Management of Patient with Left-Sided Weakness, No Stroke, and Hypoplastic/Congenital Vertebrobasilar System
For patients with left-sided weakness and a hypoplastic/congenital vertebrobasilar system where stroke has been ruled out and no neurointervention is indicated, medical management with antiplatelet therapy, aggressive risk factor modification, and monitoring for symptom progression is the recommended approach.
Understanding the Condition
A hypoplastic or congenital vertebrobasilar system refers to an anatomical variation where the vertebral and/or basilar arteries are underdeveloped or have congenital anomalies. This condition:
- Is usually discovered incidentally during imaging studies 1
- May be asymptomatic due to collateral circulation through the circle of Willis 1
- Can sometimes lead to clinical symptoms under certain circumstances
Diagnostic Considerations
When a patient presents with left-sided weakness and imaging reveals a hypoplastic/congenital vertebrobasilar system:
- The absence of acute stroke on imaging indicates this is not an acute vascular event
- "No neurointervention indicated" means invasive procedures (stenting, angioplasty, surgery) are not warranted
- Symptoms may be related to:
- Transient ischemia due to insufficient collateral flow
- Hemodynamic compromise during certain activities or positions
- Non-vascular causes that coincide with the anatomical finding
Management Approach
1. Medical Management
Antiplatelet Therapy:
- First-line therapy for patients with vertebrobasilar insufficiency without evidence of acute thrombus 2
- Options include aspirin, clopidogrel, or combination therapy with aspirin plus dipyridamole 2
- The ESPS-2 trial showed that vertebrobasilar territory events occurred in 5.7% of patients treated with aspirin plus dipyridamole compared to 10.8% with placebo 2
Risk Factor Modification:
- Aggressive blood pressure control
- Lipid management
- Diabetes management (if applicable)
- Smoking cessation
- Weight management
2. Monitoring and Follow-up
- Regular neurological assessments to monitor for symptom progression
- Follow-up imaging may be warranted to assess for any changes in the vertebrobasilar system
- Evaluate for development of aneurysms, which can occur due to hemodynamic changes in collateral vessels 1
3. When to Consider Intervention
Although intervention is not currently indicated, be aware of situations that might warrant reconsideration:
- Development of recurrent symptoms despite optimal medical therapy 2
- Evidence of progressive vertebrobasilar insufficiency
- Development of hemodynamically significant stenosis in addition to the congenital anomaly
Important Considerations and Caveats
Collateral Circulation: Most patients with congenital vertebrobasilar anomalies develop sufficient collateral circulation, which explains why many remain asymptomatic 1
Distinguish from Acquired Stenosis: Congenital hypoplasia differs from atherosclerotic disease in management approach and prognosis 3
Avoid Unnecessary Interventions: There is little evidence from randomized trials that endovascular management is superior to best medical management for vertebral artery disease 2
Surgical Risk: Operations on the vertebral arteries carry significant risks, with mortality rates of 3-12% and neurological complication rates of 22-55% 2
Endovascular Risk: Endovascular procedures for vertebral artery disease carry risks of periprocedural neurological complications (5.5%) and restenosis (26%) 2
Conclusion
The finding of a hypoplastic/congenital vertebrobasilar system in a patient with left-sided weakness but no stroke represents an anatomical variant that requires medical management rather than intervention. Focus on antiplatelet therapy and risk factor modification while monitoring for any symptom progression that might warrant reassessment of the management approach.