Introduction
Otitis media is a disease of the middle ear marked by the inflammation
of the mucosal lining. When it lasts more than two weeks, it develops
into chronic otitis media (COM). Chronic otitis media is marked by the
presence of a perforated tympanic membrane, and recurrent purulent
discharge.1-3 Otitis media is one of the most common
infections of childhood: by the age of 3 years more than 80% of
children will have had at least 1 episode of otitis
media.4 COM can lead to both extracranial, and
intracranial complications. Sixty to seventy percent of these
complications occur in children and young adults: during the first two
decades of life.5-7 Intracranial complication is an
infrequent complication with reported rates ranging from 0.3% in
developed countries to 3% in developing countries.5,6Its pathogenesis, that is its spread from the ear canal, is through
direct invasion of the bone, thrombophlebitis, haematogenous spread, and
dissemination through congenital or traumatic bone
defects.6,8,9
The most common intracranial complications are brain abscess,
meningitis, and lateral sinus thrombosis.3,6,10Subdural empyema, the purulent collection between the dura and arachnoid
matter, is a rare but serious intracranial complications of
COM.8,11 It is exceedingly rare that a study by Dongol
et al. found only one case of subdural empyema (3.7%) out of 27
patients of chronic otitis media with intracranial
complications.7 Extension from otogenic infections is
the most common cause of subdural empyema in older
children.8,9,12 The most common pathogens areStreptococcus pneumoniae (most common), Haemophilus
influenzae, Moraxella catarrhalis, Staphylococcus aureus and
Gram-negative rods (Pseudomonas aeruginosa, Escherichia coli,
Proteus, Klebsiella ) as well as anaerobic Bacteroides
species.5,13,14 Patients with Subdural empyema present
with fever, headache, vomiting, and altered mental
status.11,14-16 MRI and CT scan are important in the
diagnosis of subdural empyema; MRI being the most
sensitive.6,8,12 Culture and sensitivity from the pus
is necessary although the yield is low.14,5-8 The
principles of treatment, common to all intracranial complications,
include early definitive diagnosis, appropriate systemic antibiotic
therapy, neurosurgical intervention, and treatment of the ear lesion
after the patient stabilizes.