6 results on '"Saskia Elben"'
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2. Differential modulation of STN-cortical and cortico-muscular coherence by movement and levodopa in Parkinson's disease.
- Author
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Jan Hirschmann, Tolga E. özkurt, Markus Butz, M. Homburger, Saskia Elben, C. J. Hartmann, Jan Vesper, Lars Wojtecki, and Alfons Schnitzler
- Published
- 2013
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3. Distinct oscillatory STN-cortical loops revealed by simultaneous MEG and local field potential recordings in patients with Parkinson's disease.
- Author
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Jan Hirschmann, Tolga E. özkurt, Markus Butz, M. Homburger, Saskia Elben, C. J. Hartmann, Jan Vesper, Lars Wojtecki, and Alfons Schnitzler
- Published
- 2011
- Full Text
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4. Unilateral deep brain stimulation suppresses alpha and beta oscillations in sensorimotor cortices
- Author
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Lena Storzer, Jan Vesper, Markus Butz, Georg Schmitz, Alfons Schnitzler, Lars Wojtecki, Saskia Elben, Jan Hirschmann, Omid Abbasi, and Tolga Esat Özkurt
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Male ,0301 basic medicine ,Deep brain stimulation ,Parkinson's disease ,Movement disorders ,Deep Brain Stimulation ,Cognitive Neuroscience ,medicine.medical_treatment ,Alpha (ethology) ,Stimulation ,03 medical and health sciences ,0302 clinical medicine ,Subthalamic Nucleus ,medicine ,Humans ,Aged ,medicine.diagnostic_test ,business.industry ,Magnetoencephalography ,Middle Aged ,medicine.disease ,nervous system diseases ,Alpha Rhythm ,Subthalamic nucleus ,surgical procedures, operative ,030104 developmental biology ,medicine.anatomical_structure ,nervous system ,Neurology ,Female ,Sensorimotor Cortex ,medicine.symptom ,Beta Rhythm ,business ,Neuroscience ,030217 neurology & neurosurgery ,Motor cortex - Abstract
Deep brain stimulation (DBS) is an established therapy to treat motor symptoms in movement disorders such as Parkinson's disease (PD). The mechanisms leading to the high therapeutic effectiveness of DBS are poorly understood so far, but modulation of oscillatory activity is likely to play an important role. Thus, investigating the effect of DBS on cortical oscillatory activity can help clarifying the neurophysiological mechanisms of DBS. Here, we aimed at scrutinizing changes of cortical oscillatory activity by DBS at different frequencies using magnetoencephalography (MEG). MEG data from 17 PD patients were acquired during DBS of the subthalamic nucleus (STN) the day after electrode implantation and before implanting the pulse generator. We stimulated the STN unilaterally at two different stimulation frequencies, 130 Hz and 340 Hz using an external stimulator. Data from six patients had to be discarded due to strong artefacts and two other datasets were excluded since these patients were not able to finalize the paradigm. After DBS artefact removal, power spectral density (PSD) values of MEG were calculated for each individual patient and averaged over the group. DBS at both 130 Hz and 340 Hz led to a widespread suppression of cortical alpha/beta band activity (8–22 Hz) specifically over bilateral sensorimotor cortices. No significant differences were observed between the two stimulation frequencies. Our finding of a widespread suppression of cortical alpha/beta band activity is particularly interesting as PD is associated with pathologically increased levels of beta band activity in the basal ganglia-thalamo-cortical circuit. Therefore, suppression of such oscillatory activity might be an essential effect of DBS for relieving motor symptoms in PD and can be achieved at different stimulation frequencies above 100 Hz. more...
- Published
- 2018
- Full Text
- View/download PDF
5. Distinct oscillatory STN-cortical loops revealed by simultaneous MEG and local field potential recordings in patients with Parkinson's disease
- Author
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Alfons Schnitzler, Saskia Elben, M. Homburger, Tolga Esat Özkurt, Lars Wojtecki, Christian J. Hartmann, Jan Hirschmann, Markus Butz, and Jan Vesper
- Subjects
Male ,Deep brain stimulation ,Deep Brain Stimulation ,Cognitive Neuroscience ,medicine.medical_treatment ,Local field potential ,Electroencephalography ,Functional Laterality ,Neurosurgical Procedures ,Premotor cortex ,Superior temporal gyrus ,Subthalamic Nucleus ,medicine ,Humans ,Muscle, Skeletal ,Evoked Potentials ,Aged ,Cerebral Cortex ,medicine.diagnostic_test ,Electromyography ,Magnetoencephalography ,Parkinson Disease ,Middle Aged ,Magnetic Resonance Imaging ,Electrodes, Implanted ,Electrophysiological Phenomena ,Alpha Rhythm ,Electrooculography ,Subthalamic nucleus ,medicine.anatomical_structure ,nervous system ,Neurology ,Cerebral cortex ,Data Interpretation, Statistical ,Female ,Beta Rhythm ,Tomography, X-Ray Computed ,Psychology ,Neuroscience ,Tomography, Optical Coherence - Abstract
Neuronal oscillations are assumed to play a pivotal role in the pathophysiology of Parkinson's disease (PD). Neurons in the subthalamic nucleus (STN) generate oscillations which are coupled to rhythmic population activity both in other basal ganglia nuclei and cortical areas. In order to localize these cortical areas, we recorded local field potentials (LFPs) and magnetoencephalography (MEG) simultaneously in PD patients undergoing surgery for deep brain stimulation (DBS). Patients were withdrawn from antiparkinsonian medication and recorded at rest. We scanned the entire brain for oscillations coherent with LFPs recorded from the STN with a frequency domain beamformer. Coherent activity in the low (12-20 Hz) and high (20-35 Hz) beta range was found in the ipsilateral sensorimotor and the premotor cortex. Coherence in the alpha range (7-12 Hz) was observed at various locations in the ipsilateral temporal lobe. In a subset of subjects, the superior temporal gyrus consistently showed coherent alpha oscillations. Our findings provide new insights into patterns of frequency-specific functional connectivity between basal ganglia and cortex and suggest that simultaneous inter-regional interactions may be segregated in the frequency domain. Furthermore, they demonstrate that simultaneous MEG-LFP recordings are a powerful tool to study interactions between brain areas in PD patients undergoing surgery for DBS. more...
- Published
- 2011
- Full Text
- View/download PDF
6. Differential modulation of STN-cortical and cortico-muscular coherence by movement and levodopa in Parkinson's disease
- Author
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Christian J. Hartmann, Jan Hirschmann, Alfons Schnitzler, Lars Wojtecki, Markus Butz, M. Homburger, Jan Vesper, Tolga Esat Özkurt, and Saskia Elben
- Subjects
Male ,Movement disorders ,Deep brain stimulation ,Parkinson's disease ,Cognitive Neuroscience ,medicine.medical_treatment ,Deep Brain Stimulation ,Movement ,Antiparkinson Agents ,Levodopa ,03 medical and health sciences ,0302 clinical medicine ,Subthalamic Nucleus ,Motor system ,Basal ganglia ,medicine ,Humans ,Muscle, Skeletal ,030304 developmental biology ,Aged ,0303 health sciences ,Resting state fMRI ,Electromyography ,Magnetoencephalography ,Parkinson Disease ,Middle Aged ,medicine.disease ,nervous system diseases ,Subthalamic nucleus ,nervous system ,Neurology ,Female ,medicine.symptom ,Primary motor cortex ,Psychology ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Previous research suggests that oscillatory coupling between cortex, basal ganglia and muscles plays an important role in motor behavior. Furthermore, there is evidence that oscillatory coupling is altered in patients with movement disorders such as Parkinson's disease (PD). In this study, we performed simultaneous magnetoencephalography (MEG), local field potential (LFP) and electromyogram (EMG) recordings in PD patients selected for therapeutic subthalamic nucleus (STN) stimulation. Patients were recorded (i) after withdrawal of anti-parkinsonian medication (OFF) and (ii) after levodopa administration (ON). We analyzed STN-cortical and cortico-muscular coherence during static forearm contraction and repetitive hand movement in order to evaluate modulations of coherence by movement and medication. Based on previous results from studies investigating resting state coherence in PD patients, we selected primary motor cortex (M1) and superior temporal gyrus (STG) as regions of interest. We found beta coherence between M1 and STN to be suppressed by administration of levodopa. M1-muscular coherence was strongly reduced in the alpha and beta band during repetitive movement compared to static contraction, but was unaffected by administration of levodopa. Strong STG-STN but not STG-muscular coherence could be observed in the alpha band. Coherence with STG was modulated neither by movement nor by medication. Finally, we found both M1-STN and M1-muscular beta coherence to be negatively correlated with UPDRS akinesia and rigidity sub-scores in the OFF state. The present study provides new insights into the functional roles of STN-cortical and cortico-muscular coherence and their relationship to PD symptoms. The results indicate that STN-cortical and cortico-muscular coupling are correlated, but can be modulated independently. Moreover, they show differences in their frequency-specific topography. We conclude that they represent partly independent sub-loops within the motor system. Given their negative correlation with akinesia, neither can be considered "antikinetic". more...
- Published
- 2012
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