Visual Pathway Damage in Multiple Sclerosis at Clinical Onset (P4.177)

Objectives. In order to analyze the relationship between inflammation and neurodegeneration in multiple sclerosis (MS), we investigated the relationship between WM, cortical and retinal damage in the optic pathway in MS at clinical onset. Material and Methods. 50 RRMS at disease onset (mean disease duration of 4.0 ± 3.5 months), 31 healthy controls (HC) for OCT and 28 HC for MRI were studied. MRI examination included cortical thickness, global and optic radiation white matter lesion volume (WMLV), DIR sequences for optic nerve. Global peripapillary retinal nerve fiber layer (g-RNFL) and the 6 RNFL-sectors were analyzed by optic coherence tomography (OCT). Patients were divided in “optic neuritis” (ON+) and “not optic neuritis” (ON-). ON+ were further divided in affected and not affected eyes. Results. ON+ and ON- did not differ for clinical, WM pathology and cortical thickness. ON+ affected eyes presented significant global and temporal RNFL thinning when compared to fellow eyes, ON- and HC. A mild correlation was observed between optic radiation or global WMLV and nasal-fields RNFL. A strong correlation was disclosed between optic radiation or global WMLV and temporal-fields RNFL, especially with optic radiation WMLV (r -0.3, p < 0.01 for TI-RNFL; r -0.2, p < 0.05 for T-RNFL; r -0.3, p < 0.005 for TS-RNFL) and this correlation was stronger when considering only affected eyes (r -0.6 for TI-RNFL; r -0.6 for T-RNFL; r -0.6 for TS-RNFL) or the fellow eyes (r - 0.6 for TI-RNFL; r -0.3 for T-RNFL; r -0.4 for TS-RNFL). No correlation was disclosed between WM pathology and cortical thickness. Conclusions. The correlation between RNFL and WM pathology appear quite different in ON- and ON+ patients. In ON+ the higher correlations with both global and optic radiation WMLV suggest that RNFL thinning is the expression of a more severe and diffuse pathological process. Disclosure: Dr. Puthenparampil has received personal compensation from Novartis, Genzyme Corporation, Biogen Idec, Teva, and Sanofi Aventis. Dr. Federle has nothing to disclose. Dr. Pilotto has nothing to disclose. Dr. Poggiali has nothing to disclose. Dr. Signori has nothing to disclose. Dr. Midena has nothing to disclose. Dr. Sormani has received personal compensation for activities with Novartis, Roche, Genzyme, Merck Serono, TEVA, Synthon, and Biogen Idec as a consultant and speaker. Dr. Paolo Gallo has received personal compensation for activities with Biogen Idec, Novartis, Merck Serono, Bayer Schering and Genzyme as a speaker and consultant.