A 1-year and 2-month-old-boy was referred to our hospital with a complaint of recurrent episodes of pneumonia, bronchitis and meningitis. His right eardrum was gray and had poor mobility due to middle ear effusion. Temporal bone CT and the inner ear three dimensional MRI showed hypoplasia of the right osseous labyrinth, which was diagnosed as Mondini dysplasia. These findings suggested the existence of abnormal communication between the cerebrospinal fluid space and the middle ear via the internal auditory canal and the inner ear, which resulted in cerebrospinal fluid otorrhea and meningitis. As penicillin-insensitive streptococcus pneumoniae (PISP) was detected from the fluid as well as the nasopharynx at the last episode of meningitis, we carried out exploratory tympanotomy after the eradication of PISP in the nasopharynx There was a bony defect at the center of the footplate of the stapes and pulsative outflow of the cerebrospinal fluid was observed. We plugged the inner ear space with soft tissues through the defect, covercd them with box dust and the periosteum and finally fixed them with fibrin glue. The patient's postoperative course was uneventful and he has not had any severe infectious diseases, including meningitis. This suggests that inner ear anomaly is one of the risk factors of repeated meningitis. For a good vital prognosis and also to prevent labyrinthitis of the contralateral ear caused by repeated meningitis, we concluded that early surgical treatment to close the fistula is important. In addition, the nasopharyngeal pathogens, in particular, drug-resistant bacteria, play a crucial role in the onset and persistence of otogenic meningitis.
