Disclosure: Question relates to my daughter, who has been tentatively diagnosed with OCHOS, orthostatic cerebral hypoperfusion syndrome. I hope folks won't mind me asking a question for personal reasons. Assuming a reduction in blood flow to the brain of about 25% (average quoted in Peter Novak's research), would that affect the glucose supply to the brain? I know the brain usually extracts about 30-40% of the oxygen from its blood supply, but can "suck out" more if needed. Can it do something similar with glucose? I have tried to research this myself, but didn't get anywhere. Original paper on OCHOS (doesn't go into any detail on possible effects on oxygen or glucose supply): https://pubmed.ncbi.nlm.nih.gov/26909037/
My reason for asking is that since being unwell my daughter has been struggling with uncharacteristic irritable and even angry outbursts that follow a daily pattern and may be connected to meals. For instance, she says she recognised herself in this article: https://www.washingtonpost.com/heal...sion-anger-diagnosis/?itid=ap_sandrag.boodman (Not the confusion or visual problems, just the emotional aspect.) She has had her blood glucose tested in various ways – no abnormalities. It does seem that the bottom end of the normal range correlates with her “afternoon slump”, when her mood and energy levels plummet. So we have been experimenting with the “15-15” rule to see whether it helps, and also trying for meals that won’t cause a glucose spike/dip. She has a simple finger-prick meter but struggles a bit to use it because of cognitive problems. I am trying to help her with it.
You might find some information from this thread helpful - https://www.s4me.info/threads/dumping-syndrome.39486/#post-545623
A complicating factor is that she had her colon removed in her twenties due to ulcerative colitis, and she noticed after the surgery that this altered her perceptions of hunger. A physical example is that she no longer gets borborygmi (growling stomach) when hungry. She does do her best to eat regularly despite this, and lived very well with a j-pouch (internal reconstruction using part of small bowel to compensate for loss of colon) for many years. But now with her fatigue and cognitive problems, it’s not so easy. I am sure the colon and brain and other organs exchange signals, and this will all be missing. But whether this is making her OI/possible low glucose to the brain worse, I don’t know. Her ulcerative colitis and orthostatic intolerance symptoms did start at the same time and both have an autoimmune component, although the UC progressed swiftly and became severe whereas the OI has been insidious. (Of course we only know this with hindsight.) Anyway, just some musings.
@Haveyoutriedyoga, thank you for the link. I asked my daughter and she did consider dumping syndrome a some years ago, but it was before we knew how to research things, or knew about forums such as ths one, so we will look into it again. Thank you for the suggestion.