multiple sclerosis
"I've used Tysabri for past couple years. Prior to Tysabri, I used couple other drugs but nothing worked as well as Tysabri. My wish would be to take it every 21 days instead of 28 days. The 4-5 days before infusion time can be very painful with head & body aches accompanied by brain fog 
I don't understand the risks for a 21 day infusion, but I'm willing to learn"