Carotid dissection with watershed infarct

Case contributed by A.Prof Frank Gaillard


Right sided weakness.

Patient Data

Age: Young adult
Gender: Female
Modality: CT

Non contrast CT demonstrates patchy low density seen in the white matter of the left cerebral hemisphere, in a deep waterzone distribution.

Modality: CT

CT perfusion demonstrates:

  • Increased MTT (consistent with slow flow)
  • Increased cerebral blood volume in the cortex
  • Decreased cerebral blood flow in the white matter

In other words there is a ischaemic penumbra (mismatch between MTT and CBF) encompassing the cortex, which has vasodilation (thus elevated CBV). 


Modality: DSA (angiography)

Angiogram confirms diagnosis of left ICA dissection, seen as a tapering lumen which disappears below the base of skull. 

Patient was treated with endovascular stent placement.

Day 2

Modality: MRI

Diffusion weighted imaging the next day demonstrates only patchy deep border zone restricted diffusion. Little if any cortical infarction is present.

Case Discussion

This young woman presented with a spontaneous carotid dissection and extensive watershed infarction between underperfused MCA territory on the left and ACA / PCA. The perfusion maps correctly identified an ischaemic penumbra encompassing most of the cortex, which was being supplied by collaterals, encouraged by maximal vasodilatation. 

Carotid stent placement re-established cortical perfusion and saved this patient form a devastating stroke. 

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Case Information

rID: 5182
Case created: 15th Dec 2008
Last edited: 30th Jan 2016
Inclusion in quiz mode: Included

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