AUTHOR=Guleyupoglu Berkan , Febles Nicole , Minhas Preet , Hahn Christoph , Bikson Marom 

TITLE=Reduced discomfort during high-definition transcutaneous stimulation using 6% benzocaine

JOURNAL=Frontiers in Neuroengineering

VOLUME=Volume 7 - 2014

YEAR=2014

URL=https://www.frontiersin.org/journals/neuroengineering/articles/10.3389/fneng.2014.00028

DOI=10.3389/fneng.2014.00028

ISSN=1662-6443

ABSTRACT=Abstract
Background
 High-Definition transcranial Direct Current Stimulation (HD-tDCS) allows for non-invasive neuromodulation using an array of compact (approximately 1 cm2 contact area) “High-Definition” (HD) electrodes, as compared to conventional tDCS (which uses two large pads that are approximately 35cm2). In a previous transcutaneous study, we developed and validated designs for HD electrodes that reduce discomfort over >20 min session with 2 mA electrode current.
Objective
The purpose of this study was to investigate the use of a chemical pretreatment with 6% benzocaine (topical numbing agent) to further reduce subjective discomfort during transcutaneous stimulation and to allow for better sham controlled studies.
Methods
Pre-treatment with 6% benzocaine was compared with control (no pretreatment) for 22 minutes 2 mA of stimulation, with either CCNY-4 or Lectron II electroconductive gel, for both cathodal and anodal transcutaneous (forearm) stimulation (8 different combinations).
Results
 Results show that for all conditions and polarities tested, stimulation with HD electrodes is safe and well tolerated and that pretreatment further reduced subjective discomfort. 
Conclusion
Pretreatment with a mild analgesic reduces discomfort during HD-tDCS.