Cervical spinal cord and brain magnetic resonance spectroscopy alterations in normal appearing white matter of multiple sclerosis (MS) patients at 3T

Anatomical MRI findings has limited value in predicting patient clinical status or the future course of the disease. Magnetic resonance spectroscopy (MRS) provides the means of accessing biochemical information from the neural tissue thus holding potential for better characterization of the disease and clinical decision-making. In this study, we examined metabolic alterations in the normal appearing white matter (NAWM) of both the brain (periventricular NAWM) and the cervical spinal cord (SC) at C3/C4 in different subgroups of MS. We measured spectra in 15 healthy controls (HC), 28 relapsing-remitting MS (RRMS) and 5 secondary progressive MS (SPMS) patients. The RRMS group is subdivided into three groups based on whether the expanded disability status scale (EDSS) has decreased (RRMSd), increased (RRMSi) or been stable (RRMSs) within the last 12 months prior to the MRS examination. Concentration differences between HC and the patient groups were observed in SC and B for tNAA/tCho (SC/B:p=[0.003,0.011]) and tCho/Cr (SC/B:p=[0.01,0.006]). Additionally, in brain only, differences were found for tNAA/Cr (p=0.027), mI/Cr (p=0.08), Glu/Cr (p=0.016) and tNAA/mI (p=0.05) ratios. Statistical significant differences (false discovery rate corrected) occur between HC and RRMSi in tNAA/tCho (SC/B: p=[0.003,0.017]) and tCho/Cr (SC/B: p=[0.019,0.007]. HC and RRMSs have a significantly different tNAA/tCho (SC: p=0.003]) and tCho/Cr (SC: p=0.019) ratio. RRMSi and SPMS differ in the brain Glu/Cr ratio (p=0.028) and RRMSi and RRMSs have different brain tCho/Cr ratio (p=0.007). tNAA/tCho of the SC significantly correlates with tNAA/tCho of the brain (p