DIFFERENCES IN THE PREVALENCE OF ESSENTIAL TREMOR AMONG ELDERLY AFRICAN-AMERICANS, WHITES, AND HISPANICS IN NORTHERN MANHATTAN, NY

Background: Until now there has been only one community-based study to examine interethnic differences in the prevalence of essential tremor (ET). The study suggested a higher prevalence among whites than African Americans. The present study is the first to examine differences in the prevalence of ET among Hispanics, African Americans, and whites. Objective: To estimate the prevalence of essential tremor (ET) in a cohort of community-dwelling elderly of mixed ethnic background. Methods: A random sample of 2117 Medicare recipients residing in Washington Heights-Inwood in northern Manhattan, NY, were interviewed. A standardized neurological assessment was performed on those who had neurological complaints and on a random sample of those who did not. Essential tremor was defined as a postural or kinetic tremor of the head or limbs. Diagnoses were independently confirmed by two neurologists based on videotaped examination. Results: After age adjustment to the 1990 Washington Heights-Inwood census, the prevalence of ET was 40.2 per 1000 (95% confidence interval, 31.8 to 48.6). Among 46 cases with ET, ET was significantly more prevalent in men than in women (chi(2) = 5.0, P = .03). Prevalence increased significantly with age. The prevalence was higher in whites than African Americans. The prevalence in Hispanics was intermediate. Conclusion: The prevalence of ET increases with age and may be higher among men and whites. Prospective studies are needed to further examine these associations.