rjmlr
It's interesting. I tend to have mostly physical symptoms, but over the last year, the cognitive have worsened a bit. My period of cognitive symptoms is between day 2 and day 4 (inclusive) more or less. And it can be extensive enough that a couple of times I've even had depressive sessions for the first time in my life.
But, about 2 wks ago, I had a cold that went into my ears and sinuses, out of POIS. But it felt just like brain fog. It produced ringing, lower hearing capability, a little dizziness and pressure in the head and sinuses.
With that I realized how inflamation can cause cognitive type symptoms.
It's dificult to relate inflamation to brain-fog, a cognitive issue doesn't feel physical at all.
But pinched nerves (optic and auditory) in combination with sinus swelling and inner-ear interference could well be responsible for muchof our cognitive issues.
Not to mention the serotinin and dopamine imbalance that it can cause.
It's really a bummer.......