Also, high ANA is not characteristic of MS, nor is severe joint pain (unless it's secondary to some other MS problem, which is rare). I don't say this never happens, and I'm not a doctor either, so take this with a grain of salt. However, from what I've read, your symptoms point to an inflammatory disease such as lupus. The MRI abnormalities might be from blood pressure.
You really need to confer with your doctor and have more testing. Good luck.
ess
Demylelinating process is listed as a differential diagnosis - an alternative candidate to the more likely 'ischemic changes'. Your history with high blood pressure makes the first cause listed the more likely cause of the foci ('spots') on the MRI.
Demyelinating process means the loss of parts of the myelin sheath which covers the nerves in the central nervous system (brain, spinal cord, and optic nerves). When some of it is lost or damaged, signals can become slowed or misfire leading to symptoms found in several conditions, among them Multiple Sclerosis. https://en.wikipedia.org/wiki/Demyelinating_disease
But don't get too tied up in looking into this until you speak to your doctor about these results. As I said, it's listed as an alternative theory, while the issues with blood pressure are perhaps sufficient to explain your results. (I'm not a medical professional, I hasten to add)