Transcranial DC stimulation (tDCS): a tool for double-blind sham-controlled clinical studies in brain stimulation.
OBJECTIVE
Brain polarization in the form of transcranial direct current stimulation (tDCS), which influences motor function and learning processes, has been proposed as an adjuvant strategy to enhance training effects in Neurorehabilitation. Proper testing in Neurorehabilitation requires double-blind sham-controlled study designs. Here, we evaluated the effects of tDCS and sham stimulation (SHAM) on healthy subjects and stroke patients' self-report measures of attention, fatigue, duration of elicited sensations and discomfort.


METHODS
tDCS or SHAM was in all cases applied over the motor cortex. Attention, fatigue, and discomfort were self rated by study participants using visual analog scales. Duration of perceived sensations and the ability to distinguish tDCS from Sham sessions were determined. Investigators questioning the patients were blind to the intervention type.


RESULTS
tDCS and SHAM elicited comparably minimal discomfort and duration of sensations in the absence of differences in attention or fatigue, and could not be distinguished from SHAM by study participants nor investigators.


CONCLUSIONS
Successful blinding of subjects and investigators and ease of application simultaneously with training protocols supports the feasibility of using tDCS in double-blind, sham-controlled randomized trials in clinical Neurorehabilitation.


CONCLUSIONS
tDCS could evolve into a useful tool, in addition to TMS, to modulate cortical activity in Neurorehabilitation.
Gandiga
Prateek C
PC
Human Cortical Physiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
Hummel
Friedhelm C
FC
Cohen
Leonardo G
LG
D000368:Aged; D016477:Artifacts; D001288:Attention / Q000502:physiology; D002986:Clinical Trials as Topic / Q000379:methods / Q000592:standards; D003463:Cues; D004311:Double-Blind Method; D004599:Electric Stimulation Therapy / Q000009:adverse effects* / Q000379:methods* / Q000639:trends; D005221:Fatigue / Q000209:etiology / Q000503:physiopathology; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology; D010292:Paresthesia / Q000209:etiology / Q000503:physiopathology; D012678:Sensation Disorders / Q000209:etiology / Q000503:physiopathology; D000071939:Stroke Rehabilitation; D016896:Treatment Outcome