Affiliations: Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea | Department of Rehabilitation Medicine, Seoul Bukbu Geriatric Hospital, Seoul, South Korea | Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea | Human Cortical Physiology Section and Stroke Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA | Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul, South Korea
Note: [] Corresponding author: Nam-Jong Paik, MD, PhD, Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 166 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea. Tel.: +82 31 787 7731; Fax: +82 31 712 3913; E-mail: njpaik@snu.ac.kr
Abstract: Purpose: Previous reports have suggested that noninvasive cortical stimulation could influence speech production in patients with chronic stroke. Here, we evaluated the hypothesis that cathodal transcranial DC stimulation (ctDCS), a technique that decreases excitability of stimulated cortical sites, applied over a healthy right Broca's homologue area could improve picture naming in patients with post-stroke aphasia. Methods: Ten right-handed patients with post-stroke aphasia were enrolled in this double blind, counterbalanced sham-controlled, crossover study. Each patient received an intervention of ctDCS (2 mA for 20 min) and of sham tDCS (2 mA for 1 min) daily for 5 consecutive days in a randomized crossover manner with a minimum interval of one week between interventions, over a healthy right Broca's homologue area using a left supraorbital anode and simultaneous daily sessions of conventional word-retrieval training. The primary endpoint measure of this study was a standardized, validated Korean version of the Boston Naming Test, which is a measure of picture naming skills. Results: ctDCS was not found to have any adverse effects. Furthermore, significantly improved picture naming (p = 0.02) was observed at 1 hour following the last (5th) ctDCS treatment session, but no changes were observed after sham tDCS. Conclusion: These results demonstrate that cathodal tDCS over the right healthy Broca's homologue area with a left supraorbital anodal location can improve picture naming task performance in post-stroke aphasia.
Keywords: Aphasia, stroke, cortical stimulation, transcranial direct current stimulation
