Brain abscesses of ear, nose, and throat origin: Comparison between otogenic and sinogenic etiologies

This retrospective study analyzed 29 cerebral abscesses of ear, nest, and t hroat (ENT) origin. The mean follow-up of patients was 37 months. ENT etiol ogies included 45% otitis media (n = 13), 48% sinusitis (n = 14), and 7% et hmoidal sinus tumors (n = 2). Thirty-eight percent (n = 5) of otogenic absc esses occurred within 15 days after a mastoidectomy. Sinogenic abscesses we re never due to surgery but were associated in 31% of cases (n = 5) with an terior skull base defects. The main locations of otogenic abscesses were th e temporal lobe (54%; n = 7) and the cerebellum (23%; n = 3), whereas sinog enic abscesses were located in the frontal lobe in 75% of cases (n = 12). B ecause of this location, sinogenic abscesses were less symptomatic than oto genic ones and had greater size and encapsulation at the time of diagnosis. Thus, they required longer antibiotic treatment (p = 0.05) and more numero us surgical drainages (p = 0.02). Bacteriologic abscesses samples were posi tive in 90% of cases. Bacteria found in brain abscesses were different from the ones found in ENT samples in 62% of cases. Thus, the results of ENT ba cteriologic, samples were not helpful for choosing adequate antibiotic agen ts in case of negative brain abscess samples. Although mortality was not si gnificantly higher in otogenic abscesses (31%; n = 4) than in sinogenic one s (6%; n = 1,p = 0.08), otogenic abscesses appeared more threatening. Indee d, they represented 80% (n = 4) of lethal cases acid encompassed more clini cal or radiological prognosis pejorative factors than sinogenic ones (p = 0 .006). In conclusion, higher danger of otogenic abscesses mainly resulted b oth from their temporal or cerebellous locations and from the bacteria that were more frequently resistant to antibiotics.