Chronic Headaches and Migraines
The sphenopalatine ganglion (SPG) is a collection of nerve cells that is closely associated with the trigeminal nerve, which is the main nerve involved in headache disorders. It contains autonomic nerves and sensory nerves. Autonomic nerves are specialized nerves that control organ functions including gut and bladder movements, beating of the heart, sweating, salivation, tearing and other secretions. The SPG is located just behind the bony structures of the nose.
The SPG has connections to the brainstem (where cluster and migraine attacks may be generated) and to the meninges (coverings of the brain) by the trigeminal nerve. Inflammation and the opening of the blood vessels around the meninges occur which activate pain receptors that send pain impulses through the trigeminal nerve and eventually to the sensory area of the brain and are perceived as pain.
What is the role of the sphenopalatine ganglion in headache disorders? Inmigraine and cluster headache, nerves carrying these pain signals pass through the SPG, with some making connections to the autonomic nerves. This explains why in cluster headache, and sometimes in migraine, we see autonomic features including tearing of the eyes and nasalcongestion or discharge. We call this the trigeminal autonomic reflex.