Elan D Louis1,2,3, James H Meyers1, Olufunmilayo M Badejo1, Ashley D Cristal1, Ruby Hickman1, Pam Factor-Litvak4. 1. Department of Neurology, Yale School of Medicine, Yale University, New Haven, Connecticut, USA. 2. Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, Connecticut, USA. 3. Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, Connecticut, USA. 4. Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York, USA.
Abstract
BACKGROUND: The burden of mild (i.e., subclinical) tremor within essential tremor (ET) families is not fully understood. We assessed the burden of mild tremor in a cohort of 287 adults, none of whom reported tremor or were diagnosed with ET. METHODS: We recruited adults in 2 groups based on the familial risk for ET: 244 high-risk individuals (i.e., reporting one or more first-degree relative with ET) and 43 low-risk individuals (i.e., reporting no relatives with ET). Tremor was objectively assessed on 4 hand-drawn spirals (total spiral score = 0-12). Mild tremor was defined using 3 different cut points. RESULTS: The prevalence rates of mild tremor among high-risk individuals ranged from 41.4 to 98.4% and were highly dependent on the cut point. Above a certain threshold (i.e., a total spiral score ≥5), 1-in-5 (i.e., 19.7%) high-risk individuals exhibited mild tremor, whereas no low-risk individuals did. High-risk individuals were 3.09-4.50 times more likely than low-risk individuals to exhibit mild tremor. CONCLUSION: The burden of ET extends beyond the boundaries of the clinically defined disease, and partially expressed forms of ET are abundant in ET families. This fact greatly complicates gene-finding studies and epidemiological studies whose goal is to detect disease-linked associations.
BACKGROUND: The burden of mild (i.e., subclinical) tremor within essential tremor (ET) families is not fully understood. We assessed the burden of mild tremor in a cohort of 287 adults, none of whom reported tremor or were diagnosed with ET. METHODS: We recruited adults in 2 groups based on the familial risk for ET: 244 high-risk individuals (i.e., reporting one or more first-degree relative with ET) and 43 low-risk individuals (i.e., reporting no relatives with ET). Tremor was objectively assessed on 4 hand-drawn spirals (total spiral score = 0-12). Mild tremor was defined using 3 different cut points. RESULTS: The prevalence rates of mild tremor among high-risk individuals ranged from 41.4 to 98.4% and were highly dependent on the cut point. Above a certain threshold (i.e., a total spiral score ≥5), 1-in-5 (i.e., 19.7%) high-risk individuals exhibited mild tremor, whereas no low-risk individuals did. High-risk individuals were 3.09-4.50 times more likely than low-risk individuals to exhibit mild tremor. CONCLUSION: The burden of ET extends beyond the boundaries of the clinically defined disease, and partially expressed forms of ET are abundant in ET families. This fact greatly complicates gene-finding studies and epidemiological studies whose goal is to detect disease-linked associations.
Authors: Manuel Seijo-Martínez; María Castro Del Río; Jose Ramon Rodríguez Alvarez; Ramon Suarez Prado; Eugenio Torres Salgado; Javier Paz Esquete; Maria Jesus Sobrido-Gómez Journal: Tremor Other Hyperkinet Mov (N Y) Date: 2013-09-03
Authors: Elan D Louis; Funmi M Badejo; Ashley D Cristal; James Meyers; Nora Hernandez; Karen P Chen; Kelly V Naranjo; Jemin Park; Lorraine N Clark Journal: Tremor Other Hyperkinet Mov (N Y) Date: 2017-03-25
Authors: James H Meyers; Ruby Hickman; Ashley D Cristal; Pam Factor-Litvak; Stephanie Cosentino; Elan D Louis Journal: Parkinsonism Relat Disord Date: 2018-10-31 Impact factor: 4.891