Studies On The Degeneration Of Sensorimotor Tract And Brain Remodeling In Degenerative Cervical Myelopathy

Objective By the study of degenerative cervical myelopathy（DCM）of different severity,we analyzed the degeneration of lateral corticospinal tract（CST）,fasciculus gracilis and fasciculus cuneatuc tract（FGC）of the cervical spinal cord,as well as the changes of brain structure.Methods Twenty-four DCM patients were divide d into Hyperintensity（HS）and non-Hyperintensity（n HS）groups according to the signal of compression segments in T2 WI,then FA and ADC ratios at diffe rent levels of CST and FGC above compression（C1/2-C4/5）in DCM patients were compared with ten healthy co ntrols（HC）,which aimed to discover whether the CST and FGC changed in FA and ADC values,and whether th is change was related to the degree of compres sion and different segments.After excluding 4 patients with substandard quality brain data,brain structural images of these 20 patients were classified into hyperintensity and non-hyperintensity based on the signal in cervical T2 WI.Finally,using voxel based morphometry（VBM）technique to analyze the volume o f brain between HS,n HS and healthy controls.Tr act-based spatial statistics（TBSS）was applied to estimate the difference of tracts in the white mater.Results Compared with HCs,in DCM patients,FA ratio of CST in HS and n HS groups was decreased at all levels（C1/2-C4/5）（P < 0.05）,while ADC ratio was increased only in C4/5 levels in HS group.The FA ratio of FGC was decreased in the C3/4 and C4/5 levels in the HS group,and only decreased in the C4 /5 level in n HS group,while the ADC ratio was increased only in the C4/5 level in the HS group.In VBM a nalysis,the volume of precentral gyrus,postcentral gyrus and paracentral lobule increased in patients compared with controls.In TBSS analysis,no significance was found in sensorimotor tract between patients and the control group.The volume of region o f interest in HS and n HS was negatively correlated with C1/2 FA ratio of CST.Conclusion In patients with DCM,the degeneration distance of CST and FGC is farther than that of the control group,and the degeneration distance of these tracts in patients wi th hyperintensity is farther than that with non-hyperintensity.This difference of degeneration distance may be related to the difference of gray and w hite matter physical features,compression and injury degree of cervical spinal cord.In the analysis of brain structure,the increase of brain volume is mainly concentrated in the sensorimotor area,which may be a compensatory change.