I Have Been On Naproxen 500 Mg Bid For 2

I have been on naproxen 500 mg bid for 2 years for a back injury. I have had typical stomach ulcer symptoms for the last 3 months with burning in my throat. I was treated with nexium bid for 2 months and symptoms settled down in my stomach and throat. And I stopped taking the naproxen For the last 2 weeks the throat burning has returned occasionally. I had a gastroscopy yesterday and all is normal. And my barium swallow was normal too. They took a biopsy for h pylori. No results yet. What could the throat burning be?