Hi, I just read a post about dizziness from April 2011 that matches mine perfectly. It comes on at the same time of year (usually fall) and goes away in April the next spring. I've seen two ENT's, had an MRI and saw a neurologist, went to a physical therapist, had bloodwork done, my thyroid checked and just had allergy testing done. All came back fine.... nothing has been found that could cause this. I usually get nauseated when this happens, it feels just like motion sickness rather than vertigo. Alot of the time, it seems eating triggers it, but sometimes it hits when I haven't eaten a thing. It doesn't matter where I am when it hits... home or away. I don't know where else to turn but it's making my life miserable. I can barely eat because of the nausea. It started 4 years ago. I'm female, 56 years.