Abstract #1143

Longitudinal Imaging of Myelin Repair and Axonal Loss in Multiple Sclerosis

Robert J. Fox¹, Jian Lin², Thomas Cronin¹, Xiaofeng Wang³, Ken Sakaie², Mark J. Lowe², Michael D. Phillips²

¹Mellen Center for MS, Cleveland Clinic, Cleveland, OH, USA; ²Radiology, Cleveland Clinic, Cleveland, OH, USA; ³Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, USA

DTI was used to follow areas of focal inflammation (gadolinium-enhancing lesions) and normal-appearing white matter (NAWM) in 19 MS patients followed longitudinally over 1 year after starting highly-effective MS therapy. We observed increased FA in gad lesions, which was driven by a decreased in transverse diffusivity. We also observed decreased FA in NAWM, which was driven by a decrease in longitudinal diffusivity. The results are consistent with short-term remyelination within acute lesions and long-term axonal degeneration in normal appearing white matter. These results also suggest that DTI may provide pathology-specific insights into MS.