Anterior cerebral artery

At a glance

English

Anterior cerebral artery

Latin (TA2)

Arteria cerebri anterior

System

Artery

Region

Head

Side

Paired, left and right

About the anterior cerebral artery

The anterior cerebral artery is one of the paired arteries at the front of the cerebral arterial circle (circle of Willis). It leaves the internal carotid artery below the anterior perforated substance, beside the optic chiasm, and runs forwards and medially above the optic nerve to the beginning of the longitudinal fissure. There it is joined to its fellow of the opposite side by the short anterior communicating artery. From that point the two vessels run side by side up the fissure, bend round the genu of the corpus callosum and travel backwards over its upper surface.

Its course is divided into segments. A1 is the precommunicating part, from the carotid to the communicating artery; it gives medial lenticulostriate (anteromedial central) arteries to the caudate head and the front of the internal capsule. A2 runs from the communicating artery to the point where the vessel divides; near its start arises the recurrent artery of Heubner, the long medial striate artery to the internal capsule, followed by the orbitofrontal and frontopolar branches. Beyond this the pericallosal artery follows the callosal sulcus and ends as the precuneal and parietal branches, and the inconstant callosomarginal artery runs in the cingulate sulcus, giving medial frontal, paracentral and cingulate branches. The pericallosal artery may meet branches of the posterior cerebral artery near the splenium.

Overall it supplies the medial surface and upper border of the frontal and parietal lobes, including the leg and foot area of the motor and sensory cortex, most of the corpus callosum apart from its hindmost fifth, and, deep in the hemisphere, the front limb of the internal capsule, some of the caudate and the forward part of the globus pallidus. In the embryo it grows from an early forward division of the internal carotid. Variation is common: one A1 may be small, or an extra A2 may be present.

Occlusion before the communicating artery is often silent because the other side fills the territory. Blockage beyond it causes weakness of the opposite leg and foot with loss of cortical sensation there, disturbance of gait, apathy and slowness with reduced speech and spontaneity, frontal release signs such as grasping, and urinary incontinence, mainly when both sides are affected.

Course and supply

Arises from

The internal carotid artery, as its smaller terminal branch beside the optic chiasm below the anterior perforated substance.

Ends in

Ends over the medial surface of the hemisphere as the pericallosal artery and, when present, the callosomarginal artery, reaching back to the parieto-occipital sulcus.

Supplies

Supplies the medial and upper surfaces of the frontal and parietal lobes, the front of the corpus callosum, the caudate head, the front limb of the internal capsule and the forward globus pallidus.