gms | German Medical Science

Objective: Degenerative cervical myelopathy (DCM) is the most common cause of chronic spinal cord compression - ultimately leading to severe neurological deficits, if left untreated. We intended to evaluate white matter integrity (Fractional Anisotropy (FA)) at the level of medulla oblongata and metabolic status at the precentral gyrus (Creatinine (Cr); N-acetyl-aspartam (NAA); Choline (Cho); Inositol (Ins)) using magnetic resonance spectroscopy (MRS) in patients with DCM and healthy controls.

Methods: Patients with clinical signs of cervical myelopathy and consistent imaging findings selected to undergo neurosurgical cervical decompression were included in our study. Clinical and MRI-examinations (FA and MRS) were performed preoperatively. Healthy volunteers of similar age served as controls. Clinical scores: mJOA and NDI. MRI was performed at a 3T scanner with a 20 channel head and neck coil utilizing the following sequences for the brain: 3D-T1 (MPRAGE), fMRI with a finger tab paradigm for MRS positioning, single voxel spectroscopy at the precentral gyrus. Sequences of the cervical spine included: axial DWI (RESOLVE with puls-triggering) as well as sagittal T1w, sagittal and axial T2w TSE sequences.

Results: 20 DCM patients were included: 7 female. 18 healthy controls: 9 female. Age and sex showed no statistically significant difference. The groups differ statistically significantly in clinical signs of myelopathy (mJOA, NDI). These findings went along with MRI parameters: changes in white matter tracts at the medulla oblonbgata of DCM patients, FA: 0,645±0,067, healthy controls: 0,698±0,060 (p=0,005). MRS at the precentral gyrus showed significant differences of metabolite concentrations between the groups: Creatinine (Cr) (DCM mean 46,46; controls mean 51,63; (p=0,027)); NAA (DCM mean 93,94; controls 107,24; p=0,048). The following significant negative correlations could be observed: duration of symptoms and Ins and Ins/Cr ratio; ataxia and FA. Positive correlations: ataxia and Cr; T2w signal increase of myelon and NAA, Cr.

Conclusion: FA is significantly lower in patients with DCM, reflecting dearrangement of white matter tracts in the medulla oblongata. Clear differences in metabolite concentrations were observed, which are indicators for functional status/recovery and neural integrity/viability. There were significant correlations between MRS metabolite concentration and clinical symptoms. These non-invasive measures may help determine the optimal time point for surgical treatment.