PET scan vs Cerebrospinal fluid (CSF) test

Wow. Take material risk if you want to know the results or pay for a PET yourself. Sounds like Medicare to me. That’s a shame - I’m in exactly the same classification. And I see my neurologist in 3 weeks.

I had a spinal tap decades ago chasing a headache diagnosis. I had a CSF leak afterward with accompanying horrific headache. Flat on my back for a couple Of days after they did a blood patch to seal the leak.

I’m not sure I could muster the courage to take that risk again. I will likely call around to radiology departments and get a cash pay price.

@bryanbay just found this…

Before October 2023, original Medicare coverage for amyloid PET scans (which are not invasive) was limited to once in a lifetime. The only other covered test to measure amyloids in the brain involved an invasive spine puncture. Now, amyloid PET scans can be covered by Medicare, because confirmation of these plaques is required to prescribe new treatments that slow the progression of Alzheimer’s disease.

If you have Medicare Advantage, check your plan to determine if PET scans are covered.

I had CFS test many times. It’s really not that uncomfortable. They do numb it first.

Thank you for sharing this. I did not know CSF leaks can result from the procedure. I'll look further into CSF complications and continue searching for a way to get the PET scan.

@bryanbay Did your physician share the rationale for the CSF test vs. PET scan? What might either of these tests show and how will these guide treatment recommendations?

In the original post Bryan stated … Unfortunately, my insurance covers the CSF but not the PET scan.….

Brian I might ask the physician to push back using Medicare’s new position - namely that knowing the extent of amyloid will shape the decision about when to/whether to begin any of the new meds that are an antibody to the amyloid formation. CSF can say there is amyloid on board but that’s not much better than available blood tests revealing the presence of TAU amyloid. I had that one.

My physician referred me for the PET scan because of results from a Cognitive Assessment. The intent is to see if Alzheimer's can be ruled out. I'm not yet on Medicare because my wife has insurance through her employer. I don't know how the results might be used to guide treatment but do have a follow-up scheduled with my physician.

Ah. Well the new treatment - should you and your Doc decide to take that route, is that now or soon the new requirement will be that amyloid is documented by PET.

I was instructed to take Tylenol before spinal tap. I had a spontaneous CSF leak in 2021 that eventually resolved itself.

The is from NIH “ Amyloid PET and CSF biomarkers can identify early AD with high accuracy. There were no differences between the best CSF and PET measures and no improvement when combining them. Regional PET measures were not better than assessing the global Aβ deposition.” I would guess that the PET is more costly hence pushback from Medicare contractors.