I don't get PEM, but both physical and cognitive exertion past 2:30 PM will trigger insomnia partway through the night, which is probably related. Recreational reading doesn't trigger it, but reading/composing here will. Playing a FPS game doesn't trigger it, but a turn-based one (more concentration) does. I realize that I really don't have any idea how much neural processing each of these tasks requires, but they probably use different sections of the brain.
Here's a thought: different cognitive tasks use different parts of the blood vessel network and different parts of the glymphatic network. What if there's an obstruction or other abnormality in the network? I did a quick check to make sure 'glymphatic' meant what I thought, and Google's question/answers correlated fairly strongly with ME issues: lack of exercise, poor sleep, and spinal problems all weaken the 'brain cleaning' function. I'm not jumping on that as the core problem of ME, because I'm not sure that the glymphatic system can clear waste rapidly enough to account for my temporary remissions. Can a dose of T2 or cumin drain the waste over the span of a few minutes? Hmmm, I suppose they could also be countering the effects of the waste products, or overpressure or whatever else could be wrong with the glympatic vessels. Something to think about.
Here's a thought: different cognitive tasks use different parts of the blood vessel network and different parts of the glymphatic network. What if there's an obstruction or other abnormality in the network? I did a quick check to make sure 'glymphatic' meant what I thought, and Google's question/answers correlated fairly strongly with ME issues: lack of exercise, poor sleep, and spinal problems all weaken the 'brain cleaning' function. I'm not jumping on that as the core problem of ME, because I'm not sure that the glymphatic system can clear waste rapidly enough to account for my temporary remissions. Can a dose of T2 or cumin drain the waste over the span of a few minutes? Hmmm, I suppose they could also be countering the effects of the waste products, or overpressure or whatever else could be wrong with the glympatic vessels. Something to think about.