62 matched controls. Participants completed an extensive test-battery, including measures for financial capability and cognitive functioning. Compared to controls, the PD-group performed significantly poorer on two financial competence tasks and showed a comparable performance on the other financial capability measures. For 45% of the PD-group, cognitive test performance was indicative of mild cognitive impairment, yet no significant difference was observed in overall cognitive functioning between the PD and control group. In the total sample, only small or medium correlations were found between financial competence and cognition, and between financial capability and the contextual factors of income and financial experience. The findings suggest that in the earlier stages of PD, when cognitive impairments are relatively mild, some problems may be observed in financial competence, yet other domains of financial capability appear less affected. The absence of strong correlations between financial competence and overall cognitive functioning indicates that standard neuropsychological assessments seem inadequate to make financial capability determinations. By offering insight into the financial capability of people in the milder stages of PD, the findings of the present study may aid in the development and provision of tailored support.

Differential Cognitive Effects of Unilateral Subthalamic Nucleus Deep Brain Stimulation for Parkinson's Disease

OBJECTIVE

The aim of this study was to investigate the cognitive effects of unilateral directional versus ring subthalamic nucleus deep brain stimulation (STN DBS) in patients with advanced Parkinson's disease.

METHODS

We examined 31 participants who underwent unilateral STN DBS (left n = 17; right n = 14) as part of an National Institutes of Health (NIH)-sponsored randomized, double-blind, crossover study contrasting directional versus ring stimulation. All participants received unilateral DBS implants in the hemisphere more severely affected by motor parkinsonism. Measures of cognition included verbal fluency, auditory-verbal memory, and response inhibition. We used mixed linear models to contrast the effects of directional versus ring stimulation and implant hemisphere on longitudinal cognitive function.

RESULTS

Crossover analyses showed no evidence for group-level changes in cognitive performance related to directional versus ring stimulation. Implant hemisphere, however, impacted cognition in several ways. Left STN participants had lower baseline verbal fluency than patients with right implants (t [20.66 = -2.50, p = 0.02]). Verbal fluency declined after left (p = 0.013) but increased after right STN DBS (p < 0.001), and response inhibition was faster following right STN DBS (p = 0.031). Regardless of hemisphere, delayed recall declined modestly over time versus baseline (p = 0.001), and immediate recall was unchanged.

INTERPRETATION

Directional versus ring STN DBS did not differentially affect cognition. Similar to prior bilateral DBS studies, unilateral left stimulation worsened verbal fluency performance. In contrast, unilateral right STN surgery increased performance on verbal fluency and response inhibition tasks. Our findings raise the hypothesis that unilateral right STN DBS in selected patients with predominant right brain motor parkinsonism could mitigate declines in verbal fluency associated with the bilateral intervention. ANN NEUROL 2024;95:1205-1219.

The 2022 symposium on dementia and brain aging in low- and middle-income countries: Highlights on research, diagnosis, care, and impact

Two of every three persons living with dementia reside in low- and middle-income countries (LMICs). The projected increase in global dementia rates is expected to affect LMICs disproportionately. However, the majority of global dementia care costs occur in high-income countries (HICs), with dementia research predominantly focusing on HICs. This imbalance necessitates LMIC-focused research to ensure that characterization of dementia accurately reflects the involvement and specificities of diverse populations. Development of effective preventive, diagnostic, and therapeutic approaches for dementia in LMICs requires targeted, personalized, and harmonized efforts. Our article represents timely discussions at the 2022 Symposium on Dementia and Brain Aging in LMICs that identified the foremost opportunities to advance dementia research, differential diagnosis, use of neuropsychometric tools, awareness, and treatment options. We highlight key topics discussed at the meeting and provide future recommendations to foster a more equitable landscape for dementia prevention, diagnosis, care, policy, and management in LMICs. HIGHLIGHTS: Two-thirds of persons with dementia live in LMICs, yet research and costs are skewed toward HICs. LMICs expect dementia prevalence to more than double, accompanied by socioeconomic disparities. The 2022 Symposium on Dementia in LMICs addressed advances in research, diagnosis, prevention, and policy. The Nairobi Declaration urges global action to enhance dementia outcomes in LMICs.

Prevalence of and Annual Conversion Rates to Mild Cognitive Impairment and Dementia: Prospective, Longitudinal Study of an Essential Tremor Cohort

OBJECTIVE

Despite recent attention to cognitive impairment in essential tremor, few studies examine rates of conversion to diagnoses of mild cognitive impairment and dementia. Development of dementia in essential tremor is associated with loss of functional ability and a doubling of mortality rate. This prospective, longitudinal study comprehensively reports the prevalence and incidence of, and the annual rates of conversion to, mild cognitive impairment and dementia in an essential tremor cohort.

METHODS

Patients underwent detailed cognitive assessments and were assigned diagnoses of normal cognition, mild cognitive impairment, or dementia. There were 222 patients at baseline (mean age = 79.3 ± 9.7 years), and 177 patients participated in follow-up evaluations at 18, 36, 54, and 72 months (mean years of observation = 5.1 ± 1.7). Data were compared to those of historical controls and Parkinson disease patients.

RESULTS

The cumulative prevalence of dementia and average annual conversion rate of mild cognitive impairment to dementia were 18.5% and 12.2%, nearly three times higher than rates in the general population, and approximately one half the magnitude of those reported for Parkinson disease patients. The cumulative prevalence of mild cognitive impairment (26.6%) was almost double that of the general population, but less than that in Parkinson disease populations.

INTERPRETATION

We present the most complete exposition of the longitudinal trajectory of cognitive impairment in an essential tremor cohort yet presented. The prevalence of and conversion rates to dementia in essential tremor fall between those associated with the natural course of aging and the more pronounced rates observed in Parkinson disease. ANN NEUROL 2024;95:1193-1204.

Prediction of cognitive decline in Parkinson's disease based on MRI radiomics and clinical features: A multicenter study

OBJECTIVE

To develop and validate a multimodal combinatorial model based on whole-brain magnetic resonance imaging (MRI) radiomic features for predicting cognitive decline in patients with Parkinson's disease (PD).

METHODS

This study included a total of 222 PD patients with normal baseline cognition, of whom 68 had cognitive impairment during a 4-year follow-up period. All patients underwent MRI scans, and radiomic features were extracted from the whole-brain MRI images of the training set, and dimensionality reduction was performed to construct a radiomics model. Subsequently, Screening predictive factors for cognitive decline from clinical features and then combining those with a radiomics model to construct a multimodal combinatorial model for predicting cognitive decline in PD patients. Evaluate the performance of the comprehensive model using the receiver-operating characteristic curve, confusion matrix, F1 score, and survival curve. In addition, the quantitative characteristics of diffusion tensor imaging (DTI) from corpus callosum were selected from 52 PD patients to further validate the clinical efficacy of the model.

RESULTS

The multimodal combinatorial model has good classification performance, with areas under the curve of 0.842, 0.829, and 0.860 in the training, test, and validation sets, respectively. Significant differences were observed in the number of cognitive decline PD patients and corpus callosum-related DTI parameters between the low-risk and high-risk groups distinguished by the model (p < 0.05). The survival curve analysis showed a statistically significant difference in the progression time of mild cognitive impairment between the low-risk and the high-risk groups.

CONCLUSIONS

The building of a multimodal combinatorial model based on radiomic features from MRI can predict cognitive decline in PD patients, thus providing adaptive strategies for clinical practice.

Is PDQ-39 a reliable measure of quality of life of patients at advanced stages of Parkinson's disease considered for Deep Brain Stimulation

Purpose

Parkinson's disease (PD) significantly impedes, especially at its advanced stages, the health-related quality of life (QoL) of patients. The Parkinson's disease questionnaire (PDQ-39) is a widely-used measure assessing the impact of the disease on the patients' QoL. To date, the reliability of PDQ-39 has not been selectively evaluated for patients at a particular delineated stage of the PD progression. Against this backdrop, the study aimed firstly to evaluate comprehensively the internal consistency reliability of PDQ-39 and the constituent scales specifically for patients at the advanced stages of PD who were candidates for Deep Brain Stimulation (DBS) surgery, and secondly, to compare the Cronbach's alpha coefficients with those reported in other studies conducted with patients across all stages of the PD progression.

Methods

The sample included 36 Bulgarian patients (29 men and 7 women) at advanced stages of PD (Hoehn and Yahr stage 4), PD duration, M = 11.06, SD = 3.50). The internal consistency reliability of the questionnaire and the constituent scales was assessed using three criteria: Cronbach's alpha coefficients, inter-item and item-total correlations.

Results

The internal consistency reliability indicators were satisfactory for the entire instrument and for most of the scales and similar to those reported in previous studies. None of the scales had low internal consistency reliability results across the three criteria. Except for the Communication scale, seven of the eight scales had Cronbach's alpha values that were satisfactory or marginally below the cut off score. All scales had acceptable inter-item correlations. Three of the scales (Emotional Well-Being, Cognition and Communication) contained more than one item with non-satisfactory item-total correlations. With minor exceptions, the removal of the items with low item-total correlations either did not improve or improved marginally or even decreased the Cronbach's alpha coefficients of the respective scale. The Communication scale was the only scale with a Cronbach's alpha coefficient that was both low and comparatively different to other studies and had as well low item-total correlations for all constituent items, thus showing non-satisfactory results on two of the three internal consistency reliability estimates. In contrast, the Mobility scale met all three internal consistency reliability criteria.

Conclusion

PDQ-39 is a reliable tool for assessing the QoL of patients at advanced stages of PD across multiple health-related domains. The questionnaire can be recommended for inclusion in the best practice guidelines for evaluating DBS candidacy and the efficacy of DBS treatment for patients' QoL.

Does the Montreal Cognitive Assessment (MoCA) identify cognitive impairment profiles in Parkinson's disease? An exploratory study

An important proportion of patients with Parkinson's Disease (PD) present signs of cognitive impairment, although this is heterogeneous. In an attempt to classify this, the dual syndrome hypothesis distinguishes between two profiles: one defined by attentional and executive problems with damage in anterior cerebral regions, and another with mnesic and visuospatial alterations, with damage in posterior cerebral regions. The Montreal Cognitive Assessment (MoCA) is one of the recommended screening tools, and one of the most used, to assess cognitive impairment in PD. However, its ability to specifically identify these two profiles of cognitive impairment has not been studied. The aim of this study was, therefore, to analyze the capacity of the MoCA to detect cognitive impairment, and also to identify anterior and posterior profiles defined by the dual syndrome hypothesis. For this purpose, 59 patients with idiopathic PD were studied with the MoCA and a neuropsychological battery of tests covering all cognitive domains. Results of logistic regression analysis with ROC (Receiver Operating Characteristic) curves showed that MoCA detected cognitive impairment and identified patients with a profile of anterior/attentional and executive deficit, with acceptable sensibility and specificity. However, it did not identify patients with a posterior/mnesic-visuospatial impairment. We discuss the reasons for the lack of sensitivity of MoCA in this profile, and other possible implications of these results with regards the usefulness of this tool to assess cognitive impairment in PD.

Impact of Acute Dopamine Replacement on Cognitive Function in Parkinson's Disease

BACKGROUND

PD causes striatal dopaminergic denervation in a posterior/dorsal to anterior/ventral gradient, leaving motor and associative cortico-striato-pallido-thalamic loops differentially susceptible to hyperdopaminergic effects with treatment. As the choice and titration of symptomatic PD medications are guided primarily by motor symptoms, it is important to understand their cognitive implications.

OBJECTIVE

To investigate the effects of acute dopaminergic medication administration on executive function in Parkinson's disease (PD).

METHODS

Participants with idiopathic PD were administered the oral Symbol Digit Modalities Test (SDMT; n = 181) and the Stroop test (n = 172) in the off-medication and "best on" medication states. ANCOVA was used to test for differences between off-medication and on-medication scores corrected for age and years of education.

RESULTS

After administration of symptomatic medications, scores worsened on the SDMT (F = 11.70, P < 0.001, d = -0.13), improved on the Stroop color (F = 26.89, P < 0.001, d = 0.184), word (F = 6.25, P = 0.013, d = 0.09), and color-word (F = 13.22, P < 0.001, d = 0.16) test components, and the Stroop difference and ratio-based interference scores did not significantly change. Longer disease duration correlated with lower scores on the SDMT, Stroop color, word, and color-word scores; however, longer disease duration and higher levodopa-equivalents correlated with higher Stroop difference-based interference scores.

CONCLUSIONS

Symptomatic medication differentially affects performance on two cognitive tests in PD. After acute treatment, core Stroop measures improved, Stroop interference was unchanged, and SDMT performance worsened, likely reflecting complex changes in processing speed and executive function related to acute treatment. When considering motor symptom therapies in PD, an individual's cognitive demands and expectations, especially regarding executive function, should be considered.

Nonlinear Relationship Between Homocysteine and Mild Cognitive Impairment in Early Parkinson's Disease: A Cross-Sectional Study

Background

Cognitive impairment, a prevalent non-motor symptom in advanced Parkinson's disease (PD), has been associated with hyperhomocysteinemia, an important risk factor for PD progression and cognitive decline in PD. However, evidence regarding the association between homocysteine (Hcy) and cognitive function during early PD remains insufficient. Therefore, this study aims to examine the correlation between Hcy levels and cognitive function in the early stage of PD.

Methods

The study included 218 individuals in the early stages of PD who were consecutively admitted to the Suining Central Hospital Neurology Department. All the individuals completed the Parkinson's Disease Cognitive Rating Scale (PD-CDR). The Unified Parkinson's Disease Rating Scale part III (UPDRS-III) was employed for measuring the severity of motor symptoms, while the Hoehn-Yahr scale was used to measure the clinical symptom stage. Fasting venous blood samples were also drawn to measure the Hcy concentration, red blood cell folate, and vitamin B12.

Results

In this cross-sectional study, 47 (21.5%) patients with PD showed cognitive dysfunction. The serum Hcy levels were significantly higher in the cognitive impairment PD (PDCI) group compared with the cognitive normal PD group (P<0.001). The Generalized Additive Model (GAM) analysis revealed a nonlinear relationship between Hcy and the risk of PDCI. Multiple logistic regression analyses demonstrated a positive relationship between elevated Hcy and the risk of PDCI in the fully adjusted model ([OR]:3.1, 95% CI, 1.1-8.5, P=0.028). Segmented linear regression analysis showed that when Hcy levels were above 17.7 umol/l, the risk of PDCI increased by 1.6 times for every 1 unit elevated in Hcy (95% CI:1.1-2.2, P=0.008).

Conclusion

This study revealed a nonlinear positive correlation between the risk of PDCI and elevated serum Hcy levels in early PD patients, suggesting hyperhomocysteinemia as one of the treatable factors for cognitive impairment in the early stages of PD.

Neurocognitive Impairment and Social Cognition in Parkinson's Disease Patients

In addition to motor symptoms, neurocognitive impairment (NCI) affects patients with prodromal Parkinson's disease (PD). NCI in PD ranges from subjective cognitive complaints to dementia. The purpose of this review is to present the available evidence of NCI in PD and highlight the heterogeneity of NCI phenotypes as well as the range of factors that contribute to NCI onset and progression. A review of publications related to NCI in PD up to March 2023 was performed using PubMed/Medline. There is an interconnection between the neurocognitive and motor symptoms of the disease, suggesting a common underlying pathophysiology as well as an interconnection between NCI and non-motor symptoms, such as mood disorders, which may contribute to confounding NCI. Motor and non-motor symptom evaluation could be used prognostically for NCI onset and progression in combination with imaging, laboratory, and genetic data. Additionally, the implications of NCI on the social cognition of afflicted patients warrant its prompt management. The etiology of NCI onset and its progression in PD is multifactorial and its effects are equally grave as the motor effects. This review highlights the importance of the prompt identification of subjective cognitive complaints in PD patients and NCI management.

Effects of movement training based on rhythmic auditory stimulation in cognitive impairment: a meta-analysis of randomized controlled clinical trial

Objective

According to the World Alzheimer's Disease Report in 2015,there were 9.9 million new cases of dementia in the world every year. At present, the number of patients suffering from dementia in China has exceeded 8 million, and it may exceed 26 million by 2040.Mild cognitive impairment (MCI) refers to the pathological state of pre-dementia with the manifestation of the progressive decline of memory or other cognitive functions but without decline of activities of daily life. It is particularly important to prevent or prolong the development of MCI into dementia. Research showing effects of rhythmic auditory stimulation based-movement training(RASMT) interventions on cognitive function is also emerging. Therefore, the present meta-analysis briefly summarize findings regarding the impacts of RASMT programs on cognitive impairment.

Methods

Data from Pubmed, Embase, and Cochrane Library were utilized. The impact of RASMT on cognitive functions was evaluated using indicators such as overall cognitive status, memory, attention, and executive functions. The REVMAN5.3 software was employed to analyze bias risks integrated into the study and the meta-analysis results for each indicator.

Results

A total of 1,596 studies were retrieved, of which 1,385 non-randomized controlled studies and 48 repetitive studies were excluded. After reviewing titles and abstracts of the remaining 163 articles, 133 irrelevant studies were excluded, 30 studies were downloaded and read the full text. Among 30 articles, 18 articles that did not meet the inclusion criteria were excluded, the other 12 studies were included in this meta-analysis. Utilizing the Cochrane Collaborative Network Bias Risk Assessment Scale, it was found that 11 studies explained the method of random sequence generation, nine studies did not describe allocation concealment, four were single-blinded to all researchers, and eight reported single-blinding in the evaluation of experimental results. In the meta-analysis, the main outcomes showed statistically significant differences in overall cognitive status [MD = 1.19, 95%CI (0.09, 2.29), (p < 0.05)], attention [MD = -1.86, 95%CI (-3.53, -0.19), (p < 0.05)], memory [MD = 0.71, 95%CI (0.33, 1.09), (p < 0.01)], and executive function [MD = -0.23, 95% CI (-0.44, -0.02), (p < 0.05)]. Secondary outcomes indicated no statistically significant differences in verbal fluency [MD = -0.51, 95%CI (-1.30, 0.27), (p = 0.20)], while depression [MD = -0.29, 95% CI (-0.42, -0.16), (p < 0.01)] and anxiety [MD = 0.19, 95% CI (0.06, 0.32), (p < 0.01)] exhibited statistically significant differences. The GRADEpro GDT online tool assessed the quality of evidence for the outcome measures, revealing one low-quality outcome, two moderate-quality outcomes, and one high-quality outcome in this review.

Conclusion

This study shows that RASMT can improve the general cognitive status, memory, attention and executive function of patients with cognitive impairment. The quality of evidence revealed that MMSE was low, attention and memory were moderate, and executive function was high. The RAMST program (type of exercise: play percussion instruments; time of exercise: 30-60 min; frequency of exercise: 2-3 times/week; duration of exercise: more than 12 weeks) was proved to be more effective in improving cognitive function. However, the sample size is relatively insufficient, the future needs further study.

Systematic review registration

PROSPERO, identifier: CRD42023483561.

Gut microbiome is not associated with mild cognitive impairment in Parkinson's disease

Gut microbiome differences between people with Parkinson's disease (PD) and control subjects without Parkinsonism are widely reported, but potential alterations related to PD with mild cognitive impairment (MCI) have yet to be comprehensively explored. We compared gut microbial features of PD with MCI (n = 58) to cognitively unimpaired PD (n = 60) and control subjects (n = 90) with normal cognition. Our results did not support a specific microbiome signature related to MCI in PD.

Spontaneous brain activity in the hippocampal regions could characterize cognitive impairment in patients with Parkinson's disease

OBJECTIVE

This study aimed to investigate whether spontaneous brain activity can be used as a prospective indicator to identify cognitive impairment in patients with Parkinson's disease (PD).

METHODS

Resting-state functional magnetic resonance imaging (RS-fMRI) was performed on PD patients. The cognitive level of patients was assessed by the Montreal Cognitive Assessment (MoCA) scale. The fractional amplitude of low-frequency fluctuation (fALFF) was applied to measure the strength of spontaneous brain activity. Correlation analysis and between-group comparisons of fMRI data were conducted using Rest 1.8. By overlaying cognitively characterized brain regions and defining regions of interest (ROIs) based on their spatial distribution for subsequent cognitive stratification studies.

RESULTS

A total of 58 PD patients were enrolled in this study. They were divided into three groups: normal cognition (NC) group (27 patients, average MoCA was 27.96), mild cognitive impairment (MCI) group (21 patients, average MoCA was 23.52), and severe cognitive impairment (SCI) group (10 patients, average MoCA was 17.3). It is noteworthy to mention that those within the SCI group exhibited the most advanced chronological age, with an average of 74.4 years, whereas the MCI group displayed a higher prevalence of male participants at 85.7%. It was found hippocampal regions were a stable representative brain region of cognition according to the correlation analysis between the fALFF of the whole brain and cognition, and the comparison of fALFF between different cognitive groups. The parahippocampal gyrus was the only region with statistically significant differences in fALFF among the three cognitive groups, and it was also the only brain region to identify MCI from NC, with an AUC of 0.673. The paracentral lobule, postcentral gyrus was the region that identified SCI from NC, with an AUC of 0.941. The midbrain, hippocampus, and parahippocampa gyrus was the region that identified SCI from MCI, with an AUC of 0.926.

CONCLUSION

The parahippocampal gyrus was the potential brain region for recognizing cognitive impairment in PD, specifically for identifying MCI. Thus, the fALFF of parahippocampal gyrus is expected to contribute to future study as a multimodal fingerprint for early warning.

The Effect of Upright Stance and Vision on a Cognitive Task in Elderly Subjects and Patients with Parkinson's Disease

Standing compared to sitting enhances cognitive performance in healthy subjects. The effect of stance on cognitive performance has been addressed here in patients with Parkinson's disease (PwPD). We hypothesized that a simple cognitive task would be less enhanced in PwPD by standing with respect to sitting, because of a larger cognitive effort for maintenance of standing posture than in healthy subjects. We recruited 40 subjects (20 PwPD and 20 age-matched healthy subjects, HE). Each participant performed an arithmetic task (backward counting aloud by 7) in two postural states, sitting and standing, with eyes open (EO) and with eyes closed (EC). All trials lasted 60 s and were randomized across subjects and conditions. The number of correct subtractions per trial was an index of counting efficiency and the ratio of correct subtractions to total subtractions was an index of accuracy. All conditions collapsed, the efficiency of the cognitive task was significantly lower in PwPD than HE, whilst accuracy was affected to a lower extent. Efficiency significantly improved from sitting to standing in HE under both visual conditions whilst only with EO in PwPD. Accuracy was not affected by posture or vision in either group. We suggest that standing, compared to sitting, increases arousal, thus improving the cognitive performance in HE. Conversely, in PwPD this improvement was present only with vision, possibly due to their greater balance impairment with EC consuming an excess of attentional resources. These findings have implications for balance control and the risk of falling in PwPD in the absence of visual cues.

Exploring relevant factors of cognitive impairment in the elderly Chinese population using Lasso regression and Bayesian networks

Older adults are highly susceptible to developing cognitive impairment(CI). Various factors contribute to the prevalence of CI, but the potential relationships among these factors remain unclear. This study aims to explore the relevant factors associated with CI in Chinese older adults and analyze the potential relationships between CI and these factors.We analyzed the data on 6886 older adults aged≥60 from the China Health and Retirement Longitudinal Study (CHARLS) 2018. Lasso regression was initially used to screening variables. Bayesian Networks(BNs) were used to identify the correlates of CI and potential associations between factors. After screening with Lasso regression, 11 variables were finally included in the BNs. The BNs, by establishing a complex network relationship, revealed that age, education, and indoor air pollution were the direct correlates affecting the occurrence of CI in older adults. It also indicated that marital status indirectly influenced CI through age, and residence indirectly linked to CI through two pathways: indoor air pollution and education.Our findings underscore the effectiveness of BNs in unveiling the intricate network linkages among CI and its associated factors, holding promising applications. It can serve as a reference for public health departments to address the prevention of CI in the elderly.

Feasibility of Identifying Factors Related to Alzheimer's Disease and Related Dementia in Real-World Data

A comprehensive view of factors associated with AD/ADRD will significantly aid in studies to develop new treatments for AD/ADRD and identify high-risk populations and patients for prevention efforts. In our study, we summarized the risk factors for AD/ADRD by reviewing existing meta-analyses and review articles on risk and preventive factors for AD/ADRD. In total, we extracted 477 risk factors in 10 categories from 537 studies. We constructed an interactive knowledge map to disseminate our study results. Most of the risk factors are accessible from structured Electronic Health Records (EHRs), and clinical narratives show promise as information sources. However, evaluating genomic risk factors using RWD remains a challenge, as genetic testing for AD/ADRD is still not a common practice and is poorly documented in both structured and unstructured EHRs. Considering the constantly evolving research on AD/ADRD risk factors, literature mining via NLP methods offers a solution to automatically update our knowledge map.

The classical and non-classical axes of renin-angiotensin system in Parkinson disease: The bright and dark side of the moon

Parkinson disease (PD) is a common brain neurodegenerative disease due to progressive degeneration of the dopaminergic neurons in the substantia nigra pars compacta (SNpc). Of note, the cardio-metabolic disorders such as hypertension are adversely affect PD neuropathology through exaggeration of renin-angiotensin system (RAS). The RAS affects the stability of dopaminergic neurons in the SNpc, and exaggeration of angiotensin II (AngII) is implicated in the development and progression of PD. RAS has two axes classical including angiotensin converting enzyme (ACE)/AngII/AT1R, and the non-classical axis which include ACE2/Ang1-7/Mas receptor, AngIII, AngIV, AT2R, and AT4R. It has been shown that brain RAS is differs from that of systemic RAS that produce specific neuronal effects. As well, there is an association between brain RAS and PD. Therefore, this review aims to revise from published articles the role of brain RAS in the pathogenesis of PD focusing on the non-classical pathway, and how targeting of this axis can modulate PD neuropathology.

Social Cognition and Mild Cognitive Impairment in Mid-Stage Parkinson's Disease

Mild cognitive impairment (MCI) is a relevant non-motor feature in Parkinson's disease (PD). Social cognition (SC) is a cognitive domain that refers to the ability to decode others' intentions and to guide behavior in social contexts. We aimed to compare SC performance in mid-stage PD patients compared to a healthy population and according to their cognitive state. Fifty-two PD patients were classified as being cognitively normal (PD-CN) or having mild cognitive impairment (PD-MCI) following the Movement Disorder Society (MDS) Level II criteria. SC assessment included facial emotion recognition (FER), affective and cognitive theory of mind (ToM), and self-monitoring (RSMS test). Twenty-seven age-matched healthy controls (HC) were enrolled. PD-MCI patients scored worse than HC on affective and cognitive ToM task scores. Only cognitive ToM scores were significantly lower when compared with the PD-MCI and PD-CN groups. We found no differences in FER or self-monitoring performance. There were significant correlations between cognitive ToM and executive functions, memory, language, and attention, whereas FER and affective ToM correlated with memory. Our findings indicates that SC is normal in cognitively unimpaired and non-depressed mid-stage PD patients, whereas a decline in affective and cognitive ToM is linked to the presence of MCI.

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.

Subjective Cognitive Complaints in Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Subjective cognitive complaints (SCCs) in Parkinson's disease (PD) are reported frequently, but their prevalence and association with changes on objective testing are not fully known.

OBJECTIVE

We aimed to determine the prevalence, clinical correlates, and predictive value of SCCs in PD.

METHODS

We conducted a systematic review and meta-analysis. From 204 abstracts, we selected 31 studies (n = 3441 patients), and from these, identified the prevalence, clinical features, associations with neuropsychiatric symptoms, and predictive values of SCCs in PD.

RESULTS

The meta-analysis showed an SCC prevalence of 36%. This prevalence, however, was significantly moderated by study heterogeneity regarding female sex, disease severity, levodopa equivalent daily dosage, exclusion from the overall sample of patients with objective cognitive impairment, and measurement instrument. SCC prevalence did not differ between de novo and treated PD patients. SCCs were weakly and negligibly associated with cognitive changes on objective testing in cross-sectional studies. However, in cognitively healthy patients, SCCs had a risk ratio of 2.71 for later cognitive decline over a mean follow-up of 3.16 years. Moreover, SCCs were moderately related to co-occurring symptoms of depression, anxiety, or apathy and were more strongly related to these neuropsychiatric symptoms than objective cognitive functioning.

CONCLUSION

Our analyses suggest that SCCs in patients with and without objective cognitive impairment are frequent, occurring in more than one third of PD patients. Establishing uniform measurement instruments for identifying PD-related SCCs is critical to understand their implications. Even in cases lacking evidence of objective cognitive impairment and where SCCs might reflect underlying neuropsychiatric symptoms, the possibility of later cognitive deterioration should not be excluded. Therefore, SCCs in PD patients warrant close monitoring for opportunities for targeted and effective interventions. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Facial emotion expressivity in patients with Parkinson's and Alzheimer's disease

Parkinson's disease (PD) and Alzheimer's disease (AD) are neurodegenerative disorders with some overlapping clinical features. Hypomimia (reduced facial expressivity) is a prominent sign of PD and it is also present in AD. However, no study has experimentally assessed hypomimia in AD and compared facial expressivity between PD and AD patients. We compared facial emotion expressivity in patients with PD, AD, and healthy controls (HCs). Twenty-four PD patients, 24 AD patients and 24 HCs were videotaped during neutral facial expressions and while posing six facial emotions (anger, surprise, disgust, fear, happiness, and sadness). Fifteen raters were asked to evaluate the videos using MDS-UPDRS-III (item 3.2) and to identify the corresponding emotion from a seven-forced-choice response format. We measured the percentage of accuracy, the reaction time (RT), and the confidence level (CL) in the perceived accuracy of the raters' responses. We found the highest MDS-UPDRS 3.2 scores in PD, and higher in AD than HCs. When evaluating the posed expression captures, raters identified a lower percentage of correct answers in the PD and AD groups than HCs. There was no difference in raters' response accuracy between the PD and AD. No difference was observed in RT and CL data between groups. Hypomimia in patients correlated positively with the global MDS-UPDRS-III and negatively with Mini Mental State Examination scores. PD and AD patients have a similar pattern of reduced facial emotion expressivity compared to controls. These findings hold potential pathophysiological and clinical implications.

Patients with Parkinson's disease demonstrate deficits in visual-spatial memory in the Chinese Visual Retention Test

OBJECTIVE

We aimed to explore the existence of visual-spatial memory deficit in patients with Parkinson's disease (PD) without dementia in the Chinese Visual Retention Test, as well as to assess whether their performance is related to age, duration, severity, stage, and dopamine (DA) dose.

METHODS

Forty-two patients with PD and 30 healthy controls were included in our study. The Chinese Visual Retention Test was used to evaluate the visual-spatial memory of the subjects. Parameters of the Chinese Visual Retention Test were compared between the two groups. Correlation analysis and multiple linear regression analysis were used to explore the associations of the Chinese Visual Retention Test with age, duration, severity, stage of PD, and DA dose.

RESULTS

Three correct scores in the Chinese Visual Retention Test were all significantly lower in the PD group than in the control group. The total error scores, error scores of omissions, deformation, and persistence in the PD group were significantly higher than those in the control group. Correlation analysis showed the total error scores in the Chinese Visual Retention Test was positively correlated with UPDRS III score and H-Y classification. Multiple linear regression analysis showed that the total error scores in the Chinese Visual Retention Test were associated with the UPDRS III score and H-Y classification.

CONCLUSION

Patients with PD without dementia had visual-spatial memory deficits in the Chinese Visual Retention Test which may be affected by the severity and clinical stage of PD.

Diagnostic value of plasma SIRT1 levels and whole-brain gray matter volume in Parkinson's disease patients with cognitive impairment

OBJECTIVE

This study was designed to investigate the diagnostic value of plasma SIRT1 levels and whole-brain gray matter (GM) volume in Parkinson's disease (PD) patients with cognitive impairment.

METHODS

Automated enzymatic analysis was performed to measure plasma SIRT1 levels in 80 healthy controls and 77 PD patients. Motor symptoms and nonmotor symptoms in PD patients were assessed using the corresponding scales. A Siemens MAGNETOM Prisma 3 T MRI scanner was used to acquire images in 35 of 77 PD patients.

RESULTS

Plasma SIRT1 levels in PD patients were lower than those in healthy controls. Plasma SIRT1 levels were negatively correlated with the age, Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) scores, anxiety, depression, excessive daytime sleepiness (EDS), quality of life, and especially cognitive impairment. Thus, it showed that plasma SIRT1 levels were relevant to visuospatial/executive function, memory, and language. Receiver-operating characteristic (ROC) analysis confirmed that plasma SIRT1 levels had good diagnostic accuracy for PD with anxiety and EDS. Furthermore, plasma SIRT1 levels had a significant positive correlation with GM volume in the whole brain, and ROC analysis confirmed that plasma SIRT1 levels and the total GM volume had good diagnostic accuracy for PD with cognitive impairment.

CONCLUSIONS

This study showed that plasma SIRT1 levels were correlated with the nonmotor symptoms of anxiety, depression, EDS, and especially cognitive impairment as well as the total GM volume. Furthermore, the combination of plasma SIRT1 levels and the total GM volume had good diagnostic accuracy for PD with cognitive impairment.

Effects of stepped speech rehabilitation and psychological intervention on speech disorders and cognitive function in Parkinson disease patients

To examine the impact of stepwise speech rehabilitation exercise therapy in the treatment of patients with Parkinson speech problems under psychological intervention on clinical results and cognitive functioning. Parkinson speech disorder patients who met the inclusion criteria were selected and divided into a control group and an observation group for training respectively. The control group used conventional nursing methods, including training in orofacial movement, vocalization, pitch, volume and breath control. The observation group used stepwise speech rehabilitation exercise intervention combined with psychotherapy nursing programme. In the statistical analysis, independent sample t-test and chi-square test were used to test the significance of the data processing methods. In the statistical analysis of baseline functional level (P > .05). The difference was not statistically significant. After 7 weeks of training, the mFDA level and speech intelligibility increased in both the observation and control groups. From the situation analysis of "modified drinking test" and the comparison of UPDRS-I scores, it can be seen that dysphagia and Parkinson dysphasia were reduced in both groups after training. The observation group spontaneous speech dimension was greater than the control group by around 0.07 in the aphasia comparison. Both groups displayed an upward trend in their MMSE and Montreal Cognitive Assessment (MoCA) when measuring cognitive function; the evaluation of P300, constructive function, and quality of life revealed this. The observation group P300 potential score was 0.13 points higher than that of the control group. The therapeutic training of stepped speech rehabilitation exercise care combined with psychological intervention has significant nursing effects on patients with Parkinson disease speech disorders, and the patients' cognitive functions have been effectively improved.

Pathobiology of Cognitive Impairment in Parkinson Disease: Challenges and Outlooks

Cognitive impairment (CI) is a characteristic non-motor feature of Parkinson disease (PD) that poses a severe burden on the patients and caregivers, yet relatively little is known about its pathobiology. Cognitive deficits are evident throughout the course of PD, with around 25% of subtle cognitive decline and mild CI (MCI) at the time of diagnosis and up to 83% of patients developing dementia after 20 years. The heterogeneity of cognitive phenotypes suggests that a common neuropathological process, characterized by progressive degeneration of the dopaminergic striatonigral system and of many other neuronal systems, results not only in structural deficits but also extensive changes of functional neuronal network activities and neurotransmitter dysfunctions. Modern neuroimaging studies revealed multilocular cortical and subcortical atrophies and alterations in intrinsic neuronal connectivities. The decreased functional connectivity (FC) of the default mode network (DMN) in the bilateral prefrontal cortex is affected already before the development of clinical CI and in the absence of structural changes. Longitudinal cognitive decline is associated with frontostriatal and limbic affections, white matter microlesions and changes between multiple functional neuronal networks, including thalamo-insular, frontoparietal and attention networks, the cholinergic forebrain and the noradrenergic system. Superimposed Alzheimer-related (and other concomitant) pathologies due to interactions between α-synuclein, tau-protein and β-amyloid contribute to dementia pathogenesis in both PD and dementia with Lewy bodies (DLB). To further elucidate the interaction of the pathomechanisms responsible for CI in PD, well-designed longitudinal clinico-pathological studies are warranted that are supported by fluid and sophisticated imaging biomarkers as a basis for better early diagnosis and future disease-modifying therapies.

Mild cognitive impairment in patients with Parkinson´s disease and the analysis of associated factors

OBJECTIVES

This research targeted to understand the impact of clinical findings, non-motor symptoms, white matter hyperintensities (WMHs), and metabolic features on cognition in Parkinson's disease patients with mild cognitive impairment (PD-MCI).

METHODS

Sixty-one PD patients sundered into two groups: PD-MCI and normal cognition (PD-NC). We assessed cognition using Montreal Cognitive Assessment-TR (MoCA-TR) and Frontal Assessment Battery (FAB). We used the modified Hoehn&Yahr staging scale (mH&Y), Unified Parkinson's Disease Rating Scale (UPDRS), Freezing of Gait questionnaire, Beck Depression Inventory, Parkinson's disease sleep scale-2, Pittsburgh sleep quality index, Epworth sleepiness scale, and Non-motor symptoms questionnaire to evaluate all patients. We used the Fazekas scale to evaluate the WMHs and also investigated all laboratory parameters affecting cognitive functions.

RESULTS

Duration of disease, UPDRS-Motor part, age, disease stage, and daytime sleepiness were dramatically higher in the PD-MCI group than in PD-NC (p < 0.05). WMHs and homocysteine were higher in the PD-MCI group than in the controls (p = 0.016 and p < 0.001, respectively). There was a negative correlation between cognition and duration of disease, age, disease stage, UPDRS-Motor scale, daytime drowsiness, WMHs and homocysteine levels. Homocysteine was negatively related to visuospatial/executive functions (r=-0.303, p = 0.021). WMHs were correlated with global cognition (p =.000 r = .-542), language (p = .001, r = -.434), and delayed recall (p = .011, r = -.332).

DISCUSSION

Mild cognitive impairment is a widespread clinical situation of PD patients and often presents before the motor symptoms. Revealing curable causes that affect cognition before the development of PD-related dementia is crucial in controlling motor findings and reducing the burden of the caretakers.

Cognitive status and sleep quality can explain the fear of falling and fall history in people with Parkinson's disease

Fear of falling (FOF) is highly prevalent in people with Parkinson's disease (PwPD) and contributes to high fall risk. Studies reporting on the relationship between falls, FOF, and non-motor factors such as cognitive function and sleep quality in Parkinson's disease are limited. This study aimed to investigate (1) the relationship of cognitive function and sleep quality with FOF, and history of falls in PwPD; (2) differences in cognitive function and sleep quality between Parkinson's disease fallers and non-fallers; and (3) a cut-off score for cognitive function and sleep quality to discriminate Parkinson's disease fallers from non-fallers. Fifty PwPD were assessed for FOF [Falls Efficacy Scale-International (FES-I)], cognition [Montréal Cognitive Assessment (MOCA)], sleep quality [Pittsburgh Sleep Quality Index (PSQI)], and falls history. The MOCA is significantly associated with FES-I scores ( R2  = 0.429, P  < 0.0001). Both MOCA ( P  = 0.012) and PSQI ( P  = 0.027) were associated with falls history even after adjusting for confounding factors (age, sex, L-dopa use, Parkinson's disease severity). Both MOCA and PSQI scores were able to distinguish fallers from non-fallers with cut-off scores of 15.5 and 7.5, respectively. Although our findings revealed that both cognitive function and sleep quality are important factors influencing falls and FOF in PwPD, it remains to be determined if addressing cognitive impairments and poor sleep quality may favorably impact balance before integrating such screenings into fall prevention programs.

Original research: initial development of a pragmatic tool to estimate cognitive decline risk focusing on potentially modifiable factors in Parkinson's disease

Introduction

Cognitive decline is common in Parkinson's disease (PD). Calculating personalized risk of cognitive decline in PD would allow for appropriate counseling, early intervention with available treatments, and inclusion in disease-modifying trials.

Methods

Data were from the Parkinson's Progression Markers Initiative de novo cohort. Baseline scores were calculated for Lifestyle for Brain Health (LIBRA) and the Montreal Parkinson Risk of Dementia Scale (MoPaRDS) per prior literature and preliminary Parkinson's disease Risk Estimator for Decline In Cognition Tool (pPREDICT) by attributing a point for fourteen posited risk factors. Baseline and 5-year follow-up composite cognitive scores (CCSs) were calculated from a neuropsychological battery and used to define cognitive decliners (PD-decline) versus maintainers (PD-maintain).

Results

The PD-decline group (n = 44) had higher LIBRA (6.76 ± 0.57, p < 0.05), MoPaRDS (2.45 ± 1.41, p < 0.05) and pPREDICT (4.52 ± 1.66, p < 0.05) scores compared to the PD-maintain group (n = 263; LIBRA 4.98 ± 0.20, MoPaRDS 1.68 ± 1.16, pPREDICT 3.38 ± 1.69). Area-under-the-curve (AUC) for LIBRA was 0.64 (95% confidence interval [CI], 0.55-0.73), MoPaRDS was 0.66 (95% CI, 0.58-0.75) and for pPREDICT was 0.68 (95% CI, 0.61-0.76). In linear regression analyses, LIBRA (p < 0.05), MoPaRDS (p < 0.05) and pPREDICT (p < 0.05) predicted change in CCS. Only age stratified by sex (p < 0.05) contributed significantly to the model for LIBRA. Age and presence of hallucinations (p < 0.05) contributed significantly to the model for MoPaRDS. Male sex, older age, excessive daytime sleepiness, and moderate-severe motor symptoms (all p < 0.05) contributed significantly to the model for pPREDICT.

Conclusion

Although MoPaRDS is a PD-specific tool for predicting cognitive decline relying on only clinical features, it does not focus on potentially modifiable risk factors. LIBRA does focus on potentially modifiable risk factors and is associated with prediction of all-cause dementia in some populations, but pPREDICT potentially demonstrates improved performance in cognitive decline risk calculation in individuals with PD and may identify actionable risk factors. As pPREDICT incorporates multiple potentially modifiable risk factors that can be obtained easily in the clinical setting, it is a first step in developing an easily assessable tool for a personalized approach to reduce dementia risk in people with PD.

Analyses of correct responses and errors on measures of verbal fluency among Parkinson's disease and essential tremor patients

Objective: Parkinson's disease (PD) and essential tremor (ET) involve neuroanatomical circuitry that impact frontal lobe functioning, via the striatum and cerebellum, respectively. The aim of this exploratory study was to investigate quantitative and qualitative performance between and within these groups on measures of verbal fluency. Method: Sixty-three PD and 53 ET patients completed neuropsychological testing. Linear regression models with robust variance estimation compared verbal fluency performance between groups related to correct responses and errors. Paired t-tests investigated within group error rates. Results: PD patients gave more correct responses for phonological (β ̂   =5.3, p=.01) and category fluency (β ̂   =4.1, p=.01) than ET patients; however, when processing speed was added as a covariate, this attenuated performance on both measures and only phonological fluency remained significant (β ̂   =4.0, p=.04). There were no statistical differences in error scores between groups. Error rates within groups suggested that PD patients had higher error rates in total errors and perseveration errors on phonological fluency (M = 2.6, p=.00; M = 1.6, p=.00) and higher total errors and set-loss error rates on category switching (M = 5.1, p<.001; M = 4.1, p<.001). ET patients had higher error rate with relation to total errors and set-loss errors on phonological fluency (M = 2.5, p=.00; M = 1.5, p=.02) and category switching (M = 3.9, p=,00; M = 3.9, p<.001). Conclusions: PD patients performed better than ET patients on phonological fluency. PD patients appear to make more perseveration errors on phonological fluency, while ET patients made more set-loss errors. Implications for frontal lobe dysfunction and clinical impact are discussed.

Validity and diagnostics of the Italian version of the Montreal Cognitive Assessment (MoCA) in non-demented Parkinson's disease patients

BACKGROUND

This study aimed at: (1) assessing, in an Italian cohort of non-demented Parkinson's disease (PD) patients, the construct validity of the Montreal Cognitive Assessment (MoCA) against both first- and second-level cognitive measures; (2) delivering an exhaustive and updated evaluation of its diagnostic properties.

METHODS

A retrospective cohort of N = 237 non-demented PD patients having been administered the MoCA was addressed, of whom N = 169 further underwent the Mini-Mental State Examination (MMSE) and N = 68 the Parkinson's Disease Cognitive Rating Scale (PD-CRS). A subsample (N = 60) also underwent a second-level cognitive battery encompassing measures of attention/executive functioning, language, memory, praxis and visuo-spatial abilities. Construct validity was assessed against both the PD-CRS and the second-level cognitive battery. Diagnostics were tested via receiver-operating characteristics analyses against a below-cut-off MMSE score.

RESULTS

The MoCA was associated with both PD-CRS scores (p < .001) and the vast majority of second-level cognitive measures (ps < .003). Both raw and adjusted MoCA scores proved to be highly accurate to the aim of identifying patients with MMSE-confirmed cognitive dysfunctions. A MoCA score adjusted for age and education according to the most recent normative dataset and < 19.015 is herewith suggested as indexing cognitive impairment in this population (AUC = .92; sensitivity = .92; specificity = .80).

DISCUSSION

The Italian MoCA is a valid and diagnostically sound screener for global cognitive inefficiency in non-demented PD patients. Further studies are nevertheless needed that confirm its diagnostic values against a measure other than the MMSE.

Comparison of core and process scores on the California Verbal Learning Test-3 for Parkinson's disease and essential tremor patients

INTRODUCTION

Parkinson's disease (PD) and essential tremor (ET) are two disorders known to lead to executive dysfunction, presumably through distinct pathways to the frontal lobes via the striatum or cerebellum, respectively. Memory functioning in PD and ET patients has been previously suggested to be adversely impacted by executive dysfunction. The aims of this exploratory study were to compare memory performance between and within groups on the California Verbal Learning Test - 3 (CVLT-3) through the analysis of core and process scores and to understand the relationship of these scores with measures of executive functioning.

METHOD

Seventy PD and 54 ET patients completed comprehensive neuropsychological testing. Independent sample t-tests or Mann-Whitney tests were used to compare between group core and process scores on the CVLT-3. Within-subjects analyses were conducted via Wilcoxon Signed Rank Test due to nonparametric data. Spearman's correlations were conducted to explore the relationship between memory process scores and measures of executive functioning.

RESULTS

The ET and PD samples were similar with regard to age, education, gender, and general cognitive functioning. PD patients made more repetition errors (U = 2391.50, p = .01) than ET patients and Normal Memory PD patients made more repetition errors than Low Memory PD patients (U= 711.00, p= .00). Correlational analyses revealed repetition errors were negatively associated with tests of inhibition, set shifting, and working memory (rs = -.293, -.232). ET patients demonstrated a preference for a serial cluster learning strategy (T = 861.00, p = .005), similar to PD patients (T= 1633.00, p = <.001).

CONCLUSIONS

The study revealed presence of higher repetition errors in the PD sample that was demonstrated to have a negative relationship with measures of executive functioning. Implications for investigating process ("qualitative") scores in memory performance to determine extent of executive involvement are discussed.

Physiotherapy Approach to a Stage V Parkinson's Disease Patient: A Case Report

Parkinson's disease (PD) is a neurodegenerative disorder caused due to decreased dopamine, a neurotransmitter, advancing to a range of motor and non-motor attributes. There is a death of dopamine-producing neurons (dopaminergic neurons) in the Substantia Nigra. Bradykinesia, postural instability, resting tremor, and rigidity are four main symptoms in this patient. A variety of other symptoms, like hypomimia, micrographia, freezing gait, decreased movement amplitude, constipation, cognitive impairments, etc., can be seen in this patient. In this paper, we report a 62-year-old female with stage 5 PD with chief complaints of uncoordinated movements, weakness, and difficulty in daily activities. She was treated with strengthening, stretching, Lee Silverman Voice Treatment (LSVT) BIG, bed mobility, gait training with auditory cueing, balance training, etc. LSVT-BIG enhances motor function by incorporating high amplitude motions of high intensity, consisting of numerous repetitions and progressive complexity. At the end of three weeks, the patient had improved strength, static and dynamic balance, gait, and quality of life.

Comparative Efficacy, Safety, and Acceptability of Pimavanserin and Other Atypical Antipsychotics for Parkinson's Disease Psychosis: Systematic Review and Network Meta-Analysis

BACKGROUND

The current comparative efficacy, safety, and acceptability of atypical antipsychotics (AAPs) in treating Parkinson's Disease Psychosis (PDP) are not entirely understood.

OBJECTIVE

To evaluate comparative efficacy, safety, and acceptability of AAPs in patients with PDP.

METHODS

We conducted a systematic review and a network meta-analysis to compare the efficacy, safety, and acceptability of pimavanserin, quetiapine, olanzapine, clozapine, ziprasidone, and risperidone. We estimated relative standardized mean differences (SMDs) for continuous outcomes and odds ratios (OR) for binary outcomes, with their respective 95% confidence intervals (CIs).

RESULTS

We included 19 unique studies evaluating AAPs in a total of 1,242 persons with PDP. Based on Clinical Global Impression Scale for Severity, pimavanserin (SMD, -4.81; 95% CI, -5.39, -4.24) and clozapine (SMD, -4.25; 95% CI, -5.24, -3.26) significantly improved symptoms compared with placebo. Also, compared to placebo, pimavanserin (OR, 1.16; 95% CI, 1.07, 1.24) significantly improved psychotic symptoms based on Scale for Assessment of Positive Symptoms for Parkinson's Disease Psychosis/Hallucinations and Delusions scores. In comparison to placebo, clozapine (SMD, -0.69; 95% CI, -1.35, -0.02), pimavanserin (SMD, -0.01; 95% CI, -0.56, 0.53), and quetiapine (SMD, 0.00; 95% CI, -0.68, 0.69) did not impair motor function per Unified Parkinson's Disease Rating scale. Based on Mini-Mental State Examination scale, quetiapine (SMD, 0.60; 95% CI, 0.07, 1.14) significantly impaired cognition compared to placebo.

CONCLUSIONS

In patients with PDP, pimavanserin and clozapine demonstrated significant improvement in psychosis without affecting motor function. With quetiapine being associated with a significant decline in cognition and despite not impairing motor function, our findings suggest that it should be avoided in patients with PDP and reduced cognitive abilities.

Exploring depression in Parkinson's disease: an Italian Delphi Consensus on phenomenology, diagnosis, and management

BACKGROUND

Depression is a prodromic and a frequent non-motor symptom of Parkinson's disease, associated to reduced quality of life and poor outcomes. The diagnosis of depression in parkinsonian patients represents a challenge due to the overlapping of symptoms typical of the two conditions.

METHODS

A Delphi panel survey was performed to reach a consensus amongst different Italian specialists on four main topics: the neuropathological correlates of depression, main clinical aspects, diagnosis, and management of depression in Parkinson's disease.

RESULTS AND CONCLUSION

Experts have recognized that depression is an established risk factor of PD and that its anatomic substrate is related to the neuropathological abnormalities typical of the disease. Multimodal and SSRI antidepressant have been confirmed as a valid therapeutic option in the treatment of depression in PD. Tolerability, safety profile, and potential efficacy on broad spectrum of symptoms of depression including cognitive symptoms and anhedonia should be considered when selecting an antidepressant and the choice should be tailored on the patients' characteristics.

Gut Microbial Metabolome and Dysbiosis in Neurodegenerative Diseases: Psychobiotics and Fecal Microbiota Transplantation as a Therapeutic Approach-A Comprehensive Narrative Review

The comprehensive narrative review conducted in this study delves into the mechanisms of communication and action at the molecular level in the human organism. The review addresses the complex mechanism involved in the microbiota-gut-brain axis as well as the implications of alterations in the microbial composition of patients with neurodegenerative diseases. The pathophysiology of neurodegenerative diseases with neuronal loss or death is analyzed, as well as the mechanisms of action of the main metabolites involved in the bidirectional communication through the microbiota-gut-brain axis. In addition, interventions targeting gut microbiota restructuring through fecal microbiota transplantation and the use of psychobiotics-pre- and pro-biotics-are evaluated as an opportunity to reduce the symptomatology associated with neurodegeneration in these pathologies. This review provides valuable information and facilitates a better understanding of the neurobiological mechanisms to be addressed in the treatment of neurodegenerative diseases.

Effectiveness of music-based interventions for cognitive rehabilitation in Parkinson's disease: a systematic review of randomized controlled clinical trials

BACKGROUND

Music-based interventions are promising for cognitive rehabilitation in Parkinson's disease; however, systematic reviews covering the topic are scarce.

OBJECTIVE

To analyze the effectiveness of music-based interventions for cognitive rehabilitation in PD.

METHOD

Systematic review study based on PRISMA criteria. The descriptors Parkinson's disease, Parkinson's disease, idiopathic Parkinson's disease, music-based interventions, music therapy, music training, auditory stimulation, music, rhythm, rhythmic, cognition, and cognitive were used. Five databases were searched PubMed/MEDLINE, PsycInfo, Scopus, Web of Science, and Cochrane in May 2022. Only randomized controlled trials with no limit on publication date or language were included. Risk of bias was assessed following Cochrane Collaboration criteria for development of systematic intervention reviews.

RESULTS

Nine hundred nineteen articles were found by the descriptors; 266 were excluded for being repeated; 650 for not meeting the inclusion criteria. The remaining three articles were included and analyzed. The interventions consisted of practices with emphasis on rhythm and were conducted in groups. Risks of important biases were observed, such as lack of blinding in the allocation of participants and in the assessment of outcomes, as well as incomplete data for some outcomes.

CONCLUSION

Overall, the results showed no evidence of efficacy of music-based interventions for cognitive outcomes in PD.

Memory Phenotypes In Early, De Novo Parkinson's Disease Patients with Mild Cognitive Impairment

BACKGROUND

Memory deficits in mild cognitive impairment related to Parkinson's disease (PD-MCI) are quite heterogeneous, and there is no general agreement on their genesis.

OBJECTIVES

To define memory phenotypes in de novo PD-MCI and their associations with motor and non-motor features and patients' quality of life.

METHODS

From a sample of 183 early de novo patients with PD, cluster analysis was applied to neuropsychological measures of memory function of 82 patients with PD-MCI (44.8%). The remaining patients free of cognitive impairment were considered as a comparison group (n = 101). Cognitive measures and structural magnetic resonance imaging-based neural correlates of memory function were used to substantiate the results.

RESULTS

A three-cluster model produced the best solution. Cluster A (65.85%) included memory unimpaired patients; Cluster B (23.17%) included patients with mild episodic memory disorder related to a "prefrontal executive-dependent phenotype"; Cluster C (10.97%) included patients with severe episodic memory disorder related to a "hybrid phenotype," where hippocampal-dependent deficits co-occurred with prefrontal executive-dependent memory dysfunctions. Cognitive and brain structural imaging correlates substantiated the findings. The three phenotypes did not differ in terms of motor and non-motor features, but the attention/executive deficits progressively increased from Cluster A, through Cluster B, to Cluster C. This last cluster had worse quality of life compared to others.

CONCLUSIONS

Our results demonstrated the memory heterogeneity of de novo PD-MCI, suggesting existence of three distinct memory-related phenotypes. Identification of such phenotypes can be fruitful in understanding the pathophysiological mechanisms underlying PD-MCI and its subtypes and in guiding appropriate treatments. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Evaluation of Temporomandibular Joint in Patients with Parkinson's Disease: A Comparative Study

(1) The aim of this study was to perform an evaluation of the temporomandibular joint (TMJ) in patients with Parkinson's disease (PD) and present the morphological differences of the TMJ between healthy subjects and patients with PD. (2) A total of 102 Caucasian subjects were divided equally into two groups. The study group consisted of patients with PD, while the control group comprised healthy subjects. Ten parameters, including anterior joint space (AJS), superior joint space (SJS), posterior joint space (PJS), condyle head length (CHL), condylar neck width (CNW), minor axis of the condyle (MAC), long axis of the condyle (LAC), condylar axis inclination (CI), medial joint space (MJS), and lateral joint space (LJS), were measured using magnetic resonance images. The data were statistically analyzed using paired samples t-test and Student's t-test, with a significance level set at p < 0.05. (3) In the PD group, all TMJ parameters showed a statistically significant difference between both sides of the face (p < 0.05). However, in the control group, AJS, SJS, PJS, CHL, CNW, MAC, CI, MJS, and LJS did not show a statistically significant difference between both sides of the face (p > 0.05), except for LAC (p < 0.05). The asymmetry index values of AJS, SJS, PJS, CHL, CNW, MAC, CI, MJS, and LJS demonstrated a statistically significant difference between the study and control groups (p < 0.05), except for LAC (p > 0.05). (4) Within the limitations of this retrospective study, the findings suggest that TMJ morphology and asymmetry could be associated with PD.