I had a lumbar puncture in August, as prescribed by the neurologist who was trying to confirm that I had MS. Before having my lumbar puncture, I met with my LLMD for the first time. He said my blood tests that only had two hits on the WB confirmed Lyme, but not according to the guidelines. He asked that since I was already getting the lumbar puncture done, that I get an extra vial of fluid and drop it off at a specialty lab that does Lyme testing.
If you have an LLMD and access to a good lab, then you might want to talk with the LLMD and ask about this option. I am fortunate (or not) that Lyme and Bebasia showed up in my spinal fluid. My doctor was excited because I am his first case to actually have Lyme confirmed in the spinal fluid and mostly that's because most people don't get a lumbar puncture ordered. It's not that it's not in the spinal fluid, it's just not a commonly used procedure, so many never get the fluid tested.