Cerebral aneurysms is a a group of brain dysfunction related to disease of the blood vessels supplying the brain in which weakness in the wall of a cerebral artery or vein causes a localized dilation or balooning of the blood vessel.

According to recent study results, frequent fluctuations of estrogen during normal menstruation and severe decrease in this hormone occurring at menopause could be linked to the development of aneurysms.

The results of this retrospective, case-controlled study were presented during the Society of Neurointerventional Surgery 7th Annual Meeting.

The lead of study author, Michael Chen, MD, an assistant professor of neurology, neurosurgery, and radiology at Rush University in Chicago, Illinois, said that their findings results support the hypothesis that physiologic decreases in estrogen may explain why cerebral aneurysms occur more frequently in women, particularly postmenopausal women.

She said, “Perhaps this is an important mechanism that contributes to the formation, growth, and rupture of aneurysms.”

According to her, future research should investigate the possible protective role of pharmacologic estrogen in women who are at risk for cerebral aneurysms.
She said, “We might consider putting women with an unruptured aneurysms on some sort of estrogen modifying agent, particularly at menopause.”
She added, “If hormone replacement could sort of mitigate the severe drop in estrogen levels, it may be protective.”

The study was initiated because 2 large brain aneurysms trials – the International Subarachnoid Aneurysms trial and the International Study of Unruptured Intercranial Aneurysms – had found that 70% of aneurysms occurred in postmenopausal women.

During several months, trained healthcare workers interviewed 60 of Dr. Chen’s female patients who had either a ruptured (35%) or unruptured (65%) cerebral aneurysms.
They asked these patients about their age of menarche, parity, age at birth of first child, age at menopause, and use of an oral contraceptives (OCs) and hormone therapy (HT).

The researchers also accessed data on 4682 women from across the United States who had been similarly interviewed for another study that investigated the link between taking additional hormones and the development of breast cancer.
She said, for each aneurysms case, they randomly selected 7 controls matched for age and education level; the final control group was a representative sample of 420 women.

The study subjects ranged in age from 31 to 80 years (median age for both group was 53 years). Mean body mas index was 27.1 for women in the case group and 25.2 for control subjects. The mean age of menstrual onset was 13 years for both groups. About 10% of cases and 11% of the control group had their first pregnancy at older than 30 years.

In the study results showed that although 6 of the aneurysms group use OCs, the rate was 77.6% among controls. The rate of HT use was 23.7% for the aneurysms group and 44.8% for the control group.
Dr. Chen point out that the differences were statistically significant for both the rated of OC and HT.

The average duration of OC use was 2.6 years for the case group and 5.2 years for the control group.
Again, this differences was statistically significant.

Dr. Chen said, “Women in the control group have a higher rate of exogenous estrogen agent use, which may be mitigating or attenuating either severe drops or fluctuations of estrogen, and this may actually be protective.”

According to Dr. Chen, this findings are important because unruptured aneurysms are increasingly being discovered by chance through magnetic resonance images and computed tomographic scans performed for other reasons. There are currently few treatment choices for these aneurysms.
She said, “Our management options outside of surgery are very limited; all we can recommend to our patients is to stop smoking and make sure their blood pressure is under control.”

She added that in future, this advice may include adding hormones, but first more research is needed.
She said, “This is just preliminary; we’re more at the stage of trying to understand the disease process.”
She added, “I don’t think we’re anywhere near making any kind of recommendation.”