Orbitofrontal branches of anterior cerebral artery

The orbitofrontal (frontobasal) arteries are divided into medial orbitofrontal artery (MOFA) from the anterior cerebral artery (ACA) and the lateral orbitofrontal artery (LOFA) from the middle cerebral artery (MCA).

The orbitofrontal branches of anterior cerebral artery (a.k.a. the medial orbitofrontal or medial frontobasal artery) represent the first cortical branches of the anterior cerebral artery (ACA) dedicated to perfusing the base and medial aspects of the frontal lobe.

Origin and course

The medial orbitofrontal artery arises as first cortical branch from the A2 (post-communicating) segment of the ACA, typically about 7 - 8 mm distal (anterior) to the anterior communicating artery (ACoA). It originates medial to the gyrus rectus, requiring interhemispheric dissection towards the ACoA complex for surgical exposure. The artery then descends and courses anteriorly within the interhemispheric fissure, passing diagonally across the proximal olfactory tract toward the olfactory sulcus and the floor of the anterior cranial fossa.

Vascular Territory

The main medial orbitofrontal artery gives off several cortical branches that supply the inferior and medial aspect of the frontal lobe's orbital surface, including the:

• Olfactory bulb and olfactory tract

• Gyrus rectus and medial orbital gyri

• Ventromedial and inferomedial prefrontal cortex

Functional and clinical correlates

The ventromedial and orbitofrontal regions regulate emotional processing, executive decision-making, social inhibition, and goal-directed behaviour. Ischemic infarcts of these regions due to blockage of medial orbitofrontal branches of anterior cerebral artery, can lead to orbitofrontal frontal lobe syndromes characterized by personality alteration, social disinhibition, executive dysfunction, impaired judgment, emotional blunting, and abulia (lack of initiative).

Iatrogenic injury during anterior cranial fossa or subfrontal surgery can cause ipsilateral anosmia.