Transcranial direct current stimulation with functional magnetic resonance imaging: a detailed validation and...

Area of Science:

• Neuroscience
• Medical Imaging
• Brain Stimulation

Background:

• Transcranial direct current stimulation (tDCS) modulates brain activity for research and clinical use.
• Combining tDCS with functional magnetic resonance imaging (fMRI) allows direct investigation of brain region causality.
• Technical challenges and variability hinder the comparability and replicability of tDCS-fMRI studies.

Purpose of the Study:

• To develop and validate a reliable tDCS-fMRI method at 3 Tesla for studying language recovery post-stroke.
• To address technical challenges and methodological variability in tDCS-fMRI applications.
• To provide a Standard Operating Procedure (SOP) to promote replication and enhance data quality.

Main Methods:

• Developed a tDCS-fMRI protocol at 3T.
• Validated the method using a healthy volunteer in three conditions: No-tDCS, Sham-tDCS, and Anodal-tDCS.
• Analyzed MR data using region-of-interest (ROI) analyses, modeling scanner drift, motion, and temporal autocorrelation.

Main Results:

• No visible signal dropouts or distortions were observed due to tDCS equipment.
• Functional MR sensitivity remained unaffected across conditions in grey matter and ROIs.
• The tDCS set-up and stimulation protocol did not degrade MR data quality.

Conclusions:

• The developed tDCS-fMRI procedure is technically safe and reliable for acquiring high-quality MR data.
• The detailed SOP facilitates adoption and replication in future studies.
• This approach enhances the quality and reliability of tDCS-fMRI research.