A Checklist for Assessing the Methodological Quality of Concurrent tES-fMRI Studies (ContES Checklist): A Consensus Study and Statement
Authors: Ekhtiari Hamed , Ghobadi-Azbari Peyman , Thielscher Axel , Antal Andrea , Li Lucia M. , Shereen A Duke , Cabral-Calderin Yuranny , Keeser Daniel , Bergmann Til Ole , Jamil Asif , Violante Ines R. , Almeida Jorge , Meinzer Marcus , Siebner Hartwig R. , Woods Adam J. , Stagg Charlotte J. , Abend Rany , Antonenko Daria , Auer Tibor , Bächinger Marc , Baeken Chris , Barron Helen C. , Chase Henry W. , Crinion Jenny , Datta Abhishek , Davis Matthew H. , Ebrahimi Mohsen , Esmaeilpour Zeinab , Falcone Brian , Fiori Valentina , Ghodratitoostani Iman , Gilam Gadi , Grabner Roland H. , Greenspan Joel D. , Groen Georg , Hartwigsen Gesa , Hauser Tobias U. , Herrmann Christoph S. , Juan Chi-Hung , Krekelberg Bart , Lefebvre Stephanie , Liew Sook-Lei , Madsen Kristoffer H. , Mahdavifar-Khayati Rasoul , Malmir Nastaran , Marangolo Paola , Martin Andrew K. , Meeker Timothy J. , Ardabili Hossein Mohaddes , Moisa Marius , Momi Davide , Mulyana Beni , Opitz Alexander , Orlov Natasza , Ragert Patrick , Ruff Christian C. , Ruffini Giulio , Ruttorf Michaela , Sangchooli Arshiya , Schellhorn Klaus , Schlaug Gottfried , Sehm Bernhard , Soleimani Ghazaleh , Tavakoli Hosna , Thompson Benjamin , Timmann Dagmar , Tsuchiyagaito Aki , Ulrich Martin , Vosskuhl Johannes , Weinrich Christiane A. , Zare-Bidoky Mehran , Zhang Xiaochu , Zoefel Benedikt , Nitsche Michael A. , Bikson Marom 
Published: December 2020

Background

Low intensity transcranial electrical stimulation (tES), including alternating or direct current stimulation (tACS or tDCS), applies weak electrical stimulation to modulate the activity of brain circuits. Integration of tES with concurrent functional magnetic resonance imaging (fMRI) allows for the mapping of neural activity during neuromodulation, supporting causal studies of both brain function and tES effects. Methodological aspects of tES-fMRI studies underpin the results, and reporting them in appropriate detail is required for reproducibility and interpretability. Despite the growing number of published reports, there are no consensus-based checklists for disclosing methodological details of concurrent tES-fMRI studies.

Objective

To develop a consensus-based checklist of reporting standards for concurrent tES-fMRI studies to support methodological rigor, transparency, and reproducibility (ContES Checklist).

Methods

A 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 circulation of a preliminary checklist of essential items and additional recommendations, developed by the SC based on a systematic review of 57 concurrent tES-fMRI studies. Contributors were then invited to suggest revisions or additions to the initial checklist. After the revision phase, contributors rated the importance of the 17 essential items and 42 additional recommendations in the final checklist. The state of methodological transparency within the 57 reviewed concurrent tES-fMRI studies was then assessed using the checklist.

Results

Experts refined the checklist through the revision and rating phases, leading to a checklist with three categories of essential items and additional recommendations: (1) technological factors, (2) safety and noise tests, and (3) methodological factors. The level of reporting of checklist items varied among the 57 concurrent tES-fMRI papers, ranging from 24% to 76%. On average, 53% of checklist items were reported in a given article.

Conclusions

Use of the ContES checklist is expected to enhance the methodological reporting quality of future concurrent tES-fMRI studies, and increase methodological transparency and reproducibility.