Has anyone undergone an MRI due to their migraines and been told they had “white matter hyperintensities” (WMHs) on their radiology report? More of us with chronic migraines seem to have WMHs than don’t. They are small bright “brain lesions” seen on certain types of MRI images called FLAIR images (stands for T2-weighted and Fluid-Attenuated Inversion Recovery Image). Recently a study was published in BMC Neurology with the goal of investigating the prognostic value of WMH’s in migraine patients1. Here is what they found.

BACKGROUND: WMH’s associated with migraine history tend to be punctate (characterized by dots or points) and mild; while those that are seen in cerebrovascular disease and cases of cognitive decline are large and often confluent (merged together). It has been hypothesized in previous work that WMH’s in migraine patients could possibly be caused by platelet aggregation abnormalities (differences in the way some peoples’ blood clots) that can be seen in individuals with migraine. However, this has only been put forth as a hypothesis and has not actually been studied2.

WHAT WERE THEY TRYING TO LEARN?: This study was carried out to discover if the WMH’s in people with migraine are associated with any adverse future outcomes.

WHAT DID THEY DO?: This study enrolled 69 migraine patients (52 females, 17 males who were an average of 34 years old). Five of the 69 patients had chronic migraine, the rest suffered from episodic migraine.

  • Subjects filled out a questionnaire to collect basic demographic and clinical information and underwent an MRI scan
  • Patients were re-contacted 24 months later for a follow-up visit. Only 33 patients completed the entire study as 36 either were not eligible/available for follow-up or were excluded for reasons including: drop-out (7 subjects), and exclusion after undergoing surgery for closure of patent foramen ovale3(5 subjects). Therefore, only 33 patients completed the full study. Also, the majority of the patients who were followed refused to undergo a second MRI.

RESULTS:

  • Disease burden was higher in patients who showed WMH
  • Patients with WMH were significantly older than those without WMH
  • Patients with WMH had experienced migraine longer than those without WMH (however there was also a modest relationship found between age and migraine disease duration. There could be a possible confounding4effect of age in the association between disease duration and WMHs.  
  • 15 patients (45%)were categorized as ‘improved’ during the duration of the study, while 18 patients (55%) were non-improved
    • WMH’s and migraine with aura were significantly more prevalent in the non-improved group
      • Other results found in this study: Disease duration and attack duration were significantly lower in patients who did not experience aura
      • Patients in this study who experienced aura were younger than those who did not

WHAT CAN WE CONCLUDE FROM THIS?

  • The “presence and degree” of WMHs is associated with a worse migraine prognosis AND with older age
  • Duration of migraine disease and age were the only variables correlated with WMH in this study

MY TWO CENTS: This study did not have great follow-up numbers (33/69), but when you’re trying to follow patients for two years, I think sometimes you take what you can get. I found it a bit strange that no one would consent to a second MRI, the study would have been more interesting if they had. Also, since there was no control group for this study, there is no way to comment on the difference between WMH in migraine and in the normal aging process. I also feel it would be helpful to have a study population that included more chronic migraine patients. However, I am happy to see someone looked at WMH in the context of migraine, particularly since they are so prevalent and puzzling. I give it a THUMBS UP.

  1. Xie, Zhang, Huo et. al. Association of white matter hyperintensities with migraine features and prognosis.BMC Neurol. 2018(1) :93.
  2. AE Eggers. Migraine white matter hyperintensities and cerebral microinfarcts are silent cryptogenic strokes and relate to dementia. Medical Hypothesis 102(2017) 1-3.
  3. Patent Foramen Ovale (PFO) is a hole in the heart that fails to close the way it should after birth. Some believe PFO is related to an increased risk of migraine.
  4. A confounding variable is a variable that influences both the cause and effect variable in a study and leads to a spurious (non-causal) relationship