Oh boy Uppitycats I guess I am in for another haul. What are the MS markers that the neuro looks for in the LP? Every day is kind of different. Some things are better some are worse but never am I normal is that something you deal with? consistent is always the weakness balance and tremors (just to different degrees) does that ever completely go away even for a while?
They are looking for 2 (or more) oligoclonal bands in the spinal fluid -- which will indicate a disorder of the central nervous system
-- not specifically MS. Let's assume for a moment that the doctor discovers those 2 bands in the spinal fluid. He will take that with other
test results (perhaps the lesions seen on an MRI), and clinical signs
(all those things you likely have been tested for in his office -- strength, balance, vision issues, whether there are signs of optic neuritis (an inflammed optic nerve), and any symptoms
you've reported (things like the sensory stuff, the numbness, tingling, fatigue..) -- and if there are enough indicators of MS, he may diagnose your situation as MS.
But again, your situation is complicated by the presence of the brain tumor, and your blood test results which keep indicating an infection somewhere in your body. Many of us with MS have "normal" blood test results, showing no infection processes going on. The unusual test results you report would indicate an infectious process -- which also should show up (but differently -- not with oligoclonal bands, necessarily) in the spinal fluid. So that test really is helpful to diagnose a lot of things.
In my experience with MS (25+ years), I must report that symptoms have never entirely gone away. Things like the sensory stuff -- numbness, tingling, have been there always. My ability to walk has declined to the point that I use a wheelchair full time. I don't experience significant tremors, but there is always a slight shaking of hands and arms. MS is a chronic disease -- lasting a lifetime. While there are periods in some folks experience with it where symptoms fade significantly, there is always the risk of a new flare or exacerbation bringing on increasing symptoms and disability. So there may be some brief periods of an absence or major reduction of symptoms, but the MS isn't cured, hasn't gone, and can continue to do damage to your nervous system even if there are no new outward signs.