Brain herniation and space‐occupying lesions eroding the tegmen tympani

Abstract

Technological advances in neuroradiology and the development of skull base surgery in neurotology have improved diagnosis and management of lesions eroding the tegmen tympani. The diagnosis of brain hernia is to be suspected in patients with a history of complicated chronic ear surgery and a slowly developing pulsatile mass with CSF leak. Patients are best evaluated in the upright position, with an otomicroscope and by magnetic resonance imaging (MRI). Over 6 years, our group has treated seven patients with eight space-occupying lesions eroding the tegmen. Five of the lesions were repaired with a temporalis muscle flap, 2 with fascia and bone, and 1 with Marlex. A review of new technology in the diagnosis of brain hernia and a modification of previous techniques is given.

A Clinicopathological Study of 15 Patients With Neuroglial Heterotopias and Encephaloceles of the Middle Ear and Mastoid Region

“…Other authors have reported cerebrospinal fluid otorrhea and symptoms of a mass lesion as the most common presenting symptoms. 16,18 Chronic infection or inflammation, previous trauma, or surgical procedures have been described in the literature as predisposing factors for the development of middle ear heterotopia or encephalocele, 10,13,14,16–20 and similar factors were identified in most of our cases. The aggregate of these findings lends support to the concept that middle ear region neuroglial masses are most often acquired encephaloceles.…”

“… 10–15 In the middle ear and mastoid region, most previously reported cases describe an association with previous trauma, surgery, or infectious or inflammatory processes. 10,13,14,16–20 However, patients with no significant predisposing factors or obvious relation to CNS structures have also been described, 1,11,15,21–24 leaving the pathogenesis unresolved. We evaluated the clinicopathological features of neuroglial heterotopias and encephaloceles involving the middle ear region to assist in the clarification of these issues.…”

Brain Herniation into the Mastoid in a Normal Hearing Ear

“…If endaural brain hernia is suspected, highresolution CT of the temporal bone, including coronal sections, is essential. Magnetic resonance imaging is use ful for further soft tissue analysis if implications in treat ment planning are expected [15,17,18],…”

CT scanning of middle ear cholesteatoma: what does the surgeon want to know?

“…MRI can confirm suspicion of defects in the tegmen tympani or dural plate on CT, and is of especial value in diagnosing cerebral herniation [8,9]. It can exclude dual pathology in patients presenting with facial nerve palsy or sudden sensorineural hearing loss, associated with cholesteatoma.…”