Journal of Parkinson's disease最新文献

{"title":"Leveraging machine learning with real-world data for hypothesis generation by identifying exposomic predictors in Parkinson's disease among farmers.","authors":"Pascal Petit, François Berger, Vincent Bonneterre, Nicolas Vuillerme","doi":"10.1177/1877718X261453798","DOIUrl":"10.1177/1877718X261453798","url":null,"abstract":"<p><p>BackgroundMachine learning offers new avenues for complementing traditional epidemiological approaches by analyzing routinely collected, population-based administrative health data.ObjectiveThis study aimed to identify potential exposomic predictors (hypothesis generation) for Parkinson's disease (PD) across the entire French agricultural workforce.MethodsWe applied XGBoost adapted for Cox proportional hazards modeling to assess approximately 180 exposomic factors derived from nationwide administrative health data within the TRACTOR project. Shapley Additive Explanation (SHAP) values were used to assess the importance of each predictor. To provide both model-based and statistical perspectives, SHAP analysis was complemented with classical Cox regression, allowing for transparent assessment of each predictor's contribution to the model and its statistical association with survival. Sensitivity analyses incorporating different exposure lags were conducted. The study included 424,725 farm managers (6,265 PD cases) and 544,788 farmworkers (2,848 PD cases) aged 50+, analyzed separately due to differences in available variables and coding structures.ResultsSeveral occupational factors, including duration of involvement in crop farming and viticulture, emerged as key promoting predictors, surpassing age in predictive importance. Beyond conventional predictors such as type 2 diabetes, less conventional predictors were identified, including work diversification, seasonal employment, hypercholesterolemia, epilepsy, antidepressant use, anxiolytic use, and antibiotic use.ConclusionsThese results contribute to a growing body of evidence supporting the integration of occupational health considerations into PD research and highlight the importance of exploring and identifying potential farming-related risk factors in PD development.Plain language summary title<b>Using nationwide French farming data and machine learning to explore potential factors linked to Parkinson's disease. This study investigates how work-related and health-related factors may contribute to Parkinson's disease risk among farm managers and farmworkers</b>.</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1174-1190"},"PeriodicalIF":5.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13442685/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148653753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulatory endorsement for the application of α-synuclein seed amplification assay as a susceptibility and risk biomarker for clinical trials targeting synucleinopathies.","authors":"Diane Stephenson, Luis Concha-Marambio, Tom Lanz, Kalpana Merchant, Kathrin Brockmann, Nicholas King, Laura Carrillo, Anne Pedata, Harsha Kocherla, Samantha J Hutten","doi":"10.1177/1877718X261463936","DOIUrl":"10.1177/1877718X261463936","url":null,"abstract":"<p><p>Transformation in the neurosciences in biomarkers is enabling novel therapeutic strategies targeting earlier stages of disease prior to onset of clinical symptoms. Emerging progress in the area of synucleinopathies, including Parkinson's disease (PD) and dementia with Lewy bodies (DLB) have significant implications for clinical trials. Misfolded α-synuclein aggregates (syn-seeds) propagate by templated misfolding of native α-synuclein, driving disease spread. The advent of the α-synuclein seed amplification assay (syn SAA) now enables highly sensitive and specific detection of syn-seeds in cerebrospinal fluid (CSF), allowing in vivo identification of underlying α-synuclein pathology, including in individuals prior to the onset of motor symptoms.To support regulatory alignment, the Critical Path Institute's Critical Path for Parkinson's (CPP) consortium compiled and evaluated the totality of scientific evidence in the area of syn SAA as an in vivo measure of misfolded alpha synuclein in CSF and submitted it to the U.S. Food and Drug Administration (FDA) in a request for a Biomarker Letter of Support (LoS). Within three months of submission, the FDA issued a LoS endorsing CSF syn SAA as a susceptibility and risk biomarker for use in clinical trials targeting α-synuclein-related neurodegenerative diseases, enabling enrichment of participants with underlying pathology and reducing trial risk. These data have enabled the development of biological classification frameworks for synucleinopathies that define disease based on molecular pathology rather than clinical symptoms alone.This review summarizes the regulatory-grade evidence supporting syn SAA and discusses its implications for biologically driven clinical trial design and early-intervention strategies.</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1296-1312"},"PeriodicalIF":5.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148579105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low vs high frequency deep brain stimulation for Parkinson's disease-associated motor symptoms: A systematic review and meta-analysis of randomized control trials.","authors":"Bilal Salman, Lea Aridi, Vivian Faour, Wissam Abou Ali, Bilal Al Halabi, Rima Haidar, Jihane Soueid, Feten Fekih-Romdhane, Souheil Hallit, Sami Azar, Frederic Harb","doi":"10.1177/1877718X261481663","DOIUrl":"10.1177/1877718X261481663","url":null,"abstract":"<p><p>PurposeDeep brain stimulation (DBS) is an established treatment for motor symptoms in Parkinson's Disease (PD), but the optimal stimulation frequency remains uncertain. Previous studies have suggested that low and high frequency DBS may produce different clinical effects. This study aimed to compare the effects of low versus high frequency DBS on motor outcomes in PD.MethodsA systematic review and meta-analysis of randomized controlled trials was conducted. PubMed, Ovid, CINAHL, Clinicaltrials.gov and the Cochrane Library were searched from 2010 to November 26, 2025. Studies comparing low and high frequency DBS in patients with PD were included. Motor outcomes were pooled using a random-effects model, and subgroup analyses were performed based on age and disease duration.ResultsA total of 15 randomized controlled trials involving 416 participants were included. Overall, no significant difference in motor outcomes was observed between low and high frequency DBS. Subgroup analysis based on age showed no significant effect modification. However, subgroup analysis suggested greater improvement with high frequency DBS in patients with shorter disease duration, whereas no significant difference was observed in those with longer disease duration. Sensitivity analyses demonstrated that these findings were robust. Additionally, tremor improvement favored the use of HFDBS.ConclusionHigh and low frequency DBS appear to provide comparable overall motor benefit in PD. Stimulation frequency may have differential effects depending on disease duration, although these findings should be interpreted cautiously. Further prospective trials are needed to determine optimal programming strategies across disease stages.RegistrationThis study was registered on PROSPERO (CRD420251238009).</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1877718X261481663"},"PeriodicalIF":5.9,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13518612/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148829468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impaired olfaction and Parkinsonism: A \"hidden gem\" in the neurological literature.","authors":"Grace V Chen, Peter A LeWitt","doi":"10.1177/1877718X261477916","DOIUrl":"10.1177/1877718X261477916","url":null,"abstract":"<p><p>Though impaired olfaction in Parkinson disease is now a widely accepted characteristic of this disorder, this discovery arose from several international case reports preceding the first formal research on this topic (conducted in 1975 by Ansari and Johnson). The clinical observations have supplemented findings by Braak and colleagues demonstrating that, like impaired sense of smell, olfactory bulb involvement by Lewy pathology is a common early feature in Parkinson disease.</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1877718X261477916"},"PeriodicalIF":5.9,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13518606/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148829488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serotonin content and uptake in platelets can distinguish Parkinson's disease from control patients and essential tremor.","authors":"Pablo Montenegro, Carolina H Javier, Daniel Pereda, Rosalía González-Brito, Jesús N Lorenzo, Mercedes Pueyo, Ricardo Borges","doi":"10.1177/1877718X261462339","DOIUrl":"10.1177/1877718X261462339","url":null,"abstract":"<p><p>We have demonstrated that platelets from Parkinson's disease patients exhibit impaired serotonin uptake and release. This seems to be caused by a dysfunction in secretory vesicles (SecVs), which share the mechanisms of accumulation with dopaminergic neurons. As a working hypothesis, this dysfunction may create an excess of dopamine causing neurotoxicity a process absent in other conditions like Essential Tremor or Essential Tremor Plus. The serotonin functional analysis in platelets is a potential tool to reduce misdiagnosis.To validate this, we performed a functional study using liquid chromatography (UHPLC) to analyze serotonin content, uptake, and secretion in platelets from 50 Parkinson's disease patients, 23 essential tremor, 17 essential tremor plus, and 50 controls.Parkinson's disease patients show impaired platelet serotonin content and uptake <i>vs</i>. Controls (<i>P</i> < 0.001), essential tremor (<i>P</i> < 0.01) and essential tremor plus (<i>P</i> < 0.05), ANOVA. Notably, no significant differences were found between controls and essential tremor nor essential tremor plus; although, essential tremor plus manifested mild serotonin storage dysfunction.Platelet serotonin dysfunction reflects distinct pathological origins between Parkinson's disease and other tremor syndromes, suggesting that platelet serotonin analysis is a viable and objective tool for differential diagnosis between Parkinson's disease and tremor syndromes.</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1877718X261462339"},"PeriodicalIF":5.9,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13518608/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148829483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetic-rest tremor dominance for differentiating dystonic tremor from Parkinson's disease.","authors":"Takashi Tsuboi, Takashi Uematsu, Miki Hashida, Yoshiki Ito, Keito Sawada, Moeka Higuchi, Tomotaka Ishizaki, Takahiko Tsugawa, Satoshi Maesawa, Kenshiro Fuse, Yuki Saito, Taiki Fukushima, Daigo Tamakoshi, Keita Hiraga, Masashi Suzuki, Ryuta Saito, Adolfo Ramirez-Zamora, Christopher W Hess, Michael S Okun, Masahisa Katsuno","doi":"10.1177/1877718X261470294","DOIUrl":"10.1177/1877718X261470294","url":null,"abstract":"<p><p>BackgroundDifferentiating dystonic tremor (DT) from Parkinson's disease (PD) remains challenging, particularly when dystonic signs are subtle, and DT is a major contributor to scans without evidence of dopaminergic deficit. Although dopamine transporter imaging can support the distinction, it is costly and not universally accessible. Simple diagnostic indicators less reliant on subjective clinical interpretation are needed.MethodsIn a dopamine transporter imaging-supported cohort (n = 102; DT, 51; PD, 51), we used accelerometry to characterize ordinal patterns of tremor amplitude across rest, postural, and kinetic (spiral drawing) conditions. Candidate ordinal rules were evaluated, and the rule with the highest classification accuracy was selected for subsequent blinded visual assessment by three raters within the same cohort.ResultsAccelerometry showed greater kinetic tremor amplitude in DT and greater rest tremor amplitude in PD, whereas postural tremor amplitude did not differ significantly between groups. Among candidate ordinal rules, the pairwise comparison of kinetic versus rest tremor amplitude achieved the highest overall diagnostic performance for identifying DT (90% sensitivity, 85% specificity, 88% accuracy). Blinded visual classification of this rule showed excellent inter-rater agreement (Fleiss' κ = 0.92), high concordance with accelerometer-based classification (Cohen's κ = 0.86), and 90% sensitivity, 88% specificity, and 89% accuracy.ConclusionsA simple visual comparison of tremor amplitude during spiral drawing versus at rest required no specialized equipment and showed high reproducibility in blinded ratings. Although probabilistic and requiring validation in independent cohorts, this approach may serve as a practical bedside adjunct for distinguishing DT from PD.</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1877718X261470294"},"PeriodicalIF":5.9,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13506976/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global research synergy: Advancing fundamental Parkinson's research through international collaboration.","authors":"Jesus Gutierrez-Arratia, Paula Saffie-Awad, Artur F Schuh, Mario Cornejo-Olivas","doi":"10.1177/1877718X261478730","DOIUrl":"10.1177/1877718X261478730","url":null,"abstract":"<p><p>BackgroundThe remarkable advances achieved in Parkinson's disease (PD) research across clinical science, genetics, molecular and cellular mechanisms, disease modeling, pathophysiology, biomarkers, and therapeutics reflect not only scientific innovation but also the evolution of collaborative research. The field has transitioned from single-investigator observations and isolated institutional efforts to regional networks and global consortia that now drive many of the most important PD discoveries.ObjectiveTo review the evolution of collaborative research approaches in PD, examine barriers and challenges to global research synergy, and discuss potential solutions to promote equitable and impactful international collaboration.State of the Art and Future DirectionsKey challenges to global PD research include funding inequities, regulatory and data-sharing complexities, difficulties in standardization and generalizability, language barriers, limited interdisciplinary communication, unequal resource allocation, insufficient training opportunities, regional mistrust, and the need to address diverse cultural contexts. Successful international initiatives have demonstrated the value of shared databases, harmonized protocols, cross-border funding mechanisms, and synergistic multidisciplinary, multicultural, and multinational partnerships. Future efforts should be grounded in trust, transparency, ethical reciprocity, equitable governance, and meaningful stakeholder engagement, while prioritizing capacity building, workforce development, and sustainable training opportunities.ConclusionsAccelerating progress in PD research requires collaborative frameworks that integrate diverse populations, disciplines, institutions, and regions. Strengthening research infrastructure, community engagement, culturally grounded education, participant-centered research practices, and scientific leadership, particularly in low- and middle-income countries, will be essential to ensure that all populations can contribute to and benefit from scientific advances, fostering a more equitable and effective global PD research ecosystem.</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1877718X261478730"},"PeriodicalIF":5.9,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13498691/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148794556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association of handgrip strength asymmetry with prodromal and incident Parkinson's disease: A prospective cohort study.","authors":"Min Cai, Xiao Chen, Sheng Zhuang, Yaqi Li, Fan Chen, Xiang Gao","doi":"10.1177/1877718X261479507","DOIUrl":"https://doi.org/10.1177/1877718X261479507","url":null,"abstract":"<p><p>BackgroundAsymmetry symptoms are well recognized in Parkinson's disease (PD). However, whether handgrip strength (HGS) asymmetry can prospectively predict incident PD remains unknown.ObjectivesTo prospectively examine the association between HGS asymmetry and subsequent risk of incident PD<b>.</b>MethodsIncluded were 497,100 participants without PD at baseline from the UK Biobank. HGS asymmetry index was calculated by dividing the absolute inter-hand difference in HGS by the average HGS of the two hands. The primary outcome was incident PD identified through hospital admissions, death registries, and self-reported data. As secondary outcome, prodromal PD was defined as the presence of ≥3 out of 8 prodromal PD features assessed through self-reported data, hospital admission records and primary care data. The associations were evaluated using Cox regression models. Several lag analyses were conducted to examine how many years in advance could HGS asymmetry predict incident PD.ResultsDuring a median follow-up of over 13 years, 2868 participants developed PD. HGS asymmetry (highest vs. lowest quartile) was associated with higher risk of developing PD (HR = 1.23; 95% CI: 1.10, 1.37) (<i>P-</i>_trend < 0.001). Lag analysis suggested that HGS asymmetry could even predict incident PD in 8 years. Significant association between HGS asymmetry and prodromal PD risk was also observed. The significant associations between HGS asymmetry and PD risk persisted when further excluding those with low HGS or prodromal PD.ConclusionsHigher HGS asymmetry was associated with a higher risk of incident PD, suggesting the potential of HGS asymmetry as an early indicator for PD.</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1877718X261479507"},"PeriodicalIF":5.9,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148794597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rehabilitation strategies for atypical parkinsonian syndromes: A scoping review of progressive supranuclear palsy, multiple system atrophy, corticobasal syndrome, and dementia with Lewy bodies.","authors":"Hikaru Kamo, Satoru Amano, Isabelle K Gerzenshtein, Dinesh K Vuddandam, Koichi Nagaki, Mai Shimizu, My-Vy Tran, Arunmozhimaran Elavarasi, Nikolaus R McFarland, Aparna Wagle Shukla","doi":"10.1177/1877718X261440430","DOIUrl":"10.1177/1877718X261440430","url":null,"abstract":"<p><p>BackgroundRehabilitation plays a crucial role in maintaining function and independence in neurodegenerative disorders. However, evidence on its effectiveness in atypical parkinsonian syndromes including progressive supranuclear palsy (PSP), multiple system atrophy (MSA), corticobasal syndrome (CBS), and dementia with Lewy bodies (DLB) remains fragmented.ObjectiveThis scoping review aimed to comprehensively map the literature on rehabilitation interventions for PSP, MSA, CBS, and DLB, summarize intervention types and outcomes, and identify research gaps.MethodsFollowing PRISMA-ScR guidelines, we searched PubMed, Embase, Web of Science, and Cochrane Library from inception to May 2025. Eligible studies included peer-reviewed English-language reports on non-invasive rehabilitation such as physical, occupational, and speech therapy. Two independent reviewers screened titles, abstracts, and full texts, with disagreements resolved by consensus or a third reviewer.ResultsSixty studies met inclusion criteria: PSP (<i>n</i> = 32), MSA (<i>n</i> = 20), CBS (<i>n</i> = 5), and DLB (<i>n</i> = 6). Across disorders, rehabilitation was consistently safe and feasible. Gait and balance training, voice and swallowing therapy, and multimodal programs demonstrated short-term benefits in mobility, speech, and quality of life (Class III-IV based on American Academy of Neurology classification).ConclusionsWhile rehabilitation may offer functional benefits across atypical parkinsonian syndromes, high-quality evidence remains limited. This analysis highlights significant gaps in care and underscores the need for early, multidisciplinary, and disease-specific interventions to support mobility and safety. Standardized outcome measures and long-term trials are essential to establish sustained efficacy.</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1877718X261440430"},"PeriodicalIF":5.9,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13490323/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148794627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence, predictors, and emerging biomarkers for cognitive impairment and neuropsychiatric manifestations in Parkinson's disease in Africa: A systematic review.","authors":"Mundih Noelar Njohjam, Falonne Tiffany Niakam, Mark Olivier Ngoule","doi":"10.1177/1877718X261479269","DOIUrl":"https://doi.org/10.1177/1877718X261479269","url":null,"abstract":"<p><p>BackgroundCognitive impairment and neuropsychiatric manifestations are common disabling non-motor symptoms that can negatively impact quality of life in Parkinson's disease. This review aimed to critically appraise and synthesize evidence on the prevalence, predictors, and emerging biomarkers of cognitive impairment and neuropsychiatric manifestations among patients with Parkinson's disease in Africa.MethodsWe conducted a systematic review of studies reporting cognitive and neuropsychiatric outcomes among individuals with Parkinson's disease in African populations, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We used the Critical Appraisal Skills Program checklist to determine the quality of the included studies. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to estimate the certainty of the evidence.ResultsA total of 32 studies, including 3687 patients, were analyzed. The prevalence of cognitive impairment ranged from 21.6% to 92%. Depression was the most common neuropsychiatric symptom (up to 81.7%). Consistent predictors of cognitive impairment included older age, advanced disease, and greater motor severity<b>.</b> Importantly, APOE ε4 homozygosity was associated with a twofold increase in the risk of cognitive impairment, while findings on LRRK2 G2019S mutations were heterogeneous across populations. Additionally, hypocalcemia and retinal nerve fiber layer thinning were linked to worse cognitive outcomes. Functional neuroimaging studies revealed altered emotional processing, with enhanced activation of limbic and cortical networks in response to positive emotional stimuli.ConclusionsEvidence from this review suggests that cognitive impairment and neuropsychiatric manifestations are common in African PD populations and may be associated with clinical, genetic, metabolic, and neurobiological factors, although the quality of the evidence is low. Larger, community-based, and longitudinal studies are warranted.</p>","PeriodicalId":16660,"journal":{"name":"Journal of Parkinson's disease","volume":" ","pages":"1877718X261479269"},"PeriodicalIF":5.9,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13476375/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148759593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}