[Epidemiology and pathophysiology of spontaneous cervical artery dissection].

Spontaneous cervical artery dissections are produced by the penetration of circulating blood into the vessel wall of one or more cervical arteries, without a preceding major trauma. Dissection is one of the most frequent etiologies of ischemic stroke in young patients. Its annual incidence is about 3 per 100,000. Pathophysiology of cervical artery dissection remains misunderstood. Triggering factors such as minor trauma and infection have been identified. However, they are too trivial to explain alone the occurrence of a mural hematoma. Several abnormalities suggesting an underlying arteriopathy related to an extracellular matrix defect which could predispose to dissection have been reported: arterial redundancies, intracranial aneurysms, aortic root dilatation, common carotid artery distensibility increase, fibromuscular dysplasia, inherited connective tissue disorders, ultrastructural dermal connective tissue abnormalities. Other factors associated with dissection, such as migraine, hyperhomocysteinemia and alpha-1 antitrypsin deficiency, suggest arterial wall fragility secondary to hyperactivity of some proteases. If an underlying arteriopathy is likely, its nature remains unidentified to date and does not seem to be unique.