Page 16 - Migraine, the heart and the brain

Chapter 1
Supratentorial deep white matter hyperintensities
White matter hyperintensities have been associated with migraine in several studies. A meta-analysis on data from case-control studies, in which patients with concomitant cardiovascular diseases had been excluded, indicated a fourfold increased risk of white matter abnormalities (periventricular and deep localization taken together) for migraine patients compared with controls.17 The CAMERA-I study investigated white matter hyperintensities in migraine patients and controls and showed that women with migraine were two times more likely to have a high load of deep white matter hyperintensities (OR 2.1, 95% CI 1.0-4.1) independent of migraine subtype.18 The risk was higher in those with higher attack frequency: in those with ≥1 attack/ per month (OR 2.6; 95% CI 1.2-5.7). Several years later, the Vascular Aging study con rmed this higher prevalence by indicating that migraineurs with aura more frequently had a high volume load of deep white matter hyperintensities (OR 12.4, 95% CI 1.6-99.4). The con dence interval however was wide, limiting the accuracy of the point estimate of this nding.23
Infratentorial hyperintense lesions
Infratentorial hyperintense lesions are high-signal areas found on T2-weighted brain MR scans in infratentorial brain structures (cerebellum and brainstem), but are not real parenchymal defects (so not infarcts). Only few studies have been reporting on infratentorial hyperintense lesions, therefore etiology and consequences of these lesions are uncertain. Both microvascular ischemic damage 24-25 and edema26 have been suggested as an explanation of these lesions. The increased prevalence of infratentorial hyperintense lesions among patients with atherosclerosis,26 hypertension,27 diabetes mellitus,28 chronic kidney disease,28 cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)29 and vascular dementia24 all suggests that small vessel disease lies at the origin of infratentorial hyperintense lesions.
In the CAMERA-I study, infratentorial hyperintense lesions were identi ed in 13/295 (4.4%) subjects with migraine and in 1/140 (0.7%) controls (p=0.04). The majority of the cases (n=12) showed hyperintensities (mostly bilateral) in the pontine region of the brainstem.30 Subjects with infratentorial hyperintense lesions more often also had supratentorial white matter lesions (p<0.05). Migraine type, attack frequency, age at onset, or treatment status did not differ between migraineurs with and without infratentorial hyperintense lesions.
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