Further Evidence of the Positive Influence of Repetitive Transcranial Magnetic Stimulation on Speech and Language in Patients with Aphasia after Stroke: Results from a Double-Blind Intervention with Sham Condition

Abstract

Background: After a stroke, up to 20% of patients suffer from aphasia. The preferred treatment for stroke-related aphasia (SRA) is regular speech and language training (SLT). In the present study, we investigated to what extent adjuvant repetitive transcranial magnetic stimulation (rTMS) might enhance recovery. While there is growing evidence of the positive effect of adjuvant rTMS on aphasia, no study has yet been based on an Iranian sample. Method: A total of 12 patients (mean age: 55 years; right-handed; 7 women) underwent treatment for SRA 1 month after stroke. The standard treatment consisted of regular 45-min SLT sessions 5 times a week for 2 consecutive weeks. Additionally, patients were randomly assigned either to adjuvant rTMS (5 times a week for 30 min) or to a sham condition (5 times a week for 30 min). At baseline and after 2 weeks of intervention, the degree of aphasia was assessed with the Farsi version of the Western Aphasia Battery. rTMS was applied to the inferior posterior frontal gyrus of the right hemisphere. Results: Speech and language improved over time, but more so in the rTMS than in the sham condition. Large effect sizes were observed for content, fluency, and the aphasia quotient; medium effect sizes were observed for command comprehension and repetition, while effect sizes were small for auditory comprehension and naming. Conclusions: Among patients with SRA, compared to a sham condition, adjuvant rTMS improved speech and language skills. The present results add to the accumulating evidence that rTMS as a neuromodulation technique has the capacity to enhance the effect of conventional SLT.

Current Approaches to the Treatment of Post-Stroke Aphasia

“…The authors reported a significant time by group interaction but no P-values or CIs were reported. 145 A larger cross-over study (n=30) of low frequency rTMS (vs. sham) to the right IFG, each with subsequent 45 minutes of language therapy for 10 sessions, also showed greater improvement with rTMS compared to sham on object naming (47.4±28.3 vs. 35.3±30.1, P<0.05), object naming reaction time (12.1±4.9 vs. 13.9±5.1, P<0.01), action naming (34.8±24.6 vs. 25.9±20.4, P<0.01), and action naming reaction time (15.4±5.2 vs. 15.4±5.7, P<0.01) immediately after therapy, and lasting up to 3 months, and showed gains in functional communication. 146 Similar effects of both low and high frequency rTMS have been reported in studies of chronic post-stroke aphasia (see a Naeser et al 137 for review and Ren et al 147 for a meta-analysis).…”

From Broca and Wernicke to the Neuromodulation Era: Insights of Brain Language Networks for Neurorehabilitation

“…This effect can be visualized by neuroimaging [57]. Targeting these areas (and more specifically the triangular part of the right inferior frontal gyrus (IFG)) with low-frequency, inhibitory rTMS has a positive effect on language recovery in patients with aphasia following stroke [58, 59]. An important point for rTMS application is the need to stimulate the same cortical area, and this can be achieved by using brain MRI data of the treated individual to calculate the correct positioning of the coil with new generation rTMS devices by utilizing neuronavigation techniques.…”

Functional Magnetic Resonance Imaging of Language Following Constraint-Induced Aphasia Therapy Primed with Intermittent Theta Burst Stimulation in 13 Patients with Post-Stroke Aphasia

“…Studies have indicated that non-invasive brain stimulation such as repetitive transcranial magnetic stimulation (rTMS) may promote more effective language recovery after stroke [ 3 – 6 ]. One prevailing concept is that diminished transcallosal inhibition of the non-dominant right hemisphere following left middle cerebral artery stroke negatively affects the potential of left-hemispheric dominant language centers to recover function [ 7 , 8 ].…”

“…The addition of non-invasive brain stimulation to the treatment arsenal for post-stroke aphasia may help boost treatment effects of language therapy by taking advantage of the neuromodulatory effects of rTMS. Studies combining language therapy with rTMS have shown positive results in improving language function in post-stroke aphasia [ 3 , 6 , 19 – 22 ]. As stated above, the majority of these studies administered inhibitory low-frequency rTMS to the unaffected right hemisphere and found language improvements, particularly with naming [ 23 – 26 ].…”