Neuromodulation of Executive Dysfunction in Patients with Acute Stroke Using Transcranial Direct Current Stimulation: Study Protocol for a Triple-Blind, Randomized Sham-Controlled Trial

Abstract

Research on the benefits of non-invasive brain stimulation in stroke patients to improve executive functions is scarce. The objective of this study is to investigate the effectiveness of transcranial direct current stimulation (tDCS) in combination with cognitive training for the rehabilitation of executive functions in acute and subacute stroke patients as well as to explore the underlying physiological mechanisms. A triple-blinded, randomized-controlled clinical trial will be conducted involving 60 stroke patients with frontal or basal ganglia lesions and a Montreal cognitive assessment (MoCA) score less than 26. Participants will be randomly assigned to receive active tDCS (anode over the left dorsolateral prefrontal cortex, cathode at the right supraorbital region, 20 minutes at 2 mA) or sham tDCS in a 1:1 ratio for 10 sessions, followed by targeted executive function training. The primary efficacy outcome will be the MoCA score, while secondary outcomes will include the Five-digit test (inhibitory control), the Digit span task (working memory), the abbreviated version of the Wisconsin Card Sorting test (cognitive flexibility), rankin modified scale (functional state), Beck-II depression inventory, apathy evaluation scale and the WHOQOL-BREF (quality of life), assessed immediately after the intervention and at one, three, six, and twelve months post-intervention. Additionally, resting-state functional connectivity and blood biomarkers, such as neurotrophins, growth factors, and inflammatory molecules, will be evaluated before and after the intervention. This study will contribute to the investigation of the efficacy of tDCS in rehabilitating executive functions in acute and subacute stroke patients. The multidimensional approach utilized in this study, which includes analysis of resting-state connectivity and neuroplasticity-related blood biomarkers, is expected to provide insights into the underlying brain mechanisms involved in the rehabilitation of dysexecutive syndrome.