Evidence map›Paper›PMID 40956987›Full record

ArticleNeurology2025

Association of DTI-ALPS Glymphatic Index With Differential Phenoconversion in Isolated REM Sleep Behavior Disorder: A Multi-Cohort MRI Study.

Violette Ayral, Alexandre Pastor-Bernier, Véronique Daneault, Christina Tremblay, Marie Filiatrault, Celine Haddad, Jean-François Gagnon, Ronald B Postuma, Petr Dušek, Stanislav Marecek and 9 more

Abstract readMulticenter Study
In one paragraph

Article in Neurology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers.

0numbers the graph read from it
0cells of the map it votes in
9citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

9 citing papers in PubMed.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

19 authors.

Violette AyralCentre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, CIUSSS du Nord-de-l'Île-de-Montréal, Quebec, Canada.
Alexandre Pastor-BernierCentre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, CIUSSS du Nord-de-l'Île-de-Montréal, Quebec, Canada.
Véronique DaneaultCentre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, CIUSSS du Nord-de-l'Île-de-Montréal, Quebec, Canada.
Christina TremblayCentre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, CIUSSS du Nord-de-l'Île-de-Montréal, Quebec, Canada.
Marie FiliatraultCentre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, CIUSSS du Nord-de-l'Île-de-Montréal, Quebec, Canada.
Celine HaddadCentre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, CIUSSS du Nord-de-l'Île-de-Montréal, Quebec, Canada.
Jean-François GagnonCentre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, CIUSSS du Nord-de-l'Île-de-Montréal, Quebec, Canada.ORCID 0000-0003-1132-0563
Ronald B PostumaCentre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, CIUSSS du Nord-de-l'Île-de-Montréal, Quebec, Canada.ORCID 0000-0002-6468-4734
Petr DušekDepartment of Neurology and Centre of Clinical Neurosciences, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czechia.ORCID 0000-0003-4877-9642
Stanislav MarecekDepartment of Neurology and Centre of Clinical Neurosciences, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czechia.
Zsoka VargaDepartment of Neurology and Centre of Clinical Neurosciences, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czechia.
Johannes C KleinOxford Parkinson's Disease Centre and Division of Neurology, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom.
Michele T HuOxford Parkinson's Disease Centre and Division of Neurology, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom.ORCID 0000-0001-6382-5841
Stéphane LehéricySorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Assistance Publique Hôpitaux de Paris, INSERM 1127, CNRS 7225, France; and.
Isabelle ArnulfSorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Assistance Publique Hôpitaux de Paris, INSERM 1127, CNRS 7225, France; and.ORCID 0000-0002-2240-2516
Marie VidailhetSorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Assistance Publique Hôpitaux de Paris, INSERM 1127, CNRS 7225, France; and.ORCID 0000-0002-2409-9143
Jean-Christophe CorvolSorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Assistance Publique Hôpitaux de Paris, INSERM 1127, CNRS 7225, France; and.ORCID 0000-0001-7325-0199
ICEBERG Study Group
Shady RahayelCentre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal, CIUSSS du Nord-de-l'Île-de-Montréal, Quebec, Canada.ORCID 0000-0001-5786-3278

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

BACKGROUND AND

objectivesIsolated REM sleep behavior disorder (iRBD) is the strongest prodromal marker of synucleinopathies, including Parkinson disease (PD) and dementia with Lewy bodies (DLB). Identifying brain biomarkers that predict progression and distinguish phenoconversion trajectories remains a challenge. The glymphatic system is involved in interstitial waste clearance, and its dysfunction has been associated with pathologic protein accumulation and neurodegeneration. Diffusion tensor imaging along the perivascular space (DTI-ALPS) has been proposed as a noninvasive proxy for glymphatic function. The aim of this study was to determine whether patients with iRBD show a reduced DTI-ALPS index compared with controls and whether a lower DTI-ALPS index predicts future phenoconversion to PD or DLB.

methodsWe conducted a longitudinal, multicenter cohort study using brain MRI scans from patients with polysomnography-confirmed iRBD and healthy controls recruited across 5 international centers. All participants underwent T1-weighted and diffusion-weighted MRI. DTI-ALPS indices were computed from diffusivity along projection and associative fibers adjacent to the lateral ventricles. The primary outcome was time to phenoconversion to synucleinopathy. Linear models assessed baseline group differences and clinical correlates, and Cox proportional hazard models assessed the predictive value of DTI-ALPS for time to phenoconversion.

resultsA total of 250 patients with iRBD (mean age: 66.5 ± 6.8 years; 87% male) and 178 controls (65.7 ± 6.8 years; 81% male) were included. Patients with iRBD showed a lower left DTI-ALPS index compared with controls (mean difference = -0.034, 95% CI -0.067 to -0.001; DISCUSSION: Patients with iRBD exhibit a reduced DTI-ALPS index, suggesting altered glymphatic function. This reduction was associated with future phenoconversion to PD, supporting the DTI-ALPS index as a potential prognostic MRI biomarker of progression in prodromal synucleinopathies.

Indexed as

BrainDiffusion Tensor ImagingGlymphatic SystemREM Sleep Behavior DisorderAgedCohort StudiesDisease ProgressionFemaleHumansLewy Body DiseaseLongitudinal StudiesMagnetic Resonance ImagingMaleMiddle AgedParkinson DiseasePolysomnography

Identifiers

PMID40956987
PMCPMC12456434

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Registered trials

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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.