A BS TRACT: Objective: Real-life observational report of clinical efficacy of bilateral subthalamic stimulation (STN-DBS), apomorphine (APO), and intrajejunal levodopa infusion (IJLI) on quality of life, motor, and nonmotor symptoms (NMS) in Parkinson's disease (PD). Methods: In this prospective, multicenter, international, reallife cohort observation study of 173 PD patients undergoing STN-DBS (n = 101), IJLI (n = 33), or APO (n = 39) were followed-up using PDQuestionnaire-8, NMSScale (NMSS), Unified PD Rating Scale (UPDRS)-III, UPDRS-IV, and levodopa equivalent daily dose (LEDD) before and 6 months after intervention. Outcome changes were analyzed with Wilcoxon signed-rank or paired t test when parametric tests were applicable. Multiple comparisons were corrected (multiple treatments/scales). Effect strengths were quantified with relative changes, effect size, and number needed to treat. Analyses were computed before and after propensity score matching, balancing demographic and clinical characteristics. Results: In all groups, PDQuestionnaire-8, UPDRS-IV, and NMSS total scores improved significantly at follow-up. ---Levodopa equivalent daily dose was significantly reduced after STN-DBS. Explorative NMSS domain analyses resulted in distinct profiles: STN-DBS improved urinary/ sexual functions, mood/cognition, sleep/fatigue, and the miscellaneous domain. IJLI improved the 3 latter domains and gastrointestinal symptoms. APO improved mood/ cognition, perceptual problems/hallucinations, attention/ memory, and the miscellaneous domain. Overall, STN-DBS and IJLI seemed favorable for NMSS total score, and APO favorable for neuropsychological/neuropsychiatric NMS and PDQuestionnaire-8 outcome.Conclusions: This is the first comparison of quality of life, nonmotor. and motor outcomes in PD patients undergoing STN-DBS, IJLI, and APO in a real-life cohort. Distinct effect profiles were identified for each treatment option. Our results highlight the importance of holistic nonmotor and motor symptoms assessments to personalize treatment choices.

BACKGROUND STN-DBS is well established to improve motor symptoms and quality of life in patients with PD. While non-motor symptoms are crucial for quality of life in these patients, only neuropsychiatric and neuropsychological symptoms have been systematically studied in a longitudinal design thus far. However, these are only a part of the spectrum of non-motor symptoms in PD. We hypothesized that STN-DBS is associated with a beneficial effect on a range of non-motor symptoms. METHODSIn this multicenter, open, prospective, international study we investigated non-motor effects of STN-DBS in "real-life" use. We evaluated Non-motor Symptom Scale, and Questionnaire, PD Questionnaire-8, Scales for Outcomes of PD motor examination and complications, and activities of daily living preoperatively and at 6 months follow-up in 60 consecutive patients (35 male, mean age: 61.64 ±7.84 years, mean disease duration: 10.45 ±4.22 years) undergoing STN-DBS. RESULTSAll outcomes improved significantly at 6 months follow-up (PD Questionaire-8, p=0.006; activities of daily living, p=0.012; all others, p<0.001; Wilcoxon signedrank, respectively paired t-test; Bonferroni-correction). Post-hoc analyses of Nonmotor Symptom Scale domains showed a significant reduction of sleep/fatigue and miscellaneous domains (p≤0.001), perceptual problems/hallucinations (p=0.036), and urinary (p=0.018) scores. Effect sizes were "moderate" effect for Non-motor Non-motor effects of subthalamic DBS -5 -Symptom Scale, and motor complications, "large" for motor examination, and "small" for other outcomes. CONCLUSIONSThis study provides first evidence that bilateral STN-DBS improves non-motor burden in patients with PD and opens the door to a more balanced evaluation of DBS outcomes. Further randomized studies are needed to confirm these findings and compare DBS non-motor effects to other therapies such as infusion based treatments of advanced PD.

Deep brain stimulation of the subthalamic nucleus improves non-motor symptoms in Parkinson’s disease, but with considerable inter-individual variability. Petry-Schmelzer et al. show that neurostimulation in specific subregions of the subthalamic nucleus has differential effects on mood/apathy, attention/memory and sleep-related outcomes. Neurostimulation could thus be tailored to patients’ individual non-motor profiles.

UK National Health Service.