Migraine with visual auras associated with vision loss is a risk factor for stroke in young women. However, not all types of visual auras predict stroke risk, say researchers with the Stroke Prevention in Young Women study.

Dr. Steven Kittner of the University of Baltimore, Maryland, presented these findings at the American Stroke Association’s International Stroke Conference 2005. Previous findings from the study indicated that any type of visual aura with migraine is a risk factor.

The ongoing study is a population-based trial consisting of 963 women between 15 and 49 years old. The objective of the current analysis was to determine the significance of vision loss versus spots and lines with visual aura and stroke risk in 542 women. The 542 women were all diagnosed with stroke as a result of a blood clot in the brain. A control group consisted of 614 women who were interviewed by random-dialing and matched to the stroke patients according to age, race and geographic region.

The subjects met the definition of having migraine with visual aura if they had ever seen spots, lines or flashing lights during a headache or if they ever had a headache with loss of vision. Subjects needed to have had at least two episodes of headache with aura in the previous year.

Kittner reported that migraine with visual auras associated with vision loss more than doubled the risk of stroke. He hastened to add that “this risk is still relatively low…The absolute level of risk is 1 in 5,000 young women per year with ischemic stroke.”

The Baltimore investigator pointed out that risk of stroke in migraineurs with visual auras and loss of vision can be reduced. Stroke patients in the study tended to be obese, to have high blood pressure, and to be smokers. Weight loss, exercise, smoking cessation, and a discussion of oral contraceptive use is warranted in these women.

“Any person, regardless of age, with new onset of visual symptoms with headache should not assume this is associated with migraine,” Kittner cautioned. These could be symptoms of a mild stroke and should be investigated immediately. He also stressed that the findings are preliminary.