Central Skull Base Osteomyelitis: Diagnostic Dilemmas and Management Issues

Abstract

The aim of this study is to describe the clinical presentation of central skull base osteomyelitis and to discuss the classical imaging findings and various diagnostic and therapeutic challenges faced in the management of this condition. This is a retrospective analysis of inpatient case records, carried out in a multidisciplinary tertiary care hospital. The study subjects included five elderly diabetic patients presenting to the ENT surgeon or neurologist with headache followed by multiple cranial nerve paralysis with no temporal bone involvement in four patients and a past history of otitis externa in one patient. These patients were diagnosed to have an infective pathology of the central skull base detected by imaging and confirmed by biopsy in three. All were treated successfully with antibiotics administered for an average period of 6 weeks. Three patients followed up over 4 years and showed no relapses. One succumbed to other medical co morbidities after 8 months and one diagnosed a month prior is still under follow up. A symptom complex of headache and cranial neuropathies usually raises the suspicion of malignancy. Central skull base osteomyelitis, a relatively uncommon pathology, must also be considered as a possible differential diagnosis despite absence of a definite septic focus. Imaging studies showing bony destruction and adjacent soft tissue involvement should raise the suspicion of this clinical entity. Malignancy needs to be ruled out by biopsy. Early diagnosis and prompt initiation of antibiotics administered for an adequate duration is of paramount importance in successfully treating these patients. A multidisciplinary approach is needed for a successful outcome.

Keywords: Central skullbase; Clivus; Cranial neuropathies; Osteomyelitis.

Fig. 1

Endoscopic view showing a nasopharyngeal abscess (asterisk) and Eustachian tube opening (ET)

Fig. 2

Post contrast fat saturated axial T1 weighted image through the skull base showing a thick walled irregular peripherally enhancing abscess in the mid line retropharyngeal region (asterisk) with erosion of bilateral petrous apices marked by arrow

Fig. 3

T1 weighted axial image revealing loss of normal marrow signal in the clivus (asterisk) with peri clival soft tissue

Fig. 4

Axial CT scan showing ill-defined bone destruction involving the anterior and right lateral margin of the clivus marked by arrow

Fig. 5

Post contrast axial T1 weighted image showing enhancing abnormal marrow signal in the clivus (arrow) and associated abnormal enhancing soft tissue in the right para clival region and along the petrous apex (asterisk)