Vertebral Artery Dissection

What happens in a dissection

The wall of an artery has three layers. In a dissection, a small tear in the inner layer allows blood to enter the wall and split the layers, forming a bruise (intramural hematoma). This can:

• narrow or block the artery
• form a blood clot at the tear, which can break off and block an artery in the brain, causing a stroke
• occasionally form a bulge (pseudoaneurysm)

The vertebral arteries supply the brainstem, cerebellum and back of the brain, so strokes from vertebral dissection cause balance, vision and coordination problems. A similar tear in the carotid artery at the front of the neck is a carotid artery dissection, which can cause stroke in the same way as carotid artery stenosis.

Causes and risk factors

Many dissections happen spontaneously or after minor triggers:

• Minor neck trauma or sudden twisting: sports, falls, whiplash, roller coasters, yoga
• Chiropractic neck manipulation: an association has been reported, though whether manipulation causes dissections or people with early dissection pain seek treatment is debated
• Prolonged coughing, vomiting or sneezing
• Major trauma to the neck
• Tears can also occur in other arteries, such as the aorta (aortic dissection), but these are separate conditions
• Connective tissue disorders: Ehlers-Danlos syndrome (vascular type), Marfan syndrome, fibromuscular dysplasia
• Recent infection, migraine, and high blood pressure have also been associated

Symptoms

Pain

• New pain in the back of the neck or the back of the head, usually one-sided
• Often described as unusual or different from previous headaches
• May come hours to days before stroke symptoms

Stroke or TIA symptoms (posterior circulation)

• Dizziness or vertigo
• Unsteadiness and difficulty walking
• Double vision or loss of vision on one side
• Slurred speech
• Difficulty swallowing
• Nausea and vomiting
• Numbness of the face or body, or weakness
• Clumsiness of one arm or leg

Some people have only neck pain and headache, without stroke. Brief, fully resolving symptoms are a transient ischemic attack (TIA) and need the same urgent assessment.

Diagnosis

• Neurological examination
• CT angiography or MR angiography of the head and neck: show narrowing, a flap, a "string sign" or intramural blood
• MRI of the brain: detects stroke
• Catheter angiography occasionally, if other tests are unclear

Treatment

• Antiplatelet medicine (such as aspirin) or anticoagulants (blood thinners) to prevent clots forming and traveling to the brain. Studies have found both approaches similarly effective for most people, and the choice depends on individual factors. Treatment usually continues for 3 to 6 months.
• Acute stroke treatment: clot-busting medicine or clot removal (thrombectomy) for eligible people, as with other strokes.
• Endovascular stenting or surgery: rarely, for people who continue to have strokes despite medicine or have large pseudoaneurysms.
• Pain relief and avoiding further neck strain while healing.
• Rehabilitation after stroke.

Outlook

Most dissections heal over 3 to 6 months, with the artery returning to normal or nearly normal. Most people without a major stroke recover well. Recurrence is uncommon but more likely in people with connective tissue disorders. People who have had a stroke may need rehabilitation and have lasting effects depending on its size and location.

Prevention and after a dissection

• Avoid high-velocity neck manipulation and extreme neck movements, at least while healing, and discuss future activities with your doctor.
• Control blood pressure and do not smoke.
• Seek prompt care for new neck pain with neurological symptoms.

Frequently asked questions

What are the symptoms of vertebral artery dissection?

The most common symptom is new pain in the back of the neck or head, usually on one side. This may be followed by stroke symptoms such as dizziness, vertigo, unsteadiness, double vision, slurred speech, difficulty swallowing, nausea or numbness. These need emergency care.

What causes vertebral artery dissection?

Many occur spontaneously or after minor neck trauma or sudden movements, such as sports, falls, whiplash, coughing or vomiting. Neck manipulation has been associated with dissection. Connective tissue disorders such as Ehlers-Danlos syndrome increase the risk.

Can vertebral artery dissection heal on its own?

Yes, most dissections heal within 3 to 6 months. Blood-thinning or antiplatelet medicines are usually given during this time to prevent clots and stroke. Follow-up imaging checks healing.

Is vertebral artery dissection a stroke?

Not always. A dissection is a tear in the artery. It can cause a stroke if it blocks blood flow or releases a clot to the brain. Some people have only neck pain and headache. Prompt treatment reduces the risk of stroke.