<prompt> The most common site of perilymph fistula -Round windowOval windowOtic capsuleAttic  <response>: Ans. is b i.e., Oval windowPerilymph fistulao In this condition, perilymph leaks into the middle ear through the oval or round window.o Perilymphatic fistula so positive fistula test may occur due to a defect in one of three locations:-1 Oval - window most common siteStapedectomy surgery for otosclerosisHead trauma or Barotrauma Pressure injuryAcoustic traumaRound window rupture of round window membraneBarotrauma SCUBA diving, airplane pressurizationCongenital malformations mondini dysplasiaOtic capsuleAnother possible location for a fistula is in the bone of the ear the otic capsule. This is a rare condition where the bone between the ear and brain area is missing or thin, causing symptoms very similar to that of round or oval window fistula. Causes areSuperior canal dehiscence syndromeCholesteatomaFenestration surgery surgically created window in horizontal SCCErosion of Horizontal lateral SCC due to any causeTemporal bone fractureMicro fissure 