Burden of non-motor symptoms in Parkinson's disease patients predicts improvement in quality of life during treatment with levodopa-carbidopa intestinal gel

Background and purpose GLORIA, a registry conducted with 375 advanced Parkinson's disease patients treated with levodopa-carbidopa intestinal gel (LCIG) for 24 months in routine clinical care, demonstrated significant reductions from baseline in 'off' time and 'on' time with dyskinesia and improvements in the Non-Motor Symptom Scale (NMSS) total and individual domain scores, and in Parkinson's Disease Questionnaire 8 item (PDQ-8) total score. Methods Associations between baseline NMSS burden (NMSB), the multi-domain NMSS total score and the PDQ-8 total score were investigated for 233 patients. Baseline NMSB was assigned to five numerical categories defined by the NMSS total cutoff scores (0-20, 21-40, 41-60, 61-80 and >80). Pearson and Spearman correlations were calculated at month 24. Results The response of LCIG was assessed using validated criteria after 24 months. The proportion of patients decreasing >= 30 NMSS score points was 47% in the most affected NMSB category (NMSS total score > 80). A positive association was noted between baseline NMSB and NMSS total score (0.57, P < 0.0001), as well as between NMSS total score and PDQ-8 total score (0.46, P < 0.0001). Associations between improvements of the NMSS domain sleep/fatigue and PDQ-8 total score (0.32, P = 0.0001) as well as between the NMSS domain mood/cognition and PDQ-8 total score (0.37, P < 0.0001) were also shown. Conclusions This analysis demonstrated positive associations between NMSS baseline burden and improvements of non-motor symptoms. Improvements of non-motor symptoms were associated with improved quality of life in advanced parkinsonian patients during a 2-year treatment with LCIG and reflect the long-term non-motor efficacy of this treatment.