Relatives of Parkinson's disease victims more prone to dementia

According to a new study the relatives of people with Parkinson's disease are at an increased risk of developing dementia.

The study by researchers at the Mayo clinic College of Medicine in Rochester, Minnesota has found that family relatives of Parkinson's disease patients may be at an increased risk of developing dementia.

For the study the researchers studied 1,019 first-degree relatives of 162 Parkinson's disease patients and 858 relatives of 147 similar subjects without the disease.

The researchers measured the participants levels of thinking ability either by telephone interviews or in the case of those with dementia, by interviewing close associates; the medical records of demented subjects were reviewed to confirm the diagnosis.

The researchers, led by Dr. Walter A. Rocca found that relatives of Parkinson's disease patients were 37 percent more likely to show thinking deficits or dementia than were relatives of unaffected study participants.

The research also revealed that the risk increased if the Parkinson's patient developed their condition before reaching 66 years of age; relatives of patients with Parkinson's at a younger age were 73 percent more likely to have thinking impairments or dementia than were relative of unaffected subjects.

The researchers say the study shows relatives of patients with Parkinson's disease appear to be at increased risk for impaired thinking and dementia, suggesting the presence of shared susceptibility factors.

The study is the first large population-based study to indicate that a relative is susceptible to developing one or both disorders if an immediate family member has either disease; it will hopefully encourage researchers to investigate those risk factors.

The study is published in current edition of the Archives of Neurology, October 2007.