Instrumentation for the measurement of electric brain responses to transcranial magnetic stimulation

Virtanen, Juha; Ruohonen, J.; Näätänen, Risto; Ilmoniemi, Risto J.

doi:10.1007/bf02513307

Cited by 230 publications

(186 citation statements)

References 20 publications

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“…In contrast to imaging of blood oxygen level-dependent (BOLD) signals, which are inevitably slow because of their dependence on hemodynamics, we here measured neuronal activity directly as voltage changes across neuronal membranes. Commonly, immediate detection of the fluctuations in neuronal membrane potentials suffers from artifacts introduced by the TMS coil discharge, leading to overload of recording amplifiers around the time point of TMS pulses (22,36) and masking of neuronal effects, which can gradually be reduced by only advanced technologies (50)(51)(52)(53). Obviously, VSD imaging does not provide single-cell resolution and is limited to cortical surface areas.…”

Section: Discussionmentioning

confidence: 99%

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

Kozyrev

Eysel

Jancke

2014

Proc. Natl. Acad. Sci. U.S.A.

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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. (1) (TMS) has become a frequently used method for noninvasive diagnostics, therapeutic treatment, and intervention for neurorehabilitation of neurological disorders (2-8). Additionally, TMS has proved a valuable tool in basic brain research as its perturbative effects allow area-selective manipulation of immediate cortical function (9-11), as well as its long-lasting alteration through plasticity and learning protocols (12, 13). However, direct measurements of the TMS-induced cortical dynamics at highly resolved spatiotemporal scales are missing because "online approaches" (14), using modern neuroimaging techniques such as functional MRI (fMRI) (15-18), magnetoencephalography (19), EEG (20), and near-infrared (21) or intrinsic optical imaging (22), are limited in either spatial or temporal resolutions or in both.Here we overcame these limitations, using optical imaging with voltage-sensitive dyes (VSD), which exploits the dye's property to transduce gradual changes in voltage across neuronal membranes into fluorescent light signals. In contrast to imaging methods applicable in humans, this method is invasive but allows avoiding the commonly experienced contamination of signals by artifacts due to the strong ...

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Section: Discussionmentioning

confidence: 99%

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

Kozyrev

Eysel

Jancke

2014

Proc. Natl. Acad. Sci. U.S.A.

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“…During TMS pulses, the amplifier was gated by sample-and-hold circuit for 2 msec to remove most of the TMS-induced artifact. 39 …”

Section: Eeg Acquisitionmentioning

confidence: 99%

Transcranial Magnetic Stimulation-Electroencephalography Responses in Recovered and Symptomatic Mild Traumatic Brain Injury

Tallus

Lioumis

Hämäläinen

et al. 2013

Journal of Neurotrauma

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Mild traumatic brain injury (mTBI) may cause diffuse damage to the brain, especially to the frontal areas, that may lead to persistent symptoms. We studied participants with past mTBI by means of navigated transcranial magnetic stimulation (nTMS) combined with electroencephalography (EEG). Eleven symptomatic and 8 recovered participants with a history of single mTBI and 9 healthy controls participated. Average time from injury to testing was 5 years. The participants did not have abnormalities or signs of injury on brain magnetic resonance imaging, and they did not use any centrally acting medication. Left primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPFC) were stimulated with nTMS and evoked potentials measured from the corresponding areas of both hemispheres. Delayed ipsilateral P30 and contralateral N45 peak latencies to left DLPFC nTMS were found in the symptomatic group, along with higher DLPFC N100 amplitudes compared with the control or recovered group. The recovered group had shorter P200 latencies in left DLPFC nTMS compared with the other groups. Both mTBI groups had higher motor thresholds compared with the control group. In left M1 nTMS, the mTBI groups showed less P30 amplitude increase, and the symptomatic group showed longer P60 interhemispheric latency difference with higher stimulation intensities. The results suggest altered brain reactivity and connectivity in mTBI. Some of the observed differences may be related to compensatory mechanisms of recovery. nTMS-EEG is a potentially useful tool for studying the effects of mTBI.

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“…However, these early attempts were not replicated immediately, probably because of the various technical limitations. Indeed, voltage changes induced by the TMS pulse between scalp electrodes are six orders of magnitude larger than microvolt-level EEG signals [42]. Such high voltage levels can lead to the saturation of a standard EEG amplifier, which can last for hundreds of milliseconds.…”

Section: Tms-eeg Coregistrationmentioning

confidence: 99%

“…In recent years, the development of new technologies and solutions has gradually led to an improvement of the temporal resolution of EEG recording during TMS. Such strategies can be divided in two types: on-line strategies, which consists of the creation of technologies that are able to avoid saturating the EEG amplifiers during TMS (e.g., [42]) and off-line strategies, which aim to remove artefacts once the coregistration is completed (e.g., [44,68]). …”

Section: Technical Issuesmentioning

confidence: 99%

“…The 60-channel EEG system developed by Virtanen group [42], guaranteed its TMScompatibility through the use of gain-control and sample-and-hold circuits, which permit the locking of EEG signals for several milliseconds (i.e., "gating period") immediately post-TMS. This technology avoids the saturation of the recording by preventing the passage of the artefact along the amplifier circuits.…”

Section: Technical Issuesmentioning

confidence: 99%

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Transcranial Magnetic Stimulation and Neuroimaging Coregistration

Casula¹,

Tarantino²,

Basso³

et al. 2013

Novel Frontiers of Advanced Neuroimaging

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The development of neuroimaging techniques is one of the most impressive advancements in neuroscience. The main reason for the widespread use of these instruments lies in their capacity to provide an accurate description of neural activity during a cognitive process or during rest. This important advancement is related to the possibility to selectively detect changes of neuronal activity in space and time by means of different biological markers. Specifically, functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and nearinfrared spectroscopy (NIRS) use metabolic markers of ongoing neuronal activity to provide an accurate description of the activation of specific brain areas with high spatial resolution. Similarly, electroencephalography (EEG) is able to detect electric markers of neuronal activity, providing an accurate description of brain activation with high temporal resolution. The application of these techniques during a cognitive task allows important inferences regarding the relation between the detected neural activity, the cognitive process involved in an ongoing task, and behaviour: this is known as a “correlational approach”

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Instrumentation for the measurement of electric brain responses to transcranial magnetic stimulation

Cited by 230 publications

References 20 publications

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

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

Transcranial Magnetic Stimulation-Electroencephalography Responses in Recovered and Symptomatic Mild Traumatic Brain Injury

Transcranial Magnetic Stimulation and Neuroimaging Coregistration

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