Clinical features

Proximal occlusion of the posterior cerebral artery involves all perforating branches and the structures they supply, resulting in:

• midbrain syndromes - Weber's syndrome
• thalamic syndrome - chorea or hemiballismus with hemisensory disturbance

Occlusion of the cortical vessels produces:

• homonymous hemianopia
• macular sparing - due to overlap of the posterior and middle cerebral arteries at the occipital pole

Infarction in the dominant hemisphere may produce difficulty in naming colours and objects.

Occasionally, an embolus in the basilar artery fragments at the bifurcation into the posterior cerebral arteries and may cause total bilateral blindness.