TRIGGER POINT THERAPY BOOK MYOFASCIAL SYNDROMES DIAGNOSIS Patients with chronic myofascial pain are people who have suffered more than just pain for many months or longer. The severity and chronicity of their "untreatable" pain has often reduced their physical activity, limited participation in social activities, impaired sleep, induced a major or minor degree of depression, caused loss of role in the family, led to loss of employment, and deprived them of control of their lives. Many have been depersonalized by the ultimate indignity-the conviction that their pain is not "real," but psychogenic. Wellmeaning practitioners sometimes have also convinced the patients' families and friends that the pain is not real, leaving many patients nowhere to turn for help. The patients come to the clinician seeking relief from their suffering, which they may present only in terms of pain. When examining the patient who has presented with chronic enigmatic pain, the diagnostician must first conduct a thorough, timeconsuming history and physical examination to identify what conditions are contributing to the patient's pain and to determine whether there is a significant myofascial component. If it appears likely that the patient does have chronic myofascial pain syndrome, the diagnostic task becomes twofold. In addition to identifying which TrPs, in which muscles, are causing what portion of the patient's total pain complaint, the examiner must determine what perpetuating factors converted the initial acute myofascial pain syndrome to a chronic one. Myofascial TrPs may be perpetuated by mechanical (structural or postural) factors, by systemic factors, by associated medical conditions, and by psychological stress. The central nervous system powerfully modulates pain input from the muscles in ways that can explain referred pain and altered sensation from TrPs. In phase 1 (constant pain from severely active TrPs), patients may already have such intense pain that they do not perceive an increase and cannot distinguish what makes it worse. Phase 2 (pain from less irritable TrPs that is perceived only on movement and not at rest) is ideal for educating the patient as to which muscles and movements are responsible for the pain, and how to manage it. In phase 3 (latent TrPs that are causing no pain), the patient still has some residual dysfunction and is vulnerable to reactivation of the latent TrPs. Myofascial Physical Examination Specific myofascial examination of the muscles is undertaken following a complete general physical examination. When searching for active TrPs that are responsible for the patient's pain, it is essential to know the precise location of the pain and to know which specific muscles can refer pain to that location. Muscles that could be causing the pain are tested for restriction of passive stretch range of motion and for pain at the shortened end of active range of motion, as compared with uninvolved contralateral muscles. Suspected muscles are also tested for mild to moderate weakness either by conventional isometric strength testing or during a lengthening contraction. Such weakness is not associated with atrophy of the muscle. The muscles showing abnormalities in these tests are the ones most likely to have the taut bands and spot tenderness of the TrP. The taut bands are located by palpation and then tested for a local twitch response and reproduction of the patient's pain complaint by digital pressure on the TrP. One must try to distinguish active TrPs from latent ones, which can also respond positively to the tests described but are not responsible for a pain complaint. Active TrPs are more irritable than latent TrPs and show greater responses on examination. If inactivation of the suspected TrP does not relieve the pain, it may either have been a latent TrP or it may not have been the only active TrP referring pain to that area. Examination for mechanical perpetuating factors requires careful observation of the patient's postures, body symmetry, and movement patterns. Common mechanical factors that can influence many muscles are the round-shouldered, head-forward posture with loss of normal lumbar lordosis, and body asymmetries including a lower limb-length inequality and a small hemi-pelvis. Tightness of the iliopsoas and hamstring muscles can also seriously disrupt balanced posture. DIFFERENTIAL DIAGNOSIS Two variants of myofascial pain syndromes should be recognized: the myofascial pain modulation disorder, which leads to diagnostic confusion, and the post-traumatic hyperirritability syndrome, which complicates management. In addition, either fibromyalgia or articular dysfunction can confusingly mimic a chronic myofascial pain syndrome. Each requires an additional specific examination technique and its own treatment approach. Myofascial Pain Modulation Disorder It appears that the aberrant referral patterns are caused by a distortion of sensory modulation in the central nervous system. Many of these patients had previously experienced trauma or painful impact at the focus of pain, but often not of such severity that it would be expected to cause structural damage to the central nervous system. The mechanism behind this sensory nervous system dysfunction is not clear, but possible mechanisms are being explored in current neurosensory research. Post-traumatic Hyperirritability Syndrome This syndrome follows a major trauma, such as an automobile accident, a fall, or a severe blow to the body that is apparently sufficient to injure the sensory modulation mechanisms of the spinal cord or brain stem. The patients have constant pain, which may be exacerbated by the vibration of a moving vehicle, by the slamming of a door, by a loud noise (a firecracker at close range), by jarring (bumping into something or being jostled), by mild thumps (a pat on the back), by severe pain (a TrP injection), by prolonged physical activity, and by
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