Changes of Cortical Excitability by Prefrontal tDCS in Patients with Stroke: A case report

ABSTRACT

In this case study with 2 chronic stroke patients, we investigated the nature of modulation of neural activities during the working memory (WM) task by transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) using functional MRI (fMRI). Two patients with chronic right hemispheric stroke participated. Patients performed the 2-back WM task within the fMRI scanner before and after tDCS application while the response data were recorded. An anodal tDCS of 1 mA over the left DLPFC was applied for 20 min within fMRI scanner. The accuracy and the recognition accuracy of WM task were improved after applying tDCS. In fMRI images, activation was decreased in the left superior temporal areas in both cases which represent increased efficiency of neural resources after applying the tDCS. The results of this study showed that the effective modulation of cortical activity by tDCS might be a determinant for behavioral changes of enhancing WM function in patients with stroke.