Evidence map›Paper›PMID 41788046›Full record

ArticleMovement disorders clinical practice2026

Alzheimer's Biomarkers and Visuospatial Cognition in Parkinson's Disease: Modification by α-Synuclein and Mediation of Age Effects.

David Ledingham, Sahana Sathyanarayana, Charlotte B Stewart, Robyn Iredale, Victoria Foster, Debra Galley, Meher Lad, Mark R Baker, Nicola Pavese

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Article in Movement disorders clinical practice, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

9 authors.

David LedinghamClinical Ageing Research Unit, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.ORCID https://orcid.org/0000-0002-6474-2666
Sahana SathyanarayanaClinical Ageing Research Unit, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
Charlotte B StewartClinical Ageing Research Unit, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
Robyn IredaleClinical Ageing Research Unit, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
Victoria FosterClinical Ageing Research Unit, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
Debra GalleyClinical Ageing Research Unit, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
Meher LadNeurosciences, Newcastle Upon Tyne NHS Foundation Trust, Newcastle upon Tyne, UK.
Mark R BakerNeurosciences, Newcastle Upon Tyne NHS Foundation Trust, Newcastle upon Tyne, UK.
Nicola PaveseClinical Ageing Research Unit, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.ORCID https://orcid.org/0000-0002-6801-6194

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundVisuospatial deficits in Parkinson's disease (PD) often precede dementia and complicate daily functioning. Alzheimer's disease (AD) pathology and α-synuclein aggregation frequently co-occur in PD, but their combined impact on cognition is unclear.

objectivesTo examine whether AD biomarker burden relates to visuospatial performance in PD, whether this effect differs by α-synuclein status, and whether AD biomarkers mediate age-related decline.

methodsWe analyzed 416 participants from the Parkinson's Progression Markers Initiative. AD biomarker burden was indexed by the cerebrospinal fluid pTau181/Aβ42 ratio; α-synuclein aggregation was assessed using seed amplification assay. Models adjusted for age, sex, education, and motor severity. Sensitivity analyses included genetic stratification and subgroup exclusion.

resultsHigher AD biomarker burden was associated with poorer visuospatial performance and delayed recall. In participants with concurrent biomarker data (n = 246), AD burden interacted with α-synuclein status to predict worse visuospatial outcomes, with the greatest impairment observed in individual's positive for both biomarkers. Mediation analysis indicated that AD biomarker burden accounts for approximately 10-14% of the age effect on visuospatial performance.

conclusionsAD and α-synuclein biomarkers show associations consistent with synergistic effects on visuospatial cognition in PD. These findings are exploratory and require replication in pre-specified independent cohorts. However, if validated, testing both biomarkers could help identify individuals at higher risk of early visuospatial decline and inform hypothesis-driven stratification in future clinical trials.

Indexed as

alpha-SynucleinAlzheimer DiseaseParkinson DiseaseSpace PerceptionAgedAged, 80 and overAmyloid beta-PeptidesBiomarkersDisease ProgressionFemaleHumansMaleMiddle AgedPeptide Fragmentstau Proteinsalpha-SynucleinAmyloid beta-Peptidesamyloid beta-protein (1-42)BiomarkersPeptide Fragmentstau ProteinsAlzheimer's diseasebiomarkersParkinson's diseasepTau181/Aβ42 ratioseeding amplification assay (SAA)visuospatial cognition

Identifiers

PMID41788046
PMCPMC13339541

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.