Persistent primitive olfactory artery: diagnosis with MR angiography

Embryology of the anterior communicating artery complex: implications on possible adult variants

The anterior cerebral artery (ACA) and the anterior communicating artery (AComA) are important arteries of the telencephalon and are prominent location for cerebral aneurysms. Their embryological development is closely linked, and explains the possible variants seen in adults. In this paper, we present details related to the development of these two arteries, focusing on some variants such as the infra-optic course of the ACA, the unpaired ACA, and the persistent primitive olfactory artery.

Aneurysm of the A1 Segment of the Anterior Cerebral Artery Associated with the Persistent Primitive Olfactory Artery

BACKGROUND

The persistent primitive artery constitutes the anterior cerebral artery proper. When the persistent primitive artery keeps its embryologic course along the olfactory bulb, it is called the persistent primitive olfactory artery (PPOA).

CASE DESCRIPTION

A 69-year-old man presented with an incidentally discovered unruptured aneurysm at the origin of the PPOA. The PPOA originated at the A1 segment of the anterior cerebral artery, coursed anteromedially along the olfactory tract, made a hairpin turn posterosuperior to the midline, and formed the callosomarginal branch of the anterior cerebral artery. The anomalous artery was interpreted as a PPOA (type 3). Type 3 PPOA associated with an unruptured aneurysm is rare.

CONCLUSIONS

There is a high incidence of aneurysms associated with a PPOA. Follow-up studies are necessary in the present case to monitor for the development of another aneurysm at the hairpin bend.

New variant of persistent primitive olfactory artery associated with a ruptured aneurysm

The authors present the case of a 78-year-old man who presented with a subarachnoid hemorrhage due to rupture of an aneurysm at the origin of the persistent primitive olfactory artery (PPOA). Interestingly, the PPOA was originating from the A1 segment of the anterior cerebral artery and coursed anteromedially along the olfactory tract. Moreover, the PPOA in this case had 2 branches: the branch making a hairpin turn and supplying the distal part of the anterior cerebral artery territory (Type 1), and the branch extending to the cribriform plate to supply the nasal cavity (Type 2). To the best of the authors' knowledge, this is a new variant (Type 3) of PPOA associated with a ruptured aneurysm. The clinical implications of this case are discussed in terms of the embryological aspects.

Diagnosis of persistent primitive olfactory artery using computed tomography angiography

Persistent primitive olfactory artery (PPOA) is a rare anomaly of the anterior cerebral artery. We present one case of PPOA incidentally diagnosed with the aid of computed tomography (CT) angiography. A 24-year-old woman was admitted to our hospital after sudden onset of vertigo. Three-dimensional CT angiography revealed an anomalous artery arising from the terminal portion of the right internal carotid artery. The proximal portion of the anomalous artery coursed anteromedially and made a hairpin turn posterosuperior to the midline. PPOA may be overlooked because of its rarity, but CT angiography can be useful in detecting this rare vascular anomaly. Follow-up study is necessary in our case to confirm whether an aneurysm occurs on the PPOA.

Persistent primitive olfactory artery aneurysm

A hypertensive 69-year-old man presented with an incidentally discovered non-ruptured aneurysm of the persistent primitive olfactory artery (POA). The POA originates at the terminal portion of the internal carotid artery, runs along the olfactory tract anteriorly toward the crista galli, and forms an acute angle with the distal anterior cerebral artery. The aneurysm was located at this characteristic acute angle. The persistent POA aneurysm associated with an anterior communicating artery aneurysm with wide neck was successfully treated by clipping surgery.