Carotid Artery Dissection

Introduction

  • Incidence 2.5-3 per 100,000
  • Peak incidence in 5th decade of life
  • Significant cause of strokes in young/middle aged patients (5-22% of strokes in this age group)

Etiology/Predisposing Factors

  • Spontaneous, minor trauma (e.g. sneezing, chiropractor manipulation, nose blowing, yoga), connective tissue disorders (e.g. Marfan’s, Ehlers-Danlos syndrome), genetic
  • Underlying arteriopathy likely exists in patients with spontaneous dissection or due to minor trauma
  • Major trauma: Elevated risk of carotid dissection with blunt or penetrating injuries involving the head, face, neck or thorax (and particularly in patients with skull base fractures, facial fractures, or TBI)

Pathophysiology

  • Intimal tear or direct bleeding in arterial wall -> intramural hematoma -> stenosis of arterial lumen or aneurysm formation -> formation of associated thrombi which may embolize distally to cause ischemia
  • If intracranial extension, may lead to subarachnoid hemorrhage
  • Most commonly occurs in ICA, 2cm cephalad from bifurcation of common carotid to skull base

Signs and Symptoms

  • Pain: Unilateral headache, neck pain, facial pain
  • Partial horner’s syndrome (ptosis and miosis without anhidrosis); sympathetic fibers associated with facial sweating are associated closely with external carotid artery and NOT the ICA
  • Cranial nerve palsies (CN XII most common), abnormal taste, pulsatile tinnitus
  • Ischemia: TIA/stroke with associated anterior circulation deficits (hemiparesis, hemisensory loss, aphasia, neglect, amaurosis fugax)
  • Patient with severe head/face/neck trauma that develops neurologic deficits

Diagnosis

  • First line: CTA neck or MR angiography depending on local availability/practice pattern
    • CTA generally used in patients with significant trauma
  • Doppler ultrasound: Highly operator dependent, relatively poor sensitivity if low grade stenosis. Should NOT be used as first line test
  • Angiography is traditional gold standard for diagnosis, but invasive and associated with complications
    • Only if initial screening study is negative but high suspicion for carotid dissection

Management

  • Spontaneous carotid dissection with evidence of acute ischemic stroke
    • Recent meta-analysis shows similar safety in giving thrombolysis in dissection vs non-dissection related strokes (retrospective data, no RCTs)
    • Thrombolysis CONTRAINDICATED if dissection is intracranial (risk of ICH) or involves the aorta (risk of aortic rupture)
  • Antiplatelet vs anticoagulation
    • Controversial; no published RCTs comparing either strategy (ongoing CADISS trial)
    • Currently, no evidence of superiority in antiplatelet vs anticoagulation strategy.  2011 AHA/ASA guidelines state relative efficacy of either strategy is unknown
    • Anticoagulation generally preferred if thrombus present in arterial lumen or severe stenosis
    • Antiplatelet preferred if contraindication to anticoagulation, NIHSS >15, large infarct, intracranial extension of dissection
  • No clear criteria for endovascular therapy (stent)
    • Considered when new ischemic symptoms develop despite being on antiplatelet or anticoagulation — “failure of medical therapy”
  • Continue antiplatelet or anticoagulation for 3 to 6 months and re-imaging is generally done within the time frame prior to discontinuing therapy

Pearls

  • Should always consider carotid/cervical dissection as cause of ischemic symptoms in patients that are young, lack risk factors for thrombotic/embolic stroke, or complaining of neck pain
  • Trauma patients with significant head/neck trauma and neurologic deficits, should evaluate for carotid or vertebral artery dissection
  • Consider carotid dissection in patients presenting with neck pain or headache that started in the context of activities that cause torsion or blunt trauma to neck

References/Further Reading

  • Patel RR, Adam R, et al. Cervical carotid artery dissection: current review of diagnosis and treatment Cardiology in Review. 2012 May-Jun; 20(3):145-52.
  • Zinkstok SM, Vergouwen MD, Engelter ST, et al. Safety and functional outcome of thrombolysis in dissection-related ischemic stroke: a meta-analysis of individual patient data. Stroke. 2011;42:2515–2520.
  • Debette S, Leys D. Cervical-artery dissections: predisposing factors, diagnosis, and outcomes. Lancet Neurol 2009; 8:668.
  • Engelter, ST, Brandt, T, et al. Antiplatelets versus anticoagulation in cervical artery dissection. Stroke. 2007;38:2605-2611.
Edited by Adaira Landry, MD

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