Migraine-Associated Stroke Not Linked to Atherosclerosis
Mechanisms related to migraine-associated ischemic stroke may not be associated with cerebral vascular risk factors.
The theory that increased risk for ischemic stroke associated with migraine may occur through a mechanism of increased atherosclerosis was directly contradicted by the results of a study recently published in Stroke, which showed the prevalence of atherosclerotic plaques in stroke patients with migraine was actually lower than the rate among patients without migraine.1
Investigators from multiple institutions in the Netherlands analyzed data from 656 patients with stroke from the Dutch Acute Stroke Study (DUST), a large prospective multicenter study conducted from May 2009 to August 2013. Fifty-three patients in the cohort had confirmed migraine (29 with aura) with an average of 2 attacks per month, whereas the remaining 603 had no history of migraine. All patients in the DUST cohort had an onset of stroke symptoms less than 9 hours before entry into the study, with National Institutes of Health Stroke Scale scores of ≥2 (≥1 if thrombolysis with recombinant tissue plasminogen activator was needed).
All participants underwent the 5-question Migraine in Stroke Screener on entry, which had a very high negative predictive value (0.99) but showed only moderate positive predictive value of migraine in stroke.2 The patients all underwent computed tomography (CT) evaluations of intra- and extracranial vessel atherosclerosis of both the anterior and posterior circulation.
Intracranial atherosclerosis was lower in patients with migraine, evident in 51% of CTs compared with 74% among patients without migraine (adjusted risk ratio, 0.82; 95% CI, 0.64-1.05). Atherosclerotic changes in the extracranial circulation were also lower among patients with migraine, although to a more moderate degree (62% vs 79%, respectively; adjusted risk ratio, 0.93; 95% CI, 0.77-1.12). Internal carotid artery calcification volumes were similar between groups (23% largest-volume vs 35% medium- and smallest-volume tertiles; adjusted risk ratio, 0.93; 95% CI, 0.57-1.52).
The investigators suggested that because the study was conducted in a stroke population with a high prevalence of risk factors including hyperlipidemia, hypertension, diabetes, and older age that atherosclerotic contributions might be minimized in this population. Still, the evidence from this study argued against atherosclerosis of the large vessels as a mechanism of stroke in people with migraine, which was consistent with previous findings by Kurth et al,3 which showed that migraine was associated with stroke in women who did not have vascular risk factors.
"Our findings suggest that the biological mechanisms by which migraine results in ischemic stroke are not related to macrovascular cerebral atherosclerosis," they reported.
- van Os HJA, Mulder IA, Broersen A, et al. Migraine and cerebrovascular atherosclerosis in patients with ischemic stroke [published online May 19, 2017]. Stroke. doi: 10.1161/STROKEAHA.116.016133
- van der Willik D, Pelzer N, Algra A, Terwindt GM, Wermer MJ. Assessment of migraine history in patients with a transient ischemic attack or stroke; validation of a migraine screener for stroke. Eur Neurol. 2017;77:16-22. doi: 10.1159/000449425
- Kurth T, Schürks M, Logroscino G, Gaziano JM, Buring JE. Migraine, vascular risk, and cardiovascular events in women: prospective cohort study. BMJ. 2008;337:a636. doi: 10.1136/bmj.a636