Efficacy of tDCS in Post-Stroke Aphasia Recovery.

Abstract

Post-stroke aphasia, characterized by varying language deficits, typically arises following left-brain damage. Although speech-language therapy (SLT) is an effective treatment, it often fails to fully restore language functionality, underscoring the urgent need for innovative interventions. Transcranial direct current stimulation (tDCS) emerges as a promising, safe, and feasible strategy that can be smoothly integrated into SLT routines. By modulating brain activity and fostering plastic changes, tDCS is particularly effective when paired with SLT, as this combination promotes experience-dependent plasticity in relevant networks. This strategy has shown considerable efficacy in enhancing the benefits of naming therapy, a primary focus area in aphasia literature. Despite fewer studies investigating other language domains, encouraging outcomes have been observed across virtually all language areas. However, larger and more rigorously controlled trials are essential to substantiate these findings. Significant variations in study designs, including stimulation parameters such as intensity, site, and duration, must also be addressed. Furthermore, individual factors like lesion location, size, and time post-stroke must be considered for more precise and personalized results. While anodal tDCS over the left hemisphere has received substantial support, there is an apparent need for individualized current flow modeling to ensure accurate stimulation sites. Increased research into high-definition tDCS is advocated to facilitate more focused stimulation and reduce inter-individual variability in current flow. As research advances, rigorously designed large-scale trials are critically needed to bridge existing knowledge gaps and fully harness the therapeutic potential of this innovative technology.