Overview of Sphenopalatine Ganglion Radiofrequency Thermocoagulation
Sphenopalatine ganglion neuralgia is a complicated condition that can cause chronic pain in the head and neck areas. It can often be linked with automatic body functions too. The symptoms can vary greatly from person to person. However, the most common symptom is experiencing a dull headache combined with pain in the upper jaw and teeth. Some patients might also sweat profusely and notice changes in their body’s usual control systems (vasomotor changes) when the pain intensifies.
People have used numerous methods to target the sphenopalatine ganglion (a collection of nerve cells linked with the trigeminal nerve, the primary nerve involved in our face’s sensation) to alleviate symptoms of various conditions. These can include muscle related pain, a specific kind of neuralgia (nerve pain) after shingles, post-traumatic headaches, cluster headaches, and jaw joint pain, and even pain related to head and neck cancer.
The sphenopalatine ganglion block, a method to numb the sphenopalatine ganglion, was first used in 1908 by a doctor named Sluder. He used a 20% cocaine solution inserted through the nasal passages. Later, in the 1970s and 1980s, other doctors studied and confirmed its benefits to manage headaches, facial neuralgia, lower back pain, and jaw joint pain. Nowadays, people use this method most commonly for cluster headaches, a severe form of facial nerve pain called trigeminal neuralgia, migraines, and other unusual facial pains.
Another effective way to treat chronic pain is Radiofrequency thermocoagulation, also known as radiofrequency neurotomy. In this procedure, doctors use thermal energy (heat) to eliminate the specific nerves involved in painful stimuli’s pathological transmission. This is done using a device that generates high-frequency electromagnetic radiation to create heat. The heat leads to local tissue damage and loss of myelinated nerve fibers, which are nerve fibers covered by a protective sheath. When the needle tip heats up to 80 °C (176 °F) for 1-1.5 minutes, it consistently destroys an 8-10 mm area.
There’s another similar method, called Pulsed Radiofrequency Ablation. In this technique, doctors use short 20 ms pulses every 0.5 seconds. This method lets the tissue cool between pulses, so the target temperature does not exceed 42 °C (107.6 °F). Although this method results in less tissue destruction and less pain, the relief is typically shorter. That’s why you might need more frequent repeat treatments, making it potentially more expensive.
Anatomy and Physiology of Sphenopalatine Ganglion Radiofrequency Thermocoagulation
The sphenopalatine ganglion (SPG) is a cone-shaped structure and one of the largest nerve bundles in our skull. It is also known by other names like the pterygopalatine ganglion or nasal ganglion. It is found in the central part of the pterygopalatine fossa, a space inside the skull. It helps in receiving and sending nerve signals to various parts of our face like the nose, lips, mouth, and eyes through the greater and lesser palatine nerves. It plays a significant role in receiving inputs of various sensations.
The SPG receives inputs mainly from three types of nerve fibers:
1. Sympathetic fibers: Nerve fibers from the superior cervical ganglion (a nerve bundle in the neck) reach the SPG. These fibers control the wetness or dryness of the mucosa, the moist tissue lining certain parts of the body such as the nose and throat.
2. Parasympathetic fibers: These nerve fibers originate from the superior salivatory nucleus (part of the facial nerve) and reach the SPG. These fibers help in the secretion of fluids from nose, soft palate, uvula, tonsils, the roof of the mouth, gums, upper lips, throat, tear glands, and blood vessels in the brain.
3. Sensory fibers: These fibers start from the maxillary nerve, which provides sensation to the mid-face and upper jaw areas. The majority of outgoing fibers pass directly through the SPG and exit via the greater and lesser palatine nerves without forming links. These nerves help in the sensation of pain to different parts of the face.
The SPG is critically important in some types of headache disorders, in particular, cluster headaches, which are intense, one-sided headaches usually accompanied by other symptoms such as excessive tearing or a runny nose. The SPG can cause an increase in blood flow to the brain, leading to the release of certain substances that can activate pain receptors in the brain and cause headaches.
Why do People Need Sphenopalatine Ganglion Radiofrequency Thermocoagulation
There are five main types of severe headaches and nerve-related facial pains that may require special treatment or care:
1. Cluster headache: This is a type of excruciating headache that occurs in repetitive episodes or ‘clusters’, often at the same time of the day and night. They happen on one side of the head are usually associated with watery eyes, runny nose, or droopy eyelid on the same side as the pain.
2. Chronic migraine: This is a type of migraine that occurs 15 or more days a month, for at least three months. These headaches are often intense and accompanied by symptoms like light and sound sensitivity, as well as nausea or vomiting.
3. Other TACs: This short for Trigeminal Autonomic Cephalalgias, a group of severe, recurring headaches that are often felt on one side of the face around the eye area. This group includes rarer types of headaches like paroxysmal hemicranias, hemicrania continua (continuous headaches), and short-lasting unilateral neuralgiform headache attacks (SUNCT). SUNCT with cranial autonomic symptoms (SUNA) is a similar condition, but with added symptoms like watery eyes or a stuffy nose.
4. Trigeminal neuralgia: This is a severe facial pain that feels like an electrical shock, often triggered by everyday activities, like eating or talking. It’s connected to the trigeminal nerve, which controls sensation in your face.
5. Intractable orofacial pain syndromes: These are chronic, lasting facial pains in the mouth and face areas that are hard to control or treat. The word ‘intractable’ in this case means the pain hasn’t responded to usual treatments.
Each of these conditions require different treatments and approaches, so if you experience any of the symptoms mentioned, it’s important to consult with a healthcare professional for appropriate care.
When a Person Should Avoid Sphenopalatine Ganglion Radiofrequency Thermocoagulation
There are certain conditions where a patient might not be able to have an SPG radiofrequency ablation (RFA), a medical procedure where radio waves are used to reduce pain in the head or face. These conditions include:
If a patient has an infection that can’t be controlled in a specific part of the body or throughout the whole body, the procedure might not be safe. If a patient has a blood disease called coagulopathy, which makes it hard for blood to clot and stop bleeding, the procedure could also be too dangerous.
In some cases, if a patient has not responded to an SPG block (another type of treatment for pain) or chemical ablation, which is using chemicals to reduce pain, then SPG radiofrequency ablation might not work. Also, if a patient is hemodynamically unstable, which means their heart and blood vessels are not working together properly, the procedure might not be safe.
If a patient had major changes in the physical structure of a certain part of their body because of an injury or surgery, the doctor might need to avoid doing the procedure.
Before the procedure, the doctor should carefully check the heart of patients who have a pacemaker or defibrillator, which are devices that help control heart rhythm. These patients should be monitored closely after the procedure to ensure their heart is functioning properly.
Equipment used for Sphenopalatine Ganglion Radiofrequency Thermocoagulation
Here is a list of what’s needed for a specific medical procedure known as radiofrequency ablation:
1. The radiofrequency ablation system: This is a medical device used to destroy abnormal cells using heat generated by radio waves.
2. A Fluoroscopic C-arm: This is a type of special X-ray equipment that allows doctors to see real-time images of the inside of your body.
3. A 10 cm, 22 gauge radiofrequency ablation needle with a 5 mm active area: This is a special kind of needle used in the procedure to apply heat to the targeted cells.
4. Contrast agent: This is a type of dye used during some medical imaging tests to help doctors to see the images more clearly.
5. Lidocaine 1%: This is a common local anesthetic, a medication that causes loss of sensation in a small area for a short amount of time.
6. Bupivacaine 0.5%: This is another type of local anesthetic, commonly used before and after surgical procedures to numb the area and manage pain.
7. Triamcinolone: This is a type of corticosteroid medication, commonly used to reduce inflammation and alleviate symptomatic pain.
Who is needed to perform Sphenopalatine Ganglion Radiofrequency Thermocoagulation?
The treatment procedure with SPG RFA (a medical technique involving heat generation from an electric current to reduce pain), is usually performed by very skilled doctors who have received special training. Such doctors have learned how to use a special tool called a fluoroscope to accurately place needles inside your body. These doctors come from different fields such as pain medicine, anesthesiology (pain relief and managing vital functions), physical medicine and rehabilitation, neurology (brain, nerves and spine), emergency medicine, family medicine, or psychiatry (mental health).
These professionals aren’t working alone during the procedure; they have a team to ensure that everything goes well. This team includes a radiology technician who helps with imaging devices, a nurse to help with preparing and managing medical equipment, someone who provides anesthesia (medicine to put you to sleep or numb an area), and other staff members who provides patient support and care throughout the procedure.
Preparing for Sphenopalatine Ganglion Radiofrequency Thermocoagulation
Before a medical procedure, patients are usually given detailed information during a separate appointment. This would include an explanation of the steps involved in the procedure, the benefits, any risks or possible complications, as well as any alternatives. For some procedures, patients may be asked to stop taking blood-thinning medication for a certain amount of time. In more complicated cases, they may be advised to visit their family doctor to switch to a different type of blood-thinner for a while.
If patients have heart disease, they might need to be checked out before the procedure. They would be told not eat anything for 6 to 8 hours before this check up. If they have diabetes, they might need to change their doses of insulin or diabetes pills. Before the procedure, a medication review would be performed to keep track of any current prescriptions, and any known allergies. After the procedure, patients are typically advised to not drive or operate machinery for at least a day.
Before the procedure, a detailed discussion happens between the patient and the doctor. A document is signed, which both parties agree on. This includes the patient’s name, medical record number, age, and preferred gender. A mark is made on the site where the procedure will happen. A medical technician makes sure that the medical equipment is working properly before the procedure. A quick pause is done when the patient is on the table and all the medical personnel are present, to make sure everyone agrees they have the right patient and the right procedure in the right location. Proper steps are taken to stay clean and use sterile medical equipment as part of standard procedure.
How is Sphenopalatine Ganglion Radiofrequency Thermocoagulation performed
The Sphenopalatine Ganglion (SPG) is a group of nerve cells that can be reached through different paths inside your head; namely from inside your nose, under your cheekbone (infrazygomatic approach), and above your cheekbone (supra-zygomatic approach). However, radiofrequency treatments, a type of procedure that uses heat to reduce pain, are usually done using the under the cheekbone approach.
Fluoroscopic Approach: This is a technique where a patient is made to lie down supine (face upwards), and a special X-ray machine called a fluoroscope is used to obtain an image. The idea is to align the image in a way that makes a certain area of the head appear like an “inverted vase”. A local anesthetic (1% lidocaine solution) is applied to the skin entry point, which is located in front of the jaw bone and below the cheekbone. A special radiofrequency treatment needle is then inserted at this point and cleverly navigated towards the SPG, under constant fluoroscopic guidance. The needle direction needs to be constantly adjusted to get it to the right place without causing damage to surrounding structures. Once the needle is properly placed, some tests are performed to make sure everything is okay, and then a small amount of anesthetic is injected before applying the radiofrequency treatment. This treatment is quite painful, so it’s crucial to apply more pain relief after the operation to prevent future nerve pain.
CBCT Approach: A different technique uses Cone-Beam Computed Tomography (CBCT), a type of 3D imaging, to guide needle placement. Apart from the imaging method, most of the procedure is similar to the fluoroscopic approach. An interventional radiologist will confirm the position of the needle after it “walks off” a particular bony structure in the face. The benefits of using CBCT are that it can give a better visualization of the anatomy which can lead to more accurate placement, it is less costly than other imaging methods, and it exposes the patient to less radiation.
Possible Complications of Sphenopalatine Ganglion Radiofrequency Thermocoagulation
Procedures involving Sphenopalatine Ganglion Radiofrequency Ablation (SPG RFA) – a type of treatment often used for certain types of headaches and facial pain – can sometimes lead to complications. These issues mostly relate to inserting the needle used in the treatment and could involve infection, bleeding from the nose (epistaxis), internal bleeding, injury to the main artery in your cheek or nerve in your face, or sudden changes in your blood pressure and heart rate.
Uncommonly, you might experience numbness, strange sensations, or reduced sensitivity in your upper teeth, the roof of your mouth, or your throat. You might also notice less tear production in your eyes or reduced snot in your nose. Since SPG RFA can often slow down your heart rate, it’s important to keep a careful watch on your vital signs like heart rate and blood pressure during the procedure.
During the process, if you feel a wet sensation at the back of your throat, the doctor will slightly pull back the needle and recheck. If everything looks okay, they will inject a local anesthetic to numb the area. If you don’t feel the liquid sensation, the doctor will proceed with the treatment and watch carefully afterwards for any signs of complications like bleeding or infection.
What Else Should I Know About Sphenopalatine Ganglion Radiofrequency Thermocoagulation?
The Sphenopalatine ganglion RFA is a quick, cost-friendly, and secure procedure to treat chronic cluster headaches. This procedure doesn’t usually come with complications. Research conducted by Salgado-Lopez and his team from Spain demonstrate this. They tracked the progress of 37 patients who had undergone this procedure for around 68.1 months. Among these patients, around 13.5% experienced complete relief from pain and related symptoms, while about 56.8% had some level of relief. However, around 29.7% of the patients did not see any improvements. No complications were reported during this study.
Currently, there is a research study being done in China to further test the safety and effectiveness of the Sphenopalatine ganglion RFA treatment for cluster headaches. This study is following 80 patients over three years and comparing this treatment method with the traditional Sphenopalatine ganglion nerve blocking. The goal is to establish whether the Sphenopalatine ganglion RFA treatment is a safer, more efficient, and less invasive option for those suffering from cluster headaches and who haven’t benefited from regular medical treatments.
