Both ALFF/ReHo value changes and positive correlations of these changes with BCVA were demonstrated in CSM. The FC between the visual cortex and posterior cingulate lobe was also increased in CSM.

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

Cervical spondylotic myelopathy (CSM) is a common disease of the elderly that is characterized by gait instability, sensorimotor deficits, etc. Recurrent symptoms including memory loss, poor attention, etc. have also been reported in recent studies. However, these have been rarely investigated in CSM patients. To investigate the cognitive deficits and their correlation with brain functional alterations, we conducted resting-state fMRI (rs-fMRI) signal variability. This is a novel indicator in the neuroimaging field for assessing the regional neural activity in CSM patients. Further, to explore the network changes in patients, functional connectivity (FC) and graph theory analyses were performed. Compared with the controls, the signal variabilities were significantly lower in the widespread brain regions especially at the default mode network (DMN), visual network, and somatosensory network. The altered inferior parietal lobule signal variability positively correlated with the cognitive function level. Moreover, the FC and the global efficiency of DMN increased in patients with CSM and positively correlated with the cognitive function level. According to the study results, (1) the cervical spondylotic myelopathy patients exhibited regional neural impairments, which correlated with the severity of cognitive deficits in the DMN brain regions, and (2) the increased FC and global efficiency of DMN can compensate for the regional impairment.

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Degenerative cervical myelopathy (DCM) damages the spinal cord, resulting in long-term neurological impairment including motor and visual deficits. Given that visual feedback is crucial in guiding movements, the visual disorder may be a cause of motor deficits in patients with DCM. It has been shown that increased functional connectivity between secondary visual cortices and cerebellum, which are functionally related to the visually guided movements, was correlated with motor function in patients with DCM. One possible explanation is that the information integration between these regions was increased to compensate for impaired visual acuity in patients with DCM and resulted in better visual feedback during motor function. However, direct evidence supporting this hypothesis is lacking. To test this hypothesis and explore in more detail the information flow within the “visual-cerebellum” system, we measured the effective connectivity (EC) among the “visual-cerebellum” system via dynamic causal modeling and then tested the relationship between the EC and visual ability in patients with DCM. Furthermore, the multivariate pattern analysis was performed to detect the relationship between the pattern of EC and motor function in patients with DCM. We found (1) significant increases of the bidirectional connections between bilateral secondary visual cortices and cerebellum were observed in patients with DCM; (2) the increased self-connection of the cerebellum was positively correlated with the impaired visual acuity in patients; (3) the amplitude of effectivity from the cerebellum to secondary visual cortices was positively correlated with better visual recovery following spinal cord decompression surgery; and (4) the pattern of EC among the visual-cerebellum system could be used to predict the pre-operative motor function. In conclusion, this study provided direct evidence that the increased information integration within the “visual-cerebellum” system compensated for visual impairments, which might have importance for sustaining better motor function in patients with DCM.

Objective: To investigate the biomechanical effect of different intervertebral reconstructive heights on adjacent segments following C 5 /C 6 anterior cervical discectomy and fusion (ACDF) through finite element analysis.Methods: A finite element model of intact C 4 -C 7 segments was developed and validated for the present study. Five additional C 4 -C 7 postoperative models were constructed with 100%, 125%, 150%, 175%, and 200% of the benchmark height of C 5 /C 6 on the basis of the intact model. The changes in intradiscal pressure (IDP) and range of motion (ROM) of adjacent segments before and after reconstruction of C 5 /C 6 were analyzed.Results: For the upper adjacent segment (C 4 /C 5 ), the IDPs under the different loading conditions all increased after reconstruction. The maximum IDPs were 0.387, 0.489, 0.491, and 0.472 MPa under flexion, extension, axial rotation, and lateral bending, respectively, observed at the reconstructive height of 200%. The minimum IDPs were observed at 150% reconstructive height under all loading conditions except extension, and were 57, 86 and 81% of the maximum IDPs under flexion, axial rotation, and lateral bending, respectively. The minimum IDP under extension occurred when the reconstructive height is 125% of the benchmark height. For the lower adjacent segment (C 6 /C 7 ), the IDPs of postoperative models under all loading conditions also increased compared to the preoperative model. The maximum IDPs after reconstruction under flexion, extension, axial rotation, and lateral bending were 0.402, 0.411, 0.461, and 0.497 MPa, respectively, when the height of the reconstruction was 200% of the benchmark. The minimum IDPs were observed after a reconstruction at 150% of the benchmark, and were 59%, 85%, 82%, and 81% of the maximum IDPs under flexion, extension, axial rotation, and lateral bending loading conditions. Conclusions:The reconstructive height is an important factor affecting the IDP and the ROM of adjacent segments after ACDF. To delay the adjacent segment disease, an intervertebral reconstructive height of 150% is an appropriate height in C 5 /C 6 ACDF.

Developing an objective biomarker for pain assessment is crucial for understanding neural coding mechanisms of pain in the human brain as well as for effective treatment of pain disorders. Neuroimaging techniques have been proven to be powerful tools in the ongoing quest for a pain signature in the human brain. Although there is still a long way to go before achieving a truly successful pain signature based on neuroimaging techniques, important progresses have been made through great efforts in the last two decades by the Pain Society. Here, we focus on neural responses to transient painful stimuli in healthy people, and review the relevant studies on the identification of a neuroimaging signature for pain.

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