Stroke Risk in Migraine Patients is Increased—Poor Outcomes are Not

Migraine, and in particular, migraine with aura has been shown to be a risk factor for ischemic stroke , a type of stroke caused when a blood vessel that supplies blood to the brain is blocked by a blood clot. In fact, in a recent study researchers looked at the link between migraine and stroke by reviewing 21 earlier studies that included over 600,000 total patients and found a doubling of stroke risk in migraine patients. However, little research has been done on the relationship between migraine with aura and how well patients do after they experience a stroke.

The Women’s Health Study

The Women’s Health Study (WHS) began in 1993 and ultimately included almost 40,000 female health care professionals at least 45 years of age who enrolled and in whom treatments for heart disease and cancer were studied until 2004. At the beginning of the WHS and annually thereafter, participants were sent a questionnaire about their medical history, health habits and other conditions, including migraine. Even after the formal heart disease and cancer trial ended, participants continued to supply information about changes in their health conditions via an annual questionnaire. This pool of information, has allowed researchers to gain new insight into the experiences of 27852 study participants regarding the relationship between migraine and the outcomes some of the participants experienced after suffering a stroke.

Migraine and Stroke History in the Group

Of the 27852 women, 5129 reported some type of migraine history, 3612 had active migraine of which 1435 had migraine with aura. Over the course of 13.5 years of follow up in the study, 398 people reported having TIA’s (transient ischemic attacks or ‘mini strokes’) and 345 reported ischemic strokes. Women who reported migraine with aura had a significantly higher risk of TIA and ischemic stroke compared with women who reported no history of migraine. Additionally, researchers observed no increase or decrease in either of these conditions in women who reported a migraine with no aura or who simply had a past history of migraine.

Stroke Outcomes

Researchers found that even though women in this study who reported they had migraine with aura had an increased risk of TIA or ischemic stroke, they did not necessarily have an increased risk of a poorer outcome once they experienced a stroke. The outcomes were measured by looking at the medical records of people who had experienced a stroke and rating their degree of post stroke impairment according to a 7 point rating scale. For example a score of “0” indicated no impairment at all, a score of “1” no significant disability despite symptoms and so forth. The results indicated that those women who had migraine with aura who suffered a stroke were most likely to have their disability be classified in the lower end of the scoring scale, thereby causing the researchers to conclude that the risk of a poor outcome in people who experience migraine with aura and who have an ischemic stroke is relatively small. While the exact reasons for the better outcomes are not well understood, and until further study is done to identify and confirm possible theories, a focus on stroke prevention by migraine sufferers is critical.