The researchers recruited 18 patients with RRMS and performed T1 weighted, T2-weighted MRI and 3D proton magnetic resonance spectroscopic imaging (H-MRSI) every 6 months for 3 years. They obtained absolute concentrations of N-acetylaspartate (NAA), choline (Cho), creatine (Cr) and myo-inositol (mI) from all grey matter and white matter in the volume of interest (360cm3).
Results showed that the average white matter Cr, Cho and mI concentrations were 8%, 12% and 11% higher than controls, while their white matter NAA was 6% lower than controls. The reduced NAA reflects axonal impairment, while increased white matter Cr and Cho reflects progressive glial pathology. The diffuse white matter glial abnormalities were larger in magnitude than the axonal abnormalities. The axonal abnormalities showed some recovery, therefore the lower NAA levels may reflect a dysfunction which may abate with treatment. There were no changes detected in the grey matter.
Authors: Kirov II, Tal A, Babb JS
Source: Neurology. 2012 Nov 21. [Epub ahead of print]
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