Office-based screen predicts dementia in Parkinson’s disease

A positive screen result – a cut-off of four or above – showed a sensitivity of 77.1% and a specificity of 87.2%. The positive predictive value was 43.9% and the negative predictive value was 96.7%, and the overall area under the receiver operating characteristic curve was 0.877.

Benjamin K. Dawson, from the department of neurology and neurosurgery at McGill University, Montreal, and coauthors said a previous study using a combination of lumbar puncture, dopamine transporter scanning with [¹²³I]FP-CIT single photon emission CT (DaTscan), and clinical markers had an area under the curve of 0.80, while clinical-genetic risk score that included an analysis of GBA mutations had reported an AUC of 0.88.

The Montreal Parkinson’s Risk of Dementia Scale includes eight items: age below 70 years, male sex, falls and/or freezing, bilateral disease onset, history suggestive of rapid eye movement sleep behavior disorder, orthostatic hypotension, mild cognitive impairment, and visual hallucinations.

The authors noted that the risk scores were lower when the cohort was limited to patients without mild cognitive impairment. Because sex was also such a strong risk factor for dementia, the authors divided the results according to sex and found that the scale did perform somewhat better in men.