Repetitive transcranial magnetic stimulation (rTMS) can influence the stimulated brain regions and other distal brain regions connecting to them. The purpose of the study is to investigate the effects of low-frequency rTMS over primary motor cortex on brain by analyzing the brain functional connectivity and coordination between brain regions. 10 healthy subjects were recruited. 1 Hz rTMS was used to stimulate primary motor cortex for 20 min. 1 min resting state electroencephalography (EEG) was collected before and after the stimulation respectively. By performing phase synchronization analysis between the EEG electrodes, the brain functional network and its properties were calculated. Signed-rank test was used for statistical analysis. The result demonstrated that the global phase synchronization in alpha frequency band was decreased significantly after low-frequency rTMS (P<0.05). The phase synchronization was down-regulated between motor cortex and ipsilateral frontal/parietal cortex, and also between contralateral parietal cortex and bilateral frontal cortex. The mean degree and global efficiency of brain functional networks in alpha frequency band were significantly decreased (P<0.05), and the mean shortest path length were significantly increased (P<0.05), which suggested the information transmission of the brain networks and its efficiency was reduced after low-frequency rTMS. This study verified the inhibition function of the low-frequency rTMS to brain activities, and demonstrated that low-frequency rTMS stimulation could affect both stimulating brain regions and distal brain regions connected to them. The findings in this study could be of guidance to clinical application of low-frequency rTMS.
Repetitive transcranial magnetic stimulation(rTMS) is a painless and non-invasive method for stimulation and modulation in the field of cognitive neuroscience research and clinical neurological regulation. In this paper, adult Wistar rats were divided into the rTMS group and control group randomly. Rats in the rTMS group were stimulated with 5 Hz rTMS for 14 days, while the rats in the control group did not accept any stimulation. Then, the behavior and local field potentials (LFPs) were recorded synchronously when the rats perform a working memory (WM) task with T-maze. Finally, the time-frequency distribution and coherence characteristics of the LFPs signal in the prefrontal cortex (PFC) during working memory task were analyzed. The results showed that the rats in the rTMS group needed less training days to reach the task correction criterion than the control group (P < 0.05). Compared with the control group, the rTMS group has higher energy (P < 0.01) in θ band (4~12 Hz) and γ band (30~80 Hz). The coherence between the channel pairs decreases as the spatial distance of the channel pairs increases, and the rTMS group exhibits a higher coherence than the control group (P < 0.01). It is concluded that 5 Hz rTMS can improve the excitability of rat prefrontal cortical neurons to a certain extent, and has a positive effect on the working memory ability of normal rats. The results of this paper may provide important theoretical support for further research on the mechanism of action of rTMS on WM.
ObjectiveTo observe the efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) applied at contralesional hemisphere Broca’s homologue on patients with global aphasia after left massive cerebral infarction. Methods Patients with global aphasia after left massive cerebral infarction in the Department of Neurorehabilitation of China Rehabilitation Research Center between August 2021 and December 2023 were selected. According to the random number table method, patients were randomly divided into a low-frequency rTMS group and a high-frequency rTMS group. rTMS targeted the mirror area within the right hemispheric Broca’s area. Patients’ language ability was assessed pre- and post-treatment by the Chinese version of the western aphasia battery (WAB). Results A total of 27 patients were included, with 14 in the low-frequency rTMS group and 13 in the high-frequency rTMS group. Before treatment, there was no statistically significant difference in the WAB test indicators between the two groups of patients (P>0.05). After treatment, WAB scores (spontaneous speech, auditory comprehension, naming, repetition, aphasia quotients) in both groups were significantly improved (P<0.05); compared to the low-frequency rTMS group, the high-frequency rTMS group exhibited significant improvement in spontaneous speech, auditory comprehension, repetition, naming and aphasia quotients (P<0.05). Conclusion The effect of high-frequency rTMS excitation to contralesional hemisphere is better than that of conventional low-frequency rTMS inhibition to contralesional hemisphere in improving the speech function of patients with global aphasia after left massive cerebral infarction.