Headache is a common reason for obtaining imaging of the brain, specifically MRI. The value of MRI in straightforward migraines is limited (if we are being generous). Unfortunately we often end up with some abnormal findings on the MRI that can lead to some more un-necessary testing, or anxiety. One of
the most common things that gets reported are white matter changes. If you had an MRI brain, then you likely read something along these lines in its result:
"scattered white matter disease consistent with small vessel ischemic disease. Other considerations including infections (such as lyme), vasculitis, or demyelinating (such as multiple sclerosis) cannot be excluded."
Sounds scary, right? well, it it can put your mind to ease, let me tell you that this read (in most cases) does not likely apply to you. let me break it down:
What is "white matter"?
Brian tissue is largely divided into two segments; grey matter and white matter. Grey matter has the main body of our neurons, while white matter has the long processes that extent from these neurons. These processes appear white because they are usually covered with fatty layer to make them insulated, and this layer is called "myelin".
What is "white matter disease"?
Well, it is basically anything that can change the appearance of the white matter, usually causing "whiter-than-usual" spots on brain MRI.
Think of white matter as skin and white matter disease as wrinkles. Healthy skin should be without any wrinkles. However, many things can affect the integrity of our skin and make it show wrinkles; such as aging, smoking, sun exposure, oxidants damage...etc.
The same can happen to the white matter, any changes in the white matter's blood perfusion, the myelin sheath, or its level of hydration can make the area wrinkled, and hence brighter on imaging.
The most frequent thing that leads to white matter disease is reduced blood perfusion because of the changes in the very small arteries that bring blood to the white matter.
These small vessel changes are seen universally as we age, but they are also seen more prematurely in hypertension, smoking, diabetes and alike. Hence the name: white matter changes of "small vessel ischemic disease".
However, any inflammatory disease can also affect the myelin and change how this white matter looks, such as seen in infections, multiple sclerosis and alike.
Then, why do I have them if I just have migraines?
The reason why migraine patients have white matter spots is still debated. What we know is that migraine is not just a headache, but it is a condition that has many changes in the blood supply and the electricity of the brain, and it is most likely that these are some of the factors that change the integrity of white matter and hence showing spots.
Are these white spots the same exact one we see with these other diseases?
No, the white matter changes have some differences from one disease to another. The ones that happen as we age are a bit different than the ones that happen in multiple sclerosis, and the latter are a bit different from the ones that happen in migraine.
In general, the white matter changes in migraine represent only very few white spots (as in the picture below), while the ischemic changes or multiple sclerosis tend to be more vast and/or grouped together.
However, because radiologists do not know personally know the patients, and are unfamiliar with their history, they have to make a mention of these diseases to avoid future liability. Hence, this statement of: "scattered white matter disease consistent with small vessel ischemic disease. Other considerations including infections (such as lyme), vasculitis, or demyelinating (such as multiple sclerosis) cannot be excluded." is very common and seen in most MRI reports, yet does not apply to the majority of the patients.
But still, does that mean my brain is having "strokes" or that I will suffer long term consequences from my migraines?
Not to our knowledge. There has not been a connection well-established between these white spots in migraine and the overall outcome. Specifically, these spots did not predict risk of stroke or the risk of developing cognitive changes (such as dementia). More over, treating migraine or not treating it did not matter in preventing or reducing the number of these lesions.
The bottom line; the white matter spots that MRI can see in the brains of migraine patients appear to be benign as of now. If you see a mention of other diseases in the report, it is helpful to discuss them with your neurologists to make sure whether this actually applies to you or not.
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