Surgical treatment of brain herniation into the middle ear and mastoid.

A series of thirty-five patients operated on for brain herniation into the middle ear and mastoid is presented. The etiologic factor was felt to be previous surgery in twenty-six cases, head trauma in four cases, chronic otomastoiditis in four cases, congenital dehiscence of the tegmen in one case, and subdural empyema in one case. Diagnosis and treatment of brain herniation are discussed. The mastoid approach for repair of tegmen defects from below with the use of homologous cartilage or autologous cortical bone is advocated. A combined procedure using the transmastoid approach plus a mini-craniotomy of the temporalis squama is suggested as an alternative treatment to middle cranial fossa repair for larger cerebral hernias.