A Combination of Functional Magnetic Resonance Imaging and Diffusion Tensor Image to Explore Structure–function Relationship in Healthy and Myelopathic Spinal Cord

Background: Cervical spondylotic myelopathy (CSM) is a degenerative disorder that can chronically damage the spinal cord. The aim of this study was to investigate the column-specific degeneration in the cervical cord with CSM and explore the structure-function relationship by diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI).Patients and methods: DTI and blood-oxygen-level-dependent (BOLD) fMRI were obtained from 14 healthy controls and six patients with CSM at 3 T. The fractional anisotropy (FA) value of anterior, lateral, and posterior column and the BOLD signal in response to somatosensory stimulation were compared among three groups: the average value of levels from C3 to C8 in the control and CSM groups and the value at maximal compression site in the CSM (CSM-mc) group. The correlation between FA value and BOLD signal was used to assess the structure-function relationship.Results: The FA value in CSM-mc was lower than control-ave in all the columns (P<0.01) and lower than CSM-ave in the lateral and posterior column (P<0.05). The BOLD signal in CSM was significantly higher than that in the control (P<0.001). In the posterior column, a significant correlation between BOLD signal and FA value was found (P<0.05).Conclusion: This study demonstrated that the microstructural damage in CSM was correlated with functional changes. DTI combined with fMRI reveals the relationship between structural damage and neural activity, which might provide a promising method to reveal the underlying pathomechanism of CSM.