Increased Concentrations of Glutamate and Glutamine in Normal-Appearing White Matter of Patients with Multiple Sclerosis and Normal MR Imaging Brain Scans

In Multiple Sclerosis (MS) the relationship between disease process in normal-appearing white matter (NAWM) and the development of white matter lesions is not well understood. In this study we used single voxel proton 'Quantitative Magnetic Resonance Spectroscopy' (qMRS) to characterize the NAWM and thalamus both in atypical 'Clinically Definite MS' (CDMS) patients, MRI(neg) (N = 15) with very few lesions (two or fewer lesions), and in typical CDMS patients, MRI(pos) (N = 20) with lesions, in comparison with healthy control subjects (N = 20). In addition, the metabolite concentrations were also correlated with extent of brain atrophy measured using Brain Parenchymal Fraction (BPF) and severity of the disease measured using 'Multiple Sclerosis Severity Score' (MSSS). Elevated concentrations of glutamate and glutamine (Glx) were observed in both MS groups (MRI(neg) 8.12 mM, p