Prevalence and characteristics of referred pain in patients diagnosed with temporomandibular disorders according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) in Sharjah, United Arab Emirates.

BACKGROUND: Referred pain often complicates and delays the diagnosis of temporomandibular disorders (TMD). Elaborating the prevalence and characteristics of TMD-associated referred pain as well as the distribution of referred pain in different TMD classes will significantly improve the diagnostic process. The objectives of the present study were to assess the prevalence and to evaluate the characteristics of referred pain associated with TMD diagnosed according to the DC/TMD. METHODS: A total of 252 patients were evaluated using the DC/TMD Axes-I and -II assessment tools. Different modalities were used to treat the diagnosed TMD. Referred pain was diagnosed when the location of the perceived pain in response to palpation extended beyond the boundary of the structure that was examined. For pain locations that were perceived as deep, patients were asked to locate the surface of the area of pain. The result of the assessment was identified as positive if the patient described his perceived pain during the clinical examination as being familiar pain that was experienced in the same location in the last 30 days.  Results: TMD-associated referred pain was recorded in 153 patients (60.7%). The most common referred pain location was the temporal area (45.2%), followed by the ear (42.1%). The referred pain was recorded in disc displacement with reduction with intermittent locking and myofascial pain with referral in all patients (100%). The proportion of patients with referred pain was significantly different between the different TMD diagnostic subgroups (P < 0.001).  The recorded percentage of improvement in the referred pain following the treatment was 50.41% after 3 months and 56.65% after 6 months. CONCLUSIONS: Referred pain is a prominent feature of TMD. More studies are required with longer follow-up periods and bigger sample sizes to support the findings of the present study.

Pressure-Induced Referred Pain as a Biomarker of Pain Sensitivity in Fibromyalgia.

BACKGROUND: Fibromyalgia (FM) syndrome is characterized by widespread pain, fatigue, and generalized increased pain sensitivity. Appropriate and simple pain models are methods employed to assess pain mechanisms that can potentially lead to improved treatments. Pressure pain thresholds (PPTs) or mapping the referred pain area produced by pressure stimulation at suprathreshold intensities are used to assess pain mechanisms. The optimal suprathreshold stimulation intensity to elicit referred pain with minimal discomfort for patients with FM has yet to be determined. OBJECTIVES: The aim of this study was to compare the area and intensity of pressure-induced referred pain in patients with FM as elicited by systematic increases in PPTs, compared with controls. STUDY DESIGN: Observational, crossed-section study. SETTING: Research laboratory. METHODS: Twenty-six patients with FM and 26 healthy controls, age- and gender-matched, were included. Suprathreshold stimulation was applied to the infraspinatus muscle of the dominant side at 4 different intensities (PPT +20%, +30%, +40%, and +50%), after which referred pain was evaluated by measuring the area of pain in pixels using a digital body chart and its intensity on a Visual Analog Scale. Factors related to anxiety condition, pain catastrophizing, depression, and quality of life were recorded. RESULTS: The referred pain areas were larger in the FM group compared with healthy individuals at 120% (P = 0.024), 130% (P = 0.001), 140% (P = 0.001), and 150% (P = 0.001) PPT, however, within the FM group no differences were found between the intensity of suprathreshold stimulation and the size of the referred pain areas (P = 0.135) or pain intensity (P > 0.05). There was a positive correlation between the size of referred pain areas and pain catastrophizing in the FM group (r = 0.457, P = 0.032). LIMITATIONS: This study presents some limitations, among which is the variability found in the referred pain areas. CONCLUSIONS: These findings show that referred pain induced by applying a suprathreshold pressure of 120% PPT can be a useful biomarker to assess sensitized pain mechanisms in patients suffering from FM. KEY WORDS: Referred pain, pain sensitivity, fibromyalgia, central sensitization, suprathreshold, pressure pain threshold, biomarker, facilitated pain mechanisms.

Tooth-Related Pain or Not?

Dental pain is the most common acute pain presenting in the orofacial region; however, chronic pain conditions are also frequent and include; temporomandibular joint disorders (TMDs), primary headaches (neurovascular pain), painful post-traumatic trigeminal neuropathy (PPTTN) and less commonly referred pain and idiopathic or centralized pain conditions. All of these conditions can mimic toothache and vice versa. Many of these conditions are comorbid with high levels of tension headache and migraine reported in patients with TMD; however, dentists remain unfamiliar with headaches and medics unfamiliar with toothache's multiple presentations. The anatomical complexity of the region, the potential exhaustive differential diagnoses and the multiple siloed training of specialties, leads to incorrect and delayed diagnosis and often results in patients undergoing inappropriate surgical and medical treatments. The continued inappropriate interventions may also complicate the later presentation of the patient with pain, by changing its phenotype, preventing a timely and correct diagnosis. Due to the variable presentation of toothache, which can mimic many different chronic pains including; episodic throbbing pain of migraine, the dull continuous pain of myofascial and arthrogenous TMDs or centralized facial pain, diagnosis can be complex. Neuralgic pain occurs in the dentition in health and with disease, mimicking conditions like PPTTN, trigeminal neuralgia (TN), and trigeminal autonomic cephalalgias (TACs), many patients are inappropriately diagnosed and treated, either by general medical practitioners assuming that the neuralgia is due to TN rather than more commonly presenting toothache or by a dentists or other surgeons continuing to treat TN or TACs with routine surgical care. Many patients are prescribed countless courses of antibiotics and undergo multiple surgical interventions simply as a result of poor education due to siloed specialty training. This must be addressed to improve patient safety.

[Correlation between referred pain distribution and acupoint sensitization in patients with intestinal diseases].

OBJECTIVE: To observe the correlation between referred pain distribution and acupoint sensitization in patients with intestinal diseases. METHODS: In clinical research, 443 patients from 8 hospitals were recruited, including the outpatients and inpatients of Crohn's disease (n=143), ulcerative colitis (n=108), chronic appendicitis (n=87) and other intestinal diseases (n=105). The site with tenderness on the body surface and the morphological changes of local skin were observed and recorded in the patients. Using a sensory tenderness instrument, the pain threshold at the sensitization point was measured in 60 patients with ulcerative colitis. In animal experiment, SD rats were used and divided into a enteritis group (n=8), in which the enteritis model were established, and a control group (n=3), in which no any intervention was given. After the injection of Evans blue (EB) at caudal vein, the blue exudation points on the body surface were observed and the distribution rule was analyzed statistically. RESULTS: The referred pain on the body surface in the patients with intestinal diseases was mainly located in the lower abdomen (93.9%, 416/443), the lumbar region (70.9%, 314/443) and the lower legs (33.0%, 146/443). The diameter of tenderness region was 1.5 to 2.5 cm. Compared with the region without sensitization, the pain threshold of the sensitization point in the patients with ulcerative colitis was reduced significantly (P<0.001). The referred pain on the body surface in the patients with appendicitis was located in the right lower abdomen (97.7%, 85/87), the waist and back (54.0%, 47/87) and the right lower limbs on the medial side (71.3%, 62/87). The tenderness region was 1 to 2 cm in diameter and was irregular in form. After modeling of enteritis in the rats, the EB exudation points were visible from T12 to L2. CONCLUSION: Intestinal diseases induce referred pain on the body surface where is the same as or adjacent to the location of the spinal segment corresponding to the affected intestinal section. These sensitization regions are related to the locations of acupoints.

Ruptured Appendicitis and Retrocecal Abscess Masquerading as Knee Pain in a Pediatric Patient: A Case Report.

BACKGROUND: Knee pain has a variety of etiologies in the pediatric population, including septic arthritis, osteomyelitis, fracture, ligamentous injury, and neoplasms. Extrinsic sources of knee pain may also be intra-abdominal, although abdominal pathology is much more likely to manifest as hip or proximal thigh musculature pain. CASE REPORT: A 5-year-old healthy male presented with atraumatic right knee pain, discomfort with weightbearing, fever, and elevated inflammatory laboratory markers. Physical examination and magnetic resonance imaging findings of the knee were benign, leading to low clinical suspicion for knee septic arthritis. Blood cultures were positive for a gastrointestinal organism, Granulicatella adiacens, suggesting abdominal pathology leading to referred pain. Ultrasound evaluation and computed tomography (CT) of the abdomen revealed a large abscess secondary to perforated appendicitis, which was treated with CT-guided drainage and i.v. antibiotics. The patient's musculoskeletal pain subsided with treatment of the appendicitis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Acute appendicitis may present as knee pain, with other signs and symptoms mimicking septic arthritis, such as fever, inability to bear weight, and elevated inflammatory markers. Considering an array of differential diagnoses in pediatric patients with apparent knee septic arthritis is crucial to prevent delay in diagnosis of alternative infectious sources.

Induced lumbosacral radicular symptom referral patterns: a descriptive study.

BACKGROUND CONTEXT: Lumbosacral radicular symptoms are commonly evaluated in clinical practice. Level-specific diagnosis is crucial for management. Clinical decisions are often made by correlating a patient's symptom distribution and imaging with sensory dermatomal maps. It is common for patients to describe non-dermatomal symptom patterns and for imaging to demonstrate pathology at levels not predicted by a dermatomal map. These observations suggest that the referred symptom distribution from lumbosacral nerve root provocation is different from dermatomal maps. This phenomenon has been demonstrated in the cervical spine but not in the lumbosacral spine. PURPOSE: The objective of this study was to characterize potential lumbosacral radicular symptom referral patterns induced during transforaminal epidural injections. STUDY DESIGN/SETTING: This is an observational descriptive study. PATIENT SAMPLE: The patient sample included 71 consecutive patients with lumbosacral radicular pain undergoing lumbosacral transforaminal epidural injections at an outpatient interventional spine practice. OUTCOME MEASURES: Each subject drew the location of provoked lumbosacral radicular symptoms on a pain diagram. MATERIALS AND METHODS: Seventy-one consecutive patients undergoing 125 fluoroscopically guided lumbosacral transforaminal epidural injections at an outpatient interventional spine practice were included in the study. The described location of provoked symptoms was recorded (1) after final needle positioning, (2) after injection of up to 0.5 mL of contrast solution, and (3) after injection of up to a 1 mL test dose of 1% lidocaine. Each subject drew the location of provoked symptoms on a diagram. The provoked symptom diagrams for each lumbosacral segmental level were combined to create composite nerve root, level-specific, symptom referral pattern maps. RESULTS: Of the 125 injections, 87 provoked referred symptoms and were included in the analysis. Thirty-eight injections did not provoke referred pain symptoms and were excluded from further analysis. Four nerve roots were tested at L1 and eight were tested at L2. Because of the small number of subjects, composite diagrams and statistical analysis were not completed for these levels. Eleven nerve roots were analyzed at L3, 28 at L4, 34 at L5, and 11 at S1. Composite symptom referral pattern maps were created for levels L3, L4, L5, and S1. Although the symptom distribution occasionally followed the expected dermatomal maps, most often the referral was outside of the patterns expected for each level. The most common symptom referral pattern for levels L3-S1 was the buttock, the posterior thigh, and the posterior calf. CONCLUSIONS: The level-specific provoked symptom distribution during lumbosacral transforaminal epidural injections is frequently different from that predicted by classic lumbosacral dermatomal maps. Referred pain to the buttock, the posterior thigh, or the posterior calf may come from L3, L4, L5, or S1 nerve root segmental irritation.

Exploration of Quantitative Sensory Testing in Latent Trigger Points and Referred Pain Areas.

OBJECTIVE: The objective of this study was to investigate somatosensory nerve fiber function by applying different quantitative sensory testing including thermal, mechanical, and vibration thresholds over latent trigger points (TrP) and in its associated referred pain area. METHODS: A total of 20 patients with unilateral latent TrPs in the extensor carpi radialis brevis were included. Warmth detection threshold (WDT), cold detection threshold (CDT) and heat/cold pain thresholds (HPT, CPT), mechanical detection (MDT) and pain (MPT) thresholds, vibration threshold (VT), and pressure pain thresholds (PPT) were blinded assessed over the TrP, in the referred pain area, and in the respective contralateral mirror areas. A multilevel mixed-model ANOVA with site (TrP, referred pain area) and side (real or contralateral) as within-patient factors and sex as between-patients factor was conducted. RESULTS: No significant differences for thermal detection (WDT, CDT) or thermal pain thresholds (HPT, CPT) were found (all, Ps>0.141). The assessments over the TrP area showed lower PPT and MDT compared with the mirror contralateral TrP area (P<0.05). MDT were higher (P=0.001) but PPT (P<0.001) and MPT (P=0.032) were lower over the TrP area and contralateral mirror point compared with their respectively referred pain areas. Finally, VT was higher over the TrP area than in the referred pain area and over both mirror contralateral points. DISCUSSION: Assessing sensory changes over latent myofascial TrPs reveal mechanical hyperesthesia, pressure pain hyperalgesia, and vibration hypoesthesia compared with a contralateral mirror area.

Clinical Decision-Making in Chronic Spine Pain: Dilemma of Image-Based Diagnosis of Degenerative Spine and Generation Mechanisms for Nociceptive, Radicular, and Referred Pain.

BACKGROUND: Spine-related pain is a complex heterogeneous condition. Excessive reliance on radiological imaging might lead to overdiagnosis of incidental asymptomatic spinal changes and unnecessary surgery. Approaches to the clinical management of spine pain should (1) identify pain generators, types, patterns, and mechanisms; (2) confirm clinical suspension with a diagnostic injection; and (3) ensure that treatment is aimed at controlling pain and improving patient function rather than image-based surgical success. METHOD: This case series (7 cases) discusses commonly seen clinical presentation of spine pain analytically, with illustrations of possible pain generators, mechanisms, pathways, and pain types. Each case discusses pain types and location (axial nociceptive, referred, and radicular neuropathic), generators (degenerated disc, herniated disc, facet joint, and sacroiliac joint), pathways (sinuvertebral ventral ramus and medial and lateral branches dorsal ramus), and radiculopathy versus radicular pain, elaborating on coccydynia and cervicogenic headaches, epimere versus hypomere muscle embryology, function, innervation, and role in spine-related pain. RESULTS: Multiple pain generators might coexist in the same patient causing mixed pain types and referral patterns with multiple mechanisms and pathways. History review, physical examination, and diagnostic injections are the mainstays of diagnosis. CONCLUSIONS: Image-detected spondylosis might be an asymptomatic process. Clinical presentation is related to stenosis or pain. The mechanism of pain is related to compression, inflammation, or microinstability. Spine pain can be nociceptive axial, neuropathic radicular, and/or referred pain. Although image findings are helpful in radicular neuropathic pain from disc herniation, they are unreliable in nociceptive pain, and correlation with clinical and diagnostic injections is mandatory.

Back Pain with Leg Pain.

PURPOSE OF REVIEW: The clinical diagnostic dilemma of low back pain that is associated with lower limb pain is very common. In relation to back pain that radiates to the leg, the International Association for the Study of Pain (IASP) states: "Pain in the lower limb should be described specifically as either referred pain or radicular pain. In cases of doubt no implication should be made and the pain should be described as pain in the lower limb." RECENT FINDINGS: Bogduks' editorial in the journal PAIN (2009) helps us to differentiate and define the terms somatic referred pain, radicular pain, and radiculopathy. In addition, there are other pathologies distal to the nerve root that could be relevant to patients with back pain and leg pain such as plexus and peripheral nerve involvement. Hence, the diagnosis of back pain with leg pain can still be challenging. In this article, we present a patient with back and leg pain. The patient appears to have a radicular pain syndrome, but has no neurological impairment and shows signs of myofascial involvement. Is there a single diagnosis or indeed two overlapping syndromes? The scope of our article encompasses the common diagnostic possibilities for this type of patient. A discussion of treatment is beyond the scope of this article and depends on the final diagnosis/diagnoses made.

Referred Pain Patterns of the Infraspinatus Muscle Elicited by Deep Dry Needling and Manual Palpation.

OBJECTIVES: To identify the most common referred pain (ReP) pattern of the infraspinatus myofascial trigger point (MTrP) and compare its coincidence with the original ReP pattern, to verify whether there are any significant differences by sex and types of technique and to determine the observed signs and symptoms evoked by deep dry needling (DDN) and manual palpation (MPal). DESIGN: A cohort study of patients randomized to two different examination methods (July and August 2016). SETTINGS: Students and staff recruited from Miguel Hernandez University (Southeast Spain). PATIENTS: One hundred thirty-three participants (70.7% women) with shoulder complaints were randomly assigned to either an MPal (n = 67) or DDN group (n = 66). INTERVENTIONS: The same physiotherapist carried out the techniques on all participants, and the same protocol was followed for both the DDN and MPal groups. The physiotherapist did not ask participants about their pain features or other relevant issues. OUTCOME MEASURES: Local twitch response (LTR) and ReP assessed through a visual analogue scale and features of ReP of the infraspinatus muscle. RESULTS: The areas with the highest percentage of ReP were the front (area 3; 27.1%) and back (area 11; 21.1%) of the arm, anterior (area 4; 36.1%) and posterior (area 12; 42.1%) shoulder, and infraspinatus muscle area. DDN proved to be significantly easier than MPal in evoking an LTR (p ≤ 0.001). There were significant differences between sexes in zone 2 (p = 0.041) and no statistically significant differences were found by technique. CONCLUSIONS: The ReP pattern of the infraspinatus muscle coincides with the original pattern described by Travell and Simons, although the neck area should be questioned. The study found no significant differences in the ReP pattern by sex and when comparing MPal with DDN of MTrP of the infraspinatus muscle. DDN proved to be significantly easier than MPal in evoking an LTR.

Iliocostalis Thoracis-Lumborum Myofascial Pain: Reviewing a Subgroup of a Prospective, Randomized, Blinded Trial. A Challenging Diagnosis with Clinical Implications.

BACKGROUND: Pain of myofascial origin is a well-recognized pathology characterized by the presence of two components: referred pain; which is often distant from its source and specific to each muscle, and the trigger point, a localized hyperirritable band present in the affected muscle and able to reproduce the referred pain when stimulated. Myofascial pain (MP) commonly coexists in patients with acute or chronic pain of other etiologies. The uniqueness of the clinical presentation of some MPs and the lack of training of most specialties represent a clinical challenge. Thus, many patients with MPS receive less than optimal management of this condition. OBJECTIVE: Pain at the anterior torso, originating at the posterior torso, can mimic common pathologies that correlate with the same anatomical area such as cardiac and intra-abdominal conditions. These clinical characteristics could be caused by MP of the iliocostalis thoracis-lumborum (ITL) muscle. However, this entity has not been well addressed in the medical literature. In this report we characterize the manifestations, diagnosis, and clinical implications of ITL MP. STUDY DESIGN: Observational assessment. SETTING: Two university-based academic emergency medicine departments (ED) in an urban setting in the United States. METHODS: A convenience sample of 43 patients who presented to the ED with pain at the anterior aspect of the torso (chest, abdomen, or pelvis) and clinical evidence of MP originated in the ITL muscle.Of a clinical trial of patients with MP, we describe a subgroup of patients with MP of the ITL which was clinically evident by the presence of a trigger point (TP) in its ability to reproduce the referred pain present at the anterior aspect of the torso. Patients received a TP injection. In this trial we intend to demonstrate that TP injections using particulate steroids mixed with a local are no more effective than saline alone to treat MP. The primary outcome was pain control (decrease in intensity of 50% or more below baseline numeric pain rating). A follow-up telephone interview was performed by third-party abstractors. RESULTS: Forty-three patients presented with pain of the anterior torso and ipsilateral back, both correlating with the level of the TP of the ITL muscle. The pain had been present from 2 days to 7 years. The most common locations of pain were the right-lower quadrant and the left side of the chest. In many of them a pattern of missed diagnosis was evident despite extensive workups and consultations. Only 17 patients were able to identify the precipitating event; the most common was coughing. Two weeks after TP injection, all patients still had satisfactory pain control. After treatment, no missed pathology or returns to the ED were reported. LIMITATIONS: This descriptive portion of the ongoing study does not affect the integrity of the trial itself but could be subject to the introduction of subject selection and selective reporting bias. Similarly, this convenience sample does not establish the incidence of this pathology and challenges the external validity to other clinical settings. CONCLUSIONS: Anterior torso pain often resulted in extensive workups before ITL myofascial pain was diagnosed. TP injections were diagnostic and therapeutic of ITL myofascial pain.

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.

Referred facial sensation on the hand after full face transplantation.

OBJECTIVE: Using a single patient case study, we aimed to look at the interaction between full face transplantation and subsequent somatosensory representation in the cortex. METHODS: We present a patient with full face transplantation who has recovered primary sensory modalities. The patient also has facial sensations such as touch perception in sensory examinations of the hands and fingers. RESULTS: fMRI findings show interactions between the cortical representations of the face and hand. CONCLUSION: This phenomenon is one of the well-known referred sensations and reveals how face transplantation relates to cortical plasticity.

The management of acute hip pain in the military: femoral neck stress fractures and tears of the acetabular labrum.

Acute hip pain is a common presenting complaint amongst the military population. It can present in a variety of ways, with a broad range of differential diagnoses to consider. Most cases of acute hip pain in military patients tend to be traumatic in origin. Pathology within the hip can be a diagnostic challenge, as symptoms often overlap between differential diagnoses and examination findings are not always sensitive or specific. Any hip injury will potentially downgrade a military patient and can also be a significant cause of long-term morbidity. Being able to manage the patient with acute hip pain effectively will ensure that patients spend less time in the diagnostic chain and reach the definitive treatment they require to continue to carry out their primary role. This paper describes how best to manage military patients who present with acute hip pain. It covers the diagnostic challenges faced by clinicians, the differential diagnoses of acute hip pain and describes the management of some common injuries of the hip: tears of the acetabular labrum and femoral neck stress fractures.

[Pseudo-radicular referred leg pain]. / Pseudoradikulärer/übertragener Beinschmerz.

Pseudo-radicular leg pain as initially described by Bruegger more than 55 years ago was at that time a genius explanation for so many non-radicular pain syndromes that needed not any kind of surgical intervention but in first line a manual treatment or a treatment by therapeutic local anesthetics. Today we describe this pain as a "referred pain" originating from other anatomic structures that may occur during the development of chronic pain. Nevertheless this pain is found in many patients and it still seems to be a big problem for many physicians and surgeons. Imaging does not help either. The history and the clinical symptoms, the examinations, the chain reactions in the motor system as well as the treatment options from the point of view of manual medicine are described.

Cancer and Referred Facial Pain.

Orofacial pain may be a symptom of diverse types of cancers as a result of local or distant tumor effects. The pain can be presented with the same characteristics as any other orofacial pain disorder, and this should be recognized by the clinician. Orofacial pain also can arise as a consequence of cancer therapy. In the present article, we review the mechanisms of cancer-associated facial pain, its clinical presentation, and cancer therapy associated with orofacial pain.