Central skull base osteomyelitis in patients without otitis externa: imaging findings.
OBJECTIVE
Skull base osteomyelitis typically arises as a complication of ear infection in older diabetic patients, involves the temporal bone, and has Pseudomonas aeruginosa as the usual pathogen. Atypical skull base osteomyelitis arising from the sphenoid or occipital bones without associated external otitis occurs much less frequently and initially may have headache as the only symptom. The purpose of this study was to review the clinical and MR imaging features of central skull base osteomyelitis.


METHODS
We retrospectively reviewed MR images obtained in six patients with central skull base osteomyelitis. No patient had predisposing external otitis or osteomyelitis of the temporal bone.


RESULTS
All of our patients presented with headache, no external ear pain, and cranial nerve deficits. Five of six patients had a predisposition to infection, and the erythrocyte sedimentation rate was elevated in the five patients in whom it was checked. In each case, the diagnosis was delayed until MR imaging demonstrated central skull base abnormality, and the diagnosis was then confirmed with tissue sampling. The most consistent imaging findings were clival bone marrow T1 hypointensity and preclival soft tissue infiltration. Five of six patients were cured with no recurrence of skull base infection over a 2-4-year follow-up period.


CONCLUSIONS
In the setting of headache, cranial neuropathy, elevated erythrocyte sedimentation rate, and abnormal clival imaging findings, central skull base osteomyelitis should be considered as the likely diagnosis. Early tissue sampling and appropriate treatment may prevent or limit further complications such as intracranial extension, empyema, or death.
Chang
Patrick C
PC
Department of Radiology, University of California, San Francisco, School of Medicine, San Francisco, CA 94143, USA.
Fischbein
Nancy J
NJ
Holliday
Roy A
RA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001799:Blood Sedimentation; D003389:Cranial Nerve Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D005710:Gallium Radioisotopes; D006801:Humans; D007275:Injections, Intravenous; D007958:Leukocyte Count; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009518:New York; D010019:Osteomyelitis / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D010032:Otitis Externa / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D019275:Radiopharmaceuticals; D012008:Recurrence; D012189:Retrospective Studies; D019291:Skull Base / Q000000981:diagnostic imaging / Q000473:pathology; D013667:Technetium; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D005710:Gallium Radioisotopes; D019275:Radiopharmaceuticals; D013667:Technetium