Non-atherosclerotic Cerebral Vasculopathies

Non-atherosclerotic vasculopathies are uncommon causes of stroke accounting for 15–25% of stroke in the young. NAVs comprise a heterogeneous group of local or systemic disorders with various underlying etiologies, including infectious, immunological, hematological, hereditary, idiopathic, and collagenopathies; thus the diagnosis requires complex and elaborate work up. Advances in neuroimaging modalities and novel magnetic imaging techniques have become powerful tools in early diagnosis, and monitoring of treatment effect. Additionally, such technologies have been tremendously helpful in differentiation among the various vasculopathies. Among the most common of the NAVs predominantly affecting the extracranial cervical arteries is arterial dissection, which is often inter-linked with other uncommon arteriopathies including fibromuscular dysplasia and collagen vascular disorders. Intracranial NAVs are of particular importance in children and young adults. In this chapter, we will review the most common NAVs of the extracranial and intracranial vasculature, including arterial dissection, moyamoya disease, reversible cerebral vasoconstriction syndrome, focal arteriopathy of childhood, primary and systemic cerebral vasculitides including infectious etiologies (with recent reported associations in the setting of coronavirus-19, along with drug-induced, and post-radiation vasculopathies. Mechanisms of stroke, clinical manifestations, diagnostic criteria, novel imaging modalities, and treatment approaches will be discussed.