People with essential tremor, a movement disorder that causes shaking of the hands, head, voice, or body, are more likely to develop dementia, according to research that will be presented at the American Academy of Neurology 57th Annual Meeting in Miami Beach, Fla., April 9 – 16, 2005.
People with essential tremor were more than two times more likely to develop dementia than people who did not have the movement disorder.
"This is the first study to suggest that essential tremor is associated with the development of dementia," said study author Julián Benito-Leon, MD, PhD, of Mostoles General Hospital in Madrid, Spain. "We don't yet know whether the dementia is due to the same underlying problem that is causing the essential tremor or whether it is caused by another problem."
The study involved a door-to-door survey of elderly people in central Spain. The study followed 202 people with essential tremor and 3,541 people with no dementia or movement disorders for an average of three years. Over that time, 15 of the people with essential tremor developed dementia, or 7.4 percent, compared to 126 people in the control group, or 3.5 percent.
Essential tremor is a common condition, affecting up to 1 in 5 people over age 65.