Neon Tetra almost constantly at the top of the tank next to the filter?

The only things i could think of are swim bladder or gill disease. But um it could also just be that something is wrong with his central/peripheral nervous system. If he doesn't die within 2 weeks I would definitely say it's something wrong with the nervous system. Could also be what I call "Shakes & Shimmies", so put in aquarium salt. And increase oxygen levels, and keep ammonia,nitrates and nitrites low!