Like everyone has said they definitely sound like head tremors. I was hysterical when Samson had his first one but lucky for me when I called my vet they knew what I was talking about and said they were head tremors. The vet told me he was fine but to be concerned if it started affecting his entire body or seemed to worsen but it never did. Just ever effects his head like he is shaking his head no, he can give kisses, walk, jump, give me the paw, everything, his head is just shaking. I still scheduled an appointment after the first episode and had a thorough exam done, blood testing, parasite testing, the whole deal but he was perfectly healthy and that put my mind at ease. Now this is a heavily debated subject as to what causes them, from my own personal experiences I don't feel that this is a blood sugar issue, just my opinion though. So now when Samson gets one I just let it run it's course and it always happens for a minute or so then stops.