tDCS and Speech Therapy to Improve Aphasia

To study the effect of combined tDCS plus speech therapy compared to sham-tDCS plus speech therapy in subacute stroke patients suffering from moderate or severe aphasia. The patients will be randomized by a computer-generated lot. Assessment will be performed at study onset, after six weeks at the end of the specific intervention and 4 months after stroke onset for follow-up.

Approximately 25% of all patients after stroke suffer from aphasia. The aphasia could be so severe, that the patient cannot produce any words at all, and so the communication ability is rather poor. In that case speech therapy is the most common therapy, but the functional outcome for the patient is often not sufficiently. The transcranial direct current stimulation (tDCS) might improve the outcome of speech therapy in patients with severe aphasia. The patients will be randomized either to verum stimulation (group A) or sham stimulation (group B). In group A they will receive every workday for 6 weeks 20min of tDCS with 2 mA in combination with a 30 min speech therapy. In group B they will receive every workday for 6 weeks 20min of tDCS with 0 mA in combination with a 30 min speech therapy. The anodal electrode will be placed in case of a total anterior circulation stroke on the homologous speech area on the right hemisphere and in case of a partial anterior circulation stroke perilesional on the left hemisphere. The cathode will be positioned contralateral.