Alot of folks get a normal or negative spinal tap unless there is active inflammation going on. if you are not in a flare, or in a peroid of remission then most folks ring up negative.

I was diagnosed without the tap, and the MD told me there was no point in putting me thru it unless I was IN a flare. They use MRI studies now, and symptoms.

The negative tap doesnt mean you have MS and it doesnt mean you dont have MS. it just means you are not inflammed at the moment it was taken. Hang in there.