I think I was one of the first to post about body vibrations when failing asleep and waking up back in August 2022.
It has been very helpful to see all the posts from people with similar symptoms. I think we are all looking to share our information so we might be able to find the common factor(s) that lead to this medical condition. We are talking about feeling vibrations somewhere in our body core (like your cell phone vibrating steadily) that only occurs when we are in the drowsy state between falling asleep and waking up. Also once we wake up they rapidly stop. Although there have been many of you reporting your medical conditions, medications, Covid vaccinations, Covid infections, other infections, and trauma, there are none that are found in everyone affected. I am on no medication, have no medication conditions, exercise daily, ideal weight for my age (74), and have no pain or trauma, Covid vaccinations but no Covid infection that I know of...but still have vibrations. So that to me rules out a lot of variables on what could have happened to cause the vibrations. I do think it is connected to the sympathetic nervous system and is exasperated by stress. My personal theory, after reading as much as I could find about what is happening at the moment we are transitioning between awake and asleep, is that it might be an imbalance in the neuro transmitters that are active during this phase. The neuro transmitter(s) could be too many, too little, or mutated into a a new one. What ever the deviation it seems to be permanent so far. I think vibrations are coming from my diaphragm and that the muscles not making a smooth transition from awake breathing pattern to the relaxed sleep breathing pattern. It also might explain why the only people that have been to get temporary relief were ones that did sleep apnea treatments. The CPAP may have changed the breathing pattern enough that the neurotransmitters behaved differently. Anyway I still have them every night and so far that don't seem to be harmful but very annoying sometimes. The medical profession probably not interested since they number of people affected is small and so not enough money to be made researching it so far. Happy to hear any feed back from you and best of luck with those of you with this and/or other medical issues.