International Tennis Hall of Famer Monica Seles says she was diagnosed three years ago with myasthenia gravis -- a neuromuscular autoimmune disease that causes weakness in voluntary muscles. These are obviously symptoms that you can't ignore," Seles said. And it took me quite some time to really absorb it, speak openly about it, because it's a difficult one. "I had to, in tennis terms, I guess, reset -- hard reset -- a few times," Seles said. "I call my first hard reset when I came to the U.S. as a young 13-year-old [from Yugoslavia].