Callosomarginal artery

At a glance

English

Callosomarginal artery

Latin (TA2)

Arteria callosomarginalis

System

Artery

Region

Head

Side

Paired, left and right

About the callosomarginal artery

The callosomarginal artery is one of the two main distal branches of the anterior cerebral artery, the other being the pericallosal artery. It leaves the anterior cerebral artery as that vessel curves around the front of the corpus callosum, usually near the genu, in the segment beyond the anterior communicating artery known as A2. It is present in a large proportion of brains but not in all; where it is absent, its branches arise one by one from the pericallosal artery.

From its origin the artery runs backwards in or near the cingulate sulcus, roughly parallel to the pericallosal artery but further from the corpus callosum. The pericallosal artery hugs the upper surface of the corpus callosum, while the callosomarginal artery follows the groove that separates the cingulate gyrus from the medial frontal gyrus above. Along its course it gives a series of branches that climb over the medial surface and spill onto the upper edge of the lateral surface of the hemisphere. These commonly include anterior, middle and posterior internal frontal branches and a paracentral branch; the frontopolar artery may also arise from it rather than from the A2 segment.

Its territory is the medial surface of the frontal lobe, including the medial frontal gyrus and the paracentral lobule, and a strip of the cortex along the top of the lateral surface. The paracentral lobule contains the motor and sensory cortex for the opposite leg and foot, and the medial frontal cortex includes the supplementary motor area involved in planning movement.

Occlusion of the anterior cerebral artery, or of the callosomarginal branch, therefore causes weakness and sensory loss mainly in the opposite leg, with the arm and face largely spared. Damage to the medial frontal cortex may also reduce spontaneous speech and action and affect bladder control. On angiograms the callosomarginal and pericallosal arteries form two parallel arcs, and aneurysms may form where they divide.

Course and supply

Arises from

Arises from the anterior cerebral artery (A2 segment) near the genu of the corpus callosum.

Ends in

Ends in internal frontal and paracentral branches spreading over the medial surface of the hemisphere and onto its upper lateral edge.

Supplies

Supplies the medial frontal gyrus, the cingulate region, the paracentral lobule and the upper margin of the lateral frontal and parietal cortex.