Motor outcomes in unilateral, bilateral rapid, and bilateral delayed staging deep brain stimulation for Parkinson's disease.

Background: Deep brain stimulation (DBS) is effective in managing motor symptoms in select cases of Parkinson's disease (PD). Nonetheless, the ideal timing for surgery and the comparative outcomes of unilateral versus bilateral DBS procedures remain under-researched areas.

Objective: We aimed to compare the impact of unilateral and bilateral DBS on the motor manifestations of PD using standardized Unified Parkinson's Disease Rating Scale Part-III (UPDRS-III).

Methods: We conducted a retrospective analysis of PD patients who underwent multidisciplinary DBS screening which made a formal recommendation for surgical approach. We compared unilateral, bilateral "rapid" (less than 2 months apart), and bilateral "staged" (5-11 months apart) implantation approaches. The study included 90 patients, 48 patients, and 42 patients from the 3 groups, respectively. The primary outcome was the percentage improvement in baseline off UPDRS-III scores compared to medication-off/DBS-on conditions at 3-6 months and 10-14 months post-surgery. Mann-Whitney U tests were used to compare scores within groups and across follow-up periods. The Kruskal-Wallis test assessed differences among groups. Furthermore, multiple regression analyses were performed to adjust for confounding variables.

Results: UPDRS-III scores improved significantly from baseline at both follow-up intervals regardless of the type of DBS staging approach. The Kruskal-Wallis test revealed no significant differences in UPDRS-III percentage improvement among groups at 3-6 months (p = 0.125) and 10-14 months (p = 0.298) post-DBS.

Conclusions: Our study revealed that in a single experienced DBS center which employed multidisciplinary screening, assignment to unilateral and bilateral DBS, both rapid and staged, targeting the STN or GPi, effectively improved motor symptoms for up to 14 months.