I experienced an extreme headache the morning after the Dolly Parton Stampede (DPS) Show and dinner in Gatlinsburg, TN. I had only one boubon cocktail the evening at the dinner (they now serve booze), and did consider that perhaps the severe headache might be caused by altitutude sickness as we were in the Smokies. In fact, our transportation coach had a photo stop at the highest point of the Smokies (+6000 feet). I have strenuously hiked long distances at +10,000 feet without lack of oxygen symptoms, but was a tourist at about 12,000 feet in Lhasa,Tibet and had morning-after-a-drinking-to-much sickness of a headache or, perhaps because of the altitude. (Headaches at high altitudes are symptoms of death-to-come if not properly cared for. Very serious stuff.) So, my altermative theory is that the excellently-spiced cornish game hen and succulent pork loin at the DPS was "marinated" in MSG. Headache dissipated by the mid-afternoon.