Introduction: Non-invasive brain stimulation (NIBS) with speech therapy might improve recovery from post-stroke aphasia. This three-armed sham-controlled blinded prospective proof-of-concept study tested 1Hz subthreshold repetitive transcranial magnetic stimulation (rTMS) and 2-mA cathodal transcranial direct current stimulation (ctDCS) on the right pars triangularis in subacute post-stroke aphasia.

Patients and methods: Sixty-three patients with left middle cerebral artery infarcts were recruited in five hospitals (Canada/United States/Germany, 01–2014/03–2018) and randomized to receive rTMS (N=20), ctDCS (N=24) or sham stimulation (N=19) with ST for 10 days. Primary outcome variables were Z-score changes in naming, semantic fluency and comprehension tests and adverse event frequency. Secondary outcome variable was the percent change in the Unified Aphasia Score. Intention-to-treat analyses tested between-group effects at days 1 and 30 post-treatment with a pre-planned subgroup analysis for lesion location (affecting Broca’s area or not).

Results: Naming was significantly improved by rTMS (median=1.91/interquartile range=0.77/p=.01) at 30 days versus ctDCS (median=1.11/interquartile range¼1.51) and sham stimulation (median=1.02/interquartile range=1.71). All other primary results were non-significant. The rTMS effect was driven by the patient subgroup with intact Broca’s area where NIBS tended to improve UnAS (median=33.2%/interquartile range=46.7%/p=.062) versus sham stimulation (median=12.5%/interquartile range=7.9%) at day 30. Conversely, in patients with infarcted Broca’s area, UnAS tended to improve more with sham stimulation (median=75.0%/interquartile range/86.9%/ p=.053) versus NIBS (median=12.7%/interquartile range=31.7).

Zumbansen, A., Black, S.E., Chen, J.L., Edwards, D.J., Hartmann, A.E., Heiss, W.D., Lanthier, S., Lesperance, P., Mochizuki, G., Paquette, C., Rochon, E.A., Rubi-Fessen, I., Valles, J., Kneifel, H., Wortmann-Jutt, S., & Thiel, A. (2020). Non-invasive brain stimulation as add-on therapy for subacute post-stroke aphasia: a randomized trial (NORTHSTAR). European Stroke Journal 0(0), 1-11. https://doi.org/10.1177/2396987320934935