A 10-year-old girl with long-standing left-sided foul-smelling ear discharge presents with diplopia worse on looking to the right, deep retro-orbital pain, and persistent aural discharge. Examination reveals an abducens nerve palsy on the left. The most likely diagnosis is:

• A Lateral sinus thrombosis with raised intracranial pressure
• B Bezold abscess with reflex orbital cellulitis
• C Gradenigo syndrome secondary to petrous apicitis ✓
• D Serous labyrinthitis with vestibular neuronitis

Explanation

Gradenigo syndrome is the classic triad of ipsilateral abducens palsy, severe retro-orbital pain (trigeminal involvement), and persistent otorrhoea, caused by spread of infection to the petrous apex (petrositis). The abducens nerve runs through Dorello canal beneath the petroclinoid ligament at the apex, hence the lateral rectus weakness. Bezold abscess causes mastoid tip swelling, not ocular palsy, and raised intracranial pressure from lateral sinus thrombosis causes papilloedema rather than isolated sixth nerve palsy.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.