Phantom Quantification of Magnetoencephalography Source Imaging Distortion Caused by Deep Brain Stimulation

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Physics

Background:

• Deep brain stimulation (DBS) is crucial for treating neurological disorders.
• Magnetoencephalography (MEG) measures brain activity but can be affected by DBS artifacts.
• Understanding DBS effects on source-level MEG analysis is critical for accurate neuroscientific interpretation.

Purpose of the Study:

• To quantify the distortion of source-level MEG imaging caused by deep brain stimulation (DBS) artifacts.
• To assess the impact of varying stimulation amplitude, electrode configuration, and proximity on DBS-related MEG distortions.
• To evaluate the stability of head position indicator (HPI) coil signals during DBS.

Main Methods:

• Utilized a phantom-based experimental setup to simulate DBS and MEG recordings.
• Systematically varied DBS stimulation amplitude (mA), electrode configuration, and dipole-DBS electrode distance.
• Analyzed dipole-fitting accuracy (location, angle, amplitude) and HPI coil signal quality.

Main Results:

• Dipole location, angle, and amplitude errors were modest across tested conditions.
• Largest errors occurred at 5 mA ring-electrode stimulation (location/angle) and 15 mA (amplitude).
• Error increased significantly with proximity to the DBS electrode; HPI signals remained stable.

Conclusions:

• DBS stimulation itself does not significantly impair MEG dipole estimation accuracy.
• The study provides a quantitative framework for assessing DBS-related MEG distortions.
• This framework can be adapted to evaluate interference from other implanted or external devices.