A Case of Bilateral Idiopathic Temporal Cerebrospinal Fluid Leakage With Multiple Fistulas in the Middle and Posterior Cranial Fossae Closed Using the Transmastoid Approach.

Although idiopathic temporal cerebrospinal fluid (CSF) leaks are a relatively rare condition, its incidence has been increasing in the United States in recent years. Fistulas commonly occur in the middle cranial fossa (MCF), and the MCF approach is recommended for multiple or large fistulas. Here, we present a case of bilateral temporal CSF leaks and multiple fistulas. The patient had small fistulas in the middle and posterior cranial fossae, which were successfully treated using the transmastoid (TM) approach, and proper postoperative management of CSF pressure resulted in favorable outcomes. The TM approach is particularly advantageous for addressing fistulas located in the posterior cranial fossa. Furthermore, in cases with multiple fistulas, a high likelihood exists that underlying factors such as idiopathic CSF hypertension, obesity, and obstructive sleep apnea (OSA) may be contributing to the condition. Managing these underlying factors effectively can lead to favorable outcomes. Despite the lower prevalence of idiopathic temporal CSF leak cases in Japan compared to the United States, the incidence of this condition is expected to rise globally owing to the increasing rates of obesity and OSA.