Evaluation of a programming algorithm for deep brain stimulation in dystonia used in a double-blind, sham-controlled multicenter study.

Background: Programming deep brain stimulation in dystonia is difficult because of the delayed benefits and absence of evidence-based guidelines. Therefore, we evaluated the efficacy of a programming algorithm applied in a double-blind, sham-controlled multicenter study of pallidal deep brain stimulation in dystonia.
Methods: A standardized monopolar review to identify the contact with the best acute antidystonic effect was applied in 40 patients, who were then programmed 0.5 V below the adverse effect threshold and maintained on these settings for at least 3 months, if tolerated. If no acute effects were observed, contact selection was based on adverse effects or anatomical criteria. Three-year follow-up data was available for 31 patients, and five-year data for 32 patients. The efficacy of the algorithm was based on changes in motor scores, adverse events, and the need for reprogramming.
Results: The mean (±standard deviation) dystonia motor score decreased by 73 ± 24% at 3 years and 63 ± 38% at 5 years for contacts that exhibited acute improvement of dystonia ( n  = 17) during the monopolar review. Contacts without acute benefit improved by 58 ± 30% at 3 years ( n  = 63) and 53 ± 31% at 5 years ( n  = 59). Interestingly, acute worsening or induction of dystonia/dyskinesia ( n  = 9) correlated significantly with improvement after 3 years, but not 5 years.
Conclusions: Monopolar review helped to detect the best therapeutic contact in approximately 30% of patients exhibiting acute modulation of dystonic symptoms. Acute improvement, as well as worsening of dystonia, predicted a good long-term outcome, while induction of phosphenes did not correlate with outcome.
Trial Registration: ClinicalTrials.gov NCT00142259.
Competing Interests: Competing interestsAll authors report no potential conflict of interest regarding this manuscript. Over the last 12 months FS report grants and personal fees from Boston Scientific, a research grant from Medtronic and personal fees from Abbott for educational trainings, JV received grants from Medtronic and Boston Scientific as well as personal fees from Medtronic, Abbott, Boston Scientifc, UCB, Merz, Allergan, TEVA, Novartis, Abbvie, Grünenthal and Newronika. GD has received lecture fees from Boston Scientific and has been serving as a consultant for Boston Scientific. He received royalties from Thieme publishers. He is a government employee and receives through his institution funding for his research from the German Research Council, the German Ministery of Education and Research and Medtronic. JVe reports grants and consultancies from Abbott and Boston Scientific over the last 12 months. CWI reports honoraria from Allergan Inc., Merz Pharmaceutical and Ipsen Pharm and travel grants from Desitin over the last 12 months. AS has been serving as a consultant for Medtronic Inc., Boston Scientific, St. Jude Medical, Grünenthal and has received lecture fees from Abbvie, Boston Scientific, St. Jude Medical, Medtronic Inc., UCB, MEDA Pharma, Teva Pharma, and GlaxoSmithKline. AS is a government employee and receives through his institution funding for his research from the German Research Council, the German Ministery of Education and Health, and the Gossweiler Foundation. JM reports honoraria from Merz Pharmaceutical over the last 12 months. AKü reports consultancies for Boston Scientific and Abbott. AKu reports honoraria from Zamson and Merz DF, JVH, MN and WE report no financial disclosure over the last 12 months.
(© The Author(s) 2019.)