Is transcranial magnetic stimulation an effective therapy for aphasia?

Wolf-Dieter Heiss and Alexander Thiel

Functional imaging studies suggest that recruitment of contralesional areas hinders optimal functional cortical reorganization in patients with post-stroke aphasia. In this review, imaging data of activation shifts in the course of poststroke aphasia are described and data on transcallosal disinhibition of right-hemispheric homolog speech areas are presented. The activated right-hemispheric regions are the target for inhibitory repetitive transcranial magnetic stimulation (rTMS) as a treatment option for aphasia. Several cases and one small controlled study have reported improved function after rTMS treatment in chronic aphasics. In one controlled feasibility study, rTMS over the right homolog of Broca’s area was compared with sham stimulation over the vertex in the subacute stage and demonstrated a reduction of the activation shift to the right hemisphere in the treated group, which was related to a significantly improved outcome in the Aachen Aphasia Test. The clinical application of rTMS as a supportive treatment for poststroke aphasia requires further proof of efficacy in a large multicenter trial.