Affiliations: Department of Rehabilitation Medicine, Seoul National
University Bundang Hospital, Seongnam, South Korea | Clinical Neuroscience Center, Seoul National
University Bundang Hospital, Seongnam, South Korea | Department of Neurology, Seoul National University
College of Medicine, Seoul, South Korea | 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 300 Gumi-dong, 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: Attention decline after stroke is common and hampers the
rehabilitation process, and non-invasive transcranial direct current
stimulation (tDCS) has the potential to elicit behavioral changes by modulating
cortical excitability. The authors tested the hypothesis that a single session
of non-invasive cortical stimulation with excitatory anodal tDCS applied to the
left dorsolateral prefrontal cortex (DLPFC) can improve attention in stroke
patients. Methods: Ten patients with post-stroke cognitive decline (MMSE ⩽
25) and 10 age-matched healthy controls participated in this double blind,
sham-controlled, crossover study involving the administration of real (2 mA for
20 min) or sham stimulation (2 mA for 1 min) to the left DLPFC. Attention was
measured using a computerized Go/No-Go test before and after intervention.
Improvements in accuracy and speed after stimulation relative to baseline were
compared for real and sham stimulations. Results: In healthy controls, no significant improvement in Go/No-Go
test was observed after either real or sham stimulation. However, in stroke
patients, tDCS led to a significant improvement in response accuracy at 1 hour
post-stimulation relative to baseline, and this improvement was maintained
until 3 hours post-stimulation (P< 0.05), whereas sham stimulation did not
lead to a significant improvement in response accuracy (P> 0.05). Changes in
reaction times were comparable for the two stimulations (P> 0.05). Conclusion: Non invasive anodal tDCS applied to the left DLPFC was
found to improve attention versus sham stimulation in stroke patients, which
suggests that non-invasive cortical intervention could potentially be used
during rehabilitative training to improve attention.
