Effects Of Motor Imagery Therapy On Function Rehabilitation Of Stroke Patients With Hemiplegia

Motor imagery therapy has gradually been proved to be effective on the motor recovery of stroke patients with hemiplegia.However,the neural mechanisms that explain why motor imagery improves motor function in patients with hemiplegia have not yet been elucidated.Functional magnetic resonance imaging has been employed in this paper to study the abnormal structure and function in the brain of stroke patients with hemiplegia.Subsquently,combined with motor imagery therapy,we evaluated the changes of brian function before and after the rehabilitation of the stroke patients with hemiplegia,as well as the relationship between the brain function and the behavioral scores of the stroke patients.Main contents are as follows.Part 1: Abnormal resting-state network of the stroke patients.Independent component analysis was performed to obtain the motor network and the DMN of the stroke patients and the healthy controls(HCs).Two sample t-tests were used to compare the differences of the motor network and the DMN between the patients and HCs.Additionally,correlations between the network connectivity and the behavioral scores of the stroke patients were studied.Compared with the HCs,the motor network connectivity of the stroke patients was significantly increased in the contralesional superior parietal lobule,but decreased in ipsilesional M1.The DMN connectivity of the stroke patients was significantly increased in the contralesional middle frontal gyrus,but decreased in bilateral precuneus,ipsilesional supramarginal and angular gyrus.Moreover,the motor network connectivity of the contralesional superior parietal lobule was positively correlated with the Fugl-Meyer assessment(FMA)score of the stroke patients.Our results showed abnormal motor network and DMN during the resting-state of the stroke patients,suggesting that resting-state network connectivity could serve as biomarkers for future stroke studies.Brain–behavior relationships could be taken into account while evaluating stroke patients.Graph theoretical analysis was employed to investigate the abnormal topological properties of structural and functional brain networks in the stroke patients.We found that both stroke patients and HCs exhibited small-world organization in brain networks.Compared to HCs,the stroke patients exhibited abnormal global properties characterized by higher characteristic path length and lower global efficiency.Furthermore,the stroke patients showed altered hub distribution and nodal characteristics,primarily in certain motor-and cognition-related regions.In stroke patients,there was a positive correlation between the nodal degree of the inferior parietal lobule and FMA and a positive correlation between the nodal betweenness centrality of the posterior cingulate gyrus and immediate recall.Most importantly,the strength of structural–functional connectivity network coupling was decreased and the coupling degree was related to the FMA of the patients,which suggests that the decoupling may provide a novel biomarker for the assessment of motor impairment in stroke.These results provided insight into the structural and functional organization of the brain after stroke from the viewpoint of network topology.Part 2: Changes of resting state brain function before and after the motor imagery+conventional rehabilitation of the stroke patients.Resting state fMRI data were collected for subcortical stroke patients before and after the rehabilitation treatment.All the patients accepted the motor imagery+ conventional rehabilitation therapy for 30 days.Compared to the HCs,the stroke patients exhibited the increased ReHo value mainly in the right occipital cortex,right superior parietal gyrus,right superior frontal gyrus,right insula,right putamen,left inferior parietal gyrus,left middle frontal gyrus,left medial superior frontal cortex and left precuneus.After the treatment,the stroke patients exhibited significant ReHo decrease in the right superior occipital gyrus,right parietal cortex,right medial superior frontal gyrus,left middle frontal gyrus and left inferior orbitofrontal cortex.ReHo value increased mainly in bilateral precuneus,right middle cingulum,left SMA,right postcentral gyrus,right middle temporal gyrus and left superior parietal gyrus.our results showed the improvement of the motor function in the patients‘ brain,thus may demonstrate that MI treatment could promote the brain functional recovery after stroke on some level.Compared with the HCs,the FC in the patient group was significantly increased between the ipsilesional M1 and the ipsilesional inferior parietal cortex,frontal gyrus,supplementary motor area and contralesional angular and decreased between the ipsilesional M1 and bilateral M1.After the treatment,the FC between the ipsilesional M1 and contralesional M1 increased,while the FC between the ipsilesional M1 and ipsilesional SMA and paracentral lobule decreased.A statistically significant correlation was found between the FC change in the bilateral M1 and the Fugl-Meyer assessment score change.Our results revealed an abnormal motor network after stroke,and suggested that the FC could serve as a biomarker of motor function recovery in stroke patients with hemiplegia.Part 3: Effects of motor imagery therapy on function rehabilitation of stroke patients with hemiplegia.20 stroke patients were randomly divided into 2 groups.One of which underwent 30 days of rehabilitation intervention+ MI therapy(MI group)and the other underwent only the conventional rehabilitation intervention(CRI group).Study the brain function while the subjects taking the motor execution(ME)and MI task.Compared with the HCs,the CRI group showed increased activation in right superior frontal gyrus and left middle frontal gyrus while performing the ME task of the Ipsilateral hand.Decreased activation was found in right SMA,left M1 and left paracentral lobule.After the treatment,the activation of the right SMA,middle frontal gyrus and superior parietal lobe increased.Compared with the HCs,the CRI group showed increased activation in bilateral paracentral lobule while performing the MI task of the ipsilateral hand.Compared with the HCs,the MI group showed increased activation in right SMA,right M1 and right paracentral lobule while performing the ME task of the ipsilateral hand.Decreased activation was found in left SMA and left M1.After the treatment,the activation of the right SMA,right M1 and left paracentral lobule decreased,while the activation of theleft middle frontal gyrus increased.Compared with the HCs,the MI group showed decreased activation in right middle frontal gyrus,right M1,bilateral SMA,and increased activation in left M1 while performing the MI task of the Ipsilateral hand.After the treatment,the activation of the right inferior parietal lobe,left M1 and leftprecuneus decreased.Two group all showed functional recovery of the brain while performing the ME task.However,the MI group showed more obvious functional recovery of the brain while performing the MI task,suggesting the Effects of motor imagery therapy on function rehabilitation of stroke patients with hemiplegia.