Common Carotid Artery Agenesis: Duplex Ultrasonographic Findings

BACKGROUND: Agenesis of the common carotid artery (CCA) resulting in separation of the origin of the external carotid artery (ECA) and internal carotid artery (ICA) from the aortic arch is rare. Fewer than 25 cases have been reported, and correlative ultrasound data were available for only 1 of them. CASE REPORT: A 52-year-old woman visited the hospital with a 3-day history of vertigo and headache. Color-coded duplex ultrasonography performed to evaluate the carotid and vertebral arteries revealed a normal configuration on the left side. However, the right CCA could not be found; instead, there were two vessels of approximately equal size in close proximity to each other. The cerebral angiographic findings were consistent with the ultrasonographic findings. The ECA and ICA originated directly from the brachiocephalic trunk, and the ECA arose proximal to the ICA. CONCLUSIONS: The ultrasonographic findings revealed absence of the CCA, the ECA and ICA originating separately from the aortic arch. Color-coded duplex ultrasonography appears to be an effective and sensitive method for detecting absence of the CCA. These findings should help to further our understanding of the embryologic development of the carotid arteries.

Bilateral Cerebellar Ataxia Due to an Unilateral Brain Stem Infarction

No abstract available.

Implications of a Variation of Middle Cerebral Artery in the Interpretation of Transcranial Doppler

The accessory middle cerebral artery (MCA) is a variation of the MCA branching, which originates from the anterior cerebral artery (ACA). It is deemed as an incidental anatomical finding and the incidence is reported to be 0.3% to 4.0%. Although the accessory MCA is infrequent it nevertheless may have important implications in the interpretation of transcranial Doppler (TCD) findings. We report two patients having an accessory MCA and its clinical significance.