Analysis of deep brain stimulation of the subthalamic nucleus (STN-DBS) in patients with monogenic PRKN and LRRK2 forms of Parkinson?s disease

Introduction: Deep brain stimulation of the subthalamic nucleus (STN-DBS) is the most common surgical treat-ment for Parkinson's disease (PD). Patient selection and genetic background can modify the response to this treatment. The objective of this study was to compare both clinical and pharmacologic response of STN-DBS between patients with monogenic forms of PD and non-mutation carriers with idiopathic PD. Methods: A retrospective analysis among 23 carriers of genetic mutations (8 PRKN and 15 LRRK2) and 74 pa-tients with idiopathic PD was performed. The study included comparisons of Unified Parkinson's Disease Rating Scale (UPDRS) II and III scores, Schwab and England (S&E) scale values, Hoehn & Yahr (H&Y) stage scores, and equivalent doses of levodopa before and after the surgery (at 6 and 12 months) between both groups. Results: The mean age at the time in which STN-DBS was performed was 59.5 +/- 8.6. Linear mixed models showed the absence of statistically significant differences between mutation and non-mutation carriers regarding levo-dopa doses (p = 0.576), UPDRS II (p = 0.956) and III (p = 0.512) scores, and S&E scale scores (0.758). The only difference between the two groups was observed with respect to H&Y stage in OFF medication/ON stimulation status being lower in genetic PD at 6 months after surgery (p = 0.030). Conclusion: Clinical and pharmacological benefit of bilateral STN-DBS is similar in PRKN and LRRK2 mutation carriers and patients with idiopathic PD.