The purpose of these injections is to relieve the pain caused by the irritation of your pudendal nerve. The nerve is deep in your buttocks and sometimes may rub against a ligament or be squeezed between two ligaments. Sometimes inflammation around the nerve will compress the nerve and cause pain. There can be other nerve problems in addition to the pain. There could be bladder problems (irritability, difficulty starting or emptying). There can be sexual problems in both sexes (pain, dryness, erection problems, reduced sensation and so forth). Sometimes there are rectal problems including difficulty with passage, painful and/or frequent bowel movements.
A series of three injections of medication into the area around the nerve may provide long-term relief of pain. The goal is to interrupt the pain mechanisms and to stop the process of nerve irritation. One medication acts as a local anesthetic, like you would receive for dental work. This medication "settles" the nerve signals to the spinal cord. The anesthetic response is almost immediate and may last for a few to several hours. The pain relief occasionally lasts for one to two days and rarely for one to two weeks.
The second medication is a steroid that helps reduce swelling and inflammation. It may, in some cases, provide more space around the nerve by decreasing the amount of fat. It is the same medication used in painful joints. Doctors use these two medicines to treat carpal tunnel syndrome. The degree and duration of pain relief you experience after these injections will help guide decisions regarding future treatment.
Injections can reduce or totally eliminate the pain. Sometimes a fourth injection will be recommended when the patient is having good but not complete relief.
Pain scores and urologic scores (if necessary) will be completed and monitored throughout your treatment.About your procedure
The injections are usually given in both buttocks. Only one side will be injected if pain exists only on that side. A series of three injections are given at four week intervals to allow time for the steroid medication to work before the next injection is given.
Dr. Antolak will perform the first two injections using a fluoroscope for guidance. No special preparation is needed prior to the procedure. You should be able to drive after your procedure. It would be wise to have a companion along in case one or both legs are "rubbery" after the injections. A follow-up appointment is scheduled for two hours after your injection.
The third injection in the series is deeper into the pelvis and requires special imaging to guide the placement of the medicine into the Alcock canal. A radiologist will perform this injection and use a CT scanning unit for guidance. Again, a follow-up appointment is scheduled for two hours after your injection.
Please arrive early for check in. You will then change into a gown and be escorted into a room containing the fluoroscope unit. This allows Dr. Antolak to see the physical landmarks to assist in identification of the nerve pathway. The skin will be cleansed with Betasept (a surgical soap), and you will receive an injection of a local anesthetic to numb the area and the muscle through which the needle will pass.
The medication will be injected into the pathway of the nerve between two ligaments where the most benefit will occur. You will be asked to tell us when the needle is causing complaints similar to the ones you usually have. This helps us position the needle near the nerve for the best placement of the medicines. You may have tingling or other sensations in the same place you have been having your long term pain. You may experience pain if a nerve is "touched" during the injection, however, this is rare. We always check for bleeding. We cannot inject the medicines if the needle causes any bleeding.
We will check to see how you are feeling after the injection. Tell the staff if you experience any sweating or weakness caused by the stress of the procedure. Most people are surprised at the ease of the injection procedure.
You must be examined after the injection to determine the immediate response to the local anesthesia. We like to do this about two hours after the injection.
The following side-effects may last from one to six hours and are normal:
- Discomfort at the injection site.
- Numbness in your anal and genital area.
- A bowel movement may feel different since a branch of the nerve goes to the rectum.
- Rarely, passing of gas without awareness.
- Rarely, dribbling of urine at the end of the stream.
Short-term muscle weakness in your legs or numbness in the back of the thigh may be caused by the local anesthesia. Most people are able to drive after the procedure. However, if there is "drifting" of the anesthesia to the sciatic nerve, you should wait until there is no longer any muscle weakness. A person occasionally requires a wheel chair for one to two hours. It would be best if a family member or friend accompany you in case you need driving assistance.
The initial anesthetic will wear off after a few hours. It sometimes lasts a day, or up to three or four days, which is a wonderful response when it occurs. The second medication will begin to provide long-term relief after seven to ten days. About 65% of people experience improvement after three injections. Often, no further treatment is necessary. Occasionally a fourth injection is offered. Surgical treatment may be needed if the injections do not provide lasting relief. The ongoing pain scores allow comparison to your original pain levels.
Complications with pudendal nerve injections are rare. However, they may include the following:
- Rarely is there an allergic response of hives, etc., or similar problems from the local anesthetic.
- Some people have noticed a flushing problem from the steroid medications. Bruising may occur at the injection sites. You may choose to stop aspirin for one week prior to the injections.
- Only one or two injections out of many hundreds caused some bleeding around the nerve. That is like any other bruise and will eventually heal.
- There may be an increase in pain in the area you usually have pain. It can be bothersome. This may last a few days until the second medication begins to work.
- The anesthetic medicine occasionally "drifts" to the sciatic nerve. Some people have numbness in the leg. Others not a "rubber-leg" with muscles that do not work well for one to four hours. Rarely, a wheel chair is necessary for transport. You should be able to drive after three to four hours.
- Steroid medication can cause emotional stress for a few days in some people.
- Bone changes are seen with different doses and long term steroid treatment. We have not seen one in more than 3,000 injections.
- Ulcers have never been reported after these injections but have occurred from other steroid use.
- Mild acne eruption has been noted by some patients.
- Menstrual changes are rare but may occur.
Please call MAPS Pain Clinics (763) 537-6000 if you have any questions about your injections or the information in this handout. We will try to guide you to some comfort in understanding the issues involved.