What are the symptoms of a left vertebral artery occlusion?

Symptoms of Left Vertebral Artery Occlusion

Left vertebral artery occlusion typically presents with symptoms of posterior circulation ischemia including dizziness, vertigo, diplopia, ataxia, bilateral sensory deficits, and syncope, which may be exacerbated by head turning or upper extremity exercise. 1

Common Clinical Manifestations

Neurological Symptoms

• Dizziness and vertigo (most common prodromal symptoms)
• Diplopia (double vision)
• Perioral numbness
• Blurred vision
• Tinnitus
• Ataxia (lack of coordination)
• Bilateral sensory deficits
• Syncope or pre-syncope
• Headache (often occipito-cervical) 2

Cerebellar Manifestations

• Ipsilateral cerebellar infarction (may be clinically silent initially) 3
• Cerebellar dysfunction (coordination problems, dysmetria)
• Gait disturbances

Brainstem Symptoms

• Wallenberg's syndrome (lateral medullary syndrome) 2
• Motor deficits
• Dysarthria (slurred speech)
• Dysphagia (difficulty swallowing)

Special Clinical Scenarios

Subclavian Steal Syndrome

When left vertebral artery occlusion is associated with subclavian artery stenosis proximal to the vertebral origin, symptoms may be:

• Aggravated by left arm exercise
• Associated with flow reversal in the vertebral artery
• Characterized by symptoms of vertebrobasilar insufficiency during upper limb exertion 1

Rotational Vertebral Artery Occlusion

• Symptoms reproducible with head rotation
• Typically occurs at C2 level
• May cause transient ischemic attacks with specific head positions 4

Extrinsic Compression

• Symptoms may be intermittent and position-dependent
• Can be caused by cervical osteophytes
• May be associated with waking symptoms if sleeping position compresses the artery 5

Progression Patterns

The onset of symptoms from vertebral artery occlusion can follow different patterns:

• Sudden onset (more common with middle/distal occlusions)
• Sudden onset preceded by prodromal symptoms
• Progressive onset (more common with bilateral vertebral artery occlusions) 6

Diagnostic Considerations

It's important to note that symptoms of vertebrobasilar insufficiency can be caused by other conditions, including:

• Cardiac arrhythmias
• Orthostatic hypotension
• Vestibular disorders 1, 7

Mortality Risk

Contrary to common belief, vertebral artery occlusion carries a significant mortality risk. Historical data suggests mortality rates of approximately 25%, with distal and extensive occlusions carrying higher risk than proximal, well-compensated occlusions 2.

Clinical Pitfalls to Avoid

1. Misattribution of symptoms: Many symptoms of vertebral artery occlusion are nonspecific and can be caused by other conditions.

2. Failure to consider positional triggers: Not asking about position-dependent symptoms may miss intermittent occlusion.

3. Overlooking silent cerebellar infarction: Some patients may have cerebellar infarcts without obvious clinical manifestations initially.

4. Inadequate vascular imaging: Standard angiography may miss dynamic occlusions that occur only with certain head positions.

5. Focusing only on the vertebral artery: Not evaluating the entire posterior circulation may miss additional pathology that contributes to symptoms.

The clinical presentation of left vertebral artery occlusion requires careful evaluation with appropriate neuroimaging, as symptoms may overlap with other conditions and the consequences of missed diagnosis can be severe.