Skull base osteomyelitis: factors implicating clinical outcome

Understanding the Impact of Skull Base Osteomyelitis: A Retrospective Analysis of 14 Cases

Purpose Skull base osteomyelitis (SBO) or malignant otitis externa (MOE) is an invasive bacterial infection (a rarely fungal as well as potentially aggressive infection that involves the external auditory canal up to the temporal bone and skull base. This study provides insight into the various clinical presentations of skull base osteomyelitis, the effectiveness of different treatment approaches, and the overall prognosis of SBO based on our case series. Materials and methods This observational study comprises 14 SBO cases, including their diagnosis, follow-up, and treatment.  Results Otalgia and purulent otorrhea were observed in all our cases as common symptoms. All patients were diabetic. Three cases (21%) presented with facial palsy and two cases (14%) reported a rare progression of SBO resulting in septic arthritis of the temporomandibular joint. In our study, 43% of the cases diagnosed with SBO had resistance to ciprofloxacin. All our patients had daily cleaning of the auditory canal and the application of antimicrobial ear drops along with long-term systemic antibiotic therapy followed by three weeks of oral antibiotic therapy. All our cases were reviewed after three weeks. Resolution of the disease was achieved. Conclusion Early diagnosis, good control of blood glucose levels, prolonged medical management, and local debridement are likely to result in a better prognosis for patients.

Microbial spectrum, management challenges, and outcome in patients with otogenic skull base osteomyelitis

Objectives

The study aimed to explore the spectrum and trend of causative microbial agents and to identify management challenges and the risk factors for poor outcomes in patients with confirmed otogenic skull base osteomyelitis.

Methods

A retrospective observational study was conducted at a tertiary-care academic center from 1999 through 2019 and included 28 adult patients with confirmed otogenic skull base osteomyelitis. Relevant data was extracted from electronic and hard patient medical files. The microbial spectrum of involved microbes was identified and correlated to management options. Deterioration risk factors were investigated using suitable statistical analysis tests.

Results

Twenty-eight patients with confirmed skull base osteomyelitis were included; most were males (78.6%) and Saudis (78.6%). All patients were ≥50 years of age (mean ± SD is 69.0±10.2.4). Of 41 identified microbial isolates, 56% were bacterial, 44% were fungal. 32.1% of patients had polymicrobial infections, most patients (92.8%) had received ≥2 systemic antibiotics, 57.1% received systemic antibiotic combinations, and 32.1% underwent surgical interventions. The mean antibiotic and antifungal therapy duration was 58.3 and 45.8 days, respectively. The identified risk factors of deterioration were advanced age and concomitant cardiac failure, with P-values of .006 and .034, respectively.

Conclusions

The study findings highlight the microbiological spectrum and trend of otogenic skull base osteomyelitis-causative microbes over two decades, present the management challenges, identify deterioration risk factors, and suggest tissue biopsy as the golden standard for accurately identifying causative microbes.

18F-FDG PET imaging for treatment response assessment and management guidance in patients with skull base osteomyelitis

OBJECTIVE

The objective of this study is to evaluate the role of hybrid 18F-FDG PET for treatment response assessment and management guidance in patients with skull base osteomyelitis.

MATERIALS AND METHODS

Retrospectively, 33 patients, with at least a baseline and follow-up PET (computed tomography/MRI) scan, were included. Parameters like standardized uptake value (SUV) max, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) (initial, follow-up, percentage change) were analysed and outcomes based on 18F-FDG PET reports were classified into resolution (a), partial response (b), progression (c) and stable disease (d). The clinical course and response on anatomical imaging were also compared with 18F-FDG PET.

RESULTS

There was mild correlation between initial SUV with ESR (0.338) and CRP (0.384). Moderate correlation was seen between follow-up SUV and CRP (0.619), percentage change in SUV max (PC SUV) with percentage change in ESR (0.456) and CRP (0.668). Mean PC SUV was 70% (a), 35% (b), -40% (c) and -18% (d), respectively. 48% (16/33) (resolution, progression, stable disease) patients had clear management change with 18F-FDG PET with either escalation or stopping of antibiotics/antifungals. Management decision in partial response group (52%, 17/33) was taken clinically. On retrospective PC SUV analysis, treatment continuation group (8 patients) showed 20% decrease, whereas the group that was only monitored further (9 patients) had 48% reduction in SUV.

CONCLUSION

18F-FDG PET showed a moderate association with clinical markers used in follow-up of patients with skull base osteomyelitis and is a reliable investigation for assessment of disease status. This can be used as a guide along with clinical evaluation for de-escalation of treatment.

Skull Base Osteomyelitis: A 5-Year Review and Prognostic Outcome in a Single Tertiary Institution

Objective

The primary objective of this study is to review the clinical parameters associated with skull base osteomyelitis (SBO), with a secondary aim of studying their association with patient outcomes 1 and 6 months after treatment initiation.

Study Design

This is a single-center restrospective observational study.

Setting

The study was conducted from January 2018 to December 2022 at the University Malaya Medical Center in Kuala Lumpur.

Methods

Patients aged over 15 years with a diagnosis of SBO were included in the study. Clinical parameters, investigations, and follow-up records were recorded. The disease outcomes were analyzed at 1 and 6 months after treatment initiation using multivariable analyses.

Results

The study identified 31 patients with SBO, the majority of whom were elderly males with comorbidities such as diabetes and hypertension. Otalgia and otorrhea were the most common symptoms, and computed tomography scans were used for diagnosis. Pseudomonas aeruginosa was the most commonly identified pathogen, and intravenous broad-spectrum antimicrobials were used to treat all patients. Surgical intervention was required for 25% of patients, and underlying ischemic heart disease, anemia, and single nerve palsy were significantly associated with an unfavorable prognosis. Patients with higher body mass index and elevated C-reactive protein showed poorer outcomes after 1 and 6 months of treatment, respectively.

Conclusion

Early recognition, prompt treatment, better control of comorbidities, nutrition, and monitoring can improve SBO outcomes and reduce complications. Therefore, as the prevalence of SBO increases, diagnostic criteria or management guidelines should be established to guide the best clinical practice.

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.

Management and Outcomes of Necrotizing Otitis Externa: A Retrospective Cohort Study in a Tertiary Referral Center

Objectives

Necrotizing otitis externa (NOE) is a rare infection of the ear that causes osteomyelitis. We aimed to evaluate treatment outcomes and the role of imaging in diagnosing and monitoring disease resolution in a single-center study of patients with NOE.

Methods

In this retrospective cohort study, patients with NOE who were diagnosed and treated in a tertiary otology center in Utrecht, The Netherlands, between January 1, 2013 and August 1, 2022, were included. Data were retrieved from the medical records on demographics, symptoms, physical and diagnostic findings, type and duration of treatment, and course of disease.

Results

A total of 24 cases were included. Patients were often elderly (mean age = 75 years) and diabetic (88%). Pseudomonas aeruginosa was the most commonly found microorganism (63%). Twenty-two cases (92%) received intravenous antibiotic treatment, and 7 cases (29%) received additional systemic antifungal treatment. The mean duration of systemic treatment was 29 weeks. In 20 out of 22 cases (91%), imaging was used to determine the end point of treatment. None of the cases with a total resolution of disease activity (n = 5) on 18F-fluorodeoxyglucose-positron emission tomography-computed tomography imaging at the time of cessation of therapy showed clinical relapse, compared with 1 out of 4 cases on gallium single-photon emission computerized tomography.

Conclusion

Based on the experience from our center, we demonstrated that patients with NOE can successfully be treated with prolonged systemic treatment. Molecular imaging is reasonably successful for disease evaluation and decision-making on the eradication of disease.

A Novel Case of Providencia rettgeri Osteomyelitis Presenting in the Frontal Bone

Osteomyelitis of the skull is a particularly life-threatening condition. Infections are usually at the base of the skull and typically occur following dissemination from another site, such as the external auditory canal. Typical organisms include Pseudomonas and Staphylococcus species. This paper demonstrates an unusual case of osteomyelitis of the frontoparietal bone, as well as the first published case of Providencia rettgeri causing cranial osteomyelitis in humans.

Skull base osteomyelitis with extensive bony erosion complicated by venous sinus thrombosis

Skull base osteomyelitis (SBO) mimics the presentation of various conditions, including solid tumors. Computed tomography-guided core biopsy for culture informs antibiotic selection, and with intravenous corticosteroids, may minimize chronic neurologic dysfunction. Although SBO predominantly affects individuals who are diabetic or immunocompromised, it is important to be able to recognize SBO presenting in an otherwise healthy individual.

Dynamic Contrast-Enhanced MRI Parameters and Normalized ADC Values Could Aid Differentiation of Skull Base Osteomyelitis from Nasopharyngeal Cancer

BACKGROUND AND PURPOSE

The skull base osteomyelitis sometimes can be difficult to distinguish from nasopharyngeal cancer. This study aimed to investigate the differences between skull base osteomyelitis and nasopharyngeal cancer using dynamic contrast-enhanced MR imaging and normalized ADC values.

MATERIALS AND METHODS

This study included 8 and 12 patients with skull base osteomyelitis and nasopharyngeal cancer, respectively, who underwent dynamic contrast-enhanced MR imaging and DWI before primary treatment. Quantitative dynamic contrast-enhanced MR imaging parameters and ADC values of the ROIs were analyzed. Normalized ADC parameters were calculated by dividing the ROIs of the lesion by that of the spinal cord.

RESULTS

The rate transfer constant between extravascular extracellular space and blood plasma per minute (Kep) was significantly lower in patients with skull base osteomyelitis than in those with nasopharyngeal cancer (median, 0.43 versus 0.57; P = .04). The optimal cutoff value of Kep was 0.48 (area under the curve, 0.78; 95% CI, 0.55-1). The normalized mean ADC was significantly higher in patients with skull base osteomyelitis than in those with nasopharyngeal cancer (median, 1.90 versus 0.87; P < .001). The cutoff value of normalized mean ADC was 1.55 (area under the curve, 0.96; 95% CI, 0.87-1). The area under the curve of the combination of dynamic contrast-enhanced MR imaging parameters (Kep and extravascular extracellular space volume per unit tissue volume) was 0.89 (95% CI, 0.73-1), and the area under the curve of the combination of dynamic contrast-enhanced MR imaging parameters and normalized mean ADC value was 0.98 (95% CI, 0.93-1).

CONCLUSIONS

Quantitative dynamic contrast-enhanced MR imaging parameters and normalized ADC values may be useful in differentiating skull base osteomyelitis and nasopharyngeal cancer. The combination of dynamic contrast-enhanced MR imaging parameters and normalized ADC values outperformed each measure in isolation.

Unusual case of skull base adenoid cystic carcinoma presenting as skull base osteomyelitis: case report

Background

Adenoid cystic carcinoma is a rare malignancy. Tumours of palatal region with minor salivary gland origin do not generally present at an early stage as the tumour is submucosal with symptoms prevalent only when there is evidence of perineural spread of the tumour. We report a case of adenoid cystic carcinoma of the palate with rare presentation of left ear discharge and diplopia on left lateral gaze. We discuss the case with emphasis on imaging evaluation mimicking a case of infective etiology with adjacent skull base osteomyelitis on initial presentation. However, on follow-up and further evaluation the patient was diagnosed as adenoid cystic carcinoma of hard palate on left side.

Case presentation

A 25-year-old male patient has presented to Jagadguru Sri Shivarathreeswara Hospital in August 2019 with complaints of left ear discharge and diplopia on left lateral gaze since 1 week. The clinical and imaging findings was suggestive of infective etiology and the patient was treated for the same with IV antibiotics. Repeat magnetic resonance imaging was then done which revealed definitive reduction in the severity of inflammation suggestive of response to therapy. Patient was then discharged and was followed up. Three months later, the patient came with complaints of mass in left nasal cavity. Patient was then referred for contrast enhanced computed tomography neck strongly suggestive of neoplastic etiology. The patient was then operated and histopathological examination of the biopsy revealed adenoid cystic carcinoma.

Conclusions

Tumours of palatal region with minor salivary gland origin do not generally present at an early stage as the tumour is submucosal with symptoms prevalent only when there is evidence of perineural spread of the tumour. In our case patient presented with lateral rectus palsy, involvement of meckel’s cave, trigeminal nerve involvement and cavernous sinus involvement which are strong indicators of the perineural and locoregional spread of the tumour. Hence, it is important for the radiologist and clinician to strongly suspect and evaluate for a primary lesion of the head and neck when such a radiological presentation has been demonstrated.

Necrotizing external otitis: analysis of relapse risk factors in 66 patients managed during a 12 year period

BACKGROUND

Necrotizing external otitis (NEO) is a severe infection of the skull base that occurs generally in the elderly and/or in diabetic recipients. There are few data in the literature about the therapeutic management of this complex bone infection.

OBJECTIVES

To analyse relapses after NEO treatment completion, and to describe the clinical features of NEO.

METHODS

We performed a retrospective cohort study in the Lyon regional reference centre for the management of complex bone and joint infections. Consecutive cases of NEO from 1 January 2006 to 31 December 2018 were included. The primary outcome was the relapse of NEO. Variables were analysed using Cox regression survival analysis with adjusted hazard ratio (aHR) and Kaplan-Meier curve.

RESULTS

Sixty-six patients were included. Median age was 75 (IQR 69-81) years and 46 (70%) patients were diabetic. Eleven patients (17%) had temporomandibular arthritis, 10 (15%) cranial nerve paralysis, 2 (3%) cerebral thrombophlebitis, and 2 (3%) contiguous abscess. Microbiological documentation was obtained in 56 patients and revealed Pseudomonas aeruginosa in 44/56 patients (79%). Nine (14%) cases had no microbiological documentation. Antibiotic therapy was dual for 63 (95%) patients. During a median follow-up of 27 (IQR 12-40) months, 16 out of 63 (25%) patients experienced a relapse. Fungal infection was significantly associated with relapse [aHR 4.1 (95% CI 1.1-15); P = 0.03].

CONCLUSIONS

NEO is a severe bone infection, mainly (but not exclusively) caused by P. aeruginosa, which occurs in elderly and diabetic recipients. Fungal infections at baseline significantly impact the outcome.

Optimal Diagnostic Criteria and a Staging System for Otogenic Skull Base Osteomyelitis

Objective  Diagnostic criteria for otogenic skull base osteomyelitis (SBO) have been conflicting among researchers. We aimed to propose clinically useful diagnostic criteria and a staging system for otogenic SBO that is associated with infection control and mortality. Design  The present study is designed as a retrospective one. Setting  This study was conducted at the University Hospital. Participants  Thirteen patients with otogenic SBO who met the novel rigorous diagnostic criteria consisted of symptomatic and radiological signs on high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI). Simple refractory external otitis was not included. A staging system according to disease extent revealed by HRCT and MRI is proposed: lesions limited to the temporal bone (stage 1), extending to less than half (stage 2), exceeding the midline (stage 3), and extending to the whole of the clivus (stage 4). All patients received long-term antibiotic therapy. Patients were divided into infection-uncontrolled or -controlled groups based on symptoms, otoscopic findings, and C-reactive protein level at the last follow-up. The mean follow-up period was 27.7 months. Main Outcome Measures  Possible prognostic factors, such as immunocompromised status and symptoms, including cranial nerve palsy, pretreatment laboratory data, and treatments, were compared between the infection-uncontrolled and -controlled groups. Disease stages were correlated with infection control and mortality. Results  The infection-uncontrolled rate and mortality rate were 38.5 and 23.1%, respectively. There were no significant differences in possible prognostic factors between the infection-uncontrolled and -controlled groups. HRCT-based stages significantly correlated with infection control and mortality. Conclusion  We proposed here the clinically useful diagnostic criteria and staging systems that can predict infection control and prognosis of otogenic SBO.

Skull base osteomyelitis in patients with head and neck cancer: Diagnosis, management, and outcomes in a case series of 23 patients

BACKGROUND

Skull base osteomyelitis (SBO) is an infection of the central cranial bones, most commonly resulting from contiguous spread of infection from adjacent head and neck structures. SBO is a well-recognized complication of treatment of head and neck cancer (HNC) that results in significant morbidity.

METHODS

We conducted a retrospective chart review of HNC patients diagnosed with SBO.

RESULTS

SBO was commonly diagnosed with nasal endoscopy showing mucosal breakdown between the naso/oropharynx and skull base and with characteristic changes on CT/MRI. Culture data were often polymicrobial, inclusive of naso/oropharyngeal flora, but half of the patients additionally had antibiotic-resistant or atypical pathogens. The mean duration of antimicrobial therapy was 117 +/- 94 days. Recurrent SBO was found in half of the patients, associated with Pseudomonas aeruginosa and with persistent defects in the mucosa abutting the skull base.

CONCLUSIONS

Diagnosis and management of SBO in HNC patients are challenging. Recommendations to aid in clinical care are proposed.

LEVEL OF EVIDENCE

4, case series.

Tubercular skull base osteomyelitis - A case report

Skull base osteomyelitis (SBO) is a complex and fatal clinical entity caused by infections in the structures surrounding the skull base. It is mainly seen in immune compromised individuals. We report one such rare case of an atypical skull base osteomyelitis in a young, immune-competent female child of 12 years of age, who presented in the ER with misleading symptoms of stroke and was diagnosed incidentally to have SBO on imaging. Adding to the uniqueness of the case is the causative organism, which was identified as Mycobacterium Tuberculosis, an unusual cause of SBO.

Skull Base Osteomyelitis: A Single-Center Experience

Background

Skull base osteomyelitis (SBO) is an uncommon entity and carries a high mortality rate. It can be be odontogenic, sinogenic, or otogenic in origin, in addition to being a complication of skull surgery/trauma. Pseudomonas is one of the most commonly identified pathogen. The goal of the study is to describe the clinical spectrum, microbiologic characteristics, treatment, and its response among different patients with SBO. In addition, we compared the outcomes of bacterial and fungal osteomyelitis.

Methodology

This is a single-center retrospective analysis of patients with SBO who presented to Shaukat Khanum Memorial Cancer Hospital & Research Centre Lahore, Pakistan between January 1998 and September 2019. A total of 15 patients with SBO were identified.

Results

SBO was common in males (79.9%) with a high body mass index. Diabetes mellitus was the most common co-morbid condition (46.62%). Bacterial etiology was seen in 46.62% and fungal isolate was detected in 6.66% of the patients; 26.64% were culture-negative and the remaining had a mixed culture. The mean duration of treatment was 17.58 ± 10.85 weeks. Overall, five (33.3%) patients were cured and did not have a recurrence of symptoms at six months, while three (19.98%) had a recurrence of symptoms at six months from the end of the treatment; six (39.96%) patients were lost to follow-up.

Conclusions

Patients with SBO can present with various conditions, and early identification of the condition and a positive culture growth can guide optimal treatment.

Predicting Outcome in Skull Base Osteomyelitis: An Assessment of Demographic, Clinical, and Pathological Attributes

Objective  Skull base osteomyelitis (SBO) is an enigmatic clinical diagnosis which is difficult to decipher and is associated with poor outcomes. The study aims to examine the demographic and clinical characteristics of patients with SBO and its outcomes.

Materials and Methods  Medical records of 30 patients with diagnosis of SBO over past 5 years were assessed for demographic and clinical characteristics, type of SBO, radiological parameters, treatment received, procedure performed, microbiological profile, comorbidities, and complications including cranial nerve (CN) palsies. These factors were analyzed for prediction of outcome (death or survival).

Statistical Analysis  Microsoft Office Excel 2010 SAS 10.0 for Windows was used. Student's t -test for continuous variables (age, duration of symptoms, number of days of hospitalization, and treatment duration) and chi-square test for categorical variables (imaging findings, symptomatology, presence of comorbidities, surgical procedure, complications, and type of antibiotics) were utilized.

Results  We found SBO was the disease of elderly population (64.07 ± 6.13 years) with male predominance (83.3%) highly associated with uncontrolled diabetes status (93.3%). Headache (100%) and CN palsy (80%) were the most common neurological presenting complaints followed by stroke (17%) and encephalopathy (10%). Pathological and radiological correlation showed that fungal infection ( Aspergillus ) was associated with anterior SBO (10%), while bacteria ( Pseudomonas ) was cultured from posterior SBO (30%). Fifty per cent of patients were alive after 1 year out of which 33% had good functional outcome. The mortality rate was 33.3% in our cohort and multiple lower CN palsies ( p  = 0.04), suboptimal duration of medical treatment ( p  = 0.03), surgical intervention during clinical course ( p  = 0.02), and development of intracranial or extracranial complications ( p  = 0.03) were the predictors of mortality.

Conclusion  Early diagnosis including identification of pathogenic organisms and optimal duration of treatment are crucial factors for improved outcomes in SBO.

Skull Base Osteomyelitis: A Diagnostic Dilemma

Skull base osteomyelitis is a rare but potentially fatal condition. It is often characterised by a series of non-specific clinical and radiological signs, making it difficult to distinguish from a malignant lesion. We present the case of an immunocompetent elderly gentleman with multiple cranial nerve palsies and an unremarkable initial ear examination, diagnosed and treated for skull base osteomyelitis, masquerading as malignancy. This initially regressed without antibiotic therapy. This case emphasises the importance of clinicians having a high degree of diagnostic suspicion in order to initiate prompt treatment, thereby improving patient prognosis.

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.

Incremental Role of 18F-FDG-Labeled Autologous Leukocyte PET/CT in Suspected Postoperative Recurrence of Skull Base Osteomyelitis

ABSTRACT

Skull base osteomyelitis is 1 of the complications of a middle ear infection seen mainly in immunocompromised individuals. A 3-phase bone scan and clinical, laboratory, and other radiological imaging are used for the diagnosis. However, in previously operated cases, bone scan findings are not reliable. We present a case of a 70-year-old man with persistent ear discharge postsurgery and with 3-phase bone scan negative for active infection. However, a subsequent 18F-FDG-labeled autologous leukocyte PET/CT study was able to diagnose the presence of active infection.

A Case of Atypical Central Skull Base Osteomyelitis with Bilateral Alveolar Bone Destruction

Central skull base osteomyelitis (CSBO) is a rare, fatal condition seen mostly in elderly diabetic or immunocompromised patients; it mainly involves the sphenoid or occipital bones and diagnosis is often delayed. A 72-year-old male with diabetes was referred to our department with severe pain in the maxillary gingiva. Endoscopic biopsy of the pterygoid bone confirmed the presence of mucormycosis combined with Klebsiella pneumoniae infection. Sinus surgery was performed with bilateral alveolar bone sequestrectomy. Long-term intravenous broad-spectrum antibiotic therapy using meropenem and ampicillin/sulbactam and antifungal therapy using amphotericin B (100 mg/day) was administered; an oral antifungal agent, posaconazole (800 mg/day), was also prescribed for 11 weeks. At the 6-month follow-up visit, there were no complications and no progression of the CSBO lesion was observed. Timely diagnosis and multidisciplinary treatment including endoscopic surgery, alveolar bone sequestrectomy, and combined antifungal and antibiotic therapy can reduce mortality and minimize complications associated with CSBO.

Malignant otitis externa: An updated review

Malignant otitis externa is a progressive infection of the external auditory canal and skull base. Pseudomonas aeruginosa is the most isolated microorganism and it affects mostly to diabetic, elderly, and immunocompromised individuals. Non-resolving otalgia and chronic otorrhea are the clinical manifestations presented. Facial nerve palsy is a common and well recognized complication. (Computed tomography) CT scan is useful for initial assessment, Technetium-99m is highly sensitive and is part of the protocol for diagnosis. Treatment should be individualized, with multidisciplinary cooperation among specialties. Management involves systemic antipseudomonal antibiotics and monitoring with radiologic techniques, it also involves the strict control of diabetes. It is essential to follow up the patients for at least a year post-treatment. In refractory malignant otitis externa and affection of facial nerve, surgical management is recommended. We reviewed the most recent studies on epidemiology, clinical manifestations, diagnosis, and treatment to provide an update on Malignant Otitis Externa that can offer an overview for clinical practice and future research.

Skull Base Osteomyelitis: A Comprehensive Imaging Review

Skull base osteomyelitis is a relatively rare condition, generally occurring as a complication of advanced otologic or sinus infection in immunocompromised patients. Skull base osteomyelitis is generally divided into 2 broad categories: typical and atypical. Typical skull base osteomyelitis occurs secondary to uncontrolled infection of the temporal bone region, most often from necrotizing external otitis caused by Pseudomonas aeruginosa in a patient with diabetes. Atypical skull base osteomyelitis occurs in the absence of obvious temporal bone infection or external auditory canal infection. It may be secondary to advanced sinusitis or deep face infection or might occur in the absence of a known local source of infection. Atypical skull base osteomyelitis preferentially affects the central skull base and can be caused by bacterial or fungal infections. Clinically, typical skull base osteomyelitis presents with signs and symptoms of otitis externa or other temporal bone infection. Both typical and atypical forms can produce nonspecific symptoms including headache and fever, and progress to cranial neuropathies and meningitis. Early diagnosis can be difficult both clinically and radiologically, and the diagnosis is often delayed. Radiologic evaluation plays a critical role in the diagnosis of skull base osteomyelitis, with CT and MR imaging serving complementary roles. CT best demonstrates cortical and trabecular destruction of bone. MR imaging is best for determining the overall extent of disease and best demonstrates involvement of marrow space and extraosseous soft tissue. Nuclear medicine studies can also be contributory to diagnosis and follow-up. The goal of this article was to review the basic pathophysiology, clinical findings, and key radiologic features of skull base osteomyelitis.

The challenging diagnosis and follow-up of skull base osteomyelitis in clinical practice

PURPOSE

The disease activity of skull base osteomyelitis can be challenging to assess by means of conventional imaging methods and renders monitoring of the disease difficult, especially in areas with restricted access to nuclear medicine imaging. Here, we provide clinically relevant data on the management of skull base osteomyelitis including assessment, treatment, and follow-up strategies with regards to the role of imaging.

METHOD

A chart review was performed including 30 patients treated for SBO from 1993 to 2015. Clinical findings, treatment procedures, and complication rates were assessed. Special attention was paid to imaging procedures.

RESULTS

The overall mortality rate was 36.7% and increased to 45% when cranial nerve palsies were present. An initial computed tomography (CT) scan was performed in all patients, MRI in 60% and nuclear imaging in 33%. CT scans failed to detect progression or regression in up to 80% after four to nine months. MRI examinations could reveal changes at a higher rate compared to CT. Nuclear medicine functional imaging was most likely to assess disease activity.

CONCLUSION

A combination of different imaging modalities is recommended for diagnosing SBO. For the follow-up, MRI is preferable to CT as changes can be detected more readily with MRI. If available, nuclear medicine imaging should guide the decision of treatment discontinuation.

Malignant otitis externa with subsequent internal jugular vein thrombosis and hypoglossal palsy: a report and review of literature

Inflammation of a part or whole of the temporal bone and surrounding soft tissue is termed as malignant otitis externa, which typically spreads to skull base to involve cranial nerves VII. Rarely can it also effect one or more of cranial nerves IX, X, XI, and XII. We present a case of malignant otitis externa which presented with symptomatic palsy of IX and XII nerves sparing the VII cranial nerve. The patient though later on had internal jugular vein thrombosis, which we presume is due to the involvement of the parapharyngeal space that prompted us to reconsider the diagnosis, and later on, to aggravate the therapy. With proper blood sugar control and appropriate long term antibiotics, not only that the patient is disease free at one year follow up, but the cranial nerve deficits also recovered. Apart from sharing the clinical and management details of this patient, we have reviewed the relevant literature in the discussion, which has shed some light onto some of the interesting facts about this condition and its prognosis.

Stenotrophomonas skull base osteomyelitis presenting as necrotizing otitis externa: Unmasking by CT and MRI-case report and review

Necrotizing or malignant otitis externa in patients presenting with mild clinical findings can pose as a tip of the iceberg; computed tomography (CT) and/or magnetic resonance imaging (MRI) unveils the clinical-imaging discrepancy and unmasks the presence of skull-base osteomyelitis (SBO). Pseudomonas aeruginosa is the most common causative pathogen of SBO, followed by fungal and other rare bacterial organisms. This report presents a rare case in an elderly diabetic patient, where the pathogen Stenotrophomonas maltophilia was isolated. There have been no previous reported cases in the literature of SBO caused by this pathogen. The hallmark of SBO on computed tomography or magnetic resonance imaging is soft tissue inflammatory changes under the central skull base with associated bone erosion. This may result in the peculiar appearance of the "Ovoid Gap" sign. SBO can be due to nonotogenic sources, namely: sinogenic, rhinogenic, pharnygogenic, or odontogenic infections. Low threshold for imaging is advised in immunosuppressed and elderly diabetic patients.