Spontaneous encephalocele of the temporal bone.

Postsurgical and posttraumatic encephaloceles of the tegmen tympani and tegmen mastoideum are well-recognized occurrences. Less frequently recognized, however, is the spontaneous occurrence of an encephalocele associated with cerebrospinal fluid otorrhea or rhinorrhea. This cerebral herniation into the middle ear and the mastoid cavity in adults is associated with a loss of both bony and dural support, and surgical management must deal with both the cerebrospinal fluid leak and herniation of the brain.