This interesting study used chemical shift imaging (CSI) in 13 people with RRMS, 13 people with PPMS and 13 healthy controls to characterise metabolic changes along the entire cortico-spinal tract (CST) and considered the spatial variation of metabolites.
The RRMS group showed higher CST Cho (choline containing compounds) concentration than controls, and higher CST Ins (myo-Inositol) concentration, which suggests greater inflammation and glial proliferation in the relapsing-remitting than in the primary progressive course. Greater Ins concentration was seen in the RRMS group with greater disability which suggested that gliosis may be relevant to disability. While in the PP group lower Cho and Cr (phosphocreatine) was associated with greater disability, possibly reflecting reduced inflammation and energy metabolism in the progressive stage of the disease.
By considering the spatial variation of metabolite concentrations, they were able to detect a greater increase in Cr concentration in voxels towards the superior portion of the CST as compared to controls, and to show a stronger association between Cho and disability, therefore improving their ability to identify clinically relevant metabolic changes.
Authors: Tur C, Wheeler-Kingshott CA, Altmann DR
Source: Hum Brain Mapp. 2012 Dec 26. doi: 10.1002/hbm.22229. [Epub ahead of print]
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