Alterations of Microstructure and Sodium Homeostasis in Fast Amyotrophic Lateral Sclerosis Progressors: A Brain DTI and Sodium MRI Study

M.M. El Mendili (1, 2) , A.-M. Grapperon (1, 2, 3) , R. Dintrich (1, 2, 3) , J.-P Stellmann (1, 2) , J.-P. Ranjeva (1, 2) , M. Guye (1, 2) , A. Verschueren (1, 2, 3) , S. Attarian (3) , W. Zaaraoui (1, 2)

1 CRMBM - Centre de résonance magnétique biologique et médicale
2 CEMEREM - Centre d'Exploration Métabolique par Résonance Magnétique [Marseille]
3 Timone Hospital, Referral Centre for Neuromuscular Diseases and ALS, AP-HM, Marseille, France

BACKGROUND AND PURPOSE While conventional MRI has limited value in amyotrophic lateral sclerosis (ALS), non-conventional MRI has shown alterations of microstructure using diffusion MRI and recently sodium homeostasis with sodium MRI. We aimed to investigate the topography of brain regions showing combined microstructural and sodium homeostasis alterations in ALS subgroups according to their disease progression rates. MATERIALS AND METHODS Twenty-nine patients with ALS and 24 age-matched healthy controls (HC) were recruited. Clinical assessments included disease duration and the revised ALS functional rating scale (ALSFRS-R). Patients were clinically differentiated into fast (n=13) and slow (n=16) progressors according to their ALFSRS-R progression rate. 3T MRI brain protocol included: (1) 1 H T1-weighted and diffusion sequence; (2) 23 Na density-adapted radial sequence. Quantitative maps of diffusion with fraction anisotropy (FA), mean diffusivity (MD) and total sodium concentration (TSC) were measured. The topography of diffusion and sodium abnormalities were assessed by voxel-wise analyses. RESULTS ALS patients showed significantly higher TSC and lower FA, alongside higher TSC and higher MD, compared to HC, primarily within the corticospinal tracts (CSTs), the corona radiata and the body and genu of the corpus callosum. Fast progressors showed wider spread abnormalities mainly in frontal areas. In slow progressors, only FA measures showed abnormalities when compared to HC, localized in focal regions of the CSTs, the body of corpus callosum, the corona radiata and the thalamic radiation. CONCLUSION The present study evidenced widespread combined microstructural and sodium homeostasis brain alterations in fast ALS progressors.

Domains: Life Sciences [q-bio]; Human health and pathology; Life Sciences [q-bio]; Bioengineering

M.M. El Mendili, A.-M. Grapperon, R. Dintrich, J.-P Stellmann, J.-P. Ranjeva, et al.. Alterations of Microstructure and Sodium Homeostasis in Fast Amyotrophic Lateral Sclerosis Progressors: A Brain DTI and Sodium MRI Study. American Journal of Neuroradiology, 2022, 43 (7), pp.984-990. ⟨10.3174/ajnr.A7559⟩. ⟨hal-03772234⟩