The Experts below are selected from a list of 120066 Experts worldwide ranked by ideXlab platform

John P Donoghue - One of the best experts on this subject based on the ideXlab platform.

S Marceglia - One of the best experts on this subject based on the ideXlab platform.

  • adaptive deep brain stimulation adbs controlled by Local Field Potential oscillations
    Experimental Neurology, 2013
    Co-Authors: Alberto Priori, Lorenzo Rossi, Guglielmo Foffani, S Marceglia
    Abstract:

    Abstract Despite their proven efficacy in treating neurological disorders, especially Parkinson's disease, deep brain stimulation (DBS) systems could be further optimized to maximize treatment benefits. In particular, because current open-loop DBS strategies based on fixed stimulation settings leave the typical parkinsonian motor fluctuations and rapid symptom variations partly uncontrolled, research has for several years focused on developing novel “closed-loop” or “adaptive” DBS (aDBS) systems. aDBS consists of a simple closed-loop model designed to measure and analyze a control variable reflecting the patient's clinical condition to elaborate new stimulation settings and send them to an “intelligent” implanted stimulator. The major problem in developing an aDBS system is choosing the ideal control variable for feedback. Here we review current evidence on the advantages of neurosignal-controlled aDBS that uses Local Field Potentials (LFPs) as a control variable, and describe the technology already available to create new aDBS systems, and the Potential benefits of aDBS for patients with Parkinson's disease.

  • thalamic single unit and Local Field Potential activity in tourette syndrome
    Movement Disorders, 2010
    Co-Authors: S Marceglia, Guglielmo Foffani, S Barbieri, Domenico Servello, Mauro Porta, Marco Sassi, Simona Mrakicsposta, Manuela Rosa, Alberto Priori
    Abstract:

    Deep brain stimulation (DBS) of the ventralis oralis (VO) complex of the thalamus improves tics in patients with Tourette syndrome (TS). To neurophysiologically describe the VO complex we recorded, in seven patients with TS under- going DBS electrode implantation, single-unit activity during surgery and Local Field Potentials (LFPs) a few days after sur- gery. Single unit recordings showed that the VO complex is characterized by a Localized pattern of bursting neuronal activ- ity. LFP spectra demonstrated that VO of TS patients has a prominent oscillatory activity at low frequencies (2-7 Hz) and in the a-band (8-13 Hz), and a virtually absent beta activity. In each patient, the main LFP frequency significantly corre- lated with single-unit interburst frequency. In conclusion, we observed an oscillatory bursting activity in the VO as target region in patients with severe TS undergoing DBS sur- gery. 2010 Movement Disorder Society

  • an electronic device for artefact suppression in human Local Field Potential recordings during deep brain stimulation
    Journal of Neural Engineering, 2007
    Co-Authors: Lorenzo Rossi, Guglielmo Foffani, S Marceglia, F Bracchi, S Barbieri
    Abstract:

    The clinical efficacy of high-frequency deep brain stimulation (DBS) for Parkinson's disease and other neuropsychiatric disorders likely depends on the modulation of neuronal rhythms in the target nuclei. This modulation could be effectively measured with Local Field Potential (LFP) recordings during DBS. However, a technical drawback that prevents LFPs from being recorded from the DBS target nuclei during stimulation is the stimulus artefact. To solve this problem, we designed and developed 'FilterDBS', an electronic amplification system for artefact-free LFP recordings (in the frequency range 2–40 Hz) during DBS. After defining the estimated system requirements for LFP amplification and DBS artefact suppression, we tested the FilterDBS system by conducting experiments in vitro and in vivo in patients with advanced Parkinson's disease undergoing DBS of the subthalamic nucleus (STN). Under both experimental conditions, in vitro and in vivo, the FilterDBS system completely suppressed the DBS artefact without inducing significant spectral distortion. The FilterDBS device pioneers the development of an adaptive DBS system retroacted by LFPs and can be used in novel closed-loop brain–machine interface applications in patients with neurological disorders.

Gyongyi Gaal - One of the best experts on this subject based on the ideXlab platform.

P. G. Overton - One of the best experts on this subject based on the ideXlab platform.

  • Identification of an excitatory amino acid-mediated component of the ventral tegmental area Local Field Potential response to medial prefrontal cortex stimulation: effect of acute d-amphetamine
    Journal of Neural Transmission, 2007
    Co-Authors: E. J. Dommett, J. Simpson, D. Clark, P. G. Overton
    Abstract:

    The induction of sensitisation to the behavioural effects of d-amphetamine – a model of drug addiction – involves the potentiation of exctiatory amino acid (EAA)-ergic synapses on dopaminergic neurons in the ventral tegmental area (VTA). Such potentiation has been reported as early as 2 hr post-injection, however earlier time points have not been assessed. Consequently, we examined the effects of systemic d-amphetamine on an EAA-mediated component of the VTA Local Field Potential response to stimulation of the medial prefrontal cortex, an EAAergic afferent critical for sensitisation, over the immediate 2 hr post-injection period. D-amphetamine and saline both depressed the amplitude of this component to a similar extent throughout the recording session. It is concluded that overt aspects of EAA-mediated potentiation appear to be delayed with respect to drug administration, which may have implications for sensitisation’s putative role in linking drug-related environmental stimuli and the central effects of the drug.

Andrea A Kuhn - One of the best experts on this subject based on the ideXlab platform.

  • neuromodulation effects of deep brain stimulation on beta rhythm a longitudinal Local Field Potential study
    Brain Stimulation, 2020
    Co-Authors: Yue Chen, Chen Gong, Ye Tian, Natasza Orlov, Jianguo Zhang, Yi Guo, Changqing Jiang, Hongwei Hao, Wolfjulian Neumann, Andrea A Kuhn
    Abstract:

    Abstract Background Deep brain stimulation (DBS) holds great promise in treating various brain diseases but its chronic therapeutic mechanisms are unclear. Objective To explore the immediate and chronic effects of DBS on brain oscillations, and understand how different sub-bands of oscillations may be related to symptom improvement in Parkinson's patients. Methods We carried out a longitudinal study to examine the effects of DBS on Local Field Potentials recorded by sensing-enabled neurostimulators in the subthalamic nuclei of Parkinson's patients, using a novel block-design stimulation paradigm. Results DBS significantly suppressed beta activity (13–35Hz) but the suppression effect appeared to gradually attenuate during a 6-month follow-up period after surgery (p = 0.002). However, beta suppression did not attenuate after repeated stimulation over several minutes (p > 0.110), suggesting that the changes in beta suppression may reflect a slow reconfiguration of neural pathways instead of habituation. Suppression of beta was also associated with clinical symptom improvement across subjects. Importantly, symptom-relevant features fell within the high beta band at month 1 but shifted to the low beta band at month 6, indicating that the high beta and the low beta oscillations may play different functional roles and respond differently to stimulation over the long-term treatment. Conclusion These data may advance understanding of chronic DBS effects on beta oscillations and their association with clinical improvement, offering novel insights to the therapeutic mechanisms of DBS.

  • oscillatory pallidal Local Field Potential activity correlates with involuntary emg in dystonia
    Neurology, 2006
    Co-Authors: C C Chen, Andrea A Kuhn, Karltitus Hoffmann, A Kupsch, Gerdhelge Schneider, T Trottenberg, Joachim K Krauss, Johannes C Wohrle, E Bardinet, Jerome Yelnik
    Abstract:

    The pathophysiology of dystonia is unclear. The authors recorded Local Field Potentials (LFPs) from deep brain stimulation electrodes implanted in the pallidum of 13 dystonic patients. LFP power correlated with the level of dystonic EMG in the sternocleidomastoid, with maximal positive correlations at the lower contacts of pallidal electrodes. The data suggest that the neuronal synchronization indexed by LFP oscillations in the globus pallidus may be mechanistically linked to dystonic EMG activity.