Nonatherosclerotic vascular disease: biological and pathological basis

Atherosclerosis is the main cause of vascular disease in most cases; in about 10 % of cases, carotid artery disease is related to nonatherosclerotic causes, including several unfrequent pathologies such as Takayasu arteritis, giant cell arteritis, fibromuscular disease, moyamoya syndrome, arterial dissection and extracranial carotid aneurysm. These entities are discussed in the present chapter, with a special focus on pathogenesis. Indeed, the aetiology of these diseases is in most cases not completely known, since related to several factors (genetic, immune and infectious). Early diagnosis, usually leading to a good patient’s outcome, is usually achieved after clinical examination and imaging tests.