Jaw tremor: Prevalence and clinical correlates in three essential tremor case samples

Authors

  • Elan D. Louis MS, MD,

    Corresponding author
    1. Gertrude H. Sergievsky Center, Columbia University, New York, New York, USA
    2. Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York, USA
    3. Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
    • Unit 198, Neurological Institute, 710 West 168th Street, New York, NY 10032
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  • Eileen Rios BS,

    1. Gertrude H. Sergievsky Center, Columbia University, New York, New York, USA
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  • LaKeisha M. Applegate BA,

    1. Gertrude H. Sergievsky Center, Columbia University, New York, New York, USA
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  • Nora C. Hernandez MD,

    1. Gertrude H. Sergievsky Center, Columbia University, New York, New York, USA
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  • Howard F. Andrews PhD

    1. Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, New York, USA
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Abstract

The spectrum of involuntary movements seen in essential tremor (ET) is limited. Jaw tremor is one such movement. The prevalence and clinical correlates of jaw tremor have not been studied in detail. The objective of this study was to estimate the prevalence and examine the clinical correlates of jaw tremor in ET using ET cases from three distinct settings (population, tertiary-referral center, brain repository). All ET cases underwent a videotaped tremor examination in which tremors (including limb, head, voice, and jaw) were assessed. The prevalence [95% confidence interval (CI)] of jaw tremor was lowest in the population sample (7.5%; 3.9%–14.2%), intermediate in the tertiary-referral center (10.1%; 6.8%–14.7%), and highest in the brain repository (18.0%; 12.3%–25.5%; P = 0.03). Jaw tremor was associated with older age (P < 0.001), more severe action tremor of the arms (P < 0.001), and presence of head and voice tremor (P < 0.001). Jaw tremor was present in 4/14 (28.6%) ET cases with consistent rest tremor vs. 15/193 (7.8%) cases without rest tremor (odds ratio = 4.8; 95% CI = 1.3–7.0; P = 0.009). The prevalence of jaw tremor was 7.5% to 18.0% and was dependent on the mode of ascertainment, being least prevalent in a population-based sample. ET cases with jaw tremor had a more clinically severe and more topographically widespread disorder. The association in our study between jaw tremor and rest tremor, along with the published observation that jaw tremor can occur in Parkinson's disease (PD), raises the question whether jaw tremor in ET is a marker for subsequent conversion to PD. © 2006 Movement Disorder Society

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