Effect of brain computer interface on limb motor function after intracerebral hemorrhage in basal ganglia and its rehabilitation mechanism

Objective: Objective to explore the degree of recovery of limb motor function and potential rehabilitation mechanism of stroke patients with subacute basal ganglia cerebral hemorrhage after receiving rehabilitation training based on brain computer interface (BCI) of motor imagination. Methods: During hospitalization from December 2022 to October 2024, stroke patients with subacute basal ganglia intracerebral hemorrhage accompanied with limb movement disorder were randomly divided into conventional rehabilitation treatment group (Group C) and BCI group (group B), who completed traditional rehabilitation training, BCI training combined with traditional rehabilitation training, and the training time was 5 weeks. Before and after the training, the rehabilitation status of stroke patients was evaluated by Fugl Meyer Assessment Scale (FMA), simple mental state examination scale, modified Barthel index, online classification accuracy (CA), Brunnstrom staging, etc. Then resting state fMRI scanning was performed to compare the functional connectivity changes between the regions of interest and the whole brain. The imaginary part coherence analysis method was used to calculate the connectivity changes between channels in the 8-30hz frequency band of EEG, and the changes of power spectral density (PSD) and brain topography in the two stages before and after training. Results: A total of 44 stroke patients were included in this study, 22 in group C and 22 in group B. There was no significant difference in clinical related scores between the two groups before training ( P >0.05); After training, compared with group C, the FMA score of group B stroke patients was significantly improved ( P <0.05). The CA values of most stroke patients in group B showed fluctuations and a downward trend, and only 6 stroke patients could maintain relatively high Ca values (more than 70% threshold standard).In group B, the functional connectivity between sensorimotor network and default mode, ventral attention, language network and other networks was significantly enhanced in 19 stroke patients ( P <0.05). Among them, the connection between the prefrontal side of the left precentral gyrus (L_PEF) and the anterior parietal side of the left postcentral gyrus (L_3b), and the connection between the anterior inferior cortex of the left precentral gyrus (L_6v) and the lateral side of the left postcentral gyrus (L_1) were positively correlated with clinical scores ( P <0.05). The connectivity between multiple channels within 4-30hz (αandβfrequency bands) of EEG was significantly weakened, and the enhanced connectivity between C4-T7 and T8-T7 in theαfrequency band during the execution of motor imagination by the affected hand was positively correlated with the change of lower limb clinical score. After training, the PSD curve in the range of 8-30hz in the central motor area of the affected side of the brain tended to be smoother than before, and the energy value decreased to a certain extent; Through the changes of brain topographic map before and after, it was found that during the repeated training of the affected hands of many stroke patients, the ipsilateral hemisphere cortex had obvious personal leave related desynchronization phenomenon or this phenomenon was further enhanced than before, and tended to converge to the central region of the brain and the surrounding areas. Conclusion： BCI rehabilitation training can effectively promote the recovery of limb motor function in stroke patients with subacute basal ganglia cerebral hemorrhage. The possible mechanism of rehabilitation lies in enhancing the motor imagination ability of stroke patients and promoting the improvement of brain network activity.