Transcranial Direct Current Stimulation Improves Naming Reaction Time in Fluent Aphasia: A Double-Blind, Sham-Controlled Study

• Published in: Stroke (1970) 2011-03, Vol.42 (3), p.819-821
• Main Authors: FRIDRIKSSON, Julius, RICHARDSON, Jessica D, BAKER, Julie M, RORDEN, Chris
• Format: Article
• Language: English
• Subjects: Aged; Aphasia, Wernicke - etiology; Aphasia, Wernicke - physiopathology; Aphasia, Wernicke - therapy; Biological and medical sciences; Double-Blind Method; Electric Stimulation Therapy - methods; Female; Humans; Language Tests; Male; Medical sciences; Middle Aged; Muscle; Neurology; Pharmacology. Drug treatments; Reaction Time - physiology; Stroke - complications; Stroke - physiopathology; Stroke - therapy; Vascular diseases and vascular malformations of the nervous system
• ISSN: 0039-2499; 1524-4628; 1524-4628
• DOI: 10.1161/STROKEAHA.110.600288

Previous evidence suggests that anodal transcranial direct current stimulation (A-tDCS) applied to the left hemisphere can improve aphasic participants' ability to name common objects. The current study further examined this issue in a more tightly controlled experiment in participants with fluent aphasia. We examined the effect of A-tDCS on reaction time during overt picture naming in 8 chronic stroke participants. Anode electrode placement targeted perilesional brain regions that showed the greatest activation on a pretreatment functional MRI scan administered during overt picture naming with the reference cathode electrode placed on the contralateral forehead. A-tDCS (1 mA; 20-minute) was compared with sham tDCS (S-tDCS) in a crossover design. Participants received 10 sessions of computerized anomia treatment; 5 sessions included A-tDCS and 5 included S-tDCS. Coupling A-tDCS with behavioral language treatment reduced reaction time during naming of trained items immediately posttreatment (Z=1.96, P=0.025) and at subsequent testing 3 weeks later (Z=2.52, P=0.006). A-tDCS administered during language treatment decreased processing time during picture naming by fluent aphasic participants. Additional studies combining A-tDCS, an inexpensive method with no reported serious side effects, with behavioral language therapy are recommended.