Lady, I just googled this, and I can't tell from first reading if it would have anything to do with me. For one things, I don't think I have any occulusion of jugular veins. Mine are always
very clear. On the other hand, I had a PET scan many many years ago, one of the first, which showed low blood flow to the brain, within the brain, not in the vein leading up to it. I believe the PET scan was pre every dx, and no one dx'd anything from it except Chronic Fatigue, which
was about all anyone could come up with in those days for me....but soon afterwards the
eye problems brought an MS dx (blind spot, double vision, narrowed visual fields). I just don't know if I could have this.

What is more easily clear is that I have Polycythemia Vera, which can cause mini-strokes, and that could account for occasional dimming of eyes, which is helped by the niacin which opens the vessels. I am JAK2 Positive, so that is a definite dx, much easier to get than MS or Porphyria.