Migraine and MRI abnormalities
Any physician who sees headache patients and reviews MRI scans knows the problem. The patient has an MRI scan to evaluate some problem—headache, fainting, visual symptoms, off balance. The radiologist notes numerous T2 microvascular lesions and gives a differential diagnosis of: autoimmune disease, hypertension, diabetes mellitus, atherosclerotic heart disease, migraine, or demyelinating disease (i.e. multiple sclerosis “MS”). When the doctor discusses the results with the patient, “MS” is all that the patient hears and focuses on. If the first doctor is a family practice physician or internist, then the patient is shipped off to a neurologist to sort it out.
Since the American Migraine Prevalence and Prevention study[i] noted that 56% of patients have ever received a medical diagnosis of migraine, it’s not surprising that the MRI scan shows lesions due to migraine, but the patient has never been given a diagnosis. In this scenario it is incumbent upon the neurologist to establish a diagnosis, which usually will be migraine with or without aura, and then educate and treat the patient. The lesions are called “spots, white dots, microvascular T2 lesions, and WMAs (white matter abnormalities).” The name I like best is “migraine freckles” because it is gently humorous and nearly everybody has freckles.
Cooney, et al,[ii] writing in Headache in 1996 on “Frequency of Magnetic Resonance Imaging Abnormalities in Patients With Migraine” noted that MRI abnormalities with migraine had been reported to be “12-46%.” For their study a neuroradiologist reviewed retrospectively 185 consecutive MRI scans of patients diagnosed with migraine by a neurologist. They analyzed age, sex, type of migraine, duration of symptoms, and other medical conditions. Their results were that 16% of the scans had focal white matter abnormalities. Among patients less than 50 years old and without hypertension, atherosclerotic cardiovascular disease, diabetes mellitus, autoimmune disorder, or demyelinating disease, only 6% had WMAs. Increased frequency of lesions correlated with age and medical risk factors, but not with sex, type of migraine, or duration of migraine symptoms. Cooney, et al, stated in conclusion:
The observed frequency of MRI abnormalities in our series is lower than has been previously reported. In many cases, these abnormalities may be unrelated to migraine. When such changes are discovered in a patient with migraine, other etiologies should be considered.
Swartz, et al,[iii] wrote in 2004 in Archives of Neurology on “Migraine Is Associated With Magnetic Resonance Imaging White Matter Abnormalities.” They performed a metanalysis of seven studies regarding the relationship between migraine and WMAs. The authors concluded:
…subjects with migraine are at higher risk of having WMAs on magnetic resonance images than those without migraine. This increased risk is present even in younger individuals who do not have co-occurring cerebrovascular disease risk factors. Prospective studies are needed to determine whether the increased risk of stroke in migraine is mediated or foreshadowed by the presence of WMAs.
Toth, et al,[iv] writing in 2007 in Ideggyogy Sz on “The prevalence of white matter abnormalities on magnetic resonance images in migraine,” stated:
The prevalence of WMA was 10.3% among the migraineurs, patients without comorbidities such as hypertension, atherosclerotic heart disease, diabetes mellitus, autoimmune disorder or demyelinating disease and it was 3.1% in the group of controls…without migraine or other disease mentioned above.
The data presented here shows that there is a relationship between migraine and WMA. The association of WMA and the risk of following stroke is not clear. There are well known studies analyzing the prevalence of silent infarction too, but there needs to be a long prospective study to answer this question exactly.
Moschiano, et al,[v] writing in Neurological Sciences in 2007 on “The role of the clinician in interpreting conventional neuroimaging findings in migraine patients” stated:
Changes in cerebral white matter at CT or MRI have been reported in patients with migraine, especially in those with migraine with aura. Similar pictures may be present in asymptomatic subjects, and their nature is not completely understood, but their infarct-like nature is strongly suggested. Clinicians play an important role in the evaluation of those migraine patients in whom these nonspecific abnormalities are present. We suggest ruling out specific syndromes in which migraine attacks are associated with white matter changes, multiple sclerosis and central nervous system vasculitis), as well as evaluating the presence of different vascular risk factors (genetic prothrombotic factors, patent foramen ovale, use of oral contraceptives, etc.). Their possible causative role in MRI lesions and in enhancing the risk of a negative clinical evolution must be considered in each individual case.
Summary of migraine and MRA abnormalities
Reported WMA incidence varies from 6%, 10.3%, 16%, to 12-46% and the lack of consistency likely reflects different epidemiologic technique. The lesions may be seen with diabetes mellitus, hypertensive and atherosclerotic cardiovascular disease, multiple sclerosis, autoimmune illness with CNS vasculitis, CADASIL, and migraine. The lesions are currently considered to be benign but exactly what the prognosis of the lesions means in a patient with migraine is uncertain at the time of this writing and further studies are needed to understand the problem.
[i] Diamond S, Bigal ME, Silberstein S, Loder E, Reed M, Lipton RB. Patterns of diagnosis and acute and preventive treatment for migraine in the United States: results from the American Migraine Prevalence and Prevention study. Headache. 2007;47(3):355-363.
[ii] Cooney BS, Grossman RI, Farber RE, Goin JE, Galetta SL. Frequency of Magnetic Resonance Imaging Abnormalities in Patients With Migraine. Headache: The Journal of Head and Face Pain, 1996; 36(10):616–621.
[iii] Swartz RH, Kern RZ. Migraine Is Associated With Magnetic Resonance Imaging White Matter Abnormalities. Arch Neurol. 2004;61:1366-1368.
[iv] Toth M, Kundra O, Kulin A. The prevalence of white matter abnormalities on magnetic resonance images in migraine. Ideggyogy Sz. 2007;60(5-6):239-244.
[v] Moschiano F, D’Amico D, Di Stefano M, Rocca N, Bussone G. The role of the clinician in interpreting conventional neuroimaging findings in migraine patients. Neurol Sci. 2007;28(Suppl 2):S114-117.