Otogenic intracranial complications

Otogenic intracranial complications

Intracranial complications can occur in both acute and chronic purulent otitis media (inflammation of the middle ear). Usually, the cause of complications is purulent inflammation of the middle ear, but there are observations, when the culprit non-suppurative otitis media without perforation of the eardrum. In acute inflammatory process, intracranial complications most often occur only after mastoiditis.

In chronic suppurative otitis media, intracranial complications occur much more frequently than in acute middle ear inflammation. They are observed mainly in chronic epitimpanites and meso-epimimpanites, especially complicated cholesteatoma. Nevertheless, complications are also occasionally described in chronic mesotympanites.

Magnetic resonance imaging (MRI) of the brain performed for suspected intracranial complications of middle ear infection (otitis media).

The spread of infection from the middle ear cavity to the brain and its membranes and venous sinuses of dura mater occurs:

• by contact (usually)
• by vascular pathways (mostly venous, but sometimes by arterial and lymphatic pathways)

When the contact pathway of infection (mostly chronic suppurative otitis media) due to the gradual destruction of the bone wall of the tympanum and the mastoid (mainly the roof and the inner wall of the mastoid in sigmoid sulcus) and the labyrinth when the inflammatory focus begins to directly contact the brain membranes (middle and posterior cranial fossae), the inflammatory process may be limited for some time the outer surface of dura mater. In other cases, it spreads deeper and goes on the arachnoid and pia mater and even on the brain tissue.

After the penetration of infection into the sigmoid sinus usually develops sepsis.

The causative agents of intracranial otogenic complications are most often Streptococci, then Staphylococci, Pneumococci, less often Escherichia coli, Proteus, Anaerobes, etc. Intracranial otogenic complications include:

• Epidural abscess
• Subdural abscess
• Suppurative thrombophlebitis
• Bacterial meningitis
• Brain abscess (lobar, cerebellar)
• Arachnoiditis (hydromeningitis)