Multiple temporal bone encephaloceles associated with tegmen tympani defects and idiopathic intracranial hypertension: An exceptional presentation of spontaneous lateral skull base cerebrospinal fluid leak

Abstract

ABSTRACT: Temporal bone encephaloceles associated with tegmen tympani defects represent a rare but increasingly recognized cause of spontaneous cerebrospinal fluid (CSF) leakage and lateral skull base pathology, frequently associated with idiopathic intracranial hypertension (IIH). Chronic elevation of intracranial pressure may lead to progressive osseous erosion of the tegmen tympani and tegmen mastoideum, resulting in herniation of meningeal and temporal lobe tissue into the middle ear and mastoid cavity. We report the case of a 65-year-old morbidly obese woman presenting with unilateral conductive hearing loss, pulsatile tinnitus, middle ear effusion, CSF rhinorrhea, headaches, and visual disturbances. Imaging investigations demonstrated multiple temporal bone encephaloceles associated with tegmen tympani defects, mastoid CSF accumulation, and transverse–sigmoid venous sinus stenosis, consistent with underlying IIH. The patient underwent successful surgical repair through a middle cranial fossa approach with multilayer reconstruction using collagen matrix, temporalis fascia, muscle grafts, pericranium, and hydroxyapatite bone cement. Owing to persistent intracranial hypertension, endovascular venous sinus stenting was subsequently performed, resulting in normalization of intracranial pressure and marked clinical improvement. This case highlights the pivotal role of multimodal imaging in accurately characterizing tegmen defects and temporal encephaloceles, identifying associated radiological stigmata of intracranial hypertension, guiding surgical planning, and optimizing multidisciplinary therapeutic management to reduce recurrence risk and improve long-term outcomes.