Bilateral persistent primitive olfactory arteries associated with an accessory anterior cerebral artery.

Persistent primitive olfactory artery (PPOA) is a relatively rare variation of the proximal anterior cerebral artery (ACA) that generally follows an extreme anteroinferior course and takes a hairpin turn before continuing to the A2 segment of the ACA. This variation is usually seen unilaterally, and the anterior communicating artery (ACoA) is usually long or absent. We herein report a case of bilateral persistent PPOAs associated with an accessory ACA. The length of the bilateral A1 segments was normal and the length of the ACoA was normally short. Thus, hypoplasia of the distal A1 segment is important but not necessary for the formation of the PPOA. To our knowledge, no similar cases have been reported in the relevant English language literature.