Otogenic Intracranial Abscesses, Our Experience Over the Last Four Decades.

OBJECTIVE To evaluate the predisposing factors for otogenic intracranial abscesses, assess their changes over time, and analyze how they differ from those due to other causes. MATERIALS AND METHODS The medical records of all patients treated for otogenic intracranial abscesses, between 1970 and 2012 at a tertiary referral center, were retrospectively analyzed. The analysis included patient demographics, clinical characteristics, causative pathogens, treatments, outcomes, and comparisons of otogenic and non-otogenic intracranial abscesses. RESULTS Of all intracranial abscesses, 11% (n=18) were otogenic. In the 1970s, otogenic infections were a common predisposing factor for intracranial abscess; but within our study period, the incidence of otogenic intracranial abscesses decreased. Most (94%) otogenic cases were due to chronic suppurative otitis media and 78% were associated with cholesteatoma. Most patients (94%) had ear symptoms. The most common presenting symptoms were discharge from the infected ear (50%), headache (39%), neurological symptoms (28%), and fever (17%). The most common pathogens belonged to Streptococcus spp. (33%), Gram-negative enteric bacteria (22%), and Bacteroides spp. (11%). Neurosurgery was performed on all patients, 69% of which were prior to a later ear surgery. Surgery of the affected ear was performed on 14 patients (78%). A favorable recovery was typical (78%); however, one patient died. CONCLUSION Otogenic intracranial abscesses were most commonly due to a chronic ear infection with cholesteatoma. Ear symptoms and Gram-negative enteric bacteria were more common among patients with otogenic than non-otogenic intracranial abscesses.