Abstract
Skull base osteomyelitis typically arises as a complication of otogenic or sinonasal infections in immunocompromised patients. A much rarer entity, atypical skull base osteomyelitis is not associated with an obvious infective source. Atypical and culture-negative skull base osteomyelitis is even rarer and hampers diagnosis, as its clinical presentation is remarkably similar to skull base neoplasms. We report a case of extensive skull base osteomyelitis with orbital apex syndrome and multiple lower cranial nerve palsies which initially masqueraded as possible advanced nasopharyngeal carcinoma. Extensive investigations and consult with an infectious diseases specialist aided in elucidation of the correct diagnosis. Through this article, we emphasize that skull base osteomyelitis must be considered in the setting of headache, cranial neuropathies, elevated inflammatory markers and abnormal imaging findings. Early tissue sampling for histology, stainings and cultures and prompt appropriate treatment may prevent or arrest further complications.
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Introduction
Skull base osteomyelitis (SBO) is an infection of the bone and/or bone marrow of the calvarium, typically caused by bacteria or fungal invasion from sinonasal and otological sources . Most commonly seen in immunocompromised individuals and usually associated with malignant otitis externa, SBO is a rare but potentially fatal condition. Mortality from SBO complications ranges from 20 to 40% but early diagnosis and appropriate treatment of SBO can prevent or arrest neurologic deficits and reduce morbidity and mortality significantly . In this article, we describe a rare case of extensive atypical culture-negative skull base osteomyelitis with orbital apex syndrome and multiple cranial nerve palsies which initially masqueraded as nasopharyngeal carcinoma. The diagnostic, management and therapeutic options are discussed.
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Case report
A 54-year old Chinese gentleman presented with left-sided headache of several months’ duration and a sudden loss of vision in his left eye 2 days prior to his presentation to our clinic. There was no history of fever and ear or sinonasal infection. Apart from hypertension, dyslipidemia and well-controlled type II diabetes mellitus, he had no significant personal or family medical history.
Physical examination revealed no perception to light and a grade 3 relative afferent pupillary defect in his left eye. While the patient had denied any other symptoms, he was noted to have left eye ptosis, proptosis, dense ophthalmoplegia of left cranial nerves III, IV and VI, voice hoarseness and slurring of speech. Ipsilateral left hypoglossal nerve palsy was present with absent gag reflex ( Fig. 1 ). Fibreoptic nasoendoscopy showed a left vocal cord palsy and a slight bulge in the left nasopharynx with a normal looking mucosa. There was no evidence of sinusitis. Further complete neurological examination revealed sparing of the left cranial nerves V, VII, VIII and XI. All right-sided cranial nerves were intact. Otoscopy was unremarkable.
