<prompt> Gradenigos syndrome is due to -MastoiditisPetrositisSigmoid sinus thrombophlebitisLabyrinthitis  <response>: Ans. is b i.e., Petrositis Petrositiso Infection of mastoid and middle ear may be complicated by the spread of infection within the temporal bone into petrous apex.o Petrositis is an extension of infection from middle ear and mastoid to the petrous part of the temporal bone, o Gradenigos syndrome is the classical presentation and consists of a triad of: -External rectus palsy Vlth nerveabducent nerve palsy causing diplopia.Deep seated orbital or retroorbital pain Vth nerve involvement.Persistent ear discharge due to ipsilateral acute or chronic otitis media.o Associated symptoms of otitis media are also present e.g., conductive deafness.o Other symptoms are fever, headache, vomiting, and sometimes neck rigidity.o Some patient may get facial paralysis and recurrent vertigo due to involvement of facial and statoacoustic nerves. 