Summary: A new study published in Brain reports an increased risk of stroke in those who suffer from migraines with aura, but found no evidence of heightened stroke risk for people who suffered from migraines alone.
Source: Karolinska Institute.
People who suffer migraine with aura have a higher risk of stroke, a twin study with 12-year follow-up shows. The findings are published in the journal Brain. The study also found that the risk is lower than previously demonstrated and possibly related to familial factors.
Between 11 and 13 per cent of the population suffer migraines. The condition, which is up to three times more common in women, often debuts in adolescence or early adulthood. Sufferers have recurrent headaches combined with symptoms such as nausea, vomiting or hypersensitivity to light and sound. For one in three sufferers, the headaches start with an aura of neurological symptoms, leading to the migraine classification “with/without aura”. Repeated studies, conducted over the past 30 years or more, have shown that migraine – particularly with aura – increases the risk of stroke. Gender (being female), young age (under 45), smoking and contraceptive pills have also been linked to a higher risk of stroke in migraine patients.
Studied 53,000 twins
Using the Swedish Twin Registry, the researchers looked at over 53,000 twins over a twelve-year period, 16.2 per cent of whom had any form of migraine, and 6.7 migraine with aura. During the follow-up time, 1,297 of the 53,000 twins had a stroke. On examining the link between this and migraines, they found that the data corroborated with earlier studies, although with a lower general risk.
“Our results showed no increase in stroke risk for individuals with migraine without aura, and a somewhat higher risk in twins with migraine with aura, even though this risk was lower than previously demonstrated,” says Maria Lantz, postdoc at Karolinska Institutet’s Department of Clinical Neuroscience.
Familial factors could play a role
The results also remained largely unchanged when the researchers controlled for other risk factors, such as smoking and high blood pressure.
“Further analyses of twin pairs indicate that familial factors, such as heredity and childhood environment, can exacerbate the risk,” says Dr Lantz.
The results of the study provide valuable clinical information both for sufferers of migraine without aura, where there is no observable increase in risk, and for sufferers of migraine with aura, where the risk of stroke is lower than previously demonstrated.
Funding: The study was financed by Stockholm County Council through the ALF scheme and the Swedish Migraine Society.
Source: Karolinska Institute
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Original Research: Abstract for “Migraine and risk of stroke: a national population-based twin study” by Maria Lantz, Johanna Sieurin, Arvid Sjölander, Elisabet Waldenlind, Christina Sjöstrand, and Karin Wirdefeldt in Brain. Published online September 26 2017 doi:10.1093/brain/awx223
[cbtabs][cbtab title=”MLA”]Karolinska Institute “Migraine With Aura May Increase Stroke Risk.” NeuroscienceNews. NeuroscienceNews, 27 September 2017.
<https://neurosciencenews.com/stroke-migraine-aura-7592/>.[/cbtab][cbtab title=”APA”]Karolinska Institute (2017, September 27). Migraine With Aura May Increase Stroke Risk. NeuroscienceNews. Retrieved September 27, 2017 from https://neurosciencenews.com/stroke-migraine-aura-7592/[/cbtab][cbtab title=”Chicago”]Karolinska Institute “Migraine With Aura May Increase Stroke Risk.” https://neurosciencenews.com/stroke-migraine-aura-7592/ (accessed September 27, 2017).[/cbtab][/cbtabs]
Abstract
Migraine and risk of stroke: a national population-based twin study
Numerous studies have indicated an increased risk for stroke in patients with migraine, especially migraine with aura; however, many studies used self-reported migraine and only a few controlled for familial factors. We aimed to investigate migraine as a risk factor for stroke in a Swedish population-based twin cohort, and whether familial factors contribute to an increased risk. The study population included twins without prior cerebrovascular disease who answered a headache questionnaire during 1998 and 2002 for twins born 1935–58 and during 2005–06 for twins born between 1959 and 1985. Migraine with and without aura and probable migraine was defined by an algorithm mapping on to clinical diagnostic criteria according to the International Classification of Headache Disorders. Stroke diagnoses were obtained from the national patient and cause of death registers. Twins were followed longitudinally, by linkage of national registers, from date of interview until date of first stroke, death, or end of study on 31 Dec 2014. In total, 8635 twins had any migraineous headache, whereof 3553 had migraine with aura and 5082 had non-aura migraineous headache (including migraine without aura and probable migraine), and 44 769 twins had no migraine. During a mean follow-up time of 11.9 years we observed 1297 incident cases of stroke. The Cox proportional hazards model with attained age as underlying time scale was used to estimate hazard ratios with 95% confidence intervals for stroke including ischaemic and haemorrhagic subtypes related to migraine with aura, non-aura migraineous headache, and any migraineous headache. Analyses were adjusted for gender and cardiovascular risk factors. Where appropriate; within-pair analyses were performed to control for confounding by familial factors. The age- and gender-adjusted hazard ratio for stroke related to migraine with aura was 1.27 (95% confidence interval 1.00–1.62), P = 0.05, and 1.07 (95% confidence interval 0.91–1.26), P = 0.39 related to any migraineous headache. Multivariable adjusted analyses showed similar results. When stratified by gender and attained age of ≤50 or >50 years, the estimated hazard ratio for stroke was higher in twins younger than 50 years and in females; however, non-significant. In the within-pair analysis, the hazard ratio for stroke related to migraine with aura was attenuated [hazard ratio 1.09 (95% confidence interval 0.81–1.46), P = 0.59]. In conclusion, we observed no increased stroke risk related to migraine overall but there was a modestly increased risk for stroke related to migraine with aura, and within-pair analyses suggested that familial factors might contribute to this association.
“Migraine and risk of stroke: a national population-based twin study” by Maria Lantz, Johanna Sieurin, Arvid Sjölander, Elisabet Waldenlind, Christina Sjöstrand, and Karin Wirdefeldt in Brain. Published online September 26 2017 doi:10.1093/brain/awx223
