Spontaneous middle ear meningoencephalic herniation. 2 case reports

Two cases of idiopathic brain herniation into the middle ear without previous surgery are reported. Brain herniation is an unusual pathology, usually related to middle ear surgery. The idiopathic appearance of this disease is the secondly most frequent cause. Its origin is believed to be related to a congenital defect of tegmen timpani. Two elements, both rare, are emphazised: the spontaneous bilateral presentation in one of the cases, and the CSF leak as an initial symptom. We present a review of the literature, describing epidemiology results and the main accepted etiology theories. We discuss the diagnosis and treatment methods: magnetic resonance imaging and surgery.