April 03, 2018
By Lorraine L. Janeczko
NEW YORK (Reuters Health) - The Montreal Parkinson Risk of Dementia Scale (MoPaRDS), an eight-item office-based screening tool, can help screen patients with Parkinson disease for dementia, new research shows.
"Currently, predicting Parkinson disease (PD) dementia risk is difficult, particularly in an office-based setting, without extensive biomarker testing,” write Dr. Ronald B. Postuma of McGill University in Montreal, Canada, and colleagues in JAMA Neurology, online March 26.
“With simple measures that are assessable in a single office visit,” they add, their new “risk score rapidly and accurately screens for dementia risk in PD."
The MoPaRDS tool is based on eight items that can be collected at an office visit, Dr. Postuma explained in an email to Reuters Health: 1) age over 70, 2) male, 3) blood pressure drop with standing, 4) early mild cognitive changes, 5) symmetric bilateral disease, 6) falling or freezing, 7) hallucinations and 8) symptoms of rapid eye movement (REM) sleep behavior disorder.
Dr. Postuma and his colleagues tested their tool in a multicenter study including four diverse cohorts of patients with Parkinson disease. Overall, 717 patients were recruited between 2005 and 2016, with a prospective follow-up period of 4.4 years.
Among these patients, the 607 who were dementia-free at baseline and who were followed for one year or longer were included in the study. Of the 376 men and 231 women, 70 (11.5%) developed dementia.
All eight items of the MoPaRDS independently predicted future dementia. The annual conversion rate to dementia in the high-risk group (score over 5) was 14.9% compared to 5.8% in the intermediate group (score 4 to 5) and 0.6% in the low-risk group (score 0 to 3).
“Having a positive MoPaRDS screen (at least 4 of the 8 items) was linked to a 14-fold increase in risk of dementia, compared to participants with a negative screen," Dr. Postuma said.
With a cutoff of 4 or greater, the tool’s sensitivity was 77.1% and its specificity 87.2%, for a positive predictive value of 43.90% and a negative predictive value of 96.70%.
"Identifying patients who are at especially high risk for dementia has important potential clinical counseling and treatment implications,” Dr. Postuma noted. “For example, knowing that a person is likely to get dementia in the near future would probably steer you away from certain medications and towards others. Most critically, this knowledge can help select patients for trials to prevent dementia."
The researcher said he would like to add more variables to the screening tool.
"This dementia prediction tool is a starting point, and other variables exist that can be used to predict dementia. If we continue to expand the list of variables, we can get better and better estimates," he said. "Also, now that a simple tool can identify dementia, we have to try and do something about it. Several treatments that have the potential to prevent Parkinson disease dementia are in early-phase testing."
The study had no commercial funding.
JAMA Neurol 2018.
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