Evidence map›Paper›PMID 42831418›Full record

ArticleMovement disorders clinical practice2026

Defining the Clinical Phenotypic Ground Truth: Expert Interrater Agreement in Hyperkinetic Movement Disorders.

Madelein van der Stouwe, Olof Vermeulen, Wieke Eggink, Tove Henriksen, Eavan McGovern, Marenka Smit, Selma Aybek, Agnita Boon, Rick Brandsma, Andres Deik and 34 more

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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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5 · Who and what money

Authors and funding

44 authors.

Madelein van der StouweExpertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands.ORCID https://orcid.org/0000-0001-9497-2019
Olof VermeulenExpertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands.
Wieke EgginkExpertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands.ORCID https://orcid.org/0000-0002-7006-1672
Tove HenriksenMovement Disorder Clinic, University Hospital of Bispebjerg, Copenhagen, Denmark.
Eavan McGovernDepartment of Neurology, Beaumont Hospital, Dublin, Ireland.ORCID https://orcid.org/0000-0001-7325-8959
Marenka SmitDepartment of Neurology, Medical Clinic Velsen, Velsen-Noord, the Netherlands.
Selma AybekDepartment of Neurology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.ORCID https://orcid.org/0000-0002-7877-6760
Agnita BoonDepartment of Neurology, Erasmus MC Rotterdam, Rotterdam, the Netherlands.
Rick BrandsmaDepartment of Pediatric Neurology, University Medical Center Utrecht, Utrecht, the Netherlands.
Andres DeikParkinson's Disease and Movement Disorders Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA.ORCID https://orcid.org/0000-0001-5527-0196
Roberto ErroDepartment of Medicine, Surgery and Dentistry "Scuola Medica Salernitana," University of Salerno, Fisciano, Italy.ORCID https://orcid.org/0000-0002-7800-7419
Alberto EspayJames J. and Joan A. Gardner Family Center For Parkinson's Disease and Movement Disorders, University of Cincinnati, Cincinnati, Ohio, USA.ORCID https://orcid.org/0000-0002-3389-136X
Cristian Falup-PecurariuFaculty of Medicine, Transilvania University, Brasov, Romania.ORCID https://orcid.org/0000-0002-7394-7161
Stephen FruchtNYU Grossman School of Medicine, New York, New York, USA.
Christos GanosDivision of Neurology, Department of Medicine, Movement Disorders Clinic, Toronto Western Hospital, UHN, University of Toronto, Toronto, Ontario, Canada.
Emilia GattoDepartment of Clinical Medicine, Sanatorio de la Trinidad Mitre, Affiliated to the Faculty of Medicine of the University of Buenos Aires, Buenos Aires, Argentina.ORCID https://orcid.org/0000-0002-1346-5443
Rick HelmichCentre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, the Netherlands.ORCID https://orcid.org/0000-0003-4035-6573
Christine KleinInstitute of Neurogenetics, University of Lübeck, Lübeck, Germany.
Hans KoelmanDepartment of Neurology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands.
Vincent OdekerkenDepartment of Neurology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands.
Lisette KoensDepartment of Neurology and Clinical Neurophysiology, Martini Ziekenhuis, Groningen, the Netherlands.ORCID https://orcid.org/0000-0002-2864-4225
Abhimanyu MahajanJames J. and Joan A. Gardner Family Center For Parkinson's Disease and Movement Disorders, University of Cincinnati, Cincinnati, Ohio, USA.ORCID https://orcid.org/0000-0001-8807-6672
Francesca MorganteNeurosciences and Cell Biology Institute, Neuromodulation and Motor Control Section, City St George's University of London, London, UK.
Alexander MünchauInstitute of Systems Motor Science, CBBM, University of Lübeck, Lübeck, Germany.ORCID https://orcid.org/0000-0002-3219-2284
Pattamon PanyakaewChulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Division of Neurology, Department of Medicine, Faculty of Medicine, King Chulalongkorn Memorial Hospital and Chulalongkorn University, Thai Red Cross Society, Bangkok, Thailand.
Kathryn PeallLaboratories of Neuroscience Research, Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK.ORCID https://orcid.org/0000-0003-4749-4944
Bélen Pérez-DueñasInnovative Therapies in Pediatric Neurology Research Group, Vall d'Hebron Research Institute, Barcelona, Spain.
Emanuel RozeSorbonne University, INSERM, CNRS, Paris Brain Institute, AP-HP, Institute of Neurology, Paris, France.ORCID https://orcid.org/0000-0001-9727-3459
Anna SadnickaGatsby Computational Neuroscience Unit, University College London, London, UK.ORCID https://orcid.org/0000-0001-6132-2773
Susanne SchneiderINSPIRE-PNRM+, Neuroimaging Center (NIC), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.ORCID https://orcid.org/0000-0001-7283-1995
Petra SchwingenschuhDepartment of Neurology, Medical University of Graz, Graz, Austria.ORCID https://orcid.org/0000-0002-3294-6824
Tereza SerranovaDepartment of Neurology, 1st Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czech Republic.ORCID https://orcid.org/0000-0001-6525-3971
Matej SkorvanekDepartment of Neurology, P.J. Safarik University, Kosice, Slovak Republic.ORCID https://orcid.org/0000-0001-5497-8715
Maria StamelouParkinson's Disease and Movement Disorders Department, HYGEIA, Athens, Greece.ORCID https://orcid.org/0000-0003-1668-9925
Gertrúd TamasDepartment of Neurology, Semmelweis University, Budapest, Hungary.ORCID https://orcid.org/0000-0001-8054-3678
Michele TinazziBiomedicine and Movement Sciences, Neurology Unit, Department of Neurosciences, University of Verona, Verona, Italy.ORCID https://orcid.org/0000-0002-2370-7063
Anna ValadasDepartment of Neurosciences and Mental Health, Neurology Hospital Santa Maria, CHLUN, Lisbon, Portugal.
Wim VandenbergheDepartment of Neurology, University Hospitals Leuven, Leuven, Belgium.ORCID https://orcid.org/0000-0002-9758-5062
Jeroen de VriesExpertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands.ORCID https://orcid.org/0000-0002-7534-4161
Rodi ZuttDepartment of Neurology, HagaZiekenhuis, The Hague, the Netherlands.
Sterre van der VeenExpertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands.ORCID https://orcid.org/0000-0003-0698-2087
Rogier LuikenDepartment of Rehabilitation Medicine, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
Inge TuitertExpertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands.
Marina TijssenExpertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands.ORCID https://orcid.org/0000-0001-5783-571X

Funding

European Regional Development Fund 01492947ZonMw 91218013
6 · The paper itself

Abstract

backgroundReliable clinical phenotyping is crucial for diagnosis, treatment, and research in hyperkinetic movement disorders, yet its interrater reliability remains uncertain.

objectivesTo quantify interrater agreement in clinical phenotyping of hyperkinetic movement disorders among experts in a large, phenotypically diverse cohort.

methodsWithin the NEMO project, 161 patients with hyperkinetic movement disorders underwent standardized video assessments. Each patient was independently classified by three international movement disorders experts in a structured, stepwise procedure. Experts first assessed videos alone, then received clinical history and examination, and finally diagnostic test results. At each step, they assigned primary and secondary phenotypes and rated their diagnostic confidence. Interrater agreement was assessed using Fleiss' and Cohen's kappa.

resultsAcross all phenotypes, interrater agreement on the primary phenotype increased with added information (κ = 0.457 to κ = 0.607). Agreement with the NEMO reference classification similarly improved (κ = 0.478 to κ = 0.656). Among patients with a single dominant phenotype, agreement reached κ = 0.78. In 93% of cases, at least two out of three experts reached consensus. Agreement was substantially lower in patients with mixed or complex presentations, such as myoclonus-dystonia and functional movement disorders. Diagnostic certainty rose throughout, though secondary phenotype agreement remained poor. Experts rarely revised initial impressions, suggesting robust pattern recognition but also potential confirmation bias.

conclusionsMovement disorders specialists can reliably identify hyperkinetic phenotypes, even without in-person assessment. While complex, mixed and functional presentations remain diagnostically challenging, our findings reinforce the value of expert phenotyping in clinical care, training, and research, and provide a benchmark for future studies and computational approaches.

Indexed as

dystoniafunctional movement disordersinterrater agreementmyoclonustremor

Identifiers

PMID42831418
PMCPMC13636365

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