Essential Tremor Tied to Greater Risk of Dementia

People with essential tremor are nearly three times as likely to develop dementia compared to the general population, new research shows.
In the new study, nearly 20% of older adults with essential tremor had dementia. However, the rates were lower than those seen in adults with Parkinson’s disease.
The study is “the most complete exposition of the longitudinal trajectory of cognitive impairment in an ET cohort,” say the authors, led by Elan D. Louis, MD, MSc, from University of Texas Southwestern Medical Center in Dallas.
For the study, 222 adults (average age at the beginning of the study was 79) with essential tremor underwent detailed cognitive tests and were followed for an average of 5 years.
At the beginning of the study, 168 people had normal cognitive skills, 35 had mild cognitive impairment and 19 had dementia. During follow up, 59 individuals developed cognitive issues and 41 dveloped dementia.
During follow up, the total rate of dementia was 18.5% and 12.2% of participants moved from mild cognitive impairment to dementia. The overall rate of dementia among patients with tremor is roughly 300% greater than that among people in the general population, and 50% greater than that reported for adults with Parkinson’s disease.
The total rate of mild cognitive impairment – 26.6% -was nearly double that of the general population, but less than that in Parkinson’s patients.
“Our data indicate that the prevalence of and conversion rates to dementia in ET fall between those associated with the natural course of aging and the more pronounced rates observed in individuals with PD,” the researchers wrote.
Reached for comment, Shaheen Lakhan, MD, neurologist and researcher based in Miami, said, “The days of viewing [essential tremor] as just a ‘nuisance tremor’ are over. This study shatters the notion that essential tremor is a trivial condition.”
“Moving forward, the research agenda must further elucidate the link between ET and dementia and develop neuroprotective strategies. But this study represents a seismic shift in how we understand essential tremor,” Lakhan said.
“The benign label no longer applies given the cognitive risks ET patients face. Our clinical practice and communication with patients must adapt accordingly,” he added.