My first scan showed 'several' of them and the Neuro mentioned Migraines, along with the radiologist who read the scan. As stated above, they are often see in migraine patients. Just don't let them try to turn you around and now say you don't have CH, but Migraine. It also shows with CH and that too is stated above.
In 15 years, I have had 3 scans. The white matter Flairs or whatever they are called have remained the same over time. Even with my dog knocking me out!!
Your Neuro will be able to explain it better. I researched my behind off and scared myself silly since they said 'mini-strokes' at one point. There was a caveat there though, as in 'might be'. I have had no issues to date and still function as I always did, so I don't think that I am stroking out. With the consistency of the scans, my neuro does not think I am losing it either.
I suspect that CHers are prone to them, just as Migraineurs are. They just have not studied that yet.