Finger Tapping Task Activation vs. TMS Hotspot: Different Locations and Networks.

Area of Science:

• Neuroscience
• Motor Control
• Brain Imaging

Background:

• Functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) are non-invasive tools for localizing human motor areas.
• Clinical applications of TMS treatment often use these localized areas as stimulation targets.
• Previous studies noted discrepancies between finger tapping fMRI activation and TMS hotspots.

Purpose of the Study:

• To quantify the spatial distance between finger tapping fMRI activation and TMS hotspots.
• To compare the functional brain networks associated with each localization method using resting-state fMRI.
• To inform optimal targeting strategies for TMS in clinical applications.

Main Methods:

• Thirty healthy participants underwent resting-state fMRI, task-based fMRI (finger tapping), and TMS hotspot localization.
• Spatial distance analysis was performed between fMRI activation peaks and TMS hotspots.
• Resting-state functional connectivity was analyzed using fMRI activation peaks and TMS hotspots as seeds.

Main Results:

• A significant spatial difference was observed between finger tapping fMRI activation and TMS hotspots.
• Finger tapping fMRI activation was located more laterally within the premotor area compared to the TMS hotspot.
• Resting-state fMRI revealed more intensive functional connectivity for the fMRI activation peak with areas including the premotor cortex, insula, putamen, and globus pallidus.

Conclusions:

• The study highlights spatial and network differences between fMRI-identified motor areas and TMS hotspots.
• Targeting TMS based on fMRI activation may yield broader network effects.
• This approach could potentially improve TMS efficacy for treating movement disorders.