Metabolic Imaging Using Proton Magnetic Spectroscopy as a Predictor of Outcome After Surgery for Cervical Spondylotic Myelopathy
A single-center magnetic resonance spectroscopy (MRS) imaging and surgical outcome study involving 16 patients with cervical spondylotic myelopathy (CSM).Objective:
In the present study, we assess the utility of MRS to quantify metabolic changes within the spinal cord and predict surgical outcome in CSM patients.Summary of Background Data:
MRS is an advanced spinal imaging modality that can provide pertinent metabolic and biochemical information regarding spinal cord function. Previous studies have demonstrated significant abnormalities in specific cellular metabolite concentrations in CSM patients.Methods:
Sixteen patients with CSM were evaluated. Single voxel MRS was performed in the cervical cord. N-acetyl-aspartate (NAA) and choline metabolite concentration ratios with respect to creatine were quantified, as well as the presence or absence of a lactate peak. The modified Japanese Orthopaedic Association (mJOA) scale was used as the functional assessment measure. Correlation of MRS metabolites with change in mJOA score was performed.Results:
The mean follow-up time was 19 months. There was a statistically significant improvement between mean preoperative and postoperative mJOA score after surgery (P<0.0001). The NAA/Cr ratio demonstrated a significant relationship to the change in mJOA score after surgery (P=0.0479; R2=0.2513). The Cho/NAA ratio demonstrated an even stronger correlation with the change in mJOA score after surgery (P=0.0065; R2=0.4219). Neither the Cho/Cr ratio, nor the presence of a lactate peak or T2-weighted signal change was significantly correlated with change in mJOA score after surgery.Conclusions:
MRS is a novel, noninvasive imaging modality that provides pertinent information regarding spinal cord cellular and metabolic function. In a cohort of operatively treated CSM patients, the NAA/Cr and Cho/NAA ratios were predictive of neurological outcome, as both were significantly associated with change in mJOA score after surgery.