Fig. 1.

Perfusion computed tomography (CTP) and magnetic resonance imaging (MRI) of all 4 patients. The first two images on top row show a CTP of patient 1 while symptomatic, with delayed perfusion in the right fronto-parietal cortex, as shown in the time-to-peak (TTP) with normal perfusion of deep structures; third and fourth images show follow-up diffusion weighted imaging (DWI) MRI of the same patient after symptom resolution with patchy acute ischemic lesions in the right convexity, sparing the basal ganglia. The two images to the left on the second row show TTP CTP of patient 2, during the first asymptomatic phase, with delayed perfusion on the left insular, frontal and parietal cortex with normal perfusion of basal ganglia; the two images to the right show MRI fluid attenuated inversion recovery (FLAIR) sequences after the onset of right hemichoreic movements, where ischemic left insular, frontal, and postcentral gyrus lesions can be appreciated; note the absence of compromise of the deep territory. The two images on the third row consist of the DWI MRI sequences of patient 3, performed while symptomatic, demonstrating a right hemispheric ischemic lesion on the posterior insula and parietal cortex, sparing the basal ganglia. Bottom row shows three DWI MRI images of patient 4, performed 24 hours after symptom onset, with ischemic lesions in the left posterior insular and parietal cortex, also without involvement of deep gray matter structures.