Evidence map›Paper›PMID 42234173›Full record

Observational studyJournal of neurology2026

Stage-specific polysomnographic and MRI markers across phenoconversion in isolated REM sleep behavior disorder.

Jungyon Yum, Eun Hwa Kim, Dongjin Seo, Joonho Kim, Woo-Seok Ha, Min Kyung Chu, Won-Joo Kim, Soomi Cho, Kyung Min Kim

Abstract readObservational Study
PubMed Publisher
In one paragraph

Observational study in Journal of neurology, 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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0citing papers in PubMed
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1 · What the graph read from it

What it found

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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

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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5 · Who and what money

Authors and funding

9 authors.

Jungyon YumDepartment of Neurology, Yongin Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.ORCID http://orcid.org/0000-0002-6722-512X
Eun Hwa KimBiostatistics Collaboration Unit, Department of Biomedical Systems Informatics, Yonsei University College of Medicine, Seoul, Republic of Korea.
Dongjin SeoDepartment of Neurology, Severance Hospital, Yonsei University College of Medicine, 50-1, Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea.
Joonho KimDepartment of Neurology, Severance Hospital, Yonsei University College of Medicine, 50-1, Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea.ORCID http://orcid.org/0000-0001-9020-8195
Woo-Seok HaDepartment of Neurology, Severance Hospital, Yonsei University College of Medicine, 50-1, Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea.ORCID http://orcid.org/0000-0003-1188-449X
Min Kyung ChuDepartment of Neurology, Severance Hospital, Yonsei University College of Medicine, 50-1, Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea.ORCID http://orcid.org/0000-0001-6221-1346
Won-Joo KimDepartment of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.ORCID http://orcid.org/0000-0002-5850-010X
Soomi ChoDepartment of Neurology, Severance Hospital, Yonsei University College of Medicine, 50-1, Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea. soomicho@yuhs.ac.ORCID http://orcid.org/0000-0003-4723-8975
Kyung Min KimDepartment of Neurology, Severance Hospital, Yonsei University College of Medicine, 50-1, Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea.ORCID http://orcid.org/0000-0002-0261-1687

Funding

Korea Health Industry Development Institute RS-2024-00440131
6 · The paper itself

Abstract

objectivesTo identify stage-specific neurophysiological and structural markers across non-converted isolated rapid eye movement (REM) sleep behavior disorder (iRBD), phenoconverted iRBD, and established α-synucleinopathy.

methodsWe retrospectively analyzed 86 patients who underwent video-polysomnography (PSG) and magnetic resonance imaging (MRI), classified at baseline as iRBD or established α-synucleinopathy, with longitudinal follow-up to define non-converted (n = 27), phenoconverted iRBD (n = 25), alongside established α-synucleinopathy (n = 34). Pairwise comparisons assessed stage-specific differences, followed by multivariable logistic regression to identify discriminative features. Trend analyses and Cox models evaluated progressive changes and predictors of phenoconversion.

resultsCompared with non-converters, phenoconverted iRBD showed PSG abnormalities, including higher NREM arousal and periodic limb movements and lower REM-apnea-hypopnea index (AHI), without structural differences. In contrast, α-synucleinopathy showed widespread cortical and limbic atrophy with PSG abnormalities, including reduced N2 sleep and elevated NREM arousal index and heart rate. Logistic regression identified higher NREM arousal index (odds ratio [OR] = 1.08, p = 0.005) and lower REM-AHI (OR = 0.94, p = 0.006) as predictors of phenoconversion. α-Synucleinopathy was distinguished from non-converters by left cingulate and hippocampal atrophy, reduced REM-AHI, and elevated NREM heart rate. Trend analyses demonstrated progressive cortical and limbic atrophy from non-converted iRBD to phenoconverted iRBD and established α-synucleinopathy. In Cox models, lower left cingulate cortex volume (hazard ratio [HR] = 0.77 per IQR, p = 0.018) and higher NREM arousal index (HR = 1.03, p = 0.010) predicted shorter time to phenoconversion.

conclusionsPSG and MRI capture distinct but complementary, stage-dependent processes in iRBD, with PSG reflecting early functional alterations and MRI indexing progressive neurodegeneration, supporting a stage-aware multimodal approach to risk stratification for α-synucleinopathy.

Indexed as

Magnetic Resonance ImagingPolysomnographyREM Sleep Behavior DisorderSleep StagesSynucleinopathiesAgedCerebral CortexDisease ProgressionFemaleFollow-Up StudiesHumansLongitudinal StudiesMaleMiddle AgedRetrospective StudiesMRIPhenoconversionPSGRBDα-Synucleinopathy

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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.