Central skull base osteomyelitis secondary to invasive aspergillus sphenoid sinusitis presenting with isolated 12th nerve palsy

Atypical Skull-Base Osteomyelitis: Comprehensive Review and Multidisciplinary Management Viewpoints

Atypical skull-base osteomyelitis is a rare but fatal disease that usually involves infection of the ethmoid, sphenoid, occipital, or temporal bones that form the skull base. Unlike typical (so-called otogenic), atypical skull-base osteomyelitis has no otogenic cause. Instead, some authors call atypical skull-base osteomyelitis sinonasal, since the infection most often originates from the nose and paranasal sinuses. Diagnosing and treating this disease is challenging. To assist in managing atypical skull-base osteomyelitis, a review of the most recent literature, with patient cases and multidisciplinary perspectives from otolaryngologists, neurosurgeons, radiologists, infectious disease specialists, pathologists, and clinical microbiologists, is provided in this paper.

Successful treatment of vertebral osteomyelitis due to Aspergillus flavus in an immunocompetent patient

Aspergillus osteomyelitis (AO) is a rare and often lethal opportunistic infection in predominantly immunocompromised patients. Treatment has shifted from amphotericin therapy to voriconazole monotherapy due to increased effectiveness and less toxicity. We report a case of an immunocompetent woman with vertebral osteomyelitis due to Aspergillus flavus who was successfully treated with surgery (requiring hardware implantation) and monotherapy posaconazole (following intolerance and hepatitis due to voriconazole). She remained well at follow-up post cessation of 12 months of antifungal therapy. We provide an updated literature review examining the role of azole monotherapy as the gold standard of treatment for AO.

The Hypoglossal nerve

The hypoglossal nerve is the 12th cranial nerve, exiting the brainstem in the preolivary sulcus, passing through the premedullary cistern, and exiting the skull through the hypoglossal canal. This is a purely motor nerve, responsible for the innervation of all the intrinsic tongue muscles (superior longitudinal muscle, inferior longitudinal muscle, transverse muscle, and vertical muscle), 3 extrinsic tongue muscles (styloglossus, hyoglossus, and genioglossus), and the geniohyoid muscle. Magnetic resonance imaging (MRI) is the best imaging exam to evaluate patients with clinical signs of hypoglossal nerve palsy, and computed tomography may have a complementary role in the evaluation of bone lesions affecting the hypoglossal canal. A heavily T2-weighted sequence, such as fast imaging employing steady-state acquisition (FIESTA) or constructive interference steady state (CISS) is important to evaluate this nerve on MRI. There are multiple causes of hypoglossal nerve palsy, being neoplasia the most common cause, but vascular lesions, inflammatory diseases, infections, and trauma can also affect this nerve. The purpose of this article is to review the hypoglossal nerve anatomy, discuss the best imaging techniques to evaluate this nerve and demonstrate the imaging aspect of the main diseases that affect it.

The Glossopharyngeal, Vagus and Accessory nerves: Anatomy and Pathology

The glossopharyngeal, vagus, and accessory nerves are discussed in this article, given their intimate anatomical and functional associations. Abnormalities of these lower cranial nerves may be intrinsic or extrinsic due to various disease processes. This article aims to review these nerves' anatomy and demonstrates the imaging aspect of the diseases which most commonly affect them.

Mycotic clival osteomyelitis secondary to immunosuppression by SARS-CoV-2

Background:

During the past 2 years, the use of systemic corticosteroids has increased due to COVID-19 atypical pneumonia management. Similarly, an increase in mycotic infection cases has been reported during the same period as a consequence of immunosuppression caused by corticosteroid overuse. Mycotic clival osteomyelitis is a rare clinical entity which presumably has increased its incidence during the pandemic.

Case Description:

A 52-year-old woman who presented persistent headaches and unexplained weight loss after being hospitalized due to COVID-19 pneumonia treated with intravenous corticosteroids. Head computed tomography and magnetic resonance imaging showed extensive osteomyelitis at the clival region with no brain parenchyma involvement. Surgical excision through navigation-guided transnasal transclival endoscopic extended approach was performed for surgical debridement. Histopathological analysis revealed angulated hyphae, suggestive of Aspergillosis. Systemic antifungal treatment was administered for 30 consecutive days. Afterward, she was discharged without any remarkable neurological findings, reassessed during follow-up.

Conclusion:

The COVID-19 pandemic has had an effect on the reemergence of mycotic infections due to corticosteroid immunosuppression. Clival osteomyelitis secondary to mycotic infection is an exclusion diagnosis that we encourage to be highly suspected within the persisting COVID-19 pandemic.

Aspergillus spp. osteoarticular infections: an updated systematic review on the diagnosis, treatment and outcomes of 186 confirmed cases

Aspergillus spp. osteoarticular infections are destructive opportunistic infections, while there is no clear consensus on their management. The purpose of this review is to investigate the current literature regarding Aspergillus spp. osteoarticular infections. An electronic search of the PubMed and Scopus databases was conducted considering studies that assessed osteoarticular infections from Aspergillus spp. We included only studies with biopsy proven documentation of positive cultures or histological findings for Aspergillus spp., and those with essential information for each case such as the anatomical location of the infection, the type of treatment (conservative, surgical, combination), the antifungal therapy, and the outcome. Overall, 148 studies from 1965 to 2021 including 186 patients were included in the review. One hundred and seven (57.5%) patients underwent surgical debridement in addition to antifungal therapy, while 79 (42.7%) patients were treated only conservatively. Complete infection resolution was reported in 107 (57.5%) patients, while partial resolution in 29 (15.5%) patients. Surgical debridement resulted in higher complete infection resolution rate compared to only antifungal therapy (70.0% vs. 40.5%, P < 0.001), while complete resolution rate was similar for antifungal monotherapy and combination/sequential therapy (58.3% vs. 54.5%; P = 0.76). Last, complete resolution rate was also similar for monotherapy with amphotericin B (58.1%) and voriconazole (58.6%; P = 0.95). The results of this study indicate that antifungal monotherapy has similar efficacy with combination/sequential therapy, while voriconazole has similar efficacy with amphotericin B. Moreover, surgical debridement of the infected focus results in better outcomes in terms of infection eradication compared to conservative treatment.

LAY SUMMARY

Antifungal monotherapy has similar efficacy with combination/sequential therapy, and voriconazole has similar efficacy with amphotericin B for the treatment of Aspergillus spp. osteoarticular infections, while surgical debridement of the infected focus improves the infection eradication rate.

A practical overview of CT and MRI features of developmental, inflammatory, and neoplastic lesions of the sphenoid body and clivus

The sphenoid bone is an unpaired bone that contributes to the formation of the skull base. Despite the enormous progress in transnasal endoscopic visualisation, imaging techniques remain the cornerstones to characterise any pathological condition arising in this area. In the present review, we offer a bird’s-eye view of the developmental, inflammatory, and neoplastic alterations affecting the sphenoid body and clivus, with the aim to propose a practical diagnostic aid for radiologists based on clinico-epidemiological, computed tomography, and magnetic resonance imaging features.