Transcranial Magnetic Stimulation for the Rehabilitation of Broca's Aphasia: A Review of Current Protocols and Clinical Outcomes

Abstract

Stroke constitutes a leading global cause of long-term disability, leaving a significant percentage of survivors with persistent neurological deficits that compromise their independence and quality of life. Post-stroke Broca's aphasia represents a significant source of chronic disability, with many individuals reaching a plateau in recovery despite conventional speech and language therapy. Non-invasive brain stimulation, particularly repetitive Transcranial Magnetic Stimulation (rTMS), has emerged as a promising adjunctive therapy to enhance neuroplasticity and improve language outcomes. The objective of this review is to critically evaluate the evidence from peer-reviewed studies investigating these TMS protocols, with a specific focus on their methodological parameters, documented clinical efficacy, safety profiles, and overall contribution to the treatment of post-stroke Broca's aphasia. This review synthesises the peer-reviewed literature on the use of rTMS for Broca's aphasia, examining the underlying neurophysiological models, dominant treatment protocols, and clinical findings. Evidence largely supports two main paradigms: an inhibitory protocol applied to the contralesional (right) hemisphere to reduce interhemispheric inhibition, and an excitatory protocol applied to the ipsilesional (left) hemisphere to directly boost activity in surviving language networks. While multiple studies, including randomised controlled trials, demonstrate significant improvements in naming and overall language function, outcomes are variable, and some large trials have yielded null primary findings. The data suggest that TMS is a safe intervention, but its efficacy is influenced by factors such as patient chronicity, lesion characteristics, and the specific protocol employed. Future research must focus on personalising treatment to optimise this promising therapeutic tool. In its entirety, the current research landscape provides a solid foundation and a clear mandate: the era of generalised TMS application is ending, and the era of personalised, biomarker-guided neuromodulation for aphasia must now begin.