Skull Base Osteomyelitis Diagnosis and Management

Clinical Presentation and Pathophysiology

• Isolated sphenoid sinusitis is rare (1-3% of sinonasal diseases) but carries high mortality and morbidity when diagnosis is delayed due to vague and nonspecific symptoms 1, 2
• Persistent throat pain can be a manifestation of skull base involvement due to the anatomical proximity of the sphenoid sinus to the skull base and pharynx 3

Diagnostic Challenges

• Sphenoid sinusitis can lead to serious complications including skull base osteomyelitis, cavernous sinus thrombosis, and intracranial spread of infection 1, 4

Risk Factors

• Immunocompromised status is a risk factor for developing SBO from sphenoid sinusitis 3

Diagnostic Approach

• MRA may be helpful if arteritis is suspected, as can be seen in the setting of sphenoid sinusitis and skull base osteomyelitis 5
• MRV or contrast-enhanced MRI should be considered if venous sinus thrombosis is suspected, as patients with sphenoid sinusitis are at risk for cavernous sinus thrombosis 5, 6

Management Considerations

• Early diagnosis and treatment are critical to prevent serious complications including cranial neuropathies, meningitis, cerebritis, and cerebral abscess 3
• Conservative treatment with long-term antimicrobials is the mainstay of treatment, with surgery reserved for biopsy, microbial sampling, or removal of necrotic tissue 3

Common Pitfalls and Caveats

• Isolated maxillary or sphenoid sinus opacification can be a marker of neoplasia in 18% and malignancy in 7-10% of patients, requiring a lower threshold for early surgical intervention 7
• Even asymptomatic sphenoid disease should not be ignored, as 16% of sphenoid fungal balls were associated with orbital infective complications 7