Central Skull Base Osteomyelitis in Queensland, Australia, 2010-2020

Abstract

Background: Central skull base osteomyelitis (CSBO) is an incompletely defined, life-threatening infection of the bones of the cranial vault. We describe the clinical features and outcomes of CSBO in Queensland, Australia, over an 11-year period.

Methods: Medical record coding enquiries identified cases of CSBO across 6 tertiary hospitals in Queensland, Australia, from January 2010 to December 2020. Epidemiological, demographic, diagnostic, management, and outcome data were collected from each identified case.

Results: Twenty-two cases of CSBO were identified within the study period; the median age was 73 years with a male predominance (73%). High rates of comorbid disease were detected, with a median Charlson Comorbidity Index score of 5. Diabetes mellitus was the most frequently observed condition. Six cases had bone sampling for microbiological diagnosis while the remainder had superficial sampling of contiguous structures. The most common pathogen isolated was Pseudomonas aeruginosa followed by Staphylococcus aureus, with only 1 case of fungal infection. This series demonstrated a mortality rate of 31.8%, with 45.5% of cases left with long-term sequelae including persistent pain and cranial nerve deficits.

Conclusions: Four key observations emerged in this series: (1) advanced age and diabetes mellitus are common risk factors for CSBO, (2) limited surgical intervention occurred, (3) microbiological diagnoses relied primarily on superficial sampling, and (4) significant mortality and morbidity was observed. Prospective studies are needed to better understand the optimal approach to the diagnosis and management of CSBO and to improve clinical outcomes.

Keywords: Australia; bacterial infection; fungal infection; osteomyelitis; skull base.

Graphical Abstract

This graphical abstract is also available at Tidbit: https://tidbitapp.io/tidbits/central-skull-base-osteomyelitis-in-queensland-australia-2010-2020

Figure 1.

Anatomy of skull base osteomyelitis and its variants. Image adapted from Khan et al [1], “A comprehensive review of skull base osteomyelitis: diagnostic and therapeutic challenges among various presentations,” Asian Journal of Neurosurgery, 2018; 13:959–70. This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License (https://creativecommons.org/licenses/by-nc-sa/4.0/). Abbreviation: MRSA, methicillin-resistant Staphylococcus aureus.

Figure 2.

Medical imaging demonstrating features of central skull base osteomyelitis from selected cases. A (case 1), Axial T1 gadolinium contrast-enhanced magnetic resonance image demonstrating marked enhancement of paranasal sinuses and right skull base involving clivus, sphenoid, and right petrous apex. B (case 9), Axial computed tomographic image demonstrating decortication of the clivus bilaterally along the lateral and anterior margins. C (case 4), Axial fused gallium-67 image showing increased gallium-67 tracer uptake extending posteriorly to the region of the clivus. D (case 3), Axial fused fluorodeoxyglucose (FDG) positron emission tomography image showing intense FDG uptake eroding the clivus. On the right, FDG uptake extends laterally, eroding the petrous part of the temporal bone and involving the foramens lacerum and jugular foramen.