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1

Lead-DBS: A toolbox for deep brain stimulation electrode localizations and visualizations.  

PubMed

To determine placement of electrodes after deep brain stimulation (DBS) surgery, a novel toolbox that facilitates both reconstruction of the lead electrode trajectory and the contact placement is introduced. Using the toolbox, electrode placement can be reconstructed and visualized based on the electrode-induced artifacts on post-operative magnetic resonance (MR) or computed tomography (CT) images. Correct electrode placement is essential for efficacious treatment with DBS. Post-operative knowledge about the placement of DBS electrode contacts and trajectories is a promising tool for clinical evaluation of DBS effects and adverse effects. It may help clinicians in identifying the best stimulation contacts based on anatomical target areas and may even shorten test stimulation protocols in the future. Fifty patients that underwent DBS surgery were analyzed in this study. After normalizing the post-operative MR/CT volumes into standard Montreal Neurological Institute (MNI)-stereotactic space, electrode leads (n=104) were detected by a novel algorithm that iteratively thresholds each axial slice and isolates the centroids of the electrode artifacts within the MR/CT-images (MR only n=32, CT only n=10, MR and CT n=8). Two patients received four, the others received two quadripolar DBS leads bilaterally, summing up to a total of 120 lead localizations. In a second reconstruction step, electrode contacts along the lead trajectories were reconstructed by using templates of electrode tips that had been manually created beforehand. Reconstructions that were made by the algorithm were finally compared to manual surveys of contact localizations. The algorithm was able to robustly accomplish lead reconstructions in an automated manner in 98% of electrodes and contact reconstructions in 69% of electrodes. Using additional subsequent manual refinement of the reconstructed contact positions, 118 of 120 electrode lead and contact reconstructions could be localized using the toolbox. Taken together, the toolbox presented here allows for a precise and fast reconstruction of DBS contacts by proposing a semi-automated procedure. Reconstruction results can be directly exported to two- and three-dimensional views that show the relationship between DBS contacts and anatomical target regions. The toolbox is made available to the public in form of an open-source MATLAB repository. PMID:25498389

Horn, Andreas; Kühn, Andrea A

2015-02-15

2

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. PMID:22764359

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

2012-01-01

3

Temperature control at DBS electrodes using a heat sink: experimentally validated FEM model of DBS lead architecture.  

PubMed

There is a growing interest in the use of deep brain stimulation (DBS) 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. magnetic resonance imaging) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method (FEM) 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) it 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. PMID:22764359

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

2012-08-01

4

High frequency stimulation of the subthalamic nucleus evokes striatal dopamine release in a large animal model of human DBS neurosurgery  

PubMed Central

Subthalamic nucleus deep brain stimulation (STN DBS) ameliorates motor symptoms of Parkinson’s disease, but the precise mechanism is still unknown. Here, using a large animal (pig) model of human STN DBS neurosurgery, we utilized fast-scan cyclic voltammetry in combination with a carbon-fiber microelectrode (CFM) implanted into the striatum to monitor dopamine release evoked by electrical stimulation at a human DBS electrode (Medtronic 3389) that was stereotactically implanted into the STN using MRI and electrophysiological guidance. STN electrical stimulation elicited a stimulus time-locked increase in striatal dopamine release that was both stimulus intensity- and frequency-dependent. Intensity-dependent (1–7 V) increases in evoked dopamine release exhibited a sigmoidal pattern attaining a plateau between 5 to 7 V of stimulation, while frequency-dependent dopamine release exhibited a linear increase from 60 to 120 Hz and attained a plateau thereafter (120–240 Hz). Unlike previous rodent models of STN DBS, optimal dopamine release in the striatum of the pig was obtained with stimulation frequencies that fell well within the therapeutically effective frequency range of human DBS (120–180 Hz). These results highlight the critical importance of utilizing a large animal model that more closely represents implanted DBS electrode configurations and human neuroanatomy to study neurotransmission evoked by STN DBS. Taken together, these results support a dopamine neuronal activation hypothesis suggesting that STN DBS evokes striatal dopamine release by stimulation of nigrostriatal dopaminergic neurons. PMID:20347936

Shon, Young-Min; Lee, Kendall H.; Goerss, Stephan J.; Kim, In Yong; Kimble, Chris; Van Gompel, Jamie J.; Bennet, Kevin; Blaha, Charles D.; Chang, Su-Youne

2010-01-01

5

In vivo impedance spectroscopy of deep brain stimulation electrodes  

PubMed Central

Deep brain stimulation (DBS) represents a powerful clinical technology, but a systematic characterization of the electrical interactions between the electrode and the brain are lacking. The goal of this study was to examine the in vivo changes in DBS electrode impedance that occur after implantation and during clinically-relevant stimulation. Clinical DBS devices typically apply high-frequency voltage-controlled stimulation, and as a result the injected current is directly regulated by the impedance of the electrode-tissue interface. We monitored the impedance of scaled-down clinical DBS electrodes implanted in the thalamus and subthalamic nucleus of a rhesus macaque using electrode impedance spectroscopy (EIS) measurements ranging from 0.5 Hz to 10 kHz. To further characterize our measurements, equivalent circuit models of the electrode-tissue interface were used to quantify the role of various interface components in producing the observed electrode impedance. Following implantation, DBS electrode impedance increased and a semicircular arc was observed in the high frequency range of the EIS measurements, commonly referred to as the tissue component of the impedance. Clinically-relevant stimulation produced a rapid decrease in electrode impedance with extensive changes in the tissue component. These post-operative and stimulation-induced changes in impedance could play an important role in the observed functional effects of voltage-controlled DBS and should be considered during clinical stimulation parameter selection and chronic animal research studies. PMID:19494421

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

2010-01-01

6

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

7

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; Sørensen, Jens-Christian H

2008-02-15

8

Betting on DBS: Effects of Subthalamic Nucleus Deep Brain Stimulation on Risk Taking and Decision Making in Patients With Parkinson's Disease.  

PubMed

Objective: Concerns persist that deep brain stimulation (DBS) for Parkinson's disease (PD) increases impulsivity or induces excessive reward seeking. We report here the performance of PD patients with implanted subthalamic nucleus electrodes, with stimulation on and off, on 3 laboratory tasks of risk taking and decision making. They are compared with PD patients maintained on medication and healthy participants. Methods and Results: In the Game of Dice Task, a test of "risky" decision making, PD patients with or without DBS made highest risk bets more often and ended up with less money than did healthy participants. There was a trend for DBS stimulation to ameliorate this effect. Deal or No-Deal is an "ambiguous" decision-making task that assessed preference for risk (holding on to one's briefcase) over a "sure thing" (accepting the banker's offer). Here, DBS patients were more conservative with stimulation on than with it off. They accepted smaller offers from the banker and won less money in the DBS-on condition. Overall, the 2 PD groups won less money than did healthy participants. The Framing Paradigm assessed willingness to gamble on a fixed (unambiguous) prize depending on whether the reward was "framed" as a loss or a gain. Nonsurgical PD patients tended to be more risk-averse than were healthy participants, whereas DBS patients were more willing to gamble for gains as well as losses both on and off stimulation. Conclusions: On risky decision-making tasks, DBS patients took more risks than did healthy participants, but stimulation may temper this tendency. In contrast, in an ambiguous-risk situation, DBS patients were more risk-averse (conservative) than were healthy participants, and this tendency was greatest with stimulation. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:25486385

Brandt, Jason; Rogerson, Mark; Al-Joudi, Haya; Reckess, Gila; Shpritz, Barnett; Umeh, Chizoba C; Aljehani, Noha; Mills, Kelly; Mari, Zoltan

2014-12-01

9

Effect Transformation of the Micro Electrode Recording (MER) Data to Fast Fourier Transform (FFT) for the Main Target Nucleus Determination for STN-DBS  

PubMed Central

Introduction: Advanced PD stimulation of the STN reduces tremor, rigidity, and bradykinesia. Due to hemorrhagic complications the use of micro electrode recordings during DBS operation was still questioning for some of surgeons. But use micro electrodes were still the best choice for the positioning during surgery of DBS. Aim: The aim of the current study was to investigate the effect transformation of the micro electrode recording data to fast fourier transform for the main target nucleus determination. This process needs a multidisciplinary approach from neurosurgery, neurology and specialists on electrophysiology such as biophysics. Case report: We present the case of a 63 year-old male with medically intractable PD is focused on behalf of the surgical treatment. Patient had a 4-year history of progressively severe hand tremor on right side. The patient was successfully treated unilaterally with the STN DBS.

Kaptan, Hulagu; Ayaz, Murat; Ekmekçi, Hakan

2014-01-01

10

The VU-DBS project: integrated and computer-assisted planning, intra-operative placement, and post-operative programming of deep-brain stimulators  

NASA Astrophysics Data System (ADS)

Movement disorders affect over 5,000,000 people in the United States. Contemporary treatment of these diseases involves high-frequency stimulation through deep brain stimulation (DBS). This form of therapy is offered to patients who have begun to see failure with standard medical therapy and also to patients for which medical therapy is poorly effective. A DBS procedure involves the surgical placement, with millimetric accuracy, of an electrode in the proximity of functional areas referred to as targets. Following the surgical procedure, the implant, which is a multi-contact electrode is programmed to alleviate symptoms while minimizing side effects. Surgical placement of the electrode is difficult because targets of interest are poorly visible in current imaging modalities. Consequently, the process of implantation of a DBS electrode is an iterative procedure. An approximate target position is determined pre-operatively from the position of adjacent structures that are visible in MR images. With the patient awake, this position is then adjusted intra-operatively, which is a lengthy process. The post-surgical programming of the stimulator is an equally challenging and time consuming task, with parameter setting combinations exceeding 4000. This paper reports on the status of the Vanderbilt University DBS Project, which involves the development and clinical evaluation of a system designed to facilitate the entire process from the time of planning to the time of programming.

Dawant, Benoit M.; D'Haese, Pierre-Francois; Pallavaram, Srivatsan; Li, Rui; Yu, Hong; Spooner, John; Davis, Thomas; Kao, Chris; Konrad, Peter E.

2007-03-01

11

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. PMID:24177464

Williams, Nolan R.; Okun, Michael S.

2013-01-01

12

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. PMID:24448594

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

2014-01-01

13

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

14

Evaluation of high-perimeter electrode designs for deep brain stimulation  

NASA Astrophysics Data System (ADS)

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.

Howell, Bryan; Grill, Warren M.

2014-08-01

15

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

16

VPL-DBS on neuropathic pain rat model is effective in mechanical allodynia than cold allodynia.  

PubMed

Recently, deep brain stimulation (DBS) is widely used in various types of neurodegenerative disorders for minimal invasiveness and safety of the procedure. Deep brain stimulation is consistently applied for the treatment of patients with neuropathic pain even though the success rate is not as high as other neurodegenerative disorders. Furthermore, it is also unclear how DBS improves neuropathic pain. In this study, we investigated the role of DBS following the stimulation parameter for analgesic effect on mechanical allodynia and cold allodynia in neuropathic pain rats. We used a sciatic nerve injury model to induce neuropathic pain, and observed responses to mechanical and cold stimulation by the von Frey test and acetone test, respectively. We classified the rats into four groups: naïve (naïve, n = 10), naïve + DBS (N + DBS, n = 10), neuropathic pain (NP, n = 10), and neuropathic pain + DBS (NP + DBS, n = 10). We inserted the DBS electrode into the ventral posterolateral nucleus (VPL) into the rats (VPL-DBS). The score for mechanical allodynia was significantly decreased in NP + DBS group (p < 0.01). However, the score for cold allodynia did not significantly drop in any groups including NP + DBS group (p > 0.05). In this study, we found that the electrical stimulation of the VPL works more effectively with mechanical allodynia than cold one, and pain signal induced by mechanical stimulus and cold stimulus may be processed through different pathways in the brain. PMID:22562402

Kim, Jaehyung; Kim, Jinhyung; Min, Kyou Sik; Lee, Sung Eun; Kim, Sung June; Chang, Jin Woo

2012-12-01

17

The Role of Deep Brain Stimulation (DBS) in the Treatment of Postural Instability and Gait Disorders of Parkinson's Disease  

Microsoft Academic Search

\\u000a Postural instability and gait disorders are movement abnormalities commonly associated with advanced Parkinson's disease (PD)\\u000a that lead to loss of independence. Although the available literature varies in methodology and design, there appears to be\\u000a consensus among many studies concerning the effect of subthalamic nucleus (STN) or globus pallidus internus (GPi) deep brain\\u000a stimulation (DBS) on postural stability and gait disorders

Helen Bronte-Stewart

18

Electrical stimulation and electrode properties. Part 2: pure metal electrodes.  

PubMed

Electrical stimulation can cause significant damage to clinical electrodes as well as patient injury. In this study, the effects of stimulation on pure metal electrodes were investigated without the complexities introduced by the multiple elements that make up the clinical electrode. As with the clinical electrodes, there was significant decomposition of pure stainless steel anodes with no associated significant changes in the cathodes when stimulation employed long pulse durations. Effects of stimulation were greater when the anode and cathode were closer under constant voltage stimulation but were distance independent under constant current stimulation. High ionic content of the solution also increased the degree of damage to the anode as did the presence of chloride in the solution. Electrode composition also influenced the amount damage to the anode. Platinum and platinum-iridium electrodes showed no damage with any stimulus while stainless steel showed the lowest resistance to corrosion for direct current (DC) stimulation. Tungsten electrodes behaved very differently than stainless steel, decomposing with pulse stimulation and resisting decomposition during DC stimulation because of the formation of surface protective layers. Because platinum was able to maintain high levels of current over time, prolonged stimulation produced dramatic increases in the temperature of the solution; however, even short periods of stimulation were sufficient to produce dramatic changes in pH in the neighborhood of the electrode. PMID:21313789

Stevenson, Matthew; Baylor, Kelly; Netherton, Brett L; Stecker, Mark M

2010-12-01

19

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

20

Intraoperative X-Ray Detection and MRI-Based Quantification of Brain Shift Effects Subsequent to Implantation of the First Electrode in Bilateral Implantation of Deep Brain Stimulation Electrodes  

Microsoft Academic Search

Objective: After implantation of the first electrode in bilateral deep brain stimulation (DBS) lead implantation, brain shift effects in the target region and along the implantation trajectory of the second electrode are quantified with intraoperative magnetic resonance imaging (MRI). We investigated intraoperative X-ray imaging for its feasibility in indirect detection of brain shift. Methods: In 25 patients who underwent bilateral

Stefan Hunsche; Dieter Sauner; Mohammad Maarouf; Jörg Poggenborg; Klaus Lackner; Volker Sturm; Harald Treuer

2009-01-01

21

Anatomo-clinical atlases correlate clinical data and electrode contact coordinates: application to subthalamic deep brain stimulation.  

PubMed

For patients suffering from Parkinson's disease with severe movement disorders, functional surgery may be required when medical therapy is not effective. In Deep Brain Stimulation (DBS), electrodes are implanted within the brain to stimulate deep structures such as SubThalamic Nucleus (STN). The quality of patient surgical outcome is generally related to the accuracy of nucleus targeting during surgery. In this paper, we focused on identifying optimum sites for STN DBS by studying symptomatic motor improvement along with neuropsychological side effects. We described successive steps for constructing digital atlases gathering patient's location of electrode contacts automatically segmented from postoperative images, and clinical scores. Three motor and five neuropsychological scores were included in the study. Correlations with active contact locations were carried out using an adapted hierarchical ascendant classification. Such analysis enabled the extraction of representative clusters to determine the optimum site for therapeutic STN DBS. For each clinical score, we built an anatomo-clinical atlas representing its improvement or deterioration in relation with the anatomical location of electrodes and from a population of implanted patients. To the best of our knowledge, we reported for the first time a discrepancy between a very good motor improvement by targeting the postero-superior region of the STN and an inevitable deterioration of the categorical and phonemic fluency in the same region. Such atlases and associated analysis may help better understanding of functional mapping in deep structures and may help pre-operative decision-making process and especially targeting. PMID:23147008

Lalys, Florent; Haegelen, Claire; Mehri, Maroua; Drapier, Sophie; Vérin, Marc; Jannin, Pierre

2013-01-30

22

DBS-relevant electric fields increase hydraulic conductivity of in vitro endothelial monolayers  

NASA Astrophysics Data System (ADS)

Deep brain stimulation (DBS) achieves therapeutic outcome through generation of electric fields (EF) in the vicinity of energized electrodes. Targeted brain regions are highly vascularized, and it remains unknown if DBS electric fields modulate blood-brain barrier (BBB) function, either through electroporation of individual endothelial cells or electro-permeation of barrier tight junctions. In our study, we calculated the intensities of EF generated around energized Medtronic 3387 and 3389 DBS leads by using a finite element model. Then we designed a novel stimulation system to study the effects of such fields with DBS-relevant waveforms and intensities on bovine aortic endothelial cell (BAEC) monolayers, which were used as a basic analog for the blood-brain barrier endothelium. Following 5 min of stimulation, we observed a transient increase in endothelial hydraulic conductivity (Lp) that could be related to the disruption of the tight junctions (TJ) between cells, as suggested by zonula occludens-1 (ZO-1) protein staining. This 'electro-permeation' occurred in the absence of cell death or single cell electroporation, as indicated by propidium iodide staining and cytosolic calcein uptake. Our in vitro results, using uniform fields and BAEC monolayers, thus suggest that electro-permeation of the BBB may occur at electric field intensities below those inducing electroporation and within intensities generated near DBS electrodes. Further studies are necessary to address potential BBB disruption during clinical studies, with safety and efficacy implications.

Lopez-Quintero, S. V.; Datta, A.; Amaya, R.; Elwassif, M.; Bikson, M.; Tarbell, J. M.

2010-02-01

23

Occipital Nerve Stimulation Using a Medtronic Resume II? Electrode Array  

Microsoft Academic Search

II?,peripheral nerve \\/ spinal cord stimulator electrode for causing peripheral stimulation of the occipital nerve in the suboccipital re- gion. Initial results suggest improved stim- ulation with lower power requirements us- ing this larger electrode. The larger contact size might lessen the effect of scar forma-

Rodney L. Jones

24

Design of a stimulator ASIC for active electrode books  

Microsoft Academic Search

This paper presents the outline design of a CMOS stimulator ASIC to be embedded in implantable electrodes. The stimulator is designed to drive four tripolar output channels on an electrode “book” with independent settings on the ratio of anodic currents for each individual channel. Power and data are sent to the ASIC via five wires from a central hub unit.

Xiao Liu; Andreas Demosthenous; Anne Vanhoestenberghe; Nick Donaldson

2010-01-01

25

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. PMID:24672437

Chiken, Satomi; Nambu, Atsushi

2014-01-01

26

Electrical stimulation causes rapid changes in electrode impedance of cell-covered electrodes  

PubMed Central

Animal and clinical observations of a reduction in electrode impedance following electrical stimulation encouraged the development of an in vitro model of the electrode-tissue interface. This model was used previously to show an increase in impedance with cell and protein cover over electrodes. In this paper, the model was used to assess the changes in electrode impedance and cell cover following application of a charge-balanced biphasic current pulse train. Following stimulation, a large and rapid drop in total impedance (Zt) and access resistance (Ra) occurred. The magnitude of this impedance change was dependent on the current amplitude used, with a linear relationship determined between Ra and the resulting cell cover over the electrodes. The changes in impedance due to stimulation were shown to be transitory, with impedance returning to pre-stimulation levels several hours after cessation of stimulation. A loss of cells over the electrode surface was observed immediately after stimulation suggesting that the level of stimulation applied was creating localised changes to cell adhesion. Similar changes in electrode impedance were observed for in vivo and in vitro work, thus helping to verify the in vitro model, although the underlying mechanisms may differ. A change in the porosity of the cellular layer was proposed to explain the alterations in electrode impedance in vitro. These in vitro studies provide insight into the possible mechanisms occurring at the electrode-tissue interface in association with electrical stimulation. PMID:21572219

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

2011-01-01

27

Patient-specific models and simulations of deep brain stimulation for postoperative follow-up  

Microsoft Academic Search

\\u000a Deep brain stimulation (DBS) is an established treatment for Parkinson’s disease (PD). The success of DBS is highly dependent\\u000a on electrode location and electrical parameter settings. In this study patient-specific computer models of DBS were used for\\u000a postoperative follow-up in three PD patients who suffered from stimulation induced hypomania, dysarthria, and uncontrollable\\u000a laughter respectively. The overall aim of the study

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

28

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. PMID:23874290

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

2013-01-01

29

Electrical stimulation as therapy for neurological disorders  

Microsoft Academic Search

This article outlines the basics of implantable neurological stimulators (INSs) and electrodes. Mechanisms of neural stimulation relevant to the clinician are reviewed, including the activating function, strength-duration relationship, and strength-distance relationship as well as safety considerations including safe charge and charge density levels. Clinical examples are taken from spinal cord stimulation (SCS) for pain and deep brain stimulation (DBS) for

ROY L. TESTERMAN; MARK T. RISE; PAUL H. STYPULKOWSKI

2006-01-01

30

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

31

Heating Induced near Deep Brain Stimulation Lead Electrodes during Magnetic Resonance Imaging with a 3T Transceive Volume Head Coil  

PubMed Central

Heating induced near deep brain stimulation (DBS) lead electrodes during MRI with a 3T 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 SAR of 3.16 W/kg. Temperatures were measured using fluoroptic probes at the scalp, first and second electrodes from the distal lead tip, and 6 mm distal from electrode 1 (T6mm). The heating was modeled using the maximum T6mm and imaged using a proton resonance frequency shift based MR thermometry method. Results showed that the heating was significantly reduced when the extra-cranial lead was placed in the longitudinal direction compared to the other placements (peak temperature change = 1.5–3.2 °C vs 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

2012-01-01

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

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

34

A Preliminary Report on Disordered Speech with Deep Brain Stimulation in Individuals with Parkinson's Disease  

PubMed Central

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has proven effective in treating the major motor symptoms of advanced Parkinson's disease (PD). The aim of this study was to learn which laryngeal and articulatory acoustic features changed in patients who were reported to have worse speech with stimulation. Six volunteers with PD who had bilateral STN electrodes were recorded with DBS turned on or off. Perceptual ratings reflected poorer speech performance with DBS on. Acoustic measures of articulation (corner vowel formants, diphthong slopes, and a spirantization index) and phonation (perturbation, long-term average spectrum) as well as verbal fluency scores showed mixed results with DBS. Some speakers improved while others became worse on individual measures. The magnitude of DBS effects was not predictable based on the patients' demographic characteristics. Future research involving adjustments to stimulator settings or electrode placement may be beneficial in limiting the negative effects of DBS on speech. PMID:22046577

Dromey, Christopher; Bjarnason, Suzy

2011-01-01

35

Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools  

Microsoft Academic Search

Deep brain stimulation (DBS) has become increasingly important for the treatment and relief of neurological disorders such\\u000a as Parkinson’s disease, tremor, dystonia and psychiatric illness. As DBS implantations and any other stereotactic and functional\\u000a surgical procedure require accurate, precise and safe targeting of the brain structure, the technical aids for preoperative\\u000a planning, intervention and postoperative follow-up have become increasingly important.

Simone Hemm; Karin Wårdell

2010-01-01

36

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

37

MRI-Based Multiscale Model for Electromagnetic Analysis in the Human Head with Implanted DBS  

PubMed Central

Deep brain stimulation (DBS) is an established procedure for the treatment of movement and affective disorders. Patients with DBS may benefit from magnetic resonance imaging (MRI) to evaluate injuries or comorbidities. However, the MRI radio-frequency (RF) energy may cause excessive tissue heating particularly near the electrode. This paper studies how the accuracy of numerical modeling of the RF field inside a DBS patient varies with spatial resolution and corresponding anatomical detail of the volume surrounding the electrodes. A multiscale model (MS) was created by an atlas-based segmentation using a 1?mm3 head model (mRes) refined in the basal ganglia by a 200??m2 ex-vivo dataset. Four DBS electrodes targeting the left globus pallidus internus were modeled. Electromagnetic simulations at 128?MHz showed that the peak of the electric field of the MS doubled (18.7?kV/m versus 9.33?kV/m) and shifted 6.4?mm compared to the mRes model. Additionally, the MS had a sixfold increase over the mRes model in peak-specific absorption rate (SAR of 43.9?kW/kg versus 7?kW/kg). The results suggest that submillimetric resolution and improved anatomical detail in the model may increase the accuracy of computed electric field and local SAR around the tip of the implant. PMID:23956789

Iacono, Maria Ida; Makris, Nikos; Mainardi, Luca; Angelone, Leonardo M.; Bonmassar, Giorgio

2013-01-01

38

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

39

EMG monitoring of stimulating electrode position in implantation of subcutaneous peroneal stimulators.  

PubMed

Implantation of subcutaneous peroneal stimulators requires careful positioning to obtain a good response. With the patient lying down during the surgical procedure, ankle dorsal flexion was not always satisfactory during gait. Instead of dorsal flexion the stimulus could give an excessive eversion or a coactivation of ankle antagonists. To select the correct electrode position, the responses to single stimulation pulses were monitored in the tibialis anterior, peroneus longus and triceps surae muscles by surface EMG electrodes. With the patient standing, a strong contraction of the anterior tibial muscle without excessive contraction of the peroneus longus muscle was first determined by surface stimulation. The EMG responses were then recorded with the patient lying in the position required for implantation. The records were used as a guideline during surgery, during which positioning of the electrodes was monitored by the EMG responses. The method, tested on 2 healthy adults and 13 patients, resulted in reliable positioning of the stimulating electrodes. PMID:3261038

Malezic, M; Gregoric, M; Kljaji?, E; A?imovi?-Janezic, R

1988-01-01

40

[Deep brain stimulation--the newest physical method of treatment of depression].  

PubMed

The deep brain stimulation DBS is the newest physical method of the treatment of depressive disorders. When applying of this technique in neurological illnesses (e.g., Parkinson's disease), mood changes were observed. In 2005, Helen Mayberg et al. used DBS in the therapy of the depression for the first time. Stimulating electrodes were placed in Brodmann areas 25. In the period of some past years, only about 30-40 patients with refractory depression have undergone DBS treatment. Numerous problems connected with applying DBS in patients with psychiatric disorders are described in the paper. PMID:20672511

Zyss, Tomasz; Zieba, Andrzej; Hese, Robert T; Dudek, Dominika; Grabski, Bartosz

2010-01-01

41

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

E-print Network

(MEG) signals and subcortical local field potentials (LFP) in a Parkinson's disease (PD) patient. Introduction Deep brain stimulation (DBS) is a method for treatment of some neurological and psychiatric- electrodes. DBS has been especially effective for treating symptoms of Parkinson's disease (PD) and dystonia

Penny, Will

42

Recruitment characteristics of nerve fascicles stimulated by a multigroove electrode  

Microsoft Academic Search

The recruitment characteristics of fascicle-selective nerve stimulation by a multigroove electrode have been investigated both theoretically and in acute experiments. A three-dimensional (3-D) volume conductor model of fascicles in a multigroove device and a model of myelinated nerve fiber stimulation were used to calculate threshold stimuli of nerve fibers in these fascicles. After their exposition, fascicles from rat sciatic nerve

Paul Koole; Jan Holsheimer; Johannes J. Struijk; Anton J. Verloop

1997-01-01

43

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 elec- trode-tissue system, as measured using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Silicon, mi- cromachined probes with multiple iridium oxide stimulating electrodes (400-1600 m ) were implanted in guinea pig cortex. A 10-17 day post-operative recovery period was followed by five days

James D. Weiland; David J. Anderson

2000-01-01

44

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

45

Alexithymia in patients with Parkinson’s disease treated with DBS of the subthalamic nucleus: a case-control study  

PubMed Central

Objectives: To evaluate the effect of deep brain stimulation of the subthalamic nucleus (STN-DBS) on alexithymia, a deficit in affective regulation, comparing patients with Parkinson’s disease (PD) submitted to STN-DBS (DBS group) to PD patients not yet treated with STN-DBS (pre-DBS group) and to healthy participants (C group). Methods: We recruited 27 consecutive STN-DBS PD patients, 38 consecutive pre-DBS patients and 27 healthy participants. Patients were assessed for alexithymia (Toronto Alexithymia Scale), depression, [beck depression inventory (BDI)], and cognitive functions (reasoning, memory, attentional, and executive tests). Results: The DBS patients performed worse than the pre-DBS patients in the corsi’s block-tapping test, in the phonemic fluency task and in the Frontal Assessment Battery. Around 30% of DBS (29.6%) and pre-DBS (31.6%) patients resulted alexithymic, compared with 14.8% in the C group. The results pointed out significantly higher alexithymia scores in both the DBS and pre-DBS groups compared with the C group, while no difference emerged between the DBS and pre-DBS groups. Pre-DBS group showed a significantly higher BDI score than the C group, while DBS group did not. Conclusion: Although the results suggest that STN-DBS does not affect alexithymia, both the DBS and pre-DBS patients reported higher prevalence (about 30%) of alexithymia than did healthy subjects (14.8%). PMID:25352821

Castelli, Lorys; Tonello, Debora; Rizzi, Laura; Zibetti, Maurizio; Lanotte, Michele; Lopiano, Leonardo

2014-01-01

46

Electrodeposited iridium oxide for neural stimulation and recording electrodes  

Microsoft Academic Search

Iridium oxide films formed by electrodeposition onto noniridium metal substrates are compared with activated iridium oxide films (AIROFs) as a low impedance, high charge capacity coating for neural stimulation and recording electrodes. The electrodeposited iridium oxide films (EIROFs) were deposited on Au, Pt, PtIr, and 316 LVM stainless steel substrates from a solution of IrCl 4, oxalic acid, and K

Ross D. Meyer; Stuart F. Cogan; Trung H. Nguyen; R. David Rauh

2001-01-01

47

Characterization of electrical stimulation electrodes for cardiac tissue engineering.  

PubMed

Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. The goal of this study was to assess the conditions of electrical stimulation with respect to the electrode geometry, material properties and charge-transfer characteristics at the electrode-electrolyte interface. We compared various biocompatible materials, including nanoporous carbon, stainless steel, titanium and titanium nitride, for use in cardiac tissue engineering bioreactors. The faradaic and non-faradaic charge transfer mechanisms were assessed by electrochemical impedance spectroscopy (EIS), studying current injection characteristics, and examining surface properties of electrodes with scanning electron microscopy. Carbon electrodes were found to have the best current injection characteristics. However, these electrodes require careful handling because of their limited mechanical strength. The efficacy of various electrodes for use in 2-D and 3-D cardiac tissue engineering systems with neonatal rat cardiomyocytes is being determined by assessing cell viability, amplitude of contractions, excitation thresholds, maximum capture rate, and tissue morphology. PMID:17946862

Tandon, Nina; Cannizzaro, Chris; Figallo, Elisa; Voldman, Joel; Vunjak-Novakovic, Gordana

2006-01-01

48

MRI-Related Heating near Deep Brain Stimulation Electrodes: More Data Are Needed  

Microsoft Academic Search

Magnetic resonance imaging (MRI) of patients with implanted deep brain stimulation (DBS) devices poses a challenge for healthcare providers. As a consequence of safety concerns about magnetic field interactions with the device, induced electrical currents and thermal damage due to radiofrequency heating, a number of stringent guidelines have been proposed by the device manufacturer. Very few detailed investigations of these

Akshay A. Gupte; Devashish Shrivastava; Maggie A. Spaniol; Aviva Abosch

2011-01-01

49

Micro-Reaction Chamber Electrodes for Neural Stimulation and Recording  

PubMed Central

Biocompatible electrodes with smaller geometric area are preferred to improve the selectivity of the neural recording and stimulation applications. We introduce the concept of a micro-reaction chamber (µRC) in which a volume within the electrode back plane is used to confine and sequester the electrochemical reactions used for charge passage. The µRC electrode design helps decrease impedance and improves the charge storage capacity without altering the geometry of the active site. Here we demonstrate that µRC electrodes fabricated from 50 µm diameter microwire have significantly improved charge storage capacity and lowered impedance at physiologically relevant frequencies in phosphate buffered saline solution compared with other designs. PMID:22254394

Shanmugasundaram, Balaji; Gluckman, Bruce J.

2012-01-01

50

Access resistance of stimulation electrodes as a function of electrode proximity to the retina  

NASA Astrophysics Data System (ADS)

Objective. Epiretinal prostheses seek to effectively stimulate the retina by positioning electrode arrays close to its surface so current pulses generate narrow retinal electric fields. Our objective was to evaluate the use of the electrical impedance of insulated platinum electrodes as a measure of the proximity of insulated platinum electrodes to the inner surface of the retina. Approach. We examined the impedance of platinum disk electrodes, 0.25 mm in diameter, insulated with two widths (0.8 and 1.6 mm outer diameter) of transparent fluoropolymer in a rabbit retinal eyecup preparation. Optical coherence tomography measured the electrode’s proximity to the retinal surface which was correlated with changes in the voltage waveform at the electrode. Electrode impedance changes during retinal deformation were also studied. Main results. When the 1.6 mm diameter insulated electrodes advanced towards the retinal surface from 1000 ?m, their voltage step at current pulse onset increased, reflecting an access resistance increase of 3880 ± 630 ?, with the 50% midpoint averaging 30 ?m, while thin 0.8 mm insulated electrode advancement showed an access resistance increase 50% midpoint averaging 16 ?m. Using impedance spectroscopy, electrode–retina proximity differences were seen in the 1.6 mm insulated electrode impedance modulus between 1 and 100 kHz and the waveform phase angle at 0.3–10 kHz, while thin 0.8 mm insulated electrode advancement produced smaller impedance modulus changes with retinal proximity between 3 and 100 kHz. These impedance changes with retinal proximity may reflect different sized zones of eye wall being coupled in series with the insulated platinum electrode. Significance. The proximity of stimulus electrodes to neural tissue in fluid-filled spaces can be estimated from access resistance changes in the stimulus pulse waveform. Because many prosthetic devices allow back telemetry communication of the stimulus electrode waveform, it is possible these series resistance increases observed with retinal proximity could be used as a metric of stimulus electrode placement.

Majdi, Joseph A.; Minnikanti, Saugandhika; Peixoto, Nathalia; Agrawal, Anant; Cohen, Ethan D.

2015-02-01

51

Access resistance of stimulation electrodes as a function of electrode proximity to the retina.  

PubMed

Objective. Epiretinal prostheses seek to effectively stimulate the retina by positioning electrode arrays close to its surface so current pulses generate narrow retinal electric fields. Our objective was to evaluate the use of the electrical impedance of insulated platinum electrodes as a measure of the proximity of insulated platinum electrodes to the inner surface of the retina. Approach. We examined the impedance of platinum disk electrodes, 0.25 mm in diameter, insulated with two widths (0.8 and 1.6 mm outer diameter) of transparent fluoropolymer in a rabbit retinal eyecup preparation. Optical coherence tomography measured the electrode's proximity to the retinal surface which was correlated with changes in the voltage waveform at the electrode. Electrode impedance changes during retinal deformation were also studied. Main results. When the 1.6 mm diameter insulated electrodes advanced towards the retinal surface from 1000 ?m, their voltage step at current pulse onset increased, reflecting an access resistance increase of 3880 ± 630 ?, with the 50% midpoint averaging 30 ?m, while thin 0.8 mm insulated electrode advancement showed an access resistance increase 50% midpoint averaging 16 ?m. Using impedance spectroscopy, electrode-retina proximity differences were seen in the 1.6 mm insulated electrode impedance modulus between 1 and 100 kHz and the waveform phase angle at 0.3-10 kHz, while thin 0.8 mm insulated electrode advancement produced smaller impedance modulus changes with retinal proximity between 3 and 100 kHz. These impedance changes with retinal proximity may reflect different sized zones of eye wall being coupled in series with the insulated platinum electrode. Significance. The proximity of stimulus electrodes to neural tissue in fluid-filled spaces can be estimated from access resistance changes in the stimulus pulse waveform. Because many prosthetic devices allow back telemetry communication of the stimulus electrode waveform, it is possible these series resistance increases observed with retinal proximity could be used as a metric of stimulus electrode placement. PMID:25474329

Majdi, Joseph A; Minnikanti, Saugandhika; Peixoto, Nathalia; Agrawal, Anant; Cohen, Ethan D

2015-02-01

52

Spinal stimulator peri-electrode masses: case report.  

PubMed

The authors describe a case of delayed spastic quadriparesis caused by a peri-electrode mass following the implantation of a minimally invasive percutaneous spinal cord stimulator (SCS). Prior reports with paddle-type electrodes are reviewed, and a detailed histological and pathophysiological comparison with the present case is made. The patient developed tolerance to a cervical percutaneous SCS 4 months after implantation, followed by the onset of spastic quadriparesis 9 months after implantation. The stimulator was removed, and contrast-enhanced MRI revealed an enhancing epidural mass where the system had been placed, with severe spinal cord compression. Decompression was carried out, and the patient experienced neurological improvement. Pathological examination revealed fibrotic tissue with granulomatous and multinucleated giant cell reactions. No evidence of infection or hemorrhage was found. Professionals treating patients with SCSs or contemplating their insertion should be aware of this delayed complication and associated risk factors. PMID:25380541

Scranton, Robert A; Skaribas, Ioannis M; Simpson, Richard K

2015-01-01

53

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

54

Effects of different stimulation parameters on the antidepressant-like response of medial prefrontal cortex deep brain stimulation in rats.  

PubMed

Subcallosal cingulate gyrus (SCG) deep brain stimulation (DBS) is currently being investigated as a treatment for major depression. Despite the encouraging findings of the initial clinical series, several questions remain unanswered, including the most effective stimulation parameters (i.e., current intensity and frequency) and whether unilateral stimulation is also beneficial. We have recently found that some of the effects of SCG DBS could be modeled by stimulating the ventromedial prefrontal cortex (vmPFC) of rats undergoing the forced swim test (FST). Here we investigate whether changes in a number of DBS parameters, including electrode placement, influence outcome in this paradigm. Overall, we found that the antidepressant-like effects of DBS varied as a function of stimulation settings and target. The strongest response was observed with a current intensity of 200 microA, followed by 100 microA, and 300 microA. In contrast, 400 microA produced no effect. Using 200 microA, a frequency of 130 Hz was more effective than 20 Hz. An intriguing finding was that left unilateral stimulation was as effective as bilateral DBS. When different targets within the vmPFC were considered, a significant antidepressant-like response was observed after PL DBS, whereas IL stimulation was associated with a non-significant reduction in immobility scores. In summary, vmPFC DBS at high frequency and moderate intensity led to a maximal response in the FST. PMID:20096858

Hamani, Clement; Diwan, Mustansir; Isabella, Silvia; Lozano, Andres M; Nobrega, José N

2010-08-01

55

Selection of the optimal microelectrode during DBS surgery in Parkinson's patients  

E-print Network

Abstract. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is effective treatment of ParkinsonSelection of the optimal microelectrode during DBS surgery in Parkinson's patients Konrad: Parkinson's Disease, DBS, STN, Wavelet, Filtering, PCA, FFT, Spike detection, Spike discrimination, Spike

Ras, Zbigniew W.

56

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. PMID:19936312

Wei, Xuefeng F.; Grill, Warren M.

2009-01-01

57

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

PubMed Central

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

2011-01-01

58

Seven-electrode EER stimulator-monitor for ambulatory monkeys.  

PubMed

An electrical evoked response (EER) stimulator-monitor for ambulatory monkeys is described. Seven time-multiplexed electrodes are used. The unit switches between stimulus and monitor modes at a 100-Hz rate. In the stimulus mode, 3.5 V peak, 0.45-ms pulses are applied at a 100-Hz rate to any electrode selected by means of toggle switches on a remote control panel. In the monitor mode, low-frequency -3 dB cutoff occurs at 0.2 Hz. A 20-MHz carrier is used as a local superheterodyne oscillator during the stimulus period, and as an FM transmitter during the monitor period. Three mercury cells supply 4 V at 10 mA. The unit weighs 80 g. It is 5.7 x 5 x 2.5 cm in size. PMID:6783145

Deutsch, S

1980-01-01

59

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

60

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. PMID:24502253

2014-01-01

61

Anatomical Targets Associated with Abrupt versus Gradual Washout of Subthalamic Deep Brain Stimulation Effects on Bradykinesia  

PubMed Central

The subthalamic nucleus (STN) is a common anatomical target for deep brain stimulation (DBS) for the treatment of Parkinson’s disease. However, the effects of stimulation may spread beyond the STN. Ongoing research aims to identify nearby anatomical structures where DBS-induced effects could be associated with therapeutic improvement or side effects. We previously found that DBS lead location determines the rate – abrupt vs. gradual – with which therapeutic effect washes out after stimulation is stopped. Those results suggested that electrical current spreads from the electrodes to two spatially distinct stimulation targets associated with different washout rates. In order to identify these targets we used computational models to predict the volumes of tissue activated during DBS in 14 Parkinson’s patients from that study. We then coregistered each patient with a stereotaxic atlas and generated a probabilistic stimulation atlas to obtain a 3-dimensional representation of regions where stimulation was associated with abrupt vs. gradual washout. We found that the therapeutic effect which washed out gradually was associated with stimulation of the zona incerta and fields of Forel, whereas abruptly-disappearing therapeutic effect was associated with stimulation of STN itself. This supports the idea that multiple DBS targets exist and that current spread from one electrode may activate more than one of them in a given patient, producing a combination of effects which vary according to electrode location and stimulation settings. PMID:25098453

Cooper, Scott E.; Driesslein, Klaus G.; Noecker, Angela M.; McIntyre, Cameron C.; Machado, Andre M.; Butson, Christopher R.

2014-01-01

62

Deep Brain Stimulation: Technology at the Cutting Edge  

PubMed Central

Deep brain stimulation (DBS) surgery has been performed in over 75,000 people worldwide, and has been shown to be an effective treatment for Parkinson's disease, tremor, dystonia, epilepsy, depression, Tourette's syndrome, and obsessive compulsive disorder. We review current and emerging evidence for the role of DBS in the management of a range of neurological and psychiatric conditions, and discuss the technical and practical aspects of performing DBS surgery. In the future, evolution of DBS technology may depend on several key areas, including better scientific understanding of its underlying mechanism of action, advances in high-spatial resolution imaging and development of novel electrophysiological and neurotransmitter microsensor systems. Such developments could form the basis of an intelligent closed-loop DBS system with feedback-guided neuromodulation to optimize both electrode placement and therapeutic efficacy. PMID:21264197

Shah, Rahul S.; Chang, Su-Youne; Min, Hoon-Ki; Cho, Zang-Hee; Blaha, Charles D.

2010-01-01

63

External trial deep brain stimulation device for the application of desynchronizing stimulation techniques  

NASA Astrophysics Data System (ADS)

In the past decade deep brain stimulation (DBS)—the application of electrical stimulation to specific target structures via implanted depth electrodes—has become the standard treatment for medically refractory Parkinson's disease and essential tremor. These diseases are characterized by pathological synchronized neuronal activity in particular brain areas. We present an external trial DBS device capable of administering effectively desynchronizing stimulation techniques developed with methods from nonlinear dynamics and statistical physics according to a model-based approach. These techniques exploit either stochastic phase resetting principles or complex delayed-feedback mechanisms. We explain how these methods are implemented into a safe and user-friendly device.

Hauptmann, C.; Roulet, J.-C.; Niederhauser, J. J.; Döll, W.; Kirlangic, M. E.; Lysyansky, B.; Krachkovskyi, V.; Bhatti, M. A.; Barnikol, U. B.; Sasse, L.; Bührle, C. P.; Speckmann, E.-J.; Götz, M.; Sturm, V.; Freund, H.-J.; Schnell, U.; Tass, P. A.

2009-12-01

64

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

65

Multimodal Localization of Electrodes in Deep Brain Stimulation: Comparison of Stereotactic CT and MRI with Teleradiography  

Microsoft Academic Search

Objective: In cross-sectional imaging, like CT or MRI, electrodes for deep brain stimulation are visualized by an artifact, which can differ from the real physical size of the electrode and even have an asymmetric appearance on MRI. The accuracy of such artifact-based estimation of the real position of the electrode using CT or MRI is investigated here. Stereotactic teleradiography was

Dieter Sauner; Matthias Runge; Jörg Poggenborg; Mohammad Maarouf; Volker Sturm; Harald Treuer; Stefan Hunsche

2010-01-01

66

A simulation study: effect of the inter-electrode distance, electrode size and shape in transcutaneous electrical stimulation.  

PubMed

Transcutaneous Electrical Stimulation (TES) has been used widely to recover motor functions in neurologically impaired individuals by artificially activating skeletal muscles using superficial electrodes. Some simulation studies have investigated the percentage of fibers activated in denervated skeletal muscles, the comfort and selectivity, and the influence of fat thickness in the case of obese people, to optimize the inter-electrode distance and electrode size. However, the effect of the inter-electrode distance, electrode shape and electrode size might be further analyzed using the selectivity, activation depth and activation volume. In this regard, we developed a 3D multi-layer (skin, fat, muscle, and nerve) thigh model coupled with a mammalian nerve model using a finite element method for optimization of TES therapy. Different evaluation indices (motor threshold, activation depth, selectivity and activation volume) were inspected to compare different TES parameters in terms of nerve activation. The simulation results agreed with experimental data and new insights were obtained: selectivity is better in small electrodes; nevertheless, in high current stimulation, small electrodes and large electrodes have similar selectivity. PMID:23366700

Gomez-Tames, Jose D; Gonzalez, Jose; Yu, Wenwei

2012-01-01

67

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. PMID:21603182

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

2011-01-01

68

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

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

69

Cognition and Mood in Parkinson Disease in STN versus GPi DBS: The COMPARE Trial  

PubMed Central

Objective There is a paucity of level-one evidence comparing STN and GPi DBS. Our aim in this prospective blinded randomized trial was to compare the cognitive and mood effects of unilateral subthalamic nucleus (STN) vs. unilateral globus pallidus interna (GPi) deep brain stimulation (DBS) in patients with Parkinson disease (PD). Methods Fifty-two subjects with moderate-to-advanced PD were randomized to either unilateral STN or GPi DBS. Right or alternatively left sided stimulation was chosen to address the side of the body with the most bothersome symptoms. The co-primary outcome measures were the change in the 8 subscales of the Visual Analog Mood Scale (VAMS), and the change in the 2 versions of verbal fluency (i.e. semantic and letter), at 7 months post-DBS in the optimal setting compared to the pre-DBS state. In addition, at 7 months post-DBS, after subjects underwent initial evaluation off medications and on optimized DBS therapy, they were tested in four randomized and counterbalanced conditions (optimal DBS, ventral DBS, dorsal DBS, and off DBS) while remaining off medication. Secondary outcome measures then compared the differences in the VAMS items and verbal fluency subscales within the 4 DBS conditions at 7 months, and the change in the VAMS items and verbal fluency subscales from the pre-DBS state to the other 3 DBS conditions (ventral, dorsal and off ) at 7 months. Results Forty-five subjects (23 GPi and 22 STN) completed the protocol. The study revealed no significant difference between STN and GPi DBS in the change of co-primary mood and cognitive outcomes from pre- to post-DBS in the optimal setting (Hotelling's T2 test: p=0.16 and 0.08 respectively). When comparing the 4 DBS conditions at 7 months, subjects in both targets were less “happy”, less “energetic” and more “confused” when stimulated ventrally to the optimal stimulation site. When comparing the other 3 DBS conditions (ventral, dorsal and off DBS) to the pre-DBS state, the STN group showed a larger deterioration of letter verbal fluency scores than the GPi group, especially in the off DBS state. A 12-point mean improvement in the UPDRS motor subscale was seen post DBS, but there was no significant difference between targets. Interpretations There were no significant differences in in the co-primary outcome measures of mood and cognition between STN and GPi in the optimal DBS state.. However, adverse mood effects were noted when stimulating ventrally to the optimal site in both targets. Furthermore, a worsening for letter verbal fluency was noted in the 3 non-optimal post-DBS states in the STN target only. The persistence of deterioration in verbal fluency in the off DBS state at 7 months is, suggestive of a surgical rather than a stimulation-induced effect at the STN target. STN and GPi DBS resulted in similar motor improvement. PMID:19288469

Okun, Michael S.; Fernandez, Hubert H.; Wu, Samuel S.; Kirsch-Darrow, Lindsey; Bowers, Dawn; Bova, Frank; Suelter, Michele; Jacobson, Charles E.; Wang, Xinping; Gordon, Clifford W.; Zeilman, Pam; Romrell, Janet; Martin, Pam; Ward, Herbert; Rodriguez, Ramon L.; Foote, Kelly D.

2009-01-01

70

PEDOT–CNT coated electrodes stimulate retinal neurons at low voltage amplitudes and low charge densities  

NASA Astrophysics Data System (ADS)

Objective. The aim of this study was to compare two different microelectrode materials—the conductive polymer composite poly-3,4-ethylenedioxythiophene (PEDOT)–carbon nanotube(CNT) and titanium nitride (TiN)—at activating spikes in retinal ganglion cells in whole mount rat retina through stimulation of the local retinal network. Stimulation efficacy of the microelectrodes was analyzed by comparing voltage, current and transferred charge at stimulation threshold. Approach. Retinal ganglion cell spikes were recorded by a central electrode (30 ?m diameter) in the planar grid of an electrode array. Extracellular stimulation (monophasic, cathodic, 0.1–1.0 ms) of the retinal network was performed using constant voltage pulses applied to the eight surrounding electrodes. The stimulation electrodes were equally spaced on the four sides of a square (400 × 400 ?m). Threshold voltage was determined as the pulse amplitude required to evoke network-mediated ganglion cell spiking in a defined post stimulus time window in 50% of identical stimulus repetitions. For the two electrode materials threshold voltage, transferred charge at threshold, maximum current and the residual current at the end of the pulse were compared. Main results. Stimulation of retinal interneurons using PEDOT–CNT electrodes is achieved with lower stimulation voltage and requires lower charge transfer as compared to TiN. The key parameter for effective stimulation is a constant current over at least 0.5 ms, which is obtained by PEDOT–CNT electrodes at lower stimulation voltage due to its faradaic charge transfer mechanism. Significance. In neuroprosthetic implants, PEDOT–CNT may allow for smaller electrodes, effective stimulation in a safe voltage regime and lower energy-consumption. Our study also indicates, that the charge transferred at threshold or the charge injection capacity per se does not determine stimulation efficacy.

Samba, R.; Herrmann, T.; Zeck, G.

2015-02-01

71

PEDOT-CNT coated electrodes stimulate retinal neurons at low voltage amplitudes and low charge densities.  

PubMed

Objective. The aim of this study was to compare two different microelectrode materials-the conductive polymer composite poly-3,4-ethylenedioxythiophene (PEDOT)-carbon nanotube(CNT) and titanium nitride (TiN)-at activating spikes in retinal ganglion cells in whole mount rat retina through stimulation of the local retinal network. Stimulation efficacy of the microelectrodes was analyzed by comparing voltage, current and transferred charge at stimulation threshold. Approach. Retinal ganglion cell spikes were recorded by a central electrode (30 ?m diameter) in the planar grid of an electrode array. Extracellular stimulation (monophasic, cathodic, 0.1-1.0 ms) of the retinal network was performed using constant voltage pulses applied to the eight surrounding electrodes. The stimulation electrodes were equally spaced on the four sides of a square (400 × 400 ?m). Threshold voltage was determined as the pulse amplitude required to evoke network-mediated ganglion cell spiking in a defined post stimulus time window in 50% of identical stimulus repetitions. For the two electrode materials threshold voltage, transferred charge at threshold, maximum current and the residual current at the end of the pulse were compared. Main results. Stimulation of retinal interneurons using PEDOT-CNT electrodes is achieved with lower stimulation voltage and requires lower charge transfer as compared to TiN. The key parameter for effective stimulation is a constant current over at least 0.5 ms, which is obtained by PEDOT-CNT electrodes at lower stimulation voltage due to its faradaic charge transfer mechanism. Significance. In neuroprosthetic implants, PEDOT-CNT may allow for smaller electrodes, effective stimulation in a safe voltage regime and lower energy-consumption. Our study also indicates, that the charge transferred at threshold or the charge injection capacity per se does not determine stimulation efficacy. PMID:25588201

Samba, R; Herrmann, T; Zeck, G

2015-02-01

72

Optimized Multi-Electrode Stimulation Increases Focality and Intensity at Target  

E-print Network

@ccny.cuny.edu Abstract. Transcranial direct current stimulation (tDCS) provides a noninvasive tool to elicit-Electrode Stimulation 2 1. Introduction Transcranial direct current stimulation (tDCS) is an emerging neurotechnology]-[5], epilepsy [6], Parkinson's disease [7], and motor and speech rehabilitation after stroke [8, 9]. Moreover, tDCS

Parra, Lucas C.

73

MRI INDUCED HEATING OF DEEP BRAIN STIMULATION LEADS: EFFECT OF THE AIR-TISSUE INTERFACE  

Microsoft Academic Search

Abstract—We have investigated the scattering of the Magnetic Resonance Imaging (MRI) radiofrequency (RF) field by implants for Deep Brain Stimulation (DBS) and the resultant heating of the tissue surrounding the DBS electrodes. The finite element method,has been used to perform full 3-D realistic simulations. The near field has been computed,for varying distances of the connecting portion of the lead from

Syed Ali Mohsin; Noor Muhammad Sheikh; Usman Saeed

2008-01-01

74

Sindrome di Tourette, stimolazione cerebrale per 'accordare' il cervello La deep brain stimulation (DBS), ovvero la stimolazione cerebrale profonda, in grado di  

E-print Network

Sindrome di Tourette, stimolazione cerebrale per 'accordare' il cervello La deep brain stimulation Tourette, una grave patologia neurologica che porta a diversi movimenti involontari del viso e del corpo'attività del cervello dei pazienti affetti da Sindrome di Tourette, compiendo importanti passi avanti nell

De Cindio, Fiorella

75

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

76

Deep brain stimulation: new techniques.  

PubMed

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

Hariz, Marwan

2014-01-01

77

Active Books: The Design of an Implantable Stimulator That Minimizes Cable Count Using Integrated Circuits Very Close to Electrodes  

Microsoft Academic Search

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

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

2012-01-01

78

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

79

Flexible Split-Ring Electrode for Insect Flight Biasing Using Multisite Neural Stimulation  

E-print Network

We describe a flexible multisite microelectrode for insect flight biasing using neural stimulation. The electrode is made of two layers of polyimide (PI) with gold sandwiched in between in a split-ring geometry. The ...

Tsang, Wei Mong

80

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

PubMed Central

Background Electrical stimulation of brain structures has been widely used in rodent models for kindling or modeling deep brain stimulation used clinically. This requires surgical implantation of intracranial electrodes and subsequent chronic stimulation in individual animals for several weeks. Anchoring screws and dental acrylic have long been used to secure implanted intracranial electrodes in rats. However, such an approach is limited when carried out in mouse models as the thin mouse skull may not be strong enough to accommodate the anchoring screws. We describe here a screw-free, glue-based method for implanting bipolar stimulating electrodes in the mouse brain and validate this method in a mouse model of hippocampal electrical kindling. Methods Male C57 black mice (initial ages of 6–8 months) were used in the present experiments. Bipolar electrodes were implanted bilaterally in the hippocampal CA3 area for electrical stimulation and electroencephalographic recordings. The electrodes were secured onto the skull via glue and dental acrylic but without anchoring screws. A daily stimulation protocol was used to induce electrographic discharges and motor seizures. The locations of implanted electrodes were verified by hippocampal electrographic activities and later histological assessments. Results Using the glue-based implantation method, we implanted bilateral bipolar electrodes in 25 mice. Electrographic discharges and motor seizures were successfully induced via hippocampal electrical kindling. Importantly, no animal encountered infection in the implanted area or a loss of implanted electrodes after 4–6 months of repetitive stimulation/recording. Conclusion We suggest that the glue-based, screw-free method is reliable for chronic brain stimulation and high-quality electroencephalographic recordings in mice. The technical aspects described this study may help future studies in mouse models. PMID:23914984

2013-01-01

81

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

82

Acute and chronic implantation of coiled wire intraneural electrodes during cyclical electrical stimulation  

Microsoft Academic Search

The posterior tibial nerves of 18 rabbits were intraneurally implanted with coiled wire electrodes for up to 9 weeks to evaluate\\u000a their usefulness for neuromuscular electrical stimulation. In one group an electrode was implanted and removed in one leg\\u000a while the other leg was chronically implanted. A second group was chronically implanted without electrical stimulation in\\u000a one leg and implanted

Bruce R. Bowman; Robert C. Erickson

1985-01-01

83

Electrical Stimulation of Mammalian Retinal Ganglion Cells Using Dense Arrays of Small-Diameter Electrodes  

NASA Astrophysics Data System (ADS)

Current epiretinal implants contain a small number of electrodes with diameters of a few hundred microns. Smaller electrodes are desirable to increase the spatial resolution of artificial sight. To lay the foundation for the next generation of retinal prostheses, we assessed the stimulation efficacy of micro-fabricated arrays of 61 platinum disk electrodes with diameters 8-12 ?m, spaced 60 ?m apart. Isolated pieces of rat, guinea pig, and monkey retina were placed on the multi-electrode array ganglion cell side down and stimulated through individual electrodes with biphasic, charge-balanced current pulses. Spike responses from retinal ganglion cells were recorded either from the same or a neighboring electrode. Most pulses evoked only 1-2 spikes with short latencies (0.3-10 ms), and rarely was more than one recorded ganglion cell stimulated. Threshold charge densities for eliciting spikes in ganglion cells were typically below 0.15 mC/cm2 for pulse durations between 50 and 200 ?s, corresponding to charge thresholds of ˜ 100 pC. Stimulation remained effective after several hours and at frequencies up to 100 Hz. Application of cadmium chloride did not abolish evoked spikes, implying direct activation. Thus, electrical stimulation of mammalian retina with small-diameter electrodes is achievable, providing high temporal and spatial precision with low charge densities.

Sekirnjak, Chris; Hottowy, Pawel; Sher, Alexander; Dabrowski, Wladyslaw; Litke, Alan M.; Chichilnisky, E. J.

84

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. PMID:23009589

2012-01-01

85

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

86

Biomechanical Simulation of Electrode Migration for Deep Brain Stimulation  

E-print Network

-operative electrode displacement and deformation may appear as the brain returns to its initial position when deformation and electrode migration due to brain shift. To achieve this goal, we propose a global approach the procedure (contacts between the brain and the inner part of the skull and falx cerebri, effect

Paris-Sud XI, Université de

87

Electrode spanning with partial tripolar stimulation mode in cochlear implants.  

PubMed

The perceptual effects of electrode spanning (i.e., the use of nonadjacent return electrodes) in partial tripolar (pTP) mode were tested on a main electrode EL8 in five cochlear implant (CI) users. Current focusing was controlled by ? (the ratio of current returned within the cochlea), and current steering was controlled by ? (the ratio of current returned to the basal electrode). Experiment 1 tested whether asymmetric spanning with ??=?0.5 can create additional channels around standard pTP stimuli. It was found that in general, apical spanning (i.e., returning current to EL6 rather than EL7) elicited a pitch between those of standard pTP stimuli on main electrodes EL8 and EL9, while basal spanning (i.e., returning current to EL10 rather than EL9) elicited a pitch between those of standard pTP stimuli on main electrodes EL7 and EL8. The pitch increase caused by apical spanning was more salient than the pitch decrease caused by basal spanning. To replace the standard pTP channel on the main electrode EL8 when EL7 or EL9 is defective, experiment 2 tested asymmetrically spanned pTP stimuli with various ?, and experiment 3 tested symmetrically spanned pTP stimuli with various ?. The results showed that pitch increased with decreasing ? in asymmetric spanning, or with increasing ? in symmetric spanning. Apical spanning with ? around 0.69 and basal spanning with ? around 0.38 may both elicit a similar pitch as the standard pTP stimulus. With the same ?, the symmetrically spanned pTP stimulus was higher in pitch than the standard pTP stimulus. A smaller ? was thus required for symmetric spanning to match the pitch of the standard pTP stimulus. In summary, electrode spanning is an effective field-shaping technique that is useful for adding spectral channels and handling defective electrodes with CIs. PMID:24865767

Wu, Ching-Chih; Luo, Xin

2014-12-01

88

Optimized multi-electrode stimulation increases focality and intensity at target  

NASA Astrophysics Data System (ADS)

Transcranial direct current stimulation (tDCS) provides a non-invasive tool to elicit neuromodulation by delivering current through electrodes placed on the scalp. The present clinical paradigm uses two relatively large electrodes to inject current through the head resulting in electric fields that are broadly distributed over large regions of the brain. In this paper, we present a method that uses multiple small electrodes (i.e. 1.2 cm diameter) and systematically optimize the applied currents to achieve effective and targeted stimulation while ensuring safety of stimulation. We found a fundamental trade-off between achievable intensity (at the target) and focality, and algorithms to optimize both measures are presented. When compared with large pad-electrodes (approximated here by a set of small electrodes covering 25cm2), the proposed approach achieves electric fields which exhibit simultaneously greater focality (80% improvement) and higher target intensity (98% improvement) at cortical targets using the same total current applied. These improvements illustrate the previously unrecognized and non-trivial dependence of the optimal electrode configuration on the desired electric field orientation and the maximum total current (due to safety). Similarly, by exploiting idiosyncratic details of brain anatomy, the optimization approach significantly improves upon prior un-optimized approaches using small electrodes. The analysis also reveals the optimal use of conventional bipolar montages: maximally intense tangential fields are attained with the two electrodes placed at a considerable distance from the target along the direction of the desired field; when radial fields are desired, the maximum-intensity configuration consists of an electrode placed directly over the target with a distant return electrode. To summarize, if a target location and stimulation orientation can be defined by the clinician, then the proposed technique is superior in terms of both focality and intensity as compared to previous solutions and is thus expected to translate into improved patient safety and increased clinical efficacy.

Dmochowski, Jacek P.; Datta, Abhishek; Bikson, Marom; Su, Yuzhuo; Parra, Lucas C.

2011-08-01

89

Neural origin of evoked potentials during thalamic deep brain stimulation  

PubMed Central

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 (R2 = 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.

2013-01-01

90

Computational modeling of pedunculopontine nucleus deep brain stimulation  

NASA Astrophysics Data System (ADS)

Objective. Deep brain stimulation (DBS) near the pedunculopontine nucleus (PPN) has been posited to improve medication-intractable gait and balance problems in patients with Parkinson's disease. However, clinical studies evaluating this DBS target have not demonstrated consistent therapeutic effects, with several studies reporting the emergence of paresthesia and oculomotor side effects. The spatial and pathway-specific extent to which brainstem regions are modulated during PPN-DBS is not well understood. Approach. Here, we describe two computational models that estimate the direct effects of DBS in the PPN region for human and translational non-human primate (NHP) studies. The three-dimensional models were constructed from segmented histological images from each species, multi-compartment neuron models and inhomogeneous finite element models of the voltage distribution in the brainstem during DBS. Main Results. The computational models predicted that: (1) the majority of PPN neurons are activated with -3 V monopolar cathodic stimulation; (2) surgical targeting errors of as little as 1 mm in both species decrement activation selectivity; (3) specifically, monopolar stimulation in caudal, medial, or anterior PPN activates a significant proportion of the superior cerebellar peduncle (up to 60% in the human model and 90% in the NHP model at -3 V) (4) monopolar stimulation in rostral, lateral or anterior PPN activates a large percentage of medial lemniscus fibers (up to 33% in the human model and 40% in the NHP model at -3 V) and (5) the current clinical cylindrical electrode design is suboptimal for isolating the modulatory effects to PPN neurons. Significance. We show that a DBS lead design with radially-segmented electrodes may yield improved functional outcome for PPN-DBS.

Zitella, Laura M.; Mohsenian, Kevin; Pahwa, Mrinal; Gloeckner, Cory; Johnson, Matthew D.

2013-08-01

91

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

PubMed

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 the 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 children with epilepsy 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. PMID:22554977

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

2012-06-01

92

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. PMID:22295102

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

2012-01-01

93

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

94

Compact Nonlinear Model of an Implantable Electrode Array for Spinal Cord Stimulation (SCS).  

PubMed

We describe the construction of a model of the electrode-electrolyte interface and surrounding electrolyte in the case of a platinum-electrode array intended for spinal-cord stimulation (SCS) application. We show that a finite, two-dimensional, resistor array provides a satisfactory model of the bulk electrolyte, and we identify the complexity required of that resistor array. The electrode-electrolyte interface is modelled in a fashion suitable for commonly-available, compact simulators using a nonlinear extension of the model of Franks (IEEE Trans. Biomed. Eng., vol. 52 , no. 7 , pp. 1295-1302, Jul. 2005) that incorporates diodes and a memristor. The electrode-electrolyte interface model accounts for the nonlinear current-overpotential characteristic and diffusion-limiting effects. We characterise a commercial, implantable, electrode array, fit the model to it, and show that the model successfully predicts subtle operational characteristics. PMID:23893748

Scott, Jonathan; Single, Peter

2013-07-23

95

Artificial neural network based characterization of the volume of tissue activated during deep brain stimulation  

NASA Astrophysics Data System (ADS)

Objective. Clinical deep brain stimulation (DBS) systems can be programmed with thousands of different stimulation parameter combinations (e.g. electrode contact(s), voltage, pulse width, frequency). Our goal was to develop novel computational tools to characterize the effects of stimulation parameter adjustment for DBS. Approach. The volume of tissue activated (VTA) represents a metric used to estimate the spatial extent of DBS for a given parameter setting. Traditional methods for calculating the VTA rely on activation function (AF)-based approaches and tend to overestimate the neural response when stimulation is applied through multiple electrode contacts. Therefore, we created a new method for VTA calculation that relied on artificial neural networks (ANNs). Main results. The ANN-based predictor provides more accurate descriptions of the spatial spread of activation compared to AF-based approaches for monopolar stimulation. In addition, the ANN was able to accurately estimate the VTA in response to multi-contact electrode configurations. Significance. The ANN-based approach may represent a useful method for fast computation of the VTA in situations with limited computational resources, such as a clinical DBS programming application on a tablet computer.

Chaturvedi, Ashutosh; Luján, J. Luis; McIntyre, Cameron C.

2013-10-01

96

Recording evoked potentials during deep brain stimulation: development and validation of instrumentation to suppress the stimulus artefact  

NASA Astrophysics Data System (ADS)

The clinical efficacy of deep brain stimulation (DBS) for the treatment of movement disorders depends on the identification of appropriate stimulation parameters. Since the mechanisms of action of DBS remain unclear, programming sessions can be time consuming, costly and result in sub-optimal outcomes. Measurement of electrically evoked compound action potentials (ECAPs) during DBS, generated by activated neurons in the vicinity of the stimulating electrode, could offer insight into the type and spatial extent of neural element activation and provide a potential feedback signal for the rational selection of stimulation parameters and closed-loop DBS. However, recording ECAPs presents a significant technical challenge due to the large stimulus artefact, which can saturate recording amplifiers and distort short latency ECAP signals. We developed DBS-ECAP recording instrumentation combining commercial amplifiers and circuit elements in a serial configuration to reduce the stimulus artefact and enable high fidelity recording. We used an electrical circuit equivalent model of the instrumentation to understand better the sources of the stimulus artefact and the mechanisms of artefact reduction by the circuit elements. In vitro testing validated the capability of the instrumentation to suppress the stimulus artefact and increase gain by a factor of 1000 to 5000 compared to a conventional biopotential amplifier. The distortion of mock ECAP (mECAP) signals was measured across stimulation parameters, and the instrumentation enabled high fidelity recording of mECAPs with latencies of only 0.5 ms for DBS pulse widths of 50 to 100 µs/phase. Subsequently, the instrumentation was used to record in vivo ECAPs, without contamination by the stimulus artefact, during thalamic DBS in an anesthetized cat. The characteristics of the physiological ECAP were dependent on stimulation parameters. The novel instrumentation enables high fidelity ECAP recording and advances the potential use of the ECAP as a feedback signal for the tuning of DBS parameters.

Kent, A. R.; Grill, W. M.

2012-06-01

97

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. PMID:24892420

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

2014-01-01

98

Interdigitated array of Pt electrodes for electrical stimulation and engineering of aligned muscle tissue.  

PubMed

Engineered skeletal muscle tissues could be useful for applications in tissue engineering, drug screening, and bio-robotics. It is well-known that skeletal muscle cells are able to differentiate under electrical stimulation (ES), with an increase in myosin production, along with the formation of myofibers and contractile proteins. In this study, we describe the use of an interdigitated array of electrodes as a novel platform to electrically stimulate engineered muscle tissues. The resulting muscle myofibers were analyzed and quantified in terms of their myotube characteristics and gene expression. The engineered muscle tissues stimulated through the interdigitated array of electrodes demonstrated superior performance and maturation compared to the corresponding tissues stimulated through a conventional setup (i.e., through Pt wires in close proximity to the muscle tissue). In particular, the ES of muscle tissue (voltage 6 V, frequency 1 Hz and duration 10 ms for 1 day) through the interdigitated array of electrodes resulted in a higher degree of C2C12 myotube alignment (?80%) as compared to ES using Pt wires (?65%). In addition, higher amounts of C2C12 myotube coverage area, myotube length, muscle transcription factors and protein biomarkers were found for myotubes stimulated through the interdigitated array of electrodes compared to those stimulated using the Pt wires. Due to the wide array of potential applications of ES for two- and three-dimensional (2D and 3D) engineered tissues, the suggested platform could be employed for a variety of cell and tissue structures to more efficiently investigate their response to electrical fields. PMID:22847280

Ahadian, Samad; Ramón-Azcón, Javier; Ostrovidov, Serge; Camci-Unal, Gulden; Hosseini, Vahid; Kaji, Hirokazu; Ino, Kosuke; Shiku, Hitoshi; Khademhosseini, Ali; Matsue, Tomokazu

2012-09-21

99

Sensing-enabled hippocampal deep brain stimulation in idiopathic nonhuman primate epilepsy.  

PubMed

Epilepsy is a debilitating condition affecting 1% of the population worldwide. Medications fail to control seizures in at least 30% of patients, and deep brain stimulation (DBS) is a promising alternative treatment. A modified clinical DBS hardware platform was recently described (PC+S) allowing long-term recording of electrical brain activity such that effects of DBS on neural networks can be examined. This study reports the first use of this device to characterize idiopathic epilepsy and assess the effects of stimulation in a nonhuman primate (NHP). Clinical DBS electrodes were implanted in the hippocampus of an epileptic NHP bilaterally, and baseline local field potential (LFP) recordings were collected for seizure characterization with the PC+S. Real-time automatic detection of ictal events was demonstrated and validated by concurrent visual observation of seizure behavior. Seizures consisted of large-amplitude 8- to 25-Hz oscillations originating from the right hemisphere and quickly generalizing, with an average occurrence of 0.71 ± 0.15 seizures/day. Various stimulation parameters resulted in suppression of LFP activity or in seizure induction during stimulation under ketamine anesthesia. Chronic stimulation in the awake animal was studied to evaluate how seizure activity was affected by stimulation configurations that suppressed broadband LFPs in acute experiments. This is the first electrophysiological characterization of epilepsy using a next-generation clinical DBS system that offers the ability to record and analyze neural signals from a chronically implanted stimulating electrode. These results will direct further development of this technology and ultimately provide insight into therapeutic mechanisms of DBS for epilepsy. PMID:25429118

Lipski, W J; DeStefino, V J; Stanslaski, S R; Antony, A R; Crammond, D J; Cameron, J L; Richardson, R M

2015-02-15

100

Deep brain stimulation for movement and other neurologic disorders  

PubMed Central

Deep brain stimulation was introduced as a treatment for patients with Parkinsonism and other movement disorders in the early 1990s. The technique rapidly became the treatment of choice for these conditions, and is now also being explored for other diseases, including Tourette syndrome, gait disorders, epilepsy, obsessive-compulsive disorder, and depression. Although the mechanism of action of DBS remains unclear, it is recognized that DBS works through focal modulation of functionally specific circuits. The fact that that the same DBS parameters and targets can be used in multiple diseases suggests that DBS does not counteract the pathophysiology of any specific disorder, but acts to replace pathologic activities in disease-affected brain circuits with activity that is more easily tolerated. Despite the progress made in the use of DBS, much remains to be done to fully realize the potential of this therapy. We describe some of the most active areas of research in this field, both in terms of exploration of new targets and stimulation parameters, and in terms of new electrode or stimulator designs. PMID:22823512

DeLong, Mahlon; Wichmann, Thomas

2015-01-01

101

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

102

Improved spatial targeting with directionally segmented deep brain stimulation leads for treating essential tremor  

NASA Astrophysics Data System (ADS)

Deep brain stimulation (DBS) in the ventral intermediate nucleus of thalamus (Vim) is known to exert a therapeutic effect on postural and kinetic tremor in patients with essential tremor (ET). For DBS leads implanted near the caudal border of Vim, however, there is an increased likelihood that one will also induce paresthesia side-effects by stimulating neurons within the sensory pathway of the ventral caudal (Vc) nucleus of thalamus. The aim of this computational study was to (1) investigate the neuronal pathways modulated by therapeutic, sub-therapeutic and paresthesia-inducing DBS settings in three patients with ET and (2) determine how much better an outcome could have been achieved had these patients been implanted with a DBS lead containing directionally segmented electrodes (dDBS). Multi-compartment neuron models of the thalamocortical, cerebellothalamic and medial lemniscal pathways were first simulated in the context of patient-specific anatomies, lead placements and programming parameters from three ET patients who had been implanted with Medtronic 3389 DBS leads. The models showed that in these patients, complete suppression of tremor was associated most closely with activating an average of 62% of the cerebellothalamic afferent input into Vim (n = 10), while persistent paresthesias were associated with activating 35% of the medial lemniscal tract input into Vc thalamus (n = 12). The dDBS lead design demonstrated superior targeting of the cerebello-thalamo-cortical pathway, especially in cases of misaligned DBS leads. Given the close proximity of Vim to Vc thalamus, the models suggest that dDBS will enable clinicians to more effectively sculpt current through and around thalamus in order to achieve a more consistent therapeutic effect without inducing side-effects.

Keane, Maureen; Deyo, Steve; Abosch, Aviva; Bajwa, Jawad A.; Johnson, Matthew D.

2012-08-01

103

Effects of Bilateral Deep Brain Stimulation of the Subthalamic Nucleus on Olfactory Function in Parkinson’s Disease Patients  

Microsoft Academic Search

Objective: The goal of the present study was to evaluate the effects of bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) on olfaction in patients with Parkinson’s disease (PD). Methods: 15 patients suffering from sporadic PD-related dysosmia were implanted with bilateral electrodes aimed at the STN. One week before the surgery, odor detection threshold (DT) and identification threshold

Xiaodong Guo; Guodong Gao; Xuelian Wang; Lihong Li; Weixin Li; Qinchuan Liang; Hua Zhang

2008-01-01

104

Evaluation of different stimulation and measurement patterns based on internal electrode: application in cardiac impedance tomography.  

PubMed

The conductivity distribution around the thorax is altered during the cardiac cycle due to the blood perfusion, heart contraction and lung inflation. Previous studies showed that these bio-impedance changes are appropriate for non-invasive cardiac function imaging using Electrical Impedance Tomography (EIT) techniques. However, the spatial resolution is presently low. One of the main obstacles in cardiac imaging at the heart location is the large impedance variation of the lungs by respiration and muscles on the dorsal and posterior side of the body. In critical care units there is a potential to insert an internal electrode inside the esophagus directly behind the heart in the same plane of the external electrodes. The aim of the present study is to evaluate different current stimulation and measurement patterns with both external and internal electrodes. Analysis is performed with planar arrangement of 16 electrodes for a simulated 3D cylindrical tank and pig thorax model. In our study we evaluated current injection patterns consisting of adjacent, diagonal, trigonometric, and radial to the internal electrode. The performance of these arrangements was assessed using quantitative methods based on distinguishability, sensitivity and GREIT (Graz consensus Reconstruction algorithm for Electrical Impedance Tomography). Our evaluation shows that an internal electrode configuration based on the trigonometric injection patterns has better performance and improves pixel intensity of the small conductivity changes related to heart near 1.7 times in reconstructed images and also shows more stability with different levels of added noise. For the internal electrode, when we combined radial or adjacent injection with trigonometric injection pattern, we found an improvement in amplitude response. However, the combination of diagonal with trigonometric injection pattern deteriorated the shape deformation (correlation coefficient r=0.344) more than combination of radial and trigonometric injection (correlation coefficient r=0.836) for the perturbations in the area close to the center of the cylinder. We also find that trigonometric stimulation pattern performance is degraded in a realistic thorax model with anatomical asymmetry. For that reason we recommend using internal electrodes only for voltage measurements and as a reference electrode during trigonometric stimulation patterns in practical measurements. PMID:23017828

Nasehi Tehrani, J; Oh, T I; Jin, C; Thiagalingam, A; McEwan, A

2012-11-01

105

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

PubMed

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

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

2015-01-01

106

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 PMID:24068272

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

2013-01-01

107

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

PubMed

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. PMID:24068272

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

2013-01-01

108

Site of Deep Brain Stimulation and Jaw Velocity in Parkinson’s Disease  

PubMed Central

Object While deep brain stimulation (DBS) has proven to be an effective treatment for many symptoms of Parkinson’s disease (PD), a deterioration of axial symptoms frequently occurs, particularly for speech and swallowing. These unfavorable effects of DBS may depend on the site of stimulation. We made quantitative measures of jaw velocity to compare the relative effectiveness of DBS in the globus pallidus internus (GPi) or the subthalamic nucleus (STN). Design Randomized, double-blind, and longitudinal, with matched healthy control subjects Methods The peak velocities of self-scaled and externally-scaled jaw movements were studied in 27 PD patients before and after 6 months of bilateral DBS in the GPi or the STN. A mixed-effects model was used to identify differences in jaw velocity before DBS surgery (baseline) while off and on levodopa therapy, and after 6 months of DBS (postoperative) during four treatment conditions (off- and on-levodopa states with and without DBS). Results Self-scaled jaw velocity was impaired by the DBS procedure in STN; velocity was significantly decreased across all postoperative conditions compared to either the off- and on-levodopa baseline conditions. In contrast, the GPi group postoperatively was generally faster than the baseline off levodopa state. Turning the DBS off and on had no effect on jaw velocity in either group. Unlike baseline, levodopa therapy postoperatively no longer increased jaw velocity in either group, and this lack of effect was not related to postoperative changes in dose. The externally-scaled jaw velocity was little affected by PD, but DBS still slightly affected performance, with the STN group significantly slower than the GPi group for most conditions. Conclusions Our results suggest that either the electrode implant in STN or the subsequent period of continuous STN stimulation negatively affected voluntary jaw velocity, including the loss of the preoperative levodopa induced improvement. While the GPi group showed some improvement in voluntary jaw velocity postoperatively, their performance during the combination of DBS and levodopa was not different than their best medical management presurgery. The results have implications for DBS target selection, particularly for those patients with oromotor dysfunctions. PMID:21838506

Robertson, Lee T.; St George, Rebecca J.; Carlson-Kuhta, Patricia; Hogarth, Penelope; Burchiel, Kim J.; Horak, Fay B.

2012-01-01

109

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

110

What is the optimal anodal electrode position for inducing corticomotor excitability changes in transcranial direct current stimulation?  

PubMed

Transcranial direct current stimulation (tDCS) non-invasively modulates brain function by inducing neuronal excitability. The conventional hot spot for inducing the highest current density in the hand motor area may not be the optimal site for effective stimulation. In this study, we investigated the influence of the center position of the anodal electrode on changes in motor cortical excitability. We considered three tDCS conditions in 16 healthy subjects: (i) real stimulation with the anodal electrode located at the conventional hand motor hot spot determined by motor evoked potentials (MEPs); (ii) real stimulation with the anodal electrode located at the point with the highest current density in the hand motor area as determined by electric current simulation; and (iii) sham stimulation. Motor cortical excitability as measured by MEP amplitude increased after both real stimulation conditions, but not after sham stimulation. Stimulation using the simulation-derived anodal electrode position, which was found to be posterior to the MEP hot spot for all subjects, induced higher motor cortical excitability. Individual positioning of the anodal electrode, based on the consideration of anatomical differences between subjects, appears to be important for maximizing the effects of tDCS. PMID:25450146

Lee, Minji; Kim, Yun-Hee; Im, Chang-Hwan; Kim, Jung-Hoon; Park, Chang-Hyun; Chang, Won Hyuk; Lee, Ahee

2015-01-01

111

Electrodic voltages accompanying stimulated bioremediation of a uranium-contaminated aquifer  

SciTech Connect

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

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

2009-11-15

112

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

113

Transcranial focal stimulation via concentric ring electrodes reduced power of pentylenetetrazole-induced seizure activity in rat electroencephalogram  

Microsoft Academic Search

As epilepsy affects approximately one percent of the world population, electrical stimulation of the brain has recently shown potential for additive seizure control therapy. In this study we applied noninvasive transcranial focal stimulation (TFS) via concentric ring electrodes on the scalp of rats after inducing seizures with pentylenetetrazole (PTZ) to assess the effect of TFS on the electrographic activity. Grand

Oleksandr Makeyev; Xiang Liu; Kanthaiah Koka; Steven M. Kay; Walter G. Besio

2011-01-01

114

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.

115

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

116

The effect of electrode placement and interphase interval on force production during stimulation of the dorsiflexor muscles.  

PubMed

The aims of this study were to investigate whether introducing an interphase interval (IPI) to biphasic pulses during stimulation of the dorsiflexor muscles would affect force production and to determine whether the IPI effect is dependent on electrode position. Twelve healthy volunteers participated in the study. Each subject participated in one session during which electrically induced contraction (EIC) forces of the ankle dorsiflexors were measured with five different IPI settings ranging from 0 to 400??s. Forces of EICs were assessed with the electrodes placed either with the proximal electrode positioned over the common peroneal nerve and the second electrode over the dorsiflexor muscles or with both electrodes located over the dorsiflexor muscles. The order of electrode placements and of the different IPI settings was randomized across subjects. The results indicated that the introduction of a 100-?s-long IPI may enhance force production when one electrode is located over the common peroneal nerve. However, increasing the duration of the IPI beyond 100??s did not result in further increase in force production. In contrast, the introduction of an IPI did not increase force production when both electrodes were located over the dorsiflexor muscles. These findings may help to optimize stimulation settings during functional electrical stimulation to prevent foot-drop. PMID:25039590

Springer, Shmuel; Braun-Benyamin, Orit; Abraham-Shitreet, Chen; Becher, Meni; Laufer, Yocheved

2014-11-01

117

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

PubMed

Objective. The dorsal root ganglion is an attractive target for implanting neural electrode arrays that restore sensory function or provide therapy via stimulation. However, penetrating microelectrodes designed for these applications are small and deliver low currents. For long-term performance of microstimulation devices, novel coating materials are needed in part to decrease impedance values at the electrode-tissue interface and to increase charge storage capacity. Approach. Conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and multi-wall carbon nanotubes (CNTs) were coated on the electrode surface and doped with the anti-inflammatory drug, dexamethasone. Electrode characteristics and the tissue reaction around neural electrodes as a result of stimulation, coating and drug release were characterized. Hematoxylin and eosin staining along with antibodies recognizing Iba1 (microglia/macrophages), NF200 (neuronal axons), NeuN (neurons), vimentin (fibroblasts), caspase-3 (cell death) and L1 (neural cell adhesion molecule) were used. Quantitative image analyses were performed using MATLAB. Main results. Our results indicate that coated microelectrodes have lower in vitro and in vivo impedance values. Significantly less neuronal death/damage was observed with coated electrodes as compared to non-coated controls. The inflammatory response with the PEDOT/CNT-coated electrodes was also reduced. Significance. This study is the first to report on the utility of these coatings in stimulation applications. Our results indicate PEDOT/CNT coatings may be valuable additions to implantable electrodes used as therapeutic modalities. PMID:25485675

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

2014-12-01

118

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

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

119

Charge trapping induced by plasma in alumina electrode surface investigated by thermoluminescence and optically stimulated luminescence  

SciTech Connect

The plasma of a dielectric barrier discharge can fill traps in the alumina that cover the electrode. Trap energies and lifetimes are estimated by thermoluminescence and optically stimulated luminescence. Comparison with similar results for traps created by other radiation sources clarifies the mechanisms regulating this effect. Alumina's trap energies are approximately 1 eV, and the traps remain active for several days after plasma exposure. These results could be important to keep dielectric barrier discharge plasmas uniform since a trapped charge can be an electron reservoir.

Ambrico, P. F. [CNR-IMIP Sezione di Bari, Via Orabona, 4 I-70126 Bari (Italy); Ambrico, M. [CNR-IMIP Sezione di Bari, Via Orabona, 4 I-70126 Bari (Italy); CNISM Unita di Ricerca Bari Universita, Universita degli Studi di Bari, Via Amendola, 173 I-70126-Bari (Italy); Schiavulli, L. [CNISM Unita di Ricerca Bari Universita, Universita degli Studi di Bari, Via Amendola, 173 I-70126-Bari (Italy); INFN-Sezione di Bari, Via Amendola, 173 I-70126 Bari (Italy); Dipartimento Interateneo di Fisica, Universita degli Studi di Bari, Via Amendola, 173 I-70126 Bari (Italy); Ligonzo, T.; Augelli, V. [CNISM Unita di Ricerca Bari Universita, Universita degli Studi di Bari, Via Amendola, 173 I-70126-Bari (Italy); Dipartimento Interateneo di Fisica, Universita degli Studi di Bari, Via Amendola, 173 I-70126 Bari (Italy)

2009-02-02

120

Computational Study on Subdural Cortical Stimulation - The Influence of the Head Geometry, Anisotropic Conductivity, and Electrode Configuration  

PubMed Central

Subdural cortical stimulation (SuCS) is a method used to inject electrical current through electrodes beneath the dura mater, and is known to be useful in treating brain disorders. However, precisely how SuCS must be applied to yield the most effective results has rarely been investigated. For this purpose, we developed a three-dimensional computational model that represents an anatomically realistic brain model including an upper chest. With this computational model, we investigated the influence of stimulation amplitudes, electrode configurations (single or paddle-array), and white matter conductivities (isotropy or anisotropy). Further, the effects of stimulation were compared with two other computational models, including an anatomically realistic brain-only model and the simplified extruded slab model representing the precentral gyrus area. The results of voltage stimulation suggested that there was a synergistic effect with the paddle-array due to the use of multiple electrodes; however, a single electrode was more efficient with current stimulation. The conventional model (simplified extruded slab) far overestimated the effects of stimulation with both voltage and current by comparison to our proposed realistic upper body model. However, the realistic upper body and full brain-only models demonstrated similar stimulation effects. In our investigation of the influence of anisotropic conductivity, model with a fixed ratio (1?10) anisotropic conductivity yielded deeper penetration depths and larger extents of stimulation than others. However, isotropic and anisotropic models with fixed ratios (1?2, 1?5) yielded similar stimulation effects. Lastly, whether the reference electrode was located on the right or left chest had no substantial effects on stimulation. PMID:25229673

Kim, Donghyeon; Seo, Hyeon; Kim, Hyoung-Ihl; Jun, Sung Chan

2014-01-01

121

A latent force model for describing electric propagation in deep brain stimulation: A simulation study.  

PubMed

Deep brain stimulation (DBS) is a neurosurgical method used to treat symptoms of movement disorders by implanting electrodes in deep brain areas. Often, the DBS modeling approaches found in the literature assume a quasi-static approximation, and discard any dynamic behavior. Nevertheless, in a real DBS system the stimulus corresponds to a wave that changes as a function of time. It is clear that DBS demands an approach that takes into account the time-varying behavior of the input stimulus. In this work, we present a novel latent force model for describing the dynamic electric propagation occurred during DBS. The performance of the proposed model was studied by simulations under different conditions. The results show that our approach is able to take into account the time variations of the source and the produced field. Moreover, by restricting our model it is possible to obtain solutions for electrostatic formulations, here experimental results were compared with the finite element method. Additionally, our approach allows a solution to the inverse problem, which is a valuable clinical application allowing the appropriate tuning of the DBS device by the expert physician. PMID:25570527

Alvarado, Pablo A; Alvarez, Mauricio A; Daza-Santacoloma, Genaro; Orozco, Alvaro; Castellanos-Dominguez, German

2014-08-01

122

Simulating a dual-array electrode configuration to investigate the influence of skeletal muscle fatigue following functional electrical stimulation.  

PubMed

A novel, anatomically-accurate model of a tibialis anterior muscle is used to investigate the electro-physiological properties of denervated muscles following functional electrical stimulation. The model includes a state-of-the-art description of cell electro-physiology. The main objective of this work is to develop a computational framework capable of predicting the effects of different stimulation trains and electrode configurations on the excitability and fatigue of skeletal muscle tissue. Utilizing a reduced but computationally amenable model, the effects of different electrode sizes and inter-electrode distances on the number of activated muscle fibers are investigated and qualitatively compared to existing literature. To analyze muscle fatigue, the sodium current, specifically the K+ ion concentrations within the t-tubule and the calcium release from the sarcoplasmic reticulum, is used to quantify membrane and metabolic fatigue. The simulations demonstrate that lower stimulation frequencies and biphasic pulse waveforms cause less fatigue than higher stimulation frequencies and monophasic pulses. A comparison between single and dual electrode configurations (with the same overall stimulation surface) is presented to locally investigate the differences in muscle fatigue. The dual electrode configuration causes the muscle tissue to fatigue quicker. PMID:22841365

Kim, Juliana H K; Trew, Mark L; Pullan, Andrew J; Röhrle, Oliver

2012-09-01

123

Artifact properties of carbon nanotube yarn electrode in magnetic resonance imaging  

NASA Astrophysics Data System (ADS)

Objective. Deep brain stimulating (DBS) is a rapidly developing therapy that can treat many refractory neurological diseases. However, the traditional DBS electrodes which are made of Pt-Ir alloy may induce severe field distortions in magnetic resonance imaging (MRI) which leads to artifacts that will lower the local image quality and cause inconvenience or interference. A novel DBS electrode made from carbon nanotube yarns (CNTYs) is brought up to reduce the artifacts. This study is therefore to evaluate the artifact properties of the novel electrode. Approach. We compared its MR artifact characteristics with the Pt-Ir electrode in water phantom, including its artifact behaviors at different orientations as well as at various off-center positions, using both spin echo (SE) and gradient echo (GE) sequences, and confirmed its performance in vivo. Main results. The results in phantom showed that the CNTY electrode artifacts reduced as much as 62% and 74% on GE and SE images, respectively, compared to the Pt-Ir one. And consistent behaviors were confirmed in vivo. The susceptibility difference was identified as the dominant cause in producing artifacts. Significance. Employing the CNTY electrode may generate much less field distortion in the vicinity, improve local MR image quality and possibly be beneficial in various aspects.

Jiang, C. Q.; Hao, H. W.; Li, L. M.

2013-04-01

124

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 1 week 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

125

Deep brain stimulation for dystonia  

PubMed Central

Deep brain stimulation (DBS) is an effective surgical treatment for medication-refractory movement disorders, and has been approved by the United States Food and Drug Administration for treatment of dystonia. The success of DBS in the treatment of dystonia depends on our understanding of the anatomy and physiology of this disorder and close collaboration between neurosurgeons, neurologists, clinical neurophysiologists, neuroradiologists and neuropsychologists. Currently, pallidal DBS is an established treatment option for medically refractive dystonia. This review is intended to provide a comprehensive review of the use of DBS for dystonia, focusing mainly on the surgical aspects, clinical outcome, MRI findings and side effects of DBS. PMID:24444300

2014-01-01

126

A Long Term Effects of a New Onset Psychosis after DBS Treated with Quetiapine in a Patient with Parkinson's Disease  

PubMed Central

Deep Brain Stimulation represents a therapeutic option for PD patients. In this paper, we present and discuss a case of acute delirium and psychosis manifesting after DBS in a 58-years-old man affected by Parkinson's Disease. We highlight the importance of an exhaustive psychiatric evaluation in candidates for DBS and we underline the severity and non-reversibility of some adverse events associated with the implantation, suggesting the use of Quetiapine in the management of these effects. Acute psychosis may be listed as a potential severe adverse event associated with DBS, even in patients without a clear cut previous history of psychiatric disorders.

Perini, Giulia; Pizzighello, Silvia; Vestri, Alec; Ferri, Giovanni; Toffanin, Tommaso; Follador, Halima; Martinuzzi, Andrea

2015-01-01

127

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

NASA Astrophysics Data System (ADS)

Objective. Intra-retinal placement of stimulating electrodes can provide close and stable proximity to target neurons. We assessed improvement in stimulation thresholds and selectivity of the direct and network-mediated retinal stimulation with intraretinal electrodes, compared to epiretinal and subretinal placements. Approach. Stimulation thresholds of the retinal ganglion cells (RGCs) in wild-type rat retina were measured using the patch-clamp technique. Direct and network-mediated responses were discriminated using various synaptic blockers. Main results. Three types of RGC responses were identified: short latency (SL, ? < 5 ms) originating in RGCs, medium latency (ML, 3 < ? < 70 ms) originating in the inner nuclear layer and long latency (LL, ? > 40 ms) originating in photoreceptors. Cathodic epiretinal stimulation exhibited the lowest threshold for direct RGC response and the highest direct selectivity (network/direct thresholds ratio), exceeding a factor of 3 with pulse durations below 0.5 ms. For network-mediated stimulation, the lowest threshold was obtained with anodic pulses in OPL position, and its network selectivity (direct/network thresholds ratio) increased with pulse duration, exceeding a factor of 4 at 10 ms. Latency of all three types of responses decreased with increasing strength of the stimulus. Significance. These results define the optimal range of pulse durations, pulse polarities and electrode placement for the retinal prostheses aiming at direct or network-mediated stimulation of RGCs.

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

2014-04-01

128

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

129

Lateralized effect of pallidal stimulation on self-mutilation in Lesch-Nyhan disease.  

PubMed

Lesch-Nyhan disease (LND) is an X-linked hereditary disorder caused by a deficiency of hypoxanthine-guanine phosphoribosyltransferase. This syndrome is characterized by hyperuricemia, self-mutilation, cognitive impairment, and movement disorders such as spasticity and dystonia. The authors describe the case of a 15-year-old boy who underwent bilateral placement of globus pallidus internus (GPi) deep brain stimulation (DBS) electrodes for the treatment of generalized dystonia. His self-mutilating behavior gradually disappeared several weeks after the start of GPi stimulation. The dystonia and self-mutilating behavior returned on the left side only after a right lead fracture. This case is the first reported instance of LND treated with DBS in which the stimulation was interrupted and the self-mutilation returned in a lateralized fashion. The findings indicate that the neurobehavioral aspect of LND is lateralized and that contralateral GPi stimulation is responsible for lateralized improvement in self-injurious behavior. PMID:25303157

Abel, Taylor J; Dalm, Brian D; Grossbach, Andrew J; Jackson, Adam W; Thomsen, Teri; Greenlee, Jeremy D W

2014-12-01

130

Effects of antidromic and orthodromic activation of STN afferent axons during DBS in Parkinson's disease: a simulation study  

PubMed Central

Recent studies suggest that subthalamic nucleus (STN)-Deep Brain Stimulation (DBS) may exert at least part of its therapeutic effect through the antidromic suppression of pathological oscillations in the cortex in 6-OHDA treated rats and in parkinsonian patients. STN-DBS may also activate STN neurons by initiating action potential propagation in the orthodromic direction, similarly resulting in suppression of pathological oscillations in the STN. While experimental studies have provided strong evidence in support of antidromic stimulation of cortical neurons, it is difficult to separate relative contributions of antidromic and orthodromic effects of STN-DBS. The aim of this computational study was to examine the effects of antidromic and orthodromic activation on neural firing patterns and beta-band (13-30 Hz) oscillations in the STN and cortex during DBS of STN afferent axons projecting from the cortex. High frequency antidromic stimulation alone effectively suppressed simulated beta activity in both the cortex and STN-globus pallidus externa (GPe) network. High frequency orthodromic stimulation similarly suppressed beta activity within the STN and GPe through the direct stimulation of STN neurons driven by DBS at the same frequency as the stimulus. The combined effect of both antidromic and orthodromic stimulation modulated cortical activity antidromically while simultaneously orthodromically driving STN neurons. While high frequency DBS reduced STN beta-band power, low frequency stimulation resulted in resonant effects, increasing beta-band activity, consistent with previous experimental observations. The simulation results indicate effective suppression of simulated oscillatory activity through both antidromic stimulation of cortical neurons and direct orthodromic stimulation of STN neurons. The results of the study agree with experimental recordings of STN and cortical neurons in rats and support the therapeutic potential of stimulation of cortical neurons. PMID:24678296

Kang, Guiyeom; Lowery, Madeleine M.

2014-01-01

131

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

132

Intra-Operative Behavioral Tasks in Awake Humans Undergoing Deep Brain Stimulation Surgery  

PubMed Central

Deep brain stimulation (DBS) is a surgical procedure that directs chronic, high frequency electrical stimulation to specific targets in the brain through implanted electrodes. Deep brain stimulation was first implemented as a therapeutic modality by Benabid et al. in the late 1980s, when he used this technique to stimulate the ventral intermediate nucleus of the thalamus for the treatment of tremor 1. Currently, the procedure is used to treat patients who fail to respond adequately to medical management for diseases such as Parkinson's, dystonia, and essential tremor. The efficacy of this procedure for the treatment of Parkinson's disease has been demonstrated in well-powered, randomized controlled trials 2. Presently, the U.S. Food and Drug Administration has approved DBS as a treatment for patients with medically refractory essential tremor, Parkinson's disease, and dystonia. Additionally, DBS is currently being evaluated for the treatment of other psychiatric and neurological disorders, such as obsessive compulsive disorder, major depressive disorder, and epilepsy. DBS has not only been shown to help people by improving their quality of life, it also provides researchers with the unique opportunity to study and understand the human brain. Microelectrode recordings are routinely performed during DBS surgery in order to enhance the precision of anatomical targeting. Firing patterns of individual neurons can therefore be recorded while the subject performs a behavioral task. Early studies using these data focused on descriptive aspects, including firing and burst rates, and frequency modulation 3. More recent studies have focused on cognitive aspects of behavior in relation to neuronal activity 4,5. This article will provide a description of the intra-operative methods used to perform behavioral tasks and record neuronal data with awake patients during DBS cases. Our exposition of the process of acquiring electrophysiological data will illuminate the current scope and limitations of intra-operative human experiments. PMID:21248697

Sheth, Sameer A.; Eskandar, Emad N.

2011-01-01

133

Satellite Television Corporations's DBS system - An update  

NASA Astrophysics Data System (ADS)

In late 1980, a request was made for approval of a direct broadcast satellite (DBS) system. The considered DBS system is to provide nationwide pay-television service on a subscription basis. The system proposed in the application to the Federal Communications Commission would provide three channels of television, using four three-channel satellites. Attention is given to the system configuration, system tradeoffs, a plan of the 1983 Regional Administrative Radio Conference, orbit locations and channel frequencies, satellite status, home equipment status, advanced concepts, and the status of the Las Vegas Broadcast Complex. AIAA Paper 84-0664

Martin, E. R.

134

Probing the Human Brain with Stimulating Electrodes: The Story of Roberts Bartholow's (1874) Experiment on Mary Rafferty  

ERIC Educational Resources Information Center

Roberts Bartholow's 1874 experiment on Mary Rafferty is widely cited as the first demonstration, by direct application of stimulating electrodes, of the motor excitability of the human cerebral cortex. The many accounts of the experiment, however, leave certain questions and details unexamined or unresolved, especially about Bartholow's goals, the…

Harris, Lauren Julius; Almerigi, Jason B.

2009-01-01

135

Direct binary search (DBS) algorithm with constraints  

NASA Astrophysics Data System (ADS)

In this paper, we describe adding constraints to the Direct Binary Search (DBS) algorithm. An example of a useful constraint, illustrated in this paper, is having only one dot per column and row. DBS with such constraints requires greater than two toggles during each trial operation. Implementations of the DBS algorithm traditionally limit operations to either one toggle or swap during each trial. The example case in this paper produces a wrap-around pattern with uniformly distributed ON pixels which will have a pleasing appearance with precisely one ON pixel per each column and row. The algorithm starts with an initial continuous tone image and an initial pattern having only one ON pixel per column and row. The auto correlation function of Human Visual System (HVS) model is determined along with an initial perceived error. Multiple operation pixel error processing during each iteration is used to enforce the one ON pixel per column and row constraint. The constraint of a single ON pixel per column and row is used as an example in this paper. Further modification of the DBS algorithm for other constraints is possible, based on the details given in the paper. A mathematical framework to extend the algorithm to the more general case of Direct Multi-bit Search (DMS) is presented.

Chandu, Kartheek; Stanich, Mikel; Wu, Chai Wah; Trager, Barry

2013-02-01

136

Clinical application of peroneal nerve stimulator system using percutaneous intramuscular electrodes for correction of foot drop in hemiplegic patients.  

PubMed

Objective.? To assess the orthotic effect of a functional electrical stimulation device (Akita Heel Sensor System; AHSS) in the treatment of hemiplegic gait with foot drop. Materials and Methods.? In the AHSS, a heel sensor is attached to a small plastic heel brace, and the peroneal nerve is stimulated via percutaneous intramuscular electrodes. During the swing phase of the hemiplegic gait, the common peroneal nerve is stimulated by the AHSS. Eight patients in chronic stages of hemiplegia participated in this study. Walking speeds and step cadences on a 10-m course were compared between walking with stimulation and walking without stimulation. Results.? Mean walking speed (± SD) was 0.50 ± 0.26 m/sec without stimulation and 0.64 ± 0.31 m/sec with stimulation. The mean percentage increase in walking speed with stimulation was 30.1%. Mean step cadence was 31 ± 7 steps/10 m without stimulation and 27 ± 7 steps/10 m with stimulation. By correcting foot drop, the AHSS significantly increased walking speed and decreased cadence (p < 0.05). Conclusion.? The AHSS can significantly improve walking in hemiplegic patients with foot drop. PMID:22151766

Shimada, Yoichi; Matsunaga, Toshiki; Misawa, Akiko; Ando, Shigeru; Itoi, Eiji; Konishi, Natsuo

2006-10-01

137

Deep Brain Stimulation as a Tool for Improving Cognitive Functioning in Alzheimer’s Dementia: A Systematic Review  

PubMed Central

Deep brain stimulation (DBS) is an established, in selected cases therapeutically effective, non-lesional treatment method delivering current rectangular pulses into dysfunctional brain structures via chronically implanted stimulation electrodes. DBS is a recognized method applied in movement disorders and is increasingly evaluated as a possible therapeutic option for psychiatric diseases such as refractory obsessive-compulsive disorders, Gilles de la Tourette syndrome, major depression, and substance-related addiction. Latest research indicates that DBS may be a method for improving cognitive functions in Alzheimer’s dementia (AD). Translational data in healthy and AD animals appear to support this notion. Nevertheless, many aspects remain unclear, particularly with regard to the optimal target structure. The objective of this review is to present a systematic overview regarding published research on DBS and cognitive functioning in animal and human studies as well as to provide a systematic overview of the feasibility and efficacy of the treatment. We describe three studies investigating the effects of DBS in patients with dementia, using either the fornix or the nucleus basalis of Meynert (NBM) as a target. In total, we identified 25 animal studies with 10 brain structures being targeted: fornix, NBM, anterior caudate nucleus, dorsal striatum, anterior thalamic nucleus, midline thalamic nuclei, central thalamus, lateral hypothalamus, hippocampus (entorhinal cortex, perforant path), and amygdala. Considering the wide and diverse spectrum of targets, we add to this review a supposition about possible underlying mechanisms of operation and recommendations for further research. PMID:24363647

Hardenacke, Katja; Shubina, Elena; Bührle, Christian Philipp; Zapf, Alexandra; Lenartz, Doris; Klosterkötter, Joachim; Visser-Vandewalle, Veerle; Kuhn, Jens

2013-01-01

138

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. PMID:24443448

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

2014-01-01

139

Aggressive behavior as a rare side effect of subthalamic stimulation in Parkinson's disease.  

PubMed

Although deep brain stimulation (DBS) has a well-established position in the treatment of Parkinson's disease (PD), it may be accompanied by different side effects including behavioral changes. We present a patient with advanced PD after bilateral stimulation of the subthalamic nucleus (STN) who developed attacks of aggressive behavior. The patient with a 12 year history of PD underwent the procedure of DBS with one-stage bilateral stereotactic approach using the Leksel G stereotactic frame. For STN identification microrecording technique was applied (5 microelectrodes). Four weeks after surgery STN stimulation was switched on. With increasing the amplitude of stimulation on the right (active contacts 1 and 2) the patient experienced transient episodes of aggression. Change of stimulation mode led to withdrawal of all side effects. We hypothesize that aggression episodes in the patient were caused by stimulation of limbic circuit probable within STN although we cannot exclude simultaneous stimulation of neighboring structures. Aggression episodes are rare side effect of STN-DBS, nevertheless they may be expected in more posteromedial placement of the electrode within STN. The presented case extends the evidence for non-motor functions of STN and highlights its role as an integrating structure within the basal ganglia system. PMID:24564255

Papu?, Ewa; Trojanowski, Tomasz; Obsza?ska, Katarzyna; Stelmasiak, Zbigniew

2015-04-01

140

47 CFR 101.1440 - MVDDS protection of DBS.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false MVDDS protection of DBS. 101.1440 Section 101.1440 Telecommunication...Band § 101.1440 MVDDS protection of DBS. (a) An MVDDS licensee shall not...EPFD from its transmitting antenna at all DBS customers of record locations is...

2010-10-01

141

Deep brain stimulation of the nucleus accumbens shell attenuates cue-induced reinstatement of both cocaine and sucrose seeking in rats.  

PubMed

Stimuli previously associated with drug taking can become triggers that can elicit craving and lead to relapse of drug-seeking behavior. Here, we examined the influence of deep brain stimulation (DBS) in the nucleus accumbens shell on cue-induced reinstatement of cocaine seeking, an animal model of relapse. Rats were allowed to self-administer cocaine (0.254mg, i.v.) for 2h daily for 21 days, with each infusion of cocaine being paired with a cue light. After 21 days of self-administration, cocaine-taking behavior was extinguished by replacing cocaine with saline in the absence of the cue light. Next, during the reinstatement phase, DBS was administered bilaterally into the nucleus accumbens shell through bipolar stainless steel electrodes immediately prior to re-exposure to cues previously associated with cocaine reinforcement. DBS continued throughout the 2h reinstatement session. Parallel studies examined the influence of accumbens shell DBS on reinstatement induced by cues previously associated with sucrose reinforcement. Results indicated that DBS of the nucleus accumbens shell significantly attenuated cue-induced reinstatement of cocaine and sucrose seeking. Together, these results indicate that DBS of the accumbens shell disrupts cue-induced reinstatement associated with both a drug and a natural reinforcer. PMID:25529183

Guercio, Leonardo A; Schmidt, Heath D; Pierce, R Christopher

2015-03-15

142

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

PubMed Central

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

143

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

144

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

PubMed Central

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

145

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. PMID:22787444

Eusebio, Alexandre; Cagnan, Hayriye; Brown, Peter

2012-01-01

146

Chronic stress-like syndrome as a consequence of medial site subthalamic stimulation in Parkinson's disease.  

PubMed

Considering the functional organization of the subthalamic nucleus (STN), we hypothesized that subthalamic deep brain stimulation (STN-DBS) in Parkinson's disease might have a differential impact on the hypothalamic-pituitary-adrenal axis in relation to the position of active stimulating contact within the STN. In addition, we searched for any STN-DBS-related morning plasma cortisol changes in association with postoperative anxiety and weight gain. A plasma cortisol measurement was performed on the day of initiation of bilateral STN-DBS and repeated after 1 and 17 months in twenty patients with advanced Parkinson's disease. The body weight change and anxiety scores following the implantation were assessed as well. The electrode positions in the STN were determined on T1-weighted magnetic resonance images. After initiation of stimulation, cortisol levels significantly decreased and the cortisol changes after 1 and 17 months strongly correlated with the position of active contact in the subthalamic area. Patients with at least one contact located more medially in the STN experienced a significantly greater decrease of cortisol than those with one or both active contacts more laterally. Furthermore, the lower cortisol levels were strongly associated with higher trait anxiety and weight gain. These changes mimicked the effects of chronic stress and suggest the disturbing impact of STN-DBS on limbic and motivational systems. PMID:25554999

R?ži?ka, Filip; Jech, Robert; Nováková, Lucie; Urgošík, Dušan; Bezdí?ek, Ond?ej; Vymazal, Josef; R?ži?ka, Evžen

2015-02-01

147

Intracranial electrode implantation produces regional neuroinflammation and memory deficits in rats  

PubMed Central

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 one week or eight weeks post implantation and processed for in vitro autoradiography with [3H]PK11195, an established marker of microglial activation. Memory function was assessed by the novel object recognition test (ORT) before surgery and two and eight weeks after surgery. Electrode implantation produced region-dependent changes in ligand binding density in the implanted brains at one week as well as eight weeks post implantation. Cortical regions showed more intense and widespread neuroinflammation than striatal or thalamic structures. Furthermore, implanted animals showed deficits in ORT performance two and eight 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. PMID:20026042

Hirshler, Yafit (Kuttner); Polat, Uri; Biegon, Anat

2009-01-01

148

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. PMID:12588913

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

2003-01-01

149

A Groove Technique for Securing an Electrode Connector on the Cranial Bone: Case Analysis of Efficacy  

PubMed Central

Objective A groove technique for securing an electrode connector was described as an alternative surgical technique in deep brain stimulation (DBS) surgery to avoid electrode connector-related complications, such as skin erosion, infection, and migration. Methods We retrospectively reviewed 109 patients undergoing one of two techniques; the standard technique (52 patients using 104 electrodes) and the groove technique (57 patients using 109 electrodes) for securing the electrode connector in DBS surgery, regardless of patient disease. In the standard percutaneous tunneling technique, the connector was placed on the vertex of the cranial surface. The other technique, so called the groove technique, created a groove (about 4 cm long, 8 mm wide) in the cranial bone at the posterior parietal area. Wound erosion and migration related to the connectors were compared between the two techniques. Results The mean follow-up period was 73 months for the standard method and 46 months for the groove technique. Connector-related complications were observed in three patients with the groove technique and in seven patients with the standard technique. Wound erosion at the connector sites per electrode was one (0.9%) with the groove technique and six (5.8%) with the standard technique. This difference was statistically significant. The electrode connector was migrated in two patients with the groove technique and in one patient with the standard technique. Conclusions The groove technique, which involves securing an electrode using a groove in the cranial bone at the posterior parietal area, offers an effective and safe method to avoid electrode connector-related complications during DBS surgery. PMID:25328650

Lee, Sung-Woo; Seo, Il; Kim, Ho-Sang; Kim, Jeong-Ho; Kim, Yun-Suk

2014-01-01

150

Optimizing the delivery of deep brain stimulation using electrophysiological atlases and an inverse modeling approach  

NASA Astrophysics Data System (ADS)

The use of deep brain stimulation (DBS) for the treatment of neurological movement degenerative disorders requires the precise placement of the stimulating electrode and the determination of optimal stimulation parameters that maximize symptom relief (e.g. tremor, rigidity, movement difficulties, etc.) while minimizing undesired physiological side-effects. This study demonstrates the feasibility of determining the ideal electrode placement and stimulation current amplitude by performing a patient-specific multivariate optimization using electrophysiological atlases and a bioelectric finite element model of the brain. Using one clinical case as a preliminary test, the optimization routine is able to find the most efficacious electrode location while avoiding the high side-effect regions. Future work involves optimization validation clinically and improvement to the accuracy of the model.

Sun, Kay; Pallavaram, Srivatsan; Rodriguez, William; D'Haese, Pierre-Francois; Dawant, Benoit M.; Miga, Michael I.

2012-02-01

151

Nucleus Accumbens Deep Brain Stimulation Results in Insula and Prefrontal Activation: A Large Animal fMRI Study  

PubMed Central

Background Deep Brain Stimulation (DBS) of the nucleus accumbens (NAc) has previously been investigated clinically for the treatment of several psychiatric conditions, including obsessive-compulsive disorder and treatment resistant depression. However, the mechanism underlying the therapeutic benefit of DBS, including the brain areas that are activated, remains largely unknown. Here, we utilized 3.0 T functional Magnetic Resonance Imaging (fMRI) changes in Blood Oxygenation Level-Dependent (BOLD) signal to test the hypothesis that NAc/internal capsule DBS results in global neural network activation in a large animal (porcine) model Methods Animals (n?=?10) were implanted in the NAc/internal capsule with DBS electrodes and received stimulation (1, 3, and 5 V, 130 Hz, and pulse widths of 100 and 500 µsec). BOLD signal changes were evaluated using a gradient echo-echo planar imaging (GRE-EPI) sequence in 3.0 T MRI. We used a normalized functional activation map for group analysis and applied general linear modeling across subjects (FDR<0.001). The anatomical location of the implanted DBS lead was confirmed with a CT scan Results We observed stimulation-evoked activation in the ipsilateral prefrontal cortex, insula, cingulate and bilateral parahippocampal region along with decrease in BOLD signal in the ipsilateral dorsal region of the thalamus. Furthermore, as the stimulation voltage increased from 3 V to 5 V, the region of BOLD signal modulation increased in insula, thalamus, and parahippocampal cortex and decreased in the cingulate and prefrontal cortex. We also demonstrated that right and left NAc/internal capsule stimulation modulates identical areas ipsilateral to the side of the stimulation Conclusions Our results suggest that NAc/internal capsule DBS results in modulation of psychiatrically important brain areas notably the prefrontal cortex, cingulate, and insular cortex, which may underlie the therapeutic effect of NAc DBS in psychiatric disorders. Finally, our fMRI setup in the large animal may be a useful platform for translational studies investigating the global neuromodulatory effects of DBS PMID:23441210

Knight, Emily J.; Min, Hoon-Ki; Hwang, Sun-Chul; Marsh, Michael P.; Paek, Seungleal; Kim, Inyong; Felmlee, Joel P.; Abulseoud, Osama A.; Bennet, Kevin E.; Frye, Mark A.; Lee, Kendall H.

2013-01-01

152

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

NASA Astrophysics Data System (ADS)

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.

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

153

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

154

Delayed and lasting effects of deep brain stimulation on locomotion in Parkinson's disease  

NASA Astrophysics Data System (ADS)

Parkinson's disease (PD) is a neurodegenerative disorder characterized by a variety of motor signs affecting gait, postural stability, and tremor. These symptoms can be improved when electrodes are implanted in deep brain structures and electrical stimulation is delivered chronically at high frequency (>100 Hz). Deep brain stimulation (DBS) onset or cessation affects PD signs with different latencies, and the long-term improvements of symptoms affecting the body axis and those affecting the limbs vary in duration. Interestingly, these effects have not been systematically analyzed and modeled. We compare these timing phenomena in relation to one axial (i.e., locomotion) and one distal (i.e., tremor) signs. We suggest that during DBS, these symptoms are improved by different network mechanisms operating at multiple time scales. Locomotion improvement may involve a delayed plastic reorganization, which takes hours to develop, whereas rest tremor is probably alleviated by an almost instantaneous desynchronization of neural activity in subcortical structures. Even if all PD patients develop both distal and axial symptoms sooner or later, current computational models of locomotion and rest tremor are separate. Furthermore, a few computational models of locomotion focus on PD and none exploring the effect of DBS was found in the literature. We, therefore, discuss a model of a neuronal network during DBS, general enough to explore the subcircuits controlling locomotion and rest tremor simultaneously. This model accounts for synchronization and plasticity, two mechanisms that are believed to underlie the two types of symptoms analyzed. We suggest that a hysteretic effect caused by DBS-induced plasticity and synchronization modulation contributes to the different therapeutic latencies observed. Such a comprehensive, generic computational model of DBS effects, incorporating these timing phenomena, should assist in developing a more efficient, faster, durable treatment of distal and axial signs in PD.

Beuter, Anne; Modolo, Julien

2009-06-01

155

Thalamic Deep Brain Stimulation for Parkinson's Disease Tremor  

Microsoft Academic Search

\\u000a Thalamic deep brain stimulation (DBS) was introduced for the treatment of Parkinson's disease (PD) tremor and essential tremor\\u000a (ET) in the late 1980s. Its remarkable success for these indications was followed by the introduction of DBS in other brain\\u000a targets for the treatment of PD and dystonia. With the advent of subthalamic DBS for PD, the use of thalamic DBS

Daniel Tarsy; Efstathios Papavassiliou; Kelly E. Lyons; Rajesh Pahwa

156

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

157

Deep Brain Stimulation for Advanced Parkinson's Disease  

Microsoft Academic Search

Deep brain stimulation (DBS) is a new and promising technique for the treatment of movement disorders. Medically intractable Parkinson's disease (PD) is one of the most common indications for DBS. There are three possible subcortical targets for PD, depending on the symptomatology (ie, the motor subdivision of the thalamus, the globus pallidus internus, the subthalamic nucleus [STN]). Thalamic stimulation has

Debra L. Byrd; William J. Marks; Philip A. Starr

2000-01-01

158

Assessing the direct effects of deep brain stimulation using embedded axon models  

NASA Astrophysics Data System (ADS)

To better understand the spatial extent of the direct effects of deep brain stimulation (DBS) on neurons, we implemented a geometrically realistic finite element electrical model incorporating anisotropic and inhomogenous conductivities. The model included the subthalamic nucleus (STN), substantia nigra (SN), zona incerta (ZI), fields of Forel H2 (FF), internal capsule (IC) and Medtronic 3387/3389 electrode. To quantify the effects of stimulation, we extended previous studies by using multi-compartment axon models with geometry and orientation consistent with anatomical features of the brain regions of interest. Simulation of axonal firing produced a map of relative changes in axonal activation. Voltage-controlled stimulation, with clinically typical parameters at the dorso-lateral STN, caused axon activation up to 4 mm from the target. This activation occurred within the FF, IC, SN and ZI with current intensities close to the average injected during DBS (3 mA). A sensitivity analysis of model parameters (fiber size, fiber orientation, degree of inhomogeneity, degree of anisotropy, electrode configuration) revealed that the FF and IC were consistently activated. Direct activation of axons outside the STN suggests that other brain regions may be involved in the beneficial effects of DBS when treating Parkinsonian symptoms.

Sotiropoulos, Stamatios N.; Steinmetz, Peter N.

2007-06-01

159

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

160

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. PMID:24971060

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

2014-01-01

161

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

162

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

163

Electrochemomechanical deformation (ECMD) of PPyDBS in free standing film formation and trilayer designs  

NASA Astrophysics Data System (ADS)

An investigation is reported into the electrochemomechanical deformation (ECMD) of polypyrrole (PPy) doped with dodecylbenzenesulfonate (DBS) in the form of freestanding films and deposited onto conductive substrates (chemically fixed poly-3,4-(ethylenedioxythiophene, PEDOT) based on PVdF (poly(vinylidenefluoride)). Linear actuation has been achieved starting from a trilayer bending actuator design with a stretchable middle layer. To allow evaluation of the proposed design, commercially available PVdF membranes were chosen as model material. For bending trilayer functionality, electronic separation of both electrode layers is essential, but in order to obtain linear actuation, the CP layers on either side are connected to form a single working electrode. The PPyDBS free standing films and PPyDBS deposited on PEDOT-PVdF-PEDOT were investigated by electrochemical methods (cyclic voltammetry, square wave potentials) in a 4-methyl-1,3-dioxolan-2-one (propylene carbonate, PC) solution of tetrabutylammonium trifluoromethanesulfonate (TBACF3SO3). This study also presents a novel method of utilizing scanning ion-conductance microscopy (SICM) to accurately examine the electrochemical redox behavior of the surface layer of the linear actuator using a micropipette tip.

Aydemir, Nihan; Tamm, Tarmo; Travas-Sejdic, Jadranka; Kilmartin, Paul A.; Aabloo, Alvo; Kiefer, Rudolf

2014-03-01

164

Atlas of the muscle motor points for the lower limb: implications for electrical stimulation procedures and electrode positioning.  

PubMed

The aim of the study was to investigate the uniformity of the muscle motor point location for lower limb muscles in healthy subjects. Fifty-three subjects of both genders (age range: 18-50 years) were recruited. The muscle motor points were identified for the following ten muscles of the lower limb (dominant side): vastus medialis, rectus femoris, and vastus lateralis of the quadriceps femoris, biceps femoris, semitendinosus, and semimembranosus of the hamstring muscles, tibialis anterior, peroneus longus, lateral and medial gastrocnemius. The muscle motor point was identified by scanning the skin surface with a stimulation pen electrode and corresponded to the location of the skin area above the muscle in which an electrical pulse evoked a muscle twitch with the least injected current. For each investigated muscle, 0.15 ms square pulses were delivered through the pen electrode at low current amplitude (<10 mA) and frequency (2 Hz). 16 motor points were identified in the 10 investigated muscles of almost all subjects: 3 motor points for the vastus lateralis, 2 motor points for rectus femoris, vastus medialis, biceps femoris, and tibialis anterior, 1 motor point for the remaining muscles. An important inter-individual variability was observed for the position of the following 4 out of 16 motor points: vastus lateralis (proximal), biceps femoris (short head), semimembranosus, and medial gastrocnemius. Possible implications for electrical stimulation procedures and electrode positioning different from those commonly applied for thigh and leg muscles are discussed. PMID:21796408

Botter, Alberto; Oprandi, Gianmosè; Lanfranco, Fabio; Allasia, Stefano; Maffiuletti, Nicola A; Minetto, Marco Alessandro

2011-10-01

165

Habituation and rebound to thalamic deep brain stimulation in long-term management of tremor associated with demyelinating neuropathy.  

PubMed

Some patients may experience tolerance to chronic ventral intermediate (ViM) thalamic deep brain stimulation (DBS), which may include habituation (loss of sustained tremor control over weeks to days after an adjustment) and rebound (a temporary increase in tremor intensity after stopping DBS). We observed an association between these efficacy limiting phenomena with co-morbid demyelinating sensorimotor peripheral neuropathy (MRT-PN). The clinical and treatment characteristics of neuropathy and tremor pre- and post-DBS are described through retrospective chart review of five patients with MRT-PN. Programming strategies (number of programming visits/implant years and number of major parameter changes/electrode) were compared in MRT-PN patients to a group of seven ET patients without neuropathy, who had > 4 years continuous follow-up. The presence of habituation and rebound were recorded. All MRT-PN patients had initial good response to DBS followed by habituation and/or rebound of tremor control, some asymmetrically. Compared to ET without neuropathy (mean follow-up 5.83 ± 0.78 years), MRT-PN patients (mean follow-up 4.90 ± 3.73 years) required more programming visits/year (p = 0.12) and major parameter changes/electrode/implant year (p = 0.03). The presence of neuropathy may alter tremor characteristics and result in temporary re-setting of thalamic oscillatory drive after DBS in MRT-PN patients. Clinicians should be aware of the risk for tolerance to DBS in MRT-PN and patients should be counseled about possible suboptimal sustained tremor control. PMID:24552416

Patel, Neepa; Ondo, William; Jimenez-Shahed, Joohi

2014-12-01

166

Supporting clinical decision making during deep brain stimulation surgery by means of a stochastic dynamical model  

NASA Astrophysics Data System (ADS)

Objective. During deep brain stimulation (DBS) surgery for the treatment of advanced Parkinson's disease (PD), microelectrode recording (MER) in conjunction with functional stimulation techniques are commonly applied for accurate electrode implantation. However, the development of automatic methods for clinical decision making has to date been characterized by the absence of a robust single-biomarker approach. Moreover, it has only been restricted to the framework of MER without encompassing intraoperative macrostimulation. Here, we propose an integrated series of novel single-biomarker approaches applicable to the entire electrophysiological procedure by means of a stochastic dynamical model. Approach. The methods are applied to MER data pertinent to ten DBS procedures. Considering the presence of measurement noise, we initially employ a multivariate phase synchronization index for automatic delineation of the functional boundaries of the subthalamic nucleus (STN) and determination of the acceptable MER trajectories. By introducing the index into a nonlinear stochastic model, appropriately fitted to pre-selected MERs, we simulate the neuronal response to periodic stimuli (130 Hz), and examine the Lyapunov exponent as an indirect indicator of the clinical effectiveness yielded by stimulation at the corresponding sites. Main results. Compared with the gold-standard dataset of annotations made intraoperatively by clinical experts, the STN detection methodology demonstrates a false negative rate of 4.8% and a false positive rate of 0%, across all trajectories. Site eligibility for implantation of the DBS electrode, as implicitly determined through the Lyapunov exponent of the proposed stochastic model, displays a sensitivity of 71.43%. Significance. The suggested comprehensive method exhibits remarkable performance in automatically determining both the acceptable MER trajectories and the optimal stimulation sites, thereby having the potential to accelerate precise target finalization during DBS surgery for PD.

Karamintziou, Sofia D.; Tsirogiannis, George L.; Stathis, Pantelis G.; Tagaris, George A.; Boviatsis, Efstathios J.; Sakas, Damianos E.; Nikita, Konstantina S.

2014-10-01

167

Anterior thalamus deep brain stimulation at high current impairs memory in rats.  

PubMed

Deep brain stimulation (DBS) of the anterior thalamic nucleus (AN), an important relay in the circuitry of memory, is currently being proposed as a treatment for epilepsy. Despite the encouraging results with the use of this therapy, potential benefits and adverse effects are yet to be determined. We show that AN stimulation at relatively high current disrupted the acquisition of contextual fear conditioning and impaired performance on a spatial alternating task in rats. This has not been observed at parameters generating a charge density that approximated the one used in clinical practice. At settings that impaired behavior, AN stimulation induced a functional depolarization block nearby the electrode, increased c-Fos expression in cerebral regions projecting to and receiving projections from the AN, and influenced hippocampal activity. This suggests that complex mechanisms might be involved in the effects of AN DBS, including a local target inactivation and the modulation of structures at a distance. Though translating data from animals to humans has to be considered with caution, our study underscores the need for carefully monitoring memory function while selecting stimulation parameters during the clinical evaluation of AN DBS. PMID:20558163

Hamani, Clement; Dubiela, Francisco P; Soares, Juliana C K; Shin, Damian; Bittencourt, Simone; Covolan, Lucience; Carlen, Peter L; Laxton, Adrian W; Hodaie, Mojgan; Stone, Scellig S D; Ha, Yoon; Hutchison, William D; Lozano, Andres M; Mello, Luiz E; Oliveira, Maria Gabriela M

2010-09-01

168

Foundations of recommender system for STN localization during DBS surgery  

E-print Network

Foundations of recommender system for STN localization during DBS surgery in Parkinson's patients) treatment of Parkin- son disease, the target of the surgery is the subthalamic nucleus (STN). As STN. Keywords: Parkinson's disease, DBS, STN, FFT, DWT, RMS, LFB, HFB, Hierarchical clustering Introduction

Ras, Zbigniew W.

169

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. PMID:24724036

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

2014-01-01

170

Lessons Learned from Open-label Deep Brain Stimulation for Tourette Syndrome: Eight Cases over 7 Years  

PubMed Central

Background Deep brain stimulation (DBS) remains an experimental but promising treatment for patients with severe refractory Gilles de la Tourette syndrome (TS). Controversial issues include the selection of patients (age and clinical presentation), the choice of brain targets to obtain optimal patient-specific outcomes, and the risk of surgery- and stimulation-related serious adverse events. Methods This report describes our open-label experience with eight patients with severe refractory malignant TS treated with DBS. The electrodes were placed in the midline thalamic nuclei or globus pallidus, pars internus, or both. Tics were clinically assessed in all patients pre- and postoperatively using the Modified Rush Video Protocol and the Yale Global Tic Severity Scale (YGTSS). Results Although three patients had marked postoperative improvement in their tics (>50% improvement on the YGTSS), the majority did not reach this level of clinical improvement. Two patients had to have their DBS leads removed (one because of postoperative infection and another because of lack of benefit). Discussion Our clinical experience supports the urgent need for more data and refinements in interventions and outcome measurements for severe, malignant, and medication-refractory TS. Because TS is not an etiologically homogenous clinical entity, the inclusion criteria for DBS patients and the choice of brain targets will require more refinement. PMID:24255802

Motlagh, Maria G.; Smith, Megan E.; Landeros-Weisenberger, Angeli; Kobets, Andrew J.; King, Robert A.; Miravite, Joan; de Lotbinière, Alain C. J.; Alterman, Ron L.; Mogilner, Alon Y.; Pourfar, Michael H.; Okun, Michael S.; Leckman, James F.

2013-01-01

171

Effect of MR Distortion on Targeting for Deep-Brain Stimulation  

PubMed Central

Deep-brain stimulation (DBS) surgery involves placing electrodes within specific deep-brain target nuclei. Surgeons employ MR imaging for preoperative selection of targets and computed tomography (CT) imaging for designing stereotactic frames used for intraoperative placement of electrodes at the targets. MR distortion may contribute to target-selection error in the MR scan and also to MR-CT registration error, each of which contributes to error in electrode placement. In this paper, we analyze the error contributed by the MR distortion to the total DBS targeting error. Distortion in conventional MR scans, both T1 and T2 weighted, were analyzed for six bilateral DBS patients in the typical areas of brain using typical scans on a 3-T clinical scanner. Mean targeting error due to MR distortion in T2 was found to be 0.07 ± 0.025 mm with a maximum of 0.13 mm over 12 targets; error in the T1 images was smaller by 4%. PMID:20388592

Balachandran, Ramya; Welch, E. Brian; Dawant, Benoit M.; Fitzpatrick, J. Michael

2011-01-01

172

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

173

Relations among threshold, spike height, electrode distance, and conduction velocity in electrical stimulation of certain medullospinal neurons.  

PubMed

This report describes how the threshold for extracellular, electrical stimulation of cell bodies in the rat's rostromedial medulla depends on the distance to the stimulating electrode. A monopolar microelectrode both delivered current pulses near medullospinal neurons and, after decay of the stimulus artifact, detected whether an orthodromic spike had occurred by collision of that spike with a suitably timed antidromic spike initiated at the thoracic spinal cord. The liminal current and the height of antidromic spikes were noted at a series of vertical electrode positions. Regression analysis was performed to determine whether threshold and the inverse of peak-to-peak spike height varied more as the radial distance or its square. The square relationship provided a much better fit for threshold and a marginally better fit for the inverse of spike height. The spatial decline in excitability (K2) averaged 859 microA/mm2, falling within the range of values found for fibers and cell bodies in other studies. The constant of spatial decline in spike height (C2) in millivolts per square millimeter was positively correlated with K2. Both C2 and K2 were negatively correlated with conduction velocity. From threshold distance curves fitted by regression analysis, the mean separation of sites of spike maxima and threshold minima along each electrode path was 16 micron; the estimated distance from these sites to, respectively, the loci of spike generation and spike excitation were positively correlated and similar. The variation of C2 and K2 with conduction velocity may be due either to an influence of the size and shape of the dendritic tree on the spatial decrement of excitability and spike height or to a confounding in the studied equations of the space-independent effect of the size of a cell body on spike height and excitability. PMID:6726321

Hentall, I D; Zorman, G; Kansky, S; Fields, H L

1984-05-01

174

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

175

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

NASA Astrophysics Data System (ADS)

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 to the time of the surgery. We performed brain shift analysis on nine patients that underwent DBS surgery using a 3D non-rigid registration algorithm. The registration algorithm automatically aligns the pre-operative and the post-operative 3D MRI scans and provides the shift vectors over the entire brain. The images were first aligned rigidly and then non-rigidly registered with an algorithm based on thin plate splines and maximization of the normalized mutual information. Brain shift of up to 8 mm was recorded in the nine subjects, which is significant given that the size of the targets in the DBS surgery is a few millimeters.

Khan, Muhammad F.; Mewes, Klaus; Gross, Robert; Škrinjar, Oskar

2007-03-01

176

Possible therapeutic effects of transcutaneous electrical stimulation via concentric ring electrodes  

E-print Network

noninvasively via transcranial magnetic stimula- tion (TMS), transcranial direct current stimulation (tDCS it has been shown that tDCS decreased epileptic dis- charges. However, the decrease in seizures due to tDCS

Besio, Walter G.

177

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

178

GPi-DBS in Huntington's disease: results on motor function and cognition in a 72-year-old case.  

PubMed

Huntington's disease (HD) produces debilitating motor abnormalities that are poorly responsive to medical therapy. Deep brain stimulation (DBS) of the posteroventral globus pallidus internus (GPi) may offer a treatment option for patients with diskinetic phenotype and minimal cognitive impairment, but its role in the management of HD remains unclear and to date only two cases have been reported. We report the outcome of GPi-DBS in a 72-year-old man with HD. Stimulation at 130 Hz caused a rapid amelioration of chorea producing the worsening of bradykinesia, whereas 40 Hz stimulation (maintaining constant the total electrical energy delivered) improved chorea while preserving the ability to walk. At 1-year follow-up, chorea has completely disappeared; however, the patient was unable to stand and walk. The cognitive profile showed a progressive deterioration, with an extension of deficit from the mainly dysexecutive alterations at baseline to a more diffused cognitive deterioration. PMID:18512756

Fasano, Alfonso; Mazzone, Paolo; Piano, Carla; Quaranta, Davide; Soleti, Francesco; Bentivoglio, Anna Rita

2008-07-15

179

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. PMID:22291623

Pizzolato, Gilberto; Mandat, Tomasz

2012-01-01

180

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

181

Flexible Nerve Stimulation Electrode with Iridium Oxide Sputtered on Liquid Crystal Polymer  

PubMed Central

Current electrode designs require flexible substrates that absorb little moisture and provide large charge injection capability. Sputtered iridium oxide films have superior charge injection capabilities versus noble metals and can adhere to various substrates. Liquid crystal polymers (LCP) have very little water absorption compared to other flexible substrates. Therefore, the combination of sputtered iridium oxide film on liquid crystal polymer substrate was studied using 50Hz, 100?s duration, 10mA biphasic current waveforms for 700 hours at 67°C in bicarbonate buffer saline. Scanning electron micrograph (SEM) analysis showed no delamination and approximately 1% of electrode material was lost to the bicarbonate buffer. The charge injection limit and the cathodic charge storage capacity within the water window were 4.6 +/? 1.0mC/cm2 and 31.5 +/? 6.6mC/cm2 respectively. Additional electrochemical analysis revealed significant charge imbalance attributed to oxygen reduction within the water window. These results, along with the flexible, chemically inert, biocompatible substrate, indicate that sputtered iridium oxide films on liquid crystal polymer could become the method of choice for flexible substrate nerve electrodes. PMID:19224713

Wang, Kevin; Liu, Chung-Chiun; Durand, Dominique M.

2009-01-01

182

Flexible nerve stimulation electrode with iridium oxide sputtered on liquid crystal polymer.  

PubMed

Current electrode designs require flexible substrates that absorb little moisture and provide large charge injection capability. Sputtered iridium oxide films have superior charge injection capabilities versus noble metals and can adhere to various substrates. Liquid crystal polymers (LCPs) have very little water absorption compared to other flexible substrates. Therefore, the combination of sputtered iridium oxide film on LCP substrate was studied using 50 Hz, 100 micros duration, and 10 mA biphasic current waveforms for 700 h at 67 degrees C in bicarbonate buffer saline. Scanning electron micrograph analysis showed no delamination and approximately 1% of electrode material was lost to the bicarbonate buffer. The charge injection limit and the cathodic charge storage capacity within the water window were 4.6 +/- 1.0 and 31.5 +/-6.6 mC/cm2, respectively. Additional electrochemical analysis revealed significant charge imbalance attributed to oxygen reduction within the water window. These results, along with the flexible, chemically inert, and biocompatible substrate, indicate that sputtered iridium oxide films on LCP could become the method of choice for flexible substrate nerve electrodes. PMID:19224713

Wang, Kevin; Liu, Chung-Chiun; Durand, Dominique M

2009-01-01

183

Current clinical application of deep-brain stimulation for essential tremor  

PubMed Central

Background Deep-brain stimulation (DBS) is an established treatment for medically refractory essential tremor (ET). This article reviews the current evidence supporting the efficacy and safety of DBS targets, including the ventral intermediate (VIM) nucleus and posterior subthalamic area (PSA) in treatment of ET. Methods A structured PubMed search was performed through December 2012 with keywords “deep brain stimulation (DBS),” “essential tremor (ET),” “ventral intermediate (VIM) nucleus,” “posterior subthalamic area (PSA),” “safety,” and “efficacy.” Results Based on level IV evidence, both VIM and PSA DBS targets appear to be safe and efficacious in ET patients in tremor reduction and improving activities of daily living, though the literature on PSA DBS is limited in terms of bilateral stimulation and long-term follow-up. DBS-related adverse effects are typically mild and stimulation-related. Hardware-related complications after DBS may not be uncommon, and often require additional surgical procedures. Few studies assessed quality-of-life and cognition outcomes in ET patients undergoing DBS stimulation. Conclusion DBS appears to be a safe and effective treatment for medically refractory ET. More systematic studies comparing VIM and PSA targets are needed to ascertain the most safe and effective DBS treatment for medically refractory ET. More research is warranted to assess quality-of-life and cognition outcomes in ET patients undergoing DBS. PMID:24324335

Chopra, Amit; Klassen, Bryan T; Stead, Matt

2013-01-01

184

The Effects of Bilateral Subthalamic Nucleus Stimulation on Cognitive and Neuropsychiatric Functions in Parkinson’s Disease: A Case-Control Study #  

PubMed Central

Introduction Parkinson's disease is one of the most disabling diseases which by electrode implantation and stimulation of subthalamic nucleus (STN), much progress has been made in the treatment of drug resistant patient. This new method of neurosurgery may have some neuropsychological side effects on the patients. The main aim of this study is to evaluate the effects of this kind of treatment on the different neuropsychological aspect of patients. Methods The case-control study designed for comparing two groups of patients with Parkinson's disease. Thirty patients, who underwent electrode implantation and Deep Brain Stimulation (DBS), compare with 60 patients treated with antiparkinson's drugs. These two groups matched in age, sex, Parkinson's disease duration and Parkinson's severity scores. Measurements: the UPDR scale was used to assess the severity of the Parkinson's severity. Beck Depression Inventory questionnaire (BDI) and Hamilton Anxiety Rating Scale questionnaire (HARS) were used to evaluate the depression and anxiety consequences of DBS. Mini Mental Status Examination (MMSE) and Clock Drawing Test (CDT) were used to evaluate the cognitive and executive function of the study subjects. Results Patients with STN stimulation showed lower level of anxiety and depression, however, the cognitive status were more deteriorated in study subjects than control group. Discussion Patient with DBS surgery have to be followed up for neuropsychiatric symptoms particularly for the cognitive deterioration in long term period. PMID:25337350

Mahdavi, Reza; Malakouti, Seyed Kazem; Shahidi, Gholam Ali; Parvaresh-Rizi, Mansour

2013-01-01

185

Surface-patterned electrode bioreactor for electrical stimulation Nina Tandon,ae  

E-print Network

junctions. Introduction Cardiac tissue engineering utilizes cardiogenic cells, structural templates and human adipose derived stem cells. Over 6 days of culture with electrical stimulation (2 ms duration, 1, elongation and alignment, and adipose derived stem cells exhibited higher numbers of Connexin-43-composed gap

Voldman, Joel

186

A Multiple Electrode Scheme for Optimal Non-Invasive Electrical Stimulation  

E-print Network

site is identified by a clinician. I. INTRODUCTION Transcranial direct current stimulation (tDCS], Parkinson's dis- ease [4], and motor and speech rehabilitation after stroke [5], [6]. Moreover, tDCS has been shown to improve cognitive function, specifically memory, in healthy subjects [7], [8]. A basic tDCS

Parra, Lucas C.

187

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. PMID:24244479

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

2013-01-01

188

An inexpensive, charge-balanced rodent deep brain stimulation device: a step-by-step guide to its procurement and construction  

PubMed Central

Background Despite there being a relatively large number of methods papers which detail specifically the development of stimulation devices, only a small number of reports involve the application of these devices in freely moving animals. To date multiple preclinical neural stimulators have been designed and described but have failed to make an impact on the methods employed by the majority of laboratories studying DBS. Thus, the overwhelming majority of DBS studies are still performed by tethering the subject to an external stimulator. We believe that the low adoption rate of previously described methods is a result of the complexity of replicating and implementing these methods. New Method Here were describe both the design and procurement of a simple and inexpensive stimulator designed to be compatible with commonly used, commercially available electrodes (Plastics 1). Results This system is initially programmable in frequency, pulsewidth and current amplitude, and delivers biphasic, charge-balanced output to two independent electrodes. Comparison with Existing Method(s) It is easy to implement requiring neither subcutaneous implantation or custom-made electrodes and has been optimized for either direct mounting to the head or for use with rodent jackets. Conclusions This device is inexpensive and universally accessible, facilitating high throughput, low cost, long-term rodent deep brain stimulation experiments. PMID:23954265

Ewing, Samuel G.; Lipski, Witold J.; Grace, Anthony A.; Winter, Christine

2013-01-01

189

Development of the Mayo Investigational Neuromodulation Control System: toward a closed-loop electrochemical feedback system for deep brain stimulation  

PubMed Central

Object Conventional deep brain stimulation (DBS) devices continue to rely on an open-loop system in which stimulation is independent of functional neural feedback. The authors previously proposed that as the foundation of a DBS “smart” device, a closed-loop system based on neurochemical feedback, may have the potential to improve therapeutic outcomes. Alterations in neurochemical release are thought to be linked to the clinical benefit of DBS, and fast-scan cyclic voltammetry (FSCV) has been shown to be effective for recording these evoked neurochemical changes. However, the combination of FSCV with conventional DBS devices interferes with the recording and identification of the evoked analytes. To integrate neurochemical recording with neurostimulation, the authors developed the Mayo Investigational Neuromodulation Control System (MINCS), a novel, wirelessly controlled stimulation device designed to interface with FSCV performed by their previously described Wireless Instantaneous Neurochemical Concentration Sensing System (WINCS). Methods To test the functionality of these integrated devices, various frequencies of electrical stimulation were applied by MINCS to the medial forebrain bundle of the anesthetized rat, and striatal dopamine release was recorded by WINCS. The parameters for FSCV in the present study consisted of a pyramidal voltage waveform applied to the carbon-fiber microelectrode every 100 msec, ramping between ?0.4 V and +1.5 V with respect to an Ag/AgCl reference electrode at a scan rate of either 400 V/sec or 1000 V/sec. The carbon-fiber microelectrode was held at the baseline potential of ?0.4 V between scans. Results By using MINCS in conjunction with WINCS coordinated through an optic fiber, the authors interleaved intervals of electrical stimulation with FSCV scans and thus obtained artifact-free wireless FSCV recordings. Electrical stimulation of the medial forebrain bundle in the anesthetized rat by MINCS elicited striatal dopamine release that was time-locked to stimulation and increased progressively with stimulation frequency. Conclusions Here, the authors report a series of proof-of-principle tests in the rat brain demonstrating MINCS to be a reliable and flexible stimulation device that, when used in conjunction with WINCS, performs wirelessly controlled stimulation concurrent with artifact-free neurochemical recording. These findings suggest that the integration of neurochemical recording with neurostimulation may be a useful first step toward the development of a closed-loop DBS system for human application. PMID:24116724

Chang, Su-Youne; Kimble, Christopher J.; Kim, Inyong; Paek, Seungleal B.; Kressin, Kenneth R.; Boesche, Joshua B.; Whitlock, Sidney V.; Eaker, Diane R.; Kasasbeh, Aimen; Horne, April E.; Blaha, Charles D.; Bennet, Kevin E.; Lee, Kendall H.

2014-01-01

190

Influence of Propofol and Fentanyl on Deep Brain Stimulation of the Subthalamic Nucleus  

PubMed Central

We investigated the effect of propofol and fentanyl on microelectrode recording (MER) and its clinical applicability during subthalamic nucleus (STN) deep brain stimulation (DBS) surgery. We analyzed 8 patients with Parkinson's disease, underwent bilateral STN DBS with MER. Their left sides were done under awake and then their right sides were done with a continuous infusion of propofol and fentanyl under local anesthesia. The electrode position was evaluated by preoperative MRI and postoperative CT. The clinical outcomes were assessed at six months after surgery. We isolated single unit activities from the left and the right side MERs. There was no significant difference in the mean firing rate between the left side MERs (38.7±16.8 spikes/sec, n=78) and the right side MERs (35.5±17.2 spikes/sec, n=66). The bursting pattern of spikes was more frequently observed in the right STN than in the left STN. All the electrode positions were within the STNs on both sides and the off-time Unified Parkinson's Disease Rating Scale part III scores at six months after surgery decreased by 67% of the preoperative level. In this study, a continuous infusion of propofol and fentanyl did not significantly interfere with the MER signals from the STN. The results of this study suggest that propofol and fentanyl can be used for STN DBS in patients with advanced Parkinson's disease improving the overall experience of the patients. Graphical Abstract PMID:25246748

2014-01-01

191

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. PMID:22276074

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

2012-01-01

192

Deep Brain Stimulation for Epilepsy  

PubMed Central

Summary Many patients suffer from medically refractory epilepsy and are not candidates for resective brain surgery. Success of deep brain stimulation (DBS) in relieving a significant amount of symptoms of various movement disorders paved the way for investigations into this modality for epilepsy. Open-label and small blinded-trials have provided promising evidence for the use of DBS in refractory seizures. However, the first randomized control trial of DBS of the anterior thalamic nucleus is currently underway. Furthermore, there are multiple potential targets as many neural regions have been implicated in seizure propagation. Thus, it is difficult at this time to make any definitive judgments about the efficacy of DBS for seizure control. Future study is necessary to identify a patient population for whom this technique would be indicated, the most efficacious target, and optimal stimulation parameters. PMID:18164484

Halpern, Casey H.; Samadani, Uzma; Litt, Brian; Jaggi, Jurg L.; Baltuch, Gordon H.

2010-01-01

193

Auditory-nerve single-neuron thresholds to electrical stimulation from scala tympani electrodes.  

PubMed

Single auditory-nerve neuron thresholds were studied in sensory-deafened squirrel monkeys to determine the effects of electrical stimulus shape and frequency on single-neuron thresholds. Frequency was separated into its components, pulse width and pulse rate, which were analyzed separately. Square and sinusoidal pulse shapes were compared. There were no or questionably significant threshold differences in charge per phase between sinusoidal and square pulses of the same pulse width. There was a small (less than 0.5 dB) but significant threshold advantage for 200 microseconds/phase pulses delivered at low pulse rates (156 pps) compared to higher pulse rates (625 pps and 2500 pps). Pulse width was demonstrated to be the prime determinant of single-neuron threshold, resulting in strength-duration curves similar to other mammalian myelinated neurons, but with longer chronaxies. The most efficient electrical stimulus pulse width to use for cochlear implant stimulation was determined to be 100 microseconds/phase. This pulse width delivers the lowest charge/phase at threshold. The single-neuron strength-duration curves were compared to strength-duration curves of a computer model based on the specific anatomy of auditory-nerve neurons. The membrane capacitance and resulting chronaxie of the model can be varied by altering the length of the unmyelinated termination of the neuron, representing the unmyelinated portion of the neuron between the habenula perforata and the hair cell. This unmyelinated segment of the auditory-nerve neuron may be subject to aminoglycoside damage. Simulating a 10 micron unmyelinated termination for this model neuron produces a strength-duration curve that closely fits the single-neuron data obtained from aminoglycoside deafened animals. Both the model and the single-neuron strength-duration curves differ significantly from behavioral threshold data obtained from monkeys and humans with cochlear implants. This discrepancy can best be explained by the involvement of higher level neurologic processes in the behavioral responses. These findings suggest that the basic principles of neural membrane function must be considered in developing or analyzing electrical stimulation strategies for cochlear prostheses if the appropriate stimulation of frequency specific populations of auditory-nerve neurons is the objective. PMID:3436853

Parkins, C W; Colombo, J

1987-12-31

194

Globus Pallidus Deep Brain Stimulation for Parkinson's Disease  

Microsoft Academic Search

\\u000a Deep brain stimulation (DBS) has become the treatment of choice for patients with Parkinson' disease (PD) who are experiencing\\u000a unmanageable complications of long-term medical therapy. The two established sites for DBS for PD are the subthalamic nucleus\\u000a (STN) and the globus pallidus interna (GPi). Although most providers have already decided that STN is the preferred site for\\u000a DBS, only one

Frances Weaver; Kenneth Follett; Matthew Stern

195

Performance of DBS-Radio using concatenated coding and equalization  

NASA Technical Reports Server (NTRS)

The Direct Broadcast Satellite-Radio (DBS-R) receiver is being developed for operation in a multipath Rayleigh channel. This receiver uses equalization and concatenated coding, in addition to open loop and closed loop architectures for carrier demodulation and symbol synchronization. Performance test results of this receiver are presented in both AWGN and multipath Rayleigh channels. Simulation results show that the performance of the receiver operating in a multipath Rayleigh channel is significantly improved by using equalization. These results show that fractional-symbol equalization offers a performance advantage over full symbol equalization. Also presented is the base-line performance of the DBS-R receiver using concatenated coding and interleaving.

Gevargiz, J.; Bell, D.; Truong, L.; Vaisnys, A.; Suwitra, K.; Henson, P.

1995-01-01

196

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. PMID:21099404

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

2011-01-01

197

Acute and Chronic Mood and Apathy Outcomes from a Randomized Study of Unilateral STN and GPi DBS  

PubMed Central

Objective To study mood and behavioral effects of unilateral and staged bilateral subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) for Parkinson's disease (PD). Background There are numerous reports of mood changes following DBS, however, most have focused on bilateral simultaneous STN implants with rapid and aggressive post-operative medication reduction. Methods A standardized evaluation was applied to a subset of patients undergoing STN and GPi DBS and who were also enrolled in the NIH COMPARE study. The Unified Parkinson Disease Rating Scale (UPDRS III), the Hamilton depression (HAM-D) and anxiety rating scales (HAM-A), the Yale-Brown obsessive-compulsive rating scale (YBOCS), the Apathy Scale (AS), and the Young mania rating scale (YMRS) were used. The scales were repeated at acute and chronic intervals. A post-operative strategy of non-aggressive medication reduction was employed. Results Thirty patients were randomized and underwent unilateral DBS (16 STN, 14 GPi). There were no baseline differences. The GPi group had a higher mean dopaminergic dosage at 1-year, however the between group difference in changes from baseline to 1-year was not significant. There were no differences between groups in mood and motor outcomes. When combining STN and GPi groups, the HAM-A scores worsened at 2-months, 4-months, 6-months and 1-year when compared with baseline; the HAM-D and YMRS scores worsened at 4-months, 6-months and 1-year; and the UPDRS Motor scores improved at 4-months and 1-year. Psychiatric diagnoses (DSM-IV) did not change. No between group differences were observed in the cohort of bilateral cases. Conclusions There were few changes in mood and behavior with STN or GPi DBS. The approach of staging STN or GPi DBS without aggressive medication reduction could be a viable option for managing PD surgical candidates. A study of bilateral DBS and of medication reduction will be required to better understand risks and benefits of a bilateral approach. PMID:25469706

Okun, Michael S.; Wu, Samuel S.; Fayad, Sarah; Ward, Herbert; Bowers, Dawn; Rosado, Christian; Bowen, Lauren; Jacobson, Charles; Butson, Christopher; Foote, Kelly D.

2014-01-01

198

A new feature extraction method and classification of early stage Parkinsonian rats with and without DBS treatment.  

PubMed

Parkinson Disease (PD) is one of the most common neural disorders worldwide. Different treatments such as medication and deep brain stimulation (DBS) have been proposed to minimize and control Parkinson's symptoms. DBS has been recognized as an effective approach to decrease most movement disorders of PD. In this study, a new method is proposed for feature extraction and separation of treated and untreated Parkinsonan rats. For this purpose, unilateral intrastriatal 6-hydroxydopamine (6-OHDA, 12.5 ?g/5 ?l of saline-ascorbate)-lesioned rats were treated with DBS. We performed a behavioral experiment and video tracked traveled trajectories of rats. Then, we investigated the effect of deep brain stimulation of subthalamus nucleus on their behavioral movements. Time, frequency and chaotic features of traveled trajectories were extracted. These features provide the ability to quantify the behavioral movements of Parkinsonian rats. The results showed that the traveled trajectories of untreated were more convoluted with the different time/frequency response. Compared to the traditional features used before to quantify the animals' behavior, the new features improved classification accuracy up to 80 % for untreated and treated rats. PMID:25173488

Iravani, B; Towhidkhah, F; Roghani, M

2014-12-01

199

Authenticity or autonomy? When deep brain stimulation causes a dilemma.  

PubMed

While deep brain stimulation (DBS) for patients with Parkinson's disease has typically raised ethical questions about autonomy, accountability and personal identity, recent research indicates that we need to begin taking into account issues surrounding the patients' feelings of authenticity and alienation as well. In order to bring out the relevance of this dimension to ethical considerations of DBS, I analyse a recent case study of a Dutch patient who, as a result of DBS, faced a dilemma between autonomy and authenticity. This case study is meant to point out the normatively meaningful tension patients under DBS experience between authenticity and autonomy. PMID:23355227

Kraemer, Felicitas

2013-12-01

200

The Treatment of Movement Disorders by Deep Brain Stimulation  

E-print Network

targets for DBS treatment include the subthalamic nucleus for the treatment of advanced Parkinson DBS received U.S. Food and Drug Administration (FDA) approval for the treatment of Parkinson's diseaseThe Treatment of Movement Disorders by Deep Brain Stimulation Hong Yu and Joseph S. Neimat

Sergio, Lauren E.

201

Learning about language and speech from Deep Brain Stimulation  

Microsoft Academic Search

Neuroscientific concepts of language mostly focus on distributed networks, comprising various cortical areas that operate distinct linguistic processes. The role of subcortical structures in these networks is largely hypothetical, whereas their relevance in motor processing is certain. In this context, considerable evidence could be obtained from Deep Brain Stimulation (DBS), a therapy for different movement disorders. In DBS, the functional

Fabian Klostermann; Lea Krugel; Michael Wahl

202

DBS: a powerful tool for TCP performance evaluations  

NASA Astrophysics Data System (ADS)

Network performance measurement tools, mainly used for TCP performance evaluations, have serious problems that their applications are limited to single point-to-point configuration and only the mean throughput for long term are measurable. Their major drawback is that they cover only a subset of the entire TCP functions and small variations of network systems. In this paper, we proposed a TCP performance measurement tool called DBS (Distributed Benchmark System) which is aiming to give performance index with multi-point configuration and also in order to measure changes of throughput. It measures the performance of entire TCP functions in various operational environments. Experiments had been conducted using DBS to measure TCP end- to-end performance with various kinds of networks such as both LANs including FDDI, ATM, and HIPPI over ATM networks, and WANs including VSAT satellite channels. In short, DBS has the capability of both measuring and analyzing TCP performance more in details. Through these measurements, DBS unveiled details of TCP performance which cannot be realized by other existing tools.

Murayama, Yukio; Yamaguchi, Suguru

1997-10-01

203

Did My Brain Implant Make Me Do It? Questions Raised by DBS Regarding Psychological Continuity, Responsibility for Action and Mental Competence.  

PubMed

Deep brain stimulation (DBS) is a well-accepted treatment for movement disorders and is currently explored as a treatment option for various neurological and psychiatric disorders. Several case studies suggest that DBS may, in some patients, influence mental states critical to personality to such an extent that it affects an individual's personal identity, i.e. the experience of psychological continuity, of persisting through time as the same person. Without questioning the usefulness of DBS as a treatment option for various serious and treatment refractory conditions, the potential of disruptions of psychological continuity raises a number of ethical and legal questions. An important question is that of legal responsibility if DBS induced changes in a patient's personality result in damage caused by undesirable or even deviant behavior. Disruptions in psychological continuity can in some cases also have an effect on an individual's mental competence. This capacity is necessary in order to obtain informed consent to start, continue or stop treatment, and it is therefore not only important from an ethical point of view but also has legal consequences. Taking the existing literature and the Dutch legal system as a starting point, the present paper discusses the implications of DBS induced disruptions in psychological continuity for a patient's responsibility for action and competence of decision and raises a number of questions that need further research. PMID:24273622

Klaming, Laura; Haselager, Pim

2013-01-01

204

Confined Stimulation Using Dual Thalamic Deep Brain Stimulation Leads Rescues Refractory Essential Tremor: Report of Three Cases  

Microsoft Academic Search

Background\\/Aims: Deep brain stimulation (DBS) of the nucleus ventralis intermedius (VIM) provides a safe and effective therapy for medically refractory essential tremor (ET). However, as many as 9% of VIM DBS patients deteriorate after several years of good tremor control. For these patients, the high voltage needed to adequately control tremor also generates circumferential current spread causing intolerable adverse effects.

Hong Yu; Peter Hedera; John Fang; Thomas L. Davis; Peter E. Konrad

2009-01-01

205

Research report High-frequency stimulation of the subthalamic nucleus reverses limb-use  

E-print Network

Available online 6 May 2004 Abstract Deep brain stimulation (DBS) is a widely used clinical treatment for Parkinson's disease (PD). A rodent model of DBS is a necessary tool for understanding the neural mechanisms integration Topic: Basal ganglia Keywords: Parkinson's disease; Deep brain stimulation; Basal ganglia

Schallert, Tim

206

Long-term results of a multicenter study on subthalamic and pallidal stimulation in Parkinson's disease  

Microsoft Academic Search

We report the 5 to 6 year follow-up of a multicenter study of bilateral subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) in advanced Parkinson's disease (PD) patients. Thirty-five STN patients and 16 GPi patients were assessed at 5 to 6 years after DBS surgery. Primary outcome measure was the stimulation effect on the motor Unified

Elena Moro; Andres M. Lozano; Pierre Pollak; Yves Agid; Stig Rehncrona; Jens Volkmann; Jaime Kulisevsky; Jose A. Obeso; Alberto Albanese; Marwan I. Hariz; Niall P. Quinn; Jans D. Speelman; Alim L. Benabid; Valerie Fraix; Alexandre Mendes; Marie-Laure Welter; Jean-Luc Houeto; Philippe Cornu; Didier Dormont; Annalena L. Tornqvist; Ron Ekberg; Alfons Schnitzler; Lars Timmermann; Lars Wojtecki; Andres Gironell; Maria C. Rodriguez-Oroz; Jorge Guridi; Anna R. Bentivoglio; Maria F. Contarino; Luigi Romito; Massimo Scerrati; Marc Janssens; Anthony E. Lang

2010-01-01

207

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. PMID:24932426

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

2014-01-01

208

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

PubMed

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

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

2015-02-01

209

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

210

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

211

Subthalamic nucleus deep brain stimulation changes speech respiratory and laryngeal control in Parkinson's disease  

PubMed Central

Adequate respiratory and laryngeal motor control are essential for speech, but may be impaired in Parkinson's disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on respiratory and laryngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of respiratory and laryngeal control, and whether these changes were correlated with limb function and stimulation parameters. Eighteen PD participants with bilateral STN DBS were tested within a morning session after a minimum of 12 h since their most recent dose of anti-PD medication. Testing occurred when DBS was on, and again 1 h after DBS was turned off, and included aerodynamic measures during syllable production, and standard clinical ratings of limb function. We found that PD participants exhibited changes with DBS, consistent with increased respiratory driving pressure (n = 9) and increased vocal fold closure (n = 9). However, most participants exceeded a typical operating range for these respiratory and laryngeal control variables with DBS. Changes were uncorrelated with limb function, but showed some correlation with stimulation frequency and pulse width, suggesting that speech may benefit more from low-frequency stimulation and shorter pulse width. Therefore, high-frequency STN DBS may be less beneficial for speech-related respiratory and laryngeal control than for limb motor control. It is important to consider these distinctions and their underlying mechanisms when assessing the impact of STN DBS on PD. PMID:20582431

Barlow, Steven M.; Lyons, Kelly E.; Pahwa, Rajesh

2010-01-01

212

Subthalamic nucleus deep brain stimulation changes velopharyngeal control in Parkinson’s disease  

PubMed Central

Purpose Adequate velopharyngeal control is essential for speech, but may be impaired in Parkinson’s disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on velopharyngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of velopharyngeal control, and whether these changes were correlated with limb function and stimulation settings. Methods Seventeen PD participants with bilateral STN DBS were tested within a morning session after a minimum of 12 h since their most recent dose of anti-PD medication. Testing occurred when STN DBS was on, and again 1 h after STN DBS was turned off, and included aerodynamic measures during syllable production, and standard neurological ratings of limb function. Results We found that PD participants exhibited changes with STN DBS, primarily consistent with increased intraoral pressure (n = 7) and increased velopharyngeal closure (n = 5). These changes were modestly correlated with measures of limb function, and were correlated with stimulation frequency. Conclusion Our findings suggest that STN DBS may change velopharyngeal control during syllable production in PD, with greater benefit associated with low frequency stimulation. However, DBS demonstrates a more subtle influence on speech-related velopharyngeal control than limb motor control. This distinction and its underlying mechanisms are important to consider when assessing the impact of STN DBS on PD. PMID:20708741

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

2010-01-01

213

Deep brain stimulation for advanced Parkinson's disease.  

PubMed

Deep brain stimulation (DBS) is a new and promising technique for the treatment of movement disorders. Medically intractable Parkinson's disease (PD) is one of the most common indications for DBS. There are three possible subcortical targets for PD, depending on the symptomatology (i.e., the motor subdivision of the thalamus, the globus pallidus internus, the subthalamic nucleus [STN]). Thalamic stimulation has been well established as a safe and effective treatment for essential tremor and the tremor associated with PD. Globus pallidus internus and STN DBS are being investigated for the treatment of all the cardinal signs of PD. This article describes the pathophysiology of PD, the surgical treatment history of PD, surgical techniques used for DBS implants, and the role the perioperative nurse has in the care of the patients undergoing these procedures. PMID:11004960

Byrd, D L; Marks, W J; Starr, P A

2000-09-01

214

Controlling stimulation strength and focality in electroconvulsive therapy via current amplitude and electrode size and spacing: comparison with magnetic seizure therapy  

PubMed Central

Objectives Understanding the relationship between the stimulus parameters of electroconvulsive therapy (ECT) and the electric field characteristics could guide studies on improving risk/benefit ratio. We aim to determine the effect of current amplitude and electrode size and spacing on the ECT electric field characteristics, compare ECT focality with magnetic seizure therapy (MST), and evaluate stimulus individualization by current amplitude adjustment. Methods ECT and double-cone-coil MST electric field was simulated in a 5-shell spherical human head model. A range of ECT electrode diameters (2–5 cm), spacing (1–25 cm), and current amplitudes (0–900 mA) were explored. The head model parameters were varied to examine the stimulus current adjustment required to compensate for interindividual anatomical differences. Results By reducing the electrode size, spacing, and current, the ECT electric field can be more focal and superficial without increasing scalp current density. By appropriately adjusting the electrode configuration and current, the ECT electric field characteristics can be made to approximate those of MST within 15%. Most electric field characteristics in ECT are more sensitive to head anatomy variation than in MST, especially for close electrode spacing. Nevertheless, ECT current amplitude adjustment of less than 70% can compensate for interindividual anatomical variability. Conclusions The strength and focality of ECT can be varied over a wide range by adjusting the electrode size, spacing, and current. If desirable, ECT can be made as focal as MST while using simpler stimulation equipment. Current amplitude individualization can compensate for interindividual anatomical variability. PMID:24263276

Deng, Zhi-De; Lisanby, Sarah H.; Peterchev, Angel V.

2013-01-01

215

Role of adenosine in the antiepileptic effects of deep brain stimulation  

PubMed Central

Despite the effectiveness of anterior thalamic nucleus (AN) deep brain stimulation (DBS) for the treatment of epilepsy, mechanisms responsible for the antiepileptic effects of this therapy remain elusive. As adenosine modulates neuronal excitability and seizure activity in animal models, we hypothesized that this nucleoside could be one of the substrates involved in the effects of AN DBS. We applied 5 days of stimulation to rats rendered chronically epileptic by pilocarpine injections and recorded epileptiform activity in hippocampal slices. We found that slices from animals given DBS had reduced hippocampal excitability and were less susceptible to develop ictal activity. In live animals, AN DBS significantly increased adenosine levels in the hippocampus as measured by microdialysis. The reduced excitability of DBS in vitro was completely abolished in animals pre-treated with A1 receptor antagonists and was strongly potentiated by A1 receptor agonists. We conclude that some of the antiepileptic effects of DBS may be mediated by adenosine. PMID:25324724

Miranda, Maisa F.; Hamani, Clement; de Almeida, Antônio-Carlos G.; Amorim, Beatriz O.; Macedo, Carlos E.; Fernandes, Maria José S.; Nobrega, José N.; Aarão, Mayra C.; Madureira, Ana Paula; Rodrigues, Antônio M.; Andersen, Monica L.; Tufik, Sergio; Mello, Luiz E.; Covolan, Luciene

2014-01-01

216

[Distribution of current density over the surface of electrodes of an autonomic stimulator of the gastrointestinal tract].  

PubMed

The paper outlines a distributed self-contained gastrointestinal electrostimulator model that considers current distribution in the electrolytic environment and electrochemical polarization inhomogeneity over the surface of cap electrodes. The model is satisfactory in describing the experimental data obtained for electrodes made of the stainless steel 12X18H9 in 1% hydrochloric acid solution (that mimics gastric acid) and may be useful in evaluating the performance of and in optimizing the self-contained electrostimulator with the electrodes covered by different materials. PMID:8992182

Agafonnikov, V F; Nalesnik, O I; Romanovski?, M N

1996-01-01

217

Movement Disorders: Deep-Brain Stimulation Perspective  

Microsoft Academic Search

\\u000a The introduction and technical refinements of deep-brain stimulation (DBS) for the treatment of movement disorders over the\\u000a past 15 years have resulted in a renaissance in the field of functional neurosurgery. For patients with medically refractory\\u000a movement disorders, DBS procedures have largely replaced neuroablative techniques in the treatment of patients with movement\\u000a disorders. This shift away from ablative procedures is

John Y. K. Lee; Joshua M. Rosenow; Ali R. Rezai

218

Improved transcranial magnetic stimulation coil design with realistic head modeling  

NASA Astrophysics Data System (ADS)

We are investigating Transcranial magnetic stimulation (TMS) as a noninvasive technique based on electromagnetic induction which causes stimulation of the neurons in the brain. TMS can be used as a pain-free alternative to conventional electroconvulsive therapy (ECT) which is still widely implemented for treatment of major depression. Development of improved TMS coils capable of stimulating subcortical regions could also allow TMS to replace invasive deep brain stimulation (DBS) which requires surgical implantation of electrodes in the brain. Our new designs allow new applications of the technique to be established for a variety of diagnostic and therapeutic applications of psychiatric disorders and neurological diseases. Calculation of the fields generated inside the head is vital for the use of this method for treatment. In prior work we have implemented a realistic head model, incorporating inhomogeneous tissue structures and electrical conductivities, allowing the site of neuronal activation to be accurately calculated. We will show how we utilize this model in the development of novel TMS coil designs to improve the depth of penetration and localization of stimulation produced by stimulator coils.

Crowther, Lawrence; Hadimani, Ravi; Jiles, David

2013-03-01

219

Optimizing deep brain stimulation settings using wearable sensing technology  

E-print Network

Parkinson's disease is a neurodegenerative movement disorder resulting in rigidity, bradykinesia (slowness), tremor and gait disorder. Deep brain stimulation (DBS) of the subthalamic nucleus has been shown to be effective ...

Patel, Shyamal

220

Ethical Issues Raised by Proposals to Treat Addiction Using Deep Brain Stimulation  

Microsoft Academic Search

Deep brain stimulation (DBS) has been proposed as a potential treatment of drug addiction on the basis of its effects on drug\\u000a self-administration in animals and on addictive behaviours in some humans treated with DBS for other psychiatric or neurological\\u000a conditions. DBS is seen as a more reversible intervention than ablative neurosurgery but it is nonetheless a treatment that\\u000a carries

Adrian Carter; Emily Bell; Eric Racine; Wayne Hall

2011-01-01

221

Controlled On-chip Stimulation of Quantal Catecholamine Release from Chromaffin Cells Using Photolysis of Caged Ca2+ on Transparent Indium-Tin-Oxide Microchip Electrodes  

PubMed Central

Photorelease of caged Ca2+ is a uniquely powerful tool to study the dynamics of Ca2+-triggered exocytosis from individual cells. Using photolithography and other microfabrication techniques, we have developed transparent microchip devices to enable photorelease of caged Ca2+ together with electrochemical detection of quantal catecholamine secretion from individual cells or cell arrays as a step towards developing high-throughput experimental devices. A 100 nm - thick transparent Indium-Tin-Oxide (ITO) film was sputter-deposited onto glass coverslips, which were then patterned into 24 cell-sized working electrodes (?20 ?m by 20 ?m). We loaded bovine chromaffin cells with acetoxymethyl (AM) ester derivatives of the Ca2+ cage NP-EGTA and Ca2+ indicator dye Fura-4F, then transferred these cells onto the working ITO electrodes for amperometric recordings. Upon flash photorelease of caged Ca2+, a uniform rise of [Ca2+]i within the target cell leads to quantal release of oxidizable catecholamines measured amperometrically by the underlying ITO electrode. We observed a burst of amperometric spikes upon rapid elevation of [Ca2+]i and a “priming” effect of sub-stimulatory [Ca2+]i on the response of cells to subsequent [Ca2+]i elevation, similar to previous reports using different techniques. We conclude that UV photolysis of caged Ca2+ is a suitable stimulation technique for higher-throughput studies of Ca2+-dependent exocytosis on transparent electrochemical microelectrode arrays. PMID:18094774

Chen, Xiaohui; Gao, Yuanfang; Hossain, Maruf; Gangopadhyay, Shubhra; Gillis, Kevin D.

2008-01-01

222

Network Perspectives on the Mechanisms of Deep Brain Stimulation  

PubMed Central

Deep brain stimulation (DBS) is an established medical therapy for the treatment of movement disorders and shows great promise for several other neurological disorders. However, after decades of clinical utility the underlying therapeutic mechanisms remain undefined. Early attempts to explain the mechanisms of DBS focused on hypotheses that mimicked an ablative lesion to the stimulated brain region. More recent scientific efforts have explored the wide-spread changes in neural activity generated throughout the stimulated brain network. In turn, new theories on the mechanisms of DBS have taken a systems-level approach to begin to decipher the network activity. This review provides an introduction to some of the network based theories on the function and pathophysiology of the cortico-basal-ganglia-thalamo-cortical loops commonly targeted by DBS. We then analyze some recent results on the effects of DBS on these networks, with a focus on subthalamic DBS for the treatment of Parkinson's disease. Finally we attempt to summarize how DBS could be achieving its therapeutic effects by overriding pathological network activity. PMID:19804831

McIntyre, Cameron C.; Hahn, Philip J.

2009-01-01

223

Identifying candidates for deep brain stimulation in Parkinson's disease: the role of the primary care physician.  

PubMed

Deep brain stimulation (DBS) can improve symptoms in well-selected patients with Parkinson's disease. Primary care physicians must take into account many important issues when considering referral for DBS. The Florida Surgical Questionnaire for PD (FLASQ-PD), a 5-section screening tool that can help primary care providers identify appropriate DBS candidates, can be filled out and scored by a general practitioner, advanced clinical nurse practitioner, physician assistant, or trained nurse. Potential candidates who score well on this questionnaire can be referred for presurgical multidisciplinary evaluation at an experienced DBS implanting center. PMID:17489644

Okun, Michael S; Fernandez, Hubert H; Rodriguez, Ramon L; Foote, Kelly D

2007-05-01

224

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. PMID:23440258

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

2012-01-01

225

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

226

Evaluation of accuracy in frame-based versus fiducial-based registration for stereotaxy in Parkinson's deep electrode implantation  

NASA Astrophysics Data System (ADS)

After several years of levodopa treatment, patients with Parkinson's Disease (PD) can develop difficult-to-control motor fluctuations and levodopa-induced dyskinesias (LID). Surgical options for these medically intractable PD patients include deep nucleus lesioning and stimulation. Because it is adjustable and reversible, deep brain stimulations (DBS) is preferable to ablative procedures. Traditionally, frame- based stereotaxy has been used to register these patients during deep electrode implantation. This study investigated the accuracy of the less invasive frameless registration method in 9 patients and found an overall mean error of 1.9mm (range: 1.1mm min, 2.7mm max) with an overall SD of 0.7mm. This error range is not acceptable for the submillimeter precision needed in microelectrode implantation. The lab is currently investing the accuracy of the frameless bone-screw marker method that is still less invasive and cumbersome than the frame-based system.

Abbasi, Hamid R.; Hariri, Sanaz; Lee, Jeffrey; Martin, David; Hill, B.; Heit, Gary

2001-05-01

227

Optical coherence tomography and optical coherence domain reflectometry for deep brain stimulation probe guidance  

Microsoft Academic Search

Deep Brain Stimulation (DBS) is FDA-approved for the treatment of Parkinson's disease and essential tremor. Currently, placement of DBS leads is guided through a combination of anatomical targeting and intraoperative microelectrode recordings. The physiological mapping process requires several hours, and each pass of the microelectrode into the brain increases the risk of hemorrhage. Optical Coherence Domain Reflectometry (OCDR) in combination

Sung W. Jeon; Mark A. Shure; Kenneth B. Baker; Ali Chahlavi; Nagi Hatoum; Massud Turbay; Andrew M. Rollins; Ali R. Rezai; David Huang

2005-01-01

228

Deep Brain Stimulation to Reward Circuitry Alleviates Anhedonia in Refractory Major Depression  

Microsoft Academic Search

Deep brain stimulation (DBS) to different sites allows interfering with dysfunctional network function implicated in major depression. Because a prominent clinical feature of depression is anhedoniaFthe inability to experience pleasure from previously pleasurable activitiesFand because there is clear evidence of dysfunctions of the reward system in depression, DBS to the nucleus accumbens might offer a new possibility to target depressive

Thomas E Schlaepfer; Michael X Cohen; Caroline Frick; Markus Kosel; Daniela Brodesser; Nikolai Axmacher; Alexius Young Joe; Martina Kreft; Doris Lenartz; Volker Sturm

2007-01-01

229

Deep Brain Stimulation to Reward Circuitry Alleviates Anhedonia in Refractory Major Depression  

Microsoft Academic Search

Deep brain stimulation (DBS) to different sites allows interfering with dysfunctional network function implicated in major depression. Because a prominent clinical feature of depression is anhedonia—the inability to experience pleasure from previously pleasurable activities—and because there is clear evidence of dysfunctions of the reward system in depression, DBS to the nucleus accumbens might offer a new possibility to target depressive

Thomas E Schlaepfer; Michael X Cohen; Caroline Frick; Markus Kosel; Daniela Brodesser; Nikolai Axmacher; Alexius Young Joe; Martina Kreft; Doris Lenartz; Volker Sturm

2008-01-01

230

Three-Year Outcomes in Deep Brain Stimulation for Highly Resistant Obsessive–Compulsive Disorder  

Microsoft Academic Search

Deep brain stimulation (DBS) of the anterior limb of the internal capsule has been shown to be beneficial in the short term for obsessive–compulsive disorder (OCD) patients who exhaust conventional therapies. Nuttin et al, who published the first DBS for OCD series, found promising results using a capsule target immediately rostral to the anterior commissure extending into adjacent ventral capsule\\/ventral

Benjamin D Greenberg; Donald A Malone; Gerhard M Friehs; Ali R Rezai; Cynthia S Kubu; Paul F Malloy; Stephen P Salloway; Michael S Okun; Wayne K Goodman; Steven A Rasmussen

2006-01-01

231

Bilateral deep brain stimulation in Parkinson's disease: a multicentre study with 4 years follow-up  

Microsoft Academic Search

Deep brain stimulation (DBS) is associated with significant improvement of motor complications in patients with severe Parkinson's disease after some 6-12 months of treatment. Long-term results in a large number of patients have been reported only from a single study centre. We report 69 Parkinson's disease patients treated with bilateral DBS of the subthalamic nucleus (STN, n= 49) or globus

M. C. Rodriguez-Oroz; J. A. Obeso; A. E. Lang; J.-L. Houeto; P. Pollak; S. Rehncrona; J. Kulisevsky; A. Albanese; J. Volkmann; M. I. Hariz; N. P. Quinn; J. D. Speelman; J. Guridi; I. Zamarbide; A. Gironell; J. Molet; B. Pascual-Sedano; B. Pidoux; A. M. Bonnet; Y. Agid; J. Xie; A.-L. Benabid; A. M. Lozano; J. Saint-Cyr; L. Romito; M. F. Contarino; M. Scerrati; V. Fraix; N. Van Blercom

2005-01-01

232

Determining Factors for the Reduction of Dopaminergic Drugs after Bilateral Subthalamic Nucleus Deep Brain Stimulation  

Microsoft Academic Search

Background: We aimed to investigate the possible factors determining reduction of dopaminergic drugs in patients who received bilateral subthalamic nucleus (STN) deep brain stimulation (DBS). Methods: We studied 33 consecutive Parkinson's disease (PD) patients who underwent bilateral STN DBS between March 2002 and April 2006. Patients were assessed at baseline and 6 months and 1 year after surgery. Results: The

Mi Jung Kim; Mi Sun Kim; Myoung Chong Lee

233

Abnormal T2Weighted MRI Signal Surrounding Leads in a Subset of Deep Brain Stimulation Patients  

Microsoft Academic Search

Background: Deep brain stimulation (DBS) surgery is a common treatment option for numerous neurological disorders. However, it is not without potential complications, such as hemorrhage and infection. Interestingly, we have observed several instances of abnormal T2-weighted signal hyperintensity surrounding DBS leads on postoperative MRI that are not associated with hemorrhage or infection. Methods: To better characterize the incidence and timing

Dario J. Englot; Christine M. Glastonbury; Paul S. Larson

2011-01-01

234

Pre- and Post- GPi DBS Neuropsychological Profiles in a Case of X-Linked Dystonia-Parkinsonism  

PubMed Central

We present the pre to post bilateral globus pallidus interna (GPi) deep brain stimulation neuropsychological profiles of a 69-year-old patient with a 12-year history of X-linked dystonia-Parkinsonism (XDP). Pre-operative cognitive function was impaired in almost all domains and this impaired performance was not dependent on his medications. Following DBS, changes in neuropsychological functioning were examined using Reliable Change Indices and standardized z-score comparisons. Results showed reductions in processing speed in the context of stable performance in language and visuospatial domains. Postoperative improvements occurred on a cognitive screening measure, verbal memory, and a test of problem-solving skills. This is the first report on an individual with XDP who was cognitively impaired, but had good outcome following GPi bilateral stimulation to treat debilitating motor symptoms. The possible mechanisms for his stable cognitive performance include the target of his DBS, reduced medication dosage, and improvement in dystonia that may in turn have reduced patient’s pain. PMID:21253963

Kemmotsu, Nobuko; Price, Catherine C.; Oyama, Genko; Okun, Michael S.; Foote, Kelly D.; Howe, Laura L. S.; Bowers, Dawn

2011-01-01

235

Deep Brain Stimulation of Nucleus Accumbens Region in Alcoholism Affects Reward Processing  

PubMed Central

The influence of bilateral deep brain stimulation (DBS) of the nucleus nucleus (NAcc) on the processing of reward in a gambling paradigm was investigated using H2[15O]-PET (positron emission tomography) in a 38-year-old man treated for severe alcohol addiction. Behavioral data analysis revealed a less risky, more careful choice behavior under active DBS compared to DBS switched off. PET showed win- and loss-related activations in the paracingulate cortex, temporal poles, precuneus and hippocampus under active DBS, brain areas that have been implicated in action monitoring and behavioral control. Except for the temporal pole these activations were not seen when DBS was deactivated. These findings suggest that DBS of the NAcc may act partially by improving behavioral control. PMID:22629317

Heldmann, Marcus; Berding, Georg; Voges, Jürgen; Bogerts, Bernhard; Galazky, Imke; Müller, Ulf; Baillot, Gunther; Heinze, Hans-Jochen; Münte, Thomas F.

2012-01-01

236

Dynamic Stereotypic Responses of Basal Ganglia Neurons to Subthalamic Nucleus High-Frequency Stimulation in the Parkinsonian Primate  

PubMed Central

Deep brain stimulation (DBS) in the subthalamic nucleus (STN) is a well-established therapy for patients with severe Parkinson's disease (PD); however, its mechanism of action is still unclear. In this study we explored static and dynamic activation patterns in the basal ganglia (BG) during high-frequency macro-stimulation of the STN. Extracellular multi-electrode recordings were performed in primates rendered parkinsonian using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Recordings were preformed simultaneously in the STN and the globus pallidus externus and internus. Single units were recorded preceding and during the stimulation. During the stimulation, STN mean firing rate dropped significantly, while pallidal mean firing rates did not change significantly. The vast majority of neurons across all three nuclei displayed stimulation driven modulations, which were stereotypic within each nucleus but differed across nuclei. The predominant response pattern of STN neurons was somatic inhibition. However, most pallidal neurons demonstrated synaptic activation patterns. A minority of neurons across all nuclei displayed axonal activation. Temporal dynamics were observed in the response to stimulation over the first 10 seconds in the STN and over the first 30 seconds in the pallidum. In both pallidal segments, the synaptic activation response patterns underwent delay and decay of the magnitude of the peak response due to short term synaptic depression. We suggest that during STN macro-stimulation the STN goes through a functional ablation as its upper bound on information transmission drops significantly. This notion is further supported by the evident dissociation between the stimulation driven pre-synaptic STN somatic inhibition and the post-synaptic axonal activation of its downstream targets. Thus, BG output maintains its firing rate while losing the deleterious effect of the STN. This may be a part of the mechanism leading to the beneficial effect of DBS in PD. PMID:21559345

Moran, Anan; Stein, Edward; Tischler, Hadass; Belelovsky, Katya; Bar-Gad, Izhar

2011-01-01

237

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

238

Regulation of vesicle transport and cell motility by Golgi-localized Dbs.  

PubMed

DBS/MCF2L has been recently identified as a risk locus for osteoarthritis. It encodes a guanine nucleotide exchange factor (Dbs) that has been shown to regulate both normal and tumor cell motility. In the current study, we have determined that endogenous Dbs is predominantly expressed as 2 isoforms, a 130 kDa form (Dbs-130) that is localized to the Golgi complex, and an 80 kDa form (Dbs-80) that is localized to the endoplasmic reticulum (ER). We have previously described an inhibitor that binds to the RhoGEF domain of Dbs and blocks its transforming activity. Here we show that the inhibitor localizes to the Golgi, where it specifically interacts with Dbs-130. Inhibition of endogenous Dbs-130 activity is associated with reduced levels of activated Cdc42, enlarged Golgi, and resistance to Brefeldin A-mediated Golgi dispersal, suggesting a role for Dbs in vesicle transport. Cells treated with the inhibitor exhibit normal protein transport from the ER to the Golgi, but are defective in transport from the Golgi to the plasma membrane. Inhibition of Dbs-130 in MDA-MB-231 human breast tumor cells limits motility in both transwell and wound healing assays, but appears to have no effect on the organization of the microtubule cytoskeleton. The reduced motility is associated with a failure to reorient the Golgi toward the leading edge. This is consistent with the Golgi localization, and suggests that the Dbs-130 regulates aspects of the secretory pathway that are required to support cell polarization during directed migration. PMID:25483302

Fitzpatrick, Ethan R; Hu, Tinghui; Ciccarelli, Bryan T; Whitehead, Ian P

2014-10-01

239

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

240

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

241

No Impact of Deep Brain Stimulation on Fear-Potentiated Startle in Obsessive–Compulsive Disorder  

PubMed Central

Deep brain stimulation (DBS) of the ventral internal capsule is effective in treating therapy refractory obsessive–compulsive disorder (OCD). Given the close proximity of the stimulation site to the stria terminalis (BNST), we hypothesized that the striking decrease in anxiety symptoms following DBS could be the result of the modulation of contextual anxiety. However, the effect of DBS in this region on contextual anxiety is as of yet unknown. Thus, the current study investigated the effect of DBS on contextual anxiety in an experimental threat of shock paradigm. Eight patients with DBS treatment for severe OCD were tested in a double-blind crossover design with randomly assigned 2-week periods of active and sham stimulation. DBS resulted in significant decrease of obsessive–compulsive symptoms, anxiety, and depression. However, even though the threat manipulation resulted in a clear context-potentiated startle effect, none of the parameters derived from the startle recordings was modulated by the DBS. This suggests that DBS in the ventral internal capsule is effective in treating anxiety symptoms of OCD without modulating the startle circuitry. We hypothesize that the anxiety symptoms present in OCD are likely distinct from the pathological brain circuits in defensive states of other anxiety disorders. PMID:25249953

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

2014-01-01

242

Bimanual Force Coordination in Parkinson’s Disease Patients with Bilateral Subthalamic Deep Brain Stimulation  

PubMed Central

Objective Studies of bimanual actions similar to activities of daily living (ADLs) are currently lacking in evaluating fine motor control in Parkinson’s disease patients implanted with bilateral subthalamic deep brain stimulators. We investigated basic time and force characteristics of a bimanual task that resembles performance of ADLs in a group of bilateral subthalamic deep brain stimulation (DBS) patients. Methods Patients were evaluated in three different DBS parameter conditions off stimulation, on clinically derived stimulation parameters, and on settings derived from a patient-specific computational model. Model-based parameters were computed as a means to minimize spread of current to non-motor regions of the subthalamic nucleus via Cicerone Deep Brain Stimulation software. Patients were evaluated off parkinsonian medications in each stimulation condition. Results The data indicate that DBS parameter state does not affect most aspects of fine motor control in ADL-like tasks; however, features such as increased grip force and grip symmetry varied with the stimulation state. In the absence of DBS parameters, patients exhibited significant grip force asymmetry. Overall UPDRS-III and UPDRS-III scores associated with hand function were lower while patients were experiencing clinically-derived or model-based parameters, as compared to the off-stimulation condition. Conclusion While bilateral subthalamic DBS has been shown to alleviate gross motor dysfunction, our results indicate that DBS may not provide the same magnitude of benefit to fine motor coordination. PMID:24244388

Gorniak, Stacey L.; McIntyre, Cameron C.; Alberts, Jay L.

2013-01-01

243

Alterations in blood glucose and plasma glucagon concentrations during deep brain stimulation in the shell region of the nucleus accumbens in rats  

PubMed Central

Deep brain stimulation (DBS) of the nucleus accumbens (NAc) is an effective therapy for obsessive compulsive disorder (OCD) and is currently under investigation as a treatment for eating disorders. DBS of this area is associated with altered food intake and pharmacological treatment of OCD is associated with the risk of developing type 2 diabetes. Therefore we examined if DBS of the NAc-shell (sNAc) influences glucose metabolism. Male Wistar rats were subjected to DBS, or sham stimulation, for a period of 1 h. To assess the effects of stimulation on blood glucose and glucoregulatory hormones, blood samples were drawn before, during and after stimulation. Subsequently, all animals were used for quantitative assessment of Fos immunoreactivity in the lateral hypothalamic area (LHA) using computerized image analysis. DBS of the sNAc rapidly increased plasma concentrations of glucagon and glucose while sham stimulation and DBS outside the sNAc were ineffective. In addition, the increase in glucose was dependent on DBS intensity. In contrast, the DBS-induced increase in plasma corticosterone concentrations was independent of intensity and region, indicating that the observed DBS-induced metabolic changes were not due to corticosterone release. Stimulation of the sNAc with 200 ?A increased Fos immunoreactivity in the LHA compared to sham or 100 ?A stimulated animals. These data show that DBS of the sNAc alters glucose metabolism in a region- and intensity- dependent manner in association with neuronal activation in the LHA. Moreover, these data illustrate the need to monitor changes in glucose metabolism during DBS-treatment of OCD patients. PMID:24339800

Diepenbroek, Charlene; van der Plasse, Geoffrey; Eggels, Leslie; Rijnsburger, Merel; Feenstra, Matthijs G. P.; Kalsbeek, Andries; Denys, Damiaan; Fliers, Eric; Serlie, Mireille J.; la Fleur, Susanne E.

2013-01-01

244

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

245

Perceived articulatory precision in patients with Parkinson's disease after deep brain stimulation of subthalamic nucleus and caudal zona incerta.  

PubMed

Abstract The effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and caudal zona incerta (cZi) on speech articulation in patients with Parkinson's disease (PD) was investigated. Read speech samples were collected from nine patients with STN-DBS and 10 with cZi-DBS. The recordings were made pre-operatively and 12 months post-operatively with stimulator on and off (on medication). Blinded, randomised, repeated perceptual assessments were performed on words and isolated fricatives extracted from the recordings to assess (1) overall articulatory quality ratings, (2) frequency of occurrence of misarticulation patterns and (3) fricative production. Statistically significant worsening of articulatory measures on- compared with off-stimulation occurred in the cZi-DBS group, with deteriorated articulatory precision ratings, increased presence of misarticulations (predominately altered realisations of plosives and fricatives) and a reduced accuracy in fricative production. A similar, but not significant, trend was found for the STN-DBS group. PMID:25333411

Eklund, Elisabeth; Qvist, Johanna; Sandström, Lena; Viklund, Fanny; Van Doorn, Jan; Karlsson, Fredrik

2015-02-01

246

47 CFR 73.756 - System specifications for double-sideband (DBS) modulated emissions in the HF broadcasting service.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false System specifications for double-sideband (DBS) modulated emissions in the HF broadcasting service. 73... § 73.756 System specifications for double-sideband (DBS) modulated emissions in the HF broadcasting service....

2010-10-01

247

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

248

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

249

Characterisation of cortical activity in response to deep brain stimulation of ventral–lateral nucleus: Modelling and experiment  

Microsoft Academic Search

Motivated by its success as a therapeutic treatment in other neurological disorders, most notably Parkinson’s disease, Deep Brain Stimulation (DBS) is currently being trialled in a number of patients with drug unresponsive epilepsies. However, the mechanisms by which DBS interferes with neuronal activity linked to the disorder are not well understood. Furthermore, there is a need to identify optimized values

Mohit H. Adhikari; Joost H. Heeroma; Mario di Bernardo; Bernd Krauskopf; Mark P. Richardson; Matthew C. Walker; John R. Terry

2009-01-01

250

Long-term follow-up of pallidal deep brain stimulation in two cases of Huntington's disease  

Microsoft Academic Search

BackgroundDeep brain stimulator (DBS) implantation has been shown to be effective in the treatment of various movement disorders including Parkinson's disease, essential tremor and dystonia. However, there is limited information regarding the potential use of DBS in Huntington's disease (HD). In this study, the authors present their findings on the long-term motor and neurocognitive results of two HD patients (patient

Gail A Kang; Susan Heath; Johannes Rothlind; Philip A Starr

2010-01-01

251

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. PMID:22893803

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

2011-01-01

252

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

253

Deep Brain Stimulation and the Role of the Neuropsychologist  

Microsoft Academic Search

Deep brain stimulation (DBS) now plays an important role in the treatment of Parkinson's disease, tremor, and dystonia. DBS may also have a role in the treatment of other disorders such as obsessive-compulsive disorder, Tourette's syndrome, and depression. The neuropsychologist plays a crucial role in patient selection, follow-up, and management of intra-operative and post-operative effects (Pillon, 2002; Saint-Cyr & Trepanier,

Michael S. Okun; Ramon L. Rodriguez; Ania Mikos; Kimberly Miller; Ida Kellison; Lindsey Kirsch-Darrow; Dylan P. Wint; Utaka Springer; Hubert H. Fernandez; Kelly D. Foote; Gregory Crucian; Dawn Bowers

2007-01-01

254

Current Progress on Pathological Tremor Modeling and Active Compensation using Functional Electrical Stimulation  

E-print Network

effects may still occur, like brain hemorrhage, seizures, marked cognitive problems and death. The recent is severe, brain stereotactic surgery, such as Deep Brain Stimulation (DBS), although risky and expensive

Paris-Sud XI, Université de

255

Moving Forward: Advances in the Treatment of Movement Disorders with Deep Brain Stimulation  

PubMed Central

The modern era of stereotactic and functional neurosurgery has ushered in state of the art technologies for the treatment of movement disorders, particularly Parkinson’s disease (PD), tremor, and dystonia. After years of experience with various surgical therapies, the eventual shortcomings of both medical and surgical treatments, and several serendipitous discoveries, deep brain stimulation (DBS) has risen to the forefront as a highly effective, safe, and reversible treatment for these conditions. Idiopathic advanced PD can be treated with thalamic, globus pallidus internus (GPi), or subthalamic nucleus (STN) DBS. Thalamic DBS primarily relieves tremor while GPi and STN DBS alleviate a wide range of Parkinsonian symptoms. Thalamic DBS is also used in the treatment of other types of tremor, particularly essential tremor, with excellent results. Both primary and various types of secondary dystonia can be treated very effectively with GPi DBS. The variety of anatomical targets for these movement disorders is indicative of the network-level dysfunction mediating these movement disturbances. Despite an increasing understanding of the clinical benefits of DBS, little is known about how DBS can create such wide sweeping neuromodulatory effects. The key to improving this therapeutic modality and discovering new ways to treat these and other neurologic conditions lies in better understanding the intricacies of DBS. Here we review the history and pertinent clinical data for DBS treatment of PD, tremor, and dystonia. While multiple regions of the brain have been targeted for DBS in the treatment of these movement disorders, this review article focuses on those that are most commonly used in current clinical practice. Our search criteria for PubMed included combinations of the following terms: DBS, neuromodulation, movement disorders, PD, tremor, dystonia, and history. Dates were not restricted. PMID:22084629

Schiefer, Terry K.; Matsumoto, Joseph Y.; Lee, Kendall H.

2011-01-01

256

Successful subthalamic nucleus deep brain stimulation therapy after significant lead displacement from a subdural hematoma.  

PubMed

A 57-year-old man with a 21year history of Parkinson's disease underwent bilateral subthalamic nucleus deep brain stimulation (DBS) placement. One week postoperatively he developed an acute left subdural hematoma from a fall with significant displacement of the DBS leads. It was promptly evacuated, the patient slowly recovered neurologically, and the leads again moved near to the original position. Six months of stimulation therapy attained 50% reduction in symptoms. This case report demonstrates the movement of DBS leads due to brain shift and their ability to come back to previous location once the brain shift is corrected. PMID:25304438

Henderson, Esmiralda Yeremeyeva; Goble, Timothy; D'Haese, Pierre-François; Pallavaram, Srivatsan; Oluigbo, Chima; Agrawal, Punit; Deogaonkar, Milind; Rezai, Ali

2015-02-01

257

Long-term follow-up of deep brain stimulation of peduncolopontine nucleus in progressive supranuclear palsy: Report of three cases  

PubMed Central

Background: Progressive supranuclear palsy (PSP) is a neurodegenerative disease due to mitochondrial dysfunction. The PSP syndrome presents generally with gait disorder, Parkinsonism, ophthalmoparesis and cognitive alteration. Few reports exist on deep brain stimulation (DBS) in patients with atypical Parkinsonism. The aim of our study was to evaluate further the potential role of DBS in PSP. Case Description: We report three patients with PSP with long-term follow up undergoing DBS. Two patients had right peripedunculopontine nucleus (PPN) stimulation and one patient had simultaneous right PPN and bilateral globus pallidus internus DBS. DBS of the PPN alone or combined with globus pallidus internus (GPi) determined an improvement in gait and a reduction in falls sustained over time. Combined target stimulation (GPi-PPN) was correlated with better clinical outcome than single target (PPN) DBS for PSP. Conclusions: Although few data on DBS for PSP exist, reported clinical results are encouraging. DBS might be considered as an alternative therapeutic option for patients with PSP presenting with relevant gait imbalance and frequent falls, who fail to respond to pharmacological treatment. Larger cohorts with longer follow-ups are needed to evaluate more exhaustively the efficacy of DBS in PSP. PMID:25289173

Servello, Domenico; Zekaj, Edvin; Saleh, Christian; Menghetti, Claudia; Porta, Mauro

2014-01-01

258

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

259

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

260

Direct Exploration of the Role of the Ventral Anterior Temporal Lobe in Semantic Memory: Cortical Stimulation and Local Field Potential Evidence From Subdural Grid Electrodes.  

PubMed

Semantic memory is a crucial higher cortical function that codes the meaning of objects and words, and when impaired after neurological damage, patients are left with significant disability. Investigations of semantic dementia have implicated the anterior temporal lobe (ATL) region, in general, as crucial for multimodal semantic memory. The potentially crucial role of the ventral ATL subregion has been emphasized by recent functional neuroimaging studies, but the necessity of this precise area has not been selectively tested. The implantation of subdural electrode grids over this subregion, for the presurgical assessment of patients with partial epilepsy or brain tumor, offers the dual yet rare opportunities to record cortical local field potentials while participants complete semantic tasks and to stimulate the functionally identified regions in the same participants to evaluate the necessity of these areas in semantic processing. Across 6 patients, and utilizing a variety of semantic assessments, we evaluated and confirmed that the anterior fusiform/inferior temporal gyrus is crucial in multimodal, receptive, and expressive, semantic processing. PMID:25491206

Shimotake, Akihiro; Matsumoto, Riki; Ueno, Taiji; Kunieda, Takeharu; Saito, Satoru; Hoffman, Paul; Kikuchi, Takayuki; Fukuyama, Hidenao; Miyamoto, Susumu; Takahashi, Ryosuke; Ikeda, Akio; Lambon Ralph, Matthew A

2014-12-01

261

Intercalation of Hydrogen Phosphate Into Mg/Al-LAYERED Double Hydroxides with Dbs  

NASA Astrophysics Data System (ADS)

Intercalation of hydrogen phosphate (HPO4) into Mg/Al-Layered Double Hydroxides (LDH) with DodecylBenzeneSulfonate (DBS) was investigated with regard to anion exchange, rehydration and a combination of delamination and anion exchange. HPO4 could not be intercalated into the interlayer space of LDH with DBS when using either anion exchange or rehydration methods. However, HPO4 was successfully intercalated into the Mg/Al-LDH using a combination of delamination and anion exchange methods.

Shimamura, Akihiro; Jones, Mark I.; Metson, James B.

262

Deep brain stimulation of the human reward system for major depression--rationale, outcomes and outlook.  

PubMed

Deep brain stimulation (DBS) as a putative approach for treatment-resistant depression (TRD) has now been researched for about a decade. Several uncontrolled studies--all in relatively small patient populations and different target regions-have shown clinically relevant antidepressant effects in about half of the patients and very recently, DBS to a key structure of the reward system, the medial forebrain bundle, has yielded promising results within few days of stimulation and at much lower stimulation intensities. On the downside, DBS procedures in regions are associated with surgical risks (eg, hemorrhage) and psychiatric complications (suicidal attenuation, hypomania) as well as high costs. This overview summarizes research on the mechanisms of brain networks with respect to psychiatric diseases and--as a novelty--extrapolates to the role of the reward system in DBS for patients with treatment-resistant depression. It further evaluates relevant methodological aspects of today's research in DBS for TRD. On the scientific side, the reward system has an important yet clearly under-recognized role in both neurobiology and treatment of depression. On the methodological side of DBS research in TRD, better animal models are clearly needed to explain clinical effects of DBS in TRD. Larger sample sizes, long-term follow-up and designs including blinded sham control are required to draw final conclusions on efficacy and side effects. Practical research issues cover study design, patient tracking, and the discussion of meaningful secondary outcome measures. PMID:24513970

Schlaepfer, Thomas E; Bewernick, Bettina H; Kayser, Sarah; Hurlemann, Rene; Coenen, Volker A

2014-05-01

263

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. PMID:20657744

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

264

Effects of Medication and Subthalamic Nucleus Deep Brain Stimulation on Tongue Movements in Speakers with Parkinson's Disease Using Electropalatography: A Pilot Study  

ERIC Educational Resources Information Center

Parkinson's disease (PD) affects speech in the majority of patients. Subthalamic nucleus deep brain stimulation (STN-DBS) is particularly effective in reducing tremor and rigidity. However, its effect on speech is variable. The aim of this pilot study was to quantify the effects of bilateral STN-DBS and medication on articulation, using…

Hartinger, Mariam; Tripoliti, Elina; Hardcastle, William J.; Limousin, Patricia

2011-01-01

265

Rapid eye movement sleep behavior disorder after bilateral subthalamic stimulation in Parkinson's disease.  

PubMed

The effect of subthalamic nucleus (STN) deep brain stimulation (DBS) on rapid eye movement sleep behavior disorder (RBD) in Parkinson's disease (PD) is not well known. We evaluated the change in the incidence of probable RBD after bilateral STN DBS in PD patients. Ninety patients with PD treated with bilateral STN DBS underwent retrospective assessment of RBD by interview before and after DBS. Forty-seven (52.2%) of the 90 patients had RBD preoperatively. RBD was resolved only in one patient and persisted in 46 patients at 1year after DBS. RBD developed de novo in 16 patients (de novo RBD group) within 1year after DBS, resulting in 62 (68.9%) of the 90 patients having RBD 1year after DBS. Patients with RBD at any time within 1year after DBS (RBD group, n=63) were older than the patients without RBD (non-RBD group, n=27). The sum of the Unified Parkinson Disease Rating Scale (UPDRS) axial score for the "on" state was lower in the RBD group than in the non-RBD group after DBS (p=0.029). Comparing the de novo RBD group and non-RBD group, the UPDRS Part III and total score and the levodopa equivalent daily doses for the "on" states decreased more in the de novo RBD group than in the non-RBD group (p<0.05). The incidence of clinical RBD increased after bilateral STN DBS because de novo RBD developed and pre-existing RBD persisted after DBS. PMID:25439757

Kim, Young Eun; Jeon, Beom S; Paek, Sun-Ha; Yun, Ji Young; Yang, Hui-Jun; Kim, Han-Joon; Ehm, Gwanhee; Kim, Hee Jin; Lee, Jee-Young; Kim, Ji-Young

2015-02-01

266

Deep-brain stimulation associates with improved microvascular integrity in the subthalamic nucleus in Parkinson's disease.  

PubMed

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has become an accepted treatment for motor symptoms in a subset of Parkinson's disease (PD) patients. The mechanisms why DBS is effective are incompletely understood, but previous studies show that DBS targeted in brain structures other than the STN may modify the microvasculature. However, this has not been studied in PD subjects who have received STN-DBS. Here we investigated the extent and nature of microvascular changes in post-mortem STN samples from STN-DBS PD patients, compared to aged controls and PD patients who had not been treated with STN-DBS. We used immunohistochemical and immunofluorescent methods to assess serial STN-containing brain sections from PD and STN-DBS PD cases, compared to similar age controls using specific antibodies to detect capillaries, an adherens junction and tight junction-associated proteins as well as activated microglia. Cellular features in stained sections were quantified by confocal fluorescence microscopy and stereological methods in conjunction with in vitro imaging tools. We found significant upregulation of microvessel endothelial cell thickness, length and density but lowered activated microglia density and striking upregulation of all analysed adherens junction and tight junction-associated proteins in STN-DBS PD patients compared to non-DBS PD patients and controls. Moreover, in STN-DBS PD samples, expression of an angiogenic factor, vascular endothelial growth factor (VEGF), was significantly upregulated compared to the other groups. Our findings suggest that overexpressed VEGF and downregulation of inflammatory processes may be critical mechanisms underlying the DBS-induced microvascular changes. PMID:25533682

Pienaar, Ilse S; Lee, Cecilia Heyne; Elson, Joanna L; McGuinness, Louisa; Gentleman, Stephen M; Kalaria, Raj N; Dexter, David T

2015-02-01

267

Deep brain stimulation of globus pallidus interna, subthalamic nucleus, and pedunculopontine nucleus for Parkinson's disease: which target?  

PubMed

Deep brain stimulation (DBS) is an accepted therapy for people with Parkinson's disease (PD) motor symptoms that are refractory to pharmacologic therapy. Standard DBS targets are globus pallidus interna (GPi) and subthalamic nucleus (STN). The pedunculopontine nucleus (PPN) is being investigated as a novel target. Which target provides the best outcomes is unknown. The utility of GPi and STN as targets has been confirmed in numerous studies, including randomized comparisons of GPi DBS and STN DBS that demonstrated no difference in motor outcomes. DBS at either site improves appendicular motor symptoms, but beneficial effects on axial manifestations of PD such as postural instability or gait dysfunction (PIGD) are less apparent. PPN has been introduced as a DBS target due to failure of GPi and STN DBS to improve PIGD. Small observational studies indicate improved PIGD with PPN DBS, but small blinded trials show only subjective reduction in falls with no other impact on PIGD or other PD manifestations. No single DBS target is superior to the others. Each target offers relative advantages. Further studies are needed to better define the roles of each target, particularly PPN. Choice of target should be individualized according to providers' preferences and patients' needs. PMID:22166422

Follett, Kenneth A; Torres-Russotto, Diego

2012-01-01

268

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. PMID:22754509

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

2012-01-01

269

Programmed deep brain stimulation synchronizes VTA gamma band field potential and alleviates depressive-like behavior in rats.  

PubMed

Deep brain stimulation (DBS) significantly alleviates symptoms in various neurological disorders. Current research focuses on developing programmed stimulation protocols for customization to individual symptoms. However, the therapeutic mechanism of action of programmed DBS (pDBS) is poorly understood. We previously demonstrated that pDBS in the ventral tegmental area (VTA) normalizes molecular and behavioral abnormalities in the Flinders Sensitive Line (FSL) rat model for depression. Herein, we examined the effect of a short-duration, low-frequency DBS template on local field potential (LFP) synchronization patterns along the anterior-posterior axis of the VTA of FSL rats, and correlation of this effect with depressive-like behavior, as compared with non-programmed, continuous low-frequency DBS (npDBS). We used the wavelet phase coherence (WPC) measure for effective representation of time and frequency of LFP patterns, and the forced swim test to measure immobility (despair). Baseline WPC values were lower in FSLs as compared with SD controls, at the low and high gamma frequency range (above 30 Hz). Baseline immobility scores for FSL rats were higher than those of SD rats, while pDBS, and not npDBS, significantly reduced FSL immobility scores to control SD levels, up to day 14. pDBS also significantly increased the change (between baseline and day 14) in WPC values, in beta, low gamma and high gamma frequency ranges. The change in high gamma (60-100 Hz) WPC values correlated with improvement in depressive-like behavior. Our results suggest that programmed DBS of the VTA increases interaction among local neuronal populations, an effect that may underlie the normalization of depressive-like behavior. PMID:25497452

Gazit, Tomer; Friedman, Alexander; Lax, Elad; Samuel, Merav; Zahut, Roy; Katz, Moshe; Abraham, Lital; Tischler, Hadass; Teicher, Mina; Yadid, Gal

2015-04-01

270

A Non-Invasive Imaging Approach to Understanding Speech Changes following Deep Brain Stimulation in Parkinson’s Disease  

PubMed Central

Purpose To explore the use of non-invasive functional imaging and “virtual” lesion techniques to study the neural mechanisms underlying motor speech disorders in Parkinson’s disease. Here, we report the use of Positron Emission Tomography (PET) and transcranial magnetic stimulation (TMS) to explain exacerbated speech impairment following subthalamic nucleus deep brain stimulation (STN-DBS) in a patient with Parkinson’s disease. Method Perceptual and acoustic speech measures as well as cerebral blood flow (CBF) during speech as measured by PET were obtained with STN-DBS on and off. TMS was applied to a region in the speech motor network found to be abnormally active during DBS. Speech disruption by TMS was compared both perceptually and acoustically with that resulting from DBS on. Results Speech production was perceptually inferior and acoustically less contrastive during left STN stimulation compared to no stimulation. Increased neural activity in left dorsal premotor cortex (PMd) was observed during DBS on. “Virtual” lesioning of this region resulted in speech characterized by decreased speech segment duration, increased pause duration, and decreased intelligibility. Conclusions This case report provides evidence that impaired speech production accompanying STN-DBS may be resulting from unintended activation of PMd. Clinical application of functional imaging and TMS may lead to optimizing the delivery of STN-DBS to improve outcomes for speech production as well as general motor abilities. PMID:19029533

Narayana, Shalini; Jacks, Adam; Robin, Donald A.; Poizner, Howard; Zhang, Wei; Franklin, Crystal; Liotti, Mario; Vogel, Deanie; Fox, Peter T.

2009-01-01

271

Deep brain stimulation in Parkinson's disease: meta-analysis of randomized controlled trials.  

PubMed

Until recent years there has been no evidence from randomized controlled trials (RCTs) on the efficacy of deep brain stimulation (DBS) for Parkinson's disease (PD). This review and meta-analysis of RCTs describes the efficacy of DBS in improving motor signs, functionality and quality of life of PD patients. Several electronic databases were consulted up to April 2013. RCTs that compared DBS plus medication versus medication (alone or plus sham DBS) in PD patients were included. Outcome measures were motor function, waking time on good functioning without troublesome dyskinesias, levodopa-equivalent dose reduction, medication-induced complications, activities of daily living, health-related quality of life, and neurocognitive and psychiatric effects. Six RCTs (n = 1,184) that compared DBS plus medication versus medication alone were included. The results show that DBS significantly improves patients' symptoms, functionality and quality of life. Effects sizes are intense for the reduction of motor signs and improvement of functionality in the off-medication phase, in addition to the reduction of the required medication dose and its associated complications. Moderate effects were observed in the case of motor signs and time in good functionality in the on-medication phase, in addition to the quality of life. Although the number of RCTs obtained is small, the total sample size is relatively large, confirming the efficacy of DBS in the control of motor signs and improvement of patients' functionality and quality of life. More controlled research is required on the neurocognitive and psychiatric effects of DBS. PMID:24487826

Perestelo-Pérez, L; Rivero-Santana, A; Pérez-Ramos, J; Serrano-Pérez, P; Panetta, J; Hilarion, P

2014-11-01

272

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. PMID:23991221

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

2013-01-01

273

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

PubMed Central

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

274

Evaluation of Sex-Specific Gene Expression in Archived Dried Blood Spots (DBS)  

PubMed Central

Screening newborns for treatable serious conditions is mandated in all US states and many other countries. After screening, Guthrie cards with residual blood (whole spots or portions of spots) are typically stored at ambient temperature in many facilities. The potential of archived dried blood spots (DBS) for at-birth molecular studies in epidemiological and clinical research is substantial. However, it is also challenging as analytes from DBS may be degraded due to preparation and storage conditions. We previously reported an improved assay for obtaining global RNA gene expression from blood spots. Here, we evaluated sex-specific gene expression and its preservation in DBS using oligonucleotide microarray technology. We found X inactivation-specific transcript (XIST), lysine-specific demethylase 5D (KDM5D) (also known as selected cDNA on Y, homolog of mouse (SMCY)), uncharacterized LOC729444 (LOC729444), and testis-specific transcript, Y-linked 21 (TTTY21) to be differentially-expressed by sex of the newborn. Our finding that trait-specific RNA gene expression is preserved in unfrozen DBS, demonstrates the technical feasibility of performing molecular genetic profiling using such samples. With millions of DBS potentially available for research, we see new opportunities in using newborn molecular gene expression to better understand molecular pathogenesis of perinatal diseases. PMID:22949818

Resau, James H.; Ho, Nhan T.; Dykema, Karl; Faber, Matthew S.; Busik, Julia V.; Nickolov, Radoslav Z.; Furge, Kyle A.; Paneth, Nigel; Jewell, Scott; Khoo, Sok Kean

2012-01-01

275

Psychosis from subthalamic nucleus deep brain stimulator lesion effect  

PubMed Central

Background: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) in particular is highly effective in relieving symptoms of Parkinson's disease (PD). However, it can also have marked psychiatric side effects, including delirium, mania, and psychosis. The etiologies of those effects are not well-understood, and both surgeons and consulting psychiatrists are in need of treatment strategies. Case Description: Two patients with young onset of PD and without significant prior psychiatric problems presented for bilateral STN DBS when medications became ineffective. Both had uneventful operative courses but developed florid psychosis 1-2 weeks later, before stimulator activation. Neither showed signs of delirium, but both required hospitalization, and one required treatment with a first-generation antipsychotic drug. Use of that drug did not worsen PD symptoms, contrary to usual expectations. Conclusion: These cases describe a previously unreported post-DBS syndrome in which local tissue reaction to lead implantation produces psychosis even without electrical stimulation of subcortical circuits. The lesion effect also appears to have anti-Parkinsonian effects that may allow the safe use of otherwise contraindicated medications. These cases have implications for management of PD DBS patients postoperatively, and may also be relevant as DBS is further used in other brain regions to treat behavioral disorders. PMID:23493632

Widge, Alik S.; Agarwal, Pinky; Giroux, Monique; Farris, Sierra; Kimmel, Ryan J.; Hebb, Adam O.

2013-01-01

276

Stimulation region within the globus pallidus does not affect verbal fluency performance  

PubMed Central

Background Subthalamic (STN) and globus pallidus (GP) deep brain stimulation (DBS) have been previously shown to be efficacious in the treatment of selected Parkinson patients with medication resistant motor fluctuations and/or tremor. Deep brain stimulation of the STN has been implicated with more cognitive and mood side effects as compared to GP DBS; however, more studies are needed to better understand possible target differences. Previously, Mikos et al. (1) reported worsening of verbal fluency depending on the stimulation location within the STN region. Objective/Hypothesis The current study applied the methods used by Mikos et al. (2011) to a different sample of Parkinson patients who underwent GP DBS. Based on differences in the size and functional somatotopy between structures (GP 412mm3 vs. STN 167mm3), we hypothesized that there would be a less robust relationship between volume of tissue activated, fluency performance, and stimulation contact within the GP compared to what was reported in the STN. Methods Patient-specific DBS models were created and the volume of tissue activated within the GP was calculated. These data were correlated with patients’ verbal fluency performance at dorsal, optimal, and ventral stimulation contacts. Results In contrast to STN findings, there was no significant relationship between stimulation location and fluency performance in patients who received GP DBS. Conclusion(s) These results suggest that fluency may be less sensitive to stimulation location in the globus pallidus and thus there may be more flexibility in terms of DBS programming with GP DBS patients. PMID:22766102

Dietz, Jenna; Noecker, Angela M.; McIntyre, Cameron C.; Bowers, Dawn; Foote, Kelly D.; Okun, Michael S.

2012-01-01

277

Acute effects of thalamic deep brain stimulation and thalamotomy on sensorimotor cortex local field potentials in essential tremor  

PubMed Central

Objective Essential tremor (ET) is characterized by an action tremor believed to be due to excessive theta–alpha activity in the cerebello–thalamo–cortical system. This study aimed to test the hypothesis that therapeutic thalamic stimulation in patients with ET decreases theta–alpha oscillatory activity in primary motor (M1) and sensory (S1) cortices. Methods During surgical treatment of ET in 10 patients, an electrocorticography (ECoG) strip electrode was placed temporarily over the arm region of M1 and S1. Local field potentials (LFP) were recorded at rest, during a tremor-inducing posture, during acute therapeutic thalamic stimulation, and following therapeutic thalamotomy (three patients). Power spectral density (PSD) was calculated using the Fast Fourier Transform. Results At rest, alpha activity (8–13 Hz) in M1 was significantly decreased during high-frequency stimulation, while theta activity (4–8 Hz) decreased in S1. Following thalamotomy, theta and beta (13–30 Hz) was increased in M1. Induction of postural tremor reduced M1 theta, alpha and beta activity compared to the resting state. Conclusions High-frequency thalamic deep brain stimulation (DBS) significantly reduces alpha oscillatory activity in the primary motor cortex of patients with ET, though this change is probably not critical for therapeutic efficacy. Significance We demonstrate that ECoG can be effectively used to study the effect of subcortical stimulation on cortical oscillations. PMID:22633916

Air, Ellen L.; Ryapolova-Webb, Elena; de Hemptinne, Coralie; Ostrem, Jill L.; Galifianakis, Nicholas B.; Larson, Paul S.; Chang, Edward F.; Starr, Philip A.

2012-01-01

278

Deep brain stimulation of the inferior colliculus: A possible animal model to study paradoxical kinesia observed in some parkinsonian patients?  

PubMed

The inferior colliculus (IC) plays an important role in the normal processing of the acoustic message and is also involved in the filtering of acoustic stimuli of aversive nature. The neural substrate of the IC can also influence haloperidol-induced catalepsy. Considering that (i) paradoxical kinesia, observed in some parkinsonian patients, seems to be dependent of their emotional state and (ii) deep brain stimulation (DBS) represents an alternative therapeutic route for the relief of parkinsonian symptoms, the present study investigated the consequence of DBS at the IC on the catalepsy induced by haloperidol in rats. Additionally, we investigated if DBS of the IC can elicit motor responses in anesthetized rats and whether DBS elicits distinct neural firing patterns of activity at the dorsal cortex (DCIC) or central nucleus (CNIC) of the IC. A significant reduction of the catalepsy response was seen in rats previously given haloperidol and receiving DBS at the IC. In addition, electrical stimulation to the ventral part of the CNIC induced immediate motor responses in anesthetized rats. The neuronal spontaneous activity was higher at the ventral part of the CNIC than the dorsal part. DBS to the ventral part but not to the dorsal part of the CNIC increased the spike rate at neurons a few hundred microns away from the stimulation site. It is possible that the IC plays a role in the sensorimotor gating activated by emotional stimuli, and that DBS at the IC can be a promising new animal model to study paradoxical kinesia in rats. PMID:25446814

Melo-Thomas, Liana; Thomas, Uwe

2015-02-15

279

Mixed Effects of Deep Brain Stimulation on Depressive Symptomatology in Parkinson’s Disease: A Review of Randomized Clinical Trials  

PubMed Central

Although ~50% of patients with Parkinson’s disease (PD) experience depression, treatment for this important and debilitating comorbidity is relatively understudied. Deep brain stimulation (DBS) has been increasingly utilized for the management of tremors in progressive PD. Several preliminary studies have shown the potential benefit of DBS for non-motor PD symptoms such as depression. Here, we critically evaluate seven recent randomized clinical trials of the effectiveness of DBS in reducing depressive symptomatology among individuals with PD. Findings are mixed for the effectiveness of DBS as a treatment for depression in PD. Our review suggests that this is due, in large part, to the anatomical and methodological variation across the DBS studies. We provide a comprehensive discussion of these variations and highlight the need to conduct larger, more controlled studies aimed specifically at evaluating the treatment of depression in PD patients. PMID:25157240

Gökbayrak, N. Simay; Piryatinsky, Irene; Gavett, Rebecca A.; Ahmed, Omar J.

2014-01-01

280

Pathways of Translation: Deep Brain Stimulation  

PubMed Central

Electrical stimulation of the brain has a 2000 year history. Deep brain stimulation (DBS), one form of neurostimulation, is a functional neurosurgical approach in which a high frequency electric current stimulates targeted brain structures for therapeutic benefit. It is an effective treatment for certain neuropathologic movement disorders and an emerging therapy for psychiatric conditions and epilepsy. Its translational journey did not follow the typical bench-to-bedside path, but rather reversed the process. The shift from ancient and medieval folkloric remedy to accepted medical practice began with independent discoveries about electricity during the 17th century and was fostered by technological advances of the 20th. In this article we review that journey and discuss how the quest to expand its applications and continue to improve outcomes is taking DBS from the bedside back to the bench. PMID:24330698

Gionfriddo, Michael R.; Greenberg, Alexandra J.; Wahegaonkar, Abhijeet L.; Lee, Kendall H.

2014-01-01

281

Potential predictors for the amount of intra-operative brain shift during deep brain stimulation surgery  

NASA Astrophysics Data System (ADS)

A number of groups have reported on the occurrence of intra-operative brain shift during deep brain stimulation (DBS) surgery. This has a number of implications for the procedure including an increased chance of intra-cranial bleeding and complications due to the need for more exploratory electrodes to account for the brain shift. It has been reported that the amount of pneumocephalus or air invasion into the cranial cavity due to the opening of the dura correlates with intraoperative brain shift. Therefore, pre-operatively predicting the amount of pneumocephalus expected during surgery is of interest toward accounting for brain shift. In this study, we used 64 DBS patients who received bilateral electrode implantations and had a post-operative CT scan acquired immediately after surgery (CT-PI). For each patient, the volumes of the pneumocephalus, left ventricle, right ventricle, third ventricle, white matter, grey matter, and cerebral spinal fluid were calculated. The pneumocephalus was calculated from the CT-PI utilizing a region growing technique that was initialized with an atlas-based image registration method. A multi-atlas-based image segmentation method was used to segment out the ventricles of each patient. The Statistical Parametric Mapping (SPM) software package was utilized to calculate the volumes of the cerebral spinal fluid (CSF), white matter and grey matter. The volume of individual structures had a moderate correlation with pneumocephalus. Utilizing a multi-linear regression between the volume of the pneumocephalus and the statistically relevant individual structures a Pearson's coefficient of r = 0.4123 (p = 0.0103) was found. This study shows preliminary results that could be used to develop a method to predict the amount of pneumocephalus ahead of the surgery.

Datteri, Ryan; Pallavaram, Srivatsan; Konrad, Peter E.; Neimat, Joseph S.; D'Haese, Pierre-François; Dawant, Benoit M.

2011-03-01

282

Globus Pallidus Interna Deep Brain Stimulation in a Patient with Medically Intractable Meige Syndrome  

PubMed Central

Medical therapies in patients with Meige syndrome, including botulinum toxin injection, have been limited because of incomplete response or adverse side effects. We evaluated a patient with Meige syndrome who was successfully treated with deep brain stimulation (DBS) in the globus pallidus interna (GPi). This case report and other previous reports suggest that bilateral GPi DBS may be an effective treatment for medically refractory Meige syndrome, without significant adverse effects. PMID:25360233

Bae, Dae-Woong; Son, Byung-chul; Kim, Joong-Seok

2014-01-01

283

Deep Brain Stimulation of the Nucleus Accumbens Shell Attenuates Cocaine Reinstatement through Local and Antidromic Activation  

PubMed Central

Accumbal deep brain stimulation (DBS) is a promising therapeutic modality for the treatment of addiction. Here, we demonstrate that DBS in the nucleus accumbens shell, but not the core, attenuates cocaine priming-induced reinstatement of drug seeking, an animal model of relapse, in male Sprague Dawley rats. Next, we compared DBS of the shell with pharmacological inactivation. Results indicated that inactivation using reagents that influenced (lidocaine) or spared (GABA receptor agonists) fibers of passage blocked cocaine reinstatement when administered into the core but not the shell. It seems unlikely, therefore, that intrashell DBS influences cocaine reinstatement by inactivating this nucleus or the fibers coursing through it. To examine potential circuit-wide changes, c-Fos immunohistochemistry was used to examine neuronal activation following DBS of the nucleus accumbens shell. Intrashell DBS increased c-Fos induction at the site of stimulation as well as in the infralimbic cortex, but had no effect on the dorsal striatum, prelimbic cortex, or ventral pallidum. Recent evidence indicates that accumbens DBS antidromically stimulates axon terminals, which ultimately activates GABAergic interneurons in cortical areas that send afferents to the shell. To test this hypothesis, GABA receptor agonists (baclofen/muscimol) were microinjected into the anterior cingulate, and prelimbic or infralimbic cortices before cocaine reinstatement. Pharmacological inactivation of all three medial prefrontal cortical subregions attenuated the reinstatement of cocaine seeking. These results are consistent with DBS of the accumbens shell attenuating cocaine reinstatement via local activation and/or activation of GABAergic interneurons in the medial prefrontal cortex via antidromic stimulation of cortico-accumbal afferents. PMID:24005296

White, Samantha L.; Hopkins, Thomas J.; Guercio, Leonardo A.; Espallergues, Julie; Berton, Olivier; Schmidt, Heath D.; Pierce, R. Christopher

2013-01-01

284

Are Complications Less Common in Deep Brain Stimulation than in Ablative Procedures for Movement Disorders?  

Microsoft Academic Search

The side effects and complications of deep brain stimulation (DBS) and ablative lesions for tremor and Parkinson’s disease were recorded in 256 procedures (129 DBS and 127 lesions). Perioperative complications (seizures, haemorrhage, confusion) were rare and did not differ between the two groups. The rate of hardware-related complications was 17.8%. In ventral intermediate (Vim) thalamotomies, the rate of side effects

Patric Blomstedt; Marwan I. Hariz

2006-01-01

285

Changes in Vowel Articulation with Subthalamic Nucleus Deep Brain Stimulation in Dysarthric Speakers with Parkinson's Disease  

PubMed Central

Purpose. To investigate changes in vowel articulation with the electrical deep brain stimulation (DBS) of the subthalamic nucleus (STN) in dysarthric speakers with Parkinson's disease (PD). Methods. Eight Quebec-French speakers diagnosed with idiopathic PD who had undergone STN DBS were evaluated ON-stimulation and OFF-stimulation (1 hour after DBS was turned off). Vowel articulation was compared ON-simulation versus OFF-stimulation using acoustic vowel space and formant centralization ratio, calculated with the first (F1) and second formant (F2) of the vowels /i/, /u/, and /a/. The impact of the preceding consonant context on articulation, which represents a measure of coarticulation, was also analyzed as a function of the stimulation state. Results. Maximum vowel articulation increased during ON-stimulation. Analyses also indicate that vowel articulation was modulated by the consonant context but this relationship did not change with STN DBS. Conclusions. Results suggest that STN DBS may improve articulation in dysarthric speakers with PD, in terms of range of movement. Optimization of the electrical parameters for each patient is important and may lead to improvement in speech fine motor control. However, the impact on overall speech intelligibility may still be small. Clinical considerations are discussed and new research avenues are suggested. PMID:25400977

Langlois, Mélanie; Prud'Homme, Michel; Cantin, Léo

2014-01-01

286

21 CFR 882.1310 - Cortical electrode.  

...Identification. A cortical electrode is an electrode which is temporarily placed on the surface of the brain for stimulating the brain or recording the brain's electrical activity. (b) Classification. Class II (performance...

2014-04-01

287

21 CFR 882.1310 - Cortical electrode.  

Code of Federal Regulations, 2010 CFR

...Identification. A cortical electrode is an electrode which is temporarily placed on the surface of the brain for stimulating the brain or recording the brain's electrical activity. (b) Classification. Class II (performance...

2010-04-01

288

Long-term results of a multicenter study on subthalamic and pallidal stimulation in Parkinson's disease.  

PubMed

We report the 5 to 6 year follow-up of a multicenter study of bilateral subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) in advanced Parkinson's disease (PD) patients. Thirty-five STN patients and 16 GPi patients were assessed at 5 to 6 years after DBS surgery. Primary outcome measure was the stimulation effect on the motor Unified Parkinson's Disease Rating Scale (UPDRS) assessed with a prospective cross-over double-blind assessment without medications (stimulation was randomly switched on or off). Secondary outcomes were motor UPDRS changes with unblinded assessments in off- and on-medication states with and without stimulation, activities of daily living (ADL), anti-PD medications, and dyskinesias. In double-blind assessment, both STN and GPi DBS were significantly effective in improving the motor UPDRS scores (STN, P < 0.0001, 45.4%; GPi, P = 0.008, 20.0%) compared with off-stimulation, regardless of the sequence of stimulation. In open assessment, both STN- and GPi-DBS significantly improved the off-medication motor UPDRS when compared with before surgery (STN, P < 0.001, 50.5%; GPi, P = 0.002, 35.6%). Dyskinesias and ADL were significantly improved in both groups. Anti-PD medications were significantly reduced only in the STN group. Adverse events were more frequent in the STN group. These results confirm the long-term efficacy of STN and GPi DBS in advanced PD. Although the surgical targets were not randomized, there was a trend to a better outcome of motor signs in the STN-DBS patients and fewer adverse events in the GPi-DBS group. PMID:20213817

Moro, Elena; Lozano, Andres M; Pollak, Pierre; Agid, Yves; Rehncrona, Stig; Volkmann, Jens; Kulisevsky, Jaime; Obeso, Jose A; Albanese, Alberto; Hariz, Marwan I; Quinn, Niall P; Speelman, Jans D; Benabid, Alim L; Fraix, Valerie; Mendes, Alexandre; Welter, Marie-Laure; Houeto, Jean-Luc; Cornu, Philippe; Dormont, Didier; Tornqvist, Annalena L; Ekberg, Ron; Schnitzler, Alfons; Timmermann, Lars; Wojtecki, Lars; Gironell, Andres; Rodriguez-Oroz, Maria C; Guridi, Jorge; Bentivoglio, Anna R; Contarino, Maria F; Romito, Luigi; Scerrati, Massimo; Janssens, Marc; Lang, Anthony E

2010-04-15

289

Instrumentation to Record Evoked Potentials for Closed-Loop Control of Deep Brain Stimulation  

PubMed Central

Closed-loop deep brain stimulation (DBS) systems offer promise in relieving the clinical burden of stimulus parameter selection and improving treatment outcomes. In such a system, a feedback signal is used to adjust automatically stimulation parameters and optimize the efficacy of stimulation. We explored the feasibility of recording electrically evoked compound action potentials (ECAPs) during DBS for use as a feedback control signal. A novel instrumentation system was developed to suppress the stimulus artifact and amplify the small magnitude, short latency ECAP response during DBS with clinically relevant parameters. In vitro testing demonstrated the capabilities to increase the gain by a factor of 1,000x over a conventional amplifier without saturation, reduce distortion of mock ECAP signals, and make high fidelity recordings of mock ECAPs at latencies of only 0.5 ms following DBS pulses of 50 to 100 ?s duration. Subsequently, the instrumentation was used to make in vivo recordings of ECAPs during thalamic DBS in cats, without contamination by the stimulus artifact. The signal characteristics were similar across three experiments, suggesting common neural activation patterns. The ECAP recordings enabled with this novel instrumentation may provide insight into the type and spatial extent of neural elements activated during DBS, and could serve as feedback control signals for closed-loop systems. PMID:22255894

Kent, Alexander R.; Grill, Warren M.

2012-01-01

290

Validation of CT-MRI fusion for intraoperative assessment of stereotactic accuracy in DBS surgery.  

PubMed

Deep brain stimulation is typically performed with intraoperative microelectrode recording and test stimulation for target confirmation. Recent studies have shown accurate, clinically efficacious results after lead placement without microelectrode recording or test stimulation, using interventional magnetic resonance imaging (MRI) or intraoperative computed tomography (CT; iCT) for verification of accuracy. The latter relies on CT-MRI fusion. To validate CT-MRI fusion in this setting, we compared stereotactic coordinates determined intraoperatively using CT-MRI fusion with those obtained on postoperative MRI. Deep brain stimulation electrodes were implanted with patients under general anesthesia. Direct targeting was performed on preoperative MRI, which was merged with preimplantation iCT images for stereotactic registration and postimplantation iCT images for accuracy confirmation. Magnetic resonance imaging was obtained 6 weeks postoperatively for comparison. Postoperative MRI was obtained for 48 patients, with 94 leads placed over a 1-year period. Vector error of the targeted contact relative to the initial plan was 1.1?±?0.7 mm on iCT and 1.6?±?0.7 mm on postoperative MRI. Variance comparisons (F-tests) showed that the discrepancy between iCT- and postoperative MRI-determined errors was attributable to measurement error on postoperative MRI, as detected in inter-rater reliability testing. In multivariate analysis, improved lead placement accuracy was associated with frame-based stereotaxy with the head of the bed at 0° compared with frameless stereotaxy with the head of the bed at 30° (P?=?0.037). Intraoperative CT can be used to determine lead placement accuracy in deep brain stimulation surgery. The discrepancy between coordinates determined intraoperatively by CT-MRI fusion and postoperatively by MRI can be accounted for by inherent measurement error. © 2014 International Parkinson and Movement Disorder Society. PMID:25377213

Mirzadeh, Zaman; Chapple, Kristina; Lambert, Meg; Dhall, Rohit; Ponce, Francisco A

2014-12-01

291

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...

292

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. PMID:24855615

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

2014-01-01

293

IN BEHAVIORAL NEUROSCIENCE Deep brain stimulation of the ventral striatum increases BDNF in the fear  

E-print Network

IN BEHAVIORAL NEUROSCIENCE Deep brain stimulation of the ventral striatum increases BDNF.frontiersin.org #12;1 Deep brain stimulation of the ventral striatum increases BDNF in1 the fear extinction 6 Running Tittle: Striatal DBS increases prefrontal BDNF7 8 9 10 Keywords: anxiety disorders

Quirk, Gregory J.

294

Changes in GABA and glutamate concentrations during memory tasks in patients with Parkinson’s disease undergoing DBS surgery  

PubMed Central

Until now direct neurochemical measurements during memory tasks have not been accomplished in the human basal ganglia. It has been proposed, based on both functional imaging studies and psychometric testing in normal subjects and in patients with Parkinson’s disease (PD), that the basal ganglia is responsible for the performance of feedback-contingent implicit memory tasks. To measure neurotransmitters, we used in vivo microdialysis during deep brain stimulation (DBS) surgery. We show in the right subthalamic nucleus (STN) of patients with PD a task-dependent change in the concentrations of glutamate and GABA during an implicit memory task relative to baseline, while no difference was found between declarative memory tasks. The five patients studied had a significant decrease in the percent concentration of GABA and glutamate during the performance of the weather prediction task (WPT). We hypothesize, based on current models of basal ganglia function, that this decrease in the concentration is consistent with expected dysfunction in basal ganglia networks in patients with PD. PMID:24639638

Buchanan, Robert J.; Darrow, David P.; Meier, Kevin T.; Robinson, Jennifer; Schiehser, Dawn M.; Glahn, David C.; Nadasdy, Zoltan

2014-01-01

295

[Electric brain stimulation for epilepsy therapy].  

PubMed

Attempts to control epileptic seizures by electrical brain stimulation have been performed for 50 years. Many different stimulation targets and methods have been investigated. Vagal nerve stimulation (VNS) is now approved for the treatment of refractory epilepsies by several governmental authorities in Europe and North America. However, it is mainly used as a palliative method when patients do not respond to medical treatment and epilepsy surgery is not possible. Numerous studies of the effect of deep brain stimulation (DBS) on epileptic seizures have been performed and almost invariably report remarkable success. However, a limited number of controlled studies failed to show a significant effect. Repetitive transcranial magnetic stimulation (rTMS) also was effective in open studies, and controlled studies are now being carried out. In addition, several uncontrolled reports describe successful treatment of refractory status epilepticus with electroconvulsive therapy (ECT). In summary, with the targets and stimulation parameters investigated so far, the effects of electrical brain stimulation on seizure frequency have been moderate at best. In the animal laboratory, we are now testing high-intensity, low-frequency stimulation of white matter tracts directly connected to the epileptogenic zone (e.g., fornix, corpus callosum) as a new methodology to increase the efficacy of DBS ("overdrive method"). PMID:12904868

Kellinghaus, C; Loddenkemper, T; Möddel, G; Tergau, F; Lüders, J; Lüdemann, P; Nair, D R; Lüders, H O

2003-08-01

296

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

297

Ethical concerns regarding commercialization of deep brain stimulation for obsessive compulsive disorder.  

PubMed

The United States Food and Drug Administration's recent approval of the commercial use of Deep Brain Stimulation (DBS) as a treatment for Obsessive Compulsive Disorder (OCD) will be discussed within the context of the existing USA regulatory framework. The purpose will be to illustrate the current lack of regulation and oversight of the DBS market, which has resulted in the violation of basic ethical norms. The discussion will focus on: 1) the lack of available evidence on procedural safety and efficacy, 2) the numerous conflicts of interest held by research investigators, and 3) the ambiguity of both aforementioned categories due to an inherent lack of transparency in the research. It is argued that in order to address these issues, ethical analyses of DBS for psychiatric disorders must include the role of the industry forces that have become the primary impetus for this research. As such, DBS for OCD serves as an important case example in studies of neurotechnology and innovative surgery. PMID:21535063

Erickson-Davis, Cordelia

2012-10-01

298

Deep brain stimulation in movement disorders.  

PubMed

Deep brain stimulation (DBS) is used for advanced and medically intractable patients with Parkinson's disease (PD), essential tremor (ET), and dystonia who meet strict criteria after a detailed motor, cognitive, and psychiatric evaluation. The potential targets are the ventral intermediate nucleus (VIM) of the thalamus for tremor, the globus pallidus interna (GPI) and the subthalamic nucleus (STN) for PD, and GPI for dystonia. The optimal target for PD has not been determined yet, although STN DBS has been performed more frequently in recent years. The mechanism of DBS effect is believed to be associated with disruption of pathological network activity in the cortico-basal ganglia-thalamic circuits by affecting the firing rates and bursting patterns of neurons and synchronized oscillatory activity of neuronal networks. Good candidates should be free of dementia, major psychiatric disorders, structural brain lesions, and important general medical problems. Although the risk for complications with DBS is less than with lesioning techniques, there is still a small risk for major complications associated with surgery. Bilateral procedures are more likely to cause problems with speech, cognition, and gait. PMID:17390262

Uc, Ergun Y; Follett, Kenneth A

2007-04-01

299

Subthalamic nucleus stimulation in Parkinson's disease  

Microsoft Academic Search

The aim of the present study was to assess the efficacy and safety of chronic subthalamic nucleus deep-brain stimulation\\u000a (STN-DBS) in patients with Parkinson's disease (PD). 18 consecutive severely affected PD patients were included (mean age,\\u000a SD: 56.9±6 years; mean disease duration: 13.5±4.4 years). All the patients were evaluated clinically before and 6 months after\\u000a the surgical procedure using the

S. Thobois; P. Mertens; M. Guenot; M. Hermier; H. Mollion; M. Bouvard; G. Chazot; E. Broussolle; M. Sindou

2002-01-01

300

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. PMID:24860415

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

2014-01-01

301

Target coverage and selectivity in field steering brain stimulation.  

PubMed

Deep Brain Stimulation (DBS) is an established treatment in Parkinson's Disease. The target area is defined based on the state and brain anatomy of the patient. The stimulation delivered via state-of-the-art DBS leads that are currently in clinical use is difficult to individualize to the patient particularities. Furthermore, the electric field generated by such a lead has a limited selectivity, resulting in stimulation of areas adjacent to the target and thus causing undesirable side effects. The goal of this study is, using actual clinical data, to compare in silico the stimulation performance of a symmetrical generic lead to a more versatile and adaptable one allowing, in particular, for asymmetric stimulation. The fraction of the volume of activated tissue in the target area and the fraction of the stimulation field that spreads beyond it are computed for a clinical data set of patients in order to quantify the lead performance. The obtained results suggest that using more versatile DBS leads might reduce the stimulation area beyond the target and thus lessen side effects for the same achieved therapeutical effect. PMID:25570011

Cubo, Ruben; Astrom, Mattias; Medvedev, Alexander

2014-08-01

302

Coordinate-Based Lead Location Does Not Predict Parkinson's Disease Deep Brain Stimulation Outcome  

PubMed Central

Background Effective target regions for deep brain stimulation (DBS) in Parkinson's disease (PD) have been well characterized. We sought to study whether the measured Cartesian coordinates of an implanted DBS lead are predictive of motor outcome(s). We tested the hypothesis that the position and trajectory of the DBS lead relative to the mid-commissural point (MCP) are significant predictors of clinical outcomes. We expected that due to neuroanatomical variation among individuals, a simple measure of the position of the DBS lead relative to MCP (commonly used in clinical practice) may not be a reliable predictor of clinical outcomes when utilized alone. Methods 55 PD subjects implanted with subthalamic nucleus (STN) DBS and 41 subjects implanted with globus pallidus internus (GPi) DBS were included. Lead locations in AC-PC space (x, y, z coordinates of the active contact and sagittal and coronal entry angles) measured on high-resolution CT-MRI fused images, and motor outcomes (Unified Parkinson's Disease Rating Scale) were analyzed to confirm or refute a correlation between coordinate-based lead locations and DBS motor outcomes. Results Coordinate-based lead locations were not a significant predictor of change in UPDRS III motor scores when comparing pre- versus post-operative values. The only potentially significant individual predictor of change in UPDRS motor scores was the antero-posterior coordinate of the GPi lead (more anterior lead locations resulted in a worse outcome), but this was only a statistical trend (p<.082). Conclusion The results of the study showed that a simple measure of the position of the DBS lead relative to the MCP is not significantly correlated with PD motor outcomes, presumably because this method fails to account for individual neuroanatomical variability. However, there is broad agreement that motor outcomes depend strongly on lead location. The results suggest the need for more detailed identification of stimulation location relative to anatomical targets. PMID:24691109

Nestor, Kelsey A.; Jones, Jacob D.; Butson, Christopher R.; Morishita, Takashi; Jacobson, Charles E.; Peace, David A.; Chen, Dennis; Foote, Kelly D.; Okun, Michael S.

2014-01-01

303

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. PMID:21887135

Sironi, Vittorio A.

2011-01-01

304

Experimental investigations into a linearly polarized radial slot antenna for DBS TV in Australia  

Microsoft Academic Search

A hybrid theoretical\\/experimental approach to the design of radial line slot array (RLSA) antennas for receiving direct broadcast satellite (DBS) TV programs in Australia is presented. Using this approach, 0.4-m and 0.6-m diameter linearly polarized Ku-band prototype antennas were constructed and experimentally investigated. The 0.6-m prototype incorporates reflection cancelling slots, which allow it to overcome the inherent poor return loss

Paul W. Davis; Marek E. Bialkowski

1997-01-01

305

Quantitation of Tenofovir and Emtricitabine in Dried Blood Spots (DBS) with LC-MS/MS  

PubMed Central

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 2.5ng/mL to 1,000ng/mL for TFV and 2.5ng/mL to 5,000ng/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 versus center punches; and spot volumes of 10µL to 50µL. 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 versus plasma yielded r2 ? 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.

2013-01-01

306

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. PMID:24733973

Delaloye, Sibylle; Holtzheimer, Paul E.

2014-01-01

307

A table to be managed by a Scalable Distributed Database System (SD-DBS) should be able to horizontally scale  

E-print Network

(IAM) back to the client. Data in an IAM improve the image, avoiding at least to repeat the same error. It is obvious that building a full scale SD-DBS is a potentially very challenging task. We focus therefore

Risch, Tore

308

Electric stimulation of the tuberomamillary nucleus affects epileptic activity and sleep-wake cycle in a genetic absence epilepsy model.  

PubMed

Deep brain stimulation (DBS) is a promising approach for epilepsy treatment, but the optimal targets and parameters of stimulation are yet to be investigated. Tuberomamillary nucleus (TMN) is involved in EEG desynchronization-one of the proposed mechanisms for DBS action. We studied whether TMN stimulation could interfere with epileptic spike-wave discharges (SWDs) in WAG/Rij rats with inherited absence epilepsy and whether such stimulation would affect sleep-wake cycle. EEG and video registration were used to determine SWD occurrence and stages of sleep and wake during three-hours recording sessions. Stimulation (100Hz) was applied in two modes: closed-loop (with previously determined interruption threshold intensity) or open-loop mode (with 50% or 70% threshold intensity). Closed-loop stimulation successfully interrupted SWDs but elevated their number by 148±54% compared to baseline. It was accompanied by increase in number of episodes but not total duration of both active and passive wakefulness. Open-loop stimulation with amplitude 50% threshold did not change measured parameters, though 70% threshold stimulation reduced SWDs number by 40±9%, significantly raised the amount of active wakefulness and decreased the amount of both slow-wave and rapid eye movement sleep. These results suggest that the TMN is unfavorable as a target for DBS as its stimulation may cause alterations in sleep-wake cycle. A careful choosing of parameters and control of sleep-wake activity is necessary when applying DBS in epilepsy. PMID:25524851

Blik, Vitaliya

2015-01-01

309

Deep Brain Stimulation for Tremor Associated with Underlying Ataxia Syndromes: A Case Series and Discussion of Issues  

PubMed Central

Background Deep brain stimulation (DBS) has been utilized to treat various symptoms in patients suffering from movement disorders such as Parkinson's disease, dystonia, and essential tremor. Though ataxia syndromes have not been formally or frequently addressed with DBS, there are patients with ataxia and associated medication refractory tremor or dystonia who may potentially benefit from therapy. Methods A retrospective database review was performed, searching for cases of ataxia where tremor and/or dystonia were addressed by utilizing DBS at the University of Florida Center for Movement Disorders and Neurorestoration between 2008 and 2011. Five patients were found who had DBS implantation to address either medication refractory tremor or dystonia. The patient's underlying diagnoses included spinocerebellar ataxia type 2 (SCA2), fragile X associated tremor ataxia syndrome (FXTAS), a case of idiopathic ataxia (ataxia not otherwise specified [NOS]), spinocerebellar ataxia type 17 (SCA17), and a senataxin mutation (SETX). Results DBS improved medication refractory tremor in the SCA2 and the ataxia NOS patients. The outcome for the FXTAS patient was poor. DBS improved dystonia in the SCA17 and SETX patients, although dystonia did not improve in the lower extremities of the SCA17 patient. All patients reported a transient gait dysfunction postoperatively, and there were no reports of improvement in ataxia-related symptoms. Discussion DBS may be an option to treat tremor, inclusive of dystonic tremor in patients with underlying ataxia; however, gait and other symptoms may possibly be worsened. PMID:25120941

Oyama, Genko; Thompson, Amanda; Foote, Kelly D.; Limotai, Natlada; Abd-El-Barr, Muhammad; Maling, Nicholas; Malaty, Irene A.; Rodriguez, Ramon L.; Subramony, Sankarasubramoney H.; Ashizawa, Testuo; Okun, Michael S.

2014-01-01

310

Deep Brain Stimulation of the Antero-Medial Globus Pallidus Interna for Tourette Syndrome  

PubMed Central

Background We have previously reported the results of Deep Brain Stimulation (DBS) of the antero-medial globus pallidus interna (GPi) for severe Tourette Syndrome (TS) in 11 patients. We extend this case series to 17 patients and a longer follow-up to a maximum of 46 months. Methods 17 patients (14 male; mean age 29.1 years, range 17–51 years) with severe and medically intractable TS were implanted with Medtronic quadripolar electrodes bilaterally in the antero-medial GPi. The primary outcome measure was the Yale Global Tic Severity Scale (YGTSS). Secondary outcome measures included the Yale-Brown Obsessive Compulsive Scale, Hamilton Depression Rating Scale, Gilles de la Tourette Quality of Life Scale and Global Assessment of Functioning. Follow up was at one month, three months and finally at a mean 24.1 months (range 8–46 months) following surgery. Results Overall, there was a 48.3% reduction in motor tics and a 41.3% reduction in phonic tics at one month, and this improvement was maintained at final follow-up. 12 out of 17 (70.6%) patients had a>50% reduction in YGTSS score at final follow up. Only 8 patients required ongoing pharmacotherapy for tics post-surgery. Patients improved significantly on all secondary measures. Adverse consequences included lead breakage in 4 patients, infection (1), transient anxiety (2), dizziness (1), poor balance (1) and worsening of stuttering (1). Conclusions This case series provides further support that antero-medial GPi DBS is an effective and well tolerated treatment for a subgroup of severe TS, with benefits sustained up to 4 years. PMID:25136825

Sachdev, Perminder S.; Mohan, Adith; Cannon, Elisabeth; Crawford, John D.; Silberstein, Paul; Cook, Raymond; Coyne, Terrence; Silburn, Peter A.

2014-01-01

311

Conducting Polymers in Neural Stimulation Applications  

Microsoft Academic Search

\\u000a With advances in neural prostheses, the demand for high-resolution and site-specific stimulation is driving microelectrode\\u000a research to develop electrodes that are much smaller in area and longer in lifetime. For such arrays, the choice of electrode\\u000a material has become increasingly important. Currently, most neural stimulation devices use platinum, iridium oxide, or titanium\\u000a nitride electrodes. Although those metal electrodes have low

David D. Zhou; X. Tracy Cui; Amy Hines; Robert J. Greenberg

312

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. PMID:21734868

Wilson, Charles J.; Beverlin, Bryce; Netoff, Theoden

2011-01-01

313

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

314

Neural targets for relieving parkinsonian rigidity and bradykinesia with pallidal deep brain stimulation  

PubMed Central

Clinical evidence has suggested that subtle changes in deep brain stimulation (DBS) settings can have differential effects on bradykinesia and rigidity in patients with Parkinson's disease. In this study, we first investigated the degree of improvement in bradykinesia and rigidity during targeted globus pallidus DBS in three 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated rhesus macaques. Behavioral outcomes of DBS were then coupled with detailed, subject-specific computational models of neurons in the globus pallidus internus (GPi), globus pallidus externus (GPe), and internal capsule (IC) to determine which neuronal pathways when modulated with high-frequency electrical stimulation best correlate with improvement in motor symptoms. The modeling results support the hypothesis that multiple neuronal pathways can underlie the therapeutic effect of DBS on parkinsonian bradykinesia and rigidity. Across all three subjects, improvements in rigidity correlated most strongly with spread of neuronal activation into IC, driving a small percentage of fibers within this tract (<10% on average). The most robust effect on bradykinesia resulted from stimulating a combination of sensorimotor axonal projections within the GP, specifically at the site of the medial medullary lamina. Thus the beneficial effects of pallidal DBS for parkinsonian symptoms may occur from multiple targets within and near the target nucleus. PMID:22514292

Zhang, Jianyu; Ghosh, Debabrata; McIntyre, Cameron C.; Vitek, Jerrold L.

2012-01-01

315

Design of electrical stimulation bioreactors for cardiac tissue engineering.  

PubMed

Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. Carbon electrodes were found in past studies to have the best current injection characteristics. The goal of this study was to develop rational experimental design principles for the electrodes and stimulation regime, in particular electrode configuration, electrode ageing, and stimulation amplitude. Carbon rod electrodes were compared via electrochemical impedance spectroscopy (EIS) and we identified a safety range of 0 to 8 V/cm by comparing excitation thresholds and maximum capture rates for neonatal rat cardiomyocytes cultured with electrical stimulation. We conclude with recommendations for studies involving carbon electrodes for cardiac tissue engineering. PMID:19163486

Tandon, N; Marsano, A; Cannizzaro, C; Voldman, J; Vunjak-Novakovic, G

2008-01-01

316

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

2014-01-01

317

Deep brain stimulation and dantrolene for secondary dystonia in x-linked adrenoleukodystrophy.  

PubMed

Deep brain stimulation (DBS) has been used to treat secondary dystonias caused by inborn errors of metabolism with varying degrees of effectiveness. Here we report for the first time the application of DBS as treatment for secondary dystonia in a 22-year-old male with X-linked adrenoleukodystrophy (X-ALD). The disease manifested at age 6 with ADHD, tics, and dystonic gait, and deteriorated to loss of ambulation by age 11, and speech difficulties, seizures, and characteristic adrenal insufficiency by age 16. DBS in the globus pallidus internus was commenced at age 18. However, after 25 months, no improvement in dystonia was observed (Burke-Fahn-Marsden (BFM) scores of 65.5 and 62 and disability scores of 28 and 26, pre- and post-DBS, respectively) and the DBS device was removed. Treatment with dantrolene reduced skeletal muscle tone and improved movement (Global Dystonia Rating Scores from 5 to 1 and BFM score 42). Therefore, we conclude that DBS was a safe but ineffective intervention in our case with long-standing dystonia, whereas treatment of spasticity with dantrolene did improve the movement disorder in this young man with X-ALD. PMID:24718842

van Karnebeek, Clara; Horvath, Gabriella; Murphy, Tyler; Purtzki, Jacqueline; Bowden, Kristin; Sirrs, Sandra; Honey, Christopher R; Stockler, Sylvia

2015-01-01

318

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. PMID:25033198

Sommansson, Anna; Wan Saudi, Wan Salman; Nylander, Olof; Sjöblom, Markus

2014-01-01

319

Behavioral and Neurobiological Effects of Deep Brain Stimulation in a Mouse Model of High Anxiety- and Depression-Like Behavior  

PubMed Central

Increasing evidence suggests that high-frequency deep brain stimulation of the nucleus accumbens (NAcb-DBS) may represent a novel therapeutic strategy for individuals suffering from treatment-resistant depression, although the underlying mechanisms of action remain largely unknown. In this study, using a unique mouse model of enhanced depression- and anxiety-like behavior (HAB), we investigated behavioral and neurobiological effects of NAcb-DBS. HAB mice either underwent chronic treatment with one of three different selective serotonin reuptake inhibitors (SSRIs) or received NAcb-DBS for 1?h per day for 7 consecutive days. Animals were tested in established paradigms revealing depression- and anxiety-related behaviors. The enhanced depression-like behavior of HAB mice was not influenced by chronic SSRI treatment. In contrast, repeated, but not single, NAcb-DBS induced robust antidepressant and anxiolytic responses in HAB animals, while these behaviors remained unaffected in normal depression/anxiety animals (NAB), suggesting a preferential effect of NAcb-DBS on pathophysiologically deranged systems. NAcb-DBS caused a modulation of challenge-induced activity in various stress- and depression-related brain regions, including an increase in c-Fos expression in the dentate gyrus of the hippocampus and enhanced hippocampal neurogenesis in HABs. Taken together, these findings show that the normalization of the pathophysiologically enhanced, SSRI-insensitive depression-like behavior by repeated NAcb-DBS was associated with the reversal of reported aberrant brain activity and impaired adult neurogenesis in HAB mice, indicating that NAcb-DBS affects neuronal activity as well as plasticity in a defined, mood-associated network. Thus, HAB mice may represent a clinically relevant model for elucidating the neurobiological correlates of NAcb-DBS. PMID:23325324

Schmuckermair, Claudia; Gaburro, Stefano; Sah, Anupam; Landgraf, Rainer; Sartori, Simone B; Singewald, Nicolas

2013-01-01

320

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. PMID:24903550

2014-01-01

321

Greater improvement in quality of life following unilateral deep brain stimulation surgery in the globus pallidus as compared to the subthalamic nucleus  

Microsoft Academic Search

While deep brain stimulation (DBS) surgery is a well-accepted treatment for Parkinson disease (PD) that improves overall quality\\u000a of life (QoL), its effects across different domains of QoL are unclear. The study reported here directly compared the effects\\u000a of unilateral DBS in subthalamic nucleus (STN) or globus pallidus (GPi) on QoL in 42 non-demented patients with medication-refractory\\u000a PD. Patients were

Laura B. Zahodne; Michael S. Okun; Kelly D. Foote; Hubert H. Fernandez; Ramon L. Rodriguez; Samuel S. Wu; Lindsey Kirsch-Darrow; Charles E. Jacobson; Christian Rosado; Dawn Bowers

2009-01-01

322

Mechanisms of deep brain stimulation for obsessive compulsive disorder: effects upon cells and circuits  

PubMed Central

Deep brain stimulation (DBS) has emerged as a safe, effective, and reversible treatment for a number of movement disorders. This has prompted investigation of its use for other applications including psychiatric disorders. In recent years, DBS has been introduced for the treatment of obsessive compulsive disorder (OCD), which is characterized by recurrent unwanted thoughts or ideas (obsessions) and repetitive behaviors or mental acts performed in order to relieve these obsessions (compulsions). Abnormal activity in cortico-striato-thalamo-cortical (CSTC) circuits including the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), ventral striatum, and mediodorsal (MD) thalamus has been implicated in OCD. To this end a number of DBS targets including the anterior limb of the internal capsule (ALIC), ventral capsule/ventral striatum (VC/VS), ventral caudate nucleus, subthalamic nucleus (STN), and nucleus accumbens (NAc) have been investigated for the treatment of OCD. Despite its efficacy and widespread use in movement disorders, the mechanism of DBS is not fully understood, especially as it relates to psychiatric disorders. While initially thought to create a functional lesion akin to ablative procedures, it is increasingly clear that DBS may induce clinical benefit through activation of axonal fibers spanning the CSTC circuits, alteration of oscillatory activity within this network, and/or release of critical neurotransmitters. In this article we review how the use of DBS for OCD informs our understanding of both the mechanisms of DBS and the circuitry of OCD. We review the literature on DBS for OCD and discuss potential mechanisms of action at the neuronal level as well as the broader circuit level. PMID:22712007

Bourne, Sarah K.; Eckhardt, Christine A.; Sheth, Sameer A.; Eskandar, Emad N.

2012-01-01

323

[Brain stimulation therapies for treatment-resistant depression].  

PubMed

Treatment-resistant depression (TRD) is a major public health problem, affecting patients, their close relatives, and the society as a whole. Despite recent developments in psychopharmacotherapy, more than 50% of depressed patients fail to reach complete remission even when adequately treated. Neurostimulation therapies are an open field in research for the treatment of TRD, involving the delivery of physical interventions either through electric current or a magnetic field to target selective or generalized brain regions. In this paper we review evidences for four brain-stimulation therapies, i.e. electroconvulsive therapy (ECT), repetitive transcranial magnetic stimulation (rTMS), vagus nerve stimulation (VNS) and deep brain stimulation (DBS), and we enlighten several new approaches regarding ECT, rTMS and epidural cortical stimulation (EpCS). ECT is the form of neurostimulation with the most extensive evidence, rTMS and VNS have a much smaller evidence base. There is emerging evidence that DBS is effective for otherwise TRD, but this is still an investigational approach. Other approaches are anecdotal reports. ECT and rTMS can be considered as a first-line treatment under specific circumstances. Evidence supporting VNS is less consistent and DBS remains an investigational treatment. Other techniques are promising, but double-blind studies are warranted to evaluate these new approaches to TRD. PMID:23752800

Vitalucci, Alberto; Coppola, Isabella; Mirra, Marta; Maina, Giuseppe; Bogetto, Filippo

2013-01-01

324

Electrode compositions  

DOEpatents

An electrode composition for use as an electrode in a non-aqueous battery system. The electrode composition contains an electrically active powder in a solid polymer and, as a dispersant, a C.sub.8 -C.sub.15 alkyl capped oligomer of a hexanoic acid that is electrochemically inert at 2.5-4.5 volts.

Block, Jacob (Rockville, MD); Fan, Xiyun (Orange, TX)

1998-01-01

325

Cerebellar Ataxia from Multiple Potential Causes: Hypothyroidism, Hashimoto's Thyroiditis, Thalamic Stimulation, and Essential Tremor  

PubMed Central

Background Both hypothyroidism and Hashimoto's thyroiditis (HT) can rarely be associated with cerebellar ataxia. Severe essential tremor (ET) as well as bilateral thalamic deep brain stimulation (DBS) may lead to subtle cerebellar signs. Case Report We report a 74-year-old male with hypothyroidism and a 20-year history of ET who developed cerebellar ataxia after bilateral thalamic DBS. Extensive workup revealed elevated thyroid stimulating hormone and thyroperoxidase antibody titers confirming the diagnosis of HT. Discussion Our case demonstrates multiple possible causes of cerebellar ataxia in a patient, including hypothyroidism, HT, chronic ET, and bilateral thalamic DBS. Counseling of patients may be appropriate when multiple risk factors for cerebellar ataxia coexist in one individual. PMID:23439792

Shneyder, Natalya; Lyons, Mark K.; Driver-dunckley, Erika; Evidente, Virgilio Gerald H.

2012-01-01

326

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. PMID:24834035

Mantione, Mariska; Figee, Martijn; Denys, Damiaan

2014-01-01

327

Experimental results supporting the determination of service quality objectives for DBS systems  

NASA Technical Reports Server (NTRS)

A summary of the results of a joint United States and Canadian program on subjective measurements of the picture degradation caused by noise and interference on an NTSC encoded color television signal is given in this paper. The effects of system noise, cochannel and adjacent channel interference, and both single entry and aggregate as well as a combination of these types of interference were subjectively evaluated by expert and nonexpert viewers under reference conditions. These results were used to develop the rationale used at RARC '83 to establish the service quality objective for planning the DBS service for the American continents.

Chouinard, G.; Whyte, W. A., Jr.; Goldberg, A. A.; Jones, B. L.

1985-01-01

328

21 CFR 882.5810 - External functional neuromuscular stimulator.  

Code of Federal Regulations, 2011 CFR

...functional neuromuscular stimulator is an electrical stimulator that uses external electrodes for stimulating muscles in the leg and ankle of partially paralyzed patients (e.g., after stroke) to provide flexion of the foot and thus improve the patient's...

2011-04-01

329

21 CFR 882.5820 - Implanted cerebellar stimulator.  

Code of Federal Regulations, 2010 CFR

...cerebellar stimulator is a device used to stimulate electrically a patient's cerebellar cortex for the treatment of intractable epilepsy, spasticity, and some movement disorders. The stimulator consists of an implanted receiver with electrodes that are...

2010-04-01

330

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. PMID:19164104

McCairn, Kevin W.; Turner, Robert S.

2009-01-01

331

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

332

Working Electrodes  

NASA Astrophysics Data System (ADS)

In electrochemistry an electrode is an electronic conductor in contact with an ionic conductor. The electronic conductor can be a metal, or a semiconductor, or a mixed electronic and ionic conductor. The ionic conductor is usually an electrolyte solution; however, solid electrolytes and ionic melts can be used as well. The term "electrode" is also used in a technical sense, meaning the electronic conductor only. If not specified otherwise, this meaning of the term "electrode" is the subject of the present chapter. In the simplest case the electrode is a metallic conductor immersed in an electrolyte solution. At the surface of the electrode, dissolved electroactive ions change their charges by exchanging one or more electrons with the conductor. In this electrochemical reaction both the reduced and oxidized ions remain in solution, while the conductor is chemically inert and serves only as a source and sink of electrons. The technical term "electrode" usually also includes all mechanical parts supporting the conductor (e.g., a rotating disk electrode or a static mercury drop electrode). Furthermore, it includes all chemical and physical modifications of the conductor, or its surface (e.g., a mercury film electrode, an enzyme electrode, and a carbon paste electrode). However, this term does not cover the electrolyte solution and the ionic part of a double layer at the electrode/solution interface. Ion-selective electrodes, which are used in potentiometry, will not be considered in this chapter. Theoretical and practical aspects of electrodes are covered in various books and reviews [1-9].

Komorsky-Lovri?, Šebojka

333

Demultiplexer circuit for neural stimulation  

DOEpatents

A demultiplexer circuit is disclosed which can be used with a conventional neural stimulator to extend the number of electrodes which can be activated. The demultiplexer circuit, which is formed on a semiconductor substrate containing a power supply that provides all the dc electrical power for operation of the circuit, includes digital latches that receive and store addressing information from the neural stimulator one bit at a time. This addressing information is used to program one or more 1:2.sup.N demultiplexers in the demultiplexer circuit which then route neural stimulation signals from the neural stimulator to an electrode array which is connected to the outputs of the 1:2.sup.N demultiplexer. The demultiplexer circuit allows the number of individual electrodes in the electrode array to be increased by a factor of 2.sup.N with N generally being in a range of 2-4.

Wessendorf, Kurt O; Okandan, Murat; Pearson, Sean

2012-10-09

334

Recording evoked potentials during deep brain stimulation: development and validation of instrumentation to suppress the stimulus artefact  

PubMed Central

Deep brain stimulation (DBS) is an effective treatment for movement disorders, but the selection of stimulus parameters is a clinical burden and often yields sub-optimal outcomes for patients. Measurement of electrically evoked compound action potentials (ECAPs) during DBS could offer insight into the type and spatial extent of neural element activation and provide a potential feedback signal for the rational selection of stimulus parameters and closed-loop DBS. However, recording ECAPs presents a significant technical challenge due to the large stimulus artefact, which can saturate recording amplifiers and distort short latency ECAP signals. We developed DBS-ECAP recording instrumentation combining commercial amplifiers and circuit elements in a serial configuration to reduce the stimulus artefact and enable high fidelity recording. We used an electrical circuit equivalent model of the instrumentation to understand better the sources of the stimulus artefact and the mechanisms of artefact reduction by the circuit elements. In vitro testing validated the capability of the instrumentation to suppress the stimulus artefact and increase gain by a factor of 1,000 to 5,000 compared to a conventional biopotential amplifier. The distortion of mock ECAP (mECAP) signals was measured across stimulation parameters, and the instrumentation enabled high fidelity recording of mECAPs with latencies of only 0.5 ms for DBS pulse widths of 50 to 100 ?s/phase. Subsequently, the instrumentation was used to record in vivo ECAPs, without contamination by the stimulus artefact, during thalamic DBS in an anesthetized cat. The characteristics of the physiological ECAP were dependent on stimulation parameters. The novel instrumentation enables high fidelity ECAP recording and advances the potential use of the ECAP as a feedback signal for the tuning of DBS parameters. PMID:22510375

Kent, A R; Grill, W M

2012-01-01

335

Liquid electrode  

DOEpatents

A dropping electrolyte electrode for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions.

Ekechukwu, Amy A. (Augusta, GA)

1994-01-01

336

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. PMID:24904312

Furmaga, Havan; Park, Hyun-Joo; Cooperrider, Jessica; Baker, Kenneth B.; Johnson, Matthew; Gale, John T.; Machado, Andre G.

2014-01-01

337

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

Microsoft Academic Search

BACKGROUND: In spite of advances in psychotherapy and pharmacotherapy, there are still a significant number of patients with depression and obsessive-compulsive disorder that are not aided by either intervention. Although still in the experimental stage, deep brain stimulation (DBS) offers many advantages over other physically-invasive procedures as a treatment for these psychiatric disorders. The purpose of this study is to

Shaheen E Lakhan; Enoch Callaway

2010-01-01

338

Towards a neurophysiological foundation for cognitive neuromodulation through deep brain stimulation  

Microsoft Academic Search

It may soon be possible to adapt the use of deep brain stimulation (DBS) technologies developed to treat movement disorders to improve the general cognitive function of brain-injured patients. We outline neurophysiological foundations for novel neuromodulation strategies to address these goals. Emphasis is placed on developing a rationale for targeting the intralaminar and related nuclei of the human thalamus for

Nicholas D. Schiff; Keith P. Purpura

2002-01-01

339

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. PMID:22295068

Moum, Sarah J.; Price, Catherine C.; Limotai, Natlada; Oyama, Genko; Ward, Herbert; Jacobson, Charles; Foote, Kelly D.; Okun, Michael S.

2012-01-01

340

Axonal and synaptic failure suppress the transfer of firing rate oscillations, synchrony and information during high frequency deep brain stimulation  

PubMed Central

High frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a widely used treatment for Parkinson's disease, but its effects on neural activity in basal ganglia circuits are not fully understood. DBS increases the excitation of STN efferents yet decouples STN spiking patterns from the spiking patterns of STN synaptic targets. We propose that this apparent paradox is resolved by recent studies showing an increased rate of axonal and synaptic failures in STN projections during DBS. To investigate this hypothesis, we combine in vitro and in vivo recordings to derive a computational model of axonal and synaptic failure during DBS. Our model shows that these failures induce a short term depression that suppresses the synaptic transfer of firing rate oscillations, synchrony and rate-coded information from STN to its synaptic targets. In particular, our computational model reproduces the widely reported suppression of parkinsonian ? oscillations and synchrony during DBS. Our results support the idea that short term depression is a therapeutic mechanism of STN DBS that works as a functional lesion by decoupling the somatic spiking patterns of STN neurons from spiking activity in basal ganglia output nuclei. PMID:24051279

Rosenbaum, Robert; Zimnik, Andrew; Zheng, Fang; Turner, Robert S.; Alzheimer, Christian; Doiron, Brent; Rubin, Jonathan E.

2013-01-01

341

Functional regeneration of severed peripheral nerve using an implantable electrical stimulator  

Microsoft Academic Search

This paper presents functional regeneration of severed peripheral nerve using a polymer-based implantable electrical stimulator. A polyimide based conduit electrode was made by micro-fabrication and a stimulation chip was designed to generate biphasic current pulse for electrical stimulation. The stimulation chip was packaged with a battery using silicone elastomer, and integrated with the electrode. The implantable electrical stimulator was implanted

Tae Hyung Lee; Hui Pan; In Sook Kim; Soon Jung Hwang; S. J. Kim

2010-01-01

342

Subthalamic nucleus-deep brain stimulation for early motor complications in Parkinson's disease-the EARLYSTIM trial: early is not always better.  

PubMed

Subthalamic nucleus deep brain stimulation (STN-DBS) has revolutionized the management of disabling motor complications in Parkinson's disease. The EARLYSTIM trial applied this treatment to patients who had been experiencing motor complications for less than three years. STN-DBS significantly improved all primary and secondary outcome measures while best medical therapy failed to provide any improvement at the two-year follow-up time point. On face value these results strongly favor the application of STN-DBS far earlier than is currently applied, when patients are just beginning to experience problems with motor complications. Here we review the application of early DBS and the EARLYSTIM trial from the perspectives of clinical issues, health economics and study design and patient expectation of benefit. We conclude that the most relevant issue is not when to operate but on whom and that early is not always better. © 2014 International Parkinson and Movement Disorder Society. PMID:25227325

Mestre, Tiago A; Espay, Alberto J; Marras, Connie; Eckman, Mark H; Pollak, Pierre; Lang, Anthony E

2014-12-01

343

Closing the loop of deep brain stimulation  

PubMed Central

High-frequency deep brain stimulation is used to treat a wide range of brain disorders, like Parkinson's disease. The stimulated networks usually share common electrophysiological signatures, including hyperactivity and/or dysrhythmia. From a clinical perspective, HFS is expected to alleviate clinical signs without generating adverse effects. Here, we consider whether the classical open-loop HFS fulfills these criteria and outline current experimental or theoretical research on the different types of closed-loop DBS that could provide better clinical outcomes. In the first part of the review, the two routes followed by HFS-evoked axonal spikes are explored. In one direction, orthodromic spikes functionally de-afferent the stimulated nucleus from its downstream target networks. In the opposite direction, antidromic spikes prevent this nucleus from being influenced by its afferent networks. As a result, the pathological synchronized activity no longer propagates from the cortical networks to the stimulated nucleus. The overall result can be described as a reversible functional de-afferentation of the stimulated nucleus from its upstream and downstream nuclei. In the second part of the review, the latest advances in closed-loop DBS are considered. Some of the proposed approaches are based on mathematical models, which emphasize different aspects of the parkinsonian basal ganglia: excessive synchronization, abnormal firing-rate rhythms, and a deficient thalamo-cortical relay. The stimulation strategies are classified depending on the control-theory techniques on which they are based: adaptive and on-demand stimulation schemes, delayed and multi-site approaches, stimulations based on proportional and/or derivative control actions, optimal control strategies. Some of these strategies have been validated experimentally, but there is still a large reservoir of theoretical work that may point to ways of improving practical treatment. PMID:24391555

Carron, Romain; Chaillet, Antoine; Filipchuk, Anton; Pasillas-Lépine, William; Hammond, Constance

2013-01-01

344

Long-term effects of pallidal or subthalamic deep brain stimulation on quality of life in Parkinson's disease.  

PubMed

We assessed the effects of deep brain stimulation of the subthalamic nucleus (STN-DBS) or internal pallidum (GPi-DBS) on health-related quality of life (HrQoL) in patients with advanced Parkinson's disease participating in a previously reported multicenter trial. Sickness Impact Profile (SIP) questionnaires were available for analysis in a subgroup of n = 20/20 patients with GPi-DBS and n = 45/49 patients with STN-DBS at baseline, 6 and 36 months. The SIP provides a physical dimension and a psychosocial dimension sum score and 12 category scores: Alertness/Intellectual Behavior (AIB), Ambulation (A), Body Care and Movement (BCM), Communication (C), Eating (E), Emotional Behavior (EB), Home Management (HM), Mobility (M), Recreation and Pastimes (RP), Sleep and Rest (SR), Social Interaction (SI), and Work (W). Motor functioning was assessed by means of the Unified Parkinson's Disease Rating Scale and diaries. At 6 months significant improvements in off-period motor symptoms and activities of daily living were paralleled by significant reductions in the total, physical, and psychosocial SIP score in both treatment groups. At 3 years, sustained improvements were observed in the physical dimension score, BCM, E, M, RP after STN-DBS and M, SI after GPi-DBS. All other SIP subscores approached baseline values, but were still the same or better (except C) whereas motor functioning remained stable after 36 months. STN-DBS and GPi-DBS led to significant early improvements in HrQoL. Despite sustained motor improvements many of these initial benefits were lost after 3 years. This may reflect either progression of the disease or adaptive changes in the subjective perception of health-related wellbeing over time. PMID:19412954

Volkmann, Jens; Albanese, Alberto; Kulisevsky, Jaime; Tornqvist, Aana-Lena; Houeto, Jean-Luc; Pidoux, Bernard; Bonnet, Anne-Marie; Mendes, Alexandre; Benabid, Alim-Louis; Fraix, Valerie; Van Blercom, Nadege; Xie, Jing; Obeso, José; Rodriguez-Oroz, Maria Cruz; Guridi, Jurge; Schnitzler, Alfons; Timmermann, Lars; Gironell, Alexandre A; Molet, Juan; Pascual-Sedano, Benta; Rehncrona, Stig; Moro, Elena; Lang, Anthony C; Lozano, Andres M; Bentivoglio, Anna Rita; Scerrati, Massimo; Contarino, Maria Fiorella; Romito, Luigi; Janssens, Marc; Agid, Yves

2009-06-15

345

Neurosurgical aspects of temporal deep brain stimulation for epilepsy  

Microsoft Academic Search

Deep brain stimulation (DBS), which mimics the effect of ablative surgery in movement disorders, is considered by analogy\\u000a as potentially useful in the epileptic temporal lobe as an alternative to resection. It could be applied to patients in whom\\u000a resective surgery is less beneficial, e.g. cases without memory impairment or with bilateral hippocampal involvement. In patients\\u000a who undergo invasive presurgical

D. Van Roost; P. Boon; K. Vonck; J. Caemaert

346

Electrical stimulation for propelling endoscopes  

Microsoft Academic Search

Background: Methods are needed for propulsion of endoscopes and wireless video capsules along the small intestine. This work aims to test the hypothesis that electrical stimulation could propel an endoscope by stimulating muscular contraction. Methods: Prototype acrylic ovoid-shaped devices were constructed with 2 stainless steel electrodes mounted on the tapered section. Five devices 15 to 23 mm diameter with a

C. Alexander Mosse; Timothy N. Mills; Mark N. Appleyard; Srinathan S. Kadirkamanathan; C. Paul Swain

2001-01-01

347

Beta-band frequency peaks inside the subthalamic nucleus as a biomarker for motor improvement after deep brain stimulation in Parkinson's disease.  

PubMed

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) remains an empirical, yet highly effective, surgical treatment for advanced Parkinson's disease (PD). DBS outcome depends on accurate stimulation of the STN sensorimotor area which is a trial-and-error procedure taking place during and after surgery. Pathologically enhanced beta-band (13-35 Hz) oscillatory activity across the cortico-basal ganglia pathways is a prominent neurophysiological phenomenon associated with PD. We hypothesized that weighing together beta-band frequency peaks from simultaneous microelectrode recordings in "off-state" PD patients could map the individual neuroanatomical variability and serve as a biomarker for the location of the STN sensorimotor neurons. We validated our hypothesis with 9 and 11 patients that, respectively, responded well and poorly to bilateral DBS, after at least two years of follow up. We categorized "good" and "poor" DBS responders based on their clinical assessment alongside a > 40% and <30% change, respectively, in "off" unified PD rating scale motor scores. Good (poor) DBS responders had, in average, 1 mm (3.5 mm) vertical distance between the maximum beta-peak weighted across the parallel microelectrodes and the center of the stimulation area. The distances were statistically different in the two groups ( p = 0.0025 ). Our biomarker could provide personalized intra- and postoperative support in stimulating the STN sensorimotor area associated with optimal long-term clinical benefits. PMID:25095273

Michmizos, Konstantinos P; Frangou, Polytimi; Stathis, Pantelis; Sakas, Damianos; Nikita, Konstantina S

2015-01-01

348

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 stereotactic ablation or DBS in carefully selected patients. Benefit in such cases appears not to be confined to obsessions and compulsions, but includes changes in affective state. Caution is imperative, and key issues in long-term management of psychiatric neurosurgery patients deserve focused attention. DBS and contemporary ablation also present different patterns of potential benefits and burdens. Translational research to elucidate how targeting specific nodes in putative OCD circuitry might lead to therapeutic gains is accelerating in tandem with clinical use. PMID:19759530

Greenberg, Benjamin D; Rauch, Scott L; Haber, Suzanne N

2010-01-01

349

Subthalamic Nucleus Deep Brain Stimulation Impacts Language in Early Parkinson's Disease  

PubMed Central

Although deep brain stimulation (DBS) of the basal ganglia improves motor outcomes in Parkinson's disease (PD), its effects on cognition, including language, remain unclear. This study examined the impact of subthalamic nucleus (STN) DBS on two fundamental capacities of language, grammatical and lexical functions. These functions were tested with the production of regular and irregular past-tenses, which contrast aspects of grammatical (regulars) and lexical (irregulars) processing while controlling for multiple potentially confounding factors. Aspects of the motor system were tested by contrasting the naming of manipulated (motor) and non-manipulated (non-motor) objects. Performance was compared between healthy controls and early-stage PD patients treated with either DBS/medications or medications alone. Patients were assessed on and off treatment, with controls following a parallel testing schedule. STN-DBS improved naming of manipulated (motor) but not non-manipulated (non-motor) objects, as compared to both controls and patients with just medications, who did not differ from each other across assessment sessions. In contrast, STN-DBS led to worse performance at regulars (grammar) but not irregulars (lexicon), as compared to the other two subject groups, who again did not differ. The results suggest that STN-DBS negatively impacts language in early PD, but may be specific in depressing aspects of grammatical and not lexical processing. The finding that STN-DBS affects both motor and grammar (but not lexical) functions strengthens the view that both depend on basal ganglia circuitry, although the mechanisms for its differential impact on the two (improved motor, impaired grammar) remain to be elucidated. PMID:22880117

Phillips, Lara; Litcofsky, Kaitlyn A.; Pelster, Michael; Gelfand, Matthew

2012-01-01

350

Cognitive predictors of cognitive change following bilateral subthalamic nucleus deep brain stimulation in Parkinson's disease.  

PubMed

The beneficial effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN) for the motor symptoms in advanced Parkinson's disease (PD) are well established. Early in PD, mild cognitive impairment is present in a proportion of patients. Hence, it can also be present in PD patients considered for DBS. The potential impact of even a modest decline post-surgically is a concern because it could result in impaired cognitive function. Therefore, attempts to determine which pre-operative cognitive measures predict post-operative cognitive change warrant further attention. We report our findings in a cohort of 30 routinely operated non-demented patients who underwent detailed neuropsychological assessments on average 7.1 months before and 9.4 months after STN DBS. We report the individual and group differences pre- and post-DBS. Stepwise regression analysis was used to analyse the best cognitive predictors of post-operative cognitive changes. We describe our data in relation to published normative data. Post-STN DBS, the immediate story recall component of verbal memory was the most affected cognitive function showing a significant decline in its group mean with a large effect size. The best predictors for this change were pre-surgical list learning and Full Scale Intelligence Quotient. These results suggest that non-demented patients, with even mild impairments in both general intellectual functions and list learning, may be at greater risk of decline in other aspects of verbal memory after STN DBS. Pre-existing mild executive dysfunction was not influenced post-operatively. These findings may help selection and consent for STN DBS. PMID:24231557

Yágüez, Lidia; Costello, Angela; Moriarty, John; Hulse, Natasha; Selway, Richard; Clough, Chris; Samuel, Michael; Ashkan, Keyoumars

2014-03-01

351

Deep brain stimulation for dystonia.  

PubMed

The few reported controlled studies show that bilateral stimulation of the globus pallidus interna (GPi) is a safe and effective long-term treatment for hyperkinetic disorders. However, the recently published data on deep brain stimulation (DBS) applied to different targets or patients (especially those with secondary dystonia) are mainly uncontrolled case reports, precluding a clear determination of its efficacy, and providing little guidance as to the choice of a "good" target in a "good" patient. This chapter reviews the literature on DBS in primary dystonia, paying particular attention to the risk:benefit ratio in focal and segmental dystonias (cervical dystonia, cranial dystonia) and to the predictive factors for a good outcome. The chapter also highlights recent data on the marked benefits of the technique in myoclonus dystonia (in which pallidal, as opposed to thalamic, stimulation is more effective) and in tardive dystonia-dyskinesia. Although, the decision to treat appears relatively straightforward in patients with primary dystonia, myoclonus-dystonia, and tardive dystonia who have a normal findings on magnetic resonance imaging and normal cognitive function, there are still no reliable tools to help predict the timescale of postoperative benefit. This chapter provides a comprehensive analysis of the use of the treatment in various types of secondary dystonia, with little to moderate benefit in most cases, based on single cases or small series. Beyond the reduction in the severity of dystonia, the global motor and functional outcome is difficult to determine owing to the paucity of adequate evaluation tools. Because of the large interpatient variability, different targets may be effective depending on the symptoms in each individual. PMID:24112893

Vidailhet, Marie; Jutras, Marie-France; Roze, Emmanuel; Grabli, David

2013-01-01

352

Liquid electrode  

DOEpatents

A dropping electrolyte electrode is described for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions. 2 figures.

Ekechukwu, A.A.

1994-07-05

353

fMRI of deep brain stimulation at the rat ventral posteromedial thalamus  

PubMed Central

Background Functional magnetic resonance imaging (fMRI) of deep brain stimulation (DBS) has potentials to reveal neuroanatomical connectivity of a specific brain region in vivo. Objective This study aimed to demonstrate frequency and amplitude tunings of the thalamocortical tract using DBS fMRI at the rat ventral posteromedial thalamus. Methods Blood oxygenation level dependent (BOLD) fMRI (n=12) data were acquired in rats at a high-field 11.7T MRI scanner with modulation of nine stimulus frequencies (1–40 Hz) and seven stimulus amplitudes (0.2–3.6 mA). Results BOLD response in the barrel cortex peaked at 25 Hz. The response increased with stimulus amplitude and reached a plateau at 1 mA. Cortical spreading depolarization (CSD) was observed occasionally after DBS that carries >10% BOLD waves spanning the entire ipsilateral cortex. Conclusion fMRI of DBS has potential to explore and validate functional connectivity in the brain, study DBS treatment effect, and investigate the spatiotemporal characteristics of the CSD. PMID:24309153

Shih, Yen-Yu I.; Yash, Tiwari V.; Rogers, Bill; Duong, Timothy Q.

2014-01-01

354

Factors Related to Outcomes of Subthalamic Deep Brain Stimulation in Parkinson's Disease  

PubMed Central

Objective Subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective treatment of choice for patients with advanced idiopathic Parkinson's disease (PD) who have motor complication with medication. The objectives of this study are to analyze long-term follow-up data of STN DBS cases and to identify the factors related to outcomes. Methods Fifty-two PD patients who underwent STN DBS were followed-up for more than 3 years. The Unified Parkinsons Disease Rating Scale (UPDRS) and other clinical profiles were assessed preoperatively and during follow-up. A linear regression model was used to analyze whether factors predict the results of STN DBS. We divided the study individuals into subgroups according to several factors and compared subgroups. Results Preoperative activity of daily living (ADL) and the magnitude of preoperative levodopa response were shown to predict the improvement in UPDRS part II without medication, and preoperative ADL and levodopa equivalent dose (LED) were shown to predict the improvement in UPDRS part II with medication. In UPDRS part III with medication, the magnitude of preoperative levodopa response was a predicting factor. Conclusion The intensity of preoperative levodopa response was a strong factor for motor outcome. And preoperative ADL and LED were strong factors for ADL improvement. More vigorous studies should be conducted to elucidate how levodopa-induced motor complications are ameliorated after STN DBS. PMID:24175026

Kim, Hae Yu; Chang, Won Seok; Kang, Dong Wan; Sohn, Young Ho; Lee, Myung Sik

2013-01-01

355

Anticoagulation management of myocardial infarction after deep brain stimulation: a comparison of two cases.  

PubMed

Deep brain stimulation (DBS) is an established treatment of various diseases, particularly used for idiopathic Parkinson's disease. Frequently, DBS patients are multimorbid and managing them may be challenging, since postoperative complications can become more likely with age. In this article, we present two cases of myocardial infarction after DBS with different therapeutic strategies. Case 1 was anticoagulated with a heparin infusion with a target partial thromboplastine time (PTT) between 50 and 60 s after the myocardial infarction and showed 3 days later, after an initial postoperative inconspicuous cranial computer tomography, an intracerebral haematoma, which was evacuated without explanting the DBS lead. Case 2 was only treated with enoxaparine 40 mg s.c. twice a day after the myocardial infarction without any further complications. Both cases benefited from the DBS with respect to the motor fluctuations, but case 1 continued to suffer from psychomotor slowdown, mild hemiparesis of the left side, visual neglect and a gaze paresis. Unfortunately, there are no established guidelines or therapy recommendations for the management of such patients. An individual therapy regime is necessary for this patient population regarding the bleeding risk, the cardial risk and the symptoms of the patient. Retrospectively, the rejection of the intravenous application of heparin in case 2 seems to be the right decision. But regarding the small number of cases, it remains still an individual therapy. Further experience will help us to develop optimal therapy strategies for this patient population. PMID:23563744

Polanski, Witold; Koy, Jan; Juratli, Tareq; Wolz, Martin; Klingelhöfer, Lisa; Fauser, Mareike; Storch, Alexander; Schackert, Gabriele; Sobottka, Stephan B

2013-09-01

356

Penfield’s Prediction: A Mechanism for Deep Brain Stimulation  

PubMed Central

Context: Despite its widespread use, the precise mechanism of action of Deep Brain Stimulation (DBS) therapy remains unknown. The modern urgency to publish more and new data can obscure previously learned lessons by the giants who have preceded us and whose shoulders we now stand upon. Wilder Penfield extensively studied the effects of artificial electrical brain stimulation and his comments on the subject are still very relevant today. In particular, he noted two very different (and seemingly opposite) effects of stimulation within the human brain. In some structures, artificial electrical stimulation has an effect, which mimics ablation, while, in other structures, it produces a stimulatory effect on that tissue. Hypothesis: The hypothesis of this paper is fourfold. First, it proposes that some neural circuits are widely synchronized with other neural circuits, while some neural circuits are unsynchronized and operate independently. Second, it proposes that artificial high-frequency electrical stimulation of a synchronized neural circuit results in an ablative effect, but artificial high-frequency electrical stimulation of an unsynchronized neural circuit results in a stimulatory effect. Third, it suggests a part of the mechanism by which large-scale physiologic synchronization of widely distributed independently processed information streams may occur. This may be the neural mechanism underlying Penfield’s “centrencephalic system,” which he emphasized so many years ago. Fourth, it outlines the specific anatomic distribution of this physiologic synchronization, which Penfield has already clearly delineated as the distribution of his centrencephalic system. Evidence: This paper draws on a brief overview of previous theory regarding the mechanism of action of DBS and on historical, as well as widely known modern clinical data regarding the observed effects of stimulation delivered to various targets within the brain. Basic science investigations, which support the hypothesis are also cited. Conclusion: This paper proposes a novel hypothesis for the mechanism of action of DBS, which was conceptually foreshadowed by Wilder Penfield decades ago. PMID:25368601

Murrow, Richard W.

2014-01-01

357

Response of Human Thalamic Neurons to High-Frequency Stimulation  

PubMed Central

Thalamic deep brain stimulation (DBS) is an effective treatment for tremor, but the mechanisms of action remain unclear. Previous studies of human thalamic neurons to noted transient rebound bursting activity followed by prolonged inhibition after cessation of high frequency extracellular stimulation, and the present study sought to identify the mechanisms underlying this response. Recordings from 13 thalamic neurons exhibiting low threshold spike (LTS) bursting to brief periods of extracellular stimulation were made during surgeries to implant DBS leads in 6 subjects with Parkinson's disease. The response immediately after cessation of stimulation included a short epoch of burst activity, followed by a prolonged period of silence before a return to LTS bursting. A computational model of a population of thalamocortical relay neurons and presynaptic axons terminating on the neurons was used to identify cellular mechanisms of the observed responses. The model included the actions of neuromodulators through inhibition of a non-pertussis toxin sensitive K+ current (IKL), activation of a pertussis toxin sensitive K+ current (IKG), and a shift in the activation curve of the hyperpolarization-activated cation current (Ih). The model replicated well the measured responses, and the prolonged inhibition was associated most strongly with changes in IKG while modulation of IKL or Ih had minimal effects on post-stimulus inhibition suggesting that neuromodulators released in response to high frequency stimulation are responsible for mediating the post-stimulation bursting and subsequent long duration silence of thalamic neurons. The modeling also indicated that the axons of the model neurons responded robustly to suprathreshold stimulation despite the inhibitory effects on the soma. The findings suggest that during DBS the axons of thalamocortical neurons are activated while the cell bodies are inhibited thus blocking the transmission of pathological signals through the network and replacing them with high frequency regular firing. PMID:24804767

Birdno, Merrill J.; Tang, Wei; Dostrovsky, Jonathan O.; Hutchison, William D.; Grill, Warren M.

2014-01-01

358

Multicenter study on deep brain stimulation in Parkinson's disease: an independent assessment of reported adverse events at 4 years.  

PubMed

Ongoing adverse events (AEs) at 4-years postsurgery in 69 patients with advanced Parkinson's disease (PD) who received deep brain stimulation (DBS) of the subthalamic nucleus (STN) (n = 49) or the internal globus pallidus (GPi) (n = 20), in the framework of a subset of eight centers of a multicenter study, were analyzed by an independent ad hoc committee. At baseline, the patients' age, sex, disease duration, and clinical condition were virtually identical, as was the duration of follow-up. There were 64 AEs reported in 53% of STN DBS patients and eight AEs reported in 35% of GPi DBS patients. Most of the AEs were not deemed severe and were reported to be present "both with and without stimulation." The majority of the AEs affected patients' cognitive, psychiatric and behavioral status, as well as speech, gait, and balance, and most of these AEs occurred in STN DBS patients. When comparing patients who exhibited AEs with those who did not, it was found that in the STN DBS group, the patients with AEs had a longer disease duration, as well as more gait disorders and psychiatric disturbances at baseline. PMID:18067188

Hariz, Marwan I; Rehncrona, Stig; Quinn, Niall P; Speelman, Johannes D; Wensing, Carin

2008-02-15

359

Subdural Electrodes  

PubMed Central

Subdural electrodes are frequently used to aid in the neurophysiological assessment of patients with intractable seizures. We review the indications for these, their uses for localizing epileptogenic regions and for localizing cortical regions supporting movement, sensation, and language. PMID:20573543

Lesser, Ronald P.; Crone, Nathan E.; Webber, W.R.S.

2010-01-01

360

Working Electrodes  

Microsoft Academic Search

\\u000a In electrochemistry an electrode is an electronic conductor in contact with an ionic conductor. The electronic conductor can\\u000a be a metal, or a semiconductor, or a mixed electronic and ionic conductor. The ionic conductor is usually an electrolyte solution;\\u000a however, solid electrolytes and ionic melts can be used as well. The term “electrode” is also used in a technical sense,

Šebojka Komorsky-Lovri?

361

Pattern electrical stimulation of the human retina  

Microsoft Academic Search

Experiments were conducted to study if electrical stimulation of the retinal surface can elicit visual sensation in individuals blind from end-stage retinitis pigmentosa (RP) or age-related macular degeneration (AMD). Under local anesthesia, different stimulating electrodes were inserted through the eyewall and positioned over the surface of the retina. Subjects' psychophysical responses to electrical stimulation were recorded. Subjects perceived simple forms

Mark S. Humayun; De Juan E; James D. Weiland; Gislin Dagnelie; Steve Katona; Robert Greenberg; Satoshi Suzuki; Maumenee Bldg

1999-01-01

362

Different Clinical Electrodes Achieve Similar Electrical Nerve Conduction Block  

PubMed Central

Objective Evaluate the suitability of four electrodes previously used in clinical experiments for peripheral nerve electrical block applications. Approach We evaluated peripheral nerve electrical block using three such clinical nerve cuff electrodes (the Huntington helix, the Case self-sizing spiral and the Flat Interface Nerve Electrode) and one clinical intramuscular electrode (the Memberg electrode) in five cats. Amplitude thresholds for block using 12 or 25 kHz voltage-controlled stimulation, onset response, and stimulation thresholds before and after block testing were determined. Main results Complete nerve block was achieved reliably and the onset response to blocking stimulation was similar for all electrodes. Amplitude thresholds for block were lowest for the Case Spiral electrode (4 ± 1 Vpp) and lower for the nerve cuff electrodes (7 ± 3 Vpp) than for the intramuscular electrode (26 ± 10 Vpp). A minor elevation in stimulation threshold and reduction in stimulus-evoked urethral pressure was observed during testing, but the effect was temporary and did not vary between electrodes. Significance Multiple clinical electrodes appear suitable for neuroprostheses using peripheral nerve electrical block. The freedom to choose electrodes based on secondary criteria such as ease of implantation or cost should ease translation of electrical nerve block to clinical practice. PMID:23986089

Boger, Adam; Bhadra, Narendra; Gustafson, Kenneth J.

2015-01-01

363

Method of making biocompatible electrodes  

DOEpatents

A process of improving the sensing function of biocompatible electrodes and the product so made are disclosed. The process is designed to alter the surfaces of the electrodes at their tips to provide increased surface area and therefore decreased contact resistance at the electrode-tissue interface for increased sensitivity and essentially includes rendering the tips atomically clean by exposing them to bombardment by ions of an inert gas, depositing an adhesion layer on the cleaned tips, forming a hillocked layer on the adhesion layer by increasing the temperature of the tips, and applying a biocompatible coating on the hillocked layer. The resultant biocompatible electrode is characterized by improved sensitivity, minimum voltage requirement for organ stimulation and a longer battery life for the device in which it is employed.

Wollam, John S. (Acton, MA)

1992-01-01

364

Frequency-dependent functional neuromodulatory effects on the motor network by ventral lateral thalamic deep brain stimulation in swine.  

PubMed

Thalamic deep brain stimulation (DBS) is an FDA-approved neurosurgical treatment for medication-refractory essential tremor. Its therapeutic benefit is highly dependent upon stimulation frequency and voltage parameters. We investigated these stimulation parameter-dependent effects on neural network activation by performing functional magnetic resonance imaging (fMRI) during DBS of the ventral lateral (VL) thalamus and comparing the blood oxygenation level-dependent (BOLD) signals induced by multiple stimulation parameter combinations in a within-subject study of swine. Low (10Hz) and high (130Hz) frequency stimulation was applied at 3, 5, and 7V in the VL thalamus of normal swine (n=5). We found that stimulation frequency and voltage combinations differentially modulated the brain network activity in the sensorimotor cortex, the basal ganglia, and the cerebellum in a parameter-dependent manner. Notably, in the motor cortex, high frequency stimulation generated a negative BOLD response, while low frequency stimulation increased the positive BOLD response. These frequency-dependent differential effects suggest that the VL thalamus is an exemplary target for investigating functional network connectivity associated with therapeutic DBS. PMID:25451479

Paek, Seungleal B; Min, Hoon-Ki; Kim, Inyong; Knight, Emily J; Baek, James J; Bieber, Allan J; Lee, Kendall H; Chang, Su-Youne

2015-01-15

365

Intensive Voice Treatment (LSVT[R]LOUD) for Parkinson's Disease Following Deep Brain Stimulation of the Subthalamic Nucleus  

ERIC Educational Resources Information Center

Purpose: Intensive voice therapy (LSVT[R]LOUD) can effectively manage voice and speech symptoms associated with idiopathic Parkinson disease (PD). This small-group study evaluated voice and speech in individuals with and without deep brain stimulation of the subthalamic nucleus (STN-DBS) before and after LSVT LOUD, to determine whether outcomes…

Spielman, Jennifer; Mahler, Leslie; Halpern, Angela; Gilley, Phllip; Klepitskaya, Olga; Ramig, Lorraine

2011-01-01

366

Effects of Stimulation of the Subthalamic Nucleus on Naming and Reading Nouns and Verbs in Parkinson's Disease  

ERIC Educational Resources Information Center

An impairment for verbs has been described in patients with Parkinson's disease (PD), suggesting that a disruption of frontal-subcortical circuits may result in dysfunction of the neural systems involved in action-verb processing. A previous study suggested that deep brain stimulation (DBS) of the subthalamic nucleus (STN) during verb generation…

Silveri, Maria Caterina; Ciccarelli, Nicoletta; Baldonero, Eleonora; Piano, Carla; Zinno, Massimiliano; Soleti, Francesco; Bentivoglio, Anna Rita; Albanese, Alberto; Daniele, Antonio

2012-01-01

367

Subthalamic deep brain stimulation in Parkinson?s disease has no significant effect on perceptual timing in the hundreds of milliseconds range  

PubMed Central

Bilateral, high-frequency stimulation of the basal ganglia (STN-DBS) is in widespread use for the treatment of the motor symptoms of Parkinson?s disease (PD). We present here the first psychophysical investigation of the effect of STN-DBS upon perceptual timing in the hundreds of milliseconds range, with both duration-based (absolute) and beat-based (relative) tasks; 13 patients with PD were assessed with their STN-DBS ‘on’, ‘off’, and then ‘on’ again. Paired parametric analyses revealed no statistically significant differences for any task according to DBS status. We demonstrate, from the examination of confidence intervals, that any functionally relevant effect of STN-DBS on relative perceptual timing is statistically unlikely. For absolute, duration-based timing, we demonstrate that the activation of STN-DBS may either worsen performance or have no effect, but that it is unlikely to lead to significant improvement. Although these results are negative they have important implications for our understanding of perceptual timing and its relationship to motor functions within the timing network of the brain. They imply that the mechanisms involved in the perceptual processing of temporal information are likely to be functionally independent from those that underpin movement. Further, they suggest that the connections between STN and the subtantia nigra and globus pallidus are unlikely to be critical to beat-based perceptual timing. PMID:24613477

Cope, Thomas E.; Grube, Manon; Mandal, Arnab; Cooper, Freya E.; Brechany, Una; Burn, David J.; Griffiths, Timothy D.

2014-01-01

368

Cermet electrode  

DOEpatents

Disclosed is a cermet electrode consisting of metal particles of nickel, cobalt, iron, or alloys or mixtures thereof immobilized by zirconia stabilized in cubic form which contains discrete deposits of about 0.1 to about 5% by weight of praseodymium, dysprosium, terbium, or a mixture thereof. The solid oxide electrode can be made by covering a substrate with particles of nickel, cobalt, iron, or mixtures thereof, growing a stabilized zirconia solid oxide skeleton around the particles thereby immobilizing them, contacting the skeleton with a compound of praseodymium, dysprosium, terbium, or a mixture thereof, and heating the skeleton to a temperature of at least 500.degree. C. The electrode can also be made by preparing a slurry of nickel, cobalt, iron, or mixture and a compound of praseodymium, dysprosium, terbium, or a mixture thereof, depositing the slurry on a substrate, heating the slurry to dryness, and growing a stabilized zirconia skeleton around the metal particles.

Maskalick, Nicholas J. (Pittsburgh, PA)

1988-08-30

369

Photoelectrochemical electrodes  

NASA Technical Reports Server (NTRS)

The surface of a moderate band gap semiconductor such as p-type molybdenum sulfide is modified to contain an adherent film of charge mediating ionene polymer containing an electroactive unit such as bipyridimium. Electron transport between the electrode and the mediator film is favorable and photocorrosion and recombination processes are suppressed. Incorporation of particles of catalyst such as platinum within the film provides a reduction in overvoltage. The polymer film is readily deposited on the electrode surface and can be rendered stable by ionic or addition crosslinking. Catalyst can be predispersed in the polymer film or a salt can be impregnated into the film and reduced therein.

Williams, R. M.; Rembaum, A. (inventors)

1983-01-01

370

Advanced therapy learning algorithm for spinal cord stimulation  

E-print Network

Spinal Cord Stimulation (SCS) is a technique used to treat chronic pain and has been shown to be an effective method of treatment, both financially and socioeconomically. Stimulating electrodes are surgically implanted ...

Gaudreau Balderrama, Amanda Dawn

2010-01-01

371

21 CFR 882.5810 - External functional neuromuscular stimulator.  

Code of Federal Regulations, 2010 CFR

...stimulator that uses external electrodes for stimulating muscles in the leg and ankle of partially paralyzed patients (e.g., after stroke) to provide flexion of the foot and thus improve the patient's gait. (b) Classification. Class II...

2010-04-01

372

Anesthesia for deep brain stimulation in a patient with X-linked dystonia-parkinsonism/Lubag disease.  

PubMed

Lubag disease is a genetic X-linked dystonia-parkinsonism syndrome afflicting Filipino men. This disease is characterized by dystonia dominating the first 10-15 years of the disorder, which is associated with or replaced by parkinsonian features in later years of life. A 49-year-old man with Lubag disease underwent general anesthesia for deep brain stimulation (DBS) surgery. Anesthesia was maintained mainly with propofol, remifentanil, rocuronium bromide, and sevoflurane. During magnetic resonance imaging, the patient was anesthetized with midazolam, fentanyl, and rocuronium bromide. The surgery was completed safely using these anesthetic agents. After DBS, some symptoms including involuntary movement improved within 10 days. PMID:23614923

Ohshita, Naohiro; Tanaka, Katsuya; Sakai, Yoko; Katayama, Toshiko; Tomiyama, Yoshinobu; Ohsita, Shuzo; Tsutsumi, Yasuo M

2013-01-01

373

Relationship between Neural Activation and Electric Field Distribution during Deep Brain Stimulation.  

PubMed

Models and simulations are commonly used to study deep brain stimulation (DBS). Simulated stimulation fields are often defined and visualized by electric field isolevels or volumes of tissue activated (VTA). The aim of the present study was to evaluate the relationship between stimulation field strength as defined by the electric potential V, the electric field E, and the divergence of the electric field ?(2) V, and neural activation. Axon cable models were developed and coupled to finite-element DBS models in three-dimensional (3-D). Field thresholds ( VT , ET, and ?(2) VT ) were derived at the location of activation for various stimulation amplitudes (1 to 5 V), pulse widths (30 to 120 ?s), and axon diameters (2.0 to 7.5 ?m). Results showed that thresholds for VT and ?(2) VT were highly dependent on the stimulation amplitude while ET were approximately independent of the amplitude for large axons. The activation field strength thresholds presented in this study may be used in future studies to approximate the VTA during model-based investigations of DBS without the need of computational axon models. PMID:25350910

Astrom, Mattias; Diczfalusy, Elin; Martens, Hubert; Wardell, Karin

2015-02-01

374

NEUROPSYCHOLOGICAL FUNCTION BEFORE AND AFTER SUBCALLOSAL CINGULATE DEEP BRAIN STIMULATION IN PATIENTS WITH TREATMENT-RESISTANT DEPRESSION  

PubMed Central

Background Treatment-resistant depression (TRD) is a pervasive and difficult to treat condition for which deep brain stimulation (DBS) of the subcallosal cingulate white matter (SCCwm) is an emerging therapeutic option. However, neuropsychological safety data for this novel treatment have only been published for a small number of subjects. Moreover, little is known regarding the neuropsychological profile present in TRD patients at baseline, prior to initiation of DBS therapy. This report describes the neuropsychological effects of TRD and acute and chronic DBS of the SCCwm in patients with unipolar and bipolar TRD. Methods Patients with TRD (N =17) were compared to a healthy control group (N = 15) on subtests from the Cambridge Neuropsychological Test Automated Battery and the Stroop Task. Patients were then tested again at subsequent time points of 1 and 6 months following the initiation of chronic DBS of the SCCwm. Results Patients with TRD showed similar levels of performance to healthy controls on most neuropsychological measures, with the exception that the TRD group had slower processing speed. Patients with bipolar TRD, relative to those with unipolar TRD, obtained lower scores on measures of executive function and memory only at baseline. With acute and chronic SCCwm DBS, neuropsychological function improved in multiple domains including processing speed and executive function (planning, set shifting, response inhibition), and memory remained stable. Conclusions Patients with TRD show slowed processing speed but otherwise largely preserved neuropsychological functioning. DBS of the SCCwm does not result in worsening of any aspect of neuropsychological function and may improve certain domains. Future research is warranted to better understand the effects of TRD and DBS on neuropsychological function. PMID:24753183

Moreines, Jared L.; McClintock, Shawn M.; Kelley, Mary E.; Holtzheimer, Paul E.; Mayberg, Helen S.

2014-01-01

375

Working Electrodes  

Microsoft Academic Search

In electrochemistry an electrode is an electronic conductor in contact with an ionic conductor. The electronic conductor can be a metal, or a semiconductor, or a mixed electronic and ionic conductor. The ionic conductor is usually an electrolyte solution; however, solid electrolytes and ionic melts can be used as well. The term \\

Sebojka Komorsky-Lovric

2010-01-01

376

Randomized trial of deep brain stimulation for Parkinson disease  

PubMed Central

Objectives: Our objective was to compare long-term outcomes of deep brain stimulation (DBS) of the globus pallidus interna (GPi) and subthalamic nucleus (STN) for patients with Parkinson disease (PD) in a multicenter randomized controlled trial. Methods: Patients randomly assigned to GPi (n = 89) or STN DBS (n = 70) were followed for 36 months. The primary outcome was motor function on stimulation/off medication using the Unified Parkinson's Disease Rating Scale motor subscale. Secondary outcomes included quality of life and neurocognitive function. Results: Motor function improved between baseline and 36 months for GPi (41.1 to 27.1; 95% confidence interval [CI] ?16.4 to ?10.8; p < 0.001) and STN (42.5 to 29.7; 95% CI ?15.8 to ?9.4; p < 0.001); improvements were similar between targets and stable over time (p = 0.59). Health-related quality of life improved at 6 months on all subscales (all p values significant), but improvement diminished over time. Mattis Dementia Rating Scale scores declined faster for STN than GPi patients (p = 0.01); other neurocognitive measures showed gradual decline overall. Conclusions: The beneficial effect of DBS on motor function was stable and comparable by target over 36 months. Slight declines in quality of life following initial gains and gradual decline in neurocognitive function likely reflect underlying disease progression and highlight the importance of nonmotor symptoms in determining quality of life. Classification of Evidence: This study provides Class III evidence that improvement of motor symptoms of PD by DBS remains stable over 3 years and does not differ by surgical target. Neurology® 2012;79:55–65 PMID:22722632

Follett, Kenneth A.; Stern, Matthew; Luo, Ping; Harris, Crystal L.; Hur, Kwan; Marks, William J.; Rothlind, Johannes; Sagher, Oren; Moy, Claudia; Pahwa, Rajesh; Burchiel, Kim; Hogarth, Penelope; Lai, Eugene C.; Duda, John E.; Holloway, Kathryn; Samii, Ali; Horn, Stacy; Bronstein, Jeff M.; Stoner, Gatana; Starr, Philip A.; Simpson, Richard; Baltuch, Gordon; De Salles, Antonio; Huang, Grant D.; Reda, Domenic J.; Ippolito, Dolores; Barnett, Tammy; Bukowski, Ken; Carlson, Kimberly; Christine, Barbara; DeNicolo, Rosemarie; Jimenez, Joyce; Motyka, Jan; Patel, Unnati; Simon, Theresa; Thakkar, Bharat; Woolson, Robert; Fye, Carol; Gagne, William; Sheehy, Paul; O'Leary, Timothy; Atassi, Farah; Bello, Cecilia; Bunting-Perry, Lisette; Conn, Tina; Cugley, Alice; Eubank, Nanette; Fincher, Linda; Franks, Romay; Harris, Tammy; Haselman, Mariann; Heath, Susan; Hirsch, Miriam; Janovsky, Virginia; Lanier, Elaine; Lloyd, Mary; Loehner, Susan; O'Connor, Susan; Ordonez, Ligaya; Maccarone, Heather; Massey-Makhoul, Kelli; Matthews, Mary; Meyn, Elizabeth; Mimura, Keiko; Morrow, Wes; Searles, Tammy; Valotta, Jamye; Vasthare, Usha; Volz, Monica; Ward, Constance; Warker, Rebecca; Watson, Heidi; Willson, Pamela; Baron, Mark; Brodsky, Matthew; Calabrese, Vincent; Campbell, Gordon; Colcher, Amy; Farag, Emad; Henry, Eva; Hou, Jyh-Gong; Kang, Gail; Kleiner-Fisman, Galit; Kraakevik, Jeff; Nutt, John; Ostrem, Jill; Sarwar, Aliya; Subramanian, Indu; Vanek, Zeba; Carne, William; Erikson, Tom; Kreutzer, Jeffrey; Mendez, Mario; Moberg, Paul; Ragland, John; Seel, Ronald; Soety, Elizabeth; Storzbach, Daniel; Troster, Alexander; York, Michele; Jaggi, Jurg; Stroupe, Kevin; Koller, William

2012-01-01

377

Electrochemical performance of platinum electrodes within the multi-electrode spiral nerve cuff.  

PubMed

In this study, the electrochemical performance of platinum electrodes within a multi-electrode spiral cuff to be used for selective nerve stimulation was investigated. The original cuff, simplified into a half-cuff, contained a single row of nine electrodes (0.5 × 2 mm) at a distance of 2 mm from its inner surface. Cyclic voltammetry was used to investigate the electrochemical reactions at the electrode-electrolyte interface, to define a potential window within which the electrode could be safely used in selective nerve stimulation, to calculate the charge injection capacity and cathodal charge storage capacity. Voltage transients retrieved during excitation with quasitrapezoidal biphasic current pulses, tested by selective nerve stimulation of the isolated porcine left cervical vagus nerve segment, were used to determine the maximum polarization across the electrode-electrolyte interface and to calculate cathodic charge injection capacity of the electrode. The results show that the most negative and most positive potentials across the electrode-electrolyte interface reached -0.54 and 0.59 V; these did not exceed the safe potential limits for water electrolysis. Furthermore, the time integral of the cathodic current by cyclic voltammetry measured over the potential range of water electrolysis, actually representing the cathodal charge storage capacity, was approximately -4 mC cm(-2). The charge injection capacity, representing the maximum charge density injected in a current stimulation pulse, using only reversible processes, however, was around 75 µC cm(-2). In conclusion, both, the tested stimulation pulse and electrode are suitable for efficient and safe selective nerve stimulation. PMID:24938675

Rozman, Janez; Pe?lin, Polona; Mehle, Andraž; Šala, Martin

2014-09-01

378

Learn about Transcutaneous Electrical Nerve Stimulation  

MedlinePLUS

... is considered to be a trigger point or acupuncture point for the painful area. Are there different ... as it is known, is a combination of acupuncture and electrical stimulation. Instead of electrodes, PENS uses ...

379

Trimodal nanoelectrode array for precise deep brain stimulation: prospects of a new technology based on carbon nanofiber arrays  

Microsoft Academic Search

Although deep brain stimulation (DBS) has recently been shown to be effective for neurological disorders such as Parkinson’s\\u000a disease, there are many limitations of the current technology: the large size of current microelectrodes (?1mm diameter);\\u000a the lack of monitoring of local brain electrical activity and neurotransmitters (e.g. dopamine in Parkinson’s disease); the\\u000a open-loop nature of the stimulation (i.e. not guided

J. Li; Russell J. Andrews

380

Long-range correlation properties in timing of skilled piano performance: the influence of auditory feedback and deep brain stimulation  

PubMed Central

Unintentional timing deviations during musical performance can be conceived of as timing errors. However, recent research on humanizing computer-generated music has demonstrated that timing fluctuations that exhibit long-range temporal correlations (LRTC) are preferred by human listeners. This preference can be accounted for by the ubiquitous presence of LRTC in human tapping and rhythmic performances. Interestingly, the manifestation of LRTC in tapping behavior seems to be driven in a subject-specific manner by the LRTC properties of resting-state background cortical oscillatory activity. In this framework, the current study aimed to investigate whether propagation of timing deviations during the skilled, memorized piano performance (without metronome) of 17 professional pianists exhibits LRTC and whether the structure of the correlations is influenced by the presence or absence of auditory feedback. As an additional goal, we set out to investigate the influence of altering the dynamics along the cortico-basal-ganglia-thalamo-cortical network via deep brain stimulation (DBS) on the LRTC properties of musical performance. Specifically, we investigated temporal deviations during the skilled piano performance of a non-professional pianist who was treated with subthalamic-deep brain stimulation (STN-DBS) due to severe Parkinson's disease, with predominant tremor affecting his right upper extremity. In the tremor-affected right hand, the timing fluctuations of the performance exhibited random correlations with DBS OFF. By contrast, DBS restored long-range dependency in the temporal fluctuations, corresponding with the general motor improvement on DBS. Overall, the present investigations demonstrate the presence of LRTC in skilled piano performances, indicating that unintentional temporal deviations are correlated over a wide range of time scales. This phenomenon is stable after removal of the auditory feedback, but is altered by STN-DBS, which suggests that cortico-basal ganglia-thalamocortical circuits play a role in the modulation of the serial correlations of timing fluctuations exhibited in skilled musical performance. PMID:25309487

Herrojo Ruiz, María; Hong, Sang Bin; Hennig, Holger; Altenmüller, Eckart; Kühn, Andrea A.

2014-01-01