New Clues to Link Between MS Drug Tysabri and Rare Brain Disease Goodman B, WebMD, 25 Mar 2014 Accessed on 1 Apr 2014 from http://www.webmd.com/multiple-sclerosis/news/20140325/new-clues-to-link-between-ms-drug-tysabri-and-rare-brain-disease. CommentRecommendBookmarkWatch