Cerebral artery territory infarct syndromes

What it is

The blood supply to the brain runs through the anterior cerebral artery, the middle cerebral artery, the posterior cerebral artery and the carotid artery, and the key beside them names four territories: an ACA territory, an MCA territory, an anterior choroidal territory and a PCA territory. The deep parts labelled inside are the caudate nucleus, the putamen, the globus pallidus, the internal capsule and the thalamus, around the Sylvian fissure. The bracket labelled circle of Willis spans four labels only: the anterior communicating artery, the middle cerebral artery, the posterior communicating artery and the posterior cerebral artery. The anterior cerebral artery is labelled above that bracket, and the basilar artery, the vertebral artery and the posterior inferior cerebellar artery below it, outside the circle of Willis. Reading a brain lesion means reading which territory the deficits fit.

How it presents

• Middle cerebral artery occlusion: contralateral somatosensory and motor deficit of face, arm and leg; conjugate eye deviation toward the side of the infarct; homonymous hemianopia; aphasia with a dominant hemisphere lesion; hemineglect with a nondominant hemisphere lesion.
• Anterior cerebral artery occlusion: contralateral somatosensory and motor deficit, predominantly in the lower extremity; abulia, which is lack of will or initiative; dyspraxia, emotional disturbances and urinary incontinence.
• Posterior limb of the internal capsule, the lacunar infarct: unilateral motor impairment, no sensory or cortical deficits, and no visual field abnormalities. A purely motor picture is the point.
• Vertebrobasilar system lesion, supplying the brain stem: alternate syndromes, meaning contralateral hemiplegia with ipsilateral cranial nerve involvement, and possible ataxia.