Slide Slam J1 Sandbox Series
Effectiveness of rTMS in treating post-stroke aphasia: Role of stimulation parameters and individual characteristics
Aneta Kielar1, Dianne Patterson1, Amelia Guzik1, Ying-Hui Chou1; 1University of Arizona
Introduction: One of the most deliberating and difficult to treat symptoms of stroke is aphasia. Aphasia is incapacitating because it can affect all aspects of language, including speech production, comprehension, reading and writing. In the recent years noninvasive neuromodulation technique, repetitive transcranial magnetic stimulation (rTMS) has been explored as a potential adjunctive treatment for aphasia. Although the results are encouraging the effectiveness of rTMS in treating post-stroke language deficits varies. These inconsistencies are due to the variations in the stimulation protocols, rTMS parameters and patient characteristics across the different studies. The purpose of this meta-analysis was to examine effectiveness of rTMS in treating post-stroke aphasia and to identify parameters that are associated with the best treatment outcome. Methods: This systematic review and meta-analysis was conducted and reported according to the guidance of the preferred reporting for systematic reviews and meta-analyses (PRISMA) statement (Moher et al., 2009). The protocol CRD42020180104 is available in full on the PROSPERO program website (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020180104). Results: A total of 24 studies (out of 1971 records) with 567 participants (Mean age = 60.4 years, SD = 5.46, Mean Education = 13 years, SD = .97; 65% Males) meet selection criteria and were included in the meta-analysis. The overall pooled analysis revealed significant SMD of 0.655 (95% CI = [0.481-0.830], z = 7.369, p < .001), indicating medium effect size in favor of rTMS treatment. A moderator subgroup analyses were performed to investigate effects of different patients’ characteristics and rTMS parameters on treatment outcomes. The results indicated that stroke chronicity, symptoms severity, speech fluency, and lesion location moderated effect of rTMS on language performance. Although, rTMS improved language abilities in both chronic and subacute aphasia, the effects were the strongest in the subacute stages after the stroke. The examination of rTMS parameters indicated that low frequency stimulation to the right IFG (BA45) had most beneficial effect on language abilities. rTMS alone and rTMS augmented with SLT were both effective in enhancing language ability. The examination of language outcomes, indicated that 1 Hz rTMS applied to the right IFG (BA45) had most beneficial effect on naming ability, followed by speech production, repetition and comprehension. Interestingly, the beneficial effect of rTMS on language performance increased at moderate and long-term follow-ups. The results suggest that with 10 to 15 sessions of 1Hz rTMS administered 20-40 min per day over the right IFG, significant language improvements can be observed for up to 12 months. The studies that used fMRI to track effects of rTMS reported significant correlation between shift to the left hemisphere activation and reduced aphasia severity after the intervention with rTMS. Conclusions: The results of our meta-analysis indicate that rTMS alone and combined with the speech-language therapy can be effective in treating language deficit in post-stroke aphasia. Our findings suggest that when planning interventions, it is important to consider the relationship between specific rTMS protocol parameters and individual patient’s demographic and clinical characteristics, as well as language outcomes targeted with the treatment.