Orbitofrontal branches of middle cerebral artery

The orbitofrontal (frontobasal) arteries are divided into the medial orbitofrontal artery (MOFA) from the anterior cerebral artery (ACA) and the lateral orbitofrontal artery (LOFA) from the middle cerebral artery (MCA). The orbitofrontal branch of middle cerebral artery (a.k.a. the lateral orbitofrontal artery) specifically supply the lateral orbital and inferior frontal surfaces.

Origin and course

The lateral orbitofrontal artery typically arises approximately 9 - 10 mm distal to the MCA bifurcation from the superior frontal trunk (M2 segment). Less frequently, it may originate directly from the main M1 trunk proximal to the bifurcation or present as duplicated stems arising both proximally and distally.

The proximal part of the lateral orbitofrontal artery frequently exhibits a helical morphology and an intraparenchymal course through the posterior orbitofrontal cortex, requiring careful Sylvian fissure dissection for surgical exposure. It travels anteriorly towards the inferior frontal region, distributing multiple cortical branches across the lateral orbital surface of the frontal lobe.

Vascular distribution

• Lateral orbital surface (lateral orbital gyri)

• Orbital part of Inferior frontal gyrus and inferior portion of pars orbitalis, including the orbitofrontal cortex

• An anastomotic network is consistently seen between the lateral and medial orbitofrontal arteries across the orbitofrontal surface, which most commonly cluster around the frontal pole.

Functional and clinical correlates

• Functional integration: Working in tandem with the medial orbitofrontal artery, the lateral orbitofrontal artery perfuses the orbitofrontal cortex, which houses secondary taste areas as well as secondary and tertiary olfactory association regions.

• Behavioural and executive control: This cortical territory is vital for cognitive inhibition, response suppression, reward-punishment processing, and emotional self-regulation.

• Clinical syndromes: Ischemic compromise or structural disruption within these orbitofrontal territories leads to orbitofrontal syndrome, characterized by loss of social and cognitive inhibition, abnormal impulsivity, impaired emotional and social judgment, and marked personality changes.