What is the management of a suspected vertebral artery injury following whiplash?

Management of Suspected Vertebral Artery Injury Following Whiplash

If clinical or imaging findings suggest vertebral artery injury after whiplash, obtain CTA head and neck with IV contrast or MRA neck (with or without contrast) immediately, as these are equivalent first-line vascular imaging modalities with 94% sensitivity compared to 70% for ultrasound. 1, 2

Initial Clinical Assessment

Evaluate specifically for posterior circulation ischemia symptoms that indicate vertebral artery involvement 1:

• Vertigo and dizziness (present in 25-50% of whiplash cases) 3
• Ataxia and incoordination
• Diplopia and visual field defects
• Perioral numbness
• Bilateral sensory deficits
• Cranial nerve deficits

Critical pitfall: Vertebral artery injuries can present with delayed neurologic complications—fatal basilar thrombotic embolus has occurred up to 2 months post-whiplash, and dissection has been detected 24 days after minor collision. 4, 5

Imaging Strategy

First-Line Vascular Imaging

CTA head and neck with IV contrast is usually appropriate as the next imaging study when clinical or imaging findings suggest arterial injury 1:

• Sensitivity: 41-98% for cervical arterial injury
• Specificity: 81-100%
• Can be performed simultaneously with cervical spine CT
• Lower complication rate than conventional angiography 1

MRA neck is an equivalent alternative 1:

• Sensitivity: 75% for blunt cerebrovascular injury
• Specificity: 67%
• Superior for detecting intramural hematoma compared to CTA or conventional angiography 1
• Use contrast-enhanced 3D time-of-flight imaging with axial T1-weighted fat-suppressed sequences to identify intramural hematoma 1

When to Escalate to Conventional Angiography

Catheter-based angiography remains the gold standard but carries 1-2% risk of iatrogenic arterial dissection and stroke 1:

• Required before revascularization procedures (neither MRA nor CTA reliably delineates vertebral artery origins) 1, 6
• When noninvasive imaging fails to define location or severity of stenosis in revascularization candidates 2
• Most injuries missed on CTA/MRA are low-grade (79-100%) 1

Medical Management

Acute Phase (Evidence of Thrombus)

Anticoagulation is generally recommended for at least 3 months when angiographic evidence shows thrombus in the extracranial vertebral artery, regardless of whether thrombolytic therapy is used initially 1, 2, 6:

• Heparin followed by warfarin
• Anatomic healing occurs in 72-100% of dissection cases 6

Standard Medical Therapy

Aspirin 75-325 mg daily is first-line antiplatelet therapy for vertebral artery injury 2, 6:

• If aspirin contraindicated: clopidogrel 75 mg daily or ticlopidine 250 mg twice daily 2
• Aspirin plus extended-release dipyridamole has shown benefit in reducing vertebrobasilar territory stroke/TIA 2, 6

Critical pitfall: Avoid routine dual antiplatelet therapy (aspirin + clopidogrel) as hemorrhage risk outweighs benefit 6

Clinical Outcomes Data

Vertebral artery injuries occur in approximately 24% of major cervical spine trauma cases on MRA 7:

• Neurologic sequelae attributable to vertebral artery injury are rare (posterior circulation stroke rate <2%) 8
• No significant differences in short-term outcomes between anticoagulation and antiplatelet therapy 8
• Grade of injury or vertebral artery segment does not correlate with morbidity 8

Revascularization Considerations

Revascularization should be considered ONLY when medical therapy fails to control recurrent ischemic symptoms 2, 6:

Endovascular Treatment Risks

• Death: 0.3%
• Periprocedural neurological complications: 5.5%
• Posterior stroke: 0.7%
• Restenosis: 26% at mean 12-month follow-up 2, 6

Surgical Options (when endovascular not feasible)

• Trans-subclavian vertebral endarterectomy
• Transposition of vertebral artery to ipsilateral common carotid artery
• Reimplantation of vertebral artery 2

Follow-Up Protocol

Monitor for recurrent symptoms and consider serial noninvasive imaging to assess progression 2:

• Continue indefinite antiplatelet therapy after acute phase
• Aggressive cardiovascular risk factor modification 6
• Follow-up imaging demonstrates injury resolution or stability in most cases 8

Special Consideration for Whiplash-Associated Disorders

Imaging has little usefulness in diagnosing and predicting prognosis of whiplash-associated disorders (WAD) without vascular injury 1:

• MRA/CTA have no role in WAD assessment absent clinical suspicion for vascular injury 1
• Diagnosis and prognosis of WAD rely almost exclusively on clinical and psychosocial data 1
• Exercise and cervical spine mobilization are effective for reducing WAD symptoms once instability is excluded 1