What is The Sphenopalatine Ganglion?

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. In the SPG, these autonomic nerves supply the lacrimal glands (which produces tears) and the inner lining of the nose and sinuses (which produces nasal discharge or congestion). The SPG is located just behind the bony structures of the nose.

What is The Role of The Sphenopalatine Ganglion in Headache Disorders?

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 opening of the blood vessels around the meninges occur, which activate pain receptors that send pain impulses through the trigeminal nerve, eventually to the sensory area of the brain, and are perceived as pain. In migraine 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 nasal congestion or discharge. We call this the trigeminal autonomic reflex.

What is a Sphenopalatine Ganglion Block?

A nerve block is a procedure to stop pain transmission through anesthesia to the nerve. In an SPG block, an anesthetic agent is administered to the collection of nerves in the ganglion. The least invasive way to access the SPG is through the nose. This is discussed in more detail in another article about SPG Block in headaches.

The risks of the procedure are typically minimal. They include discomfort during and after the procedure, a numb sensation when swallowing, bitter taste from the anesthesia, bleeding from the nose, and light-headedness. These side effects typically resolve within minutes to a few hours. There is a very small risk of seizures, infection, and allergic reactions.

SPG Blocks Have Been Reported to Treat the Following Conditions:

  • Cluster headache
  • Migraine
  • Trigeminal neuralgia
  • Herpes zoster
  • Paroxysmal hemicrania
  • Cancer of the head or neck
  • Facial pain that is atypical
  • Complex regional pain syndrome (CRPS)
  • Temporomandibular disorder
  • Nasal contact point headache
  • Vasomotor rhinitis

Recently, a device that administers laser therapy to the SPG has been developed to reduce pain for migraine and cluster headache patients. The device produces a nerve block through a laser that is emitted from a probe inserted into the nose. The treatment is relatively non-invasive and takes minutes to administer to each nostril. Larger studies will be forthcoming.

What is Sphenopalatine Ganglion Stimulation?

Recent studies have shown that SPG stimulation may be effective in chronic cluster headache and migraine. Further studies are ongoing, and results in larger number of patients should be out within the next few years.

This procedure typically requires implantation of the device through the mouth (under general anesthesia) with leads of the neurostimulator being positioned at the SPG. Recent studies have shown encouraging results. As with other oral and facial surgery, the procedure carries surgical risks—and numbness, pain and sensitivity in the face, gums, and teeth may be more common than in SPG blocks, though typically are temporary side effects.

© Yasmin Jion, MD, and Matthew S. Robbins, MD. All rights reserved.

Yasmin Jion, MD, Fellow in Headache and Facial Pain, Montefiore Headache Center, Albert Einstein College of Medicine

Matthew S. Robbins, MD, Associate Professor of Clinical Neurology, Albert Einstein College of Medicine, Chief of Service – Neurology, Weiler Division, Montefiore Medical Center, Director of Inpatient Services, Montefiore Headache Center

This article is a legacy contribution from the American Headache Society Committee for Headache Education (ACHE) and the Fred Sheftell, MD Education Center.

Last Updated 9/10/2018

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