TY - JOUR T1 - In vivo detection of damage in multiple sclerosis cortex and cortical lesions using NODDI JF - Journal of Neurology, Neurosurgery & Psychiatry JO - J Neurol Neurosurg Psychiatry DO - 10.1136/jnnp-2021-327803 SP - jnnp-2021-327803 AU - Paolo Preziosa AU - Elisabetta Pagani AU - Raffaello Bonacchi AU - Laura Cacciaguerra AU - Andrea Falini AU - Maria A Rocca AU - Massimo Filippi Y1 - 2021/11/11 UR - http://jnnp.bmj.com/content/early/2021/11/18/jnnp-2021-327803.abstract N2 - Objective To characterise in vivo the microstructural abnormalities of multiple sclerosis (MS) normal-appearing (NA) cortex and cortical lesions (CLs) and their relations with clinical phenotypes and disability using neurite orientation dispersion and density imaging (NODDI).Methods One hundred and seventy-two patients with MS (101 relapsing–remitting multiple sclerosis (RRMS), 71 progressive multiple sclerosis (PMS)) and 62 healthy controls (HCs) underwent a brain 3T MRI. Brain cortex and CLs were segmented from three-dimensional T1-weighted and double inversion recovery sequences. Using NODDI on diffusion-weighted sequence, intracellular volume fraction (ICV_f) and Orientation Dispersion Index (ODI) were assessed in NA cortex and CLs with default or optimised parallel diffusivity for the cortex (D//=1.7 or 1.2 µm2/ms, respectively).Results The NA cortex of patients with MS had significantly lower ICV_f versus HCs’ cortex with both D// values (false discovery rate (FDR)-p <0.001). CLs showed significantly decreased ICV_f and ODI versus NA cortex of both HCs and patients with MS with both D// values (FDR-p ≤0.008). Patients with PMS versus RRMS had significantly decreased NA cortex ICV_f and ODI (FDR-p=0.050 and FDR-p=0.032) with only D//=1.7 µm2/ms. No CL microstructural differences were found between MS clinical phenotypes. MS NA cortex ICV_f and ODI were significantly correlated with disease duration, clinical disability, lesion burden and global and regional brain atrophy (r from −0.51 to 0.71, FDR-p from <0.001 to 0.045).Conclusions A significant neurite loss occurs in MS NA cortex. CLs show a further neurite density reduction and a reduced ODI suggesting a simplification of neurite complexity. NODDI is relevant to investigate in vivo the heterogeneous pathology affecting the MS cortex.Data are available upon reasonable request. ER -