I've been to ERs with headache, nausea, dizzines, had the CT scan showing mild hydrocephalus, which we already know....no change...BUT since the pressure of the hydro is what the real problem is, the only way to check it is the xray to show the approximate rate, then of course, a shunt tap.
So there can be other things going on with the shunt other than placement, fracture, infection, nonfunctional. Don't think I got them all, but should be close. I can tell that the pressure is up when my eyes feel like they are popping out of my head.