Recurrent bacterial meningitis after cochlear implantation in a patient with a newly described labyrinthine malformation.

Authors report on a so far undescribed bilateral inner ear malformation with congenital deafness where a defect of both the medial and lateral bony labyrinthine wall allowed the herniation of a cerebrospinal fluid-filled endosteum sac into the tympanic cavity. The story of cochlear implantation in this ear and the series of following meningitis demonstrates the dilemma of indicating implantation in labyrinthine dysplasia and the difficulties of treating postimplantation meningitis. Routes of bacterial invasion from inner ear to intracranium is discussed regarding normal, dysplastic and surgically "disturbed" inner ear anatomy.