This finding was publicized by the National Headache Foundation so I followed the link to the article. This appears to have been performed in as rigorous a manner as anyone could hope for.
However, this association, as rigorous as it is, has yet to be tested from the standpoint of causation. It is not clear to me how one would actually test a causal relationship between CoW variants and migraine.
I remain skeptical that children and young people with CoW variants have hemodynamically significant changes in blood flow. In older people with CoW variants and cerebrovascular disease the variants would place them at higher risk of large vessel disease having ischemic events - this is not much in question - but the natural history of migraine is generally to get better, not worse.
