Myofascial Injection

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Dr. Carter: "Hello. I'm Dr. Jim Carter from Mission Viejo, California, and I'm here at the International Pelvic Pain Society meeting in Connecticut with John Slocumb, M.D., who is at the University of Colorado and is Director of their pelvic pain program. John, I can remember my earliest times visiting with you when you were in Mexico. I went into your facility, and you were doing trigger point injections or injections for treatment of chronic pain as part of a landmark study that you published on abdominal wall myofascial syndrome and pelvic pain related to this condition. Could you describe your work for us?"

Dr. Slocumb: "Jim, that was a fascinating period of time for me, in that in the mid- to late-70's, I found the patients in whom I was performing this standard therapy of chronic pelvic pain - total hysterectomy - had the same identical pain afterwards. There would be a period of six weeks to a couple of months in which the pain would be gone; the patient would be most thankful. The pain was cured only to have the exact same sensation return in spite of the absence of the uterus and the ovaries in many cases. This raised a question about what was actually hurting, and being a gynecologist, of course, we always focus on the uterus and the reproductive tissues. This obviously wasn't the case, there was a more complex mechanism involved. So the first attempt that I tried to look at was to actually identify what hurt. The initial approach was to take a needle and some local anesthetic and place the needle where the patient said the pain was, go deep enough to reproduce it with a needle, and then block it and see what happened to the pain. And lo and behold, the major focus in over 90% of the patients was a layer of fascia in the wall of the abdomen. So by placing the needle over the area where the patient provided to identify her painful area, place the needle over the skin of the abdomen, penetrate a matter of a ½" - 1", the patient would suddenly jump and say, "That's my pain!" This identified a tissue source but not necessarily mechanism. A way to confirm that was then to inject a local anesthetic into these tender areas or so called "trigger areas," and then have the patient walk out of the room saying, "This is the first time my pains been gone in years." The source of the pain, the wall of the abdomen, really did not indicate why I was there; there was nothing wrong with the wall of the abdomen but this corresponded neurologically to the referral area of internal organs. So we can actually map out these referral fascial layers of the wall of the abdomen and their associated referral areas. The lateral areas of the abdomen indicated referral from the ureter and lateral aspects of the bladder, the central layer of the abdomen referral from the bladder and the uterus itself, the mons pubis area referral from the trigon of the bladder; so that in this mapping we could identify the real and somatic mechanisms of this manufactured pain."

Dr. Carter: "I recall that, in fact, it was in '79-'80 that I visited you, and that's when you were at the University of New Mexico and then later at the University of Colorado you continued that work looking for the source and also continuing the mapping. Now you've also found that these injections work if they were done intravaginally - into the muscle and fascia layers of the levator ani and the obturator internus. Can you describe for us then the technique that you use for those type of trigger points?"

Dr. Slocumb: "Here again, the crucial issue is to identify the actual focus or trigger area. The finger sometimes, certainly two fingers in the vagina and one in the abdomen, was too blunt in approach to identify very focal areas of neuropathy or focal areas of pain. Also noted was that a focal area of pain, particularly in the scar tissue of the top of the vagina after hysterectomy or in the tissue around the levator sling, can produce surrounding referral so that the patient has multiple areas of pain on exam but this is not necessarily the cause. So one can use a small Q-tip or the back end of a large text of swab to just systematically go through these very sensitive tissues and find a focus that seems to be a central sharp stabbing area with firm pains to the other areas. Then again using the block technique to identify that as a source (blocking one area takes away pain in multiple areas) is very helpful. So, the levator sling can focal trigger areas in the vulvar area, and in my experience, the worst area is the paracervical area before a hysterectomy or the scar tissue of the vaginal cuff after a hysterectomy. These occur to be neuromas, occasionally we can find a little foci of endometriosis, but clearly the scar tissue seems to embellish the sensation, spreading it to other areas and becoming a major focus. These patients on pelvic exam have a lot of pain with insertion of the speculum, certainly with the bimanual, and certainly with a history of significant sharp pain with intercourse."

Dr. Carter: "So the technique that you employ is to use the back side of the Q-tip to palpate with a very small focus rather than using even one or two fingers to palpate those areas to identify an area where the individual gives you a report of the pain that they're experiencing. Then to focus on that to see if you can remove that pain with an injection, and identify that that truly is the focus. As you approach these patients and you do your physical examination and you find the guitar string finding of the cord with the trigger point imbedded that sometimes occurs - and I find in the levator ani - when you inject those, do you find those generally softened quite a bit?"

Dr. Slocumb: "That's really a good point - one of the observations that you want to make is not only is the pain gone for the duration of the local anesthetic, but you see changes in the tissues around it. The tension in the muscles seems to relax considerably and the decrease in tension gives them additional pain relief. The local anesthetic may have a prolonged affect that lasts for days and sometimes weeks because of the blocking of a nerve reflex, indicating again a neurologic mechanism of this rather than a focal disease in that area. Patients have learned over a period of time that when they are threatened with a pelvic exam or intercourse that those muscles reflexively tense and tighten - again intensifying the sensitivity and the pain in that area. They really need to relearn to relax, and when they do that they take away the original focal pain mechanism by and by. So I think your observation of tension was a good way to identify where that's coming from."

Dr. Carter: "So summarize this briefly - you do the exam with a finer instrument than our fingers generally. You find an area where there's a focus of tenderness, or let's say a guitar string-type area of muscle, that support we could call the epithelial and the central very strong focus of pain, and then you will say do an injection. Now just for those who don't do this technique, what size needle do you use, how much do you inject and what do you…?"

Dr. Slocumb: "The smaller the needle the better, in order to minimize the discomfort of the injection itself, so I usually use 25's and others use even smaller - up to 30 size needles. On the other hand, the smaller the needle, the tendency to pass through the tissue without really reducing the pain can be a problem as well. So what you want to do with your needle technique is, instead of just penetrating, to very slowly move the needle with a back and forth motion so you can get enough tissue stimulus that when you hit the hyperpathic point, the patient is obsessed by pain. Then you're able to stop and infiltrate adequately, and again these areas may be pretty small but you want enough volume of local anesthetic. A weak concentration of Marcaine would be adequate to infiltrate the area to get the block to cover the tender area. Another question is - is this really muscle or is this fascia? And people, of course, describe mild fascial pain, and Janet Travell talked a lot about the mild fascial pain and muscles with referral areas and trigger areas as being the original researcher to describe these syndromes but much of the tissue actually is fascia. The muscle may be more to reactive, of course, and muscle and fascia go together. We have to really recognize that we use the needle to identify the tissue source, and we use the block to tell where it's coming from, and what the nerve mechanism is really is not clear. The abdominal wall pretty clearly in my experience is fascial; there's no muscle component to it. It's really well above the rectus muscle and the obliques; you're really into Scarpa's fascia. Our neurometric studies reflect that there is actually abnormal nerve energy in those areas indicating that there is a central spinal cord mechanism which keeps these areas hypersensitive, and then as a result of the hypersensitivity and the feedback exacerbates the spinal cord component as well."

Dr. Carter: "Very good point. I know in my experience in reporting these injections for the vaginal area, I elect to use in the fascia and levator ani obturator internus a 30-gauge small needle, ½%-1% Lidocaine, 1-2 cc's into these regions is frequently enough for a complete trigger point resolution in one area. For the abdominal wall a larger needle 25, 22, and you may have to go a little bit deeper. On the point of the trigger points, I had a nice conversation with David Simons, who's just completed his latest addition of the 1999 Volume 1 of Simons & Trudels Trigger Point Manual. That is an excellent guide for the knowledge base for the physicians and practitioners on the techniques of trigger points, not only in our region but also for a dentist, general surgeons, and physical therapists. It is a very, very elegant work and has an excellent presentation. On the point that you made on these long lasting effects that you get and the central nervous cord relationship, I know your current work is very deep into how this mechanism is actually functioning. Could you describe some of the current research that's undergoing for us?"

Dr. Slocumb: "Sure, there are a couple of things that we need to recognize here that it's really our instinct to go to where the patient says it hurts and blame that tissue as being the cause, when actually it's the nerves feeding that area that seem to be a interval part of this mechanism. So we blame where it hurts rather then the source of those nerves that are creating this hypersensitive tissue. Unfortunately, we end up doing treatments that actually may make the area worse, like removing organs and doing that nerve surgery to try to change that. So what our research looking at right now is to identify what tissue hurts, what nerve pathways are involved, and then what is an actual mechanism for that. Just to cut the discussion short, my belief is that the origin of these dysfunctions is actually coming from the spinal cord. The tissues we see can be unilateral, can be a dermatome distribution, and there appears to be a very central focus with multiple peripheral tissues from that central focus in the spinal cord. This is why the dermatome component or the somatotome component is critical in trying to understand it. Another frustration is that each of us as specialists tend to look to our organs of specialty without looking at the whole patient, the whole neurologic component to it. Therefore, we tend to develop our own theories and treatments in a very specific for focal organs when this is actually multiple organs involved, this is really a culdomyopathy rather than a disease of the bladder, or the uterus, or the ovaries, or the vulva. Once we broaden our view and broaden our exam, we can understand these better. Research wise there's not a whole lot done in terms of nerve transmitter dysfunction, but I think that's where we really need to go to understand these mechanisms and examples of vulvodynia. The focus of our observation is the redness around the vestibula gland, and the pattern is really consistent with a nerve transmitter altering the threshold coming from the secretions of the gland itself. That obviously is an area where research will give us some better insights in managing this - rather than grossly removing the whole tissue as it seems to be recommended in some centers."

Dr. Carter: "John, one of the things I want to express is my appreciation to you for being open to me, coming as this was when I was completing my medical school and traveling and looking at what people were doing in new areas. You pioneered and introduced this, and the fact is that you have pursued what is causing the pain of a woman whose gynecologic organs have been removed. And yet, you as a gynecologist saying - "Wait, the problem is still there, I'm going to pursue this and find out" - has opened up an area for gynecologists which we're now realizing. Our old way of examining the patient simply is an old way, and you've been teaching us. The students at the University of Colorado are so fortunate to have you there to give them the insight, and the people in Colorado who get those residents into their community because they're so well served, and as a result, hysterectomies are not only not necessary but they know they won't solve the problem, and in fact, the problem is coming from another source. Then this way, people are not getting surgery, they're getting therapeutic intervention for their problem, and as I understand it, that the injection although it only lasts for awhile may uncouple this relationship between the central nervous system and that peripheral stimulus. So the person might have had a fall ten years ago, developed this problem, and what you've done is uncouple it by doing the injection therapy so that they no longer feel the pain. The stimulus is long gone, it's all wrapped into this circuit. Is that a correct summation?"

Dr. Slocumb: "I think that's a very good description. That there are peripheral sensitized tissues that normal physiologic functions such as a menstrual period or filling of the bladder, full bladder, intercourse, sometimes orgasm can turn the pain on; often we see it in association with ovulation. These are normal physiologic functions, but when they occur in an area that has been sensitized, they end up becoming a major painful experience for the patient, and we keep blaming the event rather than the threshold involved in these tissues. As you know, the best way we can learn about this - a condition that is not well understood - is to listen to the patient. I can't teach anybody anything that any patient can't teach them. As long as we listen, believe what they say, try to explain what they're telling us in physiologic or pathologic terminology, and if our language isn't adequate to explain it, go back to the drawing board and find a better way to understand it."

Dr. Carter: "Two things you said, one is to listen to the patient. The other thing that is that after learning this type of exam, as Dr. Slocumb has pointed out, and proceeding with a trial injection, that patient will say, "That's where my pain was and now that pain is gone." Those are words I've heard over and over again from my patients following your techniques, following the work that you've taught me, and I really thank you."

Dr. Slocumb: "Thank you. It's been a pleasure."