Alteration Of Reho And VBM Within The Sensorimotor Network In Cervical Spondylotic Myelopathy: A FMRI Study

Objective: Using resting-state functional magnetic resonance imaging(rs-f MRI) technology of regional homogeneity(Re Ho) and voxel-based morphometry(VBM), study brain changes of local functional connectivity and cortical gray volume within the sensorimotor network(SMN) on patients with spondylotic myelopathy(CSM) before and after cervical cord surgical decompression. Then discuss its structure and function damage mechanism within sensorimotor cortex and its the neural plasticity mechanisms involved in post-decompression CSM.Methods: Thirty-eight CSM patients, 21 CSM patients follow-up 3 months after surgery and 38 age-, sex- and level of education matched healthy volunteers underwent rs-f MRI scans by 3.0 T MR. Then Re Ho and VBM measurements were performed statistical within SMN mask by second-level random-effect or paired 2-tailed student t test(p values less than 0.05 were considered significant), and assess Re Ho and cortical gray volume alterations of within pre- and post-decompression CSM and healthy controls(HC), alternately, as well as its correlations to clinical indices by Pearson correlation.Results: 21 cases of postoperative CSM underwent MRI scans again 3 month later, 17 cases failed to follow-up as scheduled. Pre-decompression CSM patients demonstrate a significantly lower Re Ho in the left primary sensory cortex and primary motor cortex(Post G/ Pre G), but enhanced Re Ho in the right superior parietal lobule(SPL) in comparison to HC. Comparing with pre-decompression, the post-decompression CSM patients show increased Re Ho in the left Post G/ Pre G but significantly lower Re Ho in the right SPL when comparing with HC. Compared with HC, pre-decompression CSM show reduced gray matter volume in left cerebellum anterior lobe, left inferior parietal lobule, right middle frontal gyrus, the right Post G/ Pre G and bilateral insula. After 3 months, post-decompression CSM find decreased gray matter volume in left cerebellar posterior lobe, right middle/superior temporal gyrus, thalamus, bilateral SMA compared with preoperative, however, gray matter volume increase in left SPL, right inferior parietal lobule, right Post G/ Pre G; Compared with HC, gray matter volume decreases in bilateral insula but increase in bilateral cerebellum anterior lobe in post-decompression CSM(GRF correction, P < 0.05).Abnormal Re Ho areas or gray volume in CSM patients pre-decompression or post- decompression show no significantly correlation with JOA scores, NDI scores and Disease duration(P > 0.05).Conclusion: Myelopathy in cervical cord may affect intrinsic cerebral activity, as patients with CSM show disrupted regional homogeneity within sensorimotor network; abnormal Re Ho tending to be normal following decompression suggest sensorimotor cortex influence functional recovery;Sensorimotor cortex demonstrate structural damage and reorganization in CSM patients.