Abstract #2083

Characterization of Early White Matter Damages in Multiple Sclerosis Patients with a Clinically Isolated Syndrome: A Tract Based Spatial Statistics Study

Salem Hannoun^1,2, Franoise Durand-Dubief,^1,3, Christian Confavreux³, Dominique Sappey-Marinier^1,2

¹CREATIS-LRMN, University of Lyon 1, Lyon, Rhone-Alpes, France; ²CERMEP-Imagerie du Vivant, Bron, Rhone-Alpes, France; ³Neurological Hospital, Lyon, Rhone-Alpes, France

This study aims to characterize early pathological processes occurring in twelve multiple sclerosis (MS) patients with a clinically isolated syndrome (CIS) compared to relapsing remitting (RR) patients and control subjects using tract-based spatial statistics (TBSS). Significant alterations of diffusivity including FA decrease, and axial (a) and radial (r) diffusivities increases, were found in extensive white matter regions of CIS patients, with r being the most affected. If r alterations may reflect the demyelinating processes occurring in MS, a can be more evocative of late appearing axonal damage as confirmed by the increase of a in RR compared to CIS patients.