What Level of Parkinson’s Disease Severity Is Associated with Significant Differences in Cognitive Function? (P5.258)

OBJECTIVE: To investigate the key thresholds in Parkinson’s disease (PD) severity associated with significant differences in cognitive function. BACKGROUND: Cognitive impairment is common in PD. Montreal Cognitive Assessment (MoCA) scores below 26 suggest cognitive impairment. The levels of PD severity generally associated with significant differences of cognitive function are poorly understood. DESIGN/METHODS: The University of Maryland PD Center systematically enrolls PD patients in a prospective longitudinal database. Assessments include the MoCA, UPDRS, and Hoehn & Yahr (HY) staging. Mean MoCA scores were calculated for 10-point increments on the Total UPDRS and for HY stages. ANOVA was performed to determine significant cognitive changes by HY staging and Total UPDRS increments. RESULTS: MoCA ratings were available for 234 patients with Total UPDRS and 155 patients with HY staging. Based on 10-point increments of Total UPDRS, the mean MoCA score showed the earliest statistically significant difference between UPDRS levels 30-39 and 40-49 (MoCA 27.2(1.8) vs. 25.1(4.0); p 3), a significant difference in MoCA score was observed between HY stages 2.5 and 3 (MoCA 25.6(3.5) vs. 21.8(4.7); p<.05). CONCLUSIONS: The transition of UPDRS ratings from the 30’s to the 40’s and from HY stages 2.5 to 3 is associated with a difference in cognition indicative of differences between intact and mild cognitive impairment (MoCA<26). We have previously reported that similar UPDRS and HY cut-points mark the transition from intact function to disability. The results of this study highlight the importance of these thresholds as markers of change not only in general PD severity and disability, but also in differences in cognitive function. Study Supported by: Disclosure: Dr. Lachner has nothing to disclose. Dr. Armstrong has received personal compensation for activities with the American Academy of Neurology and the Eli Lilly & Company. Dr. Armstrong has received research support from Abbott. Dr. Gruber-Baldini has nothing to disclose. Dr. Barr has nothing to disclose. Dr. Fischman has received personal compensation for activities with Neura, Pfizer Inc., Forest Laboratories, Inc., Ortho-McNeil, GlaxoSmithKline Inc., BI, Novartis, and Allergan Inc. Dr. Reich has received royalty payments from Movement Disorders: 100 Instructive Cases. Dr. Reich has received research support from NINDS, Chiltern, Synosia, and Phytopharm. Dr. Weiner has nothing to disclose. Dr. Shulman has received personal compensation in an editorial capacity for the AAN Neurology Now patient book series. Dr. Shulman has received research support from the National Institutes of Health, the Michael J Fox Foundation and Teva Neuroscience.