Long-lasting concordance between imaging-guided and clinical-based STN-DBS programming enhances motor and axial...

IntroductionSubthalamic deep brain stimulation (STN-DBS) improves Parkinson's disease motor symptoms. Directional leads can extend the therapeutic window, despite further increasing programming complexity. Lead placement visualization software can facilitate STN-DBS programming, especially in contact selection process. We investigated the extent and impact on motor outcomes of the concordance between imaging-suggested (IGP) and standard clinical-programming (CP) selected stimulation contacts three years after surgery.MethodsThirty-five PD patients with bilateral STN-DBS were enrolled. Lead localization was reconstructed using Brainlab™. For each electrode, the predicted optimal vertical contact and, when applicable, directionality was identified and compared with stimulation parameters clinically activated three years post-surgery. Concordance, agreement and similarity IGP/CP metrics were calculated for both contact level and directionality. Postoperative changes in motor symptom severity were compared between concordant and discordant IGP/CP groups.ResultsThree years after surgery, IGP/CP concordance was 77.6% for active stimulation contact level and 66.7% for directionality. IGP reliably identified contacts and directional segments avoided by CP for chronic stimulation (negative predictive value 0.85 and 0.72, respectively). No significant difference was found in motor outcomes based on IGP/CP contact level concordance. Nonetheless, superior benefit in overall motor function and axial impairment (including speech) were reported in patients with clinically-activated directional stimulation concordant with that suggested by visual reconstruction.ConclusionsVisualization software can simplify STN-DBS programming, especially by reducing the number of contacts warranting systematic clinical testing via monopolar review. Moreover, the combination of visualization and directional stimulation technologies can further improve outcomes, especially of those symptoms, like axial/speech impairment, often challenging subthalamic chronic stimulation.