The present paper reports a case of a 14-year-old-female adolescent who presented a single episode of syncope, without any other symptom. Axial and coronal T2-weighted magnetic resonance imaging demonstrated an absent right internal carotid artery flow void. A subsequent magnetic resonance angiography utilizing the time-of-flight technique showed absence of the right internal carotid artery. This finding was confirmed by magnetic resonance angiography of the cervical vessels, and axial computed tomography angiography showed agenesis of the right carotid canal. The literature reports such finding in association with other anomalies such as transsphenoidal encephaloceles and circle of Willis aneurysms. These associations were not observed in the present case. The patient remained asymptomatic.

Keywords: Internal carotid artery, Agenesis, Syncope