Can imaging suggest the aetiology in skull base osteomyelitis? A systematic literature review

Skull base infections, their complications, and management

OBJECTIVE

Our review aims to summarize the current literature on skull base infections (SBIs) and retrospectively analyze any such cases encountered at our institution.

DESIGN

A literature search was conducted using online databases PubMed, MEDLINE, and ResearchGate with the terms "skull base osteomyelitis," "temporal bone osteomyelitis," "skull base infections," "necrotizing otitis media," and "SBO". References from the resulting manuscripts were reviewed for relevant articles. A search of our electronic health records using the same key terms was also performed to identify patients with a tissue biopsy-confirmed diagnosis of skull base infections. Patients with an indeterminate diagnosis or inaccessible/poor imaging were excluded.

SETTING

A level one trauma and major tertiary academic medical center.

PARTICIPANTS

All patients treated at the University of California Davis Health System with a confirmed diagnosis of skull base infections from January 2005 to November 2020.

MAIN OUTCOME MEASURES

Imaging results, symptoms, treatment, morbidity, and mortality.

RESULTS

Our literature search yielded 59 articles ranging from 1982 to 2021. A retrospective search of our electronic health records identified two cases of skull base infections.

CONCLUSION

Skull base infections have no pathognomonic findings. A multimodal approach with computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine is necessary to characterize the disease process in addition to a biopsy for definitive diagnosis. Other diagnoses can mimic SBI on imaging, such as nasopharyngeal carcinoma and inflammatory pseudotumor. Culture-guided antimicrobial treatment and surgery are mainstay therapies. Other adjuvant strategies currently lack the robust evidence necessary to characterize their risks and benefits.

Trends and Outcomes of Fungal Temporal Bone Osteomyelitis: A Scoping Review

INTRODUCTION

Temporal bone osteomyelitis is an invasive infection most often caused by bacteria and associated with high mortality. Fungal etiologies are rare and little is known of the predictors of disease severity and outcomes in fungal temporal bone osteomyelitis.

MATERIALS AND METHODS

A scoping review was performed to determine what is known from the literature on how clinical, diagnostic, and treatment characteristics relate to patient outcomes in fungal temporal bone osteomyelitis. Using PRISMA guidelines, three databases were searched to identify all published cases of fungal temporal bone osteomyelitis. Data were extracted from each study, including clinical, diagnostic, and treatment characteristics, and outcomes.

RESULTS

Sixty-eight studies comprising 74 individual cases of fungal temporal bone osteomyelitis were included. All studies were case reports. There were high rates of diabetes, facial nerve palsy, infectious complications, and need for surgical intervention, as well as a significant delay in the evaluation and diagnosis of fungal temporal bone osteomyelitis. Disease recovery was greater in patients presenting with otorrhea, comorbid diabetes, and in those without facial nerve palsy.

DISCUSSION

Many of the defining characteristics of fungal temporal bone osteomyelitis remain unknown, and future reports should focus on determining factors that improve timely diagnosis and treatment of fungal TBO in addition to identifying prognostic indicators for outcomes and survival.

Atypical presentations of fungal osteomyelitis during post COVID-19 outbreak – Case series

Introduction

Mucormycosis and Aspergillosis are opportunistic fungal infections causing significant morbidity and mortality. Post the outbreak of COVID-19, these fungal osteomyelitis have seen a global rise with few atypical presentations noted.

Case report

Current case series reports three such atypical presentations of fungal osteomyelitis including mandibular fungal osteomyelitis in two patients, fungal osteomyelitis mimicking space infection in a middle aged male, and suspected mixed fungal osteomyelitis involving maxillary sinus. Aggressive surgical debridement was indicated along with institution of antifungal therapy (Liposomal Amphotericin B, and Posaconazole). The fungal osteomyelitis was successfully treated with surgical and medical management with no recurrence.

Discussion

The injudicious use of corticosteroids in COVID-19 patients along with their immunocompromised status increases their susceptibility to opportunistic fungal osteomyelitis. Prompt and aggressive surgical intervention along with antifungal therapy is important after diagnosing fungal osteomyelitis, as a delay could increase the mortality rate considerably.

Skull base osteomyelitis imaging

PURPOSE OF REVIEW

Skull base osteomyelitis (SBO) is a challenging entity to diagnose and treat. The goal of this review is to summarize the imaging findings of SBO and present these in the context of recent studies on imaging of SBO.

RECENT FINDINGS

This review discusses the clinical presentation, pathophysiology and imaging appearances of SBO. The review further emphasizes the results of latest studies on imaging of SBO, and the role of different modalities in diagnosis and evaluation of disease course and treatment response. Brief discussion on differential diagnoses from an imaging standpoint is also included.

SUMMARY

Various imaging modalities play different and complimentary roles in diagnosis and management of SBO, which are discussed in this review.

Revisiting rhino-orbito-cerebral acute invasive fungal sinusitis in the era of COVID-19: pictorial review

COVID-19 patients have been found to have an increased incidence of superadded fungal infections because of multiple factors such as impaired cell-mediated immunity, immunosuppressive therapy, and coexistent diabetes mellitus. Recently, there has been a significant rise in the COVID-19-associated mucormycosis and aspergillosis cases involving the sinonasal cavity and the lungs. Rhino-orbito-cerebral acute invasive fungal rhinosinusitis (AIFR) is a potentially life-threatening, invasive fungal infection. Early diagnosis followed by prompt medical management and surgical intervention is crucial for patient survival. The role of cross-sectional imaging (CT/MRI) is not only to suggest a diagnosis of invasive fungal sinusitis but also to delineate the complete extent of disease. Mapping the extent of orbital and intracranial disease has prognostic as well as management implications, as involvement of these sites marks a worse prognosis. A stepwise approach to evaluation of imaging of AIFR along with a pictorial depiction of the key imaging findings is presented.