Evidence map›Paper›PMID 33682731›Full record

SynthesisJournal of Parkinson's disease2021

Parkinson's Disease Subtypes: Critical Appraisal and Recommendations.

Tiago A Mestre, Seyed-Mohammad Fereshtehnejad, Daniela Berg, Nicolaas I Bohnen, Kathy Dujardin, Roberto Erro, Alberto J Espay, Glenda Halliday, Jacobus J van Hilten, Michele T Hu and 14 more

Abstract readSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Journal of Parkinson's disease, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 91 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
91citing papers in PubMed, 1 pooled it
–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

91 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Article
  3. Article
  4. AMPLITUDE PERFORMANCE SUBTYPES IN PARKINSON'S DISEASE.medRxiv : the preprint server for health sciences · 2026
    Article
  5. Article
  6. A transdiagnostic structural brain signature of Parkinsonian and Essential Tremor.Journal of neural transmission (Vienna, Austria : 1996) · 2026
    Article
  7. Article
  8. Article
  9. Article
  10. Article
  11. Review
  12. Article
  13. Article
  14. Article
  15. Article
  16. Review
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  19. Review
  20. Article

31 more citing papers are in PubMed but not listed here.

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

24 authors.

Tiago A MestreParkinson's disease and Movement Disorders Center, Division of Neurology, Department of Medicine, The Ottawa Hospital Research Institute, The University of Ottawa Brain and Research Institute, Ottawa, ON, Canada.
Seyed-Mohammad FereshtehnejadDivision of Neurology, Department of Medicine, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Daniela BergDepartment of Neurology, Christian-Albrechts-University, Kiel, Germany.
Nicolaas I BohnenDepartments of Radiology & Neurology, University of Michigan, University of Michigan Udall Center, Ann Arbor VAMC, Ann Arbor, MI, USA.
Kathy DujardinMovement Disorders Department, Center of Excellence for Neurodegenerative Diseases LiCEND, Lille, France.
Roberto ErroDepartment of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", Neuroscience Section, University of Salerno, Baronissi (SA), Italy.
Alberto J EspayJames J. and Joan A. Gardner Family Center for Parkinson's Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, USA.
Glenda HallidayBrain and Mind Centre and Central Clinical School, Faculty of Medicine and Health, University of Sydney, Australia.
Jacobus J van HiltenDepartment of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
Michele T HuNuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Neurology Department, Oxford, United Kingdom.
Beomseok JeonDepartment of Neurology, Seoul National University Hospital, Seoul, Korea.
Christine KleinInstitute of Neurogenetics, University of Luebeck, Luebeck, Germany.
Albert F G LeentjensDepartment of Psychiatry, Maastricht University Medical Center, Maastricht, The Netherlands.
Johan MarinusDepartment of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
Brit MollenhauerParacelsus-Elena-Klinik, Kassel and University Medical Center Goettingen, Department of Neurology, Kassel, Germany.
Ronald PostumaDepartment of Neurology, McGill University, Montreal, Quebec, Canada.
Rajasumi RajalingamEdmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, University Health Network, Toronto, Canada.
Mayela Rodríguez-ViolanteNational Institute of Neurology and Neurosurgery, Mexico City, Mexico.
Tanya SimuniFeinberg School of Medicine, Northwestern University, Chicago, IL, USA.
D James SurmeierDepartment of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Daniel WeintraubDepartments of Psychiatry and Neurology, Perelman School of Medicine at the University of Pennsylvania; Parkinson's Disease Research, Education and Clinical Center (PADRECC), Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA.
Michael P McDermottDepartment of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, NY, USA.
Michael LawtonPopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom.
Connie MarrasEdmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, University Health Network, Toronto, Canada.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundIn Parkinson's disease (PD), there is heterogeneity in the clinical presentation and underlying biology. Research on PD subtypes aims to understand this heterogeneity with potential contribution for the knowledge of disease pathophysiology, natural history and therapeutic development. There have been many studies of PD subtypes but their impact remains unclear with limited application in research or clinical practice.

objectiveTo critically evaluate PD subtyping systems.

methodsWe conducted a systematic review of PD subtypes, assessing the characteristics of the studies reporting a subtyping system for the first time. We completed a critical appraisal of their methodologic quality and clinical applicability using standardized checklists.

resultsWe included 38 studies. The majority were cross-sectional (n = 26, 68.4%), used a data-driven approach (n = 25, 65.8%), and non-clinical biomarkers were rarely used (n = 5, 13.1%). Motor characteristics were the domain most commonly reported to differentiate PD subtypes. Most of the studies did not achieve the top rating across items of a Methodologic Quality checklist. In a Clinical Applicability Checklist, the clinical importance of differences between subtypes, potential treatment implications and applicability to the general population were rated poorly, and subtype stability over time and prognostic value were largely unknown.

conclusionSubtyping studies undertaken to date have significant methodologic shortcomings and most have questionable clinical applicability and unknown biological relevance. The clinical and biological signature of PD may be unique to the individual, rendering PD resistant to meaningful cluster solutions. New approaches that acknowledge the individual-level heterogeneity and that are more aligned with personalized medicine are needed.

Indexed as

Parkinson DiseaseHumansPrecision MedicinePrognosisheterogeneityParkinson’s diseasesubtypes

Identifiers

PMID33682731
PMCPMC8150501

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

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.