1. Vorbereitung <ol class="lalpha"><li> Um zu beginnen, erhalten eine Grundlinie anatomischen Scan Ihres Motivs. Dies sollte einige Tage vor dem eigentlichen Experiment. </li><li> Anschließend laden Sie die Scan in Ihr rahmenlose stereotaktische Software-Paket. </li><li> Schließlich finden und die Ausrichtung Ihrer Stimulation koordiniert. In diesem Fall werden wir gezielt die linke unteren Parietallappen. </li></ol> 2. Die Initial Scan <ol class="lalpha"><li> Am Tag des Experiments wird das Motiv noch einmal in das MRT-Gerät zu starten. </li><li> Beginnen Sie mit einer anatomischen scannen. </li><li> Als nächstes führen drei funktionelle Experimente ausführt. Für dieses Experiment ist die Aufgabe ganz einfach: Ein Fixationspunkt wird in das Thema der zentralen Sichtfeld vorgestellt, und er / sie ist, einfach auf sie passiv zu starren. </li></ol> 3. TMS Vorbereitung <ol class="lalpha"><li> Da die Effekte der rTMS vergänglich sind, ist der Zeitfaktor bei der Kombination von TMS und fMRT. Es ist unerlässlich, erhalten Sie das Thema wieder in den Scanner so schnell wie möglich nach der Stimulation Aufhören. Aus diesem Grund sollten Sie auf ein tragbares Gerät TMS in einem Raum neben oder so nah wie möglich an die Scan-bay wie möglich stationiert verwenden. In diesem Fall sind wir mit einem tragbaren Set-up in einer Beobachtung Suite neben dem Scanner. </li><li> Legen Sie Ihr Motiv ist vor gezielten Baseline-MRT in den stereotaktischen Software-Paket. </li><li> Schließlich verbinden und kalibrieren Sie Ihren anregende Spule mit der Stereotaxie Geräte - in diesem Fall werden wir eine Reihe von Infrarotsensoren auszurichten Spule Zentralität registrieren. </li></ol> 4. Bestimmen TMS-Parameter <ol class="lalpha"><li> Wenn das Motiv kommt, sitzen ihm / ihr bequem in einen Stuhl. </li><li> Als nächstes kalibrieren Sie unterliegen den Kopf mit dem sterotaxy Ausrüstung. In diesem Fall verwenden wir Infrarot-Sensoren, um mehrere Positionierung Anker registrieren: beide Ohren, der Nase, und das Nasion. </li><li> Bestimmen Sie Ihr Motiv ist Ruhe Motor Schwelle. </li><li> Wenn wir auf das Thema des Kortex zu erregen wollen, werden wir die TMS-Maschine auf 20 Hz eingestellt mit einer Stimulation von 110% Motor Schwelle. Wenn wir auf das Thema der Hirnrinde zu hemmen wollen, werden wir die TMS-Maschine auf 1 Hz eingestellt bei 110% Motor Schwelle. Obwohl Sie werden beide Parameter im Verlauf einer umfassenden Studie zu erforschen, werden wir erst bei einer 20 Hz rTMS erregenden Kette aussehen in diesem Artikel. </li><li> Schließlich die Einrichtung eines Stimulationsmusters von 2 Sekunden Züge mit 28 Sekunden Ruhezeiten. </li></ol> 5. TMS Stimulation <ol class="lalpha"><li> Vor Stimulation, bereiten das Thema, um direkt in den Scanner folgenden TMS. Dies schließt das Entfernen von Metall und gewährleistet das Thema hat die Toilette benutzt. </li><li> Halten Sie die Spule tangential an der Kopfhaut, nutzen Sie Ihre Stereotaxie Geräte zu lokalisieren und Ziel des Subjekts Stimulation Website. </li><li> Schalten Sie die Maschine Spule Kühlsystem. </li><li> Begin Stimulation! Aus diesem Protokoll führen wir 45 gesamt Stimulation Züge. In 2 Sekunden ein Zug mit 28 Sekunden bricht, haben wir insgesamt stim Zeit von 23 Minuten. </li></ol> 6. Zurück zu den Scanner <ol class="lalpha"><li> Nach Stimulation abgeschlossen ist, ist es wichtig, das Thema wieder in den Scanner so schnell wie möglich. Um diesen Übergang so nahtlos wie möglich, damit Ihr Scanner wird vorbereitet und bereit zu gehen. Unser Rat ist, den Körper Plattform zu erhöhen, und verringern Sie die Anzahl und Dauer der Localizer Scans auf ein Minimum. </li></ol> 7. Endgültiges Scannen <ol class="lalpha"><li> Da die Effekte der rTMS vorübergehend sind, sollte die endgültige Scan-Sitzung mit den funktionellen läuft beginnen. Wieder, führen wir drei, 6-Minuten-Läufe passive Fixierung. </li><li> Nach der Versuchsreihen abgeschlossen sind, mit einer anatomischen Scan zu beenden. </li></ol> 8. Repräsentative Ergebnisse <img src="/files/ftp_upload/2271/2271fig1.jpg" alt="Abbildung 1" /> Abbildung 1. Die Daten deuten darauf hin, dass 20 Hz rTMS Stimulation der linken unteren Parietallappen, obwohl Förderung lokaler Erregbarkeit, wirkt, um funktionelle Konnektivität innerhalb der Standard-Netzwerk zu verringern.

<ol>
	<li>Raichle, M. E., MacLeod, A. M., Snyder, A. Z., Powers, W. J., Gusnard, D. A., Shulman, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+default+mode+of+brain+function.">A default mode of brain function.</a> Proc. Nat. Acad. Sciences. 98 (2), 676-682 (2001).</li><li>Buckner, R. L., Andrews-Hanna, J. R., Schacter, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+brain's+default+network:+anatomy,+function+and+relevance+to+disease.">The brain's default network: anatomy, function and relevance to disease.</a> Ann. N.Y. Acad. Sci. 1124, 1-38 (2008).</li><li>Raichle, M. E., Snyder, A. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+default+mode+of+brain+function:+a+brief+history+of+an+evolving+idea.">A default mode of brain function: a brief history of an evolving idea.</a> Neuroimage. 37 (4), 1083-1090 (2007).</li><li>Whitfield-Gabrieli, S., Thermenos, H. W., Milanovic, S., Tsuang, M. T., Faraone, S. V., McCarley, R. W., Shenton, M. E., Green, A. I., Nieto-Castanon, A., LaViolette, P., Wojcik, J., Gabrieli, J. D., Sidman, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hyperactivity+and+hyperconnectivity+of+the+default+network+in+schizophrenia+and+in+first-degreerelatives+of+persons+with+schizophrenia.">Hyperactivity and hyperconnectivity of the default network in schizophrenia and in first-degreerelatives of persons with schizophrenia.</a> Proc. Nat. Acad. Sciences. 106 (4), 1279-1284 (2009).</li><li>Pomarol-Clotet, E., Salvardor, R., Sarro, S., Gomar, J., Vila, F., Martinez, A., Guerrrero, A., Ortiz-Gil, J., Sans-Sansa, B., Capdevila, A., Cebamanos, J. M., McKenna, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Failure+to+deactivate+the+prefrontal+cortex+in+schizophrenia:+dysfunction+of+the+default+mode+network?.">Failure to deactivate the prefrontal cortex in schizophrenia: dysfunction of the default mode network?.</a> Psychol Med. 38 (8), 1185-1193 (2008).</li><li>Garrity, A. G., Pearlson, G. D., McKiernan, K., Lloyd, D., Kiehl, K. A., Calhoun, V. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aberrant+"default+mode"+functional+connectivity+in+schizophrenia.">Aberrant "default mode" functional connectivity in schizophrenia.</a> American Journal of Psychiatry. 164, 450-457 (2007).</li><li>Kennedy, D. P., Redcay, E., Courchesne, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Failing+to+deactivate:+Resting+functional+abnormalities+in+autism.">Failing to deactivate: Resting functional abnormalities in autism.</a> Proc. Nat. Acad. Sciences. 103 (21), 8275-8280 (2007).</li><li>c Buckner, R. L., Snyder, A. Z., Shannon, B. J., LaRossa, G., Sachs, R., Fotenos, A. F., Sheline, Y. I., Klunk, W. E., Mathis, C. A., Morris, J. C., Mintun, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular,+structural,+and+functional+characterizations+of+Alzheimer's+disease:+evidence+for+a+relationship+between+default+activity,+amyloid,+and+memory.">Molecular, structural, and functional characterizations of Alzheimer's disease: evidence for a relationship between default activity, amyloid, and memory.</a> Journal of Neuroscience. 34, 7709-7717 (2005).</li><li>Pascual-Leone, A., Davey, M., Wassermann, E. M., Rothwell, J., Puri, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Handbook of Transcranial Magnetic Stimulation. , (2002).</li></ol>

<p class="jove_content"&gt; Bei der Durchführung einer Offline-TMS / MRI-Experiment, wohl die wichtigste Überlegung betrifft den schnellen und mühelosen Übergang von der Website der Stimulation auf die MRI Bucht. Als solcher würde er sicher lohnend, einige der genannten Ideen vorgeschlagen, um in dieser Übergangsphase zu unterstützen. Erstens: Verwenden Sie ein tragbares TMS Maschine an einem Ort so nah an der MRI Bucht wie möglich einzustellen. Two: Abgrenzung von Stand-by oder entsprechender Mechanismus in den MRT-Geräte programmiert...

<ul><li> MRT für fMRI (im Bild in Video ist ein Philips) ausgestattet </li><li> TMS Gerät in der Lage Repetitive Stimulation (im Bild in Video ist ein Magstim) </li><li> Rahmenlose Stereotaxie Ausstattung (im Bild in Video Brainsight) </li><li> Gehörschutzstöpsel </li><li> Lehrstuhl für Subject während der Stimulation </li><li> Rückprojektions-Screen-oder MRT-kompatibel Goggles </li><li> Blank Stimuli Bildschirm </li></ul>

combining transcranial magnetic stimulation and fmri to examine the default mode network

Der Standard-Modus-Netzwerk ist eine Gruppe von Hirnregionen, die aktiv sind, wenn eine Person nicht auf die Außenwelt konzentriert und das Gehirn ist bei &quot;wachen Ruhe.&quot; 1,2,3 Es wird vermutet, der Standard-Modus-Netzwerk entspricht selbstreferentiellen oder &quot;interne Umsetzung&quot;. 2,3 Es wurde die Hypothese aufgestellt, dass bei Menschen, die Tätigkeit innerhalb der Standard-Modus-Netzwerk mit bestimmten Krankheiten (zB korreliert ist, hat hyper-Aktivierung von Schizophrenie 4,5,6 und Autismus 7 während hypo-Aktivierung des Netzwerks in Verbindung gebracht wurde worden, um Alzheimer und andere neurodegenerative Erkrankungen 8) verbunden. Als solche nicht-invasive Modulation dieses Netzwerk kann eine potentielle therapeutische Intervention für eine Reihe von neurologischen und psychiatrischen Erkrankungen im Zusammenhang mit abnormalen Netzwerk-Aktivierung. Ein mögliches Instrument, um diese Modulation Effekt ist Transkranielle Magnetstimulation: eine nicht-invasive neurostimulatory und neuromodulatorischen Technik, die vorübergehend oder dauerhaft modulieren kann kortikalen Erregbarkeit (entweder steigend oder fallend ist) über die Anwendung der lokalisierten Magnetfeldimpulsen 9. Um den Standard-Modus Netzwerks Neigung zur Toleranz und der Modulation zu erforschen, werden wir die Kombination von TMS (links inferior Scheitellappen) mit der funktionellen Magnetresonanztomographie (fMRI). Durch diesen Artikel werden wir untersuchen, das Protokoll und Überlegungen notwendig, um erfolgreich zu kombinieren diese beiden neurowissenschaftlichen Werkzeuge.

Watch this Scientific Journal Video about Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network at JoVE.com

Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network

In diesem Artikel untersuchen wir die Methodik und Erwägungen, die für die Kombination von TMS und fMRT, um die Auswirkungen der Stimulation des Gehirns über die Standard-Netzwerk zu untersuchen.

Die Kombination TMS und fMRT dem Standard-Modus Netzwerk Untersuchen

The default mode network is a group of brain regions that are active when an individual is not focused on the outside world and the brain is at "wakeful ...

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Research

JoVE Journal

Neuroscience

12.8K Aufrufe.  Beth Israel Deaconess Medical Center. In diesem Artikel untersuchen wir die Methodik und Erwägungen, die für die Kombination von TMS und fMRT, um die Auswirkungen der Stimulation des Gehirns über die Standard-Netzwerk zu untersuchen.

Serie: Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network

A Novel Approach for Documenting Phosphenes Induced by Transcranial Magnetic Stimulation

Stimulation of the human visual cortex produces a transient perception of light, known as a phosphene. Phosphenes are induced by invasive electrical stimulation of the occipital cortex, but also by non-invasive Transcranial Magnetic Stimulation (TMS)1 of the same cortical regions. The intensity at which a phosphene is induced (phosphene threshold) is a well established measure of visual cortical excitability and is used to study cortico-cortical interactions, functional organization 2, susceptibility to pathology 3,4 and visual processing 5-7. Phosphenes are typically defined by three characteristics: they are observed in the visual hemifield contralateral to stimulation; they are induced when the subject s eyes are open or closed, and their spatial location changes with the direction of gaze 2. Various methods have been used to document phosphenes, but a standardized methodology is lacking. We demonstrate a reliable procedure to obtain phosphene threshold values and introduce a novel system for the documentation and analysis of phosphenes. We developed the Laser Tracking and Painting system (LTaP), a low cost, easily built and operated system that records the location and size of perceived phosphenes in real-time. The LTaP system provides a stable and customizable environment for quantification and analysis of phosphenes.

Phosphenes are transient percepts of light that can be induced by applying Transcranial Magnetic Stimulation (TMS) to visually sensitive regions of cortex. We demonstrate a standard protocol for determining the phosphene threshold value and introduce a novel method for quantifying and analyzing perceived phosphenes.

Ein neuer Ansatz zur Dokumentation Phosphenes durch TMS induzierte

Stimulation of the human visual cortex produces a transient perception of light, known as a phosphene. Phosphenes are induced by invasive electrical ...

Forschung

Neurowissenschaften

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation

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&#39;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.

This paper describes a method for collecting and analyzing electroencephalography (EEG) data during concurrent transcranial magnetic stimulation (TMS) guided by activations revealed with functional magnetic resonance imaging (fMRI). A method for TMS artifact removal and extraction of event related potentials is described as well as considerations in paradigm design and experimental setup.

Extrahieren von visuell evozierten Potentiale von EEG-Daten aufzeichnen Während fMRI-geführte Transkranielle Magnetstimulation

Transcranial Magnetic Stimulation (TMS) is an effective method for establishing a causal link between a cortical area and cognitive/neurophysiological ...

The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of neurological and psychiatric disorders such as stroke and depression. Yet, the mechanisms underlying its ability to modulate brain excitability to improve clinical symptoms remains poorly understood 33. To help improve this understanding, proton magnetic resonance spectroscopy (1H-MRS) can be used as it allows the in vivo quantification of brain metabolites such as &#947;-aminobutyric acid (GABA) and glutamate in a region-specific manner 41. In fact, a recent study demonstrated that 1H-MRS is indeed a powerful means to better understand the effects of tDCS on neurotransmitter concentration 34. This article aims to describe the complete protocol for combining tDCS (NeuroConn MR compatible stimulator) with 1H-MRS at 3 T using a MEGA-PRESS sequence. We will describe the impact of a protocol that has shown great promise for the treatment of motor dysfunctions after stroke, which consists of bilateral stimulation of primary motor cortices 27,30,31. Methodological factors to consider and possible modifications to the protocol are also discussed.

This article aims to describe a basic protocol for combining transcranial direct current stimulation (tDCS) with proton magnetic resonance spectroscopy (1H-MRS) measurements to investigate the effects of bilateral stimulation on primary motor cortex metabolism.

Die Verwendung von magnetischen Resonanzspektroskopie als Werkzeug für die Messung der Bi-hemisphärische transkranielle elektrische Stimulation Auswirkungen auf primären motorischen Kortex Metabolism

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of ...

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific frequency and in turn modulate ongoing cortical oscillatory activity. This neurotool allows the establishment of a causal link between endogenous oscillatory activity and behavior. Most of the tACS studies have shown online effects of tACS. However, little is known about the underlying action mechanisms of this technique because of the AC-induced artifacts on Electroencephalography (EEG) signals. Here we show a unique approach to investigate online physiological frequency-specific effects of tACS of the primary motor cortex (M1) by using single pulse Transcranial Magnetic Stimulation (TMS) to probe cortical excitability changes. In our setup, the TMS coil is placed over the tACS electrode while Motor Evoked Potentials (MEPs) are collected to test the effects of the ongoing M1-tACS. So far, this approach has mainly been used to study the visual and motor systems. However, the current tACS-TMS setup can pave the way for future investigations of cognitive functions. Therefore, we provide a step-by-step manual and video guidelines for the procedure.

Transcranial Alternating Current Stimulation (tACS) allows the modulation of cortical excitability in a frequency-specific fashion. Here we show a unique approach which combines online tACS with single pulse Transcranial Magnetic Stimulation (TMS) in order to "probe" cortical excitability by means of Motor Evoked Potentials.

Effekte der transkraniellen Wechselstrom Stimulation auf Primärbewegungsrinde durch Online-kombinierter Ansatz mit Transcranial magnetische Anregung

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific ...

Combined Transcranial Magnetic Stimulation and Electroencephalography of the Dorsolateral Prefrontal Cortex

Transcranial magnetic stimulation (TMS) is a non-invasive method that produces neural excitation in the cortex by means of brief, time-varying magnetic field pulses. The initiation of cortical activation or its modulation depends on the background activation of the neurons of the cortical region activated, the characteristics of the coil, its position and its orientation with respect to the head. TMS combined with simultaneous electrocephalography (EEG) and neuronavigation (nTMS-EEG) allows for the assessment of cortico-cortical excitability and connectivity in almost all cortical areas in a reproducible manner. This advance makes nTMS-EEG a powerful tool that can accurately assess brain dynamics and neurophysiology in test-retest paradigms that are required for clinical trials. Limitations of this method include artifacts that cover the initial brain reactivity to stimulation. Thus, the process of removing artifacts may also extract valuable information. Moreover, the optimal parameters for dorsolateral prefrontal (DLPFC) stimulation are not fully known and current protocols utilize variations from the motor cortex (M1) stimulation paradigms. However, evolving nTMS-EEG designs hope to address these issues. The protocol presented here introduces some standard practices for assessing neurophysiological functioning from stimulation to the DLPFC that can be applied in patients with treatment resistant psychiatric disorders that receive treatment such as transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), magnetic seizure therapy (MST) or electroconvulsive therapy (ECT).

The protocol presented here is for TMS-EEG studies utilizing intracortical excitability test-retest design paradigms. The intent of the protocol is to produce reliable and reproducible cortical excitability measures for assessing neurophysiological functioning related to therapeutic interventions in the treatment of neuropsychiatric diseases such as major depression.

Kombinierte Transcranial magnetische Anregung und Elektroenzephalographie des dorsolateralen präfrontalen Kortex

Transcranial magnetic stimulation (TMS) is a non-invasive method that produces neural excitation in the cortex by means of brief, time-varying magnetic ...

Bilateral Assessment of the Corticospinal Pathways of the Ankle Muscles Using Navigated Transcranial Magnetic Stimulation

Distal leg muscles receive neural input from motor cortical areas via the corticospinal tract, which is one of the main motor descending pathway in humans and can be assessed using transcranial magnetic stimulation (TMS). Given the role of distal leg muscles in upright postural and dynamic tasks, such as walking, a growing research interest in the assessment and modulation of the corticospinal tracts relative to the function of these muscles has emerged in the last decade. However, methodological parameters used in previous work have varied across studies making the interpretation of results from cross-sectional and longitudinal studies less robust. Therefore, use of a standardized TMS protocol specific to the assessment of leg muscles&#39; corticomotor response (CMR) will allow for direct comparison of results across studies and cohorts. The objective of this paper is to present a protocol that provides the flexibility to simultaneously assess the bilateral CMR of two main ankle antagonistic muscles, the tibialis anterior and soleus, using single pulse TMS with a neuronavigation system. The present protocol is applicable while the examined muscle is either fully relaxed or isometrically contracted at a defined percentage of maximum isometric voluntary contraction. Using each subject&#39;s structural MRI with the neuronavigation system ensures accurate and precise positioning of the coil over the leg cortical representations during assessment. Given the inconsistency in CMR derived measures, this protocol also describes a standardized calculation of these measures using automated algorithms. Though this protocol is not conducted during upright postural or dynamic tasks, it&#160;can be used to assess bilaterally any pair of leg muscles, either antagonistic or synergistic, in both neurologically intact and impaired subjects.

The present protocol describes the simultaneous, bilateral assessment of the corticomotor response of the tibialis anterior and soleus during rest and tonic voluntary activation using a single pulse transcranial magnetic stimulation and neuronavigation system.

Bilateralen Bewertung der kortikospinalen Bahnen der Knöchel Muskeln mit navigierte transkranielle Magnetstimulation

Distal leg muscles receive neural input from motor cortical areas via the corticospinal tract, which is one of the main motor descending pathway in humans ...

Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation

Understanding interactions between brain areas is important for the study of goal-directed behavior. Functional neuroimaging of brain connectivity has provided important insights into fundamental processes of the brain like cognition, learning, and motor control. However, this approach cannot provide causal evidence for the involvement of brain areas of interest. Transcranial magnetic stimulation (TMS) is a powerful, noninvasive tool for studying the human brain that can overcome this limitation by transiently modifying brain activity. Here, we highlight recent advances using a paired-pulse, dual-site TMS method with two coils that causally probes cortico-cortical interactions in the human motor system during different task contexts. Additionally, we describe a dual-site TMS protocol based on cortical paired associative stimulation (cPAS) that transiently enhances synaptic efficiency in two interconnected brain areas by applying repeated pairs of cortical stimuli with two coils. These methods can provide a better understanding of the mechanisms underlying cognitive-motor function as well as a new perspective on manipulating specific neural pathways in a targeted fashion to modulate brain circuits and improve behavior. This approach may prove to be an effective tool to develop more sophisticated models of brain-behavior relations and improve diagnosis and treatment of many neurological and psychiatric disorders.

This article describes new approaches to measure and strengthen functionally specific neural pathways with transcranial magnetic stimulation. These advanced noninvasive brain stimulation methodologies can provide new opportunities for the understanding of brain-behavior relations and development of new therapies to treat brain disorders.

Messung und Manipulation funktionell spezifischer neuronaler Bahnen im menschlichen Motorsystem mit transkranieller Magnetstimulation

Understanding interactions between brain areas is important for the study of goal-directed behavior. Functional neuroimaging of brain connectivity has ...

Employing Transcranial Magnetic Stimulation in a Resource Limited Environment to Establish Brain-Behavior Relationships

Neuroimaging is typically perceived as a resource demanding discipline. While this is the case in certain circumstances, institutions with limited resources have historically contributed significantly to the field of neuroscience, including neuroimaging. In the study of self-deception, we have successfully employed single-pulse TMS to determine the brain correlates of abilities including overclaiming and self-enhancement. Even without the use of neuro-navigation, methods provided here lead to successful outcomes. For example, it was discovered that decreases in self-deceptive responding lead to a decrease in affect. These methods provide data that are reliable and valid, and such methods provide research opportunities otherwise unavailable.&#160;Through the use of these methods, the overall knowledge base in the field of neuroscience is expanded, providing research opportunities to students such as those at our institution&#160;(Montclair State University is a Hispanic-Serving Institute) who are often denied such research experiences.

Transcranial Magnetic Stimulation (TMS) and low-frequency TMS (lfTMS) have&#160;been demonstrated to be major contributors to brain literature. Here we highlight the methods for investigating the cortical correlates of self-deception using TMS.

Einsatz transkranieller Magnetstimulation in einer ressourcenbegrenzten Umgebung, um Gehirn-Verhaltens-Beziehungen herzustellen

Neuroimaging is typically perceived as a resource demanding discipline. While this is the case in certain circumstances, institutions with limited ...

Conventional and Threshold-Tracking Transcranial Magnetic Stimulation Tests for Single-handed Operation

Most single-pulse transcranial magnetic stimulation (TMS) parameters (e.g., motor threshold, stimulus-response function, cortical silent period) are used to examine corticospinal excitability. Paired-pulse TMS paradigms (e.g., short- and long-interval intracortical inhibition (SICI/LICI), short-interval intracortical facilitation (SICF), and short- and long-latency afferent inhibition (SAI/LAI)) provide information about intracortical inhibitory and facilitatory networks. This has long been done by the conventional TMS method of measuring changes in the size of the motor-evoked potentials (MEPs) in response to stimuli of constant intensity. An alternative threshold-tracking approach has recently been introduced whereby the stimulus intensity for a target amplitude is tracked. The diagnostic utility of threshold-tracking SICI in amyotrophic lateral sclerosis (ALS) has been shown in previous studies. However, threshold-tracking TMS has only been used in a few centers, in part due to the lack of readily available software but also perhaps due to uncertainty over its relationship to conventional single- and paired-pulse TMS measurements.
A menu-driven suite of semi-automatic programs has been developed to facilitate the broader use of threshold-tracking TMS techniques and to enable direct comparisons with conventional amplitude measurements. These have been designed to control three types of magnetic stimulators and allow recording by a single operator of the common single- and paired-pulse TMS protocols.
This paper shows how to record a number of single- and paired-pulse TMS protocols on healthy subjects and analyze the recordings. These TMS protocols are fast and easy to perform and can provide useful biomarkers in different neurological disorders, particularly neurodegenerative diseases such as ALS.

We present a suite of standardized single- and paired-pulse transcranial magnetic stimulation (TMS) recording protocols, with options for conventional amplitude measurements and threshold-tracking. This program can control three different types of magnetic stimulators and is designed to enable all tests to be performed conveniently by a single operator.

Konventionelle und Threshold-Tracking Transkranielle Magnetstimulationstests für die Einhandbedienung

Most single-pulse transcranial magnetic stimulation (TMS) parameters (e.g., motor threshold, stimulus-response function, cortical silent period) are used ...

Kombinierte periphere Nervenstimulation und steuerbarer Pulsparameter TMS

Combined Peripheral Nerve Stimulation and Controllable Pulse Parameter Transcranial Magnetic Stimulation to Probe Sensorimotor Control and Learning

Skilled motor ability depends on efficiently integrating sensory afference into the appropriate motor commands. Afferent inhibition provides a valuable tool to probe the procedural and declarative influence over sensorimotor integration during skilled motor actions. This manuscript describes the methodology and contributions of short-latency afferent inhibition (SAI) for understanding sensorimotor integration. SAI quantifies the effect of a convergent afferent volley on the corticospinal motor output evoked by transcranial magnetic stimulation (TMS). The afferent volley is triggered by the electrical stimulation of a peripheral nerve. The TMS stimulus is delivered to a location over the primary motor cortex that elicits a reliable motor-evoked response in a muscle served by that afferent nerve. The extent of inhibition in the motor-evoked response reflects the magnitude of the afferent volley converging on the motor cortex and involves central GABAergic and cholinergic contributions. The cholinergic involvement in SAI makes SAI a possible marker of declarative-procedural interactions in sensorimotor performance and learning. More recently, studies have begun manipulating the TMS current direction in SAI to tease apart the functional significance of distinct sensorimotor circuits in the primary motor cortex for skilled motor actions. The ability to control additional pulse parameters (e.g., the pulse width) with state-of-the-art controllable pulse parameter TMS (cTMS) has enhanced the selectivity of the sensorimotor circuits probed by the TMS stimulus and provided an opportunity to create more refined models of sensorimotor control and learning. Therefore, the current manuscript focuses on SAI assessment using cTMS. However, the principles outlined here also apply to SAI assessed using conventional fixed pulse width TMS stimulators and other forms of afferent inhibition, such as long-latency afferent inhibition (LAI).

Autor im Rampenlicht: Kombinierte periphere Nervenstimulation und kontrollierbare Pulsparameter Transkranielle Magnetstimulation zur Sondierung der sensomotorischen Kontrolle und des Lernens  

Short-latency afferent inhibition (SAI) is a transcranial magnetic stimulation protocol to probe sensorimotor integration. This article describes how SAI can be used to study the convergent sensorimotor loops in the motor cortex during sensorimotor behavior.

Kombinierte periphere Nervenstimulation und transkranielle Magnetstimulation mit kontrollierbaren Pulsparametern zur Untersuchung der sensomotorischen Kontrolle und des Lernens

Skilled motor ability depends on efficiently integrating sensory afference into the appropriate motor commands. Afferent inhibition provides a valuable ...