I have had this a few times in the past few days. I will just be going about my daily routine and I will get this feeling like liquid is trickling down the back of my head (on the inside). Well, I thought it was just a weird headache because I have a had a sinus infection for a couple weeks now with a lot of drainage from my nose and ears. Today I got that feeling again and then suddenly everything went black and i passed out. I went to the ER, but they just said they couldn't find anything and sent me home. Anyone have any idea what this could be?