Analgesic effect of dance movement therapy: an fNIRS study.

OBJECTIVE: This study aims to explores the physiological and psychological mechanisms of exercise-induced hypoalgesia (EIH) by combining the behavioral results with neuroimaging data on changes oxy-hemoglobin (HbO) in prefrontal cortex (PFC). METHODS: A total of 97 healthy participants were recruited and randomly divided into three groups: a single dance movement therapy (DMT) group, a double DMT group, and control group. Evaluation indicators included the pressure pain threshold (PPT) test, the color-word stroop task (CWST) for wearing functional near-infrared spectroscopy (fNIRS), and the self-assessment manikin (SAM). The testing time is before intervention, after intervention, and one hour of sit rest after intervention. RESULTS: 1) Repeated measures ANOVA revealed that, there is a time * group effect on the PPT values of the three groups of participants at three time points. After 30 minutes of acute dance intervention, an increase in the PPT values of 10 test points occurred in the entire body of the participants in the experimental group with a significant difference than the control group. 2) In terms of fNIRS signals, bilateral DLPFC and left VLPFC channels were significantly activated in the experimental group. 3) DMT significantly awakened participants and brought about pleasant emotions, but cognitive improvement was insignificant. 4) Mediation effect analysis found that the change in HbO concentration in DLPFC may be a mediator in predicting the degree of improvement in pressure pain threshold through dance intervention (total effect ß = 0.7140). CONCLUSION: In healthy adults, DMT can produce a diffuse EIH effect on improving pressure pain threshold, emotional experience but only showing an improvement trend in cognitive performance. Dance intervention significantly activates the left ventrolateral and bilateral dorsolateral prefrontal cortex. This study explores the central nervous system mechanism of EIH from a physiological and psychological perspective.

Associations of pain sensitivity and conditioned pain modulation with physical activity: findings from the Multicenter Osteoarthritis Study (MOST).

OBJECTIVE: Individuals with chronic pain due to knee osteoarthritis (OA) are insufficiently physically active, and alterations of facilitatory and inhibitory nociceptive signaling are common in this population. Our objective was to examine the association of these alterations in nociceptive signaling with objective accelerometer-based measures of physical activity in a large observational cohort. DESIGN: We used data from the Multicenter Osteoarthritis Study. Measures of peripheral and central pain sensitivity included pressure pain threshold at the knee and mechanical temporal summation at the wrist, respectively. The presence of descending pain inhibition was assessed by conditioned pain modulation (CPM). Physical activity was quantitatively assessed over 7 days using a lower back-worn activity monitor. Summary metrics included steps/day, activity intensity, and sedentary time. Linear regression analyses were used to evaluate the association of pain sensitivity and the presence of descending pain inhibition with physical activity measures. RESULTS: Data from 1873 participants was analyzed (55.9% female, age = 62.8 ± 10.0 years). People having greater peripheral and central sensitivity showed lower step counts. CPM was not significantly related to any of the physical activity measures, and none of the exposures were significantly related to sedentary time. CONCLUSIONS: In this cohort, greater peripheral and central sensitivity were associated with reduced levels of objectively-assessed daily step counts. Further research may investigate ways to modify or treat heightened pain sensitivity as a means to increase physical activity in older adults with knee OA.

Effects of motor imagery using virtual reality on pain sensitivity and affect in healthy individuals: a prospective randomized crossover study.

OBJECTIVE: Exercise induces a hypoalgesic response and improves affect. However, some individuals are unable to exercise for various reasons. Motor imagery, involving kinesthetic and visual imagery without physical movement, activates brain regions associated with these benefits and could be an alternative for those unable to exercise. Virtual reality also enhances motor imagery performance because of its illusion and embodiment. Therefore, we examined the effects of motor imagery combined with virtual reality on pain sensitivity and affect in healthy individuals. DESIGN: Randomized crossover study. SETTING: Laboratory. SUBJECTS: Thirty-six participants (women: 18) were included. METHODS: Each participant completed three 10-min experimental sessions, comprising actual exercise, motor imagery only, and motor imagery combined with virtual reality. Hypoalgesic responses and affective improvement were assessed using the pressure-pain threshold and the Positive and Negative Affect Schedule, respectively. RESULTS: All interventions significantly increased the pressure-pain threshold at the thigh (P < .001). Motor imagery combined with virtual reality increased the pressure-pain threshold more than motor imagery alone, but the threshold was similar to that of actual exercise (both P ≥ .05). All interventions significantly decreased the negative affect of the Positive and Negative Affect Schedule (all P < .05). CONCLUSIONS: Motor imagery combined with virtual reality exerted hypoalgesic and affective-improvement effects similar to those of actual exercise. CLINICAL TRIALS REGISTRATION: The study was enrolled in the UMIN Clinical Trials Registry (registration number: UMIN000046095). The website for registration information is https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000052614.

Instrumental assessment of pressure pain threshold over trigeminal and extra-trigeminal area in people with episodic and chronic migraine: a cross-sectional observational study.

BACKGROUND: Central and peripheral sensitization are characterized by widespread hyperalgesia that is manifested by larger pain extent area and reduction in pressure pain threshold (PPT). PPT decreases in patients with migraine not only over the trigeminal cervical complex but also throughout the body. METHODS: A cross-sectional study was adopted to assess the local and widespread hyperalgesia in chronic and episodic migraine patients respect to healthy controls. The guidelines of Andersen's were used to evaluate the PPT bilaterally over 3 muscles in the trigemino-cervical complex (temporalis, sub-occipitalis, trapezius) and over 1 muscle far from this area (tensor fasciae latae). RESULTS: Thirty subjects with episodic migraine (35.8 ± 2.82 years), 30 with chronic migraine (53.03 ± 19.79 years), and 30 healthy controls (29.06 ± 14.03 years) were enrolled. The interaction effect was present for the trapezius muscle with a significant difference between the right and the left side in episodic group (p = 0.003). A group effect was highlighted in all four muscles analyzed such as suboccipital (p < 0.001), temporalis (p > 0.001), trapezius (p < 0.001), and TFL (p < 0.001). PPT was usually higher in the control group than in the episodic group which in turn was characterized by higher PPT values than the chronic group. CONCLUSIONS: People with chronic and episodic migraine presented lower PPT than healthy controls both in the trigeminal and in the extra-trigeminal area. People with chronic migraine presented lower PPT than episodic migraine only in the trigeminal area. Temporalis and sub-occipitalis are the most sensitive muscles in people with chronic and episodic migraine.

Immediate effect of extracorporeal shockwave therapy in patients with chronic non-specific low back pain: A randomised placebo-controlled triple-blind trial.

OBJECTIVE: To compare the immediate effects of shockwave therapy using two different tips in patients with chronic non-specific low back pain. DESIGN: Randomised placebo-controlled study with three intervention groups. SETTING: The patients recruited for this study were sent for physiotherapy treatment at primary care between May and July 2022. PARTICIPANTS: Eighty-one patients with chronic non-specific low back pain aged 18-80 years with pain for ≥3 months and pain intensity ≥3 were randomly recruited for the study. INTERVENTION: The patients received a single intervention of radial shockwave therapy with 2000 discharges at 100 mJ energy and 5 Hz frequency using concave or convex tips or placebo treatment. MAIN MEASURES: The primary outcome was pain intensity immediately post-intervention. The secondary outcomes were pressure pain threshold, temporal summation of pain, and functional performance. Data were collected at baseline and post-intervention. RESULTS: The post-intervention pain intensity in the concave tip group is an average of two points lower (95% CI = -3.6, -0.4; p < 0.01) than that in the placebo group. The post-intervention pressure pain threshold for the concave tip group was an average of 62.8 kPa higher (95% CI = 0.4, 125.1; p < 0.05) than for the convex tip group and 76.4 kPa higher (95% CI = 14, 138.7; p < 0.01) than in the placebo group. CONCLUSION: The concave tip shockwave therapy is effective in reducing pain and local hyperalgesia in patients with chronic non-specific low back pain.

Critical evaluation and recalculation of current systematic reviews with meta-analysis on the effects of acute and chronic stretching on passive properties and passive peak torque.

PURPOSE: Muscle, tendon, and muscle-tendon unit (MTU) stiffness as well as passive peak torque (PPT) or delayed stretching pain sensation are typical explanatory approaches for stretching adaptations. However, in literature, differences in the study inclusion, as well as applying meta-analytical models without accounting for intrastudy dependency of multiple and heteroscedasticity of data bias the current evidence. Furthermore, most of the recent analyses neglected to investigate PPT adaptations and further moderators. METHODS: The presented review used the recommended meta-analytical calculation method to investigate the effects of stretching on stiffness as well as on passive torque parameters using subgroup analyses for stretching types, stretching duration, and supervision. RESULTS: Chronic stretching reduced muscle stiffness ( - 0.38, p = 0.01) overall, and also for the supervised ( - 0.49, p = 0.004) and long static stretching interventions ( - 0.61, p < 0.001), while the unsupervised and short duration subgroups did not reach the level of significance (p = 0.21, 0.29). No effects were observed for tendon stiffness or for subgroups (e.g., long-stretching durations). Chronic PPT (0.55, p = 0.005) in end ROM increased. Only long-stretching durations sufficiently decreased muscle stiffness acutely. No effects could be observed for acute PPT. CONCLUSION: While partially in accordance with previous literature, the results underline the relevance of long-stretching durations when inducing changes in passive properties. Only four acute PPT in end ROM studies were eligible, while a large number were excluded as they provided mathematical models and/or lacked control conditions, calling for further randomized controlled trials on acute PPT effects.

Comparison of Dry Needling and Cold-Spray-Stretching Treatments by Ultrasonography and Electrophysiology: Prospective, Randomized Controlled Trial.

OBJECTIVES: To compare the efficacy of dry needling (DN) and cold-spray-stretching treatments using surface electromyography (sEMG) and ultrasound (US) in the treatment of patients with myofascial pain syndrome (MPS) with active trigger point (ATrP) in the upper trapezius muscle. METHODS: This prospective randomized single-blind study included 60 MPS patients aged 18-65 years who have ATrP in the upper trapezius muscle. Patients were randomized into two treatment groups as DN and cold spray stretching. Both treatment groups received 1 treatment per week and totally 3 sessions. Evaluation parameters were pain level assessed by Numeric Rating Scale and algometer, neck range of motion angles, neck disability index (NDI). The effects of the treatments on ATrP were evaluated by sEMG and US histogram. All parameters were evaluated at the beginning of the treatment and at the end. Algometer and sEMG were performed also before and after the first and third sessions. RESULTS: There was no significant difference between the two groups regarding demographic data. The mean age of the participants was 39.7 ± 11.6 years. Fifty-one patients were female. Significant improvement in terms of pain level, functionality, sEMG, and US histogram were achieved in both groups (P < .05). When comparing the two groups, algometer scores and the NDI score were statistically higher in the cold-spray-stretching group than in the DN group (P < .008 and P < .028, respectively). CONCLUSION: Both treatment options should be preferred. The efficacy of both treatments was observed via sEMG and US histograms.

Hypoalgesia after aerobic exercise in healthy subjects: A systematic review and meta-analysis.

Exercise-Induced Hypoalgesia (EIH) refers to an acute reduced pain perception after exercise. This systematic review and meta-analysis investigated the effect of a single aerobic exercise session on local and remote EIH in healthy individuals, examining the role of exercise duration, intensity, and modality. Pressure pain thresholds (PPT) are used as the main measure, applying the Cochrane risk of bias tool and GRADE approach for certainty of evidence assessment. Mean differences (MD; Newton/cm²) for EIH effects were analysed. Thirteen studies with 23 exercises and 14 control interventions are included (498 participants). Most studies used bicycling, with only two including running/walking and one including rowing. EIH occurred both locally (MD = 3.1) and remotely (MD = 1.8), with high-intensity exercise having the largest effect (local: MD = 7.5; remote: MD = 3.0) followed by moderate intensity (local: MD = 3.1; remote: MD = 3.0). Low-intensity exercise had minimal impact. Neither long nor short exercise duration induced EIH. Bicycling was found to be effective in eliciting EIH, in contrast to the limited research observed in other modalities. The overall evidence quality was moderate with many studies showing unclear risk biases.

Does subjective social status affect pain thresholds? - an experimental examination.

Past research regarding the relationship between different constructs of social status and different aspects of pain has yielded divergent results. So far, there are few experimental studies to investigate the causal relationship between social status and pain. Therefore, the present study aimed to examine the effect of perceived social status on pain thresholds by experimentally manipulating participants' subjective social status (SSS). 51 female undergraduates were randomly assigned to a low- or high-status condition. Participants' perceived social standing was temporarily elevated (high SSS condition) or reduced (low SSS condition). Before and after experimental manipulation participants' pressure pain thresholds were assessed. The manipulation check confirmed that participants in the low-status condition reported significantly lower SSS than participants in the high-status condition. A linear mixed model revealed a significant group x time interaction for pain thresholds: Whereas participants' pain thresholds in the low SSS condition increased post manipulation, pain thresholds of participants in the high SSS condition decreased post manipulation (ß = 0.22; 95% CI, 0.002 to 0.432; p < .05). Findings suggest that SSS may have a causal effect on pain thresholds. This effect could either be due to a change in pain perception or a change in pain expression. Future research is needed to determine the mediating factors.

Differences in the epidermal pain threshold between different needle puncture sites.

PURPOSE: Puncture of the skin by a needle, such as for peripheral nerve block or for intravenous or arterial catheter placement, may cause pain to the patient, so that analgesic method may be required to reduce pain caused by needle puncture. Nevertheless, there is little information as to which puncture sites are more painful than the other. METHODS: After obtaining an approval of the study by a research ethics committee and written informed consent from all the participants, we studied 30 volunteers to quantify pain threshold at 13 skin sites of the body, using an algometer. RESULTS: Compared with pain threshold at the cubital fossa (which was regarded as the control value), the relative pain threshold was significantly lower (with clinically meaningful difference) at the lateral carpus (median (interquartile range): 0.66 (0.56-0.73)) and the medial carpus (0.80 (0.73-0.94)); and was significantly higher (with clinically meaningful difference) at the olecranon (2.08 (1.93-2.42)), the forehead (1.59 (1.46-1.74)), the upper shoulder (1.52 (1.38-1.79)), and the dorsal shoulder (1.39 (1.18-1.55)). CONCLUSIONS: We conclude that there are significant differences in pain threshold between different puncture sites. Analgesic method before needle puncture may be required at the sites where the pain threshold is relatively low.

The effect of 6GHz radiofrequency electromagnetic radiation on rat pain perception.

This paper presents data on pain perception in rats exposed to 6 GHz radiofrequency electromagnetic radiation (RF-EMR). Rats were divided into two groups: control (n = 10, 4 replicates per test) and RF-EMR exposed group (n = 10, 4 replicates per test). Nociceptive responses of the groups were measured using rodent analgesiometry. Rats were divided into control and RF-EMR exposed groups. Nociceptive responses were measured using rodent analgesiometry. RF-EMR exposed rats had a 15% delay in responding to hot plate thermal stimulation compared to unexposed rats. The delay in responding to radiant heat thermal stimulation was 21%. We determined that RF-EMR promoted the occurrence of pressure pain as statistical significance by + 42% (p < 0.001). We observed that RF-EMR exposure increased nociceptive pain by + 35% by promoting cold plate stimulation (p < 0.05). RF-EMR exposure did not affect thermal preference as statistical significance but did support the formation of pressure pain perception.

In this study, we present data on pain perception in rats exposed to 6GHz RF-EMR. RF-EMR exposed rats showed delayed responses to hot plate and radiant heat thermal stimulation. RF-EMR increased pressure and nociceptive pain as statistically significance. In particular, the effects of RF-EMR should be considered when assessing hyperalgesic and hypoalgesic symptoms in the clinic. The results of this study indicate the need to take precautions against the possible negative effects of RF-EMR on human health with the rise of 5G technology.

Beyond the Self-Reports: A Review on Objective Pain Measurement and Its Implications.

Current methods of pain measurement are inadequate in capturing the complexity of the pain experience. This limitation arises mainly because these methods tend to overlook the multiple dimensions of pain during assessment, heavily relying on self-reported measures, which inherently have their drawbacks. Self-reported measures aim to gauge the pain severity experienced by an individual, based solely on their perception of the most intense pain sensation. However, these measures are prone to various biases and may not accurately reflect the actual pain experienced. To overcome these limitations, a new system of pain assessment is necessary, which minimizes subjective involvement and provides a more accurate representation of pain. The 'Pain Calculator' is a newly developed tool that has demonstrated promising accuracy in measuring somatic pain in the low back region. This tool effectively overcomes the subjective biases characteristic of the self-reported measures and provides a reliable and clinically feasible alternative to the existing pain assessment tools.

Effect of Remimazolam on Pain Perception and Opioid-Induced Hyperalgesia in Patients Undergoing Laparoscopic Urologic Surgery-A Prospective, Randomized, Controlled Study.

Background and Objectives: The effects of midazolam, a benzodiazepine, on pain perception are complex on both spinal and supraspinal levels. It is not yet known whether remimazolam clinically attenuates or worsens pain. The present study investigated the effect of intraoperative remimazolam on opioid-induced hyperalgesia (OIH) in patients undergoing general anesthesia. Materials and Methods: The patients were randomized into three groups: group RHR (6 mg/kg/h initial dose followed by 1 mg/kg/h remimazolam and 0.3 µg /kg/min remifentanil), group DHR (desflurane and 0.3 µg /kg/min remifentanil) or group DLR (desflurane and 0.05 µg/kg /min remifentanil). The primary outcome was a mechanical hyperalgesia threshold, while secondary outcomes included an area of hyperalgesia and clinically relevant pain outcomes. Results: Group RHR had a higher mechanical hyperalgesia threshold, a smaller hyperalgesia postoperative area at 24 h, a longer time to first rescue analgesia (p = 0.04), lower cumulative PCA volume containing morphine postoperatively consumed for 24 h (p < 0.01), and lower pain intensity for 12 h than group DHR (p < 0.001). However, there was no significant difference in OIH between groups RHR and DLR. Conclusions: Group RHR, which received remimazolam, attenuated OIH, including mechanically evoked pain and some clinically relevant pain outcomes caused by a high dose of remifentanil. Further research is essential to determine how clinically meaningful and important the small differences observed between the two groups are.

The Effects of Different Myofascial Release Techniques on Pain, Range of Motion, and Muscle Strength in Athletes With Iliotibial Band Tightness: A Randomized Controlled Study.

CONTEXT: We designed this study to investigate the effects of 2 myofascial release techniques, Instrument-Assisted Soft Tissue Mobilization (IASTM) and Foam Roller (FR), on pain, joint range of motion, and muscle strength in athletes suffering from iliotibial band (ITB) tightness. DESIGN: A total of 39 male soccer players were enrolled in this randomized controlled trial, aged between 18 and 23 years who were divided into 3 groups: Only Exercise, IASTM, and FR. METHODS: All participants performed daily strengthening and stretching exercises, while 1 group added IASTM, and the other added FR to the exercise program. We evaluated ITB tightness with the Ober test and an inclinometer, pressure pain threshold, using an algometer, and we evaluated muscle strength with the Cybex Norm Isokinetic device. RESULTS: We found that all 3 groups exhibited an increase in the Ober inclination angle after the interventions (P = .001), but the increase was greater for participants in the IASTM and FR groups, compared with exercise alone. Additionally, both the IASTM and FR groups displayed an increased pressure pain threshold (P = .001), whereas there was no change in the control group. Moreover, while all 3 groups experienced an increase in hip muscle strength (P = .001), the IASTM and FR groups exhibited a greater increase compared with exercise alone (P = .001). CONCLUSIONS: Based on these findings, exercise improves pain, range of motion, and muscle strength in athletes with ITB tightness, and IASTM, and FR techniques enhanced exercise effects but did not differ from one another. While our study demonstrated that both IASTM and FR techniques significantly enhance the benefits of exercise for athletes with ITB tightness, further research could delve into the long-term effects of these interventions.

Endogenous Sex Hormones Modulate the Analgesic Effect of Tramadol in Lean and High-Fat Diet-Induced Obese Wistar Rats: A Preclinical Molecular Approach.

INTRODUCTION: Differences in pain thresholds may have implications in pain management, as they may account in part for the variability in analgesic requirements between individuals. We planned to investigate the influence of endogenous sex hormones on the analgesic modulation of tramadol in lean and high-fat diet-induced obese Wistar rats. METHODS: The whole study was carried out on 48 adult Wistar rats (24 male: 12 obese and 12 lean and 24 female: 12 obese and 12 lean). Each male and female rat group was further subdivided into two groups (n = 6/group) and treated with normal saline/tramadol for 5 days. On the fifth day, 15 min after tramadol/normal saline treatment, animals were tested for pain perception toward noxious stimuli. Later, endogenous 17 beta-estradiol and free testosterone levels in serum were estimated through ELISA methods. RESULTS: The present study revealed that female rats experienced more pain sensitivity to noxious stimuli compared to male rats. High-fat diet-induced obese rats experienced more pain sensations to noxious stimuli than lean rats. Obese male rats were found to have significantly low free testosterone and high 17 beta-estradiol levels compared to lean male rats. An increase in serum 17 beta-estradiol level led to increased pain sensation to noxious stimuli. While an increase in free testosterone level resulted in the lowering of pain sensation to noxious stimuli. CONCLUSION: The analgesic effect of tramadol was more pronounced in male rats compared to female rats. The analgesic effect of tramadol was more marked in lean rats compared to obese rats. Additional research to elucidate obesity-induced endocrine changes and the mechanisms driving sex hormones in pain perception is needed to foster future interventions to reduce disparities in pain.

Evaluation of a scoring system for the detection of central sensitization among women with chronic pelvic pain.

BACKGROUND: Central sensitization is frequently associated with chronic pelvic pain and requires specific management. The pain is described as hypersensitivity to an innocuous stimulus that is both widespread and persistent. However, no study has evaluated if central sensitization can be measured objectively with neurophysiological tests in the pelvic and perineal area to prove this concept in women with chronic pelvic pain. OBJECTIVE: This study aimed to evaluate nociceptive thresholds (primary objective) and spatial and temporal diffusion of pain among women with chronic pelvic pain and high or low scores of central sensitization. STUDY DESIGN: This prospective, assessor-blinded, comparative study compared a cohort of women with chronic pelvic pain and a high (>5/10; n=29) vs low (<5/10; n=24) score of sensitization according to the Convergences PP criteria. Participants underwent a noninvasive bladder sensory test, a rectal barostat test, and a muscular (algometer) and a vulvar (vulvagesiometer) sensory test. Poststimulation pain (minutes), quality of life (Medical Outcomes Study 36-Item Short Form Survey), and psychological state, comprising anxiety (State-Trait Anxiety Inventory), depression (Beck Depression Inventory Short Form), and catastrophizing (Pain Catastrophizing Scale), were assessed. RESULTS: The participants mostly suffered from endometriosis (35.8%), irritable bowel syndrome (35.8%), bladder pain syndrome (32.1%), and vestibulodynia (28.3%). Baseline characteristics were similar. Women with a high sensitization score had more painful diseases diagnosed (2.7±1.3 vs 1.6±0.8; P=.002) and suffered for longer (11±8 vs 6±5 years; P=.028) than participants with a low score. The bladder maximum capacity was equivalent between participants (399±168 vs 465±164 mL; P=.18). However, the pain felt at each cystometric threshold was significantly increased in women with a high sensitization score. No difference was identified for the rectal pain pressure step (29.3±5.5 vs 30.7±6.5 mm Hg; P=.38). Rectal compliance was decreased in women with a high sensitization score with a considerable increase in pain felt. The average of pain pressure thresholds at the 5 vulvar sites tested was decreased in these participants (162.5±90.5 vs 358.7±196.5 g; P=.0003). Similar results were found for the average of the pain pressure thresholds at 6 muscles tested (1.34±0.41 vs 2.63±1.52 kg/m2; P=.0002). A longer period was needed for patients with high sensitization score to obtain a VAS <3 out of 10 after the stimulation of the bladder (4.52±5.26 vs 1.27±2.96 minutes; P=.01), the rectum (3.75±3.81 vs 1.19±1.23 minutes; P=.009), and the muscles (1.46±1.69 vs 0.64±0.40 minutes; P=.002). The psychological state was equivalent between groups. No association was found between the sensory thresholds and the psychological state results. The physical component of the quality of life score was reduced in women with high sensitization score (P=.0005), with no difference in the mental component. CONCLUSION: Using neurophysiological tests, this study showed that there are objective elements to assess for the presence of central sensitization, independently of psychological factors.

Prediction of individual trigeminal pain sensitivity from gray matter structure within the sensorimotor network.

OBJECTIVE: To determine whether multivariate pattern regression analysis based on gray matter (GM) images constrained to the sensorimotor network could accurately predict trigeminal heat pain sensitivity in healthy individuals. BACKGROUND: Prediction of individual pain sensitivity is of clinical relevance as high pain sensitivity is associated with increased risks of postoperative pain, pain chronification, and a poor treatment response. However, as pain is a subjective experience accurate identification of such individuals can be difficult. GM structure of sensorimotor regions have been shown to vary with pain sensitivity. It is unclear whether GM structure within these regions can be used to predict pain sensitivity. METHODS: In this cross-sectional study, structural magnetic resonance images and pain thresholds in response to contact heat stimulation of the left supraorbital area were obtained from 79 healthy participants. Voxel-based morphometry was used to extract segmented and normalized GM images. These were then constrained to a mask encompassing the functionally defined resting-state sensorimotor network. The masked images and pain thresholds entered a multivariate relevance vector regression analysis for quantitative prediction of the individual pain thresholds. The correspondence between predicted and actual pain thresholds was indexed by the Pearson correlation coefficient (r) and the mean squared error (MSE). The generalizability of the model was assessed by 10-fold and 5-fold cross-validation. Non-parametric permutation tests were used to estimate significance levels. RESULTS: Trigeminal heat pain sensitivity could be predicted from GM structure within the sensorimotor network with significant accuracy (10-fold: r = 0.53, p < 0.001, MSE = 10.32, p = 0.001; 5-fold: r = 0.46, p = 0.001, MSE = 10.54, p < 0.001). The resulting multivariate weight maps revealed that accurate prediction relied on multiple widespread regions within the sensorimotor network. CONCLUSION: A multivariate pattern of GM structure within the sensorimotor network could be used to make accurate predictions about trigeminal heat pain sensitivity at the individual level in healthy participants. Widespread regions within the sensorimotor network contributed to the predictive model.

Effects of High-Definition Transcranial Direct Current Stimulation Targeting the Anterior Cingulate Cortex on the Pain Thresholds: A Randomized Controlled Trial.

BACKGROUND: The majority of existing clinical studies used active transcranial direct current stimulation (tDCS) over superficial areas of the pain neuromatrix to regulate pain, with conflicting results. Few studies have investigated the effect of tDCS on pain thresholds by focusing on targets in deep parts of the pain neuromatrix. METHODS: This study applied a single session of high-definition tDCS (HD-tDCS) targeting the anterior cingulate cortex (ACC) and used a parallel and sham-controlled design to compare the antinociceptive effects in healthy individuals by assessing changes in pain thresholds. Sixty-six female individuals (mean age, 20.5 ± 2.4 years) were randomly allocated into the anodal, cathodal, or sham HD-tDCS groups. The primary outcome of the study was pain thresholds (pressure pain threshold, heat pain threshold, and cold pain threshold), which were evaluated before and after stimulation through the use of quantitative sensory tests. RESULTS: Only cathodal HD-tDCS targeting the ACC significantly increased heat pain threshold (P < 0.05) and pressure pain threshold (P < 0.01) in healthy individuals compared with sham stimulation. Neither anodal nor cathodal HD-tDCS showed significant analgesic effects on cold pain threshold. Furthermore, no statistically significant difference was found in pain thresholds between anodal and sham HD-tDCS (P > 0.38). Independent of HD-tDCS protocols, the positive and negative affective schedule scores were decreased immediately after stimulation compared with baseline. CONCLUSIONS: The present study has found that cathodal HD-tDCS targeting the ACC provided a strong antinociceptive effect (increase in pain threshold), demonstrating a positive biological effect of HD-tDCS.

Age-, gender- and body site-specific reference values of thermal Quantitative Sensory Testing in the Italian population using the Q-sense device.

BACKGROUND: Age-, gender- and body site-specific values of thermal Quantitative Sensory Testing (QST) measures have not yet been reported using the novel and cheap device 'Q-sense'. Here, we aimed to assess normative values of Q-sense-derived parameters in a representative Italian population. METHODS: QST parameters were measured in 84 healthy participants (42 males; aged 20-76 years) equally distributed into three age groups (18-39, 40-59 and 60-80 years). We explored the Warm and the Cold Detection Thresholds (WDT and CDT, respectively) with the method of limits (MLI) and the method of levels (MLE), and the Heat Pain Threshold (HPT) with the MLI. We tested the trigeminal supraorbital region, the hand thenar, and the foot dorsum on the right body side. RESULTS: We calculated non-parametric reference limits (2.5-97.5th) according to age, gender and tested site. All QST measures were affected by age, gender and tested site. In the extra-trigeminal body sites, females showed lower WDT and higher CDT, while males had higher HPT. Worse sensory discriminative abilities and increased HPT values were found in people aged over 40 on the foot. Age-related differences were more evident with the reaction time-dependent MLI vs. MLE paradigm. CONCLUSIONS: Demographic characteristics must be considered when QST is used in the clinical setting. The definition of reference limits for sensory testing with the Q-sense herein provided can pave the way towards a more widespread use of thermal QST for diagnosing small fiber neuropathy and for identifying patients' profiles in different chronic pain syndromes.

Effect of a Multimodal Supervised Therapeutic Exercise Program on Quality of Life, Pain, and Lumbopelvic Impairments in Women With Endometriosis Unresponsive to Conventional Therapy: A Randomized Controlled Trial.

OBJECTIVE: To evaluate the effectiveness of "Physio-EndEA", a multimodal nine-week supervised exercise intervention, on quality of life, pain, and lumbopelvic impairments in women with endometriosis unresponsive to conventional therapy. DESIGN: Parallel-group randomized controlled trial. Outcomes were measured at baseline, post-intervention, and at 1 year. SETTING: Two Public University Hospitals. PARTICIPANTS: This trial included 31 women with endometriosis (N=31) randomly allocated to "Physio-EndEA" group (n=16) or control group (n=15). Four participants dropped out of the study for causes unrelated to the intervention. INTERVENTIONS: The "Physio-EndEA" program consisted of a 1-week lumbopelvic stabilization learning phase followed by an 8-week phase of stretching, aerobic, and resistance exercises focused on the lumbopelvic area. It was sequentially instructed and supervised by a trained physiotherapist (with volume and intensity progression) and adapted daily to the potential of each participant. Control group received the usual treatment stipulated by their gynecologist. MAIN OUTCOME MEASURES: The primary outcome was quality of life. Secondary outcomes were pain intensity, pressure pain thresholds, pain-related catastrophic thoughts, abdominal and back strength, lumbopelvic stability, and muscle architecture. RESULTS: Adherence rate was 90.6% and mean (±standard deviation) satisfaction was 9.44±0.73 out of 10. No remarkable health problems were reported during the trial. In comparison with controls, the quality of life was improved post-intervention and at 1 year in the Physio-EndEA group with large effect sizes (d>0.80). This group also evidenced: a reduced intensity of dyspareunia, catastrophic thoughts; an increase in pelvic, lumbar, and distal pressure pain thresholds; increases in abdominal and back strength and lumbopelvic stability; and increased thickness of transversus abdominis (right side) and width of lumbar multifidus (left side). CONCLUSION: A 9-week program of multimodal supervised therapeutic exercise is a feasible and effective intervention to improve QoL in women with endometriosis. This program also offers benefits in terms of pain/sensitization and lumbopelvic impairments.