Anatomy and Pathology of the Facial Nerve

CN VII is a mixed cranial nerve with a complex anatomic course that consists of intraaxial, cisternal, canalicular, labyrinthine, tympanic, mastoid, and extracranial segments. Clinical patterns of facial palsy and associated symptoms help to localize lesions as supranuclear, nuclear, or infranuclear. CT and MRI have complementary roles in imaging evaluation, depending on the segment or segments of interest. Causes of disease include congenital, inflammatory, infectious, demyelinating, neoplastic, cholesteatoma, vascular, traumatic, and iatrogenic. Knowledge of the normal anatomy, embryology, and spectrum of pathology will aid radiologists in correctly diagnosing lesions of the facial nerve. © American Roentgen Ray Society.