Carotid artery dissection
Classification and external resources
ICD-9	443.21
DiseasesDB	2145
eMedicine	emerg/82

Carotid artery dissection is the most common cause of stroke in young adults.^[1]

Contents 1 Signs and symptoms 2 Causes 2.1 Spontaneous 2.2 Traumatic 3 Pathophysiology 4 Treatment 5 Epidemiology 6 See also 7 References

[edit] Signs and symptoms

The signs and symptoms of carotid artery dissection may be divided into ischaemic and non-ischaemic categories:^[2]

Non-ischaemic signs and symptoms

• Headache or neck pain

Ischaemic signs and symptoms

• Decreased pupil size with drooping of the upper eyelid (Horner syndrome)
• Transient vision loss
• Ischemic stroke

[edit] Causes

The cause of internal carotid artery dissection can be broadly categorized into two classes: spontaneous or traumatic.

[edit] Spontaneous

Once considered uncommon, spontaneous carotid artery dissection is an increasingly recognized cause of stroke that preferentially affects the middle-aged.^[3]

The incidence of spontaneous carotid artery dissection is low, and incidence rates for internal carotid artery dissection have been reported to be 2.6 to 2.9 per 100,000.^[4]

Observational studies and case reports published since the early 1980s show that patients with spontaneous internal carotid artery dissection may also have hereditary connective tissue disorders and/or a history of stroke in their family. These include Marfan syndrome, vascular Ehlers-Danlos syndrome, autosomal dominant polycystic kidney disease, pseudoxanthoma elasticum, fibromuscular dysplasia, and osteogenesis imperfecta type I.^[5]

However, the reports on the prevalence of hereditary connective tissue diseases in people with spontaneous dissections is highly variable, ranging from 0% to 0.6% in one study to 5% to 18% in another study. Nevertheless, although an association with connective tissue disorders does exist, most people with spontaneous arterial dissections do not have associated connective tissue disorders.^[6]

[edit] Traumatic

Carotid artery dissection is more commonly thought to be caused by severe violent trauma to the head and/or neck. An estimated 0.67% of patients admitted to the hospital after major motor vehicle accidents were found to have blunt carotid injury, including intimal dissections, pseudoaneurysms, thromboses, or fistulas.^[7] Of these, 76% had intimal dissections, pseudoaneurysms, or a combination of the two.

The probable mechanism of injury for most internal carotid injuries is rapid deceleration, with resultant hyperextension and rotation of the neck, which stretches the internal carotid artery over the upper cervical vertebrae, producing an intimal tear.^[8] After such an injury, the patient may remain asymptomatic, have a hemispheric transient ischemic event, or suffer a stroke.^[9]

[edit] Pathophysiology

Arterial dissection of the carotid arteries occurs when a small tear forms in the innermost lining of the arterial wall (known as the tunica intima). Blood can enter into the space between the inner and outer layers of the vessel, causing narrowing (stenosis) or complete occlusion. The stenosis that occurs in the early stages of arterial dissection is a dynamic process and some occlusions can return to stenosis very quickly.^[10] When complete occlusion occurs, it may lead to ischemia. Often, even a complete occlusion is totally asymptomatic because bilateral circulation keeps the brain well perfused. However, when blood clots form and break off from the site of the tear, they form emboli, which can travel through the arteries to the brain and block the blood supply to the brain, resulting in an ischemic stroke, otherwise known as an infarction. Blood clots, or emboli, originating from the dissection are thought to be the cause of infarction in the majority of cases of stroke in the presence of carotid artery dissection.^[10] Cerebral infarction causes irreversible damage to the brain. In one study of patients with carotid artery dissection, 60% had infarcts documented on neuroimaging.^[11]

[edit] Treatment

The goal of treatment is to prevent the development or continuation of neurologic deficits. Treatments include observation,anticoagulation, stent implantation and carotid artery ligation.

[edit] Epidemiology

70% of the time it occurs in people between 20 and 40 years of age.^[12]

[edit] See also

• Aortic dissection

[edit] References

v • d • e Cardiovascular disease: vascular disease · Circulatory system pathology (I70-I99, 440-456) Arteries, arterioles and capillaries Inflammation Arteritis (Aortitis) · Buerger's disease Arterial occlusive disease/ peripheral vascular disease Arteriosclerosis Atherosclerosis (Foam cell, Fatty streak, Atheroma, Intermittent claudication) · Monckeberg's arteriosclerosis · Arteriolosclerosis (Hyaline, Hyperplastic, oxycholesterol, cholesterol, LDL, trans fat) Stenosis Renal artery stenosis · Carotid artery stenosis Other Fibromuscular dysplasia · Degos disease · Aortoiliac occlusive disease · Raynaud's phenomenon/Raynaud's disease · Erythromelalgia Aneurysm/dissection/ pseudoaneurysm torso: Aortic aneurysm (Thoracic aortic aneurysm, Abdominal aortic aneurysm) · Aortic dissection · Coronary artery aneurysm head/neck: Cerebral aneurysm · Intracranial berry aneurysm · Carotid artery dissection · Vertebral artery dissection · Familial aortic dissection Vascular malformation Arteriovenous fistula · Telangiectasia (Hereditary hemorrhagic telangiectasia) Vascular nevus Spider angioma · Halo nevus · Cherry hemangioma Veins Inflammation Phlebitis Venous thrombosis/ Thrombophlebitis primarily lower limb (Deep vein thrombosis) abdomen (May-Thurner syndrome, Portal vein thrombosis, Budd-Chiari syndrome, Renal vein thrombosis) upper limb/torso (Paget-Schroetter disease, Mondor's disease) head (Cerebral venous sinus thrombosis) Post-thrombotic syndrome Varicose veins Varicocele · Gastric varices · Portacaval anastomosis (Hemorrhoid, Esophageal varices, Caput medusae) Other Superior vena cava syndrome · Inferior vena cava syndrome · Venous ulcer · Chronic venous insufficiency · Chronic cerebrospinal venous insufficiency Arteries or veins Vasculitis · Thrombosis · Embolism (Pulmonary embolism, Cholesterol embolism, Paradoxical embolism) · Angiopathy (Macroangiopathy, Microangiopathy) Blood pressure Hypertension Hypertensive heart disease · Hypertensive nephropathy · Essential hypertension  · Secondary hypertension (Renovascular hypertension) · Pulmonary hypertension · Malignant hypertension · Benign hypertension · Systolic hypertension · White coat hypertension Hypotension Orthostatic hypotension vascular navs: anat/physio/dev, noncongen/systemic vasculitis/congen/neoplasia, symptoms+signs/eponymous, proc