Sphenopalatine ganglion (SPG) is a group of nerve cells that is linked to the trigeminal nerve, the main nerve involved in headache. The SPG, located behind the nose, carries information about sensation, including pain, and also plays a role in automatic functions, such as nasal congestion, acute and cluster headaches, migraines, trigeminal neuralgia, facial pain and more due to such a wide reach that the nerves from SPG expand to.
The link between the SPG and the trigeminal nerve is important in head pain. It has been shown that if you apply local anesthetics (or numbing medications) such as lidocaine to block or partially block the SPG, this can be helpful in reducing head and facial pain.
SPG Block procedure consists of laying down at a 45-degree angle, keeping head very still for 25 min. Laying down at this angle will help the medication extend to the back of the nasal cavity and place the anesthetic liquid right where it should be applied. It has a small flexible tip designed to help reduce irritation to the nasal lining. In the nasal cavity, the anesthetic liquid is sprayed directly onto the group of SPG nerves. The nasal applicator has a plastic delivery tube that is soft and flexible so that it can comfortably administered.
During the procedure you may feel mild pressure, or feel like you have to sneeze, or a brief mild discomfort or irritation like "something is in my nose." You may also experience a brief or quick burning sensation or have a bad taste in your mouth as some of the numbing medication may be swallowed.
The most common side effects are all temporary, including numbness in the throat, low blood pressure, dizziness and nausea. If you do experience throat numbness, this should not last more than a few hours and is related to swallowing a small amount of the numbing medication.
SPG block can be repeated as often as needed to reduce pain. Most often patients receive their initial procedure then have an additional procedure within 7 to 14 days then repeat again in 14 to 30 days and continue with extending the time. Typically patients will be able to spread out the procedure for several months before they need additional treatments.