Subjective Pain Intensity Research Articles

The effects of KinesioTape on the treatment of lateral epicondylitis

Study DesignRandomized clinical trial. IntroductionKinesioTape (KT) is a noninvasive method to treat pain and muscular dysfunction. PurposeTo investigate the effect of KT with and without tension on pain intensity, pain pressure threshold, grip strength and disability in individuals with lateral epicondylitis, and myofacial trigger points in forearm muscles. MethodsThirty women with lateral epicondylitis and myofacial trigger point in forearm muscles were randomly assigned to KT with tension and placebo (KT without tension). The treatment was provided 3 times in one week, and outcome measures were assess pre-post treatment. ResultsThe mean score of visual analogue scale (VAS) during activity decreased significantly from 6.4 and 6 pretest to 2.53 and 4.66 posttest, respectively, for the KT with and without tension groups. The mean score of Disabilities of the Arm, Shoulder and Hand decreased significantly from 16.82 and 22.79 pretest to 8.65 and 8.29 posttest, respectively, for the KT with and without tension groups. A paired t-test revealed a significant reduction in VAS during activity and Disabilities of the Arm, Shoulder and Hand before and after treatment in both groups (P < .05). Pain pressure threshold, grip strength, and VAS using an algometer revealed no significant differences. The study showed no significant difference in variables immediately after intervention. DiscussionImprovements in functional disability were superior when KT was used with tension, than obtained with a placebo-no tension application. ConclusionThe application of KT produces an improvement in pain intensity and upper extremity disability in subjects with LE and MTP in forearm muscles, and KT with tension was more effective than placebo group. Level of EvidenceNA. Trial Registration Number100-216.

Transcranial direct current stimulation over the opercular somatosensory region does not influence experimentally induced pain: a triple blind, sham-controlled study.

Transcranial magnetic stimulation (TMS) over the opercular somatosensory region (OP), which includes the secondary somatosensory cortex and the insular cortex, suppresses pain sensation. However, whether transcranial direct current stimulation (tDCS) over the OP has a similar effect on pain sensation remains unknown. We examined whether pain sensation would be suppressed by tDCS over the OP. Our experiment with a triple-blind, sham-controlled, crossover design involved 12 healthy participants. Participants were asked to rate their subjective pain intensity during and after three types of bihemispheric tDCS: right anodal/left cathodal OP tDCS, left anodal/right cathodal OP tDCS (2 mA, 12 min), and sham tDCS (15 s). Pain stimuli were alternately applied to the dorsum of each index finger using intraepidermal electrical stimulation. We observed no significant effect of tDCS over the OP on the perception of experimentally induced pain. Subjective pain intensity did not differ significantly between the three tDCS conditions. The present null results have crucial implications for the selection of optimal stimulation regions and parameters for clinical pain treatment.

Empathy in female submissive BDSM practitioners

The practice of bondage/discipline, dominance/submission, sadism/masochism (BDSM) sometimes is associated with giving and receiving pain. It remains unresolved how BDSM practitioners perceive the pain of other people. This study investigated whether and how the BDSM experience affects human empathy. Experiment 1 measured trait empathy and subjective empathic responses in BDSM practitioners and control respondents. The results revealed lower trait empathy scores and subjective pain intensity ratings in the female submissive group (Subs) compared to controls. Experiment 2 measured participants’ neural responses to others’ suffering by recording event-related potentials (ERPs) from female Subs and controls while viewing painful and neutral expressions. We found that the differential amplitudes between painful and neutral expressions in the frontal N1 (92–112ms), frontal P2 (132–172ms) and central late LPP (700–1000ms) were reduced in the submissive group versus the control group. These findings suggest that being in the submissive role during BDSM practice weakens female individuals’ empathic responses to others’ suffering at both the behavioral and neural levels.

Glucose Metabolic Changes in the Brain and Muscles of Patients with Nonspecific Neck Pain Treated by Spinal Manipulation Therapy: A [18F]FDG PET Study.

Objective. The aim of this study was to investigate changes in brain and muscle glucose metabolism that are not yet known, using positron emission tomography with [18F]fluorodeoxyglucose ([18F]FDG PET). Methods. Twenty-one male volunteers were recruited for the present study. [18F]FDG PET scanning was performed twice on each subject: once after the spinal manipulation therapy (SMT) intervention (treatment condition) and once after resting (control condition). We performed the SMT intervention using an adjustment device. Glucose metabolism of the brain and skeletal muscles was measured and compared between the two conditions. In addition, we measured salivary amylase level as an index of autonomic nervous system (ANS) activity, as well as muscle tension and subjective pain intensity in each subject. Results. Changes in brain activity after SMT included activation of the dorsal anterior cingulate cortex, cerebellar vermis, and somatosensory association cortex and deactivation of the prefrontal cortex and temporal sites. Glucose uptake in skeletal muscles showed a trend toward decreased metabolism after SMT, although the difference was not significant. Other measurements indicated relaxation of cervical muscle tension, decrease in salivary amylase level (suppression of sympathetic nerve activity), and pain relief after SMT. Conclusion. Brain processing after SMT may lead to physiological relaxation via a decrease in sympathetic nerve activity.

Effectiveness of median nerve neural mobilization versus oral ibuprofen treatment in subjects who suffer from cervicobrachial pain: a randomized clinical trial.

IntroductionOral ibuprofen (OI) and median nerve neural mobilization (MNNM) are first line treatments for patients who suffer cervicobrachial pain (CP). OI may produce side effects which are not tolerated by all subjects who suffer CP, whereas MNNM has no known side effects. Therefore, the aim of this study was to assess the effectiveness of both treatments (OI vs. MNNM) in CP.Material and methodsThis investigation was a blinded parallel randomized clinical trial (NCT02593721). Sixty-two participants diagnosed with CP were recruited and randomly assigned to 2 groups (n = 31), which received MNNM or 1200 mg/day OI treatment for 6 weeks. The numeric rating scale for pain intensity was the primary outcome. The cervical rotation range of motion (CROM) and the upper limb function were the secondary outcomes.ResultsThe results showed that OI treatment (η2 = 0.612–0.755) was clearly superior to MNNM (η2 = 0.816–0.821) in all assessments (p < 0.05) except for the CROM device results, which were equivalent to those of the MNNM group (p > 0.05). Three subjects were discharged because of OI side effects.ConclusionsOral ibuprofen may be superior to MNNM for pain reduction and upper limb function increase of subjects with CP. Nevertheless, both treatments were effective. Median nerve neural mobilization may be considered an effective non-pharmaceutical treatment option in subjects with CP. Regarding OI adverse effects, our findings challenge the role of pharmacologic versus manual therapy as possible treatments that may improve pain intensity and upper limb functionality in subjects with CP.

Effectiveness of osteopathic manipulative treatment versus osteopathy in the cranial field in temporomandibular disorders – a pilot study

Purpose: Temporomandibular disorders are a common musculoskeletal condition causing severe pain, physical and psychological disability. The effect and evidence of osteopathic manipulative treatment and osteopathy in the cranial field is scarce and their use are controversial. The purpose of this pilot study was to evaluate the effectiveness of osteopathic manipulative treatment and osteopathy in the cranial field in temporomandibular disorders.Methods: A randomized clinical trial in patients with temporomandibular disorders was performed. Forty female subjects with long-term temporomandibular disorders (>3 months) were included. At enrollment, subjects were randomly assigned into two groups: (1) osteopathic manipulative treatment group (20 female patients) and (2) osteopathy in the cranial field group (20 female patients). Examination was performed at baseline (E0) and at the end of the last treatment (E1), consisting of subjective pain intensity with the Visual Analog Scale, Helkimo Index and SF-36 Health Survey. Subjects had five treatments, once a week. 36 subjects completed the study (33.7 ± 10.3 y).Results: Patients in both groups showed significant reduction in Visual Analog Scale score (osteopathic manipulative treatment group: p = 0.001; osteopathy in the cranial field group: p< 0.001), Helkimo Index (osteopathic manipulative treatment group: p = 0.02; osteopathy in the cranial field group: p = 0.003) and a significant improvement in the SF-36 Health Survey – subscale “Bodily Pain” (osteopathic manipulative treatment group: p = 0.04; osteopathy in the cranial field group: p = 0.007) after five treatments (E1). All subjects (n = 36) also showed significant improvements in the above named parameters after five treatments (E1): Visual Analog Scale score (p< 0.001), Helkimo Index (p< 0.001), SF-36 Health Survey – subscale “Bodily Pain” (p = 0.001). The differences between the two groups were not statistically significant for any of the three target parameters.Conclusion: Both therapeutic modalities had similar clinical results. The findings of this pilot trial support the use of osteopathic manipulative treatment and osteopathy in the cranial field as an effective treatment modality in patients with temporomandibular disorders. The positive results in both treatment groups should encourage further research on osteopathic manipulative treatment and osteopathy in the cranial field and support the importance of an interdisciplinary collaboration in patients with temporomandibular disorders.Implications for rehabilitationTemporomandibular disorders are the second most prevalent musculoskeletal condition with a negative impact on physical and psychological factors.There are a variety of options to treat temporomandibular disorders.This pilot study demonstrates the reduction of pain, the improvement of temporomandibular joint dysfunction and the positive impact on quality of life after osteopathic manipulative treatment and osteopathy in the cranial field.Our findings support the use of osteopathic manipulative treatment and osteopathy in the cranial field and should encourage further research on osteopathic manipulative treatment and osteopathy in the cranial field in patients with temporomandibular disorders.Rehabilitation experts should consider osteopathic manipulative treatment and osteopathy in the cranial field as a beneficial treatment option for temporomandibular disorders.

Interaction of acupuncture treatment and manipulation laterality modulated by the default mode network.

Appropriate selection of ipsilateral or contralateral electroacupuncture (corresponding to the pain site) plays an important role in reaching its better curative effect; however, the involving brain mechanism still remains unclear. Compared with the heat pain model generally established in previous study, capsaicin pain model induces reversible cutaneous allodynia and is proved to be better simulating aspects of clinical nociceptive and neuropathic pain. In the current study, 24 subjects were randomly divided into two groups with a 2 × 2 factorial design: laterality (ipsi- or contralateral side, inter-subject) × treatment with counter-balanced at an interval of one week (verum and placebo electroacupuncture, within-subject). We observed subjective pain intensity and brain activations changes induced by capsaicin allodynia pain stimuli before and after electroacupuncture treatment at acupoint LI4 for 30 min. Analysis of variance results indicated that ipsilateral electroacupuncture treatment produced significant pain relief and wide brain signal suppressions in pain-related brain areas compared with contralateral electroacupuncture. We also found that verum electroacupuncture at either ipsi- or contralateral side to the pain site exhibited comparable significant magnitudes of analgesic effect. By contrast, placebo electroacupuncture elicited significant pain reductions only on the ipsilateral rather than contralateral side. It was inferred that placebo analgesia maybe attenuated on the region of the body (opposite to pain site) where attention was less focused, suggesting that analgesic effect of placebo electroacupuncture mainly rely on the motivation of its spatial-specific placebo responses via attention mechanism. This inference can be further supported by the evidence that the significant interaction effect of manipulation laterality and treatment was exclusively located within the default mode network, including the bilateral superior parietal lobule, inferior parietal lobule, precuneus, and left posterior cingulate cortex. It is also proved that disruptions of the default mode network may account for the cognitive and behavioral impairments in chronic pain patients. Our findings further suggested that default mode network participates in the modulation of spatial-oriented attention on placebo analgesia as a mechanism underlying the degree to which treatment side corresponding to the pain.

EPV 13. Pain-related evoked potentials depict the effect of conditioned pain modulation in healthy subjects

Background Conditioned pain modulation (CPM) evaluates the pain modulating effect of a noxious conditioning stimulus (CS) on another noxious test stimulus (TS), mostly based on subjective pain ratings (Yarnitsky et al., 2015). We now use electrical stimulation (TS) of intraepidermal nerve fibres, reflecting the nociceptive A δ -fibre transmission (Katsarava et al., 2006), to investigate whether cortically recorded pain-related evoked potentials (PREP) can depict the CPM-effect. Methods We examined 17 healthy subjects using a novel CPM-protocol. We recorded PREP (including the assessment of the PREP-induced pain) over Cz referred to linked ear lobes, stimulating the dominant hand with the two-fold of the individual pain threshold (2PT) using three custom-built concentric surface electrodes. We than evaluated the CPM-effect in a cross-over design with immersion of the non-dominant hand into either 10°C or 24°C (control) cold water as CS. As TS we recorded PREP stimulating with pain intensity of 40–60 on the NRS 0–100 before, and repeatedly during and after CS application. Statistics: Pearson correlation, ANOVA, paired t -test, linear regression. Result At 2PT the PREP-induced pain and PREP-amplitude did not correlate. With increasing stimulus intensity from 2.3 ± 0.3mN to 6.7 ± 1.4mN, the PREP-induced pain raised from 24.5 ± 3.8 to 52.1 ± 1.1 ( p ± 4.4 vs. 30.3 ± 12.5) and PREP-amplitude (42.1 ± 13.4 μ V vs. 28.7 ± 10.5 μ V) decreased during and increased after CS termination (all p 0.001). The changes of PREP-induced pain and PREP-amplitudes correlated only in the 10°C-condition ( r =0.5; p =0.042). Discussion The presented novel CPM-protocol with hand immersion in painful cold water as conditioning stimulus can be used to modulate the PREP-induced pain intensity in healthy subjects and, more importantly, the PREP-recordings are able to depict quantitatively the CPM-effect electrophysiologically in an objective way.

The effect of manipulative manual therapy, in improving range of motion and reducing the intensity of pain in subjects with ankle sprain – A systematic review

The effect of manipulative manual therapy, in improving range of motion and reducing the intensity of pain in subjects with ankle sprain – A systematic review

Efectos de la acupuntura en pacientes con fibromialgia: protocolo de un estudio controlado aleatorizado

BackgroundFibromyalgia is a multidimensional disorder for which treatment as yet remains unsatisfactory. Studies of an acupuncture-based approach, despite its broad acceptance among patients and healthcare staff, have not produced sufficient evidence of its effectiveness in treating this syndrome. The present study aims to evaluate the effectiveness of individualized acupuncture for patients with fibromyalgia, with respect to reducing their pain and level of incapacity, and improving their quality of life. Methods/designRandomized controlled multicentre study, with 156 outpatients, aged over 17 years, diagnosed with fibromyalgia according to American College of Rheumatology criteria, either alone or associated with severe depression, according to the criteria of the Diagnostic and Statistical Manual for Mental Disorders. The participants will be randomly assigned to receive either “True acupuncture” or “Sham acupuncture”. They will be evaluated using a specific measurement system, constituted of the Fibromyalgia Impact Questionnaire and the Hamilton rating scale for depression. Also taken into consideration will be the clinical and subjective pain intensity, the patient's family structure and relationships, psychological aspects, quality of life, the duration of previous temporary disability, the consumption of antidepressant, analgesic and anti-inflammatory medication, and the potential effect of factors considered to be predictors of a poor prognosis. All these aspects will be examined by questionnaires and other suitably-validated instruments. The results obtained will be analysed at 10 weeks, and 6 and 12 months from the start of treatment. DiscussionThis trial will utilize high quality trial methodologies in accordance with CONSORT guidelines. It may provide evidence for the effectiveness of acupuncture as a treatment for fibromyalgia either alone or associated with severe depression. Trial registrationISRCTN trial number ISRCTN60217348 (19 October 2010).

Spinal mobilization vs conventional physiotherapy in the management of chronic low back pain due to spinal disk degeneration: a randomized controlled trial

Objectives: The aim of the study was to examine the efficacy of spinal mobilization in subjects with low back pain (LBP) and associated spinal disk degeneration.Methods: Seventy-five subjects suffering from chronic LBP (>3 months) were randomly allocated into 3 groups of 25 subjects each. Each group received five treatment sessions with the first group receiving manual therapy (MT) (spinal mobilization), the second a sham treatment, and the third conventional physiotherapy (CP) (stretching exercises, transcutaneous electrical nerve stimulation, and massage). Subjects were assessed for their pain intensity using the numerical pain rating scale and for their self-reported disability using the Oswestry and Roland-Morris Questionnaire at baseline and after the completion of the five treatment sessions.Results: Paired t-tests showed a significant improvement for all outcome measures in the MT and CP group (p < 0.05). Analysis of covariance revealed that the MT group had significant improvement in all outcome measures in comparison with the sham and CP group (p < 0.05), whereas no significant difference was observed between the sham and CP group (p > 0.05).Discussion: MT is preferable to CP in order to reduce the pain intensity and disability in subjects with chronic LBP and associated disk degeneration. The findings of this study may lead to the establishment of spinal mobilization as one of the most preferable approaches for the management of LBP due to disk degeneration.Level of evidence: 1b.

Prospective Mediation Models of Sleep, Pain, and Daily Function in Children With Arthritis Using Ecological Momentary Assessment.

Sleep is an emerging area of concern in children with juvenile idiopathic arthritis (JIA). Research shows the presence of poor sleep quality and related adverse outcomes in pediatric pain populations, including JIA, but few studies have examined the prospective patterns of association between sleep and associated outcomes. This prospective study evaluated the direction and magnitude of associations between subjective sleep characteristics (sleep quality, difficulty initiating sleep, and sleep duration), pain intensity, and functional limitations in children with JIA. We hypothesized that pain intensity would partially mediate the relationship between sleep and functional limitations. Children and adolescents with JIA (n=59; age range, 8 to 18 y) recruited during clinic visits, completed smartphone-based diaries for 1 month. Subjective sleep characteristics were reported each morning; pain and functioning were assessed 3 times daily. As hypothesized, the associations between sleep quality and functional limitations and between difficulty initiating sleep and functional limitations were partially mediated by pain intensity, at any given moment (z=-3.27, P=0.001, z=2.70, P<0.05). Mediation was not detected in a model testing the association between sleep duration, pain intensity, and functional limitations (z=-0.58, P=0.56). Results suggest that sleep is integral to understanding the momentary association between pain intensity and functioning in children with JIA.

Patterns of Cerebral Blood Flow Modulation During Painful Stimulation in Fibromyalgia: A Transcranial Doppler Sonography Study.

This study analyzed the temporal dynamics of cerebral blood flow (CBF) modulations, during painful stimulation in fibromyalgia syndrome (FMS), using functional transcranial Doppler sonography. Blood flow velocities were recorded bilaterally in the anterior (ACA) and middle (MCA) cerebral arteries of 24 FMS patients and 20 healthy individuals during exposure to painful pressure stimulation. Participants were presented with two stimulation blocks: a) fixed pressure (2.4 kg) and b) stimulation pressure, individually calibrated to produce equal subjective and moderate pain intensity in all participants. A complex pattern of CBF modulations arose, comprising four main components: an anticipatory increase before stimulation onset, an early increase, a transient decrease to baseline or below, and a final increase. Group differences were observed in all components. The anticipatory component only arose in FMS patients, specifically in the ACA. Patients exhibited a greater early CBF increase under the fixed pressure condition, predominantly in the right ACA. A stronger CBF decrease after the early component was observed in patients during the equal pain condition, in the ACA and MCA. Significant associations were found between clinical pain severity and CBF responses in the MCA. The results demonstrate that acute pain processing is associated with a complex pattern of CBF modulation, where FMS patients exhibited alterations in all phases of the response. The aberrances may be ascribed to psychophysiological phenomena, including central nervous nociceptive sensitization and protective-defensive reflex mechanisms. The anticipatory CBF response in patients may relate to various cognitive, emotional, and behavioral mechanisms involved in pain chronification.

Dry needling of the trapezius muscle in office workers with neck pain: a randomized clinical trial

Background: Neck pain is a frequent complaint in office workers. This pain can be caused by myofascial trigger points (MTrPs) in the trapezius muscle. This study aimed to determine the effectiveness of deep dry needling (DDN) of active MTrPs in the trapezius muscle.Methods: A randomized, single blinded clinical trial was carried out at the Physical Therapy Department at Physiotherapy in Women's Health Research Group at Physical Therapy Department of University of Alcalá, in Alcalá de Henares, Madrid, Spain. Forty-four office workers with neck pain and active MTrPs in the trapezius muscle were randomly allocated to either the DDN or the control group (CG). The participants in the DDN group were treated with DDN of all MTrPs found in the trapezius muscle. They also received passive stretch of the trapezius muscle. The CG received the same passive stretch of the trapezius muscle only. The primary outcome measure was subjective pain intensity, measured using a visual analogue scale (VAS). Secondary outcomes were pressure pain threshold (PPT), cervical range of motion (CROM) and muscle strength. Data were collected at baseline, after interventions and 15 days after the last treatment.Results: Differences were found between the DDN group and the CG for the VAS (P < 0.001), PPT (P < 0.001), range of motion (AROM) (P < 0.05) and strength (P < 0.05) after intervention and at the 15-day follow-up.Discussion: Deep dry needling and passive stretch seems to be more effective than passive stretch only. The effects are maintained in the short term. The results support the use of DDN in the management of trapezius muscle myofascial pain syndrome in neck pain.

Circumplex Model of Affect: A Measure of Pleasure and Arousal During Virtual Reality Distraction Analgesia.

Immersive virtual reality (VR) distraction provides clinically effective pain relief and increases subjective reports of "fun" in medical settings of procedural pain. The goal of this study was to better describe the variable of "fun" associated with VR distraction analgesia using the circumplex model (pleasure/arousal) of affect. Seventy-four healthy volunteers (mean age, 29 years; 37 females) received a standardized, 18-minute, multimodal pain sequence (alternating thermal heat and electrical stimulation to distal extremities) while receiving immersive, interactive VR distraction. Subjects rated both their subjective pain intensity and fun using 0-10 Graphic Rating Scales, as well as the pleasantness of their emotional valence and their state of arousal on 9-point scales. Compared with pain stimulation in the control (baseline, no VR) condition, immersive VR distraction significantly reduced subjective pain intensity (P < 0.001). During VR distraction, compared with those reporting negative affect, subjects reporting positive affect did so more frequently (41 percent versus 9 percent), as well as reporting both greater pain reduction (22 percent versus 1 percent) and fun scores (7.0 ± 1.9 versus 2.4 ± 1.4). Several factors-lower anxiety, greater fun, greater presence in the VR environment, and positive emotional valence-were associated with subjective analgesia during VR distraction. Immersive VR distraction reduces subjective pain intensity induced by multimodal experimental nociception. Subjects who report less anxiety, more fun, more VR presence, and more positive emotional valence during VR distraction are more likely to report subjective pain reduction. These findings indicate VR distraction analgesia may be mediated through anxiolytic, attentional, and/or affective mechanisms.

Blood pressure and the perception of illusive pain.

Numerous studies have documented an inverse relationship between blood pressure and sensitivity to experimental nociceptive stimulation. The present study aimed to investigate possible associations between blood pressure and the occurrence and intensity of paradoxical pain induced by the thermal grill paradigm. Thirty-one healthy subjects were stimulated three times for 1 min with the nonnoxious temperatures of 15°C and 41°C set at the interlaced cold and warm bars of a water bath-driven thermal grill. Blood pressure and heart rate were recorded concomitantly. On account of previous observations of an association between the sensitivity of the cardiac baroreflex and pain perception, this parameter was additionally obtained. Numerical rating scales were used to quantify subjective pain intensity and pain unpleasantness; subjects were classified as responders and nonresponders to thermal grill stimulation based on pain intensity ratings. Responders exhibited lower systolic and diastolic blood pressure than nonresponders, and inverse linear associations arose between blood pressure and pain intensity and unpleasantness. Baroreflex sensitivity was unrelated to pain ratings. The findings confirmed the hypothesis of a blood pressure dependence of paradoxical pain and support the notion that the cardiovascular and pain regulatory systems interact not only in the processing of pain elicited by noxious input, but also in nonnoxiously generated illusive pain. While this finding is not consistent with the assumption of an involvement of the baroreflex system in mediating the observed interaction, psychological traits and neurochemical factors are alternatively considered.

Age Moderates the Relationships between Family Functioning and Neck Pain/Disability.

This cross-sectional clinical study was designed to explore the relationships between family functioning, coping styles, and neck pain and neck disability. It was hypothesized that better family functioning and more effective coping styles would be associated with less pain and pain-related disability. It also was hypothesized that these relationships would be stronger in older people because they have fewer resources, more limited coping styles, and may depend more on their family for support. In this study, 88 women with chronic non-traumatic neck pain completed the Family Assessment Measure (FAM), Coping Inventory for Stressful Situations (CISS), Neck Disability Index (NDI), and a Visual-Analogue Scale (VAS) measuring the subjective intensity of neck pain. Zero-order and partial correlations and hierarchical stepwise regression were performed. CISS was not correlated with the NDI orVAS. Good family functioning was correlated with lower NDI and VAS scores. Age was found to moderate the relationship between the FAM and both NDI and VAS. This relationship was significant and positive in older patients, but non-significant in younger patients. It was concluded that better family functioning is associated with lower neck disability and pain intensity, especially in the case of older women suffering from non-traumatic neck pain.

Decoding Subjective Intensity of Nociceptive Pain from Pre-stimulus and Post-stimulus Brain Activities.

Pain is a highly subjective experience. Self-report is the gold standard for pain assessment in clinical practice, but it may not be available or reliable in some populations. Neuroimaging data, such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), have the potential to be used to provide physiology-based and quantitative nociceptive pain assessment tools that complements self-report. However, existing neuroimaging-based nociceptive pain assessments only rely on the information in pain-evoked brain activities, but neglect the fact that the perceived intensity of pain is also encoded by ongoing brain activities prior to painful stimulation. Here, we proposed to use machine learning algorithms to decode pain intensity from both pre-stimulus ongoing and post-stimulus evoked brain activities. Neural features that were correlated with intensity of laser-evoked nociceptive pain were extracted from high-dimensional pre- and post-stimulus EEG and fMRI activities using partial least-squares regression (PLSR). Further, we used support vector machine (SVM) to predict the intensity of pain from pain-related time-frequency EEG patterns and BOLD-fMRI patterns. Results showed that combining predictive information in pre- and post-stimulus brain activities can achieve significantly better performance in classifying high-pain and low-pain and in predicting the rating of perceived pain than only using post-stimulus brain activities. Therefore, the proposed pain prediction method holds great potential in basic research and clinical applications.

Sensory cognitive abnormalities of pain in autism spectrum disorder: a case-control study.

Background The Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) recently included sensory processing abnormalities in the diagnostic criteria for individuals with autism spectrum disorder (ASD). However, there is no standard method for evaluating sensory abnormalities in individuals with ASD.MethodsFifteen individuals with ASD and 15 age- and sex-matched controls were enrolled in this study. We compared objective pain sensitivity by measuring the pain detection threshold and pain tolerance to three different stimuli (electricity, heat, and cold). Then, we compared both subjective pain sensitivity, assessed by the visual analog scale (VAS), and quality of pain, assessed by the short-form McGill Pain Questionnaire (SF-MPQ), to determine the maximum tolerable pain intensities of each stimulation.ResultsThe pain detection threshold and pain tolerance of individuals with ASD were not impaired, indicating that there were no differences in the somatic perception of pain between groups. However, individuals with ASD were hyposensitive to subjective pain intensity compared to controls (VAS; electrical: p = 0.044, cold: p = 0.011, heat: p = 0.042) and hyposensitive to affective aspects of pain sensitivity (SF-MPQ; electrical: p = 0.0071, cold: p = 0.042).ConclusionsOur results suggest that the cognitive pathways for pain processing are impaired in ASD and, furthermore, that our methodology can be used to assess pain sensitivity in individuals with ASD. Further investigations into sensory abnormalities in individuals with ASD are needed to clarify the pathophysiologic processes that may alter sensory processing in this disorder.

Gender influence on clinical presentation and high-resolution ultrasound findings in primary carpal tunnel syndrome: do women only differ in incidence?

High-resolution ultrasound is increasingly used in the diagnosis of carpal tunnel syndrome; yet little is known about gender differences in clinical presentation and ultrasound findings. In this high-resolution ultrasound-based retrospective study in 170 cases, we assessed gender influence in CTS in terms of the severity of neural alterations by wrist-to-forearm ratio (WFR), epineural thickening, loss of fascicular anatomy, as well as classical signs and symptoms. The control group consisted of 42 wrists. Women present with a greater WFR at first admission are affected more often bilaterally, and report less subjective pain intensity, while men report fewer nightly pain episodes at higher WFR. Loss of fascicular anatomy is three times more frequent in women. An increase in epineural thickness, loss of fascicular anatomy, and involvement of more than 1.5 fingers correlate significantly with WFR regardless of sex. Women differ significantly from men in terms of clinical presentation and ultrasound findings upon first diagnosis of CTS, which should be included in further diagnostic considerations.