I can't answer all of your questions but maybe a few. Yes I have had a spinal tap. Actually I have had 2 but the first one was completely unrelated to MS and well before any problems with MS. My neuro had me get an appointment with the xray department for a radiologist to do it under flouroscopy. That way he could watch it as he put the needle in. I had no trouble at all and had no sedation. But I am an RN and find things like an LP very interesting and I don't think I would have wanted sedation.

Yes, they check for O bands and many other things. MS is usually diagnosed by excluding other problems. There are a lot of opinions about LPs here on this forum, some have horrid reports about them others say it was a 'walk in the park'. Mine is the latter. Big help is that you drink a lot of fluids so your body can replace the spinal fluid that ahs been removed. Also if you do have problems with a spinal headache it is very important to your sanity to let your doctor know right away so that they can help.

I hope this helps. Good luck