An abnormal artery originating from the cervical internal carotid artery with hypoplastic vertebrobasilar arteries: a case report

Abstract

In carotid ultrasonography, it has been emphasized that the existence of ramifications is an important differential finding between the external carotid artery (ECA) and the cervical internal carotid artery (CICA). We report the case of a patient with an abnormal artery originating from the CICA accompanied by hypoplastic vertebrobasilar arteries (VBA) who developed a brainstem infarction. The patient was a 73-year-old woman. In 2013, carotid ultrasonography showed an abnormal artery (diameter 2.2 mm, time-averaged maximal velocity 34 cm/s, pulsatility index 2.4) originating from the CICA that was located 2 cm distal from the right carotid bifurcation. In December, 2014, she developed paresthesia from the neck to the right ear, numbness of the right arm and leg, and right foot motor weakness. MRI showed an infarction in the rostral pons extending to the left midbrain. The abnormal artery that originated from the right CICA associated with the right primitive trigeminal artery and hypoplastic VBAs were confirmed by MRA. This was a very rare case of an abnormal artery originating from the CICA. It is necessary to keep in mind that the presence of branching arteries cannot always be used in the differential diagnosis between the ECA and CICA in carotid ultrasonography.