Effects of dual transcranial direct current stimulation for aphasia in chronic stroke patients.
OBJECTIVE
To investigate any additional effect of dual transcranial direct current stimulation (tDCS) compared with single tDCS in chronic stroke patients with aphasia.


METHODS
Eleven chronic stroke patients (aged 52.6±13.4 years, nine men) with aphasia were enrolled. Single anodal tDCS was applied over the left inferior frontal gyrus (IFG) and a cathodal electrode was placed over the left buccinator muscle. Dual tDCS was applied as follows: 1) anodal tDCS over the left IFG and cathodal tDCS over the left buccinator muscle and 2) cathodal tDCS over the right IFG and anodal tDCS over the right buccinator muscle. Each tDCS was delivered for 30 minutes at a 2-mA intensity. Speech therapy was provided during the last 15 minutes of the tDCS. Before and after the stimulation, the Korean-Boston Naming Test and a verbal fluency test were performed.


RESULTS
The dual tDCS produced a significant improvement in the response time for the Korean-Boston Naming Test compared with the baseline assessment, with a significant interaction between the time and type of interventions. Both single and dual tDCS produced a significant improvement in the number of correct responses after stimulation with no significant interaction. No significant changes in the verbal fluency test were observed after single or dual tDCS.


CONCLUSIONS
The results conveyed that dual tDCS using anodal tDCS over the left IFG and cathodal tDCS over the right IFG may be more effective than a single anodal tDCS over the left IFG.
Department of Physical and Rehabilitation Medicine, Stroke and Cerebrovascular Center, Samsung Medical Center, Seoul, Korea.
Seung Yeol
SY
Lee
Hee-Jung
HJ
Cheon
Kyoung Jae
KJ
Yoon
Won Hyuk
WH
Chang
Yun-Hee
YH
Kim
Aphasia; Electrical stimulation therapy; Stroke; Transcranial direct current stimulation