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Sample records for brain stimulation electrodes

  1. In vivo impedance spectroscopy of deep brain stimulation electrodes

    Science.gov (United States)

    Lempka, Scott F.; Miocinovic, Svjetlana; Johnson, Matthew D.; Vitek, Jerrold L.; McIntyre, Cameron C.

    2009-08-01

    Deep brain stimulation (DBS) represents a powerful clinical technology, but a systematic characterization of the electrical interactions between the electrode and the brain is lacking. The goal of this study was to examine the in vivo changes in the DBS electrode impedance that occur after implantation and during clinically relevant stimulation. Clinical DBS devices typically apply high-frequency voltage-controlled stimulation, and as a result, the injected current is directly regulated by the impedance of the electrode-tissue interface. We monitored the impedance of scaled-down clinical DBS electrodes implanted in the thalamus and subthalamic nucleus of a rhesus macaque using electrode impedance spectroscopy (EIS) measurements ranging from 0.5 Hz to 10 kHz. To further characterize our measurements, equivalent circuit models of the electrode-tissue interface were used to quantify the role of various interface components in producing the observed electrode impedance. Following implantation, the DBS electrode impedance increased and a semicircular arc was observed in the high-frequency range of the EIS measurements, commonly referred to as the tissue component of the impedance. Clinically relevant stimulation produced a rapid decrease in electrode impedance with extensive changes in the tissue component. These post-operative and stimulation-induced changes in impedance could play an important role in the observed functional effects of voltage-controlled DBS and should be considered during clinical stimulation parameter selection and chronic animal research studies.

  2. Modeling of a segmented electrode for desynchronizing deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Julia eBuhlmann

    2011-12-01

    Full Text Available Deep brain stimulation (DBS is an effective therapy for medically refrac- tory movement disorders like Parkinson’s disease. The electrodes, implanted in the target area within the human brain, generate an electric field which activates nerve fibers and cell bodies in the proximate vicinity. Even though the different target nuclei display considerable differences in their anatomical structure, only few types of electrodes are currently commercially available. It is desirable to adjust the electric field and in particular the volume of tissue activated around the electrode with respect to the corresponding target nucleus in a such way that side effects can be reduced. Furthermore, a more selective and partial activation of the target structure is desirable for an optimal application of novel stimulation strate- gies, e.g. coordinated reset neuromodulation. Hence we designed a DBS electrode with a segmented design allowing a more selective activation of the target struc- ture. We created a finite element model (FEM of the electrode and analyzed the volume of tissue activated for this electrode design. The segmented electrode ac- tivated an area in a targeted manner, of which the dimension and position relative to the electrode could be controlled by adjusting the stimulation parameters for each contact. According to our computational analysis, this directed stimulation might be superior with respect to the occurrence of side effects and it enables the application of coordinated reset neuromodulation under optimal conditions.

  3. A reliable method for intracranial electrode implantation and chronic electrical stimulation in the mouse brain

    OpenAIRE

    Jeffrey, Melanie; Lang, Min; Gane, Jonathan; Wu, Chiping; Burnham, W McIntyre; Zhang, Liang

    2013-01-01

    Background Electrical stimulation of brain structures has been widely used in rodent models for kindling or modeling deep brain stimulation used clinically. This requires surgical implantation of intracranial electrodes and subsequent chronic stimulation in individual animals for several weeks. Anchoring screws and dental acrylic have long been used to secure implanted intracranial electrodes in rats. However, such an approach is limited when carried out in mouse models as the thin mouse skul...

  4. Theoretical Optimization of Stimulation Strategies for a Directionally Segmented Deep Brain Stimulation Electrode Array.

    Science.gov (United States)

    Xiao, YiZi; Peña, Edgar; Johnson, Matthew D

    2016-02-01

    Programming deep brain stimulation (DBS) systems currently involves a clinician manually sweeping through a range of stimulus parameter settings to identify the setting that delivers the most robust therapy for a patient. With the advent of DBS arrays with a higher number and density of electrodes, this trial and error process becomes unmanageable in a clinical setting. This study developed a computationally efficient, model-based algorithm to estimate an electrode configuration that will most strongly activate tissue within a volume of interest. The cerebellar-receiving area of motor thalamus, the target for treating essential tremor with DBS, was rendered from imaging data and discretized into grid points aligned in approximate afferent and efferent axonal pathway orientations. A finite-element model (FEM) was constructed to simulate the volumetric tissue voltage during DBS. We leveraged the principle of voltage superposition to formulate a convex optimization-based approach to maximize activating function (AF) values at each grid point (via three different criteria), hence increasing the overall probability of action potential initiation and neuronal entrainment within the target volume. For both efferent and afferent pathways, this approach achieved global optima within several seconds. The optimal electrode configuration and resulting AF values differed across each optimization criteria and between axonal orientations. This approach only required a set of FEM simulations equal to the number of DBS array electrodes, and could readily accommodate anisotropic-inhomogeneous tissue conductances or other axonal orientations. The algorithm provides an efficient, flexible determination of optimal electrode configurations for programming DBS arrays. PMID:26208259

  5. Analysis of electrodes' placement and deformation in deep brain stimulation from medical images

    Science.gov (United States)

    Mehri, Maroua; Lalys, Florent; Maumet, Camille; Haegelen, Claire; Jannin, Pierre

    2012-02-01

    Deep brain stimulation (DBS) is used to reduce the motor symptoms such as rigidity or bradykinesia, in patients with Parkinson's disease (PD). The Subthalamic Nucleus (STN) has emerged as prime target of DBS in idiopathic PD. However, DBS surgery is a difficult procedure requiring the exact positioning of electrodes in the pre-operative selected targets. This positioning is usually planned using patients' pre-operative images, along with digital atlases, assuming that electrode's trajectory is linear. However, it has been demonstrated that anatomical brain deformations induce electrode's deformations resulting in errors in the intra-operative targeting stage. In order to meet the need of a higher degree of placement accuracy and to help constructing a computer-aided-placement tool, we studied the electrodes' deformation in regards to patients' clinical data (i.e., sex, mean PD duration and brain atrophy index). Firstly, we presented an automatic algorithm for the segmentation of electrode's axis from post-operative CT images, which aims to localize the electrodes' stimulated contacts. To assess our method, we applied our algorithm on 25 patients who had undergone bilateral STNDBS. We found a placement error of 0.91+/-0.38 mm. Then, from the segmented axis, we quantitatively analyzed the electrodes' curvature and correlated it with patients' clinical data. We found a positive significant correlation between mean curvature index of the electrode and brain atrophy index for male patients and between mean curvature index of the electrode and mean PD duration for female patients. These results help understanding DBS electrode' deformations and would help ensuring better anticipation of electrodes' placement.

  6. Analysis of electrodes' placement and deformation in deep brain stimulation from medical images

    OpenAIRE

    Mehri, Maroua; Lalys, Florent; Maumet, Camille; Haegelen, Claire; Jannin, Pierre

    2012-01-01

    Deep brain stimulation (DBS) is used to reduce the motor symptoms such as rigidity or bradykinesia in patients with Parkinson's disease (PD). The Subthalamic Nucleus (STN) has emerged as prime target of DBS in idiopathic PD. However, DBS surgery is a difficult procedure requiring the exact positioning of electrodes in the pre-operative selected targets. This positioning is usually planned using patients' pre-operative images, along with digital atlases, assuming that electrode's trajectory is...

  7. Design and in vivo evaluation of more efficient and selective deep brain stimulation electrodes

    Science.gov (United States)

    Howell, Bryan; Huynh, Brian; Grill, Warren M.

    2015-08-01

    Objective. Deep brain stimulation (DBS) is an effective treatment for movement disorders and a promising therapy for treating epilepsy and psychiatric disorders. Despite its clinical success, the efficiency and selectivity of DBS can be improved. Our objective was to design electrode geometries that increased the efficiency and selectivity of DBS. Approach. We coupled computational models of electrodes in brain tissue with cable models of axons of passage (AOPs), terminating axons (TAs), and local neurons (LNs); we used engineering optimization to design electrodes for stimulating these neural elements; and the model predictions were tested in vivo. Main results. Compared with the standard electrode used in the Medtronic Model 3387 and 3389 arrays, model-optimized electrodes consumed 45-84% less power. Similar gains in selectivity were evident with the optimized electrodes: 50% of parallel AOPs could be activated while reducing activation of perpendicular AOPs from 44 to 48% with the standard electrode to 0-14% with bipolar designs; 50% of perpendicular AOPs could be activated while reducing activation of parallel AOPs from 53 to 55% with the standard electrode to 1-5% with an array of cathodes; and, 50% of TAs could be activated while reducing activation of AOPs from 43 to 100% with the standard electrode to 2-15% with a distal anode. In vivo, both the geometry and polarity of the electrode had a profound impact on the efficiency and selectivity of stimulation. Significance. Model-based design is a powerful tool that can be used to improve the efficiency and selectivity of DBS electrodes.

  8. Fiber-based tissue identification for electrode placement in deep brain stimulation neurosurgery (Conference Presentation)

    Science.gov (United States)

    DePaoli, Damon T.; Lapointe, Nicolas; Goetz, Laurent; Parent, Martin; Prudhomme, Michel; Cantin, Léo.; Galstian, Tigran; Messaddeq, Younès.; Côté, Daniel C.

    2016-03-01

    Deep brain stimulation's effectiveness relies on the ability of the stimulating electrode to be properly placed within a specific target area of the brain. Optical guidance techniques that can increase the accuracy of the procedure, without causing any additional harm, are therefore of great interest. We have designed a cheap optical fiber-based device that is small enough to be placed within commercially available DBS stimulating electrodes' hollow cores and that is capable of sensing biological information from the surrounding tissue, using low power white light. With this probe we have shown the ability to distinguish white and grey matter as well as blood vessels, in vitro, in human brain samples and in vivo, in rats. We have also repeated the in vitro procedure with the probe inserted in a DBS stimulating electrode and found the results were in good agreement. We are currently validating a second fiber optic device, with micro-optical components, that will result in label free, molecular level sensing capabilities, using CARS spectroscopy. The final objective will be to use this data in real time, during deep brain stimulation neurosurgery, to increase the safety and accuracy of the procedure.

  9. Three-dimensional localization of cortical electrodes in deep brain stimulation surgery from intraoperative fluoroscopy.

    Science.gov (United States)

    Randazzo, Michael J; Kondylis, Efstathios D; Alhourani, Ahmad; Wozny, Thomas A; Lipski, Witold J; Crammond, Donald J; Richardson, R Mark

    2016-01-15

    Electrophysiological recordings from subdural electrocorticography (ECoG) electrodes implanted temporarily during deep brain stimulation (DBS) surgeries offer a unique opportunity to record cortical activity for research purposes. The optimal utilization of this important research method relies on accurate and robust localization of ECoG electrodes, and intraoperative fluoroscopy is often the only imaging modality available to visualize electrode locations. However, the localization of a three-dimensional electrode position using a two-dimensional fluoroscopic image is problematic due to the lost dimension orthogonal to the fluoroscopic image, a parallax distortion implicit to fluoroscopy, and variability of visible skull contour among fluoroscopic images. Here, we present a method to project electrodes visible on the fluoroscopic image onto a reconstructed cortical surface by leveraging numerous common landmarks to translate, rotate, and scale coregistered computed tomography (CT) and magnetic resonance imaging (MRI) reconstructed surfaces in order to recreate the coordinate framework in which the fluoroscopic image was acquired, while accounting for parallax distortion. Validation of this approach demonstrated high precision with an average total Euclidian distance between three independent reviewers of 1.65±0.68mm across 8 patients and 82 electrodes. Spatial accuracy was confirmed by correspondence between recorded neural activity over sensorimotor cortex during hand movement. This semi-automated interface reliably estimates the location of temporarily implanted subdural ECoG electrodes visible on intraoperative fluoroscopy to a cortical surface. PMID:26520771

  10. Double electrodes simultaneous stimulation and implantation technique in deep brain stimulation

    Institute of Scientific and Technical Information of China (English)

    BIAN Liu-guan; W Tirakotai; DK Schulte; H Bertalanffy; D Hellwig

    2005-01-01

    @@ Posttraumatic tremor is often one of the causes of disability in head injury patients. Usually, pharmacotherapy for this type of tremor is not effective. Since early 1970s, surgical ablation of the ventral thalamus has been used to treat various types of tremor.1 Nowadays, deep brain stimulation (DBS) confirms its efficacy in alleviating different forms of tremor, including posttraumatic tremor.2,3 Such therapy has been reported achieving around 80% success rate in the treatment of posttraumatic tremor.

  11. Modelling the current distribution across the depth electrode-brain interface in deep brain stimulation

    OpenAIRE

    Yousif, Nada; Liu, Xuguang

    2007-01-01

    The mismatch between the extensive clinical use of deep brain stimulation (DBS), which is being used to treat an increasing number of neurological disorders, and the lack of understanding of the underlying mechanisms, is confounded by the difficulty of measuring the spread of electric current in the brain in vivo. Here we present a brief review of the recent computational models which simulate the electric current and field distribution in the three-dimensional space, and consequently make es...

  12. Evaluation of electrode position in deep brain stimulation by image fusion (MRI and CT)

    International Nuclear Information System (INIS)

    Imaging has an essential role in the evaluation of correct positioning of electrodes implanted for deep brain stimulation (DBS). Although MRI offers superior anatomic visualization of target sites, there are safety concerns in patients with implanted material; imaging guidelines are inconsistent and vary. The fusion of postoperative CT with preoperative MRI images can be an alternative for the assessment of electrode positioning. The purpose of this study was to assess the accuracy of measurements realized on fused images (acquired without a stereotactic frame) using a manufacturer-provided software. Data from 23 Parkinson's disease patients who underwent bilateral electrode placement for subthalamic nucleus (STN) DBS were acquired. Preoperative high-resolution T2-weighted sequences at 3 T, and postoperative CT series were fused using a commercially available software. Electrode tip position was measured on the obtained images in three directions (in relation to the midline, the AC-PC line and an AC-PC line orthogonal, respectively) and assessed in relation to measures realized on postoperative 3D T1 images acquired at 1.5 T. Mean differences between measures carried out on fused images and on postoperative MRI lay between 0.17 and 0.97 mm. Fusion of CT and MRI images provides a safe and fast technique for postoperative assessment of electrode position in DBS. (orig.)

  13. Evaluation of electrode position in deep brain stimulation by image fusion (MRI and CT)

    Energy Technology Data Exchange (ETDEWEB)

    Barnaure, I.; Lovblad, K.O.; Vargas, M.I. [Geneva University Hospital, Department of Neuroradiology, Geneva 14 (Switzerland); Pollak, P.; Horvath, J.; Boex, C.; Burkhard, P. [Geneva University Hospital, Department of Neurology, Geneva (Switzerland); Momjian, S. [Geneva University Hospital, Department of Neurosurgery, Geneva (Switzerland); Remuinan, J. [Geneva University Hospital, Department of Radiology, Geneva (Switzerland)

    2015-09-15

    Imaging has an essential role in the evaluation of correct positioning of electrodes implanted for deep brain stimulation (DBS). Although MRI offers superior anatomic visualization of target sites, there are safety concerns in patients with implanted material; imaging guidelines are inconsistent and vary. The fusion of postoperative CT with preoperative MRI images can be an alternative for the assessment of electrode positioning. The purpose of this study was to assess the accuracy of measurements realized on fused images (acquired without a stereotactic frame) using a manufacturer-provided software. Data from 23 Parkinson's disease patients who underwent bilateral electrode placement for subthalamic nucleus (STN) DBS were acquired. Preoperative high-resolution T2-weighted sequences at 3 T, and postoperative CT series were fused using a commercially available software. Electrode tip position was measured on the obtained images in three directions (in relation to the midline, the AC-PC line and an AC-PC line orthogonal, respectively) and assessed in relation to measures realized on postoperative 3D T1 images acquired at 1.5 T. Mean differences between measures carried out on fused images and on postoperative MRI lay between 0.17 and 0.97 mm. Fusion of CT and MRI images provides a safe and fast technique for postoperative assessment of electrode position in DBS. (orig.)

  14. Investigating the depth electrode-brain interface in deep brain stimulation using finite element models with graded complexity in structure and solution

    OpenAIRE

    Yousif, Nada; Liu, Xuguang

    2009-01-01

    Deep brain stimulation (DBS) is an increasingly used surgical therapy for a range of neurological disorders involving the long-term electrical stimulation of various regions of the human brain in a disorder-specific manner. Despite being used for the last 20 years, the underlying mechanisms are still not known, and disputed. In particular, when the electrodes are implanted into the human brain, an interface is created with changing biophysical properties which may impact on stimulation. We pr...

  15. Ir-Ni oxide as a promising material for nerve and brain stimulating electrodes

    Directory of Open Access Journals (Sweden)

    Joan Stilling

    2014-09-01

    Full Text Available Tremendous potential for successful medical device development lies in both electrical stimulation therapies and neuronal prosthetic devices, which can be utilized in an extensive number of neurological disorders. These technologies rely on the successful electrical stimulation of biological tissue (i.e. neurons through the use of electrodes. However, this technology faces the principal problem of poor stimulus selectivity due to the currently available electrode’s large size relative to its targeted population of neurons. Irreversible damage to both the stimulated tissue and electrode are limiting factors in miniaturization of this technology, as charge density increases with decreasing electrode size. In an attempt to find an equilibrium between these two opposing constraints (electrode size and charge density, the objective of this work was to develop a novel iridium-nickel oxide (Ir0.2-Ni0.8-oxide coating that could intrinsically offer high charge storage capacity. Thermal decomposition was used to fabricate titanium oxide, iridium oxide, nickel oxide, and bimetallic iridium-nickel oxide coatings on titanium electrode substrates. The Ir0.2-Ni0.8-oxide coating yielded the highest intrinsic (material property and extrinsic (material property + surface area charge storage capacity (CSC among the investigated materials, exceeding the performance of the current state-of-the-art neural stimulating electrode, Ir-oxide. This indicates that the Ir0.2-Ni0.8-oxide material is a promising alternative to currently used Ir-oxide, Pt, Au and carbon-based stimulating electrodes.

  16. Direct-current Stimulation and Multi-electrode Array Recording of Seizure-like Activity in Mice Brain Slice Preparation.

    Science.gov (United States)

    Lu, Hsiang-Chin; Chang, Wei-Jen; Chang, Wei-Pang; Shyu, Bai-Chuang

    2016-01-01

    Cathodal transcranial direct-current stimulation (tDCS) induces suppressive effects on drug-resistant seizures. To perform effective actions, the stimulation parameters (e.g., orientation, field strength, and stimulation duration) need to be examined in mice brain slice preparations. Testing and arranging the orientation of the electrode relative to the position of the mice brain slice are feasible. The present method preserves the thalamocingulate pathway to evaluate the effect of DCS on anterior cingulate cortex seizure-like activities. The results of the multichannel array recordings indicated that cathodal DCS significantly decreased the amplitude of the stimulation-evoked responses and duration of 4-aminopyridine and bicuculline-induced seizure-like activity. This study also found that cathodal DCS applications at 15 min caused long-term depression in the thalamocingulate pathway. The present study investigates the effects of DCS on thalamocingulate synaptic plasticity and acute seizure-like activities. The current procedure can test the optimal stimulation parameters including orientation, field strength, and stimulation duration in an in vitro mouse model. Also, the method can evaluate the effects of DCS on cortical seizure-like activities at both the cellular and network levels. PMID:27341682

  17. Heating induced near deep brain stimulation lead electrodes during magnetic resonance imaging with a 3 T transceive volume head coil

    International Nuclear Information System (INIS)

    Heating induced near deep brain stimulation (DBS) lead electrodes during magnetic resonance imaging with a 3 T transceive head coil was measured, modeled, and imaged in three cadaveric porcine heads (mean body weight = 85.47 ± 3.19 kg, mean head weight = 5.78 ± 0.32 kg). The effect of the placement of the extra-cranial portion of the DBS lead on the heating was investigated by looping the extra-cranial lead on the top, side, and back of the head, and placing it parallel to the coil's longitudinal axial direction. The heating was induced using a 641 s long turbo spin echo sequence with the mean whole head average specific absorption rate of 3.16 W kg−1. Temperatures were measured using fluoroptic probes at the scalp, first and second electrodes from the distal lead tip, and 6 mm distal from electrode 1 (T6mm). The heating was modeled using the maximum T6mm and imaged using a proton resonance frequency shift-based MR thermometry method. Results showed that the heating was significantly reduced when the extra-cranial lead was placed in the longitudinal direction compared to the other placements (peak temperature change = 1.5–3.2 °C versus 5.1–24.7 °C). Thermal modeling and MR thermometry may be used together to determine the heating and improve patient safety online. (paper)

  18. Model-Based Comparison of Deep Brain Stimulation Array Functionality with Varying Number of Radial Electrodes and Machine Learning Feature Sets.

    Science.gov (United States)

    Teplitzky, Benjamin A; Zitella, Laura M; Xiao, YiZi; Johnson, Matthew D

    2016-01-01

    Deep brain stimulation (DBS) leads with radially distributed electrodes have potential to improve clinical outcomes through more selective targeting of pathways and networks within the brain. However, increasing the number of electrodes on clinical DBS leads by replacing conventional cylindrical shell electrodes with radially distributed electrodes raises practical design and stimulation programming challenges. We used computational modeling to investigate: (1) how the number of radial electrodes impact the ability to steer, shift, and sculpt a region of neural activation (RoA), and (2) which RoA features are best used in combination with machine learning classifiers to predict programming settings to target a particular area near the lead. Stimulation configurations were modeled using 27 lead designs with one to nine radially distributed electrodes. The computational modeling framework consisted of a three-dimensional finite element tissue conductance model in combination with a multi-compartment biophysical axon model. For each lead design, two-dimensional threshold-dependent RoAs were calculated from the computational modeling results. The models showed more radial electrodes enabled finer resolution RoA steering; however, stimulation amplitude, and therefore spatial extent of the RoA, was limited by charge injection and charge storage capacity constraints due to the small electrode surface area for leads with more than four radially distributed electrodes. RoA shifting resolution was improved by the addition of radial electrodes when using uniform multi-cathode stimulation, but non-uniform multi-cathode stimulation produced equivalent or better resolution shifting without increasing the number of radial electrodes. Robust machine learning classification of 15 monopolar stimulation configurations was achieved using as few as three geometric features describing a RoA. The results of this study indicate that, for a clinical-scale DBS lead, more than four radial

  19. Anticipation of Brain Shift in Deep Brain Stimulation Automatic Planning

    OpenAIRE

    Hamzé, Noura; Bilger, Alexandre; Duriez, Christian; Cotin, Stéphane; Essert, Caroline

    2015-01-01

    International audience Deep Brain Stimulation is a neurosurgery procedure consisting in implanting an electrode in a deep structure of the brain. This intervention requires a preoperative planning phase, with a millimetric accuracy, in which surgeons decide the best placement of the electrode depending on a set of surgical rules. However, brain tissues may deform during the surgery because of the brain shift phenomenon, leading the electrode to mistake the target, or moreover to damage a v...

  20. Electrode array for neural stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Wessendorf, Kurt O. (Albuquerque, NM); Okandan, Murat (Edgewood, NM); Stein, David J. (Albuquerque, NM); Yang, Pin (Albuquerque, NM); Cesarano, III, Joseph (Albuquerque, NM); Dellinger, Jennifer (Albuquerque, NM)

    2011-08-16

    An electrode array for neural stimulation is disclosed which has particular applications for use in a retinal prosthesis. The electrode array can be formed as a hermetically-sealed two-part ceramic package which includes an electronic circuit such as a demultiplexer circuit encapsulated therein. A relatively large number (up to 1000 or more) of individually-addressable electrodes are provided on a curved surface of a ceramic base portion the electrode array, while a much smaller number of electrical connections are provided on a ceramic lid of the electrode array. The base and lid can be attached using a metal-to-metal seal formed by laser brazing. Electrical connections to the electrode array can be provided by a flexible ribbon cable which can also be used to secure the electrode array in place.

  1. ''Sukeroku sign'' and ''dent internal-capsule sign'' - identification guide for targeting the subthalamic nucleus for placement of deep brain stimulation electrodes

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the usefulness of signs (''Sukeroku sign'' and ''dent internal-capsule sign'') for the recognition of subthalamic nucleus (STN). Five Parkinson's disease cases in which there was a successful placement of deep brain stimulation (DBS) electrodes at the STN were retrospectively reviewed. Five radiologists who were not engaged in localization of STNs in clinical practice were asked to locate the STNs before and after instructions on the signs. We evaluated the deviation between the reader-located points and the location of the DBS electrode for which there had been a successful installation. After instruction, there was a significant reduction in the deviation between the reader-located points and the DBS electrode. The time required for localization was also reduced after the instructions. Sukeroku sign and dent internal-capsule sign are feasible indicators of STN and seem to be useful in helping to identify the STN. (orig.)

  2. Deep brain stimulation: new techniques.

    Science.gov (United States)

    Hariz, Marwan

    2014-01-01

    The technology of the hardware used in deep brain stimulation (DBS), and the mode of delivering the stimulation have not significantly evolved since the start of the modern era of DBS 25 years ago. However, new technology is now being developed along several avenues. New features of the implantable pulse generator (IPG) allow fractionation of the electric current into variable proportions between different contacts of the multi-polar lead. Another design consists in leads that allow selective current steering from directionally placed electrode contacts that would deliver the stimulation in a specific direction or even create a directional shaped electric field that would conform to the anatomy of the brain target aimed at, avoiding adjacent structures, and thus avoiding side effects. Closed loop adaptive stimulation technologies are being developed, allowing a tracking of the pathological local field potential of the brain target, and delivering automatically the stimulation to suppress the pathological activity as soon as it is detected and for as long as needed. This feature may contribute to a DBS therapy "on demand", instead of continuously. Finally, advances in imaging technology are providing "new" brain targets, and increasingly allowing DBS to be performed accurately while avoiding the risks of microelectrode recording. PMID:24262179

  3. Deep Brain Stimulation

    OpenAIRE

    Perlmutter, Joel. S.; Mink, Jonathan W.

    2006-01-01

    Deep brain stimulation (DBS) has provided remarkable benefits for people with a variety of neurologic conditions. Stimulation of the ventral intermediate nucleus of the thalamus can dramatically relieve tremor associated with essential tremor or Parkinson disease (PD). Similarly, stimulation of the subthalamic nucleus or the internal segment of the globus pallidus can substantially reduce bradykinesia, rigidity, tremor, and gait difficulties in people with PD. Multiple groups are attempting t...

  4. Novel fingerprinting method characterises the necessary and sufficient structural connectivity from deep brain stimulation electrodes for a successful outcome

    Science.gov (United States)

    Fernandes, Henrique M.; Van Hartevelt, Tim J.; Boccard, Sandra G. J.; Owen, Sarah L. F.; Cabral, Joana; Deco, Gustavo; Green, Alex L.; Fitzgerald, James J.; Aziz, Tipu Z.; Kringelbach, Morten L.

    2015-01-01

    Deep brain stimulation (DBS) is a remarkably effective clinical tool, used primarily for movement disorders. DBS relies on precise targeting of specific brain regions to rebalance the oscillatory behaviour of whole-brain neural networks. Traditionally, DBS targeting has been based upon animal models (such as MPTP for Parkinson’s disease) but has also been the result of serendipity during human lesional neurosurgery. There are, however, no good animal models of psychiatric disorders such as depression and schizophrenia, and progress in this area has been slow. In this paper, we use advanced tractography combined with whole-brain anatomical parcellation to provide a rational foundation for identifying the connectivity ‘fingerprint’ of existing, successful DBS targets. This knowledge can then be used pre-surgically and even potentially for the discovery of novel targets. First, using data from our recent case series of cingulate DBS for patients with treatment-resistant chronic pain, we demonstrate how to identify the structural ‘fingerprints’ of existing successful and unsuccessful DBS targets in terms of their connectivity to other brain regions, as defined by the whole-brain anatomical parcellation. Second, we use a number of different strategies to identify the successful fingerprints of structural connectivity across four patients with successful outcomes compared with two patients with unsuccessful outcomes. This fingerprinting method can potentially be used pre-surgically to account for a patient’s individual connectivity and identify the best DBS target. Ultimately, our novel fingerprinting method could be combined with advanced whole-brain computational modelling of the spontaneous dynamics arising from the structural changes in disease, to provide new insights and potentially new targets for hitherto impenetrable neuropsychiatric disorders.

  5. NONINVASIVE BRAIN STIMULATION IN TRAUMATIC BRAIN INJURY

    OpenAIRE

    Demirtas-Tatlidede, Asli; Vahabzadeh-Hagh, Andrew M.; Bernabeu, Montserrat; Tormos, Jose M.; Pascual-Leone, Alvaro

    2012-01-01

    Brain stimulation techniques have evolved in the last few decades with more novel methods capable of painless, noninvasive brain stimulation. While the number of clinical trials employing noninvasive brain stimulation continues to increase in a variety of medication-resistant neurological and psychiatric diseases, studies evaluating their diagnostic and therapeutic potential in traumatic brain injury (TBI) are largely lacking. This review introduces different techniques of noninvasive brain s...

  6. Electrodes for bio-application: recording and stimulation

    Science.gov (United States)

    Fontes, M. B. A.

    2013-03-01

    Recording and stimulation electrodes applied on excitable tissue are the basis of electrophysiological research, such as brain, muscles, peripheral nerves or sensory systems. Electrode-electrolyte impedance is one of the important characteristics due to its influence on the signal/noise ratio, signal distortion and built-up voltage. Strategies to lowering and tuning the impedance are achieved by biasing iridium oxide modified platinum microelectrodes. Surface and impedance analysis after pulse stimulation are also addressed.

  7. Transcranial brain stimulation: closing the loop between brain and stimulation

    DEFF Research Database (Denmark)

    Karabanov, Anke; Thielscher, Axel; Siebner, Hartwig Roman

    2016-01-01

    PURPOSE OF REVIEW: To discuss recent strategies for boosting the efficacy of noninvasive transcranial brain stimulation to improve human brain function. RECENT FINDINGS: Recent research exposed substantial intra- and inter-individual variability in response to plasticity-inducing transcranial brain...... transcranial brain stimulation. Priming interventions or paired associative stimulation can be used to ‘standardize’ the brain-state and hereby, homogenize the group response to stimulation. Neuroanatomical and neurochemical profiling based on magnetic resonance imaging and spectroscopy can capture trait......-related and state-related variability. Fluctuations in brain-states can be traced online with functional brain imaging and inform the timing or other settings of transcranial brain stimulation. State-informed open-loop stimulation is aligned to the expression of a predefined brain state, according to prespecified...

  8. Graphene electrodes for stimulation of neuronal cells

    Science.gov (United States)

    Koerbitzer, Berit; Krauss, Peter; Nick, Christoph; Yadav, Sandeep; Schneider, Joerg J.; Thielemann, Christiane

    2016-06-01

    Graphene has the ability to improve the electrical interface between neuronal cells and electrodes used for recording and stimulation purposes. It provides a biocompatible coating for common electrode materials such as gold and improves the electrode properties. Graphene electrodes are also prepared on SiO2 substrate to benefit from its optical properties like transparency. We perform electrochemical and Raman characterization of gold electrodes with graphene coating and compare them with graphene on SiO2 substrate. It was found that the substrate plays an important role in the performance of graphene and show that graphene on SiO2 substrate is a very promising material combination for stimulation electrodes.

  9. Stimulation and recording electrodes for neural prostheses

    CERN Document Server

    Pour Aryan, Naser; Rothermel, Albrecht

    2015-01-01

    This book provides readers with basic principles of the electrochemistry of the electrodes used in modern, implantable neural prostheses. The authors discuss the boundaries and conditions in which the electrodes continue to function properly for long time spans, which are required when designing neural stimulator devices for long-term in vivo applications. Two kinds of electrode materials, titanium nitride and iridium are discussed extensively, both qualitatively and quantitatively. The influence of the counter electrode on the safety margins and electrode lifetime in a two electrode system is explained. Electrode modeling is handled in a final chapter.

  10. Neuroprotection trek--the next generation: neuromodulation I. Techniques--deep brain stimulation, vagus nerve stimulation, and transcranial magnetic stimulation

    Science.gov (United States)

    Andrews, Russell J.

    2003-01-01

    Neuromodulation denotes controlled electrical stimulation of the central or peripheral nervous system. The three forms of neuromodulation described in this paper-deep brain stimulation, vagus nerve stimulation, and transcranial magnetic stimulation-were chosen primarily for their demonstrated or potential clinical usefulness. Deep brain stimulation is a completely implanted technique for improving movement disorders, such as Parkinson's disease, by very focal electrical stimulation of the brain-a technique that employs well-established hardware (electrode and pulse generator/battery). Vagus nerve stimulation is similar to deep brain stimulation in being well-established (for the treatment of refractory epilepsy), completely implanted, and having hardware that can be considered standard at the present time. Vagus nerve stimulation differs from deep brain stimulation, however, in that afferent stimulation of the vagus nerve results in diffuse effects on many regions throughout the brain. Although use of deep brain stimulation for applications beyond movement disorders will no doubt involve placing the stimulating electrode(s) in regions other than the thalamus, subthalamus, or globus pallidus, the use of vagus nerve stimulation for applications beyond epilepsy-for example, depression and eating disorders-is unlikely to require altering the hardware significantly (although stimulation protocols may differ). Transcranial magnetic stimulation is an example of an external or non-implanted, intermittent (at least given the current state of the hardware) stimulation technique, the clinical value of which for neuromodulation and neuroprotection remains to be determined.

  11. Accuracy and safety of targeting using intraoperative "O-arm" during placement of deep brain stimulation electrodes without electrophysiological recordings.

    Science.gov (United States)

    Sharma, Mayur; Deogaonkar, Milind

    2016-05-01

    The aim of our study was to investigate the accuracy of targeting using intraoperative "O-arm" during deep brain stimulation (DBS) surgery. Intraoperative O-arm (Medtronic, Minneapolis, MN, USA) images were obtained to confirm the accuracy of placement. The difference between intended and actual target coordinates was calculated based on intraoperative images and postoperative CT scan. Euclidian vector error was obtained to estimate the directional error. Correlation of targeting error with the pneumocephalus and the deviation from the planned trajectory was also estimated. Twenty eight DBS leads (globus pallidus internus [GPi], n=13; subthalamic nucleus [STN], n=9; ventralis intermedius nucleus [VIM], n=6) were implanted in 20 patients using the stereotactic Leksell frame (Elekta AB, Stockholm, Sweden) under general anesthesia over a period of 1year. The mean age was 63.6±standard error of the mean (SEM) 15.7years and 60% of patients were males. The mean absolute difference (+SEM) between intended and actual target in x, y and z coordinates based on intraoperative CT scan was 0.65±0.09 (p=0.84), 0.58±0.08 (p=0.98), 1.13±0.10 (p=0.08), respectively, and postoperative (1month) CT scan was 0.82±0.15 (p=0.89), 0.55±0.11 (p=0.97), and 1.58±0.29 (p=0.08), respectively. The Euclidean vector error was 1.59±0.10 and 2.16±0.26 based on intraoperative and postoperative images, respectively. There was no statistically significant targeting error based on fusion of intraoperative CT images to either preoperative CT scan or MRI as registration series, the presence of pneumocephalus, deviation from planned trajectory or the anatomical target (STN versus VIM versus GPi) (p>0.05). Superficial skin infection was encountered in a single patient in this study. The mean total operating room time was 193.5±74.6 minutes. None of the patients required revision in our study. DBS leads can be implanted safely and accurately using intraoperative O-arm with a frame based targeting

  12. A retrofitted neural recording system with a novel stimulation IC to monitor early neural responses from a stimulating electrode

    OpenAIRE

    Nam, Yoonkey; Brown, Edgar A.; Ross, James D. (Dalhousie University); Blum, Richard A.; Wheeler, Bruce C.; DeWeerth, Stephen P.

    2008-01-01

    Extracellular electrical stimulation is increasingly used for in vitro neural experimentation, including brain slices and cultured cells. Although it is desirable to record directly from the stimulating electrode, relatively high stimulation levels make it extremely difficult to record immediately after the stimulation. We have shown that this is feasible by a stimulation system (analog IC) that includes the feature of active electrode discharge. Here, we piggybacked the new IC onto an existi...

  13. Electrodes for transcutaneous (surface) electrical stimulation

    OpenAIRE

    Keller Thierry; Kuhn Andreas

    2008-01-01

    In therapeutic and functional applications transcutaneous electrical stimulation (TES) is still the most frequently applied technique for muscle and nerve activation despite the huge efforts made to improve implantable technologies. Stimulation electrodes play the important role in interfacing the tissue with the stimulation unit. Between the electrode and the excitable tissue there are a number of obstacles in form of tissue resistivities and permittivities that can only be circumvented by m...

  14. Deep Brain Stimulation for Parkinson's Disease

    Science.gov (United States)

    ... Enhancing Diversity Find People About NINDS NINDS Deep Brain Stimulation for Parkinson's Disease Information Page Condensed from ... and Information Publicaciones en Español What is Deep Brain Stimulation for Parkinson's Disease? Deep brain stimulation (DBS) ...

  15. Moving the brain: Neuroimaging motivational changes of deep brain stimulation in obsessive-compulsive disorder

    NARCIS (Netherlands)

    M. Figee

    2013-01-01

    Deep brain stimulation (DBS) is a neurosurgical technique that involves the implantation of electrodes in the brain. DBS enables electrical modulation of abnormal brain activity for treatment of neuropsychiatric disorders such as obsessive-compulsive disorder (OCD). Mrs. D. has been suffering from O

  16. Electrodes for transcutaneous (surface electrical stimulation

    Directory of Open Access Journals (Sweden)

    Keller Thierry

    2008-01-01

    Full Text Available In therapeutic and functional applications transcutaneous electrical stimulation (TES is still the most frequently applied technique for muscle and nerve activation despite the huge efforts made to improve implantable technologies. Stimulation electrodes play the important role in interfacing the tissue with the stimulation unit. Between the electrode and the excitable tissue there are a number of obstacles in form of tissue resistivities and permittivities that can only be circumvented by magnetic fields but not by electric fields and currents. However, the generation of magnetic fields needed for the activation of excitable tissues in the human body requires large and bulky equipment. TES devices on the other hand can be built cheap, small and light weight. The weak part in TES is the electrode that cannot be brought close enough to the excitable tissue and has to fulfill a number of requirements to be able to act as efficient as possible. The present review article summarizes the most important factors that influence efficient TES, presents and discusses currently used electrode materials, designs and configurations, and points out findings that have been obtained through modeling, simulation and testing.

  17. Brain-shift aware risk map for Deep Brain Stimulation Planning

    OpenAIRE

    Bilger, Alexandre; Essert, Caroline; Duriez, Christian; Cotin, Stéphane

    2012-01-01

    In Deep Brain Stimulation surgery, the efficiency of the procedure heavily relies on the accuracy of the placement of the stimulating electrode. Meanwhile, the effectiveness of the placement is difficult due to brain shifts occurring during and after the procedure. We propose an approach to overcome the limitations of current planning software that ignores brain shift. In particular, we consider the motion of vascular structures in order to reduce risks of dissecting a vessel during the proce...

  18. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

    OpenAIRE

    Hui Zhou; Yi Lu; Wanzhen Chen; Zhen Wu; Haiqing Zou; Ludovic Krundel; Guanglin Li

    2015-01-01

    Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel ele...

  19. Deep brain stimulation in psychiatry

    Directory of Open Access Journals (Sweden)

    Poznić-Ješić Milana

    2014-01-01

    Full Text Available Introduction. Deep brain stimulation is a stereotactic neurosurgical method used in the treatment of Parkinson’s disease and some other movement disorders. The application of deep brain stimulation in the treatment of certain psychiatric disorders has been intensively investigated taking into account the current knowledge of neurobiological basis of mood regulation, cognition, and behaviour. This paper has been aimed at presenting the available data on experience in the application of deep brain stimulation in the treatment of psychiatric disorders. It gives an overview of scientific and professional literature, bearing in mind all the contemporary approaches in the treatment of certain psychiatric disorders. Research results available so far in the treatment of treatment-resistant depression, obsessive-compulsive disorder, Gilles de la Tourette syndrome, addiction and Alzheimer’s dementia, are affirmative concerning the efficacy of the method and low risk of adverse effects. Deep brain stimulation, as a relatively new neurosurgical method in the treatment of psychiatric disorders, is being intensively developed, and it is certainly going to be one of the treatments of choice, primarily of treatment-resistant disorders.

  20. Deep brain stimulation increases impulsivity in two patients with obsessive-compulsive disorder

    NARCIS (Netherlands)

    J. Luigjes; M. Mantione; W. van den Brink; P.R. Schuurman; P. van den Munckhof; D. Denys

    2011-01-01

    Deep brain stimulation (DBS) is an adjustable, reversible, nondestructive neurosurgical intervention using implanted electrodes to deliver electrical pulses to areas in the brain. DBS has recently shown promising results as an experimental treatment of refractory obsessive-compulsive disorder (OCD).

  1. Deep Brain Stimulation Tested for Early Alzheimer's

    Science.gov (United States)

    ... 160137.html Deep Brain Stimulation Tested for Early Alzheimer's Although treatment seems safe, benefit isn't yet ... brain stimulation appears safe for people with early Alzheimer's disease -- and might even slow down memory loss ...

  2. Deep brain stimulation: Current status

    Directory of Open Access Journals (Sweden)

    Sanjay Pandey

    2015-01-01

    Full Text Available In the last two decades, applications of deep brain stimulation (DBS have expanded rapidly in the field of neurosciences. The most common indications for DBS are Parkinson′s disease, medically refractory seizures, essential tremors, and primary dystonia. This device has also been used as an investigational tool in patients having Tourette′s syndrome, tardive dyskinesia, and refractory seizures. In the field of psychiatry, DBS has been used for the treatment of refractory obsessive compulsive disorder and depression. The complications are mainly related to surgery, the device, and its stimulation. This article provides an overview of the current status and recent advances in the field of DBS.

  3. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Hui Zhou

    2015-07-01

    Full Text Available Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes.

  4. MRI-induced heating of deep brain stimulation leads

    International Nuclear Information System (INIS)

    The radiofrequency (RF) field used in magnetic resonance imaging is scattered by medical implants. The scattered field of a deep brain stimulation lead can be very intense near the electrodes stimulating the brain. The effect is more pronounced if the lead behaves as a resonant antenna. In this paper, we examine the resonant length effect. We also use the finite element method to compute the near field for (i) the lead immersed in inhomogeneous tissue (fat, muscle, and brain tissues) and (ii) the lead connected to an implantable pulse generator. Electric field, specific absorption rate and induced temperature rise distributions have been obtained in the brain tissue surrounding the electrodes. The worst-case scenario has been evaluated by neglecting the effect of blood perfusion. The computed values are in good agreement with in vitro measurements made in the laboratory.

  5. Moving the brain: Neuroimaging motivational changes of deep brain stimulation in obsessive-compulsive disorder

    OpenAIRE

    Denys, D.A.J.P.; Wingen, van, G.A.; Figee, M

    2013-01-01

    Deep brain stimulation (DBS) is a neurosurgical technique that involves the implantation of electrodes in the brain. DBS enables electrical modulation of abnormal brain activity for treatment of neuropsychiatric disorders such as obsessive-compulsive disorder (OCD). Mrs. D. has been suffering from OCD for more than 20 years, which caused her to compulsively clean every detail of her house and have obsessive thoughts about dirt and contamination. DBS helped her to overcome all of her obsession...

  6. Deep brain stimulation for chronic pain.

    Science.gov (United States)

    Boccard, Sandra G J; Pereira, Erlick A C; Aziz, Tipu Z

    2015-10-01

    Deep brain stimulation (DBS) is a neurosurgical intervention popularised in movement disorders such as Parkinson's disease, and also reported to improve symptoms of epilepsy, Tourette's syndrome, obsessive compulsive disorders and cluster headache. Since the 1950s, DBS has been used as a treatment to relieve intractable pain of several aetiologies including post stroke pain, phantom limb pain, facial pain and brachial plexus avulsion. Several patient series have shown benefits in stimulating various brain areas, including the sensory thalamus (ventral posterior lateral and medial), the periaqueductal and periventricular grey, or, more recently, the anterior cingulate cortex. However, this technique remains "off label" in the USA as it does not have Federal Drug Administration approval. Consequently, only a small number of surgeons report DBS for pain using current technology and techniques and few regions approve it. Randomised, blinded and controlled clinical trials that may use novel trial methodologies are desirable to evaluate the efficacy of DBS in patients who are refractory to other therapies. New imaging techniques, including tractography, may help optimise electrode placement and clinical outcome. PMID:26122383

  7. Computer Controlled Switching Device for Deep Brain Stimulation

    Directory of Open Access Journals (Sweden)

    J. Tauchmanová

    2007-01-01

    Full Text Available This paper has two goals. The practical part deals with the design of a computer controlled switching device for an external stimulator for deep brain stimulation. The switching device is used during investigations with functional magnetic resonance for controlling signals leading to the deep brain stimulation (DBS electrode in the patient's brain. The motivation for designing this device was improve measured data quality and to enable new types of experiments.The theoretical part reports on early attempts to approach the problem of modeling and localizing the neural response of the human brain as a system identification and estimation task. The parametric identification method and real fMRI data are used for modeling the hemodynamic response.The project is in cooperation with 1st Faculty of Medicine, Charles University in Prague and Na Homolce hospital in Prague.

  8. Carbon Nanofiber Nanoelectrodes for Neural Stimulation and Chemical Detection: The Era of Smart Deep Brain Stimulation

    Science.gov (United States)

    Koehne, Jessica E.

    2016-01-01

    A sensor platform based on vertically aligned carbon nanofibers (CNFs) has been developed. Their inherent nanometer scale, high conductivity, wide potential window, good biocompatibility and well-defined surface chemistry make them ideal candidates as biosensor electrodes. Here, we report two studies using vertically aligned CNF nanoelectrodes for biomedical applications. CNF arrays are investigated as neural stimulation and neurotransmitter recording electrodes for application in deep brain stimulation (DBS). Polypyrrole coated CNF nanoelectrodes have shown great promise as stimulating electrodes due to their large surface area, low impedance, biocompatibility and capacity for highly localized stimulation. CNFs embedded in SiO2 have been used as sensing electrodes for neurotransmitter detection. Our approach combines a multiplexed CNF electrode chip, developed at NASA Ames Research Center, with the Wireless Instantaneous Neurotransmitter Concentration Sensor (WINCS) system, developed at the Mayo Clinic. Preliminary results indicate that the CNF nanoelectrode arrays are easily integrated with WINCS for neurotransmitter detection in a multiplexed array format. In the future, combining CNF based stimulating and recording electrodes with WINCS may lay the foundation for an implantable "smart" therapeutic system that utilizes neurochemical feedback control while likely resulting in increased DBS application in various neuropsychiatric disorders. In total, our goal is to take advantage of the nanostructure of CNF arrays for biosensing studies requiring ultrahigh sensitivity, high-degree of miniaturization, and selective biofunctionalization.

  9. Deep brain stimulation: new directions.

    Science.gov (United States)

    Ostergard, T; Miller, J P

    2014-12-01

    The role of deep brain stimulation (DBS) in the treatment of movement disorders is well established, but there has recently been a proliferation of additional indications that have been shown to be amenable to this technology. The combination of innovative approaches to neural interface technology with novel target identification based on previously discovered clinical effects of lesioning procedures has led to a fundamental paradigm for new directions in the application of DBS. The historical use of neurosurgical lesioning procedures in the treatment of psychiatric diseases such as obsessive compulsive disorder provided an initial opportunity to expand the use of DBS. The list is rapidly expanding and now includes major depressive disorder, Tourette's syndrome, addiction disorders, and eating disorders. Keen observations by neurosurgeons using these devices have lead to the incidental discovery of treatments for diseases without previous neurosurgical treatments. These discoveries are breaking new ground in the treatment of disorders of cognition, headache syndromes, disorders of consciousness, and epilepsy. Two features of DBS make it well-suited for treatment of disorders of nervous system function. First, the reversible, non-lesional nature of DBS allows for investigation of new targets without the morbidity of permanent side effects. Second, the programmable nature of DBS allows practitioners to alter stimulation patterns to minimize side effects and potentially improve efficacy through reprogramming. More importantly, proper scientific evaluation of new targets is aided by the ability to turn stimulation on and off with evaluators blinded to the stimulation status. Knowledge of these emerging therapies is important for practitioners, as there are many situations where a single target can effectively treat the symptoms of more than one disease. The intersection of advances in neuromodulation, neurophysiology, neuroimaging, and functional neuroanatomy has

  10. Brain stimulation and inhibitory control.

    Science.gov (United States)

    Juan, Chi-Hung; Muggleton, Neil G

    2012-04-01

    Inhibitory control mechanisms are important in a range of behaviours to prevent execution of motor acts which, having been planned, are no longer necessary or appropriate. Examples of this can be seen in a range of sports, such as cricket and baseball, where the choice between execution and inhibition of a bat swing must be made in a very brief time window. Deficits in inhibitory control have been associated with problems in behavioural regulation in impulsive violence as well as a range of clinical disorders. The roles of various areas, including the frontal eye fields (FEF), the pre-supplementary motor area (pre-SMA) and the inferior frontal gyrus, in inhibitory control have been investigated using an inhibitory control task and both transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). Typically effects on response inhibition but no effects on response generation have been seen. The contributions of these areas to performance seem to differ with, for example, pre-SMA being involved when the task is relatively novel whereas this is not the case for FEF. The findings from brain stimulation studies offer both insight into which areas are necessary for effective inhibitory control and recent extension of findings for the role of the inferior frontal gyrus illustrate how the specific functions by which these areas contribute may be further clarified. Future work, including making use of the temporal specificity of TMS and combination of TMS/tDCS with other neuroimaging techniques, may further clarify the nature and functions played by the network of areas involved in inhibitory control. PMID:22494830

  11. Brain Stimulation May Help People with Anorexia

    Science.gov (United States)

    ... 2016 (HealthDay News) -- Brain stimulation may ease major symptoms of the eating disorder anorexia nervosa, a typically hard-to-treat condition, ... these findings suggest that brain stimulation may reduce symptoms of anorexia by ... PLoS One . "Anorexia nervosa is thought to affect up to 4 percent ...

  12. Opiate withdrawal behavior after focal brain stimulation.

    Science.gov (United States)

    Williams, D A; Thorn, B E

    1984-11-01

    Electrical stimulation of the brainstem abolishes pain, while continued stimulation induces tolerance to the analgesic effect. Analgesic drugs producing tolerance also induce physical dependence, suggesting that the phenomenon of tolerance is associated with addiction. There is evidence that the neural mechanism for stimulation-produced analgesia is related to the release of opiate substances within the brain. We therefore propose that repeated or protracted brain stimulation elicits dependence upon the endorphins released by electrical stimulation of the neurons themselves. To investigate this possibility, rats were given repetitive bursts of analgesic electrical brain stimulation for two hours. Immediately thereafter, they were injected with the opiate antagonist, naloxone. Behaviors associated with low grade opiate withdrawal were observed. These data suggest that prolonged analgesic stimulation can result in naloxone-precipitated behaviors similar to the behaviors exhibited during opiate withdrawal. PMID:6542676

  13. Balancing the Brain: Resting State Networks and Deep Brain Stimulation

    OpenAIRE

    Kringelbach, Morten L.

    2011-01-01

    Over the last three decades, large numbers of patients with otherwise treatment-resistant disorders have been helped by deep brain stimulation, yet a full scientific understanding of the underlying neural mechanisms is still missing. We have previously proposed that efficacious deep brain stimulation works by restoring the balance of the brain’s resting state networks. Here, we extend this proposal by reviewing how detailed investigations of the highly coherent functional and structural brain...

  14. Optical and electrochemical methods for determining the effective area and charge density of conducting polymer modified electrodes for neural stimulation.

    Science.gov (United States)

    Harris, Alexander R; Molino, Paul J; Kapsa, Robert M I; Clark, Graeme M; Paolini, Antonio G; Wallace, Gordon G

    2015-01-01

    Neural stimulation is used in the cochlear implant, bionic eye, and deep brain stimulation, which involves implantation of an array of electrodes into a patient's brain. The current passed through the electrodes is used to provide sensory queues or reduce symptoms associated with movement disorders and increasingly for psychological and pain therapies. Poor control of electrode properties can lead to suboptimal performance; however, there are currently no standard methods to assess them, including the electrode area and charge density. Here we demonstrate optical and electrochemical methods for measuring these electrode properties and show the charge density is dependent on electrode geometry. This technique highlights that materials can have widely different charge densities but also large variation in performance. Measurement of charge density from an electroactive area may result in new materials and electrode geometries that improve patient outcomes and reduce side effects. PMID:25495574

  15. Functional MRI during Hippocampal Deep Brain Stimulation in the Healthy Rat Brain.

    Directory of Open Access Journals (Sweden)

    Nathalie Van Den Berge

    Full Text Available Deep Brain Stimulation (DBS is a promising treatment for neurological and psychiatric disorders. The mechanism of action and the effects of electrical fields administered to the brain by means of an electrode remain to be elucidated. The effects of DBS have been investigated primarily by electrophysiological and neurochemical studies, which lack the ability to investigate DBS-related responses on a whole-brain scale. Visualization of whole-brain effects of DBS requires functional imaging techniques such as functional Magnetic Resonance Imaging (fMRI, which reflects changes in blood oxygen level dependent (BOLD responses throughout the entire brain volume. In order to visualize BOLD responses induced by DBS, we have developed an MRI-compatible electrode and an acquisition protocol to perform DBS during BOLD fMRI. In this study, we investigate whether DBS during fMRI is valuable to study local and whole-brain effects of hippocampal DBS and to investigate the changes induced by different stimulation intensities. Seven rats were stereotactically implanted with a custom-made MRI-compatible DBS-electrode in the right hippocampus. High frequency Poisson distributed stimulation was applied using a block-design paradigm. Data were processed by means of Independent Component Analysis. Clusters were considered significant when p-values were <0.05 after correction for multiple comparisons. Our data indicate that real-time hippocampal DBS evokes a bilateral BOLD response in hippocampal and other mesolimbic structures, depending on the applied stimulation intensity. We conclude that simultaneous DBS and fMRI can be used to detect local and whole-brain responses to circuit activation with different stimulation intensities, making this technique potentially powerful for exploration of cerebral changes in response to DBS for both preclinical and clinical DBS.

  16. Bilateral adaptive deep brain stimulation is effective in Parkinson's disease

    Science.gov (United States)

    Little, Simon; Beudel, Martijn; Zrinzo, Ludvic; Foltynie, Thomas; Limousin, Patricia; Hariz, Marwan; Neal, Spencer; Cheeran, Binith; Cagnan, Hayriye; Gratwicke, James; Aziz, Tipu Z; Pogosyan, Alex; Brown, Peter

    2016-01-01

    Introduction & objectives Adaptive deep brain stimulation (aDBS) uses feedback from brain signals to guide stimulation. A recent acute trial of unilateral aDBS showed that aDBS can lead to substantial improvements in contralateral hemibody Unified Parkinson’s Disease Rating Scale (UPDRS) motor scores and may be superior to conventional continuous DBS in Parkinson’s disease (PD). We test whether potential benefits are retained with bilateral aDBS and in the face of concurrent medication. Methods We applied bilateral aDBS in 4 patients with PD undergoing DBS of the subthalamic nucleus. aDBS was delivered bilaterally with independent triggering of stimulation according to the amplitude of β activity at the corresponding electrode. Mean stimulation voltage was 3.0±0.1 volts. Motor assessments consisted of double-blinded video-taped motor UPDRS scores that included both limb and axial features. Results UPDRS scores were 43% (p=0.04; Cohen’s d=1.62) better with aDBS than without stimulation. Motor improvement with aDBS occurred despite an average time on stimulation (ToS) of only 45%. Levodopa was well tolerated during aDBS and led to further reductions in ToS. Conclusion Bilateral aDBS can improve both axial and limb symptoms and can track the need for stimulation across drug states. PMID:26424898

  17. Anaesthetic management of a patient with deep brain stimulation implant for radical nephrectomy

    Directory of Open Access Journals (Sweden)

    Monica Khetarpal

    2014-01-01

    Full Text Available A 63-year-old man with severe Parkinson′s disease (PD who had been implanted with deep brain stimulators into both sides underwent radical nephrectomy under general anaesthesia with standard monitoring. Deep brain stimulation (DBS is an alternative and effective treatment option for severe and refractory PD and other illnesses such as essential tremor and intractable epilepsy. Anaesthesia in the patients with implanted neurostimulator requires special consideration because of the interaction between neurostimulator and the diathermy. The diathermy can damage the brain tissue at the site of electrode. There are no standard guidelines for the anaesthetic management of a patient with DBS electrode in situ posted for surgery.

  18. A randomized double-blind crossover trial comparing subthalamic and pallidal deep brain stimulation for dystonia

    DEFF Research Database (Denmark)

    Schjerling, Lisbeth; Hjermind, Lena E; Jespersen, Bo;

    2013-01-01

    Object The authors' aim was to compare the subthalamic nucleus (STN) with the globus pallidus internus (GPi) as a stimulation target for deep brain stimulation (DBS) for medically refractory dystonia. Methods In a prospective double-blind crossover study, electrodes were bilaterally implanted in ...

  19. Multi-electrode stimulation in somatosensory cortex increases probability of detection

    Science.gov (United States)

    Zaaimi, Boubker; Ruiz-Torres, Ricardo; Solla, Sara A.; Miller, Lee E.

    2013-10-01

    Objective. Brain machine interfaces (BMIs) that decode control signals from motor cortex have developed tremendously in the past decade, but virtually all rely exclusively on vision to provide feedback. There is now increasing interest in developing an afferent interface to replace natural somatosensation, much as the cochlear implant has done for the sense of hearing. Preliminary experiments toward a somatosensory neuroprosthesis have mostly addressed the sense of touch, but proprioception, the sense of limb position and movement, is also critical for the control of movement. However, proprioceptive areas of cortex lack the precise somatotopy of tactile areas. We showed previously that there is only a weak tendency for neighboring neurons in area 2 to signal similar directions of hand movement. Consequently, stimulation with the relatively large currents used in many studies is likely to activate a rather heterogeneous set of neurons. Approach. Here, we have compared the effect of single-electrode stimulation at subthreshold levels to the effect of stimulating as many as seven electrodes in combination. Main results. We found a mean enhancement in the sensitivity to the stimulus (d‧) of 0.17 for pairs compared to individual electrodes (an increase of roughly 30%), and an increase of 2.5 for groups of seven electrodes (260%). Significance. We propose that a proprioceptive interface made up of several hundred electrodes may yield safer, more effective sensation than a BMI using fewer electrodes and larger currents.

  20. Deep brain stimulation for cluster headache

    DEFF Research Database (Denmark)

    Grover, Patrick J; Pereira, Erlick A C; Green, Alexander L;

    2009-01-01

    Cluster headache is a severely debilitating disorder that can remain unrelieved by current pharmacotherapy. Alongside ablative neurosurgical procedures, neuromodulatory treatments of deep brain stimulation (DBS) and occipital nerve simulation have emerged in the last few years as effective...... circumstances to intervene. Here we review current data on neurosurgical interventions for chronic cluster headache focusing upon DBS and occipital nerve stimulation, and discuss the indications for and putative mechanisms of DBS including translational insights from functional neuroimaging, diffusion weighted...

  1. Neurogenic Hippocampal Targets of Deep Brain Stimulation

    OpenAIRE

    Encinas, Juan M.; Hamani, Clement; Lozano, Andres M.; Enikolopov, Grigori

    2011-01-01

    Deep brain stimulation (DBS) is being used to treat movement, neurological, and psychiatric disorders; it has been recently successfully applied to patients with treatment-resistant depression or in minimally conscious state. In addition to its clinical importance, DBS presents a powerful approach to target specific neural circuits and determine the functional relationship between the components of these circuits. We examined the effect of high frequency stimulation of a crucial component of ...

  2. Brain stimulation in posttraumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Vladan Novakovic

    2011-10-01

    Full Text Available Posttraumatic stress disorder (PTSD is a complex, heterogeneous disorder that develops following trauma and often includes perceptual, cognitive, affective, physiological, and psychological features. PTSD is characterized by hyperarousal, intrusive thoughts, exaggerated startle response, flashbacks, nightmares, sleep disturbances, emotional numbness, and persistent avoidance of trauma-associated stimuli. The efficacy of available treatments for PTSD may result in part from relief of associated depressive and anxiety-related symptoms in addition to treatment of core symptoms that derive from reexperiencing, numbing, and hyperarousal. Diverse, heterogeneous mechanisms of action and the ability to act broadly or very locally may enable brain stimulation devices to address PTSD core symptoms in more targeted ways. To achieve this goal, specific theoretical bases derived from novel, well-designed research protocols will be necessary. Brain stimulation devices include both long-used and new electrical and magnetic devices. Electroconvulsive therapy (ECT and Cranial electrotherapy stimulation (CES have both been in use for decades; transcranial magnetic stimulation (TMS, magnetic seizure therapy (MST, deep brain stimulation (DBS, transcranial Direct Current Stimulation (tDCS, and vagus nerve stimulation (VNS have been developed recently, over approximately the past twenty years. The efficacy of brain stimulation has been demonstrated as a treatment for psychiatric and neurological disorders such as anxiety (CES, depression (ECT, CES, rTMS, VNS, DBS, obsessive-compulsive disorder (OCD (DBS, essential tremor, dystonia (DBS, epilepsy (DBS, VNS, Parkinson Disease (DBS, pain (CES, and insomnia (CES. To date, limited data on brain stimulation for PTSD offer only modest guidance. ECT has shown some efficacy in reducing comorbid depression in PTSD patients but has not been demonstrated to improve most core PTSD symptoms. CES and VNS have shown some efficacy in

  3. Brain stimulation using electromagnetic sources: theoretical aspects.

    OpenAIRE

    Heller, L.; van Hulsteyn, D B

    1992-01-01

    We prove that, at the frequencies generally proposed for extracranial stimulation of the brain, it is not possible, using any superposition of external current sources, to produce a three-dimensional local maximum of the electric field strength inside the brain. The maximum always occurs on a boundary where the conductivity jumps in value. Nevertheless, it may be possible to achieve greater two-dimensional focusing and shaping of the electric field than is currently available. Towards this go...

  4. Analysis of high-perimeter planar electrodes for efficient neural stimulation

    OpenAIRE

    Wei, Xuefeng F.; Grill, Warren M.

    2009-01-01

    Planar electrodes are used in epidural spinal cord stimulation and epidural cortical stimulation. Electrode geometry is one approach to increase the efficiency of neural stimulation and reduce the power required to produce the level of activation required for clinical efficacy. Our hypothesis was that electrode geometries that increased the variation of current density on the electrode surface would increase stimulation efficiency. High-perimeter planar disk electrodes were designed with sinu...

  5. Perceptual Interactions Between Electrodes Using Focused and Monopolar Cochlear Stimulation

    DEFF Research Database (Denmark)

    Marozeau, Jeremy; McDermott, Hugh J.; Swanson, Brett A.;

    2015-01-01

    implement an all-polar (AP) stimulation mode designed to create a focused electrical field. The goal of this experiment was to study the potential benefits of this all-polar mode for reducing uncontrolled electrode interactions compared with the monopolar mode. The five participants who took part in the...

  6. Diaphragmatic activity induced by cortical stimulation: surface versus esophageal electrodes.

    Science.gov (United States)

    Gea, J; Espadaler, J M; Guiu, R; Aran, X; Seoane, L; Broquetas, J M

    1993-02-01

    Evoked responses of the diaphragm can be induced by magnetic cortical stimulation and recorded by either surface or esophageal electrodes. The former recording system is tolerated better by the patient but has potential problems with the specificity of the diaphragmatic signal. This study compares the responses of the diaphragm to cortical stimulation that were recorded simultaneously with surface and esophageal electrodes on seven patients (61 +/- 4 yr) with chronic obstructive pulmonary diseases. Stimuli were delivered in three ventilatory conditions: at baseline, during deep breathing, and during voluntary panting. No differences were observed between results recorded by surface and esophageal electrodes [amplitude of the compound motor of the action potential (CMAP), 0.8 +/- 0.1 vs. 0.8 +/- 0.1 mV, NS; latency, 13.1 +/- 0.4 vs. 12.6 +/- 0.5 ms, NS]. In addition, significant correlations were found (CMAP, r = 0.77, P < 0.001; latency, r = 0.71, P = 0.002). The concordance analysis, however, indicated some dissimilarity between the recordings of the electrodes (CMAP, R1 = 0.31; latency, R1 = 0.26). These differences may be due to the area of the muscle mainly recorded by each electrode and/or to the additional activity from other muscles recorded by surface electrodes. On the other hand, the diaphragmatic responses observed in these patients with chronic obstructive pulmonary diseases were similar to those previously reported in healthy subjects. PMID:8458780

  7. Network effects of deep brain stimulation.

    Science.gov (United States)

    Alhourani, Ahmad; McDowell, Michael M; Randazzo, Michael J; Wozny, Thomas A; Kondylis, Efstathios D; Lipski, Witold J; Beck, Sarah; Karp, Jordan F; Ghuman, Avniel S; Richardson, R Mark

    2015-10-01

    The ability to differentially alter specific brain functions via deep brain stimulation (DBS) represents a monumental advance in clinical neuroscience, as well as within medicine as a whole. Despite the efficacy of DBS in the treatment of movement disorders, for which it is often the gold-standard therapy when medical management becomes inadequate, the mechanisms through which DBS in various brain targets produces therapeutic effects is still not well understood. This limited knowledge is a barrier to improving efficacy and reducing side effects in clinical brain stimulation. A field of study related to assessing the network effects of DBS is gradually emerging that promises to reveal aspects of the underlying pathophysiology of various brain disorders and their response to DBS that will be critical to advancing the field. This review summarizes the nascent literature related to network effects of DBS measured by cerebral blood flow and metabolic imaging, functional imaging, and electrophysiology (scalp and intracranial electroencephalography and magnetoencephalography) in order to establish a framework for future studies. PMID:26269552

  8. Future of brain stimulation: new targets, new indications, new technology.

    Science.gov (United States)

    Hariz, Marwan; Blomstedt, Patric; Zrinzo, Ludvic

    2013-11-01

    In the last quarter of a century, DBS has become an established neurosurgical treatment for Parkinson's disease (PD), dystonia, and tremors. Improved understanding of brain circuitries and their involvement in various neurological and psychiatric illnesses, coupled with the safety of DBS and its exquisite role as a tool for ethical study of the human brain, have unlocked new opportunities for this technology, both for future therapies and in research. Serendipitous discoveries and advances in structural and functional imaging are providing abundant "new" brain targets for an ever-increasing number of pathologies, leading to investigations of DBS in diverse neurological, psychiatric, behavioral, and cognitive conditions. Trials and "proof of concept" studies of DBS are underway in pain, epilepsy, tinnitus, OCD, depression, and Gilles de la Tourette syndrome, as well as in eating disorders, addiction, cognitive decline, consciousness, and autonomic states. In parallel, ongoing technological development will provide pulse generators with longer battery longevity, segmental electrode designs allowing a current steering, and the possibility to deliver "on-demand" stimulation based on closed-loop concepts. The future of brain stimulation is certainly promising, especially for movement disorders-that will remain the main indication for DBS for the foreseeable future-and probably for some psychiatric disorders. However, brain stimulation as a technique may be at risk of gliding down a slippery slope: Some reports indicate a disturbing trend with suggestions that future DBS may be proposed for enhancement of memory in healthy people, or as a tool for "treatment" of "antisocial behavior" and for improving "morality." PMID:24123327

  9. Complementary Metal Oxide Semiconductor Based Multimodal Sensor for In vivo Brain Function Imaging with a Function for Simultaneous Cell Stimulation

    Science.gov (United States)

    Tagawa, Ayato; Mitani, Masahiro; Minami, Hiroki; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Ohta, Jun

    2010-04-01

    We have developed a multimodal complementary metal oxide semiconductor (CMOS) sensor device embedded with Au electrodes for fluorescent imaging and cell stimulation in the deep brain of mice. The Au electrodes were placed on the pixel array of the image sensor. Windows over the photodiodes were opened in the electrode area for simultaneous fluorescent imaging and cell stimulation in the same area of the brain tissue. The sensor chip was shaped like a shank and was packaged by two packaging methods for high strength or minimal invasion. The experimental results showed that the 90 ×90 µm2 Au electrodes with windows were capable of injecting theta burst stimulation (TBS)-like current pulses at 0.2-1 mA in a saline solution. We successfully demonstrated that fluorescent imaging and TBS-like current injection can be simultaneously performed in the electrode area of a brain phantom.

  10. Deep Brain Stimulation og Identitet i Fremtiden

    OpenAIRE

    Andersen, Camilla; Farah, Adna; Pil, Kierkegaard; Lucas, Haasum

    2015-01-01

    The rapidly progressing technology of today is the impetus for increased interest and discussion regarding transhumanism. As a result, our group has decided to conduct research regarding deep brain stimulation, in order to focus on a single technology that is growing rapidly and seeing multiple uses in treating various neurological pathologies. The possibilities of the technology will be relevant to the future of transhuman though, as well as the immediate effects on the individuals who elec...

  11. Evaluation of novel stimulus waveforms for deep brain stimulation

    Science.gov (United States)

    Foutz, Thomas J.; McIntyre, Cameron C.

    2010-12-01

    Deep brain stimulation (DBS) is an established therapy for the treatment of a wide range of neurological disorders. Historically, DBS and other neurostimulation technologies have relied on rectangular stimulation waveforms to impose their effects on the nervous system. Recent work has suggested that non-rectangular waveforms may have advantages over the traditional rectangular pulse. Therefore, we used detailed computer models to compare a range of charge-balanced biphasic waveforms with rectangular, exponential, triangular, Gaussian and sinusoidal stimulus pulse shapes. We explored the neural activation energy of these waveforms for both intracellular and extracellular current-controlled stimulation conditions. In the context of extracellular stimulation, we compared their effects on both axonal fibers of passage and projection neurons. Finally, we evaluated the impact of delivering the waveforms through a clinical DBS electrode, as opposed to a theoretical point source. Our results suggest that DBS with a 1 ms centered-triangular pulse can decrease energy consumption by 64% when compared with the standard 100 µs rectangular pulse (energy cost of 48 and 133 nJ, respectively, to stimulate 50% of a distributed population of axons) and can decrease energy consumption by 10% when compared with the most energy efficient rectangular pulse (1.25 ms duration). In turn, there may be measureable energy savings when using appropriately designed non-rectangular pulses in clinical DBS applications, thereby warranting further experimental investigation.

  12. Effects of stimulation parameters and electrode location on thresholds for epidural stimulation of cat motor cortex

    Science.gov (United States)

    Wongsarnpigoon, Amorn; Grill, Warren M.

    2011-12-01

    Epidural electrical stimulation (ECS) of the motor cortex is a developing therapy for neurological disorders. Both placement and programming of ECS systems may affect the therapeutic outcome, but the treatment parameters that will maximize therapeutic outcomes and minimize side effects are not known. We delivered ECS to the motor cortex of anesthetized cats and investigated the effects of electrode placement and stimulation parameters on thresholds for evoking motor responses in the contralateral forelimb. Thresholds were inversely related to stimulation frequency and the number of pulses per stimulus train. Thresholds were lower over the forelimb representation in motor cortex (primary site) than surrounding sites (secondary sites), and thresholds at sites 4 mm away. Electrode location and montage influenced the effects of polarity on thresholds: monopolar anodic and cathodic thresholds were not significantly different over the primary site, cathodic thresholds were significantly lower than anodic thresholds over secondary sites and bipolar thresholds were significantly lower with the anode over the primary site than with the cathode over the primary site. A majority of bipolar thresholds were either between or equal to the respective monopolar thresholds, but several bipolar thresholds were greater than or less than the monopolar thresholds of both the anode and cathode. During bipolar stimulation, thresholds were influenced by both electric field superposition and indirect, synaptically mediated interactions. These results demonstrate the influence of stimulation parameters and electrode location during cortical stimulation, and these effects should be considered during the programming of systems for therapeutic cortical stimulation.

  13. A Programmable High-Voltage Compliance Neural Stimulator for Deep Brain Stimulation in Vivo

    Directory of Open Access Journals (Sweden)

    Cihun-Siyong Alex Gong

    2015-05-01

    Full Text Available Deep brain stimulation (DBS is one of the most effective therapies for movement and other disorders. The DBS neurosurgical procedure involves the implantation of a DBS device and a battery-operated neurotransmitter, which delivers electrical impulses to treatment targets through implanted electrodes. The DBS modulates the neuronal activities in the brain nucleus for improving physiological responses as long as an electric discharge above the stimulation threshold can be achieved. In an effort to improve the performance of an implanted DBS device, the device size, implementation cost, and power efficiency are among the most important DBS device design aspects. This study aims to present preliminary research results of an efficient stimulator, with emphasis on conversion efficiency. The prototype stimulator features high-voltage compliance, implemented with only a standard semiconductor process, without the use of extra masks in the foundry through our proposed circuit structure. The results of animal experiments, including evaluation of evoked responses induced by thalamic electrical stimuli with our fabricated chip, were shown to demonstrate the proof of concept of our design.

  14. Performance of conducting polymer electrodes for stimulating neuroprosthetics

    Science.gov (United States)

    Green, R. A.; Matteucci, P. B.; Hassarati, R. T.; Giraud, B.; Dodds, C. W. D.; Chen, S.; Byrnes-Preston, P. J.; Suaning, G. J.; Poole-Warren, L. A.; Lovell, N. H.

    2013-02-01

    Objective. Recent interest in the use of conducting polymers (CPs) for neural stimulation electrodes has been growing; however, concerns remain regarding the stability of coatings under stimulation conditions. These studies examine the factors of the CP and implant environment that affect coating stability. The CP poly(ethylene dioxythiophene) (PEDOT) is examined in comparison to platinum (Pt), to demonstrate the potential performance of these coatings in neuroprosthetic applications. Approach. PEDOT is coated on Pt microelectrode arrays and assessed in vitro for charge injection limit and long-term stability under stimulation in biologically relevant electrolytes. Physical and electrical stability of coatings following ethylene oxide (ETO) sterilization is established and efficacy of PEDOT as a visual prosthesis bioelectrode is assessed in the feline model. Main results. It was demonstrated that PEDOT reduced the potential excursion at a Pt electrode interface by 72% in biologically relevant solutions. The charge injection limit of PEDOT for material stability was found to be on average 30× larger than Pt when tested in physiological saline and 20× larger than Pt when tested in protein supplemented media. Additionally stability of the coating was confirmed electrically and morphologically following ETO processing. It was demonstrated that PEDOT-coated electrodes had lower potential excursions in vivo and electrically evoked potentials (EEPs) could be detected within the visual cortex. Significance. These studies demonstrate that PEDOT can be produced as a stable electrode coating which can be sterilized and perform effectively and safely in neuroprosthetic applications. Furthermore these findings address the necessity for characterizing in vitro properties of electrodes in biologically relevant milieu which mimic the in vivo environment more closely.

  15. Enhancing duration processing with parietal brain stimulation.

    Science.gov (United States)

    Dormal, Valérie; Javadi, Amir-Homayoun; Pesenti, Mauro; Walsh, Vincent; Cappelletti, Marinella

    2016-05-01

    Numerosity and duration are thought to share common magnitude-based mechanisms in brain regions including the right parietal and frontal cortices like the supplementary motor area, SMA. Numerosity and duration are, however, also different in several intrinsic features. For instance, in a quantification context, numerosity is known for being more automatically accessed than temporal events, and durations are by definition sequential whereas numerosity can be both sequential and simultaneous. Moreover, numerosity and duration processing diverge in terms of their neuronal correlates. Whether these observed neuronal specificities can be accounted for by differences in automaticity or presentation-mode is however not clear. To address this issue, we used brain stimulation (transcranial random noise stimulation, tRNS) to the right parietal cortex or the SMA combined with experimental stimuli differing in their level of automaticity (numerosity and duration) and presentation mode (sequential or simultaneous). Compared to a no stimulation group, performance changed in duration but not in numerosity categorisation following right parietal but not SMA stimulation. These results indicate that the right parietal cortex is critical for duration processing, and suggest that tRNS has a stronger effect on less automatic processes such as duration. PMID:27037043

  16. Neuroethics: The Ethics and History Behind Deep Brain Stimulation

    OpenAIRE

    Simmonds, Matthew; Franck, Jannick

    2014-01-01

    In this Project we have tried to answer the Question: What is the history leading up to the development of Deep Brain Stimulation, and what are the ethical implications to the ethics of neuroscience? Has the historical background of psychosurgery affected the ethical climate now in regards to Deep Brain Stimulation, and are there any challenges to Deep Brain Stimulation’s future? We have gone through the historical background leading up to the use of Deep Brain Stimulation, and we discuss ...

  17. Deep Brain Electrical Stimulation in Epilepsy

    Science.gov (United States)

    Rocha, Luisa L.

    2008-11-01

    The deep brain electrical stimulation has been used for the treatment of neurological disorders such as Parkinson's disease, chronic pain, depression and epilepsy. Studies carried out in human brain indicate that the application of high frequency electrical stimulation (HFS) at 130 Hz in limbic structures of patients with intractable temporal lobe epilepsy abolished clinical seizures and significantly decreased the number of interictal spikes at focus. The anticonvulsant effects of HFS seem to be more effective in patients with less severe epilepsy, an effect associated with a high GABA tissue content and a low rate of cell loss. In addition, experiments using models of epilepsy indicate that HFS (pulses of 60 μs width at 130 Hz at subthreshold current intensity) of specific brain areas avoids the acquisition of generalized seizures and enhances the postictal seizure suppression. HFS is also able to modify the status epilepticus. It is concluded that the effects of HFS may be a good strategy to reduce or avoid the epileptic activity.

  18. Preparation of etched tantalum semimicro capacitor stimulation electrodes.

    Science.gov (United States)

    Robblee, L S; Kelliher, E M; Langmuir, M E; Vartanian, H; McHardy, J

    1983-03-01

    The ideal electrode for stimulation of the nervous system is one that will inject charge by purely capacitive processes. One approach is to exploit the type of metal-oxide combination used in electrolytic capacitors, e.g., Ta/Ta2O5. For this purpose, fine tantalum wire (0.25 mm diam) was etched electrolytically at constant current in a methanol solution of NH4Br containing 1.5 wt % H2O. Electrolytic etching produced a conical tip with a length of ca. 0.5 mm and shaft diameters ranging from 0.10 to 0.16 mm. The etched electrodes were anodized to 10 V (vs. SCE) in 0.1 vol % H3PO4. The capacitance values normalized to geometric area of etched electrodes ranged from 0.13 to 0.33 micro F mm-2. Comparison of these values to the capacitance of "smooth" tantalum anodized to 10 V (0.011 micro F mm-2) indicated that the degree of surface enhancement, or etch ratio, was 12-30. The surface roughness was confirmed by scanning electron microscopy studies which revealed an intricate array of irregularly shaped surface projections about 1-2 micrometers wide. The etched electrodes were capable of delivering 0.06-0.1 micro C of charge with 0.1 ms pulses at a pulse repetition rate of 400 Hz when operated at 50% of the anodization voltage. This quantity of charge corresponded to volumetric charge densities of 20-30 micro C mm-3 and area charge densities of 0.55-0.88 micro C mm-2. Charge storage was proportionately higher at higher fractional values of the formation voltage. Leakage currents at 5 V were ca. 2 nA. Neither long-term passive storage (1500 h) nor extended pulsing time (18 h) had a deleterious effect on electrode performance. The trend in electrical stimulation work is toward smaller electrodes. The procedures developed in this study should be particularly well-suited to the fabrication of even smaller electrodes because of the favorable electrical and geometric characteristics of the etched surface. PMID:6841372

  19. Analysis of high-perimeter planar electrodes for efficient neural stimulation

    Directory of Open Access Journals (Sweden)

    Xuefeng F Wei

    2009-11-01

    Full Text Available Planar electrodes are used in epidural spinal cord stimulation and epidural cortical stimulation. Electrode geometry is one approach to increase the efficiency of neural stimulation and reduce the power required to produce the level of activation required for clinical efficacy. Our hypothesis was that electrode geometries that increased the variation of current density on the electrode surface would increase stimulation efficiency. High-perimeter planar disk electrodes were designed with sinuous (serpentine variation in the perimeter. Prototypes were fabricated that had equal surface areas but perimeters equal to 2, 3 or 4 times the perimeter of a circular disk electrode. The interface impedance of high-perimeter prototype electrodes measured in vitro did not differ significantly from that of the circular electrode over a wide range of frequencies. Finite element models indicated that the variation of current density was significantly higher on the surface of the high-perimeter electrodes. We quantified activation of 100 model axons randomly positioned around the electrodes. Input-output curves of the percentage of axons activated as a function of stimulation intensity indicated that the stimulation efficiency was dependent on the distance of the axons from the electrode. The high-perimeter planar electrodes were more efficient at activating axons a certain distance away from the electrode surface. These results demonstrate the feasibility of increasing stimulation efficiency through the design of novel electrode geometries.

  20. Deep brain stimulation as a treatment for Parkinson's disease

    OpenAIRE

    Von Heymann-Horan, Kevin; Zoet, Amir; Primdahl Nielsen, Mie; Becher Østerbøg, Tina

    2012-01-01

    This project is an examination of the use of deep brain stimulation (DBS) in the treatment of Parkinson's disease. The project contains an overview of the areas of the brain that are affected by Parkinson's disease and that are targeted by deep brain stimulation for treatment. The function and anatomy of these regions are discussed. The history of deep brain stimulation is examined, as are new methods and theories as to how deep brain stimulation can be used more effectively to treat not only...

  1. Deep brain stimulation for major depression.

    Science.gov (United States)

    Schlaepfer, T E; Bewernick, B H

    2013-01-01

    A third of patients suffering from major depression cannot be helped by conventional treatment methods. These patients face reduced quality of life, high risk of suicide, and little hope of recovery. Deep brain stimulation (DBS) is under scientific evaluation as a new treatment option for these treatment-resistant patients. First clinical studies with small samples have been stimulated at the subgenual cingulate gyrus (Cg25/24), the anterior limb of the capsula interna (ALIC), and the nucleus accumbens (NAcc). Long-term antidepressant effects, augmentation of social functioning, and normalization of brain metabolism have been shown in about 50% of patients. Cognitive safety regarding attention, learning, and memory has been reported. Adverse events were wound infection, suicide, and hypomania, amongst others. Larger studies are under way to confirm these preliminary encouraging results. New hypothesis-guided targets (e.g., medial forebrain bundle, habenula) are about to be assessed in clinical trials. The application of DBS for other psychiatric diseases (e.g., bipolar disorder, alcohol dependency, opioid addiction, schizophrenia) is debated and single case studies are under way. Standards are needed for study registration, target selection, patient inclusion and monitoring, and publication of results to guarantee safety for the patients and scientific exchange. PMID:24112897

  2. Neuropsychiatric deep brain stimulation for translational neuroimaging.

    Science.gov (United States)

    Höflich, Anna; Savli, Markus; Comasco, Erika; Moser, Ulrike; Novak, Klaus; Kasper, Siegfried; Lanzenberger, Rupert

    2013-10-01

    From a neuroimaging point of view, deep brain stimulation (DBS) in psychiatric disorders represents a unique source of information to probe results gained in functional, structural and molecular neuroimaging studies in vivo. However, the implementation has, up to now, been restricted by the heterogeneity of the data reported in DBS studies. The aim of the present study was therefore to provide a comprehensive and standardized database of currently used DBS targets in selected psychiatric disorders (obsessive-compulsive disorder (OCD), treatment-resistant depression (TRD), Gilles de la Tourette syndrome (GTS)) to enable topological comparisons between neuroimaging results and stimulation areas. A systematic literature research was performed and all peer-reviewed publications until the year 2012 were included. Literature research yielded a total of 84 peer-reviewed studies including about 296 psychiatric patients. The individual stimulation data of 37 of these studies meeting the inclusion criteria which included a total of 202 patients (63 OCD, 89 TRD, 50 GTS) was translated into MNI stereotactic space with respect to AC origin in order to identify key targets. The created database can be used to compare DBS target areas in MNI stereotactic coordinates with: 1) activation patterns in functional brain imaging (fMRI, phfMRI, PET, MET, EEG); 2) brain connectivity data (e.g., MR-based DTI/tractography, functional and effective connectivity); 3) quantitative molecular distribution data (e.g., neuroreceptor PET, post-mortem neuroreceptor mapping); 4) structural data (e.g., VBM for neuroplastic changes). Vice versa, the structural, functional and molecular data may provide a rationale to define new DBS targets and adjust/fine-tune currently used targets in DBS based on this overview in stereotactic coordinates. Furthermore, the availability of DBS data in stereotactic space may facilitate the investigation and interpretation of treatment effects and side effect of DBS by

  3. Unilateral neuromodulation of the ventromedial hypothalamus of the rat through deep brain stimulation

    Science.gov (United States)

    Lehmkuhle, M. J.; Mayes, S. M.; Kipke, D. R.

    2010-06-01

    This study offers evidence that long-term deep brain stimulation of the ventromedial hypothalamus (VMH) can alter weight gain in mammals without affecting feeding behavior. Animals stimulated unilaterally at high frequencies of 150 or 500 Hz demonstrated increased CO2 production that decreased from prestimulation levels after the stimulation was removed. Animals stimulated for up to 6 weeks gained weight at a lower rate than normal animals or animals implanted with an electrode but not stimulated. Stimulated animals exhibited normal food and water consumption. A significant decrease in efficiency was observed during stimulation that coincided with an increase in the amount of feces produced. Whereas the weight of control animals was significantly different from week to week, the weight of stimulated animals did not change accordingly. These data suggest that the VMH may be a viable target for long-term deep brain stimulation for modulation of the neural mechanisms of metabolism. The potential therapeutic effects of deep brain stimulation of the hypothalamus are discussed.

  4. Deep brain stimulation to reduce sexual drive

    Science.gov (United States)

    Fuss, Johannes; Auer, Matthias K.; Biedermann, Sarah V.; Briken, Peer; Hacke, Werner

    2015-01-01

    To date there are few treatment options to reduce high sexual drive or sexual urges in paraphilic patients with a risk for sexual offending. Pharmacological therapy aims to reduce sexual drive by lowering testosterone at the cost of severe side effects. We hypothesize that high sexual drive could also be reduced with deep brain stimulation (DBS) of circuits that generate sexual drive. This approach would help to avoid systemic side effects of antiandrogenic drug therapies. So far the best investigated target to reduce sexual drive is the ventromedial hypothalamus, which was lesioned unilaterally and bilaterally by stereotaxic interventions in paraphilic patients in the 1970s. Here, we discuss DBS as a treatment strategy in patients with severe paraphilic disorders with a serious risk of sexual offending. There are profound ethical and practical issues associated with DBS treatment of paraphilic patients that must be solved before considering such a treatment approach. PMID:26057198

  5. Evidence of the enhancement effect in electrical stimulation via electrode matching (L)

    OpenAIRE

    Goupell, Matthew J.; Mostardi, Mitchell J.

    2012-01-01

    The ability to match a pulsing electrode during multi-electrode stimulation through a research interface was measured in seven cochlear-implant (CI) users. Five listeners were relatively good at the task and two could not perform the task. Performance did not vary as a function of the number of electrodes or stimulation level. Performance on the matching task was not correlated to performance on an electrode-discrimination task. The listeners may have experienced the auditory enhancement effe...

  6. Origin and evolution of deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Vittorio Alessandro eSironi

    2011-08-01

    Full Text Available This paper briefly describes how the electrical stimulation, used since antiquity to modulate the nervous system, has been a fundamental tool of neurophysiologic investigation in the second half of the 18th century and was subsequently used by the early 20th century, even for therapeutic purposes. In mid-20th century the advent of stereotactic procedures has allowed the drift from lesional to stimulating technique of deep nuclei of the brain for therapeutic purposes. In this way, DBS was born, that, over the last two decades, has led to positive results for the treatment of medically refractory Parkinson's disease, essential tremor and dystonia. In recent years, the indications for therapeutic use of DBS have been extended to epilepsy, Tourette's syndrome, psychiatric diseases (depression, obsessive-compulsive disorder, some kinds of headache, eating disorders and the minimally conscious state. The potentials of the DBS for therapeutic use are fascinating, but there are still many unresolved technical and ethical problems, concerning the identification of the targets for each disease, the selection of the patients and the evaluation of the results.

  7. Emerging applications of deep brain stimulation.

    Science.gov (United States)

    Sharma, Mayur; Naik, Vikas; Deogaonkar, Milind

    2016-06-01

    Deep brain stimulation (DBS) implantation surgery is an established treatment modality for a variety of medical refractory movement disorders such as Parkinson's disease, essential tremors and dystonia. Following the success of DBS in these movement disorders with a high rate of safety and efficacy, there is a resurgence of interest in the utility of this modality in other medical refractory disorders. Consequently, neuromodulation has been explored for a variety of refractory conditions such as neuropsychiatric disorders (major depressive disorders, obsessive-compulsive disorders, addictions), eating disorders including obesity, traumatic brain injury, post-traumatic stress disorders (PTSD), dementias and chronic pain. This review provides an overview of the emerging applications of DBS in these disorders, including summary of the published literature. We have highlighted the pathophysiology and likely aberrant neural circuits involved in these refractory disorders. Current and possible surgical targets for neurosurgical intervention related to these disorders have also been discussed. Furthermore, recent advances such as closed loop systems; responsive neurostimulation systems and optogenetics techniques have been addressed. PMID:26788743

  8. Deep brain stimulation for Parkinson's disease dissociates mood and motor circuits: a functional MRI case study.

    Science.gov (United States)

    Stefurak, Taresa; Mikulis, David; Mayberg, Helen; Lang, Anthony E; Hevenor, Stephanie; Pahapill, Peter; Saint-Cyr, Jean; Lozano, Andres

    2003-12-01

    Behavioral disturbances have been reported with subthalamic (STN) deep brain stimulation (DBS) treatment in Parkinson's disease (PD). We report correlative functional imaging (fMRI) of mood and motor responses induced by successive right and left DBS. A 36-year-old woman with medically refractory PD and a history of clinically remitted depression underwent uncomplicated implantation of bilateral STN DBS. High-frequency stimulation of the left electrode improved motor symptoms. Unexpectedly, right DBS alone elicited several reproducible episodes of acute depressive dysphoria. Structural and functional magnetic resonance imaging (fMRI) imaging was carried out with sequential individual electrode stimulation. The electrode on the left was within the inferior STN, whereas the right electrode was marginally superior and lateral to the intended STN target within the Fields of Forel/zona incerta. fMRI image analysis (Analysis of Functional NeuroImages, AFNI) contrasting OFF versus ON stimulation identified significant lateralized blood oxygen level-dependent (BOLD) signal changes with DBS (P disturbance resolved spontaneously in 4 weeks despite identical stimulation parameters. Transient depressive mood induced by subcortical DBS stimulation was correlated with changes in mesolimbic cortical structures. This case provides new evidence supporting cortical segregation of motor and nonmotor cortico-basal ganglionic systems that may converge in close proximity at the level of the STN and the adjacent white matter tracts (Fields of Forel/zona incerta). PMID:14673888

  9. Early Brain Stimulation May Help Stroke Survivors Recover Language Function

    Science.gov (United States)

    ... Hub Making News on Heart.org Learn More Early brain stimulation may help stroke survivors recover language function June ... the therapy session,” Thiel said. “We believe brain stimulation should be most effective early, within about five weeks after stroke, because genes ...

  10. Stimulation-Based Control of Dynamic Brain Networks.

    Science.gov (United States)

    Muldoon, Sarah Feldt; Pasqualetti, Fabio; Gu, Shi; Cieslak, Matthew; Grafton, Scott T; Vettel, Jean M; Bassett, Danielle S

    2016-09-01

    The ability to modulate brain states using targeted stimulation is increasingly being employed to treat neurological disorders and to enhance human performance. Despite the growing interest in brain stimulation as a form of neuromodulation, much remains unknown about the network-level impact of these focal perturbations. To study the system wide impact of regional stimulation, we employ a data-driven computational model of nonlinear brain dynamics to systematically explore the effects of targeted stimulation. Validating predictions from network control theory, we uncover the relationship between regional controllability and the focal versus global impact of stimulation, and we relate these findings to differences in the underlying network architecture. Finally, by mapping brain regions to cognitive systems, we observe that the default mode system imparts large global change despite being highly constrained by structural connectivity. This work forms an important step towards the development of personalized stimulation protocols for medical treatment or performance enhancement. PMID:27611328

  11. Deep Brain Stimulation Alleviates Parkinsonian Bradykinesia by Regularizing Pallidal Activity

    OpenAIRE

    Dorval, Alan D.; Kuncel, Alexis M.; Birdno, Merrill J.; Turner, Dennis A.; Grill, Warren M.

    2010-01-01

    Deep brain stimulation (DBS) of the basal ganglia can alleviate the motor symptoms of Parkinson's disease although the therapeutic mechanisms are unclear. We hypothesize that DBS relieves symptoms by minimizing pathologically disordered neuronal activity in the basal ganglia. In human participants with parkinsonism and clinically effective deep brain leads, regular (i.e., periodic) high-frequency stimulation was replaced with irregular (i.e., aperiodic) stimulation at the same mean frequency ...

  12. Brain stimulation in patients with disorders of consciousness

    OpenAIRE

    Thibaut, Aurore; Laureys, Steven

    2015-01-01

    Background and Aim: There is a long history of brain stimulation in medical science, and it was tested for years trying to treat several neurological diseases. On the other hand, the treatment choices for patients with severe brain injury resulting in disorders of consciousness (DOC) are still limited and research in this field remains challenging. In the current literature, only a few techniques of brain stimulation were studied in this population of patients. This review describes noninvasi...

  13. Repetitive transcranial magnetic stimulation activates specific regions in rat brain

    OpenAIRE

    Ji, Ru-Rong; Schlaepfer, Thomas E.; Aizenman, Carlos D.; Epstein, Charles M.; Qiu, Dike; Huang, Justin C.; Rupp, Fabio

    1998-01-01

    Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS and electroconvulsive stimulation, a well-established animal model for electroconvulsive ther...

  14. Brain stimulation for intractable epilepsy: Anterior thalamus and responsive stimulation

    OpenAIRE

    2014-01-01

    Despite medications, resective surgery, and vagal nerve stimulation, some patients with epilepsy continue to have seizures. In these patients, other approaches are urgently needed. The biological basis of stimulation of anterior thalamic nucleus and epileptogenic focus is presented. Results from two large randomized controlled trials Stimulation of Anterior Nucleus of Thalamus for Epilepsy (SANTE) and Neuropace pivotal trial are discussed. Neuromodulation provides effective treatment for a se...

  15. Ethical issues in deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Maartje eSchermer

    2011-05-01

    Full Text Available Deep brain stimulation (DBS is currently used to treat neurological disorders like Parkinson’s disease (PD, essential tremor and dystonia, and is explored as an experimental treatment for psychiatric disorders like Major Depression (MD and Obsessive Compulsive Disorder (OCD. This mini review discusses ethical issues in DBS treatment and research, as they have been discussed in the medical and ethical literature.With regard to DBS treatment, the most important issues are balancing risks and benefits and ensuring respect for the autonomous wish of the patient. This implies special attention to patient selection, psycho-social impact of treatment, effects on personal identity, and treatment of children. Moreover, it implies a careful informed consent process in which unrealistic expectations of patients and their families are addressed and in which special attention is given to competence. In the context of research, the fundamental ethical challenge is to promote high-quality scientific research in the interest of future patients, while at the same time safeguarding the rights and interests of vulnerable research subjects. Several guidelines have been proposed to ensure this. One of the preconditions to further development of responsible and transparent research practices is the establishment of a comprehensive registry.

  16. Deep brain stimulation for Tourette syndrome.

    Science.gov (United States)

    Visser-Vandewalle, V; Kuhn, J

    2013-01-01

    Tourette syndrome is a neuropsychiatric disorder characterized by motor and vocal tics, often associated with behavioral disorders, with typical onset in early childhood. In most patients, the symptoms decrease spontaneously when adulthood is reached, or can be treated with behavioral therapy or medication. Only a small proportion of patients are candidates for surgical treatment. In 1999, thalamic deep brain stimulation (DBS) was introduced for intractable Tourette syndrome. Since then, a diversity of targets have been used, located mainly at the level of the medial part of the thalamus, in the globus pallidus internus (anteromedial limbic and posteroventrolateral motor part), the globus pallidus externus, and the internal capsule/nucleus accumbens. The pathophysiology of Tourette syndrome is still a matter of considerable debate. Current knowledge of cortical-basal ganglia-thalamocortical circuits provides explanations for the beneficial effects of DBS on tics. Inclusion and exclusion criteria have been formulated to identify good candidates for DBS. Because of the small number of patients, there is a strong need for multicenter double-blind trials with standard protocols. PMID:24112899

  17. An optimal spatial filtering electrode for brain computer interface.

    Science.gov (United States)

    Besio, W G; Kay, S M; Liu, X

    2009-01-01

    There are millions of people in the U.S. and many more worldwide who could benefit from a noninvasive-based electroencephalography (EEG) brain computer interface (BCI). A BCI is an alternative or augmentative communication method for people with severe motor disabilities. However, EEG suffers from poor spatial resolution and signal-to-noise ratio (SNR). To improve the spatial resolution and SNR many researchers have turned to implantable electrodes. We have previously reported on significant improvements in BCI recognition rates using tripolar concentric ring electrodes compared to disc electrodes. We now report on a optimal method for combining the outputs from the independent elements of the tripolar concentric ring electrodes to improve the spatial resolution further. We used minimum variance distortionless look (MVDL), a beamformer, on simulated data to compare the spatial sensitivity of the optimal combination to disc electrodes and the tripolar concentric ring electrode surface Laplacian. The optimal combination shows the highest spatial sensitivity with the Laplacian a close second and disc electrodes resulting in a distant third. Further analysis is necessary with a more realistic computer model and then real signals. however it appears that the optimal combination may improve the spatial resolution of EEG further which in turn can be utilized to improve noninvasive EEG-based BCIs. PMID:19963573

  18. Changes in brain gray matter due to repetitive painful stimulation.

    Science.gov (United States)

    Teutsch, S; Herken, W; Bingel, U; Schoell, E; May, A

    2008-08-15

    Using functional imaging, we recently investigated how repeated painful stimulation over several days is processed, perceived and modulated in the healthy human brain. Considering that activation-dependent brain plasticity in humans on a structural level has already been demonstrated in adults, we were interested in whether repeated painful stimulation may lead to structural changes of the brain. 14 healthy subjects were stimulated daily with a 20 min pain paradigm for 8 consecutive days, using structural MRI performed on days 1, 8, 22 and again after 1 year. Using voxel based morphometry, we are able to show that repeated painful stimulation resulted in a substantial increase of gray matter in pain transmitting areas, including mid-cingulate and somatosensory cortex. These changes are stimulation dependent, i.e. they recede after the regular nociceptive input is stopped. This data raises some interesting questions regarding structural plasticity of the brain concerning the experience of both acute and chronic pain. PMID:18582579

  19. Theory of feedback controlled brain stimulations for Parkinson's disease

    Science.gov (United States)

    Sanzeni, A.; Celani, A.; Tiana, G.; Vergassola, M.

    2016-01-01

    Limb tremor and other debilitating symptoms caused by the neurodegenerative Parkinson's disease are currently treated by administering drugs and by fixed-frequency deep brain stimulation. The latter interferes directly with the brain dynamics by delivering electrical impulses to neurons in the subthalamic nucleus. While deep brain stimulation has shown therapeutic benefits in many instances, its mechanism is still unclear. Since its understanding could lead to improved protocols of stimulation and feedback control, we have studied a mathematical model of the many-body neural network dynamics controlling the dynamics of the basal ganglia. On the basis of the results obtained from the model, we propose a new procedure of active stimulation, that depends on the feedback of the network and that respects the constraints imposed by existing technology. We show by numerical simulations that the new protocol outperforms the standard ones for deep brain stimulation and we suggest future experiments that could further improve the feedback procedure.

  20. Deep brain stimulation af behandlingsrefraktaer, invaliderende dystoni. Dansk Selskab for Bevaegeforstyrrelser (Danmodis)

    DEFF Research Database (Denmark)

    Hjermind, Lena E; Løkkegaard, Annemette; Werdelin, Lene M; Regeur, Lisbeth; Jespersen, Bo; Madsen, Flemming Find; Badakhshani, Karim; Dupont, Erik; Sunde, Niels Aagaard; Sørensen, Jens Christian; Ostergaard, Karen; Karlsborg, Merete

    Deep brain stimulation af behandlingsrefraktaer, invaliderende dystoni. Dansk Selskab for Bevaegeforstyrrelser (Danmodis)......Deep brain stimulation af behandlingsrefraktaer, invaliderende dystoni. Dansk Selskab for Bevaegeforstyrrelser (Danmodis)...

  1. A Simple and Accurate Model to Predict Responses to Multi-electrode Stimulation in the Retina.

    Science.gov (United States)

    Maturana, Matias I; Apollo, Nicholas V; Hadjinicolaou, Alex E; Garrett, David J; Cloherty, Shaun L; Kameneva, Tatiana; Grayden, David B; Ibbotson, Michael R; Meffin, Hamish

    2016-04-01

    Implantable electrode arrays are widely used in therapeutic stimulation of the nervous system (e.g. cochlear, retinal, and cortical implants). Currently, most neural prostheses use serial stimulation (i.e. one electrode at a time) despite this severely limiting the repertoire of stimuli that can be applied. Methods to reliably predict the outcome of multi-electrode stimulation have not been available. Here, we demonstrate that a linear-nonlinear model accurately predicts neural responses to arbitrary patterns of stimulation using in vitro recordings from single retinal ganglion cells (RGCs) stimulated with a subretinal multi-electrode array. In the model, the stimulus is projected onto a low-dimensional subspace and then undergoes a nonlinear transformation to produce an estimate of spiking probability. The low-dimensional subspace is estimated using principal components analysis, which gives the neuron's electrical receptive field (ERF), i.e. the electrodes to which the neuron is most sensitive. Our model suggests that stimulation proportional to the ERF yields a higher efficacy given a fixed amount of power when compared to equal amplitude stimulation on up to three electrodes. We find that the model captures the responses of all the cells recorded in the study, suggesting that it will generalize to most cell types in the retina. The model is computationally efficient to evaluate and, therefore, appropriate for future real-time applications including stimulation strategies that make use of recorded neural activity to improve the stimulation strategy. PMID:27035143

  2. A Simple and Accurate Model to Predict Responses to Multi-electrode Stimulation in the Retina.

    Directory of Open Access Journals (Sweden)

    Matias I Maturana

    2016-04-01

    Full Text Available Implantable electrode arrays are widely used in therapeutic stimulation of the nervous system (e.g. cochlear, retinal, and cortical implants. Currently, most neural prostheses use serial stimulation (i.e. one electrode at a time despite this severely limiting the repertoire of stimuli that can be applied. Methods to reliably predict the outcome of multi-electrode stimulation have not been available. Here, we demonstrate that a linear-nonlinear model accurately predicts neural responses to arbitrary patterns of stimulation using in vitro recordings from single retinal ganglion cells (RGCs stimulated with a subretinal multi-electrode array. In the model, the stimulus is projected onto a low-dimensional subspace and then undergoes a nonlinear transformation to produce an estimate of spiking probability. The low-dimensional subspace is estimated using principal components analysis, which gives the neuron's electrical receptive field (ERF, i.e. the electrodes to which the neuron is most sensitive. Our model suggests that stimulation proportional to the ERF yields a higher efficacy given a fixed amount of power when compared to equal amplitude stimulation on up to three electrodes. We find that the model captures the responses of all the cells recorded in the study, suggesting that it will generalize to most cell types in the retina. The model is computationally efficient to evaluate and, therefore, appropriate for future real-time applications including stimulation strategies that make use of recorded neural activity to improve the stimulation strategy.

  3. A Simple and Accurate Model to Predict Responses to Multi-electrode Stimulation in the Retina

    Science.gov (United States)

    Maturana, Matias I.; Apollo, Nicholas V.; Hadjinicolaou, Alex E.; Garrett, David J.; Cloherty, Shaun L.; Kameneva, Tatiana; Grayden, David B.; Ibbotson, Michael R.; Meffin, Hamish

    2016-01-01

    Implantable electrode arrays are widely used in therapeutic stimulation of the nervous system (e.g. cochlear, retinal, and cortical implants). Currently, most neural prostheses use serial stimulation (i.e. one electrode at a time) despite this severely limiting the repertoire of stimuli that can be applied. Methods to reliably predict the outcome of multi-electrode stimulation have not been available. Here, we demonstrate that a linear-nonlinear model accurately predicts neural responses to arbitrary patterns of stimulation using in vitro recordings from single retinal ganglion cells (RGCs) stimulated with a subretinal multi-electrode array. In the model, the stimulus is projected onto a low-dimensional subspace and then undergoes a nonlinear transformation to produce an estimate of spiking probability. The low-dimensional subspace is estimated using principal components analysis, which gives the neuron’s electrical receptive field (ERF), i.e. the electrodes to which the neuron is most sensitive. Our model suggests that stimulation proportional to the ERF yields a higher efficacy given a fixed amount of power when compared to equal amplitude stimulation on up to three electrodes. We find that the model captures the responses of all the cells recorded in the study, suggesting that it will generalize to most cell types in the retina. The model is computationally efficient to evaluate and, therefore, appropriate for future real-time applications including stimulation strategies that make use of recorded neural activity to improve the stimulation strategy. PMID:27035143

  4. Neuropsychiatric Outcome of an Adolescent Who Received Deep Brain Stimulation for Tourette's Syndrome

    Directory of Open Access Journals (Sweden)

    S. J. Pullen

    2011-01-01

    Full Text Available This case study followed one adolescent patient who underwent bilateral deep brain stimulation of the centromedian parafascicular complex (CM-Pf for debilitating, treatment refractory Tourette's syndrome for a period of 1.5 years. Neurocognitive testing showed no significant changes between baseline and follow-up assessments. Psychiatric assessment revealed positive outcomes in overall adaptive functioning and reduction in psychotropic medication load in this patient. Furthermore, despite significant baseline psychiatric comorbidity, this patient reported no suicidal ideation following electrode implantation. Deep brain stimulation is increasingly being used in children and adolescents. This case reports on the positive neurologic and neuropsychiatric outcome of an adolescent male with bilateral CM-Pf stimulation.

  5. Synergistic effects of ethanol and cocaine on brain stimulation reward.

    OpenAIRE

    Lewis, M. J.; June, H L

    1994-01-01

    The effects of two widely abused drugs, ethanol and cocaine, were examined alone and in combination on intracranial reward processes. In agreement with previous research, higher doses of both cocaine and ethanol alone produced facilitation of behavior maintained by brain stimulation reward. Low intraperitoneal doses of ethanol and cocaine, which alone did not affect performance, were found to reduce stimulation reward threshold and modestly increase response rate. The enhancement of brain sti...

  6. Economic substitutability of electrical brain stimulation, food, and water.

    OpenAIRE

    Green, L.; Rachlin, H

    1991-01-01

    Concurrent variable-ratio schedules of electrical brain stimulation, food, and water were paired in various combinations as reinforcement of rats' lever presses. Relative prices of the concurrent reinforcers were varied by changing the ratio of the response requirements on the two levers. Economic substitutability, measured by the sensitivity of response ratio to changes in relative price, was highest with brain stimulation reinforcement of presses on both levers and lowest with food reinforc...

  7. Manganese-enhanced MR imaging of brain activation evoked by noxious peripheral electrical stimulation.

    Science.gov (United States)

    Cha, Myeounghoon; Lee, Kyuhong; Lee, Chulhyun; Cho, Jee-Hyun; Cheong, Chaejoon; Sohn, Jin-Hun; Lee, Bae Hwan

    2016-02-01

    As imaging technology develops, magnetic resonance imaging (MRI) has furthered our understanding of brain function by clarifying the anatomical structure and generating functional imaging data related to information processing in pain conditions. Recent studies have reported that manganese (Mn(2+))-enhanced MRI (MEMRI) provides valuable information about the functions of the central nervous system. The aim of this study was to identify specific brain regions activated during noxious electric stimulation using high-resolution MEMRI. Male Sprague Dawley rats were divided into three groups: naïve, sham electrical stimulation, and noxious electric stimulation. Under urethane with α-chloralose mixture anesthesia, a catheter was placed in the external carotid artery to administrate 20% mannitol and manganese chloride (25mM MnCl2). Noxious electric stimulation (2Hz, 10V) was applied to the hind paw with a needle electrode. Stimulation-induced neuronal activation was detected using 4.7-T MRI. In response to noxious electrical stimulation, remarkable Mn(2+)-enhanced signals were observed in the agranular insular cortex, auditory cortex, primary somatosensory cortex of the hind limb, and granular and dysgranular insular cortex, which correspond to sensory tactile electric stimulus to the hindpaws. These results indicate that the combination of MEMRI with activity-induced Mn(2+)-dependent contrast can delineate functional areas in the rat brain. PMID:26733299

  8. Evidence of the enhancement effect in electrical stimulation via electrode matching (L).

    Science.gov (United States)

    Goupell, Matthew J; Mostardi, Mitchell J

    2012-02-01

    The ability to match a pulsing electrode during multi-electrode stimulation through a research interface was measured in seven cochlear-implant (CI) users. Five listeners were relatively good at the task and two could not perform the task. Performance did not vary as a function of the number of electrodes or stimulation level. Performance on the matching task was not correlated to performance on an electrode-discrimination task. The listeners may have experienced the auditory enhancement effect, and this may have implications for speech recognition in noise for CI users. PMID:22352475

  9. Non-invasive brain stimulation in early rehabilitation after stroke

    OpenAIRE

    Blesneag, AV; Popa, L.; Stan, AD

    2015-01-01

    The new tendency in rehabilitation involves non-invasive tools that, if applied early after stroke, promote neurorecovery. Repetitive transcranial magnetic stimulation and transcranial direct current stimulation may correct the disruption of cortical excitability and effectively contribute to the restoration of movement and speech. The present paper analyses the results of non-invasive brain stimulation (NIBS) trials, highlighting different aspects related to the repetitive transcranial magne...

  10. Coupling BCI and cortical stimulation for brain-state-dependent stimulation: Methods for spectral estimation in the presence of stimulation after-effects

    OpenAIRE

    Armin Walter; Ander Ramos Murguialday; Niels Birbaumer; Martin Bogdan

    2012-01-01

    Brain-state-dependent stimulation combines brain-computer interfaces (BCI) and cortical stimulation into one paradigm that allows the online decoding for example of movement intention from brain signals while simultaneously applying stimulation. If the BCI decoding is performed by spectral features, stimulation after-effects such as artefacts and evoked activity present a challenge for a successful implementation of brain-state-dependent stimulation because they can impair the detection of ta...

  11. Systemic Stimulation of TLR2 Impairs Neonatal Mouse Brain Development

    OpenAIRE

    Xiaonan Du; Bobbi Fleiss; Hongfu Li; Barbara D'Angelo; Yanyan Sun; Changlian Zhu; Henrik Hagberg; Ofer Levy; Carina Mallard; Xiaoyang Wang

    2011-01-01

    Background: Inflammation is associated with perinatal brain injury but the underlying mechanisms are not completely characterized. Stimulation of Toll-like receptors (TLRs) through specific agonists induces inflammatory responses that trigger both innate and adaptive immune responses. The impact of engagement of TLR2 signaling pathways on the neonatal brain is still unclear. The aim of this study was to investigate the potential effect of a TLR2 agonist on neonatal brain development. Methodol...

  12. Diffusion Tractography in Deep Brain Stimulation Surgery: A Review

    OpenAIRE

    Calabrese, Evan

    2016-01-01

    Deep brain stimulation (DBS) is believed to exert its therapeutic effects through modulation of brain circuitry, yet conventional preoperative planning does not allow direct targeting or visualization of white matter pathways. Diffusion MRI tractography (DT) is virtually the only non-invasive method of visualizing structural connectivity in the brain, leading many to suggest its use to guide DBS targeting. DT-guided DBS not only has the potential to allow direct white matter targeting for est...

  13. Repeated BOLD-fMRI imaging of deep brain stimulation responses in rats.

    Science.gov (United States)

    Chao, Tzu-Hao Harry; Chen, Jyh-Horng; Yen, Chen-Tung

    2014-01-01

    Functional magnetic resonance imaging (fMRI) provides a picture of the global spatial activation pattern of the brain. Interest is growing regarding the application of fMRI to rodent models to investigate adult brain plasticity. To date, most rodent studies used an electrical forepaw stimulation model to acquire fMRI data, with α-chloralose as the anesthetic. However, α-chloralose is harmful to animals, and not suitable for longitudinal studies. Moreover, peripheral stimulation models enable only a limited number of brain regions to be studied. Processing between peripheral regions and the brain is multisynaptic, and renders interpretation difficult and uncertain. In the present study, we combined the medetomidine-based fMRI protocol (a noninvasive rodent fMRI protocol) with chronic implantation of an MRI-compatible stimulation electrode in the ventroposterior (VP) thalamus to repetitively sample thalamocortical responses in the rat brain. Using this model, we scanned the forebrain responses evoked by the VP stimulation repeatedly of individual rats over 1 week. Cortical BOLD responses were compared between the 2 profiles obtained at day1 and day8. We discovered reproducible frequency- and amplitude-dependent BOLD responses in the ipsilateral somatosensory cortex (S1). The S1 BOLD responses during the 2 sessions were conserved in maximal response amplitude, area size (size ratio from 0.88 to 0.91), and location (overlap ratio from 0.61 to 0.67). The present study provides a long-term chronic brain stimulation protocol for studying the plasticity of specific neural circuits in the rodent brain by BOLD-fMRI. PMID:24825464

  14. Repeated BOLD-fMRI imaging of deep brain stimulation responses in rats.

    Directory of Open Access Journals (Sweden)

    Tzu-Hao Harry Chao

    Full Text Available Functional magnetic resonance imaging (fMRI provides a picture of the global spatial activation pattern of the brain. Interest is growing regarding the application of fMRI to rodent models to investigate adult brain plasticity. To date, most rodent studies used an electrical forepaw stimulation model to acquire fMRI data, with α-chloralose as the anesthetic. However, α-chloralose is harmful to animals, and not suitable for longitudinal studies. Moreover, peripheral stimulation models enable only a limited number of brain regions to be studied. Processing between peripheral regions and the brain is multisynaptic, and renders interpretation difficult and uncertain. In the present study, we combined the medetomidine-based fMRI protocol (a noninvasive rodent fMRI protocol with chronic implantation of an MRI-compatible stimulation electrode in the ventroposterior (VP thalamus to repetitively sample thalamocortical responses in the rat brain. Using this model, we scanned the forebrain responses evoked by the VP stimulation repeatedly of individual rats over 1 week. Cortical BOLD responses were compared between the 2 profiles obtained at day1 and day8. We discovered reproducible frequency- and amplitude-dependent BOLD responses in the ipsilateral somatosensory cortex (S1. The S1 BOLD responses during the 2 sessions were conserved in maximal response amplitude, area size (size ratio from 0.88 to 0.91, and location (overlap ratio from 0.61 to 0.67. The present study provides a long-term chronic brain stimulation protocol for studying the plasticity of specific neural circuits in the rodent brain by BOLD-fMRI.

  15. Vascular changes caused by deep brain stimulation using double-dose gadolinium-enhanced brain MRI

    Institute of Scientific and Technical Information of China (English)

    Byeong Sam Choi; Yong Hwan Kim; Sang Ryong Jeon

    2014-01-01

    We retrospectively analyzed the clinical data of 32 patients with medically intractable idiopathic Parkinson’s disease who had undergone staged bilateral deep brain stimulation of the subtha-lamic nuclei from January 2007 to May 2011. The vascularture of the patients who received two deep brain stimulations was detected using double-dose gadolinium-enhanced brain MRI. The dimensions of straight sinus, superior sagittal sinus, ipsilateral internal cerebral vein in the tha-lamic branch and ipsilateral anterior caudate vein were reduced. These ifndings demonstrate that bilateral deep brain stimulation of the subthalamic nuclei affects cerebral venous blood lfow.

  16. Brain stimulation: Neuromodulation as a potential treatment for motor recovery following traumatic brain injury.

    Science.gov (United States)

    Clayton, E; Kinley-Cooper, S K; Weber, R A; Adkins, D L

    2016-06-01

    There is growing evidence that electrical and magnetic brain stimulation can improve motor function and motor learning following brain damage. Rodent and primate studies have strongly demonstrated that combining cortical stimulation (CS) with skilled motor rehabilitative training enhances functional motor recovery following stroke. Brain stimulation following traumatic brain injury (TBI) is less well studied, but early pre-clinical and human pilot studies suggest that it is a promising treatment for TBI-induced motor impairments as well. This review will first discuss the evidence supporting brain stimulation efficacy derived from the stroke research field as proof of principle and then will review the few studies exploring neuromodulation in experimental TBI studies. This article is part of a Special Issue entitled SI:Brain injury and recovery. PMID:26855256

  17. Capacitor electrode stimulates nerve or muscle without oxidation-reduction reactions.

    Science.gov (United States)

    Guyton, D L; Hambrecht, F T

    1973-07-01

    Porous tantalum disks, available as "slugs" from the capacitor industry, have large available surface area and a thin insulating coating of tantalum pentoxide. When implanted, they fill with extracellular fluid and operate as capacitor-stimulating electrodes having high capacitance per unit volume. Capable of stimulating excitable tissute without generating electrochemical by-products, these electrodes should provide a safer interface between neural prosthetic devices and human tissue. PMID:4197450

  18. A multi-pad electrode based functional electrical stimulation system for restoration of grasp

    Directory of Open Access Journals (Sweden)

    Malešević Nebojša M

    2012-09-01

    Full Text Available Abstract Background Functional electrical stimulation (FES applied via transcutaneous electrodes is a common rehabilitation technique for assisting grasp in patients with central nervous system lesions. To improve the stimulation effectiveness of conventional FES, we introduce multi-pad electrodes and a new stimulation paradigm. Methods The new FES system comprises an electrode composed of small pads that can be activated individually. This electrode allows the targeting of motoneurons that activate synergistic muscles and produce a functional movement. The new stimulation paradigm allows asynchronous activation of motoneurons and provides controlled spatial distribution of the electrical charge that is delivered to the motoneurons. We developed an automated technique for the determination of the preferred electrode based on a cost function that considers the required movement of the fingers and the stabilization of the wrist joint. The data used within the cost function come from a sensorized garment that is easy to implement and does not require calibration. The design of the system also includes the possibility for fine-tuning and adaptation with a manually controllable interface. Results The device was tested on three stroke patients. The results show that the multi-pad electrodes provide the desired level of selectivity and can be used for generating a functional grasp. The results also show that the procedure, when performed on a specific user, results in the preferred electrode configuration characteristics for that patient. The findings from this study are of importance for the application of transcutaneous stimulation in the clinical and home environments.

  19. Electrochemical properties of titanium nitride nerve stimulation electrodes: An in vitro and in vivo study

    Directory of Open Access Journals (Sweden)

    Suzan eMeijs

    2015-08-01

    Full Text Available The in vivo electrochemical behavior of titanium nitride (TiN nerve stimulation electrodes was compared to their in vitro behavior for a period of 90 days. Ten electrodes were implanted in two Göttingen minipigs. Four of these were used for electrical stimulation and electrochemical measurements. Five electrodes were kept in Ringer’s solution at 37.5 °C, of which four were used for electrical stimulation and electrochemical measurements. The voltage transients measured in vivo were 13 times greater than in vitro at implantation and they continued to increase with time. The electrochemical properties in vivo and the tissue resistance (Rtissue followed a similar trend with time. There was no consistent significant difference between the electrochemical properties of the in vivo and in vitro electrodes after the implanted period. The differences between the in vivo and in vitro electrodes during the implanted period show that the evaluation of electrochemical performance of implantable stimulation electrodes cannot be substituted with in vitro measurements. After the implanted period, however, the performance of the in vivo and in vitro electrodes in saline was similar. In addition, the changes observed over time during the post-implantation period regarding the electrochemical properties of the in vivo electrodes and Rtissue were similar, which indicates that these changes are due to the foreign body response to implantation.

  20. Uncovering the mechanism(s) of deep brain stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Li Gang; Yu Chao; Lin Ling; Lu, Stephen C-Y [Inspiring Technical Laboratory, College of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072 (China)

    2005-01-01

    Deep brain stimulators, often called 'pacemakers for the brain', are implantable devices which continuously deliver impulse stimulation to specific targeted nuclei of deep brain structure, namely deep brain stimulation (DBS). To date, deep brain stimulation (DBS) is the most effective clinical technique for the treatment of several medically refractory movement disorders (e.g., Parkinson's disease, essential tremor, and dystonia). In addition, new clinical applications of DBS for other neurologic and psychiatric disorders (e.g., epilepsy and obsessive-compulsive disorder) have been put forward. Although DBS has been effective in the treatment of movement disorders and is rapidly being explored for the treatment of other neurologic disorders, the scientific understanding of its mechanisms of action remains unclear and continues to be debated in the scientific community. Optimization of DBS technology for present and future therapeutic applications will depend on identification of the therapeutic mechanism(s) of action. The goal of this review is to address our present knowledge of the effects of high-frequency stimulation within the central nervous system and comment on the functional implications of this knowledge for uncovering the mechanism(s) of DBS.

  1. Uncovering the mechanism(s) of deep brain stimulation

    Science.gov (United States)

    Gang, Li; Chao, Yu; Ling, Lin; C-Y Lu, Stephen

    2005-01-01

    Deep brain stimulators, often called `pacemakers for the brain', are implantable devices which continuously deliver impulse stimulation to specific targeted nuclei of deep brain structure, namely deep brain stimulation (DBS). To date, deep brain stimulation (DBS) is the most effective clinical technique for the treatment of several medically refractory movement disorders (e.g., Parkinson's disease, essential tremor, and dystonia). In addition, new clinical applications of DBS for other neurologic and psychiatric disorders (e.g., epilepsy and obsessive-compulsive disorder) have been put forward. Although DBS has been effective in the treatment of movement disorders and is rapidly being explored for the treatment of other neurologic disorders, the scientific understanding of its mechanisms of action remains unclear and continues to be debated in the scientific community. Optimization of DBS technology for present and future therapeutic applications will depend on identification of the therapeutic mechanism(s) of action. The goal of this review is to address our present knowledge of the effects of high-frequency stimulation within the central nervous system and comment on the functional implications of this knowledge for uncovering the mechanism(s) of DBS.

  2. Uncovering the mechanism(s) of deep brain stimulation

    International Nuclear Information System (INIS)

    Deep brain stimulators, often called 'pacemakers for the brain', are implantable devices which continuously deliver impulse stimulation to specific targeted nuclei of deep brain structure, namely deep brain stimulation (DBS). To date, deep brain stimulation (DBS) is the most effective clinical technique for the treatment of several medically refractory movement disorders (e.g., Parkinson's disease, essential tremor, and dystonia). In addition, new clinical applications of DBS for other neurologic and psychiatric disorders (e.g., epilepsy and obsessive-compulsive disorder) have been put forward. Although DBS has been effective in the treatment of movement disorders and is rapidly being explored for the treatment of other neurologic disorders, the scientific understanding of its mechanisms of action remains unclear and continues to be debated in the scientific community. Optimization of DBS technology for present and future therapeutic applications will depend on identification of the therapeutic mechanism(s) of action. The goal of this review is to address our present knowledge of the effects of high-frequency stimulation within the central nervous system and comment on the functional implications of this knowledge for uncovering the mechanism(s) of DBS

  3. Coupling brain-machine interfaces with cortical stimulation for brain-state dependent stimulation: enhancing motor cortex excitability for neurorehabilitation

    Directory of Open Access Journals (Sweden)

    Alireza Gharabaghi

    2014-03-01

    Full Text Available Motor recovery after stroke is an unsolved challenge despite intensive rehabilitation training programs. Brain stimulation techniques have been explored in addition to traditional rehabilitation training to increase the excitability of the stimulated motor cortex. This modulation of cortical excitability augments the response to afferent input during motor exercises, thereby enhancing skilled motor learning by long-term potentiation-like plasticity. Recent approaches examined brain stimulation applied concurrently with voluntary movements to induce more specific use-dependent neural plasticity during motor training for neurorehabilitation. Unfortunately, such approaches are not applicable for the many severely affected stroke patients lacking residual hand function. These patients require novel activity-dependent stimulation paradigms based on intrinsic brain activity. Here, we report on such brain state-dependent stimulation (BSDS combined with haptic feedback provided by a robotic hand orthosis. Transcranial magnetic stimulation of the motor cortex and haptic feedback to the hand were controlled by sensorimotor desynchronization during motor-imagery and applied within a brain-machine interface environment in one healthy subject and one patient with severe hand paresis in the chronic phase after stroke. BSDS significantly increased the excitability of the stimulated motor cortex in both healthy and post-stroke conditions, an effect not observed in non-BSDS protocols. This feasibility study suggests that closing the loop between intrinsic brain state, cortical stimulation and haptic feedback provides a novel neurorehabilitation strategy for stroke patients lacking residual hand function, a proposal that warrants further investigation in a larger cohort of stroke patients.

  4. Anaesthetic management of shoulder arthroscopic repair in Parkinson′s disease with deep brain stimulator

    Directory of Open Access Journals (Sweden)

    Ranju Gandhi

    2014-01-01

    Full Text Available We describe the anaesthetic management of arthroscopic repair for complete rotator cuff tear of shoulder in a 59-year-old female with Parkinson′s disease (PD with deep brain stimulator (DBS using a combination of general anaesthesia with interscalene approach to brachial plexus block. The DBS consists of implanted electrodes in the brain connected to the implantable pulse generator (IPG normally placed in the anterior chest wall subcutaneously. It can be programmed externally from a hand-held device placed directly over the battery stimulator unit. In our patient, IPG with its leads was located in close vicinity of the operative site with potential for DBS malfunction. Implications of DBS in a patient with PD for shoulder arthroscopy for anaesthesiologist are discussed along with a brief review of DBS.

  5. Coupling BCI and cortical stimulation for brain-state-dependent stimulation: methods for spectral estimation in the presence of stimulation after-effects

    OpenAIRE

    Walter, Armin; Murguialday, Ander R.; Rosenstiel, Wolfgang; Birbaumer, Niels; Bogdan, Martin

    2012-01-01

    Brain-state-dependent stimulation (BSDS) combines brain-computer interfaces (BCIs) and cortical stimulation into one paradigm that allows the online decoding for example of movement intention from brain signals while simultaneously applying stimulation. If the BCI decoding is performed by spectral features, stimulation after-effects such as artefacts and evoked activity present a challenge for a successful implementation of BSDS because they can impair the detection of targeted brain states. ...

  6. Deep brain stimulation affects conditioned and unconditioned anxiety in different brain areas.

    Science.gov (United States)

    van Dijk, A; Klanker, M; van Oorschot, N; Post, R; Hamelink, R; Feenstra, M G P; Denys, D

    2013-01-01

    Deep brain stimulation (DBS) of the nucleus accumbens (NAc) has proven to be an effective treatment for therapy refractory obsessive-compulsive disorder. Clinical observations show that anxiety symptoms decrease rapidly following DBS. As in clinical studies different regions are targeted, it is of principal interest to understand which brain area is responsible for the anxiolytic effect and whether high-frequency stimulation of different areas differentially affect unconditioned (innate) and conditioned (learned) anxiety. In this study, we examined the effect of stimulation in five brain areas in rats (NAc core and shell, bed nucleus of the stria terminalis (BNST), internal capsule (IC) and the ventral medial caudate nucleus (CAU)). The elevated plus maze was used to test the effect of stimulation on unconditioned anxiety, the Vogel conflict test for conditioned anxiety, and an activity test for general locomotor behaviour. We found different anxiolytic effects of stimulation in the five target areas. Stimulation of the CAU decreased both conditioned and unconditioned anxiety, while stimulation of the IC uniquely reduced conditioned anxiety. Remarkably, neither the accumbens nor the BNST stimulation affected conditioned or unconditioned anxiety. Locomotor activity increased with NAc core stimulation but decreased with the BNST. These findings suggest that (1) DBS may have a differential effect on unconditioned and conditioned anxiety depending on the stimulation area, and that (2) stimulation of the IC exclusively reduces conditioned anxiety. This suggests that the anxiolytic effects of DBS seen in OCD patients may not be induced by stimulation of the NAc, but rather by the IC. PMID:23900312

  7. Deep Brain Stimulation for Essential Vocal Tremor: A Technical Report.

    Science.gov (United States)

    Ho, Allen L; Choudhri, Omar; Sung, C Kwang; DiRenzo, Elizabeth E; Halpern, Casey H

    2015-03-01

    Essential vocal tremor (EVT) is the presence of a tremulous voice that is commonly associated with essential tremor. Patients with EVT often report a necessary increase in vocal effort that significantly worsens with stress and anxiety and can significantly impact quality of life despite optimal medical and behavioral treatment options. Deep brain stimulation (DBS) has been proposed as an effective therapy for vocal tremor, but very few studies exist in the literature that comprehensively evaluate the efficacy of DBS for specifically addressing EVT. We present a technical report on our multidisciplinary, comprehensive operative methodology for treatment of EVT with frameless, awake deep brain stimulation (DBS). PMID:26180680

  8. Optimum electrode geometry for spinal cord stimulation: the narrow bipole and tripole.

    Science.gov (United States)

    Holsheimer, J; Wesselink, W A

    1997-09-01

    A computer model is used to calculate the optimum geometry of an epidural electrode, consisting of a longitudinal contact array, for spinal cord stimulation in the management of chronic, intractable pain. 3D models of the spinal area are used for the computation of stimulation induced fields, and a cable model of myelinated nerve fibre is used for the calculation of the threshold stimulus to excite large dorsal column and dorsal root fibres. The criteria for the geometry of the longitudinal contact array are: a low threshold for the stimulation of dorsal column fibres compared with dorsal root fibres; and a low stimulation voltage (and current). For both percutaneous and laminectomy electrodes, the contact length should be approximately 1.5 mm, and the optimum contact separation, as determined by the computer model, is 2-2.5 mm. The contacts for a laminectomy electrode should be approximately 4 mm wide. This electrode geometry is applicable to all spinal levels where the dorsal columns can be stimulated (C1-2 down to L1). The stimulating electrode should preferably be used as a tripole with one (central) cathode. PMID:9374053

  9. Analyzing the tradeoff between electrical complexity and accuracy in patient-specific computational models of deep brain stimulation

    Science.gov (United States)

    Howell, Bryan; McIntyre, Cameron C.

    2016-06-01

    Objective. Deep brain stimulation (DBS) is an adjunctive therapy that is effective in treating movement disorders and shows promise for treating psychiatric disorders. Computational models of DBS have begun to be utilized as tools to optimize the therapy. Despite advancements in the anatomical accuracy of these models, there is still uncertainty as to what level of electrical complexity is adequate for modeling the electric field in the brain and the subsequent neural response to the stimulation. Approach. We used magnetic resonance images to create an image-based computational model of subthalamic DBS. The complexity of the volume conductor model was increased by incrementally including heterogeneity, anisotropy, and dielectric dispersion in the electrical properties of the brain. We quantified changes in the load of the electrode, the electric potential distribution, and stimulation thresholds of descending corticofugal (DCF) axon models. Main results. Incorporation of heterogeneity altered the electric potentials and subsequent stimulation thresholds, but to a lesser degree than incorporation of anisotropy. Additionally, the results were sensitive to the choice of method for defining anisotropy, with stimulation thresholds of DCF axons changing by as much as 190%. Typical approaches for defining anisotropy underestimate the expected load of the stimulation electrode, which led to underestimation of the extent of stimulation. More accurate predictions of the electrode load were achieved with alternative approaches for defining anisotropy. The effects of dielectric dispersion were small compared to the effects of heterogeneity and anisotropy. Significance. The results of this study help delineate the level of detail that is required to accurately model electric fields generated by DBS electrodes.

  10. An energy-efficient, adiabatic electrode stimulator with inductive energy recycling and feedback current regulation.

    Science.gov (United States)

    Arfin, Scott K; Sarpeshkar, Rahul

    2012-02-01

    In this paper, we present a novel energy-efficient electrode stimulator. Our stimulator uses inductive storage and recycling of energy in a dynamic power supply. This supply drives an electrode in an adiabatic fashion such that energy consumption is minimized. It also utilizes a shunt current-sensor to monitor and regulate the current through the electrode via feedback, thus enabling flexible and safe stimulation. Since there are no explicit current sources or current limiters, wasteful energy dissipation across such elements is naturally avoided. The dynamic power supply allows efficient transfer of energy both to and from the electrode and is based on a DC-DC converter topology that we use in a bidirectional fashion in forward-buck or reverse-boost modes. In an exemplary electrode implementation intended for neural stimulation, we show how the stimulator combines the efficiency of voltage control and the safety and accuracy of current control in a single low-power integrated-circuit built in a standard .35 μm CMOS process. This stimulator achieves a 2x-3x reduction in energy consumption as compared to a conventional current-source-based stimulator operating from a fixed power supply. We perform a theoretical analysis of the energy efficiency that is in accord with experimental measurements. This theoretical analysis reveals that further improvements in energy efficiency may be achievable with better implementations in the future. Our electrode stimulator could be widely useful for neural, cardiac, retinal, cochlear, muscular and other biomedical implants where low power operation is important. PMID:23852740

  11. Fascicular selectivity in transverse stimulation with a nerve cuff electrode: a theoretical approach.

    Science.gov (United States)

    Deurloo, Kirsten E I; Holsheimer, Jan; Bergveld, Piet

    2003-10-01

    The performance of cathode-anode configurations in a cuff electrode to stimulate a single fascicle in a nerve trunk has been investigated theoretically. A three-dimensional volume conductor model of a nerve trunk with four fascicles in a cuff electrode and a model of myelinated nerve fiber stimulation were used to calculate the recruitment of 15 m fibers in each fascicle. The effect of a monopole, a transverse bipole (anode opposite the cathode), and a narrow transverse tripole (guarded cathode) in selectively stimulating 15 m fibers in each fascicle has been quantified and presented as recruitment curves. It is predicted that selective fascicle stimulation is advanced most by stimulation with a bipole in a plane perpendicular to the axis of the nerve trunk. Monopoles and conventional longitudinal tripoles perform less well, as does a longitudinal tripole with an additional "steering" anode. Apart from transverse bipolar stimulation an additional anode may be used to maximally fit the area of excitation to the topography of the fascicle to be recruited. As compared to monopolar and longitudinal tripolar stimulation, the slope of the recruitment curves in transverse bipolar stimulation is reduced considerably, thus allowing improved fine tuning of nerve (and thus force) recruitment. Another advantage of this method is a minimal number of cable connections to the cuff electrode. The cost of the improved selectivity is an increased stimulation current. PMID:22151073

  12. Role of sound stimulation in reprogramming brain connectivity

    Indian Academy of Sciences (India)

    Sraboni Chaudhury; Tapas C Nag; Suman Jain; Shashi Wadhwa

    2013-09-01

    Sensory stimulation has a critical role to play in the development of an individual. Environmental factors tend to modify the inputs received by the sensory pathway. The developing brain is most vulnerable to these alterations and interacts with the environment to modify its neural circuitry. In addition to other sensory stimuli, auditory stimulation can also act as external stimuli to provide enrichment during the perinatal period. There is evidence that suggests that enriched environment in the form of auditory stimulation can play a substantial role in modulating plasticity during the prenatal period. This review focuses on the emerging role of prenatal auditory stimulation in the development of higher brain functions such as learning and memory in birds and mammals. The molecular mechanisms of various changes in the hippocampus following sound stimulation to effect neurogenesis, learning and memory are described. Sound stimulation can also modify neural connectivity in the early postnatal life to enhance higher cognitive function or even repair the secondary damages in various neurological and psychiatric disorders. Thus, it becomes imperative to examine in detail the possible ameliorating effects of prenatal sound stimulation in existing animal models of various psychiatric disorders, such as autism.

  13. Focusing and targeting of magnetic brain stimulation using multiple coils.

    Science.gov (United States)

    Ruohonen, J; Ilmoniemi, R J

    1998-05-01

    Neurones can be excited by an externally applied time-varying electromagnetic field. Focused magnetic brain stimulation is attained using multiple small coils instead of one large coil, the resultant induced electric field being a superposition of the fields from each coil. In multichannel magnetic brain stimulation, partial cancellation of fields from individual coils provides a significant improvement in the focusing of the stimulating field, and independent coil channels allow targeting of the stimuli on a given spot without moving the coils. The problem of shaping the stimulating field in multichannel stimulation is analysed, and a method is derived that yields the driving currents required to induce a field with a user-defined shape. The formulation makes use of lead fields and minimum-norm estimation from magneto-encephalography. Using these methods, some properties of multichannel coil arrays are examined. Computer-assisted multichannel stimulation of the cortex will enable several new studies, including quick determination of the cortical regions, the stimulation of which disrupts cortical processing required by a task. PMID:9747568

  14. Clinical utility of brain stimulation modalities following traumatic brain injury: current evidence

    Directory of Open Access Journals (Sweden)

    Li S

    2015-06-01

    Full Text Available Shasha Li,1,2 Ana Luiza Zaninotto,2,3 Iuri Santana Neville,4 Wellingson Silva Paiva,4 Danuza Nunn,2 Felipe Fregni21Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 2Spaulding Neuromodulation Center, Harvard Medical School, Boston, MA, USA; 3Division of Psychology, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil; 4Division of Neurosurgery, University of São Paulo Medical School, São Paulo, São Paulo, BrazilAbstract: Traumatic brain injury (TBI remains the main cause of disability and a major public health problem worldwide. This review focuses on the neurophysiology of TBI, and the rationale and current state of evidence of clinical application of brain stimulation to promote TBI recovery, particularly on consciousness, cognitive function, motor impairments, and psychiatric conditions. We discuss the mechanisms of different brain stimulation techniques including major noninvasive and invasive stimulations. Thus far, most noninvasive brain stimulation interventions have been nontargeted and focused on the chronic phase of recovery after TBI. In the acute stages, there is limited available evidence of the efficacy and safety of brain stimulation to improve functional outcomes. Comparing the studies across different techniques, transcranial direct current stimulation is the intervention that currently has the higher number of properly designed clinical trials, though total number is still small. We recognize the need for larger studies with target neuroplasticity modulation to fully explore the benefits of brain stimulation to effect TBI recovery during different stages of recovery.Keywords: traumatic brain injury, brain stimulation, neuroplasticity

  15. The Safety of Using Body-Transmit MRI in Patients with Implanted Deep Brain Stimulation Devices

    OpenAIRE

    Joshua Kahan; Anastasia Papadaki; Mark White; Laura Mancini; Tarek Yousry; Ludvic Zrinzo; Patricia Limousin; Marwan Hariz; Tom Foltynie; John Thornton

    2015-01-01

    Background Deep brain stimulation (DBS) is an established treatment for patients with movement disorders. Patients receiving chronic DBS provide a unique opportunity to explore the underlying mechanisms of DBS using functional MRI. It has been shown that the main safety concern with MRI in these patients is heating at the electrode tips – which can be minimised with strict adherence to a supervised acquisition protocol using a head-transmit/receive coil at 1.5T. MRI using the body-transmit co...

  16. Resting-state networks link invasive and noninvasive brain stimulation across diverse psychiatric and neurological diseases

    OpenAIRE

    Fox, Michael D.; Buckner, Randy L.; Liu, Hesheng; Chakravarty, M. Mallar; Lozano, Andres M.; Pascual-Leone, Alvaro

    2014-01-01

    Brain stimulation is a powerful treatment for an increasing number of psychiatric and neurological diseases, but it is unclear why certain stimulation sites work or where in the brain is the best place to stimulate to treat a given patient or disease. We found that although different types of brain stimulation are applied in different locations, targets used to treat the same disease most often are nodes in the same brain network. These results suggest that brain networks might be used to und...

  17. Noninvasive brain stimulation in the study of the human visual system

    OpenAIRE

    Halko, Mark; Eldaief, Mark C.; Pascual-Leone, Alvaro

    2013-01-01

    There are currently two techniques to manipulate brain function non-invasively: transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). These brain stimulation techniques work to cause long-term change within the brain. We have been combining noninvasive brain stimulation with functional magnetic resonance imaging (fMRI) to investigate the plasticity of brain networks. When fMRI is used as an outcome measure, it is possible to identify the specificity of tD...

  18. Using Brain Stimulation to Disentangle Neural Correlates of Conscious Vision

    Directory of Open Access Journals (Sweden)

    TomAlexanderde Graaf

    2014-09-01

    Full Text Available Research into the neural correlates of consciousness (NCCs has blossomed, due to the advent of new and increasingly sophisticated brain research tools. Neuroimaging has uncovered a variety of brain processes that relate to conscious perception, obtained in a range of experimental paradigms. But methods such as fMRI or EEG do not always afford inference on the role these brain processes play in conscious vision. Such empirical neural correlates of consciousness could reflect neural prerequisites, neural consequences, or neural substrates of a conscious experience. Here, we take a closer look at the use of non-invasive brain stimulation (NIBS techniques in this context. We discuss and review how NIBS methodology can enlighten our understanding of brain mechanisms underlying conscious vision by disentangling the empirical neural correlates of consciousness.

  19. Complications of deep brain stimulation surgery.

    Science.gov (United States)

    Beric, A; Kelly, P J; Rezai, A; Sterio, D; Mogilner, A; Zonenshayn, M; Kopell, B

    2001-01-01

    Although technological advances have reduced device-related complications, DBS surgery still carries a significant risk of transient and permanent complications. We report our experience in 86 patients and 149 DBS implants. Patients with Parkinson's disease, essential tremor and dystonia were treated. There were 8 perioperative, 8 postoperative, 9 hardware-related complications and 4 stimulation-induced side effects. Only 5 patients (6%) sustained some persistent neurological sequelae, however, 26 of the 86 patients undergoing 149 DBS implants in this series experienced some untoward event with the procedure. Although there were no fatalities or permanent severe disabilities encountered, it is important to extend the informed consent to include all potential complications. PMID:12378060

  20. Localisation of brain functions : stimuling brain activity and source reconstruction for classification/

    OpenAIRE

    Noirhomme, Quentin

    2006-01-01

    A key issue in understanding how the brain functions is the ability to correlate functional information with anatomical localisation. Functional information can be provided by a variety of techniques like positron emission tomography (PET), functional MRI (fMRI), electroencephalography (EEG), magnetoencephalography (MEG) or transcranial magnetic stimulation (TMS). All these methods provide different, but complementary, information about the functional areas of the brain. ...

  1. Quasi-monopolar stimulation: a novel electrode design configuration for performance optimization of a retinal neuroprosthesis.

    Directory of Open Access Journals (Sweden)

    Gita Khalili Moghadam

    Full Text Available In retinal neuroprostheses, spatial interaction between electric fields from various electrodes - electric crosstalk - may occur in multielectrode arrays during simultaneous stimulation of the retina. Depending on the electrode design and placement, this crosstalk can either enhance or degrade the functional characteristics of a visual prosthesis. To optimize the device performance, a balance must be satisfied between the constructive interference of crosstalk on dynamic range and power consumption and its negative effect on artificial visual acuity. In the present computational modeling study, we have examined the trade-off in these positive and negative effects using a range of currently available electrode array configurations, compared to a recently proposed stimulation strategy - the quasi monopolar (QMP configuration - in which the return current is shared between local bipolar guards and a distant monopolar electrode. We evaluate the performance of the QMP configuration with respect to the implantation site and electrode geometry parameters. Our simulation results demonstrate that the beneficial effects of QMP are only significant at electrode-to-cell distances greater than the electrode dimensions. Possessing a relatively lower activation threshold, QMP was found to be superior to the bipolar configuration in terms of providing a relatively higher visual acuity. However, the threshold for QMP was more sensitive to the topological location of the electrode in the array, which may need to be considered when programming the manner in which electrode are simultaneously activated. This drawback can be offset with a wider dynamic range and lower power consumption of QMP. Furthermore, the ratio of monopolar return current to total return can be used to adjust the functional performance of QMP for a given implantation site and electrode parameters. We conclude that the QMP configuration can be used to improve visual information-to-stimulation

  2. Electric field calculations in brain stimulation based on finite elements

    DEFF Research Database (Denmark)

    Windhoff, Mirko; Opitz, Alexander; Thielscher, Axel

    2013-01-01

    The need for realistic electric field calculations in human noninvasive brain stimulation is undisputed to more accurately determine the affected brain areas. However, using numerical techniques such as the finite element method (FEM) is methodologically complex, starting with the creation...... high-quality head models from magnetic resonance images and their usage in subsequent field calculations based on the FEM. The pipeline starts by extracting the borders between skin, skull, cerebrospinal fluid, gray and white matter. The quality of the resulting surfaces is subsequently improved...... the successful usage of the pipeline in six subjects, including field calculations for transcranial magnetic stimulation and transcranial direct current stimulation. The quality of the head volume meshes is validated both in terms of capturing the underlying anatomy and of the well-shapedness of the mesh...

  3. Chaotic desynchronization as the therapeutic mechanism of deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Charles J Wilson

    2011-06-01

    Full Text Available High frequency deep-brain stimulation of the subthalamic nucleus (DBS relieves many of the symptoms of Parkinson's disease in humans and animal models. Although the treatment has seen widespread use, its therapeutic mechanism remains paradoxical. The subthalamic nucleus is excitatory, so its stimulation at rates higher than its normal firing rate should worsen the disease by increasing subthalamic excitation of the globus pallidus. The therapeutic effectiveness of DBS is also frequency and intensity sensitive, and the stimulation must be periodic; aperiodic stimulation at the same mean rate is ineffective. These requirements are not adequately explained by existing models, whether based on firing rate changes or on reduced bursting. Here we report modeling studies suggesting that high frequency periodic excitation of the subthalamic nucleus may act by desynchronizing the firing of neurons in the globus pallidus, rather than by changing the firing rate or pattern of individual cells. Globus pallidus neurons are normally desynchronized, but their activity becomes correlated in Parkinson's disease. Periodic stimulation may induce chaotic desynchronization by interacting with the intrinsic oscillatory mechanism of globus pallidus neurons. Our modeling results suggest a mechanism of action of deep brain stimulation and a pathophysiology of Parkinsonism in which synchrony, rather than firing rate, is the critical pathological feature.

  4. Electrical stimulation with multichannel electrodes in deaf patients.

    Science.gov (United States)

    Burian, K; Hochmair, E; Hochmair-Desoyer, I; Lessel, M R

    1980-01-01

    Design and function of a 6- or 8-channel electrode assembly, which was introduced through the round window into the scala tympani, are described. Two different receiver systems, a more simple one with reed contacts and a more complex one in hybrid technology, are also described. Signal and energy are delivered transcutaneously via inductively coupled coils. The results of the electrical tests are described and discussed. PMID:6892764

  5. Effects of different three-dimensional electrodes on epiretinal electrical stimulation by modeling analysis

    OpenAIRE

    Cao, Xun; Sui, Xiaohong; Lyu, Qing; Li, Liming; Chai, Xinyu

    2015-01-01

    Background Epiretinal prostheses have been greatly successful in helping restore the vision of patients blinded by retinal degenerative diseases. The design of stimulating electrodes plays a crucial role in the performance of epiretinal prostheses. The objective of this study was to investigate, through computational modeling analysis, the effects on the excitation of retinal ganglion cells (RGCs) when different three-dimensional (3-D) electrodes were placed in the epiretinal space. Methods 3...

  6. Binaural release from masking with single- and multi-electrode stimulation in children with cochlear implants.

    Science.gov (United States)

    Todd, Ann E; Goupell, Matthew J; Litovsky, Ruth Y

    2016-07-01

    Cochlear implants (CIs) provide children with access to speech information from a young age. Despite bilateral cochlear implantation becoming common, use of spatial cues in free field is smaller than in normal-hearing children. Clinically fit CIs are not synchronized across the ears; thus binaural experiments must utilize research processors that can control binaural cues with precision. Research to date has used single pairs of electrodes, which is insufficient for representing speech. Little is known about how children with bilateral CIs process binaural information with multi-electrode stimulation. Toward the goal of improving binaural unmasking of speech, this study evaluated binaural unmasking with multi- and single-electrode stimulation. Results showed that performance with multi-electrode stimulation was similar to the best performance with single-electrode stimulation. This was similar to the pattern of performance shown by normal-hearing adults when presented an acoustic CI simulation. Diotic and dichotic signal detection thresholds of the children with CIs were similar to those of normal-hearing children listening to a CI simulation. The magnitude of binaural unmasking was not related to whether the children with CIs had good interaural time difference sensitivity. Results support the potential for benefits from binaural hearing and speech unmasking in children with bilateral CIs. PMID:27475132

  7. A new brain stimulation method: Noninvasive transcranial magneto–acoustical stimulation

    Science.gov (United States)

    Yuan, Yi; Chen, Yu-Dong; Li, Xiao-Li

    2016-08-01

    We investigate transcranial magneto–acoustical stimulation (TMAS) for noninvasive brain neuromodulation in vivo. TMAS as a novel technique uses an ultrasound wave to induce an electric current in the brain tissue in the static magnetic field. It has the advantage of high spatial resolution and penetration depth. The mechanism of TMAS onto a neuron is analyzed by combining the TMAS principle and Hodgkin–Huxley neuron model. The anesthetized rats are stimulated by TMAS, resulting in the local field potentials which are recorded and analyzed. The simulation results show that TMAS can induce neuronal action potential. The experimental results indicate that TMAS can not only increase the amplitude of local field potentials but also enhance the effect of focused ultrasound stimulation on the neuromodulation. In summary, TMAS can accomplish brain neuromodulation, suggesting a potentially powerful noninvasive stimulation method to interfere with brain rhythms for diagnostic and therapeutic purposes. Project supported by the National Natural Science Foundation of China (Grant Nos. 61503321 and 61273063) and the Natural Science Foundation of Hebei Province, China (Grant No. F2014203161).

  8. Conformable actively multiplexed high-density surface electrode array for brain interfacing

    Science.gov (United States)

    Rogers, John; Kim, Dae-Hyeong; Litt, Brian; Viventi, Jonathan

    2015-01-13

    Provided are methods and devices for interfacing with brain tissue, specifically for monitoring and/or actuation of spatio-temporal electrical waveforms. The device is conformable having a high electrode density and high spatial and temporal resolution. A conformable substrate supports a conformable electronic circuit and a barrier layer. Electrodes are positioned to provide electrical contact with a brain tissue. A controller monitors or actuates the electrodes, thereby interfacing with the brain tissue. In an aspect, methods are provided to monitor or actuate spatio-temporal electrical waveform over large brain surface areas by any of the devices disclosed herein.

  9. The Present Indication and Future of Deep Brain Stimulation

    OpenAIRE

    Sugiyama, Kenji; Nozaki, Takao; ASAKAWA, Tetsuya; KOIZUMI, SHINICHIRO; Saitoh, Osamu; Namba, Hiroki

    2015-01-01

    The use of electrical stimulation to treat pain in human disease dates back to ancient Rome or Greece. Modern deep brain stimulation (DBS) was initially applied for pain treatment in the 1960s, and was later used to treat movement disorders in the 1990s. After recognition of DBS as a therapy for central nervous system (CNS) circuit disorders, DBS use showed drastic increase in terms of adaptability to disease and the patient’s population. More than 100,000 patients have received DBS therapy w...

  10. [Shining light on translational research in deep brain stimulation].

    Science.gov (United States)

    Lüscher, Christian; Davoine, Elise; Bellone, Carmilla

    2015-04-29

    For the last decade, optogenetics has revolutionised the neurosciences by enabling an unprecedented characterisation of the circuits involved in brain diseases, in particular addiction, depression, and obsessive compulsive disorders (OCD) and other anxiety disorders. Recently, the technique has also been used to propose blueprints for novel treatments of these diseases. For many reasons, optogenetics cannot be applied to humans applications anytime soon; we therefore argue that an intermediate step would be novel deep brain stimulation (DBS) protocols that emulate successful optogenetic "treatments" in animal models. Here we provide a roadmap of a translational path to rational, optogenetically inspired DBS protocols to refine existing approaches and expand it to novel indications. PMID:26062226

  11. A critical reflection on the technological development of deep brain stimulation (DBS

    Directory of Open Access Journals (Sweden)

    Christian eIneichen

    2014-09-01

    Full Text Available Since the translational research findings of Benabid and colleagues, which partly led to their seminal paper regarding the treatment of mainly tremor-dominant Parkinson patients through thalamic high-frequency-stimulation (HFS in 1987, we still struggle with identifying a satisfactory mechanistic explanation of the underlying principles of Deep Brain Stimulation. Furthermore, the technological advance of DBS devices (electrodes and implantable pulse generators, IPG's has shown a distinct lack of dynamic progression. In light of this we argue that it is time to leave the paleolithic age and enter hellenistic times: the device-manufacturing industry and the medical community together should put more emphasis on advancing the technology rather than resting on their laurels.

  12. Deep Brain Stimulation: More Complex than the Inhibition of Cells and Excitation of Fibers.

    Science.gov (United States)

    Florence, Gerson; Sameshima, Koichi; Fonoff, Erich T; Hamani, Clement

    2016-08-01

    High-frequency deep brain stimulation (DBS) is an effective treatment for some movement disorders. Though mechanisms underlying DBS are still unclear, commonly accepted theories include a "functional inhibition" of neuronal cell bodies and the excitation of axonal projections near the electrodes. It is becoming clear, however, that the paradoxical dissociation "local inhibition" and "distant excitation" is far more complex than initially thought. Despite an initial increase in neuronal activity following stimulation, cells are often unable to maintain normal ionic concentrations, particularly those of sodium and potassium. Based on currently available evidence, we proposed an alternative hypothesis. Increased extracellular concentrations of potassium during DBS may change the dynamics of both cells and axons, contributing not only to the intermittent excitation and inhibition of these elements but also to interrupt abnormal pathological activity. In this article, we review mechanisms through which high extracellular potassium may mediate some of the effects of DBS. PMID:26150316

  13. Characterization of a non linear fractional model of electrode-tissue impedance for neuronal stimulation

    OpenAIRE

    Kolbl, FLorian; Sabatier, Jocelyn; N'Kaoua, Gilles; Naudet, Frédéric; Faggiani, Emilie; Benazzouz, Abdelhamid; Renaud, Sylvie; Lewis, Noëlle

    2013-01-01

    International audience The design of neuro-stimulators must include a realistic model of electrode-tissue interface. Complex electrochemical phenomena associated to high levels of stimulation current give fractional and non linear behavior to this interface that simple linearized models fail to fit. This paper describes both a measurement protocol based on biphasic current-controlled solicitations and a modeling procedure relying on an original approach of multi-model, taking into account ...

  14. Assistance to planning in deep brain stimulation: data fusion method for locating anatomical targets in MRI.

    Science.gov (United States)

    Villéger, Alice; Ouchchane, Lemlih; Lemaire, Jean-Jacques; Boire, Jean-Yves

    2006-01-01

    Symptoms of Parkinson's disease can be relieved through deep brain stimulation. This neurosurgical technique relies on high precision positioning of electrodes in specific areas of the basal ganglia and the thalamus. In order to identify these anatomical targets, which are located deep within the brain, we developed a semi-automated method of image analysis, based on data fusion. Information provided by both anatomical magnetic resonance images and expert knowledge is managed in a common possibilistic frame, using a fuzzy logic approach. More specifically, a graph-based virtual atlas modeling theoretical anatomical knowledge is matched to the image data from each patient, through a research algorithm (or strategy) which simultaneously computes an estimation of the location of every structures, thus assisting the neurosurgeon in defining the optimal target. The method was tested on 10 images, with promising results. Location and segmentation results were statistically assessed, opening perspectives for enhancements. PMID:17946793

  15. Noninvasive transcranial focused ultrasonic-magnetic stimulation for modulating brain oscillatory activity

    Science.gov (United States)

    Yuan, Yi; Chen, Yudong; Li, Xiaoli

    2016-02-01

    A novel technique, transcranial focused ultrasonic-magnetic stimulation (tFUMS), has been developed for noninvasive brain modulation in vivo. tFUMS has a higher spatial resolution (stimulation on the neuromodulation. The results demonstrate that tFUMS can modulate brain oscillatory activities by stimulating brain tissues.

  16. Nerve stimulation with a multi-contact cuff electrode: validation of model predictions.

    Science.gov (United States)

    Deurloo, K E; Holsheimer, J; Bergveld, P

    2000-10-01

    The recruitment characteristics of muscle selective nerve stimulation by a multi-contact nerve cuff electrode, as predicted by computer modeling, have been investigated in acute experiments on rabbits. A nerve cuff containing five or six dot electrodes was placed around the sciatic nerve in five rabbits. M-waves were recorded with wire electrodes from the lateral gastrocnemius, soleus, tibialis anterior, and extensor digitorum longus muscles. The muscle recruitment performances of three contact configurations (monopole, transverse bipole, transverse tripole) were compared. The selectivity was quantified by the recruitment of two muscles (one extensor and one flexor) in response to a particular stimulus. The results showed that only in a few cases, transverse bi- and tripolar stimulation provided a better selectivity than monopolar stimulation. Neither of the two extensors, nor of the two flexors could be stimulated separately. In accordance with the results of the modeling studies, bi- and tripolar stimulation required higher stimulus currents than monopolar stimulation, whereas maximum recruitment and slopes of recruitment curves were lower. The rabbit sciatic nerve appears to be a less suitable preparation for reproducible selectivity experiments, due to the variability in the number and size of the fascicles and their position in this nerve. PMID:11094386

  17. Effects of Deep Brain Stimulation on Autonomic Function.

    Science.gov (United States)

    Basiago, Adam; Binder, Devin K

    2016-01-01

    Over the course of the development of deep brain stimulation (DBS) into a well-established therapy for Parkinson's disease, essential tremor, and dystonia, its utility as a potential treatment for autonomic dysfunction has emerged. Dysfunction of autonomic processes is common in neurological diseases. Depending on the specific target in the brain, DBS has been shown to raise or lower blood pressure, normalize the baroreflex, to alter the caliber of bronchioles, and eliminate hyperhidrosis, all through modulation of the sympathetic nervous system. It has also been shown to improve cortical control of the bladder, directly induce or inhibit the micturition reflex, and to improve deglutition and gastric emptying. In this review, we will attempt to summarize the relevant available studies describing these effects of DBS on autonomic function, which vary greatly in character and magnitude with respect to stimulation target. PMID:27537920

  18. Effects of Deep Brain Stimulation on Autonomic Function

    Directory of Open Access Journals (Sweden)

    Adam Basiago

    2016-08-01

    Full Text Available Over the course of the development of deep brain stimulation (DBS into a well-established therapy for Parkinson’s disease, essential tremor, and dystonia, its utility as a potential treatment for autonomic dysfunction has emerged. Dysfunction of autonomic processes is common in neurological diseases. Depending on the specific target in the brain, DBS has been shown to raise or lower blood pressure, normalize the baroreflex, to alter the caliber of bronchioles, and eliminate hyperhidrosis, all through modulation of the sympathetic nervous system. It has also been shown to improve cortical control of the bladder, directly induce or inhibit the micturition reflex, and to improve deglutition and gastric emptying. In this review, we will attempt to summarize the relevant available studies describing these effects of DBS on autonomic function, which vary greatly in character and magnitude with respect to stimulation target.

  19. Modulating Hippocampal Plasticity with In Vivo Brain Stimulation

    OpenAIRE

    Joyce G Rohan; Carhuatanta, Kim A.; McInturf, Shawn M.; Miklasevich, Molly K.; Jankord, Ryan

    2015-01-01

    Investigations into the use of transcranial direct current stimulation (tDCS) in relieving symptoms of neurological disorders and enhancing cognitive or motor performance have exhibited promising results. However, the mechanisms by which tDCS effects brain function remain under scrutiny. We have demonstrated that in vivo tDCS in rats produced a lasting effect on hippocampal synaptic plasticity, as measured using extracellular recordings. Ex vivo preparations of hippocampal slices from rats th...

  20. Robotic implantation of intracerebral electrodes for deep brain stimulation

    OpenAIRE

    Faria, Carlos André de Oliveira

    2012-01-01

    O objectivo desta dissertação é o desenvolvimento de uma abordagem inicial a um sistema robótico para desempenhar um papel de assistência em neurocirurgia estereotáxica de Estimulação Cerebral Profunda (DBS). O robô deve posicionar e manipular variados instrumentos cirúrgicos de uma forma passiva ou semi-ativa de acordo com diretivas pré-operativas ou com as instruções da equipa médica. O impacto atual dos distúrbios neurológicos sensíveis a DBS, o conhecimento subjacente de...

  1. Effects of electrode configuration and geometry on fiber preference in spinal cord stimulation

    NARCIS (Netherlands)

    Holsheimer, Jan; Struijk, Johannes J.; Wesselink, Wilbert A.

    1996-01-01

    In contrast to the widespread assumption that dorsal column fibers are the primary targets of spinal cord stimulation by a dorsal epidural electrode, it appears that dorsal root fibers are recruited as well, and even preferentially under various conditions. This will, however, limit the coverage of

  2. Does it matter that the contact impedance of spinal cord stimulation electrodes is variable?

    NARCIS (Netherlands)

    Holsheimer, J.; Manola, L.

    2006-01-01

    Objectives. The impedance of a percutaneous SCS electrode is highly variable and affects the currents injected by the various anodes (-) and cathodes (+) when using a standard single-channel, constant-voltage stimulation device. The impedance is affected in particular by the position of the percuta

  3. Strategy for control of muscle force using a 3D multi electrode array in intraneural stimulation

    NARCIS (Netherlands)

    Frieswijk, Theo A.; Dijkstra, Fred; Rutten, Wim L.C.

    1996-01-01

    A control algorithm for regulation of the force produced by the rat EDL muscle is presented, using a 128-electrodes intraneural stimulation device. The algorithm is based on force regulation in nature; its task is basically to find a combination of rate coding and recruitment to produce a required f

  4. The rationale for deep brain stimulation in Alzheimer's disease.

    Science.gov (United States)

    Mirzadeh, Zaman; Bari, Ausaf; Lozano, Andres M

    2016-07-01

    Alzheimer's disease is a major worldwide health problem with no effective therapy. Deep brain stimulation (DBS) has emerged as a useful therapy for certain movement disorders and is increasingly being investigated for treatment of other neural circuit disorders. Here we review the rationale for investigating DBS as a therapy for Alzheimer's disease. Phase I clinical trials of DBS targeting memory circuits in Alzheimer's disease patients have shown promising results in clinical assessments of cognitive function, neurophysiological tests of cortical glucose metabolism, and neuroanatomical volumetric measurements showing reduced rates of atrophy. These findings have been supported by animal studies, where electrical stimulation of multiple nodes within the memory circuit have shown neuroplasticity through stimulation-enhanced hippocampal neurogenesis and improved performance in memory tasks. The precise mechanisms by which DBS may enhance memory and cognitive functions in Alzheimer's disease patients and the degree of its clinical efficacy continue to be examined in ongoing clinical trials. PMID:26443701

  5. Analysis of spinal cord stimulation and design of epidural electrodes by computer modeling.

    Science.gov (United States)

    Holsheimer, J; Struijk, J J; Wesselink, W A

    1998-01-01

    This paper is an overview of the results of computer modeling of spinal cord stimulation, started ten years ago at the University of Twente, The Netherlands. Results are given of the analysis of various geometrical factors, including spinal anatomy, which influence the effect of spinal cord stimulation on nerve fiber recruitment and paresthesia coverage. In a second phase, the computer model was used for the design of new electrode configurations expected to give a better paresthesia coverage in the management of chronic pain. Two new electrode types are presented: the narrow bi-/tripole and the transverse tripole. The latter also enables adjusting the body area affected with paresthesia by means of a dual channel pulse generator giving simultaneous pulses, thereby limiting surgical interventions for electrode repositioning. PMID:22150882

  6. Deep brain stimulation for movement disorders: update on recent discoveries and outlook on future developments.

    Science.gov (United States)

    Mahlknecht, Philipp; Limousin, Patricia; Foltynie, Thomas

    2015-11-01

    Modern deep brain stimulation (DBS) has become a routine therapy for patients with movement disorders such as Parkinson's disease, generalized or segmental dystonia and for multiple forms of tremor. Growing numbers of publications also report beneficial effects in other movement disorders such as Tourette's syndrome, various forms of chorea and DBS is even being studied for Parkinson's-related dementia. While exerting remarkable effects on many motor symptoms, DBS does not restore normal neurophysiology and therefore may also have undesirable side effects including speech and gait deterioration. Furthermore, its efficacy might be compromised in the long term, due to progression of the underlying disease. Various programming strategies have been studied to try and address these issues, e.g., the use of low-frequency rather than high-frequency stimulation or the targeting of alternative brain structures such as the pedunculopontine nucleus. In addition, further technical developments will soon provide clinicians with an expanded choice of hardware such as segmented electrodes allowing for a steering of the current to optimize beneficial effects and reduce side effects as well as the possibility of adaptive stimulation systems based on closed-loop concepts with or without accompanying advances in programming and imaging software. In the present article, we will provide an update on the most recent achievements and discoveries relevant to the application of DBS in the treatment of movement disorder patients and give an outlook on future clinical and technical developments. PMID:26037016

  7. Amorphous and crystalline IrO2 thin films as potential stimulation electrode coatings

    International Nuclear Information System (INIS)

    Amorphous and crystalline iridium oxide thin films with potential use as coating materials for stimulation electrodes were studied. Characterization of these films by cyclic voltammetry and impedance spectroscopy has revealed a considerable decrease in impedance and an increase in charge capacity of iridium oxide thin films after an electrochemical activation process in 0.9% NaCl solution. The surface morphology of these films was studied by scanning electron microscopy. The two types of IrO2 films were also compared under conditions relevant to applications as stimulation electrodes. The results indicate that amorphous IrO2 films have significantly higher charge storage capacity and lower impedance than crystalline IrO2 films. This makes the amorphous films a preferable coating material for stimulation applications

  8. Optimal control of directional deep brain stimulation in the parkinsonian neuronal network

    Science.gov (United States)

    Fan, Denggui; Wang, Zhihui; Wang, Qingyun

    2016-07-01

    The effect of conventional deep brain stimulation (DBS) on debilitating symptoms of Parkinson's disease can be limited because it can only yield the spherical field. And, some side effects are clearly induced with influencing their adjacent ganglia. Recent experimental evidence for patients with Parkinson's disease has shown that a novel DBS electrode with 32 independent stimulation source contacts can effectively optimize the clinical therapy by enlarging the therapeutic windows, when it is applied on the subthalamic nucleus (STN). This is due to the selective activation in clusters of various stimulation contacts which can be steered directionally and accurately on the targeted regions of interest. In addition, because of the serious damage to the neural tissues, the charge-unbalanced stimulation is not typically indicated and the real DBS utilizes charge-balanced bi-phasic (CBBP) pulses. Inspired by this, we computationally investigate the optimal control of directional CBBP-DBS from the proposed parkinsonian neuronal network of basal ganglia-thalamocortical circuit. By appropriately tuning stimulation for different neuronal populations, it can be found that directional steering CBBP-DBS paradigms are superior to the spherical case in improving parkinsonian dynamical properties including the synchronization of neuronal populations and the reliability of thalamus relaying the information from cortex, which is in a good agreement with the physiological experiments. Furthermore, it can be found that directional steering stimulations can increase the optimal stimulation intensity of desynchronization by more than 1 mA compared to the spherical case. This is consistent with the experimental result with showing that there exists at least one steering direction that can allow increasing the threshold of side effects by 1 mA. In addition, we also simulate the local field potential (LFP) and dominant frequency (DF) of the STN neuronal population induced by the activation

  9. High permeability cores to optimize the stimulation of deeply located brain regions using transcranial magnetic stimulation

    International Nuclear Information System (INIS)

    Efficient stimulation of deeply located brain regions with transcranial magnetic stimulation (TMS) poses many challenges, arising from the fact that the induced field decays rapidly and becomes less focal with depth. We propose a new method to improve the efficiency of TMS of deep brain regions that combines high permeability cores, to increase focality and field intensity, with a coil specifically designed to induce a field that decays slowly with increasing depth. The performance of the proposed design was investigated using the finite element method to determine the total electric field induced by this coil/core arrangement on a realistically shaped homogeneous head model. The calculations show that the inclusion of the cores increases the field's magnitude by as much as 25% while also decreasing the field's decay with depth along specific directions. The focality, as measured by the area where the field's norm is greater than 1/√2 of its maximum value, is also improved by as much as 15% with some core arrangements. The coil's inductance is not significantly increased by the cores. These results show that the presence of the cores might make this specially designed coil even more suited for the effective stimulation of deep brain regions.

  10. Modulation of untruthful responses with noninvasive brain stimulation

    Directory of Open Access Journals (Sweden)

    FelipeFregni

    2013-02-01

    Full Text Available Deceptive abilities have long been studied in relation to personality traits. More recently, studies explored the neural substrates associated with deceptive skills suggesting a critical role of the prefrontal cortex. Here we investigated whether noninvasive brain stimulation over the dorsolateral prefrontal cortex (DLPFC could modulate generation of untruthful responses about subject’s personal life across contexts (i.e., deceiving on guilt-free questions on daily activities; generating previously memorized lies about past experience; and producing spontaneous lies about past experience, as well as across modality responses (verbal and motor responses. Results reveal that real, but not sham, transcranial direct current stimulation (tDCS over the DLPFC can reduce response latency for untruthful over truthful answers across contexts and modality responses. Also, contexts of lies seem to incur a different hemispheric laterality. These findings add up to previous studies demonstrating that it is possible to modulate some processes involved in generation of untruthful answers by applying noninvasive brain stimulation over the DLPFC and extend these findings by showing a differential hemispheric contribution of DLPFCs according to contexts.

  11. Experimental Study of the Course of Threshold Current, Voltage and Electrode Impedance During Stepwise Stimulation From the Skin Surface to the Human Cortex

    NARCIS (Netherlands)

    Szelenyi, Andrea; Journee, Henricus Louis; Herrlich, Simon; Galistu, Gianni M.; van den Berg, Joris; van Dijk, J. Marc C.

    2013-01-01

    Background: Transcranial electric stimulation as used during intraoperative neurostimulation is dependent on electrode and skull impedances. Objective: Threshold currents, voltages and electrode impedances were evaluated with electrical stimulation at 8 successive layers between the skin and the cer

  12. Treatment of Wilson's disease motor complications with deep brain stimulation.

    Science.gov (United States)

    Hedera, Peter

    2014-05-01

    A considerable proportion of patients with Wilson's disease (WD) experience neurologic symptoms that are functionally disabling. The most common neurologic problems in advanced WD include dystonia and tremor. Medically refractory idiopathic dystonia and essential tremor (ET) have been successfully treated with deep brain stimulation (DBS), functional surgical therapy targeting the globus pallidus pars interna (GPi), or the ventral intermediate (Vim) thalamic nucleus. Even though the pathophysiology of tremor is different in WD and ET, available experience supports DBS targeting the Vim for WD patients. Dystonia associated with WD is classified as secondary dystonia and GPi stimulation has yielded mixed results in these patients. The presence of structural changes in the basal ganglia may limit the therapeutic success of DBS for WD dystonia compared with idiopathic dystonia. In spite of these limitations, DBS in WD may be an effective approach to treat medically refractory residual neurologic symptoms in carefully selected patients. PMID:24547944

  13. Deep brain stimulation: current applications and future prospects.

    Science.gov (United States)

    Suchorska, Bogdana; Ruge, Maximilian I

    2015-12-01

    Deep Brain Stimulation (DBS) has proven to be an effective and minimally invasive surgical treatment for a variety of neurological and psychiatric diseases such as Parkinson's Disease, essential tremor, dystonia, Tourette's Syndrome and depression. In contrast to early surgical lesioning procedures, DBS has a considerably lower side-effect rate and is usually reversible. Common targets include nuclei involved in the basal ganglia circuitry as well as its efferent and afferent pathways such as the subthalamic nucleus (STN), the globus pallidus internus (GPi) or the ventral striatal region. Despite the increasing application of DBS, the exact mechanism of action is still matter of debates. Current trials focus on establishing alternative targets, exploring new indications as well as on capturing cortical responses during DBS in order to improve individual stimulation parameters. PMID:26760984

  14. Postoperative control in deep brain stimulation of the subthalamic region: the contact membership concept

    International Nuclear Information System (INIS)

    In deep brain stimulation, the anatomic positions of electrode contact centers are used as the basis for analysis. We propose a new semi-quantitative approach (contact membership concept) considering patient's individual anatomy, contact size, and extent of involvement of STN and neighboring structures. In ten bilaterally operated and improved Parkinsonian patients, effective contact positions (contacts used for monopolar stimulation) were analyzed. The position of the contact center (classical binary approach: each center assigned, 1, or not, 0, to a given structure) and of the contact in its dimension (contact membership concept: membership degree, ordinal values from 0 to 1, assigned to each anatomic structure according to extent of involvement) were compared for the whole patient group and, individually, for each patient. The membership concept revealed that for 13 out of 20 contacts, more than one structure was involved, where the classical binary approach assigned only one structure. For both approaches lateral STN, zona incerta and H1 (Forel's Field) were the main structures involved, but their frequencies of appearance differed. The membership concept allows detailed analysis of the anatomic contact position. In the future this approach could assist in correlating anatomy and clinical results for all electrode contacts (effective ones and clinically less efficient ones). (orig.)

  15. Clinical, neuropsychological, and pre-stimulus dorsomedial thalamic nucleus electrophysiological data in deep brain stimulation patients.

    Science.gov (United States)

    Sweeney-Reed, Catherine M; Zaehle, Tino; Voges, Jürgen; Schmitt, Friedhelm C; Buentjen, Lars; Kopitzki, Klaus; Richardson-Klavehn, Alan; Hinrichs, Hermann; Heinze, Hans-Jochen; Knight, Robert T; Rugg, Michael D

    2016-09-01

    The data presented here comprise clinical, neuropsychological, and intrathalamic electrophysiological data from 7 patients with pharmacoresistant focal epilepsy and are related to the article "Pre-stimulus thalamic theta power predicts human memory formation" C.M. Sweeney-Reed, T. Zaehle, J. Voges, F.C. Schmitt, L. Buentjen, K. Kopitzki, et al. (2016) [1]. The patients participated in a memory paradigm after receiving electrodes implanted in the DMTN due to the surgical approach taken in electrode insertion for deep brain stimulation of the anterior thalamic nucleus. Epilepsy duration and pre-operative neuropsychological tests provide an indication of the profile of patients receiving intrathalamic electrode implantation and the memory capabilities in such a patient group. The electrophysiological data were recorded from the right DMTN preceding stimulus presentation during intentional memory encoding. The patients viewed a series of photographic scenes, which they judged as indoors or outdoors. The 900 ms epochs prior to stimulus presentation were labeled as preceding successful or unsuccessful subsequent memory formation according to a subsequent memory test for the items. The difference between theta power preceding successful versus unsuccessful subsequent memory formation is shown against time for each patient individually. PMID:27508216

  16. Transcranial brain stimulation to promote functional recovery after stroke

    DEFF Research Database (Denmark)

    Raffin, Estelle; Siebner, Hartwig R

    2014-01-01

    therapeutic efficacy. SUMMARY: This review addressed six questions: How does NIBS facilitate the recovery of function after stroke? Which brain regions should be targeted by NIBS? Is there a particularly effective NIBS modality that should be used? Does the location of the stroke influence the therapeutic......PURPOSE OF REVIEW: Noninvasive brain stimulation (NIBS) is increasingly used to enhance the recovery of function after stroke. The purpose of this review is to highlight and discuss some unresolved questions that need to be addressed to better understand and exploit the potential of NIBS as a...... therapeutic tool. RECENT FINDINGS: Recent meta-analyses showed that the treatment effects of NIBS in patients with stroke are rather inconsistent across studies and the evidence for therapeutic efficacy is still uncertain. This raises the question of how NIBS can be developed further to improve its...

  17. Increment of brain temporal perfusion during auditory stimulation

    International Nuclear Information System (INIS)

    A study on the dynamic exploration of the auditory pathway is presented, in which technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPET) was used in volunteers with normal hearing. Changes in 99mTc-HMPAO distribution were calculated using a region of interest/whole-brain count ratio. The results showed a temporal perfusion increment of 17% (right) and 19% (left) during tonal supraliminar stimulation, which was significantly different from the control ROI. Sensitivity tests for the method were requested before any clinical application. (orig.)

  18. Diffusion Tractography in Deep Brain Stimulation Surgery: A Review

    Science.gov (United States)

    Calabrese, Evan

    2016-01-01

    Deep brain stimulation (DBS) is believed to exert its therapeutic effects through modulation of brain circuitry, yet conventional preoperative planning does not allow direct targeting or visualization of white matter pathways. Diffusion MRI tractography (DT) is virtually the only non-invasive method of visualizing structural connectivity in the brain, leading many to suggest its use to guide DBS targeting. DT-guided DBS not only has the potential to allow direct white matter targeting for established applications [e.g., Parkinson’s disease (PD), essential tremor (ET), dystonia], but may also aid in the discovery of new therapeutic targets for a variety of other neurologic and psychiatric diseases. Despite these exciting opportunities, DT lacks standardization and rigorous anatomic validation, raising significant concern for the use of such data in stereotactic brain surgery. This review covers the technical details, proposed methods, and initial clinical data for the use of DT in DBS surgery. Rather than focusing on specific disease applications, this review focuses on methods that can be applied to virtually any DBS target. PMID:27199677

  19. Aligned Nanofibers from Polypyrrole/Graphene as Electrodes for Regeneration of Optic Nerve via Electrical Stimulation.

    Science.gov (United States)

    Yan, Lu; Zhao, Bingxin; Liu, Xiaohong; Li, Xuan; Zeng, Chao; Shi, Haiyan; Xu, Xiaoxue; Lin, Tong; Dai, Liming; Liu, Yong

    2016-03-23

    The damage of optic nerve will cause permanent visual field loss and irreversible ocular diseases, such as glaucoma. The damage of optic nerve is mainly derived from the atrophy, apoptosis or death of retinal ganglion cells (RGCs). Though some progress has been achieved on electronic retinal implants that can electrically stimulate undamaged parts of RGCs or retina to transfer signals, stimulated self-repair/regeneration of RGCs has not been realized yet. The key challenge for development of electrically stimulated regeneration of RGCs is the selection of stimulation electrodes with a sufficient safe charge injection limit (Q(inj), i.e., electrochemical capacitance). Most traditional electrodes tend to have low Q(inj) values. Herein, we synthesized polypyrrole functionalized graphene (PPy-G) via a facile but efficient polymerization-enhanced ball milling method for the first time. This technique could not only efficiently introduce electron-acceptor nitrogen to enhance capacitance, but also remain a conductive platform-the π-π conjugated carbon plane for charge transportation. PPy-G based aligned nanofibers were subsequently fabricated for guided growth and electrical stimulation (ES) of RGCs. Significantly enhanced viability, neurite outgrowth and antiaging ability of RGCs were observed after ES, suggesting possibilities for regeneration of optic nerve via ES on the suitable nanoelectrodes. PMID:26926578

  20. Deep brain stimulation for obsessive-compulsive disorder and treatment-resistant depression: systematic review

    Directory of Open Access Journals (Sweden)

    Callaway Enoch

    2010-03-01

    Full Text Available Abstract Background In spite of advances in psychotherapy and pharmacotherapy, there are still a significant number of patients with depression and obsessive-compulsive disorder that are not aided by either intervention. Although still in the experimental stage, deep brain stimulation (DBS offers many advantages over other physically-invasive procedures as a treatment for these psychiatric disorders. The purpose of this study is to systematically review reports on clinical trials of DBS for obsessive-compulsive disorder (OCD and treatment-resistant depression (TRD. Locations for stimulation, success rates and effects of the stimulation on brain metabolism are noted when available. The first observation of the effects of DBS on OCD and TRD came in the course of using DBS to treat movement disorders. Reports of changes in OCD and depression during such studies are reviewed with particular attention to electrode locations and associated adverse events; although these reports were adventitious observations rather than planned. Subsequent studies have been guided by more precise theories of structures involved in DBS and OICD. This study suggests stimulation sites and prognostic indicators for DBS. We also briefly review tractography, a relatively new procedure that holds great promise for the further development of DBS. Methods Articles were retrieved from MEDLINE via PubMed. Relevant references in retrieved articles were followed up. We included all articles reporting on studies of patients selected for having OCD or TRD. Adequacy of the selected studies was evaluated by the Jadad scale. Evaluation criteria included: number of patients, use of recognized psychiatric rating scales, and use of brain blood flow measurements. Success rates classified as "improved" or "recovered" were recorded. Studies of DBS for movement disorders were included if they reported coincidental relief of depression or reduction in OCD. Most of the studies involved small

  1. Evaluation of Interactive Visualization on Mobile Computing Platforms for Selection of Deep Brain Stimulation Parameters.

    Science.gov (United States)

    Butson, Christopher R; Tamm, Georg; Jain, Sanket; Fogal, Thomas; Krüger, Jens

    2013-01-01

    In recent years, there has been significant growth in the use of patient-specific models to predict the effects of neuromodulation therapies such as deep brain stimulation (DBS). However, translating these models from a research environment to the everyday clinical workflow has been a challenge, primarily due to the complexity of the models and the expertise required in specialized visualization software. In this paper, we deploy the interactive visualization system ImageVis3D Mobile, which has been designed for mobile computing devices such as the iPhone or iPad, in an evaluation environment to visualize models of Parkinson's disease patients who received DBS therapy. Selection of DBS settings is a significant clinical challenge that requires repeated revisions to achieve optimal therapeutic response, and is often performed without any visual representation of the stimulation system in the patient. We used ImageVis3D Mobile to provide models to movement disorders clinicians and asked them to use the software to determine: 1) which of the four DBS electrode contacts they would select for therapy; and 2) what stimulation settings they would choose. We compared the stimulation protocol chosen from the software versus the stimulation protocol that was chosen via clinical practice (independent of the study). Lastly, we compared the amount of time required to reach these settings using the software versus the time required through standard practice. We found that the stimulation settings chosen using ImageVis3D Mobile were similar to those used in standard of care, but were selected in drastically less time. We show how our visualization system, available directly at the point of care on a device familiar to the clinician, can be used to guide clinical decision making for selection of DBS settings. In our view, the positive impact of the system could also translate to areas other than DBS. PMID:22450824

  2. Evaluation of deep brain stimulation for Parkinson's disease by using FDG PET

    International Nuclear Information System (INIS)

    Objective: Patients are effectively treated with medication in their initial phases of Parkinson's disease. However, the drugs become less effective and the adverse effects revealed. Recent years, the chronic deep brain stimulation is becoming an important treatment for patients with patients with Parkinson's disease. It has shown that the Parkinson's state is characterized by pathological neural activity in the motor system including the internal segment of the globus pallidus (GPi) and the subthalamic nucleus (STN). The chronic deep brain stimulation can make benefits in the patients by intermediate the pathological neural activity. It needs an external method to evaluate the mechanism of therapy and to monitor the effect of treatment. The objective of our study is to observe the regional glucose metabolism changes in the motor loops and demonstrate the mechanism of therapy and how to monitor the treatment. Patients and Methods: Employing FDG PET, we had studied 7 patients who suffered from Parkinson's disease all the patients were failing medical therapy.the electrodes were implanted in the brain by the direction of MRI.The target of DBS is STN. Resting FDG PET were performed on and off STN stimulation. Metabolic changes with DBS were correlated with clinical improvement as measured by changes in Unified Parkinson's Disease Rating Scale (UPDRS) motor ratings off medication. PET imaging was read by visual interpretation in blind method and calculated by semi-quantitative analysis. The statistic data was analysis after FDG PET imaging. Results: Through the research, regional cerebral glucose metabolic changes with DBS on and off were correlated with clinical improvement as measured by changes in Unified Parkinson's Disease Rating Scale (UPDRS) motor ratings. STN DBS improved UPDRS motor ratings (33%, P<0.001) and significantly increased regional glucose metabolism in the frontal lobe, temporal lobe, Parietal lobe cortex ipsilateral to stimulation. The heighten

  3. Systemic stimulation of TLR2 impairs neonatal mouse brain development.

    Directory of Open Access Journals (Sweden)

    Xiaonan Du

    Full Text Available BACKGROUND: Inflammation is associated with perinatal brain injury but the underlying mechanisms are not completely characterized. Stimulation of Toll-like receptors (TLRs through specific agonists induces inflammatory responses that trigger both innate and adaptive immune responses. The impact of engagement of TLR2 signaling pathways on the neonatal brain is still unclear. The aim of this study was to investigate the potential effect of a TLR2 agonist on neonatal brain development. METHODOLOGY/PRINCIPAL FINDINGS: Mice were injected intraperitoneally (i.p. once a day from postnatal day (PND 3 to PND11 with endotoxin-free saline, a TLR2 agonist Pam(3CSK(4 (5 mg/kg or Lipopolysaccharide (LPS, 0.3 mg/kg. Pups were sacrificed at PND12 or PND53 and brain, spleen and liver were collected and weighed. Brain sections were stained for brain injury markers. Long-term effects on memory function were assessed using the Trace Fear Conditioning test at PND50. After 9 days of Pam(3CSK(4 administration, we found a decreased volume of cerebral gray matter, white matter in the forebrain and cerebellar molecular layer that was accompanied by an increase in spleen and liver weight at PND12. Such effects were not observed in Pam3CSK4-treated TLR 2-deficient mice. Pam3CSK4-treated mice also displayed decreased hippocampus neuronal density, and increased cerebral microglia density, while there was no effect on caspase-3 or general cell proliferation at PND12. Significantly elevated levels of IL-1β, IL-6, KC, and MCP-1 were detected after the first Pam3CSK4 injection in brain homogenates of PND3 mice. Pam(3CSK(4 administration did not affect long-term memory function nor the volume of gray or white matter. CONCLUSIONS/SIGNIFICANCE: Repeated systemic exposure to the TLR2 agonist Pam(3CSK(4 can have a short-term negative impact on the neonatal mouse brain.

  4. Orosensory self-stimulation by sucrose involves brain dopaminergic mechanisms.

    Science.gov (United States)

    Schneider, L H

    1989-01-01

    The most convincing body of evidence supporting a role for brain dopaminergic mechanisms in sweet taste reward has been obtained using the sham-feeding rat. In rats prepared with a chronic gastric fistula and tested with the cannula open, intake is a direct function of the palatability of the solution offered as well as of the state of food deprivation. Because essentially none of the ingested fluid passes on to the intestine, negative postingestive feedback is eliminated. Thus, the relative orosensory/hedonic potency of the food determines and sustains the rate of sham intake; long periods of food deprivation are not required. In this way, the sham feeding of sweet solutions may be considered a form of oral self-stimulation behavior and afford a preparation through which the neurochemical and neuranatomical substrates of sweet taste reward may be identified. The results obtained in the series of experiments summarized in this paper clearly indicate that central D-1 and D-2 receptor mechanisms are critical for the orosensory self-stimulation by sucrose in the rat. In conclusion, I suggest that such investigations of the roles of brain dopaminergic mechanisms in the sucrose sham-feeding rat preparation may further our understanding of normal and aberrant attractions to sweet fluids in humans (see Cabanac, Drewnowski, and Halmi, this volume), as an innate, positive affective response of human neonates to sucrose and the sustained positive hedonic ratings for glucose when tasted but not when consumed have demonstrated. PMID:2699194

  5. The anteromedial GPi as a new target for deep brain stimulation in obsessive compulsive disorder.

    Science.gov (United States)

    Nair, Girish; Evans, Andrew; Bear, Renee E; Velakoulis, Dennis; Bittar, Richard G

    2014-05-01

    Deep brain stimulation (DBS) is now well established in the treatment of intractable movement disorders. Over the past decade the clinical applications have expanded into the realm of psychosurgery, including depression and obsessive compulsive disorder (OCD). The optimal targets for electrode placement in psychosurgery remain unclear, with numerous anatomical targets reported for the treatment of OCD. We present four patients with Tourette's syndrome and prominent features of OCD who underwent DBS of the anteromedial globus pallidus internus (GPi) to treat their movement disorder. Their pre-operative and post-operative OCD symptoms were compared, and responded dramatically to surgery. On the basis of these results, we propose the anteromedial (limbic) GPi as a potential surgical target for the treatment of OCD, and furnish data supporting its further investigation as a DBS target for the treatment of psychiatric conditions. PMID:24524950

  6. Electrical stimulation of the brain and the development of cortical visual prostheses: An historical perspective.

    Science.gov (United States)

    Lewis, Philip M; Rosenfeld, Jeffrey V

    2016-01-01

    Rapid advances are occurring in neural engineering, bionics and the brain-computer interface. These milestones have been underpinned by staggering advances in micro-electronics, computing, and wireless technology in the last three decades. Several cortically-based visual prosthetic devices are currently being developed, but pioneering advances with early implants were achieved by Brindley followed by Dobelle in the 1960s and 1970s. We have reviewed these discoveries within the historical context of the medical uses of electricity including attempts to cure blindness, the discovery of the visual cortex, and opportunities for cortex stimulation experiments during neurosurgery. Further advances were made possible with improvements in electrode design, greater understanding of cortical electrophysiology and miniaturisation of electronic components. Human trials of a new generation of prototype cortical visual prostheses for the blind are imminent. This article is part of a Special Issue entitled Hold Item. PMID:26348986

  7. Weight Gain following Pallidal Deep Brain Stimulation: A PET Study.

    Science.gov (United States)

    Sauleau, Paul; Drapier, Sophie; Duprez, Joan; Houvenaghel, Jean-François; Dondaine, Thibaut; Haegelen, Claire; Drapier, Dominique; Jannin, Pierre; Robert, Gabriel; Le Jeune, Florence; Vérin, Marc

    2016-01-01

    The mechanisms behind weight gain following deep brain stimulation (DBS) surgery seem to be multifactorial and suspected depending on the target, either the subthalamic nucleus (STN) or the globus pallidus internus (GPi). Decreased energy expenditure following motor improvement and behavioral and/or metabolic changes are possible explanations. Focusing on GPi target, our objective was to analyze correlations between changes in brain metabolism (measured with PET) and weight gain following GPi-DBS in patients with Parkinson's disease (PD). Body mass index was calculated and brain activity prospectively measured using 2-deoxy-2[18F]fluoro-D-glucose PET four months before and four months after the start of GPi-DBS in 19 PD patients. Dopaminergic medication was included in the analysis to control for its possible influence on brain metabolism. Body mass index increased significantly by 0.66 ± 1.3 kg/m2 (p = 0.040). There were correlations between weight gain and changes in brain metabolism in premotor areas, including the left and right superior gyri (Brodmann area, BA 6), left superior gyrus (BA 8), the dorsolateral prefrontal cortex (right middle gyrus, BAs 9 and 46), and the left and right somatosensory association cortices (BA 7). However, we found no correlation between weight gain and metabolic changes in limbic and associative areas. Additionally, there was a trend toward a correlation between reduced dyskinesia and weight gain (r = 0.428, p = 0.067). These findings suggest that, unlike STN-DBS, motor improvement is the major contributing factor for weight gain following GPi-DBS PD, confirming the motor selectivity of this target. PMID:27070317

  8. Muscle twitch responses for shaping the multi-pad electrode for functional electrical stimulation

    Directory of Open Access Journals (Sweden)

    Malešević Nebojša

    2010-01-01

    Full Text Available In this paper we present a method for optimization of multi-pad electrode spatial selectivity during transcutaneous Functional Electrical Stimulation (FES of hand. The presented method is based on measurement of individual muscle twitch responses during low frequency electrical stimulation via pads within multi-pad electrode. Twitch responses are recorded by Micro-Electro-Mechanical Systems (MEMS accelerometers. The aim of this methodology is to substitute bulky sensors, torque sensors and goniometers, in multi-pad electrode optimization algorithm with smaller and lighter sensors; therefore making multi-pad stimulation suitable for daily use. Additionally we present method for minimizing number of MEMS accelerometers, which relies on characteristic waveforms of joint acceleration during wrist or fingers flexion/extension. These signals can be used to train Artificial Neural Network (ANN to distinguish between different waveform classes and define correlation of each pad and activated muscle beneath. Results presented in this paper show high agreement of goniometers based classification and accelerometers based classification. As for classification with minimized number of sensors (one accelerometer our ANN backed algorithm achieved high degree of accurate classification in intra-subject testing, but lower performance in inter-subject testing.

  9. The stimulated social brain: effects of transcranial direct current stimulation on social cognition.

    Science.gov (United States)

    Sellaro, Roberta; Nitsche, Michael A; Colzato, Lorenza S

    2016-04-01

    Transcranial direct current stimulation (tDCS) is an increasingly popular noninvasive neuromodulatory tool in the fields of cognitive and clinical neuroscience and psychiatry. It is an inexpensive, painless, and safe brain-stimulation technique that has proven to be effective in modulating cognitive and sensory-perceptual functioning in healthy individuals and clinical populations. Importantly, recent findings have shown that tDCS may also be an effective and promising tool for probing the neural mechanisms of social cognition. In this review, we present the state-of-the-art of the field of tDCS research in social cognition. By doing so, we aim to gather knowledge of the potential of tDCS to modulate social functioning and social decision making in healthy humans, and to inspire future research investigations. PMID:27206250

  10. Deep Brain Stimulation Response in Pathologically Confirmed Cases of Multiple System Atrophy

    OpenAIRE

    Ullman, Michael; Vedam-Mai, Vinata; Resnick, Andrew S.; Yachnis, Anthony T.; McFarland, Nikolaus R.; Merritt, Stacy; Zeilman, Pamela; Foote, Kelly D; Okun, Michael S.

    2011-01-01

    Deep brain stimulation is a treatment for select cases of medication refractory movement disorders including Parkinson’s disease. Deep brain stimulation has not been recommended for treatment in multiple system atrophy patients. However, the paucity of literature documenting the effects of deep brain stimulation in multiple system atrophy patients and the revelation of a levodopa-responsive subtype of multiple system atrophy suggests further investigation is necessary.

  11. Electrical stimulation alleviates depressive-like behaviors of rats: investigation of brain targets and potential mechanisms

    OpenAIRE

    Lim, L.W.; Prickaerts, J.; Huguet, G; Kadar, E; Hartung, H; Sharp, T; Y. Temel

    2015-01-01

    Deep brain stimulation (DBS) is a promising therapy for patients with refractory depression. However, key questions remain with regard to which brain target(s) should be used for stimulation, and which mechanisms underlie the therapeutic effects. Here, we investigated the effect of DBS, with low- and high-frequency stimulation (LFS, HFS), in different brain regions (ventromedial prefrontal cortex, vmPFC; cingulate cortex, Cg; nucleus accumbens (NAc) core or shell; lateral habenula, LHb; and v...

  12. Electrodic voltages accompanying stimulated bioremediation of a uranium-contaminated aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Williams, K.H.; N' Guessan, A.L.; Druhan, J.; Long, P.E.; Hubbard, S.S.; Lovley, D.R.; Banfield, J.F.

    2009-11-15

    The inability to track the products of subsurface microbial activity during stimulated bioremediation has limited its implementation. We used spatiotemporal changes in electrodic potentials (EP) to track the onset and persistence of stimulated sulfate-reducing bacteria in a uranium-contaminated aquifer undergoing acetate amendment. Following acetate injection, anomalous voltages approaching -900 mV were measured between copper electrodes within the aquifer sediments and a single reference electrode at the ground surface. Onset of EP anomalies correlated in time with both the accumulation of dissolved sulfide and the removal of uranium from groundwater. The anomalies persisted for 45 days after halting acetate injection. Current-voltage and current-power relationships between measurement and reference electrodes exhibited a galvanic response, with a maximum power density of 10 mW/m{sup 2} during sulfate reduction. We infer that the EP anomalies resulted from electrochemical differences between geochemically reduced regions and areas having higher oxidation potential. Following the period of sulfate reduction, EP values ranged from -500 to -600 mV and were associated with elevated concentrations of ferrous iron. Within 10 days of the voltage decrease, uranium concentrations rebounded from 0.2 to 0.8 {mu}M, a level still below the background value of 1.5 {mu}M. These findings demonstrate that EP measurements provide an inexpensive and minimally invasive means for monitoring the products of stimulated microbial activity within aquifer sediments and are capable of verifying maintenance of redox conditions favorable for the stability of bioreduced contaminants, such as uranium.

  13. Electrodic voltages accompanying stimulated bioremediation of a uranium-contaminated aquifer

    Science.gov (United States)

    Williams, Kenneth H.; N'guessan, A. Lucie; Druhan, Jennifer; Long, Philip E.; Hubbard, Susan S.; Lovley, Derek R.; Banfield, Jillian F.

    2010-06-01

    The inability to track the products of subsurface microbial activity during stimulated bioremediation has limited its implementation. We used spatiotemporal changes in electrodic potentials (EP) to track the onset and persistence of stimulated sulfate-reducing bacteria in a uranium-contaminated aquifer undergoing acetate amendment. Following acetate injection, anomalous voltages approaching -900 mV were measured between copper electrodes within the aquifer sediments and a single reference electrode at the ground surface. Onset of EP anomalies correlated in time with both the accumulation of dissolved sulfide and the removal of uranium from groundwater. The anomalies persisted for 45 days after halting acetate injection. Current-voltage and current-power relationships between measurement and reference electrodes exhibited a galvanic response, with a maximum power density of 10 mW/m2 during sulfate reduction. We infer that the EP anomalies resulted from electrochemical differences between geochemically reduced regions and areas having higher oxidation potential. Following the period of sulfate reduction, EP values ranged from -500 to -600 mV and were associated with elevated concentrations of ferrous iron. Within 10 days of the voltage decrease, uranium concentrations rebounded from 0.2 to 0.8 μM, a level still below the background value of 1.5 μM. These findings demonstrate that EP measurements provide an inexpensive and minimally invasive means for monitoring the products of stimulated microbial activity within aquifer sediments and are capable of verifying maintenance of redox conditions favorable for the stability of bioreduced contaminants, such as uranium.

  14. A neurochemical closed-loop controller for deep brain stimulation: toward individualized smart neuromodulation therapies.

    Science.gov (United States)

    Grahn, Peter J; Mallory, Grant W; Khurram, Obaid U; Berry, B Michael; Hachmann, Jan T; Bieber, Allan J; Bennet, Kevin E; Min, Hoon-Ki; Chang, Su-Youne; Lee, Kendall H; Lujan, J L

    2014-01-01

    Current strategies for optimizing deep brain stimulation (DBS) therapy involve multiple postoperative visits. During each visit, stimulation parameters are adjusted until desired therapeutic effects are achieved and adverse effects are minimized. However, the efficacy of these therapeutic parameters may decline with time due at least in part to disease progression, interactions between the host environment and the electrode, and lead migration. As such, development of closed-loop control systems that can respond to changing neurochemical environments, tailoring DBS therapy to individual patients, is paramount for improving the therapeutic efficacy of DBS. Evidence obtained using electrophysiology and imaging techniques in both animals and humans suggests that DBS works by modulating neural network activity. Recently, animal studies have shown that stimulation-evoked changes in neurotransmitter release that mirror normal physiology are associated with the therapeutic benefits of DBS. Therefore, to fully understand the neurophysiology of DBS and optimize its efficacy, it may be necessary to look beyond conventional electrophysiological analyses and characterize the neurochemical effects of therapeutic and non-therapeutic stimulation. By combining electrochemical monitoring and mathematical modeling techniques, we can potentially replace the trial-and-error process used in clinical programming with deterministic approaches that help attain optimal and stable neurochemical profiles. In this manuscript, we summarize the current understanding of electrophysiological and electrochemical processing for control of neuromodulation therapies. Additionally, we describe a proof-of-principle closed-loop controller that characterizes DBS-evoked dopamine changes to adjust stimulation parameters in a rodent model of DBS. The work described herein represents the initial steps toward achieving a "smart" neuroprosthetic system for treatment of neurologic and psychiatric disorders

  15. A neurochemical closed-loop controller for deep brain stimulation: toward individualized smart neuromodulation therapies.

    Directory of Open Access Journals (Sweden)

    Peter Jonas Grahn

    2014-06-01

    Full Text Available Current strategies for optimizing deep brain stimulation (DBS therapy involve multiple postoperative visits. During each visit, stimulation parameters are adjusted until desired therapeutic effects are achieved and adverse effects are minimized. However, the efficacy of these therapeutic parameters may decline with time due at least in part to disease progression, interactions between the host environment and the electrode, and lead migration. As such, development of closed-loop control systems that can respond to changing neurochemical environments, tailoring DBS therapy to individual patients, is paramount for improving the therapeutic efficacy of DBS.Evidence obtained using electrophysiology and imaging techniques in both animals and humans suggests that DBS works by modulating neural network activity. Recently, animal studies have shown that stimulation-evoked changes in neurotransmitter release that mirror normal physiology are associated with the therapeutic benefits of DBS. Therefore, to fully understand the neurophysiology of DBS and optimize its efficacy, it may be necessary to look beyond conventional electrophysiological analyses and characterize the neurochemical effects of therapeutic and non-therapeutic stimulation. By combining electrochemical monitoring and mathematical modeling techniques, we can potentially replace the trial-and-error process used in clinical programming with deterministic approaches that help attain optimal and stable neurochemical profiles. In this manuscript, we summarize the current understanding of electrophysiological and electrochemical processing for control of neuromodulation therapies. Additionally, we describe a proof-of-principle closed-loop controller that characterizes DBS-evoked dopamine changes to adjust stimulation parameters in a rodent model of DBS. The work described herein represents the initial steps toward achieving a smart neuroprosthetic system for treatment of neurologic and

  16. Non-invasive brain stimulation for the treatment of symptoms following traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Simarjot K Dhaliwal

    2015-08-01

    Full Text Available Background: Traumatic brain injury (TBI is a common cause of physical, psychological, and cognitive impairment, but many current treatments for TBI are ineffective or produce adverse side effects. Non-invasive methods of brain stimulation could help ameliorate some common trauma-induced symptoms.Objective: This review summarizes instances in which repetitive Transcranial Magnetic Stimulation (rTMS and transcranial Direct Current Stimulation (tDCS have been used to treat symptoms following a traumatic brain injury. A subsequent discussion attempts to determine the value of these methods in light of their potential risks.Methods: The research databases of PubMed/MEDLINE and PsycINFO were electronically searched using terms relevant to the use of rTMS and tDCS as a tool to decrease symptoms in the context of rehabilitation post-TBI.Results: Eight case-studies and four multi-subject reports using rTMS and six multi-subject studies using tDCS were found. Two instances of seizure are discussed. Conclusions: There is evidence that rTMS can be an effective treatment option for some post-TBI symptoms such as depression, tinnitus, and neglect. Although the safety of this method remains uncertain, the use of rTMS in cases of mild-TBI without obvious structural damage may be justified. Evidence on the effectiveness of tDCS is mixed, highlighting the need for additional

  17. Finite element modeling and in vivo analysis of electrode configurations for selective stimulation of pudendal afferent fibers

    Directory of Open Access Journals (Sweden)

    Grill Warren M

    2010-05-01

    Full Text Available Abstract Background Intraurethral electrical stimulation (IES of pudendal afferent nerve fibers can evoke both excitatory and inhibitory bladder reflexes in cats. These pudendovesical reflexes are a potential substrate for restoring bladder function in persons with spinal cord injury or other neurological disorders. However, the complex distribution of pudendal afferent fibers along the lower urinary tract presents a challenge when trying to determine the optimal geometry and position of IES electrodes for evoking these reflexes. This study aimed to determine the optimal intraurethral electrode configuration(s and locations for selectively activating targeted pudendal afferents to aid future preclinical and clinical investigations. Methods A finite element model (FEM of the male cat urethra and surrounding structures was generated to simulate IES with a variety of electrode configurations and locations. The activating functions (AFs along pudendal afferent branches innervating the cat urethra were determined. Additionally, the thresholds for activation of pudendal afferent branches were measured in α-chloralose anesthetized cats. Results Maximum AFs evoked by intraurethral stimulation in the FEM and in vivo threshold intensities were dependent on stimulation location and electrode configuration. Conclusions A ring electrode configuration is ideal for IES. Stimulation near the urethral meatus or prostate can activate the pudendal afferent fibers at the lowest intensities, and allowed selective activation of the dorsal penile nerve or cranial sensory nerve, respectively. Electrode location was a more important factor than electrode configuration for determining stimulation threshold intensity and nerve selectivity.

  18. Effects of thalamic deep brain stimulation on spontaneous language production.

    Science.gov (United States)

    Ehlen, Felicitas; Vonberg, Isabelle; Kühn, Andrea A; Klostermann, Fabian

    2016-08-01

    The thalamus is thought to contribute to language-related processing, but specifications of this notion remain vague. An assessment of potential effects of thalamic deep brain stimulation (DBS) on spontaneous language may help to delineate respective functions. For this purpose, we analyzed spontaneous language samples from thirteen (six female / seven male) patients with essential tremor treated with DBS of the thalamic ventral intermediate nucleus (VIM) in their respective ON vs. OFF conditions. Samples were obtained from semi-structured interviews and examined on multidimensional linguistic levels. In the VIM-DBS ON condition, participants used a significantly higher proportion of paratactic as opposed to hypotactic sentence structures. This increase correlated negatively with the change in the more global cognitive score, which in itself did not change significantly. In conclusion, VIM-DBS appears to induce the use of a simplified syntactic structure. The findings are discussed in relation to concepts of thalamic roles in language-related cognitive behavior. PMID:27267813

  19. The practices of do-it-yourself brain stimulation: implications for ethical considerations and regulatory proposals.

    Science.gov (United States)

    Wexler, Anna

    2016-04-01

    Scientists and neuroethicists have recently drawn attention to the ethical and regulatory issues surrounding the do-it-yourself (DIY) brain stimulation community, which comprises individuals stimulating their own brains with transcranial direct current stimulation (tDCS) for self-improvement. However, to date, existing regulatory proposals and ethical discussions have been put forth without engaging those involved in the DIY tDCS community or attempting to understand the nature of their practices. I argue that to better contend with the growing ethical and safety concerns surrounding DIY tDCS, we need to understand the practices of the community. This study presents the results of a preliminary inquiry into the DIY tDCS community, with a focus on knowledge that is formed, shared and appropriated within it. I show that when making or acquiring a device, DIYers (as some members call themselves) produce a body of knowledge that is completely separate from that of the scientific community, and share it via online forums, blogs, videos and personal communications. However, when applying tDCS, DIYers draw heavily on existing scientific knowledge, posting links to academic journal articles and scientific resources and adopting the standardised electrode placement system used by scientists. Some DIYers co-opt scientific knowledge and modify it by creating their own manuals and guides based on published papers. Finally, I explore how DIYers cope with the methodological limitations inherent in self-experimentation. I conclude by discussing how a deeper understanding of the practices of DIY tDCS has important regulatory and ethical implications. PMID:26324456

  20. The present indication and future of deep brain stimulation.

    Science.gov (United States)

    Sugiyama, Kenji; Nozaki, Takao; Asakawa, Tetsuya; Koizumi, Shinichiro; Saitoh, Osamu; Namba, Hiroki

    2015-01-01

    The use of electrical stimulation to treat pain in human disease dates back to ancient Rome or Greece. Modern deep brain stimulation (DBS) was initially applied for pain treatment in the 1960s, and was later used to treat movement disorders in the 1990s. After recognition of DBS as a therapy for central nervous system (CNS) circuit disorders, DBS use showed drastic increase in terms of adaptability to disease and the patient's population. More than 100,000 patients have received DBS therapy worldwide. The established indications for DBS are Parkinson's disease, tremor, and dystonia, whereas global indications of DBS expanded to other neuronal diseases or disorders such as neuropathic pain, epilepsy, and tinnitus. DBS is also experimentally used to manage cognitive disorders and psychiatric diseases such as major depression, obsessive-compulsive disorder (OCD), Tourette's syndrome, and eating disorders. The importance of ethics and conflicts surrounding the regulation and freedom of choice associated with the application of DBS therapy for new diseases or disorders is increasing. These debates are centered on the use of DBS to treat new diseases and disorders as well as its potential to enhance ability in normal healthy individuals. Here we present three issues that need to be addressed in the future: (1) elucidation of the mechanisms of DBS, (2) development of new DBS methods, and (3) miniaturization of the DBS system. With the use of DBS, functional neurosurgery entered into the new era that man can manage and control the brain circuit to treat intractable neuronal diseases and disorders. PMID:25925757

  1. Water diffusion reveals networks that modulate multiregional morphological plasticity after repetitive brain stimulation

    Science.gov (United States)

    Abe, Mitsunari; Fukuyama, Hidenao; Mima, Tatsuya

    2014-01-01

    Repetitive brain stimulation protocols induce plasticity in the stimulated site in brain slice models. Recent evidence from network models has indicated that additional plasticity-related changes occur in nonstimulated remote regions. Despite increasing use of brain stimulation protocols in experimental and clinical settings, the neural substrates underlying the additional effects in remote regions are unknown. Diffusion-weighted MRI (DWI) probes water diffusion and can be used to estimate morphological changes in cortical tissue that occur with the induction of plasticity. Using DWI techniques, we estimated morphological changes induced by application of repetitive transcranial magnetic stimulation (rTMS) over the left primary motor cortex (M1). We found that rTMS altered water diffusion in multiple regions including the left M1. Notably, the change in water diffusion was retained longest in the left M1 and remote regions that had a correlation of baseline fluctuations in water diffusion before rTMS. We conclude that synchronization of water diffusion at rest between stimulated and remote regions ensures retention of rTMS-induced changes in water diffusion in remote regions. Synchronized fluctuations in the morphology of cortical microstructures between stimulated and remote regions might identify networks that allow retention of plasticity-related morphological changes in multiple regions after brain stimulation protocols. These results increase our understanding of the effects of brain stimulation-induced plasticity on multiregional brain networks. DWI techniques could provide a tool to evaluate treatment effects of brain stimulation protocols in patients with brain disorders. PMID:24619090

  2. Moving Forward by Stimulating the Brain: Transcranial Direct Current Stimulation in Post-Stroke Hemiparesis

    Science.gov (United States)

    Peters, Heather T.; Edwards, Dylan J.; Wortman-Jutt, Susan; Page, Stephen J.

    2016-01-01

    Stroke remains a leading cause of disability worldwide, with a majority of survivors experiencing long term decrements in motor function that severely undermine quality of life. While many treatment approaches and adjunctive strategies exist to remediate motor impairment, many are only efficacious or feasible for survivors with active hand and wrist function, a population who constitute only a minority of stroke survivors. Transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation, has been increasingly utilized to increase motor function following stroke as it is able to be used with stroke survivors of varying impairment levels, is portable, is relatively inexpensive and has few side effects and contraindications. Accordingly, in recent years the number of studies investigating its efficacy when utilized as an adjunct to motor rehabilitation regimens has drastically increased. While many of these trials have reported positive and promising efficacy, methodologies vary greatly between studies, including differences in stimulation parameters, outcome measures and the nature of physical practice. As such, an urgent need remains, centering on the need to investigate these methodological differences and synthesize the most current evidence surrounding the application of tDCS for post-stroke motor rehabilitation. Accordingly, the purpose of this paper is to provide a detailed overview of the most recent tDCS literature (published 2014-2015), while highlighting these variations in methodological approach, as well to elucidate the mechanisms associated with tDCS and post-stroke motor re-learning and neuroplasticity. PMID:27555811

  3. Moving Forward by Stimulating the Brain: Transcranial Direct Current Stimulation in Post-Stroke Hemiparesis.

    Science.gov (United States)

    Peters, Heather T; Edwards, Dylan J; Wortman-Jutt, Susan; Page, Stephen J

    2016-01-01

    Stroke remains a leading cause of disability worldwide, with a majority of survivors experiencing long term decrements in motor function that severely undermine quality of life. While many treatment approaches and adjunctive strategies exist to remediate motor impairment, many are only efficacious or feasible for survivors with active hand and wrist function, a population who constitute only a minority of stroke survivors. Transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation, has been increasingly utilized to increase motor function following stroke as it is able to be used with stroke survivors of varying impairment levels, is portable, is relatively inexpensive and has few side effects and contraindications. Accordingly, in recent years the number of studies investigating its efficacy when utilized as an adjunct to motor rehabilitation regimens has drastically increased. While many of these trials have reported positive and promising efficacy, methodologies vary greatly between studies, including differences in stimulation parameters, outcome measures and the nature of physical practice. As such, an urgent need remains, centering on the need to investigate these methodological differences and synthesize the most current evidence surrounding the application of tDCS for post-stroke motor rehabilitation. Accordingly, the purpose of this paper is to provide a detailed overview of the most recent tDCS literature (published 2014-2015), while highlighting these variations in methodological approach, as well to elucidate the mechanisms associated with tDCS and post-stroke motor re-learning and neuroplasticity. PMID:27555811

  4. Systematic Review of Parameters of Stimulation: Clinical Trial Design Characteristics and Motor Outcomes in Noninvasive Brain Stimulation in Stroke

    OpenAIRE

    BamideleOyebamijiAdeyemo

    2012-01-01

    Introduction: Repetitive Transcranial Magnetic Stimulation (rTMS) and Transcranial Direct Current Stimulation are two powerful non-invasive neuromodulatory therapies that have the potential to alter and evaluate the integrity of the corticospinal tract. Moreover, recent evidence has shown that brain stimulation might be beneficial in stroke recovery. Therefore, investigating and investing in innovative therapies that may improve neurorehabilitative stroke recovery are next steps in research a...

  5. Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology.

    Science.gov (United States)

    Ho, Allen L; Erickson-Direnzo, Elizabeth; Pendharkar, Arjun V; Sung, Chih-Kwang; Halpern, Casey H

    2015-06-01

    Tremulous voice is a characteristic feature of a multitude of movement disorders, but when it occurs in individuals diagnosed with essential tremor, it is referred to as essential vocal tremor (EVT). For individuals with EVT, their tremulous voice is associated with significant social embarrassment and in severe cases may result in the discontinuation of employment and hobbies. Management of EVT is extremely difficult, and current behavioral and medical interventions for vocal tremor result in suboptimal outcomes. Deep brain stimulation (DBS) has been proposed as a potential therapeutic avenue for EVT, but few studies can be identified that have systematically examined improvements in EVT following DBS. The authors describe a case of awake bilateral DBS targeting the ventral intermediate nucleus for a patient suffering from severe voice and arm tremor. They also present their comprehensive, multidisciplinary methodology for definitive treatment of EVT via DBS. To the authors' knowledge, this is the first time comprehensive intraoperative voice evaluation has been used to guide microelectrode/stimulator placement, as well as the first time that standard pre- and post-DBS assessments have been conducted, demonstrating the efficacy of this tailored DBS approach. PMID:26030706

  6. Influence of implantation on the electrochemical properties of smooth and porous TiN coatings for stimulation electrodes

    DEFF Research Database (Denmark)

    Meijs, S.; Sørensen, C.; Sørensen, S.; Rechendorff, K.; Fjorback, M.; Rijkhoff, N. J. M.

    2016-01-01

    OBJECTIVE: To determine whether changes in electrochemical properties of porous titanium nitride (TiN) electrodes as a function of time after implantation are different from those of smooth TiN electrodes. APPROACH: Eight smooth and 8 porous TiN coated electrodes were implanted in 8 rats. Before...... implantation, voltage transients, cyclic voltammograms and impedance spectra were recorded in phosphate buffered saline (PBS). After implantation, these measurements were done weekly to investigate how smooth and porous electrodes were affected by implantation. MAIN RESULTS: The electrode capacitance of the...... porous TiN electrodes decreased more than the capacitance of the smooth electrodes due to acute implantation under fast measurement conditions (such as stimulation pulses). This indicates that protein adhesion presents a greater diffusion limitation for counter-ions for the porous than for the smooth...

  7. Modulation of large-scale brain networks by transcranial direct current stimulation evidenced by resting-state functional MRI

    Science.gov (United States)

    Peña-Gómez, Cleofé; Sala-Lonch, Roser; Junqué, Carme; Clemente, Immaculada C.; Vidal, Dídac; Bargalló, Núria; Falcón, Carles; Valls-Solé, Josep; Pascual-Leone, Álvaro; Bartrés-Faz, David

    2013-01-01

    Background Brain areas interact mutually to perform particular complex brain functions such as memory or language. Furthermore, under resting-state conditions several spatial patterns have been identified that resemble functional systems involved in cognitive functions. Among these, the default-mode network (DMN), which is consistently deactivated during task periods and is related to a variety of cognitive functions, has attracted most attention. In addition, in resting-state conditions some brain areas engaged in focused attention (such as the anticorrelated network, AN) show a strong negative correlation with DMN; as task demand increases, AN activity rises, and DMN activity falls. Objective We combined transcranial direct current stimulation (tDCS) with functional magnetic resonance imaging (fMRI) to investigate these brain network dynamics. Methods Ten healthy young volunteers underwent four blocks of resting-state fMRI (10-minutes), each of them immediately after 20 minutes of sham or active tDCS (2 mA), on two different days. On the first day the anodal electrode was placed over the left dorsolateral prefrontal cortex (DLPFC) (part of the AN) with the cathode over the contralateral supraorbital area, and on the second day, the electrode arrangement was reversed (anode right-DLPFC, cathode left-supraorbital). Results After active stimulation, functional network connectivity revealed increased synchrony within the AN components and reduced synchrony in the DMN components. Conclusions Our study reveals a reconfiguration of intrinsic brain activity networks after active tDCS. These effects may help to explain earlier reports of improvements in cognitive functions after anodal-tDCS, where increasing cortical excitability may have facilitated reconfiguration of functional brain networks to address upcoming cognitive demands. PMID:21962981

  8. Deep brain stimulation for severe autism: from pathophysiology to procedure.

    Science.gov (United States)

    Sinha, Saurabh; McGovern, Robert A; Sheth, Sameer A

    2015-06-01

    Autism is a heterogeneous neurodevelopmental disorder characterized by early-onset impairment in social interaction and communication and by repetitive, restricted behaviors and interests. Because the degree of impairment may vary, a spectrum of clinical manifestations exists. Severe autism is characterized by complete lack of language development and potentially life-threatening self-injurious behavior, the latter of which may be refractory to medical therapy and devastating for affected individuals and their caretakers. New treatment strategies are therefore needed. Here, the authors propose deep brain stimulation (DBS) of the basolateral nucleus of the amygdala (BLA) as a therapeutic intervention to treat severe autism. The authors review recent developments in the understanding of the pathophysiology of autism. Specifically, they describe the genetic and environmental alterations that affect neurodevelopment. The authors also highlight the resultant microstructural, macrostructural, and functional abnormalities that emerge during brain development, which create a pattern of dysfunctional neural networks involved in socioemotional processing. They then discuss how these findings implicate the BLA as a key node in the pathophysiology of autism and review a reported case of BLA DBS for treatment of severe autism. Much progress has been made in recent years in understanding the pathophysiology of autism. The BLA represents a logical neurosurgical target for treating severe autism. Further study is needed that considers mechanistic and operative challenges. PMID:26030703

  9. Enhanced tissue integration of implantable electrodes for sensing, and stimulation, via radio frequency glow discharge

    Science.gov (United States)

    O'Connor, Laurie M.

    Biopotential electrodes are conductive materials that convert electronic currents to or from ionic currents for sensing, and stimulating specific tissue sites for medical applications. Implanted electrodes become "walled off" by the foreign body tissue reactions producing poorly attached scar capsules dominated by surrounding dense collagenous lamellae and source fibroblasts which are electrically resistive. The conductive interstitial fluid that is typical between an electrode and the resistive capsule allows spurious current paths. The insulating layer increases the distance between the electrode and the target sites and poor attachment often results in electrode migration within the host tissue. This investigation tested the hypothesis that surface-energy modulation of electrodes, via Radio Frequency Glow Discharge Treatment (RFGDT), can improve the performance of tissue-implantable electrodes by reducing the foreign body tissue reaction and enhancing interfacial bonding between the tissue and electrode material. Previously published findings were reproduced in a pilot study of explanted reference grade medical-grade methyl silicone (PDMS) and commercially pure titanium (cpTi) materials and their tissue capsules from 30-day subcutaneous exposures in Balb/C mice. The low-critical surface tension PDMS produced thick, dense, poorly attached scar capsules while the higher-surface-energy commercially pure titanium (cpTi) produced more cellular and strongly attached tissue layers difficult to delaminate from the biomaterial. For the main body of work, cpTi, capacitor-grade Tantalum (Ta), and synthetic heart valve-quality Pyrolytic Carbon (PyC) were evaluated, representative of potential high-surface-energy implant electrode materials. Their surface characteristics were determined as-manufactured and after Radio Frequency Glow Discharge Treatment (RFGDT) by Critical Surface Tension (CST) measurement, Scanning Electron Microscopy (SEM), Energy Dispersive X

  10. Detection of spreading depolarization with intraparenchymal electrodes in the injured human brain

    DEFF Research Database (Denmark)

    Jeffcote, Toby; Hinzman, Jason M; Jewell, Sharon L;

    2014-01-01

    BACKGROUND: Spreading depolarization events following ischemic and traumatic brain injury are associated with poor patient outcome. Currently, monitoring these events is limited to patients in whom subdural electrodes can be placed at open craniotomy. This study examined whether these events can be...... detected using intra-cortical electrodes, opening the way for electrode insertion via burr hole. METHODS: Animal work was carried out on adult Sprague-Dawley rats in a laboratory setting to investigate the feasibility of recording depolarization events. Subsequently, 8 human patients requiring craniotomy...... for traumatic brain injury or aneurysmal subarachnoid hemorrhage were monitored for depolarization events in an intensive care setting with concurrent strip (subdural) and depth (intra-parenchymal) electrode recordings. RESULTS: (1) Depolarization events can be reliably detected from intra...

  11. Resting-state networks link invasive and noninvasive brain stimulation across diverse psychiatric and neurological diseases.

    Science.gov (United States)

    Fox, Michael D; Buckner, Randy L; Liu, Hesheng; Chakravarty, M Mallar; Lozano, Andres M; Pascual-Leone, Alvaro

    2014-10-14

    Brain stimulation, a therapy increasingly used for neurological and psychiatric disease, traditionally is divided into invasive approaches, such as deep brain stimulation (DBS), and noninvasive approaches, such as transcranial magnetic stimulation. The relationship between these approaches is unknown, therapeutic mechanisms remain unclear, and the ideal stimulation site for a given technique is often ambiguous, limiting optimization of the stimulation and its application in further disorders. In this article, we identify diseases treated with both types of stimulation, list the stimulation sites thought to be most effective in each disease, and test the hypothesis that these sites are different nodes within the same brain network as defined by resting-state functional-connectivity MRI. Sites where DBS was effective were functionally connected to sites where noninvasive brain stimulation was effective across diseases including depression, Parkinson's disease, obsessive-compulsive disorder, essential tremor, addiction, pain, minimally conscious states, and Alzheimer's disease. A lack of functional connectivity identified sites where stimulation was ineffective, and the sign of the correlation related to whether excitatory or inhibitory noninvasive stimulation was found clinically effective. These results suggest that resting-state functional connectivity may be useful for translating therapy between stimulation modalities, optimizing treatment, and identifying new stimulation targets. More broadly, this work supports a network perspective toward understanding and treating neuropsychiatric disease, highlighting the therapeutic potential of targeted brain network modulation. PMID:25267639

  12. Improved Efficacy of Temporally Non-Regular Deep Brain Stimulation in Parkinson's Disease

    OpenAIRE

    Brocker, David T.; Swan, Brandon D; Turner, Dennis A.; Gross, Robert E.; Tatter, Stephen B.; Koop, Mandy Miller; Bronte-Stewart, Helen; Grill, Warren M.

    2012-01-01

    High frequency deep brain stimulation is an effective therapy for motor symptoms in Parkinson's disease. However, the relative clinical efficacy of regular versus non-regular temporal patterns of stimulation in Parkinson's disease remains unclear. To determine the temporal characteristics of non-regular temporal patterns of stimulation important for treatment of Parkinson's disease, we compared the efficacy of temporally regular stimulation with four non-regular patterns of stimulation in sub...

  13. Active books: the design of an implantable stimulator that minimizes cable count using integrated circuits very close to electrodes.

    Science.gov (United States)

    Liu, Xiao; Demosthenous, Andreas; Vanhoestenberghe, Anne; Jiang, Dai; Donaldson, Nick

    2012-06-01

    This paper presents an integrated stimulator that can be embedded in implantable electrode books for interfacing with nerve roots at the cauda equina. The Active Book overcomes the limitation of conventional nerve root stimulators which can only support a small number of stimulating electrodes due to cable count restriction through the dura. Instead, a distributed stimulation system with many tripole electrodes can be configured using several Active Books which are addressed sequentially. The stimulator was fabricated in a 0.6-μm high-voltage CMOS process and occupies a silicon area of 4.2 × 6.5 mm(2). The circuit was designed to deliver up to 8 mA stimulus current to tripole electrodes from an 18 V power supply. Input pad count is limited to five (two power and three control lines) hence requiring a specific procedure for downloading stimulation commands to the chip and extracting information from it. Supported commands include adjusting the amplitude of stimulus current, varying the current ratio at the two anodes in each channel, and measuring relative humidity inside the chip package. In addition to stimulation mode, the chip supports quiescent mode, dissipating less than 100 nA current from the power supply. The performance of the stimulator chip was verified with bench tests including measurements using tripoles in saline. PMID:23853144

  14. Comparative analysis of transverse intrafascicular multichannel, longitudinal intrafascicular and multipolar cuff electrodes for the selective stimulation of nerve fascicles

    Science.gov (United States)

    Badia, Jordi; Boretius, Tim; Andreu, David; Azevedo-Coste, Christine; Stieglitz, Thomas; Navarro, Xavier

    2011-06-01

    The selection of a suitable nerve electrode for neuroprosthetic applications implies a trade-off between invasiveness and selectivity, wherein the ultimate goal is achieving the highest selectivity for a high number of nerve fascicles by the least invasiveness and potential damage to the nerve. The transverse intrafascicular multichannel electrode (TIME) is intended to be transversally inserted into the peripheral nerve and to be useful to selectively activate subsets of axons in different fascicles within the same nerve. We present a comparative study of TIME, LIFE and multipolar cuff electrodes for the selective stimulation of small nerves. The electrodes were implanted on the rat sciatic nerve, and the activation of gastrocnemius, plantar and tibialis anterior muscles was recorded by EMG signals. Thus, the study allowed us to ascertain the selectivity of stimulation at the interfascicular and also at the intrafascicular level. The results of this study indicate that (1) intrafascicular electrodes (LIFE and TIME) provide excitation circumscribed to the implanted fascicle, whereas extraneural electrodes (cuffs) predominantly excite nerve fascicles located superficially; (2) the minimum threshold for muscle activation with TIME and LIFE was significantly lower than with cuff electrodes; (3) TIME allowed us to selectively activate the three tested muscles when stimulating through different active sites of one device, both at inter- and intrafascicular levels, whereas selective activation using multipolar cuff (with a longitudinal tripolar stimulation configuration) was only possible for two muscles, at the interfascicular level, and LIFE did not activate selectively more than one muscle in the implanted nerve fascicle.

  15. Evaluation of poly(3,4-ethylenedioxythiophene)/carbon nanotube neural electrode coatings for stimulation in the dorsal root ganglion

    Science.gov (United States)

    Kolarcik, Christi L.; Catt, Kasey; Rost, Erika; Albrecht, Ingrid N.; Bourbeau, Dennis; Du, Zhanhong; Kozai, Takashi D. Y.; Luo, Xiliang; Weber, Douglas J.; Cui, X. Tracy

    2015-02-01

    Objective. The dorsal root ganglion is an attractive target for implanting neural electrode arrays that restore sensory function or provide therapy via stimulation. However, penetrating microelectrodes designed for these applications are small and deliver low currents. For long-term performance of microstimulation devices, novel coating materials are needed in part to decrease impedance values at the electrode-tissue interface and to increase charge storage capacity. Approach. Conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and multi-wall carbon nanotubes (CNTs) were coated on the electrode surface and doped with the anti-inflammatory drug, dexamethasone. Electrode characteristics and the tissue reaction around neural electrodes as a result of stimulation, coating and drug release were characterized. Hematoxylin and eosin staining along with antibodies recognizing Iba1 (microglia/macrophages), NF200 (neuronal axons), NeuN (neurons), vimentin (fibroblasts), caspase-3 (cell death) and L1 (neural cell adhesion molecule) were used. Quantitative image analyses were performed using MATLAB. Main results. Our results indicate that coated microelectrodes have lower in vitro and in vivo impedance values. Significantly less neuronal death/damage was observed with coated electrodes as compared to non-coated controls. The inflammatory response with the PEDOT/CNT-coated electrodes was also reduced. Significance. This study is the first to report on the utility of these coatings in stimulation applications. Our results indicate PEDOT/CNT coatings may be valuable additions to implantable electrodes used as therapeutic modalities.

  16. Effects of Intramuscular Electrical Stimulation Using Inversely Placed Electrodes on Myofascial Pain Syndrome in the Shoulder: A Case Series.

    Science.gov (United States)

    Shanmugam, Sukumar; Mathias, Lawrence; Thakur, Ajay; Kumar, Dhanesh

    2016-04-01

    Myofascial pain syndrome (MPS) is one of the common musculoskeletal conditions of the shoulder which may develop sensory-motor and autonomic dysfunctions at the various level of the neuromuscular system. The pain and dysfunction caused by MPS were primarily treated with physical therapy and pharmacological agents in order to achieve painfree movements. However, in recent years intramuscular electrical stimulation (IMES) with conventional electrode placement was used by researchers to maximise therapeutic values. But, in this study an inverse electrode placement was used to deliver electrical impulses intramuscularly to achieve neuro-modulation at the various level of the nervous system. Nine patients with MPS were treated with intramuscular electrode stimulation using inversely placed electrodes for a period of three weeks. All nine subjects recovered from their shoulder pain and disability within the few weeks of intervention. So, this inverse electrode placement may be more appropriate for chronic pain management. PMID:27103970

  17. Iridium oxide deposited by pulsed dc-sputtering for stimulation electrodes

    International Nuclear Information System (INIS)

    A pulsed-dc reactive sputtering technique was used for iridium oxide thin-film deposition. Pulsing frequency and oxygen flow were varied over several deposition cycles, regarding stimulation electrode applications. Surface and electrochemical analysis were performed for deposition evaluation. The results show the influence of the oxygen flow to the morphology and the electrochemical properties of the reactively sputtered films. Optimal surface structure and electrochemical properties for films deposited at 0.016 mbar working pressure, 100 kHz pulse frequency and 1 µs pulsewidth can be achieved at oxygen flows around 8 to 10 sccm

  18. Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves

    DEFF Research Database (Denmark)

    Rossini, P M; Burke, D; Chen, R;

    2015-01-01

    whom were in the panel of the 1994 "Report", was selected to produce a current state-of-the-art review of non-invasive stimulation both for clinical application and research in neuroscience. Since 1994, the international scientific community has seen a rapid increase in non-invasive brain stimulation...... of non-invasive brain stimulation, especially for TMS. Recent guidelines can be found in the literature covering specific aspects of non-invasive brain stimulation, such as safety (Rossi et al., 2009), methodology (Groppa et al., 2012) and therapeutic applications (Lefaucheur et al., 2014). This up...

  19. Effect of deep brain stimulation on substantia nigra neurons in a rat model of Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    WU Sheng-tian; MA Yu; ZHANG Kai; ZHANG Jian-guo

    2012-01-01

    Background Parkinson's disease(PD)is a common neurodegenerative disease,which occurs mainly in the elderly.Recent studies have demonstrated that apoptosis plays an important role in the occurrence and development of PD.Subthalamic nucleus deep brain stimulation(STN-DBS)has been recognized as an effective treatment for PD.Recent clinical observations have shown that STN-DBS was able to delay early PD progression,and experiments in animal models have also demonstrated a protective effect of STN-DBS on neurons.However,the correlation between the neuron-protective effect of STN-DBS and the progression of substantia nigra pars compacta(SNc)neuronal apoptosis is still unknown.The aim of this study was to investigate the protective effect and potential mechanism of STN-DBS on SNc neurons in PD rats.Methods After the establishment of a PD rat model by unilateral/2-point injection of 6-hydroxydopamine in the medial forebrain bundle of the brain,DBS by implanting electrodes in the STN was administered.Behavioral changes were observed,and morphological changes of SNc neurons were analyzed by Nissl staining and DNA in situ end-labeling.Through extracellular recording of single neuron discharges and microelectrophoresis,the causes of and changes in SNc excitability during STN-DBS were analyzed,and the protective effect and potential mechanism of action of STN-DBS on SNc neurons in PD rats was investigated.Results SNc neuron apoptosis was significantly decreased(P<0.05)in the stimulation group,compared with the sham stimulation PD group.Spontaneous discharges of SNc neurons were observed in normal rats and PD model rats,and the mean frequency of spontaneous discharges of SNc neurons in normal rats((40.65±11.08)Hz)was higher than that of residual SNc neurons in PD rats((36.71±9.23)Hz).Electrical stimulation of the STN in rats was associated with elevated excitation in unilateral SNc neurons.However,administering the gamma-aminobutyric acid receptor blocker

  20. Reduction in time-to-sleep through EEG based brain state detection and audio stimulation.

    Science.gov (United States)

    Zhuo Zhang; Cuntai Guan; Ti Eu Chan; Juanhong Yu; Aung Aung Phyo Wai; Chuanchu Wang; Haihong Zhang

    2015-08-01

    We developed an EEG- and audio-based sleep sensing and enhancing system, called iSleep (interactive Sleep enhancement apparatus). The system adopts a closed-loop approach which optimizes the audio recording selection based on user's sleep status detected through our online EEG computing algorithm. The iSleep prototype comprises two major parts: 1) a sleeping mask integrated with a single channel EEG electrode and amplifier, a pair of stereo earphones and a microcontroller with wireless circuit for control and data streaming; 2) a mobile app to receive EEG signals for online sleep monitoring and audio playback control. In this study we attempt to validate our hypothesis that appropriate audio stimulation in relation to brain state can induce faster onset of sleep and improve the quality of a nap. We conduct experiments on 28 healthy subjects, each undergoing two nap sessions - one with a quiet background and one with our audio-stimulation. We compare the time-to-sleep in both sessions between two groups of subjects, e.g., fast and slow sleep onset groups. The p-value obtained from Wilcoxon Signed Rank Test is 1.22e-04 for slow onset group, which demonstrates that iSleep can significantly reduce the time-to-sleep for people with difficulty in falling sleep. PMID:26738161

  1. Deep brain stimulation and cognitive decline in Parkinson's disease: The predictive value of electroencephalography.

    Science.gov (United States)

    Markser, A; Maier, Franziska; Lewis, C J; Dembek, T A; Pedrosa, D; Eggers, C; Timmermann, L; Kalbe, E; Fink, G R; Burghaus, Lothar

    2015-10-01

    Some Parkinson's disease (PD) patients treated with subthalamic nucleus deep brain stimulation (STN-DBS) develop new-onset cognitive decline. We examined whether clinical EEG recordings can be used to predict cognitive deterioration in PD patients undergoing STN-DBS. In this retrospective study, we used the Grand Total EEG (GTE)-score (short and total) to evaluate pre- and postoperative EEGs. In PD patients undergoing STN-DBS (N = 30), cognitive functioning was measured using Mini-Mental State Test and DemTect before and after surgery. Severity of motor impairment was assessed using the Unified Parkinson's Disease Rating Scale-III. Patients were classified into patients with or without cognitive decline after STN-DBS surgery. Epidemiological data, pre- and postoperative EEG recordings as well as neuropsychological and neurological data, electrode positions and the third ventricle width were compared. A logistic regression model was used to identify predictors of cognitive decline. Motor deficits significantly improved from pre- to post-surgery, while the mean GTE-scores increased significantly. Six patients developed cognitive deterioration 4-12 months postoperatively. These patients had significantly higher preoperative GTE-scores than patients without cognitive deterioration, although preoperative cognitive functioning was comparable. Electrode positions, brain atrophy and neurological data did not differ between groups. Logistic regression analysis identified the GTE-score as a significant predictor of postoperative cognitive deterioration. Data suggest that the preoperative GTE-score can be used to identify PD patients that are at high risk for developing cognitive deterioration after STN-DBS surgery even though their preoperative cognitive state was normal. PMID:26159102

  2. The effect of electrode return configuration on multi-unit activity of the visual cortex from supra choroidal electrical stimulation

    International Nuclear Information System (INIS)

    Full text: To compare differences in thresholds and spatial selec tivity of various electrode return configurations using multi-unit cortical activity in response to electrical stimulation of a supracho roidal retinal prosthesis. Methods A polyimide substrate flexible platinum electrode array was inserted into the suprachoroidal space of normally sighted anaesthe tised cats (n 8). lndividual electrodes were electrically stimulated with biphasic, cathodic first CUITent pulses (500 lS per phase, 0-725 pAl using monopolar, hexagonal and common ground stimulation. Multi-unit activity was recorded with a 32-channel array inserted into the exposed primary visual cortex. Results Both, monopolar and hexagonal stimulation elicited cortical activity with significantly lower thresholds (monopolar, 69 27 nC; hexagonal, 86 15 nC) than common ground stimulation (J 53 15 nC), however no significant difference was found between the thresholds for monopolar and hexagonal stimulation (One way RM-ANOYA, p < 0.00 I; Pairwise multiple comparisons, Tukey test). Further, cortical thresholds increased by 58 nC for the mon polar return, 79 nC for the hexagonal return, and II nC for the common ground return for every I mm change in retinal stimulating position from the retinal position that elicited the lowest cortical threshold. Conclusion A successful retinal prosthesis will need to produce discrete phosphenes at charge levels which will not harm the retina or the stimulating electrodes. Our data shows that hexagonal stimulation is efficient in inducing cortical activity both with lower charge thresholds and a higher degree of spatial selectivity compared to monopolar and common ground stimulation. Our results suggest that hexagonal stimulation is the ideal mode of stimulation for a retinal prosthesis.

  3. Health, Happiness and Human Enhancement-Dealing with Unexpected Effects of Deep Brain Stimulation.

    Science.gov (United States)

    Schermer, Maartje

    2013-01-01

    Deep Brain Stimulation (DBS) is a treatment involving the implantation of electrodes into the brain. Presently, it is used for neurological disorders like Parkinson's disease, but indications are expanding to psychiatric disorders such as depression, addiction and Obsessive Compulsive Disorder (OCD). Theoretically, it may be possible to use DBS for the enhancement of various mental functions. This article discusses a case of an OCD patient who felt very happy with the DBS treatment, even though her symptoms were not reduced. First, it is explored if the argument that 'doctors are not in the business of trading happiness', as used by her psychiatrist to justify his discontinuation of the DBS treatment, holds. The relationship between enhancement and the goals of medicine is discussed and it is concluded that even though the goals of medicine do not set strict limits and may even include certain types of enhancement, there are some good reasons for limiting the kind of things doctors are required or allowed to do. Next, the case is discussed from the perspective of beneficence and autonomy. It is argued that making people feel good is not the same as enhancing their well-being and that it is unlikely-though not absolutely impossible-that the well-being of the happy OCD patient is really improved. Finally, some concerns regarding the autonomy of a request made under the influence of DBS treatment are considered. PMID:24273618

  4. Transcranial magnetic stimulation of the brain: guidelines for pain treatment research

    OpenAIRE

    Klein, Max M.; Treister, Roi; Raij, Tommi; Pascual-Leone, Alvaro; Park, Lawrence; Nurmikko, Turo; Lenz, Fred; Lefaucheur, Jean-Pascal; Lang, Magdalena; Hallett, Mark; Fox, Michael; Cudkowicz, Merit; Costello, Ann; Daniel B. Carr; Ayache, Samar S.

    2015-01-01

    Abstract Recognizing that electrically stimulating the motor cortex could relieve chronic pain sparked development of noninvasive technologies. In transcranial magnetic stimulation (TMS), electromagnetic coils held against the scalp influence underlying cortical firing. Multiday repetitive transcranial magnetic stimulation (rTMS) can induce long-lasting, potentially therapeutic brain plasticity. Nearby ferromagnetic or electronic implants are contraindications. Adverse effects are minimal, pr...

  5. Deep brain stimulation for psychiatric diseases: what are the risks?

    Science.gov (United States)

    Saleh, Christian; Fontaine, Denys

    2015-05-01

    Despite the application of deep brain stimulation (DBS) as an efficient treatment modality for psychiatric disorders, such as obsessive-compulsive disorder (OCD), Gilles de la Tourette Syndrome (GTS), and treatment refractory major depression (TRD), few patients are operated or included in clinical trials, often for fear of the potential risks of an approach deemed too dangerous. To assess the surgical risks, we conducted an analysis of publications on DBS for psychiatric disorders. A PubMed search was conducted on reports on DBS for OCD, GTS, and TRD. Forty-nine articles were included. Only reports on complications related to DBS were selected and analyzed. Two hundred seventy-two patients with a mean follow-up of 22 months were included in our analysis. Surgical mortality was nil. The overall mortality was 1.1 %: two suicides were unrelated to DBS and one death was reported to be unlikely due to DBS. The majority of complications were transient and related to stimulation. Long-term morbidity occurred in 16.5 % of cases. Three patients had permanent neurological complications due to intracerebral hemorrhage (2.2 %). Complications reported in DBS for psychiatric diseases appear to be similar to those reported for DBS in movement disorders. But class I evidence is lacking. Our analysis was based mainly on small non-randomized studies. A significant number of patients (approximately 150 patients) who were treated with DBS for psychiatric diseases had to be excluded from our analysis as no data on complications was available. The exact prevalence of complications of DBS in psychiatric diseases could not be established. DBS for psychiatric diseases is promising, but remains an experimental technique in need of further evaluation. A close surveillance of patients undergoing DBS for psychiatric diseases is mandatory. PMID:25795265

  6. Embedded Ultrathin Cluster Electrodes for Long-Term Recordings in Deep Brain Centers

    Science.gov (United States)

    Thorbergsson, Palmi Thor; Ekstrand, Joakim; Friberg, Annika; Granmo, Marcus; Pettersson, Lina M. E.; Schouenborg, Jens

    2016-01-01

    Neural interfaces which allow long-term recordings in deep brain structures in awake freely moving animals have the potential of becoming highly valuable tools in neuroscience. However, the recording quality usually deteriorates over time, probably at least partly due to tissue reactions caused by injuries during implantation, and subsequently micro-forces due to a lack of mechanical compliance between the tissue and neural interface. To address this challenge, we developed a gelatin embedded neural interface comprising highly flexible electrodes and evaluated its long term recording properties. Bundles of ultrathin parylene C coated platinum electrodes (N = 29) were embedded in a hard gelatin based matrix shaped like a needle, and coated with Kollicoat™ to retard dissolution of gelatin during the implantation. The implantation parameters were established in an in vitro model of the brain (0.5% agarose). Following a craniotomy in the anesthetized rat, the gelatin embedded electrodes were stereotactically inserted to a pre-target position, and after gelatin dissolution the electrodes were further advanced and spread out in the area of the subthalamic nucleus (STN). The performance of the implanted electrodes was evaluated under anesthesia, during 8 weeks. Apart from an increase in the median-noise level during the first 4 weeks, the electrode impedance and signal-to-noise ratio of single-units remained stable throughout the experiment. Histological postmortem analysis confirmed implantation in the area of STN in most animals. In conclusion, by combining novel biocompatible implantation techniques and ultra-flexible electrodes, long-term neuronal recordings from deep brain structures with no significant deterioration of electrode function were achieved. PMID:27159159

  7. Hypothalamic deep brain stimulation reduces weight gain in an obesity-animal model.

    Science.gov (United States)

    Melega, William P; Lacan, Goran; Gorgulho, Alessandra A; Behnke, Eric J; De Salles, Antonio A F

    2012-01-01

    Prior studies of appetite regulatory networks, primarily in rodents, have established that targeted electrical stimulation of ventromedial hypothalamus (VMH) can alter food intake patterns and metabolic homeostasis. Consideration of this method for weight modulation in humans with severe overeating disorders and morbid obesity can be further advanced by modeling procedures and assessing endpoints that can provide preclinical data on efficacy and safety. In this study we adapted human deep brain stimulation (DBS) stereotactic methods and instrumentation to demonstrate in a large animal model the modulation of weight gain with VMH-DBS. Female Göttingen minipigs were used because of their dietary habits, physiologic characteristics, and brain structures that resemble those of primates. Further, these animals become obese on extra-feeding regimens. DBS electrodes were first bilaterally implanted into the VMH of the animals (n = 8) which were then maintained on a restricted food regimen for 1 mo following the surgery. The daily amount of food was then doubled for the next 2 mo in all animals to produce obesity associated with extra calorie intake, with half of the animals (n = 4) concurrently receiving continuous low frequency (50 Hz) VMH-DBS. Adverse motoric or behavioral effects were not observed subsequent to the surgical procedure or during the DBS period. Throughout this 2 mo DBS period, all animals consumed the doubled amount of daily food. However, the animals that had received VMH-DBS showed a cumulative weight gain (6.1±0.4 kg; mean ± SEM) that was lower than the nonstimulated VMH-DBS animals (9.4±1.3 kg; p<0.05), suggestive of a DBS-associated increase in metabolic rate. These results in a porcine obesity model demonstrate the efficacy and behavioral safety of a low frequency VMH-DBS application as a potential clinical strategy for modulation of body weight. PMID:22295102

  8. Hypothalamic deep brain stimulation reduces weight gain in an obesity-animal model.

    Directory of Open Access Journals (Sweden)

    William P Melega

    Full Text Available Prior studies of appetite regulatory networks, primarily in rodents, have established that targeted electrical stimulation of ventromedial hypothalamus (VMH can alter food intake patterns and metabolic homeostasis. Consideration of this method for weight modulation in humans with severe overeating disorders and morbid obesity can be further advanced by modeling procedures and assessing endpoints that can provide preclinical data on efficacy and safety. In this study we adapted human deep brain stimulation (DBS stereotactic methods and instrumentation to demonstrate in a large animal model the modulation of weight gain with VMH-DBS. Female Göttingen minipigs were used because of their dietary habits, physiologic characteristics, and brain structures that resemble those of primates. Further, these animals become obese on extra-feeding regimens. DBS electrodes were first bilaterally implanted into the VMH of the animals (n = 8 which were then maintained on a restricted food regimen for 1 mo following the surgery. The daily amount of food was then doubled for the next 2 mo in all animals to produce obesity associated with extra calorie intake, with half of the animals (n = 4 concurrently receiving continuous low frequency (50 Hz VMH-DBS. Adverse motoric or behavioral effects were not observed subsequent to the surgical procedure or during the DBS period. Throughout this 2 mo DBS period, all animals consumed the doubled amount of daily food. However, the animals that had received VMH-DBS showed a cumulative weight gain (6.1±0.4 kg; mean ± SEM that was lower than the nonstimulated VMH-DBS animals (9.4±1.3 kg; p<0.05, suggestive of a DBS-associated increase in metabolic rate. These results in a porcine obesity model demonstrate the efficacy and behavioral safety of a low frequency VMH-DBS application as a potential clinical strategy for modulation of body weight.

  9. Inter-electrode tissue resistance is not affected by tissue oedema when electrically stimulating the lower limb of sepsis patients.

    Science.gov (United States)

    Durfee, William K; Young, Joseph R; Ginz, Hans F

    2014-05-01

    ICU patients typically are given large amounts of fluid and often develop oedema. The purpose of this study was to evaluate whether the oedema would change inter-electrode resistance and, thus, require a different approach to using non-invasive electrical stimulation of nerves to assess muscle force. Inter-electrode tissue resistance in the lower leg was measured by applying a 300 µs constant current pulse and measuring the current through and voltage across the stimulating electrodes. The protocol was administered to nine ICU patients with oedema, eight surgical patients without oedema and eight healthy controls. No significant difference in inter-electrode resistance was found between the three groups. For all groups, resistance decreased as stimulation current increased. In conclusion, inter-electrode resistance in ICU patients with severe oedema is the same as the resistance in regular surgical patients and healthy controls. This means that non-invasive nerve stimulation devices do not need to be designed to accommodate different resistances when used with oedema patients; however, surface stimulation does require higher current levels with oedema patients because of the increased distance between the skin surface and the targeted nerve or muscle. PMID:24758395

  10. Stimulation of brain muscarinic acetylcholine receptors acutely reverses radiogenic hypodipsia

    International Nuclear Information System (INIS)

    A sufficiently large dose of ionizing radiation produces changes in water consumption. However, the direction, durations, and physiological substrates of these alterations remain in question. Here we report a 5-d hypodipsia in rats exposed to 600 rads 60Co but a more transient, albeit larger, reduction in drinking after 1000 60Co. Brain cholinergic neurons have been implicated as mediators of thirst. Therefore, we explored the role of hypothalamic muscarinic receptors in the production of radiation-induced hypodipsia. This was accomplished through the intrahypothalamic injection of carbachol (a muscarinic agonist) or atropine (a muscarinic antagonist) in irradiated rats. Intracranial carbachol produced acute reversal of radiogenic hypodipsia while atropine potentiated the hypodipsia. These post-irradiation drug-induced behaviors were similar to those observed after the same drug treatments before irradiation. Since cholinergic neuronal functions persist and are labile (can be pharmacologically stimulated and blocked) after irradiation, this suggests that other neuronal systems and/or neurochemicals may be more prominently involved in radiogenic hypodipsia

  11. Modulating presence and impulsiveness by external stimulation of the brain

    Directory of Open Access Journals (Sweden)

    Baumgartner Thomas

    2008-08-01

    Full Text Available Abstract Background "The feeling of being there" is one possible way to describe the phenomenon of feeling present in a virtual environment and to act as if this environment is real. One brain area, which is hypothesized to be critically involved in modulating this feeling (also called presence is the dorso-lateral prefrontal cortex (dlPFC, an area also associated with the control of impulsive behavior. Methods In our experiment we applied transcranial direct current stimulation (tDCS to the right dlPFC in order to modulate the experience of presence while watching a virtual roller coaster ride. During the ride we also registered electro-dermal activity. Subjects also performed a test measuring impulsiveness and answered a questionnaire about their presence feeling while they were exposed to the virtual roller coaster scenario. Results Application of cathodal tDCS to the right dlPFC while subjects were exposed to a virtual roller coaster scenario modulates the electrodermal response to the virtual reality stimulus. In addition, measures reflecting impulsiveness were also modulated by application of cathodal tDCS to the right dlPFC. Conclusion Modulating the activation with the right dlPFC results in substantial changes in responses of the vegetative nervous system and changed impulsiveness. The effects can be explained by theories discussing the top-down influence of the right dlPFC on the "impulsive system".

  12. Deep brain stimulation for dystonia: review of the literature.

    Science.gov (United States)

    Mehdorn, Hubertus M

    2016-06-01

    Deep brain stimulation (DBS) has become one of the major therapy options for movement disorders including dystonia. This article should give a review of the current literature from a neurosurgical perspective. Since dystonia is a rare disease, only few studies on larger cohorts have been published, and very few randomized controlled studies are avaialable in the international literature. Our experiences gained treating 134 patients with various types of dystonia, between 1999 and 2015, will serve a guide to interpret the current literature. Symptoms of dystonia are due to a variety of medical conditions. A careful and extensive neurological evaluation is mandatory before medical and surgical treatment options are considered, since the clinical benefits of more aggressive treatment e.g. by DBS depend to a large extent on the etiology of the disease. Diagnostic steps should include also magnetic resonance imaging (MRI) and possibly genetic evaluation. Therapy consists of physiotherapy, medical therapy including botulinum toxin injections in focal dystonia and DBS. This neurosurgical therapy is considered a highly effective therapy in well selected patients, which should be discussed, depending on the etiology, early in the patient's career. Patients with primary dystonia will benefit the most from DBS to the ventromediolateral part of the globus pallidus internus (GPi) with acceptable low complication rates; in order to optimize longterm results in these groups of patient, they will require an interdisciplinary individualized approach both pre- and postoperatively as well as longterm care adjusting to their needs. PMID:26977634

  13. Ipsilateral motor pathways after stroke: implications for noninvasive brain stimulation

    Directory of Open Access Journals (Sweden)

    Lynley V Bradnam

    2013-05-01

    Full Text Available In humans the two cerebral hemispheres have essential roles in controlling the upper limb. The purpose of this article is to draw attention to the potential importance of ipsilateral descending pathways for functional recovery after stroke, and the use of noninvasive brain stimulation (NBS protocols of the contralesional primary motor cortex (M1. Conventionally NBS is used to suppress contralesional M1, and to attenuate transcallosal inhibition onto the ipsilesional M1. There has been little consideration of the fact that contralesional M1 suppression may also reduce excitability of ipsilateral descending pathways that may be important for paretic upper limb control for some patients. One such ipsilateral pathway is the cortico-reticulo-propriospinal pathway (CRPP. In this review we outline a neurophysiological model to explain how contralesional M1 may gain control of the paretic arm via the CRPP. We conclude that the relative importance of the CRPP for motor control in individual patients must be considered before using NBS to suppress contralesional M1. Neurophysiological, neuroimaging and clinical assessments can assist this decision making and facilitate the translation of NBS into the clinical setting.

  14. Influence of implantation on the electrochemical properties of smooth and porous TiN coatings for stimulation electrodes

    Science.gov (United States)

    Meijs, S.; Sørensen, C.; Sørensen, S.; Rechendorff, K.; Fjorback, M.; Rijkhoff, N. J. M.

    2016-04-01

    Objective. To determine whether changes in electrochemical properties of porous titanium nitride (TiN) electrodes as a function of time after implantation are different from those of smooth TiN electrodes. Approach. Eight smooth and 8 porous TiN coated electrodes were implanted in 8 rats. Before implantation, voltage transients, cyclic voltammograms and impedance spectra were recorded in phosphate buffered saline (PBS). After implantation, these measurements were done weekly to investigate how smooth and porous electrodes were affected by implantation. Main results. The electrode capacitance of the porous TiN electrodes decreased more than the capacitance of the smooth electrodes due to acute implantation under fast measurement conditions (such as stimulation pulses). This indicates that protein adhesion presents a greater diffusion limitation for counter-ions for the porous than for the smooth electrodes. The changes in electrochemical properties during the implanted period were similar for smooth and porous TiN electrodes, indicating that cell adhesion poses a similar diffusion limitation for smooth and porous electrodes. Significance. This knowledge can be used to optimize the porous structure of the TiN film, so that the effect of protein adhesion on the electrochemical properties is diminished. Alternatively, an additional coating could be applied on the porous TiN that would prevent or minimize protein adhesion.

  15. Non-invasive brain stimulation of the aging brain: State of the art and future perspectives.

    Science.gov (United States)

    Tatti, Elisa; Rossi, Simone; Innocenti, Iglis; Rossi, Alessandro; Santarnecchi, Emiliano

    2016-08-01

    Favored by increased life expectancy and reduced birth rate, worldwide demography is rapidly shifting to older ages. The golden age of aging is not only an achievement but also a big challenge because of the load of the elderly on social and medical health care systems. Moreover, the impact of age-related decline of attention, memory, reasoning and executive functions on self-sufficiency emphasizes the need of interventions to maintain cognitive abilities at a useful degree in old age. Recently, neuroscientific research explored the chance to apply Non-Invasive Brain Stimulation (NiBS) techniques (as transcranial electrical and magnetic stimulation) to healthy aging population to preserve or enhance physiologically-declining cognitive functions. The present review will update and address the current state of the art on NiBS in healthy aging. Feasibility of NiBS techniques will be discussed in light of recent neuroimaging (either structural or functional) and neurophysiological models proposed to explain neural substrates of the physiologically aging brain. Further, the chance to design multidisciplinary interventions to maximize the efficacy of NiBS techniques will be introduced as a necessary future direction. PMID:27221544

  16. Etanercept Attenuates Traumatic Brain Injury in Rats by Reducing Brain TNF-α Contents and by Stimulating Newly Formed Neurogenesis

    OpenAIRE

    Chong-Un Cheong; Ching-Ping Chang; Chien-Ming Chao; Bor-Chih Cheng; Chung-Zhing Yang; Chung-Ching Chio

    2013-01-01

    It remains unclear whether etanercept penetrates directly into the contused brain and improves the outcomes of TBI by attenuating brain contents of TNF- α and/or stimulating newly formed neurogenesis. Rats that sustained TBI are immediately treated with etanercept. Acute neurological and motor injury is assessed in all rats the day prior to and 7 days after surgery. The numbers of the colocalizations of 5-bromodeoxyuridine and doublecortin specific markers in the contused brain injury that oc...

  17. Bipolar electrode selection for a motor imagery based brain computer interface

    Science.gov (United States)

    Lou, Bin; Hong, Bo; Gao, Xiaorong; Gao, Shangkai

    2008-09-01

    A motor imagery based brain-computer interface (BCI) provides a non-muscular communication channel that enables people with paralysis to control external devices using their motor imagination. Reducing the number of electrodes is critical to improving the portability and practicability of the BCI system. A novel method is proposed to reduce the number of electrodes to a total of four by finding the optimal positions of two bipolar electrodes. Independent component analysis (ICA) is applied to find the source components of mu and alpha rhythms, and optimal electrodes are chosen by comparing the projection weights of sources on each channel. The results of eight subjects demonstrate the better classification performance of the optimal layout compared with traditional layouts, and the stability of this optimal layout over a one week interval was further verified.

  18. OPTIMAL REPRESENTATION OF MER SIGNALS APPLIED TO THE IDENTIFICATION OF BRAIN STRUCTURES DURING DEEP BRAIN STIMULATION

    Directory of Open Access Journals (Sweden)

    Hernán Darío Vargas Cardona

    2015-07-01

    Full Text Available Identification of brain signals from microelectrode recordings (MER is a key procedure during deep brain stimulation (DBS applied in Parkinson’s disease patients. The main purpose of this research work is to identify with high accuracy a brain structure called subthalamic nucleus (STN, since it is the target structure where the DBS achieves the best therapeutic results. To do this, we present an approach for optimal representation of MER signals through method of frames. We obtain coefficients that minimize the Euclidean norm of order two. From optimal coefficients, we extract some features from signals combining the wavelet packet and cosine dictionaries. For a comparison frame with the state of the art, we also process the signals using the discrete wavelet transform (DWT with several mother functions. We validate the proposed methodology in a real data base. We employ simple supervised machine learning algorithms, as the K-Nearest Neighbors classifier (K-NN, a linear Bayesian classifier (LDC and a quadratic Bayesian classifier (QDC. Classification results obtained with the proposed method improves significantly the performance of the DWT. We achieve a positive identification of the STN superior to 97,6%. Identification outcomes achieved by the MOF are highly accurate, as we can potentially get a false positive rate of less than 2% during the DBS.

  19. Comparison of stimulation selectivity in monopolar and bipolar configuration using the Transversal Intrafascicular Multichannel Electrode (TIME) - Preliminary results

    OpenAIRE

    Maciejasz, Paweł; Badia, Jordi; Boretius, Tim; Harreby, Kristian Rauhe; Jensen, Winnie; Stieglitz, Thomas; Navarro, Xavier; Guiraud, David

    2013-01-01

    The Transversal Intrafascicular Multichannel Electrode (TIME) is intended to be implanted transversally in the nerve and address several fascicles or subgroups of nerve fibres with one device. It has been already shown that TIME allows to achieve high selectivity of stimulation when using monopolar configuration, i.e. when current is delivered through one of the sites of the TIME against small needle electrode placed in the proximity of the nerve. Results of the current study suggest that usi...

  20. Validating computationally predicted TMS stimulation areas using direct electrical stimulation in patients with brain tumors near precentral regions

    Directory of Open Access Journals (Sweden)

    Alexander Opitz

    2014-01-01

    Full Text Available The spatial extent of transcranial magnetic stimulation (TMS is of paramount interest for all studies employing this method. It is generally assumed that the induced electric field is the crucial parameter to determine which cortical regions are excited. While it is difficult to directly measure the electric field, one usually relies on computational models to estimate the electric field distribution. Direct electrical stimulation (DES is a local brain stimulation method generally considered the gold standard to map structure–function relationships in the brain. Its application is typically limited to patients undergoing brain surgery. In this study we compare the computationally predicted stimulation area in TMS with the DES area in six patients with tumors near precentral regions. We combine a motor evoked potential (MEP mapping experiment for both TMS and DES with realistic individual finite element method (FEM simulations of the electric field distribution during TMS and DES. On average, stimulation areas in TMS and DES show an overlap of up to 80%, thus validating our computational physiology approach to estimate TMS excitation volumes. Our results can help in understanding the spatial spread of TMS effects and in optimizing stimulation protocols to more specifically target certain cortical regions based on computational modeling.

  1. [Non-invasive brain stimulation in neurology : Transcranial direct current stimulation to enhance cognitive functioning].

    Science.gov (United States)

    Antonenko, D; Flöel, A

    2016-08-01

    Transcranial direct current stimulation (tDCS) has been successfully used in neuroscientific research to modulate cognitive functions. Recent studies suggested that improvement of behavioral performance is associated with tDCS-induced modulation of neuronal activity and connectivity. Thus, tDCS may also represent a promising tool for reconstitution of cognitive functions in the context of memory decline related to Alzheimer's disease or aphasia following stroke; however, evidence from randomized sham-controlled clinical trials is still scarce. Initial results of tDCS-induced behavioral improvement in patients with Alzheimer's dementia and its precursors indicated that an intense memory training combined with tDCS may be effective. Early interventions in the stage of mild cognitive impairment could be crucial but further evidence is needed to substantiate this. In patients with aphasia following stroke tDCS was applied to the left and right hemispheres, with varying results depending on the severity of the symptoms and polarity of the stimulation. Patients with mild aphasia can benefit from tDCS of the language dominant hemisphere while in patients with severe aphasia tDCS of right hemispheric homologous brain language areas may be particularly relevant. Moreover, recent studies suggested that an intervention in the subacute phase of aphasia could be most promising. In summary, tDCS could provide the exciting possibility to reconstitute cognitive functions in patients with neurological disorders. Future studies have to elucidate whether tDCS can be used in the clinical routine to prevent further cognitive decline in neurodegenerative diseases and whether beneficial effects from experimental studies translate into long-term improvement in activities of daily life. PMID:27167887

  2. Selectivity of direct and network-mediated stimulation of the retinal ganglion cells with epi-, sub- and intraretinal electrodes

    Science.gov (United States)

    Boinagrov, David; Pangratz-Fuehrer, Susanne; Goetz, Georges; Palanker, Daniel

    2014-04-01

    Objective. Intra-retinal placement of stimulating electrodes can provide close and stable proximity to target neurons. We assessed improvement in stimulation thresholds and selectivity of the direct and network-mediated retinal stimulation with intraretinal electrodes, compared to epiretinal and subretinal placements. Approach. Stimulation thresholds of the retinal ganglion cells (RGCs) in wild-type rat retina were measured using the patch-clamp technique. Direct and network-mediated responses were discriminated using various synaptic blockers. Main results. Three types of RGC responses were identified: short latency (SL, τ 40 ms) originating in photoreceptors. Cathodic epiretinal stimulation exhibited the lowest threshold for direct RGC response and the highest direct selectivity (network/direct thresholds ratio), exceeding a factor of 3 with pulse durations below 0.5 ms. For network-mediated stimulation, the lowest threshold was obtained with anodic pulses in OPL position, and its network selectivity (direct/network thresholds ratio) increased with pulse duration, exceeding a factor of 4 at 10 ms. Latency of all three types of responses decreased with increasing strength of the stimulus. Significance. These results define the optimal range of pulse durations, pulse polarities and electrode placement for the retinal prostheses aiming at direct or network-mediated stimulation of RGCs.

  3. A Novel Approach to Assess Motor Outcome of Deep Brain Stimulation Effects in the Hemiparkinsonian Rat: Staircase and Cylinder Test.

    Science.gov (United States)

    Rattka, Marta; Fluri, Felix; Krstić, Miloš; Asan, Esther; Volkmann, Jens

    2016-01-01

    Deep brain stimulation of the subthalamic nucleus is an effective treatment option for Parkinson's disease. In our lab we established a protocol to screen different neurostimulation patterns in hemiparkinsonian (unilateral lesioned) rats. It consists of creating a unilateral Parkinson's lesion by injecting 6-hydroxydopamine (6-OHDA) into the right medial forebrain bundle, implanting chronic stimulation electrodes into the subthalamic nucleus and evaluating motor outcomes at the end of 24 hr periods of cable-bound external neurostimulation. The stimulation was conducted with constant current stimulation. The amplitude was set 20% below the individual threshold for side effects. The motor outcome evaluation was done by the assessment of spontaneous paw use in the cylinder test according to Shallert and by the assessment of skilled reaching in the staircase test according to Montoya. This protocol describes in detail the training in the staircase box, the cylinder test, as well as the use of both in hemiparkinsonian rats. The use of both tests is necessary, because the staircase test seems to be more sensitive for fine motor skill impairment and exhibits greater sensitivity to change during neurostimulation. The combination of the unilateral Parkinson model and the two behavioral tests allows the assessment of different stimulation parameters in a standardized way. PMID:27284739

  4. Impact of metal artefacts due to EEG electrodes in brain PET/CT imaging

    International Nuclear Information System (INIS)

    The goal of this study is to investigate the impact of electroencephalogram (EEG) electrodes on the visual quality and quantification of 18F-FDG PET images in neurological PET/CT examinations. For this purpose, the scans of 20 epilepsy patients with EEG monitoring were used. The CT data were reconstructed with filtered backprojection (FBP) and with a metal artefact reduction (MAR) algorithm. Both data sets were used for CT-based attenuation correction (AC) of the PET data. Also, a calculated AC (CALC) technique was considered. A volume of interest (VOI)-based analysis and a voxel-based quantitative analysis were performed to compare the different AC methods. Images were also evaluated visually by two observers. It was shown with simulations and phantom measurements that from the considered AC methods, the MAR-AC can be used as the reference in this setting. The visual assessment of PET images showed local hot spots outside the brain corresponding to the locations of the electrodes when using FBP-AC. In the brain, no abnormalities were observed. The quantitative analysis showed a very good correlation between PET-FBP-AC and PET-MAR-AC, with a statistically significant positive bias in the PET-FBP-AC images of about 5-7% in most brain voxels. There was also good correlation between PET-CALC-AC and PET-MAR-AC, but in the PET-CALC-AC images, regions with both a significant positive and negative bias were observed. EEG electrodes give rise to local hot spots outside the brain and a positive quantification bias in the brain. However, when diagnosis is made by mere visual assessment, the presence of EEG electrodes does not seem to alter the diagnosis. When quantification is performed, the bias becomes an issue especially when comparing brain images with and without EEG monitoring

  5. Is deep brain stimulation a treatment option for anorexia nervosa?

    Science.gov (United States)

    Oudijn, Marloes S; Storosum, Jitschak G; Nelis, Elise; Denys, Damiaan

    2013-01-01

    Anorexia nervosa (AN) is a severe psychiatric disorder with high rates of morbidity, comorbidity and mortality, which in a subset of patients (21%) takes on a chronic course. Since an evidence based treatment for AN is scarce, it is crucial to investigate new treatment options, preferably focused on influencing the underlying neurobiological mechanisms of AN. The objective of the present paper was to review the evidence for possible neurobiological correlates of AN, and to hypothesize about potential targets for Deep brain stimulation (DBS) as a treatment for chronic, therapy-refractory AN. One avenue for exploring new treatment options based on the neurobiological correlates of AN, is the search for symptomatologic and neurobiologic parallels between AN and other compulsivity- or reward-related disorders. As in other compulsive disorders, the fronto-striatal circuitry, in particular the insula, the ventral striatum (VS) and the prefrontal, orbitofrontal, temporal, parietal and anterior cingulate cortices, are likely to be implicated in the neuropathogenesis of AN. In this paper we will review the few available cases in which DBS has been performed in patients with AN (either as primary diagnosis or as comorbid condition). Given the overlap in symptomatology and neurocircuitry between reward-related disorders such as obsessive compulsive disorder (OCD) and AN, and the established efficacy of accumbal DBS in OCD, we hypothesize that DBS of the nucleus accumbens (NAc) and other areas associated with reward, e.g. the anterior cingulated cortex (ACC), might be an effective treatment for patients with chronic, treatment refractory AN, providing not only weight restoration, but also significant and sustained improvement in AN core symptoms and associated comorbidities and complications. Possible targets for DBS in AN are the ACC, the ventral anterior limb of the capsula interna (vALIC) and the VS. We suggest conducting larger efficacy studies that also explore the

  6. Delayed awakening in dystonia patients undergoing deep brain stimulation surgery.

    Science.gov (United States)

    Trombetta, Carlos; Deogaonkar, Anupa; Deogaonkar, Milind; Ebrahim, Zeyd; Rezai, Ali; Machado, Andre; Farag, Ehab

    2010-07-01

    We aimed to identify the incidence, duration and causes of delayed emergence from anesthesia in patients with dystonia undergoing surgery for deep brain stimulation (DBS) placement. A retrospective review of patients with dystonia who underwent DBS placement was conducted and the following characteristics were noted: age, gender, comorbid conditions, American Society of Anesthesiologists classification, anesthetic agents used, amount of initial dose, amount of infusion dose, duration of the infusion and the time needed for emergence. Twenty-four patients underwent 33 DBS procedures for dystonia. Propofol was administered to 21 patients, in 29 of the 33 procedures. Dexmedetomidine was administered to three patients, in four procedures. The average propofol loading dose was 0.7mg/kg, and the infusion rate was 80microg/kg per minute (min), for an average duration of 89min. The average time of emergence was 36min. Only 31% of patients emerged from propofol anesthesia during the expected time frame, 69% of patients had some degree of delayed emergence, and 24% had a significant delay in emergence. Delayed emergence was more common in younger patients due to the higher loading doses these patients received. This study shows a 69% incidence of delayed emergence in dystonia patients undergoing DBS surgery. It also suggests an association between delayed emergence and younger patients who receive higher loading doses. A possible cause of delayed emergence is excessive anesthetic potentiation of the low output pallidal state in dystonia which may depress the pallido-thalamo-cortical circuitry. Delayed emergence could also result from depression of the previously affected ventral pallidal inputs to the septo-hippocampal system that mediates general anesthesia and awareness. Complex neurotransmitter disturbances may also be involved. PMID:20466547

  7. Neuroprotective effects of vagus nerve stimulation on traumatic brain injur y

    Institute of Scientific and Technical Information of China (English)

    Long Zhou; Jinhuang Lin; Junming Lin; Guoju Kui; Jianhua Zhang; Yigang Yu

    2014-01-01

    Previous studies have shown that vagus nerve stimulation can improve the prognosis of trau-matic brain injury. The aim of this study was to elucidate the mechanism of the neuroprotective effects of vagus nerve stimulation in rabbits with brain explosive injury. Rabbits with brain ex-plosive injury received continuous stimulation (10 V, 5 Hz, 5 ms, 20 minutes) of the right cervical vagus nerve. Tumor necrosis factor-α, interleukin-1βand interleukin-10 concentrations were detected in serum and brain tissues, and water content in brain tissues was measured. Results showed that vagus nerve stimulation could reduce the degree of brain edema, decrease tumor necrosis factor-αand interleukin-1βconcentrations, and increase interleukin-10 concentration after brain explosive injury in rabbits. These data suggest that vagus nerve stimulation may exert neuroprotective effects against explosive injury via regulating the expression of tumor necrosis factor-α, interleukin-1βand interleukin-10 in the serum and brain tissue.

  8. Conditioning of brain stimulation-induced presleep behavior.

    Science.gov (United States)

    Wyrwicka, W; Chase, M H

    1994-11-01

    Experiments were conducted on three chronic unanesthetized, undrugged cats. Electrical stimulation of the basal forebrain area (BFA) resulted in presleep behavior (i.e., the cats would sit or lie down, and EEG spindles would arise). After several sessions (conducted twice a week), two of these cats began to exhibit presleep behavior almost immediately after entering the experimental compartment, even before the application of BFA stimulation. The third cat often ate some food (which was always present in the compartment) before showing presleep behavior. When stimulation was withheld during an extinction procedure, the cats still exhibited presleep behavior in the absence of stimulation during several sessions. We conclude that repeated BFA stimulation led to conditioning of the stimulation effects, that is, the presleep behavior that was evoked by the environmental situation alone, without BFA stimulation or any other intermittent stimulus. PMID:7824587

  9. Active stimulation site of nucleus accumbens deep brain stimulation in obsessive-compulsive disorder is localized in the ventral internal capsule.

    Science.gov (United States)

    van den Munckhof, Pepijn; Bosch, D Andries; Mantione, Mariska H M; Figee, Martijn; Denys, Damiaan A J P; Schuurman, P Richard

    2013-01-01

    Obsessive-compulsive disorder (OCD) is a chronic psychiatric disorder characterized by persistent thoughts and repetitive ritualistic behaviours. Despite optimal cognitive-behavioral and pharmacological therapy, approximately 10 % of patients remain treatment-resistant. Deep brain stimulation (DBS) is being investigated as experimental therapy for treatment-refractory OCD. In the current study, we determined the relationship between anatomical location of active electrode contacts and clinical outcome in 16 OCD patients undergoing bilateral nucleus accumbens (NAc) DBS. We found that most patients actually do not receive active stimulation in the NAc but in the more laterally, anteriorly and dorsally located ventral part of the anterior limb of the internal capsule, ventral ALIC (vALIC). Our nine patients receiving bilateral vALIC DBS improved on average 73 % on their Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores, whereas the six patients with their centers of stimulation located otherwise improved on average only 42 %. We therefore propose bilateral vALIC as a promising new DBS target for patients with treatment-refractory OCD. Future studies employing a direct vALIC targeting approach in larger patient numbers are needed to test whether this proposal holds true. PMID:23652657

  10. Deep brain stimulation as a tool for improving cognitive functioning in Alzheimer’s dementia: a systematic review

    Directory of Open Access Journals (Sweden)

    KatjaHardenacke

    2013-12-01

    Full Text Available Deep brain stimulation (DBS is an established, in selected cases therapeutically effective, non-lesional treatment method delivering current rectangular pulses into dysfunctional brain structures via chronically implanted stimulation electrodes. DBS is a recognized method applied in movement disorders and is increasingly evaluated as a possible therapeutic option for psychiatric diseases such as refractory obsessive-compulsive disorders, Gilles de la Tourette syndrome, major depression and substance-related addiction. Latest research indicates that DBS may be a method for improving cognitive functions in Alzheimer’s dementia (AD. Translational data in healthy and AD animals appear to support this notion. Nevertheless, many aspects remain unclear, particularly with regard to the optimal target structure. The objective of this review is to present a systematic overview regarding published research on DBS and cognitive functioning in animal and human studies as well as to provide a systematic overview of the feasibility and efficacy of the treatment. We describe three studies investigating the effects of DBS in patients with dementia, using either the fornix or the nucleus basalis of Meynert as a target. In total, we identified 25 animal studies with 10 brain structures being targeted: fornix, nucleus basalis of Meynert, anterior caudate nucleus, dorsal striatum, anterior thalamic nucleus, midline thalamic nuclei, central thalamic nuclei, lateral hypothalamus, hippocampus (entorhinal cortex, perforant path and amygdala. Considering the wide and diverse spectrum of targets, we add to this review a supposition about possible underlying mechanisms of operation and recommendations for further research.

  11. Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology

    DEFF Research Database (Denmark)

    Bergmann, Til Ole; Karabanov, Anke; Hartwigsen, Gesa;

    2016-01-01

    and 'offline' NTBS effects outlasting plasticity-inducing NTBS protocols can be assessed. Finally, both strategies can be combined to close the loop between measuring and modulating brain activity by means of closed-loop brain state-dependent NTBS. In this paper, we will provide a conceptual framework......Non-invasive transcranial brain stimulation (NTBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial current stimulation (TCS) are important tools in human systems and cognitive neuroscience because they are able to reveal the relevance of certain brain structures or...... neuronal activity patterns for a given brain function. It is nowadays feasible to combine NTBS, either consecutively or concurrently, with a variety of neuroimaging and electrophysiological techniques. Here we discuss what kind of information can be gained from combined approaches, which often are...

  12. Deep brain stimulation for the obsessive-compulsive and Tourette-like symptoms of Kleefstra syndrome.

    Science.gov (United States)

    Segar, David J; Chodakiewitz, Yosef G; Torabi, Radmehr; Cosgrove, G Rees

    2015-06-01

    Deep brain stimulation (DBS) has been reported to have beneficial effects in severe, treatment-refractory cases of obsessive-compulsive disorder (OCD) and Tourette syndrome (TS). In this report, the authors present the first case in which DBS was used to treat the neuropsychiatric symptoms of Kleefstra syndrome, a rare genetic disorder characterized by childhood hypotonia, intellectual disability, distinctive facial features, and myriad psychiatric and behavioral disturbances. A 24-year-old female patient with childhood hypotonia, developmental delay, and diagnoses of autism spectrum disorder, OCD, and TS refractory to medical management underwent the placement of bilateral ventral capsule/ventral striatum (VC/VS) DBS leads, with clinical improvement. Medical providers and family observed gradual and progressive improvement in the patient's compulsive behaviors, coprolalia, speech, and social interaction. Symptoms recurred when both DBS electrodes failed because of lead fracture and dislodgement, although the clinical benefits were restored by lead replacement. The symptomatic and functional improvements observed in this case of VC/VS DBS for Kleefstra syndrome suggest a novel indication for DBS worthy of further investigation. PMID:26030700

  13. The mechanisms of action of deep brain stimulation and ideas for the future development.

    Science.gov (United States)

    Udupa, Kaviraja; Chen, Robert

    2015-10-01

    Deep brain stimulation (DBS) has been used as a treatment of movement disorders such as Parkinson's disease, dystonia, and essential tremor for over twenty years, and is a promising treatment for depression and epilepsy. However, the exact mechanisms of action of DBS are still uncertain, although different theories have emerged. This review summarizes the current understanding in this field. Different modalities used to investigate DBS such as electrophysiological, imaging and biochemical studies have revealed different mechanisms of DBS. The mechanisms may also be different depending on the structure targeted, the disease condition or the animal model employed. DBS may inhibit the target neuronal networks but activate the efferent axons. It may suppress pathological rhythms or impose new rhythms associated with beneficial effects, and involves neuronal networks with widespread connections. Different neurotransmitter systems such as dopamine and GABA upregulation are involved in the effects of DBS. There are also technical advances to prolong the battery life and specific targeting based on new electrode designs with multiple contacts which have the ability to steer the current toward a specific direction. There is ongoing work in closed loop or adaptive DBS using neural oscillations to provide the feedback signals. These oscillations need to be better characterized in a wide variety of clinical settings in future studies. Individualization of DBS parameters based on neural oscillations may optimize the clinical benefits of DBS. PMID:26296674

  14. Electrical Stimulation of the Suprahyoid Muscles in Brain-injured Patients with Dysphagia: A Pilot Study

    OpenAIRE

    Beom, Jaewon; Kim, Sang Jun; Han, Tai Ryoon

    2011-01-01

    Objective To investigate the therapeutic effects of repetitive electrical stimulation of the suprahyoid muscles in brain-injured patients with dysphagia. Method Twenty-eight brain-injured patients who showed reduced laryngeal elevation and supraglottic penetration or subglottic aspiration during a videofluoroscopic swallowing study (VFSS) were selected. The patients received either conventional dysphagia management (CDM) or CDM with repetitive electrical stimulation of the suprahyoid muscles ...

  15. Comparison of dry and gel based electrodes for P300 brain-computer interfaces

    Directory of Open Access Journals (Sweden)

    Christoph eGuger

    2012-05-01

    Full Text Available Most brain-computer interfaces (BCI rely on one of three types of signals in the electroencephalogram (EEG: P300s, steady-state visually evoked potentials (SSVEP, and event-related desynchronization (ERD. EEG is typically recorded non-invasively with electrodes mounted on the human scalp using conductive electrode gel for optimal impedance and data quality. The use of electrode gel entails serious problems that are especially pronounced in real-world settings when experts are not available. Some recent work has introduced dry electrode systems that do not require gel, but often introduce new problems such as comfort and signal quality. The principal goal of this study was to assess a new dry electrode BCI system in a very common task: spelling with a P300 BCI. A total of 23 subjects used a P300 BCI to spell the word LUCAS while receiving realtime, closed-loop feedback. The dry system yielded classification accuracies that were similar to those obtained with gel systems. All subjects completed a questionnaire after data recording, and all subjects stated that the dry system was not uncomfortable. This is the first field validation of a dry electrode P300 BCI system, and paves the way for new research and development with EEG recording systems that are much more practical and convenient in field settings than conventional systems.

  16. [Interest of EEG recording during direct electrical stimulation for brain mapping function in surgery].

    Science.gov (United States)

    Trebuchon, A; Guye, M; Tcherniack, V; Tramoni, E; Bruder, N; Metellus, P

    2012-06-01

    Brain tumor surgery is at risk when lesions are located in eloquent areas. The interindividual anatomo-functional variability of the central nervous system implies that brain surgery within eloquent regions may induce neurological sequelae. Brain mapping using intraoperative direct electrical stimulation in awake patients has been for long validated as the standard for functional brain mapping. Direct electrical stimulation inducing a local transient electrical and functional disorganization is considered positive if the task performed by the patient is disturbed. The brain area stimulated is then considered as essential for the function tested. However, the exactitude of the information provided by this technique is cautious because the actual impact of cortical direct electrical stimulation is not known. Indeed, the possibility of false negative (insufficient intensity of the stimulation due to the heterogeneity of excitability threshold of different cortical areas) or false positive (current spread, interregional signal propagation responsible for remote effects, which make difficult the interpretation of positive or negative behavioural effects) constitute a limitation of this technique. To improve the sensitivity and specificity of this technique, we used an electrocorticographic recording system allowing a real time visualization of the local. We provide here evidence that direct cortical stimulation combined with electrocorticographic recording could be useful to detect remote after discharge and to adjust stimulation parameters. In addition this technique offers new perspective to better assess connectivity of cerebral networks. PMID:22683402

  17. Pulse electrical arc stimulator based on single-electrode for active exercise in tail-suspension rat

    Institute of Scientific and Technical Information of China (English)

    孙联文; 谢添; 樊瑜波; 张晓薇; 孙瑶; 杨肖

    2008-01-01

    To make rat do active exercise to counteract bone loss in the rat tail-suspension model, a pulse electrical stimulator based on single-electrode with a low-current and a high-voltage was designed. The stimulator was controlled by SCM (single chip micyoco) that could accurately control the stimulation duration and the interval between stimulations, and cease the operation after the recorded number of stimulation had reached the value set by the program. With the help of posture estimation part, the device would operate intelligently by determining whether to stimulate or not, depending on the posture of rat’s limb. Software was developed to make operator control the stimulator using computer, save the experiment data and print the report. In practical experiment, the voltaic arc is generated by the stimulator, and impacted on the rat’s thenar. This induced pain to the rat and the rat would actively contract its hindlimb to evade the pain, so active exercise was carried out. The tail-suspension rats were trained twice every day for 14 d. At the 0 and 14th day, bone mineral density of rat femurs was determined by dual energy X-ray absorptiometry (DXA). The results show that the active exercise stimulated by the pulse electrical arc stimulator can attenuate weightlessness-induced bone loss, and this device is a convenient steady performance electrical stimulator that can surely induce rat’s hindlimb to do active exercise.

  18. Respiratory responses to stimulation of abdominal and upper-thorax intercostal muscles using multiple Permaloc® electrodes

    Directory of Open Access Journals (Sweden)

    James S. Walter, PhD

    2015-04-01

    Full Text Available Stimulation of abdominal and upper-thoracic muscles was studied with the long-term goal of improved respiratory care for spinal cord injury (SCI patients. A 12-channel stimulator and multiple surface and implanted Permaloc electrodes were evaluated in five anesthetized canines. Abdominal stimulation with 100 mA using four bilateral sets of surface electrodes placed on the midaxillary line at the 7th through 13th intercostal spaces and with a closed airway at a large lung volume produced an expiratory tracheal pressure of 109 +/– 29 cm H2O (n = 2, mean +/– standard error of the mean. Similar high pressures were induced with implanted electrodes at the same locations. Upper-thoracic stimulation with 40 mA and four sets of implanted electrodes ventral to the axilla induced inspiratory pressures of −12 +/– 2 cm H2O (n = 5. Combined extradiaphragmatic pacing with an open airway produced a tidal volume of 440 +/– 45 mL (n = 4. The robust respiratory volumes and pressures suggest applications in SCI respiratory care.

  19. Psychiatric and Cognitive Effects of Deep Brain Stimulation for Parkinson's Disease.

    Science.gov (United States)

    Nassery, Adam; Palmese, Christina A; Sarva, Harini; Groves, Mark; Miravite, Joan; Kopell, Brian Harris

    2016-10-01

    Deep brain stimulation (DBS) is effective for Parkinson's disease (PD), dystonia, and essential tremor (ET). While motor benefits are well documented, cognitive and psychiatric side effects from the subthalamic nucleus (STN) and globus pallidus interna (GPi) DBS for PD are increasingly recognized. Underlying disease, medications, microlesions, and post-surgical stimulation likely all contribute to non-motor symptoms (NMS). PMID:27539167

  20. The Effect of Deep Brain Stimulation on the Speech Motor System

    Science.gov (United States)

    Mücke, Doris; Becker, Johannes; Barbe, Michael T.; Meister, Ingo; Liebhart, Lena; Roettger, Timo B.; Dembek, Till; Timmermann, Lars; Grice, Martine

    2014-01-01

    Purpose: Chronic deep brain stimulation of the nucleus ventralis intermedius is an effective treatment for individuals with medication-resistant essential tremor. However, these individuals report that stimulation has a deleterious effect on their speech. The present study investigates one important factor leading to these effects: the…

  1. Rebound of affective symptoms following acute cessation of deep brain stimulation in obsessive-compulsive disorder

    NARCIS (Netherlands)

    Ooms, Pieter; Blankers, Matthijs; Figee, Martijn; Mantione, Mariska; van den Munckhof, Pepijn; Schuurman, P Richard; Denys, D.

    2014-01-01

    BACKGROUND: Deep brain stimulation (DBS) is regarded as an effective way to treat refractory obsessive-compulsive disorder (OCD). Little is known about the effects of DBS cessation following a longer period of stimulation. OBJECTIVE: To determine the relapse and rebound effects of psychiatric sympto

  2. No impact of deep brain stimulation on fear–potentiated startle in obsessive-compulsive disorder

    NARCIS (Netherlands)

    Baas, Johanna M P; Klumpers, Floris; Mantione, Mariska H.; Figee, Martijn; Vulink, Nienke C.; Richard Schuurman, P.; Mazaheri, Ali; Denys, Damiaan

    2014-01-01

    Deep brain stimulation (DBS) of the ventral internal capsule is effective in treating therapy refractory obsessive-compulsive disorder (OCD). Given the close proximity of the stimulation site to the stria terminalis (BNST), we hypothesized that the striking decrease in anxiety symptoms following DBS

  3. No impact of deep brain stimulation on fear-potentiated startle in obsessive-compulsive disorder

    NARCIS (Netherlands)

    Baas, Johanna M P; Klumpers, Floris; Mantione, Mariska H; Figee, Martijn; Vulink, Nienke C; Schuurman, P Richard; Mazaheri, Ali; Denys, D.

    2014-01-01

    Deep brain stimulation (DBS) of the ventral internal capsule is effective in treating therapy refractory obsessive-compulsive disorder (OCD). Given the close proximity of the stimulation site to the stria terminalis (BNST), we hypothesized that the striking decrease in anxiety symptoms following DBS

  4. Non-invasive brain stimulation in neglect rehabilitation: An update.

    Directory of Open Access Journals (Sweden)

    René Martin Müri

    2013-06-01

    The studies are heterogeneous concerning their methodology, outcome measures, and stimulation parameters making firm comparisons and conclusions difficult. Overall, there are however promising results for theta burst stimulation, suggesting that TMS is a powerful add-on therapy in the rehabilitation of neglect patients.

  5. The challenge of crafting policy for do-it-yourself brain stimulation

    OpenAIRE

    Fitz, Nicholas S; Reiner, Peter B

    2013-01-01

    Transcranial direct current stimulation (tDCS), a simple means of brain stimulation, possesses a trifecta of appealing features: it is relatively safe, relatively inexpensive and relatively effective. It is also relatively easy to obtain a device and the do-it-yourself (DIY) community has become galvanised by reports that tDCS can be used as an all-purpose cognitive enhancer. We provide practical recommendations designed to guide balanced discourse, propagate norms of safe use and stimulate d...

  6. Targeting neural endophenotypes of eating disorders with non-invasive brain stimulation

    OpenAIRE

    Katharine A Dunlop; Blake eWoodside; Jonathan eDownar

    2016-01-01

    The term eating disorders (ED) encompasses a wide variety of disordered eating and compensatory behaviors, and so the term is associated with considerable clinical and phenotypic heterogeneity. This heterogeneity makes optimizing treatment techniques difficult. One class of treatments is non-invasive brain stimulation (NIBS). NIBS, including repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are accessible forms of neuromodulation that alter...

  7. Targeting Neural Endophenotypes of Eating Disorders with Non-invasive Brain Stimulation

    OpenAIRE

    Katharine A Dunlop; Woodside, Blake; Downar, Jonathan

    2016-01-01

    The term “eating disorders” (ED) encompasses a wide variety of disordered eating and compensatory behaviors, and so the term is associated with considerable clinical and phenotypic heterogeneity. This heterogeneity makes optimizing treatment techniques difficult. One class of treatments is non-invasive brain stimulation (NIBS). NIBS, including repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), are accessible forms of neuromodulation that al...

  8. Restoring Cognitive Functions Using Non-Invasive Brain Stimulation Techniques in Patients with Cerebellar Disorders

    OpenAIRE

    RChrisMiall

    2014-01-01

    Numerous studies have highlighted the possibility of modulating the excitability of cerebro–cerebellar circuits bi-directionally using transcranial electrical brain stimulation, in a manner akin to that observed using magnetic stimulation protocols. It has been proposed that cerebellar stimulation activates Purkinje cells in the cerebellar cortex, leading to inhibition of the dentate nucleus, which exerts a tonic facilitatory drive onto motor and cognitive regions of cortex through a synaptic...

  9. An external portable device for adaptive deep brain stimulation (aDBS) clinical research in advanced Parkinson's Disease.

    Science.gov (United States)

    Arlotti, Mattia; Rossi, Lorenzo; Rosa, Manuela; Marceglia, Sara; Priori, Alberto

    2016-05-01

    Compared to conventional deep brain stimulation (DBS) for patients with Parkinson's Disease (PD), the newer approach of adaptive DBS (aDBS), regulating stimulation on the basis of the patient's clinical state, promises to achieve better clinical outcomes, avoid adverse-effects and save time for tuning parameters. A remaining challenge before aDBS comes into practical use is to prove its feasibility and its effectiveness in larger groups of patients and in more ecological conditions. We developed an external portable aDBS system prototype designed for clinical testing in freely-moving PD patients with externalized DBS electrodes. From a single-channel bipolar artifact-free recording, it analyses local field potentials (LFPs), during ongoing DBS for tuning stimulation parameters, independent from the specific feedback algorithm implemented. We validated the aDBS system in vitro, by testing both its sensing and closed-loop stimulation capabilities, and then tested it in vivo, focusing on the sensing capabilities. By applying the aDBS system prototype in a patient with PD, we provided evidence that it can track levodopa and DBS-induced LFP spectral power changes among different patient's clinical states. Our system, intended for testing LFP-based feedback strategies for aDBS, should help understanding how and whether aDBS therapy works in PD and indicating future technical and clinical advances. PMID:27029510

  10. REACHING TO PROPRIOCEPTIVELY DEFINED TARGETS IN PARKINSON’S DISEASE: EFFECTS OF DEEP BRAIN STIMULATION THERAPY

    OpenAIRE

    Lee, D.; HENRIQUES, D. Y.; Snider, J.; Song, D.; POIZNER, H.

    2013-01-01

    Deep brain stimulation of the subthalamic nucleus (STN DBS) provides a unique window into human brain function since it can reversibly alter the functioning of specific brain circuits. Basal ganglia–cortical circuits are thought to be excessively noisy in patients with Parkinson’s disease (PD), based in part on the lack of specificity of proprioceptive signals in basal ganglia–thalamic–cortical circuits in monkey models of the disease. PD patients are known to have deficits in proprioception,...

  11. Brain Topological Correlates of Motor Performance Changes After Repetitive Transcranial Magnetic Stimulation

    OpenAIRE

    Park, Chang-hyun; Chang, Won Hyuk; Yoo, Woo-Kyoung; Shin, Yong-Il; Kim, Sung Tae; Kim, Yun-Hee

    2014-01-01

    Repetitive transcranial magnetic stimulation (rTMS) influences the brain temporally beyond the stimulation period and spatially beyond the stimulation site. Application of rTMS over the primary motor cortex (M1) has been shown to lead to plastic changes in interregional connectivity over the motor system as well as alterations in motor performance. With a sequential combination of rTMS over the M1 and functional magnetic resonance imaging (fMRI), we sought changes in the topology of brain net...

  12. Wada-test, functional magnetic resonance imaging and direct electrical stimulation - brain mapping methods

    International Nuclear Information System (INIS)

    Modern neurosurgery requires accurate preoperative and intraoperative localization of brain pathologies but also of brain functions. The presence of individual variations in healthy subjects and the shift of brain functions in brain diseases provoke the introduction of various methods for brain mapping. The aim of this paper was to analyze the most widespread methods for brain mapping: Wada-test, functional magnetic resonance imaging (fMRI) and intraoperative direct electrical stimulation (DES). This study included 4 patients with preoperative brain mapping using Wada-test and fMRI. Intraoperative mapping with DES during awake craniotomy was performed in one case. The histopathological diagnosis was low-grade glioma in 2 cases, cortical dysplasia (1 patient) and arteriovenous malformation (1 patient). The brain mapping permits total lesion resection in three of four patients. There was no new postoperative deficit despite surgery near or within functional brain areas. Brain plasticity provoking shift of eloquent areas from their usual locations was observed in two cases. The brain mapping methods allow surgery in eloquent brain areas recognized in the past as 'forbidden areas'. Each method has advantages and disadvantages. The precise location of brain functions and pathologies frequently requires combination of different brain mapping methods. (authors)

  13. Deep brain stimulation reveals emotional impact processing in ventromedial prefrontal cortex

    DEFF Research Database (Denmark)

    Gjedde, Albert; Geday, Jacob

    2009-01-01

    We tested the hypothesis that modulation of monoaminergic tone with deep-brain stimulation (DBS) of subthalamic nucleus would reveal a site of reactivity in the ventromedial prefrontal cortex that we previously identified by modulating serotonergic and noradrenergic mechanisms by blocking serotonin......-noradrenaline reuptake sites. We tested the hypothesis in patients with Parkinson's disease in whom we had measured the changes of blood flow everywhere in the brain associated with the deep brain stimulation of the subthalamic nucleus. We determined the emotional reactivity of the patients as the average impact of...... emotive images rated by the patients off the DBS. We then searched for sites in the brain that had significant correlation of the changes of blood flow with the emotional impact rated by the patients. The results indicate a significant link between the emotional impact when patients are not stimulated and...

  14. Brain responses to acupuncture stimulation in the prosthetic hand of an amputee patient.

    Science.gov (United States)

    Lee, In-Seon; Jung, Won-Mo; Lee, Ye-Seul; Wallraven, Christian; Chae, Younbyoung

    2015-10-01

    This report describes the brain responses to acupuncture in an upper limb amputee patient. A 62-year-old male had previously undergone a lower left arm amputation following an electrical accident. Using functional MRI, we investigated brain responses to acupuncture stimulation in the aforementioned amputee under three conditions: (a) intact hand, (b) prosthetic hand (used by the patient), and (c) fake fabric hand. The patient described greater de qi sensation when he received acupuncture stimulation in his prosthetic hand compared to a fake hand, with both stimulations performed in a similar manner. We found enhanced brain activation in the insula and sensorimotor cortex in response to acupuncture stimulation in the amputee's prosthetic hand, while there was only minimal activation in the visual cortex in response to acupuncture stimulation in a fake hand. The enhanced brain responses to acupuncture stimulation of the patient's prosthetic hand might be derived from cortical reorganisation, as he has been using his prosthetic hand for over 40 years. Our findings suggest the possible use of acupuncture stimulation in a prosthetic hand as an enhanced sensory feedback mechanism, which may represent a new treatment approach for phantom limb pain. PMID:26033865

  15. Electrical stimulation of cerebellar fastigial nucleus protects rat brain, in vitro, from staurosporine-induced apoptosis.

    Science.gov (United States)

    Zhou, P; Qian, L; Glickstein, S B; Golanov, E V; Pickel, V M; Reis, D J

    2001-10-01

    Electrical stimulation of the cerebellar fastigial nucleus (FN) elicits a prolonged ( approximately 10 days) and substantial (50-80%) protection against ischemic and excitotoxic injuries. The mechanism(s) of protection are unknown. We investigated whether FN stimulation directly protects brain cells against apoptotic cell death in an in vitro rat brain slice culture model. Rats were electrically stimulated in FN or, as control, the cerebellar dentate nucleus (DN). Coronal slices through the forebrain were explanted, exposed to staurosporine, harvested, and analyzed for caspase-3 activity by a fluorescence assay. FN, but not DN, stimulation significantly reduced staurosporine-induced caspase-3 activity by 39 +/- 7% at 3 h, 31 +/- 3% at 6 h and 26 +/- 4% at 10 h of incubation. Immunocytochemistry revealed FN-specific reductions in activated caspase-3 mainly in glial-like cells throughout the forebrain. FN stimulation also results in a 56.5% reduction in cytochrome c release upon staurosporine incubation. We conclude that neuroprotection elicited from FN stimulation can directly modify the sensitivity of brain cells to apoptotic stimuli and thereby suppress staurosporine induced apoptosis in adult rat brain slices. This model indicates that neuroprotection can be studied in vitro and provides new insight into the potential role of glial cells in ischemic protection of neurons induced by FN stimulation. PMID:11677261

  16. Optogenetic Tools for Confined Stimulation in Deep Brain Structures.

    Science.gov (United States)

    Castonguay, Alexandre; Thomas, Sébastien; Lesage, Frédéric; Casanova, Christian

    2016-01-01

    Optogenetics has emerged in the past decade as a technique to modulate brain activity with cell-type specificity and with high temporal resolution. Among the challenges associated with this technique is the difficulty to target a spatially restricted neuron population. Indeed, light absorption and scattering in biological tissues make it difficult to illuminate a minute volume, especially in the deep brain, without the use of optical fibers to guide light. This work describes the design and the in vivo application of a side-firing optical fiber adequate for delivering light to specific regions within a brain subcortical structure. PMID:26965129

  17. Toward proton MR spectroscopic imaging of stimulated brain function

    International Nuclear Information System (INIS)

    With the objective of complementing local cerebral metabolic studies of PET, and as a prelude to spectroscopic imaging, the authors have performed the first localized proton spectroscopic study of the stimulated human auditory cortex. Water suppressed localized spectroscopy (voxel size 3cm x 3cm x 3cm enclosing the auditory cortex, Te = 272ms, Tr = 3s) was performed on a 1.5T MRI/MRS system and spectra were acquired during stimulation with a 1kHz tone presented at 2Hz. Measurements were conducted for 30-40 min with a temporal resolution of 3.2 min (64 averages per time block). Results included in this paper from six subjects show a lactate peak which increases during stimulation compared to baseline values. These results suggest an increase in anaerobic glycolysis during stimulation and provide unique and valuable information that should complement glucose metabolism and flood flow studies of PET

  18. Changes in local cerebral glucose utilization during rewarding brain stimulation.

    OpenAIRE

    Esposito, R U; Porrino, L J; Seeger, T F; Crane, A M; Everist, H D; Pert, A

    1984-01-01

    The quantitative 2-deoxy[14C]glucose method was used to determine local cerebral glucose utilization in unrestrained rats responding (lever-press) for rewarding electrical stimulation to area A10 (ventral tegmental area) and in similarly implanted inactive controls. Self-stimulation was associated with significant increases in metabolic activity, highly circumscribed in the ventral tegmental area, that continued rostrally within a rather compact zone of activity through the medial forebrain b...

  19. Exploring miniaturized EEG electrodes for brain-computer interfaces. An EEG you do not see?

    Science.gov (United States)

    Bleichner, Martin G; Lundbeck, Micha; Selisky, Matthias; Minow, Falk; Jäger, Manuela; Emkes, Reiner; Debener, Stefan; De Vos, Maarten

    2015-04-01

    Electroencephalography (EEG) allows the study of the brain-behavior relationship in humans. Most of what we have learned with EEG was through observing the brain-behavior relationship under well-controlled laboratory conditions. However, by reducing "normal" behavior to a minimum the ecological validity of the results can be limited. Recent developments toward mobile EEG solutions allow to study the brain-behavior relationship outside the laboratory in more natural situations. Besides mobility and robustness with respect to motion, mobile EEG systems should also interfere as little as possible with the participant's behavior. For example, natural interaction with other people could be hindered when it is obvious that a participant wears an EEG cap. This study evaluates the signal quality obtained with an unobtrusive solution for EEG monitoring through the integration of miniaturized EEG ton-electrodes into both a discreet baseball cap and an individualized ear piece. We show that such mini electrodes located at scalp and ear locations can reliably record event related potentials in a P300 brain-computer-interface application. PMID:25847919

  20. Neural plasticity in human brain connectivity: the effects of long term deep brain stimulation of the subthalamic nucleus in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Tim J van Hartevelt

    Full Text Available BACKGROUND: Positive clinical outcomes are now well established for deep brain stimulation, but little is known about the effects of long-term deep brain stimulation on brain structural and functional connectivity. Here, we used the rare opportunity to acquire pre- and postoperative diffusion tensor imaging in a patient undergoing deep brain stimulation in bilateral subthalamic nuclei for Parkinson's Disease. This allowed us to analyse the differences in structural connectivity before and after deep brain stimulation. Further, a computational model of spontaneous brain activity was used to estimate the changes in functional connectivity arising from the specific changes in structural connectivity. RESULTS: We found significant localised structural changes as a result of long-term deep brain stimulation. These changes were found in sensory-motor, prefrontal/limbic, and olfactory brain regions which are known to be affected in Parkinson's Disease. The nature of these changes was an increase of nodal efficiency in most areas and a decrease of nodal efficiency in the precentral sensory-motor area. Importantly, the computational model clearly shows the impact of deep brain stimulation-induced structural alterations on functional brain changes, which is to shift the neural dynamics back towards a healthy regime. The results demonstrate that deep brain stimulation in Parkinson's Disease leads to a topological reorganisation towards healthy bifurcation of the functional networks measured in controls, which suggests a potential neural mechanism for the alleviation of symptoms. CONCLUSIONS: The findings suggest that long-term deep brain stimulation has not only restorative effects on the structural connectivity, but also affects the functional connectivity at a global level. Overall, our results support causal changes in human neural plasticity after long-term deep brain stimulation and may help to identify the underlying mechanisms of deep brain

  1. Deep Brain Stimulation Frequency—A Divining Rod for New and Novel Concepts of Nervous System Function and Therapy

    Directory of Open Access Journals (Sweden)

    Erwin B. Montgomery

    2016-08-01

    Full Text Available The efficacy of Deep Brain Stimulation (DBS for an expanding array of neurological and psychiatric disorders demonstrates directly that DBS affects the basic electroneurophysiological mechanisms of the brain. The increasing array of active electrode configurations, stimulation currents, pulse widths, frequencies, and pulse patterns provides valuable tools to probe electroneurophysiological mechanisms. The extension of basic electroneurophysiological and anatomical concepts using sophisticated computational modeling and simulation has provided relatively straightforward explanations of all the DBS parameters except frequency. This article summarizes current thought about frequency and relevant observations. Current methodological and conceptual errors are critically examined in the hope that future work will not replicate these errors. One possible alternative theory is presented to provide a contrast to many current theories. DBS, conceptually, is a noisy discrete oscillator interacting with the basal ganglia–thalamic–cortical system of multiple re-entrant, discrete oscillators. Implications for positive and negative resonance, stochastic resonance and coherence, noisy synchronization, and holographic memory (related to movement generation are presented. The time course of DBS neuronal responses demonstrates evolution of the DBS response consistent with the dynamics of re-entrant mechanisms. Finally, computational modeling demonstrates identical dynamics as seen by neuronal activities recorded from human and nonhuman primates, illustrating the differences of discrete from continuous harmonic oscillators and the power of conceptualizing the nervous system as composed on interacting discrete nonlinear oscillators.

  2. Malignant neuroleptic syndrome following deep brain stimulation surgery: a case report

    Directory of Open Access Journals (Sweden)

    Stavrinou Lampis C

    2011-06-01

    Full Text Available Abstract Background The neuroleptic malignant syndrome is an uncommon but dangerous complication characterized by hyperthermia, autonomic dysfunction, altered mental state, hemodynamic dysregulation, elevated serum creatine kinase, and rigor. It is most often caused by an adverse reaction to anti-psychotic drugs or abrupt discontinuation of neuroleptic or anti-parkinsonian agents. To the best of our knowledge, it has never been reported following the common practice of discontinuation of anti-parkinsonian drugs during the pre-operative preparation for deep brain stimulation surgery for Parkinson's disease. Case presentation We present the first case of neuroleptic malignant syndrome associated with discontinuation of anti-parkinsonian medication prior to deep brain stimulation surgery in a 54-year-old Caucasian man. Conclusion The characteristic neuroleptic malignant syndrome symptoms can be attributed to other, more common causes associated with deep brain stimulation treatment for Parkinson's disease, thus requiring a high index of clinical suspicion to timely establish the correct diagnosis. As more centers become eligible to perform deep brain stimulation, neurologists and neurosurgeons alike should be aware of this potentially fatal complication. Timely activation of the deep brain stimulation system may be important in accelerating the patient's recovery.

  3. Prolonged repeated acupuncture stimulation induces habituation effects in pain-related brain areas: an FMRI study.

    Directory of Open Access Journals (Sweden)

    Chuanfu Li

    Full Text Available Most previous studies of brain responses to acupuncture were designed to investigate the acupuncture instant effect while the cumulative effect that should be more important in clinical practice has seldom been discussed. In this study, the neural basis of the acupuncture cumulative effect was analyzed. For this experiment, forty healthy volunteers were recruited, in which more than 40 minutes of repeated acupuncture stimulation was implemented at acupoint Zhusanli (ST36. Three runs of acupuncture fMRI datasets were acquired, with each run consisting of two blocks of acupuncture stimulation. Besides general linear model (GLM analysis, the cumulative effects of acupuncture were analyzed with analysis of covariance (ANCOVA to find the association between the brain response and the cumulative duration of acupuncture stimulation in each stimulation block. The experimental results showed that the brain response in the initial stage was the strongest although the brain response to acupuncture was time-variant. In particular, the brain areas that were activated in the first block and the brain areas that demonstrated cumulative effects in the course of repeated acupuncture stimulation overlapped in the pain-related areas, including the bilateral middle cingulate cortex, the bilateral paracentral lobule, the SII, and the right thalamus. Furthermore, the cumulative effects demonstrated bimodal characteristics, i.e. the brain response was positive at the beginning, and became negative at the end. It was suggested that the cumulative effect of repeated acupuncture stimulation was consistent with the characteristic of habituation effects. This finding may explain the neurophysiologic mechanism underlying acupuncture analgesia.

  4. Phasic Burst Stimulation: A Closed-Loop Approach to Tuning Deep Brain Stimulation Parameters for Parkinson's Disease.

    Directory of Open Access Journals (Sweden)

    Abbey B Holt

    2016-07-01

    Full Text Available We propose a novel, closed-loop approach to tuning deep brain stimulation (DBS for Parkinson's disease (PD. The approach, termed Phasic Burst Stimulation (PhaBS, applies a burst of stimulus pulses over a range of phases predicted to disrupt pathological oscillations seen in PD. Stimulation parameters are optimized based on phase response curves (PRCs, which would be measured from each patient. This approach is tested in a computational model of PD with an emergent population oscillation. We show that the stimulus phase can be optimized using the PRC, and that PhaBS is more effective at suppressing the pathological oscillation than a single phasic stimulus pulse. PhaBS provides a closed-loop approach to DBS that can be optimized for each patient.

  5. Phasic Burst Stimulation: A Closed-Loop Approach to Tuning Deep Brain Stimulation Parameters for Parkinson's Disease.

    Science.gov (United States)

    Holt, Abbey B; Wilson, Dan; Shinn, Max; Moehlis, Jeff; Netoff, Theoden I

    2016-07-01

    We propose a novel, closed-loop approach to tuning deep brain stimulation (DBS) for Parkinson's disease (PD). The approach, termed Phasic Burst Stimulation (PhaBS), applies a burst of stimulus pulses over a range of phases predicted to disrupt pathological oscillations seen in PD. Stimulation parameters are optimized based on phase response curves (PRCs), which would be measured from each patient. This approach is tested in a computational model of PD with an emergent population oscillation. We show that the stimulus phase can be optimized using the PRC, and that PhaBS is more effective at suppressing the pathological oscillation than a single phasic stimulus pulse. PhaBS provides a closed-loop approach to DBS that can be optimized for each patient. PMID:27415832

  6. Phasic Burst Stimulation: A Closed-Loop Approach to Tuning Deep Brain Stimulation Parameters for Parkinson’s Disease

    Science.gov (United States)

    Holt, Abbey B.; Wilson, Dan; Moehlis, Jeff; Netoff, Theoden I.

    2016-01-01

    We propose a novel, closed-loop approach to tuning deep brain stimulation (DBS) for Parkinson’s disease (PD). The approach, termed Phasic Burst Stimulation (PhaBS), applies a burst of stimulus pulses over a range of phases predicted to disrupt pathological oscillations seen in PD. Stimulation parameters are optimized based on phase response curves (PRCs), which would be measured from each patient. This approach is tested in a computational model of PD with an emergent population oscillation. We show that the stimulus phase can be optimized using the PRC, and that PhaBS is more effective at suppressing the pathological oscillation than a single phasic stimulus pulse. PhaBS provides a closed-loop approach to DBS that can be optimized for each patient. PMID:27415832

  7. Differential responsiveness of the right parahippocampal region to electrical stimulation in fixed human brains: Implications for historical surgical stimulation studies?

    Science.gov (United States)

    Rouleau, Nicolas; Persinger, Michael A

    2016-07-01

    If structure dictates function within the living human brain, then the persistence of specific responses to weak electric currents in fixed, deceased brains could reflect "hardwired" properties. Different key structures from the left and right hemispheres of brains that had been fixed for over 20years with ethanol-formalin-acetic acid were stimulated with either 1-Hz, 7-Hz, 10-Hz, 20-Hz, or 30-Hz, sine-wave, square-wave, or pulsed currents while needle-recorded quantitative electroencephalographic responses were obtained. Differential responses occurred only within the right hippocampus and parahippocampal gyrus. The right hippocampus displayed frequency-independent increases in gamma power relative to the left hemispheric homologue. The parahippocampal region responded exclusively to 7-Hz pulsed currents with wideband (8-30Hz) power. These profiles are consistent with dynamic connections associated with memory and consciousness and may partially explain the interactions resultant of pulse type and hemisphere for experiential elicitations during the golden age of surgical stimulations. The results also indicate that there may be an essential "hardwiring" within the human brain that is maintained for decades when it is fixed appropriately. PMID:27208828

  8. Nanomaterial-enabled neural stimulation

    OpenAIRE

    Yongchen eWang; Liang eGuo

    2016-01-01

    Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a h...

  9. Nanomaterial-Enabled Neural Stimulation

    OpenAIRE

    Wang, Yongchen; Guo, Liang

    2016-01-01

    Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a h...

  10. Deep Brain Stimulation for Obsessive-Compulsive Disorder : A Meta-Analysis of Treatment Outcome and Predictors of Response

    NARCIS (Netherlands)

    Alonso, Pino; Cuadras, Daniel; Gabriëls, Loes; Denys, D.; Goodman, Wayne; Greenberg, Ben D; Jimenez-Ponce, Fiacro; Kuhn, Jens; Lenartz, Doris; Mallet, Luc; Nuttin, Bart; Real, Eva; Segalas, Cinto; Schuurman, Rick; Tezenas du Montcel, Sophie; Menchon, Jose M

    2015-01-01

    BACKGROUND: Deep brain stimulation (DBS) has been proposed as an alternative to ablative neurosurgery for severe treatment-resistant Obsessive-Compulsive Disorder (OCD), although with partially discrepant results probably related to differences in anatomical targetting and stimulation conditions. We

  11. Human brain activation during sexual stimulation of the penis

    NARCIS (Netherlands)

    Georgiadis, [No Value; Holstege, G; Georgiadis, Janniko R.

    2005-01-01

    Penile sensory information is essential for reproduction, but almost nothing is known about how sexually salient inputs from the penis are processed in the brain. We used positron emission tomography to measure regional cerebral blood flow (rCBF) during various stages of male sexual performance. Com

  12. A Power-Efficient Wireless System With Adaptive Supply Control for Deep Brain Stimulation.

    Science.gov (United States)

    Lee, Hyung-Min; Park, Hangue; Ghovanloo, Maysam

    2013-09-01

    A power-efficient wireless stimulating system for a head-mounted deep brain stimulator (DBS) is presented. A new adaptive rectifier generates a variable DC supply voltage from a constant AC power carrier utilizing phase control feedback, while achieving high AC-DC power conversion efficiency (PCE) through active synchronous switching. A current-controlled stimulator adopts closed-loop supply control to automatically adjust the stimulation compliance voltage by detecting stimulation site potentials through a voltage readout channel, and improve the stimulation efficiency. The stimulator also utilizes closed-loop active charge balancing to maintain the residual charge at each site within a safe limit, while receiving the stimulation parameters wirelessly from the amplitude-shift-keyed power carrier. A 4-ch wireless stimulating system prototype was fabricated in a 0.5-μm 3M2P standard CMOS process, occupying 2.25 mm². With 5 V peak AC input at 2 MHz, the adaptive rectifier provides an adjustable DC output between 2.5 V and 4.6 V at 2.8 mA loading, resulting in measured PCE of 72 ~ 87%. The adaptive supply control increases the stimulation efficiency up to 30% higher than a fixed supply voltage to 58 ~ 68%. The prototype wireless stimulating system was verified in vitro. PMID:24678126

  13. Visual-spatial memory may be enhanced with theta burst deep brain stimulation of the fornix: a preliminary investigation with four cases.

    Science.gov (United States)

    Miller, Jonathan P; Sweet, Jennifer A; Bailey, Christopher M; Munyon, Charles N; Luders, Hans O; Fastenau, Philip S

    2015-07-01

    Memory loss after brain injury can be a source of considerable morbidity, but there are presently few therapeutic options for restoring memory function. We have previously demonstrated that burst stimulation of the fornix is able to significantly improve memory in a rodent model of traumatic brain injury. The present study is a preliminary investigation with a small group of cases to explore whether theta burst stimulation of the fornix might improve memory in humans. Four individuals undergoing stereo-electroencephalography evaluation for drug-resistant epilepsy were enrolled. All participants were implanted with an electrode into the proximal fornix and dorsal hippocampal commissure on the language dominant (n = 3) or language non-dominant (n = 1) side, and stimulation of this electrode reliably produced a diffuse evoked potential in the head and body of the ipsilateral hippocampus. Each participant underwent testing of verbal memory (Rey Auditory-Verbal Learning Test), visual-spatial memory (Medical College of Georgia Complex Figure Test), and visual confrontational naming (Boston Naming Test Short Form) once per day over at least two consecutive days using novel test forms each day. For 50% of the trials, the fornix electrode was continuously stimulated using a burst pattern (200 Hz in 100 ms trains, five trains per second, 100 µs, 7 mA) and was compared with sham stimulation. Participants and examiners were blinded to whether stimulation was active or not, and the order of stimulation was randomized. The small sample size precluded use of inferential statistics; therefore, data were analysed using descriptive statistics and graphic analysis. Burst stimulation of the fornix was not perceived by any of the participants but was associated with a robust reversible improvement in immediate and delayed performance on the Medical College of Georgia Complex Figure Test. There were no apparent differences on either Rey Auditory-Verbal Learning Test or Boston Naming

  14. Deep brain stimulation of the antero-medial globus pallidus interna for Tourette syndrome.

    Directory of Open Access Journals (Sweden)

    Perminder S Sachdev

    Full Text Available BACKGROUND: We have previously reported the results of Deep Brain Stimulation (DBS of the antero-medial globus pallidus interna (GPi for severe Tourette Syndrome (TS in 11 patients. We extend this case series to 17 patients and a longer follow-up to a maximum of 46 months. METHODS: 17 patients (14 male; mean age 29.1 years, range 17-51 years with severe and medically intractable TS were implanted with Medtronic quadripolar electrodes bilaterally in the antero-medial GPi. The primary outcome measure was the Yale Global Tic Severity Scale (YGTSS. Secondary outcome measures included the Yale-Brown Obsessive Compulsive Scale, Hamilton Depression Rating Scale, Gilles de la Tourette Quality of Life Scale and Global Assessment of Functioning. Follow up was at one month, three months and finally at a mean 24.1 months (range 8-46 months following surgery. RESULTS: Overall, there was a 48.3% reduction in motor tics and a 41.3% reduction in phonic tics at one month, and this improvement was maintained at final follow-up. 12 out of 17 (70.6% patients had a>50% reduction in YGTSS score at final follow up. Only 8 patients required ongoing pharmacotherapy for tics post-surgery. Patients improved significantly on all secondary measures. Adverse consequences included lead breakage in 4 patients, infection (1, transient anxiety (2, dizziness (1, poor balance (1 and worsening of stuttering (1. CONCLUSIONS: This case series provides further support that antero-medial GPi DBS is an effective and well tolerated treatment for a subgroup of severe TS, with benefits sustained up to 4 years.

  15. Temporally Coordinated Deep Brain Stimulation in the Dorsal and Ventral Striatum Synergistically Enhances Associative Learning.

    Science.gov (United States)

    Katnani, Husam A; Patel, Shaun R; Kwon, Churl-Su; Abdel-Aziz, Samer; Gale, John T; Eskandar, Emad N

    2016-01-01

    The primate brain has the remarkable ability of mapping sensory stimuli into motor behaviors that can lead to positive outcomes. We have previously shown that during the reinforcement of visual-motor behavior, activity in the caudate nucleus is correlated with the rate of learning. Moreover, phasic microstimulation in the caudate during the reinforcement period was shown to enhance associative learning, demonstrating the importance of temporal specificity to manipulate learning related changes. Here we present evidence that extends upon our previous finding by demonstrating that temporally coordinated phasic deep brain stimulation across both the nucleus accumbens and caudate can further enhance associative learning. Monkeys performed a visual-motor associative learning task and received stimulation at time points critical to learning related changes. Resulting performance revealed an enhancement in the rate, ceiling, and reaction times of learning. Stimulation of each brain region alone or at different time points did not generate the same effect. PMID:26725509

  16. The phenomenology of deep brain stimulation-induced changes in OCD: an enactive affordance-based model.

    Science.gov (United States)

    de Haan, Sanneke; Rietveld, Erik; Stokhof, Martin; Denys, Damiaan

    2013-01-01

    People suffering from Obsessive-Compulsive Disorder (OCD) do things they do not want to do, and/or they think things they do not want to think. In about 10% of OCD patients, none of the available treatment options is effective. A small group of these patients is currently being treated with deep brain stimulation (DBS). DBS involves the implantation of electrodes in the brain. These electrodes give a continuous electrical pulse to the brain area in which they are implanted. It turns out that patients may experience profound changes as a result of DBS treatment. It is not just the symptoms that change; patients rather seem to experience a different way of being in the world. These global effects are insufficiently captured by traditional psychiatric scales, which mainly consist of behavioral measures of the severity of the symptoms. In this article we aim to capture the changes in the patients' phenomenology and make sense of the broad range of changes they report. For that we introduce an enactive, affordance-based model that fleshes out the dynamic interactions between person and world in four aspects. The first aspect is the patients' experience of the world. We propose to specify the patients' world in terms of a field of affordances, with the three dimensions of broadness of scope ("width" of the field), temporal horizon ("depth"), and relevance of the perceived affordances ("height"). The second aspect is the person-side of the interaction, that is, the patients' self-experience, notably their moods and feelings. Thirdly, we point to the different characteristics of the way in which patients relate to the world. And lastly, the existential stance refers to the stance that patients take toward the changes they experience: the second-order evaluative relation to their interactions and themselves. With our model we intend to specify the notion of being in the world in order to do justice to the phenomenological effects of DBS treatment. PMID:24133438

  17. The study on a real-time remote monitoring system for Parkinson's disease patients with deep brain stimulators.

    Science.gov (United States)

    Chen, Yue; Hao, Hongwei; Chen, Hao; Tian, Ye; Li, Luming

    2014-01-01

    The Deep Brain Stimulation (DBS) has become a well-accepted treatment for Parkinson's disease patients around the world. However, postoperative care of the stimulators usually puts a heavy burden on the patients' families, especially in China. To solve the problem, this study developed a real-time remote monitoring system for deep brain stimulators. Based on Internet technologies, the system offers remote adjustment service so that in vivo stimulators could be programmed at patients' home by clinic caregivers. We tested the system on an experimental condition and the results have proved that this early exploration of remote monitoring deep brain stimulators was successful. PMID:25570219

  18. Effect of Repetitive Transcranial Magnetic Stimulation on Patients with Brain Injury and Dysphagia

    OpenAIRE

    Kim, Leesuk; Chun, Min Ho; Kim, Bo Ryun; Lee, Sook Joung

    2011-01-01

    Objective To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) on recovery of the swallowing function in patients with a brain injury. Method Patients with a brain injury and dysphagia were enrolled. Patients were randomly assigned to sham, and low and high frequency stimulation groups. We performed rTMS at 100% of motor evoked potential (MEP) threshold and a 5 Hz frequency for 10 seconds and then repeated this every minute in the high frequency group. In the low f...

  19. Intraoperative functional MRI as a new approach to monitor deep brain stimulation in Parkinson's disease

    International Nuclear Information System (INIS)

    This article deals with technical aspects of intraoperative functional magnetic resonance imaging (fMRI) for monitoring the effect of deep brain stimulation (DBS) in a patient with Parkinson's disease. Under motor activation, therapeutic high-frequency stimulation of the subthalamic nucleus was accompanied by an activation decrease in the contralateral primary sensorimotor cortex and the ipsilateral cerebellum. Furthermore, an activation increase in the contralateral basal ganglia and insula region were detected. These findings demonstrate that fMRI constitutes a promising clinical application for investigating brain activity changes induced by DBS. (orig.)

  20. Invasive and transcranial photoacoustic imaging of the vascular response to brain electrical stimulation

    Science.gov (United States)

    Tsytsarev, Vassiliy; Yao, Junjie; Hu, Song; Li, Li; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

    2010-02-01

    Advances in the brain functional imaging greatly facilitated the understanding of neurovascular coupling. For monitoring of the microvascular response to the brain electrical stimulation in vivo we used optical-resolution photoacoustic microscopy (OR-PAM) through the cranial openings as well as transcranially. Both types of the vascular response, vasoconstriction and vasodilatation, were clearly observed with good spatial and temporal resolution. Obtained results confirm one of the primary points of the neurovascular coupling theory that blood vessels could present vasoconstriction or vasodilatation in response to electrical stimulation, depending on the balance between inhibition and excitation of the different parts of the elements of the neurovascular coupling system.

  1. A Prospective Pilot Trial for Pallidal Deep Brain Stimulation in Huntington’s Disease

    OpenAIRE

    Wojtecki, Lars; Groiss, Stefan J.; Ferrea, Stefano; Elben, Saskia; Hartmann, Christian J.; Dunnett, Stephen B; Rosser, Anne; Saft, Carsten; Südmeyer, Martin; Ohmann, Christian; Schnitzler, Alfons; Vesper, Jan

    2015-01-01

    Background Movement disorders in Huntington’s disease are often medically refractive. The aim of the trial was assessment of procedure safety of deep brain stimulation, equality of internal- and external-pallidal stimulation and efficacy followed-up for 6 months in a prospective pilot trial. Methods In a controlled double-blind phase six patients (four chorea-dominant, two Westphal-variant) with predominant movement disorder were randomly assigned to either the sequence of 6-week i...

  2. Novel methods and circuits for field shaping in deep brain stimulation

    OpenAIRE

    Valente, V.

    2011-01-01

    Deep Brain Stimulation (DBS) is a clinical tool used to treat various neurological disorders, including tremor, Parkinson’s disease (PD) and dystonia. Today’s routine use of this therapy is a result of the pioneering work of Benabid and colleagues, who assessed the benefits of applying high-frequency stimulation to the ventral intermediate nucleus and reported substantial long-term improvements in PD patients. Clinical applications of DBS, however, have preceded research and le...

  3. The Polarity-Dependent Effects of the Bilateral Brain Stimulation on Working Memory

    OpenAIRE

    Keshvari, Fatemeh; Pouretemad, Hamid-Reza; Ekhtiari, Hamed

    2013-01-01

    Introduction Working memory plays a critical role in cognitive processes which are central to our daily life. Neuroimaging studies have shown that one of the most important areas corresponding to the working memory is the dorsolateral prefrontal cortex (DLFPC). This study was aimed to assess whether bilateral modulation of the DLPFC using a noninvasive brain stimulation, namely transcranial direct current stimulation (tDCS), modifies the working memory function in healthy adults. Methods In a...

  4. Transcranial magnetic stimulation for investigating causal brain-behavioral relationships and their time course.

    Science.gov (United States)

    Sliwinska, Magdalena W; Vitello, Sylvia; Devlin, Joseph T

    2014-01-01

    Transcranial magnetic stimulation (TMS) is a safe, non-invasive brain stimulation technique that uses a strong electromagnet in order to temporarily disrupt information processing in a brain region, generating a short-lived "virtual lesion." Stimulation that interferes with task performance indicates that the affected brain region is necessary to perform the task normally. In other words, unlike neuroimaging methods such as functional magnetic resonance imaging (fMRI) that indicate correlations between brain and behavior, TMS can be used to demonstrate causal brain-behavior relations. Furthermore, by varying the duration and onset of the virtual lesion, TMS can also reveal the time course of normal processing. As a result, TMS has become an important tool in cognitive neuroscience. Advantages of the technique over lesion-deficit studies include better spatial-temporal precision of the disruption effect, the ability to use participants as their own control subjects, and the accessibility of participants. Limitations include concurrent auditory and somatosensory stimulation that may influence task performance, limited access to structures more than a few centimeters from the surface of the scalp, and the relatively large space of free parameters that need to be optimized in order for the experiment to work. Experimental designs that give careful consideration to appropriate control conditions help to address these concerns. This article illustrates these issues with TMS results that investigate the spatial and temporal contributions of the left supramarginal gyrus (SMG) to reading. PMID:25079670

  5. Brain Abnormalities in HIV and Stimulant Users: Interventions and Prevention

    OpenAIRE

    Chang, Linda; Shoptaw, Steven; Normand, Jacques

    2013-01-01

    The session, “HIV and other Infectious Diseases,” was chaired by Dr. Jacques Normand, Director of the AIDS Research Program of the U.S. National Institute on Drug Abuse. The two presenters (and their presentation topics) were: Dr. Linda Chang (“Neural Correlates of Cognitive Deficits and Training Effects on Brain Function in HIV-infected Individuals”) and Dr. Steven Shoptaw (“HIV Prevention in Substance Users”).

  6. Pillar-shaped stimulus electrode array for high-efficiency stimulation of fully implantable epiretinal prosthesis

    International Nuclear Information System (INIS)

    We developed a pillar-shaped microelectrode array (MEA) with varying heights for enhancing the spherical conformity of fully implantable epiretinal prosthesis comprising a 3D stacked retinal chip. The fabricated MEA is composed of 100 pillar electrodes with heights ranging from 60 to 80 µm. The Pt-coated Cu pillar electrode with a surface diameter of 70 µm and a height of 75 µm and the Pt planar electrode with a surface diameter of 70 µm have 24.6 and 125 kΩ impedances, respectively, at 1 kHz in vitro experiment. The pillar electrode shows lower impedance than the planar electrode because of a larger surface area. However, to avoid cross-talking between pillar electrodes, we developed a sidewall passivation process of the pillar electrode by using the surface tension of polyimide. The impedance of the isolated pillar electrode 116 kΩ at 1 kHz is similar to the impedance of the planar electrode, because they have similar electrode surface areas. The pillar-shaped MEA shows a better spherical conformity. (paper)

  7. Multiple-input single-output closed-loop isometric force control using asynchronous intrafascicular multi-electrode stimulation.

    Science.gov (United States)

    Frankel, Mitchell A; Dowden, Brett R; Mathews, V John; Normann, Richard A; Clark, Gregory A; Meek, Sanford G

    2011-06-01

    Although asynchronous intrafascicular multi-electrode stimulation (IFMS) can evoke fatigue-resistant muscle force, a priori determination of the necessary stimulation parameters for precise force production is not possible. This paper presents a proportionally-modulated, multiple-input single-output (MISO) controller that was designed and experimentally validated for real-time, closed-loop force-feedback control of asynchronous IFMS. Experiments were conducted on anesthetized felines with a Utah Slanted Electrode Array implanted in the sciatic nerve, either acutely or chronically ( n = 1 for each). Isometric forces were evoked in plantar-flexor muscles, and target forces consisted of up to 7 min of step, sinusoidal, and more complex time-varying trajectories. The controller was successful in evoking steps in force with time-to-peak of less than 0.45 s, steady-state ripple of less than 7% of the mean steady-state force, and near-zero steady-state error even in the presence of muscle fatigue, but with transient overshoot of near 20%. The controller was also successful in evoking target sinusoidal and complex time-varying force trajectories with amplitude error of less than 0.5 N and time delay of approximately 300 ms. This MISO control strategy can potentially be used to develop closed-loop asynchronous IFMS controllers for a wide variety of multi-electrode stimulation applications to restore lost motor function. PMID:21385670

  8. Modeling the effects of noninvasive transcranial brain stimulation at the biophysical, network, and cognitive Level

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Bergmann, Til Ole; Herz, Damian Marc;

    2015-01-01

    Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how the...... emerge in the context of rapid automatic responses or in the context of slow deliberate responses. We argue that these complementary modeling approaches facilitate the use of NTBS as a means of dissecting the causal architecture of cognitive systems of the human brain.......Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how these...... approaches advance the scientific potential of NTBS as an interventional tool in cognitive neuroscience. (i) Leveraging the anatomical information provided by structural imaging, the electric field distribution in the brain can be modeled and simulated. Biophysical modeling approaches generate testable...

  9. Kappa opioid receptors stimulate phosphoinositide turnover in rat brain

    International Nuclear Information System (INIS)

    The effects of various subtype-selective opioid agonists and antagonists on the phosphoinositide (PI) turnover response were investigated in the rat brain. The κ-agonists U-50,488H and ketocyclazocine produced a concentration-dependent increase in the accumulation of IP's in hippocampal slices. The other κ-agonists Dynorphin-A (1-13) amide, and its protected analog D[Ala]2-dynorphin-A (1-13) amide also produced a significant increase in the formation of [3H]-IP's, whereas the μ-selective agonists [D-Ala2-N-Me-Phe4-Gly5-ol]-enkephalin and morphine and the δ-selective agonist [D-Pen2,5]-enkephalin were ineffective. The increase in IP's formation elicited by U-50,488H was partially antagonized by naloxone and more completely antagonized by the κ-selective antagonists nor-binaltorphimine and MR 2266. The formation of IP's induced by U-50,488H varies with the regions of the brain used, being highest in hippocampus and amygdala, and lowest in striatum and pons-medullar. The results indicate that brain κ- but neither μ- nor δ- receptors are coupled to the PI turnover response

  10. Kappa opioid receptors stimulate phosphoinositide turnover in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Periyasamy, S.; Hoss, W. (Univ. of Toledo, OH (USA))

    1990-01-01

    The effects of various subtype-selective opioid agonists and antagonists on the phosphoinositide (PI) turnover response were investigated in the rat brain. The {kappa}-agonists U-50,488H and ketocyclazocine produced a concentration-dependent increase in the accumulation of IP's in hippocampal slices. The other {kappa}-agonists Dynorphin-A (1-13) amide, and its protected analog D(Ala){sup 2}-dynorphin-A (1-13) amide also produced a significant increase in the formation of ({sup 3}H)-IP's, whereas the {mu}-selective agonists (D-Ala{sup 2}-N-Me-Phe{sup 4}-Gly{sup 5}-ol)-enkephalin and morphine and the {delta}-selective agonist (D-Pen{sup 2,5})-enkephalin were ineffective. The increase in IP's formation elicited by U-50,488H was partially antagonized by naloxone and more completely antagonized by the {kappa}-selective antagonists nor-binaltorphimine and MR 2266. The formation of IP's induced by U-50,488H varies with the regions of the brain used, being highest in hippocampus and amygdala, and lowest in striatum and pons-medullar. The results indicate that brain {kappa}- but neither {mu}- nor {delta}- receptors are coupled to the PI turnover response.

  11. Stimulating brain tissue with bright light alters functional connectivity in brain at the resting state

    OpenAIRE

    Timo Takala; Markku Timonen; Juha Nikkinen; Jukka Remes; Antti Aunio; Ahmed Abou-Elseoud; Juuso Nissilä; Tuomo Starck; Osmo Tervonen; Vesa Kiviniemi

    2012-01-01

    Light is considered to modulate human brain function only via the retinal pathway, a way of thinking that we aimed to challenge in the present study. Literature provides evidence of inherent phototransduction for instance in the rat brain and there are potentially photosensitive opsin proteins like melanopsin and panopsin in the human brain too. In order to investigate a short term response, functional connectivity changes of the brain were studied in the resting state with functional magneti...

  12. The phenomenology of Deep Brain Stimulation-induced changes in OCD: An enactive affordance-based model

    Directory of Open Access Journals (Sweden)

    Sanneke ede Haan

    2013-10-01

    Full Text Available People suffering from Obsessive-Compulsive Disorder (OCD do things they do not want to do, and/or they think things they do not want to think. In about 10 percent of OCD patients, none of the available treatment options is effective. A small group of these patients is currently being treated with deep brain stimulation (DBS. Deep brain stimulation involves the implantation of electrodes in the brain. These electrodes give a continuous electrical pulse to the brain area in which they are implanted. It turns out that patients may experience profound changes as a result of DBS treatment. It is not just the symptoms that change; patients rather seem to experience a different way of being in the world. These global effects are insufficiently captured by traditional psychiatric scales, which mainly consist of behavioural measures of the severity of the symptoms.In this article we aim to capture the changes in the patients’ phenomenology and make sense of the broad range of changes they report. For that we introduce an enactive, affordance-based model that fleshes out the dynamic interactions between person and world in four aspects. The first aspect is the patients’ experience of the world. We propose to specify the patients’ world in terms of a field of affordances, with the three dimensions of broadness of scope (‘width’ of the field, temporal horizon (‘depth’, and relevance of the perceived affordances (‘height’. The second aspect is the person-side of the interaction, that is, the patients’ self-experience, notably their moods and feelings. Thirdly, we point to the different characteristics of the way in which patients relate to the world. And lastly, the existential stance refers to the stance that patients take towards the changes they experience: the second-order evaluative relation to their interactions and themselves. With our model we intend to specify the notion of being in the world in order to do justice to the

  13. Development of intraoperative electrochemical detection: wireless instantaneous neurochemical concentration sensor for deep brain stimulation feedback

    OpenAIRE

    Van Gompel, Jamie J.; Chang, Su-Youne; Goerss, Stephan J.; Kim, In Yong; Kimble, Christopher; Bennet, Kevin E.; Lee, Kendall H.

    2010-01-01

    Deep brain stimulation (DBS) is effective when there appears to be a distortion in the complex neurochemical circuitry of the brain. Currently, the mechanism of DBS is incompletely understood; however, it has been hypothesized that DBS evokes release of neurochemicals. Well-established chemical detection systems such as microdialysis and mass spectrometry are impractical if one is assessing changes that are happening on a second-to-second time scale or for chronically used implanted recording...

  14. Deep brain stimulation modulates synchrony within spatially and spectrally distinct resting state networks in Parkinson's disease

    OpenAIRE

    Oswal, A; Beudel, M; Zrinzo, L; Limousin, P.; Hariz, M; Foltynie, T.; Litvak, V; P Brown

    2016-01-01

    Chronic dopamine depletion in Parkinson's disease leads to progressive motor and cognitive impairment, which is associated with the emergence of characteristic patterns of synchronous oscillatory activity within cortico-basal-ganglia circuits. Deep brain stimulation of the subthalamic nucleus is an effective treatment for Parkinson's disease, but its influence on synchronous activity in cortico-basal-ganglia loops remains to be fully characterized. Here, we demonstrate that deep brain stimula...

  15. Electrode alignment of transverse tripoles using a percutaneous triple-lead approach in spinal cord stimulation

    Science.gov (United States)

    Sankarasubramanian, V.; Buitenweg, J. R.; Holsheimer, J.; Veltink, P.

    2011-02-01

    The aim of this modeling study is to determine the influence of electrode alignment of transverse tripoles on the paresthesia coverage of the pain area in spinal cord stimulation, using a percutaneous triple-lead approach. Transverse tripoles, comprising a central cathode and two lateral anodes, were modeled on the low-thoracic vertebral region (T10-T12) using percutaneous triple-lead configurations, with the center lead on the spinal cord midline. The triple leads were oriented both aligned and staggered. In the staggered configuration, the anodes were offset either caudally (caudally staggered) or rostrally (rostrally staggered) with respect to the midline cathode. The transverse tripolar field steering with the aligned and staggered configurations enabled the estimation of dorsal column fiber thresholds (IDC) and dorsal root fiber thresholds (IDR) at various anodal current ratios. IDC and IDR were considerably higher for the aligned transverse tripoles as compared to the staggered transverse tripoles. The aligned transverse tripoles facilitated deeper penetration into the medial dorsal columns (DCs). The staggered transverse tripoles always enabled broad and bilateral DC activation, at the expense of mediolateral steerability. The largest DC recruited area was obtained with the rostrally staggered transverse tripole. Transverse tripolar geometries, using percutaneous leads, allow for selective targeting of either medial or lateral DC fibers, if and only if the transverse tripole is aligned. Steering of anodal currents between the lateral leads of the staggered transverse tripoles cannot target medially confined populations of DC fibers in the spinal cord. An aligned transverse tripolar configuration is strongly recommended, because of its ability to provide more post-operative flexibility than other configurations.

  16. Device-based brain stimulation to augment fear extinction: implications for PTSD treatment and beyond.

    Science.gov (United States)

    Marin, Marie-France; Camprodon, Joan A; Dougherty, Darin D; Milad, Mohammed R

    2014-04-01

    Conditioned fear acquisition and extinction paradigms have been widely used both in animals and humans to examine the neurobiology of emotional memory. Studies have also shown that patients suffering from posttraumatic stress disorder (PTSD) exhibit deficient extinction recall along with dysfunctional activation of the fear extinction network, including the ventromedial prefrontal cortex, amygdala, and hippocampus. A great deal of overlap exists between this fear extinction network and brain regions associated with symptom severity in PTSD. This suggests that the neural nodes of fear extinction could be targeted to reduce behavioral deficits that may subsequently translate into symptom improvement. In this article, we discuss potential applications of brain stimulation and neuromodulation methods, which, combined with a mechanistic understanding of the neurobiology of fear extinction, could be used to further our understanding of the pathophysiology of anxiety disorders and develop novel therapeutic tools. To this end, we discuss the following stimulation approaches: deep-brain stimulation, vagus nerve stimulation, transcranial direct current stimulation, and transcranial magnetic stimulation. We propose new translational research avenues that, from a systems neuroscience perspective, aim to expand our understanding of circuit dynamics and fear processing toward the practical development of clinical tools, to be used alone or in combination with behavioral therapies. PMID:24634247

  17. Effects of Vestibular Prosthesis Electrode Implantation and Stimulation on Hearing in Rhesus Monkeys

    OpenAIRE

    Dai, Chenkai; Fridman, Gene Y.; Della Santina, Charles C.

    2010-01-01

    To investigate the effects of vestibular prosthesis electrode implantation and activation on hearing in rhesus monkeys, we measured auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE) in four rhesus monkeys before and after unilateral implantation of vestibular prosthesis electrodes in each of 3 left semicircular canals (SCC). Each of the 3 left SCCs were implanted with electrodes via a transmastoid approach. Right ears, which served as controls, were not s...

  18. Neurodoping: brain stimulation as a performance-enhancing measure.

    Science.gov (United States)

    Davis, Nick J

    2013-08-01

    Doping may be defined, broadly, as the use of unauthorised means to increase performance in sport. Doping is most commonly associated with the use of drugs. In this paper, I discuss the use of emerging techniques for the modulation of brain activity in healthy people using electric or magnetic fields, and suggest how they might be used to enhance physical and mental performance in sports. I will suggest that neurodoping may have different uses in different sports, and I argue that each sport must determine whether neurodoping should be considered as cheating, or should be considered a legitimate aid to training or performance. PMID:23504390

  19. Comparison of proximally versus distally placed spatially distributed sequential stimulation electrodes in a dynamic knee extension task

    Directory of Open Access Journals (Sweden)

    Marco Laubacher

    2016-06-01

    Full Text Available Spatially distributed sequential stimulation (SDSS has demonstrated substantial power output and fatigue benefits compared to single electrode stimulation (SES in the application of functional electrical stimulation (FES. This asymmetric electrode setup brings new possibilities but also new questions since precise placement of the electrodes is one critical factor for good muscle activation. The aim of this study was to compare the power output, fatigue and activation properties of proximally versus distally placed SDSS electrodes in an isokinetic knee extension task simulating knee movement during recumbent cycling. M. vastus lateralis and medialis of seven able-bodied subjects were stimulated with rectangular bi-phasic pulses of constant amplitude of 40 mA and at an SDSS frequency of 35 Hz for 6 min on both legs with both setups (i.e. n=14. Torque was measured during knee-extension movement by a dynamometer at an angular velocity of 110 deg/s. Mean power, peak power and activation time were calculated and compared for the initial and final stimulation phases, together with an overall fatigue index. Power output values (Pmean, Ppeak were scaled to a standardised reference input pulse width of 100 μs (Pmean,s, Ppeak,s. The initial evaluation phase showed no significant differences between the two setups for all outcome measures. Ppeak and Ppeak,s were both significantly higher in the final phase for the distal setup (25.4 ± 8.1 W vs. 28.2 ± 6.2 W, p=0.0062 and 34.8 ± 9.5 W vs. 38.9 ± 6.7 W, p=0.021, respectively. With distal SDSS, there was modest evidence of higher Pmean and Pmean,s (p=0.071, p=0.14, respectively but of longer activation time (p=0.096. The rate of fatigue was similar for both setups. For practical FES applications, distal placement of the SDSS electrodes is preferable.

  20. The effects of subthalamic deep brain stimulation on metaphor comprehension and language abilities in Parkinson's disease.

    Science.gov (United States)

    Tremblay, Christina; Macoir, Joël; Langlois, Mélanie; Cantin, Léo; Prud'homme, Michel; Monetta, Laura

    2015-02-01

    The effects of subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) on different language abilities are still controversial and its impact on high-level language abilities such as metaphor comprehension has been overlooked. The aim of this study was to determine the effects of STN electrical stimulation on metaphor comprehension and language abilities such as lexical and semantic capacities. Eight PD individuals with bilateral STN-DBS were first evaluated OFF-DBS and, at least seven weeks later, ON-DBS. Performance on metaphor comprehension, lexical decision, word association and verbal fluency tasks were compared ON and OFF-DBS in addition to motor symptoms evaluation. STN stimulation had a significant beneficial effect on motor symptoms in PD. However, this stimulation did not have any effect on metaphor comprehension or any other cognitive ability evaluated in this study. These outcomes suggest that STN stimulation may have dissociable effects on motor and language functions. PMID:25577507

  1. Rapid subthalamic nucleus deep brain stimulation lead placement utilising CT/MRI fusion, microelectrode recording and test stimulation

    International Nuclear Information System (INIS)

    Subthalamic nucleus (STN) deep brain stimulation (DBS) has become an established treatment strategy for patients with medically refractory Parkinson's disease (PD). There are however numerous strategies employed for STN lead placement. Variations include method of STN localisation, use of microelectrode recording, number of microelectrode recording passes and time taken for the procedure. We describe a relatively simple and rapid technique of STN lead placement utilising CT/ MRI image fusion, microelectrode recording and test stimulation. The first 58 consecutive patients undergoing STN DBS were assessed pre- and post-operatively. UPDRS scores, medication use and any surgical complication were assessed. Bilateral STN DBS was an efficacious treatment option for medically refractory PD. We have described a technique which can be performed with effect and low morbidity, and in a time which is well tolerated by patients. (author)

  2. [Does Prefrontal Noninvasive Brain Stimulation Alleviating Symptoms in Depression and Schizophrenia Impact Mood and Emotion Processing?].

    Science.gov (United States)

    Psomiades, Marion; Fonteneau, Clara; Suaud-Chagny, Marie-Françoise; Haesebaert, Frédéric; Brunelin, Jérôme

    2016-01-01

    Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are noninvasive brain stimulation techniques currently used as therapeutic tools in various psychiatric conditions. Applied over the dorsolateral prefrontal cortex (DLPFC), they showed their efficacy in reducing drug-resistant symptoms in patients with major depression and in patients with schizophrenia with predominantly negative symptoms. The DLPFC is a brain structure involved in the expression of these symptoms as well as in other dysfunctional functions observed in theses conditions such as emotional processes. The goal of this review is to establish whether or not a link exists between clinical improvements and modulation of emotional processes following the stimulation of the DLPFC in both conditions. The data collected show that improved emotional processes is not linked to a clinical improvement neither in patients with depression nor in patients with negative schizophrenia. Our results suggests that although sharing common brain structures, the brain networks involved in both symptoms and in emotional processes would be separate. PMID:27570958

  3. Free-living energy expenditure reduced after deep brain stimulation surgery for Parkinson's disease

    DEFF Research Database (Denmark)

    Jørgensen, Hans Ulrik; Werdelin, Lene; Lokkegaard, Annemette;

    2012-01-01

    with deep brain stimulation in the subthalamic nucleus (STN-DBS) is now considered the gold standard in fluctuating PD. Many patients experience a gain of weight following the surgery. The aim of this study was to identify possible mechanisms, which may contribute to body weight gain in patients with...

  4. Using non-invasive brain stimulation to augment motor training-induced plasticity

    Directory of Open Access Journals (Sweden)

    Pascual-Leone Alvaro

    2009-03-01

    Full Text Available Abstract Therapies for motor recovery after stroke or traumatic brain injury are still not satisfactory. To date the best approach seems to be the intensive physical therapy. However the results are limited and functional gains are often minimal. The goal of motor training is to minimize functional disability and optimize functional motor recovery. This is thought to be achieved by modulation of plastic changes in the brain. Therefore, adjunct interventions that can augment the response of the motor system to the behavioural training might be useful to enhance the therapy-induced recovery in neurological populations. In this context, noninvasive brain stimulation appears to be an interesting option as an add-on intervention to standard physical therapies. Two non-invasive methods of inducing electrical currents into the brain have proved to be promising for inducing long-lasting plastic changes in motor systems: transcranial magnetic stimulation (TMS and transcranial direct current stimulation (tDCS. These techniques represent powerful methods for priming cortical excitability for a subsequent motor task, demand, or stimulation. Thus, their mutual use can optimize the plastic changes induced by motor practice, leading to more remarkable and outlasting clinical gains in rehabilitation. In this review we discuss how these techniques can enhance the effects of a behavioural intervention and the clinical evidence to date.

  5. The Third Annual Deep Brain Stimulation Think Tank: A Review of Emerging Issues and Technologies

    OpenAIRE

    P. Justin eRossi; Aysegul eGunduz; Jack eJudy; Linda eWilson; Andre eMachado; James J Giordano; W. Jeff eElias; Alterman, Ron L.; Rossi, Marvin A.; Butson, Christopher L.; Fox, Michael D.; McIntyre, Cameron C.; Nader ePouratian; Swann, Nicole C.; Coralie ede Hemptinne

    2016-01-01

    This review summarizes the most contemporary clinical, electrophysiological, imaging, and computational work on DBS for the treatment of neurological and neuropsychiatric disease. Significant innovations of the past year are emphasized; these advances were presented at the 3rd Annual Deep Brain Stimulation Think Tank. The Think Tank’s contributors represent a unique multidisciplinary ensemble of expert neurologists, neurosurgeons, neuropsychologists, psychiatrists, scientists, engineers, and ...

  6. Perturbation and Nonlinear Dynamic Analysis of Acoustic Phonatory Signal in Parkinsonian Patients Receiving Deep Brain Stimulation

    Science.gov (United States)

    Lee, Victoria S.; Zhou, Xiao Ping; Rahn, Douglas A., III; Wang, Emily Q.; Jiang, Jack J.

    2008-01-01

    Nineteen PD patients who received deep brain stimulation (DBS), 10 non-surgical (control) PD patients, and 11 non-pathologic age- and gender-matched subjects performed sustained vowel phonations. The following acoustic measures were obtained on the sustained vowel phonations: correlation dimension (D[subscript 2]), percent jitter, percent shimmer,…

  7. Subthalamic Nucleus Deep Brain Stimulation Changes Velopharyngeal Control in Parkinson's Disease

    Science.gov (United States)

    Hammer, Michael J.; Barlow, Steven M.; Lyons, Kelly E.; Pahwa, Rajesh

    2011-01-01

    Purpose: Adequate velopharyngeal control is essential for speech, but may be impaired in Parkinson's disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on velopharyngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of velopharyngeal…

  8. Cognitive Functioning in Children with Pantothenate-Kinase-Associated Neurodegeneration Undergoing Deep Brain Stimulation

    Science.gov (United States)

    Mahoney, Rachel; Selway, Richard; Lin, Jean-Pierre

    2011-01-01

    Aim: To examine the cognitive functioning of young people with pantothenate-kinase-associated neurodegeneration (PKAN) after pallidal deep brain stimulation (DBS). PKAN is characterized by progressive generalized dystonia and has historically been associated with cognitive decline. With growing evidence that DBS can improve motor function in…

  9. Cognitive effects of deep brain stimulation in patients with obsessive-compulsive disorder

    NARCIS (Netherlands)

    Mantione, Mariska; Nieman, Dorien; Figee, Martijn; van den Munckhof, Pepijn; Schuurman, Rick; Denys, D.

    2015-01-01

    BACKGROUND: Deep brain stimulation (DBS) is a promising treatment for treatment-refractory obsessive-compulsive disorder (OCD). However, the effects of DBS on cognitive functioning remain unclear. Therefore, we aimed to assess cognitive safety of DBS for treatment-refractory OCD and the association

  10. Clinical Outcome and Mechanisms of Deep Brain Stimulation for Obsessive-Compulsive Disorder

    NARCIS (Netherlands)

    van Westen, Maarten; Rietveld, Erik; Figee, Martijn; Denys, D.

    2015-01-01

    Clinical outcome of deep brain stimulation (DBS) for obsessive-compulsive disorder (OCD) shows robust effects in terms of a mean Yale-Brown Obsessive-Compulsive Scale (YBOCS) reduction of 47.7 % and a mean response percentage (minimum 35 % YBOCS reduction) of 58.2 %. It appears that most patients re

  11. Deep brain stimulation for obsessive-compulsive disorders : long-term analysis of quality of life

    NARCIS (Netherlands)

    Ooms, Pieter; Mantione, Mariska; Figee, Martijn; Schuurman, P Richard; van den Munckhof, Pepijn; Denys, D.

    2014-01-01

    OBJECTIVE: To evaluate the long-term effects of deep brain stimulation (DBS) on quality of life (QOL) in therapy-refractory obsessive-compulsive disorder (OCD) patients. DESIGN: 16 patients who met Diagnostic and Statistical Manual of Mental Disorders (4th ed) (DSM-IV) criteria for OCD and were cons

  12. Hunger dependence of electrical brain self-stimulation in the pigeon

    OpenAIRE

    Delius, Juan; Pellander, Kirsti

    1982-01-01

    Contrary to recent evidence, further data showing that intracranial self-stimulation behaviour in the pigeon is frequently hunger-dependent is reported. A compilation of reinforcing brain loci in the pigeon suggests an association with two dopaminergic systems, the paleostriatal complex and the nucleus basalis system, the latter being known to be involved in the control of feeding.

  13. Semi-automatic microdrive system for positioning electrodes during electrophysiological recordings from rat brain

    Science.gov (United States)

    Dabrowski, Piotr; Kublik, Ewa; Mozaryn, Jakub

    2015-09-01

    Electrophysiological recording of neuronal action potentials from behaving animals requires portable, precise and reliable devices for positioning of multiple microelectrodes in the brain. We propose a semi-automatic microdrive system for independent positioning of up to 8 electrodes (or tetrodes) in a rat (or larger animals). Device is intended to be used in chronic, long term recording applications in freely moving animals. Our design is based on independent stepper motors with lead screws which will offer single steps of ~ μm semi-automatically controlled from the computer. Microdrive system prototype for one electrode was developed and tested. Because of the lack of the systematic test procedures dedicated to such applications, we propose the evaluation of the prototype similar to ISO norm for industrial robots. To this end we designed and implemented magnetic linear and rotary encoders that provided information about electrode displacement and motor shaft movement. On the basis of these measurements we estimated repeatability, accuracy and backlash of the drive. According to the given assumptions and preliminary tests, the device should provide greater accuracy than hand-controlled manipulators available on the market. Automatic positioning will also shorten the course of the experiment and improve the acquisition of signals from multiple neuronal populations.

  14. Noninvasive brain stimulation can induce paradoxical facilitation . Are these neuroenhancements transferable and meaningful to security services?

    Directory of Open Access Journals (Sweden)

    Shirley Fecteau

    2013-08-01

    Full Text Available For ages, we have been looking for ways to enhance our physical and cognitive capacities in order to augment our security. One potential way to achieve this goal may be to externally stimulate the brain. Methods of noninvasive brain stimulation (NIBS, such as repetitive transcranial magnetic stimulation and transcranial electrical stimulation, have been recently developed to modulate brain activity. Both techniques are relatively safe and can transiently modify motor and cognitive functions outlasting the stimulation period. The purpose of this paper is to review data suggesting that NIBS can enhance motor and cognitive performance in healthy volunteers. We frame these findings in the context of whether they may serve security purposes. Specifically, we review studies reporting that NIBS induces paradoxical facilitation in motor (precision, speed, strength, acceleration endurance, and execution of daily motor task and cognitive functions (attention, impulsive behaviour, risk-taking, working memory, planning, and deceptive capacities. Although transferability and meaningfulness of these NIBS-induced paradoxical facilitations into real life situations are not clear yet, NIBS may contribute at improving training of motor and cognitive functions relevant for military, civil and forensic security services. This is an enthusiastic perspective that also calls for fair and open debates on the ethics of using NIBS in healthy individuals to enhance normal functions.

  15. How does transcranial magnetic stimulation modify neuronal activity in the brain? Implications for studies of cognition

    DEFF Research Database (Denmark)

    Siebner, Hartwig R; Hartwigsen, Gesa; Kassuba, Tanja;

    2009-01-01

    cortex is at the time the stimulus is applied: if many neurones are close to firing threshold then the more of them are recruited by the pulse than at rest. Many studies have noted this context-dependent modulation. However, it is often assumed that the excitability of an area has a simple relationship......Transcranial magnetic stimulation (TMS) uses a magnetic field to "carry" a short lasting electrical current pulse into the brain where it stimulates neurones, particularly in superficial regions of cerebral cortex. TMS can interfere with cognitive functions in two ways. A high intensity TMS pulse...... in the human brain. This transient neurodisruption has been termed a "virtual lesion". Smaller intensities of stimulation produce less activity; in such cases, cognitive operations can probably continue but are disrupted because of the added noisy input from the TMS pulse. It is usually argued that...

  16. A case of musical preference for Johnny Cash following deep brain stimulation of the nucleus accumbens

    Directory of Open Access Journals (Sweden)

    Mariska eMantione

    2014-05-01

    Full Text Available Music is among all cultures an important part of the live of most people. Music has psychological benefits and may generate strong emotional and physiological responses. Recently, neuroscientists have discovered that music influences the reward circuit of the nucleus accumbens, even when no explicit reward is present. In this clinical case study, we describe a 60-year old patient who developed a sudden and distinct musical preference for Johnny Cash following deep brain stimulation targeted at the nucleus accumbens for treatment-refractory obsessive-compulsive disorder. This case report substantiates the assumption that the nucleus accumbens is involved in musical preference, based on the observation of direct stimulation of the accumbens with deep brain stimulation. It also shows that accumbens DBS can change musical preference without habituation of its rewarding properties.

  17. Abnormal hemodynamic response to forepaw stimulation in rat brain after cocaine injection

    Science.gov (United States)

    Chen, Wei; Park, Kicheon; Choi, Jeonghun; Pan, Yingtian; Du, Congwu

    2015-03-01

    Simultaneous measurement of hemodynamics is of great importance to evaluate the brain functional changes induced by brain diseases such as drug addiction. Previously, we developed a multimodal-imaging platform (OFI) which combined laser speckle contrast imaging with multi-wavelength imaging to simultaneously characterize the changes in cerebral blood flow (CBF), oxygenated- and deoxygenated- hemoglobin (HbO and HbR) from animal brain. Recently, we upgraded our OFI system that enables detection of hemodynamic changes in response to forepaw electrical stimulation to study potential brain activity changes elicited by cocaine. The improvement includes 1) high sensitivity to detect the cortical response to single forepaw electrical stimulation; 2) high temporal resolution (i.e., 16Hz/channel) to resolve dynamic variations in drug-delivery study; 3) high spatial resolution to separate the stimulation-evoked hemodynamic changes in vascular compartments from those in tissue. The system was validated by imaging the hemodynamic responses to the forepaw-stimulations in the somatosensory cortex of cocaine-treated rats. The stimulations and acquisitions were conducted every 2min over 40min, i.e., from 10min before (baseline) to 30min after cocaine challenge. Our results show that the HbO response decreased first (at ~4min) followed by the decrease of HbR response (at ~6min) after cocaine, and both did not fully recovered for over 30min. Interestingly, while CBF decreased at 4min, it partially recovered at 18min after cocaine administration. The results indicate the heterogeneity of cocaine's effects on vasculature and tissue metabolism, demonstrating the unique capability of optical imaging for brain functional studies.

  18. On the importance of electrode parameters for shaping electric field patterns generated by tDCS

    DEFF Research Database (Denmark)

    B. Saturnino, Guilherme; Antunes, André; Thielscher, Axel

    2015-01-01

    Transcranial direct current stimulation (tDCS) uses electrode pads placed on the head to deliver weak direct current to the brain and modulate neuronal excitability. The effects depend on the intensity and spatial distribution of the electric field. This in turn depends on the geometry and electric...... electrode modeling influences the calculated electric field in the brain. We take into account electrode shape, size, connector position and conductivities of different electrode materials (including saline solutions and electrode gels). These factors are systematically characterized to demonstrate...... their impact on the field distribution in the brain. The goals are to assess the effect of simplified electrode models; and to develop practical rules-of-thumb to achieve a stronger stimulation of the targeted brain regions underneath the electrode pads. We show that for standard rectangular electrode pads...

  19. Low-frequency transcranial magnetic stimulation is beneficial for enhancing synaptic plasticity in the aging brain

    Directory of Open Access Journals (Sweden)

    Zhan-chi Zhang

    2015-01-01

    Full Text Available In the aging brain, cognitive function gradually declines and causes a progressive reduction in the structural and functional plasticity of the hippocampus. Transcranial magnetic stimulation is an emerging and novel neurological and psychiatric tool used to investigate the neurobiology of cognitive function. Recent studies have demonstrated that low-frequency transcranial magnetic stimulation (≤1 Hz ameliorates synaptic plasticity and spatial cognitive deficits in learning-impaired mice. However, the mechanisms by which this treatment improves these deficits during normal aging are still unknown. Therefore, the current study investigated the effects of transcranial magnetic stimulation on the brain-derived neurotrophic factor signal pathway, synaptic protein markers, and spatial memory behavior in the hippocampus of normal aged mice. The study also investigated the downstream regulator, Fyn kinase, and the downstream effectors, synaptophysin and growth-associated protein 43 (both synaptic markers, to determine the possible mechanisms by which transcranial magnetic stimulation regulates cognitive capacity. Transcranial magnetic stimulation with low intensity (110% average resting motor threshold intensity, 1 Hz increased mRNA and protein levels of brain-derived neurotrophic factor, tropomyosin receptor kinase B, and Fyn in the hippocampus of aged mice. The treatment also upregulated the mRNA and protein expression of synaptophysin and growth-associated protein 43 in the hippocampus of these mice. In conclusion, brain-derived neurotrophic factor signaling may play an important role in sustaining and regulating structural synaptic plasticity induced by transcranial magnetic stimulation in the hippocampus of aging mice, and Fyn may be critical during this regulation. These responses may change the structural plasticity of the aging hippocampus, thereby improving cognitive function.

  20. Low-frequency transcranial magnetic stimulation is beneifcial for enhancing synaptic plasticity in the aging brain

    Institute of Scientific and Technical Information of China (English)

    Zhan-chi Zhang; Feng Luan; Chun-yan Xie; Dan-dan Geng; Yan-yong Wang; Jun Ma

    2015-01-01

    In the aging brain, cognitive function gradually declines and causes a progressive reduction in the structural and functional plasticity of the hippocampus. Transcranial magnetic stimulation is an emerging and novel neurological and psychiatric tool used to investigate the neurobiology of cognitive function. Recent studies have demonstrated that low-frequency transcranial magnetic stimulation (≤1 Hz) ameliorates synaptic plasticity and spatial cognitive deifcits in learning-im-paired mice. However, the mechanisms by which this treatment improves these deifcits during normal aging are still unknown. Therefore, the current study investigated the effects of tran-scranial magnetic stimulation on the brain-derived neurotrophic factor signal pathway, synaptic protein markers, and spatial memory behavior in the hippocampus of normal aged mice. The study also investigated the downstream regulator, Fyn kinase, and the downstream effectors, syn-aptophysin and growth-associated protein 43 (both synaptic markers), to determine the possible mechanisms by which transcranial magnetic stimulation regulates cognitive capacity. Transcra-nial magnetic stimulation with low intensity (110%average resting motor threshold intensity, 1 Hz) increased mRNA and protein levels of brain-derived neurotrophic factor, tropomyosin receptor kinase B, and Fyn in the hippocampus of aged mice. The treatment also upregulated the mRNA and protein expression of synaptophysin and growth-associated protein 43 in the hippo-campus of these mice. In conclusion, brain-derived neurotrophic factor signaling may play an important role in sustaining and regulating structural synaptic plasticity induced by transcranial magnetic stimulation in the hippocampus of aging mice, and Fyn may be critical during this reg-ulation. These responses may change the structural plasticity of the aging hippocampus, thereby improving cognitive function.

  1. Brain state-dependent closed-loop modulation of paired associative stimulation controlled by sensorimotor desynchronization

    Directory of Open Access Journals (Sweden)

    Vladislav eRoyter

    2016-05-01

    Full Text Available Background: Pairing peripheral electrical stimulation (ES and transcranial magnetic stimulation (TMS increases corticospinal excitability when applied with a specific temporal pattern. When the two stimulation techniques are applied separately, motor imagery (MI-related oscillatory modulation amplifies both ES-related cortical effects -sensorimotor event-related desynchronization (ERD - and TMS-induced peripheral responses - motor-evoked potentials (MEP. However, the influence of brain self-regulation on the associative pairing of these stimulation techniques is still unclear.Objective: The aim of this pilot study was to investigate the effects of MI-related ERD during associative ES and TMS on subsequent corticospinal excitability. Method: The paired application of functional electrical stimulation (FES of the extensor digitorum communis (EDC muscle and subsequent single-pulse TMS (110% resting motor threshold of the contralateral primary motor cortex was controlled by beta-band (16-22Hz ERD during motor-imagery of finger extension and applied within a brain-machine interface environment in six healthy subjects. Neural correlates were probed by acquiring the stimulus-response curve (SRC of both MEP peak-to-peak amplitude and area under the curve (AUC before and after the intervention. Result: The application of approximately 150 pairs of associative FES and TMS resulted in a significant increase of MEP amplitudes and AUC, indicating that the induced increase of corticospinal excitability was mediated by the recruitment of additional neuronal pools. MEP increases were brain-state dependent and correlated with beta-band ERD, but not with the background EDC muscle activity; this finding was independent of the FES intensity applied.Conclusion: These results could be relevant for developing closed-loop therapeutic approaches such as the application of brain state-dependent, paired associative stimulation in the context of neurorehabilitation.

  2. Alteration of political belief by non- invasive brain stimulation

    Directory of Open Access Journals (Sweden)

    Caroline eChawke

    2016-01-01

    Full Text Available People generally have imperfect introspective access to the mechanisms underlying their political beliefs, yet can confidently communicate the reasoning that goes into their decision making process. An innate desire for certainty and security in ones beliefs may play an important and somewhat automatic role in motivating the maintenance or rejection of partisan support. The aim of the current study was to clarify the role of the DLPFC in the alteration of political beliefs. Recent neuroimaging studies have focused on the association between the DLPFC (a region involved in the regulation of cognitive conflict and error feedback processing and reduced affiliation with opposing political candidates. As such, this study used a method of non- invasive brain simulation (tRNS to enhance activity of the bilateral DLPFC during the incorporation of political campaign information. These findings indicate a crucial role for this region in political belief formation. However, enhanced activation of DLPFC does not necessarily result in the specific rejection of political beliefs. In contrast to the hypothesis the results appear to indicate a significant increase in conservative values regardless of participant’s initial political orientation and the political campaign advertisement they were exposed to.

  3. Towards tailoring non-invasive brain stimulation using real-time fMRI and Bayesian optimization

    OpenAIRE

    Lorenz, Romy; Monti, Ricardo Pio; Hampshire, Adam; Koush, Yury; Anagnostopoulos, Christoforos; Faisal, Aldo A.; Sharp, David; Montana, Giovanni; Leech, Robert; Violante, Ines R

    2016-01-01

    Non-invasive brain stimulation, such as transcranial alternating current stimulation (tACS) provides a powerful tool to directly modulate brain oscillations that mediate complex cognitive processes. While the body of evidence about the effect of tACS on behavioral and cognitive performance is constantly growing, those studies fail to address the importance of subject- specific stimulation protocols. With this study here, we set the foundation to combine tACS with a recently presented framewor...

  4. Inter-subject and Inter-session Variability of Plasticity Induction by Non-invasive Brain Stimulation

    DEFF Research Database (Denmark)

    Ziemann, Ulf; Siebner, Hartwig R

    2015-01-01

    Non-invasive brain stimulation (NIBS) protocols such as regular repetitive transcranial magnetic stimulation (rTMS), theta-burst stimulation (TBS), paired associative stimulation (PAS) and transcranial direct current stimulation (tDCS) can change the excitability of the stimulated neuronal network...... in human cortex well beyond the time of stimulation. These aftereffects have been termed long-term potentiation (LTP)-like and long-term depression (LTD)-like plasticity because indirect evidence supported the notion that synaptic strengthening or weakening similar to LTP/D at the cellular level...

  5. Stability and selectivity of a chronic, multi-contact cuff electrode for sensory stimulation in human amputees

    Science.gov (United States)

    Tan, Daniel W.; Schiefer, Matthew A.; Keith, Michael W.; Anderson, J. Robert; Tyler, Dustin J.

    2015-04-01

    Objective. Stability and selectivity are important when restoring long-term, functional sensory feedback in individuals with limb-loss. Our objective is to demonstrate a chronic, clinical neural stimulation system for providing selective sensory response in two upper-limb amputees. Approach. Multi-contact cuff electrodes were implanted in the median, ulnar, and radial nerves of the upper-limb. Main results. Nerve stimulation produced a selective sensory response on 19 of 20 contacts and 16 of 16 contacts in subjects 1 and 2, respectively. Stimulation elicited multiple, distinct percept areas on the phantom and residual limb. Consistent threshold, impedance, and percept areas have demonstrated that the neural interface is stable for the duration of this on-going, chronic study. Significance. We have achieved selective nerve response from multi-contact cuff electrodes by demonstrating characteristic percept areas and thresholds for each contact. Selective sensory response remains consistent in two upper-limb amputees for 1 and 2 years, the longest multi-contact sensory feedback system to date. Our approach demonstrates selectivity and stability can be achieved through an extraneural interface, which can provide sensory feedback to amputees.

  6. Electrical stimulation of non-classical photon emission from diamond color centers by means of sub-superficial graphitic electrodes

    Science.gov (United States)

    Forneris, Jacopo; Traina, Paolo; Monticone, Daniele Gatto; Amato, Giampiero; Boarino, Luca; Brida, Giorgio; Degiovanni, Ivo P.; Enrico, Emanuele; Moreva, Ekaterina; Grilj, Veljko; Skukan, Natko; Jakšić, Milko; Genovese, Marco; Olivero, Paolo

    2015-10-01

    Focused MeV ion beams with micrometric resolution are suitable tools for the direct writing of conductive graphitic channels buried in an insulating diamond bulk, as already demonstrated for different device applications. In this work we apply this fabrication method to the electrical excitation of color centers in diamond, demonstrating the potential of electrical stimulation in diamond-based single-photon sources. Differently from optically-stimulated light emission from color centers in diamond, electroluminescence (EL) requires a high current flowing in the diamond subgap states between the electrodes. With this purpose, buried graphitic electrode pairs, 10 μm spaced, were fabricated in the bulk of a single-crystal diamond sample using a 6 MeV C microbeam. The electrical characterization of the structure showed a significant current injection above an effective voltage threshold of 150 V, which enabled the stimulation of a stable EL emission. The EL imaging allowed to identify the electroluminescent regions and the residual vacancy distribution associated with the fabrication technique. Measurements evidenced isolated electroluminescent spots where non-classical light emission in the 560-700 nm spectral range was observed. The spectral and auto-correlation features of the EL emission were investigated to qualify the non-classical properties of the color centers.

  7. Midbrain raphe stimulation improves behavioral and anatomical recovery from fluid-percussion brain injury.

    Science.gov (United States)

    Carballosa Gonzalez, Melissa M; Blaya, Meghan O; Alonso, Ofelia F; Bramlett, Helen M; Hentall, Ian D

    2013-01-15

    The midbrain median raphe (MR) and dorsal raphe (DR) nuclei were tested for their capacity to regulate recovery from traumatic brain injury (TBI). An implanted, wireless self-powered stimulator delivered intermittent 8-Hz pulse trains for 7 days to the rat's MR or DR, beginning 4-6 h after a moderate parasagittal (right) fluid-percussion injury. MR stimulation was also examined with a higher frequency (24 Hz) or a delayed start (7 days after injury). Controls had sham injuries, inactive stimulators, or both. The stimulation caused no apparent acute responses or adverse long-term changes. In water-maze trials conducted 5 weeks post-injury, early 8-Hz MR and DR stimulation restored the rate of acquisition of reference memory for a hidden platform of fixed location. Short-term spatial working memory, for a variably located hidden platform, was restored only by early 8-Hz MR stimulation. All stimulation protocols reversed injury-induced asymmetry of spontaneous forelimb reaching movements tested 6 weeks post-injury. Post-mortem histological measurement at 8 weeks post-injury revealed volume losses in parietal-occipital cortex and decussating white matter (corpus callosum plus external capsule), but not hippocampus. The cortical losses were significantly reversed by early 8-Hz MR and DR stimulation, the white matter losses by all forms of MR stimulation. The generally most effective protocol, 8-Hz MR stimulation, was tested 3 days post-injury for its acute effect on forebrain cyclic adenosine monophosphate (cAMP), a key trophic signaling molecule. This procedure reversed injury-induced declines of cAMP levels in both cortex and hippocampus. In conclusion, midbrain raphe nuclei can enduringly enhance recovery from early disseminated TBI, possibly in part through increased signaling by cAMP in efferent targets. A neurosurgical treatment for TBI using interim electrical stimulation in raphe repair centers is suggested. PMID:22963112

  8. Systematic Review of Parameters of Stimulation, Clinical Trial Design Characteristics, and Motor Outcomes in Non-Invasive Brain Stimulation in Stroke

    OpenAIRE

    Simis, Marcel; Adeyemo, Bamidele Oyebamiji; Macea, Debora Duarte; Fregni, Felipe

    2012-01-01

    Introduction/Objectives: Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation are two powerful non-invasive neuromodulatory therapies that have the potential to alter and evaluate the integrity of the corticospinal tract. Moreover, recent evidence has shown that brain stimulation might be beneficial in stroke recovery. Therefore, investigating and investing in innovative therapies that may improve neurorehabilitative stroke recovery are next steps in...

  9. Revealing the brain's adaptability and the transcranial direct current stimulation facilitating effect in inhibitory control by multiscale entropy.

    Science.gov (United States)

    Liang, Wei-Kuang; Lo, Men-Tzung; Yang, Albert C; Peng, Chung-Kang; Cheng, Shih-Kuen; Tseng, Philip; Juan, Chi-Hung

    2014-04-15

    The abilities to inhibit impulses and withdraw certain responses are critical for human's survival in a fast-changing environment. These processes happen fast, in a complex manner, and sometimes are difficult to capture with fMRI or mean electrophysiological brain signal alone. Therefore, an alternative measure that can reveal the efficiency of the neural mechanism across multiple timescales is needed for the investigation of these brain functions. The present study employs a new approach to analyzing electroencephalography (EEG) signal: the multiscale entropy (MSE), which groups data points with different timescales to reveal any occurrence of repeated patterns, in order to theoretically quantify the complexity (indicating adaptability and efficiency) of neural systems during the process of inhibitory control. From this MSE perspective, EEG signals of successful stop trials are more complex and information rich than that of unsuccessful stop trials. We further applied transcranial direct current stimulation (tDCS), with anodal electrode over presupplementary motor area (preSMA), to test the relationship between behavioral modification with the complexity of EEG signals. We found that tDCS can further increase the EEG complexity of the frontal lobe. Furthermore, the MSE pattern was found to be different between high and low performers (divided by their stop-signal reaction time), where the high-performing group had higher complexity in smaller scales and less complexity in larger scales in comparison to the low-performing group. In addition, this between-group MSE difference was found to interact with the anodal tDCS, where the increase of MSE in low performers benefitted more from the anodal tDCS. Together, the current study demonstrates that participants who suffer from poor inhibitory control can efficiently improve their performance with 10min of electrical stimulation, and such cognitive improvement can be effectively traced back to the complexity within the

  10. Closed-Loop Neuroscience and Non-Invasive Brain Stimulation: A Tale of Two Loops.

    Science.gov (United States)

    Zrenner, Christoph; Belardinelli, Paolo; Müller-Dahlhaus, Florian; Ziemann, Ulf

    2016-01-01

    Closed-loop neuroscience is receiving increasing attention with recent technological advances that enable complex feedback loops to be implemented with millisecond resolution on commodity hardware. We summarize emerging conceptual and methodological frameworks that are available to experimenters investigating a "brain in the loop" using non-invasive brain stimulation and briefly review the experimental and therapeutic implications. We take the view that closed-loop neuroscience in fact deals with two conceptually quite different loops: a "brain-state dynamics" loop, used to couple with and modulate the trajectory of neuronal activity patterns, and a "task dynamics" loop, that is the bidirectional motor-sensory interaction between brain and (simulated) environment, and which enables goal-directed behavioral tasks to be incorporated. Both loops need to be considered and combined to realize the full experimental and therapeutic potential of closed-loop neuroscience. PMID:27092055

  11. Closed-Loop Neuroscience and Non-Invasive Brain Stimulation: A Tale of Two Loops

    Science.gov (United States)

    Zrenner, Christoph; Belardinelli, Paolo; Müller-Dahlhaus, Florian; Ziemann, Ulf

    2016-01-01

    Closed-loop neuroscience is receiving increasing attention with recent technological advances that enable complex feedback loops to be implemented with millisecond resolution on commodity hardware. We summarize emerging conceptual and methodological frameworks that are available to experimenters investigating a “brain in the loop” using non-invasive brain stimulation and briefly review the experimental and therapeutic implications. We take the view that closed-loop neuroscience in fact deals with two conceptually quite different loops: a “brain-state dynamics” loop, used to couple with and modulate the trajectory of neuronal activity patterns, and a “task dynamics” loop, that is the bidirectional motor-sensory interaction between brain and (simulated) environment, and which enables goal-directed behavioral tasks to be incorporated. Both loops need to be considered and combined to realize the full experimental and therapeutic potential of closed-loop neuroscience. PMID:27092055

  12. Stimulation of the subthalamic vasodilator area and fastigial nucleus independently protects the brain against focal ischemia.

    Science.gov (United States)

    Glickstein, S B; Ilch, C P; Reis, D J; Golanov, E V

    2001-08-31

    We investigated whether stimulation of the functionally discrete subthalamic region, subthalamic cerebrovasodilator area (SVA), which increases cerebral blood flow (CBF) when excited, would, like stimulation of cerebellar fastigial nucleus (FN), produce central neurogenic neuroprotection. A 1-h electrical stimulation of SVA or FN reduced infarctions triggered by permanent occlusion of middle cerebral artery (MCA) by 48-55% in Sprague-Dawley rats and by 59% in Fisher rats. The salvaging effect of SVA stimulation, similar to FN, was long lasting and reduced the volume of infarctions placed 72 h or 10 days later by 58 and 26%, respectively, in Fisher rats. Bilateral lesioning of FN neurons by the microinjection of ibotenic acid 5 days before SVA stimulation did not affect SVA-evoked neuroprotection. Bilateral lesions of SVA neurons administered 5 days before FN stimulation had no effect on FN-induced neuroprotection but reversed the stimulus-locked increase in CBF accompanying FN stimulation. This study demonstrates that (1) excitation of neurons and/or fibers projecting through the SVA reduces ischemic infarctions as substantially as excitation of FN neurons; (2) the effects are long-lasting and not attributable to increases in cerebral blood flow, changes in blood gases or brain temperature, or rat strain; (3) the neuroprotective effects of SVA and FN stimulation are mutually independent and (4) FN-evoked cerebrovasodilation is mediated by SVA neurons. The SVA and FN are part of a neuronal system in CNS, which is distributed and, when excited, acts to protect the brain from ischemic injury. PMID:11520492

  13. Optimizing a Rodent Model of Parkinson's Disease for Exploring the Effects and Mechanisms of Deep Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Karl Nowak

    2011-01-01

    instrumented rats carrying a backpack stimulator and implanted platinum/iridium electrodes. This model is suitable for (1 elucidating the electrochemical processes at the electrode/tissue interface, (2 analyzing the molecular, cellular and behavioral stimulation effects, (3 testing new target regions for DBS, (4 screening for potential neuroprotective DBS effects, and (5 improving the efficacy and safety of the method. An outlook is given on further developments of experimental DBS, including the use of transgenic animals and the testing of closed-loop systems for the direct on-demand application of electric stimulation.

  14. A novel lead design enables selective deep brain stimulation of neural populations in the subthalamic region

    Science.gov (United States)

    van Dijk, Kees J.; Verhagen, Rens; Chaturvedi, Ashutosh; McIntyre, Cameron C.; Bour, Lo J.; Heida, Ciska; Veltink, Peter H.

    2015-08-01

    Objective. The clinical effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) as a treatment for Parkinson’s disease are sensitive to the location of the DBS lead within the STN. New high density (HD) lead designs have been created which are hypothesized to provide additional degrees of freedom in shaping the stimulating electric field. The objective of this study is to compare the performances of a new HD lead with a conventional cylindrical contact (CC) lead. Approach. A computational model, consisting of a finite element electric field model combined with multi-compartment neuron and axon models representing different neural populations in the subthalamic region, was used to evaluate the two leads. We compared ring-mode and steering-mode stimulation with the HD lead to single contact stimulation with the CC lead. These stimulation modes were tested for the lead: (1) positioned in the centroid of the STN, (2) shifted 1 mm towards the internal capsule (IC), and (3) shifted 2 mm towards the IC. Under these conditions, we quantified the number of STN neurons that were activated without activating IC fibers, which are known to cause side-effects. Main results. The modeling results show that the HD lead is able to mimic the stimulation effect of the CC lead. Additionally, in steering-mode stimulation there was a significant increase of activated STN neurons compared to the CC mode. Significance. From the model simulations we conclude that the HD lead in steering-mode with optimized stimulation parameter selection can stimulate more STN cells. Next, the clinical impact of the increased number of activated STN cells should be tested and balanced across the increased complexity of identifying the optimized stimulation parameter settings for the HD lead.

  15. Midbrain Raphe Stimulation Improves Behavioral and Anatomical Recovery from Fluid-Percussion Brain Injury

    OpenAIRE

    Carballosa Gonzalez, Melissa M.; Blaya, Meghan O.; Alonso, Ofelia F.; Bramlett, Helen M; Hentall, Ian D.

    2013-01-01

    The midbrain median raphe (MR) and dorsal raphe (DR) nuclei were tested for their capacity to regulate recovery from traumatic brain injury (TBI). An implanted, wireless self-powered stimulator delivered intermittent 8-Hz pulse trains for 7 days to the rat's MR or DR, beginning 4–6 h after a moderate parasagittal (right) fluid-percussion injury. MR stimulation was also examined with a higher frequency (24 Hz) or a delayed start (7 days after injury). Controls had sham injuries, inactive stimu...

  16. Resuscitation therapy for traumatic brain injury-induced coma in rats: mechanisms of median nerve electrical stimulation

    OpenAIRE

    Zhen Feng; Ying-jun Zhong; Liang Wang; Tian-qi Wei

    2015-01-01

    In this study, rats were put into traumatic brain injury-induced coma and treated with median nerve electrical stimulation. We explored the wake-promoting effect, and possible mechanisms, of median nerve electrical stimulation. Electrical stimulation upregulated the expression levels of orexin-A and its receptor OX1R in the rat prefrontal cortex. Orexin-A expression gradually increased with increasing stimulation, while OX1R expression reached a peak at 12 hours and then decreased. In additio...

  17. Subject combination and electrode selection in cooperative brain-computer interface based on event related potentials.

    Science.gov (United States)

    Cecotti, Hubert; Rivet, Bertrand

    2014-01-01

    New paradigms are required in Brain-Computer Interface (BCI) systems for the needs and expectations of healthy people. To solve this issue, we explore the emerging field of cooperative BCIs, which involves several users in a single BCI system. Contrary to classical BCIs that are dependent on the unique subject's will, cooperative BCIs are used for problem solving tasks where several people shall be engaged by sharing a common goal. Similarly as combining trials over time improves performance, combining trials across subjects can significantly improve performance compared with when only a single user is involved. Yet, cooperative BCIs may only be used in particular settings, and new paradigms must be proposed to efficiently use this approach. The possible benefits of using several subjects are addressed, and compared with current single-subject BCI paradigms. To show the advantages of a cooperative BCI, we evaluate the performance of combining decisions across subjects with data from an event-related potentials (ERP) based experiment where each subject observed the same sequence of visual stimuli. Furthermore, we show that it is possible to achieve a mean AUC superior to 0.95 with 10 subjects and 3 electrodes on each subject, or with 4 subjects and 6 electrodes on each subject. Several emerging challenges and possible applications are proposed to highlight how cooperative BCIs could be efficiently used with current technologies and leverage BCI applications. PMID:24961765

  18. Subject Combination and Electrode Selection in Cooperative Brain-Computer Interface Based on Event Related Potentials

    Directory of Open Access Journals (Sweden)

    Hubert Cecotti

    2014-04-01

    Full Text Available New paradigms are required in Brain-Computer Interface (BCI systems for the needs and expectations of healthy people. To solve this issue, we explore the emerging field of cooperative BCIs, which involves several users in a single BCI system. Contrary to classical BCIs that are dependent on the unique subject’s will, cooperative BCIs are used for problem solving tasks where several people shall be engaged by sharing a common goal. Similarly as combining trials over time improves performance, combining trials across subjects can significantly improve performance compared with when only a single user is involved. Yet, cooperative BCIs may only be used in particular settings, and new paradigms must be proposed to efficiently use this approach. The possible benefits of using several subjects are addressed, and compared with current single-subject BCI paradigms. To show the advantages of a cooperative BCI, we evaluate the performance of combining decisions across subjects with data from an event-related potentials (ERP based experiment where each subject observed the same sequence of visual stimuli. Furthermore, we show that it is possible to achieve a mean AUC superior to 0.95 with 10 subjects and 3 electrodes on each subject, or with 4 subjects and 6 electrodes on each subject. Several emerging challenges and possible applications are proposed to highlight how cooperative BCIs could be efficiently used with current technologies and leverage BCI applications.

  19. Biofuel Cell Based on Microscale Nanostructured Electrodes with Inductive Coupling to Rat Brain Neurons

    Science.gov (United States)

    Andoralov, Viktor; Falk, Magnus; Suyatin, Dmitry B.; Granmo, Marcus; Sotres, Javier; Ludwig, Roland; Popov, Vladimir O.; Schouenborg, Jens; Blum, Zoltan; Shleev, Sergey

    2013-11-01

    Miniature, self-contained biodevices powered by biofuel cells may enable a new generation of implantable, wireless, minimally invasive neural interfaces for neurophysiological in vivo studies and for clinical applications. Here we report on the fabrication of a direct electron transfer based glucose/oxygen enzymatic fuel cell (EFC) from genuinely three-dimensional (3D) nanostructured microscale gold electrodes, modified with suitable biocatalysts. We show that the process underlying the simple fabrication method of 3D nanostructured electrodes is based on an electrochemically driven transformation of physically deposited gold nanoparticles. We experimentally demonstrate that mediator-, cofactor-, and membrane-less EFCs do operate in cerebrospinal fluid and in the brain of a rat, producing amounts of electrical power sufficient to drive a self-contained biodevice, viz. 7 μW cm-2 in vitro and 2 μW cm-2 in vivo at an operating voltage of 0.4 V. Last but not least, we also demonstrate an inductive coupling between 3D nanobioelectrodes and living neurons.

  20. Biofuel cell based on microscale nanostructured electrodes with inductive coupling to rat brain neurons.

    Science.gov (United States)

    Andoralov, Viktor; Falk, Magnus; Suyatin, Dmitry B; Granmo, Marcus; Sotres, Javier; Ludwig, Roland; Popov, Vladimir O; Schouenborg, Jens; Blum, Zoltan; Shleev, Sergey

    2013-01-01

    Miniature, self-contained biodevices powered by biofuel cells may enable a new generation of implantable, wireless, minimally invasive neural interfaces for neurophysiological in vivo studies and for clinical applications. Here we report on the fabrication of a direct electron transfer based glucose/oxygen enzymatic fuel cell (EFC) from genuinely three-dimensional (3D) nanostructured microscale gold electrodes, modified with suitable biocatalysts. We show that the process underlying the simple fabrication method of 3D nanostructured electrodes is based on an electrochemically driven transformation of physically deposited gold nanoparticles. We experimentally demonstrate that mediator-, cofactor-, and membrane-less EFCs do operate in cerebrospinal fluid and in the brain of a rat, producing amounts of electrical power sufficient to drive a self-contained biodevice, viz. 7 μW cm(-2) in vitro and 2 μW cm(-2) in vivo at an operating voltage of 0.4 V. Last but not least, we also demonstrate an inductive coupling between 3D nanobioelectrodes and living neurons. PMID:24253492

  1. Implementation of active electrodes on a brain-computer interface and its application as P300 speller

    International Nuclear Information System (INIS)

    A brain computer interface has implemented using open hardware called Modular EEG, created by The OpenEEG Project and distributed by the company Olimex Ltd. That hardware is modified to use active electrodes, instead of passive electrodes, for acquiring electroencephalographic signals. The application has been given to the interface has been a speller P300; for which has used the BC12000 open software that has the necessary configuration for the application. P300 speller has used a protocol in each session so that could be standardize the method to different users. Valuing the results with three neuropsychological tests, was within the objectives; however, has not been achieved by the limitation in time of project implementation. A brain computer interface has been used with passive electrodes; implemented in the same way that the BCI with active electrodes; and has worked better than the interface with active electrodes. One of the major advantages that has been observed of passive electrodes on the actives has been the size of the same, because the liabilities are smaller and therefore, easier to place preventing the hair of the user, which increases the noise in the signal. (author)

  2. Biocompatibility of Implantable Electrodes Coated with PVA Films in the Brain of Rats:a Histological Evaluation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qin; LI Tao; LI Chengyan; YE Ming; LU Yi; DUAN Yanwen

    2009-01-01

    The biocompatibility of silicone rubber(SR)based electrodes coating with poly (vinyl alcohol)(PVA)films after implanted in the brain of rats was investigated.Twenty-two Wistar rats were used and implanted with SR electrodes and PVA/PAA films coated electrodes in left and right cerebral cortex respectively.After 4 and 8 weeks,the expression of glial fibrillary acidic protein (GFAP,a specific marker of astrocytes)and cluster of differentiation 68(CD68,a specific marker of macrophages)were evaluated by immunohistochemistry.After 8 weeks,GFAP and CD68 expressions around PVA electrodes were significantly lower than those around SR electrodes in every stratified area(0-50μm,50-100μm,100μm from further up to the electrode-tissue interface).The results show that PVA coating can reduce the expressions of GFAP and CD68,suggesting the PVA coating can improve the biocompatibility of the SR while it is implanted in brain.

  3. Development of implantable optoelectronic module for optical brain tissue stimulation in freely moving mice

    Science.gov (United States)

    Rusakov, Konstantin; Czajkowski, Rafał; Kaźmierczak, Andrzej

    2015-09-01

    The research aims to design and manufacture of wireless optogenetics devices for freely moving animals in cages IntelliCage system. The purpose of the device is to stimulate specific brain regions using light. The constructed device consists of a light source and optical fibre structure responsible for delivering light into the corresponding region of the brain of the animal. The size of the animal (mouse) and the fact that it is freely moving imposes substantial limitations with respect to the size and weight of the optoelectronic device. The present paper describes research on optical fibre structure fabrication, assembling it to the small size (less than 500 × 500 μm2 top surface) LED chip and experimental validation of the optoelectronic stimulator.

  4. Non-invasive brain stimulation: enhancing motor and cognitive functions in healthy old subjects

    Directory of Open Access Journals (Sweden)

    Maximo Zimerman

    2010-12-01

    Full Text Available Healthy aging is accompanied by changes in cognitive and motor functions that result in impairment of activities of daily living. This process involves a number of modifications in the brain and is associated with metabolic, structural and physiological changes; some of these serving as adaptive responses to the functional declines. Up to date there are no universally accepted strategies to ameliorate declining functions in this population. An essential basis to develop such strategies is a better understanding of neuroplastic changes during healthy aging. In this context, non-invasive brain stimulation techniques, such as transcranial direct current or transcranial magnetic stimulation, provide an attractive option to modulate cortical neuronal assemblies, even with subsequent changes in neuroplasticity. Thus, in the present review we discuss the use of these techniques as a tool to study underlying cortical mechanisms during healthy aging and as an interventional strategy to enhance declining functions and learning abilities in aged subjects.

  5. Selective Sensation Based Brain-Computer Interface via Mechanical Vibrotactile Stimulation

    OpenAIRE

    Lin Yao; Jianjun Meng; Dingguo Zhang; Xinjun Sheng; Xiangyang Zhu

    2013-01-01

    In this work, mechanical vibrotactile stimulation was applied to subjects' left and right wrist skins with equal intensity, and a selective sensation perception task was performed to achieve two types of selections similar to motor imagery Brain-Computer Interface. The proposed system was based on event-related desynchronization/synchronization (ERD/ERS), which had a correlation with processing of afferent inflow in human somatosensory system, and attentional effect which modulated the ERD/ER...

  6. Management of Deep Brain Stimulator Battery Failure: Battery Estimators, Charge Density, and Importance of Clinical Symptoms

    OpenAIRE

    Fakhar, Kaihan; Hastings, Erin; Butson, Christopher R.; Foote, Kelly D.; Zeilman, Pam; Okun, Michael S.

    2013-01-01

    Objective We aimed in this investigation to study deep brain stimulation (DBS) battery drain with special attention directed toward patient symptoms prior to and following battery replacement. Background Previously our group developed web-based calculators and smart phone applications to estimate DBS battery life (http://mdc.mbi.ufl.edu/surgery/dbs-battery-estimator). Methods A cohort of 320 patients undergoing DBS battery replacement from 2002–2012 were included in an IRB approved study. Sta...

  7. Modulating affect, cognition and behavior – prospects of deep brain stimulation for treatment resistant psychiatric disorders

    OpenAIRE

    Schlaepfer, Thomas E

    2011-01-01

    Most patients suffering from psychiatric disorders respond to combina-tions of psycho- and psychopharmacotherapy, however there are patients who profit little if anything even after many years of treatment. Since about a decade different modalities of targeted neuromodulation – among them most prominently – Deep Brain Stimulation (DBS) - are being actively researched as putative approaches to very treatment resistant forms of those disorders. Recently, promising pilot data have been re-ported...

  8. Preserving cortico-striatal function: Deep brain stimulation in Huntington's disease

    OpenAIRE

    Nagel, Sean J.; John Thomas Gale; Mayur Pandya

    2015-01-01

    Huntington’s disease (HD) is an incurable neurodegenerative disease characterized by the triad of chorea, cognitive dysfunction and psychiatric disturbances. Since the discovery of the HD gene, the pathogenesis has been outlined, but to date a cure has not been found. Disease modifying therapies are needed desperately to improve function, alleviate suffering, and provide hope for symptomatic patients. Deep brain stimulation (DBS), a proven therapy for managing the symptoms of some neurodegene...

  9. Swallowing function in Parkinson’s patients following Zona Incerta deep brain stimulation

    OpenAIRE

    Sundstedt, Stina; Olofsson, Katarina; van Doorn, Jan; Linder, Jan; Nordh, Erik; Blomstedt, Patric

    2012-01-01

    Objective The purpose of the present study was to examine if there was a negative effect of caudal Zona Incerta deep brain stimulation (cZI DBS) on pharyngeal swallowing function in Parkinson’s patients (PD). There are no former reports on swallowing and cZI DBS. Methods Eight patients (aged 49 to 71 years; median 62) were evaluated pre- and postoperatively, at six and 12 months after DBS surgery. Evaluation tools were Fiberoptic Endoscopic Evaluation of Swallowing examinations and patients’ ...

  10. Theta, alpha and beta burst transcranial magnetic stimulation: brain modulation in tinnitus

    OpenAIRE

    Dirk De Ridder, Elsa van der Loo, Karolien Van der Kelen, Tomas Menovsky, Paul van de Heyning, Aage Moller

    2007-01-01

    Introduction: Some forms of tinnitus are considered to be auditory phantom phenomena related to reorganization and hyperactivity of the auditory central nervous system. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive tool capable of modulating human brain activity, using single pulse or burst stimuli. Burst rTMS has only been performed in the theta range, and has not been used clinically. The authors analyze whether burst TMS at theta (5 Hz), alpha (10 Hz) and beta (20 H...

  11. The Ethics of Deep Brain Stimulation for the Treatment of Anorexia Nervosa

    OpenAIRE

    Maslen, H; Pugh, J.; Savulescu, J.

    2015-01-01

    There is preliminary evidence, from case reports and investigational studies, to suggest that Deep Brain Stimulation (DBS) could be used to treat some patients with Anorexia Nervosa (AN). Although this research is at an early stage, the invasive nature of the intervention and the vulnerability of the potential patients are such that anticipatory ethical analysis is warranted. In this paper, we first show how different treatment mechanisms raise different philosophical and ethical questions. W...

  12. Management of Deep Brain Stimulator Battery Failure: Battery Estimators, Charge Density, and Importance of Clinical Symptoms

    OpenAIRE

    Kaihan Fakhar; Erin Hastings; Butson, Christopher R.; Foote, Kelly D.; Pam Zeilman; Okun, Michael S.

    2013-01-01

    OBJECTIVE: We aimed in this investigation to study deep brain stimulation (DBS) battery drain with special attention directed toward patient symptoms prior to and following battery replacement. BACKGROUND: Previously our group developed web-based calculators and smart phone applications to estimate DBS battery life (http://mdc.mbi.ufl.edu/surgery/dbs-battery-estimator). METHODS: A cohort of 320 patients undergoing DBS battery replacement from 2002-2012 were included in an IRB approved study. ...

  13. Deep Brain Stimulation and Cognitive Decline in Parkinson’s Disease: A Clinical Review

    OpenAIRE

    JoãoMassano

    2012-01-01

    Parkinson’s disease (PD) is a common and often debilitating disorder, with a growing prevalence accompanying global population aging. Current drug therapy is not satisfactory enough for many patients, especially after a few years of symptom progression. This is mainly due to the motor complications that frequently emerge as disease progresses. Deep brain stimulation (DBS) is a useful therapeutic option in carefully selected patients that significantly improves motor symptoms, functional statu...

  14. Non-invasive Brain Stimulation, a Tool to Revert Maladaptive Plasticity in Neuropathic Pain.

    Science.gov (United States)

    Naro, Antonino; Milardi, Demetrio; Russo, Margherita; Terranova, Carmen; Rizzo, Vincenzo; Cacciola, Alberto; Marino, Silvia; Calabro, Rocco S; Quartarone, Angelo

    2016-01-01

    Neuromodulatory effects of non-invasive brain stimulation (NIBS) have been extensively studied in chronic pain. A hypothetic mechanism of action would be to prevent or revert the ongoing maladaptive plasticity within the pain matrix. In this review, the authors discuss the mechanisms underlying the development of maladaptive plasticity in patients with chronic pain and the putative mechanisms of NIBS in modulating synaptic plasticity in neuropathic pain conditions. PMID:27512368

  15. Deep Brain Stimulation in Huntington’s Disease—Preliminary Evidence on Pathophysiology, Efficacy and Safety

    Directory of Open Access Journals (Sweden)

    Lars Wojtecki

    2016-08-01

    Full Text Available Huntington’s disease (HD is one of the most disabling degenerative movement disorders, as it not only affects the motor system but also leads to cognitive disabilities and psychiatric symptoms. Deep brain stimulation (DBS of the pallidum is a promising symptomatic treatment targeting the core motor symptom: chorea. This article gives an overview of preliminary evidence on pathophysiology, safety and efficacy of DBS in HD.

  16. Mechanisms of deep brain stimulation for obsessive compulsive disorder: effects upon cells and circuits

    OpenAIRE

    Bourne, Sarah K.; Eckhardt, Christine A.; Sheth, Sameer A.; Eskandar, Emad N.

    2012-01-01

    Deep brain stimulation (DBS) has emerged as a safe, effective, and reversible treatment for a number of movement disorders. This has prompted investigation of its use for other applications including psychiatric disorders. In recent years, DBS has been introduced for the treatment of obsessive compulsive disorder (OCD), which is characterized by recurrent unwanted thoughts or ideas (obsessions) and repetitive behaviors or mental acts performed in order to relieve these obsessions (compulsions...

  17. Mechanisms of deep brain stimulation for obsessive compulsive disorder: effects upon cells and circuits

    OpenAIRE

    Sarah Kathleen Bourne; Christine Ann Eckhardt; Sheth, Sameer A.; Eskandar, Emad N.

    2012-01-01

    Deep brain stimulation (DBS) has emerged as a safe, effective, and reversible treatment for a number of movement disorders. This has prompted investigation of its use for other applications including psychiatric disorders. In recent years, DBS has been introduced for the treatment of obsessive-compulsive disorder (OCD), which is characterized by recurrent unwanted thoughts or ideas (obsessions) and repetitive behaviors or mental acts performed in order to relieve these obsessions (compulsions...

  18. Deep brain stimulation (DBS) at the interface of neurology and psychiatry

    OpenAIRE

    Williams, Nolan R.; Okun, Michael S.

    2013-01-01

    Deep brain stimulation (DBS) is an emerging interventional therapy for well-screened patients with specific treatment-resistant neuropsychiatric diseases. Some neuropsychiatric conditions, such as Parkinson disease, have available and reasonable guideline and efficacy data, while other conditions, such as major depressive disorder and Tourette syndrome, have more limited, but promising results. This review summarizes both the efficacy and the neuroanatomical targets for DBS in four common neu...

  19. Deep Brain Stimulation and Dantrolene for Secondary Dystonia in X-Linked Adrenoleukodystrophy

    OpenAIRE

    Van Karnebeek, Clara; Horvath, Gabriella; Murphy, Tyler; Purtzki, Jacqueline; Bowden, Kristin; Sirrs, Sandra; Honey, Christopher R.; Stockler, Sylvia

    2014-01-01

    Deep brain stimulation (DBS) has been used to treat secondary dystonias caused by inborn errors of metabolism with varying degrees of effectiveness. Here we report for the first time the application of DBS as treatment for secondary dystonia in a 22-year-old male with X-linked adrenoleukodystrophy (X-ALD). The disease manifested at age 6 with ADHD, tics, and dystonic gait, and deteriorated to loss of ambulation by age 11, and speech difficulties, seizures, and characteristic adrenal insuffici...

  20. Restoration of grasp following paralysis through brain-controlled stimulation of muscles

    OpenAIRE

    Ethier, C.; Oby, E.R.; Bauman, M.J.; Miller, L.E.

    2012-01-01

    Patients with spinal cord injury lack the connections between brain and spinal cord circuits essential for voluntary movement. Clinical systems that achieve muscle contraction through functional electrical stimulation (FES) have proven to be effective in allowing patients with tetraplegia to regain control of hand movement and to achieve a greater measure of independence in activities of daily living 1,2 . In typical systems, the patient uses residual proximal limb movements to trigger pre-pr...

  1. Electrical stimulation alleviates depressive-like behaviors of rats: investigation of brain targets and potential mechanisms.

    Science.gov (United States)

    Lim, L W; Prickaerts, J; Huguet, G; Kadar, E; Hartung, H; Sharp, T; Temel, Y

    2015-01-01

    Deep brain stimulation (DBS) is a promising therapy for patients with refractory depression. However, key questions remain with regard to which brain target(s) should be used for stimulation, and which mechanisms underlie the therapeutic effects. Here, we investigated the effect of DBS, with low- and high-frequency stimulation (LFS, HFS), in different brain regions (ventromedial prefrontal cortex, vmPFC; cingulate cortex, Cg; nucleus accumbens (NAc) core or shell; lateral habenula, LHb; and ventral tegmental area) on a variety of depressive-like behaviors using rat models. In the naive animal study, we found that HFS of the Cg, vmPFC, NAc core and LHb reduced anxiety levels and increased motivation for food. In the chronic unpredictable stress model, there was a robust depressive-like behavioral phenotype. Moreover, vmPFC HFS, in a comparison of all stimulated targets, produced the most profound antidepressant effects with enhanced hedonia, reduced anxiety and decreased forced-swim immobility. In the following set of electrophysiological and histochemical experiments designed to unravel some of the underlying mechanisms, we found that vmPFC HFS evoked a specific modulation of the serotonergic neurons in the dorsal raphe nucleus (DRN), which have long been linked to mood. Finally, using a neuronal mapping approach by means of c-Fos expression, we found that vmPFC HFS modulated a brain circuit linked to the DRN and known to be involved in affect. In conclusion, HFS of the vmPFC produced the most potent antidepressant effects in naive rats and rats subjected to stress by mechanisms also including the DRN. PMID:25826110

  2. Globus Pallidus Interna Deep Brain Stimulation in a Patient with Medically Intractable Meige Syndrome

    Directory of Open Access Journals (Sweden)

    Dae-Woong Bae

    2014-10-01

    Full Text Available Medical therapies in patients with Meige syndrome, including botulinum toxin injection, have been limited because of incomplete response or adverse side effects. We evaluated a patient with Meige syndrome who was successfully treated with deep brain stimulation (DBS in the globus pallidus interna (GPi. This case report and other previous reports suggest that bilateral GPi DBS may be an effective treatment for medically refractory Meige syndrome, without significant adverse effects.

  3. Radio electric asymmetric brain stimulation in the treatment of behavioral and psychiatric symptoms in Alzheimer disease

    OpenAIRE

    Mannu P; Rinaldi S; Fontani V; Castagna A

    2011-01-01

    Piero Mannu1, Salvatore Rinaldi1,2, Vania Fontani1, Alessandro Castagna11Rinaldi Fontani Institute, Department of Neuro Psycho Physio Pathology, Florence, Italy; 2Medical School of Occupational Medicine, University of Florence, Florence, ItalyPurpose: Behavioral and psychiatric symptoms of dementia (BPSD) are common in Alzheimer's disease (AD) and disrupt the effective management of AD patients. The present study explores the use of radio electric asymmetric brain stimulation (REAC) i...

  4. To what extent can dry and water-based EEG electrodes replace conductive gel ones?: A Steady State Visual Evoked Potential Brain-Computer Interface Case Study

    OpenAIRE

    Mihajlovic, V.; Garcia Molina, G.; Peuscher, J

    2011-01-01

    Recent technological advances in the field of skin electrodes and on-body sensors indicate a possibility of having an alternative to the traditionally used conductive gel electrodes for measuring electrical signals of the brain (electroencephalogram, EEG). This paper evaluates whether water-based and dry contact electrode solutions can replace the gel ones. The quality of the obtained signal by three headsets, each using 8 electrodes of a different type, is estimated onthe steady state visual...

  5. Effects of scanner acoustic noise on intrinsic brain activity during auditory stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Yakunina, Natalia [Kangwon National University, Institute of Medical Science, School of Medicine, Chuncheon (Korea, Republic of); Kangwon National University Hospital, Neuroscience Research Institute, Chuncheon (Korea, Republic of); Kang, Eun Kyoung [Kangwon National University Hospital, Department of Rehabilitation Medicine, Chuncheon (Korea, Republic of); Kim, Tae Su [Kangwon National University Hospital, Department of Otolaryngology, Chuncheon (Korea, Republic of); Kangwon National University, School of Medicine, Department of Otolaryngology, Chuncheon (Korea, Republic of); Min, Ji-Hoon [University of Michigan, Department of Biopsychology, Cognition, and Neuroscience, Ann Arbor, MI (United States); Kim, Sam Soo [Kangwon National University Hospital, Neuroscience Research Institute, Chuncheon (Korea, Republic of); Kangwon National University, School of Medicine, Department of Radiology, Chuncheon (Korea, Republic of); Nam, Eui-Cheol [Kangwon National University Hospital, Neuroscience Research Institute, Chuncheon (Korea, Republic of); Kangwon National University, School of Medicine, Department of Otolaryngology, Chuncheon (Korea, Republic of)

    2015-10-15

    Although the effects of scanner background noise (SBN) during functional magnetic resonance imaging (fMRI) have been extensively investigated for the brain regions involved in auditory processing, its impact on other types of intrinsic brain activity has largely been neglected. The present study evaluated the influence of SBN on a number of intrinsic connectivity networks (ICNs) during auditory stimulation by comparing the results obtained using sparse temporal acquisition (STA) with those using continuous acquisition (CA). Fourteen healthy subjects were presented with classical music pieces in a block paradigm during two sessions of STA and CA. A volume-matched CA dataset (CAm) was generated by subsampling the CA dataset to temporally match it with the STA data. Independent component analysis was performed on the concatenated STA-CAm datasets, and voxel data, time courses, power spectra, and functional connectivity were compared. The ICA revealed 19 ICNs; the auditory, default mode, salience, and frontoparietal networks showed greater activity in the STA. The spectral peaks in 17 networks corresponded to the stimulation cycles in the STA, while only five networks displayed this correspondence in the CA. The dorsal default mode and salience networks exhibited stronger correlations with the stimulus waveform in the STA. SBN appeared to influence not only the areas of auditory response but also the majority of other ICNs, including attention and sensory networks. Therefore, SBN should be regarded as a serious nuisance factor during fMRI studies investigating intrinsic brain activity under external stimulation or task loads. (orig.)

  6. Effects of scanner acoustic noise on intrinsic brain activity during auditory stimulation

    International Nuclear Information System (INIS)

    Although the effects of scanner background noise (SBN) during functional magnetic resonance imaging (fMRI) have been extensively investigated for the brain regions involved in auditory processing, its impact on other types of intrinsic brain activity has largely been neglected. The present study evaluated the influence of SBN on a number of intrinsic connectivity networks (ICNs) during auditory stimulation by comparing the results obtained using sparse temporal acquisition (STA) with those using continuous acquisition (CA). Fourteen healthy subjects were presented with classical music pieces in a block paradigm during two sessions of STA and CA. A volume-matched CA dataset (CAm) was generated by subsampling the CA dataset to temporally match it with the STA data. Independent component analysis was performed on the concatenated STA-CAm datasets, and voxel data, time courses, power spectra, and functional connectivity were compared. The ICA revealed 19 ICNs; the auditory, default mode, salience, and frontoparietal networks showed greater activity in the STA. The spectral peaks in 17 networks corresponded to the stimulation cycles in the STA, while only five networks displayed this correspondence in the CA. The dorsal default mode and salience networks exhibited stronger correlations with the stimulus waveform in the STA. SBN appeared to influence not only the areas of auditory response but also the majority of other ICNs, including attention and sensory networks. Therefore, SBN should be regarded as a serious nuisance factor during fMRI studies investigating intrinsic brain activity under external stimulation or task loads. (orig.)

  7. Non-invasive brain stimulation: an interventional tool for enhancing behavioral training after stroke

    Directory of Open Access Journals (Sweden)

    Maximilian Jonas Wessel

    2015-05-01

    Full Text Available Stroke is the leading cause of disability among adults. Motor deficit is the most common impairment after stroke. Especially, deficits in fine motor skills impair numerous activities of daily life. Re-acquisition of motor skills resulting in improved or more accurate motor performance is paramount to regain function, and is the basis of behavioral motor therapy after stroke. Within the past years, there has been a rapid technological and methodological development in neuroimaging leading to a significant progress in the understanding of the neural substrates that underlie motor skill acquisition and functional recovery in stroke patients. Based on this and the development of novel non-invasive brain stimulation techniques, new adjuvant interventional approaches that augment the response to behavioral training have been proposed. Transcranial direct current (tDCS, transcranial magnetic (TMS and paired associative (PAS stimulation are noninvasive brain stimulation techniques that can modulate cortical excitability, neuronal plasticity and interact with learning and memory in both healthy individuals and stroke patients. These techniques can enhance the effect of practice and facilitate the retention of tasks that mimic daily life activities. The purpose of the present review is to provide a comprehensive overview of neuroplastic phenomena in the motor system during learning of a motor skill, recovery after brain injury, and of interventional strategies to enhance the beneficial effects of customarily used neurorehabilitation after stroke.

  8. Brain-Controlled Neuromuscular Stimulation to Drive Neural Plasticity and Functional Recovery

    Science.gov (United States)

    Ethier, C.; Gallego, J.A.; Miller, L.E.

    2015-01-01

    There is mounting evidence that appropriately timed neuromuscular stimulation can induce neural plasticity and generate functional recovery from motor disorders. This review addresses the idea that coordinating stimulation with a patient’s voluntary effort might further enhance neurorehabilitation. Studies in cell cultures and behaving animals have delineated the rules underlying neural plasticity when single neurons are used as triggers. However, the rules governing more complex stimuli and larger networks are less well understood. We argue that functional recovery might be optimized if stimulation were modulated by a brain machine interface, to matched the details of the patient’s voluntary intent. The potential of this novel approach highlights the need for a better understanding of the complex rules underlying this form of plasticity. PMID:25827275

  9. The challenge of crafting policy for do-it-yourself brain stimulation.

    Science.gov (United States)

    Fitz, Nicholas S; Reiner, Peter B

    2015-05-01

    Transcranial direct current stimulation (tDCS), a simple means of brain stimulation, possesses a trifecta of appealing features: it is relatively safe, relatively inexpensive and relatively effective. It is also relatively easy to obtain a device and the do-it-yourself (DIY) community has become galvanised by reports that tDCS can be used as an all-purpose cognitive enhancer. We provide practical recommendations designed to guide balanced discourse, propagate norms of safe use and stimulate dialogue between the DIY community and regulatory authorities. We call on all stakeholders-regulators, scientists and the DIY community-to share in crafting policy proposals that ensure public safety while supporting DIY innovation. PMID:23733050

  10. Virtual electrodes in cardiac tissue: a common mechanism for anodal and cathodal stimulation.

    OpenAIRE

    Wikswo, J.P.; Lin, S F; Abbas, R A

    1995-01-01

    Traditional cable analyses cannot explain complex patterns of excitation in cardiac tissue with unipolar, extracellular anodal, or cathodal stimuli. Epifluorescence imaging of the transmembrane potential during and after stimulation of both refractory and excitable tissue shows distinctive regions of simultaneous depolarization and hyperpolarization during stimulation that act as virtual cathodes and anodes. The results confirm bidomain model predictions that the onset (make) of a stimulus in...

  11. Numerical analysis and design of single-source multicoil TMS for deep and focused brain stimulation.

    Science.gov (United States)

    Gomez, Luis; Cajko, Frantishek; Hernandez-Garcia, Luis; Grbic, Anthony; Michielssen, Eric

    2013-10-01

    Transcranial magnetic stimulation (TMS) is a tool for noninvasive stimulation of neuronal tissue used for research in cognitive neuroscience and to treat neurological disorders. Many TMS applications call for large electric fields to be sharply focused on regions that often lie deep inside the brain. Unfortunately, the fields generated by present-day TMS coils diffuse and decay rapidly as they penetrate into the head. As a result, they tend to stimulate relatively large regions of tissue near the brain surface. Earlier studies suggested that a focused TMS excitation can be attained using multiple nonuniformly fed coils in a multichannel array. We propose a systematic, genetic algorithm-based technique for synthesizing multichannel arrays that minimize the volume of the excited region required to achieve a prescribed penetration depth and maintain realistic values for the input driving currents. Because multichannel arrays are costly to build, we also propose a method to convert the multichannel arrays into single-channel ones while minimally materially deteriorating performance. Numerical results show that the new multi- and single-channel arrays stimulate tissue 2.4 cm into the head while exciting 3.0 and 2.6 times less volume than conventional Figure-8 coils, respectively. PMID:23708768

  12. Treatment of neurological and psychiatric disorders with deep brain stimulation; raising hopes and future challenges.

    Science.gov (United States)

    Sharifi, Mohammad Sharif

    2013-01-01

    The technology of Neural Stimulation in recent years has become the focus of the research and treatment, although it has been around for many years. The potential use of stimulating the brain and nerves ranges from the spinal cord stimulation to the implantations of cochlear and bionic eyes with a large discrepancy between the clinical readiness for these various uses. Electrical high-frequency Deep Brain Stimulation (DBS) was developed as an alternative option to treat a few neurological disorders. However, with advancing in surgical procedures, technologies and safeties, the applications of DBS are expanding not only for therapeutic purposes but also for research. Although the exact mechanisms of action/s are not fully understood, the outcome of the ongoing research and clinical trials are promising. DBS has been used to treat the essential tremor since 1997, Parkinson's disease (PD) since 2002 and dystonia since 2003. It has also been used to treat various disorders, including major depression. The therapeutic effect of DBS in PD is well established but for other diseases such as epilepsy the outcomes are unclear and ambiguous. This article is a succinct review of the literature, focusing on PD, epilepsy and Obsessive Compulsive Disorder (OCD). PMID:25337356

  13. Induction of neuroplasticity and recovery in post-stroke aphasia by non-invasive brain stimulation

    Directory of Open Access Journals (Sweden)

    Priyanka Shah

    2013-12-01

    Full Text Available Stroke victims tend to prioritize speaking, writing and walking as the three most important rehabilitation goals. Of note is that two of these goals involve communication. This underscores the significance of developing successful approaches to aphasia treatment for the several hundred thousand new aphasia patients each year and over 1 million stroke survivors with chronic aphasia in the U.S. alone. After several years of growth as a research tool, noninvasive brain stimulation (NBS is gradually entering the arena of clinical aphasiology. In this review, we first examine the current state of knowledge of post-stroke language recovery including the contributions from the dominant and non-dominant hemispheres. Next, we briefly discuss the methods and the physiologic basis of the use of inhibitory and excitatory repetitive transcranial magnetic stimulation (rTMS and transcranial direct current stimulation (tDCS as research tools in patients who experience post-stroke aphasia. Finally, we provide a critical review of the most influential evidence behind the potential use of these two brain stimulation methods as clinical rehabilitative tools.

  14. Predicting the Probability of Abnormal Stimulated Growth Hormone Response in Children After Radiotherapy for Brain Tumors

    International Nuclear Information System (INIS)

    Purpose: To develop a mathematical model utilizing more readily available measures than stimulation tests that identifies brain tumor survivors with high likelihood of abnormal growth hormone secretion after radiotherapy (RT), to avoid late recognition and a consequent delay in growth hormone replacement therapy. Methods and Materials: We analyzed 191 prospectively collected post-RT evaluations of peak growth hormone level (arginine tolerance/levodopa stimulation test), serum insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, height, weight, growth velocity, and body mass index in 106 children and adolescents treated for ependymoma (n = 72), low-grade glioma (n = 28) or craniopharyngioma (n = 6), who had normal growth hormone levels before RT. Normal level in this study was defined as the peak growth hormone response to the stimulation test ≥7 ng/mL. Results: Independent predictor variables identified by multivariate logistic regression with high statistical significance (p < 0.0001) included IGF-1 z score, weight z score, and hypothalamic dose. The developed predictive model demonstrated a strong discriminatory power with an area under the receiver operating characteristic curve of 0.883. At a potential cutoff point of probability of 0.3 the sensitivity was 80% and specificity 78%. Conclusions: Without unpleasant and expensive frequent stimulation tests, our model provides a quantitative approach to closely follow the growth hormone secretory capacity of brain tumor survivors. It allows identification of high-risk children for subsequent confirmatory tests and in-depth workup for diagnosis of growth hormone deficiency.

  15. Predicting the Probability of Abnormal Stimulated Growth Hormone Response in Children After Radiotherapy for Brain Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Hua Chiaho, E-mail: Chia-Ho.Hua@stjude.org [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Wu Shengjie [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Chemaitilly, Wassim [Division of Endocrinology, Department of Pediatric Medicine, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Lukose, Renin C.; Merchant, Thomas E. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2012-11-15

    Purpose: To develop a mathematical model utilizing more readily available measures than stimulation tests that identifies brain tumor survivors with high likelihood of abnormal growth hormone secretion after radiotherapy (RT), to avoid late recognition and a consequent delay in growth hormone replacement therapy. Methods and Materials: We analyzed 191 prospectively collected post-RT evaluations of peak growth hormone level (arginine tolerance/levodopa stimulation test), serum insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, height, weight, growth velocity, and body mass index in 106 children and adolescents treated for ependymoma (n = 72), low-grade glioma (n = 28) or craniopharyngioma (n = 6), who had normal growth hormone levels before RT. Normal level in this study was defined as the peak growth hormone response to the stimulation test {>=}7 ng/mL. Results: Independent predictor variables identified by multivariate logistic regression with high statistical significance (p < 0.0001) included IGF-1 z score, weight z score, and hypothalamic dose. The developed predictive model demonstrated a strong discriminatory power with an area under the receiver operating characteristic curve of 0.883. At a potential cutoff point of probability of 0.3 the sensitivity was 80% and specificity 78%. Conclusions: Without unpleasant and expensive frequent stimulation tests, our model provides a quantitative approach to closely follow the growth hormone secretory capacity of brain tumor survivors. It allows identification of high-risk children for subsequent confirmatory tests and in-depth workup for diagnosis of growth hormone deficiency.

  16. Restoring cognitive functions using non-invasive brain stimulation techniques in patients with cerebellar disorders

    Directory of Open Access Journals (Sweden)

    RChrisMiall

    2014-04-01

    Full Text Available Numerous studies have highlighted the possibility of modulating the excitability of cerebro-cerebellar circuits bi-directionally using transcranial electrical brain stimulation, in a manner akin to that observed using magnetic stimulation protocols. It has been proposed that cerebellar stimulation activates Purkinje cells in the cerebellar cortex, leading to inhibition of the dentate nucleus, which exerts a tonic facilitatory drive onto motor and cognitive regions of cortex through a synaptic relay in the ventral-lateral thalamus. Some cerebellar deficits present with cognitive impairments if damage to non-motor regions of the cerebellum disrupts the coupling with cerebral cortical areas for thinking and reasoning. Indeed, white matter changes in the dentato-rubral tract correlate with cognitive assessments in patients with Friedreich ataxia, suggesting that this pathway is one component of the anatomical substrate supporting a cerebellar contribution to cognition. An understanding of the physiology of the cerebro-cerebellar pathway previously helped us to constrain our interpretation of results from two recent studies in which we showed cognitive enhancements in healthy participants during tests of arithmetic after electrical stimulation of the cerebellum, but only when task demands were high. Others studies have also shown how excitation of the prefrontal cortex can enhance performance in a variety of working memory tasks. Thus, future efforts might be guided towards neuro-enhancement in certain patient populations, using what is commonly termed 'non-invasive brain stimulation' as a cognitive rehabilitation tool to modulate cerebro-cerebellar circuits, or for stimulation over the cerebral cortex to compensate for decreased cerebellar drive to this region. This article will address these possibilities with a review of the relevant literature covering ataxias and cerebellar cognitive affective disorders, which are characterized by thalamo

  17. Seizure Suppression Efficacy of Closed-Loop Versus Open-Loop Deep Brain Stimulation in a Rodent Model of Epilepsy.

    Science.gov (United States)

    Salam, M Tariqus; Perez Velazquez, Jose Luis; Genov, Roman

    2016-06-01

    We assess and compare the effects of both closed-loop and open-loop neurostimulation of the rat hippocampus by means of a custom low-power programmable therapeutic neurostimulation device on the suppression of spontaneous seizures in a rodent model of epilepsy. Chronic seizures were induced by intraperitoneal kainic acid injection. Two bipolar electrodes were implanted into the CA1 regions of both hippocampi. The electrodes were connected to the custom-built programmable therapeutic neurostimulation device that can trigger an electrical stimulation either in a periodic manner or upon detection of the intracerebral electroencephalographic (icEEE) seizure onset. This device includes a microchip consisting of a 256-channel icEEG recording system and a 64-channel stimulator, and a programmable seizure detector implemented in a field-programmable gate array (FPGA). The neurostimulator was used to evaluate seizure suppression efficacy in ten epileptic rats for a total of 240 subject-days (5760 subject-hours). For this purpose, all rats were randomly divided into two groups: the no-stimulation group and the stimulation group. The no-stimulation group did not receive stimulation. The stimulation group received, first, closed-loop stimulation and, next, open-loop stimulation. The no-stimulation and stimulation groups had a similar seizure frequency baseline, averaging five seizures per day. Closed-loop stimulation reduced seizure frequency by 90% and open-loop stimulation reduced seizure frequency by 17%, both in the stimulation group as compared to the no-stimulation group. PMID:26571534

  18. Image-guided preoperative prediction of pyramidal tract side effect in deep brain stimulation: proof of concept and application to the pyramidal tract side effect induced by pallidal stimulation.

    Science.gov (United States)

    Baumgarten, Clement; Zhao, Yulong; Sauleau, Paul; Malrain, Cecile; Jannin, Pierre; Haegelen, Claire

    2016-04-01

    Deep brain stimulation of the medial globus pallidus (GPm) is a surgical procedure for treating patients suffering from Parkinson's disease. Its therapeutic effect may be limited by the presence of pyramidal tract side effect (PTSE). PTSE is a contraction time-locked to the stimulation when the current spreading reaches the motor fibers of the pyramidal tract within the internal capsule. The objective of the study was to propose a preoperative predictive model of PTSE. A machine learning-based method called PyMAN (PTSE model based on artificial neural network) accounting for the current used in stimulation, the three-dimensional electrode coordinates and the angle of the trajectory, was designed to predict the occurrence of PTSE. Ten patients implanted in the GPm have been tested by a clinician to create a labeled dataset of the stimulation parameters that trigger PTSE. The kappa index value between the data predicted by PyMAN and the labeled data was 0.78. Further evaluation studies are desirable to confirm whether PyMAN could be a reliable tool for assisting the surgeon to prevent PTSE during the preoperative planning. PMID:27413769

  19. Deep brain stimulation of the subthalamic nucleus: effectiveness in advanced Parkinson's disease patients previously reliant on apomorphine

    OpenAIRE

    Varma, T; Fox, S.; Eldridge, P; Littlechild, P; Byrne, P.; Forster, A; Marshall, A.; Cameron, H.; McIver, K; Fletcher, N; Steiger, M.

    2003-01-01

    Objectives: To assess the efficacy of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with advanced Parkinson's disease previously reliant on apomorphine as their main antiparkinsonian medication.

  20. Probabilistic Modeling of Selective Stimulation of the Human Sciatic Nerve with a Flat Interface Nerve Electrode

    OpenAIRE

    Schiefer, Matthew A.; Tyler, Dustin J.; Triolo, Ronald J.

    2012-01-01

    Ankle control is critical to both standing balance and efficient walking. This hypothesis presented in this paper is that a Flat Interface Nerve Electrode (FINE) placed around the sciatic nerve with a fixed number of contacts at predetermined locations and without a priori knowledge of the nerve’s underlying neuroanatomy can selectively control each ankle motion. Models of the human sciatic nerve surrounded by a FINE of varying size were created and used to calculate the probability of select...

  1. Acute Modulation of Brain Connectivity in Parkinson Disease after Automatic Mechanical Peripheral Stimulation: A Pilot Study.

    Directory of Open Access Journals (Sweden)

    Carlo Cosimo Quattrocchi

    Full Text Available The present study shows the results of a double-blind sham-controlled pilot trial to test whether measurable stimulus-specific functional connectivity changes exist after Automatic Mechanical Peripheral Stimulation (AMPS in patients with idiopathic Parkinson Disease.Eleven patients (6 women and 5 men with idiopathic Parkinson Disease underwent brain fMRI immediately before and after sham or effective AMPS. Resting state Functional Connectivity (RSFC was assessed using the seed-ROI based analysis. Seed ROIs were positioned on basal ganglia, on primary sensory-motor cortices, on the supplementary motor areas and on the cerebellum. Individual differences for pre- and post-effective AMPS and pre- and post-sham condition were obtained and first entered in respective one-sample t-test analyses, to evaluate the mean effect of condition.Effective AMPS, but not sham stimulation, induced increase of RSFC of the sensory motor cortex, nucleus striatum and cerebellum. Secondly, individual differences for both conditions were entered into paired group t-test analysis to rule out sub-threshold effects of sham stimulation, which showed stronger connectivity of the striatum nucleus with the right lateral occipital cortex and the cuneal cortex (max Z score 3.12 and with the right anterior temporal lobe (max Z score 3.42 and of the cerebellum with the right lateral occipital cortex and the right cerebellar cortex (max Z score 3.79.Our results suggest that effective AMPS acutely increases RSFC of brain regions involved in visuo-spatial and sensory-motor integration.This study provides Class II evidence that automatic mechanical peripheral stimulation is effective in modulating brain functional connectivity of patients with Parkinson Disease at rest.Clinical Trials.gov NCT01815281.

  2. Subthalamic nucleus deep brain stimulation does not improve visuo-motor impairment in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Simon D Israeli-Korn

    Full Text Available OBJECTIVE: To evaluate how bilateral subthalamic nucleus deep brain stimulation (STN-DBS affects visuo-motor coordination (VMC in patients with Parkinson's disease (PD. BACKGROUND: VMC involves multi-sensory integration, motor planning, executive function and attention. VMC deficits are well-described in PD. STN-DBS conveys marked motor benefit in PD, but pyscho-cognitive complications are recognized and the effect on VMC is not known. METHODS: Thirteen PD patients with bilateral STN-DBS underwent neurological, cognitive, and mood assessment before VMC testing with optimal DBS stimulation parameters ('on-stimulation' and then, on the same day without any medication changes, after DBS silencing and establishing motor function deterioration ('off-stimulation'. Twelve age-matched healthy controls performed 2 successive VMC testing sessions, with a break of similar duration to that of the PD group. The computer cursor was controlled with a dome-shaped 'mouse' hidden from view that minimized tremor effects. Movement duration, hand velocity, tracking continuity, directional control variables, and feedback utilization variables were measured. MANOVA was performed on (1 clinically measured motor function, (2 VMC performance and (3 mood and attention, looking for main and interaction effects of: (1 group (controls/PD, (2 test-order (controls: first/second, PD: on-stimulation/off-stimulation, (3 path (sine/square/circle and (4 hand (dominant/non-dominant. RESULTS: Unified PD Rating Scale (UPDRS Part III worsened off-stimulation versus on-stimulation (mean: 42.3 versus 21.6, p = 0.02, as did finger tapping (p = 0.02, posture-gait (p = 0.01, upper limb function (p<0.001 and backwards digit span (p = 0.02. Stimulation state did not affect mood. PD patients performed worse in non-velocity related VMC variables than controls (F(5,18 = 8.5, p<0.001. In the control group there were significant main effects of hand (dominant/non-dominant, path

  3. EDITORIAL: Deep brain stimulation, deontology and duty: the moral obligation of non-abandonment at the neural interface Deep brain stimulation, deontology and duty: the moral obligation of non-abandonment at the neural interface

    Science.gov (United States)

    Fins, Joseph J.; MD; FACP

    2009-10-01

    At the height of the psychosurgery debate the editors of The Lancet referenced the popular hesitancy to intervene surgically with the workings of the brain. They wrote that to do so `carries a peculiar penumbra of sacrilege' [1, 2]. Penumbra of sacrilege is a memorable, even strange phrase. It is one worth unpacking as we embark on an era which will see ever more border crossings at the blood-brain barrier. By invoking popular beliefs about a penumbra of sacrilege, the editors were suggesting that psychosurgery represented a gray zone in the shadows, a desecration or violation of a sacred space, the seat of the soul, the self. And as such, they were reflecting a cultural hesitancy, a lay reluctance to pursue this work. Fortunately for those with intractable neuropsychiatric disorders, neuromodulation has evolved beyond the primitive—and barbaric—sweep of the lobotomy, and with this advance, categorical resistance to this work has dissipated. And that is all to the good. But as the field progresses, and we implant more and more devices for therapeutic and investigational purposes, we must not let the placement of electrodes become too easy. It is a decision that should be made with full awareness of its implications for patients and families. Recently, I spoke to a friend who appeared to have early essential tremor. (Some non-essential aspects of this story have been changed to protect confidentiality.) He asked me, `Do you know anything about deep brain stimulation?' I indicated that I did. `Really?', he asked, seemingly unaware of my scholarly interest in the topic [3, 4, 5, 6] and involvement as a co-investigator in the use of deep brain stimulation in the minimally conscious state [7, 8, 9]. Satisfied that I might be a credible source for some free advice, he told me that his neurologist had sent him to a neurosurgeon to see about a stimulator. I asked him how disabling his condition was. As he competently drank a cup of soda, he told me it was a bit of a

  4. In-Vivo Characterization of Glassy Carbon Micro-Electrode Arrays for Neural Applications and Histological Analysis of the Brain Tissue

    Science.gov (United States)

    Vomero, Maria

    The aim of this work is to fabricate and characterize glassy carbon Microelectrode Arrays (MEAs) for sensing and stimulating neural activity, and conduct histological analysis of the brain tissue after the implant to determine long-term performance. Neural applications often require robust electrical and electrochemical response over a long period of time, and for those applications we propose to replace the commonly used noble metals like platinum, gold and iridium with glassy carbon. We submit that such material has the potential to improve the performances of traditional neural prostheses, thanks to better charge transfer capabilities and higher electrochemical stability. Great interest and attention is given in this work, in particular, to the investigation of tissue response after several weeks of implants in rodents' brain motor cortex and the associated materials degradation. As part of this work, a new set of devices for Electrocorticography (ECoG) has been designed and fabricated to improve durability and quality of the previous generation of devices, designed and manufactured by the same research group in 2014. In-vivo long-term impedance measurements and brain activity recordings were performed to test the functionality of the neural devices. In-vitro electrical characterization of the carbon electrodes, as well as the study of the adhesion mechanisms between glassy carbon and different substrates is also part of the research described in this book.

  5. Transcranial magnetic stimulation of mouse brain using high-resolution anatomical models

    Science.gov (United States)

    Crowther, L. J.; Hadimani, R. L.; Kanthasamy, A. G.; Jiles, D. C.

    2014-05-01

    Transcranial magnetic stimulation (TMS) offers the possibility of non-invasive treatment of brain disorders in humans. Studies on animals can allow rapid progress of the research including exploring a variety of different treatment conditions. Numerical calculations using animal models are needed to help design suitable TMS coils for use in animal experiments, in particular, to estimate the electric field induced in animal brains. In this paper, we have implemented a high-resolution anatomical MRI-derived mouse model consisting of 50 tissue types to accurately calculate induced electric field in the mouse brain. Magnetic field measurements have been performed on the surface of the coil and compared with the calculations in order to validate the calculated magnetic and induced electric fields in the brain. Results show how the induced electric field is distributed in a mouse brain and allow investigation of how this could be improved for TMS studies using mice. The findings have important implications in further preclinical development of TMS for treatment of human diseases.

  6. Toward the restoration of hand use to a paralyzed monkey: brain-controlled functional electrical stimulation of forearm muscles.

    Directory of Open Access Journals (Sweden)

    Eric A Pohlmeyer

    Full Text Available Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord.

  7. How does transcranial DC stimulation of the primary motor cortex alter regional neuronal activity in the human brain?

    Science.gov (United States)

    Lang, Nicolas; Siebner, Hartwig R; Ward, Nick S; Lee, Lucy; Nitsche, Michael A; Paulus, Walter; Rothwell, John C; Lemon, Roger N; Frackowiak, Richard S

    2005-07-01

    Transcranial direct current stimulation (tDCS) of the primary motor hand area (M1) can produce lasting polarity-specific effects on corticospinal excitability and motor learning in humans. In 16 healthy volunteers, O positron emission tomography (PET) of regional cerebral blood flow (rCBF) at rest and during finger movements was used to map lasting changes in regional synaptic activity following 10 min of tDCS (+/-1 mA). Bipolar tDCS was given through electrodes placed over the left M1 and right frontopolar cortex. Eight subjects received anodal or cathodal tDCS of the left M1, respectively. When compared to sham tDCS, anodal and cathodal tDCS induced widespread increases and decreases in rCBF in cortical and subcortical areas. These changes in rCBF were of the same magnitude as task-related rCBF changes during finger movements and remained stable throughout the 50-min period of PET scanning. Relative increases in rCBF after real tDCS compared to sham tDCS were found in the left M1, right frontal pole, right primary sensorimotor cortex and posterior brain regions irrespective of polarity. With the exception of some posterior and ventral areas, anodal tDCS increased rCBF in many cortical and subcortical regions compared to cathodal tDCS. Only the left dorsal premotor cortex demonstrated an increase in movement related activity after cathodal tDCS, however, modest compared with the relatively strong movement-independent effects of tDCS. Otherwise, movement related activity was unaffected by tDCS. Our results indicate that tDCS is an effective means of provoking sustained and widespread changes in regional neuronal activity. The extensive spatial and temporal effects of tDCS need to be taken into account when tDCS is used to modify brain function. PMID:16045502

  8. Activity patterns of cultured neural networks on micro electrode arrays

    NARCIS (Netherlands)

    Rutten, W.L.C.; Pelt, van J.

    2001-01-01

    A hybrid neuro-electronic interface is a cell-cultured micro electrode array, acting as a neural information transducer for stimulation and/or recording of neural activity in the brain or the spinal cord (ventral motor region or dorsal sensory region). It consists of an array of micro electrodes on

  9. Cortical edema in moderate fluid percussion brain injury is attenuated by vagus nerve stimulation.

    Science.gov (United States)

    Clough, R W; Neese, S L; Sherill, L K; Tan, A A; Duke, A; Roosevelt, R W; Browning, R A; Smith, D C

    2007-06-29

    Development of cerebral edema (intracellular and/or extracellular water accumulation) following traumatic brain injury contributes to mortality and morbidity that accompanies brain injury. Chronic intermittent vagus nerve stimulation (VNS) initiated at either 2 h or 24 h (VNS: 30 s train of 0.5 mA, 20 Hz, biphasic pulses every 30 min) following traumatic brain injury enhances recovery of motor and cognitive function in rats in the weeks following brain injury; however, the mechanisms of facilitated recovery are unknown. The present study examines the effects of VNS on development of acute cerebral edema following unilateral fluid percussion brain injury (FPI) in rats, concomitant with assessment of their behavioral recovery. Two hours following FPI, VNS was initiated. Behavioral testing, using both beam walk and locomotor placing tasks, was conducted at 1 and 2 days following FPI. Edema was measured 48 h post-FPI by the customary method of region-specific brain weights before and after complete dehydration. Results of this study replicated that VNS initiated at 2 h after FPI: 1) effectively facilitated the recovery of vestibulomotor function at 2 days after FPI assessed by beam walk performance (P<0.01); and 2) tended to improve locomotor placing performance at the same time point (P=0.18). Most interestingly, results of this study showed that development of edema within the cerebral cortex ipsilateral to FPI was significantly attenuated at 48 h in FPI rats receiving VNS compared with non-VNS FPI rats (P<0.04). Finally, a correlation analysis between beam walk performance and cerebral edema following FPI revealed a significant inverse correlation between behavior performance and cerebral edema. Together, these results suggest that VNS facilitation of motor recovery following experimental brain injury in rats is associated with VNS-mediated attenuation of cerebral edema. PMID:17543463

  10. Enhancing multiple object tracking performance with noninvasive brain stimulation: A causal role for the anterior intraparietal sulcus

    Directory of Open Access Journals (Sweden)

    Eric Joshua Blumberg

    2015-02-01

    Full Text Available Multiple object tracking (MOT is a complex task recruiting a distributed network of brain regions. There are also marked individual differences in MOT performance. A positive causal relationship between the anterior intraparietal sulcus (AIPS, an integral region in the MOT attention network and inter-individual variation in MOT performance has not been previously established. The present study used transcranial direction current stimulation (tDCS, a form of non-invasive brain stimulation, in order to examine such a causal link. Active anodal stimulation was applied to the right AIPS and the left dorsolateral prefrontal cortex (and sham stimulation, an area associated with working memory (but not MOT while participants completed a MOT task. Stimulation to the right AIPS significantly improved MOT accuracy more than the other two conditions. The results confirm a causal role of the AIPS in the MOT task and illustrate that transcranial direct current stimulation has the ability to improve MOT performance.

  11. Targeting neural endophenotypes of eating disorders with non-invasive brain stimulation

    Directory of Open Access Journals (Sweden)

    Katharine A Dunlop

    2016-02-01

    Full Text Available The term eating disorders (ED encompasses a wide variety of disordered eating and compensatory behaviors, and so the term is associated with considerable clinical and phenotypic heterogeneity. This heterogeneity makes optimizing treatment techniques difficult. One class of treatments is non-invasive brain stimulation (NIBS. NIBS, including repetitive transcranial magnetic stimulation (rTMS and transcranial direct current stimulation (tDCS are accessible forms of neuromodulation that alter the cortical excitability of a target brain region. It is crucial for NIBS to be successful that the target is well selected for the patient population in question. Targets may best be selected by stepping back from conventional DSM-5 diagnostic criteria to identify neural substrates of more basic phenotypes, including behavior related rewards and punishment cognitive control, and social processes. These phenotypic dimensions have been recently laid out by the Research Domain Criteria (RDoC initiative. Consequently, this review is intended to identify potential dimensions as outlined by the RDoC and their underlying behavioral and neurobiological targets associated with ED as potential candidates for NIBS and review the available literature on rTMS and tDCS in ED. This review systematically reviews abnormal neural circuitry in ED within the RDoC framework, and also systematically reviews the available literature investigating NIBS as a treatment for ED.

  12. Targeting Neural Endophenotypes of Eating Disorders with Non-invasive Brain Stimulation

    Science.gov (United States)

    Dunlop, Katharine A.; Woodside, Blake; Downar, Jonathan

    2016-01-01

    The term “eating disorders” (ED) encompasses a wide variety of disordered eating and compensatory behaviors, and so the term is associated with considerable clinical and phenotypic heterogeneity. This heterogeneity makes optimizing treatment techniques difficult. One class of treatments is non-invasive brain stimulation (NIBS). NIBS, including repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), are accessible forms of neuromodulation that alter the cortical excitability of a target brain region. It is crucial for NIBS to be successful that the target is well selected for the patient population in question. Targets may best be selected by stepping back from conventional DSM-5 diagnostic criteria to identify neural substrates of more basic phenotypes, including behavior related to rewards and punishment, cognitive control, and social processes. These phenotypic dimensions have been recently laid out by the Research Domain Criteria (RDoC) initiative. Consequently, this review is intended to identify potential dimensions as outlined by the RDoC and the underlying behavioral and neurobiological targets associated with ED. This review will also identify candidate targets for NIBS based on these dimensions and review the available literature on rTMS and tDCS in ED. This review systematically reviews abnormal neural circuitry in ED within the RDoC framework, and also systematically reviews the available literature investigating NIBS as a treatment for ED. PMID:26909013

  13. No impact of deep brain stimulation on fear-potentiated startle in obsessive-compulsive disorder.

    Science.gov (United States)

    Baas, Johanna M P; Klumpers, Floris; Mantione, Mariska H; Figee, Martijn; Vulink, Nienke C; Schuurman, P Richard; Mazaheri, Ali; Denys, Damiaan

    2014-01-01

    Deep brain stimulation (DBS) of the ventral internal capsule is effective in treating therapy refractory obsessive-compulsive disorder (OCD). Given the close proximity of the stimulation site to the stria terminalis (BNST), we hypothesized that the striking decrease in anxiety symptoms following DBS could be the result of the modulation of contextual anxiety. However, the effect of DBS in this region on contextual anxiety is as of yet unknown. Thus, the current study investigated the effect of DBS on contextual anxiety in an experimental threat of shock paradigm. Eight patients with DBS treatment for severe OCD were tested in a double-blind crossover design with randomly assigned 2-week periods of active and sham stimulation. DBS resulted in significant decrease of obsessive-compulsive symptoms, anxiety, and depression. However, even though the threat manipulation resulted in a clear context-potentiated startle effect, none of the parameters derived from the startle recordings was modulated by the DBS. This suggests that DBS in the ventral internal capsule is effective in treating anxiety symptoms of OCD without modulating the startle circuitry. We hypothesize that the anxiety symptoms present in OCD are likely distinct from the pathological brain circuits in defensive states of other anxiety disorders. PMID:25249953

  14. No Impact of Deep Brain Stimulation on Fear-Potentiated Startle in Obsessive–Compulsive Disorder

    Science.gov (United States)

    Baas, Johanna M. P.; Klumpers, Floris; Mantione, Mariska H.; Figee, Martijn; Vulink, Nienke C.; Schuurman, P. Richard; Mazaheri, Ali; Denys, Damiaan

    2014-01-01

    Deep brain stimulation (DBS) of the ventral internal capsule is effective in treating therapy refractory obsessive–compulsive disorder (OCD). Given the close proximity of the stimulation site to the stria terminalis (BNST), we hypothesized that the striking decrease in anxiety symptoms following DBS could be the result of the modulation of contextual anxiety. However, the effect of DBS in this region on contextual anxiety is as of yet unknown. Thus, the current study investigated the effect of DBS on contextual anxiety in an experimental threat of shock paradigm. Eight patients with DBS treatment for severe OCD were tested in a double-blind crossover design with randomly assigned 2-week periods of active and sham stimulation. DBS resulted in significant decrease of obsessive–compulsive symptoms, anxiety, and depression. However, even though the threat manipulation resulted in a clear context-potentiated startle effect, none of the parameters derived from the startle recordings was modulated by the DBS. This suggests that DBS in the ventral internal capsule is effective in treating anxiety symptoms of OCD without modulating the startle circuitry. We hypothesize that the anxiety symptoms present in OCD are likely distinct from the pathological brain circuits in defensive states of other anxiety disorders. PMID:25249953

  15. No impact of deep brain stimulation on fear-potentiated startle in obsessive-compulsive disorder

    Directory of Open Access Journals (Sweden)

    Johanna M.P. Baas

    2014-09-01

    Full Text Available Deep brain stimulation (DBS of the ventral internal capsule is effective in treating therapy refractory obsessive-compulsive disorder (OCD. Given the close proximity of the stimulation site to the stria terminalis (BNST, we hypothesized that the striking decrease in anxiety symptoms following DBS could be the result of the modulation of contextual anxiety. However, the effect of DBS in this region on contextual anxiety is as of yet unknown. Thus, the current study investigated the effect of DBS on contextual anxiety in an experimental threat of shock paradigm. Eight patients with DBS treatment for severe OCD were tested in a double-blind crossover design with randomly assigned two-week periods of active and sham stimulation. DBS resulted in significant decrease of obsessive-compulsive symptoms, anxiety and depression. However, even though the threat manipulation resulted in a clear context potentiated startle effect, none of the parameters derived from the startle recordings was modulated by the DBS. This suggests that DBS in the ventral internal capsule is effective in treating anxiety symptoms of obsessive-compulsive disorder without modulating the startle circuitry. We hypothesize that the anxiety symptoms present in OCD are likely distinct from the pathological brain circuits in defensive states of other anxiety disorders.

  16. Stimulation of phosphoinositide hydrolysis by a novel substance partially purified from rat and bovine brain

    International Nuclear Information System (INIS)

    This study demonstrates the partial purification of a potentially novel substance from rat and bovine brain. Whole brains were homogenized in distilled water, then heated at 1000C for 30 min. The water extract was dialyzed and the 3H-inositol monophosphate (3H-IP) using lithium-treated slices of rat cerebral cortex prelabelled with 3H-myo-inositol. A major peak of activity was observed in fractions from the molecular weight range of 800-1300 daltons. Stimulation of phosphoinositide hydrolysis by this material was time-dependent and dose-related. Maximal stimulation of 3H-IP (323% of control) required 10mg/ml of bovine material and was observed at 30 minutes. These effects could not be mimicked by a number of substances of similar molecular weight (e.g. substance P, neurotensin, angiotensin II, bradykinin). Furthermore, the effects of this material were not blocked by antagonist drugs which act at the alpha-adrenoceptor, muscarinic cholinoceptor, 5-HT2 receptor, substance P receptor, or neurotensin receptor. These results indicate that the substance isolated may be a novel neuroactive molecule which has receptors coupled to phosphoinositide hydrolysis in brain

  17. Understanding deep brain stimulation in obsessive compulsive disorder: A preclinical study into the mechanism of action and behaviour

    NARCIS (Netherlands)

    A. van Dijk

    2013-01-01

    We see a strong impact of deep brain stimulation (DBS) on several aspects of OCD (obsessive compulsive disorder). DBS in different brain areas affects compulsive behaviour, conditioned and unconditioned anxiety. DBS in the internal capsule (IC) shows the most promising behavioural results by uniquel

  18. Large charge-storage-capacity iridium/ruthenium oxide coatings as promising material for neural stimulating electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Ullah, Nehar, E-mail: nehar.ullah@mail.mcgill.ca; Omanovic, Sasha

    2015-06-01

    Electrochemical and topographical/structural/morphological properties of thermally prepared Ir/Ru-oxide coatings of various compositions formed on a Ti substrate were investigated. An apparent electrochemically active surface area (AEASA) and charge storage capacity (CSC) were determined. The freshly-prepared Ir{sub 0.6}Ru{sub 0.4}-oxide coating was found to offer the largest AEASA and CSC; however, after exposing all the coatings to prolonged extreme electrochemical cycling in phosphate buffered saline pH 7.4, within a 5 V potential window (“torturing”), the Ir{sub 0.8}Ru{sub 0.2}-oxide coating yielded both the largest AEASA (1540 cm{sup 2}) and CSC (27 mC cm{sup −2}). Under the same experimental condition, the Ir{sub 0.8}Ru{sub 0.2}-oxide coating was found to yield by a 56% higher CSC than the current state-of-the-art neural stimulating electrode, Ir-oxide, making it a good candidate for further optimization and possible application as a neural stimulating electrode. - Highlights: • Ir/Ru-oxide coatings were formed thermally on a Ti substrate. • Electrochemical properties of Ir/Ru-oxide coatings were investigated. • Ir{sub 0.8}–Ru{sub 0.2}-oxide yielded highest apparent electrochemically-active surface area. • Ir{sub 0.8}–Ru{sub 0.2}-oxide yielded highest charge storage capacity. • Charge storage capacity is by 56% higher than current state-of-the-art, Ir-oxide.

  19. Post-mortem Findings in Huntington’s Deep Brain Stimulation: A Moving Target Due to Atrophy

    OpenAIRE

    Vedam-Mai, Vinata; Martinez-Ramirez, Daniel; Hilliard, Justin D.; Carbunaru, Samuel; Yachnis, Anthony T.; Bloom, Joshua; Keeling, Peyton; Awe, Lisa; Foote, Kelly D.; Okun, Michael S.

    2016-01-01

    Background Deep brain stimulation (DBS) has been shown to be effective for Parkinson’s disease, essential tremor, and primary dystonia. However, mixed results have been reported in Huntington’s disease (HD). Case Report A single case of HD DBS was identified from the University of Florida DBS Brain Tissue Network. The clinical presentation, evolution, surgical planning, DBS parameters, clinical outcomes, and brain pathological changes are summarized. Discussion This case of HD DBS revealed th...

  20. Cognitive and Neurophysiological Effects of Non-invasive Brain Stimulation in Stroke Patients after Motor Rehabilitation.

    Science.gov (United States)

    D'Agata, Federico; Peila, Elena; Cicerale, Alessandro; Caglio, Marcella M; Caroppo, Paola; Vighetti, Sergio; Piedimonte, Alessandro; Minuto, Alice; Campagnoli, Marcello; Salatino, Adriana; Molo, Maria T; Mortara, Paolo; Pinessi, Lorenzo; Massazza, Giuseppe

    2016-01-01

    The primary aim of this study was to evaluate and compare the effectiveness of two specific Non-Invasive Brain Stimulation (NIBS) paradigms, the repetitive Transcranial Magnetic Stimulation (rTMS), and transcranial Direct Current Stimulation (tDCS), in the upper limb rehabilitation of patients with stroke. Short and long term outcomes (after 3 and 6 months, respectively) were evaluated. We measured, at multiple time points, the manual dexterity using a validated clinical scale (ARAT), electroencephalography auditory event related potentials, and neuropsychological performances in patients with chronic stroke of middle severity. Thirty four patients were enrolled and randomized. The intervention group was treated with a NIBS protocol longer than usual, applying a second cycle of stimulation, after a washout period, using different techniques in the two cycles (rTMS/tDCS). We compared the results with a control group treated with sham stimulation. We split the data analysis into three studies. In this first study we examined if a cumulative effect was clinically visible. In the second study we compared the effects of the two techniques. In the third study we explored if patients with minor cognitive impairment have most benefit from the treatment and if cognitive and motor outcomes were correlated. We found that the impairment in some cognitive domains cannot be considered an exclusion criterion for rehabilitation with NIBS. ERP improved, related to cognitive and attentional processes after stimulation on the motor cortex, but transitorily. This effect could be linked to the restoration of hemispheric balance or by the effects of distant connections. In our study the effects of the two NIBS were comparable, with some advantages using tDCS vs. rTMS in stroke rehabilitation. Finally we found that more than one cycle (2-4 weeks), spaced out by washout periods, should be used, only in responder patients, to obtain clinical relevant results. PMID:27445730

  1. Effects of deep brain stimulation on prepulse inhibition in obsessive-compulsive disorder.

    Science.gov (United States)

    Kohl, S; Gruendler, T O J; Huys, D; Sildatke, E; Dembek, T A; Hellmich, M; Vorderwulbecke, M; Timmermann, L; Ahmari, S E; Klosterkoetter, J; Jessen, F; Sturm, V; Visser-Vandewalle, V; Kuhn, J

    2015-01-01

    Owing to a high response rate, deep brain stimulation (DBS) of the ventral striatal area has been approved for treatment-refractory obsessive-compulsive disorder (tr-OCD). Many basic issues regarding DBS for tr-OCD are still not understood, in particular, the mechanisms of action and the origin of side effects. We measured prepulse inhibition (PPI) in treatment-refractory OCD patients undergoing DBS of the nucleus accumbens (NAcc) and matched controls. As PPI has been used in animal DBS studies, it is highly suitable for translational research. Eight patients receiving DBS, eight patients with pharmacological treatment and eight age-matched healthy controls participated in our study. PPI was measured twice in the DBS group: one session with the stimulator switched on and one session with the stimulator switched off. OCD patients in the pharmacologic group took part in a single session. Controls were tested twice, to ensure stability of data. Statistical analysis revealed significant differences between controls and (1) patients with pharmacological treatment and (2) OCD DBS patients when the stimulation was switched off. Switching the stimulator on led to an increase in PPI at a stimulus-onset asynchrony of 200 ms. There was no significant difference in PPI between OCD patients being stimulated and the control group. This study shows that NAcc-DBS leads to an increase in PPI in tr-OCD patients towards a level seen in healthy controls. Assuming that PPI impairments partially reflect the neurobiological substrates of OCD, our results show that DBS of the NAcc may improve sensorimotor gating via correction of dysfunctional neural substrates. Bearing in mind that PPI is based on a complex and multilayered network, our data confirm that DBS most likely takes effect via network modulation. PMID:26556284

  2. Image-Guided Focused Ultrasound-Mediated Regional Brain Stimulation in Sheep.

    Science.gov (United States)

    Lee, Wonhye; Lee, Stephanie D; Park, Michael Y; Foley, Lori; Purcell-Estabrook, Erin; Kim, Hyungmin; Fischer, Krisztina; Maeng, Lee-So; Yoo, Seung-Schik

    2016-02-01

    Non-invasive brain stimulation using focused ultrasound has largely been carried out in small animals. In the present study, we applied stimulatory focused ultrasound transcranially to the primary sensorimotor (SM1) and visual (V1) brain areas in sheep (Dorset, all female, n = 8), under the guidance of magnetic resonance imaging, and examined the electrophysiologic responses. By use of a 250-kHz focused ultrasound transducer, the area was sonicated in pulsed mode (tone-burst duration of 1 ms, duty cycle of 50%) for 300 ms. The acoustic intensity at the focal target was varied up to a spatial peak pulse-average intensity (Isppa) of 14.3 W/cm(2). Sonication of SM1 elicited electromyographic responses from the contralateral hind leg, whereas stimulation of V1 generated electroencephalographic potentials. These responses were detected only above a certain acoustic intensity, and the threshold intensity, as well as the degree of responses, varied among sheep. Post-sonication animal behavior was normal, but minor microhemorrhages were observed from the V1 areas exposed to highly repetitive sonication (every second for ≥500 times for electroencephalographic measurements, Isppa = 6.6-10.5 W/cm(2), mechanical index = 0.9-1.2). Our results suggest the potential translational utility of focused ultrasound as a new brain stimulation modality, yet also call for caution in the use of an excessive number of sonications. PMID:26525652

  3. Non-invasive brain stimulation enhances the effects of Melodic Intonation Therapy

    Directory of Open Access Journals (Sweden)

    Bradley W. Vines

    2011-09-01

    Full Text Available Research has suggested that a fronto-temporal network in the right hemisphere may be responsible for mediating Melodic Intonation Therapy’s positive effects on speech recovery. We investigated the potential for a non-invasive brain stimulation technique, transcranial direct current stimulation (tDCS, to augment the benefits of MIT in patients with non-fluent aphasia by modulating neural activity in the brain during treatment with MIT. The polarity of the current applied to the scalp determines the effects of tDCS on the underlying tissue: anodal tDCS increases excitability, whereas cathodal tDCS decreases excitability. We applied anodal tDCS to the posterior inferior frontal gyrus (IFG of the right hemisphere, an area that has been shown to both contribute to singing through the mapping of sounds to ariculatory actions and serve as a key region in the process of recovery from aphasia, particularly in patients with large left hemispheric lesions. The stimulation was applied while patients were treated with MIT by a trained therapist. Six patients with moderate to severe non-fluent aphasia underwent three consecutive days of anodal-tDCS+MIT, and an equivalent series of sham-tDCS+MIT. The two treatment series were separated by one week, and the order in which the treatments were administered was randomized. Compared to the effects of sham-tDCS+MIT, anodal-tDCS+MIT led to significant improvements in fluency of speech. These results support the hypothesis that, as the brain seeks to reorganize and compensate for damage to left-hemisphere language centers, combining anodal-tDCS with MIT may further recovery from post-stroke aphasia by enhancing activity in a right-hemisphere sensorimotor network for articulation.

  4. Deep brain stimulation for aggressive behavior and obsessive-compulsive disorder.

    Science.gov (United States)

    Messina, Giuseppe; Islam, Lucrezia; Cordella, Roberto; Gambini, Orsola; Franzini, Angelo

    2016-06-01

    Drug-resistant obsessive-compulsive disorder and aggressive behavior are two severely disabling psychiatric conditions which may carry a certain burden on the patients themselves and on their families. In the last decade, the fields of interests of deep brain stimulation (DBS) also encompass psychiatric disorders, supported by imaging and neurophysiological techniques. We here report our institutional experience with the two above-mentioned disorders, describing the procedure commonly employed and the results obtained. Refinement of such techniques, possibly relying on advanced magnetic resonance imaging (MRI), together with probabilistic pictures of field of activation models, could shed more light into this complex field of investigation; further studies are necessary to confirm and make actual results a starting point to new and more precise methodologies in this stimulating research field. PMID:27007543

  5. Secondary Hyperalgesia Phenotypes Exhibit Differences in Brain Activation during Noxious Stimulation

    DEFF Research Database (Denmark)

    Asghar, Mohammad Sohail; Pereira, Manuel Pedro; Werner, Mads Utke; Mårtensson, Johan; Larsson, Henrik B W; Dahl, Jørgen Berg

    2015-01-01

    the burn-injury) (p < 0.05). After the burn-injury, we found significant differences between responders during noxious stimulation of both primary (p < 0.01) and secondary hyperalgesia (p ≤ 0.04) skin areas. A decreased volume of the right (p = 0.001) and left caudate nucleus (p = 0.01) was detected....... To study differences in the propensity to develop central sensitization we examined differences in brain activity and anatomy according to individual phenotypical expression of secondary hyperalgesia by magnetic resonance imaging. Forty healthy volunteers received a first-degree burn-injury (47°C, 7...... hyperalgesia areas after burn-injury. In addition, T1-weighted images were used to measure differences in gray-matter density in cortical and subcortical regions of the brain. We found significant differences in neuronal activity between high- and low-sensitization responders at baseline (before application of...

  6. Oscillations in Pedunculopontine Nucleus in Parkinson's disease and its relationship with deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Min Li

    2015-09-01

    Full Text Available The recent development of deep brain stimulation (DBS of the pedunculopontine nucleus (PPN for the treatment of parkinsonian patients, particularly those in advanced stages with axial symptoms, has ignited interest into the study of this brain nucleus. In contrast to the extensively studied alterations of neural activity that occur in the basal ganglia in Parkinson’s disease (PD, our understanding of the activity of the PPN remains insufficient. In recent years, however, a series of studies recording oscillatory activity in the PPN of parkinsonian patients have made important findings. Here, we briefly review recent studies that explore the different kinds of oscillations observed in the PPN of parkinsonian patients, and how they underlie the pathophysiology of PD and the efficacy of PPN DBS in these disorders.

  7. Deep brain stimulation of nucleus accumbens region in alcoholism affects reward processing.

    Directory of Open Access Journals (Sweden)

    Marcus Heldmann

    Full Text Available The influence of bilateral deep brain stimulation (DBS of the nucleus nucleus (NAcc on the processing of reward in a gambling paradigm was investigated using H(2[(15O]-PET (positron emission tomography in a 38-year-old man treated for severe alcohol addiction. Behavioral data analysis revealed a less risky, more careful choice behavior under active DBS compared to DBS switched off. PET showed win- and loss-related activations in the paracingulate cortex, temporal poles, precuneus and hippocampus under active DBS, brain areas that have been implicated in action monitoring and behavioral control. Except for the temporal pole these activations were not seen when DBS was deactivated. These findings suggest that DBS of the NAcc may act partially by improving behavioral control.

  8. Modulating pathological oscillations by rhythmic non-invasive brain stimulation – a therapeutic concept?

    Directory of Open Access Journals (Sweden)

    Lutz eKrawinkel

    2015-03-01

    Full Text Available A large amount of studies of the last decades revealed an association between human behaviour and oscillatory activity in the human brain. Alike, abnormalities of oscillatory activity were related with pathological behaviour in many neuropsychiatric disorders, such as in Parkinson’s disease (PD or in schizophrenia (SCZ. As a therapeutic tool, non-invasive brain stimulation (NIBS has demonstrated the potential to improve behavioural performance in patients suffering from neuropsychiatric disorders. Since evidence accumulates that NIBS might be able to modulate oscillatory activity and related behaviour in a scientific setting, this review focuses on discussing potential interventional strategies to target abnormalities in oscillatory activity in neuropsychiatric disorders. In particular, we will review oscillatory changes described in patients after stroke, with PD or suffering from SCZ. Potential ways of targeting interventionally the underlying pathological oscillations to improve related pathological behaviour will be further discussed.

  9. Pallidal Deep Brain Stimulation in the Treatment of Huntington’s Chorea

    OpenAIRE

    Loutfi, Ghada; Linder, Jan; Hariz, Gun-Marie; Hariz, Marwan,; Blomstedt, Patric

    2014-01-01

    Despite the success of deep brain stimulation (DBS) in various movement disorders, its use in Huntington´s Disease (HD) has been limited. So far, promising results of pallidal DBS have been reported in 7 patients with HD. We performed bilateral pallidal DBS in a 59 year old woman with HD since 12 years and severe motor symptoms. At the evaluation after 12 months the effect was deemed satisfactory mainly concerning the patient’s choreatic symptoms. However, the improvement according to the uni...

  10. Hold your horses: impulsivity, deep brain stimulation, and medication in parkinsonism.

    Science.gov (United States)

    Frank, Michael J; Samanta, Johan; Moustafa, Ahmed A; Sherman, Scott J

    2007-11-23

    Deep brain stimulation (DBS) of the subthalamic nucleus markedly improves the motor symptoms of Parkinson's disease, but causes cognitive side effects such as impulsivity. We showed that DBS selectively interferes with the normal ability to slow down when faced with decision conflict. While on DBS, patients actually sped up their decisions under high-conflict conditions. This form of impulsivity was not affected by dopaminergic medication status. Instead, medication impaired patients' ability to learn from negative decision outcomes. These findings implicate independent mechanisms leading to impulsivity in treated Parkinson's patients and were predicted by a single neurocomputational model of the basal ganglia. PMID:17962524

  11. Social anxiety disorder: radio electric asymmetric conveyor brain stimulation versus sertraline

    Directory of Open Access Journals (Sweden)

    Fontani V

    2011-11-01

    Full Text Available Vania Fontani1, Piero Mannu1,2, Alessandro Castagna1, Salvatore Rinaldi11Department of Neuro Psycho Physio Pathology, Rinaldi Fontani Institute, Florence; 2Psychic Studies Center, Cagliari, ItalyPurpose: Social anxiety disorder (SAD is a disabling condition that affects almost 5% of the general population. Many types of drugs have shown their efficacy in the treatment of SAD. There are also some data regarding psychotherapies, but no data are available today about the efficacy of brain stimulation techniques. The aim of the study is to compare the efficacy of noninvasive brain stimulation neuro psycho physical optimization (NPPO protocol performed by radio electric asymmetric conveyor (REAC with that of sertraline in adults with SAD.Patients and methods: Twenty SAD patients on sertraline were compared with 23 SAD patients who refused any drug treatment and who chose to be treated with NPPO-REAC brain stimulation. This was a 6-month, open-label, naturalistic study. Patients on sertraline received flexible doses, whereas NPPO-REAC patients received two 18-session cycles of treatment. Clinical Global Improvement scale items "much improved" or "very much improved" and Liebowitz Social Anxiety Scale total score variation on fear and avoidance components were used to detect the results. The statistical analysis was performed with t-test. All measures <0.05 have been considered statistically significant.Results: Ten of 23 subjects on NPPO-REAC and six of the 20 taking sertraline were much improved or very much improved 1 month after the first NPPO-REAC cycle (t1. Sixteen of the subjects on NPPO-REAC and ten of the subjects taking sertraline were much improved or very much improved 1 month after the second NPPO-REAC cycle (t2. In respect of the Liebowitz Social Anxiety Scale, at t1 NPPO-REAC resulted in statistically more efficacy for sertraline on both fear and avoidance total scores. At t2, NPPO-REAC resulted in statistically more efficacy for

  12. New Insights Offered by a Computational Model of Deep Brain Stimulation

    DEFF Research Database (Denmark)

    Modolo, J.; Mosekilde, Erik; Beuter, A.

    Deep brain stimulation (DBS) is a standard neurosurgical procedure used to treat motor symptoms in about 5% of patients with Parkinson's disease (PD). Despite the indisputable success of this procedure, the biological mechanisms underlying the clinical benefits of DBS have not yet been fully...... exploring the physiological mechanisms which respond to this treatment strategy (i.e., DBS). Finally, we present new insights into the ways this computational model may help to elucidate the dynamic network effects produced in a cerebral structure when DBS is applied. (C) 2007 Elsevier Ltd. All rights...

  13. The Third Annual Deep Brain Stimulation Think Tank: A Review of Emerging Issues and Technologies

    Directory of Open Access Journals (Sweden)

    P. Justin eRossi

    2016-04-01

    Full Text Available This review summarizes the most contemporary clinical, electrophysiological, imaging, and computational work on DBS for the treatment of neurological and neuropsychiatric disease. Significant innovations of the past year are emphasized; these advances were presented at the 3rd Annual Deep Brain Stimulation Think Tank. The Think Tank’s contributors represent a unique multidisciplinary ensemble of expert neurologists, neurosurgeons, neuropsychologists, psychiatrists, scientists, engineers, and members of industry. Presentations and discussions covered a broad range of topics, including policy and advocacy considerations for the future of DBS, connectomic approaches to DBS targeting, developments in electrophysiology and related strides toward responsive DBS systems, and recent developments in sensor and device technologies.

  14. Anatomical correlates for category-specific naming of objects and actions: a brain stimulation mapping study.

    Science.gov (United States)

    Lubrano, Vincent; Filleron, Thomas; Démonet, Jean-François; Roux, Franck-Emmanuel

    2014-02-01

    The production of object and action words can be dissociated in aphasics, yet their anatomical correlates have been difficult to distinguish in functional imaging studies. To investigate the extent to which the cortical neural networks underlying object- and action-naming processing overlap, we performed electrostimulation mapping (ESM), which is a neurosurgical mapping technique routinely used to examine language function during brain-tumor resections. Forty-one right-handed patients who had surgery for a brain tumor were asked to perform overt naming of object and action pictures under stimulation. Overall, 73 out of the 633 stimulated cortical sites (11.5%) were associated with stimulation-induced language interferences. These interference sites were very much localized (<1 cm(2) ), and showed substantial variability across individuals in their exact localization. Stimulation interfered with both object and action naming over 44 sites, whereas it specifically interfered with object naming over 19 sites and with action naming over 10 sites. Specific object-naming sites were mainly identified in Broca's area (Brodmann area 44/45) and the temporal cortex, whereas action-naming specific sites were mainly identified in the posterior midfrontal gyrus (Brodmann area 6/9) and Broca's area (P = 0.003 by the Fisher's exact test). The anatomical loci we emphasized are in line with a cortical distinction between objects and actions based on conceptual/semantic features, so the prefrontal/premotor cortex would preferentially support sensorimotor contingencies associated with actions, whereas the temporal cortex would preferentially underpin (functional) properties of objects. PMID:23015527

  15. Pallidal Deep Brain Stimulation Improves Higher Control of the Oculomotor System in Parkinson's Disease.

    Science.gov (United States)

    Antoniades, Chrystalina A; Rebelo, Pedro; Kennard, Christopher; Aziz, Tipu Z; Green, Alexander L; FitzGerald, James J

    2015-09-23

    The frontal cortex and basal ganglia form a set of parallel but mostly segregated circuits called cortico-basal ganglia loops. The oculomotor loop controls eye movements and can direct relatively simple movements, such as reflexive prosaccades, without external help but needs input from "higher" loops for more complex behaviors. The antisaccade task requires the dorsolateral prefrontal cortex, which is part of the prefrontal loop. Information flows from prefrontal to oculomotor circuits in the striatum, and directional errors in this task can be considered a measure of failure of prefrontal control over the oculomotor loop. The antisaccadic error rate (AER) is increased in Parkinson's disease (PD). Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has no effect on the AER, but a previous case suggested that DBS of the globus pallidus interna (GPi) might. Our aim was to compare the effects of STN DBS and GPi DBS on the AER. We tested eye movements in 14 human DBS patients and 10 controls. GPi DBS substantially reduced the AER, restoring lost higher control over oculomotor function. Interloop information flow involves striatal neurons that receive cortical input and project to pallidum. They are normally silent when quiescent, but in PD they fire randomly, creating noise that may account for the degradation in interloop control. The reduced AER with GPi DBS could be explained by retrograde stimulation of striatopallidal axons with consequent activation of inhibitory collaterals and reduction in background striatal firing rates. This study may help explain aspects of PD pathophysiology and the mechanism of action of GPi DBS. Significance statement: Parkinson's disease causes symptoms including stiffness, slowness of movement, and tremor. Electrical stimulation of specific areas deep in the brain can effectively treat these symptoms, but exactly how is not fully understood. Part of the cause of such symptoms may be impairments in the way information flows

  16. Towards Brain-Computer Interface Control of a 6-Degree-of-Freedom Robotic Arm Using Dry EEG Electrodes

    OpenAIRE

    Alexander Astaras; Nikolaos Moustakas; Alkinoos Athanasiou; Aristides Gogoussis

    2013-01-01

    Introduction. Development of a robotic arm that can be operated using an exoskeletal position sensing harness as well as a dry electrode brain-computer interface headset. Design priorities comprise an intuitive and immersive user interface, fast and smooth movement, portability, and cost minimization. Materials and Methods. A robotic arm prototype capable of moving along 6 degrees of freedom has been developed, along with an exoskeletal position sensing harness which was used to control it. C...

  17. Characterization of particulate cyclic nucleotide phosphodiesterases from bovine brain: Purification of a distinct cGMP-stimulated isoenzyme

    International Nuclear Information System (INIS)

    In the absence of detergent, ∼80-85% of the total cGMP-stimulated phosphodiesterase (PDE) activity in bovine brain was associated with washed particulate fractions; ∼85-90% of the calmodulin-sensitive PDE was soluble. Particulate cGMP-stimulated PDE was higher in cerebral cortical gray matter than in other regions. Homogenization of the brain particulate fraction in 1% Lubrol increased cGMP-stimulated activity ∼100% and calmodulin-stimulated ∼400-500%. Although 1% Lubrol readily solubilized these PDE activities, ∼75% of the cAMP PDE activity (0.5 μM [3H]cAMP) that was not affected by cGMP was not solubilized. This cAMP PDE activity was very sensitive to inhibition by Rolipram but not cilostamide. Thus, three different PDE types, i.e., cGMP stimulated, calmodulin sensitive, and Rolipram inhibited, are associated in different ways with crude bovine brain particulate fractions. The brain enzyme exhibited a slightly greater subunit Mr than did soluble forms from calf liver or bovine brain, as evidenced by protein staining or immunoblotting after polyacrylamide gel electrophoresis under denaturing conditions. Incubation of brain particulate and liver soluble cGMP-stimulated PDEs with V8 protease produced several peptides of similar size, as well as at least two distinct fragments of ∼27 kDa from the brain and ∼23 kDa from the liver enzyme. After photolabeling in the presence of [32P]cGMP and digestion with V8 protease, [32P]cGMP in each PDE was predominantly recovered with a peptide of ∼14 kDa. All of these observations are consistent with the existence of at least two discrete forms (isoenzymes) of cGMP-stimulated PDE

  18. Theta burst stimulation to characterize changes in brain plasticity following mild traumatic brain injury: a proof-of-principle study

    Science.gov (United States)

    Tremblay, Sara; Vernet, Marine; Bashir, Shahid; Pascual-Leone, Alvaro; Théoret, Hugo

    2016-01-01

    Purpose Recent studies investigating the acute effects of mild traumatic brain injury (mTBI) suggest the presence of unbalanced excitatory and inhibitory mechanisms within primary motor cortex (M1). Whether these abnormalities are associated with impaired synaptic plasticity remains unknown. Methods The effects of continuous theta burst stimulation (cTBS) on transcranial magnetic stimulation-induced motor evoked potentials (MEPs) were assessed on average two weeks and six weeks following mTBI in five individuals. Results The procedure was well-tolerated by all participants. Continuous TBS failed to induce a significant reduction of MEP amplitudes two weeks after the injury, but response to cTBS normalized six weeks following injury, as a majority of patients became asymptomatic. Conclusions These preliminary results suggest that cTBS can be used to assess M1 synaptic plasticity in the acute and sub-acute phases following mTBI and may provide insights into neurobiological substrates of symptoms and consequences of mTBI. PMID:25735241

  19. Assessing brain plasticity across the lifespan with transcranial magnetic stimulation: Why, how, and what is the ultimate goal?

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    Catarina eFreitas

    2013-04-01

    Full Text Available Sustaining brain and cognitive function across the lifespan must be one of the main biomedical goals of the XXI Century. We need to aim to prevent neuropsychiatric diseases and, thus, to identify and remediate brain and cognitive dysfunction before clinical symptoms manifest and disability develops. The brain undergoes a complex array of changes from developmental years into old age, putatively the underpinnings of changes in cognition and behavior throughout life. A functionally ‘normal’ brain is a changing brain, a brain whose capacity and mechanisms of change are shifting appropriately from one time-point to another in a given individual’s life. Therefore, assessing the mechanisms of brain plasticity across the lifespan is critical to gain insight into an individual’s brain health. Indexing brain plasticity in humans is possible with transcranial magnetic stimulation (TMS, which, in combination with neuroimaging, provides a powerful tool for exploring local cortical and brain network plasticity. Here, we review investigations to date, summarize findings, and discuss some of the challenges that need to be solved to enhance the use of TMS measures of brain plasticity across all ages. Ultimately, TMS measures of plasticity can become the foundation for a brain health index to enable objective correlates of an individual’s brain health over time, assessment across diseases and disorders, and reliable evaluation of indicators of efficacy of future preventive and therapeutic interventions.

  20. Brain activity modification produced by a single radioelectric asymmetric brain stimulation pulse: a new tool for neuropsychiatric treatments. Preliminary fMRI study

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    Castagna A

    2011-10-01

    Full Text Available Salvatore Rinaldi1,2, Vania Fontani1, Alessandro Castagna1 1Department of Neuro-Psycho-Physio Pathology, Rinaldi Fontani Institute, Florence, Italy; 2Medical School of Occupational Medicine, University of Florence, Florence, Italy Purpose: Radioelectric asymmetric brain stimulation technology with its treatment protocols has shown efficacy in various psychiatric disorders. The aim of this work was to highlight the mechanisms by which these positive effects are achieved. The current study was conducted to determine whether a single 500-millisecond radioelectric asymmetric conveyor (REAC brain stimulation pulse (BSP, applied to the ear, can effect a modification of brain activity that is detectable using functional magnetic resonance imaging (fMRI. Methods: Ten healthy volunteers, six females and four males, underwent fMRI during a simple finger-tapping motor task before and after receiving a single 500-millisecond REAC-BSP. Results: The fMRI results indicate that the average variation in task-induced encephalic activation patterns is lower in subjects following the single REAC pulse. Conclusion: The current report demonstrates that a single REAC-BSP is sufficient to modulate brain activity in awake subjects, able to be measured using fMRI. These initial results open new perspectives into the understanding of the effects of weak and brief radio pulses upon brain activity, and provide the basis for further indepth studies using REAC-BSP and fMRI. Keywords: fMRI, brain stimulation, brain modulation, REAC, neuropsychiatric treatments

  1. VEGF-mediated angiogenesis stimulates neural stem cell proliferation and differentiation in the premature brain

    International Nuclear Information System (INIS)

    This study investigated the effects of angiogenesis on the proliferation and differentiation of neural stem cells in the premature brain. We observed the changes in neurogenesis that followed the stimulation and inhibition of angiogenesis by altering vascular endothelial growth factor (VEGF) expression in a 3-day-old rat model. VEGF expression was overexpressed by adenovirus transfection and down-regulated by siRNA interference. Using immunofluorescence assays, Western blot analysis, and real-time PCR methods, we observed angiogenesis and the proliferation and differentiation of neural stem cells. Immunofluorescence assays showed that the number of vWF-positive areas peaked at day 7, and they were highest in the VEGF up-regulation group and lowest in the VEGF down-regulation group at every time point. The number of neural stem cells, neurons, astrocytes, and oligodendrocytes in the subventricular zone gradually increased over time in the VEGF up-regulation group. Among the three groups, the number of these cells was highest in the VEGF up-regulation group and lowest in the VEGF down-regulation group at the same time point. Western blot analysis and real-time PCR confirmed these results. These data suggest that angiogenesis may stimulate the proliferation of neural stem cells and differentiation into neurons, astrocytes, and oligodendrocytes in the premature brain.

  2. Deep brain stimulation of the ventral striatum increases BDNF in the fear extinction circuit

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    Fabricio H Do-Monte

    2013-08-01

    Full Text Available Deep brain stimulation (DBS of the ventral capsule/ventral striatum (VC/VS reduces the symptoms of treatment-resistant obsessive compulsive disorder (OCD, and improves response to extinction-based therapies. We recently reported that DBS-like stimulation of a rat homologue of VC/VS, the dorsal-VS, reduced conditioned fear and enhanced extinction memory (Rodriguez-Romaguera et al, 2012. In contrast, DBS of the ventral-VS had the opposite effects. To examine possible mechanisms, we assessed the effects of VS DBS on the expression of the neural activity marker Fos and brain-derived neurotrophic factor (BDNF, a key mediator of extinction plasticity in prefrontal-amygdala circuits. Consistent with decreased fear expression, DBS of dorsal-VS increased Fos expression in prelimbic and infralimbic prefrontal cortices and in the lateral division of the central nucleus of amygdala, an area that inhibits amygdala output. Consistent with improved extinction memory, we found that DBS of dorsal-VS, but not ventral-VS, increased neuronal BDNF expression in prelimbic and infralimbic prefrontal cortices. These rodent findings are consistent with the idea that clinical DBS of VC/VS may augment fear extinction through an increase in BDNF expression.

  3. Deep brain stimulation of the ventral striatum increases BDNF in the fear extinction circuit.

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    Do-Monte, Fabricio H; Rodriguez-Romaguera, Jose; Rosas-Vidal, Luis E; Quirk, Gregory J

    2013-01-01

    Deep brain stimulation (DBS) of the ventral capsule/ventral striatum (VC/VS) reduces the symptoms of treatment-resistant obsessive compulsive disorder (OCD), and improves response to extinction-based therapies. We recently reported that DBS-like stimulation of a rat homologue of VC/VS, the dorsal-VS, reduced conditioned fear and enhanced extinction memory (Rodriguez-Romaguera et al., 2012). In contrast, DBS of the ventral-VS had the opposite effects. To examine possible mechanisms of these effects, we assessed the effects of VS DBS on the expression of the neural activity marker Fos and brain-derived neurotrophic factor (BDNF), a key mediator of extinction plasticity in prefrontal-amygdala circuits. Consistent with decreased fear expression, DBS of dorsal-VS increased Fos expression in prelimbic and infralimbic prefrontal cortices and in the lateral division of the central nucleus of amygdala, an area that inhibits amygdala output. Consistent with improved extinction memory, we found that DBS of dorsal-VS, but not ventral-VS, increased neuronal BDNF expression in prelimbic and infralimbic prefrontal cortices. These rodent findings are consistent with the idea that clinical DBS of VC/VS may augment fear extinction through an increase in BDNF expression. PMID:23964215

  4. Fatigue in multiple sclerosis: neural correlates and the role of non-invasive brain stimulation

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    Moussa A. Chalah

    2015-11-01

    Full Text Available Multiple sclerosis (MS is a chronic progressive inflammatory disease of the central nervous system and the major cause of non-traumatic disability in young adults. Fatigue is a frequent symptom reported by the majority of MS patients during their disease course and drastically af-fects their quality of life. Despite its significant prevalence and impact, the underlying patho-physiological mechanisms are not well elucidated. MS fatigue is still considered the result of multifactorial and complex constellations, and is commonly classified into primary fatigue related to the pathological changes of the disease itself, and secondary fatigue attributed to mimicking symptoms, comorbid sleep and mood disorders, and medications side effects. Data from neuroimaging, neurophysiology, neuroendocrine and neuroimmune studies have raised hypotheses regarding the origin of this symptom, some of which have succeeded in identifying an association between MS fatigue and structural or functional abnormalities within various brain networks. Hence, the aim of this work is to reappraise the neural correlates of MS fatigue and to discuss the rationale for the emergent use of noninvasive brain stimulation (NIBS techniques as potential treatments. This will include a presentation of the various NIBS modalities and a proposition of their potential mechanisms of action in this context. Specific issues related to the value of transcranial direct current stimulation will be addressed.

  5. Deep brain stimulation or thalamotomy in fragile X-associated tremor/ataxia syndrome? Case report.

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    Tamás, Gertrúd; Kovács, Norbert; Varga, Noémi Ágnes; Barsi, Péter; Erőss, Loránd; Molnár, Mária Judit; Balás, István

    2016-01-01

    We present the case of a 66-year-old man who has been treated for essential tremor since the age of 58. He developed mild cerebellar gait ataxia seven years after tremor onset. Moderate, global brain atrophy was identified on MRI scans. At the age of 68, only temporary tremor relief could be achieved by bilateral deep brain stimulation of the ventral intermedius nucleus of the thalamus. Bilateral stimulation of the subthalamic nucleus also resulted only in transient improvement. In the meantime, progressive gait ataxia and tetraataxia developed accompanied by other cerebellar symptoms, such as nystagmus and scanning speech. These correlated with progressive development of bilateral symmetric hyperintensity of the middle cerebellar peduncles on T2 weighted MRI scans. Genetic testing revealed premutation of the FMR1 gene, establishing the diagnosis of fragile X-associated tremor/ataxia syndrome. Although this is a rare disorder, it should be taken into consideration during preoperative evaluation of essential tremor. Postural tremor ceased two years later after thalamotomy on the left side, while kinetic tremor of the right hand also improved. PMID:27375149

  6. VEGF-mediated angiogenesis stimulates neural stem cell proliferation and differentiation in the premature brain

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    Sun, Jinqiao, E-mail: jinqiao1977@163.com [Institute of Pediatrics, Children' s Hospital of Fudan University (China); Sha, Bin [Department of Neonatology, Children' s Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102 (China); Zhou, Wenhao, E-mail: zhou_wenhao@yahoo.com.cn [Department of Neonatology, Children' s Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102 (China); Yang, Yi [Institute of Pediatrics, Children' s Hospital of Fudan University (China)

    2010-03-26

    This study investigated the effects of angiogenesis on the proliferation and differentiation of neural stem cells in the premature brain. We observed the changes in neurogenesis that followed the stimulation and inhibition of angiogenesis by altering vascular endothelial growth factor (VEGF) expression in a 3-day-old rat model. VEGF expression was overexpressed by adenovirus transfection and down-regulated by siRNA interference. Using immunofluorescence assays, Western blot analysis, and real-time PCR methods, we observed angiogenesis and the proliferation and differentiation of neural stem cells. Immunofluorescence assays showed that the number of vWF-positive areas peaked at day 7, and they were highest in the VEGF up-regulation group and lowest in the VEGF down-regulation group at every time point. The number of neural stem cells, neurons, astrocytes, and oligodendrocytes in the subventricular zone gradually increased over time in the VEGF up-regulation group. Among the three groups, the number of these cells was highest in the VEGF up-regulation group and lowest in the VEGF down-regulation group at the same time point. Western blot analysis and real-time PCR confirmed these results. These data suggest that angiogenesis may stimulate the proliferation of neural stem cells and differentiation into neurons, astrocytes, and oligodendrocytes in the premature brain.

  7. Different Mode of Afferents Determines the Frequency Range of High Frequency Activities in the Human Brain: Direct Electrocorticographic Comparison between Peripheral Nerve and Direct Cortical Stimulation.

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    Katsuya Kobayashi

    Full Text Available Physiological high frequency activities (HFA are related to various brain functions. Factors, however, regulating its frequency have not been well elucidated in humans. To validate the hypothesis that different propagation modes (thalamo-cortical vs. cortico-coritcal projections, or different terminal layers (layer IV vs. layer II/III affect its frequency, we, in the primary somatosensory cortex (SI, compared HFAs induced by median nerve stimulation with those induced by electrical stimulation of the cortex connecting to SI. We employed 6 patients who underwent chronic subdural electrode implantation for presurgical evaluation. We evaluated the HFA power values in reference to the baseline overriding N20 (earliest cortical response and N80 (late response of somatosensory evoked potentials (HFA(SEP(N20 and HFA(SEP(N80 and compared those overriding N1 and N2 (first and second responses of cortico-cortical evoked potentials (HFA(CCEP(N1 and HFA(CCEP(N2. HFA(SEP(N20 showed the power peak in the frequency above 200 Hz, while HFA(CCEP(N1 had its power peak in the frequency below 200 Hz. Different propagation modes and/or different terminal layers seemed to determine HFA frequency. Since HFA(CCEP(N1 and HFA induced during various brain functions share a similar broadband profile of the power spectrum, cortico-coritcal horizontal propagation seems to represent common mode of neural transmission for processing these functions.

  8. Deep brain stimulation modulates synchrony within spatially and spectrally distinct resting state networks in Parkinson’s disease

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    Oswal, Ashwini; Beudel, Martijn; Zrinzo, Ludvic; Limousin, Patricia; Hariz, Marwan; Foltynie, Tom; Litvak, Vladimir

    2016-01-01

    Chronic dopamine depletion in Parkinson’s disease leads to progressive motor and cognitive impairment, which is associated with the emergence of characteristic patterns of synchronous oscillatory activity within cortico-basal-ganglia circuits. Deep brain stimulation of the subthalamic nucleus is an effective treatment for Parkinson’s disease, but its influence on synchronous activity in cortico-basal-ganglia loops remains to be fully characterized. Here, we demonstrate that deep brain stimulation selectively suppresses certain spatially and spectrally segregated resting state subthalamic nucleus–cortical networks. To this end we used a validated and novel approach for performing simultaneous recordings of the subthalamic nucleus and cortex using magnetoencephalography (during concurrent subthalamic nucleus deep brain stimulation). Our results highlight that clinically effective subthalamic nucleus deep brain stimulation suppresses synchrony locally within the subthalamic nucleus in the low beta oscillatory range and furthermore that the degree of this suppression correlates with clinical motor improvement. Moreover, deep brain stimulation relatively selectively suppressed synchronization of activity between the subthalamic nucleus and mesial premotor regions, including the supplementary motor areas. These mesial premotor regions were predominantly coupled to the subthalamic nucleus in the high beta frequency range, but the degree of deep brain stimulation-associated suppression in their coupling to the subthalamic nucleus was not found to correlate with motor improvement. Beta band coupling between the subthalamic nucleus and lateral motor areas was not influenced by deep brain stimulation. Motor cortical coupling with subthalamic nucleus predominantly involved driving of the subthalamic nucleus, with those drives in the higher beta frequency band having much shorter net delays to subthalamic nucleus than those in the lower beta band. These observations raise

  9. Resuscitation therapy for traumatic brain injury-induced coma in rats:mechanisms of median nerve electrical stimulation

    Institute of Scientific and Technical Information of China (English)

    Zhen Feng; Ying-jun Zhong; Liang Wang; Tian-qi Wei

    2015-01-01

    In this study, rats were put into traumatic brain injury-induced coma and treated with median nerve electrical stimulation. We explored the wake-promoting effect, and possible mechanisms, of median nerve electrical stimulation. Electrical stimulation upregulated the expression levels of orexin-A and its receptor OX1R in the rat prefrontal cortex. Orexin-A expression gradually in-creased with increasing stimulation, while OX1R expression reached a peak at 12 hours and then decreased. In addition, after the OX1R antagonist, SB334867, was injected into the brain of rats after traumatic brain injury, fewer rats were restored to consciousness, and orexin-A and OXIR expression in the prefrontal cortex was downregulated. Our ifndings indicate that median nerve electrical stimulation induced an up-regulation of orexin-A and OX1R expression in the pre-frontal cortex of traumatic brain injury-induced coma rats, which may be a potential mechanism involved in the wake-promoting effects of median nerve electrical stimulation.

  10. Resuscitation therapy for traumatic brain injury-induced coma in rats: mechanisms of median nerve electrical stimulation

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    Zhen Feng

    2015-01-01

    Full Text Available In this study, rats were put into traumatic brain injury-induced coma and treated with median nerve electrical stimulation. We explored the wake-promoting effect, and possible mechanisms, of median nerve electrical stimulation. Electrical stimulation upregulated the expression levels of orexin-A and its receptor OX1R in the rat prefrontal cortex. Orexin-A expression gradually increased with increasing stimulation, while OX1R expression reached a peak at 12 hours and then decreased. In addition, after the OX1R antagonist, SB334867, was injected into the brain of rats after traumatic brain injury, fewer rats were restored to consciousness, and orexin-A and OXIR expression in the prefrontal cortex was downregulated. Our findings indicate that median nerve electrical stimulation induced an up-regulation of orexin-A and OX1R expression in the prefrontal cortex of traumatic brain injury-induced coma rats, which may be a potential mechanism involved in the wake-promoting effects of median nerve electrical stimulation.

  11. Brain SPECT guided repetitive transcranial magnetic stimulation (rTMS) in treatment resistant major depressive disorder.

    Science.gov (United States)

    Jha, Shailesh; Chadda, Rakesh K; Kumar, Nand; Bal, C S

    2016-06-01

    Repetitive transcranial magnetic stimulation (rTMS) has emerged as a potential treatment in treatment resistant major depressive disorder (MDD). However, there is no consensus about the exact site of stimulation for rTMS. Single-photon emission computed tomography (SPECT) offers a potential technique in deciding the site of stimulation. The present study was conducted to assess the difference in outcome of brain SPECT assisted rTMS versus standard protocol of twenty sessions of high frequency rTMS as add on treatment in 20 patients with treatment resistant MDD, given over a period of 4 weeks. Thirteen subjects (group I) received high frequency rTMS over an area of hypoperfusion in the prefrontal cortex, as identified on SPECT, whereas 7 subjects (group II) were administered rTMS in the left dorsoslateral prefrontal cortex (DLPFC) area. Improvement was monitored using standardized instruments. Patients in the group I showed a significantly better response compared to those in the group II. In group I, 46% of the subjects were responders on MADRS, 38% on BDI and 77% on CGI. The parallel figures of responders in Group II were 0% on MADRS, 14% on BDI and 43% on CGI. There were no remitters in the study. No significant untoward side effects were noticed. The study had limitations of a small sample size and non-controlled design, and all the subjects were also receiving the standard antidepressant therapy. Administration of rTMS over brain SPECT specified area of hypoperfusion may have a better clinical outcome compared to the standard protocol. PMID:27208445

  12. Effects of STN and GPi deep brain stimulation on impulse control disorders and dopamine dysregulation syndrome.

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    Sarah J Moum

    Full Text Available OBJECTIVE: Impulse control disorders (ICDs and dopamine dysregulation syndrome (DDS are important behavioral problems that affect a subpopulation of patients with Parkinson's disease (PD and typically result in markedly diminished quality of life for patients and their caregivers. We aimed to investigate the effects of subthalamic nucleus (STN and internal globus pallidus (GPi deep brain stimulation (DBS on ICD/DDS frequency and dopaminergic medication usage. METHODS: A retrospective chart review was performed on 159 individuals who underwent unilateral or bilateral PD DBS surgery in either STN or GPi. According to published criteria, pre- and post-operative records were reviewed to categorize patients both pre- and post-operatively as having ICD, DDS, both ICD and DDS, or neither ICD nor DDS. Group differences in patient demographics, clinical presentations, levodopa equivalent dose (LED, and change in diagnosis following unilateral/bilateral by brain target (STN or GPi DBS placement were examined. RESULTS: 28 patients met diagnostic criteria for ICD or DDS pre- or post-operatively. ICD or DDS classification did not differ by GPi or STN target stimulation. There was no change in DDS diagnosis after unilateral or bilateral stimulation. For ICD, diagnosis resolved in 2 of 7 individuals after unilateral or bilateral DBS. Post-operative development of these syndromes was significant; 17 patients developed ICD diagnoses post-operatively with 2 patients with pre-operative ICD developing DDS post-operatively. CONCLUSIONS: Unilateral or bilateral DBS did not significantly treat DDS or ICD in our sample, even though a few cases of ICD resolved post-operatively. Rather, our study provides preliminary evidence that DDS and ICD diagnoses may emerge following DBS surgery.

  13. Stimulation of the sphenopalatine ganglion induces reperfusion and blood-brain barrier protection in the photothrombotic stroke model.

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    Haviv Levi

    Full Text Available PURPOSE: The treatment of stroke remains a challenge. Animal studies showing that electrical stimulation of the sphenopalatine ganglion (SPG exerts beneficial effects in the treatment of stroke have led to the initiation of clinical studies. However, the detailed effects of SPG stimulation on the injured brain are not known. METHODS: The effect of acute SPG stimulation was studied by direct vascular imaging, fluorescent angiography and laser Doppler flowmetry in the sensory motor cortex of the anaesthetized rat. Focal cerebral ischemia was induced by the rose bengal (RB photothrombosis method. In chronic experiments, SPG stimulation, starting 15 min or 24 h after photothrombosis, was given for 3 h per day on four consecutive days. Structural damage was assessed using histological and immunohistochemical methods. Cortical functions were assessed by quantitative analysis of epidural electro-corticographic (ECoG activity continuously recorded in behaving animals. RESULTS: Stimulation induced intensity- and duration-dependent vasodilation and increased cerebral blood flow in both healthy and photothrombotic brains. In SPG-stimulated rats both blood brain-barrier (BBB opening, pathological brain activity and lesion volume were attenuated compared to untreated stroke animals, with no apparent difference in the glial response surrounding the necrotic lesion. CONCLUSION: SPG-stimulation in rats induces vasodilation of cortical arterioles, partial reperfusion of the ischemic lesion, and normalization of brain functions with reduced BBB dysfunction and stroke volume. These findings support the potential therapeutic effect of SPG stimulation in focal cerebral ischemia even when applied 24 h after stroke onset and thus may extend the therapeutic window of currently administered stroke medications.

  14. Non-invasive brain stimulation for the treatment of brain diseases in childhood and adolescence: state of the art, current limits and future challenges

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    Carmelo Mario Vicario

    2013-11-01

    Full Text Available In the last decades interest in application of non-invasive brain stimulation for enhancing neural functions is growing continuously. However, the use of such techniques in pediatric populations remains rather limited and mainly confined to the treatment of severe neurological and psychiatric diseases. In this article we provide a complete review of non-invasive brain stimulation studies conducted in pediatric populations. We also provide a brief discussion about the current limitations and future directions in a field of research still very young and full of issues to be explored.

  15. Selective sensation based brain-computer interface via mechanical vibrotactile stimulation.

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    Lin Yao

    Full Text Available In this work, mechanical vibrotactile stimulation was applied to subjects' left and right wrist skins with equal intensity, and a selective sensation perception task was performed to achieve two types of selections similar to motor imagery Brain-Computer Interface. The proposed system was based on event-related desynchronization/synchronization (ERD/ERS, which had a correlation with processing of afferent inflow in human somatosensory system, and attentional effect which modulated the ERD/ERS. The experiments were carried out on nine subjects (without experience in selective sensation, and six of them showed a discrimination accuracy above 80%, three of them above 95%. Comparative experiments with motor imagery (with and without presence of stimulation were also carried out, which further showed the feasibility of selective sensation as an alternative BCI task complementary to motor imagery. Specifically there was significant improvement ([Formula: see text] from near 65% in motor imagery (with and without presence of stimulation to above 80% in selective sensation on some subjects. The proposed BCI modality might well cooperate with existing BCI modalities in the literature in enlarging the widespread usage of BCI system.

  16. Modeling and automatic feedback control of tremor: adaptive estimation of deep brain stimulation.

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    Muhammad Rehan

    Full Text Available This paper discusses modeling and automatic feedback control of (postural and rest tremor for adaptive-control-methodology-based estimation of deep brain stimulation (DBS parameters. The simplest linear oscillator-based tremor model, between stimulation amplitude and tremor, is investigated by utilizing input-output knowledge. Further, a nonlinear generalization of the oscillator-based tremor model, useful for derivation of a control strategy involving incorporation of parametric-bound knowledge, is provided. Using the Lyapunov method, a robust adaptive output feedback control law, based on measurement of the tremor signal from the fingers of a patient, is formulated to estimate the stimulation amplitude required to control the tremor. By means of the proposed control strategy, an algorithm is developed for estimation of DBS parameters such as amplitude, frequency and pulse width, which provides a framework for development of an automatic clinical device for control of motor symptoms. The DBS parameter estimation results for the proposed control scheme are verified through numerical simulations.

  17. Nonmotor Symptoms and Subthalamic Deep Brain Stimulation in Parkinson’s Disease

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    Han-Joon Kim

    2015-05-01

    Full Text Available Subthalamic deep brain stimulation (STN DBS is an established treatment for the motor symptoms in patients with advanced Parkinson’s disease (PD. In addition to improvements in motor symptoms, many studies have reported changes in various nonmotor symptoms (NMSs after STN DBS in patients with PD. Psychiatric symptoms, including depression, apathy, anxiety, and impulsivity, can worsen or improve depending on the electrical stimulation parameters, the locations of the stimulating contacts within the STN, and changes in medications after surgery. Global cognitive function is not affected by STN DBS, and there is no increase in the incidence of dementia after STN DBS compared to that after medical treatment, although clinically insignificant declines in verbal fluency have been consistently reported. Pain, especially PD-related pain, improves with STN DBS. Evidence regarding the effects of STN DBS on autonomic symptoms and sleep-related problems is limited and remains conflicting. Many symptoms of nonmotor fluctuations, which are occasionally more troublesome than motor fluctuations, improve with STN DBS. Although it is clear that NMSs are not target symptoms for STN DBS, NMSs have a strong influence on the quality of life of patients with PD, and clinicians should thus be aware of these NMSs when deciding whether to perform surgery and should pay attention to changes in these symptoms after STN DBS to ensure the optimal care for patients.

  18. Swallowing and deep brain stimulation in Parkinson's disease: a systematic review.

    Science.gov (United States)

    Troche, Michelle S; Brandimore, Alexandra E; Foote, Kelly D; Okun, Michael S

    2013-09-01

    The purpose of this review is to assess the current state of the literature on the topic of deep brain stimulation (DBS) and its effects on swallowing function in Parkinson's disease (PD). Pubmed, Cochrane review, and web of science searches were completed on all articles addressing DBS that contained a swallowing outcome measure. Outcome measures included the penetration/aspiration scale, pharyngeal transit time, oropharyngeal residue, drooling, aspiration pneumonia, death, hyolaryngeal excursion, epiglottic inversion, UPDRS scores, and presence of coughing/throat clearing during meals. The search identified 13 studies specifically addressing the effects of DBS on swallowing. Critical assessment of the 13 identified peer-reviewed publications revealed nine studies employing an experimental design, (e.g. "on" vs. "off", pre- vs. post-DBS) and four case reports. None of the nine experimental studies were found to identify clinically significant improvement or decline in swallowing function with DBS. Despite these findings, several common threads were identified across experimental studies and will be examined in this review. Additionally, available data demonstrate that, although subthalamic nucleus (STN) stimulation has been considered to cause more impairment to swallowing function than globus pallidus internus (GPi) stimulation, there are no experimental studies directly comparing swallowing function in STN vs. GPi. Moreover, there has been no comparison of unilateral vs. bilateral DBS surgery and the coincident effects on swallowing function. This review includes a critical analysis of all experimental studies and discusses methodological issues that should be addressed in future studies. PMID:23726461

  19. [The transition of deep brain stimulation from disease specific to symptom specific indications].

    Science.gov (United States)

    Okun, Michael S

    2012-01-01

    The success of chronic deep brain stimulation (DBS) and electrical neuro-network modulation (ENM) to address neurological and neuropsychiatric disorders has led the Food and Drug Administration (FDA), and also other worldwide regulatory agencies to grant approval for the use of DBS in specific disorders. In the United States, DBS is FDA approved for the treatment of advanced Parkinson's disease (PD), essential tremor (ET), obsessive compulsive disorder (OCD), and for dystonia. OCD and dystonia have been approved under a mechanism referred to as a humanitarian device exemption (HDE). However, as the field of DBS and ENM evolve there has been a shift in practice patterns from targeting diseases to targeting specific and disabling symptoms. This shift has been driving interdisciplinary DBS boards to collect, and to address symptom profiles in all potential DBS candidates. Based on a specific symptom profile, a strategic and personalized medicine approach can be undertaken. The personalized approach will take into consideration the brain target, a unilateral versus a bilateral procedure, and the potential for use of more than one DBS lead per brain hemisphere. Additionally, a personalized approach to DBS will also facilitate improved pre-operative medication adjustments, as well as optimal post-operative medication, behavioral, and device management. PMID:23196455

  20. Dopamine transporter imaging and the effects of deep brain stimulation in patients with Parkinson's disease

    International Nuclear Information System (INIS)

    Single-photon emission computed tomography (SPECT) with [123I]FP-CIT is a marker for loss of presynaptic dopamine transporters in the striatum in Parkinson's disease (PD). We used [123I]FP-CIT SPECT in order to evaluate binding to the dopamine transporter before and after neurosurgical treatment with bilateral stimulation in the subthalamic nucleus (STN). Thirty-five patients with levodopa-responsive PD were examined with [123I]FP-CIT SPECT pre-operatively (baseline scan: mean 3 months before surgery), and 3 and 12 months after surgery. Pre-operatively, all patients already had substantial signs of severe nigrostriatal neuronal loss as determined from the [123I]FP-CIT SPECT scans. One year after surgery the specific [123I]FP-CIT binding to the striatum was significantly reduced by 10.3% compared with the pre-operative baseline scan. The mean time span from the baseline scan before surgery to the follow-up scan 1 year after surgery was 16.2 months. Hence, the rate of reduction equals a mean annual reduction of 7.7%. A comparable control group of patients with PD who did not undergo surgery was also examined longitudinally. In this group the specific binding of [123I]FP-CIT was reduced by 6.7% per year. The specific binding of [123I]FP-CIT was reduced equally in the STN-stimulated patients and a group of non-operated PD patients with advanced disease. Our study does not support the notion that electrode implantation and STN stimulation exert a neuroprotective effect by themselves. (orig.)

  1. [Obsessive-compulsive disorder, a new model of basal ganglia dysfunction? Elements from deep brain stimulation studies].

    Science.gov (United States)

    Haynes, W I A; Millet, B; Mallet, L

    2012-01-01

    Deep brain stimulation was first developed for movement disorders but is now being offered as a therapeutic alternative in severe psychiatric disorders after the failure of conventional therapies. One of such pathologies is obsessive-compulsive disorder. This disorder which associates intrusive thoughts (obsessions) and repetitive irrepressible rituals (compulsions) is characterized by a dysfunction of a cortico-subcortical loop. After having reviewed the pathophysiological evidence to show why deep brain stimulation was an interesting path to take for severe and resistant cases of obsessive-compulsive disorder, we will present the results of the different clinical trials. Finally, we will provide possible mechanisms for the effects of deep brain stimulation in this pathology. PMID:22898561

  2. Disease-specific longevity of impulse generators in deep brain stimulation and review of the literature.

    Science.gov (United States)

    van Riesen, Christoph; Tsironis, Georg; Gruber, Doreen; Klostermann, Fabian; Krause, Patricia; Schneider, Gerd Helge; Kupsch, Andreas

    2016-06-01

    Deep brain stimulation (DBS) represents an established and internationally approved therapy for movement disorders. In the present retrospective analysis, we evaluated disease-specific longevity of dual channel impulse generators (IPG) used in different movement disorders. We correlated the battery lifetime with electrical stimulation settings, "total electrical energy delivered" (TEED), stimulation modi (monopolar, double monopolar and bipolar) and targets. Specifically, we reviewed the longevity and stimulation settings of 464 IPGs implanted between 1996 until 2011 in a single university center. Disease entities comprised Parkinson's disease (PD, n = 257), dystonia (n = 130) and essential tremor (ET, n = 50). Further subanalyses aimed at assessing differential longevity in different subtypes of PD and dystonia. The main finding relates to longer IPG longevity in ET (thalamic DBS) and PD (subthalamic DBS) vs. dystonia (pallidal DBS; 71.9 ± 6.7 vs. 51.5 ± 2.3 vs. 37 ± 2 months). In PD the tremor-dominant type was associated with a significant shorter battery survival than in the akinetic-rigid type without tremor or the "balanced" type with tremor, bradykinesia and rigidity (38.8 ± 3.9 vs. 53.6 ± 3.4 vs. 58.8 ± 4.1 months), while there were no significant differences in longevity between the subtypes of dystonia. Frequency, amplitude, pulse widths and TEED correlated inversely with battery lifetime. Pallidal DBS in dystonia is associated with a shorter lifetime of IPGs than subthalamic or thalamic DBS for PD or ET. The present results may contribute to the rapidly evolving refinement of DBS devices. Future studies that assess energy consumption both in patients with and without IPG replacement could help to avoid potential underestimation of longevity of IPGs. PMID:27198700

  3. Transcranial magnetic stimulation of the brain: guidelines for pain treatment research.

    Science.gov (United States)

    Klein, Max M; Treister, Roi; Raij, Tommi; Pascual-Leone, Alvaro; Park, Lawrence; Nurmikko, Turo; Lenz, Fred; Lefaucheur, Jean-Pascal; Lang, Magdalena; Hallett, Mark; Fox, Michael; Cudkowicz, Merit; Costello, Ann; Carr, Daniel B; Ayache, Samar S; Oaklander, Anne Louise

    2015-09-01

    Recognizing that electrically stimulating the motor cortex could relieve chronic pain sparked development of noninvasive technologies. In transcranial magnetic stimulation (TMS), electromagnetic coils held against the scalp influence underlying cortical firing. Multiday repetitive transcranial magnetic stimulation (rTMS) can induce long-lasting, potentially therapeutic brain plasticity. Nearby ferromagnetic or electronic implants are contraindications. Adverse effects are minimal, primarily headaches. Single provoked seizures are very rare. Transcranial magnetic stimulation devices are marketed for depression and migraine in the United States and for various indications elsewhere. Although multiple studies report that high-frequency rTMS of the motor cortex reduces neuropathic pain, their quality has been insufficient to support Food and Drug Administration application. Harvard's Radcliffe Institute therefore sponsored a workshop to solicit advice from experts in TMS, pain research, and clinical trials. They recommended that researchers standardize and document all TMS parameters and improve strategies for sham and double blinding. Subjects should have common well-characterized pain conditions amenable to motor cortex rTMS and studies should be adequately powered. They recommended standardized assessment tools (eg, NIH's PROMIS) plus validated condition-specific instruments and consensus-recommended metrics (eg, IMMPACT). Outcomes should include pain intensity and qualities, patient and clinician impression of change, and proportions achieving 30% and 50% pain relief. Secondary outcomes could include function, mood, sleep, and/or quality of life. Minimum required elements include sample sources, sizes, and demographics, recruitment methods, inclusion and exclusion criteria, baseline and posttreatment means and SD, adverse effects, safety concerns, discontinuations, and medication-usage records. Outcomes should be monitored for at least 3 months after initiation

  4. Theta, alpha and beta burst transcranial magnetic stimulation: brain modulation in tinnitus

    Directory of Open Access Journals (Sweden)

    Dirk De Ridder, Elsa van der Loo, Karolien Van der Kelen, Tomas Menovsky, Paul van de Heyning, Aage Moller

    2007-01-01

    Full Text Available Introduction: Some forms of tinnitus are considered to be auditory phantom phenomena related to reorganization and hyperactivity of the auditory central nervous system. Repetitive transcranial magnetic stimulation (rTMS is a non-invasive tool capable of modulating human brain activity, using single pulse or burst stimuli. Burst rTMS has only been performed in the theta range, and has not been used clinically. The authors analyze whether burst TMS at theta (5 Hz, alpha (10 Hz and beta (20 Hz frequencies can temporarily suppress narrow band noise/white noise tinnitus, which has been demonstrated to be intractable to tonic stimulation. Methods: rTMS is performed both in tonic and burst mode in 46 patients contralateral to the tinnitus side, at 5, 10 and 20 Hz. Fourteen placebo negative rTMS responders are further analyzed. Results: In 5 patients, maximal tinnitus suppression is obtained with theta, in 2 with alpha and in 7 with beta burst stimulation. Burst rTMS suppresses narrow band/white tinnitus much better than tonic rTMS t(13=6.4, p<.000. Women experience greater suppression of their tinnitus with burst stimulation than men, t(12=2.9, p<.05. Furthermore left sided tinnitus is perceived as more distressing on the TQ than right sided tinnitus, t(12=3.2, p<.01. The lower the tinnitus pitch the more effectively rTMS suppresses tinnitus(r=-0.65, p<0.05. Discussion: Burst rTMS can be used clinically, not only theta burst, but also alpha and beta burst. Burst rTMS is capable of suppressing narrow band/white noise tinnitus very much better than tonic rTMS. This could be due the simple fact that burst neuromodulation is more powerful than tonic neuromodulation or to a differential effect of burst and tonic stimulation on the lemniscal and extralemniscal auditory system. In some patients only alpha or beta burst rTMS is capable of suppressing tinnitus, and theta burst not. Therefore in future rTMS studies it could be worthwhile not to limit burst

  5. Biomarkers for Success: Using Neuroimaging to Predict Relapse and Develop Brain Stimulation Treatments for Cocaine-Dependent Individuals.

    Science.gov (United States)

    Hanlon, C A; Dowdle, L T; Jones, J L

    2016-01-01

    Cocaine dependence is one of the most difficult substance use disorders to treat. While the powerful effects of cocaine use on behavior were documented in the 19th century, it was not until the late 20th century that we realized cocaine use was affecting brain tissue and function. Following a brief introduction (Section 1), this chapter will summarize our current knowledge regarding alterations in neural circuit function typically observed in chronic cocaine users (Section 2) and highlight an emerging body of literature which suggests that pretreatment limbic circuit activity may be a reliable predictor of clinical outcomes among individuals seeking treatment for cocaine (Section 3). Finally, as the field of addiction research strives to translate this neuroimaging data into something clinically meaningful, we will highlight several new brain stimulation approaches which utilize functional brain imaging data to design noninvasive brain stimulation interventions for individuals seeking treatment for substance dependence disorders (Section 4). PMID:27503451

  6. Intraoperative functional MRI as a new approach to monitor deep brain stimulation in Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Hesselmann, Volker; Sorger, Bettina; Girnus, Ralf; Lasek, Kathrin; Schulte, Oliver; Krug, Barbara; Lackner, Klaus [Department of Radiology, University of Cologne, Joseph-Stelzmann-Strasse 9, 50924, Cologne (Germany); Maarouf, Mohammad; Sturm, Volker [Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Joseph-Stelzmann-Strasse 9, 50924, Cologne (Germany); Wedekind, Christoph [Department of Neurosurgery, University of Cologne, Joseph-Stelzmann-Strasse 9, 50924, Cologne (Germany); Bunke, Juergen [Philips Medical Systems, Hamburg (Germany)

    2004-04-01

    This article deals with technical aspects of intraoperative functional magnetic resonance imaging (fMRI) for monitoring the effect of deep brain stimulation (DBS) in a patient with Parkinson's disease. Under motor activation, therapeutic high-frequency stimulation of the subthalamic nucleus was accompanied by an activation decrease in the contralateral primary sensorimotor cortex and the ipsilateral cerebellum. Furthermore, an activation increase in the contralateral basal ganglia and insula region were detected. These findings demonstrate that fMRI constitutes a promising clinical application for investigating brain activity changes induced by DBS. (orig.)

  7. Refining language mapping by repetitive navigated transcranial magnetic stimulation in patients with left-sided perisylvian brain lesions

    OpenAIRE

    Ille, Sebastian

    2016-01-01

    The present thesis is based on two publications for which we performed language mapping in patients suffering from left-sided perisylvian brain lesions by repetitive navigated transcranial magnetic stimulation (rTMS), functional magnetic resonance imaging (fMRI), and direct cortical stimulation (DCS) during awake surgery. In summary, we ascertained that rTMS language mappings should be analyzed with specific thresholds in order to avoid false-positive results. Furthermore, we showed that b...

  8. Retrospective review of factors leading to dissatisfaction with subthalamic nucleus deep brain stimulation during long-term management

    OpenAIRE

    Farris, Sierra; Giroux, Monique

    2013-01-01

    Background: Subthalamic nucleus deep brain stimulation is effective in reducing motor symptoms in appropriately selected patients with Parkinson's disease. We identified factors that contribute to poor outcomes during early, middle and late stages of stimulation management in a series of patients that were referred for troubleshooting poor outcomes. Methods: We performed a retrospective review of 50 patients with bilateral STN DBS seen in our movement disorders clinic with unsatisfactory clin...

  9. A Three Spatial Dimension Wave Latent Force Model for Describing Excitation Sources and Electric Potentials Produced by Deep Brain Stimulation

    OpenAIRE

    Alvarado, Pablo A.; Álvarez, Mauricio A.; Orozco, Álvaro A.

    2016-01-01

    Deep brain stimulation (DBS) is a surgical treatment for Parkinson's Disease. Static models based on quasi-static approximation are common approaches for DBS modeling. While this simplification has been validated for bioelectric sources, its application to rapid stimulation pulses, which contain more high-frequency power, may not be appropriate, as DBS therapeutic results depend on stimulus parameters such as frequency and pulse width, which are related to time variations of the electric fiel...

  10. Comparing the Anticonvulsant Effects of Low Frequency Stimulation of Different Brain Sites on the Amygdala Kindling Acquisition in Rats

    OpenAIRE

    Esmaeilpour, Khadijeh; Masoumi-Ardakani, Yaser; Sheibani, Vahid; Shojaei, Amir; Harandi, Shaahin; Mirnajafi-Zadeh, Javad

    2013-01-01

    Low frequency stimulation (LFS) is a potential alternative therapy for epilepsy. However, it seems that the anticonvulsant effects of LFS depend on its target sites in the brain. Thus, the present study was designed to compare the anticonvulsant effects of LFS administered to amygdala, piriform cortex and substantia nigra on amygdala kindling acquisition. In control group, rats were kindled in a chronic manner (one stimulation per 24 h). In other experimental groups, animals received low-freq...

  11. The Sum of lts Parts-Effects of Gastric Distention, Nutrient Content and Sensory Stimulation on Brain Activation

    OpenAIRE

    Spetter, M.S.; Graaf, de, M.; de Mars, M; Viergever, M. A.; Smeets, P.A.M.

    2014-01-01

    During food consumption the brain integrates multiple interrelated neural and hormonal signals involved in the regulation of food intake. Factors influencing the decision to stop eating include the foods' sensory properties, macronutrient content, and volume, which in turn affect gastric distention and appetite hormone responses. So far, the contributions of gastric distention and oral stimulation by food on brain activation have not been studied. The primary objective of this study was to as...

  12. The Sum of Its Parts—Effects of Gastric Distention, Nutrient Content and Sensory Stimulation on Brain Activation

    OpenAIRE

    Spetter, Maartje S.; de Graaf, Cees; Mars, Monica; Viergever, Max A.; Smeets, Paul A. M.

    2014-01-01

    During food consumption the brain integrates multiple interrelated neural and hormonal signals involved in the regulation of food intake. Factors influencing the decision to stop eating include the foods' sensory properties, macronutrient content, and volume, which in turn affect gastric distention and appetite hormone responses. So far, the contributions of gastric distention and oral stimulation by food on brain activation have not been studied. The primary objective of this study was to as...

  13. Understanding deep brain stimulation in obsessive compulsive disorder: A preclinical study into the mechanism of action and behaviour

    OpenAIRE

    Dijk, van, G.

    2013-01-01

    We see a strong impact of deep brain stimulation (DBS) on several aspects of OCD (obsessive compulsive disorder). DBS in different brain areas affects compulsive behaviour, conditioned and unconditioned anxiety. DBS in the internal capsule (IC) shows the most promising behavioural results by uniquely reducing conditioned anxiety and by shortening the compulsive grooming bout in the sapap3 mutant mouse. This suggests that the IC is possibly the best target for DBS in relation to OCD. Further r...

  14. Upper-limb stroke rehabilitation using electrode-array based functional electrical stimulation with sensing and control innovations.

    Science.gov (United States)

    Kutlu, M; Freeman, C T; Hallewell, E; Hughes, A-M; Laila, D S

    2016-04-01

    Functional electrical stimulation (FES) has shown effectiveness in restoring upper-limb movement post-stroke when applied to assist participants' voluntary intention during repeated, motivating tasks. Recent clinical trials have used advanced controllers that precisely adjust FES to assist functional reach and grasp tasks with FES applied to three muscle groups, showing significant reduction in impairment. The system reported in this paper advances the state-of-the-art by: (1) integrating an FES electrode array on the forearm to assist complex hand and wrist gestures; (2) utilising non-contact depth cameras to accurately record the arm, hand and wrist position in 3D; and (3) employing an interactive touch table to present motivating virtual reality (VR) tasks. The system also uses iterative learning control (ILC), a model-based control strategy which adjusts the applied FES based on the tracking error recorded on previous task attempts. Feasibility of the system has been evaluated in experimental trials with 2 unimpaired participants and clinical trials with 4 hemiparetic, chronic stroke participants. The stroke participants attended 17, 1 hour training sessions in which they performed functional tasks, such as button pressing using the touch table and closing a drawer. Stroke participant results show that the joint angle error norm reduced by an average of 50.3% over 6 attempts at each task when assisted by FES. PMID:26947097

  15. Relationship between calcium entry and ACh release in K+ -stimulated rat brain synaptosomes

    International Nuclear Information System (INIS)

    This paper examines the pattern of Ca++ entry-dependent ACh release in relation to the kinetics of Ca++ entry, and its inactivation in rat brain synaptosomes exposed to 50 mM K0+ for short and prolonged durations. Intrasynaptosomal ACh was radiolabeled from tritium-choline in the presence of 20 um Paraoxon to inhibit the acetylcholinesterase activity. The release of tritium-ACh was studied in superfused synaptosomal beds formed on glass microfiber filters and by rapid filtration. The intermittent stimulation of superfused synaptosomal beds by 3-min pulses of 50 mM K+ evoked decremental output of tritium-ACh which reached nearly undetectable levels after the fifth stimulus

  16. Slow oscillation electrical brain stimulation during waking promotes EEG theta activity and memory encoding

    DEFF Research Database (Denmark)

    Kirov, Roumen; Weiss, Carsten; Siebner, Hartwig R;

    2009-01-01

    The application of transcranial slow oscillation stimulation (tSOS; 0.75 Hz) was previously shown to enhance widespread endogenous EEG slow oscillatory activity when applied during a sleep period characterized by emerging endogenous slow oscillatory activity. Processes of memory consolidation...... typically occurring during this state of sleep were also enhanced. Here, we show that the same tSOS applied in the waking brain also induced an increase in endogenous EEG slow oscillations (0.4-1.2 Hz), although in a topographically restricted fashion. Applied during wakefulness tSOS, additionally, resulted...... in a marked and widespread increase in EEG theta (4-8 Hz) activity. During wake, tSOS did not enhance consolidation of memories when applied after learning, but improved encoding of hippocampus-dependent memories when applied during learning. We conclude that the EEG frequency and related memory...

  17. Brain electric stimulation in treatment of epilepsy%神经电刺激技术在癫痫治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    杨辉

    2012-01-01

    The treatment of patients with refractory epilepsy has always been challenging. Despite the availability of multiple antiepileptic drugs, approximately 20% - 30% of patients continue to have seizures, and many are not candidates for epilepsy surgery. Currently available treatment options for these unfortunate patients are limited. Brain electric stimulation provides a nondestructive treatment for these patients. Studies of electrical stimulation of the brain in epilepsy treatment begin with the research on cerebellar stimulation. Until now, the potential targets have increased over the years, including cortex, cranial nerve and multiple brain nuclei. With the development of therapeutic brain devices for epilepsy, it is convinced that the brain electric stimulation will become more widely applied in treatment of epilepsy. This overview, combining with literatures and our experiences, briefly summarizes the application of brain electric stimulation in the treatment of epilepsy.

  18. Comparison of two treatments for coxarthrosis: local hyperthermia versus radio electric asymmetrical brain stimulation

    Directory of Open Access Journals (Sweden)

    Castagna A

    2011-07-01

    Full Text Available Alessandro Castagna1, Salvatore Rinaldi1,2, Vania Fontani1, Piero Mannu1, Matteo Lotti Margotti11Rinaldi Fontani Institute, Department of Neuro Psycho Physio Pathology, 2Medical School of Occupational Medicine, University of Florence, Florence, ItalyBackground: It is well known that psychological components are very important in the aging process and may also manifest in psychogenic movement disorders, such as coxarthrosis. This study analyzed the medical records of two similar groups of patients with coxarthrosis (n = 15 in each who were treated in two different clinics for rehabilitation therapy.Methods: Patients in Group A were treated with a course of traditional physiotherapy, including sessions of local hyperthermia. Group B patients were treated with only a course of radioelectric asymmetrical brain stimulation (REAC to improve their motor behavior.Results: Group A showed a significant decrease in symptoms of pain and stiffness, and an insignificant improvement in range of motion and muscle bulk. A single patient in this group developed worsened symptoms, and pain did not resolve completely in any patient. The patients in Group B had significantly decreased levels of pain and stiffness, and a significant improvement in range of motion and muscle bulk. No patients worsened in Group B, and the pain resolved completely in one patient.Conclusion: Both treatments were shown to be tolerable and safe. Patients who underwent REAC treatment appeared to have slightly better outcomes, with an appreciable improvement in both their physical and mental states. These aspects are particularly important in the elderly, in whom functional limitation is often associated with or exacerbated by a psychogenic component.Keywords: coxarthrosis, anti-aging, motor behavior, radioelectric asymmetric brain stimulation

  19. Deep brain stimulation versus anterior capsulotomy for obsessive-compulsive disorder: a review of the literature.

    Science.gov (United States)

    Pepper, Joshua; Hariz, Marwan; Zrinzo, Ludvic

    2015-05-01

    Obsessive-compulsive disorder (OCD) is a chronic and debilitating psychiatric condition. Traditionally, anterior capsulotomy (AC) was an established procedure for treatment of patients with refractory OCD. Over recent decades, deep brain stimulation (DBS) has gained popularity. In this paper the authors review the published literature and compare the outcome of AC and DBS targeting of the area of the ventral capsule/ventral striatum (VC/VS) and nucleus accumbens (NAcc). Patients in published cases were grouped according to whether they received AC or DBS and according to their preoperative scores on the Yale-Brown Obsessive-Compulsive Scale (YBOCS), and then separated according to outcome measures: remission (YBOCS score DBS of the VC/VS or the NAcc (mean age 38 years, follow-up 19 months, baseline YBOCS score of 33), and 108 patients underwent AC (mean age 36 years, follow-up 61 months, baseline YBOCS score of 30). In patients treated with DBS there was a 40% decrease in YBOCS score, compared with a 51% decrease for those who underwent AC (p = 0.004). Patients who underwent AC were 9% more likely to go into remission than patients treated with DBS (p = 0.02). No difference in complication rates was noted. Anterior capsulotomy is an efficient procedure for refractory OCD. Deep brain stimulation in the VC/VS and NAcc area is an emerging and promising therapy. The current popularity of DBS over ablative surgery for OCD is not due to nonefficacy of AC, but possibly because DBS is perceived as more acceptable by clinicians and patients. PMID:25635480

  20. Cognitive effects of deep brain stimulation in patients with obsessive–compulsive disorder

    Science.gov (United States)

    Mantione, Mariska; Nieman, Dorien; Figee, Martijn; van den Munckhof, Pepijn; Schuurman, Rick; Denys, Damiaan

    2015-01-01

    Background Deep brain stimulation (DBS) is a promising treatment for treatment-refractory obsessive–compulsive disorder (OCD). However, the effects of DBS on cognitive functioning remain unclear. Therefore, we aimed to assess cognitive safety of DBS for treatment-refractory OCD and the association between clinical changes and cognitive functioning. Methods Patients with treatment-refractory OCD treated with DBS targeted at the nucleus accumbens (NAcc) were compared with a control group of 14 patients with treatment-refractory OCD treated with care as usual. We assessed cognitive functioning at baseline, 3 weeks postoperatively and following 8 months of DBS. We compared change in clinical symptoms with cognitive changes. Results There were 16 patients in the DBS group and 14 patients in the control group. Three weeks postoperatively, the DBS group showed a significantly reduced performance on measures of visual organization and verbal fluency and a trend toward reduced performance on measures of visual memory and abstract reasoning. Cognitive functioning was found to be stable on all other measures. After 8 months of DBS, reduced performances persisted, except for a significant improvement in verbal fluency. Cognitive functioning in all other domains remained unaffected. We found no correlation between improvement of clinical symptoms and cognitive changes. Limitations A limitation of this study was its relatively small sample size. Conclusion Deep brain stimulation targeted at the NAcc may be considered a safe method in terms of cognition because cognitive functioning was unaffected on most neuropsychological measures. Nevertheless, we observed some minor reduced performance on specific measures of executive functioning that were possibly associated with surgical intervention. Our results suggest that severity of OCD symptoms is independent of cognitive functioning. PMID:26107159

  1. Deep brain stimulation as a treatment for Parkinson's disease related camptocormia.

    Science.gov (United States)

    Chieng, Lee Onn; Madhavan, Karthik; Wang, Michael Y

    2015-10-01

    In this systematic review, we aimed to profile the various reported interventions for camptocormia in Parkinson's disease (PD) and give an overview of the benefits of deep brain stimulation (DBS). Currently, there is no consensus in the literature regarding this. PD manifests in several ways and camptocormia is one of the commonly encountered problems for both spine and functional neurosurgeons. It is a significant forward flexion of the thoracolumbar spine which resolves in the recumbent position. DBS was introduced in 2002 in the USA, and since then its efficacy and applications have tremendously increased. We reviewed the PubMed and Medical Subject Headings database using the phrases "Parkinson's disease" or "Parkinson" in combination with "spinal deformity" or "camptocormia" or "bent spine syndrome" and "deep brain stimulation". Our review was limited to English language literature and we excluded camptocormia of non-PD origin. Our search yielded 361 articles with 131 patients in the pooled data. The majority (59%) of patients were women and the age range was 48-76 years. While half the patients on levodopa (n=42) saw no improvement of their camptocormia, 71% of the lidocaine group (n=27) and 68% of the DBS group (n=32) showed significant improvement. For mean flexion angle, the spinal surgery and DBS group demonstrated profound improvement in the bending angle, 89.9% and 78.2%, respectively. However, major complications following spinal surgery were noted. Although the results are from a small group of patients, DBS has achieved sustained improvement in camptocormia with low postoperative morbidity, and appears to be a promising treatment option. A larger, long term study is necessary to establish comprehensive outcome data. PMID:26321306

  2. Tuning and disrupting the brain – modulating the McGurk illusion with electrical stimulation

    Directory of Open Access Journals (Sweden)

    Lotfi B Merabet

    2014-08-01

    Full Text Available In the so-called McGurk illusion, when the synchronized presentation of the visual stimulus /ga/ is paired with the auditory stimulus /ba/, people in general hear it as /da/. Multisensory integration processing underlying this illusion seems to occur within the Superior Temporal Sulcus (STS. Herein, we present evidence demonstrating that bilateral cathodal transcranial direct current stimulation (tDCS of this area can decrease the McGurk illusion-type responses. Additionally, we show that the manipulation of this audio-visual integrated output occurs irrespective of the number of eye-fixations on the mouth of the speaker. Bilateral anodal tDCS of the Parietal Cortex also modulates the illusion, but in the opposite manner, inducing more illusion-type responses. This is the first demonstration of using non-invasive brain stimulation to modulate multisensory speech perception in an illusory context (i.e., both increasing and decreasing illusion-type responses to a verbal audio-visual integration task. These findings provide clear evidence that both the superior temporal and parietal areas contribute to multisensory integration processing related to speech perception. Specifically, STS seems fundamental for the temporal synchronization and integration of auditory and visual inputs. For its part, PPC may adjust the arrival of incoming audio and visual information to STS thereby enhancing their interaction in this latter area.

  3. Deep brain stimulation for obsessive-compulsive disorder is associated with cortisol changes.

    Science.gov (United States)

    de Koning, Pelle P; Figee, Martijn; Endert, Erik; Storosum, Jitschak G; Fliers, Eric; Denys, Damiaan

    2013-08-01

    Deep brain stimulation (DBS) is an effective treatment for obsessive-compulsive disorder (OCD), but its mechanism of action is largely unknown. Since DBS may induce rapid symptomatic changes and the pathophysiology of OCD has been linked to the hypothalamic-pituitary-adrenal (HPA) axis, we set out to study whether DBS affects the HPA axis in OCD patients. We compared a stimulation ON and OFF condition with a one-week interval in 16 therapy-refractory OCD patients, treated with DBS for at least one year, targeted at the nucleus accumbens (NAc). We measured changes in 24-h urinary excretion of free cortisol (UFC), adrenaline and noradrenaline and changes in obsessive-compulsive (Y-BOCS), depressive (HAM-D) and anxiety (HAM-A) symptom scores. Median UFC levels increased with 53% in the OFF condition (from 93 to 143nmol/24h, p=0.12). There were no changes in urinary adrenaline or noradrenaline excretion. The increase in Y-BOCS (39%), and HAM-D (78%) scores correlated strongly with increased UFC levels in the OFF condition. Our findings indicate that symptom changes following DBS for OCD patients are associated with changes in UFC levels. PMID:23333254

  4. Astroglial Control of the Antidepressant-Like Effects of Prefrontal Cortex Deep Brain Stimulation

    Directory of Open Access Journals (Sweden)

    A. Etiévant

    2015-08-01

    Full Text Available Although deep brain stimulation (DBS shows promising efficacy as a therapy for intractable depression, the neurobiological bases underlying its therapeutic action remain largely unknown. The present study was aimed at characterizing the effects of infralimbic prefrontal cortex (IL-PFC DBS on several pre-clinical markers of the antidepressant-like response and at investigating putative non-neuronal mechanism underlying DBS action. We found that DBS induced an antidepressant-like response that was prevented by IL-PFC neuronal lesion and by adenosine A1 receptor antagonists including caffeine. Moreover, high frequency DBS induced a rapid increase of hippocampal mitosis and reversed the effects of stress on hippocampal synaptic metaplasticity. In addition, DBS increased spontaneous IL-PFC low-frequency oscillations and both raphe 5-HT firing activity and synaptogenesis. Unambiguously, a local glial lesion counteracted all these neurobiological effects of DBS. Further in vivo electrophysiological results revealed that this astrocytic modulation of DBS involved adenosine A1 receptors and K+ buffering system. Finally, a glial lesion within the site of stimulation failed to counteract the beneficial effects of low frequency (30 Hz DBS. It is proposed that an unaltered neuronal–glial system constitutes a major prerequisite to optimize antidepressant DBS efficacy. It is also suggested that decreasing frequency could heighten antidepressant response of partial responders.

  5. Treatment for Traumatic Brain Injury in Mice Using Transcranial Magnetic Stimulation: A Preliminary Study

    Science.gov (United States)

    Carr, Alexandria; Zenitsky, Gary; Crowther, Lawrence; Hadimani, Ravi; Anantharam, Vellareddy; Kanthasamy, Anumantha; Jiles, David

    2014-03-01

    Transcranial magnetic stimulation (TMS) is a non-invasive surgery-free tool used to stimulate the brain by time-varying magnetic fields. TMS is currently being investigated as a treatment for neurological disorders such as depression, Parkinson's disease and TBI. Before moving to human TMS/TBI trials, animal testing should be pursued to determine suitability and adverse effects. As an initial study, four healthy mice were treated with TMS at different power levels to determine short-term behavioral effects and set a control group baseline. The mouse's behavior was studied using the Rotorod test, which measures the animal's latency to fall off a rotating rod, and the Versamax test, which measures horizontal and vertical movement, and total distance traveled. The Rotorod test has shown for TMS power levels >=90% the mice begin to fall directly post-treatment. Similarly, the Versamax test has shown for power levels >=80% the mice are less mobile directly post-treatment. Versamax mobility was found to return to normal the day following treatment. These mice were housed in the facility for 4 months and the behavioral tests were repeated. Versamax results showed there was no significant variation in mobility indicating there are no long-term side effects of TMS treatment on the mice. This work was supported by the Barbara and James Palmer Endowment and the Carver Charitable Trust at the Department of Electrical and Computer Engineering, Iowa State University.

  6. Investigating Irregularly Patterned Deep Brain Stimulation Signal Design Using Biophysical Models

    Directory of Open Access Journals (Sweden)

    Samantha Rose Summerson

    2015-06-01

    Full Text Available Parkinson’s disease (PD is a neurodegenerative disorder which follows from cell loss of dopaminergic neurons in the substantia nigra pars compacta (SNc, a nucleus in the basal ganglia (BG. Deep brain stimulation (DBS is an electrical therapy that modulates the pathological activity to treat the motor symptoms of PD. Although this therapy is currently used in clinical practice, the sufficient conditions for therapeutic efficacy are unknown. In this work we develop a model of critical motor circuit structures in the brain using biophysical cell models as the base components and then evaluate performance of different DBS signals in this model to perform comparative studies of their efficacy. Biological models are an important tool for gaining insights into neural function and, in this case, serve as effective tools for investigating innovative new DBS paradigms. Experiments were performed using the hemi-parkinsonian rodent model to test the same set of signals, verifying the obedience of the model to physiological trends. We show that antidromic spiking from DBS of the subthalamic nucleus (STN has a significant impact on cortical neural activity, which is frequency dependent and additionally modulated by the regularity of the stimulus pulse train used. Irregular spacing between stimulus pulses, where the amount of variability added is bounded, is shown to increase diversification of response of basal ganglia neurons and reduce entropic noise in cortical neurons, which may be fundamentally important to restoration of information flow in the motor circuit.

  7. Transcranial direct current stimulation transiently increases the blood-brain barrier solute permeability in vivo

    Science.gov (United States)

    Shin, Da Wi; Khadka, Niranjan; Fan, Jie; Bikson, Marom; Fu, Bingmei M.

    2016-03-01

    Transcranial Direct Current Stimulation (tDCS) is a non-invasive electrical stimulation technique investigated for a broad range of medical and performance indications. Whereas prior studies have focused exclusively on direct neuron polarization, our hypothesis is that tDCS directly modulates endothelial cells leading to transient changes in blood-brain-barrier (BBB) permeability (P) that are highly meaningful for neuronal activity. For this, we developed state-of-the-art imaging and animal models to quantify P to various sized solutes after tDCS treatment. tDCS was administered using a constant current stimulator to deliver a 1mA current to the right frontal cortex of rat (approximately 2 mm posterior to bregma and 2 mm right to sagittal suture) to obtain similar physiological outcome as that in the human tDCS application studies. Sodium fluorescein (MW=376), or FITC-dextrans (20K and 70K), in 1% BSA mammalian Ringer was injected into the rat (SD, 250-300g) cerebral circulation via the ipsilateral carotid artery by a syringe pump at a constant rate of ~3 ml/min. To determine P, multiphoton microscopy with 800-850 nm wavelength laser was applied to take the images from the region of interest (ROI) with proper microvessels, which are 100-200 micron below the pia mater. It shows that the relative increase in P is about 8-fold for small solute, sodium fluorescein, ~35-fold for both intermediate sized (Dex-20k) and large (Dex-70k) solutes, 10 min after 20 min tDCS pretreatment. All of the increased permeability returns to the control after 20 min post treatment. The results confirmed our hypothesis.

  8. Centromedian-Parafascicular Complex Deep Brain Stimulation for Tourette Syndrome: A Retrospective Study.

    Science.gov (United States)

    Testini, Paola; Zhao, Cong Z; Stead, Matt; Duffy, Penelope S; Klassen, Bryan T; Lee, Kendall H

    2016-02-01

    Deep brain stimulation (DBS) of the thalamic centromedian/parafascicular (CM-Pf) complex has been reported as a promising treatment for patients with severe, treatment-resistant Tourette syndrome (TS). In this study, safety and clinical outcomes of bilateral thalamic CM-Pf DBS were reviewed in a series of 12 consecutive patients with medically refractory TS, 11 of whom met the criteria of postsurgical follow-up at our institution for at least 2 months. Five patients were followed for a year or longer. Consistent with many patients with TS, all patients had psychiatric comorbidities. Tic severity and frequency were measured by using the Yale Global Tic Severity Scale (YGTSS) over time (average, 26 months) in 10 subjects. One patient was tested at 2-week follow-up only and thus was excluded from group YGTSS analysis. Final YGTSS scores differed significantly from the preoperative baseline score. The average (n=10) improvement relative to baseline in the total score was 54% (95% CI, 37-70); average improvement relative to baseline in the YGTSS Motor tic, Phonic tic, and Impairment subtests was 46% (95% CI, 34-64), 52% (95% CI, 34-72), and 59% (95% CI, 39-78), respectively. There were no intraoperative complications. After surgery, 1 subject underwent wound revision because of a scalp erosion and wound infection; the implanted DBS system was successfully salvaged with surgical revision and combined antibiotic therapy. Stimulation-induced adverse effects did not prevent the use of the DBS system, although 1 subject is undergoing a trial period with the stimulator off. This surgical series adds to the literature on CM-Pf DBS and supports its use as an effective and safe therapeutic option for severe refractory TS. PMID:26848003

  9. Deep brain stimulation during pregnancy and delivery: experience from a series of DBS babies

    Directory of Open Access Journals (Sweden)

    Emma eSCELZO

    2015-09-01

    Full Text Available Introduction: Deep brain stimulation (DBS is widely used to improve quality of life in movement disorders and psychiatric diseases. Even though the ability to have children has a big impact on patients’ life, only a few studies describe the role of DBS in pregnancy. Objective: To describe risks and management of women treated by DBS for disabling movement disorders (MD or psychiatric diseases during pregnancy and delivery. Methods: We report a retrospective case series of women, followed in two DBS centers, who became pregnant and went on to give birth to a child while suffering from disabling MD or psychiatric diseases (Parkinson’s disease (PD, dystonia, Tourette’s syndrome (TS, Obsessive Compulsive Disorder (OCD treated by DBS. Clinical status, complications and management before, during and after pregnancy are reported. Two illustrative cases are described in greater detail.Results: DBS improved motor and behavioural disorders in all patients and allowed reduction in, or even total interruption of disease-specific medication during pregnancy. With the exception of the spontaneous early abortion of one fetus in a twin pregnancy, all pregnancies were uneventful in terms of obstetric and pediatric management. DBS parameters were adjusted in five patients in order to limit clinical worsening during pregnancy. Implanted material limited breast-feeding in one patient because of local pain at submammal stimulator site and led to local discomfort related to stretching of the cable with increasing belly size in another patient whose stimulator was implanted in the abdominal wall. Conclusions: Not only is it safe for young women with MD, TS and OCD who have a DBS-System implanted to become pregnant and give birth to a baby but DBS seems to be the key to becoming pregnant, having children, and thus greatly improves quality of life.

  10. Post-mortem Findings in Huntington’s Deep Brain Stimulation: A Moving Target Due to Atrophy

    Science.gov (United States)

    Vedam-Mai, Vinata; Martinez-Ramirez, Daniel; Hilliard, Justin D.; Carbunaru, Samuel; Yachnis, Anthony T.; Bloom, Joshua; Keeling, Peyton; Awe, Lisa; Foote, Kelly D.; Okun, Michael S.

    2016-01-01

    Background Deep brain stimulation (DBS) has been shown to be effective for Parkinson’s disease, essential tremor, and primary dystonia. However, mixed results have been reported in Huntington’s disease (HD). Case Report A single case of HD DBS was identified from the University of Florida DBS Brain Tissue Network. The clinical presentation, evolution, surgical planning, DBS parameters, clinical outcomes, and brain pathological changes are summarized. Discussion This case of HD DBS revealed that chorea may improve and be sustained. Minimal histopathological changes were noted around the DBS leads. Severe atrophy due to HD likely changed the DBS lead position relative to the internal capsule. PMID:27127722

  11. Granulocyte colony-stimulating factor promotes behavioral recovery in a mouse model of traumatic brain injury.

    Science.gov (United States)

    Song, Shijie; Kong, Xiaoyuan; Acosta, Sandra; Sava, Vasyl; Borlongan, Cesar; Sanchez-Ramos, Juan

    2016-05-01

    Hematopoietic growth factors such as granulocyte colony-stimulating factor (G-CSF) represent a novel approach for treatment of traumatic brain injury (TBI). After mild controlled cortical impact (CCI), mice were treated with G-CSF (100 μg/kg) for 3 consecutive days. The primary behavioral endpoint was performance on the radial arm water maze (RAWM), assessed 7 and 14 days after CCI. Secondary endpoints included 1) motor performance on a rotating cylinder (rotarod), 2) measurement of microglial and astroglial response, 3) hippocampal neurogenesis, and 4) measures of neurotrophic factors (brain-derived neurotrophic factor [BDNF] and glial cell line-derived neurotrophic factor [GDNF]) and cytokines in brain homogenates. G-CSF-treated animals performed significantly better than vehicle-treated mice in the RAWM at 1 and 2 weeks but not on the rotarod. Cellular changes found in the G-CSF group included increased hippocampal neurogenesis as well as astrocytosis and microgliosis in both the striatum and the hippocampus. Neurotrophic factors GDNF and BDNF, elaborated by activated microglia and astrocytes, were increased in G-CSF-treated mice. These factors along with G-CSF itself are known to promote hippocampal neurogenesis and inhibit apoptosis and likely contributed to improvement in the hippocampal-dependent learning task. Six cytokines that were modulated by G-CSF treatment following CCI were elevated on day 3, but only one of them remained altered by day 7, and all of them were no different from vehicle controls by day 14. The pro- and anti-inflammatory cytokines modulated by G-CSF administration interact in a complex and incompletely understood network involving both damage and recovery processes, underscoring the dual role of inflammation after TBI. © 2016 Wiley Periodicals, Inc. PMID:26822127

  12. Model-based analysis and design of nerve cuff electrodes for restoring bladder function by selective stimulation of the pudendal nerve

    Science.gov (United States)

    Kent, Alexander R.; Grill, Warren M.

    2013-06-01

    Objective. Electrical stimulation of the pudendal nerve (PN) is being developed as a means to restore bladder function in persons with spinal cord injury. A single nerve cuff electrode placed on the proximal PN trunk may enable selective stimulation of distinct fascicles to maintain continence or evoke micturition. The objective of this study was to design a nerve cuff that enabled selective stimulation of the PN. Approach. We evaluated the performance of both flat interface nerve electrode (FINE) cuff and round cuff designs, with a range of FINE cuff heights and number of contacts, as well as multiple contact orientations. This analysis was performed using a computational model, in which the nerve and fascicle cross-sectional positions from five human PN trunks were systematically reshaped within the nerve cuff. These cross-sections were used to create finite element models, with electric potentials calculated and applied to a cable model of a myelinated axon to evaluate stimulation selectivity for different PN targets. Subsequently, the model was coupled to a genetic algorithm (GA) to identify solutions that used multiple contact activation to maximize selectivity and minimize total stimulation voltage. Main results. Simulations did not identify any significant differences in selectivity between FINE and round cuffs, although the latter required smaller stimulation voltages for target activation due to preserved localization of targeted fascicle groups. Further, it was found that a ten contact nerve cuff generated sufficient selectivity for all PN targets, with the degree of selectivity dependent on the relative position of the target within the nerve. The GA identified solutions that increased fitness by 0.7-45.5% over single contact activation by decreasing stimulation of non-targeted fascicles. Significance. This study suggests that using an optimal nerve cuff design and multiple contact activation could enable selective stimulation of the human PN trunk for

  13. The sum of its parts--effects of gastric distention, nutrient content and sensory stimulation on brain activation.

    Directory of Open Access Journals (Sweden)

    Maartje S Spetter

    Full Text Available During food consumption the brain integrates multiple interrelated neural and hormonal signals involved in the regulation of food intake. Factors influencing the decision to stop eating include the foods' sensory properties, macronutrient content, and volume, which in turn affect gastric distention and appetite hormone responses. So far, the contributions of gastric distention and oral stimulation by food on brain activation have not been studied. The primary objective of this study was to assess the effect of gastric distention with an intra-gastric load and the additional effect of oral stimulation on brain activity after food administration. Our secondary objective was to study the correlations between hormone responses and appetite-related ratings and brain activation. Fourteen men completed three functional magnetic resonance imaging sessions during which they either received a naso-gastric infusion of water (stomach distention, naso-gastric infusion of chocolate milk (stomach distention + nutrients, or ingested chocolate-milk (stomach distention + nutrients + oral exposure. Appetite ratings and blood parameters were measured at several time points. During gastric infusion, brain activation was observed in the midbrain, amygdala, hypothalamus, and hippocampus for both chocolate milk and water, i.e., irrespective of nutrient content. The thalamus, amygdala, putamen and precuneus were activated more after ingestion than after gastric infusion of chocolate milk, whereas infusion evoked greater activation in the hippocampus and anterior cingulate. Moreover, areas involved in gustation and reward were activated more after oral stimulation. Only insulin responses following naso-gastric infusion of chocolate milk correlated with brain activation, namely in the putamen and insula. In conclusion, we show that normal (oral food ingestion evokes greater activation than gastric infusion in stomach distention and food intake-related brain areas. This

  14. Treatment of ADCY5-Associated Dystonia, Chorea, and Hyperkinetic Disorders With Deep Brain Stimulation: A Multicenter Case Series.

    Science.gov (United States)

    Dy, Marisela E; Chang, Florence C F; Jesus, Sol De; Anselm, Irina; Mahant, Neil; Zeilman, Pamela; Rodan, Lance H; Foote, Kelly D; Tan, Wen-Hann; Eskandar, Emad; Sharma, Nutan; Okun, Michael S; Fung, Victor S C; Waugh, Jeff L

    2016-07-01

    ADCY5 mutations have been reported as a cause of early onset hyperkinetic movements associated with delayed motor milestones, hypotonia, and exacerbation during sleep. The movement disorder may be continuous or episodic, and can vary considerably in severity within families and in individuals. The authors report a case series of 3 patients with ADCY5 mutations treated with deep brain stimulation after unsuccessful medication trials. All had extensive imaging, metabolic, and genetic testing prior to confirmation of their ADCY5 mutation. Two of the patients had the c.1252C>T; p.R418W mutation, while the youngest and most severely affected had a de novo c.2080_2088del; p.K694_M696 mutation. All had variable and incomplete, but positive responses to deep brain stimulation. The authors conclude that deep brain stimulation may provide benefit in ADCY5-related movement disorders. Long-term efficacy remains to be confirmed by longitudinal observation. ADCY5 should be considered in the differential diagnosis of early onset hyperkinetic movement disorders, and may respond to deep brain stimulation. PMID:27052971

  15. Transient hypoxia stimulates mitochondrial biogenesis in brain subcortex by a neuronal nitric oxide synthase-dependent mechanism

    Science.gov (United States)

    The adaptive mechanisms that protect brain metabolism during and after hypoxia, for instance, during hypoxic preconditioning, are coordinated in part by nitric oxide (NO). We tested the hypothesis that acute transient hypoxia stimulates NO synthase (NOS)-activated mechanisms of m...

  16. Deep brain stimulation of the subthalamic nucleus improves reward-based decision-learning in Parkinson’s disease

    NARCIS (Netherlands)

    Wouwe, N.C. van; Ridderinkhof, K.R.; Wildenberg, W.P.M. van den; Band, G.P.H.; Abisogun, A.; Elias, W.J.; Frysinger, R.; Wylie, S.A.

    2011-01-01

    Recently, the subthalamic nucleus (STN) has been shown to be critically involved in decision-making, action selection, and motor control. Here we investigate the effect of deep brain stimulation (DBS) of the STN on reward-based decision-learning in patients diagnosed with Parkinson’s disease (PD). W

  17. Proceedings of the Third Annual Deep Brain Stimulation Think Tank: A Review of Emerging Issues and Technologies

    OpenAIRE

    Rossi, P. Justin; Gunduz, Aysegul; Judy, Jack; Wilson, Linda; Machado, Andre; James J Giordano; Elias, W. Jeff; Rossi, Marvin A.; Butson, Christopher L.; Fox, Michael D.; McIntyre, Cameron C.; Pouratian, Nader; Swann, Nicole C.; de Hemptinne, Coralie; Gross, Robert E.

    2016-01-01

    The proceedings of the 3rd Annual Deep Brain Stimulation Think Tank summarize the most contemporary clinical, electrophysiological, imaging, and computational work on DBS for the treatment of neurological and neuropsychiatric disease. Significant innovations of the past year are emphasized. The Think Tank's contributors represent a unique multidisciplinary ensemble of expert neurologists, neurosurgeons, neuropsychologists, psychiatrists, scientists, engineers, and members of industry. Present...

  18. Intensive Voice Treatment (LSVT[R]LOUD) for Parkinson's Disease Following Deep Brain Stimulation of the Subthalamic Nucleus

    Science.gov (United States)

    Spielman, Jennifer; Mahler, Leslie; Halpern, Angela; Gilley, Phllip; Klepitskaya, Olga; Ramig, Lorraine

    2011-01-01

    Purpose: Intensive voice therapy (LSVT[R]LOUD) can effectively manage voice and speech symptoms associated with idiopathic Parkinson disease (PD). This small-group study evaluated voice and speech in individuals with and without deep brain stimulation of the subthalamic nucleus (STN-DBS) before and after LSVT LOUD, to determine whether outcomes…

  19. Pitch Variability in Patients with Parkinson's Disease: Effects of Deep Brain Stimulation of Caudal Zona Incerta and Subthalamic Nucleus

    Science.gov (United States)

    Karlsson, Fredrik; Olofsson, Katarina; Blomstedt, Patric; Linder, Jan; van Doorn, Jan

    2013-01-01

    Purpose: The purpose of the present study was to examine the effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and the caudal zona incerta (cZi) pitch characteristics of connected speech in patients with Parkinson's disease (PD). Method: The authors evaluated 16 patients preoperatively and 12 months after DBS surgery. Eight…

  20. Current status of deep brain stimulation for obsessive-compulsive disorder: a clinical review of different targets

    NARCIS (Netherlands)

    P.P. de Koning; M. Figee; P. van den Munckhof; P.R. Schuurman; D. Denys

    2011-01-01

    Obsessive-compulsive disorder (OCD) is a chronic psychiatric disorder that affects 2% of the general population. Despite optimal cognitive-behavioral and pharmacologic therapy, approximately 10% of patients remain treatment resistant. Currently, deep brain stimulation (DBS) is being investigated as