Sphenopalatine Ganglion (SPG) Blocks

The Sphenopalatine Ganglion (SPG) is a group of nerve cells located behind the nose that is linked to the trigeminal nerve, the main nerve involved in headache. It carries information about sensation, including pain, and also plays a role in autonomic functions, such as tearing and nasal congestion.

The link between the SPG and the trigeminal nerve is important in head pain. Local anesthetics (or numbing medications) to block or partially block the SPG, can be helpful in reducing head and facial pain. SPG blocks are now used to treat pain of trigeminal neuralgia, persistent idiopathic facial pain, acute migraine, acute and chronic cluster headaches, Herpes Zoster neuralgia involving the ophthalmic nerve, and various facial neuralgias.

SPG blocks were first described in the 1900’s using a technique involving the application of numbing medication onto 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 on the cheek. This process is invasive, and usually requires the use of an x-ray machine to place the injection correctly.

In the last few years, three devices (Sphenocath®, Allevio® and Tx360®) have been FDA approved for performing SPG blocks. The procedure involves placing a very thin plastic tube called catheters into the nose to insert numbing medication in and around the SPG. The catheter is attached to a syringe that contains numbing medication. The numbing medication is delivered to the SPG to help treat headache and facial pain. 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.

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. 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 temperature may be checked. Your provider may numb the nose by having you inhale or applying a local numbing medication to help make you more comfortable when the catheter is placed. 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 and in total takes between 10-20 seconds to complete. 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.

After the procedure is completed you may be asked to lie down for about 15 minutes and your blood pressure may be checked. 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 is rare but 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 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).

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.

You can watch a video of the procedure at :