Kerstin Spielmann, W. Mieke E. van de Sandt-Koenderman, Majanka H. Heijenbrok-Kal, Gerard M. Ribbers
Rehabilitation medicine, Erasmus MC, University Medical Center Rotterdam, 3000 CA Rotterdam, The Netherlands
DOI: 10.2340/16501977-2338

Objective: To compare 2 configurations of transcranial direct current stimulation (tDCS) for treatment of aphasia.
Design: Randomized cross-over study.
Subjects: Patients with chronic post-stroke aphasia (n = 13).
Methods: tDCS was combined with word-finding therapy in 3 single sessions. In session 1, sham-tDCS/pseudo-stimulation was applied. In sessions 2 and 3, 2 active configurations were provided in random order: anodal tDCS over the left inferior frontal gyrus (l-IFG) and anodal tDCS over the left posterior superior temporal gyrus (l-STG). The optimal configuration was determined per individual based on a pre-set improvement in naming trained (> 20%) and untrained picture items (> 10%).
Results: Overall, participants improved on trained items (median = 50%; interquartile range = 20–85) and post-treatment performance was highest in the active l-IFG condition (p = 0. 040). Of the 13 participants, 6 (46%) showed relevant improvement during active tDCS; either in the l-IFG condition (n = 4; 31%) or in both the l-IFG and l-STG conditions (n = 2; 15%). On the untrained items there was no improvement (median = 0%; interquartile range  = 0–0).
Conclusion: This randomized cross-over single-session protocol to determine an optimal tDCS configuration for treatment of aphasia suggests that only performance on trained items can be used as guidance for configuration, and that it is relevant for half of the patients. For this subgroup, the l-IFG configuration is the optimal choice.

Brain-stimulation techniques are currently being studied as a new treatment for people with post-stroke aphasia. The best electrode placement for people with aphasia is a topic of discussion. This study describes a protocol to compare two electrode placements within 13 individuals with post-stroke aphasia and discusses how to choose the optimal electrode placement for each individual. We conclude that, for a sub-group of patients, it was possible to choose an optimal electrode placement. In future studies it will be important to study the effectiveness of a chosen electrode placement, which requires multiple treatment sessions with brain-stimulation.

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