The routes of infection spread in central skull-base osteomyelitis and the diagnostic role of CT and MRI scans.

BACKGROUND: Central skull-base osteomyelitis (CSBO) represents a life-threatening complication of external ear canal infection. Computed tomography (CT) and magnetic resonance imaging (MRI) play key roles in assessment of CSBO progression. METHODS: Twelve patients with CSBO were included in a retrospective clinical study. In total, 62 scans (30 CTs and 32 MRIs) were performed to evaluate the extent of inflammatory changes. The scans were read independently by two radiologists specialised in imaging of the head and neck. The regions under the skull base were specified using the online Anatomy Atlas of the skull base. To clarify the timeline, the time period was divided into four parts, and inflammatory changes in the skull-base regions were tracked. Data were statistically analysed. RESULTS: In early stages of the disease, CT scan detects inflammatory changes closely related to the stylomastoid foramen and medially to the posterior belly of the digastric muscle, changes which have been proved to be crucial for the diagnosis of CSBO. Later the infection spreads to the contralateral side causing demineralisation of the bones. CONCLUSION: Imaging methods play a crucial role not only in establishing the diagnosis, but also in anticipating the direction of infection spread underneath the skull base.

Uncontrolled spread following radiosurgery for a skull base aspergilloma misdiagnosed as schwannoma: is radiosurgery responsible?

BACKGROUND: Little is known about the natural history of skull base fungal lesions in immunocompetent individuals and the effect of high-dose radiation on fungal lesions. METHOD AND RESULTS: We report a case where radiosurgery was given to a skull base aspergilloma, mistaking it to be a trigeminal schwannoma. There was dramatic spread of the lesion to periventricular region with significant increase in the skull base lesion. The patient never received steroids. A stereotactic biopsy established the diagnosis, and treatment with voriconazole helped. CONCLUSIONS: It is possible that radiosurgery decreases local immunity due to vascular sclerosis and aids in spread of the fungal lesion, though it is only speculative. This again highlights the importance of establishing the diagnosis prior to radiosurgery.

[CHRONIC OSTHEOMYELITIS OF THE FACIAL MIDDLE ZONE WITH SPREADING ON THE BONES OF CRANIAL BASE ON BACKGROUND OF NARCOTIC DEPENDENCE].

Own experience of treatment of a narcotic dependence patients, suffering osteomyelitis of jaws, was analyzed. In those patients, who have had exposed themselves towards toxic impact of narcotic substances (even after arrest of the consumption) for a long period of time, the inflammation spreading on the bones of facial middle zone and the skull base with occurrence of a life3threatening purulent3septic, including intracerebral, complications (cerebral аbscess, meningitis, sepsis) were observed. Additional division of cerebral abscess on open and closed forms for optimization of diagnosis of іntracranial complications was proposed.

Th17 cytokine deficiency in patients with Aspergillus skull base osteomyelitis.

BACKGROUND: Fungal skull base osteomyelitis (SBO) is a severe complication of otitis externa or sinonasal infection, and is mainly caused by Aspergillus species. Here we investigate innate and adaptive immune responses in patients with Aspergillus SBO to identify defects in the immune response that could explain the susceptibility to this devastating disease. METHODS: Peripheral blood mononuclear cells isolated from six patients with Aspergillus SBO and healthy volunteers were stimulated with various microbial stimuli, among which also the fungal pathogens Candida albicans and Aspergillus fumigatus. The proinflammatory cytokines IL-6, TNFα and IL-1ß, and the T-helper cell-derived cytokines IFNγ, IL-17 and IL-22 were measured in cell culture supernatants by ELISA. RESULTS: Proinflammatory cytokine responses did not differ between SBO patients and healthy volunteers. The Candida- and Aspergillus-specific Th17 response (production of IL-17 and IL-22) was significantly decreased in the SBO patients compared to healthy individuals, while Th1 cytokine response (IFNγ production) did not differ between the two groups. CONCLUSIONS: We show that patients with Aspergillus skull base osteomyelitis infection have specific defects in Th17 responses. Since IL-17 and IL-22 are important for stimulating antifungal host defense, we hypothesize that strategies that have the ability to improve IL-17 and IL-22 production may be useful as adjuvant immunotherapy in patients with Aspergillus SBO.

Pseudotumoral allergic fungal sinusitis with skull base involvement.

Here we report a case of pseudotumoral recurrence of allergic fungal sinusitis with involvement of the skull base that was successfully treated with systemic corticosteroids and itraconazole without surgery. This report discusses the sometimes misleading radiological and clinical features as well as the diagnostic and therapeutic challenges of a condition that should be recognized by ENT specialists, neurosurgeons, ophtalmologists and radiologists.

[Two cases of allergic fungal rhinosinusitis with bone destruction].

We report herein two cases of allergic fungal rhinosinusitis accompanied by bone destruction of the adjacent nasal sinuses. The first case involved a 21-year-old man who presented with left exophthalmos. Computed tomography (CT) showed soft tissue lesions in the left paranasal sinuses and destruction of the left lamina papyraceae, as well as infiltration of the lesion into the orbit. In the second case, a 39-year-old man, CT showed bone destruction of the skull base and medial wall of the left orbit. In both cases, total serum immunoglobulin (Ig)E level was >1000 IU/mL and fungus-specific IgEs were increased. Fungal hyphae were identified within the mucus on histopathological examination in both cases; however, no fungal invasion of the mucosa was apparent. Final diagnosis was allergic fungal rhinosinusitis (AFRS) in both cases. AFRS is a relatively new disease concept that was proposed in the early 1980s, with disease characteristics very similar to eosinophilic rhinosinusitis. Occasionally, AFRS must be differentiated from malignant disease or invasive fungal rhinosinusitis, so an understanding of the clinical features is important.

Granulomatous Inflammation of the Skull Base: A Rare Case of Mycobacterium tuberculosis in the United States.

The differential for an ill-defined, bone-destructive, granulomatous lesion of the skull base includes malignancy, as well as autoimmune and infectious processes. Suspicion for tuberculosis of the skull base in high-risk patients is particularly necessary given the difficulty to culture on standard cultures, need for specific and prolonged antibiotic therapy, and dire morbidity if not diagnosed and treated in a timely manner. Repeat biopsies and cultures were necessary to diagnose this case of Mycobacterium tuberculosis of the skull base after initial biopsy was non-diagnostic. Laryngoscope, 134:4023-4027, 2024.

A rare cause of malignant otitis externa and skull base osteomyelitis.

An elderly male with type 2 diabetes presented with a 2-month history of otalgia and severe headaches. He was diagnosed with malignant otitis externa (MOE) and was commenced on empirical treatment with oral ciprofloxacin. Pseudomonas is the most common cause of MOE. A baseline CT scan was undertaken that demonstrated skull base osteomyelitis (SBO) due to findings of bone erosion at the mastoid tip and an infiltrating soft tissue mass eroding the clivus. Eight weeks later, he returned with worsening and bilateral symptoms of otitis externa, hearing loss, temporomandibular pain and dysfunction. Worsening and now bilateral malignant otitis externa were confirmed with an MRI scan that also demonstrated a small fluid collection in his left temporal region. The collection was aspirated and grew scedosporium apiospermum. He was diagnosed with fungal SBO and was commenced on treatment with the antifungal voriconazole, with significant improvement in symptoms and radiological findings. Fungal osteomyelitis is more likely in immunosuppressed patients, particularly those with type 2 diabetes. Fungal aetiology should be suspected in patients with progressive symptoms, despite treatment. A microbiology diagnosis of fungal SBO or MOE can be challenging to obtain and can lead to diagnostic delay. A sampling of the external auditory canal can aid in diagnosing MOE; however, scedosporium may also be isolated as a commensal organism. Aspirations from accessible fluid collections, infratemporal fossa needle sample and bone biopsy can provide material for diagnosis. Scedosporium is a rare cause of disease in humans, however, fungal infections are increasing in humans, due to an increase in susceptible populations. Scedosporium apiospermum is a rare cause of SBO and should be considered in patients not responding to standard treatment.

Sphenoidal-clival neoformation: an endoscopic approach.

The cranial base has distinct embryologic origins. The anterior cranial base is derived solely from the neural crest, similar to other facial bones, whereas the posterior cranial base is formed by the paraxial mesoderm. Both these parts also develop and grow with distinct features. Unlike other craniofacial bones that are mostly formed through intramembraneous ossification, the cranial base is formed through endochondral ossification, in which a cartilage plate, known as the chondrocranium, is formed first and soon replaced by bones. Individual bones are then connected by cartilaginous structures, termed synchondroses, which are morphologically similar to long-bone growth plates.These processes justify the presence of a disembryogenic cyst in the sphenoid bone. The authors present a case of a clival-sphenoidal region neoformation treated with a transnasal-endoscopic approach.

Skull Base Fungal Osteomyelitis: A Case Report and Review of the Literature.

Skull base osteomyelitis (SBO) is an invasive infection refractory to therapy, closely linked with malignant otitis externa (MOE). It is characterized by a mild clinical presentation that can delay cross-sectional imaging considered as the key to revealing it. Skull base osteomyelitis typically affects elderly diabetics and immunocompromised patients (>70 years). It most commonly has an otogenic origin due to an extension of MOE. The prognosis can be very poor without the administration of adequate and timely therapy at an early disease stage. Nowadays, Pseudomonas aeruginosa remains the most common pathogen associated with SBO. Fungi are a rare cause of MOE. This report documents a rare case of otogenic SBO caused by Candida parapsilosis in a diabetic patient, with persistent otologic symptoms as clinical onset and resistance to medical treatment. Fungal MOE has more subtle symptoms and is more aggressive than its bacterial counterpart. When MOE is resistant to antibacterial drugs, this should raise the suspicion of a fungal etiology of MOE. The current guidelines do not exhaustively describe the diagnosis, antifungal drugs of choice, and optimum duration of treatment. The description of these rare clinical cases should help with the multidisciplinary management of this disease in order to optimize the diagnosis and therapeutic protocol.

Polymicrobial Skull Base Osteomyelitis Related to Chronic Sphenoiditis and Endoscopic Sinus Surgery.

Skull base osteomyelitis (SBO) secondary to endoscopic surgery for chronic sinusitis and post-operative sphenopalatine artery electrocautery has not been previously reported. This case report details an instance of Central SBO with an unusual microbiology profile and highlights the need to readily consider SBO should patients present with persistent headache and cranial nerve palsies following sinus surgery. Laryngoscope, 131:E1086-E1087, 2021.

Skull base osteomyelitis with secondary cavernous sinus thrombosis: a rare presentation of an animate foreign body in the ear.

A 42-year-old woman presented with fever, left ear pain, restricted mouth opening, difficulty in swallowing and inability to open her left eyelid for a period of 10 days. She was treated with antibiotics for the same at a local medical facility; however, a sudden decrease in her left eye vision prompted her to visit our tertiary centre. Her history was insignificant except for having multiple left ear syringing for an insect removal 10 days before onset of her current symptoms. On examination, she had ptosis of the left eye with chemosis, dilated pupil with only perception of light and restricted ocular mobility. Oral examination revealed trismus and bulge in the left peritonsillar region. Left ear examination revealed a large central perforation with mucopurulent discharge. CT of the neck with contrast demonstrated a collection in the left peritonsillar space with left internal carotid artery thrombosis. MRI of the brain with gadolinium revealed left cavernous sinus thrombosis with acute infarcts in the left frontal lobe. An emergency incision and drainage of the left peritonsillar abscess was performed. Culture grew broad aseptate fungal hyphae. Despite starting on antifungal therapy, she succumbed to her illness.

Skull base infection presenting with multiple lower cranial nerve palsies.

Diseases of the temporal bone causing lower cranial nerve palsies are uncommon. In the presence of bony erosion, they are highly suggestive of a malignant process. However, when there is a clear history of otitis externa in an immunocompromised or diabetic patient, a diagnosis of osteomyelitis and secondary inflammatory mass should be considered. We report 4 separate cases of infective skull base lesions causing multiple lower cranial nerve palsies in elderly patients who were not immunocompromised or diabetic, highlighting that this condition is not exclusive to this population.

Craniocerebral aspergillosis: a review of advances in diagnosis and management.

Craniocerebral aspergillosis is a rare but dangerous central nervous system infection. The infection has a spectrum of presenting features, mostly affecting immunocompromised individuals. The incidence appears to be on the rise that has been especially observed in the immunocompetent population. A high index of suspicion, a comprehensive understanding of the infectious process and advanced laboratory and radiological diagnostic techniques, allow early diagnosis. Surgery, followed by systemic antifungal medications, remains the cornerstone of management. Early administration of empirical anti-fungal agents along with immunomodulators may further improve prognosis. Immunocompetent patients tend to have better outcomes as compared to those who are immunocompromised. Patients with intradural disease carry the worst prognosis.

Tracking down the White Plague: The skeletal evidence of tuberculous meningitis in the Robert J. Terry Anatomical Skeletal Collection.

Paleopathological diagnosis of tuberculosis (TB) essentially relies on the identification of macroscopic lesions in the skeleton that can be related to different manifestations of TB. Among these alterations, granular impressions (GIs) on the inner skull surface have been considered as pathognomonic features of tuberculous meningitis (TBM). GIs may be established by pressure atrophy of the tubercles formed on the outermost meningeal layer during later stages of TBM. Although GIs were used as diagnostic criteria for TBM in the paleopathological practice since the late 20th century, their diagnostic value has been questioned. To contribute to strengthening the diagnostic value of GIs, a macroscopic investigation-focusing on the macromorphological characteristics and frequency of GIs-was performed on skeletons of known cause of death from the Terry Collection. The χ2 analysis of our data revealed that GIs were significantly more common in individuals who died of TB than in individuals who died of non-TB causes. Furthermore, GIs were localized on the inner surface of the skull base and of the lower lateral skull vault. The localization pattern and distribution of GIs on the endocranial surface resemble that of the tubercles observed in the affected meninges during the pathogenesis of TBM. Our results strengthen the tuberculous origin of GIs and imply that they can be considered as specific signs of TBM. Therefore, GIs can be used as diagnostic criteria for TBM in the paleopathological practice, and the diagnosis of TBM can be established with a high certainty when GIs are present in ancient human bone remains.

Mycobacterium chelonae infections involving the head and neck.

OBJECTIVES: We describe the manifestations, diagnosis, and treatment of rare head and neck infections caused by Mycobacterium chelonae, including a case of maxillary osteitis and skull base osteomyelitis. METHODS: A comprehensive literature search (MEDLINE from 1951; BIOSIS from 1969; EMBASE from 1980) was performed for the presentation, diagnostic evaluation, and outcomes of patients with M chelonae infections. RESULTS: We report 4 cases of M chelonae infection, including a nasal abscess following septorhinoplasty with a cartilaginous graft, a case of chronic unilateral nasal obstruction, and the first reported cases of skull base osteomyelitis and maxillary osteitis secondary to M chelonae. All 4 cases involved immunocompetent individuals. CONCLUSIONS: Mycobacterium chelonae should be considered in cases of abscesses that persist despite broad-spectrum intravenous antibiotics, and in cases of maxillary sinusitis with bony involvement that do not respond to traditional treatment methods.

Extensive Skull Base Osteomyelitis Secondary to Malignant Otitis Externa.

Skull base osteomyelitis is a severe complication of malignant otitis externa that affects the marrow of the temporal, sphenoid, and occipital bones. Skull base osteomyelitis is usually diagnosed based on clinical, microbiological, and radiological findings. Here, we present the imaging findings of a 76-year-old man who initially presented with right-sided malignant otitis externa, with the involvement of the otomastoid structures and ipsilateral temporal bone. Over the following 3 years, despite specific extended antibiotic therapy, the skull base osteomyelitis entirely involved the skull base, up to the contralateral petrous portion of the temporal bone, and it affected the cervical vertebral processes. This report describes an exceptional extent of unilateral malignant otitis externa with a severe involvement of the skull base on the contralateral side and the cervical spine.

Atypical Form of Cervicofacial Actinomycosis Involving the Skull Base and Temporal Bone.

BACKGROUND:: Cervicofacial actinomycosis is an uncommon indolent infection caused by Actinomyces spp that typically affects individuals with innate or adaptive immunodeficiencies. Soft tissues of the face and neck are most commonly involved. Actinomyces osteomyelitis is uncommon; involvement of the skull base and temporal bone is exceedingly rare. The authors present a unique case of refractory cervicofacial actinomycosis with development of skull base and temporal bone osteomyelitis in an otherwise healthy individual. METHODS:: Case report with literature review. RESULTS:: A 69-year-old man presented with a soft tissue infection, culture positive for Actinomyces, over the right maxilla. Previous unsuccessful treatment included local debridement and 6 weeks of intravenous ceftriaxone. He was subsequently treated with conservative debridement and a prolonged course of intravenous followed by oral antibiotic. However, he eventually required multiple procedures, including maxillectomy, pterygopalatine fossa debridement, and a radical mastoidectomy to clear his disease. Postoperatively he was gradually transitioned off intravenous antibiotics. CONCLUSIONS:: Cervicofacial actinomycosis involves soft tissue surrounding the facial skeleton and oral cavity and is typically associated with a history of mucosal trauma, surgery, or immunodeficiency. The patient was appropriately treated but experienced disease progression and escalation of therapy. Although actinomycosis is typically not an aggressive bacterial infection, this case illustrates the need for prompt recognition of persistent disease and earlier surgical intervention in cases of recalcitrant cervicofacial actinomycosis. Chronic actinomycosis has the potential for significant morbidity.

Non-invasive fungal sinusitis resulting in multiple cranial nerve neuropathies.

A 33-year-old man presented to the emergency department with a right-sided facial paralysis and maxillary division (V2, trigeminal nerve) paraesthesia. He had been suffering with upper respiratory tract symptoms in the preceding 2 months, including rhinorrhoea, fever and headache. The patient was otherwise fit and immunocompetent. Urgent radiological investigation revealed extensive fungal sinusitis with sphenoid sinus dehiscence and skull base osteitis. The patient underwent emergency endoscopic sinus surgery revealing concretions and debris in the ethmoid and sphenoid sinuses. He was commenced on systemic antifungal therapy and made a full recovery with resolution of his cranial neuropathies. The fungus Schizophyllum commune was isolated and is a rare cause of fungal sinusitis, but with the potential for invasive disease in immunosuppressed individuals.

Insidious onset of headache, diplopia and Horner's syndrome: a rare case of petrous bone osteomyelitis.

We present an unusual case of skull base osteomyelitis in an 88-year-old woman. She presented with gradual onset unilateral headache and diplopia. On examination, there was evidence of a left-sided Horner's and ipsilateral sixth nerve palsy. In addition to persistent raised inflammatory markers, an MRI neck identified signal change in the petrous bone confirming a diagnosis of skull base osteomyelitis. Skull base osteomyelitis should be considered in presentations of subacute raised inflammatory markers in the context of ipsilateral cranial nerve signs.