II. Definitions
- Cervical Artery Dissection (Cervicocerebral Arterial Dissection)
- Extracranial Arterial Dissection includes carotid dissection and Vertebral Dissection
III. Epidemiology
- Cervical Artery Dissection (Carotid Artery and Vertebral Artery) are uncommon overall
- Overall: <2% of ischemic Cerebrovascular Accidents (2.6 to 2.9 per 100,000)
- Young Patients (age <45 years): 10-25% of ischemic Cerebrovascular Accidents
IV. Pathophysiology
- Vessel intima tear or vasa vasorum rupture
- Vessel wall media develops localized bleeding
- Blood within vessel wall separates layers resulting in a false lumen
- Aneurysm may form if vessel wall Hematoma expands toward adventitia (sub-adventitial dissection)
- Vessel lumen may be narrowed if vessel wall expands towards intima
V. Types
- Carotid Artery Dissection (most common)
- Vertebral Artery Dissection
VI. Risk Factors
-
Genetic Predisposition, Typically Connective Tissue Disorder (spontaneous dissection)
- Ehlers-Danlos Syndrome Type IV
- Marfan's Syndrome
- Autosomal Dominant Polycystic Kidney Disease
- Osteogenesis Imperfecta Type 1
-
Coronary Artery Disease Risk Factors
- Hypertension
- Atherosclerosis
- Other possible risk factors
- Migraine Headache with aura
- Respiratory infection
- Autumn peak in dissection Incidence also may suggest infectious contributing factors
VII. Causes
- Spontaneous Cervical Artery Dissection
- Idiopathic (non-Traumatic)
- May be associated with risk factors as above
- Average age 44 years (+/- 13 years)
- Trauma
- Hyperextension or rotation of the neck (esp. if sudden)
- Yoga
- Painting ceiling
- Coughing, Sneezing or Vomiting
- Procedural Sedation
VIII. Findings
- See Carotid Artery Dissection
- See Vertebral Artery Dissection
- Findings are specific to distribution of dissection
- Unilateral Headache (68%)
- Neck Pain (39%)
- Facial Pain (10%)
IX. Differential Diagnosis
X. Imaging
- CT Angiogram Head and Neck
- Optimal in Vertebral Artery Dissection
- High efficacy when compared with DSA in blunt cervical Trauma
- Double lumen sign (false and true lumen)
- Flame-like taper of vessel lumen
- MRI/MRA Head and Neck (T1 axial cervical with fat saturation)
- Overall preferred dissection imaging, esp. in Carotid Artery Dissection
- Able to identify intramural Hematoma
- Digital Subtraction Angiography (DSA)
- Considered the gold standard, but invasive and CTA is typically performed instead
XI. Complications
- Cerebrovascular Infarction (up to 70% of cases)
- Mechanisms
- Endothelial injury triggers the coagulation cascade with Thromboembolism (85% of cases)
- Vessel stenosis with watershed region ischemia
- Morel (2012) Stroke 43(5): 1354-61 [PubMed]
- May account for up to 20-25% of CVA in young patients <45 years old
- Typically occurs in the first 2 weeks of Cervical Artery Dissection
- CVA is more common in Vertebral Artery Dissection (esp. extracranial)
- Functional independence at 3 months in 75% of Cerebrovascular Accident cases
- Mechanisms
-
Cerebral Vessel Stenosis (e.g. Carotid Artery Stenosis)
- Initially may be symptomatic
- Typically resolves in first 6 months
- Not associated with significant increased Cerebrovascular Accident risk after initial dissection
- Pseudoaneurysm
- Decreased risk of pseudoaneurysm enlargement with Antiplatelet Therapy and Anticoagulation
- Pseudoaneurysms completely resolve in 30% of cases
- Pseudoaneurysms persist but remain a stable size in 56% despite vessel otherwise healing
- Pseudoaneurysms enlarge in 13% cases and may become symptomatic
- Nonischemic Symptoms in 14% (Headache, Neck Pain, Cranial Nerve palsy, Horner Syndrome)
- Ischemic Symptoms in 3% (typically Transient Ischemic Attack; recurrent CVA is rare)
- Pseudoaneurysm risk of future rupture 1% (esp. intracranial vessels lacking external elastic lamina)
- Large pseudoaneurysms >10 mm diameter often undergo surgery (clipping or endovascular stent)
- Decreased risk of pseudoaneurysm enlargement with Antiplatelet Therapy and Anticoagulation
- Recurrent Cervical Artery Dissection
- Occurs in up to 7% of patients within 7 years
XII. Management
- Consult Neurology and Neurosurgery
-
Cerebrovascular Accident
- Systemic CVA Thrombolysis in acute CVA (<4.5 hours) as in non-dissection acute CVA (consult stroke neuro)
- In addition to CVA Thrombolytic Contraindications, Thrombolytics are also avoided in aortic arch involvement
- For NIHSS >=6 with persistent deficit, consider intervention (mechanical thrombectomy, Angioplasty, stenting)
- Antiplatelet Agents or Anticoagulation
- Management is controversial
- Aspirin may be as effective as Anticoagulation in Cervical Artery Dissection
XIII. References
- Hussein and Leiman (2022) Crit Dec Emerg Med 36(8): 4-8
- Marcolini and Swaminathan in Herbert (2021) EM:Rap 21(3): 9-11
- Blum (2015) Arch Neurosci 2(4) +PMID:26478890 [PubMed]
- Shafafy (2017) J Spine Surg 3(20): 217-25 +PMID: 28744503 [PubMed]