Two Surveys for Diagnosing Mild Cognitive Impairment in Parkinson's Disease
Approximately one-third of patients with Parkinson’s disease (PD) have dementia, leading to severe quality-of-life impairments in addition to those that are caused by the motor symptoms of PD. It has been previously been shown that patients with mild cognitive impairment (MCI) early in the course of PD are at increased risk of developing dementia. However, early diagnosis of MCI has been challenging until now.
The Movement Disorders Journal has published an article by Emmie W. Koevets, MSC; Ben Schmand, PhD, and Gert J. Geurtsen PhD evaluating the accuracy of two cognitive rating scales for patients with PD (Mov Disord Clin Pract. 2018:published online February 7, 2018). Using ROC under-the-curve analysis, the authors compared the Parkinson’s Disease-Cognitive Rating Scale (PD-CRS) and the Mattis Dementia Rating Scale-2 (MDRS-2) against the consensus criteria of the International Parkinson and Movement Disorder Society for diagnosis of MCI in PD.
Both scales were administered to 125 patients with PD and 75 healthy subjects, and 27% of patients with PD were found to have MCI. Raw scores for the PD-CRS and MDRS-2 showed 83% and 81% under the curve areas respectively. At the optimal cutoffs, sensitivity for the PD-CRS was 88%, suggesting that this survey will identify the majority of patients who have MCI in PD; specificity was 64%. The MDRS-2 was less sensitive (69%) and more specific (77%). Demographic correction of scores did not affect the sensitivity and specificity of either rating scale.
The authors conclude that both scales are suitable for identifying which patients with PD have MCI.