Head tremor at disease onset: an ataxic phenotype of cervical dystonia

• Type of Material: Article
• Authors: Aristide Merola, University of Cincinnati; Alok K. Dwivedi, Texas Tech University; Aasef G. Shaikh, Case Western Reserve University; Tamour Khan Tareen, University of Cincinnati; Gustavo A. Da Prat, University of Cincinnati; Marcelo A. Kauffman, UBA; Jennif Hampf, University of Lubeck; Abhimanyu Mahajan, University of Cincinnati; Luca Marsili, University of Cincinnati; Joseph Jankovic, Baylor College of Medicine; Cynthia L. Comella, Rush University; Brian D. Berman, University of Colorado; Joel S. Perlmutter, Washington University; Hyder Jinnah, Emory University; Alberto J. Espay, University of Cincinnati
• Language: English
• Date: 2019-08-01
• Publisher: Springer Heidelberg
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © Springer-Verlag GmbH Germany, part of Springer Nature 2019.
• Final Published Version (URL): http://dx.doi.org/10.1007/s00415-019-09341-w
• Title of Journal or Parent Work: Journal of Neurology
• Volume: 266
• Issue: 8
• Start Page: 1844
• End Page: 1851
• Grant/Funding Information: This study was supported in part by a grant to the Dystonia Coalition (U54 TR001456 and NS065701) from the Office of Rare Diseases Research (ORDR) in the National Center for Advancing Translational Sciences (NCATS) and the National Institute of Neurological Disorders and Stroke (NINDS).
• Keywords: Neurosciences & Neurology; Scale; Life Sciences & Biomedicine; Cerebellar; Consensus; Dystonia; Secondary; Tremor; Head tremor; Clinical Neurology; Science & Technology; Cerebellum; Ataxia
• Research Categories: Psychology, Clinical; Biology, Neuroscience; Biology, Biostatistics; Health Sciences, Epidemiology

Abstract

Background Cervical dystonia (CD) can present with head tremor. It is unclear whether ataxic features are differentially associated with this phenotype at onset of CD. Objectives We sought to evaluate: (1) the demographic features of CD patients with (Tr-CD) and without head tremor (nTr-CD) at onset, and (2) the differential ataxic features between these CD subtypes. Methods For the first objective, we compared demographic data in Tr-CD versus nTr-CD subtypes in the entire cohort of CD subjects enrolled in the Dystonia Coalition Natural History and Biorepository studies (n=1608). For the second objective, we rated the standardized videos from consecutively enrolled Tr-CD subjects (n=50) and age-, gender-, and disease duration-matched nTr-CD subjects (n=50) for ataxia severity scoring using the Scale for the Assessment and Rating of Ataxia (SARA) and the International Cooperative Ataxia Rating Scale (ICARS); and for dystonia severity using the Toronto Western Spasmodic Torticollis Rating Scale section-I (TWSTRS) and the Global Dystonia Rating Scale (GDRS). Results Of 1,608 subjects, 18.1% (n=291) were classified as Tr-CD and 81.9% (n=1317) as nTr-CD. The Tr-CD cohort was older, predominantly female, and had longer disease duration than the nTr-CD cohort (p= 0.01). Compared to nTr-CD, Tr-CD subjects had worse generalized ataxia, speech, and gait and posture scores. High ataxia severity with low dystonia severity distinguished Tr-CD from nTr-CD with high accuracy (area under the curve, 0.91 (95%CI: 0.85–0.97). Conclusions Head tremor at disease onset represents a clinically distinguishable subtype of cervical dystonia affecting predominantly older women, with worse ataxia and milder dystonia than the non-tremulous dystonic phenotype.