I was diagnosed w/ MS 20 years ago. I've been on Tysabri since it was re-introduced on the market (after being pulled off due to PML). So, I was doing pretty good until I relapsed in 2018. I recovered from that relapse with a bit more brain fog and a weak right side but, I'm surviving. Now, I was just tested (AGAIN) for JCV and it came back POSITIVE for the FIRST time. My neurologist is taking me off Tysabri. I don't know what I'll be on after that as I have an appointment NEXT week to discuss.
I've already done a fair amount of research on PML and I'm glad I did. My chances of getting it are VERY low, even w/ my age (62) and the fact I was on Tysabri for so many years. (These are indicators of who is at higher risk of getting it - age - length of time on Tysabri.) I'm more likely to get behind the wheel of my car and die in a crash than I am of getting PML. As of Dec. 31, 2018 (the latest figures I could find), 804 patients worldwide had experienced PML. Two died from PML-associated complications. Those aren't alarming numbers (unless you're one of the people who died). Plus, most people have the PML virus in their systems. It's just undetected because there is NO REASON to test for it.
Did you JUST start getting headaches or have they been an issue all along? When were you determined to be JC positive? Are you on Tysabri?
No matter what your answers are, you should be talking to your neurologist. Hopefully, you have one that you trust. They will help you through this.