Prefrontal transcranial magnetic stimulation changes cortical excitability across local and distributed brain regions.

OBJECTIVE

This study sort to identify the continuous effects of repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC-rTMS) on local and distributed brain activities.

METHODS

In a double-blinded and sham-controlled design, 24 participants received either a real or sham DLPFC-rTMS session, with concurrent TMS-EEG being recorded at baseline, 5 and 60 min after stimulation.

RESULTS

DLPFC stimulation induced immediate cortical excitability in the frontal regions, while a continuous effect was identified in the parietal cortex for up to 60 min. Moreover, this pattern of cortical excitability effects was reliably identified across TMS-induced field potentials and oscillations.

CONCLUSIONS

Single-session DLPFC stimulation induced both immediate and continuous cortical excitability effects for at least 60 min. The continuous cortical excitability change. was most prominent over the parietal cortices.

SIGNIFICANCE: These novel findings may inform the design of TMS treatment paradigms to optimise cortical excitability and potentially clinical efficacy.