A 7-year-old girl with long-standing left ear discharge develops severe retro-orbital pain and double vision. Examination shows inability to abduct the left eye. The most likely diagnosis is:
- A Cavernous sinus thrombosis
- B Apical petrositis ✓
- C Otitic hydrocephalus
- D Lateral semicircular canal fistula
Correct answer: B. Apical petrositis
Explanation
Infection spreading to the petrous apex produces petrositis, giving Gradenigo's triad: persistent otorrhoea, retro-orbital pain from trigeminal irritation in Meckel's cave, and ipsilateral abducens palsy causing diplopia, since the sixth nerve runs over the petrous tip. Cavernous sinus thrombosis causes chemosis, proptosis and multiple ocular motor palsies rather than an isolated sixth nerve palsy. Otitic hydrocephalus presents with raised intracranial pressure and papilloedema, not diplopia from abduction failure.
Reference: Dhingra, Diseases of Ear, Nose and Throat, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.