Effect Of Mirror Therapy On Lower Extremity Dysfunction In Patients With Ischemic Stroke: A Rs-fMRI Study

Purpose: Based on the changes in brain functions of ischemic stroke-induced hemiplegic patients after resting-states functional magnetic resonance imaging(rs-f MRI)mirror therapy,this paper discusses the therapeutical effect of mirror therapy on the lower extremity motor dysfunction of ischemic stroke-induced hemiplegia patients and the possible neural mechanism,so as to provide possible theoretical basis for restoration of lower extremity motor function of hemiplegia patients through mirror therapy.Object and method: Forty cases of ischemic stroke patients having received therapy in Sichuan Provincial People's Hospital from Mar.2016 to Jun.2017 were chosen as experiment objects and divided equally and randomly into two groups,i.e.routine rehabilitation group and mirror therapy group,the former subjected to normal rehabilitation therapy including clinical medication and traditional rehabilitation while the latter additionally subjected to mirror therapy specific to lower limbs on that basis for a therapy period of 3 weeks.Both before and after therapy,all objects were assessed in terms of motor function of lower limbs,balance function,transfer ability,daily life ability and ambulation ability with Fugl-Meyer Assessment(FMA),Berg Balance Scale(BBS),Modified Rivermead Mobility Index(MRMI),Modified Barthel Index(MBI)and Functional Ambulation Category Scale(FAC)respectively.Besides,all objects were scanned before and after therapy with Siemens Tim Trio3.0T magnetic resonance imaging system through conventional T1 weighted imaging(T1W1),T2 weighted imaging(T2W1),FLAIR,3D anatomy imaging,and resting-state function-magnetic resonance imaging(rs-f MRI).All rs-f MRI data were processed and analyzed with Metlab2013a-based DPARSF and SPM8 software.First,a comparison was made between the two groups of patients in terms of the changes after therapy in resting-state functional connectivity between the center point of primary motor cortex(M1region),selected as the region of interest(ROI),and other voxels of brain;then,another comparison was made in terms of the changes in neuron activities in brain functional region based on the measured regional homogeneity(Re Ho)and fractional amplitude of low-frequency fluctuate(f ALFF).Based on statistic analysis with SPM8 software,a two-sample t-test was made of the above measurements,a report on the coordinate and peak of the location of changed region with statistical significance,and an analysis of the correlation of Re Ho and f ALFF values of M1 region on the affected side and functional connectivity values of M1 and PM regions on the affected side with FMA score of lower limbers.Results: 1.After therapy,FMA,BBS,MRMI and MBI scores of lower limbs of both groups of patients have all significantly improved(P <0.01)and those of the mirror therapy group have improved significantly higher than those of the conventional rehabilitation group(P <0.05).Statistic difference in FAC score has only been found before and after therapy of the same group(P <0.01)but not between two groups after therapy(P >0.05).2.It is revealed through analysis of functional connectivity after therapy of the two groups that for the mirror therapy group,the functional connectivity between the M1 region on the affected side and the superior frontal gyrus,thalamus and paracentral lobule,posterior central gyrus,superior parietal gyrus and parahippocampal gyrus on the affected side has improved and that between the M1 region on the affected side and the middle frontal gyrus has weakened;the functional connectivity between the M1 region on the unaffected side and the superior parietal lobule,inferior frontal gyrus,parahippocampal gyrus,precentral gyrus on the unaffected side,precuneus on the unaffected side,thalamus on the unaffected side and superior occipital gyrus on the unaffected side has improved.It is discovered through comparison between the two groups that for the mirror therapy group,Re Ho value has increased in such regions as superior frontal gyrus,precentral gyrus,cerebellum,inferior parietal lobule,middle occipital gyrus,cingulate gyrus,and postcentral gyrus and precuneus on the affected side while decreased in such regions as middle temporal gyrus,medial frontal gyrus and supramarginal gyrus.It is also discovered through comparison between the two groups that for the mirror therapy group,the regions where f ALFF value has increased mainly include cerebellum,superior frontal gyrus,postcentral gyrus,precuneus and supplementary motor area,paracentral lobule and precentral gyrus on the affected side and those where f ALFF value has decreased mainly include right inferior frontal gyrus,inferior occipital gyrus and inferior temporal gyrus.3.Re Ho and f ALFF values of the M1 region on the affected side and the functional connectivity values of the M1 and PM regions on the affected side have shown a positive correlation with the FMA score of lower limbs.Conclusion: This research shows that mirror therapy can accelerate restoration of lower extremity motor function of ischemic stroke-induced hemiplegic patients and it is also discovered through contrastive analysis of rs-f MRI data that mirror therapy can promote functional reorganization of the brain affected by ischemic stroke.