What is the likelihood that the patient's left-sided face and arm weakness, with imaging findings of a right distal superficial internal carotid artery (ICA) occlusion, is directly related to the trauma from a fall off an 8-foot ladder 8 years prior?

Relationship Between Fall from Ladder and Delayed Carotid Artery Occlusion

The patient's current neurological symptoms and carotid artery occlusion are unlikely to be directly related to the ladder fall that occurred 8 years ago. 1

Assessment of Temporal Relationship

Initial Trauma and Timeline

• Patient fell from an 8-foot ladder, landing on back with no direct impact to head or neck
• Initial symptoms: mid and upper back pain localized to trapezius
• 16 months later: transient left-sided numbness in face and hand (5 minutes)
• 8 years later: left-sided face and arm weakness with imaging showing:
  • Right watershed infarct
  • Right distal supraclinoid ICA occlusion
  • No evidence of dissection (no flap, pseudoaneurysm, or intramural thrombus)

Evidence Against Causal Relationship

1. Timing of symptoms: The significant delay (16 months for initial neurological symptoms, 8 years for stroke) makes trauma-related vascular injury unlikely 1

2. Absence of dissection findings: CT angiogram showed no evidence of dissection such as flap, pseudoaneurysm, or intramural thrombus in the cervical ICA 1

3. Mechanism of injury: The fall involved impact to the back without direct trauma to head or neck, which is not a typical mechanism for carotid injury 1, 2

4. Location of occlusion: The distal supraclinoid ICA occlusion is not the typical location for traumatic vascular injuries, which more commonly affect the cervical portion of the ICA 3

Blunt Cerebrovascular Injury (BCVI) Considerations

Risk Factors for BCVI (not present in this case)

• High-energy transfer mechanism 1
• Displaced LeFort II/III midface fracture 1
• Complex skull fracture/basilar skull fracture 1
• Cervical spine fractures involving C1-3 or transverse foramen 1
• Direct "clothesline-type" injury to neck 1

Typical Presentation of BCVI

• Usually presents acutely or subacutely (days to weeks) after trauma 1
• Typically involves the cervical portion of the ICA rather than distal/intracranial segments 1, 3
• Often associated with visible external signs of trauma in the head/neck region 1, 4

Alternative Explanations for Current Findings

The patient's current neurological symptoms and imaging findings are more likely explained by:

1. Atherosclerotic disease: The most common cause (65%) of ICA occlusion 5
2. Cardioembolic source: Accounts for approximately 22% of ICA occlusions 5
3. Other vascular risk factors: Age, hypertension, hyperlipidemia, and other traditional stroke risk factors 5

Clinical Implications

• Focus evaluation on common causes of stroke in this age group rather than the remote trauma
• Assess for traditional vascular risk factors and cardioembolic sources
• Standard stroke workup and secondary prevention measures are appropriate
• Long-term prognosis should be considered in light of the etiology (45% mortality at 1.2 years follow-up for ICA occlusion) 5

Conclusion

Based on the timeline, mechanism of injury, and imaging findings, there is insufficient evidence to establish a causal relationship between the ladder fall 8 years ago and the current ICA occlusion with resultant stroke symptoms. The clinical picture is more consistent with other common causes of ICA occlusion such as atherosclerosis or cardioembolism.