With problems like global warming, terrorism, the growing divide between the rich and poor, floods, drought, the Euro zone crisis and the US debt, and that's just off the top of my head, is it any wonder that the number of headaches are increasing? The world is experiencing an unprecedented numbers of headaches and it can only continue to rise.
You made a good choice with your migraine hub and I suspect that it will be a gold mine for you in the future. Come to think of it, I probably should come up with a few headache hubs myself. :)