Can mild trauma without facial injury or skull base fracture lead to traumatic intracranial dissection?

Traumatic Intracranial Dissection Following Mild Trauma Without Facial Injury or Skull Base Fracture

Mild trauma without facial injury or skull base fracture can lead to traumatic intracranial dissection, though it is relatively uncommon.

Mechanism and Risk Assessment

Intracranial arterial dissections typically occur through the following mechanisms:

• Most intracranial arterial dissections occur spontaneously without a history of significant trauma 1
• Patients with intracranial dissections tend to be relatively young (average age of 39 years) 1
• Hypertension is the most commonly identified vascular risk factor 1
• The absence of facial injury or skull base fracture does not exclude the possibility of intracranial dissection 2

Clinical Presentation

Intracranial dissection may present with:

• Headache (most common presentation, especially with extracranial dissections) 3
• Focal neurological deficits
• Ischemic symptoms (TIA or stroke) 1
• Subarachnoid hemorrhage (SAH), more common with posterior circulation dissections 1
• Delayed focal cerebral ischemic symptoms after a lucid interval following head trauma 4

Diagnostic Considerations

When evaluating a patient with mild head trauma:

• The absence of skull fracture or facial injury does not reliably exclude intracranial pathology 2
• Masters (1980) found that 32% of patients had positive CT findings without fractures, while 27% had fractures with negative CT findings 2
• Cooper and Ho demonstrated that 63% of patients with intracranial lesions on CT had normal plain films 2
• Clinical risk factors that warrant neuroimaging include:
  • GCS score of 14
  • Loss of consciousness
  • Vomiting
  • Headache
  • Signs of basilar skull fracture
  • Neurologic deficit
  • Coagulopathy
  • Age ≥65 years 2

Imaging Recommendations

For suspected intracranial dissection:

• Non-contrast head CT is the initial imaging modality of choice in acute trauma 2
• CT angiography (CTA) or MR angiography (MRA) may be necessary to confirm a dissection 3
• Multiplanar and 3D-reconstructed CT images increase sensitivity for small hemorrhages 2
• MRI with susceptibility-weighted imaging and diffusion-weighted imaging offers increased sensitivity for small bleeds and non-hemorrhagic injuries 2

Prognosis and Treatment

The prognosis of intracranial dissection varies based on presentation:

• Patients presenting with ischemia tend to have more favorable outcomes (83.3% with favorable outcome at 90 days) compared to those with SAH (46.2%) 1
• Mortality rate is approximately 16.7% in the ischemia group and 7.7% in the SAH group 1
• Treatment options include:
  • Medical therapy (antiplatelet or anticoagulation) for ischemic presentations
  • Endovascular or surgical intervention for SAH presentations 1

Clinical Pitfalls and Caveats

• Relying solely on the absence of facial injury or skull fracture to exclude intracranial pathology is dangerous
• A lucid interval followed by neurological deterioration should raise suspicion for vascular injury 4
• Symptoms of intracranial dissection may develop months or years after the initial trauma 4
• Blunt cerebrovascular injuries (BCVI) occur in approximately 1.2% of trauma patients, with a mortality rate of 13% 5
• Stroke occurs in approximately 12% of patients with BCVI, with a 50% stroke-related mortality 5

In conclusion, while less common without facial injury or skull base fracture, intracranial dissection can still occur following mild trauma and should be considered in the differential diagnosis, especially in patients with persistent or progressive neurological symptoms.