Differential effects of high-frequency repetitive transcranial magnetic stimulation over the left and right...

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).

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.

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).

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.