I think I was the one to start this thread several years ago now. I have been reading all the responses ever since looking for a common factor but have yet to seen one. But think we can rule out that it is not caused by medications, trauma, heart issues, infections, gender, age and medical conditions like high blood pressure of diabetes. Some of the replies do vary from only happening during the drifting off to sleep and waking up and being gone as soon as we fully asleep or fully awake. This is the unique symptom we are concerned with. To date I still have vibrations every time I go to sleep but they are very mild compared to when they first started. The fact that I am now not worried they are harmful and ignore them makes them mild. They can be stronger when I am stressed (but that doesn't cause them). So I agree with the post that something physical is triggering vibrations, like a fault in one the phases of sleeping which require rising and falling of so many neuro and chemical pathways. Since in most cases the condition is annoying and not harming, the medical field doesn't have much interest in pursuing. They are more inclined to look at conditions that are harmful to many and also would make them money in drugs to treat it. I am sorry to read that so many people have to take medications for so many health issues and suffer even when trying to get off the medications. We still have a long way to understanding how our bodies function. Keep posting and updating and maybe we will be able to figure it out together.