Female, 64 years old, with hearing loss and a lesion in the left auditory canal. Enhancement of the left facial nerve is seen beginning at the pre-meatal segment and continuing into the geniculate region with involvement of the labyrinthine, tympanic and mastoid segments of the nerve. In addition, the vestibule and semicircular canals on the left also appear to be enhancing to some degree (see key images).The geniculate region as well as the tympanic and mastoid segments of the facial nerve on the right also appear to enhance but to a milder degree than on the left. The vestibule and semicircular canals are questionably enhancing on the right as well.No masslike lesions are seen. No abnormalities of the prepontine or CP angle cisterns are demonstrated. Limited views of the remainder of the brain show scattered nonspecific T2 hyperintense lesions.
Enhancement of the facial nerves is seen as they traverse the temporal bones, left side more than right. There is also likely some degree of labyrinthine enhancement as well, again left greater than right. Given the bilateral nature of these findings, an underlying systemic process is favored, for example an infectious or postinfectious phenomenon, or perhaps an autoimmune or granulomatous process.