The Effectiveness and Safety of Noninvasive Brain Stimulation Technology Combined With Speech Training on Aphasia After Stroke: A Systematic Review and Meta-Analysis

Medicine

Han, C., Tang, J., et al. (2024).

Medicine, 103(2), e36880.

This systematic review and meta-analysis investigate the effects and safety of combining non-invasive brain stimulation (NIBS) with speech therapy compared to speech therapy alone (i.e., speech therapy with sham stimulation) and its impact on speech and language outcomes for individuals with post-stroke aphasia. In addition to a traditional meta-analysis, a network meta-analysis was completed to rank the effects of different NIBS technologies on improving aphasia severity.

Not stated

From database inception to August 25, 2023

Randomized-controlled trials

17

<div>Combining NIBS with speech therapy resulted in significantly improved aphasia severity, language performance and clinical efficiency (p &lt; .05) when compared to speech therapy alone. Pooled effect sizes on the Western Aphasia Battery (WAB) and clinical effectiveness rate were as follows:</div> <ul> <li><span style="color: #333333;">WAB Aphasia Quotient (AQ) score: standardized mean difference (SMD) = 1.06,&nbsp;</span></li> <li><span style="color: #333333;">WAB Spontaneous Language: SMD = 0.62,&nbsp;</span></li> <li><span style="color: #333333;">WAB Repetition: SMD = 1.14, </span></li> <li><span style="color: #333333;">WAB Naming: SMD = 1.06, and </span></li> <li><span style="color: #333333;">Clinical effectiveness rate: Odds ratio = 4.19. </span></li> </ul> <div><span style="color: #333333;"><span style="color: #333333;">Further analysis showed similar findings when results were examined by technology type. Pooled effects for repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) were as follows:</span></span></div> <ul> <li><span style="color: #333333;">rTMS plus speech therapy: WAB AQ SMD = 1.24; WAB Repetition SMD = 0.67; WAB Naming SMD = 1.06, and</span></li> <li><span style="color: #333333;">tDCS plus speech therapy: WAB AQ SMD = 0.71; WAB Repetition SMD = 2.69; WAB Naming SMD = 1.13.</span></li> </ul> <div><span style="color: #333333;"><span style="color: #333333;">A network meta-analysis examining aphasia severity revealed a probability ranking for improving WAB AQ scores by technology type. The rTMS group had a probability ranking of 92.2% and the tDCS group had a probability of 55.7%. However, only the AQ scores of the rTMS plus speech therapy group were higher than the speech only group. <br><br>While NIBS as an adjunct to speech treatment appeared to have beneficial effects on language outcomes, more research is necessary due to the limited number of studies included, small sample sizes, and methodological limitations.</span><br></span></div>

<div>Overall, there were no significant adverse reactions observed with the combination of NIBS and speech therapy. Out of eight studies, six reported no adverse reactions during treatment, while two studies noted mild side effects like dizziness, headache, and paresthesia. All adverse events resolved on their own.</div>