Associations between Severity of Motor Function and Nonmotor Symptoms in Parkinson's Disease: A Post Hoc Analysis of the RECOVER Study

Background: RECOVER (NCT00474058), a double-blind, placebo-controlled trial in patients with Parkinson's disease (PD) and unsatisfactory early-morning motor symptom control, demonstrated significant improvements with rotigotine in early-morning motor function (Unified Parkinson's Disease Rating Scale [UPDRS] III), and nocturnal sleep disturbances (modified Parkinson's Disease Sleep Scale [PDSS-2]), and improvements in nonmotor symptoms (NMS; Non-Motor Symptom Scale [NMSS]). Methods: Post hoc analyses investigated the correlation between motor symptom and NMS severity in PD by evaluating associations between UPDRS Ill and both NMSS and PDSS-2 scores. Categories were defined for UPDRS Ill, NMSS, and PDSS-2 total scores; analyses were conducted for the full analysis set (n = 267). Results: There was a trend toward increasing PDSS-2 and NMSS total and domain scores with increasing UPDRS Ill category at baseline and end of maintenance (EoM). Pearson correlation coefficients between UPDRS III and both NMSS and PDSS-2 total and domain scores were r=0.12-0.44 (r(2)=0.01-0.19) at baseline, r = 0.05-0.38 (r(2) = 0.00-0.14) at EoM, and r = -0.02-0.36 (r(2) = 0.00-0.13) for change from baseline to EoM. Conclusion: There was only a small correlation between severity of early-morning motor symptoms and overall burden of NMS and nocturnal sleep disturbances in RECOVER, suggesting that motor symptoms and NMS originate, at least partly, from distinct pathophysiological pathways. (C) 2014 S. Karger AG, Basel