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Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study
Postuma RB, Iranzo A, Hu M, Högl B, Boeve BF, Manni R, Oertel WH, Arnulf I et al.. Brain : a journal of neurology, 2019-03-01
Topic: Risk, prevention and care in population studies
The overall conversion rate from iRBD to an overt neurodegenerative syndrome was 6.3% per year, with 73.5% converting after 12-year follow-up. The rate of phenoconversion was significantly increased with abnormal quantitative motor testing [hazard ratio (HR) = 3.16], objective motor examination (HR = 3.03), olfactory deficit (HR = 2.62), mild cognitive impairment (HR = 1.91-2.37), erectile dysfunction (HR = 2.13), motor symptoms (HR = 2.11), an abnormal DAT scan (HR = 1.98), colour vision abnormalities (HR = 1.69), constipation (HR = 1.67), REM atonia loss (HR = 1.54), and age (HR = 1.54). There was no significant predictive value of sex, daytime somnolence, insomnia, restless legs syndrome, sleep apnoea, urinary dysfunction, orthostatic symptoms, depression, anxiety, or hyperechogenicity on substantia nigra ultrasound. Among predictive markers, only cognitive variables were different at baseline between those converting to primary dementia versus parkinsonism. Our findings provide estimates of the relative predictive value of prodromal markers, which can be used to stratify patients for neuroprotective trials.
Key findings
- The overall conversion rate from iRBD to an overt neurodegenerative syndrome was 6.3% per year, with 73.5% converting after 12-year follow-up.
- The rate of phenoconversion was significantly increased with abnormal quantitative motor testing [hazard ratio (HR) = 3.16], objective motor examination (HR = 3.03), olfactory deficit (HR = 2.62), mild cognitive impairment (HR = 1.91-2.37), erectile dysfunction (HR = 2.13), motor symptoms (HR = 2.11), an abnormal DAT scan (HR = 1.98), colour vision abnormalities (HR = 1.69), constipation (HR = 1.67), REM atonia loss (HR = 1.54), and age (HR = 1.54).
- There was no significant predictive value of sex, daytime somnolence, insomnia, restless legs syndrome, sleep apnoea, urinary dysfunction, orthostatic symptoms, depression, anxiety, or hyperechogenicity on substantia nigra ultrasound.
- Among predictive markers, only cognitive variables were different at baseline between those converting to primary dementia versus parkinsonism.
- Our findings provide estimates of the relative predictive value of prodromal markers, which can be used to stratify patients for neuroprotective trials.
Why it matters
In this multicentre study, people with idiopathic REM sleep behaviour disorder converted to an overt neurodegenerative syndrome at 6.3% per year, with 73.5% converting after 12-year follow-up, and several markers predicted conversion. The findings are presented as a way to stratify patients for future neuroprotective trials, not as a treatment or cure.
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Study details
- Participants1,280
- Effect size82.5%; 6.3%; 73.5%
- Evidence strengthModerate
How this study scored 73/100
Published in a leading specialty journal. Scored zero for study design and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Brain : a journal of neurology) |
| Journal's citation record | 4 / 4 | Brain: journal h-index 503 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2019 — within 10 year(s) of the newest study here |
| Sample size | 3 / 4 | 1,280 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 7 / 7 | Cited 1,118 times (OpenAlex, 2026-10-10) |
| Citations per year | 5 / 5 | 124.2 citations a year over 9 year(s) since 2019 |
| Impact for its field and year | 6 / 6 | Cited 65.4× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 22 other studies in this library |
| Still being cited | 4 / 4 | Cited 512 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Amélie Pelletier: h-index 32 (OpenAlex, whole career) |
| Institution's track record | 3 / 3 | Harvard University: institution h-index 3,235 (OpenAlex) |
| Multi-centre collaboration | 3 / 3 | OpenAlex lists 42 institution(s) in 11 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 30789229) |
| Free to read | 2 / 2 | Free to read |
| Total | 73 / 100 | — |
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Read the original
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Postuma, R. B., Iranzo, A., Hu, M., Högl, B., Boeve, B. F., Manni, R., et al. (2019). Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study. Brain : a journal of neurology. https://doi.org/10.1093/brain/awz030
Vancouver
Postuma RB, Iranzo A, Hu M, Högl B, Boeve BF, Manni R, et al. Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study. Brain : a journal of neurology. 2019. doi:10.1093/brain/awz030. PMID: 30789229.
BibTeX
@article{postuma2019-30789229,
author = {Postuma, R. B. and Iranzo, A. and Hu, M. and Högl, B. and Boeve, B. F. and Manni, R. and Oertel, W. H. and Arnulf, I. and others},
title = {{Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study}},
journal = {Brain : a journal of neurology},
year = {2019},
doi = {10.1093/brain/awz030},
pmid = {30789229},
url = {https://doi.org/10.1093/brain/awz030}
}
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