Clinical Outcome Assessments in Movement Disorders: A Scoping Review of Current Rating Scales and Future Needs Beyond Parkinson's Disease

Abstract Background Clinical outcome assessments (COA) are essential for evaluating symptom severity, treatment response, and disease progression in movement disorders. As clinical knowledge evolves, it is necessary to ensure COAs continued relevance and validity. Objectives The aims were to provide an updated overview of existing Movement Disorder Society (MDS)–recommended COAs in movement disorders and to identify specific constructs or COAs requiring further revision or validation to inform current clinical practice and research. Methods The Scientific Evaluation Committee of the MDS‐COA program commissioned a position paper on the current evidentiary state of COAs. A panel of experts conducted a 2‐step review: first, extracting data from previous MDS publications on COA appraisals using a standardized template; second, conducting a scoping review up to May 2026 to identify new COAs or updated validation data in movement disorders. All study designs were considered. Results Of the 13 constructs identified in movement disorders other than PD, updated reviews are most urgently warranted for tremor and dystonia, given the volume of new evidence, emergence of novel instruments, and expanding therapeutic options. For all remaining constructs, important advances were identified alongside persistent gaps in validation, longitudinal data, and clinical interpretability. Conclusions The principal challenge in movement‐disorder outcome assessment has shifted from developing new instruments to establishing their comparative validity, responsiveness, and clinical interpretability. Tremor and dystonia have accumulated sufficient new evidence to justify updated MDS reviews, whereas across all constructs the major unmet needs are harmonization of existing measures, longitudinal validation, and integration of patient‐reported and digital outcomes into clinically meaningful assessment frameworks.