A follow-up study to the CAMERA-1 (Cerebral Abnormalities in Migraine, an Epidemiological Risk Analysis) trial (2004), CAMERA-2, was performed to evaluate whether men or women with migraine had a higher incidence of brain lesions 9 years after their initial MRI. This follow-up study was published in the Journal of the American Medical Association (2012;308:1889-1897). According to this new study, white matter hyperintensities tend to accumulate over time in patients with migraine. Hyperintensities refers to bright white spots that show up on MRIs that indicate physiological changes in brain structure and in this case white matter (fiber tracts).
It is uncertain as to whether these physiological changes are relevant to current management of migraines.
The CAMERA-1 study (2004) looked at 295 men and women with migraine along with a control group that consisted of 140 age- and sex-matched patients. These patients were asked to do a follow-up scan in 2009. The purpose of the follow-up was to assess whether these individuals had an increase in brain lesions and whether their migraine frequency was linked to progression of these physiological changes or if these physiological changes were linked to any cognitive loss. Out of the 295 migraine patients that participated in the first study, 203 participated in the second along with 83 out of 140 patients in the control group.
The follow-up study found that 112 out of 145 women with migraine had an increase in white matter hyperintensities compared with 33 out of 55 women in the control group, however, the increase in hyperintensities did not effect cognition. No statistical difference was found in other MRI-measured brain parameters. This includes infratentorial (cerebellum) hyperintensities or new posterior blood vessel necrosis. No relationship was found between frequency of migraine and lesion progression. They also reported that there was no link between migraine and progression of any MRI-measured lesions in men.
The video below details the exploration of the brain’s white matter pathways with DTI-Query:
According to Mark C. Kruit, MD, PhD (neuroradiologist and one of the principal investigators on both CAMERA studies) from Leiden University Medical Center in the Netherlands, “The current findings suggest strongly that the [MRI] changes are not likely attributable to migraine attacks, but more likely [attributable] to having ‘the disease’ migraine.” He adds further that the results of this study were of “no clinical consequence.” Nevertheless, there are certain aspects of this study that merit further inspection. Consider a possible relationship between “the functional implications of MRI brain lesions in female patients” and the development of an inadequate supply of blood and ischemic stroke. Other researchers indicate that the small size of the trial make it impossible to conclude anything definitively.
Deborah I. Friedman, MD, MPH (director of Headache and Facial Pain Disorders Program) at the University of Texas Southwestern Medical Center in Dallas, acknowledges that the study had a small population size. She also mentions that there were too few patients taking preventive medications. These two things combined make it difficult to draw any conclusions about whether or not white matter hyperintensities could be minimized with preventive treatment to lower the incidence of migraine occurrence.
Currently, it is the consensus that the CAMERA-2 study results are not overly useful for pain medicine practitioners. This study is not demonstrating that there is an increase in neurological deficits in women who had increased white matter hyperintensities. In fact, the CAMERA-2 study reports no statistical significance between migraine frequency and white matter hyperintensities. Furthermore, this study did not address the issue of the intensity of pain associated with migraine headaches.