Screening reveals a surprisingly high prevalence of intracranial aneurysms in women who smoke

Unruptured intracranial aneurysms (UIAs) are usually asymptomatic, but if an aneurysm ruptures, blood leaks into the space around the brain, causing a subarachnoid hemorrhage (SAH). SAH is a type of stroke and a leading cause of serious disability and death among the working-age population. The risk of developing SAH is particularly high in postmenopausal female smokers.

Finnish biobanks are a rich source of high-quality data from cohort and population studies, which made it possible to team up with the Finnish Institute for Health and Welfare (THL) Biobank and send out targeted invitations to female smokers aged between 50 and 60 years in southern Finland. Of the individuals contacted through the THL Biobank, 50 returned voluntary consent forms to undergo computed tomography angiography (CTA) analysis as part of this globally groundbreaking UIA screening study of the SAH risk group, i.e. postmenopausal female smokers. A total of 43 female smokers ultimately underwent CTA analysis, of whom five were found to have UIAs. The figure is extraordinarily high, as it suggests an UIA prevalence rate of more than 10% in women who are long-time smokers. The prevalence of UIAs is 2% in the general population.

“The prevalence of intracranial aneurysms appears to be remarkably high in post-middle-aged women who have smoked for a long time. This was a small pilot study, but the results are striking and worrying. The good news is that most of the UIAs that were detected were still small and therefore likely to not require surgical or endovascular treatments but respond well to preventive actions such as smoking cessation and CTA follow-ups,” says Principal Investigator, Neurosurgeon Justiina Huhtakangas from HUS Neurocenter and University of Helsinki.

The research team believes its findings to be significant, if they can be confirmed by a larger screening study.

“We have recently discovered that a (subarachnoid) brain hemorrhage resulting from a ruptured aneurysm is the twelfth most common cause of death and the most common type of fatal stroke in middle-aged women. However, further investigation is needed to confirm the screening finding and, above all, to demonstrate that screening for unruptured intracranial aneurysms leads to improved health in women in the long term,” says Miikka Korja, Head of Section at HUS Neurocenter’s Department of Neurosurgery and University of Helsinki, who came up with the idea for the study.

Smoking is not only a major risk factor for brain hemorrhages and intracranial aneurysms; the negative effects of smoking on many other aspects of health are also significant. That is why quitting smoking improves health in a wide variety of ways. Neurosurgeons Huhtakangas and Korja are already planning a larger screening study, and several European neurosurgical institutes have expressed provisional interest in taking part.

Further information:

Justiina Huhtakangas,
Consultant Neurosurgeon, MD,
HUS Helsinki University Hospital, University of Helsinki

Original publication:

Huhtakangas, Numminen, Pekkola, Niemelä, Korja:

Screening of unruptured intracranial aneurysms in 50 to 60-year-old female smokers: a pilot study. Scientific Reports, 2021.