Dynamic aftereffects in supplementary motor network following inhibitory transcranial magnetic stimulation protocols

• Published in: NeuroImage (Orlando, Fla.) Vol. 149; pp. 285 - 294
• Main Authors: Ji, Gong-Jun, Yu, Fengqiong, Liao, Wei, Wang, Kai
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2017; Elsevier Limited
• Subjects: Achievement tests; Blindness; Brain; Brain mapping; Cortex (cingulate); Cross-Over Studies; Datasets; Design; Dynamic; Electromyography; Experiments; Female; Frontal gyrus; Functional magnetic resonance imaging; functional MRI; Healthy subject; Humans; Image Interpretation, Computer-Assisted; Magnetic fields; Magnetic Resonance Imaging; Male; Motor Cortex - physiology; Motor task performance; Movement disorders; Nervous system; Neural networks; Neuroimaging; Neuronavigation - methods; Neurosciences; NMR; Nuclear magnetic resonance; Resting-state; Single-Blind Method; Supplementary motor area; Temporal lobe; Theta burst stimulation; Transcranial magnetic stimulation; Transcranial Magnetic Stimulation - methods; Young Adult; functional MRI; Theta burst stimulation; Resting-state; Dynamic; Transcranial magnetic stimulation; Healthy subject
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2017.01.035

The supplementary motor area (SMA) is a key node of the motor network. Inhibitory repetitive transcranial magnetic stimulation (rTMS) of the SMA can potentially improve movement disorders. However, the aftereffects of inhibitory rTMS on brain function remain largely unknown. Using a single-blind, crossover within-subject design, we investigated the role of aftereffects with two inhibitory rTMS protocols [1800 pulses of either 1-Hz repetitive stimulation or continuous theta burst stimulation (cTBS)] on the left SMA. A total of 19 healthy volunteers participated in the rTMS sessions on 2 separate days. Firstly, short-term aftereffects were estimated at three levels (functional connectivity, local activity, and network properties) by comparing the resting-state functional magnetic resonance imaging datasets (9min) acquired before and after each rTMS session. Local activity and network properties were not significantly altered by either protocol. Functional connectivity within the SMA network was increased (in the left paracentral gyrus) by 1-Hz stimulation and decreased (in the left inferior frontal gyrus and SMA/middle cingulate cortex) by cTBS. The subsequent three-way analysis of variance (site×time×protocol) did not show a significant interaction effect or “protocol” main effect, suggesting that the two protocols share an underlying mechanism. Secondly, sliding-window analysis was used to evaluate the dynamic features of aftereffects in the ~29min after the end of stimulation. Aftereffects were maintained for a maximum of 9.8 and 6.6min after the 1-Hz and cTBS protocols, respectively. In summary, this study revealed topographical and temporal aftereffects in the SMA network following inhibitory rTMS protocols, providing valuable information for their application in future neuroscience and clinical studies. •1Hz and continuous TBS can modulate the function of SMA network.•1Hz repetitive TMS increased the functional connectivity of paracentral gyrus.•Continuous TBS decreased the functional connectivity of IFG, SMA/MCC.•The two protocols show similar effective time (~10min) after the end of stimulation.