A Checklist for Assessing the Methodological Quality of Concurrent tES-fMRI Studies (ContES Checklist): A Consensus Study and Statement

Abstract

BackgroundLow intensity transcranial electrical stimulation (tES), including alternating or direct current stimulation (tACS or tDCS), applies weak electrical stimulation to modulate brain circuits. Integration of tES with concurrent functional magnetic resonance imaging (fMRI) allows neuromodulation of brain regions while mapping network functions, therefore supporting causal studies of both brain function and tES effects. The methodology of tES-fMRI studies, including hardware and protocols, underpin any outcomes - so reporting methods in appropriate detail is required for reproducible experimental protocols. Despite the growing number of published reports, consensus-based checklists for disclosing standards of methodological details for concurrent tES-fMRI studies were not previously established.ObjectiveTo develop a consensus-based checklist of reporting standards for concurrent tES-fMRI studies to support methodological rigor, transparency, and reproducibility (ContES Checklist).MethodsA two-phase Delphi consensus process was conducted by a steering committee (SC) of 13 members and 49 expert panelists (EP) through the International Network of the tES-fMRI (INTF) Consortium. The process began with a preliminary checklist including essential items and additional recommendations developed by the SC based on a systematic review of 57 concurrent tES-fMRI studies published before January 1, 2020. In the revision phase, contributors were invited to comment, revise, or add items/recommendations to the initial checklist. Then, in the rating phase, contributors were asked to evaluate the importance of the 17 essential items and 42 additional recommendations in the final checklist. Furthermore, the state of methodological transparency and reproducibility within the 57 collected concurrent tES-fMRI studies was assessed with the proposed checklist.ResultsDuring the revision and rating phases, the EP and SC refined the checklist based on a pre-registered consensus framework and agreed upon essential items and additional recommendations, which involved three categories: (1) technological factors, (2) safety and noise tests, and (3) methodological factors. The level of adherence to the checklist varied among the 57 published concurrent tES-fMRI articles, ranging from 24% to 76%. On average, 53% of the checklist items were reported in a given article.ConclusionsIt is expected that the use of the ContES checklist will enhance the methodological reporting quality of future concurrent tES-fMRI studies and thus increase methodological transparency and reproducibility.

A checklist for assessing the methodological quality of concurrent tES-fMRI studies (ContES checklist): a consensus study and statement

“…The development of the ContES checklist by using the Delphi technique involved the following steps: (i) formation of the SC, (ii) selection of the expert panel (EP), (iii) checklist development and revision and (iv) data collection and analysis. The protocol of this study is pre-registered in OSF 66 , and its questionnaires and databases are publicly available in the study's Open Science Framework (OSF) page (https://osf.io/f9j8z/).…”

Digitizing Non-Invasive Neuromodulation Trials: Scoping Review, Process Mapping, and Recommendations from a Delphi Panel

“…We used a Delphi technique, in which comments and feedback are iteratively discussed (Hsu and Sandford, 2019), for addressing challenges and proposing recommendations for digitizing tES trials. Following recent papers (Ekhtiari et al, 2022a, 2022b), we initially convened a steering committee (SC) group, formed based on the collaborative network of the leading authors, to develop structured questionnaires with items using Five-point Likert scales or open questions (Supplementary Material - Appendix 2). The SC also provided qualitative feedback on several topics that were analyzed by the leading authors and qualitatively described here.…”

Closing the loop between brain and electrical stimulation: Towards precision neuromodulation treatments

“…However, tES inside the scanner in consecutive or concurrent approaches requires specific practical considerations [65]. A checklist was recently developed for concurrent tES-fMRI obtained from a Delphi consensus process regarding essential factors that should be checked during a concurrent tES-fMRI trial to ensure transparency, completeness of the report and to improve study replicability and general reporting practice of concurrent tES-fMRI trials [66].…”

“…This paradigm should be tested experimentally to identify potential confounds of the design. We previously performed a systematic review to propose a checklist for concurrent tES-fMRI experiments [66]. We updated our systematic review by the end of April 2022, and we found that of all currently available tES-fMRI studies, none has used a closed-loop brain stimulation protocol.…”