What Is A Sphenopalatine Ganglion Block?

The sphenopalatine ganglion is a collection of nerve fibers that is found inferior to the nose within the pterygopalatine fossa. The sphenopalatine ganglion is a parasympathetic ganglion that contains sympathetic, parasympathetic, and sensory roots. This collection of nerve fibers supplies the paranasal sinuses, lacrimal gland, mucosa glands of the pharynx and nasal cavity, the gingiva, and the glands and mucous membranes of the hard palate. A nerve fiber may be sensitized by infection, trauma, or other causes and that sympathetic response may cause pain. Blocking the sphenopalatine ganglion, by anesthetizing it, may eliminate this pain.

A sphenopalatine ganglion block is a non-surgical procedure that can be used to diagnose the source of head and face pain. Additionally, it can be used to manage certain types of headache pain, atypical facial pain, neuralgias, and other sympathetic pain conditions.

The sphenopalatine ganglion has been a target for the treatment of headache pain for over 100 years. When the treatment was first performed, cocaine or alcohol was used to block the nerve bundles of the sphenopalatine ganglion. This block interfered with pain signal transmission and helped to provide relief from nasal headache pain. Since its introduction back in the early 1900s, the sphenopalatine ganglion has become a main site of treatment for severe headache pain, migraine pain, and atypical facial pain. While alcohol and cocaine were the agents used initially to achieve the nerve block, lidocaine and other local anesthetics are now utilized for this procedure.

How Is A Sphenopalatine Ganglion Block Performed?

A sphenopalatine ganglion block is a minimally invasive procedure that is performed in an outpatient setting. Physicians have various methods that they can choose from to anesthetize the sphenopalatine ganglion, including the transnasal, transoral, and lateral approach. By anesthetizing the nerve bundles within the sphenopalatine ganglion, pain sensation transmission is essentially blocked, thereby helping to reduce pain. Patients may be sedated prior to the procedure depending on the approach that is used.

The most frequently used approach for performing a sphenopalatine ganglion block is the transnasal approach. This approach can be performed by either applying an anesthetic directly to the membranes within the nasal cavity or by inhaling the anesthetic.  When the physician chooses to apply the local anesthetic directly to the mucous membranes within the nasal cavity, the patient is usually positioned on their back with their nose pointed toward the ceiling. A local anesthetic is then applied using a cotton-tipped applicator directly to the lateral part of the nasal cavity just above the nerve bundle. The applicator remains in position for approximately 20 to 30 minutes to allow for greater absorption. After the procedure is completed, the patient is monitored for pain. The application is repeated until the patient has achieved adequate pain relief.

When the physician chooses to use inhalation of the anesthetic for the sphenopalatine ganglion block, the anesthetic is administered without the use of the applicator. For this procedure the patient is placed on their back with their nose pointed upward toward the ceiling. The physician inserts the anesthetic medication, usually a 2% viscous lidocaine solution, into the nasal passageway. Once the medication is inserted, the patient is instructed to quickly inhale.

The intraoral approach is another method that can be used to perform a sphenopalatine ganglion block. This method uses a very small dental needle. The physician palpates the patient’s gum line to locate the proper area for needle insertion. Once the correct location is identified, the needle is inserted and a local anesthetic is injected.

A sphenopalatine ganglion block is a relatively quick procedure that offers patients rapid pain relief. Patients usually report pain relief between 15 and 30 minutes after the procedure. Patients are monitored for adverse reactions after the procedure is finished.

The risks associated with a sphenopalatine ganglion block are very low. The most common side effect is the development of