Subcortical substrates of TMS induced modulation of the cortico-cortical connectivity

Content Provider	Semantic Scholar
Author	Groppa, Sergiu Muthuraman, Muthuraman Otto, Birte Deuschl, Guenther Raethjen, Jan
Copyright Year	2013
Abstract	BACKGROUND Transcranial magnetic stimulation (TMS) can modulate transiently the physiological brain oscillations, e.g. the alpha rhythm. It has been hypothesized that this effect is not limited to the stimulated region but involves subcortical and distant cortical areas. METHODS We applied single pulse TMS to the primary motor cortex (M1) of healthy subjects to interfere the cortical oscillatory activity recorded by simultaneous EEG and calculated the cortico-cortical coherence and power in the alpha and beta band. To study the structural substrate of the functional connectivity we performed diffusion tensor imaging and fractional anisotropy analysis (FA). To capture the pathways involved we applied probabilistic tractography to reconstruct the entire network. RESULTS Suprathreshold TMS of M1 induced a consistent enhancement of interhemispheric cortico-cortical alpha band coherence that lasted ca. 175 ms. after the pulse has been applied. The changes were confined to the interhemispheric central EEG electrodes (i.e. C3-C4). There were no consistent changes in the beta band. Power analysis revealed a longer lasting increase in the beta band after TMS pulses. A cluster in the contralateral thalamus showed a linear relationship between regional FA and TMS induced change in alpha band coherence. Probabilistic tractography presents the transcallosal and the contralateral thalamocortical pathways as essential for the observed oscillatory synchronisation. CONCLUSION TMS induces an enhancement of oscillatory interaction between corresponding central regions of both hemispheres in the alpha band. The contralateral thalamus, transcallosal fibres and the contralateral thalamocortical pathways may constitute critical brain structures mediating the TMS induced change in oscillatory coupling.
Starting Page	138
Ending Page	146
Page Count	9
File Format	PDF HTM / HTML
DOI	10.1016/j.brs.2012.03.014
PubMed reference number	22537867
Journal	Medline
Volume Number	6
Alternate Webpage(s)	https://api.elsevier.com/content/article/pii/S1935861X1200037X
Alternate Webpage(s)	https://www.sciencedirect.com/science/article/pii/S1935861X1200037X?dgcid=api_sd_search-api-endpoint
Alternate Webpage(s)	https://doi.org/10.1016/j.brs.2012.03.014
Journal	Brain Stimulation
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article