Gradenigo’s syndrome: an old, but still alive, cause of sixth nerve palsy

Abstract

Introduction: Gradenigo Syndrome is characterized by suppurative otitis media, pain in the distribution of the trigeminal nerve, and abducens nerve palsy. Sixth nerve palsy is secondary to nerve entrapment through the Dorello canal, petroclinoid ligament and petrous apex of the temporal bone. It is a report of a single case based on a retrospective analysis of the patient’s medical records. Case report: A 12-year-old girl was admitted due to new-onset binocular horizontal diplopia, worse with far vision, and right-side headache. She also complained of otalgia and fever for one week before admission. She has an unremarkable past medical history and up-to-date vaccination. On her neurological examination, she was alert and oriented, there was right eye abduction palsy, reduced right corneal-palpebral reflex and pain in the distribution of the right ophthalmic branch of the trigeminal nerve; meningeal irritation signs were absent. Otoscopy revealed a tender right tympanic membrane. Brain and ear computed tomography revealed abnormal right temporal petrous apex aeration and opacification of the petromastoid air cells. Brain and ear magnetic resonance imaging show abnormal hyperintensity compatible with right petrous apicitis. Gradenigo syndrome secondary to otitis diagnosis was made. An empirically-guided intravenous antibiotic was started and a myringotomy tube was placed by the ENT team. The culture of the middle ear revealed a Streptococcus pneumoniae infection. The patient was discharged after 14 days with an improvement in neurological symptoms. Conclusion: Gradenigo syndrome is a cause of sixth nerve palsy. The syndrome is classically described after suppurative otitis media, but it has already been described after complications of trauma and skull-base metastases. Nowadays, it is more uncommon due to early and widespread treatment with antibiotics to avoid complications of otitis media.