The utility of the Mattis Dementia Rating Scale in Parkinson's disease mild cognitive impairment

Background: The Movement Disorders Society (MDS) recently proposed guidelines for diagnosis of mild cognitive impairment in Parkinson's disease (PD-MCI) that includes two assessment levels: abbreviated (Level I) and comprehensive (Level II). The aim of this study was to determine the utility of the Mattis Dementia Rating Scale (MDRS), a recommended Level I test, for detecting Level II PD-MCI diagnosis. Methods: The study sample included 30 patients diagnosed with PD-MCI based on Level II MDS criteria and 68 PD patients with normal cognition (PD-NC). Receiver operator curve (ROC) analyses were generated to measure the sensitivity and specificity of various MDRS cutoff scores. To examine the utility of the MDRS as a screening tool, the optimal cutoff point was defined as the lowest value providing >= 80% sensitivity. For use of the MDRS as a diagnostic tool, the optimal cutoff point was defined as the highest value providing >= 80% specificity. Results: ROC analyses showed that the optimal MDRS cutoff score for screening purposes and diagnostic purposes were <= 140 and <= 137, respectively. However, an examination of sensitivity/specificity values for the screening cutoff scores suggested that a total score of <= 139 for screening purposes yielded a better balance between sensitivity (77%) and specificity (65%). Conclusions: In a clinical setting, in which detection of PD-MCI may be important, a total MDRS score of <= 139 can be used to detect PD-MCI. In research and other settings in which diagnostic certainty is more important, a score of <= 137 may be more useful. Published by Elsevier Ltd.