Coprevalence of tremor with spasmodic dysphonia

A case-control study


  • Financial support provided by The Dystonia Coalition, which is part of the NIH Rare Diseases Clinical Research Network. Funding support for this project has been provided by NS067501 from the NIH Office of Rare Diseases Research and the National Institute of Neurological Disorders and Stroke. The views expressed in written materials or publications do not necessarily reflect the official policies of the Department of Health and Human Services; nor does mention by trade names, commercial practices, or organizations imply endorsement by the US Government. This project is also supported in part by PHS Grant Jul1RR125008, KL2 RR025009, and TL1 RR025010 from the Clinical and Translational Science Award program, National Institutes of Health, National Center for Research Resources. The authors have no other funding, financial relationships, or conflicts of interest to disclose.



The aim of this study was to define the coprevalence of tremor with spasmodic dysphonia (SD).

Study Design:

A single-institution, prospective, case-control study was performed from May 2010 to July 2010.


Consecutive patients with SD (cases) and other voice disorders (controls) were enrolled prospectively. Each participant underwent a voice evaluation and an evaluation for tremor.


There were 146 voice disorder controls and 128 patients with SD enrolled. Of patients with SD 26% had vocal tremor, 21% had nonvocal tremor. Patients with SD were 2.8 times more likely to have coprevalent tremor than the control group (odds ratio = 2.81; 95% confidence interval, 1.55-5.08), and only 35% of patients with SD had been seen by a neurologist for the evaluation of dystonia and tremor.


Tremor is highly prevalent in patients with SD. It is important for each patient diagnosed with SD to undergo an evaluation for tremor, and this is especially important in patients diagnosed with vocal tremor.