Fig. 1

Proband’s axial magnetic resonance imaging at age 34 years showed extensive T2 hyperintensity in the periventricular and deep white matter of both cerebral hemispheres distributed predominantly in the deep water-shed regions whilst sparing the superficial water-shed territories (a). There was no sulcal FLAIR hyperintensity on coronal imaging (b). Catheter digital subtraction angiography (DSA) showed severe supraclinoid internal carotid stenosis, patulous petrous segment of the internal carotid artery, straightening of cerebral vessels and absent basal moyamoya collaterals (c). The proband’s older sister had similar distribution of T2 hyperintensity (d) and absence of sulcal FLAIR hyperintensity (e) at the age of 37 years. Her DSA showed similar a cerebral vascular anomaly that is distinct from moyamoya disease (f). The proband’s mother, aged 62 years, also had multiple foci of T2 hyperintensity in the deep and subcortical white matter of both hemispheres with physiologic calcification in the globus pallidi bilaterally (g). There was no sulcal FLAIR hyperintensity (h) and MR angiography showed fusiform dilatation of the internal carotid arteries within the proximal carotid canal bilaterally (i)