I have come to believe that much of the breathing instability (ventilatory instability) that I have had while using CPAP stems from an intermittent circulation problem which results in too little blood supplied to the brain stem where the central chemoreceptors are located. I regularly do neck exercise[a] and also many things to reduce inflammation to help with this and have found a lot of relief.
So the blood supply for the “old” brain (brain stem as fed by the basilar artery) comes mostly from the vertebral arteries. The vertebral artery enters the vertebra at C6 and exits from the lateral sides of the atlas (C1) then runs along the spine to enter the skull.
Yes there is “supposed to be” a “backup” supply available from the posterior communicating arteries however in around half of us that supply is deficient or lacking entirely.
I am now remembering all of those “tension headaches” I used to have and remembering the rock hard muscles in my neck that went along with them.
I know that I have severe sleep apnea with extreme hypoxia and that my neck has a large girth for my size. Could this large girth be development from all that stress related neck muscle tensing? Could the neck “grow” in an attempt to save the brain from toxins in the body? I am still trying to understand the large neck girth relationship to sleep apnea.
What if my tendency to process stress by tensing my neck muscles ends up compressing my vertebral arteries? That would appear to explain the headaches of old and why they often went away when someone rubbed my neck.
And perhaps vertebral artery compression explains my tendency to have chronic hyperventilation during the time of year I was robbed stabbed and beaten (traumatic stress). You see many of the central chemoreceptors which monitor the blood gas levels and send signals to the muscles which make me breath are in the “old” brain so if the supply of blood to that part of the brain is pinched off…
And what if arthritis is developing in that part of my neck? Anything causing inflammation in the area would likely also supply fodder to help pinch off the supply of blood through the vertebral arteries if the neck muscles tense I suppose.
As I thought about this I started doing some neck exercises[a] and I very much do hear the kind of snapping and popping I hear in my knees as I move them now.
What I know for sure is that I feel much better after doing the neck exercises. I also find it much easier to control my breathing after doing them.
[a] [update: It is becoming daily for me to spend the first ten minutes on my treadmill two sets of 20 repetitions each of the exercises I describe below with the following modifications – head bob not with the “inch back” except the first set – “circles with the nose” going rapidly to very wide and slow and only about four times in each direction. I repeat this at night. I find I experience much less “snapping and popping” than when I started. (Tue Sep 29 19:42:40 PDT 2015)]
The exercises are very simple:
Sit up straight, with your head above your shoulders, but relaxed and then let your head roll gently forward. Then “bob” the head three times in this position. Then return your head to above the shoulders and let the head roll back all the way and rest in that position for a second. Then back to strait up and move the head back about an inch and repeat. Then move the head back one more inch and repeat. Then start again from the strait up position and repeat the whole thing three times.
Then back to the strait up position and move the head to look left and right slowly as far as you can comfortably go repeating ten times.
Then from the straight up position imagine a rod going straight back through your head entering just below your nose and let the top of your head rock slowly to the left and right as far as you can comfortably go about that axis ten times.
Finally starting from the strait up position make some small clockwise loops with your nose as you move your head as far as it will comfortably go to the right (three to four loops) – reverse direction and make counter clockwise loops all the way to the left – reverse direction and return to looking forward. Repeat with larger slower loops. Repeat with “as large as they can be” very slow gentile loops.
If I have the ability to lay down I do so on my back. I place my palms just above my ears and apply gentile pressure to “lift” my head away from the vertebral stack as I relax my neck. I simply hold this for thirty seconds to perhaps a few minutes. Note that I find this useful by itself if I awaken over breathing while using CPAP (quieting of the “urge to breath too much” is generally noticed within ten seconds).