I'm not a doctor so can't know exactly what is going on in your particular case. However, I will share that I've experienced a strange dizziness or sense of disorientation when I would move my eyes up and down from the music deck on the piano to the keyboard. It turns out that I had developed nystagmus which was only happened if it were triggered by something.
It would be good to mention this to your neurologist at your next visit. If you also think that a relapse is developing, then please do call your doctor sooner rather than later.
Thank you, Lisa! I will definitely mention it. And I think sooner rather than later.