AUTHOR=Beylergil Sinem Balta , Mukunda Krishna Nikhil , Elkasaby Mohamed , Perlmutter Joel S. , Factor Stewart , Bäumer Tobias , Feurestein Jeanne , Shelton Erika , Bellows Steven , Jankovic Joseph , Mahajan Abhimanyu , Wamer-Rosen Tila , Reich Stephen G. , Wagle Shukla Aparna , Malaty Irene , Espay Alberto , Duque Kevin , LeDoux Mark S. , Saunders-Pullman Rachel , Leaver Katherine , Frank Samuel , Pantelyat Alexander , Fung Victor , Pirio Richardson Sarah , Berman Brian , Stover Natividad , Deik Andres , Ondo William , Groth Christopher , Jinnah Hyder A. , Shaikh Aasef G. 

TITLE=Tremor in cervical dystonia

JOURNAL=Dystonia

VOLUME=Volume 3 - 2024

YEAR=2024

URL=https://www.frontierspartnerships.org/journals/dystonia/articles/10.3389/dyst.2024.11309

DOI=10.3389/dyst.2024.11309

ISSN=2813-2106

ABSTRACT=Background: Cervical dystonia (CD) is the most common form of focal dystonia encountered in the clinic. Approximately one third of CD patients have co-existing tremor in the neck and hands. Assessment of tremor as regular or irregular in context of its oscillation trajectory, frequency, and amplitude is a major clinical challenge and can confound the diagnosis of CD and its subtypes. 
Methods: We analyzed the largest cohort of CD patients (n=3117) available to date, collected from 37 movement disorder centers in North America, Europe, and Asia. We statistically determined which features in clinical assessments predicts the presence of tremor as well as its regular or irregular appearance. 
Results: Out of 3117 CD patients, 1367 (44%) had neck tremor. The neck tremor was interpreted as irregular in 1022, regular in 345, and mixed (both irregular and regular) in 442. A feature importance analysis determined that greater severity of CD, longer disease duration, and older age, in descending order, predicted the presence of neck tremor. The probability of neck tremor was reduced if the dystonia affected other body parts in addition to the neck. We also found a significantly heightened risk for developing neck tremor in women. An additional feature importance analysis indicated that increased severity of dystonia affecting other body parts, severity of CD, and prolonged disease duration was associated with a lower likelihood of regular neck tremor while increased age predicted a higher likelihood. 
Conclusion: Our analysis recognized the most relevant clinical features that can predict concurrent neck tremor and its irregularity in a large multi-center dystonia cohort. These results call for a more accurate description of neck tremor in dystonia, which will then lead to improved care path.