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1

Temperature Control at DBS Electrodes using Heat Sink: Experimentally Validated FEM Model of DBS lead Architecture  

PubMed Central

There is a growing interest in the use of Deep Brain Stimulation for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. MRI) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols, and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: 1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); 2) does not interfere with device efficacy; and 3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure.

Elwassif, Maged M.; Datta, Abhishek; Rahman, Asif; Bikson, Marom

2012-01-01

2

Adaptive deep brain stimulation (aDBS) controlled by local field potential oscillations.  

PubMed

Despite their proven efficacy in treating neurological disorders, especially Parkinson's disease, deep brain stimulation (DBS) systems could be further optimized to maximize treatment benefits. In particular, because current open-loop DBS strategies based on fixed stimulation settings leave the typical parkinsonian motor fluctuations and rapid symptom variations partly uncontrolled, research has for several years focused on developing novel "closed-loop" or "adaptive" DBS (aDBS) systems. aDBS consists of a simple closed-loop model designed to measure and analyze a control variable reflecting the patient's clinical condition to elaborate new stimulation settings and send them to an "intelligent" implanted stimulator. The major problem in developing an aDBS system is choosing the ideal control variable for feedback. Here we review current evidence on the advantages of neurosignal-controlled aDBS that uses local field potentials (LFPs) as a control variable, and describe the technology already available to create new aDBS systems, and the potential benefits of aDBS for patients with Parkinson's disease. PMID:23022916

Priori, Alberto; Foffani, Guglielmo; Rossi, Lorenzo; Marceglia, Sara

2013-07-01

3

Targeting the brain: considerations in 332 consecutive patients treated by deep brain stimulation (DBS) for severe neurological diseases.  

PubMed

Deep brain stimulation (DBS) extends the treatment of some severe neurological diseases beyond pharmacological and conservative therapy. Our experience extends the field of DBS beyond the treatment of Parkinson disease and dystonia, including several other diseases such as cluster headache and disruptive behavior. Since 1993, at the Istituto Nazionale Neurologico "Carlo Besta" in Milan, 580 deep brain electrodes were implanted in 332 patients. The DBS targets include Stn, GPi, Voa, Vop, Vim, CM-pf, pHyp, cZi, Nacc, IC, PPN, and Brodmann areas 24 and 25. Three hundred patients are still available for follow-up and therapeutic considerations. DBS gave a new therapeutic chance to these patients affected by severe neurological diseases and in some cases controlled life-threatening pathological conditions, which would otherwise result in the death of the patient such as in status dystonicus, status epilepticus and post-stroke hemiballismus. The balance of DBS in severe neurological disease is strongly positive even if further investigations and studies are needed to search for new applications and refine the selection criteria for the actual indications. PMID:22271259

Franzini, Angelo; Cordella, Roberto; Messina, Giuseppe; Marras, Carlo Efisio; Romito, Luigi Michele; Albanese, Alberto; Rizzi, Michele; Nardocci, Nardo; Zorzi, Giovanna; Zekaj, Edvin; Villani, Flavio; Leone, Massimo; Gambini, Orsola; Broggi, Giovanni

2012-12-01

4

Long-Term management of DBS in dystonia: response to stimulation, adverse events, battery changes, and special considerations.  

PubMed

Multiple independent case series have documented sustained benefit of bilateral pallidal deep brain stimulation (DBS) up to 3 years in patients with primary dystonia. Growing evidence exists for positive outcomes extending up to 10 years. The beneficial effects from DBS are usually reported to be stable, thus requiring little long-term modifications of the parameters of stimulation. Speech and swallowing abnormalities are less responsive than other dystonic symptoms. Symptom exacerbation after initial benefit has been reported in a few cases. It is not known whether this is related to potential tolerance or habituation to stimulation or to progression of the underlying disease. Failures of pallidal DBS, at least in primary dystonia patients, should not be accepted without further re-evaluation of each individual case, including possible revisions of the electrode location. Both hardware- and stimulation-related adverse effects, including insufficient relief of speech function, have been reported in the long-term. Despite early reports suggesting that hardware problems might be more frequent in dystonia, more recent studies did not confirm these observations. In patients with severe segmental (e.g., axial) or generalized dystonia, sudden cessation of stimulation may become a medical emergency and should be anticipated changing the neurostimulator before its natural end of life. PMID:21692113

Tagliati, Michele; Krack, Paul; Volkmann, Jens; Aziz, Tipu; Krauss, Joachim K; Kupsch, Andreas; Vidailhet, And Marie

2011-06-01

5

Deep brain stimulation (DBS) at the interface of neurology and psychiatry.  

PubMed

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 neuropsychiatric conditions: Parkinson disease, Tourette syndrome, major depressive disorder, and obsessive-compulsive disorder. Based on emerging new research, we summarize novel approaches to optimization of stimulation for each neuropsychiatric disease and we review the potential positive and negative effects that may be observed following DBS. Finally, we summarize the likely future innovations in the field of electrical neural-network modulation. PMID:24177464

Williams, Nolan R; Okun, Michael S

2013-11-01

6

Deep brain stimulation (DBS) at the interface of neurology and psychiatry  

PubMed Central

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 neuropsychiatric conditions: Parkinson disease, Tourette syndrome, major depressive disorder, and obsessive-compulsive disorder. Based on emerging new research, we summarize novel approaches to optimization of stimulation for each neuropsychiatric disease and we review the potential positive and negative effects that may be observed following DBS. Finally, we summarize the likely future innovations in the field of electrical neural-network modulation.

Williams, Nolan R.; Okun, Michael S.

2013-01-01

7

Modeling deep brain stimulation: point source approximation versus realistic representation of the electrode  

NASA Astrophysics Data System (ADS)

Deep brain stimulation (DBS) has emerged as an effective treatment for movement disorders; however, the fundamental mechanisms by which DBS works are not well understood. Computational models of DBS can provide insights into these fundamental mechanisms and typically require two steps: calculation of the electrical potentials generated by DBS and, subsequently, determination of the effects of the extracellular potentials on neurons. The objective of this study was to assess the validity of using a point source electrode to approximate the DBS electrode when calculating the thresholds and spatial distribution of activation of a surrounding population of model neurons in response to monopolar DBS. Extracellular potentials in a homogenous isotropic volume conductor were calculated using either a point current source or a geometrically accurate finite element model of the Medtronic DBS 3389 lead. These extracellular potentials were coupled to populations of model axons, and thresholds and spatial distributions were determined for different electrode geometries and axon orientations. Median threshold differences between DBS and point source electrodes for individual axons varied between -20.5% and 9.5% across all orientations, monopolar polarities and electrode geometries utilizing the DBS 3389 electrode. Differences in the percentage of axons activated at a given amplitude by the point source electrode and the DBS electrode were between -9.0% and 12.6% across all monopolar configurations tested. The differences in activation between the DBS and point source electrodes occurred primarily in regions close to conductor-insulator interfaces and around the insulating tip of the DBS electrode. The robustness of the point source approximation in modeling several special cases—tissue anisotropy, a long active electrode and bipolar stimulation—was also examined. Under the conditions considered, the point source was shown to be a valid approximation for predicting excitation of populations of neurons in response to DBS.

Zhang, Tianhe C.; Grill, Warren M.

2010-12-01

8

Modeling Deep Brain Stimulation: Point Source Approximation vs. Realistic Representation of the Electrode  

PubMed Central

Deep brain stimulation (DBS) has emerged as an effective treatment for movement disorders; however, the fundamental mechanisms by which DBS works are not well understood. Computational models of DBS can provide insights into these fundamental mechanisms and typically require two steps: calculation of the electrical potentials generated by DBS and, subsequently, determination of the effects of the extracellular potentials on neurons. The objective of this study was to assess the validity of using a point source electrode to approximate the DBS electrode when calculating the thresholds and spatial distribution of activation of a surrounding population of model neurons in response to monopolar DBS. Extracellular potentials in a homogenous isotropic volume conductor were calculated using either a point current source or a geometrically accurate finite element model of the Medtronic DBS 3389 lead. These extracellular potentials were coupled to populations of model axons, and thresholds and spatial distributions were determined for different electrode geometries and axon orientations. Median threshold differences between DBS and point source electrodes for individual axons varied between ?20.5% and 9.5% across all orientations, monopolar polarities, and electrode geometries utilizing the DBS 3389 electrode. Differences in the percentage of axons activated at a given amplitude by the point source electrode and the DBS electrode were between ?9.0% and 12.6% across all monopolar configurations tested. The differences in activation between the DBS and point source electrodes occurred primarily in regions close to conductor-insulator interfaces and around the insulating tip of the DBS electrode. The robustness of the point source approximation in modeling several special cases--tissue anisotropy, a long active electrode, and bipolar stimulation--was also examined. Under the conditions considered, the point source was shown to be a valid approximation for predicting excitation of populations of neurons in response to DBS.

Zhang, Tianhe C; Grill, Warren M

2010-01-01

9

Deep brain stimulation electrode anchoring using BioGlue((R)), a protective electrode covering, and a titanium microplate.  

PubMed

The authors present an easily applicable deep brain stimulation (DBS) electrode anchoring technique for use in human and experimental animals. The anchoring technique combines the use of fibrin glue, a two-component surgical adhesive (BioGlue), a protective electrode covering, and a titanium microplate. The BioGlue (CryoLife International, Inc., Kennesaw, GA, USA) hinders unwanted electrode movement during the electrode fixation step and seals the burr hole, while the protective electrode covering protects the electrode under the titanium microplate which keeps the electrode in a permanent position. The described technique further has the advantage of being cosmetically acceptable to the human patient, and furthermore it perfectly adapts to the smaller and irregular-shaped skull in experimental animals. The described technique has clinically been used to implant DBS-electrodes in the subthalamic nucleus for Parkinson disease and is the preferred DBS-electrode anchoring technique for our experimental DBS-studies in the Göttingen minipig. PMID:17953993

Bjarkam, Carsten R; Jorgensen, Rasmus L; Jensen, Kristian N; Sunde, Niels Aa; Sřrensen, Jens-Christian H

2008-02-15

10

Deep brain stimulation induces BOLD activation in motor and non-motor networks: An fMRI comparison study of STN and EN/GPi DBS in large animals  

PubMed Central

The combination of deep brain stimulation (DBS) and functional MRI (fMRI) is a powerful means of tracing brain circuitry and testing the modulatory effects of electrical stimulation on a neuronal network in vivo. The goal of this study was to trace DBS-induced global neuronal network activation in a large animal model by monitoring the blood oxygenation level-dependent (BOLD) response on fMRI. We conducted DBS in normal anesthetized pigs, targeting the subthalamic nucleus (STN) (n=7) and the entopeduncular nucleus (EN), the non-primate analogue of the primate globus pallidus interna (n=4). Using a normalized functional activation map for group analysis and the application of general linear modeling across subjects, we found that both STN and EN DBS significantly increased BOLD activation in the ipsilateral sensorimotor network (FDR < 0.001). In addition, we found differential, target-specific, non-motor network effects. In each group the activated brain areas showed a distinctive correlation pattern forming a group of network connections. Results suggest that the scope of DBS extends beyond an ablation-like effect and that it may have modulatory effects not only on circuits that facilitate motor function but also on those involved in higher cognitive and emotional processing. Taken together, our results show that the swine model for DBS fMRI, which conforms to human implanted DBS electrode configurations and human neuroanatomy, may be a useful platform for translational studies investigating the global neuromodulatory effects of DBS.

Min, Hoon-Ki; Hwang, Sun-Chul; Marsh, Michael P.; Kim, Inyong; Knight, Emily; Striemer, Bryan; Felmlee, Joel P.; Welker, Kirk M.; Blaha, Charles D.; Chang, Su-Youne; Bennet, Kevin E.; Lee, Kendall H.

2012-01-01

11

Pathological Alterations and Stress Responses near DBS Electrodes after MRI Scans at 7.0T, 3.0T and 1.5T: An In Vivo Comparative Study  

PubMed Central

Objective The purpose of this study was to investigate the pathological alterations and the stress responses around deep brain stimulation (DBS) electrodes after magnetic resonance imaging (MRI) scans at 7.0T, 3.0T and 1.5T. Materials and Methods DBS devices were stereotactically implanted into the brains of New Zealand rabbits, targeting the left nucleus ventralis posterior thalami, while on the right side, a puncture passage pointing to the same target was made. MRI scans at 7.0T, 3.0T and 1.5T were performed using transmit/receive head coils. The pathological alterations of the surrounding tissue were evaluated by hematoxylin and eosin staining (H&E staining) and transmission electron microscopy (TEM). The levels of the 70 kDa heat shock protein (HSP-70), Neuronal Nuclei (NeuN) and Caspase-3 were determined by western-blotting and quantitative polymerase chain reaction (QPCR) to assess the stress responses near the DBS electrodes. Results H&E staining and TEM showed that the injury around the DBS electrodes was featured by a central puncture passage with gradually weakened injurious alterations. Comparisons of the injury across the groups manifested similar pathological alterations near the DBS electrodes in each group. Moreover, western-blotting and QPCR assay showed that the level of HSP-70 was not elevated by MRI scans (p>0.05), and the levels of NeuN and Caspase-3 were equal in each group, regardless of the field strengths applied (p>0.05). Conclusions Based on these findings, it is reasonable to conclude that in this study the MRI scans at multiple levels failed to induce additional tissue injury around the DBS electrodes. These preliminary data furthered our understanding of MRI-related DBS heating and encouraged revisions of the current MRI guidelines for patients with DBS devices.

Meng, Da-Wei; Li, Shao-Wu; Liu, Huan-Guang; Li, Jun-Ju; Wang, Xiu; Zhang, Xin; Zhang, Jian-Guo

2014-01-01

12

CranialVault and its CRAVE tools: a clinical computer assistance system for Deep Brain Stimulation (DBS) therapy  

PubMed Central

A number of methods have been developed to assist surgeons at various stages of deep brain stimulation (DBS) therapy. These include construction of anatomical atlases, functional databases, and electrophysiological atlases and maps. But, a complete system that can be integrated into the clinical workflow has not been developed. In this paper we present a system designed to assist physicians in pre-operative target planning, intra-operative target refinement and implantation, and post-operative DBS lead programming. The purpose of this system is to centralize the data acquired a the various stages of the procedure, reduce the amount of time needed at each stage of the therapy, and maximize the efficiency of the entire process. The system consists of a central repository (CranialVault), of a suite of software modules called CRAVE (CRAnialVault Explorer) that permit data entry and data visualization at each stage of the therapy, and of a series of algorithms that permit the automatic processing of the data. The central repository contains image data for more than 400 patients with the related pre-operative plans and position of the final implants and about 10,550 electrophysiological data points (micro-electrode recordings or responses to stimulations) recorded from 222 of these patients. The system has reached the stage of a clinical prototype that is being evaluated clinically at our institution. A preliminary quantitative validation of the planning component of the system performed on 80 patients who underwent the procedure between January 2009 and December 2009 shows that the system provides both timely and valuable information.

D'Haese, Pierre-Francois; Pallavaram, Srivatsan; Li, Rui; Remple, Michael S.; Kao, Chris; Neimat, Joseph S.; Konrad, Peter E.; Dawant, Benoit M.

2010-01-01

13

Influences of Interpolation Error, Electrode Geometry, and the Electrode-Tissue Interface on Models of Electric Fields Produced by Deep Brain Stimulation  

PubMed Central

Deep brain stimulation (DBS) is an established therapy for movement disorders, but the fundamental mechanisms by which DBS has its effects remain unknown. Computational models can provide insights into the mechanisms of DBS, but to be useful, the models must have sufficient detail to predict accurately the electric fields produced by DBS. We used a finite element method model of the Medtronic 3387 electrode array, coupled to cable models of myelinated axons, to quantify how interpolation errors, electrode geometry, and the electrode-tissue interface affect calculation of electrical potentials and stimulation thresholds for populations of model nerve fibers. Convergence of the potentials was not a sufficient criterion for ensuring the same degree of accuracy in subsequent determination of stimulation thresholds, because the accuracy of the stimulation thresholds depended on the order of the elements. Simplifying the 3387 electrode array by ignoring the inactive contacts and extending the terminated end of the shaft had position dependent effects on the potentials and excitation thresholds, and these simplifications may impact correlations between DBS parameters and clinical outcomes. When the current density in the bulk tissue is uniform, the effect of the electrode-tissue interface impedance could be approximated by filtering the potentials calculated with a static lumped electrical equivalent circuit. Further, for typical DBS parameters during voltage-regulated stimulation, it was valid to approximate the electrode as an ideal polarized electrode with a nonlinear capacitance. Validation of these computational considerations enables accurate modeling of the electric field produced by DBS.

Howell, Bryan; Naik, Sagar; Grill, Warren M.

2014-01-01

14

Impedance characteristics of deep brain stimulation electrodes in vitro and in vivo  

PubMed Central

The objective of this study was to quantify the electrode-tissue interface impedance of electrodes used for deep brain stimulation (DBS). We measured the impedance of DBS electrodes using electrochemical impedance spectroscopy in vitro in carbonate and phosphate buffered saline solution and in vivo following acute implantation in the brain. The components of the impedance, including the series resistance (Rs), the Faradaic resistance (Rf) and the double layer capacitance (Cdl), were estimated using an equivalent electrical circuit. Both Rf and Cdl decreased as the sinusoidal frequency was increased, but the ratio of capacitive charge transfer to Faradaic charge transfer was relatively insensitive to the change of frequency. Rf decreased and Cdl increased as the current density was increased, and above a critical current density the interface impedance became nonlinear. Thus the magnitude of the interface impedance was strongly dependent on the intensity (pulse amplitude and duration) of stimulation. The temporal dependence and spatial non-uniformity of Rf and Cdl suggested that a distributed network, with each element of the network having dynamics tailored to a specific stimulus waveform, is required to describe adequately the impedance of the DBS electrode-tissue interface. Voltage transients to biphasic square current pulses were measured and suggested that the electrode-tissue interface did not operate in a linear range at clinically-relevant current amplitudes, and that the assumption of the DBS electrode being ideally polarizable was not valid under clinical stimulating conditions.

Wei, Xuefeng F.; Grill, Warren M.

2011-01-01

15

Evaluation of high-perimeter electrode designs for deep brain stimulation.  

PubMed

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, complications including infections and mis-programing following surgical replacement of the battery-powered implantable pulse generator adversely impact the safety profile of this therapy. We sought to decrease power consumption and extend battery life by modifying the electrode geometry to increase stimulation efficiency. The specific goal of this study was to determine whether electrode contact perimeter or area had a greater effect on increasing stimulation efficiency. Approach. Finite-element method (FEM) models of eight prototype electrode designs were used to calculate the electrode access resistance, and the FEM models were coupled with cable models of passing axons to quantify stimulation efficiency. We also measured in vitro the electrical properties of the prototype electrode designs and measured in vivo the stimulation efficiency following acute implantation in anesthetized cats. Main results. Area had a greater effect than perimeter on altering the electrode access resistance; electrode (access or dynamic) resistance alone did not predict stimulation efficiency because efficiency was dependent on the shape of the potential distribution in the tissue; and, quantitative assessment of stimulation efficiency required consideration of the effects of the electrode-tissue interface impedance. Significance. These results advance understanding of the features of electrode geometry that are important for designing the next generation of efficient DBS electrodes. PMID:25029124

Howell, Bryan; Grill, Warren M

2014-08-01

16

Electrode array for neural stimulation  

DOEpatents

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.

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

17

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

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

18

Study on DBS device for small animals.  

PubMed

Although deep brain stimulation (DBS) therapy has been achieved, fine tuning on the operational parameters and the equipment are needed in order to make the stimulation treatment more applicable. Thus, the purpose of this study is to design and produce a deep brain stimulation device for DBS experiments for small animals (e.g. rats). Physical size, durability, cost of device and convenience of operation are the major focuses in this study. The designed pulse generator can produce pulses with adjustable frequencies, pulse widths and amplitudes. Telemetry and remote control of the system reduced the physical size of the implant component. Battery voltage measurement and electrode impedance measurement justified the values of parameters applied for stimulation. Power consumption is low enough and test results show it is expected to work for more than three months when using typical pulse parameters. Finally, we use the device on the DBS experiment of rats. The results prove that the design of the device can fulfill the requirements for deep brain stimulation in animal experiments. PMID:22255893

Qian, Xing; Hao, Hongwei; Ma, Bozhi; Wen, Xiongwei; Li, Luming

2011-01-01

19

Deep brain stimulation  

MedlinePLUS

Globus pallidus deep brain stimulation; Subthalamic deep brain stimulation; Thalamic deep brain stimulation; DBS ... lead, or electrode that is placed into the brain The neurostimulator, similar to a heart pacemaker, which ...

20

Analysis of deep brain stimulation electrode characteristics for neural recording.  

PubMed

Objective. Closed-loop deep brain stimulation (DBS) systems have the potential to optimize treatment of movement disorders by enabling automatic adjustment of stimulation parameters based on a feedback signal. Evoked compound action potentials (ECAPs) and local field potentials (LFPs) recorded from the DBS electrode may serve as suitable closed-loop control signals. The objective of this study was to understand better the factors that influence ECAP and LFP recording, including the physical presence of the electrode, the geometrical dimensions of the electrode, and changes in the composition of the peri-electrode space across recording conditions. Approach. Coupled volume conductor-neuron models were used to calculate single-unit activity as well as ECAP responses and LFP activity from a population of model thalamic neurons. Main results. Comparing ECAPs and LFPs measured with and without the presence of the highly conductive recording contacts, we found that the presence of these contacts had a negligible effect on the magnitude of single-unit recordings, ECAPs (7% RMS difference between waveforms), and LFPs (5% change in signal magnitude). Spatial averaging across the contact surface decreased the ECAP magnitude in a phase-dependent manner (74% RMS difference), resulting from a differential effect of the contact on the contribution from nearby or distant elements, and decreased the LFP magnitude (25% change). Reductions in the electrode diameter or recording contact length increased signal energy and increased spatial sensitivity of single neuron recordings. Moreover, smaller diameter electrodes (500 µm) were more selective for recording from local cells over passing axons, with the opposite true for larger diameters (1500 µm). Changes in electrode dimensions had phase-dependent effects on ECAP characteristics, and generally had small effects on the LFP magnitude. ECAP signal energy and LFP magnitude decreased with tighter contact spacing (100 µm), compared to the original dimensions (1500 µm), with the opposite effect on the ECAP at longer contact-to-contact distances (2000 µm). Finally, acute edema reduced the single neuron and population ECAP signal energy, as well as LFP magnitude, and glial encapsulation had the opposite effect, after accounting for loss of cells in the peri-electrode space. Significance. This study determined recording conditions and electrode designs that influence ECAP and LFP recording fidelity. PMID:24921984

Kent, Alexander R; Grill, Warren M

2014-08-01

21

Analysis of deep brain stimulation electrode characteristics for neural recording  

NASA Astrophysics Data System (ADS)

Objective. Closed-loop deep brain stimulation (DBS) systems have the potential to optimize treatment of movement disorders by enabling automatic adjustment of stimulation parameters based on a feedback signal. Evoked compound action potentials (ECAPs) and local field potentials (LFPs) recorded from the DBS electrode may serve as suitable closed-loop control signals. The objective of this study was to understand better the factors that influence ECAP and LFP recording, including the physical presence of the electrode, the geometrical dimensions of the electrode, and changes in the composition of the peri-electrode space across recording conditions. Approach. Coupled volume conductor-neuron models were used to calculate single-unit activity as well as ECAP responses and LFP activity from a population of model thalamic neurons. Main results. Comparing ECAPs and LFPs measured with and without the presence of the highly conductive recording contacts, we found that the presence of these contacts had a negligible effect on the magnitude of single-unit recordings, ECAPs (7% RMS difference between waveforms), and LFPs (5% change in signal magnitude). Spatial averaging across the contact surface decreased the ECAP magnitude in a phase-dependent manner (74% RMS difference), resulting from a differential effect of the contact on the contribution from nearby or distant elements, and decreased the LFP magnitude (25% change). Reductions in the electrode diameter or recording contact length increased signal energy and increased spatial sensitivity of single neuron recordings. Moreover, smaller diameter electrodes (500 µm) were more selective for recording from local cells over passing axons, with the opposite true for larger diameters (1500 µm). Changes in electrode dimensions had phase-dependent effects on ECAP characteristics, and generally had small effects on the LFP magnitude. ECAP signal energy and LFP magnitude decreased with tighter contact spacing (100 µm), compared to the original dimensions (1500 µm), with the opposite effect on the ECAP at longer contact-to-contact distances (2000 µm). Finally, acute edema reduced the single neuron and population ECAP signal energy, as well as LFP magnitude, and glial encapsulation had the opposite effect, after accounting for loss of cells in the peri-electrode space. Significance. This study determined recording conditions and electrode designs that influence ECAP and LFP recording fidelity.

Kent, Alexander R.; Grill, Warren M.

2014-08-01

22

Mood Response to Deep Brain Stimulation of the Subthalamic Nucleus in Parkinson Disease  

PubMed Central

Deep brain stimulation of the subthalamic nucleus (STN DBS) in Parkinson disease (PD) improves motor function but has variable effects on mood. Little is known about the relationship between electrode contact location and mood response. We identified the anatomical location of electrode contacts and measured mood response to stimulation with the Visual Analog Scale in 24 STN DBS PD patients. Participants reported greater positive mood, decreased anxiety and apathy with bilateral and unilateral stimulation. Left DBS improved mood more than right DBS. Right DBS-induced increase in positive mood was related to more medial and dorsal contact locations. These results highlight the functional heterogeneity of the STN.

Campbell, Meghan C.; Black, Kevin J.; Weaver, Patrick M.; Lugar, Heather M.; Videen, Tom O.; Tabbal, Samer D.; Karimi, Morvarid; Perlmutter, Joel S.; Hershey, Tamara

2012-01-01

23

Disrupting neuronal transmission: mechanism of DBS?  

PubMed Central

Applying high-frequency stimulation (HFS) to deep brain structure, known as deep brain stimulation (DBS), has now been recognized an effective therapeutic option for a wide range of neurological and psychiatric disorders. DBS targeting the basal ganglia thalamo-cortical loop, especially the internal segment of the globus pallidus (GPi), subthalamic nucleus (STN) and thalamus, has been widely employed as a successful surgical therapy for movement disorders, such as Parkinson’s disease, dystonia and tremor. However, the neurophysiological mechanism underling the action of DBS remains unclear and is still under debate: does DBS inhibit or excite local neuronal elements? In this review, we will examine this question and propose the alternative interpretation: DBS dissociates inputs and outputs, resulting in disruption of abnormal signal transmission.

Chiken, Satomi; Nambu, Atsushi

2014-01-01

24

Brain energization in response to deep brain stimulation of subthalamic nuclei in Parkinson's disease  

Microsoft Academic Search

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment in a subgroup of medically refractory patients with Parkinson's disease (PD). Here, we compared resting-state 18F-fluorodeoxyglucose (FDG) positron emission tomography images in the stimulator off (DBS_OFF) and on (DBS_ON) conditions in eight PD patients in an unmedicated state, on average 2 years after bilateral electrode implantation. Global

Gaëtan Garraux; Mohamed A Bahri; Christian Lemaire; Christian Degueldre; Eric Salmon; Bruno Kaschten

2011-01-01

25

Neuropsychiatric symptoms three years after subthalamic DBS in PD patients  

Microsoft Academic Search

Objective\\u000a   To evaluate neuropsychiatric symptoms in PD patients submitted to bilateral deep brain stimulation of the subthalamic nucleus\\u000a (DBS-STN) by comparison with a control group of PD patients not treated with DBS.\\u000a \\u000a \\u000a \\u000a \\u000a Methods\\u000a   25 consecutive PD patients bilaterally implanted for DBS of STN (DBS group) were compared to a control group of 25 not operated\\u000a PD patients (CT group) for

Lorys Castelli; Maurizio Zibetti; Laura Rizzi; Marcella Caglio; Michele Lanotte; Leonardo Lopiano

2008-01-01

26

Revision and removal of stimulating electrodes following long-term therapy with the vagus nerve stimulator  

Microsoft Academic Search

BACKGROUNDA significant concern about vagus nerve stimulation therapy has been the disposition of the spiral stimulating electrodes once treatment is considered ineffective or is no longer desired. Because the electrodes are wrapped around the vagus nerve, there is the potential for nerve injury during their removal.METHODSWe attempted removal of the spiral stimulating electrodes from 10 patients who received long-term vagus

Jose Espinosa; Mary T Aiello; Dean K Naritoku

1999-01-01

27

Differential effects of deep brain stimulation on verbal fluency.  

PubMed

We aimed at gaining insights into principles of subcortical lexical processing. Therefore, effects of deep brain stimulation (DBS) in different target structures on verbal fluency (VF) were tested. VF was assessed with active vs. inactivated DBS in 13 and 14 patients with DBS in the vicinity of the thalamic ventral intermediate nucleus (VIM) and, respectively, of the subthalamic nucleus (STN). Results were correlated to electrode localizations in postoperative MRI, and compared to those of 12 age-matched healthy controls. Patients' VF performance was generally below normal. However, while activation of DBS in the vicinity of VIM provoked marked VF decline, it induced subtle phonemic VF enhancement in the vicinity of STN. The effects correlated with electrode localizations in left hemispheric stimulation sites. The results show distinct dependencies of VF on DBS in the vicinity of VIM vs. STN. Particular risks for deterioration occur in patients with relatively ventromedial thalamic electrodes. PMID:24815947

Ehlen, Felicitas; Schoenecker, Thomas; Kühn, Andrea A; Klostermann, Fabian

2014-07-01

28

Occipital nerve stimulation using a medtronic resume II electrode array.  

PubMed

Subcutaneous stimulation of the occipital nerve has been reported using percutaneously placed spinal cord stimulator electrodes. Occasionally, gradual loss of effectiveness has been noted possibly due to scar formation around the contacts. We report on the use of the Medtronic Resume II(R), peripheral nerve / spinal cord stimulator electrode for causing peripheral stimulation of the occipital nerve in the suboccipital region. Initial results suggest improved stimulation with lower power requirements using this larger electrode. The larger contact size might lessen the effect of scar formation and offer improved stimulation over a longer period. PMID:16871305

Jones, Rodney L

2003-10-01

29

DBS Candidates That Fall Short on a Levodopa Challenge Test  

PubMed Central

Introduction Candidacy for deep brain stimulation (DBS) in Parkinson disease (PD) is typically assessed by the preoperative motor response to levodopa along with an interdisciplinary evaluation. However, recent cases treated at our institution have achieved good outcomes with DBS despite a sub-30% improvement in motor scores. The aim of this study was to examine the outcomes of DBS in a subset of patients who failed to reach the 30% motor improvement threshold. Methods A review of all DBS patients treated at the University of Florida Movement Disorders Center between 2002 and 2009 was performed utilizing a DBS database. All patients with sub-30% improvement in Unified Parkinson Disease Rating Scale Part III after dopaminergic medication administration were included. Results Nine patients were identified; DBS was performed for severe dyskinesia (n = 5), “on/off motor” fluctuations (n = 1) and medication-refractory tremor (n = 3). The target symptoms were improved in all patients. Postoperatively, scores on the Unified Parkinson Disease Rating Scale Part II and III and subscores on Parkinson disease questionnaire-39 improved (P < 0.05). Conclusions Although motor response to levodopa remains the primary selection criteria for DBS candidacy in Parkinson disease, patients who do not meet the 30% threshold and have disabling symptoms may still benefit from DBS. Select patients with severe dyskinesia, “on/off” motor fluctuations, and/or medication-refractory tremor may experience significant benefits from DBS and should be considered on a case by case basis through an interdisciplinary team evaluation.

Morishita, Takashi; Rahman, Maryam; Foote, Kelly D.; Fargen, Kyle M.; Jacobson, Charles E.; Fernandez, Hubert H.; Rodriguez, Ramon L.; Malaty, Irene A.; Bowers, Dawn; Hass, Christopher J.; Katayama, Yoichi; Yamamoto, Takamitsu; Okun, Michael S.

2013-01-01

30

Parkinson’s disease DBS: what, when, who and why? The time has come to tailor DBS targets.  

PubMed

Deep brain stimulation (DBS) has recently been proven to be an effective therapy for medication refractory symptoms of Parkinson's disease. As the evidence base continues to evolve, many important issues have surfaced, including: what operation should be performed (brain target[s],unilateral vs bilateral, simultaneous vs staged); when to operate (how early is too early to intervene?), who should be operated on (disease duration, age, symptom profiles and the use of the interdisciplinary screening team); and finally, why to operate (the rationale of surgery vs medication/apomorphine pumps/duodopa pumps/stem cell trials/gene therapy trials). We will address each of these critical issues, as well make the argument that a tailored approach to DBS and DBS targeting will best serve each potential candidate. We will review the multiple peer reviewed studies and we will emphasize the recently available data from randomized DBS studies.We will argue that moving away from a single DBS target (e.g., subthalamic nucleus DBS) and a single approach to DBS methodology (e.g., bilateral simultaneous operations) is a reasonable next step for the Parkinson's disease community. Following careful interdisciplinary DBS screening, a physician-patient discussion has the potential to establish a patient-centered and symptom-specific outcome for each potential DBS candidate. The interdisciplinary DBS team can function together to formulate and to consider an optimal and tailored approach. A tailored approach will allow for the consideration of the complex and numerous variables that may contribute to a positive or negative overall DBS outcome. We will review and provide expert commentary on a potential interdisciplinary approach to selecting unilateral or alternatively bilateral subthalamic nucleus or globus pallidus internus DBS. Our approach is aimed to maximize benefit(s) and minimize risk(s) in order to best tailor therapy for an individual patient. PMID:21384698

Okun, Michael S; Foote, Kelly D

2010-12-01

31

Computational modeling of an endovascular approach to deep brain stimulation  

NASA Astrophysics Data System (ADS)

Objective. Deep brain stimulation (DBS) therapy currently relies on a transcranial neurosurgical technique to implant one or more electrode leads into the brain parenchyma. In this study, we used computational modeling to investigate the feasibility of using an endovascular approach to target DBS therapy. Approach. Image-based anatomical reconstructions of the human brain and vasculature were used to identify 17 established and hypothesized anatomical targets of DBS, of which five were found adjacent to a vein or artery with intraluminal diameter ?1 mm. Two of these targets, the fornix and subgenual cingulate white matter (SgCwm) tracts, were further investigated using a computational modeling framework that combined segmented volumes of the vascularized brain, finite element models of the tissue voltage during DBS, and multi-compartment axon models to predict the direct electrophysiological effects of endovascular DBS. Main results. The models showed that: (1) a ring-electrode conforming to the vessel wall was more efficient at neural activation than a guidewire design, (2) increasing the length of a ring-electrode had minimal effect on neural activation thresholds, (3) large variability in neural activation occurred with suboptimal placement of a ring-electrode along the targeted vessel, and (4) activation thresholds for the fornix and SgCwm tracts were comparable for endovascular and stereotactic DBS, though endovascular DBS was able to produce significantly larger contralateral activation for a unilateral implantation. Significance. Together, these results suggest that endovascular DBS can serve as a complementary approach to stereotactic DBS in select cases.

Teplitzky, Benjamin A.; Connolly, Allison T.; Bajwa, Jawad A.; Johnson, Matthew D.

2014-04-01

32

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

PubMed

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 (T(6 mm)). The heating was modeled using the maximum T(6 mm) 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. PMID:22892760

Shrivastava, Devashish; Abosch, Aviva; Hughes, John; Goerke, Ute; DelaBarre, Lance; Visaria, Rachana; Harel, Noam; Vaughan, J Thomas

2012-09-01

33

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

NASA Astrophysics Data System (ADS)

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 (T6 mm). The heating was modeled using the maximum T6 mm 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.

Shrivastava, Devashish; Abosch, Aviva; Hughes, John; Goerke, Ute; DelaBarre, Lance; Visaria, Rachana; Harel, Noam; Vaughan, J. Thomas

2012-09-01

34

Pulse-clamp technique for single neuron stimulation electrode characterization  

Microsoft Academic Search

Miniaturized electrodes, structures and devices are necessary to achieve high target selectivity during stimulation in single neuron networks, while significant charge transfer is still demanded. A reliable test method is required to evaluate charge injection capability for high resolution neural stimulation applications that demand both a large amount of charge injection and a small electrode size. A circuit designed for

A. van Ooyen; V. G. Zagolla; C. Ulrich; U. Schnakenberg

2009-01-01

35

SIROF stimulation electrode evaluation using the pulse–clamp method  

Microsoft Academic Search

Miniaturized electrodes, structures, and devices are necessary to achieve high target selectivity during stimulation in single neuron networks, while significant charge transfer is essential. A reliable test method is required to evaluate charge injection capability for neural stimulation applications that demand both a large amount of charge injection and a small electrode size. A custom made pulse-clamp circuit was employed

A. van Ooyen; V. G. Zagolla; C. Ulrich; U. Schnakenberg

2009-01-01

36

Pulse-clamp method applied to SIROF stimulation electrodes  

Microsoft Academic Search

Miniaturized electrodes, structures, and devices are necessary to achieve high target selectivity during stimulation in single neuron networks, while significant charge transfer is essential. A reliable test method is required to evaluate charge injection capability for neural stimulation applications that demand both a large amount of charge injection and a small electrode size. A custom made pulse-clamp circuit was employed

A. van Ooyen; C. Ulrich; U. Schnakenberg

2011-01-01

37

Brain shift analysis for deep brain stimulation surgery using non-rigid registration  

Microsoft Academic Search

Deep brain stimulation (DBS) surgery is a treatment for patients suffering from Parkinson's disease and other movement disorders. The success of the procedure depends on the implantation accuracy of the DBS electrode array. Surgical planning and navigation are done based on the pre-operative patient scans, assuming that brain tissues do not move from the time of the pre-operative image acquisition

Muhammad F. Khan; Klaus Mewes; Robert Gross; Oskar Skrinjar

2007-01-01

38

Hypothalamic Deep Brain Stimulation for Cluster Headache: Experience From a New Multicase Series  

Microsoft Academic Search

Deep brain stimulation (DBS) of the posterior hypothalamus was found to be effective in the treatment of drug-resistant chronic cluster headache. We report the results of a multicentre case series of six patients with chronic cluster headache in whom a DBS in the posterior hypothalamus was performed. Electrodes were implanted stereotactically in the ipsilateral posterior hypothalamus according to published coordinates

T Bartsch; MO Pinsker; D Rasche; T Kinfe; F Hertel; HC Diener; V Tronnier; HM Mehdorn; J Volkmann; G Deuschl; JK Krauss

2008-01-01

39

Chronic neural stimulation with thin-film, iridium oxide electrodes  

Microsoft Academic Search

Experiments were conducted to assess the effect of chronic stimulation on the electrical properties of the electrode-tissue system, as measured using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Silicon, micromachined probes with multiple iridium oxide stimulating electrodes (400-1600 ?m2) were implanted in guinea pig cortex. A 10-17 day post-operative recovery period was followed by five days of monopolar stimulation,

James D. Weiland; David J. Anderson

2000-01-01

40

Analysis of fractal electrodes for efficient neural stimulation  

PubMed Central

Planar electrodes are increasingly used in therapeutic neural stimulation techniques such as functional electrical stimulation, epidural spinal cord stimulation (ESCS), and cortical stimulation. Recently, optimized electrode geometries have been shown to increase the efficiency of neural stimulation by increasing the variation of current density on the electrode surface. In the present work, a new family of modified fractal electrode geometries is developed to enhance the efficiency of neural stimulation. It is shown that a promising approach in increasing the neural activation function is to increase the “edginess” of the electrode surface, a concept that is explained and quantified by fractal mathematics. Rigorous finite element simulations were performed to compute electric potential produced by proposed modified fractal geometries. The activation of 256 model axons positioned around the electrodes was then quantified, showing that modified fractal geometries required a 22% less input power while maintaining the same level of neural activation. Preliminary in vivo experiments investigating muscle evoked potentials due to median nerve stimulation showed encouraging results, supporting the feasibility of increasing neural stimulation efficiency using modified fractal geometries.

Golestanirad, Laleh; Elahi, Behzad; Molina, Alberto; Mosig, Juan R.; Pollo, Claudio; Chen, Robert; Graham, Simon J.

2013-01-01

41

Bio-heat transfer model of deep brain stimulation-induced temperature changes.  

PubMed

There is a growing interest in the use of chronic deep brain stimulation (DBS) for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. Fundamental questions remain about the physiologic effects of DBS. Previous basic research studies have focused on the direct polarization of neuronal membranes by electrical stimulation. The goal of this paper is to provide information on the thermal effects of DBS using finite element models to investigate the magnitude and spatial distribution of DBS-induced temperature changes. The parameters investigated include stimulation waveform, lead selection, brain tissue electrical and thermal conductivities, blood perfusion, metabolic heat generation during the stimulation and lead thermal conductivity/heat dissipation through the electrode. Our results show that clinical DBS protocols will increase the temperature of surrounding tissue by up to 0.8 degrees C depending on stimulation/tissue parameters. PMID:17124335

Elwassif, Maged M; Kong, Qingjun; Vazquez, Maribel; Bikson, Marom

2006-12-01

42

Bio-heat transfer model of deep brain stimulation-induced temperature changes  

NASA Astrophysics Data System (ADS)

There is a growing interest in the use of chronic deep brain stimulation (DBS) for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. Fundamental questions remain about the physiologic effects of DBS. Previous basic research studies have focused on the direct polarization of neuronal membranes by electrical stimulation. The goal of this paper is to provide information on the thermal effects of DBS using finite element models to investigate the magnitude and spatial distribution of DBS-induced temperature changes. The parameters investigated include stimulation waveform, lead selection, brain tissue electrical and thermal conductivities, blood perfusion, metabolic heat generation during the stimulation and lead thermal conductivity/heat dissipation through the electrode. Our results show that clinical DBS protocols will increase the temperature of surrounding tissue by up to 0.8 °C depending on stimulation/tissue parameters.

Elwassif, Maged M.; Kong, Qingjun; Vazquez, Maribel; Bikson, Marom

2006-12-01

43

Wire Tethering or ‘Bowstringing’ as a Long-Term Hardware-Related Complication of Deep Brain Stimulation  

Microsoft Academic Search

Background: Widely reported long-term complications following implantation of deep brain stimulation (DBS) hardware include breakage of electrode leads, internal pulse generator (IPG) failure, skin erosions and infection. Here we report on a rarely described problem that arises from formation of scar tissue adhesions around the DBS extension wire(s). Over time, this scar tissue can become tight and pronounced, protruding noticeably

Peter M. Miller; Robert E. Gross

2009-01-01

44

Improved chronic neural stimulation using high surface area platinum electrodes.  

PubMed

We report a novel nano-cluster platinum (NCPt) film that exhibits enhanced performance as an electrode material for neural stimulation applications. Nano-cluster films were deposited using a custom physical vapor deposition process and patterned on a flexible polyimide microelectrode array using semiconductor processing technology. Electrode performance was characterized in vitro using electrochemical impedance spectroscopy and compared with sputtered thinfilm platinum (TFPt) electrodes. We characterized electrode impedance, charge storage capacity, voltage transient properties, and relative surface area enhancement in vitro. Preliminary lifetime testing of the electrode reveals that the NCPt electrodes degrade more slowly than TFPt electrodes. The combination of material biocompatibility, electrochemical performance, and preliminary lifetime results point to a promising new electrode material for neural interface devices. PMID:24109995

Shah, Kedar G; Tolosa, Vanessa M; Tooker, Angela C; Felix, Sarah H; Pannu, Satinderpall S

2013-01-01

45

Complete removal of vagus nerve stimulator generator and electrodes.  

PubMed

Vagus nerve stimulation has become widely used in the palliative treatment of refractory epilepsy. Removal of a vagus nerve stimulator may be desirable or even necessary due to lack of efficacy, intolerable side effects, signs of infection, or failure of the device. Unless the lead or the helical electrodes are defective, only the generator is explanted and the electrodes are usually left behind for fear of damaging nerve or surrounding structures. The authors review their experience with complete removal of the stimulating electrodes and pacemaker-like generator device in 9 consecutive patients, 3 of whom were children. Using microsurgical techniques, the authors were able to completely remove the stimulator, including electrodes in all patients. All nerves remained morphologically intact. One case of temporary and one of permanent clinically silent ipsilateral vocal cord paresis were observed. PMID:20121370

Ortler, Martin; Unterhofer, Claudia; Dobesberger, Judith; Haberlandt, Edda; Trinka, Eugen

2010-02-01

46

Effects of STN DBS on Rigidity in Parkinson's Disease  

PubMed Central

We quantified the effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and medication on Parkinsonian rigidity using an objective measure of work about the elbow joint during a complete cycle of imposed 1-Hz sinusoidal oscillations. Resting and activated rigidity were analyzed in four experimental conditions: 1) off treatment; 2) on DBS; 3) on medication; and 4) on DBS plus medication. Rigidity at the elbow joint was also assessed using the Unified Parkinson’s Disease Rating Scale (UPDRS). We tested ten patients who received STN DBS and ten age-matched neurologically healthy control subjects. The activated rigidity condition increased work in both Parkinson’s disease (PD) patients and control subjects. In PD patients, STN DBS reduced both resting and activated rigidity as indicated by work and the UPDRS rigidity score. This is the first demonstration that STN stimulation reduces rigidity using an objective measure such as work. In contrast, the presurgery dose of antiparkinsonian medication did not significantly improve the UPDRS rigidity score and reduced work only in the activated rigidity condition. Our results suggest that STN DBS may be more effective in alleviating rigidity in the upper limb of PD patients than medications administered at presurgery dosage level.

Shapiro, Mark B.; Vaillancourt, David E.; Sturman, Molly M.; Metman, Leo Verhagen; Bakay, Roy A. E.; Corcos, Daniel M.

2008-01-01

47

High-porous platinum electrodes for functional electrical stimulation.  

PubMed

This paper reports on the preparation and characterization of highly porous platinum electrodes for functional electrical stimulation. Thin-film platinum electrodes were roughened by electrochemical deposition of platinum-copper alloys and subsequent removal of copper using cyclic voltammetry (CV). Prepared samples were characterized by electrochemical impedance spectroscopies (EIS), CVs and long-term pulse testing. The electrodes exhibited an increased porosity by a factor of ~238 when compared to sputtered platinum electrodes. EIS measurements showed a decreased impedance of about 85% and pulse tests suggested a stable coating over at least 250 million pulses. PMID:22255559

Boretius, Tim; Jurzinsky, Tilman; Koehler, Christian; Kerzenmacher, Sven; Hillebrecht, Harald; Stieglitz, Thomas

2011-01-01

48

Surface-Patterned Electrode Bioreactor for Electrical Stimulation  

PubMed Central

We present a microscale cell culture system with an interdigitated microarray of excimer-laser-ablated indium tin oxide electrodes for electrical stimulation of cultured cells. The system has been characterized in a range of geometeries and stimulation regimes via electrochemical impedance spectroscopy and used to culture primary cardiomyocytes and human adipose derived stem cells. Over 6 days of culture with electrical stimulation (2 ms duration, 1 Hz, 180 ?m wide electrodes with 200 ?m spacing), both cell types exhibited enhanced proliferation, elongation and alignment, and adipose derived stem cells exhibited higher numbers of Connexin-43-composed gap junctions.

Tandon, Nina; Marsano, Anna; Maidhof, Robert; Numata, Keiji; Montouri-Sorrentino, Chrystina; Cannizzaro, Christopher; Voldman, Joel

2013-01-01

49

Multichannel metallic electrode for threshold stimulation of frog's retina  

Microsoft Academic Search

A simple method for making a stimulating multi-channel metallic electrode is proposed. The method uses furnace-shaped multiple fine glass tubes as channel guides for inserted tungsten wires that are pulled as a unit to produce multi-channel metallic electrode with a tapered tip. By shortening the tip, the desired inter-channels distances (from tens to hundreds of micrometers) can be established with

Antanas Kuras

1997-01-01

50

Attracting retinal cells to electrodes for high-resolution stimulation  

NASA Astrophysics Data System (ADS)

Development of the electronic retinal prosthesis for restoration of sight in patients suffering from the degenerative retinal diseases faces many technological challenges. To achieve significant improvement in the low vision patients the visual acuity of 20/80 would be desirable, which corresponds to the pixel size of 20?m in the retinal implant. Stimulating current strongly (quadratically) depends on distance between electrode and cell. To achieve uniformity in stimulation thresholds, to avoid erosion of the electrodes and overheating of tissue, and to reduce the cross-talk between the neighboring pixels the neural cells should not be separated from electrodes by more than a few micrometers. Achieving such a close proximity along the whole surface of an implant is one of the major obstacles for the high resolution retinal implant. To ensure proximity of cells and electrodes we have developed a technique that prompts migration of retinal cells towards stimulating sites. The device consists of a multilayered membrane with an array of perforations of several (5-15) micrometers in diameter in which addressable electrodes can be embedded. In experiments in-vitro using explants of the whole retina of P7 rats, and in-vivo using adult rabbits and RCS rats the retinal tissue grew into the pores when membranes were positioned on the sub-retinal side. Histology has demonstrated that migrating cells preserve synaptic connections with cells outside the pores, thus allowing for signal transduction into the retina above the implant. Intimate proximity of cells to electrodes achieved with this technique allows for reduction of the stimulation current to 2?A at the 10?m electrode. A 3mm disk array with 18,000 pixels can stimulate cells with 0.5 ms pulses at 50Hz while maintaining temperature rise at the implant surface below 0.3°C. Such an implant can, in principle, provide spatial resolution geometrically corresponding to the visual acuity of 20/80 in a visual field of 10°.

Palanker, Daniel V.; Huie, Philip; Vankov, Alexander B.; Freyvert, Yev; Fishman, Harvey; Marmor, Michael F.; Blumenkranz, Mark S.

2004-07-01

51

Micrographia induced by pallidal DBS for segmental dystonia: a subtle sign of hypokinesia?  

Microsoft Academic Search

Recently parkinsonism has been reported as a rare side effect of globus pallidus internus (GPi) deep brain stimulation (DBS)\\u000a for dystonia. In the present systematic prospective study in 11 patients with segmental dystonia not affecting distal arm\\u000a function, we could demonstrate significant changes in handwriting characterized by mild micrographia following GPi-DBS. We\\u000a propose that this finding reflects GPi-DBS-induced disturbances of

Christian Blahak; Hans-Holger Capelle; Hansjoerg Baezner; Thomas M. Kinfe; Michael G. Hennerici; Joachim K. Krauss

2011-01-01

52

Multi-electrode stimulation and recording in the isolated retina.  

PubMed

As part of an exploration of the feasibility of an epi-retinal prosthesis, we developed an experimental method to electrically stimulate and record from retinal neurons using a micro-fabricated multi-electrode array. An isolated retina is placed on an array of 10 microm diameter disk electrodes with the ganglion cell side of the retina facing the electrode surfaces. The retina is bathed in oxygenated Ames' medium and warmed in order to sustain it in vitro for the duration of an experiment, typically 4-9 h. To reduce stimulus artifacts, the electrodes are grouped into two clusters - one used for stimulation and the other for recording--spaced several hundred microns apart, and electrodes are insulated with both silicon nitride and a 10 microm thick layer of polyimide. Stimuli are delivered to the array using an optically isolated current source stimulator, and the resulting responses recorded with an eight channel nerve response amplifier. Stimulation and recording are performed under computer control. A variety of physiologic measurements is described in order to illustrate the strengths and drawbacks of this method. PMID:10967359

Grumet, A E; Wyatt, J L; Rizzo, J F

2000-08-15

53

TV DBS - The space segment  

NASA Astrophysics Data System (ADS)

The electronics requirements of a Direct Broadcast Satellite (DBS) communications network ae described. Emphasis is given to the electronics payload of a proposed DBS system for the UK. Among the components described are: a 17.5 GHz MIC low-noise travelling wave tube (TWTA) amplifier; a 17-5 GHz MIC receiver; a 12 GHz channel amplifier; and a four channel high-power output multiplexer. The results of a preliminary demonstration of a 17/12 GHz transponder are presented. Black and white photographs of the electronics hardware are provided.

Mathews, D.

1986-02-01

54

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

Microsoft Academic Search

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 \\

Laurie M. O'Connor

2010-01-01

55

Effects of DBS on auditory and somatosensory processing in Parkinson's disease.  

PubMed

Motor symptoms of Parkinson's disease (PD) can be relieved by deep brain stimulation (DBS). The mechanism of action of DBS is largely unclear. Magnetoencephalography (MEG) studies on DBS patients have been unfeasible because of strong magnetic artifacts. An artifact suppression method known as spatiotemporal signal space separation (tSSS) has mainly overcome these difficulties. We wanted to clarify whether tSSS enables noninvasive measurement of the modulation of cortical activity caused by DBS. We have studied auditory and somatosensory-evoked fields (AEFs and SEFs) of advanced PD patients with bilateral subthalamic nucleus (STN) DBS using MEG. AEFs were elicited by 1-kHz tones and SEFs by electrical pulses to the median nerve with DBS on and off. Data could be successfully acquired and analyzed from 12 out of 16 measured patients. The motor symptoms were significantly relieved by DBS, which clearly enhanced the ipsilateral auditory N100m responses in the right hemisphere. Contralateral N100m responses and somatosensory P60m responses also had a tendency to increase when bilateral DBS was on. MEG with tSSS offers a novel and powerful tool to investigate DBS modulation of the evoked cortical activity in PD with high temporal and spatial resolution. The results suggest that STN-DBS modulates auditory processing in advanced PD. Hum Brain Mapp, 2011. © 2010 Wiley-Liss, Inc. PMID:20645306

Airaksinen, Katja; Mäkelä, Jyrki P; Taulu, Samu; Ahonen, Antti; Nurminen, Jussi; Schnitzler, Alfons; Pekkonen, Eero

2011-07-01

56

Psychophysical assessment of stimulation sites in auditory prosthesis electrode arrays  

Microsoft Academic Search

Auditory prostheses use implanted electrode arrays that permit stimulation at many sites along the tono- topic axis of auditory neurons. Psychophysical studies demonstrate that measures of implant function, such as detection and discrimination thresholds, vary considerably across these sites, that the across-site patterns of these measures differ across subjects, and that the likely mechanisms underlying this variabil- ity differ across

Bryan E. Pfingst; Rose A. Burkholder-Juhasz; Teresa A. Zwolan

2008-01-01

57

Deep brain stimulation for Parkinson's disease using frameless technology.  

PubMed

Abstract Historically deep brain stimulation (DBS) for Parkinson's disease (PD) has been performed by frame-based stereotaxy. However, recently the option of frameless stereotaxy has become available. This avoids the potential discomfort the patient may experience because of the frame fixed to the head. This study compared clinical outcomes of DBS performed using frame-based and frameless procedures for PD patients. Twelve patients underwent DBS operations; from these patients, six underwent frame-based and six underwent frameless DBS operations, and assessed 6 months later. Operation time, subthalamic electrode contact length, microelectrode recording (MER) tracts, and unified PD rating scale scores were evaluated and the scores were compared. This small study found no differences between frameless or frame based DBS, and concludes that framless system maybe an acceptable alternative. PMID:24138684

Cheng, Chun-Yuan; Hsing, Ming-Tai; Chen, Yung-Hsiang; Wu, Sey-Lin; Sy, Hiu Ngar; Chen, Chien-Min; Yang, Yu-Jen; Lee, Meng-Chih

2014-06-01

58

Impedance changes in chronically implanted and stimulated cochlear implant electrodes.  

PubMed

Objectives Electrode impedance increases following implantation and undergoes transitory reduction with onset of electrical stimulation. The studies in this paper measured the changes in access resistance and polarization impedance in vivo before and following electrical stimulation, and recorded the time course of these changes. Design Impedance measures recorded in (a) four cats following 6 months of cochlear implant use, and (b) three cochlear implant recipients with 1.5-5 years cochlear implant experience. Results Both the experimental and clinical data exhibited a reduction in electrode impedance, 20 and 5% respectively, within 15-30 minutes of stimulation onset. The majority of these changes occurred through reduction in polarization impedance. Cessation of stimulation was followed by an equivalent rise in impedance measures within 6-12 hours. Conclusions Stimulus-induced reductions in impedance exhibit a rapid onset and are evident in both chronic in vivo models tested, even several years after implantation. Given the impedance changes were dominated by the polarization component, these findings suggest that the electrical stimulation altered the electrode surface rather than the bulk tissue and fluid in the cochlea. PMID:23998484

Newbold, Carrie; Mergen, Silvana; Richardson, Rachael; Seligman, Peter; Millard, Rodney; Cowan, Robert; Shepherd, Robert

2014-07-01

59

MRI-guided STN DBS in Parkinson's disease without microelectrode recording: efficacy and safety  

Microsoft Academic Search

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a commonly employed therapeutic procedure for patients with Parkinson's disease uncontrolled by medical therapies. This series describes the outcomes of 79 consecutive patients that underwent bilateral STN DBS at the National Hospital for Neurology and Neurosurgery between November 2002 and November 2008 using an MRI-guided surgical technique without microelectrode recording.

T. Foltynie; L. Zrinzo; I. Martinez-Torres; E. Tripoliti; E. Petersen; E. Holl; I. Aviles-Olmos; M. Jahanshahi; M. Hariz; P. Limousin

2010-01-01

60

Anaesthetic management of shoulder arthroscopic repair in Parkinson's disease with deep brain stimulator  

PubMed Central

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.

Gandhi, Ranju; Chawla, Reeta

2014-01-01

61

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

PubMed

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. PMID:25024475

Gandhi, Ranju; Chawla, Reeta

2014-05-01

62

Parkinson's disease: recent development in therapies for advanced disease with a focus on deep brain stimulation (DBS) and duodenal levodopa infusion.  

PubMed

Effective medical treatment for Parkinson's disease has been available for almost 40 years. After several years of treatment with L-dihydroxyphenylalanine (L-dopa, levodopa), however, fluctuations often occur. The patient may then experience random variations of the motor symptoms during the day. The medication becomes increasingly complicated. New therapeutic methods, deep brain stimulation and duodenal infusion of L-dopa, have proven to be very effective in stabilizing the fluctuations. A clinical update of Parkinson's disease is presented together with a short review of these two methods. PMID:18279380

Sydow, Olof

2008-04-01

63

Regional Cerebral Perfusion Differences between Periventricular Grey, Thalamic and Dual Target Deep Brain Stimulation for Chronic Neuropathic Pain  

Microsoft Academic Search

Regional cerebral blood flow changes were evaluated in different subcortical brain targets following deep brain stimulation (DBS) for chronic pain. Three patients with intractable neuropathic pain were assessed; one had stimulating electrodes in the ventroposterolateral thalamic nucleus (VPL), one in the periventricular grey (PVG) area, and one had electrodes in both targets. Pain relief was achieved in all patients. Cerebral

Erlick A. C. Pereira; Alexander L. Green; Kevin M. Bradley; Nigel Soper; Liz Moir; John F. Stein; Tipu Z. Aziz

2007-01-01

64

Pulse-clamp technique for single neuron stimulation electrode characterization.  

PubMed

Miniaturized electrodes, structures and devices are necessary to achieve high target selectivity during stimulation in single neuron networks, while significant charge transfer is still demanded. A reliable test method is required to evaluate charge injection capability for high resolution neural stimulation applications that demand both a large amount of charge injection and a small electrode size. A circuit designed for the pulse-clamp technique was employed to characterize the electrode charge-storage capability of microelectrodes of sizes smaller than 300 microm in diameter. The circuit allows different electrodes and surface modifications to be quickly and accurately compared. Pulse-clamp measurements are performed on planar microelectrodes in 154 mM phosphate buffered saline (PBS) solution with 400 micros long pulses at charges up to 40 nC. The pulse-clamp and cyclic voltammetry results of sputtered iridium oxide film (SIROF) electrodes of different sizes show charge losses of less than 3% and a superior reversible charge injection capability compared to platinum microelectrodes of the same size, even at higher charge density levels. PMID:19964763

van Ooyen, Andre; Zagolla, Volker G; Ulrich, Christian; Schnakenberg, Uwe

2009-01-01

65

Regional Personalized Electrodes to Select Transcranial Current Stimulation Target  

PubMed Central

Rationale: Personalizing transcranial stimulations promises to enhance beneficial effects for individual patients. Objective: To stimulate specific cortical regions by developing a procedure to bend and position custom shaped electrodes; to probe the effects on cortical excitability produced when the properly customized electrode is targeting different cortical areas. Method: An ad hoc neuronavigation procedure was developed to accurately shape and place the personalized electrodes on the basis of individual brain magnetic resonance images (MRI) on bilateral primary motor (M1) and somatosensory (S1) cortices. The transcranial alternating current stimulation (tACS) protocol published by Feurra et al. (2011b) was used to test the effects on cortical excitability of the personalized electrode when targeting S1 or M1. Results: Neuronal excitability as evaluated by tACS was different when targeting M1 or S1, with the General Estimating Equation model indicating a clear tCS Effect (p?stimulating electrode. Significance: Through multimodal brain investigations continuous efforts in understanding the neuronal changes related to specific neurological or psychiatric diseases become more relevant as our ability to build the compensating interventions improves. An important step forward on this path is the ability to target the specific cortical area of interest, as shown in the present pilot work.

Tecchio, Franca; Cancelli, A.; Cottone, C.; Tomasevic, L.; Devigus, B.; Zito, G.; Ercolani, Matilde; Carducci, F.

2013-01-01

66

Electrode Positioning and Montage in Transcranial Direct Current Stimulation  

PubMed Central

Transcranial direct current stimulation (tDCS) is a technique that has been intensively investigated in the past decade as this method offers a non-invasive and safe alternative to change cortical excitability2. The effects of one session of tDCS can last for several minutes, and its effects depend on polarity of stimulation, such as that cathodal stimulation induces a decrease in cortical excitability, and anodal stimulation induces an increase in cortical excitability that may last beyond the duration of stimulation6. These effects have been explored in cognitive neuroscience and also clinically in a variety of neuropsychiatric disorders – especially when applied over several consecutive sessions4. One area that has been attracting attention of neuroscientists and clinicians is the use of tDCS for modulation of pain-related neural networks3,5. Modulation of two main cortical areas in pain research has been explored: primary motor cortex and dorsolateral prefrontal cortex7. Due to the critical role of electrode montage, in this article, we show different alternatives for electrode placement for tDCS clinical trials on pain; discussing advantages and disadvantages of each method of stimulation.

DaSilva, Alexandre F.; Volz, Magdalena Sarah; Bikson, Marom; Fregni, Felipe

2011-01-01

67

Characterizing Effects of Subthalamic Nucleus Deep Brain Stimulation on Methamphetamine-Induced Circling Behavior in Hemiparkinsonian Rats  

PubMed Central

The unilateral 6-hydroxydopamine (6-OHDA) lesioned rat model is frequently used to study the effects of subthalamic nucleus (STN) deep brain stimulation (DBS) for the treatment of Parkinson’s disease. However, systematic knowledge of the effects of DBS parameters on behavior in this animal model is lacking. The goal of this study was to characterize the effects of DBS on methamphetamine-induced circling in the unilateral 6-OHDA lesioned rat. DBS parameters tested include stimulation amplitude, stimulation frequency, methamphetamine dose, stimulation polarity, and anatomical location of the electrode. When an appropriate stimulation amplitude and dose of methamphetamine were applied, high frequency stimulation (> 130 Hz), but not low frequency stimulation (< 10 Hz), reversed the bias in ipsilateral circling without inhibiting movement. This characteristic frequency tuning profile was only generated when at least one electrode used during bipolar stimulation was located within the STN. No difference was found between bipolar stimulation and monopolar stimulation when the most effective electrode contact was selected, indicating that monopolar stimulation could be used in future experiments. Methamphetamine-induced circling is a simple, reliable, and sensitive behavioral test and holds potential for high-throughput study of the effects of STN DBS in unilaterally lesioned rats.

So, Rosa Q.; McConnell, George C.; August, Auriel T.; Grill, Warren M.

2013-01-01

68

Cognitive effects of deep brain stimulation for essential tremor: evaluation at 1 and 6 years.  

PubMed

Only a few studies have explored cognitive changes with deep brain stimulation (DBS) in patients with essential tremor (ET). Furthermore, the cognitive effects after years of electrical stimulation are unknown. Assessing the impact of stereotactic electrode implantation and the actual electrical stimulation on cognition in patients with ET in the short and long term is of interest, because DBS is increasingly applied and can offer deeper insight into human brain functions. We examined nine ET patients before surgery (PRE-SURGERY), and 1 and 6 years thereafter with DBS switched on (DBS-ON) and off (DBS-OFF). Standardized neuropsychological tests and reaction time tests were applied. There were no differences in tasks of verbal fluency, memory, and executive and intellectual functions comparing PRE-SURGERY, DBS-ON, and DBS-OFF at 1 and 6 years post-surgery. Imaging data revealed that the dorsolateral prefrontal cortex and mamillo-thalamic tracts crucial for cognitive functioning were spared by electrode implantation. Additionally, with electrodes targeting the thalamus and adjacent subthalamic area, the actual electrical stimulation did not affect neuropsychological functioning. However, lesions caused by electrode implantation led to an increase in simple reaction time, while the actual electrical stimulation restored impaired reaction time. This is the second largest study of neuropsychological functioning in patients with ET treated with DBS, and the first covering a neuropsychological long-term follow-up over 6 years. Neither stereotactic surgery nor electrical stimulation affected higher cognitive processes. This study proposes that cerebello-thalamo-cortical pathways in humans are involved in tasks of simple reaction time. PMID:23649123

Heber, Ines A; Coenen, Volker A; Reetz, Kathrin; Schulz, Jörg B; Hoellig, Anke; Fimm, Bruno; Kronenbuerger, Martin

2013-11-01

69

Effects of STN DBS on Memory Guided Force Control in Parkinson's Disease (June 2007)  

PubMed Central

This study examined the control of elbow force in nine patients with Parkinson’s disease when visual feedback was available and when visual feedback was removed to determine how medication (Meds) and unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) affect memory guided force control. Patients were examined in each of four treatment conditions: 1) off treatment; 2) Meds; 3) STN DBS; and 4) Meds plus STN DBS. With visual feedback available, there was no difference in force output across treatment conditions. When visual feedback was removed force output drifted under the target in both the off-treatment and the Meds conditions. However, when on STN DBS or Meds plus STN DBS force output drifted above the target. As such, only STN DBS had a significant effect on force output in the vision removed condition. Increased force output when on STN DBS may have occurred due to disruptions in the basal ganglia-thalamo-cortical circuitry. We suggest that modulation of output of the internal segment of the globus pallidus by STN DBS may drive the effect of STN DBS on memory guided force control.

Prodoehl, Janey; Corcos, Daniel M.; Rothwell, John C.; Metman, Leo Verhagen; Bakay, Roy A. E.; Vaillancourt, David E.

2008-01-01

70

Performance of conducting polymer electrodes for stimulating neuroprosthetics  

NASA Astrophysics Data System (ADS)

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.

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

71

Optimizing a Rodent Model of Parkinson's Disease for Exploring the Effects and Mechanisms of Deep Brain Stimulation  

PubMed Central

Deep brain stimulation (DBS) has become a treatment for a growing number of neurological and psychiatric disorders, especially for therapy-refractory Parkinson's disease (PD). However, not all of the symptoms of PD are sufficiently improved in all patients, and side effects may occur. Further progress depends on a deeper insight into the mechanisms of action of DBS in the context of disturbed brain circuits. For this, optimized animal models have to be developed. We review not only charge transfer mechanisms at the electrode/tissue interface and strategies to increase the stimulation's energy-efficiency but also the electrochemical, electrophysiological, biochemical and functional effects of DBS. We introduce a hemi-Parkinsonian rat model for long-term experiments with chronically 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.

Nowak, Karl; Mix, Eilhard; Gimsa, Jan; Strauss, Ulf; Sriperumbudur, Kiran Kumar; Benecke, Reiner; Gimsa, Ulrike

2011-01-01

72

Analysis of High-Perimeter Planar Electrodes for Efficient Neural Stimulation  

PubMed Central

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 two, three or four 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.

Wei, Xuefeng F.; Grill, Warren M.

2009-01-01

73

An Energy-Efficient, Adiabatic Electrode Stimulator With Inductive Energy Recycling and Feedback Current Regulation  

Microsoft Academic Search

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

Scott K. Arfin; Rahul Sarpeshkar

2012-01-01

74

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

NASA Astrophysics Data System (ADS)

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 from the primary site were significantly lower than 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.

Wongsarnpigoon, Amorn; Grill, Warren M.

2011-12-01

75

Outcome of Bilateral Subthalamic Nucleus Stimulation in the Treatment of Parkinson’s Disease: Correlation with Intra-Operative Multi-Unit Recordings but Not with the Type of Anaesthesia  

Microsoft Academic Search

Background: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) gained general acceptance in the treatment of Parkinson’s disease (PD). Objective: To study the clinical outcome and the predicting factors of efficacy of chronic STN stimulation, while DBS electrodes were implanted under local or general anaesthesia with intra-operative electrophysiological guidance based on multi-unit recordings. Methods: We included a large single-centre

Jean-Pascal Lefaucheur; Jean-Marc Gurruchaga; Bernard Pollin; Florian von Raison; Nabil Mohsen; Masahiro Shin; Isabelle Ménard-Lefaucheur; Satoru Oshino; Haruhiko Kishima; Gilles Fénelon; Philippe Rémy; Pierre Cesaro; Inana Gabriel; Pierre Brugičres; Yves Keravel; Jean-Paul Nguyen

2008-01-01

76

Local glutamate release in the rat ventral lateral thalamus evoked by high-frequency stimulation  

NASA Astrophysics Data System (ADS)

Thalamic deep brain stimulation (DBS) is proven therapy for essential tremor, Parkinson's disease and Tourette's syndrome. We tested the hypothesis that high-frequency electrical stimulation results in local thalamic glutamate release. Enzyme-linked glutamate amperometric biosensors were implanted in anesthetized rat thalamus adjacent to the stimulating electrode. Electrical stimulation was delivered to investigate the effect of frequency, pulse width, voltage-controlled or current-controlled stimulation, and charge balancing. Monophasic electrical stimulation-induced glutamate release was linearly dependent on stimulation frequency, intensity and pulse width. Prolonged stimulation evoked glutamate release to a plateau that subsequently decayed back to baseline after stimulation. Glutamate release was less pronounced with voltage-controlled stimulation and not present with charge balanced current-controlled stimulation. Using fixed potential amperometry in combination with a glutamate bioprobe and adjacent microstimulating electrode, the present study has shown that monophasic current-controlled stimulation of the thalamus in the anesthetized rat evoked linear increases in local extracellular glutamate concentrations that were dependent on stimulation duration, frequency, intensity and pulse width. However, the efficacy of monophasic voltage-controlled stimulation, in terms of evoking glutamate release in the thalamus, was substantially lower compared to monophasic current-controlled stimulation and entirely absent with biphasic (charge balanced) current-controlled stimulation. It remains to be determined whether similar glutamate release occurs with human DBS electrodes and similar charge balanced stimulation. As such, the present results indicate the importance of evaluating local neurotransmitter dynamics in studying the mechanism of action of DBS.

Agnesi, Filippo; Blaha, Charles D.; Lin, Jessica; Lee, Kendall H.

2010-04-01

77

Probabilistic analysis of activation volumes generated during deep brain stimulation.  

PubMed

Deep brain stimulation (DBS) is an established therapy for the treatment of Parkinson's disease (PD) and shows great promise for the treatment of several other disorders. However, while the clinical analysis of DBS has received great attention, a relative paucity of quantitative techniques exists to define the optimal surgical target and most effective stimulation protocol for a given disorder. In this study we describe a methodology that represents an evolutionary addition to the concept of a probabilistic brain atlas, which we call a probabilistic stimulation atlas (PSA). We outline steps to combine quantitative clinical outcome measures with advanced computational models of DBS to identify regions where stimulation-induced activation could provide the best therapeutic improvement on a per-symptom basis. While this methodology is relevant to any form of DBS, we present example results from subthalamic nucleus (STN) DBS for PD. We constructed patient-specific computer models of the volume of tissue activated (VTA) for 163 different stimulation parameter settings which were tested in six patients. We then assigned clinical outcome scores to each VTA and compiled all of the VTAs into a PSA to identify stimulation-induced activation targets that maximized therapeutic response with minimal side effects. The results suggest that selection of both electrode placement and clinical stimulation parameter settings could be tailored to the patient's primary symptoms using patient-specific models and PSAs. PMID:20974269

Butson, Christopher R; Cooper, Scott E; Henderson, Jaimie M; Wolgamuth, Barbara; McIntyre, Cameron C

2011-02-01

78

Threshold levels of dual electrode stimulation in cochlear implants.  

PubMed

Simultaneous stimulation on two contacts (current steering) creates intermediate pitches between the physical contacts in cochlear implants. All recent studies on current steering have focused on Most Comfortable Loudness levels and not at low stimulation levels. This study investigates the efficacy of dual electrode stimulation at lower levels, thereby focusing on the requirements to correct for threshold variations. With a current steered signal, threshold levels were determined on 4 different electrode pairs for 7 different current steering coefficients (?). This was done psychophysically in twelve postlingually deafened cochlear implant (HiRes90K, HiFocus1J) users and, in a computer model, which made use of three different neural morphologies. The analysis on the psychophysical data taking all subjects into account showed that in all conditions there was no significant difference between the threshold level of the physical contacts and the intermediate created percepts, eliminating the need for current corrections at these very low levels. The model data showed unexpected drops in threshold in the middle of the two physical contacts (both contacts equal current). Results consistent with this prediction were obtained for a subset of 5 subjects for the apical pair with wider spacing (2.2 mm). Further analysis showed that this decrease was only observed in subjects with a long duration of deafness. For current steering on adjacent contacts, the results from the psychophysical experiments were in line with the results from computational modelling. However, the dip in the threshold profile could only be replicated in the computational model with surviving peripheral processes without an unmyelinated terminal. On the basis of this result, we put forward that the majority of the surviving spiral ganglion cells in the cochlea in humans with a long duration of deafness still retain peripheral processes, but have lost their unmyelinated terminals. PMID:23695303

Snel-Bongers, Jorien; Briaire, Jeroen J; van der Veen, Erika H; Kalkman, Randy K; Frijns, Johan H M

2013-10-01

79

Reinforcement mechanisms in putamen during high frequency STN DBS: A point process study.  

PubMed

Despite a pivotal role in the motor loop, dorsolateral striatum (putamen) has been poorly studied thus far under Parkinsonian conditions and Deep Brain Stimulation (DBS). We analyze the activity of the putamen in a monkey by combining single unit recordings and point process models. The animal received DBS (30-130 Hz) in the subthalamic nucleus (STN) while at rest and recordings were acquired both before and after treatment with 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP), which induced Parkinsonian-like motor disorders. 141 neurons were collected and, for each neuron, a point process model captured DBS-evoked discharge patterns. In the normal animal, spike trains at rest had Poisson like distribution with non-stationary recurrent patterns (RPs) of period 3-7 ms and were mildly changed by low frequency (LF, i.e., < 100 Hz) DBS (i.e., < 20% of neurons affected). With high frequency (HF, i.e., 100-130 Hz) DBS, instead, up to 59% of neurons were affected, the DBS history significantly impacted the neuronal spiking propensity, and the RPs and the post-stimulus activation latency decreased. MPTP evoked inter-neuronal dependencies (INDs) at rest and, compared to normal, LF DBS of the MPTP animal increased RPs and INDs, while HF DBS elicited a faster and wider post-stimulus activation. Overall, HF DBS reduced ongoing non-stationary dynamics by regularizing the discharge patterns both in MPTP and normal putamen, while the combination of MPTP and LF DBS enhanced such dynamics. PMID:23366116

Santaniello, Sabato; Gale, John T; Montgomery, Erwin B; Sarma, Sridevi V

2012-01-01

80

Development of very large electrode arrays for epiretinal stimulation (VLARS)  

PubMed Central

Background Retinal implants have been developed to treat blindness causing retinal degenerations such as Retinitis pigmentosa (RP). The retinal stimulators are covering only a small portion of the retina usually in its center. To restore not only central vision but also a useful visual field retinal stimulators need to cover a larger area of the retina. However, large area retinal stimulators are much more difficult to implant into an eye. Some basic questions concerning this challenge should be answered in a series of experiments. Methods Large area retinal stimulators were fabricated as flexible multielectrode arrays (MEAs) using silicon technology with polyimide as the basic material for the substrate. Electrodes were made of gold covered with reactively sputtered iridium oxide. Several prototype designs were considered and implanted into enucleated porcine eyes. The prototype MEAs were also used as recording devices. Results Large area retinal stimulator MEAs were fabricated with a diameter of 12 mm covering a visual angle of 37.6° in a normal sighted human eye. The structures were flexible enough to be implanted in a folded state through an insertion nozzle. The implants could be positioned onto the retinal surface and fixated here using a retinal tack. Recording of spontaneous activity of retinal neurons was possible in vitro using these devices. Conclusions Large flexible MEAs covering a wider area of the retina as current devices could be fabricated using silicon technology with polyimide as a base material. Principal surgical techniques were established to insert such large devices into an eye and the devices could also be used for recording of retinal neural activity.

2014-01-01

81

Neural origin of evoked potentials during thalamic deep brain stimulation.  

PubMed

Closed-loop deep brain stimulation (DBS) systems could provide automatic adjustment of stimulation parameters and improve outcomes in the treatment of Parkinson's disease and essential tremor. The evoked compound action potential (ECAP), generated by activated neurons near the DBS electrode, may provide a suitable feedback control signal for closed-loop DBS. The objectives of this work were to characterize the ECAP across stimulation parameters and determine the neural elements contributing to the signal. We recorded ECAPs during thalamic DBS in anesthetized cats and conducted computer simulations to calculate the ECAP of a population of thalamic neurons. The experimental and computational ECAPs were similar in shape and had characteristics that were correlated across stimulation parameters (R(2) = 0.80-0.95, P < 0.002). The ECAP signal energy increased with larger DBS amplitudes (P < 0.0001) and pulse widths (P < 0.002), and the signal energy of secondary ECAP phases was larger at 10-Hz than at 100-Hz DBS (P < 0.002). The computational model indicated that these changes resulted from a greater extent of neural activation and an increased synchronization of postsynaptic thalamocortical activity, respectively. Administration of tetrodotoxin, lidocaine, or isoflurane abolished or reduced the magnitude of the experimental and computational ECAPs, glutamate receptor antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and D(-)-2-amino-5-phosphonopentanoic acid (APV) reduced secondary ECAP phases by decreasing postsynaptic excitation, and the GABAA receptor agonist muscimol increased the latency of the secondary phases by augmenting postsynaptic hyperpolarization. This study demonstrates that the ECAP provides information about the type and extent of neural activation generated during DBS, and the ECAP may serve as a feedback control signal for closed-loop DBS. PMID:23719207

Kent, Alexander R; Grill, Warren M

2013-08-01

82

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

PubMed

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

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

2012-01-01

83

Hypothalamic Deep Brain Stimulation Reduces Weight Gain in an Obesity-Animal Model  

PubMed Central

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.

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

2012-01-01

84

MEG Can Map Short and Long-Term Changes in Brain Activity following Deep Brain Stimulation for Chronic Pain  

PubMed Central

Deep brain stimulation (DBS) has been shown to be clinically effective for some forms of treatment-resistant chronic pain, but the precise mechanisms of action are not well understood. Here, we present an analysis of magnetoencephalography (MEG) data from a patient with whole-body chronic pain, in order to investigate changes in neural activity induced by DBS for pain relief over both short- and long-term. This patient is one of the few cases treated using DBS of the anterior cingulate cortex (ACC). We demonstrate that a novel method, null-beamforming, can be used to localise accurately brain activity despite the artefacts caused by the presence of DBS electrodes and stimulus pulses. The accuracy of our source localisation was verified by correlating the predicted DBS electrode positions with their actual positions. Using this beamforming method, we examined changes in whole-brain activity comparing pain relief achieved with deep brain stimulation (DBS ON) and compared with pain experienced with no stimulation (DBS OFF). We found significant changes in activity in pain-related regions including the pre-supplementary motor area, brainstem (periaqueductal gray) and dissociable parts of caudal and rostral ACC. In particular, when the patient reported experiencing pain, there was increased activity in different regions of ACC compared to when he experienced pain relief. We were also able to demonstrate long-term functional brain changes as a result of continuous DBS over one year, leading to specific changes in the activity in dissociable regions of caudal and rostral ACC. These results broaden our understanding of the underlying mechanisms of DBS in the human brain.

Mohseni, Hamid R.; Smith, Penny P.; Parsons, Christine E.; Young, Katherine S.; Hyam, Jonathan A.; Stein, Alan; Stein, John F.; Green, Alexander L.; Aziz, Tipu Z.; Kringelbach, Morten L.

2012-01-01

85

The Effects of Concentric Ring Electrode Electrical Stimulation on Rat Skin  

Microsoft Academic Search

Surface electrodes are commonly used electrodes clinically, in applications such as functional electrical stimulation for\\u000a the restoration of motor functions, pain relief, transcutaneous electrical nerve stimulation, electrocardiographic monitoring,\\u000a defibrillation, surface cardiac pacing, and advanced drug delivery systems. Common to these applications are occasional reports\\u000a of pain, tissue damage, rash, or burns on the skin at the point where electrodes are

W. Besio; V. Sharma; J. Spaulding

2010-01-01

86

Pitch ranking with nonsimultaneous dual-electrode electrical stimulation of the cochlea.  

PubMed

It has already been established that simultaneous activation of two intracochlear electrodes can evoke a pitch percept which is intermediate to that of either electrode when activated by itself. In the present study, this result has been extended to nonsimultaneous activation of nearby electrodes. Pitch perception was investigated for electric stimuli presented on one or two intracochlear electrode pairs. All stimuli were pulse trains of period 4 ms. In the dual-electrode stimuli, each period contained two biphasic pulses, separated by 0.4 ms, with one pulse for each electrode pair. These stimuli were compared with loudness-balanced single-electrode stimuli, having one pulse per period, generated on the same electrode pairs. Their pitches were ranked in a two-alternative forced-choice procedure by five experienced users of the 22-electrode implant manufactured by Cochlear Pty Limited. The studies showed that the pitch of a dual-electrode stimulus was intermediate to, and moved monotonically between, those of the component electrode pairs as the relative currents were altered in an orderly fashion. Intermediate pitches were achieved in all subjects at a range of cochlear positions, for electrode separations generally up to 3 mm. In half the cases a significantly different intermediate pitch could be created between adjacent electrodes. Further studies are necessary to establish whether intermediate pitches can be obtained at larger separations, as for simultaneous stimulation, and how they are affected by other factors such as the time between pulses or the spatial extent of the stimulation. PMID:8064018

McDermott, H J; McKay, C M

1994-07-01

87

Brain Stimulation in Neurology and Psychiatry  

PubMed Central

Feedback control of deep brain stimulation (DBS) in Parkinson's disease has great potential to improve efficacy, reduce side effects, and decrease the cost of treatment. In this, the timing and intensity of stimulation are titrated according to biomarkers that capture current clinical state. Stimulation may be at standard high frequency or intelligently patterned to directly modify specific pathological rhythms. The search for and validation of appropriate feedback signals are therefore crucial. Signals recorded from the DBS electrode currently appear to be the most promising source of feedback. In particular, beta-frequency band oscillations in the local field potential recorded at the stimulation target may capture variation in bradykinesia and rigidity across patients, but this remains to be confirmed within patients. Biomarkers that reliably reflect other impairments, such as tremor, also need to be established. Finally, whether brain signals are causally important needs to be established before stimulation can be specifically patterned rather than delivered at empirically defined high frequency.

Little, Simon; Brown, Peter

2012-01-01

88

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

PubMed Central

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.

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

89

Characteristics of electrode impedance and stimulation efficacy of a chronic cortical implant using novel annulus electrodes in rat motor cortex  

NASA Astrophysics Data System (ADS)

Objective. Cortical neural prostheses with implanted electrode arrays have been used to restore compromised brain functions but concerns remain regarding their long-term stability and functional performance. Approach. Here we report changes in electrode impedance and stimulation thresholds for a custom-designed electrode array implanted in rat motor cortex for up to three months. Main Results. The array comprises four 2000 µm long electrodes with a large annular stimulating surface (7860-15700 µm2) displaced from the penetrating insulated tip. Compared to pre-implantation in vitro values there were three phases of impedance change: (1) an immediate large increase of impedance by an average of two-fold on implantation; (2) a period of continued impedance increase, albeit with considerable variability, which reached a peak at approximately four weeks post-implantation and remained high over the next two weeks; (3) finally, a period of 5-6 weeks when impedance stabilized at levels close to those seen immediately post-implantation. Impedance could often be temporarily decreased by applying brief trains of current stimulation, used to evoke motor output. The stimulation threshold to induce observable motor behaviour was generally between 75-100 µA, with charge density varying from 48-128 µC cm-2, consistent with the lower current density generated by electrodes with larger stimulating surface area. No systematic change in thresholds occurred over time, suggesting that device functionality was not compromised by the factors that caused changes in electrode impedance. Significance. The present results provide support for the use of annulus electrodes in future applications in cortical neural prostheses.

Wang, Chun; Brunton, Emma; Haghgooie, Saman; Cassells, Kahli; Lowery, Arthur; Rajan, Ramesh

2013-08-01

90

BIT-SLICE DBS digital signal processor  

NASA Astrophysics Data System (ADS)

This paper introduces the DBS (Doppler beam sharpening) digital signal processor. A high speed multiplier and the Am2900 family are used to make up the processor's hardware, which is controlled by a microprogram. The design ideas, logic functions and characteristics of the arithmetic unit and the microprogram control unit are described in detail. This system has high speed operation, perfect function and flexible logical structure. Thus, a large number of operations and processes desired by DBS imagery can be completed in real-time. The time needed for a 32-point complex FFT is less than 40 microsec.

Xie, Chunwei; Chen, Rong

91

Deep brain stimulation of the subthalamic nucleus increases premature responding in a rat gambling task.  

PubMed

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is a treatment option for the motor symptoms of Parkinson's disease (PD). However, several recent studies have found an association between STN-DBS and increased impulsivity. Currently, it is not clear whether the observed increase in impulsivity results from STN-DBS per se, or whether it involves an interaction with the underlying PD neuropathology and/or intake of dopaminergic drugs. We investigated the effects of STN-DBS on performance of intact rats on two tasks measuring impulsive responding: a novel rat gambling task (rGT) and a differential reinforcement of low rate responding (DRL20s) schedule. Following initial behavioural training, animals received electrode implantation into the STN (n=24) or sham surgery (n=24), and were re-tested on their assigned behavioural task, with or without STN-DBS. Bilateral STN-DBS administered for two hours immediately prior to testing, had no effects on rGT choice behaviour or on DRL response inhibition (p>0.05). However, STN-DBS significantly increased premature responding in the rGT task (p=0.0004), an effect that took several sessions to develop and persisted in subsequent trials when no stimulation was given. Consistent with the notion of distinct facets of impulsivity with unique neurochemical underpinnings, we observed differential effects of STN-DBS in the two tasks employed. These results suggest that STN-DBS in the absence of parkinsonism may not lead to a general loss of inhibitory control, but may instead affect impulsivity under specific conditions. PMID:23434606

Aleksandrova, Lily R; Creed, Meaghan C; Fletcher, Paul J; Lobo, Daniela S S; Hamani, Clement; Nobrega, José N

2013-05-15

92

Predicting the effects of deep brain stimulation with diffusion tensor based electric field models.  

PubMed

Deep brain stimulation (DBS) is an established therapy for the treatment of movement disorders, and has shown promising results for the treatment of a wide range of other neurological disorders. However, little is known about the mechanism of action of DBS or the volume of brain tissue affected by stimulation. We have developed methods that use anatomical and diffusion tensor MRI (DTI) data to predict the volume of tissue activated (VTA) during DBS. We co-register the imaging data with detailed finite element models of the brain and stimulating electrode to enable anatomically and electrically accurate predictions of the spread of stimulation. One critical component of the model is the DTI tensor field that is used to represent the 3-dimensionally anisotropic and inhomogeneous tissue conductivity. With this system we are able to fuse structural and functional information to study a relevant clinical problem: DBS of the subthalamic nucleus for the treatment of Parkinsons disease (PD). Our results show that inclusion of the tensor field in our model caused significant differences in the size and shape of the VTA when compared to a homogeneous, isotropic tissue volume. The magnitude of these differences was proportional to the stimulation voltage. Our model predictions are validated by comparing spread of predicted activation to observed effects of oculomotor nerve stimulation in a PD patient. In turn, the 3D tissue electrical properties of the brain play an important role in regulating the spread of neural activation generated by DBS. PMID:17354801

Butson, Christopher R; Cooper, Scott E; Henderson, Jaimie M; McIntyre, Cameron C

2006-01-01

93

Olfactory hallucinations elicited by electrical stimulation via subdural electrodes: Effects of direct stimulation of olfactory bulb and tract  

PubMed Central

In 1954, Penfield and Jasper briefly described that percepts of unpleasant odor were elicited by intraoperative electrical stimulation of the olfactory bulb in patients with epilepsy. Since then, few peer-reviewed studies have reported such phenomena elicited by stimulation mapping via subdural electrodes implanted on the ventral surface of frontal lobe. Here, we determined what types of olfactory hallucinations could be reproduced by such stimulation in children with focal epilepsy. This study included 16 children (age range: 5 to 17 years), who underwent implantation of subdural electrodes to localize the presumed epileptogenic zone and eloquent areas. Pairs of electrodes were electrically stimulated and clinical responses were observed. In case a patient reported a perception, she/he was asked to describe its nature. We also described the stimulus parameters to elicit a given symptom. Eleven patients reported a perception of smell in response to electrical stimulation while the remaining five did not. Nine patients perceived an unpleasant smell (like bitterness, smoke, or garbage), while two perceived a pleasant smell (like strawberry or good food). Such olfactory hallucinations were induced by stimulation proximal to the olfactory bulb or tract on either hemisphere but not by that of orbitofrontal gyri lateral to the medial orbital sulci. The range of stimulus parameters employed to elicit olfactory hallucinations was comparable to those for other sensorimotor symptoms. Our systematic study of epileptic children replicated stimulation-induced olfactory hallucinations. We failed to provide evidence that a positive olfactory perception could be elicited by conventional stimulation of secondary olfactory cortex alone.

Kumar, Gogi; Juhasz, Csaba; Sood, Sandeep; Asano, Eishi

2012-01-01

94

Effects of Anterior Thalamic Nucleus Deep Brain Stimulation in Chronic Epileptic Rats  

PubMed Central

Deep brain stimulation (DBS) has been investigated for the treatment of epilepsy. In rodents, an increase in the latency for the development of seizures and status epilepticus (SE) has been reported in different animal models but the consequences of delivering stimulation to chronic epileptic animals have not been extensively addressed. We study the effects of anterior thalamic nucleus (AN) stimulation at different current intensities in rats rendered epileptic following pilocarpine (Pilo) administration. Four months after Pilo-induced SE, chronic epileptic rats were bilaterally implanted with AN electrodes or had sham-surgery. Stimulation was delivered for 6 h/day, 5 days/week at 130 Hz, 90 µsec. and either 100 µA or 500 µA. The frequency of spontaneous recurrent seizures in animals receiving stimulation was compared to that recorded in the preoperative period and in rats given sham treatment. To investigate the effects of DBS on hippocampal excitability, brain slices from animals receiving AN DBS or sham surgery were studied with electrophysiology. We found that rats treated with AN DBS at 100 µA had a 52% non-significant reduction in the frequency of seizures as compared to sham-treated controls and 61% less seizures than at baseline. Animals given DBS at 500 µA had 5.1 times more seizures than controls and a 2.8 fold increase in seizure rate as compared to preoperative values. In non-stimulated controls, the average frequency of seizures before and after surgery remained unaltered. In vitro recordings have shown that slices from animals previously given DBS at 100 µA had a longer latency for the development of epileptiform activity, shorter and smaller DC shifts, and a smaller spike amplitude compared to non-stimulated controls. In contrast, a higher spike amplitude was recorded in slices from animals given AN DBS at 500 µA.

Amorim, Beatriz; Cavarsan, Clarissa; Miranda, Maisa Ferreira; Aarao, Mayra C.; Madureira, Ana Paula; Rodrigues, Antonio M.; Nobrega, Jose N.; Mello, Luiz E.; Hamani, Clement

2014-01-01

95

Activation of retinal ganglion cells following epiretinal electrical stimulation with hexagonally arranged bipolar electrodes  

NASA Astrophysics Data System (ADS)

We investigated retinal ganglion cell (RGC) responses to epiretinal electrical stimulation delivered by hexagonally arranged bipolar (Hex) electrodes, in order to assess the feasibility of this electrode arrangement for future retinal implant devices. In vitro experiments were performed using rabbit retinal preparations, with results compared to a computational model of axonal stimulation. Single-unit RGC responses to electrical stimulation were recorded with extracellular microelectrodes. With 100 µs/phase biphasic pulses, the threshold charge densities were 24.0 ± 11.2 and 7.7 ± 3.2 µC cm-2 for 50 and 125 µm diameter Hex electrodes, respectively. Threshold profiles and response characteristics strongly suggested that RGC axons were the neural activation site. Both the model and in vitro data indicated that localized tissue stimulation is achieved with Hex electrodes.

Abramian, Miganoosh; Lovell, Nigel H.; Morley, John W.; Suaning, Gregg J.; Dokos, Socrates

2011-06-01

96

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

PubMed

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

Guyton, D L; Hambrecht, F T

1973-07-01

97

Determination of optimal electrode positions for transcranial direct current stimulation (tDCS)  

Microsoft Academic Search

The present study introduces a new approach to determining optimal electrode positions in transcranial direct current stimulation (tDCS). Electric field and 3D conduction current density were analyzed using 3D finite element method (FEM) formulated for a dc conduction problem. The electrode positions for minimal current injection were optimized by changing the Cartesian coordinate system into the spherical coordinate system and

Chang-Hwan Im; Hui-Hun Jung; Jung-Do Choi; Soo Yeol Lee; Ki-Young Jung

2008-01-01

98

Simulation of Nerve Bundle Activation by Simultaneous Multipoint Extracellular Stimulation with Surface Electrodes  

NASA Astrophysics Data System (ADS)

Neural prostheses for restoring lost functions can benefit from selective activation of nerves. We had previously proposed a multiple gating stimulation, which can selectively activate a desired portion of nerve bundle, irrespective of a density of the electrode. In this paper, we discuss the design of electrode array and effective strategies to determine the stimulus parameters. A large electrode was less affected by the relative location of electrodes and the node of Ranvier, suggesting that a rectangular electrode, whose long side along a nerve bundle is longer than the internodal distance, i.e., on the order of 1 mm, would be more effective rather than a disk electrode. We could estimate an appropriate current at each electrode was a blocking threshold. For the lateral gating stimulation, the gate current should be set above the threshold, while, for depth-wise gating stimulation, the gate current should be set below the threshold. The spatial resolution of lateral gating stimulation is theoretically estimated at least at 50 ?m when the grid of array was 1.2 mm, and that of depth-wise gating stimulation at 50 ?m.

Takahashi, Hirokazu; Nakao, Masayuki; Kaga, Kimitaka

99

Comparison of neural damage induced by electrical stimulation with faradaic and capacitor electrodes.  

PubMed

Arrays of platinum (faradaic) and anodized, sintered tantalum pentoxide (capacitor) electrodes were implanted bilaterally in the subdural space of the parietal cortex of the cat. Two weeks after implantation both types of electrodes were pulsed for seven hours with identical waveforms consisting of controlled-current, charge-balanced, symmetric, anodic-first pulse pairs, 400 microseconds/phase and a charge density of 80-100 microC/cm2 (microcoulombs per square cm) at 50 pps (pulses per second). One group of animals was sacrificed immediately following stimulation and a second smaller group one week after stimulation. Tissues beneath both types of pulsed electrodes were damaged, but the difference in damage for the two electrode types was not statistically significant. Tissue beneath unpulsed electrodes was normal. At the ultrastructural level, in animals killed immediately after stimulation, shrunken and hyperchromic neurons were intermixed with neurons showing early intracellular edema. Glial cells appeared essentially normal. In animals killed one week after stimulation most of the damaged neurons had recovered, but the presence of shrunken, vacuolated and degenerating neurons showed that some of the cells were damaged irreversibly. It is concluded that most of the neural damage from stimulations of the brain surface at the level used in this study derives from processes associated with passage of the stimulus current through tissue, such as neuronal hyperactivity rather than electrochemical reactions associated with current injection across the electrode-tissue interface, since such reactions occur only with the faradaic electrodes. PMID:3189974

McCreery, D B; Agnew, W F; Yuen, T G; Bullara, L A

1988-01-01

100

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

PubMed Central

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.

2012-01-01

101

Nano-Ampere Stimulation Window for Cultured Neurons on Micro-Electrode Arrays.  

National Technical Information Service (NTIS)

From experiments, it appears to be possible to stimulate a neuron by depolarization of the lower membrane patch, the sealing part of the membrane, using a nano-ampere current through the extracellular electrode, Also, a stimulation window is observed, The...

J. R. Buitenweg W. L. Rutten E. Marani

2001-01-01

102

Intracranial electrode implantation produces regional neuroinflammation and memory deficits in rats  

SciTech Connect

Deep brain stimulation (DBS) is an established treatment for advanced Parkinson's disease (PD). The procedure entails intracranial implantation of an electrode in a specific brain structure followed by chronic stimulation. Although the beneficial effects of DBS on motor symptoms in PD are well known, it is often accompanied by cognitive impairments, the origin of which is not fully understood. To explore the possible contribution of the surgical procedure itself, we studied the effect of electrode implantation in the subthalamic nucleus (STN) on regional neuroinflammation and memory function in rats implanted bilaterally with stainless steel electrodes. Age-matched sham and intact rats were used as controls. Brains were removed 1 or 8 weeks post-implantation and processed for in vitro autoradiography with [(3)H]PK11195, an established marker of microglial activation. Memory function was assessed by the novel object recognition test (ORT) before surgery and 2 and 8 weeks after surgery. Electrode implantation produced region-dependent changes in ligand binding density in the implanted brains at 1 as well as 8 weeks post-implantation. Cortical regions showed more intense and widespread neuroinflammation than striatal or thalamic structures. Furthermore, implanted animals showed deficits in ORT performance 2 and 8 weeks post-implantation. Thus, electrode implantation resulted in a widespread and persistent neuroinflammation and sustained memory impairment. These results suggest that the insertion and continued presence of electrodes in the brain, even without stimulation, may lead to inflammation-mediated cognitive deficits in susceptible individuals, as observed in patients treated with DBS.

Kuttner-Hirshler, Y.; Biegon, A.; Kuttner-Hirshler, Y.; Polat, U.; Biegon, A.

2009-12-21

103

A versatile all-channel stimulator for electrode arrays, with real-time control  

PubMed Central

Over the last few decades, technology to record through ever increasing numbers of electrodes has become available to electrophysiologists. For the study of distributed neural processing, however, the ability to stimulate through equal numbers of electrodes, and thus to attain bidirectional communication, is of paramount importance. Here, we present a stimulation system for multi-electrode arrays which interfaces with existing commercial recording hardware, and allows stimulation through any electrode in the array, with rapid switching between channels. The system is controlled through real-time Linux, making it extremely flexible: stimulation sequences can be constructed on-the-fly, and arbitrary stimulus waveforms can be used if desired. A key feature of this design is that it can be readily and inexpensively reproduced in other labs, since it interfaces to standard PC parallel ports and uses only off-the-shelf components. Moreover, adaptation for use with in vivo multi-electrode probes would be straightforward. In combination with our freely available data-acquisition software, MeaBench, this system can provide feedback stimulation in response to recorded action potentials within 15 ms.

Wagenaar, Daniel A; Potter, Steve M

2008-01-01

104

Quasi-Monopolar Stimulation: A Novel Electrode Design Configuration for Performance Optimization of a Retinal Neuroprosthesis  

PubMed Central

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 mapping in a visual prosthesis, while maintaining low power consumption.

Khalili Moghadam, Gita; Wilke, Robert; Suaning, Gregg J.; Lovell, Nigel H.; Dokos, Socrates

2013-01-01

105

Effects of subthalamic stimulation on speech of consecutive patients with Parkinson disease  

PubMed Central

Objective: Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for advanced Parkinson disease (PD). Following STN-DBS, speech intelligibility can deteriorate, limiting its beneficial effect. Here we prospectively examined the short- and long-term speech response to STN-DBS in a consecutive series of patients to identify clinical and surgical factors associated with speech change. Methods: Thirty-two consecutive patients were assessed before surgery, then 1 month, 6 months, and 1 year after STN-DBS in 4 conditions on- and off-medication with on- and off-stimulation using established and validated speech and movement scales. Fifteen of these patients were followed up for 3 years. A control group of 12 patients with PD were followed up for 1 year. Results: Within the surgical group, speech intelligibility significantly deteriorated by an average of 14.2% ± 20.15% off-medication and 16.9% ± 21.8% on-medication 1 year after STN-DBS. The medical group deteriorated by 3.6% ± 5.5% and 4.5% ± 8.8%, respectively. Seven patients showed speech amelioration after surgery. Loudness increased significantly in all tasks with stimulation. A less severe preoperative on-medication motor score was associated with a more favorable speech response to STN-DBS after 1 year. Medially located electrodes on the left STN were associated with a significantly higher risk of speech deterioration than electrodes within the nucleus. There was a strong relationship between high voltage in the left electrode and poor speech outcome at 1 year. Conclusion: The effect of STN-DBS on speech is variable and multifactorial, with most patients exhibiting decline of speech intelligibility. Both medical and surgical issues contribute to deterioration of speech in STN-DBS patients. Classification of evidence: This study provides Class III evidence that STN-DBS for PD results in deterioration in speech intelligibility in all combinations of medication and stimulation states at 1 month, 6 months, and 1 year compared to baseline and to control subjects treated with best medical therapy.

Zrinzo, L.; Martinez-Torres, I.; Frost, E.; Pinto, S.; Foltynie, T.; Holl, E.; Petersen, E.; Roughton, M.; Hariz, M.I.; Limousin, P.

2011-01-01

106

Individualized current-shaping reduces DBS-induced dysarthria in patients with essential tremor  

PubMed Central

Objective: To investigate in patients with essential tremor (ET) treated with thalamic/subthalamic deep brain stimulation (DBS) whether stimulation-induced dysarthria (SID) can be diminished by individualized current-shaping with interleaving stimulation (cs-ILS) while maintaining tremor suppression (TS). Methods: Of 26 patients screened, 10 reported SID and were invited for testing. TS was assessed by the Tremor Rating Scale and kinematic analysis of postural and action tremor. SID was assessed by phonetic and logopedic means. Additionally, patients rated their dysarthria on a visual analog scale. Results: In 6 of the 10 patients with ET, DBS-ON (relative to DBS-OFF) led to SID while tremor was successfully reduced. When comparing individualized cs-ILS with a non–current-shaped interleaving stimulation (ILS) in these patients, there was no difference in TS while 4 of the 6 patients showed subjective improvement of speech during cs-ILS. Phonetic analysis (ILS vs cs-ILS) revealed that during cs-ILS there was a reduction of voicing during the production of voiceless stop consonants and also a trend toward an improvement in oral diadochokinetic rate, reflecting less dysarthria. Logopedic rating showed a trend toward deterioration in the diadochokinesis task when comparing ON with OFF but no difference between ILS and cs-ILS. Conclusion: This is a proof-of-principle evaluation of current-shaping in patients with ET treated with thalamic/subthalamic DBS and experiencing SID. Data suggest a benefit on SID from individual shaping of current spread while TS is preserved. Classification of evidence: This study provides Class IV evidence that in patients with ET treated with DBS with SID, individualized cs-ILS reduces dysarthria while maintaining tremor control.

Dembek, Till A.; Becker, Johannes; Raethjen, Jan; Hartinger, Mariam; Meister, Ingo G.; Runge, Matthias; Maarouf, Mohammad; Fink, Gereon R.; Timmermann, Lars

2014-01-01

107

Effect of electrode surface area on thresholds for AC stimulation and ventricular fibrillation.  

PubMed

Unintended, weak AC stimulation (leakage currents) from medical devices can cause blood pressure collapse and ventricular fibrillation (VF), potentially even death. Yet, little is understood about AC cardiac stimulation. The objective of this paper is to establish the relationship between the stimulation and VF thresholds for electrode size and stimulation frequency. Twenty-four retired male breeder guinea pigs were anesthetized with isoflurane, a tracheotomy and thoracotomy were performed, and vitals were monitored using the lead II ECG and an optical plethysmograph. The circular flat ends of eleven stainless steel rods were used as electrodes with areas ranging from 0.1 to 26.79 mm2. In the first study, 60-Hz AC stimuli of 5 s duration were delivered with strengths from 25-3000 microA or until VF was induced. In the second group, the current thresholds at 20, 40, 80, and 160 Hz were determined at electrode areas of 0.2, 2.01, and 16.4 mm2. Reactions were categorized as having no effect, having some effect (EFFECT, typically blood pressure collapse), and inducing VF. On a log-log scale, electrode radii had a piecewise-linear relationship with the current thresholds for EFFECT (p < 0.005) and VF (p < 0.01). The liminal area determined by the piecewise-linear fit was 2.0 and 2.84 mm2 for EFFECT and VF, respectively. Above the liminal area, the threshold increased proportional to r(1.25) and r(0.95) (r = radius of electrode), for EFFECT and VF, respectively. Based on these experimental results, we present a theoretical framework to explain the electrode size-stimulation threshold variation for both low strength AC stimulation and VF initiation. PMID:17926681

Patel, Shivani Govind; Malkin, Robert A

2007-10-01

108

Multi-electrode stimulation in somatosensory cortex increases probability of detection  

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

109

Linear electrode arrays for stimulation and recording within cardiac tissue space constants.  

PubMed

In this paper, we document a fabrication process that yields linear arrays of rectangular platinum black electrodes spaced 25 mum apart with edge-to-edge separation of 20 microm. The spatial arrangement is therefore sufficiently fine to insure stimulation and recording within cardiac tissue space constants, as six electrodes with dimensions of either 5 x 100 microm2, 5 x 250 microm2, or 5 x 500 microm2 were positioned in a 130-microm2 span in the arrays. Despite the small electrode sizes and available surface areas, favorable impedance characteristics were identifed. Averages ranged from 111 kOmega to 146 kOmega at 0.5 Hz and from 14 kOmega 39 kOmega at 500 Hz. Differences in impedances between the electrode sizes tested were small. Potential differences (deltaphis) recorded using the two central electrodes during stimulation with combinations at separations of only 75 microm, 100 microm, and 125 microm had low signal noise. As a preliminary test of the use of these arrays for possible application to impedance measurements in cardiac tissue, the deltaphis recorded during stimulation were compared to deltaphis obtained from finite-difference simulations using an isotropic volume conductor model. Anticipated decays in deltaphi with widening electrode separation identified in those simulations matched the decays in the recorded deltaphis closely. These findings are significant because they suggest intracellular and interstitial microimpedance mesurements in heart experiments will be straightforward. PMID:18390332

Pollard, Andrew E; Ellis, Charles D; Smith, William M

2008-04-01

110

A Lithographically-Patterned, Elastic Multi-electrode Array for Surface Stimulation of the Spinal Cord  

PubMed Central

A new, scalable process for microfabrication of a silicone-based, elastic multi-electrode array (MEA) is presented. The device is constructed by spinning poly(dimethylsiloxane) (PDMS) silicone elastomer onto a glass slide, depositing and patterning gold to construct wires and electrodes, spinning on a second PDMS layer, and then micropatterning the second PDMS layer to expose electrode contacts. The micropatterning of PDMS involves a custom reactive ion etch (RIE) process that preserves the underlying gold thin film. Once completed, the device can be removed from the glass slide for conformal interfacing with neural tissue. Prototype MEAs feature electrodes smaller than those known to be reported on silicone substrate (60 ?m diameter exposed electrode area) and were capable of selectively stimulating the surface of the in vitro isolated spinal cord of the juvenile rat. Stretchable serpentine traces were also incorporated into the functional PDMS-based MEA, and their implementation and testing is described.

Meacham, Kathleen W.; Giuly, Richard J.; Guo, Liang; Hochman, Shawn; DeWeerth, Stephen P.

2008-01-01

111

Chronic pedunculopontine nucleus stimulation restores functional connectivity.  

PubMed

The mechanisms of deep brain stimulation (DBS) are poorly understood. Earlier, high-frequency DBS has been thought to represent a depolarization block of the target area and low-frequency stimulation has been thought to 'drive' neuronal activity. We investigated the long-term effect of low-frequency DBS in a longitudinal imaging study of a patient who received bilateral pedunculopontine nucleus stimulation. We used the diffusion tensor imaging techniques including probabilistic tractography and topographic mapping to analyze long-term changes in connectivity with low-frequency DBS. Post-DBS connectivity analysis suggested a normalization of pathological pedunculopontine nucleus connectivity with DBS therapy. These findings may help elucidate the mechanisms of DBS, suggesting neuroplasticity involving a reorganization of target connectivity long term. This is the first reported case showing neuroimaging evidence of neuroplasticity after low-frequency DBS. PMID:20926975

Schweder, Patrick M; Joint, Carole; Hansen, Peter C; Green, Alexander L; Quaghebeur, Gerardine; Aziz, Tipu Z

2010-12-01

112

Sulfonated polyaniline-based organic electrodes for controlled electrical stimulation of human osteosarcoma cells.  

PubMed

Electrically conducting polymers (CPs) were found to stimulate various cell types such as neurons, osteoblasts, and fibroblasts in both in vitro and in vivo studies. However, to our knowledge, no studies have been reported on the utility of CPs in stimulation of cancer or tumor cells in the literature. Here we report a facile fabrication method of self-doped sulfonated polyaniline (SPAN)-based interdigitated electrodes (IDEs) for controlled electrical stimulation of human osteosarcoma (HOS) cells. Increased degree of sulfonation was found to increase the SPAN conductivity, which in turn improved the cell attachment and cell growth without electrical stimulation. However, an enhanced cell growth was observed under controlled electrical (AC) stimulation at low applied voltage and frequency (?800 mV and ?1 kHz). The cell growth reached a maximum threshold at an applied voltage or frequency and beyond which pronounced cell death was observed. We believe that these organic electrodes may find utility in electrical stimulation of cancer or tumor cells for therapy and research and may also provide an alternative to the conventional metal-based electrodes. PMID:23600698

Min, Yong; Yang, Yanyin; Poojari, Yadagiri; Liu, Yidong; Wu, Jen-Chieh; Hansford, Derek J; Epstein, Arthur J

2013-06-10

113

Pedunculopontine nucleus evoked potentials from subthalamic nucleus stimulation in Parkinson's disease.  

PubMed

The effects of subthalamic nucleus (STN) stimulation on the pedunculopontine nucleus area (PPNR) evoked activities were examined in two patients with Parkinson's disease. The patients had previously undergone bilateral STN deep brain stimulation (DBS) and subsequently received unilateral DBS electrodes in the PPNR. Evoked potentials were recorded from the local field potentials (LFP) from the PPNR with STN stimulation at different frequencies and bipolar contacts. Ipsilateral and contralateral short latency (<2ms) PPNR responses were evoked from left but not from right STN stimulation. In both patients, STN stimulation evoked contralateral PPNR responses at medium latencies between 41 and 45ms. Cortical evoked potentials to single pulse STN stimulation were observed at latencies between 18 and 27ms. These results demonstrate a functional connection between the STN and the PPNR. It likely involves direct projections between the STN and PPNR or polysynaptic pathways with thalamic or cortical relays. PMID:24095981

Neagu, Bogdan; Tsang, Eric; Mazzella, Filomena; Hamani, Clement; Moro, Elena; Hodaie, Mojgan; Lozano, Andres M; Chen, Robert

2013-12-01

114

Extracellular stimulation window explained by a geometry-based model of the neuron-electrode contact.  

PubMed

Extracellular stimulation of single cultured neurons which are completely sealing a microelectrode is usually performed using anodic or biphasic currents of at least 200 nA. However, recently obtained experimental data demonstrate the possibility to stimulate a neuron using cathodic current pulses with less amplitude. Also, a stimulation window is observed. These findings can be explained by a finite-element model which permits geometry-based electrical representation of the neuron-electrode interface and can be used to explore the required conditions for extracellular stimulation in detail. Modulation of the voltage sensitive channels in the sealing part of the membrane appears to be the key to successful cathodic stimulation. Furthermore, the upper limit of the stimulation window can be explained as a normal consequence of the neuronal membrane electrophysiology. PMID:12549741

Buitenweg, Jan Reinoud; Rutten, Wim L C; Marani, Enrico

2002-12-01

115

Does suppression of oscillatory synchronisation mediate some of the therapeutic effects of DBS in patients with Parkinson's disease?  

PubMed Central

There is growing evidence for exaggerated oscillatory neuronal synchronisation in patients with Parkinson's disease (PD). In particular, oscillations at around 20 Hz, in the so-called beta frequency band, relate to the cardinal symptoms of bradykinesia and rigidity. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) can significantly improve these motor impairments. Recent evidence has demonstrated reduction of beta oscillations concurrent with alleviation of PD motor symptoms, raising the possibility that suppression of aberrant activity may mediate the effects of DBS. Here we review the evidence supporting suppression of pathological oscillations during stimulation and discuss how this might underlie the efficacy of DBS. We also consider how beta activity may provide a feedback signal suitable for next generation closed-loop and intelligent stimulators.

Eusebio, Alexandre; Cagnan, Hayriye; Brown, Peter

2012-01-01

116

Construction of a Simple Suction Electrode for Extracellular Recording and Stimulation  

NSDL National Science Digital Library

Principles of signal transmission in nervous systems are commonly demonstrated in the undergraduate neuroscience laboratory through extracellular recording of nerve and muscle action potentials. Here we describe the construction of a simple suction electrode that we use routinely in our laboratory classes for nerve recording and stimulation.

Bruce R. Johnson, Stephen A. Hauptman, and Robert H. Bonow (Cornell University;)

2008-06-12

117

Comparison of spinal cord stimulation profiles from intra- and extradural electrode arrangements by finite element modelling.  

PubMed

Spinal cord stimulation currently relies on extradural electrode arrays that are separated from the spinal cord surface by a highly conducting layer of cerebrospinal fluid. It has recently been suggested that intradural placement of the electrodes in direct contact with the pial surface could greatly enhance the specificity and efficiency of stimulation. The present computational study aims at quantifying and comparing the electrical current distributions as well as the spatial recruitment profiles resulting from extra- and intra-dural electrode arrangements. The electrical potential distribution is calculated using a 3D finite element model of the human thoracic spinal canal. The likely recruitment areas are then obtained using the potential as input to an equivalent circuit model of the pre-threshold axonal response. The results show that the current threshold to recruitment of axons in the dorsal column is more than an order of magnitude smaller for intradural than extradural stimulation. Intradural placement of the electrodes also leads to much higher contrast between the stimulation thresholds for the dorsal root entry zone and the dorsal column, allowing better focusing of the stimulus. PMID:24771203

Huang, Qiujun; Oya, Hiroyuki; Flouty, Oliver E; Reddy, Chandan G; Howard, Matthew A; Gillies, George T; Utz, Marcel

2014-06-01

118

[Deep brain stimulation for hyperkinetic movement disorders].  

PubMed

The term hyperkinetic movement disorder encompasses dystonia, tremor, chorea, myoclon and tics. These symptoms are all caused by dysfunctional neural networks including the basal ganglia loop and can be accompanied by other neurological or psychiatric symptoms. Deep brain stimulation (DBS) is an important extension of therapeutic options for this group of patients in whom drug therapy is limited. Permanent electrodes are implanted in various subcortical brain areas in order to achieve an improvement in motor symptoms by high frequency stimulation. Already established indications include primary generalized or segmental dystonia and essential tremor but an increasingly better understanding of systemic pathophysiology has allowed DBS to be explored as a treatment for other disorders of the hyperkinetic spectrum. This article provides an overview of common hyperkinetic movement disorders from the viewpoint of recent advances in neurostimulation therapy. PMID:24452308

Reich, M M; Volkmann, J

2014-02-01

119

Surface Electrical Stimulation for Treating Swallowing Disorders after Stroke: A Review of the Stimulation Intensity Levels and the Electrode Placements  

PubMed Central

Neuromuscular electrical stimulation (NMES) for treating dysphagia is a relatively new therapeutic method. There is a paucity of evidence about the use of NMES in patients with dysphagia caused by stroke. The present review aimed to introduce and discuss studies that have evaluated the efficacy of this method amongst dysphagic patients following stroke with emphasis on the intensity of stimulation (sensory or motor level) and the method of electrode placement on the neck. The majority of the reviewed studies describe some positive effects of the NMES on the neck musculature in the swallowing performance of poststroke dysphagic patients, especially when the intensity of the stimulus is adjusted at the sensory level or when the motor electrical stimulation is applied on the infrahyoid muscles during swallowing.

Poorjavad, Marziyeh; Talebian Moghadam, Saeed; Daemi, Mostafa

2014-01-01

120

Postoperative delirium in Parkinson's disease patients following deep brain stimulation surgery.  

PubMed

Deep brain stimulation (DBS) surgery is an effective treatment for patients with advanced Parkinson's disease. Delirium in hospitalized Parkinson's disease patients is common and often leads to prolonged hospital stays. This study reports on the incidence and etiology of postoperative delirium following DBS surgery. Patients (n=59) with advanced Parkinson's disease underwent bilateral (n=56) or unilateral (n=3) DBS electrode implant surgery, followed 1week later with surgical placement of DBS generators. The development of delirium during either hospital stay was evaluated retrospectively from the hospital chart. Potential causes of delirium were evaluated, including history of delirium, opiate equivalents, medication administration delays and missed doses during hospitalization, and Parkinson's disease duration. Delirium following implantation of DBS electrodes was common (22% of patients). It was less commonly associated with generator placement (10%). A history of delirium, age, and disease duration were positive predictors of delirium. Opiate equivalent doses were negatively correlated with delirium. Missed Parkinson's medication doses (53% of patients) and delayed administration (81% of patients) were common, and had a slight relation with delirium. Delirium was not related to complexity of medication regimen or use of dementia medications. Despite the presence of delirium most patients still only required a single night in the hospital post-surgery (67%). Prolonged hospital stay was due not only to delirium but also severe off states and other medical issues. Recognition and expectant management of delirium is best accomplished in a multidisciplinary setting, including the patient's family and nursing, pharmacy and neurological surgery staff. PMID:24518269

Carlson, Jonathan D; Neumiller, Joshua J; Swain, Lindy D W; Mark, Jamie; McLeod, Pam; Hirschauer, Jeff

2014-07-01

121

Intraoperative MR-guided DBS implantation for treating PD and ET  

NASA Astrophysics Data System (ADS)

Deep brain stimulator (DBS) implantation is a promising treatment alternative for suppressing the motor tremor symptoms in Parkinson disease (PD) patient. The main objective is to develop a minimally invasive approach using high spatial resolution and soft-tissue contrast MR imaging techniques to guide the surgical placement of DBS. In the MR-guided procedure, the high spatial resolution MR images were obtained intra-operatively and used to target stereotactically a specific deep brain location. The neurosurgery for craniotomy was performed in the front of the magnet outside of the 10 Gauss line. Aided with positional registration assembly for the stereotactic head frame, the target location (VIM or GPi or STN) in deep brain areas was identified and measured from the MR images in reference to the markers in the calibration assembly of the head frame before the burrhole prep. In 20 patients, MR- guided DBS implantations have been performed according to the new methodology. MR-guided DBS implantation at high magnetic field strength has been shown to be feasible and desirable. In addition to the improved outcome, this offers a new surgical approach in which intra-operative visualization is possible during intervention, and any complications such as bleeding can be assessed in situ immediately prior to dural closure.

Liu, Haiying; Maxwell, Robert E.; Truwit, Charles L.

2001-05-01

122

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

PubMed Central

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 surgically manipulated. Hearing tests were conducted before implantation (BI) and then 4 weeks post implantation both without electrical stimulation (NS) and with electrical stimulation (S). During the latter condition, prosthetic electrical stimuli encoding 3 dimensions of head angular velocity were delivered to the 3 ampullary branches of the left vestibular nerve via each of 3 electrode pairs of a multichannel vestibular prosthesis. Electrical stimuli comprised charge-balanced biphasic pulses at a baseline rate of 94 pulses/sec, with pulse frequency modulated from 48–222 pulses/s by head angular velocity. ABR hearing thresholds to clicks and tone pips at 1, 2, and 4 kHz increased by 5–10 dB from BI to NS and increased another ~5 dB from NS to S in implanted ears. No significant change was seen in right ears. DPOAE amplitudes decreased by 2–14 dB from BI to NS in implanted ears. There was a slight but insignificant decrease of DPOAE amplitude and a corresponding increase of DPOAE/Noise floor ratio between NS and S in implanted ears. Vestibular prosthesis electrode implantation and activation have small but measurable effects on hearing in rhesus monkeys. Coupled with the clinical observation that patients with cochlear implants only rarely exhibit signs of vestibular injury or spurious vestibular nerve stimulation, these results suggest that although implantation and activation of multichannel vestibular prosthesis electrodes in human will carry a risk of hearing loss, that loss is not likely to be severe.

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

2011-01-01

123

Effects of vestibular prosthesis electrode implantation and stimulation on hearing in rhesus monkeys.  

PubMed

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 surgically manipulated. Hearing tests were conducted before implantation (BI) and then 4 weeks post-implantation both without electrical stimulation (NS) and with electrical stimulation (S). During the latter condition, prosthetic electrical stimuli encoding 3 dimensions of head angular velocity were delivered to the 3 ampullary branches of the left vestibular nerve via each of 3 electrode pairs of a multichannel vestibular prosthesis. Electrical stimuli comprised charge-balanced biphasic pulses at a baseline rate of 94 pulses/s, with pulse frequency modulated from 48 to 222 pulses/s by head angular velocity. ABR hearing thresholds to clicks and tone pips at 1, 2, and 4 kHz increased by 5-10 dB from BI to NS and increased another ?5 dB from NS to S in implanted ears. No significant change was seen in right ears. DPOAE amplitudes decreased by 2-14 dB from BI to NS in implanted ears. There was a slight but insignificant decrease of DPOAE amplitude and a corresponding increase of DPOAE/Noise floor ratio between NS and S in implanted ears. Vestibular prosthesis electrode implantation and activation have small but measurable effects on hearing in rhesus monkeys. Coupled with the clinical observation that patients with cochlear implants only rarely exhibit signs of vestibular injury or spurious vestibular nerve stimulation, these results suggest that although implantation and activation of multichannel vestibular prosthesis electrodes in human will carry a risk of hearing loss, that loss is not likely to be severe. PMID:21195755

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

2011-07-01

124

Nanowire electrodes for high-density stimulation and measurement of neural circuits.  

PubMed

Brain-machine interfaces (BMIs) that can precisely monitor and control neural activity will likely require new hardware with improved resolution and specificity. New nanofabricated electrodes with feature sizes and densities comparable to neural circuits may lead to such improvements. In this perspective, we review the recent development of vertical nanowire (NW) electrodes that could provide highly parallel single-cell recording and stimulation for future BMIs. We compare the advantages of these devices and discuss some of the technical challenges that must be overcome for this technology to become a platform for next-generation closed-loop BMIs. PMID:23486552

Robinson, Jacob T; Jorgolli, Marsela; Park, Hongkun

2013-01-01

125

Nanowire electrodes for high-density stimulation and measurement of neural circuits  

PubMed Central

Brain-machine interfaces (BMIs) that can precisely monitor and control neural activity will likely require new hardware with improved resolution and specificity. New nanofabricated electrodes with feature sizes and densities comparable to neural circuits may lead to such improvements. In this perspective, we review the recent development of vertical nanowire (NW) electrodes that could provide highly parallel single-cell recording and stimulation for future BMIs. We compare the advantages of these devices and discuss some of the technical challenges that must be overcome for this technology to become a platform for next-generation closed-loop BMIs.

Robinson, Jacob T.; Jorgolli, Marsela; Park, Hongkun

2013-01-01

126

Determination of optimal electrode positions for transcranial direct current stimulation (tDCS).  

PubMed

The present study introduces a new approach to determining optimal electrode positions in transcranial direct current stimulation (tDCS). Electric field and 3D conduction current density were analyzed using 3D finite element method (FEM) formulated for a dc conduction problem. The electrode positions for minimal current injection were optimized by changing the Cartesian coordinate system into the spherical coordinate system and applying the (2+6) evolution strategy (ES) algorithm. Preliminary simulation studies applied to a standard three-layer head model demonstrated that the proposed approach is promising in enhancing the performance of tDCS. PMID:18490807

Im, Chang-Hwan; Jung, Hui-Hun; Choi, Jung-Do; Lee, Soo Yeol; Jung, Ki-Young

2008-06-01

127

Motor Cortex Stimulation in Parkinson's Disease  

PubMed Central

Motor Cortex Stimulation (MCS) is less efficacious than Deep Brain Stimulation (DBS) in Parkinson's disease. However, it might be proposed to patients excluded from DBS or unresponsive to DBS. Ten patients with advanced PD underwent unilateral MCS contralaterally to the worst clinical side. A plate electrode was positioned over the motor cortex in the epidural space through single burr hole after identification of the area with neuronavigation and neurophysiological tests. Clinical assessment was performed by total UPDRS, UPDRS III total, UPDRS III-items 27–31, UPDRS IV, and UPDRS II before implantation in off-medication and on-medication states and after surgery at 1, 3, 6, 12, 18, 24, and 36 months in on-medication/on-stimulation and off-medication/on-stimulation states. We assessed changes of quality of life, throughout the Parkinson's disease quality of life scale (PDQoL-39), and the dose of anti-Parkinson's disease medications, throughout the Ldopa equivalent daily dose (LEDD). During off-medication state, we observed moderate and transitory reduction of total UPDRS and UPDRS total scores and significant and long-lasting improvement in UPDRS III items 27–31 score for axial symptoms. There was marked reduction of UPDRS IV score and LEDD. PDQL-39 improvement was also significant. No important complications and adverse events occurred.

De Rose, Marisa; Guzzi, Giusy; Bosco, Domenico; Romano, Mary; Lavano, Serena Marianna; Plastino, Massimiliano; Volpentesta, Giorgio; Marotta, Rosa; Lavano, Angelo

2012-01-01

128

Integration of pre-aligned liquid metal electrodes for neural stimulation within a user-friendly microfluidic platform.  

PubMed

Electrical stimulation of nervous tissue is used clinically for the treatment of multiple neurological disorders and experimentally for basic research. With the increase of optical probes to record neuronal activity, simple and user-friendly methods are desired to stimulate neurons and their subcellular compartments for biological experimentation. Here we describe the novel integration of liquid metal electrodes with microfluidic culture platforms to accomplish this goal. We integrated electrode and cell channels into a single poly(dimethylsiloxane) (PDMS) chip, eliminating entirely the need to align electrodes with microchannels. We designed the electrode channels such that the metal can be injected by hand and when the device is non-covalently bound to glass. We demonstrated the biocompatibility of the electrodes for long-term cultures (12 days) using hippocampal neurons. We demonstrated the use of these electrodes to depolarize neurons and recorded neuronal activity using the calcium indicator dye, Fluo-4. We established optimal stimulation parameters that induce neuronal spiking without inducing damage. We showed that the liquid metal electrode evoked larger calcium responses in somata than bath electrodes using the same stimulus parameters. Lastly we demonstrated the use of these liquid metal electrodes to target and depolarize axons. In summary, the integration of liquid metal electrodes with neuronal culture platforms provides a user-friendly and targeted method to stimulate neurons and their subcellular compartments, thus providing a novel tool for future biological investigations. PMID:23232866

Hallfors, Nicholas; Khan, Asif; Dickey, Michael D; Taylor, Anne Marion

2013-02-21

129

High-frequency stimulation of the subthalamic nucleus increases glutamate in the subthalamic nucleus of rats as demonstrated by in vivo enzyme-linked glutamate sensor.  

PubMed

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective therapy for Parkinson's disease; however, the mechanism whereby DBS ameliorates the symptoms of Parkinson's disease remains an area of intense research. In the present study, we investigated the hypothesis that the neurotransmitter glutamate is released within the STN during high-frequency stimulation (HFS) of the STN. Direct measurements of extracellular glutamate concentration in the STN were made using a dual enzyme-based electrochemical sensor. The studies were carried out in ketamine/xylazine anesthetized rats placed in a Kopf stereotaxic head frame. Various electrical stimulations (100-micros cathodic pulses; 100-3000 microA; 10- to 1000-Hz frequency; 5-s to 60-min stimulus durations) using bipolar stimulating electrodes were delivered to the STN. Stimulation of the STN elevated the concentration of glutamate in the STN. The concentration of glutamate rose quickly during HFS, remained elevated for the duration of stimulation, and descended slowly towards baseline upon cessation of stimulation. Elevation of the extracellular concentration of glutamate in the STN may be an important mechanism whereby DBS in the STN improves the symptoms of Parkinson's disease. Furthermore, our data argue against the hypothesis that DBS works primarily by electrotonic inhibition of the stimulated structure. PMID:17618941

Lee, Kendall H; Kristic, Katarina; van Hoff, Ryan; Hitti, Frederick L; Blaha, Charles; Harris, Brent; Roberts, David W; Leiter, J C

2007-08-01

130

High frequency deep brain stimulation attenuates subthalamic and cortical rhythms in Parkinson's disease  

PubMed Central

Parkinson's disease (PD) is marked by excessive synchronous activity in the beta (8–35 Hz) band throughout the cortico-basal ganglia network. The optimal location of high frequency deep brain stimulation (HF DBS) within the subthalamic nucleus (STN) region and the location of maximal beta hypersynchrony are currently matters of debate. Additionally, the effect of STN HF DBS on neural synchrony in functionally connected regions of motor cortex is unknown and is of great interest. Scalp EEG studies demonstrated that stimulation of the STN can activate motor cortex antidromically, but the spatial specificity of this effect has not been examined. The present study examined the effect of STN HF DBS on neural synchrony within the cortico-basal ganglia network in patients with PD. We measured local field potentials dorsal to and within the STN of PD patients, and additionally in the motor cortex in a subset of these patients. We used diffusion tensor imaging (DTI) to guide the placement of subdural cortical surface electrodes over the DTI-identified origin of the hyperdirect pathway (HDP) between motor cortex and the STN. The results demonstrated that local beta power was attenuated during HF DBS both dorsal to and within the STN. The degree of attenuation was monotonic with increased DBS voltages in both locations, but this voltage-dependent effect was greater in the central STN than dorsal to the STN (p < 0.05). Cortical signals over the estimated origin of the HDP also demonstrated attenuation of beta hypersynchrony during DBS dorsal to or within STN, whereas signals from non-specific regions of motor cortex were not attenuated. The spatially-specific suppression of beta synchrony in the motor cortex support the hypothesis that DBS may treat Parkinsonism by reducing excessive synchrony in the functionally connected sensorimotor network.

Whitmer, Diane; de Solages, Camille; Hill, Bruce; Yu, Hong; Henderson, Jaimie M.; Bronte-Stewart, Helen

2012-01-01

131

High frequency deep brain stimulation attenuates subthalamic and cortical rhythms in Parkinson's disease.  

PubMed

Parkinson's disease (PD) is marked by excessive synchronous activity in the beta (8-35 Hz) band throughout the cortico-basal ganglia network. The optimal location of high frequency deep brain stimulation (HF DBS) within the subthalamic nucleus (STN) region and the location of maximal beta hypersynchrony are currently matters of debate. Additionally, the effect of STN HF DBS on neural synchrony in functionally connected regions of motor cortex is unknown and is of great interest. Scalp EEG studies demonstrated that stimulation of the STN can activate motor cortex antidromically, but the spatial specificity of this effect has not been examined. The present study examined the effect of STN HF DBS on neural synchrony within the cortico-basal ganglia network in patients with PD. We measured local field potentials dorsal to and within the STN of PD patients, and additionally in the motor cortex in a subset of these patients. We used diffusion tensor imaging (DTI) to guide the placement of subdural cortical surface electrodes over the DTI-identified origin of the hyperdirect pathway (HDP) between motor cortex and the STN. The results demonstrated that local beta power was attenuated during HF DBS both dorsal to and within the STN. The degree of attenuation was monotonic with increased DBS voltages in both locations, but this voltage-dependent effect was greater in the central STN than dorsal to the STN (p < 0.05). Cortical signals over the estimated origin of the HDP also demonstrated attenuation of beta hypersynchrony during DBS dorsal to or within STN, whereas signals from non-specific regions of motor cortex were not attenuated. The spatially-specific suppression of beta synchrony in the motor cortex support the hypothesis that DBS may treat Parkinsonism by reducing excessive synchrony in the functionally connected sensorimotor network. PMID:22675296

Whitmer, Diane; de Solages, Camille; Hill, Bruce; Yu, Hong; Henderson, Jaimie M; Bronte-Stewart, Helen

2012-01-01

132

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

PubMed

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

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

2014-05-01

133

Effectiveness of diaphragmatic stimulation with single-channel electrodes in rabbits*  

PubMed Central

Every year, a large number of individuals become dependent on mechanical ventilation because of a loss of diaphragm function. The most common causes are cervical spinal trauma and neuromuscular diseases. We have developed an experimental model to evaluate the performance of electrical stimulation of the diaphragm in rabbits using single-channel electrodes implanted directly into the muscle. Various current intensities (10, 16, 20, and 26 mA) produced tidal volumes above the baseline value, showing that this model is effective for the study of diaphragm performance at different levels of electrical stimulation

Ghedini, Rodrigo Guellner; Espinel, Julio de Oliveira; Felix, Elaine Aparecida; Paludo, Artur de Oliveira; Mariano, Rodrigo; Holand, Arthur Rodrigo Ronconi; Andrade, Cristiano Feijo

2013-01-01

134

Combined use of transcranial magnetic stimulation and metal electrode implants: a theoretical assessment of safety considerations.  

PubMed

This paper provides a theoretical assessment of the safety considerations encountered in the simultaneous use of transcranial magnetic stimulation (TMS) and neurological interventions involving implanted metallic electrodes, such as electrocorticography. Metal implants are subject to magnetic forces due to fast alternating magnetic fields produced by the TMS coil. The question of whether the mechanical movement of the implants leads to irreversible damage of brain tissue is addressed by an electromagnetic simulation which quantifies the magnitude of imposed magnetic forces. The assessment is followed by a careful mechanical analysis determining the maximum tolerable force which does not cause irreversible tissue damage. Results of this investigation provide useful information on the range of TMS stimulator output powers which can be safely used in patients having metallic implants. It is shown that conventional TMS applications can be considered safe when applied on patients with typical electrode implants as the induced stress in the brain tissue remains well below the limit of tissue damage. PMID:23135209

Golestanirad, Laleh; Rouhani, Hossein; Elahi, Behzad; Shahim, Kamal; Chen, Robert; Mosig, Juan R; Pollo, Claudio; Graham, Simon J

2012-12-01

135

Transcranial current stimulation focality using disc and ring electrode configurations: FEM analysis  

Microsoft Academic Search

We calculated the electric fields induced in the brain during transcranial current stimulation (TCS) using a finite-element concentric spheres human head model. A range of disc electrode configurations were simulated: (1) distant-bipolar; (2) adjacent-bipolar; (3) tripolar; and three ring designs, (4) belt, (5) concentric ring, and (6) double concentric ring. We compared the focality of each configuration targeting cortical structures

Abhishek Datta; Maged Elwassif; Fortunato Battaglia; Marom Bikson

2008-01-01

136

A computational model for the stimulation of rat sciatic nerve using a transverse intrafascicular multichannel electrode.  

PubMed

Neuroprostheses based on electrical stimulation could potentially help disabled persons. They are based on neural interface that aim at creating an intimate contact with neural cells. The efficacy of neuroprostheses can be improved by increasing the selectivity of the neural interfaces used to stimulate specific subsets of cells. Selectivity is strongly influenced by interface design. Computer models can be useful for exploring the high dimensional space of design parameters with the aim to provide guidelines for the development of more efficient electrodes, with minimal animal use and optimization of manufacturing processes. The purpose of this study was to implement a realistic model of the performance of a transverse intrafascicular multichannel electrode (TIME) implanted into the rat sciatic nerve. A realistic finite element method (FEM) model was developed taking into account the anatomical and physiological features of the rat sciatic nerve. Electric potentials were calculated and interpolated voltages were applied to the model of a rat sciatic nerve axon, based on experimental biophysical data. Results indicate that high intra-fascicular and inter-fascicular selectivity values with low current levels can be achieved with TIMEs. The selectivity of TIMEs was also compared to an extraneural electrode, showing that higher selectivity with less current can be obtained. Using this model, the robustness of electrode performances for translational and rotational displacements were evaluated. PMID:21693427

Raspopovic, Stanisa; Capogrosso, Marco; Micera, Silvestro

2011-08-01

137

How to Culture, Record and Stimulate Neuronal Networks on Micro-electrode Arrays (MEAs)  

PubMed Central

For the last century, many neuroscientists around the world have dedicated their lives to understanding how neuronal networks work and why they stop working in various diseases. Studies have included neuropathological observation, fluorescent microscopy with genetic labeling, and intracellular recording in both dissociated neurons and slice preparations. This protocol discusses another technology, which involves growing dissociated neuronal cultures on micro-electrode arrays (also called multi-electrode arrays, MEAs). There are multiple advantages to using this system over other technologies. Dissociated neuronal cultures on MEAs provide a simplified model in which network activity can be manipulated with electrical stimulation sequences through the array's multiple electrodes. Because the network is small, the impact of stimulation is limited to observable areas, which is not the case in intact preparations. The cells grow in a monolayer making changes in morphology easy to monitor with various imaging techniques. Finally, cultures on MEAs can survive for over a year in vitro which removes any clear time limitations inherent with other culturing techniques.1 Our lab and others around the globe are utilizing this technology to ask important questions about neuronal networks. The purpose of this protocol is to provide the necessary information for setting up, caring for, recording from and electrically stimulating cultures on MEAs. In vitro networks provide a means for asking physiologically relevant questions at the network and cellular levels leading to a better understanding of brain function and dysfunction.

Hales, Chadwick M.; Rolston, John D.; Potter, Steve M.

2010-01-01

138

Transcranial current stimulation focality using disc and ring electrode configurations: FEM analysis  

NASA Astrophysics Data System (ADS)

We calculated the electric fields induced in the brain during transcranial current stimulation (TCS) using a finite-element concentric spheres human head model. A range of disc electrode configurations were simulated: (1) distant-bipolar; (2) adjacent-bipolar; (3) tripolar; and three ring designs, (4) belt, (5) concentric ring, and (6) double concentric ring. We compared the focality of each configuration targeting cortical structures oriented normal to the surface ('surface-radial' and 'cross-section radial'), cortical structures oriented along the brain surface ('surface-tangential' and 'cross-section tangential') and non-oriented cortical surface structures ('surface-magnitude' and 'cross-section magnitude'). For surface-radial fields, we further considered the 'polarity' of modulation (e.g. superficial cortical neuron soma hyper/depolarizing). The distant-bipolar configuration, which is comparable with commonly used TCS protocols, resulted in diffuse (un-focal) modulation with bi-directional radial modulation under each electrode and tangential modulation between electrodes. Increasing the proximity of the two electrodes (adjacent-bipolar electrode configuration) increased focality, at the cost of more surface current. At similar electrode distances, the tripolar-electrodes configuration produced comparable peak focality, but reduced radial bi-directionality. The concentric-ring configuration resulted in the highest spatial focality and uni-directional radial modulation, at the expense of increased total surface current. Changing ring dimensions, or use of two concentric rings, allow titration of this balance. The concentric-ring design may thus provide an optimized configuration for targeted modulation of superficial cortical neurons.

Datta, Abhishek; Elwassif, Maged; Battaglia, Fortunato; Bikson, Marom

2008-06-01

139

Effects of Deep Brain Stimulation and Medication on Strength, Bradykinesia, and Electromyographic Patterns of the Ankle Joint in Parkinson's Disease  

PubMed Central

We investigated the control of movement in 12 patients with Parkinson’s disease (PD) after they received surgically implanted high-frequency stimulating electrodes in the subthalamic nucleus (STN). The experiment studied ankle strength, movement velocity, and the associated electromyographic patterns in PD patients, six of whom had tremor at the ankle. The patients were studied off treatment, ON STN deep brain stimulation (DBS), on medication, and on medication plus STN DBS. Twelve matched control subjects were also examined. Medication alone and STN DBS alone increased patients’ ankle strength, ankle velocity, agonist muscle burst amplitude, and agonist burst duration, while reducing the number of agonist bursts during movement. These findings were similar for PD patients with and without tremor. The combination of medication plus STN DBS normalized maximal strength at the ankle joint, but ankle movement velocity and electromyographic patterns were not normalized. The findings are the first to demonstrate that STN DBS and medication increase strength and movement velocity at the ankle joint.

Vaillancourt, David E.; Prodoehl, Janey; Sturman, Molly M.; Bakay, Roy A.E.; Metman, Leo Verhagen; Corcos, Daniel M.

2008-01-01

140

Long-term deep brain stimulation for essential tremor: 12-year clinicopathologic follow-up.  

PubMed

We describe the clinical course and postmortem pathological findings in a patient with essential tremor (ET) treated with deep brain stimulation (DBS) for 12 years. This 75 year old woman had a 13-year history of progressive ET prior to implantation of bilateral quadripolar DBS electrodes in the region of her ventral intermediate thalamic nuclei in 1996, producing immediate relief of arm tremor. Histopathological examination of the brain, performed 12 years after the initial implantation, demonstrated electrode catheter tracts rimmed by 20-25 micron fibrous sheaths, with multinucleated giant cells and reactive gliosis. Lymphocytic infiltration was seen by L26 immunoreactivity with CD3 (T cells) staining predominating over CD20 (B cells). Cerebellar axonal spheroids and Purkinje cell loss were found. The minimal foreign body reaction and gliosis around the electrodes 12 years after implantation supports the long-term safety of DBS. The case represents the longest reported follow-up with autopsy examination after DBS and confirmed histological changes associated with ET. PMID:20063387

DiLorenzo, Daniel J; Jankovic, Joseph; Simpson, Richard K; Takei, Hidehiro; Powell, Suzanne Z

2010-01-30

141

Evaluation of Platinum-Black Stimulus Electrode Array for Electrical Stimulation of Retinal Cells in Retinal Prosthesis System  

Microsoft Academic Search

A retinal prosthesis system with a three-dimensionally (3D) stacked LSI chip has been proposed. We fabricated a new implantable stimulus electrode array deposited with Platinum-black (Pt-b) on a polyimide-based flexible printed circuit (FPC) for the electrical stimulation of the retinal cells. Impedance measurement of the Pt-b electrode-electrolyte interface in a saline solution was performed and the Pt-b electrode realized a

Taiichiro Watanabe; Risato Kobayashi; Ken Komiya; Takafumi Fukushima; Hiroshi Tomita; Eriko Sugano; Hiroyuki Kurino; Tetsu Tanaka; Makoto Tamai; Mitsumasa Koyanagi

2007-01-01

142

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

PubMed Central

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 ?-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.

2010-01-01

143

Continuous stimulation of the pedunculopontine tegmental nucleus at 40Hz affects preparative and executive control in a delayed sensorimotor task and reduces rotational movements induced by apomorphine in the 6-OHDA parkinsonian rat.  

PubMed

The pedunculopontine tegmental nucleus (PPTg) relays basal ganglia signals to the thalamus, lower brainstem and spinal cord. Using the 6-hydroxydopamine (6-OHDA) rat model of parkinsonism, we investigated whether deep brain stimulation (DBS) of the PPTg (40Hz, 60?s, 200-400?A) may influence the preparative and executive phases in a conditioned behavioural task, and the motor asymmetries induced by apomorphine. In the conditioned task, rats had to press two levers according to a fixed delay paradigm. The 6-OHDA lesion was placed in the right medial forebrain bundle, i.e. contralaterally to the preferred forepaw used by rats to press levers in the adopted task. The stimulating electrode was implanted in the right PPTg, i.e. contralateral to left side, which was expected to be most affected. The lesion significantly reduced correct responses from 63.4% to 16.6%. PPTg-DBS effects were episodic; however, when rats successfully performed in the task (18.9%), reaction time (468.8±36.5ms) was significantly increased (589.9±45.9ms), but not improved by PPTg-DBS (646.7±33.8ms). Movement time was significantly increased following the lesion (649.2±42.6ms vs. 810.9±53.0ms), but significantly reduced by PPTg-DBS (820.4±39.4ms) compared to sham PPTg-DBS (979.8±47.6ms). In a second group of lesioned rats, rotations induced by apomorphine were significantly reduced by PPTg-DBS compared to sham PPTg-DBS (12.2±0.6 vs. 9.5±0.4 mean turns/min). Thus, it appears that specific aspects of motor deficits in 6-OHDA-lesioned rats may be modulated by PPTg-DBS. PMID:24959863

Capozzo, Annamaria; Vitale, Flora; Mattei, Claudia; Mazzone, Paolo; Scarnati, Eugenio

2014-09-01

144

Stimulation selectivity of the “thin-film longitudinal intrafascicular electrode” (tfLIFE) and the “transverse intrafascicular multi-channel electrode” (TIME) in the large nerve animal model.  

PubMed

Neural prostheses are limited by the availability of peripheral neural electrodes to record the user's intention or provide sensory feedback through functional electrical stimulation. Our objective was to compare the ability of the novel “transverse intrafascicular multi-channel electrode” (TIME) and an earlier generation “thin-film longitudinal intrafascicular electrode” (tfLIFE) to selectively stimulate nerve fascicles and activate forelimb muscles in pigs. TIME was designed to access a larger subpopulation of fascicles than tfLIFE and should therefore be able to selectively activate a larger number of muscles. Electrodes were implanted in the median nerve, and sequential electric stimulation was applied to individual contacts. The compound muscle action potentials of seven muscles were recorded to quantify muscle recruitment. As expected, TIME was able to recruit more muscles with higher selectivity than tfLIFE (significant difference when comparing the performance of an entire electrode); a similar activation current was used (no significant difference). Histological analysis revealed that electrodes were located between fascicles, which influenced the selectivity and activation current level. In conclusion, TIME is a viable neural interface for selective activation of multiple fascicles in human-sized nerves that may assist to pave the way for future neuroprosthesis applications. PMID:23799699

Kundu, Aritra; Harreby, Kristian Rauhe; Yoshida, Ken; Boretius, Tim; Stieglitz, Thomas; Jensen, Winnie

2014-03-01

145

Neuropsychological and quality of life outcomes 12 months after unilateral thalamic stimulation for essential tremor  

PubMed Central

Objectives: To evaluate the one year cognitive, mood state, and quality of life (QoL) outcomes of unilateral thalamic deep brain stimulation (DBS) for essential tremor (ET). Methods: 40 patients diagnosed with ET completed comprehensive neuropsychological assessments about one month before and three and 12 months after DBS electrode implantation. Data were subjected to multivariate analyses, and significant results were further analysed using univariate techniques. Results: Analyses revealed statistically significant improvements on a cognitive screening measure and in aspects of fine visuomotor and visuoperceptual functions, verbal memory, mood state, and QoL. No group-wise declines in cognition were observed, but more patients showed declines than improvements on language and visual memory tests. Semantic verbal fluency declined significantly in four (10%) of the patients. In these four patients, diminished lexical verbal fluency was present at baseline. Conclusion: Cognitive, mood, and QoL outcomes after one year of DBS for ET are favourable; there were no overall deleterious effects on cognition, and DBS was accompanied by a significant reduction in anxiety and improvements in quality of life. However, preoperative verbal fluency diminution may predispose to further fluency declines after DBS.

Fields, J; Troster, A; Woods, S; Higginson, C; Wilkinson, S; Lyons, K; Koller, W; Pahwa, R

2003-01-01

146

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

NASA Astrophysics Data System (ADS)

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-Ray Spectroscopy (EDS), and Electron Spectroscopy for Chemical Analysis (ESCA). Representative tissue/electrode interfaces were created through subcutaneous implantation and harvest from Balb/C mice after 7, 28 and 56 days. The recovered, formalin preserved conductive implant/tissue specimens were examined by Electrical Impedance Spectroscopy (EIS) over the range from 0.1 Hz to 100,000 Hz, in Bode plot and Nyquist plot formats. After EIS the implants were extracted from the tissue for surface examination by SEM and the separated tissue capsules were evaluated by histological examination in hematoxylin and eosin (H&E)-stained light microscopic thin sections. The differential findings were that the RFGDT PyC and Ta implants had significantly increased interface resistance and capacitance over their sterilized-only controls, correlating with more flattened cellular layers retained on the RFGDT specimens. The cpTi specimens, earlier identified as promoting hard tissue-to-surface integration in dental implants, showed only marginal improvements in soft tissue attachment following RFGDT. These experimental findings were confirmed through equivalent circuit modeling by the conversion from a standard Randles model with constant phase elements, which described the pre-implant materials, to a modified Randles model with additional resistance and capacitance to describe the implants with well-integrated surface coatings. Future work with RFGDT-modified electrode materials must include actual signal acquisition/stimulation trials in implant host tissues, to assess possible improvements in electrical energy-transfer efficiency and battery lifetime extensions.

O'Connor, Laurie M.

147

Bio-heat transfer model of transcranial DC stimulation: comparison of conventional pad versus ring electrode.  

PubMed

Transcranial Direct Current Stimulation (tDCS) is a non-invasive procedure where a weak electrical current is applied across the scalp to modulate brain function. The proliferation of this therapy has been accompanied by isolated reports regarding concern about their safety namely skin irritation. The potential cause of skin irritation has sometimes been attributed to increased scalp temperature during stimulation. We have developed novel technology for tDCS that improves spatial focality at the cost of increased stimulation electrode current density; high density tDCS (HD-tDCS). The goal of this paper was to provide information on the thermal effects of tDCS using a MRI-derived finite element human head model. The tissue temperature increases of tDCS using conventional rectangular-pad (7 x 5 cm(2)) and HD-tDCS using the ring (4 x 1) electrode configurations were compared using a bio-heat model. Our results indicate that clinical tDCS do not increase tissue temperature and 4 x 1 ring configurations leads to a negligible increase in scalp temperature. PMID:19964238

Datta, Abhishek; Elwassif, Maged; Bikson, Marom

2009-01-01

148

Percutaneous electrode placement for spinal cord stimulation in a patient with spinal fusion: a technical report.  

PubMed

A spinal cord stimulation (SCS) trial was attempted to alleviate left knee pain in a patient with spinal fusion from T12 to L4. Good paresthesia coverage for the knee pain was attained with SCS. However, while removing the needle used for electrode placement, the needle became fixed in the bony supplementary tissue. Moreover, while attempting to remove the needle using Kelly forceps, the hub of the needle became blocked. Without the hub, we had no choice but to use a pneumatic drill for removing the needle. Accordingly, the supplementary bone tissue was drilled under real-time imaging, using a pneumatic drill with a 3.2-mm drill bit, and another epidural needle was inserted through the hole. We consider that, in patients with spinal fusion, making a borehole with a pneumatic drill for introducing the epidural needle for percutaneous SCS electrode placement may be advisable in order to avoid the above-mentioned difficulties. PMID:22215091

Park, Sung-Chun; Kim, Kyung-Hoon

2012-04-01

149

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

NASA Astrophysics Data System (ADS)

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.

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

2011-06-01

150

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

PubMed

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-?m 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

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

2012-06-01

151

Measurements of RF Heating during 3.0T MRI of a Pig Implanted with Deep Brain Stimulator  

PubMed Central

Purpose To present preliminary, in vivo temperature measurements during MRI of a pig implanted with a deep brain stimulation (DBS) system. Materials and Methods DBS system (Medtronic Inc., Minneapolis, MN) was implanted in the brain of an anesthetized pig. 3.0T MRI was performed with a T/R head coil using the low-SAR GRE EPI and IR-prepped GRE sequences (SAR: 0.42 W/kg and 0.39 W/kg, respectively), and the high-SAR 4-echo RF spin echo (SAR: 2.9 W/kg). Fluoroptic thermometry was used to directly measure RF-related heating at the DBS electrodes, and at the implantable pulse generator (IPG). For reference the measurements were repeated in the same pig at 1.5T and, at both field strengths, in a phantom. Results At 3.0T, the maximal temperature elevations at DBS electrodes were 0.46 °C and 2.3 °C, for the low- and high-SAR sequences, respectively. No heating was observed on the implanted IPG during any of the measurements. Measurements of in-vivo heating differed from those obtained in the phantom. Conclusion The 3.0T MRI using GRE EPI and IR-prepped GRE sequences resulted in local temperature elevations at DBS electrodes of no more than 0.46°C. Although no extrapolation should be made to human exams and much further study will be needed, these preliminary data are encouraging for the future use 3.0T MRI in patients with DBS.

Gorny, Krzysztof R; Presti, Michael F; Goerss, Stephan J; Hwang, Sun C; Jang, Dong-Pyo; Kim, Inyong; Shu, Yunhong; Favazza, Christopher P; Lee, Kendall H; Bernstein, Matt A

2012-01-01

152

Delayed cerebritis after bilateral stereotactic implantation of globus pallidus interna electrodes for treatment of dystonia.  

PubMed

Deep brain stimulation (DBS) is being used to treat an increasing number of movement and psychiatric disorders. However, the risk of infection remains as a problem that can hinder the usefulness of this technology. We report a case of a patient with dystonia who underwent bilateral globus pallidus interna electrode and impulse generator (IPG) placement, developed an infection of his IPG, and later cerebritis. The patient was initially treated with antibiotics and partial hardware removal. Follow-up cranial imaging showed an area concerning for cerebritis around one of the intracranial electrodes. The patient was then treated with complete hardware removal followed by a course of intravenous antibiotics. Four-month follow-up imaging showed resolution of the infection. This case demonstrates the importance of following cranial imaging in DBS patients with delayed infection, continued vigilance for infection in implanted patients and that partial hardware removal may not be successful in the setting of methicillin-sensitive Staphylococcus aureus infections. PMID:23378545

Jankowski, Pawel P; Lessig, Stephanie; Nguyen, Andrew D; Barba, David

2013-01-01

153

The relationship between transcranial current stimulation electrode montages and the effect of the skull orbital openings.  

PubMed

Due to its low electric conductivity, the skull has a major impact on the electric field distribution in the brain in transcranial current stimulation (tCS). However, the skull has several openings that are filled with higher conductivity soft tissues, and through which a significant fraction of the injected current may pass. We show that current entering the brain via the orbital openings increases the electric field intensity in the cortical regions near the orbit. Furthermore, this depends on the how far electrodes are placed from the orbital openings. PMID:23366021

Mekonnen, A; Salvador, R; Ruffini, G; Miranda, P C

2012-01-01

154

Electrodes for high-definition transcutaneous DC stimulation for applications in drug-delivery and electrotherapy, including tDCS  

PubMed Central

Transcutaneous electrical stimulation is applied in a range of biomedical applications including Transcranial Direct Current Stimulation (tDCS). tDCS is a non-invasive procedure where a weak direct current (<2 mA) is applied across the scalp to modulate brain function. High-Definition tDCS (HD-tDCS) is a technique used to increase the spatial focality of tDCS by passing current across the scalp using <12 mm diameter electrodes. The purpose of this study was to design and optimize “high-definition” electrode-gel parameters for electrode durability, skin safety, and subjective pain. Anode and cathode electrode potential, temperature, pH, and subjective sensation over time were assessed during application of 2 mA direct current, for up to 22 minutes on agar gel or subject forearms. A selection of 5 types of solid-conductors (Ag pellet, Ag/AgCl pellet, Rubber pellet, Ag/AgCl ring, and Ag/AgCl disc) and 7 conductive gels (Signa, Spectra, Tensive, Redux, BioGel, Lectron, and CCNY-4) were investigated. The Ag/AgCl ring in combination with CCNY-4 gel resulted in the most favorable outcomes. Under anode stimulations, electrode potential and temperature rises were generally observed in all electrode-gel combinations except for Ag/AgCl ring and disc electrodes. pH remained constant for all solid-conductors except for both Ag and Rubber pellet electrodes with Signa and CCNY-4 gels. Sensation ratings were independent of stimulation polarity. Ag/AgCl ring electrodes were found to be the most comfortable followed by Ag, Rubber, and Ag/AgCl pellet electrodes across all gels.

Minhas, Preet; Bansal, Varun; Patel, Jinal; Ho, Johnson S.; Diaz, Julian; Datta, Abhishek; Bikson, Marom

2010-01-01

155

Electrodes for high-definition transcutaneous DC stimulation for applications in drug delivery and electrotherapy, including tDCS.  

PubMed

Transcutaneous electrical stimulation is applied in a range of biomedical applications including transcranial direct current stimulation (tDCS). tDCS is a non-invasive procedure where a weak direct current (<2 mA) is applied across the scalp to modulate brain function. High-definition tDCS (HD-tDCS) is a technique used to increase the spatial focality of tDCS by passing current across the scalp using <12 mm diameter electrodes. The purpose of this study was to design and optimize "high-definition" electrode-gel parameters for electrode durability, skin safety and subjective pain. Anode and cathode electrode potential, temperature, pH and subjective sensation over time were assessed during application of 2 mA direct current, for up to 22 min on agar gel or subject forearms. A selection of five types of solid-conductors (Ag pellet, Ag/AgCl pellet, rubber pellet, Ag/AgCl ring and Ag/AgCl disc) and seven conductive gels (Signa, Spectra, Tensive, Redux, BioGel, Lectron and CCNY-4) were investigated. The Ag/AgCl ring in combination with CCNY-4 gel resulted in the most favorable outcomes. Under anode stimulations, electrode potential and temperature rises were generally observed in all electrode-gel combinations except for Ag/AgCl ring and disc electrodes. pH remained constant for all solid-conductors except for both Ag and rubber pellet electrodes with Signa and CCNY-4 gels. Sensation ratings were independent of stimulation polarity. Ag/AgCl ring electrodes were found to be the most comfortable followed by Ag, rubber and Ag/AgCl pellet electrodes across all gels. PMID:20488204

Minhas, Preet; Bansal, Varun; Patel, Jinal; Ho, Johnson S; Diaz, Julian; Datta, Abhishek; Bikson, Marom

2010-07-15

156

Hypomania Induced by Subthalamic Nucleus Stimulation in a Parkinson's Disease Patient: Does It Suggest a Dysfunction of the Limbic Circuit?  

PubMed Central

The aim of this report was to describe a case of hypomania after deep brain stimulation of the subthalamic nucleus (STN DBS) in a Parkinson’s disease (PD) patient. 59-year-old man with a 15-year history of PD underwent bilateral implantation of electrodes to the STN. Immediately after surgery, his motor function was markedly improved and his mood was elevated to hypomania. Fusion images of the preoperative MRI and postoperative CT scan showed that the electrodes were located in the medial portion of the STN. In this case, behavioral mood change was related to the deep brain stimulation. Moreover, the anatomical location and the functional alteration of the STN after the DBS surgery might be related to the regulatory system of the associative and limbic cortico-subcortical circuits.

Kim, Ji Seon; Kim, Hee Jin; Lee, Ji-Young; Kim, Jong Min; Yun, Ji Young; Jeon, Beom S.

2012-01-01

157

Deep Brain Stimulation for Parkinson's Disease  

MedlinePLUS

NINDS Deep Brain Stimulation for Parkinson's Disease Information Page Table of Contents (click to jump to sections) What is Deep Brain ... being done? Clinical Trials Organizations What is Deep Brain Stimulation for Parkinson's Disease? Deep brain stimulation (DBS) ...

158

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

PubMed

Abstract 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

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

2014-05-01

159

Consonant recognition as a function of the number of stimulation channels in the Hybrid short-electrode cochlear implant.  

PubMed

Consonant recognition was measured as a function of the number of stimulation channels for Hybrid short-electrode cochlear implant (CI) users, long-electrode CI users, and normal-hearing (NH) listeners in quiet and background noise. Short-electrode CI subjects were tested with 1-6 channels allocated to a frequency range of 1063-7938 Hz. Long-electrode CI subjects were tested with 1-6, 8, or 22 channels allocated to 188-7938 Hz, or 1-6 or 15 channels from the basal 15 electrodes allocated to 1063-7938 Hz. NH listeners were tested with simulations of each CI group/condition. Despite differences in intracochlear electrode spacing for equivalent channel conditions, all CI subject groups performed similarly at each channel condition and improved up to at least four channels in quiet and noise. All CI subject groups underperformed relative to NH subjects. These preliminary findings suggest that the limited channel benefit seen for CI users may not be due solely to increases in channel interactions as a function of electrode density. Other factors such as pre-operative patient history, location of stimulation in the base versus apex, or a limit on the number of electric channels that can be processed cognitively, may also interact with the effects of electrode contact spacing along the cochlea. PMID:23145621

Reiss, Lina A J; Turner, Christopher W; Karsten, Sue A; Erenberg, Sheryl R; Taylor, Jessica; Gantz, Bruce J

2012-11-01

160

Consonant recognition as a function of the number of stimulation channels in the Hybrid short-electrode cochlear implanta  

PubMed Central

Consonant recognition was measured as a function of the number of stimulation channels for Hybrid short-electrode cochlear implant (CI) users, long-electrode CI users, and normal-hearing (NH) listeners in quiet and background noise. Short-electrode CI subjects were tested with 1–6 channels allocated to a frequency range of 1063–7938 Hz. Long-electrode CI subjects were tested with 1–6, 8, or 22 channels allocated to 188–7938?Hz, or 1–6 or 15 channels from the basal 15 electrodes allocated to 1063–7938?Hz. NH listeners were tested with simulations of each CI group/condition. Despite differences in intracochlear electrode spacing for equivalent channel conditions, all CI subject groups performed similarly at each channel condition and improved up to at least four channels in quiet and noise. All CI subject groups underperformed relative to NH subjects. These preliminary findings suggest that the limited channel benefit seen for CI users may not be due solely to increases in channel interactions as a function of electrode density. Other factors such as pre-operative patient history, location of stimulation in the base versus apex, or a limit on the number of electric channels that can be processed cognitively, may also interact with the effects of electrode contact spacing along the cochlea.

Reiss, Lina A. J.; Turner, Christopher W.; Karsten, Sue A.; Erenberg, Sheryl R.; Taylor, Jessica; Gantz, Bruce J.

2012-01-01

161

High-resolution extracellular stimulation of dispersed hippocampal culture with high-density CMOS multielectrode array based on non-Faradaic electrodes  

NASA Astrophysics Data System (ADS)

We introduce a method to electrically stimulate individual neurons at single-cell resolution in arbitrary spatiotemporal patterns with precise control over stimulation thresholds. By exploiting a custom microelectronic chip, up to 65 000 non-Faradaic electrodes can be uniquely addressed with electrode density exceeding 6500 electrodes mm-2. We demonstrate extracellular stimulation of dispersed primary hippocampal neuronal cultures using the chip at single-cell resolution.

Lei, N.; Ramakrishnan, S.; Shi, P.; Orcutt, J. S.; Yuste, R.; Kam, L. C.; Shepard, K. L.

2011-08-01

162

Deep brain stimulation  

Microsoft Academic Search

Brain–computer interfaces (BCIs) include stimulators, infusion devices, and neuroprostheses. They all belong to functional neurosurgery. Deep brain stimulators (DBS) are widely used for therapy and are in need of innovative evolutions. Robotized exoskeletons require BCIs able to drive up to 26 degrees of freedom (DoF). We report the nanomicrotechnology development of prototypes for new 3D DBS and for motor neuroprostheses.

Alim Louis Benabid; Thomas Costecalde; Napoleon Torres; Cecile Moro; Tetiana Aksenova; Andrey Eliseyev; Guillaume Charvet; Fabien Sauter; David Ratel; Corinne Mestais; Pierre Pollak; Stephan Chabardes

2011-01-01

163

Chronic stability and selectivity of four-contact spiral nerve-cuff electrodes in stimulating the human femoral nerve  

NASA Astrophysics Data System (ADS)

This study describes the stability and selectivity of four-contact spiral nerve-cuff electrodes implanted bilaterally on distal branches of the femoral nerves of a human volunteer with spinal cord injury as part of a neuroprosthesis for standing and transfers. Stimulation charge threshold, the minimum charge required to elicit a visible muscle contraction, was consistent and low (mean threshold charge at 63 weeks post-implantation: 23.3 ± 8.5 nC) for all nerve-cuff electrode contacts over 63 weeks after implantation, indicating a stable interface with the peripheral nervous system. The ability of individual nerve-cuff electrode contacts to selectively stimulate separate components of the femoral nerve to activate individual heads of the quadriceps was assessed with fine-wire intramuscular electromyography while measuring isometric twitch knee extension moment. Six of eight electrode contacts could selectively activate one head of the quadriceps while selectively excluding others to produce maximum twitch responses of between 3.8 and 8.1 N m. The relationship between isometric twitch and tetanic knee extension moment was quantified, and selective twitch muscle responses scaled to between 15 and 35 N m in tetanic response to pulse trains with similar stimulation parameters. These results suggest that this nerve-cuff electrode can be an effective and chronically stable tool for selectively stimulating distal nerve branches in the lower extremities for neuroprosthetic applications.

Fisher, L. E.; Tyler, D. J.; Anderson, J. S.; Triolo, R. J.

2009-08-01

164

Chronic stability and selectivity of four-contact spiral nerve-cuff electrodes in stimulating the human femoral nerve  

PubMed Central

This study describes the stability and selectivity of four-contact spiral nerve-cuff electrodes implanted bilaterally on distal branches of the femoral nerves of a human volunteer with spinal cord injury as part of a neuroprosthesis for standing and transfers. Stimulation charge threshold, the minimum charge required to elicit a visible muscle contraction, was consistent and low (mean threshold charge at 63 weeks post-implantation: 23.3 ± 8.5 nC) for all nerve-cuff electrode contacts over 63 weeks after implantation, indicating a stable interface with the peripheral nervous system. The ability of individual nerve-cuff electrode contacts to selectively stimulate separate components of the femoral nerve to activate individual heads of the quadriceps was assessed with fine-wire intramuscular electromyography while measuring isometric twitch knee extension moment. Six of eight electrode contacts could selectively activate one head of the quadriceps while selectively excluding others to produce maximum twitch responses of between 3.8 and 8.1 Nm. The relationship between isometric twitch and tetanic knee extension moment was quantified, and selective twitch muscle responses scaled to between 15 and 35 Nm in tetanic response to pulse trains with similar stimulation parameters. These results suggest that this nerve-cuff electrode can be an effective and chronically stable tool for selectively stimulating distal nerve branches in the lower extremities for neuroprosthetic applications.

Fisher, L E; Tyler, D J; Anderson, J S; Triolo, R J

2010-01-01

165

Deep Brain Stimulation Alleviates Parkinsonian Bradykinesia by Regularizing Pallidal Activity  

PubMed Central

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 (130 Hz). Bradykinesia, a symptomatic slowness of movement, was quantified via an objective finger tapping protocol in the absence and presence of regular and irregular DBS. Regular DBS relieved bradykinesia more effectively than irregular DBS. A computational model of the relevant neural structures revealed that output from the globus pallidus internus was more disordered and thalamic neurons made more transmission errors in the parkinsonian condition compared with the healthy condition. Clinically therapeutic, regular DBS reduced firing pattern disorder in the computational basal ganglia and minimized model thalamic transmission errors, consistent with symptom alleviation by clinical DBS. However, nontherapeutic, irregular DBS neither reduced disorder in the computational basal ganglia nor lowered model thalamic transmission errors. Thus we show that clinically useful DBS alleviates motor symptoms by regularizing basal ganglia activity and thereby improving thalamic relay fidelity. This work demonstrates that high-frequency stimulation alone is insufficient to alleviate motor symptoms: DBS must be highly regular. Descriptive models of pathophysiology that ignore the fine temporal resolution of neuronal spiking in favor of average neural activity cannot explain the mechanisms of DBS-induced symptom alleviation.

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

2010-01-01

166

Design, simulation and experimental validation of a novel flexible neural probe for deep brain stimulation and multichannel recording.  

PubMed

An implantable micromachined neural probe with multichannel electrode arrays for both neural signal recording and electrical stimulation was designed, simulated and experimentally validated for deep brain stimulation (DBS) applications. The developed probe has a rough three-dimensional microstructure on the electrode surface to maximize the electrode-tissue contact area. The flexible, polyimide-based microelectrode arrays were each composed of a long shaft (14.9 mm in length) and 16 electrodes (5 µm thick and with a diameter of 16 µm). The ability of these arrays to record and stimulate specific areas in a rat brain was evaluated. Moreover, we have developed a finite element model (FEM) applied to an electric field to evaluate the volume of tissue activated (VTA) by DBS as a function of the stimulation parameters. The signal-to-noise ratio ranged from 4.4 to 5 over a 50 day recording period, indicating that the laboratory-designed neural probe is reliable and may be used successfully for long-term recordings. The somatosensory evoked potential (SSEP) obtained by thalamic stimulations and in vivo electrode-electrolyte interface impedance measurements was stable for 50 days and demonstrated that the neural probe is feasible for long-term stimulation. A strongly linear (positive correlation) relationship was observed among the simulated VTA, the absolute value of the SSEP during the 200 ms post-stimulus period (?SSEP) and c-Fos expression, indicating that the simulated VTA has perfect sensitivity to predict the evoked responses (c-Fos expression). This laboratory-designed neural probe and its FEM simulation represent a simple, functionally effective technique for studying DBS and neural recordings in animal models. PMID:22488106

Lai, Hsin-Yi; Liao, Lun-De; Lin, Chin-Teng; Hsu, Jui-Hsiang; He, Xin; Chen, You-Yin; Chang, Jyh-Yeong; Chen, Hui-Fen; Tsang, Siny; Shih, Yen-Yu I

2012-06-01

167

Probabilistic Modeling of Selective Stimulation of the Human Sciatic Nerve with a Flat Interface Nerve Electrode  

PubMed Central

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 selective activation of axons within any arbitrarily designated, contiguous group of fascicles. Simulations support the hypothesis and suggest that currently available implantable technology cannot selectively recruit each target plantar flexor individually but can restore plantar flexion or dorsiflexion from a site on the sciatic nerve without spillover to antagonists. Successful activation of individual ankle muscles in 90% of the population can be achieved by utilizing bipolar stimulation and/or by using a cuff with at least 20 contacts.

Schiefer, Matthew A.; Tyler, Dustin J.; Triolo, Ronald J.

2012-01-01

168

Cuff electrodes for chronic stimulation and recording of peripheral nerve activity.  

PubMed

A comparative study of 5 different designs of nerve cuff electrodes was undertaken to determine their relative merits for stimulating and recording whole-nerve activity over extended periods of chronic implantation on large and small peripheral nerves in 8 cats. Four of the designs represent novel fabrication strategies, including 2 based on flexible, thin-film substrates and 2 based on dip-coating silicone elastomer on a cylindrical mandrel. Various advantages and shortcomings of these materials and designs are discussed in the context of the biophysical factors that influence these electrophysiological interfaces, particularly the problem of recording microvolt-level neurograms in the presence of millivolt-level electromyograms from adjacent muscles in freely behaving subjects. The most effective design was one in which a thin sheath of silicone rubber was wrapped around and intra-operatively sealed to a longitudinally slit, tripolar cuff made by dip-coating silicone over stranded stainless steel leads that were prepositioned on a mandrel using polyvinyl alcohol as a temporary adhesive. When properly installed, these electrodes had stable impedances, recruitment thresholds and relatively interference-free recording properties for the duration of this study (up to 9 weeks). PMID:8869489

Loeb, G E; Peck, R A

1996-01-01

169

Recording of the Neural Activity Induced by the Electrical Subthalamic Stimulation Using Ca2+ Imaging  

NASA Astrophysics Data System (ADS)

The basal ganglia (BG) have important roles in some kind of motor control and learning. Parkinson's disease is one of the motor impairment disease. Recently, to recover a motor severity in patients of Parkinsonism, the stimulus electrode is implanted to the subthalamic nucleus, which is a part of the basal ganglia, and the deep brain stimulation (DBS) is often conducted. However, the effects of the DBS on the subthalamic neurons have not been elucidated. Thus, to analyze the effects of the electrical stimulation on the subthalamic neurons, we conducted the calcium imaging at the mouse subthalamic nucleus. When the single stimulus was applied to the subthalamic nucleus, the intracellular calcium ([Ca2+]i) transients were observed. In the case of application of the single electrical stimulation, the [Ca2+]i arose near the stimulus position. When 100 Hz 10-100 times tetanic stimulations were applied, the responded area and the amplitudes of [Ca2+]i transients were increased. The [Ca2+]i transients were disappeared almost completely on the action potential blockade, but blockade of the excitatory and the inhibitory synaptic transmission had little effects on the responded area and the amplitudes of the [Ca2+]i transients. These results suggested that the electrical stimulation to the subthalamic neurons led to activate the subthalamic neurons directly but not via synaptic transmissions. Thus, DBS may change the activity of the subthalamic neurons, hence, may alter the input-output relationship of the subthalamic neurons

Tamura, Atsushi; Yagi, Tetsuya; Osanai, Makoto

170

Deep brain stimulation macroelectrodes compared to multiple microelectrodes in rat hippocampus  

PubMed Central

Microelectrode arrays (wire diameter <50 ?m) were compared to traditional macroelectrodes for deep brain stimulation (DBS). Understanding the neuronal activation volume may help solve some of the mysteries associated with DBS, e.g., its mechanisms of action. We used c-fos immunohistochemistry to investigate neuronal activation in the rat hippocampus caused by multi-micro- and macroelectrode stimulation. At ± 1V stimulation at 25 Hz, microelectrodes (33 ?m diameter) had a radius of activation of 100 ?m, which is 50% of that seen with 150 ?m diameter macroelectrode stimulation. Macroelectrodes activated about 5.8 times more neurons than a single microelectrode, but displaced ~20 times more neural tissue. The sphere of influence of stimulating electrodes can be significantly increased by reducing their impedance. By ultrasonic electroplating (sonicoplating) the microelectrodes with platinum to increase their surface area and reduce their impedance by an order of magnitude, the radius of activation increased by 50 ?m and more than twice the number of neurons were activated within this increased radius compared to unplated microelectrodes. We suggest that a new approach to DBS, one that uses multiple high-surface area microelectrodes, may be more therapeutically effective due to increased neuronal activation.

Arcot Desai, Sharanya; Gutekunst, Claire-Anne; Potter, Steve M.; Gross, Robert E.

2014-01-01

171

Deep brain stimulation macroelectrodes compared to multiple microelectrodes in rat hippocampus.  

PubMed

Microelectrode arrays (wire diameter <50 ?m) were compared to traditional macroelectrodes for deep brain stimulation (DBS). Understanding the neuronal activation volume may help solve some of the mysteries associated with DBS, e.g., its mechanisms of action. We used c-fos immunohistochemistry to investigate neuronal activation in the rat hippocampus caused by multi-micro- and macroelectrode stimulation. At ± 1V stimulation at 25 Hz, microelectrodes (33 ?m diameter) had a radius of activation of 100 ?m, which is 50% of that seen with 150 ?m diameter macroelectrode stimulation. Macroelectrodes activated about 5.8 times more neurons than a single microelectrode, but displaced ~20 times more neural tissue. The sphere of influence of stimulating electrodes can be significantly increased by reducing their impedance. By ultrasonic electroplating (sonicoplating) the microelectrodes with platinum to increase their surface area and reduce their impedance by an order of magnitude, the radius of activation increased by 50 ?m and more than twice the number of neurons were activated within this increased radius compared to unplated microelectrodes. We suggest that a new approach to DBS, one that uses multiple high-surface area microelectrodes, may be more therapeutically effective due to increased neuronal activation. PMID:24971060

Arcot Desai, Sharanya; Gutekunst, Claire-Anne; Potter, Steve M; Gross, Robert E

2014-01-01

172

Motor and Non-motor Effects of PPN-DBS in PD Patients: Insights from Intra-operative Electrophysiology  

Microsoft Academic Search

\\u000a Three decades of basic research have focused on the multiple functions sub-served by the pedunculopontine nucleus (PPN) in\\u000a mammals. Yet, far from understood is the impact that lesioning PPN or modulating PPN-fugal pathways have on motor, limbic\\u000a and\\/or associative domains. Recently, we have pioneered the low-frequency deep brain stimulation (DBS) of pontine tegmental\\u000a areas in severely parkinsonian patients, aiming at

Alessandro Stefani; Salvatore Galati; Mariangela Pierantozzi; Antonella Peppe; Livia Brusa; Vincenzo Moschella; Francesco Marzetti; Paolo Stanzione

173

Polarisation converters for a DBS flat-plate antenna  

Microsoft Academic Search

The introduction of direct broadcast by satellite service requires suitable receiving antennas to be available. A polarization converter and an array of linearly-polarized elements have been found to be the most suitable way of receiving the circularly-polarized radiation that would be transmitted by a DBS satellite. In this Report the performance of various types of polarization converters is considered. It

M. C. D. Maddocks; D. H. Boardman

1988-01-01

174

A locked, non-rotating, completely embedded, moveable electrode for chronic brain stimulation studies in freely moving, fighting rats.  

PubMed

A light-weight, yet rugged moveable electrode assembly is described for chronic brain stimulation studies in small-brained animals. The assembly can be completely embedded in a smooth, unobtrusive dental cement cap and is therefore suitable for use in fighting experiments, where collisions with partners and cage walls will limit the use of other assemblies. It permits a variable electrode distance penetration of 3 mm in 75 mu-steps by using a separate unlocking turning-key. This design excludes the possibility of inadvertent displacement of the electrode tips by the animal itself. Since the electrode itself does not rotate during displacement, extra damage arising from possible eccentricity is avoided. The assembly has been used in a number of hypothalamic penetrations, demonstrating its usefulness and reliability. PMID:6685324

van der Poel, A M; van der Hoef, H; Meelis, W; Vletter, G; Mos, J; Kruk, M R

1983-08-01

175

The influence of US foreign DBS policy on Indian DBS TV: a case study of policy transfer  

Microsoft Academic Search

By and large academics and professional analysts disagree over the efficacy of US Congressional fora to facilitate policy transfer in terms of influencing foreign countries to privatize their local and national markets. This study addresses the issue of policy transfer within the context of the Indian (direct broadcast satellite) DBS television regulatory framework. Specifically, a link is drawn between two

Siddhartha Menon

2001-01-01

176

Clinical Cases where Lesion Therapy Was Chosen over Deep Brain Stimulation  

Microsoft Academic Search

Deep brain stimulation (DBS) surgery has become the gold standard for treatment of select refractory cases of Parkinson disease and essential tremor. Despite the usefulness of DBS surgery in many cases, there remain situations where lesion therapy (subthalamotomy, pallidotomy or thalamotomy) may provide a reasonable alternative to DBS. We reviewed the University of Florida Institutional Review Board-approved database for movement

Amanda K. Hooper; Michael S. Okun; Kelly D. Foote; Hubert H. Fernandez; Charles Jacobson; Pamela Zeilman; Janet Romrell; Ramon L. Rodriguez

2008-01-01

177

Comparison of Different Targeting Methods for Subthalamic Nucleus Deep Brain Stimulation  

Microsoft Academic Search

The subthalamic nucleus (STN) has been adopted as a commonly used surgical target in deep brain stimulation (DBS) procedures for the treatment of Parkinson's disease. Many techniques have been developed to facilitate STN DBS targeting, and consequently to improve the surgical outcome. In this work, we conducted a retrospective study on 10 patients who were treated with bilateral STN DBS

Ting Guo; Kirk W. Finnis; Sean C. L. Deoni; Andrew G. Parrent; Terry M. Peters

2006-01-01

178

Utilizing Fast Spin Echo MRI to Reduce Image Artifacts and Improve Implant/Tissue Interface Detection in Refractory Parkinson's Patients with Deep Brain Stimulators  

PubMed Central

Introduction. In medically refractory Parkinson's disease (PD) deep-brain stimulation (DBS) is an effective therapeutic tool. Postimplantation MRI is important in assessing tissue damage and DBS lead placement accuracy. We wanted to identify which MRI sequence can detect DBS leads with smallest artifactual signal void, allowing better tissue/electrode edge conspicuity. Methods. Using an IRB approved protocol 8 advanced PD patients were imaged within MR conditional safety guidelines at low RF power (SAR ? 0.1?W/kg) in coronal plane at 1.5T by various sequences. The image slices were subjectively evaluated for diagnostic quality and the lead contact diameters were compared to identify a sequence least affected by metallic leads. Results and Discussion. Spin echo and fast spin echo based low SAR sequences provided acceptable image quality with comparable image blooming (enlargement) of stimulator leads. The mean lead diameters were 2.2 ± 0.1?mm for 2D, 2.1 ± 0.1?mm for 3D, and 4.0 ± 0.2?mm for 3D MPRAGE sequence. Conclusion. Low RF power spin echo and fast spin echo based 2D and 3D FSE sequences provide acceptable image quality adjacent to DBS leads. The smallest artifactual blooming of stimulator leads is present on 3D FSE while the largest signal void appears in the 3D MPRAGE sequence.

Sarkar, Subhendra N.; Sarkar, Pooja R.; Rojas, Rafael R.

2014-01-01

179

Electrical Stimulation of NIH-3T3 Cells with Platinum-PEDOT-Electrodes Integrated in a Bioreactor.  

PubMed

The objective of this work involves the development and integration of electrodes for the electrical stimulation of cells within a bioreactor. Electrodes need to fit properties such as biocompatibility, large reversible charge transfer and high flexibility in view of their future application as implants on the tympanic membrane. Flexible thin-film platinum-poly(3,4-ethylene-dioxythiophene)-electrodes on a poly(ethylene terephthalate)-foil manufactured using microsystems technology were integrated into a bioreactor based on the design of a 24 well plate. The murine fibroblast cell line NIH-3T3 was cultured on the foil electrodes and the cells were stimulated with direct voltage and unipolar pulsed voltage. The amplitude, the pulse length and the ratio of pulse to pause were varied. The stimulated cells were stained in order to determine the angle between the cell cleavage plane of the dividing cells and the vector of the electric field. These angles were subsequently used to calculate the polarization index, which is a measure of the orientation of the metaphase plane of dividing cells that occurs for example during wound healing or embryonic morphogenesis. PMID:24358059

Blume, Grit; Müller-Wichards, Wiebke; Goepfert, Christiane; Pörtner, Ralf; Müller, Jörg

2013-01-01

180

Dependence of Dbl and Dbs Transformation on MEK and NF-kB Activation  

Microsoft Academic Search

Dbs was identified initially as a transforming protein and is a member of the Dbl family of proteins (>20 mammalian members). Here we show that Dbs, like its rat homolog Ost and the closely related Dbl, exhibited guanine nucleotide exchange activity for the Rho family members RhoA and Cdc42, but not Rac1, in vitro. Dbs transforming activity was blocked by

IAN P. WHITEHEAD; QUE T. LAMBERT; JUDITH A. GLAVEN; KARON ABE; KENT L. ROSSMAN; GWENDOLYN M. MAHON; JAMES M. TRZASKOS; ROBERT KAY

1999-01-01

181

Perceptual changes in place of stimulation with long cochlear implant electrode arrays  

PubMed Central

Long (31.5?mm) electrode arrays are inserted deeper into the cochlea than the typical 1.25 turn insertion. With these electrode arrays, the apical electrodes are closer to (and possibly extend past) the end of the spiral ganglion. Using multi-dimensional scaling with patients implanted with a 31.5?mm electrode array, the perceptual space between electrodes was measured. The results suggest that deeper insertion increases the range of place pitches, but the perceptual differences between adjacent electrodes become smaller in the apex.

Landsberger, David M.; Mertens, Griet; Punte, Andrea Kleine; Van De Heyning, Paul

2014-01-01

182

Combined pedunculopontine-subthalamic stimulation in Parkinson disease  

PubMed Central

Objective: To assess the effect of deep brain stimulation (DBS) in the pedunculopontine nucleus (PPN) and caudal zona incerta (cZi)—both separately and in combination—on motor symptoms and regional cerebral blood flow (rCBF) in patients with Parkinson disease (PD). Methods: Four patients with bilateral cZi and PPN DBS electrodes were rated with the Unified Parkinson's Disease Rating Scale motor subscale (UPDRS-III) when taking and withdrawn from medication. A block of 16 [15O]-H2O PET resting measurements of rCBF were performed in 4 different states with patients withdrawn from medication: 1) no stimulation, 2) cZi stimulation alone, 3) PPN stimulation alone, 4) combined PPN/cZi stimulation. Results: When patients were medicated, combined PPN/cZi stimulation produced a statistically significant improvement in UPDRS-III score compared to cZi stimulation alone. In the “off” medication state, the clinical effect of combined stimulation was not significantly different from that induced by cZi stimulation alone. Concomitant PPN/cZi stimulation had a cumulative effect on levels of rCBF, effectively combining subcortical and cortical changes induced by stimulation of either target in isolation. Conclusions: These findings suggest that concomitant low frequency stimulation of PPN and cZi regions induces additive brain activation changes and provides improved control of PD symptoms when medicated. Classification of evidence: This study provides Class IV evidence that concomitant low frequency stimulation of PPN and cZI improves motor symptoms in patients with PD on dopamine replacement. It provides Class III evidence that concomitant low frequency stimulation of PPN and cZi induces additive rCBF changes in motor areas of brain.

Khan, S.; Gill, S.S.; Mooney, L.; White, P.; Whone, A.; Brooks, D.J.

2012-01-01

183

Optimized beamforming for simultaneous MEG and intracranial local field potential recordings in deep brain stimulation patients  

PubMed Central

Insight into how brain structures interact is critical for understanding the principles of functional brain architectures and may lead to better diagnosis and therapy for neuropsychiatric disorders. We recorded, simultaneously, magnetoencephalographic (MEG) signals and subcortical local field potentials (LFP) in a Parkinson's disease (PD) patient with bilateral deep brain stimulation (DBS) electrodes in the subthalamic nucleus (STN). These recordings offer a unique opportunity to characterize interactions between the subcortical structures and the neocortex. However, high-amplitude artefacts appeared in the MEG. These artefacts originated from the percutaneous extension wire, rather than from the actual DBS electrode and were locked to the heart beat. In this work, we show that MEG beamforming is capable of suppressing these artefacts and quantify the optimal regularization required. We demonstrate how beamforming makes it possible to localize cortical regions whose activity is coherent with the STN-LFP, extract artefact-free virtual electrode time-series from regions of interest and localize cortical areas exhibiting specific task-related power changes. This furnishes results that are consistent with previously reported results using artefact-free MEG data. Our findings demonstrate that physiologically meaningful information can be extracted from heavily contaminated MEG signals and pave the way for further analysis of combined MEG-LFP recordings in DBS patients.

Litvak, Vladimir; Eusebio, Alexandre; Jha, Ashwani; Oostenveld, Robert; Barnes, Gareth R.; Penny, William D.; Zrinzo, Ludvic; Hariz, Marwan I.; Limousin, Patricia; Friston, Karl J.; Brown, Peter

2010-01-01

184

Intact Lexicon Running Slowly - Prolonged Response Latencies in Patients with Subthalamic DBS and Verbal Fluency Deficits  

PubMed Central

Background Verbal Fluency is reduced in patients with Parkinson’s disease, particularly if treated with deep brain stimulation. This deficit could arise from general factors, such as reduced working speed or from dysfunctions in specific lexical domains. Objective To test whether DBS-associated Verbal Fluency deficits are accompanied by changed dynamics of word processing. Methods 21 Parkinson’s disease patients with and 26 without deep brain stimulation of the subthalamic nucleus as well as 19 healthy controls participated in the study. They engaged in Verbal Fluency and (primed) Lexical Decision Tasks, testing phonemic and semantic word production and processing time. Most patients performed the experiments twice, ON and OFF stimulation or, respectively, dopaminergic drugs. Results Patients generally produced abnormally few words in the Verbal Fluency Task. This deficit was more severe in patients with deep brain stimulation who additionally showed prolonged response latencies in the Lexical Decision Task. Slowing was independent of semantic and phonemic word priming. No significant changes of performance accuracy were obtained. The results were independent from the treatment ON or OFF conditions. Conclusion Low word production in patients with deep brain stimulation was accompanied by prolonged latencies for lexical decisions. No indication was found that the latter slowing was due to specific lexical dysfunctions, so that it probably reflects a general reduction of cognitive working speed, also evident on the level of Verbal Fluency. The described abnormalities seem to reflect subtle sequelae of the surgical procedure for deep brain stimulation rather than of the proper neurostimulation.

Ehlen, Felicitas; Krugel, Lea K.; Vonberg, Isabelle; Schoenecker, Thomas; Kuhn, Andrea A.; Klostermann, Fabian

2013-01-01

185

Deep Brain Stimulation for Movement Disorders  

PubMed Central

Stereotactic technique and the introduction of deep brain stimulation (DBS) can be considered two milestones in the field of surgical neuromodulation. At present the role of DBS in the treatment of clinically and epidemiologically relevant movement disorders is widely accepted and DBS procedures are performed in many clinical centers worldwide. Here we review the current state of the art of DBS treatment for the most common movement disorders: Parkinson’s disease, essential tremor, and dystonia. In this review, we give a brief description of the candidate patient selection criteria, the different anatomical targets for each of these condition, and the expected outcomes as well as possible side effects.

Pizzolato, Gilberto; Mandat, Tomasz

2012-01-01

186

[Deep brain stimulation in psychiatry: ethical aspects].  

PubMed

Deep brain stimulation (DBS) has been shown to be an efficacious treatment for many neurological conditions and has thus been expanded to psychiatric diseases as well. Following an introduction on the history of DBS in psychiatry, this review summarizes commonly raised ethical concerns and questions on clinical trial design, selection of patients, informed consent and concerns about the possible impact of DBS on an individual's personality. Finally, it highlights the fact that critique on DBS in psychiatry is probably not selectively based on scientific concerns about potential risks; instead, the neurobiological origin of specific psychiatric disorders has been questioned. PMID:24983574

Müller, Ulf J; Bogerts, Bernhard; Voges, Jürgen; Galazky, Imke; Kohl, Sina; Heinze, Hans-Jochen; Kuhn, Jens; Steiner, Johann

2014-07-01

187

A case of tremor reduction and almost complete ageusia under bilateral thalamic (VIM) deep brain stimulation in essential tremor--a therapeutic dilemma.  

PubMed

Essential tremor (ET) is a neurological disorder that can be treated effectively by means of bilateral thalamic ventral intermediate nucleus (VIM) deep brain stimulation (DBS). We present a rare case of stimulation-dependent reversible ageusia that poses a therapeutic dilemma on the one hand and serves as an instructive example to elucidate the as yet incompletely defined gustatory pathways on the other. A 69-year-old patient with successful reduction of his disabling upper extremity ET experienced an almost complete but during stimulation cessation reversible ageusia under bilateral VIM DBS. An evaluation of diffusion tensor (DTI) neuroimaging studies was performed in order to detect effective electrode positions and volumes of activated tissue (VTA) in relation to the medial lemniscus (ML) and dentato-rubro-thalamic tract (DRT). Repeated subjective gustometry was conducted with differential manipulation of stimulation settings. This case report stresses the importance of fiber tracts for DBS surgery. Reconciled with previous findings in lesion cases, we assume the coexistence of decussating and non-decussating fibers in the gustatory tract combined with hemispheric dominance in the processing of gustatory information. A therapeutic option for this dilemma may be a patient-selectable stimulation program or bipolar stimulation establishing a smaller ovoid VTA. PMID:21984073

Sajonz, Bastian; Mädler, Burkhard; Herberhold, Stephan; Paus, Sebastian; Coenen, Volker A

2011-12-01

188

Novel thin film titanium nitride micro-electrodes with excellent charge transfer capability for cell stimulation and sensing applications  

Microsoft Academic Search

Microelectrodes with high specific charge transfer capability are an important prerequisite for high resolution stimulation, and recording of neuronal and muscular tissue. Novel thin film titanium nitride (TiN) microelectrodes were fabricated onto a microelectrode array by reactive sputtering in a nitrogen\\/argon atmosphere. The electrodes showed excellent charge transfer capacity of 40 mC\\/cm2 and low ac-impedance along with high pulse stability.

M. Janders; U. Egert; M. Stelzle; W. Nisch

1996-01-01

189

Analysis of Stereotactic Accuracy of the Cosman-Robert-Wells Frame and Nexframe Frameless Systems in Deep Brain Stimulation Surgery  

Microsoft Academic Search

Introduction: The primary goal of stereotactic systems in deep brain stimulation (DBS) surgery is accurate delivery of a DBS lead to a target identified on imaging. Thus, it is critical to understand the accuracy of the stereotactic systems and the factors which may be associated with a decrease in accuracy. Methods: Ninety patients underwent microelectrode recording-guided placement of 139 DBS

Craig Kelman; V. Ramakrishnan; Alex Davies; Kathryn Holloway

2010-01-01

190

Nonmotor outcomes in Parkinson's disease: is deep brain stimulation better than dopamine replacement therapy?  

PubMed Central

Nonmotor symptoms are an integral part of Parkinson’s disease and cause significant morbidity. Pharmacological therapy helps alleviate the disease but produces nonmotor manifestations. While deep brain stimulation (DBS) has emerged as the treatment of choice for motor dysfunction, the effect on nonmotor symptoms is not well known. Compared with pharmacological therapy, bilateral subthalamic nucleus (STN)-DBS or globus pallidum interna (GPi)-DBS has significant beneficial effects on pain, sleep, gastrointestinal and urological symptoms. STN-DBS is associated with a mild worsening in verbal fluency while GPi-DBS has no effect on cognition. STN-DBS may improve cardiovascular autonomic disturbances by reducing the dose of dopaminergic drugs. Because the motor effects of STN-DBS and GPi-DBS appear to be similar, nonmotor symptoms may determine the target choice in surgery of future patients.

Kandadai, Rukmini Mridula; Jabeen, Afshan; Kannikannan, Meena A.

2012-01-01

191

The control of neural cell-to-cell interactions through non-contact electrical field stimulation using graphene electrodes.  

PubMed

Electric field stimulation has become one of the most promising therapies for a variety of neurological diseases. However, the safety and effectiveness of the stimulator are critical in determining the outcome. Because there are few safe and effective in vivo and/or in vitro stimulator devices, we demonstrate a method that allows for non-contact electric field stimulation with a specific strength that is able to control cell-to-cell interaction in vitro. Graphene, a form of graphite, and polyethylene terephthalate (PET) was used to create a non-cytotoxic in vitro graphene/PET film stimulator. A transient non-contact electric field was produced by charge-balanced biphasic stimuli through the graphene/PET film electrodes and applied to cultured neural cells. We found that weak electric field stimulation (pulse duration of 10 s) as low as 4.5 mV/mm for 32 min was particularly effective in shaping cell-to-cell interaction. Under weak electric field stimulation, we observed a significant increase in the number of cells forming new cell-to-cell couplings and in the number of cells strengthening existing cell-to-cell couplings. The underlying mechanism of the altered cellular interactions may be related to an altered regulation of the endogenous cytoskeletal proteins fibronectin, actin, and vinculin. In conclusion, this technique may open a new therapeutic approach for augmenting cell-to-cell coupling in cell transplantation therapy in the central nervous system. PMID:20880583

Heo, Chaejeong; Yoo, Jeongwan; Lee, Siyoung; Jo, Areum; Jung, Susie; Yoo, Hyosun; Lee, Young Hee; Suh, Minah

2011-01-01

192

Estimation of electrode location in a rat motor cortex by laminar analysis of electrophysiology and intracortical electrical stimulation  

NASA Astrophysics Data System (ADS)

While the development of microelectrode arrays has enabled access to disparate regions of a cortex for neurorehabilitation, neuroprosthetic and basic neuroscience research, accurate interpretation of the signals and manipulation of the cortical neurons depend upon the anatomical placement of the electrode arrays in a layered cortex. Toward this end, this report compares two in vivo methods for identifying the placement of electrodes in a linear array spaced 100 µm apart based on in situ laminar analysis of (1) ketamine-xylazine-induced field potential oscillations in a rat motor cortex and (2) an intracortical electrical stimulation-induced movement threshold. The first method is based on finding the polarity reversal in laminar oscillations which is reported to appear at the transition between layers IV and V in laminar 'high voltage spindles' of the rat cortical column. Analysis of histological images in our dataset indicates that polarity reversal is detected 150.1 ± 104.2 µm below the start of layer V. The second method compares the intracortical microstimulation currents that elicit a physical movement for anodic versus cathodic stimulation. It is based on the hypothesis that neural elements perpendicular to the electrode surface are preferentially excited by anodic stimulation while cathodic stimulation excites those with a direction component parallel to its surface. With this method, we expect to see a change in the stimulation currents that elicits a movement at the beginning of layer V when comparing anodic versus cathodic stimulation as the upper cortical layers contain neuronal structures that are primarily parallel to the cortical surface and lower layers contain structures that are primarily perpendicular. Using this method, there was a 78.7 ± 68 µm offset in the estimate of the depth of the start of layer V. The polarity reversal method estimates the beginning of layer V within ±90 µm with 95% confidence and the intracortical stimulation method estimates it within ±69.3 µm. We propose that these methods can be used to estimate the in situ location of laminar electrodes implanted in the rat motor cortex.

Yazdan-Shahmorad, A.; Lehmkuhle, M. J.; Gage, G. J.; Marzullo, T. C.; Parikh, H.; Miriani, R. M.; Kipke, D. R.

2011-08-01

193

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

NASA Astrophysics Data System (ADS)

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.

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

2011-02-01

194

An electronic device for artefact suppression in human local field potential recordings during deep brain stimulation  

NASA Astrophysics Data System (ADS)

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

Rossi, L.; Foffani, G.; Marceglia, S.; Bracchi, F.; Barbieri, S.; Priori, A.

2007-06-01

195

Effects of dopaminergic and subthalamic stimulation on musical performance.  

PubMed

Although subthalamic-deep brain stimulation (STN-DBS) is an efficient treatment for Parkinson's disease (PD), its effects on fine motor functions are not clear. We present the case of a professional violinist with PD treated with STN-DBS. DBS improved musical articulation, intonation and emotional expression and worsened timing relative to a timekeeper (metronome). The same effects were found for dopaminergic treatment. These results suggest that STN-DBS, mimicking the effects of dopaminergic stimulation, improves fine-tuned motor behaviour whilst impairing timing precision. PMID:23232663

van Vugt, Floris T; Schüpbach, Michael; Altenmüller, Eckart; Bardinet, Eric; Yelnik, Jérôme; Hälbig, Thomas D

2013-05-01

196

Deep Brain Stimulation of the Ventral Capsule/Ventral Striatum for Treatment-Resistant Depression  

PubMed Central

Background We investigated the use of deep brain stimulation (DBS) of the ventral capsule/ventral striatum (VC/VS) for treatment refractory depression. Methods Fifteen patients with chronic, severe, highly refractory depression received open-label DBS at three collaborating clinical sites. Electrodes were implanted bilaterally in the VC/VS region. Stimulation was titrated to therapeutic benefit and the absence of adverse effects. All patients received continuous stimulation and were followed for a minimum of 6 months to longer than 4 years. Outcome measures included the Hamilton Depression Rating Scale—24 item (HDRS), the Montgomery-Asberg Depression Rating Scale (MADRS), and the Global Assessment of Function Scale (GAF). Results Significant improvements in depressive symptoms were observed during DBS treatment. Mean HDRS scores declined from 33.1 at baseline to 17.5 at 6 months and 14.3 at last follow-up. Similar improvements were seen with the MADRS (34.8, 17.9, and 15.7, respectively) and the GAF (43.4, 55.5, and 61.8, respectively). Responder rates with the HDRS were 40% at 6 months and 53.3% at last follow-up (MADRS: 46.7% and 53.3%, respectively). Remission rates were 20% at 6 months and 40% at last follow-up with the HDRS (MADRS: 26.6% and 33.3%, respectively). The DBS was well-tolerated in this group. Conclusions Deep brain stimulation of the VC/VS offers promise for the treatment of refractory major depression.

Malone, Donald A.; Dougherty, Darin D.; Rezai, Ali R.; Carpenter, Linda L.; Friehs, Gerhard M.; Eskandar, Emad N.; Rauch, Scott L.; Rasmussen, Steven A.; Machado, Andre G.; Kubu, Cynthia S.; Tyrka, Audrey R.; Price, Lawrence H.; Stypulkowski, Paul H.; Giftakis, Jonathon E.; Rise, Mark T.; Malloy, Paul F.; Salloway, Stephen P.; Greenberg, Benjamin D.

2012-01-01

197

Predictive factors of speech intelligibility following subthalamic nucleus stimulation in consecutive patients with Parkinson's disease.  

PubMed

Speech changes after bilateral subthalamic nucleus deep brain stimulation (STN-DBS) can be variable, with the majority of patients experiencing speech deterioration over time. The aim of this study was to describe the perceptual characteristics of speech following chronic STN-DBS and to analyze clinical and surgical factors that could predict speech change. Fifty-four consecutive patients (34 men; mean age ± standard deviation (SD), 58.8 ± 6.3 years; mean ± SD disease duration, 12.5 ± 4.7 years; mean ± SD levodopa equivalent, 1556 ± 671 mg/day; mean ± SD Unified Parkinson's Disease Rating Scale motor part (UPDRS-III) off-medication score, 48.1 ± 17.9 [range, 20-89]; and mean ± SD UPDRS-III on-medication score, 12.4 ± 7.8 [range, 2-31]) participated in this study. They were assessed before and at 1 year after surgery using the Assessment of Intelligibility for the Dysarthric Speech, the perceptual scale from Darley et al., and the UPDRS-III. Speech intelligibility deteriorated on average by 14.4% (P = 0.0006) after 1 year of STN-DBS when off-medication and by 12.3% (P = 0.001) when on-medication. The effect on speech was not linked to age at surgery, unlike the effect on motor outcome. The most significant predictive factors for deterioration of speech intelligibility when patients were off-medication/on-stimulation were lower preoperative speech intelligibility on-medication, longer disease duration, and medially placed left hemisphere active electrode contact. Speech change after STN-DBS is variable and multifactorial. Consistent preoperative speech evaluation would help inform patients about the possible effects of surgery. Appropriate consideration of speech deficits might assist surgical targeting, particularly of the left electrode. © 2014 International Parkinson and Movement Disorder Society. PMID:24532491

Tripoliti, Elina; Limousin, Patricia; Foltynie, Tom; Candelario, Joseph; Aviles-Olmos, Iciar; Hariz, Marwan I; Zrinzo, Ludvic

2014-04-01

198

Improvement of Electrical Stimulation Protocol for Simultaneous Measurement of Extracellular Potential with On-Chip Multi-Electrode Array System  

NASA Astrophysics Data System (ADS)

Cardiotoxicity testing with a multi-electrode array (MEA) system requires the stable beating of cardiomyocytes for the measurement of the field potential duration (FPD), because different spontaneous beating rates cause different responses of FPD prolongation induced by drugs, and the beating rate change effected by drugs complicates the FPD prolongation assessment. We have developed an on-chip MEA system with electrical stimulation for the measurement of the FPD during the stable beating of human embryonic stem (ES) cell-derived cardiomyocyte clusters. Using a conventional bipolar stimulation protocol, we observed such large artifacts in electrical stimulation that we could not estimate the FPD quantitatively. Therefore, we improved the stimulation protocol by using sequential rectangular pulses in which the positive and negative stimulation voltages and number of pulses could be changed flexibly. The balanced voltages and number of pulses for sequential rectangular pulses enabled the recording of small negative artifacts only, which hardly affected the FPD measurement of human-ES-cell-derived cardiomyocyte clusters. These conditions of electrical stimulation are expected to find applications for the control of constant beating for cardiotoxicity testing.

Kaneko, Tomoyuki; Nomura, Fumimasa; Hattori, Akihiro; Yasuda, Kenji

2012-06-01

199

The temporal pattern of stimulation may be important to the mechanism of deep brain stimulation  

PubMed Central

Deep brain stimulation (DBS) has emerged as an important and potentially powerful treatment option for the management of carefully selected patients with advanced Parkinson's disease (PD) who are not adequately controlled by standard medication therapy. Though considerable advances have been made, the mechanisms underlying the therapeutic effects of DBS remain unclear despite its clinical efficacy. It is now widely held that both excitation and inhibition can occur secondary to stimulation, and it is suspected that abnormal synchronized oscillations may also be important in the mechanism of DBS. Other potentially important processes, including blood flow changes, local and upstream neurogenesis, and the modulation of neurotransmitters through stimulation of bordering astrocytes are also being investigated. Recent research has suggested that the temporal pattern of DBS stimulation is also an important variable in DBS neuromodulation, yet the extent of its influence on DBS efficacy has yet to be determined. As high stimulation frequency alone does not appear to be sufficient for optimal symptom suppression, attention to stimulation pattern might lead to more effective symptom control and reduced side effects, possibly at a lower frequency. Stimulation pattern may be potentially amenable to therapeutic modulation and its role in the clinical efficacy of DBS should be addressed through further focus and research.

Hess, Christopher W.; Vaillancourt, David E.; Okun, Michael S.

2013-01-01

200

Complication Avoidance and Management in Deep Brain Stimulation Surgery  

Microsoft Academic Search

\\u000a A number of recent publications have reviewed complications of deep brain stimulation (DBS) implantation (1–11). A summary of the author's peri-operative and device-related complications using Medtronic DBS hardware is provided in Table\\u000a 7.1. This is based on a series of 637 new DBS leads in 358 patients implanted by a single surgeon (PAS). Procedures were performed\\u000a with frame-based stereotaxy using

Philip A. Starr; Karl Sillay

201

Object discrimination with an artificial hand using electrical stimulation of peripheral tactile and proprioceptive pathways with intrafascicular electrodes.  

PubMed

Trans-radial amputee subjects were implanted with intrafascicular electrodes in the stumps of the median and ulnar nerves. Electrical stimulation through these electrodes was used to provide sensations of touch and finger position referred to the amputated hand. Two subjects were asked to identify different objects as to size and stiffness by manipulating them with a myo-electric hand without visual or auditory cues. Both subjects were provided with information about contact force with the objects via tactile sensations referred to their phantom hands. One subject, who was provided with information about finger position in the prosthetic hand via a different tactile sensation referred to his phantom hand, was unable to correctly identify the objects. The other subject, who received information about finger position via a proprioceptive sensation referred to his phantom hand, correctly identified the objects at a level statistically significantly above chance performance. PMID:21859607

Horch, Kenneth; Meek, Sanford; Taylor, Tyson G; Hutchinson, Douglas T

2011-10-01

202

Activation of subthalamic neurons by contralateral subthalamic deep brain stimulation in Parkinson disease.  

PubMed

Multiple studies have shown bilateral improvement in motor symptoms in Parkinson disease (PD) following unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) and internal segment of the globus pallidus, yet the mechanism(s) underlying this phenomenon are poorly understood. We hypothesized that STN neuronal activity is altered by contralateral STN DBS. This hypothesis was tested intraoperatively in humans with advanced PD using microelectrode recordings of the STN during contralateral STN DBS. We demonstrate alterations in the discharge pattern of STN neurons in response to contralateral STN DBS including short latency, temporally precise, stimulation frequency-independent responses consistent with antidromic activation. Furthermore, the total discharge frequency during contralateral high frequency stimulation (160 Hz) was greater than during low frequency stimulation (30 Hz) and the resting state. These findings demonstrate complex responses to DBS and imply that output activation throughout the basal ganglia-thalamic-cortical network rather than local inhibition is a therapeutic mechanism of DBS. PMID:21177996

Walker, Harrison C; Watts, Ray L; Schrandt, Christian J; Huang, He; Guthrie, Stephanie L; Guthrie, Barton L; Montgomery, Erwin B

2011-03-01

203

Update on deep brain stimulation.  

PubMed

Deep brain stimulation (DBS) is a commonly used neurosurgical form of therapeutic brain stimulation that has been demonstrated to be safe, well tolerated, and effective for the treatment of essential tremor, Parkinson's disease, and primary dystonia. These particular uses have been approved by the U.S. Food and Drug Administration (FDA). Investigational studies using DBS have been conducted for refractory epilepsy, obesity, chronic pain, tardive dyskinesia, Tourette syndrome, and other movement disorders, but none of these studies has led to FDA approval for these indications. Although the use of DBS has been approved by the FDA under a Humanitarian Device Exemption for the treatment of treatment-resistant obsessive-compulsive disorder, studies systematically investigating the potential use of DBS for various severe chronic psychiatric disorders are in their earliest stages, and further studies are warranted. [Journal of Psychosocial Nursing and Mental Health Services, 52(4), 23-26.]. PMID:24702284

Howland, Robert H

2014-04-01

204

Would an endosteal CI-electrode make sense? Comparison of the auditory nerve excitability from different stimulation sites using ESRT measurements and mathematical models.  

PubMed

Regarding potential endosteal cochlear implant electrodes, the primary goal of this paper is to compare different intra- and extra-cochlear stimulation sites in terms of current strengths needed for stimulating the auditory nerve. Our study was performed during routine cochlear implantation using needle electrodes for electric stimulation and by visually recording electrically elicited stapedius reflexes (ESRT) as a measure for the stimulus transfer. Of course this rather simple setup only allows rough estimations, which, however, may provide further arguments whether or not to proceed with the concept of an endosteal electrode. In addition, a mathematical model is being developed. In a pilot study, intra-operative electric stimuli were applied via a needle electrode commonly used for the promontory stimulation test. Thus, stapedius reflex thresholds (ESRTs), electrically elicited via the needle from different points inside and outside the cochlea served as indicators for the suitability of different electrode positions towards the modiolus. Tests were performed on 11 CI-recipients. In addition, the extension of electrical fields from different stimulation sites is simulated in a mathematical cochlea model. In most patients ESRT measurements could be performed and evaluated. Thus an "endosteal" stimulation seems possible, although the current intensities must be higher than at intraluminal stimulation sites. Moreover, our model calculations confirm that the extension of electric fields is less favourable with increasing distance from the electrode to the ganglion nerve cells. In terms of hearing, the concept of an endosteal electrode should only be promoted, if its superiority for hearing preservation can be proven, e.g. in animal experiments. However, for other indications like the electric suppression of tinnitus, further research seems advisable. Levels of evidence: N/A. PMID:23657576

Pau, Hans Wilhelm; Grünbaum, Annekathrin; Ehrt, Karsten; Dahl, Rüdiger; Just, Tino; van Rienen, Ursula

2014-06-01

205

Hindlimb movement in the cat induced by amplitude-modulated stimulation using extra-spinal electrodes  

NASA Astrophysics Data System (ADS)

Hindlimb movement in the cat induced by electrical stimulation with an amplitude-modulated waveform of the dorsal surface of the L5-S1 spinal cord or the L5-S1 dorsal/ventral roots was investigated before and after acute spinal cord transection at the T13-L1 level. Stimulation of the spinal cord or dorsal/ventral root at the same spinal segment induced similar movements including coordinated multi-joint flexion or extension. The induced movements changed from flexion to extension when the stimulation was moved from rostral (L5) to caudal (S1) spinal segments. Stimulation of a dorsal or ventral root on one side induced only ipsilateral hindlimb movement. However, stimulation on the dorsal surface of the spinal cord along the midline or across the spinal cord induced bilateral movements. The extension induced by stimulation of L7 dorsal root produced the largest ground reaction force that was strong enough to support body weight. Dorsal root stimulation induced a larger ground reaction force than ventral root stimulation and produced a more graded recruitment curve. Stepping at different speeds could be generated by combined stimulation of the rostral (L5) and the caudal (L6/L7) spinal segments with an appropriate timing between the different stimulation channels. Acute transection of the spinal cord did not change the responses indicating that the induced movements did not require the involvement of the supraspinal locomotor centers. The methods and the stimulation strategy developed in this study might be utilized to restore locomotor function after spinal cord injury.

Tai, Changfeng; Wang, Jicheng; Shen, Bing; Wang, Xianchun; Roppolo, James R.; de Groat, William C.

2008-06-01

206

Virtual electrodes in cardiac tissue: a common mechanism for anodal and cathodal stimulation.  

PubMed Central

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 induces propagation from the virtual cathode, whereas stimulus termination (break) induces it from the virtual anode. In make stimulation, the virtual anode can delay activation of the underlying tissue, whereas in break stimulation this occurs under the virtual cathode. Thus make and break stimulations in cardiac tissue have a common mechanism that is the result of differences in the electrical anisotropy of the intracellular and extracellular spaces and provides clear proof of the validity of the bidomain model. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6

Wikswo, J P; Lin, S F; Abbas, R A

1995-01-01

207

Image compression and data transport alternatives for digital DBS systems  

NASA Astrophysics Data System (ADS)

This paper considers issues related to the selection of an image compression algorithm and associated data transport format for all-digital DBS systems intended for the delivery of entertainment video. Several alternative approaches are described, including: (1) standard compression algorithm (e.g., ISO MPEG) without special transport; (2) standard MPEG algorithm with satellite-specific transport; and (3) modified MPEG with priority layering of video, custom transport format based on either (A) constant bit-rate (CBR) video, or (B) variable bit-rate (VBR) video with statistical multiplexing. Trade-offs between these contending system architectures are discussed in terms of system performance, system capacity, compatibility, service flexibility and equipment cost. The discussion is supported with some performance results for an example NTSC quality TV delivery scenario, illustrating the potential image quality/capacity/graceful degradation benefits of applicable custom transport, error concealment, layering and VBR statistical multiplexing techniques.

Zdepski, J.; Raychaudhuri, D.; Schiff, L.

1992-03-01

208

Anatomical Connectivity of the Subgenual Cingulate Region Targeted with Deep Brain Stimulation for Treatment-Resistant Depression  

Microsoft Academic Search

Chronic deep brain stimulation (DBS) of subgenual cingulate white matter results in dramatic remission of symptoms in some previously treatment-resistant depression patients. The effects of stimulation may be mediated locally or via corticocortical or corticosubcortical connections. We use tractography to define the likely connectivity of cingulate regions stimulated in DBS- responsive patients using diffusion imaging data acquired in healthy control

H. Johansen-Berg; D. A. Gutman; T. E. J. Behrens; P. M. Matthews; M. F. S. Rushworth; E. Katz; A. M. Lozano; H. S. Mayberg

2008-01-01

209

Evaluation of local electric fields generated by transcranial direct current stimulation with an extracephalic reference electrode based on realistic 3D body modeling  

NASA Astrophysics Data System (ADS)

In this study, local electric field distributions generated by transcranial direct current stimulation (tDCS) with an extracephalic reference electrode were evaluated to address extracephalic tDCS safety issues. To this aim, we generated a numerical model of an adult male human upper body and applied the 3D finite element method to electric current conduction analysis. In our simulations, the active electrode was placed over the left primary motor cortex (M1) and the reference electrode was placed at six different locations: over the right temporal lobe, on the right supraorbital region, on the right deltoid, on the left deltoid, under the chin, and on the right buccinator muscle. The maximum current density and electric field intensity values in the brainstem generated by the extracephalic reference electrodes were comparable to, or even less than, those generated by the cephalic reference electrodes. These results suggest that extracephalic reference electrodes do not lead to unwanted modulation of the brainstem cardio-respiratory and autonomic centers, as indicated by recent experimental studies. The volume energy density was concentrated at the neck area by the use of deltoid reference electrodes, but was still smaller than that around the active electrode locations. In addition, the distributions of elicited cortical electric fields demonstrated that the use of extracephalic reference electrodes might allow for the robust prediction of cortical modulations with little dependence on the reference electrode locations.

Im, Chang-Hwan; Park, Ji-Hye; Shim, Miseon; Chang, Won Hyuk; Kim, Yun-Hee

2012-04-01

210

High-Frequency Stimulation of Nucleus Accumbens Changes in Dopaminergic Reward Circuit  

PubMed Central

Deep brain stimulation (DBS) of the nucleus accumbens (NAc) is a potential remedial therapy for drug craving and relapse, but the mechanism is poorly understood. We investigated changes in neurotransmitter levels during high frequency stimulation (HFS) of the unilateral NAc on morphine-induced rats. Sixty adult Wistar rats were randomized into five groups: the control group (administration of saline), the morphine-only group (systematic administration of morphine without electrode implantation), the morphine-sham-stimulation group (systematic administration of morphine with electrode implantation but not given stimulation), the morphine-stimulation group (systematic administration of morphine with electrode implantation and stimulation) and the saline-stimulation group (administration of saline with electrode implantation and stimulation). The stimulation electrode was stereotaxically implanted into the core of unilateral NAc and microdialysis probes were unilaterally lowered into the ipsilateral ventral tegmental area (VTA), NAc, and ventral pallidum (VP). Samples from microdialysis probes in the ipsilateral VTA, NAc, and VP were analyzed for glutamate (Glu) and ?-aminobutyric acid (GABA) by high-performance liquid chromatography (HPLC). The levels of Glu were increased in the ipsilateral NAc and VP of morphine-only group versus control group, whereas Glu levels were not significantly changed in the ipsilateral VTA. Furthermore, the levels of GABA decreased significantly in the ipsilateral NAc, VP, and VTA of morphine-only group when compared with control group. The profiles of increased Glu and reduced GABA in morphine-induced rats suggest that the presence of increased excitatory neurotransmission in these brain regions. The concentrations of the Glu significantly decreased while the levels of GABA increased in ipsilateral VTA, NAc, and VP in the morphine-stimulation group compared with the morphine-only group. No significant changes were seen in the morphine-sham stimulation group compared with the morphine-only group. These findings indicated that unilateral NAc stimulation inhibits the morphine-induced rats associated hyperactivation of excitatory neurotransmission in the mesocorticolimbic reward circuit.

Zhu, Honghua; Zhang, Jianguo; Sim, Moira; Ma, Yu; Wang, Wei

2013-01-01

211

Performing functional magnetic resonance imaging in patients with Parkinson's disease treated with deep brain stimulation.  

PubMed

Deep brain stimulation (DBS) is a relatively novel treatment in advanced Parkinson's disease (PD). Functional magnetic resonance imaging (fMRI) is a useful technique for examining the effects of DBS both within the basal ganglia and its cortical connectivity. There are technical difficulties in imaging patients with PD, and the DBS itself can generate image artifacts. We describe aspects related to optimizing the fMRI acquisition parameters in patients with DBS and the results of sensorimotor activation tasks performed by four PD patients during hand, foot, and tongue movements, both before and after DBS implant. Provided that all safety conditions are followed, it is possible to perform fMRI in patients with PD and DBS. The standard DBS surgical procedure has to be slightly modified in order to reduce image artifacts. The event-related design provided increased power to detect sensorimotor cortex and basal ganglia activation. PMID:16671094

Arantes, Paula R; Cardoso, Ellison F; Barreiros, Maria A; Teixeira, Manoel J; Gonçalves, Márcia R; Barbosa, Egberto R; Sukwinder, Sukhi Shergill; Leite, Claudia C; Amaro, Edson

2006-08-01

212

Effect of chronic pallidal deep brain stimulation on off period dystonia and sensory symptoms in advanced Parkinson's disease  

PubMed Central

Objective: To investigate the efficacy of chronic pallidal deep brain stimulation (DBS) on off period dystonia, cramps, and sensory symptoms in advanced Parkinson's disease (PD). Methods: 16 patients (6 women, 10 men; mean age at surgery 65 years) suffering from advanced PD were followed up prospectively for one year after implantation of a monopolar electrode in the posteroventral lateral globus pallidus internus. Unilateral DBS was performed in 9 patients. 10 patients had bilateral procedures (contemporaneous bilateral surgery in 7 and staged bilateral surgery in 3 instances). The decision whether to perform unilateral or bilateral surgery depended on the clinical presentation of the patient. Patients were formally assessed preoperatively, at 3–5 days, 3 months, and 12 months after surgery. Results: In patients who underwent unilateral surgery, pain was present in 7 (78%), off dystonia in 5 (56%), cramps in 6 (67%), and dysaesthesia in 4 (44%). In patients who underwent bilateral surgery, pain was present in 7 (70%), off dystonia in 6 (60%), cramps in 7 (70%), and dysaesthesia in 4 (40%). With unilateral DBS, contralateral off period dystonia was improved by 100% at 1 year postoperatively, pain by 74%, cramps by 88%, and dysaesthesia by 100%. There was less pronounced amelioration of ipsilateral off period dystonia and sensory symptoms. With bilateral DBS, total scores for dystonia were improved by 86%, for pain by 90%, for cramps by 90%, and for dysaesthesia by 88%. The benefit appeared early at the first evaluation 3–5 days after surgery and was stable throughout the follow up period. Conclusions: Pallidal DBS yields major improvement of off period dystonia, cramps, and sensory symptoms in patients with advanced PD.

Loher, T; Burgunder, J; Weber, S; Sommerhalder, R; Krauss, J

2002-01-01

213

Therapeutic stimulation versus ablation.  

PubMed

The renaissance of functional stereotactic neurosurgery was pioneered in the mid 1980s by Laitinen's introduction of Leksell's posteroventral pallidotomy for Parkinson´s disease (PD). This ablative procedure experienced a worldwide spread in the 1990s, owing to its excellent effect on dyskinesias and other symptoms of post-l-dopa PD. Modern deep brain stimulation (DBS), pioneered by Benabid and Pollak in 1987 for the treatment of tremor, first became popular when it was applied to the subthalamic nucleus (STN) in the mid 1990s, where it demonstrated a striking effect on all cardinal symptoms of advanced PD, and permitted reduced dosages of medication. DBS, as a nondestructive, adaptable, and reversible procedure that is proving safe in bilateral surgery on basal ganglia, has great appeal to clinicians and patients alike, despite the fact that it is expensive, laborious, and relies on very strict patient selection criteria, especially for STN DBS. Psychiatric surgery has experienced the same phenomenon, with DBS supplanting completely stereotactic ablative procedures. This chapter discusses the pros and cons of ablation versus stimulation and investigates the reasons why DBS has overshadowed proven efficient ablative procedures such as pallidotomy for PD, and capsulotomy and cingulotomy for obsessive-compulsive disorder and depression. PMID:24112885

Hariz, Marwan I; Hariz, Gun-Marie

2013-01-01

214

Laryngeal pacing in minipigs: in vivo test of a new minimal invasive transcricoidal electrode insertion method for functional electrical stimulation of the PCA.  

PubMed

Functional electrical stimulation (FES) of the posterior cricoarytenoid muscle (PCA) to restore respiratory function of the larynx may become an option for the treatment of bilateral recurrent laryngeal nerve paralysis (RLNP) in the near future. The feasibility of this has been shown in several animal trials and in a human pilot study. The common open surgical inferolateral approach for electrode insertion into the PCA for FES has a risk of damaging the recurrent laryngeal nerve (RLN) and may result in postoperative swelling and scaring of the larynx. Therefore, a minimal invasive electrode insertion technique is needed. A new miniaturized bipolar spiral tip electrode and a new electrical stimulatable insertion needle were tested in a short-term trial for an endoscopically guided and functionally controlled transcricoidal electrode insertion in eight Göttingen minipigs with bilateral normal RLN function. The feasibility of this technique was evaluated and the achieved positions of the electrodes in the PCA were analyzed using intraoperative stimulation threshold data and 3D-CT reconstructions. In seven cases it was possible to place two well-performing electrodes into the PCA. They were positioned one on either side. In one animal no functioning electrode position could be achieved because the PCA was missed. Thresholds of the electrode tips varied between 0.2 and 2.5 mA (mean 0.71 mA). In any case maximal glottal opening could be reached before adductors were co-activated. The majority of electrodes were placed into the central lower part of the PCA with no apparent correlation between threshold and electrode position. Surgical trauma might be further reduced by using endoscopy via a laryngeal mask avoiding the temporary tracheostomy used in this trial. If the implanted electrodes remain stable in long-term tests, we suggest that this method could soon be transferred into human application. PMID:22875064

Förster, Gerhard; Arnold, Dirk; Bischoff, Sabine J; Schubert, Harald; Scholle, Hans-Christoph; Müller, Andreas H

2013-01-01

215

Brittle Dyskinesia Following STN but not GPi Deep Brain Stimulation  

PubMed Central

Background The aim was to describe the prevalence and characteristics of difficult to manage dyskinesia associated with subthalamic nucleus (STN) deep brain stimulation (DBS). A small subset of STN DBS patients experience troublesome dyskinesia despite optimal programming and medication adjustments. This group of patients has been referred to by some practitioners as brittle STN DBS-induced dyskinesia, drawing on comparisons with brittle diabetics experiencing severe blood sugar regulation issues and on a single description by McLellan in 1982. We sought to describe, and also to investigate how often the “brittle” phenomenon occurs in a relatively large DBS practice. Methods An Institutional Review Board-approved patient database was reviewed, and all STN and globus pallidus internus (GPi) DBS patients who had surgery at the University of Florida from July 2002 to July 2012 were extracted for analysis. Results There were 179 total STN DBS patients and, of those, four STN DBS (2.2%) cases were identified as having dyskinesia that could not be managed without the induction of an “off state,” or by the precipitation of a severe dyskinesia despite vigorous stimulation and medication adjustments. Of 75 GPi DBS cases reviewed, none (0%) was identified as having brittle dyskinesia. One STN DBS patient was successfully rescued by bilateral GPi DBS. Discussion Understanding the potential risk factors for postoperative troublesome and brittle dyskinesia may have an impact on the initial surgical target selection (STN vs. GPI) in DBS therapy. Rescue GPi DBS therapy may be a viable treatment option, though more cases will be required to verify this observation.

Sriram, Ashok; Foote, Kelly D.; Oyama, Genko; Kwak, Joshua; Zeilman, Pam R.; Okun, Michael S.

2014-01-01

216

ControllingBurstinginCorticalCultureswithClosed-Loop Multi-ElectrodeStimulation  

Microsoft Academic Search

One of the major modes of activity of high-density cultures of dissociated neurons is globally synchronized bursting. Unlike in vivo, neuronal ensembles in culture maintain activity patterns dominated by global bursts for the lifetime of the culture (up to 2 years). We hypothesizethatpersistenceofburstingiscausedbyalackofinputfromotherbrainareas.Tostudythishypothesis,wegrewsmallbut dense monolayer cultures of cortical neurons and glia from rat embryos on multi-electrode arrays and used electrical

Daniel A. Wagenaar

217

Direct electrical stimulation of somatosensory cortex in humans using electrocorticography electrodes: a qualitative and quantitative report  

PubMed Central

Objective Recently, electrocorticography-based brain-computer interfaces have been successfully used to translate cortical activity into control signals for external devices. However, the utility of such devices would be greatly enhanced by somatosensory feedback. Direct stimulation of somatosensory cortex evokes sensory perceptions, and is thus a promising option for closing the loop. Before this can be implemented in humans it is necessary to evaluate how changes in stimulus parameters are perceived and the extent to which they can be discriminated. Approach Electrical stimulation was delivered to the somatosensory cortex of human subjects implanted with electrocorticography grids. Subjects were asked to discriminate between stimuli of different frequency and amplitude as well as to report the qualitative sensations elicited by the stimulation. Main Results In this study we show that in humans implanted with electrocorticography grids, variations in the amplitude or frequency of cortical electrical stimulation produce graded variations in percepts. Subjects were able to reliably distinguish between different stimuli. Significance These results indicate that direct cortical stimulation is a feasible option for sensory feedback with brain-computer interface devices.

Johnson, L A; Wander, J D; Sarma, D; Su, D K; Fetz, E E; Ojemann, J G

2013-01-01

218

Brain stimulation in posttraumatic stress disorder  

PubMed Central

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 reducing anxiety, findings that may suggest possible utility in relieving PTSD-associated anxiety. Treatment of animal models of PTSD with DBS suggests potential human benefit. Additional research and novel treatment options for PTSD are urgently needed. The potential usefulness of brain stimulation in treating PTSD deserves further exploration.

Novakovic, Vladan; Sher, Leo; Lapidus, Kyle A.B.; Mindes, Janet; A.Golier, Julia; Yehuda, Rachel

2011-01-01

219

Deep Brain Stimulation of Caudal Zona Incerta and Subthalamic Nucleus in Patients with Parkinson's Disease: Effects on Voice Intensity  

PubMed Central

Deep brain stimulation of the subthalamic nucleus (STN-DBS) in patients with Parkinson's disease (PD) affects speech inconsistently. Recently, stimulation of the caudal zona incerta (cZi-DBS) has shown superior motor outcomes for PD patients, but effects on speech have not been systematically investigated. The aim of this study was to compare the effects of cZi-DBS and STN-DBS on voice intensity in PD patients. Mean intensity during reading and intensity decay during rapid syllable repetition were measured for STN-DBS and cZi-DBS patients (eight patients per group), before- and 12 months after-surgery on- and off-stimulation. For mean intensity, there were small significant differences on- versus off-stimulation in each group: 74.2 (2.0)?dB contra 72.1 (2.2)?dB (P = .002) for STN-DBS, and 71.6 (4.1)?dB contra 72.8 (3.4)?dB (P = .03) for cZi-DBS, with significant interaction (P < .001). Intensity decay showed no significant changes. The subtle differences found for mean intensity suggest that STN-DBS and cZi-DBS may influence voice intensity differently.

Lundgren, Sofie; Saeys, Thomas; Karlsson, Fredrik; Olofsson, Katarina; Blomstedt, Patric; Linder, Jan; Nordh, Erik; Zafar, Hamayun; van Doorn, Jan

2011-01-01

220

Post-operative assessment in Deep Brain Stimulation based on multimodal images: registration workflow and validation  

NASA Astrophysics Data System (ADS)

Object Movement disorders in Parkinson disease patients may require functional surgery, when medical therapy isn't effective. In Deep Brain Stimulation (DBS) electrodes are implanted within the brain to stimulate deep structures such as SubThalamic Nucleus (STN). This paper describes successive steps for constructing a digital Atlas gathering patient's location of electrodes and contacts for post operative assessment. Materials and Method 12 patients who had undergone bilateral STN DBS have participated to the study. Contacts on post-operative CT scans were automatically localized, based on black artefacts. For each patient, post operative CT images were rigidly registered to pre operative MR images. Then, pre operative MR images were registered to a MR template (super-resolution Collin27 average MRI template). This last registration was the combination of global affine, local affine and local non linear registrations, respectively. Four different studies were performed in order to validate the MR patient to template registration process, based on anatomical landmarks and clinical scores (i.e., Unified Parkinson's disease rating Scale). Visualisation software was developed for displaying into the template images the stimulated contacts represented as cylinders with a colour code related to the improvement of the UPDRS. Results The automatic contact localization algorithm was successful for all the patients. Validation studies for the registration process gave a placement error of 1.4 +/- 0.2 mm and coherence with UPDRS scores. Conclusion The developed visualization tool allows post-operative assessment for previous interventions. Correlation with additional clinical scores will certainly permit to learn more about DBS and to better understand clinical side-effects.

Lalys, Florent; Haegelen, Claire; Abadie, Alexandre; Jannin, Pierre

2009-02-01

221

Suppression of axonal conduction by sinusoidal stimulation in rat hippocampus in vitro  

NASA Astrophysics Data System (ADS)

Deep brain stimulation (DBS), also known as high frequency stimulation (HFS), is a well-established therapy for Parkinson's disease and essential tremor, and shows promise for the therapeutic control of epilepsy. However, the direct effect of DBS on neural elements close to the stimulating electrode remains an important unanswered question. Computational studies have suggested that HFS has a dual effect on neural elements inhibiting cell bodies, while exciting axons. Prior experiments have shown that sinusoidal HFS (50 Hz) can suppress synaptic and non-synaptic cellular activity in several in vitro epilepsy models, in all layers of the hippocampus. However, the effects of HFS on axons near the electrode are still unclear. In the present study, we tested the hypothesis that HFS suppresses axonal conduction in vitro. Sinusoidal HFS was applied to the alvear axon field of transverse rat hippocampal slices. The results show that HFS suppresses the alvear compound action potential (CAP) as well as the CA1 antidromic evoked potential (AEP). Complete suppression was observed as a 100% reduction in the amplitude of the evoked field potential for the duration of the stimulus. Evoked potential width and latency were not significantly affected by sinusoidal HFS. Suppression was dependent on HFS amplitude and frequency, but independent of stimulus duration and synaptic transmission. The frequency dependence of sinusoidal HFS is similar to that observed in clinical DBS, with maximal suppression between 50 and 200 Hz. HFS produced not only suppression of axonal conduction but also a correlated rise in extracellular potassium. These data provide new insights into the effects of HFS on neuronal elements, and show that HFS can block axonal activity through non-synaptic mechanisms.

Jensen, A. L.; Durand, D. M.

2007-06-01

222

[Prerequisites for pacemaker electrodes for individual programming of a low stimulation impulse (comparison of an Elgiloy and a steroid-dependent pacemaker electrode)].  

PubMed

The individual programming of cardiac pacemakers to pulse amplitudes of 2.5 volts and less reduces unnecessary energy consumption by the pacing impulse. In order not to impair the safety margin, electrodes must reveal a low chronic pacing threshold associated with a small standard deviation. For 3 months after implantation we investigated these conditions in 10 patients with a steroid-eluting lead and in 10 patients with a conventional elgiloy lead. During the study period patients with a steroid-eluting lead had a significantly lower pacing threshold. Twelve weeks after implantation all steroid-patients had 0.8 volts pacing threshold at 0.5 ms pulse width. In contrast to the conventional lead the steroid-eluting lead had a significantly lower impedance. Since voltage enters squared into the energy consumption formula, patients with a steroid-eluting lead needed significantly less energy for an effective stimulation of the myocardium 4 and 12 weeks after implantation. R-wave amplitude was not different in both groups. Our investigation demonstrates that immediately after implantation all patients with a steroid-eluting lead can be programmed at 2.5 volts pulse voltage or individually even lower. The saved energy results either in an extended pulse generator longevity or allows the implantation of a smaller pulse generator with a reduced battery capacity. PMID:2378158

Schuchert, A; Kuck, K H; Bleifeld, W

1990-06-01

223

Validation of the Use of Dried Blood Spot (DBS) Method to Assess Vitamin A Status.  

PubMed

Background: Vitamin A deficiency is an important dietary deficiency in the world. Thus, the ne¬cessity of screening for deficient populations is obvious. This paper introduces a fast, cheap and relatively reliable method called "dried blood spot" (DBS) method in screening the deficient populations. The validity of this method for retinol measurement was investigated. Method: The "precision" and "agreement" criteria of the DBS method were assessed. The preci¬sion was calculated and compared with those of plasma using F-test. The agreement was eva¬luated using Bland-Altman plot. Results: The imprecision of retinol measurements in dried spots was not significantly different from those of the control (plasma). A good correlation coefficient (r2=0.78) was obtained for dried spots' retinol measurements versus plasma's retinol analysis (P < 0.01). Paired t-test showed no significant difference between the DBS and retinol methods on a group level. Imprecision of DBS measurement was acceptable, compared to that of the plasma method. The difference be¬tween these two methods was not statistically significant on a group level. Conclusion: Application of DBS standard samples, in which a part of the plasma was replaced with the artificial plasma, was shown to be a reliable calibration mean for retinol measurements in DBS samples. Retinol in dried spots was stable for 90 days. Overall, the DBS method provided a precise measurement of retinol, showing results that were comparable with the measurement of retinol in plasma. PMID:24688932

Fallah, Elham; Peighambardoust, Seyed Hadi

2012-01-01

224

Using reciprocal derivative chronopotentiometry as a technique to determine safe charge injection limits of electrodes used for neural stimulation.  

PubMed

We used reciprocal derivative chronopotentiometry (RDC) with platinum electrodes of 50 microm diameter in 0.15 M phosphate buffered saline solution to identify the various electrochemical processes occurring at the electrode during biphasic current pulsing. RDC allowed to determine the limits of water hydrolysis based on the specific (dt/dE)-E data representation employed in this technique resulting in curves similar to the voltammetric i-E response. Current stimulation was performed by either varying the pulse amplitude or pulse width. We found that the limits for H(2) and O(2) evolution for constant-amplitude pulses lied at 0.51 mC/cm(2) and 0.67 mC/cm(2), respectively, while for constant-width pulses they occurred at slightly lower values of 0.49 mC/cm(2) and 0.61 mC/cm(2), respectively. We could also extract values for the anodic and cathodic overvoltages associated with gas evolution. The cathodic overvoltage for H(2) evolution was 1.43 V for both constant-amplitude and constant-width pulses, while the anodic overpotentials for O(2) evolution were 2.45 V in the first and 2.24 V in the latter case. These values are clearly larger than the gas evolution limits generally found with steady-state voltammetry. PMID:21095991

Musa, Silke; Prodanov, Dimiter; Loo, Josine; Eberle, Wolfgang; Bartic, Carmen; Nuttin, Bart; Borghs, Gustaaf

2010-01-01

225

A Low-Power Blocking-Capacitor-Free Charge-Balanced Electrode-Stimulator Chip With Less Than 6 nA DC Error for 1mA Full-Scale Stimulation  

Microsoft Academic Search

Large dc blocking capacitors are a bottleneck in reducing the size and cost of neural implants. We describe an electrode-stimulator chip that removes the need for large dc blocking capacitors in neural implants by achieving precise charge-balanced stimulation with <6 nA of dc error. For cochlear implant patients, this is well below the industry's safety limit of 25 nA. Charge

Ji-Jon Sit; Rahul Sarpeshkar

2007-01-01

226

Adaptive control of deep brain stimulator for essential tremor: entropy-based tremor prediction using surface-EMG.  

PubMed

Entropy, as a measure of randomness in time-varying signals, is widely used in areas such as thermodynamics, statistical mechanics and information theory. This paper investigates the use of two commonly employed entropy measures, namely Wavelet Entropy and Approximate Entropy, as a predictor of tremor reappearance in Essential Tremor patients; the predictor input is a raw surface-electromyographic (sEMG) signal measured from tremor affected muscles of patients implanted with a Deep Brain Stimulator (DBS). A combination of both types of entropy measure is shown to successfully predict the occurrence of tremor few seconds before its visual manifestation. This result can potentially lead to a novel sEMG-based adaptive on-off DBS controller that can be added on to existing open-loop DBS systems with minimal changes; an adaptive DBS system provides stimulation only when needed thereby reducing the risk of brain over stimulation, delaying DBS intolerance and prolonging DBS battery life. PMID:22256125

Basu, Ishita; Tuninetti, Daniela; Graupe, Daniel; Slavin, Konstantin V

2011-01-01

227

Pont de dolor: a dual laminotomy technique for placing and securing an electrode in the epidural space and comments about anatomic variation that may complicate spinal cord stimulator electrode placement.  

PubMed

The objective of this report is to describe a surgical technique used successfully when a flat or paddle type spinal cord stimulator electrode cannot be properly positioned via a single laminotomy. Different and innovative surgical techniques useful in placement of spinal cord stimulators and analgesic infusion pump systems have not been well described. The prevalence of anatomic surgical abnormalities or variations that might present barriers to implantation of these devices is unknown but may be as high as 18% for revisions. A dual laminotomy technique can be useful and successful in positioning a flat spinal cord stimulator electrode that cannot be properly positioned via a single laminotomy approach. We report two patients who have been treated successfully with a dual laminotomy technique. PMID:22150966

Ball, Perry A; Fanciullo, Gilbert J

2003-04-01

228

Spinal Anesthesia and Minimal Invasive Laminotomy for Paddle Electrode Placement in Spinal Cord Stimulation: Technical Report and Clinical Results at Long-Term Followup  

PubMed Central

Object. We arranged a mini-invasive surgical approach for implantation of paddle electrodes for SCS under spinal anesthesia obtaining the best paddle electrode placement and minimizing patients' discomfort. We describe our technique supported by neurophysiological intraoperative monitoring and clinical results. Methods. 16 patients, affected by neuropathic pain underwent the implantation of paddle electrodes for spinal cord stimulation in lateral decubitus under spinal anesthesia. The paddle was introduced after flavectomy and each patient confirmed the correct distribution of paresthesias induced by intraoperative test stimulation. VAS and patients' satisfaction rate were recorded during the followup and compared to preoperative values. Results. No patients reported discomfort during the procedure. In all cases, paresthesias coverage of the total painful region was achieved, allowing the best final electrode positioning. At the last followup (mean 36.7 months), 87.5% of the implanted patients had a good rate of satisfaction with a mean VAS score improvement of 70.5%. Conclusions. Spinal cord stimulation under spinal anesthesia allows an optimal positioning of the paddle electrodes without any discomfort for patients or neurosurgeons. The best intraoperative positioning allows a better postoperative control of pain, avoiding the risk of blind placements of the paddle or further surgery for their replacement.

Sarubbo, S.; Latini, F.; Tugnoli, V.; Quatrale, R.; Granieri, E.; Cavallo, M. A.

2012-01-01

229

Effectiveness of finger-equipped electrode (FEE)-triggered electrical stimulation improving chronic stroke patients with severe hemiplegia  

PubMed Central

Background: Electric stimulation (ES) has been recognized as an effective method to improve motor function to paralysed patients with stroke. It is important for ES to synchronize with voluntary movement. To enhance this co-ordination, the finger-equipped electrode (FEE) was developed. The purpose of this study was to evaluate FEE in improving motor function of upper extremities (UEs) in patients with chronic stroke. Methods and subjects: The study participants included four patients with chronic stroke who received FEE electronic stimulation (FEE-ES) plus passive and active training and three control patients who underwent training without FEE-ES. The patients were treated five times weekly for 4 weeks. UE motor function was evaluated before and after treatment using Fugl-Meyer Assessment (FMA) and Brunnstrom recovery staging. Results: The mean age of patients in each group was 60-years and there was a mean of 49 months since the onset of symptoms. All patients had severe UE weakness. The patients receiving FEE-ES had greater improvement in UE function than control patients (total, proximal and distal FMA, p?

Inobe, Jun-ichi; Kato, Takashi

2013-01-01

230

Deep brain stimulation for Tourette syndrome.  

PubMed

Gilles de la Tourette syndrome is a movement disorder characterized by repetitive stereotyped motor and phonic movements with varying degrees of psychiatric comorbidity. Deep brain stimulation (DBS) has emerged as a novel therapeutic intervention for patients with refractory Tourette syndrome. Since 1999, more than 100 patients have undergone DBS at various targets within the corticostriatothalamocortical network thought to be implicated in the underlying pathophysiology of Tourette syndrome. Future multicenter clinical trials and the use of a centralized online database to compare the results are necessary to determine the efficacy of DBS for Tourette syndrome. PMID:24262904

Kim, Won; Pouratian, Nader

2014-01-01

231

Patient-Specific Model-Based Investigation of Speech Intelligibility and Movement during Deep Brain Stimulation  

Microsoft Academic Search

Background\\/Aims: Deep brain stimulation (DBS) is widely used to treat motor symptoms in patients with advanced Parkinson’s disease. The aim of this study was to investigate the anatomical aspects of the electric field in relation to effects on speech and movement during DBS in the subthalamic nucleus. Methods: Patient-specific finite element models of DBS were developed for simulation of the

Mattias Ĺström; Elina Tripoliti; Marwan I. Hariz; Ludvic U. Zrinzo; Irene Martinez-Torres; Patricia Limousin; Karin Wĺrdell

2010-01-01

232

Update of the EBF recommendation for the use of DBS in regulated bioanalysis integrating the conclusions from the EBF DBS-microsampling consortium.  

PubMed

The European Bioanalysis Forum dried blood spots/microsampling consortium is reporting back from the experiments they performed on further documenting the potential hurdles of the DBS technology. Their experiments focused on the impact of hematocrit changes, IS addition, spot homogeneity, aging of spots and stability of fresh blood and cards. Results from these experiments demonstrate that the issues of DBS in regulated bioanalysis are real and that the technology will need additional improvements to be ready for use as a general tool for regulated bioanalysis. In addition, results on fresh blood and card stability were shared at international meetings and will be reported at a later date. PMID:23829466

Timmerman, Philip; White, Steve; Cobb, Zoe; de Vries, Ronald; Thomas, Elizabeth; van Baar, Ben

2013-09-01

233

Study on the Nonisothermal Melt Crystallization Kinetics of DBS\\/PBT Blends  

Microsoft Academic Search

The modified Avrami, Mo, and Kissinger models were applied to investigate the nonisothermal melt crystallization process of dibenzylidene sorbitol (DBS)\\/poly(butylene terephthalate) (PBT) blends by differential scanning colorimetry (DSC) measurements. The modified Avrami model can describe the nonisothermal melt crystallization processes of DBS\\/PBT blends fairly well. The cooling rates and the blend composition affect the crystallization of the blends according to

Guijuan Li; Xingwen Mu; Dandan Wang; Shourui Fan

2010-01-01

234

High frequency stimulation abolishes thalamic network oscillations: an electrophysiological and computational analysis  

NASA Astrophysics Data System (ADS)

Deep brain stimulation (DBS) of the thalamus has been demonstrated to be effective for the treatment of epilepsy. To investigate the mechanism of action of thalamic DBS, we examined the effects of high frequency stimulation (HFS) on spindle oscillations in thalamic brain slices from ferrets. We recorded intracellular and extracellular electrophysiological activity in the nucleus reticularis thalami (nRt) and in thalamocortical relay (TC) neurons in the lateral geniculate nucleus, stimulated the slice using a concentric bipolar electrode, and recorded the level of glutamate within the slice. HFS (100 Hz) of TC neurons generated excitatory post-synaptic potentials, increased the number of action potentials in both TC and nRt neurons, reduced the input resistance, increased the extracellular glutamate concentration, and abolished spindle wave oscillations. HFS of the nRt also suppressed spindle oscillations. In both locations, HFS was associated with significant and persistent elevation in extracellular glutamate levels and suppressed spindle oscillations for many seconds after the cessation of stimulation. We simulated HFS within a computational model of the thalamic network, and HFS also disrupted spindle wave activity, but the suppression of spindle activity was short-lived. Simulated HFS disrupted spindle activity for prolonged periods of time only after glutamate release and glutamate-mediated activation of a hyperpolarization-activated current (Ih) was incorporated into the model. Our results suggest that the mechanism of action of thalamic DBS as used in epilepsy may involve the prolonged release of glutamate, which in turn modulates specific ion channels such as Ih, decreases neuronal input resistance, and abolishes thalamic network oscillatory activity.

Lee, Kendall H.; Hitti, Frederick L.; Chang, Su-Youne; Lee, Dongchul C.; Roberts, David W.; McIntyre, Cameron C.; Leiter, James C.

2011-08-01

235

Responses of rabbit retinal ganglion cells to electrical stimulation with an epiretinal electrode  

NASA Astrophysics Data System (ADS)

Rational selection of electrical stimulus parameters for an electronic retinal prosthesis requires knowledge of the electrophysiological responses of retinal neurons to electrical stimuli. In this study, we examined the effects of cathodal and anodal current pulses on the extracellularly recorded responses of OFF and ON rabbit retinal ganglion cells (RGCs) in an in vitro preparation. Current pulses (1 msec duration), delivered by a 125 µm electrode placed on the inner retinal surface within the receptive field of a RGC, produced both short-latency (<=5 msec) and long-latency (8-60 msec) responses. The long-latency responses, but not the short-latency responses, were abolished upon application of the glutamate receptor antagonists CNQX and NBQX, thus indicating that the long-latency responses of RGCs are due to activation of presynaptic neurons in the retina. The latency of the long-latency response depended upon the polarity of the stimulus. For OFF RGCs, the average latency was 11 msec for a cathodal stimulus and 24 msec for an anodal stimulus. For ON RGCs, the average latency was 25 msec for a cathodal stimulus and 16 msec for an anodal stimulus. The threshold current also depended upon the polarity of the stimulus, at least for OFF RGCs. The average threshold current for evoking a long-latency response in OFF RGCs was 10 µA for a cathodal stimulus and 21 µA for an anodal stimulus. In ON RGCs, the average threshold current was 13 µA for a cathodal stimulus and 15 µA for an anodal stimulus.

Jensen, Ralph J.; Ziv, Ofer R.; Rizzo, Joseph F.

2005-03-01

236

Effective deep brain stimulation suppresses low frequency network oscillations in the basal ganglia by regularizing neural firing patterns  

PubMed Central

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for the motor symptoms of Parkinson’s disease (PD). The effects of DBS depend strongly on stimulation frequency: high frequencies (>90Hz) improve motor symptoms, while low frequencies (<50Hz) are either ineffective or exacerbate symptoms. The neuronal basis for these frequency-dependent effects of DBS is unclear. The effects of different frequencies of STN-DBS on behavior and single-unit neuronal activity in the basal ganglia were studied in the unilateral 6-hydroxydopamine lesioned rat model of PD. Only high frequency DBS reversed motor symptoms and the effectiveness of DBS depended strongly on stimulation frequency in a manner reminiscent of its clinical effects in persons with PD. Quantification of single-unit activity in the globus pallidus externa (GPe) and substantia nigra reticulata (SNr) revealed that high frequency DBS, but not low frequency DBS, reduced pathological low frequency oscillations (~9Hz) and entrained neurons to fire at the stimulation frequency. Similarly, the coherence between simultaneously recorded pairs of neurons within and across GPe and SNr shifted from the pathological low frequency band to the stimulation frequency during high frequency DBS, but not during low frequency DBS. The changes in firing patterns in basal ganglia neurons were not correlated with changes in firing rate. These results indicate that high frequency DBS is more effective than low frequency DBS, not as a result of changes in firing rate, but rather due to its ability to replace pathological low frequency network oscillations with a regularized pattern of neuronal firing.

McConnell, George C.; So, Rosa Q.; Hilliard, Justin D; Lopomo, Paola; Grill, Warren M.

2012-01-01

237

The pedunculopontine tegmental nucleus: from basic neuroscience to neurosurgical applications: arousal from slices to humans: implications for DBS.  

PubMed

One element of the reticular activating system (RAS) is the pedunculopontine nucleus (PPN), which projects to the thalamus to trigger thalamocortical rhythms and the brainstem to modulate muscle tone and locomotion. The PPN is a posterior midbrain site known to induce locomotion in decerebrate animals when activated at 40-60 Hz, and has become a target for DBS in disorders involving gait deficits. We developed a research program using brainstem slices containing the PPN to study the cellular and molecular organization of this region. We showed that PPN neurons preferentially fire at gamma band frequency (30-60 Hz) when maximally activated, accounting for the effects of electrical stimulation. In addition, we developed the P13 midlatency auditory evoked potential, which is generated by PPN outputs, in freely moving rats. This allows the study of PPN cellular and molecular mechanisms in the whole animal. We also study the P50 midlatency auditory evoked potential, which is the human equivalent of the rodent P13 potential, allowing us to study PPN-related processes detected in vitro, confirmed in the whole animal, and tested in humans. Previous findings on the P50 potential in PD suggest that PPN output in this disorder is overactive. This translational research program led to the discovery of a novel mechanism of sleep-wake control based on electrical coupling, pointing the way to a number of new clinical applications in the development of novel stimulants (e.g., modafinil) and anesthetics. In addition, it provides methods for monitoring therapeutic efficacy of DBS in humans and animal models. PMID:20936418

Garcia-Rill, Edgar; Simon, Christen; Smith, Kristen; Kezunovic, Nebosja; Hyde, James

2011-10-01

238

Deep Brain Stimulation for the Treatment of Tremor and Ataxia Associated with Abetalipoproteinemia  

PubMed Central

Background Abetalipoproteinemia is a rare disorder of fat absorption, characterized by vitamin deficiency, acanthocytosis, and neurologic symptoms including ataxia and tremor. Case Report A 41-year-old male with abetalipoproteinemia is presented. He underwent staged bilateral thalamic deep brain stimulation (DBS) for the treatment of his tremors. After DBS, the patient achieved significant improvements in his tremors, ataxia, and quality of life. Discussion Thalamic DBS proved to be both safe and efficacious in the management of ataxia and tremors in a patient with abetalipoproteinemia. This is the first report of DBS in abetalipoproteinemia in the literature.

Mammis, Antonios; Pourfar, Michael; Feigin, Andrew; Mogilner, Alon Y.

2012-01-01

239

Dopamine transporter changes after unilateral deep brain stimulation in progressive Parkinson's disease: a case report  

PubMed Central

Deep brain stimulation (DBS) at the subthalamic nucleus has been approved as an effective treatment for refractory symptoms of Parkinson’s disease (PD). Studies have shown that bilateral DBS surgery in PD patients results in clinical improvement without reducing dopamine transporter function. Here, we report our longitudinal findings in one PD patient, ie, decreases in striatal dopamine transporter binding during one year of follow-up after unilateral DBS at the subthalamic nucleus. Based on this case, we hypothesize that clinical benefit after unilateral DBS may be not directly associated with changes in function at the subthalamic nucleus.

Zhang, Huiwei; Wang, Yuanyuan; Liang, Jinchuan; Forster, Stefan; Wu, Ping; Zhao, Jun; Guan, Yihui; Zuo, Chuantao

2014-01-01

240

Modulating Endogenous Electric Currents in Human Corneal Wounds--A Novel Approach of Bioelectric Stimulation Without Electrodes  

PubMed Central

Purpose To measure electric current in human corneal wounds and test the feasibility of pharmacologically enhancing the current to promote corneal wound healing. Methods Using a noninvasive vibrating probe, corneal electric current was measured before and after wounding of the epithelium of donated postmortem human corneas. The effects of drug aminophylline and chloride-free solution on wound current were also tested. Results Unwounded cornea had small outward currents (0.07 ?A/cm2). Wounding increased the current more than 5 fold (0.41 ?A/cm2). Monitoring the wound current over time showed that it seemed to be actively regulated and maintained above normal unwounded levels for at least 6 hours. The time course was similar to that previously measured in rat cornea. Drug treatment or chloride-free solution more than doubled the size of wound currents. Conclusions Electric current at human corneal wounds can be significantly increased with aminophylline or chloride-free solution. Because corneal wound current directly correlates with wound healing rate, our results suggest a role for chloride-free and/or aminophylline eyedrops to enhance healing of damaged cornea in patients with reduced wound healing such as the elderly or diabetic patient. This novel approach offers bioelectric stimulation without electrodes and can be readily tested in patients.

Reid, Brian; Graue-Hernandez, Enrique O.; Mannis, Mark J.; Zhao, Min

2011-01-01

241

Ethical considerations in deep brain stimulation for psychiatric illness.  

PubMed

Deep brain stimulation (DBS) is an efficacious surgical treatment for many conditions, including obsessive-compulsive disorder and treatment-resistant depression. DBS provides a unique opportunity to not only ameliorate disease but also to study mood, cognition, and behavioral effects in the brain. However, there are many ethical questions that must be fully addressed in designing clinical research trials. It is crucial to maintain sound ethical boundaries in this new era so as to permit the proper testing of the potential therapeutic role DBS may play in ameliorating these devastating and frequently treatment-refractory psychiatric disorders. In this review, we focus on the selection of patients for study, informed consent, clinical trial design, DBS in the pediatric population, concerns about intentionally or inadvertently altering an individual's personal identity, potential use of DBS for brain enhancement, direct modification of behavior through neuromodulation, and resource allocation. PMID:24055023

Grant, Ryan A; Halpern, Casey H; Baltuch, Gordon H; O'Reardon, John P; Caplan, Arthur

2014-01-01

242

Magnetic resonance imaging safety of deep brain stimulator devices.  

PubMed

Magnetic resonance imaging (MRI) has become the standard of care for the evaluation of different neurological disorders of the brain and spinal cord due to its multiplanar capabilities and excellent soft tissue resolution. With the large and increasing population of patients with implanted deep brain stimulation (DBS) devices, a significant proportion of these patients with chronic neurological diseases require evaluation of their primary neurological disease processes by MRI. The presence of an implanted DBS device in a magnetic resonance environment presents potential hazards. These include the potential for induction of electrical currents or heating in DBS devices, which can result in neurological tissue injury, magnetic field-induced device migration, or disruption of the operational aspects of the devices. In this chapter, we review the basic physics of potential interactions of the MRI environment with implanted DBS devices, summarize results from phantom studies and clinical series, and discuss present recommendations for safe MRI in patients with implanted DBS devices. PMID:24112886

Oluigbo, Chima O; Rezai, Ali R

2013-01-01

243

Focused Current Density Imaging Using Internal Electrode in Magnetic Resonance Electrical Impedance Tomography (MREIT).  

PubMed

Magnetic resonance electrical impedance tomography (MREIT) is an imaging modality capable of visualizing cross-sectional current density and/or conductivity distributions inside an electrically conducting object. It uses an MRI scanner to measure one component of the magnetic flux density induced by an externally injected current through a pair of surface electrodes. For the cases of deep brain stimulation (DBS), electroporation, and radio frequency (RF) ablation, internal electrodes can be used to improve the quality of the MREIT images. In this paper, we propose a new MREIT imaging method using internal electrodes to visualize a current density distribution within a local region around them. To evaluate its performance, we conducted and analyzed a series of numerical simulations and phantom imaging experiments. We compared the reconstructed current density images using the internal electrodes with the obtained using only the external electrodes. We found that the proposed method using the internal electrodes stably determines the current density in the focused region with better accuracy. PMID:24956612

Jeong, Woo Chul; Sajib, Saurav; Kim, Hyung Joong; Kwon, Oh In

2014-07-01

244

Prognostic Factors of Subthalamic Stimulation in Parkinson’s Disease: A Comparative Study between Short and Long-Term Effects  

Microsoft Academic Search

Background\\/Aims: Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) has been shown to have long-term benefits in Parkinson’s disease (PD). Through analyzing different variables, this study identified prognostic factors for the short- and long-term effects of STN-DBS. Methods: Thirty-six PD patients underwent bilateral STN-DBS. Clinical evaluations were performed 1 month before and 3 months after surgery, with additional follow-up examinations for

Sheng-Tzung Tsai; Sheng-Huang Lin; Yu-Cheng Chou; Yan-Hong Pan; Hsiang-Yi Hung; Chi-Wei Li; Shinn-Zong Lin; Shin-Yuan Chen

2009-01-01

245

Deep brain stimulation for pain.  

PubMed

Deep brain stimulation (DBS) is a neurosurgical intervention whose efficacy, safety, and utility have been shown in the treatment of movement disorders. For the treatment of chronic pain refractory to medical therapies, many prospective case series have been reported, but few have published findings from patients treated during the past decade using current standards of neuroimaging and stimulator technology. We summarize the history, science, selection, assessment, surgery, and personal clinical experience of DBS of the ventral posterior thalamus, periventricular/periaqueductal gray matter, and, latterly, the rostral anterior cingulate cortex (Cg24) in 100 patients treated now at two centers (John Radcliffe Hospital, Oxford, UK, and Hospital de Săo Joăo, Porto, Portugal) over 12 years. Several experienced centers continue DBS for chronic pain with success in selected patients, in particular those with pain after amputation, brachial plexus injury, stroke, and cephalalgias including anesthesia dolorosa. Other successes include pain after multiple sclerosis and spine injury. Somatotopic coverage during awake surgery is important in our technique, with cingulate DBS considered for whole-body pain or after unsuccessful DBS of other targets. Findings discussed from neuroimaging modalities, invasive neurophysiological insights from local field potential recording, and autonomic assessments may translate into improved patient selection and enhanced efficacy, encouraging larger clinical trials. PMID:24112902

Pereira, Erlick A C; Green, Alexander L; Aziz, Tipu Z

2013-01-01

246

Effects of subthalamic nucleus stimulation and medication on resting and postural tremor in Parkinson's disease  

Microsoft Academic Search

Summary Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and antiparkinsonian medication have proved to be effective treatments for tremor in Parkinson's disease. To date it is not known how and to what extent STN DBS alone and in combination with antiparkinsonian medication alters the pathophysiology of resting and postural tremor in idiopathic Parkinson's disease. The purpose of this

Molly M. Sturman; David E. Vaillancourt; Leo Verhagen Metman; Roy A. E. Bakay; Daniel M. Corcos

2004-01-01

247

[Deep brain stimulation for psychiatric disorders: historical basis].  

PubMed

Deep brain stimulation (DBS), which is already established as an effective treatment for movement disorders, such as Parkinson's disease, is increasingly being considered as a therapy option for mental diseases. Due to the increasing number of successful applications of DBS for otherwise therapy-resistant psychiatric diseases, DBS is becoming more and more of interest in fields of fundamental research as well as clinical care. However, the stimulation system is a medical product which has to be neurosurgically implanted and this fact is often used to draw certain analogies to earlier psychosurgical approaches in the era of Freeman. But, looking at the historical development of DBS, as is the aim of the present systematic and literature-based overview, it becomes obvious that DBS did not arise exclusively from the inglorious period of psychosurgery. In fact, two partly in parallel evolving lines of medical progress have contributed to the development of DBS as it is applied today. One of these lines is the use of lesional neurosurgical procedures, such as incision of capsules and cingulotomy, which in contrast to psychosurgical interventions in the era of Freeman, is aimed at subcortical structures and provides important basic knowledge for the choice of target points. In addition DBS is rooted in the application of an electrical charge with the goal to stimulate neuronal networks. PMID:21761184

Huys, D; Möller, M; Kim, E-H; Hardenacke, K; Huff, W; Klosterkötter, J; Timmermann, L; Woopen, C; Kuhn, J

2012-09-01

248

Effects of subthalamic nucleus deep brain stimulation and L-DOPA on blinking in Parkinson's disease.  

PubMed

In this study we asked whether subthalamic nucleus deep brain stimulation (STN-DBS) alone, or in combination with l-dopa, modifies voluntary, spontaneous and reflex blinking in patients with Parkinson's disease (PD). Sixteen PD patients who underwent STN-DBS were studied in four experimental conditions: without STN-DBS and without l-dopa, STN-DBS alone, l-dopa alone and STN-DBS plus l-dopa. The results were compared with those obtained in 15 healthy controls. Voluntary blinking was assessed by asking participants to blink as fast as possible; spontaneous blinking was recorded during two 60s rest periods; reflex blinking was evoked by electrical stimulation of the supraorbital nerve. Blinking were recorded and analysed with the SMART motion system. STN-DBS increased the peak velocity and amplitude for both the closing and opening voluntary blink phases, but prolonged the inter-phase pause duration. l-dopa had no effects on voluntary blinking but reversed the increased inter-phase pause duration seen during STN-DBS. Spontaneous blink rate increased after either STN-DBS or l-dopa. Reflex blinking kinematics were not modified by STN-DBS or l-dopa. The STN-DBS effects on voluntary blinking kinematics and spontaneous blinking rate may occur as results of changes of cortico-basal ganglia activity. The prolonged pause duration of voluntary blinking indicates that STN-DBS has detrimental effects on the cranial region. These results also shed light on the pathophysiology of eyelids opening apraxia following STN-DBS. PMID:22366535

Bologna, Matteo; Fasano, Alfonso; Modugno, Nicola; Fabbrini, Giovanni; Berardelli, Alfredo

2012-05-01

249

Model-based analysis and design of nerve cuff electrodes for restoring bladder function by selective stimulation of the pudendal nerve  

NASA Astrophysics Data System (ADS)

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 restoration of bladder function.

Kent, Alexander R.; Grill, Warren M.

2013-06-01

250

Model-based analysis and design of nerve cuff electrodes for restoring bladder function by selective stimulation of the pudendal nerve  

PubMed Central

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 10 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 restoration of bladder function.

Kent, Alexander R; Grill, Warren M

2013-01-01

251

The control of neural cell-to-cell interactions through non-contact electrical field stimulation using graphene electrodes  

Microsoft Academic Search

Electric field stimulation has become one of the most promising therapies for a variety of neurological diseases. However, the safety and effectiveness of the stimulator are critical in determining the outcome. Because there are few safe and effective in vivo and\\/or in vitro stimulator devices, we demonstrate a method that allows for non-contact electric field stimulation with a specific strength

Chaejeong Heo; Jeongwan Yoo; Siyoung Lee; Areum Jo; Susie Jung; Hyosun Yoo; Young Hee Lee; Minah Suh

2011-01-01

252

Uncovering the mechanism(s) of deep brain stimulation  

NASA Astrophysics Data System (ADS)

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.

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

2005-01-01

253

Single-cell stimulation and electroporation using a novel 0.18 µ CMOS chip with subcellular-sized electrodes  

Microsoft Academic Search

In drug screening and pharmaceutical research, high-throughput systems that are able to perform single-cell measurements are highly desired. Micro-electrode arrays try to answer this need but still suffer from significant drawbacks such as a small amount of electrodes and the inability to address single cells. Here, we present a novel multi-transistor array chip with 16,384 subcellular-sized electrodes based on 0.18

Dries Braeken; Roeland Huys; Josine Loo; Carmen Bartic; Gustaaf Borghs; Geert Callewaert; Wolfgang Eberle

2010-01-01

254

Electrical Stimulation with Pt Electrodes: II-Estimation of Maximum Surface Redox (Theoretical Non-Gassing) Limits  

Microsoft Academic Search

The maximum, biphasically applied charge which can be injected without electrolyzing water has been determined for Pt electrodes in simulated cerebral spinal fluid at 37°C. Electrolysis of water would lead to gas bubble formation, which is thought to be harmful. The experimental method involved the use of electrical transients. With lead (anodic faist) electrodes, the theoretical non-gassing limit is 300

S. B. BRUMMERANDM; M. J. Turner

1977-01-01

255

Time and Frequency-Dependent Modulation of Local Field Potential Synchronization by Deep Brain Stimulation  

PubMed Central

High-frequency electrical stimulation of specific brain structures, known as deep brain stimulation (DBS), is an effective treatment for movement disorders, but mechanisms of action remain unclear. We examined the time-dependent effects of DBS applied to the entopeduncular nucleus (EP), the rat homolog of the internal globus pallidus, a target used for treatment of both dystonia and Parkinson’s disease (PD). We performed simultaneous multi-site local field potential (LFP) recordings in urethane-anesthetized rats to assess the effects of high-frequency (HF, 130 Hz; clinically effective), low-frequency (LF, 15 Hz; ineffective) and sham DBS delivered to EP. LFP activity was recorded from dorsal striatum (STR), ventroanterior thalamus (VA), primary motor cortex (M1), and the stimulation site in EP. Spontaneous and acute stimulation-induced LFP oscillation power and functional connectivity were assessed at baseline, and after 30, 60, and 90 minutes of stimulation. HF EP DBS produced widespread alterations in spontaneous and stimulus-induced LFP oscillations, with some effects similar across regions and others occurring in a region- and frequency band-specific manner. Many of these changes evolved over time. HF EP DBS produced an initial transient reduction in power in the low beta band in M1 and STR; however, phase synchronization between these regions in the low beta band was markedly suppressed at all time points. DBS also enhanced low gamma synchronization throughout the circuit. With sustained stimulation, there were significant reductions in low beta synchronization between M1-VA and STR-VA, and increases in power within regions in the faster frequency bands. HF DBS also suppressed the ability of acute EP stimulation to induce beta oscillations in all regions along the circuit. This dynamic pattern of synchronizing and desynchronizing effects of EP DBS suggests a complex modulation of activity along cortico-BG-thalamic circuits underlying the therapeutic effects of GPi DBS for conditions such as PD and dystonia.

McCracken, Clinton B.; Kiss, Zelma H. T.

2014-01-01

256

Centro-median stimulation yields additional seizure frequency and attention improvement in patients previously submitted to callosotomy  

Microsoft Academic Search

RationaleDeep brain stimulation (DBS) has been increasingly used in the treatment of refractory epilepsy over the last decade. We report on the outcome after thalamic centro-median (CM) DBS in patients with generalized epilepsy who had been previously treated with extended callosal section.

Arthur Cukiert; Jose Augusto Burattini; Cristine Mella Cukiert; Meire Argentoni-Baldochi; Carla Baise-Zung; Cássio Roberto Forster; Valeria Antakli Mello

2009-01-01

257

Site of cochlear stimulation and its effect on electrically evoked compound action potentials using the MED-EL standard electrode array  

PubMed Central

Background The standard electrode array for the MED-EL MAESTRO cochlear implant system is 31 mm in length which allows an insertion angle of approximately 720°. When fully inserted, this long electrode array is capable of stimulating the most apical region of the cochlea. No investigation has explored Electrically Evoked Compound Action Potential (ECAP) recordings in this region with a large number of subjects using a commercially available cochlear implant system. The aim of this study is to determine if certain properties of ECAP recordings vary, depending on the stimulation site in the cochlea. Methods Recordings of auditory nerve responses were conducted in 67 subjects to demonstrate the feasibility of ECAP recordings using the Auditory Nerve Response Telemetry (ART™) feature of the MED-EL MAESTRO system software. These recordings were then analyzed based on the site of cochlear stimulation defined as basal, middle and apical to determine if the amplitude, threshold and slope of the amplitude growth function and the refractory time differs depending on the region of stimulation. Results Findings show significant differences in the ECAP recordings depending on the stimulation site. Comparing the apical with the basal region, on average higher amplitudes, lower thresholds and steeper slopes of the amplitude growth function have been observed. The refractory time shows an overall dependence on cochlear region; however post-hoc tests showed no significant effect between individual regions. Conclusions Obtaining ECAP recordings is also possible in the most apical region of the cochlea. However, differences can be observed depending on the region of the cochlea stimulated. Specifically, significant higher ECAP amplitude, lower thresholds and steeper amplitude growth function slopes have been observed in the apical region. These differences could be explained by the location of the stimulating electrode with respect to the neural tissue in the cochlea, a higher density, or an increased neural survival rate of neural tissue in the apex. Trial registration The Clinical Investigation has the Competent Authority registration number DE/CA126/AP4/3332/18/05.

2009-01-01

258

A study of a contoured beam antenna for future Japanese DBS  

Microsoft Academic Search

A study of contoured beam for future Japanese direct broadcasting satellites (DBS) with pattern analysis and test results for the full-scale bread board model are presented. The design of a contoured beam antenna consisting of a single offset shaped reflector and a feed horn is described as a means to optimize the radiating power for the territory. The antenna design

Kazuyoshi Shogen; Hayato Nishida; Noboru Toyama; Tomoki Obuchi; Yoshihide Miyata; Satoshi Miyatani

1992-01-01

259

EFFECT OF MOLECULAR ARCHITECTURE ON DBS-INDUCED BLOCK COPOLYMER GELS: A RHEOLOGICAL STUDY  

EPA Science Inventory

Dibenzylidene sorbitol (DBS) is capable of gelling a variety of organic solvents and polymeric materials by forming a rigid, 3-D hydrogen-bonded network. In this work, two poly(siloxane)/poly(propylene oxide) segmented copolymers of equal composition and molecular weight, but di...

260

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

PubMed

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

Hedera, Peter

2014-05-01

261

Neuropsychiatric deep brain stimulation for translational neuroimaging.  

PubMed

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 comparing these to neuroimaging results. The present study thus improves comparability between functional, structural and molecular data in standard stereotactic space gained in neuroimaging studies with surgical targets for DBS, which is among other possible implications of crucial importance for the definition of new targets for effective DBS. PMID:23631986

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

2013-10-01

262

Stimulation of contacts in ventral but not dorsal subthalamic nucleus normalizes response switching in Parkinson's disease  

PubMed Central

Switching between responses is a key executive function known to rely on the frontal cortex and the basal ganglia. Here we aimed to establish with greater anatomical specificity whether such switching could be mediated via different possible frontal–basal-ganglia circuits. Accordingly, we stimulated dorsal vs. ventral contacts of electrodes in the subthalamic nucleus (STN) in Parkinson's patients during switching performance, and also studied matched controls. The patients underwent three sessions: once with bilateral dorsal contact stimulation, once with bilateral ventral contact stimulation, and once Off stimulation. Patients Off stimulation showed abnormal patterns of switching, and stimulation of the ventral contacts but not the dorsal contacts normalized the pattern of behavior relative to controls. This provides some of the first evidence in humans that stimulation of dorsal vs. ventral STN DBS contacts has differential effects on executive function. As response switching is an executive function known to rely on prefrontal cortex, these results suggest that ventral contact stimulation affected an executive/associative cortico-basal ganglia circuit.

Greenhouse, Ian; Gould, Sherrie; Houser, Melissa; Aron, Adam R.

2014-01-01

263

Portable microstimulator for chronic deep brain stimulation in freely moving rats.  

PubMed

In the last decades, deep brain stimulation (DBS) has been widely used as a functional surgical strategy for the treatment of a variety of neurological and psychiatric disorders, including Parkinson's disease (PD), dystonia, epilepsy, depression or obsessive-compulsive disorder. While the therapeutic benefits of DBS are now recognized, experimental data on its mechanisms and impact at long term remain poor. This is mainly due to the lack of a microstimulation system adapted for chronic DBS in small laboratory animals. In this context, we have developed a microstimulator for DBS adapted to rat. This device, which has a size and weight compatible for use in freely moving rat, can be clipped to a support fixed on the animal's head. This easy "removal" property is crucial because it enables removing or even switching the microstimulator during the experiments without having to anaesthetize or to operate the animal, thus minimizing stress. The design of the microstimulator allows to set the DBS parameters easily (intensity, frequency and pulse width) and to replace the battery for long-term DBS. To validate our device, we performed continuous DBS of the subthalamic nucleus (known to improve motor deficits in clinic) in a classical rat model of PD during 5 weeks. We show that this long duration stimulation reduces significantly PD-induced akinesia without inducing animal discomfort and tissue damage. These first data demonstrated that long term DBS procedure in behaving rat is now workable. PMID:22659685

Forni, Claude; Mainard, Olivier; Melon, Christophe; Goguenheim, Didier; Kerkerian-Le Goff, Lydia; Salin, Pascal

2012-07-30

264

Thinking Ahead on Deep Brain Stimulation: An Analysis of the Ethical Implications of a Developing Technology  

PubMed Central

Deep brain stimulation (DBS) is a developing technology. New generations of DBS technology are already in the pipeline, yet this particular fact has been largely ignored among ethicists interested in DBS. Focusing only on ethical concerns raised by the current DBS technology is, albeit necessary, not sufficient. Since current bioethical concerns raised by a specific technology could be quite different from the concerns it will raise a couple of years ahead, an ethical analysis should be sensitive to such alterations, or it could end up with results that soon become dated. The goal of this analysis is to address these changing bioethical concerns, to think ahead on upcoming and future DBS concerns both in terms of a changing technology and changing moral attitudes. By employing the distinction between inherent and noninherent bioethical concerns we identify and make explicit the particular limits and potentials for change within each category, respectively, including how present and upcoming bioethical concerns regarding DBS emerge and become obsolete. Many of the currently identified ethical problems with DBS, such as stimulation-induced mania, are a result of suboptimal technology. These challenges could be addressed by technical advances, while for instance perceptions of an altered body image caused by the mere awareness of having an implant may not. Other concerns will not emerge until the technology has become sophisticated enough for new uses to be realized, such as concerns on DBS for enhancement purposes. As a part of the present analysis, concerns regarding authenticity are used as an example.

Johansson, Veronica; Garwicz, Martin; Kanje, Martin; Halldenius, Lena; Schouenborg, Jens

2014-01-01

265

Electrical Stimulation for Drug-Resistant Epilepsy  

PubMed Central

Objective The objective of this analysis was to evaluate the effectiveness of deep brain stimulation (DBS) and vagus nerve stimulation (VNS) for the treatment of drug-resistant epilepsy in adults and children. Data Sources A literature search was performed using MEDLINE, EMBASE, the Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published from January 2007 until December 2012. Review Methods Systematic reviews, meta-analyses, randomized controlled trials (RCTs), and observational studies (in the absence of RCTs) of adults or children were included. DBS studies were included if they specified that the anterior nucleus of thalamus was the area of the brain stimulated. Outcomes of interest were seizure frequency, health resource utilization, and safety. A cost analysis was also performed. Results The search identified 6 studies that assessed changes in seizure frequency after electrical stimulation: 1 RCT on DBS in adults, 4 RCTs on VNS in adults, and 1 RCT on VNS in children. The studies of DBS and VNS in adults found significantly improved rates of seizure frequency, but the study of VNS in children did not find a significant difference in seizure frequency between the high and low stimulation groups. Significant reductions in hospitalizations and emergency department visits were found for adults and children who received VNS. No studies addressed the use of health resources for patients undergoing DBS. Five studies reported on adverse events, which ranged from serious to transient for both procedures in adults and were mostly transient in the 1 study of VNS in children. Limitations We found no evidence on DBS in children or on health care use related to DBS. The measurement of seizure frequency is self-reported and is therefore subject to bias and issues of compliance. Conclusions Based on evidence of low to moderate quality, both DBS and VNS seemed to reduce seizure frequency in adults. In children, VNS did not appear to be as effective at reducing seizure frequency, but children had significantly fewer hospitalizations and ED visits after VNS implantation. Despite the considerable risks associated with these invasive procedures, long-term adverse events appear to be limited. Plain Language Summary Electrical stimulation of specific areas of the brain is a procedure used to control epileptic seizures when more conventional treatments are not working. Most adults and children with epilepsy are able to control their seizures with medication, but for some patients, drugs are not effective and surgery to remove the part of the brain where the seizures start is not an appropriate option. This study looked at the research available on the effectiveness, safety, and cost of two types of electrical stimulation devices currently licensed for treatment of epilepsy for adults and children in Canada: vagus nerve stimulation (VNS) and deep brain stimulation (DBS). Both approaches appear to be effective at reducing the frequency of seizures in adults. However, the evidence on DBS is limited to a single study with adults; we found no studies of DBS with children. Studies on VNS showed that both adults and children had fewer hospitalizations and emergency department visits after the procedure. Both procedures carry serious risks, but several longer-term studies have found that adverse events appear to be limited. The cost of VNS, including the process of assessing whether or not patients are good candidates for the procedure, is estimated to be about $40,000 per person (and higher for DBS because the device is more expensive and the operating time is longer). Of the 70,000 people in Ontario with epilepsy, about 1,400 (300 children and 1,110 adults) may be candidates for VNS to reduce their seizures.

Chambers, A; Bowen, JM

2013-01-01

266

Subthalamic nucleus stimulation affects incentive salience attribution in Parkinson's disease.  

PubMed

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) can induce nonmotor side effects such as behavioral and mood disturbances or body weight gain in Parkinson's disease (PD) patients. We hypothesized that some of these problems could be related to an altered attribution of incentive salience (ie, emotional relevance) to rewarding and aversive stimuli. Twenty PD patients (all men; mean age ± SD, 58.3 ± 6 years) in bilateral STN DBS switched ON and OFF conditions and 18 matched controls rated pictures selected from the International Affective Picture System according to emotional valence (unpleasantness/pleasantness) and arousal on 2 independent visual scales ranging from 1 to 9. Eighty-four pictures depicting primary rewarding (erotica and food) and aversive fearful (victims and threat) and neutral stimuli were selected for this study. In the STN DBS ON condition, the PD patients attributed lower valence scores to the aversive pictures compared with the OFF condition (P < .01) and compared with controls (P < .01). The difference between the OFF condition and controls was less pronounced (P < .05). Furthermore, postoperative weight gain correlated with arousal ratings from the food pictures in the STN DBS ON condition (P < .05 compensated for OFF condition). Our results suggest that STN DBS increases activation of the aversive motivational system so that more relevance is attributed to aversive fearful stimuli. In addition, STN DBS-related sensitivity to food reward stimuli cues might drive DBS-treated patients to higher food intake and subsequent weight gain. PMID:21780183

Serranová, Tereza; Jech, Robert; Dušek, Petr; Sieger, Tomáš; R?ži?ka, Filip; Urgošík, Dušan; R?ži?ka, Evžen

2011-10-01

267

Chronic sacral spinal nerve stimulation for fecal incontinence: Long-term results with foramen and cuff electrodes  

Microsoft Academic Search

PURPOSE: Sacral spinal nerve stimulation is a new therapeutic approach for patients with severe fecal incontinence owing to functional deficits of the external anal sphincter. It aims to use the morphologically intact anatomy to recruit residual function. This study evaluates the long-term results of the first patients treated with this novel approach applying two techniques of sacral spinal nerve stimulator

Klaus E. Matzel; Uwe Stadelmaier; Markus Hohenfellner; Werner Hohenberger

2001-01-01

268

Brain stimulation in posttraumatic stress disorder.  

PubMed

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 reducing anxiety, findings that may suggest possible utility in relieving PTSD-associated anxiety. Treatment of animal models of PTSD with DBS suggests potential human benefit. Additional research and novel treatment options for PTSD are urgently needed. The potential usefulness of brain stimulation in treating PTSD deserves further exploration. PMID:22893803

Novakovic, Vladan; Sher, Leo; Lapidus, Kyle A B; Mindes, Janet; A Golier, Julia; Yehuda, Rachel

2011-01-01

269

Deep Brain Stimulation of Caudal Zona Incerta and Subthalamic Nucleus in Patients with Parkinson's Disease: Effects on Diadochokinetic Rate  

PubMed Central

The hypokinetic dysarthria observed in Parkinson's disease (PD) affects the range, speed, and accuracy of articulatory gestures in patients, reducing the perceived quality of speech acoustic output in continuous speech. Deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) and of the caudal zona incerta (cZi-DBS) are current surgical treatment options for PD. This study aimed at investigating the outcome of STN-DBS (7 patients) and cZi-DBS (7 patients) in two articulatory diadochokinesis tasks (AMR and SMR) using measurements of articulation rate and quality of the plosive consonants (using the percent measurable VOT metric). The results indicate that patients receiving STN-DBS increased in articulation rate in the Stim-ON condition in the AMR task only, with no effect on production quality. Patients receiving cZi-DBS decreased in articulation rate in the Stim-ON condition and further showed a reduction in production quality. The data therefore suggest that cZi-DBS is more detrimental for extended articulatory movements than STN-DBS.

Karlsson, Fredrik; Unger, Elin; Wahlgren, Sofia; Blomstedt, Patric; Linder, Jan; Nordh, Erik; Zafar, Hamayun; van Doorn, Jan

2011-01-01

270

Evolution of Deep Brain Stimulation: Human Electrometer and Smart Devices Supporting the Next Generation of Therapy  

PubMed Central

Deep Brain Stimulation (DBS) provides therapeutic benefit for several neuropathologies including Parkinson’s disease (PD), epilepsy, chronic pain, and depression. Despite well established clinical efficacy, the mechanism(s) of DBS remains poorly understood. In this review we begin by summarizing the current understanding of the DBS mechanism. Using this knowledge as a framework, we then explore a specific hypothesis regarding DBS of the subthalamic nucleus (STN) for the treatment of PD. This hypothesis states that therapeutic benefit is provided, at least in part, by activation of surviving nigrostriatal dopaminergic neurons, subsequent striatal dopamine release, and resumption of striatal target cell control by dopamine. While highly controversial, we present preliminary data that are consistent with specific predications testing this hypothesis. We additionally propose that developing new technologies, e.g., human electrometer and closed-loop smart devices, for monitoring dopaminergic neurotransmission during STN DBS will further advance this treatment approach.

Lee, Kendall H.; Blaha, Charles D.; Garris, Paul A.; Mohseni, Pedram; Horne, April E.; Bennet, Kevin E.; Agnesi, Filippo; Bledsoe, Jonathan M.; Lester, Deranda B.; Kimble, Chris; Min, Hoon-Ki; Kim, Young-Bo; Cho, Zang-Hee

2010-01-01

271

Chronic Deep Brain Stimulation of the Subthalamic Nucleus for Parkinson’s Disease: Effects on Cognition, Mood, Anxiety and Personality Traits  

Microsoft Academic Search

Objective: To evaluate modifications occurring in cognitive functions and behavioural aspects in a group of 72 consecutive patients with Parkinson’s disease (PD) 15 months after bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN). Methods: 72 consecutive PD patients bilaterally implanted for DBS of the STN were evaluated before and after surgery with a mean follow-up of 15 months.

L. Castelli; P. Perozzo; M. Zibetti; B. Crivelli; U. Morabito; M. Lanotte; F. Cossa; B. Bergamasco; L. Lopiano; O. Kastrup; M. Obermann; S. Esser; H. Wilhelm; C. Ley; J. Beilby; M. Bulsara; S. Hurnaus; W. Mueller-Felber

2006-01-01

272

Immediate effects of deep brain stimulation of anterior thalamic nuclei on executive functions and emotion-attention interaction in humans  

PubMed Central

Background Deep brain stimulation (DBS) of anterior thalamic nuclei (ANT) is a novel promising therapeutic method for treating refractory epilepsy. Despite reports of subjective memory impairments and mood disturbances in patients with ANT-DBS, little is known of its effects on cognitive and affective processes. Hypothesis The anterior thalamus has connections to prefrontal and limbic networks important for cognitive control and emotional reactivity. More specifically, anterior cingulate cortex (ACC), linked with ANT, has been assigned roles related to response inhibition and attention allocation to threat. Thus, we hypothesized ANT-DBS to influence executive functions, particularly response inhibition, and modulate emotional reactivity to threat. Method Twelve patients having undergone ANT-DBS for intractable epilepsy participated in the study. Patients performed a computer-based executive reaction time (RT) test—that is, a go/ no-go visual discrimination task with threat-related emotional distractors and rule switching, while the DBS was switched ON (5/5 mA constant current) and OFF every few minutes. Results ANT-DBS increased the amount of commission errors—that is, errors where subjects failed to withhold from responding. Furthermore, ANT-DBS slowed RTs in context of threat-related distractors. When stimulation was turned off, threat-related distractors had no distinct effect on RTs. Conclusion We found immediate objective effects of ANT-DBS on human cognitive control and emotion-attention interaction. We suggest that ANT-DBS compromised response inhibition and enhanced attention allocation to threat due to altered functioning of neural networks that involve the DBS-target, ANT, and the regions connected to it such as ACC. The results highlight the need to consider affective and cognitive side-effects in addition to the therapeutic effect when adjusting stimulation parameters. Furthermore, this study introduces a novel window into cognitive and affective processes by modulating the associative and limbic networks with direct stimulation of key nodes in the thalamus.

Sun, Lihua; Polvaara, Markus; Brause, Maarja; Lehtimaki, Kai; Haapasalo, Joonas; Mottonen, Timo; Vayrynen, Kirsi; Ogawa, Keith H.; Ohman, Juha; Peltola, Jukka

2014-01-01

273

Immediate effects of deep brain stimulation of anterior thalamic nuclei on executive functions and emotion-attention interaction in humans.  

PubMed

Background: Deep brain stimulation (DBS) of anterior thalamic nuclei (ANT) is a novel promising therapeutic method for treating refractory epilepsy. Despite reports of subjective memory impairments and mood disturbances in patients with ANT-DBS, little is known of its effects on cognitive and affective processes. Hypothesis: The anterior thalamus has connections to prefrontal and limbic networks important for cognitive control and emotional reactivity. More specifically, anterior cingulate cortex (ACC), linked with ANT, has been assigned roles related to response inhibition and attention allocation to threat. Thus, we hypothesized ANT-DBS to influence executive functions, particularly response inhibition, and modulate emotional reactivity to threat. Method: Twelve patients having undergone ANT-DBS for intractable epilepsy participated in the study. Patients performed a computer-based executive reaction time (RT) test-that is, a go/no-go visual discrimination task with threat-related emotional distractors and rule switching, while the DBS was switched ON (5/5 mA constant current) and OFF every few minutes. Results: ANT-DBS increased the amount of commission errors-that is, errors where subjects failed to withhold from responding. Furthermore, ANT-DBS slowed RTs in context of threat-related distractors. When stimulation was turned off, threat-related distractors had no distinct effect on RTs. Conclusion: We found immediate objective effects of ANT-DBS on human cognitive control and emotion-attention interaction. We suggest that ANT-DBS compromised response inhibition and enhanced attention allocation to threat due to altered functioning of neural networks that involve the DBS-target, ANT, and the regions connected to it such as ACC. The results highlight the need to consider affective and cognitive side-effects in addition to the therapeutic effect when adjusting stimulation parameters. Furthermore, this study introduces a novel window into cognitive and affective processes by modulating the associative and limbic networks with direct stimulation of key nodes in the thalamus. PMID:24839985

Hartikainen, Kaisa M; Sun, Lihua; Polvivaara, Markus; Brause, Maarja; Lehtimäki, Kai; Haapasalo, Joonas; Möttönen, Timo; Väyrynen, Kirsi; Ogawa, Keith H; Ohman, Juha; Peltola, Jukka

2014-06-01

274

A study of a contoured beam antenna for future Japanese DBS  

NASA Astrophysics Data System (ADS)

A study of contoured beam for future Japanese direct broadcasting satellites (DBS) with pattern analysis and test results for the full-scale bread board model are presented. The design of a contoured beam antenna consisting of a single offset shaped reflector and a feed horn is described as a means to optimize the radiating power for the territory. The antenna design has been conducted in the downlink frequency (12 GHz) and the analyzed radiation pattern is verified by measurement.

Shogen, Kazuyoshi; Nishida, Hayato; Toyama, Noboru; Obuchi, Tomoki; Miyata, Yoshihide; Miyatani, Satoshi

1992-03-01

275

Quantitation of tenofovir and emtricitabine in dried blood spots (DBS) with LC-MS/MS.  

PubMed

A reversed-phase high performance liquid chromatographic (LC), tandem mass spectrometry (MS/MS) assay for the determination of tenofovir (TFV) and emtricitabine (FTC) in dried blood spots (DBS) from human whole blood was developed and validated. Whole blood samples were spotted, dried, and a 3mm punch was extracted with methanol for analysis by LC-MS/MS utilizing stable isotope labeled internal standards. The assay was validated over the range of 2.5-1000ng/mL for TFV and 2.5-5000ng/mL for FTC. The method was accurate (within ±15% of control) and precise (coefficient of variation ?15%) for hematocrit concentrations ranging from 25% to 76%; using edge punches vs. center punches; and spot volumes of 10-50?L. Analytes were stable for five freeze/thaw cycles and up to 6 days at room temperature, whereas long-term storage required -20°C or -80°C. Comparison of TFV and FTC in DBS vs. plasma yielded r(2)?0.96, indicating that DBS can be used as a plasma alternative for pharmacokinetic analyses in vivo. PMID:24055850

Zheng, Jia-Hua; Guida, Louis A; Rower, Caitlin; Castillo-Mancilla, Jose; Meditz, Amie; Klein, Brandon; Kerr, Becky Jo; Langness, Jacob; Bushman, Lane; Kiser, Jennifer; Anderson, Peter L

2014-01-25

276

Non-stationary discharge patterns in motor cortex under subthalamic nucleus deep brain stimulation  

PubMed Central

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) directly modulates the basal ganglia (BG), but how such stimulation impacts the cortex upstream is largely unknown. There is evidence of cortical activation in 6-hydroxydopamine (OHDA)-lesioned rodents and facilitation of motor evoked potentials in Parkinson's disease (PD) patients, but the impact of the DBS settings on the cortical activity in normal vs. Parkinsonian conditions is still debated. We use point process models to analyze non-stationary activation patterns and inter-neuronal dependencies in the motor and sensory cortices of two non-human primates during STN DBS. These features are enhanced after treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which causes a consistent PD-like motor impairment, while high-frequency (HF) DBS (i.e., ?100 Hz) strongly reduces the short-term patterns (period: 3–7 ms) both before and after MPTP treatment, and elicits a short-latency post-stimulus activation. Low-frequency DBS (i.e., ?50 Hz), instead, has negligible effects on the non-stationary features. Finally, by using tools from the information theory [i.e., receiver operating characteristic (ROC) curve and information rate (IR)], we show that the predictive power of these models is dependent on the DBS settings, i.e., the probability of spiking of the cortical neurons (which is captured by the point process models) is significantly conditioned on the timely delivery of the DBS input. This dependency increases with the DBS frequency and is significantly larger for high- vs. low-frequency DBS. Overall, the selective suppression of non-stationary features and the increased modulation of the spike probability suggest that HF STN DBS enhances the neuronal activation in motor and sensory cortices, presumably because of reinforcement mechanisms, which perhaps involve the overlap between feedback antidromic and feed-forward orthodromic responses along the BG-thalamo-cortical loop.

Santaniello, Sabato; Montgomery, Erwin B.; Gale, John T.; Sarma, Sridevi V.

2012-01-01

277

Deep Brain Stimulation and Medication for Parkinsonian Tremor During Secondary Tasks  

PubMed Central

This study examined the efficacy of subthalamic nucleus (STN), deep brain stimulation (DBS), and medication for resting tremor during performance of secondary tasks. Hand tremor was recorded using accelerometry and electromyography (EMG) from 10 patients with Parkinson’s disease (PD) and ten matched control subjects. The PD subjects were examined off treatment, on STN DBS, on medication, and on STN DBS plus medication. In the first experiment, tremor was recorded in a quiet condition and during a cognitive task designed to enhance tremor. In the second experiment, tremor was recorded in a quiet condition and during isometric finger flexion (motor task) with the contralateral limb at 5% of the maximal voluntary contraction (MVC) that was designed to suppress tremor. Results showed that: (1) STN DBS and medication reduced tremor during a cognitive task that exacerbated tremor, (2) STN DBS normalized tremor frequency in both the quiet and cognitive task conditions, whereas tremor amplitude was only normalized in the quiet condition, (3) a secondary motor task reduced tremor in a similar manner to STN DBS. These findings demonstrate that STN DBS still suppresses tremor in the presence of a cognitive task. Furthermore, a secondary motor task of the opposite limb suppresses tremor to levels comparable to STN DBS.

Sturman, Molly M.; Vaillancourt, David E.; Metman, Leo Verhagen; Sierens, Diane K.; Bakay, Roy A.E.; Corcos, Daniel M.

2008-01-01

278

Pallidal stimulation for primary generalised dystonia: effect on cognition, mood and quality of life.  

PubMed

We investigated the effect of pallidal deep brain stimulation (GPi-DBS) in dystonia on cognition, mood, and quality of life and also assessed if DYT1 gene status influenced cognitive outcome following GPi-DBS. Fourteen patients with primary generalized dystonia (PGD) were assessed, measuring their estimated premorbid and current IQ, memory for words and faces, and working memory, language, executive function, and sustained attention, one month before and one year or more after surgery. Changes in mood and behaviour and quality of life were also assessed. There was a significant improvement of dystonia with GPi-DBS (69 % improvement in Burke-Fahn-Marsden score, p < 0.0001). Performance on five cognitive tests either improved or declined at post-surgical follow-up. Calculation of a reliable change index suggested that deterioration in sustained attention on the PASAT was the only reliable change (worse after surgery) in cognition with GPi-DBS. DYT1 gene status did not influence cognitive outcome following GPi-DBS. Depression, anxiety and apathy were not significantly altered, and ratings of health status on the EQ5D remained unchanged. In our sample, GPi-DBS was only associated with an isolated deficit on a test of sustained attention, confirming that GPi-DBS in PGD is clinically effective and safe, without adverse effects on the main domains of cognitive function. The dissociation between GPi-DBS improving dystonia, but not having a significant positive impact on the patients' QoL, warrants further investigation. PMID:24178706

Jahanshahi, Marjan; Torkamani, Mariam; Beigi, Mazda; Wilkinson, Leonora; Page, Donna; Madeley, Laura; Bhatia, Kailash; Hariz, Marwan; Zrinzo, Ludvic; Limousin, Patricia; Ruge, Diane; Tisch, Stephen

2014-01-01

279

Deep-Brain Stimulation for Basal Ganglia Disorders  

PubMed Central

The realization that medications used to treat movement disorders and psychiatric conditions of basal ganglia origin have significant shortcomings, as well as advances in the understanding of the functional organization of the brain, has led to a renaissance in functional neurosurgery, and particularly the use of deep brain stimulation (DBS). Movement disorders are now routinely being treated with DBS of ‘motor’ portions of the basal ganglia output nuclei, specifically the subthalamic nucleus and the internal pallidal segment. These procedures are highly effective and generally safe. Use of DBS is also being explored in the treatment of neuropsychiatric disorders, with targeting of the ‘limbic’ basal ganglia-thalamocortical circuitry. The results of these procedures are also encouraging, but many unanswered questions remain in this emerging field. This review summarizes the scientific rationale and practical aspects of using DBS for neurologic and neuropsychiatric disorders.

Wichmann, Thomas; DeLong, Mahlon R.

2011-01-01

280

Direct electrical stimulation of the somatosensory cortex in humans using electrocorticography electrodes: a qualitative and quantitative report  

NASA Astrophysics Data System (ADS)

Objective. Recently, electrocorticography-based brain-computer interfaces have been successfully used to translate cortical activity into control signals for external devices. However, the utility of such devices would be greatly enhanced by somatosensory feedback. Direct stimulation of somatosensory cortex evokes sensory perceptions, and is thus a promising option for closing the loop. Before this can be implemented in humans it is necessary to evaluate how changes in stimulus parameters are perceived and the extent to which they can be discriminated. Approach. Electrical stimulation was delivered to the somatosensory cortex of human subjects implanted with electrocorticography grids. Subjects were asked to discriminate between stimuli of different frequency and amplitude as well as to report the qualitative sensations elicited by the stimulation. Main results. In this study we show that in humans implanted with electrocorticography grids, variations in the amplitude or frequency of cortical electrical stimulation produce graded variations in percepts. Subjects were able to reliably distinguish between different stimuli. Significance. These results indicate that direct cortical stimulation is a feasible option for sensory feedback with brain-computer interface devices.

Johnson, L. A.; Wander, J. D.; Sarma, D.; Su, D. K.; Fetz, E. E.; Ojemann, J. G.

2013-06-01

281

A SI\\/PSI, RSMS data stream and PCR\\/PTS processing algorithm for Koreasat digital DBS system  

Microsoft Academic Search

The Koreasat DBS (digital broadcasting satellite) receiver (Kim et al. 1997) consists of a 45 cm antenna, LNB (low noise block), STB (set-top-box), smart card and remote-controller. In order to work with the DBS encoder, the STB should be designed and implemented to process an SI\\/PSI (service information\\/program specific information) and RSMS (resource and subscriber management system) (Kim et al.

Dong-Hee Han; Kyu-Tae Yang; Jin-Ho Kim

1998-01-01

282

The enhancement of neuronal cells wound healing with non-contact electric field stimulation by graphene electrodes  

NASA Astrophysics Data System (ADS)

Electrical stimulation affects cellular behaviors including division, migration and wound healing [1-3]. Cellular injury often occurs due to the imbalance of the endogenous electric field [3]. In order to recover from the injury, wound healing process requires various cellular changes such as regeneration, migration, and the enhancement of cytoskeletal proteins and growth factors. In previous reports, a weak non-contact electric field stimulation (nEFS) accelerates the cell migration as well as cell-to-cell coupling between neuronal cell junction which are accompanied by increasing of cytoskeletal proteins [4, 5]. In this paper, we further investigated the wound healing effect of the nEFS in the neuronal cells (SHSY5Y cells) with live cell optical imaging. Cells were cultured over the optically transparent graphenen EF stimulator. Cellular behavioral changes upon nEFS were recorded with live optical imaging during stimulation of 120 minutes. The ability of wound healing was significantly enhanced with the nEFS. In particular, nEFS significantly shorten the duration of wound healing process. Moreover, after treating cells with cytochalasin D, a block polymerization of the actin filaments, the nEFS significantly enhanced wound healing process of cytochalasin D treated neural cells as compared to the control neural cells. This study suggests that nEFS may provide an effective way to control neural cells repairing process from cellular injury. Further mechanism study about the effect of nEFS on the wound healing may shed new light on cellular behavior.

Lee, Sohee; Heo, Chaejeong; Lee, Si Young; Lee, Young Hee; Suh, Minah

2013-05-01

283

Deep brain stimulation of the ventral striatum increases BDNF in the fear extinction circuit.  

PubMed

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

Do-Monte, Fabricio H; Rodriguez-Romaguera, Jose; Rosas-Vidal, Luis E; Quirk, Gregory J

2013-01-01

284

Novel applications of deep brain stimulation  

PubMed Central

The success of deep brain stimulation (DBS) surgery in treating medically refractory symptoms of some movement disorders has inspired further investigation into a wide variety of other treatment-resistant conditions. These range from disorders of gait, mood, and memory to problems as diverse as obesity, consciousness, and addiction. We review the emerging indications, rationale, and outcomes for some of the most promising new applications of DBS in the treatment of postural instability associated with Parkinson's disease, depression, obsessive–compulsive disorder, obesity, substance abuse, epilepsy, Alzheimer?s-type dementia, and traumatic brain injury. These studies reveal some of the excitement in a field at the edge of a rapidly expanding frontier. Much work still remains to be done on basic mechanism of DBS, optimal target and patient selection, and long-term durability of this technology in treating new indications.

Sankar, Tejas; Tierney, Travis S.; Hamani, Clement

2012-01-01

285

A Review of Social and Relational Aspects of Deep Brain Stimulation in Parkinson's Disease Informed by Healthcare Provider Experiences  

PubMed Central

Background. Although the clinical effectiveness of deep brain stimulation (DBS) in Parkinson's disease is established, there has been less examination of its social aspects. Methods and Results. Building on qualitative comments provided by healthcare providers, we present four different social and relational issues (need for social support, changes in relationships (with self and partner) and challenges with regards to occupation and the social system). We review the literature from multiple disciplines on each issue. We comment on their ethical implications and conclude by establishing the future prospects for research with the possible expansion of DBS for psychiatric indications. Conclusions. Our review demonstrates that there are varied social issues involved in DBS. These issues may have significant impacts on the perceived outcome of DBS by patients. Moreover, the fact that the social impact of DBS is still not well understood in emerging psychiatric indications presents an important area for future examination.

Bell, Emily; Maxwell, Bruce; McAndrews, Mary Pat; Sadikot, Abbas F.; Racine, Eric

2011-01-01

286

Non-invasive stimulation therapies for the treatment of refractory pain.  

PubMed

Drug-refractory pain is an indication for neurostimulation therapy, which can be either non-invasive [mainly transcutaneous electrical nerve stimulation (TENS), repetitive Transcranial Magnetic Stimulation (rTMS), and transcranial direct current stimulation (tDCS)] or invasive which requires the intervention of a surgeon to implant electrodes and a pulse generator [peripheral nerve stimulation (PNS), nerve root stimulation (NRS), spinal cord stimulation (SCS), deep brain stimulation (DBS), and motor cortex stimulation (MCS)]. In this review, the respective mechanisms of action and efficacy of TENS, rTMS, and tDCS are discussed. The advantages of TENS include non-invasiveness and ease to use, so that the technique can be operated by the patient. TENS can be indicated as a first-line treatment in patients suffering from peripheral neuropathic pain if the painful area is limited and the sensory deficit moderate. The current best indications are chronic radiculopathies, mononeuropathies, and postherpetic pain. Test sessions allow to select suitable patients and to determine the site, frequency, and optimal intensity of stimulation. Three to four 30- to 60-minute sessions per day are usually recommended. With regard to rTMS, published randomized controlled studies in chronic neuropathic and non-neuropathic pain (fibromyalgia) reached a sufficient level of evidence to recommend this technique for the indication of implanted motor cortex stimulation for the treatment of refractory neuropathic pain or as a long-term treatment for pain syndromes, in which surgery is not indicated, such as fibromyalgia. Other indications, concerning either chronic or acute pain syndromes, such as postoperative pain, should be developed in parallel with the optimization of stimulation parameters. This also includes the availability of new coils and magnetic field waveforms and progress in neuronavigation techniques, especially by the integration of functional imaging and high-resolution EEG data. PMID:22846200

Nizard, Julien; Lefaucheur, Jean-Pascal; Helbert, Marion; de Chauvigny, Edwige; Nguyen, Jean-Paul

2012-07-01

287

Flexible retinal electrode array  

DOEpatents

An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

Okandan, Murat (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

2006-10-24

288

Micromachined electrode array  

DOEpatents

An electrode array is disclosed which has applications for neural stimulation and sensing. The electrode array, in certain embodiments, can include a plurality of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. In other embodiments of the electrode array, the electrodes can be fixed to the substrate. The electrode array can be formed from a combination of bulk and surface micromachining, and can include electrode tips having an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis.

Okandan, Murat (Edgewood, NM); Wessendorf, Kurt O. (Albuquerque, NM)

2007-12-11

289

Deep Brain Stimulation Imposes Complex Informational Lesions  

PubMed Central

Deep brain stimulation (DBS) therapy has become an essential tool for treating a range of brain disorders. In the resting state, DBS is known to regularize spike activity in and downstream of the stimulated brain target, which in turn has been hypothesized to create informational lesions. Here, we specifically test this hypothesis using repetitive joint articulations in two non-human Primates while recording single-unit activity in the sensorimotor globus pallidus and motor thalamus before, during, and after DBS in the globus pallidus (GP) GP-DBS resulted in: (1) stimulus-entrained firing patterns in globus pallidus, (2) a monophasic stimulus-entrained firing pattern in motor thalamus, and (3) a complete or partial loss of responsiveness to joint position, velocity, or acceleration in globus pallidus (75%, 12/16 cells) and in the pallidal receiving area of motor thalamus (ventralis lateralis pars oralis, VLo) (38%, 21/55 cells). Despite loss of kinematic tuning, cells in the globus pallidus (63%, 10/16 cells) and VLo (84%, 46/55 cells) still responded to one or more aspects of joint movement during GP-DBS. Further, modulated kinematic tuning did not always necessitate modulation in firing patterns (2/12 cells in globus pallidus; 13/23 cells in VLo), and regularized firing patterns did not always correspond to altered responses to joint articulation (3/4 cells in globus pallidus, 11/33 cells in VLo). In this context, DBS therapy appears to function as an amalgam of network modulating and network lesioning therapies.

Agnesi, Filippo; Connolly, Allison T.; Baker, Kenneth B.; Vitek, Jerrold L.; Johnson, Matthew D.

2013-01-01

290

Longterm deep brain stimulation withdrawal: Clinical stability despite electrophysiological instability.  

PubMed

Deep brain stimulation (DBS) is a powerful treatment option for movement disorders, including severe generalised dystonia. After several years of treatment, cases have been reported in which DBS has been stopped without any deterioration in clinical benefit. This might indicate that DBS can restore function in some cases. The mechanism of DBS induced clinical retention effects has been addressed before. Here, the question we asked was if such clinical stability is reflected at the underlying physiology level or whether there is indication to believe that a stand-still of symptoms might be at risk because of neurophysiological instability. We recorded patients with pre-intervention life-threatening or severe genetic dystonia with long lasting clinical benefit when turned off DBS. Despite clinical stability, our physiological studies revealed large changes in the excitability of excitatory and inhibitory motor circuits in the cortex, which exceed normal fluctuation. This discrepancy between instability in the motor network physiology caused by removal of DBS and clinical stability alerts as it potentially indicates a risk to fail and cause symptoms to return. PMID:24857354

Ruge, Diane; Cif, Laura; Limousin, Patricia; Gonzalez, Victoria; Vasques, Xavier; Coubes, Philippe; Rothwell, John C

2014-07-15

291

Perimodiolar electrodes—radiological and histological findings  

Microsoft Academic Search

New electrode developments try to place stimulating electrodes near to the modiolus. Possible advantages are lower stimulation thresholds and a better channel separation. A position close to the modiolus can be facilitated by different means: preformed electrode shape (Contour™ electrode, Cochlear, Australia), additional positioning elements like silicon in a space-filling matter (Clarion 1.2® electrode with positioner and HiFocus® electrode with

A. Aschendorff; T. Klenzner; M. Hamad; R. Kubalek; B. Richter; R. Laszig

2003-01-01

292

Deep Brain Stimulation of Two Unconventional Targets in Refractory Non-Resectable Epilepsy  

Microsoft Academic Search

Introduction: Several deep brain targets have been assessed for the treatment of unresectable refractory epileptic conditions. Adrian Upton in 1985 proposed deep brain stimulation (DBS) of the anterior nucleus of the thalamus for the treatment of seizures and psychosis [Cooper I.S., Upton A.R.: Biol Psychiatry 1985;20:811–813]. Francisco Velasco, in 1987, introduced DBS of the thalamic centromedian nucleus, proposing its employment

Angelo Franzini; Giuseppe Messina; Carlo Marras; Flavio Villani; Roberto Cordella; Giovanni Broggi

2008-01-01

293

Deep Brain Stimulation of the Pedunculopontine Nucleus in a Patient with Freezing of Gait  

Microsoft Academic Search

Case Presentation: A 54-year-old male patient presenting probable multiple system atrophy with predominant parkinsonism who underwent bilateral deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) is presented. The patient had dominant freezing of gait (FOG), levodopa-resistant bradykinesia, and autonomic disturbances, but with a good cognitive condition. Methods: The patient underwent bilateral DBS of the PPN, which ended with modest

Feridun Acar; Göksemin Acar; Levent Sinan Bir; Bengi Gedik

2011-01-01

294

Long-term high frequency deep brain stimulation of the nucleus accumbens drives time-dependent changes in functional connectivity in the rodent limbic system.  

PubMed

Deep brain stimulation of the ventral striatum is an effective treatment for a variety of treatment refractory psychiatric disorders yet the mechanism of action remains elusive. We examined how five days of stimulation affected rhythmic brain activity in freely moving rats in terms of oscillatory power within, and coherence between, selected limbic regions bilaterally. Custom made bipolar stimulating/recording electrodes were implanted, bilaterally, in the nucleus accumbens core. Local field potential (LFP) recording electrodes were implanted, bilaterally in the prelimbic and orbitofrontal cortices and mediodorsal thalamic nucleus. Stimulation was delivered bilaterally with 100 ?s duration constant current pulses at a frequency of 130 Hz delivered at an amplitude of 100 ?A using a custom-made stimulation device. Synchronized video and LFP data were collected from animals in their home cages before, during and after stimulation. Signals were processed to remove movement and stimulation artifacts, and analyzed to determine changes in spectral power within, and coherence between regions. Five days stimulation of the nucleus accumbens core yielded temporally dynamic modulation of LFP power in multiple bandwidths across multiple brain regions. Coherence was seen to decrease in the alpha band between the mediodorsal thalamic nucleus and core of the nucleus accumbens. Coherence between each core of the nucleus accumbens bilaterally showed rich temporal dynamics throughout the five day stimulation period. Stimulation cessation revealed significant "rebound" effects in both power and coherence in multiple brain regions. Overall, the initial changes in power observed with short-term stimulation are replaced by altered coherence, which may reflect the functional action of DBS. PMID:22981894

Ewing, Samuel G; Grace, Anthony A

2013-05-01

295

A NEAR-INFRARED STUDY OF THE STELLAR CLUSTER: [DBS2003] 45  

SciTech Connect

We present a multi-wavelength photometric and spectroscopic study of a newly discovered candidate cluster [DBS2003] 45. Our H, Ks photometry confirms that [DBS2003] 45 is a cluster. An average visual extinction A{sub V} {approx} 7.1 {+-} 0.5 is needed to fit the cluster sequence with a model isochrone. Low-resolution spectroscopy indicates that half a dozen early B- and at least one late O-type giant stars are present in the cluster. We estimate the age of the cluster to be between 5 and 8 Myr based on spectroscopic analysis. Assuming an age of 6 Myr, we fit the observed mass function with a power law, N(M) {proportional_to} M {sup -{gamma}}, and find an index {gamma} {approx} 1.27 {+-} 0.15, which is consistent with the Salpeter value. We estimate that the total cluster mass is around 10{sup 3} M {sub sun} by integrating the derived mass function between 0.5 and 45 M{sub sun}. Both mid-infrared and radio wavelength observations show that a bubble filled with ionized gas is associated with the cluster. The total ionizing photon flux estimated from radio continuum measurements is consistent with the number of hot stars we detected. Infrared bright point sources along the rim of the bubble suggest that there is triggered star formation at the periphery of the H II region.

Zhu Qingfeng [Key Laboratory for Researches in Galaxies and Cosmology, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui, 230026 (China); Davies, Ben [School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Figer, Donald F.; Trombley, Christine [Chester F. Carlson Center for Imaging Science, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623-5604 (United States)], E-mail: zhuqf@ustc.edu.cn, E-mail: b.davies@leeds.ac.uk, E-mail: figer@cis.rit.edu, E-mail: cmtpci@cis.rit.edu

2009-09-10

296

Subthalamic stimulation affects homophone meaning generation in Parkinson's disease.  

PubMed

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) in individuals with Parkinson's disease (PD) has often been associated with reduced verbal fluency performance. This study aimed to directly assess semantic switching as a function of STN stimulation in PD participants with the Homophone Meaning Generation Test (HMGT). Seventeen participants with PD who had received STN DBS completed the HMGT in on and off stimulation conditions. Twenty-one non-neurologically impaired participants acted as controls. PD participants (in both on and off stimulation conditions) generated significantly fewer meanings than control participants and consistent with the previous reports of verbal fluency impairment, PD participants produced fewer definitions in the on stimulation condition. PD participants (in both on and off stimulation conditions) also had greater difficulty generating definitions for nonhomographic homophones compared with homographic homographs. The results of this study indicate that STN stimulation exacerbates impairment in semantic switching. PMID:18764985

Castner, Joanna E; Copland, David A; Silburn, Peter A; Coyne, Terry J; Sinclair, Felicity; Chenery, Helen J

2008-09-01

297

Deep brain stimulation of the subthalamic or entopeduncular nucleus attenuates vacuous chewing movements in a rodent model of tardive dyskinesia.  

PubMed

Deep brain stimulation (DBS) has recently emerged as a potential intervention for treatment-resistant tardive dyskinesia (TD). Despite promising case reports, no consensus exists as yet regarding optimal stimulation parameters or neuroanatomical target for DBS in TD. Here we report the use of DBS in an animal model of TD. We applied DBS (100 ?A) acutely to the entopeduncular nucleus (EPN) or subthalamic nucleus (STN) in rats with well established vacuous chewing movements (VCMs) induced by 12 weeks of haloperidol (HAL) treatment. Stimulation of the STN or EPN resulted in significant reductions in VCM counts at frequencies of 30, 60 or 130 Hz. In the STN DBS groups, effects were significantly more pronounced at 130 Hz than at lower frequencies, whereas at the EPN the three frequencies were equipotent. Unilateral stimulation at 130 Hz was also effective when applied to either nucleus. These results suggest that stimulation of either the EPN or STN significantly alleviates oral dyskinesias induced by chronic HAL. The chronic HAL VCM model preparation may be useful to explore mechanisms underlying DBS effects in drug-induced dyskinesias. PMID:20624675

Creed, Meaghan; Hamani, Clement; Nobrega, José N

2011-05-01

298

Swallowing and deep brain stimulation in Parkinson's disease: a systematic review.  

PubMed

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

Troche, Michelle S; Brandimore, Alexandra E; Foote, Kelly D; Okun, Michael S

2013-09-01

299

Swallowing and deep brain stimulation in Parkinson's disease: A systematic review  

PubMed Central

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.

Troche, Michelle S.; Brandimore, Alexandra E.; Foote, Kelly D.; Okun, Michael S.

2013-01-01

300

Timing of deep brain stimulation in Parkinson disease: a need for reappraisal?  

PubMed

We review the current application of deep brain stimulation (DBS) in Parkinson disease (PD) and consider the evidence that earlier use of DBS confers long-term symptomatic benefit for patients compared to best medical therapy. Electronic searches were performed of PubMed, Web of Knowledge, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials to identify all article types relating to the timing of DBS in PD. Current evidence suggests that DBS is typically performed in late stage PD, a mean of 14 to 15 years after diagnosis. Current guidelines recommend that PD patients who are resistant to medical therapies, have significant medication side effects and lengthening off periods, but are otherwise cognitively intact and medically fit for surgery be considered for DBS. If these criteria are rigidly interpreted, it may be that, by the time medical treatment options have been exhausted, the disease has progressed to the point that the patient may no longer be fit for neurosurgical intervention. From the evidence available, we conclude that surgical management of PD alone or in combination with medical therapy results in greater improvement of motor symptoms and quality of life than medical treatment alone. There is evidence to support the use of DBS in less advanced PD and that it may be appropriate for earlier stages of the disease than for which it is currently used. The improving short and long-term safety profile of DBS makes early application a realistic possibility. PMID:23483564

deSouza, Ruth-Mary; Moro, Elena; Lang, Anthony E; Schapira, Anthony H V

2013-05-01

301

Sustained Medication Reduction Following Unilateral VIM Thalamic Stimulation for Essential Tremor  

PubMed Central

Background Deep brain stimulation (DBS) is an increasingly utilized therapeutic modality for the management of medication refractory essential tremor (ET). The aim of this study was to determine whether DBS allowed for anti-tremor medication reduction within the year after the procedure was performed. Methods We conducted a retrospective chart review and telephone interviews on 34 consecutive patients who had been diagnosed with ET, and who had undergone unilateral DBS surgery. Results Of the 34 patients in our cohort, 31 patients (91%) completely stopped all anti-tremor medications either before surgery (21 patients, 62%) or in the year following DBS surgery (10 patients, 29%). Patients who discontinued tremor medications before DBS surgery did so because their tremors either became refractory to anti-tremor medication, or they developed adverse events to tremor medications. Patients who stopped tremor medications after DBS surgery did so due to sufficient tremor control. Only three patients (9%) who were taking tremor medications at the time of surgery continued the use of a beta-blocker post-operatively for the purpose of hypertension management in all cases. Discussion The data from this study indicate that medication cessation is common following unilateral DBS for ET.

Resnick, Andrew S.; Okun, Michael S.; Malapira, Teresita; Smith, Donald; Vale, Fernando L.; Sullivan, Kelly; Miller, Amber; Jahan, Israt; Zesiewicz, Theresa

2012-01-01

302

Two-Year Outcomes of Deep Brain Stimulation in Adults With Cerebral Palsy  

PubMed Central

Objective To investigate the effect of deep brain stimulation (DBS) on reducing dystonia and disability in adults with cerebral palsy (CP) and to compare the therapeutic outcomes between primary dystonia patients and CP patients over two years after bilateral pallidal DBS. Methods Five patients with primary dystonia and seven CP patients with dystonia were recruited. All subjects received DBS surgery in both globus pallidus. Burke-Fahn-Marsden dystonia rating scale consisting of dystonia movement score and disability score and subjective satisfaction scale were assessed after 1 month and every 6 months over two years following DBS treatment. Results On the dystonia movement scale, both groups of primary dystonia patients and CP patients showed a significant decrease over time following DBS. On the disability scale, patients with primary dystonia showed a significant decrease over time, whereas the disability score of CP patients did not change over the two years. Comparing the dystonia movement and disability scores of CP patients at each assessment, patients with primary dystonia showed a significant reduction after 6 months. Comparing the satisfaction scores of CP patients after DBS, patients with primary dystonia showed significantly higher subjective satisfaction. Conclusion Whereas dystonia can be significantly reduced in patients with primary dystonia, CP patients showed a modest improvement on the dystonia movement scale, but not on the disability scale. Therefore, DBS may be considered with caution as a treatment modality of CP patients with dystonia.

Kim, Ae Ryoung; Chang, Jin Woo; Chang, Won Seok; Park, Eun Sook

2014-01-01

303

Timing of Deep Brain Stimulation in Parkinson Disease: A Need for Reappraisal?  

PubMed Central

We review the current application of deep brain stimulation (DBS) in Parkinson disease (PD) and consider the evidence that earlier use of DBS confers long-term symptomatic benefit for patients compared to best medical therapy. Electronic searches were performed of PubMed, Web of Knowledge, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials to identify all article types relating to the timing of DBS in PD. Current evidence suggests that DBS is typically performed in late stage PD, a mean of 14 to 15 years after diagnosis. Current guidelines recommend that PD patients who are resistant to medical therapies, have significant medication side effects and lengthening off periods, but are otherwise cognitively intact and medically fit for surgery be considered for DBS. If these criteria are rigidly interpreted, it may be that, by the time medical treatment options have been exhausted, the disease has progressed to the point that the patient may no longer be fit for neurosurgical intervention. From the evidence available, we conclude that surgical management of PD alone or in combination with medical therapy results in greater improvement of motor symptoms and quality of life than medical treatment alone. There is evidence to support the use of DBS in less advanced PD and that it may be appropriate for earlier stages of the disease than for which it is currently used. The improving short and long-term safety profile of DBS makes early application a realistic possibility. Ann Neurol 2013;73:565–575

deSouza, Ruth-Mary; Moro, Elena; Lang, Anthony E; Schapira, Anthony H V

2013-01-01

304

Modeling the Effects of Deep Brain Stimulation on Sensorimotor Cortex in Normal and MPTP Conditions  

PubMed Central

Deep Brain Stimulation (DBS) is an effective surgical therapy for the treatment of movement disorders in Parkinson’s disease (PD) and other neurological pathologies. DBS is known to modulate the spiking activity of the neurons within the basal ganglia, but how such modulation impacts the primary sensorimotor cortex is still uncertain. In this study a monkey was stimulated with DBS at several frequencies in the subthalamic nucleus (STN) before and after treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to develop PD symptoms, while single unit recordings are simultaneously obtained from the sensorimotor cortex. We exploit such data to develop point-process input-output models of the cortical neurons. Our models describe the effects of stimulation in normal and MPTP conditions and investigate the influence of the stimulation frequency on the neuronal activity. Our models show increased synchronization of the cortical neurons in MPTP vs. normal conditions before stimulation, suggest that STN DBS impacts the cortical activity by antidromically eliciting spikes at the stimulation frequency, and support the hypothesis that high frequency DBS partially masks the effects of thalamo-cortical input.

Santaniello, S.; Gale, J. T.; Montgomery, E. B.; Sarma, S. V.

2014-01-01

305

Restoring the Basal Ganglia in Parkinson's disease to Normal via Multi-Input Phase-Shifted Deep Brain Stimulation  

PubMed Central

Deep brain stimulation (DBS) injects a high frequency current that effectively disables the diseased basal ganglia (BG) circuit in Parkinson’s disease (PD) patients, leading to a reversal of motor symptoms. Though therapeutic, high frequency stimulation consumes significant power forcing frequent surgical battery replacements and causing widespread influence into other brain areas which may lead to adverse side effects. In this paper, we conducted a rigorous study to assess whether low frequency signals can restore behavior in PD patients by restoring neural activity in the BG to the normal state. We used a biophysical-based model of BG nuclei and motor thalamus whose parameters can be set to simulate the normal state and the PD state with and without DBS. We administered pulse train DBS waveforms to the subthalamic nucleus (STN) with frequencies ranging from 1–150Hz. For each DBS frequency, we computed statistics on the simulated neural activity to assess whether it is restored to the normal state. In particular, we searched for DBS waveforms that suppress pathological bursting, oscillations, correlations and synchronization prevalent in the PD state and that enable thalamic cells to relay cortical inputs reliably. We found that none of the tested waveforms restores neural activity to the normal state. However, our simulations led us to construct a novel DBS strategy involving low frequency multi-input phaseshifted DBS to be administered into the STN. This strategy successfully suppressed all pathological symptoms in the BG in addition to enabling thalamic cells to relay cortical inputs reliably.

Agarwal, Rahul; Sarma, Sridevi V.

2014-01-01

306

Deep brain stimulation of the ventral hippocampus restores deficits in processing of auditory evoked potentials in a rodent developmental disruption model of schizophrenia  

PubMed Central

Existing antipsychotic drugs are most effective at treating the positive symptoms of schizophrenia, but their relative efficacy is low and they are associated with considerable side effects. In this study deep brain stimulation of the ventral hippocampus was performed in a rodent model of schizophrenia (MAM-E17) in an attempt to alleviate one set of neurophysiological alterations observed in this disorder. Bipolar stimulating electrodes were fabricated and implanted, bilaterally, into the ventral hippocampus of rats. High frequency stimulation was delivered bilaterally via a custom-made stimulation device and both spectral analysis (power and coherence) of resting state local field potentials and amplitude of auditory evoked potential components during a standard inhibitory gating paradigm were examined. MAM rats exhibited alterations in specific components of the auditory evoked potential in the infralimbic cortex, the core of the nucleus accumbens, mediodorsal thalamic nucleus, and ventral hippocampus in the left hemisphere only. DBS was effective in reversing these evoked deficits in the infralimbic cortex and the mediodorsal thalamic nucleus of MAM-treated rats to levels similar to those observed in control animals. In contrast stimulation did not alter evoked potentials in control rats. No deficits or stimulation-induced alterations were observed in the prelimbic and orbitofrontal cortices, the shell of the nucleus accumbens or ventral tegmental area. These data indicate a normalization of deficits in generating auditory evoked potentials induced by a developmental disruption by acute high frequency, electrical stimulation of the ventral hippocampus.

Ewing, Samuel G.; Grace, Anthony A.

2012-01-01

307

Deep Brain Stimulation of the Globus Pallidus in a 7-Year-Old Girl with DYT1 Generalized Dystonia  

PubMed Central

The experience of pediatric deep brain stimulation (DBS) of the globus pallidus internus (GPi) in the treatment of early-onset DYT1 generalized dystonia is still limited. Here, we report the surgical experience of bilateral GPi-DBS under general anesthesia by using microelectrode recording in a 7-year-old girl with early-onset DYT1 generalized dystonia. Excellent improvement of her dystonia without neurological complications was achieved. This case report demonstrates that GPi-DBS is an effective and safe method for the treatment of medically refractory early-onset DYT1 generalized dystonia in children.

Jin, Seon Tak; Ghang, Ju Young; Jeon, Seong Man

2012-01-01

308

A linearized current stimulator for deep brain stimulation.  

PubMed

This paper develops the front end of the stimulator which is applied in the implantable deep brain stimulation (DBS) for the therapy of Parkinson's disease. This stimulator adopts the low power switched-capacitor DAC accompanying with voltage-to-current transconductance amplifiers to obtain the adjustable output currents. The proposed distortion cancellation technique improves the linearity of the current stimulator. Multiple transconductance amplifiers sharing a single DAC save the circuit area. The biphasic stimulation waveform is generated from the bridge switching technique and the programmable pulse. This stimulation circuit provides the 0 approximately 165 microA current for a typical loading of 10 k?, 8 approximately 120 micros pulse width, and 126 approximately 244 Hz frequencies with a 0.35 microm CMOS technology at 3.3 V supply voltage. PMID:21096724

Shen, Ding-Lan; Chu, Yu-Jung

2010-01-01

309

An introduction to the RARC '83 plan for DBS systems in the Western Hemisphere  

NASA Astrophysics Data System (ADS)

It is pointed out that the future development of direct broadcast satellite (DBS) systems around 12 GHz is now governed by frequency and orbital position assignment plans embracing every country in the world. The plan for ITU Region 1 and Region 3 was adopted at the World Administrative Radio Conference of 1977 (WARC '77), while the plan for ITU Region 2 countries was developed at the Regional Administrative Radio Conference of 1983 (RARC '83). The present paper is an adaptation of an article by Reinhart (1984). It has the aim to provide an introductory overview of the Region 2 Plan. Attention is given to the technical bases for the RARC '83 plan, the service areas and coverage areas, the channelization of the band, Orbital position and channel assignments, comparative orbit-spectrum utilization, and some operational features of the RARC '83 plan.

Reinhart, E. E.

1985-01-01

310

A study on the effect of electrical stimulation on living tissue: potential before, during and after galvanization with constant current of 20 microA through platinum electrodes.  

PubMed

Two platinum needles (therapeutic electrode) were inserted into the rabbit's auricle, and with the medial angle of the eye as the datum point of measurement, the electric potential was measured before, during, and after the galvanization with micro-current (20 microA). With the insertion of the needles alone, the potential between the needles and the datum point showed -0.10 to +0.28 V, which gradually decreased thereafter to reach stable levels ranging from -0.02 to +0.17 V in 3 or 4 days. When galvanized, the potential stood +0.75 to +1.30 V between the anode and the datum point, and -0.37 to -0.50 V between the cathode and the datum point. Then, 3 days later, the voltage rose +1.40 to +1.65V between the anode and the datum point, and went down -0.60 to -0.85 V between the cathode and the datum point. When the micro-current was switched off, the potential immediately decreased, and slight potential endured after 24 hrs. These findings revealed that the insertion of needles generated electric potentials, that galvanization charged the tissue, and that cessation of stimulation led to storage and discharge of electricity. PMID:2348597

Kubota, T; Sato, K

1990-04-01

311

The autonomic effects of deep brain stimulation--a therapeutic opportunity.  

PubMed

Deep brain stimulation (DBS) is an expanding field in neurosurgery and has already provided important insights into the fundamental mechanisms underlying brain function. One of the most exciting emerging applications of DBS is modulation of blood pressure, respiration and micturition through its effects on the autonomic nervous system. DBS stimulation at various sites in the central autonomic network produces rapid changes in the functioning of specific organs and physiological systems that are distinct from its therapeutic effects on central nervous motor and sensory systems. For example, DBS modulates several parameters of cardiovascular function, including heart rate, blood pressure, heart rate variability, baroreceptor sensitivity and blood pressure variability. The beneficial effects of DBS also extend to improvements in lung function. This article includes an overview of the anatomy of the central autonomic network, which consists of autonomic nervous system components in the cortex, diencephalon and brainstem that project to the spinal cord or cranial nerves. The effects of DBS on physiological functioning (particularly of the cardiovascular and respiratory systems) are discussed, and the potential for these findings to be translated into therapies for patients with autonomic diseases is examined. PMID:22688783

Hyam, Jonathan A; Kringelbach, Morten L; Silburn, Peter A; Aziz, Tipu Z; Green, Alexander L

2012-07-01

312

Pp65 antigenemia, plasma real-time PCR and DBS test in symptomatic and asymptomatic cytomegalovirus congenitally infected newborns  

PubMed Central

Background Many congenitally cytomegalovirus-infected (cCMV) neonates are at risk for severe consequences, even if they are asymptomatic at birth. The assessment of the viral load in neonatal blood could help in identifying the babies at risk of sequelae. Methods In the present study, we elaborated the results obtained on blood samples collected in the first two weeks of life from 22 symptomatic and 48 asymptomatic newborns with cCMV diagnosed through urine testing. We evaluated the performances of two quantitative methods (pp65 antigenemia test and plasma Real-time PCR) and the semi-quantitative results of dried blood sample (DBS) test in the aim of identifying a valid method for measuring viral load. Results Plasma qPCR and DBS tests were positive in 100% of cases, antigenemia in 81%. Only the latter test gave quantitatively different results in symptomatic versus asymptomatic children. qPCR values of 103 copies/ml were found in 52% of newborn. "Strong" DBS test positivity cases had higher median values of both pp65 positive PBL and DNA copies/ml than cases with a "weak" positivity. Conclusions As expected antigenemia test was less sensitive than molecular tests and DBS test performed better on samples with higher rates of pp65 positive PBL and higher numbers of DNA copies/ml. The prognostic significance of the results of these tests will be evaluated on completion of the ongoing collection of follow-up data of these children.

2010-01-01

313

Surgical and hardware complications of deep brain stimulation. A seven-year experience and review of the literature  

Microsoft Academic Search

Purpose  Deep brain stimulation (DBS) has been established as a safe and efficient method for the treatment of various movement disorders.\\u000a As the emerging applications continue to expand and more centers become eligible for the procedure, complication rates and\\u000a complication avoidance become increasingly important. Our aim was to report the DBS-related complication in our department\\u000a over the last 7 years, compare our

Efstathios J. Boviatsis; Lampis C. Stavrinou; Marios Themistocleous; Andreas T. Kouyialis; Damianos E. Sakas

2010-01-01

314

Long-Term Benefit Sustained after Bilateral Pallidal Deep Brain Stimulation in Patients with Refractory Tardive Dystonia  

Microsoft Academic Search

Background\\/Aims: Tardive dystonia (TD) can be a highly disabling, permanent condition related to the use of dopamine-receptor-blocking medications. Our aim was to evaluate the long-term effect of bilateral pallidal deep brain stimulation (DBS) for TD. Methods: Five consecutive patients with disabling TD who underwent stereotactic placement of bilateral globus pallidus internus DBS leads were included. All patients had a history

Edward F. Chang; Lauren E. Schrock; Philip A. Starr; Jill L. Ostrem

2010-01-01

315

Temporal patterns of deep brain stimulation generated with a true random number generator and the logistic equation: effects on CNS arousal in mice  

PubMed Central

Deep brain stimulation (DBS) has shown promise in the treatment of many neurological and psychiatric disorders as well as a disorder of consciousness, the minimally conscious state (MCS). In the clinic, DBS is always monotonic standard pulses; however, we have hypothesized that temporally patterned pulses might be more efficient in achieving desired behavioral responses. Here we present two experiments on DBS of the central thalamus to increase arousal, as measured by motor activity, and to affect the electroencephalogram (EEG). In the first, we optimized amplitude and frequency in standard stimulation of the central thalamus in intact mice. In the second, the optimized fixed frequency was compared to two alternative temporal patterns, chaotic and random, which were physically identical to each other and fixed frequency in all ways except temporal pattern. In both experiments and with all types of stimulation, DBS of the central thalamus increased arousal as measured by motor activity. These data also revealed that temporal patterning of pulses can modulate response to stimulation. That temporal patterns in DBS of the central thalamus were found to alter motor activity response implies possible usefulness of temporal patterns in DBS of other contexts. More investigation into exactly how temporally patterned stimulation may affect neuronal circuit dynamics is necessary.

Quinkert, A. W.; Pfaff, D. W.

2012-01-01

316

Superparamagnetic-bead Based Method: An Effective DNA Extraction from Dried Blood Spots (DBS) for Diagnostic PCR  

PubMed Central

Introduction: Storing blood as dried spots on filter paper is a trustworthy approach used in genetic screening issues which justifies the necessity for a reliable DNA extraction method. The present work aims to investigate the effectiveness of superparamagnetic-bead based method in extracting DNA from dried blood spots (DBS). Materials and Methods: Sixteen venous blood samples collected in K3-EDTA tubes (400?l of whole blood) were used for the spotting (4 circles each 100?l) on Ahlstrom 226 grad filter papers, for extraction and comparison. To ensure effectiveness, the extracted DNA was checked for quantity using the Quant-iT™ dsDNA Broad-Range Assay Kit and for quality by polymerase chain reaction (PCR) amplification of 344 bp segment of the HBB gene. Hybridization assays based on the dynamic allele specific hybridization (DASH) technique for two hemoglobin beta (HBB) mutations in genomic DNA extracted from DBS of ß-thalassemia patients were also performed to ensure the quality of extraction. Results: The results revealed a compatible effectiveness of the superparamagnetic-bead based method in extracting DNA from DBS particularly when incubating the DBS with lysis buffers BL+BLM overnight. A mean concentration of 21ng/ ?l was obtained with lysis buffers BL+BLM overnight incubation compared to 5.2 ng/?l for 2 h incubation with lysis buffers BL+BLM and 4.7 ng/?l when extraction performed using the lysis buffer BLM alone. Moreover, PCR amplification of 344 bp segment of the HBB showed a good quality of the extracted DNA. Conclusion: It was concluded that the superparamagnetic-bead based method is a reliable and effective method for DNA extraction from DBS and can be adopted for genetic diagnostic purposes.

2014-01-01

317

Superparamagnetic-bead Based Method: An Effective DNA Extraction from Dried Blood Spots (DBS) for Diagnostic PCR.  

PubMed

Introduction: Storing blood as dried spots on filter paper is a trustworthy approach used in genetic screening issues which justifies the necessity for a reliable DNA extraction method. The present work aims to investigate the effectiveness of superparamagnetic-bead based method in extracting DNA from dried blood spots (DBS). Materials and Methods: Sixteen venous blood samples collected in K3-EDTA tubes (400?l of whole blood) were used for the spotting (4 circles each 100?l) on Ahlstrom 226 grad filter papers, for extraction and comparison. To ensure effectiveness, the extracted DNA was checked for quantity using the Quant-iT™ dsDNA Broad-Range Assay Kit and for quality by polymerase chain reaction (PCR) amplification of 344 bp segment of the HBB gene. Hybridization assays based on the dynamic allele specific hybridization (DASH) technique for two hemoglobin beta (HBB) mutations in genomic DNA extracted from DBS of ß-thalassemia patients were also performed to ensure the quality of extraction. Results: The results revealed a compatible effectiveness of the superparamagnetic-bead based method in extracting DNA from DBS particularly when incubating the DBS with lysis buffers BL+BLM overnight. A mean concentration of 21ng/ ?l was obtained with lysis buffers BL+BLM overnight incubation compared to 5.2 ng/?l for 2 h incubation with lysis buffers BL+BLM and 4.7 ng/?l when extraction performed using the lysis buffer BLM alone. Moreover, PCR amplification of 344 bp segment of the HBB showed a good quality of the extracted DNA. Conclusion: It was concluded that the superparamagnetic-bead based method is a reliable and effective method for DNA extraction from DBS and can be adopted for genetic diagnostic purposes. PMID:24959449

Sirdah, Mahmoud Mohammed

2014-04-01

318

Subthalamic nucleus stimulation increases brain derived neurotrophic factor in the nigrostriatal system and primary motor cortex.  

PubMed

The mechanisms underlying the effects of long-term deep brain stimulation of the subthalamic nucleus (STN DBS) as a therapy for Parkinson's disease (PD) remain poorly understood. The present study examined whether functionally effective, long-term STN DBS modulates glial cell line-derived neurotrophic factor (GDNF) and/or brain-derived neurotrophic factor (BDNF) in both unlesioned and unilateral 6-hydroxydopamine lesioned rats. Lesioned rats that received two weeks of continuous unilateral STN DBS exhibited significant improvements in parkinsonian motor behaviors in tests of forelimb akinesia and rearing activity. Unilateral STN DBS did not increase GDNF in the nigrostriatal system, primary motor cortex (M1), or hippocampus of unlesioned rats. In contrast, unilateral STN DBS increased BDNF protein 2-3 fold bilaterally in the nigrostriatal system with the location (substantia nigra vs. striatum) dependent upon lesion status. Further, BDNF protein was bilaterally increased in M1 cortex by as much as 2 fold regardless of lesion status. STN DBS did not impact cortical regions that receive less input from the STN. STN DBS also was associated with bilateral increases in BDNF mRNA in the substantia nigra (SN) and internal globus pallidus (GPi). The increase observed in GPi was completely blocked by pretreatment with 5-Methyl-10,11-dihydro-5 H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801), suggesting that the activation of N-methyl-D-aspartate (NMDA) receptors was involved in this phenomenon. The upregulation of BDNF associated with long term STN DBS suggest that this therapy may exert pronounced and underappreciated effects on plasticity in the basal ganglia circuitry that may play a role in the symptomatic effects of this therapy as well as support the neuroprotective effect of stimulation documented in this rat model. PMID:22328911

Spieles-Engemann, Anne L; Steece-Collier, Kathy; Behbehani, Michael M; Collier, Timothy J; Wohlgenant, Susan L; Kemp, Christopher J; Cole-Strauss, Allyson; Levine, Nathan D; Gombash, Sara E; Thompson, Valerie B; Lipton, Jack W; Sortwell, Caryl E

2011-01-01

319

Subthalamic Nucleus Stimulation Increases Brain Derived Neurotrophic Factor in the Nigrostriatal System and Primary Motor Cortex  

PubMed Central

The mechanisms underlying the effects of long-term deep brain stimulation of the subthalamic nucleus (STN DBS) as a therapy for Parkinson’s disease (PD) remain poorly understood. The present study examined whether functionally effective, long-term STN DBS modulates glial cell line-derived neurotrophic factor (GDNF) and/or brain-derived neurotrophic factor (BDNF) in both unlesioned and unilateral 6-hydroxydopamine lesioned rats. Lesioned rats that received two weeks of continuous unilateral STN DBS exhibited significant improvements in parkinsonian motor behaviors in tests of forelimb akinesia and rearing activity. Unilateral STN DBS did not increase GDNF in the nigrostriatal system, primary motor cortex (M1), or hippocampus of unlesioned rats. In contrast, unilateral STN DBS increased BDNF protein 2–3 fold bilaterally in the nigrostriatal system with the location (substantia nigra vs. striatum) dependent upon lesion status. Further, BDNF protein was bilaterally increased in M1 cortex by as much as 2 fold regardless of lesion status. STN DBS did not impact cortical regions that receive less input from the STN. STN DBS also was associated with bilateral increases in BDNF mRNA in the substantia nigra (SN) and internal globus pallidus (GPi). The increase observed in GPi was completely blocked by pretreatment with 5-Methyl-10,11-dihydro-5 H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801), suggesting that the activation of N-methyl-D-aspartate (NMDA) receptors was involved in this phenomenon. The upregulation of BDNF associated with long term STN DBS suggest that this therapy may exert pronounced and underappreciated effects on plasticity in the basal ganglia circuitry that may play a role in the symptomatic effects of this therapy as well as support the neuroprotective effect of stimulation documented in this rat model.

Spieles-Engemann, Anne L.; Steece-Collier, Kathy; Behbehani, Michael M.; Collier, Timothy J.; Wohlgenant, Susan L.; Kemp, Christopher J.; Cole-Strauss, Allyson; Levine, Nathan D.; Gombash, Sara E.; Thompson, Valerie B.; Lipton, Jack W.; Sortwell, Caryl E.

2011-01-01

320

Deep brain and motor cortex stimulation.  

PubMed

Deep brain stimulation (DBS) and motor cortex stimulation (MCS) are established surgical modalities that have been successfully used over the last several decades for treatment of numerous chronic pain disorders. Most often, these approaches are reserved for severe, disabling, and medically refractory syndromes after less invasive approaches have been tried and have failed. Although the exact mechanism of action for DBS and MCS remains unknown, it appears that these central neuromodulation processes have multifactorial effects on central pain processing and descending pain inhibition. Clinical studies and laboratory reports have shed some light on stimulation details and optimal parameters, as well as the choice of stimulation targets, best surgical indications, and expected long-term outcomes. Based on the worldwide published experience, it appears that additional data is needed to obtain regulatory approval for both MCS and DBS for the treatment of pain. Following approval, further clinical research will shape the ability to initiate, implement, and update comprehensive patient and procedure selection paradigms. PMID:24817154

Sukul, Vishad V; Slavin, Konstantin V

2014-07-01

321

Chronic Deep Brain Stimulation of the Hypothalamic Nucleus in Wistar Rats Alters Circulatory Levels of Corticosterone and Proinflammatory Cytokines  

PubMed Central

Deep brain stimulation (DBS) is a therapeutic option for several diseases, but its effects on HPA axis activity and systemic inflammation are unknown. This study aimed to detect circulatory variations of corticosterone and cytokines levels in Wistar rats, after 21 days of DBS-at the ventrolateral part of the ventromedial hypothalamic nucleus (VMHvl), unilateral cervical vagotomy (UCVgX), or UCVgX plus DBS. We included the respective control (C) and sham (S) groups (n = 6 rats per group). DBS treated rats had higher levels of TNF-? (120%; P < 0.01) and IFN-? (305%; P < 0.001) but lower corticosterone concentration (48%; P < 0.001) than C and S. UCVgX animals showed increased corticosterone levels (154%; P < 0.001) versus C and S. UCVgX plus DBS increased IL-1? (402%; P < 0.001), IL-6 (160%; P < 0.001), and corsticosterone (178%; P < 0.001 versus 48%; P < 0.001) compared with the C and S groups. Chronic DBS at VMHvl induced a systemic inflammatory response accompanied by a decrease of HPA axis function. UCVgX rats experienced HPA axis hyperactivity as result of vagus nerve injury; however, DBS was unable to block the HPA axis hyperactivity induced by unilateral cervical vagotomy. Further studies are necessary to explore these findings and their clinical implication.

Calleja-Castillo, Juan Manuel; De La Cruz-Aguilera, Dora Luz; Manjarrez, Joaquin; Velasco-Velazquez, Marco Antonio; Morales-Espinoza, Gabriel; Moreno-Aguilar, Julia; Hernandez, Maria Eugenia; Aguirre-Cruz, Lucinda

2013-01-01

322

Subthalamic nucleus stimulation does not influence basal glucose metabolism or insulin sensitivity in patients with Parkinson's disease  

PubMed Central

Animal studies have shown that central dopamine signaling influences glucose metabolism. As a first step to show this association in an experimental setting in humans, we studied whether deep brain stimulation (DBS) of the subthalamic nucleus (STN), which modulates the basal ganglia circuitry, alters basal endogenous glucose production (EGP) or insulin sensitivity in patients with Parkinson's disease (PD). We studied 8 patients with PD treated with DBS STN, in the basal state and during a hyperinsulinemic euglycemic clamp using a stable glucose isotope, in the stimulated and non-stimulated condition. We measured EGP, hepatic insulin sensitivity, peripheral insulin sensitivity (Rd), resting energy expenditure (REE), glucoregulatory hormones, and Parkinson symptoms, using the Unified Parkinson's Disease Rating Scale (UPDRS). Basal plasma glucose and EGP did not differ between the stimulated and non-stimulated condition. Hepatic insulin sensitivity was similar in both conditions and there were no significant differences in Rd and plasma glucoregulatory hormones between DBS on and DBS off. UPDRS was significantly higher in the non-stimulated condition. DBS of the STN in patients with PD does not influence basal EGP or insulin sensitivity. These results suggest that acute modulation of the motor basal ganglia circuitry does not affect glucose metabolism in humans.

Lammers, Nicolette M.; Sondermeijer, Brigitte M.; Twickler, Th. B. (Marcel); de Bie, Rob M.; Ackermans, Mariette T.; Fliers, Eric; Schuurman, P. Richard; La Fleur, Susanne E.; Serlie, Mireille J.

2014-01-01

323

Effects of deep brain stimulation and medication on bradykinesia and muscle activation in Parkinson's disease  

Microsoft Academic Search

Summary Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and antiparkinsonian medication (Meds) have proved to be effective therapies for treating brady- kinesia in Parkinson's disease. However, it is not cur- rently known how or to what extent STN stimulation alters the control signals to agonist and antagonist mus- cles to change movement speed. Our objective was to investigate

David E. Vaillancourt; Janey Prodoehl; Leo Verhagen Metman; Roy A. Bakay; Daniel M. Corcos

2004-01-01

324

Parkin mutation and deep brain stimulation outcome.  

PubMed

Patients with parkin mutations are expected to be good candidates for deep brain stimulation (DBS) because of an excellent levodopa response and frequent occurrence of levodopa-induced dyskinesia. However, there are insufficient data on surgical outcome in patients with parkin mutations. This study aimed to compare the outcome of subthalamic nucleus DBS in patients with early-onset Parkinson's disease with and without parkin mutations. Fourteen patients with early-onset Parkinson's disease who underwent bilateral subthalamic nucleus DBS surgery were screened for parkin mutations and assessed for surgical outcomes at baseline and 2-5years after surgery. Three patients had homozygote/compound heterozygote mutations; two had single heterozygote mutations; and nine had no mutations. Patients with homozygote/compound heterozygote mutations were younger at disease onset and had longer disease duration than patients without a parkin mutation. Postoperatively, there were no significant differences in improvement on the Unified Parkinson's Disease Rating Scale part II, III, and IV, or the reduction of levodopa equivalent daily doses between patients with and without parkin mutations. The therapeutic effect of DBS did not differ between patients with and without parkin mutations. PMID:24060625

Kim, Hee Jin; Yun, Ji Young; Kim, Young-Eun; Lee, Jee-Young; Kim, Han-Joon; Kim, Ji-Young; Park, Sung Sup; Paek, Sun Ha; Jeon, Beom S

2014-01-01

325

Deep brain stimulation for Huntington's disease: long-term results of a prospective open-label study.  

PubMed

Object To date, experience of globus pallidus internus (GPi) deep brain stimulation (DBS) in the treatment of Huntington's disease (HD) has been limited to a small number of case reports. The aim of this study was to analyze long-term motor outcome of a cohort of HD patients treated with GPi DBS. Methods Seven patients with pharmacologically resistant chorea and functional impairment were included in a prospective open-label study from 2008 to 2011. The main outcome measure was the motor section of the Unified Huntington's Disease Rating Scale. The primary end point was reduction of chorea. Results Patients underwent MRI-guided bilateral GPi implantation. The median duration of follow-up was 3 years. A significant reduction of chorea was observed in all patients, with sustained therapeutic effect; the mean improvement on the chorea subscore was 58.34% at the 12-month follow-up visit (p = 0.018) and 59.8% at the 3-year visit (p = 0.040). Bradykinesia and dystonia showed a nonsignificant trend toward progressive worsening related to disease evolution and partly to DBS. The frequency of stimulation was 130 Hz for all patients. DBS-induced bradykinesia was managed by pulse-width reduction or bipolar settings. Levodopa mildly improved bradykinesia in 4 patients. Regular off-stimulation tests confirmed a persistent therapeutic effect of DBS on chorea. Conclusions GPi DBS may provide sustained chorea improvement in selected HD patients with pharmacologically resistant chorea, with transient benefit in physical aspects of quality of life before progression of behavioral and cognitive disorders. DBS therapy did not improve dystonia or bradykinesia. Further studies including quality of life measures are needed to evaluate the impact of DBS in the long-term outcome of HD. PMID:24702329

Gonzalez, Victoria; Cif, Laura; Biolsi, Brigitte; Garcia-Ptacek, Sara; Seychelles, Anne; Sanrey, Emily; Descours, Irene; Coubes, Christine; de Moura, Ana-Maria Ribeiro; Corlobe, Astrid; James, Syril; Roujeau, Thomas; Coubes, Philippe

2014-07-01

326

Deep brain stimulation in the treatment of depression  

PubMed Central

Major depressive disorder is a worldwide disease with debilitating effects on a patient's life. Common treatments include pharmacotherapy, psychotherapy, and electroconvulsive therapy. Many patients do not respond to these treatments; this has led to the investigation of alternative therapeutic modalities. Deep brain stimulation (DBS) is one of these modalities. It was first used with success for treating movement disorders and has since been extended to the treatment of psychiatric disorders. Although DBS is still an emerging treatment, promising efficacy and safety have been demonstrated in preliminary trials in patients with treatment-resistant depression (TRD). Further, neuroimaging has played a pivotal role in identifying some DBS targets and remains an important tool for evaluating the mechanism of action of this novel intervention. Preclinical animal studies have broadened knowledge about the possible mechanisms of action of DBS for TRD, Given that DBS involves neurosurgery in patients with severe psychiatric impairment, ethical questions concerning capacity to consent arise; these issues must continue to be carefully considered.

Delaloye, Sibylle; Holtzheimer, Paul E.

2014-01-01

327

Deep brain stimulation in the treatment of depression.  

PubMed

Major depressive disorder is a worldwide disease with debilitating effects on a patient's life. Common treatments include pharmacotherapy, psychotherapy, and electroconvulsive therapy. Many patients do not respond to these treatments; this has led to the investigation of alternative therapeutic modalities. Deep brain stimulation (DBS) is one of these modalities. It was first used with success for treating movement disorders and has since been extended to the treatment of psychiatric disorders. Although DBS is still an emerging treatment, promising efficacy and safety have been demonstrated in preliminary trials in patients with treatment-resistant depression (TRD). Further, neuroimaging has played a pivotal role in identifying some DBS targets and remains an important tool for evaluating the mechanism of action of this novel intervention. Preclinical animal studies have broadened knowledge about the possible mechanisms of action of DBS for TRD, Given that DBS involves neurosurgery in patients with severe psychiatric impairment, ethical questions concerning capacity to consent arise; these issues must continue to be carefully considered. PMID:24733973

Delaloye, Sibylle; Holtzheimer, Paul E

2014-03-01

328

Balancing the Brain: Resting State Networks and Deep Brain Stimulation  

PubMed Central

Over the last three decades, large numbers of patients with otherwise treatment-resistant disorders have been helped by deep brain stimulation (DBS), yet a full scientific understanding of the underlying neural mechanisms is still missing. We have previously proposed that efficacious DBS 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 networks in health and disease (such as Parkinson's) have the potential not only to increase our understanding of fundamental brain function but of how best to modulate the balance. In particular, some of the newly identified hubs and connectors within and between resting state networks could become important new targets for DBS, including potentially in neuropsychiatric disorders. At the same time, it is of essence to consider the ethical implications of this perspective.

Kringelbach, Morten L.; Green, Alexander L.; Aziz, Tipu Z.

2011-01-01

329

Neuronal Responses in the Globus Pallidus during Subthalamic Nucleus Electrical Stimulation in Normal and Parkinson's Disease Model Rats  

PubMed Central

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been widely used as a treatment for the movement disturbances caused by Parkinson's disease (PD). Despite successful application of DBS, its mechanism of therapeutic effect is not clearly understood. Because PD results from the degeneration of dopamine neurons that affect the basal ganglia (BG) network, investigation of neuronal responses of BG neurons during STN DBS can provide informative insights for the understanding of the mechanism of therapeutic effect. However, it is difficult to observe neuronal activity during DBS because of large stimulation artifacts. Here, we report the observation of neuronal activities of the globus pallidus (GP) in normal and PD model rats during electrical stimulation of the STN. A custom artifact removal technique was devised to enable monitoring of neural activity during stimulation. We investigated how GP neurons responded to STN stimulation at various stimulation frequencies (10, 50, 90 and 130 Hz). It was observed that activities of GP neurons were modulated by stimulation frequency of the STN and significantly inhibited by high frequency stimulation above 50 Hz. These findings suggest that GP neuronal activity is effectively modulated by STN stimulation and strongly dependent on the frequency of stimulation.

Ryu, Sang Baek; Bae, Eun Kyung; Kim, Jinhyung; Hwang, Yong Sup; Im, Changkyun; Chang, Jin Woo; Shin, Hyung-Cheul

2013-01-01

330

Contribution of decreased serotonin release to the antidyskinetic effects of deep brain stimulation in a rodent model of tardive dyskinesia: comparison of the subthalamic and entopeduncular nuclei.  

PubMed

Mechanisms whereby deep brain stimulation (DBS) of the subthalamic nucleus (STN) or internal globus pallidus (GPi) reduces dyskinesias remain largely unknown. Using vacuous chewing movements (VCMs) induced by chronic haloperidol as a model of tardive dyskinesia (TD) in rats, we confirmed the antidyskinetic effects of DBS applied to the STN or entopeduncular nucleus (EPN, the rodent homolog of the GPi). We conducted a series of experiments to investigate the role of serotonin (5-HT) in these effects. We found that neurotoxic lesions of the dorsal raphe nuclei (DRN) significantly decreased HAL-induced VCMs. Acute 8-OH-DPAT administration, under conditions known to suppress raphe neuronal firing, also reduced VCMs. Immediate early gene mapping using zif268 in situ hybridization revealed that STN-DBS inhibited activity of DRN and MRN neurons. Microdialysis experiments indicated that STN-DBS decreased 5-HT release in the dorsolateral caudate-putamen, an area implicated in the etiology of HAL-induced VCMs. DBS applied to the EPN also suppressed VCMs but did not alter 5-HT release or raphe neuron activation. While these findings suggested a role for decreased 5-HT release in the mechanisms of STN DBS, further microdialysis experiments showed that when the 5-HT lowering effects of STN DBS were prevented by pretreatment with fluoxetine or fenfluramine, the ability of DBS to suppress VCMs remained unaltered. These results suggest that EPN- and STN-DBS have different effects on the 5-HT system. While decreasing 5-HT function is sufficient to suppress HAL-induced VCMs, 5-HT decrease is not necessary for the beneficial motor effects of DBS in this model. PMID:22787043

Creed, Meaghan C; Hamani, Clement; Bridgman, Alanna; Fletcher, Paul J; Nobrega, José N

2012-07-11

331

Managing Parkinson's disease with continuous dopaminergic stimulation.  

PubMed

The pathophysiology of Parkinson's disease is marked by the loss of dopaminergic neurons, which leads to striatal dopaminergic deficiency. This causes resting tremor, hypokinesia, rigidity, bradykinesia, and loss of postural reflexes. Most current treatments for Parkinson's disease aim to restore striatal dopamine signaling by increasing the supply of dopamine with oral levodopa (L-dopa), stimulating dopamine receptors directly using dopamine agonists, or inhibiting the reuptake of endogenous dopamine. L-dopa is standard therapy for patients with Parkinson's disease. However, with continued treatment and disease progression, the response to oral dopaminergic drugs becomes unstable and motor fluctuations emerge, including off periods and dyskinesia. Direct duodenal-administered infusible L-dopa/carbidopa is effective for the management of refractory motor fluctuations in some patient populations. However, enteral infusions cannot mimic the function of the normal dopaminergic brain, and around-the-clock constant-rate administration carries the risk of causing refractory off periods associated with severe immobility and hyperpyrexia. Subthalamic nucleus (STN) deep brain stimulation (DBS) is also a promising treatment. DBS passes a high-frequency electrical current into the target area, mimicking the effect of lesioning the stimulated area. However, this treatment requires invasive surgery and is appropriate for a limited segment of the patient population. This supplement provides a rationale for the use of continuous dopaminergic receptor stimulation and offers guidelines on the individualization of treatment decisions, with special focus on continuous L-dopa infusion and STN DBS. Erik Wolters, MD, PhD, offers an introduction to the impact of continuous L-dopa infusion. Andrew J. Lees, MD, FRCP, provides an overview of the physiologic response to L-dopa and reviews clinical pharmacologic studies of intravenous and intraduodenal L-dopa. Jens Volkmann, MD, discusses selection criteria for STN DBS and duodenal L-dopa/carbidopa infusion. Teus van Laar, MD, PhD, and Ad Hovestadt, MD, discuss the first data from a Dutch cohort study of duodenal L-dopa/carbidopa. PMID:18408654

Wolters, Erik; Lees, Andrew J; Volkmann, Jens; van Laar, Teus; Hovestadt, Ad

2008-04-01

332

[Electrochemical polarization and corrosion of the electrodes of a self-contained electric gastrointestinal stimulator made from 12X 18H9 steel].  

PubMed

The research of a stationary and anode corrosion and of the anode/cathode polarization of electrodes, made from 12X 18H9 steel, of an autonomous electrostimulator of the gastrointestinal tract (GIT), demonstrated a practical possibility of using this steel to make electrodes for studies involving operations with the GIT aggressive medium. PMID:3495715

Agafonnikov, V F; Glushchuk, S F; Giricheva, I V; Nalesnik, O I

1987-01-01

333

Long-term follow-up of thalamic deep brain stimulation for essential tremor - patient satisfaction and mortality  

PubMed Central

Background Ventral intermediate thalamic nucleus (VIM) deep brain stimulation (DBS) is an effective treatment for tremor, but there is limited data on long-term efficacy and mortality after VIM-DBS. Here we report the analysis of patient satisfaction and mortality in all patients treated in our center 1996–2010 with VIM-DBS for essential tremor (ET). Methods Forty-six consecutive patients were included in this study. Medical records were reviewed, and a follow-up questionnaire was sent to all surviving patients. Results Seventy percent of all possible participants (26 patients) answered the questionnaire. Follow-up time for the responding patients was median 6.0 years (2–16). Median self-reported score on visual analogue scale of the initial postoperative effect on tremor was 8.5 (0.1–10), with a significant reduction to 7.4 (0–10) at follow-up (p?=?0.001). Patients reported a median score of 10 (0–10) for overall patient satisfaction with VIM-DBS treatment. Eight patients (17%) died after median 8.9 years (0.6–15) after surgery, at median age 77.4 years (70–89). One patient (2%) committed suicide seven months after the operation. Calculated standard mortality ratio among ET patients was 1.3 (CI 0.6–2.6), similar to the general population. Conclusion We found no significant increase in mortality in this cohort of VIM-DBS operated ET patients compared to the general population in Norway. The patients reported high long-term satisfaction and continuing effect of VIM-DBS on tremor even after many years. VIM-DBS therefore seems to be an effective symptomatic long-term treatment of ET. However, one patient committed suicide. Only one other suicide has previously been reported after VIM-DBS. It is therefore still unclear whether VIM-DBS increases suicide risk.

2014-01-01

334

The Ethanol-Induced Stimulation of Rat Duodenal Mucosal Bicarbonate Secretion In Vivo Is Critically Dependent on Luminal Cl–  

PubMed Central

Alcohol may induce metabolic and functional changes in gastrointestinal epithelial cells, contributing to impaired mucosal barrier function. Duodenal mucosal bicarbonate secretion (DBS) is a primary epithelial defense against gastric acid and also has an important function in maintaining the homeostasis of the juxtamucosal microenvironment. The aim in this study was to investigate the effects of the luminal perfusion of moderate concentrations of ethanol in vivo on epithelial DBS, fluid secretion and paracellular permeability. Under thiobarbiturate anesthesia, a ?30-mm segment of the proximal duodenum with an intact blood supply was perfused in situ in rats. The effects on DBS, duodenal transepithelial net fluid flux and the blood-to-lumen clearance of 51Cr-EDTA were investigated. Perfusing the duodenum with isotonic solutions of 10% or 15% ethanol-by-volume for 30 min increased DBS in a concentration-dependent manner, while the net fluid flux did not change. Pre-treatment with the CFTR inhibitor CFTRinh172 (i.p. or i.v.) did not change the secretory response to ethanol, while removing Cl? from the luminal perfusate abolished the ethanol-induced increase in DBS. The administration of hexamethonium (i.v.) but not capsazepine significantly reduced the basal net fluid flux and the ethanol-induced increase in DBS. Perfusing the duodenum with a combination of 1.0 mM HCl and 15% ethanol induced significantly greater increases in DBS than 15% ethanol or 1.0 mM HCl alone but did not influence fluid flux. Our data demonstrate that ethanol induces increases in DBS through a mechanism that is critically dependent on luminal Cl? and partly dependent on enteric neural pathways involving nicotinic receptors. Ethanol and HCl appears to stimulate DBS via the activation of different bicarbonate transporting mechanisms.

Sommansson, Anna; Wan Saudi, Wan Salman; Nylander, Olof; Sjoblom, Markus

2014-01-01

335

Impact of bilateral subthalamic stimulation on motor/cognitive functions in Parkinson's disease.  

PubMed

It is still unclear whether deep brain stimulation targeted to the bilateral subthalamic nucleus (STN-DBS) affects cognitive function in Parkinson's disease (PD). This prospective study was aimed to systemically evaluate the impact of bilateral STN-DBS on motor and cognitive functions in patients with PD. This study included totally 11 Japanese patients with medically intolerant PD. Neurological and cognitive status was precisely evaluated before and 1 year after bilateral STN-DBS, using unified Parkinson's disease rating scale (UPDRS), levodopa equivalent doses, mini-mental state examination (MMSE), Japanese adult reading test (JART), repeatable battery for the assessment of neuropsychological status (RBANS), and Wechsler adult intelligence scale-revised (WAIS-R). Preoperative RBANS and WAIS-R identified cognitive dysfunction that could not be detected by MMSE and JART. Before surgery, PD patients had significantly impaired immediate memory and attention. Motor function significantly improved 1 year after bilateral STN-DBS. Bilateral STN-DBS did not affect any score on cognitive examinations. However, postoperative improvements of total score on RBANS and performance intelligence quotient (PIQ) scores on WAIS-R were closely related to those of UPDRS part III off (R(2) = 0.61, P < 0.01; R(2) = 0.39, P < 0.05, respectively). These findings strongly suggest that bilateral STN-DBS may significantly improve cognitive function in a certain subgroup of patients whose therapeutic effects on motor function are prominent. PMID:24872253

Asahi, Takashi; Nakamichi, Naomi; Takaiwa, Akiko; Kashiwazaki, Daina; Koh, Masaki; Dougu, Nobuhiro; Takashima, Shutaro; Tanaka, Kortaro; Kuroda, Satoshi

2014-07-15

336

Deep Brain Stimulation for Early Stage Parkinson's Disease: An Illustrative Case  

PubMed Central

Objectives Subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective intervention in advanced Parkinson's Disease (PD), but its efficacy and safety in early PD are unknown. Our team is conducting a randomized pilot trial investigating DBS in early PD. This report describes one participant who received bilateral STN-DBS. Materials/Methods Thirty subjects have been randomized to either optimal drug therapy (ODT) or DBS + ODT. Microelectrode recordings from the STN and substantia nigra (SN) are collected at implantation. The Unified Parkinson's Disease Rating Scale Motor Subscale (UPDRS-III) is administered in the ON and OFF states semi-annually and neuropsychological function and quality of life are assessed annually. We describe a 54-year-old man with a two-year history of PD who was randomized to DBS + ODT and followed for two years. Results The subject showed a lower STN to SN ratio of neuronal activity than advanced PD patients, and higher firing rate than non-PD patients. The subject's ON total UPDRS and UPDRS-III scores improved during the two-year follow-up, while his OFF UPDRS-III score and levodopa equivalent daily dose (LEDD) increased. Quality of life, verbal fluency and verbal learning improved. He did not experience any serious adverse events. Conclusions This report details the first successful application of bilateral STN DBS for early stage PD during a clinical trial.

Gill, Chandler E.; Allen, Laura A.; Konrad, Peter E.; Davis, Thomas L.; Bliton, Mark J.; Finder, Stuart G.; Tramontana, Michael G.; Kao, C. Chris; Remple, Michael S.; Bradenham, Courtney H.; Charles, P. David

2011-01-01

337

Dynamics of Parkinsonian tremor during deep brain stimulation  

NASA Astrophysics Data System (ADS)

The mechanism by which chronic, high frequency, electrical deep brain stimulation (HF-DBS) suppresses tremor in Parkinson's disease is unknown. Rest tremor in subjects with Parkinson's disease receiving HF-DBS was recorded continuously throughout switching the deep brain stimulator on (at an effective frequency) and off. These data suggest that the stimulation induces a qualitative change in the dynamics, called a Hopf bifurcation, so that the stable oscillations are destabilized. We hypothesize that the periodic stimulation modifies a parameter affecting the oscillation in a time dependent way and thereby induces a Hopf bifurcation. We explore this hypothesis using a schematic network model of an oscillator interacting with periodic stimulation. The mechanism of time-dependent change of a control parameter in the model captures two aspects of the dynamics observed in the data: (1) a gradual increase in tremor amplitude when the stimulation is switched off and a gradual decrease in tremor amplitude when the stimulation is switched on and (2) a time delay in the onset and offset of the oscillations. This mechanism is consistent with these rest tremor transition data and with the idea that HF-DBS acts via the gradual change of a network property.

Titcombe, Michčle S.; Glass, Leon; Guehl, Dominique; Beuter, Anne

2001-12-01

338

Origin and Evolution of Deep Brain Stimulation  

PubMed Central

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 eighteenth century and was subsequently used by the early twentieth century, even for therapeutic purposes. In mid-twentieth 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, deep brain stimulation (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.

Sironi, Vittorio A.

2011-01-01

339

Neurogenic Hippocampal Targets of Deep Brain Stimulation  

PubMed Central

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 the limbic circuitry, the anterior thalamic nuclei (ATN), on the generation of new neurons in the dentate gyrus (DG) of the hippocampus, another component of the same circuitry. Adult hippocampal neurogenesis emerges as a strong correlate of antidepressant treatments; however, in most cases the progenitor cell population targeted by a specific treatment is not known. Using reporter mouse lines designed to quantify changes in selected classes of neural progenitors, we found that high frequency stimulation of the ATN increases symmetric divisions of a defined class of neural progenitors in the DG; this effect is later manifested as an increased number of new neurons. The affected class of neural progenitors is also affected by the antidepressant fluoxetine (Prozac) and physical exercise (running). This indicates that neurogenic stimuli of different nature can converge on the same neurogenic target in the DG. Our results also suggest that hippocampal neurogenesis may be used as a sensitive indicator of the limbic circuitry activation induced by DBS.

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

2010-01-01

340

Simulation of cortico-basal ganglia oscillations and their suppression by closed loop deep brain stimulation.  

PubMed

A new model of deep brain stimulation (DBS) is presented that integrates volume conduction effects with a neural model of pathological beta-band oscillations in the cortico-basal ganglia network. The model is used to test the clinical hypothesis that closed-loop control of the amplitude of DBS may be possible, based on the average rectified value of beta-band oscillations in the local field potential. Simulation of closed-loop high-frequency DBS was shown to yield energy savings, with the magnitude of the energy saved dependent on the strength of coupling between the subthalamic nucleus and the remainder of the cortico-basal ganglia network. When closed-loop DBS was applied to a strongly coupled cortico-basal ganglia network, the stimulation energy delivered over a 480 s period was reduced by up to 42%. Greater energy reductions were observed for weakly coupled networks, as the stimulation amplitude reduced to zero once the initial desynchronization had occurred. The results provide support for the application of closed-loop high-frequency DBS based on electrophysiological biomarkers. PMID:22695362

Grant, Peadar F; Lowery, Madeleine M

2013-07-01

341

Effects of five years of chronic STN stimulation on muscle strength and movement speed.  

PubMed

This study examined the long-term effects of chronic subthalamic nucleus (STN) deep brain stimulation (DBS) using both clinical evaluation and laboratory motor control measures. Over a 5-year time period, changes in the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS) and movement speed and strength at the ankle joint were evaluated on and off STN DBS in eight patients with Parkinson's disease (PD). Four patients were also studied at the elbow joint. Patients with PD originally received unilateral STN DBS between years 2001 and 2003. They were re-evaluated after 5 years of long-term STN DBS between years 2006-2008. At baseline (year 0) and after 5 years, patients with PD were tested off treatment and on STN DBS. In each testing condition, patients performed ballistic, single degree of freedom ankle dorsiflexion and ankle plantarflexion movements and peak velocity was calculated. Patients also performed maximal voluntary contractions at the ankle joint in both directions, and peak torque was calculated. Results showed increased motor UPDRS scores from year 0 to year 5, but STN DBS was efficacious in reducing them. In contrast to the increase in motor UPDRS scores, motor control results showed a marked improvement in peak velocity and peak torque over the 5-year time period in the off treatment condition, and STN DBS was efficacious by improving both peak velocity and peak torque. The current findings suggest that 5 years of chronic STN DBS can have beneficial effects on the motor system over the long term in discrete motor tasks in which maximal effort and maximal neural output is required. PMID:20697699

Sturman, Molly M; Vaillancourt, David E; Metman, Leo Verhagen; Bakay, Roy A E; Corcos, Daniel M

2010-09-01

342

Unexpected outcome of pallidal deep brain stimulation in a patient with Tourette syndrome.  

PubMed

A 30-year-old man underwent bilateral GPi DBS for refractory TS. His tics and obsessive-compulsive symptoms were significantly improved after chronic stimulation. At 22 months postoperatively, the implantable pulse generator had to be removed because of an infection in the infraclavicular pouch. However, we observed an unexpected effectiveness at follow-up more than 4 years after stopping the stimulation. This is the first case report of TS that showed a favorable long-term outcome after cessation of chronic GPi DBS. PMID:24898759

Dong, Sheng; Zhang, Xiaohua; Li, Jianyu; Li, Yongjie

2014-08-01

343

Modulation of human time processing by subthalamic deep brain stimulation.  

PubMed

Timing in the range of seconds referred to as interval timing is crucial for cognitive operations and conscious time processing. According to recent models of interval timing basal ganglia (BG) oscillatory loops are involved in time interval recognition. Parkinso?s disease (PD) is a typical disease of the basal ganglia that shows distortions in interval timing. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a powerful treatment of PD which modulates motor and cognitive functions depending on stimulation frequency by affecting subcortical-cortical oscillatory loops. Thus, for the understanding of BG-involvement in interval timing it is of interest whether STN-DBS can modulate timing in a frequency dependent manner by interference with oscillatory time recognition processes. We examined production and reproduction of 5 and 15 second intervals and millisecond timing in a double blind, randomised, within-subject repeated-measures design of 12 PD-patients applying no, 10-Hz- and ? 130-Hz-STN-DBS compared to healthy controls. We found under(re-)production of the 15-second interval and a significant enhancement of this under(re-)production by 10-Hz-stimulation compared to no stimulation, ? 130-Hz-STN-DBS and controls. Milliseconds timing was not affected. We provide first evidence for a frequency-specific modulatory effect of STN-DBS on interval timing. Our results corroborate the involvement of BG in general and of the STN in particular in the cognitive representation of time intervals in the range of multiple seconds. PMID:21931767

Wojtecki, Lars; Elben, Saskia; Timmermann, Lars; Reck, Christiane; Maarouf, Mohammad; Jörgens, Silke; Ploner, Markus; Südmeyer, Martin; Groiss, Stefan Jun; Sturm, Volker; Niedeggen, Michael; Schnitzler, Alfons

2011-01-01

344

Spinal Cord Stimulation Exerts Neuroprotective Effects against Experimental Parkinson's Disease  

PubMed Central

In clinical practice, deep brain stimulation (DBS) is effective for treatment of motor symptoms in Parkinson’s disease (PD). However, the mechanisms have not been understood completely. There are some reports that electrical stimulation exerts neuroprotective effects on the central nervous system diseases including cerebral ischemia, head trauma, epilepsy and PD, although there are a few reports on neuroprotective effects of spinal cord stimulation (SCS). We investigated the neuroprotective effects of high cervical SCS on PD model of rats. Adult female Sprague-Dawley rats received hour-long SCS (2, 50 or 200 Hz) with an epidural electrode at C1–2 level for 16 consecutive days. At 2 days after initial SCS, 6-hydroxydopamine (6-OHDA) was injected into the right striatum of rats. Behavioral evaluations of PD symptoms were employed, including cylinder test and amphetamine-induced rotation test performed at 1 and 2 weeks after 6-OHDA injection. Animals were subsequently euthanized for immunohistochemical investigations. In order to explore neurotrophic and growth factor upregulation induced by SCS, another cohort of rats that received 50 Hz SCS was euthanized at 1 and 2 weeks after lesion for protein assays. Behavioral tests revealed that the number of amphetamine-induced rotations decreased in SCS groups. Immunohistochemically, tyrosine hydroxylase (TH)-positive fibers in the striatum were significantly preserved in SCS groups. TH-positive neurons in the substantia nigra pars compacta were significantly preserved in 50 Hz SCS group. The level of vascular endothelial growth factor (VEGF) was upregulated by SCS at 1 week after the lesion. These results suggest that high cervical SCS exerts neuroprotection in PD model of rats, at least partially by upregulation of VEGF. SCS is supposed to suppress or delay PD progression and might become a less invasive option for PD patients, although further preclinical and clinical investigations are needed to confirm the effectiveness and safety.

Shinko, Aiko; Agari, Takashi; Kameda, Masahiro; Yasuhara, Takao; Kondo, Akihiko; Tayra, Judith Thomas; Sato, Kenichiro; Sasaki, Tatsuya; Sasada, Susumu; Takeuchi, Hayato; Wakamori, Takaaki; Borlongan, Cesario V.; Date, Isao

2014-01-01

345

Deep brain stimulation and continuous dopaminergic stimulation in advanced Parkinson's disease.  

PubMed

Patients receiving oral levodopa, the standard treatment for Parkinson's disease (PD), eventually develop motor fluctuations and dyskinesias. Treatment options for patients with these symptoms include high-frequency deep brain stimulation of the subthalamic nucleus (STN-DBS) or continuous dopaminergic stimulation (CDS). STN-DBS is the prevalent surgical therapy for PD and has shown efficacy, but behavioural disorders, including cognitive problems, depression and suicidality have been reported. CDS can be achieved with oral dopamine agonists with a long half-life, transdermal or subcutaneous delivery of dopamine agonists, or intestinal levodopa infusion. Of these, duodenal levodopa infusion appears to be the most promising option in terms of both efficacy and safety. PMID:17702631

Wolters, Erik Ch

2007-09-01

346

Subthalamic Nucleus Deep Brain Stimulation Does Not Improve Visuo-Motor Impairment in Parkinson's Disease  

PubMed Central

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 (sine/square/circle) and test-order (Test_1/Test_2). In the PD group, hand and path effects, but no test-order (on-stimulation/off-stimulation), were found. Conclusions ‘Low-level’ clinically-measured motor function responds to STN-DBS but ‘high-level’ motor and cognitive functions relating to VMC may be unresponsive to STN-DBS.

Israeli-Korn, Simon D.; Hocherman, Shraga; Hassin-Baer, Sharon; Cohen, Oren S.; Inzelberg, Rivka

2013-01-01

347

Deep brain stimulation of the subthalamic nucleus reverses oral tremor in pharmacological models of parkinsonism: interaction with the effects of adenosine A2A antagonism.  

PubMed

Deep brain stimulation (DBS) of the subthalamic nucleus is increasingly being employed as a treatment for parkinsonian symptoms, including tremor. The present studies used tremulous jaw movements, a pharmacological model of tremor in rodents, to investigate the tremorolytic effects of subthalamic DBS in rats. Subthalamic DBS reduced the tremulous jaw movements induced by the dopamine D2 family antagonist pimozide and the D1 family antagonist ecopipam, as well as the cholinomimetics pilocarpine and galantamine. The ability of DBS to suppress tremulous jaw movements was dependent on the neuroanatomical locus being stimulated (subthalamic nucleus vs. a striatal control site), as well as the frequency and intensity of stimulation used. Importantly, administration of the adenosine A2A receptor antagonist MSX-3 reduced the frequency and intensity parameters needed to attenuate tremulous jaw movements. These results have implications for the clinical use of DBS, and future studies should determine whether adenosine A2A antagonism could be used to enhance the tremorolytic efficacy of subthalamic DBS at low frequencies and intensities in human patients. PMID:23600953

Collins-Praino, Lyndsey E; Paul, Nicholas E; Ledgard, Felicia; Podurgiel, Samantha J; Kovner, Rotem; Baqi, Younis; Müller, Christa E; Senatus, Patrick B; Salamone, John D

2013-07-01

348

Chaotic Desynchronization as the Therapeutic Mechanism of Deep Brain Stimulation  

PubMed Central

High frequency deep-brain stimulation of the subthalamic nucleus (deep brain stimulation, 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 DBS and a pathophysiology of Parkinsonism in which synchrony, rather than firing rate, is the critical pathological feature.

Wilson, Charles J.; Beverlin, Bryce; Netoff, Theoden

2011-01-01

349

Deep brain stimulation of the amygdala alleviates fear conditioning-induced alterations in synaptic plasticity in the cortical-amygdala pathway and fear memory.  

PubMed

Deep brain stimulation (DBS) of the amygdala has been demonstrated to modulate hyperactivity of the amygdala, which is responsible for the symptoms of post-traumatic stress disorder (PTSD), and thus might be used for the treatment of PTSD. However, the underlying mechanism of DBS of the amygdala in the modulation of the amygdala is unclear. The present study investigated the effects of DBS of the amygdala on synaptic transmission and synaptic plasticity at cortical inputs to the amygdala, which is critical for the formation and storage of auditory fear memories, and fear memories. The results demonstrated that auditory fear conditioning increased single-pulse-evoked field excitatory postsynaptic potentials in the cortical-amygdala pathway. Furthermore, auditory fear conditioning decreased the induction of paired-pulse facilitation and long-term potentiation, two neurophysiological models for studying short-term and long-term synaptic plasticity, respectively, in the cortical-amygdala pathway. In addition, all these auditory fear conditioning-induced changes could be reversed by DBS of the amygdala. DBS of the amygdala also rescued auditory fear conditioning-induced enhancement of long-term retention of fear memory. These findings suggested that DBS of the amygdala alleviating fear conditioning-induced alterations in synaptic plasticity in the cortical-amygdala pathway and fear memory may underlie the neuromodulatory role of DBS of the amygdala in activities of the amygdala. PMID:24610492

Sui, Li; Huang, SiJia; Peng, BinBin; Ren, Jie; Tian, FuYing; Wang, Yan

2014-07-01

350

Deep Brain Stimulation of the Globus Pallidus Internus in the Parkinsonian Primate: Local Entrainment and Suppression of Low-Frequency Oscillations  

PubMed Central

Competing theories seek to account for the therapeutic effects of high-frequency deep brain stimulation (DBS) of the internal globus pallidus (GPi) for medically intractable Parkinson's disease. To investigate this question, we studied the spontaneous activity of 102 pallidal neurons during GPiDBS in two macaques rendered parkinsonian by administration of MPTP. Stimulation through macroelectrodes in the GPi (?200 ?A at 150 Hz for 30 s) reduced rigidity in one animal and increased spontaneous movement in both. Novel artifact subtraction methods allowed uninterrupted single-unit recording during stimulation. GPiDBS induced phasic (78% of cells) or sustained (22%) peristimulus changes in firing in both pallidal segments. A subset of cells responded at short latency (<2 ms) in a manner consistent with antidromic driving. Later phasic increases clustered at 3- to 5-ms latency. Stimulation-induced decreases were either phasic, clustered at 1–3 ms, or sustained, showing no peristimulus modulation. Response latency and magnitude often evolved over 30 s of stimulation, but responses were relatively stable by the end of that time. GPiDBS reduced mean firing rates modestly and only in GPi (?6.9 spikes/s). Surprisingly, GPiDBS had no net effect on the prevalence or structure of burst firing. GPiDBS did reduce the prevalence of synchronized low-frequency oscillations. Some cell pairs became synchronized instead at the frequency of stimulation. Suppression of low-frequency oscillations did not require high-frequency synchronization, however, or even the presence of a significant peristimulus response. In summary, the therapeutic effects of GPiDBS may be mediated by an abolition of low-frequency synchronized oscillations as a result of phasic driving.

McCairn, Kevin W.; Turner, Robert S.

2009-01-01

351

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

PubMed

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 (NAcc), 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 (DBS) targeted at the NAcc. This case report substantiates the assumption that the NAcc is involved in musical preference, based on the observation of direct stimulation of the accumbens with DBS. It also shows that accumbens DBS can change musical preference without habituation of its rewarding properties. PMID:24834035

Mantione, Mariska; Figee, Martijn; Denys, Damiaan

2014-01-01

352

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

PubMed Central

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 (NAcc), 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 (DBS) targeted at the NAcc. This case report substantiates the assumption that the NAcc is involved in musical preference, based on the observation of direct stimulation of the accumbens with DBS. It also shows that accumbens DBS can change musical preference without habituation of its rewarding properties.

Mantione, Mariska; Figee, Martijn; Denys, Damiaan

2014-01-01

353

Executive control in Parkinson's disease: effects of dopaminergic medication and deep brain stimulation on anti-cue keypress performance.  

PubMed

Using an anti-cue keypress task, we examined executive control in Parkinson's disease (PD) patients treated with deep brain stimulation (DBS) of the subthalamic nucleus (STN) and dopaminergic medication. Across sessions, we varied stimulation (on, off) and dopaminergic medication (on, off). Reaction time (RT) results of the PD patients and their age-matched controls showed a consistent pattern of RT costs and benefits generated by anti-cues with short and long preparation intervals, respectively. This pattern was evident in all sessions, except when DBS stimulation and medication were off. In this condition PD patients showed no RT benefits. These findings are discussed in terms of an executive control process that suppresses the automatic but inappropriate response activation generated by anti-cues. In PD this mechanism is severely compromised but it can be remediated by dopaminergic medication and DBS, suggesting an essential role of the basal ganglia in the selection and suppression of competing responses. PMID:21704125

Adam, Jos J; van Houdt, Hanna; Scholtissen, Bart; Visser-Vandewalle, Veerle; Winogrodzka, Ania; Duits, Annelien

2011-08-15

354

Successful subthalamic stimulation, but levodopa-induced dystonia, in a genetic Parkinson's disease.  

PubMed

Recently, it is under scrutiny the possibility to anticipate the stereotactic implantation of the subthalamic nucleus (STN) even in relatively mild Parkinson's disease (PD) patients with an unsatisfying response to drugs. In addition, it is debated whether levodopa (LD) and deep brain stimulation (DBS) are congruent or, instead, mutually exclusive. A 56-year-old LRRK2-positive PD patient, with 7 years of disease history, dominated by severe left resting tremor, was submitted to bilateral implantation of the subthalamic nucleus (STN). Before surgery, the combination of LD and dopamine agonists failed to handle tremor unless administered at doses, which induced undesirable adverse events. STN deep brain stimulation (DBS) abolished tremor but did not provide satisfying control of hypokinetic-rigid symptoms. The condition STIM-ON plus LD, albeit transiently beneficial, installed a painful dystonia developing slowly after 24-36 h. Only a chronic therapy combining rotigotine plus STN-DBS proved effective without side effects. This case report, based upon the surprising difference between the therapeutic response to the combination of LD and dopamine agonist (before surgery) and the combination of DBS and agonist after surgery, emphasizes how STIM and LD target different motor domains through mechanisms with differential plasticity and confirms the efficacy of STN-DBS in LRKK2 patients. PMID:22437494

Stefani, Alessandro; Marzetti, Francesco; Pierantozzi, Mariangela; Petrucci, Simona; Olivola, Enrica; Galati, Salvatore; Bassi, Mario Stampanoni; Imbriani, Paola; Valente, Enza Maria; Pastore, Francesco Saverio

2013-03-01

355

Deep brain stimulation of the anterior cingulate cortex: targeting the affective component of chronic pain.  

PubMed

Deep brain stimulation (DBS) has shown promise for relieving nociceptive and neuropathic symptoms of refractory chronic pain. We assessed the efficacy of a new target for the affective component of pain, the anterior cingulate cortex (ACC). A 49-year-old man with neuropathic pain underwent bilateral ACC DBS. Patient-reported outcome measures were collected before and 2 years after surgery using a Visual Analogue Scale, Short-Form 36 quality of life survey, McGill pain questionnaire, EuroQol-5D questionnaires (EQ-5D; Health State) and neuropsychological assessments. The patient improved with DBS. Two years after surgery, the Visual Analogue Scale decreased from 6.7 to 3.0, McGill pain questionnaire improved by 42% and EQ-5D Health State increased by 150%. Stimulating the ACC at 130 Hz, 330 µs and 3 V facilitated neuropathic pain relief. The DBS remained efficacious during the 2-year follow-up period. Affective ACC DBS can relieve chronic neuropathic pain refractory to pharmacotherapy and restore quality of life. PMID:24100411

Boccard, Sandra G J; Pereira, Erlick A C; Moir, Liz; Van Hartevelt, Tim J; Kringelbach, Morten L; FitzGerald, James J; Baker, Ian W; Green, Alexander L; Aziz, Tipu Z

2014-01-22

356

The role of serotonin in the antidyskinetic effects of deep brain stimulation: focus on antipsychotic-induced motor symptoms.  

PubMed

Treatment with the classic antipsychotic drugs (APDs), such as haloperidol (HAL), is associated with both acute and chronic motor side effects. Acutely, these drugs may induce extrapyramidal symptoms, whereas a prolonged treatment may result in tardive dyskinesia (TD). Atypical antipsychotics have a lower incidence of motor side effects, which have been partially ascribed to the antagonism of serotonin (5-HT) receptors. Although there is currently no satisfactory pharmacotherapy for TD, deep brain stimulation (DBS) has emerged as a promising therapy. However, the mechanisms underlying its effects remain largely unknown. DBS has been shown to affect several neurotransmitter systems, including 5-HT. In this review, we outline the involvement of 5-HT in the development of HAL-induced catalepsy and TD. We also discuss the evidence for DBS-induced alterations in 5-HT function and the relevance of serotonergic alterations to the antidyskinetic effects of DBS. The evidence suggests that the serotonergic mechanisms may be involved in the acute and chronic motor side effects of APDs as well as in adverse psychiatric effects that have been reported following DBS. However, the current evidence suggests that 5-HT alterations do not play an important role in the effectiveness of DBS in models of dyskinesias induced by chronic APDs. PMID:23399586

Creed, Meaghan C; Nobrega, José N

2013-01-01

357

The burden of normality: from 'chronically ill' to 'symptom free'. New ethical challenges for deep brain stimulation postoperative treatment.  

PubMed

Although an invasive medical intervention, Deep Brain Stimulation (DBS) has been regarded as an efficient and safe treatment of Parkinson's disease for the last 20 years. In terms of clinical ethics, it is worth asking whether the use of DBS may have unanticipated negative effects similar to those associated with other types of psychosurgery. Clinical studies of epileptic patients who have undergone an anterior temporal lobectomy have identified a range of side effects and complications in a number of domains: psychological, behavioural, affective and social. In many cases, patients express difficulty adjusting from being chronically ill to their new status as 'treated' or 'seizure free'. This postoperative response adjustment has been described in the literature on epilepsy as the 'Burden of Normality' (BoN) syndrome. Most of the discussion about DBS postoperative changes to self is focused on abnormal side effects caused by the intervention (ie, hypersexuality, hypomania, etc). By contrast, relatively little attention is paid to the idea that successfully 'treated' individuals might experience difficulties in adjusting to becoming 'normal'. The purpose of this paper is (1) to articulate the postoperative DBS psychosocial adjustment process in terms of the BoN syndrome, (2) to address whether the BoN syndrome illustrates that DBS treatment poses a threat to the patient's identity, and (3) to examine whether the current framework for rehabilitation after DBS procedures should be updated and take into account the BoN syndrome as a postoperative self-change response. PMID:22431560

Gilbert, Frederic

2012-07-01

358

Which approach is better: bilateral versus unilateral thalamic deep brain stimulation in patients with fragile X-associated tremor ataxia syndrome.  

PubMed

Fragile X-associated tremor ataxia syndrome (FXTAS) is a relatively recently described condition that is frequently misdiagnosed as essential tremor and then occasionally treated as such with deep brain stimulation (DBS) to the nucleus ventralis intermedius of the thalamus (Vim). Reports of ataxia worsening after bilateral Vim DBS in FXTAS patients are conflicting, and only five FXTAS patients treated with Vim DBS for intractable tremor have been reported in the literature, three of whom having undergone a bilateral procedure. We report a patient who underwent a staged Vim DBS procedure, with excellent contralateral hand tremor control and no worsening of ataxia after the first procedure, but immediate worsening of his ataxia after the second one, arguing in favor of a unilateral surgical approach for intractable tremor in FXTAS. PMID:24122741

Mehanna, R; Itin, I

2014-04-01

359

Effects of ketamine and propofol on motor evoked potentials elicited by intracranial microstimulation during deep brain stimulation  

PubMed Central

Few preclinical or clinical studies have evaluated the effect of anesthetics on motor evoked potentials (MEPs), either alone or in the presence of conditioning stimuli such as deep brain stimulation (DBS). In this study we evaluated the effects of two commonly used anesthetic agents, propofol and ketamine (KET), on MEPs elicited by intra-cortical microstimulation of the motor cortex in a rodent model with and without DBS of the dentatothalamocortical (DTC) pathway. The effects of propofol anesthesia on MEP amplitudes during DTC DBS were found to be highly dose dependent. Standard, but not high, dose propofol potentiated the facilitatory effects of 30 Hz DTC DBS on MEPs. This facilitation was sustained and phase-dependent indicating that, compared to high dose propofol, standard dose propofol has a beta-band excitatory effect on cortical networks. In contrast, KET anesthetic demonstrated a monotonic relationship with increasing frequencies of stimulation, such that the highest frequency of stimulation resulted in the greatest MEP amplitude. KET also showed phase dependency but less pronounced than standard dose propofol. The results underscore the importance of better understanding the complex effects of anesthetics on cortical networks and exogenous stimuli. Choice of anesthetic agents and dosing may significantly confound or even skew research outcomes, including experimentation in novel DBS indications and paradigms.

Furmaga, Havan; Park, Hyun-Joo; Cooperrider, Jessica; Baker, Kenneth B.; Johnson, Matthew; Gale, John T.; Machado, Andre G.

2014-01-01

360

Effects of STN and GPi Deep Brain Stimulation on Impulse Control Disorders and Dopamine Dysregulation Syndrome  

PubMed Central

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.

Moum, Sarah J.; Price, Catherine C.; Limotai, Natlada; Oyama, Genko; Ward, Herbert; Jacobson, Charles; Foote, Kelly D.; Okun, Michael S.

2012-01-01

361

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

ERIC Educational Resources Information Center

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,…

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

2008-01-01

362

Should We Consider Vim Thalamic Deep Brain Stimulation for Select Cases of Severe Refractory Dystonic Tremor  

Microsoft Academic Search

Dystonic tremor, which may present with many different clinical presentations (rhythmic oscillations, abnormal posture, pain, and\\/or a null point) has proven to be a challenge for the clinician to effectively treat. Although recent studies have demonstrated excellent outcomes in select cases following deep brain stimulation (DBS) of the internal globus pallidus, the optimal target for dystonia and particularly for dystonic

Takashi Morishita; Kelly D. Foote; Ihtsham U. Haq; Pamela Zeilman; Charles E. Jacobson; Michael S. Okun

2010-01-01

363

High frequency deep brain stimulation in the hippocampus modifies seizure characteristics in kindled rats  

Microsoft Academic Search

This experimental animal study evaluates the effect of high frequency deep brain stimulation (HFS DBS) on seizures in the Alternate Day Rapid Kindling model for temporal lobe epilepsy (TLE). The target for HFS is the hippocampus, as this structure is often presumed to be the seizure focus in human TLE. METHODS: Rats (n = 12) were fully kindled in the

T Wyckhuys; Smedt de T; P. Claeys; R Raedt; L. Waterschoot; K Vonck; Broecke van den C; C. Mabilde; L. Leybaert; W. J. Wadman; P. Boon

2007-01-01

364

Invasive Circuitry-Based Neurotherapeutics: Stereotactic Ablation and Deep Brain Stimulation for OCD  

PubMed Central

Psychiatric neurosurgery, specifically stereotactic ablation, has continued since the 1940s, mainly at a few centers in Europe and the US. Since the late 1990s, the resurgence of interest in this field has been remarkable; reports of both lesion procedures and the newer technique of deep brain stimulation (DBS) have increased rapidly. In early 2009, the US FDA granted limited humanitarian approval for DBS for otherwise intractable obsessive-compulsive disorder (OCD), the first such approval for a psychiatric illness. Several factors explain the emergence of DBS and continued small-scale use of refined lesion procedures. DBS and stereotactic ablation have been successful and widely used for movement disorders. There remains an unmet clinical need: current drug and behavioral treatments offer limited benefit to some seriously ill people. Understandings of the neurocircuitry underlying psychopathology and the response to treatment, while still works in progress, are much enhanced. Here, we review modern lesion procedures and DBS for OCD in the context of neurocircuitry. A key issue is that clinical benefit can be obtained after surgeries targeting different brain structures. This fits well with anatomical models, in which circuits connecting orbitofrontal cortex (OFC), medial prefrontal cortex (mPFC), basal ganglia, and thalamus are central to OCD pathophysiology and treatment response. As in movement disorders, dedicated interdisciplinary teams, here led by psychiatrists, are required to implement these procedures and maintain care for patients so treated. Available data, although limited, support the promise of stereotact