School of Medicine Publications and Presentations
Document Type
Article
Publication Date
9-2021
Abstract
Highlights
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NAAG likely contributes to the total NAA differences between multiple sclerosis lesion and normal appearing brain tissue.
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myo-Inositol was not shown to be different between chronic AQP4Ab-NMOSD brain lesions and normal appearing brain tissue.
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An optimised MRS methodology is described, using 7T field strength and correcting for tissue T2 water relaxion differences.
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7-tesla MRS profiles of chronic brain lesions and normal appearing white matter are presented for MS and AQP4Ab-NMOSD.
Abstract
Magnetic Resonance Spectroscopy (MRS) allows for the non-invasive quantification of neurochemicals and has the potential to differentiate between the pathologically distinct diseases, multiple sclerosis (MS) and AQP4Ab-positive neuromyelitis optica spectrum disorder (AQP4Ab-NMOSD). In this study we characterised the metabolite profiles of brain lesions in 11 MS and 4 AQP4Ab-NMOSD patients using an optimised MRS methodology at ultra-high field strength (7T) incorporating correction for T2 water relaxation differences between lesioned and normal tissue.
MS metabolite results were in keeping with the existing literature: total N-acetylaspartate (NAA) was lower in lesions compared to normal appearing brain white matter (NAWM) with reciprocal findings for myo-Inositol. An unexpected subtlety revealed by our technique was that total NAA differences were likely driven by NAA-glutamate (NAAG), a ubiquitous CNS molecule with functions quite distinct from NAA though commonly quantified together with NAA in MRS studies as total NAA. Surprisingly, AQP4Ab-NMOSD showed no significant differences for total NAA, NAA, NAAG or myo-Inositol between lesion and NAWM sites, nor were there any differences between MS and AQP4Ab-NMOSD for a priori hypotheses. Post-hoc testing revealed a significant correlation between NAWM Ins:NAA and disability (as measured by EDSS) for disease groups combined, driven by the AP4Ab-NMOSD group.
Utilising an optimised MRS methodology, our study highlights some under-explored subtleties in MRS profiles, such as the absence of myo-Inositol concentration differences in AQP4Ab-NMOSD brain lesions versus NAWM and the potential influence of NAAG differences between lesions and normal appearing white matter in MS.
Recommended Citation
Tackley, G., Kong, Y., Minne, R., Messina, S., Winkler, A., Cavey, A., ... & Emir, U. (2021). An In-vivo 1H-MRS short-echo time technique at 7T: Quantification of metabolites in chronic multiple sclerosis and neuromyelitis optica brain lesions and normal appearing brain tissue. Neuroimage, 238, 118225. https://doi.org/10.1016/j.neuroimage.2021.118225
Publication Title
NeuroImage
DOI
10.1016/j.neuroimage.2021.118225
Academic Level
faculty
Mentor/PI Department
Office of Human Genetics
Comments
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