I got my first migraine in high school. A blinding aura exploded in my vision, the entire left side of my body went numb, and I couldn't talk. I was afraid I was having a stroke. It took several years for me to put a name to the headaches. Since then, a migraine has knocked me out for a few hours every few months.
Something changed recently. I am currently recovering from my third migraine in a week and a half. Before this latest string of occurrences, it had been about a month. Before that, three months. I hope this is not the beginning of a trend.
Coincidentally, the most recent Scientific American published
It turns out that in many the pain is preceded not by a decrease in blood flow but by an increase—an increase of about 300 percent. During the headache itself, though, blood flow is not increased; in fact, circulation appears normal or even reduced.
The phases of hyperexcitability followed by inhibition that characterize cortical spreading depression can explain the changes in blood flow that have been documented to occur before migraine pain sets in. When neurons are active and firing, they require a great deal of energy and, thus, blood—just what investigators see during brain scans of patients experiencing aura. But afterward, during inhibition, the quiet neurons need less blood.