scholarly journals Pre-stimulus Alpha Oscillations and Inter-subject Variability of Motor Evoked Potentials in Single- and Paired-Pulse TMS Paradigms

2016 ◽  
Vol 10 ◽  
Author(s):  
Zafer Iscan ◽  
Maria Nazarova ◽  
Tommaso Fedele ◽  
Evgeny Blagovechtchenski ◽  
Vadim V. Nikulin
Keyword(s):  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Alpha Oscillations ◽  
Paired Pulse ◽  
Subject Variability

scholarly journals Cortico-cortical and motor evoked potentials to single and paired-pulse stimuli: An exploratory transcranial magnetic and intracranial electric brain stimulation study

2016 ◽  
Vol 37 (11) ◽  
pp. 3767-3778 ◽  
Author(s):  
Sébastien Boulogne ◽  
Nathalie Andre-Obadia ◽  
Vasilios K Kimiskidis ◽  
Philippe Ryvlin ◽  
Sylvain Rheims
Keyword(s):  
Evoked Potentials ◽  
Brain Stimulation ◽  
Motor Evoked Potentials ◽  
Paired Pulse ◽  
Electric Brain Stimulation

scholarly journals Preconditioning Stimulus Intensity Alters Paired-Pulse TMS Evoked Potentials

2021 ◽  
Vol 11 (3) ◽  
pp. 326 ◽  
Author(s):  
Vishal Rawji ◽  
Isabella Kaczmarczyk ◽  
Lorenzo Rocchi ◽  
Po-Yu Fong ◽  
John C. Rothwell ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Stimulus Intensity ◽  
Motor Evoked Potentials ◽  
Single Pulse ◽  
Significant Negative Correlation ◽  
Intracortical Inhibition ◽  
Cortical Function ◽  
Paired Pulse ◽  
Resting Motor Threshold ◽  
Statistical Trends

Motor cortex (M1) paired-pulse TMS (ppTMS) probes excitatory and inhibitory intracortical dynamics by measurement of motor-evoked potentials (MEPs). However, MEPs reflect cortical and spinal excitabilities and therefore cannot isolate cortical function. Concurrent TMS-EEG has the ability to measure cortical function, while limiting peripheral confounds; TMS stimulates M1, whilst EEG acts as the readout: the TMS-evoked potential (TEP). Whilst varying preconditioning stimulus intensity influences intracortical inhibition measured by MEPs, the effects on TEPs is undefined. TMS was delivered to the left M1 using single-pulse and three, ppTMS paradigms, each using a different preconditioning stimulus: 70%, 80% or 90% of resting motor threshold. Corticospinal inhibition was present in all three ppTMS conditions. ppTMS TEP peaks were reduced predominantly under the ppTMS 70 protocol but less so for ppTMS 80 and not at all for ppTMS 90. There was a significant negative correlation between MEPs and N45 TEP peak for ppTMS 70 reaching statistical trends for ppTMS 80 and 90. Whilst ppTMS MEPs show inhibition across a range of preconditioning stimulus intensities, ppTMS TEPs do not. TEPs after M1 ppTMS vary as a function of preconditioning stimulus intensity: smaller preconditioning stimulus intensities result in better discriminability between conditioned and unconditioned TEPs. We recommend that preconditioning stimulus intensity should be minimized when using ppTMS to probe intracortical inhibition.

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