Otology: Intracranial Complications – Epidural Abscess
High-Yield Revision for NEET PG
An epidural abscess (extradural abscess) is an intracranial collection of pus located between the inner table of the skull and the dura mater. In ENT, this is a significant complication of chronic suppurative otitis media (CSOM).
1. Pathophysiology & Clinical Features
- Route: Spread occurs via bone erosion (osteitis) of the tegmen tympani or tegmen antri.
- Symptoms: Often clinically “silent” (asymptomatic) because the abscess is contained by the dura. It is frequently discovered incidentally during mastoid surgery for CSOM.
- Signs: Persistent throbbing headache, deep-seated pain, and signs of systemic toxicity (fever, malaise).
2. Diagnostic & Management Strategy
| Investigation/Action | Significance |
|---|---|
| CT Scan (Contrast) | Gold standard; shows a collection displacing the dura. |
| MRI | Superior for assessing dural integrity and associated brain parenchymal involvement. |
| Surgical Approach | Mastoidectomy with drainage of the abscess and removal of necrotic bone. |
3. NEET PG High-Yield Pearls
- Most Common Site: Middle cranial fossa (above the tegmen).
- Key Differentiation: Epidural abscess is often circumscribed and less likely to cause frank meningeal signs compared to subdural empyema or meningitis.
- Management Note: If an epidural abscess is identified during surgery, it must be drained, and the surrounding bone should be saucerized until bleeding, healthy dura is visualized.