The Effect of Smoking on Long-term Gray Matter Atrophy and Clinical Disability in Patients with Relapsing-Remitting Multiple Sclerosis.

Lie IA, Wesnes K, Kvistad SS, Brouwer I, Wergeland S, Holmøy T, Midgard R, Bru A, Edland A, Eikeland R, Gosal S, Harbo HF, Kleveland G, Sørenes YS, Øksendal N, Barkhof F, Vrenken H, Myhr KM, Bø L, Torkildsen Ø.