In Parkinson's, tremors may be a good sign

April 20, 2016

Specialists have long suspected that symptoms progressed more slowly in Parkinson's disease patients whose main problem was tremors, rather than walking or balance. Researchers at the University of Pennsylvania have found a connection among a genetic variation, tremors, and slower progression of the disease.

Specialists have long suspected that symptoms progressed more slowly in Parkinson's disease patients whose main problem was tremors, rather than walking or balance.

Researchers at the University of Pennsylvania have found a connection among a genetic variation, tremors, and slower progression of the disease.

The information does not yet explain why some patients have a better course, but it may lead to more precise, individually targeted treatments and more accurate information for patients.

"The immediate practical importance is in clinical trial design," said Alice Chen-Plotkin, an assistant professor of neurology at Penn and the new study's senior author.

Scientists can better assess a treatment's effectiveness when they know how a disease is likely to unfold. A new drug, for example, could look less effective than it actually is if a clinical trial has an unusually high proportion of people with the newly studied genetic variation.

Chen-Plotkin and lead author Christine Cooper, a fellow in movement disorders at Penn, are presenting their work this week at the annual meeting of the American Academy of Neurology in Vancouver, British Columbia.

They looked at genetic variations in 251 Parkinson's disease patients at Penn. Thirty-nine of them had a variation associated with tremors rather than balance problems, as well as slower disease progression and lower levels of alpha sinuclein - the protein that is the primary component of Lewy bodies - in the brain.

The relationship held up when the Penn team analyzed 559 patients from the University of Cincinnati, the University of Washington, and Oregon Health and Science University.

The researchers measured progression on a 27-question exam that doctors use to evaluate physical function. Each question can be answered on a zero-to-4 scale. Higher scores reflect more impairment. In the study, patients with the genotype increased from an average score of about 23 at their first visit to 35 six years later. Patients with other genotypes increased from 23 to 41 during that time period.

Cooper said that doctors still do not know why people get Parkinson's and why about a third of them never have tremors. She said patients vary widely in their symptoms and in response to medication.

sburling@phillynews.com

215-854-4944 @StaceyABurling

http://www.philly.com/philly/news/20160420_In_Parkinson_s__tremors_may_be_a_good_sign.html