Presentation
Pregnant patient with acute headache and hemiparesis on left side. No past medical history.
Patient Data
Axial T2WI, T2GRE and sagittal T1WI shows right peri ventricular hematoma extending to the right lateral ventricle. Right lateral, third and fourth ventricles filled with intraventricular hemorrhage.
3D TOF MRA shows the incidental anomalous artery arising from the cavernous segment of left ICA, running posteromedially and connect with the basilar artery. No fusiform dilatation and saccular aneurysm was found. Proximal segment of basilar artery and intracranial segments of vertebral arteries are hypoplastic.
Case Discussion
Carotid-vertebrobasilar anastomoses are transient connections which appear during embryonic development between the anterior and posterior circulations. These embryonic anastomotic vessels usually regress and disappear in post-natal period. In rare cases these vessels persist in adults. They are the persistent trigeminal artery, otic (acoustic) artery, hypoglossal artery, and proatlantal intersegmental artery. The most common type is persistent trigeminal artery.