Phantom Limb Neuroplasticity and Maladaptive Sensory Perceptions: Why Phantom Limb Paresthesia Should Be Integrated into Referred Pain Discussions.

The concept of referred pain is an integral part of the anatomy didactic content taught and discussed in all medical school curricula.  However, this discussion has excluded the topic of phantom limb pain, despite the existence of parallels in neurophysiological explanations between these conditions. This brief viewpoint attempts to reason why phantom limb paresthesia or pain should be included in the fold of refereed pain discussions.

Differential Activation of Colonic Afferents and Dorsal Horn Neurons Underlie Stress-Induced and Comorbid Visceral Hypersensitivity in Female Rats.

Chronic Overlapping Pain Conditions, including irritable bowel syndrome (IBS) and temporomandibular disorder (TMD), represent a group of idiopathic pain conditions that likely have peripheral and central mechanisms contributing to their pathology, but are poorly understood. These conditions are exacerbated by stress and have a female predominance. The presence of one condition predicts the presence or development of additional conditions, making this a significant pain management problem. The current study was designed to determine if the duration and magnitude of peripheral sensitization and spinal central sensitization differs between restraint stress-induced visceral hypersensitivity (SIH) and chronic comorbid pain hypersensitivity (CPH; stress during pre-existing orofacial pain). SIH in female rats, as determined by the visceromotor response, persisted at least four but resolved by seven weeks. In contrast, CPH persisted at least seven weeks. Surprisingly, colonic afferents in both SIH and CPH rats were sensitized at seven weeks. CPH rats also had referred pain through seven weeks, but locally anesthetizing the colon only attenuated the referred pain through four weeks, suggesting a transition to colonic afferent independent central sensitization. Different phenotypes of dorsal horn neurons were sensitized in the CPH rats seven weeks post stress compared to four weeks or SIH rats. The current study suggests differential processing of colonic afferent input to the lumbosacral spinal cord contributes to visceral hypersensitivity during comorbid chronic pain conditions. PERSPECTIVE: Chronic Overlapping Pain Conditions represent a unique challenge in pain management. The diverse nature of peripheral organs hinders a clear understanding of underlying mechanisms accounting for the comorbidity. This study highlights a mismatch between the condition-dependent behavior and peripheral and spinal mechanisms that contribute to visceral pain hypersensitivity.

The receptive field for visceral pain referred orofacially by the vagus nerves.

BACKGROUND: The nociceptive receptive field of the vagus nerves in animals includes virtually the entire thoracic, abdominal and laryngopharyngeal regions. However, the role of the vagus nerves in the transmission of visceral pain in humans, with the exception of pain from coronary artery diseases, is believed to be insignificant. AIM: The purpose of this report is to map out the clinical visceral pain receptive field of the vagus nerves relative to its nociceptive counterpart in animals. MATERIALS AND METHODS: The PubMed database and PMC were searched for case reports of patients with orofacial pain believed by the author(s) of the article to be referred from underlying non-cardiac thoracic, laryngopharyngeal or abdominal diseases. Reports of diseases for which non-neural explanations for the orofacial spread of pain were suggested were excluded. RESULTS: A total of 52 case reports of jaw pain and/or otalgia referred from laryngopharyngeal and noncardiac thoracic sources were discovered. In addition, a multicenter prospective study found that 25.8% of more than 3,000 patients with thoracic aortic dissection experienced pain in the head and neck region. In stark contrast, no case reports of orofacially referred pain from abdominal diseases were found. DISCUSSION: The results indicate that the laryngopharyngeal and thoracic portions of the vagal receptive field are capable of referring pain orofacially while the abdominal portion is not. The roles of the somatotopic organization of the trigeminal sub nucleus caudalis and neuromodulation in this referral of pain were discussed. CONCLUSION: Referred orofacial pain can lead to delayed diagnosis and poorer outcome in visceral diseases.

Disturbance of somatotopic spatial cognition and extra-territorial pain in carpal tunnel syndrome.

BACKGROUND: Several studies on carpal tunnel syndrome have reported pain that exists beyond the median nerve territory of the affected hand. However, the mechanism is unknown. PURPOSE: We investigated the cause of extra-territorial pain by the analysis of clinical assessments and cortical activity using magnetoencephalography. METHODS: To compare patients with and without extra-territorial pain, fourteen patients with carpal tunnel syndrome were assessed using clinical examination, such as patients' profile, paresthesia, physical tests, and psychological tests. The physical assessment included tactile threshold and static and moving two-point discrimination sensations on digital pulp. Neural activation in the cerebral cortex was also measured using z-scores calculated by magnetoencephalography. RESULTS: Among fourteen patients, ten patients had pain in the affected median nerve territory only and four patients had extra-territorial pain. When comparing the groups, the static and moving two-point discrimination sensation values in patients with extra-territorial pain were larger than those of patients without the pain (p < 0.05). The supra-marginal gyrus, mid-part of the precentral sulcus, angular gyrus in the left hemisphere, bilateral sensorimotor areas for legs, and bilateral isthmus-cingulate areas showed larger z-scores in patients with extra-territorial pain than in patients without the pain (p < 0.05). CONCLUSIONS: The static and moving two-point discrimination sensations signify the ability of tactile spatial acuity. Bilateral sensorimotor areas were activated in sites that were not the hand. Furthermore, the inferior parietal lobule in the left hemisphere, which synthesizes and integrates multiple sensations showed high activation. Our findings suggested that the mechanism of extra-territorial pain was associated with dysfunction of spatial cognition.

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.

Widespread Pressure Pain Sensitivity and Referred Pain from Trigger Points in Patients with Upper Thoracic Spine Pain.

OBJECTIVES: The presence of trigger points (MTrPs) and pressure pain sensitivity has been well documented in subjects with neck and back pain; however, it has yet to be examined in people with upper thoracic spine pain. The purpose of this study was to investigate the presence of MTrPs and mechanical pain sensitivity in individuals with upper thoracic spine pain. METHODS: Seventeen subjects with upper thoracic spine pain and 17 pain-free controls without spine pain participated. MTrPs were examined bilaterally in the upper trapezius, rhomboid, iliocostalis thoracic, levator scapulae, infraspinatus, and anterior and middle scalene muscles. Pressure pain thresholds (PPTs) were assessed over T2, the C5-C6 zygapophyseal joint, the second metacarpal, and the tibialis anterior. RESULTS: The numbers of MTrPs between both groups were significantly different (P < 0.001) between patients and controls. The number of MTrPs for each patient with upper thoracic spine pain was 12.4 ± 2.8 (5.7 ± 4.0 active TrPs, 6.7 ± 3.4 latent TrPs). The distribution of MTrPs was significantly different between groups, and active MTrPs within the rhomboid (75%), anterior scalene (65%), and middle scalene (47%) were the most prevalent in patients with upper thoracic spine pain. A higher number of active MTrPs was associated with greater pain intensity and longer duration of pain history. CONCLUSIONS: This study identified active MTrPs and widespread pain hypersensitivity in subjects with upper thoracic spine pain compared with asymptomatic people. Identifying proper treatment strategies might be able to reduce pain and improve function in individuals with upper thoracic spine pain. However, future studies are needed to examine this.

Trigger Points, Pressure Pain Hyperalgesia, and Mechanosensitivity of Neural Tissue in Women with Chronic Pelvic Pain.

Objectives: This study aims to evaluate the presence of myofascial trigger points (TrPs), widespread pressure pain sensitivity, and mechanosensitivity of neural tissue in women with chronic pelvic pain. Design: Case-control study. Setting: Faculty of Health Sciences. Subjects: Forty women with chronic pelvic pain between age 18 and 60 years and 40 matched healthy controls were included in the study. Methods: TrPs were bilaterally explored in gluteus maximus, gluteus medius, gluteus minimus, quadratus lumborum, and adductor magnus muscles. The referred pain reproduced lumbopelvic symptoms. Pressure pain thresholds (PPTs) were also bilaterally assessed over the Pfannenstiel incision point on the abdominal, C5-C6 zygapophyseal joint, second metacarpal, and tibialis anterior muscle. Mechanosensitivity of neural tissue was assessed with the neurodynamics tests of slump and the straight-leg raising. Results: Significant between-group differences were found in TrP presence in patients with chronic pelvic pain (P < 0.001) compared with those included in the control group. Widespread pressure pain hyperalgesia was also found, with PPTs significantly reduced in the points assessed. Neurodynamics show a significantly decreased value in women with CPP. Conclusions: Patients with chronic pelvic pain presented a high percentage of TrPs that reproduce their symptoms. Patients also showed a widespread pressure pain hyperalgesia and more mechanosensitive neural tissue due to a decrease on the range of motion related to neurodynamics.

Abdominal skeletal muscle activity precedes spontaneous menstrual cramping pain in primary dysmenorrhea.

BACKGROUND: Dysmenorrhea is a pervasive pain condition that affects 20-50% of reproductive-aged women. Distension of a visceral organ, such as the uterus, could elicit a visceromotor reflex, resulting in involuntary skeletal muscle activity and referred pain. Although referred abdominal pain mechanisms can contribute to visceral pain, the role of abdominal muscle activity has not yet been investigated within the context of menstrual pain. OBJECTIVE: The goal of this study was to determine whether involuntary abdominal muscle activity precedes spontaneous episodes of menstrual cramping pain in dysmenorrheic women and whether naproxen administration affects abdominal muscle activity. STUDY DESIGN: Abdominal electromyography activity was recorded from women with severe dysmenorrhea (n = 38) and healthy controls (n = 10) during menses. Simultaneously, pain was measured in real time using a squeeze bulb or visual analog rheostat. Ninety minutes after naproxen administration, abdominal electromyography activity and menstrual pain were reassessed. As an additional control, women were also recorded off menses, and data were analyzed in relation to random bulb squeezes. Because it is unknown whether mechanisms of menstrual cramps are different in primary or secondary dysmenorrhea/chronic pelvic pain, the relationship between medical history and abdominal muscle activity was examined. To further examine differences in nociceptive mechanisms, pressure pain thresholds were also measured to evaluate changes in widespread pain sensitivity. RESULTS: Abdominal muscle activity related to random-bulb squeezing was rarely observed in healthy controls on menses (0.9 ± 0.6 episodes/hour) and in dysmenorrhea participants off menses (2.3 ± 0.6 episodes/hour). In dysmenorrheic participants during menses, abdominal muscle activity frequently preceded bulb squeezing indicative of menstrual cramping pain (10.8 ± 3.0 episodes/hour; P < .004). Whereas 45% of the women with dysmenorrhea (17 of 38) had episodes of abdominal muscle activity associated pain, only 13% (5 of 38) had episodes after naproxen (P = .011). Women with the abdominal muscle activity-associated pain were less likely to have a diagnosis for secondary dysmenorrhea or chronic pelvic pain (2 of 17) than women without this pain phenotype (10 of 21; P = .034). Similarly, women with the abdominal muscle activity-associated pain phenotype had less nonmenstrual pain days per month (0.6 ± 0.5) than women without the phenotype (12.4 ± 0.3; P = .002). Women with abdominal muscle activity-associated pain had pressure pain thresholds (22.4 ± 3.0 N) comparable with healthy controls (22.2 ± 3.0 N; P = .967). In contrast, women without abdominal muscle activity-associated pain had lower pressure pain thresholds (16.1 ± 1.9 N; P = .039). CONCLUSION: Abdominal muscle activity may contribute to cramping pain in primary dysmenorrhea but is resolvable with naproxen. Dysmenorrheic patients without cramp-associated abdominal muscle activity exhibit widespread pain sensitivity (lower pressure pain thresholds) and are more likely to also have a chronic pain diagnosis, suggesting their cramps are linked to changes in central pain processes. This preliminary study suggests new tools to phenotype menstrual pain and supports the hypothesis that multiple distinct mechanisms may contribute to dysmenorrhea.

Experimental Referred Pain Extends Toward Previously Injured Location: An Explorative Study.

Facilitated pain mechanisms have been demonstrated in musculoskeletal pain, but it is unclear whether a recent painful injury leaves the pain system sensitized. Pain characteristics were assessed in individuals who recently recovered from ankle pain (recovered pain group; n = 25) and sex-matched control subjects (n = 25) in response to tonic pressure pain and saline-induced pain applied at the shin muscle. Pain intensity and pain referral patterns were recorded bilaterally after the painful muscle stimulus. Pressure pain thresholds were measured at the lower legs and shoulder. Cuff pressure algometry on the lower leg was used to assess pain detection threshold, pressure evoking 6-cm pain score on a 10-cm visual analog scale, pain tolerance, temporal summation of pain, and conditioned pain modulation. Compared with in control subjects, saline-induced and pressure-induced pain in the shin muscle were more frequently felt as referred pain in the previously painful ankle (P < .05), and the pain area within the previously affected ankle was larger after saline-induced pain (P < .05). In the recovered pain group, conditioned pain modulation responses and the cuff pressure needed to reach a 6-cm pain score on a 10-cm visual analog scale was higher in the previously painful leg compared with in the contralateral leg (P < .05). No group differences were found in pressure pain threshold, pain detection threshold, pain tolerance, and temporal summation of pain. PERSPECTIVE: These explorative findings demonstrate that pain mechanisms responsible for pain location may be reorganized and continue to be facilitated despite recovery. A large prospective study is needed to clarify the time profile and functional relevance of such prolonged facilitation in the pain system for understanding recurring pain conditions.

Pressure-induced referred pain areas are more expansive in individuals with a recovered fracture.

Musculoskeletal trauma and pain can sensitize central pain mechanisms, but whether these normalize on recovery is unknown. This study compared the extent of pain referral in individuals recovered from a musculoskeletal trauma and healthy controls. Twenty pain-free participants recovered from a shoulder fracture and 20 age-/sex-matched controls participated in 2 experimental sessions (day-0 and day-1) separated by 24 hours. On both days, pressure pain thresholds were measured bilaterally at infraspinatus, supraspinatus, trapezius, and gastrocnemius muscles. Referred pain towards the shoulder region was induced by a 60-second pressure stimulation (pressure pain threshold + 20%) at the infraspinatus muscle and recorded on an electronic body chart. After day-0 assessments, delayed onset muscle soreness (DOMS) was induced to challenge the pain systems by exercising the external rotators of the recovered/dominant shoulder. The size of pressure-induced pain referral on day-0 did not differ between groups, although there was a tendency for a smaller referred pain area in recovered group. Pressure pain thresholds at the infraspinatus muscle on the DOMS side were reduced on day-1 in both groups (P = 0.03). An expansion of pressure-induced pain referral was found in both groups following the DOMS protocol on day-1 (P = 0.05) with a relatively larger expansion (P = 0.05) and higher frequency of pain in the shoulder (P = 0.04) in the recovered pain group. After complete recovery and absence of pain symptoms after a fracture, central pain mechanisms seem to normalize in the region of the trauma after recovery but when sensitized a heightened response can emerge. Such mechanisms could be important for recurrence of pain conditions.

Referred cramping phantom hand pain elicited in the face and eliminated by peripheral nerve block.

Phantom limb pain is a restricting condition for a substantial number of amputees with quite different characteristics of pain. Here, we report on a forearm amputee with constant phantom pain in the hand, in whom we could regularly elicit the rare phenomenon of referred cramping phantom pain by touching the face. To clarify the underlying mechanisms, we followed the cramp during the course of an axillary blockade of the brachial plexus. During the blockade, both phantom pain and the referred cramp were abolished, while a referred sensation of "being touched at the phantom" persisted. Furthermore, to identify the cortical substrate, we elicited the cramp during functional magnetic imaging. Imaging revealed that referred cramping phantom limb pain was associated with brain activation of the hand representation in the primary sensorimotor cortex. The results support the hypothesis that referred cramping phantom limb pain in this case is associated with a substantial brain activation in the hand area of the deafferented sensorimotor cortex. However, this alone is not sufficient to elicit referred cramping phantom limb pain. Peripheral inputs, both, from the arm nerves affected by the amputation and from the skin in the face at which the referred cramp is evoked, are a precondition for referred cramping phantom limb pain to occur, at least in this case.

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.

Prospective, Randomized, Double-Blind, Placebo-Controlled Clinical Trial Assessing the Effects of Applying a Force to C5 by a Mechanically Assisted Instrument on Referred Pain to the Shoulder.

STUDY DESIGN: Randomized, prospective, double-blind, placebo-controlled clinical trial. OBJECTIVE: To determine the effects of applying a force to C5 of the spine by a mechanically assisted instrument (MAI) in patients with referred shoulder pain. SUMMARY OF BACKGROUND DATA: Manipulating C5 of the spine is a chiropractic treatment for referred shoulder pain; there are no clinical trials evaluating its efficacy. Outcome measures were patient ranked questionnaires and independent examiner findings. One hundred and twenty-five patients were diagnosed with referred shoulder pain of cervical origin; 65 patients were in the treatment cohort and 60 patients in the placebo cohort. METHODS: This was a prospective, randomized, double-blind, placebo-controlled trial assessing the effects of applying a force to C5 by a MAI to patients with referred shoulder pain. The treatment cohort had the MAI set at the maximum setting to transmit a force into the spine; the placebo cohort had the MAI turned off. Primary outcome measures were frequency and severity of extreme shoulder pain obtained via a patient-reported questionnaire; secondary outcome measures were patient ranked pain and functional outcomes as well as examiner assessed range of motion and strength. Assessment procedures were completed at 24 weeks posttreatment and data were analyzed with intent-to-treat protocol. RESULTS: There was a reduction in the frequency but not severity of extreme shoulder pain in the treatment cohort, average ranking reducing from weekly to monthly (P < 0.05). Patients treated with the MAI had 10 N (P = 0.04) better internal rotation strength after 6 months posttreatment. No differences with any other outcome measures between the two cohorts at the 24-week study period. CONCLUSION: The major effect of applying a MAI to the level of C5 of the spine in referred shoulder pain is improved shoulder strength for internal rotation in this randomized double-blinded clinical trial. LEVEL OF EVIDENCE: 2.

A critical overview of the current myofascial pain literature - October 2017.

In this overview of the myofascial pain literature, we have included several original contributions ranging from a study by Bowen and colleagues of trigger points in horses to the introduction of a new clinical entity of "laryngeal muscle myofascial pain syndrome in dysphonic patients." Minerbi and colleagues described for the first time the referred pain patterns of the longus colli muscle, while Casale and associates studied the spinal modulatory action of dry needling or acupuncture stimulation. Many dry needling articles are included in this overview with several recent outcome studies. Slowly, there is increasing scientific support for using dry needling for a variety of conditions. Several researchers explored specific aspects of dry needling, such as needle placements, whether eliciting a local twitch response is desired, and the role of psychological factors in post-needling soreness. Contributions originated in Australia, Belgium, Brazil, Canada, China, Germany, Greece, India, Israel, Italy, Korea, Portugal, Spain, Switzerland, Turkey, the UK, and the USA.

Adolescent idiopathic scoliosis: The Tethered Spine III: Is fascial spiral the key?

This article reports on an observational and treatment case series involving 22 adolescents and preadolescents treated over a 15 year period who had or appeared to be developing idiopathic scoliosis (IS). Common patterns of muscle and fascial asymmetry were observed and treated. Most of these individuals had spinal area pain and the trigger points (TrPs) apparently responsible for this pain were located in muscles at some distance from the spine, yet referred pain to locations throughout the thoracolumbar spine. Asymmetries in tension in these muscles appear to tether the spine in such a way as to contribute to scoliotic curvatures. The most common pattern of asymmetrical muscle tension found in these individuals follows a particular spiral fascial plane and as the fascia in this spiral plane tightened, the scoliotic curvature appeared to increase. Evaluation also showed that 21 of 22 of these individuals have major ligamentous laxity and this may also have contributed to the development of scoliotic curvatures. Furthermore, each of these individuals has marked overpronation of the ankles, with arches that totally collapse when weight-bearing. Based on observation during the care of these 22 subjects, it appears that asymmetry in the degree of pronation may, in some individuals, be a contributing factor in the development of the spiral body organization involved in the development of scoliosis. Common patterns of joint dysfunction were also observed in many of these individuals. There were also some findings of significant muscle weaknesses that appeared to contribute to the development of the spiraling body organization. Treatment of the tethering of the spine from myofascial asymmetries and related joint dysfunction not only resulted in elimination of pain in almost all cases but also, in many cases resulted in significant reduction of scoliotic curvatures including reductions of rib humps. In other cases, it resulted in stabilization of scoliotic curvatures, and in some cases it may have slowed the rate of progression of curvatures. Stretching and strengthening exercises appeared to contribute to the stability of treatment gains. A segment of the treated population had atypical scoliotic curvatures that did not follow the typical spiral pattern. Even in these individuals, there were significant patterns of fascial restriction and joint dysfunction accompanying the curvatures. Prior traumatic injury was a common factor in almost all of these atypical cases. Treatment of myofascial TrPs and asymmetrical fascial tension and accompanying joint dysfunction is proposed as a useful approach to treating pain in adolescents who have or who appear to be developing scoliosis and to treating and controlling and/or decreasing many scoliotic curvatures. This case series is presented as a way to illuminate possible factors in the development of scoliosis and promising treatment strategies to address these factors and to eliminate pain and stabilize or decrease curvatures so that further research can more systematically evaluate the role of these factors. An addendum of two more cases is also included, because of the information that these cases add to the discussion and to treatment approaches. Including the addendum cases, 8 of the subjects had scoliosis as documented by x-rays. The other 16 appeared to be developing scoliosis according to criteria stated below.

Experimental pain in the groin may refer into the lower abdomen: Implications to clinical assessments.

OBJECTIVES: To investigate the effects of experimental adductor pain on the pain referral pattern, mechanical sensitivity and muscle activity during common clinical tests. DESIGN: Repeated-measures design. METHODS: In two separate sessions, 15 healthy males received a hypertonic (painful) and isotonic (control) saline injection to either the adductor longus (AL) tendon to produce experimental groin pain or into the rectus femoris (RF) tendon as a painful control. Pain intensity was recorded on a visual analogue scale (VAS) with pain distribution indicated on body maps. Pressure pain thresholds (PPT) were assessed bilaterally in the groin area. Electromyography (EMG) of relevant muscles was recorded during six provocation tests. PPT and EMG assessment were measured before, during and after experimental pain. RESULTS: Hypertonic saline induced higher VAS scores than isotonic saline (p<0.001), and a local pain distribution in 80% of participants. A proximal pain referral to the lower abdominal region in 33% (AL) and 7% (RF) of participants. Experimental pain (AL and RF) did not significantly alter PPT values or the EMG amplitude in groin or trunk muscles during provocation tests when forces were matched with baseline. CONCLUSIONS: This study demonstrates that AL tendon pain was distributed locally in the majority of participants but may refer to the lower abdomen. Experimental adductor pain did not significantly alter the mechanical sensitivity or muscle activity patterns.

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.

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.