Temporal Bone Fractures

Temporal Bone Fractures: Intro & Anatomy - Skull Base Shaker

• Fractures of the temporal bone, a component of the skull base; typically result from high-impact head trauma (e.g., road traffic accidents, falls, assaults).
• Anatomy: Consists of four main parts: squamous, mastoid, petrous, and tympanic.
  • Houses vital neurovascular structures: Facial nerve (CN VII), vestibulocochlear nerve (CN VIII), internal carotid artery, jugular bulb, sigmoid sinus, ossicles, and labyrinth.
  • Petrous portion: Densest bone, protects inner ear structures.

⭐ The course of the facial nerve through the temporal bone makes it particularly susceptible to injury in these fractures, potentially leading to facial paralysis.

Temporal Bone Fractures: Classification - Fracture Fault Lines

• Traditional (vs. Petrous Ridge Axis):

  • Longitudinal (~70-90%):
    • Parallel to ridge.
    • Cause: Lateral blow.
    • Features: CHL, CSF otorrhea; Facial N. injury (10-20%).
  • Transverse (~10-30%):
    • Perpendicular to ridge.
    • Cause: Frontal/occipital blow.
    • Features: SNHL, vertigo; Facial N. injury (~50%); Hemotympanum.
  • Mixed: Elements of both.

• Modern (Otic Capsule Involvement - clinically vital):

  • Otic Capsule Sparing (OCS):
    • Labyrinth NOT involved.
    • Typically longitudinal.
  • Otic Capsule Violating (OCV):
    • Labyrinth involved.
    • Typically transverse; ↑Risk SNHL, facial palsy.

⭐ Transverse fractures: higher incidence of facial nerve injury (~50%) & profound SNHL.

Temporal Bone Fractures: Clinical Features & Diagnosis - Signs & Scans Spotlight

• Clinical Presentation:
  • Otorrhagia, hemotympanum
  • CSF otorrhea/rhinorrhea (⚠️ dural tear sign)
  • Battle’s sign (postauricular ecchymosis)
  • Raccoon eyes (periorbital ecchymosis)
  • Hearing Loss: Conductive, Sensorineural (SNHL), or mixed
  • Facial Nerve (CN VII) Palsy: Immediate (poorer prognosis) vs. Delayed (better prognosis)
  • Vertigo, nystagmus
• Diagnostic Gold Standard:
  • HRCT Temporal Bone: Axial & coronal views. Details fracture lines, ossicular chain, otic capsule involvement.
• Ancillary Tests:
  • Audiometry: Assess type & degree of hearing loss.
  • Facial Nerve electroneurography (ENoG) / electromyography (EMG) if palsy present & severe.

⭐ Transverse fractures, though less common (approx. 20%), more frequently involve the otic capsule, leading to profound SNHL and immediate facial palsy compared to longitudinal fractures.

Temporal Bone Fractures: Management & Complications - Mend & Monitor Mayhem

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High‑Yield Points - ⚡ Biggest Takeaways

• Longitudinal fractures (most common): Temporoparietal impact; cause CHL, CSF otorrhea, TM perforation.
• Transverse fractures: Fronto-occipital impact; higher risk of SNHL, vertigo, severe facial nerve palsy (up to 50%).
• Facial nerve injury: More frequent and severe in transverse fractures; can be immediate or delayed.
• Otic capsule violation (transverse) often causes profound SNHL and vertigo.
• Battle's sign and CSF otorrhea are key clinical indicators.
• HRCT temporal bone is the diagnostic imaging standard.