A meta-analysis of the effects of repetitive transcranial magnetic stimulation on aphasia rehabilitation in stroke patients

Abstract

Background & Objective: Aphasia—acquired loss of the ability to understand or express language—is a common and debilitating neurological consequence of stroke. Evidence suggests that transcranial magnetic stimulation (TMS) can significantly improve language outcomes in patients with aphasia. Repetitive transcranial magnetic stimulation (rTMS) has been reported to improve naming in chronic stroke patients with nonfluent aphasia since 2005.

Methods: We conducted a systematic review and meta-analyses of TMS treatment studies in patients with aphasia. Eight electronic databases (PubMed, Medline, Embase, Scopus, ScienceDirect, Cochrane Central Register of Controlled Trials, Journals@ Ovid, and clinicaltrials.gov) were searched for articles. Relevant studies were further evaluated and studies that met inclusion criteria were reviewed. We included studies if were: randomized controlled blinded clinical trials, meta-analyses or crossover designs of rTMS alone or with speech therapy or any other therapy tested with rTMS. Standard mean difference (SMD) for changes in picture naming accuracy was estimated.

Results: The literature search yielded 423 studies. Fifty articles were further evaluated to be included. Eleven met all inclusion criteria and were chosen for review. Eleven eligible studies involving 301 stroke patients were identified in this meta-analysis. Further analyses demonstrated prominent effects for the naming subtest (SMD = 1.26, 95% CI = 0.80 to 1.71, P=0.01), with heterogeneity (I2 = 69.101%). The meta-analysis continued to show that there was a statistically significant effect of rTMS compared with sham rTMS on the severity of aphasia. None of the patients from the 11 included articles reported adverse effects from rTMS.

Conclusions: There are some strong studies evaluating the efficacy of rTMS in stroke patients but further research is required to fully establish the usefulness of this treatment. This meta-analysis indicates a clinically positive effect of rTMS with or without speech and language therapy (SLT) for patients with aphasia following stroke in overall language function and expressive language, including naming, repetition, writing, and comprehension. Low-frequency (1 Hz) rTMS over the unaffected hemisphere is effective and compatible with the concept of interhemispheric inhibition. Moreover, the treatment of 1 Hz rTMS for patients with aphasia after stroke was safe.