So I've been having this problem for about a month now. Whenever I sit down, my arms and hands get extremely tingly and it gets very difficult to breathe. I went to my neurologist about 3 weeks ago and they found an enhancing lesion in my spine, to which they treated with 3 days of steroids. The issue got better for a little while, but has resurfaced again. I'm also on Tysabri, which I'm not liking too much right now as it makes me feel awful during the infusion and seems to not be working as well as I had hoped. Has anyone else had problems with tingling when you are sitting down? Is there anything that helps?