Ipsi- and contralateral EEG reactions to transcranial magnetic stimulation

Komssi, Soile; Aronen, Hannu J.; Huttunen, J.; Kesäniemi, Martti; Soinne, Lauri; Nikouline, Vadim V.; Ollikainen, Marko; Roine, Risto O.; Karhu, Jari; Savolainen, Sauli; Ilmoniemi, Risto J.

doi:10.1016/s1388-2457(01)00721-0

Cited by 203 publications

(196 citation statements)

References 36 publications

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“…This result is consistent with a recent study (Zheng et al, 2011) that reports a positive correlation between the stimulated motor cortex and the contralateral one, supporting a possible coupling of neuroactivity between motor regions (although in our study, the stimulated hemisphere was more strongly activated than the contralateral region). We suppose that the mechanisms responsible for this widespread and bihemispheric anodal effect Pena-Gomez et al, 2011;Polania et al, 2010b) could involve current flowing in subcortical regions such as the thalamus (Bindman et al, 1962), which is the principal subcortical mediator of the TMS-contralateral response (Komssi et al, 2002). A tDCS-induced effect on the cortico-subcortical networks is supported also by recent evidence of a functional coupling increase on the thalamo-cortical circuits following anodal stimulation over the motor cortex (Polania et al, 2012).…”

Section: Tdcs-induced Changes In Cortical Excitabilitymentioning

confidence: 71%

Excitability modulation of the motor system induced by transcranial direct current stimulation: A multimodal approach

2013

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Anodal and cathodal transcranial direct current stimulations (tDCS) are both established techniques to induce cortical excitability changes. Typically, in the human motor system, such cortical modulations are inferred through changes in the amplitude of the motor evoked potentials (MEPs). However, it is now possible to directly evaluate tDCS-induced changes at the cortical level by recording the transcranial magnetic stimulation evoked potentials (TEPs) using electroencephalography (EEG). The present study investigated the modulation induced by the tDCS on the motor system. The study evaluates changes in the MEPs, in the amplitude and distribution of the TEPs, in resting state oscillatory brain activity and in behavioral performance in a simple manual response task. Both the short-and long-term tDCS effects were investigated by evaluating their time course at~0 and 30 min after tDCS. Anodal tDCS over the left primary motor cortex (M1) induced an enhancement of corticospinal excitability, whereas cathodal stimulation produced a reduction. These changes in excitability were indexed by changes in MEP amplitude. More interestingly, tDCS modulated the cortical reactivity, which is the neuronal activity evoked by TMS, in a polarity-dependent and site-specific manner. Cortical reactivity increased after anodal stimulation over the left M1, whereas it decreased with cathodal stimulation. These effects were partially present also at long term evaluation. No polarity-specific effect was found either on behavioral measures or on oscillatory brain activity. The latter showed a general increase in the power density of low frequency oscillations (theta and alpha) at both stimulation polarities. Our results suggest that tDCS is able to modulate motor cortical reactivity in a polarity-specific manner, inducing a complex pattern of direct and indirect cortical activations or inhibitions of the motor system-related network, which might be related to changes in synaptic efficacy of the motor cortex.

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Section: Tdcs-induced Changes In Cortical Excitabilitymentioning

confidence: 71%

Excitability modulation of the motor system induced by transcranial direct current stimulation: A multimodal approach

2013

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“…In their study, TMS was combined with EMG, which gives only indirect evidence about the excitability of the motor cortex, because these responses might be modulated by spinal mechanisms (Morita et al, 1999;Nielsen et al, 1999a, b). In contract to this, we used the combination of TMS and EEG, which provides direct information about cortical excitability after stimulation of different sites (Ilmoniemi et al, 1997;Kähkönen et al, 2001aKähkönen et al, , b, 2002Komssi et al, 2002).…”

Section: Discussionmentioning

confidence: 99%

“…Recently, TMS has been combined with electroencephalography (EEG) (Ilmoniemi et al, 1997;Kähkönen et al, 2001a, b;Komssi et al, 2002). With this approach, we have recently shown that acute alcohol ingestion is associated with alteration in excitability and functional connections of the motor cortex (Kähkönen et al, 2001a).…”

Section: Introductionmentioning

confidence: 99%

Alcohol Reduces Prefrontal Cortical Excitability in Humans: A Combined TMS and EEG Study

Kähkönen

Wilenius

Nikulin

et al. 2002

Neuropsychopharmacol

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The effects of alcohol (0.8 g/kg) on the prefrontal cortex were studied in nine healthy subjects using the technique of transcranial magnetic stimulation (TMS) combined with electroencephalography (EEG). A total of 120 magnetic pulses were delivered with a figureof-eight coil to the left prefrontal cortex at the rate of 0.4-0.7 Hz. The EEG was recorded simultaneously with 60 scalp electrodes (41 electrodes were used for analysis); the TMS-evoked activation was estimated by the area under the global mean field amplitude (GMFA) time curve. TMS caused changes in EEG activity lasting up to 270 ms poststimulus. Alcohol decreased GMFA at 30-270 ms poststimulus (713 7 303 vs 478 7 142 mV ms; p ¼ 0.007). Alcohol-induced differences were most pronounced at anterior electrodes. These results suggest that alcohol reduces the excitability in the prefrontal cortex.

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“…This, in turn, is affected by corticocortical, thalamocortical, and interhemispheric connections. [21][22][23][24] Thus, nTMS-EEG is potentially sensitive to pathological changes in cortical excitability and connectivity.…”

Section: Introductionmentioning

confidence: 99%

“…A TMS-induced artifact can mask the early EEG deflections, 25 for which reason P30 has often been the earliest reliably measured peak. P30 seems to have a diffuse origin and is thought to be related to early spread of activation to more distant and contralateral areas, 21,25,26 In clinical experiments, preliminary evidence of altered P30 amplitudes has been found in Alzheimer's disease, with significantly decreased amplitudes at the 30-50 msec time range. 27 TMS-evoked N45 is generated by a dipole close to the stimulation site, when stimulating M1.…”

Section: Introductionmentioning

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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Ipsi- and contralateral EEG reactions to transcranial magnetic stimulation

Cited by 203 publications

References 36 publications

Excitability modulation of the motor system induced by transcranial direct current stimulation: A multimodal approach

Excitability modulation of the motor system induced by transcranial direct current stimulation: A multimodal approach

Alcohol Reduces Prefrontal Cortical Excitability in Humans: A Combined TMS and EEG Study

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

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