Fabrication of multiwall carbon nanotube sheet based hydrogen sensor on a stacking multi-layer structure.

PubMed

Yan, Keyi; Toku, Yuhki; Morita, Yasuyuki; Ju, Yang

2018-06-22

In this research, we propose a new simple method to fabricate hydrogen gas sensor by stacking the multiwall carbon nanotube (MWCNT) sheets. MWCNT sheet offers a larger surface area and more CNT contacts, which are key factors for gas sensing, because of its super-high alignment and end-to-end structure comparing to the traditional CNT film. Besides, MWCNT sheet can be directly drawn from the spinnable CNT array in large scales. Therefore, this method is a potential answer for the mass production and commercialization of CNT based sensor with high response. By stacking different layers of sheet, microstructure and CNT interactions in the layers were changed and their influences towards gas sensing were investigated. It was observed that the sample with 3 layers of sheet and functionalized with 3 nm-thick Pd showed the best gas sensing performance with a response of 12.31% at 4% H2 and response time below 200 s. © 2018 IOP Publishing Ltd.

Design of an Intelligent Front-End Signal Conditioning Circuit for IR Sensors

NASA Astrophysics Data System (ADS)

de Arcas, G.; Ruiz, M.; Lopez, J. M.; Gutierrez, R.; Villamayor, V.; Gomez, L.; Montojo, Mª. T.

2008-02-01

This paper presents the design of an intelligent front-end signal conditioning system for IR sensors. The system has been developed as an interface between a PbSe IR sensor matrix and a TMS320C67x digital signal processor. The system architecture ensures its scalability so it can be used for sensors with different matrix sizes. It includes an integrator based signal conditioning circuit, a data acquisition converter block, and a FPGA based advanced control block that permits including high level image preprocessing routines such as faulty pixel detection and sensor calibration in the signal conditioning front-end. During the design phase virtual instrumentation technologies proved to be a very valuable tool for prototyping when choosing the best A/D converter type for the application. Development time was significantly reduced due to the use of this technology.

Microfabricated Multianalyte Sensor Arrays for Metabolic Monitoring

DTIC Science & Technology

2006-09-01

aqueous in vivo-like surrounding15-18 to entrap both the redox polymer and glucose oxidase on polyimide sheets. We have used biocompatible PEG-DA hydrogel...arrays were fabricated on gold electrodes on flexible polyimide sheets by cross-linking glucose oxidase and redox polymer using UV-initiated free...cyclic voltammetry. We have fabricated an array of glucose sensors on flexible polyimide sheets that exhibit the desired linear response in the

Sensing sheets based on large area electronics for fatigue crack detection

NASA Astrophysics Data System (ADS)

Yao, Yao; Glisic, Branko

2015-03-01

Reliable early-stage damage detection requires continuous structural health monitoring (SHM) over large areas of structure, and with high spatial resolution of sensors. This paper presents the development stage of prototype strain sensing sheets based on Large Area Electronics (LAE), in which thin-film strain gauges and control circuits are integrated on the flexible electronics and deposited on a polyimide sheet that can cover large areas. These sensing sheets were applied for fatigue crack detection on small-scale steel plates. Two types of sensing-sheet interconnects were designed and manufactured, and dense arrays of strain gauge sensors were assembled onto the interconnects. In total, four (two for each design type) strain sensing sheets were created and tested, which were sensitive to strain at virtually every point over the whole sensing sheet area. The sensing sheets were bonded to small-scale steel plates, which had a notch on the boundary so that fatigue cracks could be generated under cyclic loading. The fatigue tests were carried out at the Carleton Laboratory of Columbia University, and the steel plates were attached through a fixture to the loading machine that applied cyclic fatigue load. Fatigue cracks then occurred and propagated across the steel plates, leading to the failure of these test samples. The strain sensor that was close to the notch successfully detected the initialization of fatigue crack and localized the damage on the plate. The strain sensor that was away from the crack successfully detected the propagation of fatigue crack based on the time history of measured strain. Overall, the results of the fatigue tests validated general principles of the strain sensing sheets for crack detection.

Sensing sheet: the response of full-bridge strain sensors to thermal variations for detecting and characterizing cracks

NASA Astrophysics Data System (ADS)

Tung, S.-T.; Glisic, B.

2016-12-01

Sensing sheets based on large-area electronics consist of a dense array of unit strain sensors. This new technology has potential for becoming an effective and affordable monitoring tool that can identify, localize and quantify surface damage in structures. This research contributes to their development by investigating the response of full-bridge unit strain sensors to thermal variations. Overall, this investigation quantifies the effects of temperature on thin-film full-bridge strain sensors monitoring uncracked and cracked concrete. Additionally, an empirical formula is developed to estimate crack width given an observed strain change and a measured temperature change. This research led to the understanding of the behavior of full-bridge strain sensors installed on cracked concrete and exposed to temperature variations. It proves the concept of the sensing sheet and its suitability for application in environments with variable temperature.

Residual stress evaluation by Barkhausen signals with a magnetic field sensor for high efficiency electrical motors

NASA Astrophysics Data System (ADS)

Tsuchida, Yuji; Enokizono, Masato

2018-04-01

The iron loss of industrial motors increases by residual stress during manufacturing processes. It is very important to make clear the distribution of the residual stress in the motor cores to reduce the iron loss in the motors. Barkhausen signals which occur on electrical steel sheets can be used for the evaluation of the residual stress because they are very sensitive to the material properties. Generally, a B-sensor is used to measure Barkhausen signals, however, we developed a new H-sensor to measure them and applied it into the stress evaluation. It is supposed that the Barkhausen signals by using a H-sensor can be much effective to the residual stress on the electrical steel sheets by referring our results regarding to the stress evaluations. We evaluated the tensile stress of the electrical steel sheets by measuring Barkhausen signals by using our developed H-sensor for high efficiency electrical motors.

Hybrid Piezoelectric/Fiber-Optic Sensor Sheets

NASA Technical Reports Server (NTRS)

Lin, Mark; Qing, Xinlin

2004-01-01

Hybrid piezoelectric/fiber-optic (HyPFO) sensor sheets are undergoing development. They are intended for use in nondestructive evaluation and long-term monitoring of the integrity of diverse structures, including aerospace, aeronautical, automotive, and large stationary ones. It is anticipated that the further development and subsequent commercialization of the HyPFO sensor systems will lead to economic benefits in the form of increased safety, reduction of life-cycle costs through real-time structural monitoring, increased structural reliability, reduction of maintenance costs, and increased readiness for service. The concept of a HyPFO sensor sheet is a generalization of the concept of a SMART Layer(TradeMark), which is a patented device that comprises a thin dielectric film containing an embedded network of distributed piezoelectric actuator/sensors. Such a device can be mounted on the surface of a metallic structure or embedded inside a composite-material structure during fabrication of the structure. There is has been substantial interest in incorporating sensors other than piezoelectric ones into SMART Layer(TradeMark) networks: in particular, because of the popularity of the use of fiber-optic sensors for monitoring the "health" of structures in recent years, it was decided to incorporate fiber-optic sensors, giving rise to the concept of HyPFO devices.

Monitoring Cortical Excitability during Repetitive Transcranial Magnetic Stimulation in Children with ADHD: A Single-Blind, Sham-Controlled TMS-EEG Study

PubMed Central

Helfrich, Christian; Pierau, Simone S.; Freitag, Christine M.; Roeper, Jochen; Ziemann, Ulf; Bender, Stephan

2012-01-01

Background Repetitive transcranial magnetic stimulation (rTMS) allows non-invasive stimulation of the human brain. However, no suitable marker has yet been established to monitor the immediate rTMS effects on cortical areas in children. Objective TMS-evoked EEG potentials (TEPs) could present a well-suited marker for real-time monitoring. Monitoring is particularly important in children where only few data about rTMS effects and safety are currently available. Methods In a single-blind sham-controlled study, twenty-five school-aged children with ADHD received subthreshold 1 Hz-rTMS to the primary motor cortex. The TMS-evoked N100 was measured by 64-channel-EEG pre, during and post rTMS, and compared to sham stimulation as an intraindividual control condition. Results TMS-evoked N100 amplitude decreased during 1 Hz-rTMS and, at the group level, reached a stable plateau after approximately 500 pulses. N100 amplitude to supra-threshold single pulses post rTMS confirmed the amplitude reduction in comparison to the pre-rTMS level while sham stimulation had no influence. EEG source analysis indicated that the TMS-evoked N100 change reflected rTMS effects in the stimulated motor cortex. Amplitude changes in TMS-evoked N100 and MEPs (pre versus post 1 Hz-rTMS) correlated significantly, but this correlation was also found for pre versus post sham stimulation. Conclusion The TMS-evoked N100 represents a promising candidate marker to monitor rTMS effects on cortical excitability in children with ADHD. TMS-evoked N100 can be employed to monitor real-time effects of TMS for subthreshold intensities. Though TMS-evoked N100 was a more sensitive parameter for rTMS-specific changes than MEPs in our sample, further studies are necessary to demonstrate whether clinical rTMS effects can be predicted from rTMS-induced changes in TMS-evoked N100 amplitude and to clarify the relationship between rTMS-induced changes in TMS-evoked N100 and MEP amplitudes. The TMS-evoked N100 amplitude reduction after 1 Hz-rTMS could either reflect a globally decreased cortical response to the TMS pulse or a specific decrease in inhibition. PMID:23185537

E-tracers: A New Technique for Wireless Sensing Under Ice Sheets

NASA Astrophysics Data System (ADS)

Burrow, S.; Wadham, J. L.; Salter, M.; Barnes, R.

2009-12-01

A significant hurdle to the understanding of ice sheet basal hydrology and its coupling with ice motion is the difficulty in making in-situ measurements along a flow path. While dye tracing techniques may be used in small glaciers to determine transit times of surface melt water through the sub-glacial system, they provide no information on in situ conditions (e.g. pressure) and are ineffective at ice-sheet scale where dilution is high. The use of tethered sensor packages is complicated by the long lengths (~100’s m) and torturous path of the moulins and conduits within ice sheets. Recent attempts to pass solid objects (rubber ducks) and other sensor packages through glacial moulins have confirmed the difficultly in deploying sensors into the sub glacial environment. Here, we report the first successful deployment and recovery of compact, electronic units to moulins up to 7 km from the margin of a large land-terminating Greenland outlet. The technique uses RF (Radio Frequency) location to create an electronic tracer (an ‘e-tracer’) enabling a data-logging sensor package to be located in the pro-glacial flood plain once it has passed through the ice sheet. A number of individual packages are used in each deployment mitigating for the risk that some may become stuck within the moulin or lodge in an inaccessible part of the floodplain. In preliminary tests on the Leverett glacier in West Greenland during August 2009 we have demonstrated that this technique can be used to locate and retrieve dummy sensor packages: 50% and 20% of the dummy sensor packages introduced to moulins at 1 and 7 km from the ice sheet terminus respectively, emerged in the sub-glacial stream. It was possible to effectively detect the e-tracer units (which broadcast on 151MHz with 10mW of power) over a horizontal range of up to 5km across the pro-glacial floodplain and locate them to a high accuracy, allowing visual recognition and manual recovery. These performance statistics give this technique strong potential for investigating in-situ conditions along a flow path at ice sheet scale.

MR-based measurements and simulations of the magnetic field created by a realistic transcranial magnetic stimulation (TMS) coil and stimulator.

PubMed

Mandija, Stefano; Petrov, Petar I; Neggers, Sebastian F W; Luijten, Peter R; van den Berg, Cornelis A T

2016-11-01

Transcranial magnetic stimulation (TMS) is an emerging technique that allows non-invasive neurostimulation. However, the correct validation of electromagnetic models of typical TMS coils and the correct assessment of the incident TMS field (B TMS ) produced by standard TMS stimulators are still lacking. Such a validation can be performed by mapping B TMS produced by a realistic TMS setup. In this study, we show that MRI can provide precise quantification of the magnetic field produced by a realistic TMS coil and a clinically used TMS stimulator in the region in which neurostimulation occurs. Measurements of the phase accumulation created by TMS pulses applied during a tailored MR sequence were performed in a phantom. Dedicated hardware was developed to synchronize a typical, clinically used, TMS setup with a 3-T MR scanner. For comparison purposes, electromagnetic simulations of B TMS were performed. MR-based measurements allow the mapping and quantification of B TMS starting 2.5 cm from the TMS coil. For closer regions, the intra-voxel dephasing induced by B TMS prohibits TMS field measurements. For 1% TMS output, the maximum measured value was ~0.1 mT. Simulations reflect quantitatively the experimental data. These measurements can be used to validate electromagnetic models of TMS coils, to guide TMS coil positioning, and for dosimetry and quality assessment of concurrent TMS-MRI studies without the need for crude methods, such as motor threshold, for stimulation dose determination. Copyright © 2016 John Wiley & Sons, Ltd.

Graphene-based inline pressure sensor integrated with microfluidic elastic tube

NASA Astrophysics Data System (ADS)

Inoue, Nagisa; Onoe, Hiroaki

2018-01-01

We propose an inline pressure sensor composed of a polydimethylsiloxane (PDMS) microfluidic tube integrated with graphene sheets. The PDMS tube was fabricated through molding, and a multilayered graphene sheet was transferred on the surface of the PDMS tube. The pressure inside the tube was monitored using the changes in the electrical resistance of the transferred graphene. The proposed pressure sensor could be suitable for precise pressure measurement for a small amount of fluid in microfluidic systems including organ-on-a-chip devices.

Optimal timing of pulse onset for language mapping with navigated repetitive transcranial magnetic stimulation.

PubMed

Krieg, Sandro M; Tarapore, Phiroz E; Picht, Thomas; Tanigawa, Noriko; Houde, John; Sollmann, Nico; Meyer, Bernhard; Vajkoczy, Peter; Berger, Mitchel S; Ringel, Florian; Nagarajan, Srikantan

2014-10-15

Within the primary motor cortex, navigated transcranial magnetic stimulation (nTMS) has been shown to yield maps strongly correlated with those generated by direct cortical stimulation (DCS). However, the stimulation parameters for repetitive nTMS (rTMS)-based language mapping are still being refined. For this purpose, the present study compares two rTMS protocols, which differ in the timing of pulse train onset relative to picture presentation onset during object naming. Results were the correlated with DCS language mapping during awake surgery. Thirty-two patients with left-sided perisylvian tumors were examined by rTMS prior to awake surgery. Twenty patients underwent rTMS pulse trains starting at 300 ms after picture presentation onset (delayed TMS), whereas another 12 patients received rTMS pulse trains starting at the picture presentation onset (ONSET TMS). These rTMS results were then evaluated for correlation with intraoperative DCS results as gold standard in terms of differential consistencies in receiver operating characteristics (ROC) statistics. Logistic regression analysis by protocols and brain regions were conducted. Within and around Broca's area, there was no difference in sensitivity (onset TMS: 100%, delayed TMS: 100%), negative predictive value (NPV) (onset TMS: 100%, delayed TMS: 100%), and positive predictive value (PPV) (onset TMS: 55%, delayed TMS: 54%) between the two protocols compared to DCS. However, specificity differed significantly (onset TMS: 67%, delayed TMS: 28%). In contrast, for posterior language regions, such as supramarginal gyrus, angular gyrus, and posterior superior temporal gyrus, early pulse train onset stimulation showed greater specificity (onset TMS: 92%, delayed TMS: 20%), NPV (onset TMS: 92%, delayed TMS: 57%) and PPV (onset TMS: 75%, delayed TMS: 30%) with comparable sensitivity (onset TMS: 75%, delayed TMS: 70%). Logistic regression analysis also confirmed the greater fit of the predictions by rTMS that had the pulse train onset coincident with the picture presentation onset when compared to the delayed stimulation. Analyses of differential disruption patterns of mapped cortical regions were further able to distinguish clusters of cortical regions standardly associated with semantic and pre-vocalization phonological networks proposed in various models of word production. Repetitive nTMS predictions by both protocols correlate well with DCS outcomes especially in Broca's region, particularly with regard to TMS negative predictions. With this study, we have demonstrated that rTMS stimulation onset coincident with picture presentation onset improves the accuracy of preoperative language maps, particularly within posterior language areas. Moreover, immediate and delayed pulse train onsets may have complementary disruption patterns that could differentially capture cortical regions causally necessary for semantic and pre-vocalization phonological networks. Published by Elsevier Inc.

Electrochemical sensors and biosensors based on less aggregated graphene.

PubMed

Bo, Xiangjie; Zhou, Ming; Guo, Liping

2017-03-15

As a novel single-atom-thick sheet of sp 2 hybridized carbon atoms, graphene (GR) has attracted extensive attention in recent years because of its unique and remarkable properties, such as excellent electrical conductivity, large theoretical specific surface area, and strong mechanical strength. However, due to the π-π interaction, GR sheets are inclined to stack together, which may seriously degrade the performance of GR with the unique single-atom layer. In recent years, an increasing number of GR-based electrochemical sensors and biosensors are reported, which may reflect that GR has been considered as a kind of hot and promising electrode material for electrochemical sensor and biosensor construction. However, the active sites on GR surface induced by the irreversible GR aggregations would be deeply secluded inside the stacked GR sheets and therefore are not available for the electrocatalysis. So the alleviation or the minimization of the aggregation level for GR sheets would facilitate the exposure of active sites on GR and effectively upgrade the performance of GR-based electrochemical sensors and biosensors. Less aggregated GR with low aggregation and high dispersed structure can be used in improving the electrochemical activity of GR-based electrochemical sensors or biosensors. In this review, we summarize recent advances and new progress for the development of electrochemical sensors based on less aggregated GR. To achieve such goal, many strategies (such as the intercalation of carbon materials, surface modification, and structural engineering) have been applied to alleviate the aggregation level of GR in order to enhance the performance of GR-based electrochemical sensors and biosensors. Finally, the challenges associated with less aggregated GR-based electrochemical sensors and biosensors as well as related future research directions are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Coefficient of Friction of Human Corneal Tissue.

PubMed

Wilson, Tawnya; Aeschlimann, Rudolf; Tosatti, Samuele; Toubouti, Youssef; Kakkassery, Joseph; Osborn Lorenz, Katherine

2015-09-01

A novel property evaluation methodology was used to determine the elusive value for the human corneal coefficient of friction (CoF). Using a microtribometer on 28 fresh human donor corneas with intact epithelia, the CoF was determined in 4 test solutions (≥5 corneas/solution): tear-mimicking solution (TMS) in borate-buffered saline (TMS-PS), TMS in phosphate-buffered saline (TMS-PBS), TMS with HEPES-buffered saline (TMS-HEPES), and tear-like fluid in PBS (TLF-PBS). Mean (SD) CoF values ranged from 0.006 to 0.015 and were 0.013 (0.010) in TMS-PS, 0.006 (0.003) in TMS-PBS, 0.014 (0.005) in TMS-HEPES, and 0.015 (0.009) in TLF-PBS. Statistically significant differences were shown for TMS-PBS versus TLF (P = 0.0424) and TMS-PBS versus TMS-HEPES (P = 0.0179), but not for TMS-PBS versus TMS-PS (P = 0.2389). Successful measurement of the fresh human corneal tissue CoF was demonstrated, with values differing in the evaluated buffer solutions, within this limited sample size.

Ammonia gas sensors based on chemically reduced graphene oxide sheets self-assembled on Au electrodes

PubMed Central

2014-01-01

We present a useful ammonia gas sensor based on chemically reduced graphene oxide (rGO) sheets by self-assembly technique to create conductive networks between parallel Au electrodes. Negative graphene oxide (GO) sheets with large sizes (>10 μm) can be easily electrostatically attracted onto positive Au electrodes modified with cysteamine hydrochloride in aqueous solution. The assembled GO sheets on Au electrodes can be directly reduced into rGO sheets by hydrazine or pyrrole vapor and consequently provide the sensing devices based on self-assembled rGO sheets. Preliminary results, which have been presented on the detection of ammonia (NH3) gas using this facile and scalable fabrication method for practical devices, suggest that pyrrole-vapor-reduced rGO exhibits much better (more than 2.7 times with the concentration of NH3 at 50 ppm) response to NH3 than that of rGO reduced from hydrazine vapor. Furthermore, this novel gas sensor based on rGO reduced from pyrrole shows excellent responsive repeatability to NH3. Overall, the facile electrostatic self-assembly technique in aqueous solution facilitates device fabrication, the resultant self-assembled rGO-based sensing devices, with miniature, low-cost portable characteristics and outstanding sensing performances, which can ensure potential application in gas sensing fields. PMID:24917701

Science support for the Earth radiation budget sensor on the Nimbus-7 spacecraft

NASA Technical Reports Server (NTRS)

Ingersoll, A. P.

1982-01-01

Experimental data supporting the Earth radiation budget sensor on the Nimbus 7 Satellite is given. The data deals with the empirical relations between radiative flux, cloudiness, and other meteorological parameters; response of a zonal climate ice sheet model to the orbital perturbations during the quaternary ice ages; and a simple parameterization for ice sheet ablation rate.

Natural Flow Air Cooled Photovoltaics

NASA Astrophysics Data System (ADS)

Tanagnostopoulos, Y.; Themelis, P.

2010-01-01

Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. We performed experiments using a prototype based on three silicon photovoltaic modules placed in series to simulate a typical sloping building roof with photovoltaic installation. In this system the air flows through a channel on the rear side of PV panels. The potential for increasing the heat exchange from the photovoltaic panel to the circulating air by the addition of a thin metal sheet (TMS) in the middle of air channel or metal fins (FIN) along the air duct was examined. The operation of the device was studied with the air duct closed tightly to avoid air circulation (CLOSED) and the air duct open (REF), with the thin metal sheet (TMS) and with metal fins (FIN). In each case the experiments were performed under sunlight and the operating parameters of the experimental device determining the electrical and thermal performance of the system were observed and recorded during a whole day and for several days. We collected the data and form PV panels from the comparative diagrams of the experimental results regarding the temperature of solar cells, the electrical efficiency of the installation, the temperature of the back wall of the air duct and the temperature difference in the entrance and exit of the air duct. The comparative results from the measurements determine the improvement in electrical performance of the photovoltaic cells because of the reduction of their temperature, which is achieved by the naturally circulating air.

NPP ATMS Prelaunch Performance Assessment and Sensor Data Record Validation

DTIC Science & Technology

2011-04-29

TMS to sense scattering of cold cosmic background radiance from the tops of preci pitating clouds allows the retrieval of preCipitation intensities...operational and research missions over the last 40 years. The Cross-track Infrared and Microwave Sounding Suite (CrIMSS), consisting of the Cross-track...Infrared Sounder (CrrS) and the flIst space-based, Nyquist-sampled cross-track microwave sounder, the Advanced Technology Microwave Sounder (ATMS), will

Measuring Ultrasonic Acoustic Velocity in a Thin Sheet of Graphite Epoxy Composite

NASA Technical Reports Server (NTRS)

2008-01-01

A method for measuring the acoustic velocity in a thin sheet of a graphite epoxy composite (GEC) material was investigated. This method uses two identical acoustic-emission (AE) sensors, one to transmit and one to receive. The delay time as a function of distance between sensors determines a bulk velocity. A lightweight fixture (balsa wood in the current implementation) provides a consistent method of positioning the sensors, thus providing multiple measurements of the time delay between sensors at different known distances. A linear fit to separation, x, versus delay time, t, will yield an estimate of the velocity from the slope of the line.

JOVE Pilot Research Study in Astronomy and Microgravity Sciences

NASA Technical Reports Server (NTRS)

Strauss, Alvin M.; Hmelo, Anthony; Vlasse; Peterson, Steven

1995-01-01

The purpose of this project was to develop hardware and software facilities for evaluating the biomechanical interactions between human hands and space suit gloves. We have constructed a prototype of the glove to demonstrate its sensing technologies. There are two types of sensors in the glove. The positions of the fingers are measured using bend sensors based on the CyberGlove design. This sensor consists of two strain gages mounted to a 0.003 inch thick mylar sheet. The sensor is encapsulated using 0.001 inch kapton film to give it sufficient rigidity. A long gage is used to average the strain generated in the sensor due to bending. This average strain produces an output signal proportional to the angle of the bend. The force sensor, FSR, is manufactured by Interlink. It consists of conductive ink sandwiched between two plastic sheets. An electrode is printed on one of the plastic sheets using silver ink. When the electrode makes contact, current flows through the conductive ink. The resistance of the ink pad is sensitive to pressure. We have also developed circuits for exciting and measuring the sensors. The current version requires a single sided twelve volt power supply which is one inch long and 0.4 inches in diameter.

A beginner's guide to belief revision and truth maintenance systems

NASA Technical Reports Server (NTRS)

Mason, Cindy L.

1992-01-01

This brief note is intended to familiarize the non-TMS audience with some of the basic ideas surrounding classic TMS's (truth maintenance systems), namely the justification-based TMS and the assumption-based TMS. Topics of further interest include the relation between non-monotonic logics and TMS's, efficiency and search issues, complexity concerns, as well as the variety of TMS systems that have surfaced in the past decade or so. These include probabilistic-based TMS systems, fuzzy TMS systems, tri-valued belief systems, and so on.

Comparative efficacy and acceptability of electroconvulsive therapy versus repetitive transcranial magnetic stimulation for major depression: A systematic review and multiple-treatments meta-analysis.

PubMed

Chen, Jian-Jun; Zhao, Li-Bo; Liu, Yi-Yun; Fan, Song-Hua; Xie, Peng

2017-03-01

The effects of electroconvulsive therapy (ECT) and bilateral, left prefrontal, and right prefrontal repetitive transcranial magnetic stimulation (rTMS) on major depressive disorder (MDD) have not been adequately addressed by previous studies. Here, a multiple-treatments meta-analysis, which incorporates evidence from direct and indirect comparisons from a network of trials, was performed to assess the efficacy and acceptability of these four treatment modalities on MDD. The literature was searched for randomized controlled trials (RCTs) on ECT, bilateral rTMS, and unilateral rTMS for treating MDD up to May 2016. The main outcome measures were response and drop-out rates. Data were obtained from 25 studies consisting of 1288 individuals with MDD. ECT was non-significantly more efficacious than B-rTMS, R-rTMS, and L-rTMS. Left prefrontal rTMS was non -significantly less efficacious than all other treatment modalities. In terms of acceptability, R-rTMS was non-significantly better tolerated than ECT, B-rTMS, and L-rTMS. ECT was the most efficacious treatment with the cumulative probabilities of being the most efficacious treatment being: ECT (65%), B-rTMS (25%), R-rTMS (8%), and L-rTMS (2%). R-rTMS was the best-tolerated treatment with the cumulative probabilities of being the best-tolerated treatment being: R-rTMS (52%), B-rTMS (17%), L-rTMS (16%), and ECT (14%). Coherence analysis detected no statistically significant incoherence in any comparisons of direct with indirect evidence for the response rate and drop-out rate. ECT was the most efficacious, but least tolerated, treatment, while R-rTMS was the best tolerated treatment for MDD. B-rTMS appears to have the most favorable balance between efficacy and acceptability. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization and optimization of flexible dual mode sensor based on Carbon Micro Coils

NASA Astrophysics Data System (ADS)

Dat Nguyen, Tien; Kim, Taeseung; Han, Hyoseung; Shin, Hyun Yeong; Nguyen, Canh Toan; Phung, Hoa; Ryeol Choi, Hyouk

2018-01-01

Carbon Microcoils (CMCs) is a 3D helical micro structure grown via a chemical vapor deposition process. It is noted that composites in which CMCs are embedded in polymer matrixes, called CMC sheets, experience a drastic change of electrical impedance depending on the proximity and contact of external objects. In this paper, a dual functional sensor, that is, tactile and proximity sensor fabricated with CMC/silicone composite is presented to demonstrate the advanced characteristics of CMCs sheets. Characteristics of sensor responses depending on CMC compositions are investigated and optimal conditions are determined. The candidates of polymer matrices are also investigated. As the results, the CMC sheet consisting of Ecoflex 30, CMC 30 {{wt}} % , and multiwall carbon nanotubes 1 {{wt}} % shows the most appropriate tactile sensing characteristics with more than 1 mm of thickness. The proximity sensing capability is the maximum when the 1.5 {{wt}} % CMC content is mixed with Dragon skin 30 silicone substrate. Finally, multiple target objects are recognized with the results and their feasibilities are experimentally validated.

Scene-based Shack-Hartmann wavefront sensor for light-sheet microscopy

NASA Astrophysics Data System (ADS)

Lawrence, Keelan; Liu, Yang; Dale, Savannah; Ball, Rebecca; VanLeuven, Ariel J.; Sornborger, Andrew; Lauderdale, James D.; Kner, Peter

2018-02-01

Light-sheet microscopy is an ideal imaging modality for long-term live imaging in model organisms. However, significant optical aberrations can be present when imaging into an organism that is hundreds of microns or greater in size. To measure and correct optical aberrations, an adaptive optics system must be incorporated into the microscope. Many biological samples lack point sources that can be used as guide stars with conventional Shack-Hartmann wavefront sensors. We have developed a scene-based Shack-Hartmann wavefront sensor for measuring the optical aberrations in a light-sheet microscopy system that does not require a point-source and can measure the aberrations for different parts of the image. The sensor has 280 lenslets inside the pupil, creates an image from each lenslet with a 500 micron field of view and a resolution of 8 microns, and has a resolution for the wavefront gradient of 75 milliradians per lenslet. We demonstrate the system on both fluorescent bead samples and zebrafish embryos.

Tracking the Effect of Cathodal Transcranial Direct Current Stimulation on Cortical Excitability and Connectivity by Means of TMS-EEG

PubMed Central

Varoli, Erica; Pisoni, Alberto; Mattavelli, Giulia C.; Vergallito, Alessandra; Gallucci, Alessia; Mauro, Lilia D.; Rosanova, Mario; Bolognini, Nadia; Vallar, Giuseppe; Romero Lauro, Leonor J.

2018-01-01

Transcranial direct current stimulation (tDCS) is increasingly used in both research and therapeutic settings, but its precise mechanisms remain largely unknown. At a neuronal level, tDCS modulates cortical excitability by shifting the resting membrane potential in a polarity-dependent way: anodal stimulation increases the spontaneous firing rate, while cathodal decreases it. However, the neurophysiological underpinnings of anodal/cathodal tDCS seem to be different, as well as their behavioral effect, in particular when high order areas are involved, compared to when motor or sensory brain areas are targeted. Previously, we investigated the effect of anodal tDCS on cortical excitability, by means of a combination of Transcranial Magnetic Stimulation (TMS) and Electroencephalography (EEG). Results showed a diffuse rise of cortical excitability in a bilateral fronto-parietal network. In the present study, we tested, with the same paradigm, the effect of cathodal tDCS. Single pulse TMS was delivered over the left posterior parietal cortex (PPC), before, during, and after 10 min of cathodal or sham tDCS over the right PPC, while recording HD-EEG. Indexes of global and local cortical excitability were obtained both at sensors and cortical sources level. At sensors, global and local mean field power (GMFP and LMFP) were computed for three temporal windows (0–50, 50–100, and 100–150 ms), on all channels (GMFP), and in four different clusters of electrodes (LMFP, left and right, in frontal and parietal regions). After source reconstruction, Significant Current Density was computed at the global level, and for four Broadmann's areas (left/right BA 6 and 7). Both sensors and cortical sources results converge in showing no differences during and after cathodal tDCS compared to pre-stimulation sessions, both at global and local level. The same holds for sham tDCS. These data highlight an asymmetric impact of anodal and cathodal stimulation on cortical excitability, with a diffuse effect of anodal and no effect of cathodal tDCS over the parietal cortex. These results are consistent with the current literature: while anodal-excitatory and cathodal-inhibitory effects are well-established in the sensory and motor domains, both at physiological and behavioral levels, results for cathodal stimulation are more controversial for modulation of exitability of higher order areas. PMID:29867330

Possible Mechanisms Underlying the Therapeutic Effects of Transcranial Magnetic Stimulation

PubMed Central

Chervyakov, Alexander V.; Chernyavsky, Andrey Yu.; Sinitsyn, Dmitry O.; Piradov, Michael A.

2015-01-01

Transcranial magnetic stimulation (TMS) is an effective method used to diagnose and treat many neurological disorders. Although repetitive TMS (rTMS) has been used to treat a variety of serious pathological conditions including stroke, depression, Parkinson’s disease, epilepsy, pain, and migraines, the pathophysiological mechanisms underlying the effects of long-term TMS remain unclear. In the present review, the effects of rTMS on neurotransmitters and synaptic plasticity are described, including the classic interpretations of TMS effects on synaptic plasticity via long-term potentiation and long-term depression. We also discuss the effects of rTMS on the genetic apparatus of neurons, glial cells, and the prevention of neuronal death. The neurotrophic effects of rTMS on dendritic growth and sprouting and neurotrophic factors are described, including change in brain-derived neurotrophic factor concentration under the influence of rTMS. Also, non-classical effects of TMS related to biophysical effects of magnetic fields are described, including the quantum effects, the magnetic spin effects, genetic magnetoreception, the macromolecular effects of TMS, and the electromagnetic theory of consciousness. Finally, we discuss possible interpretations of TMS effects according to dynamical systems theory. Evidence suggests that a rTMS-induced magnetic field should be considered a separate physical factor that can be impactful at the subatomic level and that rTMS is capable of significantly altering the reactivity of molecules (radicals). It is thought that these factors underlie the therapeutic benefits of therapy with TMS. Future research on these mechanisms will be instrumental to the development of more powerful and reliable TMS treatment protocols. PMID:26136672

Possible Mechanisms Underlying the Therapeutic Effects of Transcranial Magnetic Stimulation.

PubMed

Chervyakov, Alexander V; Chernyavsky, Andrey Yu; Sinitsyn, Dmitry O; Piradov, Michael A

2015-01-01

Transcranial magnetic stimulation (TMS) is an effective method used to diagnose and treat many neurological disorders. Although repetitive TMS (rTMS) has been used to treat a variety of serious pathological conditions including stroke, depression, Parkinson's disease, epilepsy, pain, and migraines, the pathophysiological mechanisms underlying the effects of long-term TMS remain unclear. In the present review, the effects of rTMS on neurotransmitters and synaptic plasticity are described, including the classic interpretations of TMS effects on synaptic plasticity via long-term potentiation and long-term depression. We also discuss the effects of rTMS on the genetic apparatus of neurons, glial cells, and the prevention of neuronal death. The neurotrophic effects of rTMS on dendritic growth and sprouting and neurotrophic factors are described, including change in brain-derived neurotrophic factor concentration under the influence of rTMS. Also, non-classical effects of TMS related to biophysical effects of magnetic fields are described, including the quantum effects, the magnetic spin effects, genetic magnetoreception, the macromolecular effects of TMS, and the electromagnetic theory of consciousness. Finally, we discuss possible interpretations of TMS effects according to dynamical systems theory. Evidence suggests that a rTMS-induced magnetic field should be considered a separate physical factor that can be impactful at the subatomic level and that rTMS is capable of significantly altering the reactivity of molecules (radicals). It is thought that these factors underlie the therapeutic benefits of therapy with TMS. Future research on these mechanisms will be instrumental to the development of more powerful and reliable TMS treatment protocols.

TMS-EEG: From basic research to clinical applications

NASA Astrophysics Data System (ADS)

Hernandez-Pavon, Julio C.; Sarvas, Jukka; Ilmoniemi, Risto J.

2014-11-01

Transcranial magnetic stimulation (TMS) combined with electroencephalography (EEG) is a powerful technique for non-invasively studying cortical excitability and connectivity. The combination of TMS and EEG has widely been used to perform basic research and recently has gained importance in different clinical applications. In this paper, we will describe the physical and biological principles of TMS-EEG and different applications in basic research and clinical applications. We will present methods based on independent component analysis (ICA) for studying the TMS-evoked EEG responses. These methods have the capability to remove and suppress large artifacts, making it feasible, for instance, to study language areas with TMS-EEG. We will discuss the different applications and limitations of TMS and TMS-EEG in clinical applications. Potential applications of TMS are presented, for instance in neurosurgical planning, depression and other neurological disorders. Advantages and disadvantages of TMS-EEG and its variants such as repetitive TMS (rTMS) are discussed in comparison to other brain stimulation and neuroimaging techniques. Finally, challenges that researchers face when using this technique will be summarized.

Low-frequency rTMS inhibitory effects in the primary motor cortex: Insights from TMS-evoked potentials.

PubMed

Casula, Elias P; Tarantino, Vincenza; Basso, Demis; Arcara, Giorgio; Marino, Giuliana; Toffolo, Gianna Maria; Rothwell, John C; Bisiacchi, Patrizia S

2014-09-01

The neuromodulatory effects of repetitive transcranial magnetic stimulation (rTMS) have been mostly investigated by peripheral motor-evoked potentials (MEPs). New TMS-compatible EEG systems allow a direct investigation of the stimulation effects through the analysis of TMS-evoked potentials (TEPs). We investigated the effects of 1-Hz rTMS over the primary motor cortex (M1) of 15 healthy volunteers on TEP evoked by single pulse TMS over the same area. A second experiment in which rTMS was delivered over the primary visual cortex (V1) of 15 healthy volunteers was conducted to examine the spatial specificity of the effects. Single-pulse TMS evoked four main components: P30, N45, P60 and N100. M1-rTMS resulted in a significant decrease of MEP amplitude and in a significant increase of P60 and N100 amplitude. There was no effect after V1-rTMS. 1-Hz rTMS appears to increase the amount of inhibition following a TMS pulse, as demonstrated by the higher N100 and P60, which are thought to originate from GABAb-mediated inhibitory post-synaptic potentials. Our results confirm the reliability of the TMS-evoked N100 as a marker of cortical inhibition and provide insight into the neuromodulatory effects of 1-Hz rTMS. The present finding could be of relevance for therapeutic and diagnostic purposes. Copyright © 2014 Elsevier Inc. All rights reserved.

Visual awareness suppression by pre-stimulus brain stimulation; a neural effect.

PubMed

Jacobs, Christianne; Goebel, Rainer; Sack, Alexander T

2012-01-02

Transcranial magnetic stimulation (TMS) has established the functional relevance of early visual cortex (EVC) for visual awareness with great temporal specificity non-invasively in conscious human volunteers. Many studies have found a suppressive effect when TMS was applied over EVC 80-100 ms after the onset of the visual stimulus (post-stimulus TMS time window). Yet, few studies found task performance to also suffer when TMS was applied even before visual stimulus presentation (pre-stimulus TMS time window). This pre-stimulus TMS effect, however, remains controversially debated and its origin had mainly been ascribed to TMS-induced eye-blinking artifacts. Here, we applied chronometric TMS over EVC during the execution of a visual discrimination task, covering an exhaustive range of visual stimulus-locked TMS time windows ranging from -80 pre-stimulus to 300 ms post-stimulus onset. Electrooculographical (EoG) recordings, sham TMS stimulation, and vertex TMS stimulation controlled for different types of non-neural TMS effects. Our findings clearly reveal TMS-induced masking effects for both pre- and post-stimulus time windows, and for both objective visual discrimination performance and subjective visibility. Importantly, all effects proved to be still present after post hoc removal of eye blink trials, suggesting a neural origin for the pre-stimulus TMS suppression effect on visual awareness. We speculate based on our data that TMS exerts its pre-stimulus effect via generation of a neural state which interacts with subsequent visual input. Copyright © 2011 Elsevier Inc. All rights reserved.

Innovative Pressure Sensor Platform and Its Integration with an End-User Application

PubMed Central

Flores-Caballero, Antonio; Copaci, Dorin; Blanco, María Dolores; Moreno, Luis; Herrán, Jaime; Fernández, Iván; Ochoteco, Estíbaliz; Cabañero, German; Grande, Hans

2014-01-01

This paper describes the fully integration of an innovative and low-cost pressure sensor sheet based on a bendable and printed electronics technology. All integration stages are covered, from most low-level functional system, like physical analog sensor data acquisition, followed by embedded data processing, to end user interactive visual application. Data acquisition embedded software and hardware was developed using a Rapid Control Prototyping (RCP). Finally, after first electronic prototype successful testing, a Taylor-made electronics was developed, reducing electronics volume to 3.5 cm × 6 cm × 2 cm with a maximum power consumption of 765 mW for both electronics and pressure sensor sheet. PMID:24922455

JOVE Pilot Research Study in Astronomy and Microgravity Sciences

NASA Technical Reports Server (NTRS)

Strauss, Alvin M.; Hmelo, Anthony; Peterson, Steven

1996-01-01

The purpose of this project was to develop hardware and software facilities for evaluating the biomechanical interactions between human hands and space suit gloves. The first task was to measure finger joint angles inside space suit gloves. A preliminary survey identified three potential systems which could be used in the proposed study. In response to the current market situation, a glove for measuring the positions of the hand inside a space suit has been developed. A prototype of the glove has been constructed to demonstrate its sensing technologies. There are two types of sensors in the glove. The positions of the fingers are measured using bend sensors based on the CyberGlove design. This sensor consists of two strain gages mounted to a 0.003 inch thick mylar sheet. The sensor is encapsulated using 0.001 inch kapton film to give it sufficient rigidity. Along gage is used to average the strain generated in the sensor due to bending This average strain produces an output signal proportional to the angle of the bend. The force sensor consists of conductive ink sandwiched between two plastic sheets. An electrode is printed on one of the plastic sheets using silver ink. The resistance of the ink is sensitive to pressure.

Transcranial magnetic stimulation (TMS) coupled with electroencephalography (EEG): Biomarker of the future.

PubMed

Kimiskidis, V K

2016-02-01

In recent years, a number of novel brain-stimulation techniques have been developed (such as TMS-EEG, TMS-fMRI and TMS-NIRS), yet they remain underutilized in the field of epilepsy. Accumulating evidence suggests that transcranial magnetic stimulation (TMS) combined with electroencephalography (TMS-EEG) is a highly relevant technique for exploration of the pathophysiology of human epilepsies as well as a promising biomarker with diagnostic and prognostic potential. In genetic generalized epilepsies, TMS-EEG has provided pathophysiological insight by revealing quasi-stable, covert states of excitability, a subclass of which is associated with the generation of TMS-induced epileptiform discharges (EDs). In focal epilepsy, TMS-induced EDs were successfully employed to identify the epileptogenic zone. In addition, TMS trains applied during focal EDs can terminate them, and appear to restore the effective connectivity of the brain network significantly altered by EDs. This abortive effect of TMS on EDs may possibly serve as a biomarker of response to invasive neuromodulatory techniques. TMS-EEG-based stimulation paradigms can provide insight into the mechanisms underlying human epilepsies and, thus, warrant further study as diagnostic and prognostic biomarkers. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

VPI - VIBRATION PATTERN IMAGER: A CONTROL AND DATA ACQUISITION SYSTEM FOR SCANNING LASER VIBROMETERS

NASA Technical Reports Server (NTRS)

Rizzi, S. A.

1994-01-01

The Vibration Pattern Imager (VPI) system was designed to control and acquire data from laser vibrometer sensors. The PC computer based system uses a digital signal processing (DSP) board and an analog I/O board to control the sensor and to process the data. The VPI system was originally developed for use with the Ometron VPI Sensor (Ometron Limited, Kelvin House, Worsley Bridge Road, London, SE26 5BX, England), but can be readily adapted to any commercially available sensor which provides an analog output signal and requires analog inputs for control of mirror positioning. VPI's graphical user interface allows the operation of the program to be controlled interactively through keyboard and mouse-selected menu options. The main menu controls all functions for setup, data acquisition, display, file operations, and exiting the program. Two types of data may be acquired with the VPI system: single point or "full field". In the single point mode, time series data is sampled by the A/D converter on the I/O board at a user-defined rate for the selected number of samples. The position of the measuring point, adjusted by mirrors in the sensor, is controlled via a mouse input. In the "full field" mode, the measurement point is moved over a user-selected rectangular area with up to 256 positions in both x and y directions. The time series data is sampled by the A/D converter on the I/O board and converted to a root-mean-square (rms) value by the DSP board. The rms "full field" velocity distribution is then uploaded for display and storage. VPI is written in C language and Texas Instruments' TMS320C30 assembly language for IBM PC series and compatible computers running MS-DOS. The program requires 640K of RAM for execution, and a hard disk with 10Mb or more of disk space is recommended. The program also requires a mouse, a VGA graphics display, a Four Channel analog I/O board (Spectrum Signal Processing, Inc.; Westborough, MA), a break-out box and a Spirit-30 board (Sonitech International, Inc.; Wellesley, MA) which includes a TMS320C30 DSP processor, 256Kb zero wait state SRAM, and a daughter board with 8Mb one wait state DRAM. Please contact COSMIC for additional information on required hardware and software. In order to compile the provided VPI source code, a Microsoft C version 6.0 compiler, a Texas Instruments' TMS320C30 assembly language compiler, and the Spirit 30 run time libraries are required. A math co-processor is highly recommended. A sample MS-DOS executable is provided on the distribution medium. The standard distribution medium for this program is one 5.25 inch 360K MS-DOS format diskette. The contents of the diskettes are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. VPI was developed in 1991-1992.

Repetitive transcranial magnetic stimulator with controllable pulse parameters

NASA Astrophysics Data System (ADS)

Peterchev, Angel V.; Murphy, David L.; Lisanby, Sarah H.

2011-06-01

The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10-310 µs and positive/negative phase amplitude ratio of 1-56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation up to 82% and 57% and decreases coil heating up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications and could lead to clinical applications with potentially enhanced potency.

Characterizing and Modulating Brain Circuitry through Transcranial Magnetic Stimulation Combined with Electroencephalography.

PubMed

Farzan, Faranak; Vernet, Marine; Shafi, Mouhsin M D; Rotenberg, Alexander; Daskalakis, Zafiris J; Pascual-Leone, Alvaro

2016-01-01

The concurrent combination of transcranial magnetic stimulation (TMS) with electroencephalography (TMS-EEG) is a powerful technology for characterizing and modulating brain networks across developmental, behavioral, and disease states. Given the global initiatives in mapping the human brain, recognition of the utility of this technique is growing across neuroscience disciplines. Importantly, TMS-EEG offers translational biomarkers that can be applied in health and disease, across the lifespan, and in humans and animals, bridging the gap between animal models and human studies. However, to utilize the full potential of TMS-EEG methodology, standardization of TMS-EEG study protocols is needed. In this article, we review the principles of TMS-EEG methodology, factors impacting TMS-EEG outcome measures, and the techniques for preventing and correcting artifacts in TMS-EEG data. To promote the standardization of this technique, we provide comprehensive guides for designing TMS-EEG studies and conducting TMS-EEG experiments. We conclude by reviewing the application of TMS-EEG in basic, cognitive and clinical neurosciences, and evaluate the potential of this emerging technology in brain research.

Repetitive transcranial magnetic stimulator with controllable pulse parameters.

PubMed

Peterchev, Angel V; Murphy, David L; Lisanby, Sarah H

2011-06-01

The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10-310 µs and positive/negative phase amplitude ratio of 1-56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation up to 82% and 57% and decreases coil heating up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications and could lead to clinical applications with potentially enhanced potency.

Characterizing and Modulating Brain Circuitry through Transcranial Magnetic Stimulation Combined with Electroencephalography

PubMed Central

Farzan, Faranak; Vernet, Marine; Shafi, Mouhsin M. D.; Rotenberg, Alexander; Daskalakis, Zafiris J.; Pascual-Leone, Alvaro

2016-01-01

The concurrent combination of transcranial magnetic stimulation (TMS) with electroencephalography (TMS-EEG) is a powerful technology for characterizing and modulating brain networks across developmental, behavioral, and disease states. Given the global initiatives in mapping the human brain, recognition of the utility of this technique is growing across neuroscience disciplines. Importantly, TMS-EEG offers translational biomarkers that can be applied in health and disease, across the lifespan, and in humans and animals, bridging the gap between animal models and human studies. However, to utilize the full potential of TMS-EEG methodology, standardization of TMS-EEG study protocols is needed. In this article, we review the principles of TMS-EEG methodology, factors impacting TMS-EEG outcome measures, and the techniques for preventing and correcting artifacts in TMS-EEG data. To promote the standardization of this technique, we provide comprehensive guides for designing TMS-EEG studies and conducting TMS-EEG experiments. We conclude by reviewing the application of TMS-EEG in basic, cognitive and clinical neurosciences, and evaluate the potential of this emerging technology in brain research. PMID:27713691

Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research☆

PubMed Central

Rossi, Simone; Hallett, Mark; Rossini, Paolo M.; Pascual-Leone, Alvaro

2011-01-01

This article is based on a consensus conference, which took place in Certosa di Pontignano, Siena (Italy) on March 7–9, 2008, intended to update the previous safety guidelines for the application of transcranial magnetic stimulation (TMS) in research and clinical settings. Over the past decade the scientific and medical community has had the opportunity to evaluate the safety record of research studies and clinical applications of TMS and repetitive TMS (rTMS). In these years the number of applications of conventional TMS has grown impressively, new paradigms of stimulation have been developed (e.g., patterned repetitive TMS) and technical advances have led to new device designs and to the real-time integration of TMS with electroencephalography (EEG), positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). Thousands of healthy subjects and patients with various neurological and psychiatric diseases have undergone TMS allowing a better assessment of relative risks. The occurrence of seizures (i.e., the most serious TMS-related acute adverse effect) has been extremely rare, with most of the few new cases receiving rTMS exceeding previous guidelines, often in patients under treatment with drugs which potentially lower the seizure threshold. The present updated guidelines review issues of risk and safety of conventional TMS protocols, address the undesired effects and risks of emerging TMS interventions, the applications of TMS in patients with implanted electrodes in the central nervous system, and safety aspects of TMS in neuroimaging environments. We cover recommended limits of stimulation parameters and other important precautions, monitoring of subjects, expertise of the rTMS team, and ethical issues. While all the recommendations here are expert based, they utilize published data to the extent possible. PMID:19833552

Transcranial magnetic stimulation and neuroplasticity.

PubMed

Pascual-Leone, A; Tarazona, F; Keenan, J; Tormos, J M; Hamilton, R; Catala, M D

1999-02-01

We review past results and present novel data to illustrate different ways in which TMS can be used to study neural plasticity. Procedural learning during the serial reaction time task (SRTT) is used as a model of neural plasticity to illustrate the applications of TMS. These different applications of TMS represent principles of use that we believe are applicable to studies of cognitive neuroscience in general and exemplify the great potential of TMS in the study of brain and behavior. We review the use of TMS for (1) cortical output mapping using focal, single-pulse TMS; (2) identification of the mechanisms underlying neuroplasticity using paired-pulse TMS techniques; (3) enhancement of the information of other neuroimaging techniques by transient disruption of cortical function using repetitive TMS; and finally (4) modulation of cortical function with repetitive TMS to influence behavior and guide plasticity.

Repetitive Transcranial Magnetic Stimulator with Controllable Pulse Parameters

PubMed Central

Peterchev, Angel V; Murphy, David L; Lisanby, Sarah H

2013-01-01

The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10–310 μs and positive/negative phase amplitude ratio of 1–56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation by up to 82% and 57%, and decreases coil heating by up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3,000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications, and could lead to clinical applications with potentially enhanced potency. PMID:21540487

Should we expand the toolbox of psychiatric treatment methods to include Repetitive Transcranial Magnetic Stimulation (rTMS)? A meta-analysis of the efficacy of rTMS in psychiatric disorders.

PubMed

Slotema, Christina W; Blom, Jan Dirk; Hoek, Hans W; Sommer, Iris E C

2010-07-01

Repetitive transcranial magnetic stimulation (rTMS) is a safe treatment method with few side effects. However, efficacy for various psychiatric disorders is currently not clear. A literature search was performed from 1966 through October 2008 using PubMed, Ovid Medline, Embase Psychiatry, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, and PsycINFO. The following search terms were used: transcranial magnetic stimulation, TMS, repetitive TMS, psychiatry, mental disorder, psychiatric disorder, anxiety disorder, attention-deficit hyperactivity disorder, bipolar disorder, catatonia, mania, depression, obsessive-compulsive disorder, psychosis, posttraumatic stress disorder, schizophrenia, Tourette's syndrome, bulimia nervosa, and addiction. Data were obtained from randomized, sham-controlled studies of rTMS treatment for depression (34 studies), auditory verbal hallucinations (AVH, 7 studies), negative symptoms in schizophrenia (7 studies), and obsessive-compulsive disorder (OCD, 3 studies). Studies of rTMS versus electroconvulsive treatment (ECT, 6 studies) for depression were meta-analyzed. Standardized mean effect sizes of rTMS versus sham were computed based on pretreatment-posttreatment comparisons. The mean weighted effect size of rTMS versus sham for depression was 0.55 (P < .001). Monotherapy with rTMS was more effective than rTMS as adjunctive to antidepressant medication. ECT was superior to rTMS in the treatment of depression (mean weighted effect size -0.47, P = .004). In the treatment of AVH, rTMS was superior to sham treatment, with a mean weighted effect size of 0.54 (P < .001). The mean weighted effect size for rTMS versus sham in the treatment of negative symptoms in schizophrenia was 0.39 (P = .11) and for OCD, 0.15 (P = .52). Side effects were mild, yet more prevalent with high-frequency rTMS at frontal locations. It is time to provide rTMS as a clinical treatment method for depression, for auditory verbal hallucinations, and possibly for negative symptoms. We do not recommend rTMS for the treatment of OCD. (c) Copyright 2010 Physicians Postgraduate Press, Inc.

TMS effects on subjective and objective measures of vision: stimulation intensity and pre- versus post-stimulus masking.

PubMed

de Graaf, Tom A; Cornelsen, Sonja; Jacobs, Christianne; Sack, Alexander T

2011-12-01

Transcranial magnetic stimulation (TMS) can be used to mask visual stimuli, disrupting visual task performance or preventing visual awareness. While TMS masking studies generally fix stimulation intensity, we hypothesized that varying the intensity of TMS pulses in a masking paradigm might inform several ongoing debates concerning TMS disruption of vision as measured subjectively versus objectively, and pre-stimulus (forward) versus post-stimulus (backward) TMS masking. We here show that both pre-stimulus TMS pulses and post-stimulus TMS pulses could strongly mask visual stimuli. We found no dissociations between TMS effects on the subjective and objective measures of vision for any masking window or intensity, ruling out the option that TMS intensity levels determine whether dissociations between subjective and objective vision are obtained. For the post-stimulus time window particularly, we suggest that these data provide new constraints for (e.g. recurrent) models of vision and visual awareness. Finally, our data are in line with the idea that pre-stimulus masking operates differently from conventional post-stimulus masking. Copyright © 2011 Elsevier Inc. All rights reserved.

Stochastic resonance effects reveal the neural mechanisms of transcranial magnetic stimulation

PubMed Central

Schwarzkopf, Dietrich Samuel; Silvanto, Juha; Rees, Geraint

2011-01-01

Transcranial magnetic stimulation (TMS) is a popular method for studying causal relationships between neural activity and behavior. However its mode of action remains controversial, and so far there is no framework to explain its wide range of facilitatory and inhibitory behavioral effects. While some theoretical accounts suggests that TMS suppresses neuronal processing, other competing accounts propose that the effects of TMS result from the addition of noise to neuronal processing. Here we exploited the stochastic resonance phenomenon to distinguish these theoretical accounts and determine how TMS affects neuronal processing. Specifically, we showed that online TMS can induce stochastic resonance in the human brain. At low intensity, TMS facilitated the detection of weak motion signals but with higher TMS intensities and stronger motion signals we found only impairment in detection. These findings suggest that TMS acts by adding noise to neuronal processing, at least in an online TMS protocol. Importantly, such stochastic resonance effects may also explain why TMS parameters that under normal circumstances impair behavior, can induce behavioral facilitations when the stimulated area is in an adapted or suppressed state. PMID:21368025

Evaluating interhemispheric cortical responses to transcranial magnetic stimulation in chronic stroke: A TMS-EEG investigation.

PubMed

Borich, Michael R; Wheaton, Lewis A; Brodie, Sonia M; Lakhani, Bimal; Boyd, Lara A

2016-04-08

TMS-evoked cortical responses can be measured using simultaneous electroencephalography (TMS-EEG) to directly quantify cortical connectivity in the human brain. The purpose of this study was to evaluate interhemispheric cortical connectivity between the primary motor cortices (M1s) in participants with chronic stroke and controls using TMS-EEG. Ten participants with chronic stroke and four controls were tested. TMS-evoked responses were recorded at rest and during a typical TMS assessment of transcallosal inhibition (TCI). EEG recordings from peri-central gyral electrodes (C3 and C4) were evaluated using imaginary phase coherence (IPC) analyses to quantify levels of effective interhemispheric connectivity. Significantly increased TMS-evoked beta (15-30Hz frequency range) IPC was observed in the stroke group during ipsilesional M1 stimulation compared to controls during TCI assessment but not at rest. TMS-evoked beta IPC values were associated with TMS measures of transcallosal inhibition across groups. These results suggest TMS-evoked EEG responses can index abnormal effective interhemispheric connectivity in chronic stroke. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Hippocampal-targeted Theta-burst Stimulation Enhances Associative Memory Formation.

PubMed

Tambini, Arielle; Nee, Derek Evan; D'Esposito, Mark

2018-06-19

The hippocampus plays a critical role in episodic memory, among other cognitive functions. However, few tools exist to causally manipulate hippocampal function in healthy human participants. Recent work has targeted hippocampal-cortical networks by performing TMS to a region interconnected with the hippocampus, posterior inferior parietal cortex (pIPC). Such hippocampal-targeted TMS enhances associative memory and influences hippocampal functional connectivity. However, it is currently unknown which stages of mnemonic processing (encoding or retrieval) are affected by hippocampal-targeted TMS. Here, we examined whether hippocampal-targeted TMS influences the initial encoding of associations (vs. items) into memory. To selectively influence encoding and not retrieval, we performed continuous theta-burst TMS before participants encoded object-location associations and assessed memory after the direct effect of stimulation dissipated. Relative to control TMS and baseline memory, pIPC TMS enhanced associative memory success and confidence. Item memory was unaffected, demonstrating a selective influence on associative versus item memory. The strength of hippocampal-pIPC functional connectivity predicted TMS-related memory benefits, which was mediated by parahippocampal and retrosplenial cortices. Our findings indicate that hippocampal-targeted TMS can specifically modulate the encoding of new associations into memory without directly influencing retrieval processes and suggest that the ability to influence associative memory may be related to the fidelity of hippocampal TMS targeting. Our results support the notion that pIPC TMS may serve as a potential tool for manipulating hippocampal function in healthy participants. Nonetheless, future work combining hippocampal-targeted continuous theta-burst TMS with neuroimaging is needed to better understand the neural basis of TMS-induced memory changes.

Lifting the veil on the dynamics of neuronal activities evoked by transcranial magnetic stimulation

PubMed Central

Li, Bingshuo; Virtanen, Juha P; Oeltermann, Axel; Schwarz, Cornelius; Giese, Martin A; Ziemann, Ulf

2017-01-01

Transcranial magnetic stimulation (TMS) is a widely used non-invasive tool to study and modulate human brain functions. However, TMS-evoked activity of individual neurons has remained largely inaccessible due to the large TMS-induced electromagnetic fields. Here, we present a general method providing direct in vivo electrophysiological access to TMS-evoked neuronal activity 0.8–1 ms after TMS onset. We translated human single-pulse TMS to rodents and unveiled time-grained evoked activities of motor cortex layer V neurons that show high-frequency spiking within the first 6 ms depending on TMS-induced current orientation and a multiphasic spike-rhythm alternating between excitation and inhibition in the 6–300 ms epoch, all of which can be linked to various human TMS responses recorded at the level of spinal cord and muscles. The advance here facilitates a new level of insight into the TMS-brain interaction that is vital for developing this non-invasive tool to purposefully explore and effectively treat the human brain. PMID:29165241

Cortical excitability and neurology: insights into the pathophysiology

PubMed Central

Badawy, Radwa A.B.; Loetscher, Tobias; Macdonell, Richard A.L.; Brodtmann, Amy

2012-01-01

Summary Transcranial magnetic stimulation (TMS) is a technique developed to non-invasively investigate the integrity of human motor corticospinal tracts. Over the last three decades, the use of stimulation paradigms including single-pulse TMS, paired-pulse TMS, repetitive TMS, and integration with EEG and functional imaging have been developed to facilitate measurement of cortical excitability. Through the use of these protocols, TMS has evolved into an excellent tool for measuring cortical excitability. TMS has high sensitivity in detecting subtle changes in cortical excitability, and therefore it is also a good measure of disturbances associated with brain disorders. In this review, we appraise the current literature on cortical excitability studies using TMS in neurological disorders. We begin with a brief overview of current TMS measures and then show how these have added to our understanding of the underlying mechanisms of brain disorders. PMID:23402674

Effect of chronic and acute low-frequency repetitive transcranial magnetic stimulation on spatial memory in rats.

PubMed

Li, Wei; Yang, Yuye; Ye, Qing; Yang, Bo; Wang, Zhengrong

2007-03-15

Repetitive transcranial magnetic stimulation (rTMS) is a novel, non-invasive neurological and psychiatric tool. The low-frequency (1 Hz or less) rTMS is likely to play a particular role in its mechanism of action with different effects in comparison with high-frequency (>1 Hz) rTMS. There is limited information regarding the effect of low-frequency rTMS on spatial memory. In our study, each male Wistar rat was daily given 300 stimuli (1.0 T, 200 micros) at a rate of 0.5 Hz or sham stimulation. We investigated the effects of chronic and acute rTMS on reference/working memory process in Morris water maze test with the hypothesis that the effect would differ by chronic or acute condition. Chronic low-frequency rTMS impaired the retrieval of spatial short- and long-term spatial reference memory but not acquisition process and working memory, whereas acute low-frequency rTMS predominantly induced no deficits in acquisition or short-term spatial reference memory as well as working memory except for long-term reference memory. In summary, chronic 0.5 Hz rTMS disrupts spatial short- and long-term reference memory function, but acute rTMS differently affects reference memory. Chronic low-frequency rTMS may be used to modulate reference memory. Treatment protocols using low-frequency rTMS in neurological and psychiatric disorders need to take into account the potential effect of chronic low-frequency rTMS on memory and other cognitive functions.

Adaptability and reproducibility of a memory disruption rTMS protocol in the PharmaCog IMI European project.

PubMed

Martin-Trias, Pablo; Lanteaume, Laura; Solana, Elisabeth; Cassé-Perrot, Catherine; Fernández-Cabello, Sara; Babiloni, Claudio; Marzano, Nicola; Junqué, Carme; Rossini, Paolo Maria; Micallef, Joëlle; Truillet, Romain; Charles, Estelle; Jouve, Elisabeth; Bordet, Régis; Santamaria, Joan; Jovicich, Jorge; Rossi, Simone; Pascual-Leone, Alvaro; Blin, Olivier; Richardson, Jill; Bartrés-Faz, David

2018-06-19

Transcranial magnetic stimulation (TMS) can interfere with cognitive processes, such as transiently impairing memory. As part of a multi-center European project, we investigated the adaptability and reproducibility of a previously published TMS memory interfering protocol in two centers using EEG or fMRI scenarios. Participants were invited to attend three experimental sessions on different days, with sham repetitive TMS (rTMS) applied on day 1 and real rTMS on days 2 and 3. Sixty-eight healthy young men were included. On each experimental day, volunteers were instructed to remember visual pictures while receiving neuronavigated rTMS trains (20 Hz, 900 ms) during picture encoding at the left dorsolateral prefrontal cortex (L-DLPFC) and the vertex. Mixed ANOVA model analyses were performed. rTMS to the L-DLPFC significantly disrupted recognition memory on experimental day 2. No differences were found between centers or between fMRI and EEG recordings. Subjects with lower baseline memory performances were more susceptible to TMS disruption. No stability of TMS-induced memory interference could be demonstrated on day 3. Our data suggests that adapted cognitive rTMS protocols can be implemented in multi-center studies incorporating standardized experimental procedures. However, our center and modality effects analyses lacked sufficient statistical power, hence highlighting the need to conduct further studies with larger samples. In addition, inter and intra-subject variability in response to TMS might limit its application in crossover or longitudinal studies.

Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex reduces resting-state insula activity and modulates functional connectivity of the orbitofrontal cortex in cigarette smokers.

PubMed

Li, Xingbao; Du, Lian; Sahlem, Gregory L; Badran, Bashar W; Henderson, Scott; George, Mark S

2017-05-01

Previous studies reported that repetitive transcranial magnetic stimulation (rTMS) can reduce cue-elicited craving and decrease cigarette consumption in smokers. The mechanism of this effect however, remains unclear. We used resting-state functional magnetic resonance imaging (rsfMRI) to test the effect of rTMS in non-treatment seeking smokers. We used a single blinded, sham-controlled, randomized counterbalanced crossover design where participants underwent two visits separated by at least 1 week. Participants received active rTMS over the left dorsolateral prefrontal cortex (DLPFC) during one of their visits, and sham rTMS during their other visit. They had two rsFMRI scans before and after each rTMS session. We used the same rTMS stimulation parameters as in a previous study (10Hz, 5s-on, 10s-off, 100% resting motor threshold, 3000 pulses). Ten non-treatment-seeking, nicotine-dependent, cigarette smokers (6 women, an average age of 39.72 and an average cigarette per day of 17.30) finished the study. rsFMRI results demonstrate that as compared to a single session of sham rTMS, a single session of active rTMS inhibits brain activity in the right insula and thalamus in fractional amplitude of low frequency fluctuation (fALFF). For intrinsic brain connectivity comparisons, active TMS resulted in significantly decreased connectivity from the site of rTMS to the left orbitomedial prefrontal cortex. This data suggests that one session of rTMS can reduce activity in the right insula and right thalamus as measured by fALFF. The data also demonstrates that rTMS can reduce rsFC between the left DLPFC and the medial orbitofrontal cortex. Copyright © 2017 Elsevier B.V. All rights reserved.

A review of the efficacy of transcranial magnetic stimulation (TMS) treatment for depression, and current and future strategies to optimize efficacy.

PubMed

Loo, Colleen K; Mitchell, Philip B

2005-11-01

There is a growing interest in extending the use of repetitive transcranial magnetic stimulation (rTMS) beyond research centres to the widespread clinical treatment of depression. Thus it is timely to critically review the evidence for the efficacy of rTMS as an antidepressant treatment. Factors relevant to the efficacy of rTMS are discussed along with the implications of these for the further optimization of rTMS. Clinical trials of the efficacy of rTMS in depressed subjects are summarized and reviewed, focusing mainly on sham-controlled studies and meta-analyses published to date. There is a fairly consistent statistical evidence for the superiority of rTMS over a sham control, though the degree of clinical improvement is not large. However, this data is derived mainly from two-week comparisons of rTMS versus sham, and evidence suggests greater efficacy with longer treatment courses. Studies so far have also varied greatly in approaches to rTMS stimulation (with respect to stimulation site, stimulus parameters etc) with little empirical evidence to inform on the relative merits of these approaches. Only studies published in English were reviewed. Many of the studies in the literature had small sample sizes and different methodologies, making comparisons between studies difficult. Current published studies and meta-analyses have evaluated the efficacy of rTMS as given in treatment paradigms that are almost certainly suboptimal (e.g of two weeks' duration). While the data nevertheless supports positive outcomes for rTMS, there is much scope for the further refinement and development of rTMS as an antidepressant treatment. Ongoing research is critical for optimizing the efficacy of rTMS.

Solving the Orientation Specific Constraints in Transcranial Magnetic Stimulation by Rotating Fields

PubMed Central

Neef, Nicole E.; Agudelo-Toro, Andres; Rakhmilevitch, David; Paulus, Walter; Moses, Elisha

2014-01-01

Transcranial Magnetic Stimulation (TMS) is a promising technology for both neurology and psychiatry. Positive treatment outcome has been reported, for instance in double blind, multi-center studies on depression. Nonetheless, the application of TMS towards studying and treating brain disorders is still limited by inter-subject variability and lack of model systems accessible to TMS. The latter are required to obtain a deeper understanding of the biophysical foundations of TMS so that the stimulus protocol can be optimized for maximal brain response, while inter-subject variability hinders precise and reliable delivery of stimuli across subjects. Recent studies showed that both of these limitations are in part due to the angular sensitivity of TMS. Thus, a technique that would eradicate the need for precise angular orientation of the coil would improve both the inter-subject reliability of TMS and its effectiveness in model systems. We show here how rotation of the stimulating field relieves the angular sensitivity of TMS and provides improvements in both issues. Field rotation is attained by superposing the fields of two coils positioned orthogonal to each other and operated with a relative phase shift in time. Rotating field TMS (rfTMS) efficiently stimulates both cultured hippocampal networks and rat motor cortex, two neuronal systems that are notoriously difficult to excite magnetically. This opens the possibility of pharmacological and invasive TMS experiments in these model systems. Application of rfTMS to human subjects overcomes the orientation dependence of standard TMS. Thus, rfTMS yields optimal targeting of brain regions where correct orientation cannot be determined (e.g., via motor feedback) and will enable stimulation in brain regions where a preferred axonal orientation does not exist. PMID:24505266

Transcranial magnetic stimulation-induced global propagation of transient phase resetting associated with directional information flow.

PubMed

Kawasaki, Masahiro; Uno, Yutaka; Mori, Jumpei; Kobata, Kenji; Kitajo, Keiichi

2014-01-01

Electroencephalogram (EEG) phase synchronization analyses can reveal large-scale communication between distant brain areas. However, it is not possible to identify the directional information flow between distant areas using conventional phase synchronization analyses. In the present study, we applied transcranial magnetic stimulation (TMS) to the occipital area in subjects who were resting with their eyes closed, and analyzed the spatial propagation of transient TMS-induced phase resetting by using the transfer entropy (TE), to quantify the causal and directional flow of information. The time-frequency EEG analysis indicated that the theta (5 Hz) phase locking factor (PLF) reached its highest value at the distant area (the motor area in this study), with a time lag that followed the peak of the transient PLF enhancements of the TMS-targeted area at the TMS onset. Phase-preservation index (PPI) analyses demonstrated significant phase resetting at the TMS-targeted area and distant area. Moreover, the TE from the TMS-targeted area to the distant area increased clearly during the delay that followed TMS onset. Interestingly, the time lags were almost coincident between the PLF and TE results (152 vs. 165 ms), which provides strong evidence that the emergence of the delayed PLF reflects the causal information flow. Such tendencies were observed only in the higher-intensity TMS condition, and not in the lower-intensity or sham TMS conditions. Thus, TMS may manipulate large-scale causal relationships between brain areas in an intensity-dependent manner. We demonstrated that single-pulse TMS modulated global phase dynamics and directional information flow among synchronized brain networks. Therefore, our results suggest that single-pulse TMS can manipulate both incoming and outgoing information in the TMS-targeted area associated with functional changes.

Development of Wearable Sheet-Type Shear Force Sensor and Measurement System that is Insusceptible to Temperature and Pressure.

PubMed

Toyama, Shigeru; Tanaka, Yasuhiro; Shirogane, Satoshi; Nakamura, Takashi; Umino, Tokio; Uehara, Ryo; Okamoto, Takuma; Igarashi, Hiroshi

2017-07-31

A sheet-type shear force sensor and a measurement system for the sensor were developed. The sensor has an original structure where a liquid electrolyte is filled in a space composed of two electrode-patterned polymer films and an elastic rubber ring. When a shear force is applied on the surface of the sensor, the two electrode-patterned films mutually move so that the distance between the internal electrodes of the sensor changes, resulting in current increase or decrease between the electrodes. Therefore, the shear force can be calculated by monitoring the current between the electrodes. Moreover, it is possible to measure two-dimensional shear force given that the sensor has multiple electrodes. The diameter and thickness of the sensor head were 10 mm and 0.7 mm, respectively. Additionally, we also developed a measurement system that drives the sensor, corrects the baseline of the raw sensor output, displays data, and stores data as a computer file. Though the raw sensor output was considerably affected by the surrounding temperature, the influence of temperature was drastically decreased by introducing a simple arithmetical calculation. Moreover, the influence of pressure simultaneously decreased after the same calculation process. A demonstrative measurement using the sensor revealed the practical usefulness for on-site monitoring.

Role of TMS1 Silencing in the Resistance of Breast Cancer Cells to Apoptosis

DTIC Science & Technology

2006-08-01

USA 93: Kelliher MA, Grimm S, Ishida Y, Kuo F , Stanger BZ, Leder 14486-14491. P. (1998). Immunity 8: 297-303. Stehlik C , Fiorentino L , Dorfleutner A ...Caspase-8 - TMS1.. -. - GAPDH - . B. CuX+ siRNA: CHX TRAIL Lamin A / C + - + - TMS1 + - + Procaspase-8 f t Cleaved Caspase-8 - - 3 TMS1 . 03-tubulin...analysis for caspase-8, TMS 1 and either GAPDH or P3-tubulin as indicated. siRNA: Lamin A / C TMS1 TNFa+CHX - +- - + TRAIL -+ - + PARP -m l PARP p85

Added value of multiple versus single sessions of repetitive transcranial magnetic stimulation in predicting motor cortex stimulation efficacy for refractory neuropathic pain.

PubMed

Pommier, Benjamin; Quesada, Charles; Fauchon, Camille; Nuti, Christophe; Vassal, François; Peyron, Roland

2018-05-18

OBJECTIVE Selection criteria for offering patients motor cortex stimulation (MCS) for refractory neuropathic pain are a critical topic of research. A single session of repetitive transcranial magnetic stimulation (rTMS) has been advocated for selecting MCS candidates, but it has a low negative predictive value. Here the authors investigated whether multiple rTMS sessions would more accurately predict MCS efficacy. METHODS Patients included in this longitudinal study could access MCS after at least four rTMS sessions performed 3-4 weeks apart. The positive (PPV) and negative (NPV) predictive values of the four rTMS sessions and the correlation between the analgesic effects of the two treatments were assessed. RESULTS Twelve MCS patients underwent an average of 15.9 rTMS sessions prior to surgery; nine of the patients were rTMS responders. Postoperative follow-up was 57.8 ± 15.6 months (mean ± standard deviation). Mean percentage of pain relief (%R) was 21% and 40% after the first and fourth rTMS sessions, respectively. The corresponding mean durations of pain relief were respectively 2.4 and 12.9 days. A cumulative effect of the rTMS sessions was observed on both %R and duration of pain relief (p < 0.01). The %R value obtained with MCS was 35% after 6 months and 43% at the last follow-up. Both the PPV and NPV of rTMS were 100% after the fourth rTMS session (p = 0.0045). A significant correlation was found between %R or duration of pain relief after the fourth rTMS session and %R at the last MCS follow-up (R 2 = 0.83, p = 0.0003). CONCLUSIONS Four rTMS sessions predicted MCS efficacy better than a single session in neuropathic pain patients. Taking into account the cumulative effects of rTMS, the authors found a high-level correlation between the analgesic effects of rTMS and MCS.

Construction and Evaluation of Rodent-Specific rTMS Coils.

PubMed

Tang, Alexander D; Lowe, Andrea S; Garrett, Andrew R; Woodward, Robert; Bennett, William; Canty, Alison J; Garry, Michael I; Hinder, Mark R; Summers, Jeffery J; Gersner, Roman; Rotenberg, Alexander; Thickbroom, Gary; Walton, Joseph; Rodger, Jennifer

2016-01-01

Rodent models of transcranial magnetic stimulation (TMS) play a crucial role in aiding the understanding of the cellular and molecular mechanisms underlying TMS induced plasticity. Rodent-specific TMS have previously been used to deliver focal stimulation at the cost of stimulus intensity (12 mT). Here we describe two novel TMS coils designed to deliver repetitive TMS (rTMS) at greater stimulation intensities whilst maintaining spatial resolution. Two circular coils (8 mm outer diameter) were constructed with either an air or pure iron-core. Peak magnetic field strength for the air and iron-cores were 90 and 120 mT, respectively, with the iron-core coil exhibiting less focality. Coil temperature and magnetic field stability for the two coils undergoing rTMS, were similar at 1 Hz but varied at 10 Hz. Finite element modeling of 10 Hz rTMS with the iron-core in a simplified rat brain model suggests a peak electric field of 85 and 12.7 V/m, within the skull and the brain, respectively. Delivering 10 Hz rTMS to the motor cortex of anaesthetized rats with the iron-core coil significantly increased motor evoked potential amplitudes immediately after stimulation (n = 4). Our results suggest these novel coils generate modest magnetic and electric fields, capable of altering cortical excitability and provide an alternative method to investigate the mechanisms underlying rTMS-induced plasticity in an experimental setting.

Effects of prefrontal rTMS on autonomic reactions to affective pictures.

PubMed

Berger, Christoph; Domes, Gregor; Balschat, Johannes; Thome, Johannes; Höppner, Jacqueline

2017-02-01

Repetitive transcranial magnetic stimulation (rTMS) can modulate the excitability of stimulated cortical areas, such as prefrontal areas involved in emotion regulation. Low frequency (LF) rTMS is expected to have inhibitory effects on prefrontal regions, and thereby should disinhibit limbic activity, resulting in enhanced emotional and autonomic reactions. For high frequency (HF) rTMS, the opposite pattern might be assumed. The objective of this study was to determine the effects of different rTMS frequencies applied to the right dlPFC on autonomic functions and on emotional perception. In a crossover design, two groups of 20 healthy young women were either stimulated with one session of LF rTMS (1 Hz) or one session of HF rTMS (10 Hz), compared to sham stimulation. We assessed phasic cardiac responses (PCR), skin conductance reactions (SCR), and emotional appraisal of emotional pictures as well as recognition memory after each rTMS application. After LF rTMS, PCR (heart rate deceleration) during presentation of pictures with negative and neutral valence was significantly increased compared to the presentation of positive pictures. In contrast, the modulatory effect of picture valence and arousal on the cardiac orienting response was absent after HF rTMS. Our results suggest that frontal LF rTMS indirectly activates the ANS via inhibition of the right dlPFC activity, likely by enhancing the sensory processing or attention to aversive and neutral stimuli.

Overt Naming fMRI Pre- and Post- TMS: Two Nonfluent Aphasia Patients, with and without Improved Naming Post- TMS

PubMed Central

Martin, Paula I; Naeser, Margaret A.; Ho, Michael; Doron, Karl W.; Kurland, Jacquie; Kaplan, Jerome; Wang, Yunyan; Nicholas, Marjorie; Baker, Errol H.; Alonso, Miguel; Fregni, Felipe; Pascual-Leone, Alvaro

2009-01-01

Two chronic, nonfluent aphasia patients participated in overt naming fMRI scans, pre- and post- a series of repetitive transcranial magnetic stimulation (rTMS) treatments as part of a TMS study to improve naming. Each patient received ten, 1-Hz rTMS treatments to suppress a part of R pars triangularis. P1 was a ‘good responder’ with improved naming and phrase length; P2 was a ‘poor responder’ without improved naming. Pre- TMS (10 yr. poststroke), P1 had significant activation in R and L sensorimotor cortex, R IFG, and in both L and R SMA during overt naming fMRI (28% pictures named. At 3 mo. post- TMS (42% named), P1 showed continued activation in R and L sensorimotor cortex, R IFG, and in R and L SMA. At 16 mo. post- TMS (58% named), he also showed significant activation in R and L sensorimotor cortex mouth and R IFG. He now showed a significant increase in activation in the L SMA compared to pre- TMS and at 3 mo. post- TMS (p<.02; p<.05, respectively). At 16 mo. there was also greater activation in L than R SMA (p<.08). At 46 mo. post- TMS (42% named), this new LH pattern of activation continued. He improved on the Boston Naming Test from 11 pictures named pre- TMS, to scores ranging from 14-18 pictures, post- TMS (2 mo. to 43 mo. post- TMS). His longest phrase length (Cookie Theft picture) improved from 3 words pre- TMS, to 5-6 words post- TMS. Pre- TMS (1.5 yr. poststroke), P2 had significant activation in R IFG (3% pictures named). At 3 and 6 mo. post- TMS, there was no longer significant activation in R IFG, but significant activation was present in R sensorimotor cortex. On all three fMRI scans, P2 had significant activation in both the L and R SMA. There was no new, lasting perilesional LH activation across sessions for this patient. Over time, there was little or no change in his activation. His naming remained only at 1-2 pictures during all three fMRI scans. His BNT score and longest phrase length remained at 1 word, post- TMS. Lesion site may play a role in each patient’s fMRI activation pattern and response to TMS treatment. P2, the poor responder, had an atypical frontal lesion in the L motor and premotor cortex that extended high, near brain vertex, with deep white matter lesion near L SMA. P2 also had frontal lesion in the posterior middle frontal gyrus, an area important for naming (Duffau et al., 2003); P1 did not. Additionally, P2 had lesion inferior and posterior to Wernicke’s area, in parts of BA 21 and 37, whereas P1 did not. The fMRI data of our patient who had good response following TMS support the notion that restoration of the LH language network is linked in part, to better recovery of naming and phrase length in nonfluent aphasia. PMID:19695692

Overt naming fMRI pre- and post-TMS: Two nonfluent aphasia patients, with and without improved naming post-TMS.

PubMed

Martin, Paula I; Naeser, Margaret A; Ho, Michael; Doron, Karl W; Kurland, Jacquie; Kaplan, Jerome; Wang, Yunyan; Nicholas, Marjorie; Baker, Errol H; Alonso, Miguel; Fregni, Felipe; Pascual-Leone, Alvaro

2009-10-01

Two chronic, nonfluent aphasia patients participated in overt naming fMRI scans, pre- and post-a series of repetitive transcranial magnetic stimulation (rTMS) treatments as part of a TMS study to improve naming. Each patient received 10, 1-Hz rTMS treatments to suppress a part of R pars triangularis. P1 was a 'good responder' with improved naming and phrase length; P2 was a 'poor responder' without improved naming. Pre-TMS (10 years poststroke), P1 had significant activation in R and L sensorimotor cortex, R IFG, and in both L and R SMA during overt naming fMRI (28% pictures named). At 3 mo. post-TMS (42% named), P1 showed continued activation in R and L sensorimotor cortex, R IFG, and in R and L SMA. At 16 mo. post-TMS (58% named), he also showed significant activation in R and L sensorimotor cortex mouth and R IFG. He now showed a significant increase in activation in the L SMA compared to pre-TMS and at 3 mo. post-TMS (p < .02; p < .05, respectively). At 16 mo. there was also greater activation in L than R SMA (p < .08). At 46 mo. post-TMS (42% named), this new LH pattern of activation continued. He improved on the Boston Naming Test from 11 pictures named pre-TMS, to scores ranging from 14 to 18 pictures, post-TMS (2-43 mo. post-TMS). His longest phrase length (Cookie Theft picture) improved from three words pre-TMS, to 5-6 words post-TMS. Pre-TMS (1.5 years poststroke), P2 had significant activation in R IFG (3% pictures named). At 3 and 6 mo. post-TMS, there was no longer significant activation in R IFG, but significant activation was present in R sensorimotor cortex. On all three fMRI scans, P2 had significant activation in both the L and R SMA. There was no new, lasting perilesional LH activation across sessions for this patient. Over time, there was little or no change in his activation. His naming remained only at 1-2 pictures during all three fMRI scans. His BNT score and longest phrase length remained at one word, post-TMS. Lesion site may play a role in each patient's fMRI activation pattern and response to TMS treatment. P2, the poor responder, had an atypical frontal lesion in the L motor and premotor cortex that extended high, near brain vertex, with deep white matter lesion near L SMA. P2 also had frontal lesion in the posterior middle frontal gyrus, an area important for naming (Duffau et al., 2003); P1 did not. Additionally, P2 had lesion inferior and posterior to Wernicke's area, in parts of BA 21 and 37, whereas P1 did not. The fMRI data of our patient who had good response following TMS support the notion that restoration of the LH language network is linked in part, to better recovery of naming and phrase length in nonfluent aphasia.

Short-term and long-term plasticity interaction in human primary motor cortex.

PubMed

Iezzi, Ennio; Suppa, Antonio; Conte, Antonella; Li Voti, Pietro; Bologna, Matteo; Berardelli, Alfredo

2011-05-01

Repetitive transcranial magnetic stimulation (rTMS) over primary motor cortex (M1) elicits changes in motor evoked potential (MEP) size thought to reflect short- and long-term forms of synaptic plasticity, resembling short-term potentiation (STP) and long-term potentiation/depression (LTP/LTD) observed in animal experiments. We designed this study in healthy humans to investigate whether STP as elicited by 5-Hz rTMS interferes with LTP/LTD-like plasticity induced by intermittent and continuous theta-burst stimulation (iTBS and cTBS). The effects induced by 5-Hz rTMS and iTBS/cTBS were indexed as changes in MEP size. We separately evaluated changes induced by 5-Hz rTMS, iTBS and cTBS applied alone and those induced by iTBS and cTBS delivered after priming 5-Hz rTMS. Interactions between 5-Hz rTMS and iTBS/cTBS were investigated under several experimental conditions by delivering 5-Hz rTMS at suprathreshold and subthreshold intensity, allowing 1 and 5 min intervals to elapse between 5-Hz rTMS and TBS, and delivering one and ten 5-Hz rTMS trains. We also investigated whether 5-Hz rTMS induces changes in intracortical excitability tested with paired-pulse transcranial magnetic stimulation. When given alone, 5-Hz rTMS induced short-lasting and iTBS/cTBS induced long-lasting changes in MEP amplitudes. When M1 was primed with 10 suprathreshold 5-Hz rTMS trains at 1 min before iTBS or cTBS, the iTBS/cTBS-induced after-effects disappeared. The 5-Hz rTMS left intracortical excitability unchanged. We suggest that STP elicited by suprathreshold 5-Hz rTMS abolishes iTBS/cTBS-induced LTP/LTD-like plasticity through non-homeostatic metaplasticity mechanisms. Our study provides new information on interactions between short-term and long-term rTMS-induced plasticity in human M1. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Controllable pulse parameter transcranial magnetic stimulator with enhanced circuit topology and pulse shaping

NASA Astrophysics Data System (ADS)

Peterchev, Angel V.; DʼOstilio, Kevin; Rothwell, John C.; Murphy, David L.

2014-10-01

Objective. This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. Approach. We present a third generation controllable pulse parameter device (cTMS3) that uses a novel circuit topology with two energy-storage capacitors. It incorporates several implementation and functionality advantages over conventional TMS devices and other devices with advanced pulse shape control. cTMS3 generates lower internal voltage differences and is implemented with transistors with a lower voltage rating than prior cTMS devices. Main results. cTMS3 provides more flexible pulse shaping since the circuit topology allows four coil-voltage levels during a pulse, including approximately zero voltage. The near-zero coil voltage enables snubbing of the ringing at the end of the pulse without the need for a separate active snubber circuit. cTMS3 can generate powerful rapid pulse sequences (\\lt 10 ms inter pulse interval) by increasing the width of each subsequent pulse and utilizing the large capacitor energy storage, allowing the implementation of paradigms such as paired-pulse and quadripulse TMS with a single pulse generation circuit. cTMS3 can also generate theta (50 Hz) burst stimulation with predominantly unidirectional electric field pulses. The cTMS3 device functionality and output strength are illustrated with electrical output measurements as well as a study of the effect of pulse width and polarity on the active motor threshold in ten healthy volunteers. Significance. The cTMS3 features could extend the utility of TMS as a research, diagnostic, and therapeutic tool.

What does low-intensity rTMS do to the cerebellum?

PubMed

Morellini, N; Grehl, S; Tang, A; Rodger, J; Mariani, J; Lohof, A M; Sherrard, R M

2015-02-01

Non-invasive stimulation of the human cerebellum, such as by transcranial magnetic stimulation (TMS), is increasingly used to investigate cerebellar function and identify potential treatment for cerebellar dysfunction. However, the effects of TMS on cerebellar neurons remain poorly defined. We applied low-intensity repetitive TMS (LI-rTMS) to the mouse cerebellum in vivo and in vitro and examined the cellular and molecular sequelae. In normal C57/Bl6 mice, 4 weeks of LI-rTMS using a complex biomimetic high-frequency stimulation (BHFS) alters Purkinje cell (PC) dendritic and spine morphology; the effects persist 4 weeks after the end of stimulation. We then evaluated whether LI-rTMS could induce climbing fibre (CF) reinnervation to denervated PCs. After unilateral pedunculotomy in adult mice and 2 weeks sham or BHFS stimulation, VGLUT2 immunohistochemistry was used to quantify CF reinnervation. In contrast to sham, LI-rTMS induced CF reinnervation to the denervated hemicerebellum. To examine potential mechanisms underlying the LI-rTMS effect, we verified that BHFS could induce CF reinnervation using our in vitro olivocerebellar explants in which denervated cerebellar tissue is co-cultured adjacent to intact cerebella and treated with brain-derived neurotrophic factor (BDNF) (as a positive control), sham or LI-rTMS for 2 weeks. Compared with sham, BDNF and BHFS LI-rTMS significantly increased CF reinnervation, without additive effect. To identify potential underlying mechanisms, we examined intracellular calcium flux during the 10-min stimulation. Complex high-frequency stimulation increased intracellular calcium by release from intracellular stores. Thus, even at low intensity, rTMS modifies PC structure and induces CF reinnervation.

A novel approach for documenting naming errors induced by navigated transcranial magnetic stimulation.

PubMed

Lioumis, Pantelis; Zhdanov, Andrey; Mäkelä, Niko; Lehtinen, Henri; Wilenius, Juha; Neuvonen, Tuomas; Hannula, Henri; Deletis, Vedran; Picht, Thomas; Mäkelä, Jyrki P

2012-03-15

Transcranial magnetic stimulation (TMS) is widely used both in basic research and in clinical practice. TMS has been utilized in studies of functional organization of speech in healthy volunteers. Navigated TMS (nTMS) allows preoperative mapping of the motor cortex for surgical planning. Recording behavioral responses to nTMS in the speech-related cortical network in a manner that allows off-line review of performance might increase utility of nTMS both for scientific and clinical purposes, e.g., for a careful preoperative planning. Four subjects participated in the study. The subjects named pictures of objects presented every 2-3s on a computer screen. One-second trains of 5 pulses were applied by nTMS 300ms after the presentation of pictures. The nTMS and stimulus presentation screens were cloned. A commercial digital camera was utilized to record the subject's performance and the screen clones. Delays between presentation, audio and video signals were eliminated by carefully tested combination of displays and camera. An experienced neuropsychologist studied the videos and classified the errors evoked by nTMS during the object naming. Complete anomias, semantic, phonological and performance errors were observed during nTMS of left fronto-parieto-temporal cortical regions. Several errors were detected only in the video classification. nTMS combined with synchronized video recording provides an accurate monitoring tool of behavioral TMS experiments. This experimental setup can be particularly useful for high-quality cognitive paradigms and for clinical purposes. Copyright © 2011 Elsevier B.V. All rights reserved.

Controllable pulse parameter transcranial magnetic stimulator with enhanced circuit topology and pulse shaping

PubMed Central

D’Ostilio, Kevin; Rothwell, John C; Murphy, David L

2014-01-01

Objective This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. Approach We present a third generation controllable pulse parameter device (cTMS3) that uses a novel circuit topology with two energy-storage capacitors. It incorporates several implementation and functionality advantages over conventional TMS devices and other devices with advanced pulse shape control. cTMS3 generates lower internal voltage differences and is implemented with transistors with lower voltage rating than prior cTMS devices. Main results cTMS3 provides more flexible pulse shaping since the circuit topology allows four coil-voltage levels during a pulse, including approximately zero voltage. The near-zero coil voltage enables snubbing of the ringing at the end of the pulse without the need for a separate active snubber circuit. cTMS3 can generate powerful rapid pulse sequences (<10 ms inter pulse interval) by increasing the width of each subsequent pulse and utilizing the large capacitor energy storage, allowing the implementation of paradigms such as paired-pulse and quadripulse TMS with a single pulse generation circuit. cTMS3 can also generate theta (50 Hz) burst stimulation with predominantly unidirectional electric field pulses. The cTMS3 device functionality and output strength are illustrated with electrical output measurements as well as a study of the effect of pulse width and polarity on the active motor threshold in 10 healthy volunteers. Significance The cTMS3 features could extend the utility of TMS as a research, diagnostic, and therapeutic tool. PMID:25242286

Language Mapping with Navigated Repetitive TMS: Proof of Technique and Validation

PubMed Central

Tarapore, Phiroz E.; Findlay, Anne M.; Honma, Susanne M.; Mizuiri, Danielle; Houde, John F.; Berger, Mitchel S.; Nagarajan, Srikantan S.

2013-01-01

Objective Lesion-based mapping of speech pathways has been possible only during invasive neurosurgical procedures using direct cortical stimulation (DCS). However, navigated transcranial magnetic stimulation (nTMS) may allow for lesion-based interrogation of language pathways noninvasively. Although not lesion-based, magnetoencephalographic imaging (MEGI) is another noninvasive modality for language mapping. In this study, we compare the accuracy of nTMS and MEGI with DCS. Methods Subjects with lesions around cortical language areas underwent preoperative nTMS and MEGI for language mapping. nTMS maps were generated using a repetitive TMS protocol to deliver trains of stimulations during a picture naming task. MEGI activation maps were derived from adaptive spatial filtering of beta-band power decreases prior to overt speech during picture naming and verb generation tasks. The subjects subsequently underwent awake language mapping via intraoperative DCS. The language maps obtained from each of the 3 modalities were recorded and compared. Results nTMS and MEGI were performed on 12 subjects. nTMS yielded 21 positive language disruption sites (11 speech arrest, 5 anomia, and 5 other) while DCS yielded 10 positive sites (2 speech arrest, 5 anomia, and 3 other). MEGI isolated 32 sites of peak activation with language tasks. Positive language sites were most commonly found in the pars opercularis for all three modalities. In 9 instances the positive DCS site corresponded to a positive nTMS site, while in 1 instance it did not. In 4 instances, a positive nTMS site corresponded to a negative DCS site, while 169 instances of negative nTMS and DCS were recorded. The sensitivity of nTMS was therefore 90%, specificity was 98%, the positive predictive value was 69% and the negative predictive value was 99% as compared with intraoperative DCS. MEGI language sites for verb generation and object naming correlated with nTMS sites in 5 subjects, and with DCS sites in 2 subjects. Conclusion Maps of language function generated with nTMS correlate well with those generated by DCS. Negative nTMS mapping also correlates with negative DCS mapping. In our study, MEGI lacks the same level of correlation with intraoperative mapping; nevertheless it provides useful adjunct information in some cases. nTMS may offer a lesion-based method for noninvasively interrogating language pathways and be valuable in managing patients with peri-eloquent lesions. PMID:23702420

Frontal Non-Invasive Neurostimulation Modulates Antisaccade Preparation in Non-Human Primates

PubMed Central

Valero-Cabre, Antoni; Wattiez, Nicolas; Monfort, Morgane; François, Chantal; Rivaud-Péchoux, Sophie; Gaymard, Bertrand; Pouget, Pierre

2012-01-01

A combination of oculometric measurements, invasive electrophysiological recordings and microstimulation have proven instrumental to study the role of the Frontal Eye Field (FEF) in saccadic activity. We hereby gauged the ability of a non-invasive neurostimulation technology, Transcranial Magnetic Stimulation (TMS), to causally interfere with frontal activity in two macaque rhesus monkeys trained to perform a saccadic antisaccade task. We show that online single pulse TMS significantly modulated antisaccade latencies. Such effects proved dependent on TMS site (effects on FEF but not on an actively stimulated control site), TMS modality (present under active but not sham TMS on the FEF area), TMS intensity (intensities of at least 40% of the TMS machine maximal output required), TMS timing (more robust for pulses delivered at 150 ms than at 100 post target onset) and visual hemifield (relative latency decreases mainly for ipsilateral AS). Our results demonstrate the feasibility of using TMS to causally modulate antisaccade-associated computations in the non-human primate brain and support the use of this approach in monkeys to study brain function and its non-invasive neuromodulation for exploratory and therapeutic purposes. PMID:22701691

rTMS strategies for the study and treatment of schizophrenia: a review

PubMed Central

Stanford, Arielle D.; Sharif, Zafar; Corcoran, Cheryl; Urban, Nina; Malaspina, Dolores; Lisanby, Sarah H.

2010-01-01

Transcranial magnetic stimulation (TMS) and repetitive TMS (rTMS) have been used increasingly over the past few years to study both the pathophysiology of schizophrenia as well as the utility of focal neuromodulation as a novel treatment for schizophrenia. rTMS treatment studies to date have explored its effect on both positive and negative symptoms by targeting cortical regions thought to underlie these symptom clusters. Studies on auditory hallucinations have been largely positive, while efficacy for negative symptoms is equivocal. A better understanding of the functional abnormalities that accompany symptoms may facilitate the development of rTMS as a treatment modality. Furthermore, schizophrenia patients appear to have abnormal cortical inhibition, consistent with GABA and dopamine abnormalities in schizophrenia. The effect of TMS on GABA and dopamine neurotransmission has not been clearly delineated. Given the variability in cortical response to rTMS in schizophrenia, methods to optimize dosage are essential. Consideration of these factors among others may broaden the scope of utility of TMS for schizophrenia as well as enhance its efficacy. PMID:18241358

Treating Clinical Depression with Repetitive Deep Transcranial Magnetic Stimulation Using the Brainsway H1-coil.

PubMed

Feifel, David; Pappas, Katherine

2016-10-04

Repetitive transcranial magnetic stimulation (rTMS) is an emerging non-pharmacological approach to treating many brain-based disorders. rTMS uses electromagnetic coils to stimulate areas of the brain non-invasively. Deep transcranial magnetic stimulation (dTMS) with the Brainsway H1-coil system specifically is a type of rTMS indicated for treating patients with major depressive disorder (MDD) who are resistant to medication. The unique H1-coil design of this device is able to stimulate neuronal pathways that lie deeper in the targeted brain areas than those reached by conventional rTMS coils. dTMS is considered to be low-risk and well tolerated, making it a viable treatment option for people who have not responded to medication or psychotherapy trials for their depression. Randomized, sham-control studies have demonstrated that dTMS produces significantly greater improvement in depressive symptoms than sham dTMS treatment in patients with major depression that has not responded to antidepressant medication. In this paper, we will review the methodology for treating major depression with dTMS using an H1-coil.

Overt Naming fMRI Pre- and Post-TMS: Two Nonfluent Aphasia Patients, with and without Improved Naming Post-TMS

ERIC Educational Resources Information Center

Martin, Paula I.; Naeser, Margaret A.; Ho, Michael; Doron, Karl W.; Kurland, Jacquie; Kaplan, Jerome; Wang, Yunyan; Nicholas, Marjorie; Baker, Errol H.; Fregni, Felipe; Pascual-Leone, Alvaro

2009-01-01

Two chronic, nonfluent aphasia patients participated in overt naming fMRI scans, pre- and post-a series of repetitive transcranial magnetic stimulation (rTMS) treatments as part of a TMS study to improve naming. Each patient received 10, 1-Hz rTMS treatments to suppress a part of R pars triangularis. P1 was a "good responder" with improved naming…

Enhancing picture naming with transcranial magnetic stimulation.

PubMed

Mottaghy, Felix M; Sparing, Roland; Töpper, Rudolf

2006-01-01

The enhancement of cognitive function in healthy subjects by medication, training or intervention yields increasing political, social and ethical attention. In this paper facilitatory effects of single-pulse TMS and repetitive TMS on a simple picture naming task are presented. A significant shortening of picture naming latencies was observed after single-pulse TMS over Wernicke's area. The accuracy of the response was not affected by this speed effect. After TMS over the dominant motor cortex or over the non-dominant temporal lobe, however, no facilitation of picture naming was observed. In the rTMS experiments only rTMS of Wernicke's area had an impact on picture naming latencies resulting in a shortening of naming latencies without affecting the accuracy of the response. rTMS over the visual cortex, Broca's area or over the corresponding sites in the non-dominant hemisphere had no effect. Single-pulse TMS is able to facilitate lexical processes due to a general preactivation of language-related neuronal networks when delivered over Wernicke's area. Repetitive transcranial magnetic stimulation over Wernicke's area also leads to a brief facilitation of picture naming possibly by shortening linguistic processing time. Whether TMS or rTMS can be used to aid linguistic therapy in the rehabilitation phase of aphasic patients should be subject of further investigations.

On the feasibility of concurrent human TMS-EEG-fMRI measurements

PubMed Central

Reithler, Joel; Schuhmann, Teresa; de Graaf, Tom; Uludağ, Kâmil; Goebel, Rainer; Sack, Alexander T.

2013-01-01

Simultaneously combining the complementary assets of EEG, functional MRI (fMRI), and transcranial magnetic stimulation (TMS) within one experimental session provides synergetic results, offering insights into brain function that go beyond the scope of each method when used in isolation. The steady increase of concurrent EEG-fMRI, TMS-EEG, and TMS-fMRI studies further underlines the added value of such multimodal imaging approaches. Whereas concurrent EEG-fMRI enables monitoring of brain-wide network dynamics with high temporal and spatial resolution, the combination with TMS provides insights in causal interactions within these networks. Thus the simultaneous use of all three methods would allow studying fast, spatially accurate, and distributed causal interactions in the perturbed system and its functional relevance for intact behavior. Concurrent EEG-fMRI, TMS-EEG, and TMS-fMRI experiments are already technically challenging, and the three-way combination of TMS-EEG-fMRI might yield additional difficulties in terms of hardware strain or signal quality. The present study explored the feasibility of concurrent TMS-EEG-fMRI studies by performing safety and quality assurance tests based on phantom and human data combining existing commercially available hardware. Results revealed that combined TMS-EEG-fMRI measurements were technically feasible, safe in terms of induced temperature changes, allowed functional MRI acquisition with comparable image quality as during concurrent EEG-fMRI or TMS-fMRI, and provided artifact-free EEG before and from 300 ms after TMS pulse application. Based on these empirical findings, we discuss the conceptual benefits of this novel complementary approach to investigate the working human brain and list a number of precautions and caveats to be heeded when setting up such multimodal imaging facilities with current hardware. PMID:23221407

Effects of low frequency rTMS treatment on brain networks for inner speech in patients with schizophrenia and auditory verbal hallucinations.

PubMed

Bais, Leonie; Liemburg, Edith; Vercammen, Ans; Bruggeman, Richard; Knegtering, Henderikus; Aleman, André

2017-08-01

Efficacy of repetitive Transcranial Magnetic Stimulation (rTMS) targeting the temporo-parietal junction (TPJ) for the treatment of auditory verbal hallucinations (AVH) remains under debate. We assessed the influence of a 1Hz rTMS treatment on neural networks involved in a cognitive mechanism proposed to subserve AVH. Patients with schizophrenia (N=24) experiencing medication-resistant AVH completed a 10-day 1Hz rTMS treatment. Participants were randomized to active stimulation of the left or bilateral TPJ, or sham stimulation. The effects of rTMS on neural networks were investigated with an inner speech task during fMRI. Changes within and between neural networks were analyzed using Independent Component Analysis. rTMS of the left and bilateral TPJ areas resulted in a weaker network contribution of the left supramarginal gyrus to the bilateral fronto-temporal network. Left-sided rTMS resulted in stronger network contributions of the right superior temporal gyrus to the auditory-sensorimotor network, right inferior gyrus to the left fronto-parietal network, and left middle frontal gyrus to the default mode network. Bilateral rTMS was associated with a predominant inhibitory effect on network contribution. Sham stimulation showed different patterns of change compared to active rTMS. rTMS of the left temporo-parietal region decreased the contribution of the left supramarginal gyrus to the bilateral fronto-temporal network, which may reduce the likelihood of speech intrusions. On the other hand, left rTMS appeared to increase the contribution of functionally connected regions involved in perception, cognitive control and self-referential processing. These findings hint to potential neural mechanisms underlying rTMS for hallucinations but need corroboration in larger samples. Copyright © 2017 Elsevier Inc. All rights reserved.

Repetitive transcranial magnetic stimulation of the dorsolateral prefrontal cortex reduces nicotine cue craving.

PubMed

Li, Xingbao; Hartwell, Karen J; Owens, Max; Lematty, Todd; Borckardt, Jeffrey J; Hanlon, Colleen A; Brady, Kathleen T; George, Mark S

2013-04-15

Repetitive transcranial magnetic stimulation (rTMS) can noninvasively stimulate the brain and transiently amplify or block behaviors mediated through a region. We hypothesized that a single high-frequency rTMS session over the left dorsolateral prefrontal cortex (DLPFC) would reduce cue craving for cigarettes compared with a sham TMS session. Sixteen non-treatment-seeking, nicotine-dependent participants were randomized to receive either real high-frequency rTMS (10 Hz, 100% resting motor threshold, 5-sec on, 10-sec off for 15 min; 3000 pulses) or active sham (eSham) TMS over the DLPFC in two visits with 1 week between visits. The participants received cue exposure before and after rTMS and rated their craving after each block of cue presentation. Stimulation of the left DLFPC with real, but not sham, rTMS reduced craving significantly from baseline (64.1±5.9 vs. 45.7±6.4, t = 2.69, p = .018). When compared with neutral cue craving, the effect of real TMS on cue craving was significantly greater than the effect of sham TMS (12.5±10.4 vs. -9.1±10.4; t = 2.07, p = .049). More decreases in subjective craving induced by TMS correlated positively with higher Fagerström Test for Nicotine Dependence score (r = .58, p = .031) and more cigarettes smoked per day (r = .57, p = .035). One session of high-frequency rTMS (10 Hz) of the left DLPFC significantly reduced subjective craving induced by smoking cues in nicotine-dependent participants. Additional studies are needed to explore rTMS as an aid to smoking cessation. Copyright © 2013 Society of Biological Psychiatry. All rights reserved.

The use of transcranial magnetic stimulation to evaluate cortical excitability of lower limb musculature: Challenges and opportunities.

PubMed

Kesar, Trisha M; Stinear, James W; Wolf, Steven L

2018-05-05

Neuroplasticity is a fundamental yet relatively unexplored process that can impact rehabilitation of lower extremity (LE) movements. Transcranial magnetic stimulation (TMS) has gained widespread application as a non-invasive brain stimulation technique for evaluating neuroplasticity of the corticospinal pathway. However, a majority of TMS studies have been performed on hand muscles, with a paucity of TMS investigations focused on LE muscles. This perspective review paper proposes that there are unique methodological challenges associated with using TMS to evaluate corticospinal excitability of lower limb muscles. The challenges include: (1) the deeper location of the LE motor homunculus; (2) difficulty with targeting individual LE muscles during TMS; and (3) differences in corticospinal circuity controlling upper and lower limb muscles. We encourage future investigations that modify traditional methodological approaches to help address these challenges. Systematic TMS investigations are needed to determine the extent of overlap in corticomotor maps for different LE muscles. A simple, yet informative methodological solution involves simultaneous recordings from multiple LE muscles, which will provide the added benefit of observing how other relevant muscles co-vary in their responses during targeted TMS assessment directed toward a specific muscle. Furthermore, conventionally used TMS methods (e.g., determination of hot spot location and motor threshold) may need to be modified for TMS studies involving LE muscles. Additional investigations are necessary to determine the influence of testing posture as well as activation state of adjacent and distant LE muscles on TMS-elicited responses. An understanding of these challenges and solutions specific to LE TMS will improve the ability of neurorehabilitation clinicians to interpret TMS literature, and forge novel future directions for neuroscience research focused on elucidating neuroplasticity processes underlying locomotion and gait training.

Efficacy, Safety and Tolerability of Augmentative rTMS in Treatment of Major Depressive Disorder (MDD): A Prospective Cohort Study in Croatia.

PubMed

Filipcic, Igor; Milovac, Zeljko; Sucic, Strahimir; Gajsak, Tomislav; Filipcic, Ivona Simunovic; Ivezic, Ena; Aljinovic, Vjekoslav; Orgulan, Ivana; Penic, Sandra Zecevic; Bajic, Zarko

2017-03-01

An increasing body of research suggest that repetitive Transcranial Magnetic Stimulation (rTMS) is effective and safe treatment option for patients with major depressive disorder (MDD). The Psychiatric Hospital "Sveti Ivan" has the first TMS laboratory with rTMS and deep TMS (dTMS) in Croatia. The objective of this study was to assess the efficacy, safety and tolerability of augmentative rTMS treatment vs standard treatment in Croatian patients with major depressive disorder (MDD). Total of 93 MDD patients were enrolled; 41 of them were treated by augmentative rTMS and 52 were treated by standard (psychopharmacotherapy and psychotherapy) therapy only. We delivered rTMS to the left dorsolateral prefrontal cortex at 120% motor threshold (10 Hz, 4-second train duration), 3000 pulses per session using a figure-eight coil, minimum of 20 sessions during four weeks. Our key outcome was the change in Hamilton Depression Scale (HAM-D17) result from baseline to 4 th week. Our secondary outcomes were changes in Hamilton Anxiety (HAM-A) and WHOQOL-BREF scales. After four weeks the changes of HAM-D17 and HAM-A results were significantly different between the group of patients treated by augmentative rTMS (48% and 53% decrease, respectively) and the group of patients treated by the standard therapy alone (24% and 30% decrease) (P=0.004, P=0.007). Absolute benefit increase defined as the difference between rates of remission (HAM-D17 ≤7) in rTMS and control group was 33% (P=0.001). Number of patients needed to treat with rTMS in order to achieve remission in one patient was NNT=3. In a group of patients treated with augmentative rTMS 21/41 (51%), and in control group 17/52 (33%) were responders (P=0.071). It seems that augmentative treatment with rTMS is more effective on depression and anxiety symptoms than standard therapy in MDD with equal safety and tolerability. Randomized, controlled studies are required to verify this finding.

Academic Performance of Students with the Highest and Mediocre School-leaving Grades: Does the Aptitude Test for Medical Studies (TMS) Balance Their Prognoses?

PubMed Central

Kadmon, Guni; Kadmon, Martina

2016-01-01

Background: Admission to undergraduate medical training in Germany occurs by central and local pathways. Central admission includes two distinct groups: Students with top school-leaving grades (best-SLG group) and students with inferior school-leaving grades who are admitted with a delay of up to seven years (delayed admission group). Students with academic difficulties and early dropouts are present in both groups. Local admission at our university involves the German Test for Medical Studies (TMS) and allows the admission by merit of students with a wide range of school-leaving grades. Aims: To examine the justification of a TMS-based strategy to reduce the admission of potentially weak best school-leavers and enhance the admission of potentially able candidates with mediocre school-leaving grades. Method: The prognostic contribution of the school-leaving (SL) GPA and the TMS to academic performance and to continuity in the pre-clinical part of the undergraduate medical program was examined in two study groups: best school leavers (SL grade 1.0, SL-GPA 823-900 points) and mediocre school leavers (SL grades 2.0-2.3, SL-GPA 689-660 points). The outcomes in both groups were compared in relation to their TMS results. The prospective study included four consecutive cohorts. Results: In each study group the TMS predicted the academic performance (β=0.442-0.446) and the continuity of studies (OR=0.890-0.853) better than the SL-GPA (β=0.238-0.047; OR=1.009-0.998). Attrition was most strongly associated with failing to take the TMS (OR=0.230-0.380). Mediocre school leavers with TMS scores ≥125 performed as well as the best school leavers. Mediocre school leavers with TMS scores between 110-124 performed on average less well but within the required standards. Best school leavers with mediocre TMS scores and 30% of the best school leavers who hadn't taken the TMS performed less well than most mediocre school leavers with high TMS scores. Discussion: The TMS appears to differentiate between potentially successful and less successful students in both GPA categories. Mediocre school leavers (SLG 2.0-2.3) with exceptionally high TMS results reach better pre-clinical examination results than best school leavers (SLG 1.0) with mediocre TMS results. Thus, the present data justify the use of the TMS to facilitate the participation of mediocre school leavers in the competition for admission slots. PMID:26958655

Academic Performance of Students with the Highest and Mediocre School-leaving Grades: Does the Aptitude Test for Medical Studies (TMS) Balance Their Prognoses?

PubMed

Kadmon, Guni; Kadmon, Martina

2016-01-01

Admission to undergraduate medical training in Germany occurs by central and local pathways. Central admission includes two distinct groups: Students with top school-leaving grades (best-SLG group) and students with inferior school-leaving grades who are admitted with a delay of up to seven years (delayed admission group). Students with academic difficulties and early dropouts are present in both groups. Local admission at our university involves the German Test for Medical Studies (TMS) and allows the admission by merit of students with a wide range of school-leaving grades. To examine the justification of a TMS-based strategy to reduce the admission of potentially weak best school-leavers and enhance the admission of potentially able candidates with mediocre school-leaving grades. The prognostic contribution of the school-leaving (SL) GPA and the TMS to academic performance and to continuity in the pre-clinical part of the undergraduate medical program was examined in two study groups: best school leavers (SL grade 1.0, SL-GPA 823-900 points) and mediocre school leavers (SL grades 2.0-2.3, SL-GPA 689-660 points). The outcomes in both groups were compared in relation to their TMS results. The prospective study included four consecutive cohorts. In each study group the TMS predicted the academic performance (β=0.442-0.446) and the continuity of studies (OR=0.890-0.853) better than the SL-GPA (β=0.238-0.047; OR=1.009-0.998). Attrition was most strongly associated with failing to take the TMS (OR=0.230-0.380). Mediocre school leavers with TMS scores ≥125 performed as well as the best school leavers. Mediocre school leavers with TMS scores between 110-124 performed on average less well but within the required standards. Best school leavers with mediocre TMS scores and 30% of the best school leavers who hadn't taken the TMS performed less well than most mediocre school leavers with high TMS scores. The TMS appears to differentiate between potentially successful and less successful students in both GPA categories. Mediocre school leavers (SLG 2.0-2.3) with exceptionally high TMS results reach better pre-clinical examination results than best school leavers (SLG 1.0) with mediocre TMS results. Thus, the present data justify the use of the TMS to facilitate the participation of mediocre school leavers in the competition for admission slots.

A novel coil array for combined TMS/fMRI experiments at 3 T.

PubMed

Navarro de Lara, Lucia I; Windischberger, Christian; Kuehne, Andre; Woletz, Michael; Sieg, Jürgen; Bestmann, Sven; Weiskopf, Nikolaus; Strasser, Bernhard; Moser, Ewald; Laistler, Elmar

2015-11-01

To overcome current limitations in combined transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) studies by employing a dedicated coil array design for 3 Tesla. The state-of-the-art setup for concurrent TMS/fMRI is to use a large birdcage head coil, with the TMS between the subject's head and the MR coil. This setup has drawbacks in sensitivity, positioning, and available imaging techniques. In this study, an ultraslim 7-channel receive-only coil array for 3 T, which can be placed between the subject's head and the TMS, is presented. Interactions between the devices are investigated and the performance of the new setup is evaluated in comparison to the state-of-the-art setup. MR sensitivity obtained at the depth of the TMS stimulation is increased by a factor of five. Parallel imaging with an acceleration factor of two is feasible with low g-factors. Possible interactions between TMS and the novel hardware were investigated and were found negligible. The novel coil array is safe, strongly improves signal-to-noise ratio in concurrent TMS/fMRI experiments, enables parallel imaging, and allows for flexible positioning of the TMS on the head while ensuring efficient TMS stimulation due to its ultraslim design. © 2014 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

Actigraphy in Patients With Major Depressive Disorder Undergoing Repetitive Transcranial Magnetic Stimulation: An Open Label Pilot Study.

PubMed

Nishida, Masaki; Kikuchi, Senichiro; Nisijima, Koichi; Suda, Shiro

2017-03-01

The effects of repetitive transcranial magnetic stimulation (rTMS) on physical activity and sleep patterns in individuals with major depressive disorder (MDD) remain unclear. We examined the effects of rTMS treatment on the rest-activity cycle and sleep disturbances in MDD. In this open-label pilot study, 14 patients with medication-resistant MDD underwent 10 rTMS sessions over the bilateral dorsolateral prefrontal cortex. In addition to Hamilton Depression Rating Scale and Pittsburgh Sleep Quality Index scores, waist actigraphy was used to evaluate alterations in the rest-activity cycle over the course of rTMS treatments. Actigraphic data were evaluated at baseline and in the first (rTMS sessions 1-3), second (rTMS sessions 4-7), and third (rTMS sessions 8-10) sections. Although Hamilton Depression Rating Scale and Pittsburgh Sleep Quality Index scores were significantly improved by rTMS, sleep variables assessed by actigraphy did not show significant changes. However, post hoc tests indicated a significant increase in mean steps per day between the baseline and first section time points (P = 0.014; t13 = -2.316). Our data indicated that a daytime physical activity response to rTMS occurred in early sessions, whereas subjective symptom improvements were consistent across all sessions. Future double-blind placebo-controlled studies assessing the effects of rTMS on the rest-activity cycle and sleep disturbances in MDD are warranted.

[Therapeutic efficacy and safety of repetitive Transcranial Magnetic Stimulation in depressions of the elderly: a review].

PubMed

Jalenques, I; Legrand, G; Vaille-Perret, E; Tourtauchaux, R; Galland, F

2010-06-01

During the past 15 years, therapeutic effects of repetitive Transcranial Magnetic Stimulation (rTMS) have been studied in psychiatric diseases, particularly in the treatment of depressive disorders. There are more and more data suggesting its efficacy in the treatment of depression in older patients. Thus, the authors found it useful to conduct an up-to-date review of studies that examined the efficacy and safety of rTMS to treat depressive disorders in the aged. After an exhaustive consultation of databases (Medline/PubMed and the Avery-George-Holtzheimer Database of rTMS Depression Studies), supplemented by a manual research, the authors retained studies evaluating the therapeutic efficacy of rTMS on depressive disorders in the aged. Fifteen studies were retained. Four open studies using high frequency rTMS, applied to the left dorsolateral prefrontal cortex (DLPFC), demonstrated a decrease in the mean Hamilton Depression Rating Scale (HDRS) scores; however, only a quarter of the aged patients studied experienced a significant remission of depression. Five parallel arm double-blind versus placebo studies concluded in contradicting results: two studies confirmed a significantly greater efficacy of rTMS compared to placebo, whereas three studies did not; but the sham procedure (positioning coil at 90 degrees from the scalp) was disputable in most studies. One study concluded in therapeutic efficacy by inhibiting the right DLPFC. Three controlled parallel arm studies compared rTMS and electroconvulsive-therapy (ECT); one study concluded in greater efficacy of ECT at end of treatment, but the number of ECT treatments depended on the patients' response, whereas a 15-day course of rTMS was systematically administered; additionally HDRS scores were similar in two groups of patients (rTMS and ECT) at 6 months. Lastly, three studies focused on aged patients with cerebrovascular disease. They showed the efficacy of rTMS, although older age and smaller frontal gray mater volumes were associated with a poorer response to rTMS. Thus, although some studies concluded contradicting results, literature data globally sustain an efficacy of rTMS for depression in the elderly. Several parameters might be associated with greater antidepressant efficacy (higher intensity pulses of rTMS of the left DLPFC; higher number of stimulations or higher number of rTMS sessions). Poorer responsiveness to rTMS may be related to several patients' factors including older age and smaller frontal gray matter volumes; lesions of the white matter pathways connecting the left DLPFC and the left anterior cingulate cortex might explain a poor response to rTMS. Literature data globally confirm that rTMS is safe and does not produce cognitive deficits, even among highly vulnerable patients with clinical evidence of cerebrovascular disease. Many questions remain concerning the optimal stimulation parameters, administration protocol, and privileged indications. Thus, the next rTMS studies should be carefully designed to clarify these questions. Copyright (c) 2009 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Modulatory effects of high-frequency repetitive transcranial magnetic stimulation on the ipsilateral silent period.

PubMed

Cincotta, M; Giovannelli, F; Borgheresi, A; Balestrieri, F; Zaccara, G; Inghilleri, M; Berardelli, A

2006-06-01

In healthy subjects, suprathreshold repetitive transcranial magnetic stimulation (rTMS) at frequencies >2 Hz prolongs the cortical silent period (CSP) over the course of the train. This progressive lengthening probably reflects temporal summation of the inhibitory interneurons in the stimulated primary motor cortex (M1). In this study, we tested whether high-frequency rTMS also modulates the ipsilateral silent period (ISP). In nine normal subjects, suprathreshold 10-pulse rTMS trains were delivered to the right M1 at frequencies of 3, 5, and 10 Hz during maximal isometric contraction of both first dorsal interosseous muscles. At 10 Hz, the second pulse of the train increased the area of the ISP; the other stimuli did not increase it further. During rTMS at 3 and 5 Hz, the ISP remained significantly unchanged. Control experiments showed that 10-Hz rTMS delivered at subthreshold intensity also increased the ISP. rTMS over the hand motor area did not facilitate ISPs in the biceps muscles. Finally, rTMS-induced ISP facilitation did not outlast the 10-Hz rTMS train. These findings suggest that rTMS at a frequency of 10 Hz potentiates the interhemispheric inhibitory mechanisms responsible for the ISP, partly through temporal summation. The distinct changes in the ISP and CSP suggest that rTMS facilitates intrahemispheric and interhemispheric inhibitory phenomena through separate neural mechanisms. The ISP facilitation induced by high-frequency rTMS is a novel, promising tool to investigate pathophysiological abnormal interhemispheric inhibitory transfer in various neurological diseases.

rTMS: A Treatment to Restore Function After Severe TBI

DTIC Science & Technology

2017-10-01

rTMS- induced changes in functional neural activation and whether or not these changes correlate with improving neurobehavioral function. Aim III...will examine the effect of rTMS on white fiber tracts and whether or not the rTMS-related effects correlate with improving neurobehavioral function

23 CFR 500.204 - TMS components for highway traffic data.

Code of Federal Regulations, 2010 CFR

2010-04-01

... INFRASTRUCTURE MANAGEMENT MANAGEMENT AND MONITORING SYSTEMS Traffic Monitoring System § 500.204 TMS components for highway traffic data. (a) General. Each State's TMS, including those using alternative procedures... 23 Highways 1 2010-04-01 2010-04-01 false TMS components for highway traffic data. 500.204 Section...

The Integration and Applications of Organic Thin Film Transistors and Ferroelectric Polymers

NASA Astrophysics Data System (ADS)

Hsu, Yu-Jen

Organic thin film transistors and ferroelectric polymer (polyvinylidene difluoride) sheet material are integrated to form various sensors for stress/strain, acoustic wave, and Infrared (heat) sensing applications. Different from silicon-based transistors, organic thin film transistors can be fabricated and processed in room-temperature and integrated with a variety of substrates. On the other hand, polyvinylidene difluoride (PVDF) exhibits ferroelectric properties that are highly useful for sensor applications. The wide frequency bandwidth (0.001 Hz to 10 GHz), vast dynamic range (100n to 10M psi), and high elastic compliance (up to 3 percent) make PVDF a more suitable candidate over ceramic piezoelectric materials for thin and flexible sensor applications. However, the low Curie temperature may have impeded its integration with silicon technology. Organic thin film transistors, however, do not have the limitation of processing temperature, hence can serve as transimpedance amplifiers to convert the charge signal generated by PVDF into current signal that are more measurable and less affected by any downstream parasitics. Piezoelectric sensors are useful for a range of applications, but passive arrays suffer from crosstalk and signal attenuation which have complicated the development of array-based PVDF sensors. We have used organic field effect transistors, which are compatible with the low Curie temperature of a flexible piezoelectric polymer,PVDF, to monolithically fabricate transimpedance amplifiers directly on the sensor surface and convert the piezoelectric charge signal into a current signal which can be detected even in the presence of parasitic capacitances. The device couples the voltage generated by the PVDF film under strain into the gate of the organic thin film transistors (OFET) using an arrangement that allows the full piezoelectric voltage to couple to the channel, while also increasing the charge retention time. A bipolar detector is created by using a UV-Ozone treatment to shift the threshold voltage and increase the current of the transistor under both compressive and tensile strain. An array of strain sensors which maps the strain field on a PVDF film surface is demonstrated in this work. The strain sensor experience inspires a tone analyzer built using distributed resonator architecture on a tensioned piezoelectric PVDF sheet. This sheet is used as both the resonator and detection element. Two architectures are demonstrated; one uses distributed directly addressed elements as a proof of concept, and the other integrates organic thin film transistor-based transimpedance amplifiers monolithically with the PVDF sheet to convert the piezoelectric charge signal into a current signal for future applications such as sound field imaging. The PVDF sheet material is instrumented along its length and the amplitude response at 15 sites is recorded and analyzed as a function of the frequency of excitation. The determination of the dominant frequency component of an incoming sound is demonstrated using linear system decomposition of the time-averaged response of the sheet using no time domain detection. Our design allows for the determination of the spectral composition of a sound using the mechanical signal processing provided by the amplitude response and eliminates the need for time-domain electronic signal processing of the incoming signal. The concepts of the PVDF strain sensor and the tone analyzer trigger the idea of an active matrix microphone through the integration of organic thin film transistors with a freestanding piezoelectric polymer sheet. Localized acoustic pressure detection is enabled by switch transistors and local transimpedance amplification built into the active matrix architecture. The frequency of detection ranges from DC to 15KHz; the bandwidth is extended using an architecture that provides for virtually zero gate/source and gate/drain capacitance at the sensing transistors and low overlap capacitance at the switch transistors. A series of measurements are taken to demonstrate localized acoustic wave detection, high pitch sound diffraction pattern mapping, and directional listening. This system permits the direct visualization of a two dimensional sound field in a format that was previously inaccessible. In addition to the piezoelectric property, pyroelectricity is also exhibited by PVDF and is essential in the world of sensors. An integration of PVDF and OFET for the IR heat sensing is demonstrated to prove the concept of converting pyroelectric charge signal to a electric current signal. The basic pyroelectricity of PVDF sheet is first examined before making a organic transistor integrated IR sensor. Then, two types of architectures are designed and tested. The first one uses the structure similar to the PVDF strain sensor, and the second one uses a PVDF capacitor to gate the integrated OFETs. The conversion from pyroelectric signal to transistor current signal is observed and characterized. This design provides a flexible and gain-tunable version for IR heat sensors.

Transcranial Magnetic Stimulation and Aphasia Rehabilitation

PubMed Central

Naeser, Margaret A.; Martin, Paula I; Ho, Michael; Treglia, Ethan; Kaplan, Elina; Bhashir, Shahid; Pascual-Leone, Alvaro

2013-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been reported to improve naming in chronic stroke patients with nonfluent aphasia since 2005. In Part 1, we review the rationale for applying slow, 1 Hz, rTMS to the undamaged right hemisphere in chronic nonfluent aphasia patients following a left hemisphere stroke; and present a TMS protocol used with these patients that is associated with long-term, improved naming post- TMS. In Part, 2 we present results from a case study with chronic nonfluent aphasia where TMS treatments were followed immediately by speech therapy (constraint-induced language therapy). In Part 3, some possible mechanisms associated with improvement following a series of TMS treatments in stroke patients with aphasia are discussed. PMID:22202188

V/STOL tilt rotor research aircraft. Volume 3: Ship 2 instrumentation

NASA Technical Reports Server (NTRS)

1978-01-01

Information covering sensor cables, sensor installation, and sensor calibration for the XV-15 aircraft number 2 is included. For each junction box (J-box) designation there is a schematic of the J-box disconnect harness, instrumentation worksheets which show sensor location, and calibration data sheets for each sensor associated with that J-box. An index of measurement data codes to J-box locations is given in a table. Cross references are given.

V/STOL tilt rotor research aircraft. Volume 2: Ship 1 instrumentation

NASA Technical Reports Server (NTRS)

1978-01-01

Information covering sensor cables, sensor installation, and sensor calibration for the XV-15 aircraft number 1 is included. For each junction box (J-box) designation there is a schematic of the J-box disconnect harness instrumentation worksheets which show sensor location, and calibration data sheets for each sensor associated with that J-box. An index of measurement item codes to J-box locations is given in a table. Cross references are given.

[The Problems with Domestic Introduction of rTMS from the Three Viewpoints of Scientific Evidence, Specialty and Social Responsibility].

PubMed

Shinosaki, Kazuhiro

2015-01-01

The domestic introduction of rTMS is expected as a new treatment option for treatment-resistant depression. I discussed some problems with the introduction from three viewpoints : scientific evidence, specialty, and social responsibility. I surveyed scientific evidence for rTMS regarding the action mechanism, effectiveness, side effects, and its positioning in the treatment guidelines. To secure the quality of rTMS treatment, I proposed rTMS guidelines, nurturing of the specialists, and a center hospital plan, and pointed out some medium-term problems after its introduction and the consistency of rTMS treatment and standard depression treatment. From the viewpoint of social responsibility, rTMS treatment should be a medical service covered by health insurance to avoid its misuse. We should prepare to overcome the public suspicion of brain stimulation treatment for mental disease.

Effect of transcranial magnetic stimulation on force of finger pinch

NASA Astrophysics Data System (ADS)

Odagaki, Masato; Fukuda, Hiroshi; Hiwaki, Osamu

2009-04-01

Transcranial magnetic stimulation (TMS) is used to explore many aspects of brain function, and to treat neurological disorders. Cortical motor neuronal activation by TMS over the primary motor cortex (M1) produces efferent signals that pass through the corticospinal tracts. Motor-evoked potentials (MEPs) are observed in muscles innervated by the stimulated motor cortex. TMS can cause a silent period (SP) following MEP in voluntary electromyography (EMG). The present study examined the effects of TMS eliciting MEP and SP on the force of pinching using two fingers. Subjects pinched a wooden block with the thumb and index finger. TMS was applied to M1 during the pinch task. EMG of first dorsal interosseous muscles and pinch forces were measured. Force output increased after the TMS, and then oscillated. The results indicated that the motor control system to keep isotonic forces of the muscles participated in the finger pinch was disrupted by the TMS.

Safety of topical minoxidil solution: a one-year, prospective, observational study.

PubMed

Shapiro, Jerry

2003-01-01

Topical minoxidil solution (TMS) is widely used for androgenetic alopecia (AGA), and this is the first report of a large safety trial. The aim of the study was to evaluate the safety profile of TMS by comparing hospitalization and death rates among subjects using TMS with controls. Cardiovascular safety and pregnancy outcomes were evaluated, and usage patterns were described. All subjects were followed at baseline, 3, 6, 9, and 12 months. Usage patterns, pregnancy status, overnight hospital stays, and cardiovascular risk factors were evaluated. Subjects rated effectiveness of TMS in the treatment of AGA. Statistical analyses were conducted to determine if TMS was associated with an increased risk of death or hospitalization. TMS is a safe and effective treatment for AGA. There were no increases in cardiovascular events and no apparent increased risk for adverse pregnancy outcomes. This large, prospective study demonstrated the overall safety of TMS in the treatment of AGA.

A Comparison of Right Unilateral and Sequential Bilateral Repetitive Transcranial Magnetic Stimulation for Major Depression: A Naturalistic Clinical Australian Study.

PubMed

Galletly, Cherrie A; Carnell, Benjamin L; Clarke, Patrick; Gill, Shane

2017-03-01

A great deal of research has established the efficacy of repetitive transcranial magnetic stimulation (rTMS) in the treatment of depression. However, questions remain about the optimal method to deliver treatment. One area requiring consideration is the difference in efficacy between bilateral and unilateral treatment protocols. This study aimed to compare the effectiveness of sequential bilateral rTMS and right unilateral rTMS. A total of 135 patients participated in the study, receiving either bilateral rTMS (N = 57) or right unilateral rTMS (N = 78). Treatment response was assessed using the Hamilton depression rating scale. Sequential bilateral rTMS had a higher response rate than right unilateral (43.9% vs 30.8%), but this difference was not statistically significant. This was also the case for remission rates (33.3% vs 21.8%, respectively). Controlling for pretreatment severity of depression, the results did not indicate a significant difference between the protocols with regard to posttreatment Hamilton depression rating scale scores. The current study found no statistically significant differences in response and remission rates between sequential bilateral rTMS and right unilateral rTMS. Given the shorter treatment time and the greater safety and tolerability of right unilateral rTMS, this may be a better choice than bilateral treatment in clinical settings.

Blood flow and oxygenation changes due to low-frequency repetitive transcranial magnetic stimulation of the cerebral cortex

NASA Astrophysics Data System (ADS)

Mesquita, Rickson C.; Faseyitan, Olufunsho K.; Turkeltaub, Peter E.; Buckley, Erin M.; Thomas, Amy; Kim, Meeri N.; Durduran, Turgut; Greenberg, Joel H.; Detre, John A.; Yodh, Arjun G.; Hamilton, Roy H.

2013-06-01

Transcranial magnetic stimulation (TMS) modulates processing in the human brain and is therefore of interest as a treatment modality for neurologic conditions. During TMS administration, an electric current passing through a coil on the scalp creates a rapidly varying magnetic field that induces currents in the cerebral cortex. The effects of low-frequency (1 Hz), repetitive TMS (rTMS) on motor cortex cerebral blood flow (CBF) and tissue oxygenation in seven healthy adults, during/after 20 min stimulation, is reported. Noninvasive optical methods are employed: diffuse correlation spectroscopy (DCS) for blood flow and diffuse optical spectroscopy (DOS) for hemoglobin concentrations. A significant increase in median CBF (33%) on the side ipsilateral to stimulation was observed during rTMS and persisted after discontinuation. The measured hemodynamic parameter variations enabled computation of relative changes in cerebral metabolic rate of oxygen consumption during rTMS, which increased significantly (28%) in the stimulated hemisphere. By contrast, hemodynamic changes from baseline were not observed contralateral to rTMS administration (all parameters, p>0.29). In total, these findings provide new information about hemodynamic/metabolic responses to low-frequency rTMS and, importantly, demonstrate the feasibility of DCS/DOS for noninvasive monitoring of TMS-induced physiologic effects.

flexTMS--a novel repetitive transcranial magnetic stimulation device with freely programmable stimulus currents.

PubMed

Gattinger, Norbert; Moessnang, Georg; Gleich, Bernhard

2012-07-01

Transcranial magnetic stimulation (TMS) is able to noninvasively excite neuronal populations due to brief magnetic field pulses. The efficiency and the characteristics of stimulation pulse shapes influence the physiological effect of TMS. However, commercial devices allow only a minimum of control of different pulse shapes. Basically, just sinusoidal and monophasic pulse shapes with fixed pulse widths are available. Only few research groups work on TMS devices with controllable pulse parameters such as pulse shape or pulse width. We describe a novel TMS device with a full-bridge circuit topology incorporating four insulated-gate bipolar transistor (IGBT) modules and one energy storage capacitor to generate arbitrary waveforms. This flexible TMS (flexTMS ) device can generate magnetic pulses which can be adjusted with respect to pulse width, polarity, and intensity. Furthermore, the equipment allows us to set paired pulses with a variable interstimulus interval (ISI) from 0 to 20 ms with a step size of 10  μs. All user-defined pulses can be applied continually with repetition rates up to 30 pulses per second (pps) or, respectively, up to 100 pps in theta burst mode. Offering this variety of flexibility, flexTMS will allow the enhancement of existing TMS paradigms and novel research applications.

Determination of stimulation focality in heterogeneous head models during transcranial magnetic stimulation (TMS)

NASA Astrophysics Data System (ADS)

Lee, Erik; Hadimani, Ravi; Jiles, David

2015-03-01

Transcranial Magnetic Stimulation (TMS) is an increasingly popular tool used by both the scientific and medical community to understand and treat the brain. TMS has the potential to help people with a wide range of diseases such as Parkinson's, Alzheimer's, and PTSD, while currently being used to treat people with chronic, drug-resistant depression. Through computer simulations, we are able to see the electric field that TMS induces in anatomical human models, but there is no measure to quantify this electric field in a way that relates to a specific patient undergoing TMS therapy. We propose a way to quantify the focality of the induced electric field in a heterogeneous head model during TMS by relating the surface area of the brain being stimulated to the total volume of the brain being stimulated. This figure would be obtained by conducting finite element analysis (FEA) simulations of TMS therapy on a patient specific head model. Using this figure to assist in TMS therapy will allow clinicians and researchers to more accurately stimulate the desired region of a patient's brain and be more equipped to do comparative studies on the effects of TMS across different patients. This work was funded by the Carver Charitable Trust.

A novel coil array for combined TMS/fMRI experiments at 3 T

PubMed Central

Navarro de Lara, Lucia I.; Windischberger, Christian; Kuehne, Andre; Woletz, Michael; Sieg, Jürgen; Bestmann, Sven; Weiskopf, Nikolaus; Strasser, Bernhard; Moser, Ewald

2014-01-01

Purpose To overcome current limitations in combined transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) studies by employing a dedicated coil array design for 3 Tesla. Methods The state‐of‐the‐art setup for concurrent TMS/fMRI is to use a large birdcage head coil, with the TMS between the subject's head and the MR coil. This setup has drawbacks in sensitivity, positioning, and available imaging techniques. In this study, an ultraslim 7‐channel receive‐only coil array for 3 T, which can be placed between the subject's head and the TMS, is presented. Interactions between the devices are investigated and the performance of the new setup is evaluated in comparison to the state‐of‐the‐art setup. Results MR sensitivity obtained at the depth of the TMS stimulation is increased by a factor of five. Parallel imaging with an acceleration factor of two is feasible with low g‐factors. Possible interactions between TMS and the novel hardware were investigated and were found negligible. Conclusion The novel coil array is safe, strongly improves signal‐to‐noise ratio in concurrent TMS/fMRI experiments, enables parallel imaging, and allows for flexible positioning of the TMS on the head while ensuring efficient TMS stimulation due to its ultraslim design. Magn Reson Med 74:1492–1501, 2015. © 2014 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. PMID:25421603

rTMS with Motor Training Modulates Cortico-Basal Ganglia-Thalamocortical Circuits in Stroke Patients

PubMed Central

Chang, Won Hyuk; Kim, Yun-Hee; Yoo, Woo-Kyoung; Goo, Kyoung-Hyup; Park, Chang-hyun; Kim, Sung Tae; Pascual-Leone, Alvaro

2013-01-01

Background and Purpose Repetitive transcranial magnetic stimulation (rTMS) may enhance plastic changes in the human cortex and modulation of behavior. However, the underlying neural mechanisms have not been sufficiently investigated. We examined the clinical effects and neural correlates of high-frequency rTMS coupled with motor training in patients with hemiparesis after stroke. Methods Twenty-one patients were randomly divided into two groups, and received either real or sham rTMS. Ten daily sessions of 1,000 pulses of real or sham rTMS were applied at 10 Hz over the primary motor cortex of the affected hemisphere, coupled with sequential finger motor training of the paretic hand. Functional MRIs were obtained before and after training using sequential finger motor tasks, and performances were assessed. Results Following rTMS intervention, movement accuracy of sequential finger motor tasks showed significantly greater improvement in the real group than in the sham group (p<0.05). Real rTMS modulated areas of brain activation during performance of motor tasks with a significant interaction effect in the sensorimotor cortex, thalamus, and caudate nucleus. Patients in the real rTMS group also showed significantly enhanced activation in the affected hemisphere compared to the sham rTMS group. Conclusion According to these results, a 10 day course of high-frequency rTMS coupled with motor training improved motor performance through modulation of activities in the cortico-basal ganglia-thalamocortical circuits. PMID:22555430

Neuromodulation integrating rTMS and neurofeedback for the treatment of autism spectrum disorder: an exploratory study.

PubMed

Sokhadze, Estate M; El-Baz, Ayman S; Tasman, Allan; Sears, Lonnie L; Wang, Yao; Lamina, Eva V; Casanova, Manuel F

2014-12-01

Autism spectrum disorder (ASD) is a pervasive developmental disorder characterized by deficits in social interaction, language, stereotyped behaviors, and restricted range of interests. In previous studies low frequency repetitive transcranial magnetic stimulation (rTMS) has been used, with positive behavioral and electrophysiological results, for the experimental treatment in ASD. In this study we combined prefrontal rTMS sessions with electroencephalographic (EEG) neurofeedback (NFB) to prolong and reinforce TMS-induced EEG changes. The pilot trial recruited 42 children with ASD (~14.5 years). Outcome measures included behavioral evaluations and reaction time test with event-related potential (ERP) recording. For the main goal of this exploratory study we used rTMS-neurofeedback combination (TMS-NFB, N = 20) and waitlist (WTL, N = 22) groups to examine effects of 18 sessions of integrated rTMS-NFB treatment or wait period) on behavioral responses, stimulus and response-locked ERPs, and other functional and clinical outcomes. The underlying hypothesis was that combined TMS-NFB will improve executive functions in autistic patients as compared to the WTL group. Behavioral and ERP outcomes were collected in pre- and post-treatment tests in both groups. Results of the study supported our hypothesis by demonstration of positive effects of combined TMS-NFB neurotherapy in active treatment group as compared to control WTL group, as the TMS-NFB group showed significant improvements in behavioral and functional outcomes as compared to the WTL group.

Neuromodulation integrating rTMS and neurofeedback for the treatment of autism spectrum disorder: An exploratory study

PubMed Central

Sokhadze, Estate M.; El-Baz, Ayman S.; Tasman, Allan; Sears, Lonnie L.; Wang, Yao; Lamina, Eva V.; Casanova, Manuel F.

2014-01-01

Autism spectrum disorder (ASD) is a pervasive developmental disorder characterized by deficits in social interaction, language, stereotyped behaviors, and restricted range of interests. In previous studies low frequency repetitive transcranial magnetic stimulation (rTMS) has been used, with positive behavioral and electrophysiological results, for the experimental treatment in ASD. In this study we combined prefrontal rTMS sessions with electroencephalographic (EEG) neurofeedback (NFB) to prolong and reinforce TMS-induced EEG changes. The pilot trial recruited 42 children with ASD (~14.5 yrs). Outcome measures included behavioral evaluations and reaction time test with event-related potential (ERP) recording. For the main goal of this exploratory study we used rTMS-neurofeedback combination (TMS-NFB, N=20) and waitlist (WTL, N=22) groups to examine effects of 18 sessions of integrated rTMS-NFB treatment or wait period) on behavioral responses, stimulus and response-locked ERPs, and other functional and clinical outcomes. The underlying hypothesis was that combined TMS-NFB will improve executive functions in autistic patients as compared to the waitlist group. Behavioral and ERP outcomes were collected in pre- and post-treatment tests in both groups. Results of the study supported our hypothesis by demonstration of positive effects of combined TMS-NFB neurotherapy in active treatment group as compared to control waitlist group, as the TMS-NFB group showed significant improvements in behavioral and functional outcomes as compared to the waitlist group. PMID:25267414

Short-term modulation of regional excitability and blood flow in human motor cortex following rapid-rate transcranial magnetic stimulation.

PubMed

Takano, Beatrice; Drzezga, Alexander; Peller, Martin; Sax, Iris; Schwaiger, Markus; Lee, Lucy; Siebner, Hartwig Roman

2004-11-01

Repetitive transcranial magnetic stimulation (rTMS) of the human primary motor cortex (M1) provides a means of inducing lasting changes in cortical excitability and synaptic activity. Here we combined rTMS with positron emission tomography of regional cerebral blood flow (rCBF) to examine how an rTMS-induced change in intracortical excitability of inhibitory circuits affects regional synaptic activity. In a first set of experiments, we gave 150 biphasic pulses of 5 Hz rTMS at 90% of active motor threshold to left M1 and used single- and paired-pulse TMS to assess the conditioning effects of rTMS on motor cortical excitability at rest. rTMS conditioning led to a selective decrease in short-latency intracortical inhibition (SICI) without affecting short-latency intracortical facilitation or corticospinal excitability. The decrease in SICI lasted for approximately 8 min. In a second experiment, we used the same rTMS protocol and measured changes in regional synaptic activity (as indexed by rCBF) during and for up to 14 min after the end of rTMS. Subthreshold 5 Hz rTMS induced a region-specific increase in resting rCBF in the stimulated M1 lasting approximately 8 min. These results suggest that in the stimulated M1, temporary attenuation of SICI is paralleled by an increase in synaptic activity, consistent with reduced efficacy of intracortical GABA(A)-ergic synapses. The present findings demonstrate that short trains of low-intensity 5 Hz rTMS can be used to induce a transient change in function within a distinct cortical area. This opens up new possibilities for studying acute reorganization at the systems level in the intact human brain.

Assessing TMS-induced D and I waves with spinal H-reflexes.

PubMed

Niemann, Niclas; Wiegel, Patrick; Kurz, Alexander; Rothwell, John C; Leukel, Christian

2018-03-01

Transcranial magnetic stimulation (TMS) of motor cortex produces a series of descending volleys known as D (direct) and I (indirect) waves. In the present study, we questioned whether spinal H-reflexes can be used to dissect D waves and early and late I waves from TMS. We therefore probed H-reflex facilitation at arrival times of D and I waves at the spinal level and thereby changed TMS parameters that have previously been shown to have selective effects on evoked D and different I waves. We changed TMS intensity and current direction and applied a double-pulse paradigm known as short-interval intracortical inhibition (SICI). Experiments were conducted in flexor carpi radialis (FCR) in the arm and soleus (SOL) in the leg. There were two major findings: 1) in FCR, H-reflex facilitation showed characteristic modulations with altered TMS parameters that correspond to the changes of evoked D and I waves; and 2) H-reflexes in SOL did not, possibly because of increased interference from other spinal circuits. Therefore, the most significant outcome of this study is that in FCR, H-reflexes combined with TMS seem to be a useful technique to dissect TMS-induced D and I waves. NEW & NOTEWORTHY Questions that relate to corticospinal function in pathophysiology and movement control demand sophisticated techniques to provide information about corticospinal mechanisms. We introduce a noninvasive electrophysiological technique that may be useful in describing such mechanisms in more detail by dissecting D and I waves from transcranial magnetic stimulation (TMS). Based on the combination of spinal H-reflexes and TMS in the flexor carpi radialis muscle, the technique was shown to measure selective effects on D and I waves from changing TMS parameters.

Probing the frontostriatal loops involved in executive and limbic processing via interleaved TMS and functional MRI at two prefrontal locations: a pilot study.

PubMed

Hanlon, Colleen A; Canterberry, Melanie; Taylor, Joseph J; DeVries, William; Li, Xingbao; Brown, Truman R; George, Mark S

2013-01-01

The prefrontal cortex (PFC) is an anatomically and functionally heterogeneous area which influences cognitive and limbic processing through connectivity to subcortical targets. As proposed by Alexander et al. (1986) the lateral and medial aspects of the PFC project to distinct areas of the striatum in parallel but functionally distinct circuits. The purpose of this preliminary study was to determine if we could differentially and consistently activate these lateral and medial cortical-subcortical circuits involved in executive and limbic processing though interleaved transcranial magnetic stimulation (TMS) in the MR environment. Seventeen healthy individuals received interleaved TMS-BOLD imaging with the coil positioned over the dorsolateral (EEG: F3) and ventromedial PFC (EEG: FP1). BOLD signal change was calculated in the areas directly stimulated by the coil and in subcortical regions with afferent and efferent connectivity to the TMS target areas. Additionally, five individuals were tested on two occasions to determine test-retest reliability. Region of interest analysis revealed that TMS at both prefrontal sites led to significant BOLD signal increases in the cortex under the coil, in the striatum, and the thalamus, but not in the visual cortex (negative control region). There was a significantly larger BOLD signal change in the caudate following medial PFC TMS, relative to lateral TMS. The hippocampus in contrast was significantly more activated by lateral TMS. Post-hoc voxel-based analysis revealed that within the caudate the location of peak activity was in the ventral caudate following medial TMS and the dorsal caudate following lateral TMS. Test-retest reliability data revealed consistent BOLD responses to TMS within each individual but a large variation between individuals. These data demonstrate that, through an optimized TMS/BOLD sequence over two unique prefrontal targets, it is possible to selectively interrogate the patency of these established cortical-subcortical networks in healthy individuals, and potentially patient populations.

Effects of low-frequency repetitive transcranial magnetic stimulation on event-related potential P300

NASA Astrophysics Data System (ADS)

Torii, Tetsuya; Sato, Aya; Iwahashi, Masakuni; Iramina, Keiji

2012-04-01

The present study analyzed the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. P300 latency of event-related potential (ERP) was used to evaluate the effects of low-frequency and short-term rTMS by stimulating the supramarginal gyrus (SMG), which is considered to be the related area of P300 origin. In addition, the prolonged stimulation effects on P300 latency were analyzed after applying rTMS. A figure-eight coil was used to stimulate left-right SMG, and intensity of magnetic stimulation was 80% of motor threshold. A total of 100 magnetic pulses were applied for rTMS. The effects of stimulus frequency at 0.5 or 1 Hz were determined. Following rTMS, an odd-ball task was performed and P300 latency of ERP was measured. The odd-ball task was performed at 5, 10, and 15 min post-rTMS. ERP was measured prior to magnetic stimulation as a control. Electroencephalograph (EEG) was measured at Fz, Cz, and Pz that were indicated by the international 10-20 electrode system. Results demonstrated that different effects on P300 latency occurred between 0.5-1 Hz rTMS. With 1 Hz low-frequency magnetic stimulation to the left SMG, P300 latency decreased. Compared to the control, the latency time difference was approximately 15 ms at Cz. This decrease continued for approximately 10 min post-rTMS. In contrast, 0.5 Hz rTMS resulted in delayed P300 latency. Compared to the control, the latency time difference was approximately 20 ms at Fz, and this delayed effect continued for approximately 15 min post-rTMS. Results demonstrated that P300 latency varied according to rTMS frequency. Furthermore, the duration of the effect was not similar for stimulus frequency of low-frequency rTMS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scherzberg, Maria-Christina; Kiehl, Andreas; Zivkovic, Aleksandra

(Z)-3,5,4′-Trimethoxystilbene (Z-TMS) is a resveratrol analog with increased antiproliferative activity towards a number of cancer cell lines compared to resveratrol, which has been shown to inhibit tubulin polymerization in vitro. The purpose of this study was to investigate if Z-TMS still shows potential for the prevention of metabolic diseases as known for resveratrol. Cell growth inhibition was determined with IC{sub 50} values for Z-TMS between 0.115 μM and 0.473 μM (resveratrol: 110.7 μM to 190.2 μM). Flow cytometric analysis revealed a G{sub 2}/M arrest after Z-TMS treatment, whereas resveratrol caused S phase arrest. Furthermore, Z-TMS was shown to impair microtubulemore » polymerization. Beneficial effects on lipid accumulation were observed for resveratrol, but not for Z-TMS in an in vitro steatosis model. (E)-Resveratrol was confirmed to elevate cAMP levels, and knockdown of AMPK attenuated the antiproliferative activity, while Z-TMS did not show significant effects in these experiments. SIRT1 and AMPK activities were further measured indirectly via induction of the target gene small heterodimer partner (SHP). Thereby, (E)-resveratrol, but not Z-TMS, showed potent induction of SHP mRNA levels in an AMPK- and SIRT1-dependent manner, as confirmed by knockdown experiments. We provide evidence that Z-TMS does not show beneficial metabolic effects, probably due to loss of activity towards resveratrol target genes. Moreover, our data support previous findings that Z-TMS acts as an inhibitor of tubulin polymerization. These findings confirm that the methylation of resveratrol leads to profound changes in the mode of action, which should be taken into consideration when conducting lead structure optimization approaches. - Highlights: • Methylation of resveratrol leads to profound changes in biologic activity. • Z-TMS does not prevent hepatic steatosis, but inhibits tubulin polymerization. • Resveratrol analog Z-TMS does not influence known targets like PDEs, SIRT1, or AMPK. • Resveratrol, but not Z-TMS, potently induces SHP mRNA dependent on AMPK and SIRT1.« less

Neurotransmitters behind pain relief with transcranial magnetic stimulation - positron emission tomography evidence for release of endogenous opioids.

PubMed

Lamusuo, S; Hirvonen, J; Lindholm, P; Martikainen, I K; Hagelberg, N; Parkkola, R; Taiminen, T; Hietala, J; Helin, S; Virtanen, A; Pertovaara, A; Jääskeläinen, S K

2017-10-01

Repetitive transcranial magnetic stimulation (rTMS) at M1/S1 cortex has been shown to alleviate neuropathic pain. To investigate the possible neurobiological correlates of cortical neurostimulation for the pain relief. We studied the effects of M1/S1 rTMS on nociception, brain dopamine D2 and μ-opioid receptors using a randomized, sham-controlled, double-blinded crossover study design and 3D-positron emission tomography (PET). Ten healthy subjects underwent active and sham rTMS treatments to the right M1/S1 cortex with E-field navigated device. Dopamine D2 and μ-receptor availabilities were assessed with PET radiotracers [ 11 C]raclopride and [ 11 C]carfentanil after each rTMS treatment. Thermal quantitative sensory testing (QST), contact heat evoked potential (CHEP) and blink reflex (BR) recordings were performed between the PET scans. μ-Opioid receptor availability was lower after active than sham rTMS (P ≤ 0.0001) suggested release of endogenous opioids in the right ventral striatum, medial orbitofrontal, prefrontal and anterior cingulate cortices, and left insula, superior temporal gyrus, dorsolateral prefrontal cortex and precentral gyrus. There were no differences in striatal dopamine D2 receptor availability between active and sham rTMS, consistent with lack of long-lasting measurable dopamine release. Active rTMS potentiated the dopamine-regulated habituation of the BR compared to sham (P = 0.02). Thermal QST and CHEP remained unchanged after active rTMS. rTMS given to M1/S1 activates the endogenous opioid system in a wide brain network associated with processing of pain and other salient stimuli. Direct enhancement of top-down opioid-mediated inhibition may partly explain the clinical analgesic effects of rTMS. Neurobiological correlates of rTMS for the pain relief are unclear. rTMS on M1/S1 with 11 C-carfentanyl-PET activates endogenous opioids. Thermal and heat pain thresholds remain unchanged. rTMS induces top-down opioid-mediated inhibition but not change the sensory discrimination of painful stimuli. © 2017 European Pain Federation - EFIC®.

Attention Modulates TMS-Locked Alpha Oscillations in the Visual Cortex

PubMed Central

Herring, Jim D.; Thut, Gregor; Jensen, Ole

2015-01-01

Cortical oscillations, such as 8–12 Hz alpha-band activity, are thought to subserve gating of information processing in the human brain. While most of the supporting evidence is correlational, causal evidence comes from attempts to externally drive (“entrain”) these oscillations by transcranial magnetic stimulation (TMS). Indeed, the frequency profile of TMS-evoked potentials (TEPs) closely resembles that of oscillations spontaneously emerging in the same brain region. However, it is unclear whether TMS-locked and spontaneous oscillations are produced by the same neuronal mechanisms. If so, they should react in a similar manner to top-down modulation by endogenous attention. To test this prediction, we assessed the alpha-like EEG response to TMS of the visual cortex during periods of high and low visual attention while participants attended to either the visual or auditory modality in a cross-modal attention task. We observed a TMS-locked local oscillatory alpha response lasting several cycles after TMS (but not after sham stimulation). Importantly, TMS-locked alpha power was suppressed during deployment of visual relative to auditory attention, mirroring spontaneous alpha amplitudes. In addition, the early N40 TEP component, located at the stimulation site, was amplified by visual attention. The extent of attentional modulation for both TMS-locked alpha power and N40 amplitude did depend, with opposite sign, on the individual ability to modulate spontaneous alpha power at the stimulation site. We therefore argue that TMS-locked and spontaneous oscillations are of common neurophysiological origin, whereas the N40 TEP component may serve as an index of current cortical excitability at the time of stimulation. SIGNIFICANCE STATEMENT Rhythmic transcranial magnetic stimulation (TMS) is a promising tool to experimentally “entrain” cortical activity. If TMS-locked oscillatory responses actually recruit the same neuronal mechanisms as spontaneous cortical oscillations, they qualify as a valid tool to study the causal role of neuronal oscillations in cognition but also to enable new treatments targeting aberrant oscillatory activity in, for example, neurological conditions. Here, we provide first-time evidence that TMS-locked and spontaneous oscillations are indeed tightly related and are likely to rely on the same neuronal generators. In addition, we demonstrate that an early local component of the TMS-evoked potential (the N40) may serve as a new objective and noninvasive probe of visual cortex excitability, which so far was only accessible via subjective phosphene reports. PMID:26511236

Repetitive Transcranial Magnetic Stimulation for Treatment-Resistant Depression in Adult and Youth Populations: A Systematic Literature Review and Meta-Analysis

PubMed Central

Leggett, Laura E.; Soril, Lesley J. J.; Coward, Stephanie; Lorenzetti, Diane L.; MacKean, Gail; Clement, Fiona M.

2015-01-01

Background: Between 30% and 60% of individuals with major depressive disorder will have treatment-resistant depression (TRD): depression that does not subside with pharmaceutical treatment. Repetitive transcranial magnetic stimulation (rTMS) is an emerging treatment for TRD. Objective: To establish the efficacy and optimal protocol for rTMS among adults and youth with TRD. Data Sources: Two systematic reviews were conducted: one to determine the efficacy of rTMS for adults with TRD and another to determine the effectiveness of rTMS for youth with TRD. For adults, MEDLINE, Cochrane Central Register of Controlled Trials, PubMed, EMBASE, PsycINFO, Cochrane Database of Systematic Reviews, and Health Technology Assessment Database were searched from inception until January 10, 2014 with no language restrictions. Terms aimed at capturing the target diagnosis, such as depression and depressive disorder, were combined with terms describing the technology, such as transcranial magnetic stimulation and rTMS. Results were limited to studies involving human participants and designed as a randomized controlled trial. For youth, the search was altered to include youth only (aged 13–25 years) and all study designs. When possible, meta-analysis of response and remission rates was conducted. Study Selection: Seventy-three articles were included in this review: 70 on adult and 3 on youth populations. Results: Meta-analysis comparing rTMS and sham in adults found statistically significant results favoring rTMS for response (RR: 2.35 [95% CI, 1.70–3.25]) and remission (RR: 2.24 [95% CI, 1.53–3.27]). No statistically significant differences were found when comparing high- and low-frequency, unilateral and bilateral, low- and high-intensity rTMS or rTMS and electroconvulsive therapy (ECT). While meta-analysis of results from the youth literature was not possible, the limited evidence base suggests that rTMS may be effective for treating TRD in youth. Conclusions: The evidence available on the use of rTMS for adults with TRD indicates that rTMS is approximately twice as effective as a sham procedure, although the optimal rTMS protocol remains unclear. Evidence also indicates that rTMS is as effective as ECT and appears promising as a treatment for youth with TRD; however, the evidence base is underdeveloped. PMID:27057417

Combined noninvasive language mapping by navigated transcranial magnetic stimulation and functional MRI and its comparison with direct cortical stimulation.

PubMed

Ille, Sebastian; Sollmann, Nico; Hauck, Theresa; Maurer, Stefanie; Tanigawa, Noriko; Obermueller, Thomas; Negwer, Chiara; Droese, Doris; Zimmer, Claus; Meyer, Bernhard; Ringel, Florian; Krieg, Sandro M

2015-07-01

Repetitive navigated transcranial magnetic stimulation (rTMS) is now increasingly used for preoperative language mapping in patients with lesions in language-related areas of the brain. Yet its correlation with intraoperative direct cortical stimulation (DCS) has to be improved. To increase rTMS's specificity and positive predictive value, the authors aim to provide thresholds for rTMS's positive language areas. Moreover, they propose a protocol for combining rTMS with functional MRI (fMRI) to combine the strength of both methods. The authors performed multimodal language mapping in 35 patients with left-sided perisylvian lesions by using rTMS, fMRI, and DCS. The rTMS mappings were conducted with a picture-to-trigger interval (PTI, time between stimulus presentation and stimulation onset) of either 0 or 300 msec. The error rates (ERs; that is, the number of errors per number of stimulations) were calculated for each region of the cortical parcellation system (CPS). Subsequently, the rTMS mappings were analyzed through different error rate thresholds (ERT; that is, the ER at which a CPS region was defined as language positive in terms of rTMS), and the 2-out-of-3 rule (a stimulation site was defined as language positive in terms of rTMS if at least 2 out of 3 stimulations caused an error). As a second step, the authors combined the results of fMRI and rTMS in a predefined protocol of combined noninvasive mapping. To validate this noninvasive protocol, they correlated its results to DCS during awake surgery. The analysis by different rTMS ERTs obtained the highest correlation regarding sensitivity and a low rate of false positives for the ERTs of 15%, 20%, 25%, and the 2-out-of-3 rule. However, when comparing the combined fMRI and rTMS results with DCS, the authors observed an overall specificity of 83%, a positive predictive value of 51%, a sensitivity of 98%, and a negative predictive value of 95%. In comparison with fMRI, rTMS is a more sensitive but less specific tool for preoperative language mapping than DCS. Moreover, rTMS is most reliable when using ERTs of 15%, 20%, 25%, or the 2-out-of-3 rule and a PTI of 0 msec. Furthermore, the combination of fMRI and rTMS leads to a higher correlation to DCS than both techniques alone, and the presented protocols for combined noninvasive language mapping might play a supportive role in the language-mapping assessment prior to the gold-standard intraoperative DCS.

Repetitive Transcranial Magnetic Stimulation for Treatment-Resistant Depression: An Economic Analysis

PubMed Central

Tu, Hong Anh; Palimaka, Stefan; Sehatzadeh, Shayan; Blackhouse, Gord; Yap, Belinda; Tsoi, Bernice; Bowen, Jim; O'Reilly, Daria; Holubowich, Corinne; Kaulback, Kellee; Campbell, Kaitryn

2016-01-01

Background Major depressive disorder (MDD, 10% over a person's lifetime) is common and costly to the health system. Unfortunately, many MDD cases are resistant to treatment with antidepressant drugs and require other treatment to reduce or eliminate depression. Electroconvulsive therapy (ECT) has long been used to treat persons with treatment-resistant depression (TRD). Despite its effectiveness, ECT has side effects that make patients intolerant to the treatment, or they refuse to use it. Repetitive transcranial magnetic stimulation (rTMS), which has fewer side effects than ECT and might be an alternative for TRD patients who are ineligible for or unwilling to undergo ECT, has been developed to treat TRD. Objectives This analysis evaluates the cost-effectiveness of rTMS for patients with TRD compared with ECT or sham rTMS and estimates the potential budgetary impact of various levels of implementation of rTMS in Ontario. Review Methods A cost-utility analysis compared the costs and health outcomes of two treatments for persons with TRD in Ontario: rTMS alone compared with ECT alone and rTMS alone compared with sham rTMS. We calculated the six-month incremental costs and quality-adjusted life-years (QALYs) for these treatments. One-way and probabilistic sensitivity analyses were performed to test the robustness of the model's results. A 1-year budget impact analysis estimated the costs of providing funding for rTMS. The base-case analysis examined the additional costs for funding six centres, where rTMS infrastructure is in place. Sensitivity and scenario analyses explored the impact of increasing diffusion of rTMS to centres with existing ECT infrastructure. All analyses were conducted from the Ontario health care payer perspective. Results ECT was cost effective compared to rTMS when the willingness to pay is greater than $37,640.66 per QALY. In the base-case analysis, which had a six-month time horizon, the cost and effectiveness for rTMS was $5,272 and 0.31 quality-adjusted life-years (QALYs). The cost and effectiveness for ECT were $5,960 and 0.32 QALYs. This translates in an incremental cost-effectiveness ratio of $37,640.66 per QALY gained for ECT compared to rTMS. When rTMS is compared with sham rTMS, an additional $2,154.33 would be spent to gain 0.02 QALY. This translates to an ICER of $98,242.37 per QALY gained. Probabilistic sensitivity analysis showed that the probability of rTMS being cost-effective compared to sham rTMS was 2% and 45% at the thresholds of $50,000 and $100,000 per QALY gained, respectively. Conclusions Repetitive transcranial magnetic stimulation may be cost-effective compared to sham treatment in patients with treatment-resistant depression, depending on the willingness-to-pay threshold. PMID:27110317

Scanning mutagenesis studies reveal a potential intramolecular interaction within the C-terminal half of dengue virus NS2A involved in viral RNA replication and virus assembly and secretion.

PubMed

Wu, Ren-Huang; Tsai, Ming-Han; Chao, Day-Yu; Yueh, Andrew

2015-04-01

The NS2A protein of dengue virus (DENV) has eight predicted transmembrane segments (pTMSs; pTMS1 to pTMS8). NS2A has been shown to participate in RNA replication, virion assembly, and the host antiviral response. However, the role of the amino acid residues within the pTMS regions of NS2A during the virus life cycle is poorly understood. In the study described here, we explored the function of DENV NS2A by introducing a series of double or triple alanine substitutions into the C-terminal half (pTMS4 to pTMS8) of NS2A in the context of a DENV infectious clone or subgenomic replicon. Fourteen (8 within pTMS8) of 35 NS2A mutants displayed a lethal phenotype due to impairment of RNA replication by a replicon assay. Three NS2A mutants with mutations within pTMS7, the CM20, CM25, and CM27 mutants, displayed similar phenotypes, low virus yields (>100-fold reduction), wild-type-like replicon activity, and low infectious virus-like particle yields by transient trans-packaging experiments, suggesting a defect in virus assembly and secretion. The sequencing of revertant viruses derived from CM20, CM25, and CM27 mutant viruses revealed a consensus reversion mutation, leucine (L) to phenylalanine (F), at codon 181 within pTMS7. The introduction of an L181F mutation into a full-length NS2A mutant, i.e., the CM20, CM25, and CM27 constructs, completely restored wild-type infectivity. Notably, L181F also substantially rescued the other severely RNA replication-defective mutants with mutations within pTMS4, pTMS6, and pTMS8, i.e., the CM2, CM3, CM13, CM31, and CM32 mutants. In conclusion, the results revealed the essential roles of pTMS4 to pTMS8 of NS2A in RNA replication and/or virus assembly and secretion. The intramolecular interaction between pTMS7 and pTMS4, pTMS6, or pTMS8 of the NS2A protein was also implicated. The reported characterization of the C-terminal half of dengue virus NS2A is the first comprehensive mutagenesis study to investigate the function of flavivirus NS2A involved in the steps of the virus life cycle. In particular, detailed mapping of the amino acid residues within the predicted transmembrane segments (pTMSs) of NS2A involved in RNA replication and/or virus assembly and secretion was performed. A revertant genetics study also revealed that L181F within pTMS7 is a consensus reversion mutation that rescues both RNA replication-defective and virus assembly- and secretion-defective mutants with mutations within the other three pTMSs of NS2A. Collectively, these findings elucidate the role played by NS2A during the virus life cycle, possibly through the intricate intramolecular interaction between pTMS7 and other pTMSs within the NS2A protein. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Navigated transcranial magnetic stimulation for glioma removal: prognostic value in motor function recovery from postsurgical neurological deficits.

PubMed

Takakura, Tomokazu; Muragaki, Yoshihiro; Tamura, Manabu; Maruyama, Takashi; Nitta, Masayuki; Niki, Chiharu; Kawamata, Takakazu

2017-10-01

OBJECTIVE The aim of the present study was to evaluate the usefulness of navigated transcranial magnetic stimulation (nTMS) as a prognostic predictor for upper-extremity motor functional recovery from postsurgical neurological deficits. METHODS Preoperative and postoperative nTMS studies were prospectively applied in 14 patients (mean age 39 ± 12 years) who had intraparenchymal brain neoplasms located within or adjacent to the motor eloquent area in the cerebral hemisphere. Mapping by nTMS was done 3 times, i.e., before surgery, and 1 week and 3 weeks after surgery. To assess the response induced by nTMS, motor evoked potential (nTMS-MEP) was recorded using a surface electromyography electrode attached to the abductor pollicis brevis (APB). The cortical locations that elicited the largest electromyography response by nTMS were defined as hotspots. Hotspots for APB were confirmed as positive responsive sites by direct electrical stimulation (DES) during awake craniotomy. The distances between hotspots and lesions (D HS-L ) were measured. Postoperative neurological deficits were assessed by manual muscle test and dynamometer. To validate the prognostic value of nTMS in recovery from upper-extremity paresis, the following were investigated: 1) the correlation between D HS-L and the serial grip strength change, and 2) the correlation between positive nTMS-MEP at 1 week after surgery and the serial grip strength change. RESULTS From the presurgical nTMS study, MEPs from targeted muscles were identified in 13 cases from affected hemispheres. In one case, MEP was not evoked due to a huge tumor. Among 9 cases from which intraoperative DES mapping for hand motor area was available, hotspots for APB identified by nTMS were concordant with DES-positive sites. Compared with the adjacent group (D HS-L < 10 mm, n = 6), the nonadjacent group (D HS-L ≥ 10 mm, n = 7) showed significantly better recovery of grip strength at 3 months after surgery (p < 0.01). There were correlations between D HS-L and recovery of grip strength at 1 week, 3 weeks, and 3 months after surgery (r = 0.74, 0.68, and 0.65, respectively). Postsurgical nTMS was accomplished in 13 patients. In 9 of 13 cases, nTMS-MEP from APB muscle was positive at 1 week after surgery. Excluding the case in which nTMS-MEP was negative from the presurgical nTMS study, recoveries in grip strength were compared between 2 groups, in which nTMS-MEP at 1 week after surgery was positive (n = 9) or negative (n = 3). Significant differences were observed between the 2 groups at 1 week, 3 weeks, and 3 months after surgery (p < 0.01). Positive nTMS-MEP at 1 week after surgery correlated well with the motor recovery at 1 week, 3 weeks, and 3 months after surgery (r = 0.87, 0.88, and 0.77, respectively). CONCLUSIONS Navigated TMS is a useful tool for identifying motor eloquent areas. The results of the present study have demonstrated the predictive value of nTMS in upper-extremity motor function recovery from postsurgical neurological deficits. The longer D HS-L and positive nTMS-MEP at 1 week after surgery have prognostic values of better recovery from postsurgical neurological deficits.

Operations-Focused Optimized Theater Weather Sensing Strategies Using Preemptive Binary Integer Programming

DTIC Science & Technology

2009-03-01

8217 Clear old problem data Do While Trim(Sheets("Campaign").Range("AF" & CStr (LOOP_COUNTER))) <> "" LOOP_COUNTER = LOOP_COUNTER + 1 Loop Do While...Trim(Sheets("Campaign").Range("A" & CStr (LOOP_COUNTER))) <> "" ’ Loop through all problem instances Sheets("Campaign").Range("R1:AF1").Rows...total number of locations M = Sheets("Campaign").Range("F" & CStr (LOOP_COUNTER)) ’ Record total number of sensor types N

The extreme melt across the Greenland ice sheet in 2012

NASA Astrophysics Data System (ADS)

Nghiem, S. V.; Hall, D. K.; Mote, T. L.; Tedesco, M.; Albert, M. R.; Keegan, K.; Shuman, C. A.; DiGirolamo, N. E.; Neumann, G.

2012-10-01

The discovery of the 2012 extreme melt event across almost the entire surface of the Greenland ice sheet is presented. Data from three different satellite sensors - including the Oceansat-2 scatterometer, the Moderate-resolution Imaging Spectroradiometer, and the Special Sensor Microwave Imager/Sounder - are combined to obtain composite melt maps, representing the most complete melt conditions detectable across the ice sheet. Satellite observations reveal that melt occurred at or near the surface of the Greenland ice sheet across 98.6% of its entire extent on 12 July 2012, including the usually cold polar areas at high altitudes like Summit in the dry snow facies of the ice sheet. This melt event coincided with an anomalous ridge of warm air that became stagnant over Greenland. As seen in melt occurrences from multiple ice core records at Summit reported in the published literature, such a melt event is rare with the last significant one occurring in 1889 and the next previous one around seven centuries earlier in the Medieval Warm Period. Given its rarity, the 2012 extreme melt across Greenland provides an exceptional opportunity for new studies in broad interdisciplinary geophysical research.

Left dorsal premotor cortex and supramarginal gyrus complement each other during rapid action reprogramming

PubMed Central

Hartwigsen, Gesa; Bestmann, Sven; Ward, Nick S.; Woerbel, Saskia; Mastroeni, Claudia; Granert, Oliver; Siebner, Hartwig R.

2013-01-01

The ability to discard a prepared action plan in favor of an alternative action is critical when facing sudden environmental changes. We tested whether the functional contribution of left supramarginal gyrus (SMG) during action reprogramming depends on the functional integrity of left dorsal premotor cortex (PMd). Adopting a dual-site repetitive transcranial magnetic stimulation (rTMS) strategy, we first transiently disrupted PMd with “offline” 1Hz rTMS and then applied focal “online” rTMS to SMG whilst human subjects performed a spatially-precued reaction time task. Effective online rTMS of SMG but not sham rTMS of SMG increased errors when subjects had to reprogram their action in response to an invalid precue regardless of the type of preceding offline rTMS. This suggests that left SMG primarily contributes to the online updating of actions by suppressing invalidly prepared responses. Online rTMS of SMG additionally increased reaction times for correct responses in invalidly-precued trials, but only after offline rTMS of PMd. We infer that offline rTMS caused an additional dysfunction of PMd which increased the functional relevance of SMG for rapid activation of the correct response, and sensitized SMG to the disruptive effects of online rTMS. These results not only provide causal evidence that left PMd and SMG jointly contribute to action reprogramming, but also that the respective functional weight of these areas can be rapidly redistributed. This mechanism might constitute a generic feature of functional networks that allows for rapid functional compensation in response to focal dysfunctions. PMID:23152600

ARTIST: A fully automated artifact rejection algorithm for single-pulse TMS-EEG data.

PubMed

Wu, Wei; Keller, Corey J; Rogasch, Nigel C; Longwell, Parker; Shpigel, Emmanuel; Rolle, Camarin E; Etkin, Amit

2018-04-01

Concurrent single-pulse TMS-EEG (spTMS-EEG) is an emerging noninvasive tool for probing causal brain dynamics in humans. However, in addition to the common artifacts in standard EEG data, spTMS-EEG data suffer from enormous stimulation-induced artifacts, posing significant challenges to the extraction of neural information. Typically, neural signals are analyzed after a manual time-intensive and often subjective process of artifact rejection. Here we describe a fully automated algorithm for spTMS-EEG artifact rejection. A key step of this algorithm is to decompose the spTMS-EEG data into statistically independent components (ICs), and then train a pattern classifier to automatically identify artifact components based on knowledge of the spatio-temporal profile of both neural and artefactual activities. The autocleaned and hand-cleaned data yield qualitatively similar group evoked potential waveforms. The algorithm achieves a 95% IC classification accuracy referenced to expert artifact rejection performance, and does so across a large number of spTMS-EEG data sets (n = 90 stimulation sites), retains high accuracy across stimulation sites/subjects/populations/montages, and outperforms current automated algorithms. Moreover, the algorithm was superior to the artifact rejection performance of relatively novice individuals, who would be the likely users of spTMS-EEG as the technique becomes more broadly disseminated. In summary, our algorithm provides an automated, fast, objective, and accurate method for cleaning spTMS-EEG data, which can increase the utility of TMS-EEG in both clinical and basic neuroscience settings. © 2018 Wiley Periodicals, Inc.

The angular gyrus and visuospatial attention in decision-making under risk.

PubMed

Studer, Bettina; Cen, Danlu; Walsh, Vincent

2014-12-01

Recent neuroimaging studies on decision-making under risk indicate that the angular gyrus (AG) is sensitive to the probability and variance of outcomes during choice. A separate body of research has established the AG as a key area in visual attention. The current study used repetitive transcranial magnetic stimulation (rTMS) in healthy volunteers to test whether the causal contribution of the AG to decision-making is independent of or linked to the guidance of visuospatial attention. A within-subject design compared decision making on a laboratory gambling task under three conditions: following rTMS to the AG, following rTMS to the premotor cortex (PMC, as an active control condition) and without TMS. The task presented two different trial types, 'visual' and 'auditory' trials, which entailed a high versus minimal demand for visuospatial attention, respectively. Our results showed a systematic effect of rTMS to the AG upon decision-making behavior in visual trials. Without TMS and following rTMS to the control region, decision latencies reflected the odds of winning; this relationship was disrupted by rTMS to the AG. In contrast, no significant effects of rTMS to the AG (or to the PMC) upon choice behavior in auditory trials were found. Thus, rTMS to the AG affected decision-making only in the task condition requiring visuospatial attention. The current findings suggest that the AG contributes to decision-making by guiding attention to relevant information about reward and punishment in the visual environment. Copyright © 2014. Published by Elsevier Inc.

Not all transmembrane helices are born equal: Towards the extension of the sequence homology concept to membrane proteins

PubMed Central

2011-01-01

Background Sequence homology considerations widely used to transfer functional annotation to uncharacterized protein sequences require special precautions in the case of non-globular sequence segments including membrane-spanning stretches composed of non-polar residues. Simple, quantitative criteria are desirable for identifying transmembrane helices (TMs) that must be included into or should be excluded from start sequence segments in similarity searches aimed at finding distant homologues. Results We found that there are two types of TMs in membrane-associated proteins. On the one hand, there are so-called simple TMs with elevated hydrophobicity, low sequence complexity and extraordinary enrichment in long aliphatic residues. They merely serve as membrane-anchoring device. In contrast, so-called complex TMs have lower hydrophobicity, higher sequence complexity and some functional residues. These TMs have additional roles besides membrane anchoring such as intra-membrane complex formation, ligand binding or a catalytic role. Simple and complex TMs can occur both in single- and multi-membrane-spanning proteins essentially in any type of topology. Whereas simple TMs have the potential to confuse searches for sequence homologues and to generate unrelated hits with seemingly convincing statistical significance, complex TMs contain essential evolutionary information. Conclusion For extending the homology concept onto membrane proteins, we provide a necessary quantitative criterion to distinguish simple TMs (and a sufficient criterion for complex TMs) in query sequences prior to their usage in homology searches based on assessment of hydrophobicity and sequence complexity of the TM sequence segments. Reviewers This article was reviewed by Shamil Sunyaev, L. Aravind and Arcady Mushegian. PMID:22024092

Single Session Low Frequency Left Dorsolateral Prefrontal Transcranial Magnetic Stimulation Changes Neurometabolite Relationships in Healthy Humans

PubMed Central

Bridges, Nathaniel R.; McKinley, Richard A.; Boeke, Danielle; Sherwood, Matthew S.; Parker, Jason G.; McIntire, Lindsey K.; Nelson, Justin M.; Fletchall, Catherine; Alexander, Natasha; McConnell, Amanda; Goodyear, Chuck; Nelson, Jeremy T.

2018-01-01

Background: Dorsolateral prefrontal cortex (DLPFC) low frequency repetitive transcranial magnetic stimulation (LF-rTMS) has shown promise as a treatment and investigative tool in the medical and research communities. Researchers have made significant progress elucidating DLPFC LF-rTMS effects—primarily in individuals with psychiatric disorders. However, more efforts investigating underlying molecular changes and establishing links to functional and behavioral outcomes in healthy humans are needed. Objective: We aimed to quantify neuromolecular changes and relate these to functional changes following a single session of DLPFC LF-rTMS in healthy participants. Methods: Eleven participants received sham-controlled neuronavigated 1 Hz rTMS to the region most activated by a 7-letter Sternberg working memory task (SWMT) within the left DLPFC. We quantified SWMT performance, functional magnetic resonance activation and proton Magnetic resonance spectroscopy (MRS) neurometabolite measure changes before and after stimulation. Results: A single LF-rTMS session was not sufficient to change DLPFC neurometabolite levels and these changes did not correlate with DLPFC activation changes. Real rTMS, however, significantly altered neurometabolite correlations (compared to sham rTMS), both with baseline levels and between the metabolites themselves. Additionally, real rTMS was associated with diminished reaction time (RT) performance improvements and increased activation within the motor, somatosensory and lateral occipital cortices. Conclusion: These results show that a single session of LF-rTMS is sufficient to influence metabolite relationships and causes widespread activation in healthy humans. Investigating correlational relationships may provide insight into mechanisms underlying LF-rTMS. PMID:29632477

Transcranial magnetic stimulation for tinnitus: using the Tinnitus Functional Index to predict benefit in a randomized controlled trial.

PubMed

Theodoroff, Sarah M; Griest, Susan E; Folmer, Robert L

2017-02-09

Identifying characteristics associated with transcranial magnetic stimulation (TMS) benefit would offer insight as to why some individuals experience tinnitus relief following TMS treatment, whereas others do not. The purpose of this study was to use the Tinnitus Functional Index (TFI) and its subscales to identify specific factors associated with TMS treatment responsiveness. Individuals with bothersome tinnitus underwent 2000 pulses of 1-Hz TMS for 10 consecutive business days. The primary outcome measure was the TFI which yields a total score and eight individual subscale scores. Analyses were performed on baseline data from the active arm (n = 35) of a prospective, double-blind, randomized placebo-controlled clinical trial of TMS for tinnitus. Baseline total TFI score and three of the eight TFI subscales were useful in differentiating between responders and nonresponders to TMS intervention for tinnitus. These findings are not definitive, but suggest potential factors that contribute to perceived benefit following TMS. Overall, the main factor associated with TMS benefit was a higher tinnitus severity score for responders at baseline. The TFI subscales helped to clarify the factors that contributed to a higher severity score at baseline. Large-scale prospective research using systematic approaches is needed to identify and describe additional factors associated with tinnitus benefit following TMS. ClinicalTrials.gov, ID: NCT01104207 . Registered on 13 April 2010.

Analysing concurrent transcranial magnetic stimulation and electroencephalographic data: A review and introduction to the open-source TESA software.

PubMed

Rogasch, Nigel C; Sullivan, Caley; Thomson, Richard H; Rose, Nathan S; Bailey, Neil W; Fitzgerald, Paul B; Farzan, Faranak; Hernandez-Pavon, Julio C

2017-02-15

The concurrent use of transcranial magnetic stimulation with electroencephalography (TMS-EEG) is growing in popularity as a method for assessing various cortical properties such as excitability, oscillations and connectivity. However, this combination of methods is technically challenging, resulting in artifacts both during recording and following typical EEG analysis methods, which can distort the underlying neural signal. In this article, we review the causes of artifacts in EEG recordings resulting from TMS, as well as artifacts introduced during analysis (e.g. as the result of filtering over high-frequency, large amplitude artifacts). We then discuss methods for removing artifacts, and ways of designing pipelines to minimise analysis-related artifacts. Finally, we introduce the TMS-EEG signal analyser (TESA), an open-source extension for EEGLAB, which includes functions that are specific for TMS-EEG analysis, such as removing and interpolating the TMS pulse artifact, removing and minimising TMS-evoked muscle activity, and analysing TMS-evoked potentials. The aims of TESA are to provide users with easy access to current TMS-EEG analysis methods and to encourage direct comparisons of these methods and pipelines. It is hoped that providing open-source functions will aid in both improving and standardising analysis across the field of TMS-EEG research. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Add-on deep Transcranial Magnetic Stimulation (dTMS) for the treatment of chronic migraine: A preliminary study.

PubMed

Rapinesi, Chiara; Del Casale, Antonio; Scatena, Paola; Kotzalidis, Georgios D; Di Pietro, Simone; Ferri, Vittoria Rachele; Bersani, Francesco Saverio; Brugnoli, Roberto; Raccah, Ruggero Nessim; Zangen, Abraham; Ferracuti, Stefano; Orzi, Francesco; Girardi, Paolo; Sette, Giuliano

2016-06-03

Deep Transcranial Magnetic Stimulation (dTMS) can be an alternative treatment to relieve pain in chronic migraine (CM). The aim of this study was to evaluate the effect of high-frequency dTMS in add-on to standard treatment for CM in patients not responding to effective abortive or preventive drug treatment. We randomized 14 patients with International Classification of Headache Disorders, 3rd Edition (ICHD-3) treatment-resistant CM to add-on dTMS (n=7) or standard abortive or preventive antimigraine treatment (n=7). Three sessions of alternate day 10Hz dTMS consisting of 600 pulses in 10 trains were delivered to the dorsolateral prefrontal cortex (DLPFC), bilaterally, but with left hemisphere prevalence, for 12 sessions spread over one month. The add-on dTMS treatment was well tolerated. Patients treated with dTMS showed significant reduction of pain intensity, frequency of attacks, analgesic overuse, and depressive symptoms during treatment and one month later, compared to the month preceding treatment and at the same time-points compared to the control group. As compared to standard pharmacological treatment alone, add-on high-frequency dTMS of the bilateral DLPFC reduced the frequency and intensity of migraine attack, drug overuse, and depressive symptoms. This study supports the add-on dTMS treatment in treatment-resistant CM. Copyright © 2016. Published by Elsevier Ireland Ltd.

One-year follow up of patients with chronic tinnitus treated with left temporoparietal rTMS.

PubMed

Khedr, E M; Rothwell, J C; El-Atar, A

2009-03-01

Although there are a number of positive reports on the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) for treatment of tinnitus, there are few details about the duration of treatment effects or the relative efficiency of different rTMS protocols. Sixty six patients with chronic tinnitus were divided into four groups, receiving sham rTMS, 1, 10 and 25 Hz rTMS applied each day for 10 days over left temporoparietal cortex. They were followed up at 4 months and 1 year using the tinnitus questionnaire [Tinnitus Handicap Inventory(THI)] and self ratings of annoyance as well as measures of residual inhibition. A two factor anova revealed a significant 'rTMS' x 'time' interaction indicating that real and sham rTMS had different effects on the THI scale and annoyance of tinnitus (P = 0.026 and 0.046 respectively). After 1 year, the tinnitus was absent in one or both ears of 10 patients who had received real rTMS: one of these was in the 1 Hz group, four patients were in the 10 Hz group and five patients were in the 25 Hz group. Some patients show a lasting benefit at 1 year after 10 days of rTMS treatment. It appears that treatment at 10 or 25 Hz may be more beneficial than at 1 Hz, although more work is necessary to validate this conclusion.

Examining frontotemporal connectivity and rTMS in healthy controls: implications for auditory hallucinations in schizophrenia.

PubMed

Gromann, Paula M; Tracy, Derek K; Giampietro, Vincent; Brammer, Michael J; Krabbendam, Lydia; Shergill, Sukhwinder S

2012-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been shown to have clinically beneficial effects in altering the perception of auditory hallucinations (AH) in patients with schizophrenia. However, the mode of action is not clear. Recent neuroimaging findings indicate that rTMS has the potential to induce not only local effects but also changes in remote, functionally connected brain regions. Frontotemporal dysconnectivity has been proposed as a mechanism leading to psychotic symptoms in schizophrenia. The current study examines functional connectivity between temporal and frontal brain regions after rTMS and the implications for AH in schizophrenia. A connectivity analysis was conducted on the fMRI data of 11 healthy controls receiving rTMS, compared with 11 matched subjects receiving sham TMS, to the temporoparietal junction, before engaging in a task associated with robust frontotemporal activation. Compared to the control group, the rTMS group showed an altered frontotemporal connectivity with stronger connectivity between the right temporoparietal cortex and the dorsolateral prefrontal cortex and the angular gyrus. This finding provides preliminary evidence for the hypothesis that normalizing the functional connectivity between the temporoparietal and frontal brain regions may underlie the therapeutic effect of rTMS on AH in schizophrenia.

Effective elimination of liver cancer stem-like cells by CD90 antibody targeted thermosensitive magnetoliposomes

PubMed Central

Yang, Rui; An, Li Y.; Miao, Qin F.; Li, Feng M.; Han, Yong; Wang, Hui X.; Liu, Dang P.; Chen, Rong; Tang, Sha Q.

2016-01-01

Aim To investigate the use of thermosensitive magnetoliposomes (TMs) loaded with magnetic iron oxide (Fe3O4) and the anti-cancer stem cell marker CD90 (CD90@TMs) to target and kill CD90+ liver cancer stem cells (LCSCs). Methods The hepatocellular carcinoma cell line Huh7 was used to separate CD90+ LCSCs by magnetic-activated cell sorting. CD90@TMs was characterized and their ability to target CD90+ LCSCs was determined. Experiments were used to investigate whether CD90@TMs combined with magnetic hyperthermia could effectively eliminate CD90+ LCSCs. Results The present study demonstrated that CD90+ LCSCs with stem cells properties were successfully isolated. We also successfully prepared CD90@TMs that was almost spherical and uniform with an average diameter of 130±4.6 nm and determined that magnetic iron oxide could be incorporated and retained a superparamagnetic response. CD90@TMs showed good targeting and increased inhibition of CD90+ LCSCs in vitro and in vivo compared to TMs. Conclusion CD90@TMs can be used for controlled and targeted delivery of anticancer drugs, which may offer a promising alternative for HCC therapy. PMID:27145285

3D customized and flexible tactile sensor using a piezoelectric nanofiber mat and sandwich-molded elastomer sheets

NASA Astrophysics Data System (ADS)

Bit Lee, Han; Kim, Young Won; Yoon, Jonghun; Lee, Nak Kyu; Park, Suk-Hee

2017-04-01

We developed a skin-conformal flexible sensor in which three-dimensional (3D) free-form elastomeric sheets were harmoniously integrated with a piezoelectric nanofiber mat. The elastomeric sheets were produced by polydimethylsiloxane (PDMS) molding via using a 3D printed mold assembly, which was adaptively designed from 3D scanned skin surface geometry. The mold assembly, fabricated using a multi-material 3D printer, was composed of a pair of upper/lower mold parts and an interconnecting hinge, with material properties are characterized by different flexibilities. As a result of appropriate deformabilites of the upper mold part and hinge, the skin-conformal PDMS structures were successfully sandwich molded and demolded with good repeatability. An electrospun poly(vinylidene fluoride trifluoroethylene) nanofiber mat was prepared as the piezoelectric active layer and integrated with the 3D elastomeric parts. We confirmed that the highly responsive sensing performances of the 3D integrated sensor were identical to those of a flat sensor in terms of sensitivity and the linearity of the input-output relationship. The close 3D conformal skin contact of the flexible sensor enabled discernable perception of various scales of physical stimuli, such as tactile force and even minute skin deformation caused by the tester’s pulse. Collectively from the 3D scanning design to the practical application, our achievements can potentially meet the needs of tailored human interfaces in the field of wearable devices and human-like robots.

How can transcranial magnetic stimulation be used to causally manipulate memory representations in the human brain?

PubMed

Widhalm, Morgan L; Rose, Nathan S

2018-06-27

We present a focused review on the utility of transcranial magnetic stimulation (TMS) for modulating memory, with a particular focus on multimodal approaches in which TMS is paired with neuroimaging methods (electroencephalography and magnetic resonance imaging (MRI)) to manipulate and measure working memory processes. We contrast the utility of TMS for manipulating memory with other forms of noninvasive brain stimulation, as well as different forms of TMS including single-pulse, paired-pulse and repetitive TMS protocols. We discuss the potential for TMS to address fundamental cognitive neuroscience questions about the nature of memory processes and representations, while acknowledging the considerable variability of behavioral and neural outcomes in TMS studies. Also discussed are the limitations of this technology, current advancements that have helped to defray the impact of these limitations, and suggestions for future directions in research and methodology. This article is categorized under: Neuroscience > Clinical Neuroscience Neuroscience > Cognition Psychology > Memory. © 2018 Wiley Periodicals, Inc.

Low frequency rTMS over posterior parietal cortex impairs smooth pursuit eye tracking.

PubMed

Hutton, Samuel B; Weekes, Brendan S

2007-11-01

The role of the posterior parietal cortex in smooth pursuit eye movements remains unclear. We used low frequency repetitive transcranial magnetic stimulation (rTMS) to study the cognitive and neural systems involved in the control of smooth pursuit eye movements. Eighteen participants were tested on two separate occasions. On each occasion we measured smooth pursuit eye tracking before and after 6 min of 1 Hz rTMS delivered at 90% of motor threshold. Low frequency rTMS over the posterior parietal cortex led to a significant reduction in smooth pursuit velocity gain, whereas rTMS over the motor cortex had no effect on gain. We conclude that low frequency offline rTMS is a potentially useful tool with which to explore the cortical systems involved in oculomotor control.

Community-led Air Sensor Evaluation: New Tools for Citizen Scientists Fact Sheet

EPA Pesticide Factsheets

EPA has developed a guide and analysis tool for citizen scientists to evaluate the performance of low-cost sensors and interpret the data they collect to help citizen scientists interested in learning about local air quality.

Thermal management system options for high power space platforms

NASA Technical Reports Server (NTRS)

Sadunas, J. A.; Lehtinen, A.; Parish, R.

1985-01-01

Thermal Management System (TMS) design options for a high power (75kWe), low earth orbit, multimodule space platform were investigated. The approach taken was to establish a baseline TMS representative of current technology, and to make incremental improvements through successive subsystem trades that lead to a candidate TMS. The TMS trades included centralized and decentralized transport, single-phase and two-phase transport, alternate working fluids, liquid loop and heat pipe radiators, deployed fixed, body mounted and steerable radiators, and thermal storage. The subsystem options were evaluated against criteria such as weight, TMS power requirement, reliability, system isothermality penalty, and growth potential.

Computational electromagnetic methods for transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Gomez, Luis J.

Transcranial magnetic stimulation (TMS) is a noninvasive technique used both as a research tool for cognitive neuroscience and as a FDA approved treatment for depression. During TMS, coils positioned near the scalp generate electric fields and activate targeted brain regions. In this thesis, several computational electromagnetics methods that improve the analysis, design, and uncertainty quantification of TMS systems were developed. Analysis: A new fast direct technique for solving the large and sparse linear system of equations (LSEs) arising from the finite difference (FD) discretization of Maxwell's quasi-static equations was developed. Following a factorization step, the solver permits computation of TMS fields inside realistic brain models in seconds, allowing for patient-specific real-time usage during TMS. The solver is an alternative to iterative methods for solving FD LSEs, often requiring run-times of minutes. A new integral equation (IE) method for analyzing TMS fields was developed. The human head is highly-heterogeneous and characterized by high-relative permittivities (107). IE techniques for analyzing electromagnetic interactions with such media suffer from high-contrast and low-frequency breakdowns. The novel high-permittivity and low-frequency stable internally combined volume-surface IE method developed. The method not only applies to the analysis of high-permittivity objects, but it is also the first IE tool that is stable when analyzing highly-inhomogeneous negative permittivity plasmas. Design: TMS applications call for electric fields to be sharply focused on regions that lie deep inside the brain. Unfortunately, fields generated by present-day Figure-8 coils stimulate relatively large regions near the brain surface. An optimization method for designing single feed TMS coil-arrays capable of producing more localized and deeper stimulation was developed. Results show that the coil-arrays stimulate 2.4 cm into the head while stimulating 3.0 times less volume than Figure-8 coils. Uncertainty quantification (UQ): The location/volume/depth of the stimulated region during TMS is often strongly affected by variability in the position and orientation of TMS coils, as well as anatomical differences between patients. A surrogate model-assisted UQ framework was developed and used to statistically characterize TMS depression therapy. The framework identifies key parameters that strongly affect TMS fields, and partially explains variations in TMS treatment responses.

Action Verbs and the Primary Motor Cortex: A Comparative TMS Study of Silent Reading, Frequency Judgments, and Motor Imagery

ERIC Educational Resources Information Center

Tomasino, Barbara; Fink, Gereon R.; Sparing, Roland; Dafotakis, Manuel; Weiss, Peter H.

2008-01-01

Single pulse transcranial magnetic stimulation (TMS) was applied to the hand area of the left primary motor cortex or, as a control, to the vertex (STIMULATION: TMS[subscript M1] vs. TMS[subscript vertex]) while right-handed volunteers silently read verbs related to hand actions. We examined three different tasks and time points for stimulation…

Interhemispheric Connectivity Influences the Degree of Modulation of TMS-Induced Effects during Auditory Processing

PubMed Central

Andoh, Jamila; Zatorre, Robert J.

2011-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been shown to interfere with many components of language processing, including semantic, syntactic, and phonologic. However, not much is known about its effects on nonlinguistic auditory processing, especially its action on Heschl's gyrus (HG). We aimed to investigate the behavioral and neural basis of rTMS during a melody processing task, while targeting the left HG, the right HG, and the Vertex as a control site. Response times (RT) were normalized relative to the baseline-rTMS (Vertex) and expressed as percentage change from baseline (%RT change). We also looked at sex differences in rTMS-induced response as well as in functional connectivity during melody processing using rTMS and functional magnetic resonance imaging (fMRI). fMRI results showed an increase in the right HG compared with the left HG during the melody task, as well as sex differences in functional connectivity indicating a greater interhemispheric connectivity between left and right HG in females compared with males. TMS results showed that 10 Hz-rTMS targeting the right HG induced differential effects according to sex, with a facilitation of performance in females and an impairment of performance in males. We also found a differential correlation between the %RT change after 10 Hz-rTMS targeting the right HG and the interhemispheric functional connectivity between right and left HG, indicating that an increase in interhemispheric functional connectivity was associated with a facilitation of performance. This is the first study to report a differential rTMS-induced interference with melody processing depending on sex. In addition, we showed a relationship between the interference induced by rTMS on behavioral performance and the neural activity in the network connecting left and right HG, suggesting that the interhemispheric functional connectivity could determine the degree of modulation of behavioral performance. PMID:21811478

Transcranial magnetic stimulation of dorsolateral prefrontal cortex reduces cocaine use: A pilot study.

PubMed

Terraneo, Alberto; Leggio, Lorenzo; Saladini, Marina; Ermani, Mario; Bonci, Antonello; Gallimberti, Luigi

2016-01-01

Recent animal studies demonstrate that compulsive cocaine seeking strongly reduces prelimbic frontal cortex activity, while optogenetic stimulation of this brain area significantly inhibits compulsive cocaine seeking, providing a strong rationale for applying brain stimulation to reduce cocaine consumption. Thus, we employed repetitive transcranial magnetic stimulation (rTMS), to test if dorsolateral prefrontal cortex (DLPFC) stimulation might prevent cocaine use in humans. Thirty-two cocaine-addicted patients were randomly assigned to either the experimental group (rTMS) on the left DLPFC, or to a control group (pharmacological agents) during a 29-day study (Stage 1). This was followed by a 63-day follow-up (Stage 2), during which all participants were offered rTMS treatment. Amongst the patients who completed Stage 1, 16 were in the rTMS group (100%) and 13 in the control group (81%). No significant adverse events were noted. During Stage 1, there were a significantly higher number of cocaine-free urine drug tests in the rTMS group compared to control (p=0.004). Craving for cocaine was also significantly lower in the rTMS group compared to the controls (p=0.038). Out of 13 patients who completed Stage 1 in the control group, 10 patients received rTMS treatment during Stage 2 and showed significant improvement with favorable outcomes becoming comparable to those of the rTMS group. The present preliminary findings support the safety of rTMS in cocaine-addicted patients, and suggest its potential therapeutic role for rTMS-driven PFC stimulation in reducing cocaine use, providing a strong rationale for developing larger placebo-controlled studies. Trial name: Repetitive transcranial magnetic stimulation (rTMS) in cocaine abusers, URL:〈http://www.isrctn.com/ISRCTN15823943?q=&filters=&sort=&offset=8&totalResults=13530&page=1&pageSize=10&searchType=basic-search〉, ISRCTN15823943. Published by Elsevier B.V.

Clinical and electrophysiological impact of repetitive low-frequency transcranial magnetic stimulation on the sensory–motor network in patients with restless legs syndrome

PubMed Central

Cantone, Mariagiovanna; Aricò, Debora; Lanuzza, Bartolo; Cosentino, Filomena Irene Ilaria; Paci, Domenico; Papotto, Maurizio; Pennisi, Manuela; Bella, Rita; Pennisi, Giovanni; Paulus, Walter; Ferri, Raffaele

2018-01-01

Background: Based on the hyperexcitability and disinhibition observed in patients with restless legs syndrome (RLS) following transcranial magnetic stimulation (TMS), we conducted a study with low-frequency repetitive TMS (rTMS) over the primary motor (M1) and somatosensory cortical areas (S1) in patients with RLS. Methods: A total of 13 right-handed patients and 10 age-matched controls were studied using clinical scales and TMS. Measurements included resting motor threshold (rMT), motor-evoked potentials (MEPs), cortical silent period (CSP), and central motor conduction time (CMCT). A single evening session of rTMS (1 Hz, 20 trains, 50 stimuli each) was administered over the left M1, left S1, and sham stimulation over M1 in a random order. Clinical and TMS measures were repeated after each stimulation modality. Results: Baseline CSP was shorter in patients than in controls and remained shorter in patients for both motor and somatosensory stimulation. The patients reported a subjective improvement of both initiating and maintaining sleep the night after the rTMS over S1. Patients exhibited a decrease in rMT after rTMS of S1 only, although the effect was smaller than in controls. MEP latency and CMCT changed only in controls after stimulation. Sham stimulation was without effect on the observed variables. Conclusions: rTMS on S1-M1 connectivity alleviated the sensory–motor complaints of RLS patients. The TMS indexes of excitation and inhibition indicate an intracortical and corticospinal imbalance, mainly involving gamma-aminobutyric acid (GABA)ergic and glutamatergic circuitries, as well as an impairment of the short-term mechanisms of cortical plasticity. The rTMS-induced activation of the dorsal striatum with the consequent increase of dopamine release may have contributed to the clinical and neurophysiological outcome. PMID:29511386

The Impact of Diffusion Tensor Imaging Fiber Tracking of the Corticospinal Tract Based on Navigated Transcranial Magnetic Stimulation on Surgery of Motor-Eloquent Brain Lesions.

PubMed

Raffa, Giovanni; Conti, Alfredo; Scibilia, Antonino; Cardali, Salvatore Massimiliano; Esposito, Felice; Angileri, Filippo Flavio; La Torre, Domenico; Sindorio, Carmela; Abbritti, Rosaria Viola; Germanò, Antonino; Tomasello, Francesco

2017-11-29

Navigated transcranial magnetic stimulation (nTMS) enables preoperative mapping of the motor cortex (M1). The combination of nTMS with diffusion tensor imaging fiber tracking (DTI-FT) of the corticospinal tract (CST) has been described; however, its impact on surgery of motor-eloquent lesions has not been addressed. To analyze the impact of nTMS-based mapping on surgery of motor-eloquent lesions. In this retrospective case-control study, we reviewed the data of patients operated for suspected motor-eloquent lesions between 2012 and 2015. The patients underwent nTMS mapping of M1 and, from 2014, nTMS-based DTI-FT of the CST. The impact on the preoperative risk/benefit analysis, surgical strategy, craniotomy size, extent of resection (EOR), and outcome were compared with a control group. We included 35 patients who underwent nTMS mapping of M1 (group A), 35 patients who also underwent nTMS-based DTI-FT of the CST (group B), and a control group composed of 35 patients treated without nTMS (group C). The patients in groups A and B received smaller craniotomies (P = .01; P = .001), had less postoperative seizures (P = .02), and a better postoperative motor performance (P = .04) and Karnofsky Performance Status (P = .009) than the controls. Group B exhibited an improved risk/benefit analysis (P = .006), an increased EOR of nTMS-negative lesions in absence of preoperative motor deficits (P = .01), and less motor and Karnofsky Performance Status worsening in case of preoperative motor deficits (P = .02, P = .03) than group A. nTMS-based mapping enables a tailored surgical approach for motor-eloquent lesions. It may improve the risk/benefit analysis, EOR and outcome, particularly when nTMS-based DTI-FT is performed. Copyright © 2017 by the Congress of Neurological Surgeons

Multifocal repetitive TMS for motor and mood symptoms of Parkinson disease: A randomized trial.

PubMed

Brys, Miroslaw; Fox, Michael D; Agarwal, Shashank; Biagioni, Milton; Dacpano, Geraldine; Kumar, Pawan; Pirraglia, Elizabeth; Chen, Robert; Wu, Allan; Fernandez, Hubert; Wagle Shukla, Aparna; Lou, Jau-Shin; Gray, Zachary; Simon, David K; Di Rocco, Alessandro; Pascual-Leone, Alvaro

2016-11-01

To assess whether multifocal, high-frequency repetitive transcranial magnetic stimulation (rTMS) of motor and prefrontal cortex benefits motor and mood symptoms in patients with Parkinson disease (PD). Patients with PD and depression were enrolled in this multicenter, double-blind, sham-controlled, parallel-group study of real or realistic (electric) sham rTMS. Patients were randomized to 1 of 4 groups: bilateral M1 ( + sham dorsolateral prefrontal cortex [DLPFC]), DLPFC ( + sham M1), M1 + DLPFC, or double sham. The TMS course consisted of 10 daily sessions of 2,000 stimuli for the left DLPFC and 1,000 stimuli for each M1 (50 × 4-second trains of 40 stimuli at 10 Hz). Patients were evaluated at baseline, at 1 week, and at 1, 3, and 6 months after treatment. Primary endpoints were changes in motor function assessed with the Unified Parkinson's Disease Rating Scale-III and in mood with the Hamilton Depression Rating Scale at 1 month. Of the 160 patients planned for recruitment, 85 were screened, 61 were randomized, and 50 completed all study visits. Real M1 rTMS resulted in greater improvement in motor function than sham at the primary endpoint (p < 0.05). There was no improvement in mood in the DLPFC group compared to the double-sham group, as well as no benefit to combining M1 and DLPFC stimulation for either motor or mood symptoms. In patients with PD with depression, M1 rTMS is an effective treatment of motor symptoms, while mood benefit after 2 weeks of DLPFC rTMS is not better than sham. Targeting both M1 and DLPFC in each rTMS session showed no evidence of synergistic effects. NCT01080794. This study provides Class I evidence that in patients with PD with depression, M1 rTMS leads to improvement in motor function while DLPFC rTMS does not lead to improvement in depression compared to sham rTMS. © 2016 American Academy of Neurology.

Using a Double-Coil TMS Protocol to Assess Preparatory Inhibition Bilaterally.

PubMed

Vassiliadis, Pierre; Grandjean, Julien; Derosiere, Gerard; de Wilde, Ysaline; Quemener, Louise; Duque, Julie

2018-01-01

Transcranial magnetic stimulation (TMS) applied over the primary motor cortex (M1), elicits motor-evoked potentials (MEPs) in contralateral limb muscles which are valuable indicators of corticospinal excitability (CSE) at the time of stimulation. So far, most studies have used single-coil TMS over one M1, yielding MEPs in muscles of a single limb-usually the hand. However, tracking CSE in the two hands simultaneously would be useful in many contexts. We recently showed that, in the resting state, double-coil stimulation of the two M1 with a 1 ms inter-pulse interval (double-coil 1 ms TMS) elicits MEPs in both hands that are comparable to MEPs obtained using single-coil TMS. To further evaluate this new technique, we considered the MEPs elicited by double-coil 1 ms TMS in an instructed-delay choice reaction time task where a prepared response has to be withheld until an imperative signal is displayed. Single-coil TMS studies have repetitively shown that in this type of task, the motor system is transiently inhibited during the delay period, as evident from the broad suppression of MEP amplitudes. Here, we aimed at investigating whether a comparable inhibitory effect can be observed with MEPs elicited using double-coil 1 ms TMS. To do so, we compared the amplitude as well as the coefficient of variation (CV) of MEPs produced by double-coil 1 ms or single-coil TMS during action preparation. We observed that MEPs were suppressed (smaller amplitude) and often less variable (smaller CV) during the delay period compared to baseline. Importantly, these effects were equivalent whether single-coil or double-coil 1 ms TMS was used. This suggests that double-coil 1 ms TMS is a reliable tool to assess CSE, not only when subjects are at rest, but also when they are involved in a task, opening new research horizons for scientists interested in the corticospinal correlates of human behavior.

Using a Double-Coil TMS Protocol to Assess Preparatory Inhibition Bilaterally

PubMed Central

Vassiliadis, Pierre; Grandjean, Julien; Derosiere, Gerard; de Wilde, Ysaline; Quemener, Louise; Duque, Julie

2018-01-01

Transcranial magnetic stimulation (TMS) applied over the primary motor cortex (M1), elicits motor-evoked potentials (MEPs) in contralateral limb muscles which are valuable indicators of corticospinal excitability (CSE) at the time of stimulation. So far, most studies have used single-coil TMS over one M1, yielding MEPs in muscles of a single limb—usually the hand. However, tracking CSE in the two hands simultaneously would be useful in many contexts. We recently showed that, in the resting state, double-coil stimulation of the two M1 with a 1 ms inter-pulse interval (double-coil1 ms TMS) elicits MEPs in both hands that are comparable to MEPs obtained using single-coil TMS. To further evaluate this new technique, we considered the MEPs elicited by double-coil1 ms TMS in an instructed-delay choice reaction time task where a prepared response has to be withheld until an imperative signal is displayed. Single-coil TMS studies have repetitively shown that in this type of task, the motor system is transiently inhibited during the delay period, as evident from the broad suppression of MEP amplitudes. Here, we aimed at investigating whether a comparable inhibitory effect can be observed with MEPs elicited using double-coil1 ms TMS. To do so, we compared the amplitude as well as the coefficient of variation (CV) of MEPs produced by double-coil1 ms or single-coil TMS during action preparation. We observed that MEPs were suppressed (smaller amplitude) and often less variable (smaller CV) during the delay period compared to baseline. Importantly, these effects were equivalent whether single-coil or double-coil1 ms TMS was used. This suggests that double-coil1 ms TMS is a reliable tool to assess CSE, not only when subjects are at rest, but also when they are involved in a task, opening new research horizons for scientists interested in the corticospinal correlates of human behavior. PMID:29568258

Oxygen Plasma Effect on QCM Sensor Coated Polystyrene Film

NASA Astrophysics Data System (ADS)

Khusnah, N. F.; Sakti, S. P.; Santjojo, D. J. D. H.

2018-05-01

Hydrophobicity property of polystyrene (PS) thin film is one of the essential factors to be considered in the development of quartz crystal microbalance (QCM) biosensor using polystyrene as matrix layer. Many methods were developed to improve the immobilization rate of the biomolecule on the sensor surface without affecting the QCM essential works. Surface modification of the sensor surface aims to modify the physical and or chemical property of the surface. A straightforward method, the fast, environmentally-friendly, and low-cost solution to modify the sensor surface coated with polystyrene film is using oxygen plasma. In this experiment, the polystyrene film was spin-coated on both surface of QCM electrodes and then heated at 100 °C. The specimen is then placed for 5 min long in a chamber filled with oxygen plasma generated by 2 MHz RF-DC high-density plasma system. The relationship between DC-bias used and the changes in morphology properties of the coated film was characterized by Topography Measurement System (TMS) and Contact Angle Measurement. The electrical characteristic of QCM was also characterized using Impedance Analyzer. It was revealed that the contact angle of oxygen plasma treated film is changed and depicted the hydrophobic character. Also, there is an increasing resonance frequency of the sensor after oxygen plasma treatment indicates an etching mechanism occurs during plasma treatment.

Force/torque and tactile sensors for sensor-based manipulator control

NASA Technical Reports Server (NTRS)

Vanbrussel, H.; Belieen, H.; Bao, Chao-Ying

1989-01-01

The autonomy of manipulators, in space and in industrial environments, can be dramatically enhanced by the use of force/torque and tactile sensors. The development and future use of a six-component force/torque sensor for the Hermes Robot Arm (HERA) Basic End-Effector (BEE) is discussed. Then a multifunctional gripper system based on tactile sensors is described. The basic transducing element of the sensor is a sheet of pressure-sensitive polymer. Tactile image processing algorithms for slip detection, object position estimation, and object recognition are described.

Cognitive enhancing effects of rTMS administered to the prefrontal cortex in patients with depression: A systematic review and meta-analysis of individual task effects.

PubMed

Martin, Donel M; McClintock, Shawn M; Forster, Jane J; Lo, Tin Yan; Loo, Colleen K

2017-11-01

Repetitive transcranial magnetic stimulation (rTMS) is an approved therapeutic treatment of major depressive disorder and has increasing clinical use throughout the world. However, it remains unclear whether an rTMS course for depression may also produce cognitive enhancement. In a recent meta-analysis of sham-controlled randomized controlled studies (RCTs) conducted in patients with neuropsychiatric conditions, no evidence was found for generalized cognitive enhancing effects across cognitive domains with active compared to sham rTMS. Notwithstanding, there remains the possibility of cognitive effects following an rTMS course that are more highly specific, for example, in specific clinical conditions, or at the individual task level. This study aimed to determine whether a therapeutic rTMS course in patients with depression is associated with cognitive enhancing effects at the task level. A systematic review and meta-analysis of outcomes on individual neuropsychological tasks from sham-controlled RCTs where an rTMS course was administered to the dorsolateral prefrontal cortex (DLPFC) in patients with depression. Eighteen studies met the inclusion criteria. Active rTMS treatment showed no specific enhancing effects on the majority of cognitive tasks. Modest effect size improvements with active compared to sham rTMS treatment were found for performance on the Trail Making Test Parts A (g = 0.28, 95% CI = 0.06-0.50) and B (g = 0.26, 95% CI = 0.06-0.47). A therapeutic rTMS course administered to the prefrontal cortex for depression may produce modest cognitive enhancing effects specific to psychomotor speed, visual scanning, and set-shifting ability. © 2017 Wiley Periodicals, Inc.

Attention Modulates TMS-Locked Alpha Oscillations in the Visual Cortex.

PubMed

Herring, Jim D; Thut, Gregor; Jensen, Ole; Bergmann, Til O

2015-10-28

Cortical oscillations, such as 8-12 Hz alpha-band activity, are thought to subserve gating of information processing in the human brain. While most of the supporting evidence is correlational, causal evidence comes from attempts to externally drive ("entrain") these oscillations by transcranial magnetic stimulation (TMS). Indeed, the frequency profile of TMS-evoked potentials (TEPs) closely resembles that of oscillations spontaneously emerging in the same brain region. However, it is unclear whether TMS-locked and spontaneous oscillations are produced by the same neuronal mechanisms. If so, they should react in a similar manner to top-down modulation by endogenous attention. To test this prediction, we assessed the alpha-like EEG response to TMS of the visual cortex during periods of high and low visual attention while participants attended to either the visual or auditory modality in a cross-modal attention task. We observed a TMS-locked local oscillatory alpha response lasting several cycles after TMS (but not after sham stimulation). Importantly, TMS-locked alpha power was suppressed during deployment of visual relative to auditory attention, mirroring spontaneous alpha amplitudes. In addition, the early N40 TEP component, located at the stimulation site, was amplified by visual attention. The extent of attentional modulation for both TMS-locked alpha power and N40 amplitude did depend, with opposite sign, on the individual ability to modulate spontaneous alpha power at the stimulation site. We therefore argue that TMS-locked and spontaneous oscillations are of common neurophysiological origin, whereas the N40 TEP component may serve as an index of current cortical excitability at the time of stimulation. Copyright © 2015 Herring et al.

[Clinical applications of transcranial magnetic stimulation for the treatment of various neurological diseases].

PubMed

Tsuji, Sadatoshi

2005-11-01

Repetitive transcranial magnetic stimulation (rTMS) has been used as a potential therapeutic tool in various neurological and psychiatric diseases including depression, Parkinson disease, spinocerebellar degeneration, epilepsy, urinary incontinence, movement disorders, chronic pain, migraine and chronic tinnitus, etc. Several reports showed the therapeutic effects of rTMS as a treatment of depression and Parkinson disease (PD), whereas others found no significant effects. It is by now not yet fully understood whether rTMS has a therapeutic effect on those diseases. The controversy arises from the differences of the stimulation parameters and evaluation methods of the effects in those studies. The Japanese multi-center, double blinded, sham stimulation controlled trial in 85 patients with PD showed an efficacy in both the rTMS-treated and sham stimulated patients. This result does not prove the efficacy of the rTMS in PD; on the other hand, it does not rule out the efficacy. Possible mechanism of favorable effects of rTMS is related to increasing the release of dopamine in the mesolimbic and mesostriatal system. The other Japanese multi-center, double blinded, sham stimulation controlled trial in 99 patients with spinocerebellar degeneration revealed significant therapeutic effects of rTMS in 51 patients with SCA6. We studied the effects of rTMS on seizure susceptibility in rats which prevented the development of status epilepticus of pentylenetetrazol-induced convulsions. This finding suggests the possibility of therapeutic use of rTMS in epilepsy. Further studies should be performed aiming to reveal the optimal stimulation parameters, and are necessary to reveal the therapeutic role of the rTMS in neurological and psychiatric diseases.

1-Hz rTMS in the treatment of tinnitus: A sham-controlled, randomized multicenter trial.

PubMed

Landgrebe, Michael; Hajak, Göran; Wolf, Stefan; Padberg, Frank; Klupp, Philipp; Fallgatter, Andreas J; Polak, Thomas; Höppner, Jacqueline; Haker, Rene; Cordes, Joachim; Klenzner, Thomas; Schönfeldt-Lecuona, Carlos; Kammer, Thomas; Graf, Erika; Koller, Michael; Kleinjung, Tobias; Lehner, Astrid; Schecklmann, Martin; Pöppl, Timm B; Kreuzer, Peter; Frank, Elmar; Langguth, Berthold

Chronic tinnitus is a frequent, difficult to treat disease with high morbidity. This multicenter randomized, sham-controlled trial investigated the efficacy and safety of 1-Hz repetitive transcranial magnetic stimulation (rTMS) applied to the left temporal cortex in patients with chronic tinnitus. Tinnitus patients were randomized to receive 10 sessions of either real or sham 1-Hz-rTMS (2000 stimuli, 110% motor threshold) to the left temporal cortex. The primary outcome was the change in the sum score of the tinnitus questionnaire (TQ) of Goebel and Hiller from baseline to end of treatment. A total of 163 patients were enrolled in the study (real rTMS: 75; sham rTMS: 78). At day 12, the baseline mean of 43.1 TQ points in 71 patients assigned to real rTMS changed by -0.5 points; it changed by 0.5 points from a baseline of 42.1 in 75 patients randomized to sham rTMS (adjusted mean difference between groups: -1.0; 95.19% confidence interval: -3.2 to 1.2; p = 0.36). All secondary outcome measures including measures of depression and quality of life showed no significant differences either (p > 0.11). The number of participants with side-effects or adverse events did not differ between groups. Real 1-Hz-rTMS over the left temporal cortex was well tolerated but not superior compared with sham rTMS in improving tinnitus severity. These findings are in contrast to results from studies with smaller sample sizes and put the efficacy of this rTMS protocol for treatment of chronic tinnitus into question. Controlled Trials: http://www.isrctn.com/ISRCTN89848288. Copyright © 2017 Elsevier Inc. All rights reserved.

Combining functional neuroimaging with off-line brain stimulation: modulation of task-related activity in language areas.

PubMed

Andoh, Jamila; Paus, Tomás

2011-02-01

Repetitive TMS (rTMS) provides a noninvasive tool for modulating neural activity in the human brain. In healthy participants, rTMS applied over the language-related areas in the left hemisphere, including the left posterior temporal area of Wernicke (LTMP) and inferior frontal area of Broca, have been shown to affect performance on word recognition tasks. To investigate the neural substrate of these behavioral effects, off-line rTMS was combined with fMRI acquired during the performance of a word recognition task. Twenty right-handed healthy men underwent fMRI scans before and after a session of 10-Hz rTMS applied outside the magnetic resonance scanner. Functional magnetic resonance images were acquired during the performance of a word recognition task that used English or foreign-language words. rTMS was applied over the LTMP in one group of 10 participants (LTMP group), whereas the homologue region in the right hemisphere was stimulated in another group of 10 participants (RTMP group). Changes in task-related fMRI response (English minus foreign languages) and task performances (response time and accuracy) were measured in both groups and compared between pre-rTMS and post-rTMS. Our results showed that rTMS increased task-related fMRI response in the homologue areas contralateral to the stimulated sites. We also found an effect of rTMS on response time for the LTMP group only. These findings provide insights into changes in neural activity in cortical regions connected to the stimulated site and are consistent with a hypothesis raised in a previous review about the role of the homologue areas in the contralateral hemisphere for preserving behavior after neural interference.

Role of Repetitive Transcranial Magnetic Stimulation (rTMS) in Treatment of Addiction and Related Disorders: A Systematic Review.

PubMed

Makani, Ramkrishna; Pradhan, Basant; Shah, Umang; Parikh, Tapan

2017-11-29

Addiction and related disorders are devastating with their tremendous social, psychological, and physical consequences for which development of optimally effective treatments are long overdue. Repetitive transcranial magnetic stimulation (rTMS) is relatively safe and is becoming an emerging therapeutic tool for these conditions. This systematic review was conducted using PubMed, PsycINFO, PsychiatryOnline and Cochrane Library ranging from year 2001 to 2017. Our search retrieved 70 related articles of which, based on the Strength of Recommendation Taxonomy (SORT) guidelines, 33 indicated Level-1 study quality and class-B strength of recommendation for rTMS in nicotine addiction (effective in 218/289 subjects who received rTMS as found in 11 studies). Level-2/Class-B evidence was found for alcohol and cocaine addictions (Alcohol: effective in 126/193 subjects who received rTMS as found in 8 studies; Cocaine: effective in 86/128 subjects, as found in 5 studies). For food cravings, Level-3/Class-B evidence was noted (effective in 134/169, found in 7 studies). However, the evidence was limited to Level-3/Class-C for heroin (10/20 subjects received active rTMS, effective in 1 study), methamphetamine (33/48 subjects received active rTMS, effective in 2 studies), cannabis (18/18 subjects received active rTMS, effective in 1 study), and pathological gambling (31/31 subjects received active rTMS, effective in 2 studies). rTMS may serve as an emerging therapeutic option for addiction and related disorders. The major lacunae include important methodological limitations and dearth of knowledge about precise mechanism of action that need to be addressed in the future studies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effects of repetitive transcranial magnetic stimulation combined with sensory cueing on unilateral neglect in subacute patients with right hemispheric stroke: a randomized controlled study.

PubMed

Yang, Nicole Yh; Fong, Kenneth Nk; Li-Tsang, Cecilia Wp; Zhou, D

2017-09-01

To compare the effects of rTMS combined with sensory cueing, rTMS alone, and conventional rehabilitation on unilateral neglect, hemiplegic arm functions and performance of activities of daily living. A single-blinded randomized controlled trial. A convalescent hospital. Sixty inpatients with left unilateral neglect after stroke. Patients were randomly assigned to three groups: rTMS combined with sensory cueing, rTMS, and conventional rehabilitation alone. rTMS at 1 Hz was applied over P5 of the contralesional hemisphere while vibration cueing was emitted using a wristwatch device on the hemiplegic arm, five days per week for two weeks. The first two groups received the same dosage of conventional rehabilitation on top of their experimental interventions. Blinded assessments were administered at baseline, 2 weeks postintervention, and 6 weeks follow-up. Neglect and arm motor performance. Both rTMS combined with sensory cueing (99.6±33.0) and rTMS alone (88.2±28.7) significantly reduced unilateral neglect than conventional rehabilitation (72.7±33.1) when measured using the conventional subtests of the Behavioural Inattention Test, but the combination was better than rTMS alone. Hemiplegic arm functions and activities of daily living improved in all patients across the three groups but no significant differences were found between the groups. The combination of inhibitory P5-rTMS with sensory cueing was better than either rTMS or conventional rehabilitation alone in producing a stronger and long-lasting improvement in unilateral neglect, but the improvement was not associated with improved arm function or independence in activities of daily living.

Is the human mirror neuron system plastic? Evidence from a transcranial magnetic stimulation study.

PubMed

Mehta, Urvakhsh Meherwan; Waghmare, Avinash V; Thirthalli, Jagadisha; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

2015-10-01

Virtual lesions in the mirror neuron network using inhibitory low-frequency (1Hz) transcranial magnetic stimulation (TMS) have been employed to understand its spatio-functional properties. However, no studies have examined the influence of neuro-enhancement by using excitatory high-frequency (20Hz) repetitive transcranial magnetic stimulation (HF-rTMS) on these networks. We used three forms of TMS stimulation (HF-rTMS, single and paired pulse) to investigate whether the mirror neuron system facilitates the motor system during goal-directed action observation relative to inanimate motion (motor resonance), a marker of putative mirror neuron activity. 31 healthy individuals were randomized to receive single-sessions of true or sham HF-rTMS delivered to the left inferior frontal gyrus - a component of the human mirror system. Motor resonance was assessed before and after HF-rTMS using three TMS cortical reactivity paradigms: (a) 120% of resting motor threshold (RMT), (b) stimulus intensity set to evoke motor evoked potential of 1-millivolt amplitude (SI1mV) and (c) a short latency paired pulse paradigm. Two-way RMANOVA showed a significant group (true versus sham) X occasion (pre- and post-HF-rTMS motor resonance) interaction effect for SI1mV [F(df)=6.26 (1, 29), p=0.018] and 120% RMT stimuli [F(df)=7.01 (1, 29), p=0.013] indicating greater enhancement of motor resonance in the true HF-rTMS group than the sham-group. This suggests that HF-rTMS could adaptively modulate properties of the mirror neuron system. This neuro-enhancement effect is a preliminary step that can open translational avenues for novel brain stimulation therapeutics targeting social-cognition deficits in schizophrenia and autism. Copyright © 2015 Elsevier B.V. All rights reserved.

Time change of perceptual reversal of ambiguous figures by rTMS.

PubMed

Nojima, K; Ge, S; Katayama, Y; Iramina, K

2010-01-01

The aim of this study was to investigate the effect of stimulus frequency and number of pulses during rTMS (repetitive transcranial magnetic stimulation) on the phenomenon of perceptual reversal. Particularly, we focused on the temporal dynamics of perceptual reversal in the right SPL (superior parietal lobule), using the spinning wheel illusion. We measured the IRT (inter-reversal time) of perceptual reversal. To investigate whether stimulus frequency or the number of pulses is critical for the rTMS effect, we applied the following schedules over the right SPL and the right PTL (posterior temporal lobe): 0.25Hz 60 pulses, 0.25Hz 120pulses, 0.5Hz 120 pulses, and 1Hz 120 pulses biphasic rTMS at 90% of the resting motor threshold. As a control, we included a No-TMS condition. The results showed that rTMS with 0.25Hz 60 pulses over the right SPL caused shorter IRT. There were no significant differences between IRTs for rTMS with 0.25Hz 120 pulses, 0.5Hz 120 pulses or 1Hz 120 pulses over the right SPL. Comparing these results with those of a previous study, we found that an rTMS condition with 60 pulses causes shorter IRT; 240 pulses causes longer IRT; and 120 pulses does not change IRT. Therefore, when applying rTMS over the right SPL, the IRT of perceptual reversal is primarily affected by the number of pulses.

Functional magnetic resonance imaging and transcranial magnetic stimulation: effects of motor imagery, movement and coil orientation.

PubMed

Niyazov, D M; Butler, A J; Kadah, Y M; Epstein, C M; Hu, X P

2005-07-01

To compare fMRI activations during movement and motor imagery to corresponding motor evoked potential (MEP) maps obtained with the TMS coil in three different orientations. fMRI activations during executed (EM) and imagined (IM) movements of the index finger were compared to MEP maps of the first dorsal interosseus (FDI) muscle obtained with the TMS coil in anterior, posterior and lateral handle positions. To ensure spatial registration of fMRI and MEP maps, a special grid was used in both experiments. No statistically significant difference was found between the TMS centers of gravity (TMS CoG) obtained with the three coil orientations. There was a significant difference between fMRI centers of gravity during IMs (IM CoG) and EMs (EM CoG), with IM CoGs localized on average 10.3mm anterior to those of EMs in the precentral gyrus. Most importantly, the IM CoGs closely matched cortical projections of the TMS CoGs while the EM CoGs were on average 9.5mm posterior to the projected TMS CoGs. TMS motor maps are more congruent with fMRI activations during motor imagery than those during EMs. These findings are not significantly affected by changing orientation of the TMS coil. Our results suggest that the discrepancy between fMRI and TMS motor maps may be largely due to involvement of the somatosensory component in the EM task.

The Effects of rTMS Combined with Motor Training on Functional Connectivity in Alpha Frequency Band.

PubMed

Jin, Jing-Na; Wang, Xin; Li, Ying; Jin, Fang; Liu, Zhi-Peng; Yin, Tao

2017-01-01

It has recently been reported that repetitive transcranial magnetic stimulation combined with motor training (rTMS-MT) could improve motor function in post-stroke patients. However, the effects of rTMS-MT on cortical function using functional connectivity and graph theoretical analysis remain unclear. Ten healthy subjects were recruited to receive rTMS immediately before application of MT. Low frequency rTMS was delivered to the dominant hemisphere and non-dominant hand performed MT over 14 days. The reaction time of Nine-Hole Peg Test and electroencephalography (EEG) in resting condition with eyes closed were recorded before and after rTMS-MT. Functional connectivity was assessed by phase synchronization index (PSI), and subsequently thresholded to construct undirected graphs in alpha frequency band (8-13 Hz). We found a significant decrease in reaction time after rTMS-MT. The functional connectivity between the parietal and frontal cortex, and the graph theory statistics of node degree and efficiency in the parietal cortex increased. Besides the functional connectivity between premotor and frontal cortex, the degree and efficiency of premotor cortex showed opposite results. In addition, the number of connections significantly increased within inter-hemispheres and inter-regions. In conclusion, this study could be helpful in our understanding of how rTMS-MT modulates brain activity. The methods and results in this study could be taken as reference in future studies of the effects of rTMS-MT in stroke patients.

Effect of the stimulus frequency and pulse number of repetitive transcranial magnetic stimulation on the inter-reversal time of perceptual reversal on the right superior parietal lobule

NASA Astrophysics Data System (ADS)

Nojima, Kazuhisa; Ge, Sheng; Katayama, Yoshinori; Ueno, Shoogo; Iramina, Keiji

2010-05-01

The aim of this study is to investigate the effect of the stimulus frequency and pulses number of repetitive transcranial magnetic stimulation (rTMS) on the inter-reversal time (IRT) of perceptual reversal on the right superior parietal lobule (SPL). The spinning wheel illusion was used as the ambiguous figures stimulation in this study. To investigate the rTMS effect over the right SPL during perceptual reversal, 0.25 Hz 60 pulse, 1 Hz 60 pulse, 0.5 Hz 120 pulse, 1 Hz 120 pulse, and 1 Hz 240 pulse biphasic rTMS at 90% of resting motor threshold was applied over the right SPL and the right posterior temporal lobe (PTL), respectively. As a control, a no TMS was also conducted. It was found that rTMS on 0.25 Hz 60 pulse and 1 Hz 60 pulse applied over the right SPL caused shorter IRT. In contrast, it was found that rTMS on 1 Hz 240-pulse applied over the right SPL caused longer IRT. On the other hand, there is no significant difference between IRTs when the rTMS on 0.5 Hz 120 pulse and 1 Hz 120 pulse were applied over the right SPL. Therefore, the applying of rTMS over the right SPL suggests that the IRT of perceptual reversal is effected by the rTMS conditions such as the stimulus frequency and the number of pulses.

Detection of Bacillus and Stenotrophomonas species growing in an organic acid and endocrine-disrupting chemical-rich environment of distillery spent wash and its phytotoxicity.

PubMed

Chandra, Ram; Kumar, Vineet

2017-01-01

Sugarcane molasses-based distillery spent wash (DSW) is well known for its toxicity and complex mixture of various recalcitrant organic pollutants with acidic pH, but the chemical nature of these pollutants is unknown. This study revealed the presence of toxic organic acids (butanedioic acid bis(TMS)ester; 2-hydroxysocaproic acid; benzenepropanoic acid, α-[(TMS)oxy], TMS ester; vanillylpropionic acid, bis(TMS)), and other recalcitrant organic pollutants (2-furancarboxylic acid, 5-[[(TMS)oxy] methyl], TMS ester; benzoic acid 3-methoxy-4-[(TMS)oxy], TMS ester; and tricarballylic acid 3TMS), which are listed as endocrine-disrupting chemicals. In addition, several major heavy metals were detected, including Fe (163.947), Mn (4.556), Zn (2.487), and Ni (1.175 mg l -1 ). Bacterial community analysis by restriction fragment length polymorphism revealed that Bacillus and Stenotrophomonas were dominant autochthonous bacterial communities belonging to the phylum Firmicutes and γ-Proteobacteria, respectively. The presence of Bacillus and Stenotrophomonas species in highly acidic environments indicated its broad range adaptation. These findings indicated that these autochthonous bacterial communities were pioneer taxa for in situ remediation of this hazardous waste during ecological succession. Further, phytotoxicity assay of DSW with Phaseolus mungo L. and Triticum aestivum revealed that T. aestivum was more sensitive than P. mungo L. in the seed germination test. The results of this study may be useful for monitoring and toxicity assessment of sugarcane molasses-based distillery waste at disposal sites.

High-Frequency Repetitive Transcranial Magnetic Stimulation (rTMS) Improves Functional Recovery by Enhancing Neurogenesis and Activating BDNF/TrkB Signaling in Ischemic Rats

PubMed Central

Luo, Jing; Zheng, Haiqing; Zhang, Liying; Zhang, Qingjie; Li, Lili; Pei, Zhong; Hu, Xiquan

2017-01-01

Repetitive transcranial magnetic stimulation (rTMS) has rapidly become an attractive therapeutic approach for stroke. However, the mechanisms underlying this remain elusive. This study aimed to investigate whether high-frequency rTMS improves functional recovery mediated by enhanced neurogenesis and activation of brain-derived neurotrophic factor (BDNF)/tropomyosin-related kinase B (TrkB) pathway and to compare the effect of conventional 20 Hz rTMS and intermittent theta burst stimulation (iTBS) on ischemic rats. Rats after rTMS were sacrificed seven and 14 days after middle cerebral artery occlusion (MCAO), following evaluation of neurological function. Neurogenesis was measured using specific markers: Ki67, Nestin, doublecortin (DCX), NeuN and glial fibrillary acidic protein (GFAP), and the expression levels of BDNF were visualized by Western blotting and RT-PCR analysis. Both high-frequency rTMS methods significantly improved neurological function and reduced infarct volume. Moreover, 20 Hz rTMS and iTBS significantly promoted neurogenesis, shown by an increase of Ki67/DCX, Ki67/Nestin, and Ki67/NeuN-positive cells in the peri-infarct striatum. These beneficial effects were accompanied by elevated protein levels of BDNF and phosphorylated-TrkB. In conclusion, high-frequency rTMS improves functional recovery possibly by enhancing neurogenesis and activating BDNF/TrkB signaling pathway and conventional 20 Hz rTMS is better than iTBS at enhancing neurogenesis in ischemic rats. PMID:28230741

Dissociating the role of prefrontal and premotor cortices in controlling inhibitory mechanisms during motor preparation.

PubMed

Duque, Julie; Labruna, Ludovica; Verset, Sophie; Olivier, Etienne; Ivry, Richard B

2012-01-18

Top-down control processes are critical to select goal-directed actions in flexible environments. In humans, these processes include two inhibitory mechanisms that operate during response selection: one is involved in solving a competition between different response options, the other ensures that a selected response is initiated in a timely manner. Here, we evaluated the role of dorsal premotor cortex (PMd) and lateral prefrontal cortex (LPF) of healthy subjects in these two forms of inhibition by using an innovative transcranial magnetic stimulation (TMS) protocol combining repetitive TMS (rTMS) over PMd or LPF and a single pulse TMS (sTMS) over primary motor cortex (M1). sTMS over M1 allowed us to assess inhibitory changes in corticospinal excitability, while rTMS was used to produce transient disruption of PMd or LPF. We found that rTMS over LPF reduces inhibition associated with competition resolution, whereas rTMS over PMd decreases inhibition associated with response impulse control. These results emphasize the dissociable contributions of these two frontal regions to inhibitory control during motor preparation. The association of LPF with competition resolution is consistent with the role of this area in relatively abstract aspects of control related to goal maintenance, ensuring that the appropriate response is selected in a variable context. In contrast, the association of PMd with impulse control is consistent with the role of this area in more specific processes related to motor preparation and initiation.

Can a single pulse transcranial magnetic stimulation targeted to the motor cortex interrupt pain processing?

PubMed Central

Kisler, Lee-Bareket; Gurion, Ilan; Granovsky, Yelena; Sinai, Alon; Sprecher, Elliot; Shamay-Tsoory, Simone

2018-01-01

The modulatory role of the primary motor cortex (M1), reflected by an inhibitory effect of M1-stimulation on clinical pain, motivated us to deepen our understanding of M1’s role in pain modulation. We used Transcranial Magnetic Stimulation (TMS)-induced virtual lesion (VL) to interrupt with M1 activity during noxious heat pain. We hypothesized that TMS-VL will effect experimental pain ratings. Three VL protocols were applied consisting of single-pulse TMS to transiently interfere with right M1 activity: (1) VLM1- TMS applied to 11 subjects, 20 msec before the individual’s first pain-related M1 peak activation, as determined by source analysis (sLORETA), (2) VL-50 (N = 16; TMS applied 50 ms prior to noxious stimulus onset), and (3) VL+150 (N = 16; TMS applied 150 ms after noxious stimulus onset). Each protocol included 3 conditions ('pain-alone', ' TMS-VL', and ‘SHAM-VL’), each consisted of 30 noxious heat stimuli. Pain ratings were compared, in each protocol, for TMS-VL vs. SHAM-VL and vs. pain-alone conditions. Repeated measures analysis of variance, corrected for multiple comparisons revealed no significant differences in the pain ratings between the different conditions within each protocol. Therefore, our results from this exploratory study suggest that a single pulse TMS-induced VL that is targeted to M1 failed to interrupt experimental pain processing in the specific three stimulation timing examined here. PMID:29630681

Can a single pulse transcranial magnetic stimulation targeted to the motor cortex interrupt pain processing?

PubMed

Kisler, Lee-Bareket; Gurion, Ilan; Granovsky, Yelena; Sinai, Alon; Sprecher, Elliot; Shamay-Tsoory, Simone; Weissman-Fogel, Irit

2018-01-01

The modulatory role of the primary motor cortex (M1), reflected by an inhibitory effect of M1-stimulation on clinical pain, motivated us to deepen our understanding of M1's role in pain modulation. We used Transcranial Magnetic Stimulation (TMS)-induced virtual lesion (VL) to interrupt with M1 activity during noxious heat pain. We hypothesized that TMS-VL will effect experimental pain ratings. Three VL protocols were applied consisting of single-pulse TMS to transiently interfere with right M1 activity: (1) VLM1- TMS applied to 11 subjects, 20 msec before the individual's first pain-related M1 peak activation, as determined by source analysis (sLORETA), (2) VL-50 (N = 16; TMS applied 50 ms prior to noxious stimulus onset), and (3) VL+150 (N = 16; TMS applied 150 ms after noxious stimulus onset). Each protocol included 3 conditions ('pain-alone', ' TMS-VL', and 'SHAM-VL'), each consisted of 30 noxious heat stimuli. Pain ratings were compared, in each protocol, for TMS-VL vs. SHAM-VL and vs. pain-alone conditions. Repeated measures analysis of variance, corrected for multiple comparisons revealed no significant differences in the pain ratings between the different conditions within each protocol. Therefore, our results from this exploratory study suggest that a single pulse TMS-induced VL that is targeted to M1 failed to interrupt experimental pain processing in the specific three stimulation timing examined here.

Dissociating the role of prefrontal and premotor cortices in controlling inhibitory mechanisms during motor preparation

PubMed Central

Duque, Julie; Labruna, Ludovica; Verset, Sophie; Olivier, Etienne; Ivry, Richard B.

2012-01-01

Top-down control processes are critical to select goal-directed actions in flexible environments. In humans, these processes include two inhibitory mechanisms that operate during response selection: one is involved in solving a competition between different response options, the other ensures that a selected response is initiated timely. Here, we evaluated the role of dorsal premotor cortex (PMd) and lateral prefrontal cortex (LPF) of healthy subjects in these two forms of inhibition by using an innovative transcranial magnetic stimulation (TMS) protocol combining repetitive TMS (rTMS) over PMd or LPF and a single pulse TMS (sTMS) over primary motor cortex (M1). sTMS over M1 allowed us to assess inhibitory changes in corticospinal excitability, while rTMS was used to produce transient disruption of PMd or LPF. We found that rTMS over LPF reduces inhibition associated with competition resolution whereas rTMS over PMd decreases inhibition associated with response impulse control. These results emphasize the dissociable contributions of these two frontal regions to inhibitory control during motor preparation. The association of LPF with competition resolution is consistent with the role of this area in relatively abstract aspects of control related to goal maintenance, ensuring that the appropriate response is selected in a variable context. In contrast, the association of PMd with impulse control is consistent with the role of this area in more specific processes related to motor preparation and initiation. PMID:22262879

Safety of repetitive transcranial magnetic stimulation in patients with implanted cortical electrodes. An ex-vivo study and report of a case.

PubMed

Phielipp, Nicolás M; Saha, Utpal; Sankar, Tejas; Yugeta, Akihiro; Chen, Robert

2017-06-01

To evaluate the safety of repetitive transcranial magnetic stimulation (rTMS) in patients with implanted subdural cortical electrodes. We performed ex-vivo experiments to test the temperature, displacement and current induced in the electrodes with single pulse transcranial magnetic stimulation (TMS) from 10 to 100% of stimulator output and tested a typical rTMS protocol used in a clinical setting. We then used rTMS to the motor cortex to treat a patient with refractory post-herpetic neuralgia who had previously been implanted with a subdural motor cortical electrode for pain management. The rTMS protocol consisted of ten sessions of 2000 stimuli at 20Hz and 90% of resting motor threshold. The ex-vivo study showed an increase in the coil temperature of 2°C, a maximum induced charge density of 30.4μC/cm 2 /phase, and no electrode displacement with TMS. There was no serious adverse effect associated with rTMS treatment of the patient. Cortical tremor was observed in the intervals between trains of stimuli during one treatment session. TMS was safe in a patient with implanted Medtronic Resume II electrode (model 3587A) subdural cortical electrode. TMS may be used as a therapeutic, diagnostic or research tool in patients this type of with implanted cortical electrodes. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Versatile infrared refractive-index sensor based on surface plasmon resonance in graphene sheet

NASA Astrophysics Data System (ADS)

Bai, Yukun; Wang, Biao; Ma, Xiurong

2018-03-01

A reflection-type refractive-index sensor based on the surface plasmon resonance of graphene in the mid-infrared to terahertz regime is proposed. With a simple configuration, the sensor demonstrates high flexibilities for the gas and liquid samples sensing and achieves markedly improved figures of merit of 53.64 and 36.5 RIU - 1, respectively.

Wearable, Flexible, and Multifunctional Healthcare Device with an ISFET Chemical Sensor for Simultaneous Sweat pH and Skin Temperature Monitoring.

PubMed

Nakata, Shogo; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

2017-03-24

Real-time daily healthcare monitoring may increase the chances of predicting and diagnosing diseases in their early stages which, currently, occurs most frequently during medical check-ups. Next-generation noninvasive healthcare devices, such as flexible multifunctional sensor sheets designed to be worn on skin, are considered to be highly suitable candidates for continuous real-time health monitoring. For healthcare applications, acquiring data on the chemical state of the body, alongside physical characteristics such as body temperature and activity, are extremely important for predicting and identifying potential health conditions. To record these data, in this study, we developed a wearable, flexible sweat chemical sensor sheet for pH measurement, consisting of an ion-sensitive field-effect transistor (ISFET) integrated with a flexible temperature sensor: we intend to use this device as the foundation of a fully integrated, wearable healthcare patch in the future. After characterizing the performance, mechanical flexibility, and stability of the sensor, real-time measurements of sweat pH and skin temperature are successfully conducted through skin contact. This flexible integrated device has the potential to be developed into a chemical sensor for sweat for applications in healthcare and sports.

rTMS: A Treatment to Restore Function After Severe TBI

DTIC Science & Technology

2016-10-01

of rTMS-induced neurobehavioral effects measured with the Disability Rating Scale. Aim II will determine the presence, direction and sustainability...Aim IV addresses the need to confirm rTMS safety for severe TBI. 15. SUBJECT TERMS Disability Rating Scale (DRS), Neurobehavioral, Repetitive...rTMS sessions. The Disability Rating Scale (DRS) will be used at four time points to measure neurobehavioral recovery slopes. Net neural effects

Enhancement of human cognitive performance using transcranial magnetic stimulation (TMS)

PubMed Central

Luber, Bruce; Lisanby, and Sarah H.

2014-01-01

Here we review the usefulness of transcranial magnetic stimulation (TMS) in modulating cortical networks in ways that might produce performance enhancements in healthy human subjects. To date over sixty studies have reported significant improvements in speed and accuracy in a variety of tasks involving perceptual, motor, and executive processing. Two basic categories of enhancement mechanisms are suggested by this literature: direct modulation of a cortical region or network that leads to more efficient processing, and addition-by-subtraction, which is disruption of processing which competes or distracts from task performance. Potential applications of TMS cognitive enhancement, including research into cortical function, rehabilitation therapy in neurological and psychiatric illness, and accelerated skill acquisition in healthy individuals are discussed, as are methods of optimizing the magnitude and duration of TMS-induced performance enhancement, such as improvement of targeting through further integration of brain imaging with TMS. One technique, combining multiple sessions of TMS with concurrent TMS/task performance to induce Hebbian-like learning, appears to be promising for prolonging enhancement effects. While further refinements in the application of TMS to cognitive enhancement can still be made, and questions remain regarding the mechanisms underlying the observed effects, this appears to be a fruitful area of investigation that may shed light on the basic mechanisms of cognitive function and their therapeutic modulation. PMID:23770409

Transcranial Magnetic Stimulation to Address Mild Cognitive Impairment in the Elderly: A Randomized Controlled Study

PubMed Central

Drumond Marra, Hellen Livia; Myczkowski, Martin Luiz; Maia Memória, Cláudia; Arnaut, Débora; Leite Ribeiro, Philip; Sardinha Mansur, Carlos Gustavo; Lancelote Alberto, Rodrigo; Boura Bellini, Bianca; Alves Fernandes da Silva, Adriano; Ciampi de Andrade, Daniel; Teixeira, Manoel Jacobsen; Forlenza, Orestes Vicente; Marcolin, Marco Antonio

2015-01-01

Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique with potential to improve memory. Mild cognitive impairment (MCI), which still lacks a specific therapy, is a clinical syndrome associated with increased risk of dementia. This study aims to assess the effects of high-frequency repetitive TMS (HF rTMS) on everyday memory of the elderly with MCI. We conducted a double-blinded randomized sham-controlled trial using rTMS over the left dorsolateral prefrontal cortex (DLPFC). Thirty-four elderly outpatients meeting Petersen's MCI criteria were randomly assigned to receive 10 sessions of either active TMS or sham, 10 Hz rTMS at 110% of motor threshold, 2,000 pulses per session. Neuropsychological assessment at baseline, after the last session (10th) and at one-month follow-up, was applied. ANOVA on the primary efficacy measure, the Rivermead Behavioural Memory Test, revealed a significant group-by-time interaction (p = 0.05), favoring the active group. The improvement was kept after one month. Other neuropsychological tests were heterogeneous. rTMS at 10 Hz enhanced everyday memory in elderly with MCI after 10 sessions. These findings suggest that rTMS might be effective as a therapy for MCI and probably a tool to delay deterioration. PMID:26160997

Combining near-infrared spectroscopy with electroencephalography and repetitive transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Näsi, Tiina; Kotilahti, Kalle; Mäki, Hanna; Nissilä, Ilkka; Meriläinen, Pekka

2009-07-01

The objective of the study was to assess the usability of a near-infrared spectroscopy (NIRS) device in multimodal measurements. We combined NIRS with electroencephalography (EEG) to record hemodynamic responses and evoked potentials simultaneously, and with transcranial magnetic stimulation (TMS) to investigate hemodynamic responses to repetitive TMS (rTMS). Hemodynamic responses and visual evoked potentials (VEPs) to 3, 6, and 12 s stimuli consisting of pattern-reversing checkerboards were successfully recorded in the NIRS/EEG measurement, and ipsi- and contralateral hemodynamic responses to 0.5, 1, and 2 Hz rTMS in the NIRS/TMS measurement. In the NIRS/EEG measurements, the amplitudes of the hemodynamic responses increased from 3- to 6-s stimulus, but not from 6- to 12-s stimulus, and the VEPs showed peaks N75, P100, and N135. In the NIRS/TMS measurements, the 2-Hz stimulus produced the strongest hemodynamic responses compared to the 0.5- and 1-Hz stimuli. In two subjects oxyhemoglobin concentration decreased and in one increased as a consequence of the 2-Hz rTMS. To locate the origin of the measured NIRS responses, methods have to be developed to investigate TMS-induced scalp muscle contractions. In the future, multimodal measurements may prove useful in monitoring or treating diseases such as stroke or Alzheimer's disease.

Meta-Analysis of Oxaliplatin-Based Chemotherapy Combined With Traditional Medicines for Colorectal Cancer

PubMed Central

Chen, Menghua; May, Brian H.; Zhou, Iris W.; Xue, Charlie C. L.; Zhang, Anthony L.

2015-01-01

This meta-analysis evaluates the clinical evidence for the addition of traditional medicines (TMs) to oxaliplatin-based regimens for colorectal cancer (CRC) in terms of tumor response rate (TRR). Eight electronic databases were searched for randomized controlled trials of oxaliplatin-based chemotherapy combined with TMs compared to the same oxaliplatin-based regimen. Data on TRR from 42 randomized controlled trials were analyzed using Review Manager 5.1. Studies were conducted in China or Japan. Publication bias was not evident. The meta-analyses suggest that the combination of the TMs with oxaliplatin-based regimens increased TRR in the palliative treatment of CRC (risk ratio [RR] 1.31 [1.20-1.42], I2 = 0%). Benefits were evident for both injection products (RR 1.36 [1.18-1.57], I2 = 0%) and orally administered TMs (RR 1.27 [1.15-1.41], I2 = 0%). Further sensitivity analysis of specific plant-based TMs found that Paeonia, Curcuma, and Sophora produced consistently higher contributions to the RR results. Compounds in each of these TMs have shown growth-inhibitory effects in CRC cell-line studies. Specific combinations of TMs appeared to produce higher contributions to TRR than the TMs individually. Notable among these was the combination of Hedyotis, Astragalus, and Scutellaria. PMID:26254190

Improvements in symptoms following neuronavigated repetitive transcranial magnetic stimulation (rTMS) in severe and enduring anorexia nervosa: findings from two case studies.

PubMed

McClelland, Jessica; Bozhilova, Natali; Nestler, Steffen; Campbell, Iain C; Jacob, Shirabdi; Johnson-Sabine, Eric; Schmidt, Ulrike

2013-11-01

Advances in the treatment of anorexia nervosa (AN) are most likely to arise from targeted, brain-directed treatments, such as repetitive transcranial magnetic stimulation (rTMS). We describe findings from two individuals with treatment-resistant AN who received 19-20 sessions of neuronavigated, high frequency rTMS, applied to the left dorsolateral prefrontal cortex. Within-session measures assessed changes pre-rTMS, post-rTMS in subjective eating disorder (ED) experiences. Weight, ED symptoms and mood were assessed pre-treatment, post-treatment and at 1 month follow-up. In both cases, there was improvement in ED symptomatology and mood after 19-20 sessions of neuronavigated rTMS, and these changes persisted or continued to improve at follow-up. Within sessions, Patient A demonstrated a consistent reduction in subjective ED experiences, and Patient B a reduction in some ED related experiences. These findings suggest that rTMS has potential as an adjunct to the treatment of AN and deserves further study. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.

Safety study of high-frequency transcranial magnetic stimulation in patients with chronic stroke.

PubMed

Lomarev, M P; Kim, D Y; Richardson, S Pirio; Voller, B; Hallett, M

2007-09-01

Repetitive transcranial magnetic stimulation (rTMS) is a potential therapeutic tool to rehabilitate chronic stroke patients. In this study, the safety of high-frequency rTMS in stroke was investigated (Phase I). The safety of 20 and 25 Hz rTMS over the motor cortex (MC) of the affected hemisphere, with intensities of 110-130% of the motor threshold (MT), was evaluated using surface electromyography (EMG) of hand and arm muscles. Brief EMG bursts, possibly representing peripheral manifestations of after discharges, and spread of excitation to proximal muscles are considered to be associated with a high risk of seizure occurrence. These events were recorded after the rTMS trains. Neither increased MC excitability nor improved pinch force dynamometry was found after rTMS. Stimulation parameters for rTMS, which are safe for healthy volunteers, may lead to a higher risk for seizure occurrence in chronic stroke patients. rTMS at rates of 20 and 25 Hz using above threshold stimulation potentially increases the risk of seizures in patients with chronic stroke.

Resting state brain dynamics and its transients: a combined TMS-EEG study.

PubMed

Bonnard, Mireille; Chen, Sophie; Gaychet, Jérôme; Carrere, Marcel; Woodman, Marmaduke; Giusiano, Bernard; Jirsa, Viktor

2016-08-04

The brain at rest exhibits a spatio-temporally rich dynamics which adheres to systematic behaviours that persist in task paradigms but appear altered in disease. Despite this hypothesis, many rest state paradigms do not act directly upon the rest state and therefore cannot confirm hypotheses about its mechanisms. To address this challenge, we combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to study brain's relaxation toward rest following a transient perturbation. Specifically, TMS targeted either the medial prefrontal cortex (MPFC), i.e. part of the Default Mode Network (DMN) or the superior parietal lobule (SPL), involved in the Dorsal Attention Network. TMS was triggered by a given brain state, namely an increase in occipital alpha rhythm power. Following the initial TMS-Evoked Potential, TMS at MPFC enhances the induced occipital alpha rhythm, called Event Related Synchronisation, with a longer transient lifetime than TMS at SPL, and a higher amplitude. Our findings show a strong coupling between MPFC and the occipital alpha power. Although the rest state is organized around a core of resting state networks, the DMN functionally takes a special role among these resting state networks.

Research with rTMS in the treatment of aphasia

PubMed Central

Naeser, Margaret A.; Martin, Paula I; Treglia, Ethan; Ho, Michael; Kaplan, Elina; Bashir, Shahid; Hamilton, Roy; Coslett, H. Branch; Pascual-Leone, Alvaro

2013-01-01

This review of our research with rTMS to treat aphasia contains four parts: Part 1 reviews functional brain imaging studies related to recovery of language in aphasia with emphasis on nonfluent aphasia. Part 2 presents the rationale for using rTMS to treat nonfluent aphasia patients (based on results from functional imaging studies). Part 2 also reviews our current rTMS treatment protocol used with nonfluent aphasia patients, and our functional imaging results from overt naming fMRI scans, obtained pre- and post- a series of rTMS treatments. Part 3 presents results from a pilot study where rTMS treatments were followed immediately by constraint-induced language therapy (CILT). Part 4 reviews our diffusion tensor imaging (DTI) study that examined white matter connections between the horizontal, midportion of the arcuate fasciculus (hAF) to different parts within Broca’s area (pars triangularis, PTr; pars opercularis, POp), and the ventral premotor cortex (vPMC) in the RH and in the LH. Part 4 also addresses some of the possible mechanisms involved with improved naming and speech, following rTMS with nonfluent aphasia patients. PMID:20714075

Randomised sham-controlled study of high-frequency bilateral deep transcranial magnetic stimulation (dTMS) to treat adult attention hyperactive disorder (ADHD): Negative results.

PubMed

Paz, Yaniv; Friedwald, Keren; Levkovitz, Yeheal; Zangen, Abraham; Alyagon, Uri; Nitzan, Uri; Segev, Aviv; Maoz, Hagai; Koubi, May; Bloch, Yuval

2017-01-31

Recent studies support the possible effectiveness of repetitive transcranial magnetic stimulation (rTMS) as a treatment for attention deficit hyperactivity disorder (ADHD). The objective of this study was to evaluate the safety and possible efficacy of bilateral prefrontal deep rTMS for the treatment of adult ADHD. Twenty-six adult ADHD patients were randomised blindly to sham or actual deep TMS (dTMS). Twenty daily sessions were conducted using the bilateral H5 dTMS coil (Brainsway, IL) in order to stimulate the prefrontal cortex at 120% of the motor threshold at high frequency. For assessment, Conners' Adult ADHD Rating Scale questionnaire and a computerised continuous performance test, Test of Variables of Attention, were used. No differences in clinical outcomes were detected between the actual dTMS and sham groups. The presented evidence does not support the utility of bilateral prefrontal stimulation to treat adult ADHD. Due to the small sample size, caution must be exercised in interpreting our preliminary findings.

An embedded multi-core parallel model for real-time stereo imaging

NASA Astrophysics Data System (ADS)

He, Wenjing; Hu, Jian; Niu, Jingyu; Li, Chuanrong; Liu, Guangyu

2018-04-01

The real-time processing based on embedded system will enhance the application capability of stereo imaging for LiDAR and hyperspectral sensor. The task partitioning and scheduling strategies for embedded multiprocessor system starts relatively late, compared with that for PC computer. In this paper, aimed at embedded multi-core processing platform, a parallel model for stereo imaging is studied and verified. After analyzing the computing amount, throughout capacity and buffering requirements, a two-stage pipeline parallel model based on message transmission is established. This model can be applied to fast stereo imaging for airborne sensors with various characteristics. To demonstrate the feasibility and effectiveness of the parallel model, a parallel software was designed using test flight data, based on the 8-core DSP processor TMS320C6678. The results indicate that the design performed well in workload distribution and had a speed-up ratio up to 6.4.

Interhemispheric compensation: a hypothesis of TMS-induced effects on language-related areas.

PubMed

Andoh, Jamila; Martinot, Jean-Luc

2008-06-01

Repetitive transcranial magnetic stimulation (rTMS) applied over brain regions responsible for language processing is used to curtail potentially auditory hallucinations in schizophrenia patients and to investigate the functional organisation of language-related areas. Variability of effects is, however, marked across studies and between subjects. Furthermore, the mechanisms of action of rTMS are poorly understood. Here, we reviewed different factors related to the structural and functional organisation of the brain that might influence rTMS-induced effects. Then, by analogy with aphasia studies, and the plastic-adaptive changes in both the left and right hemispheres following aphasia recovery, a hypothesis is proposed about rTMS mechanisms over language-related areas (e.g. Wernicke, Broca). We proposed that the local interference induced by rTMS in language-related areas might be analogous to aphasic stroke and might lead to a functional reorganisation in areas connected to the virtual lesion for language recovery.

A Novel Transcranial Magnetic Stimulator Inducing Near Rectangular Pulses with Controllable Pulse Width (cTMS)

PubMed Central

Jalinous, Reza; Lisanby, Sarah H.

2013-01-01

A novel transcranial magnetic stimulation (TMS) device with controllable pulse width (PW) and near rectangular pulse shape (cTMS) is described. The cTMS device uses an insulated gate bipolar transistor (IGBT) with appropriate snubbers to switch coil currents up to 7 kA, enabling PW control from 5 μs to over 100 μs. The near-rectangular induced electric field pulses use 22–34% less energy and generate 67–72% less coil heating compared to matched conventional cosine pulses. CTMS is used to stimulate rhesus monkey motor cortex in vivo with PWs of 20 to 100 μs, demonstrating the expected decrease of threshold pulse amplitude with increasing PW. The technological solutions used in the cTMS prototype can expand functionality, and reduce power consumption and coil heating in TMS, enhancing its research and therapeutic applications. PMID:18232369

Concurrent application of TMS and near-infrared optical imaging: methodological considerations and potential artifacts

PubMed Central

Parks, Nathan A.

2013-01-01

The simultaneous application of transcranial magnetic stimulation (TMS) with non-invasive neuroimaging provides a powerful method for investigating functional connectivity in the human brain and the causal relationships between areas in distributed brain networks. TMS has been combined with numerous neuroimaging techniques including, electroencephalography (EEG), functional magnetic resonance imaging (fMRI), and positron emission tomography (PET). Recent work has also demonstrated the feasibility and utility of combining TMS with non-invasive near-infrared optical imaging techniques, functional near-infrared spectroscopy (fNIRS) and the event-related optical signal (EROS). Simultaneous TMS and optical imaging affords a number of advantages over other neuroimaging methods but also involves a unique set of methodological challenges and considerations. This paper describes the methodology of concurrently performing optical imaging during the administration of TMS, focusing on experimental design, potential artifacts, and approaches to controlling for these artifacts. PMID:24065911

A practical guide to diagnostic transcranial magnetic stimulation: Report of an IFCN committee

PubMed Central

Groppa, S.; Oliviero, A.; Eisen, A.; Quartarone, A.; Cohen, L.G.; Mall, V.; Kaelin-Lang, A.; Mima, T.; Rossi, S.; Thickbroom, G.W.; Rossini, P.M.; Ziemann, U.; Valls-Solé, J.; Siebner, H.R.

2016-01-01

Transcranial magnetic stimulation (TMS) is an established neurophysiological tool to examine the integrity of the fast-conducting corticomotor pathways in a wide range of diseases associated with motor dysfunction. This includes but is not limited to patients with multiple sclerosis, amyotrophic lateral sclerosis, stroke, movement disorders, disorders affecting the spinal cord, facial and other cranial nerves. These guidelines cover practical aspects of TMS in a clinical setting. We first discuss the technical and physiological aspects of TMS that are relevant for the diagnostic use of TMS. We then lay out the general principles that apply to a standardized clinical examination of the fast-conducting corticomotor pathways with single-pulse TMS. This is followed by a detailed description of how to examine corticomotor conduction to the hand, leg, trunk and facial muscles in patients. Additional sections cover safety issues, the triple stimulation technique, and neuropediatric aspects of TMS. PMID:22349304

Investigating dynamical information transfer in the brain following a TMS pulse: Insights from structural architecture.

PubMed

Amico, Enrico; Van Mierlo, Pieter; Marinazzo, Daniele; Laureys, Steven

2015-01-01

Transcranial magnetic stimulation (TMS) has been used for more than 20 years to investigate connectivity and plasticity in the human cortex. By combining TMS with high-density electroencephalography (hd-EEG), one can stimulate any cortical area and measure the effects produced by this perturbation in the rest of the cerebral cortex. The purpose of this paper is to investigate changes of information flow in the brain after TMS from a functional and structural perspective, using multimodal modeling of source reconstructed TMS/hd-EEG recordings and DTI tractography. We prove how brain dynamics induced by TMS is constrained and driven by its structure, at different spatial and temporal scales, especially when considering cross-frequency interactions. These results shed light on the function-structure organization of the brain network at the global level, and on the huge variety of information contained in it.

The hydrogen sulfide metabolite trimethylsulfonium is found in human urine

NASA Astrophysics Data System (ADS)

Lajin, Bassam; Francesconi, Kevin A.

2016-06-01

Hydrogen sulfide is the third and most recently discovered gaseous signaling molecule following nitric oxide and carbon monoxide, playing important roles both in normal physiological conditions and disease progression. The trimethylsulfonium ion (TMS) can result from successive methylation reactions of hydrogen sulfide. No report exists so far about the presence or quantities of TMS in human urine. We developed a method for determining TMS in urine using liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-QQQ), and applied the method to establish the urinary levels of TMS in a group of human volunteers. The measured urinary levels of TMS were in the nanomolar range, which is commensurate with the steady-state tissue concentrations of hydrogen sulfide previously reported in the literature. The developed method can be used in future studies for the quantification of urinary TMS as a potential biomarker for hydrogen sulfide body pools.

Biological and chemical sensors based on graphene materials.

PubMed

Liu, Yuxin; Dong, Xiaochen; Chen, Peng

2012-03-21

Owing to their extraordinary electrical, chemical, optical, mechanical and structural properties, graphene and its derivatives have stimulated exploding interests in their sensor applications ever since the first isolation of free-standing graphene sheets in year 2004. This article critically and comprehensively reviews the emerging graphene-based electrochemical sensors, electronic sensors, optical sensors, and nanopore sensors for biological or chemical detection. We emphasize on the underlying detection (or signal transduction) mechanisms, the unique roles and advantages of the used graphene materials. Properties and preparations of different graphene materials, their functionalizations are also comparatively discussed in view of sensor development. Finally, the perspective and current challenges of graphene sensors are outlined (312 references).

The compensatory dynamic of inter-hemispheric interactions in visuospatial attention revealed using rTMS and fMRI.

PubMed

Plow, Ela B; Cattaneo, Zaira; Carlson, Thomas A; Alvarez, George A; Pascual-Leone, Alvaro; Battelli, Lorella

2014-01-01

A balance of mutual tonic inhibition between bi-hemispheric posterior parietal cortices is believed to play an important role in bilateral visual attention. However, experimental support for this notion has been mainly drawn from clinical models of unilateral damage. We have previously shown that low-frequency repetitive TMS (rTMS) over the intraparietal sulcus (IPS) generates a contralateral attentional deficit in bilateral visual tracking. Here, we used functional magnetic resonance imaging (fMRI) to study whether rTMS temporarily disrupts the inter-hemispheric balance between bilateral IPS in visual attention. Following application of 1 Hz rTMS over the left IPS, subjects performed a bilateral visual tracking task while their brain activity was recorded using fMRI. Behaviorally, tracking accuracy was reduced immediately following rTMS. Areas ventro-lateral to left IPS, including inferior parietal lobule (IPL), lateral IPS (LIPS), and middle occipital gyrus (MoG), showed decreased activity following rTMS, while dorsomedial areas, such as Superior Parietal Lobule (SPL), Superior occipital gyrus (SoG), and lingual gyrus, as well as middle temporal areas (MT+), showed higher activity. The brain activity of the homologues of these regions in the un-stimulated, right hemisphere was reversed. Interestingly, the evolution of network-wide activation related to attentional behavior following rTMS showed that activation of most occipital synergists adaptively compensated for contralateral and ipsilateral decrement after rTMS, while activation of parietal synergists, and SoG remained competing. This pattern of ipsilateral and contralateral activations empirically supports the hypothesized loss of inter-hemispheric balance that underlies clinical manifestation of visual attentional extinction.

A novel approach for monitoring writing interferences during navigated transcranial magnetic stimulation mappings of writing related cortical areas.

PubMed

Rogić Vidaković, Maja; Gabelica, Dragan; Vujović, Igor; Šoda, Joško; Batarelo, Nikolina; Džimbeg, Andrija; Zmajević Schönwald, Marina; Rotim, Krešimir; Đogaš, Zoran

2015-11-30

It has recently been shown that navigated repetitive transcranial magnetic stimulation (nTMS) is useful in preoperative neurosurgical mapping of motor and language brain areas. In TMS mapping of motor cortices the evoked responses can be quantitatively monitored by electromyographic (EMG) recordings. No such setup exists for monitoring of writing during nTMS mappings of writing related cortical areas. We present a novel approach for monitoring writing during nTMS mappings of motor writing related cortical areas. To our best knowledge, this is the first demonstration of quantitative monitoring of motor evoked responses from hand by EMG, and of pen related activity during writing with our custom made pen, together with the application of chronometric TMS design and patterned protocol of rTMS. The method was applied in four healthy subjects participating in writing during nTMS mapping of the premotor cortical area corresponding to BA 6 and close to the superior frontal sulcus. The results showed that stimulation impaired writing in all subjects. The corresponding spectra of measured signal related to writing movements was observed in the frequency band 0-20 Hz. Magnetic stimulation affected writing by suppressing normal writing frequency band. The proposed setup for monitoring of writing provides additional quantitative data for monitoring and the analysis of rTMS induced writing response modifications. The setup can be useful for investigation of neurophysiologic mechanisms of writing, for therapeutic effects of nTMS, and in preoperative mapping of language cortical areas in patients undergoing brain surgery. Copyright © 2015 Elsevier B.V. All rights reserved.

Repetitive transcranial magnetic stimulation for clinical applications in neurological and psychiatric disorders: an overview.

PubMed

Machado, Sergio; Arias-Carrión, Oscar; Paes, Flávia; Vieira, Renata Teles; Caixeta, Leonardo; Novaes, Felipe; Marinho, Tamires; Almada, Leonardo Ferreira; Silva, Adriana Cardoso; Nardi, Antonio Egidio

2013-10-01

Neurological and psychiatric disorders are characterized by several disabling symptoms for which effective, mechanism-based treatments remain elusive. Consequently, more advanced non-invasive therapeutic methods are required. A method that may modulate brain activity and be viable for use in clinical practice is repetitive transcranial magnetic stimulation (rTMS). It is a non-invasive procedure whereby a pulsed magnetic field stimulates electrical activity in the brain. Here, we focus on the basic foundation of rTMS, the main stimulation parametters, the factors that influence individual responses to rTMS and the experimental advances of rTMS that may become a viable clinical application to treat neurological and psychiatric disorders. The findings showed that rTMS can improve some symptoms associated with these conditions and might be useful for promoting cortical plasticity in patients with neurological and psychiatric disorders. However, these changes are transient and it is premature to propose these applications as realistic therapeutic options, even though the rTMS technique has been evidenced as a potential modulator of sensorimotor integration and neuroplasticity. Functional imaging of the region of interest could highlight the capacity of rTMS to bring about plastic changes of the cortical circuitry and hint at future novel clinical interventions. Thus, we recommend that further studies clearly determine the role of rTMS in the treatment of these conditions. Finally, we must remember that however exciting the neurobiological mechanisms might be, the clinical usefulness of rTMS will be determined by its ability to provide patients with neurological and psychiatric disorders with safe, long-lasting and substantial improvements in quality of life.

Pain relief by rTMS: differential effect of current flow but no specific action on pain subtypes.

PubMed

André-Obadia, N; Mertens, P; Gueguen, A; Peyron, R; Garcia-Larrea, L

2008-09-09

To assess, against placebo, the pain-relieving effects of high-rate repetitive transcranial magnetic stimulation (rTMS) on neuropathic pain. Double-blind, randomized, cross-over study of high-rate rTMS against placebo in 28 patients. The effect of a change in coil orientation (posteroanterior vs lateromedial) on different subtypes of neuropathic pain was further tested in a subset of 16 patients. Pain relief was evaluated daily during 1 week. High-frequency, posteroanterior rTMS decreased pain scores significantly more than placebo. Posteroanterior rTMS also outmatched placebo in a score combining subjective (pain relief, quality of life) and objective (rescue drug intake) criteria of treatment benefit. Changing the orientation of the coil from posteroanterior to lateromedial did not yield any significant pain relief. The analgesic effects of posteroanterior rTMS lasted for approximately 1 week. The pain-relieving effects were observed exclusively on global scores reflecting the most distressing type of pain in each patient. Conversely, rTMS did not modify specifically any of the pain subscores that were separately tested (ongoing, paroxysmal, stimulus-evoked, or disesthesic pain). Posteroanterior repetitive transcranial magnetic stimulation (rTMS) was more effective than both placebo and lateromedial rTMS. When obtained, pain relief was not specific of any particular submodality, but rather reduced the global pain sensation whatever its type. This is in accord with recent models of motor cortex neurostimulation, postulating that its analgesic effects may derive in part from modulation of the affective appraisal of pain, rather than a decrease of its sensory components.

A single session of repetitive transcranial magnetic stimulation of the prefrontal cortex reduces cue-induced craving in patients with gambling disorder.

PubMed

Gay, A; Boutet, C; Sigaud, T; Kamgoue, A; Sevos, J; Brunelin, J; Massoubre, C

2017-03-01

Gambling disorder (GD) is common and disabling addictive disorder. In patients with substance use disorders, the application of repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) offers promise to alleviate craving. We hypothesized that applying real compared to sham rTMS over the left DLPFC would reduce gambling craving in patients with GD. In a randomized sham-controlled crossover design, 22 treatment-seeking patients with GD received real or sham treatment with high frequency rTMS over the left DLPFC followed a week later by the other type of treatment. Before and after each rTMS session, participants rated their gambling craving (from 0 to 100) before and after viewing a gambling video used as a cue. We used the Yale-Brown Obsessive Compulsive Scale adapted for Pathological Gambling to assess gambling behavior before and 7 days after each rTMS session. As compared to sham (mean +0.74; standard deviation±3.03), real rTMS significantly decreased cue-induced craving (-2.12±3.39; F (1,19) =4.87; P=0.04; partial η 2 =0.05; 95% CI: 0.00-0.21). No significant effect of rTMS was observed on gambling behavior. Patients with GD reported decreased cue-induced craving following a single session of high frequency rTMS applied over the left DLPFC. Further large randomized controlled studies are needed to determine the usefulness of rTMS in GD. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Non-invasive mapping of bilateral motor speech areas using navigated transcranial magnetic stimulation and functional magnetic resonance imaging.

PubMed

Könönen, Mervi; Tamsi, Niko; Säisänen, Laura; Kemppainen, Samuli; Määttä, Sara; Julkunen, Petro; Jutila, Leena; Äikiä, Marja; Kälviäinen, Reetta; Niskanen, Eini; Vanninen, Ritva; Karjalainen, Pasi; Mervaala, Esa

2015-06-15

Navigated transcranial magnetic stimulation (nTMS) is a modern precise method to activate and study cortical functions noninvasively. We hypothesized that a combination of nTMS and functional magnetic resonance imaging (fMRI) could clarify the localization of functional areas involved with motor control and production of speech. Navigated repetitive TMS (rTMS) with short bursts was used to map speech areas on both hemispheres by inducing speech disruption during number recitation tasks in healthy volunteers. Two experienced video reviewers, blinded to the stimulated area, graded each trial offline according to possible speech disruption. The locations of speech disrupting nTMS trials were overlaid with fMRI activations of word generation task. Speech disruptions were produced on both hemispheres by nTMS, though there were more disruptive stimulation sites on the left hemisphere. Grade of the disruptions varied from subjective sensation to mild objectively recognizable disruption up to total speech arrest. The distribution of locations in which speech disruptions could be elicited varied among individuals. On the left hemisphere the locations of disturbing rTMS bursts with reviewers' verification followed the areas of fMRI activation. Similar pattern was not observed on the right hemisphere. The reviewer-verified speech disruptions induced by nTMS provided clinically relevant information, and fMRI might explain further the function of the cortical area. nTMS and fMRI complement each other, and their combination should be advocated when assessing individual localization of speech network. Copyright © 2015 Elsevier B.V. All rights reserved.

Translational Neuromodulation: Approximating Human Transcranial Magnetic Stimulation Protocols In Rats

PubMed Central

Vahabzadeh-Hagh, Andrew M.; Muller, Paul A.; Gersner, Roman; Zangen, Abraham; Rotenberg, Alexander

2015-01-01

Objective Transcranial magnetic stimulation (TMS) is a well-established clinical protocol with numerous potential therapeutic and diagnostic applications. Yet, much work remains in the elucidation of TMS mechanisms, optimization of protocols, and in development of novel therapeutic applications. As with many technologies, the key to these issues lies in the proper experimentation and translation of TMS methods to animal models, among which rat models have proven popular. A significant increase in the number of rat TMS publications has necessitated analysis of their relevance to human work. We therefore review the essential principles necessary for the approximation of human TMS protocols in rats as well as specific methods that addressed these issues in published studies. Materials and Methods We performed an English language literature search combined with our own experience and data. We address issues that we see as important in the translation of human TMS methods to rat models and provide a summary of key accomplishments in these areas. Results An extensive literature review illustrated the growth of rodent TMS studies in recent years. Current advances in the translation of single, paired-pulse, and repetitive stimulation paradigms to rodent models are presented. The importance of TMS in the generation of data for preclinical trials is also highlighted. Conclusions Rat TMS has several limitations when considering parallels between animal and human stimulation. However, it has proven to be a useful tool in the field of translational brain stimulation and will likely continue to aid in the design and implementation of stimulation protocols for therapeutic and diagnostic applications. PMID:22780329

Improving the antidepressant efficacy of transcranial magnetic stimulation: Maximizing the number of stimulations and treatment location in treatment resistant depression

PubMed Central

McDonald, William M.; Durkalski, Valerie; Ball, Edward R.; Holtzheimer, Paul E.; Pavlicova, Martina; Lisanby, Sarah H.; Avery, David; Anderson, Berry S.; Nahas, Ziad; Zarkowski, Paul; Sackeim, Harold A.; George, Mark S.

2015-01-01

Objective To assess the efficacy of increasing the number of fast left repetitive transcranial magnetic stimulations (rTMS) (10 Hz @ 120% of motor threshold (MT) over the left dorsolateral prefrontal cortex (DLPFC)) needed to achieve remission in treatment resistant depression (TRD). And, to determine if patients who do not remit to fast left will remit using slow right rTMS (1 Hz @ 120% MT over the right DLPFC). Method Patients were part of a multicenter sham controlled trial investigating the efficacy of fast left rTMS 1. Patients who failed to meet minimal response criteria in the sham controlled study could enroll in this open fast left rTMS study for an additional 3- 6 weeks. Patients who failed to remit to fast left could switch to slow right rTMS for up to four additional weeks. The final outcome measure was remission, defined as a HAM-D score of ≤ 3 or two consecutive HAM-D scores less than 10. Results Forty-three of 141 (30.5%) patients who enrolled in the open phase study eventually met criteria for remission. Patients who remitted during fast left treatment received a mean of 26 active treatments (90,000 pulses). 26% of patients who failed fast left remitted during slow right treatment. Conclusion The total number of rTMS stimulations needed to achieve remission in TRD may be higher than is used in most studies. TRD patients who do not respond to fast left rTMS may remit to slow right rTMS or additional rTMS stimulations. PMID:21898711

Linear polarizer local characterizations by polarimetric imaging for applications to polarimetric sensors for torque measurement for hybrid cars

NASA Astrophysics Data System (ADS)

Georges, F.; Remouche, M.; Meyrueis, P.

2011-06-01

Usually manufacturer's specifications do not deal with the ability of linear sheet polarizers to have a constant transmittance function over their geometric area. These parameters are fundamental for developing low cost polarimetric sensors(for instance rotation, torque, displacement) specifically for hybrid car (thermic + electricity power). It is then necessary to specially characterize commercial polarizers sheets to find if they are adapted to this kind of applications. In this paper, we present measuring methods and bench developed for this purpose, and some preliminary characterization results. We state conclusions for effective applications to hybrid car gearbox control and monitoring.

Millimeter Wave Sensor For On-Line Inspection Of Thin Sheet Dielectrics

DOEpatents

Bakhtiari, Sasan; Gopalsami, Nachappa; Raptis, Apostolos C.

1999-03-23

A millimeter wave sensor is provided for non-destructive inspection of thin sheet dielectric materials. The millimeter wave sensor includes a Gunn diode oscillator (GDO) source generating a mill meter wave electromagnetic energy signal having a single frequency. A heater is coupled to the GDO source for stabilizing the single frequency. A small size antenna is coupled to the GDO source for transmitting the millimeter wave electromagnetic energy signal to a sample material and for receiving a reflected millimeter wave electromagnetic energy signal from the sample material. Ferrite circulator isolators coupled between the GDO source and the antenna separate the millimeter wave electromagnetic energy signal into transmitted and received electromagnetic energy signal components and a detector detects change in both amplitude and phase of the transmitted and received electromagnetic energy signal components. A millimeter wave sensor is provided for non-destructive inspection of thin sheet dielectric materials. The millimeter wave sensor includes a Gunn diode oscillator (GDO) source generating a mill meter wave electromagnetic energy signal having a single frequency. A heater is coupled to the GDO source for stabilizing the single frequency. A small size antenna is coupled to the GDO source for transmitting the millimeter wave electromagnetic energy signal to a sample material and for receiving a reflected millimeter wave electromagnetic energy signal from the sample material. Ferrite circulator isolators coupled between the GDO source and the antenna separate the millimeter wave electromagnetic energy signal into transmitted and received electromagnetic energy signal components and a detector detects change in both amplitude and phase of the transmitted and received electromagnetic energy signal components.

Improved naming after TMS treatments in a chronic, global aphasia patient — case report

PubMed Central

NAESER, MARGARET A.; MARTIN, PAULA I; NICHOLAS, MARJORIE; BAKER, ERROL H.; SEEKINS, HEIDI; HELM-ESTABROOKS, NANCY; CAYER-MEADE, CAROL; KOBAYASHI, MASAHITO; THEORET, HUGO; FREGNI, FELIPE; TORMOS, JOSE MARIA; KURLAND, JACQUIE; DORON, KARL W.; PASCUAL-LEONE, ALVARO

2005-01-01

We report improved ability to name pictures at 2 and 8 months after repetitive transcranial magnetic stimulation (rTMS) treatments to the pars triangularis portion of right Broca’s homologue in a 57 year-old woman with severe nonfluent/global aphasia (6.5 years post left basal ganglia bleed, subcortical lesion). TMS was applied at 1 Hz, 20 minutes a day, 10 days, over a two-week period. She received no speech therapy during the study. One year after her TMS treatments, she entered speech therapy with continued improvement. TMS may have modulated activity in the remaining left and right hemisphere neural network for naming. PMID:16006338

Sensored Field Oriented Control of a Robust Induction Motor Drive Using a Novel Boundary Layer Fuzzy Controller

PubMed Central

Saghafinia, Ali; Ping, Hew Wooi; Uddin, Mohammad Nasir

2013-01-01

Physical sensors have a key role in implementation of real-time vector control for an induction motor (IM) drive. This paper presents a novel boundary layer fuzzy controller (NBLFC) based on the boundary layer approach for speed control of an indirect field-oriented control (IFOC) of an induction motor (IM) drive using physical sensors. The boundary layer approach leads to a trade-off between control performances and chattering elimination. For the NBLFC, a fuzzy system is used to adjust the boundary layer thickness to improve the tracking performance and eliminate the chattering problem under small uncertainties. Also, to eliminate the chattering under the possibility of large uncertainties, the integral filter is proposed inside the variable boundary layer. In addition, the stability of the system is analyzed through the Lyapunov stability theorem. The proposed NBLFC based IM drive is implemented in real-time using digital signal processor (DSP) board TI TMS320F28335. The experimental and simulation results show the effectiveness of the proposed NBLFC based IM drive at different operating conditions.

Imaging system design and image interpolation based on CMOS image sensor

NASA Astrophysics Data System (ADS)

Li, Yu-feng; Liang, Fei; Guo, Rui

2009-11-01

An image acquisition system is introduced, which consists of a color CMOS image sensor (OV9620), SRAM (CY62148), CPLD (EPM7128AE) and DSP (TMS320VC5509A). The CPLD implements the logic and timing control to the system. SRAM stores the image data, and DSP controls the image acquisition system through the SCCB (Omni Vision Serial Camera Control Bus). The timing sequence of the CMOS image sensor OV9620 is analyzed. The imaging part and the high speed image data memory unit are designed. The hardware and software design of the image acquisition and processing system is given. CMOS digital cameras use color filter arrays to sample different spectral components, such as red, green, and blue. At the location of each pixel only one color sample is taken, and the other colors must be interpolated from neighboring samples. We use the edge-oriented adaptive interpolation algorithm for the edge pixels and bilinear interpolation algorithm for the non-edge pixels to improve the visual quality of the interpolated images. This method can get high processing speed, decrease the computational complexity, and effectively preserve the image edges.

Neuroergonomics Deep Dive Literature Review, Volume 1: Neuroergonomics and Cognitive State

DTIC Science & Technology

2010-11-01

Neurophysiology, 108, 1-16. This paper compares TMS to TDCS . TDCS has very mild side effects when compared to those produced by TMS . Larger...use make it a good alternative to TMS . DC polarization can change the efficiency of cognitive processes without side effects. TDCS can alter verbal...with TMS and tDCS to better understand the effects of the stimulation. New imaging technologies such as DSI and MEG are also being considered

Multiple sessions of low-frequency repetitive transcranial magnetic stimulation in focal hand dystonia: clinical and physiological effects

PubMed Central

Kimberley, Teresa Jacobson; Borich, Michael R.; Arora, Sanjeev; Siebner, Hartwig R.

2016-01-01

Purpose The ability of low-frequency repetitive transcranial magnetic stimulation (rTMS) to enhance intracortical inhibition has motivated its use as a potential therapeutic intervention in focal hand dystonia (FHD). In this preliminary investigation, we assessed the physiologic and behavioral effects of multiple sessions of rTMS in FHD. Methods 12 patients with FHD underwent five daily-sessions of 1Hz rTMS to contralateral dorsal premotor cortex (dPMC). Patients held a pencil and made movements that did not elicit dystonic symptoms during rTMS. We hypothesized that an active but non-dystonic motor state would increase beneficial effects of rTMS. Five additional patients received sham-rTMS protocol. The area under curve (AUC) of the motor evoked potentials and the cortical silent period (CSP) were measured to assess changes in corticospinal excitability and intracortical inhibition, respectively. Behavioral measures included pen force and velocity during handwriting and subjective report. Results Multiple-session rTMS strengthened intracortical inhibition causing a prolongation of CSP after 3 days of intervention and pen force was reduced at day 1 and 5, leaving other measures unchanged. 68% of patients self-reported as ‘responders’ at day 5, and 58% at follow-up. Age predicted responders. Conclusions A strong therapeutic potential of this rTMS paradigm in FHD was not supported but findings warrant further investigation. PMID:23340117

The Efficacy of High-Frequency Repetitive Transcranial Magnetic Stimulation for Improving Apathy in Chronic Stroke Patients.

PubMed

Sasaki, Nobuyuki; Hara, Takatoshi; Yamada, Naoki; Niimi, Masachika; Kakuda, Wataru; Abo, Masahiro

2017-01-01

Although repetitive transcranial magnetic stimulation (rTMS) for hemiparesis is beneficial, so far no study has examined the usefulness of rTMS for apathy. Thirteen patients with chronic stroke were assigned randomly to 2 groups: rTMS group (n = 7) and sham stimulation group (n = 6). The patients received 5 sessions of either high-frequency rTMS over the region spanning from the dorsal anterior cingulate cortex (dACC) to medial prefrontal cortex (mPFC) or sham stimulation for 5 days. The severity of apathy was evaluated using the Apathy Scale (AS) and the severity of depression was evaluated using the Quick Inventory of Depressive Symptomatology (QIDS) serially before and after the 5-day protocol. The AS and QIDS scores were significantly improved in the rTMS group, although they were not changed in the sham stimulation group. The degree of change in the AS score was significantly greater in the rTMS group than that in the sham stimulation group. The degree of change in the QIDS score was greater in the rTMS group than that in the sham stimulation group, although the difference was not statistically significant. The application of high frequency rTMS over the dACC and mPFC may be a useful intervention for apathy due to stroke. © 2017 S. Karger AG, Basel.

Task-dependent activity and connectivity predict episodic memory network-based responses to brain stimulation in healthy aging

PubMed Central

Vidal-Piñeiro, Dídac; Martin-Trias, Pablo; Arenaza-Urquijo, Eider M.; Sala-Llonch, Roser; Mena-Sánchez, Isaias; Bargalló, Núria; Falcón, Carles; Pascual-Leone, Álvaro; Bartrés-Faz, David

2015-01-01

Background Transcranial Magnetic Stimulation (TMS) can affect episodic memory, one of the main cognitive hallmarks of aging, but the mechanisms of action remain unclear. Objectives To evaluate the behavioral and functional impact of excitatory TMS in a group of healthy elders. Methods We applied a paradigm of repetitive TMS -intermittent theta-burst stimulation- over left inferior frontal gyrus in healthy elders (n=24) and evaluated its impact on the performance of an episodic memory task with two levels of processing and the associated brain activity as captured by a pre and post fMRI scans. Results In the post-TMS fMRI we found TMS-related activity increases in left prefrontal and cerebellum-occipital areas specifically during deep encoding but not during shallow encoding or at rest. Furthermore, we found a task-dependent change in connectivity during the encoding task between cerebellum-occipital areas and the TMS-targeted left inferior frontal region. This connectivity change correlated with the TMS effects over brain networks. Conclusions The results suggest that the aged brain responds to brain stimulation in a state-dependent manner as engaged by different tasks components and that TMS effect is related to inter-individual connectivity changes measures. These findings reveal fundamental insights into brain network dynamics in aging and the capacity to probe them with combined behavioral and stimulation approaches. PMID:24485466

Human dorsolateral prefrontal cortex is involved in visual search for conjunctions but not features: a theta TMS study.

PubMed

Kalla, Roger; Muggleton, Neil G; Cowey, Alan; Walsh, Vincent

2009-10-01

Functional neuroimaging studies have shown that the detection of a target defined by more than one feature (for example, a conjunction of colour and orientation) amongst distractors is associated with the activation of a network of brain areas. Dorsolateral prefrontal cortex (DLPFC), along with areas such as the frontal eye fields (FEF) and posterior parietal cortex (PPC), is a component of this network. While transcranial magnetic stimulation (TMS) had shown that both FEF and PPC are necessary for, and not just correlated with, successful conjunction search, this is not the case for DLPFC. To test the hypothesis that this area is also necessary for efficient conjunction search, TMS was applied over DLPFC and the effects on conjunction and feature (in this case colour) search performance compared with those when TMS was delivered over area MT/V5 and a vertex control stimulation condition. DLPFC TMS impaired performance on the conjunction search task but was without effect on feature search, similar to findings when TMS is delivered over PPC or FEF. Vertex TMS had no effects whereas MT/V5 TMS significantly improved performance with a time course that may indicate that this was due to modulation of V4 activity. These findings illustrate that, like FEF and PPC, DLPFC is necessary for fully effective conjunction visual search performance.

Lasting effects of repeated rTMS application in focal hand dystonia.

PubMed

Borich, Michael; Arora, Sanjeev; Kimberley, Teresa Jacobson

2009-01-01

Focal hand dystonia (FHD) is a rare but potentially devastating disorder involving involuntary muscle spasms and abnormal posturing that impairs functional hand use. Increased cortical excitability and lack of inhibitory mechanisms have been associated with these symptoms. This study investigated the short- and long-term effects of repeated administrations of repetitive-transcranial magnetic stimulation (rTMS) on cortical excitability and handwriting performance. Six subjects with FHD and nine healthy controls were studied. All subjects with FHD received rTMS (1Hz) to the premotor cortex (PMC) for five consecutive days; of those, three subjects received five days of sham rTMS completed ten days prior to real treatment. Healthy subjects received one real rTMS session. Cortical silent period (CSP) and measures of handwriting performance were compared before and after treatment and at ten-day post-treatment follow-up. At baseline, significant differences in CSP and pen pressure were observed between subjects with FHD and healthy controls. Differences in CSP and pen velocity between subjects in real and sham rTMS groups were observed across treatment sessions and maintained at follow-up. After five days of rTMS to PMC, reduced cortical excitability and improved handwriting performance were observed and maintained at least ten days following treatment in subjects with FHD. These preliminary results support further investigation of the therapeutic potential of rTMS in FHD.

The Neuroprotective Mechanism of Low-Frequency rTMS on Nigral Dopaminergic Neurons of Parkinson's Disease Model Mice

PubMed Central

Dong, Qiaoyun; Wang, Yanyong; Gu, Ping; Shao, Rusheng; Zhao, Li; Liu, Xiqi; Wang, Zhanqiang; Wang, Mingwei

2015-01-01

Background. Parkinson's disease is a neurodegenerative disease in elder people, pathophysiologic basis of which is the severe deficiency of dopamine in the striatum. The purpose of the present study was to evaluate the neuroprotective effect of low-frequency rTMS on Parkinson's disease in model mice. Methods. The effects of low-frequency rTMS on the motor function, cortex excitability, neurochemistry, and neurohistopathology of MPTP-induced Parkinson's disease mice were investigated through behavioral detection, electrophysiologic technique, high performance liquid chromatography-electrochemical detection, immunohistochemical staining, and western blot. Results. Low-frequency rTMS could improve the motor coordination impairment of Parkinson's disease mice: the resting motor threshold significantly decreased in the Parkinson's disease mice; the degeneration of nigral dopaminergic neuron and the expression of tyrosine hydroxylase were significantly improved by low-frequency rTMS; moreover, the expressions of brain derived neurotrophic factor and glial cell line derived neurotrophic factor were also improved by low-frequency rTMS. Conclusions. Low-frequency rTMS had a neuroprotective effect on the nigral dopaminergic neuron which might be due to the improved expressions of brain derived neurotrophic factor and glial cell line-derived neurotrophic factor. The present study provided a theoretical basis for the application of low-frequency rTMS in the clinical treatment and recovery of Parkinson's disease. PMID:25883828

Task-dependent activity and connectivity predict episodic memory network-based responses to brain stimulation in healthy aging.

PubMed

Vidal-Piñeiro, Dídac; Martin-Trias, Pablo; Arenaza-Urquijo, Eider M; Sala-Llonch, Roser; Clemente, Imma C; Mena-Sánchez, Isaias; Bargalló, Núria; Falcón, Carles; Pascual-Leone, Álvaro; Bartrés-Faz, David

2014-01-01

Transcranial magnetic stimulation (TMS) can affect episodic memory, one of the main cognitive hallmarks of aging, but the mechanisms of action remain unclear. To evaluate the behavioral and functional impact of excitatory TMS in a group of healthy elders. We applied a paradigm of repetitive TMS - intermittent theta-burst stimulation - over left inferior frontal gyrus in healthy elders (n = 24) and evaluated its impact on the performance of an episodic memory task with two levels of processing and the associated brain activity as captured by a pre and post fMRI scans. In the post-TMS fMRI we found TMS-related activity increases in left prefrontal and cerebellum-occipital areas specifically during deep encoding but not during shallow encoding or at rest. Furthermore, we found a task-dependent change in connectivity during the encoding task between cerebellum-occipital areas and the TMS-targeted left inferior frontal region. This connectivity change correlated with the TMS effects over brain networks. The results suggest that the aged brain responds to brain stimulation in a state-dependent manner as engaged by different tasks components and that TMS effect is related to inter-individual connectivity changes measures. These findings reveal fundamental insights into brain network dynamics in aging and the capacity to probe them with combined behavioral and stimulation approaches. Copyright © 2014 Elsevier Inc. All rights reserved.

Add-on deep transcranial magnetic stimulation (dTMS) in patients with dysthymic disorder comorbid with alcohol use disorder: a comparison with standard treatment.

PubMed

Girardi, Paolo; Rapinesi, Chiara; Chiarotti, Flavia; Kotzalidis, Georgios D; Piacentino, Daria; Serata, Daniele; Del Casale, Antonio; Scatena, Paola; Mascioli, Flavia; Raccah, Ruggero N; Brugnoli, Roberto; Digiacomantonio, Vittorio; Ferri, Vittoria Rachele; Ferracuti, Stefano; Zangen, Abraham; Angeletti, Gloria

2015-01-01

Dorsolateral prefrontal cortex (DLPFC) is dysfunctional in mood and substance use disorders. We predicted higher efficacy for add-on bilateral prefrontal high-frequency deep transcranial magnetic stimulation (dTMS), compared with standard drug treatment (SDT) in patients with dysthymic disorder (DD)/alcohol use disorder (AUD) comorbidity. We carried-out a 6-month open-label study involving 20 abstinent patients with DSM-IV-TR AUD comorbid with previously developed DD. Ten patients received SDT for AUD with add-on bilateral dTMS (dTMS-AO) over the DLPFC, while another 10 received SDT alone. We rated alcohol craving with the Obsessive Compulsive Drinking Scale (OCDS), depression with the Hamilton Depression Rating Scale (HDRS), clinical status with the Clinical Global Impressions scale (CGI), and global functioning with the Global Assessment of Functioning (GAF). At the end of the 20-session dTMS period (or an equivalent period in the SDT group), craving scores and depressive symptoms in the dTMS-AO group dropped significantly more than in the SDT group (P < 0.001 and P < 0.02, respectively). High frequency bilateral DLPFC dTMS with left preference was well tolerated and found to be effective as add-on in AUD. The potential of dTMS for reducing craving in substance use disorder patients deserves to be further investigated.

High-Performance Lithium-Oxygen Battery Electrolyte Derived from Optimum Combination of Solvent and Lithium Salt.

PubMed

Ahn, Su Mi; Suk, Jungdon; Kim, Do Youb; Kang, Yongku; Kim, Hwan Kyu; Kim, Dong Wook

2017-10-01

To fabricate a sustainable lithium-oxygen (Li-O 2 ) battery, it is crucial to identify an optimum electrolyte. Herein, it is found that tetramethylene sulfone (TMS) and lithium nitrate (LiNO 3 ) form the optimum electrolyte, which greatly reduces the overpotential at charge, exhibits superior oxygen efficiency, and allows stable cycling for 100 cycles. Linear sweep voltammetry (LSV) and differential electrochemical mass spectrometry (DEMS) analyses reveal that neat TMS is stable to oxidative decomposition and exhibit good compatibility with a lithium metal. But, when TMS is combined with typical lithium salts, its performance is far from satisfactory. However, the TMS electrolyte containing LiNO 3 exhibits a very low overpotential, which minimizes the side reactions and shows high oxygen efficiency. LSV-DEMS study confirms that the TMS-LiNO 3 electrolyte efficiently produces NO 2 - , which initiates a redox shuttle reaction. Interestingly, this NO 2 - /NO 2 redox reaction derived from the LiNO 3 salt is not very effective in solvents other than TMS. Compared with other common Li-O 2 solvents, TMS seems optimum solvent for the efficient use of LiNO 3 salt. Good compatibility with lithium metal, high dielectric constant, and low donicity of TMS are considered to be highly favorable to an efficient NO 2 - /NO 2 redox reaction, which results in a high-performance Li-O 2 battery.

Contribution of TMS and rTMS in the Understanding of the Pathophysiology and in the Treatment of Dystonia.

PubMed

Lozeron, Pierre; Poujois, Aurélia; Richard, Alexandra; Masmoudi, Sana; Meppiel, Elodie; Woimant, France; Kubis, Nathalie

2016-01-01

Dystonias represent a heterogeneous group of movement disorders responsible for sustained muscle contraction, abnormal postures, and muscle twists. It can affect focal or segmental body parts or be generalized. Primary dystonia is the most common form of dystonia but it can also be secondary to metabolic or structural dysfunction, the consequence of a drug's side-effect or of genetic origin. The pathophysiology is still not elucidated. Based on lesion studies, dystonia has been regarded as a pure motor dysfunction of the basal ganglia loop. However, basal ganglia lesions do not consistently produce dystonia and lesions outside basal ganglia can lead to dystonia; mild sensory abnormalities have been reported in the dystonic limb and imaging studies have shown involvement of multiple other brain regions including the cerebellum and the cerebral motor, premotor and sensorimotor cortices. Transcranial magnetic stimulation (TMS) is a non-invasive technique of brain stimulation with a magnetic field applied over the cortex allowing investigation of cortical excitability. Hyperexcitability of contralateral motor cortex has been suggested to be the trigger of focal dystonia. High or low frequency repetitive TMS (rTMS) can induce excitatory or inhibitory lasting effects beyond the time of stimulation and protocols have been developed having either a positive or a negative effect on cortical excitability and associated with prevention of cell death, γ-aminobutyric acid (GABA) interneurons mediated inhibition and brain-derived neurotrophic factor modulation. rTMS studies as a therapeutic strategy of dystonia have been conducted to modulate the cerebral areas involved in the disease. Especially, when applied on the contralateral (pre)-motor cortex or supplementary motor area of brains of small cohorts of dystonic patients, rTMS has shown a beneficial transient clinical effect in association with restrained motor cortex excitability. TMS is currently a valuable tool to improve our understanding of the pathophysiology of dystonia but large controlled studies using sham stimulation are still necessary to delineate the place of rTMS in the therapeutic strategy of dystonia. In this review, we will focus successively on the use of TMS as a tool to better understand pathophysiology, and the use of rTMS as a therapeutic strategy.

Synthesis and photophysics of conjugated azomethine polyrotaxanes

NASA Astrophysics Data System (ADS)

Resmerita, A.-M.; Farcas, F.; Rotaru, A.; Farcas, A.

2016-12-01

The photophysical properties of two polyazomethine polyrotaxanes (4•αCD and 4•TMS-αCD) composed of pyrene and triazole encapsulated into native and permodified α-cyclodextrin (αCD and TMS-αCD) cavities have been investigated and compared with those of the non-rotaxane 4 counterparts. Rotaxane formation results in improvements of the solubility in organic solvents, as well as better film forming ability combined with a high transparency. The polyrotaxane 4•TMS-αCD was soluble in toluene/DMF1/1 v/v mixture and displayed useful levels of thermal stability. The fluorescence spectroscopy of 4•αCD and 4•TMS-αCD shows an obvious blue shift both in excitation and emission spectra with respect to those of non-rotaxane counterparts. 4•TMS-αCD displays a continuous absorption spectrum, whereas the reference 4 does not show any absorption maximum, neither for its emission maximum, presumably because of its very low solubility in DMF. The improved fluorescence efficiency (ΦPL) of both polyrotaxanes is attributed to the hydrophobic micro-environment within αCD and TMS-αCD cavities. The surfaces of non-rotaxane 4 counterparts showed globular formations with an agglomeration tendency, while the encapsulated 4•αCD and 4•TMS-αCD rotaxane compounds exhibited smoother surfaces, comprised by smaller grains uniformly distributed on the surface of the solid films. The presence of the αCD and TMS-αCD in 4·αCD and 4•TMS-αCD polyrotaxanes affects the LUMO energy levels to a greater extent than its HOMO energy with respect to reference 4. The wetting properties of spin-coated film of 4•TMS-αCD in water (polar) and diiodomethane (apolar), indicates that TMS-αCD makes its surface more hydrophobic. The dispersive and polar components are lower than that of the reference compounds. The doping of the rotaxane structures with iodine (I2) indicated smaller improvements of electrical conductivity (σ) values, which presents a tradeoff with their better solubility, process ability, surface characteristics and ΦPL.

Multifocal repetitive TMS for motor and mood symptoms of Parkinson disease

PubMed Central

Brys, Miroslaw; Fox, Michael D.; Agarwal, Shashank; Biagioni, Milton; Dacpano, Geraldine; Kumar, Pawan; Pirraglia, Elizabeth; Chen, Robert; Wu, Allan; Fernandez, Hubert; Shukla, Aparna Wagle; Lou, Jau-Shin; Gray, Zachary; Simon, David K.; Di Rocco, Alessandro

2016-01-01

Objective: To assess whether multifocal, high-frequency repetitive transcranial magnetic stimulation (rTMS) of motor and prefrontal cortex benefits motor and mood symptoms in patients with Parkinson disease (PD). Methods: Patients with PD and depression were enrolled in this multicenter, double-blind, sham-controlled, parallel-group study of real or realistic (electric) sham rTMS. Patients were randomized to 1 of 4 groups: bilateral M1 ( + sham dorsolateral prefrontal cortex [DLPFC]), DLPFC ( + sham M1), M1 + DLPFC, or double sham. The TMS course consisted of 10 daily sessions of 2,000 stimuli for the left DLPFC and 1,000 stimuli for each M1 (50 × 4-second trains of 40 stimuli at 10 Hz). Patients were evaluated at baseline, at 1 week, and at 1, 3, and 6 months after treatment. Primary endpoints were changes in motor function assessed with the Unified Parkinson's Disease Rating Scale-III and in mood with the Hamilton Depression Rating Scale at 1 month. Results: Of the 160 patients planned for recruitment, 85 were screened, 61 were randomized, and 50 completed all study visits. Real M1 rTMS resulted in greater improvement in motor function than sham at the primary endpoint (p < 0.05). There was no improvement in mood in the DLPFC group compared to the double-sham group, as well as no benefit to combining M1 and DLPFC stimulation for either motor or mood symptoms. Conclusions: In patients with PD with depression, M1 rTMS is an effective treatment of motor symptoms, while mood benefit after 2 weeks of DLPFC rTMS is not better than sham. Targeting both M1 and DLPFC in each rTMS session showed no evidence of synergistic effects. ClinicalTrials.gov identifier: NCT01080794. Classification of evidence: This study provides Class I evidence that in patients with PD with depression, M1 rTMS leads to improvement in motor function while DLPFC rTMS does not lead to improvement in depression compared to sham rTMS. PMID:27708129

Low-Intensity Repetitive Transcranial Magnetic Stimulation Improves Abnormal Visual Cortical Circuit Topography and Upregulates BDNF in Mice

PubMed Central

Makowiecki, Kalina; Harvey, Alan R.; Sherrard, Rachel M.

2014-01-01

Repetitive transcranial magnetic stimulation (rTMS) is increasingly used as a treatment for neurological and psychiatric disorders. Although the induced field is focused on a target region during rTMS, adjacent areas also receive stimulation at a lower intensity and the contribution of this perifocal stimulation to network-wide effects is poorly defined. Here, we examined low-intensity rTMS (LI-rTMS)-induced changes on a model neural network using the visual systems of normal (C57Bl/6J wild-type, n = 22) and ephrin-A2A5−/− (n = 22) mice, the latter possessing visuotopic anomalies. Mice were treated with LI-rTMS or sham (handling control) daily for 14 d, then fluorojade and fluororuby were injected into visual cortex. The distribution of dorsal LGN (dLGN) neurons and corticotectal terminal zones (TZs) was mapped and disorder defined by comparing their actual location with that predicted by injection sites. In the afferent geniculocortical projection, LI-rTMS decreased the abnormally high dispersion of retrogradely labeled neurons in the dLGN of ephrin-A2A5−/− mice, indicating geniculocortical map refinement. In the corticotectal efferents, LI-rTMS improved topography of the most abnormal TZs in ephrin-A2A5−/− mice without altering topographically normal TZs. To investigate a possible molecular mechanism for LI-rTMS-induced structural plasticity, we measured brain derived neurotrophic factor (BDNF) in the visual cortex and superior colliculus after single and multiple stimulations. BDNF was upregulated after a single stimulation for all groups, but only sustained in the superior colliculus of ephrin-A2A5−/− mice. Our results show that LI-rTMS upregulates BDNF, promoting a plastic environment conducive to beneficial reorganization of abnormal cortical circuits, information that has important implications for clinical rTMS. PMID:25100609

TMSEEG: A MATLAB-Based Graphical User Interface for Processing Electrophysiological Signals during Transcranial Magnetic Stimulation.

PubMed

Atluri, Sravya; Frehlich, Matthew; Mei, Ye; Garcia Dominguez, Luis; Rogasch, Nigel C; Wong, Willy; Daskalakis, Zafiris J; Farzan, Faranak

2016-01-01

Concurrent recording of electroencephalography (EEG) during transcranial magnetic stimulation (TMS) is an emerging and powerful tool for studying brain health and function. Despite a growing interest in adaptation of TMS-EEG across neuroscience disciplines, its widespread utility is limited by signal processing challenges. These challenges arise due to the nature of TMS and the sensitivity of EEG to artifacts that often mask TMS-evoked potentials (TEP)s. With an increase in the complexity of data processing methods and a growing interest in multi-site data integration, analysis of TMS-EEG data requires the development of a standardized method to recover TEPs from various sources of artifacts. This article introduces TMSEEG, an open-source MATLAB application comprised of multiple algorithms organized to facilitate a step-by-step procedure for TMS-EEG signal processing. Using a modular design and interactive graphical user interface (GUI), this toolbox aims to streamline TMS-EEG signal processing for both novice and experienced users. Specifically, TMSEEG provides: (i) targeted removal of TMS-induced and general EEG artifacts; (ii) a step-by-step modular workflow with flexibility to modify existing algorithms and add customized algorithms; (iii) a comprehensive display and quantification of artifacts; (iv) quality control check points with visual feedback of TEPs throughout the data processing workflow; and (v) capability to label and store a database of artifacts. In addition to these features, the software architecture of TMSEEG ensures minimal user effort in initial setup and configuration of parameters for each processing step. This is partly accomplished through a close integration with EEGLAB, a widely used open-source toolbox for EEG signal processing. In this article, we introduce TMSEEG, validate its features and demonstrate its application in extracting TEPs across several single- and multi-pulse TMS protocols. As the first open-source GUI-based pipeline for TMS-EEG signal processing, this toolbox intends to promote the widespread utility and standardization of an emerging technology in brain research.

Consecutive TMS-fMRI reveals remote effects of neural noise to the "occipital face area".

PubMed

Solomon-Harris, Lily M; Rafique, Sara A; Steeves, Jennifer K E

2016-11-01

The human cortical system for face perception comprises a network of connected regions including the middle fusiform gyrus ("fusiform face area" or FFA), the inferior occipital gyrus ("occipital face area" or OFA), and the posterior superior temporal sulcus (pSTS). Here, we sought to investigate how transcranial magnetic stimulation (TMS) to the OFA affects activity within the face processing network. We used offline repetitive TMS to temporarily introduce neural noise in the right OFA in healthy subjects. We then immediately performed functional magnetic resonance imaging (fMRI) to measure changes in blood oxygenation level dependent (BOLD) signal across the face network using an fMR-adaptation (fMR-A) paradigm. We hypothesized that TMS to the right OFA would induce abnormal face identity coding throughout the face processing network in regions to which it has direct or indirect connections. Indeed, BOLD signal for face identity, but not non-face (butterfly) identity, decreased in the right OFA and FFA following TMS to the right OFA compared to both sham TMS and TMS to a control site, the nearby object-related lateral occipital area (LO). Further, TMS to the right OFA decreased face-related activation in the left FFA, without any effect in the left OFA. Our findings indicate that TMS to the right OFA selectively disrupts face coding at both the stimulation site and bilateral FFA. TMS to the right OFA also decreased BOLD signal for different identity stimuli in the right pSTS. Together with mounting evidence from patient studies, we demonstrate connectivity of the OFA within the face network and that its activity modulates face processing in bilateral FFA as well as the right pSTS. Moreover, this study shows that deep regions within the face network can be remotely probed by stimulating structures closer to the cortical surface. Copyright © 2016 Elsevier B.V. All rights reserved.

TMSEEG: A MATLAB-Based Graphical User Interface for Processing Electrophysiological Signals during Transcranial Magnetic Stimulation

PubMed Central

Atluri, Sravya; Frehlich, Matthew; Mei, Ye; Garcia Dominguez, Luis; Rogasch, Nigel C.; Wong, Willy; Daskalakis, Zafiris J.; Farzan, Faranak

2016-01-01

Concurrent recording of electroencephalography (EEG) during transcranial magnetic stimulation (TMS) is an emerging and powerful tool for studying brain health and function. Despite a growing interest in adaptation of TMS-EEG across neuroscience disciplines, its widespread utility is limited by signal processing challenges. These challenges arise due to the nature of TMS and the sensitivity of EEG to artifacts that often mask TMS-evoked potentials (TEP)s. With an increase in the complexity of data processing methods and a growing interest in multi-site data integration, analysis of TMS-EEG data requires the development of a standardized method to recover TEPs from various sources of artifacts. This article introduces TMSEEG, an open-source MATLAB application comprised of multiple algorithms organized to facilitate a step-by-step procedure for TMS-EEG signal processing. Using a modular design and interactive graphical user interface (GUI), this toolbox aims to streamline TMS-EEG signal processing for both novice and experienced users. Specifically, TMSEEG provides: (i) targeted removal of TMS-induced and general EEG artifacts; (ii) a step-by-step modular workflow with flexibility to modify existing algorithms and add customized algorithms; (iii) a comprehensive display and quantification of artifacts; (iv) quality control check points with visual feedback of TEPs throughout the data processing workflow; and (v) capability to label and store a database of artifacts. In addition to these features, the software architecture of TMSEEG ensures minimal user effort in initial setup and configuration of parameters for each processing step. This is partly accomplished through a close integration with EEGLAB, a widely used open-source toolbox for EEG signal processing. In this article, we introduce TMSEEG, validate its features and demonstrate its application in extracting TEPs across several single- and multi-pulse TMS protocols. As the first open-source GUI-based pipeline for TMS-EEG signal processing, this toolbox intends to promote the widespread utility and standardization of an emerging technology in brain research. PMID:27774054

Repetitive TMS to augment cognitive processing therapy in combat veterans of recent conflicts with PTSD: A randomized clinical trial.

PubMed

Kozel, F Andrew; Motes, Michael A; Didehbani, Nyaz; DeLaRosa, Bambi; Bass, Christina; Schraufnagel, Caitlin D; Jones, Penelope; Morgan, Cassie Rae; Spence, Jeffrey S; Kraut, Michael A; Hart, John

2018-03-15

The objective was to test whether repetitive Transcranial Magnetic Stimulation (rTMS) just prior to Cognitive Processing Therapy (CPT) would significantly improve the clinical outcome compared to sham rTMS prior to CPT in veterans with PTSD. Veterans 18-60 years of age with current combat-related PTSD symptoms were randomized, using a 1:1 ratio in a parallel design, to active (rTMS+CPT) versus sham (sham+CPT) rTMS just prior to weekly CPT for 12-15 sessions. Blinded raters evaluated veterans at baseline, after the 5th and 9th treatments, and at 1, 3, and 6 months post-treatment. Clinician Administered PTSD Scale (CAPS) was the primary outcome measure with the PTSD Checklist (PCL) as a secondary outcome measure. The TMS coil (active or sham) was positioned over the right dorsolateral prefrontal cortex (110% MT, 1Hz continuously for 30min, 1800 pulses/treatment). Of the 515 individuals screened for the study, 103 participants were randomized to either active (n = 54) or sham rTMS (n = 49). Sixty-two participants (60%) completed treatment and 59 (57%) completed the 6-month assessment. The rTMS+CPT group showed greater symptom reductions from baseline on both CAPS and PCL across CPT sessions and follow-up assessments, t(df ≥ 325) ≤ -2.01, p ≤ 0.023, one-tailed and t(df ≥ 303) ≤ -2.14, p ≤ 0.017, one-tailed, respectively. Participants were predominantly male and limited to one era of conflicts as well as those who could safely undergo rTMS. The addition of rTMS to CPT compared to sham with CPT produced significantly greater PTSD symptom reduction early in treatment and was sustained up to six months post-treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

The analgesic effect of therapeutic rTMS is not mediated or predicted by comorbid psychiatric or sleep disorders

PubMed Central

Lindholm, Pauliina; Lamusuo, Salla; Taiminen, Tero; Virtanen, Arja; Pertovaara, Antti; Forssell, Heli; Hagelberg, Nora; Jääskeläinen, Satu

2016-01-01

Abstract Background: Mechanisms underlying alleviation of neuropathic pain by repetitive transcranial magnetic stimulation (rTMS) of primary motor cortex (M1) and right secondary somatosensory cortex (S2) are only partly known. Patients with chronic neuropathic pain often have comorbidities like depression and sleep problems. Through functional connectivity, rTMS of M1 and S2 may activate dorsolateral prefrontal cortex, the target for treating depression with rTMS. Thus, the analgesic effect of rTMS could be mediated indirectly via improvement of psychiatric comorbidities or sleep. We examined whether rTMS has an independent analgesic effect or whether its clinical benefits depend on effects on mood or sleep. We also evaluated if comorbid psychiatric or sleep disorders predict the treatment outcome. Methods: Sixteen patients with chronic drug-resistant neuropathic orofacial pain participated in this randomized controlled crossover rTMS study. Patients’ psychiatric history was evaluated by a specialist in psychiatry. Intensity and interference of pain, mood, and the quality of sleep and life were evaluated at baseline and after 2 active (primary somatosensory cortex [S1]/M1 and S2) and placebo rTMS treatments. A logistic regression analysis was done to investigate predictors of treatment outcome. Results: The analgesic effect of the right S2 stimulation was not associated with improvement of psychiatric conditions or sleep, whereas S1/M1 stimulation improved sleep without significant analgesic effect (P = 0.013–0.046 in sleep scores). Psychiatric and sleep disorders were more common in patients than in the general population (P = 0.000–0.001 in sleep scores), but these comorbidities did not predict the rTMS treatment outcome. Conclusion: We conclude that rTMS to the right S2 does not exert its beneficial analgesic effects in chronic neuropathic orofacial pain via indirect improvement of comorbid psychiatric or sleep disorders. PMID:27858874

TMS affects moral judgment, showing the role of DLPFC and TPJ in cognitive and emotional processing.

PubMed

Jeurissen, Danique; Sack, Alexander T; Roebroeck, Alard; Russ, Brian E; Pascual-Leone, Alvaro

2014-01-01

Decision-making involves a complex interplay of emotional responses and reasoning processes. In this study, we use TMS to explore the neurobiological substrates of moral decisions in humans. To examining the effects of TMS on the outcome of a moral-decision, we compare the decision outcome of moral-personal and moral-impersonal dilemmas to each other and examine the differential effects of applying TMS over the right DLPFC or right TPJ. In this comparison, we find that the TMS-induced disruption of the DLPFC during the decision process, affects the outcome of the moral-personal judgment, while TMS-induced disruption of TPJ affects only moral-impersonal conditions. In other words, we find a double-dissociation between DLPFC and TPJ in the outcome of a moral decision. Furthermore, we find that TMS-induced disruption of the DLPFC during non-moral, moral-impersonal, and moral-personal decisions lead to lower ratings of regret about the decision. Our results are in line with the dual-process theory and suggest a role for both the emotional response and cognitive reasoning process in moral judgment. Both the emotional and cognitive processes were shown to be involved in the decision outcome.

Network-wise cerebral blood flow redistribution after 20 Hz rTMS on left dorso-lateral prefrontal cortex.

PubMed

Shang, Yuan-Qi; Xie, Jun; Peng, Wei; Zhang, Jian; Chang, Da; Wang, Ze

2018-04-01

The repetitive application of transcranial magnetic stimulation (rTMS) on left dorsolateral prefrontal cortex (DLPFC) has been consistently shown to be beneficial for treating various neuropsychiatric or neuropsychological disorders, but its neural mechanisms still remain unclear. The purpose of this study was to measure the effects of high-frequency left DLPFC rTMS using cerebral blood flow (CBF) collected from 40 young healthy subjects before and after applying 20 Hz left DLPFC rTMS or SHAM stimulations. Relative CBF (rCBF) changes before and after 20 Hz rTMS or SHAM were assessed with paired-t test. The results show that 20 Hz DLPFC rTMS induced CBF redistribution in the default mode network, including increased rCBF in left medial temporal cortex (MTC)/hippocampus, but reduced rCBF in precuneus and cerebellum. Meanwhile, SHAM stimulation didn't produce any rCBF changes. After controlling SHAM effects, only the rCBF increase in MTC/hippocampus remained. Those data suggest that the beneficial effects of high-frequency rTMS may be through a within-network rCBF redistribution. Copyright © 2018 Elsevier B.V. All rights reserved.

Novel transcranial magnetic stimulation coil for mice

NASA Astrophysics Data System (ADS)

March, Stephen; Stark, Spencer; Crowther, Lawrence; Hadimani, Ravi; Jiles, David

2014-03-01

Transcranial magnetic stimulation (TMS) shows potential for non-invasive treatment of various neurological disorders. Significant work has been performed on the design of coils used for TMS on human subjects but few reports have been made on the design of coils for use on the brains of animals such as mice. This work is needed as TMS studies utilizing mice can allow rapid preclinical development of TMS for human disorders but the coil designs developed for use on humans are inadequate for optimal stimulation of the much smaller mouse brain. A novel TMS coil has been developed with the goal of inducing strong and focused electric fields for the stimulation of small animals such as mice. Calculations of induced electric fields were performed utilizing an MRI derived inhomogeneous model of an adult male mouse. Mechanical and thermal analysis of this new TMS helmet-coil design have also been performed at anticipated TMS operating conditions to ensure mechanical stability of the new coil and establish expected linear attraction and rotational force values. Calculated temperature increases for typical stimulation periods indicate the helmet-coil system is capable of operating within established medical standards. A prototype of the coil has been fabricated and characterization results are presented.

Improved Discrimination of Visual Stimuli Following Repetitive Transcranial Magnetic Stimulation

PubMed Central

Waterston, Michael L.; Pack, Christopher C.

2010-01-01

Background Repetitive transcranial magnetic stimulation (rTMS) at certain frequencies increases thresholds for motor-evoked potentials and phosphenes following stimulation of cortex. Consequently rTMS is often assumed to introduce a “virtual lesion” in stimulated brain regions, with correspondingly diminished behavioral performance. Methodology/Principal Findings Here we investigated the effects of rTMS to visual cortex on subjects' ability to perform visual psychophysical tasks. Contrary to expectations of a visual deficit, we find that rTMS often improves the discrimination of visual features. For coarse orientation tasks, discrimination of a static stimulus improved consistently following theta-burst stimulation of the occipital lobe. Using a reaction-time task, we found that these improvements occurred throughout the visual field and lasted beyond one hour post-rTMS. Low-frequency (1 Hz) stimulation yielded similar improvements. In contrast, we did not find consistent effects of rTMS on performance in a fine orientation discrimination task. Conclusions/Significance Overall our results suggest that rTMS generally improves or has no effect on visual acuity, with the nature of the effect depending on the type of stimulation and the task. We interpret our results in the context of an ideal-observer model of visual perception. PMID:20442776

Antioxidant activity and chemical composition of Juniperus excelsa ssp. polycarpos wood extracts.

PubMed

Hosseinihashemi, S K; Dadpour, A; Lashgari, A

2017-03-01

Extracts from the wood of Juniperus excelsa ssp. polycarpos were analysed for their antioxidant activity using the DPPH method and compared with ascorbic acid and butylated hydroxytoluene. The most active extracts were analysed for their chemical composition using gas chromatography-mass spectrometry. Acetone extract was found to be moderately active as an antioxidant agent at 58.38%, which was lower than the value of vitamin C (98.56%) at the concentration of 14.20 mg/mL. The major components identified in the acetone extract as trimethylsilyl (TMS) derivatives were pimaric acid TMS (24.56%), followed by α-d-glucopyranoside,1,3,4,6-tetrakis-O-(TMS)-β-d-fructofuranosyl 2,3,4,6-tetrakis-O-(TMS) (21.39%), triflouromethyl-bis-(TMS)methyl ketone (9.32%), and cedrol (0.72%). The dissolved water:methanol (1:1 v/v) partitioned from acetone extract afforded 12 fractions; among them, the F9 fraction was found to have good antioxidant activity (88.49%) at the concentration of 14.20 mg/mL. The major compounds identified in F9 fraction were α-d-glucopyranoside, 1,3,4,6-tetrakis-O-(TMS) (20.22%) and trifluoromethyl-bis-(TMS)methyl ketone (5.10%).

[Treatment of chronic tinnitus with neuronavigated repetitive Transcranial Magnetic Stimulation (rTMS)].

PubMed

Kleinjung, T; Steffens, T; Langguth, B; Eichhammer, P; Marienhagen, J; Hajak, G; Strutz, J

2006-06-01

Idiopathic tinnitus is a frequent and debilitating disorder of largely unknown pathophysiology. Focal brain activation in the auditory cortex has recently been demonstrated in chronic tinnitus. Low-frequency rTMS can reduce cortical hyperexcitability. In 12 patients with chronic tinnitus, fusion of [18F]deoxyglucose-PET and structural MRI (T1, MPRAGE) scans allowed the area of increased metabolic activity in the auditory cortex to be exactly identified; this area was selected as the target for rTMS. A neuronavigational system adapted for TMS positioning enabled the relative positions of the figure-8 coil and the target area to be monitored. Repetitive TMS (110% motor threshold; 1 Hz; 2000 stimuli per day over 5 days) was performed using a placebo-controlled crossover design. A sham coil system was used for the placebo stimulation. Treatment outcome was assessed with a specific tinnitus questionnaire (Goebel and Hiller). In all 12 patients an asymmetrically increased metabolic activation of the gyrus of Heschl was detected. The tinnitus score was significantly improved after 5 days of active rTMS, an effect not seen after placebo stimulation. These preliminary results show that neuronavigated rTMS may improve our understanding and treatment of chronic tinnitus.

Long-lasting repetitive transcranial magnetic stimulation modulates electroencephalography oscillation in patients with disorders of consciousness.

PubMed

Xia, Xiaoyu; Liu, Yang; Bai, Yang; Liu, Ziyuan; Yang, Yi; Guo, Yongkun; Xu, Ruxiang; Gao, Xiaorong; Li, Xiaoli; He, Jianghong

2017-10-18

Repetitive transcranial magnetic stimulation (rTMS) has been applied for the treatment of patients with disorders of consciousness (DOC). Timely and accurate assessments of its modulation effects are very useful. This study evaluated rTMS modulation effects on electroencephalography (EEG) oscillation in patients with chronic DOC. Eighteen patients with a diagnosis of DOC lasting more than 3 months were recruited. All patients received one session of 10-Hz rTMS at the left dorsolateral prefrontal cortex and then 12 of them received consecutive rTMS treatment everyday for 20 consecutive days. Resting-state EEGs were recorded before the experiment (T0) after one session of rTMS (T1) and after the entire treatment (T2). The JFK Coma Recovery Scale-Revised scale scores were also recorded at the time points. Our data showed that application of 10-Hz rTMS to the left dorsolateral prefrontal cortex decreased low-frequency band power and increased high-frequency band power in DOC patients, especially in minimal conscious state patients. Considering the correlation of the EEG spectrum with the consciousness level of patients with DOC, quantitative EEG might be useful for assessment of the effect of rTMS in DOC patients.

TMS communications software. Volume 2: Bus interface unit

NASA Technical Reports Server (NTRS)

Gregor, P. J.

1979-01-01

A data bus communication system to support the space shuttle's Trend Monitoring System (TMS) and to provide a basis for evaluation of the bus concept is described. Installation of the system included developing both hardware and software interfaces between the bus and the specific TMS computers and terminals. The software written for the microprocessor-based bus interface units is described. The software implements both the general bus communications protocol and also the specific interface protocols for the TMS computers and terminals.

Transient alcohol craving suppression by rTMS of dorsal anterior cingulate: an fMRI and LORETA EEG study.

PubMed

De Ridder, Dirk; Vanneste, Sven; Kovacs, Silvia; Sunaert, Stefan; Dom, Geert

2011-05-27

It has recently become clear that alcohol addiction might be related to a brain dysfunction, in which a genetic background and environmental factors shape brain mechanisms involved with alcohol consumption. Craving, a major component determining relapses in alcohol abuse has been linked to abnormal activity in the orbitofrontal cortex, dorsal anterior cingulated cortex (dACC) and amygdala. We report the results of a patient who underwent rTMS targeting the dACC using a double cone coil in an attempt to suppress very severe intractable alcohol craving. Functional imaging studies consisting of fMRI and resting state EEG were performed before rTMS, after successful rTMS and after unsuccessful rTMS with relapse. Craving was associated with EEG beta activity and connectivity between the dACC and PCC in the patient in comparison to a healthy population, which disappeared after successful rTMS. Cue induced worsening of craving pre-rTMS activated the ACC-vmPFC and PCC on fMRI, as well as the nucleus accumbens area, and lateral frontoparietal areas. The nucleus accumbens, ACC-vmPFC and PCC activation disappeared on fMRI following successful rTMS. Relapse was associated with recurrence of ACC and PCC EEG activity, but in gamma band, in comparison to a healthy population. On fMRI nucleus accumbens, ACC and PCC activation returned to the initial activation pattern. A pathophysiological approach is described to suppress alcohol craving temporarily by rTMS directed at the anterior cingulate. Linking functional imaging changes to craving intensity suggests this approach warrants further exploration. Crown Copyright © 2011. Published by Elsevier Ireland Ltd. All rights reserved.

Consensus Recommendations for the Clinical Application of Repetitive Transcranial Magnetic Stimulation (rTMS) in the Treatment of Depression.

PubMed

McClintock, Shawn M; Reti, Irving M; Carpenter, Linda L; McDonald, William M; Dubin, Marc; Taylor, Stephan F; Cook, Ian A; O'Reardon, John; Husain, Mustafa M; Wall, Christopher; Krystal, Andrew D; Sampson, Shirlene M; Morales, Oscar; Nelson, Brent G; Latoussakis, Vassilios; George, Mark S; Lisanby, Sarah H

To provide expert recommendations for the safe and effective application of repetitive transcranial magnetic stimulation (rTMS) in the treatment of major depressive disorder (MDD). Participants included a group of 17 expert clinicians and researchers with expertise in the clinical application of rTMS, representing both the National Network of Depression Centers (NNDC) rTMS Task Group and the American Psychiatric Association Council on Research (APA CoR) Task Force on Novel Biomarkers and Treatments. The consensus statement is based on a review of extensive literature from 2 databases (OvidSP MEDLINE and PsycINFO) searched from 1990 through 2016. The search terms included variants of major depressive disorder and transcranial magnetic stimulation. The results were limited to articles written in English that focused on adult populations. Of the approximately 1,500 retrieved studies, a total of 118 publications were included in the consensus statement and were supplemented with expert opinion to achieve consensus recommendations on key issues surrounding the administration of rTMS for MDD in clinical practice settings. In cases in which the research evidence was equivocal or unclear, a consensus decision on how rTMS should be administered was reached by the authors of this article and is denoted in the article as "expert opinion." Multiple randomized controlled trials and published literature have supported the safety and efficacy of rTMS antidepressant therapy. These consensus recommendations, developed by the NNDC rTMS Task Group and APA CoR Task Force on Novel Biomarkers and Treatments, provide comprehensive information for the safe and effective clinical application of rTMS in the treatment of MDD. © Copyright 2017 Physicians Postgraduate Press, Inc.

The efficacy and safety of low frequency repetitive transcranial magnetic stimulation for treatment-resistant depression: the results from a large multicenter French RCT.

PubMed

Brunelin, Jerome; Jalenques, Isabelle; Trojak, Benoit; Attal, Jerome; Szekely, David; Gay, Aurélia; Januel, Dominique; Haffen, Emmanuel; Schott-Pethelaz, Anne-Marie; Brault, Coralie; Poulet, Emmanuel

2014-01-01

The aim of this study was to assess whether the combination of low frequency repetitive transcranial magnetic stimulation (rTMS) and venlafaxine (150-225 mg/day) is effective and safe for treatment-resistant unipolar depression (TRD). In a multicenter (18 centers) randomized double blind controlled trial with three arms, 170 patients were allocated to receive active rTMS combined with active venlafaxine (n = 55), active rTMS combined with placebo venlafaxine (n = 60) or sham rTMS combined with active venlafaxine (n = 55). The patients received once daily sessions of active or sham 1 Hz rTMS applied over the right dorsolateral prefrontal cortex (360 pulses/day delivered at 120% of the resting motor threshold) for two to six weeks; rTMS was combined with active or sham venlafaxine (mean dose: 179.0 ± 36.6 mg/day). The primary outcome was the number of patients who achieved remission, which was defined as an HDRS17 score <8. We reported a similar significant antidepressant effect in the 3 groups (P < 10(-6)), with a comparable delay of action and a comparable number of remitters at the endpoint (28% in the combination group, 41% in the rTMS group and 43% in the venlafaxine group; P = 0.59). Low frequency rTMS appears to be as effective as venlafaxine and as effective as the combination of both treatments for TRD. Because of its short session duration (the duration of one session was 8.5 min) and its safety, slow rTMS might be a useful alternative treatment for patients with TRD. Copyright © 2014 Elsevier Inc. All rights reserved.

Network Mechanisms of Clinical Response to Transcranial Magnetic Stimulation in Posttraumatic Stress Disorder and Major Depressive Disorder.

PubMed

Philip, Noah S; Barredo, Jennifer; van 't Wout-Frank, Mascha; Tyrka, Audrey R; Price, Lawrence H; Carpenter, Linda L

2018-02-01

Repetitive transcranial magnetic stimulation (TMS) therapy can modulate pathological neural network functional connectivity in major depressive disorder (MDD). Posttraumatic stress disorder is often comorbid with MDD, and symptoms of both disorders can be alleviated with TMS therapy. This is the first study to evaluate TMS-associated changes in connectivity in patients with comorbid posttraumatic stress disorder and MDD. Resting-state functional connectivity magnetic resonance imaging was acquired before and after TMS therapy in 33 adult outpatients in a prospective open trial. TMS at 5 Hz was delivered, in up to 40 daily sessions, to the left dorsolateral prefrontal cortex. Analyses used a priori seeds relevant to TMS, posttraumatic stress disorder, or MDD (subgenual anterior cingulate cortex [sgACC], left dorsolateral prefrontal cortex, hippocampus, and basolateral amygdala) to identify imaging predictors of response and to evaluate clinically relevant changes in connectivity after TMS, followed by leave-one-out cross-validation. Imaging results were explored using data-driven multivoxel pattern activation. More negative pretreatment connectivity between the sgACC and the default mode network predicted clinical improvement, as did more positive amygdala-to-ventromedial prefrontal cortex connectivity. After TMS, symptom reduction was associated with reduced connectivity between the sgACC and the default mode network, left dorsolateral prefrontal cortex, and insula, and reduced connectivity between the hippocampus and the salience network. Multivoxel pattern activation confirmed seed-based predictors and correlates of treatment outcomes. These results highlight the central role of the sgACC, default mode network, and salience network as predictors of TMS response and suggest their involvement in mechanisms of action. Furthermore, this work indicates that there may be network-based biomarkers of clinical response relevant to these commonly comorbid disorders. Published by Elsevier Inc.

The right posterior inferior frontal gyrus contributes to phonological word decisions in the healthy brain: evidence from dual-site TMS.

PubMed

Hartwigsen, Gesa; Price, Cathy J; Baumgaertner, Annette; Geiss, Gesine; Koehnke, Maria; Ulmer, Stephan; Siebner, Hartwig R

2010-08-01

There is consensus that the left hemisphere plays a dominant role in language processing, but functional imaging studies have shown that the right as well as the left posterior inferior frontal gyri (pIFG) are activated when healthy right-handed individuals make phonological word decisions. Here we used online transcranial magnetic stimulation (TMS) to examine the functional relevance of the right pIFG for auditory and visual phonological decisions. Healthy right-handed individuals made phonological or semantic word judgements on the same set of auditorily and visually presented words while they received stereotactically guided TMS over the left, right or bilateral pIFG (n=14) or the anterior left, right or bilateral IFG (n=14). TMS started 100ms after word onset and consisted of four stimuli given at a rate of 10Hz and intensity of 90% of active motor threshold. Compared to TMS of aIFG, TMS of pIFG impaired reaction times and accuracy of phonological but not semantic decisions for visually and auditorily presented words. TMS over left, right or bilateral pIFG disrupted phonological processing to a similar degree. In a follow-up experiment, the intensity threshold for delaying phonological judgements was identical for unilateral TMS of left and right pIFG. These findings indicate that an intact function of right pIFG is necessary for accurate and efficient phonological decisions in the healthy brain with no evidence that the left and right pIFG can compensate for one another during online TMS. Our findings motivate detailed studies of phonological processing in patients with acute and chronic damage of the right pIFG. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Transcranial magnetic stimulation of the dorsal lateral prefrontal cortex inhibits medial orbitofrontal activity in smokers.

PubMed

Li, Xingbao; Sahlem, Gregory L; Badran, Bashar W; McTeague, Lisa M; Hanlon, Colleen A; Hartwell, Karen J; Henderson, Scott; George, Mark S

2017-12-01

Several studies have shown that repetitive transcranial magnetic stimulation (rTMS), applied to the dorsolateral prefrontal cortex (DLPFC), can reduce cue-elicited craving in smokers. Currently, the mechanism of this effect is unknown. We used functional magnetic resonance imaging (fMRI) to explore the effect of a single treatment of rTMS on cortical and sub-cortical neural activity in non-treatment seeking nicotine-dependent participants. We conducted a randomized, counterbalanced, crossover trial in which participants attended two experimental visits separated by at least 1 week. On the first visit, participants received either active, or sham rTMS (10 Hz, 5 s-on, 10 s-off, 100% motor threshold, 3,000 pulses) over the left DLPFC, and on the second visit they received the opposite condition (active or sham). Cue craving fMRI scans were completed before and after each rTMS session. A total of 11 non-treatment seeking nicotine-dependent cigarette smokers were enrolled in the study [six female, average age 39.7 ± 13.2, average cigarettes per day 17.3 ± 5.9]. Active rTMS decreased activity in the contralateral medial orbitofrontal cortex (mOFC) and ipsilateral nucleus accumbens (NAc) compared to sham rTMS. This preliminary data suggests that one session of rTMS applied to the DLPFC decreases brain activity in the NAc and mOFC in smokers. rTMS may exert its anti-craving effect by decreasing activity in the NAc and mOFC in smokers. Despite a small sample size, these findings warrant future rTMS/fMRI studies in addictions. (Am J Addict 2017;26:788-794). © 2017 American Academy of Addiction Psychiatry.

Real-time measurement of cerebral blood flow during and after repetitive transcranial magnetic stimulation: A near-infrared spectroscopy study.

PubMed

Park, Eunhee; Kang, Min Jae; Lee, Ahee; Chang, Won Hyuk; Shin, Yong-Il; Kim, Yun-Hee

2017-07-13

To confirm the interhemispheric modulation induced by low-frequency repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex, real-time regional cerebral blood flow (rCBF) was assessed using functional near-infrared spectroscopy (fNIRS) in the contralateral primary motor cortex (M1) and premotor cortex (PM). Ten right-handed healthy subjects completed two experimental sessions that were randomly arranged for real or sham rTMS session. In the real rTMS session, fNIRS data were acquired from the right M1 and PM area, while the motor hot spot of the left M1 was stimulated with 1Hz rTMS for 1200 pulses with two boosters. In the sham stimulation session, stimulation was delivered with a disconnected coil. During the real rTMS session, the concentration of oxyhemoglobin ([oxy-Hb]) in the right M1 increased continuously until the end of the stimulation. These changes lasted for 20min, while the right PM did not show a change in [oxy-Hb] concentration. On the other hand, the concentration of deoxy-hemoglobin ([deoxy-Hb]) decreased continuously in the right M1 and PM during the real rTMS stimulation, and this change lasted for 20min after the stimulation. The sham stimulation did not exhibit any significant change in both [oxy-Hb] and [deoxy-Hb] concentration during or after the stimulation. Application of 1Hz rTMS over M1 resulted in changes of rCBF in contralateral M1 and PM, which seemed to constitute a function of interhemispheric modulation of rTMS. The fNIRS data was able to detect this physiological change of neuromodulatory action of rTMS in real-time. Copyright © 2017. Published by Elsevier B.V.

Vertex Stimulation as a Control Site for Transcranial Magnetic Stimulation: A Concurrent TMS/fMRI Study.

PubMed

Jung, JeYoung; Bungert, Andreas; Bowtell, Richard; Jackson, Stephen R

2016-01-01

A common control condition for transcranial magnetic stimulation (TMS) studies is to apply stimulation at the vertex. An assumption of vertex stimulation is that it has relatively little influence over on-going brain processes involved in most experimental tasks, however there has been little attempt to measure neural changes linked to vertex TMS. Here we directly test this assumption by using a concurrent TMS/fMRI paradigm in which we investigate fMRI blood-oxygenation-level-dependent (BOLD) signal changes across the whole brain linked to vertex stimulation. Thirty-two healthy participants to part in this study. Twenty-one were stimulated at the vertex, at 120% of resting motor threshold (RMT), with short bursts of 1 Hz TMS, while functional magnetic resonance imaging (fMRI) BOLD images were acquired. As a control condition, we delivered TMS pulses over the left primary motor cortex using identical parameters to 11 other participants. Vertex stimulation did not evoke increased BOLD activation at the stimulated site. By contrast we observed widespread BOLD deactivations across the brain, including regions within the default mode network (DMN). To examine the effects of vertex stimulation a functional connectivity analysis was conducted. The results demonstrated that stimulating the vertex with suprathreshold TMS reduced neural activity in brain regions related to the DMN but did not influence the functional connectivity of this network. Our findings provide brain imaging evidence in support of the use of vertex simulation as a control condition in TMS but confirm that vertex TMS induces regional widespread decreases in BOLD activation. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Reductions in Cortico-Striatal Hyperconnectivity Accompany Successful Treatment of Obsessive-Compulsive Disorder with Dorsomedial Prefrontal rTMS

PubMed Central

Dunlop, Katharine; Woodside, Blake; Olmsted, Marion; Colton, Patricia; Giacobbe, Peter; Downar, Jonathan

2016-01-01

Obsessive-compulsive disorder (OCD) is a disabling illness with high rates of nonresponse to conventional treatments. OCD pathophysiology is believed to involve abnormalities in cortico-striatal-thalamic-cortical circuits through regions such as dorsomedial prefrontal cortex (dmPFC) and ventral striatum. These regions may constitute therapeutic targets for neuromodulation treatments, such as repetitive transcranial magnetic stimulation (rTMS). However, the neurobiological predictors and correlates of successful rTMS treatment for OCD are unclear. Here, we used resting-state functional magnetic resonance imaging (fMRI) to identify neural predictors and correlates of response to 20–30 sessions of bilateral 10 Hz dmPFC-rTMS in 20 treatment-resistant OCD patients, with 40 healthy controls as baseline comparators. A region of interest in the dmPFC was used to generate whole-brain functional connectivity maps pre-treatment and post treatment. Ten of 20 patients met the response criteria (⩾50% improvement on Yale-Brown Obsessive-Compulsive Scale, YBOCS); response to dmPFC-rTMS was sharply bimodal. dmPFC-rTMS responders had higher dmPFC-ventral striatal connectivity at baseline. The degree of reduction in this connectivity, from pre- to post-treatment, correlated to the degree of YBOCS symptomatic improvement. Baseline clinical and psychometric data did not predict treatment response. In summary, reductions in fronto-striatal hyperconnectivity were associated with treatment response to dmPFC-rTMS in OCD. This finding is consistent with previous fMRI studies of deep brain stimulation in OCD, but opposite to previous reports on mechanisms of dmPFC-rTMS in major depression. fMRI could prove useful in predicting the response to dmPFC-rTMS in OCD. PMID:26440813

Reductions in Cortico-Striatal Hyperconnectivity Accompany Successful Treatment of Obsessive-Compulsive Disorder with Dorsomedial Prefrontal rTMS.

PubMed

Dunlop, Katharine; Woodside, Blake; Olmsted, Marion; Colton, Patricia; Giacobbe, Peter; Downar, Jonathan

2016-04-01

Obsessive-compulsive disorder (OCD) is a disabling illness with high rates of nonresponse to conventional treatments. OCD pathophysiology is believed to involve abnormalities in cortico-striatal-thalamic-cortical circuits through regions such as dorsomedial prefrontal cortex (dmPFC) and ventral striatum. These regions may constitute therapeutic targets for neuromodulation treatments, such as repetitive transcranial magnetic stimulation (rTMS). However, the neurobiological predictors and correlates of successful rTMS treatment for OCD are unclear. Here, we used resting-state functional magnetic resonance imaging (fMRI) to identify neural predictors and correlates of response to 20-30 sessions of bilateral 10 Hz dmPFC-rTMS in 20 treatment-resistant OCD patients, with 40 healthy controls as baseline comparators. A region of interest in the dmPFC was used to generate whole-brain functional connectivity maps pre-treatment and post treatment. Ten of 20 patients met the response criteria (⩾50% improvement on Yale-Brown Obsessive-Compulsive Scale, YBOCS); response to dmPFC-rTMS was sharply bimodal. dmPFC-rTMS responders had higher dmPFC-ventral striatal connectivity at baseline. The degree of reduction in this connectivity, from pre- to post-treatment, correlated to the degree of YBOCS symptomatic improvement. Baseline clinical and psychometric data did not predict treatment response. In summary, reductions in fronto-striatal hyperconnectivity were associated with treatment response to dmPFC-rTMS in OCD. This finding is consistent with previous fMRI studies of deep brain stimulation in OCD, but opposite to previous reports on mechanisms of dmPFC-rTMS in major depression. fMRI could prove useful in predicting the response to dmPFC-rTMS in OCD.

Design of transcranial magnetic stimulation coils with optimal trade-off between depth, focality, and energy.

PubMed

Gomez, Luis J; Goetz, Stefan M; Peterchev, Angel V

2018-08-01

Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique used for research and clinical applications. Existent TMS coils are limited in their precision of spatial targeting (focality), especially for deeper targets. This paper presents a methodology for designing TMS coils to achieve optimal trade-off between the depth and focality of the induced electric field (E-field), as well as the energy required by the coil. A multi-objective optimization technique is used for computationally designing TMS coils that achieve optimal trade-offs between E-field focality, depth, and energy (fdTMS coils). The fdTMS coil winding(s) maximize focality (minimize the volume of the brain region with E-field above a given threshold) while reaching a target at a specified depth and not exceeding predefined peak E-field strength and required coil energy. Spherical and MRI-derived head models are used to compute the fundamental depth-focality trade-off as well as focality-energy trade-offs for specific target depths. Across stimulation target depths of 1.0-3.4 cm from the brain surface, the suprathreshold volume can be theoretically decreased by 42%-55% compared to existing TMS coil designs. The suprathreshold volume of a figure-8 coil can be decreased by 36%, 44%, or 46%, for matched, doubled, or quadrupled energy. For matched focality and energy, the depth of a figure-8 coil can be increased by 22%. Computational design of TMS coils could enable more selective targeting of the induced E-field. The presented results appear to be the first significant advancement in the depth-focality trade-off of TMS coils since the introduction of the figure-8 coil three decades ago, and likely represent the fundamental physical limit.

Efficacy and Safety of Low-field Synchronized Transcranial Magnetic Stimulation (sTMS) for Treatment of Major Depression.

PubMed

Leuchter, Andrew F; Cook, Ian A; Feifel, David; Goethe, John W; Husain, Mustafa; Carpenter, Linda L; Thase, Michael E; Krystal, Andrew D; Philip, Noah S; Bhati, Mahendra T; Burke, William J; Howland, Robert H; Sheline, Yvette I; Aaronson, Scott T; Iosifescu, Dan V; O'Reardon, John P; Gilmer, William S; Jain, Rakesh; Burgoyne, Karl S; Phillips, Bill; Manberg, Paul J; Massaro, Joseph; Hunter, Aimee M; Lisanby, Sarah H; George, Mark S

2015-01-01

Transcranial Magnetic Stimulation (TMS) customarily uses high-field electromagnets to achieve therapeutic efficacy in Major Depressive Disorder (MDD). Low-field magnetic stimulation also may be useful for treatment of MDD, with fewer treatment-emergent adverse events. To examine efficacy, safety, and tolerability of low-field magnetic stimulation synchronized to an individual's alpha frequency (IAF) (synchronized TMS, or sTMS) for treatment of MDD. Six-week double-blind sham-controlled treatment trial of a novel device that used three rotating neodymium magnets to deliver sTMS treatment. IAF was determined from a single-channel EEG prior to first treatment. Subjects had baseline 17-item Hamilton Depression Rating Scale (HamD17) ≥ 17. 202 subjects comprised the intent-to-treat (ITT) sample, and 120 subjects completed treatment per-protocol (PP). There was no difference in efficacy between active and sham in the ITT sample. Subjects in the PP sample (N = 59), however, had significantly greater mean decrease in HamD17 than sham (N = 60) (-9.00 vs. -6.56, P = 0.033). PP subjects with a history of poor response or intolerance to medication showed greater improvement with sTMS than did treatment-naïve subjects (-8.58 vs. -4.25, P = 0.017). Efficacy in the PP sample reflects exclusion of subjects who received fewer than 80% of scheduled treatments or were inadvertently treated at the incorrect IAF; these subgroups failed to separate from sham. There was no difference in adverse events between sTMS and sham, and no serious adverse events attributable to sTMS. Results suggest that sTMS may be effective, safe, and well tolerated for treating MDD when administered as intended. Copyright © 2015 Elsevier Inc. All rights reserved.

Catatonia with schizophrenia: From ECT to rTMS.

PubMed

Stip, E; Blain-Juste, M-E; Farmer, O; Fournier-Gosselin, M-P; Lespérance, P

2018-04-01

Electroconvulsive therapy is indicated in cases of catatonic schizophrenia following a failure of the challenge test with lorazepam or Zolpidem ® . Some patients need maintenance treatment with ECT. Repetitive Transcranial Magnetic Stimulation (rTMS) and anodal Transcranial direct-current stimulation (tDCS) might be effective against catatonia. Consider an alternative to ECT for a refractory patient. Twenty-one articles were identified mainly based on case reports series were found using search on Medline, Google Scholar, PsychInfo, CAIRNS. Key words were:"catatonia", and "rTMS", and more generally with"ECT","tDCS","Zolpidem ® ". At the end there were only six case reports with rTMS and three with tDCS. We discussed the alternative to ECT and follow up rTMS strategies illustrated by these case reports. Patients mean age was 35; numbers of previous ECT vary from zero to 556; the most common motor threshold (MT) is 80%, with two patients with 110%, the most common treatment placement is L DLPFC. In one of them, ECT was the only acute-state or maintenance treatment effective in this patient, who underwent 556 ECT sessions over 20 years. High-frequency rTMS was considered as a possible alternative, given the potential adverse effects of chronic maintenance ECT in a patient with comorbid epilepsy. rTMS treatment was 3-4×/week and over time extended to once every two weeks. A persistent objective improvement in catatonia was observed on the Bush-Francis Catatonia Rating Scale. rTMS is helpful for acute and maintenance treatment for catatonic schizophrenia who both failed multiple pharmacologic interventions and had safety concerns with continuing maintenance ECT. Clinicians should consider rTMS as a potential treatment option for refractory catatonia. Copyright © 2017 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Repetitive Transcranial Magnetic Stimulation for Clinical Applications in Neurological and Psychiatric Disorders: An Overview

PubMed Central

Machado, Sergio; Arias-Carrión, Oscar; Paes, Flávia; Vieira, Renata Teles; Caixeta, Leonardo; Novaes, Felipe; Marinho, Tamires; Almada, Leonardo Ferreira; Silva, Adriana Cardoso; Nardi, Antonio Egidio

2013-01-01

Neurological and psychiatric disorders are characterized by several disabling symptoms for which effective, mechanism-based treatments remain elusive. Consequently, more advanced non-invasive therapeutic methods are required. A method that may modulate brain activity and be viable for use in clinical practice is repetitive transcranial magnetic stimulation (rTMS). It is a non-invasive procedure whereby a pulsed magnetic field stimulates electrical activity in the brain. Here, we focus on the basic foundation of rTMS, the main stimulation parametters, the factors that influence individual responses to rTMS and the experimental advances of rTMS that may become a viable clinical application to treat neurological and psychiatric disorders. The findings showed that rTMS can improve some symptoms associated with these conditions and might be useful for promoting cortical plasticity in patients with neurological and psychiatric disorders. However, these changes are transient and it is premature to propose these applications as realistic therapeutic options, even though the rTMS technique has been evidenced as a potential modulator of sensorimotor integration and neuroplasticity. Functional imaging of the region of interest could highlight the capacity of rTMS to bring about plastic changes of the cortical circuitry and hint at future novel clinical interventions. Thus, we recommend that further studies clearly determine the role of rTMS in the treatment of these conditions. Finally, we must remember that however exciting the neurobiological mechanisms might be, the clinical usefulness of rTMS will be determined by its ability to provide patients with neurological and psychiatric disorders with safe, long-lasting and substantial improvements in quality of life. PMID:25610279

Magnetic Resonance Imaging-Guided, Open-Label, High-Frequency Repetitive Transcranial Magnetic Stimulation for Adolescents with Major Depressive Disorder.

PubMed

Wall, Christopher A; Croarkin, Paul E; Maroney-Smith, Mandie J; Haugen, Laura M; Baruth, Joshua M; Frye, Mark A; Sampson, Shirlene M; Port, John D

2016-09-01

Preliminary studies suggest that repetitive transcranial magnetic stimulation (rTMS) may be an effective and tolerable intervention for adolescents with treatment-resistant depression. There is limited rationale to inform coil placement for rTMS dosing in this population. We sought to examine and compare three localization techniques for coil placement in the context of an open-label trial of high-frequency rTMS for adolescents with treatment-resistant depression. Ten adolescents with treatment-resistant depression were enrolled in an open-label trial of high-frequency rTMS. Participants were offered 30 rTMS sessions (10 Hz, 120% motor threshold, left 3000 pulses applied to the dorsolateral prefrontal cortex) over 6-8 weeks. Coil placement for treatment was MRI guided. The scalp location for treatment was compared with the locations identified with standard 5 cm rule and Beam F3 methods. Seven adolescents completed 30 rTMS sessions. No safety or tolerability concerns were identified. Depression severity as assessed with the Children's Depression Rating Scale Revised improved from baseline to treatment 10, treatment 20, and treatment 30. Gains in depressive symptom improvement were maintained at 6 month follow-up visits. An MRI-guided approach for coil localization was feasible and efficient. Our results suggest that the 5 cm rule, Beam F3, and the MRI-guided localization approaches provided variable scalp targets for rTMS treatment. Open-label, high-frequency rTMS was feasible, tolerable, and effective for adolescents with treatment-resistant depression. Larger, blinded, sham-controlled trials are needed for definitive safety and efficacy data. Further efforts to understand optimal delivery, dosing, and biomarker development for rTMS treatments of adolescent depression are warranted.

Effect of Low-Frequency rTMS and NMES on Subacute Unilateral Hemispheric Stroke With Dysphagia

PubMed Central

Lim, Kil-Byung; Lee, Hong-Jae; Yoo, Jeehyun

2014-01-01

Objective To investigate the effect of low-frequency repetitive transcranial magnetic stimulation (rTMS) and neuromuscular electrical stimulation (NMES) on post-stroke dysphagia. Methods Subacute (<3 months), unilateral hemispheric stroke patients with dysphagia were randomly assigned to the conventional dysphagia therapy (CDT), rTMS, or NMES groups. In rTMS group, rTMS was performed at 100% resting motor threshold with 1 Hz frequency for 20 minutes per session (5 days per week for 2 weeks). In NMES group, electrical stimulation was applied to the anterior neck for 30 minutes per session (5 days per week for 2 weeks). All three groups were given conventional dysphagia therapy for 4 weeks. We evaluated the functional dysphagia scale (FDS), pharyngeal transit time (PTT), the penetration-aspiration scale (PAS), and the American Speech-Language Hearing Association National Outcomes Measurement System (ASHA NOMS) swallowing scale at baseline, after 2 weeks, and after 4 weeks. Results Forty-seven patients completed the study; 15 in the CDT group, 14 in the rTMS group, and 18 in the NMES group. Mean changes in FDS and PAS for liquid during first 2 weeks in the rTMS and NMES groups were significantly higher than those in the CDT group, but no significant differences were found between the rTMS and NMES group. No significant difference in mean changes of FDS and PAS for semi-solid, PTT, and ASHA NOMS was observed among the three groups. Conclusion These results indicated that both low-frequency rTMS and NMES could induce early recovery from dysphagia; therefore, they both could be useful therapeutic options for dysphagic stroke patients. PMID:25379488

The compensatory dynamic of inter-hemispheric interactions in visuospatial attention revealed using rTMS and fMRI

PubMed Central

Plow, Ela B.; Cattaneo, Zaira; Carlson, Thomas A.; Alvarez, George A.; Pascual-Leone, Alvaro; Battelli, Lorella

2014-01-01

A balance of mutual tonic inhibition between bi-hemispheric posterior parietal cortices is believed to play an important role in bilateral visual attention. However, experimental support for this notion has been mainly drawn from clinical models of unilateral damage. We have previously shown that low-frequency repetitive TMS (rTMS) over the intraparietal sulcus (IPS) generates a contralateral attentional deficit in bilateral visual tracking. Here, we used functional magnetic resonance imaging (fMRI) to study whether rTMS temporarily disrupts the inter-hemispheric balance between bilateral IPS in visual attention. Following application of 1 Hz rTMS over the left IPS, subjects performed a bilateral visual tracking task while their brain activity was recorded using fMRI. Behaviorally, tracking accuracy was reduced immediately following rTMS. Areas ventro-lateral to left IPS, including inferior parietal lobule (IPL), lateral IPS (LIPS), and middle occipital gyrus (MoG), showed decreased activity following rTMS, while dorsomedial areas, such as Superior Parietal Lobule (SPL), Superior occipital gyrus (SoG), and lingual gyrus, as well as middle temporal areas (MT+), showed higher activity. The brain activity of the homologues of these regions in the un-stimulated, right hemisphere was reversed. Interestingly, the evolution of network-wide activation related to attentional behavior following rTMS showed that activation of most occipital synergists adaptively compensated for contralateral and ipsilateral decrement after rTMS, while activation of parietal synergists, and SoG remained competing. This pattern of ipsilateral and contralateral activations empirically supports the hypothesized loss of inter-hemispheric balance that underlies clinical manifestation of visual attentional extinction. PMID:24860462

Surgery of language-eloquent tumors in patients not eligible for awake surgery: the impact of a protocol based on navigated transcranial magnetic stimulation on presurgical planning and language outcome, with evidence of tumor-induced intra-hemispheric plasticity.

PubMed

Raffa, Giovanni; Quattropani, Maria C; Scibilia, Antonino; Conti, Alfredo; Angileri, Filippo Flavio; Esposito, Felice; Sindorio, Carmela; Cardali, Salvatore Massimiliano; Germanò, Antonino; Tomasello, Francesco

2018-05-01

Awake surgery and intraoperative monitoring represent the gold standard for surgery of brain tumors located in the perisylvian region of the dominant hemisphere due to their ability to map and preserve the language network during surgery. Nevertheless, in some cases awake surgery is not feasible. This could increase the risk of postoperative language deficit. Navigated transcranial magnetic stimulation (nTMS) and nTMS-based DTI fiber tracking (DTI-FT) provide a preoperative mapping and reconstruction of the cortico-subcortical language network. This can be used to plan and guide the surgical strategy to preserve the language function. The objective if this study is to describe the impact of a non-invasive preoperative protocol for mapping the language network through the nTMS and nTMS-based DTI-FT in patients not eligible for awake surgery and thereby operated under general anesthesia for suspected language-eloquent brain tumors. We reviewed clinical data of patients not eligible for awake surgery and operated under general anaesthesia between 2015 and 2016. All patients underwent nTMS language cortical mapping and nTMS-based DTI-FT of subcortical language fascicles. The nTMS findings were used to plan and guide the maximal safe resection of the tumor. The impact on postoperative language outcome and the accuracy of the nTMS-based mapping in predicting language deficits were evaluated. Twenty patients were enrolled in the study. The nTMS-based reconstruction of the language network was successful in all patients. Interestingly, we observed a significant association between tumor localization and the cortical distribution of the nTMS errors (p = 0.004), thereby suggesting an intra-hemispheric plasticity of language cortical areas, probably induced by the tumor itself. The nTMS mapping disclosed the true-eloquence of lesions in 12 (60%) of all suspected cases. In the remaining 8 cases (40%) the suspected eloquence of the lesion was disproved. The nTMS-based findings guided the planning and surgery through the visual feedback of navigation. This resulted in a slight reduction of the postoperative language performance at discharge that was completely recovered after one month from surgery. The accuracy of the nTMS-based protocol in predicting postoperative permanent deficits was significantly high, especially for false-eloquent lesions (p = 0.04; sensitivity 100%, specificity 57.14%, negative predictive value 100%, positive predicitive value 50%). The nTMS-based preoperative mapping allows for a reliable visualization of the language network, being also able to identify an intra-hemispheric tumor-induced cortical plasticity. It allows for a customized surgical strategy that could preserve post-operative language function. This approach should be considered as a support for neurosurgeons whenever approaching patients affected by suspected language-eloquent tumors but not eligible for awake surgery. Copyright © 2018 Elsevier B.V. All rights reserved.

Station for spatially distributed measurements of soil moisture and ambient temperature

NASA Astrophysics Data System (ADS)

Jankovec, Jakub; Šanda, Martin; Haase, Tomáš; Sněhota, Michal; Wild, Jan

2013-04-01

Third generation of combined thermal and soil moisture standalone field station coded TMS3 with wireless communication is presented. The device combines three thermometers (MAXIM/DALLAS Semiconductor DS7505U with -55 to +125°C range and 0.0625°C resolution, 0.5°C precision in 0 to +70°C range and 2°C precision out of this range). Soil moisture measurement is performed based on time domain transmission (TDT) principle for the full range of soil moisture with 0.025% resolution within the full possible soil moisture span for the most typical conditions of dry to saturated soils with safe margins to enable measurements in freezing, hot or saline soils. Principal compact version is designed for temperature measurements approximately at heights -10, 0 and +15 cm relative to soil surface when installed vertically and soil moisture measurements between 0 and 12 cm below surface. Set of buriable/subsurface stations each with 2.2 meter extension cord with soil and surface temperature measurement provides possibility to scan vertical soil profile for soil moisture and temperature at desired depths. USB equipped station is designed for streamed direct data acquisition in laboratory use in 1s interval. Station is also equipped with the shock sensor indicating the manipulation. Presented version incorporates life time permanent data storage (0.5 million logs). Current sensor design aims towards improved durability in harsh outdoor environment with reliable functioning in wet conditions withstanding mechanical or electric shock destruction. Insertion into the soil is possible by pressing with the use of a simple plastic cover. Data are retrieved by contact portable pocket collector (second generation) or by RFID wireless communication for hundreds meter distance (third generation) in either star pattern of GSM hub to stations or lined up GSM to station to another station both in comprised data packets. This option will allow online data harvesting and real time process control (e.g. optimized irrigation) by the end of 2013. User selected regimes of scanning in the field standalone model is 1,5 or 15 minutes for soil moisture and 1, 5, 10 or 15 minutes for the temperature (in their practical combinations) with a battery and datastorage lifetime ranging 1 - 10 years. Basic station diagnostics is recorded daily, comprehensive check is performed monthly. The TMS2 undergoes calibration on sets of soils. Disturbed and packed cylindrical soil samples (approx. 20 liter) were subject to forced bottom air ventilation to distribute the moisture evenly along vertical axis during drying the sample with increased intensity. Database of soil-specific calibration curves is being built for various soil samples. TMS2 station has been calibrated for soil materials: sandy loam, quartz sand and peat. Calibration on selected undisturbed 7 liter samples, previously CT scanned for correct sensor placement, is in the progress. Temperature and salinity influence on the soil moisture results in drift of 0.05%/°C and 7%/(in full range of 0 to 10 miliSiemens/cm) and additional 2%/(in the range of 10 to 20 miliSiemens/cm) as found in 100% moisture solution. Extended testing of TMS1 generation, predecessor of current design, is successfully performed in variety of field locations (central Europe, central Africa, Himalaya region). Results of long-term measurement at hundreds of localities are successfully used for i) evaluation of species-specific environmental requirements (for different species of plants, bryophytes and fungi) and ii) extrapolation of microclimatic conditions over large areas of rugged sandstone relief with assistance of accurate, LiDAR based, digital terrain model. TMS1 units are e.g. also applied for continuous measurement of temperature and moisture of coarse woody debris, which serves as an important substrate for establishment and growth of seedlings and is thus crucial for natural regeneration of many forest ecosystems. The research is supported by the Technology Agency of the Czech Republic projects No. TA01021283 and SGS12/130/OHK1/2T/11.

Ultrafine Co Nanoparticles Encapsulated in Carbon-Nanotubes-Grafted Graphene Sheets as Advanced Electrocatalysts for the Hydrogen Evolution Reaction.

PubMed

Chen, Ziliang; Wu, Renbing; Liu, Yang; Ha, Yuan; Guo, Yanhui; Sun, Dalin; Liu, Miao; Fang, Fang

2018-06-10

The rational design of an efficient and inexpensive electrocatalyst based on earth-abundant 3d transition metals (TMs) for the hydrogen evolution reaction still remains a significant challenge in the renewable energy area. Herein, a novel and effective approach is developed for synthesizing ultrafine Co nanoparticles encapsulated in nitrogen-doped carbon nanotubes (N-CNTs) grafted onto both sides of reduced graphene oxide (rGO) (Co@N-CNTs@rGO) by direct annealing of GO-wrapped core-shell bimetallic zeolite imidazolate frameworks. Benefiting from the uniform distribution of Co nanoparticles, the in-situ-formed highly graphitic N-CNTs@rGO, the large surface area, and the abundant porosity, the as-fabricated Co@N-CNTs@rGO composites exhibit excellent electrocatalytic hydrogen evolution reaction (HER) activity. As demonstrated in electrochemical measurements, the composites can achieve 10 mA cm -2 at low overpotential with only 108 and 87 mV in 1 m KOH and 0.5 m H 2 SO 4 , respectively, much better than most of the reported Co-based electrocatalysts over a wide pH range. More importantly, the synthetic strategy is versatile and can be extended to prepare other binary or even ternary TMs@N-CNTs@rGO (e.g., Co-Fe@N-CNTs@rGO and Co-Ni-Cu@N-CNTs@rGO). The strategy developed here may open a new avenue toward the development of nonprecious high-performance HER catalysts. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Universal sensor interface module (USIM)

NASA Astrophysics Data System (ADS)

King, Don; Torres, A.; Wynn, John

1999-01-01

A universal sensor interface model (USIM) is being developed by the Raytheon-TI Systems Company for use with fields of unattended distributed sensors. In its production configuration, the USIM will be a multichip module consisting of a set of common modules. The common module USIM set consists of (1) a sensor adapter interface (SAI) module, (2) digital signal processor (DSP) and associated memory module, and (3) a RF transceiver model. The multispectral sensor interface is designed around a low-power A/D converted, whose input/output interface consists of: -8 buffered, sampled inputs from various devices including environmental, acoustic seismic and magnetic sensors. The eight sensor inputs are each high-impedance, low- capacitance, differential amplifiers. The inputs are ideally suited for interface with discrete or MEMS sensors, since the differential input will allow direct connection with high-impedance bridge sensors and capacitance voltage sources. Each amplifier is connected to a 22-bit (Delta) (Sigma) A/D converter to enable simultaneous samples. The low power (Delta) (Sigma) converter provides 22-bit resolution at sample frequencies up to 142 hertz (used for magnetic sensors) and 16-bit resolution at frequencies up to 1168 hertz (used for acoustic and seismic sensors). The video interface module is based around the TMS320C5410 DSP. It can provide sensor array addressing, video data input, data calibration and correction. The processor module is based upon a MPC555. It will be used for mode control, synchronization of complex sensors, sensor signal processing, array processing, target classification and tracking. Many functions of the A/D, DSP and transceiver can be powered down by using variable clock speeds under software command or chip power switches. They can be returned to intermediate or full operation by DSP command. Power management may be based on the USIM's internal timer, command from the USIM transceiver, or by sleep mode processing management. The low power detection mode is implemented by monitoring any of the sensor analog outputs at lower sample rates for detection over a software controllable threshold.

Repetitive Transcranial Magnetic Stimulation Activates Specific Regions in Rat Brain

NASA Astrophysics Data System (ADS)

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

1998-12-01

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS and electroconvulsive stimulation, a well-established animal model for electroconvulsive therapy. Our result shows that rTMS applied in conditions effective in animal models of depression induces different patterns of immediate-early gene expression than does electroconvulsive stimulation. In particular, rTMS evokes strong neural responses in the paraventricular nucleus of the thalamus (PVT) and in other regions involved in the regulation of circadian rhythms. The response in PVT is independent of the orientation of the stimulation probe relative to the head. Part of this response is likely because of direct activation, as repetitive magnetic stimulation also activates PVT neurons in brain slices.

Research with Transcranial Magnetic Stimulation in the Treatment of Aphasia

PubMed Central

Martin, Paula I; Naeser, Margaret A.; Ho, Michael; Treglia, Ethan; Kaplan, Elina; Baker, Errol H.; Pascual-Leone, Alvaro

2010-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been used to improve language behavior, including naming, in stroke patients with chronic, nonfluent aphasia. Part 1 of this paper reviews functional imaging studies related to language recovery in aphasia. Part 2 reviews the rationale for using rTMS to treat nonfluent aphasia (based on functional imaging); and presents our current rTMS protocol. We present language results from our rTMS studies, and imaging results from overt naming fMRI scans obtained pre- and post- a series of rTMS treatments. Part 3 presents results from a pilot study where rTMS treatments were followed immediately by constraint-induced language therapy. Part 4 reviews our diffusion tensor imaging study that examined possible connectivity of arcuate fasciculus to different parts of Broca’s area (pars triangularis, PTr; pars opercularis, POp); and to ventral premotor cortex (vPMC). The potential role of mirror neurons in R POp and vPMC in aphasia recovery is discussed. PMID:19818232

Transcranial magnetic stimulation in autism spectrum disorder: Challenges, promise, and roadmap for future research

PubMed Central

Oberman, Lindsay M.; Enticott, Peter G.; Casanova, Manuel F.; Rotenberg, Alexander; Pascual-Leone, Alvaro; McCracken, James T.

2016-01-01

Autism Spectrum Disorder (ASD) is a behaviorally defined complex neurodevelopmental syndrome characterized by impairments in social communication, by the presence of restricted and repetitive behaviors, interests and activities, and by abnormalities in sensory reactivity. Transcranial magnetic stimulation (TMS) is a promising, emerging tool for the study and potential treatment of ASD. Recent studies suggest that TMS measures provide rapid and noninvasive pathophysiological ASD biomarkers. Furthermore, repetitive TMS (rTMS) may represent a novel treatment strategy for reducing some of the core and associated ASD symptoms. However, the available literature on the TMS use in ASD is preliminary, composed of studies with methodological limitations. Thus, off-label clinical rTMS use for therapeutic interventions in ASD without an investigational device exemption and outside of an IRB approved research trial is premature pending further, adequately powered and controlled trials. Leaders in this field have gathered annually for a two-day conference (prior to the 2014 and 2015 International Meeting for Autism Research, IMFAR) to share recent progress, promote collaboration across laboratories, and establish consensus on protocols. Here we review the literature in the use of TMS in ASD in the context of the unique challenges required for the study and exploration of treatment strategies in this population. We also suggest future directions for this field of investigations. While its true potential in ASD has yet to be delineated, TMS represents an innovative research tool and a novel, possibly transformative approach to the treatment of neurodevelopmental disorders. PMID:26536383

Effects of 20 Hz Repetitive Transcranial Magnetic Stimulation on Disorders of Consciousness: A Resting-State Electroencephalography Study.

PubMed

He, Fangping; Wu, Min; Meng, Fanxia; Hu, Yangfan; Gao, Jian; Chen, Zhongqin; Bao, Wangxiao; Liu, Kehong; Luo, Benyan; Pan, Gang

2018-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been proposed as an experimental approach for the treatment of disorders of consciousness (DOC). To date, there has been little research into the use of rTMS in DOC and the therapeutic effects have been variously documented. This study aimed to examine the effects of 20 Hz rTMS on the electroencephalography (EEG) reactivity and clinical response in patients with DOC and to explore the neuromodulatory effects of high-frequency rTMS. In this randomized, sham-controlled, crossover study, real or sham 20 Hz rTMS was applied to the left primary motor cortex (M1) of patients with DOC for 5 consecutive days. Evaluations were blindly performed at the baseline (T0), immediately after the end of the 5 days of treatment (T1) and 1 week after the treatment (T2) using the JFK coma recovery scale-revised (CRS-R) and resting-state EEG. Only one patient, with a history of 2 months of traumatic brain injury, showed long-lasting (T1, T2) behavioral and neurophysiological modifications after the real rTMS stimulation. The 5 remaining patients presented brain reactivity localized at several electrodes, and the EEG modification was not significant. rTMS stimulation may improve awareness and arousal of DOC. Additionally, EEG represents a potential biomarker for the therapeutic efficacy of rTMS. This trial is registered with (NCT03385278).

A cortical substrate for the long-term memory of saccadic eye movements calibration.

PubMed

Pélisson, Denis; Habchi, Ouazna; Panouillères, Muriel T N; Hernoux, Charles; Farnè, Alessandro

2018-06-19

How movements are continuously adapted to physiological and environmental changes is a fundamental question in systems neuroscience. While many studies have elucidated the mechanisms which underlie short-term sensorimotor adaptation (∼10-30 min), how these motor memories are maintained over longer-term (>3-5 days) -and thanks to which neural systems-is virtually unknown. Here, we examine in healthy human participants whether the temporo-parietal junction (TPJ) is causally involved in the induction and/or the retention of saccadic eye movements' adaptation. Single-pulse transcranial magnetic stimulation (spTMS) was applied while subjects performed a ∼15min size-decrease adaptation task of leftward reactive saccades. A TMS pulse was delivered over the TPJ in the right hemisphere (rTPJ) in each trial either 30, 60, 90 or 120 msec (in 4 separate adaptation sessions) after the saccade onset. In two control groups of subjects, the same adaptation procedure was achieved either alone (No-TMS) or combined with spTMS applied over the vertex (SHAM-TMS). While the timing of spTMS over the rTPJ did not significantly affect the speed and immediate after-effect of adaptation, we found that the amount of adaptation retention measured 10 days later was markedly larger (42%) than in both the No-TMS (21%) and the SHAM-TMS (11%) control groups. These results demonstrate for the first time that the cerebral cortex is causally involved in maintaining long-term oculomotor memories. Copyright © 2018. Published by Elsevier Inc.

Changes in canine cerebral perfusion after accelerated high frequency repetitive transcranial magnetic stimulation (HF-rTMS): A proof of concept study.

PubMed

Dockx, R; Baeken, C; Duprat, R; De Vos, F; Saunders, J H; Polis, I; Audenaert, K; Peremans, K

2018-04-01

Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a treatment for several neuropsychiatric disorders in human beings, but the neurobiological effects of rTMS in dogs have not been investigated to date. A proof of concept study was designed to evaluate the effect of rTMS on cerebral perfusion, measured with single photon emission computed tomography (SPECT), in dogs. An accelerated high frequency (aHF)-rTMS (20Hz) protocol was applied to the canine left frontal cortex. To accurately target this area, eight dogs underwent a 3 Tesla magnetic resonance imaging (MRI) scan before stimulation. The left frontal cortex was subjected to five consecutive aHF-rTMS sessions with a figure-of-eight coil designed for human beings at an intensity of 110% of the motor threshold. The dogs underwent 99m Tc-d,1 hexamethylpropylene amine oxime (HMPAO) SPECT scans 1 week prior to and 1day after the stimulations. Perfusion indices (PIs) were determined semi-quantitatively; aHF-rTMS resulted in significantly increased PIs in the left frontal cortex and the subcortical region, whereas no significant differences were noted for the other regions. Behaviour was not influenced by the stimulation sessions. As has been observed in human beings, aHF-rTMS applied to the left frontal cortex alters regional cerebral perfusion in dogs. Copyright © 2018 Elsevier Ltd. All rights reserved.

TMS combined with EEG in genetic generalized epilepsy: A phase II diagnostic accuracy study.

PubMed

Kimiskidis, Vasilios K; Tsimpiris, Alkiviadis; Ryvlin, Philippe; Kalviainen, Reetta; Koutroumanidis, Michalis; Valentin, Antonio; Laskaris, Nikolaos; Kugiumtzis, Dimitris

2017-02-01

(A) To develop a TMS-EEG stimulation and data analysis protocol in genetic generalized epilepsy (GGE). (B) To investigate the diagnostic accuracy of TMS-EEG in GGE. Pilot experiments resulted in the development and optimization of a paired-pulse TMS-EEG protocol at rest, during hyperventilation (HV), and post-HV combined with multi-level data analysis. This protocol was applied in 11 controls (C) and 25 GGE patients (P), further dichotomized into responders to antiepileptic drugs (R, n=13) and non-responders (n-R, n=12).Features (n=57) extracted from TMS-EEG responses after multi-level analysis were given to a feature selection scheme and a Bayesian classifier, and the accuracy of assigning participants into the classes P-C and R-nR was computed. On the basis of the optimal feature subset, the cross-validated accuracy of TMS-EEG for the classification P-C was 0.86 at rest, 0.81 during HV and 0.92 at post-HV, whereas for R-nR the corresponding figures are 0.80, 0.78 and 0.65, respectively. Applying a fusion approach on all conditions resulted in an accuracy of 0.84 for the classification P-C and 0.76 for the classification R-nR. TMS-EEG can be used for diagnostic purposes and for assessing the response to antiepileptic drugs. TMS-EEG holds significant diagnostic potential in GGE. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

What Makes the Muscle Twitch: Motor System Connectivity and TMS-Induced Activity.

PubMed

Volz, Lukas J; Hamada, Masashi; Rothwell, John C; Grefkes, Christian

2015-09-01

Transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) evokes several volleys of corticospinal activity. While the earliest wave (D-wave) originates from axonal activation of cortico-spinal neurons (CSN), later waves (I-waves) result from activation of mono- and polysynaptic inputs to CSNs. Different coil orientations preferentially stimulate cortical elements evoking different outputs: latero-medial-induced current (LM) elicits D-waves and short-latency electromyographic responses (MEPs); posterior-anterior current (PA) evokes early I-waves. Anterior-posterior current (AP) is more variable and tends to recruit later I-waves, featuring longer onset latencies compared with PA-TMS. We tested whether the variability in response to AP-TMS was related to functional connectivity of the stimulated M1 in 20 right-handed healthy subjects who underwent functional magnetic resonance imaging while performing an isometric contraction task. The MEP-latency after AP-TMS (relative to LM-TMS) was strongly correlated with functional connectivity between the stimulated M1 and a network involving cortical premotor areas. This indicates that stronger premotor-M1 connectivity increases the probability that AP-TMS recruits shorter latency input to CSNs. In conclusion, our data strongly support the hypothesis that TMS of M1 activates distinct neuronal pathways depending on the orientation of the stimulation coil. Particularly, AP currents seem to recruit short latency cortico-cortical projections from premotor areas. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

(Z)3,4,5,4‧-trans-tetramethoxystilbene, a new analogue of resveratrol, inhibits gefitinb-resistant non-small cell lung cancer via selectively elevating intracellular calcium level

NASA Astrophysics Data System (ADS)

Fan, Xing-Xing; Yao, Xiao-Jun; Xu, Su Wei; Wong, Vincent Kam-Wai; He, Jian-Xing; Ding, Jian; Xue, Wei-Wei; Mujtaba, Tahira; Michelangeli, Francesco; Huang, Min; Huang, Jun; Xiao, Da-Kai; Jiang, Ze-Bo; Zhou, Yan-Ling; Kin-Ting Kam, Richard; Liu, Liang; Lai-Han Leung, Elaine

2015-11-01

Calcium is a second messenger which is required for regulation of many cellular processes. However, excessive elevation or prolonged activation of calcium signaling would lead to cell death. As such, selectively regulating calcium signaling could be an alternative approach for anti-cancer therapy. Recently, we have identified an effective analogue of resveratrol, (Z)3,4,5,4‧-trans-tetramethoxystilbene (TMS) which selectively elevated the intracellular calcium level in gefitinib-resistant (G-R) non-small-cell lung cancer (NSCLC) cells. TMS exhibited significant inhibitory effect on G-R NSCLC cells, but not other NSCLC cells and normal lung epithelial cells. The phosphorylation and activation of EGFR were inhibited by TMS in G-R cells. TMS induced caspase-independent apoptosis and autophagy by directly binding to SERCA and causing endoplasmic reticulum (ER) stress and AMPK activation. Proteomics analysis also further confirmed that mTOR pathway, which is the downstream of AMPK, was significantly suppressed by TMS. JNK, the cross-linker of ER stress and mTOR pathway was significantly activated by TMS. In addition, the inhibition of JNK activation can partially block the effect of TMS. Taken together, TMS showed promising anti-cancer activity by mediating calcium signaling pathway and inducing apoptosis as well as autophagy in G-R NSCLC cells, providing strategy in designing multi-targeting drug for treating G-R patients.

Stimulating Language: Insights from TMS

ERIC Educational Resources Information Center

Devlin, Joseph T.; Watkins, Kate E.

2007-01-01

Fifteen years ago, Pascual-Leone and colleagues used transcranial magnetic stimulation (TMS) to investigate speech production in pre-surgical epilepsy patients and in doing so, introduced a novel tool into language research. TMS can be used to non-invasively stimulate a specific cortical region and transiently disrupt information processing. These…

Different Stimulation Frequencies Alter Synchronous Fluctuations in Motor Evoked Potential Amplitude of Intrinsic Hand Muscles—a TMS Study

PubMed Central

Sale, Martin V.; Rogasch, Nigel C.; Nordstrom, Michael A.

2016-01-01

The amplitude of motor-evoked potentials (MEPs) elicited with transcranial magnetic stimulation (TMS) varies from trial-to-trial. Synchronous oscillations in cortical neuronal excitability contribute to this variability, however it is not known how different frequencies of stimulation influence MEP variability, and whether these oscillations are rhythmic or aperiodic. We stimulated the motor cortex with TMS at different regular (i.e., rhythmic) rates, and compared this with pseudo-random (aperiodic) timing. In 18 subjects, TMS was applied at three regular frequencies (0.05 Hz, 0.2 Hz, 1 Hz) and one aperiodic frequency (mean 0.2 Hz). MEPs (n = 50) were recorded from three intrinsic hand muscles of the left hand with different functional and anatomical relations. MEP amplitude correlation was highest for the functionally related muscle pair, less for the anatomically related muscle pair and least for the functionally- and anatomically-unrelated muscle pair. MEP correlations were greatest with 1 Hz, and least for stimulation at 0.05 Hz. Corticospinal neuron synchrony is higher with shorter TMS intervals. Further, corticospinal neuron synchrony is similar irrespective of whether the stimulation is periodic or aperiodic. These findings suggest TMS frequency is a crucial consideration for studies using TMS to probe correlated activity between muscle pairs. PMID:27014031

Teachable moments for health behavior change and intermediate patient outcomes.

PubMed

Flocke, Susan A; Clark, Elizabeth; Antognoli, Elizabeth; Mason, Mary Jane; Lawson, Peter J; Smith, Samantha; Cohen, Deborah J

2014-07-01

Teachable moments (TM) are opportunities created through physician-patient interaction and used to encourage patients to change unhealthy behaviors. We examine the effectiveness of TMs to increase patients' recall of advice, motivation to modify behavior, and behavior change. A mixed-method observational study of 811 patient visits to 28 primary care clinicians used audio-recordings of visits to identify TMs and other types of advice in health behavior change talk. Patient surveys assessed smoking, exercise, fruit/vegetable consumption, height, weight, and readiness for change prior to the observed visit and 6-weeks post-visit. Compared to other identified categories of advice (i.e. missed opportunities or teachable moment attempts), recall was greatest after TMs occurred (83% vs. 49-74%). TMs had the greatest proportion of patients change in importance and confidence and increase readiness to change; however differences were small. TMs had greater positive behavior change scores than other categories of advice; however, this pattern was statistically non-significant and was not observed for BMI change. TMs have a greater positive influence on several intermediate markers of patient behavior change compared to other categories of advice. TMs show promise as an approach for clinicians to discuss behavior change with patients efficiently and effectively. Copyright © 2014. Published by Elsevier Ireland Ltd.

Contribution of transcranial magnetic stimulation to assessment of brain connectivity and networks.

PubMed

Hallett, Mark; Di Iorio, Riccardo; Rossini, Paolo Maria; Park, Jung E; Chen, Robert; Celnik, Pablo; Strafella, Antonio P; Matsumoto, Hideyuki; Ugawa, Yoshikazu

2017-11-01

The goal of this review is to show how transcranial magnetic stimulation (TMS) techniques can make a contribution to the study of brain networks. Brain networks are fundamental in understanding how the brain operates. Effects on remote areas can be directly observed or identified after a period of stimulation, and each section of this review will discuss one method. EEG analyzed following TMS is called TMS-evoked potentials (TEPs). A conditioning TMS can influence the effect of a test TMS given over the motor cortex. A disynaptic connection can be tested also by assessing the effect of a pre-conditioning stimulus on the conditioning-test pair. Basal ganglia-cortical relationships can be assessed using electrodes placed in the process of deep brain stimulation therapy. Cerebellar-cortical relationships can be determined using TMS over the cerebellum. Remote effects of TMS on the brain can be found as well using neuroimaging, including both positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). The methods complement each other since they give different views of brain networks, and it is often valuable to use more than one technique to achieve converging evidence. The final product of this type of work is to show how information is processed and transmitted in the brain. Published by Elsevier B.V.

Effect of high-frequency repetitive transcranial magnetic stimulation on major depressive disorder in patients with Parkinson's disease.

PubMed

Shin, Hae-Won; Youn, Young C; Chung, Sun J; Sohn, Young H

2016-07-01

Major depressive disorder (MDD) occurs in a small proportion of patients with Parkinson's disease (PD) and reduces their quality of life. We performed a randomized sham-controlled study to evaluate the effect of high-frequency (HF) repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (DLPFC) on MDD in patients with PD. Ten patients participated to a real-rTMS group and eight patients to a sham-rTMS group. Evaluations were performed at baseline, 2 and 6 weeks after rTMS treatment. All participants underwent examinations of depression rating scales, including the Hamilton Rating Scale, the Montgomery-Asberg Depression Rating Scale (MADRS), and the Beck Depression Inventory (BDI) and the motor part of the Unified Parkinson Disease Rating Scale (UPDRS-III). The real-rTMS group had improved scores on HRS and the MADRS after 10 sessions, and these beneficial effects persisted for 6 weeks after the initial session. The BDI score did not change immediately after the sessions. The sham-rTMS group had no significant changes in any of the depression rating scales. The UPDRS-III did not change in either group. HF-rTMS of the left DLPFC is an effective treatment for MDD in patients with PD.

Numerical dosimetry of transcranial magnetic stimulation coils

NASA Astrophysics Data System (ADS)

Crowther, Lawrence; Hadimani, Ravi; Jiles, David

2014-03-01

Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique capable of stimulating neurons by means of electromagnetic induction. TMS can be used to map brain function and shows promise for the diagnosis and treatment of neurological and psychiatric disorders. Calculation of fields induced in the brain are necessary to accurately identify stimulated neural tissue during TMS. This allows the development of novel TMS coil designs capable of stimulating deeper brain regions and increasing the localization of stimulation that can be achieved. We have performed numerical calculations of magnetic and electric field with high-resolution anatomically realistic human head models to find these stimulated brain regions for a variety of proposed TMS coil designs. The realistic head models contain heterogeneous tissue structures and electrical conductivities, yielding superior results to those obtained from the simplified homogeneous head models that are commonly employed. The attenuation of electric field as a function of depth in the brain and the localization of stimulating field have been methodically investigated. In addition to providing a quantitative comparison of different TMS coil designs the variation of induced field between subjects has been investigated. We also show the differences in induced fields between adult, adolescent and child head models to preemptively identify potential safety issues in the application of pediatric TMS.

Comparison between neurostimulation techniques repetitive transcranial magnetic stimulation vs electroconvulsive therapy for the treatment of resistant depression: patient preference and cost-effectiveness.

PubMed

Magnezi, Racheli; Aminov, Emanuel; Shmuel, Dikla; Dreifuss, Merav; Dannon, Pinhas

2016-01-01

Major depressive disorder (MDD) is a common disorder, widely distributed in the population, and is often associated with severe symptoms and functional impairment. It has been estimated that 30% of MDD patients do not benefit adequately from therapeutic interventions, including pharmacotherapy and psychotherapy. Treatment-resistant depression (TRD) is generally defined as a failure to achieve remission, despite therapeutic interventions. The most effective treatment alternatives for TRD are hospitalization, electroconvulsive therapy (ECT), and transcranial magnetic stimulation (TMS). Here we compared the clinical effectiveness of ECT and TMS, including success rates, patient responses, side-effect profiles, and financial worthiness. We found that ECT (P<0.0001) was more effective than TMS (P<0.012) (not statistically significant in group effect) in TRD patients. However, ECT patients reported a higher percentage of side effects (P<0.01) and the TMS treatment scored better in terms of patient preference. The cost benefit of ECT was higher than that of TMS (US$2075 vs US$814). Patient's preferences for treatment could be more intense in the TMS, if the TMS is included in the Health Maintenance Organization's service list. We propose that both of these treatment options should be available in psychiatric wards, thus expanding the therapeutic toolkit for TRD.

Repetitive transcranial magnetic stimulation induces oscillatory power changes in chronic tinnitus

PubMed Central

Schecklmann, Martin; Lehner, Astrid; Gollmitzer, Judith; Schmidt, Eldrid; Schlee, Winfried; Langguth, Berthold

2015-01-01

Chronic tinnitus is associated with neuroplastic changes in auditory and non-auditory cortical areas. About 10 years ago, repetitive transcranial magnetic stimulation (rTMS) of auditory and prefrontal cortex was introduced as potential treatment for tinnitus. The resulting changes in tinnitus loudness are interpreted in the context of rTMS induced activity changes (neuroplasticity). Here, we investigate the effect of single rTMS sessions on oscillatory power to probe the capacity of rTMS to interfere with tinnitus-specific cortical plasticity. We measured 20 patients with bilateral chronic tinnitus and 20 healthy controls comparable for age, sex, handedness, and hearing level with a 63-channel electroencephalography (EEG) system. Educational level, intelligence, depressivity and hyperacusis were controlled for by analysis of covariance. Different rTMS protocols were tested: Left and right temporal and left and right prefrontal cortices were each stimulated with 200 pulses at 1 Hz and with an intensity of 60% stimulator output. Stimulation of central parietal cortex with 6-fold reduced intensity (inverted passive-cooled coil) served as sham condition. Before and after each rTMS protocol 5 min of resting state EEG were recorded. The order of rTMS protocols was randomized over two sessions with 1 week interval in between. Analyses on electrode level showed that people with and without tinnitus differed in their response to left temporal and right frontal stimulation. In tinnitus patients left temporal rTMS decreased frontal theta and delta and increased beta2 power, whereas right frontal rTMS decreased right temporal beta3 and gamma power. No changes or increases were observed in the control group. Only non-systematic changes in tinnitus loudness were induced by single sessions of rTMS. This is the first study to show tinnitus-related alterations of neuroplasticity that were specific to stimulation site and oscillatory frequency. The observed effects can be interpreted within the thalamocortical dysrhythmia model assuming that slow waves represent processes of deafferentiation and that high frequencies might be indicators for tinnitus loudness. Moreover our findings confirm the role of the left temporal and the right frontal areas as relevant hubs in tinnitus related neuronal network. Our results underscore the value of combined TMS-EEG measurements for investigating disease related changes in neuroplasticity. PMID:26557055

Contribution of TMS and rTMS in the Understanding of the Pathophysiology and in the Treatment of Dystonia

PubMed Central

Lozeron, Pierre; Poujois, Aurélia; Richard, Alexandra; Masmoudi, Sana; Meppiel, Elodie; Woimant, France; Kubis, Nathalie

2016-01-01

Dystonias represent a heterogeneous group of movement disorders responsible for sustained muscle contraction, abnormal postures, and muscle twists. It can affect focal or segmental body parts or be generalized. Primary dystonia is the most common form of dystonia but it can also be secondary to metabolic or structural dysfunction, the consequence of a drug’s side-effect or of genetic origin. The pathophysiology is still not elucidated. Based on lesion studies, dystonia has been regarded as a pure motor dysfunction of the basal ganglia loop. However, basal ganglia lesions do not consistently produce dystonia and lesions outside basal ganglia can lead to dystonia; mild sensory abnormalities have been reported in the dystonic limb and imaging studies have shown involvement of multiple other brain regions including the cerebellum and the cerebral motor, premotor and sensorimotor cortices. Transcranial magnetic stimulation (TMS) is a non-invasive technique of brain stimulation with a magnetic field applied over the cortex allowing investigation of cortical excitability. Hyperexcitability of contralateral motor cortex has been suggested to be the trigger of focal dystonia. High or low frequency repetitive TMS (rTMS) can induce excitatory or inhibitory lasting effects beyond the time of stimulation and protocols have been developed having either a positive or a negative effect on cortical excitability and associated with prevention of cell death, γ-aminobutyric acid (GABA) interneurons mediated inhibition and brain-derived neurotrophic factor modulation. rTMS studies as a therapeutic strategy of dystonia have been conducted to modulate the cerebral areas involved in the disease. Especially, when applied on the contralateral (pre)-motor cortex or supplementary motor area of brains of small cohorts of dystonic patients, rTMS has shown a beneficial transient clinical effect in association with restrained motor cortex excitability. TMS is currently a valuable tool to improve our understanding of the pathophysiology of dystonia but large controlled studies using sham stimulation are still necessary to delineate the place of rTMS in the therapeutic strategy of dystonia. In this review, we will focus successively on the use of TMS as a tool to better understand pathophysiology, and the use of rTMS as a therapeutic strategy. PMID:27891079

Molecular dynamics approaches to the design and synthesis of PCB targeting molecularly imprinted polymers: interference to monomer-template interactions in imprinting of 1,2,3-trichlorobenzene.

PubMed

Cleland, Dougal; Olsson, Gustaf D; Karlsson, Björn C G; Nicholls, Ian A; McCluskey, Adam

2014-02-07

The interactions between each component of the pre-polymerisation mixtures used in the synthesis of molecularly imprinted polymers (MIP) specific for 1,2,3,4,5-pentachlorobenzene (1) and 1,2,3-trichlorobenzene (2) were examined in four molecular dynamics simulations. These simulations revealed that the relative frequency of functional monomer-template (FM-T) interactions was consistent with results obtained by the synthesis and evaluation of the actual MIPs. The higher frequency of 1 interaction with trimethylstyrene (TMS; 54.7%) than 1 interaction with pentafluorostyrene (PFS; 44.7%) correlated with a higher imprinting factor (IF) of 2.1 vs. 1.7 for each functional monomer respectively. The higher frequency of PFS interactions with 2 (29.6%) than TMS interactions with 2 (1.9%) also correlated well with the observed differences in IF (3.7) of 2 MIPs imprinted using PFS as the FM than the IF (2.8) of 2 MIPs imprinted using TMS as the FM. The TMS-1 interaction dominated the molecular simulation due to high interaction energies, but the weaker TMS-2 resulted in low interaction maintenance, and thus lower IF values. Examination of the other pre-polymerisation mixture components revealed that the low levels of TMS-2 interaction was, in part, due to interference caused by the cross linker (CL) ethyleneglycol dimethylacrylate (EGDMA) interactions with TMS. The main reason was, however, attributed to MeOH interactions with TMS in both a hydrogen bond and perpendicular configuration. This positioned a MeOH directly above the π-orbital of all TMS for an average of 63.8% of MD2 creating significant interference to π-π stacking interactions between 2 and TMS. These findings are consistent with the deviation from the 'normal' molecularly imprinted polymer synthesis ratio of 1 : 4 : 20 (T : FM : CL) of 20 : 1 : 29 and 15 : 6 : 29 observed with 2 and TMS and PFS respectively. Our molecular dynamics simulations correctly predicted the high level of interference from other MIP synthesis components. The effect on PFS-1 interaction by MeOH was significantly lower and thus this system was not adversely affected.

Gas Sensor Test Chip

NASA Technical Reports Server (NTRS)

Buehler, M.; Ryan, M.

1995-01-01

A new test chip is being developed to characterize conducting polymers used in gas sensors. The chip, a seven-layer cofired alumina substrate with gold electrodes, contains 11 comb and U- bend test structures. These structures are designed to measure the sheet resistance, conduction anisotropy, and peripheral conduction of spin-coated films that are not subsequently patterned.

Addendum to Site Assessment and Feasibility of a New Operations Base on the Greenland Ice Sheet: Addendum to Preliminary Report

DTIC Science & Technology

2015-11-01

National Guard PLR Division of Polar Programs SMM /I Special Sensor Microwave/Imager SMMR Scanning Multi-channel Microwave Radiometer ERDC/CRREL...and the Special Sensor Microwave/Imager ( SMM /I). The satellite-based technique uses a difference in the passive microwave brightness temperatures

Investigation of Very Fast Light Detectors: Silicon Photomultiplier and Micro PMT for a Cosmic Ray Array

NASA Astrophysics Data System (ADS)

Cervantes, Omar; Reyes, Liliana; Hooks, Tyler; Perez, Luis; Ritt, Stefan

2016-03-01

To construct a cosmic detector array using 4 scintillation detectors, we investigated 2 recent light sensor technologies from Hamamatsu, as possible readout detectors. First, we investigated several homemade versions of the multipixel photon counter (MPPC) light sensors. These detectors were either biased with internal or external high voltage power supplies. We made extensive measurements to confirm for the coincidence of the MPPC devices. Each sensor is coupled to a wavelength shifting fiber (WSF) that is embedded along a plastic scintillator sheet (30cmx60cmx1/4''). Using energetic cosmic rays, we evaluated several of these homemade detector modules placed above one another in a light proof enclosure. Next, we assembled 2 miniaturized micro photomultiplier (micro PMT), a device recently marketed by Hamamatsu. These sensors showed very fast response times. With 3 WSF embedded in scintillator sheets, we performed coincidence experiments. The detector waveforms were captured using the 5GS/sec domino ring sampler, the DRS4 and our workflow using the CERN PAW package and data analysis results would be presented. Title V Grant.

Ice Sheet Change Detection by Satellite Image Differencing

NASA Technical Reports Server (NTRS)

Bindschadler, Robert A.; Scambos, Ted A.; Choi, Hyeungu; Haran, Terry M.

2010-01-01

Differencing of digital satellite image pairs highlights subtle changes in near-identical scenes of Earth surfaces. Using the mathematical relationships relevant to photoclinometry, we examine the effectiveness of this method for the study of localized ice sheet surface topography changes using numerical experiments. We then test these results by differencing images of several regions in West Antarctica, including some where changes have previously been identified in altimeter profiles. The technique works well with coregistered images having low noise, high radiometric sensitivity, and near-identical solar illumination geometry. Clouds and frosts detract from resolving surface features. The ETM(plus) sensor on Landsat-7, ALI sensor on EO-1, and MODIS sensor on the Aqua and Terra satellite platforms all have potential for detecting localized topographic changes such as shifting dunes, surface inflation and deflation features associated with sub-glacial lake fill-drain events, or grounding line changes. Availability and frequency of MODIS images favor this sensor for wide application, and using it, we demonstrate both qualitative identification of changes in topography and quantitative mapping of slope and elevation changes.

Modulation of the cortical silent period elicited by single- and paired-pulse transcranial magnetic stimulation

PubMed Central

2013-01-01

Background The cortical silent period (CSP) elicited by transcranial magnetic stimulation (TMS) is affected by changes in TMS intensity. Some studies have shown that CSP is shortened or prolonged by short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF), Those studies, however, used different TMS intensities to adjust the amplitude of the motor evoked potential (MEP). Therefore, it is unclear whether changes in CSP duration are induced by changes in TMS intensities or by SICI and ICF. The purpose of this study was to confirm the effects of muscle contractions and stimulus intensities on MEP amplitude and the duration of CSP induced by single-pulse TMS and to clarify the effects of SICI and ICF on CSP duration. MEP evoked by TMS was detected from the right first dorsal interosseous muscle in 15 healthy subjects. First, MEP and CSP were induced by single-pulse TMS with an intensity of 100% active motor threshold (AMT) at four muscle contraction levels [10%, 30%, 50%, and 70% electromyogram (EMG)]. Next, MEP and CSP were induced by seven TMS intensities (100%, 110%, 120%, 130%, 140%, 150%, and 160% AMT) during muscle contraction of 10% EMG. Finally, SICI and ICF were recorded at the four muscle contraction levels (0%, 10%, 30%, and 50% EMG). Results MEP amplitudes increased with increases in muscle contraction and stimulus intensity. However, CSP duration did not differ at different muscle contraction levels and was prolonged with increases in stimulus intensity. CSP was shortened with SICI compared with CSP induced by single-pulse TMS and with ICF at all muscle contraction levels, whereas CSP duration was not significantly changed with ICF. Conclusions We confirmed that CSP duration is affected by TMS intensity but not by the muscle contraction level. This study demonstrated that CSP is shortened with SICI, but it is not altered with ICF. These results indicate that after SICI, CSP duration is affected by the activity of inhibitory intermediate neurons that are activated by the conditioning SICI stimulus. PMID:23547559

No influence of one right-sided prefrontal HF-rTMS session on alcohol craving in recently detoxified alcohol-dependent patients: results of a naturalistic study.

PubMed

Herremans, S C; Baeken, C; Vanderbruggen, N; Vanderhasselt, M A; Zeeuws, D; Santermans, L; De Raedt, R

2012-01-01

Prior research in substance dependence has suggested potential anti-craving effects of repetitive transcranial magnetic stimulation (rTMS) when applied to the dorsolateral prefrontal cortex (DLPFC). However, no single sham-controlled session studies applied to the right DLPFC have been carried-out in recently detoxified alcohol-dependent patients. Furthermore, no studies examined the effect of a single HF-rTMS session on craving in these patients' natural habitat. To further investigate the effect of high-frequency (HF)-rTMS of the right DLPFC on alcohol craving, we performed a prospective, single-blind, sham-controlled study involving 36 hospitalized patients with alcohol dependence syndrome. After successful detoxification, patients were allocated receiving one active or one sham HF-rTMS session. The obsessive-compulsive drinking scale (OCDS) was administered to evaluate the extent of craving just before and after the HF-rTMS session (on Friday), on Saturday and Sunday during the weekend at home, and on Monday when the patient returned to the hospital. One single blind sham-controlled HF-rTMS session applied to the right DLPFC did not result in changes in craving (neither immediately after the stimulation session, nor in patients' natural environment during the weekend). One HF-rTMS stimulation session applied to the right DLPFC had no significant effects on alcohol craving in alcohol dependent patients. One such session could have been too short to alter alcohol craving in a sample of alcohol dependent patients. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Corrosion resistance improvement for 316L stainless steel coronary artery stents by trimethylsilane plasma nanocoatings.

PubMed

Eric Jones, John; Chen, Meng; Yu, Qingsong

2014-10-01

To improve their corrosion resistance and thus long-term biocompatibility, 316L stainless steel coronary artery stents were coated with trimethylsilane (TMS) plasma coatings of 20-25 nm in thickness. Both direct current (DC) and radio-frequency (RF) glow discharges were utilized for TMS plasma coatings and additional NH₃/O₂ plasma treatment to tailor the surface properties. X-ray photoelectron spectroscopy (XPS) was used to characterize the coating surface chemistry. It was found that both DC and RF TMS plasma coatings had Si- and C-rich composition, and the O- and N-contents on the surfaces were substantially increased after NH₃/O₂ plasma treatment. Surface contact angle measurements showed that DC TMS plasma nanocoating with NH₃/O₂ plasma treatment generated very hydrophilic surface. The corrosion resistance of TMS plasma coated stents was evaluated through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization demonstrated that the TMS plasma coated stents imparted higher corrosion potential and pitting potential, as well as lower corrosion current densities as compared with uncoated controls. The surface morphology of stents before and after potentiodynamic polarization testing was analyzed with scanning electron microscopy, which indicated less corrosion on coated stents than uncoated controls. It was also noted that, from EIS data, the hydrophobic TMS plasma nanocoatings showed stable impedance modulus at 0.1 Hz after 21 day immersion in an electrolyte solution. These results suggest improved corrosion resistance of the 316L stainless steel stents by TMS plasma nanocoatings and great promise in reducing and blocking metallic ions releasing into the bloodstream. © 2014 Wiley Periodicals, Inc.

Effects of Hesel-coil deep transcranial magnetic stimulation for depression - a systematic review.

PubMed

Nordenskjöld, Axel; Mårtensson, Björn; Pettersson, Agneta; Heintz, Emelie; Landén, Mikael

2016-10-01

One third of the depressed patients are not improved by antidepressant drugs and psychological treatments, and there is a need for additional treatments. Repetitive transcranial magnetic stimulation (rTMS) is being developed towards an alternative in treatment-resistant depression. Deep transcranial stimulation (dTMS) with the Hesel-coil (H-coil) is a further development of rTMS aiming to enhance the effect by getting the magnetic pulses to penetrate deeper into the brain. This report aims to assess the evidence-base for dTMS for depression. The report also includes an assessment of the ethical and economic aspects involved. A systematic review of the effects of H-coil dTMS on depression was conducted and the scientific support was evaluated using GRADE (Grading of Recommendations Assessment, Development and Evaluation). Only one controlled study was identified. In the sham-controlled randomized study, 212 participants with major depression that had not responded to antidepressant medication were enrolled. A two-point superiority in Hamilton Depression Rating Scale was observed in the dTMS arm vs the sham-arm at 4 weeks, but the difference was not statistically significant. No serious adverse events were reported apart from rare cases of epileptic seizures. The existing scientific support for H-coil dTMS therapy for depression is insufficient. The clinical implication is that the use of dTMS in depression should be restricted to the framework of clinical trials pending further studies. Fortunately, additional studies are underway and the evidence base should presumably improve over the next several years.

Voltage-sensitive dye imaging of transcranial magnetic stimulation-induced intracortical dynamics

PubMed Central

Kozyrev, Vladislav; Eysel, Ulf T.; Jancke, Dirk

2014-01-01

Transcranial magnetic stimulation (TMS) is widely used in clinical interventions and basic neuroscience. Additionally, it has become a powerful tool to drive plastic changes in neuronal networks. However, highly resolved recordings of the immediate TMS effects have remained scarce, because existing recording techniques are limited in spatial or temporal resolution or are interfered with by the strong TMS-induced electric field. To circumvent these constraints, we performed optical imaging with voltage-sensitive dye (VSD) in an animal experimental setting using anaesthetized cats. The dye signals reflect gradual changes in the cells' membrane potential across several square millimeters of cortical tissue, thus enabling direct visualization of TMS-induced neuronal population dynamics. After application of a single TMS pulse across visual cortex, brief focal activation was immediately followed by synchronous suppression of a large pool of neurons. With consecutive magnetic pulses (10 Hz), widespread activity within this “basin of suppression” increased stepwise to suprathreshold levels and spontaneous activity was enhanced. Visual stimulation after repetitive TMS revealed long-term potentiation of evoked activity. Furthermore, loss of the “deceleration–acceleration” notch during the rising phase of the response, as a signature of fast intracortical inhibition detectable with VSD imaging, indicated weakened inhibition as an important driving force of increasing cortical excitability. In summary, our data show that high-frequency TMS changes the balance between excitation and inhibition in favor of an excitatory cortical state. VSD imaging may thus be a promising technique to trace TMS-induced changes in excitability and resulting plastic processes across cortical maps with high spatial and temporal resolutions. PMID:25187557

A Single Session of rTMS Enhances Small-Worldness in Writer's Cramp: Evidence from Simultaneous EEG-fMRI Multi-Modal Brain Graph.

PubMed

Bharath, Rose D; Panda, Rajanikant; Reddam, Venkateswara Reddy; Bhaskar, M V; Gohel, Suril; Bhardwaj, Sujas; Prajapati, Arvind; Pal, Pramod Kumar

2017-01-01

Background and Purpose : Repetitive transcranial magnetic stimulation (rTMS) induces widespread changes in brain connectivity. As the network topology differences induced by a single session of rTMS are less known we undertook this study to ascertain whether the network alterations had a small-world morphology using multi-modal graph theory analysis of simultaneous EEG-fMRI. Method : Simultaneous EEG-fMRI was acquired in duplicate before (R1) and after (R2) a single session of rTMS in 14 patients with Writer's Cramp (WC). Whole brain neuronal and hemodynamic network connectivity were explored using the graph theory measures and clustering coefficient, path length and small-world index were calculated for EEG and resting state fMRI (rsfMRI). Multi-modal graph theory analysis was used to evaluate the correlation of EEG and fMRI clustering coefficients. Result : A single session of rTMS was found to increase the clustering coefficient and small-worldness significantly in both EEG and fMRI ( p < 0.05). Multi-modal graph theory analysis revealed significant modulations in the fronto-parietal regions immediately after rTMS. The rsfMRI revealed additional modulations in several deep brain regions including cerebellum, insula and medial frontal lobe. Conclusion : Multi-modal graph theory analysis of simultaneous EEG-fMRI can supplement motor physiology methods in understanding the neurobiology of rTMS in vivo . Coinciding evidence from EEG and rsfMRI reports small-world morphology for the acute phase network hyper-connectivity indicating changes ensuing low-frequency rTMS is probably not "noise".

Effects of Hesel-coil deep transcranial magnetic stimulation for depression – a systematic review

PubMed Central

Nordenskjöld, Axel; Mårtensson, Björn; Pettersson, Agneta; Heintz, Emelie; Landén, Mikael

2016-01-01

Abstract Background: One third of the depressed patients are not improved by antidepressant drugs and psychological treatments, and there is a need for additional treatments. Repetitive transcranial magnetic stimulation (rTMS) is being developed towards an alternative in treatment-resistant depression. Deep transcranial stimulation (dTMS) with the Hesel-coil (H-coil) is a further development of rTMS aiming to enhance the effect by getting the magnetic pulses to penetrate deeper into the brain. Aims: This report aims to assess the evidence-base for dTMS for depression. The report also includes an assessment of the ethical and economic aspects involved. Methods: A systematic review of the effects of H-coil dTMS on depression was conducted and the scientific support was evaluated using GRADE (Grading of Recommendations Assessment, Development and Evaluation). Results: Only one controlled study was identified. In the sham-controlled randomized study, 212 participants with major depression that had not responded to antidepressant medication were enrolled. A two-point superiority in Hamilton Depression Rating Scale was observed in the dTMS arm vs the sham-arm at 4 weeks, but the difference was not statistically significant. No serious adverse events were reported apart from rare cases of epileptic seizures. Conclusions: The existing scientific support for H-coil dTMS therapy for depression is insufficient. The clinical implication is that the use of dTMS in depression should be restricted to the framework of clinical trials pending further studies. Fortunately, additional studies are underway and the evidence base should presumably improve over the next several years. PMID:27093104

Sensing and actuation system for the University of Florida Torsion Pendulum for LISA

NASA Astrophysics Data System (ADS)

Chilton, Andrew; Shelley, Ryan; Olatunde, Taiwo; Ciani, Giacomo; Conklin, John; Mueller, Guido

2014-03-01

Space-based gravitational wave detectors like LISA are a necessity for understanding the low-frequency portion of the gravitational universe. They use test masses (TMs) which are separated by Gm and are in free fall inside their respective spacecraft. Their relative distance is monitored with laser interferometry at the pm/rtHz level in the LISA band, ranging from 0.1 to 100 mHz. Each TM is enclosed in a housing that provides isolation, capacitive sensing, and electrostatic actuation capabilities. The electronics must both be sensitive at the 1 nm/rtHz level and not induce residual acceleration noise above the requirement for LISA Pathfinder (3*10-15 m/sec2Hz1/2at 3 mHz). Testing and developing this technology is one of the roles of the University of Florida Torsion Pendulum, the only US testbed for LISA-like gravitational reference sensor technology. Our implementation of the sensing system functions by biasing our hollow LISA-like TMs with a 100 kHz sine wave and coupling a pair surrounding electrodes as capacitors to a pair of preamps and a differential amplifier; all other processing is done digitally. Here we report on the design of, implementation of, and preliminary results from the UF Torsion Pendulum.

Neuromodulation and Neurorehabilitation for Treatment of Functional Deficits after TBI Plus PTSD

DTIC Science & Technology

2017-10-01

or not these changes correlate with improving neurobehavioral function. Aim III will examine the effect of rTMS on white fiber tracts and whether or...not the rTMS-related effects correlate with improving neurobehavioral function. Aim IV addresses the need to confirm rTMS safety for severe TBI. 15

Diagnostic procedures for Trend Monitoring System (TMS) communications. [coaxial cable bus system

NASA Technical Reports Server (NTRS)

Brown, J. S.; Lenker, M. D.

1979-01-01

A prototype coaxial cable bus communications sytem was developed to support the trend monitoring system (TMS). Troubleshooting procedures are described at the system level. The procedures can be used by repair personnel to isolate a fault in the TMS and to restore the system to operation by swapping out failed components.

Scripting for Construction of a Transactive Memory System in Multidisciplinary CSCL Environments

ERIC Educational Resources Information Center

Noroozi, Omid; Biemans, Harm J. A.; Weinberger, Armin; Mulder, Martin; Chizari, Mohammad

2013-01-01

Establishing a Transactive Memory System (TMS) is essential for groups of learners, when they are multidisciplinary and collaborate online. Environments for Computer-Supported Collaborative Learning (CSCL) could be designed to facilitate the TMS. This study investigates how various aspects of a TMS (i.e., specialization, coordination, and trust)…

A review of tricaine methanesulfonate for anesthesia of fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, Kathleen M.; Woodley, Christa M.; Brown, Richard S.

2011-01-01

Tricaine methanesulfonate (TMS) is the only FDA approved anesthetic for use in a select number of fish species, including salmonids. It is used widely in hatcheries and research to immobilize fish for marking or transport and to suppress sensory systems during invasive procedures. Improper use can decrease fish viability and possibly distort physiological data. Since animals may be anesthetized by junior staff or students who may have little experience in fish anesthesia, training in the proper use of TMS may decrease variability in results and increase fish survival. This document acts as a primer on the use of TMS formore » anesthetizing juvenile salmonids, with an emphasis on its use in surgical applications. Within, we briefly discuss many aspects TMS. We describe the legal uses for TMS, and what is currently known about the proper storage and preparation of the anesthetic. We outline methods and precautions for administration and changes in fish behavior during progressively deeper anesthesia. We also discuss the physiological effects of TMS and its potential for decreasing fish health.« less

Novel TMS coils designed using an inverse boundary element method

NASA Astrophysics Data System (ADS)

Cobos Sánchez, Clemente; María Guerrero Rodriguez, Jose; Quirós Olozábal, Ángel; Blanco-Navarro, David

2017-01-01

In this work, a new method to design TMS coils is presented. It is based on the inclusion of the concept of stream function of a quasi-static electric current into a boundary element method. The proposed TMS coil design approach is a powerful technique to produce stimulators of arbitrary shape, and remarkably versatile as it permits the prototyping of many different performance requirements and constraints. To illustrate the power of this approach, it has been used for the design of TMS coils wound on rectangular flat, spherical and hemispherical surfaces, subjected to different constraints, such as minimum stored magnetic energy or power dissipation. The performances of such coils have been additionally described; and the torque experienced by each stimulator in the presence of a main magnetic static field have theoretically found in order to study the prospect of using them to perform TMS and fMRI concurrently. The obtained results show that described method is an efficient tool for the design of TMS stimulators, which can be applied to a wide range of coil geometries and performance requirements.

[Ionization in liquids: Request for 1992--1993 funding and 1991--1992 progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-12-31

Studies of the influence of solvent composition on electron mobility, {mu}{sub e}, which we reported for mixtures of neopentane (NP) and tetramethysilane (TMS) were extended to mixtures of TMS with isooctane (i-octane) or cyclohexane (c-hexane). Whereas our initial TMS /NP study focused on an electron transport regime in which {mu}{sub e} varied only from 67 cm{sup 2}/Vs in NP to 100 cm{sup 2}/Vs in TMS, the more recent studies extended to values of {mu}{sub e} of 7.5 and 0.22 cm{sup 2}/Vs in i-octane and c-hexane, respectively. Whereas a linear dependence of log {mu}{sub e} on solvent composition had been foundmore » in earlier studies of electron transport in mixtures, a negative deviation from this dependence was found in TMS/NP mixtures. In contrast, a positive deviation from linearity was observed in TMS/c-hexane mixtures. Despite the markedly different dependences of {mu}{sub e} on solvent composition for these mixtures, the observed dependences are consistent with the percolation model of electron transport that Schiller has developed.« less

Toward large-area roll-to-roll printed nanophotonic sensors

NASA Astrophysics Data System (ADS)

Karioja, Pentti; Hiltunen, Jussi; Aikio, Sanna M.; Alajoki, Teemu; Tuominen, Jarkko; Hiltunen, Marianne; Siitonen, Samuli; Kontturi, Ville; Böhlen, Karl; Hauser, Rene; Charlton, Martin; Boersma, Arjen; Lieberzeit, Peter; Felder, Thorsten; Eustace, David; Haskal, Eliav

2014-05-01

Polymers have become an important material group in fabricating discrete photonic components and integrated optical devices. This is due to their good properties: high optical transmittance, versatile processability at relative low temperatures and potential for low-cost production. Recently, nanoimprinting or nanoimprint lithography (NIL) has obtained a plenty of research interest. In NIL, a mould is pressed against a substrate coated with a moldable material. After deformation of the material, the mold is separated and a replica of the mold is formed. Compared with conventional lithographic methods, imprinting is simple to carry out, requires less-complicated equipment and can provide high-resolution with high throughput. Nanoimprint lithography has shown potential to become a method for low-cost and high-throughput fabrication of nanostructures. We show the development process of nano-structured, large-area multi-parameter sensors using Photonic Crystal (PC) and Surface Enhanced Raman Scattering (SERS) methodologies for environmental and pharmaceutical applications. We address these challenges by developing roll-to-roll (R2R) UV-nanoimprint fabrication methods. Our development steps are the following: Firstly, the proof of concept structures are fabricated by the use of wafer-level processes in Si-based materials. Secondly, the master molds of successful designs are fabricated, and they are used to transfer the nanophotonic structures into polymer materials using sheet-level UV-nanoimprinting. Thirdly, the sheet-level nanoimprinting processes are transferred to roll-to-roll fabrication. In order to enhance roll-to-roll manufacturing capabilities, silicone-based polymer material development was carried out. In the different development phases, Photonic Crystal and SERS sensor structures with increasing complexities were fabricated using polymer materials in order to enhance sheet-level and roll-to-roll manufacturing processes. In addition, chemical and molecular imprint (MIP) functionalization methods were applied in the sensor demonstrators. In this paper, the process flow in fabricating large-area nanophotonic structures by the use of sheet-level and roll-to-roll UV- nanoimprinting is reported.

The efficacy of transcranial magnetic stimulation on migraine: a meta-analysis of randomized controlled trails.

PubMed

Lan, Lihuan; Zhang, Xiaoni; Li, Xiangpen; Rong, Xiaoming; Peng, Ying

2017-08-22

As a non-invasive therapy, whether transcranial magnetic stimulation (TMS) is effective on migraine. This article was aimed to assess the efficacy of TMS on migraine based on randomized controlled trails (RCTs). We searched PubMed, Embase and Cochrane Library electronic databases for published studies which compared TMS group with sham group, conducted a meta-analysis of all RCTs. Five studies, consisting of 313 migraine patients, were identified. Single-pulse transcranial magnetic stimulation is effective for the acute treatment of migraine with aura after the first attack (p = 0.02). And, the efficacy of TMS on chronic migraine was not significant (OR 2.93; 95% CI 0.71-12.15; p = 0.14). TMS is effective for migraine based on the studies included in the article.

Localization of cortical primary motor area of the hand using navigated transcranial magnetic stimulation, BOLD and arterial spin labeling fMRI.

PubMed

Kallioniemi, Elisa; Pitkänen, Minna; Könönen, Mervi; Vanninen, Ritva; Julkunen, Petro

2016-11-01

Although the relationship between neuronavigated transcranial magnetic stimulation (nTMS) and functional magnetic resonance imaging (fMRI) has been widely studied in motor mapping, it is unknown how the motor response type or the choice of motor task affect this relationship. Centers of gravity (CoGs) and response maxima were measured with blood-oxygen-level dependent (BOLD) and arterial spin labeling (ASL) fMRI during motor tasks against nTMS CoGs and response maxima, which were mapped with motor evoked potentials (MEPs) and silent periods (SPs). No differences in motor representations (CoGs and response maxima) were observed in lateral-medial direction (p=0.265). fMRI methods localized the motor representation more posterior than nTMS (p<0.001). This was not affected by the BOLD fMRI motor task (p>0.999) nor nTMS response type (p>0.999). ASL fMRI maxima did not differ from the nTMS nor BOLD fMRI CoGs (p≥0.070), but the ASL CoG was deeper in comparison to other methods (p≤0.042). The BOLD fMRI motor task did not influence the depth of the motor representation (p≥0.745). The median Euclidean distances between the nTMS and fMRI motor representations varied between 7.7mm and 14.5mm and did not differ between the methods (F≤1.23, p≥0.318). The relationship between fMRI and nTMS mapped excitatory (MEP) and inhibitory (SP) responses, and whether the choice of motor task affects this relationship, have not been studied before. The congruence between fMRI and nTMS is good. The choice of nTMS motor response type nor BOLD fMRI motor task had no effect on this relationship. Copyright © 2016 Elsevier B.V. All rights reserved.

Elevated prefrontal cortex GABA in patients with major depressive disorder after TMS treatment measured with proton magnetic resonance spectroscopy.

PubMed

Dubin, Marc J; Mao, Xiangling; Banerjee, Samprit; Goodman, Zachary; Lapidus, Kyle A B; Kang, Guoxin; Liston, Conor; Shungu, Dikoma C

2016-04-01

GABAergic and glutamatergic neurotransmitter systems are central to the pathophysiology of depression and are potential targets of repetitive transcranial magnetic stimulation (rTMS). We assessed the effect of 10-Hz rTMS over the left dorsolateral prefrontal cortex (DLPFC) of patients with major depressive disorder on the levels of medial prefrontal cortex (MPFC) γ-aminobutyric acid (GABA) and the combined resonance of glutamate and glutamine (Glx) as assessed in vivo with proton magnetic resonance spectroscopy ((1)H MRS). Currently depressed individuals between the ages of 23 and 68 years participated in a 5-week naturalistic, open-label treatment study of rTMS, with (1)H MRS measurements of MPFC GABA and Glx levels at baseline and following 5 weeks of the rTMS intervention. We applied rTMS pulses over the left DLPFC at 10 Hz and 80%-120% of motor threshold for 25 daily sessions, with each session consisting of 3000 pulses. We assessed therapeutic response using the 24-item Hamilton Rating Scale for Depression (HAMD24). The GABA and Glx levels are expressed as ratios of peak areas relative to the area of the synchronously acquired and similarly fitted unsuppressed voxel water signal (W). Twenty-three currently depressed individuals (7 men) participated in the study. GABA/W in the MPFC increased 13.8% (p = 0.013) in all depressed individuals. There were no significant effects of rTMS on Glx/W. GABA/W and Glx/W were highly correlated in severely depressed patients at baseline but not after TMS. The primary study limitations are the open-label design and the inclusion of participants currently taking stable regimens of antidepressant medications. These results implicate GABAergic and glutamatergic systems in the mechanism of action of rTMS for major depression, warranting further investigation in larger samples.

Number of pulses or number of sessions? An open-label study of trajectories of improvement for once-vs. twice-daily dorsomedial prefrontal rTMS in major depression.

PubMed

Schulze, Laura; Feffer, Kfir; Lozano, Christopher; Giacobbe, Peter; Daskalakis, Zafiris J; Blumberger, Daniel M; Downar, Jonathan

Repetitive transcranial magnetic stimulation (rTMS) shows efficacy in the treatment of major depressive episodes (MDEs), but can require ≥4-6 weeks for maximal effect. Recent studies suggest that multiple daily sessions of rTMS can accelerate response without reducing therapeutic efficacy. However, it is unresolved whether therapeutic effects track cumulative number of pulses, or cumulative number of sessions. This open-label study reviewed clinical outcomes over a 20-30 session course of high-frequency bilateral dorsomedial prefrontal cortex (DMPFC)-rTMS among patients receiving 6000 pulses/day delivered either in twice-daily sessions 80 min apart (at 20 Hz) or single, longer, once-daily sessions (at 10 Hz). A retrospective chart review identified 130 MDD patients who underwent 20-30 daily sessions of bilateral DMPFC-rTMS (Once-daily, n = 65; Twice-daily, n = 65) at a single Canadian clinic. Mixed-effects modeling revealed significantly faster improvement (group-by-time interaction) for twice-daily versus once-daily DMPFC-rTMS. Across both groups, the pace of improvement showed a consistent relationship with number of cumulative sessions, but not with cumulative number of pulses. Although the twice-daily group completed treatment in half as many days, final clinical outcomes did not differ significantly between groups on dichotomous measures (response/remission rates: once-daily, 35.4%/33.8%; twice-daily, 41.5%/35.4%), or continuous measures, or on overall response distribution. Twice-daily rTMS appears feasible, tolerable, and capable of achieving comparable results to once-daily rTMS, while also reducing course length approximately twofold. Therapeutic gains tracked the cumulative number of sessions, not pulses. Future randomized studies comparing once-daily to multiple-daily rTMS sessions, while controlling for number of pulses, may be warranted. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

High-frequency repetitive transcranial magnetic stimulation over the left DLPFC for major depression: Session-dependent efficacy: A meta-analysis.

PubMed

Teng, S; Guo, Z; Peng, H; Xing, G; Chen, H; He, B; McClure, M A; Mu, Q

2017-03-01

Depression is a major debilitating psychiatric disorder. Current antidepressant drugs are often associated with side effects or treatment resistance. The aim of this meta-analysis was to evaluate therapeutic effects of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) in major depression (MD). The medical data bases of PubMed, Medline, Embase and Cochrane Central Register were searched for randomized controlled trials (RCTs) reporting the therapeutic effects of high-frequency rTMS for depression, which were published in English between January 1990 and June 2016. The index terms were "depress*", "depression" and "transcranial magnetic stimulation". Depression outcome data of different sessions (5, 10, 15, and 20 sessions of rTMS treatment) were extracted and synthesized by calculating standardized mean difference (SMD) with 95% confidence intervals (CI) by using a random-effect model. Within each session group, the subgroup analyses based on the number of pulses (≤1000, 1200-1500, 1600-1800, and 2000-3000) were also conducted. Thirty RCTs with a total of 1754 subjects including 1136 in the rTMS group and 618 in the sham group were included in this meta-analysis. rTMS had a significant overall therapeutic effect on depression severity scores (SMD=-0.73, P<0.00001). The five, 10, 15, 20 sessions of rTMS treatments yielded the significant mean effect sizes of -0.43, -0.60, -1.13, and -2.74, respectively. In the four groups (5, 10, 15, 20 sessions), the maximal mean effect size was all obtained in the subgroup of 1200-1500 pulses per day (-0.97, -1.14, -1.91, -5.47; P<0.05). The increasing of HF-rTMS sessions is associated with the increased efficacy of HF-rTMS in reducing depressed patients' symptom severity. A total number of pulses of 1200-1500 per day appear to deliver the best antidepressant effects of HF-rTMS. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Motor Cortex Reorganization and Repetitive Transcranial Magnetic Stimulation for Pain-A Methodological Study.

PubMed

Nurmikko, Turo; MacIver, Kathryn; Bresnahan, Rebecca; Hird, Emily; Nelson, Andrew; Sacco, Paul

2016-10-01

Somatotopic reorganization of primary motor cortex (M1) has been described in several neurological conditions associated with chronic pain. We hypothesized that such reorganization impacts on the mechanisms of M1 stimulation induced analgesia and may either compromise the treatment effect of or provide an alternative target site for repetitive transcranial magnetic stimulation (rTMS). The aim of the study was to compare pain relief following rTMS of the standard motor "hotspot" with that of the reorganized area. We used TMS motor mapping in 30 patients to establish the location of the standard motor "hotspot" (site A) and an alternative site located in the reorganized area (site B), both within M1. Where TMS mapping was not possible (N = 8) we determined the location of the two sites using task-related fMRI. We compared the analgesic effect on neuropathic pain of 5 sessions of navigated rTMS applied over (i) site A, (ii) site B, and (iii) occipital fissure (SHAM stimulation site). Total Pain Relief (TOTPAR) was determined as the difference in average weekly pain scores between baseline and following each rTMS cycle, over three weeks. Data from 27 patients was analyzed. rTMS of sites A and B resulted in greater TOTPAR than that of SHAM. No difference was seen between sites A and B. Responders (≥15% pain relief) were seen in both groups, with partial overlap only. Addition of stimulation over site B improved the responder rate by 58% compared with site A. In an open-label extension study of five sessions of rTMS aimed at the optimized target site, 8/11 responders and 1/12 nonresponders reported pain relief. Cortical reorganization may provide a more effective stimulation target for rTMS in some individuals with neuropathic pain. © 2016 International Neuromodulation Society.

Modulating phonemic fluency performance in healthy subjects with transcranial magnetic stimulation over the left or right lateral frontal cortex.

PubMed

Smirni, Daniela; Turriziani, Patrizia; Mangano, Giuseppa Renata; Bracco, Martina; Oliveri, Massimiliano; Cipolotti, Lisa

2017-07-28

A growing body of evidence have suggested that non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), can improve the performance of aphasic patients in language tasks. For example, application of inhibitory rTMS or tDCs over the right frontal lobe of dysphasic patients resulted in improved naming abilities. Several studies have also reported that in healthy controls (HC) tDCS application over the left prefrontal cortex (PFC) improve performance in naming and semantic fluency tasks. The aim of this study was to investigate in HC, for the first time, the effects of inhibitory repetitive TMS (rTMS) over left and right lateral frontal cortex (BA 47) on two phonemic fluency tasks (FAS or FPL). 44 right-handed HCs were administered rTMS or sham over the left or right lateral frontal cortex in two separate testing sessions, with a 24h interval, followed by the two phonemic fluency tasks. To account for possible practice effects, an additional 22 HCs were tested on only the phonemic fluency task across two sessions with no stimulation. We found that rTMS-inhibition over the left lateral frontal cortex significantly worsened phonemic fluency performance when compared to sham. In contrast, rTMS-inhibition over the right lateral frontal cortex significantly improved phonemic fluency performance when compared to sham. These results were not accounted for practice effects. We speculated that rTMS over the right lateral frontal cortex may induce plastic neural changes to the left lateral frontal cortex by suppressing interhemispheric inhibitory interactions. This resulted in an increased excitability (disinhibition) of the contralateral unstimulated left lateral frontal cortex, consequently enhancing phonemic fluency performance. Conversely, application of rTMS over the left lateral frontal cortex may induce a temporary, virtual lesion, with effects similar to those reported in left frontal patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Equivalent brain SPECT perfusion changes underlying therapeutic efficiency in pharmacoresistant depression using either high-frequency left or low-frequency right prefrontal rTMS.

PubMed

Richieri, Raphaëlle; Boyer, Laurent; Padovani, Romain; Adida, Marc; Colavolpe, Cécile; Mundler, Olivier; Lançon, Christophe; Guedj, Eric

2012-12-03

Functional neuroimaging studies have suggested similar mechanisms underlying antidepressant effects of distinct therapeutics. This study aimed to determine and compare functional brain patterns underlying the antidepressant response of 2 distinct protocols of repetitive transcranial magnetic stimulation (rTMS). 99mTc-ECD SPECT was performed before and after rTMS of dorsolateral prefrontal cortex in 61 drug-resistant right-handed patients with major depression, using high frequency (10Hz) left-side stimulation in 33 patients, and low frequency (1Hz) right-side stimulation in 28 patients. Efficiency of rTMS response was defined as at least 50% reduction of the baseline Beck Depression Inventory score. We compared the whole-brain voxel-based brain SPECT changes in perfusion after rTMS, between responders and non-responders in the whole sample (p<0.005, uncorrected), and separately in the subgroup of patients with left- and right-stimulation. Before rTMS, the left- and right-prefrontal stimulation groups did not differ from clinical data and brain SPECT perfusion. rTMS efficiency (evaluated on % of responders) was statistically equivalent in the two groups of patients. In the whole-group of responder patients, a perfusion decrease was found after rTMS, in comparison to non-responders, within the left perirhinal cortex (BA35, BA36). This result was secondarily confirmed separately in the two subgroups, i.e. after either left stimulation (p=0.017) or right stimulation (p<0.001), without significant perfusion differences between these two subgroups. These data show that distinct successful rTMS protocols induce equivalent brain functional changes associated to antidepressive efficiency, consisting to a remote brain limbic activity decrease within the left perirhinal cortex. However, these results will have to be confirmed in a double-blind randomized trial using a sham control group. Copyright © 2012 Elsevier Inc. All rights reserved.

Elevated prefrontal cortex GABA in patients with major depressive disorder after TMS treatment measured with proton magnetic resonance spectroscopy

PubMed Central

Dubin, Marc J.; Mao, Xiangling; Banerjee, Samprit; Goodman, Zachary; Lapidus, Kyle A.B.; Kang, Guoxin; Liston, Conor; Shungu, Dikoma C.

2016-01-01

Background GABAergic and glutamatergic neurotransmitter systems are central to the pathophysiology of depression and are potential targets of repetitive transcranial magnetic stimulation (rTMS). We assessed the effect of 10-Hz rTMS over the left dorsolateral prefrontal cortex (DLPFC) of patients with major depressive disorder on the levels of medial prefrontal cortex (MPFC) γ-aminobutyric acid (GABA) and the combined resonance of glutamate and glutamine (Glx) as assessed in vivo with proton magnetic resonance spectroscopy (1H MRS). Methods Currently depressed individuals between the ages of 23 and 68 years participated in a 5-week naturalistic, open-label treatment study of rTMS, with 1H MRS measurements of MPFC GABA and Glx levels at baseline and following 5 weeks of the rTMS intervention. We applied rTMS pulses over the left DLPFC at 10 Hz and 80%–120% of motor threshold for 25 daily sessions, with each session consisting of 3000 pulses. We assessed therapeutic response using the 24-item Hamilton Rating Scale for Depression (HAMD24). The GABA and Glx levels are expressed as ratios of peak areas relative to the area of the synchronously acquired and similarly fitted unsuppressed voxel water signal (W). Results Twenty-three currently depressed individuals (7 men) participated in the study. GABA/W in the MPFC increased 13.8% (p = 0.013) in all depressed individuals. There were no significant effects of rTMS on Glx/W. GABA/W and Glx/W were highly correlated in severely depressed patients at baseline but not after TMS. Limitations The primary study limitations are the open-label design and the inclusion of participants currently taking stable regimens of antidepressant medications. Conclusion These results implicate GABAergic and glutamatergic systems in the mechanism of action of rTMS for major depression, warranting further investigation in larger samples. PMID:26900793

rTMS in fibromyalgia: a randomized trial evaluating QoL and its brain metabolic substrate.

PubMed

Boyer, Laurent; Dousset, Alix; Roussel, Philippe; Dossetto, Nathalie; Cammilleri, Serge; Piano, Virginie; Khalfa, Stéphanie; Mundler, Olivier; Donnet, Anne; Guedj, Eric

2014-04-08

This double-blind, randomized, placebo-controlled study investigated the impact of repetitive transcranial magnetic stimulation (rTMS) on quality of life (QoL) of patients with fibromyalgia, and its possible brain metabolic substrate. Thirty-eight patients were randomly assigned to receive high-frequency rTMS (n = 19) or sham stimulation (n = 19), applied to left primary motor cortex in 14 sessions over 10 weeks. Primary clinical outcomes were QoL changes at the end of week 11, measured using the Fibromyalgia Impact Questionnaire (FIQ). Secondary clinical outcomes were mental and physical QoL component measured using the 36-Item Short Form Health Survey (SF-36), but also pain, mood, and anxiety. Resting-state [(18)F]-fluorodeoxyglucose-PET metabolism was assessed at baseline, week 2, and week 11. Whole-brain voxel-based analysis was performed to study between-group metabolic changes over time. At week 11, patients of the active rTMS group had greater QoL improvement in the FIQ (p = 0.032) and in the mental component of the SF-36 (p = 0.019) than the sham stimulation group. No significant impact was found for other clinical outcomes. Compared with the sham stimulation group, patients of the active rTMS group presented an increase in right medial temporal metabolism between baseline and week 11 (p < 0.001), which was correlated with FIQ and mental component SF-36 concomitant changes (r = -0.38, p = 0.043; r = 0.51, p = 0.009, respectively). QoL improvement involved mainly affective, emotional, and social dimensions. Our study shows that rTMS improves QoL of patients with fibromyalgia. This improvement is associated with a concomitant increase in right limbic metabolism, arguing for a neural substrate to the impact of rTMS on emotional dimensions involved in QoL. This study provides Class II evidence that rTMS compared with sham rTMS improves QoL in patients with fibromyalgia.

Calculating the electric field in real human head by transcranial magnetic stimulation with shield plate

NASA Astrophysics Data System (ADS)

Lu, Mai; Ueno, Shoogo

2009-04-01

In this paper, we present a transcranial magnetic stimulation (TMS) system by incorporating a conductive shield plate. The magnetic field, induced current density, and electric field in a real human head were calculated by impedance method and the results were compared with TMS without shielding. Our results show that the field localization can be improved by introducing a conductive shield plate; the stimulation magnitude (depth) in the brain is reduced comparing with the TMS without shielding. The strong magnetic field near the TMS coil is difficult to be efficiently shielded by a thinner conductive shield plate.

Transcranial magnetic stimulation: physics, electrophysiology, and applications.

PubMed

Fatemi-Ardekani, Ali

2008-01-01

Transcranial magnetic stimulation (TMS) is a noninvasive technique used to stimulate the brain. This review will examine the fundamental principles of physics upon which magnetic stimulation is based, the design considerations of the TMS device, and hypotheses about its electrophysiological effects resulting in neuromodulation. TMS is valuable in neurophysiology research and has significant therapeutic potential in clinical neurology and psychiatry. While TMS can modify neuronal currents in the brain, its underlying mechanism remains unknown. Salient applications are included and some suggestions are outlined for future development of magnetic stimulators that could lead to more effective neuronal stimulation and therefore better therapeutic and diagnostic applications.

Ionic skin.

PubMed

Sun, Jeong-Yun; Keplinger, Christoph; Whitesides, George M; Suo, Zhigang

2014-12-03

Electronic skins (i.e., stretchable sheets of distributed sensors) report signals using electrons, whereas natural skins report signals using ions. Here, ionic conductors are used to create a new type of sensory sheet, called "ionic skin". Ionic skins are highly stretchable, transparent, and biocompatible. They readily measure strains from 1% to 500%, and pressures as low as 1 kPa. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High‐Performance Lithium‐Oxygen Battery Electrolyte Derived from Optimum Combination of Solvent and Lithium Salt

PubMed Central

Ahn, Su Mi; Suk, Jungdon; Kim, Do Youb; Kim, Hwan Kyu

2017-01-01

Abstract To fabricate a sustainable lithium‐oxygen (Li‐O2) battery, it is crucial to identify an optimum electrolyte. Herein, it is found that tetramethylene sulfone (TMS) and lithium nitrate (LiNO3) form the optimum electrolyte, which greatly reduces the overpotential at charge, exhibits superior oxygen efficiency, and allows stable cycling for 100 cycles. Linear sweep voltammetry (LSV) and differential electrochemical mass spectrometry (DEMS) analyses reveal that neat TMS is stable to oxidative decomposition and exhibit good compatibility with a lithium metal. But, when TMS is combined with typical lithium salts, its performance is far from satisfactory. However, the TMS electrolyte containing LiNO3 exhibits a very low overpotential, which minimizes the side reactions and shows high oxygen efficiency. LSV‐DEMS study confirms that the TMS‐LiNO3 electrolyte efficiently produces NO2 −, which initiates a redox shuttle reaction. Interestingly, this NO2 −/NO2 redox reaction derived from the LiNO3 salt is not very effective in solvents other than TMS. Compared with other common Li‐O2 solvents, TMS seems optimum solvent for the efficient use of LiNO3 salt. Good compatibility with lithium metal, high dielectric constant, and low donicity of TMS are considered to be highly favorable to an efficient NO2 −/NO2 redox reaction, which results in a high‐performance Li‐O2 battery. PMID:29051863

Cognitive effects of bilateral high frequency repetitive transcranial magnetic stimulation in early phase psychosis: a pilot study.

PubMed

Francis, Michael M; Hummer, Tom A; Vohs, Jenifer L; Yung, Matthew G; Visco, Andrew C; Mehdiyoun, Nikki F; Kulig, Teresa C; Um, Miji; Yang, Ziyi; Motamed, Mehrdad; Liffick, Emily; Zhang, Ying; Breier, Alan

2018-05-31

Cognitive dysfunction is a core facet of schizophrenia that is present early in the course of the illness and contributes to diminished functioning and outcomes. Repetitive transcranial magnetic stimulation (rTMS) is a relatively new neuropsychiatric intervention. Initially used in treatment resistant depression, investigators are now studying rTMS for other psychiatric diseases such as schizophrenia. In this study we examined the effect of high frequency rTMS on cognitive function in a group of individuals with early phase psychosis. Twenty subjects were randomized (1:1) in double-blind fashion to rTMS or sham condition. Over two weeks subjects underwent ten sessions of high frequency, bilateral, sequential rTMS targeting the dorsolateral prefrontal cortex (DLPFC). Prior to beginning and following completion of study treatment, subjects completed a cognitive assessment and magnetic resonance imaging. Subjects receiving rTMS, compared to sham treatment, displayed improvement on a standardized cognitive battery both immediately following the course of study treatment and at follow-up two weeks later. Imaging results revealed that left frontal cortical thickness at baseline was correlated with treatment response. The study treatment was found to be safe and well tolerated. These results suggest that rTMS may hold promise for the treatment of cognitive dysfunction in the early phase of psychosis, and that MRI may provide biomarkers predicting response to the treatment.

Low-Frequency rTMS Ameliorates Autistic-Like Behaviors in Rats Induced by Neonatal Isolation Through Regulating the Synaptic GABA Transmission

PubMed Central

Tan, Tao; Wang, Wei; Xu, Haitao; Huang, Zhilin; Wang, Yu Tian; Dong, Zhifang

2018-01-01

Patients with autism spectrum disorder (ASD) display abnormalities in neuronal development, synaptic function and neural circuits. The imbalance of excitatory and inhibitory (E/I) synaptic transmission has been proposed to cause the main behavioral characteristics of ASD. Repetitive transcranial magnetic stimulation (rTMS) can directly or indirectly induce excitability and synaptic plasticity changes in the brain noninvasively. However, whether rTMS can ameliorate autistic-like behaviors in animal model via regulating the balance of E/I synaptic transmission is unknown. By using our recent reported animal model with autistic-like behaviors induced by neonatal isolation (postnatal days 1–9), we found that low-frequency rTMS (LF-rTMS, 1 Hz) treatment for 2 weeks effectively alleviated the acquired autistic-like symptoms, as reflected by an increase in social interaction and decrease in self-grooming, anxiety- and depressive-like behaviors in young adult rats compared to those in untreated animals. Furthermore, the amelioration in autistic-like behavior was accompanied by a restoration of the balance between E/I activity, especially at the level of synaptic transmission and receptors in synaptosomes. These findings indicated that LF-rTMS may alleviate the symptoms of ASD-like behaviors caused by neonatal isolation through regulating the synaptic GABA transmission, suggesting that LF-rTMS may be a potential therapeutic technique to treat ASD. PMID:29541022

Test-retest assessment of cortical activation induced by repetitive transcranial magnetic stimulation with brain atlas-guided optical topography

NASA Astrophysics Data System (ADS)

Tian, Fenghua; Kozel, F. Andrew; Yennu, Amarnath; Croarkin, Paul E.; McClintock, Shawn M.; Mapes, Kimberly S.; Husain, Mustafa M.; Liu, Hanli

2012-11-01

Repetitive transcranial magnetic stimulation (rTMS) is a technology that stimulates neurons with rapidly changing magnetic pulses with demonstrated therapeutic applications for various neuropsychiatric disorders. Functional near-infrared spectroscopy (fNIRS) is a suitable tool to assess rTMS-evoked brain responses without interference from the magnetic or electric fields generated by the TMS coil. We have previously reported a channel-wise study of combined rTMS/fNIRS on the motor and prefrontal cortices, showing a robust decrease of oxygenated hemoglobin concentration (Δ[HbO2]) at the sites of 1-Hz rTMS and the contralateral brain regions. However, the reliability of this putative clinical tool is unknown. In this study, we develop a rapid optical topography approach to spatially characterize the rTMS-evoked hemodynamic responses on a standard brain atlas. A hemispherical approximation of the brain is employed to convert the three-dimensional topography on the complex brain surface to a two-dimensional topography in the spherical coordinate system. The test-retest reliability of the combined rTMS/fNIRS is assessed using repeated measurements performed two to three days apart. The results demonstrate that the Δ[HbO2] amplitudes have moderate-to-high reliability at the group level; and the spatial patterns of the topographic images have high reproducibility in size and a moderate degree of overlap at the individual level.

Predictive value of dorso-lateral prefrontal connectivity for rTMS response in treatment-resistant depression: A brain perfusion SPECT study.

PubMed

Richieri, Raphaëlle; Verger, Antoine; Boyer, Laurent; Boucekine, Mohamed; David, Anthony; Lançon, Christophe; Cermolacce, Michel; Guedj, Eric

2018-05-18

Previous clinical trials have suggested that repetitive transcranial magnetic stimulation (rTMS) has a significant antidepressant effect in patients with treatment resistant depression (TRD). However, results remain heterogeneous with many patients without effective response. The aim of this SPECT study was to determine before treatment the predictive value of the connectivity of the stimulated area on further rTMS response in patients with TRD. Fifty-eight TRD patients performed a brain perfusion SPECT before high frequency rTMS of the left dorsolateral prefrontal cortex (DLPFC). A voxel based-analysis was achieved to compare connectivity of the left DLPFC in responders and non-responders using inter-regional correlations (p < 0.005, corrected for cluster volume). A multiple logistic regression model was thereafter used with the goal of establishing a predictive score. Before rTMS, responders exhibited increased SPECT connectivity between the left DLPFC and the right cerebellum in comparison to non-responders, independently of age, gender, severity of depression, and severity of treatment resistance. The area under the curve for the combination of these two SPECT clusters to predict rTMS response was 0.756 (p < 0.005). SPECT connectivity of the left DLPFC predicts rTMS response before treatment. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

Efficacy of Add-On Deep Transcranial Magnetic Stimulation in Comorbid Alcohol Dependence and Dysthymic Disorder: Three Case Reports

PubMed Central

Rapinesi, Chiara; Serata, Daniele; Casale, Antonio Del; Bersani, Francesco S.; Solfanelli, Andrea; Scatena, Paola; Raccah, Ruggero N.; Brugnoli, Roberto; Digiacomantonio, Vittorio; Carbonetti, Paolo; Fensore, Claudio; Tatarelli, Roberto; Angeletti, Gloria; Ferracuti, Stefano; Girardi, Paolo

2013-01-01

Background: Craving for alcohol is associated with abnormal activation in the dorsolateral prefrontal cortex. Deep transcranial magnetic stimulation (dTMS) has shown promise in the treatment of depression. There are few treatment options for treatment-resistant dysthymic disorder comorbid with alcohol use disorder. Objective: To investigate the possible anticraving efficacy of bilateral dorsolateral prefrontal cortex high-frequency dTMS in 3 patients with comorbid long-term DSM-IV-TR dysthymic disorder and alcohol use disorder. Method: Three patients with alcohol use disorder with dysthymic disorder in their detoxification phase (abstaining for > 1 month) underwent twenty 20-minute sessions of 20 Hz dTMS over the dorsolateral prefrontal cortex over 28 days between 2011 and 2012. Alcohol craving was rated with the Obsessive Compulsive Drinking Scale and depressive symptoms with the Hamilton Depression Rating Scale. Results: All 3 patients responded unsatisfactorily to initial intravenous antidepressant and antianxiety combinations but responded after 10 dTMS sessions, improving on both anxiety-depressive symptoms and craving. This improvement enabled us to reduce antidepressant dosages after dTMS cycle completion. Discussion: High-frequency bilateral dorsolateral prefrontal cortex dTMS with left prevalence was found to produce significant anticraving effects in alcohol use disorder comorbid with dysthymic disorder. The potential of dTMS for reducing craving in patients with substance use disorder deserves to be further investigated. PMID:23724355

Efficacy of add-on deep transcranial magnetic stimulation in comorbid alcohol dependence and dysthymic disorder: three case reports.

PubMed

Rapinesi, Chiara; Kotzalidis, Georgios D; Serata, Daniele; Del Casale, Antonio; Bersani, Francesco S; Solfanelli, Andrea; Scatena, Paola; Raccah, Ruggero N; Brugnoli, Roberto; Digiacomantonio, Vittorio; Carbonetti, Paolo; Fensore, Claudio; Tatarelli, Roberto; Angeletti, Gloria; Ferracuti, Stefano; Girardi, Paolo

2013-01-01

Craving for alcohol is associated with abnormal activation in the dorsolateral prefrontal cortex. Deep transcranial magnetic stimulation (dTMS) has shown promise in the treatment of depression. There are few treatment options for treatment-resistant dysthymic disorder comorbid with alcohol use disorder. To investigate the possible anticraving efficacy of bilateral dorsolateral prefrontal cortex high-frequency dTMS in 3 patients with comorbid long-term DSM-IV-TR dysthymic disorder and alcohol use disorder. Three patients with alcohol use disorder with dysthymic disorder in their detoxification phase (abstaining for > 1 month) underwent twenty 20-minute sessions of 20 Hz dTMS over the dorsolateral prefrontal cortex over 28 days between 2011 and 2012. Alcohol craving was rated with the Obsessive Compulsive Drinking Scale and depressive symptoms with the Hamilton Depression Rating Scale. All 3 patients responded unsatisfactorily to initial intravenous antidepressant and antianxiety combinations but responded after 10 dTMS sessions, improving on both anxiety-depressive symptoms and craving. This improvement enabled us to reduce antidepressant dosages after dTMS cycle completion. High-frequency bilateral dorsolateral prefrontal cortex dTMS with left prevalence was found to produce significant anticraving effects in alcohol use disorder comorbid with dysthymic disorder. The potential of dTMS for reducing craving in patients with substance use disorder deserves to be further investigated.

Meta-analysis of the effects of repetitive transcranial magnetic stimulation (rTMS) on negative and positive symptoms in schizophrenia

PubMed Central

Freitas, Catarina; Fregni, Felipe; Pascual-Leone, Alvaro

2009-01-01

Background A growing body of evidence suggests that repetitive transcranial magnetic stimulation (rTMS) can alleviate negative and positive symptoms of refractory schizophrenia. However, trials to date have been small and results are mixed. Methods We performed meta-analyses of all prospective studies of the therapeutic application of rTMS in refractory schizophrenia assessing the effects of high-frequency rTMS to the left dorsolateral prefrontal cortex (DLPFC) to treat negative symptoms, and low-frequency rTMS to the left temporo-parietal cortex (TPC) to treat auditory hallucinations (AH) and overall positive symptoms. Results When analyzing controlled (active arms) and uncontrolled studies together, the effect sizes showed significant and moderate effects of rTMS on negative and positive symptoms (based on PANSS-N or SANS, and PANSS-P or SAPS, respectively). However, the analysis for the sham-controlled studies revealed a small non-significant effect size for negative (0.27, p=0.417) and for positive symptoms (0.17, p=0.129). When specifically analyzing AH (based on AHRS, HCS or SAH), the effect size for the sham-controlled studies was large and significant (1.04; p=0.002). Conclusions These meta-analyses support the need for further controlled, larger trials to assess the clinical efficacy of rTMS on negative and positive symptoms of schizophrenia, while suggesting the need for exploration for alternative stimulation protocols. PMID:19138833

Modulating Brain Connectivity by Simultaneous Dual-Mode Stimulation over Bilateral Primary Motor Cortices in Subacute Stroke Patients.

PubMed

Lee, Jungsoo; Park, Eunhee; Lee, Ahee; Chang, Won Hyuk; Kim, Dae-Shik; Shin, Yong-Il; Kim, Yun-Hee

2018-01-01

Repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) has been used for the modulation of stroke patients' motor function. Recently, more challenging approaches have been studied. In this study, simultaneous stimulation using both rTMS and tDCS (dual-mode stimulation) over bilateral primary motor cortices (M1s) was investigated to compare its modulatory effects with single rTMS stimulation over the ipsilesional M1 in subacute stroke patients. Twenty-four patients participated; 12 participants were assigned to the dual-mode stimulation group while the other 12 participants were assigned to the rTMS-only group. We assessed each patient's motor function using the Fugl-Meyer assessment score and acquired their resting-state fMRI data at two times: prior to stimulation and 2 months after stimulation. Twelve healthy subjects were also recruited as the control group. The interhemispheric connectivity of the contralesional M1, interhemispheric connectivity between bilateral hemispheres, and global efficiency of the motor network noticeably increased in the dual-mode stimulation group compared to the rTMS-only group. Contrary to the dual-mode stimulation group, there was no significant change in the rTMS-only group. These data suggested that simultaneous dual-mode stimulation contributed to the recovery of interhemispheric interaction than rTMS only in subacute stroke patients. This trial is registered with NCT03279640.

Modulating Brain Connectivity by Simultaneous Dual-Mode Stimulation over Bilateral Primary Motor Cortices in Subacute Stroke Patients

PubMed Central

Park, Eunhee; Lee, Ahee; Chang, Won Hyuk; Kim, Dae-Shik

2018-01-01

Repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) has been used for the modulation of stroke patients' motor function. Recently, more challenging approaches have been studied. In this study, simultaneous stimulation using both rTMS and tDCS (dual-mode stimulation) over bilateral primary motor cortices (M1s) was investigated to compare its modulatory effects with single rTMS stimulation over the ipsilesional M1 in subacute stroke patients. Twenty-four patients participated; 12 participants were assigned to the dual-mode stimulation group while the other 12 participants were assigned to the rTMS-only group. We assessed each patient's motor function using the Fugl-Meyer assessment score and acquired their resting-state fMRI data at two times: prior to stimulation and 2 months after stimulation. Twelve healthy subjects were also recruited as the control group. The interhemispheric connectivity of the contralesional M1, interhemispheric connectivity between bilateral hemispheres, and global efficiency of the motor network noticeably increased in the dual-mode stimulation group compared to the rTMS-only group. Contrary to the dual-mode stimulation group, there was no significant change in the rTMS-only group. These data suggested that simultaneous dual-mode stimulation contributed to the recovery of interhemispheric interaction than rTMS only in subacute stroke patients. This trial is registered with NCT03279640. PMID:29666636

Trimethylsilyl speciations of cathine, cathinone and norephedrine followed by gas chromatography mass spectrometry: Direct sample preparation and analysis of khatamines.

PubMed

Molnár, Borbála; Fodor, Blanka; Boldizsár, Imre; Molnár-Perl, Ibolya

2016-04-01

A literature criticism is given on methods using currently gas chromatography mass spectrometry (GC/MS) to determine cathine (CAT), cathinone (CTN) and norephedrine (NE), jointly khatamines. In this study, khatamines' oximation, trimethylsilylation and mass fragmentation properties-applying N-Methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA), its trimethyliodosilane (TMIS) catalyst containing version (MSTFA(TMIS)), N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and hexamethyldisilazane (HMDS)-was highlighted, at first. Derivatization, mass fragmentation and quantitation related, optimized model investigations have been carried out as a function of the reaction times and conditions. Special emphasis was put (i) on the stability of the primarily formed (CAT-2TMS, NE-2TMS, CTN-TMS(TMS-oximes)1,2), then transformed, fully derived (CAT-3TMS, NE-3MTS, CTN-2TMS(TMS-oximes)1,2) species, and, (ii) on the proportionally formed stable products, suitable to selective quantitation of all three natural amines, simultaneously. Results, as novelty to the field confirmed that (i) TMIS catalyzed trimethylsilyation triggers to form fully derivatized species unfortunately, in part only; while, (ii) khatamines' simultaneous quantitation needs to be carried out in a two steps derivatization process consisting of oximation (1st step, hydroxylamine in pyridine) and trimethylsilylation (2nd step, MSTFA), to the CAT-2TMS, NE-2TMS, CTN-TMS(TMS-oximes)1,2. These species were characterized with their retention, mass fragmentation and analytical performance properties, in model solutions and in the presence of plant tissues, as well: R(2), limit of quantitation (LOQ) data, expressed in pg/1μL injection basis, proved to be 62.5pg (CAT), 20pg (NE) and 62.5pg (CTN), respectively. The practical utility of proposal was enormously enhanced by the novel, direct sample preparation method. In this process, the freshly harvested, freeze-dried, then pulverized leaves of Catha edulis FORKS were directly derivatized, in the presence of the matrix. Reproducibility (in average 2.07 RSD% varying between 0.15 and 5.5 RSD%), linearity (0.9990-0.9994) and recovery (95.7-99.1%) values of the new sample preparation protocol was confirmed by the standard addition method for CAT, NE and CTN equally. From plant leaf, 0.061w/w% CAT and 0.014w/w% NE contents were obtained. In this tissue CTN was not found. Very likely attributable to the unfavorable climate for the plant: grown in Hungary of temperate zone and naturalized in the tropical Africa. Copyright © 2016 Elsevier B.V. All rights reserved.

Transcranial magnetic stimulation in myoclonus of different aetiologies.

PubMed

Nardone, Raffaele; Versace, Viviana; Höller, Yvonne; Sebastianelli, Luca; Brigo, Francesco; Lochner, Piergiorgio; Golaszewski, Stefan; Saltuari, Leopold; Trinka, Eugen

2018-05-24

Transcranial magnetic stimulation (TMS) may represent a valuable tool for investigating important neurophysiological and pathophysiological aspects of myoclonus. Moreover, repetitive TMS (rTMS) can influence neural activity. In this review we performed a systematic search of all studies using TMS in order to explore cortical excitability/plasticity and rTMS for the treatment of myoclonus due to different aetiologies. We identified and reviewed 40 articles matching the inclusion criteria; 415 patients were included in these studies. The reviewed TMS studies have detected abnormalities in motor cortex excitability and sensorimotor plasticity. The most consistent finding is a decrease in intracortical inhibition. Short-interval intracortical inhibition (SICI) is reduced in myoclonic epilepsies. Unlike the juvenile and the benign myoclonus epilepsy, long-interval intracortical inhibition, interhemispheric inhibition and sensorimotor integration were altered in patients with progressive myoclonic epilepsies. In patients with myoclonus-dystonia the results are partly conflicting. Cortical membrane excitability was impaired while parameters assessing cortical synaptic activity were normal in DYT11 gene carriers. In other studies normal SICI suggests that the GABAergic cortical circuits are largely intact and that the mechanisms of myoclonus-dystonia are different from those for cortical myoclonus and other dystonic disorders. In conclusion, different TMS study protocols have provided new insights into sensorimotor plasticity and cortical excitability of the different forms of myoclonus, and have shed some light on the pathophysiology of this movement disorder. Well-defined motor cortical excitability patterns can be identified in the different disorders characterized by myoclonus, even if preliminary findings should be confirmed in future studies in larger cohorts of patients. Repetitive TMS might have therapeutic potential at least in some patients with myoclonus, similar to that reported in other neurological and psychiatric disorders. Copyright © 2018. Published by Elsevier Inc.

Effect of low-frequency rTMS on electromagnetic tomography (LORETA) and regional brain metabolism (PET) in schizophrenia patients with auditory hallucinations.

PubMed

Horacek, Jiri; Brunovsky, Martin; Novak, Tomas; Skrdlantova, Lucie; Klirova, Monika; Bubenikova-Valesova, Vera; Krajca, Vladimir; Tislerova, Barbora; Kopecek, Milan; Spaniel, Filip; Mohr, Pavel; Höschl, Cyril

2007-01-01

Auditory hallucinations are characteristic symptoms of schizophrenia with high clinical importance. It was repeatedly reported that low frequency (

Repeatability and reliability of muscle relaxation properties induced by motor cortical stimulation.

PubMed

Molenaar, Joery P; Voermans, Nicol C; de Jong, Lysanne A; Stegeman, Dick F; Doorduin, Jonne; van Engelen, Baziel G

2018-03-15

Impaired muscle relaxation is a feature of many neuromuscular disorders. However, there are few tests available to quantify muscle relaxation. Transcranial magnetic stimulation (TMS) of the motor cortex can induce muscle relaxation by abruptly inhibiting corticospinal drive. The aim of our study is to investigate if repeatability and reliability of TMS-induced relaxation is greater than voluntary relaxation. Furthermore, effects of sex, cooling and fatigue on muscle relaxation properties were studied. Muscle relaxation of deep finger flexors was assessed in twenty-five healthy subjects (14 M and 11 F, aged 39.1{plus minus}12.7 and 45.3{plus minus}8.7 years old, respectively) using handgrip dynamometry. All outcome measures showed greater repeatability and reliability in TMS-induced relaxation compared to voluntary relaxation. The within-subject coefficient of variability of normalized peak relaxation rate was lower in TMS-induced relaxation than in voluntary relaxation (3.0 vs 19.7% in men, and 6.1 vs 14.3% in women). The repeatability coefficient was lower (1.3 vs 6.1 s -1 in men and 2.3 vs 3.1 s -1 in women), and the intraclass correlation coefficient was higher (0.95 vs 0.53 in men and 0.78 vs 0.69 in women), for TMS-induced relaxation compared to voluntary relaxation. TMS enabled to demonstrate slowing effects of sex, muscle cooling, and muscle fatigue on relaxation properties that voluntary relaxation could not. In conclusion, repeatability and reliability of TMS-induced muscle relaxation was greater compared to voluntary muscle relaxation. TMS-induced muscle relaxation has the potential to be used in clinical practice for diagnostic purposes and therapy effect monitoring in patients with impaired muscle relaxation.

Safety and tolerability of repetitive transcranial magnetic stimulation in patients with pathologic positive sensory phenomena: a review of literature

PubMed Central

Muller, Paul A; Pascual-Leone, Alvaro; Rotenberg, Alexander

2013-01-01

BACKGROUND Repetitive transcranial magnetic stimulation (rTMS) is emerging as a valuable therapeutic and diagnostic tool. rTMS appears particularly promising for disorders characterized by positive sensory phenomena attributable to alterations in sensory cortex excitability. Among these are tinnitus, auditory and visual hallucinations, and pain syndromes. OBJECTIVE Despite studies addressing rTMS efficacy in suppression of positive sensory symptoms, the safety of stimulation of potentially hyperexcitable cortex has not been fully addressed. We performed a systematic literature review and metanalysis to describe the rTMS safety profile in these disorders. METHODS Using the PubMed database, we performed an English-language literature search from January 1985 to April 2011 to review all pertinent publications. Per study, we noted and listed pertinent details. From these data we also calculated a crude per-subject risk for each adverse event. RESULTS 106 publications (n = 1815 subjects) were identified with patients undergoing rTMS for pathologic positive sensory phenomena. Adverse events associated with rTMS were generally mild and occurred in 16.7% of subjects. Seizure was the most serious adverse event, and occurred in three patients with a 0.16% crude per-subject risk. The second most severe adverse event involved aggravation of sensory phenomena, occurring in 1.54%. CONCLUSIONS The published data suggest rTMS for the treatment or diagnosis of pathologic positive sensory phenomena appears to be a relatively safe and well-tolerated procedure. However, published data are lacking in systematic reporting of adverse events, and safety risks of rTMS in these patient populations will have to be addressed in future prospective trials. PMID:22322098

Transcranial magnetic stimulation (TMS) responses elicited in hindlimb muscles as an assessment of synaptic plasticity in spino-muscular circuitry after chronic spinal cord injury.

PubMed

Petrosyan, Hayk A; Alessi, Valentina; Sisto, Sue A; Kaufman, Mark; Arvanian, Victor L

2017-03-06

Electromagnetic stimulation applied at the cranial level, i.e. transcranial magnetic stimulation (TMS), is a technique for stimulation and neuromodulation used for diagnostic and therapeutic applications in clinical and research settings. Although recordings of TMS elicited motor-evoked potentials (MEP) are an essential diagnostic tool for spinal cord injured (SCI) patients, they are reliably recorded from arm, and not leg muscles. Mid-thoracic contusion is a common SCI that results in locomotor impairments predominantly in legs. In this study, we used a chronic T10 contusion SCI rat model and examined whether (i) TMS-responses in hindlimb muscles can be used for evaluation of conduction deficits in cortico-spinal circuitry and (ii) if plastic changes at spinal levels will affect these responses. In this study, plastic changes of transmission in damaged spinal cord were achieved by repetitive electro-magnetic stimulation applied over the spinal level (rSEMS). Spinal electro-magnetic stimulation was previously shown to activate spinal nerves and is gaining large acceptance as a non-invasive alternative to direct current and/or epidural electric stimulation. Results demonstrate that TMS fails to induce measurable MEPs in hindlimbs of chronically SCI animals. After facilitation of synaptic transmission in damaged spinal cord was achieved with rSEMS, however, MEPs were recorded from hindlimb muscles in response to single pulse TMS stimulation. These results provide additional evidence demonstrating beneficial effects of TMS as a diagnostic technique for descending motor pathways in uninjured CNS and after SCI. This study confirms the ability of TMS to assess plastic changes of transmission occurring at the spinal level. Published by Elsevier B.V.

The characteristic and changes of the event-related potentials (ERP) and brain topographic maps before and after treatment with rTMS in subjective tinnitus patients.

PubMed

Yang, Haidi; Xiong, Hao; Yu, Rongjun; Wang, Changming; Zheng, Yiqing; Zhang, Xueyuan

2013-01-01

To compare the event-related potentials (ERPs) and brain topographic maps characteristic and change in normal controls and subjective tinnitus patients before and after repetitive transcranial magnetic stimulation (rTMS) treatment. The ERPs and brain topographic maps elicited by target stimulus were compared before and after 1-week treatment with rTMS in 20 subjective tinnitus patients and 16 healthy controls. Before rTMS, target stimulus elicited a larger N1 component than the standard stimuli (repeating sounds)in control group but not in tinnitus patients. Instead, the tinnitus group pre-treatment exhibited larger amplitude of N1 in response to standard stimuli than to deviant stimuli. Furthermore tinnitus patients had smaller mismatch negativity (MMN) and late discriminative negativity (LDN)component at Fz compared with the control group. After rTMS treatment, tinnitus patients showed increased N1 response to deviant stimuli and larger MMN and LDN compared with pre-treatment. The topographic maps for the tinnitus group before rTMS -treatment demonstrated global asymmetry between the left and right cerebral hemispheres with more negative activities in left side and more positive activities in right side. In contrast, the brain topographic maps for patients after rTMS-treatment and controls seem roughly symmetrical. The ERP amplitudes and brain topographic maps in post-treatment patient group showed no significant difference with those in controls. The characterical changes in ERP and brain topographic maps in tinnitus patients maybe related with the electrophysiological mechanism of tinnitus induction and development. It can be used as an objective biomarker for the evaluation of auditory central in subjective tinnitus patients. These findings support the notion that rTMS treatment in tinnitus patients may exert a beneficial effect.

The Impact of Accelerated Right Prefrontal High-Frequency Repetitive Transcranial Magnetic Stimulation (rTMS) on Cue-Reactivity: An fMRI Study on Craving in Recently Detoxified Alcohol-Dependent Patients

PubMed Central

Herremans, Sarah C.; Van Schuerbeek, Peter; De Raedt, Rudi; Matthys, Frieda; Buyl, Ronald; De Mey, Johan; Baeken, Chris

2015-01-01

In alcohol-dependent patients craving is a difficult-to-treat phenomenon. It has been suggested that high-frequency (HF) repetitive transcranial magnetic stimulation (rTMS) may have beneficial effects. However, exactly how this application exerts its effect on the underlying craving neurocircuit is currently unclear. In an effort to induce alcohol craving and to maximize detection of HF-rTMS effects to cue-induced alcohol craving, patients were exposed to a block and event-related alcohol cue-reactivity paradigm while being scanned with fMRI. Hence, we assessed the effect of right dorsolateral prefrontal cortex (DLPFC) stimulation on cue-induced and general alcohol craving, and the related craving neurocircuit. Twenty-six recently detoxified alcohol-dependent patients were included. First, we evaluated the impact of one sham-controlled stimulation session. Second, we examined the effect of accelerated right DLPFC HF-rTMS treatment: here patients received 15 sessions in an open label accelerated design, spread over 4 consecutive days. General craving significantly decreased after 15 active HF-rTMS sessions. However, cue-induced alcohol craving was not altered. Our brain imaging results did not show that the cue-exposure affected the underlying craving neurocircuit after both one and fifteen active HF-rTMS sessions. Yet, brain activation changes after one and 15 HF-rTMS sessions, respectively, were observed in regions associated with the extended reward system and the default mode network, but only during the presentation of the event-related paradigm. Our findings indicate that accelerated HF-rTMS applied to the right DLPFC does not manifestly affect the craving neurocircuit during an alcohol-related cue-exposure, but instead it may influence the attentional network. PMID:26295336

Repetitive transcranial magnetic stimulation induced modulations of resting state motor connectivity in writer's cramp.

PubMed

Bharath, R D; Biswal, B B; Bhaskar, M V; Gohel, S; Jhunjhunwala, K; Panda, R; George, L; Gupta, A K; Pal, P K

2015-05-01

Writer's cramp (WC) is a focal task-specific dystonia of the hand which is increasingly being accepted as a network disorder. Non-invasive cortical stimulation using repetitive transcranial magnetic stimulation (rTMS) has produced therapeutic benefits in some of these patients. This study aimed to visualize the motor network abnormalities in WC and also its rTMS induced modulations using resting state functional magnetic resonance imaging (rsfMRI). Nineteen patients with right-sided WC and 20 matched healthy controls (HCs) were prospectively evaluated. All patients underwent a single session of rTMS and rsfMRI was acquired before (R1) and after (R2) rTMS. Seed-based functional connectivity analysis of several regions in the motor network was performed for HCs, R1 and R2 using SPM8 software. Thresholded (P < 0.05, false discovery rate corrected) group level mean correlation maps were used to derive significantly connected region of interest pairs. Writer's cramp showed a significant reduction in resting state functional connectivity in comparison with HCs involving the left cerebellum, thalamus, globus pallidus, putamen, bilateral supplementary motor area, right medial prefrontal lobe and right post central gyrus. After rTMS there was a significant increase in the contralateral resting state functional connectivity through the left thalamus-right globus pallidus-right thalamus-right prefrontal lobe network loop. It is concluded that WC is a network disorder with widespread dysfunction much larger than clinically evident and changes induced by rTMS probably act through subcortical and trans-hemispheric unaffected connections. Longitudinal studies with therapeutic rTMS will be required to ascertain whether such information could be used to select patients prior to rTMS therapy. © 2015 EAN.

Repetitive transcranial magnetic stimulation and transcranial direct-current stimulation in neuropathic pain due to radiculopathy: a randomized sham-controlled comparative study.

PubMed

Attal, Nadine; Ayache, Samar S; Ciampi De Andrade, Daniel; Mhalla, Alaa; Baudic, Sophie; Jazat, Frédérique; Ahdab, Rechdi; Neves, Danusa O; Sorel, Marc; Lefaucheur, Jean-Pascal; Bouhassira, Didier

2016-06-01

No study has directly compared the effectiveness of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS) in neuropathic pain (NP). In this 2-centre randomised double-blind sham-controlled study, we compared the efficacy of 10-Hz rTMS and anodal 2-mA tDCS of the motor cortex and sham stimulation contralateral to the painful area (3 daily sessions) in patients with NP due to lumbosacral radiculopathy. Average pain intensity (primary outcome) was evaluated after each session and 5 days later. Secondary outcomes included neuropathic symptoms and thermal pain thresholds for the upper limbs. We used an innovative design that minimised bias by randomly assigning patients to 1 of 2 groups: active rTMS and tDCS or sham rTMS and tDCS. For each treatment group (active or sham), the order of the sessions was again randomised according to a crossover design. In total, 51 patients were screened and 35 (51% women) were randomized. Active rTMS was superior to tDCS and sham in pain intensity (F = 2.89 and P = 0.023). Transcranial direct-current stimulation was not superior to sham, but its analgesic effects were correlated to that of rTMS (P = 0.046), suggesting common mechanisms of action. Repetitive transcranial magnetic stimulation lowered cold pain thresholds (P = 0.04) and its effect on cold pain was correlated with its analgesic efficacy (P = 0.006). However, rTMS had no impact on individual neuropathic symptoms. Thus, rTMS is more effective than tDCS and sham in patients with NP due to lumbosacral radiculopathy and may modulate the sensory and affective dimensions of pain.

Corrosion resistance improvement for 316L stainless steel coronary artery stents by trimethylsilane plasma nanocoatings

PubMed Central

Jones, John Eric; Chen, Meng; Yu, Qingsong

2015-01-01

To improve their corrosion resistance and thus long-term biocompatibility, 316L stainless steel coronary artery stents were coated with trimethylsilane (TMS) plasma coatings of 20–25 nm in thickness. Both direct current (DC) and radio-frequency (RF) glow discharges were utilized for TMS plasma coatings and additional NH3/O2 plasma treatment to tailor the surface properties. X-ray photoelectron spectroscopy (XPS) was used to characterize the coating surface chemistry. It was found that both DC and RF TMS plasma coatings had Si- and C-rich composition, and the O-and N-contents on the surfaces were substantially increased after NH3/O2 plasma treatment. Surface contact angle measurements showed that DC TMS plasma nanocoating with NH3/O2 plasma treatment generated very hydrophilic surface. The corrosion resistance of TMS plasma coated stents was evaluated through potentiodynamic polarization and electro-chemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization demonstrated that the TMS plasma coated stents imparted higher corrosion potential and pitting potential, as well as lower corrosion current densities as compared with uncoated controls. The surface morphology of stents before and after potentiodynamic polarization testing was analyzed with scanning electron microscopy, which indicated less corrosion on coated stents than uncoated controls. It was also noted that, from EIS data, the hydrophobic TMS plasma nanocoatings showed stable impedance modulus at 0.1 Hz after 21 day immersion in an electrolyte solution. These results suggest improved corrosion resistance of the 316L stainless steel stents by TMS plasma nanocoatings and great promise in reducing and blocking metallic ions releasing into the bloodstream. PMID:24500866

A high-resolution computational localization method for transcranial magnetic stimulation mapping.

PubMed

Aonuma, Shinta; Gomez-Tames, Jose; Laakso, Ilkka; Hirata, Akimasa; Takakura, Tomokazu; Tamura, Manabu; Muragaki, Yoshihiro

2018-05-15

Transcranial magnetic stimulation (TMS) is used for the mapping of brain motor functions. The complexity of the brain deters determining the exact localization of the stimulation site using simplified methods (e.g., the region below the center of the TMS coil) or conventional computational approaches. This study aimed to present a high-precision localization method for a specific motor area by synthesizing computed non-uniform current distributions in the brain for multiple sessions of TMS. Peritumoral mapping by TMS was conducted on patients who had intra-axial brain neoplasms located within or close to the motor speech area. The electric field induced by TMS was computed using realistic head models constructed from magnetic resonance images of patients. A post-processing method was implemented to determine a TMS hotspot by combining the computed electric fields for the coil orientations and positions that delivered high motor-evoked potentials during peritumoral mapping. The method was compared to the stimulation site localized via intraoperative direct brain stimulation and navigated TMS. Four main results were obtained: 1) the dependence of the computed hotspot area on the number of peritumoral measurements was evaluated; 2) the estimated localization of the hand motor area in eight non-affected hemispheres was in good agreement with the position of a so-called "hand-knob"; 3) the estimated hotspot areas were not sensitive to variations in tissue conductivity; and 4) the hand motor areas estimated by this proposal and direct electric stimulation (DES) were in good agreement in the ipsilateral hemisphere of four glioma patients. The TMS localization method was validated by well-known positions of the "hand-knob" in brains for the non-affected hemisphere, and by a hotspot localized via DES during awake craniotomy for the tumor-containing hemisphere. Copyright © 2018 Elsevier Inc. All rights reserved.

Repetitive transcranial magnetic stimulation of the right parietal cortex for comorbid generalized anxiety disorder and insomnia: A randomized, double-blind, sham-controlled pilot study.

PubMed

Huang, Zhaoyang; Li, Yue; Bianchi, Matt T; Zhan, Shuqin; Jiang, Fengying; Li, Ning; Ding, Yan; Hou, Yue; Wang, Li; Ouyang, Quping; Wang, Yuping

2018-05-29

Repetitive transcranial magnetic stimulation (rTMS) has been considered to be a promising technique for the treatment of neuropsychiatric disorders. However, little is known about the effectiveness of rTMS in the treatment of generalized anxiety disorder (GAD). Moreover, treatment data on comorbid GAD and insomnia remain lacking. The aim of this study was to examine the therapeutic effects of 1 Hz rTMS applied over the right parietal lobe on both anxiety and insomnia symptoms in patients with comorbid GAD and insomnia. 36 patients were randomized to either sham or active rTMS group (n = 18 each group). The rTMS was administered over the right posterior parietal cortex (P4 electrode site) at a frequency of 1 Hz and an intensity of 90% of the resting motor threshold. Ten days of 1 Hz rTMS to the right parietal lobe significantly improved both anxiety and insomnia symptoms in the active group. Although the anxiety severity was not significantly correlated with insomnia severity at baseline, the improvement in the Hamilton Rating Scale for Anxiety (HRSA) scores were positively correlated with improvement in the Pittsburgh Sleep Quality Index (PSQI) scores. The present study is the first randomized sham-controlled study to assess the effectiveness of low frequency rTMS on the right parietal lobe in patients with comorbid GAD and insomnia. Our results suggested that 1 Hz low frequency rTMS administered over the parietal cortex is effective for both anxiety and insomnia symptoms in patients with comorbid GAD and insomnia. Copyright © 2018 Elsevier Inc. All rights reserved.

Effectiveness of theta-burst repetitive transcranial magnetic stimulation for treating chronic tinnitus.

PubMed

Chung, Hsiung-Kwang; Tsai, Chon-Haw; Lin, Yu-Chin; Chen, Jin-Ming; Tsou, Yung-An; Wang, Chin-Yuan; Lin, Chia-Der; Jeng, Fuh-Cherng; Chung, Jing-Gung; Tsai, Ming-Hsui

2012-01-01

Repetitive transcranial magnetic stimulation (rTMS), a noninvasive method for altering cortical excitability, is becoming a therapeutic strategy in auditory research institutions worldwide. Application of inhibiting rTMS on these overactive cortical regions can result in effective tinnitus suppression. The aim of this study is to investigate the efficacy of theta-burst rTMS in patients with chronic tinnitus. Parallel randomized control study. Tertiary referral center. We enrolled 2 female and 20 male patients in this study. The evaluative tools included tinnitus frequency- and loudness-matching, tinnitus questionnaires (TQ), and the Tinnitus Handicap Inventory (THI). The orthogonal projection of the auditory cortex on the scalp was focalized. A figure-eight coil was placed on the surface of the skull over the targeted region with the intensity setting at 80% of the resting motor threshold. We delivered 900 pulses of theta-burst rTMS daily for 10 business days. Nine of twelve patients (75%) in the active-stimulation group reported tinnitus suppression following treatment with rTMS. The treatment led to reductions of 8.58 and 8.33 in the mean TQ global and THI scores, respectively. Tinnitus loudness also decreased significantly after delivering rTMS. Descriptive analysis of the TQs revealed that patients experienced significant improvements in emotional distress levels and somatic symptoms. Our preliminary results demonstrate that theta-burst rTMS treatments offer a method of modulating tinnitus. Patients could benefit from emotional improvements, even more than auditory perceptive relief. Further studies are needed to establish a standard protocol and to clarify nervous propagation along the auditory and psychological projection following treatment with rTMS. Copyright © 2011 S. Karger AG, Basel.

Role of Brain-Derived Neurotrophic Factor in Beneficial Effects of Repetitive Transcranial Magnetic Stimulation for Upper Limb Hemiparesis after Stroke.

PubMed

Niimi, Masachika; Hashimoto, Kenji; Kakuda, Wataru; Miyano, Satoshi; Momosaki, Ryo; Ishima, Tamaki; Abo, Masahiro

2016-01-01

Repetitive transcranial magnetic stimulation (rTMS) can improve upper limb hemiparesis after stroke but the mechanism underlying its efficacy remains elusive. rTMS seems to alter brain-derived neurotrophic factor (BDNF) and such effect is influenced by BDNF gene polymorphism. To investigate the molecular effects of rTMS on serum levels of BDNF, its precursor proBDNF and matrix metalloproteinase-9 (MMP-9) in poststroke patients with upper limb hemiparesis. Poststroke patients with upper limb hemiparesis were studied. Sixty-two patients underwent rehabilitation plus rTMS combination therapy and 33 patients underwent rehabilitation monotherapy without rTMS for 14 days at our hospital. One Hz rTMS was applied over the motor representation of the first dorsal interosseous muscle on the non-lesional hemisphere. Fugl-Meyer Assessment and Wolf Motor Function (WMFT) were used to evaluate motor function on the affected upper limb before and after intervention. Blood samples were collected for analysis of BDNF polymorphism and measurement of BDNF, proBDNF and MMP-9 levels. Two-week combination therapy increased BDNF and MMP-9 serum levels, but not serum proBDNF. Serum BDNF and MMP-9 levels did not correlate with motor function improvement, though baseline serum proBDNF levels correlated negatively and significantly with improvement in WMFT (ρ = -0.422, p = 0.002). The outcome of rTMS therapy was not altered by BDNF gene polymorphism. The combination therapy of rehabilitation plus low-frequency rTMS seems to improve motor function in the affected limb, by activating BDNF processing. BDNF and its precursor proBDNF could be potentially suitable biomarkers for poststroke motor recovery.

From pulses to pain relief: an update on the mechanisms of rTMS-induced analgesic effects.

PubMed

Moisset, X; de Andrade, D C; Bouhassira, D

2016-05-01

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive technique that allows cortical stimulation. Recent studies have shown that rTMS of the primary motor cortex or dorsolateral prefrontal cortex decreases pain in various pain conditions. The aim of this review was to summarize the main characteristics of rTMS-induced analgesic effects and to analyse the current data on its mechanisms of action. Medline, PubMed and Web of Science were searched for studies on the analgesic effects and mechanisms of rTMS-induced analgesic effects. Studies on epidural motor cortex stimulation (EMCS) were also included when required, as several mechanisms of action are probably shared between both techniques. Stimulation site and stimulation parameters have a major impact on rTMS-related analgesic effects. Local cortical stimulation is able to elicit changes in the functioning of distant brain areas. These modifications outlast the duration of the rTMS session and probably involve LTP-like mechanisms via its influence on glutamatergic networks. Analgesic effects seem to be correlated to restoration of normal cortical excitability in chronic pain patients and depend on pain modulatory systems, in particular endogenous opioids. Dopamine, serotonin, norepinephrine and GABAergic circuitry may also be involved in its effects, as well as rostrocaudal projections. rTMS activates brain areas distant from the stimulation site. LTP-like mechanisms, dependence on endogenous opioids and increase in concentration of neurotransmitters (monoamines, GABA) have all been implicated in its analgesic effects, although more studies are needed to fill in the still existing gaps in the understanding of its mechanisms of action. © 2015 European Pain Federation - EFIC®

sEMG Sensor Using Polypyrrole-Coated Nonwoven Fabric Sheet for Practical Control of Prosthetic Hand

PubMed Central

Jiang, Yinlai; Togane, Masami; Lu, Baoliang; Yokoi, Hiroshi

2017-01-01

One of the greatest challenges of using a myoelectric prosthetic hand in daily life is to conveniently measure stable myoelectric signals. This study proposes a novel surface electromyography (sEMG) sensor using polypyrrole-coated nonwoven fabric sheet as electrodes (PPy electrodes) to allow people with disabilities to control prosthetic limbs. The PPy electrodes are sewn on an elastic band to guarantee close contact with the skin and thus reduce the contact electrical impedance between the electrodes and the skin. The sensor is highly customizable to fit the size and the shape of the stump so that people with disabilities can attach the sensor by themselves. The performance of the proposed sensor was investigated experimentally by comparing measurements of Ag/AgCl electrodes with electrolytic gel and the sEMG from the same muscle fibers. The high correlation coefficient (0.87) between the two types of sensors suggests the effectiveness of the proposed sensor. Another experiment of sEMG pattern recognition to control myoelectric prosthetic hands showed that the PPy electrodes are as effective as Ag/AgCl electrodes for measuring sEMG signals for practical myoelectric control. We also investigated the relation between the myoelectric signals' signal-to-noise ratio and the source impedances by simultaneously measuring the source impedances and the myoelectric signals with a switching circuit. The results showed that differences in both the norm and the phase of the source impedance greatly affect the common mode noise in the signal. PMID:28220058

Transient suppression of seizures by repetitive transcranial magnetic stimulation in a case of Rasmussen's encephalitis.

PubMed

Rotenberg, Alexander; Depositario-Cabacar, Dewi; Bae, Erica Hyunji; Harini, Chellamani; Pascual-Leone, Alvaro; Takeoka, Masanori

2008-07-01

Repetitive transcranial magnetic stimulation (rTMS) has been applied with variable success to terminate the seizures of epilepsia partialis continua. The rationale for using this technique to suppress ongoing seizures is the capacity of rTMS to interrupt ongoing neuronal activity, and to produce a lasting decrease in cortical excitability with low-frequency (1 Hz) stimulation. We report a case of epilepsia partialis continua in a child with Rasmussen's encephalitis, in whom seizures were transiently suppressed by 1-Hz rTMS delivered in nine daily 30-minute sessions. In this case, total ictal time was significantly reduced during stimulation, but the daily baseline seizure rate remained unchanged. Notably, the detection and quantification of this short-lived improvement were enabled by recording EEG continuously during the rTMS session. Thus, we present this case to illustrate a potential utility of combined continuous EEG recording and rTMS in seizure treatment.

Effects of low frequency repetitive transcranial magnetic stimulation (rTMS) on gamma frequency oscillations and event-related potentials during processing of illusory figures in autism.

PubMed

Sokhadze, Estate M; El-Baz, Ayman; Baruth, Joshua; Mathai, Grace; Sears, Lonnie; Casanova, Manuel F

2009-04-01

Previous studies by our group suggest that the neuropathology of autism is characterized by a disturbance of cortical modularity. In this model a decrease in the peripheral neuropil space of affected minicolumns provides for an inhibitory deficit and a readjustment in their signal to noise bias during information processing. In this study we proposed using low frequency transcranial magnetic stimulation (rTMS) as a way increasing the surround inhibition of minicolumns in autism. Thirteen patients (ADOS and ADI-R diagnosed) and equal number of controls participated in the study. Repetitive TMS was delivered at 0.5 Hz, 2 times per week for 3 weeks. Outcome measures based on event-related potentials (ERP), induced gamma activity, and behavioral measures showed significant post-TMS improvement. The results suggest that rTMS offers a potential therapeutic intervention for autism.

Transcranial Magnetic Stimulation in Child Neurology: Current and Future Directions

PubMed Central

Frye, Richard E.; Rotenberg, Alexander; Ousley, Molliann; Pascual-Leone, Alvaro

2008-01-01

Transcranial magnetic stimulation (TMS) is a method for focal brain stimulation based on the principle of electromagnetic induction, where small intracranial electric currents are generated by a powerful, rapidly changing extracranial magnetic field. Over the past 2 decades TMS has shown promise in the diagnosis, monitoring, and treatment of neurological and psychiatric disease in adults, but has been used on a more limited basis in children. We reviewed the literature to identify potential diagnostic and therapeutic applications of TMS in child neurology and also its safety in pediatrics. Although TMS has not been associated with any serious side effects in children and appears to be well tolerated, general safety guidelines should be established. The potential for applications of TMS in child neurology and psychiatry is significant. Given its excellent safety profile and possible therapeutic effect, this technique should develop as an important tool in pediatric neurology over the next decade. PMID:18056688

Simultaneous transcranial magnetic stimulation and single neuron recording in alert non-human primates

PubMed Central

Mueller, Jerel K.; Grigsby, Erinn M.; Prevosto, Vincent; Petraglia, Frank W.; Rao, Hrishikesh; Deng, Zhi-De; Peterchev, Angel V.; Sommer, Marc A.; Egner, Tobias; Platt, Michael L.; Grill, Warren M.

2014-01-01

Transcranial magnetic stimulation (TMS) is a widely used, noninvasive method for stimulating nervous tissue, yet its mechanisms of effect are poorly understood. Here we report novel methods for studying the influence of TMS on single neurons in the brain of alert non-human primates. We designed a TMS coil that focuses its effect near the tip of a recording electrode and recording electronics that enable direct acquisition of neuronal signals at the site of peak stimulus strength minimally perturbed by stimulation artifact in intact, awake monkeys (Macaca mulatta). We recorded action potentials within ~1 ms after 0.4 ms TMS pulses and observed changes in activity that differed significantly for active stimulation as compared to sham stimulation. The methodology is compatible with standard equipment in primate laboratories, allowing for easy implementation. Application of these new tools will facilitate the refinement of next generation TMS devices, experiments, and treatment protocols. PMID:24974797

Experimental Method for Characterizing Electrical Steel Sheets in the Normal Direction

PubMed Central

Hihat, Nabil; Lecointe, Jean Philippe; Duchesne, Stephane; Napieralska, Ewa; Belgrand, Thierry

2010-01-01

This paper proposes an experimental method to characterise magnetic laminations in the direction normal to the sheet plane. The principle, which is based on a static excitation to avoid planar eddy currents, is explained and specific test benches are proposed. Measurements of the flux density are made with a sensor moving in and out of an air-gap. A simple analytical model is derived in order to determine the permeability in the normal direction. The experimental results for grain oriented steel sheets are presented and a comparison is provided with values obtained from literature. PMID:22163394

TMS Suppression of Right Pars Triangularis, but Not Pars Opercularis, Improves Naming in Aphasia

ERIC Educational Resources Information Center

Naeser, Margaret A.; Martin, Paula I.; Theoret, Hugo; Kobayashi, Masahito; Fregni, Felipe; Nicholas, Marjorie; Tormos, Jose M.; Steven, Megan S.; Baker, Errol H.; Pascual-Leone, Alvaro

2011-01-01

This study sought to discover if an optimum 1 cm[squared] area in the non-damaged right hemisphere (RH) was present, which could temporarily improve naming in chronic, nonfluent aphasia patients when suppressed with repetitive transcranial magnetic stimulation (rTMS). Ten minutes of slow, 1 Hz rTMS was applied to suppress different RH ROIs in…

Combining Functional Neuroimaging with Off-Line Brain Stimulation: Modulation of Task-Related Activity in Language Areas

ERIC Educational Resources Information Center

Andoh, Jamila; Paus, Tomas

2011-01-01

Repetitive TMS (rTMS) provides a noninvasive tool for modulating neural activity in the human brain. In healthy participants, rTMS applied over the language-related areas in the left hemisphere, including the left posterior temporal area of Wernicke (LTMP) and inferior frontal area of Broca, have been shown to affect performance on word…

A comparison of the usefulness of canonical analysis, principal components analysis, and band selection for extraction of features from TMS data for landcover analysis

NASA Technical Reports Server (NTRS)

Boyd, R. K.; Brumfield, J. O.; Campbell, W. J.

1984-01-01

Three feature extraction methods, canonical analysis (CA), principal component analysis (PCA), and band selection, have been applied to Thematic Mapper Simulator (TMS) data in order to evaluate the relative performance of the methods. The results obtained show that CA is capable of providing a transformation of TMS data which leads to better classification results than provided by all seven bands, by PCA, or by band selection. A second conclusion drawn from the study is that TMS bands 2, 3, 4, and 7 (thermal) are most important for landcover classification.

Conditioned place avoidance of zebrafish (Danio rerio) to three chemicals used for euthanasia and anaesthesia.

PubMed

Wong, Devina; von Keyserlingk, Marina A G; Richards, Jeffrey G; Weary, Daniel M

2014-01-01

Zebrafish are becoming one of the most used vertebrates in developmental and biomedical research. Fish are commonly killed at the end of an experiment with an overdose of tricaine methanesulfonate (TMS, also known as MS-222), but to date little research has assessed if exposure to this or other agents qualifies as euthanasia (i.e. a "good death"). Alternative agents include metomidate hydrochloride and clove oil. We use a conditioned place avoidance paradigm to compare aversion to TMS, clove oil, and metomidate hydrochloride. Zebrafish (n = 51) were exposed to the different anaesthetics in the initially preferred side of a light/dark box. After exposure to TMS zebrafish spent less time in their previously preferred side; aversion was less pronounced following exposure to metomidate hydrochloride and clove oil. Nine of 17 fish exposed to TMS chose not to re-enter the previously preferred side, versus 2 of 18 and 3 of 16 refusals for metomidate hydrochloride and clove oil, respectively. We conclude that metomidate hydrochloride and clove oil are less aversive than TMS and that these agents be used as humane alternatives to TMS for killing zebrafish.

A Lack of Clinical Effect of High-frequency rTMS to Dorsolateral Prefrontal Cortex on Bulimic Symptoms: A Randomised, Double-blind Trial.

PubMed

Gay, Aurelia; Jaussent, Isabelle; Sigaud, Torrance; Billard, Stephane; Attal, Jerome; Seneque, Maude; Galusca, Bogdan; Van Den Eynde, Frederique; Massoubre, Catherine; Courtet, Philippe; Guillaume, Sebastien

2016-11-01

Studies suggest that stimulation of the left dorsolateral prefrontal cortex (DLPFC) reduces food craving in bulimic patients, but evidence supporting repetitive transcranial magnetic stimulation (rTMS) as a therapeutic tool is lacking. We investigated the safety and therapeutic efficacy of an adjunct high-frequency rTMS programme targeting the left DLPFC. Forty-seven women with bulimia nervosa were randomised to a real or sham stimulation group. The real group underwent 10 rTMS sessions, each consisting of 20 trains of 5 seconds with 55-second intervals between trains, at a frequency of 10 Hz. The main outcome was the number of binge episodes in the 15 days following the end of stimulation. Overall, no significant improvement in bingeing and purging symptoms was noted after the programme. rTMS was well tolerated. This suggests that 10 sessions of high-frequency rTMS to the left DLPFC provide no greater benefit than placebo. Future studies should consider methodological issues as well as alternative targets. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

An abundant tissue macrophage population in the adult murine heart with a distinct alternatively-activated macrophage profile.

PubMed

Pinto, Alexander R; Paolicelli, Rosa; Salimova, Ekaterina; Gospocic, Janko; Slonimsky, Esfir; Bilbao-Cortes, Daniel; Godwin, James W; Rosenthal, Nadia A

2012-01-01

Cardiac tissue macrophages (cTMs) are a previously uncharacterised cell type that we have identified and characterise here as an abundant GFP(+) population within the adult Cx(3)cr1(GFP/+) knock-in mouse heart. They comprise the predominant myeloid cell population in the myocardium, and are found throughout myocardial interstitial spaces interacting directly with capillary endothelial cells and cardiomyocytes. Flow cytometry-based immunophenotyping shows that cTMs exhibit canonical macrophage markers. Gene expression analysis shows that cTMs (CD45(+)CD11b(+)GFP(+)) are distinct from mononuclear CD45(+)CD11b(+)GFP(+) cells sorted from the spleen and brain of adult Cx(3)cr1(GFP/+) mice. Gene expression profiling reveals that cTMs closely resemble alternatively-activated anti-inflammatory M2 macrophages, expressing a number of M2 markers, including Mrc1, CD163, and Lyve-1. While cTMs perform normal tissue macrophage homeostatic functions, they also exhibit a distinct phenotype, involving secretion of salutary factors (including IGF-1) and immune modulation. In summary, the characterisation of cTMs at the cellular and molecular level defines a potentially important role for these cells in cardiac homeostasis.

A TMS Investigation on the Role of Lateral Occipital Complex and Caudal Intraparietal Sulcus in the Perception of Object Form and Orientation.

PubMed

Chouinard, Philippe A; Meena, Deiter K; Whitwell, Robert L; Hilchey, Matthew D; Goodale, Melvyn A

2017-05-01

We used TMS to assess the causal roles of the lateral occipital (LO) and caudal intraparietal sulcus (cIPS) areas in the perceptual discrimination of object features. All participants underwent fMRI to localize these areas using a protocol in which they passively viewed images of objects that varied in both form and orientation. fMRI identified six significant brain regions: LO, cIPS, and the fusiform gyrus, bilaterally. In a separate experimental session, we applied TMS to LO or cIPS while the same participants performed match-to-sample form or orientation discrimination tasks. Compared with sham stimulation, TMS to either the left or right LO increased RTs for form but not orientation discrimination, supporting a critical role for LO in form processing for perception- and judgment-based tasks. In contrast, we did not observe any effects when we applied TMS to cIPS. Thus, despite the clear functional evidence of engagement for both LO and cIPS during the passive viewing of objects in the fMRI experiment, the TMS experiment revealed that cIPS is not critical for making perceptual judgments about their form or orientation.

Reduction hybrid artifacts of EMG-EOG in electroencephalography evoked by prefrontal transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Bai, Yang; Wan, Xiaohong; Zeng, Ke; Ni, Yinmei; Qiu, Lirong; Li, Xiaoli

2016-12-01

Objective. When prefrontal-transcranial magnetic stimulation (p-TMS) performed, it may evoke hybrid artifact mixed with muscle activity and blink activity in EEG recordings. Reducing this kind of hybrid artifact challenges the traditional preprocessing methods. We aim to explore method for the p-TMS evoked hybrid artifact removal. Approach. We propose a novel method used as independent component analysis (ICA) post processing to reduce the p-TMS evoked hybrid artifact. Ensemble empirical mode decomposition (EEMD) was used to decompose signal into multi-components, then the components were separated with artifact reduced by blind source separation (BSS) method. Three standard BSS methods, ICA, independent vector analysis, and canonical correlation analysis (CCA) were tested. Main results. Synthetic results showed that EEMD-CCA outperformed others as ICA post processing step in hybrid artifacts reduction. Its superiority was clearer when signal to noise ratio (SNR) was lower. In application to real experiment, SNR can be significantly increased and the p-TMS evoked potential could be recovered from hybrid artifact contaminated signal. Our proposed method can effectively reduce the p-TMS evoked hybrid artifacts. Significance. Our proposed method may facilitate future prefrontal TMS-EEG researches.

Electrophysiological evidence of cerebellar fiber system involvement in the Miller Fisher syndrome.

PubMed

Lo, Y L; Fook-Chong, S; Chan, L L; Ong, W Y; Ratnagopal, P

2010-01-15

In the Miller Fisher syndrome (MFS), ataxia may be due involvement of Ia afferents and the cerebellum. Transcranial magnetic stimulation (TMS) over the cerebellum is known to interfere transiently with normal function. In this study, we utilized a previously described TMS protocol over the cerebellum in combination with ballistic movements to investigate cerebellar dysfunction in MFS patients. The agonist (biceps) reaction time in MFS patients during a motor cancellation task was not significantly reduced during the initial TMS study. However, during the repeat TMS study, significant reduction was seen for all patients, in tandem with clinical recovery. There was significant correlation between anti-GQ1b IgG titers and change in agonist reaction time between the initial and repeat TMS studies. TMS likely affected horizontally orientated parallel fibers in the cerebellar molecular layer. During disease onset, antibody binding may have interfered with facilitation of reaction time during motor cancellation tasks seen in normal subjects. Normalization of reaction time facilitation corresponded to resolution of antibody-mediated interference in the molecular layer. Our study has provided evidence suggesting parallel fiber involvement in MFS, and suggested a role of anti-GQ1b IgG antibody in these changes.

Effects of lacosamide and carbamazepine on human motor cortex excitability: a double-blind, placebo-controlled transcranial magnetic stimulation study.

PubMed

Lang, Nicolas; Rothkegel, Holger; Peckolt, Hannes; Deuschl, Günther

2013-11-01

Lacosamide (LCM) and carbamazepine (CBZ) are antiepileptic drugs both acting on neuronal voltage-gated sodium channels. Patch-clamp studies demonstrated significant differences in how LCM and CBZ affect neuronal membrane excitability. Despite valuable information patch-clamp studies provide, they also comprise some constraints. For example, little is known about effects of LCM on intracortical synaptic excitability. In contrast, transcranial magnetic stimulation (TMS) can describe drug-induced changes at the system level of the human cerebral cortex. The present study was designed to explore dose-depended effects of LCM and effects of CBZ on motor cortex excitability with TMS in a randomized, double-blind, placebo-controlled crossover trial in healthy human subjects. Subjects received 600 mg CBZ, 200 mg LCM, 400 mg LCM or placebo preceding TMS measurements. Compared to placebo, TMS motor thresholds were significantly increased after carbamazepine and lacosamide, with a trend for a dose dependent effect of lacosamide. Both, carbamazepine and lacosamide did not affect TMS parameters of intracortical synaptic excitability. TMS measurements suggest that lacosamide and carbamazepine predominantly act on neuronal membrane excitability. Copyright © 2013 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

TMS to object cortex affects both object and scene remote networks while TMS to scene cortex only affects scene networks.

PubMed

Rafique, Sara A; Solomon-Harris, Lily M; Steeves, Jennifer K E

2015-12-01

Viewing the world involves many computations across a great number of regions of the brain, all the while appearing seamless and effortless. We sought to determine the connectivity of object and scene processing regions of cortex through the influence of transient focal neural noise in discrete nodes within these networks. We consecutively paired repetitive transcranial magnetic stimulation (rTMS) with functional magnetic resonance-adaptation (fMR-A) to measure the effect of rTMS on functional response properties at the stimulation site and in remote regions. In separate sessions, rTMS was applied to the object preferential lateral occipital region (LO) and scene preferential transverse occipital sulcus (TOS). Pre- and post-stimulation responses were compared using fMR-A. In addition to modulating BOLD signal at the stimulation site, TMS affected remote regions revealing inter and intrahemispheric connections between LO, TOS, and the posterior parahippocampal place area (PPA). Moreover, we show remote effects from object preferential LO to outside the ventral perception network, in parietal and frontal areas, indicating an interaction of dorsal and ventral streams and possibly a shared common framework of perception and action. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transcranial magnetic stimulation: language function.

PubMed

Epstein, C M

1998-07-01

Studies of language using transcranial magnetic stimulation (TMS) have focused both on identification of language areas and on elucidation of function. TMS may result in either inhibition or facilitation of language processes and may operate directly at a presumptive site of language cortex or indirectly through intracortical networks. TMS has been used to create reversible "temporary lesions," similar to those produced by Wada tests and direct cortical electrical stimulation, in cerebral cortical areas subserving language function. Rapid-rate TMS over the left inferior frontal region blocks speech output in most subjects. However, the results are not those predicted from classic models of language organization. Speech arrest is obtained most easily over facial motor cortex, and true aphasia is rare, whereas right hemisphere or bilateral lateralization is unexpectedly prominent. A clinical role for these techniques is not yet fully established. Interfering with language comprehension and verbal memory is currently more difficult than blocking speech output, but numerous TMS studies have demonstrated facilitation of language-related tasks, including oral word association, story recall, digit span, and picture naming. Conversely, speech output also facilitates motor responses to TMS in the dominant hemisphere. Such new and often-unexpected findings may provide important insights into the organization of language.

More female patients and fewer stimuli per session are associated with the short-term antidepressant properties of repetitive transcranial magnetic stimulation (rTMS): a meta-analysis of 54 sham-controlled studies published between 1997–2013

PubMed Central

Kedzior, Karina Karolina; Azorina, Valeriya; Reitz, Sarah Kim

2014-01-01

Background Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) appears to have short-term antidepressant properties. The aim of the current study was to update our previous meta-analysis and to investigate factors associated with the antidepressant properties of rTMS. Method Following a systematic literature search conducted in Medline and PsycInfo, N=14 sham-controlled, parallel design studies (published after 2008 to August 2013) that had utilized rTMS of the DLPFC in major depression were included in the current meta-analysis. The sensitivity and moderator analyses also included data from N=40 studies (published in 1997–2008) from our previous meta-analysis. The effect size (Cohen’s d) in each study was the standardized difference in mean depression scores (on Hamilton Depression Rating Scale, Beck Depression Inventory, Montgomery Åsberg Depression Rating Scale) from baseline to final (after last session) in rTMS compared to sham groups. Results According to a random-effects model with inverse-variance weights, depression scores were significantly reduced after rTMS compared to sham in studies published from 2008–2013 based on N=659 patients (overall mean weighted d=−0.42, 95% confidence interval: −0.66, −0.18, P=0.001). Combining studies from our past and current meta-analyses (published in 1997–2013; N=54) revealed that depression was significantly reduced after left-fast (>1 Hz), right-slow (≤1 Hz), and bilateral (or sequential) rTMS of DLPFC compared to sham. Significant antidepressant properties of rTMS were observed in studies with patients who were treatment resistant, unipolar (or bipolar), non-psychotic, medication-free (or started on antidepressants concurrently with rTMS). According to univariate meta-regressions, depression scores were significantly lower in studies with more female patients and fewer stimuli per session. There was little evidence that publication bias occurred in the analysis. Conclusion According to this study, the largest meta-analysis to date, short-term antidepressant properties of rTMS are independent of concurrent antidepressants and might depend on sex and the number of stimuli per session. PMID:24855360

Maximal Voluntary Activation of the Elbow Flexors Is under Predicted by Transcranial Magnetic Stimulation Compared to Motor Point Stimulation Prior to and Following Muscle Fatigue

PubMed Central

Cadigan, Edward W. J.; Collins, Brandon W.; Philpott, Devin T. G.; Kippenhuck, Garreth; Brenton, Mitchell; Button, Duane C.

2017-01-01

Transcranial magnetic (TMS) and motor point stimulation have been used to determine voluntary activation (VA). However, very few studies have directly compared the two stimulation techniques for assessing VA of the elbow flexors. The purpose of this study was to compare TMS and motor point stimulation for assessing VA in non-fatigued and fatigued elbow flexors. Participants performed a fatigue protocol that included twelve, 15 s isometric elbow flexor contractions. Participants completed a set of isometric elbow flexion contractions at 100, 75, 50, and 25% of maximum voluntary contraction (MVC) prior to and following fatigue contractions 3, 6, 9, and 12 and 5 and 10 min post-fatigue. Force and EMG of the bicep and triceps brachii were measured for each contraction. Force responses to TMS and motor point stimulation and EMG responses to TMS (motor evoked potentials, MEPs) and Erb's point stimulation (maximal M-waves, Mmax) were also recorded. VA was estimated using the equation: VA% = (1−SITforce/PTforce) × 100. The resting twitch was measured directly for motor point stimulation and estimated for both motor point stimulation and TMS by extrapolation of the linear regression between the superimposed twitch force and voluntary force. MVC force, potentiated twitch force and VA significantly (p < 0.05) decreased throughout the elbow flexor fatigue protocol and partially recovered 10 min post fatigue. VA was significantly (p < 0.05) underestimated when using TMS compared to motor point stimulation in non-fatigued and fatigued elbow flexors. Motor point stimulation compared to TMS superimposed twitch forces were significantly (p < 0.05) higher at 50% MVC but similar at 75 and 100% MVC. The linear relationship between TMS superimposed twitch force and voluntary force significantly (p < 0.05) decreased with fatigue. There was no change in triceps/biceps electromyography, biceps/triceps MEP amplitudes, or bicep MEP amplitudes throughout the fatigue protocol at 100% MVC. In conclusion, motor point stimulation as opposed to TMS led to a higher estimation of VA in non-fatigued and fatigued elbow flexors. The decreased linear relationship between TMS superimposed twitch force and voluntary force led to an underestimation of the estimated resting twitch force and thus, a reduced VA. PMID:28979211

Maximal Voluntary Activation of the Elbow Flexors Is under Predicted by Transcranial Magnetic Stimulation Compared to Motor Point Stimulation Prior to and Following Muscle Fatigue.

PubMed

Cadigan, Edward W J; Collins, Brandon W; Philpott, Devin T G; Kippenhuck, Garreth; Brenton, Mitchell; Button, Duane C

2017-01-01

Transcranial magnetic (TMS) and motor point stimulation have been used to determine voluntary activation (VA). However, very few studies have directly compared the two stimulation techniques for assessing VA of the elbow flexors. The purpose of this study was to compare TMS and motor point stimulation for assessing VA in non-fatigued and fatigued elbow flexors. Participants performed a fatigue protocol that included twelve, 15 s isometric elbow flexor contractions. Participants completed a set of isometric elbow flexion contractions at 100, 75, 50, and 25% of maximum voluntary contraction (MVC) prior to and following fatigue contractions 3, 6, 9, and 12 and 5 and 10 min post-fatigue. Force and EMG of the bicep and triceps brachii were measured for each contraction. Force responses to TMS and motor point stimulation and EMG responses to TMS (motor evoked potentials, MEPs) and Erb's point stimulation (maximal M-waves, M max ) were also recorded. VA was estimated using the equation: VA% = (1- SITforce / PTforce ) × 100. The resting twitch was measured directly for motor point stimulation and estimated for both motor point stimulation and TMS by extrapolation of the linear regression between the superimposed twitch force and voluntary force. MVC force, potentiated twitch force and VA significantly ( p < 0.05) decreased throughout the elbow flexor fatigue protocol and partially recovered 10 min post fatigue. VA was significantly ( p < 0.05) underestimated when using TMS compared to motor point stimulation in non-fatigued and fatigued elbow flexors. Motor point stimulation compared to TMS superimposed twitch forces were significantly ( p < 0.05) higher at 50% MVC but similar at 75 and 100% MVC. The linear relationship between TMS superimposed twitch force and voluntary force significantly ( p < 0.05) decreased with fatigue. There was no change in triceps/biceps electromyography, biceps/triceps MEP amplitudes, or bicep MEP amplitudes throughout the fatigue protocol at 100% MVC. In conclusion, motor point stimulation as opposed to TMS led to a higher estimation of VA in non-fatigued and fatigued elbow flexors. The decreased linear relationship between TMS superimposed twitch force and voluntary force led to an underestimation of the estimated resting twitch force and thus, a reduced VA.

Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors

DOE PAGES

Cui, Shumao; Pu, Haihui; Wells, Spencer A.; ...

2015-10-21

Two-dimensional (2D) layered materials have attracted significant attention for device applications because of their unique structures and outstanding properties. Here, a field-effect transistor (FET) sensor device is fabricated based on 2D phosphorene nanosheets (PNSs). The PNS sensor exhibits an ultrahigh sensitivity to NO 2 in dry air and the sensitivity is dependent on its thickness. A maximum response is observed for 4.8-nm-thick PNS, with a sensitivity up to 190% at 20 parts per billion (p.p.b.) at room temperature. First-principles calculations combined with the statistical thermodynamics modelling predict that the adsorption density is ~10 15 cm -2 for the 4.8-nm-thick PNSmore » when exposed to 20 p.p.b. NO 2 at 300 K. As a result, our sensitivity modelling further suggests that the dependence of sensitivity on the PNS thickness is dictated by the band gap for thinner sheets (<10 nm) and by the effective thickness on gas adsorption for thicker sheets (>10 nm).« less

Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors

NASA Astrophysics Data System (ADS)

Cui, Shumao; Pu, Haihui; Wells, Spencer A.; Wen, Zhenhai; Mao, Shun; Chang, Jingbo; Hersam, Mark C.; Chen, Junhong

2015-10-01

Two-dimensional (2D) layered materials have attracted significant attention for device applications because of their unique structures and outstanding properties. Here, a field-effect transistor (FET) sensor device is fabricated based on 2D phosphorene nanosheets (PNSs). The PNS sensor exhibits an ultrahigh sensitivity to NO2 in dry air and the sensitivity is dependent on its thickness. A maximum response is observed for 4.8-nm-thick PNS, with a sensitivity up to 190% at 20 parts per billion (p.p.b.) at room temperature. First-principles calculations combined with the statistical thermodynamics modelling predict that the adsorption density is ~1015 cm-2 for the 4.8-nm-thick PNS when exposed to 20 p.p.b. NO2 at 300 K. Our sensitivity modelling further suggests that the dependence of sensitivity on the PNS thickness is dictated by the band gap for thinner sheets (<10 nm) and by the effective thickness on gas adsorption for thicker sheets (>10 nm).

Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors

PubMed Central

Cui, Shumao; Pu, Haihui; Wells, Spencer A.; Wen, Zhenhai; Mao, Shun; Chang, Jingbo; Hersam, Mark C.; Chen, Junhong

2015-01-01

Two-dimensional (2D) layered materials have attracted significant attention for device applications because of their unique structures and outstanding properties. Here, a field-effect transistor (FET) sensor device is fabricated based on 2D phosphorene nanosheets (PNSs). The PNS sensor exhibits an ultrahigh sensitivity to NO2 in dry air and the sensitivity is dependent on its thickness. A maximum response is observed for 4.8-nm-thick PNS, with a sensitivity up to 190% at 20 parts per billion (p.p.b.) at room temperature. First-principles calculations combined with the statistical thermodynamics modelling predict that the adsorption density is ∼1015 cm−2 for the 4.8-nm-thick PNS when exposed to 20 p.p.b. NO2 at 300 K. Our sensitivity modelling further suggests that the dependence of sensitivity on the PNS thickness is dictated by the band gap for thinner sheets (<10 nm) and by the effective thickness on gas adsorption for thicker sheets (>10 nm). PMID:26486604

Report to Lincoln Labs on TWPAs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dubois, J.; Carosi, G.; Woollett, N.

2017-09-26

This past spring LLNL’s Quantum Sensor’s team received two TWPA amplifiers from Lincoln Labs along with a data-sheet explaining handling, operations and expected performance. Here we will outline some of the initial tests performed on this amplifiers as part of LLNL’s Quantum Sensors Strategic Initiative (QSSI). Initial testing confirmed that both amplifiers worked and provided gain and SNR improvement similar to that called out in the data-sheets provided.

Transcranial magnetic stimulation over the cerebellum delays predictive head movements in the coordination of gaze.

PubMed

Zangemeister, W H; Nagel, M

2001-01-01

We investigated coordinated saccadic eye and head movements following predictive horizontal visual targets at +/- 30 degrees by applying transcranial magnetic stimulation (TMS) over the cerebellum before the start of the gaze movement in 10 young subjects. We found three effects of TMS on eye-head movements: 1. Saccadic latency effect. When stimulation took place shortly before movements commenced (75-25 ms before), significantly shorter latencies were found between predictive target presentation and initiation of saccades. Eye latencies were significantly decreased by 45 ms on average, but head latencies were not. 2. Gaze amplitude effect. Without TMS, for the 60 degrees target amplitudes, head movements usually preceded eye movements, as expected (predictive gaze type 3). With TMS 5-75 ms before the gaze movement, the number of eye movements preceding head movements by 20-50 ms was significantly increased (p < 0.001) and the delay between eye and head movements was reversed (p < 0.001), i.e. we found eye-predictive gaze type 1. 3. Saccadic peak velocity effect. For TMS 5-25 s before the start of head movement, mean peak velocity of synkinetic eye saccades increased by 20-30% up to 600 degrees/s, compared to 350-400 degrees/s without TMS. We conclude that transient functional cerebellar deficits exerted by means of TMS can change the central synkinesis of eye-head coordination, including the preprogramming of the saccadic pulse and step of a coordinated gaze movement.

A chronometric exploration of high-resolution 'sensitive TMS masking' effects on subjective and objective measures of vision.

PubMed

de Graaf, Tom A; Herring, Jim; Sack, Alexander T

2011-03-01

Transcranial magnetic stimulation (TMS) can induce masking by interfering with ongoing neural activity in early visual cortex. Previous work has explored the chronometry of occipital involvement in vision by using single pulses of TMS with high temporal resolution. However, conventionally TMS intensities have been high and the only measure used to evaluate masking was objective in nature. Recent studies have begun to incorporate subjective measures of vision, alongside objective ones. The current study goes beyond previous work in two regards. First, we explored both objective vision (an orientation discrimination task) and subjective vision (a stimulus visibility rating on a four-point scale), across a wide range of time windows with high temporal resolution. Second, we used a very sensitive TMS-masking paradigm: stimulation was at relatively low TMS intensities, with a figure-8 coil, and the small stimulus was difficult to discriminate already at baseline level. We hypothesized that this should increase the effective temporal resolution of our paradigm. Perhaps for this reason, we are able to report a rather interesting masking curve. Within the classical-masking time window, previously reported to encompass broad SOAs anywhere between 60 and 120 ms, we report not one, but at least two dips in objective performance, with no masking in-between. The subjective measure of vision did not mirror this pattern. These preliminary data from our exploratory design suggest that, with sensitive TMS masking, we might be able to reveal visual processes in early visual cortex previously unreported.

rTMS Induced Tinnitus Relief Is Related to an Increase in Auditory Cortical Alpha Activity

PubMed Central

Müller, Nadia; Lorenz, Isabel; Langguth, Berthold; Weisz, Nathan

2013-01-01

Chronic tinnitus, the continuous perception of a phantom sound, is a highly prevalent audiological symptom. A promising approach for the treatment of tinnitus is repetitive transcranial magnetic stimulation (rTMS) as this directly affects tinnitus-related brain activity. Several studies indeed show tinnitus relief after rTMS, however effects are moderate and vary strongly across patients. This may be due to a lack of knowledge regarding how rTMS affects oscillatory activity in tinnitus sufferers and which modulations are associated with tinnitus relief. In the present study we examined the effects of five different stimulation protocols (including sham) by measuring tinnitus loudness and tinnitus-related brain activity with Magnetoencephalography before and after rTMS. Changes in oscillatory activity were analysed for the stimulated auditory cortex as well as for the entire brain regarding certain frequency bands of interest (delta, theta, alpha, gamma). In line with the literature the effects of rTMS on tinnitus loudness varied strongly across patients. This variability was also reflected in the rTMS effects on oscillatory activity. Importantly, strong reductions in tinnitus loudness were associated with increases in alpha power in the stimulated auditory cortex, while an unspecific decrease in gamma and alpha power, particularly in left frontal regions, was linked to an increase in tinnitus loudness. The identification of alpha power increase as main correlate for tinnitus reduction sheds further light on the pathophysiology of tinnitus. This will hopefully stimulate the development of more effective therapy approaches. PMID:23390539

Inhibitory rTMS applied on somatosensory cortex in Wilson's disease patients with hand dystonia.

PubMed

Lozeron, Pierre; Poujois, Aurélia; Meppiel, Elodie; Masmoudi, Sana; Magnan, Thierry Peron; Vicaut, Eric; Houdart, Emmanuel; Guichard, Jean-Pierre; Trocello, Jean-Marc; Woimant, France; Kubis, Nathalie

2017-10-01

Hand dystonia is a common complication of Wilson's disease (WD), responsible for handwriting difficulties and disability. Alteration of sensorimotor integration and overactivity of the somatosensory cortex have been demonstrated in dystonia. This study investigated the immediate after effect of an inhibitory repetitive transcranial magnetic stimulation (rTMS) applied over the somatosensory cortex on the writing function in WD patients with hand dystonia. We performed a pilot prospective randomized double-blind sham-controlled crossover rTMS study. A 20-min 1-Hz rTMS session, stereotaxically guided, was applied over the left somatosensory cortex in 13 WD patients with right dystonic writer's cramp. After 3 days, each patient was crossed-over to the alternative treatment. Patients were clinically evaluated before and immediately after each rTMS session with the Unified Wilson's Disease rating scale (UWDRS), the Writers' Cramp Rating Scale (WCRS), a specifically designed scale for handwriting difficulties in Wilson's disease patients (FAR, flow, accuracy, and rhythmicity evaluation), and a visual analog scale (VAS) for handwriting discomfort. No significant change in UWDRS, WCRS, VAS, or FAR scores was observed in patients treated with somatosensory inhibitory rTMS compared to the sham protocol. The FAR negatively correlated with UWDRS (r = -0.6; P = 0.02), but not with the WCRS score, disease duration, MRI diffusion lesions, or with atrophy scores. In our experimental conditions, a single inhibitory rTMS session applied over somatosensory cortex did not improve dystonic writer cramp in WD patients.

Preliminary Upper Estimate of Peak Currents in Transcranial Magnetic Stimulation at Distant Locations from a TMS Coil

PubMed Central

Makarov, Sergey N.; Yanamadala, Janakinadh; Piazza, Matthew W.; Helderman, Alex M.; Thang, Niang S.; Burnham, Edward H.; Pascual-Leone, Alvaro

2016-01-01

Goals Transcranial magnetic stimulation (TMS) is increasingly used as a diagnostic and therapeutic tool for numerous neuropsychiatric disorders. The use of TMS might cause whole-body exposure to undesired induced currents in patients and TMS operators. The aim of the present study is to test and justify a simple analytical model known previously, which may be helpful as an upper estimate of eddy current density at a particular distant observation point for any body composition and any coil setup. Methods We compare the analytical solution with comprehensive adaptive mesh refinement-based FEM simulations of a detailed full-body human model, two coil types, five coil positions, about 100,000 observation points, and two distinct pulse rise times, thus providing a representative number of different data sets for comparison, while also using other numerical data. Results Our simulations reveal that, after a certain modification, the analytical model provides an upper estimate for the eddy current density at any location within the body. In particular, it overestimates the peak eddy currents at distant locations from a TMS coil by a factor of 10 on average. Conclusion The simple analytical model tested in the present study may be valuable as a rapid method to safely estimate levels of TMS currents at different locations within a human body. Significance At present, safe limits of general exposure to TMS electric and magnetic fields are an open subject, including fetal exposure for pregnant women. PMID:26685221

Repeated mapping of cortical language sites by preoperative navigated transcranial magnetic stimulation compared to repeated intraoperative DCS mapping in awake craniotomy

PubMed Central

2014-01-01

Background Repetitive navigated transcranial magnetic stimulation (rTMS) was recently described for mapping of human language areas. However, its capability of detecting language plasticity in brain tumor patients was not proven up to now. Thus, this study was designed to evaluate such data in order to compare rTMS language mapping to language mapping during repeated awake surgery during follow-up in patients suffering from language-eloquent gliomas. Methods Three right-handed patients with left-sided gliomas (2 opercular glioblastomas, 1 astrocytoma WHO grade III of the angular gyrus) underwent preoperative language mapping by rTMS as well as intraoperative language mapping provided via direct cortical stimulation (DCS) for initial as well as for repeated Resection 7, 10, and 15 months later. Results Overall, preoperative rTMS was able to elicit clear language errors in all mappings. A good correlation between initial rTMS and DCS results was observed. As a consequence of brain plasticity, initial DCS and rTMS findings only corresponded with the results obtained during the second examination in one out of three patients thus suggesting changes of language organization in two of our three patients. Conclusions This report points out the usefulness but also the limitations of preoperative rTMS language mapping to detect plastic changes in language function or for long-term follow-up prior to DCS even in recurrent gliomas. However, DCS still has to be regarded as gold standard. PMID:24479694

Phonological decisions require both the left and right supramarginal gyri.

PubMed

Hartwigsen, Gesa; Baumgaertner, Annette; Price, Cathy J; Koehnke, Maria; Ulmer, Stephan; Siebner, Hartwig R

2010-09-21

Recent functional imaging studies demonstrated that both the left and right supramarginal gyri (SMG) are activated when healthy right-handed subjects make phonological word decisions. However, lesion studies typically report difficulties with phonological processing after left rather than right hemisphere damage. Here, we used a unique dual-site transcranial magnetic stimulation (TMS) approach to test whether the SMG in the right hemisphere contributes to modality-independent (i.e., auditory and visual) phonological decisions. To test task-specificity, we compared the effect of real or sham TMS during phonological, semantic, and perceptual decisions. To test laterality and anatomical specificity, we compared the effect of TMS over the left, right, or bilateral SMG and angular gyri. The accuracy and reaction times of phonological decisions were selectively disrupted relative to semantic and perceptual decisions when real TMS was applied over the left, right, or bilateral SMG. These effects were not observed for TMS over the angular gyri. A follow-up experiment indicated that the threshold-intensity for inducing a disruptive effect on phonological decisions was identical for unilateral TMS over the right or left SMG. Taken together, these findings provide converging evidence that the right SMG contributes to accurate and efficient phonological decisions in the healthy brain, with no evidence that the left and right SMG can compensate for one another during TMS. Our findings motivate detailed studies of phonological processing in patients with acute or long-term damage of the right SMG.

Reliability of TMS metrics in patients with chronic incomplete spinal cord injury.

PubMed

Potter-Baker, K A; Janini, D P; Frost, F S; Chabra, P; Varnerin, N; Cunningham, D A; Sankarasubramanian, V; Plow, E B

2016-11-01

Test-retest reliability analysis in individuals with chronic incomplete spinal cord injury (iSCI). The purpose of this study was to examine the reliability of neurophysiological metrics acquired with transcranial magnetic stimulation (TMS) in individuals with chronic incomplete tetraplegia. Cleveland Clinic Foundation, Cleveland, Ohio, USA. TMS metrics of corticospinal excitability, output, inhibition and motor map distribution were collected in muscles with a higher MRC grade and muscles with a lower MRC grade on the more affected side of the body. Metrics denoting upper limb function were also collected. All metrics were collected at two sessions separated by a minimum of two weeks. Reliability between sessions was determined using Spearman's correlation coefficients and concordance correlation coefficients (CCCs). We found that TMS metrics that were acquired in higher MRC grade muscles were approximately two times more reliable than those collected in lower MRC grade muscles. TMS metrics of motor map output, however, demonstrated poor reliability regardless of muscle choice (P=0.34; CCC=0.51). Correlation analysis indicated that patients with more baseline impairment and/or those in a more chronic phase of iSCI demonstrated greater variability of metrics. In iSCI, reliability of TMS metrics varies depending on the muscle grade of the tested muscle. Variability is also influenced by factors such as baseline motor function and time post SCI. Future studies that use TMS metrics in longitudinal study designs to understand functional recovery should be cautious as choice of muscle and clinical characteristics can influence reliability.

Neuroimaging Mechanisms of Therapeutic Transcranial Magnetic Stimulation for Major Depressive Disorder.

PubMed

Philip, Noah S; Barredo, Jennifer; Aiken, Emily; Carpenter, Linda L

2018-03-01

Research into therapeutic transcranial magnetic stimulation (TMS) for major depression has dramatically increased in the last decade. Understanding the mechanism of action of TMS is crucial to improve efficacy and develop the next generation of therapeutic stimulation. Early imaging research provided initial data supportive of widely held assumptions about hypothesized inhibitory or excitatory consequences of stimulation. Early work also indicated that while TMS modulated brain activity under the stimulation site, effects at deeper regions, in particular, the subgenual anterior cingulate cortex, were associated with clinical improvement. Concordant with earlier findings, functional connectivity studies also demonstrated that clinical improvements were related to changes distal, rather than proximal, to the site of stimulation. Moreover, recent work suggests that TMS modulates and potentially normalizes functional relationships between neural networks. An important observation that emerged from this review is that similar patterns of connectivity changes are observed across studies regardless of TMS parameters. Though promising, we stress that these imaging findings must be evaluated cautiously given the widespread reliance on modest sample sizes and little implementation of statistical validation. Additional limitations included use of imaging before and after a course of TMS, which provided little insight into changes that might occur during the weeks of stimulation. Furthermore, as studies to date have focused on depression, it is unclear whether our observations were related to mechanisms of action of TMS for depression or represented broader patterns of functional brain changes associated with clinical improvement. Published by Elsevier Inc.

Enhanced light harvesting of dye-sensitized solar cells with TiO2 microspheres as light scattering layer

NASA Astrophysics Data System (ADS)

Guan, Yingli; Song, Lixin; Zhou, Yangyang; Yin, Xin; Xie, Xueyao; Xiong, Jie

2017-03-01

Two kinds of TiO2 microspheres (TMS) with average diameter of 1500 nm but different surface were fabricated by solvothermal method from different Ti source. The effect of TMS on the light harvesting and photovoltaic performance of dye-sensitized solar cells (DSSCs)was investigated. The UV-Vis diffusion reflectance spectra and absorption spectra of N719 dye in detached solutions proved that the TMS showed dual functions of light scattering and dye-adsorption which was an important functional material in DSSCs. The results showed that the TMS made from titanium(IV) isopropoxide with rough surface (TMSR) exhibited better photovoltaic performance than that of TMS made from tetrabutyl titanate with smooth surface (TMSS). To further improve the photovoltaic performance, the double-layered DSSCs made of P25 as an underlayer and TMS as a light-scattering layer (P25-TMS) were fabricated. The photovoltaic performance of double-layered DSSCs was higher than that of the single-layered DSSCs with similar thickness. Especially, the DSSCs made of P25 as an underlayer and the TMSR as a light-scattering layer (P25-TMSR) had a highest power conversion efficiency of 7.62%. This was higher than that of single-layered TMSR-based cell (5.54%), P25-based cell (5.75%), and double-layered P25-TMSS-based cell (6.78%) with similar thickness. This was mainly attributed to the large specific surface area, superior light scattering ability, and fast electron transport of TMSR.

Transcranial magnetic stimulation (TMS) for major depression: a multisite, naturalistic, observational study of quality of life outcome measures in clinical practice.

PubMed

Janicak, Philip G; Dunner, David L; Aaronson, Scott T; Carpenter, Linda L; Boyadjis, Terrence A; Brock, David G; Cook, Ian A; Lanocha, Karl; Solvason, Hugh B; Bonneh-Barkay, Dafna; Demitrack, Mark A

2013-12-01

Transcranial magnetic stimulation (TMS) is an effective and safe therapy for major depressive disorder (MDD). This study assessed quality of life (QOL) and functional status outcomes for depressed patients after an acute course of TMS. Forty-two, U.S.-based, clinical TMS practice sites treated 307 outpatients with a primary diagnosis of MDD and persistent symptoms despite prior adequate antidepressant pharmacotherapy. Treatment parameters were based on individual clinical considerations and followed the labeled procedures for use of the approved TMS device. Patient self-reported QOL outcomes included change in the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the EuroQol 5-Dimensions (EQ-5D) ratings from baseline to end of the acute treatment phase. Statistically significant improvement in functional status on a broad range of mental health and physical health domains was observed on the SF-36 following acute TMS treatment. Similarly, statistically significant improvement in patient-reported QOL was observed on all domains of the EQ-5D and on the General Health Perception and Health Index scores. Improvement on these measures was observed across the entire range of baseline depression symptom severity. These data confirm that TMS is effective in the acute treatment of MDD in routine clinical practice settings. This symptom benefit is accompanied by statistically and clinically meaningful improvements in patient-reported QOL and functional status outcomes.

The Efficacy of Daily Prefrontal Repetitive Transcranial Magnetic Stimulation (rTMS) for Burning Mouth Syndrome (BMS): A Randomized Controlled Single-blind Study.

PubMed

Umezaki, Yojiro; Badran, Bashar W; DeVries, William H; Moss, Jkeonye; Gonzales, Theresa; George, Mark S

2016-01-01

Burning mouth syndrome (BMS) is a burning oral sensation without any corresponding abnormal findings. In some cases, BMS is refractory to pharmacologic treatments. Repetitive transcranial magnetic stimulation (rTMS) over left prefrontal cortex induces analgesic effect in both acute and chronic pain. However, its effect for BMS has not been evaluated. The aim of this randomized, controlled, single-blind study was to assess the efficacy of prefrontal rTMS for BMS. Twenty patients with BMS were recruited and randomized to receive 30,000 pulses in total at 10 Hz TMS (n = 12) or sham TMS (n = 8). We assessed the change of BMS pain condition, functional status and mood until 2 months after the beginning of treatment. In the real group, the BMS pain intensity decreased 67%, and 75% of the patients reported >50% pain decrease on final assessment compared to baseline, without heavy side effects. There was significant pain reduction in subjects in the real group immediately after 1 week of treatment, whereas there was none in those in the sham group. Similar tendency was confirmed in change of functional status. Mood and the affective aspect of pain were not changed in this study. BMS pain was significantly improved with 2 weeks of treatment of high frequency rTMS over left DLPFC compared to sham stimulation. Further study is needed to refine and improve TMS as a potential treatment of BMS. Copyright © 2016 Elsevier Inc. All rights reserved.

Language mapping with navigated transcranial magnetic stimulation in pediatric and adult patients undergoing epilepsy surgery: Comparison with extraoperative direct cortical stimulation.

PubMed

Lehtinen, Henri; Mäkelä, Jyrki P; Mäkelä, Teemu; Lioumis, Pantelis; Metsähonkala, Liisa; Hokkanen, Laura; Wilenius, Juha; Gaily, Eija

2018-06-01

Navigated transcranial magnetic stimulation (nTMS) is becoming increasingly popular in noninvasive preoperative language mapping, as its results correlate well enough with those obtained by direct cortical stimulation (DCS) during awake surgery in adult patients with tumor. Reports in the context of epilepsy surgery or extraoperative DCS in adults are, however, sparse, and validation of nTMS with DCS in children is lacking. Furthermore, little is known about the risk of inducing epileptic seizures with nTMS in pediatric epilepsy patients. We provide the largest validation study to date in an epilepsy surgery population. We compared language mapping with nTMS and extraoperative DCS in 20 epilepsy surgery patients (age range 9-32 years; 14 children and adolescents). In comparison with DCS, sensitivity of nTMS was 68%, specificity 76%, positive predictive value 27%, and negative predictive value 95%. Age, location of ictal-onset zone near or within DCS-mapped language areas or severity of cognitive deficits had no significant effect on these values. None of our patients had seizures during nTMS. Our study suggests that nTMS language mapping is clinically useful and safe in epilepsy surgery patients, including school-aged children and patients with extensive cognitive dysfunction. Similar to in tumor surgery, mapping results in the frontal region are most reliable. False negative findings may be slightly more likely in epilepsy than in tumor surgery patients. Mapping results should always be verified by other methods in individual patients.

Transcranial magnetic stimulation changes response selectivity of neurons in the visual cortex

PubMed Central

Kim, Taekjun; Allen, Elena A.; Pasley, Brian N.; Freeman, Ralph D.

2015-01-01

Background Transcranial magnetic stimulation (TMS) is used to selectively alter neuronal activity of specific regions in the cerebral cortex. TMS is reported to induce either transient disruption or enhancement of different neural functions. However, its effects on tuning properties of sensory neurons have not been studied quantitatively. Objective/Hypothesis Here, we use specific TMS application parameters to determine how they may alter tuning characteristics (orientation, spatial frequency, and contrast sensitivity) of single neurons in the cat’s visual cortex. Methods Single unit spikes were recorded with tungsten microelectrodes from the visual cortex of anesthetized and paralyzed cats (12 males). Repetitive TMS (4Hz, 4sec) was delivered with a 70mm figure-8 coil. We quantified basic tuning parameters of individual neurons for each pre- and post-TMS condition. The statistical significance of changes for each tuning parameter between the two conditions was evaluated with a Wilcoxon signed-rank test. Results We generally find long-lasting suppression which persists well beyond the stimulation period. Pre- and post-TMS orientation tuning curves show constant peak values. However, strong suppression at non-preferred orientations tends to narrow the widths of tuning curves. Spatial frequency tuning exhibits an asymmetric change in overall shape, which results in an emphasis on higher frequencies. Contrast tuning curves show nonlinear changes consistent with a gain control mechanism. Conclusions These findings suggest that TMS causes extended interruption of the balance between sub-cortical and intra-cortical inputs. PMID:25862599

Bioaccessible trace metals in lip cosmetics and their health risks to female consumers.

PubMed

Gao, Peng; Lei, Tingting; Jia, Liming; Yury, Badmatsybenov; Zhang, Zhaohan; Du, Yingqiu; Feng, Yujie; Xing, Baoshan

2018-07-01

Females can be exposed to toxic elements in lip cosmetics following ingestion. The bioaccessibility of Cr, Mn, Co, Ni, Cu, Cd, Sb and Pb in lip cosmetics (n = 32) were assessed via the dilute HCl extraction method, In Vitro Gastrointestinal protocol (IVG) and the United States Pharmacopeia Methodology (USPM), and then health risks were characterized. The total concentrations of trace metals (TMs) in lip cosmetics were in the range of 15.55-111.97 mg/kg (Mean: 60.99 mg/kg). Cu, Pb and Cr were the three major TMs and accounting for >75% of the total concentrations. Except Sb and Pb in 4/32 and 4/32 samples were higher than the US FDA (Food and Drug Administration of the United States) limits, the other TMs were lower than that limits. Only bioaccessible Pb in all samples significantly exceeded the FDA limit 0.1 mg/kg in candy. Using IVG or USPM might be preferable for evaluating the TMs exposure over HCl since they better represent gastrointestinal physiology. The estimated average daily intake (ADI) of bioaccessible ∑TMs through lip cosmetics ingestion of career women and female college students were under safety level. The long-term exposure of bioaccessible TMs by lip cosmetics using would inevitably cause non-carcinogenic health risk. This is the first report on the in vitro tests used for evaluating bioaccessible TMs in lip cosmetics. Copyright © 2018. Published by Elsevier Ltd.

Neural Correlates of the Antinociceptive Effects of Repetitive Transcranial Magnetic Stimulation on Central Pain After Stroke

PubMed Central

Ohn, Suk Hoon; Chang, Won Hyuk; Park, Chang-hyun; Kim, Sung Tae; Lee, Jung Il; Pascual-Leone, Alvaro; Kim, Yun-Hee

2013-01-01

Background Repetitive transcranial magnetic stimulation (rTMS) modulates central neuropathic pain in some patients after stroke, but the mechanisms of action are uncertain. Objective The authors used diffusion tensor imaging (DTI) and functional MRI (fMRI) to evaluate the integrity of the thalamocortical tract (TCT) and the activation pattern of the pain network in 22 patients with poststroke central pain. Methods Each patient underwent daily 10-Hz rTMS sessions for 1000 pulses on 5 consecutive days over the hotspot for the first dorsal interosseus muscle. Pain severity was monitored using the Visual Analogue Scale (VAS). Mood was assessed by the Hamilton Depression Rating Scale. Results Clinical data from all participants along with the DTI and fMRI findings from 10 patients were analyzed. VAS scores decreased significantly, if modestly, following administration of rTMS in 14 responders, which lasted for 2 weeks after the intervention. Regression analysis showed a significant correlation between less initial depression and higher antalgic effect of rTMS. Integrity of the superior TCT in the ipsilesional hemisphere showed significant correlation with change of VAS score after rTMS. fMRI showed significantly decreased activity in the secondary somatosensory cortex, insula, prefrontal cortex, and putamen in rTMS responders, whereas no change was noted in nonresponders. Conclusion Mood may affect the modest antinociceptive effects of rTMS that we found, which may be mediated by the superior TCT through modulation of a distributed pain network. PMID:21980153

Three dimensional stress vector sensor array and method therefor

DOEpatents

Pfeifer, Kent Bryant; Rudnick, Thomas Jeffery

2005-07-05

A sensor array is configured based upon capacitive sensor techniques to measure stresses at various positions in a sheet simultaneously and allow a stress map to be obtained in near real-time. The device consists of single capacitive elements applied in a one or two dimensional array to measure the distribution of stresses across a mat surface in real-time as a function of position for manufacturing and test applications. In-plane and normal stresses in rolling bodies such as tires may thus be monitored.

Magnetic Stimulation and Epilepsy

DTIC Science & Technology

2013-10-14

the seizure-induced groups exhibited varying degrees of EEG activity reduction. Figure 2. The effects of TMS on penicillin-induced seizures...the EEG recording including (a) baseline (pre-penicillin injection), (b) 30-min post-penicillin injection (30min-PI), (c) 10-min post- TMS stimulation...stable conditions 55% faster, and the 5 pps TMS -treated group 78% faster. Figure 3. Maximum frequency relationships in EEG activity among the

Low-frequency repetitive transcranial magnetic stimulation (rTMS) affects event-related potential measures of novelty processing in autism.

PubMed

Sokhadze, Estate; Baruth, Joshua; Tasman, Allan; Mansoor, Mehreen; Ramaswamy, Rajesh; Sears, Lonnie; Mathai, Grace; El-Baz, Ayman; Casanova, Manuel F

2010-06-01

In our previous study on individuals with autism spectrum disorder (ASD) (Sokhadze et al., Appl Psychophysiol Biofeedback 34:37-51, 2009a) we reported abnormalities in the attention-orienting frontal event-related potentials (ERP) and the sustained-attention centro-parietal ERPs in a visual oddball experiment. These results suggest that individuals with autism over-process information needed for the successful differentiation of target and novel stimuli. In the present study we examine the effects of low-frequency, repetitive Transcranial Magnetic Stimulation (rTMS) on novelty processing as well as behavior and social functioning in 13 individuals with ASD. Our hypothesis was that low-frequency rTMS application to dorsolateral prefrontal cortex (DLFPC) would result in an alteration of the cortical excitatory/inhibitory balance through the activation of inhibitory GABAergic double bouquet interneurons. We expected to find post-TMS differences in amplitude and latency of early and late ERP components. The results of our current study validate the use of low-frequency rTMS as a modulatory tool that altered the disrupted ratio of cortical excitation to inhibition in autism. After rTMS the parieto-occipital P50 amplitude decreased to novel distracters but not to targets; also the amplitude and latency to targets increased for the frontal P50 while decreasing to non-target stimuli. Low-frequency rTMS minimized early cortical responses to irrelevant stimuli and increased responses to relevant stimuli. Improved selectivity in early cortical responses lead to better stimulus differentiation at later-stage responses as was made evident by our P3b and P3a component findings. These results indicate a significant change in early, middle-latency and late ERP components at the frontal, centro-parietal, and parieto-occipital regions of interest in response to target and distracter stimuli as a result of rTMS treatment. Overall, our preliminary results show that rTMS may prove to be an important research tool or treatment modality in addressing the stimulus hypersensitivity characteristic of autism spectrum disorders.

The Effects of Different Repetitive Transcranial Magnetic Stimulation (rTMS) Protocols on Cortical Gene Expression in a Rat Model of Cerebral Ischemic-Reperfusion Injury

PubMed Central

Ljubisavljevic, Milos R.; Javid, Asma; Oommen, Joji; Parekh, Khatija; Nagelkerke, Nico; Shehab, Safa; Adrian, Thomas E.

2015-01-01

Although repetitive Transcranial Magnetic Stimulation (rTMS) in treatment of stroke in humans has been explored over the past decade the data remain controversial in terms of optimal stimulation parameters and the mechanisms of rTMS long-term effects. This study aimed to explore the potential of different rTMS protocols to induce changes in gene expression in rat cortices after acute ischemic-reperfusion brain injury. The stroke was induced by middle cerebral artery occlusion (MCAO) with subsequent reperfusion. Changes in the expression of 96 genes were examined using low-density expression arrays after MCAO alone and after MCAO combined with 1Hz, 5Hz, continuous (cTBS) and intermittent (iTBS) theta-burst rTMS. rTMS over the lesioned hemisphere was given for two weeks (with a 2-day pause) in a single daily session and a total of 2400 pulses. MCAO alone induced significant upregulation in the expression of 44 genes and downregulation in 10. Two weeks of iTBS induced significant increase in the expression of 52 genes. There were no downregulated genes. 1Hz and 5Hz had no significant effects on gene expression, while cTBS effects were negligible. Upregulated genes included those involved in angiogenesis, inflammation, injury response and cellular repair, structural remodeling, neuroprotection, neurotransmission and neuronal plasticity. The results show that long-term rTMS in acute ischemic-reperfusion brain injury induces complex changes in gene expression that span multiple pathways, which generally promote the recovery. They also demonstrate that induced changes primarily depend on the rTMS frequency (1Hz and 5Hz vs. iTBS) and pattern (cTBS vs. iTBS). The results further underlines the premise that one of the benefits of rTMS application in stroke may be to prime the brain, enhancing its potential to cope with the injury and to rewire. This could further augment its potential to favorably respond to rehabilitation, and to restore some of the loss functions. PMID:26431529

Facile and efficient electrochemical enantiomer recognition of phenylalanine using β-Cyclodextrin immobilized on reduced graphene oxide.

PubMed

Zaidi, Shabi Abbas

2017-08-15

This work demonstrates the facile and efficient preparation protocol of β-Cyclodextrin-reduced graphene oxide modified glassy carbon electrode (β-CD/RGO/GCE) sensor for an impressive chiral selectivity analysis for phenylalanine enantiomers. In this work, the immobilization of β-CD over graphene sheets allows the excellent enantiomer recognition due to the large surface area and high conductivity of graphene sheets and extraordinary supramolecular (host-guest interaction) property of β-CD. The proposed sensor was well characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and electrochemical impedance spectroscopy (EIS) techniques. The analytical studies demonstrated that the β-CD/RGO/GCE exhibit superior chiral recognition toward L-phenylalanine as compared to D-phenylalanine. Under optimum conditions, the developed sensor displayed a good linear range from 0.4 to 40µM with the limit of detection (LOD) values of 0.10µM and 0.15µM for l- and D-phenylalanine, respectively. Furthermore, the proposed sensor exhibits good stability and regeneration capacity. Thus, the as-synthesized material can be exploited for electrochemical enantiomer recognition successfully. Copyright © 2017 Elsevier B.V. All rights reserved.

Mutual Inductance Problem for a System Consisting of a Current Sheet and a Thin Metal Plate

NASA Technical Reports Server (NTRS)

Fulton, J. P.; Wincheski, B.; Nath, S.; Namkung, M.

1993-01-01

Rapid inspection of aircraft structures for flaws is of vital importance to the commercial and defense aircraft industry. In particular, inspecting thin aluminum structures for flaws is the focus of a large scale R&D effort in the nondestructive evaluation (NDE) community. Traditional eddy current methods used today are effective, but require long inspection times. New electromagnetic techniques which monitor the normal component of the magnetic field above a sample due to a sheet of current as the excitation, seem to be promising. This paper is an attempt to understand and analyze the magnetic field distribution due to a current sheet above an aluminum test sample. A simple theoretical model, coupled with a two dimensional finite element model (FEM) and experimental data will be presented in the next few sections. A current sheet above a conducting sample generates eddy currents in the material, while a sensor above the current sheet or in between the two plates monitors the normal component of the magnetic field. A rivet or a surface flaw near a rivet in an aircraft aluminum skin will disturb the magnetic field, which is imaged by the sensor. Initial results showed a strong dependence of the flaw induced normal magnetic field strength on the thickness and conductivity of the current-sheet that could not be accounted for by skin depth attenuation alone. It was believed that the eddy current imaging method explained the dependence of the thickness and conductivity of the flaw induced normal magnetic field. Further investigation, suggested the complexity associated with the mutual inductance of the system needed to be studied. The next section gives an analytical model to better understand the phenomenon.

Repetitive Transcranial Magnetic Stimulation for Treatment-Resistant Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PubMed Central

Sehatzadeh, Shayan; Tu, Hong Anh; Palimaka, Stefan; Yap, Belinda; O'Reilly, Daria; Bowen, Jim; Higgins, Caroline; Holubowich, Corinne

2016-01-01

Background To date, several randomized controlled trials (RCTs) have shown the efficacy of repetitive transcranial magnetic stimulation (rTMS) in the treatment of major depression. Objective This analysis examined the antidepressant efficacy of rTMS in patients with treatment-resistant unipolar depression. Methods A literature search was performed for RCTs published from January 1, 1994, to November 20, 2014. The search was updated on March 1, 2015. Two independent reviewers evaluated the abstracts for inclusion, reviewed full texts of eligible studies, and abstracted data. Meta-analyses were conducted to obtain summary estimates. The primary outcome was changes in depression scores measured by the Hamilton Rating Scale for Depression (HRSD), and we considered, a priori, the mean difference of 3.5 points to be a clinically important treatment effect. Remission and response to the treatment were secondary outcomes, and we calculated number needed to treat on the basis of these outcomes. We examined the possibility of publication bias by constructing funnel plots and by Begg's and Egger's tests. A meta-regression was undertaken to examine the effect of specific rTMS technical parameters on the treatment effects. Results Twenty-three RCTs compared rTMS with sham, and six RCTs compared rTMS with electroconvulsive therapy (ECT). Trials of rTMS versus sham showed a statistically significant improvement in depression scores with rTMS (weighted mean difference [WMD] 2.31, 95% CI 1.19–3.43; P < .001). This improvement was smaller than the pre-specified clinically important treatment effect. There was a 10% absolute difference between rTMS and sham in the rates of remission or response. This translates to a number needed to treat of 10. Risk ratios for remission and response were 2.20 (95% CI 1.44–3.38, P = .001 and 1.72 [95% CI], 1.13–2.62, P = .01), respectively, favouring rTMS. No publication bias was detected. Trials of rTMS versus ECT showed a statistically and clinically significant difference between rTMS and ECT in favour of ECT (WMD 5.97, 95% CI 0.94–11.0, P = .02). Risk ratios for remission and response were 1.44 (95% CI 0.64–3.23, P = .38) and 1.72 (95% CI 0.95–3.11, P = .07), respectively, favouring ECT. Conclusions Overall, the body of evidence favoured ECT for treatment of patients who are treatment-resistant. Repetitive transcranial magnetic stimulation had a small short-term effect for improving depression in comparison with sham, but follow-up studies did not show that the small effect will continue for longer periods. PMID:27099642

Is Life better after motor cortex stimulation for pain control? Results at long-term and their prediction by preoperative rTMS.

PubMed

André-Obadia, Nathalie; Mertens, Patrick; Lelekov-Boissard, Taïssia; Afif, Afif; Magnin, Michel; Garcia-Larrea, Luis

2014-01-01

A positive effect of motor cortex stimulation (MCS) (defined as subjective estimations of pain relief ≥ 30%) has been reported in 55 - 64% of patients. Repetitive magnetic cortical stimulation (rTMS) is considered a predictor of MCS effect. These figures are, however, mostly based on subjective reports of pain intensity, and have not been confirmed in the long-term. This study assessed long-term pain relief (2 - 9 years) after epidural motor cortex stimulation and its pre-operative prediction by rTMS, using both intensity and Quality of Life (QoL) scales. Analysis of the long-term evolution of pain patients treated by epidural motor cortex stimulation, and predictive value of preoperative response to rTMS. University Neurological Hospital Pain Center. Twenty patients suffering chronic pharmaco-resistant neuropathic pain. All patients received first randomized sham vs. active 20 Hz-rTMS, before being submitted to MCS surgery. Postoperative pain relief was evaluated at 6 months and then up to 9 years post-MCS (average 6.1 ± 2.6 y) using (i) pain numerical rating scores (NRS); (ii) a combined assessment (CPA) including NRS, drug intake, and subjective quality of life; and (iii) a short questionnaire (HowRu) exploring discomfort, distress, disability, and dependence. Pain scores were significantly reduced by active (but not sham) rTMS and by subsequent MCS. Ten out of 20 patients kept a long-term benefit from MCS, both on raw pain scores and on CPA. The CPA results were strictly comparable when obtained by the surgeon or by a third-party on telephonic survey (r = 0.9). CPA scores following rTMS and long-term MCS were significantly associated (Fisher P = 0.02), with 90% positive predictive value and 67% negative predictive value of preoperative rTMS over long-term MCS results. On the HowRu questionnaire, long-term MCS-related improvement concerned "discomfort" (physical pain) and "dependence" (autonomy for daily activities), whereas "disability" (work, home, and leisure activities) and "distress" (anxiety, stress, depression) did not significantly improve. Limited cohort of patients with inhomogeneous pain etiology. Subjectivity of the reported items by the patient after a variable and long delay after surgery. Predictive evaluation based on a single rTMS session compared to chronic MCS. Half of the patients still retain a significant benefit after 2 - 9 years of continuous MCS, and this can be reasonably predicted by preoperative rTMS. Adding drug intake and QoL estimates to raw pain scores allows a more realistic assessment of long-term benefits and enhance the rTMS predictive value. The aims of this study and its design were approved by the local ethics committee (University Hospitals St Etienne and Lyon, France).

Telerobotic management system: coordinating multiple human operators with multiple robots

NASA Astrophysics Data System (ADS)

King, Jamie W.; Pretty, Raymond; Brothers, Brendan; Gosine, Raymond G.

2003-09-01

This paper describes an application called the Tele-robotic management system (TMS) for coordinating multiple operators with multiple robots for applications such as underground mining. TMS utilizes several graphical interfaces to allow the user to define a partially ordered plan for multiple robots. This plan is then converted to a Petri net for execution and monitoring. TMS uses a distributed framework to allow robots and operators to easily integrate with the applications. This framework allows robots and operators to join the network and advertise their capabilities through services. TMS then decides whether tasks should be dispatched to a robot or a remote operator based on the services offered by the robots and operators.

Acute Frontal Lobe Dysfunction Following Prefrontal Low-Frequency Repetitive Transcranial Magnetic Stimulation in a Patient with Treatment-Resistant Depression

PubMed Central

Carle, Guilhem; Touat, Mehdi; Bruno, Nicolas; Galanaud, Damien; Peretti, Charles-Siegfried; Valero-Cabré, Antoni; Levy, Richard; Azuar, Carole

2017-01-01

The potential of repetitive transcranial magnetic stimulation (rTMS) to treat numerous neurological and psychiatric disorders has been thoroughly studied for the last two decades. Here, we report for the first time, the case of a 65-year-old woman suffering from treatment-resistant depression who developed an acute frontal lobe syndrome following eight sessions of low-frequency rTMS (LF-rTMS) to the right dorsolateral prefrontal cortex while also treated with sertraline and mianserin. The pathophysiological mechanisms underlying such an unexpected acute frontal lobe dysfunction are discussed in relation to the therapeutic use of LF-rTMS in combination with pharmacotherapy in depressed patients. PMID:28611694

A case of cerebral reversible vasoconstriction syndrome triggered by repetition transcranial magnetic stimulation.

PubMed

Sato, Mamiko; Yamate, Koji; Hayashi, Hiromi; Miura, Toyoaki; Kobayashi, Yasutaka

2017-08-31

A 75-year-old man was admitted for combined low-frequency repetitive transcranial magnetic stimulation (rTMS) and intensive occupational therapy. Five days after the initiation of rTMS, he developed hypotension and temporary exacerbation of the right hemiplegia with thunderclap headache. MRA showed segmental stenosis of the left middle cerebral artery, which findings were improved at 9 days after the onset of the headache. He was diagnosed as having the reversible cerebral vasoconstriction syndrome (RCVS). The rTMS was recognized as safe rehabilitation treatment. However, it is necessary to recognize that RCVS can become one of the precipitants. This is the first report of RCVS triggered by rTMS.

The role of medial prefrontal cortex in theory of mind: a deep rTMS study.

PubMed

Krause, Laura; Enticott, Peter G; Zangen, Abraham; Fitzgerald, Paul B

2012-03-01

Neuroimaging studies suggest that the medial prefrontal cortex (mPFC) plays a central role in cognitive theory of mind (ToM). This can be assessed more definitively, however, using repetitive transcranial magnetic stimulation (rTMS). Sixteen healthy participants (10 females, 6 males) completed tasks assessing cognitive and affective ToM following low-frequency deep rTMS to bilateral mPFC in active-stimulation and placebo-stimulation sessions. There was no effect of deep rTMS on either cognitive or affective ToM performance. When examining self-reported empathy, however, there was evidence for a double dissociation: deep rTMS disrupted affective ToM performance for those with high self-reported empathy, but improved affective ToM performance for those with low self-reported empathy. mPFC appears to play a role in affective ToM processing, but the present study suggest that stimulation outcomes are dependent on baseline empathic abilities. Copyright © 2011 Elsevier B.V. All rights reserved.

What is said or how it is said makes a difference: role of the right fronto-parietal operculum in emotional prosody as revealed by repetitive TMS.

PubMed

van Rijn, Sophie; Aleman, André; van Diessen, Eric; Berckmoes, Celine; Vingerhoets, Guy; Kahn, René S

2005-06-01

Emotional signals in spoken language can be conveyed by semantic as well as prosodic cues. We investigated the role of the fronto-parietal operculum, a somatosensory area where the lips, tongue and jaw are represented, in the right hemisphere to detection of emotion in prosody vs. semantics. A total of 14 healthy volunteers participated in the present experiment, which involved transcranial magnetic stimulation (TMS) in combination with frameless stereotaxy. As predicted, compared with sham stimulation, TMS over the right fronto-parietal operculum differentially affected the reaction times for detection of emotional prosody vs. emotional semantics, showing that there is a dissociation at a neuroanatomical level. Detection of withdrawal emotions (fear and sadness) in prosody was delayed significantly by TMS. No effects of TMS were observed for approach emotions (happiness and anger). We propose that the right fronto-parietal operculum is not globally involved in emotion evaluation, but sensitive to specific forms of emotional discrimination and emotion types.

The role of the inferior frontal gyri in cognitive processing of patients with Parkinson's disease: a pilot rTMS study.

PubMed

Srovnalova, Hana; Marecek, Radek; Rektorova, Irena

2011-07-01

We studied whether 1 session of high-frequency repetitive transcranial magnetic stimulation (rTMS) applied sequentially over both the left and right inferior frontal gyri (IFG) would enhance performance in tests evaluating the ability to inhibit habitual responses (Stroop test, ST; Frontal Assessment Battery, FAB) in patients with Parkinson's disease (PD). Ten nondemented PD patients (6 men, 4 women; age, 66 ± 6 years; disease duration, 5.4 ± 2.45 years) entered the randomized, sham stimulation-controlled study with a crossover design. The ST and the FAB were performed prior to and immediately after an appropriate rTMS session. The active but not sham rTMS induced significant improvement in all ST subtests (word, color, color-word). Conversely, the calculated Stroop interference and the FAB scores remained unchanged. In PD patients, rTMS of the IFG increased the speed of cognitive processing in both the congruent and incongruent conditions of the ST. Copyright © 2011 Movement Disorder Society.

Repetitive transcranial magnetic stimulation for generalised anxiety disorder: a pilot randomised, double-blind, sham-controlled trial.

PubMed

Diefenbach, Gretchen J; Bragdon, Laura B; Zertuche, Luis; Hyatt, Christopher J; Hallion, Lauren S; Tolin, David F; Goethe, John W; Assaf, Michal

2016-09-01

Repetitive transcranial magnetic stimulation (rTMS) holds promise for treating generalised anxiety disorder (GAD) but has only been studied in uncontrolled research. This is the first randomised controlled trial (clinicaltrials.gov: NCT01659736) to investigate the efficacy and neural correlates of rTMS in GAD. Twenty five participants (active n = 13; sham, n = 12) enrolled. rTMS was targeted at the right dorsolateral prefrontal cortex (DLPFC, 1 Hz, 90% resting motor threshold). Response and remission rates were higher in the active v. sham groups and there were significant group × time interactions for anxiety, worry and depressive symptoms, favouring active v. sham. In addition, right DLPFC activation during a decision-making gambling task increased at post-treatment for active rTMS only, and changes in neuroactivation correlated significantly with changes in worry symptoms. Findings provide preliminary evidence that rTMS may improve GAD symptoms in association with modifying neural activity in the stimulation site. © The Royal College of Psychiatrists 2016.

The role of the prefrontal cortex in controlling gender-stereotypical associations: a TMS investigation.

PubMed

Cattaneo, Zaira; Mattavelli, Giulia; Platania, Elisa; Papagno, Costanza

2011-06-01

Stereotypes associated with gender, race, ethnicity and religion are powerful forces in human social interactions. Previous neuroimaging and neuropsychological studies point to a role of the prefrontal cortex in controlling stereotypical responses. Here we used transcranial magnetic stimulation (TMS) in combination with an Implicit Association Test (IAT) to highlight the possible causal role of the left dorsolateral prefrontal cortex (DLPFC) and the right anterior dorsomedial prefrontal cortex (aDMPFC) in controlling gender-stereotypical responses. Young male and female participants were tested. Our results showed that applying TMS over the left DLPFC and the right aDMPFC increased the gender-stereotypical bias in male participants compared to when TMS was applied to a control site (vertex). This suggests that both the left DLPFC and the right aDMPFC play a direct role in stereotyping. Females did not show a significant gender bias on the IAT; correspondingly their responses were unaffected by TMS. Copyright © 2011 Elsevier Inc. All rights reserved.

TMS suppression of right pars triangularis, but not pars opercularis, improves naming in aphasia

PubMed Central

Naeser, Margaret A.; Martin, Paula I.; Theoret, Hugo; Kobayashi, Masahito; Fregni, Felipe; Nicholas, Marjorie; Tormos, Jose M.; Steven, Megan S.; Baker, Errol H.; Pascual-Leone, Alvaro

2011-01-01

This study sought to discover if an optimum 1 cm2 area in the non-damaged right hemisphere (RH) was present, which could temporarily improve naming in chronic, nonfluent aphasia patients when suppressed with repetitive transcranial magnetic stimulation (rTMS). Ten minutes of slow, 1 Hz rTMS was applied to suppress different RH ROIs in eight aphasia cases. Picture naming and response time (RT) were examined before, and immediately after rTMS. In aphasia patients, suppression of right pars triangularis (PTr) led to significant increase in pictures named, and significant decrease in RT. Suppression of right pars opercularis (POp), however, led to significant increase in RT, but no change in number of pictures named. Eight normals named all pictures correctly; similar to aphasia patients, RT significantly decreased following rTMS to suppress right PTr, versus right POp. Differential effects following suppression of right PTr versus right POp suggest different functional roles for these regions. PMID:21864891

[What is the purpose of the German Aptitude Test for Medical Studies (TMS)?].

PubMed

Kadmon, Guni; Kirchner, Anna; Duelli, Roman; Resch, Franz; Kadmon, Martina

2012-01-01

The German Aptitude Test for Medical Studies (TMS) was implemented in 2007. 12,194 persons registered for this test in 2011, which represents a 91% increase over 2007. The male/female ratio remained constant at 38:62. Its reliability among applicants to Heidelberg Medical Faculty was confirmed by Cronbach's α (≥ 0.75) and inter-item correlation (≥ 0.25, p < 10(-7)). The TMS contains nine items; using factor analysis these were allocated to the two components verbal-mathematical and spatial-figural ability. The verbal-mathematical items moderately correlate with the German Baccalaureate GPA (r = 0.33), while the spatial-figural items do not correlate (r = 0.07). Thus, the TMS is an admission instrument that appraise different cognitive abilities than the GPA. For the admission of students to our faculty their TMS scores are weighted at 39%, which has resulted in a diversification of our student cohorts. Copyright © 2011. Published by Elsevier GmbH.

Integration of piezo-capacitive and piezo-electric nanoweb based pressure sensors for imaging of static and dynamic pressure distribution.

PubMed

Jeong, Y J; Oh, T I; Woo, E J; Kim, K J

2017-07-01

Recently, highly flexible and soft pressure distribution imaging sensor is in great demand for tactile sensing, gait analysis, ubiquitous life-care based on activity recognition, and therapeutics. In this study, we integrate the piezo-capacitive and piezo-electric nanowebs with the conductive fabric sheets for detecting static and dynamic pressure distributions on a large sensing area. Electrical impedance tomography (EIT) and electric source imaging are applied for reconstructing pressure distribution images from measured current-voltage data on the boundary of the hybrid fabric sensor. We evaluated the piezo-capacitive nanoweb sensor, piezo-electric nanoweb sensor, and hybrid fabric sensor. The results show the feasibility of static and dynamic pressure distribution imaging from the boundary measurements of the fabric sensors.

TMS communications software. Volume 1: Computer interfaces

NASA Technical Reports Server (NTRS)

Brown, J. S.; Lenker, M. D.

1979-01-01

A prototype bus communications system, which is being used to support the Trend Monitoring System (TMS) as well as for evaluation of the bus concept is considered. Hardware and software interfaces to the MODCOMP and NOVA minicomputers are included. The system software required to drive the interfaces in each TMS computer is described. Documentation of other software for bus statistics monitoring and for transferring files across the bus is also included.

Reflections of a TMS International Scholar: Sharing Research across Cultures and Continents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unocic, Kinga A.

Here, I was honored to be selected as the 2017 Japan Institute of Metals (JIM)/TMS Young Leaders International Scholar, an opportunity made possible by the TMS Foundation. One of the benefits of receiving this award for me was traveling to Japan to visit the National Institute for Materials Science (NIMS), and attending the 2017 JIM Annual Spring Meeting, held at the Tokyo Metropolitan University.

Dissociating Contributions of the Motor Cortex to Speech Perception and Response Bias by Using Transcranial Magnetic Stimulation

PubMed Central

Smalle, Eleonore H. M.; Rogers, Jack; Möttönen, Riikka

2015-01-01

Recent studies using repetitive transcranial magnetic stimulation (TMS) have demonstrated that disruptions of the articulatory motor cortex impair performance in demanding speech perception tasks. These findings have been interpreted as support for the idea that the motor cortex is critically involved in speech perception. However, the validity of this interpretation has been called into question, because it is unknown whether the TMS-induced disruptions in the motor cortex affect speech perception or rather response bias. In the present TMS study, we addressed this question by using signal detection theory to calculate sensitivity (i.e., d′) and response bias (i.e., criterion c). We used repetitive TMS to temporarily disrupt the lip or hand representation in the left motor cortex. Participants discriminated pairs of sounds from a “ba”–“da” continuum before TMS, immediately after TMS (i.e., during the period of motor disruption), and after a 30-min break. We found that the sensitivity for between-category pairs was reduced during the disruption of the lip representation. In contrast, disruption of the hand representation temporarily reduced response bias. This double dissociation indicates that the hand motor cortex contributes to response bias during demanding discrimination tasks, whereas the articulatory motor cortex contributes to perception of speech sounds. PMID:25274987

Transcranial magnetic and electrical stimulation compared: does TES activate intracortical neuronal circuits?

PubMed

Brocke, J; Irlbacher, K; Hauptmann, B; Voss, M; Brandt, S A

2005-12-01

To determine whether, and under which conditions, transcranial electrical stimulation (TES) and transcranial magnetic stimulation (TMS) can activate similar neuronal structures of the human motor cortex, as indicated by electromyographic recordings. Focal TMS was performed on three subjects inducing a postero-anterior directed current (p-a), TES with postero-anteriorly (p-a) and latero-medially (l-m) oriented electrodes. We analyzed the onset latencies and amplitudes (single-pulse) and intracortical inhibition and excitation (paired-pulse). TMS p-a and TES p-a produced muscle responses with the same onset latency, while TES l-m led to 1.4-1.9 ms shorter latencies. Paired-pulse TMS p-a and TES p-a induced inhibition at short inter-stimulus intervals (ISI) (maximum: 2-3 ms) and facilitation at longer ISIs (maximum: 10 ms). No inhibition but a strong facilitation was obtained from paired-pulse TES l-m (ISIs 1-5 ms). Our findings support the hypothesis, that current direction is the most relevant factor in determining the mode of activation for both TMS and TES: TMS p-a and TES p-a are likely to activate the corticospinal neurons indirectly. In contrast, TES l-m may preferentially activate the corticospinal fibres directly, distant of the neuronal body. TES is a suitable tool to induce intracortical inhibition and excitation.

Measurement of δ13C values of soil amino acids by GC-C-IRMS using trimethylsilylation: a critical assessment.

PubMed

Rubino, Mauro; Milin, Sylvie; D'Onofrio, Antonio; Signoret, Patrick; Hatté, Christine; Balesdent, Jérôme

2014-01-01

In this study, we evaluated trimethylsilyl (TMS) derivatives as derivatization reagents for the compound-specific stable carbon isotope analysis of soil amino acids by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). We used non-proteinogenic amino acids to show that the extraction-derivatization-analysis procedure provides a reliable method to measure δ(13)C values of amino acids extracted from soil. However, we found a number of drawbacks that significantly increase the final total uncertainty. These include the following: production of multiple peaks for each amino acid, identified as di-, tri- and tetra-TMS derivatives; a number of TMS-carbon (TMS-C) atoms added lower than the stoichiometric one, possibly due to incomplete combustion; different TMS-C δ(13)C for di-, tri- and tetra-TMS derivatives. For soil samples, only four amino acids (leucine, valine, threonine and serine) provide reliable δ(13)C values with a total average uncertainty of 1.3 ‰. We conclude that trimethylsilyl derivatives are only suitable for determining the (13)C incorporation in amino acids within experiments using (13)C-labelled tracers but cannot be applied for amino acids with natural carbon isotope abundance until the drawbacks described here are overcome and the measured total uncertainty significantly decreased.

Dental Providers' Perspectives on Diagnosis-Driven Dentistry: Strategies to Enhance Adoption of Dental Diagnostic Terminology.

PubMed

Obadan-Udoh, Enihomo; Simon, Lisa; Etolue, Jini; Tokede, Oluwabunmi; White, Joel; Spallek, Heiko; Walji, Muhammad; Kalenderian, Elsbeth

2017-07-13

The routine use of standardized diagnostic terminologies (DxTMs) in dentistry has long been the subject of academic debate. This paper discusses the strategies suggested by a group of dental stakeholders to enhance the uptake of DxTMs. Through unstructured interviewing at the 'Toward a Diagnosis-Driven Profession' National Conference held on 19 March 2016 in Los Angeles, CA, USA participants were asked how enthusiastic they were about implementing and consistently using DxTMs at their work. They also brainstormed on strategies to improve the widespread use of DxTMs. Their responses are summarized by recursive abstraction and presented in themes. Conference participants were very enthusiastic about using a DxTM in their place of work. Participants enumerated several strategies to make DxTMs more appealing including: the use of mandates, a value proposition for providers, communication and education, and integration with EHRs and existing systems. All groups across the dental healthcare delivery spectrum will need to work together for the success of the widespread and consistent use of DxTMs. Understanding the provider perspective is however the most critical step in achieving this goal, as they are the group who will ultimately be saddled with the critical task of ensuring DxTM use at the point of care.

Dental Providers’ Perspectives on Diagnosis-Driven Dentistry: Strategies to Enhance Adoption of Dental Diagnostic Terminology

PubMed Central

Obadan-Udoh, Enihomo; Etolue, Jini; Tokede, Oluwabunmi; White, Joel; Spallek, Heiko; Walji, Muhammad; Kalenderian, Elsbeth

2017-01-01

The routine use of standardized diagnostic terminologies (DxTMs) in dentistry has long been the subject of academic debate. This paper discusses the strategies suggested by a group of dental stakeholders to enhance the uptake of DxTMs. Through unstructured interviewing at the ‘Toward a Diagnosis-Driven Profession’ National Conference held on 19 March 2016 in Los Angeles, CA, USA participants were asked how enthusiastic they were about implementing and consistently using DxTMs at their work. They also brainstormed on strategies to improve the widespread use of DxTMs. Their responses are summarized by recursive abstraction and presented in themes. Conference participants were very enthusiastic about using a DxTM in their place of work. Participants enumerated several strategies to make DxTMs more appealing including: the use of mandates, a value proposition for providers, communication and education, and integration with EHRs and existing systems. All groups across the dental healthcare delivery spectrum will need to work together for the success of the widespread and consistent use of DxTMs. Understanding the provider perspective is however the most critical step in achieving this goal, as they are the group who will ultimately be saddled with the critical task of ensuring DxTM use at the point of care. PMID:28703751

The Origin of Word-related Motor Activity

PubMed Central

Papeo, Liuba; Lingnau, Angelika; Agosta, Sara; Pascual-Leone, Alvaro; Battelli, Lorella; Caramazza, Alfonso

2015-01-01

Conceptual processing of verbs consistently recruits the left posterior middle temporal gyrus (lpMTG). The left precentral motor cortex also responds to verbs, with higher activity for action than nonaction verbs. The early timing of this effect has suggested that motor features of words' meaning are accessed directly, bypassing access to conceptual representations in lpMTG. An alternative hypothesis is that the retrieval of conceptual representations in lpMTG is necessary to drive more specific, motor-related representations in the precentral gyrus. To test these hypotheses, we first showed that repetitive transcranial magnetic stimulation (rTMS) applied to the verb-preferring lpMTG site selectively impoverished the semantic processing of verbs. In a second experiment, rTMS perturbation of lpMTG, relative to no stimulation (no-rTMS), eliminated the action–nonaction verb distinction in motor activity, as indexed by motor-evoked potentials induced in peripheral muscles with single-pulse TMS over the left primary motor cortex. rTMS pertubation of an occipital control site, relative to no-rTMS, did not affect the action–nonaction verb distinction in motor activity, but the verb contrast did not differ reliably from the lpMTG effect. The results show that lpMTG carries core semantic information necessary to drive the activation of specific (motor) features in the precentral gyrus. PMID:24421174

Automatized set-up procedure for transcranial magnetic stimulation protocols.

PubMed

Harquel, S; Diard, J; Raffin, E; Passera, B; Dall'Igna, G; Marendaz, C; David, O; Chauvin, A

2017-06-01

Transcranial Magnetic Stimulation (TMS) established itself as a powerful technique for probing and treating the human brain. Major technological evolutions, such as neuronavigation and robotized systems, have continuously increased the spatial reliability and reproducibility of TMS, by minimizing the influence of human and experimental factors. However, there is still a lack of efficient set-up procedure, which prevents the automation of TMS protocols. For example, the set-up procedure for defining the stimulation intensity specific to each subject is classically done manually by experienced practitioners, by assessing the motor cortical excitability level over the motor hotspot (HS) of a targeted muscle. This is time-consuming and introduces experimental variability. Therefore, we developed a probabilistic Bayesian model (AutoHS) that automatically identifies the HS position. Using virtual and real experiments, we compared the efficacy of the manual and automated procedures. AutoHS appeared to be more reproducible, faster, and at least as reliable as classical manual procedures. By combining AutoHS with robotized TMS and automated motor threshold estimation methods, our approach constitutes the first fully automated set-up procedure for TMS protocols. The use of this procedure decreases inter-experimenter variability while facilitating the handling of TMS protocols used for research and clinical routine. Copyright © 2017 Elsevier Inc. All rights reserved.

Why bistetracenes are much less reactive than pentacenes in Diels-Alder reactions with fullerenes.

PubMed

Cao, Yang; Liang, Yong; Zhang, Lei; Osuna, Sílvia; Hoyt, Andra-Lisa M; Briseno, Alejandro L; Houk, K N

2014-07-30

The Diels-Alder (DA) reactions of pentacene (PT), 6,13-bis(2-trimethylsilylethynyl)pentacene (TMS-PT), bistetracene (BT), and 8,17-bis(2-trimethylsilylethynyl)bistetracene (TMS-BT) with the [6,6] double bond of [60]fullerene have been investigated by density functional theory calculations. Reaction barriers and free energies have been obtained to assess the effects of frameworks and substituent groups on the DA reactivity and product stability. Calculations indicate that TMS-BT is about 5 orders of magnitude less reactive than TMS-PT in the reactions with [60]fullerene. This accounts for the observed much higher stability of TIPS-BT than TIPS-PT when mixed with PCBM. Surprisingly, calculations predict that the bulky silylethynyl substituents of TMS-PT and TMS-BT have only a small influence on reaction barriers. However, the silylethynyl substituents significantly destabilize the corresponding products due to steric repulsions in the adducts. This is confirmed by experimental results here. Architectures of the polycyclic aromatic hydrocarbons (PAHs) play a crucial role in determining both the DA barrier and the adduct stability. The reactivities of different sites in various PAHs are related to the loss of aromaticity, which can be predicted using the simple Hückel molecular orbital localization energy calculations.

Topographic contribution of early visual cortex to short-term memory consolidation: a transcranial magnetic stimulation study.

PubMed

van de Ven, Vincent; Jacobs, Christianne; Sack, Alexander T

2012-01-04

The neural correlates for retention of visual information in visual short-term memory are considered separate from those of sensory encoding. However, recent findings suggest that sensory areas may play a role also in short-term memory. We investigated the functional relevance, spatial specificity, and temporal characteristics of human early visual cortex in the consolidation of capacity-limited topographic visual memory using transcranial magnetic stimulation (TMS). Topographically specific TMS pulses were delivered over lateralized occipital cortex at 100, 200, or 400 ms into the retention phase of a modified change detection task with low or high memory loads. For the high but not the low memory load, we found decreased memory performance for memory trials in the visual field contralateral, but not ipsilateral to the side of TMS, when pulses were delivered at 200 ms into the retention interval. A behavioral version of the TMS experiment, in which a distractor stimulus (memory mask) replaced the TMS pulses, further corroborated these findings. Our findings suggest that retinotopic visual cortex contributes to the short-term consolidation of topographic visual memory during early stages of the retention of visual information. Further, TMS-induced interference decreased the strength (amplitude) of the memory representation, which most strongly affected the high memory load trials.

Electric field-navigated transcranial magnetic stimulation for chronic tinnitus: a randomized, placebo-controlled study.

PubMed

Sahlsten, Hanna; Virtanen, Juuso; Joutsa, Juho; Niinivirta-Joutsa, Katri; Löyttyniemi, Eliisa; Johansson, Reijo; Paavola, Janika; Taiminen, Tero; Sjösten, Noora; Salonen, Jaakko; Holm, Anu; Rauhala, Esa; Jääskeläinen, Satu K

2017-09-01

Repetitive transcranial magnetic stimulation (rTMS) may alleviate tinnitus. We evaluated effects of electric field (E-field) navigated rTMS targeted according to tinnitus pitch. No controlled studies have investigated anatomically accurate E-field-rTMS for tinnitus. Effects of E-field-rTMS were evaluated in a prospective randomised placebo-controlled 6-month follow-up study on parallel groups. Patients received 10 sessions of 1 Hz rTMS or placebo targeted to the left auditory cortex corresponding to tonotopic representation of tinnitus pitch. Effects were evaluated immediately after treatment and at 1, 3 and 6 months. Primary outcome measures were visual analogue scores (VAS 0-100) for tinnitus intensity, annoyance and distress, and the Tinnitus Handicap Inventory (THI). Thirty-nine patients (mean age 50.3 years). The mean tinnitus intensity (F 3  = 15.7, p < 0.0001), annoyance (F 3  = 8.8, p = 0.0002), distress (F 3  = 9.1, p = 0.0002) and THI scores (F 4  = 13.8, p < 0.0001) decreased in both groups over time with non-significant differences between the groups. After active rTMS, 42% and 37% of the patients showed excellent response at 1 and 3 months against 15% and 10% in the placebo group (p = 0.082 and p = 0.065). Despite the significant effects of rTMS on tinnitus, differences between active and placebo groups remained non-significant, due to large placebo-effect and wide inter-individual variation.

In silico database screening of potential targets and pathways of compounds contained in plants used for psoriasis vulgaris.

PubMed

May, Brian H; Deng, Shiqiang; Zhang, Anthony L; Lu, Chuanjian; Xue, Charlie C L

2015-09-01

Reviews and meta-analyses of clinical trials identified plants used as traditional medicines (TMs) that show promise for psoriasis. These include Rehmannia glutinosa, Camptotheca acuminata, Indigo naturalis and Salvia miltiorrhiza. Compounds contained in these TMs have shown activities of relevance to psoriasis in experimental models. To further investigate the likely mechanisms of action of the multiple compounds in these TMs, we undertook a computer-based in silico investigation of the proteins known to be regulated by these compounds and their associated biological pathways. The proteins reportedly regulated by compounds in these four TMs were identified using the HIT (Herbal Ingredients' Targets) database. The resultant data were entered into the PANTHER (Protein ANnotation THrough Evolutionary Relationship) database to identify the pathways in which the proteins could be involved. The study identified 237 compounds in the TMs and these retrieved 287 proteins from HIT. These proteins identified 59 pathways in PANTHER with most proteins being located in the Apoptosis, Angiogenesis, Inflammation mediated by chemokine and cytokine, Gonadotropin releasing hormone receptor, and/or Interleukin signaling pathways. All four TMs contained compounds that had regulating effects on Apoptosis regulator BAX, Apoptosis regulator Bcl-2, Caspase-3, Tumor necrosis factor (TNF) or Prostaglandin G/H synthase 2 (COX2). The main proteins and pathways are primarily related to inflammation, proliferation and angiogenesis which are all processes involved in psoriasis. Experimental studies have reported that certain compounds from these TMs can regulate the expression of proteins involved in each of these pathways.

Accelerometer-based automatic voice onset detection in speech mapping with navigated repetitive transcranial magnetic stimulation.

PubMed

Vitikainen, Anne-Mari; Mäkelä, Elina; Lioumis, Pantelis; Jousmäki, Veikko; Mäkelä, Jyrki P

2015-09-30

The use of navigated repetitive transcranial magnetic stimulation (rTMS) in mapping of speech-related brain areas has recently shown to be useful in preoperative workflow of epilepsy and tumor patients. However, substantial inter- and intraobserver variability and non-optimal replicability of the rTMS results have been reported, and a need for additional development of the methodology is recognized. In TMS motor cortex mappings the evoked responses can be quantitatively monitored by electromyographic recordings; however, no such easily available setup exists for speech mappings. We present an accelerometer-based setup for detection of vocalization-related larynx vibrations combined with an automatic routine for voice onset detection for rTMS speech mapping applying naming. The results produced by the automatic routine were compared with the manually reviewed video-recordings. The new method was applied in the routine navigated rTMS speech mapping for 12 consecutive patients during preoperative workup for epilepsy or tumor surgery. The automatic routine correctly detected 96% of the voice onsets, resulting in 96% sensitivity and 71% specificity. Majority (63%) of the misdetections were related to visible throat movements, extra voices before the response, or delayed naming of the previous stimuli. The no-response errors were correctly detected in 88% of events. The proposed setup for automatic detection of voice onsets provides quantitative additional data for analysis of the rTMS-induced speech response modifications. The objectively defined speech response latencies increase the repeatability, reliability and stratification of the rTMS results. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of Transcranial Magnetic Stimulation and Electroneuronography Between Bell's Palsy and Ramsay Hunt Syndrome in Their Acute Stages

PubMed Central

Hur, Dong Min; Lee, Young Hee; Kim, Sung Hoon; Park, Jung Mi; Kim, Ji Hyun; Yong, Sang Yeol; Shinn, Jong Mock; Oh, Kyung Joon

2013-01-01

Objective To examine the neurophysiologic status in patients with idiopathic facial nerve palsy (Bell's palsy) and Ramsay Hunt syndrome (herpes zoster oticus) within 7 days from onset of symptoms, by comparing the amplitude of compound muscle action potentials (CMAP) of facial muscles in electroneuronography (ENoG) and transcranial magnetic stimulation (TMS). Methods The facial nerve conduction study using ENoG and TMS was performed in 42 patients with Bell's palsy and 14 patients with Ramsay Hunt syndrome within 7 days from onset of symptoms. Denervation ratio was calculated as CMAP amplitude evoked by ENoG or TMS on the affected side as percentage of the amplitudes on the healthy side. The severity of the facial palsy was graded according to House-Brackmann facial grading scale (H-B FGS). Results In all subjects, the denervation ratio in TMS (71.53±18.38%) was significantly greater than the denervation ratio in ENoG (41.95±21.59%). The difference of denervation ratio between ENoG and TMS was significantly smaller in patients with Ramsay Hunt syndrome than in patients with Bell's palsy. The denervation ratio of ENoG or TMS did not correlated significantly with the H-B FGS. Conclusion In the electrophysiologic study for evaluation in patients with facial palsy within 7 days from onset of symptoms, ENoG and TMS are useful in gaining additional information about the neurophysiologic status of the facial nerve and may help to evaluate prognosis and set management plan. PMID:23525840

Repetitive Transcranial Magnetic Stimulation (rTMS) to Treat Social Anxiety Disorder: Case Reports and a Review of the Literature

PubMed Central

Paes, Flávia; Baczynski, Tathiana; Novaes, Felipe; Marinho, Tamires; Arias-Carrión, Oscar; Budde, Henning; Sack, Alexander T.; Huston, Joseph P.; Almada, Leonardo Ferreira; Carta, Mauro; Silva, Adriana Cardoso; Nardi, Antonio E.; Machado, Sergio

2013-01-01

Objectives: Social anxiety disorder (SAD) is a common and debilitating anxiety disorders. However, few studies had been dedicated to the neurobiology underlying SAD until the last decade. Rates of non-responders to standard methods of treatment remain unsatisfactorily high of approximately 25%, including SAD. Advances in our understanding of SAD could lead to new treatment strategies. A potential non invasive therapeutic option is repetitive transcranial magnetic stimulation (rTMS). Thus, we reported two cases of SAD treated with rTMS Methods: The bibliographical search used Pubmed/Medline, ISI Web of Knowledge and Scielo databases. The terms chosen for the search were: anxiety disorders, neuroimaging, repetitive transcranial magnetic stimulation. Results: In most of the studies conducted on anxiety disorders, except SAD, the right prefrontal cortex (PFC), more specifically dorsolateral PFC was stimulated, with marked results when applying high-rTMS compared with studies stimulating the opposite side. However, according to the “valence hypothesis”, anxiety disorders might be characterized by an interhemispheric imbalance associated with increased right-hemispheric activity. With regard to the two cases treated with rTMS, we found a decrease in BDI, BAI and LSAS scores from baseline to follow-up. Conclusion: We hypothesize that the application of low-rTMS over the right medial PFC (mPFC; the main structure involved in SAD circuitry) combined with high-rTMS over the left mPFC, for at least 4 weeks on consecutive weekdays, may induce a balance in brain activity, opening an attractive therapeutic option for the treatment of SAD. PMID:24278088

Default Mode Network Mechanisms of Transcranial Magnetic Stimulation in Depression

PubMed Central

Liston, Conor; Chen, Ashley C.; Zebley, Benjamin D.; Drysdale, Andrew T.; Gordon, Rebecca; Leuchter, Bruce; Voss, Henning U.; Casey, B.J.; Etkin, Amit; Dubin, Marc J.

2014-01-01

Background Repetitive transcranial magnetic stimulation (TMS) of the dorsolateral prefrontal cortex (DLPFC) is an established treatment for depression, but its underlying mechanism of action remains unknown. Abnormalities in two large-scale neuronal networks—the frontoparietal central executive network (CEN) and the medial prefrontal-medial parietal default mode network (DMN)—are consistent findings in depression and potential therapeutic targets for TMS. Here, we assessed the impact of TMS on activity in these networks and their relation to treatment response. Methods We used resting state functional magnetic resonance imaging (rs-fMRI) to measure functional connectivity within and between the DMN and CEN in 17 depressed patients, before and after a five-week course of TMS. Motivated by prior reports, we focused on connectivity seeded from the DLPFC and the subgenual cingulate, a key region closely aligned with the DMN in depression. Connectivity was also compared to a cohort of 35 healthy controls. Results Prior to treatment, functional connectivity in depressed patients was abnormally elevated within the DMN and diminished within the CEN, and connectivity between these two networks was altered. TMS normalized depression-related subgenual hyperconnectivity in the DMN but did not alter connectivity in the CEN. TMS also induced anticorrelated connectivity between the DLPFC and medial prefrontal DMN nodes. Baseline subgenual connectivity predicted subsequent clinical improvement. Conclusions TMS selectively modulates functional connectivity both within and between the CEN and DMN, and modulation of subgenual cingulate connectivity may play an important mechanistic role in alleviating depression. The results also highlight potential neuroimaging biomarkers for predicting treatment response. PMID:24629537

On the functional role of human parietal cortex in number processing: How gender mediates the impact of a 'virtual lesion' induced by rTMS.

PubMed

Knops, Andre; Nuerk, Hans-Christoph; Sparing, Roland; Foltys, Henrik; Willmes, Klaus

2006-01-01

Areas around the horizontal part of the intraparietal sulcus (hIPS) have repeatedly been reported to participate in processing numerical magnitude. Using transcranial magnetic stimulation (TMS), we investigated the functional role of the hIPS by examining two effects from the domain of numerical cognition: in magnitude comparison tasks response latencies are inversely related to the numerical distance between two numbers. This distance effect indexes access to the mental number representation. In magnitude comparison tasks responses are faster when decade and unit comparison would lead to the same decision (e.g. 42_57, 4 < 5 and 2 < 7) than when they would not (e.g. 47_62, 4 < 6 but 7 > 2). This compatibility effect reflects unit-decade integration processes. Differential susceptibility of (fe)male participants to TMS was examined. We applied repetitive TMS (rTMS; 1Hz for 10 min) over the left hIPS in 12 participants (6 female). No stimulation and vertex stimulation served as control conditions. The effect of rTMS was mediated by gender: in male participants, the distance effect decreased after TMS over hIPS. For female participants distance and compatibility effect both increased. This modulation of the compatibility effect was limited in duration to no more than 4 min. The hIPS seems to be functionally involved both in number magnitude processing and in integrating unit-decade magnitude information of two-digit numbers. Relative hemispheric specialization of the hIPS with respect to two-digit magnitude comparison is discussed.

Cost-effectiveness of electroconvulsive therapy compared to repetitive transcranial magnetic stimulation for treatment-resistant severe depression: a decision model.

PubMed

Vallejo-Torres, L; Castilla, I; González, N; Hunter, R; Serrano-Pérez, P; Perestelo-Pérez, L

2015-05-01

Electroconvulsive therapy (ECT) is widely applied to treat severe depression resistant to standard treatment. Results from previous studies comparing the cost-effectiveness of this technique with treatment alternatives such as repetitive transcranial magnetic stimulation (rTMS) are conflicting. We conducted a cost-effectiveness analysis comparing ECT alone, rTMS alone and rTMS followed by ECT when rTMS fails under the perspective of the Spanish National Health Service. The analysis is based on a Markov model which simulates the costs and health outcomes of individuals treated under these alternatives over a 12-month period. Data to populate this model were extracted and synthesized from a series of randomized controlled trials and other studies that have compared these techniques on the patient group of interest. We measure effectiveness using quality-adjusted life years (QALYs) and characterize the uncertainty using probabilistic sensitivity analyses. ECT alone was found to be less costly and more effective than rTMS alone, while the strategy of providing rTMS followed by ECT when rTMS fails is the most expensive and effective option. The incremental cost per QALY gained of this latter strategy was found to be above the reference willingness-to-pay threshold used in these types of studies in Spain and other countries. The probability that ECT alone is the most cost-effective alternative was estimated to be around 70%. ECT is likely to be the most cost-effective option in the treatment of resistant severe depression for a willingness to pay of €30,000 per QALY.

Repetitive Transcranial Magnetic Stimulation for the Treatment of Executive Function Deficits in Autism Spectrum Disorder: Clinical Trial Approach.

PubMed

Ameis, Stephanie H; Daskalakis, Zafiris J; Blumberger, Daniel M; Desarkar, Pushpal; Drmic, Irene; Mabbott, Donald J; Lai, Meng-Chuan; Croarkin, Paul E; Szatmari, Peter

2017-06-01

Executive function (EF) deficits in patients with autism spectrum disorder (ASD) are ubiquitous and understudied. Further, there are no effective, neuroscience-based treatments to address this impairing feature of ASD. Repetitive transcranial magnetic stimulation (rTMS) has demonstrated promise in addressing EF deficits in adult neuropsychiatric disorders. This article will outline the design of a novel randomized-controlled trial of bilateral, 20 Hz, rTMS applied to the dorsolateral prefrontal cortex (DLPFC) for treatment of EF deficits in ASD that is currently ongoing. We describe prior therapeutic rTMS research for ASD and prior rTMS trials targeting EFs in adult neuropsychiatric disorders. A neurophysiological rationale for rTMS treatment of EF deficits in ASD is presented. An ongoing protocol will enroll participants aged 16-35 with ASD and no intellectual disability. Psychotropic medications will be continued during the 4-week trial of active 20 Hz versus sham rTMS applied to the DLPFC. Twenty, active treatment sessions consisting of 25 stimulation trains at a 90% motor threshold will be administered. The primary outcome measure is the Cambridge Neuropsychological Test Automated Battery (CANTAB) spatial working memory task. At present, recruitment, enrollment, and treatment within the described clinical trial are ongoing. EF deficits are common and impairing symptoms of ASD. There are no evidence-based treatments for EF deficits in ASD. The protocol described here will provide important preliminary data on the feasibility and efficacy of 20 Hz rTMS to DLPFC for EF deficits in ASD.

Age-related differences in short- and long-interval intracortical inhibition in a human hand muscle.

PubMed

Opie, George M; Semmler, John G

2014-01-01

Effects of age on the assessment of intracortical inhibition with paired-pulse transcranial magnetic stimulation (TMS) have been variable, which may be due to between-study differences in test TMS intensity and test motor evoked potential (MEP) amplitude. To investigate age-related differences in short- (SICI) and long-interval intracortical inhibition (LICI) across a range of test TMS intensities and test MEP amplitudes. In 22 young and 18 older subjects, SICI and LICI were recorded at a range of test TMS intensities (110%-150% of motor threshold) while the first dorsal interosseous (FDI) muscle was at rest, or producing a precision grip of the index finger and thumb. Data were subsequently compared according to the amplitude of the MEP produced by the test alone TMS. When pooled across all test TMS intensities, SICI in resting muscle and LICI in active muscle were similar in young and older adults, whereas SICI in active muscle and LICI in resting muscle were reduced in older adults. Regrouping data based on test MEP amplitude demonstrated similar effects of age for SICI and LICI in resting muscle, whereas more subtle differences between age groups were revealed for SICI and LICI in active muscle. Advancing age influences GABA-mediated intracortical inhibition, but the outcome is dependent on the experimental conditions. Age-related differences in SICI and LICI were influenced by test TMS intensity and test MEP amplitude, suggesting that these are important considerations when assessing intracortical inhibition in older adults, particularly in an active muscle. Copyright © 2014 Elsevier Inc. All rights reserved.

Electrophysiological correlates of stimulus-driven reorienting deficits after interference with right parietal cortex during a spatial attention task: a TMS-EEG study

PubMed Central

Capotosto, Paolo; Corbetta, Maurizio; Romani, Gian Luca; Babiloni, Claudio

2013-01-01

Transcranial magnetic stimulation (TMS) interference over right intraparietal sulcus (IPS) causally disrupts behaviorally and electroencephalographic (EEG) rhythmic correlates of endogenous spatial orienting prior to visual target presentation (Capotosto et al. 2009; 2011). Here we combine data from our previous studies to examine whether right parietal TMS during spatial orienting also impairs stimulus-driven re-orienting or the ability to efficiently process unattended stimuli, i.e. stimuli outside the current focus of attention. Healthy subjects (N=24) performed a Posner spatial cueing task while their EEG activity was being monitored. Repetitive TMS (rTMS) was applied for 150 milliseconds (ms) simultaneously to the presentation of a central arrow directing spatial attention to the location of an upcoming visual target. Right IPS-rTMS impaired target detection, especially for stimuli presented at unattended locations; it also caused a modulation of the amplitude of parieto-occipital positive ERPs peaking at about 480 ms (P3) post-target. The P3 significantly decreased for unattended targets, and significantly increased for attended targets after right IPS-rTMS as compared to Sham stimulation. Similar effects were obtained for left IPS stimulation albeit in a smaller group of subjects. We conclude that disruption of anticipatory processes in right IPS has prolonged effects that persist during target processing. The P3 decrement may reflect interference with post-decision processes that are part of stimulus-driven re-orienting. Right IPS is a node of functional interaction between endogenous spatial orienting and stimulus-driven re-orienting processes in human vision. PMID:22905824

Effects of cerebellar neuromodulation in movement disorders: A systematic review.

PubMed

França, Carina; de Andrade, Daniel Ciampi; Teixeira, Manoel Jacobsen; Galhardoni, Ricardo; Silva, Valquiria; Barbosa, Egberto Reis; Cury, Rubens Gisbert

The cerebellum is involved in the pathophysiology of many movement disorders and its importance in the field of neuromodulation is growing. To review the current evidence for cerebellar modulation in movement disorders and its safety profile. Eligible studies were identified after a systematic literature review of the effects of cerebellar modulation in cerebellar ataxia, Parkinson's disease (PD), essential tremor (ET), dystonia and progressive supranuclear palsy (PSP). Neuromodulation techniques included transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS) and deep brain stimulation (DBS). The changes in motor scores and the incidence of adverse events after the stimulation were reviewed. Thirty-four studies were included in the systematic review, comprising 431 patients. The evaluation after stimulation ranged from immediately after to 12 months after. Neuromodulation techniques improved cerebellar ataxia due to vascular or degenerative etiologies (TMS, tDCS and DBS), dyskinesias in PD patients (TMS), gross upper limb movement in PD patients (tDCS), tremor in ET (TMS and tDCS), cervical dystonia (TMS and tDCS) and dysarthria in PSP patients (TMS). All the neuromodulation techniques were safe, since only three studies reported the existence of side effects (slight headache after TMS, local skin erythema after tDCS and infectious complication after DBS). Eleven studies did not mention if adverse events occurred. Cerebellar modulation can improve specific symptoms in some movement disorders and is a safe and well-tolerated procedure. Further studies are needed to lay the groundwork for new researches in this promising target. Copyright © 2017 Elsevier Inc. All rights reserved.

Local Immediate versus Long-Range Delayed Changes in Functional Connectivity Following rTMS on the Visual Attention Network.

PubMed

Battelli, Lorella; Grossman, Emily D; Plow, Ela B

The interhemispheric competition hypothesis attributes the distribution of selective attention to a balance of mutual inhibition between homotopic, interhemispheric connections in parietal cortex (Kinsbourne 1977; Battelli et al., 2009). In support of this hypothesis, repetitive inhibitory TMS over right parietal cortex in healthy individuals rapidly induces interhemispheric imbalance in cortical activity that spreads beyond the site of stimulation (Plow et al., 2014). Behaviorally, the impacts of inhibitory rTMS may be long delayed from the onset of stimulation, as much as 30 minutes (Agosta et al., 2014; Hubl et al., 2008). In this study, we examine the temporal dynamics of inhibitory rTMS on cortical network integrity that supports sustained visual attention. Healthy individuals received 15 min of 1 Hz offline, inhibitory rTMS (or sham) over left parietal cortex, and then immediately engaged in a bilateral visual tracking task while we recorded brain activity with fMRI. We computed functional connectivity (FC) between three nodes of the attention network engaged by visual tracking: the intraparietal sulcus (IPS), frontal eye fields (FEF) and human MT+ (hMT+). FC immediately and significantly decreased between the stimulation site (left IPS) and all other regions, then recovered to normal levels within 30 minutes. rTMS increased FC between left and right FEF at approximately 36 min following stimulation, and between sites in the unstimulated hemisphere approximately 48 min after stimulation. These findings demonstrate large-scale changes in cortical organization following inhibitory rTMS. The immediate impact of rTMS on connectivity to the stimulation site dovetails with the putative role of interhemispheric balance for bilateral visual sustained attention. The delayed, compensatory increases in functional connectivity have implications for models of dynamic reorganization in networks supporting spatial and nonspatial selective attention, and compensatory mechanisms within these networks that may be stabilized in chronic stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

Cost effectiveness analysis comparing repetitive transcranial magnetic stimulation to antidepressant medications after a first treatment failure for major depressive disorder in newly diagnosed patients - A lifetime analysis.

PubMed

Voigt, Jeffrey; Carpenter, Linda; Leuchter, Andrew

2017-01-01

Repetitive Transcranial Magnetic Stimulation (rTMS) commonly is used for the treatment of Major Depressive Disorder (MDD) after patients have failed to benefit from trials of multiple antidepressant medications. No analysis to date has examined the cost-effectiveness of rTMS used earlier in the course of treatment and over a patients' lifetime. We used lifetime Markov simulation modeling to compare the direct costs and quality adjusted life years (QALYs) of rTMS and medication therapy in patients with newly diagnosed MDD (ages 20-59) who had failed to benefit from one pharmacotherapy trial. Patients' life expectancies, rates of response and remission, and quality of life outcomes were derived from the literature, and treatment costs were based upon published Medicare reimbursement data. Baseline costs, aggregate per year quality of life assessments (QALYs), Monte Carlo simulation, tornado analysis, assessment of dominance, and one way sensitivity analysis were also performed. The discount rate applied was 3%. Lifetime direct treatment costs, and QALYs identified rTMS as the dominant therapy compared to antidepressant medications (i.e., lower costs with better outcomes) in all age ranges, with costs/improved QALYs ranging from $2,952/0.32 (older patients) to $11,140/0.43 (younger patients). One-way sensitivity analysis demonstrated that the model was most sensitive to the input variables of cost per rTMS session, monthly prescription drug cost, and the number of rTMS sessions per year. rTMS was identified as the dominant therapy compared to antidepressant medication trials over the life of the patient across the lifespan of adults with MDD, given current costs of treatment. These models support the use of rTMS after a single failed antidepressant medication trial versus further attempts at medication treatment in adults with MDD.

Double shroud delivery of silica precursor for reducing hexavalent chromium in welding fume.

PubMed

Wang, Jun; Kalivoda, Mark; Guan, Jianying; Theodore, Alexandros; Sharby, Jessica; Wu, Chang-Yu; Paulson, Kathleen; Es-Said, Omar

2012-01-01

The welding process yields a high concentration of nanoparticles loaded with hexavalent chromium (Cr(6+)), a known human carcinogen. Previous studies have demonstrated that using tetramethylsilane (TMS) as a shielding gas additive can significantly reduce the Cr(6+) concentration in welding fume particles. In this study, a novel insulated double shroud torch (IDST) was developed to further improve the reduction of airborne Cr(6+) concentration by separating the flows of the primary shielding gas and the TMS carrier gas. Welding fumes were collected from a welding chamber in the laboratory and from a fixed location near the welding arc in a welding facility. The Cr(6+) content was analyzed with ion chromatography and X-ray photoelectron spectroscopy (XPS). Results from the chamber sampling demonstrated that the addition of 3.2 ≈ 5.1% of TMS carrier gas to the primary shielding gas resulted in more than a 90% reduction of airborne Cr(6+) under all shielding gas flow rates. The XPS result confirmed complete elimination of Cr(6+) inside the amorphous silica shell. Adding 100 ≈ 1000 ppm of nitric oxide or carbon monoxide to the shielding gas could also reduce Cr(6+) concentrations up to 57% and 35%, respectively; however, these reducing agents created potential hazards from the release of unreacted agents. Results of the field test showed that the addition of 1.6% of TMS carrier gas to the primary shielding gas reduced Cr(6+) concentration to the limitation of detection (1.1 μg/m(3)). In a worst-case scenario, if TMS vapor leaked into the environment without decomposition and ventilation, the estimated TMS concentration in the condition of field sampling would be a maximum 5.7 ppm, still well below its flammability limit (1%). Based on a previously developed cost model, the use of TMS increases the general cost by 3.8%. No visual deterioration of weld quality caused by TMS was found, although further mechanical testing is necessary.

Cost effectiveness analysis comparing repetitive transcranial magnetic stimulation to antidepressant medications after a first treatment failure for major depressive disorder in newly diagnosed patients – A lifetime analysis

PubMed Central

2017-01-01

Objective Repetitive Transcranial Magnetic Stimulation (rTMS) commonly is used for the treatment of Major Depressive Disorder (MDD) after patients have failed to benefit from trials of multiple antidepressant medications. No analysis to date has examined the cost-effectiveness of rTMS used earlier in the course of treatment and over a patients’ lifetime. Methods We used lifetime Markov simulation modeling to compare the direct costs and quality adjusted life years (QALYs) of rTMS and medication therapy in patients with newly diagnosed MDD (ages 20–59) who had failed to benefit from one pharmacotherapy trial. Patients’ life expectancies, rates of response and remission, and quality of life outcomes were derived from the literature, and treatment costs were based upon published Medicare reimbursement data. Baseline costs, aggregate per year quality of life assessments (QALYs), Monte Carlo simulation, tornado analysis, assessment of dominance, and one way sensitivity analysis were also performed. The discount rate applied was 3%. Results Lifetime direct treatment costs, and QALYs identified rTMS as the dominant therapy compared to antidepressant medications (i.e., lower costs with better outcomes) in all age ranges, with costs/improved QALYs ranging from $2,952/0.32 (older patients) to $11,140/0.43 (younger patients). One-way sensitivity analysis demonstrated that the model was most sensitive to the input variables of cost per rTMS session, monthly prescription drug cost, and the number of rTMS sessions per year. Conclusion rTMS was identified as the dominant therapy compared to antidepressant medication trials over the life of the patient across the lifespan of adults with MDD, given current costs of treatment. These models support the use of rTMS after a single failed antidepressant medication trial versus further attempts at medication treatment in adults with MDD. PMID:29073256

Repetitive transcranial magnetic stimulation of the left premotor/dorsolateral prefrontal cortex does not have analgesic effect on central poststroke pain.

PubMed

de Oliveira, Rogério Adas Ayres; de Andrade, Daniel Ciampi; Mendonça, Melina; Barros, Rafael; Luvisoto, Tatiana; Myczkowski, Martin Luiz; Marcolin, Marco Antonio; Teixeira, Manoel Jacobsen

2014-12-01

Central poststroke pain (CPSP) is caused by an encephalic vascular lesion of the somatosensory pathways and is commonly refractory to current pharmacologic treatments. Repetitive transcranial magnetic stimulation (rTMS) of the premotor cortex/dorsolateral prefrontal cortex (PMC/DLPFC) can change thermal pain threshold toward analgesia in healthy subjects and has analgesic effects in acute postoperative pain as well as in fibromyalgia patients. However, its effect on neuropathic pain and in CPSP, in particular, has not been assessed. The aim of this prospective, double-blind, placebo-controlled study was to evaluate the analgesic effect of PMC/DLPFC rTMS in CPSP patients. Patients were randomized into 2 groups, active (a-) rTMS and sham (s-) rTMS, and were treated with 10 daily sessions of rTMS over the left PMC/DLPFC (10 Hz, 1,250 pulses/d). Outcomes were assessed at baseline, during the stimulation phase, and at 1, 2, and 4 weeks after the last stimulation. The main outcome was pain intensity changes measured by the visual analog scale on the last stimulation day compared to baseline. Interim analysis was scheduled when the first half of the patients completed the study. The study was terminated because of a significant lack of efficacy of the active arm after 21 patients completed the whole treatment and follow-up phases. rTMS of the left PMC/DLPFC did not improve pain in CPSP. The aim of this double-blind, placebo-controlled study was to evaluate the analgesic effects of rTMS to the PMC/DLPFC in CPSP patients. An interim analysis showed a consistent lack of analgesic effect, and the study was terminated. rTMS of the PMC/DLPFC is not effective in relieving CPSP. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

Modeling transcranial magnetic stimulation from the induced electric fields to the membrane potentials along tractography-based white matter fiber tracts

NASA Astrophysics Data System (ADS)

De Geeter, Nele; Dupré, Luc; Crevecoeur, Guillaume

2016-04-01

Objective. Transcranial magnetic stimulation (TMS) is a promising non-invasive tool for modulating the brain activity. Despite the widespread therapeutic and diagnostic use of TMS in neurology and psychiatry, its observed response remains hard to predict, limiting its further development and applications. Although the stimulation intensity is always maximum at the cortical surface near the coil, experiments reveal that TMS can affect deeper brain regions as well. Approach. The explanation of this spread might be found in the white matter fiber tracts, connecting cortical and subcortical structures. When applying an electric field on neurons, their membrane potential is altered. If this change is significant, more likely near the TMS coil, action potentials might be initiated and propagated along the fiber tracts towards deeper regions. In order to understand and apply TMS more effectively, it is important to capture and account for this interaction as accurately as possible. Therefore, we compute, next to the induced electric fields in the brain, the spatial distribution of the membrane potentials along the fiber tracts and its temporal dynamics. Main results. This paper introduces a computational TMS model in which electromagnetism and neurophysiology are combined. Realistic geometry and tissue anisotropy are included using magnetic resonance imaging and targeted white matter fiber tracts are traced using tractography based on diffusion tensor imaging. The position and orientation of the coil can directly be retrieved from the neuronavigation system. Incorporating these features warrants both patient- and case-specific results. Significance. The presented model gives insight in the activity propagation through the brain and can therefore explain the observed clinical responses to TMS and their inter- and/or intra-subject variability. We aspire to advance towards an accurate, flexible and personalized TMS model that helps to understand stimulation in the connected brain and to target more focused and deeper brain regions.

Computational and experimental analysis of TMS-induced electric field vectors critical to neuronal activation

NASA Astrophysics Data System (ADS)

Krieg, Todd D.; Salinas, Felipe S.; Narayana, Shalini; Fox, Peter T.; Mogul, David J.

2015-08-01

Objective. Transcranial magnetic stimulation (TMS) represents a powerful technique to noninvasively modulate cortical neurophysiology in the brain. However, the relationship between the magnetic fields created by TMS coils and neuronal activation in the cortex is still not well-understood, making predictable cortical activation by TMS difficult to achieve. Our goal in this study was to investigate the relationship between induced electric fields and cortical activation measured by blood flow response. Particularly, we sought to discover the E-field characteristics that lead to cortical activation. Approach. Subject-specific finite element models (FEMs) of the head and brain were constructed for each of six subjects using magnetic resonance image scans. Positron emission tomography (PET) measured each subject’s cortical response to image-guided robotically-positioned TMS to the primary motor cortex. FEM models that employed the given coil position, orientation, and stimulus intensity in experimental applications of TMS were used to calculate the electric field (E-field) vectors within a region of interest for each subject. TMS-induced E-fields were analyzed to better understand what vector components led to regional cerebral blood flow (CBF) responses recorded by PET. Main results. This study found that decomposing the E-field into orthogonal vector components based on the cortical surface geometry (and hence, cortical neuron directions) led to significant differences between the regions of cortex that were active and nonactive. Specifically, active regions had significantly higher E-field components in the normal inward direction (i.e., parallel to pyramidal neurons in the dendrite-to-axon orientation) and in the tangential direction (i.e., parallel to interneurons) at high gradient. In contrast, nonactive regions had higher E-field vectors in the outward normal direction suggesting inhibitory responses. Significance. These results provide critical new understanding of the factors by which TMS induces cortical activation necessary for predictive and repeatable use of this noninvasive stimulation modality.

Use of the Temperament and Character Inventory to Predict Response to Repetitive Transcranial Magnetic Stimulation for Major Depression

PubMed Central

Siddiqi, Shan H.; Chockalingam, Ravikumar; Cloninger, C. Robert; Lenze, Eric J.; Cristancho, Pilar

2016-01-01

Objective . The goal of this study was to investigate the utility of the Temperament and Character Inventory (TCI) in predicting antidepressant response to repetitive transcranial magnetic stimulation (rTMS). Background Although rTMS of the dorsolateral prefrontal cortex (DLPFC) is an established antidepressant treatment, little is known about predictors of response. The TCI measures multiple personality dimensions (harm avoidance, novelty seeking, reward dependence, persistence, self-directedness, self-transcendence, and cooperativeness), some of which have predicted response to pharmacotherapy and cognitive-behavioral therapy. A previous study suggested a possible association between self-directedness and response to rTMS in melancholic depression, although this was limited by the fact that melancholic depression is associated with a limited range of TCI profiles. Methods . Nineteen patients with a major depressive episode completed the TCI prior to a clinical course of rTMS over the DLPFC. Treatment response was defined as ≥50% decrease in scores on the Hamilton Rating Scale for Depression (HAM-D). Baseline scores on each TCI dimension were compared between responders and non-responders via analysis of variance. Pearson correlations were also calculated for temperament/character scores in comparison with percentage improvement in HAM-D scores. Results Eleven of the 19 patients responded to rTMS. T-scores for persistence were significantly higher in responders than in non-responders (P=0.022). Linear regression revealed a correlation between persistence scores and percentage improvement in HAM-D scores. Conclusions Higher persistence scores predicted antidepressant response to rTMS. This may be explained by rTMS-induced enhancement of cortical excitability, which has been found to be decreased in patients with high persistence. Personality assessment that includes measurement of TCI persistence may be a useful component of precision medicine initiatives in rTMS for depression. PMID:27123799

A double-blind, randomized trial of deep repetitive transcranial magnetic stimulation (rTMS) for autism spectrum disorder.

PubMed

Enticott, Peter G; Fitzgibbon, Bernadette M; Kennedy, Hayley A; Arnold, Sara L; Elliot, David; Peachey, Amy; Zangen, Abraham; Fitzgerald, Paul B

2014-01-01

Biomedical treatment options for autism spectrum disorder (ASD) are extremely limited. Repetitive transcranial magnetic stimulation (rTMS) is a safe and efficacious technique when targeting specific areas of cortical dysfunction in major depressive disorder, and a similar approach could yield therapeutic benefits in ASD, if applied to relevant cortical regions. The aim of this study was to examine whether deep rTMS to bilateral dorsomedial prefrontal cortex improves social relating in ASD. 28 adults diagnosed with either autistic disorder (high-functioning) or Asperger's disorder completed a prospective, double-blind, randomized, placebo-controlled design with 2 weeks of daily weekday treatment. This involved deep rTMS to bilateral dorsomedial prefrontal cortex (5 Hz, 10-s train duration, 20-s inter-train interval) for 15 min (1500 pulses per session) using a HAUT-Coil. The sham rTMS coil was encased in the same helmet of the active deep rTMS coil, but no effective field was delivered into the brain. Assessments were conducted before, after, and one month following treatment. Participants in the active condition showed a near significant reduction in self-reported social relating symptoms from pre-treatment to one month follow-up, and a significant reduction in social relating symptoms (relative to sham participants) for both post-treatment assessments. Those in the active condition also showed a reduction in self-oriented anxiety during difficult and emotional social situations from pre-treatment to one month follow-up. There were no changes for those in the sham condition. Deep rTMS to bilateral dorsomedial prefrontal cortex yielded a reduction in social relating impairment and socially-related anxiety. Further research in this area should employ extended rTMS protocols that approximate those used in depression in an attempt to replicate and amplify the clinical response. Copyright © 2014 Elsevier Inc. All rights reserved.

Assessing and inducing neuroplasticity with transcranial magnetic stimulation and robotics for motor function.

PubMed

O'Malley, Marcia K; Ro, Tony; Levin, Harvey S

2006-12-01

To describe 2 new ways of assessing and inducing neuroplasticity in the human brain--transcranial magnetic stimulation (TMS) and robotics--and to investigate and promote the recovery of motor function after brain damage. We identified recent articles and books directly bearing on TMS and robotics. Articles using these tools for purposes other than rehabilitation were excluded. From these studies, we emphasize the methodologic and technical details of these tools as applicable for assessing and inducing plasticity. Because both tools have only recently been used for rehabilitation, the majority of the articles selected for this review have been published only within the last 10 years. We used the PubMed and Compendex databases to find relevant peer-reviewed studies for this review. The studies were required to be relevant to rehabilitation and to use TMS or robotics methodologies. Guidelines were applied via independent extraction by multiple observers. Despite the limited amount of research using these procedures for assessing and inducing neuroplasticity, there is growing evidence that both TMS and robotics can be very effective, inexpensive, and convenient ways for assessing and inducing rehabilitation. Although TMS has primarily been used as an assessment tool for motor function, an increasing number of studies are using TMS as a tool to directly induce plasticity and improve motor function. Similarly, robotic devices have been used for rehabilitation because of their suitability for delivery of highly repeatable training. New directions in robotics-assisted rehabilitation are taking advantage of novel measurements that can be acquired via the devices, enabling unique methods of assessment of motor recovery. As refinements in technology and advances in our knowledge continue, TMS and robotics should play an increasing role in assessing and promoting the recovery of function. Ongoing and future studies combining TMS and robotics within the same populations may prove fruitful for a more detailed and comprehensive assessment of the central and peripheral changes in the nervous system during precisely induced recovery.

Development and characterization of a multilayer matrix textile sensor for interface pressure measurements

NASA Astrophysics Data System (ADS)

Baldoli, Ilaria; Maselli, Martina; Cecchi, Francesca; Laschi, Cecilia

2017-10-01

Matrix textile sensors hold great potential for measuring pressure distribution in applications of modern daily lives, mainly regarding the biomedical field, but also robotics, automotive systems, and wearable and consumer electronics. However, an experimental analysis of their metrological properties is lacking in the literature, thus compromising their widespread acceptance. In the present work, we report the characterization of an 8 × 8 textile sensor assembled by sandwiching a piezoresistive fabric sheet between two outer fabric layers embedding conductive rows and columns. The location of the applied pressure can be identified by detecting the position where the change of resistances occurs between the external conductive paths. The sensor structure, its electrical circuit and characteristics are described in detail, after studying both the integration levels of the hierarchical structure and the composition of the piezoresistive fabric sheet. The pressure measurement range and the calibration curve were studied by tuning circuital parameters. Repeatability, time drift, temperature dependence, signal-to-noise ratio and dynamic response were analyzed. Novel tests were employed to consider the sensor sensitivity to stretch, shear force and surface curvature. A special analysis was taken over hysteresis and dynamic accuracy, focusing on a possible compensating solution. Results indicated that the system provides overall good quality performances with the main drawback of a limited dynamic accuracy, typical of piezoresistive sensing elements. Nevertheless, the use of textiles allows the realization of lightweight, wearable, washable, thin and stretchable sensors. In addition fabric sensors are robust, cheap, easy-to-use and employable to cover large area three dimensional surfaces. The wide characterization reported here could provide precious insights and guidelines to help researchers and users in taking advantages from all of these benefits, supporting them in choosing the best sensor design and application.

Monitoring Antarctic ice sheet surface melting with TIMESAT algorithm

NASA Astrophysics Data System (ADS)

Ye, Y.; Cheng, X.; Li, X.; Liang, L.

2011-12-01

Antarctic ice sheet contributes significantly to the global heat budget by controlling the exchange of heat, moisture, and momentum at the surface-atmosphere interface, which directly influence the global atmospheric circulation and climate change. Ice sheet melting will cause snow humidity increase, which will accelerate the disintegration and movement of ice sheet. As a result, detecting Antarctic ice sheet melting is essential for global climate change research. In the past decades, various methods have been proposed for extracting snowmelt information from multi-channel satellite passive microwave data. Some methods are based on brightness temperature values or a composite index of them, and others are based on edge detection. TIMESAT (Time-series of Satellite sensor data) is an algorithm for extracting seasonality information from time-series of satellite sensor data. With TIMESAT long-time series brightness temperature (SSM/I 19H) is simulated by Double Logistic function. Snow is classified to wet and dry snow with generalized Gaussian model. The results were compared with those from a wavelet algorithm. On this basis, Antarctic automatic weather station data were used for ground verification. It shows that this algorithm is effective in ice sheet melting detection. The spatial distribution of melting areas(Fig.1) shows that, the majority of melting areas are located on the edge of Antarctic ice shelf region. It is affected by land cover type, surface elevation and geographic location (latitude). In addition, the Antarctic ice sheet melting varies with seasons. It is particularly acute in summer, peaking at December and January, staying low in March. In summary, from 1988 to 2008, Ross Ice Shelf and Ronnie Ice Shelf have the greatest interannual variability in amount of melting, which largely determines the overall interannual variability in Antarctica. Other regions, especially Larsen Ice Shelf and Wilkins Ice Shelf, which is in the Antarctic Peninsula region, have relative stable and consistent melt occurrence from year to year.

Rewriting Ice Sheet "Glacier-ology"

NASA Astrophysics Data System (ADS)

Bindschadler, R.

2006-12-01

The revolution in glaciology driven by the suite of increasingly sophisticated satellite instruments has been no more extreme than in the area of ice dynamics. Years ago, glaciologists were (probably unwittingly) selective in what properties of mountain glaciers were also applied to ice sheets. This reinforced the view that they responded slowly to their environment. Notions of rapid response driven by the ideas of John Mercer, Bill Budd and Terry Hughes were politely rejected by the centrists of mainstream glaciological thought. How the tables have turned--and by the ice sheets themselves, captured in the act of rapidly changing by modern remote sensors! The saw-toothed record of sea-level change over past glacial-interglacial cycles required the existence of rapid ice loss processes. Satellite based observations, supported by hard-earned field observations have extended the time scale over which ice sheets can suddenly change to ever shorter intervals: from centuries, to decades, to years to even minutes. As changes continue to be observed, the scientific community is forced to consider new or previously ignored processes to explain these observations. The penultimate goal of ice-sheet dynamics is to credibly predict the future of both the Greenland and Antarctic ice sheets. In this important endeavor, there is no substitute for our ability to observe. Without the extensive data sets provided by remote sensing, numerical models can be neither tested nor improved. The impact of remote sensing on our existing ability to predict the future must be compared to our probable state of knowledge and ability were these data never collected. Among many satellite observed phenomena we would be largely or wholly ignorant of are the recent acceleration of ice throughout much of coastal Greenland; the sudden disintegration of multiple ice shelves along the Antarctic Peninsula; and the dramatic thinning and acceleration of the Amundsen Sea sector of West Antarctica. These observations are driving increased concern about rapidly increasing sea level, a process dominated by ice-sheet dynamics and largely identified, quantified, studied and monitored by satellite sensors.

Multilayer ZnO/Pd/ZnO Structure as Sensing Membrane for Extended-Gate Field-Effect Transistor (EGFET) with High pH Sensitivity

NASA Astrophysics Data System (ADS)

Rasheed, Hiba S.; Ahmed, Naser M.; Matjafri, M. Z.; Al-Hardan, Naif H.; Almessiere, Munirah Abdullah; Sabah, Fayroz A.; Al-Hazeem, Nabeel Z.

2017-10-01

Metal oxide nanostructures have attracted considerable attention as pH-sensitive membranes because of their unique advantages. Specifically, the special properties of ZnO thin film, including high surface-to-volume ratio, nontoxicity, thermal stability, chemical stability, electrochemical activity, and high mechanical strength, have attracted massive interest. ZnO exhibits wide bandgap of 3.37 eV, good biocompatibility, high reactivity, robustness, and environmental stability. These unique properties explain why ZnO has the most applications among all nanostructured metal oxides based on its structure and properties. Moreover, ZnO has excellent electrical characteristics, enabling its use in accurate sensors with rapid response. ZnO nanostructures can be used in novel pH and biomedical sensing applications. However, ZnO thin film exhibits large sheet resistance and low conductivity. Increasing the conductivity or reducing the resistivity of ZnO sensing membranes is important to achieve low impedance. We propose herein a new design using a multilayer ZnO/Pd/ZnO structure as a pH-sensing membrane. Multiple layers were deposited by radio frequency (RF) sputtering for ZnO and direct current (DC) sputtering for Pd to achieve low sheet resistance. These multilayers with low sheet resistance of 15.8 Ω/sq were then successfully used to control the conductivity in extended-gate field-effect transistors (EGFETs). The resulting multilayered EGFET pH-sensor demonstrated improved sensing performance. The measured sensitivity of the pH sensor was 40 μA/pH and 52 mV/pH within the pH range from 2 to 12, rendering this structure suitable for use in various applications, including pH sensors and biosensors.

Surface-Plasmon-Mediated Gradient Force Enhancement and Mechanical State Transitions of Graphene Sheets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Peng; Shen, Nian-Hai; Koschny, Thomas

Graphene, a two-dimensional material possessing extraordinary properties in electronics as well as mechanics, provides a great platform for various optoelectronic and opto-mechanical devices. Here in this article, we theoretically study the optical gradient force arising from the coupling of surface plasmon modes on parallel graphene sheets, which can be several orders stronger than that between regular dielectric waveguides. Furthermore, with an energy functional optimization model, possible force-induced deformation of graphene sheets is calculated. We show that the significantly enhanced optical gradient force may lead to mechanical state transitions of graphene sheets, which are accompanied by abrupt changes in reflection andmore » transmission spectra of the system. Our demonstrations illustrate the potential for a broader graphene-related applications such as force sensors and actuators.« less

Surface-Plasmon-Mediated Gradient Force Enhancement and Mechanical State Transitions of Graphene Sheets

DOE PAGES

Zhang, Peng; Shen, Nian-Hai; Koschny, Thomas; ...

2016-12-16

Graphene, a two-dimensional material possessing extraordinary properties in electronics as well as mechanics, provides a great platform for various optoelectronic and opto-mechanical devices. Here in this article, we theoretically study the optical gradient force arising from the coupling of surface plasmon modes on parallel graphene sheets, which can be several orders stronger than that between regular dielectric waveguides. Furthermore, with an energy functional optimization model, possible force-induced deformation of graphene sheets is calculated. We show that the significantly enhanced optical gradient force may lead to mechanical state transitions of graphene sheets, which are accompanied by abrupt changes in reflection andmore » transmission spectra of the system. Our demonstrations illustrate the potential for a broader graphene-related applications such as force sensors and actuators.« less

Nitrotyrosine adsorption on defective graphene: A density functional theory study

NASA Astrophysics Data System (ADS)

Majidi, R.; Karami, A. R.

2015-06-01

We have applied density functional theory to study adsorption of nitrotyrosine on perfect and defective graphene sheets. The graphene sheets with Stone-Wales (SW) defect, pentagon-nonagon (5-9) single vacancy, and pentagon-octagon-pentagon (5-8-5) double vacancy were considered. The calculations of adsorption energy showed that nitrotyrosine presents a more strong interaction with defective graphene rather than with perfect graphene sheet. The order of interaction strength is: SW>5-9>5-8-5>perfect graphene. It is found that the electronic properties of perfect and defective graphene are sensitive to the presence of nitrotyrosine. Hence, graphene sheets can be considered as a good sensor for detection of nitrotyrosine molecule which is observed in connection with several human disorders, such as Parkinson's and Alzheimer's disease.

Initial rigid response and softening transition of highly stretchable kirigami sheet materials.

PubMed

Isobe, Midori; Okumura, Ko

2016-04-27

We study, experimentally and theoretically, the mechanical response of sheet materials on which line cracks or cuts are arranged in a simple pattern. Such sheet materials, often called kirigami (the Japanese words, kiri and gami, stand for cut and paper, respectively), demonstrate a unique mechanical response promising for various engineering applications such as stretchable batteries: kirigami sheets possess a mechanical regime in which sheets are highly stretchable and very soft compared with the original sheets without line cracks, by virtue of out-of-plane deformation. However, this regime starts after a transition from an initial stiff regime governed by in-plane deformation. In other words, the softness of the kirigami structure emerges as a result of a transition from the two-dimensional to three-dimensional deformation, i.e., from stretching to bending. We clarify the physical origins of the transition and mechanical regimes, which are revealed to be governed by simple scaling laws. The results could be useful for controlling and designing the mechanical response of sheet materials including cell sheets for medical regeneration and relevant to the development of materials with tunable stiffness and mechanical force sensors.

The Rapid Ice Sheet Change Observatory (RISCO)

NASA Astrophysics Data System (ADS)

Morin, P.; Howat, I. M.; Ahn, Y.; Porter, C.; McFadden, E. M.

2010-12-01

The recent expansion of observational capacity from space has revealed dramatic, rapid changes in the Earth’s ice cover. These discoveries have fundamentally altered how scientists view ice-sheet change. Instead of just slow changes in snow accumulation and melting over centuries or millennia, important changes can occur in sudden events lasting only months, weeks, or even a single day. Our understanding of these short time- and space-scale processes, which hold important implications for future global sea level rise, has been impeded by the low temporal and spatial resolution, delayed sensor tasking, incomplete coverage, inaccessibility and/or high cost of data available to investigators. New cross-agency partnerships and data access policies provide the opportunity to dramatically improve the resolution of ice sheet observations by an order of magnitude, from timescales of months and distances of 10’s of meters, to days and meters or less. Advances in image processing technology also enable application of currently under-utilized datasets. The infrastructure for systematically gathering, processing, analyzing and distributing these data does not currently exist. Here we present the development of a multi-institutional, multi-platform observatory for rapid ice change with the ultimate objective of helping to elucidate the relevant timescales and processes of ice sheet dynamics and response to climate change. The Rapid Ice Sheet Observatory (RISCO) gathers observations of short time- and space-scale Cryosphere events and makes them easily accessible to investigators, media and general public. As opposed to existing data centers, which are structured to archive and distribute diverse types of raw data to end users with the specialized software and skills to analyze them, RISCO focuses on three types of geo-referenced raster (image) data products in a format immediately viewable with commonly available software. These three products are (1) sequences of images and image animations from the ice sheet scale down to scales of meters, (2) maps of ice flow velocity and acceleration and (3) digital elevation models and elevation change maps. These products are created both from user-tasked data acquisitions and from a decade of archived data. An online user interface will allow browsing of the data catalog, product ordering and requests for sensor tasking. Over the next few years, RISCO will develop into a long-term observational system, with an adaptable infrastructure to accommodate new sensors and currently unforeseeable demands. RISCO has the potential to greatly enhance observation of ice sheets, moving from ad hoc studies of past changes using whatever data happens to be available, to scalable, targeted, near-real time monitoring of events as they occur.

Preliminary Evidence of the Effects of High-frequency Repetitive Transcranial Magnetic Stimulation (rTMS) on Swallowing Functions in Post-Stroke Individuals with Chronic Dysphagia

ERIC Educational Resources Information Center

Cheng, Ivy K. Y.; Chan, Karen M. K.; Wong, C. S.; Cheung, Raymond T. F.

2015-01-01

Background: There is growing evidence of potential benefits of repetitive transcranial magnetic stimulation (rTMS) in the rehabilitation of dysphagia. However, the site and frequency of stimulation for optimal effects are not clear. Aims: The aim of this pilot study is to investigate the short-term effects of high-frequency 5 Hz rTMS applied to…

41 CFR 301-50.5 - What is my liability if I do not use my agency's TMS or the E-Gov Travel Service, and an...

Code of Federal Regulations, 2011 CFR

2011-07-01

... I do not use my agency's TMS or the E-Gov Travel Service, and an exception has not been approved... or the E-Gov Travel Service, and an exception has not been approved? If you do not have an approved... resulting from the failure to use the TMS or E-Gov Travel Service, including service fees, cancellation...

41 CFR 301-50.5 - What is my liability if I do not use my agency's TMS or the E-Gov Travel Service, and an...

Code of Federal Regulations, 2014 CFR

2014-07-01

... I do not use my agency's TMS or the E-Gov Travel Service, and an exception has not been approved... or the E-Gov Travel Service, and an exception has not been approved? If you do not have an approved... resulting from the failure to use the TMS or E-Gov Travel Service, including service fees, cancellation...

41 CFR 301-50.5 - What is my liability if I do not use my agency's TMS or the E-Gov Travel Service, and an...

Code of Federal Regulations, 2012 CFR

2012-07-01

... I do not use my agency's TMS or the E-Gov Travel Service, and an exception has not been approved... or the E-Gov Travel Service, and an exception has not been approved? If you do not have an approved... resulting from the failure to use the TMS or E-Gov Travel Service, including service fees, cancellation...

41 CFR 301-73.105 - What are the consequences of an employee not using the E-Gov Travel Service or the TMS?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 41 Public Contracts and Property Management 4 2014-07-01 2014-07-01 false What are the consequences of an employee not using the E-Gov Travel Service or the TMS? 301-73.105 Section 301-73.105 Public... What are the consequences of an employee not using the E-Gov Travel Service or the TMS? If an employee...

41 CFR 301-73.105 - What are the consequences of an employee not using the E-Gov Travel Service or the TMS?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 41 Public Contracts and Property Management 4 2013-07-01 2012-07-01 true What are the consequences of an employee not using the E-Gov Travel Service or the TMS? 301-73.105 Section 301-73.105 Public... What are the consequences of an employee not using the E-Gov Travel Service or the TMS? If an employee...

41 CFR 301-50.5 - What is my liability if I do not use my agency's TMS or the E-Gov Travel Service, and an...

Code of Federal Regulations, 2010 CFR

2010-07-01

... I do not use my agency's TMS or the E-Gov Travel Service, and an exception has not been approved... or the E-Gov Travel Service, and an exception has not been approved? If you do not have an approved... resulting from the failure to use the TMS or E-Gov Travel Service, including service fees, cancellation...

41 CFR 301-73.105 - What are the consequences of an employee not using the E-Gov Travel Service or the TMS?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false What are the consequences of an employee not using the E-Gov Travel Service or the TMS? 301-73.105 Section 301-73.105 Public... What are the consequences of an employee not using the E-Gov Travel Service or the TMS? If an employee...

41 CFR 301-73.105 - What are the consequences of an employee not using the E-Gov Travel Service or the TMS?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false What are the consequences of an employee not using the E-Gov Travel Service or the TMS? 301-73.105 Section 301-73.105 Public... What are the consequences of an employee not using the E-Gov Travel Service or the TMS? If an employee...

41 CFR 301-73.105 - What are the consequences of an employee not using the E-Gov Travel Service or the TMS?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false What are the consequences of an employee not using the E-Gov Travel Service or the TMS? 301-73.105 Section 301-73.105 Public... What are the consequences of an employee not using the E-Gov Travel Service or the TMS? If an employee...

41 CFR 301-50.5 - What is my liability if I do not use my agency's TMS or the E-Gov Travel Service, and an...

Code of Federal Regulations, 2013 CFR

2013-07-01

... do not use my agency's TMS or the E-Gov Travel Service, and an exception has not been approved? 301... or the E-Gov Travel Service, and an exception has not been approved? If you do not have an approved... resulting from the failure to use the TMS or E-Gov Travel Service, including service fees, cancellation...

rTMS for PTSD: induced merciful oblivion or elimination of abnormal hypermnesia?

PubMed

Rossi, Simone; Cappa, Stefano F; Ulivelli, Monica; De Capua, Alberto; Bartalini, Sabina; Rossini, Paolo M

2006-01-01

Neuroimaging studies and experimental data suggest that symptoms of posttraumatic stress disorder (PTSD) are associated with dysfunctions of neural circuits linking prefrontal cortex and the limbic system that have a role in autobiographic episodic memory. High-frequency repetitive transcranial magnetic stimulation (rTMS) of the right dorsolateral prefrontal cortex (DLPFC) has been suggested to be beneficial to patients with PTSD, transiently alleviating re-experiencing as well as avoidance reactions and associated anxiety symptoms. In healthy humans, converging evidence suggests that rTMS of the right DLPFC interferes with episodic memory retrieval. Hence, we hypothesize that daily applications of rTMS in PTSD patients may reduce access to the set of autobiographical stored events, that, if re-experienced, may cause the overt PTSD symptoms.

[The application of high-frequency and iTBS transcranial magnetic stimulation for the treatment of spasticity in the patients presenting with secondary progressive multiple sclerosis].

PubMed

Korzhova, J E; Chervyakov, A V; Poydasheva, A G; Kochergin, I A; Peresedova, A V; Zakharova, M N; Suponeva, N A; Chernikova, L A; Piradov, M A

Spasticity is considered to be a common manifestation of multiple sclerosis. Muscle relaxants are not sufficiently effective; more than that, some of them often cause a variety of adverse reactions. Transcranial magnetic stimulation (TMS) can be a promising new tool for the treatment of spasticity. The objective of the present study was to compare the effectiveness of the two TMS protocols: rhythmic (high-frequency) TMS (rTMS) and stimulation with the theta bursts (iTBS) in terms of their ability to reduce spasticity in the patients presenting with multiple sclerosis. Twenty two patients with secondary-progressive multiple sclerosis were pseudo-randomized into two groups: those in the first (high-frequency) group received the treatment with the use of rTMS therapy at a frequency of 10 Hz; the patients of the second group, underwent stimulation with the theta bursts (iTBS). All the patients received 10 sessions of either stimulation applied to the primary motor area (M1) of both legs. The effectiveness of TMS protocols was evaluated before therapy and after 10 sessions of stimulation based on the Modified Ashworth scale (MAS), the expanded disability status scale (EDSS), and the Kurtzke functional scale (Kfs). In addition, the patients were interviewed before treatment, after 10 rTMS sessions, immediately after and within 2 and 12 weeks after the completion of the treatment using questionnaires for the evaluation of spasticity (SESS) , fatigue, and dysfunction of the pelvic organs (severity of defecation and urination disorders), fatigue. The study has demonstrated a significant reduction in spasticity in the patients of both groups at the end of the TMS protocol based on the MAS scale. There was no significant difference between the outcomes of the two protocols. Both had positive effect on the concomitant «non-motor» symptoms (fatigue, dysfunction of the pelvic organs). High-frequency transcranial magnetic stimulation (10 sessions of rTMS therapy at a frequency of 10 Hz) and stimulation with the theta-bursts applied to the M1 area in both legs can be an effective alternative treatment of spasticity in the patients with secondary-progressive multiple sclerosis. Further research is needed to detect more accurately the differences between the outcomes of the two stimulation protocols and the development of indications for their application on an individual basis.

Repetitive Transcranial Magnetic Stimulation (rTMS) Therapy in Parkinson Disease: A Meta-Analysis.

PubMed

Wagle Shukla, Aparna; Shuster, Jonathan J; Chung, Jae Woo; Vaillancourt, David E; Patten, Carolynn; Ostrem, Jill; Okun, Michael S

2016-04-01

Several studies have reported repetitive transcranial magnetic stimulation (rTMS) therapy as an effective treatment for the control of motor symptoms in Parkinson disease. The objective of the study is to quantify the overall efficacy of this treatment. Systematic review and meta-analysis. We reviewed the literature on clinical rTMS trials in Parkinson disease since the technique was introduced in 1980. We used the following databases: MEDLINE, Web of Science, Cochrane, and CINAHL. Patients with Parkinson disease who were participating in prospective clinical trials that included an active arm and a control arm and change in motor scores on Unified Parkinson's Disease Rating Scale as the primary outcome. We pooled data from 21 studies that met these criteria. We then analyzed separately the effects of low- and high-frequency rTMS on clinical motor improvements. The overall pooled mean difference between treatment and control groups in the Unified Parkinson's Disease Rating Scale motor score was significant (4.0 points, 95% confidence interval, 1.5, 6.7; P = .005). rTMS therapy was effective when low-frequency stimulation (≤ 1 Hz) was used with a pooled mean difference of 3.3 points (95% confidence interval 1.6, 5.0; P = .005). There was a trend for significance when high-frequency stimulation (≥ 5 Hz) studies were evaluated with a pooled mean difference of 3.9 points (95% confidence interval, -0.7, 8.5; P = .08). rTMS therapy demonstrated benefits at short-term follow-up (immediately after a treatment protocol) with a pooled mean difference of 3.4 points (95% confidence interval, 0.3, 6.6; P = .03) as well as at long-term follow-up (average follow-up 6 weeks) with mean difference of 4.1 points (95% confidence interval, -0.15, 8.4; P = .05). There were insufficient data to statistically analyze the effects of rTMS when we specifically examined bradykinesia, gait, and levodopa-induced dyskinesia using quantitative methods. rTMS therapy in patients with Parkinson disease results in mild-to-moderate motor improvements and has the potential to be used as an adjunct therapy for the treatment of Parkinson disease. Future large, sample studies should be designed to isolate the specific clinical features of Parkinson disease that respond well to rTMS therapy. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Repetitive transcranial magnetic stimulation versus electroconvulsive therapy for major depression: a systematic review and meta-analysis.

PubMed

Ren, Juanjuan; Li, Hui; Palaniyappan, Lena; Liu, Hongmei; Wang, Jijun; Li, Chunbo; Rossini, Paolo Maria

2014-06-03

Electroconvulsive therapy (ECT) is the most effective treatment of depression. During the last decades repetitive transcranial magnetic stimulation (rTMS), an alternative method using electric stimulation of the brain, has revealed possible alternative to ECT in the treatment of depression. There are some clinical trials comparing their efficacies and safeties but without clear conclusions, mainly due to their small sample sizes. In the present study, a meta-analysis had been carried out to gain statistical power. Outcomes were response, remission, acceptability and cognitive effects in depression. Following a comprehensive literature search that included both English and Chinese language databases, we identified all randomized controlled trials that directly compared rTMS and ECT for major depression. 10 articles (9 trials) with a total of 425 patients were identified. Methodological quality, heterogeneity, sensitivity and publication bias were systematically evaluated. ECT was superior to high frequency rTMS in terms of response (64.4% vs. 48.7%, RR = 1.41, p = 0.03), remission (52.9% vs. 33.6%, RR = 1.38, p = 0.006) while discontinuation was not significantly different between the two treatments (8.3% vs. 9.4%, RR = 1.11, p = 0.80). According to the subgroup analysis, the superiority of ECT was more apparent in those with psychotic depression, while high frequency rTMS was as effective as ECT in those with non-psychotic depression. The same results were obtained in the comparison of ECT with low frequency rTMS. ECT had a non-significant advantage over high frequency rTMS on the overall improvement in HAMD scores (p = 0.11). There was insufficient data on medium or long term efficacy. Both rTMS and ECT were well tolerated with only minor side effects reported. Results based on 3 studies suggested that specific cognitive domains such as visual memory and verbal fluency were more impaired in patients receiving ECT. In conclusion, ECT seemed more effective than and at least as acceptable as rTMS in the short term, especially in the presence of psychotic depression. This review identified the lack of good quality trials comparing the long-term outcome and cognitive effects of rTMS and ECT, especially using approaches to optimize stimulus delivery and reduce clinical heterogeneity. Copyright © 2014 Elsevier Inc. All rights reserved.

Efficacy of deep rTMS for neuropathic pain in the lower limb: a randomized, double-blind crossover trial of an H-coil and figure-8 coil.

PubMed

Shimizu, Takeshi; Hosomi, Koichi; Maruo, Tomoyuki; Goto, Yuko; Yokoe, Masaru; Kageyama, Yu; Shimokawa, Toshio; Yoshimine, Toshiki; Saitoh, Youichi

2017-11-01

OBJECTIVE Electrical motor cortex stimulation can relieve neuropathic pain (NP), but its use requires patients to undergo an invasive procedure. Repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex (M1) using a figure-8 coil can relieve NP noninvasively, but its ability to relieve lower limb pain is still limited. Deep rTMS using an H-coil can effectively stimulate deep brain regions and has been widely used for the treatment of various neurological diseases; however, there have been no clinical studies comparing the effectiveness of figure-8 coils and H-coils. This study assessed the clinical effectiveness of 5 once-daily stimulations with H-coils and figure-8 coils in patients with NP. METHODS This randomized, double-blind, 3-way crossover trial examined 18 patients with NP who sequentially received 3 types of stimulations in the M1 for 5 consecutive days; each 5-day stimulation period was followed by a 17-day follow-up period before crossing over to the next type of stimulation. During each rTMS session, patients received a 5-Hz rTMS to the M1 region corresponding to the painful lower limb. The visual analog scale (VAS) and the Japanese version of the short-form McGill Pain Questionnaire 2 (SF-MPQ2-J) were used to measure pain intensity. The primary outcome was VAS score reduction immediately after and 1 hour after intervention. RESULTS Both the VAS and SF-MPQ2-J showed significant pain improvement immediately after deep rTMS with an H-coil as compared with the sham group (p < 0.001 and p = 0.049, respectively). However, neither outcome measure showed significant pain improvement when using a figure-8 coil. The VAS also showed significant pain improvement 1 hour after deep rTMS with an H-coil (p = 0.004) but not 1 hour after rTMS using a figure-8 coil. None of the patients exhibited any serious adverse events. CONCLUSIONS The current findings suggest that the use of deep rTMS with an H-coil in the lower limb region of the M1 in patients with NP was tolerable and could provide significant short-term pain relief. Clinical trial registration no.: UMIN000010536 ( http://www.umin.ac.jp/ctr/ ).

A light sheet confocal microscope for image cytometry with a variable linear slit detector

NASA Astrophysics Data System (ADS)

Hutcheson, Joshua A.; Khan, Foysal Z.; Powless, Amy J.; Benson, Devin; Hunter, Courtney; Fritsch, Ingrid; Muldoon, Timothy J.

2016-03-01

We present a light sheet confocal microscope (LSCM) capable of high-resolution imaging of cell suspensions in a microfluidic environment. In lieu of conventional pressure-driven flow or mechanical translation of the samples, we have employed a novel method of fluid transport, redox-magnetohydrodynamics (redox-MHD). This method achieves fluid motion by inducing a small current into the suspension in the presence of a magnetic field via electrodes patterned onto a silicon chip. This on-chip transportation requires no moving parts, and is coupled to the remainder of the imaging system. The microscopy system comprises a 450 nm diode 20 mW laser coupled to a single mode fiber and a cylindrical lens that converges the light sheet into the back aperture of a 10x, 0.3 NA objective lens in an epi-illumination configuration. The emission pathway contains a 150 mm tube lens that focuses the light onto the linear sensor at the conjugate image plane. The linear sensor (ELiiXA+ 8k/4k) has three lateral binning modes which enables variable detection aperture widths between 5, 10, or 20 μm, which can be used to vary axial resolution. We have demonstrated redox-MHD-enabled light sheet microscopy in suspension of fluorescent polystyrene beads. This approach has potential as a high-throughput image cytometer with myriad cellular diagnostic applications.

Silver Nanowire Embedded Colorless Polyimide Heater for Wearable Chemical Sensors: Improved Reversible Reaction Kinetics of Optically Reduced Graphene Oxide.

PubMed

Choi, Seon-Jin; Kim, Sang-Joon; Jang, Ji-Soo; Lee, Ji-Hyun; Kim, Il-Doo

2016-09-14

Optically reduced graphene oxide (ORGO) sheets are successfully integrated on silver nanowire (Ag NW)-embedded transparent and flexible substrate. As a heating element, Ag NWs are embedded in a colorless polyimide (CPI) film by covering Ag NW networks using polyamic acid and subsequent imidization. Graphene oxide dispersed aqueous solution is drop-coated on the Ag NW-embedded CPI (Ag NW-CPI) film and directly irradiated by intense pulsed light to obtain ORGO sheets. The heat generation property of Ag NW-CPI film is investigated by applying DC voltage, which demonstrates unprecedentedly reliable and stable characteristics even in dynamic bending condition. To demonstrate the potential application in wearable chemical sensors, NO 2 sensing characteristic of ORGO is investigated with respect to the different heating temperature (22.7-71.7 °C) of Ag NW-CPI film. The result reveals that the ORGO sheets exhibit high sensitivity of 2.69% with reversible response/recovery sensing properties and minimal deviation of baseline resistance of around 1% toward NO 2 molecules when the temperature of Ag NW-CPI film is 71.7 °C. This work first demonstrates the improved reversible NO 2 sensing properties of ORGO sheets on flexible and transparent Ag NW-CPI film assisted by Ag NW heating networks. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effectiveness of 1 Hz rTMS Over the Primary Motor Area of the Unaffected Hemisphere to Improve Hand Function After Stroke Depends on Hemispheric Dominance.

PubMed

Lüdemann-Podubecká, Jitka; Bösl, Kathrin; Theilig, Steven; Wiederer, Ralf; Nowak, Dennis Alexander

2015-01-01

Inhibition of motor cortex excitability of the contralesional hemisphere may improve dexterity of the affected hand after stroke. 40 patients (17 dominant hemispheric stroke, 23 non-dominant hemispheric stroke) with a mild to moderate upper limb motor impairment were enrolled in a double-blind, randomized, placebo-controlled trial with two parallel-groups. Both groups received 15 daily sessions of motor training preceded by either 1 Hz rTMS or sham rTMS. Behavioral and neurophysiological evaluations were performed at baseline, after the first week and after the third week of treatment, and after a 6 months follow-up. In both groups motor function of the affected hand improved significantly. Patients with stroke of the non-dominant hemisphere made a similar improvement, regardless of whether the motor training was preceded by sham or 1 Hz rTMS. Patients with stroke of the dominant hemisphere had a less favorable improvement than those with stroke of the non-dominant hemisphere after motor training preceded by sham rTMS. However, when 1 Hz rTMS preceded the motor training, patients with stroke of the dominant hemisphere made a similar improvement as those with stroke of the non-dominant hemisphere. Motor recovery of the affected upper limb after stroke is determined by dominance of the affected hemisphere. Stroke of the dominant hemisphere is associated with per se poorer improvement of the affected hand. 1 Hz rTMS over the contralesional M1 significantly improves dexterity of the affected hand in patients with stroke of the dominant hemisphere, but not in those with stroke of the non-dominant hemisphere. Copyright © 2015 Elsevier Inc. All rights reserved.

A proof-of-concept study on the combination of repetitive transcranial magnetic stimulation and relaxation techniques in chronic tinnitus.

PubMed

Kreuzer, Peter M; Poeppl, Timm B; Bulla, Jan; Schlee, Winfried; Lehner, Astrid; Langguth, Berthold; Schecklmann, Martin

2016-10-01

Interference of ongoing neuronal activity and brain stimulation motivated this study to combine repetitive transcranial magnetic stimulation (rTMS) and relaxation techniques in tinnitus patients. Forty-two patients were enrolled in this one-arm proof-of-concept study to receive ten sessions of rTMS applied to the left dorsolateral prefrontal cortex and temporo-parietal cortex. During stimulation, patients listened to five different kinds of relaxation audios. Variables of interest were tinnitus questionnaires, tinnitus numeric rating scales, depressivity, and quality of life. Results were compared to results of historical control groups having received the same rTMS protocol (active control) and sham treatment (placebo) without relaxation techniques. Thirty-eight patients completed the treatment, drop-out rates and adverse events were low. Responder rates (reduction in tinnitus questionnaire (TQ) score ≥5 points 10 weeks after treatment) were 44.7 % in the study, 27.8 % in the active control group, and 21.7 % in the placebo group, differing between groups on a near significant level. For the tinnitus handicap inventory (THI), the main effect of group was not significant. However, linear mixed model analyses showed that the relaxation/rTMS group differed significantly from the active control group showing steeper negative THI trend for the relaxation/rTMS group indicating better amelioration over the course of the trial. Deepness of relaxation during rTMS and selection of active relaxation vs. passive listening to music predicted larger TQ. All remaining secondary outcomes turned out non-significant. This combined treatment proved to be a safe, feasible and promising approach to enhance rTMS treatment effects in chronic tinnitus.

The Effectiveness of Transcranial Brain Stimulation in Improving Clinical Signs of Hyperkinetic Movement Disorders.

PubMed

Obeso, Ignacio; Cerasa, Antonio; Quattrone, Aldo

2015-01-01

Repetitive transcranial magnetic stimulation (rTMS) is a safe and painless method for stimulating cortical neurons. In neurological realm, rTMS has prevalently been applied to understand pathophysiological mechanisms underlying movement disorders. However, this tool has also the potential to be translated into a clinically applicable therapeutic use. Several available studies supported this hypothesis, but differences in protocols, clinical enrollment, and variability of rTMS effects across individuals complicate better understanding of efficient clinical protocols. The aim of this present review is to discuss to what extent the evidence provided by the therapeutic use of rTMS may be generalized. In particular, we attempted to define optimal cortical regions and stimulation protocols that have been demonstrated to maximize the effectiveness seen in the actual literature for the three most prevalent hyperkinetic movement disorders: Parkinson's disease (PD) with levodopa-induced dyskinesias (LIDs), essential tremor (ET) and dystonia. A total of 28 rTMS studies met our search criteria. Despite clinical and methodological differences, overall these studies demonstrated that therapeutic applications of rTMS to "normalize" pathologically decreased or increased levels of cortical activity have given moderate progress in patient's quality of life. Moreover, the present literature suggests that altered pathophysiology in hyperkinetic movement disorders establishes motor, premotor or cerebellar structures as candidate regions to reset cortico-subcortical pathways back to normal. Although rTMS has the potential to become a powerful tool for ameliorating the clinical outcome of hyperkinetic neurological patients, until now there is not a clear consensus on optimal protocols for these motor disorders. Well-controlled multicenter randomized clinical trials with high numbers of patients are urgently required.

Effect of Bilateral Prefrontal rTMS on Left Prefrontal NAA and Glx Levels in Schizophrenia Patients with Predominant Negative Symptoms: An Exploratory Study.

PubMed

Dlabac-de Lange, Jozarni J; Liemburg, Edith J; Bais, Leonie; van de Poel-Mustafayeva, Aida T; de Lange-de Klerk, Elly S M; Knegtering, Henderikus; Aleman, André

Prefrontal repetitive Transcranial Magnetic Stimulation (rTMS) may improve negative symptoms in patients with schizophrenia, but few studies have investigated the underlying neural mechanism. This study aims to investigate changes in the levels of glutamate and glutamine (Glx, neurotransmitter and precursor) and N-Acetyl Aspartate (NAA) in the left dorsolateral prefrontal cortex of patients with schizophrenia treated with active bilateral prefrontal rTMS as compared to sham-rTMS, as measured with 1 H-Magnetic Resonance Spectroscopy ( 1 H-MRS). Patients were randomized to a 3-week course of active or sham high-frequency rTMS. Pre-treatment and post-treatment 1 H-MRS data were available for 24 patients with schizophrenia with moderate to severe negative symptoms (Positive and Negative Syndrome Scale (PANSS) negative subscale ≥ 15). Absolute metabolite concentrations were calculated using LCModel with the water peak as reference. To explore the association between treatment condition and changes in concentration of Glx and NAA, we applied a linear regression model. We observed an increase of Glx concentration in the active treatment group and a decrease of Glx concentration in the group receiving sham treatment. The association between changes in Glx concentration and treatment condition was significant. No significant associations between changes in NAA and treatment condition were found. Noninvasive neurostimulation with high-frequency bilateral prefrontal rTMS may influence Glx concentration in the prefrontal cortex of patients with schizophrenia. Larger studies are needed to confirm these findings and further elucidate the underlying neural working mechanism of rTMS. Copyright © 2016 Elsevier Inc. All rights reserved.

Transcranial magnetic stimulation of the left dorsolateral prefrontal cortex decreases cue-induced nicotine craving and EEG delta power.

PubMed

Pripfl, Jürgen; Tomova, Livia; Riecansky, Igor; Lamm, Claus

2014-01-01

TMS has high potential as smoking cessation treatment. However, the neural mechanisms underlying TMS induced reduction of tobacco craving remain unclear. Electroencephalographic (EEG) delta frequency has been associated with the activity of the dopaminergic brain reward system, which is crucial for nicotine induced effects, and decreases after nicotine admission in smokers. The aim of this study was to investigate EEG delta power changes induced by hf rTMS of the left dorsolateral prefrontal cortex (DLPFC) in nicotine deprived smokers and it's relation to cue-induced nicotine craving. Fourteen healthy smokers meeting ICD-10 criteria for tobacco addiction participated in this within-subject sham controlled study. Participants had to abstain from smoking 6 h before the experiment. Effects of high-frequency repetitive TMS (hf rTMS) (10 Hz) for verum (left DLPFC) and sham (vertex) stimulations on cue-induced nicotine craving and resting state EEG delta power were assessed before and three times within 40 min after rTMS. Both craving (P = 0.046) and EEG delta power (P = 0.048) were significantly lower after verum stimulation compared to sham stimulation across the whole post stimulation time period assessed. However, changes of craving ratings and delta power did not correlate. Hf rTMS applied to the left DLPFC reduces nicotine craving in short-term abstinent smokers. Changes in delta activity support the idea that stimulation induced effects are mediated by the dopaminergic brain reward system, which presumably plays a prominent, but probably not exclusive, role in this stimulation induced behavioral modulation, making this method a promising smoking cessation treatment candidate. Copyright © 2014 Elsevier Inc. All rights reserved.

PET-Based Confirmation of Orientation Sensitivity of TMS-Induced Cortical Activation in Humans

PubMed Central

Krieg, Todd D.; Salinas, Felipe S.; Narayana, Shalini; Fox, Peter T.; Mogul, David J.

2017-01-01

Background Currently, it is difficult to predict precise regions of cortical activation in response to transcranial magnetic stimulation (TMS). Most analytical approaches focus on applied magnetic field strength in the target region as the primary factor, placing activation on the gyral crowns. However, imaging studies support M1 targets being typically located in the sulcal banks. Objective/hypothesis To more thoroughly investigate this inconsistency, we sought to determine whether neocortical surface orientation was a critical determinant of regional activation. Methods MR images were used to construct cortical and scalp surfaces for 18 subjects. The angle (θ) between the cortical surface normal and its nearest scalp normal for ~50,000 cortical points per subject was used to quantify cortical location (i.e., gyral vs. sulcal). TMS-induced activations of primary motor cortex (M1) were compared to brain activations recorded during a finger-tapping task using concurrent positron emission tomographic (PET) imaging. Results Brain activations were primarily sulcal for both the TMS and task activations (P < 0.001 for both) compared to the overall cortical surface orientation. Also, the location of maximal blood flow in response to either TMS or finger-tapping correlated well using the cortical surface orientation angle or distance to scalp (P < 0.001 for both) as criteria for comparison between different neocortical activation modalities. Conclusion This study provides further evidence that a major factor in cortical activation using TMS is the orientation of the cortical surface with respect to the induced electric field. The results show that, despite the gyral crown of the cortex being subjected to a larger magnetic field magnitude, the sulcal bank of M1 had larger cerebral blood flow (CBF) responses during TMS. PMID:23827648

Modulation of motor control in saccadic behaviors by TMS over the posterior parietal cortex.

PubMed

Liang, Wei-Kuang; Juan, Chi-Hung

2012-08-01

The right posterior parietal cortex (rPPC) has been found to be critical in shaping visual selection and distractor-induced saccade curvature in the context of predictive as well as nonpredictive visual cues by means of transcranial magnetic stimulation (TMS) interference. However, the dynamic details of how distractor-induced saccade curvatures are affected by rPPC TMS have not yet been investigated. This study aimed to elucidate the key dynamic properties that cause saccades to curve away from distractors with different degrees of curvature in various TMS and target predictability conditions. Stochastic optimal feedback control theory was used to model the dynamics of the TMS saccade data. This allowed estimation of torques, which was used to identify the critical dynamic mechanisms producing saccade curvature. The critical mechanisms of distractor-induced saccade curvatures were found to be the motor commands and torques in the transverse direction. When an unpredictable saccade target occurred with rPPC TMS, there was an initial period of greater distractor-induced torque toward the side opposite the distractor in the transverse direction, immediately followed by a relatively long period of recovery torque that brought the deviated trace back toward the target. The results imply that the mechanisms of distractor-induced saccade curvature may be comprised of two mechanisms: the first causing the initial deviation and the second bringing the deviated trace back toward the target. The pattern of the initial torque in the transverse direction revealed the former mechanism. Conversely, the later mechanism could be well explained as a consequence of the control policy in this model. To summarize, rPPC TMS increased the initial torque away from the distractor as well as the recovery torque toward the target.

Cortico-cortical and motor evoked potentials to single and paired-pulse stimuli: An exploratory transcranial magnetic and intracranial electric brain stimulation study.

PubMed

Boulogne, Sébastien; Andre-Obadia, Nathalie; Kimiskidis, Vasilios K; Ryvlin, Philippe; Rheims, Sylvain

2016-11-01

Paired-pulse (PP) paradigms are commonly employed to assess in vivo cortical excitability using transcranial magnetic stimulation (TMS) to stimulate the primary motor cortex and modulate the induced motor evoked potential (MEP). Single-pulse cortical direct electrical stimulation (DES) during intracerebral EEG monitoring allows the investigation of brain connectivity by eliciting cortico-cortical evoked potentials (CCEPs). However, PP paradigm using intracerebral DES has rarely been reported and has never been previously compared with TMS. The work was intended (i) to verify that the well-established modulations of MEPs following PP TMS remain similar using DES in the motor cortex, and (ii) to evaluate if a similar pattern could be observed in distant cortico-cortical connections through modulations of CCEP. Three patients undergoing intracerebral EEG monitoring with electrodes implanted in the central region were studied. Single-pulse DES (1-3 mA, 1 ms, 0.2 Hz) and PP DES using six interstimulus intervals (5, 15, 30, 50, 100, and 200 ms) in the motor cortex with concomitant recording of CCEPs and MEPs in contralateral muscles were performed. Finally, a navigated PP TMS session targeted the intracranial stimulation site to record TMS-induced MEPs in two patients. MEP modulations elicited by PP intracerebral DES proved similar among the three patients and to those obtained by PP TMS. CCEP modulations elicited by PP intracerebral DES usually showed a pattern comparable to that of MEP, although a different pattern could be observed occasionally. PP intracerebral DES seems to involve excitatory and inhibitory mechanisms similar to PP TMS and allows the recording of intracortical inhibition and facilitation modulation on cortico-cortical connections. Hum Brain Mapp 37:3767-3778, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation

PubMed Central

Sadeh, Boaz; Yovel, Galit

2014-01-01

Transcranial Magnetic Stimulation (TMS) is an effective method for establishing a causal link between a cortical area and cognitive/neurophysiological effects. Specifically, by creating a transient interference with the normal activity of a target region and measuring changes in an electrophysiological signal, we can establish a causal link between the stimulated brain area or network and the electrophysiological signal that we record. If target brain areas are functionally defined with prior fMRI scan, TMS could be used to link the fMRI activations with evoked potentials recorded. However, conducting such experiments presents significant technical challenges given the high amplitude artifacts introduced into the EEG signal by the magnetic pulse, and the difficulty to successfully target areas that were functionally defined by fMRI. Here we describe a methodology for combining these three common tools: TMS, EEG, and fMRI. We explain how to guide the stimulator's coil to the desired target area using anatomical or functional MRI data, how to record EEG during concurrent TMS, how to design an ERP study suitable for EEG-TMS combination and how to extract reliable ERP from the recorded data. We will provide representative results from a previously published study, in which fMRI-guided TMS was used concurrently with EEG to show that the face-selective N1 and the body-selective N1 component of the ERP are associated with distinct neural networks in extrastriate cortex. This method allows us to combine the high spatial resolution of fMRI with the high temporal resolution of TMS and EEG and therefore obtain a comprehensive understanding of the neural basis of various cognitive processes. PMID:24893706

Rotation in a reversed field pinch with active feedback stabilization of resistive wall modes

NASA Astrophysics Data System (ADS)

Cecconello, M.; Menmuir, S.; Brunsell, P. R.; Kuldkepp, M.

2006-09-01

Active feedback stabilization of multiple resistive wall modes (RWMs) has been successfully proven in the EXTRAP T2R reversed field pinch. One of the features of plasma discharges operated with active feedback stabilization, in addition to the prolongation of the plasma discharge, is the sustainment of the plasma rotation. Sustained rotation is observed both for the internally resonant tearing modes (TMs) and the intrinsic impurity oxygen ions. Good quantitative agreement between the toroidal rotation velocities of both is found: the toroidal rotation is characterized by an acceleration phase followed, after one wall time, by a deceleration phase that is slower than in standard discharges. The TMs and the impurity ions rotate in the same poloidal direction with also similar velocities. Poloidal and toroidal velocities have comparable amplitudes and a simple model of their radial profile reproduces the main features of the helical angular phase velocity. RWMs feedback does not qualitatively change the TMs behaviour and typical phenomena such as the dynamo and the 'slinky' are still observed. The improved sustainment of the plasma and TMs rotation occurs also when feedback only acts on internally non-resonant RWMs. This may be due to an indirect positive effect, through non-linear coupling between TMs and RWMs, of feedback on the TMs or to a reduced plasma-wall interaction affecting the plasma flow rotation. Electromagnetic torque calculations show that with active feedback stabilization the TMs amplitude remains well below the locking threshold condition for a thick shell. Finally, it is suggested that active feedback stabilization of RWMs and current profile control techniques can be employed simultaneously thus improving both the plasma duration and its confinement properties.

Corticospinal excitability measurements using transcranial magnetic stimulation are valid with intramuscular electromyography.

PubMed

Summers, Rebekah L S; Chen, Mo; Kimberley, Teresa J

2017-01-01

Muscular targets that are deep or inaccessible to surface electromyography (sEMG) require intrinsic recording using fine-wire electromyography (fEMG). It is unknown if fEMG validly record cortically evoked muscle responses compared to sEMG. The purpose of this investigation was to establish the validity and agreement of fEMG compared to sEMG to quantify typical transcranial magnetic stimulation (TMS) measures pre and post repetitive TMS (rTMS). The hypotheses were that fEMG would demonstrate excellent validity and agreement compared with sEMG. In ten healthy volunteers, paired pulse and cortical silent period (CSP) TMS measures were collected before and after 1200 pulses of 1Hz rTMS to the motor cortex. Data were simultaneously recorded with sEMG and fEMG in the first dorsal interosseous. Concurrent validity (r and rho) and agreement (Tukey mean-difference) were calculated. fEMG quantified corticospinal excitability with good to excellent validity compared to sEMG data at both pretest (r = 0.77-0.97) and posttest (r = 0.83-0.92). Pairwise comparisons indicated no difference between sEMG and fEMG for all outcomes; however, Tukey mean-difference plots display increased variance and questionable agreement for paired pulse outcomes. CSP displayed the highest estimates of validity and agreement. Paired pulse MEP responses recorded with fEMG displayed reduced validity, agreement and less sensitivity to changes in MEP amplitude compared to sEMG. Change scores following rTMS were not significantly different between sEMG and fEMG. fEMG electrodes are a valid means to measure CSP and paired pulse MEP responses. CSP displays the highest validity estimates, while caution is warranted when assessing paired pulse responses with fEMG. Corticospinal excitability and neuromodulatory aftereffects from rTMS may be assessed using fEMG.

Establishing the functional connectivity of the frontotemporal network in pre-attentive change detection with Transcranial Magnetic Stimulation and event-related optical signal.

PubMed

Tse, Chun-Yu; Long-Yin, Yip; Lui, Troby Ka-Yan; Xiao, Xue-Zhen; Wang, Yang; Chu, Winnie Chiu Wing; Parks, Nathan Allen; Chan, Sandra Sau-Man; Neggers, Sebastiaan Franciscus Wijnandus

2018-06-18

Current theories of pre-attentive deviant detection postulate that before the Superior Temporal Cortex (STC) detects a change, the Inferior Frontal Cortex (IFC) engages in stimulus analysis, which is particularly critical for ambiguous deviations (e.g., deviant preceded by a short train of standards). These theories rest on the assumption that IFC and STC are functionally connected, which has only been supported by correlational brain imaging studies. We examined this functional connectivity assumption by applying Transcranial Magnetic Stimulation (TMS) to disrupt IFC function, while measuring the later STC mismatch response with the event-related optical signal (EROS). EROS can localize brain activity in both spatial and temporal dimensions via measurement of optical property changes associated with neuronal activity, and is inert to the electromagnetic interference produced by TMS. Specifically, the STC mismatch response at 120-180 ms elicited by a deviant preceded by a short standard train when IFC TMS was applied at 80 ms was compared with the STC mismatch responses in temporal control (TMS with 200 ms delay), spatial control (sham TMS at vertex), auditory control (TMS pulse noise only), and cognitive control (deviant preceded by a long standard train) conditions. The STC mismatch response to deviants preceded by the short train was abolished by TMS of the IFC at 80 ms, while the STC responses remained intact in all other control conditions. These results confirm the involvement of the IFC in the STC mismatch response and support a functional connection between IFC and STC. Copyright © 2018. Published by Elsevier Inc.

Downregulation of tropomyosin-1 in squamous cell carcinoma of esophagus, the role of Ras signaling and methylation.

PubMed

Zare, Maryam; Jazii, Ferdous Rastgar; Soheili, Zahra-Soheila; Moghanibashi, Mohamad-Mehdi

2012-10-01

Tropomyosins (TMs) are a family of cytoskeletal proteins that bind to and stabilize actin microfilaments. Non-muscle cells express multiple isoforms of TMs including three high molecular weight (HMW) isoforms: TM1, TM2, and TM3. While reports have indicated downregulation of TMs in transformed cells and several human cancers, nevertheless, little is known about the underlying mechanism of TMs suppression. In present study the expression of HMW TMs was investigated in squamous cell carcinoma of esophagus (SCCE), relative to primary cell cultures of normal esophagus by western blotting and real-time RT-PCR. Our results showed that TM1, TM2, and TM3 were significantly downregulated in cell line of SCCE. Moreover, mRNA level of TPM1 and TPM2 were markedly decreased by 93% and 96%, in tumor cell line relative to esophagus normal epithelial cells. Therefore, downregulation of TMs could play an important role in tumorigenesis of esophageal cancer. To asses the mechanism of TM downregulation in esophageal cancer, the role of Ras dependent signaling and promoter hypermethylation were investigated. We found that inhibition of two Ras effectory downstream pathways; MEK/ERK and PI3K/Akt leads to significant increased expression of TM1 protein and both TPM1 and TPM2 mRNAs. In addition, methyltransferase inhibition significantly upregulated TM1, suggesting the prominent contribution of promoter hypermethylation in TM1 downregulation in esophageal cancer. These data indicate that downregulation of HMW TMs occurs basically in SCCE and the activation of MEK/ERK and PI3K/Akt pathways as well as the epigenetic mechanism of promoter hypermethylation play important role in TM1 suppression in SCCE. Copyright © 2011 Wiley Periodicals, Inc.

Impairment of preoperative language mapping by lesion location: a functional magnetic resonance imaging, navigated transcranial magnetic stimulation, and direct cortical stimulation study.

PubMed

Ille, Sebastian; Sollmann, Nico; Hauck, Theresa; Maurer, Stefanie; Tanigawa, Noriko; Obermueller, Thomas; Negwer, Chiara; Droese, Doris; Boeckh-Behrens, Tobias; Meyer, Bernhard; Ringel, Florian; Krieg, Sandro M

2015-08-01

Language mapping by repetitive navigated transcranial magnetic stimulation (rTMS) is increasingly used and has already replaced functional MRI (fMRI) in some institutions for preoperative mapping of neurosurgical patients. Yet some factors affect the concordance of both methods with direct cortical stimulation (DCS), most likely by lesions affecting cortical oxygenation levels. Therefore, the impairment of the accuracy of rTMS and fMRI was analyzed and compared with DCS during awake surgery in patients with intraparenchymal lesions. Language mapping was performed by DCS, rTMS, and fMRI using an object-naming task in 27 patients with left-sided perisylvian lesions, and the induced language errors of each method were assigned to the cortical parcellation system. Subsequently, the receiver operating characteristics were calculated for rTMS and fMRI and compared with DCS as ground truth for regions with (w/) and without (w/o) the lesion in the mapped regions. The w/ subgroup revealed a sensitivity of 100% (w/o 100%), a specificity of 8% (w/o 5%), a positive predictive value of 34% (w/o: 53%), and a negative predictive value (NPV) of 100% (w/o: 100%) for the comparison of rTMS versus DCS. Findings for the comparison of fMRI versus DCS within the w/ subgroup revealed a sensitivity of 32% (w/o: 62%), a specificity of 88% (w/o: 60%), a positive predictive value of 56% (w/o: 62%), and a NPV of 73% (w/o: 60%). Although strengths and weaknesses exist for both rTMS and fMRI, the results show that rTMS is less affected by a brain lesion than fMRI, especially when performing mapping of language-negative cortical regions based on sensitivity and NPV.

Cost-effectiveness of preoperative motor mapping with navigated transcranial magnetic brain stimulation in patients with high-grade glioma.

PubMed

Butenschön, Vicki M; Ille, Sebastian; Sollmann, Nico; Meyer, Bernhard; Krieg, Sandro M

2018-06-01

OBJECTIVE Navigated transcranial magnetic stimulation (nTMS) is used to identify the motor cortex prior to surgery. Yet, there has, until now, been no published evidence on the economic impact of nTMS. This study aims to analyze the cost-effectiveness of nTMS, evaluating the incremental costs of nTMS motor mapping per additional quality-adjusted life year (QALY). By doing so, this study also provides a model allowing for future analysis of general cost-effectiveness of new neuro-oncological treatment options. METHODS The authors used a microsimulation model based on their cohort population sampled for 1000 patients over the time horizon of 2 years. A health care provider perspective was used to assemble direct costs of total treatment. Transition probabilities and health utilities were based on published literature. Effects were stated in QALYs and established for health state subgroups. RESULTS In all scenarios, preoperative mapping was considered cost-effective with a willingness-to-pay threshold < 3*per capita GDP (gross domestic product). The incremental cost-effectiveness ratio (ICER) of nTMS versus no nTMS was 45,086 Euros/QALY. Sensitivity analyses showed robust results with a high impact of total treatment costs and utility of progression-free survival. Comparing the incremental costs caused by nTMS implementation only, the ICER decreased to 1967 Euros/QALY. CONCLUSIONS Motor mapping prior to surgery provides a cost-effective tool to improve the clinical outcome and overall survival of high-grade glioma patients in a resource-limited setting. Moreover, the model used in this study can be used in the future to analyze new treatment options in neuro-oncology in terms of their general cost-effectiveness.

The effect of rTMS over the inferior parietal lobule on EEG sensorimotor reactivity differs according to self-reported traits of autism in typically developing individuals.

PubMed

Puzzo, Ignazio; Cooper, Nicholas R; Cantarella, Simona; Fitzgerald, Paul B; Russo, Riccardo

2013-12-06

Previous research suggested that EEG markers of mirror neuron system activation may differ, in the normal population as a function of different levels of the autistic spectrum quotient; (AQ). The present study aimed at modulating the EEG sensorimotor reactivity induced by hand movement observation by means of repetitive transcranial magnetic stimulation (rTMS) applied to the inferior parietal lobule. We examined how the resulting rTMS modulation differed in relation to the self-reported autistic traits in the typically developing population. Results showed that during sham stimulation, all participants had significantly greater sensorimotor alpha reactivity (motor cortex-C electrodes) when observing hand movements compared to static hands. This sensorimotor alpha reactivity difference was reduced during active rTMS stimulation. Results also revealed that in the average AQ group at sham there was a significant increase in low beta during hand movement than static hand observation (pre-motor areas-FC electrodes) and that (like alpha over the C electrodes) this difference is abolished when active rTMS is delivered. Participants with high AQ scores showed no significant difference in low beta sensorimotor reactivity between active and sham rTMS during static hand or hand movement observation. These findings suggest that unlike sham, active rTMS over the IPL modulates the oscillatory activity of the low beta frequency of a distal area, namely the anterior sector of the sensorimotor cortex, when participants observe videos of static hand. Importantly, this modulation differs according to the degree of self-reported traits of autism in a typically developing population. © 2013 Elsevier B.V. All rights reserved.

Lamotrigine and levetiracetam exert a similar modulation of TMS-evoked EEG potentials.

PubMed

Premoli, Isabella; Biondi, Andrea; Carlesso, Sara; Rivolta, Davide; Richardson, Mark P

2017-01-01

Antiepileptic drug (AED) treatment failures may occur because there is insufficient drug in the brain or because of a lack of relevant therapeutic response. Until now it has not been possible to measure these factors. It has been recently shown that the combination of transcranial magnetic stimulation and electroencephalography (TMS-EEG) can measure the effects of drugs in healthy volunteers. TMS-evoked EEG potentials (TEPs) comprise a series of positive and negative deflections that can be specifically modulated by drugs with a well-known mode of action targeting inhibitory neurotransmission. Therefore, we hypothesized that TMS-EEG can detect effects of two widely used AEDs, lamotrigine and levetiracetam, in healthy volunteers. Fifteen healthy subjects participated in a pseudo-randomized, placebo-controlled, double-blind, crossover design, using a single oral dose of lamotrigine (300 mg) and levetiracetam (3,000 mg). TEPs were recorded before and 120 min after drug intake, and the effects of drugs on the amplitudes of TEP components were statistically evaluated. A nonparametric cluster-based permutation analysis of TEP amplitudes showed that AEDs both increased the amplitude of the negative potential at 45 msec after stimulation (N45) and suppressed the positive peak at 180 msec (P180). This is the first demonstration of AED-induced modulation of TMS-EEG measures. Despite the different mechanism of action that lamotrigine and levetiracetam exert at the molecular level, both AEDs impact the TMS-EEG response in a similar way. These TMS-EEG fingerprints observed in healthy subjects are candidate predictive markers of treatment response in patients on monotherapy with lamotrigine and levetiracetam. © 2016 The Authors. Epilepsia published by Wiley Periodicals, Inc. on behalf of International League Against Epilepsy.

Brain stimulation and constraint for perinatal stroke hemiparesis

PubMed Central

Andersen, John; Herrero, Mia; Nettel-Aguirre, Alberto; Carsolio, Lisa; Damji, Omar; Keess, Jamie; Mineyko, Aleksandra; Hodge, Jacquie; Hill, Michael D.

2016-01-01

Objective: To determine whether the addition of repetitive transcranial magnetic stimulation (rTMS) and/or constraint-induced movement therapy (CIMT) to intensive therapy increases motor function in children with perinatal stroke and hemiparesis. Methods: A factorial-design, blinded, randomized controlled trial (clinicaltrials.gov/NCT01189058) assessed rTMS and CIMT effects in hemiparetic children (aged 6–19 years) with MRI-confirmed perinatal stroke. All completed a 2-week, goal-directed, peer-supported motor learning camp randomized to daily rTMS, CIMT, both, or neither. Primary outcomes were the Assisting Hand Assessment and the Canadian Occupational Performance Measure at baseline, and 1 week, 2 and 6 months postintervention. Outcome assessors were blinded to treatment. Interim safety analyses occurred after 12 and 24 participants. Intention-to-treat analysis examined treatment effects over time (linear mixed effects model). Results: All 45 participants completed the trial. Addition of rTMS, CIMT, or both doubled the chances of clinically significant improvement. Assisting Hand Assessment gains at 6 months were additive and largest with rTMS + CIMT (β coefficient = 5.54 [2.57–8.51], p = 0.0004). The camp alone produced large improvements in Canadian Occupational Performance Measure scores, maximal at 6 months (Cohen d = 1.6, p = 0.002). Quality-of-life scores improved. Interventions were well tolerated and safe with no decrease in function of either hand. Conclusions: Hemiparetic children participating in intensive, psychosocial rehabilitation programs can achieve sustained functional gains. Addition of CIMT and rTMS increases the chances of improvement. Classification of evidence: This study provides Class II evidence that combined rTMS and CIMT enhance therapy-induced functional motor gains in children with stroke-induced hemiparetic cerebral palsy. PMID:27029628

The effects of combined repetitive transcranial magnetic stimulation and transcranial direct current stimulation on motor function in patients with stroke.

PubMed

Kwon, Tae Gun; Park, Eunhee; Kang, Chung; Chang, Won Hyuk; Kim, Yun-Hee

2016-11-22

Both transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), when provided to stroke patients in combination with motor training, enhance therapeutic efficacy and motor function. However, the majority of previous studies have only examined a single treatment modality. The authors investigated the modulating influence of combination dual-mode brain stimulation upon bihemispheric stimulation with motor training in stroke patients. Twenty stroke patients with hemiparesis underwent five randomly arranged sessions of diverse combinations of rTMS and tDCS. We applied cathodal or anodal tDCS over the contralesional primary motor cortex (cM1) and 10 Hz rTMS over the ipsilesional primary motor cortex (iM1) in a simultaneous or preconditioning method including sham stimulation. Immediately after dual-mode stimulation, sequential hand motor training was performed for 5 minutes. The total pulses of rTMS and the duration of tDCS and motor training were the same for all sessions. Cortical excitability and sequential motor performance were evaluated before and after each session. Motor function and corticomotor excitability following simultaneous stimulation via cathodal tDCS over the cM1 combined with 10 Hz rTMS over the iM1 were significantly increased after the intervention, with significantly greater motor improvement than seen with other treatment conditions (P < 0.05). For the combination of bihemispheric rTMS and tDCS, simultaneous stimulation of cathodal tDCS and 10 Hz rTMS results in better motor performance in stroke patients than other combination methods. This result seemed to be related to effective modulation of interhemispheric imbalance of cortical excitability by dual-mode stimulation.

Ethanol modulates cortical activity: direct evidence with combined TMS and EEG.

PubMed

Kähkönen, S; Kesäniemi, M; Nikouline, V V; Karhu, J; Ollikainen, M; Holi, M; Ilmoniemi, R J

2001-08-01

The motor cortex of 10 healthy subjects was stimulated by transcranial magnetic stimulation (TMS) before and after ethanol challenge (0.8 g/kg resulting in blood concentration of 0.77 +/- 0.14 ml/liter). The electrical brain activity resulting from the brief electromagnetic pulse was recorded with high-resolution electroencephalography (EEG) and located using inversion algorithms. Focal magnetic pulses to the left motor cortex were delivered with a figure-of-eight coil at the random interstimulus interval of 1.5-2.5 s. The stimulation intensity was adjusted to the motor threshold of abductor digiti minimi. Two conditions before and after ethanol ingestion (30 min) were applied: (1) real TMS, with the coil pressed against the scalp; and (2) control condition, with the coil separated from the scalp by a 2-cm-thick piece of plastic. A separate EMG control recording of one subject during TMS was made with two bipolar platinum needle electrodes inserted to the left temporal muscle. In each condition, 120 pulses were delivered. The EEG was recorded from 60 scalp electrodes. A peak in the EEG signals was observed at 43 ms after the TMS pulse in the real-TMS condition but not in the control condition or in the control scalp EMG. Potential maps before and after ethanol ingestion were significantly different from each other (P = 0.01), but no differences were found in the control condition. Ethanol changed the TMS-evoked potentials over right frontal and left parietal areas, the underlying effect appearing to be largest in the right prefrontal area. Our findings suggest that ethanol may have changed the functional connectivity between prefrontal and motor cortices. This new noninvasive method provides direct evidence about the modulation of cortical connectivity after ethanol challenge. Copyright 2001 Academic Press.

Towards assessing corticospinal excitability bilaterally: Validation of a double-coil TMS method.

PubMed

Grandjean, Julien; Derosiere, Gerard; Vassiliadis, Pierre; Quemener, Louise; Wilde, Ysaline de; Duque, Julie

2018-01-01

For several decades, Transcranial magnetic stimulation (TMS) has been used to monitor corticospinal excitability (CSE) changes in various contexts. Habitually, single-coil TMS is applied over one primary motor cortex (M1), eliciting motor-evoked potentials (MEPs) in a contralateral limb muscle, usually a hand effector. However, in many situations, it would be useful to obtain MEPs in both hands simultaneously, to track CSE bilaterally. Such an approach requires stimulating both M1 concurrently while avoiding interference between the two descending stimuli. We examined MEPs obtained at rest using a double-coil TMS approach where the two M1 are stimulated with a 1ms inter-pulse interval (double-coil 1ms ). MEPs were acquired using double-coil 1ms (MEP double ) or single-coil (MEP single ) TMS, at five different intensities of stimulation (100, 115, 130, 145 or 160% of the resting motor threshold, rMT). Given the 1ms inter-pulse interval in double-coil 1ms trials, MEP double were either evoked by a 1st (MEP double-1 ) or a 2nd (MEP double-2 ) TMS pulse. All MEP TYPE (MEP TYPE =MEP single , MEP double-1 and MEP double-2 ) were equivalent, regardless of the hand within which they were elicited, the intensity of stimulation or the pulse order. This method allows one to observe state-related CSE changes for the two hands simultaneously on a trial-by-trial basis. These results infer the absence of any neural interactions between the two cortico-spinal volleys with double-coil 1ms TMS. Hence, this technique can be reliably used to assess CSE bilaterally, opening new research perspectives for scientists interested in physiological markers of activity in the motor output system. Copyright © 2017 Elsevier B.V. All rights reserved.

Follow-up study of children whose mothers were treated with transcranial magnetic stimulation during pregnancy: preliminary results.

PubMed

Eryılmaz, Gul; Sayar, Gökben Hızlı; Özten, Eylem; Gül, Işıl Göğcegöz; Yorbik, Özgür; Işiten, Nuket; Bağcı, Eda

2015-06-01

The purpose of this study is to determine the impact of repetitive transcranial stimulation (rTMS) treatment during pregnancy on neurodevelopment of children. Women who were treated with rTMS during pregnancy and delivered liveborn children between 2008 and 2013 were selected. A control group consisted of children whose mothers had a history of untreated depression during their pregnancy (N = 26). Early developmental characteristics of all the children in the study were evaluated, and their developmental levels were determined using the Ankara Developmental Screening Inventory. The mean age of the children in the rTMS treatment group was 32.4 months (range 16-64 months), and that of the untreated group was 29.04 (range 14-63 months). Jaundice (N = 2) and febrile convulsion (N = 1) were the reported medical conditions in the children of the rTMS-treated group; jaundice (N = 3) and low birth weight (N = 1) were reported in the untreated group. In the rTMS group, mothers' perception of delay in language development was observed, but there were not any statistically significant differences in the prevalence rate compared with the untreated group (OR = 0.38; 95% CI 0.0860-1.6580). Our results suggest that rTMS exposure during pregnancy is not associated with poorer cognitive or motor development outcomes in children aged 18-62 months. Although language development as reported by the mothers was found to be poorer than expected in the rTMS-treated group, the delay was found to be similar to the language delay observed in offspring of untreated mothers, as reported in previous studies of prenatal depression treated with selective serotonin reuptake inhibitors. © 2014 International Neuromodulation Society.

Brain stimulation and constraint for perinatal stroke hemiparesis: The PLASTIC CHAMPS Trial.

PubMed

Kirton, Adam; Andersen, John; Herrero, Mia; Nettel-Aguirre, Alberto; Carsolio, Lisa; Damji, Omar; Keess, Jamie; Mineyko, Aleksandra; Hodge, Jacquie; Hill, Michael D

2016-05-03

To determine whether the addition of repetitive transcranial magnetic stimulation (rTMS) and/or constraint-induced movement therapy (CIMT) to intensive therapy increases motor function in children with perinatal stroke and hemiparesis. A factorial-design, blinded, randomized controlled trial (clinicaltrials.gov/NCT01189058) assessed rTMS and CIMT effects in hemiparetic children (aged 6-19 years) with MRI-confirmed perinatal stroke. All completed a 2-week, goal-directed, peer-supported motor learning camp randomized to daily rTMS, CIMT, both, or neither. Primary outcomes were the Assisting Hand Assessment and the Canadian Occupational Performance Measure at baseline, and 1 week, 2 and 6 months postintervention. Outcome assessors were blinded to treatment. Interim safety analyses occurred after 12 and 24 participants. Intention-to-treat analysis examined treatment effects over time (linear mixed effects model). All 45 participants completed the trial. Addition of rTMS, CIMT, or both doubled the chances of clinically significant improvement. Assisting Hand Assessment gains at 6 months were additive and largest with rTMS + CIMT (β coefficient = 5.54 [2.57-8.51], p = 0.0004). The camp alone produced large improvements in Canadian Occupational Performance Measure scores, maximal at 6 months (Cohen d = 1.6, p = 0.002). Quality-of-life scores improved. Interventions were well tolerated and safe with no decrease in function of either hand. Hemiparetic children participating in intensive, psychosocial rehabilitation programs can achieve sustained functional gains. Addition of CIMT and rTMS increases the chances of improvement. This study provides Class II evidence that combined rTMS and CIMT enhance therapy-induced functional motor gains in children with stroke-induced hemiparetic cerebral palsy. © 2016 American Academy of Neurology.

Prefrontal rTMS for treating depression: location and intensity results from the OPT-TMS multi-site clinical trial.

PubMed

Johnson, Kevin A; Baig, Mirza; Ramsey, Dave; Lisanby, Sarah H; Avery, David; McDonald, William M; Li, Xingbao; Bernhardt, Elisabeth R; Haynor, David R; Holtzheimer, Paul E; Sackeim, Harold A; George, Mark S; Nahas, Ziad

2013-03-01

Motor cortex localization and motor threshold determination often guide Transcranial Magnetic Stimulation (TMS) placement and intensity settings for non-motor brain stimulation. However, anatomic variability results in variability of placement and effective intensity. Post-study analysis of the OPT-TMS Study reviewed both the final positioning and the effective intensity of stimulation (accounting for relative prefrontal scalp-cortex distances). We acquired MRI scans of 185 patients in a multi-site trial of left prefrontal TMS for depression. Scans had marked motor sites (localized with TMS) and marked prefrontal sites (5 cm anterior of motor cortex by the "5 cm rule"). Based on a visual determination made before the first treatment, TMS therapy occurred either at the 5 cm location or was adjusted 1 cm forward. Stimulation intensity was 120% of resting motor threshold. The "5 cm rule" would have placed stimulation in premotor cortex for 9% of patients, which was reduced to 4% with adjustments. We did not find a statistically significant effect of positioning on remission, but no patients with premotor stimulation achieved remission (0/7). Effective stimulation ranged from 93 to 156% of motor threshold, and no seizures were induced across this range. Patients experienced remission with effective stimulation intensity ranging from 93 to 146% of motor threshold, and we did not find a significant effect of effective intensity on remission. Our data indicates that individualized positioning methods are useful to reduce variability in placement. Stimulation at 120% of motor threshold, unadjusted for scalp-cortex distances, appears safe for a broad range of patients. Copyright © 2013 Elsevier Inc. All rights reserved.

Causal Influence of Articulatory Motor Cortex on Comprehending Single Spoken Words: TMS Evidence.

PubMed

Schomers, Malte R; Kirilina, Evgeniya; Weigand, Anne; Bajbouj, Malek; Pulvermüller, Friedemann

2015-10-01

Classic wisdom had been that motor and premotor cortex contribute to motor execution but not to higher cognition and language comprehension. In contrast, mounting evidence from neuroimaging, patient research, and transcranial magnetic stimulation (TMS) suggest sensorimotor interaction and, specifically, that the articulatory motor cortex is important for classifying meaningless speech sounds into phonemic categories. However, whether these findings speak to the comprehension issue is unclear, because language comprehension does not require explicit phonemic classification and previous results may therefore relate to factors alien to semantic understanding. We here used the standard psycholinguistic test of spoken word comprehension, the word-to-picture-matching task, and concordant TMS to articulatory motor cortex. TMS pulses were applied to primary motor cortex controlling either the lips or the tongue as subjects heard critical word stimuli starting with bilabial lip-related or alveolar tongue-related stop consonants (e.g., "pool" or "tool"). A significant cross-over interaction showed that articulatory motor cortex stimulation delayed comprehension responses for phonologically incongruent words relative to congruous ones (i.e., lip area TMS delayed "tool" relative to "pool" responses). As local TMS to articulatory motor areas differentially delays the comprehension of phonologically incongruous spoken words, we conclude that motor systems can take a causal role in semantic comprehension and, hence, higher cognition. © The Author 2014. Published by Oxford University Press.

Low-frequency rTMS with language therapy over a 3-month period for sensory-dominant aphasia: case series of two post-stroke Japanese patients.

PubMed

Kakuda, Wataru; Abo, Masahiro; Uruma, Go; Kaito, Nobuyoshi; Watanabe, Motoi

2010-01-01

To examine the safety and feasibility of therapeutic application of low-frequency repetitive transcranial magnetic stimulation (rTMS) combined with language therapy for post-stroke patients with sensory-dominant aphasia. Two post-stroke Japanese patients with sensory-dominant aphasia were studied. In both patients, 10 sessions of 20-minute low-frequency rTMS with 1 Hz to the Wernicke's area were provided throughout 6-day hospitalization, followed by weekly outpatient rTMS treatment for 3 months. The language therapy was also provided through the period of in- and out-patient treatment. Language function was evaluated using the Token test and the Standard Language Test of Aphasia (SLTA) at the start and end of the in-patient treatment and the end of the outpatient treatment. The therapeutic protocol was well tolerated throughout the in- and out-patient treatments, without any adverse effects. The scores of the Token test and certain sub-categories of SLTA increased in both patients after the in-patient rTMS treatment. Persistent improvement of the score was noted over the 3-month post-discharge period. The proposed protocol of long-term application of low-frequency rTMS to the Wernicke's area and language therapy is considered a safe and feasible therapeutic approach for post-stroke patients with sensory-dominant aphasia.

Whole-brain haemodynamic after-effects of 1-Hz magnetic stimulation of the posterior superior temporal cortex during action observation.

PubMed

Arfeller, Carola; Schwarzbach, Jens; Ubaldi, Silvia; Ferrari, Paolo; Barchiesi, Guido; Cattaneo, Luigi

2013-04-01

The posterior superior temporal sulcus (pSTS) is active when observing biological motion. We investigated the functional connections of the pSTS node within the action observation network by measuring the after-effect of focal repetitive transcranial magnetic stimulation (rTMS) with whole-brain functional magnetic resonance imaging (fMRI). Participants received 1-Hz rTMS over the pSTS region for 10 min and underwent fMRI immediately after. While scanned, they were shown short video clips of a hand grasping an object (grasp clips) or moving next to it (control clips). rTMS-fMRI was repeated for four consecutive blocks. In two blocks we stimulated the left pSTS region and in the other two the right pSTS region. For each side TMS was applied with an effective intensity (95 % of motor threshold) or with ineffective intensity (50 % of motor threshold). Brain regions showing interactive effects of (clip type) × (TMS intensity) were identified in the lateral temporo-occipital cortex, in the anterior intraparietal region and in the ventral premotor cortex. Remote effects of rTMS were mostly limited to the stimulated hemisphere and consisted in an increase of blood oxygen level-dependent responses to grasp clips compared to control clips. We show that the pSTS occupies a pivotal relay position during observation of goal-directed actions.

Causal Influence of Articulatory Motor Cortex on Comprehending Single Spoken Words: TMS Evidence

PubMed Central

Schomers, Malte R.; Kirilina, Evgeniya; Weigand, Anne; Bajbouj, Malek; Pulvermüller, Friedemann

2015-01-01

Classic wisdom had been that motor and premotor cortex contribute to motor execution but not to higher cognition and language comprehension. In contrast, mounting evidence from neuroimaging, patient research, and transcranial magnetic stimulation (TMS) suggest sensorimotor interaction and, specifically, that the articulatory motor cortex is important for classifying meaningless speech sounds into phonemic categories. However, whether these findings speak to the comprehension issue is unclear, because language comprehension does not require explicit phonemic classification and previous results may therefore relate to factors alien to semantic understanding. We here used the standard psycholinguistic test of spoken word comprehension, the word-to-picture-matching task, and concordant TMS to articulatory motor cortex. TMS pulses were applied to primary motor cortex controlling either the lips or the tongue as subjects heard critical word stimuli starting with bilabial lip-related or alveolar tongue-related stop consonants (e.g., “pool” or “tool”). A significant cross-over interaction showed that articulatory motor cortex stimulation delayed comprehension responses for phonologically incongruent words relative to congruous ones (i.e., lip area TMS delayed “tool” relative to “pool” responses). As local TMS to articulatory motor areas differentially delays the comprehension of phonologically incongruous spoken words, we conclude that motor systems can take a causal role in semantic comprehension and, hence, higher cognition. PMID:25452575

Dissociation of neural mechanisms underlying orientation processing in humans

PubMed Central

Ling, Sam; Pearson, Joel; Blake, Randolph

2009-01-01

Summary Orientation selectivity is a fundamental, emergent property of neurons in early visual cortex, and discovery of that property [1, 2] dramatically shaped how we conceptualize visual processing [3–6]. However, much remains unknown about the neural substrates of these basic building blocks of perception, and what is known primarily stems from animal physiology studies. To probe the neural concomitants of orientation processing in humans, we employed repetitive transcranial magnetic stimulation (rTMS) to attenuate neural responses evoked by stimuli presented within a local region of the visual field. Previous physiological studies have shown that rTMS can significantly suppress the neuronal spiking activity, hemodynamic responses, and local field potentials within a focused cortical region [7, 8]. By suppressing neural activity with rTMS, we were able to dissociate components of the neural circuitry underlying two distinct aspects of orientation processing: selectivity and contextual effects. Orientation selectivity gauged by masking was unchanged by rTMS, whereas an otherwise robust orientation repulsion illusion was weakened following rTMS. This dissociation implies that orientation processing relies on distinct mechanisms, only one of which was impacted by rTMS. These results are consistent with models positing that orientation selectivity is largely governed by the patterns of convergence of thalamic afferents onto cortical neurons, with intracortical activity then shaping population responses contained within those orientation-selective cortical neurons. PMID:19682905

Treatment for Traumatic Brain Injury in Mice Using Transcranial Magnetic Stimulation: A Preliminary Study

NASA Astrophysics Data System (ADS)

Carr, Alexandria; Zenitsky, Gary; Crowther, Lawrence; Hadimani, Ravi; Anantharam, Vellareddy; Kanthasamy, Anumantha; Jiles, David

2014-03-01

Transcranial magnetic stimulation (TMS) is a non-invasive surgery-free tool used to stimulate the brain by time-varying magnetic fields. TMS is currently being investigated as a treatment for neurological disorders such as depression, Parkinson's disease and TBI. Before moving to human TMS/TBI trials, animal testing should be pursued to determine suitability and adverse effects. As an initial study, four healthy mice were treated with TMS at different power levels to determine short-term behavioral effects and set a control group baseline. The mouse's behavior was studied using the Rotorod test, which measures the animal's latency to fall off a rotating rod, and the Versamax test, which measures horizontal and vertical movement, and total distance traveled. The Rotorod test has shown for TMS power levels >=90% the mice begin to fall directly post-treatment. Similarly, the Versamax test has shown for power levels >=80% the mice are less mobile directly post-treatment. Versamax mobility was found to return to normal the day following treatment. These mice were housed in the facility for 4 months and the behavioral tests were repeated. Versamax results showed there was no significant variation in mobility indicating there are no long-term side effects of TMS treatment on the mice. This work was supported by the Barbara and James Palmer Endowment and the Carver Charitable Trust at the Department of Electrical and Computer Engineering, Iowa State University.

Single-Scale Retinex Using Digital Signal Processors

NASA Technical Reports Server (NTRS)

Hines, Glenn; Rahman, Zia-Ur; Jobson, Daniel; Woodell, Glenn

2005-01-01

The Retinex is an image enhancement algorithm that improves the brightness, contrast and sharpness of an image. It performs a non-linear spatial/spectral transform that provides simultaneous dynamic range compression and color constancy. It has been used for a wide variety of applications ranging from aviation safety to general purpose photography. Many potential applications require the use of Retinex processing at video frame rates. This is difficult to achieve with general purpose processors because the algorithm contains a large number of complex computations and data transfers. In addition, many of these applications also constrain the potential architectures to embedded processors to save power, weight and cost. Thus we have focused on digital signal processors (DSPs) and field programmable gate arrays (FPGAs) as potential solutions for real-time Retinex processing. In previous efforts we attained a 21 (full) frame per second (fps) processing rate for the single-scale monochromatic Retinex with a TMS320C6711 DSP operating at 150 MHz. This was achieved after several significant code improvements and optimizations. Since then we have migrated our design to the slightly more powerful TMS320C6713 DSP and the fixed point TMS320DM642 DSP. In this paper we briefly discuss the Retinex algorithm, the performance of the algorithm executing on the TMS320C6713 and the TMS320DM642, and compare the results with the TMS320C6711.

Transfer of motor learning engages specific neural substrates during motor memory consolidation dependent on the practice structure.

PubMed

Kantak, Shailesh S; Sullivan, Katherine J; Fisher, Beth E; Knowlton, Barbara J; Winstein, Carolee J

2011-01-01

The authors investigated how brain activity during motor-memory consolidation contributes to transfer of learning to novel versions of a motor skill following distinct practice structures. They used 1 Hz repetitive Transcranial Magnetic Stimulation (rTMS) immediately after constant or variable practice of an arm movement skill to interfere with primary motor cortex (M1) or dorsolateral prefrontal cortex (DLPFC). The effect of interference was assessed through skill performance on two transfer targets: one within and one outside the range of practiced movement parameters for the variable practice group. For the control (no rTMS) group, variable practice benefited delayed transfer performance more than constant practice. The rTMS effect on delayed transfer performance differed for the two transfer targets. For the within-range target, rTMS interference had no significant affect on the delayed transfer after either practice structure. However, for the outside-range target, rTMS interference to DLPFC but not M1 attenuated delayed transfer benefit following variable practice. Additionally, for the outside-range target, rTMS interference to M1 but not DLPFC attenuated delayed transfer following constant practice. This suggests that variable practice may promote reliance on DLPFC for memory consolidation associated with outside-range transfer of learning, whereas constant practice may promote reliance on M1 for consolidation and long-term transfer.

Transcranial magnetic stimulation in developmental stuttering: Relations with previous neurophysiological research and future perspectives.

PubMed

Busan, P; Battaglini, P P; Sommer, M

2017-06-01

Developmental stuttering (DS) is a disruption of the rhythm of speech, and affected people may be unable to execute fluent voluntary speech. There are still questions about the exact causes of DS. Evidence suggests there are differences in the structure and functioning of motor systems used for preparing, executing, and controlling motor acts, especially when they are speech related. Much research has been obtained using neuroimaging methods, ranging from functional magnetic resonance to diffusion tensor imaging and electroencephalography/magnetoencephalography. Studies using transcranial magnetic stimulation (TMS) in DS have been uncommon until recently. This is surprising considering the relationship between the functionality of the motor system and DS, and the wide use of TMS in motor-related disturbances such as Parkinson's Disease, Tourette's Syndrome, and dystonia. Consequently, TMS could shed further light on motor aspects of DS. The present work aims to investigate the use of TMS for understanding DS neural mechanisms by reviewing TMS papers in the DS field. Until now, TMS has contributed to the understanding of the excitatory/inhibitory ratio of DS motor functioning, also helping to better understand and critically review evidence about stuttering mechanisms obtained from different techniques, which allowed the investigation of cortico-basal-thalamo-cortical and white matter/connection dysfunctions. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Treatment-Resistant Depression

MedlinePlus

... provide significant relief of severe depression. Repetitive transcranial magnetic stimulation (rTMS). Generally only used when ECT isn't effective, rTMS uses magnetic fields to stimulate nerve cells in the brain ...

Effect of Transcranial Magnetic Stimulation on Neuronal Networks

NASA Astrophysics Data System (ADS)

Unsal, Ahmet; Hadimani, Ravi; Jiles, David

2013-03-01

The human brain contains around 100 billion nerve cells controlling our day to day activities. Consequently, brain disorders often result in impairments such as paralysis, loss of coordination and seizure. It has been said that 1 in 5 Americans suffer some diagnosable mental disorder. There is an urgent need to understand the disorders, prevent them and if possible, develop permanent cure for them. As a result, a significant amount of research activities is being directed towards brain research. Transcranial Magnetic Stimulation (TMS) is a promising tool for diagnosing and treating brain disorders. It is a non-invasive treatment method that produces a current flow in the brain which excites the neurons. Even though TMS has been verified to have advantageous effects on various brain related disorders, there have not been enough studies on the impact of TMS on cells. In this study, we are investigating the electrophysiological effects of TMS on one dimensional neuronal culture grown in a circular pathway. Electrical currents are produced on the neuronal networks depending on the directionality of the applied field. This aids in understanding how neuronal networks react under TMS treatment.

Establishing an effective TMS protocol for craving in substance addiction: Is it possible?

PubMed

Enokibara, Mailu; Trevizol, Alisson; Shiozawa, Pedro; Cordeiro, Quirino

2016-01-01

Repetitive transcranial magnetic stimulation (TMS) is a non-invasive tool with known therapeutic efficacy in various neuropsychiatric disorders, such as depression, schizophrenia, mania, and anxiety disorders. We hereby, briefly present a brief review and meta-analysis on the use of TMS for craving in substance addiction. We present our brief review and meta-analysis following the recommendations of the Cochrane group. A total of eight randomized controlled trials fulfilled eligibility criteria and were selected. A total of 199 patients were studied. We found active stimulation to be superior than sham protocols only for trials focused on right DLPFC (with Hedge's g = 1.48; ES (95%CI: 0.126-2.834), p = 0.032. Main meta-analysis limitations include small number of studies, high heterogeneity among studies, and high publication bias. However challenging, our exploratory analysis underscored the amelioration of craving in substance addiction for trials using high frequency TMS protocols over the right DLPFC. We hereby, propose the use of this particular TMS protocol as a promising tool in clinical research. © American Academy of Addiction Psychiatry.

Protecting and Leaving Functions of Trimethylsilyl Groups in Trimethylsilylated Silicates for the Synthesis of Alkoxysiloxane Oligomers.

PubMed

Yoshikawa, Masashi; Tamura, Yasuhiro; Wakabayashi, Ryutaro; Tamai, Misa; Shimojima, Atsushi; Kuroda, Kazuyuki

2017-11-06

The concept of protecting groups and leaving groups in organic synthesis was applied to the synthesis of siloxane-based molecules. Alkoxy-functionalized siloxane oligomers composed of SiO 4 , RSiO 3 , or R 2 SiO 2 units were chosen as targets (R: functional groups, such as Me and Ph). Herein we describe a novel synthesis of alkoxysiloxane oligomers based on the substitution reaction of trimethylsilyl (TMS) groups with alkoxysilyl groups. Oligosiloxanes possessing TMS groups were reacted with alkoxychlorosilane in the presence of BiCl 3 as a catalyst. TMS groups were substituted with alkoxysilyl groups, leading to the synthesis of alkoxysiloxane oligomers. Siloxane oligomers composed of RSiO 3 and R 2 SiO 2 units were synthesized more efficiently than those composed of SiO 4 units, suggesting that the steric hindrance around the TMS groups of the oligosiloxanes makes a difference in the degree of substitution. This reaction uses TMS groups as both protecting and leaving groups for SiOH/SiO - groups. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A high-fidelity, six-degree-of-freedom batch simulation environment for tactical guidance research and evaluation

NASA Technical Reports Server (NTRS)

Goodrich, Kenneth H.

1993-01-01

A batch air combat simulation environment, the tactical maneuvering simulator (TMS), is presented. The TMS is a tool for developing and evaluating tactical maneuvering logics, but it can also be used to evaluate the tactical implications of perturbations to aircraft performance or supporting systems. The TMS can simulate air combat between any number of engagement participants, with practical limits imposed by computer memory and processing power. Aircraft are modeled using equations of motion, control laws, aerodynamics, and propulsive characteristics equivalent to those used in high-fidelity piloted simulations. Data bases representative of a modern high-performance aircraft with and without thrust-vectoring capability are included. To simplify the task of developing and implementing maneuvering logics in the TMS, an outer-loop control system, the tactical autopilot (TA), is implemented in the aircraft simulation model. The TA converts guidance commands by computerized maneuvering logics from desired angle of attack and wind-axis bank-angle inputs to the inner loop control augmentation system of the aircraft. The capabilities and operation of the TMS and the TA are described.

Improved transcranial magnetic stimulation coil design with realistic head modeling

NASA Astrophysics Data System (ADS)

Crowther, Lawrence; Hadimani, Ravi; Jiles, David

2013-03-01

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.

An investigation into the induced electric fields from transcranial magnetic stimulation

NASA Astrophysics Data System (ADS)

Hadimani, Ravi; Lee, Erik; Duffy, Walter; Waris, Mohammed; Siddiqui, Waquar; Islam, Faisal; Rajamani, Mahesh; Nathan, Ryan; Jiles, David; David C Jiles Team; Walter Duffy Collaboration

Transcranial magnetic stimulation (TMS) is a promising tool for noninvasive brain stimulation that has been approved by the FDA for the treatment of major depressive disorder. To stimulate the brain, TMS uses large, transient pulses of magnetic field to induce an electric field in the head. This transient magnetic field is large enough to cause the depolarization of cortical neurons and initiate a synaptic signal transmission. For this study, 50 unique head models were created from MRI images. Previous simulation studies have primarily used a single head model, and thus give a limited image of the induced electric field from TMS. This study uses finite element analysis simulations on 50 unique, heterogeneous head models to better investigate the relationship between TMS and the electric field induced in brain tissues. Results showed a significant variation in the strength of the induced electric field in the brain, which can be reasonably predicted by the distance from the TMS coil to the stimulated brain. Further, it was seen that some models had high electric field intensities in over five times as much brain volume as other models.

Production and evaluation of Ighu from selected cassava varieties using a motorized shredder—a response surface analysis

PubMed Central

Iwe, Madu O; Agiriga, Ann N

2013-01-01

Cassava varieties, TME419, TMS30572, and TMS98/0505, were planted and harvested at 3-month intervals of 10, 13, and 16 months, respectively. A central composite response surface design was used to study the effects of the variables cassava variety, harvesting time, and shredding aperture on selected physicochemical properties of Ighu samples. Regression models showed that the experimental variables had significant (P ≤ 0.05) effects on the hydrogen cyanide, moisture content, thickness, and width of dry Ighu. Minimum values obtainable for the physicochemical properties were 8.1195 mg/kg (10-month, 3-mm shredding aperture from TMS98/0505), 7.58% (13-month, 3-mm shredding aperture from TME419), 0.19 mm (13-month, 3-mm shredding aperture and from TMS30572), and 0.99 mm (16-month, 3-mm shredding aperture from TME419) for hydrogen cyanide, moisture content, thickness, and width, respectively. In addition, Ighu produced from 3-mm shredding aperture (TMS30572) at 10-month harvest was the most preferred of all the samples. PMID:24804057

Triple Halo Coil: Development and Comparison with Other TMS Coils

NASA Astrophysics Data System (ADS)

Rastogi, Priyam; Hadimani, Ravi; Jiles, David

Transcranial Magnetic Stimulation (TMS) is a non-invasive stimulation technique that can be used for the treatment of various neurological disorders such as Parkinson's Disease, PTSD, TBI and anxiety by regulating synaptic activity. TMS is FDA approved for the treatment of major depressive disorder. There is a critical need to develop deep TMS coils that can stimulate deeper regions of the brain without excessively stimulating the cortex in order to provide an alternative to surgical methods. We have developed a novel multi-coil configuration called ``Triple Halo Coil'' (THC) that can stimulate deep brain regions. Investigation of induced electric and magnetic field in these regions have been achieved by computer modelling. Comparison of the results due to THC configuration have been conducted with other TMS coils such as ``Halo Coil'', circular coil and ``Figure of Eight'' coil. There was an improvement of more than 15 times in the strength of magnetic field, induced by THC configuration at 10 cm below the vertex of the head when compared with the ``Figure of Eight'' coil alone. Carver Charitable Trust.