White matter disorder due to CADASIL

**Long definition:** Typically, patients present with migraine with a mean age at onset of 30 years; ischaemic events usually have their onset in the late 40s. As microvascular changes progress, patients develop cognitive and psychiatric symptoms and seizures. More than 90% of affected individuals have NOTCH3 mutations in the exons sequenced. The characteristic small vessel arteriopathy may be diagnosed from a skin biopsy.