A 56 year old previously healthy man presented with a Glasgow Coma Scale score of 7 and no history of trauma. T1-weighted fat saturated sequence MRI revealed crescentic hyperintense signal in the internal carotid arteries (ICA) in keeping with acute bilateral ICA dissections (A). There were also multiple foci of restricted diffusion in the deep white matter bilaterally with hyperintensities on diffusion weighted imaging (DWI) and corresponding hypointensities on apparent diffusion coefficient (ADC) sequence, in keeping with acute internal watershed infarcts (B). It was hypothesised that the stenoses from the ICA dissections led to ischaemic insults to the border zones between perforating arteries.
