Functional Connectivity Changes of the Visual Cortex in the Cervical Spondylotic Myelopathy Patients

Abstract

Study Design. Cross-sectional study. Objective To analyze altered functional connectivity (FC) in the visual cortex of cervical spondylotic myelopathy (CSM) patients using resting-state functional magnetic resonance imaging (fMRI). Summary of Background Data. We previously showed changes in visual cortex neural activity in CSM patients. Methods. Thirty CSM patients and 20 healthy controls were recruited. MR data were collected using a 3.0 T MR. FC of the regions of interest (ROI) (Brodmann areas [BA] 17/18/19/7) were calculated in a voxel-wise manner and compared between groups. Correlation analyses were performed between preoperative Japanese Orthopaedic Association (JOA) scores and altered FC, as well as between preoperative best corrected visual acuity (BCVA) and altered FC. Furthermore, the FC where was compared between the preoperative and the postoperative CSM patients in an ROI-wise manner. Results. Increased FC was found between BA19 and the cerebellum inferior lobe; between the left BA7 and bilateral calcarine, right lingual, right fusiform gyrus, and left precuneus (BA17); between the left BA7 and right fusiform gyrus and right inferior occipital gyrus (right BA19); and between the right BA7 and right superior lobe of cerebellum (right BA19) in CSM patients (P < 0.05). A negative correlation was found between JOA score and FC of the left and right BA19, and a positive correlation was found between the BCVA and FC of the left and right BA7 (P < 0.05). ROI analysis demonstrated statistically significant FC differences in between the preoperative and the postoperative CSM patients (P < 0.05). Conclusion. FC changes were present in the visual cortex of CSM patients, which negatively correlated with preoperative JOA scores and positively correlated with preoperative BCVA. Significant recovery of FC in the visual cortex was detected in CSM patients postoperatively. Level of Evidence: 4

Neural Correlates of Cognitive Dysfunctions in Cervical Spondylotic Myelopathy Patients: A Resting-State fMRI Study

“…Subsequently, the same group conducted seed-based functional connectivity analysis. They found that the functional connectivity within the visual network and the functional connectivity between secondary visual cortices and cerebellum were significantly increased in CSM patients (27). These results are consistent with previous studies, where there was decreased regional neural activities and enhanced connectivity (4,7,69).…”

“…Eleven healthy subjects of similar age, gender, and education were recruited through advertisements with the following inclusion criteria: (a) no evidence of spinal compression, (b) no ocular disease, (c) no other spinal or brain neurological disorders, or systemic disease, and (d) ability to complete fMRI studies. We have previously reported detailed participants' information (27).…”

“…In neuroimaging studies of CSM, fMRI has illuminated functional alterations in motor cortices (4,7,10,24,25). Using resting-state fMRI (rs-fMRI), we have previously identified alterations in functional connectivity in visual cortices that correlate with visual and motor function in CSM patients (26,27).…”

Enhanced Information Flow From Cerebellum to Secondary Visual Cortices Leads to Better Surgery Outcome in Degenerative Cervical Myelopathy Patients: A Stochastic Dynamic Causal Modeling Study With Functional Magnetic Resonance Imaging

“…One possible explanation is that patients with DCM gradually adapted the altered visual input during long-term neurological dysfunctions and formed more efficient feedback modulation (from the cerebellum to bilateral LOC) to compensate for visual impairments, therefore leading to better visual recovery following surgery. These findings provided evidence that cerebellum and LOC areas participate in visual compensations, which may be important for better motor function (Chen et al, 2019 ) in patients with DCM. At first glance, the increased connection between the cerebellum and secondary visual cortex may seem surprising.…”

“…Considering the importance of cerebellum and LOC in visual-motion perception, these findings indicated that abnormal visual processing may play an important role in motor deficits in patients with DCM. One possible explanation is that the information integration between these two regions was increased to compensate for impaired visual acuity in patients with DCM and resulted in better visual feedback during motor function (Chen et al, 2019 ).…”