To investigate the therapeutic effect and explore the neural mechanisms of motor imagination therapy from the perspective of embodied cognition (hereafter referred to as embodied motor imagination therapy) combined with conventional rehabilitation on sensorimotor network (SMN) of first-episode stroke patients with hemiplegia.

From January to June 2020, 15 first-episode stroke patients with hemiplegia who were hospitalized in the Neurology Department and Rehabilitation Medicine Department of the Affiliated Brain Hospital of Nanjing Medical University were selected to be included in the experimental group for embodied motor imagination therapy combined with conventional rehabilitation. At the same time, 15 healthy subjects matched with the experimental group in age, sex and education were selected as the control group. Before and after 4 weeks of treatment, the experimental group received the Fugl-Meyer assessment (FMA) and the modified Bathel index (MBI) and the fMRI scan. The functional magnetic resonance (fMRI) was used to construct the SMN, and study these changes within the network through the functional connectivity analysis of SMN brain regions in the experimental group before and after treatment and in healthy controls. Besides, functional connectivity (FC) reorganization between S1M1 and the whole brain was investigated using changes in functional connectivity between the primary sensory-motor cortex (S1M1) and the whole brain based on seed points on the side of injury.

After treatment, the FMA score of the experimental group increased from (65.67±16.95) to (149.58±17.95) and the MBI score increased from (24.17±8.21) to (65.00±8.79), with statistically significant differences (P<0.05). Functional connectivity within the SMN showed that before treatment, the patients in the embodied cognitive group had lower functional connections than the healthy control group between the affected bilateral S1M1, the affected side S1M1-SMA, the affected side S1M1-cerebellum, and SMA-cerebellum (P<0.05). After treatment, the functional connections between the affected S1M1 and the affected frontal middle gyrus and the healthy postcentral gyrus were enhanced compared with those before treatment in the experimental group (P<0.05). The whole-brain FC analysis showed that effective connections from the affected S1M1 to the healthy talar gyrus and the affected postcentral gyrus were diminished in the test group before treatment (P<0.05). After treatment, the functional connections from the affected S1M1 to the affected frontal middle gyrus and the healthy cerebellar gyrus were enhanced (P<0.05). Correlation analysis revealed that the incremental FC connection strength of the affected S1M1 and cerebellum was moderately correlated with the incremental FMA (r=0.581, P=0.023) and strongly correlated with the incremental MBI (r=0.757, P=0.002).

Embodied motor imagination therapy combined with conventional rehabilitation can improve the motor function and daily living ability of the first-episode stroke patients with hemiplegia. The relevant brain remodeling mechanism may be that the functional connectivity within and between the SMN of patients was significantly repaired, and the functional connectivity of brain regions related to cognition was also increased.