Neuroanatomy, Pterygopalatine Ganglion

Excerpt

The pterygopalatine ganglion (PPG) is one of four parasympathetic ganglia located within the head region, existing as a bilateral pair. The pterygopalatine ganglion may also be referred to as the sphenopalatine ganglion, Meckel's ganglion, or the nasal ganglion. The pterygopalatine ganglion is responsible for housing the post-ganglionic parasympathetic neuronal cell bodies, in addition to acting as a conduit for post-ganglionic sympathetic and sensory axonal fibers. The fibers that arise from the pterygopalatine ganglion regulate secretomotor functions to and provide sensation from various structures that include: the lacrimal glands, the mucous membranes of the oropharynx, nasopharynx, nasal cavity, and upper portion of the oral cavity. The fibers from the pterygopalatine ganglion are also responsible for providing innervation to the cerebral and meningeal blood vessels. The pterygopalatine ganglion is a structure that is morphologically formed during the third trimester of fetal life, with its neurons derived from Schwann cell precursors. A group of headache disorders referred to as trigeminal autonomic cephalalgias (TACs), which include cluster headaches, are thought to be influenced by the pterygopalatine ganglion. There is strong evidence to support the usage of pterygopalatine ganglion blockade, radiofrequency ablation, or neurostimulation of the pterygopalatine ganglion to relieve cluster headaches. The utilization of pterygopalatine ganglion blockade for the treatment of migraines, trigeminal neuralgia, and other conditions has also demonstrated varying degrees of success.