Is there a difference in the post-operative motor function of individuals with Parkinson’s Disease submitted to Deep Brain Stimulation surgery according to the disease severity?

Introduction: Parkinson’s Disease (PD) is a progressive neurodegenerative disease that brings several motor and nonmotor symptoms. This clinical condition can be improved with Deep Brain Stimulation Surgery (DBS). Hoehn & Yahr Scale (HY) and Unified Parkinson’s Disease Rating Scale (UPDRS) are reference scales that help the decision of making the procedure. Aim: To investigate if there is a difference in the post-operative UPDRS -Part III of individuals with PD submitted to DBS surgery according to their HY score (disease severity) presented before the surgery. Methods: Cross-sectional study with individuals with PD who were submitted to DBS. They were separated into 3 groups: HY 2 (bilateral disease with adequate balance), HY 2.5 (bilateral disease with recovery in the Pull test), and HY 3 and 4 (bilateral disease with postural instability). Disease stage was investigated with HY scores and motor function with UPDRS -Part III scores. One-way analyses of variance (ANOVAs) followed by Bonferroni posthoc tests were employed to investigate differences between the groups regarding the UPDRS -Part III scores. Results: 45 individuals with 59±9.6 years on the surgery date participated in the study. It was observed a statistically significant difference in UPDRS -Part III between HY 3 and 4 group and HY 2 group (20.5±7.0 vs 11.8±4.5) and between HY 3 and 4 group and HY 2.5 group (20.5±7.0 vs 12.1±6.6). Conclusion: The UPDRS of individuals who did DBS when they were on HY 3 and 4 were 40% higher than the patients who did it in HY 2 or 2.5 stages. Thus, it has been hypothesized that DBS should be done before the individual starts to present mild to moderate postural mild instability.