Dissection of the carotid and the vertebral arteries

Dissection of the carotid or vertebral arteries (collectively known as the cervical arteries) refers to the separation of the tunica media and tunica intima of a vessel. Cervical artery dissection can cause stenosis, thrombosis, or distal embolization. Most affected individuals are adults. Cervical artery dissections may occur after major trauma (e.g., motor vehicle crashes) or minor events (e.g., sneezing) and typically manifest with a headache, which may be followed by ischemic features (e.g., stroke) a few hours or days later. CT angiography (CTA) or MR angiography (MRA) of the head and neck is used to establish the diagnosis. Management is based on clinical presentation and includes antithrombotic agents for most patients, thrombolysis for patients with signs of ischemic stroke, and surgery in selected cases. Complications include recurrent stroke and/or dissection, delayed formation of a dissecting aneurysm, and complications associated with ischemic stroke.

For traumatic neck injuries, see “Penetrating neck trauma,” “Blunt neck trauma,” and “Soft tissue injuries of the head and neck.”

• Mean age
  • Carotid artery: 40–45 years ^[1]
  • Vertebral artery: 40 years ^[2]
  • Important causes of stroke in young patients
• Occurrence: Dissection of the carotid artery occurs more frequently than dissection of the vertebral artery (∼ 4:1). ^[3]

Epidemiological data refers to the US, unless otherwise specified.

• Triggers ^[4]
  • Penetrating or blunt trauma, e.g.:
    • Motor vehicle crashes
    • Mild trauma (e.g., falls)
  • Minor events (e.g., coughing, sneezing, chiropractic maneuvers, heavy lifting)
  • Playing sports (e.g., volleyball, basketball)
  • Sexual intercourse
  • Childbirth
  • Posterior oropharyngeal injury (especially in children)
• Risk factors
  • Ehlers-Danlos syndrome
  • Marfan syndrome
  • Fibromuscular dysplasia
  • Hypertension
  • Cystic medial necrosis
  • Respiratory tract infection
  • Oral contraceptive use

Dissection of the carotid artery

• Nonischemic features
  • Ipsilateral headache; and facial/neck pain (constant, severe, throbbing or sharp)
  • Partial Horner syndrome: ptosis and miosis
  • Pulse-synchronous tinnitus
  • Neck swelling
  • Reduced taste sensation
  • Cranial nerve lesions, usually caudal nerves (VI–XII)
• Ischemic features
  • Symptomatic middle cerebral artery infarction (see “Stroke”)
  • Amaurosis fugax (ischemic retina)

Dissection of the vertebral artery

• Nonischemic features
  • Occipital headache
  • Posterior nuchal pain
• Ischemic features: vertebrobasilar insufficiency (leads to stroke resembling lateral medullary dysfunction, e.g., Wallenberg syndrome)
  • Ipsilateral loss of taste and facial pain and numbness (most common symptom)
  • Contralateral pain relief and reduced temperature sensation
  • Vertigo
  • Ataxia
  • Central Horner syndrome
  • Dysphagia and dysarthria or hoarseness
  • Nausea, vomiting

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.

Obtain emergency neuroimaging, e.g., CT head without contrast, for all patients with signs of acute ischemic stroke to rule out intracranial hemorrhage.

Approach ^[5]

• Perform a clinical evaluation, including a neurological examination.
  • Signs of acute ischemic stroke: See “Initial management of acute stroke.”
  • Absence of ischemic features: Obtain MRA or CTA head and neck.
• Consult neurology and/or vascular surgery for:
  • Further diagnostics, e.g., angiography for patients with ongoing clinical concerns and negative MRA or CTA head and neck
  • Consideration of interfacility transfer (e.g., tertiary care facility)
• For patients with dissection, consider evaluation for connective tissue disease or fibromuscular dysplasia based on clinical suspicion.

Obtain a detailed history of triggers and nonischemic features, as cervical artery dissection can be difficult to diagnose in the absence of ischemic symptoms. ^[4]

Imaging ^[5][6][7]

MRA and CTA ^[5]

• First-line imaging studies to evaluate for cervical dissections
  • CTA head and neck
  • MRA head and neck
• Findings
  • Irregular and asymmetrical vessels
  • Intimal flap
  • Intramural hematoma
  • Double lumen
  • Dissecting aneurysm
  • Tapering stenosis or occlusion

Angiography ^[7]

Angiography is the most accurate imaging option for assessing degree of stenosis, but it is not suitable for screening due to the periprocedural risk of iatrogenic dissection and stroke. ^[5]

• Flame-shaped tapering of the vessel
• Intimal flap
• Double lumen

Duplex ultrasonography ^[7]

Duplex ultrasonography is of limited diagnostic value, as it is highly operator-dependent and may miss high cervical dissections. ^[5]

• Double lumen on B-mode
• Echodense material within the lumen
• High-resistance flow pattern or absence of flow on Doppler ultrasound

Approach ^[5]

• Signs of acute ischemic stroke: Treat as ischemic stroke (see “Initial management of acute stroke”).
• Absence of ischemic features or following stroke treatment:
  • Consult vascular surgery and/or neurosurgery for possible invasive treatment (e.g., mechanical thrombectomy, stenting)
  • Initiate antithrombotic therapy (e.g., antiplatelet, anticoagulation) with specialist consultation.

Rule out intracranial hemorrhage before initiating any treatment.

Perform baseline monitoring parameters (e.g., INR, PT, PTT) before administering anticoagulant therapy.

Antithrombotic therapy ^[5][8]

The choice of agent and duration of therapy are based on patient factors and usually determined by a specialist.

• Duration: typically 3–6 months
• Patients with low bleeding risk
  • Parenteral anticoagulation (e.g., with heparin) followed by oral anticoagulation
  • OR dual antiplatelet therapy (DAPT)
• Patients with moderate bleeding risk
  • DAPT
  • OR antiplatelet monotherapy

Invasive treatment ^[5]

Decisions on invasive treatments are made on an individual basis and by specialists; options include:

• Acute mechanical thrombectomy or stenting
• Subacute angioplasty and stenting

Most asymptomatic pseudoaneurysms, which commonly follow dissection, do not require additional interventions. ^[9]

• Complications of ischemic stroke (see “Complications” in “Overview of stroke”)
• Recurrent stroke and dissection ^[10]
• Delayed formation of a dissecting aneurysm (also called pseudoaneurysm) of a cervical artery ^[5]
  • Occurs in ∼ 20% of patients within 6 months of presentation
  • Prognosis is generally benign; monitoring is appropriate for asymptomatic patients. ^[9]
  • Treatment (e.g., coiling, stenting) may be required for symptomatic dissecting aneurysms.

We list the most important complications. The selection is not exhaustive.