Can head or neck trauma cause acute ischemic stroke?

Can Head or Neck Trauma Cause Acute Ischemic Stroke?

Yes, head or neck trauma can definitively cause acute ischemic stroke, most commonly through traumatic arterial dissection (particularly vertebral artery dissection), with stroke risk highest within the first two weeks after injury. 1, 2, 3

Mechanism and Timing

Traumatic vascular injury, especially vertebral artery dissection, is the primary mechanism by which trauma causes ischemic stroke. 1 The vertebral arteries are particularly vulnerable to injury from neck trauma or even minor head trauma during athletic activities. 4, 5

Critical Time Window

• Stroke risk is elevated for approximately 2 weeks following trauma, with the highest risk in the first 15 days. 3
• In one population study, 37% of trauma-related strokes occurred on the day of trauma, but all occurred within 15 days. 3
• This delayed onset provides a window for stroke prevention through early vascular imaging and intervention. 3

Diagnostic Challenges

A major pitfall is that stroke diagnosis is frequently delayed in trauma patients, averaging 1.8 days after presentation, because neurologic deficits may be obscured by concurrent injuries. 6

Key Diagnostic Considerations:

• In approximately 25% of cases, initial cerebrovascular angiography at the time of trauma shows no vascular abnormality, yet stroke still occurs. 3
• None of the trauma patients in one study were diagnosed with acute ischemic stroke on admission despite ultimately having confirmed strokes. 6
• Competing injuries (skeletal trauma, multisystem trauma) often distract from neurologic assessment. 6

Recommended Imaging Approach

The American College of Radiology recommends vascular imaging (CTA or MRA of head and neck) when there is suspicion of traumatic vascular injury in patients presenting with neurologic symptoms after trauma. 1

Imaging Algorithm for Trauma Patients with Neurologic Symptoms:

Initial imaging:

• Non-contrast CT head to assess for hemorrhage, mass effect, and herniation requiring emergent neurosurgical intervention. 1
• CTA head and neck (preferred) or MRA head and neck to evaluate for vertebral artery dissection and other vascular injuries. 1

Advanced imaging:

• MRI head is more sensitive than CT for detecting small cerebellar infarcts from traumatic dissection, diffuse axonal injury, and small hemorrhages that may be missed on CT. 1

Specific Injury Patterns:

• Head and neck injuries carry the highest stroke risk (OR 4.1 and 5.6 respectively) after adjusting for trauma severity. 3
• Vertebral artery dissections are most commonly extracranial, making imaging of both head and neck essential rather than either alone. 1

Clinical Context

Trauma-related stroke occurs across all age groups but is particularly important to recognize in children and young adults, where it may result from even minor athletic injuries. 4

Incidence:

• In pediatric ataxia cases, trauma accounts for approximately 5% of presentations. 1, 7
• In a trauma cohort study, 5.7% of trauma patients had acute ischemic stroke. 6
• Population-based incidence is 4.0 per 100,000 trauma encounters within 4 weeks. 3

High-Risk Scenarios:

• Motor vehicle collisions are the most frequent mechanism (73% in one series). 6
• Multisystem trauma increases stroke risk, though head and neck injuries remain the strongest independent predictors. 3
• Athletic activities causing even trivial head or neck trauma can result in stroke. 4

Management Implications

The delayed onset of stroke after trauma creates an opportunity for prevention through early detection of vascular injury. 3 However, routine craniocervical vascular imaging at the time of trauma presentation in high-risk patients (head/neck injury, neurologic symptoms) could facilitate early diagnosis and intervention. 6

Management of traumatic vertebral artery injury depends on radiological grade and clinical severity, with high-grade symptomatic injuries treated endovascularly and asymptomatic or low-grade injuries managed with anticoagulation when not contraindicated. 5

Critical Pitfall to Avoid:

Do not assume normal initial vascular imaging excludes stroke risk—approximately one-quarter of trauma-related stroke cases had normal cerebrovascular angiography at the time of trauma. 3 This emphasizes the need for clinical vigilance during the 2-week high-risk period even with initially normal imaging.