Sorry to hear that you’re developing new lesions
I think they probably meant lesions in the “deep white matter”. This basically means lesions in the white matter of the brain that is far away from the gray matter of the brain. Hmm. I guess that doesn’t help a whole lot! So, to explain… gray matter is the bit of the brain that does all the encoding, storage, processing, etc. It’s where memories are stored, objects are recognised, etc. White matter is the stuff that enables communication between the different bits of gray matter. It’s like telephone or ethernet cables if you like.
MS attacks both the gray matter and the white matter, but it is in the white matter that lesions are more obvious. A lot of white matter is myelinated - this helps communication to be superfast. MS demyelinates the white matter, causing visible scar/inflammation/damage, i.e. a lesion.
Gray and white matter are generally organised with the gray matter on the outside of the brain, close to the skull, and the white matter further in. Where the white matter touches the gray matter it’s called juxtacortical. Away from there it becomes deep white matter - deeper into the brain.
How to stop the advance?
The obvious one is with DMDs: disease modifying drugs such as interferon and Copaxone. I can’t remember if you are RRMS or progressive MS? If you are RRMS then you could be asking about DMDs. Unfortunately, for some unknown reason, current DMDs don’t work on progressive MS.
Vitamin D3 is also being suggested these days as a way of reducing relapses (and therefore lesions). A lot of us on here take a hefty supplement and increasing numbers of neuros and MS nurses are recommending it.
Alternatives to these are diet (google Swank, Jelinek, Best Bet), HBOT (hyperbaric oxygen treatment; google MS Therapy Centres) and LDN (low dose naltraxone; google ldnresearchtrust).
All of these can be taken at the same time too!
I hope this helps.