By Dr. Abdolghader

Carotid and vertebral dissection: recognition, imaging, and early treatment

 Clinical Scenario to Anchor the Learning

Case :

35-year-old woman presents with right-sided neck pain and a droopy right eyelid. She thought she pulled something during yoga 2 days ago. Now she’s got a weird headache behind her eye and feels “foggy.”

Neuro exam is otherwise non-focal. CT head is normal.

What should trigger you?

Painful new ptosis should prompt a careful pupil examination and urgent vascular assessment. Ptosis alone does not establish Horner syndrome; look for ipsilateral miosis, more apparent in dim light. This case warrants urgent CTA head and neck or an appropriate MRI/MRA pathway despite the normal head CT. No vascular imaging result or outcome is supplied.

 STEP 1: Know When to Suspect Dissection — Don’t Miss These Red Flags

 Key Clinical Triggers:

• New, unusual unilateral head or neck pain, especially with an ipsilateral partial Horner syndrome or cranial nerve deficit.
• Transient monocular visual loss, focal weakness, aphasia, or other cerebral ischemic symptoms.
• Posterior head/neck pain with diplopia, dysarthria, ataxia, or a concerning vestibular presentation. Vertigo alone is nonspecific.
• Pain can precede ischemia or occur alone; a normal initial neurologic examination is not exclusionary. Dissection also occurs in older adults. Pain-only cohort.

Cervical dissection can occur spontaneously or after minor mechanical triggers. Ask about recent neck movement or trauma, but neither a minor mechanism nor its absence excludes dissection.

 STEP 2: Understand the Pathophysiology (Simple)

Blood within the arterial wall can narrow the lumen and create a surface for thrombus. Embolization then threatens downstream brain or retinal tissue; severe narrowing can also reduce flow. Outward expansion may affect nearby nerves.

Around the internal carotid artery, sympathetic injury explains ipsilateral ptosis and miosis, often without facial anhidrosis. Local pain or Horner syndrome may therefore precede a hemispheric deficit. Carotid dissection cohort.

 STEP 3: History + Exam – What to Ask and Look For

Establish pain onset, last known well, transient symptoms, recent trauma or neck movement, and antithrombotic use. Examine pupils in light and dark, eye movements, visual fields, cranial nerves, limb coordination, gait when safe, strength, and sensation. Repeat the examination if symptoms evolve.

STEP 4: Localize the Dissection – CAD vs VAD

Carotid dissection often produces anterior neck, facial, or orbital pain with retinal or hemispheric ischemia; lower cranial nerve palsies can occur. Vertebral dissection more often causes posterior neck/occipital pain with brainstem or cerebellar ischemia. These are localization clues, not diagnostic rules. Carotid cohort; vertebral cohort.

STEP 5: Imaging – What to Order and Why

Select brain and cervical vascular imaging according to the presentation and stroke pathway:

• Non-contrast CT head – assess hemorrhage and established infarction when indicated; a normal early CT does not exclude evolving ischemia or cervical artery dissection.
• CTA head and neck is a rapid, practical ED vascular study; MRI/MRA is another reasonable option. Findings that may support dissection include:
  • Tapering stenosis (“string sign”)
  • Intimal flap
  • Pseudoaneurysm

If CTA is negative or inconclusive and clinical concern persists:

• Discuss complementary MRI brain and MRA with fat-suppressed vessel-wall sequences with neuroradiology/stroke specialists. CTA and MRI/MRA answer partly different questions; neither a technically limited study nor a reassuring report should end evaluation when the clinical picture remains discordant. Comparative imaging study.
• Ultrasound cannot reliably exclude dissection, particularly with local symptoms alone or poorly visualized arterial segments. In a cohort with isolated Horner syndrome, nearly one-third had a normal initial ultrasound. Ultrasound study.

More than one cervical artery may be involved. In the CADISP cohort, 149 of 983 patients (15.2%) had multiple dissections; this is not a bilateral-only rate. Assess the cervical vascular study comprehensively, including both sides. CADISP study.

 STEP 6: Treatment – Practical ED Management

First identify ischemic stroke and activate the stroke pathway. Record last known well, check glucose, obtain urgent brain/vascular imaging, and assess reperfusion eligibility. Dissection-specific secondary prevention must not delay an eligible reperfusion treatment.

• For extracranial dissection, select antiplatelet therapy or anticoagulation with the stroke team. Review infarct burden, intracranial bleeding, intradural extension, embolic risk, and reperfusion timing. There is no universal anticoagulation requirement.
• The AHA suggests an individualized antithrombotic course, generally 3–6 months, with subsequent decisions guided by clinical and imaging review. This is not an automatic stop date. AHA statement.

→ Antiplatelet and anticoagulant strategies are both options; superiority remains uncertain and treatment should be individualized. The evidence does not establish equivalence: CADISS found no significant treatment difference, TREAT-CAD did not establish aspirin’s non-inferiority, and pooled randomized data showed no significant primary-composite difference despite a secondary stroke outcome favoring anticoagulation. CADISS; TREAT-CAD; 2024 individual-patient-data analysis.

Do not routinely combine an anticoagulant with an antiplatelet without a separate indication. A short dual-antiplatelet course for selected minor stroke/TIA is a different strategy and requires a stroke-team plan. ESO guideline.

Reperfusion is a separate decision:

• Extracranial cervical dissection alone does not exclude IV thrombolysis in an otherwise eligible ischemic stroke. Assess mechanical thrombectomy separately when an eligible large-vessel occlusion is present. Intracranial/intradural extension or hemorrhage changes the risk assessment.
• Known or suspected aortic arch dissection is different: do not administer IV thrombolysis. Escalate urgently through the appropriate stroke and aortic emergency pathways. AHA/ASA 2026 guideline.

 BP Goals:

Use the blood-pressure pathway appropriate to ischemic stroke and the planned reperfusion treatment. Avoid hypotension and reflexive aggressive lowering that could worsen flow beyond a stenosed artery. AHA/ASA 2026 guideline.

STEP 7: Disposition

Obtain urgent stroke-specialist assessment. Evolving neurologic symptoms require monitored admission and escalation according to severity. For a stable patient without infarction, admission, observation, or carefully arranged discharge depends on imaging, treatment needs, and reliable rapid follow-up. Recurrent ischemia despite appropriate therapy or an expanding compressive dissecting aneurysm warrants multidisciplinary review; aneurysm size alone does not mandate intervention. ESO guideline.

 STEP 8: Pitfalls to Avoid

• Do not dismiss dissection because the patient is young, the trigger was minor, or the initial CT head was normal.
• Do not wait for a complete triad, and do not equate isolated headache or dizziness with a diagnosis.
• If clinical concern remains after imaging, reconcile the discrepancy with the stroke team before discharge.

Before discharge

Document the treatment and follow-up plan.

Confirm medication instructions and follow-up. Return immediately for new neurologic symptoms or sudden worsening headache. Discuss avoiding neck injury and forceful manipulation; a preceding movement does not prove causation.

 ED Checklist Summary

• Recognize a concerning combination of pain, local nerve findings, or cerebral/retinal ischemia.
• Obtain appropriate brain and cervical vascular imaging; reassess discordant negative tests.
• Prioritize stroke reperfusion eligibility, then individualize antithrombotic therapy.
• Agree monitoring, disposition, and follow-up with the stroke team.

📚 References

• Yaghi S, et al. Treatment and Outcomes of Cervical Artery Dissection in Adults. AHA scientific statement. Stroke. 2024;55:e91–e106. Primary statement.
• Antithrombotic evidence: TREAT-CAD 2021; randomized individual-patient meta-analysis 2024; TREAT-CAD six-month extension 2025. The extension does not establish a universal stopping point at 3 months.
• Markus HS, et al. CADISS randomized clinical trial final results. JAMA Neurology. 2019. Primary study.
• AHA/ASA 2026 Guideline for the Early Management of Acute Ischemic Stroke. Current guideline.