@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{CanessaPozziArnulfoetal.2016,
  author    = {Canessa, Andrea and Pozzi, Nicol{\`o} G. and Arnulfo, Gabriele and Brumberg, Joachim and Reich, Martin M. and Pezzoli, Gianni and Ghilardi, Maria F. and Matthies, Cordula and Steigerwald, Frank and Volkmann, Jens and Isaias, Ioannis U.},
  title     = {Striatal Dopaminergic Innervation Regulates Subthalamic Beta-Oscillations and Cortical-Subcortical Coupling during Movements: Preliminary Evidence in Subjects with Parkinson's Disease},
  series = {Frontiers in Human Neuroscience},
  volume    = {10},
  journal   = {Frontiers in Human Neuroscience},
  number    = {611},
  doi       = {10.3389/fnhum.2016.00611},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164061},
  year      = {2016},
  abstract  = {Activation of the basal ganglia has been shown during the preparation and execution of movement. However, the functional interaction of cortical and subcortical brain areas during movement and the relative contribution of dopaminergic striatal innervation remains unclear. We recorded local field potential (LFP) activity from the subthalamic nucleus (STN) and high-density electroencephalography (EEG) signals in four patients with Parkinson's disease (PD) off dopaminergic medication during a multi-joint motor task performed with their dominant and non-dominant hand. Recordings were performed by means of a fully-implantable deep brain stimulation (DBS) device at 4 months after surgery. Three patients also performed a single-photon computed tomography (SPECT) with [123I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane (FP-CIT) to assess striatal dopaminergic innervation. Unilateral movement execution led to event-related desynchronization (ERD) followed by a rebound after movement termination event-related synchronization (ERS) of oscillatory beta activity in the STN and primary sensorimotor cortex of both hemispheres. Dopamine deficiency directly influenced movement-related beta-modulation, with greater beta-suppression in the most dopamine-depleted hemisphere for both ipsi- and contralateral hand movements. Cortical-subcortical, but not interhemispheric subcortical coherencies were modulated by movement and influenced by striatal dopaminergic innervation, being stronger in the most dopamine-depleted hemisphere. The data are consistent with a role of dopamine in shielding subcortical structures from an excessive cortical entrapment and cross-hemispheric coupling, thus allowing fine-tuning of movement.},
  language  = {en}
}
@article{GschmackMonoranuMaroufetal.2022,
  author    = {Gschmack, Eva and Monoranu, Camelia-Maria and Marouf, Hecham and Meyer, Sarah and Lessel, Lena and Idris, Raja and Berg, Daniela and Maetzler, Walter and Steigerwald, Frank and Volkmann, Jens and Gerlach, Manfred and Riederer, Peter and Koutsilieri, Eleni and Scheller, Carsten},
  title     = {Plasma autoantibodies to glial fibrillary acidic protein (GFAP) react with brain areas according to Braak staging of Parkinson's disease},
  series = {Journal of Neural Transmission},
  volume    = {129},
  journal   = {Journal of Neural Transmission},
  number    = {5-6},
  doi       = {10.1007/s00702-022-02495-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325161},
  pages     = {545-555},
  year      = {2022},
  abstract  = {Idiopathic Parkinson's disease (PD) is characterized by a progredient degeneration of the brain, starting at deep subcortical areas such as the dorsal motor nucleus of the glossopharyngeal and vagal nerves (DM) (stage 1), followed by the coeruleus-subcoeruleus complex; (stage 2), the substantia nigra (SN) (stage 3), the anteromedial temporal mesocortex (MC) (stage 4), high-order sensory association areas and prefrontal fields (HC) (stage 5) and finally first-order sensory association areas, premotor areas, as well as primary sensory and motor field (FC) (stage 6). Autoimmunity might play a role in PD pathogenesis. Here we analyzed whether anti-brain autoantibodies differentially recognize different human brain areas and identified autoantigens that correlate with the above-described dissemination of PD pathology in the brain. Brain tissue was obtained from deceased individuals with no history of neurological or psychiatric disease and no neuropathological abnormalities. Tissue homogenates from different brain regions (DM, SN, MC, HC, FC) were subjected to SDS-PAGE and Western blot. Blots were incubated with plasma samples from 30 PD patients and 30 control subjects and stained with anti-IgG antibodies to detect anti-brain autoantibodies. Signals were quantified. Prominent autoantigens were identified by 2D-gel-coupled mass spectrometry sequencing. Anti-brain autoantibodies are frequent and occur both in healthy controls and individuals with PD. Glial fibrillary acidic protein (GFAP) was identified as a prominent autoantigen recognized in all plasma samples. GFAP immunoreactivity was highest in DM areas and lowest in FC areas with no significant differences in anti-GFAP autoantibody titers between healthy controls and individuals with PD. The anti-GFAP autoimmunoreactivity of different brain areas correlates with the dissemination of histopathological neurodegeneration in PD. We hypothesize that GFAP autoantibodies are physiological but might be involved as a cofactor in PD pathogenesis secondary to a leakage of the blood-brain barrier.},
  language  = {en}
}
@article{LangeSteigerwaldMalzacheretal.2021,
  author    = {Lange, Florian and Steigerwald, Frank and Malzacher, Tobias and Brandt, Gregor Alexander and Odorfer, Thorsten Michael and Roothans, Jonas and Reich, Martin M. and Fricke, Patrick and Volkmann, Jens and Matthies, Cordula and Capetian, Philipp D.},
  title     = {Reduced Programming Time and Strong Symptom Control Even in Chronic Course Through Imaging-Based DBS Programming},
  series = {Frontiers in Neurology},
  volume    = {12},
  journal   = {Frontiers in Neurology},
  issn      = {1664-2295},
  doi       = {10.3389/fneur.2021.785529},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-249634},
  year      = {2021},
  abstract  = {Objectives: Deep brain stimulation (DBS) programming is based on clinical response testing. Our clinical pilot trial assessed the feasibility of image-guided programing using software depicting the lead location in a patient-specific anatomical model. Methods: Parkinson's disease patients with subthalamic nucleus-DBS were randomly assigned to standard clinical-based programming (CBP) or anatomical-based (imaging-guided) programming (ABP) in an 8-week crossover trial. Programming characteristics and clinical outcomes were evaluated. Results: In 10 patients, both programs led to similar motor symptom control (MDS-UPDRS III) after 4 weeks (medicationOFF/stimulationON; CPB: 18.27 ± 9.23; ABP: 18.37 ± 6.66). Stimulation settings were not significantly different, apart from higher frequency in the baseline program than CBP (p = 0.01) or ABP (p = 0.003). Time spent in a program was not significantly different (CBP: 86.1 ± 29.82\%, ABP: 88.6 ± 29.0\%). Programing time was significantly shorter (p = 0.039) with ABP (19.78 ± 5.86 min) than CBP (45.22 ± 18.32). Conclusion: Image-guided DBS programming in PD patients drastically reduces programming time without compromising symptom control and patient satisfaction in this small feasibility trial.},
  language  = {en}
}
@article{PoetterNergerReeseSteigerwaldetal.2017,
  author    = {P{\"o}tter-Nerger, Monika and Reese, Rene and Steigerwald, Frank and Heiden, Jan Arne and Herzog, Jan and Moll, Christian K. E. and Hamel, Wolfgang and Ramirez-Pasos, Uri and Falk, Daniela and Mehdorn, Maximilian and Gerloff, Christian and Deuschl, G{\"u}nther and Volkmann, Jens},
  title     = {Movement-Related Activity of Human Subthalamic Neurons during a Reach-to-Grasp Task},
  series = {Frontiers in Human Neuroscience},
  volume    = {11},
  journal   = {Frontiers in Human Neuroscience},
  number    = {436},
  doi       = {10.3389/fnhum.2017.00436},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170361},
  year      = {2017},
  abstract  = {The aim of the study was to record movement-related single unit activity (SUA) in the human subthalamic nucleus (STN) during a standardized motor task of the upper limb. We performed microrecordings from the motor region of the human STN and registered kinematic data in 12 patients with Parkinson's disease (PD) undergoing deep brain stimulation surgery (seven women, mean age 62.0 ± 4.7 years) while they intraoperatively performed visually cued reach-to-grasp movements using a grip device. SUA was analyzed offline in relation to different aspects of the movement (attention, start of the movement, movement velocity, button press) in terms of firing frequency, firing pattern, and oscillation. During the reach-to-grasp movement, 75/114 isolated subthalamic neurons exhibited movement-related activity changes. The largest proportion of single units showed modulation of firing frequency during several phases of the reach and grasp (polymodal neurons, 45/114), particularly an increase of firing rate during the reaching phase of the movement, which often correlated with movement velocity. The firing pattern (bursting, irregular, or tonic) remained unchanged during movement compared to rest. Oscillatory single unit firing activity (predominantly in the theta and beta frequency) decreased with movement onset, irrespective of oscillation frequency. This study shows for the first time specific, task-related, SUA changes during the reach-to-grasp movement in humans.},
  language  = {en}
}
@article{KirschHassinBaerMatthiesetal.2018,
  author    = {Kirsch, Anna Dalal and Hassin-Baer, Sharon and Matthies, Cordula and Volkmann, Jens and Steigerwald, Frank},
  title     = {Anodic versus cathodic neurostimulation of the subthalamic nucleus: A randomized-controlled study of acute clinical effects},
  series = {Parkinsonism and Related Disorders},
  volume    = {55},
  journal   = {Parkinsonism and Related Disorders},
  doi       = {10.1016/j.parkreldis.2018.05.015},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325820},
  pages     = {61-67},
  year      = {2018},
  abstract  = {Introduction Stimulation settings of deep brain stimulation (DBS) have evolved empirically within a limited parameter space dictated by first generation devices. There is a need for controlled clinical studies, which evaluate efficacy and safety of established programming practice against novel programming options provided by modern neurostimulation devices. Methods Here, we tested a polarity reversal from conventional monopolar cathodic to anodic stimulation in an acute double-blind, randomized, cross-over study in patients with PD implanted with bilateral STN DBS. The primary outcome measure was the difference between efficacy and side-effect thresholds (current amplitude, mA) in a monopolar review and the severity of motor symptoms (as assessed by MDS-UPDRS III ratings) after 30 min of continuous stimulation in the medication off-state. Results Effect and side effect thresholds were significantly higher with anodic compared to cathodic stimulation (3.36 ± 1.58 mA vs. 1.99 ± 1.37 mA; 6.05 ± 1.52 mA vs. 4.15 ± 1.13 mA; both p < 0.0001). However, using a predefined amplitude of 0.5 mA below the respective adverse effect threshold, blinded MDS-UPDRS-III-ratings were significantly lower with anodic stimulation (anodic: median 17 [min: 12, max: 25]; cathodic: 23 [12, 37]; p < 0.005). Conclusion Effective anodic stimulation requires a higher charge injection into the tissue, but may provide a better reduction of off-period motor symptoms within the individual therapeutic window. Therefore, a programming change to anodic stimulation may be considered in patients suffering from residual off-period motor symptoms of PD despite reaching the adverse effect threshold of cathodic stimulation in the subthalamic nucleus.},
  language  = {en}
}
@article{SteigerwaldTimmermannKuehnetal.2018,
  author    = {Steigerwald, Frank and Timmermann, Lars and K{\"u}hn, Andrea and Schnitzler, Alfons and Reich, Martin M. and Kirsch, Anna Dalal and Barbe, Michael Thomas and Visser-Vandewalle, Veerle and H{\"u}bl, Julius and van Riesen, Christoph and Groiss, Stefan Jun and Moldovan, Alexia-Sabine and Lin, Sherry and Carcieri, Stephen and Manola, Ljubomir and Volkmann, Jens},
  title     = {Pulse duration settings in subthalamic stimulation for Parkinson's disease},
  series = {Movement Disorders},
  volume    = {33},
  journal   = {Movement Disorders},
  doi       = {10.1002/mds.27238},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239402},
  pages     = {165-169},
  year      = {2018},
  abstract  = {Background Stimulation parameters in deep brain stimulation (DBS) of the subthalamic nucleus for Parkinson's disease (PD) are rarely tested in double-blind conditions. Evidence-based recommendations on optimal stimulator settings are needed. Results from the CUSTOM-DBS study are reported, comparing 2 pulse durations. Methods A total of 15 patients were programmed using a pulse width of 30 µs (test) or 60 µs (control). Efficacy and side-effect thresholds and unified PD rating scale (UPDRS) III were measured in meds-off (primary outcome). The therapeutic window was the difference between patients' efficacy and side effect thresholds. Results The therapeutic window was significantly larger at 30 µs than 60 µs (P = ·0009) and the efficacy (UPDRS III score) was noninferior (P = .00008). Interpretation Subthalamic neurostimulation at 30 µs versus 60 µs pulse width is equally effective on PD motor signs, is more energy efficient, and has less likelihood of stimulation-related side effects. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.},
  language  = {en}
}