TY - JOUR
T1 - Pre-Stimulus Power but Not Phase Predicts Prefrontal Cortical Excitability in TMS-EEG
AU - Poorganji, Mohsen
AU - Zomorrodi, Reza
AU - Zrenner, Christoph
AU - Bansal, Aiyush
AU - Hawco, Colin
AU - Hill, Aron T.
AU - Hadas, Itay
AU - Rajji, Tarek K.
AU - Chen, Robert
AU - Zrenner, Brigitte
AU - Voineskos, Daphne
AU - Blumberger, Daniel M.
AU - Daskalakis, Zafiris J.
N1 - Publisher Copyright:
© 2023 by the authors.
PY - 2023/2/1
Y1 - 2023/2/1
N2 - The cortical response to transcranial magnetic stimulation (TMS) has notable inter-trial variability. One source of this variability can be the influence of the phase and power of pre-stimulus neuronal oscillations on single-trial TMS responses. Here, we investigate the effect of brain oscillatory activity on TMS response in 49 distinct healthy participants (64 datasets) who had received single-pulse TMS over the left dorsolateral prefrontal cortex. Across all frequency bands of theta (4–7 Hz), alpha (8–13 Hz), and beta (14–30 Hz), there was no significant effect of pre-TMS phase on single-trial cortical evoked activity. After high-powered oscillations, whether followed by a TMS pulse or not, the subsequent activity was larger than after low-powered oscillations. We further defined a measure, corrected_effect, to enable us to investigate brain responses to the TMS pulse disentangled from the power of ongoing (spontaneous) oscillations. The corrected_effect was significantly different from zero (meaningful added effect of TMS) only in theta and beta bands. Our results suggest that brain state prior to stimulation might play some role in shaping the subsequent TMS-EEG response. Specifically, our findings indicate that the power of ongoing oscillatory activity, but not phase, can influence brain responses to TMS. Aligning the TMS pulse with specific power thresholds of an EEG signal might therefore reduce variability in neurophysiological measurements and also has the potential to facilitate more robust therapeutic effects of stimulation.
AB - The cortical response to transcranial magnetic stimulation (TMS) has notable inter-trial variability. One source of this variability can be the influence of the phase and power of pre-stimulus neuronal oscillations on single-trial TMS responses. Here, we investigate the effect of brain oscillatory activity on TMS response in 49 distinct healthy participants (64 datasets) who had received single-pulse TMS over the left dorsolateral prefrontal cortex. Across all frequency bands of theta (4–7 Hz), alpha (8–13 Hz), and beta (14–30 Hz), there was no significant effect of pre-TMS phase on single-trial cortical evoked activity. After high-powered oscillations, whether followed by a TMS pulse or not, the subsequent activity was larger than after low-powered oscillations. We further defined a measure, corrected_effect, to enable us to investigate brain responses to the TMS pulse disentangled from the power of ongoing (spontaneous) oscillations. The corrected_effect was significantly different from zero (meaningful added effect of TMS) only in theta and beta bands. Our results suggest that brain state prior to stimulation might play some role in shaping the subsequent TMS-EEG response. Specifically, our findings indicate that the power of ongoing oscillatory activity, but not phase, can influence brain responses to TMS. Aligning the TMS pulse with specific power thresholds of an EEG signal might therefore reduce variability in neurophysiological measurements and also has the potential to facilitate more robust therapeutic effects of stimulation.
KW - EEG power before TMS
KW - TMS-EEG
KW - brain state
KW - cortical oscillations
KW - phase before TMS
UR - http://www.scopus.com/inward/record.url?scp=85148963749&partnerID=8YFLogxK
U2 - 10.3390/bios13020220
DO - 10.3390/bios13020220
M3 - Article
C2 - 36831986
AN - SCOPUS:85148963749
SN - 2079-6374
VL - 13
JO - Biosensors
JF - Biosensors
IS - 2
M1 - 220
ER -