Is the Presence or Absence of Cerebrospinal Fluid on Pre-operative Imaging Associated with Cervical Myelopathy Diagnosis or Outcomes?

Introduction: Degenerative cervical myelopathy (DCM) is a clinical diagnosis based on history and physical exam that demonstrates neurologic dysfunction. Pre-operative imaging is commonly used to determine the source of cord compression in DCM. While cord shape change and signal change on MRI have been used as indicators of cord compression, it is unclear if the presence or amount of CSF around the cord can serve as a proxy for cord compression. The purpose of this study was to determine whether the amount of CSF around the cord on pre-operative imaging is associated with the severity of DCM or with post-operative outcome.

Methods: This study was a retrospective chart review of patients undergoing single level anterior cervical discectomy and fusion (ACDF) for DCM. Pre- and post-operative patient reported health outcomes such as Visual Analog Scale for Neck Pain (VAS-NP) and modified Japanese Orthopaedic Association (mJOA) were collected and correlated with presence of cerebrospinal fluid at the level of ACDF as well as one level above and below. This was assessed by comparing the area of the spinal canal to the area of the spinal cord on preoperative MRI.

Results: 255 patients were included. Patients without CSF at the level of operation were more likely to be older (mean of 63.17 years, p=0.002) and more likely to be male (67%, p=0.017). Spearman Correlation tests were utilized to compare cord/canal ratios and pre-operative (R: -0.031, p=0.787) and six-month postoperative (R: 0.055, p=0.771) mJOA scores. These showed no significant correlations between CSF presence and outcomes.

Conclusion : The amount of CSF around the cord was not associated with severity of myelopathy or post-operative outcomes. As such, CSF around the cord may not be a reliable metric when evaluating the cervical spine for surgical planning in DCM.