Dementia Linked to Previous Migraine History

Migraine patients had a higher rate of subsequent dementia than people who did not have a history of migraine, a population-based longitudinal study in Denmark showed.

People who had a hospital diagnosis of migraine in midlife -- at ages 31 to 58 -- had a 50% higher dementia rate after age 60 than people without a migraine diagnosis, reported Sabrina Islamoska, PhD, of the University of Copenhagen, in a virtual presentation at the American Headache Society annual scientific meeting.

Compared with people who did not have a hospital-based migraine diagnosis, dementia rates were doubled in migraine patients with aura. Migraineurs who did not have aura had a nonsignificant 20% higher rate. Dementia rate also was higher for patients who had frequent hospital contacts with migraine.

"Our study is the first national register-based study investigating migraine diagnoses in midlife and dementia risk in later life," Islamoska told MedPage Today.

"The results show that migraine is a risk factor for dementia, especially migraine with aura," she added. "This adds to previous studies supporting stronger vascular mechanisms in migraine with aura."

Identifying midlife risk factors for dementia is important because "it means we can detect earlier those who may be at increased risk," noted Suzanne Tyas, PhD, of the University of Waterloo in Canada, who wasn't involved with the study.

"We may want to screen earlier for signs of cognitive decline in people with a history of migraines," Tyas told MedPage Today.

Last year, Tyas led a study of 679 community-dwelling seniors in Manitoba, Canada, that showed people with a history of migraines were three times more likely to develop any type of dementia and more than four times as likely to develop Alzheimer's disease. These data suggest "we may want to treat more aggressively other risk factors for dementia and Alzheimer's disease in order to reduce risk in people with migraines and increase the likelihood of healthy aging," Tyas observed.

In the Denmark study, Islamoska and collaborators looked at national register data of individuals born from 1935 to 1956 who turned 60 years old before 2017. They matched people with any migraine diagnosis from hospitals since 1988 with people who did not have a documented migraine history, in a 1:5 ratio; 62,578 people overall were included.

The outcome was a dementia diagnosis or redemption of dementia medications after age 60, adjusted for sex, country of origin, marital status, education, other headache diagnoses, and psychiatric and other comorbidities. Median age at migraine diagnosis was 49, and about 70% were women.

A number of potential pathways could explain links between migraine and dementia risk, Islamoska said. "Migraine is associated with allostatic load, cardiovascular, cerebrovascular, and metabolic diseases, and behavioral factors," she stated. "These may lead to brain atrophy, changes in brain networks, lesions, and neurodegeneration. In the long term, these may increase the risk of dementia."

An important limitation of the study is that most migraine cases are treated in primary healthcare in Denmark. This study evaluated only hospital-based migraine diagnoses, which may be more severe.

While the study included people with a validated dementia diagnosis after age 60, "we know that 60% of dementia cases in Denmark remained undiagnosed," Islamoska said. The study also is limited by its young study population, she noted. Age at migraine diagnosis also may not correspond with actual onset and unmeasured confounders may have influenced results.

"This research underlines that future studies investigating the pathophysiology between migraine and dementia are needed to identify preventive measures and examine whether proper prophylactic treatment of migraine can prevent dementia," Islamoska said. "We are now investigating whether there is an association between the treatment effect of migraine medication and later risk of dementia."

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