Internal carotid artery stenosis presenting as ipsilateral posterior cerebral artery ischaemic stroke: a lesson to be learnt

Abstract

A 71-year-old lady presented with a symptomatic left cerebral occipital lobe infarct. With a history of paroxysmal atrial fibrillation a cardioembolic source was initially postulated. Prior significant bleeding while anticoagulated precluded warfarin therapy. Further investigations revealed a critical left internal carotid stenosis with a persistent fetal origin of the left posterior cerebral artery. She was successfully treated surgically and suffered no further ischaemic events. Physicians encountering posterior circulation stroke should be aware of this potentially treatable important diagnosis.

Figure 1

CT scan showing left occipital infarction (arrowed).

Figure 2

CT angiography (left) and three-dimensional reconstruction (right) showing proximal left internal carotid artery stenosis (arrowed).

Figure 3

Diffusion weighted MRI showing acute left occipital infarction (left) and patchy anterior circulation watershed infarction (right).

Figure 4

MR angiography confirming bilateral foetal posterior cerebral artery origins (arrowed).

Figure 5

Three-dimensional multidetector CT angiogram showing bilateral foetal posterior cerebral arteries (arrowed). These provide most of the blood supply to the posterior cerebral artery territory. Reproduced with kind permission from Dimmick and Faulder.