Extensive Brain Pathologic Alterations Detected with 7.0-T MR Spectroscopic Imaging Associated with Disability in Multiple Sclerosis, 2022, Heckova+

Extensive Brain Pathologic Alterations Detected with 7.0-T MR Spectroscopic Imaging Associated with Disability in Multiple Sclerosis
Eva Heckova; Assunta Dal-Bianco; Bernhard Strasser; Gilbert J. Hangel; Alexandra Lipka; Stanislav Motyka; Lukas Hingerl; Paulus S. Rommer; Thomas Berger; Petra Hnilicová; Ema Kantorová; Fritz Leutmezer; Egon Kurča; Stephan Gruber; Siegfried Trattnig; Wolfgang Bogner

Background
MR spectroscopic imaging (MRSI) allows in vivo assessment of brain metabolism and is of special interest in multiple sclerosis (MS), where morphologic MRI cannot depict major parts of disease activity. Purpose To evaluate the ability of 7.0-T MRSI to depict and visualize pathologic alterations in the normal-appearing white matter (NAWM) and cortical gray matter (CGM) in participants with MS and to investigate their relation to disability.

Materials and Methods
Free-induction decay MRSI was performed at 7.0 T. Participants with MS and ageand sex-matched healthy controls were recruited prospectively between January 2016 and December 2017. Metabolic ratios were obtained in white matter lesions, NAWM, and CGM regions. Subgroup analysis for MS-related disability based on Expanded Disability Status Scale (EDSS) scores was performed using analysis of covariance. Partial correlations were applied to explore associations between metabolic ratios and disability.

Results
Sixty-five participants with MS (mean age ± standard deviation, 34 years ± 9; 34 women) and 20 ageand sex-matched healthy controls (mean age, 32 years ± 7; 11 women) were evaluated. Higher signal intensity of myo-inositol (mI) with and without reduced signal intensity of N-acetylaspartate (NAA) was visible on metabolic images in the NAWM of participants with MS. A higher ratio of mI to total creatine (tCr) was observed in the NAWM of the centrum semiovale of all MS subgroups, including participants without disability (marginal mean ± standard error, healthy controls: 0.78 ± 0.04; EDSS 0–1: 0.86 ± 0.03 [P = .02]; EDSS 1.5–3: 0.95 ± 0.04 [P < .001]; EDSS ≥3.5: 0.94 ± 0.04 [P = .001]). A lower ratio of NAA to tCr was found in MS subgroups with disabilities, both in their NAWM (marginal mean ± standard error, healthy controls: 1.46 ± 0.04; EDSS 1.5–3: 1.33 ± 0.03 [P = .03]; EDSS ≥3.5: 1.30 ± 0.04 [P = .01]) and CGM (marginal mean ± standard error, healthy controls: 1.42 ± 0.05; EDSS ≥3.5: 1.23 ± 0.05 [P = .006]). mI/NAA correlated with EDSS (NAWM of centrum semiovale: r = 0.47, P < .001; parietal NAWM: r = 0.43, P = .002; frontal NAWM: r = 0.34, P = .01; frontal CGM: r = 0.37, P = .004).

Conclusion
MR spectroscopic imaging at 7.0 T allowed in vivo visualization of multiple sclerosis pathologic findings not visible at T1 or T2-weighted MRI. Metabolic abnormalities in the normal-appearing white matter and cortical gray matter were associated with disability.

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This study used high field strength MRI to look at the white matter which appears structurally normal. Also the regions adjacent to cortex. 7T magnets are becoming more available to research but not yet in clinical practice.

They looked at patients diagnosed with MS (who may have had structurally apparent lesions as well), with a range of disability from asymptomatic to moderate (EDSS 0-6) — see Expanded Disability Status Scale. Vs HCs.

 

Does this study push back th idea of functinal overlay or would it be swept under the carpet

 

This question was similarly raised here recently https://www.s4me.info/threads/funct...edia-and-discussion.23802/page-15#post-481648

@DigitalDrifter posted a meta-analysis/review published in the journal titled Brain, which includes brain imaging as proof that functional conditions have organic brain pathology.