Study Finds Dissecting Aneurysms in Neck Arteries Do Not Increase Stroke Risk in First Six Months

Adults who developed a dissecting aneurysm alongside a cervical artery dissection did not experience an increased risk of stroke within the first six months after diagnosis compared to those with cervical artery dissection alone, according to a preliminary study analysis. The research, drawn from the global STOP-CAD registry, examined data from over 4,000 participants and found that approximately 19% had a dissecting aneurysm, yet this condition did not correlate with higher stroke rates or mortality in the short term. Cervical artery dissection, which involves a tear in the inner lining of a neck artery, accounts for about 2% of all ischemic strokes but up to 25% of strokes in adults under 50, making these findings particularly relevant for younger populations.

The study, to be presented at the American Stroke Association’s International Stroke Conference 2026, analyzed data from the Antithrombotics for Stroke Prevention in Cervical Artery Dissection (STOP-CAD) study, a multicenter international registry. Researchers stratified patients based on the presence of dissecting aneurysms, which occur when blood leaking through a tear forms a bulge in the artery wall. They identified that individuals with dissecting aneurysms were more likely to have a history of migraines, connective tissue disorders, or minor neck trauma prior to the dissection, factors that could aid clinicians in monitoring. Despite about 10% of those with aneurysms showing growth over six months, this growth did not lead to an elevated stroke risk.

Muhib Khan, M.D., M.B.B.S., an associate professor in neurology at the Mayo Clinic and study author, noted the scarcity of scientific information on dissecting aneurysms, emphasizing that the registry data provides a comprehensive overview of diagnosis and outcomes. Co-author Zafer Keser, M.D., also from the Mayo Clinic, highlighted that dissecting aneurysm formation was not linked to hemorrhagic stroke or increased mortality, offering reassurance to healthcare professionals and patients. The findings suggest that intensive imaging and interventions, such as carotid stenting, might be reconsidered given the low stroke recurrence risk, as noted by Louise D. McCullough, M.D., Ph.D., FAHA, a former chair of the International Stroke Conference who was not involved in the study.

Limitations include the retrospective design and reliance on non-standardized image reviews by radiologists and neurologists, indicating a need for prospective studies to confirm results. The STOP-CAD registry enrolled patients from 63 sites across 16 countries from 2010 to 2023, with primary coordination at Brown University. For further details, the abstract is available in the American Stroke Association International Stroke Conference 2026 Online Program Planner. The American Heart Association/American Stroke Association notes that abstracts from scientific meetings are preliminary until peer-reviewed publication, and their content reflects the authors' views alone.