CBL: Arterial Dissection

Learning Objectives

• Recognize that arterial dissection can follow trauma or occur spontaneously.
• Identify vascular imaging (CTA/MRA/angiography) as required for diagnosis.
• Review antithrombotic therapy options for treatment.

Vignette

A 17-year-old hockey player is struck on the left neck by a puck with immediate pain. Minutes later, throbbing pain radiates from the left neck to the eye with difficulty focusing from the left eye; she stops playing. No numbness or weakness. Headache persists despite ibuprofen/acetaminophen. In the ED, the left pupil is smaller and the left eyelid slightly droopy.

Examination

BP 131/82, HR 82. Healthy-appearing, alert. Left pupil smaller than right with mild left ptosis (partial Horner). Soft bruit over left carotid; superficial neck contusion. EOMI; facial sensation and expression normal; hearing intact; shoulder and tongue movements normal. Remaining neurologic exam normal.

Localization & Neuroanatomy

Partial Horner syndrome (ptosis, miosis) suggests disruption of sympathetic pathways to the eye. Ascending sympathetic fibers form a plexus around the internal carotid artery; trauma to the neck can injure the carotid wall (dissection) and the perivascular sympathetic plexus. Alternative sites include brainstem, spinal cord, or oculomotor nerve, but the history and neck findings localize to the carotid.

Diagnosis

Dissection involves a tear in the arterial intima with blood tracking between layers, creating a false lumen that can narrow flow, cause pain, or compress adjacent nerves. Some patients have predisposing arteriopathies (e.g., fibromuscular dysplasia); dissections may also occur spontaneously. Vascular imaging confirms the diagnosis: duplex ultrasound, CTA, MRA of head/neck, or catheter angiography.

Treatment

Management typically includes antithrombotic therapy (e.g., aspirin or anticoagulation such as heparin/warfarin) and analgesia. Most cases resolve over time; consider this diagnosis with new focal neurologic signs after neck pain/trauma. Urgent evaluation is warranted given risk of ischemic stroke.

Teaching Points

• Neck trauma + ipsilateral head/eye pain + partial Horner syndrome strongly suggests carotid dissection.
• Diagnosis requires vascular imaging (CTA/MRA/angiography), not noncontrast head CT alone.
• Early antithrombotic therapy reduces thromboembolic risk; many dissections heal spontaneously.

References

1. Module adapted from provided teaching text on cervical arterial dissection, highlighting presentation, imaging diagnosis, and antithrombotic management.