Before getting out of bed and even before sitting up, I had a strange intense fluttering in my brain (more like shaking) and immediately followed by spinning of the room. I did get up after it passed. Within an hour, this happened three times and each time it was worse. When I tried to walk, my vision started shaking and I couldn t walk straight. I then started to vomit . Through the whole episode there was no head pain, only pressure and interior shaking on left side. What could be wrong?