@article{SteigerwaldMuellerJohannesetal.2016,
  author    = {Steigerwald, Frank and M{\"u}ller, Lorenz and Johannes, Silvia and Matthies, Cordula and Volkmann, Jens},
  title     = {Directional deep brain stimulation of the subthalamic nucleus: a pilot study using a novel neurostimulation device},
  series = {Movement Disorders},
  volume    = {31},
  journal   = {Movement Disorders},
  number    = {8},
  doi       = {10.1002/mds.26669},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187683},
  pages     = {1240-1243},
  year      = {2016},
  abstract  = {Introduction A novel neurostimulation system allows steering current in horizontal directions by combining segmented leads and multiple independent current control. The aim of this study was to evaluate directional DBS effects on parkinsonian motor features and adverse effects of subthalamic neurostimulation. Methods Seven PD patients implanted with the novel directional DBS system for bilateral subthalamic DBS underwent an extended monopolar review session during the first postoperative week, in which current thresholds were determined for rigidity control and stimulation-induced adverse effects using either directional or ring-mode settings. Results Effect or adverse effect thresholds were modified by directional settings for each of the 14 STN leads. Magnitude of change varied markedly between leads, as did orientation of optimal horizontal current steering. Conclusion Directional current steering through chronically implanted segmented electrodes is feasible, alters adverse effect and efficacy thresholds in a highly individual manner, and expands the therapeutic window in a monopolar review as compared to ring-mode DBS.},
  language  = {en}
}
@article{PasosSteigerwaldReichetal.2019,
  author    = {Pasos, Uri E. Ramirez and Steigerwald, Frank and Reich, Martin M. and Matthies, Cordula and Volkmann, Jens and Reese, Ren{\´e}},
  title     = {Levodopa modulates functional connectivity in the upper beta band between bubthalamic nucleus and muscle activity in tonic and phasic motor activity patterns in Parkinson's disease},
  series = {Frontiers in Human Neuroscience},
  volume    = {13},
  journal   = {Frontiers in Human Neuroscience},
  number    = {223},
  doi       = {10.3389/fnhum.2019.00223},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201540},
  year      = {2019},
  abstract  = {Introduction: Striatal dopamine depletion disrupts basal ganglia function and causes Parkinson's disease (PD). The pathophysiology of the dopamine-dependent relationship between basal ganglia signaling and motor control, however, is not fully understood. We obtained simultaneous recordings of local field potentials (LFPs) from the subthalamic nucleus (STN) and electromyograms (EMGs) in patients with PD to investigate the impact of dopaminergic state and movement on long-range beta functional connectivity between basal ganglia and lower motor neurons. Methods: Eight PD patients were investigated 3 months after implantation of a deep brain stimulation (DBS)-system capable of recording LFPs via chronically-implanted leads (Medtronic, ACTIVA PC+S®). We analyzed STN spectral power and its coherence with EMG in the context of two different movement paradigms (tonic wrist extension vs. alternating wrist extension and flexion) and the effect of levodopa (L-Dopa) intake using an unbiased data-driven approach to determine regions of interest (ROI). Results: Two ROIs capturing prominent coherence within a grand average coherogram were identified. A trend of a dopamine effect was observed for the first ROI (50-150 ms after movement start) with higher STN-EMG coherence in medicated patients. Concerning the second ROI (300-500 ms after movement start), an interaction effect of L-Dopa medication and movement task was observed with higher coherence in the isometric contraction task compared to alternating movements in the medication ON state, a pattern which was reversed in L-Dopa OFF. Discussion: L-Dopa medication may normalize functional connectivity between remote structures of the motor system with increased upper beta coherence reflecting a physiological restriction of the amount of information conveyed between remote structures. This may be necessary to maintain simple movements like isometric contraction. Our study adds dynamic properties to the complex interplay between STN spectral beta power and the nucleus' functional connectivity to remote structures of the motor system as a function of movement and dopaminergic state. This may help to identify markers of neuronal activity relevant for more individualized programming of DBS therapy.},
  language  = {en}
}
@article{BinderLangePozzietal.2023,
  author    = {Binder, Tobias and Lange, Florian and Pozzi, Nicol{\`o} and Musacchio, Thomas and Daniels, Christine and Odorfer, Thorsten and Fricke, Patrick and Matthies, Cordula and Volkmann, Jens and Capetian, Philipp},
  title     = {Feasibility of local field potential-guided programming for deep brain stimulation in Parkinson's disease: a comparison with clinical and neuro-imaging guided approaches in a randomized, controlled pilot trial},
  series = {Brain Stimulation},
  volume    = {16},
  journal   = {Brain Stimulation},
  number    = {5},
  doi       = {10.1016/j.brs.2023.08.017},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350280},
  pages     = {1243-1251},
  year      = {2023},
  abstract  = {Highlights • Beta-Guided programming is an innovative approach that may streamline the programming process for PD patients with STN DBS. • While preliminary findings from our study suggest that Beta Titration may potentially mitigate STN overstimulation and enhance symptom control, • Our results demonstrate that beta-guided programming significantly reduces programming time, suggesting it could be efficiently integrated into routine clinical practice using a commercially available patient programmer. Background Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for advanced Parkinson's disease (PD). Clinical outcomes after DBS can be limited by poor programming, which remains a clinically driven, lengthy and iterative process. Electrophysiological recordings in PD patients undergoing STN-DBS have shown an association between STN spectral power in the beta frequency band (beta power) and the severity of clinical symptoms. New commercially-available DBS devices now enable the recording of STN beta oscillations in chronically-implanted PD patients, thereby allowing investigation into the use of beta power as a biomarker for DBS programming. Objective To determine the potential advantages of beta-guided DBS programming over clinically and image-guided programming in terms of clinical efficacy and programming time. Methods We conducted a randomized, blinded, three-arm, crossover clinical trial in eight Parkinson's patients with STN-DBS who were evaluated three months after DBS surgery. We compared clinical efficacy and time required for each DBS programming paradigm, as well as DBS parameters and total energy delivered between the three strategies (beta-, clinically- and image-guided). Results All three programming methods showed similar clinical efficacy, but the time needed for programming was significantly shorter for beta- and image-guided programming compared to clinically-guided programming (p < 0.001). Conclusion Beta-guided programming may be a useful and more efficient approach to DBS programming in Parkinson's patients with STN-DBS. It takes significantly less time to program than traditional clinically-based programming, while providing similar symptom control. In addition, it is readily available within the clinical DBS programmer, making it a valuable tool for improving current clinical practice.},
  language  = {en}
}