PAIN BE GONE

Trigger Happy

                                                                  by Debra Walter, M.D.  

Trigger points (TrPs) are defined by Drs. Janet Travell and David Simons as a taut band within a muscle that twitches when plucked like a string. These are muscular knots that can actually be palpated. Trigger points are either quiet (latent), with or without mild tenderness, or they are active. When activated by stress, injury or habitual holding patterns, they can cause considerable pain and refer into distant sites, usually in fairly predictable patterns. Eventually, this progressive pattern can create satellites with widespread myofascial dysfunction and pain (myofascial pain syndrome or MPS). 

Under a microscope, trigger points are invisible. The only hint of their existence is slight staining changes con­sistent with abnormal oxygen metabolism. The most widely accepted theory is that activated TrPs are caused by an overactivity involving part of the sympathic nervous system. This continually excites the sensory organs that read the position and tightness of the muscle, thus irritating and “hyper-contracting” the bands of muscle containing these trigger points. We all have some trigger points, probably caused by the chronic muscle tightness required to hold ourselves upright and move around. Of course, tension and stress also contrib­ute.

If you have fibromyalgia (FM), you may or may not have trigger points (or myofascial pain). Those with FM experience generalized sensitivity or a diffuse all-over achiness. For those with myofascial pain, however, there are specific pains in specific areas, and in the areas not affected with TrPs, there is no pain. Unfortunately, many with FM also have specific or widespread myofascial pain (MPS).To make matters worse, poor sleep and chronic muscular dysfunction, associated with fibromyalgia, can make trigger points more prominent and difficult to deal with. 

So how do you disarm trigger points? Trigger points are best treated by first deactivating them as much as pos­sible, then stretching and gradually reconditioning the muscle. The underlying causes should be considered and addressed to avoid setting them off again. Deactivation is accomplished through massage, other forms of manual soft tissue release, stretching, and, if needed, injections. This article will describe the injection process. However, other modalities can be just as important in recovery. 

Injections are extremely helpful for deactivating tender, active trigger points. They can be less painful than massage, give quicker relief, and allow the patient to begin the process of lengthening and retraining the muscle. In addition, areas can be treated that are not always accessible to massage. Most trigger point injections are done with a local anesthetic directly into the taut band. This makes sense when you consider that these bands are really over-activated sections of muscle, and injections interrupt the nerve flow to the muscle, temporarily breaking up the vicious cycle of spasm and pain. Theoretically injections can lower sympathetic in­put (the part of your nervous system that responds to fright) and abolish the trigger point.

The local anesthetics commonly used are lidocaine (or Xylocaine, most commonly used by the dentist); procain (preferred by some and, in theory, less irritating to muscle but more expensive and more difficult to find); or bupivacaine (Marcaine, which is similar but longer act­ing). Some practitioners add small amounts of cortisone, but the original developers of the trigger point injections did not think this was necessary. In fact, use of cortisone appears to be implicated with mild, microscopic, muscle injury and aggravation. However, after administering trigger point injections for the last 12 years, I have seen relatively few negative effects. Nonetheless, I only rarely add a little cortisone. A new twist in the treatment of TrPs has been the introduction of Botox. I think this can be very helpful in certain patients, but the points need to be identified first with more conventional injec­tions and the underlying causes evaluated. 

Second to understand­ing the cause of trigger points, the most impor­tant aspect of TrP injec­tions is the selection of points to inject. Ideally there is a twitch reaction or reproduction of the symptoms when active areas are touched by the needle. Usually trigger points occur in groups with key and satellite muscles. Careful examination of the soft tis­sue and some knowledge of typical referral patterns are important in identifying the active trigger point areas. Finding the key point is ideal, but sometimes this can be extremely difficult. Sometimes the most important mus­cles are distant from the site of pain. Muscles around the shoulder blade refer to the mid back and arm; muscles in the neck refer to the head, arm and shoulder; and mus­cles in the low back and buttocks refer to the leg. The muscles involved with temporomandibular joint dys­function are very deep and difficult to examine and can produce profound ongoing pain syndromes. Deactivat­ing as many points as possible, sometimes with a series of injections, usually helps sort things out. Acupuncture points follow a different pattern and are not defined in the same way.

What about side effects from all of this poking and prodding? Thankfully, they are minimal. Bruising can be a problem in patients treated with blood thinners, so extra care should be taken. Many patients with fibromy­algia experience muscle soreness following the injections, with variable amounts of relief a few days later. Allergies to the medicine are an occasional problem. Caution also has to be used around the chest and upper shoulders to avoid causing a pneumothorax, a complication that oc­curs when the lung is pierced by a needle. Occasionally a temporary nerve block can occur, which is not danger­ous and resolves as the medication wears off. 

In conclusion, trig­ger point injections are safe and can be dramati­cally helpful. Results can last long after the anes­thetic wears off, but this of course depends on the underlying reason for the problem. Injections can be useful in managing pain temporarily when related to more perma­nent conditions and al­low the opportunity to correct other factors as much as possible.  In short, they can make a dramatic change in a treatment program or provide no relief at all. Even if no relief is achieved, however, TrP injections can help direct the treatment to­ward other muscles or a search for other reasons to ex­plain the pain

One last thought: a trigger point injection is only ef­fective if the target is hit. This takes a great deal of “target practice.” Consider seeking out physicians who special­ize in trigger point injections as they will more likely hit the bull’s-eye.