Carotid or vertebral artery dissection describes the separation of the tunica media and tunica intima of a vessel. This can lead to thrombosis of the false lumen, which can, in turn, lead to stenoses or embolisms with the risk of stroke. Dissections of the carotid and vertebral artery primarily affect young adults and may occur spontaneously or as a result of a major trauma (e.g., car accidents). The initial symptoms are usually headaches (temporal and occipital for carotid and vertebral artery dissection respectively), which may be followed by features of ischemia (e.g., stroke) a few hours or days later. Duplex ultrasonography may provide a rapid diagnosis, but definitive diagnosis requires CT angiography or MR angiography. Treatment is primarily conservative and involves blood thinners, anticoagulants, and antiplatelet therapy. Severe cases may require surgery.
- Mean age
- Occurrence: Dissection of the carotid artery occurs more frequently than dissection of the vertebral artery (∼ 4:1). 
Epidemiological data refers to the US, unless otherwise specified.
- Frequently caused by penetrating or blunt trauma (e.g., high impact car accidents) but up to 40% of cases result from mild trauma (e.g., minor sports injuries) or other mechanical triggering events (e.g., coughing, sneezing, chiropractic maneuvers)
- Spontaneous dissection
Dissection of the carotid artery
- Non-ischemic features
- Ischemic features
Dissection of the vertebral artery
- Non-ischemic features
- Ischemic features: vertebrobasilar insufficiency (leads to stroke resembling lateral medullary dysfunction, e.g., )
Carotid or vertebral artery dissection is the separation of the tunica media and tunica intima of a vessel. This can lead to thrombosis of the false lumen, which can, in turn, lead to stenoses or embolisms with the risk of stroke.
- Duplex ultrasonography: high resistance flow or complete absence of flow in affected artery
Helical CT angiography (replacing MRI as diagnostic modality of choice ;)
- Changed caliber of vessel
- Oval or slit-like cross-section of vessel
- Intramural blood
- Mural expansion
- Irregular vessel margins
- Filling defects 
- Extravasation of contrast 
- Caliber changes of vessel
- Conventional angiography
- Treatment should be initiated after an intracerebral hemorrhage has been ruled out.
- Possibly angioplasty/stenting or surgical intervention may be warranted in severe cases
Asymptomatic pseudoaneurysms do not usually require treatment and most dissections heal spontaneously.