Differential effects of high-frequency repetitive transcranial magnetic stimulation over the left and right dorsolateral prefrontal cortex for post-stroke cognitive impairment.

Objective: In this study, it is aimed to explore the different effects of repetitive transcranial magnetic stimulation (HF-rTMS)over the left and right dorsolateral prefrontal cortex (DLPFC) for post-stroke cognitive impairment (PSCI).

Method: In this study, we allocated 40 patients with PSCI who were divided into the left DLPFC group (n = 20) and the right DLPFC group (n = 20). Patients received 20HZ rTMS over the ipsilateral DLPFC respectively, for 20 consecutive days (20 min/time, 1 time/day). Cognitive performance was assessed before and after treatment using the Montreal Cognitive Assessment (MoCA), the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA), and the Modified Barthel Index (MBI). Furthermore, event-related potential (ERP) detection was also conducted in patients at baseline and after treatment.

Results: After treatment, the global cognition, orientation, and language of patients in the left DLPFC group were significantly improved (P < 0.05). While the enhancement of visual perception and spatial perception in the right DLPFC group was significant (P < 0.05). MBI scores in both groups were increased (P < 0.05), but there was no significant difference between the two groups after treatment (P > 0.05).The decrease of latency in the left DLPFC group was more significant than that in the right DLPFC group (P < 0.05), but there was no significant difference in amplitude (P > 0.05).

Conclusion: The results support that high-frequency rTMS over the left DLPFC is a more effective treatment for improving global cognition and suggest that the left and right DLPFC are associated with different cognitive functions.