<prompt> Most potential route for spread of infection from CNS to inner earVestibular aqueductCochlear aqueductEndolymphatic sacHyle fissure  <response>: Cochlear aqueduct is most potential route for spread of infection from CNS to inner earQ Cochlear aqueduct vestibular aqueduct are 2 bony channels canals that connect inner ear cochlea vestibule respectively to intracranial sub arachnoid space. Vestibular aqueduct contains endolymphatic duct filled with endolymph, which does not communicate freely with CSF as it ends in a cul de sac and forms a closed space. Whereas perilymph filled cochlear aqueduct is in direct continuation with the CSF which makes it a most potential route of infection. Hyles fissure is present in early embryonic life that normally obliterates by 24 weeks of gestation. When persistent it provides a connection from middle ear to subarachnoid space. 