Peristapedial bulb: an indicator of spontaneous CSF leak in cochlear candidates with Mondini dysplasia

Mondini dysplasia with spontaneous cerebrospinal fluid (CSF) leak is rare in cochlear implantation (CI) candidates but lethal. Detailed evaluation and surgical intervention are needed for these patients.To report our findings of the peristapedial bulb in computer tomography (CT) as diagnostic evidence of spontaneous CSF leak and discuss its clinical value to direct the surgical plan for patients with profound sensorineural hearing loss (SNHL) and meningitis.A retrospective review was conducted, including patients' demographic features, radiographic examination, operation records, auditory/speech evaluation. The patients presented with a peristapedial bulb were included.In 2775 CI recipients, 7 out of 219 (3.2%) patients with Mondini anomaly had detectable peristapedial bulbs in HRCT, among whom 6 patients have a history of meningitis. Surgical exploration verified the radiographic findings in 6 out of 7 patients. All patients received CI and vestibular obliteration. Control of meningitis was acceptable. The threshold of hearing significantly decreased from 74.1 dB ± 6.9 dB to 37.1 ± 4.8 dB after CI and the word recognition score elevated from 21.4 ± 14.9% to 78.6 ± 9.3%.Peristapedial bulb is an indicator of spontaneous CSF leak in patients with profound SHNL and Mondini anomaly. Patients will benefit from CI and surgical intervention.