Microstructural MR Imaging of Cortical Lesions in Multiple Sclerosis Phenotypes (S21.001)

Abstract

Objective: We used double inversion recovery (DIR) and diffusion tensor (DT) MRI to quantify tissue damage in cortical lesions (CLs) and the apparently normal cortical gray matter (GM) in patients with MS at different stages of the disease. Background DIR sequences allow the in vivo visualization of a proportion of CLs in MS and their application has demonstrated that CLs occur in all the major disease clinical phenotypes. Design/Methods: Brain DIR, DT MRI and 3D T 1 -weighted scans were acquired from 35 relapsing remitting (RR), 23 secondary progressive (SP), 12 benign (B) MS patients and 41 healthy controls (HC). Diffusivity values in CLs, skeletonised cortical GM, white matter (WM) lesions and normal-appearing (NA) WM were assessed. Results: Compared to HC, MS patients had a significantly lower fractional anisotropy (FA) and higher axial (AD), radial (RD) and mean diffusivity (MD) in the skeletonized cortical GM and NAWM. CLs had higher FA (p=0.02), AD (p=0.01) and MD (p=0.05) vs . HC skeletonized cortical GM, as well as higher FA (p=0.00002) and lower RD (p=0.01) vs . patients9 skeletonized cortical GM. Compared to RRMS, SPMS patients had higher WM lesion volume and more severe damage to the skeletonized cortical GM, NAWM and WM lesions. Damage in the other compartments was similar between SPMS and BMS patients. Compared to SPMS, BMS patients had lower MD, AD and FA of CLs. Damage in the CLs had a high power to discriminate BMS from SPMS (area under the curve: 77-80%), with high specificity (93%), sensitivity (89%) and accuracy (87%). Conclusions: Microstructural diffusivity features of CLs differ from those of WM lesions and are likely to reflect neuronal damage and microglial activation. Their quantification may help in the early identification of RRMS patients at risk of developing a progressive form of disease. Supported by: Partially supported by a grant from FISM/2008/R/13. Disclosure: Dr. Pagani has nothing to disclose. Ms. Rocca has received personal compensation for activities with Bayer Schering Pharma and Biogen Idec as a consultant. Dr. Preziosa has nothing to disclose. Dr. Copetti has nothing to disclose. Dr. Mesaros has received personal compensation for activities with Merck-Serono and Bayer Schering Pharma. Dr. Colombo has nothing to disclose. Dr. Horsfield has received compensation for serving as a Director of Xinapse Systems Ltd.Dr. Horsfield holds stock and/or stock options in Xinapsse Systems Ltd. Dr. Falini has nothing to disclose. Dr. Comi has received personal compensation for activities with Novartis, Teva Neuroscience, Sanofi-Aventis Pharmaceuticals, Inc., Merck Serono, Bayer Schering, and Biogen Dompe. Dr. Lassmann has nothing to disclose. Dr. Filippi has received personal compensation for activities with ECTRIMS, MSIF, MS Ireland, US NMSS, Bayer-Schering, Biogen-Dompe AG, Genmab, Merck Serono, Pepgen Corporation, Teva, and Sanofi-Aventis. Dr. Filippi has received research support from Teva, Bayer-Schering and Genmab.