Essential Tremor Increases Risk of Dementia

Elderly persons with essential tremor (ET) are almost twice as likely to have dementia as those without ET, according to a new study from Elan Louis, MD, professor of neurology, and colleagues at Columbia University in New York. “There has been a sense that there are cognitive abnormalities in essential tremor, and patients frequently complain of memory problems, but the question is whether we are looking at something greater, namely dementia,” he said.

Mild cognitive deficits have been reported in ET patients before, but they were mainly in frontal executive function and memory and were not severe enough to qualify as dementia.

To explore the association of ET and dementia, the authors examined more than 2000 elderly persons in northern Manhattan. Each person received a neurological evaluation. Handwriting samples were used to assign an ET diagnosis. Of the 2286 patients evaluated, 125 had ET. Dementia was found in 25% of ET patients, versus only 9% of persons without ET. Most patients with dementia met criteria for Alzheimer disease. ET was not associated with subcategories of mild cognitive impairment.

“Our results show that people with ET are predisposed to becoming demented,” Dr Louis said. “If you have one degenerative disease, it appears you are more likely to develop another.”

Dr Louis suggested that physicians should discuss the possible development of cognitive problems when talking with patients who have ET. “Rather than attributing cognitive complaints in ET patients to old age, they need to be treated as a disease manifestation,” he said. “Assessment and possible treatment of dementia should routinely be incorporated into the treatment plan.”

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Reference

1. Thawani SJ, Schupf N, Louis ED. Association between essential tremor and dementia: population-based study in northern Manhattan [S03.003]. Scientific Session, Tuesday, April 28, 2009.