Abstract:

Objective To observe effect of repetitive transcranial magnetic stimulation (rTMS) combined with repetitive peripheral magnetic stimulation (rPMS) on upper extremities motor function in patients with cerebral hemorrhage, and its mechanism of brain function remodeling using functional magenetic resonance imaging (fMRI).
Methods From September, 2020 to November, 2021, 40 patients with cerebral hemorrhage were randomly divided into central group (n = 13), peripheral group (n = 13) and combination group (n = 14). All patients received routine medication and physical therapy. The central group received low-frequency rTMS at 1 Hz in M1 area of the contralateral brain, the peripheral group received rPMS in the Erb's point of affected side, and the the combination group received rTMS combined with rPMS, for three weeks. They were assessed with Fulg-Meyer Assessment-Upper Extremities (FMA-UE) and modified Barthel index (MBI) before and after treatment, respectively. At the same time, resting-state fMRI (rs-fMRI) scanning was performed by using 3.0 T whole-body magnetic resonance imaging system, and the changes of functional connection between M1 area and other brain areas of the whole brain were observed. Spearman correlation analysis was used to explore the correlation between functional connectivity strength (FCS) differences in brain regions and FMA-UE score differences before and after treatment in the combination group.
Results The intra-group effect (F > 106.646, P < 0.001), inter-group effect (F > 4.296, P < 0.001) and interaction effect (F > 9.583, P < 0.001) were significant in the scores of FMA-UE and MBI among groups, while the combination group was the best. After treatment, the functional connectivity (FC) to regins of intrest (ROI) 1 (left/affected M1 area) enhanced in the right posterior central gyrus and the left superior temporal gyrus, and reduced in the left superior frontal gyrus and the right posterior cerebellum. The FC to ROI2 (right/unaffected M1 area) enhanced in the left anterior central gyrus, the left anterior cuneiform lobe and the left inferior frontal gyrus, and reduced in the left middle occipital gyrus and the right insula. Compared with the peripheral group, no enhanced FC was found to ROI1 in the combination group, and the FC reduced in the left middle occipital gyrus; no enhanced FC was found in ROI1, and FC reduced in the left anterior cuneiform lobe and the left thalamus. Compared with the central group, the FC to ROI1 enhanced in the right posterior central gyrus and the right superior marginal gyrus in the combination group, and reduced in the left cerebellar lobe and the right thalamus; the FC to ROI2 enhanced in the left central posterior gyrus and the right superior frontal gyrus, and reduced in the left inferior frontal gyrus and the right posterior cerebellum. The FCS difference in the right central posterior gyrus (r = 0.416, P = 0.013), left superior temporal gyrus (r = 0.658, P = 0.020), left central anterior gyrus (r = 0.695, P = 0.010), left inferior frontal gyrus (r = 0.537, P = 0.020), and left anterior cuneiform lobe (r = 0.613, P = 0.030) before and after treatment in the combined group was positively correlated with the difference of FMA-UE scores; the FCS difference in the left occipital gyrus (r = -0.554, P = 0.039) was negatively correlated with the difference of FMA-UE score.
Conclusion rTMS combined with rPMS can improve the motor function of upper extremities more effectively after cerebral hemorrhage, which may associate with low-frequency rTMS indirectly activating the motor cortex of the affected side and promoting the downward projection of corticospinal tract; the high frequency rPMS of the affected upper extremities enhancing the activation of SMC area by the ascending pathway; to reorganize important brain regions in sensorimotor network and default network.

Key words: stroke, repeated transcranial magnetic stimulation, repetitive peripheral magnetic stimulation, functional magenetic resonance imaging, upper extremity, motor function, randomized controlled trial