Central Skull Base Osteomyelitis: Multimodality Imaging and Clinical Findings from a Large Indian Cohort

Central or atypical skull base osteomyelitis (CSBO) often presents with severe unrelenting headache and progressive mono or polyneuritis cranialis. MRI and CT are used as initial imaging techniques but have a poor specificity and sensitivity.

To analyze our cohort of CSBO.

Over a 5-year period [2015-2020], we retrospectively analyzed the records of all patients with CSBO who had undergone a 3T MRI Brain, MR angiography, regional FDG PET-CT, and skeletal scintigraphy with 99mTc MDP/SPECT-CT. Surgical biopsy specimens were sent for bacterial and fungal cultures.

In total, 17 patients with CSBO were identified. Typically, 88% of patients presented with severe unilateral headache. All patients had at least a cranial mono or polyneuritis. The majority of patients were diabetic [64%]. MRI was normal in 42% of patients, whereas PET-CT and with 99mTc MDP scan and SPECT-CT were abnormal in all patients.

Our series of CSBO showed a 40% mortality rate with significant morbidity and relentless progression. Patients required repeated PET CT and bone scans to detect regression of disease activity. The average duration of IV therapy ranged from 3 weeks to 9 months and oral therapy for around 2-3 months. Cure was defined after taking into account the original diagnosis, symptom resolution, and concordant reduction of tissue uptake on PET CT and 99mTc bone scan. The combination of MRI, FDG PET CT, and 99mTc bone scan with concurrent SPECT CT was able to detect disease and disease progression in all patients.