Exploring the mechanism of transcranial direct current stimulation combined with aerobic exercise in improving...

Post-stroke cognitive impairment (PSCI) often involves working memory deficits. This study explored whether combining transcranial direct current stimulation (tDCS) and aerobic exercise (AE) improves working memory in PSCI patients and investigated the underlying neurophysiological mechanisms using event-related potentials (ERPs).

A total of 60 PSCI patients were randomly assigned to three groups: tDCS (2.0 mA anodal stimulation over left dorsolateral prefrontal cortex, 30 min/day, 5 days/week for 4 weeks), AE (moderate-intensity, 60-70 % maximum heart rate, 30 min/day with sham tDCS), and combined (tDCS + AE). Working memory was assessed via 1-back task before and after intervention. ERPs (N200, P300) were recorded during the task. Repeated measures analysis of variance and Bonferroni correction were used for statistical analysis (p < 0.05).

No significant differences in 1-back accuracy were observed among groups post-intervention. For ERPs: N200 amplitude in the combined group was larger than the AE group at Fz/Cz (both conditions) and larger than the tDCS group at Cz (hit condition). P300 amplitude in the combined group showed mixed patterns, with significant differences versus tDCS and AE groups across Fz, Cz, and Pz points under hit and correct rejection conditions.

Combining tDCS and AE did not enhance 1-back task performance but modulated N200 and P300, suggesting benefits for early-stage conflict monitoring and sequence mismatch recognition in working memory, supporting a potential multimodal rehabilitation strategy for PSCI.

This study was approved by the hospital's Ethics Committee (Approval No. WXMHCIRB2021LLky145) and conducted in accordance with the Declaration of Helsinki. The trial was registered with the Chinese Clinical Trial Registry (ChiCTR2100052745). All patients provided written informed consent prior to randomization.