Lateral occipital artery

At a glance

English

Lateral occipital artery

Latin (TA2)

Arteria occipitalis lateralis

System

Artery

Region

Head

Side

Paired, left and right

About the lateral occipital artery

The lateral occipital artery is one of the two vessels into which the posterior cerebral artery divides as it curves round the midbrain and reaches the underside of the cerebral hemisphere. Its partner is the medial occipital artery, which heads for the medial surface and the calcarine region. Because the division takes place on the inferior surface, the lateral occipital artery belongs to the part of the posterior cerebral artery often labelled P3, the segment in the quadrigeminal and ambient cisterns behind the midbrain.

From its origin the artery runs laterally and backwards across the inferior, or tentorial, surface of the hemisphere, resting above the tentorium cerebelli. It breaks into temporal branches. Anterior temporal branches reach the front of the parahippocampal and occipitotemporal gyri, intermediate branches run across the middle of the basal surface, and posterior temporal branches continue towards the occipital pole. The furthest twigs curl round the inferolateral margin of the hemisphere, where they meet terminal branches of the middle cerebral artery.

So it serves the underside of the occipital lobe together with the back part of the temporal lobe. This includes much of the fusiform (occipitotemporal) gyrus, a region involved in recognising faces, colours and visual objects, and part of the parahippocampal gyrus, which lies close to the hippocampus and takes part in memory. The artery does not normally carry the main blood supply of the primary visual cortex; that falls to the calcarine branch of the medial occipital artery.

Blockage of the lateral occipital artery is less common than blockage of the whole posterior cerebral artery, but it can damage the underside of the temporal and occipital lobes. Depending on side and extent, the result may be trouble recognising faces or colours, or a disorder of memory when the medial temporal region is involved, while central vision can be spared. On angiograms the branches are seen fanning out below the hemisphere from the posterior cerebral trunk.

Course and supply

Arises from

The more lateral of the two end branches of the posterior cerebral artery, arising on the inferior surface of the hemisphere behind the midbrain.

Ends in

Ends in anterior, intermediate and posterior temporal branches on the basal temporal and occipital surface, joining terminal twigs of the middle cerebral artery.

Supplies

Supplies the underside of the occipital lobe and the hinder temporal lobe, including the fusiform and parahippocampal gyri.