gms | German Medical Science

Objective: Cervical spondylotic myelopathy (CSM) benefits from timely radiological diagnosis with prompt treatment because surgery performed at early stages was reported to have better outcome. The intention of our study was to investigate the usefulness of Diffusion Tensor Imaging (DTI) for early radiological detection of pathological alterations in cervical myelon in patients without T2 signal hyperintensity but with narrowed cervical spinal canal (SC).

Method: DTI was performed on 18 patients with signs of CSM. Quantitative Fractional Anisotropy (FA) and Apparent Diffusion Coefficient (ADC) maps were generated on axial plane at the most narrowed cervical levels using 1.5-T MRI and compared to non-stenotic levels. We also documented the cervical canal stenosis-grade and the width of the spinal canal in the axial plane.

Results: FA was statistically reduced at the stenotic level compared to pre-stenotic (p<0.001, paired t-test). Our results failed to show statistically significant lower FA at stenotic level in comparison with post-stenotic level (p=0.5). While mean FA at pre-stenotic level was 0.51, which was statistically higher than at stenotic level (0.44), our results failed to show statistically significant increment in ADC values at stenotic level in comparison to non-stenotic levels, most probably suggesting very early stage of degeneration. Over the group of patients, ADC correlated significantly with the width of the spinal canal at the pre-stenotic level (r=0.5, p=0.03), but not at the post-stenotic level (p=0.4).

Conclusions: Our findings suggest that DTI seems to be robust to show alterations at molecular level in the spinal cord before possible pathological T2 signal hyperintensity and marked clinical worsening appears. Therefore, larger and long-term studies should be conducted to further establish the potential of DTI scalar metrics as possible biomarkers in patients with clinical signs of CSM to detect and intervene earlier for a better clinical outcome.