Two young women developed encephalopathy, hearing loss and retinal arteriolar occlusions. Their behaviour became immature and cognitive functions were severely impaired. One of the patients underwent brain biopsy, which showed several microinfarcts in both white and grey matter and microangiopathic changes, with thickened arteriolar segments staining intensely for laminin and fibronectin. These findings support the concept of a new type of microangiopathy involving the brain, inner ear and retina.