New lesions but no symptoms

I was diagnosed in December 2022 after optic neuritis for the third time in 17 years (July 2005, December 2021 and April 2022). I have never had any other symptoms other than things that could be very easily be due to getting older. Since my MRI in July 2022 until my MRI in December 2022, I have three new lesions...2 x c spine and 1 x brain. What disturbs me is that I don't have any physical symptoms. How am I supposed to know I'm having a relapse if there are no physical symptoms? My last MRI was before I started on treatment, so hopefully that will keep it in check. I'm on tecfidera. My ms nurse is going to speak to my consultant about a repeat MRI before I see him in may to make sure.