Infection of CNS spreads to inner ear through: (A) Cochlear aqueduct, (B) Endolymphatic sac, (C) Vestibular aqueduct, (D) Hyle fissure
Answer is A. The scala tympani is closed by a secondary tympanic membrane. It is also connected with subarachnoid space through aqueduct of cochlea Reference: Dhingra 6th edition.