Modulating language and executive functions in bilingual aphasia with cerebellar tDCS: a case series

This case series explores the effects of cerebellar transcranial direct current stimulation (tDCS) on language and executive functions in bilinguals with aphasia. We present seven Dutch-French bilingual participants diagnosed with Primary Progressive Aphasia (PPA) or post-stroke aphasia, including one non-fluent variant PPA (nfvPPA), three logopenic variant PPA (lvPPA), one semantic variant PPA (svPPA), and two post-stroke non-fluent aphasia patients. 20 min of 2 mA anodal tDCS to the right posterolateral cerebellum was combined with speech and language therapy. We administered subtests of the Bilingual Aphasia Test, Boston Naming Test, Stroop, and Attention Network Tests. Cerebellar tDCS compared to sham led to greater enhancement of language recovery in both languages, and inhibitory control, providing evidence for the cerebellum's role in both language and executive processes. Our findings contribute to a deeper understanding of cerebellar stimulation as a therapeutic tool in bilingual aphasia, with implications for future research and clinical interventions.