Where are you doing these sessions and what are the parameters?
The sessions are done in a Macy Pan, at 1.5 Atmospheres. My initial 6 sessions or so were 1 hour long, with 20 min oxygen, 20 min without, then 20 min oxygen, then exit.
More recently I have done 20 min oxygen, 5 without, 20 min oxygen, then 5 without, then 10-20 min oxygen, then exit. So roughly 1 hour sessions consistently, sometimes more.
I was doing the sessions once per day without breaks for the first week, but now I've tapered off and have taken a few days to rest. I am planning to take weekends off moving forwards to allow more time for my body to adjust.
For context, I'm coming off an episode of some kinda major somatic trauma release/adrenal fatigue collapse in February - the medical doctor couldn't tell me what had happened to me after a comprehensive set of blood tests, which came back clear. An acupuncturist I saw said that my kidneys were functioning at something like 30% capacity in February.
I've had the neuro-muscular tremors for a few years now. After the above collapse episode in February, they had stopped completely.
Recently, in June, I completed a one-month NeurOptimal regimen. At the tail end of this, the tremors started occurring again. This was just prior to the HBOT sessions.
I've seen that
@Beorn posted about convulsions that can occur, with the main concern being paralyzed breathing. That's never been an issue for me. There is no pain, I don't lose consciousness, and my breathing is constant for the duration of the shaking - the doctor I spoke with ruled out neurodegenerative disorders after an in-person test. She didn't have any diagnosis to offer.
The tremors tend to occur when I am in a deeply relaxed state, such as while doing breathwork, during NO, during yoga, and now during HBOT. My best guess is that they indicate somatic trauma release as mentioned by Levine and/or nervous system damage because I spent far too many years taking far too many psychedelics.