The 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 autonomic functions, such as tearing and nasal congestion. To read more about the SPG and its role in headache, please see these articles:
1. The Sphenopalatine Ganglion (SPG) and Headache Disorders, Part I
2. The Sphenopalatine Ganglion (SPG) and Headache Disorders, Part II
The link between the SPG and the trigeminal nerve is important in head pain. If you apply local anesthetics (or numbing medications) to block or partially block the SPG, this can be helpful in reducing head and facial pain.
SPG blocks were first described in the 1900’s using a technique involving the application of numbing medication on to cotton swabs then placed into the back of the nose. Another technique used to block the SPG involves using a needle to inject the SPG through an area in the cheek. This process is invasive, and usually requires the use of an x-ray machine to correctly place the injection.
In the last few years, three devices have been FDA approved for performing SPG blocks. These devices involve placing a very thin plastic tube into the nose to insert numbing medication in and around the SPG. These devices, called catheters, may be more effective in reducing head and facial pain than the technique using cotton swabs, and are less invasive than the injection technique. Below we will review the three devices, Sphenocath®, Allevio®, and Tx360®, and what to expect with the procedure.
All three devices are considered catheters, or small thin plastic tubes that are inserted into the body. There are no needles involved, and they are quick, safe, and easy to use. Both the Sphenocath® and Allevio® are similar in that they are thin flexible catheters about 5 centimeters in length and have a very small diameter. These 2 catheters have an angled tip to assist with anesthetic placement. The catheter of the Tx360® is smaller than the other two but the length is similar. All three catheters are attached to a syringe that contains numbing medication. The medication is pushed through the syringe once the catheter is placed into the correct position, and delivers numbing medication to the SPG to help treat headache and facial pain. The Sphenocath® procedure may be done with or without an x-ray machine to help guide the catheter into correct positioning.
How is the procedure done and what should I expect during the procedure?
The day of the procedure you should be able to travel to the office and drive home afterwards. However, certain programs may require that you have someone to drive you home. No sedating medications are needed for the procedure. The procedure is often done in an exam room by your provider. If needed, a decongestant prior to the procedure may be used to help reduce irritation in the nose.
Prior to the procedure, your blood pressure and heart rate, and possibly your cheek temperature may be checked. This depends on your provider’s preference. Your provider may numb the nose by having you inhale or applying a local numbing medication. This is done to help make you more comfortable when the catheter is placed.
After your provider has allowed time for the nose to numb, if your provider is using the Sphenocath® or the Allevio® device, you will be asked to lie down on your back with your head extended. The Sphenocath® or Allevio® device will be gently placed into one nostril and the catheter will be advanced. The numbing medication will be pushed through the syringe, and then the catheter will be taken out. The procedure will be repeated in the other nostril. The procedure takes between 10-20 seconds to complete. After the procedure is completed you may be asked to lie down for about 15 minutes and your blood pressure may be checked.
If the Tx360® device is used, you will remain seated during the procedure. The device will be placed into one nostril and the catheter will be advanced. The numbing medication will be pushed through the syringe, and then the catheter will be taken out. This will be repeated in the other nostril. The procedure takes between 10-20 seconds and you can leave after the procedure is completed.
No matter the device used, 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. Sucking on a piece of candy during the procedure can help and is recommended by the company that produces the Tx360® device.
Tearing and a brief temperature change are likely to occur and may indicate the procedure was successful. You may experience an immediate reduction in head and/or facial pain, but results can take anywhere from 15 minutes to a few hours to occur.
Potential Side Effects
The most common side effects are all temporary, including numbness in the throat, low blood pressure, 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. During this time it is safest if you avoid eating or drinking anything to avoid the risk of choking. Nasal bleeding or infection has been reported in some cases. Rarely, a temporary increase in pain has been reported.
How often can I have this procedure done?
SPG block can be repeated as often as needed to reduce pain. One study on the Tx360® device reports reduced frequency and severity of chronic migraine pain over a six month period if the procedure was done twice a week for six weeks (a total of 12 procedures)1.
Will insurance cover this procedure?
Most insurance carries cover SPG block for a variety of headache disorders, but you should speak with your insurance representative to ensure it is covered if your provider performs it.
SPG block, using one of these three catheters, is a safe, quick, and effective way to reduce severity and frequency of various headache disorders for a period of time. Like many other procedures in headache medicine, SPG block is likely to work best when combined with a comprehensive headache treatment plan.
Larry Charleston IV, MD, FAHS
Department of Neurology
University of Michigan
Ann Arbor, MI
Rashmi Halker MD FAHS
Assistant Professor of Neurology
Jessica Ailani MD FAHS
Associate Professor of Neurology
Director, Georgetown Headache Center
Medstar Georgetown University Hospital
© 2015, All rights reserved
1. Cady R, Saper J, Dexter K, et al. A double-blind, placebo-controlled study of repetitive transnasal sphenopalatine ganglion blockade with Tx360® as acute treatment for chronic migraine. Headache 2015, 55:101-116