Bilateral foetal origin of posterior cerebral artery coexisting with absent A1 segment of anterior cerebral artery.

Abstract

Background: Cerebral arterial circle variants are well-described due to their clinical significance for neurosurgeons and neuroradiologists.

Materials and methods: This magnetic resonance angiography (MRA) report describes the unusual coexistence of three cerebral variants incidentally identified in a 44-year-old female patient.

Results: The right-sided first segment (A1) of the anterior cerebral artery (ACA) was absent, and both the posterior cerebral arteries (PCAs) originated from the internal carotid arteries (ICAs). Thus, unilateral A1 segment absence coexisted with a bilateral PCA of foetal origin. These variants' coexistence significantly disrupted the patient's primary collateral pathway.

Conclusions: The clinical significance and consequences of such variants after stroke or transient ischaemic attack cannot be overstated, underlining the importance of the latest imaging findings in understanding and managing these conditions.