TDCS-enhanced training in chronic post-stroke aphasia

• Applicant: Professorin Dr. Agnes Flöel
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology
• Term: since 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 371431740

Intensive speech-language therapy (SLT) can promote recovery from chronic post-stroke aphasia, a major consequence of stroke. However, effect sizes of intensive SLT are moderate, potentially reflecting a physiological limit of training-induced progress. Transcranial direct current stimulation (tDCS) is an easy-to-use, well-tolerated and low-cost approach that may enhance effectiveness of intensive SLT. In a former phase-II randomized controlled trial, 26 individuals with chronic post-stroke aphasia received intensive SLT combined with anodal-tDCS of the left primary motor cortex (M1), resulting in improved naming and proxy-rated communication ability, with medium-to-large effect sizes. Since 2019, the present study „DC_TRAIN_APHASIA“ seeks to establish the incremental benefit from anodal-tDCS of M1 in a phase-III randomized controlled trial with adequate power, ecologically valid outcomes, and evidence-based SLT. The study is a prospective randomized placebo-controlled (using sham-tDCS), parallel-group, double-blind, multi-center, phase-III superiority trial. A sample of 140 individuals with aphasia at least 6 months post-stroke has been recruited in 19 in- and outpatient rehabilitation centers. The primary outcome focuses on communication ability in chronic post-stroke aphasia, as revealed by changes on the Amsterdam-Nijmegen Everyday Language Test (A-scale; primary endpoint: 6-month follow-up; secondary endpoints: immediately after treatment, and 12-month follow-up). Secondary outcomes include measures assessing linguistic-executive skills, attention, memory, emotional well-being, quality of life, health economic costs, and adverse events (endpoints: 6-month follow-up, immediately after treatment, and 12-month follow-up). Follow-up assessments will be conducted until February 2026 (last patient out); followed by database closure, statistical analyses, and publication of the results. Positive results will increase the quality of life for persons with aphasia and their families while reducing societal costs. Communication of results with relevant stakeholders will ensure transfer into best-practice guidelines and successful integration within clinical routine.

• DFG Programme: Clinical Trials
• Co-Investigators: Professorin Dr. Tanja Grewe; Professor Dr. Marcus Meinzer; Professor Dr. Benjamin Stahl