Table of Contents
Journal of Neurodegenerative Diseases
Volume 2014, Article ID 328765, 5 pages
http://dx.doi.org/10.1155/2014/328765
Research Article

Essential Tremor in the Elderly and Risk for Dementia

1Banner Sun Health Research Institute, 10515 West Santa Fe. Drive, Sun City, AZ 85351, USA
2Mayo Clinic Arizona, 13400 East Shea Boulevard, Scottsdale, AZ 85259, USA

Received 29 January 2014; Revised 21 March 2014; Accepted 23 March 2014; Published 9 April 2014

Academic Editor: Gammon M. Earhart

Copyright © 2014 Holly A. Shill et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The objective is to examine the risk of dementia in subjects with essential tremor (ET) involved in the Arizona Study of Aging and Neurodegenerative Disorders. All subjects were free of a neurodegenerative diagnosis at baseline and had annual motor, general neurological, and neuropsychological assessments. Subjects with ET were compared with controls for the risk of dementia. There were 83 subjects with ET and 424 subjects without tremor. Mean age at study entry was for ET and for controls. Median tremor duration was 5.2 years at study entry. Followup was a median of 5.4 years (range 0.9 to 12.1). The hazard ratio for the association between ET and dementia was 0.79 (95% CI 0.33 to 1.85). The hazard ratio for the association between tremor onset at age 65 or over, versus onset before age 65, was 2.1 (95% CI 0.24 to 18) and the hazard ratio for the association between tremor duration greater than 5 years, versus less than 5 years, was 0.46 (95% CI 0.08 to 2.6). We conclude that all elderly ET was not associated with an increased risk of dementia but that a subset of subjects with older age onset/shorter duration tremor may be at higher risk.