This study, while interesting, told neurologists something already known, or at least strongly suspected by most. It does support, however, our thoughts that there is a significant vascular cause behind migraines, and especially some of the asymmetry associated with them. We knew it was true at the microscopic and less-microscopic level, but this little study supported the suspicion at even the larger-vessel suspicion as well.
What is the Circle of Willis? Below is a picture of it by itself and what it looks like perched on the underbelly of the brain. In summary, you have four main arteries coming from the heart to supply the brain. The two in front are the carotid arteries and the two in back are the vertebral arteries. The Circle of Willis is essentially the anatomy of how these "trunks" branch into the various recesses of the brain.
In this picture, the Internal carotid artery on one side is labeled, and the Vertebral arteries are NOT labeled but you can see them at the very bottom, joining together as an upside down "V" to make the labeled Basilar artery.
Now, this study was unique in that it looked at these larger vessels for differences in anatomy between different types of migraine patients. As I was saying before, what neurologists have always known however is that that the tiny branches everywhere from a tenth of mm in size (smaller than this period: . ) to a mm in size (about the width of this n)-- that these billions of blood vessels that imbue every nook & cranny of your brain are also different by design in some manner, and more likely to show some damage at a greater frequency than other people just like you who don't have migraines. There is something different about a migraineur's brain vasculature. That being said, there are numerous studies (especially in the psychology and psychiatric journals) showing that there is no long-term negative cognitive changes (thinking problems) associated with these small vascular changes, and many non-migraineurs ALSO have this same thing to some degree or another but for other reasons.
Anyway, if you have migraines and you have an MRI showing something like "non-specific T2 changes," or "subtle white matter changes consistent with small vessel disease," or the like, you should know it is a relatively common finding, is a relatively underwhelming finding, not associated with any changes in thinking, and that this below is often what it looks like:
The two white spots toward the front on your left (perhaps a subtle third spot just above can also be seen)