Ritu Mishra

Anomalous Circle of Willis with Vertigo

A 4-y-old boy presented with occasional episodes of vertigo since 8 mo. No variation in vertigo was seen with postural changes. He underwent MRI brain and MR angiography (MRA) which showed an azygos anterior cerebral artery (ACA) with hypoplastic A1 segment of right ACA. Fetal origin of left posterior cerebral artery (PCA) with bilateral persistent trigeminal arteries were also present (Figs. 1 and 2). An azygos anterior cerebral artery is a rare variant seen in approximately 0.4–1 % of the population [1]. Fetal PCA may occur in 8 to 10 % of the general population [2]. To the best of authors’ knowledge such complex anomaly has never been described previously in a patient with vertigo. Patient was given symptomatic medical treatment for vertigo. However, it cannot be said conclusively that there is any association between the anomaly and vertigo.