Radiofrequency Rhizotomy (RFR) For Trigeminal Neuralgia
To understand trigeminal neuralgia and RFR treatment, it is helpful to know what the trigeminal nerve does. There are two such nerves. One is on the left side and one is on the right side of the face. Each nerve has two functions: motor and sensory. The sensory portion has three major divisions. See the picture on page 5.
- V1 transmits feeling from the forehead, eye, and crest of the nose to the brain.
- V2 transmits feeling from the rest of the nose, the cheek, upper jaw, teeth, gum, lip, and the hard palate.
- V3 transmits feeling from the lower jaw, teeth, gum, lip, tongue, temple, and ear canal. V3 also has motor nerves that control the muscles of chewing.
Finding which division is the source of your pain is a major part in planning your treatment. Sometimes, finding the correct division is complex. Having a trigger point can be a helpful clue. A trigger point is a very sensitive spot on your face or in your mouth. If touched by finger or tongue, it will often trigger a pain. Knowledge of a trigger point is helpful because it tells us which division is causing your pain. Of course, pain can also be caused by less precise actions such as chewing, talking, shaving, swallowing, brushing teeth, and wind or water on the face. These are known as provocative factors. These factors are of limited use in finding the site where your pain starts.
What is RFR and How May It Help You?
Radiofrequency Rhizotomy (RFR) is a treatment to relieve pain. It is most often done by a neurosurgeon in a hospital radiology suite. During the procedure, the neurosurgeon works with an anesthesiologist. This is because parts of the procedure require the patient asleep and other parts require the patient awake. For instance, while you are asleep, the neurosurgeon will insert a special needle, under x-ray guidance, through the skin of your cheek (see picture). Then, the needle goes though a natural opening in the skull base, called the foramen ovale (labeled FO in picture), and comes to lie where the three nerve divisions meet (labeled G in the picture).
The next step is to guide the needle tip to the division that is causing your pain. Your help is needed in finding this division. For this part you will need to be awake. As the neurosurgeon searches for this target he will pass a tiny electric current through the needle tip. In response, you will feel a tingling in a small area on your face. When you tell the surgeon that the tingle is right where your usual face pain is located, the target has been found.
Once this spot is found, you are put back to sleep with a short acting drug. While you are asleep, the surgeon passes a heating (radiofrequency) current through the needle tip. This destroys the nerve fibers that carry the painful messages. You are awakened again. Then, you are tested to see whether your pain site is slowly being replaced by numbness. This nerve fiber destruction is repeated until the surgeon is satisfied with the degree of facial numbness and the absence of pain.
Before the Procedure
Please stop all non-steroidal, anti-inflammatory medicines (such as naproxen, Advil®, or aspirin) and blood thinners (such as Coumadin®, Plavix®, or aspirin) at least a week before surgery.
Before your RFR you will see the neurosurgery nurse practitioner. She will complete a health history and physical exam. She will also answer questions that you might not have asked your doctor. That same day, you will have routine blood tests, an electrocardiogram, and a chest x-ray. The day before your RFR, a nurse from the hospital will call and tell you what time to report to the Care Initiation Unit on the 4th floor. Remember, after midnight you cannot eat or drink except a sip of water for your medicines. You should take your usual medicines (including Tegretol® or Dilantin®) with small sips of water on the morning of the RFR.
The Procedure
From the Care Initiation Unit you will be brought to the x-ray procedure room on the 3rd floor. Staff will help you onto the x-ray table. You will be lying on your back. Your arms and legs will be gently secured on the padded x-ray table. You will be given medicines through an IV during the times you need to be asleep. You will be given oxygen through nasal prongs to aid your breathing.
After the Procedure
You will recover in the Care Initiation Unit (4th Floor) for 2 to 4 hours. Most often, patients go home the same day. We are able to keep patients overnight if that is needed. When you are ready, you may have food and liquids as you wish. Take special care to protect the numb side of your face. (See the section on Care At Home). As soon as you are able to drink enough fluids, your IV will be removed.
If you have been taking medicines such as Dilantin® or Tegretol® your dosage will be decreased slowly over a few days. Your doctor will write out a schedule for decreasing the dosage. Your nurse will discuss this with you and answer any questions you might have. The dosage must be tapered slowly. Please do not stop taking your medicine all of a sudden.
Pain Relief and Complications
In cases of typical trigeminal neuralgia, 95% of patients have pain relief right away. Pain recurs in about 20% of patients in 6 years. The length of relief depends on the depth of the numbness. Recurrence can be treated again with medicines and later with repeat RFR as needed.
All procedures carry the risk of complications. In the case of RFR, unpleasant facial numbness is one. Although, some degree of facial numbness is needed for any pain relief, at rare times, patients may find that the numbness that they have after the RFR bothers them more than the original pain itself. Sometimes, the numbness may extend to the covering (cornea) of the eye. The corneal reflex will be absent. This leaves the patient at risk of injuring the eye surface without knowing it (see more below). The risk of other complications such as infection, bleeding, double vision, stroke or anesthesia dolorosa (a severe constant burning pain) is low, but not zero. The doctor will explain these risks and others to you in more detail before the RFR.
Care at Home
Because the feeling in your face is decreased or absent you may not be able to feel pain, heat, cold, or something touching your face. At first, this loss of feeling will seem strange. It may feel like part of your face is swollen, but your mirror will show you that the swelling is minor. You will slowly adjust to this loss of feeling.
You should take special safety measures to protect the numb side of your face. Check the temperatures of water and food with the other side of your face or mouth first. This is important since you will not be able to judge hot and cold on the numb side of your face. Chew on the opposite side of your jaw to avoid biting your numb cheek.
Check your lips often to wipe off food particles you may not be able to feel. Check your mouth after meals for sores or food particles caught in your teeth that may cause irritation or infection. Brush your teeth carefully after each meal. You should see your dentist for routine check-ups every six months. Since the numb side of your face will not be able to feel hot or cold, extreme weather conditions are a danger to you. You may have to guard against frostbite and sunburn.
Eye Care in the Case of Absent Corneal Reflex
The doctor may tell you that the corneal reflex in your eye is absent. This was mentioned under “complications” above. Normally, this reflex makes you blink and tear when the eye is irritated. Since you cannot feel eye irritation, you will need to check your eye for redness and swelling on the surface of your eyeball several times a day. Your doctor may order eye drops to keep your eye moist. A nurse will show you how to use the eye drops before you leave the hospital. Sometimes, feeling returns in the eye. If this happens, you will be able to feel the eye drops going onto your eye. You may stop using the drops if feeling returns to your eye.
Follow-Up Care
Your doctor wants you to return for a check-up visit. It will be set up for you before you leave the hospital.
When to Call the Clinic
Call if you have:
- Increasing headache not relieved by Tylenol®.
- New onset confusion, stiff neck, or fever above 100.5°F.
- Increased swelling, redness, and pain in the cheek or needle entry site.
These could be signs of infection or internal bleeding.
Phone Numbers
During the first three days after surgery, call the neurosurgery nurse practitioner at
(608) 263-1410
At night, call the emergency room at (608) 262-2398.
If you live out of the area, call toll-free at 1-800-323-8942.
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The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Any duplication or distribution of the information contained herein is strictly prohibited.
Last Updated: 12/07/2011
Copyright © 12/07/2011 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. UWH #6035
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