Identification of Cerebrospinal Fluid Leakage by Cisternography in Recurrent Meningitis Associated With Inner Ear Malformation.

Cerebrospinal fluid (CSF) leakage is a recognized cause of recurrent meningitis, and accurate identification of the CSF leakage site is essential for definitive surgical management. We report an adult case of recurrent meningitis associated with bilateral congenital inner ear malformations. The combined use of radionuclide cisternography and computed tomography (CT) cisternography successfully localized CSF leakage to the right inner ear, and surgical obliteration of the right inner ear prevented further recurrence of meningitis. A 46-year-old man experienced repeated episodes of bacterial meningitis accompanied by right-sided acute otitis media. He had experienced severe bilateral hearing loss since childhood and a prior episode of left-sided acute otitis media 11 months earlier. CT of the temporal bone revealed bilateral incomplete partition type I inner ear malformations. Radionuclide cisternography and CT cisternography using ¹¹¹In- diethylenetriaminepentaacetic acid demonstrated abnormal tracer accumulation in the right mastoid and contrast leakage into the inner ear, confirming CSF leakage at this site. Right inner ear obliteration was performed, and intraoperative findings revealed CSF leakage at the stapes footplate. The patient has remained free of meningitis recurrence. This case underscores the diagnostic utility of combining radionuclide cisternography and CT cisternography for precise preoperative localization of CSF leakage in patients with congenital inner ear malformations.