Family link with dementia and Parkinson's

ROCHESTER, Minn., Oct. 9 (UPI) -- The relatives of patients with Parkinson's disease risk developing dementia or cognitive impairment, U.S. researchers found.

The findings, published in the Archives of Neurology, suggest the action of shared familial susceptibility factors -- genetic or non-genetic -- in Parkinson's disease.

Dr. Walter Rocca, of the Mayo Clinic College of Medicine, in Rochester, Minn., studied 1,019 first-degree relatives of 162 patients with Parkinson’s disease, 858 relatives of 147 people who were the same age and sex as someone in the Parkinson’s disease group, but did not have the condition and other relatives of patients with Parkinson’s disease.

"This study provides evidence that relatives of patients with Parkinson’s disease have an increased risk of cognitive impairment or dementia," Rocca said in a statement. "This association is primarily driven by families of patients with younger age at onset of Parkinson’s disease, but the risk does not vary across relatives of patients with different clinical characteristics of Parkinson’s disease."

Relatives of patients who experienced the onset of Parkinson's disease at age 66 or younger had a particularly increased risk of developing dementia or cognitive impairment, Rocca said.