Matching Corticospinal and Cortical Excitability along the motor cortex: TMS-EMG-EEG study

In 24 subjects, EEG-derived cortical excitability thresholds (CETs) and EMG-derived resting motor thresholds (RMTs) are strongly correlated across hand, arm, and leg hotspots in M1, with both rising hand-to-leg.

• Why it matters: Default use of a hand-muscle RMT may mis-set cortical stimulation dosage because cortical and corticospinal excitability correspondence along M1 is unclear, including for subthreshold TMS.
• What they did: Using simultaneous TMS-EMG-EEG, the study measured CETs with EEG and RMTs with EMG at hand, arm, and leg hotspots in M1, then compared their location-dependent patterns.
• The result: CETs were generally lower than corresponding RMTs and differed within subjects at all three hotspots, with the CET–RMT gap increasing from hand to leg, arguing against default hand-muscle RMT dosing.

AI summary of the abstract · may contain errors · not medical advice · read the paper.