Genetic factors such as constitutional weakness of the arterial wall might have a role in the pathophysiology of CCAD, and environmental factors such as minor trauma acts as a trigger [17] and [18]. BMN 673 The presence of an underlying vasculopathy is suggested

by commonly present concomitant arterial anomalies such as FMD, monogenic connective tissue disease, mainly Ehlers-Danlos syndrome or Marfan’s syndrome. There are several reports of familial cases of CCAD in the absence of known connective tissue disorders. In older patients hypertension plays a role, but despite ample work-up in most patients, the cause is never found [17]. Arterial dissections begin with a tear in the intima or media resulting in bleeding within the arterial wall [18]. Intramural blood dissects longitudinally and spreads along the vessel proximally and distally.

SCH772984 solubility dmso Dissections can tear through the intima, permitting partially coagulated intramural blood to enter the lumen of the artery. Expansion of the arterial wall by intramural blood causes compression of the lumen. Narrowing of the lumen by the intramural blood compromises the blood flow stream and perturbation of the vascular endothelium causes release of endothelins and tissue factor, activation of platelets and the coagulation cascade. All these changes contribute to formation of an intraluminal thrombus. The intramural hematoma can create a false lumen that might reconnect with the true lumen and forms parallel flow. The true and false lumen are separated RNA Synthesis inhibitor by an elongated intimal flap. If the dissection lies between the media and the

adventitia, an aneurysmal dilatation of the arterial wall may extrude. Intracranial rupture through the adventitia causes subarachnoid bleeding. The most dominant symptom is pain in head and neck, in the region of the dissection, usually developing after minor trauma. Some patients present only with headache, or a combination of headache and local signs. Clinical presentations result from bleeding in subintimal and subadventitial wall [17]. If the dissections compromise the arterial lumen or cause thrombus formation in the lumen, clinical symptoms are the result of luminal compromise and the presence of luminal clot. Ischemic symptoms and infarction in the brain are caused by both reduced perfusion in the brain artery supplying territory or embolism. Neurological symptoms related to hypoperfusion are usually multiple brief transient ischemic attacks (TIAs) during a period of several hours to a few days. Hypoperfusion may decrease washout of emboli and contributes to the development of brain infarction. Bleeding in the subadventitial wall results in compression of the adjacent structures to the outer arterial wall like lower cranial nerves (IX–XII) that exit near the skull base, or causes bleeding into adjacent tissues.