Pre-Frontal tDCS as a novel intervention to reduce effects of post-stroke fatigue while improving language and attention in aphasia - PROJECT SUMMARY Fatigue is highly prevalent in the stroke population, and it is often reported as one of the most debilitating post- stroke symptoms. Unfortunately, post-stroke fatigue is not effectively managed, primarily because little evidence exists supporting post-stroke fatigue treatment. Transcranial direct current stimulation (tDCS) is a type of neuromodulation that has been shown to improve treatment response in persons with aphasia (PWA) and is a promising treatment approach for reducing post-stroke fatigue. Considering the potential impact of fatigue on aphasia recovery, there is an urgent and critical need to assess interventions that can alleviate the consequences of post-stroke fatigue, boost cognition and language, and maximize the brain’s neuroplasticity. Studies have shown that tDCS applied to dorsolateral prefrontal cortex (DLPFC) can improve attention and language comprehension after stroke. However, it remains unknown if tDCS administered to DLPFC can simultaneously enhance attention task performance, improve language comprehension, and reduce post-stroke fatigue. The long-term goal of this research is to increase the effectiveness of speech and language treatments for aphasia by accounting for individual and cognitive factors that could negatively affect recovery. This project will advance the NIDCD’s mission by directly addressing one of these factors to improve stroke and aphasia rehabilitation. The proposed project is a critical step towards advancing the clinical science of aphasia treatment through two specific aims: 1) to conduct a rigorous clinical trial implementing neuromodulation in combination with behavioral attention-focused language treatment to improve attention, language, and fatigue outcomes for PWA, and 2) to comprehensively identify mechanistic interrelationships among post-stroke fatigue, cognitive deficits, and language deficits in PWA. Using a 2x2 factorial design, participants will first be randomized to tDCS condition (active or sham) and then randomized to a behavioral sentence comprehension condition (+attention or - attention). Participants will undergo 10 sessions of treatment and outcome measures will be administered at 3 time points (baseline, post-training, 3-month follow-up). Attention performance will be measured using sustained, alerting, orienting, and executive attention tasks. Sentence comprehension will be measured using a treatment- based and a functional sentence comprehension task. Fatigue will be measured using an aphasia-adapted version of the Fatigue Severity Scale, a commonly used fatigue measurement tool. We will address our study aims by comparing performance on these tasks across all combinations of treatment (+/- tDCS; +/- attention- focused language treatment). At the conclusion of this clinical trial, we expect to provide evidence that active anodal tDCS to DLPFC in combination with behavioral attention-focused language treatment can enhance attention ability, improve sentence comprehension, and reduce post-stroke fatigue. We also expect to show that language and attention deficits are associated with clinically significant fatigue and that clinically significant fatigue is associated with poorer treatment outcomes.
