Supplementary Material for: A systematic review comparing radiofrequency versus focused ultrasound pallidotomy in the treatment of Parkinson’s disease

Introduction: Focused ultrasound (FUS) pallidotomy is a promising new therapy for Parkinson’s disease (PD). The efficacy, motor outcomes, and side effects of FUS pallidotomy compared to radiofrequency (RF) pallidotomy are unknown. Methods: We performed a systematic review of the outcomes and side effect profiles of FUS versus RF pallidotomy in patients with PD. Results: Across four RF reports and one FUS report, putative contralateral UPDRS III scores were not significantly different following RF versus FUS pallidotomy. Across 18 RF and 2 FUS reports, mean failure rate was 14% following RF pallidotomy versus 24% following FUS pallidotomy. Across 25 RF and 3 FUS reports, cognitive deficit was significantly more prevalent following RF pallidotomy (p = 0.004). Conclusion: At present, limited data and heterogeneity in outcome reporting challenges comparisons of FUS and RF pallidotomy efficacy and safety. Available evidence suggests FUS pallidotomy may have broadly similar efficacy and lower risk of cognitive impairment relative to RF pallidotomy. Standardized reporting of post-lesion outcomes in future studies would improve power and rule out potential confounders of these results.