Article
Degenerative cervical myelopathy – quantitative analysis of MR spectroscopy via segmentation of grey and white matter in the primary motor cortex to evaluate on-going pathomechanisms
Degenerative zervikale Myelopathie – quantitative Analyse von MR-Spektroskopien mittels Segmentation in grauer und weißer Substanz im primären Motorkortex um anhaltende Pathologien zu evaluieren
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Authors
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Christian Blume
- Rheinisch-Westfälische Technische Hochschule Aachen, Klinik für Neurochirurgie, Aachen, Deutschland
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Hans Rainer Clusmann
- Rheinisch-Westfälische Technische Hochschule Aachen, Klinik für Neurochirurgie, Aachen, Deutschland
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Verena Mainz
- Rheinisch-Westfälische Technische Hochschule Aachen, Klinik für Psychiatrie, Aachen, Deutschland
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Hani Ridwan
- Rheinisch-Westfälische Technische Hochschule Aachen, Klinik für Neuroradiologie, Aachen, Deutschland
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Kerstin Jütten
- Rheinisch-Westfälische Technische Hochschule Aachen, Klinik für Neurochirurgie, Aachen, Deutschland
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Christian Andreas Mueller
- Rheinisch-Westfälische Technische Hochschule Aachen, Klinik für Neurochirurgie, Aachen, Deutschland
| Published: | June 26, 2020 |
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Outline
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Objective: The exact pathophysiological mechanisms in the primary motor cortex (PMC) of patients with degenerative cervical myelopathy (DCM) are still unclear. The aim of the present study was to detect pre- and postoperative alterations of crucial neuro-metabolites in the PMC of patients with DCM using MR spectroscopy (MRS). Specifically, and to establish a precise method of measurement, alterations were inspected in grey (GM) and white matter (WM). Respectively, while excluding/controlling for cerebral spinal fluid (CSF) for partial volume effects.
Methods: MR spectroscopy was performed in 38 DCM patients (mean age 61.3±11.4; male n=24 and female n=14) with indication for surgical decompression before and, additionally, in 20 patients six months after surgery. 20 healthy and age matched volunteers served as control group (CG) (mean Age 63.7±6.3; male n=11 and female n=9). The neurological status and clinical scores (mJOA, NDI) of patients and volunteers were collected. MRI was performed at a 3T scanner with following sequences for the brain: 3D-T1, fMRI for finger tab paradigm for spectroscopy voxel positioning at the PMC. MR spectroscopy assessing: Creatinine (Cr), N-acetyl-aspartam (NAA), Choline (Cho), and Inositol (Ins). Spectroscopy voxel was classified into grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF) using Matlab and SPM12. Metabolite concentrations were corrected for CSF-partial volume effects and additionally analysed accounting for GM- respectively WM-fraction.
Results: DCM and controls differed significantly concerning the clinical status (mean mJOA: DCM 11.2±3.2; CG 18±0, p<.001; NDI: DCM 40.7±23; CG 4±6.5, p<.001). Measurements corrected for CSF revealed significant concentrations of NAA between patients and CG (mean NAA DCM: 120.0±23.2; CG 135.7±16.5, p=.012). In the analyses of pre- and postoperative patients, metabolites presented significant differences 6 months postop. especially in the GM of the PMC (mean Cr: preop. 203.3±75 vs. postop. 166.8±52.4, p<.05. mean Ins: preop. 141.1±62.8 vs. postop 114.7±39.9, p<.05. mean Cho: preop. 113.4±43.2 vs. postop. 97.6±31.6, p<.05).
Conclusion: Decreased NAA in the primary motor cortex presents an impairment of neuronal function, mitochondrial dysfunction and neuronal density in DCM patients. Postoperatively, metabolites for reactive gliosis/neuroinflammation (Ins) are decreased. Reduced cellular turnover (Cho) and metabolic activity (Cr) seems to be an on-going pathomechanism in the primary cortex even after decompressive surgery.
