Trigeminal Nerve: Neurodestructive Procedures

Abstract

The sphenopalatine (or pterygopalatine) ganglion (SPG) is mainly a parasympathetic ganglion in the upper part of the pterygopalatine fossa; its postsynaptic fibers supply the lacrimal, nasal, palatine, and pharyngeal glands. It is closely related to the maxillary nerve and lies just beneath the pterygopalatine (sphenopalatine) fossa (Fig. 11.1). The ganglion has a flat conical shape that can extend to a length of 5 mm. The fossa has a triangular shape with its basis at the floor of the sphenoid sinus with a length of approximately 2 and 1 cm width. On a lateral fluoroscopic view, the fossa resembles an “inverted vase” (Fig. 11.2). The fossa is bordered anteriorly by the posterior wall of the maxillary sinus, posteriorly by the pterygoid process and the ala major of the sphenoid bone, medially by the perpendicular plate of the palatine bone, and superiorly by the sphenoid sinus; laterally it communicates with the infratemporal fossa. The fossa is anteriorly connected to the orbit through the inferior orbital fissure, medially to the nasal cavity through the pterygo(spheno)palatine foramen, postero-superiorly to the middle skull “groove” through the foramen rotundum (which contains the maxillary nerve) and to the mouth through the palatine canal, and posteriorly to the nasopharynx. The fossa also contains the maxillary artery and its multiple branches.