CT cisternography in congenital perilymphatic fistula of the inner ear.

Perilymphatic fistulas of the inner ear constitute abnormal leaks of perilymphatic fluid into the middle ear or mastoid air cell system and represent a rare cause of otorrhea. We report the case of a 5-month-old child presenting with sudden otorrhea. High resolution CT cisternography showed a malformation of the middle ear and a passage of contrast-enhanced CSF into the tympanic cavity through the left oval window. Surgery confirmed a tear of the tympanic membrane as well as a stapes malformation with aplasia of the crura and an associated perilymphatic fistula through a defect in the stapes footplate. The fistula was closed with adipose tissue from the ear lobe.