Anatomic Landmarks of the Glossopharyngeal Nerve: A Microsurgical Anatomic Study

Abstract

Two landmarks help to identify the GPhN in the subarachnoid space: the choroid plexus of the lateral recess of the fourth ventricle and the dural entrance porus of the jugular foramen. The opening of the cochlear aqueduct, the mastoid canaliculus, and the inferior tympanic canaliculus are three landmarks of the GPhN within the jugular foramen. Finally, the base of the styloid process, the base of the styloid pyramid, and the transverse process of the atlas serve as three landmarks of the GPhN at the extracranial region in the infratemporal fossa.

Upper cervical chiropractic care for a 25-year-old woman with myoclonic seizures

“…The first involves displacement of the C1 vertebrae, placing pressure or torsion on the carotid sheath containing the common carotid artery; internal carotid artery; internal jugular vein; and glossopharyngeal, vagus, and spinal accessory nerves. 13,14 A second theory arises from torsion or pressure upon the superior cervical ganglion located at the vertebral body of the axis and posterior to the carotid sheath. 15 Vagal nerve stimulation, which is reported as an acceptable treatment of epilepsy, has been shown to reduce seizure frequency, even in pharmacoresistant generalized epilepsies.…”

Detailed MR Imaging Anatomy of the Cisternal Segments of the Glossopharyngeal, Vagus, and Spinal Accessory Nerves in the Posterior Fossa: The Use of 3D Balanced Fast-Field Echo MR Imaging

“…1,2,8 Although the glossopharyngeal nerve is located within the anterior part, the vagus and accessory nerves are located within the posterior part. Sometimes, there is a complete division of the foramen by a bony septum; partitions of the foramen vary in radiologic and anatomic studies.…”

“…2,8 By using a different angle and different length for each CSF recess adjacent to the JF to the posterior petrous bone, we could easily differentiate each CSF recess. The cochlear aqueduct is a bony canal that encloses the perilymphatic duct connecting the subarachnoid space and the basal turn of the cochlea.…”

“…1 During microsurgery, the cochlear aqueduct provides a landmark on the subarachnoid side of the glossopharyngeal nerve in the JF. 8,15 However, because of the close proximity, the re- cess for the cochlear aqueduct and the recess for the glossopharyngeal nerve can be mistaken for each other as seen on axial images, especially with the use of thicker sections. 1,2 Our results showed that the recess for the cochlear aqueduct has the most acute angle in relation to the posterior petrosal surface, consistently being Ͻ50°.…”

“…5 Unlike the facial nerve or vestibulocochlear nerves, the course of the lower CNs through the JF has not been well elucidated in vivo. 2,8 Sometimes, the JF and adjacent cochlear aqueduct cannot be easily identified on axial plane images. 1 Regarding visualization of the CNs, especially within the cisternal spaces, a 3D constructive interference in steady state sequence, a 3D driven equilibrium sequence, a 3D fast imaging employing steady-state acquisition (FIESTA) sequence, and a gadolinium-enhanced 3D FIESTA sequence have been used successfully to demonstrate the presence of CNs within the cisternal spaces.…”