When a lesion is “active” it will be a bright spot on your MRI and you could benefit from the massive steroids to end the inflammation. Each lesion can cause issues now and again in the future so it is better to prevent them and that is what the DMTs try to do. The steroids shut down the inflammation quickly but don’t necessarily result in less overall damage – we just feel better quicker.
Hopefully you are with a MS specialty Neuro or watch through as much Dr Boster’s You Tube videos as you can and you will understand things better…he puts it out there in easy to understand videos that are pretty short and digestible. Good luck!