Study On Gait Instability And Brain Remodeling In Cervical Spondylotic Myelopathy

Objective By studying patients with normal or abnormal gait with cervical spondylotic myelopathy(CSM),we analyzed the brain function and spinal tracts structures in CSM patients with different gaits,as well as the relationship between the remodeling of the brain and spinal cord and gait instability.Methods According to the CSM patients’ gait,we divided thirty-two patients into two groups: normal gait patients(nPT)and abnormal gait patients(aPT),and sixteen right-handed healthy controls(HC)were also recruited.Voxel-wise z-score transformation amplitude of low-frequency fluctuations(zALFF)was performed for estimating brain changes,and these statistically different brain regions were chosen as seed regions for seed-based functional connectivity calculation to found the different functional connectivity between n PT and a PT.We chose several spinal cord tracts are related to locomotion and gait,including fasciculus gracilis(FCG),fasciculus cuneatus(FCC),lateral corticospinal tract(CST)and spinocerebellar tract(SCT).Cross-sectional area(CSA)and fractional anisotropy(FA)of the spinal cord were computed by spinal cord toolbox for observing spinal cord changes.Finally,correlations of these measures and the modified Japanese Orthopedic Association(m JOA)score were analyzed to explore the correlation between clinical function and imaging features.Results Compared with HC,we found that the zALFF of caudate nucleus in n PT and a PT was decreased.The zALFF of the right postcentral gyrus and paracentral lobule in a PT and n PT was lower than those of HC.Compared with n PT,the zALFF of caudate nucleus in a PT was higher.Compared with the n PT,the a PT showed increased functional connectivity between the caudate nucleus and left angular gyrus,bilateral precuneus and bilateral posterior cingulate cortex(PCC),which constitute a vital section of the default mode network(DMN).No significantly different FA values or CSA of spinal tracts at the C2 level were observed between the HC,n PT and a PT groups.We analyzed the correlations between these changed function and functional connectivity of brain aeras and the structure of spinal tracts in CSM,the right paracentral lobule’s zALFF was negatively correlated with the FA value of fasciculus gracilis(FCG),and the right caudate zALFF was positively correlated with the FA value of the fasciculus cuneatus(FCC).The results showed that the functional connectivity between the right caudate nucleus and DMN was negatively correlated with the CSA of the lateral corticospinal tract(CST).Finally,we analyzed the correlation between clinical function and imaging features.A positive correlation was observed between patients’ m JOA and FA values of SCT at the C2 level.Furthermore,patients’ m JOA and m JOA lower extremity scores were correlated with the functional connectivity between the right caudate nucleus and DMN.Conclusion In CSM,the spinal tracts microstructures at C2 level might not be corelated to the gait instability.The activation of the caudate nucleus likely plays an important role in the generation of gait instability.Furthermore,the strengthening functional connectivity between the caudate nucleus and DMN seems to compensate for gait instability.Correlations between spinal cord and brain function might be related to the clinical symptoms in CSM.