Longitudinal magnetic resonance spectroscopic imaging of primary progressive multiple sclerosis patients treated with glatiramer acetate: Multicenter study

B. R. Sajja, Ponnada A. Narayana, J. S. Wolinsky, C. W. Ahn, William M. Brooks, Corey Ford, Todd Richards, James Bowen, J. William Lindsey, Yvan Boulanger, Pierre Duquette, Douglas L. Arnold