Interrater and Intrarater Reliability of the TWSTRS ‐Delphi Motor Severity Scale for Cervical Dystonia
Year: 2026
Type: article
Abstract: BACKGROUND: Cervical dystonia (CD) motor severity is typically quantified with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). An expanded version of the Motor Severity section of the TWSTRS ("TWSTRS-Delphi") has been previously evaluated for its clinimetric properties but not for inter- and intrarater reliability. OBJECTIVE: In this study we quantified inter- and intrarater reliability of the Motor Severity section of the TWSTRS-Delphi for CD. METHODS: Ten raters familiar with the TWSTRS-Delphi and ten raters unfamiliar with it independently scored standardized videos from 90 patients with CD. We computed one-way random intraclass correlation coefficient (ICC, absolute agreement) for total and item scores. We repeated assessments and calculations with a subset of raters to assess intrarater reliability. RESULTS: Interrater reliability for the Total score was good for Familiar raters (ICC = 0.697) and fair for Unfamiliar raters (ICC = 0.566). Most individual items achieved fair-excellent interrater agreement in both groups (Familiar 0.415-0.763; Unfamiliar 0.416-0.769). Sagittal Shift, Duration, and Sensory Tricks showed poor agreement. Intrarater reliability was fair-excellent for most items in both groups (Familiar 0.494-0.927; Unfamiliar 0.413-0.877), but poor for Sagittal Shift and Duration among Familiar raters. CONCLUSIONS: The TWSTRS-Delphi yields reproducible Total and item scores across movement disorder raters. The data pinpoint Sagittal Shift, Duration, and Sensory Tricks as the principal sources of between-rater variability, defining immediate priorities for scale modification and focused training.
DOI: 10.1002/mdc3.70757
Authors: Glenn T. Stebbins, Charles H. Adler, Alberto Albanese, Richard L. Barbano, Anna Rita Bentivoglio, Carlo Colosimo, Maria Fiorella Contarino, Dirk Dressler, Stewart A. Factor, Susan H. Fox, Victor S.C. Fung, Christopher G. Goetz, Joseph Jankovic, Hyder A. Jinnah, Wolfgang H. Jost, Marina A.J. Tijssen, Elena Moro, Joel S. Perlmutter, Stephen G. Reich, Ramon L. Rodriguez, Lawrence Severt, Natividad P. Stover, Marie Vidailhet, Julianne Lee, Cynthia L. Comella, David A. Peterson
Institutions: Rush University Medical Center, Mayo Clinic, Mayo Clinic in Arizona, Fondazione Istituto Neurologico Nazionale Casimiro Mondino, University of Rochester Medicine, Università Cattolica del Sacro Cuore, Agostino Gemelli University Polyclinic, Ospedale Generale Regionale Francesco Miulli, Leiden University Medical Center, Haga Hospital, Medizinische Hochschule Hannover, Emory University, University Health Network, University of Toronto, Toronto Western Hospital, The University of Sydney, Baylor College of Medicine, Parkinson-Klinik Ortenau, University Medical Center Groningen, Grenoble Institute of Neurosciences, Université Grenoble Alpes, Washington University in St. Louis, University of Maryland, Baltimore, AbbVie (United States), University of Alabama at Birmingham, Centre National de la Recherche Scientifique, Inserm, Sorbonne Université, Assistance Publique – Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Institut du Cerveau, University of California San Diego, Salk Institute for Biological Studies
Language: English
Subfield: Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7204499911