MY CONTENT

More than 100 conservatively managed nonstroke dissecting vertebrobasilar artery aneurysms were followed on average for 3 years. Ninety-seven percent of patients remained clinically unchanged and the 3 patients who deteriorated clinically had aneurysm enlargement. The natural course of these lesions suggests that acute intervention is not always required and close follow-up without antithrombotic therapy is reasonable. Patients with symptoms due to mass effect or aneurysms of >10 mm may require treatment.