What are the symptoms of vertebral artery occlusion?

Symptoms of Vertebral Artery Occlusion

Vertebral artery occlusion typically presents with dizziness, vertigo, diplopia, perioral numbness, blurred vision, tinnitus, ataxia, bilateral sensory deficits, and syncope, which can significantly impact mortality and morbidity if not properly identified and treated. 1

Common Clinical Presentation

Vertebral artery occlusion manifests through a constellation of symptoms affecting the posterior circulation of the brain:

• Primary symptoms:

  • Dizziness and vertigo
  • Diplopia (double vision)
  • Perioral numbness
  • Blurred vision
  • Tinnitus
  • Ataxia (lack of coordination)
  • Bilateral sensory deficits
  • Syncope (fainting) 2

• Less common but significant symptoms:

  • Headache (often occipito-cervical)
  • Nausea and vomiting
  • Hearing loss
  • Slurred speech
  • Imbalance
  • Unilateral extremity weakness 1, 3

Symptom Patterns Based on Occlusion Location

The clinical presentation varies depending on the location of the occlusion:

1. Proximal vertebral artery occlusion:

   • Often better tolerated due to collateral circulation
   • May be asymptomatic if adequate compensation exists 3

2. Mid-portion vertebral artery occlusion:

   • Symptoms commonly provoked by head turning
   • Transient symptoms that resolve when head returns to neutral position 4, 5, 6

3. Distal vertebral artery occlusion:

   • More likely to cause cerebellar, vestibular, or cerebello-vestibular strokes
   • May present with Wallenberg's syndrome (lateral medullary syndrome) 3

4. Bilateral vertebral artery occlusion:

   • Higher risk of progressive stroke
   • More severe and persistent symptoms 7

5. Occlusion with basilar artery involvement:

   • Can present with specific syndromes:
     • Top of the basilar syndrome: somnolence, peduncular hallucinosis, convergence nystagmus
     • Mid-basilar occlusions: cranial nerve deficits
     • Proximal basilar occlusions: motor deficits, bulbar symptoms 1

Diagnostic Challenges

A critical pitfall in diagnosing vertebral artery occlusion is that these symptoms can mimic other conditions:

• Cardiac arrhythmias
• Orthostatic hypotension
• Vestibular disorders 2

Additionally, the NIHSS (National Institutes of Health Stroke Scale) has limitations in detecting posterior circulation strokes, as it focuses more on limb and speech impairments than on cranial nerve lesions. Patients with posterior circulation large vessel occlusion can have an NIHSS score of 0, presenting only with headache, vertigo, and nausea 1.

Onset Patterns

The onset of symptoms can follow different patterns:

• Sudden onset: More common with middle and distal basilar artery occlusions
• Sudden onset with prodromal symptoms: Often preceded by vertigo, nausea, and headache in the 2 weeks before the stroke
• Progressive onset: More common with bilateral vertebral artery occlusions 7

Clinical Significance

Without proper treatment, posterior circulation strokes have a mortality range from 45% to 86%, highlighting the importance of prompt recognition of these symptoms 1. The mortality rate in vertebral artery occlusion can reach 25%, contrary to the common belief that it is always benign 3.

When evaluating patients with these symptoms, imaging studies such as CTA and contrast-enhanced MRA have higher sensitivity (94%) and specificity (95%) than ultrasonography (sensitivity 70%) for diagnosing vertebral artery occlusion 1.