[Cerebrospinal fluid leak due to inner ear malformations].

A case of inner ear anomalies associated with recurrent meningitis found in a 66-year-old female is reported. The patient had had 2 episodes of meningitis in the previous one year period. Multidetector-row CT of the temporal bone and three-demensional fast imaging employing steady-state acquisition MRI revealed dysplasia of the bony labyrinth and enlarged fundus of the internal auditory canal (IAC). During surgical treatment, we confirmed the cerebrospinal fluid (CSF) leakage through a bony defect in the stapedial footplate. The inner ear was obliterated and contained small pieces of temporal fascia. A meningitis or CSF leakage due to inner ear malformation is extreamly rear condition for neurosurgeon. Though we always have to take it into condideration as a cause of CSF leakage.