Overview

The middle meningeal artery arises from the first part of the maxillary artery in the infratemporal fossa. It ascends between the two roots of the auriculotemporal nerve and enters the middle cranial fossa through the foramen spinosum.

Inside the skull it runs between the outer (periosteal) layer of the dura and the bone, and divides into two branches. The frontal (anterior) branch passes deep to the pterion, the thin H-shaped junction of the frontal, parietal, temporal and sphenoid bones. The parietal (posterior) branch runs backward. The artery supplies the dura and the skull bones, not the brain.

Anatomy

Course: It runs from the maxillary artery through the foramen spinosum, then in grooves on the inner surface of the squamous temporal and parietal bones.

Function

Supplies the dura mater and the calvarial bone of the middle cranial fossa and the lateral skull.

Clinical significance

Extradural (epidural) haematoma

A blow to the side of the head can fracture the thin bone at the pterion and tear the frontal branch of the middle meningeal artery. Arterial blood then strips the dura off the skull, forming a biconvex (lens-shaped) haematoma that does not cross the suture lines.

Classically, the patient is briefly knocked out, then wakes and seems well (the lucid interval), then deteriorates rapidly. Herniation of the uncus of the temporal lobe compresses CN III, producing a fixed, dilated pupil on the same side. Emergency surgical evacuation through a craniotomy is lifesaving.

Embolisation for chronic subdural haematoma

Blocking the middle meningeal artery from inside (embolisation) lowers the chance that a chronic subdural haematoma will come back.

Test yourself

An extradural (epidural) haematoma after a blow to the pterion usually results from rupture of the:

Middle meningeal artery
Bridging cerebral veins
Anterior communicating artery
Lenticulostriate arteries

Answer: Middle meningeal artery

The frontal branch of the middle meningeal artery runs deep to the thin bone at the pterion. Its rupture produces a biconvex haematoma that does not cross the sutures, often with a lucid interval. Torn bridging veins cause subdural haematomas, and ruptured ACom aneurysms cause subarachnoid haemorrhage.