Good question! I'm curious as well. I think it's very interesting to hear the various LP opening pressures. I myself have only ever had one LP, so I can only presume that my opening pressure would be in a normal range now.

Did you by any chance feel any better during the 12 reading versus the 20 reading?

I do know that you can get different readings on your pressure. depending on the time of the day, if you ate or if you are dehydrated which I assumed you were since you had your LP's under fluro and at my hospital, even though I was not sedated, they still had me not eat or drink 6 hours prior to the procedure since they had put an IV in me in case I had a reaction to the dye. Even medications can affect your opening pressure.
I was just curious why you had an LP done even though you have a shunt. Are you having high pressure symptoms? Do they think your shunt is not working? Sorry, I can't remember if you have an adjustable shunt or not.
I hope all is well, you are in my Angel prayers, Hugs, Jazzy

Thanks for the replies!

A little background, after a scary couple of days of no vision the drs decided it would be best to put an lp (non-adjustable) shunt in. Amazingly, I had about six weeks of perfect vision, NO head pain or other symptoms and was doing wonderful. Then it was like a whammo, and all the symptoms came back, plus a few.

Since then I have had a scan that showed all was ok with my shunt, no blockage or anything. And the two LPs have been "normal." They have changed my meds around, and continue to do so. At this point I basically am throwing my hands in the air saying I just don't know...

hey Kristena

Sophiasmom managed to be in a position to measure the increase in her ICP in reaction to chemical sensitivity and increase in symptoms. she had just had an LP when she was exposed to some chemicals and got a bad reaction and was then able to get them to do another LP to measure the increase in pressure. For her, in that circumstance her pressure increased by a few points (i cant remember the exact amount without looking for the thread but i think i was about 3)

If you think 12 might be a normal for you with your shunt and the pressure is now 20, (to me plus or minus 3 feels reasonable) then i think that your pressure is up. if your normal had been 20 before and you had added 8 onto that and were now reading 28, we wouldnt be having this conversation they would be taking definite action because you had passed the magic 25 again - plus or minus what wouldnt even come into it.

i would say bottom line you felt good at 12, you feel rubbish at 20, being at 12 is better for you. I dont know about shunts - the shunt isnt programmable so just because its working fine, is it definitely draining enough? maybe you do need meds to keep the pressure down on top of the shunt? dont know but I would keep asking questions of them.

i hope it all settles down soon!

Thank you for explaining Kristena, sorry I couldn't recall about your shunt. I would say that if your op is now 20 it sounds like your shunt is not draining enough CSF. The first LP shunt I had the same thing happened to me so then the NS went in and attached another tube to my existing LP shunt (it wasn't programmable--he didn't agree with doing programmable LP shunts) but unfort. it made me over shunt. I then had to find a NS who did do programmable LP shunts, but he did so only after I brought him in research that showed it was possible to do and then I was able to go back to work for 2 years before I started having other shunt problems.
I hope your Dr's are able to figure out how to help you get back to feeling like you did those first 6 weeks!

Hugs, Jazzy