Localizing Function-specific Targets for Transcranial Magnetic Stimulation in the Absence of Navigation Equipment

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Medical Imaging

Background:

• Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain modulation technique used for neuropsychiatric disorders like stroke.
• Current rTMS efficacy in stroke rehabilitation is limited by traditional hand motor hotspot localization methods.
• Motor evoked potentials (MEPs) reflect corticospinal tract conductivity, not voluntary movement, hindering precise rTMS targeting.

Purpose of the Study:

• To introduce the concept of function-specific targets identified via functional magnetic resonance imaging (fMRI) for enhanced rTMS.
• To validate function-specific targets for superior functional connectivity and regulatory effects compared to traditional hotspots.
• To develop a non-navigated localization method for function-specific targets in post-stroke patients, increasing accessibility.

Main Methods:

• Utilized fMRI to identify function-specific targets based on voluntary motor task activation.
• Compared functional connectivity of function-specific targets with motor cognition regions against traditional hotspots.
• Developed and validated a novel non-navigated method for localizing these targets in the ipsilesional hemisphere post-stroke.

Main Results:

• Function-specific targets demonstrate stronger and more extensive functional connectivity with motor cognition areas.
• The developed non-navigated method enables precise localization of function-specific targets without navigation equipment.
• This approach addresses accessibility barriers for institutions lacking advanced imaging navigation systems.

Conclusions:

• Function-specific targets offer a more effective approach for rTMS in stroke rehabilitation compared to traditional hotspots.
• The novel non-navigated localization method significantly expands the applicability of function-specific targeted rTMS.
• This innovation democratizes access to advanced rTMS techniques for stroke recovery.