Insidious onset of headache, diplopia and Horner's syndrome: a rare case of petrous bone osteomyelitis.

We present an unusual case of skull base osteomyelitis in an 88-year-old woman. She presented with gradual onset unilateral headache and diplopia. On examination, there was evidence of a left-sided Horner's and ipsilateral sixth nerve palsy. In addition to persistent raised inflammatory markers, an MRI neck identified signal change in the petrous bone confirming a diagnosis of skull base osteomyelitis. Skull base osteomyelitis should be considered in presentations of subacute raised inflammatory markers in the context of ipsilateral cranial nerve signs.