Geniculate Ganglion Anatomy for the Otologist

THE greater (superficial) petrosal nerve and the geniculate ganglion are major anatomic landmarks in the surgical approach to the internal auditory canal through the middle cranial fossa.¹The dura is elevated from the superior surface of the temporal bone through a craniectomy just above the root of the zygomatic process. The middle meningeal artery may be divided at the foramen spinosum to facilitate reflection of the dura. The greater petrosal nerve is then exposed a few millimeters posterior to the foramen spinosum. This part of the operation is similar to that used by neurosurgeons in their approach through the middle fossa to the gasserian ganglion in operative procedures for relief of trigeminal neuralgia. The otologist needs to remove a portion of the petrous bone over the internal auditory canal, and to locate this area he follows the greater petrosal nerve to the geniculate ganglion. The geniculate ganglion and proximal