What are the signs of a basilar skull fracture?

Signs of Basilar Skull Fracture

The classic signs of basilar skull fracture include raccoon eyes (periorbital ecchymosis), Battle's sign (retroauricular ecchymosis), CSF otorrhea, CSF rhinorrhea, hemotympanum, bleeding from ear canals, and cranial nerve deficits, particularly facial nerve (CN VII) paralysis. 1

Clinical Signs and Their Presentation

External Signs

• Raccoon eyes (periorbital ecchymosis): Bruising around the eyes
• Battle's sign (retroauricular ecchymosis): Bruising behind the ears, typically appearing 24-48 hours after injury
• Otorrhea: Clear or blood-tinged fluid draining from the ear
• Rhinorrhea: Clear fluid draining from the nose
• Hemotympanum: Blood behind the tympanic membrane
• Bleeding from ear canals: Active bleeding from the external auditory canal

Neurological Signs

• Cranial nerve deficits: Particularly facial nerve (CN VII) paralysis
• Hearing loss: Can be conductive or sensorineural depending on the location of the fracture
• Dizziness and nausea: Due to labyrinthine involvement in petrous bone fractures 2

Diagnostic Value of Clinical Signs

It's important to note that clinical signs alone have limitations in diagnosing basilar skull fractures:

• Clinical signs have low accuracy (55.9% for early detection, 43.4% for late detection)
• Low specificity (52.8% for early detection, 30.5% for late detection)
• Low positive predictive value (25.7% for early detection, 27.1% for late detection) 3

However, these signs correlate with head injury severity as indicated by Glasgow Coma Scale and Maximum Abbreviated Injury Scale-Head region scores 3.

Risk Stratification

The presence of clinical signs of basilar skull fracture places patients in a higher risk category:

• In pediatric patients, signs of basilar skull fracture are considered high-risk features that warrant immediate CT imaging 4
• In adults, clinical signs of basilar skull fracture are strong indicators for obtaining a CT scan according to multiple clinical decision rules 4

Clinical Implications

When basilar skull fracture is suspected based on clinical signs:

1. Avoid nasal instrumentation: The low accuracy of clinical signs contradicts using them to make decisions about using the nasal route for introducing catheters and tubes in initial trauma care 3

2. Obtain CT imaging: CT scan is necessary for definitive diagnosis and risk stratification, especially when any clinical signs of basilar skull fracture are present 1

3. Monitor for complications: Basilar skull fractures can lead to serious complications including:

   • CSF leakage
   • Meningitis
   • Vascular injuries
   • Cranial nerve injuries 5

4. Observe for meningitis: Rather than prophylactic antibiotics, close observation for early signs of meningitis is recommended 6, 7

Remember that patients with basilar skull fractures confirmed on CT have a higher risk of adverse outcomes than those with only clinical signs, and the presence of other intracranial injuries significantly increases morbidity and mortality 1.