New Montreal Scale Is Reliable Predictor of Parkinson’s Dementia, Study Finds

Montreal researchers have developed a scale that doctors can use in their office to predict Parkinson’s patients’ risk of developing dementia.

Not only is it accurate, but it’s also cheaper, easier to use and more practical than other methods, the team said.

The research, “Office-Based Screening for Dementia in Parkinson Disease:The Montreal Parkinson Risk of Dementia Scale in 4 Longitudinal Cohorts,” appeared in the journal JAMA Neurology.

Scientists have developed treatments for the movement symptoms in Parkinson’s, but there are few therapies for non-movement complications such as dementia.

Dementia is six times more prevalent in Parkinson’s patients than in the general population, and has a significant impact on patients’ and caregivers’ quality of life. Its prevalence increases with patients’ age and the severity of their Parkinson’s

In addition to age, other predictors of Parkinson’s dementia include early cognitive problems, mutations of the GBA gene, rapid eye movement sleep behavior disorder (RBD), and a certain ratio of amyloid beta protein to tau protein in cerebrospinal fluid. These findings have not been translated into patient care, however.

Montreal researchers came up with an inexpensive predictor called the  Montreal Parkinson Risk of Dementia Scale. It includes eight items, including an age younger than 70 years, being a male, falling or step-freezing while walking, having another disease besides Parkinson’s, a history suggesting RBD, a drop in blood pressure while standing, mild cognitive impairment, and visual hallucinations.

The researchers tested the scale in four Parkinson’s groups between May 2005 and June 2016. The study included 607 patients who had not exhibited signs of dementia. Their mean age was 63.4 years, and 376 were men.

After a year or more, 70 patients, or 11.5%, had developed dementia. Researchers found that all eight items in the scale significantly predicted their dementia.

Those in a group that the scale classified as high risk developed dementia more than intermediate or low-risk groups. A score of 5 or more was considered high risk.

A score of 4 or higher could predict dementia risk within four years with high accuracy, the team said.

Another finding was a good correlation between patients’ scores and several biological and neuropsychological predictors of cognitive decline.

The Montreal scale “compares well with other dementia predictors that use more complex or invasive testing techniques,” the researchers wrote.

Researchers said the scale was practical for doctor’s-office use because it does not require collecting biological samples, taking brain scans, or doing genetic testing. It could be also used for clinical trials, they said.

Doctors can come up with a dementia prediction score ‘during a single outpatient office visit, and the results are available without delay or requirement for statistical software,” the researchers wrote. “In addition to allowing prompt clinical counselling and life planning, this can have practical treatment implications.”