This question has haunted migraineurs, clinicians, and researchers for decades: how can such an excruciatingly painful condition not result in some damage to the central nervous system? It appears that some research bolstered by technological advances (MRI, etc.) is shedding some light on this question. In this blog I’ll attempt to condense some of the research and make some sense of this troubling problem.
Please forgive any overly technical terms. There exists controversy as to whether or not the presence of WMAs (White Matter Abnormalities) as detected by an MRI is truly a risk factor for future stroke. To deepen the confusion, it is not clear as to whether the WMAs are caused by vascular disease, or migraine. What was clear is that individuals with migraine are at higher risk of having WMAs. To be exact, it is not certain that increased stroke risk in migraineurs is related to an increase in WMAs. All we can say for certain is migraineurs have an increased likelihood of WMA, and this is a structural change in the brain. Again more research is needed. These WMAs are seen in both older and younger patients.
For many years, a causal relationship between migraines and cardiovascular disease has vexed the medical community, which was mostly concerned with the increased risk of stroke in younger patients. Presently, The American Headache Society recognizes that one third of US stroke victims have a history of migraine and most are females older than 40. Given the large number of migraineurs some overlap is to be expected. A newer study released by the American Heart Association supports this theory that older migraine sufferers are at an enhanced risk for developing silent brain injury. Silent brain injuries also referred to as ischemic silent brain infarctions or silent strokes, are brain injuries that show no symptoms and are presumably caused by a blood clot that blocks blood flow to necessary brain tissue, and result increasing risk for future stroke. What follows is a study on the next logical step, the relationship between stroke and migraine.
One study examined Magnetic Resonance Imaging (MRI) results from a varied group of individuals to scrutinize stroke risk between migraine sufferers their non-migraine counterparts. Here are the demographic results:
104 participants had a history of chronic migraines.
442 participants were negative for a history of migraines.
41% of participants were male.
65% were Hispanic (as Hispanics have an increased risk of stroke).
The average age of all participants was 71 years.
In participants with a history of migraine, silent brain infarctions (which look like lesions, or possibly WMAs) were twice as prevalent (30%). However, there did not appear to be an increase in the volume of small blood vessel abnormalities, which prior studies have connected with migraines.
The realization that older migraine sufferers had twice as many silent brain infarctions (according to the above study) has readers thinking : could preventative treatment for migraine severity and frequency help to decrease the existence of silent brain infarctions and therefore, lower risk of future stroke?
It is estimated that only about 12% of adults with frequent migraines take preventative medication and manage pain once symptoms arise. For chronic migraine syndrome, the FDA has approved one preventative drug, Botox. In addition, recently the Cefaly Headband was approved for preventative effects. I’m sure there will be more in the pipeline once drug companies appreciate the magnitude of the prospective market. Very recently, monoclonal antibodies may be such an example.
Other studies, in particular the Reykjavik Study, the Woman’s Health Initiative Study, and the GEM Study also add to the body of knowledge that proposes migraineurs, particularly with aura have a higher cardiovascular risk than non-migraineurs. However in the same breath the same authors state “Most migraine patients have migraine without aura and are at little or no increased risk of cardiovascular disease. Accordingly, most patients with migraine should be reassured rather than frightened.” What to think?
If you do take the time to read these studies bear in mind the difference between “association” and “cause”. The first means two events co-exist in the same time and place, one does not necessarily “cause” the other. “Cause” is more powerful. It’s like hammering a nail. The hammer “causes” the nail to be driven into the wood. A handsaw may be on the workbench next to the hammer, but that is only “association”. Right now it appears to me there is a lot of “association” going around in the research, and far less “cause” (and effect). However, that does not mean one should not be cautious.In research an identified relationship of association is reason to pursue a causal one if the evidence points in that direction.
It’s important for readers to recognize that further research is necessary to confirm with certainty whether long-term effects exist for chronic migraine sufferers and if so, what the true nature of those effects are. If you are interested in learning more about preventative treatment for migraines, schedule an appointment with your treating physician to discuss available options.
What further steps can you take as a migraine sufferer? Understand that migraine is a complex disease, poorly understood, and may not have the exact same genetic or biochemical causes present in all sufferers. The very best steps you can take are to actively control your cardiovascular risk factors. By this I mean; don’t smoke, if you are diabetic keep your blood sugar well-controlled, birth control pills in younger women may be a culprit, watch your weight, keep your blood pressure within normal limits, and control your cholesterol. Also, if you can tolerate them speak with your physician about strategies to avoid migraines, rather than abort them once you are in their grip.
There is no need to be alarmed. This is an opportunity for dialogue with your physician, examination of your risk factors, the lifestyle changes you can make, and a realistic look at the demographic group you fit in regarding age, type of migraine, and lifestyle. Hope and further research go hand in hand.
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