Demyelination and migraines

I've read things on-line that talk about white-matter changes on MRI that can be related to migraine headaches.  My question is this:  do those white-matter changes represent demyelination or a different process, and if it does, could they then create the kind of symptoms you would see in multiple sclerosis?  Also curious about what hypertension might do...can hypertension cause changes that might not be typically expected (non-ischemic changes and such)?
Thanks in advance,
Karen

[CCF-Neuro-M.D.-JT]

In the setting of migraine headaches as well as hypertension, white matter changes seen on MRI are usually attributed to vascular or blood vessel changes resulting in decreased blood supply and oxygen to very small (and often clinically silent) areas in the white matter of the brain rather than demyelination. Of course, hypertension is well known to be a major risk factor for stroke which would lead to more distinct and clinically correlating lesions on the MRI.  But even if it's just small vessel changes that do not produce a stroke, the changes due to hypertension are ischemic in nature. If the migraine is severe or porlonged, there can even be small areas of swelling in the brain on the side of the headache.  There was one report in the literature I saw from 1992 that looked at 46 migraine patients who had MRIs.  6 of the 46 patients had white matter changes whose exact mechanism were unclear but were attributed to either ischemia or very small areas of demyelination.  These did not produce symptoms of MS.  Hope that helps.

[bflogal]

I became very ill 5 years ago while on vacation, with protracted  and forceful N/V/D over a period of 12 hours. I was seen in an ER where they diagnosed my illness as botulism. In the Spring of 2001, I suddenly felt very odd...my brain felt like it was swelling, I was very dizzy and my BP was 201/104. At the time I was taking indomethacin and a medrol dose pack for a back injury. The symptoms seemed to occur within an hour of my medication dosage. Over the next 4 hours the BP receded. The next day I repeated this same scenario and felt that I might be pre-stroke and went to an OR. They too felt like it was drug related and watched the BP fall over 4 hours. Before I left the ER, they did a CT scan of my head and told me that I had sustained a "bleed" in my brain sometime in the past, most probably during a time when I was doing something very forcefully and for a very long time...they believe it might have been when I had the episode with botulism. It apparently had occurred in a part of the brain that would not have given me any lasting after effects. I am now on Verapamil and wondered if this could occur again, and could I have TIAs without knowing about them?

[CheckingDx]

A related discussion, White Matter Changes/Empty Sella was started.