How long has this been going on?
Also, did you do any other test such as the PH Test, EGD, manometry, etc?
You could be a possible candidate for surgery.
I had a Lap Nissen done on Monday and I believe it stopped my LPR symptoms that I have suffered with for almost a year. I had a burning sensation in my stomach, chest, and throat which the surgeon informed me was probably not acid but more bile and other enzymes that PPI's cannot stop. It's a mechanical problem which surgery can fix. I had every test known down and I had no detection of a hernia. However, the surgeon found a sliding hernia when he performed the lap nissen on me.
I hope you can find a solution to your problem. Let us know.