High-Risk Neurovascular Scenarios
Rationale for Emergency Evaluation
- A patient with high-grade stenosis in the V4 segment of the vertebral artery and presenting with intermittent dizziness should be immediately referred to the emergency department for urgent evaluation and management due to the high risk of stroke, as vertebrobasilar arterial stenosis is associated with multiple ischemic episodes and a higher risk of early recurrent stroke 1, 2
- Dizziness is a recognized symptom of vertebral artery disease that can indicate compromised vertebrobasilar perfusion or potential atheroembolism, and intermittent symptoms may represent transient ischemic attacks (TIAs), which carry a high risk of stroke - up to 13% in the first 90 days 1, 2, 3
Clinical Significance of the Imaging Findings
- V4 segment stenosis affects the intracranial portion of the vertebral artery, which has fewer collaterals and poses a higher risk for posterior circulation stroke, and vertebral artery atherosclerosis may be the causative basis for approximately 20% of posterior circulation strokes 1
Diagnostic Workup Needed in the ED
- A complete neurovascular assessment including detailed neurological examination and comprehensive vascular imaging is necessary to better characterize the extent of disease, and catheter-based angiography may be required for definitive assessment of vertebral artery origins and for planning potential interventions 1, 3
- Cardiac evaluation to rule out cardiac sources of embolism is also essential, as these patients have a high rate of structural heart disease 4
Treatment Considerations
- Immediate initiation of antithrombotic therapy is likely warranted, and for symptomatic vertebral artery stenosis, medical management includes antiplatelet therapy, statins, and risk factor modification, according to the American Heart Association 1, 2, 4, 5
- Revascularization options (surgical or endovascular) may need to be considered based on the severity and symptomatology, and the management approach must be coordinated with a multidisciplinary team including neurology, neurosurgery, and interventional radiology 1, 5
Pitfalls to Avoid
- Delaying evaluation of intermittent dizziness in the setting of known high-grade vascular stenosis can lead to preventable strokes, and failing to recognize that dizziness may be the only presenting symptom of posterior circulation ischemia can also have devastating consequences 1, 2, 3