Test-retest reliability of early TMS-evoked potentials over fMRI-based definitions of non-motor targets.

OBJECTIVE

This study assessed the test-retest reliability of TMS-evoked potentials (TEPs) across two cortical regions-dorsolateral prefrontal cortex (DLPFC), and angular gyrus-in comparison to motor cortex (M1), using individualized and literature-based targeting approaches. The study also compared the reliability of different double-pulse TMS protocols.

METHODS

Seventeen healthy participants underwent two TMS-EEG sessions spaced by at least one week, with targets for DLPFC and angular gyrus identified using resting-state functional connectivity (RS) and Neurosynth-based functional overlays.

RESULTS

M1 demonstrated the highest TEP reliability (Concordance Correlation Coefficient (CCC) mean = 0.59), while DLPFC (CCCmean = 0.40) and angular gyrus (CCCmean = 0.45) showed lower reliability, particularly for anterior DLPFC targets. Neurosynth-based DLPFC targets exhibited slightly higher CCC values (mean CCC = 0.57) compared to RS-based targets (mean CCC = 0.30), but the difference was not statistically significant. No significant differences in reliability were found across TMS protocols.

CONCLUSION

While fMRI-based targeting optimizes the engagement of functional networks, TMS-EEG needs to prioritize signal-to-noise ratio (SNR) to minimize artifacts and maximize reliability.

SIGNIFICANCE: This work bridges the gap between fMRI-guided targeting and TMS-EEG applications.