Positive platelet scintigram of a vertebral aneurysm presenting thromboembolic transient ischemic attacks.

We describe a patient with transient ischemic attacks secondary to a giant aneurysm who showed increased activity on platelet scintigrams at the origin of the left vertebral artery. This is assumed to be the first report of a presumed embolizing aneurysm with positive activity of labeled platelets. Platelet scintigraphy is useful for diagnosing transient ischemic attacks as being secondary to an aneurysm and was proved to provide direct evidence of a thromboembolic source in vivo.