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

Nardo, D., Creasey, M., Negus, C., Pappa, K. , Reid, A., Josephs, O., Callaghan, M. F. and Crinion, J. T. (2023) Transcranial direct current stimulation with functional magnetic resonance imaging: a detailed validation and operational guide. Wellcome Open Research, 6, 143. (doi: 10.12688/wellcomeopenres.16679.2) (PMID:37008187) (PMCID:PMC10050906)

Abstract

Introduction: Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique used to modulate human brain and behavioural function in both research and clinical interventions. The combination of functional magnetic resonance imaging (fMRI) with tDCS enables researchers to directly test causal contributions of stimulated brain regions, answering questions about the physiology and neural mechanisms underlying behaviour. Despite the promise of the technique, advances have been hampered by technical challenges and methodological variability between studies, confounding comparability/replicability. Methods: Here tDCS-fMRI at 3T was developed for a series of experiments investigating language recovery after stroke. To validate the method, one healthy volunteer completed an fMRI paradigm with three conditions: No-tDCS, Sham-tDCS, Anodal-tDCS. MR data were analysed with region-of-interest (ROI) analyses of the electrodes and reference site. Results: Quality assessment indicated no visible signal dropouts or distortions in the brain introduced by the tDCS equipment. After modelling scanner drift, motion-related variance, and temporal autocorrelation, we found that functional MR sensitivity was not degraded or adversely affected by the tDCS set-up and stimulation protocol across conditions in grey matter and in the three ROIs. Discussion: Key safety factors and risk mitigation strategies that must be taken into consideration when integrating tDCS into an fMRI environment are outlined. To obtain reliable results, we provide practical solutions to technical challenges and complications of the method. It is hoped that sharing these data and Standard Operation Procedure (SOP) will promote methodological replication in future studies, enhancing the quality of tDCS-fMRI application, and improve the reliability of scientific results in this field. Conclusions: Our method and data provide a technically safe, reliable tDCS-fMRI procedure to obtain high quality MR data. The detailed framework of the SOP systematically reports the technical and procedural elements of our tDCS-fMRI approach, which can be adopted and prove useful in future studies.

• Item Type: Articles
• Additional Information: Version 2; peer review: 1 approved, 3 approved with reservations. This work was supported by the Wellcome Trust [106161 to JC, 203147 to WCHN].
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Pappa, Mrs Aikaterini

Creator Roles

Pappa, K.: Investigation, Methodology, Project administration, Writing – original draft

• Authors: Nardo, D., Creasey, M., Negus, C., Pappa, K., Reid, A., Josephs, O., Callaghan, M. F., and Crinion, J. T.
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Mental Health and Wellbeing
• Journal Name: Wellcome Open Research
• Publisher: F1000Research
• ISSN: 2398-502X
• ISSN (Online): 2398-502X
• Published Online: 07 June 2021
• Copyright Holders: Copyright © 2021 Nardo D et al.
• First Published: First published in Wellcome Open Research 6: 143
• Publisher Policy: Reproduced under a Creative Commons License