Risk of incident dementia in essential tremor: a population-based study

Mov Disord. 2007 Aug 15;22(11):1573-80. doi: 10.1002/mds.21553.


Essential tremor (ET) is a late-life neurological disease. Mild cognitive deficits as well as an association with prevalent dementia have been reported in recent case-control studies. We determined whether ET was associated with an increased risk of incident dementia. In a population-based study of older people in central Spain (NEDICES), nondemented ET cases and controls were followed prospectively. Incident dementia at follow-up was diagnosed using DSM-IV criteria and the risk of incident dementia was estimated in ET cases versus controls using Cox proportional hazards models. 3,891 participants had a mean duration of follow-up of 3.2 years. Sixteen (7.8%) of 206 ET cases developed incident dementia versus 145 (3.9%) of 3,685 controls (unadjusted relative risk [RR]=2.08, 95% CI=1.24-3.50, P=0.006 and adjusted RR=1.66, 95% CI=0.99-2.80, P=0.054). In an adjusted model, ET cases with tremor onset after age 65 years were twice as likely to develop incident dementia than were controls (RR=1.98, 95% CI=1.14-3.45, P=0.01), whereas ET cases with tremor onset<age 65 years and controls were equally to develop incident dementia (RR=0.74, 95% CI=0.19-3.20, P=0.79). Although ET is often considered a benign condition, in this prospective, population-based study, elderly-onset ET was associated with an increased risk of incident dementia. The basis for this dementia, which is not known, requires additional study.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Community Health Planning*
  • Dementia / epidemiology*
  • Dementia / etiology*
  • Essential Tremor / complications*
  • Essential Tremor / epidemiology*
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Male
  • Proportional Hazards Models
  • Prospective Studies
  • Psychiatric Status Rating Scales
  • Risk*
  • Spain / epidemiology