Predictive Tool May Be Effective for Identifying Dementia Risk in Parkinson Disease
The Montreal Parkinson Risk of Dementia Scale is an 8-item, office-based screening tool.
The Montreal Parkinson Risk of Dementia Scale (MoPaRDS), which comprises 8 simple clinical variables, is effective for predicting the risk for dementia in patients with Parkinson disease (PD), according to findings from a multicenter study published in JAMA Neurology.
Investigators recruited 717 patients with Parkinson disease, of whom 607 were free from dementia at baseline. Participants were derived from 4 cohorts consisting of patients from Japan, Canada, and other sites from the Parkinson Progression Markers Initiative.
Findings from a literature review and a 4.4-year prospective cohort study were used to develop the MoPaRDS, which comprises 8 items: age <70 years, male sex, falls and/or freezing, onset of bilateral disease, history of rapid eye movement disorder, orthostatic hypotension, mild cognitive impairment (MCI), and visual hallucinations. Using the MoPaRDS as a scoring system, the investigators stratified participants into 3 groups based on risk: high (6-8), intermediate (4-5), or low (0-3). The investigators assessed the associations between baseline scale items with dementia risk to determine the predictive validity of the MoPaRDS.
Among the patients who were free from dementia, 70 (11.5%) converted to dementia during a mean follow-up of 4.4 years. Annual conversion rates to dementia in the high-, intermediate-, and low-risk groups were 14.9%, 5.8%, and 0.6%, respectively. Patients with dementia who scored in the high- (hazard ratio [HR] 20.8; 95% CI, 10.4-41.6) and intermediate-risk (HR 10.6; 95% CI, 5.1-19.8) groups on the MoPaRDS had a significantly faster progression to dementia compared with those who scored in the low-risk group (P <.001).
Across all cohorts, the overall predictive validity (area under the receiver operating characteristic curve) was 0.879 (95% CI, 0.816-0.942). The scale's cutoff point of ≥4 provided a specificity and sensitivity of 87.2% (95% CI, 84.1-89.9) and 77.1% (95% CI, 65.6-86.3), respectively. In addition, the cutoff value resulted in a positive predictive and negative predictive value of 43.90% (95% CI, 37.76-50.24) and 96.70% (95% CI, 95.01-97.85), respectively. In regard to the scale's predictive value, performance was slightly higher among men (area under the curve [AUC], 0.916; 95% CI, 0.873-0.960) vs women (AUC, 0.805; 95% CI, 0.707-0.903).
In the Japan cohort, MCI status of participants was measured at baseline using only the Mini-Mental State Examination, which may have resulted in unreliable data. Also, the investigators were unable to adjust for education level across cohorts, which may have limited the findings considering education affects dementia risk.
Based on the findings, the investigators indicate that the MoPaRDS represents “a short and easily-administered office tool that despite its simplicity can nonetheless accurately screen for dementia risk in PD.”
Dawson BK, Fereshtehnejad S-M, Anang JBM, et al. Office-based screening for dementia in Parkinson disease: the Montreal Parkinson Risk of Dementia Scale in 4 longitudinal cohorts [published online March 26, 2018]. JAMA Neurol. doi: 10.1001/jamaneurol.2018.0254