1. Inducendo un fosfene con stimolazione al lobo occipitale destra <ol class="lalpha"><li> In una stanza scarsamente illuminata, sede del partecipante in una posizione comoda. Hanno il partecipante messo su una cuffia, fornire loro protezione dell&#39;udito, e regolare il cappuccio e tappi per le orecchie per il massimo comfort. Per individuare e segnare il punto iniziale della stimolazione, in primo luogo identificare il inion, e quindi spostare ~ 2 centimetri rostralmente e ~ 2 centimetri lateralmente (figura 1). In alternativa, un sistema senza cornice stereotassica può essere utilizzato per posizionare la bobina TMS sulla regione corticale mirati. </li><li> Utilizzando un normale forma di otto (doppio) bobina TMS (70mm), posto al centro della bobina direttamente sulla posizione determinata nel passaggio precedente. La bobina deve essere ritenuto tangente alla superficie del cuoio capelluto e orientato in una mediale di orientamento laterale con il manico rivolto verso la linea mediana (figura 2). </li><li> Quando il partecipante è pronto, applicare un singolo impulso in uscita di intensità 60%. Chiedete ai partecipanti di descrivere ogni sensazione visiva che possono avere percepito. I partecipanti che sono ingenuo fosfeni possono beneficiare di indossare una benda. Se non fosfene è stato segnalato, riposizionare la bobina e riconsegnare un impulso. Se il partecipante continua a non segnalare un fosfene, continuare a fornire impulsi ogni 7 a 10 secondi (~ 0,1 Hz), aumentando l&#39;intensità del 5% ogni cinque tentativi fino al 100% l&#39;intensità è raggiunto. </li><li> Quando il partecipante riporta un fosfene chiedergli o lei a descrivere in dettaglio ciò che percepivano tra cui colore, forma e posizione. Nota: Fosfeni dovrebbe apparire nel campo visivo controlaterale all&#39;emisfero che viene stimolato. Per esempio, se TMS è applicato sul diritto corteccia visiva, fosfeni dovrebbero essere percepito nel campo visivo sinistro. </li><li> Quando fosfeni sono riportate affidabile, contrassegnare la posizione della bobina sul tappo nuotare. </li></ol> 2. Ottenere un valore fosfene soglia del lobo occipitale destra <ol class="lalpha"><li> Fornire una serie di impulsi nella posizione della bobina stessa e orientamento come sopra. Chiedere al partecipante di confermare la presenza del fosfene indotto. </li><li> Fornire impulsi ogni 7 a 10 secondi (~ 0,1 Hz). Istruire i partecipanti a riferire, dopo ogni impulso, se un fosfene è stato percepito utilizzando i seguenti criteri: con un &quot;sì&quot; un fosfene senza ambiguità, &quot;no&quot; l&#39;assenza di percezione visiva, &quot;forse&quot; se non sono sicuri. Una risposta &quot;forse&quot; non dovrebbe essere considerato come una risposta positiva nel determinare il valore di soglia. </li><li> Regolare l&#39;intensità di stimolazione, offrendo 10 impulsi ad ogni livello di intensità, fino a una soglia fosfene è determinata. La soglia è definita come la più bassa intensità di stimolazione in cui il partecipante rapporti fosfeni inequivocabile per almeno il cinquanta per cento di impulsi consegnato. </li></ol> 3. Utilizzo del sistema LTaP (Figura 3) per determinare la dimensione e la posizione di Fosfeni nei punti di fissaggio vari <ol class="lalpha"><li> Sedile del partecipante in modo che il nasion (zona tra gli occhi) è di circa 30 centimetri dal centro dello schermo di proiezione. </li><li> Per acclimatare il partecipante al sistema LTaP, dare loro il puntatore laser e di istruirli a praticare tracciare figure che assomigliano fosfeni percepito. Se il partecipante ha bisogno di più pratica, si può chiedere al partecipante di dirigere il puntatore laser a posizioni indicate sullo schermo di proiezione. Quando il partecipante conosce il sistema LTaP e può disegnare forme con precisione sullo schermo, fornire una serie di impulsi TMS alla posizione marcata nei passaggi precedenti sufficiente per indurre un fosfene visibile. Chiedere al partecipante di tracciare o di uno schema fosfene percepita sullo schermo di proiezione utilizzando il puntatore laser. </li><li> Nei tre condizioni di prova l&#39;intensità dello stimolo deve essere al 120% del valore di soglia determinato. Per esempio, se il valore di soglia determinato è del 65%, il valore di intensità dello stimolo deve essere impostato al 78%. La posizione della bobina e l&#39;orientamento è lo stesso di cui e descritto nei passi precedenti. </li><li> Nella prima delle tre condizioni di prova, hanno il partecipante diretto lo sguardo verso un punto di fissazione centrale. Dopo aver consegnato un impulso di istruire i partecipanti per tracciare o di uno schema fosfene percepito tramite il puntatore laser. Fornire una serie di impulsi sufficienti per indurre dieci fosfeni. </li><li> Nella condizione secondo test, hanno il partecipante diretto lo sguardo verso un punto di fissazione che si eleva a 45 ° dal punto di fissazione centrale. Ripetere il protocollo come descritto per la prima condizione. </li><li> Nella condizione di terza prova, hanno il partecipante diretto lo sguardo verso un punto di fissazione che è posizionato 45 ° a destra del punto di fissazione centrale. Ripetere il protocollo come descritto per la prima condizione. </li></ol> 4. Una datiANALISI <ol class="lalpha"><li> Dopo il completamento dei dati dello studio ottenuti dal sistema LTaP può essere analizzato. L&#39;uscita del sistema LTAP è costituito da un file. Xml compreso codice colore coordinate XY con data e ora per ogni record di traccia. Analizzare i dati al fine di rilevare lo spostamento in posizione fosfene in riferimento al cambiamento di sguardo. </li></ol> 5. Rappresentante Risultati Quando la bobina TMS è posta sopra l&#39;emisfero destro tutti fosfeni dovrebbero essere osservati nel campo visivo sinistro. Quando i partecipanti sono istruiti a guardare dritto, fosfeni sono generalmente in basso a sinistra del campo visivo. Fosfeni dovrebbero muoversi secondo il cambiamento di sguardo visivo (sia a 45 ° in verticale o in orizzontale dalla fissazione centrale) (figura 4). <img src="/files/ftp_upload/1762/1762fig1.jpg" alt="figura 1" /> Figura 1. Individuazione e marcatura iniziale del sito di stimolazione. Per le aree visive occipitali, il sito di stimolazione iniziale (a) si trova in genere ~ 2 centimetri dorsalmente e ~ 2 cm lateralmente dalla inion (b). <img src="/files/ftp_upload/1762/1762fig2.jpg" alt="figura 2" /> Figura 2. Posizionare la bobina di stimolazione. Il centro della bobina è tenuta tangenziale al cuoio capelluto nel sito di stimolazione. Per ridurre al minimo una diffusione involontaria di stimolazione, orientare la maniglia della bobina di distanza dalla linea mediana. <img src="/files/ftp_upload/1762/1762fig3.jpg" alt="figura 3" /> Figura 3. L&#39;(tracciamento laser e pittura) LTaP sistema. Un partecipante (a) si siede di fronte a uno schermo di proiezione posteriore (b). Dopo stimolazione dalla bobina TMS (c), il partecipante utilizza un puntatore laser (d) per disegnare la fosfeni percepita sullo schermo (d). Un posteriore rivolto webcam (e) della documentazione il laser e si alimenta a un computer (f) in esecuzione il software LTaP. I dati vengono quindi proiettati di nuovo sullo schermo tramite una retro-proiettore di fronte (g). <img src="/files/ftp_upload/1762/1762fig4.jpg" alt="figura 4" /> Figura 4. Post-elaborazione dei dati LTaP. La posizione e le dimensioni dei fosfeni percepita (forme bianco) sono indicate in relazione alla posizione di fissazione, indicato dal mirino.

<ol>
	<li>Kammer, T., Puls, K., Strasburger, H., Hill, N. J., Wichmann, F. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+Magnetic+Stimulation+in+the+Visual+System.+I.+the+Psychophysics+of+Visual+Suppression.">Transcranial Magnetic Stimulation in the Visual System. I. the Psychophysics of Visual Suppression.</a> Experimental Brain Research. 160, 118-128 (2005).</li><li>Afra, J., Mascia, A., G&#233;rard, P., Maertens de Noordhout, A., Schoenen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interictal+cortical+excitability+in+migraine:+a+study+using+transcranial+magnetic+stimulation+of+motor+and+visual+cortices.">Interictal cortical excitability in migraine: a study using transcranial magnetic stimulation of motor and visual cortices.</a> Ann. Neurol. 44, 209-215 (1998).</li><li>Aurora, S. K., Ahmad, B. K., Welch, K. M., Bhardhwaj, P., Ramadan, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcranial+magnetic+stimulation+confirms+hyperexcitability+of+occipital+cortex+in+migraine.">Transcranial magnetic stimulation confirms hyperexcitability of occipital cortex in migraine.</a> Neurology. 50, 1111-1114 (1998).</li><li>Silvanto, J., Pascual-Leone, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> State-Dependency of Transcranial Magnetic Stimulation. Brain Topography. 21, 1-10 (2008).</li><li>Silvanto, J., Muggleton, N., Cowey, A., Walsh, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+adaptation+reveals+state-dependent+effects+of+transcranial+magnetic+stimulation.">Neural adaptation reveals state-dependent effects of transcranial magnetic stimulation.</a> European Journal of Neuroscience. 25, (2007).</li><li>Kammer, T., Beck, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phosphene+thresholds+evoked+by+transcranial+magnetic+stimulation+are+insensitive+to+short-lasting+variations+in+ambient+light.">Phosphene thresholds evoked by transcranial magnetic stimulation are insensitive to short-lasting variations in ambient light.</a> Exp Brain Res. 145, 407-4010 (2002).</li><li>Bjoertomt, O., Cowey, A., Walsh, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+neglect+in+near+and+far+space+investigated+by+repetitive+transcranial+magnetic+stimulation.">Spatial neglect in near and far space investigated by repetitive transcranial magnetic stimulation.</a> Brain. 125, 2012-2022 (2002).</li><li>Gothe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+visual+cortex+excitability+in+blind+subjects+as+demonstrated+by+transcranial+magnetic+stimulation.">Changes in visual cortex excitability in blind subjects as demonstrated by transcranial magnetic stimulation.</a> Brain. 125, 479-490 (2002).</li><li>Hotson, J. R., Anand, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+selectivity+and+timing+of+motion+processing+in+human+temporo-parieto-occipital+and+occipital+cortex:+a+transcranial+magnetic+stimulation+study.">The selectivity and timing of motion processing in human temporo-parieto-occipital and occipital cortex: a transcranial magnetic stimulation study.</a> Neuropsychologia. 37, 169-179 (1999).</li><li>Kammer, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phosphenes+and+transient+scotomas+induced+by+magnetic+stimulation+of+the+occipital+lobe:+their+topographic+relationship.">Phosphenes and transient scotomas induced by magnetic stimulation of the occipital lobe: their topographic relationship.</a> Neuropsychologia. 37, 191-198 (1998).</li><li>Stewart, L., Ellison, A., Walsh, V., Cowey, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+transcranial+magnetic+stimulation+(TMS)+in+studies+of+vision,+attention+and+cognition.">The role of transcranial magnetic stimulation (TMS) in studies of vision, attention and cognition.</a> Acta Psychol (Amst). , 107-275 (2001).</li></ol>

In questo video, abbiamo dimostrato un protocollo standard per l&#39;ottenimento di un valore soglia fosfene e ha introdotto un nuovo metodo per la registrazione fosfene dimensioni e la posizione del campo visivo. Fosfeni sono stati suscitato fornendo singoli impulsi di TMS alla corteccia occipitale destra adiacente al polo occipitale. Valori di soglia fosfene forniscono un&#39;indicazione preziosa di relativa eccitabilità corticale, e sono stati utilizzati sia come misura di outcome e come mezzo di determinare l&#39;i...

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<td>TMS</td>
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<td>Epson PowerLite 7900p</td>
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<td>Da-View fast-fold deluxe screen</td>
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a novel approach for documenting phosphenes induced by transcranial magnetic stimulation

Stimolazione della corteccia visiva umana produce una percezione transitoria di luce, noto come fosfene. Fosfeni sono indotte da invasivi stimolazione elettrica della corteccia occipitale, ma anche da non invasiva di stimolazione magnetica transcranica (TMS)<sup&gt; 1</sup&gt; Delle stesse regioni corticali. L&#39;intensità con cui viene indotto un fosfene (soglia fosfene) è una misura ben consolidata di eccitabilità della corteccia visiva ed è utilizzato per studiare le interazioni cortico-corticali, organizzazione funzionale<sup&gt; 2</sup&gt;, Suscettibilità alla patologia<sup&gt; 3,4</sup&gt; E l&#39;elaborazione visiva<sup&gt; 5-7</sup&gt;. Fosfeni sono generalmente definito da tre caratteristiche: sono osservati nel emicampo visivo controlaterale alla stimolazione, sono indotte quando gli occhi del soggetto s sono aperte o chiuse, e la loro localizzazione spaziale cambia con la direzione dello sguardo<sup&gt; 2</sup&gt;. Vari metodi sono stati usati per documentare fosfeni, ma una metodologia standardizzata che manca. Dimostriamo una procedura affidabile per ottenere valori di soglia fosfene e introdurre un nuovo sistema per la documentazione e l&#39;analisi dei fosfeni. Abbiamo sviluppato il laser tracking e pittura di sistema (LTaP), un basso costo, facilmente costruiti e gestiti sistema che registra la posizione e le dimensioni dei fosfeni percepito in tempo reale. Il sistema LTaP fornisce un ambiente stabile e personalizzabile per la quantificazione e analisi dei fosfeni.

Watch this Scientific Journal Video about A Novel Approach for Documenting Phosphenes Induced by Transcranial Magnetic Stimulation at JoVE.com

A Novel Approach for Documenting Phosphenes Induced by Transcranial Magnetic Stimulation

Fosfeni sono percezioni transitori di luce che può essere indotta mediante l&#39;applicazione di Stimolazione Magnetica Transcranica (TMS) per le regioni della corteccia visiva sensibili. Dimostriamo un protocollo standard per la determinazione del valore di soglia fosfene e introdurre un nuovo metodo per quantificare ed analizzare fosfeni percepito.

Un nuovo approccio per documentare Fosfeni indotta dalla Stimolazione Magnetica Transcranica

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

a-novel-approach-for-documenting-phosphenes-induced-transcranial

Research

JoVE Journal

Neuroscience

12.0K Views.  Boston University School of Medicine. Fosfeni sono percezioni transitori di luce che può essere indotta mediante l'applicazione di Stimolazione Magnetica Transcranica (TMS) per le regioni della corteccia visiva sensibili. Dimostriamo un protocollo standard per la determinazione del valore di soglia fosfene e introdurre un nuovo metodo per quantificare ed analizzare fosfeni percepito.

Video: A Novel Approach for Documenting Phosphenes Induced by Transcranial Magnetic Stimulation

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

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 rest."1,2,3 It is thought the default mode network corresponds to self-referential or "internal mentation".2,3
It has been hypothesized that, in humans, activity within the default mode network is correlated with certain pathologies (for instance, hyper-activation has been linked to schizophrenia 4,5,6 and autism spectrum disorders 7 whilst hypo-activation of the network has been linked to Alzheimer's and other neurodegenerative diseases 8). As such, noninvasive modulation of this network may represent a potential therapeutic intervention for a number of neurological and psychiatric pathologies linked to abnormal network activation. One possible tool to effect this modulation is Transcranial Magnetic Stimulation: a non-invasive neurostimulatory and neuromodulatory technique that can transiently or lastingly modulate cortical excitability (either increasing or decreasing it) via the application of localized magnetic field pulses.9
In order to explore the default mode network's propensity towards and tolerance of modulation, we will be combining TMS (to the left inferior parietal lobe) with functional magnetic resonance imaging (fMRI). Through this article, we will examine the protocol and considerations necessary to successfully combine these two neuroscientific tools.

In this article, we examine the methodology and considerations relevant to the combination of TMS and fMRI to examine the effects of brain stimulation on the default network.

La combinazione di stimolazione magnetica transcranica e fMRI per esaminare il modo predefinito della rete

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 ...

Ricerca

Neuroscienze

State-Dependency Effects on TMS:  A Look at Motive Phosphene Behavior

Transcranial magnetic stimulation (TMS) is a non-invasive neurostimulatory and neuromodulatory technique that can transiently or lastingly modulate cortical excitability (either increasing or decreasing it) via the application of localized magnetic field pulses.1,2 Within the field of TMS, the term state dependency refers to the initial, baseline condition of the particular neural region targeted for stimulation. As can be inferred, the effects of TMS can (and do) vary according to this primary susceptibility and responsiveness of the targeted cortical area.3,4,5

In this experiment, we will examine this concept of state dependency through the elicitation and subjective experience of motive phosphenes. Phosphenes are visually perceived flashes of small lights triggered by electromagnetic pulses to the visual cortex. These small lights can assume varied characteristics depending upon which type of visual cortex is being stimulated. In this particular study, we will be targeting motive phosphenes as elicited through the stimulation of V1/V2 and the V5/MT+ complex visual regions.6

In this article, we examine the effects of visually relevant state dependency on TMS induced motive phosphenic presentations.

Stato-dipendenza Effetti sulla TMS: uno sguardo al comportamento Motive fosfene

Transcranial magnetic stimulation (TMS) is a non-invasive neurostimulatory and neuromodulatory technique that can transiently or lastingly modulate ...

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.

L&#39;uso di Spettroscopia di Risonanza Magnetica come uno strumento per la misura della Bi-emisferici transcraniali elettrici effetti di stimolazione sul motore principale Cortex Metabolismo

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.

Effetti della stimolazione transcranica con corrente alternata la corteccia motoria primaria di approccio combinato Online con stimolazione magnetica transcranica

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

Online Transcranial Magnetic Stimulation Protocol for Measuring Cortical Physiology Associated with Response Inhibition

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) characterization of primary motor cortex (M1) excitability and inhibition. Motor response inhibition prevents unwanted actions and is abnormal in several neuropsychiatric conditions. TMS is a non-invasive technology that can quantify M1 excitability and inhibition using single- and paired-pulse protocols and can be precisely timed to study cortical physiology with high temporal resolution. We modified the original Slater-Hammel (S-H) stop signal task to create a &#34;racecar&#34; version with TMS pulses time-locked to intra-trial events. This task is self-paced, with each trial initiating after a button push to move the racecar towards the 800 ms target. GO trials require a finger-lift to stop the racecar just before this target. Interspersed randomly are STOP trials (25%) during which the dynamically adjusted stop signal prompts subjects to prevent finger-lift. For GO trials, TMS pulses were delivered at 650 ms after trial onset; whereas, for STOP trials, the TMS pulses occurred 150 ms after the stop signal. The timings of the TMS pulses were decided based on electroencephalography (EEG) studies showing event-related changes in these time ranges during stop signal tasks. This task was studied in 3 blocks at two study sites (n=38) and we recorded behavioral performance and event-related motor-evoked potentials (MEP). Regression modelling was used to analyze MEP amplitudes using age as a covariate with multiple independent variables (sex, study site, block, TMS pulse condition [single- vs. paired-pulse], trial condition [GO, successful STOP, failed STOP]). The analysis showed that TMS pulse condition (p&#60;0.0001) and its interaction with trial condition (p=0.009) were significant. Future applications for this online S-H/TMS paradigm include the addition of simultaneous EEG acquisition to measure TMS-evoked EEG potentials. A potential limitation is that in children, the TMS pulse sound could&#160;affect behavioral task performance.

We describe an experimental procedure to quantify excitability and inhibition of primary motor cortex during a motor response inhibition task by using Transcranial Magnetic Stimulation throughout the course of a Stop Signal Task.

Protocollo di stimolazione magnetica transcranica online per misurare la fisiologia corticale associata con l'inibizione di risposta

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) ...

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.

Stimolazione magnetica transcranica combinata e l'elettroencefalografia della corteccia prefrontale dorsolaterale

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.

Valutazione bilaterale delle vie Corticospinal dei muscoli della caviglia utilizzando navigato la stimolazione magnetica transcranica

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 ...

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.

Impiegare la stimolazione magnetica transcranica in un ambiente con risorse limitate per stabilire relazioni cervello-comportamento

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.

Test di stimolazione magnetica transcranica convenzionali e con tracciamento delle soglie per il funzionamento con una sola mano

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

Measuring Contralateral Silent Period Induced by Single-Pulse Transcranial Magnetic Stimulation to Investigate M1 Corticospinal Inhibition

Contralateral silent period (cSP) is a period of suppression in the background electrical muscle activity captured by electromyography (EMG) after a motor evoked potential (MEP). To obtain this, an MEP is elicited by a suprathreshold transcranial magnetic stimulation (TMS) pulse delivered to the primary motor cortex (M1) of the target muscle selected, while the participant provides a standardized voluntary target muscle contraction. The cSP is a result of inhibitory mechanisms that occur after the MEP; it provides a broad temporal assessment of spinal inhibition in its initial ~50 ms, and cortical inhibition after. Researchers have tried to better understand the neurobiological mechanism behind the cSP to validate it as a potential diagnostic, surrogate, and predictive biomarker for different neuropsychiatric diseases. Therefore, this article describes a method to measure M1 cSP of lower and upper limbs, including a selection of target muscle, electrode placement, coil positioning, method of measuring voluntary contraction stimulation, intensity setup, and data analysis to obtain a representative result. It has the educational objective of giving a visual guideline in performing a feasible, reliable, and reproducible cSP protocol for lower and upper limbs and discussing practical challenges of this technique.

Contralateral silent period (cSP) assessment is a promising biomarker to index cortical excitability and treatment response. We demonstrate a protocol to assess cSP intended for studying M1 corticospinal inhibition of upper and lower limbs.

Misurazione del periodo di silente controlaterale indotto dalla stimolazione magnetica transcranica a impulso singolo per studiare l'inibizione corticospinale M1

Contralateral silent period (cSP) is a period of suppression in the background electrical muscle activity captured by electromyography (EMG) after a motor ...