@article{KremerPauwelsPozzietal.2021,
  author    = {Kremer, Naomi I. and Pauwels, Rik W. J. and Pozzi, Nicol{\`o} G. and Lange, Florian and Roothans, Jonas and Volkmann, Jens and Reich, Martin M.},
  title     = {Deep Brain Stimulation for Tremor: Update on Long-Term Outcomes, Target Considerations and Future Directions},
  series = {Journal of Clinical Medicine},
  volume    = {10},
  journal   = {Journal of Clinical Medicine},
  number    = {16},
  issn      = {2077-0383},
  doi       = {10.3390/jcm10163468},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244982},
  year      = {2021},
  abstract  = {Deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus is one of the main advanced neurosurgical treatments for drug-resistant tremor. However, not every patient may be eligible for this procedure. Nowadays, various other functional neurosurgical procedures are available. In particular cases, radiofrequency thalamotomy, focused ultrasound and radiosurgery are proven alternatives to DBS. Besides, other DBS targets, such as the posterior subthalamic area (PSA) or the dentato-rubro-thalamic tract (DRT), may be appraised as well. In this review, the clinical characteristics and pathophysiology of tremor syndromes, as well as long-term outcomes of DBS in different targets, will be summarized. The effectiveness and safety of lesioning procedures will be discussed, and an evidence-based clinical treatment approach for patients with drug-resistant tremor will be presented. Lastly, the future directions in the treatment of severe tremor syndromes will be elaborated.},
  language  = {en}
}
@article{Gonzalez‐EscamillaMuthuramanReichetal.2019,
  author    = {Gonzalez-Escamilla, Gabriel and Muthuraman, Muthuraman and Reich, Martin M. and Koirala, Nabin and Riedel, Christian and Glaser, Martin and Lange, Florian and Deuschl, G{\"u}nther and Volkmann, Jens and Groppa, Sergiu},
  title     = {Cortical network fingerprints predict deep brain stimulation outcome in dystonia},
  series = {Movement Disorders},
  volume    = {34},
  journal   = {Movement Disorders},
  number    = {10},
  doi       = {10.1002/mds.27808},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-213532},
  pages     = {1536 -- 1545},
  year      = {2019},
  abstract  = {Background Deep brain stimulation (DBS) is an effective evidence-based therapy for dystonia. However, no unequivocal predictors of therapy responses exist. We investigated whether patients optimally responding to DBS present distinct brain network organization and structural patterns. Methods From a German multicenter cohort of 82 dystonia patients with segmental and generalized dystonia who received DBS implantation in the globus pallidus internus, we classified patients based on the clinical response 3 years after DBS. Patients were assigned to the superior-outcome group or moderate-outcome group, depending on whether they had above or below 70\% motor improvement, respectively. Fifty-one patients met MRI-quality and treatment response requirements (mean age, 51.3 ± 13.2 years; 25 female) and were included in further analysis. From preoperative MRI we assessed cortical thickness and structural covariance, which were then fed into network analysis using graph theory. We designed a support vector machine to classify subjects for the clinical response based on individual gray-matter fingerprints. Results The moderate-outcome group showed cortical atrophy mainly in the sensorimotor and visuomotor areas and disturbed network topology in these regions. The structural integrity of the cortical mantle explained about 45\% of the DBS stimulation amplitude for optimal response in individual subjects. Classification analyses achieved up to 88\% of accuracy using individual gray-matter atrophy patterns to predict DBS outcomes. Conclusions The analysis of cortical integrity, informed by group-level network properties, could be developed into independent predictors to identify dystonia patients who benefit from 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}
}