tDCS and Speech Therapy in Aphasia Treatment: A Multicenter Comparative Study of Efficacy

BACKGROUND Aphasia is a common consequence of stroke and traumatic brain injury (TBI) that significantly impairs communication and quality of life. Transcranial direct current stimulation (tDCS) has emerged as a non-invasive technique potentially enhancing language rehabilitation. This study aimed to evaluate the efficacy of tDCS in combination with speech-language therapy (SLT) in improving language functions in patients with aphasia. MATERIAL AND METHODS A group of 90 patients diagnosed with TBI- or stroke-related aphasia were randomly assigned to 3 groups: tDCS alone (Group I), SLT alone (Group II), and tDCS combined with SLT (Group III). Treatment procedures spanned 5 months. tDCS sessions lasted 30-40 minutes each (1-1.5 mA), targeting the left dorsolateral (F3) and the right (F4) prefrontal cortex. Language function was assessed using the Frenchay Aphasia Screening Test (FAST), Aphasia Evaluation Scale (SODA), and Token Test (TT). Statistical analyses compared pre- and post-intervention outcomes within and between groups. RESULTS All groups demonstrated significant improvements in language function (p < 0.001). Group III showed the greatest gains in verbal expression, comprehension, and reading (32.6% improvement in FAST scores), significantly outperforming Group I (24.3%) and Group II (17.8%). tDCS alone was more effective than SLT alone (p = 0.04). Combining tDCS with SLT resulted in superior patient-reported improvements in daily communication and confidence in verbal expression compared to either treatment alone. CONCLUSIONS Patients who received combined tDCS and SLT had notable improvements across all measured parameters, including verbal expression, comprehension, reading, and writing, as assessed by the FAST, SODA, and TT tests.