The sphenopalatine ganglion (SPG) is a collection of nerve cells deep in the face behind the nasal passages. It is closely associated with the trigeminal nerve, the main nerve involved in headache disorders. A sphenopalatine ganglion block is an injection that is used both to diagnose and as a pain management technique in treating acute or chronic migraine and cluster headaches, and many types of facial pain.

Related: Sphenopalatine Ganglion Block