Suggest Treatment For Lesions In Brain Causing Memory Loss

I have been going thru a series of test for MS and I got a spinal tap done everything came back normal, but the Myelin Basic Protein, CSF... I have lesions on my brain, memory loss, pins n neddles in my wrist to my fingures and they go dumb, It also happens in my feet, fatigue etc.. I have a lot of signs of ms but all my doctor is want to do another mri in 3 months, what else can I do to get to the bottom line of this?