Hybrid Deep Brain Stimulation for Parkinson’s Disease and Dystonia Improves Side Effects, Maintaining Clinical Benefit

Abstract

Introduction: Deep brain stimulation (DBS) in movement disorders does not always achieve optimal symptomatic control. Most common issues involve suboptimal electrode positioning and target stimulation and troublesome side effects limiting the therapeutic window. Recently approved implantable pulse generators (IPG) allow for pulse widths lower than 60 μs, increasing the therapeutic window, and current steering. These new constant-current IPG (CC-IPG), in addition to these characteristics, have rechargeable, thus longer duration, batteries. This work aims to describe a tertiary center’s experience with replacing a constant-voltage stimulation non-rechargeable implantable pulse generator (CV-IPG), at the end of its battery’s lifespan, with a CC-IPG, with more options in pulse duration changes and multiplesource current steering. Methods: A retrospective review of the clinical records of patients submitted to DBS who had their CV-IPG replaced with CC-IPG was performed, documenting reason for preference, stimulation parameters, clinical benefit pre and post-replacement and side effects.
Results: Six patients who fulfilled the criteria were identified, four with Parkinson’s disease (PD) and two with dystonia. The reasons for preference were: stimulation side effects (2), suboptimal benefit (1), long battery duration (3). Side effects were improved by using a 30 μs pulse in two patients. Current steering allowed the shortening of OFF periods in 1 PD patient. One patient with dystonia had initial decrease in clinical benefit but recovered after amplitude correction according to impedance. The other two patients remained stable post-replacement. Conclusion: Replacement of CV-IPG with CC-IPG proved feasible and safe, with non-inferior clinical benefit, additionally providing pulse lowering and current steering strategies for solving suboptimal results with DBS.