Dissection, Carotid and Vertebral Artery
- Cervical artery dissection (CAD) is subcategorized into carotid artery dissection (CaAD) and vertebral artery dissection (VAD).
- CAD accounts for 2–2.5% of all ischemic strokes.
CAD is responsible for 10–25% of all ischemic strokes in younger patients (<50 years old).
The incidence of CAD has been reported to be 2.6 per 100,000 annually, likely higher because some CADs are asymptomatic. CaAD is more common, but the ratio of CaAD:VAD may vary in different populations.
The prevalence of CAD is 2.6 to 3.0 per 100,000 population. The average age of patients presenting with CAD is approximately 45 years.
Etiology and Pathophysiology
Intramural hematoma, the pathophysiologic hallmark of CAD, is caused by a subintimal tear into the arterial wall of the carotid and vertebral artery due to spontaneous tear, minor trauma (i.e., Valsalva, physical activity), or overt physical trauma to the neck.
- Intramural blood accumulation creates a false lumen, narrowing the arterial lumen resulting in formation of an aneurysm, occlusion, or rupture of the vessel.
- Stenosis or occlusion of the carotid or vertebral artery results in hypoperfusion, thromboembolism, or both, causing ischemia.
- Hematoma and aneurysm formation of the carotid artery can cause local compression/distension leading to Horner syndrome.
- Arterial rupture of intracranial dissections can result in subarachnoid hemorrhage (SAH) or pseudoaneurysm.
- Iatrogenic dissections can also occur due to catheter manipulation or balloon angioplasty.
- Internal CaAD commonly occurs ≥2 cm distal to carotid bifurcation and near/adjacent to the base of the skull. VAD commonly occurs at the pars transversaria or atlas loop (up to 69%).
There is an increased incidence of CAD in patients with MTHFR C677T genotype. The following genetic disorders have been associated with a higher risk of CAD:
- Fibromuscular dysplasia
- Ehlers-Danlos syndrome type IV
- Marfan syndrome
- α1-Antitrypsin deficiency
- Osteogenesis imperfecta
- Autosomal dominant polycystic kidney disease
- History of radiotherapy to the neck
- Neck manipulation
- Neck trauma, even if minor
- Recent infection
- Carotid or vertebral artery aneurysm
- Genetic disorders mentioned above and associated conditions listed below
- Oral contraceptives
No specific prevention measures are known.
Commonly Associated Conditions
- Retinal ischemia and ischemic optic neuropathy (CAD)
- Spinal cord ischemia and cervical radiculopathies (VAD)
- Oculosympathetic palsy (CAD more often than VAD)
- Low-lying carotid bifurcation
- Cystic medial necrosis
- Moyamoya disease
- Giant cell/temporal arteritis
- Those genetic disorders mentioned in “Genetics”
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