The head shaking started about 8-9 yrs ago & was minimal (small jerky movements more up or down than side to side & every few hours or so). Over time it gradually got worse; the type hasn't changed but the frequency is now constant. The diziness didn't start until about 1-2 yrs ago. My right ear felt like it clogged & then the next day I put my car in park & my head leaned over so far it almost hit the window; I couldn't stop it. I instantly got nauseous but never vommited. I went to a medical doctor who sent me to an ENT, got tested for hearing (perfect) & vertigo (negative). The only other thing to do was an MRI but I didn't have insurance. At that time the head shaking wasn't very bad so I didn't think to mention it. About 1 month after that visit the head shaking progressively got worse quickly. Now I have to hold my head to keep it from shaking (is worse when I try to keep it from shaking), & I'm now starting to get headaches & cramps in the back of my neck from tensing trying to keep my head from shaking. I finally get insurance in 3 wks & will do everything possible but was hoping you could give me some possible causes.