Hair Follicle Melanocytes Initiate Autoimmunity in Alopecia Areata: a Trigger Point.

Alopecia areata (AA) is characterized by common non-scarring alopecia due to autoimmune disorders. To date, the specific pathogenesis underlying AA remains unknown. Thus, AA treatment in the dermatological clinic is still a challenge. Numerous clinical observations and experimental studies have established that melanocytes may be the trigger point that causes hair follicles to be attacked by the immune system. A possible mechanism is that the impaired melanocytes, under oxidative stress, cannot be repaired in time and causes apoptosis. Melanocyte-associated autoantigens are released and presented, inducing CD8+ T cell attacks. Thereafter, amplification of the immune responses further spreads to the entire hair follicle (HF). The immune privilege of HF subsequently collapses, leading to AA. Herein, we present a narrative review on the roles of melanocytes in AA pathogenesis, aiming to provide a better understanding of this disease from the melanocyte's perspective.

Inhibition of Peripheral ERK Signaling Ameliorates Persistent Muscle Pain Around Trigger Points in Rats.

The purpose of this study was to investigate whether the ERK signaling pathway was involved in ameliorating chronic myofascial hyperalgesia from contused gastrocnemius muscle in rats. We established an animal model associated with myofascial pain syndrome and described the mechanism of muscle pain in an animal model. Changes in the mechanical pain threshold were observed 0.5, 1, 2, 3, 4, 5, 8, 12, 18, and 24 h after ERK inhibitor injection around myofascial trigger points (MTrPs) of the gastrocnemius muscle in rats. Morphological changes in gastrocnemius muscle cells were observed by hematoxylin and eosin (H&E) staining. ERK signaling pathway activation was detected through immunohistochemistry and Western blotting. The main morphological characteristics of injured muscle fibers around MTrPs include gathered circular or elliptical shapes of different sizes in the cross-section and continuous inflated and tapering fibers in the longitudinal section. After intramuscular injection of U0126 (ERK inhibitor), the mechanical pain threshold significantly increased. The reduction in mechanical hyperalgesia was accompanied by reduced ERK protein phosphorylation, myosin light chain kinase (MLCK) protein, p-MLC protein expression, and the cross-sectional area of skeletal muscle cells around MTrPs. An ERK inhibitor contributed to the attenuation of mechanical hyperalgesia in the rat myofascial pain model, and the increase in pain threshold may be related to MLCK downregulation and other related contraction-associated proteins by ERK.

A Comprehensive Review of the Diagnosis, Treatment, and Management of Urologic Chronic Pelvic Pain Syndrome.

PURPOSE OF REVIEW: Urologic chronic pelvic pain syndrome (UCPPS) is a chronic, noncyclic pain condition which can lead to significant patient morbidity and disability. It is defined by pain in the pelvic region, lasting for greater than 3 to 6 months, with no readily identifiable disease process. The aim of this review is to provide a comprehensive update of diagnosis and treatment of UCPPS. RECENT FINDINGS: UCPPS encompasses chronic pelvic pain syndrome or chronic prostatitis (CP/CPPS) in men and interstitial cystitis or painful bladder syndrome (IC/PBS) in women. Underlying inflammatory, immunologic, and neuropathic components have been implicated in the pathogenesis of UCPPS. For optimal patient management, an individualized and multimodal approach is recommended. Medical management and physical therapy are the mainstays of treatment. Injection therapy may offer additional relief in medically refractory patients. Further minimally invasive management may include spinal cord and peripheral nerve stimulation, though evidence supporting efficacy is limited.

Active Trigger Points Are Associated With Anxiety and Widespread Pressure Pain Sensitivity in Women, but not Men, With Tension Type Headache.

BACKGROUND: A better understanding of gender differences can assist clinicians in further developing therapeutic programs in tension type headache (TTH). OBJECTIVE: To evaluate gender differences in the presence of trigger points (TrPs) in the head, neck, and shoulder muscles and their relationship with headache features, pressure pain sensitivity, and anxiety in people with TTH. METHODS: Two hundred and ten (59 men, 151 women) patients with TTH participated. TrPs were bilaterally explored in the temporalis, masseter, suboccipital, upper trapezius, splenius capitis, and sternocleidomastoid muscles. Headache features were collected using a 4-week headache diary. Trait and state anxiety levels were assessed using the State-Trait Anxiety Inventory. Pressure pain thresholds (PPTs) over the temporalis, C5/C6 joint, second metacarpal, and tibialis anterior were assessed. RESULTS: Women with TTH exhibited a significantly higher number of total (P = 0.027) and active (P = 0.030), but similar number of latent (P = 0.461), TrPs than men with TTH. Active TrPs in the temporalis, suboccipital, and splenius capitis muscles were the most prevalent in both men and women with TTH. The number of active TrPs was associated with anxiety levels (r = 0.217; P = 0.045) in women, but not in men (P = 0.453): the higher the number of active TrPs, the more the trait levels of anxiety. Women exhibited lower PPTs than men (all, P < 0.001). In men, the number of active, but not latent, TrPs was negatively associated with localized PPTs (all, P < 0.05), whereas in women, the number of active and latent TrPs was negatively associated with PPTs in all points (all, P < 0.01): the higher the number of TrPs, the lower the widespread PPTs. CONCLUSIONS: This study described gender differences in the presence of TrPs in TTH. Women with TTH showed lower PPTs than men. The association between TrPs, anxiety levels, and pressure pain hyperalgesia seems to be more pronounced in women than in men with TTH.

The prevalence of myofascial trigger points in neck and shoulder-related disorders: a systematic review of the literature.

BACKGROUND: Neck and shoulder disorders may be linked to the presence of myofascial trigger points (MTrPs). These disorders can significantly impact a person's activities of daily living and ability to work. MTrPs can be involved with pain sensitization, contributing to acute or chronic neck and shoulder musculoskeletal disorders. The aim of this review was to synthesise evidence on the prevalence of active and latent MTrPs in subjects with neck and shoulder disorders. METHODS: We conducted an electronic search in five databases. Five independent reviewers selected observational studies assessing the prevalence of MTrPs (active or latent) in participants with neck or shoulder disorders. Two reviewers assessed risk of bias using a modified Downs and Black checklist. Subject characteristics and prevalence of active and latent MTrPs in relevant muscles was extracted from included studies. RESULTS: Seven articles studying different conditions met the inclusion criteria. The prevalence of MTrPs was compared and analysed. All studies had low methodologic quality due to small sample sizes, lack of control groups and blinding. Findings revealed that active and latent MTrPs were prevalent throughout all disorders, however, latent MTrPs did not consistently have a higher prevalence compared to healthy controls. CONCLUSIONS: We found limited evidence supporting the high prevalence of active and latent MTrPs in patients with neck or shoulder disorders. Point prevalence estimates of MTrPs were based on a small number of studies with very low sample sizes and with design limitations that increased risk of bias within included studies. Future studies, with low risk of bias and large sample sizes may impact on current evidence.

Novel method to measure active myofascial trigger point stiffness using ultrasound imaging.

INTRODUCTION: Myofascial trigger points (MTrPs) are one of the most common and important causes of musculoskeletal pain. Ultrasound is a useful modality in examining musculoskeletal disorders. By applying compressive stress and observing changes in ultrasound images, the elastic modulus (Young's modulus) can be calculated. Our objective was to develop a novel method to distinguish MTrPs from normal tissues. METHODS: A total of 29 subjects with MTrP in the sternocleidomastoid muscle were assessed. A force gauge was attached to a transducer to obtain stress levels. To obtain strain, images were recorded in both with stress and without stress states. By dividing the stress level by the measured strain, the elastic modulus was determined. RESULTS: Elastic modulus in MTrPs and the normal part of the muscle were measured to be 13379.57 ± 1069.75Pa and 7078.24 ± 482.92Pa, respectively (P = 0.001). This indicated that MTrPs were stiffer than normal parts of the muscle. CONCLUSION: This study presents a new method for the quantitative measurement of the elastic modulus of MTrP, thereby distinguishing MTrPs from normal adjacent muscular tissue, with more simplicity and lower cost, compared to other ultrasound methods.

A case study utilizing myofascial release, acupressure and trigger point therapy to treat bilateral "Stringhalt" in a 12 year old Akhal-Teke horse.

"Stringhalt" is a horse condition that causes one or both hind legs to spasm when walking, trotting or backing. The condition is thought to be related to a neurological cause from either plant toxicity or peripheral nerve injury. The prognosis is poor and the horse's performance and quality of life can be affected. Treatment has included surgically cutting the digital extensors with varied results. The objective of the study is to utilize soft tissue release via acupressure, trigger point and myofascial release to decrease symptoms of stringhalt. The case study is a 12 year old Akhal-Teke horse of excellent pedigree. In 2011, she was caught in barbed wire overnight and sustained lacerations to the bone in her hindlimbs. Shortly after the injury the horse was placed in a stall for several months and was unable to walk or run, developing stringhalt. Currently, her condition is aggravated by stress and alleviated by certain types of massage (myofascial, acupressure, and trigger point release). The incidence of stringhalt occurs every 3-5 min, with more frequent and severe symptoms on the right hindlimb. The horse is unable to run or back up. Six 1 to 1½ hour bi-weekly treatments were performed. The treatments consisted of myofascial release at the cervical, sacrum and iliums, acupressure of the bladder meridian (including c-spine, t-spine, l-spine, and hamstring), and trigger point release of the iliacus. The stringhalt symptoms were monitored for 30 min prior to each of the 6 treatment sessions. After 6 treatments, the horse was observed running and standing in a position that promotes hip extension. She has not been able to do either since the injury. The frequency and severity of the spasms have decreased to every 10-20 min. The horse's owners report that her disposition, stress and quality of life are much improved. The results suggest that myofascial release, acupressure and trigger point therapy may be utilized to provide a positive treatment outcome in the case of stringhalt. However, please note that the scope of practice varies by state and special training is needed to work with the equine population.

Biological effects of direct and indirect manipulation of the fascial system. Narrative review.

INTRODUCTION: Osteopathic Manipulative Treatment (OMT) is effective in improving function, movement and restoring pain conditions. Despite clinical results, the mechanisms of how OMT achieves its' effects remain unclear. The fascial system is described as a tensional network that envelops the human body. Direct or indirect manipulations of the fascial system are a distinctive part of OMT. OBJECTIVE: This review describes the biological effects of direct and indirect manipulation of the fascial system. MATERIAL AND METHODS: Literature search was performed in February 2016 in the electronic databases: Cochrane, Medline, Scopus, Ostmed, Pedro and authors' publications relative to Fascia Research Congress Website. RESULTS: Manipulation of the fascial system seems to interfere with some cellular processes providing various pro-inflammatory and anti-inflammatory cells and molecules. DISCUSSION: Despite growing research in the osteopathic field, biological effects of direct or indirect manipulation of the fascial system are not conclusive. CONCLUSION: To elevate manual medicine as a primary intervention in clinical settings, it's necessary to clarify how OMT modalities work in order to underpin their clinical efficacies.

Effect of self-myofascial release on myofascial pain, muscle flexibility, and strength: A narrative review.

BACKGROUND: Numerous techniques have been employed to treat myofascial pain syndrome. Self-myofascial release (SMFR) is a relatively new technique of soft tissue mobilization. The simplicity and portability of the SMFR tools allow it to be easily implemented in any type of fitness or rehabilitation program. It is an active method and can be used by anyone at home or at the workplace. OBJECTIVE: To review the current methods of SMFR, their mechanisms, and efficacy in treating myofascial pain, improving muscle flexibility and strength. METHODS: PubMed, Google Scholar, and PEDro databases were searched without search limitations from inception until July 2016 for terms relating to SMFR. RESULTS AND CONCLUSIONS: During the past decade, therapists and fitness professionals have implemented SMFR mainly via foam rolling as a recovery or maintenance tool. Researchers observed a significant increase in the joint range of motion after using the SMFR technique and no decrease in muscle force or changes in performance after treatment with SMFR. SMFR has been widely used by health-care professionals in treating myofascial pain. However, we found no clinical trials which evaluated the influence of SMFR on myofascial pain. There is an acute need for these trials to evaluate the efficacy and effectiveness of SMFR in the treatment of the myofascial syndrome.

Muscle Trigger Points and Pressure Pain Sensitivity Maps of the Feet in Women with Fibromyalgia Syndrome.

OBJECTIVE : To investigate the presence of trigger points (TrPs) in feet musculature and topographical pressure sensitivity maps of the feet as well as the relationship between TrPs, pressure pain maps, and clinical variables in women with fibromyalgia (FMS). METHODS : Fifty-one FMS women and 24 comparable healthy women participated. TrPs within the flexor hallucis brevis, adductor hallucis, dorsal interossei, extensor digitorum brevis, and quadratus plantae, as well as external and internal gastrocnemius, were explored. Pressure pain thresholds (PPTs) were assessed in a blind manner over seven locations on each foot. Topographical pressure sensitivity maps of the plantar region were generated using the averaged PPT of each location. RESULTS : The prevalence rate of foot pain was 63% (n = 32). The number of active TrPs for each FMS woman with foot pain was 5 ± 1.5 without any latent TrPs. Women with FMS without foot pain and healthy controls had only latent TrPs (2.2 ± 0.8 and 1.5 ± 1.3, respectively). Active TrPs in the flexor hallucis brevis and adductor hallucis muscles were the most prevalent. Topographical pressure pain sensitivity maps revealed that FMS women with foot pain had lower PPT than FMS women without pain and healthy controls, and higher PPT on the calcaneus bone (P < 0.001). CONCLUSIONS : The presence of foot pain in women with FMS is high. The referred pain elicited by active TrPs in the foot muscles reproduced the symptoms in these patients. FMS women suffering foot pain showed higher pressure hypersensitivity in the plantar region than those FMS women without pain.

Treatment of myofascial pain syndrome with lidocaine injection and physical therapy, alone or in combination: a single blind, randomized, controlled clinical trial.

BACKGROUND: Myofascial pain syndrome (MPS) of the shoulder girdle and cervical region is a common musculoskeletal problem that is often chronic or recurrent. Physical therapy (PT) and lidocaine injections (LI) are two treatments with demonstrated effectiveness compared to a control group, however little is known about their combined value. The objective of this study was to determine whether LI into trigger points combined with a PT program would be more effective than each separate treatment alone in improving pain, function, and quality of life in a group of patients with MPS of the shoulder girdle and cervical region. METHODS: A single-blind, randomized, controlled clinical trial (RCT) was conducted with three parallel groups in the Departments of Physical Medicine and Rehabilitation of two urban hospitals in Medellin, Colombia. One hundred and twenty seven patients with shoulder girdle MPS for more than 6 weeks and pain greater than 40 mm on the visual analog scale (VAS) were assigned to 1 of 3 intervention groups: PT, LI, or the combination of both (PT + LI). The primary outcome was VAS pain rating at 1-month post-treatment. The secondary outcomes included VAS pain rating at 3 months, and, at both 1 and 3 months post-treatment: (a) function, evaluated by hand-back maneuver and the hand-mouth maneuver, (b) quality of life, as measured by sub-scales of the Short Form - 36 (SF-36), and (c) depressive symptoms, as measured by the Patient Health Questionnaire - 9 (PHQ-9). Independent t-tests were used to compare outcomes between groups at 1 month and 3 months post-treatment. RESULTS: In the per protocol analysis, there were no significant intergroup differences in VAS at 1 month PT + LI, 40.8 [25.3] vs. PT, 37.8 [21.9], p = 0.560 and vs. LI, 44.2 [24.9], p = 0.545. There were also no differences between groups on secondary outcomes except that the PT and PT + LI groups had higher right upper limb hand-back maneuver scores compared to the LI alone group at both 1 and 3 months (p = 0.013 and p = 0.016 respectively). CONCLUSIONS: The results of this RCT showed that no differences in pain ratings were observed between the individual treatments (PT or LI) compared to the combined treatment of PT and LI. In general, no difference in primary or secondary outcomes was observed between treatments. TRIAL REGISTRATION: NTC01250184 November 27, 2010.

Outcomes of Ultrasound-Guided Trigger Point Injection for Abdominal Wall Pain.

BACKGROUND: Abdominal wall pain (AWP) is an important cause of chronic abdominal pain. History and physical examination are critical to the diagnosis of AWP. Trigger point injection (TPI) using either a steroid or a local anesthetic or a combination of both is often used to treat AWP. AIM: To determine the efficacy of ultrasound-guided TPI and to determine the predictors of a successful response. METHODS: Patients who received ultrasound-guided TPI between July 2010 and June 2011 were surveyed. The primary outcome was determined using the Treatment Efficacy Questionnaire (TEQ). Electronic medical records were reviewed to determine patient, pain and TPI characteristics. Linear regression was used to determine the predictors of a successful response on the TEQ. RESULTS: Right upper quadrant was the most common site of AWP, and the median pain duration was 12 months. Pain was rated as >8 (1-10 scale) by 57 % and 30 % described it as an ache. Narcotic use was reported in 38 %, and 73 % had a history of at least one abdominal surgery. Forty-four of the 120 (37 %) patients met the criteria for responder on the TEQ. Compared to before treatment, 36 % reported being "significantly better" and 22 % "slightly better." Multiple linear regression analysis showed that higher somatization negatively predicted response. None of the other historical, examination or TPI characteristics were associated with response to the TPI. CONCLUSION: TPI can provide significant, long-term symptom relief in a third of patients with chronic abdominal pain attributed to AWP. Somatization was inversely related to the treatment success.

Effect of lidocaine patches on upper trapezius EMG activity and pain intensity in patients with myofascial trigger points: A randomized clinical study.

OBJECTIVE: To compare the effects of 5% lidocaine patches and placebo patches on pain intensity and electromyographic (EMG) activity of an active myofascial trigger point (MTrP) of the upper trapezius muscle. MATERIALS AND METHODS: Thirty-six patients with a MTrP in the upper trapezius muscle were randomly divided into two groups: 20 patients received lidocaine patches (lidocaine group) and 16 patients received placebo patches (placebo group). They used the patches for 12 h each day, for 2 weeks. The patch was applied to the skin over the upper trapezius MTrP. Spontaneous pain, pressure pain thresholds, pain provoked by a 4-kg pressure applied to the MTrP and trapezius EMG activity were measured before and after treatment. RESULTS: Baseline spontaneous pain values were similar in both groups and significantly lower in the lidocaine group than the placebo group after treatment. The baseline pressure pain threshold was significantly lower in the lidocaine group, but after treatment it was significantly higher in this group. Baseline and final values of the pain provoked by a 4-kg pressure showed no significant difference between the groups. Baseline EMG activity at rest and during swallowing of saliva was significantly higher in the lidocaine group, but no significant difference was observed after treatment. Baseline EMG activity during maximum voluntary clenching was similar in both groups, but significantly higher in the lidocaine group after treatment. CONCLUSIONS: These clinical and EMG results support the use of 5% lidocaine patches for treating patients with MTrP of the upper trapezius muscle.

[Myofascial meridional reflexotherapy of scapulohumeral periarthrosis in the course of the combined spa and health resort-based treatment].

The authors draw attention to the role of a whiplash injury in the pathogenesis of scapulohumeral periarthrosis (SHP). Peculiarities of the specific pathological biomechanical changes associated with this condition are described. The study included a group of 64 patients in whom the localization of the myofascial trigger points (MFTT) of the shortened muscles is described with reference to the differential techniques for soft-tissue manual therapy. Spatial emphasis is laid on the diagnostic dynamic ischemic compression of trigger points (TT) for their inactivation using the method proposed by J. Travel in the original modifications proposed by the authors of the present article. The results of the application of myofascial meridional reflexotherapy of scapulohumeral periarthrosis are presented and analysed in the context of the combined spa and health resort-based treatment.

Effect of combination of trigger point injection and stellate ganglion block on non-odontogenic mandibular molar pain referred from masseter muscle: a case report.

We report a case of myofascial pain syndrome (MPS), manifested as nonodontogenic mandibular molar pain referred from the masseter muscle, relieved by a combination of trigger point injection (TPI) and stellate ganglion block (SGB). The patient was a 32-year-old woman who had experienced cold hypersensitivity in the right third mandibular molar 2 months prior to visiting our department. Subsequently, she had visited a family dentist and undergone pulpectomy under local anesthesia. She eventually visited our clinic because there was no marked change in her symptoms. On the first visit, no tooth abnormality was found and the patient was neither anxious nor depressive. Tender points were found in the right masseter and temporal muscles during muscle palpation. Referred pain radiating to the right mandibular molars was observed when pressure was applied to the central portion of the right masseter muscle. As a result, we diagnosed MPS based on evidence of nonodontogenic tooth pain caused by referred pain from the masseter muscle. We performed TPI with 2% lidocaine hydrochloride to the tender point in the masseter muscle. Although the visual analog scale (VAS) pain score dropped from 97 to 36, complete pain relief was not achieved. The TPI was effective for approximately 7 hrs, after which severe throbbing pain returned. The sustained nature of the tooth pain suggested that it was sympathetic nerve-dependent. Subsequently, we performed SGB, resulting in a reduction in the VAS pain score from 90 to 32. Therefore, we performed another TPI and the VAS pain score dropped to 0. We continued SGB and TPI for the next 3 days and the symptoms disappeared. Thus, a combination of TPI and SGB controlled MPS manifested as masseter muscle-mediated nonodontogenic tooth pain.

Myofascial trigger points and innervation zone locations in upper trapezius muscles.

BACKGROUND: Myofascial trigger points (MTrPs) are hyperirritable spots located in taut bands of muscle fibres. Electrophysiological studies indicate that abnormal electrical activity is detectable near MTrPs. This phenomenon has been described as endplate noise and it has been purported to be associated MTrP pathophysiology. Thus, it is suggested that MTrPs will be overlap the innervation zone (IZ). The purpose of this work was to describe the location of MTrPs and the IZ in the right upper trapezius. METHODS: We screened 71 individuals and eventually enrolled 24 subjects with neck pain and active MTrPs and 24 neck pain-free subjects with latent MTrPs. Surface electromyography (sEMG) signals were detected using an electrode matrix during isometric contraction of the upper trapezius. A physiotherapist subsequently examined the subject's trapezius to confirm the presence of MTrPs and establish their location. IZ locations were identified by visual analysis of sEMG signals. IZ and MTrPs locations were described using an anatomical coordinate system (ACS), with the skin area covered by the matrix divided into four quadrants. RESULTS: No significant difference was observed between active and latent MTrPs locations (P = 0.6). Forty-five MTrPs were in the third quadrant of the ACS, and 3 were included in second quadrant. IZs were located approximately midway between the seventh cervical vertebrae and the acromial angle in a limited area in the second and third quadrants. The mean distance between MTrP and IZ was 10.4 ± 5.8 mm. CONCLUSIONS: According to the acquired results, we conclude that IZ and MTrPs are located in well-defined areas in upper trapezius muscle. Moreover, MTrPs in upper trapezius are proximally located to the IZ but not overlapped.

Myoelectrical activity and muscle morphology in a rat model of myofascial trigger points induced by blunt trauma to the vastus medialis.

OBJECTIVES: To explore myoelectrical activity and muscle morphology of myofascial trigger points (MTrPs) in an injury model of rats. METHODS: A total of 24 male SD rats were randomly divided into a control group (group A) and model group (group B). A blunt striking injury and eccentric exercise were applied to the vastus medialis (VM) of rats in group B for 8 weeks. Later, the palpable taut band (TB), local twitch response, myoelectrical activities and morphology in the two groups were examined. RESULTS: An average of 2.5 (30/12) palpable TBs were detected in the VM in group B compared with none in group A. The MTrPs had two types of abnormal potential. Their amplitudes were significantly higher than those in the control group (p<0.01) but their durations showed no significant differences. A series of reflex contractions appeared in groups A and B in response to external stimulation to the ear. Their amplitude and duration in group B were significantly lower than those in group A. A series of lower fibrillation potentials repeatedly occurred in model MTrPs in group B. The morphology of MTrPs showed abnormal muscle fibres with large round or ellipse shapes in cross-section and enlarged tapering shapes in longitudinal section. CONCLUSIONS: Active MTrPs can be provoked by repeated blunt injury. Active MTrPs are a group of muscle fibres with abnormal shapes and abnormal myoelectrical potentials. External stimulation provokes low-voltage responses in MTrPs, which is different from the response of normal muscle fibres.

Thermographic and clinical correlation of myofascial trigger points in the masticatory muscles.

OBJECTIVES: The aim of the study was to identify and correlate myofascial trigger points (MTPs) in the masticatory muscles, using thermography and algometry. METHODS: 26 female volunteers were recruited. The surface facial area over the masseter and anterior temporalis muscles was divided into 15 subareas on each side (n=780). This investigation consisted of three steps. The first step involved thermographic facial examination, using lateral views. The second step involved the pressure pain threshold (PPT), marking the MTP pattern areas for referred pain (n=131) and local pain (n=282) with a coloured pencil, and a photograph of the lateral face with the head in the same position as the infrared imaging. The last step was the fusion of these two images, using dedicated software (Reporter® 8.5-SP3 Professional Edition and QuickReport® 1.2, FLIR Systems, Wilsonville, OR); and the calculation of the temperature of each point. RESULTS: PPT levels measured at the points of referred pain in MTPs (1.28±0.45 kgf) were significantly lower than the points of local pain in MTPs (1.73±0.59 kgf; p<0.05). Infrared imaging indicated differences between referred and local pain in MTPs of 0.5 °C (p<0.05). Analysis of the correlation between the PPT and infrared imaging was done using the Spearman non-parametric method, in which the correlations were positive and moderate (0.4≤r<0.7). The sensitivity and specificity in MTPs were 62.5% and 71.3%, respectively, for referred pain, and 43.6% and 60.6%, respectively, for local pain. CONCLUSION: Infrared imaging measurements can provide a useful, non-invasive and non-ionizing examination for diagnosis of MTPs in masticatory muscles.

Characteristics of referred muscle pain to the head from active trigger points in women with myofascial temporomandibular pain and fibromyalgia syndrome.

Our aim was to compare the differences in the prevalence and the anatomical localization of referred pain areas of active trigger points (TrPs) between women with myofascial temporomandibular disorder (TMD) or fibromyalgia (FMS). Twenty women (age 46 ± 8 years) with TMD and 20 (age 48 ± 6 years) with FMS were recruited from specialized clinic. Bilateral temporalis, masseter, sternocleidomastoid, upper trapezius, and suboccipital muscles were examined for TrPs. TrPs were identified by palpation and considered active when the pain reproduced familiar pain symptom experienced by the patient. The referred pain areas were drawn on anatomical maps, digitalized and also measured. A new analysis technique based on a center of gravity (COG) method was used to quantitative estimate of the localization of the TrP referred pain areas. Women with FMS exhibited larger areas of usual pain symptoms than women with myofascial TMD (P < 0.001). The COG coordinates of the usual pain on the frontal and posterior pain maps were located more superior in TMD than in FMS. The number of active TrPs was significantly higher in TMD (mean ± SD 6 ± 1) than in FMS (4 ± 1) (P = 0.002). Women with TMD exhibited more active TrPs in the temporalis and masseter muscles than FMS (P < 0.01). Women with FMS had larger referred pain areas than those with TMD for sternocleidomastoid and suboccipital muscles (P < 0.001). Significant differences within COG coordinates of TrP referred pain areas were found in TMD, the referred pain was more pronounced in the orofacial region, whereas the referred pain in FMS was more pronounced in the cervical spine. This study showed that the referred pain elicited from active TrPs shared similar patterns as usual pain symptoms in women with TMD or FMS, but that distinct differences in TrP prevalence and location of the referred pain areas could be observed. Differences in location of referred pain areas may help clinicians to determine the most relevant TrPs for each pain syndrome in spite of overlaps in pain areas.