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Sample records for pain tolerance threshold

  1. Effect of GaAs Laser at 904 nm in the Pain Threshold in Tibia and Tolerance in Deltoid Evaluated by Pressure Algometry

    NASA Astrophysics Data System (ADS)

    Soares, Luiz G. P.; Sato, Sidney K.; Silveira, Landulfo; Aimbire, Flávio; Moreira, Leonardo M.; Pinheiro, Antônio L. B.

    2011-08-01

    The use of LLLT in pain relief is a controversial issue in Physiotherapy, with the efficacy of LLLT associated to pain relief still requiring significant study. Objective. This work focuses on the evaluation of the effect of low power GaAs laser at 904 nm in pressure pain threshold and tolerance in tibia and deltoid muscle, respectively. A total of 17 subjects were divided in two groups: active and sham laser. Measurements were taken before and after laser irradiation in healthy individuals using a pressure algometry, first verifying the viability of algometry to evaluate the pain threshold and tolerance inter individuals and comparing the differences of right and left sides in the same patients, and finally evaluating the pain threshold and tolerance before and after a single laser application. Laser energy density was of 4.0 J/cm2 with power density of 137 mW/cm2. Comparing algometry values of active laser group and the sham group, the pain tolerance in the deltoid muscle did not change among groups after laser irradiation, while it was also encountered a statistically significant difference in the pain threshold in tibia when comparing the laser active and sham laser (p<0.05). It was found that the active laser was effective in maintaining the pain threshold in tibia. The effective laser action in raising the pain threshold in tibia upon healthy individuals can suggest that the laser could be applied not only as curative but also with preventive purpose.

  2. Auricular Acupressure Can Modulate Pain Threshold

    PubMed Central

    Santoro, Antonietta; Nori, Stefania Lucia; Lorusso, Letizia; Secondulfo, Carmine; Monda, Marcellino; Viggiano, Andrea

    2015-01-01

    The objective of our study was to investigate if auriculotherapy (AT) can modulate pain threshold. In our experiments, AT consisted of placing Vaccaria seeds over the “fingers point” of one ear. Two groups of healthy volunteers were enrolled for the study. Each subject was asked to perform an autoalgometric test developed by our group on three occasions: before, 1 hour after, AT and 24 hours after AT. Participants of the first group received a 2-minute long session of AT, while participants of the second group received a 2-minute long session of sham treatment, consisting of a puncture/massage above the skin of the neck. The autoalgometric test consisted of applying an increasing pressure with the finger-tips and finger-backs of four fingers by the subjects themselves (i.e., eight sites were evaluated) against a round-shaped needle for two times: until a minimum pain sensation (first time, minimal test) or a maximally tolerable pain sensation (second time, maximal test). Our results showed a significant higher pain threshold in the maximal test at 24 hours after AT compared to sham treatment. This result indicates for the first time that AT can increase pain tolerability, rather than affecting the minimal pain threshold. PMID:26236378

  3. Auricular Acupressure Can Modulate Pain Threshold.

    PubMed

    Santoro, Antonietta; Nori, Stefania Lucia; Lorusso, Letizia; Secondulfo, Carmine; Monda, Marcellino; Viggiano, Andrea

    2015-01-01

    The objective of our study was to investigate if auriculotherapy (AT) can modulate pain threshold. In our experiments, AT consisted of placing Vaccaria seeds over the "fingers point" of one ear. Two groups of healthy volunteers were enrolled for the study. Each subject was asked to perform an autoalgometric test developed by our group on three occasions: before, 1 hour after, AT and 24 hours after AT. Participants of the first group received a 2-minute long session of AT, while participants of the second group received a 2-minute long session of sham treatment, consisting of a puncture/massage above the skin of the neck. The autoalgometric test consisted of applying an increasing pressure with the finger-tips and finger-backs of four fingers by the subjects themselves (i.e., eight sites were evaluated) against a round-shaped needle for two times: until a minimum pain sensation (first time, minimal test) or a maximally tolerable pain sensation (second time, maximal test). Our results showed a significant higher pain threshold in the maximal test at 24 hours after AT compared to sham treatment. This result indicates for the first time that AT can increase pain tolerability, rather than affecting the minimal pain threshold. PMID:26236378

  4. Systemic Inflammation Decreases Pain Threshold in Humans In Vivo

    PubMed Central

    de Goeij, Moniek; van Eijk, Lucas T.; Vanelderen, Pascal; Wilder-Smith, Oliver H.; Vissers, Kris C.; van der Hoeven, Johannes G.; Kox, Matthijs; Scheffer, Gert Jan; Pickkers, Peter

    2013-01-01

    Background Hyperalgesia is a well recognized hallmark of disease. Pro-inflammatory cytokines have been suggested to be mainly responsible, but human data are scarce. Changes in pain threshold during systemic inflammation evoked by human endotoxemia, were evaluated with three quantitative sensory testing methods. Methods and Results Pressure pain thresholds, electrical pain thresholds and tolerance to the cold pressor test were measured before and 2 hours after the intravenous administration of 2 ng/kg purified E. coli endotoxin in 27 healthy volunteers. Another 20 subjects not exposed to endotoxemia served as controls. Endotoxemia led to a rise in body temperature and inflammatory symptom scores and a rise in plasma TNF-α, IL-6, IL-10 and IL-1RA. During endotoxemia, pressure pain thresholds and electrical pain thresholds were reduced with 20±4 % and 13±3 %, respectively. In controls only a minor decrease in pressure pain thresholds (7±3 %) and no change in electrical pain thresholds occurred. Endotoxin-treated subjects experienced more pain during the cold pressor test, and fewer subjects were able to complete the cold pressor test measurement, while in controls the cold pressor test results were not altered. Peak levels and area under curves of each individual cytokine did not correlate to a change in pain threshold measured by one of the applied quantitative sensory testing techniques. Conclusions and Significance In conclusion, this study shows that systemic inflammation elicited by the administration of endotoxin to humans, results in lowering of the pain threshold measured by 3 quantitative sensory testing techniques. The current work provides additional evidence that systemic inflammation is accompanied by changes in pain perception. PMID:24358337

  5. Computer-Delivered Social Norm Message Increases Pain Tolerance

    PubMed Central

    Pulvers, Kim; Schroeder, Jacquelyn; Limas, Eleuterio F.; Zhu, Shu-Hong

    2013-01-01

    Background Few experimental studies have been conducted on social determinants of pain tolerance. Purpose This study tests a brief, computer-delivered social norm message for increasing pain tolerance. Methods Healthy young adults (N=260; 44 % Caucasian; 27 % Hispanic) were randomly assigned into a 2 (social norm)×2 (challenge) cold pressor study, stratified by gender. They received standard instructions or standard instructions plus a message that contained artifically elevated information about typical performance of others. Results Those receiving a social norm message displayed significantly higher pain tolerance, F(1, 255)=26.95, p<.001, ηp2=.10 and pain threshold F(1, 244)=9.81, p=.002, ηp2=.04, but comparable pain intensity, p>.05. There were no interactions between condition and gender on any outcome variables, p>.05. Conclusions Social norms can significantly increase pain tolerance, even with a brief verbal message delivered by a video. PMID:24146086

  6. Social laughter is correlated with an elevated pain threshold

    PubMed Central

    Dunbar, R. I. M.; Baron, Rebecca; Frangou, Anna; Pearce, Eiluned; van Leeuwen, Edwin J. C.; Stow, Julie; Partridge, Giselle; MacDonald, Ian; Barra, Vincent; van Vugt, Mark

    2012-01-01

    Although laughter forms an important part of human non-verbal communication, it has received rather less attention than it deserves in both the experimental and the observational literatures. Relaxed social (Duchenne) laughter is associated with feelings of wellbeing and heightened affect, a proximate explanation for which might be the release of endorphins. We tested this hypothesis in a series of six experimental studies in both the laboratory (watching videos) and naturalistic contexts (watching stage performances), using change in pain threshold as an assay for endorphin release. The results show that pain thresholds are significantly higher after laughter than in the control condition. This pain-tolerance effect is due to laughter itself and not simply due to a change in positive affect. We suggest that laughter, through an endorphin-mediated opiate effect, may play a crucial role in social bonding. PMID:21920973

  7. Social laughter is correlated with an elevated pain threshold.

    PubMed

    Dunbar, R I M; Baron, Rebecca; Frangou, Anna; Pearce, Eiluned; van Leeuwen, Edwin J C; Stow, Julie; Partridge, Giselle; MacDonald, Ian; Barra, Vincent; van Vugt, Mark

    2012-03-22

    Although laughter forms an important part of human non-verbal communication, it has received rather less attention than it deserves in both the experimental and the observational literatures. Relaxed social (Duchenne) laughter is associated with feelings of wellbeing and heightened affect, a proximate explanation for which might be the release of endorphins. We tested this hypothesis in a series of six experimental studies in both the laboratory (watching videos) and naturalistic contexts (watching stage performances), using change in pain threshold as an assay for endorphin release. The results show that pain thresholds are significantly higher after laughter than in the control condition. This pain-tolerance effect is due to laughter itself and not simply due to a change in positive affect. We suggest that laughter, through an endorphin-mediated opiate effect, may play a crucial role in social bonding. PMID:21920973

  8. Quantum fault-tolerant thresholds for universal concatenated schemes

    NASA Astrophysics Data System (ADS)

    Chamberland, Christopher; Jochym-O'Connor, Tomas; Laflamme, Raymond

    Fault-tolerant quantum computation uses ancillary qubits in order to protect logical data qubits while allowing for the manipulation of the quantum information without severe losses in coherence. While different models for fault-tolerant quantum computation exist, determining the ancillary qubit overhead for competing schemes remains a challenging theoretical problem. In this work, we study the fault-tolerance threshold rates of different models for universal fault-tolerant quantum computation. Namely, we provide different threshold rates for the 105-qubit concatenated coding scheme for universal computation without the need for state distillation. We study two error models: adversarial noise and depolarizing noise and provide lower bounds for the threshold in each of these error regimes. Establishing the threshold rates for the concatenated coding scheme will allow for a physical quantum resource comparison between our fault-tolerant universal quantum computation model and the traditional model using magic state distillation.

  9. Fault-tolerant thresholds for encoded ancillae with homogeneous errors

    SciTech Connect

    Eastin, Bryan

    2007-02-15

    I describe a procedure for calculating thresholds for quantum computation as a function of error model given the availability of ancillae prepared in logical states with independent, identically distributed errors. The thresholds are determined via a simple counting argument performed on a single qubit of an infinitely large Calderbank-Shor-Steane code. I give concrete examples of thresholds thus achievable for both Steane and Knill style fault-tolerant implementations and investigate their relation to threshold estimates in the literature.

  10. Headache attributed to masticatory myofascial pain: impact on facial pain and pressure pain threshold.

    PubMed

    Costa, Y M; Porporatti, A L; Stuginski-Barbosa, J; Bonjardim, L R; Speciali, J G; Conti, P C R

    2016-03-01

    There is no clear evidence on how a headache attributed to temporomandibular disorder (TMD) can hinder the improvement of facial pain and masticatory muscle pain. The aim of this study was to measure the impact of a TMD-attributed headache on masticatory myofascial (MMF) pain management. The sample was comprised of adults with MMF pain measured according to the revised research diagnostic criteria for temporomandibular disorders (RDC/TMD) and additionally diagnosed with (Group 1, n = 17) or without (Group 2, n = 20) a TMD-attributed headache. Both groups received instructions on how to implement behavioural changes and use a stabilisation appliance for 5 months. The reported facial pain intensity (visual analogue scale - VAS) and pressure pain threshold (PPT - kgf cm(-2) ) of the anterior temporalis, masseter and right forearm were measured at three assessment time points. Two-way anova was applied to the data, considering a 5% significance level. All groups had a reduction in their reported facial pain intensity (P < 0·001). Mean and standard deviation (SD) PPT values, from 1·33 (0·54) to 1·96 (1·06) kgf cm(-2) for the anterior temporalis in Group 1 (P = 0·016), and from 1·27 (0·35) to 1·72 (0·60) kgf cm(-2) for the masseter in Group 2 (P = 0·013), had significant improvement considering baseline versus the 5th-month assessment. However, no differences between the groups were found (P > 0·100). A TMD-attributed headache in patients with MMF pain does not negatively impact pain management, but does change the pattern for muscle pain improvement. PMID:26440358

  11. The role of mood states underlying sex differences in the perception and tolerance of pain.

    PubMed

    Garofalo, John P; Lawler, Casey; Robinson, Richard; Morgan, Michael; Kenworthy-Heinige, Tawni

    2006-09-01

    While sex differences in pain reporting are frequently observed, the reasons underlying these differences remain unclear. The present study examined sex differences in self-report and physiological measures of pain threshold and tolerance following the administration of two laboratory pain-induction tasks. The primary study aim centered on determining whether repeated exposure to such tasks would yield sex differences in terms of pain threshold and tolerance. In addition, it was hypothesized that if such differences did exist, negative mood states might account for changes in pain ratings, threshold, and/or tolerance in subsequent exposure to noxious stimuli. Recruited from a convenience sample, 66 participants (44 female and 22 male) were exposed to both thermal and cold noxious stimuli at three separate times, while psychophysiological and self-report data were collected. Because women outnumbered men 2:1, Fisher z transformations were performed to determine whether the observed associations between mood states and pain ratings differed. We found stronger associations between fatigue and thermal-heat pain ratings for men at their first and third exposure to the pain task compared to women (z = 2.11, P < 0.05; z = 3.14, P < 0.001, respectively). Results indicated that women evidenced greater pain tolerance than men on both a behavioral and physiological level; however, they reported greater pain severity than men. Fatigue was also found to be particularly important to reports of pain severity in men and pain tolerance in response to noxious stimuli for women. Possible pathways in which mood states influenced these endpoints are discussed. PMID:17147596

  12. Pain threshold correlates with functional scores in osteoarthritis patients

    PubMed Central

    Kuni, Benita; Wang, Haili; Rickert, Markus; Ewerbeck, Volker; Schiltenwolf, Marcus

    2015-01-01

    Background and purpose Pain sensitization may be one of the reasons for persistent pain after technically successful joint replacement. We analyzed how pain sensitization, as measured by quantitative sensory testing, relates preoperatively to joint function in patients with osteoarthritis (OA) scheduled for joint replacement. Patients and methods We included 50 patients with knee OA and 49 with hip OA who were scheduled for joint replacement, and 15 control participants. Hip/knee scores, thermal and pressure detection, and pain thresholds were examined. Results Median pressure pain thresholds were lower in patients than in control subjects: 4.0 (range: 0–10) vs. 7.8 (4–10) (p = 0.003) for the affected knee; 4.5 (2–10) vs. 6.8 (4–10) (p = 0.03) for the affected hip. Lower pressure pain threshold values were found at the affected joint in 26 of the 50 patients with knee OA and in 17 of the 49 patients with hip OA. The American Knee Society score 1 and 2, the Oxford knee score, and functional questionnaire of Hannover for osteoarthritis score correlated with the pressure pain thresholds in patients with knee OA. Also, Harris hip score and the functional questionnaire of Hannover for osteoarthritis score correlated with the cold detection threshold in patients with hip OA. Interpretation Quantitative sensory testing appeared to identify patients with sensory changes indicative of mechanisms of central sensitization. These patients may require additional pain treatment in order to profit fully from surgery. There were correlations between the clinical scores and the level of sensitization. PMID:25323797

  13. Pain tolerance predicts human social network size

    PubMed Central

    Johnson, Katerina V.-A.; Dunbar, Robin I. M.

    2016-01-01

    Personal social network size exhibits considerable variation in the human population and is associated with both physical and mental health status. Much of this inter-individual variation in human sociality remains unexplained from a biological perspective. According to the brain opioid theory of social attachment, binding of the neuropeptide β-endorphin to μ-opioid receptors in the central nervous system (CNS) is a key neurochemical mechanism involved in social bonding, particularly amongst primates. We hypothesise that a positive association exists between activity of the μ-opioid system and the number of social relationships that an individual maintains. Given the powerful analgesic properties of β-endorphin, we tested this hypothesis using pain tolerance as an assay for activation of the endogenous μ-opioid system. We show that a simple measure of pain tolerance correlates with social network size in humans. Our results are in line with previous studies suggesting that μ-opioid receptor signalling has been elaborated beyond its basic function of pain modulation to play an important role in managing our social encounters. The neuroplasticity of the μ-opioid system is of future research interest, especially with respect to psychiatric disorders associated with symptoms of social withdrawal and anhedonia, both of which are strongly modulated by endogenous opioids. PMID:27121297

  14. Pain tolerance predicts human social network size.

    PubMed

    Johnson, Katerina V-A; Dunbar, Robin I M

    2016-01-01

    Personal social network size exhibits considerable variation in the human population and is associated with both physical and mental health status. Much of this inter-individual variation in human sociality remains unexplained from a biological perspective. According to the brain opioid theory of social attachment, binding of the neuropeptide β-endorphin to μ-opioid receptors in the central nervous system (CNS) is a key neurochemical mechanism involved in social bonding, particularly amongst primates. We hypothesise that a positive association exists between activity of the μ-opioid system and the number of social relationships that an individual maintains. Given the powerful analgesic properties of β-endorphin, we tested this hypothesis using pain tolerance as an assay for activation of the endogenous μ-opioid system. We show that a simple measure of pain tolerance correlates with social network size in humans. Our results are in line with previous studies suggesting that μ-opioid receptor signalling has been elaborated beyond its basic function of pain modulation to play an important role in managing our social encounters. The neuroplasticity of the μ-opioid system is of future research interest, especially with respect to psychiatric disorders associated with symptoms of social withdrawal and anhedonia, both of which are strongly modulated by endogenous opioids. PMID:27121297

  15. Intrarater Reliability of Pain Intensity, Tissue Blood Flow, Thermal Pain Threshold, Pressure Pain Threshold and Lumbo-Pelvic Stability Tests in Subjects with Low Back Pain

    PubMed Central

    Paungmali, Aatit; Sitilertpisan, Patraporn; Taneyhill, Khanittha; Pirunsan, Ubon; Uthaikhup, Sureeporn

    2012-01-01

    Purpose This preliminary study aimed to determine the intrarater reliability of the quantitative tests for the study of non-specific low back pain. Methods Test-retest reliability of the measurements of ratio data was determined by an intraclass correlation coefficient (ICC), standard error of measurements (SEMs), coefficient of variation (CV), and one-way repeated measures ANOVA using the values collected from 13 young individuals (25.8 ± 6.2 years) with chronic non-specific low back pain on two occasions separated by 2 days. Percent agreement of the ordinal data was also determined by Cohen's Kappa statistics (kappa). The measures consisted of tissue blood flow (BF), average pain visual analog scales (VAS), pressure pain threshold (PPT), cold pain threshold (CPT), heat pain threshold (HPT) and lumbo-pelvic stability test (LPST). An acceptable reliability was determined as the ICC values of greater than 0.85, SEMs less than 5%, CV less than 15%, the kappa scores of greater than 80% and no evidence of systematic error (ANOVA, P>0.05). Results ICC of all measures in the lumbo-sacral area were greater than 0.87. The kappa was also greater than 83%. Most measures demonstrated a minimal error of measurements and less potential of systemic error in nature. Only the SEMs and the CV of the CPT exceeded the acceptable level. Conclusions It is concluded that most of the quantitative measurements are reliable for the study of non-specific low back pain, however the CPT should be applied with care as it has a great variation among individuals and potential of measurement error. PMID:22461960

  16. Effect of manipulated state aggression on pain tolerance.

    PubMed

    Stephens, Richard; Allsop, Claire

    2012-08-01

    Swearing produces a pain lessening (hypoalgesic) effect for many people; an emotional response may be the underlying mechanism. In this paper, the role of manipulated state aggression on pain tolerance and pain perception is assessed. In a repeated-measures design, pain outcomes were assessed in participants asked to play for 10 minutes a first-person shooter video game vs a golf video game. Sex differences were explored. After playing the first-person shooter video game, aggressive cognitions, aggressive affect, heart rate, and cold pressor latency were increased, and pain perception was decreased. These data indicate that people become more pain tolerant with raised state aggression and support our theory that raised pain tolerance from swearing occurs via an emotional response. PMID:23045874

  17. Pain tolerance selectively increased by a sweet-smelling odor.

    PubMed

    Prescott, John; Wilkie, Jenell

    2007-04-01

    The mechanism underlying reported analgesic effects of odors in humans is unclear, although odor hedonics has been implicated. We tested whether odors that are sweet smelling through prior association with tasted sweetness might influence pain by activating the same analgesic mechanisms as sweet tastes. Inhalation of a sweet-smelling odor during a cold-pressor test increased tolerance for pain compared with inhalation of pleasant and unpleasant low-sweetness odors and no odor. There were no significant differences in pain ratings among the odor conditions. These results suggest that smelled sweetness can produce a naturally occurring conditioned increase in pain tolerance. PMID:17470253

  18. High pain sensitivity is distinct from high susceptibility to non-painful sensory input at threshold level.

    PubMed

    Hummel, Thomas; Springborn, Maria; Croy, Ilona; Kaiser, Jochen; Lötsch, Jörn

    2011-04-01

    Individuals may differ considerably in their sensitivity towards various painful stimuli supporting the notion of a person as stoical or complaining about pain. Molecular and functional imaging research provides support that this may extend also to other sensory qualities. Whether a person can be characterized as possessing a generally high or low sensory acuity is unknown. This was therefore assessed with thresholds to painful and non-painful stimuli, with a focus on chemical stimuli that besides pain may evoke clearly non-painful sensations such as taste or smell. In 36 healthy men and 78 women (ages 18 to 52 years), pain thresholds to chemo-somatosensory (intranasal gaseous CO(2)) and electrical stimuli (cutaneous stimulation) were significantly correlated (ρ(2)=0.2268, p<0.001). Two clusters separated persons with either high (n=72) or low (n=22) pain sensitivity. However, the correlation did not extend to non-painful stimuli of other sensory qualities, i.e., for the rose-like odor phenyl ethyl alcohol and gustatory thresholds for sour (citric acid) and salty (NaCl). Similarly, pain clusters showed no differences in thresholds to other stimuli. Moreover, no clustering was obtained for thresholds to both painful and non-painful stimuli together. Thus, individuals could not be characterized as highly sensitive (or insensitive) to all chemical stimuli no matter of evoking pain. This suggests that pain is primarily a singular sensory perception distinct from others such as olfaction or taste. PMID:21291919

  19. Rowers' high: behavioural synchrony is correlated with elevated pain thresholds.

    PubMed

    Cohen, Emma E A; Ejsmond-Frey, Robin; Knight, Nicola; Dunbar, R I M

    2010-02-23

    Physical exercise is known to stimulate the release of endorphins, creating a mild sense of euphoria that has rewarding properties. Using pain tolerance (a conventional non-invasive assay for endorphin release), we show that synchronized training in a college rowing crew creates a heightened endorphin surge compared with a similar training regime carried out alone. This heightened effect from synchronized activity may explain the sense of euphoria experienced during other social activities (such as laughter, music-making and dancing) that are involved in social bonding in humans and possibly other vertebrates. PMID:19755532

  20. Altered emotionality leads to increased pain tolerance in amyloid beta (Abeta1-40) peptide-treated mice.

    PubMed

    Pamplona, Fabrício A; Pandolfo, Pablo; Duarte, Filipe S; Takahashi, Reinaldo N; Prediger, Rui D S

    2010-09-01

    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the decline in cognitive functions, but it is also related to emotional disturbances. Since pain experience results from a complex integration of sensory, cognitive and affective processes, it is not surprising that AD patients display a distinct pattern of pain responsivity. We evaluated whether mice treated with amyloid beta (Abeta) peptide-thought to be critical in the pathogenesis of AD-exhibit altered pain responses and its relation to altered emotionality. Mice received a single i.c.v. injection of vehicle (PBS) or Abeta fragment (1-40) (400pmol/mice) and after 30 days, they were evaluated in tests of pain (hotplate, footshock-sensitivity), learning/memory (water-maze), emotionality (elevated plus-maze, forced swim) and locomotion (open-field). Abeta(1-40)-treated mice presented similar latencies to the control group in the hotplate test and similar nociceptive flinch threshold in the footshock-sensitivity test. However, they presented an increased jump threshold in footshock-sensitivity, suggesting increased pain tolerance. Altered emotionality was observed in the elevated plus-maze (EPM) and forced-swim tests (FST), suggesting anxiogenic-like and depressive-like states, respectively. A multifactorial principal component analysis (PCA) revealed that jump threshold of the footshock-sensitivity test falls within 'Emotionality' and 'Pain', showing moderate correlation with each one of the components of behavior. Acute treatment with the antidepressant desipramine (10mg/kg, i.p.) reduced the jump threshold (i.e. pain tolerance) and time of immobility in FST (i.e. depressive-like state). Flinch threshold (i.e. pain sensitivity), locomotion and anxiety were not altered with desipramine treatment. These results suggest that Abeta(1-40) peptide increases pain tolerance, but not pain sensitivity in mice, which seems to be linked to alterations in cognitive/emotional components of pain processing. PMID:20363258

  1. Discrepancy between stimulus response and tolerance of pain in Alzheimer disease

    PubMed Central

    Werner, Mads U.; Jensen, Troels Staehelin; Ballegaard, Martin; Andersen, Birgitte Bo; Høgh, Peter; Waldemar, Gunhild

    2015-01-01

    Background: Affective-motivational and sensory-discriminative aspects of pain were investigated in patients with mild to moderate Alzheimer disease (AD) and healthy elderly controls using the cold pressor test tolerance and repetitive stimuli of warmth and heat stimuli, evaluating the stimulus-response function. Methods: A case-control design was applied examining 33 patients with mild to moderate AD dementia and 32 healthy controls with the cold pressor test (4°C). Warmth detection threshold (WDT) and heat pain threshold (HPT) were assessed using 5 stimulations. A stimulus-response function was estimated using 4 incrementally increasing suprathreshold heat stimuli. Results: Cold pressor tolerance was lower in patients with AD dementia than in controls (p = 0.027). There were no significant differences between groups regarding WDT and HPT. Significant successive increases in HPT assessments indicated habituation (p < 0.0001), which was similar in the 2 groups (p = 0.85). A mixed model for repeated measures demonstrated that pain rating of suprathreshold stimuli depended on HPT (p = 0.0004) and stimulus intensity (p < 0.0001). Patients with AD dementia had significantly lower increases in pain ratings than controls during suprathreshold stimulation (p = 0.0072). Conclusion: Our results indicate that AD dementia is not associated with a propensity toward development of sensitization or a lack of habituation, suggesting preservation of sensory-discriminative aspects of pain perception. The results further suggest that the attenuated cold pressor pain tolerance may relate to impairment of coping abilities. Paradoxically, we found an attenuated stimulus-response function, compared to controls, suggesting that AD dementia interferes with pain ratings over time, most likely due to memory impairment. PMID:25788560

  2. Pain neurophysiology education improves cognitions, pain thresholds, and movement performance in people with chronic whiplash: a pilot study.

    PubMed

    Van Oosterwijck, Jessica; Nijs, Jo; Meeus, Mira; Truijen, Steven; Craps, Julie; Van den Keybus, Nick; Paul, Lorna

    2011-01-01

    Chronic whiplash is a debilitating condition characterized by increased sensitivity to painful stimuli, maladaptive illness beliefs, inappropriate attitudes, and movement dysfunctions. Previous work in people with chronic low back pain and chronic fatigue syndrome indicates that pain neurophysiology education is able to improve illness beliefs and attitudes as well as movement performance. This single-case study (A-B-C design) with six patients with chronic whiplash associated disorders (WAD) was aimed at examining whether education about the neurophysiology of pain is accompanied by changes in symptoms, daily functioning, pain beliefs, and behavior. Periods A and C represented assessment periods, while period B consisted of the intervention (pain neurophysiology education). Results showed a significant decrease in kinesiophobia (Tampa Scale for Kinesiophobia), the passive coping strategy of resting (Pain Coping Inventory), self-rated disability (Neck Disability Index), and photophobia (WAD Symptom List). At the same time, significantly increased pain pressure thresholds and improved pain-free movement performance (visual analog scale on Neck Extension Test and Brachial Plexus Provocation Test) were established. Although the current results need to be verified in a randomized, controlled trial, they suggest that education about the physiology of pain is able to increase pain thresholds and improve pain behavior and pain-free movement performance in patients with chronic WAD. PMID:21328162

  3. Intrathecal rapamycin attenuates morphine-induced analgesic tolerance and hyperalgesia in rats with neuropathic pain

    PubMed Central

    Xu, Ji-Tian; Sun, Linlin; Lutz, Brianna Marie; Bekker, Alex; Tao, Yuan-Xiang

    2015-01-01

    Repeated and long-term administration of opioids is often accompanied by the initiation of opioid-induced analgesic tolerance and hyperalgesia in chronic pain patients. Our previous studies showed that repeated intrathecal morphine injection activated the mammalian target of rapamycin complex 1 (mTORC1) in spinal dorsal horn neurons and that blocking this activation prevented the initiation of morphine-induced tolerance and hyperalgesia in healthy rats. However, whether spinal mTORC1 is required for morphine-induced tolerance and hyperalgesia under neuropathic pain conditions remains elusive. We here observed the effect of intrathecal infusion of rapamycin, a specific mTORC1 inhibitor, on morphine-induced tolerance and hyperalgesia in a neuropathic pain model in rats induced by the fifth lumbar spinal nerve ligation (SNL). Continuous intrathecal infusion of morphine for one week starting on day 8 post-SNL led to morphine tolerance demonstrated by morphine-induced reduction in maximal possible analgesic effect (MPAE) to tail heat stimuli and ipsilateral paw withdrawal threshold (PWT) to mechanical stimuli in SNL rats. Such reduction was attenuated by co-infusion of rapamycin. Co-infusion of rapamycin also blocked morphine tolerance demonstrated by attenuation of morphine-induced reduction in MPAE in sham rats and morphine-induced hyperalgesia demonstrated by the reverse of morphine-induced reduction in PWT on both sides of sham rats and on the contralateral side of SNL rats. The results suggest that mTORC1 inhibitors could serve as promising medications for use as adjuvants with opioids in clinical neuropathic pain management. PMID:26339682

  4. Quantitative sensory testing and pain tolerance in patients with mild to moderate Alzheimer disease compared to healthy control subjects.

    PubMed

    Jensen-Dahm, Christina; Werner, Mads U; Dahl, Jørgen B; Jensen, Troels Staehelin; Ballegaard, Martin; Hejl, Anne-Mette; Waldemar, Gunhild

    2014-08-01

    Patients with Alzheimer disease (AD) report pain less frequently than their cognitively intact peers. It has been hypothesized that pain processing is altered in AD. The aim of this study was to investigate agreement and reliability of 3 pain sensitivity tests and to examine pain threshold and tolerance in patients with AD. We examined 29 patients with mild to moderate AD and 29 age- and gender-matched healthy control subjects with quantitative sensory testing, ie, assessments of detection threshold (warmth detection threshold [WDT]) and pain threshold (heat pain threshold [HPT], pressure algometry, cold pressor test), and assessments of tolerance (pressure algometry, cold pressor test). All procedures were done twice on day 1, 1 hour apart, and repeated on day 2. We found no difference between groups for WDT (patient vs control subjects: mean [95% confidence interval]: 35.5°C [33.4°C to 37.6°C] vs 35.4°C [34.3°C to 36.5°C], P=.8) or HPT (41.2°C [40.0°C to 42.4°C] vs 42.3°C [41.1°C to 43.5°C], P=.24). We observed comparable thresholds for pressure algometry (median [25% to 75% interquartile range]: 120 kPa [100 to 142 kPa] vs 131 kPa [113 to 192 kPa], P=.10), but significantly lower tolerance in AD patients (213 kPa [188 to 306 kPa] vs 289 kPa [262 to 360 kPa], P=.008). No differences were found for the cold pressor test. The study demonstrated good replicability of the sensory testing data with comparable data variability, for both groups, which supports the use of these methods in studies of patients with mild to moderate AD. Contrary to previous studies, we observed a reduced pain tolerance in patients with mild to moderate AD, which suggests that the reduced report of pain cannot be explained by reduced processing of painful stimuli. PMID:24412285

  5. Association of increased pain threshold by noise with central opioid neurons.

    PubMed

    Chen, Yuh-Fung; Chiang, Hsiu-Mei; Tsai, Yao-Tsung; Tsai, Huei-Yann

    2009-04-30

    Several studies indicated that stress would induce analgesia. Noise, one of the stressors, was assumed to be one of the elements to enhance the threshold of pain tolerance. Since noise might affect human's daily life, it is important to know the mechanism underlying this phenomenon. The objective of this study was to explore the possible mechanism which was trying to explain how the noise affects central nervous system and the possible relationship between this effect and the involvement of opioid neurons. In the preliminary study, the analgesic effect was corroborated in ICR mice in a formalin study. The results are as follows: [1] Naloxone (a micro-opioid receptor antagonist; 1 mg/kg, i.p.), beta-FNA (a delta-opioid receptor antagonist; 5, 10 mg, i.c.v.) and naltrindole (a delta-opioid receptor antagonist; 1, 5 mg/kg, i.p.) were found to reduce antinociceptive effect. [2] nor-BNI (a kappa-antagonist; 1 microg, i.c.v.) had much effect on noise induced analgesic. In conclusion, this study suggests that noise stress enhanced the threshold of analgesia, which might be related to micro- and delta-opioid receptors in the central nervous system. PMID:19764344

  6. A Novel Quantitative Pain Assessment Instrument That Provides Means of Comparing Patient’s Pain Magnitude With a Measurement of Their Pain Tolerance

    PubMed Central

    Johnson, Lanny L.; Pittsley, Andrew; Becker, Ruth; Young, Allison De

    2015-01-01

    Background Traditional pain assessment instruments are subjective in nature. They are limited to subjective reporting of the presence and magnitude of pain. There is no means of validating their response or assessing their pain tolerance. The objective of this study was to determine the potential value of a novel addition to the traditional physical examination concerning a patient’s pain and more importantly their pain tolerance. Methods Extensive preliminary data were collected on 359 consecutive private practice knee patients referable the subject’s pain, including the magnitude, the most pain ever experienced, and their opinion of personal pain tolerance. The novel evaluation included physical testing of a series of small ball drops through a vertical tube from various fixed levels on the index finger and patella. The patient’s response to this impact testing provided quantitative information, from which a comparison was made to their pain opinion and also to that of other patients with similar demographics. Results Nine percent of the patients rated their pain tolerance below the midpoint on the visual analog scale. Seventy-one percent thought they were above the midpoint on the scale in regards to pain tolerance. There were discrepancies in both directions between the subject’s opinion on pain tolerance and their rating of their pain experience to the ball drop testing. Twenty-eight percent of the entire patient group rated themselves above 5 on tolerance, but experienced above the average discomfort compared to other subjects reporting on the finger impact testing. Conclusions This report introduces a novel method for collecting data concerning pain that can be subjected to quantification. The database included quantitative measures providing the opportunity to confirm, validate or refute the patient’s assertions concerning pain magnitude and tolerance. This method is best described as a patient pain profile. It has the potential to give both the patient and the physician quantified objective information rendering insight not otherwise available. PMID:26346200

  7. The relationship between pain tolerance and trait aggression: effects of sex and gender role.

    PubMed

    Reidy, Dennis E; Dimmick, Katie; MacDonald, Kate; Zeichner, Amos

    2009-01-01

    The literature on pain and aggression has indicated that pain elicits aggression. However, research has generally examined pain as a situational variable and focused less on the dispositional ability of an individual to tolerate pain. The dearth of research on pain tolerance and aggression appears to contradict the existing theory on the aggression-eliciting effect of pain, in that studies have found a positive relationship between pain tolerance and aggression. The purpose of this study was to determine whether the relationship between pain tolerance and aggression is moderated by sex and whether the positive relationship could be explained by masculine gender role conformity. A sample of 195 collegiate men and women completed trait measures and a laboratory assessment of pain tolerance. Results indicated that correlations between pain tolerance and trait aggression were significant and positive for men but not women. However, when men's conformity to masculine gender role was controlled for, the relationship between pain tolerance and trait aggression was nil and nonsignificant. Results are discussed in reference to socialization and maintenance of masculine status. PMID:19606461

  8. Pubertal status moderates the association between mother and child laboratory pain tolerance

    PubMed Central

    Tsao, Jennie CI; Li, Ning; Parker, Delana; Seidman, Laura C; Zeltzer, Lonnie K

    2014-01-01

    BACKGROUND: There is limited information regarding the relationship between parent and child responses to laboratory pain induction in the absence of experimental manipulation. OBJECTIVES: To assess the association between responses to cold and pressure pain tasks in 133 nonclinical mothers and children (mean age 13.0 years; 70 girls), and the moderating effects of child sex and pubertal status on these mother-child relationships. METHODS: Mothers and children independently completed the cold and pressure pain tasks. Multiple linear regression analyses examined the association between mothers’ and children’s laboratory pain responses. The moderating effects of child sex and pubertal status were tested in the linear models by examining the interaction among mother laboratory pain responses, and child sex and pubertal status. RESULTS: Mothers’ cold pain anticipatory anxiety and pressure pain intensity were associated with children’s pressure pain anticipatory anxiety. Mothers’ pressure pain tolerance was associated with children’s pain tolerance for both the cold and pressure pain tasks. Mothers’ cold pain tolerance was associated with children’s pressure pain tolerance. Pubertal status moderated two of the three significant mother-child pain tolerance relationships, such that the associations held for early pubertal but not for late pubertal children. Sex did not moderate mother-child pain associations. CONCLUSIONS: The results indicate that mother-child pain relationships are centred primarily on pain avoidance behaviour, particularly among prepubertal children. These findings may inform interventions focused on pain behaviours, with a particular emphasis on mothers of prepubertal children, to reduce acute pain responses in their children. PMID:24367794

  9. The immediate effects of sigmoid colon manipulation on pressure pain thresholds in the lumbar spine.

    PubMed

    McSweeney, Terence P; Thomson, Oliver P; Johnston, Ross

    2012-10-01

    Visceral manual therapy is increasingly used by UK osteopaths and manual therapists, but there is a paucity of research investigating its underlying mechanisms, and in particular in relation to hypoalgesia. The aim of this study was to investigate the immediate effects of osteopathic visceral mobilisation on pressure pain thresholds. A single-blinded, randomised, within subjects, repeated measures design was conducted on 15 asymptomatic subjects. Pressure pain thresholds were measured at the L1 paraspinal musculature and 1st dorsal interossei before and after osteopathic visceral mobilisation of the sigmoid colon. The results demonstrated a statistically significant improvement in pressure pain thresholds immediately after the intervention (P<0.001). This effect was not observed to be systemic, affecting only the L1 paraspinal musculature. This novel study provides new experimental evidence that visceral manual therapy can produce immediate hypoalgesia in somatic structures segmentally related to the organ being mobilised, in asymptomatic subjects. PMID:23036875

  10. Sensibility Threshold in Depressive and Nondepressive Patients with Chronic Orofacial Pain

    PubMed Central

    Hampf, Göran; Aalberg, Veikko; Ekholm, Anita; Vikkula, Juhani

    1988-01-01

    Sensibility threshold was measured in patients with depressive and nondepressive psychiatric disorders, where both groups were suffering from chronic orofacial pain. The control patients had no pain and no signs of mental disturbance. Patients with major depressive disorders had a significantly lower sensibility threshold than patients with milder depressive disorders, while patients with milder depressive disorders had a significantly lower sensibility threshold than patients with nondepressive mental disorders. The controls had the highest sensibility threshold. Plasma, β-endorphin, cortisol and prolactin levels were also measured. The depressed patients were found to have a lower serum β-endorphin level than the nondepressive patients and the controls, although the difference was not statistically significant. PMID:19598700

  11. Decreased pain threshold and enhanced synaptic transmission in the anterior cingulate cortex of experimental hypothyroidism mice

    PubMed Central

    2014-01-01

    Background Thyroid hormones are essential for the maturation and functions of the central nervous system. Pain sensitivity is related to the thyroid status. However, information on how thyroid hormones affect pain processing and synaptic transmission in the anterior cingulate cortex (ACC) is limited. Nociceptive threshold and synaptic transmission in the ACC were detected in the experimental hypothyroidism (HT) mice. Results HT was induced by methimazole and potassium perchlorate in distilled drinking water for 4 weeks. The threshold of pain perception to hot insults, but not mechanical ones, decreased in hypothyroid mice. After treatment with tri-iodothyronine (T3) or thyroxine (T4) for 2 weeks, thermal pain threshold recovered. Electrophysiological recordings revealed enhanced glutamatergic synaptic transmission and reduced GABAergic synaptic transmission in the ACC. Supplementation with T3 or T4 significantly rescued this synaptic transmission imbalance. In the same model, HT caused the up-regulation of the GluR1 subunit of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor and NR2B-containing N-methyl-D-aspartate receptors, but it down-regulated γ-aminobutyric acid A receptors in the ACC. Supplementation with T3 or T4 notably recovered the levels of above proteins. Conclusions These results suggest that HT promotes hypersensitivity to noxious thermal, and that supplementation with T3 or T4 rescues the imbalance between excitatory and inhibitory transmission in the ACC. PMID:24943008

  12. The role of experiential avoidance in acute pain tolerance: a laboratory test.

    PubMed

    Feldner, Matthew T; Hekmat, Hamid; Zvolensky, Michael J; Vowles, Kevin E; Secrist, Zachary; Leen-Feldner, Ellen W

    2006-06-01

    The present investigation examined the role of experiential avoidance in terms of acute pain tolerance and subsequent recovery. Seventy nonclinical participants completed the Acceptance and Action Questionnaire and underwent a well-established cold pressor task. Results indicated that individuals reporting higher levels of experiential avoidance had lower pain endurance and tolerance and recovered more slowly from this particular type of aversive event. Consistent with theoretical prediction, these findings suggest that experiential avoidance may play a role in tolerance of acute pain. PMID:15882839

  13. D-Aspartate Modulates Nociceptive-Specific Neuron Activity and Pain Threshold in Inflammatory and Neuropathic Pain Condition in Mice

    PubMed Central

    Boccella, Serena; Vacca, Valentina; Errico, Francesco; Marinelli, Sara; Squillace, Marta; Di Maio, Anna; Vitucci, Daniela; Palazzo, Enza; De Novellis, Vito; Maione, Sabatino; Pavone, Flaminia; Usiello, Alessandro

    2015-01-01

    D-Aspartate (D-Asp) is a free D-amino acid found in the mammalian brain with a temporal-dependent concentration based on the postnatal expression of its metabolizing enzyme D-aspartate oxidase (DDO). D-Asp acts as an agonist on NMDA receptors (NMDARs). Accordingly, high levels of D-Asp in knockout mice for Ddo gene (Ddo?/?) or in mice treated with D-Asp increase NMDAR-dependent processes. We have here evaluated in Ddo?/? mice the effect of high levels of free D-Asp on the long-term plastic changes along the nociceptive pathway occurring in chronic and acute pain condition. We found that Ddo?/? mice show an increased evoked activity of the nociceptive specific (NS) neurons of the dorsal horn of the spinal cord (L4L6) and a significant decrease of mechanical and thermal thresholds, as compared to control mice. Moreover, Ddo gene deletion exacerbated the nocifensive responses in the formalin test and slightly reduced pain thresholds in neuropathic mice up to 7 days after chronic constriction injury. These findings suggest that the NMDAR agonist, D-Asp, may play a role in the regulation of NS neuron electrophysiological activity and behavioral responses in physiological and pathological pain conditions. PMID:25629055

  14. Wireless peripheral nerve stimulation increases pain threshold in two neuropathic rat models.

    PubMed

    Rosellini, Will; Casavant, Reema; Engineer, Navzer; Beall, Patrick; Pierce, David; Jain, Ravi; Dougherty, Patrick M

    2012-06-01

    Neurostimulation approaches including spinal cord and peripheral nerve stimulation are typically used to treat intractable chronic pain in individuals who are refractory to pain medications. Our earlier studies have shown that a voltage controlled capacitive discharge (VCCD) method of stimulation of nerve activation is able to selectively recruit activity in large myelinated nerve fibers. In this study, we were able to wirelessly activate the sciatic nerve using the VCCD waveform. The purpose of this study was to determine whether this waveform can effectively improve two of the most troublesome pain symptoms experienced by patients with chronic neuropathic pain mechanical and cold hyperalgesia. Neuropathic mechanical hyperalgesia was reproduced using the Spinal Nerve Ligation (SNL) rat model whereas cold allodynia was reproduced using the Chronic Constriction Injury (CCI) model in male rats. Von Frey and cold plate tests were used to evaluate paw withdrawal threshold and latency to withdrawal before and after stimulation in experimental and control rats. Paw withdrawal threshold increased significantly compared to post-lesion baseline after VCCD stimulation in SNL rats. We also observed a significant improvement in cold allodynia in the active implant CCI rats after stimulation. These results suggest that the VCCD stimulation using a wireless microstimulator may be effective in the treatment of neuropathic pain. PMID:22487199

  15. Comparison between the reliability levels of manual palpation and pressure pain threshold in children who reported orofacial pain.

    PubMed

    Chaves, Thaís Cristina; Nagamine, Harumi Martins; de Sousa, Letícia Mêlo; de Oliveira, Anamaria Siriani; Grossi, Débora Bevilaqua

    2010-10-01

    The aim of this study was to compare the intra- and inter-rater reliability of pressure pain threshold (PPT) and manual palpation (MP) of orofacial structures in symptomatic and symptom-free children for temporomandibular disorders (TMD). Fourteen children reporting pain in masticatory muscles or the temporomandibular joint and 16 symptom-free children were randomly assessed on three different occasions: by rater-1 in the first and third session and by rater-2 in the second session. The trained raters applied algometry and MP as recommended by the Research Diagnostic Criteria for TMD. Intraclass correlation coefficients and the Kappa statistic were used to assess the levels of reliability of PPT and MP, respectively. Excellent intra- and inter-rater reliability levels were observed for PPT values at most of the examined sites for symptom-free children and excellent and moderate reliability levels for children reporting pain. For MP, moderate and poor intra-rater and inter-rater reliability levels were observed for most sites in both groups. Algometry showed higher reliability levels for both groups of children and is recommended for pain assessment in children in association with MP. PMID:20430686

  16. Effects of MHz ultrasound on electrical pain threshold perception in humans.

    PubMed

    Williams, A R; McHale, J; Bowditch, M; Miller, D L; Reed, B

    1987-05-01

    An electrode system was developed consisting of two 8 mm long 0.2 mm diameter silver-coated copper wires arranged parallel to each other 8 mm apart and held in contact with the skin by means of an acoustically transparent plastic adhesive tape. This system was attached to the upper arms of young adult volunteers who increased the voltage of the rectangular electrical pulses supplied to the electrodes until a reproducible sharp prickling pain sensation was perceived. A one inch diameter physiotherapy transducer was positioned over the electrode site so that ultrasound could be administered throughout the measurement period. The experiments were performed single blind to eliminate any subjective bias on the part of the volunteers. Preliminary experiments established that highly reproducible (+/- 3 to 4%) pain threshold perception values could be obtained, and that these values were not affected by changes in (a) the duration of the "on" time of the electrical pulses between 1.5 and 48 ms, (b) the contact pressure between the transducer and the electrode site, (c) the time interval between successive threshold measurements (providing that an unacceptable level of oedema was not produced around the electrodes), and (d) whether or not a test measurement was preceded by a control. Ultrasound exposure via a direct contact technique consistently produced a statistically significant (p less than 0.05) decrease in the perception threshold for electrical pain. This effect usually developed within 30-60 s and its magnitude increased both with increasing intensity (rising to 20.7 +/- 0.57% at an SATA intensity of 0.43 W/cm2 at 1.1 MHz) and with increasing frequency at the same ultrasonic intensity. Delivering the same amount of ultrasonic energy in the form of 2 ms bursts at several different peak intensities produced exactly the same reduction in pain threshold perception. These results indicate a thermal interaction mechanism, and similar threshold changes could be obtained by heating or cooling the electrode site by nonacoustic means. The inclusion of a thermocouple junction between the electrode wires showed that temperature increases of up to 10 degrees C could be produced when the transducer was in direct contact with the tape over the electrodes. The volunteers were not aware of these temperature increases which were primarily caused by heating of the transducer face. If the temperature of the skin surface is kept constant by interposing a thermostatted water path between the transducer and the electrode system, then similar ultrasound exposures had no detectable effects upon the electrical pain perception threshold.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3303584

  17. Microscopic quantum dynamics study on the noise threshold of fault-tolerant quantum error correction

    SciTech Connect

    Cheng, Y.C.; Silbey, R.J.

    2005-07-15

    Quantum circuits implementing fault-tolerant quantum error correction (QEC) for the three-qubit bit-flip code and five-qubit code are studied. To describe the effect of noise, we apply a model based on a generalized effective Hamiltonian where the system-environment interactions are taken into account by including stochastic fluctuating terms in the system Hamiltonian. This noise model enables us to investigate the effect of noise in quantum circuits under realistic device conditions and avoid strong assumptions such as maximal parallelism and weak storage errors. Noise thresholds of the QEC codes are calculated. In addition, the effects of imprecision in projective measurements, collective bath, fault-tolerant repetition protocols, and level of parallelism in circuit constructions on the threshold values are also studied with emphasis on determining the optimal design for the fault-tolerant QEC circuit. These results provide insights into the fault-tolerant QEC process as well as useful information for designing the optimal fault-tolerant QEC circuit for particular physical implementation of quantum computer.

  18. Overcoming pain thresholds with multilevel models—an example using quantitative sensory testing (QST) data

    PubMed Central

    Blankenburg, Markus R.; Süß, Moritz; Zernikow, Boris

    2015-01-01

    The assessment of somatosensory function is a cornerstone of research and clinical practice in neurology. Recent initiatives have developed novel protocols for quantitative sensory testing (QST). Application of these methods led to intriguing findings, such as the presence lower pain-thresholds in healthy children compared to healthy adolescents. In this article, we (re-) introduce the basic concepts of signal detection theory (SDT) as a method to investigate such differences in somatosensory function in detail. SDT describes participants’ responses according to two parameters, sensitivity and response-bias. Sensitivity refers to individuals’ ability to discriminate between painful and non-painful stimulations. Response-bias refers to individuals’ criterion for giving a “painful” response. We describe how multilevel models can be used to estimate these parameters and to overcome central critiques of these methods. To provide an example we apply these methods to data from the mechanical pain sensitivity test of the QST protocol. The results show that adolescents are more sensitive to mechanical pain and contradict the idea that younger children simply use more lenient criteria to report pain. Overall, we hope that the wider use of multilevel modeling to describe somatosensory functioning may advance neurology research and practice. PMID:26557435

  19. The effects of smartphone use on upper extremity muscle activity and pain threshold

    PubMed Central

    Lee, Minkyung; Hong, Yunkyung; Lee, Seunghoon; Won, Jinyoung; Yang, Jinjun; Park, Sookyoung; Chang, Kyu-Tae; Hong, Yonggeun

    2015-01-01

    [Purpose] The purpose of this study was to determine whether muscle activity and pressure-induced pain in the upper extremities are affected by smartphone use, and to compare the effects of phone handling with one hand and with both hands. [Subjects] The study subjects were asymptomatic women 20–22 years of age. [Methods] The subjects sat in a chair with their feet on the floor and the elbow flexed, holding a smartphone positioned on the thigh. Subsequently, the subjects typed the Korean anthem for 3 min, one-handed or with both hands. Each subject repeated the task three times, with a 5-min rest period between tasks to minimize fatigue. Electromyography (EMG) was used to record the muscle activity of the upper trapezius (UT), extensor pollicis longus (EPL), and abductor pollicis (AP) during phone operation. We also used a dolorimeter to measure the pressure-induced pain threshold in the UT. [Results] We observed higher muscle activity in the UT, AP, and EPL in one-handed smartphone use than in its two-handed use. The pressure-induced pain threshold of the UT was lower after use of the smartphone, especially after one-handed use. [Conclusion] Our results show that smartphone operation with one hand caused greater UT pain and induced increased upper extremity muscle activity. PMID:26180311

  20. The effects of smartphone use on upper extremity muscle activity and pain threshold.

    PubMed

    Lee, Minkyung; Hong, Yunkyung; Lee, Seunghoon; Won, Jinyoung; Yang, Jinjun; Park, Sookyoung; Chang, Kyu-Tae; Hong, Yonggeun

    2015-06-01

    [Purpose] The purpose of this study was to determine whether muscle activity and pressure-induced pain in the upper extremities are affected by smartphone use, and to compare the effects of phone handling with one hand and with both hands. [Subjects] The study subjects were asymptomatic women 20-22?years of age. [Methods] The subjects sat in a chair with their feet on the floor and the elbow flexed, holding a smartphone positioned on the thigh. Subsequently, the subjects typed the Korean anthem for 3?min, one-handed or with both hands. Each subject repeated the task three times, with a 5-min rest period between tasks to minimize fatigue. Electromyography (EMG) was used to record the muscle activity of the upper trapezius (UT), extensor pollicis longus (EPL), and abductor pollicis (AP) during phone operation. We also used a dolorimeter to measure the pressure-induced pain threshold in the UT. [Results] We observed higher muscle activity in the UT, AP, and EPL in one-handed smartphone use than in its two-handed use. The pressure-induced pain threshold of the UT was lower after use of the smartphone, especially after one-handed use. [Conclusion] Our results show that smartphone operation with one hand caused greater UT pain and induced increased upper extremity muscle activity. PMID:26180311

  1. What Color is My Arm? Changes in Skin Color of an Embodied Virtual Arm Modulates Pain Threshold

    PubMed Central

    Martini, Matteo; Perez-Marcos, D.; Sanchez-Vives, M. V.

    2013-01-01

    It has been demonstrated that visual inputs can modulate pain. However, the influence of skin color on pain perception is unknown. Red skin is associated to inflamed, hot and more sensitive skin, while blue is associated to cyanotic, cold skin. We aimed to test whether the color of the skin would alter the heat pain threshold. To this end, we used an immersive virtual environment where we induced embodiment of a virtual arm that was co-located with the real one and seen from a first-person perspective. Virtual reality allowed us to dynamically modify the color of the skin of the virtual arm. In order to test pain threshold, increasing ramps of heat stimulation applied on the participants’ arm were delivered concomitantly with the gradual intensification of different colors on the embodied avatar’s arm. We found that a reddened arm significantly decreased the pain threshold compared with normal and bluish skin. This effect was specific when red was seen on the arm, while seeing red in a spot outside the arm did not decrease pain threshold. These results demonstrate an influence of skin color on pain perception. This top-down modulation of pain through visual input suggests a potential use of embodied virtual bodies for pain therapy. PMID:23914172

  2. Cervical lateral glide increases nociceptive flexion reflex threshold but not pressure or thermal pain thresholds in chronic whiplash associated disorders: A pilot randomised controlled trial.

    PubMed

    Sterling, Michele; Pedler, Ashley; Chan, Cliffton; Puglisi, Madonna; Vuvan, Viana; Vicenzino, Bill

    2010-04-01

    Sensory hypersensitivity indicative of augmented central pain processing is a feature of chronic whiplash associated disorders (WAD). This study investigated the immediate effects of a cervical spine manual therapy (SMT) technique on measures of central hyperexcitability. In a randomised, single blind, clinical trial, 39 participants with chronic WAD were randomly assigned to a cervical SMT (lateral glide) or manual contact intervention. The Neck Disability Index (NDI) and GHQ-28 were administered at baseline. Pressure pain thresholds (PPTs), thermal pain thresholds (TPTs) and Nociceptive Flexion Reflex (NFR) responses (threshold and VAS of pain) were measured pre and post intervention. There was a significantly greater increase in NFR threshold following SMT compared to the manual contact intervention (p = 0.04). PPTs at the cervical spine increased following both SMT (mean +/- SE: 24.1 +/- 7.3%) and manual contact (21 +/- 8.4%) with no difference between interventions. There was no difference between interventions for pain ratings with the NFR test, PPTs at the Median Nerve or Tibialis Anterior, heat or cold TPT. SMT may be effective in reducing spinal hyperexcitability in chronic WAD. PMID:19884037

  3. Evaluation of thermal, pain, and vibration sensation thresholds in newly diagnosed type 1 diabetic patients.

    PubMed Central

    Ziegler, D; Mayer, P; Gries, F A

    1988-01-01

    Small and large fibre function was studied in 40 non-ketotic, newly diagnosed Type 1 diabetic patients and 48 age-matched controls, using 12 quantitative tests for assessment of cutaneous sensation. Patients were aged 10-39 years and had been treated with insulin for 4-31 days. Thermal discrimination (foot), warm and cold thermal perception (thenar eminence and foot), and heat and cold pain perception thresholds (thenar eminence) were significantly elevated in the patients as compared with the controls (p less than 0.05 to p less than 0.001). No significant differences in thermal discrimination (thenar), heat and cold pain perception (foot), and metacarpal as well as malleolar vibration perception thresholds were noted between the groups. The rates of abnormalities among the individual tests ranged from 0% to 27.5%, being lowest for vibration perception and highest for thermal perception thresholds after cold stimuli. The results in nine of 12 tests correlated significantly with age, but only two were related to HbA1c. Thus, sensory neural functions transmitted by small fibres, but not those transmitted by large fibres, were impaired in newly diagnosed Type 1 diabetics after the correction of initial ketosis and hyperglycaemia. Cooling perception tests were most sensitive in detecting abnormality. An age-related involvement of different small fibre functions was present in these patients. PMID:3236020

  4. Latitudinal variation in thermal tolerance thresholds of early life stages of corals

    NASA Astrophysics Data System (ADS)

    Woolsey, E. S.; Keith, S. A.; Byrne, M.; Schmidt-Roach, S.; Baird, A. H.

    2015-06-01

    Organisms living in habitats characterized by a marked seasonal temperature variation often have a greater thermal tolerance than those living in more stable habitats. To determine the extent to which this hypothesis applies to reef corals, we compared thermal tolerance of the early life stages of five scleractinian species from three locations spanning 17° of latitude along the east coast of Australia. Embryos were exposed to an 8 °C temperature range around the local ambient temperature at the time of spawning. Upper thermal thresholds, defined as the temperature treatment at which the proportion of abnormal embryos or median life span was significantly different to ambient controls, varied predictably among locations. At Lizard Island, the northern-most site with the least annual variation in temperature, the proportion of abnormal embryos increased and life span decreased 2 °C above ambient in the two species tested. At two southern sites, One Tree Island and Lord Howe Island, where annual temperature variation was greater, upper temperature thresholds were generally 4 °C or greater above ambient for both variables in the four species tested. The absolute upper thermal threshold temperature also varied among locations: 30 °C at Lizard Island; 28 °C at One Tree Island; 26 °C at Lord Howe Island. These results support previous work on adult corals demonstrating predictable differences in upper thermal thresholds with latitude. With projected ocean warming, these temperature thresholds will be exceeded in northern locations in the near future, adding to a growing body of evidence indicating that climate change is likely to be more detrimental to low latitude than high latitude corals.

  5. Tactile, thermal, and electrical thresholds in patients with and without phantom limb pain after traumatic lower limb amputation

    PubMed Central

    Li, Shengai; Melton, Danielle H; Li, Sheng

    2015-01-01

    Purpose To examine whether there is central sensitization in patients with phantom limb pain (PLP) after traumatic limb amputation. Methods Seventeen patients after unilateral lower limb amputation secondary to trauma were enrolled. Ten patients had chronic PLP, while the other seven patients had no PLP. Tactile-sensation threshold, cold- and warm-sensation thresholds, cold- and heat-pain thresholds, electrical-sensation threshold (EST), and electrical-pain threshold on the distal residual limb and the symmetrical site on the sound limb were measured in all tested patients. Their thresholds were compared within the PLP and non-PLP group, and between the groups. Results The novel findings included: 1) electrical-pain threshold was only decreased in the sound limb in the PLP group and there was no difference between two limbs in the non-PLP group, suggesting central sensitization in patients with PLP; and 2) EST was increased on the affected limb as compared to the sound limb within the PLP group, but there were no significant differences in EST between the PLP and non-PLP group. There were in general no significant differences in other tested thresholds within the groups and between groups. Conclusion Our results demonstrate central sensitization in the patients with PLP after traumatic limb amputation. PMID:25945065

  6. Pressure pain threshold of mucosa after tooth extraction under removable denture bases.

    PubMed

    Suzuki, Y; Katoh, M; Sato, J; Morokuma, M; Hosoi, M A; Ohkubo, C

    2011-12-01

    This study explored the pressure pain threshold (PPT) of the mucosa after tooth extraction. The PPTs of the wounded mucosa of eight volunteer subjects were observed at 7, 30, and 90 days after tooth extraction. The PPTs at 30 days and 90 days were approximately two and three times higher respectively, than those at 7 days. As time passed, the values for the PPTs after tooth extraction increased in all regions. At 90 days after tooth extraction, the PPTs are about 97% recovered compared to the PPTs of the contralateral points. PMID:22645806

  7. Synchrony and exertion during dance independently raise pain threshold and encourage social bonding

    PubMed Central

    Tarr, Bronwyn; Launay, Jacques; Cohen, Emma; Dunbar, Robin

    2015-01-01

    Group dancing is a ubiquitous human activity that involves exertive synchronized movement to music. It is hypothesized to play a role in social bonding, potentially via the release of endorphins, which are analgesic and reward-inducing, and have been implicated in primate social bonding. We used a 2 × 2 experimental design to examine effects of exertion and synchrony on bonding. Both demonstrated significant independent positive effects on pain threshold (a proxy for endorphin activation) and in-group bonding. This suggests that dance which involves both exertive and synchronized movement may be an effective group bonding activity. PMID:26510676

  8. Synchrony and exertion during dance independently raise pain threshold and encourage social bonding.

    PubMed

    Tarr, Bronwyn; Launay, Jacques; Cohen, Emma; Dunbar, Robin

    2015-10-01

    Group dancing is a ubiquitous human activity that involves exertive synchronized movement to music. It is hypothesized to play a role in social bonding, potentially via the release of endorphins, which are analgesic and reward-inducing, and have been implicated in primate social bonding. We used a 2 2 experimental design to examine effects of exertion and synchrony on bonding. Both demonstrated significant independent positive effects on pain threshold (a proxy for endorphin activation) and in-group bonding. This suggests that dance which involves both exertive and synchronized movement may be an effective group bonding activity. PMID:26510676

  9. Spatial discrimination thresholds for pain and touch in human hairy skin.

    PubMed

    Schlereth, T; Magerl, W; Treede, R

    2001-05-01

    The traditional concept that pain is poorly localized has been challenged by recent studies, where subjects were able to point to the stimulated spot on the skin with an accuracy of 10-20 mm. Pointing movements themselves, however, have errors of about 15 mm. To determine the limits of sensory performance of the nociceptive system independent of motor performance, point localization of heat pain (540 mJ punctate laser stimuli, 5 mm diameter), mechanical pain (256 mN punctate probe, 200 microm diameter), and touch (16 mN von Frey probe, 1.1 mm diameter) were tested in a two-alternative forced-choice paradigm in 12 healthy subjects. Stimuli were applied in randomized order to two parallel lines on the back of the hand (4-32 mm distance). The cumulative distribution functions for correct localization were of similar sigmoid shape for all test stimuli, indicating logarithmic normal distributions. The 75% correct localization threshold for painful heat was 8.6 mm (3.1 +/- 0.1 log2 units) and did not differ significantly from that of non-painful touch (9.0 mm, 3.2+/-0.2 log2 units). Localization of mechanically-induced pain (5.1 mm, 2.4 +/- 0.2 log2 units) was significantly more accurate than both heat pain and touch, possibly due to a synergism of two different sensory channels, the tactile channel and the nociceptive channel, which were activated simultaneously. For all three stimuli, discrimination was significantly better in radial-ulnar compared to proximal-distal direction, which might be related to oval receptive field shapes. Sequential spatial discrimination for touch was significantly better than simultaneous spatial discrimination tested with a grating orientation task (18.9 mm), but both were one order of magnitude worse than at the finger tip (1.3 mm, 0.4 +/- 0.1 log2 units). In conclusion, pain evoked by radiant heat pulses and touch evoked by von Frey probes were localized with similar precision on the back of the hand. These findings indicate that outside the tactile fovea at finger tips or lips the spatial discrimination capacities of the nociceptive and tactile systems are about equal. PMID:11323139

  10. The growth threshold conjecture: a theoretical framework for understanding T-cell tolerance.

    PubMed

    Arias, Clemente F; Herrero, Miguel A; Cuesta, José A; Acosta, Francisco J; Fernández-Arias, Cristina

    2015-07-01

    Adaptive immune responses depend on the capacity of T cells to target specific antigens. As similar antigens can be expressed by pathogens and host cells, the question naturally arises of how can T cells discriminate friends from foes. In this work, we suggest that T cells tolerate cells whose proliferation rates remain below a permitted threshold. Our proposal relies on well-established facts about T-cell dynamics during acute infections: T-cell populations are elastic (they expand and contract) and they display inertia (contraction is delayed relative to antigen removal). By modelling inertia and elasticity, we show that tolerance to slow-growing populations can emerge as a population-scale feature of T cells. This result suggests a theoretical framework to understand immune tolerance that goes beyond the self versus non-self dichotomy. It also accounts for currently unexplained observations, such as the paradoxical tolerance to slow-growing pathogens or the presence of self-reactive T cells in the organism. PMID:26587263

  11. The growth threshold conjecture: a theoretical framework for understanding T-cell tolerance

    PubMed Central

    Arias, Clemente F.; Herrero, Miguel A.; Cuesta, José A.; Acosta, Francisco J.; Fernández-Arias, Cristina

    2015-01-01

    Adaptive immune responses depend on the capacity of T cells to target specific antigens. As similar antigens can be expressed by pathogens and host cells, the question naturally arises of how can T cells discriminate friends from foes. In this work, we suggest that T cells tolerate cells whose proliferation rates remain below a permitted threshold. Our proposal relies on well-established facts about T-cell dynamics during acute infections: T-cell populations are elastic (they expand and contract) and they display inertia (contraction is delayed relative to antigen removal). By modelling inertia and elasticity, we show that tolerance to slow-growing populations can emerge as a population-scale feature of T cells. This result suggests a theoretical framework to understand immune tolerance that goes beyond the self versus non-self dichotomy. It also accounts for currently unexplained observations, such as the paradoxical tolerance to slow-growing pathogens or the presence of self-reactive T cells in the organism. PMID:26587263

  12. Winter cold-tolerance thresholds in field-grown Miscanthus hybrid rhizomes

    PubMed Central

    Peixoto, Murilo de Melo; Friesen, Patrick Calvin; Sage, Rowan F.

    2015-01-01

    The cold tolerance of winter-dormant rhizomes was evaluated in diploid, allotriploid, and allotetraploid hybrids of Miscanthus sinensis and Miscanthus sacchariflorus grown in a field setting. Two artificial freezing protocols were tested: one lowered the temperature continuously by 1°C h–1 to the treatment temperature and another lowered the temperature in stages of 24h each to the treatment temperature. Electrolyte leakage and rhizome sprouting assays after the cold treatment assessed plant and tissue viability. Results from the continuous-cooling trial showed that Miscanthus rhizomes from all genotypes tolerated temperatures as low as –6.5 °C; however, the slower, staged-cooling procedure enabled rhizomes from two diploid lines to survive temperatures as low as –14 °C. Allopolyploid genotypes showed no change in the lethal temperature threshold between the continuous and staged-cooling procedure, indicating that they have little ability to acclimate to subzero temperatures. The results demonstrated that rhizomes from diploid Miscanthus lines have superior cold tolerance that could be exploited to improve performance in more productive polyploid lines. With expected levels of soil insulation, low winter air temperatures should not harm rhizomes of tolerant diploid genotypes of Miscanthus in temperate to sub-boreal climates (up to 60°N); however, the observed winter cold in sub-boreal climates could harm rhizomes of existing polyploid varieties of Miscanthus and thus reduce stand performance. PMID:25788733

  13. Influence of intense light stimulation on trigeminal and cervical pain perception thresholds.

    PubMed

    Kowacs, P A; Piovesan, E J; Werneck, L C; Tatsui, C E; Lange, M C; Ribas, L C; da Silva, H P

    2001-04-01

    Thirty-three migraineurs and 23 healthy controls were submitted to pressure algometry before and after light-induced discomfort was elicited by progressive light stimulation in a monoblind fashion. Pressure algometries were performed on the emergence of the supraorbital, infraorbital, mental and greater occipital nerves, and over the temporal muscles, always throughout the same sequence and from right to left. Measurements were carried out before and immediately after light stimulation and after 10 min of the second algometry. The final result for each site measured at each time-point was the mean of the three measurements. Light stimulation was carried out progressively until light-induced discomfort was reported, to a maximum of 20,000 lux. A heat-blocking glass protected patients' eyes. Migraineurs presented significant and persistent drops in pain perception thresholds after light stimulation, at all sites tested (P = 0.002 to < 0.0001). These drops were not seen in controls, in whom, conversely, a less significant increase was seen on right infraorbital and left temporal muscle sites. Our results indicate that in migraineurs, light may have a relevant role in trigeminal and cervical pain perception thresholds. PMID:11442552

  14. Real men are made, not born! Incidental exposure to energy drinks may promote men's tolerance of physical pain.

    PubMed

    Abetkoff, Darren; Karlsson, Torulf; Chiou, Wen-Bin

    2015-12-01

    The energy drink market has grown exponentially since the debut of Red Bull. Advertising of energy drinks tends to reinforce an emphasis on masculine identification. However, no previous study has addressed the symbolic effect of energy drinks on pain tolerance, that is, a particular masculine characteristic. We conducted a priming-based experiment to show that energy drink primes elevated men's pain tolerance. Induced conformity to masculinity norms mediated the priming effect of energy drinks on pain tolerance. These findings suggest that mere reminders of masculinity-related products can lead men to behave accordingly in seemingly irrelevant domains (i.e., pain tolerance). Besides distraction and placebo treatment, the connection between a symbolic masculinity prime and greater tolerance of pain may shed lights on an alternative route for pain control. PMID:26437721

  15. The effects of distraction on exercise and cold pressor tolerance for chronic low back pain sufferers.

    PubMed

    Johnson, M H; Petrie, S M

    1997-01-01

    Distraction has been found to be effective for the attenuation of experimental and acute clinical pain but its efficacy for chronic pain management remains unclear. There are even some suggestions that distraction may be a counterproductive strategy for chronic pain sufferers. In this study we found that a word shadowing distraction task increased the ability of a group of 12 female and eight male chronic low back pain (CLBP) sufferers to carry out a brief (maximum 300 s) step-up exercise that temporarily increased their pain (P < 0.05). This 15% increase in exercise time was not accompanied by an increase in reported pain after the exercise. Interestingly, the same distraction task did not increase the cold pressor (CP) tolerance time for the CLBP group but produced a 26% increase in tolerance time for a pain-free control group consisting of nine females and nine males (P < 0.05). Also, performance on the distraction task during the CP was worse for the CLBP group than the controls (P < 0.05). Although these findings should be interpreted cautiously because of the parameters of the experiment, they do suggest that distraction is a potentially useful technique to assist chronic pain sufferers. PMID:9060011

  16. Virtual-reality distraction and cold-pressor pain tolerance: does avatar point of view matter?

    PubMed

    Dahlquist, Lynnda M; Herbert, Linda J; Weiss, Karen E; Jimeno, Monica

    2010-10-01

    This study tested the effects of distraction using virtual-reality (VR) technology on acute pain tolerance in young adults. Forty-one undergraduate students, aged 18-23 years, used a VR head-mounted display helmet, steering wheel, and foot pedal to play an auto racing video game while undergoing exposure to very cold water (cold pressor set at 1 °C). Two different game views were tested that were hypothesized to affect the degree to which participants felt "present" in the virtual environment: a first-person view, in which the participant saw the virtual environment through the eyes of the game character being manipulated; and a third-person view, in which the participant viewed the game character from a distance. The length of time participants tolerated the cold-water exposure (pain tolerance) under each distraction condition was compared to a baseline (no distraction) trial. Subjects also rated the degree to which they felt "present" in the virtual environment after each distraction trial. Results demonstrated that participants had significantly higher pain tolerance during both VR-distraction conditions relative to baseline (no distraction) trials. Although participants reported a greater sense of presence during the first-person condition than the third-person condition, pain-tolerance scores associated with the two distraction conditions did not differ. The types of VR applications in which presence may be more or less important are discussed. PMID:20950186

  17. Virtual-Reality Distraction and Cold-Pressor Pain Tolerance: Does Avatar Point of View Matter?

    PubMed Central

    Herbert, Linda J.; Weiss, Karen E.; Jimeno, Monica

    2010-01-01

    Abstract This study tested the effects of distraction using virtual-reality (VR) technology on acute pain tolerance in young adults. Forty-one undergraduate students, aged 18–23 years, used a VR head-mounted display helmet, steering wheel, and foot pedal to play an auto racing video game while undergoing exposure to very cold water (cold pressor set at 1°C). Two different game views were tested that were hypothesized to affect the degree to which participants felt “present” in the virtual environment: a first-person view, in which the participant saw the virtual environment through the eyes of the game character being manipulated; and a third-person view, in which the participant viewed the game character from a distance. The length of time participants tolerated the cold-water exposure (pain tolerance) under each distraction condition was compared to a baseline (no distraction) trial. Subjects also rated the degree to which they felt “present” in the virtual environment after each distraction trial. Results demonstrated that participants had significantly higher pain tolerance during both VR-distraction conditions relative to baseline (no distraction) trials. Although participants reported a greater sense of presence during the first-person condition than the third-person condition, pain-tolerance scores associated with the two distraction conditions did not differ. The types of VR applications in which presence may be more or less important are discussed. PMID:20950186

  18. Shared Mechanisms for Opioid Tolerance and a Transition to Chronic Pain

    PubMed Central

    Joseph, Elizabeth K.; Reichling, David B.; Levine, Jon D.

    2010-01-01

    Clinical pain conditions may remain responsive to opiate analgesics for extended periods, but such persistent acute pain can undergo a transition to an opiate-resistant chronic pain state that becomes a much more serious clinical problem. To test the hypothesis that cellular mechanisms of chronic pain in the primary afferent also contribute to the development of opiate resistance, we employed a recently developed model of the transition of from acute to chronic pain, hyperalgesic priming. Repeated intradermal administration of the potent and highly selective μ-opioid agonist, DAMGO, to produce tolerance for its inhibition of prostaglandin E2 (PGE2) hyperalgesia, simultaneously produced hyperalgesic priming. Conversely, injection of an inflammogen, carrageenan, used to produce priming produced DAMGO tolerance. Both effects were prevented by inhibition of protein kinase Cε (PKCε). Carrageenan also induced opioid dependence, manifest as μ-opioid receptor antagonist (CTOP)-induced hyperalgesia that, like priming, was PKCε- and Gi-dependent. These findings suggest that the transition from acute to chronic pain, and development of μ-opioid receptor tolerance and dependence may be linked by common cellular mechanisms in the primary afferent. PMID:20357116

  19. A preliminary report on adjuvant analgesic efficacy of HANS in opioid tolerant patients with cancer pain

    PubMed Central

    Li, Xiaomei; Zhu, Jianhua; Li, Pingping; Zhu, Guangqing; Wu, Xiaoming; Chen, Huoming; Zhao, Huixia; Wang, Wei; Zhang, Ying; Liu, Duanqi

    2014-01-01

    Objective To observe the adjuvant analgesic efficacy of Han’s Acupoint Nerve Stimulator (HANS) in opioid tolerant patients with cancer pain. Methods A prospective non-controlled study was conducted. Opioid tolerant patients with cancer pain were enrolled and treated with both routinely analgesics and adjuvant HANS (2/100 Hz for 30 min/d, 5 d on and 2 d off for two weeks). Cancer pain, quality of life (QOL), anxiety and depression were assessed before enrollment and on d 8 and d 15 with the BPI-C, EORTC QLQ-C30, and self-rating anxiety scale (SAS)/self-rating depression scale (SDS), respectively; the therapeutic frequency of breakthrough pain (BP) and daily opioid dose were also recorded. Results Totally 47 patients meeting the inclusion criteria participated in this study; 43 patients completed the two-week treatment and assessment. The mean scores of patient’s “worst” and “least” pain intensity assessed with BPI-C decreased significantly on d 8 and d 15; the therapeutic frequency of BP also significantly decreased; but the average daily dose of opioids did not change significantly. For the nine symptoms in EORTC QLQ-C30 assessment, the mean scores of pain, fatigue, constipation and insomnia were significantly lower on d 8 and d 15 compared with baseline; the mean scores of the overall health status, nausea/vomiting and the incidence rates of both anxiety and depression also decreased significantly on d 15. Conclusions To opioid tolerant patients with cancer pain, adjuvant treatment with HANS could improve pain release and patients’ QOL by decreasing the severity of pain, fatigue, constipation, insomnia and other concomitant symptoms; it could also decrease the incidence rates of anxiety and depression. PMID:24826058

  20. The body fades away: investigating the effects of transparency of an embodied virtual body on pain threshold and body ownership

    PubMed Central

    Martini, Matteo; Kilteni, Konstantina; Maselli, Antonella; Sanchez-Vives, Maria V.

    2015-01-01

    The feeling of “ownership” over an external dummy/virtual body (or body part) has been proven to have both physiological and behavioural consequences. For instance, the vision of an “embodied” dummy or virtual body can modulate pain perception. However, the impact of partial or total invisibility of the body on physiology and behaviour has been hardly explored since it presents obvious difficulties in the real world. In this study we explored how body transparency affects both body ownership and pain threshold. By means of virtual reality, we presented healthy participants with a virtual co-located body with four different levels of transparency, while participants were tested for pain threshold by increasing ramps of heat stimulation. We found that the strength of the body ownership illusion decreases when the body gets more transparent. Nevertheless, in the conditions where the body was semi-transparent, higher levels of ownership over a see-through body resulted in an increased pain sensitivity. Virtual body ownership can be used for the development of pain management interventions. However, we demonstrate that providing invisibility of the body does not increase pain threshold. Therefore, body transparency is not a good strategy to decrease pain in clinical contexts, yet this remains to be tested. PMID:26415748

  1. The body fades away: investigating the effects of transparency of an embodied virtual body on pain threshold and body ownership.

    PubMed

    Martini, Matteo; Kilteni, Konstantina; Maselli, Antonella; Sanchez-Vives, Maria V

    2015-01-01

    The feeling of "ownership" over an external dummy/virtual body (or body part) has been proven to have both physiological and behavioural consequences. For instance, the vision of an "embodied" dummy or virtual body can modulate pain perception. However, the impact of partial or total invisibility of the body on physiology and behaviour has been hardly explored since it presents obvious difficulties in the real world. In this study we explored how body transparency affects both body ownership and pain threshold. By means of virtual reality, we presented healthy participants with a virtual co-located body with four different levels of transparency, while participants were tested for pain threshold by increasing ramps of heat stimulation. We found that the strength of the body ownership illusion decreases when the body gets more transparent. Nevertheless, in the conditions where the body was semi-transparent, higher levels of ownership over a see-through body resulted in an increased pain sensitivity. Virtual body ownership can be used for the development of pain management interventions. However, we demonstrate that providing invisibility of the body does not increase pain threshold. Therefore, body transparency is not a good strategy to decrease pain in clinical contexts, yet this remains to be tested. PMID:26415748

  2. Phase and Sex Effects in Pain Perception: A Critical Review.

    ERIC Educational Resources Information Center

    Goolkasian, Paula

    1985-01-01

    Reviews the literature in pain perception to clarify the influence of sex and menstrual phase on the phenomenon of pain. The appropriateness of the measures of pain threshold, pain tolerance, discrimination accuracy, and of response bias to the study of pain are discussed. (Author)

  3. The Impact of Demand Characteristics on Brief Acceptance- and Control-Based Interventions for Pain Tolerance

    ERIC Educational Resources Information Center

    Roche, Bryan; Forsyth, John P.; Maher, Elaine

    2007-01-01

    The present analog study compared the effectiveness of an acceptance- and control-based intervention on pain tolerance using a cold pressor task, and is a partial replication and extension of the Hayes, Bissett et al. (Hayes, S. C., Bissett, R.T., Korn, Z., Zettle, R. D., Rosenfarb, I. S., Cooper, L. D., & Grundt, A. M. (1999). "The impact of…

  4. Superconducting quantum circuits at the surface code threshold for fault tolerance.

    PubMed

    Barends, R; Kelly, J; Megrant, A; Veitia, A; Sank, D; Jeffrey, E; White, T C; Mutus, J; Fowler, A G; Campbell, B; Chen, Y; Chen, Z; Chiaro, B; Dunsworth, A; Neill, C; O'Malley, P; Roushan, P; Vainsencher, A; Wenner, J; Korotkov, A N; Cleland, A N; Martinis, John M

    2014-04-24

    A quantum computer can solve hard problems, such as prime factoring, database searching and quantum simulation, at the cost of needing to protect fragile quantum states from error. Quantum error correction provides this protection by distributing a logical state among many physical quantum bits (qubits) by means of quantum entanglement. Superconductivity is a useful phenomenon in this regard, because it allows the construction of large quantum circuits and is compatible with microfabrication. For superconducting qubits, the surface code approach to quantum computing is a natural choice for error correction, because it uses only nearest-neighbour coupling and rapidly cycled entangling gates. The gate fidelity requirements are modest: the per-step fidelity threshold is only about 99 per cent. Here we demonstrate a universal set of logic gates in a superconducting multi-qubit processor, achieving an average single-qubit gate fidelity of 99.92 per cent and a two-qubit gate fidelity of up to 99.4 per cent. This places Josephson quantum computing at the fault-tolerance threshold for surface code error correction. Our quantum processor is a first step towards the surface code, using five qubits arranged in a linear array with nearest-neighbour coupling. As a further demonstration, we construct a five-qubit Greenberger-Horne-Zeilinger state using the complete circuit and full set of gates. The results demonstrate that Josephson quantum computing is a high-fidelity technology, with a clear path to scaling up to large-scale, fault-tolerant quantum circuits. PMID:24759412

  5. Pressure Pain Thresholds Increase after Preconditioning 1 Hz Repetitive Transcranial Magnetic Stimulation with Transcranial Direct Current Stimulation

    PubMed Central

    Moloney, Tonya M.; Witney, Alice G.

    2014-01-01

    Background The primary motor cortex (M1) is an effective target of non-invasive cortical stimulation (NICS) for pain threshold modulation. It has been suggested that the initial level of cortical excitability of M1 plays a key role in the plastic effects of NICS. Objective Here we investigate whether transcranial direct current stimulation (tDCS) primed 1 Hz repetitive transcranial magnetic stimulation (rTMS) modulates experimental pressure pain thresholds and if this is related to observed alterations in cortical excitability. Method 15 healthy, male participants received 10 min 1 mA anodal, cathodal and sham tDCS to the left M1 before 15 min 1 Hz rTMS in separate sessions over a period of 3 weeks. Motor cortical excitability was recorded at baseline, post-tDCS priming and post-rTMS through recording motor evoked potentials (MEPs) from right FDI muscle. Pressure pain thresholds were determined by quantitative sensory testing (QST) through a computerized algometer, on the palmar thenar of the right hand pre- and post-stimulation. Results Cathodal tDCS-primed 1 Hz-rTMS was found to reverse the expected suppressive effect of 1 Hz rTMS on cortical excitability; leading to an overall increase in activity (p<0.001) with a parallel increase in pressure pain thresholds (p<0.01). In contrast, anodal tDCS-primed 1 Hz-rTMS resulted in a corresponding decrease in cortical excitability (p<0.05), with no significant effect on pressure pain. Conclusion This study demonstrates that priming the M1 before stimulation of 1 Hz-rTMS modulates experimental pressure pain thresholds in a safe and controlled manner, producing a form of analgesia. PMID:24658333

  6. Threshold temperatures mediate the impact of reduced snow cover on overwintering freeze-tolerant caterpillars

    NASA Astrophysics Data System (ADS)

    Marshall, Katie E.; Sinclair, Brent J.

    2012-01-01

    Decreases in snow cover due to climate change could alter the energetics and physiology of ectothermic animals that overwinter beneath snow, yet how snow cover interacts with physiological thresholds is unknown. We applied numerical simulation of overwintering metabolic rates coupled with field validation to determine the importance of snow cover and freezing to the overwintering lipid consumption of the freeze-tolerant Arctiid caterpillar Pyrrharctia isabella. Caterpillars that overwintered above the snow experienced mean temperatures 1.3°C lower than those below snow and consumed 18.36 mg less lipid of a total 68.97-mg reserve. Simulations showed that linear temperature effects on metabolic rate accounted for only 30% of the difference in lipid consumption. When metabolic suppression by freezing was included, 93% of the difference between animals that overwintered above and below snow was explained. Our results were robust to differences in temperature sensitivity of metabolic rate, changes in freezing point, and the magnitude of metabolic suppression by freezing. The majority of the energy savings was caused by the non-continuous reduction in metabolic rate due to freezing, the first example of the importance of temperature thresholds in the lipid use of overwintering insects.

  7. Comparison of the thoracic flexion relaxation ratio and pressure pain threshold after overhead assembly work and below knee assembly work

    PubMed Central

    Yoo, Won-gyu

    2016-01-01

    [Purpose] The purpose of this study was to compare the thoracic flexion relaxation ratio following overhead work and below-knee work. [Subjects and Methods] Ten men (20–30 years) were recruited to this study. The thoracic flexion relaxation ratio and pressure pain threshold was measured after both overhead work and below-knee work. [Results] The pressure-pain thresholds of the thoracic erector spinae muscle decreased significantly from initial, to overhead, to below-knee work. Similarly, the thoracic flexion relaxation ratio decreased significantly from initial, to overhead, to below-knee work. [Conclusion] Below-knee work results in greater thoracic pain than overhead work. Future studies should investigate below-knee work in detail. This study confirmed the thoracic relaxation phenomenon in the mid-position of the thoracic erector spinae. PMID:26957744

  8. The effects of total and REM sleep deprivation on laser-evoked potential threshold and pain perception.

    PubMed

    Azevedo, Eduardo; Manzano, Gilberto M; Silva, Andressa; Martins, Raquel; Andersen, Monica L; Tufik, Sergio

    2011-09-01

    We investigated the effects of total and rapid eye movement (REM) sleep deprivation on the thermal nociceptive threshold and pain perception using the objective laser-evoked potential (LEP) and the subjective visual analogue scale (VAS). Twenty-eight male adult volunteers were assigned into Control (CTRL), Total (T-SD), and REM (REM-SD) Sleep Deprivation groups. The T-SD and REM-SD volunteers were totally or selectively deprived of sleep for 2 and 4 consecutive nights, respectively. Pain parameters were measured daily during the experimental period. Volunteers were stimulated on the back of the hand by blocks of 50 diode laser pulses. Intensities increased between successive blocks, ranging from nonnoxious to noxious levels, and the LEP threshold was identified based on the evoked-response onset. Both the LEP threshold and VAS ratings were significantly increased after the second night of T-SD. No significant variations were observed in the REM-SD group, suggesting a predominant role for slow wave sleep rather than selective REM-SD in pain perception. Also, for both sleep-deprived groups, the mean values of the LEP threshold and VAS ratings showed a gradual increase that was proportional to the SD deprivation time, followed by a decrease after 1 night of sleep restoration. These findings demonstrate a hyperalgesic modification to pain perception (as reflected by the augmented VAS) and a concomitant increase in the LEP threshold following T-SD, an apparently contradictory effect that can be explained by differences in the ways that attention affects these pain measurements. PMID:21624774

  9. An incremental test to identify the pain threshold speed in patients with intermittent claudication.

    PubMed

    Manfredini, Fabio; Mangolini, Cristina; Mascoli, Francesco; Mazzoni, Gianni; Cristina, Maria; Manfredini, Roberto; Conconi, Francesco

    2002-12-01

    The purpose of this study was to develop a test for identifying the speed of onset of claudication, or pain threshold speed (PTS), in 16 patients affected by intermittent claudication. An echo-Doppler examination and the ankle-brachial index (ABI) determination were also performed. Test repeatability was evaluated in 10 patients retested within a few days. All 16 patients underwent the incremental walking test 3 times during a 6-month rehabilitation training program to verify the test's sensitivity in detecting the expected functional modifications. PTS was identified in all patients examined and the test-retest correlation coefficient (R) for PTS was 0.98. During the 6-month rehabilitation period, the ABI rose from 0.43 +/-0.16 to 0.72+/-0.15 for the worst limb and PTS also rose significantly from 3.9+/-1.4 km/h to 6.1+/-1.1 km/h. The average increments of ABI and PTS were significantly correlated. An incremental walking test for the identification of the walking speed at which claudication occurs has been developed. The PTS is a reproducible parameter that can be combined with other test results to establish the severity of the disease and to check any modifications that occur during rehabilitation. PMID:12499618

  10. Is experimentally induced pain associated with socioeconomic status? Do poor people hurt more?

    PubMed Central

    Miljković, Ana; Stipčić, Ana; Braš, Marijana; Đorđević, Veljko; Brajković, Lovorka; Hayward, Caroline; Pavić, Arsen; Kolčić, Ivana; Polašek, Ozren

    2014-01-01

    Background The association of pain and socioeconomic status is widely reported, yet much less clearly understood. The aim of this study was to investigate the association of experimentally induced pain threshold and tolerance with socioeconomic status. Material/Methods The study sample consisted of 319 adult subjects from the population of the island of Vis, Croatia, which was previously shown to have a high level of social homogeneity. A manual dolorimeter was used to measure mechanical pressure pain threshold (least stimulus intensity) and pain tolerance (maximum tolerance stimulus intensity) on both hands. Pain tolerance interval was defined as the difference between pain tolerance and threshold. Years of schooling and material status were used as socioeconomic estimates. Results Both of the socioeconomic estimates were significantly correlated with pain threshold, tolerance, and tolerance interval (P<0.001). The mixed modeling analysis, controlled for the effects of age, gender, and 4 psychological variables, indicated that education was not a significant predictor in any of the 3 models. However, lower material status was significantly associated with lower pain tolerance (P=0.038) and narrower pain tolerance interval (P=0.032), but not with pain threshold (P=0.506). The overall percentages of explained variance were lower in the tolerance interval model (20.2%) than in pain tolerance (23.1%) and threshold (33.1%), suggesting the increasing share of other confounding variables in pain tolerance and even more so in tolerance interval model. Conclusions These results suggest a significant association between experimentally induced pain tolerance and tolerance interval with material status, suggesting that poor people indeed do hurt more. PMID:25029965

  11. Case report: efficacy and tolerability of ketamine in opioid-refractory cancer pain.

    PubMed

    Amin, Priya; Roeland, Eric; Atayee, Rabia

    2014-09-01

    A 36-year-old female with metastatic breast cancer involving bones, liver, lung, and pleura/chest wall with worsening back pain received weight-based intravenous (IV) ketamine and was transitioned to oral ketamine for cancer-related neuropathic pain. She had responded poorly to outpatient pain regimen of oxycodone sustained and immediate release, hydromorphone, gabapentin, and duloxetine (approximate 480 mg total oral morphine equivalents [OME]), reporting an initial pain score of 10/10. She was started on hydromorphone parenteral patient-controlled analgesia (PCA) bolus dose in addition to her outpatient regimen. Despite escalating doses of opioids and the addition of a lidocaine 5% patch, the patient's pain remained uncontrolled 6 days after admission. On hospital day 7, utilizing a hospital weight-based ketamine protocol, the patient was started on subanesthetic doses of ketamine at 0.2 mg/kg/h (288 mg/24 h) and titrated over 2 days to 0.4 mg/kg/h (576 mg/24 h). Then, a 3-day rotation from intravenous to oral ketamine was initiated, and the patient was discharged on ketamine oral solution, 75 mg every 8 hours. When the patient's dose was increased to 0.4 mg/kg/h, adequate pain relief was charted by the nurse within 120 minutes, "patient pain free and resting comfortably." Her pain continued to be well managed, with an average pain score of 5/10 with the ketamine continuous infusion and sustained with conversion to oral ketamine without any report of side effects. This was a 37% reduction in pain scores. With the patient's stabilized dose of ketamine, opioid requirements decreased by 61.4% (1017.5 mg reduction in total OME). The use of weight-based dosing of IV continuous infusion and transition to oral ketamine was effective and tolerable in the management of opioid-refractory, neuropathic cancer pain. It is hoped that this case report promotes a discussion regarding ketamine dosing in refractory neuropathic cancer pain. PMID:25102039

  12. Associations between Pressure-Pain Threshold, Symptoms, and Radiographic Knee and Hip Osteoarthritis: The Johnston County Osteoarthritis Project

    PubMed Central

    Goode, Adam P.; Shi, Xiaoyan A.; Gracely, Richard H.; Renner, Jordan B.; Jordan, Joanne M.

    2014-01-01

    Objective To determine the association between generalized evoked pressure pain sensitivity with distal pressure-pain threshold (PPT) and the presence, severity, or number of involved knee/hip joints with radiographic osteoarthritis (rOA) or related symptoms. Methods Data for these cross-sectional analyses come from the second follow-up (2008–11) of the Johnston County Osteoarthritis Project (n=1,602). Pressure-pain threshold measurements were averaged over two trials from both the left and right trapezius. Outcomes of radiographic knee and hip OA were both defined by a Kellgren-Lawrence score of 2–4 and site-specific symptoms were ascertained at clinical interview. Associations were determine with multiple logistic regression models, and two-way interactions were tested at p<0.05. Results The sample was 67.2% female and 31.0% African American. Participants’ mean age was 67.9 (SD 9.0); mean body mass index was 31.5 (SD 7.1); mean Center for Epidemiologic Studies Depression Scale score was 6.5 (SD 7.4); and mean total PPT was 3.6kg (SD 0.7). Significant associations were found between PPT and self-reported knee/hip symptoms. No significant associations were found between PPT and presence, severity, or number of joints with knee and hip rOA without accompanying symptoms. No significant interactions were found with demographic or clinical characteristics. Conclusion Pressure-pain threshold was significantly associated with self-reported single and multi-joint symptoms. In contrast, after adjustment, PPT measured at the trapezius was not associated with asymptomatic knee or hip rOA. As such, PPT may prove to be a useful indicator of rOA pain processing and of why individuals respond favorably and others do not to treatments targeting rOA. PMID:24643946

  13. Interactions of the potent D-amino acid oxidase inhibitor CBIO with morphine in pain and tolerance to analgesia.

    PubMed

    Gong, Nian; Wang, Yan-Chao; Wang, Hui-Li; Ma, Ai-Niu; Hashimoto, Kenji; Wang, Yong-Xiang

    2012-09-01

    A series of experiments using technologies of gene mutation and silencing as well as chemical biology have demonstrated that spinal D-amino acid oxidase (DAAO) contributes to the development of central sensitization-mediated chronic pain and might be a potential molecular target for the treatment of chronic pain. DAAO inhibitors are now under clinical investigations for the management of chronic neuropathic pain. This study examined the interactions between morphine and the DAAO inhibitor CBIO (5-chloro-benzo[d]isoxazol-3-ol) in pain and analgesia tolerance mainly in the formalin test. Given subcutaneously CBIO acutely interacted with morphine in analgesia in an additive manner both in the acute nociception settings (the formalin acute phase nociception, hot-plate test and tail immersion test) and in formalin-induced tonic pain. Bi-daily exposure of CBIO given subcutaneously for 7 days did not produce self-tolerance to analgesia or cross-tolerance to morphine whereas 7-day subcutaneous morphine induced self-tolerance to analgesia but not cross-tolerance to CBIO. More importantly, subcutaneous co-administrations or even single dose of CBIO completely prevented or reversed morphine tolerance to analgesia (exhibited by a single dose or a dose-response curve of morphine) in both formalin-induced acute phase nociception and tonic phase pain. These results, for the first time, identified DAAO as an efficacious molecule mediating morphine tolerance, in addition to clarifying the complex interactions between morphine and DAAO inhibitors probed by CBIO, and provided a pharmacological basis for DAAO inhibitors in combination with morphine to clinically manage pain. PMID:22587944

  14. Long-term efficacy, safety and tolerability of Remoxy for the management of chronic pain.

    PubMed

    Pergolizzi, Joseph V; Zampogna, Gianpietro; Taylor, Robert; Raffa, Robert B

    2015-03-01

    Historically, chronic pain generally went under-treated for a variety of objective and subjective reasons, including difficulty to objectively diagnose and manage over a long period of time, potential serious adverse effects of commonly available medications, and patient, healthcare and societal concerns over opioid medications. More recently, in an effort to redress the under-treatment of pain, the number of prescriptions of opioid analgesics has risen dramatically. However, paralleling the increased legitimate use has been a concomitant increase in opioid abuse, misuse and diversion. Pharmaceutical companies have responded by developing a variety of opioid formulations designed to deter abuse by making the products more difficult to tamper with. One such product is Remoxy(®), an extended-release formulation of the strong opioid oxycodone. We review the efficacy, safety and tolerability of this formulation based on the available published literature. PMID:25683255

  15. The combined effects of transcutaneous electrical nerve stimulation (TENS) and stretching on muscle hardness and pressure pain threshold.

    PubMed

    Karasuno, Hiroshi; Ogihara, Hisayoshi; Morishita, Katsuyuki; Yokoi, Yuka; Fujiwara, Takayuki; Ogoma, Yoshiro; Abe, Koji

    2016-04-01

    [Purpose] This study aimed to clarify the immediate effects of a combined transcutaneous electrical nerve stimulation and stretching protocol. [Subjects] Fifteen healthy young males volunteered to participate in this study. The inclusion criterion was a straight leg raising range of motion of less than 70 degrees. [Methods] Subjects performed two protocols: 1) stretching (S group) of the medial hamstrings, and 2) tanscutaneous electrical nerve stimulation (100 Hz) with stretching (TS group). The TS group included a 20-minute electrical stimulation period followed by 10 minutes of stretching. The S group performed 10 minutes of stretching. Muscle hardness, pressure pain threshold, and straight leg raising range of motion were analyzed to evaluate the effects. The data were collected before transcutaneous electrical nerve stimulation (T1), before stretching (T2), immediately after stretching (T3), and 10 minutes after stretching (T4). [Results] Combined transcutaneous electrical nerve stimulation and stretching had significantly beneficial effects on muscle hardness, pressure pain threshold, and straight leg raising range of motion at T2, T3, and T4 compared with T1. [Conclusion] These results support the belief that transcutaneous electrical nerve stimulation combined with stretching is effective in reducing pain and decreasing muscle hardness, thus increasing range of motion. PMID:27190439

  16. The combined effects of transcutaneous electrical nerve stimulation (TENS) and stretching on muscle hardness and pressure pain threshold

    PubMed Central

    Karasuno, Hiroshi; Ogihara, Hisayoshi; Morishita, Katsuyuki; Yokoi, Yuka; Fujiwara, Takayuki; Ogoma, Yoshiro; Abe, Koji

    2016-01-01

    [Purpose] This study aimed to clarify the immediate effects of a combined transcutaneous electrical nerve stimulation and stretching protocol. [Subjects] Fifteen healthy young males volunteered to participate in this study. The inclusion criterion was a straight leg raising range of motion of less than 70 degrees. [Methods] Subjects performed two protocols: 1) stretching (S group) of the medial hamstrings, and 2) tanscutaneous electrical nerve stimulation (100 Hz) with stretching (TS group). The TS group included a 20-minute electrical stimulation period followed by 10 minutes of stretching. The S group performed 10 minutes of stretching. Muscle hardness, pressure pain threshold, and straight leg raising range of motion were analyzed to evaluate the effects. The data were collected before transcutaneous electrical nerve stimulation (T1), before stretching (T2), immediately after stretching (T3), and 10 minutes after stretching (T4). [Results] Combined transcutaneous electrical nerve stimulation and stretching had significantly beneficial effects on muscle hardness, pressure pain threshold, and straight leg raising range of motion at T2, T3, and T4 compared with T1. [Conclusion] These results support the belief that transcutaneous electrical nerve stimulation combined with stretching is effective in reducing pain and decreasing muscle hardness, thus increasing range of motion. PMID:27190439

  17. Catastrophizing as a mediator of sex differences in pain: differential effects for daily pain versus laboratory-induced pain.

    PubMed

    Edwards, Robert R; Haythornthwaite, Jennifer A; Sullivan, Michael J; Fillingim, Roger B

    2004-10-01

    Sex differences in the experience of pain have been widely reported, with females generally reporting more frequent clinical pain and demonstrating greater pain sensitivity. However, the mechanisms underpinning such differences, while subject to intense speculation, are not well-characterized. Catastrophizing is a cognitive and affective process that relates strongly to enhanced reports of pain and that varies as a function of sex. It is thus a prime candidate to explain sex differences; indeed, several prior studies offer evidence that controlling for catastrophizing eliminates the gap between men and women in reported pain. We recruited 198 healthy young adults (115 female) who took part in laboratory studies of pain responses, including thermal pain, cold pain, and ischemic pain, and who also completed questionnaires assessing catastrophizing, mood, and day-to-day painful symptoms (e.g. headache, backache). Women reported greater levels of catastrophizing, more recent painful symptoms, and demonstrated lower pain thresholds and tolerances for noxious heat and cold relative to men. Mediational analyses suggested that after controlling for negative mood, catastrophizing mediated the sex difference in recent daily pain but did not mediate the much larger sex differences in pain threshold and tolerance. These findings highlight the role of catastrophizing in shaping pain responses, as well as illuminating potentially important differences between experimental pain assessment and the clinical experience of pain. PMID:15363877

  18. Acupuncture at both ST25 and ST37 improves the pain threshold of chronic visceral hypersensitivity rats.

    PubMed

    Liu, Hui-Rong; Wang, Xiao-Mei; Zhou, En-Hua; Shi, Yin; Li, Na; Yuan, Ling-Song; Wu, Huan-Gan

    2009-11-01

    Previous studies demonstrated the efficacy of electro-acupuncture (EA) in relieving chronic visceral hypersensitivity (CVH) in IBS rats. However, ST25 which is a key acupoint for patients with IBS has not been reported in these experiments. Eight CVH rats were treated by EA at both ST25 and ST37 for 20 min, once daily for seven consecutive days, model rats (n = 8) and normal rats (n = 8) as controls. After the first EA treatment, the abdominal withdrawal reflex scores were investigated to evaluate the pain threshold. After seven EA treatments, the concentrations of 5-hydroxytryptamine (5-HT), 5-HT3 receptor (5-HT3R) and 5-HT4 receptor (5-HT4R) in colon tissue were assayed quantitatively by enzyme-linked immunosorbent assay. The results showed that EA improved the pain threshold of CVH rats, reduced the 5-HT concentration and increased the 5-HT4R concentration, but had no effect on the 5-HT3R concentration. Further studies are needed to optimize the choice of two-matching points for EA in the treatment of CVH rats. PMID:19387829

  19. Ultra-low dose ketamine and memantine treatment for pain in an opioid-tolerant oncology patient.

    PubMed

    Grande, Lucinda A; O'Donnell, Brendan R; Fitzgibbon, Dermot R; Terman, Gregory W

    2008-10-01

    Patients taking high-dose opioids chronically for tumor-related or neuropathic pain may develop pain that is refractory to opioids. One option for control of such pain is the use of the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine. We describe a case of opioid-refractory pain that responded to a low-dose IV infusion of ketamine in the inpatient setting. The patient was then successfully transitioned to oral memantine for long-term outpatient management, in a novel use of this oral NMDA receptor antagonist. We present recent findings from basic research on pain mechanisms to explain why opioid tolerance, as in this patient, may contribute to the analgesic benefit of NMDA receptor antagonists. PMID:18806055

  20. There's More Than Catastrophizing in Chronic Pain: Low Frustration Tolerance and Self-Downing Also Predict Mental Health in Chronic Pain Patients.

    PubMed

    Suso-Ribera, Carlos; Jornet-Gibert, Montsant; Ribera Canudas, Maria Victoria; McCracken, Lance M; Maydeu-Olivares, Alberto; Gallardo-Pujol, David

    2016-06-01

    Among the potential range of irrational beliefs that could be used as predictors of physical and mental health, catastrophizing is the process that has received most attention in chronic pain research. Other irrational processes such as demandingness, low frustration tolerance, and self-downing have rarely been studied. The goal of this study was to explore whether this wider range of beliefs is associated with health in chronic pain patients beyond catastrophizing. A total of 492 chronic pain patients completed a measure of irrational beliefs, a measure of physical and mental health, and a numerical rating scale designed to assess pain intensity and interference. Irrational processes were more strongly associated with mental than with physical health. Low frustration tolerance and self-downing were found to be significantly related to mental health even after controlling for the effect of catastrophizing. Processes other than catastrophizing appear to have potentially important relationships with the mental health of people with chronic pain. These results may offer new intervention targets for practitioners. PMID:26995738

  1. Correlation between the levels of non-specific physical symptoms and pressure pain thresholds measured by algometry in patients with temporomandibular disorders.

    PubMed

    Ramalho, D; Macedo, L; Goffredo Filho, G; Goes, C; Tesch, R

    2015-02-01

    Recent studies showed that patients with chronic TMD pain also feature increased sensitivity in other craniofacial regions, and even in remote peripheral areas, suggesting that nociceptive processing is centrally facilitated in this patient population. The aim of this study was to investigate the existence of a negative correlation between the levels of non-specific physical symptoms and pressure pain thresholds measured by algometry at sites distant from the chief complaint of oro-facial pain in patients with TMD. A total of 20 female patients were evaluated comprising 11 patients diagnosed with myofascial pain (Group I of RDC/TMD) and 9 patients with arthralgia (Group III of RDC/TMD), with both reporting chronic TMD pain for at least 3months. Patients were tested by the pressure algometry technique, and, in the same visit, clinical diagnosis and levels of non-specific physical symptoms, including pain-related issues or not, were obtained. The raw scores were then standardised into a T-score. The possible correlation between the dependent variable levels of non-specific physical symptoms and pressure pain thresholds measured by algometry at sites distant from the chief complaint of oro-facial pain was assessed with Spearman's correlation coefficient. Results were considered statistically significant, which stood a lower than 5% probability of occurring by chance (P<005). A statistically significant (P=002) negative correlation (-051) was found to exist between the levels of non-specific physical symptoms, only if including issues involving pain-related symptoms, and experimental pressure pain thresholds in patients with painful TMD. PMID:25293389

  2. Habitat selection and ranges of tolerance: how do species differ beyond critical thresholds?

    PubMed Central

    Cunningham, Mary Ann; Johnson, Douglas H

    2012-01-01

    Sensitivity to habitat fragmentation often has been examined in terms of thresholds in landscape composition at which a species is likely to occur. Observed thresholds often have been low or absent, however, leaving much unexplained about habitat selection beyond initial thresholds of occurrence, even for species with strong habitat preferences. We examined responses to varying amounts of tree cover, a widely influential measure of habitat loss, for 40 woodland bird species in a mixed woodland/grassland landscape in eastern North Dakota, USA. We used LOESS smoothing to describe incidence for each species at three scales: within 200, 400, and 1200 m around sample locations. For the 200-m scale, we also calculated the most-preferred range of tree cover (within which at least half of observations were predicted to occur) for each species. Only 10 of 40 species had occurrence thresholds greater than about 10% tree cover. After initial occurrence, species showed three general patterns: some increased monotonically with tree cover; some increased up to an asymptote; some peaked at intermediate amounts of tree cover and then declined. These patterns approximate selection for interior woodlands and for edge-rich environments, but incidence plots provide greater detail in landscape-scale selection than do those categories. For most species, patterns persisted at larger scales, but for some, larger scales had distinctly different patterns than local scales. Preferred ranges of tree cover varied from <20% tree cover (common grackle, Quiscalus quiscula) to >60% (veery, Catharus fuscescens). We conclude that incidence patterns provide more information on habitat selection than do threshold measures for most species: in particular, they differentiate species preferring concentrated woodlands from those preferring mixed landscapes, and they show contrasting degrees of selectiveness. [Correction added on 16 October 2012, after first online publication: the Abstract section has been reworded]. PMID:23170216

  3. Comparison of Pressure Pain Threshold, Grip Strength, Dexterity and Touch Pressure of Dominant and Non-Dominant Hands within and Between Right- and Left-Handed Subjects

    PubMed Central

    Tulum, Zeliha; Pınar, Lamia; Başkurt, Ferdi

    2004-01-01

    This study was done to evaluate differences in pressure pain threshold, grip strength, manual dexterity and touch pressure threshold in the dominant and non-dominant hands of right- and left-handed subjects, and to compare findings within and between these groups. Thirty-nine right-handed and twenty-one left-handed subjects participated in the study. Pressure pain threshold was assessed using a dolorimeter, grip strength was assessed with a hand-grip dynamometer, manual dexterity was evaluated using the VALPAR Component Work Sample-4 system, and touch pressure threshold was determined using Semmes Weinstein monofilaments. Results for the dominant and non-dominant hands were compared within and between the groups. In the right-handed subjects, the dominant hand was significantly faster with the VALPAR Component Work Sample-4, showed significantly greater grip strength, and had a significantly higher pressure pain threshold than the non-dominant hand. The corresponding results for the two hands were similar in the left-handed subjects. The study revealed asymmetrical manual performance in grip strength, manual dexterity and pressure pain threshold in right-handed subjects, but no such asymme-tries in left-handed subjects. PMID:15608401

  4. Clinical Comparative Study: Efficacy and Tolerability of Tolperisone and Thiocolchicoside in Acute Low Back Pain and Spinal Muscle Spasticity

    PubMed Central

    Rao, Rajeev; Panghate, Atul; Chandanwale, Ajay; Sardar, Indrajeet; Ghosh, Mriganka; Roy, Modan; Banerjee, Bireswar; Goswami, Ankur

    2012-01-01

    Study Design We performed a multicentric, randomized, comparative clinical trial. Eligible patients were randomly assigned to receive 150 mg of Tolperisone thrice daily or 8 mg of Thiocolchicoside twice daily for 7 days. Purpose To assess the efficacy and tolerability of Tolperisone in comparison with Thiocolchicoside in the treatment of acute low back pain with spasm of spinal muscles. Overview of Literature No head on clinical trial of Tolperisone with Thiocolchicoside is available and so this study is done. Methods The assessment of muscle spasm was made by measuring the finger-to-floor distance (FFD), articular excursion in degrees on performing Lasegue's maneuver and modified Schober's test. Assessment of pain on movement and spontaneous pain (pain at rest) of the lumbar spine was made with the help of visual analogue scale score. Results The improvement in articular excursion on Lasegue's maneuver was significantly greater on day 3 (p = 0.017) and day 7 (p = 0.0001) with Tolperisone as compared to Thiocolchicoside. The reduction in FFD score was greater on day 7 (p = 0.0001) with Tolperisone. However there was no significant difference in improvement in Schober's test score on day 3 (p = 0.664) and day 7 (p = 0.192). The improvement in pain score at rest and on movement was significantly greater with Tolperisone (p = 0.0001). Conclusions Tolperisone is an effective and well tolerated option for treatment of patients with skeletal muscle spasm associated with pain. PMID:22708015

  5. Heat-related deaths in hot cities: estimates of human tolerance to high temperature thresholds.

    PubMed

    Harlan, Sharon L; Chowell, Gerardo; Yang, Shuo; Petitti, Diana B; Morales Butler, Emmanuel J; Ruddell, Benjamin L; Ruddell, Darren M

    2014-03-01

    In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax) and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages <65 and ≥ 65 during the months May-October for years 2000-2008. The most robust relationship was between ATmax on day of death and mortality from direct exposure to high environmental heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90-97 °F; 32.2-36.1 °C) were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C). Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C) with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C) and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C) and males <65 years (ATmax = 102 °F; 38.9 °C). Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide. PMID:24658410

  6. Heat-Related Deaths in Hot Cities: Estimates of Human Tolerance to High Temperature Thresholds

    PubMed Central

    Harlan, Sharon L.; Chowell, Gerardo; Yang, Shuo; Petitti, Diana B.; Morales Butler, Emmanuel J.; Ruddell, Benjamin L.; Ruddell, Darren M.

    2014-01-01

    In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax) and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages <65 and ≥65 during the months May–October for years 2000–2008. The most robust relationship was between ATmax on day of death and mortality from direct exposure to high environmental heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90–97 °F; 32.2‒36.1 °C) were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C). Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C) with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C) and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C) and males <65 years (ATmax = 102 °F; 38.9 °C). Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide. PMID:24658410

  7. Group music performance causes elevated pain thresholds and social bonding in small and large groups of singers

    PubMed Central

    Weinstein, Daniel; Launay, Jacques; Pearce, Eiluned; Dunbar, Robin I. M.; Stewart, Lauren

    2016-01-01

    Over our evolutionary history, humans have faced the problem of how to create and maintain social bonds in progressively larger groups compared to those of our primate ancestors. Evidence from historical and anthropological records suggests that group music-making might act as a mechanism by which this large-scale social bonding could occur. While previous research has shown effects of music making on social bonds in small group contexts, the question of whether this effect ‘scales up’ to larger groups is particularly important when considering the potential role of music for large-scale social bonding. The current study recruited individuals from a community choir that met in both small (n = 20 – 80) and large (a ‘megachoir’ combining individuals from the smaller subchoirs n = 232) group contexts. Participants gave self-report measures (via a survey) of social bonding and had pain threshold measurements taken (as a proxy for endorphin release) before and after 90 minutes of singing. Results showed that feelings of inclusion, connectivity, positive affect, and measures of endorphin release all increased across singing rehearsals and that the influence of group singing was comparable for pain thresholds in the large versus small group context. Levels of social closeness were found to be greater at pre- and post-levels for the small choir condition. However, the large choir condition experienced a greater change in social closeness as compared to the small condition. The finding that singing together fosters social closeness – even in large contexts where individuals are not known to each other – is consistent with evolutionary accounts that emphasize the role of music in social bonding, particularly in the context of creating larger cohesive groups than other primates are able to manage. PMID:27158219

  8. Practical Guide to the Management of Acute and Chronic Pain in the Presence of Drug Tolerance for the Healthcare Practitioner

    PubMed Central

    Vadivelu, Nalini; Singh-Gill, Harman; Kodumudi, Gopal; Kaye, Aaron Joshua; Urman, Richard D.; Kaye, Alan David

    2014-01-01

    Background Drug tolerance has been on the rise in recent years worldwide, and consequently, pain management in our population has become challenging. Methods Discussed in this review are commonly abused drugs and considerations for treating acute and chronic pain states in patients with substance disorders. Results After marijuana, alcohol, and tobacco, the most widely abused substances are oxycodone (Oxycontin), diazepam (Valium), and methylphenidate (Ritalin). Urine testing can detect metabolites of drugs used by patients and is useful for assessing drug abuse, medication diversion, and drug interactions. The comprehensive treatment of pain in a patient with addictive disorder or tolerance must address 3 issues: the patient's addiction, any associated psychiatric conditions, and the patient's pain. Eliciting a detailed history of drug abuse—illicit drugs as well as prescription drugs—and ascertaining if the patient is currently enrolled in a methadone maintenance program for the treatment of drug addiction is vital. Conclusion Medical observation, supportive care, multidisciplinary pain management, and timely interventions as necessary are the keys to safe outcomes in these patients. PMID:25249810

  9. Blockade of Toll-Like Receptor 4 Attenuates Morphine Tolerance and Facilitates the Pain Relieving Properties of Morphine

    PubMed Central

    Eidson, Lori N.

    2013-01-01

    The ventrolateral periaqueductal gray (vlPAG) is an integral locus for morphine action. Although it is clear that glia contribute to the development of morphine tolerance, to date, the investigation of their role has been limited to spinal and medullary loci. Opioids induce a neuroinflammatory response that opposes acute and long-term analgesia, thereby limiting their efficacy as therapeutic agents. Recent data suggest that the innate immune receptor Toll-like receptor 4 (TLR4), along with its coreceptor myeloid differentiation factor-2 (MD-2), mediates these effects. To date, the brain loci through which TLR4 modulates morphine tolerance have not been identified. We have previously demonstrated that chronic subcutaneous morphine results in tolerance that is accompanied by increases in vlPAG glial cell activity. Using in vivo pharmacological manipulations of vlPAG glia and TLR4 in the adult male rat, we show that intra-vlPAG administration of the general glial cell metabolic inhibitor propentofylline or the astrocyte activity inhibitor fluorocitrate attenuate tolerance to morphine. Characterization of MD-2 expression within the PAG revealed dense MD-2 expression throughout the vlPAG. Further, antagonizing vlPAG TLR4 dose dependently prevented the development of morphine tolerance, and vlPAG microinjections of TLR4 agonists dose dependently produced a “naive” tolerance to subsequent challenge doses of morphine. Finally, using a model of persistent inflammatory pain and pharmacological manipulation of TLR4 we demonstrate that systemic antagonism of TLR4 potentiated acute morphine antihyperalgesia. These results, together, indicate that vlPAG glia regulate morphine tolerance development via TLR4 signaling, and implicate TLR4 as a potential therapeutic target for the treatment of pain. PMID:24089500

  10. A Novel Magnetic Stimulator Increases Experimental Pain Tolerance in Healthy Volunteers - A Double-Blind Sham-Controlled Crossover Study

    PubMed Central

    Kortekaas, Rudie; Konopka, Karl-Heinz; Harbers, Marten; van der Hoeven, Johannes H.; van Wijhe, Marten; Aleman, André; Maurits, Natasha M.

    2013-01-01

    The ‘complex neural pulse’TM (CNP) is a neuromodulation protocol employing weak pulsed electromagnetic fields (PEMF). A pioneering paper reported an analgesic effect in healthy humans after 30 minutes of CNP-stimulation using three nested whole head coils. We aimed to devise and validate a stimulator with a novel design entailing a multitude of small coils at known anatomical positions on a head cap, to improve applicability. The main hypothesis was that CNP delivery with this novel device would also increase heat pain thresholds. Twenty healthy volunteers were enrolled in this double-blind, sham-controlled, crossover study. Thirty minutes of PEMF (CNP) or sham was applied to the head. After one week the other treatment was given. Before and after each treatment, primary and secondary outcomes were measured. Primary outcome was heat pain threshold (HPT) measured with thermal quantitative sensory testing. Other outcomes were warmth detection threshold, and aspects of cognition, emotion and motor performance. As hypothesized heat pain threshold was significantly increased after the PEMF stimulation. All other outcomes were unaltered by the PEMF but there was a trend level reduction of cognitive performance after PEMF stimulation as measured by the digit-symbol substitution task. Results from this pilot study suggest that our device is able to stimulate the brain and to modulate its function. This is in agreement with previous studies that used similar magnetic field strengths to stimulate the brain. Specifically, pain control may be achieved with PEMF and for this analgesic effect, coil design does not appear to play a dominant role. In addition, the flexible configuration with small coils on a head cap improves clinical applicability. Trial Registration Dutch Cochrane Centre NTR1093 PMID:23620795

  11. [Efficacy and tolerability of the combined therapy with mesipol and baclosan in chronic recurrent vertebrogenic pain syndrome].

    PubMed

    Karneev, A N; Solov'eva, E Iu; Fedin, A I

    2008-01-01

    An article highlights the pathogenetic aspects of treatment of reflex pain syndromes in the degenerative-dystrophic spinal lesions. Attention is focused on a rational combination of medications that may shorten the duration of analgesic and anti-inflammatory therapy to prevent the development of side-effects caused by non-steroid anti-inflammatory medications. The results of own research of analgesic efficacy and tolerability of treatment in 50 patients with chronic skeletal-muscle pain syndromes in the state of exacerbation assigned to the combination of a non-steroid anti-inflammatory medication mesipol (meloxicam) with a central myorelaxant baclosan (baclofen) are discussed. It was found the positive effect of therapy not only on pain syndrome but on comorbid symptoms as well. PMID:18833172

  12. Botulinum neurotoxin A enhances the analgesic effects on inflammatory pain and antagonizes tolerance induced by morphine in mice.

    PubMed

    Vacca, Valentina; Marinelli, Sara; Eleuteri, Cecilia; Luvisetto, Siro; Pavone, Flaminia

    2012-03-01

    Over the recent years compelling evidence has accumulated indicating that botulinum neurotoxin serotype A (BoNT/A) results in analgesic effects on neuropathic as well as inflammatory pain, both in humans and in animal models. In the present study, the pharmacological interaction of BoNT/A with morphine in fighting inflammatory pain was investigated in mice using the formalin test. Moreover, the effects of BoNT/A on the tolerance-induced by chronic administration of morphine were tested and the behavioral effects were correlated with immunofluorescence staining of glial fibrillary acidic protein, the specific marker of astrocytes, at the spinal cord level. An ineffective dose of BoNT/A (2 pg/paw) combined with an ineffective dose of morphine (1 mg/kg) exerted a significant analgesic action both during the early and the late phases of formalin test. A single intraplantar injection of BoNT/A (15 pg/paw; i.pl.), administered the day before the beginning of chronic morphine treatment (7 days of s.c. injections of 20 mg/kg), was able to counteract the occurrence of tolerance to morphine. Moreover, BoNT/A reduces the enhancement of the expression of astrocytes induced by inflammatory formalin pain. Side effects of opiates, including the development of tolerance during repeated use, may limit their therapeutic use, the possibility of using BoNT/A for lowering the effective dose of morphine and preventing the development of opioid tolerance would have relevant implications in terms of potential therapeutic perspectives. PMID:22281280

  13. Effect of Transcutaneous Electrical Nerve Stimulation on Sensation Thresholds in Patients with Painful Diabetic Neuropathy: An Observational Study

    ERIC Educational Resources Information Center

    Moharic, Metka

    2010-01-01

    Transcutaneous electrical nerve stimulation (TENS) is one of the therapies for painful neuropathy. Its analgesic mechanisms probably involve the gate control theory, the physiological block and the endogenous pain inhibitory system. The aim of the study was to determine whether TENS improves small fibre function diminished because of painful

  14. Pain

    MedlinePlus

    ... Message Strategic Plans & Reports Budget & Legislation Advisory Council Job Opportunities All About NCCIH Health Topics A-Z # A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Pain Share: Pain is the most common reason for seeking medical care. It is also a common reason ...

  15. Reduction of pain thresholds in fibromyalgia after very low-intensity magnetic stimulation: A double-blinded, randomized placebo-controlled clinical trial

    PubMed Central

    Maestú, Ceferino; Blanco, Manuel; Nevado, Angel; Romero, Julia; Rodríguez-Rubio, Patricia; Galindo, Javier; Lorite, Juan Bautista; de las Morenas, Francisco; Fernández-Argüelles, Pedro

    2013-01-01

    BACKGROUND: Exposure to electromagnetic fields has been reported to have analgesic and antinociceptive effects in several organisms. OBJECTIVE: To test the effect of very low-intensity transcranial magnetic stimulation on symptoms associated with fibromyalgia syndrome. METHODS: A double-blinded, placebo-controlled clinical trial was performed in the Sagrado Corazón Hospital, Seville, Spain. Female fibromyalgia patients (22 to 50 years of age) were randomly assigned to either a stimulation group or a sham group. The stimulation group (n=28) was stimulated using 8 Hz pulsed magnetic fields of very low intensity, while the sham group (n=26) underwent the same protocol without stimulation. Pressure pain thresholds before and after stimulation were determined using an algometer during the eight consecutive weekly sessions of the trial. In addition, blood serotonin levels were measured and patients completed questionnaires to monitor symptom evolution. RESULTS: A repeated-measures ANOVA indicated statistically significant improvement in the stimulation group compared with the control group with respect to somatosensory pain thresholds, ability to perform daily activities, perceived chronic pain and sleep quality. While improvement in pain thresholds was apparent after the first stimulation session, improvement in the other three measures occurred after the sixth week. No significant between-group differences were observed in scores of depression, fatigue, severity of headaches or serotonin levels. No adverse side effects were reported in any of the patients. CONCLUSIONS: Very low-intensity magnetic stimulation may represent a safe and effective treatment for chronic pain and other symptoms associated with fibromyalgia. PMID:24308025

  16. The initial effects of an upper extremity neural mobilization technique on muscle fatigue and pressure pain threshold of healthy adults: a randomized control trial

    PubMed Central

    Kim, Myoung-Kwon; Cha, Hyun-Gyu; Ji, Sang Gu

    2016-01-01

    [Purpose] The purpose of this study was to determine the effects of an upper extremity neural mobilization technique on delayed onset muscle soreness. [Subjects] Forty-five healthy subjects were randomly assigned to two groups: a nerve mobilization group (experimental) and a control group. [Methods] The subjects of the experimental group were administered a median nerve mobilization technique and ultrasound for the biceps brachii muscle. The subjects in the control group were only administered ultrasound for the biceps brachii muscle. Muscle fatigue and the pressure pain threshold were assessed before and after the intervention. [Results] The experimental group showed significant improvements in all variables, compared to pre-intervention. Furthermore, the control group showed significant improvements in the pressure pain threshold, compared to pre-intervention. Significant differences in the post-intervention gains in muscle fatigue and pressure pain threshold were found between the experimental group and the control group. [Conclusion] Application of the upper extremity neural mobilization technique is considered to have a positive effect on recovery from delayed onset muscle soreness. PMID:27134351

  17. The initial effects of an upper extremity neural mobilization technique on muscle fatigue and pressure pain threshold of healthy adults: a randomized control trial.

    PubMed

    Kim, Myoung-Kwon; Cha, Hyun-Gyu; Ji, Sang Gu

    2016-03-01

    [Purpose] The purpose of this study was to determine the effects of an upper extremity neural mobilization technique on delayed onset muscle soreness. [Subjects] Forty-five healthy subjects were randomly assigned to two groups: a nerve mobilization group (experimental) and a control group. [Methods] The subjects of the experimental group were administered a median nerve mobilization technique and ultrasound for the biceps brachii muscle. The subjects in the control group were only administered ultrasound for the biceps brachii muscle. Muscle fatigue and the pressure pain threshold were assessed before and after the intervention. [Results] The experimental group showed significant improvements in all variables, compared to pre-intervention. Furthermore, the control group showed significant improvements in the pressure pain threshold, compared to pre-intervention. Significant differences in the post-intervention gains in muscle fatigue and pressure pain threshold were found between the experimental group and the control group. [Conclusion] Application of the upper extremity neural mobilization technique is considered to have a positive effect on recovery from delayed onset muscle soreness. PMID:27134351

  18. Pain

    MedlinePlus

    ... especially if you drink a lot of alcohol. Opioids Opioids (OH-pee-oids), or narcotics, are the most ... and oxycodone (OKS-ih-KOH-duhn). Pain 353 Opioid side effects include: l nausea l vomiting l ...

  19. The effect of culture on pain sensitivity.

    PubMed

    Al-Harthy, M; Ohrbach, R; Michelotti, A; List, T

    2016-02-01

    Cross-cultural differences in pain sensitivity have been identified in pain-free subjects as well as in chronic pain patients. The aim was to assess the impact of culture on psychophysical measures using mechanical and electrical stimuli in patients with temporomandibular disorder (TMD) pain and pain-free matched controls in three cultures. This case-control study compared 122 female cases of chronic TMD pain (39 Saudis, 41 Swedes and 42 Italians) with equal numbers of age- and gender-matched TMD-free controls. Pressure pain threshold (PPT) and tolerance (PPTo) were measured over one hand and two masticatory muscles. Electrical perception threshold and electrical pain threshold (EPT) and tolerance (EPTo) were recorded between the thumb and index fingers. Italian females reported significantly lower PPT in the masseter muscle than other cultures (P < 0·001) and in the temporalis muscle than Saudis (P = 0·003). Swedes reported significantly higher PPT in the thenar muscle than other cultures (P = 0·017). Italians reported significantly lower PPTo in all muscles than Swedes (P ≤ 0·006) and in the masseter muscle than Saudis (P < 0·001). Italians reported significantly lower EPTo than other cultures (P = 0·01). Temporomandibular disorder cases, compared to TMD-free controls, reported lower PPT and PPTo in all the three muscles (P < 0·001). This study found cultural differences between groups in the PPT, PPTo and EPTo. Overall, Italian females reported the highest sensitivity to both mechanical and electrical stimulation, while Swedes reported the lowest sensitivity. Mechanical pain thresholds differed more across cultures than did electrical pain thresholds. Cultural factors may influence response to type of pain test. PMID:26371794

  20. Decreased pain sensitivity among people with schizophrenia: a meta-analysis of experimental pain induction studies.

    PubMed

    Stubbs, Brendon; Thompson, Trevor; Acaster, Sarah; Vancampfort, Davy; Gaughran, Fiona; Correll, Christoph U

    2015-11-01

    Patients with schizophrenia report reduced pain sensitivity in clinical studies, but experimental studies are required to establish pain sensitivity as a potential endophenotype. We conducted a systematic review of electronic databases from database inception until April 15, 2015, including experimental studies investigating pain among patients with schizophrenia spectrum disorder vs healthy controls. A random-effect meta-analysis yielding Hedges' g ±95% confidence intervals (CIs) as the effect size (ES) measure was conducted. Primary outcome was a pooled composite of pain threshold and pain tolerance; secondary outcomes included these parameters individually, plus sensory threshold, physiological pain response, and pain intensity or unpleasantness. Across 17 studies, patients with schizophrenia spectrum disorder (n = 387; age, 30.7 ± 6.9 years; females, 31.9%; illness duration, 7.0 ± 5.7 years) were compared with controls (n = 483; age, 29.5 ± 7.4 years; females, 31.0%). Patients had elevated pain threshold/pain tolerance vs controls (ES = 0.583; 95% CI, 0.212-0.954; P = 0.002; studies = 15). Results were similar in antipsychotic-free individuals (ES = 0.599; 95% CI, 0.291-0.907; P < 0.0001; studies = 8), with trend-level significance in antipsychotic-treated individuals (ES = 0.566; 95% CI, -0.007 to 1.125; P = 0.047; studies = 9). Likewise, patients with schizophrenia had increased pain tolerance (ES = 0.566; 95% CI, 0.235-0.897; P = 0.0001; studies = 6), sensory threshold (ES = 1.16; 95% CI, 0.505-1.727; P < 0.0001; studies = 5), and pain threshold (ES = 0.696; 95% CI, 0.407-0.986; P < 0.001; studies = 9), as well as reduced physiological response to noxious stimuli (ES = 0.456; 95% CI, 0.131-0.783; P = 0.006) and pain intensity/unpleasantness ratings (ES = 0.547; 95% CI, 0.146-0.949; P = 0.008). Findings were similarly significant in antipsychotic-free patients with schizophrenia (analysable parameters = 4) and antipsychotic-treated individuals (analysable parameters = 2). Finally, greater psychiatric symptoms moderated increased pain threshold, and younger patient age moderated increased pain tolerance. Decreased pain sensitivity seems to be an endophenotype of schizophrenia spectrum disorders. How this alteration links to other dimensions of schizophrenia and physical comorbidity-related help-seeking behaviour/morbidity/mortality requires further study. PMID:26207650

  1. Effect of Transcutaneous Electrical Nerve Stimulation on Sensation Thresholds in Patients with Painful Diabetic Neuropathy: An Observational Study

    ERIC Educational Resources Information Center

    Moharic, Metka

    2010-01-01

    Transcutaneous electrical nerve stimulation (TENS) is one of the therapies for painful neuropathy. Its analgesic mechanisms probably involve the gate control theory, the physiological block and the endogenous pain inhibitory system. The aim of the study was to determine whether TENS improves small fibre function diminished because of painful…

  2. Pain.

    PubMed

    Lefaucheur, Jean-Pascal

    2013-01-01

    Invasive stimulation of the motor (precentral) cortex using surgically implanted epidural electrodes is indicated for the treatment of neuropathic pain that is refractory to medical treatment. Controlled trials have demonstrated the efficacy of epidural motor cortex stimulation (MCS), but MCS outcome remains variable and validated criteria for selecting good candidates for implantation are lacking. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive approach that could be used as a preoperative tool to predict MCS outcome and also could serve as a therapeutic procedure in itself to treat pain disorders. This requires repeated rTMS sessions and a maintenance protocol. Other studies have also demonstrated the efficacy of transcranial direct current stimulation (tDCS) in relieving chronic pain syndromes. The most studied target is the precentral cortex, but other targets, such as the prefrontal and parietal cortices, could be of interest. The analgesic effects of cortical stimulation relate to the activation of various circuits modulating neural activities in remote structures, such as the thalamus, limbic cortex, insula, or descending inhibitory controls. In addition to the treatment of refractory neuropathic pain by epidural MCS, new developments of this type of strategy are ongoing, for other types of pain syndrome and stimulation techniques. PMID:24112914

  3. Blocking mammalian target of rapamycin alleviates bone cancer pain and morphine tolerance via µ-opioid receptor.

    PubMed

    Jiang, Zongming; Wu, Shaoyong; Wu, Xiujuan; Zhong, Junfeng; Lv, Anqing; Jiao, Jing; Chen, Zhonghua

    2016-04-15

    The current study was to examine the underlying mechanisms responsible for the role of mammalian target of rapamycin (mTOR) in regulating bone cancer-evoked pain and the tolerance of systemic morphine. Breast sarcocarcinoma Walker 256 cells were implanted into the tibia bone cavity of rats and this evoked significant mechanical and thermal hyperalgesia. Our results showed that the protein expression of p-mTOR, mTOR-mediated phosphorylation of 4E-binding protein 4 (4E-BP1), p70 ribosomal S6 protein kinase 1 (S6K1) as well as phosphatidylinositide 3-kinase (p-PI3K) pathways were amplified in the superficial dorsal horn of the spinal cord of bone cancer rats compared with control rats. Blocking spinal mTOR by using rapamycin significantly attenuated activities of PI3K signaling pathways as well as mechanical and thermal hyperalgesia. Additionally, rapamycin enhanced attenuations of protein kinase Cɛ (PKCɛ)/protein kinase A (PKA) induced by morphine and further extended analgesia of morphine via µ-opioid receptor (MOR). Our data for the first time revealed specific signaling pathways leading to bone cancer pain, including the activation of mTOR and PI3K and downstream PKCɛ/PKA, and resultant sensitization of MOR. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of bone cancer pain often observed in clinics. PMID:26566757

  4. Effect of gene polymorphism of COMT and OPRM1 on the preoperative pain sensitivity in patients with cancer

    PubMed Central

    Yao, Peng; Ding, Yuan-Yuan; Wang, Zhi-Bin; Ma, Jia-Ming; Hong, Tao; Pan, Shi-Nong

    2015-01-01

    Objectives: To evaluate the effect of COMT and OPRM1 gene polymorphisms on the preoperative pain sensitivity in tumor patients. Methods: 300 cases of cancer patients undergoing elective surgery were included, and the Val158 Met loci of COMT gene and OPRM1 loci of A118 G gene were genotyped by PCR-RFLP. Pain threshold and pain tolerance threshold were measured using electrical stimulation to investigate the preoperative pain sensitivity in patients with different genotypes. Results: For the COMT gene, the pain threshold and pain tolerance threshold of patients with M allele both decreased (both P < 0.001); for PPRM1 gene, pain threshold and pain tolerance threshold of patients with G allele decreased (both P < 0.001). We also found that there was an interaction between the two genes. Conclusion: Gene polymorphisms of COMT and OPRM1 were correlated with the preoperative pain sensitivity of cancer patients. The patients with M allele of COMT and G allele of OPRM1 had higher preoperative pain sensitivity. PMID:26309696

  5. Structural Health Monitoring: Leveraging Pain in the Human Body

    NASA Astrophysics Data System (ADS)

    Nayak, Subhadarshi

    2012-07-01

    Tissue damage, or the perception thereof, is managed through pain experience. The neurobiological process of pain triggers most effective defense mechanisms for our safety. Structural health monitoring (SHM) is also a very similar function, albeit in engineering systems. SHM technology can leverage many aspects of pain mechanisms to progress in several critical areas. Discrimination between features from the undamaged and damaged structures can follow the threshold gate mechanism of the pain perception. Furthermore, the sensing mechanisms can be adaptive to changes by adjusting the threshold as does the pain perception. A distributed sensor network, often advanced by SHM, can be made fault-tolerant and robust by following the perception way of self-organization and redundancy. Data handling in real life is a huge challenge for large-scale SHM. As sensory data of pain is first cleaned, the threshold is then processed through experiential information gathering and use.

  6. Newer generation fentanyl transmucosal products for breakthrough pain in opioid-tolerant cancer patients.

    PubMed

    Elsner, Frank; Zeppetella, Giovambattista; Porta-Sales, Josep; Tagarro, Ignacio

    2011-01-01

    Oral normal-release morphine has long been considered the gold-standard treatment for cancer breakthrough pain. However, its relatively long time to analgesic onset, delay in maximal analgesic effect and prolonged duration of action make it unsuitable for the management of breakthrough pain episodes. These limitations led to the development of an oral transmucosal formulation of the fast-acting opioid fentanyl (oral transmucosal fentanyl citrate [OTFC] lozenge on a plastic handle; Actiq), which has been shown to produce more rapid and effective pain relief than oral morphine. However, the formulation itself has some limitations. Consequently, investigators have continued to develop other, newer generation, transmucosal formulations of fentanyl to further improve the management of breakthrough pain. Recently, five such compounds (Effentora/Fentora, Abstral, Instanyl, Breakyl/OnsolisTM and PecFent) have been concurrently approved in Europe and/or the US, and have documented efficacy in quickly relieving breakthrough pain episodes. All of the available pivotal efficacy trials of these agents are randomized, double-blind comparisons with placebo. There are no head-to-head trials comparing any of the newer transmucosal formulations with each other. Only one non-pivotal study of intranasal fentanyl spray used a transmucosal preparation as an active comparator. However, that comparator was OTFC, not one of the newer transmucosal products. Close examination of the existing trials assessing these newer transmucosal preparations reveals significant variation in many study parameters, such as patient selection criteria, severity of breakthrough pain episodes, proportions of patients with a neuropathic pain component, titration protocols, choice of the primary endpoints, protocols for repeat dosing and rescue medication, the separation of treated episodes and the extent of the placebo response, all of which may have affected efficacy results. It is therefore difficult to evaluate the relative efficacies of these treatments on the basis of the available trials. Furthermore, given the differences in design between studies, the value of any potential meta-analyses including these trials would likely be limited. Blinded head-to-head comparisons of new transmucosal fentanyl preparations would be the only way to conclusively determine comparative effectiveness, but given the impracticalities of conducting such studies, these are unlikely. PMID:21819159

  7. Effects of naltrexone on electrocutaneous pain in patients with hypertension compared to normotensive individuals.

    PubMed

    Ring, Christopher; France, Christopher R; al'Absi, Mustafa; Edwards, Louisa; McIntyre, David; Carroll, Douglas; Martin, Una

    2008-02-01

    An opioid mechanism may help explain hypertensive hypoalgesia. A double-blind placebo-controlled design compared the effects of opioid blockade (naltrexone) and placebo on electrocutaneous pain threshold, pain tolerance, and retrospective McGill Pain Questionnaire ratings in 35 unmedicated patients with essential hypertension and 28 normotensive individuals. The hypertensives experienced less pain than normotensives during the assessment of their pain tolerance; however, this manifestation of hypertensive hypoalgesia was not moderated by naltrexone. These findings fail to support the hypothesis that essential hypertension is characterised by relative opioid insensitivity. PMID:18031920

  8. A meta-analysis of efficacy and tolerability of buprenorphine for the relief of cancer pain.

    PubMed

    Naing, Cho; Yeoh, Peng Nam; Aung, Kyan

    2014-01-01

    This study aimed to synthesize available evidence on the analgesic efficacy of buprenorphine in treating cancer pain and related adverse effects. We searched electronic databases for randomized controlled trials, assessing the efficacy of buprenorphine, regardless of delivery system. The primary endpoints were patient-reported 'pain intensity' and 'pain relief'. Statistical heterogeneity among included studies was assessed with the I (2) test. The summary relative risk (RR) and 95% CI were derived, if two or more studies reported the similar outcome. Sixteen RCTs (n = 1329) with buprenorphine were included: 8 transdermal (TD), 5 sublingual (SL), 2 intramuscular injection (IM) and 1 subcutaneous infusion (SC) studies; with both SL and IM routes being assessed in one study. Only a few studies reported the same outcome in a similar way, creating difficulty for pooling of the outcome data. Many studies had a high risk of bias. In 2 studies (n = 241), the 'global impression change' was significantly different between TD buprenorphine and the combined placebo and morphine (RR 1.35, 95% CI 1.14-1.59; I (2): 42%); the 'number-needed-to-treat' (NNT) was 4.9 (95% CI: 3.1-10.9). In 2 studies (n = 331), 'requirement for rescue SL buprenorphine' was comparable between TD buprenorphine and placebo (RR 1.25, 95% CI 0.71-2.18; I (2) : 40%). In 2 studies (n = 141), 'incidence of nausea' was less in TD buprenorphine (RR: 0.38, 95% CI: 0.2-0.71, I (2): 0%, NNT: 9.3, 5.6-28.5). Due to the small number of participants in a small number of studies, the results of the present review provide insufficient evidence to position adequately the use of buprenorphine in treatment of cancer pain. Large multicenter RCTs that compare TD buprenorphine with standard analgesic treatment is needed to position TD buprenorphine in the therapeutic armamentarium of cancer pain treatment. PMID:24600544

  9. Parental-reported pain insensitivity in Dup15q.

    PubMed

    Luchsinger, Kadi; Lau, Heather; Hedlund, Julie L; Friedman, Daniel; Krushel, Kara; Devinsky, Orrin

    2016-02-01

    Parents of children with chromosome 15q duplication syndrome (Dup15q) have anecdotally reported high pain threshold as a feature of the disorder. The purpose of this study was to document parental-reported estimates of the frequency of high pain tolerance and the stimuli that fail to evoke a normal pain response. We sent an online survey to 840 families with children with Dup15q to explore the frequency and clinical manifestations of high pain threshold. There were 216 respondents (25.7%). A high pain threshold was reported in 87% of children at some time. There was a trend (p=0.06) for high pain threshold to be more commonly observed among children with the isodicentric (85.6%) and other genetic variants (95%) than interstitial (69.6%) duplications. There was no association between reports of high pain threshold and reports of an intellectual disability (91% of cases), autism spectrum disorder (83% of cases), or self-injurious behavior (40% of cases). Reports included many dramatic cases such as severe burns, broken bones, and electrical traumas, which were associated with little or no evidence of a painful stimulus. A high pain threshold is reported in other disorders associated with intellectual disability and autism; the underlying mechanism in Dup15q and other disorders remains undefined. PMID:26773682

  10. Neuropathic pain activates the endogenous kappa opioid system in mouse spinal cord and induces opioid receptor tolerance.

    PubMed

    Xu, Mei; Petraschka, Michael; McLaughlin, Jay P; Westenbroek, Ruth E; Caron, Marc G; Lefkowitz, Robert J; Czyzyk, Traci A; Pintar, John E; Terman, Gregory W; Chavkin, Charles

    2004-05-12

    Release of endogenous dynorphin opioids within the spinal cord after partial sciatic nerve ligation (pSNL) is known to contribute to the neuropathic pain processes. Using a phosphoselective antibody [kappa opioid receptor (KOR-P)] able to detect the serine 369 phosphorylated form of the KOR, we determined possible sites of dynorphin action within the spinal cord after pSNL. KOR-P immunoreactivity (IR) was markedly increased in the L4-L5 spinal dorsal horn of wild-type C57BL/6 mice (7-21 d) after lesion, but not in mice pretreated with the KOR antagonist nor-binaltorphimine (norBNI). In addition, knock-out mice lacking prodynorphin, KOR, or G-protein receptor kinase 3 (GRK3) did not show significant increases in KOR-P IR after pSNL. KOR-P IR was colocalized in both GABAergic neurons and GFAP-positive astrocytes in both ipsilateral and contralateral spinal dorsal horn. Consistent with sustained opioid release, KOR knock-out mice developed significantly increased tactile allodynia and thermal hyperalgesia in both the early (first week) and late (third week) interval after lesion. Similarly, mice pretreated with norBNI showed enhanced hyperalgesia and allodynia during the 3 weeks after pSNL. Because sustained activation of opioid receptors might induce tolerance, we measured the antinociceptive effect of the kappa agonist U50,488 using radiant heat applied to the ipsilateral hindpaw, and we found that agonist potency was significantly decreased 7 d after pSNL. In contrast, neither prodynorphin nor GRK3 knock-out mice showed U50,488 tolerance after pSNL. These findings suggest that pSNL induced a sustained release of endogenous prodynorphin-derived opioid peptides that activated an anti-nociceptive KOR system in mouse spinal cord. Thus, endogenous dynorphin had both pronociceptive and antinociceptive actions after nerve injury and induced GRK3-mediated opioid tolerance. PMID:15140929

  11. Neuropathic Pain Activates the Endogenous κ Opioid System in Mouse Spinal Cord and Induces Opioid Receptor Tolerance

    PubMed Central

    Xu, Mei; Petraschka, Michael; McLaughlin, Jay P.; Westenbroek, Ruth E.; Caron, Marc G.; Lefkowitz, Robert J.; Czyzyk, Traci A.; Pintar, John E.; Terman, Gregory W.; Chavkin, Charles

    2008-01-01

    Release of endogenous dynorphin opioids within the spinal cord after partial sciatic nerve ligation (pSNL) is known to contribute to the neuropathic pain processes. Using a phosphoselective antibody [κ opioid receptor (KOR-P)] able to detect the serine 369 phosphorylated form of the KOR, we determined possible sites of dynorphin action within the spinal cord after pSNL. KOR-P immunoreactivity (IR) was markedly increased in the L4 –L5 spinal dorsal horn of wild-type C57BL/6 mice (7–21 d) after lesion, but not in mice pretreated with the KOR antagonist nor-binaltorphimine (norBNI). In addition, knock-out mice lacking prodynorphin, KOR, or G-protein receptor kinase 3 (GRK3) did not show significant increases in KOR-P IR after pSNL. KOR-P IR was colocalized in both GABAergic neurons and GFAP-positive astrocytes in both ipsilateral and contralateral spinal dorsal horn. Consistent with sustained opioid release, KOR knock-out mice developed significantly increased tactile allodynia and thermal hyperalgesia in both the early (first week) and late (third week) interval after lesion. Similarly, mice pretreated with norBNI showed enhanced hyperalgesia and allodynia during the 3 weeks after pSNL. Because sustained activation of opioid receptors might induce tolerance, we measured the antinociceptive effect of the κ agonist U50,488 using radiant heat applied to the ipsilateral hindpaw, and we found that agonist potency was significantly decreased 7 d after pSNL. In contrast, neither prodynorphin nor GRK3 knock-out mice showed U50,488 tolerance after pSNL. These findings suggest that pSNL induced a sustained release of endogenous prodynorphin-derived opioid peptides that activated an anti-nociceptive KOR system in mouse spinal cord. Thus, endogenous dynorphin had both pronociceptive and antinociceptive actions after nerve injury and induced GRK3-mediated opioid tolerance. PMID:15140929

  12. An open-label, long-term study examining the safety and tolerability of pregabalin in Japanese patients with central neuropathic pain

    PubMed Central

    Onouchi, Kenji; Koga, Hiroaki; Yokoyama, Kazumasa; Yoshiyama, Tamotsu

    2014-01-01

    Purpose Studies of pregabalin for the treatment of central neuropathic pain have been limited to double-blind trials of 4–17 weeks in duration. The purpose of this study was to assess the long-term safety and tolerability of pregabalin in Japanese patients with central neuropathic pain. The efficacy of pregabalin was also assessed as a secondary measure. Patients and methods This was a 53-week, multicenter, open-label trial of pregabalin (150–600 mg/day) in Japanese patients with central neuropathic pain due to spinal cord injury, multiple sclerosis, or cerebral stroke. Results A total of 103 patients received pregabalin (post-stroke =60; spinal cord injury =38; and multiple sclerosis =5). A majority of patients (87.4%) experienced one or more treatment-related adverse events, most commonly somnolence, weight gain, dizziness, or peripheral edema. The adverse event profile was similar to that seen in other indications of pregabalin. Most treatment-related adverse events were mild (89.1%) or moderate (9.2%) in intensity. Pregabalin treatment improved total score, sensory pain, affective pain, visual analog scale (VAS), and present pain intensity scores on the Short-Form McGill Pain Questionnaire (SF-MPQ) and ten-item modified Brief Pain Inventory (mBPI-10) total score at endpoint compared with baseline. Improvements in SF-MPQ VAS and mBPI-10 total scores were evident in all patient subpopulations. Mean changes from baseline in SF-MPQ VAS and mBPI-10 scores at endpoint were −20.1 and −1.4, respectively. Conclusion These findings demonstrate that pregabalin is generally well tolerated and provides sustained efficacy over a 53-week treatment period in patients with chronic central neuropathic pain. PMID:25114584

  13. Peripherally driven low-threshold inhibitory inputs to lamina I local-circuit and projection neurones: a new circuit for gating pain responses

    PubMed Central

    Luz, Liliana L; Szucs, Peter; Safronov, Boris V

    2014-01-01

    Spinal lamina I is a key element of the pain processing system which relays primary afferent input to supraspinal areas. However, little is known about how the signal is modulated by its intrinsic network including local-circuit neurones (LCNs) and much less numerous anterolateral tract projection neurones (PNs). Here, we used whole-cell patch clamp recordings in an isolated spinal cord preparation to examine properties of identified LCNs (n=85) and PNs (n=73) in their functionally preserved local networks. Forty LCNs showed spontaneous rhythmic firing (27Hz) at zero current injection, which persisted in the presence of blockers of fast synaptic transmission. In the remaining cases, most LCNs and PNs fired tonically in response to depolarizing current injections. We identified LCNs and PNs receiving low-threshold primary afferent-driven inhibitory inputs, which in many cases were disynaptic and temporally preceded classical high-threshold excitatory inputs. This direct inhibitory link between low-threshold afferents and PNs can function as a postsynaptic gate controlling the nociceptive information flow in the spinal cord. The LCNs were found to be integrated into the superficial dorsal horn network by their receipt of monosynaptic and disynaptic inputs from other lamina I and II neurones. One-third of LCNs and two-thirds of PNs tested responded to substance P application. Thus, substance P released by a noxious afferent stimulation may excite PNs in two ways: directly, and via the activation of presynaptic LCN circuitries. In conclusion, we have described important properties of identified lamina I neurones and their roles in a new circuit for gating pain responses. PMID:24421354

  14. The role of sleep problems in central pain processing in rheumatoid arthritis

    PubMed Central

    Lee, Yvonne C.; Lu, Bing; Edwards, Robert R.; Wasan, Ajay D.; Nassikas, Nicholas J.; Clauw, Daniel J.; Solomon, Daniel H.; Karlson, Elizabeth W.

    2012-01-01

    Objective Among rheumatoid arthritis (RA) patients, pain may exist out of proportion to peripheral inflammation. This observation suggests that central nervous system pain amplification mechanisms, such as diminished conditioned pain modulation (CPM), may play a role in enhancing pain perception among some RA patients. We examined CPM, pressure pain threshold and pressure pain tolerance among RA patients compared to controls. Methods Fifty-eight female RA patients and 54 age-matched controls without chronic pain underwent quantitative sensory testing (QST) to assess CPM, pressure pain threshold and pressure pain tolerance. CPM was induced using a cold water bath, and pain threshold (when patients first felt pain) and tolerance (when pain was too much to bear) were assessed with an algometer. Associations between RA and QST measures were analyzed using linear regression. Sleep problems, mental health and inflammation were assessed as mediators of the relationship between RA and QST measures. Results Median CPM levels were 0.5 kg/cm2 (interquartile range (IQR) ?0.1, 1.6) among RA patients compared to 1.5 kg/cm2 (IQR ?0.1, 2.5) among controls (P = 0.04). Relative to controls, RA patients had lower pain threshold and tolerance at the wrists (P ? 0.05). Compared to controls, RA patients had greater problems with sleep, catastrophizing, depression and anxiety (P < 0.0001). Mediation analyses suggested that low CPM levels may be partially attributable to sleep disturbance (P = 0.04). Conclusion RA patients have impaired CPM relative to pain-free controls. Sleep problems may mediate the association between RA and attenuated CPM. PMID:23124650

  15. Agreeable Smellers and Sensitive Neurotics – Correlations among Personality Traits and Sensory Thresholds

    PubMed Central

    Croy, Ilona; Springborn, Maria; Lötsch, Jörn; Johnston, Amy N. B.; Hummel, Thomas

    2011-01-01

    Correlations between personality traits and a wide range of sensory thresholds were examined. Participants (N = 124) completed a personality inventory (NEO-FFI) and underwent assessment of olfactory, trigeminal, tactile and gustatory detection thresholds, as well as examination of trigeminal and tactile pain thresholds. Significantly enhanced odor sensitivity in socially agreeable people, significantly enhanced trigeminal sensitivity in neurotic subjects, and a tendency for enhanced pain tolerance in highly conscientious participants was revealed. It is postulated that varied sensory processing may influence an individual's perception of the environment; particularly their perception of socially relevant or potentially dangerous stimuli and thus, varied with personality. PMID:21556139

  16. Repeated Applications of Thoracic Spine Thrust Manipulation do not Lead to Tolerance in Patients Presenting with Acute Mechanical Neck Pain: A Secondary Analysis

    PubMed Central

    Fernández-De-Las-Peñas, Cesar; Cleland, Joshua A; Huijbregts, Peter; Palomeque-Del-Cerro, Luis; González-Iglesias, Javier

    2009-01-01

    It has been demonstrated that patients receiving mobilization techniques do not exhibit tolerance to repeated applications. However, this phenomenon has not been investigated for thoracic manipulation. Our aim was to determine if patients receiving thoracic thrust manipulation exhibit tolerance to repeated applications in acute mechanical neck pain. Forty-five patients were randomly assigned to two groups. The control group received electro- and thermotherapy for 5 sessions, and the experimental group received the same program and also received a thoracic thrust manipulation once a week for 3 consecutive weeks. Outcome measures included neck pain and cervical mobility. Within-session change scores for pain and mobility during treatment sessions #1, 3, and 5 were examined with a one-way repeated measured ANOVA. A 2-way ANOVA with session as within-subject variable and group as between-subject variable was used to compare change scores for each visit between groups to ascertain if there were significant between-group differences in within-session changes for the experimental versus the control group. The ANOVA showed that for either group the 3 within-session change scores were not significantly different (P > 0.1). The 2-way ANOVA revealed significant differences between groups for both pain and neck mobility in within-session change scores (all, P < 0.001). Change scores in each session were superior in the experimental group as compared to those in the control group. The results suggest that patients receiving thoracic manipulation do not exhibit tolerance to repeated applications with regard to pain and mobility measures in acute mechanical neck pain. Further studies should investigate the dose-response relationship of thoracic thrust manipulation in this population. PMID:20046622

  17. Tolerability of the capsaicin 8% patch following pretreatment with lidocaine or tramadol in patients with peripheral neuropathic pain: A multicentre, randomized, assessor-blinded study

    PubMed Central

    Jensen, TS; Hye, K; Fricov, J; Vanelderen, P; Ernault, E; Siciliano, T; Marques, S

    2014-01-01

    Background Application of the capsaicin 8% patch is associated with treatment-related discomfort. Consequently, pretreatment for 60?min with anaesthetic cream is recommended; however, this may be uncomfortable and time consuming. Methods We conducted a multicentre, randomized (1:1), assessor-blinded study in patients with peripheral neuropathic pain to assess tolerability of the capsaicin patch following topical lidocaine (4%) or oral tramadol (50?mg) pretreatment. The primary endpoint was the proportion of patients tolerating capsaicin patch application (ability to receive ?90% of a 60-min application). Numeric Pain Rating Scale (NPRS) scores were assessed before, during and after treatment. Results Overall, 122 patients were included (61 per arm). The capsaicin patch was tolerated by 121 patients. Tolerability of the capsaicin patch was similar following pretreatment with lidocaine and tramadol. Following patch application, pain levels increased up to 55?min (change from baseline of 1.3 for lidocaine and 1.4 for tramadol). After patch removal, tramadol-treated patients experienced greater pain relief up to the end of day 1; in the evening, mean changes in NPRS scores from baseline were 0 for lidocaine and ?1 for tramadol. Proportions of patients reporting increases of ?2 NPRS points or >33% from baseline at one or more time point(s) on the day of treatment were similar between arms. Adverse event incidence was comparable between arms. Conclusions Capsaicin 8% patch tolerability was similar in the two arms, with comparable results for most secondary endpoints. Tramadol given 30?min before patch application should be considered as an alternative pretreatment option in patients receiving capsaicin patch treatment. What's already known about this topic? Application of topical capsaicin, a treatment for peripheral neuropathic pain conditions associated with allodynia, can cause painful discomfort. Therefore, a 60-min application of local anaesthetic cream before capsaicin 8% patch treatment was originally recommended. What does this study add? Oral analgesic pretreatment may reduce overall capsaicin patch treatment time and potential unpleasantness associated with applying a topical agent to an allodynic area. Based on LIFT data showing similar tolerability to capsaicin patch regardless of pretreatment method, the European Medicines Agency has issued a type II variation stating: treatment area may be pretreated with a topical anaesthetic or an oral analgesic may be given prior to patch application. PMID:24664539

  18. Tolerability of NGX-4010, a capsaicin 8% patch, in conjunction with three topical anesthetic formulations for the treatment of neuropathic pain

    PubMed Central

    Webster, Lynn R; Peppin, John F; Murphy, Frederick T; Tobias, Jeffrey K; Vanhove, Geertrui F

    2012-01-01

    Background The objective of this study was to assess the safety, tolerability, and preliminary efficacy of NGX-4010, a capsaicin 8% patch, following pretreatment with three different topical anesthetics in patients with peripheral neuropathic pain. Methods This open-label, multicenter study enrolled 117 patients with post-herpetic neuralgia, HIV-associated distal sensory polyneuropathy, or painful diabetic neuropathy. Patients received pretreatment with one of three lidocaine 4%-based topical anesthetics (L.M.X.4® [Ferndale Laboratories Inc, Ferndale, MI], Topicaine® Gel [Estela Basso, Jupiter, FL], or Betacaine Enhanced Gel 4 [Tiberius Inc, Tampa, FL]) for 60 minutes followed by a single 60- or 90-minute NGX-4010 application, and were followed for 12 weeks. Tolerability and safety measures included “pain now” Numeric Pain Rating Scale (NPRS) scores, dermal assessments, medication use for treatment-related pain, adverse events (AEs), clinical laboratory parameters, physical examinations, and vital signs. The primary efficacy variable was the percentage change in mean NPRS scores for “average pain for the past 24 hours” from baseline to weeks 2 through 12. Results Treatment with NGX-4010 following pretreatment with any of the three topical anesthetics was generally safe and well tolerated. Nearly all patients completed ≥90% of the planned NGX-4010 application duration. The most common treatment-related AEs, application-site burning and application-site pain, were transient, mostly mild or moderate, and could be adequately managed by local cooling or short-acting oral opioid analgesics. Although slightly more patients used medication for treatment-related discomfort following pretreatment with Topicaine compared with L.M.X.4 or Betacaine, there were no statistical differences between the topical anesthetics. Neuropathic pain reduction from baseline to weeks 2 through 12 was approximately 30% and was similar among the topical anesthetics; the proportion of responders ranged from 45% to 50%. Conclusion Treatment with NGX-4010 following pretreatment with any of the three topical anesthetics was generally safe and well tolerated; no significant differences in the parameters measured were noted between the pretreatment groups. PMID:22328830

  19. Pain Sensitivity Subgroups in Individuals With Spine Pain: Potential Relevance to Short-Term Clinical Outcome

    PubMed Central

    Bialosky, Joel E.; Robinson, Michael E.

    2014-01-01

    Background Cluster analysis can be used to identify individuals similar in profile based on response to multiple pain sensitivity measures. There are limited investigations into how empirically derived pain sensitivity subgroups influence clinical outcomes for individuals with spine pain. Objective The purposes of this study were: (1) to investigate empirically derived subgroups based on pressure and thermal pain sensitivity in individuals with spine pain and (2) to examine subgroup influence on 2-week clinical pain intensity and disability outcomes. Design A secondary analysis of data from 2 randomized trials was conducted. Methods Baseline and 2-week outcome data from 157 participants with low back pain (n=110) and neck pain (n=47) were examined. Participants completed demographic, psychological, and clinical information and were assessed using pain sensitivity protocols, including pressure (suprathreshold pressure pain) and thermal pain sensitivity (thermal heat threshold and tolerance, suprathreshold heat pain, temporal summation). A hierarchical agglomerative cluster analysis was used to create subgroups based on pain sensitivity responses. Differences in data for baseline variables, clinical pain intensity, and disability were examined. Results Three pain sensitivity cluster groups were derived: low pain sensitivity, high thermal static sensitivity, and high pressure and thermal dynamic sensitivity. There were differences in the proportion of individuals meeting a 30% change in pain intensity, where fewer individuals within the high pressure and thermal dynamic sensitivity group (adjusted odds ratio=0.3; 95% confidence interval=0.1, 0.8) achieved successful outcomes. Limitations Only 2-week outcomes are reported. Conclusions Distinct pain sensitivity cluster groups for individuals with spine pain were identified, with the high pressure and thermal dynamic sensitivity group showing worse clinical outcome for pain intensity. Future studies should aim to confirm these findings. PMID:24764070

  20. Sex differences and hormonal modulation of deep tissue pain

    PubMed Central

    Traub, Richard J.; Ji, Yaping

    2013-01-01

    Women disproportionately suffer from many deep tissue pain conditions. Experimental studies show that women have lower pain thresholds, higher pain ratings and less tolerance to a range of painful stimuli. Most clinical and epidemiological reports suggest female gonadal hormones modulate pain for some, but not all, conditions. Similarly, animal studies support greater nociceptive sensitivity in females in many deep tissue pain models. Gonadal hormones modulate responses in primary afferents, dorsal horn neurons and supraspinal sites, but the direction of modulation is variable. This review will examine sex differences in deep tissue pain in humans and animals focusing on the role of gonadal hormones (mainly estradiol) as an underlying component of the modulation of pain sensitivity. PMID:23872333

  1. Identification of Molecular Fingerprints in Human Heat Pain Thresholds by Use of an Interactive Mixture Model R Toolbox (AdaptGauss).

    PubMed

    Ultsch, Alfred; Thrun, Michael C; Hansen-Goos, Onno; Lötsch, Jörn

    2015-01-01

    Biomedical data obtained during cell experiments, laboratory animal research, or human studies often display a complex distribution. Statistical identification of subgroups in research data poses an analytical challenge. Here were introduce an interactive R-based bioinformatics tool, called "AdaptGauss". It enables a valid identification of a biologically-meaningful multimodal structure in the data by fitting a Gaussian mixture model (GMM) to the data. The interface allows a supervised selection of the number of subgroups. This enables the expectation maximization (EM) algorithm to adapt more complex GMM than usually observed with a noninteractive approach. Interactively fitting a GMM to heat pain threshold data acquired from human volunteers revealed a distribution pattern with four Gaussian modes located at temperatures of 32.3, 37.2, 41.4, and 45.4 °C. Noninteractive fitting was unable to identify a meaningful data structure. Obtained results are compatible with known activity temperatures of different TRP ion channels suggesting the mechanistic contribution of different heat sensors to the perception of thermal pain. Thus, sophisticated analysis of the modal structure of biomedical data provides a basis for the mechanistic interpretation of the observations. As it may reflect the involvement of different TRP thermosensory ion channels, the analysis provides a starting point for hypothesis-driven laboratory experiments. PMID:26516852

  2. Identification of Molecular Fingerprints in Human Heat Pain Thresholds by Use of an Interactive Mixture Model R Toolbox (AdaptGauss)

    PubMed Central

    Ultsch, Alfred; Thrun, Michael C.; Hansen-Goos, Onno; Lötsch, Jörn

    2015-01-01

    Biomedical data obtained during cell experiments, laboratory animal research, or human studies often display a complex distribution. Statistical identification of subgroups in research data poses an analytical challenge. Here were introduce an interactive R-based bioinformatics tool, called “AdaptGauss”. It enables a valid identification of a biologically-meaningful multimodal structure in the data by fitting a Gaussian mixture model (GMM) to the data. The interface allows a supervised selection of the number of subgroups. This enables the expectation maximization (EM) algorithm to adapt more complex GMM than usually observed with a noninteractive approach. Interactively fitting a GMM to heat pain threshold data acquired from human volunteers revealed a distribution pattern with four Gaussian modes located at temperatures of 32.3, 37.2, 41.4, and 45.4 °C. Noninteractive fitting was unable to identify a meaningful data structure. Obtained results are compatible with known activity temperatures of different TRP ion channels suggesting the mechanistic contribution of different heat sensors to the perception of thermal pain. Thus, sophisticated analysis of the modal structure of biomedical data provides a basis for the mechanistic interpretation of the observations. As it may reflect the involvement of different TRP thermosensory ion channels, the analysis provides a starting point for hypothesis-driven laboratory experiments. PMID:26516852

  3. Low-dose oral prolonged-release oxycodone/naloxone for chronic pain in elderly patients with cognitive impairment: an efficacy–tolerability pilot study

    PubMed Central

    Petrò, Emiliano; Ruffini, Elena; Cappuccio, Melania; Guerini, Valeria; Belotti, Gloria; Fascendini, Sara; Licini, Cristina; Marcassa, Claudio

    2016-01-01

    Objective This pilot study evaluated the efficacy and safety of prolonged-release oxycodone/naloxone (OXN-PR) in older subjects with chronic pain and mild-to-moderate cognitive impairment. Methods This was a prospective, observational, open-label study of 45-day duration. Patients with moderate-to-severe chronic pain and naïve to strong opioids were recruited from nursing homes and Alzheimer’s disease centers. OXN-PR was initiated at low doses (5 mg od or bid) and increased to a maximum of 20 mg bid. The primary efficacy endpoint was a pain intensity reduction of ≥30% from baseline (T0) to 15 days after OXN-PR initiation, as assessed by a numerical rating scale or the Pain Assessment in Advanced Dementia scale. Other assessments included the Barthel activities of daily living index, Neuropsychiatric Inventory, Bowel Function Index, and adverse events. Results The analysis included 53 patients (mean age, 83.0 years; mean Mini-Mental State Examination score, 18.6) with severe pain (median Numerical Rating Scale/Pain Assessment in Advanced Dementia 6) and substantial impairment in daily functioning (mean Barthel index, 32.2). The primary endpoint was achieved by 92.4% of patients. OXN-PR significantly reduced mean pain intensity from baseline to study end (numerical rating scale, 6.6±1.0 vs 2.3±1.1, P<0.0001; Pain Assessment in Advanced Dementia, 6.9±1.6 vs 0.9±0.8, P<0.0001). Substantial improvements from T0 to T45 in daily functioning (mean Barthel index, 32.2±16.8 vs 53.7±23.9, P<0.0001) and neuropsychiatric symptoms (mean Neuropsychiatric Inventory, 25.5±27.3 vs 8.8±9.0, P<0.0001) were also reported. OXN-PR was well tolerated and did not worsen bowel function. Conclusion In this pilot study, OXN-PR was effective in improving pain and other symptoms associated with dementia, with a favorable safety and tolerability profile. Large-scale trials in people with dementia are needed to improve clinical guidance for the assessment and treatment of pain in these fragile individuals. PMID:27042069

  4. Nociceptive Flexion Reflex and Pain Rating Responses During Endogenous Opiate Blockade with Naltrexone in Healthy Young Adults

    PubMed Central

    France, Christopher R.; al'Absi, Mustafa; Ring, Christopher; France, Janis L.; Harju, Angie; Wittmers, Lorentz E.

    2007-01-01

    The effect of opioid blockade on nociceptive flexion reflex (NFR) activity and subjective pain ratings was examined in 151 healthy young men and women. Using a within-subjects design, NFR threshold was assessed on two days after administration of either placebo or a 50 mg dose of naltrexone. Electrocutaneous pain threshold and tolerance levels were measured after NFR threshold assessment on each day. Results indicated that administration of naltrexone was consistently associated with hypoalgesic responding. Specifically, participants exhibited lower levels of NFR activity and reported lower pain ratings for electrocutaneous stimulation delivered at pain threshold and tolerance levels following administration of naltrexone as compared to placebo. These findings indicate that opiate blockade using the current standard dose may elicit hypoalgesia. A potential moderating effect of dose of opiate blockade medication and level of endogenous opioid activation should be carefully examined in future research. PMID:17244518

  5. Efficacy and tolerability of low-dose oral prolonged-release oxycodone/naloxone for chronic nononcological pain in older patients

    PubMed Central

    Guerriero, Fabio; Sgarlata, Carmelo; Marcassa, Claudio; Ricevuti, Giovanni; Rollone, Marco

    2015-01-01

    Purpose Chronic pain is highly prevalent in older adults. Increasing evidence indicates strong opioids as a valid option for chronic pain management in geriatrics. The aim of this study was to evaluate efficacy and safety of low-dose oral prolonged-release oxycodone–naloxone (OXN-PR) in patients aged ≥70 years. Methods This open-label prospective study assessed older patients naïve to strong opioids presenting with moderate-to-severe chronic pain. Patients were prescribed OXN-PR at an initial dose of 10/5 mg/day for 28 days. In case of insufficient analgesia, the initial daily dose could be increased gradually. The primary efficacy measure was change in pain intensity from baseline, assessed by a ten-point Numeric Rating Scale (NRS) at day 28 (T28). Changes in cognitive state, daily functioning, quality of life, constipation, and other adverse events were assessed. Results Of 53 patients enrolled (mean 81.7±6.2 years [range 70–92 years]), 52 (98.1%) completed the 28-day observation. At T28, the primary end point (≥30% reduction in mean pain from baseline in the absence of bowel function deterioration) was achieved in 38 patients (71.7%). OXN-PR significantly relieved pain (NRS score –3.26; P<0.0001), as well as daily need for rescue paracetamol (from 86.8% at baseline to 40.4% at T28; P<0.001), and reduced impact of pain on daily activities (Brief Pain Inventory Short Form from 6.2±1.5 to 3.4±2.1; P<0.0001). OXN-PR was also associated with significant improvement in daily functioning (Barthel Index from 53.3±14.1 to 61.3±14.3; P<0.01). No changes were observed in cognitive status and bowel function. OXN-PR was well tolerated; only one patient (1.9%) prematurely withdrew from treatment, due to drowsiness. Conclusion Findings from this open-label prospective study suggest that low-dose OXN-PR may be effective and well tolerated for treatment of moderate-to-severe chronic pain in older patients. Besides its effectiveness, these data indicate that low-dose OXN-PR may be considered a safe analgesic option in this fragile population and warrants further investigation in randomized controlled studies. PMID:25565782

  6. Pain Intensity Recognition Rates via Biopotential Feature Patterns with Support Vector Machines

    PubMed Central

    Gruss, Sascha; Treister, Roi; Werner, Philipp; Traue, Harald C.; Crawcour, Stephen; Andrade, Adriano; Walter, Steffen

    2015-01-01

    Background The clinically used methods of pain diagnosis do not allow for objective and robust measurement, and physicians must rely on the patient’s report on the pain sensation. Verbal scales, visual analog scales (VAS) or numeric rating scales (NRS) count among the most common tools, which are restricted to patients with normal mental abilities. There also exist instruments for pain assessment in people with verbal and / or cognitive impairments and instruments for pain assessment in people who are sedated and automated ventilated. However, all these diagnostic methods either have limited reliability and validity or are very time-consuming. In contrast, biopotentials can be automatically analyzed with machine learning algorithms to provide a surrogate measure of pain intensity. Methods In this context, we created a database of biopotentials to advance an automated pain recognition system, determine its theoretical testing quality, and optimize its performance. Eighty-five participants were subjected to painful heat stimuli (baseline, pain threshold, two intermediate thresholds, and pain tolerance threshold) under controlled conditions and the signals of electromyography, skin conductance level, and electrocardiography were collected. A total of 159 features were extracted from the mathematical groupings of amplitude, frequency, stationarity, entropy, linearity, variability, and similarity. Results We achieved classification rates of 90.94% for baseline vs. pain tolerance threshold and 79.29% for baseline vs. pain threshold. The most selected pain features stemmed from the amplitude and similarity group and were derived from facial electromyography. Conclusion The machine learning measurement of pain in patients could provide valuable information for a clinical team and thus support the treatment assessment. PMID:26474183

  7. Relationship between quantitative sensory testing and pain or disability in people with spinal pain-a systematic review and meta-analysis.

    PubMed

    Hübscher, Markus; Moloney, Niamh; Leaver, Andrew; Rebbeck, Trudy; McAuley, James H; Refshauge, Kathryn M

    2013-09-01

    Sensitization of the nervous system can present as pain hypersensitivity that may contribute to clinical pain. In spinal pain, however, the relationship between sensory hypersensitivity and clinical pain remains unclear. This systematic review examined the relationship between pain sensitivity measured via quantitative sensory testing (QST) and self-reported pain or pain-related disability in people with spinal pain. Electronic databases and reference lists were searched. Correlation coefficients for the relationship between QST and pain intensity or disability were pooled using random effects models. Subgroup analyses and mixed effects meta-regression were used to assess whether the strength of the relationship was moderated by variables related to the QST method or pain condition. One hundred and forty-five effect sizes from 40 studies were included in the meta-analysis. Pooled estimates for the correlation between pain threshold and pain intensity were -0.15 (95% confidence interval [CI]: -0.18 to -0.11) and for disability -0.16 (95% CI: -0.22 to -0.10). Subgroup analyses and meta-regression did not provide evidence that these relationships were moderated by the QST testing site (primary pain/remote), pain condition (back/neck pain), pain type (acute/chronic), or type of pain induction stimulus (eg, mechanical/thermal). Fair correlations were found for the relationship between pain intensity and thermal temporal summation (0.26, 95% CI: 0.09 to 0.42) or pain tolerance (-0.30, 95% CI: -0.45 to -0.13), but only a few studies were available. Our study indicates either that pain threshold is a poor marker of central sensitization or that sensitization does not play a major role in patients' reporting of pain and disability. Future research prospects are discussed. PMID:23711482

  8. Psychological aspects of painful medical conditions in children. I. Developmental aspects and assessment.

    PubMed

    Lavigne, J V; Schulein, M J; Hahn, Y S

    1986-11-01

    The assessment and development of pain in children is reviewed in the first part of a two-part series. Assessment of pain in children has relied on self-report measures that have included visual analogue procedures using concrete stimuli for ratings. Behavioral assessment procedures are more sophisticated, but research on behavioral assessment of pediatric pain has begun to emergy only recently. There has been very little research on the developmental aspects of pain tolerance and pain threshold in children. There are preliminary indications that children's thoughts and attitudes about pain may change with age in a manner that contributes to more intense feelings of pain in adolescence than childhood. Children undergoing painful medical procedures show declining emotional outbursts with age and increasing signs of self-control and muscular rigidity. Possibilities for integrating the study of the developmental aspects of pain with social learning theory, cognitive developmental theory, and the psychology of physical symptom perception are discussed. PMID:3540810

  9. The role of threat-expectancy in acute pain: effects on attentional bias, coping strategy effectiveness and response to pain.

    PubMed

    Boston, Alison; Sharpe, Louise

    2005-12-15

    The aims of this study were threefold. Firstly, to investigate the effect of increasing threat-expectancy on attentional biases towards pain-related words. Secondly, to determine the interaction between threat-expectancy and the effectiveness of two coping strategies on pain threshold and tolerance. Thirdly, to investigate the relationship between fear of pain and the experimental manipulations. One hundred undergraduate psychology students were randomly assigned to receive either threat-increasing or reassuring information about the cold pressor task. After reading the information, all participants completed the dot-probe task for four categories of pain-related words. Following the dot-probe task, participants were randomly allocated to one of two coping strategy conditions (focusing on affective vs sensory aspects of pain). Participants then completed the cold pressor task while engaging in the relevant coping strategy. There was a significant effect of threat on bias towards affective vs sensory pain words. Participants in the threat condition showed a stronger bias towards affective pain words. In contrast, the no-threat condition displayed a stronger bias towards sensory pain words. Significant interaction effects were observed between threat and coping strategy for threshold and tolerance. These results indicated that focusing on sensory pain sensations was helpful in the absence of threat, however, in the presence of threat was relatively unhelpful in comparison to focusing on the affective components of pain. The present results provide support for the fear-avoidance model of pain [Vlaeyen JWS, Linton SJ. Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art. Pain 2000;85:317-332] and confirm the importance of threat-expectancy in hypervigilance towards pain and fear avoidance. PMID:16298490

  10. Assessment of musculoskeletal pain sensitivity and temporal summation by cuff pressure algometry: a reliability study.

    PubMed

    Graven-Nielsen, Thomas; Vaegter, Henrik Bjarke; Finocchietti, Sara; Handberg, Gitte; Arendt-Nielsen, Lars

    2015-11-01

    Chronic musculoskeletal pain is linked with sensitization, and standardized methods for assessment are needed. This study investigated (1) the test-retest reliability of computer-controlled cuff-pressure algometry (pain thresholds and temporal pain summation) on the arm and leg and (2) conditioned pain modulation (CPM) assessed by cuff algometry. The influences of age and gender were evaluated. On 2 different days, cuff pain threshold (cPPT), cuff pain tolerance (cPTT), and temporal summation of pain (TSP) by visual analog scale scores to 10 repeated cuff stimulations at cPTT intensity, as well as pressure pain threshold with handheld pressure algometry, were assessed in 136 healthy subjects. In one session, cuff pain sensitivity was also assessed before and after cold pressor-induced CPM. Good-to-excellent intraclass correlations (0.60-0.90) were demonstrated for manual and cuff algometry, and no systematic bias between sessions was found for cPPT, cPTT, and TSP on the leg and for cPTT and TSP on the arm. Cuff pressure pain threshold and cPTT were higher in men compared with women (P < 0.05). Middle-aged subjects had higher pressure pain threshold, but lower cPPT and cPTT, compared with younger subjects (P < 0.05). Temporal summation of pain was increased in women compared with men (P < 0.05). Cuff algometry was sensitive to CPM demonstrated as increased cPPT and cPTT and reduced TSP (P < 0.05). Reliability and sensitivity of computer-controlled cuff algometry for pain assessment is comparable with manual pressure algometry and constitutes a user-independent method for assessment of pain. Difference in age-related pain sensitivity between manual and cuff algometry should be further investigated. PMID:26172551

  11. Efficacy, safety, and tolerability of fulranumab, an anti-nerve growth factor antibody, in the treatment of patients with moderate to severe osteoarthritis pain.

    PubMed

    Sanga, Panna; Katz, Nathaniel; Polverejan, Elena; Wang, Steven; Kelly, Kathleen M; Haeussler, Juergen; Thipphawong, John

    2013-10-01

    Nerve growth factor (NGF) is increased in chronic pain conditions. This study examined analgesic efficacy and safety of fulranumab, a fully human monoclonal anti-NGF antibody, in adults with chronic osteoarthritis pain. Patients (n=466, intent-to-treat) were randomized to receive, in addition to their current pain therapy, subcutaneous injections in 1 of 6 parallel treatment groups: placebo (n=78), fulranumab 1 mg (n=77) or 3 mg (n=79) every 4 weeks (Q4wk), 3 mg (n=76), 6 mg (n=78), or 10 mg (n=78) every 8 weeks (Q8wk). Primary efficacy results showed that fulranumab significantly reduced the average pain intensity score (P < or = 0.030) from baseline to week 12 compared with placebo in the 3mgQ4wk, 6mgQ8wk, and 10mgQ8wk groups. Secondary efficacy outcomes indicated that significant improvement occurred compared with placebo at week 12 on the Western Ontario and McMaster Universities Osteoarthritis Index subscales of pain, stiffness, and physical function (P < 0.040) across all fulranumab groups except 1mgQ4wk, on the Brief Pain Inventory-Short Form subscales of pain intensity (P < or = 0.016) and pain interference (P < or = 0.030) in the 3mgQ4wk and 10mgQ8wk groups, and on the Patient Global Assessment score (P < or = 0.040) in the 3mgQ4wk, 6mgQ8wk, and 10mgQ8wk groups. The most common (> or = 5% of patients) treatment-emergent adverse events in overall fulranumab groups during the first 12weeks included paresthesia (7%), headache (5%), and nasopharyngitis (5%). Most neurologic-related treatment-emergent adverse events were mild or moderate and resolved at the end of week 12. Serious adverse events occurred in 3 patients, but they were not neurologically related and resolved before study completion. Fulranumab treatment resulted in statistically significant efficacy in pain measures and physical function versus placebo and was generally well tolerated. PMID:23748114

  12. The mirage of impairing drug concentration thresholds: a rationale for zero tolerance per se driving under the influence of drugs laws.

    PubMed

    Reisfield, Gary M; Goldberger, Bruce A; Gold, Mark S; DuPont, Robert L

    2012-06-01

    Motor vehicle crashes are a leading cause of morbidity and mortality in the United States. Drivers with measurable quantities of potentially impairing illicit or prescription drugs in their body fluids are multiple times more likely to be involved in motor vehicle crashes than those without such drugs in their bodies. Drug-related impairment, however, cannot be inferred solely on the basis of the presence of drugs in biological fluids. Thus, for more than a quarter century, there has been a search for drug blood concentrations that are the equivalent of the 0.08 g/dL threshold for alcohol-impaired driving in the United States. We suggest that such equivalents are a mirage, and cannot be determined due to variable drug tolerance, lack of consistent relationships between drug blood concentrations and impairment, innumerable drug combinations and multiple other factors. Thus, while the idea of determining impairing drug concentrations is attractive, it is ultimately unattainable, and withholding drugged driving legislation pending the acquisition of such data is tantamount to a plan for inaction with regard to an important and growing public health and safety problem. We propose specific legislation to address alcohol- and drug-impaired driving in the United States. PMID:22582272

  13. An Endogenous Pain Control System Is Altered In Subjects With Interstitial Cystitis

    PubMed Central

    Ness, Timothy J; Lloyd, L. Keith; Fillingim, Roger B.

    2016-01-01

    Purpose Multiple studies have demonstrated that in healthy subjects painful stimuli applied to one part of the body inhibit pain sensation in other parts of the body, a phenomenon referred to as conditioned pain modulation (CPM). CPM is related to the presence of endogenous pain control systems. Studies have demonstrated deficits in CPM-associated inhibition in many, but not all chronic pain disorders. The present study sought to determine whether CPM was altered in subjects with Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS). Methods and Materials Female subjects with and without the diagnosis of IC/BPS were studied psychophysically using quantitative cutaneous thermal, forearm ischemia and ice water immersion tests. CPM was assessed by quantifying the effects of immersion of the hand in ice water (conditioning stimulus) on threshold and tolerance of cutaneous heat pain (test stimulus) applied to the contralateral lower extremity. Results CPM responses of the subjects with IC/BPS were statistically different from those of healthy control subjects for both cutaneous thermal threshold and tolerance measures. Healthy control subjects demonstrated statistically significant increases in their thermal pain tolerances whereas subjects with the diagnosis of IC/BPS demonstrated statistically significant reductions in their thermal pain tolerances. Conclusions An endogenous pain inhibitory system normally observed with CPM was altered in subjects with IC/BPS. This identifies IC/BPS as similar to several other chronic pain disorders such as fibromyalgia and irritable bowel syndrome and suggests that a deficit in endogenous pain inhibitory systems may be a contributor to such chronic pain disorders. PMID:23973521

  14. Pulmonary responses during cold induced acute pain.

    PubMed

    Tandon, O P; Himani, A; Singh, S

    1997-01-01

    Cold induced acute pain is associated with many autonomic responses of the cardiovascular system, skin conductance and pupil size. However, there are few reports suggesting changes in pulmonary function. Hence present study reports preliminary data on this. Acute pain was induced in 30 non-smoker males, 30-50 yrs of age by immersing hand in cold water and their respiratory rate (RR), tidal volume (TV), inspiratory and expiratory reserve volumes (IRV, ERV) and respective capacities, vital capacity (VC), force vital capacity (FVC), FEV1%, peak flow and flow rates at 75%, 50% and 25% of expired volume (V75,50,25) were measured. Acute pain parameters like pain threshold, tolerance and sensitivity were also recorded. Besides these, heart rate, blood pressure (systolic and diastolic), skin temperature of forehead and opposite palm were also measured. Comparisons were made between values recorded before, during and after cold induced pain. An increase in RR, RV, IC, EC, FVC, FVC%, FEV1 was observed during cold induced pain reflecting an acute state of sympathetic dominance. Positive correlations between heart rate and respiratory rate, and other respiratory with pain parameters were seen during period of induction of acute pain. Hence the study indicates that alterations in pulmonary profile form a part of multidimensional responses observed during cold induced acute pain. PMID:10225027

  15. Effect of spinal monoaminergic neuronal system dysfunction on pain threshold in rats, and the analgesic effect of serotonin and norepinephrine reuptake inhibitors.

    PubMed

    Tamano, Ryuta; Ishida, Mitsuhiro; Asaki, Toshiyuki; Hasegawa, Minoru; Shinohara, Shunji

    2016-02-26

    Dysfunction in the central serotonin (5-HT) and norepinephrine (NE) systems cause depression and pain. Descending spinal pain modulatory pathways are important in the analgesic mechanisms of antidepressants, particularly serotonin and norepinephrine reuptake inhibitors (SNRIs). While many non-clinical studies have demonstrated the roles of central monoaminergic systems in pain, there is little evidence to illuminate the direct contribution of spinal descending pain modulatory systems independently of depressive-like behavior. To examine the effects of dysfunction of spinal monoaminergic systems on pain sensitivity, we established a rat chronic pain model by administering lumbar-intrathecal reserpine to minimize its influence on brain. Lumbar-intrathecal reserpine evoked persistent mechanical hypersensitivity and corresponding reductions in spinal 5-HT and NE concentrations (from 767.2 to 241.6ng/g and from 455.9 to 41.7ng/g, respectively after reserpine 30nmol). Lumbar-intrathecal reserpine did not deplete brain monoamines or bring about depressive-like behavior in the forced swim test. Spinal monoamines depletion-induced pain sensitivity was ameliorated by lumbar-intrathecal administration of the SNRIs (duloxetine and milnacipran) in dose-dependent manners. These suggest that increased pain sensitivity could be induced by dysfunction solely of the descending pain modulatory system, regardless of depressive-like behavior, and lumbar-intrathecal administration of SNRIs could ameliorate the pain sensitivity which might be mediated by affecting the descending pain modulatory system in the spinal cord, not via their antidepressant effects. PMID:26806036

  16. A meta-analysis on pain sensitivity in self-injury.

    PubMed

    Koenig, J; Thayer, J F; Kaess, M

    2016-06-01

    Individuals engaging in self-injurious behavior (SIB) frequently report absence of pain during acts of SIB. While altered pain sensitivity is discussed as a risk factor for the engagement in SIB, results have been mixed with considerable variance across reported effect sizes, in particular with respect to the effect of co-morbid psychopathology. The present meta-analysis aimed to summarize the current evidence on pain sensitivity in individuals engaging in SIB and to identify covariates of altered pain processing. Three databases were searched without restrictions. Additionally a hand search was performed and reference lists of included studies were checked for potential studies eligible for inclusion. Thirty-two studies were identified after screening 720 abstracts by two independent reviewers. Studies were included if they reported (i) an empirical investigation, in (ii) humans, including a sample of individuals engaging in (iii) SIB and a group of (iv) healthy controls, (v) receiving painful stimulation. Random-effects meta-analysis was performed on three pain-related outcomes (pain threshold, pain tolerance, pain intensity) and several population- and study-level covariates (i.e. age, sex, clinical etiology) were subjected to meta-regression. Meta-analysis revealed significant main effects associated with medium to large effect sizes for all included outcomes. Individuals engaging in SIB show greater pain threshold and tolerance and report less pain intensity compared to healthy controls. Clinical etiology and age are significant covariates of pain sensitivity in individuals engaging in SIB, such that pain threshold is further increased in borderline personality disorder compared to non-suicidal self-injury. Mechanisms underlying altered pain sensitivity are discussed. PMID:26964517

  17. Asians Differ from non-Hispanic Whites in Experimental Pain Sensitivity

    PubMed Central

    Rowell, Lauren N.; Mechlin, Beth; Ji, Ellen; Addamo, Michael; Girdler, Susan S.

    2011-01-01

    This study examined differences between Asians and non-Hispanic Whites (Whites) in pain sensitivity, and its relationship to mean arterial pressure (MAP) and heart rate (HR). In 30 Whites (50% female) and 30 Asians (50% female), experimental pain sensitivity was assessed with a hand cold pressor task, yielding measures of pain threshold, tolerance, intensity, and unpleasantness. Mean arterial pressure and HR measurements taken at rest and in response to speech stress were assessed. Perceived stress, anxiety, perfectionism, parental criticism, parental expectations and depressive symptoms were also measured. The results indicated that for the cold pain test, Asians demonstrated significantly lower pain threshold and tolerance levels than Whites. Although no ethnic differences were seen for MAP or HR responses to stress, for whites higher stress MAP levels were correlated with reduced pain sensitivity, while for Asians higher baseline and stress HR levels were correlated with reduced pain sensitivity. Asians reported higher parental expectations and greater parental criticism than Whites. For Asians only, higher levels of perfectionism were related to more depressive symptoms, anxiety and perceived stress. These results indicate that Asian Americans are more sensitive to experimental pain than Whites and suggest ethnic differences in endogenous pain regulatory mechanisms (e.g. MAP and HR). The results may also have implications for understanding ethnic differences in clinical pain. PMID:21561793

  18. Altered Pain Sensitivity in Elderly Women with Chronic Neck Pain

    PubMed Central

    Uthaikhup, Sureeporn; Prasert, Romchat; Paungmali, Aatit; Boontha, Kritsana

    2015-01-01

    Background Age-related changes occur in both the peripheral and central nervous system, yet little is known about the influence of chronic pain on pain sensitivity in older persons. The aim of this study was to investigate pain sensitivity in elders with chronic neck pain compared to healthy elders. Methods Thirty elderly women with chronic neck pain and 30 controls were recruited. Measures of pain sensitivity included pressure pain thresholds, heat/cold pain thresholds and suprathreshold heat pain responses. The pain measures were assessed over the cervical spine and at a remote site, the tibialis anterior muscle. Results Elders with chronic neck pain had lower pressure pain threshold over the articular pillar of C5-C6 and decreased cold pain thresholds over the cervical spine and tibialis anterior muscle when compared with controls (p < 0.05). There were no between group differences in heat pain thresholds and suprathreshold heat pain responses (p > 0.05). Conclusion The presence of pain hypersensitivity in elderly women with chronic neck pain appears to be dependent on types of painful stimuli. This may reflect changes in the peripheral and central nervous system with age. PMID:26039149

  19. Pain Assessment

    MedlinePlus

    ... Pain Pain Assessment Pain Treatments Integrative Pain Therapy Pain Management Recommendations References May 31, 2016 Pain Assessment Effective pain management begins with a comprehensive assessment. This assessment allows ...

  20. Efficacy of long-term milnacipran treatment in patients meeting different thresholds of clinically relevant pain relief: subgroup analysis of a randomized, double-blind, placebo-controlled withdrawal study

    PubMed Central

    Mease, Philip J; Clauw, Daniel J; Trugman, Joel M; Palmer, Robert H; Wang, Yong

    2014-01-01

    Background Fibromyalgia patients from a long-term, open-label study of milnacipran (50–200 mg/day) were eligible to participate in a 12-week, randomized, placebo-controlled withdrawal study. The withdrawal study evaluated loss of therapeutic response in patients who achieved ≥50% pain improvements after receiving up to 3.25 years of milnacipran. This post-hoc analysis investigated whether patients who met lower thresholds of pain improvement also experienced worsening of fibromyalgia symptoms upon treatment withdrawal. Method Among patients who received milnacipran ≥100 mg/day during the long-term study, three subgroups were identified based on percentage of pain reduction at randomization: ≥50% (protocol-defined “responders”; n=150); ≥30% to <50% (patients with clinically meaningful pain improvement; n=61); and <30% (n=110). Efficacy assessments included the visual analog scale (VAS) for pain, Fibromyalgia Impact Questionnaire-Revised (FIQR), 36-Item Short-Form Health Survey Physical Component Summary (SF-36 PCS), and Beck Depression Inventory (BDI). Results In the ≥30 to <50% subgroup, significant worsening in pain was detected after treatment withdrawal. The difference between placebo and milnacipran in mean VAS score changes for this subgroup (+9.0, P<0.05) was similar to the difference in protocol-defined responders (+9.4, P<0.05). In the <30% subgroup, no worsening in pain was observed in either treatment arm. However, patients in this subgroup experienced significant worsening in FIQR scores after treatment withdrawal (placebo, +6.9; milnacipran, −2.8; P<0.001), as well as worsening in SF-36 PCS and BDI scores. Conclusion Patients who experienced ≥30% to <50% pain reduction with long-term milnacipran had significant worsening of fibromyalgia symptoms after treatment withdrawal. These results suggest that the conventional ≥30% pain responder cutoff may be adequate to demonstrate efficacy in randomized withdrawal studies of fibromyalgia. Patients in the <30% pain reduction subgroup had worsening scores on the FIQR and other multidimensional measures after treatment withdrawal, indicating the importance of identifying and managing the multiple symptoms of fibromyalgia. PMID:25473309

  1. Gender expression, sexual orientation and pain sensitivity in women

    PubMed Central

    Vigil, Jacob M; Rowell, Lauren N; Lutz, Charlotte

    2014-01-01

    BACKGROUND: Despite a growing body of literature investigating sex differences with regard to pain, surprisingly little research has been conducted on the influence of various aspects of self-identity, including gender expression and sexual orientation, on pain sensitivity within each sex, particularly among women. In men, dispositional femininity is linked to greater clinical pain and trait masculinity is associated with higher pain thresholds. OBJECTIVES: To examine whether gender expression and sexual orientation are associated with within-sex differences in ischemic pain sensitivity in healthy young women. METHODS: A convenience sample of 172 females (mean age 21.4 years; range 18 to 30 years of age; 56.0% white, 89% heterosexual) performed an ischemic pain task in counterbalanced order. Desired levels of dispositional femininity for a preferred romantic partner and self-described levels of personal dispositional femininity were measured. RESULTS: Compared with heterosexual women, lesbian and bisexual women reported lower pain intensity ratings early in the discomfort task. Irrespective of sexual orientation, attraction to more feminine romantic partners and dispositional masculinity were correlated with lower pain intensity, and with higher pain thresholds and tolerance levels. DISCUSSION: These preliminary findings suggest that within-sex differences in sexual orientation and other aspects of identity, irrespective of biological sex, may be important to consider when examining experimental pain performance and clinical pain experiences. CONCLUSION: Larger investigations of the psychophysiological relationships among sexual orientation, gender expression and pain sensitivity are warranted. These findings may have implications for differences in clinical pain sensitivity of lesbian and bisexual women compared with heterosexual women. PMID:24575419

  2. Pain sensitivity and opioid analgesia: a pharmacogenomic twin study.

    PubMed

    Angst, Martin S; Phillips, Nicholas G; Drover, David R; Tingle, Martha; Ray, Amrita; Swan, Gary E; Lazzeroni, Laura C; Clark, J David

    2012-07-01

    Opioids are the cornerstone medication for the management of moderate to severe pain. Unfortunately, vast inter-individual differences in dose requirements complicate their effective and safe clinical use. Mechanisms underlying such differences are incompletely understood, are likely multifactorial, and include genetic and environmental contributions. While accumulating evidence suggests that variants of several genes account for some of the observed response variance, the relative contribution of these factors remains unknown. This study used a twin paradigm to provide a global estimate of the genetic and environmental contributions to inter-individual differences in pain sensitivity and analgesic opioid effects. Eighty one monozygotic and 31 dizygotic twin pairs successfully underwent a computer-controlled infusion with the μ-opioid agonist alfentanil in a single occasion, randomized, double-blind and placebo-controlled study design. Pain sensitivity and analgesic effects were assessed with experimental heat and cold pressor pain models along with important covariates including demographic factors, depression, anxiety, and sleep quality. Significant heritability was detected for cold pressor pain tolerance and opioid-mediated elevations in heat and cold pressor pain thresholds. Genetic effects accounted for 12-60% of the observed response variance. Significant familial effects accounting for 24-32% of observed variance were detected for heat and cold pressor pain thresholds and opioid-mediated elevation in cold pressor pain tolerance. Significant covariates included age, gender, race, education, and anxiety. Results provide a strong rationale for more detailed molecular genetic studies to elucidate mechanisms underlying inter-individual differences in pain sensitivity and analgesic opioid responses. Such studies will require careful consideration of the studied pain phenotype. PMID:22444188

  3. [Pain therapy].

    PubMed

    Donnadieu, S; Djian, M C

    1998-12-12

    NEW OPIOID ANALGESICS: Progress in pain reliet has recently been achieved with the introduction of new opioid analgesics such as tramadol and the pediatric preparation of codeine phosphate as well as powerful long-release opioids which can be administered per os, or percutaneously for transdermal fentanyl. CO-ANALGESICS: Other drugs, mainly antidepressants and anti-convulsants, can be usefully combined with analgesics. New serotonin uptake inhibitors and anticonvulsants (gabapentin and lamotrigin) have the advantage of better tolerance. None of these drugs has marketing approval in France for their pain relieving effects. The same is true for clonidine and neostigmine which, after spinal infusion, potentialize opioids and for ketamine which can relieve neuropathy pain by dissociative anesthesia. NEW ANTI-MIGRAINE DRUGS: New drugs have been developed for specific types of pain such as migraine. The new "triptans" are tolerated better than sumatriptan and is reimbursed by the national social security. REFRACTORY NEUROPATHY PAIN: Indications for electrical stimulation techniques conducted in a neurosurgery unit have been identified. Stimulators may be implanted in spinal or supra-spinal localizations. REGULATORY ASPECTS: New legislation has reorganized health care for pain relief in France. The new texts take into consideration personnel training, the health care network and progress in therapeutics. PMID:9893699

  4. Increased Sensitivity to Thermal Pain and Reduced Subcutaneous Lidocaine Efficacy in Redheads

    PubMed Central

    Liem, Edwin B.; Joiner, Teresa V.; Tsueda, Kentaro; Sessler, Daniel I.

    2005-01-01

    Background: Anesthetic requirement in redheads is exaggerated, suggesting that redheads may be especially sensitive to pain. We therefore tested the hypotheses that women with natural red hair are more sensitive to pain, and that redheads are resistant to topical and subcutaneous lidocaine. Methods: We evaluated pain sensitivity in red-haired (n=30) or dark-haired (n=30) women by determining the electrical current perception threshold, pain perception, and maximum pain tolerance with a Neurometer CPT/C (Neurotron, Inc., Baltimore, MD). We evaluated the analogous warm and cold temperature thresholds with the TSA-II Neurosensory Analyzer (Medoc Ltd., Minneapolis, MN). Volunteers were tested with both devices at baseline and with the Neurometer after 1-hour exposure to 4% liposomal lidocaine and after subcutaneous injection of 1% lidocaine. Data are presented as medians [interquartile ranges]. Results: Current perception, pain perception, and pain tolerance thresholds were similar in the red-haired and dark-haired women at 2000, 250, and 5 Hz. In contrast, redheads were more sensitive to cold pain perception (22.6°C [15.1, 26.1] vs. 12.6°C [0, 20], P=0.004), cold pain tolerance (6.0°C [0, 9.7] vs. 0.0°C [0.0, 2.0], P=0.001), and heat pain (46.3°C [45.7, 47.5] vs. 47.7°C [46.6, 48.7], P=0.009). Subcutaneous, lidocaine was significantly less effective in redheads, e.g., pain tolerance threshold at 2000 Hz stimulation in redheads was 11.0 mA [8.5, 16.5] vs. >20.0 mA [14.5, >20] in others, P=0.005). Conclusion: Red hair is the phenotype for mutations of the melanocortin 1 receptor. Our results indicate that redheads are more sensitive to thermal pain and are resistant to the analgesic effects of subcutaneous lidocaine. Mutations of the melanocortin 1 receptor, or a consequence thereof, thus modulate pain sensitivity. PMID:15731586

  5. The Relationship Between Neck Pain and Physical Activity

    PubMed Central

    Cheung, Janice; Kajaks, Tara; MacDermid, Joy C.

    2013-01-01

    Neck pain is a significant societal burden due to its high prevalence and healthcare costs. While physical activity can help to manage other forms of chronic musculoskeletal pain, little data exists on the relationship between physical activity and neck pain. The purpose of this study was to compare physical activity levels between individuals with neck pain and healthy controls, and then to relate disability, fear of movement, and pain sensitivity measures to physical activity levels in each of the two participant groups. 21 participants were recruited for each of the two participant groups (n = 42). Data collection included the use of the Neck Disability Index, the Tampa Scale for Kinesiophobia, electrocutaneous (Neurometer® CPT) and pressure stimulation (JTech algometer) for quantitative sensory testing, and 5 days of subjective (Rapid Assessment of Physical Activity) and objective (BioTrainer II) measurements of physical activity. Analysis of Variance and Pearson’s Correlation were used to determine if differences and relationships exist between dependent variables both within and between groups. The results show that individuals with mild neck pain and healthy controls do not differ in subjectively and objectively measured physical activity. While participants with neck pain reported higher neck disability and fear of movement, these factors did not significantly relate to physical activity levels. Perceived activity level was related to pain threshold and tolerance at local neck muscles sites (C2 paraspinal muscle and upper trapezius muscle), whereas measured activity was related to generalized pain sensitivity, as measured at the tibialis anterior muscle site. PMID:24133553

  6. Swearing as a response to pain.

    PubMed

    Stephens, Richard; Atkins, John; Kingston, Andrew

    2009-08-01

    Although a common pain response, whether swearing alters individuals' experience of pain has not been investigated. This study investigated whether swearing affects cold-pressor pain tolerance (the ability to withstand immersing the hand in icy water), pain perception and heart rate. In a repeated measures design, pain outcomes were assessed in participants asked to repeat a swear word versus a neutral word. In addition, sex differences and the roles of pain catastrophising, fear of pain and trait anxiety were explored. Swearing increased pain tolerance, increased heart rate and decreased perceived pain compared with not swearing. However, swearing did not increase pain tolerance in males with a tendency to catastrophise. The observed pain-lessening (hypoalgesic) effect may occur because swearing induces a fight-or-flight response and nullifies the link between fear of pain and pain perception. PMID:19590391

  7. Effects of Videogame Distraction using a Virtual Reality Type Head-Mounted Display Helmet on Cold Pressor Pain in Children

    PubMed Central

    Weiss, Karen E.; Dillinger Clendaniel, Lindsay; Law, Emily F.; Ackerman, Claire Sonntag; McKenna, Kristine D.

    2009-01-01

    Objective?To test whether a head-mounted display helmet enhances the effectiveness of videogame distraction for children experiencing cold pressor pain.?Method?Forty-one children, aged 614 years, underwent one or two baseline cold pressor trials followed by two distraction trials in which they played the same videogame with and without the helmet in counterbalanced order. Pain threshold (elapsed time until the child reported pain) and pain tolerance (total time the child kept the hand submerged in the cold water) were measured for each cold pressor trial.?Results?Both distraction conditions resulted in improved pain tolerance relative to baseline. Older children appeared to experience additional benefits from using the helmet, whereas younger children benefited equally from both conditions. The findings suggest that virtual reality technology can enhance the effects of distraction for some children. Research is needed to identify the characteristics of children for whom this technology is best suited. PMID:18367495

  8. Adaptive Thresholds

    Energy Science and Technology Software Center (ESTSC)

    2014-08-26

    ADAPT is a topological analysis code that allow to compute local threshold, in particular relevance based thresholds for features defined in scalar fields. The initial target application is vortex detection but the software is more generally applicable to all threshold based feature definitions.

  9. A randomized, double blind, placebo controlled, cross over study to evaluate the analgesic activity of Boswellia serrata in healthy volunteers using mechanical pain model

    PubMed Central

    Prabhavathi, K.; Chandra, U. Shobha Jagdish; Soanker, Radhika; Rani, P. Usha

    2014-01-01

    Objective: Experimental pain models in human healthy volunteers are advantageous for early evaluation of analgesics. All efforts to develop nonsteroidal anti-inflammatory drugs (NSAIDs) which are devoid of gastrointestinal and cardiovascular system effects are still far from achieving a breakthrough. Hence we evaluated the analgesic activity of an ayurvedic drug, Boswellia serrata by using validated human pain models which has shown its analgesic activity both in-vitro and preclinical studies to evaluate the analgesic activity of single oral dose (125 mg, 2 capsules) of Boswellia serrata compared to placebo using mechanical pain model in healthy human subjects. Materials and Methods: After taking written informed consent, twelve healthy subjects were randomized (1:1) to receive single oral dose of Boswellia serrata (Shallaki) 125 mg, 2 capsules or identical placebo in a crossover design. Mechanical pain was assessed using Ugo basile analgesymeter (by Randall Selitto test) at baseline and at 1 hr, 2 hrs and 3 hrs after test drug administration. Pain Threshold force and time and Pain Tolerance force and time were evaluated. Statistical analysis was done by paired t-test. Results: Twelve healthy volunteers have completed the study. Mean percentage change from baseline in Pain Threshold force and time with Boswellia serrata when compared to placebo had significantly increased [Force: 9.7 11.0 vs 2.9 3.4 (P = 0.05) and time: 9.7 10.7 vs 2.8 3.4 (P = 0.04)] at third hr. Mean Percentage change from baseline in Pain Tolerance force and time with Boswellia serrata when compared to placebo had significantly (P ? 0.01) increased at 1 hr, 2 hrs and 3 hrs. Conclusion: In the present study, Boswellia serrata significantly increased the Pain Threshold and Pain Tolerance force and time compared to placebo. Both study medications were well tolerated. Further multiple dose studies may be needed to establish the analgesic efficacy of the drug. PMID:25298573

  10. Pain Sensitivity in Adolescent Males with Attention-Deficit/Hyperactivity Disorder: Testing for Associations with Conduct Disorder and Callous and Unemotional Traits

    PubMed Central

    Northover, Clare; Thapar, Anita; Langley, Kate; van Goozen, Stephanie HM

    2015-01-01

    Background Reduced processing and experience of aversive emotional cues is a common component of theories on the development and persistence of aggression and antisocial behaviour. Yet physical pain, arguably the most basic aversive cue, has attracted comparatively little attention. Methods This study measured pain sensitivity and physiological response to painful stimuli (skin conductance level, SCL) in adolescent boys with Attention-Deficit/Hyperactivity Disorder (ADHD; n = 183), who are at high risk for antisocial behaviour. We compared boys with ADHD with and without a comorbid diagnosis of Conduct Disorder (CD) on pain sensitivity, and examined patterns of association between pain measures, on the one hand, and problem severity and callous and unemotional (CU) traits, on the other. Results Boys with comorbid CD exhibited a higher pain threshold and tolerance than boys with ADHD alone, but the groups did not differ in physiology at the time the pain threshold and tolerance were reported. Regression analyses showed that ADHD problem severity positively predicted pain sensitivity, whereas levels of CU traits negatively predicted pain sensitivity. Conclusions These findings on physical pain processing extend evidence of impairments in aversive cue processing among those at risk of antisocial behaviour. The study highlights the importance of considering comorbidity and heterogeneity of disorders when developing interventions. The current findings could be used to identify subgroups within those with ADHD who might be less responsive to interventions that use corrective feedback to obtain behaviour change. PMID:26225935

  11. Evidence for threshold effects of 25-hydroxyvitamin D on glucose tolerance and insulin resistance in black and white obese postmenopausal women.

    PubMed

    Sorkin, John D; Vasaitis, Tadas Sean; Streeten, Elizabeth; Ryan, Alice S; Goldberg, Andrew P

    2014-05-01

    We identified normal vs. abnormal 25-hydroxyvitamin D [25(OH)D] concentrations by examining the relation of 25(OH)D to non-bone-related measures (plasma glucose, insulin resistance, lipids, blood pressure, fitness, obesity, and regional adiposity) and asking whether there is a 25(OH)D concentration above and below which the relation between 25(OH)D and outcome changes. We examined the relation between 25(OH)D and outcome by race to see whether race-specific normal ranges are needed, and we examined the role of insulin-like growth factor-1 (IGF-1) in modulating the relation between 25(OH)D and outcome. In a cross-sectional study of 239 overweight and obese, sedentary postmenopausal women without diabetes (83 black, 156 white), outcome measures included plasma lipids, glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), IGF-1, parathyroid hormone (PTH), aerobic fitness, body composition, subcutaneous abdominal and visceral fat, and blood pressure. We identified threshold effects in the association between 25(OH)D and these variables using piecewise linear regressions. We found that 25(OH)D was inversely related to fasting glucose, fasting and 2-h insulin, HOMA-IR, visceral abdominal fat, percentage fat, PTH, and triglycerides. Evidence for a threshold effect of 25(OH)D was found for 2-h glucose, 2-h insulin, fasting insulin, and HOMA-IR. There was no evidence suggesting the need for race-specific normal 25(OH)D concentrations. IGF-1 modulated the relation between 25(OH)D and outcome but only below, and not above, a threshold 25(OH)D concentration. Our findings suggest a threshold effect of 25(OH)D on glucose-insulin metabolism such that 25(OH)D ≥ ∼26 μg/L (65.0 pmol/L) supports normal glucose homeostasis and that the same cut point defining normal 25(OH)D concentration can be used in black and white women. This study was registered at clinicaltrials.gov as NCT01798030. PMID:24717362

  12. Evidence for Threshold Effects of 25-Hydroxyvitamin D on Glucose Tolerance and Insulin Resistance in Black and White Obese Postmenopausal Women12

    PubMed Central

    Sorkin, John D.; Vasaitis, Tadas Sean; Streeten, Elizabeth; Ryan, Alice S.; Goldberg, Andrew P.

    2014-01-01

    We identified normal vs. abnormal 25-hydroxyvitamin D [25(OH)D] concentrations by examining the relation of 25(OH)D to non-bone–related measures (plasma glucose, insulin resistance, lipids, blood pressure, fitness, obesity, and regional adiposity) and asking whether there is a 25(OH)D concentration above and below which the relation between 25(OH)D and outcome changes. We examined the relation between 25(OH)D and outcome by race to see whether race-specific normal ranges are needed, and we examined the role of insulin-like growth factor-1 (IGF-1) in modulating the relation between 25(OH)D and outcome. In a cross-sectional study of 239 overweight and obese, sedentary postmenopausal women without diabetes (83 black, 156 white), outcome measures included plasma lipids, glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), IGF-1, parathyroid hormone (PTH), aerobic fitness, body composition, subcutaneous abdominal and visceral fat, and blood pressure. We identified threshold effects in the association between 25(OH)D and these variables using piecewise linear regressions. We found that 25(OH)D was inversely related to fasting glucose, fasting and 2-h insulin, HOMA-IR, visceral abdominal fat, percentage fat, PTH, and triglycerides. Evidence for a threshold effect of 25(OH)D was found for 2-h glucose, 2-h insulin, fasting insulin, and HOMA-IR. There was no evidence suggesting the need for race-specific normal 25(OH)D concentrations. IGF-1 modulated the relation between 25(OH)D and outcome but only below, and not above, a threshold 25(OH)D concentration. Our findings suggest a threshold effect of 25(OH)D on glucose–insulin metabolism such that 25(OH)D ≥ ∼26 μg/L (65.0 pmol/L) supports normal glucose homeostasis and that the same cut point defining normal 25(OH)D concentration can be used in black and white women. This study was registered at clinicaltrials.gov as NCT01798030. PMID:24717362

  13. Diffuse noxious inhibitory control evoked by tonic craniofacial pain in humans.

    PubMed

    Sowman, P F; Wang, K; Svensson, P; Arendt-Nielsen, L

    2011-02-01

    Tonic pain in one body segment can inhibit the perception of pain in another body segment. This phenomenon is mediated by diffuse noxious inhibitory controls (DNIC), and its efficacy in craniofacial regions is investigated in this study. A compressive device that evoked a tonic, moderate/severe, headache-like, conditioning pain (∼8/10 on a visual analogue scale) was applied for 15min. Eleven males participated in the study. Pressure pain threshold (PPT) and pressure pain tolerance (PPTol) at multiple heterosegmental body sites (right masseter, splenius capitis, second intermediate phalange, brachioradialis and tibialis anterior) were measured before, during and at multiple time points (5, 20 and 35min) after the termination of the conditioning pain. PPTs and PPTols were compared within participants across two experimental sessions; one that included painful conditioning stimulation, and a separate control session on a different day. Painful conditioning increased PPT significantly during pain over the masseter (p<0.05) and over the tibialis anterior (p<0.01). PPTol was unchanged. In the period after the painful conditioning stimulation PPT was depressed compared to control. This study shows that pain evoked from the craniofacial region evokes DNIC-like mechanisms on segmental as well as heterosegmental sites. PMID:20615731

  14. Effect of verbal persuasion on self-efficacy for pain-related diagnostic sensory testing in individuals with chronic neck pain and healthy controls - a randomized, controlled trial.

    PubMed

    Söderlund, Anne; Sterling, Michele

    2016-01-01

    The aim of this study was to investigate the differences in cold pain threshold (CTh), pressure pain threshold (PPT), cold pain tolerance (CPTo) tests, and the level of self-efficacy when self-efficacy for diagnostic sensory testing was manipulated by verbal persuasion before a testing situation in persons with neck pain and in healthy controls. A randomized experimental design was used. Twenty-one healthy volunteers and 22 individuals with either traumatic or nontraumatic chronic neck pain were recruited to participate in the study. The intervention consisted of two experimental verbal persuasion conditions: Increase self-efficacy and Decrease self-efficacy. The PPT was measured using a pressure algometer, the CTh was measured using a thermo test system, and CPTo was measured by submerging the participant's hand in ice water up to the elbow joint. On three occasions, the participants reported their self-efficacy level in performing the sensory tests. In the chronic neck pain group, there were no differences in pain threshold or tolerance. There was a difference in the self-efficacy level after verbal persuasion between the experimental conditions. In the healthy control group, the CThs increased following the condition that aimed to increase self-efficacy. No other differences were observed in the healthy controls. A short verbal persuasion in the form of manipulative instructions seems to have a marginal effect on the individual's self-efficacy levels in the chronic neck pain group and a slight influence on the results of sensory testing in healthy controls. PMID:27022298

  15. Pain management.

    PubMed

    Ripamonti, C I

    2012-09-01

    Despite published guidelines and educational programs on the assessment and treatment of cancer-related pain, in any stage of oncological disease, unrelieved pain continues to be a substantial worldwide public health concern either in patients with solid and haematological malignancies. The proper and regular self-reporting assessment of pain is the first step for an effective and individualized treatment. Opioids are the mainstay of analgesic therapy and can be associated with non-opioids drugs such as paracetamol or non-steroidal anti-inflammatory drugs and to adjuvant drugs (for neuropathic pain and symptom control). The role and the utility of weak opioids (i.e. codeine, dihydrocodeine, tramadol) are a controversy point. Morphine has been placed by World Health Organization on its Essential Drug List. In the comparative study with other strong opioids (hydromorphone, oxycodone), there is no evidence to show superiority or inferiority with morphine as the first choice opioid. Oral methadone is a useful and safe alternative to morphine. Methadone presents the potential to control pain difficult to manage with other opioids. although the oral route of opioid administration is considered the one of choice, intravenous, subcutaneous, rectal, transdermal, sublingual, intranasal, and spinal routes must be used in particular situation. Transdermal opioids such as fentanyl and buprenorphine are best reserved for patients whose opioid requirements are stable. Switching from one opioid to another can improve analgesia and tolerability. PMID:22987980

  16. The effect of visual stimulation via the eyeglass display and the perception of pain.

    PubMed

    Tse, Mimi M Y; Ng, Jacobus K F; Chung, Joanne W Y; Wong, Thomas K S

    2002-02-01

    Hospitalization involves anxiety and pain for many people. Unfamiliar hospital settings, various diagnostic and therapeutic procedures, and the sight and sounds of medical procedures exacerbate pain and anxiety. By blocking off the anxiety-inducing sights and sounds of the hospital surroundings and creating a pleasant environment, an eyeglass display might be able to change the sensation and perception of pain. In this randomized, controlled, crossover study, 72 healthy university student volunteers were asked to wear a light-weight eyeglass that projected a feeling of watching a 52-inch television screen at 6 1/2 feet in distance while pain was produced by a modified tourniquet technique. Subjects were randomly assigned to participate in a V-session or B-session first, with subsequent cross-over. In a V-session, subjects were instructed to wear the eyeglass and watch the soundless display of natural scenery during the inflation. In a B-session, the eyeglass that subjects wore would project a static blank screen. During V-sessions, there was a significant increase in pain threshold (p < 0.001) and pain tolerance (p < 0.001). The degree of immersion was positively correlated with improvement in pain threshold, whereas the anxiety level was negatively correlated with improvement in pain threshold. These findings have implications for using visual stimulation as a positive adjunct to other methods of pain relief and for different pain conditions. This study was considered to be the pioneer use of visual stimulation in the local Chinese community as an adjunct to pain relief. PMID:11990976

  17. A randomized, within-patient, cross-over, placebo-controlled trial on the efficacy and tolerability of the tricyclic antidepressants chlorimipramine and nortriptyline in central pain.

    PubMed

    Panerai, A E; Monza, G; Movilia, P; Bianchi, M; Francucci, B M; Tiengo, M

    1990-07-01

    Antidepressant drugs are increasingly used in the management of chronic pain. They are mainly prescribed for cancer-related pain and central pain, e.g. phantom or stump pain, post-herpetic neuropathy. However, no controlled clinical trials have validated their in either pathology. Thus, physicians still do not know whether antidepressants are really effective and which might be best. It is still debated whether the effect of antidepressants in the management of chronic pain is limited to the amelioration of frequently concomitant depression or extends to pain itself. To verify both the analgesic effect of tricyclic antidepressants, and the possible relationship between their antidepressant effect and the relief of central pain, we carried out a randomized, within-patient (cross-over) placebo-controlled study in patients suffering from central pain. The results clearly indicate the better analgesic effect of tricyclic antidepressants over placebo (p less than 0.0001). Within the antidepressants tested, chlorimipramine, a blocker of serotonin reuptake, is significantly more effective (p less than 0.0001) than notriptyline, a blocker of noradrenaline reuptake. Finally, the antinociceptive effect is independent of the effects of the two drugs on the symptoms of depression. PMID:2239134

  18. Entrapment of adult fingers between window glass and seal entry of a motor vehicle side door: an experimental study for investigation of the force at the subjective pain threshold.

    PubMed

    Hohendorff, B; Weidermann, C; Pollinger, P; Burkhart, K J; Konerding, M A; Prommersberger, K J; Rommens, P M

    2011-07-28

    In modern motor vehicles with automatic power windows, a potential hazard exists for jam events of fingers between the window glass and seal entry. This study determined entrapment forces acting on adult fingers at the subjective maximum pain threshold during entrapment in such windows. The length and the girth of the proximal and distal interphalangeal joints of the triphalangeal fingers of the right hands of 109 participants (60 men, 49 women) were measured; the diameter was calculated from girth, which was assumed to be circular. The automatic power window system of a motor vehicle side door was changed to a mechanical system. During entrapment the force distributed across the four proximal interphalangeal joints (PIPs), and separately on the proximal interphalangeal (iPIP) and then the distal interphalangeal (iDIP) joints of the index finger was measured using a customized force sensor. The maximum bearable entrapment force was 97.2 ± 51.8 N for the PIPs, 43.4 ± 19.9 N for the iPIP, and 36.9 ± 17.8 N for the iDIP. The positive correlation between finger diameter and maximum entrapment force was significant. Particularly with regard to the risk to children's fingers, the 100 N statutory boundary value for closing force of electronic power windows should be reduced. PMID:21601859

  19. Groin pain

    MedlinePlus

    Pain - groin; Lower abdominal pain; Genital pain; Perineal pain ... Common causes of groin pain include: Pulled muscle, tendon, or ligaments in the leg: This problem often occurs in people who play sports such as ...

  20. [Neuropathic pain: experimental advances and clinical applications].

    PubMed

    Attal, N; Bouhassira, D

    2004-02-01

    Neuropathic pain is a clinical entity designating the different types of pain associated with a lesion of the nervous system including a wide range of pathological conditions from painful peripheral lesions (for example diabetic neuropathy, post-zoster pain, trauma-induced nerve injury) and central pain (particularly stroke-induced pain, spinal lesions, and multiple sclerosis). Despite this wide range of etiologies, neuropathic pain has well characterized clinical features which generally allow distinction from other types of pain: continuous often burn-like pain, paroxysmal pain (electrical discharge, knife stab), evoked pain, highly invalidating pain (allodynia, hyperalgesia), and associated dysethesia and/or paresthesia. Over the last ten Years, very little work has been published on neuropathic pain, which is now becoming a very active domain of research in neurobiology. Advances to date have not been spectacular although better tolerated agents have been recently marketed. Future progress should enable an appropriate response to the therapeutic challenge of neuropathic pain. PMID:15034477

  1. Effects of Videogame Distraction and a Virtual Reality Type Head-Mounted Display Helmet on Cold Pressor Pain in Young Elementary School-Aged Children

    PubMed Central

    Weiss, Karen E.; Law, Emily F.; Sil, Soumitri; Herbert, Linda Jones; Horn, Susan Berrin; Wohlheiter, Karen; Ackerman, Claire Sonntag

    2010-01-01

    Objective?This study examined the effects of videogame distraction and a virtual reality (VR) type head-mounted display helmet for children undergoing cold pressor pain.?Methods?Fifty children between the ages of 6 and 10 years underwent a baseline cold pressor trial followed by two cold pressor trials in which interactive videogame distraction was delivered via a VR helmet or without a VR helmet in counterbalanced order.?Results?As expected, children demonstrated significant improvements in pain threshold and pain tolerance during both distraction conditions. However, the two distraction conditions did not differ in effectiveness.?Conclusions?Using the VR helmet did not result in improved pain tolerance over and above the effects of interactive videogame distraction without VR technology. Clinical implications and possible developmental differences in elementary school-aged children's ability to use VR technology are discussed. PMID:19786489

  2. Effect of verbal persuasion on self-efficacy for pain-related diagnostic sensory testing in individuals with chronic neck pain and healthy controls – a randomized, controlled trial

    PubMed Central

    Söderlund, Anne; Sterling, Michele

    2016-01-01

    The aim of this study was to investigate the differences in cold pain threshold (CTh), pressure pain threshold (PPT), cold pain tolerance (CPTo) tests, and the level of self-efficacy when self-efficacy for diagnostic sensory testing was manipulated by verbal persuasion before a testing situation in persons with neck pain and in healthy controls. A randomized experimental design was used. Twenty-one healthy volunteers and 22 individuals with either traumatic or nontraumatic chronic neck pain were recruited to participate in the study. The intervention consisted of two experimental verbal persuasion conditions: Increase self-efficacy and Decrease self-efficacy. The PPT was measured using a pressure algometer, the CTh was measured using a thermo test system, and CPTo was measured by submerging the participant’s hand in ice water up to the elbow joint. On three occasions, the participants reported their self-efficacy level in performing the sensory tests. In the chronic neck pain group, there were no differences in pain threshold or tolerance. There was a difference in the self-efficacy level after verbal persuasion between the experimental conditions. In the healthy control group, the CThs increased following the condition that aimed to increase self-efficacy. No other differences were observed in the healthy controls. A short verbal persuasion in the form of manipulative instructions seems to have a marginal effect on the individual’s self-efficacy levels in the chronic neck pain group and a slight influence on the results of sensory testing in healthy controls. PMID:27022298

  3. Efficacy and tolerability of a hydrocodone extended-release tablet formulated with abuse-deterrence technology for the treatment of moderate-to-severe chronic pain in patients with osteoarthritis or low back pain

    PubMed Central

    Hale, Martin E; Laudadio, Charles; Yang, Ronghua; Narayana, Arvind; Malamut, Richard

    2015-01-01

    This double-blind, placebo-controlled study evaluated the efficacy and safety of hydrocodone extended release (ER) developed with abuse-deterrence technology to provide sustained pain relief and limit effects of alcohol and tablet manipulation on drug release. Eligible patients with chronic moderate-to-severe low back or osteoarthritis pain were titrated to an analgesic dose of hydrocodone ER (15–90 mg) and randomized to placebo or hydrocodone ER every 12 hours. The primary efficacy measure was change from baseline to week 12 in weekly average pain intensity (API; 0=no pain, 10=worst pain imaginable). Secondary measures included percentage of patients with >33% and >50% increases from baseline in weekly API, change from baseline in weekly worst pain intensity, supplemental opioid usage, aberrant drug-use behaviors, and adverse events. Overall, 294 patients were randomized and received ≥1 dose of placebo (n=148) or hydrocodone ER (n=146). Weekly API did not differ significantly between hydrocodone ER and placebo at week 12 (P=0.134); although, in post hoc analyses, the change in weekly API was significantly lower with hydrocodone ER when excluding the lowest dose (15 mg; least squares mean, −0.20 vs 0.40; P=0.032). Significantly more patients had >33% and >50% increase in weekly API with placebo (P<0.05), and mean weekly worst pain intensity was significantly lower with hydrocodone ER at week 12 (P=0.026). Supplemental medication usage was higher with placebo (86%) than hydrocodone ER (79%). Incidence of aberrant drug-use behaviors was low, and adverse events were similar between groups. This study did not meet the primary endpoint, although results support the effectiveness of this hydrocodone ER formulation in managing chronic low back or osteoarthritis pain. Use of the hydrocodone ER 15-mg dose, a robust placebo response, and use of supplemental analgesics, particularly in the placebo group, may have limited detection of a statistically significant treatment effect, and additional research is needed to clarify these findings. PMID:26396543

  4. Abdominal pain

    MedlinePlus

    Stomach pain; Pain - abdomen; Belly ache; Abdominal cramps; Bellyache; Stomachache ... bad abdominal pain if you have gas or stomach cramps due to viral gastroenteritis . However, life-threatening ...

  5. Experimental pain responses in children with chronic pain and in healthy children: How do they differ?

    PubMed Central

    Tsao, Jennie CI; Evans, Subhadra; Seidman, Laura C; Zeltzer, Lonnie K

    2012-01-01

    BACKGROUND: Extant research comparing laboratory pain responses of children with chronic pain with healthy controls is mixed, with some studies indicating lower pain responsivity for controls and others showing no differences. Few studies have included different pain modalities or assessment protocols. OBJECTIVES: To compare pain responses among 26 children (18 girls) with chronic pain and matched controls (mean age 14.8 years), to laboratory tasks involving thermal heat, pressure and cold pain. Responses to cold pain were assessed using two different protocols: an initial trial of unspecified duration and a second trial of specified duration. METHODS: Four trials of pressure pain and of thermal heat pain stimuli, all of unspecified duration, were administered, as well as the two cold pain trials. Heart rate and blood pressure were assessed at baseline and after completion of the pain tasks. RESULTS: Pain tolerance and pain intensity did not differ between children with chronic pain and controls for the unspecified trials. For the specified cold pressor trial, 92% of children with chronic pain completed the entire trial compared with only 61.5% of controls. Children with chronic pain exhibited a trend toward higher baseline and postsession heart rate and reported more anxiety and depression symptoms compared with control children. CONCLUSIONS: Contextual factors related to the fixed trial may have exerted a greater influence on pain tolerance in children with chronic pain relative to controls. Children with chronic pain demonstrated a tendency toward increased arousal in anticipation of and following pain induction compared with controls. PMID:22518373

  6. Quantitative sensory testing and pain-evoked cytokine reactivity: comparison of patients with sickle cell disease to healthy matched controls.

    PubMed

    Campbell, Claudia M; Carroll, C Patrick; Kiley, Kasey; Han, Dingfen; Haywood, Carlton; Lanzkron, Sophie; Swedberg, Lauren; Edwards, Robert R; Page, Gayle G; Haythornthwaite, Jennifer A

    2016-04-01

    Sickle cell disease (SCD) is an inherited blood disorder associated with significant morbidity, which includes severe episodic pain, and, often, chronic pain. Compared to healthy individuals, patients with SCD report enhanced sensitivity to thermal detection and pain thresholds and have altered inflammatory profiles, yet no studies to date have examined biomarker reactivity after laboratory-induced pain. We sought to examine this relationship in patients with SCD compared to healthy control participants. We completed quantitative sensory testing in 83 patients with SCD and sequential blood sampling in 27 of them, whom we matched (sex, age, race, body mass index, and education) to 27 healthy controls. Surprisingly, few quantitative sensory testing differences emerged between groups. Heat pain tolerance, pressure pain threshold at the trapezius, thumb, and quadriceps, and thermal temporal summation at 45°C differed between groups in the expected direction, whereas conditioned pain modulation and pain ratings to hot water hand immersion were counterintuitive, possibly because of tailoring the water temperature to a perceptual level; patients with SCD received milder temperatures. In the matched subsample, group differences and group-by-time interactions were observed in biomarkers including tumor necrosis factor alpha, interleukin-1ß, interleukin-4, and neuropeptide Y. These findings highlight the utility of laboratory pain testing methods for understanding individual differences in inflammatory cytokines. Our findings suggest amplified pain-evoked proinflammatory cytokine reactivity among patients with SCD relative to carefully matched controls. Future research is warranted to evaluate the impact of enhanced pain-related cytokine response and whether it is predictive of clinical characteristics and the frequency/severity of pain crises in patients with SCD. PMID:26713424

  7. Efficacy and Tolerability of Conventional Nimesulide Versus Beta-Cyclodextrin Nimesulide in Patients with Pain After Surgical Dental Extraction: A Multicenter, Prospective, Randomized, Double-Blind, Double-Dummy Study☆

    PubMed Central

    Bocanegra, Mildred; Seijas, Alberto; Yibirín, Maria González

    2003-01-01

    Background: Pain following extraction of an impacted third molar is widely used to assess analgesic efficacy, especially that of a single dose of a drug. The analgesic activity of conventional nimesulide (CN) has been documented in a variety of types of acute and chronic pain. Beta-cyclodextrin nimesulide (BN) is a new formulation in which nimesulide is included in a cyclodextrin molecule, which increases its solubility in water and its dilution rate, allowing extended, rapid absorption of the drug. Objective: The aim of this study was to assess the efficacy and tolerability of a single dose of BN compared with CN in patients with pain following extraction of an impacted third molar. Methods: This was a prospective, randomized, double-blind, double-dummy study conducted at 3 dentistry centers in Venezuela. The patients were randomized to 1 of 2 groups. One group received a single dose of BN (400-mg tablet, equivalent to 100 mg of nimesulide); the other group received a single dose of CN (100-mg tablet). Both groups also received a placebo. The efficacy variables were (1) pain intensity (PI), assessed on a visual analog scale (VAS) at the following times: 0, 5, 10, 15, 30, and 45 minutes and 1, 2, 4, 6, 8, 10, and 12 hours after drug administration; (2) time to first measurable difference in PI from baseline (PID) (PID ≥1 cm on the VAS; ie, the beginning of analgesic action); (3) maximum PID (max PID); (4) sum of PIDs in the 12-hour observation period; (5) pain relief (PR), as rated on a 5-point scale; (6) maximum PR; and (7) sum of the PR scores in the 12-hour observation period (ie, total PR). For the tolerability analysis, all adverse events (AEs) were to be recorded, and the investigators were to assess whether each AE was drug related. Results: Seventy-two patients were enrolled in the study. Of these, 62 patients (40 women, 22 men; mean [SD] age, 20.1 [5.9] years) were assessed; 35 were treated with BN and 27 with CN. PI reduction was more rapid and greater in the BN group. The first measurable change in PI (PID ≥1 on the VAS) was reached within 5 minutes by 39% and 15% of the patients in the BN and CN groups, respectively, and within 10 minutes by 52% and 30% of the patients in the BN and CN groups, respectively. The max PID was reached <1 hour in 32% and 15% of patients in the BN and CN groups, respectively. No AEs were reported. Conclusions: In this study population, both BN and CN were similarly effective in relieving pain after extraction of an impacted third molar, and both drugs were well tolerated. PI changes were statistically significantly more rapid and greater with BN than CN. PMID:24944376

  8. Flank pain

    MedlinePlus

    Pain - side; Side pain ... Flank pain can be a sign of a kidney problem. But, since many organs are in this area, other causes are possible. If you have flank pain and fever , chills, blood in the urine, or ...

  9. Postamputation pain: studies on mechanisms.

    PubMed

    Nikolajsen, Lone

    2012-10-01

    Amputation is followed by both painful and non-painful phantom phenomena in a large number of amputees. Non-painful phantom sensations rarely pose any clinical problem, but 60-80% of all amputees also experience painful sensations (i.e. phantom pain) located to the missing limb. The severity of phantom pain usually decreases with time, but severe pain persists in 5-10% of patients. Pain in the residual limb (i.e. stump pain) is another consequence of amputation. Both stump and phantom pain can be very difficult to treat. Treatment guidelines used for other neuropathic pain conditions are probably the best approximation, especially for the treatment of stump pain. The aim of the present doctoral thesis was to explore some of the mechanisms underlying pain after amputation. Ten studies were carried out (I-X). My PhD thesis from 1998 dealt with pain before the amputation and showed that preamputation pain increases the risk of phantom pain after amputation (I). A perioperative epidural blockade, however, did not reduce the incidence of pain or abnormal sensory phenomena after amputation (II, III). The importance of sensitization before amputation for the subsequent development of pain is supported by study IV, in which pressure pain thresholds obtained at the limb before amputation were inversely related to stump and phantom pain after 1 week. Afferent input from the periphery is likely to contribute to postamputation pain as sodium channels were upregulated in human neuromas (VI), although neuroma removal did not always alleviate phantom pain (V). Sensitization of neurons in the spinal cord also seems to be involved in pain after amputation as phantom pain was reduced by ketamine, an NMDA-receptor antagonist. Another NMDA-receptor antagonist, memantine, and gabapentin, a drug working by binding to the δ2α-subunit of voltage-gated calcium channels, had no effect on phantom pain (VII-IX). Supraspinal factors are also important for pain after amputation as catastrophizing was associated with phantom pain (X). In conclusion, the present doctoral thesis confirmed and expanded the findings by others that several mechanisms are involved in the development and maintenance of phantom pain. A better understanding of the underlying mechanisms will hopefully lead to improved treatment of pain after amputation in the future. PMID:23158899

  10. Clinical and Evoked Pain, Personality Traits, and Emotional States: Can Familial Confounding Explain the Associations?

    PubMed Central

    Dansie, Elizabeth; Succop, Annemarie; Chopko, Laura; Afari, Niloofar

    2014-01-01

    Objectives Pain is a complex phenomenon influenced by context and person-specific factors. Affective dimensions of pain involve both enduring personality traits and fleeting emotional states. We examined how personality traits and emotional states are linked with clinical and evoked pain in a twin sample. Methods 99 female twin pairs were evaluated for clinical and evoked pain using the McGill Pain Questionnaire (MPQ) and dolorimetry, and completed the 120-item International Personality Item Pool (IPIP), the Positive and Negative Affect Scale (PANAS), and ratings of stress and mood. Using a co-twin control design we examined a) the relationship of personality traits and emotional states with clinical and evoked pain, and b) whether genetics and common environment (i.e. familial factors) may account for the associations. Results Neuroticism was associated with the sensory component of the MPQ; this relationship was not confounded by familial factors. None of the emotional state measures was associated with the MPQ. PANAS Negative Affect was associated with lower evoked pressure pain threshold and tolerance; these associations were confounded by familial factors. There were no associations between IPIP traits and evoked pain. Conclusions A relationship exists between neuroticism and clinical pain that is not confounded by familial factors. There is no similar relationship between negative emotional states and clinical pain. In contrast, the relationship between negative emotional states and evoked pain is strong while the relationship with enduring personality traits is weak. The relationship between negative emotional states and evoked pain appears to be non-causal and due to familial factors. PMID:25311873

  11. Opioid-induced hyperalgesia in community-dwelling adults with chronic pain.

    PubMed

    Hooten, W Michael; Lamer, Tim J; Twyner, Channing

    2015-06-01

    The hyperalgesic effects of long-term opioid use in community-dwelling adults with chronic pain have not been widely reported. Therefore, the primary aim of this study was to determine the associations between opioid use and heat pain (HP) perception in a sample of community-dwelling adults with chronic pain. The study cohort involved 187 adults (85 opioid and 102 nonopioid) with chronic pain consecutively admitted to an outpatient interdisciplinary pain treatment program. Heat pain perception was assessed using a validated quantitative sensory test method of levels. An effect of opioid use was observed for nonstandardized (P = 0.004) and standardized (P = 0.005) values of HP 5-0.5 in which values of the opioid group were lower (more hyperalgesic) compared with those of the nonopioid group. HP 5-0.5 is a measure of the slope of the line connecting HP 0.5 (HP threshold) and HP 5 (intermediate measure of HP tolerance). In univariable (P = 0.019) and multiple variable (P = 0.003) linear regression analyses (adjusted for age, sex, body mass index, work status, pain diagnosis, pain severity, depression, and pain catastrophizing), opioid use was associated with lower (more hyperalgesic) nonstandardized values of HP 5-0.5. Similarly, in univariable (P = 0.004) and multiple variable (P = 0.011) linear regression analyses (adjusted for work status, pain diagnosis, pain severity, depression, and pain catastrophizing), opioid use was associated with lower standardized values of HP 5-0.5. In this sample of community-dwelling adults, these observations suggest that long-term opioid use was associated with hyperalgesia independent of other clinical factors known to influence HP perception. PMID:25815431

  12. Childhood adversities and laboratory pain perception

    PubMed Central

    Pieritz, Karoline; Rief, Winfried; Euteneuer, Frank

    2015-01-01

    Childhood adversity has frequently been related to a wide range of psychosomatic complaints in adulthood. The present study examined the relationship between different forms of childhood adversity and laboratory measures of pain. Heat pain tolerance and perceived heat pain intensity were measured in a community-based sample of 62 women (aged 20–64 years). Participants completed the Childhood Trauma Questionnaire (CTQ), which assesses five forms of childhood adversity: physical abuse, sexual abuse, emotional abuse, physical neglect, and emotional neglect. Somatic symptoms, depressive symptoms, and pain catastrophizing were assessed as potential mediators. Bivariate analyses indicated that emotional abuse but no other forms of childhood adversity were significantly related to decreased heat pain tolerance (r=−0.27; P<0.05). Accordingly, multiple regression analyses revealed that only emotional abuse was a significant predictor of heat pain tolerance (β=−0.62; P=0.034) when entering all CTQ subscales simultaneously. Although emotional abuse was also related to somatic symptoms, depressive symptoms, and pain catastrophizing, none of these variables mediated the relationship between childhood adversity and laboratory pain (P>0.1). No significant associations were found between any forms of childhood adversity and heat pain intensity. Our findings indicate that the severity of emotional childhood abuse is associated with decreased pain tolerance, an affective component of pain, but not with heat pain intensity, which has been described as a sensory component of pain. PMID:26316757

  13. Persistence behavior of chronic low back pain patients in an acute pain situation.

    PubMed

    Schmidt, A J; Brands, A M

    1986-01-01

    The test behavior of 24 chronic low back pain patients was compared with the behavior of 24 healthy control Ss., matched for age and sex, in an experimental, acute pain situation (cold pressor-test). Chronic low back pain patients showed poorer persistence behavior and reported more pain. Thus, elements of typical chronic low back pain behavior were also present in an acute pain situation. These findings are discussed within the framework of stimulus-generalization theory. In addition, the effect of different coping strategies on pain tolerance was reconfirmed. The chronic low back pain group and the control group did not cope differently. PMID:2942681

  14. Positive Traits Linked to Less Pain through Lower Pain Catastrophizing

    PubMed Central

    Hood, Anna; Pulvers, Kim; Carrillo, Janet; Merchant, Gina; Thomas, Marie

    2011-01-01

    The present study examined the association between positive traits, pain catastrophizing, and pain perceptions. We hypothesized that pain catastrophizing would mediate the relationship between positive traits and pain. First, participants (n = 114) completed the Trait Hope Scale, the Life Orientation Test- Revised, and the Pain Catastrophizing Scale. Participants then completed the experimental pain stimulus, a cold pressor task, by submerging their hand in a circulating water bath (0º Celsius) for as long as tolerable. Immediately following the task, participants completed the Short-Form McGill Pain Questionnaire (MPQ-SF). Pearson correlation found associations between hope and pain catastrophizing (r = −.41, p < .01) and MPQ-SF scores (r = −.20, p < .05). Optimism was significantly associated with pain catastrophizing (r = −.44, p < .01) and MPQ-SF scores (r = −.19, p < .05). Bootstrapping, a non-parametric resampling procedure, tested for mediation and supported our hypothesis that pain catastrophizing mediated the relationship between positive traits and MPQ-SF pain report. To our knowledge, this investigation is the first to establish that the protective link between positive traits and experimental pain operates through lower pain catastrophizing. PMID:22199416

  15. Tolerating Zero Tolerance?

    ERIC Educational Resources Information Center

    Moore, Brian N.

    2010-01-01

    The concept of zero tolerance dates back to the mid-1990s when New Jersey was creating laws to address nuisance crimes in communities. The main goal of these neighborhood crime policies was to have zero tolerance for petty crime such as graffiti or littering so as to keep more serious crimes from occurring. Next came the war on drugs. In federal…

  16. Clinical Interpretation of Quantitative Sensory Testing as a Measure of Pain Sensitivity in Patients With Sickle Cell Disease.

    PubMed

    Brandow, Amanda M; Panepinto, Julie A

    2016-05-01

    Patients with sickle cell disease (SCD) display significantly lower mean/median thermal and mechanical pain thresholds compared with controls. This suggests impaired pain sensitivity where stimuli produce exaggerated pain. Despite these mean/median differences, clinicians need to understand if patients meet criteria for impaired pain sensitivity. We defined thresholds for impaired cold, heat, and mechanical pain sensitivity in SCD patients. Using quantitative sensory testing (QST) we assessed cold, heat, and mechanical pain thresholds in SCD patients and African American controls aged 7 years and above. Impaired pain sensitivity was defined as: (1) cold pain threshold 1 SD above control median threshold; (2) heat pain threshold 1 SD below control median threshold; and (3) mechanical pain threshold 1 SD below control median threshold. Fifty-five SCD patients and 57 controls participated in this study. Impaired pain sensitivity thresholds were: (1) cold: 17.01°C, (2) heat: 43.91°C, and (3) mechanical: 4.42 g. Impaired cold pain sensitivity was the most common finding (63.6%), then heat (60%), and mechanical (38.2%). Impaired pain sensitivity to ≥1 testing modalities occurred in 81.8% of SCD patients. Determining impaired pain sensitivity thresholds increases clinical utility of QST. QST could be a screening tool to phenotype SCD pain, an outcome for pain interventional trials, or guide pain neurobiology investigations. PMID:26907660

  17. Chronic Pain

    MedlinePlus

    ... Enhancing Diversity Find People About NINDS NINDS Chronic Pain Information Page Synonym(s): Pain - Chronic Condensed from Pain: ... Español Additional resources from MedlinePlus What is Chronic Pain? While acute pain is a normal sensation triggered ...

  18. Cancer pain

    SciTech Connect

    Swerdlow, M.; Ventafridda, V.

    1987-01-01

    This book contains 13 chapters. Some of the chapter titles are: Importance of the Problem; Neurophysiology and Biochemistry of Pain; Assessment of Pain in Patients with Cancer; Drug Therapy; Chemotherapy and Radiotherapy for Cancer Pain; Sympton Control as it Relates to Pain Control; and Palliative Surgery in Cancer Pain Treatment.

  19. Efficacy and tolerability of lumiracoxib, a highly selective cyclo-oxygenase-2 (COX2) inhibitor, in the management of pain and osteoarthritis.

    PubMed

    Geusens, Piet; Lems, Willem

    2008-04-01

    Lumiracoxib is a COX2 inhibitor that is highly selective, is more effective than placebo on pain in osteoarthritis (OA), with similar analgesic and anti-inflammatory effects as non-selective NSAIDs and the selective COX2 inhibitor celecoxib, has a lower incidence of upper gastrointestinal (GI) side effects in patients not taking aspirin, and a similar incidence of cardiovascular (CV) side effects compared to naproxen or ibuprofen. In the context of earlier guidelines and taking into account the GI and CV safety results of the TARGET study, lumiracoxib had secured European Medicines Agency (EMEA) approval with as indication symptomatic treatment of OA as well as short-term management of acute pain associated with primary dysmenorrhea and following orthopedic or dental surgery. In the complex clinical context of efficiency and safety of selective and non-selective COX inhibitors, its prescription and use should be based on the risk and safety profile of the patient. In addition, there is further need for long-term GI and CV safety studies and general post-marketing safety on its use in daily practice. Meanwhile, at the time of submission of this manuscript, the EMEA has withdrawn lumiracoxib throughout Europe because of the risk of serious side effects affecting the liver. PMID:18728796

  20. Endogenous adenosine A3 receptor activation selectively alleviates persistent pain states

    PubMed Central

    Little, Joshua W.; Ford, Amanda; Symons-Liguori, Ashley M.; Chen, Zhoumou; Janes, Kali; Doyle, Timothy; Xie, Jennifer; Luongo, Livio; Tosh, Dillip K.; Maione, Sabatino; Bannister, Kirsty; Dickenson, Anthony H.; Vanderah, Todd W.; Porreca, Frank; Jacobson, Kenneth A.

    2015-01-01

    Chronic pain is a global burden that promotes disability and unnecessary suffering. To date, efficacious treatment of chronic pain has not been achieved. Thus, new therapeutic targets are needed. Here, we demonstrate that increasing endogenous adenosine levels through selective adenosine kinase inhibition produces powerful analgesic effects in rodent models of experimental neuropathic pain through the A3 adenosine receptor (A3AR, now known as ADORA3) signalling pathway. Similar results were obtained by the administration of a novel and highly selective A3AR agonist. These effects were prevented by blockade of spinal and supraspinal A3AR, lost in A3AR knock-out mice, and independent of opioid and endocannabinoid mechanisms. A3AR activation also relieved non-evoked spontaneous pain behaviours without promoting analgesic tolerance or inherent reward. Further examination revealed that A3AR activation reduced spinal cord pain processing by decreasing the excitability of spinal wide dynamic range neurons and producing supraspinal inhibition of spinal nociception through activation of serotonergic and noradrenergic bulbospinal circuits. Critically, engaging the A3AR mechanism did not alter nociceptive thresholds in non-neuropathy animals and therefore produced selective alleviation of persistent neuropathic pain states. These studies reveal A3AR activation by adenosine as an endogenous anti-nociceptive pathway and support the development of A3AR agonists as novel therapeutics to treat chronic pain. PMID:25414036

  1. Foetal pain?

    PubMed

    Derbyshire, Stuart W G

    2010-10-01

    The majority of commentary on foetal pain has looked at the maturation of neural pathways to decide a lower age limit for foetal pain. This approach is sensible because there must be a minimal necessary neural development that makes pain possible. Very broadly, it is generally agreed that the minimal necessary neural pathways for pain are in place by 24 weeks gestation. Arguments remain, however, as to the possibility of foetal pain before or after 24 weeks. Some argue that the foetus can feel pain earlier than 24 weeks because pain can be supported by subcortical structures. Others argue that the foetus cannot feel pain at any stage because it is maintained in a state of sedation in the womb and lacks further neural and conceptual development necessary for pain. Much of this argument rests on the definition of terms such as 'wakefulness' and 'pain'. If a behavioural and neural reaction to a noxious stimulus is considered sufficient for pain, then pain is possible from 24 weeks and probably much earlier. If a conceptual subjectivity is considered necessary for pain, however, then pain is not possible at any gestational age. Regardless of how pain is defined, it is clear that pain for conceptual beings is qualitatively different than pain for non-conceptual beings. It is therefore a mistake to draw an equivalence between foetal pain and pain in the older infant or adult. PMID:20356798

  2. Knee pain

    MedlinePlus

    Pain - knee ... Knee pain can have different causes. Being overweight puts you at greater risk for knee problems. Overusing your knee can trigger knee problems that cause pain. If you have a history of arthritis, it ...

  3. Elbow pain

    MedlinePlus

    Pain - elbow ... Elbow pain can be caused by many problems. A common cause in adults is tendinitis . This is inflammation and ... a partial dislocation ). Other common causes of elbow pain are: Bursitis -- inflammation of a fluid-filled cushion ...

  4. Ankle pain

    MedlinePlus

    Pain - ankle ... Ankle pain is often due to an ankle sprain. An ankle sprain is an injury to the ligaments, which ... the joint. In addition to ankle sprains, ankle pain can be caused by: Damage or swelling of ...

  5. Foot pain

    MedlinePlus

    Pain - foot ... Foot pain may be due to: Aging Being on your feet for long periods of time Being overweight A ... other sports activity The following can cause foot pain: Arthritis and gout : Common in the big toe, ...

  6. Wrist pain

    MedlinePlus

    Pain - wrist; Pain - carpal tunnel; Injury - wrist; Arthritis - wrist; Gout - wrist; Pseudogout - wrist ... Carpal tunnel syndrome: A common cause of wrist pain is carpal tunnel syndrome . You may feel aching, ...

  7. Heel pain

    MedlinePlus

    Pain - heel ... Heel pain is most often the result of overuse. Rarely, it may be caused by an injury. Your heel ... on the heel Conditions that may cause heel pain include: When the tendon that connects the back ...

  8. Pain Relievers

    MedlinePlus

    Pain relievers are medicines that reduce or relieve headaches, sore muscles, arthritis, or other aches and pains. There ... also have a slightly different response to a pain reliever. Over-the-counter (OTC) medicines are good for ...

  9. Prediction of pain in orthodontic patients based on preoperative pain assessment

    PubMed Central

    Zheng, Baoyu; Ren, Manman; Lin, Feiou; Yao, Linjie

    2016-01-01

    Aim To investigate whether pretreatment assessment of experimental pain can predict the level of pain after archwire placement. Methods One hundred and twenty-one general university students seeking orthodontic treatment were enrolled in this study. A cold pressor test was performed to estimate the pain tolerance of subjects before treatment. Self-reported pain intensity was calculated using a 10 cm visual analog scale during the 7 days after treatment. The relationship between pain tolerance and orthodontic pain was analyzed using Spearman’s correlation analysis. Results The maximum mean level of pain intensity occurred at 24 hours after bonding (53.31±16.13) and fell to normal levels at day 7. Spearman’s correlation analysis found a moderate positive association between preoperative pain tolerance and self-reported pain after archwire placement (P<0.01). There was no significant difference in pain intensity between male and female patients at any time point (P>0.05). Conclusion A simple and noninvasive preoperative sensory test (the cold pressor test) was useful in predicting the risk of developing unbearable pain in patients after archwire placement. Self-reported pain after archwire placement decreased as individual pain tolerance increased. PMID:27042019

  10. Depression, Pain, and Pain Behavior.

    ERIC Educational Resources Information Center

    Keefe, Francis J.; And Others

    1986-01-01

    Examined the degree to which depression predicted pain and pain behavior. The Beck Depression Inventory was administered to 207 low back pain patients. Depression and physical findings were the most important predictors of pain and pain behavior. Depression proved significant even after controlling for important demographic and medical status…

  11. Patellofemoral pain.

    PubMed

    Crossley, Kay M; Callaghan, Michael J; Linschoten, Robbart van

    2016-02-01

    Patellofemoral pain refers to pain behind or around the patella (also known as patellofemoral pain syndrome, anterior knee pain, runner's knee, and, formerly, chondromalacia patellae). Patellofemoral pain is common, accounting for 11-17% of all knee pain presentations to general practice.(1 2) While it typically occurs in physically active people aged <40 years, it also affects people of all activity levels and ages.(1 2) Patellofemoral pain can be diagnosed in the clinic, and evidence based treatments can reduce pain and improve function, allowing patients to maintain a physically active lifestyle. PMID:26834209

  12. Potential neurobiological benefits of exercise in chronic pain and posttraumatic stress disorder: Pilot study.

    PubMed

    Scioli-Salter, Erica; Forman, Daniel E; Otis, John D; Tun, Carlos; Allsup, Kelly; Marx, Christine E; Hauger, Richard L; Shipherd, Jillian C; Higgins, Diana; Tyzik, Anna; Rasmusson, Ann M

    2016-01-01

    This pilot study assessed the effects of cardiopulmonary exercise testing and cardiorespiratory fitness on plasma neuropeptide Y (NPY), allopregnanolone and pregnanolone (ALLO), cortisol, and dehydroepiandrosterone (DHEA), and their association with pain sensitivity. Medication-free trauma-exposed participants were either healthy (n = 7) or experiencing comorbid chronic pain/posttraumatic stress disorder (PTSD) (n = 5). Peak oxygen consumption (VO2) during exercise testing was used to characterize cardiorespiratory fitness. Peak VO2 correlated with baseline and peak NPY levels (r = 0.66, p < 0.05 and r = 0.69, p < 0.05, respectively), as well as exercise-induced changes in ALLO (r = 0.89, p < 0.001) and peak ALLO levels (r = 0.71, p < 0.01). NPY levels at the peak of exercise correlated with pain threshold 30 min after exercise (r = 0.65, p < 0.05), while exercise-induced increases in ALLO correlated with pain tolerance 30 min after exercise (r = 0.64, p < 0.05). In contrast, exercise-induced changes in cortisol and DHEA levels were inversely correlated with pain tolerance after exercise (r = -0.69, p < 0.05 and r = -0.58, p < 0.05, respectively). These data suggest that cardiorespiratory fitness is associated with higher plasma NPY levels and increased ALLO responses to exercise, which in turn relate to pain sensitivity. Future work will examine whether progressive exercise training increases cardiorespiratory fitness in association with increases in NPY and ALLO and reductions in pain sensitivity in chronic pain patients with PTSD. PMID:27006290

  13. Management of painful neuropathies.

    PubMed

    Brix Finnerup, Nanna; Hein Sindrup, Sren; Staehelin Jensen, Troels

    2013-01-01

    Neuropathic pain is the most common type of pain in neuropathy. In painful polyneuropathies the pain usually has a "glove and stocking" distribution. The pain may be predominantly spontaneous, e.g., with a burning, pricking, or shooting character or characterized by evoked pain such as mechanical or cold allodynia. In the clinical setting, the prevention of painful neuropathies and treatment of underlying neuropathy remains inadequate and thus symptomatic treatment of the pain and related disability needs to be offered. Most randomized, double-blind, placebo-controlled trials (RCTs) published in painful neuropathy have been conducted in patients with diabetes and to what extent a treatment which is found effective in painful diabetic polyneuropathy can be expected to relieve other conditions like chemotherapy- or HIV-induced neuropathy is unknown. Tricyclic antidepressants (TCAs), gabapentin, pregabalin, and serotonin noradrenaline reuptake inhibitors (SNRIs) are first drug choices. In patients with localized neuropathic pain, a topical lidocaine patch may also be considered. Second-line treatments are tramadol and other opioids. New types of treatment include botulinum toxin type A (BTX-A), high-dose capsaicin patches, and cannabinoids. Other types of anticonvulsant drugs such as lamotrigine, oxcarbazepine, and lacosamide have a more questionable efficacy in painful polyneuropathy but may have an effect in a subgroup of patients. Combination therapy may be considered in patients with insufficient effect from one drug. Treatment is usually a trial-and-error process and has to be individualized to the single patient, taking into account all comorbidities such as possible concomitant depression, anxiety, diseases, and drug interactions. Side-effects to antidepressants include dry mouth, nausea, constipation, orthostatic hypotension, and sedation. ECG should always be obtained prior to treatment with TCAs, which also should not be used in patients with cardiac incompensation and epilepsy. The most common side-effects of gabapentin and pregabalin are CNS-related side-effects with dizziness and somnolence. Peripheral edema, weight gain, nausea, vertigo, asthenia, dry mouth, and ataxia may also occur. Topical treatments are better tolerated due to lack of systemic side-effects but there is still limited evidence for the long-term efficacy of these drugs. With available drugs, the average pain reduction is about 20-30%, and only 20-35% of the patients will achieve at least 50% pain reduction, which stresses the need of a multidisciplinary approach to pain treatment. PMID:23931787

  14. Pelvic Pain

    MedlinePlus

    Pelvic pain occurs mostly in the lower abdomen area. The pain might be steady, or it might come and go. If the pain is severe, it might get in the way ... re a woman, you might feel a dull pain during your period. It could also happen during ...

  15. Shoulder pain

    MedlinePlus

    Pain - shoulder ... changes around the rotator cuff can cause shoulder pain. You may have pain when lifting the arm above your head or ... The most common cause of shoulder pain occurs when rotator cuff tendons ... The tendons become inflamed or damaged. This condition ...

  16. Electronic gaming as pain distraction.

    PubMed

    Jameson, Eleanor; Trevena, Judy; Swain, Nic

    2011-01-01

    The current study investigated whether active distraction reduces participants' experience of pain more than passive distraction during a cold pressor task. In the first experiment, 60 participants were asked to submerge their hand in cold (2C) water for as long as they could tolerate. They did this with no distraction, and then with active (electronic gaming system) and passive (television) distraction, in randomly assigned order. Tolerance time, pain intensity ratings and task absorption ratings were measured for each condition. A second experiment attempted to control for participants' expectations about the effects of distraction on pain. Forty participants underwent the same experimental procedure, but were given verbal suggestions about the effects of distraction by the experimenter before each distraction condition. Participants in both experiments had a significantly higher pain tolerance and reported less pain with the active distraction compared with passive or no distraction. Participants reported being more absorbed, and were significantly more willing to do the task again when they had the active distraction compared with both passive distraction and no distraction. They also had more enjoyment, less anxiety and greater reduction in pain with active distraction than with passive distraction. There was no effect of suggestion. These experiments offer further support for the use of electronic games as a method of pain control. PMID:21369538

  17. Noise thresholds for optical quantum computers.

    PubMed

    Dawson, Christopher M; Haselgrove, Henry L; Nielsen, Michael A

    2006-01-20

    In this Letter we numerically investigate the fault-tolerant threshold for optical cluster-state quantum computing. We allow both photon loss noise and depolarizing noise (as a general proxy for all local noise), and obtain a threshold region of allowed pairs of values for the two types of noise. Roughly speaking, our results show that scalable optical quantum computing is possible for photon loss probabilities <3 x 10(-3), and for depolarization probabilities <10(-4). PMID:16486553

  18. Pain assessment after intramuscular injection.

    PubMed

    Surber, C; Ldin, E; Flckiger, A; Dubach, U C; Ziegler, W H

    1994-12-01

    Several parameters (pH, osmotic pressure) influencing the local tolerance of injectable drugs have been well-documented; however, little attention has been paid to pain following an injection--a common problem in clinical practice. A pain questionnaire was used to record pain up to 24 h after a deep ventrogluteal injection. Two groups of healthy volunteers were recruited: the first group (n = 6) received 3 different cotrimoxazole preparations and placebo and the second group (n = 10) received 4 different multivitamin preparations and placebo (double-blind, cross-over). Parameters monitored during and after injection included pain localization (line drawing), pain intensity (visual-analog scale: VAS) and verbal description of pain (pain rating index: PRI). In both groups, the equality of pain (VAS, PRI) induced by the preparations was rejected in all cases (Friedman's test, p < or = 1%). The pairwise comparisons of the groups showed significant differences (p < or = 5%) between various preparations. The correlation (Spearman's rank correlation) between pain parameters VAS and PRI was high. The present investigations have shown that the pain questionnaire is a valuable tool to investigate the subjective pain symptoms during and after the injection of different preparations. PMID:7848364

  19. NGX-4010, a high-concentration capsaicin dermal patch for lasting relief of peripheral neuropathic pain.

    PubMed

    Noto, Christopher; Pappagallo, Marco; Szallasi, Arpad

    2009-07-01

    NeurogesX Inc is developing NGX-4010, a rapid-delivery dermal patch application system that contains high-concentration trans-capsaicin, for the treatment of peripheral neuropathic pain. Capsaicin evokes a lasting and reversible refractory state in primary sensory neurons involved in the generation and maintenance of neuropathic pain. NGX-4010 can be applied to the painful skin area up to a total surface area of 1120 cm2. In phase I clinical trials, NGX-4010 increased the threshold for warmth detection, reduced epidermal sensory nerve fiber density and was well tolerated. In phase II trials, NGX-4010 was effective in reducing pain in patients with post-herpetic neuralgia (PHN), HIV-associated distal sensory neuropathy (HIV-DSP) and painful diabetic neuropathy (PDN). Data from phase III trials in patients with PHN demonstrated that significantly more pain relief was achieved by NGX-4010 (30 to 32% reduction from baseline) compared with a low-concentration capsaicin active control (20 to 24% reduction); however, only one of two studies involving patients with HIV-DSP met the primary endpoint. NGX-4010 appears to have the potential to be an effective adjunctive or a stand-alone therapy for PHN, as well as potentially for HIV-DSP and PDN. NGX-4010 has been granted approval by the European Commission and an NDA has been accepted for filing by the FDA. PMID:19579176

  20. Cognitive-emotional sensitization contributes to wind-up-like pain in phantom limb pain patients.

    PubMed

    Vase, Lene; Nikolajsen, Lone; Christensen, Bente; Egsgaard, Line Lindhart; Arendt-Nielsen, Lars; Svensson, Peter; Staehelin Jensen, Troels

    2011-01-01

    Peripheral mechanisms are known to play a role in phantom pain following limb amputation, and more recently it has been suggested that central mechanisms may also be of importance. Some patients seem to have a psychological sensitivity that predisposes them to react with pain catastrophizing after amputation of a limb, and this coping style may contribute to increased facilitation, impaired modulation of nociceptive signals, or both. To investigate how pain catastrophizing, independently of anxiety and depression, may contribute to phantom limb pain and to alterations in pain processing twenty-four upper-limb amputees with various levels of phantom limb pain were included in the study. Patients' level of pain catastrophizing, anxiety and depression was assessed and they went through quantitative sensory testing (QST) of thresholds (mechanical and thermal) and wind-up-like pain (brush and pinprick). Catastrophizing accounted for 35% of the variance in phantom limb pain (p=0.001) independently of anxiety and depression. Catastrophizing was also positively associated with wind-up-like pain in non-medicated patients (p=0.015), but not to pain thresholds. These findings suggest that cognitive-emotional sensitization contributes to the altered nociceptive processing seen in phantom limb pain patients. The possible interactions between pain catastrophizing, wind-up-like pain, and peripheral input in generating and maintaining phantom limb pain are discussed. PMID:21067864

  1. Pain sensitivity and tactile spatial acuity are altered in healthy musicians as in chronic pain patients

    PubMed Central

    Zamorano, Anna M.; Riquelme, Inmaculada; Kleber, Boris; Altenmüller, Eckart; Hatem, Samar M.; Montoya, Pedro

    2015-01-01

    Extensive training of repetitive and highly skilled movements, as it occurs in professional classical musicians, may lead to changes in tactile sensitivity and corresponding cortical reorganization of somatosensory cortices. It is also known that professional musicians frequently experience musculoskeletal pain and pain-related symptoms during their careers. The present study aimed at understanding the complex interaction between chronic pain and music training with respect to somatosensory processing. For this purpose, tactile thresholds (mechanical detection, grating orientation, two-point discrimination) and subjective ratings to thermal and pressure pain stimuli were assessed in 17 professional musicians with chronic pain, 30 pain-free musicians, 20 non-musicians with chronic pain, and 18 pain-free non-musicians. We found that pain-free musicians displayed greater touch sensitivity (i.e., lower mechanical detection thresholds), lower tactile spatial acuity (i.e., higher grating orientation thresholds) and increased pain sensitivity to pressure and heat compared to pain-free non-musicians. Moreover, we also found that musicians and non-musicians with chronic pain presented lower tactile spatial acuity and increased pain sensitivity to pressure and heat compared to pain-free non-musicians. The significant increment of pain sensitivity together with decreased spatial discrimination in pain-free musicians and the similarity of results found in chronic pain patients, suggests that the extensive training of repetitive and highly skilled movements in classical musicians could be considered as a risk factor for developing chronic pain, probably due to use-dependent plastic changes elicited in somatosensory pathways. PMID:25610384

  2. Pain: history, culture and philosophy.

    PubMed

    Khan, Murad Ahmad; Raza, Fauzia; Khan, Iqbal Akhtar

    2015-01-01

    Pain, one of the universals of existence, has a long and venerable history, its origin initially attributed to godly punishment for disbelievers; and, with improved understanding, to physical and psycho-social factors. "Pain is emotion or sensation?" has been a debatable issue. Razes developed pleasure-pain theory, founded on the theories of Socrates, Plato, Aristotle and Epicurus. Descartes' Dualism shifted the centre of pain from the heart to the brain but negated the psychological contribution to its pathogenesis. Gate Control Theory, fascinated with the idea of "neurological gates", highlighted the important role of the brain in dealing with the messages received. The International Association of the Study of Pain, in 1979, coined a definition of pain which is currently in use and was last updated on 6th October 2014. Its validity has been challenged and a new definition has been suggested. Whereas the experience is personalized, immeasurable and unsharable, different cultural groups react differently to pain from relative tolerance to over-reaction. Gender and ethnic differences in the perception of pain are well proven and the effects of various religious beliefs adequately scored. Despite extensive research over centuries, understanding of pain mechanisms is still far from optimal. Untiring efforts to identify a paincentre in the brain have been futile. Had it been possible, millions of pain sufferers would have been relieved of their physical agony and mental anguish by the prick of needle. PMID:26203543

  3. Finger pain

    MedlinePlus

    Pain - finger ... Nearly everyone has had finger pain at some time. You may have: Tenderness Burning Stiffness Numbness Tingling Coldness Swelling Change in skin color Redness Many conditions, such ...

  4. Breast pain

    MedlinePlus

    Pain - breast; Mastalgia; Mastodynia; Breast tenderness ... There are many possible causes for breast pain. For example, hormone level changes from menstruation or pregnancy often cause breast tenderness. Some swelling and tenderness just before your period ...

  5. Ribcage pain

    MedlinePlus

    ... not cause the pain in someone who has pleurisy (swelling of the lining of the lungs) or ... Inflammation of cartilage near the breastbone ( costochondritis ) Osteoporosis Pleurisy (the pain is worse when breathing deeply)

  6. Chest pain

    MedlinePlus

    ... Collapse of the lung ( pneumothorax ) Pneumonia causes a sharp chest pain that often gets worse when you ... pleurisy ) can cause chest pain that usually feels sharp, and often gets worse when you take a ...

  7. Back Pain

    MedlinePlus

    ... Oh, my aching back!", you are not alone. Back pain is one of the most common medical problems, ... 10 people at some point during their lives. Back pain can range from a dull, constant ache to ...

  8. CARA Risk Assessment Thresholds

    NASA Technical Reports Server (NTRS)

    Hejduk, M. D.

    2016-01-01

    Warning remediation threshold (Red threshold): Pc level at which warnings are issued, and active remediation considered and usually executed. Analysis threshold (Green to Yellow threshold): Pc level at which analysis of event is indicated, including seeking additional information if warranted. Post-remediation threshold: Pc level to which remediation maneuvers are sized in order to achieve event remediation and obviate any need for immediate follow-up maneuvers. Maneuver screening threshold: Pc compliance level for routine maneuver screenings (more demanding than regular Red threshold due to additional maneuver uncertainty).

  9. Pain Experience and Perception in the Obese Subject Systematic Review (Revised Version).

    PubMed

    Torensma, Bart; Thomassen, Irene; van Velzen, Monique; In 't Veld, Bastiaan Alexander

    2016-03-01

    Pain is an integral part of life and has an important protective function. Pain perception has been shown to differ between subjects and changes with gender, race, and culture. In addition, it has been suggested that obesity influences pain perception and that obesity can be a risk factor for increased pain thresholds. The aim of this systematic review was to examine pain thresholds in obese subjects compared to non-obese subjects. The electronic databases of the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, and EMBASE were searched using combinations of terms for obese, pain measurement, visual analog scale, quantitative sensory testing, and pain perception. Studies without comparison as well as cross-sectional studies, case series, and case reports were excluded. The search was conducted without restrictions on language or date of publication. From a total of 1818 identified studies, seven studies fulfilled the inclusion criteria, whereby only one study tested the pain threshold difference between obese and non-obese and also before and after body weight loss surgery. Two studies showed a lower pain threshold and four studies a higher pain threshold in obese subjects compared to non-obese subjects. Two studies showed no difference in pain threshold before and after substantial body weight loss due to surgery. Weight loss after surgery was not identified as a factor for higher pain thresholds in obese subjects. In view of the heterogeneity of the studies, the variability of the subjects and differences in methodological quality, a meta-analysis could not be performed. From the available literature, there is a tendency towards higher pain thresholds in obese subjects. Neither substantial weight loss, nor gender, were factors explaining difference in threshold. Future randomized, controlled trials should explore demographic variables that could influence pain perception or pain thresholds in obese individuals, and multimodal pain testing is necessary for better understanding of the apparent differences in pain thresholds in obese individuals. PMID:26661107

  10. Face pain

    MedlinePlus

    Face pain may be dull and throbbing or an intense, stabbing discomfort in the face or forehead. It can occur in one or ... Pain that starts in the face may be caused by a nerve problem, injury, or infection. Face pain may also begin in other places in the body. ...

  11. Inverted Perceptual Judgment of Nociceptive Stimuli at Threshold Level following Inconsistent Cues

    PubMed Central

    Walter, Carmen; Dimova, Violeta; Bu, Julia; Parnham, Michael J.; Oertel, Bruno G.; Ltsch, Jrn

    2015-01-01

    Objective The perception of pain is susceptible to modulation by psychological and contextual factors. It has been shown that subjects judge noxious stimuli as more painful in a respective suggestive context, which disappears when the modifying context is resolved. However, a context in which subjects judge the painfulness of a nociceptive stimulus in exactly the opposite direction to that of the cues has never been shown so far. Methods Nociceptive stimuli (300 ms intranasal gaseous CO2) at the individual pain threshold level were applied after a visual cue announcing the stimulus as either no pain, merely a stimulus, or pain. Among the stimuli at threshold level, other CO2 stimuli that were clearly below or above pain threshold were randomly interspersed. These were announced beforehand in 12 subjects randomly with correct or incorrect cues, i.e., clearly painful or clearly non-painful stimuli were announced equally often as not painful or painful. By contrast, in a subsequent group of another 12 subjects, the stimuli were always announced correctly with respect to the evoked pain. Results The random and often incorrect announcement of stimuli clearly below or above pain threshold caused the subjects to rate the stimuli at pain-threshold level in the opposite direction of the cue, i.e., when the stimuli were announced as pain significantly more often than as non-painful and vice versa (p < 10-4). By contrast, in the absence of incongruence between announcement and perception of the far-from-threshold stimuli, stimuli at pain threshold were rated in the cued direction. Conclusions The present study revealed the induction of associations incongruent with a given message in the perception of pain. We created a context of unreliable cues whereby subjects perceived the stimulus opposite to that suggested by a prior cue, i.e., potentially nociceptive stimuli at pain threshold level that were announced as painful were judged as non-painful and vice versa. These findings are consistent with reported data on the effects of distrust on non-painful cognitive responses. PMID:26147732

  12. Sex differences in experimental measures of pain sensitivity and endogenous pain inhibition

    PubMed Central

    Bulls, Hailey W; Freeman, Emily L; Anderson, Austen JB; Robbins, Meredith T; Ness, Timothy J; Goodin, Burel R

    2015-01-01

    It has been suggested that increased pain sensitivity and disruption of endogenous pain inhibitory processes may account, at least in part, for the greater prevalence and severity of chronic pain in women compared to men. However, previous studies addressing this topic have produced mixed findings. This study examined sex differences in pain sensitivity and inhibition using quantitative sensory testing (QST), while also considering the influence of other important factors such as depressive symptoms and sleep quality. Healthy men (n=24) and women (n=24) each completed a QST battery. This battery included an ischemic pain task (IPT) that used a submaximal effort tourniquet procedure as well as a conditioned pain modulation (CPM) procedure for the assessment of endogenous pain inhibition. Prior to QST, participants completed the Center for Epidemiologic Studies Depression Scale and the Pittsburgh Sleep Quality Index. Analyses revealed significant sex differences for the ischemic pain task and the conditioned pain modulation procedure, such that women tolerated the ischemic pain for a shorter amount of time and demonstrated less pain inhibition compared with men. This remained true even when accounting for sex differences in depressive symptoms and sleep quality. The results of this study suggest that women may be more pain sensitive and possess less-efficient endogenous pain inhibitory capacity compared with men. Whether interventions that decrease pain sensitivity and enhance pain inhibition in women ultimately improve their clinical pain outcomes is an area of research that deserves additional attention in the future. PMID:26170713

  13. Threshold quantum cryptography

    SciTech Connect

    Tokunaga, Yuuki; Okamoto, Tatsuaki; Imoto, Nobuyuki

    2005-01-01

    We present the concept of threshold collaborative unitary transformation or threshold quantum cryptography, which is a kind of quantum version of threshold cryptography. Threshold quantum cryptography states that classical shared secrets are distributed to several parties and a subset of them, whose number is greater than a threshold, collaborates to compute a quantum cryptographic function, while keeping each share secretly inside each party. The shared secrets are reusable if no cheating is detected. As a concrete example of this concept, we show a distributed protocol (with threshold) of conjugate coding.

  14. 40 CFR 180.2010 - Threshold of regulation determinations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... 180.2010 Section 180.2010 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Requiring a Tolerance or an Exemption From a Tolerance § 180.2010 Threshold of regulation determinations... Center, 701 Mapes Rd., Ft. Meade, MD 20755-5350; telephone number: (410) 305-2905; e-mail...

  15. Correlation between ventral striatal catecholamine content and nociceptive thresholds in neuropathic mice

    PubMed Central

    Taylor, Anna M.W.; Murphy, Niall P.; Evans, Christopher J.; Cahill, Catherine M.

    2014-01-01

    Neuropathic pain is characterized by persistent, intractable pain following damage or dysfunction of the nervous system. Analgesics that include central, rather than purely peripheral, targets are more effective when treating neuropathic pain, highlighting the spinal and/or supraspinal mechanisms that contribute to this aberrant pain condition. The striatum represents one of the brain regions that have been implicated in pain processing. Release of dopamine in the ventral striatum is normally associated with analgesia. Clinical and human imaging studies suggest dopamine is disrupted in neuropathic pain patients, although the conclusions drawn from these studies are limited by their non-invasive imaging or pharmacological approaches. In this study, we used a C57Bl/6 mouse model of neuropathic pain to describe the changes in neurotransmitter content in the striatum and their relationship to evoked pain thresholds. Striatal dopamine content negatively correlated with mechanical thresholds in sham animals. Neuropathic pain animals had reduced dopamine content that was not correlated with mechanical thresholds. In contrast, norepinephrine content was significantly increased and correlated with mechanical thresholds in neuropathic, but not sham animals. These results describe changes in striatal signaling in neuropathic pain animals, and contribute to the literature defining the role of dopamine and norepinephrine in mediating sensory thresholds in healthy and neuropathic pain states. PMID:25052072

  16. Low back pain - chronic

    MedlinePlus

    Nonspecific back pain; Backache - chronic; Lumbar pain - chronic; Pain - back - chronic; Chronic back pain - low ... Low back pain is common. Almost everyone has back pain at some time in their life. Often, the exact cause of ...

  17. Phantom limb pain

    MedlinePlus

    ... shooting pain Achy pain Burning pain Cramping pain Phantom limb pain will lessen over time for most people. ... Elsevier; 2012:chap 44. Bang MS, Jung SH. Phantom limb pain. In: Frontera, WR, Silver JK, eds. Essentials ...

  18. [Oncologic pain].

    PubMed

    Alves Costa, Carla; Santos, Cristina; Alves, Paula; Costa, Agostinho

    2007-01-01

    Pain can be defined by several ways, but is usually describes as an unpleasant sensorial or emotional experience related to real or potential tissue damage, or described in terms of such damage. The cancer patient may experience pain related to the cancer itself, its treatment or not related at all with the oncologic disease. It has an extreme importance to the patient, as it is interpreted as a worsening of the prognosis or near death. Therefore it is extremely important a correct approach and treatment of cancer pain. Pain can be treated by pharmacologic, non-pharmacologic means and by more invasive procedures. The options for pharmacologic treatment are various, since nonopioid, opioid analgesics and co-analgesics. The authors present a review of the pharmacological treatment of cancer pain and alert to the importance of the recognition of pain as an illness and the possibility to be relieved. PMID:18183334

  19. Autoantibody pain.

    PubMed

    Goebel, Andreas

    2016-06-01

    As autoantibodies bind to target tissues, Fc-region dependent inflammation can induce pain via mediators exciting nociceptors. But recently another possibility has emerged, where autoantibody binding to nociceptors can directly cause pain, without inflammation. This is thought to occur as a result of Fab-region mediated modification of nerve transduction, transmission, or neuropeptide release. In three conditions, complex regional pain syndrome, anti-voltage gated potassium channel complex autoimmunity, and chronic fatigue syndrome, all associated with no or only little inflammation, initial laboratory-, and clinical trial-results have suggested a potential role for autoantibody-mediated mechanisms. More research assessing the pathogenic roles of autoantibodies in these and other chronic pain conditions is required. The concept of autoantibody-mediated pain offers hope for the development of novel therapies for currently intractable pains. PMID:26883460

  20. Neuropathic Pain

    PubMed Central

    Costigan, Michael; Scholz, Joachim; Woolf, Clifford J.

    2009-01-01

    Neuropathic pain is triggered by lesions to the somatosensory nervous system that alter its structure and function so that pain occurs spontaneously and responses to noxious and innocuous stimuli are pathologically amplified. The pain is an expression of maladaptive plasticity within the nociceptive system, a series of changes that constitute a neural disease state. Multiple alterations distributed widely across the nervous system contribute to complex pain phenotypes. These alterations include ectopic generation of action potentials, facilitation and disinhibition of synaptic transmission, loss of synaptic connectivity and formation of new synaptic circuits, and neuroimmune interactions. Although neural lesions are necessary, they are not sufficient to generate neuropathic pain; genetic polymorphisms, gender, and age all influence the risk of developing persistent pain. Treatment needs to move from merely suppressing symptoms to a disease-modifying strategy aimed at both preventing maladaptive plasticity and reducing intrinsic risk. PMID:19400724

  1. The role of threat expectancy in attentional bias and thermal pain perception in healthy individuals.

    PubMed

    Schoth, Daniel E; Yu, Karen; Liossi, Christina

    2014-05-01

    The influence of threat expectancy upon attentional biases for pain-related information and pain thresholds was explored in healthy participants. Participants were randomized to receive either threatening (n = 32) or nonthreatening (n = 31) information regarding an upcoming computerized task assessing cold and heat pain thresholds. Participants receiving threatening information were more worried about the pain task and, relative to those receiving nonthreatening information, showed attentional bias toward sensory-pain words. No between-group differences were found in terms of cold and heat pain thresholds. These results show that the type of information participants receive can influence their attentional processes and emotional concerns. PMID:23511382

  2. Vagal stomach afferents inhibit somatic pain perception.

    PubMed

    Sedan, Oshra; Sprecher, Elliot; Yarnitsky, David

    2005-02-01

    Vagal stimulation inhibits systemic pain perception in animals, probably via the nucleus tractus solitarius and its connections with descending nuclei in the brainstem which inhibit pain. Pain-inhibiting effects of such stimulation in humans, obtained from epileptic patients treated by vagal stimulation, are controversial. The aim of our study was to evaluate whether vagal stomach afferent activation inhibits pain perception in healthy humans. Pain thresholds, magnitude of tonic heat pain at 46 degrees C stimulation, pain temporal summation and laser pain evoked potentials were measured at the hand before and immediately after rapid drinking of 1500 ml water in 31 volunteers. We found an increase in heat pain threshold from 43.3+/-2.6 to 44.7+/-2.2 degrees C, P<0.0001, a decrease of peak pain magnitude to tonic heat from 56.3+/-26.2 to 43.7+/-25.8 (on 0-100 VAS), P<0.0001, a lowering of area under the curve during tonic noxious heat stimulus from 1962+/-984 to 1411+/-934, P<0.001. Additionally, we observed a decrease in the peak to peak evoked potential amplitude from 19.2 microV+/-1.2 to 15.6 microV+/-1.2 (P=0.005) together with a decrease in the estimation of mean laser induced pain from 52.28+/-18.00 to 48.14+/-20.18 (P=0.025). Mechanical pain thresholds and temporal summation did not change significantly. We conclude that vagal stomach afferents exert an inhibitory effect on somatic pain perception in humans. PMID:15661444

  3. Threshold Concepts in Biochemistry

    ERIC Educational Resources Information Center

    Loertscher, Jennifer

    2011-01-01

    Threshold concepts can be identified for any discipline and provide a framework for linking student learning to curricular design. Threshold concepts represent a transformed understanding of a discipline, without which the learner cannot progress and are therefore pivotal in learning in a discipline. Although threshold concepts have been…

  4. Threshold Concepts in Biochemistry

    ERIC Educational Resources Information Center

    Loertscher, Jennifer

    2011-01-01

    Threshold concepts can be identified for any discipline and provide a framework for linking student learning to curricular design. Threshold concepts represent a transformed understanding of a discipline, without which the learner cannot progress and are therefore pivotal in learning in a discipline. Although threshold concepts have been

  5. Tolerability of hypertonic injectables.

    PubMed

    Wang, Wei

    2015-07-25

    Injectable drug products are ideally developed as isotonic solutions. Often, hypertonic injectables may have to be marketed for a variety of reasons such as product solubilization and stabilization. A key concern during product formulation development is the local and systemic tolerability of hypertonic products upon injection. This report reviews and discusses the tolerability in terms of local discomfort, irritation, sensation of heat and pain, along with other observed side effects of hypertonicity in both in-vitro systems and in-vivo animal and human models. These side effects clearly depend on the degree of hypertonicity. The sensation of pain among different injection routes seems to follow this order: intramuscular>subcutaneous>intravenous or intravascular. It is recommended that the upper osmolality limit should be generally controlled under 600 mOsm/kg for drug products intended for intramuscular or subcutaneous injection. For drug products intended for intravenous or intravascular injection, the recommended upper limit should be generally controlled under 1,000 mOsm/kg for small-volume injections (≤ 100 mL) and 500 mOsm/kg for large-volume injections (>100mL). Several options are available for minimization of hypertonicity-induced pain upon product administration. PMID:26027488

  6. Pain referral and regional deep tissue hyperalgesia in experimental human hip pain models.

    PubMed

    Izumi, Masashi; Petersen, Kristian Kjær; Arendt-Nielsen, Lars; Graven-Nielsen, Thomas

    2014-04-01

    Hip disorder patients typically present with extensive pain referral and hyperalgesia. To better understand underlying mechanisms, an experimental hip pain model was established in which pain referrals and hyperalgesia could be studied under standardized conditions. In 16 healthy subjects, pain was induced by hypertonic saline injection into the gluteus medius tendon (GMT), adductor longus tendon (ALT), or gluteus medius muscle (GMM). Isotonic saline was injected contralaterally as control. Pain intensity was assessed on a visual analogue scale (VAS), and subjects mapped the pain distribution. Before, during, and after injections, passive hip joint pain provocation tests were completed, together with quantitative sensory testing as follows: pressure pain thresholds (PPTs), cuff algometry pain thresholds (cuff PPTs), cutaneous pin-prick sensitivity, and thermal pain thresholds. Hypertonic saline injected into the GMT resulted in higher VAS scores than hypertonic injections into the ALT and GMM (P<.05). Referred pain areas spread to larger parts of the leg after GMT and GMM injections compared with more regionalized pain pattern after ALT injections (P<.05). PPTs at the injection site were decreased after hypertonic saline injections into GMT and GMM compared with baseline, ALT injections, and isotonic saline. Cuff PPTs from the thigh were decreased after hypertonic saline injections into the ALT compared with baseline, GMT injections, and isotonic saline (P<.05). More subjects had positive joint pain provocation tests after hypertonic compared with isotonic saline injections (P<.05), indicating that this provocation test also assessed hyperalgesia in extra-articular soft tissues. The experimental models may open for better understanding of pain mechanisms associated with painful hip disorders. PMID:24447510

  7. Temperature and vibration thresholds in vibration syndrome.

    PubMed Central

    Ekenvall, L; Nilsson, B Y; Gustavsson, P

    1986-01-01

    In a study to investigate whether the quantitative assessment of temperature and vibration thresholds can improve the evaluation of the neurological symptoms in vibration syndrome 37 patients with neurological symptoms (paraesthesias, numbness, pain) in the hands who had worked with hand held vibrating tools and 46 healthy controls not exposed to vibration were examined. Temperature thresholds were measured on the thenar eminence and on the volar side of the second and third fingers held together. Vibration thresholds were determined on the dorsum of the hand and on the dorsal side of the second and fifth fingers proximal to the nail. The neutral zone between thresholds for warmth and cold was much wider in the patients than in the controls. Patients older than 45 had higher vibration thresholds than controls. Electroneurography was abnormal in 18 of 34 patients and a carpal tunnel syndrome was diagnosed in six subjects. This investigation is thus indicated in patients with neurological symptoms. Seven of the patients with normal electroneurographic findings had impaired temperature or vibration thresholds or both. Determination of sensory thresholds seems to add valuable information and the methods are, by contrast with electroneurography, easily adapted to the screening of exposed groups outside hospital. Our results indicate that thin myelinated and unmyelinated nerve fibres might be damaged in the vibration syndrome. Images PMID:3801334

  8. [Pain in elderly people with dementia].

    PubMed

    Chen, Yi-Heng; Lin, Li-Chan

    2008-04-01

    Aging is associated with an increased risk of cognitive impairment, such as Alzheimer's disease, vascular dementia and frontotemporal dementia. These diseases not only impair brain tissues and the nervous system, but also affect patients' verbal and non-verbal communicative ability. It is difficult, for instance, to assess pain in the cognitively impaired elderly because pain perception draws heavily on a patient's subjective interpretation and tolerance level. To seek an effective solution for pain detection in patients with dementia is therefore essential. From a systematic literature review covering the past decade, this paper presents a synopsis of the difficulty of pain assessment in the elderly with cognitive impairment, changes in the academic concept of pain, and explores factors resulting in obstacles to pain recognition. The obstacles to pain assessment derive mainly from three general factors. Firstly, classic definitions of early stage pain are inappropriate when applied to the elderly with cognitive impairment. Secondly, pain indicators are also unclear for this population. Thirdly, pain instruments and informants are ineffective in evaluating elderly patients with varying cognitive levels. To address these obstacles, a sound, multifaceted model of pain assessment for elderly patients with different severities of cognitive impairment is presented. On the basis of the above literature review, multiple methods for detecting aspects of pain in elderly people with cognitive impairment is recommended. To test the feasibility of the multidimensional model of pain assessment, further study is needed. PMID:18393211

  9. Transdermal opioids for cancer pain

    PubMed Central

    Skaer, Tracy L

    2006-01-01

    Patients with moderate to severe malignancy-related pain frequently require the use of opioid pharmacotherapy. Unfortunately, many cancer patients continue to be prescribed subtherapeutic doses of pain medications resulting in undo suffering and diminished quality of life. The choice of analgesic pharmacotherapy should be individualized and based on the intensity and etiology of pain reported by the patient. Health care providers must be able to readily quantify the relative analgesic potency when converting from one opioid to another or from one route of administration to another. Transdermal fentanyl is effective and well tolerated pharmacotherapy for the cancer pain patients. However, clinicians need to be cognizant that the U.S./U.K. manufacturer's recommendations for equilalagesic dosing of transdermal fentanyl may result in initial doses that produce subtherapeutic levels and unrelieved pain in some patients. A more aggressive dosing algorithm for transdermal fentanyl using a 2:1 (mg/day of oral morphine: mcg/hr of transdermal fentanyl) conversion ratio that considers both a review of the literature and clinical experience should help clinicians individualize cancer pain pharmacotherapy. Transdermal buprenorphine is now being prescribed in Europe and Australia for chronic and cancer pain management. Buprenorphine's mixed agonist/antagonist activity, dosage ceiling, and high affinity to the opiate receptor limits its use to those patients who do not already require large daily doses of opioids. Thus, buprenorphine may not be an appropriate medication for some patients with advanced unremitting cancer pain. PMID:16573839

  10. Heritability of Pain Catastrophizing and Associations with Experimental Pain Outcomes: A Twin Study

    PubMed Central

    Trost, Zina; Strachan, Eric; Sullivan, Michael; Vervoort, Tine; Avery, Ally R.; Afari, Niloofar

    2014-01-01

    The current study employed a twin paradigm to examine the genetic and environmental contributions to pain catastrophizing as well as the observed association between pain catastrophizing and cold pressor task (CPT) outcomes. Male and female monozygotic (n=206) and dizygotic twins (n=194) from the University of Washington Twin Registry completed a measure of pain catastrophizing and performed a CPT challenge. As expected, pain catastrophizing emerged as a significant predictor of several CPT outcomes, including cold pressor immersion tolerance, pain tolerance, and delayed pain rating. The heritability estimate for pain catastrophizing was found to be 37% with the remaining 63% of variance attributable to unique environmental influence. Additionally, the observed associations between pain catastrophizing and CPT outcomes were not found attributable to shared genetics or environmental exposure, suggesting a direct relationship between catastrophizing and experimental pain outcomes. This study is the first to examine the heritability of pain catastrophizing and potential processes by which pain catastrophizing is related to experimental pain response. PMID:25599234

  11. BUPRENORPHINE-NALXONE THERAPY IN PAIN MANAGEMENT

    PubMed Central

    Chen, Kelly Yan; Chen, Lucy; Mao, Jianren

    2014-01-01

    Buprenorphine-naloxone (bup/nal in 4:1 ratio; Suboxone®, Reckitt Benckiser Pharmaceuticals Incorporation, Richmond, VA) is approved by the Food and Drug Administration for outpatient office-based addiction treatment. In the past few years, bup/nal has been increasingly prescribed off-label for chronic pain management. The current data suggests that bup/nal may provide pain relief in chronic pain patients with opioid dependence or addiction. However, the unique pharmacological profile of bup/nal confers it to be a weak analgesic that is unlikely to provide adequate pain relief for patients without opioid dependence or addiction. Possible mechanisms of pain relief by bup/nal therapy in opioid-dependent chronic pain patients may include reversal of opioid-induced hyperalgesia as well as improvement in opioid tolerance and addiction. Additional studies are needed to assess the implication of bup/nal therapy in clinical anesthesia and perioperative pain management. PMID:24509068

  12. Neuropathic Pain

    MedlinePlus

    ... is difficult enough without the added burden of Opioid Induced Constipation (OIC). Track your pain & opioid side effects regularly and you may start to ... of pain or OIC you experience. Online Tool Opioid Induced Constipation Conversation Guide Having to live with ...

  13. Endogenous inhibition of somatic pain is impaired in girls with irritable bowel syndrome compared with healthy girls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endogenous pain inhibition is often deficient in adults with chronic pain conditions including irritable bowel syndrome (IBS). It is unclear whether deficiencies in pain inhibition are present in young children with IBS. The present study compared endogenous pain inhibition, somatic pain threshold, ...

  14. Acute psychosocial stress reduces pain modulation capabilities in healthy men.

    PubMed

    Geva, Nirit; Pruessner, Jens; Defrin, Ruth

    2014-11-01

    Anecdotes on the ability of individuals to continue to function under stressful conditions despite injuries causing excruciating pain suggest that acute stress may induce analgesia. However, studies exploring the effect of acute experimental stress on pain perception show inconsistent results, possibly due to methodological differences. Our aim was to systematically study the effect of acute stress on pain perception using static and dynamic, state-of-the-art pain measurements. Participants were 29 healthy men who underwent the measurement of heat-pain threshold, heat-pain intolerance, temporal summation of pain, and conditioned pain modulation (CPM). Testing was conducted before and during exposure to the Montreal Imaging Stress Task (MIST), inducing acute psychosocial stress. Stress levels were evaluated using perceived ratings of stress and anxiety, autonomic variables, and salivary cortisol. The MIST induced a significant stress reaction. Although pain threshold and pain intolerance were unaffected by stress, an increase in temporal summation of pain and a decrease in CPM were observed. These changes were significantly more robust among individuals with stronger reaction to stress ("high responders"), with a significant correlation between the perception of stress and the performance in the pain measurements. We conclude that acute psychosocial stress seems not to affect the sensitivity to pain, however, it significantly reduces the ability to modulate pain in a dose-response manner. Considering the diverse effects of stress in this and other studies, it appears that the type of stress and the magnitude of its appraisal determine its interactions with the pain system. PMID:25250721

  15. ENDOGENOUS ANALGESIA, DEPENDENCE, AND LATENT PAIN SENSITIZATION

    PubMed Central

    Taylor, Bradley K; Corder, Gregory

    2015-01-01

    Endogenous activation of μ-opioid receptors (MORs) provides relief from acute pain. Recent studies have established that tissue inflammation produces latent pain sensitization (LS) that is masked by spinal MOR signaling for months, even after complete recovery from injury and re-establishment of normal pain thresholds. Disruption with MOR inverse agonists reinstates pain and precipitates cellular, somatic and aversive signs of physical withdrawal; this phenomenon requires N-methyl-D-aspartate receptor-mediated activation of calcium-sensitive adenylyl cyclase type 1 (AC1). In this review, we present a new conceptual model of the transition from acute to chronic pain, based on the delicate balance between LS and endogenous analgesia that develops after painful tissue injury. First, injury activates pain pathways. Second, the spinal cord establishes MOR constitutive activity (MORCA) as it attempts to control pain. Third, over time, the body becomes dependent on MORCA, which paradoxically sensitizes pain pathways. Stress or injury escalates opposing inhibitory and excitatory influences on nociceptive processing as a pathological consequence of increased endogenous opioid tone. Pain begets MORCA begets pain vulnerability in a vicious cycle. The final result is a silent insidious state characterized by the escalation of two opposing excitatory and inhibitory influences on pain transmission: LS mediated by AC1 (which maintains accelerator), and pain inhibition mediated by MORCA (which maintains the brake). This raises the prospect that opposing homeostatic interactions between MORCA analgesia and latent NMDAR–AC1-mediated pain sensitization create a lasting vulnerability to develop chronic pain. Thus, chronic pain syndromes may result from a failure in constitutive signaling of spinal MORs and a loss of endogenous analgesic control. An overarching long-term therapeutic goal of future research is to alleviate chronic pain by either: a) facilitating endogenous opioid analgesia, thus restricting LS within a state of remission; or b) extinguishing LS altogether. PMID:25227929

  16. Spinal pain.

    PubMed

    Izzo, R; Popolizio, T; D'Aprile, P; Muto, M

    2015-05-01

    The spinal pain, and expecially the low back pain (LBP), represents the second cause for a medical consultation in primary care setting and a leading cause of disability worldwide [1]. LBP is more often idiopathic. It has as most frequent cause the internal disc disruption (IDD) and is referred to as discogenic pain. IDD refers to annular fissures, disc collapse and mechanical failure, with no significant modification of external disc shape, with or without endplates changes. IDD is described as a separate clinical entity in respect to disc herniation, segmental instability and degenerative disc desease (DDD). The radicular pain has as most frequent causes a disc herniation and a canal stenosis. Both discogenic and radicular pain also have either a mechanical and an inflammatory genesis. For to be richly innervated, facet joints can be a direct source of pain, while for their degenerative changes cause compression of nerve roots in lateral recesses and in the neural foramina. Degenerative instability is a common and often misdiagnosed cause of axial and radicular pain, being also a frequent indication for surgery. Acute pain tends to extinguish along with its cause, but the setting of complex processes of peripheral and central sensitization may influence its evolution in chronic pain, much more difficult to treat. The clinical assessment of pain source can be a challenge because of the complex anatomy and function of the spine; the advanced imaging methods are often not sufficient for a definitive diagnosis because similar findings could be present in either asymptomatic and symptomatic subjects: a clinical correlation is always mandatory and the therapy cannot rely uniquely upon any imaging abnormalities. Purpose of this review is to address the current concepts on the pathophysiology of discogenic, radicular, facet and dysfunctional pain, focusing on the role of the imaging in the diagnostic setting, to potentially address a correct approach also to minimally invasive interventional techniques. Special attention will be done to the discogenic pain, actually considered as the most frequent cause of chronic low back pain. PMID:25824642

  17. [Hindfoot pain].

    PubMed

    Damiano, Joël; Bouysset, Maurice

    2010-03-20

    The hindfoot is the part of the foot which is proximal to the midtarsal joint. The obvious causes of pain are not considered (post-traumatic etiologies, sprains and fractures but also cutaneous lesions). The main etiologies on the subject are successively exposed by following the localization of the pain. Diffuse pains (ankle arthritis tarsal osteoarthritis, algodystrophy, calcaneo-navicular synostosis but also bone diseases like stress fractures, Paget disease or tumors). Plantar talalgia (Sever's disease, plantar fasciitis and entrapment neuropathies such as (esions of the medial calcaneal nerve, of the first branch of the plantar lateral nerve, medial plantar nerve and lateral plantar nerve). Posterior pains: calcaneal tendinopathy including peritendinitis, tendinosis, retro-calcaneal bursitis and pathology of the postero-lateral talar tuberosity. Medial pains: tendinopathies of the posterior tibial tendon and tendinopathy of the flexor hallucis longus tendon and tarsal tunnel syndrome. Lateral pains: fibularis tendinopathies including split lesions of the fibularis brevis tendon, displacement of the fibularis iongus tendon, sinus tarsi syndrome and finally thickenings of capsules and ligaments and ossifications localized under the tibial malleoli. Anterior pains: antero-inferior tibio-fibular ligament, anterior tibial tendinopathy and anterior impingment syndrome. PMID:20402125

  18. The use of psychotropic drugs in other painful conditions.

    PubMed

    Beaumont, G

    1976-01-01

    Many studies have suggested that psychotropic drugs may be valuable in the managment of chronic painful conditions and of the pain due to neoplastic disease. An opiate-sparing effect has been postulated. Most of the studies are, unfortunately, uncontrolled. The question arises as to whether psychotropic drugs, in addition to allaying anxiety and depression, alter pain threshold or the appreciation of pain. PMID:67974

  19. Dyadic analysis of child and parent trait and state pain catastrophizing in the process of children's pain communication.

    PubMed

    Birnie, Kathryn A; Chambers, Christine T; Chorney, Jill; Fernandez, Conrad V; McGrath, Patrick J

    2016-04-01

    When explored separately, child and parent catastrophic thoughts about child pain show robust negative relations with child pain. The objective of this study was to conduct a dyadic analysis to elucidate intrapersonal and interpersonal influences of child and parent pain catastrophizing on aspects of pain communication, including observed behaviours and perceptions of child pain. A community sample of 171 dyads including children aged 8 to 12 years (89 girls) and parents (135 mothers) rated pain catastrophizing (trait and state versions) and child pain intensity and unpleasantness following a cold pressor task. Child pain tolerance was also assessed. Parent-child interactions during the cold pressor task were coded for parent attending, nonattending, and other talk, and child symptom complaints and other talk. Data were analyzed using the actor-partner interdependence model and hierarchical multiple regressions. Children reporting higher state pain catastrophizing had greater symptom complaints regardless of level of parent state pain catastrophizing. Children reporting low state pain catastrophizing had similar high levels of symptom complaints, but only when parents reported high state pain catastrophizing. Higher child and parent state and/or trait pain catastrophizing predicted their own ratings of higher child pain intensity and unpleasantness, with child state pain catastrophizing additionally predicting parent ratings. Higher pain tolerance was predicted by older child age and lower child state pain catastrophizing. These newly identified interpersonal effects highlight the relevance of the social context to children's pain expressions and parent perceptions of child pain. Both child and parent pain catastrophizing warrant consideration when managing child pain. PMID:26713422

  20. [Spiritual pain].

    PubMed

    Sato, Satoru

    2011-09-01

    We defined a spiritual pain as feelings of failure and regret at end-of-life, followed by hopelessness and worthlessness in patient's own life. In Japanese, spiritual pain should be assessed in patient's dignity, psycho-social factor, and prognostic stage, not only in religious context. And patient's spirituality should be supported with providing pain and symptom relief based on human relationships. "Sterbebegleitung" is a German proverb, introduced by Alfons Deeken, and seemed to be a suggestive word for such hope-recovering relationships. PMID:21950035

  1. Opioids for low back pain.

    PubMed

    Deyo, Richard A; Von Korff, Michael; Duhrkoop, David

    2015-01-01

    Back pain affects most adults, causes disability for some, and is a common reason for seeking healthcare. In the United States, opioid prescription for low back pain has increased, and opioids are now the most commonly prescribed drug class. More than half of regular opioid users report back pain. Rates of opioid prescribing in the US and Canada are two to three times higher than in most European countries. The analgesic efficacy of opioids for acute back pain is inferred from evidence in other acute pain conditions. Opioids do not seem to expedite return to work in injured workers or improve functional outcomes of acute back pain in primary care. For chronic back pain, systematic reviews find scant evidence of efficacy. Randomized controlled trials have high dropout rates, brief duration (four months or less), and highly selected patients. Opioids seem to have short term analgesic efficacy for chronic back pain, but benefits for function are less clear. The magnitude of pain relief across chronic non-cancer pain conditions is about 30%. Given the brevity of randomized controlled trials, the long term effectiveness and safety of opioids are unknown. Loss of long term efficacy could result from drug tolerance and emergence of hyperalgesia. Complications of opioid use include addiction and overdose related mortality, which have risen in parallel with prescription rates. Common short term side effects are constipation, nausea, sedation, and increased risk of falls and fractures. Longer term side effects may include depression and sexual dysfunction. Screening for high risk patients, treatment agreements, and urine testing have not reduced overall rates of opioid prescribing, misuse, or overdose. Newer strategies for reducing risks include more selective prescription of opioids and lower doses; use of prescription monitoring programs; avoidance of co-prescription with sedative hypnotics; and reformulations that make drugs more difficult to snort, smoke, or inject. PMID:25561513

  2. What a Pain! Kids and Growing Pains

    MedlinePlus

    ... Snowboarding, Skating Crushes What's a Booger? What a Pain! Kids and Growing Pains KidsHealth > For Kids > What a Pain! Kids and ... something doctors call growing pains . What Are Growing Pains? Growing pains aren't a disease. You probably ...

  3. Treatment of pain in osteoarthritis.

    PubMed

    Pavelka, K

    2000-01-01

    Clinical studies have demonstrated that osteoarthritic pain is strongly linked to disability and quality of life. Pain relief enables patients to regain their mobility and is therefore a key goal in the management of osteoarthritis (OA). Osteoarthritis pain is of multifactorial origin, and inflammatory mechanisms play only a partial role. Non-opioid analgesics are useful in the control of mild-to-moderate pain, but have limitations as regards efficacy, and may cause serious adverse reactions. Symptomatic slow-acting drugs in OA (SYSADOAs) are alternatives, but their usefulness is still unclear. For patients with moderate-to-severe pain, who do not obtain sufficient pain relief with paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) or do not tolerate them, the remaining options are opioids. Whereas the adverse reactions of most opioids may preclude the use of these drugs in OA patients, tramadol may be suitable. Tramadol has been investigated in various studies of OA pain and is indicated as an alternative to non-opioids, or as adjunctive therapy when non-opioid therapy is insufficient. However, the choice of analgesic treatment in OA must be highly individual. No guidelines can rigidly define a treatment regimen for such a condition as OA. Simple hints are given how to best use tramadol by selecting the right patients and choosing the right dosing strategy. PMID:11310479

  4. Age differences in orofacial sensory thresholds.

    PubMed

    Heft, M W; Robinson, M E

    2010-10-01

    Declines in sensory functioning with aging are evident for many of the senses. In the present study, thresholds were determined for somatosensory (warming and cooling temperature, pain, touch, and two-point discrimination) and taste stimuli in 178 healthy individuals aged 20-89 yrs. Somatosensory stimuli were applied to the upper lip (glabrous skin) and the chin (hairy skin). The sample was divided into two groups, based on a bimodal split "< 45 yrs" and "≥ 65 yrs". In all instances, there were elevations in thresholds for the older individuals. Further, males were less sensitive than females for cool at the chin site, for touch, and for sour taste. We conclude that there are elevations in sensory thresholds with age for multimodal somatosensory and gustatory senses. PMID:20651093

  5. Improving the quality of pain treatment by a tailored pain education programme for cancer patients in chronic pain.

    PubMed

    de Wit, R; van Dam, F; Loonstra, S; Zandbelt, L; van Buuren, A; van der Heijden, K; Leenhouts, G; Duivenvoorden, H; Huijer Abu-Saad, H

    2001-01-01

    Educational interventions, aiming to increase patients' knowledge and attitude regarding pain, can affect pain treatment. The purpose of this study was to evaluate the effects of a Pain Education Programme (PEP), on adequacy of pain treatment, and to describe characteristics predicting change in adequacy. The PEP consists of a multi-method approach in which patients are educated about the basic principles regarding pain, instructed how to report pain in a pain diary, how to communicate about pain, and how to contact healthcare providers. The effects of the PEP were evaluated taking into consideration the lack of well-established outcome measures to evaluate adequacy of pain treatment, the lack of long-term follow-up, and the influence of missing data.A prospective, randomized study was utilized in which 313 chronic cancer patients were followed-up until 8 weeks postdischarge. Adequacy of pain treatment was evaluated by means of the Amsterdam Pain Management Index (APMI), consisting of an integrated score of patients' Present Pain Intensity, Average Pain Intensity, and Worst Pain Intensity, corrected for patients' Tolerable Present Pain, with the analgesics used by the patient. At pretest, 60% of the patients in the hospital were treated inadequately for their pain. Postdischarge, the control group patients were significantly more inadequately treated at 2 weeks after discharge (56% vs 41%), at 4 weeks after discharge (62% vs 42%) and at 8 weeks after discharge (57% vs 51%) than the intervention group patients. While the level of inadequacy in the control groups remained relatively stable at all assessment points, a slight increase in the percentage of patients being treated inadequately was found in the intervention group patients over time. A beneficial effect of the PEP was found for patients both with and without district nursing. Variables predicting an improvement in adequacy of pain treatment consisted of the PEP, the APMI score at baseline, patients' level of physical functioning, patients' level of social functioning, the extent of adherence to pain medication, patients' pain knowledge, and the amount of analgesics used. These findings suggest that quality of pain treatment in cancer patients with chronic pain can be enhanced by educating patients about pain and improving active participation in their own pain treatment. The benefit from the PEP, however, decreases slightly over time, pointing at a need for ongoing education. PMID:11558980

  6. Chronic Pelvic Pain

    MedlinePlus

    ... Events Advocacy For Patients About ACOG Chronic Pelvic Pain Home For Patients Search FAQs Chronic Pelvic Pain ... Pain FAQ099, August 2011 PDF Format Chronic Pelvic Pain Gynecologic Problems What is chronic pelvic pain? What ...

  7. Fighting Chronic Pain

    MedlinePlus

    ... headaches, jaw pain (TMJ), earache, toothache, sore throat, sinus pain, facial numbness Muscles and Bones: Arthritis, back pain, bone pain from spread of cancer, fibromyalgia, chronic fatigue syndrome Neurologic: "Phantom limb" pain ...

  8. Chronic pain - resources

    MedlinePlus

    Pain - resources; Resources - chronic pain ... The following organizations are good resources for information on chronic pain: American Chronic Pain Association -- www.theacpa.org National Fibromyalgia and Chronic Pain Association -- www.fmcpaware.org ...

  9. Orofacial Pain

    MedlinePlus

    ... and Overal Health Oral Warning Signs Can Indicate Serious Medical Conditions Serious diseases, including diabetes, cancer, and ... Posture May Be the Cause of Jaw Pain games Home | InfoBites | Find a Dentist | Your Family's Oral ...

  10. Feeling pain

    MedlinePlus Videos and Cool Tools

    ... protective mechanism, alerting it to potential or actual damage to the body’s tissues. In the example of ... the pain receptors in the skin detect tissue damage from the bee sting. Then, the peripheral nerves ...

  11. Chronic Pain

    MedlinePlus

    ... you relax, such as meditation, tai chi, and yoga. It can also help decrease stress. Lifestyle changes ... my pain? What about alternative therapies, such as yoga, massage or acupuncture? Is it safe for me ...

  12. Joint pain

    MedlinePlus

    ... or conditions. It may be linked to arthritis , bursitis , and muscle pain . No matter what causes it, ... Autoimmune diseases such as rheumatoid arthritis and lupus Bursitis Chondromalacia patellae Crystals in the joint: gout (especially ...

  13. Neck Pain

    MedlinePlus

    ... also may be from RHEUMATOID ARTHRITIS, an inflammatory joint disease, or FIBROMYALGIA, a chronic condition affecting muscles and ... stiffness every day in your neck, hands, knees, hips or other joints? Yes Your pain may be ...

  14. Penis pain

    MedlinePlus

    Pain - penis ... Bites, either human or insect Cancer of the penis Erection that does not go away (priapism) Genital herpes Infected hair follicles Infected prosthesis of the penis Infection under the foreskin of uncircumcised men ( balanitis ) ...

  15. The imidazoline receptors and ligands in pain modulation.

    PubMed

    Bektas, Nurcan; Nemutlu, Dilara; Arslan, Rana

    2015-01-01

    Pain is an unpleasant experience and effects daily routine negatively. Although there are various drugs, many of them are not entirely successful in relieving pain, since pain modulation is a complex process involving numerous mediators and receptors. Therefore, it is a rational approach to identify the factors involved in the complex process and develop new agents that act on these pain producing mechanisms. In this respect, the involvement of the imidazoline receptors in pain modulation has drawn attention in recent years. In this review, it is aimed to focus on the imidazoline receptors and their ligands which contribute to the pain modulation. It is demonstrated that imidazoline-2 (I2) receptors are steady new drug targets for analgesics. Even if the mechanism of I2 receptor is not well known in the modulation of pain, it is known that it plays a role in tonic and chronic pain but not in acute phasic pain. Moreover, the I2 receptor ligands increase the analgesic effects of opioids in both acute and chronic pain and prevent the development of opioid tolerance. So, they are valuable for the chronic pain treatment and also therapeutic coadjuvants in the management of chronic pain with opiate drugs due to the attenuation of opioid tolerance and addiction. Thus, the use of the ligands which bind to the imidazoline receptors is an effective strategy for relieving pain. This educational forum exhibits the role of imidazoline receptors and ligands in pain process by utilizing experimental studies. PMID:26600633

  16. The imidazoline receptors and ligands in pain modulation

    PubMed Central

    Bektas, Nurcan; Nemutlu, Dilara; Arslan, Rana

    2015-01-01

    Pain is an unpleasant experience and effects daily routine negatively. Although there are various drugs, many of them are not entirely successful in relieving pain, since pain modulation is a complex process involving numerous mediators and receptors. Therefore, it is a rational approach to identify the factors involved in the complex process and develop new agents that act on these pain producing mechanisms. In this respect, the involvement of the imidazoline receptors in pain modulation has drawn attention in recent years. In this review, it is aimed to focus on the imidazoline receptors and their ligands which contribute to the pain modulation. It is demonstrated that imidazoline-2 (I2) receptors are steady new drug targets for analgesics. Even if the mechanism of I2 receptor is not well known in the modulation of pain, it is known that it plays a role in tonic and chronic pain but not in acute phasic pain. Moreover, the I2 receptor ligands increase the analgesic effects of opioids in both acute and chronic pain and prevent the development of opioid tolerance. So, they are valuable for the chronic pain treatment and also therapeutic coadjuvants in the management of chronic pain with opiate drugs due to the attenuation of opioid tolerance and addiction. Thus, the use of the ligands which bind to the imidazoline receptors is an effective strategy for relieving pain. This educational forum exhibits the role of imidazoline receptors and ligands in pain process by utilizing experimental studies. PMID:26600633

  17. Bayesian Threshold Estimation

    ERIC Educational Resources Information Center

    Gustafson, S. C.; Costello, C. S.; Like, E. C.; Pierce, S. J.; Shenoy, K. N.

    2009-01-01

    Bayesian estimation of a threshold time (hereafter simply threshold) for the receipt of impulse signals is accomplished given the following: 1) data, consisting of the number of impulses received in a time interval from zero to one and the time of the largest time impulse; 2) a model, consisting of a uniform probability density of impulse time

  18. Pausing at the Threshold

    ERIC Educational Resources Information Center

    Morgan, Patrick K.

    2015-01-01

    Since about 2003, the notion of threshold concepts--the central ideas in any field that change how learners think about other ideas--have become difficult to escape at library conferences and in general information literacy discourse. Their visibility will likely only increase because threshold concepts figure prominently in the Framework for…

  19. Bayesian Threshold Estimation

    ERIC Educational Resources Information Center

    Gustafson, S. C.; Costello, C. S.; Like, E. C.; Pierce, S. J.; Shenoy, K. N.

    2009-01-01

    Bayesian estimation of a threshold time (hereafter simply threshold) for the receipt of impulse signals is accomplished given the following: 1) data, consisting of the number of impulses received in a time interval from zero to one and the time of the largest time impulse; 2) a model, consisting of a uniform probability density of impulse time…

  20. Pain sensitivity can be assessed by self-rating: Development and validation of the Pain Sensitivity Questionnaire.

    PubMed

    Ruscheweyh, Ruth; Marziniak, Martin; Stumpenhorst, Frederike; Reinholz, Julia; Knecht, Stefan

    2009-11-01

    Experimental determination of pain sensitivity has received increasing attention because of emerging clinical applications (including prediction of postoperative pain and treatment response) and scientific implications (e.g. it has been proposed that above-average pain sensitivity is a risk factor for the development of chronic pain disorders). However, the use of experimental pain sensitivity assessment on a broad scale is hampered by its requirements on time, equipment and human resources and the fact that it is painful for the tested subject. Alternatives to experimental pain testing are currently lacking. Here we developed a self-rating instrument for the assessment of pain sensitivity, the Pain Sensitivity Questionnaire (PSQ) that is based on pain intensity ratings of daily life situations and takes 5-10min to complete. Adequate reliability of the PSQ was confirmed in 354 subjects. In a validation study comprising 47 healthy subjects, the results of comprehensive experimental pain testing, including different modalities (heat, cold, pressure, and pinprick) and different measures (pain thresholds, pain intensity ratings), were compared to the results of the PSQ. PSQ scores were significantly correlated to experimental pain intensity ratings (r = 0.56, p < 0.001) but not to pain thresholds (r = 0.03). Prediction of experimental pain intensity ratings by the PSQ was better than by pain-associated psychological factors (pain catastrophizing, depression, anxiety). This shows that the PSQ may be a simple alternative to experimental pain intensity rating procedures in healthy subjects and makes the PSQ a highly promising tool for clinical and experimental pain research. PMID:19665301

  1. The language of pain: A short study

    PubMed Central

    Rathnam, Arun; Madan, Nidhi; Madan, Neeti

    2010-01-01

    Background: Pain perception is a very controversial topic in child patients. It is affected by various factors such as fear, anxiety, previous experiences, parental factors, and pain threshold. The communication of such pain by the child to the parent is also very confusing with children having rudimentary and developing communication skills. A study to evaluate the pain perception of children and the parental understanding of the children's pain would be helpful in this scenario. The effect on behavior due to pain is also attempted in this particular study. Materials and Methods: A cross-sectional study of 100 children aged between 5-13 years accompanied by either parent was performed. Data collection was done with the help of questionnaires, which assessed the parental understanding of the child's pain. Pain perception recording was done with the Visual Analog Scale of Faces (VASOF). The behavior of the child was noted using the Frankl's behavior rating scale. Data was collated and statistical analysis was performed using the SPSS (version 10) software. Results and conclusion: The results show that parental factors such as education, work culture, influence parental understanding of pain. VASOF proves to be a reliable tool for pain perception in children. Behavior of the child shows a positive correlation to pain perception. PMID:22114404

  2. Multidimensional Neuropathic Pain Phenotypes after Spinal Cord Injury.

    PubMed

    Widerström-Noga, Eva; Felix, Elizabeth R; Adcock, James P; Escalona, Maydelis; Tibbett, Jacqueline

    2016-03-01

    Identifying clinical neuropathic pain phenotypes is a first step to better understand the underlying pain mechanisms after spinal cord injury (SCI). The primary purpose of the present study was to characterize multidimensional neuropathic pain phenotypes based on quantitative sensory testing (QST), pain intensity, and utilization of catastrophizing coping strategies. Thermal perception, thermal pain, and vibratory perception thresholds were assessed above and below the level of injury (LOI) in 101 persons with SCI and neuropathic pain, 18 persons with SCI and no neuropathic pain, and 50 able-bodied, pain-free controls. Cluster analysis of QST z-scores below the LOI, pain intensity ratings, and the Coping Strategies Questionnaire (CSQ) catastrophizing subscale scores in subjects with neuropathic pain resulted in two phenotypes: severe neuropathic pain (SNP) with greater pain intensity (7.39 ± 1.57) and thermal and vibratory sensitivity compared with the moderate neuropathic pain (MNP; 5.40 ± 1.43). A factor analysis including all CSQ subscales, the Neuropathic Pain Symptom Inventory (NPSI) total score, and thermal pain sensitivity above and below the LOI resulted in three factors: (1) adaptive pain coping including increasing activities, diverting attention, and reinterpreting pain sensations; (2) catastrophizing, neuropathic pain, and thermal sensitivity including greater NPSI total score, thermal pain sensitivity below the LOI, and catastrophizing; and (3) general pain sensitivity including greater thermal pain sensitivity above the LOI and lower catastrophizing. Our results suggest that neuropathic pain symptom severity post-SCI is significantly associated with residual spinothalamic tract function below the LOI and catastrophizing pain coping. PMID:26414803

  3. Painful Issues in Pain Prediction.

    PubMed

    Hu, Li; Iannetti, Gian Domenico

    2016-04-01

    How perception of pain emerges from neural activity is largely unknown. Identifying a neural 'pain signature' and deriving a way to predict perceived pain from brain activity would have enormous basic and clinical implications. Researchers are increasingly turning to functional brain imaging, often applying machine-learning algorithms to infer that pain perception occurred. Yet, such sophisticated analyses are fraught with interpretive difficulties. Here, we highlight some common and troublesome problems in the literature, and suggest methods to ensure researchers draw accurate conclusions from their results. Since functional brain imaging is increasingly finding practical applications with real-world consequences, it is critical to interpret brain scans accurately, because decisions based on neural data will only be as good as the science behind them. PMID:26898163

  4. Reflex receptive fields are enlarged in patients with musculoskeletal low back and neck pain.

    PubMed

    Biurrun Manresa, José A; Neziri, Alban Y; Curatolo, Michele; Arendt-Nielsen, Lars; Andersen, Ole K

    2013-08-01

    Pain hypersensitivity has been consistently detected in chronic pain conditions, but the underlying mechanisms are difficult to investigate in humans and thus poorly understood. Patients with endometriosis pain display enlarged reflex receptive fields (RRF), providing a new perspective in the identification of possible mechanisms behind hypersensitivity states in humans. The primary hypothesis of this study was that RRF are enlarged in patients with musculoskeletal pain. Secondary study end points were subjective pain thresholds and nociceptive withdrawal reflex (NWR) thresholds after single and repeated (temporal summation) electrical stimulation. Forty chronic neck pain patients, 40 chronic low back pain patients, and 24 acute low back pain patients were tested. Electrical stimuli were applied to 10 sites on the sole of the foot to quantify the RRF, defined as the area of the foot from where a reflex was evoked. For the secondary end points, electrical stimuli were applied to the cutaneous innervation area of the sural nerve. All patient groups presented enlarged RRF areas compared to pain-free volunteers (P<.001). Moreover, they also displayed lower NWR and pain thresholds to single and repeated electrical stimulation (P<.001). These results demonstrate that musculoskeletal pain conditions are characterized by enlarged RRF, lowered NWR and pain thresholds, and facilitated temporal summation, most likely caused by widespread spinal hyperexcitability. This study contributes to a better understanding of the mechanisms underlying these pain conditions, and it supports the use of the RRF and NWR as objective biomarkers for pain hypersensitivity in clinical and experimental pain research. PMID:23707309

  5. Relationship of 5-HTTLPR Polymorphism with Various Factors of Pain Processing: Subjective Experience, Motor Responsiveness and Catastrophizing

    PubMed Central

    Kunz, Miriam; Hennig, Jürgen; Karmann, Anna J.; Lautenbacher, Stefan

    2016-01-01

    Although serotonin is known to play an important role in pain processing, the relationship between the polymorphism in 5-HTTLPR and pain processing is not well understood. To examine the relationship more comprehensively, various factors of pain processing having putative associations with 5-HT functioning were studied, namely the subjective pain experience (pain threshold, rating of experimental pain), catastrophizing about pain (Pain Catastrophizing Scale = PCS) and motor responsiveness (facial expression of pain). In 60 female and 67 male participants, heat pain stimuli were applied by a contact thermode to assess pain thresholds, supra-threshold ratings and a composite score of pain-relevant facial responses. Participants also completed the PCS and were grouped based on their 5-HTTLPR genotype (bi-allelic evaluation) into a group with s-allele carriers (ss, sl) and a second group without (ll). S-allele carriers proved to have lower pain thresholds and higher PCS scores. These two positive findings were unrelated to each other. No other difference between genotype groups became significant. In all analyses, “age” and “gender” were controlled for. In s-allele carriers the subjective pain experience and the tendency to catastrophize about pain was enhanced, suggesting that the s-allele might be a risk factor for the development and maintenance of pain. This risk factor seems to act via two independent routes, namely via the sensory processes of subjective pain experiences and via the booster effects of pain catastrophizing. PMID:27043930

  6. [Visceral pain].

    PubMed

    Elsenbruch, S; Häuser, W; Jänig, W

    2015-10-01

    Chronic visceral pain is an unresolved neurobiological, medical and socioeconomic challenge. Up to 20% of the adult population suffer from chronic visceral pain and abdominal complaints constitute a prevalent symptom also in children and adolescents. Existing treatment approaches are often unsuccessful and patients typically suffer from multiple somatic and psychological symptoms. This complex situation requires integrative treatment approaches. This review summarizes current basic and clinical research on acute and chronic visceral pain with a focus on research groups in Germany. Despite significant clinical and scientific advances, a number of questions remain open calling for more funding to support research to elucidate the complex pathophysiology of chronic visceral pain and to develop and test new treatment approaches. Research support should focus on interdisciplinary concepts and methodology using expertise from multiple disciplines. The field would also benefit from a broader integration of visceral pain into teaching curricula in medicine and psychology and should aim to motivate young clinicians and scientists to strive for a career within this important and highly fascinating area. PMID:26271911

  7. Witnessing hateful people in pain modulates brain activity in regions associated with physical pain and reward

    PubMed Central

    Fox, Glenn R.; Sobhani, Mona; Aziz-Zadeh, Lisa

    2013-01-01

    How does witnessing a hateful person in pain compare to witnessing a likable person in pain? The current study compared the brain bases for how we perceive likable people in pain with those of viewing hateful people in pain. While social bonds are built through sharing the plight and pain of others in the name of empathy, viewing a hateful person in pain also has many potential ramifications. In this functional Magnetic Resonance Imaging (fMRI) study, Caucasian Jewish male participants viewed videos of (1) disliked, hateful, anti-Semitic individuals, and (2) liked, non-hateful, tolerant individuals in pain. The results showed that, compared with viewing liked people, viewing hateful people in pain elicited increased responses in regions associated with observation of physical pain (the insular cortex, the anterior cingulate cortex (ACC), and the somatosensory cortex), reward processing (the striatum), and frontal regions associated with emotion regulation. Functional connectivity analyses revealed connections between seed regions in the left ACC and right insular cortex with reward regions, the amygdala, and frontal regions associated with emotion regulation. These data indicate that regions of the brain active while viewing someone in pain may be more active in response to the danger or threat posed by witnessing the pain of a hateful individual more so than the desire to empathize with a likable person's pain. PMID:24167496

  8. Pain as a reward: changing the meaning of pain from negative to positive co-activates opioid and cannabinoid systems.

    PubMed

    Benedetti, Fabrizio; Thoen, Wilma; Blanchard, Catherine; Vighetti, Sergio; Arduino, Claudia

    2013-03-01

    Pain is a negative emotional experience that is modulated by a variety of psychological factors through different inhibitory systems. For example, endogenous opioids and cannabinoids have been found to be involved in stress and placebo analgesia. Here we show that when the meaning of the pain experience is changed from negative to positive through verbal suggestions, the opioid and cannabinoid systems are co-activated and these, in turn, increase pain tolerance. We induced ischemic arm pain in healthy volunteers, who had to tolerate the pain as long as possible. One group was informed about the aversive nature of the task, as done in any pain study. Conversely, a second group was told that the ischemia would be beneficial to the muscles, thus emphasizing the usefulness of the pain endurance task. We found that in the second group pain tolerance was significantly higher compared to the first one, and that this effect was partially blocked by the opioid antagonist naltrexone alone and by the cannabinoid antagonist rimonabant alone. However, the combined administration of naltrexone and rimonabant antagonized the increased tolerance completely. Our results indicate that a positive approach to pain reduces the global pain experience through the co-activation of the opioid and cannabinoid systems. These findings may have a profound impact on clinical practice. For example, postoperative pain, which means healing, can be perceived as less unpleasant than cancer pain, which means death. Therefore, the behavioral and/or pharmacological manipulation of the meaning of pain can represent an effective approach to pain management. PMID:23265686

  9. Efficient circular thresholding.

    PubMed

    Lai, Yu-Kun; Rosin, Paul L

    2014-03-01

    Otsu's algorithm for thresholding images is widely used, and the computational complexity of determining the threshold from the histogram is O(N) where N is the number of histogram bins. When the algorithm is adapted to circular rather than linear histograms then two thresholds are required for binary thresholding. We show that, surprisingly, it is still possible to determine the optimal threshold in O(N) time. The efficient optimal algorithm is over 300 times faster than traditional approaches for typical histograms and is thus particularly suitable for real-time applications. We further demonstrate the usefulness of circular thresholding using the adapted Otsu criterion for various applications, including analysis of optical flow data, indoor/outdoor image classification, and non-photorealistic rendering. In particular, by combining circular Otsu feature with other colour/texture features, a 96.9% correct rate is obtained for indoor/outdoor classification on the well known IITM-SCID2 data set, outperforming the state-of-the-art result by 4.3%. PMID:24464614

  10. Back pain during growth.

    PubMed

    Hasler, Carol C

    2013-01-01

    It is wrong to believe that back pain only burdens adults: the yearly incidence during growth ranges from 10-20%, continuously increasing from childhood to adolescence. Rapid growth-related muscular dysbalance and insufficiency, poor physical condition in an increasingly sedentary adolescent community or - vice versa - high level sports activities, account for the most prevalent functional pain syndromes. In contrast to adults the correlation of radiographic findings with pain is high: the younger the patient, the higher the probability to establish a rare morphologic cause such as benign or malignant tumours, congenital malformations and infections. In children younger than 5 years old, the likelihood is more than 50%. The following red flags should lower the threshold for a quick in-depth analysis of the problem: Age of the patient <5 years, acute trauma, functional limitation for daily activities, irradiating pain, loss of weight, duration >4 weeks, history of tumour, exposition to tuberculosis, night pain and fever. High level sport equals a biomechanical field test which reveals the biologic individual response of the growing spine to the sports-related forces. Symptomatic or asymptomatic inhibitory or stimulatory growth disturbances like Scheuermann disease, scoliosis or fatigue fractures represent the most frequent pathomorphologies. They usually occur at the disk-growth plate compound: intraspongious disk herniation, diminuition of anterior growth with vertebral wedging and apophyseal ring fractures often occur when the biomechanical impacts exceed the mechanical resistance of the cartilaginous endplates. Spondylolysis is a benign condition which rarely becomes symptomatic and responds well to conservative measures. Associated slippage of L5 on S1 is frequent but rarely progresses. The pubertal spinal growth spurt is the main risk factor for further slippage, whereas sports activity - even at a high level - is not. Therefore, the athlete should only be precluded from training if pain persists or in case of high grade slips. Perturbance of the sagittal profile with increase of lumbar lordosis, flattening of the thoracic spine and retroflexion of the pelvis with hamstrings contractures are strong signs for a grade IV olisthesis or spondyloptosis with subsequent lumbosacral kyphosis. Idiopathic scoliosis is not related to pain unless it is a marked (thoraco-) lumbar curve or if there is an underlying spinal cord pathology. Chronic back pain is an under recognised entity characterised by its duration (>3 months or recurrence within 3 months) and its social impacts such as isolation and absence from school or work. It represents an independent disease, uncoupled from any initial trigger. Multimodal therapeutic strategies are more successful than isolated, somatising orthopaedic treatment. Primary and secondary preventive active measures for the physically passive adolescents, regular sports medical check-up's for the young high level athletes, the awareness for the rare but potentially disastrous pathologies and the recognition of chronic pain syndromes are the cornerstones for successful treatment of back pain during growth. PMID:23299906

  11. Transplantation tolerance.

    PubMed

    Salisbury, Emma M; Game, David S; Lechler, Robert I

    2014-12-01

    Although transplantation has been a standard medical practice for decades, marked morbidity from the use of immunosuppressive drugs and poor long-term graft survival remain important limitations in the field. Since the first solid organ transplant between the Herrick twins in 1954, transplantation immunology has sought to move away from harmful, broad-spectrum immunosuppressive regimens that carry with them the long-term risk of potentially life-threatening opportunistic infections, cardiovascular disease, and malignancy, as well as graft toxicity and loss, towards tolerogenic strategies that promote long-term graft survival. Reports of "transplant tolerance" in kidney and liver allograft recipients whose immunosuppressive drugs were discontinued for medical or non-compliant reasons, together with results from experimental models of transplantation, provide the proof-of-principle that achieving tolerance in organ transplantation is fundamentally possible. However, translating the reconstitution of immune tolerance into the clinical setting is a daunting challenge fraught with the complexities of multiple interacting mechanisms overlaid on a background of variation in disease. In this article, we explore the basic science underlying mechanisms of tolerance and review the latest clinical advances in the quest for transplantation tolerance. PMID:24213880

  12. Back Pain

    MedlinePlus

    ... least 6 months. Other studies are comparing different health care approaches to the management of acute low back pain (standard care versus chiropractic, acupuncture, or massage therapy). These studies are measuring ... changes in health-related quality of life among patients suffering from ...

  13. Chest Pain

    MedlinePlus

    Having a pain in your chest can be scary. It does not always mean that you are having a heart attack. There can be many other causes, ... embolism Costochondritis - an inflammation of joints in your chest Some of these problems can be serious. Get ...

  14. Achilles Pain.

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    Five ailments which can cause pain in the achilles tendon area are: (1) muscular strain, involving the stretching or tearing of muscle or tendon fibers; (2) a contusion, inflammation or infection called tenosynovitis; (3) tendonitis, the inflammation of the tendon; (4) calcaneal bursitis, the inflammation of the bursa between the achilles tendon…

  15. Central pain: clinical and physiological characteristics.

    PubMed Central

    Bowsher, D

    1996-01-01

    OBJECTIVES--To study the clinical and pathophysiological features of central pain due to damage to the CNS. METHODS--156 patients (mostly with ischaemic strokes, some with infarct after subarachnoid haemorrhage and other cerebral conditions; one with bulbar and others with spinal pathology) with central pain have been investigated clinically and varying numbers instrumentally with respect to quantitative somatosensory perception thresholds and autonomic function. RESULTS--Pain onset was immediate in a minority; and from a week or two up to six years in > 60%. For those with supraspinal ischaemic lesions, the median age of onset was 59; dominant and non-dominant sides were equally affected. Two thirds of the patients had allodynia, including a previously undescribed movement allodynia apparently triggered from group I afferents. Most patients exhibited autonomic instability in that their pain was increased by physical and emotional stress and alleviated by relaxation; cutaneous blood flow and sweating may also be affected. Pain occurred within a larger area of differential sensory deficit. The critical deficit seems to be for thermal and pinprick sensations, which were more pronounced in areas of greatest than in areas of least pain; whereas low threshold mechanoceptive functions, if affected, did not vary between areas of greatest and least pain. Skinfold pinch (tissue damage) pain thresholds were only slightly affected in supraspinal cases, but greatly increased in patients with spinal lesions; thermal (heat) pain did not show this dissociation. CONCLUSION--The pathogenetic hypothesis which seems best to fit the findings is that there is up regulation or down regulation of receptors for transmitters, possibly mainly noradrenergic, over time. PMID:8676164

  16. Complex Regional Pain Syndrome

    MedlinePlus

    Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. ... in skin temperature, color, or texture Intense burning pain Extreme skin sensitivity Swelling and stiffness in affected ...

  17. Employees with Chronic Pain

    MedlinePlus

    ... Home | Accommodation and Compliance Series: Employees with Chronic Pain By Beth Loy, Ph.D. Preface Introduction Information ... at http://AskJAN.org/soar. Information about Chronic Pain How prevalent is chronic pain? Chronic pain has ...

  18. When Sex Is Painful

    MedlinePlus

    ... AQ FREQUENTLY ASKED QUESTIONS GYNECOLOGIC PROBLEMS FAQ020 When Sex Is Painful • How common is painful sex? • What causes pain during sex? • Where is pain during sex felt? • When should ...

  19. Back Pain During Pregnancy

    MedlinePlus

    ... Advocacy For Patients About ACOG Back Pain During Pregnancy Home For Patients Search FAQs Back Pain During ... FAQ115, January 2016 PDF Format Back Pain During Pregnancy Pregnancy What causes back pain during pregnancy? How ...

  20. What Is Chronic Pain?

    MedlinePlus

    ... ACPA Contact Us Shop FAQs The Art of Pain Management Resources Going to the ER Glossary Surveys What We Have Learned Communication Tools Videos Pain Management Programs Resource Guide to Chronic Pain Treatments Pain ...

  1. Pain in Parkinson's Disease

    MedlinePlus

    ... your pain and then help to build a pain management plan. Assessing and Managing Pain Your doctor can ... of care can lead to optimal results for pain management. Some treatment options include: medications physical therapy massage ...

  2. American Chronic Pain Association

    MedlinePlus

    ... ACPA Contact Us Shop FAQs The Art of Pain Management Resources Going to the ER Glossary Surveys What We Have Learned Communication Tools Videos Pain Management Programs Resource Guide to Chronic Pain Treatments Pain ...

  3. Somatoform pain disorder

    MedlinePlus

    Pain disorder ... thought to be related to emotional stress. The pain was often said to be "all in their head." However, patients with somatoform pain disorder seem to experience painful sensations in a ...

  4. Salt Tolerance

    PubMed Central

    Xiong, Liming; Zhu, Jian-Kang

    2002-01-01

    Studying salt stress is an important means to the understanding of plant ion homeostasis and osmo-balance. Salt stress research also benefits agriculture because soil salinity significantly limits plant productivity on agricultural lands. Decades of physiological and molecular studies have generated a large body of literature regarding potential salt tolerance determinants. Recent advances in applying molecular genetic analysis and genomics tools in the model plant Arabidopsis thaliana are shading light on the molecular nature of salt tolerance effectors and regulatory pathways. PMID:22303210

  5. Efficacy of disintegrating aspirin in two different models for acute mild-to-moderate pain: sore throat pain and dental pain.

    PubMed

    M, Voelker; Bp, Schachtel; Sa, Cooper; Sc, Gatoulis

    2016-02-01

    A recently developed fast-release aspirin tablet formulation has been evaluated in two different pain models. The dental impaction pain model and the sore throat pain model are widely used for assessing analgesia, including acute mild-to-moderate pain. Both studies were double-blind, randomized, parallel group and compared a single dose of 1000 mg aspirin with 1000 mg paracetamol and with placebo and investigated the onset and overall time course of pain relief. Speed of onset was measured by the double-stopwatch method for time to meaningful pain relief and time to first perceptible pain relief. Pain intensity and pain relief were rated subjectively over a 6-h (dental pain) and 2-h (sore throat pain) time period. In both models fast-release aspirin and commercial paracetamol were statistically significantly different from placebo for onset of action, summed pain intensity differences and total pain relief. Meaningful pain relief was achieved within a median of 42.3 and 42.9 min for aspirin and paracetamol, respectively, in the dental pain model. The corresponding numbers in sore throat pain were 48.0 and 40.4 min. All treatments in both studies were safe and well tolerated. No serious adverse events were reported and no subject was discontinued due to an adverse event. Overall the two studies clearly demonstrated efficacy over placebo in the two pain models and a comparable efficacy and safety profile between aspirin and an equivalent dose of paracetamol under the conditions of acute dental pain and acute sore throat pain. Trial registration These trials were registered with ClinicalTrials.gov, registration number: NCT01420094, registration date: July 27, 2011 and registration number: NCT01453400, registration date: October 13, 2011. PMID:26603742

  6. Pressure-induced referred pain is expanded by persistent soreness.

    PubMed

    Doménech-García, V; Palsson, T S; Herrero, P; Graven-Nielsen, T

    2016-05-01

    Several chronic pain conditions are accompanied with enlarged referred pain areas. This study investigated a novel method for assessing referred pain. In 20 healthy subjects, pressure pain thresholds (PPTs) were recorded and pressure stimuli (120% PPT) were applied bilaterally for 5 and 60 seconds at the infraspinatus muscle to induce local and referred pain. Moreover, PPTs were measured bilaterally at the shoulder, neck, and leg before, during, and after hypertonic saline-induced referred pain in the dominant infraspinatus muscle. The pressure and saline-induced pain areas were assessed on drawings. Subsequently, delayed onset muscle soreness was induced using eccentric exercise of the dominant infraspinatus muscle. The day-1 assessments were repeated the following day (day 2). Suprathreshold pressure stimulations and saline injections into the infraspinatus muscle caused referred pain to the frontal aspect of the shoulder/arm in all subjects. The 60-second pressure stimulation caused larger referred pain areas compared with the 5-second stimulation (P < 0.01). Compared with pressure stimulation, the saline-induced referred pain area was larger (P < 0.02). After saline-induced pain, the PPTs at the infraspinatus and supraspinatus muscles were reduced (P < 0.05), and the 5-second pressure-induced referred pain area was larger than baseline. Pressure pain thresholds at the infraspinatus and supraspinatus muscles were reduced at day 2 in the delayed onset muscle soreness side (P < 0.05). Compared with day 1, larger pressure and saline-induced referred pain areas were observed on day 2 (P < 0.05). Referred pain to the shoulder/arm was consistently induced and enlarged after 1 day of muscle soreness, indicating that the referred pain area may be a sensitive biomarker for sensitization of the pain system. PMID:26808146

  7. Mitochondrial threshold effects.

    PubMed Central

    Rossignol, Rodrigue; Faustin, Benjamin; Rocher, Christophe; Malgat, Monique; Mazat, Jean-Pierre; Letellier, Thierry

    2003-01-01

    The study of mitochondrial diseases has revealed dramatic variability in the phenotypic presentation of mitochondrial genetic defects. To attempt to understand this variability, different authors have studied energy metabolism in transmitochondrial cell lines carrying different proportions of various pathogenic mutations in their mitochondrial DNA. The same kinds of experiments have been performed on isolated mitochondria and on tissue biopsies taken from patients with mitochondrial diseases. The results have shown that, in most cases, phenotypic manifestation of the genetic defect occurs only when a threshold level is exceeded, and this phenomenon has been named the 'phenotypic threshold effect'. Subsequently, several authors showed that it was possible to inhibit considerably the activity of a respiratory chain complex, up to a critical value, without affecting the rate of mitochondrial respiration or ATP synthesis. This phenomenon was called the 'biochemical threshold effect'. More recently, quantitative analysis of the effects of various mutations in mitochondrial DNA on the rate of mitochondrial protein synthesis has revealed the existence of a 'translational threshold effect'. In this review these different mitochondrial threshold effects are discussed, along with their molecular bases and the roles that they play in the presentation of mitochondrial diseases. PMID:12467494

  8. MDL-28170 has no analgesic effect on CCI induced neuropathic pain in mice.

    PubMed

    Uçeyler, Nurcan; Biko, Lydia; Sommer, Claudia

    2010-05-01

    The calpain inhibitor MDL-28710 blocks the early local pro-inflammatory cytokine gene expression in mice after chronic constriction nerve injury (CCI). One-hundred-thirteen wild type mice of C57Bl/6J background received CCI of the right sciatic nerve. Mechanical paw withdrawal thresholds and thermal withdrawal latencies were investigated at baseline and at 1, 3, and 7 days after CCI. Three application regimens were used for MDL-28170: a) single injection 40 min before CCI; b) serial injections of MDL-28170 40 min before and up to day three after CCI; c) sustained application via intraperitoneal osmotic pumps. The control animals received the vehicle DMSO/PEG 400. The tolerable dose of MDL-28170 for mice was 30 mg/kg body weight, higher doses were lethal within the first hours after application. Mechanical withdrawal thresholds and thermal withdrawal latencies were reduced after CCI and did not normalize after single or serial injections, nor with application of MDL-28170 via osmotic pumps. Although the calpain inhibitor MDL-28170 inhibits the early local cytokine upregulation in the sciatic nerve after CCI, pain behavior is not altered. This finding implies that local cytokine upregulation after nerve injury alone is only one factor in the induction and maintenance of neuropathic pain. PMID:20657463

  9. Bogus visual feedback alters onset of movement-evoked pain in people with neck pain.

    PubMed

    Harvie, Daniel S; Broecker, Markus; Smith, Ross T; Meulders, Ann; Madden, Victoria J; Moseley, G Lorimer

    2015-04-01

    Pain is a protective perceptual response shaped by contextual, psychological, and sensory inputs that suggest danger to the body. Sensory cues suggesting that a body part is moving toward a painful position may credibly signal the threat and thereby modulate pain. In this experiment, we used virtual reality to investigate whether manipulating visual proprioceptive cues could alter movement-evoked pain in 24 people with neck pain. We hypothesized that pain would occur at a lesser degree of head rotation when visual feedback overstated true rotation and at a greater degree of rotation when visual feedback understated true rotation. Our hypothesis was clearly supported: When vision overstated the amount of rotation, pain occurred at 7% less rotation than under conditions of accurate visual feedback, and when vision understated rotation, pain occurred at 6% greater rotation than under conditions of accurate visual feedback. We concluded that visual-proprioceptive information modulated the threshold for movement-evoked pain, which suggests that stimuli that become associated with pain can themselves trigger pain. PMID:25691362

  10. Pain Sensitivity and Observer Perception of Pain in Individuals with Autistic Spectrum Disorder

    PubMed Central

    Allely, C. S.

    2013-01-01

    The peer-reviewed literature investigating the relationship between pain expression and perception of pain in individuals with ASD is sparse. The aim of the present systematic PRIMSA review was twofold: first, to see what evidence there is for the widely held belief that individuals with ASD are insensitive to pain or have a high pain threshold in the peer-reviewed literature and, second, to examine whether individuals with ASD react or express pain differently. Fifteen studies investigating pain in individuals with ASD were identified. The case studies all reported pain insensitivity in individuals with ASD. However, the majority of the ten experimental studies reviewed indicate that the idea that individuals with ASD are pain insensitive needs to be challenged. The findings also highlight the strong possibility that not all children with ASD express their physical discomfort in the same way as a neurotypical child would (i.e., cry, moan, seek comfort, etc.) which may lead caregivers and the medical profession to interpret this as pain insensitivity or incorrectly lead them to believe that the child is in no pain. These results have important implications for the assessment and management of pain in children with ASD. PMID:23843740

  11. A Prospective Cohort Study Evaluating the Ability of Anticipated Pain, Perceived Analgesic Needs, and Psychological Traits to Predict Pain and Analgesic Usage following Cesarean Delivery

    PubMed Central

    Carvalho, Brendan; Zheng, Ming; Harter, Scott; Sultan, Pervez

    2016-01-01

    Introduction. This study aimed to determine if preoperative psychological tests combined with simple pain prediction ratings could predict pain intensity and analgesic usage following cesarean delivery (CD). Methods. 50 healthy women undergoing scheduled CD with spinal anesthesia comprised the prospective study cohort. Preoperative predictors included 4 validated psychological questionnaires (Anxiety Sensitivity Index (ASI), Fear of Pain (FPQ), Pain Catastrophizing Scale, and Eysenck Personality Questionnaire) and 3 simple ratings: expected postoperative pain (0–10), anticipated analgesic threshold (0–10), and perceived analgesic needs (0–10). Postoperative outcome measures included post-CD pain (combined rest and movement) and opioid used for the 48-hour study period. Results. Bivariate correlations were significant with expected pain and opioid usage (r = 0.349), anticipated analgesic threshold and post-CD pain (r = −0.349), and perceived analgesic needs and post-CD pain (r = 0.313). Multiple linear regression analysis found that expected postoperative pain and anticipated analgesic needs contributed to post-CD pain prediction modeling (R2 = 0.443, p < 0.0001); expected postoperative pain, ASI, and FPQ were associated with opioid usage (R2 = 0.421, p < 0.0001). Conclusion. Preoperative psychological tests combined with simple pain prediction ratings accounted for 44% and 42% of pain and analgesic use variance, respectively. Preoperatively determined expected postoperative pain and perceived analgesic needs appear to be useful predictors for post-CD pain and analgesic requirements. PMID:27143966

  12. Managing Opioid-Tolerant Patients in the Perioperative Surgical Home.

    PubMed

    Wenzel, John T; Schwenk, Eric S; Baratta, Jaime L; Viscusi, Eugene R

    2016-06-01

    Management of acute postoperative pain is important to decrease perioperative morbidity and improve patient satisfaction. Opioids are associated with potential adverse events that may lead to significant risk. Uncontrolled pain is a risk factor in the transformation of acute pain to chronic pain. Balancing these issues can be especially challenging in opioid-tolerant patients undergoing surgery, for whom rapidly escalating opioid doses in an effort to control pain can be associated with increased complications. In the perioperative surgical home model, anesthesiologists are positioned to coordinate a comprehensive perioperative analgesic plan that begins with the preoperative assessment and continues through discharge. PMID:27208711

  13. Experimental Pain and Opioid Analgesia in Volunteers at High Risk for Obstructive Sleep Apnea

    PubMed Central

    Doufas, Anthony G.; Tian, Lu; Padrez, Kevin A.; Suwanprathes, Puntarica; Cardell, James A.; Maecker, Holden T.; Panousis, Periklis

    2013-01-01

    Background Obstructive sleep apnea (OSA) is characterized by recurrent nocturnal hypoxia and sleep disruption. Sleep fragmentation caused hyperalgesia in volunteers, while nocturnal hypoxemia enhanced morphine analgesic potency in children with OSA. This evidence directly relates to surgical OSA patients who are at risk for airway compromise due to postoperative use of opioids. Using accepted experimental pain models, we characterized pain processing and opioid analgesia in male volunteers recruited based on their risk for OSA. Methods After approval from the Intitutional Review Board and informed consent, we assessed heat and cold pain thresholds and tolerances in volunteers after overnight polysomnography (PSG). Three pro-inflammatory and 3 hypoxia markers were determined in the serum. Pain tests were performed at baseline, placebo, and two effect site concentrations of remifentanil (1 and 2 µg/ml), an μ-opioid agonist. Linear mixed effects regression models were employed to evaluate the association of 3 PSG descriptors [wake after sleep onset, number of sleep stage shifts, and lowest oxyhemoglobin saturation (SaO2) during sleep] and all serum markers with pain thresholds and tolerances at baseline, as well as their changes under remifentanil. Results Forty-three volunteers (12 normal and 31 with a PSG-based diagnosis of OSA) were included in the analysis. The lower nadir SaO2 and higher insulin growth factor binding protein-1 (IGFBP-1) were associated with higher analgesic sensitivity to remifentanil (SaO2, P = 0.0440; IGFBP-1, P = 0.0013). Other pro-inflammatory mediators like interleukin-1β and tumor necrosis factor-α (TNF-α) were associated with an enhanced sensitivity to the opioid analgesic effect (IL-1β, P = 0.0218; TNF-α, P = 0.0276). Conclusions Nocturnal hypoxemia in subjects at high risk for OSA was associated with an increased potency of opioid analgesia. A serum hypoxia marker (IGFBP-1) was associated with hypoalgesia and increased potency to opioid analgesia; other pro-inflammatory mediators also predicted an enhanced opioid potency. Trial Registration: ClinicalTrials.gov NCT00672737. PMID:23382975

  14. Faster magnet sorting with a threshold acceptance algorithm

    NASA Astrophysics Data System (ADS)

    Lidia, S.; Carr, R.

    1994-08-01

    The authors introduce here a new technique for sorting magnets to minimize the field errors in permanent magnet insertion devices. Simulated annealing has been used in this role, but they find the technique of threshold acceptance produces results of equal quality in less computer time. Threshold accepting would be of special value in designing very long insertion devices, such as long FEL's. Their application of threshold acceptance to magnet sorting showed that it converged to equivalently low values of the cost function, but that it converged significantly faster. They present typical cases showing time to convergence for various error tolerances, magnet numbers, and temperature schedules.

  15. Faster magnet sorting with a threshold acceptance algorithm

    NASA Astrophysics Data System (ADS)

    Lidia, Steve; Carr, Roger

    1995-02-01

    We introduce here a new technique for sorting magnets to minimize the field errors in permanent magnet insertion devices. Simulated annealing has been used in this role, but we find the technique of threshold acceptance produces results of equal quality in less computer time. Threshold accepting would be of special value in designing very long insertion devices, such as long free electron lasers (FELs). Our application of threshold acceptance to magnet sorting showed that it converged to equivalently low values of the cost function, but that it converged significantly faster. We present typical cases showing time to convergence for various error tolerances, magnet numbers, and temperature schedules.

  16. Abdominal Pain following Gastric Bypass: Suspects & Solutions

    PubMed Central

    Greenstein, Alexander J.; O’Rourke, Robert W.

    2010-01-01

    Introduction Gastric bypass remains the mainstay of surgical therapy for obesity. Abdominal pain after gastric bypass is common, and accounts for up to half of all postoperative complaints and emergency room visits. This manuscript reviews the most important causes of abdominal pain specific to gastric bypass and discusses management considerations. Data Sources The current surgical literature was reviewed using PubMed, with a focus on abdominal pain after gastric bypass and the known pathologies that underlie its pathogenesis. Conclusions The differential diagnosis for abdominal pain after gastric bypass is large and includes benign and life-threatening entities. Its diverse causes require a broad evaluation that should be directed by history and clinical presentation. In the absence of a clear diagnosis, the threshold for surgical exploration in patients with abdominal pain after gastric bypass should be low. PMID:21333269

  17. Biofeedback for pain management in traumatised refugees.

    PubMed

    Muller, Julia; Karl, Anke; Denke, Claudia; Mathier, Fabienne; Dittmann, Jennifer; Rohleder, Nicolas; Knaevelsrud, Christine

    2009-01-01

    Chronic pain (CP) and posttraumatic stress disorder (PTSD) are both frequent and often comorbid in refugees. To date, few controlled trials have studied the efficacy of treatments targeting this comorbidity; no treatment guidelines yet exist. The authors examined the feasibility and efficacy of short-term cognitive behavioural biofeedback (BF) addressing CP in traumatised refugees. The sample comprised 11 severely traumatised refugees with CP and PTSD (mean age = 36 years, SD = 6), who underwent assessment with the Mini International Neuropsychiatric Interview, Posttraumatic Diagnostic Scale, Pain Disability Index, and Visual Rating Scale. Additionally, coping with pain and psychotherapy tolerance were assessed. Acceptance of BF was high. Pre-post effects were small to medium for increased pain management and associated heart rate reactivity but large for coping with pain. The results encourage further research to confirm whether BF is indicated as a treatment component, but not a stand-alone treatment, for traumatised refugees with comorbid CP and PTSD. PMID:19675955

  18. Religious Tolerance.

    ERIC Educational Resources Information Center

    Martz, Carlton

    2000-01-01

    This theme issue looks at three issues of religious tolerance. The first article examines a case recently decided by the United States Supreme Court on student-led prayers at school events. The second article explores the persecution suffered by members of the Mormon religion during the 19th century. The final article looks at Martin Luther and…

  19. Analysis of deep tissue hypersensitivity to pressure pain in professional pianists with insidious mechanical neck pain

    PubMed Central

    2011-01-01

    Background The aim of this study was to investigate whether pressure pain hyperalgesia is a feature of professional pianists suffering from neck pain as their main playing-related musculoskeletal disorder. Methods Twenty-three active expert pianists, 6 males and 17 females (age: 36 ± 12 years) with insidious neck pain and 23 pianists, 9 males and 14 females (age: 38 ± 10 years) without neck pain the previous year were recruited. A numerical pain rate scale, Neck Disability Index, hand size and pressure pain thresholds (PPT) were assessed bilaterally over the C5-C6 zygapophyseal joint, deltoid muscle, the second metacarpal and the tibialis anterior muscle in a blinded design. Results The results showed that PPT levels were significantly decreased bilaterally over the second metacarpal and tibialis anterior muscles (P < 0.05), but not over C5-C6 zygapophyseal joint and deltoid muscle (P > 0.10), in pianists with neck pain as compared to healthy pianists. Pianists with neck pain had a smaller (P < 0.05) hand size (mean: 181.8 ± 11.8) as compared to pianists without neck pain (mean: 188. 6 ± 13.1). PPT over the tibialis anterior muscles was negatively correlated with the intensity of neck pain. Conclusions Our findings revealed pressure pain hypersensitivity over distant non-symptomatic distant points but not over the symptomatic areas in pianists suffering from neck pain. In addition, pianists with neck pain also had smaller hand size than those without neck pain. Future studies are needed to further determine the relevance of these findings in the clinical course of neck pain as playing-related musculoskeletal disorder in professional pianists. PMID:22111912

  20. [Abdominal pain].

    PubMed

    Beer, D; Bettschart, V

    2001-01-01

    The doctor on duty conducting home visits is frequently asked to care for patients with non-traumatic severe abdominal pain. For this reason, visiting doctors should be able to recognize tell-tale alarm signs, evaluate ailments that call for surgical referral to--particularly those that require emergency surgery--and, if necessary, perform simple paraclinical exams at the patient's bedside. In the case of intense abdominal pain requiring a rapid and effective "analgesia", the doctor should be able to administer an opiate, without of the surgical unit impairing the judgement. When hospitalisation or referral for surgery is not necessary, a re-evaluation at 12 to 36 hours later should be offered. PMID:11234707

  1. Neck pain

    PubMed Central

    2008-01-01

    Introduction Non-specific neck pain has a postural or mechanical basis and affects about two thirds of people at some stage, especially in middle age. Acute neck pain resolves within days or weeks, but may become chronic in about 10% of people. Whiplash injuries follow sudden acceleration–deceleration of the neck, such as in road traffic or sporting accidents. Up to 40% of people continue to report symptoms 15 years after the accident, although this varies between countries. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatments for people with non-specific neck pain without severe neurological deficit? What are the effects of treatments for acute whiplash injury? What are the effects of treatments for chronic whiplash injury? What are the effects of treatments for neck pain with radiculopathy? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2007 (BMJ Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 91 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of the evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: acupuncture, biofeedback, drug treatments (analgesics, antidepressants, epidural steroid injections, muscle relaxants, non-steroidal anti-inflammatory drugs [NSAIDs]), early mobilisation, early return to normal activity, exercise, heat or cold, manipulation (alone or plus exercise), mobilisation, multimodal treatment, patient education, percutaneous radiofrequency neurotomy, physical treatments, postural techniques (yoga, pilates, Alexander technique), pulsed electromagnetic field (PEMF) treatment, soft collars and special pillows, spray and stretch, surgery, traction, and transcutaneous electrical nerve stimulation (TENS). PMID:19445809

  2. Effects of shoulder stabilization exercise on pain and function in patients with neck pain

    PubMed Central

    Lee, Youna; Shin, Mary Myong Sook; Lee, Wanhee

    2015-01-01

    [Purpose] The objective of this study was to investigate the effects of shoulder stability exercise on pain and function in neck pain patients. [Subjects] The study design consisted of a shoulder stability exercise group and a control group. [Methods] The effects of the therapies were evaluated using a visual analog scale of pain, a pressure pain threshold, neck disability index, cervical range of motion, and a closed kinetic chain test. Each group received treatment five times per week for 4 weeks. [Results] Pain levels showed no significant differences between groups, while pain threshold in all muscles, showed significant increases for both control groups. Neck disability significantly decreased for both groups and the differences between the groups were statistically significant. Ranges of motion and limb stability were measured before and after the exercise period. Flexion, extension, and right rotation were not significantly different between groups. The results showed no significant differences in shoulder stability between the groups. [Conclusion] The use of this exercise should have pronounced effects on pain reduction and functional improvement and should also improve the quality of life in patients with neck pain. PMID:26834317

  3. Setting Graduation Rate Thresholds.

    ERIC Educational Resources Information Center

    Underwood, David G.; Rieck, James R.

    1999-01-01

    Reviews the college completion/graduation rate thresholds developed by several states and discusses advantages and disadvantages of several statistical approaches, including use of the one standard deviation lower bound method, the logit prediction bound method, the linear regression method, and the logistic regression method. (DB)

  4. Elaborating on Threshold Concepts

    ERIC Educational Resources Information Center

    Rountree, Janet; Robins, Anthony; Rountree, Nathan

    2013-01-01

    We propose an expanded definition of Threshold Concepts (TCs) that requires the successful acquisition and internalisation not only of knowledge, but also its practical elaboration in the domains of applied strategies and mental models. This richer definition allows us to clarify the relationship between TCs and Fundamental Ideas, and to account…

  5. Psoriasis and skin pain: instrumental and biological evaluations.

    PubMed

    Patruno, Cataldo; Napolitano, Maddalena; Balato, Nicola; Ayala, Fabio; Megna, Matteo; Patr, Angela; Cirillo, Teresa; Balato, Anna

    2015-04-01

    The prevalence of skin pain and the molecular mechanisms responsible for pain in psoriasis remain unclear. This study assessed skin pain in 163 patients (98 males, 65 females, range 18-81 years) with plaque psoriasis, evaluating: the subjective/objective features of this symptom compared with clinical severity of the disease; and the role of interleukin (IL)-33, (involved in both psoriasis and pain pathogenesis), in psoriasis-related pain. Clinical measures used were a questionnaire, plaque Physician Global Assessment (PGA) index, pressure algometry to measure pain threshold and tactile/thermal sensitivity test. IL-33 gene expression was examined in vivo (n = 12) in patients skin and through an ex vivo model of nociception using sodium dodecyl sulphate. Of the psoriatic patients 43.6% reported skin pain during the previous week; itchy, unpleasant, aching, sensitive, hot/burning, tender and cramping were the most reported qualities. Patients' pain threshold decreased with increasing PGA index and pain intensity. Sensitivity to touch/heat was reduced in lesional skin, compared with unaffected psoriatic skin. IL-33 expression was increased in lesional skin of patients reporting pain and in the ex vivo system. In conclusion, symptoms of skin pain should be taken into account in the management of psoriasis. PMID:25178645

  6. The overhead of fault-tolerant quantum computing

    NASA Astrophysics Data System (ADS)

    Gottesman, Daniel

    2014-03-01

    The threshold theorem for fault tolerance tells us that it is possible to build arbitrarily large reliable quantum computers provided the error rate per physical gate or time step is below some threshold value. Most research on the threshold theorem so far has gone into optimizing the tolerable error rate under various assumptions, with other considerations being secondary. However, for the foreseeable future, the number of qubits may be an even greater restriction than error rates. The overhead, the ratio of physical qubits to logical qubits, determines how expensive (in qubits) a fault-tolerant computation is. Earlier results on fault tolerance used a large overhead which grows (albeit slowly) with the size of the computation. I show that it is possible in principle to do fault-tolerant quantum computation with low overhead, and with the overhead constant in the size of the computation. The result depends on recent progress on quantum low-density parity check codes.

  7. Pediatric Pain, Predictive Inference, and Sensitivity Analysis.

    ERIC Educational Resources Information Center

    Weiss, Robert

    1994-01-01

    Coping style and effects of counseling intervention on pain tolerance was studied for 61 elementary school students through immersion of hands in cold water. Bayesian predictive inference tools are able to distinguish between subject characteristics and manipulable treatments. Sensitivity analysis strengthens the certainty of conclusions about…

  8. Pain and Hand Function.

    PubMed

    Howland, Nicholas; Lopez, Mariela; Zhang, Andrew Y

    2016-02-01

    Pain is a unique somatosensory perception that can dramatically affect our ability to function. It is also a necessary perception, without which we would do irreparable damage to ourselves. In this article, the authors assess the impact of pain on function of the hand. Pain can be categorized into acute pain, chronic pain, and neuropathic pain. Hand function and objective measurements of hand function are analyzed as well as the impact of different types of pain on each of these areas. PMID:26611383

  9. Application of Pain Quantitative Analysis Device for Assessment of Postoperative Pain after Arthroscopic Rotator Cuff Repair

    PubMed Central

    Mifune, Yutaka; Inui, Atsuyuki; Nagura, Issei; Sakata, Ryosuke; Muto, Tomoyuki; Harada, Yoshifumi; Takase, Fumiaki; Kurosaka, Masahiro; Kokubu, Takeshi

    2015-01-01

    Purpose : The PainVision™ system was recently developed for quantitative pain assessment. Here, we used this system to evaluate the effect of plexus brachialis block on postoperative pain after arthroscopic rotator cuff repair. Methods : Fifty-five patients who underwent arthroscopic rotator cuff repair were included in this study. First 26 cases received no plexus brachialis block (control group), and the next 29 cases received the plexus brachialis block before surgery (block group). Patients completed the visual analog scale at 4, 8, 16, and 24 hours after surgery, and the intensity of postoperative pain was assessed with PainVision™ at 16 hours. The postoperative use of non-steroidal anti-inflammatory agents was also recorded. Results : The pain intensity at 16 hours after surgery assessed by PainVision™ was significantly lower in the block group than in the control group (block, 252.0 ± 47.8, control, 489.0 ± 89.1, P < 0.05). However, there were no differences in the VAS values at 16 hours between the 2 groups (block, 4.3 ± 0.6, control, 5.7 ± 0.4, P = N.S.). The pain intensity and VAS at 16 hours after surgery were highly correlated (r = 0.59, P = 0.006 in the block group and r = 0.62, P = 0.003 in the control group). The effect size of the assessment by PainVision™ was bigger than that of VAS (r=0.31 in VAS and 0.51 in Pain vision). Conclusion : The PainVision™ system could be useful to evaluate postoperative pain because it enables the quantification and comparison of pain intensity independent of individual pain thresholds. PMID:26157522

  10. Fault-tolerant almost exact state transmission

    PubMed Central

    Wang, Zhao-Ming; Wu, Lian-Ao; Modugno, Michele; Yao, Wang; Shao, Bin

    2013-01-01

    We show that a category of one-dimensional XY-type models may enable high-fidelity quantum state transmissions, regardless of details of coupling configurations. This observation leads to a fault-tolerant design of a state transmission setup. The setup is fault-tolerant, with specified thresholds, against engineering failures of coupling configurations, fabrication imperfections or defects, and even time-dependent noises. We propose an experimental implementation of the fault-tolerant scheme using hard-core bosons in one-dimensional optical lattices. PMID:24185259

  11. Aceclofenac in the management of inflammatory pain.

    PubMed

    Legrand, Erik

    2004-06-01

    Aceclofenac (Almirall Prodesfarma SA) is an oral NSAID that is effective in the treatment of painful inflammatory diseases and has been used to treat > 75 million patients worldwide. It has proved as effective as diclofenac, naproxen and piroxicam in patients with osteoarthritis, diclofenac, ketorolac, tenoxicam and indomethacin in patients with rheumatoid arthritis and tenoxicam, naproxen and indomethacin in patients with ankylosing spondylitis. It also provides effective analgesia in other indications, such as dental or gynaecological pain, lower back pain and ear, nose and throat indications. Aceclofenac appears to be particularly well-tolerated amongst the NSAIDs, with a lower incidence of gastrointestinal adverse effects. This good tolerability profile results in a reduced withdrawal rate and hence greater compliance with treatment. PMID:15163279

  12. Pain in People with Learning Disabilities in Residential Settings--The Need for Change

    ERIC Educational Resources Information Center

    Beacroft, Monica; Dodd, Karen

    2010-01-01

    This audit investigated residential staff beliefs around pain thresholds and strategies they adopt to recognise and manage pain in people with learning disabilities across Surrey. A structured interview was constructed to elicit information. Results demonstrated that pain is not being effectively recognised or managed by residential staff in…

  13. Acceptance- versus Change-Based Pain Management: The Role of Psychological Acceptance

    ERIC Educational Resources Information Center

    Blacker, Kara J.; Herbert, James D.; Forman, Evan M.; Kounios, John

    2012-01-01

    This study compared two theoretically opposed strategies for acute pain management: an acceptance-based and a change-based approach. These two strategies were compared in a within-subjects design using the cold pressor test as an acute pain induction method. Participants completed a baseline pain tolerance assessment followed by one of the two

  14. Acceptance- versus Change-Based Pain Management: The Role of Psychological Acceptance

    ERIC Educational Resources Information Center

    Blacker, Kara J.; Herbert, James D.; Forman, Evan M.; Kounios, John

    2012-01-01

    This study compared two theoretically opposed strategies for acute pain management: an acceptance-based and a change-based approach. These two strategies were compared in a within-subjects design using the cold pressor test as an acute pain induction method. Participants completed a baseline pain tolerance assessment followed by one of the two…

  15. The importance of mental pain and physical dissociation in youth suicidality.

    PubMed

    Levinger, Shai; Somer, Eli; Holden, Ronald R

    2015-01-01

    This study examines the importance of two suicide risk factors, mental pain and physical dissociation, among young people. Participants were 42 suicidal inpatients, 36 nonsuicidal inpatients, and 45 nonclinical participants. Overall, suicide attempters reported a stronger intensity of and lower tolerance for mental pain and more physical dissociation compared to the other two groups. Suicide attempters with a low tolerance for mental pain showed a higher level of dissociation from pain and insensitivity to bodily cues compared to nonsuicidal inpatients with similar levels of tolerance for mental pain. Physical dissociation contributed significantly to the likelihood of suicidality beyond the contribution of mental pain. Our results accentuate the importance of the combination of mental pain and physical dissociation in suicidality. Further research on the applicability of our findings to self-injurious behavior is warranted. PMID:25760400

  16. Pain perception in people with Down syndrome: a synthesis of clinical and experimental research

    PubMed Central

    McGuire, Brian E.; Defrin, Ruth

    2015-01-01

    People with an intellectual disability experience both acute and chronic pain with at least the same frequency as the general population. However, considerably less is known about the pain perception of people with Down syndrome. In this review paper, we evaluated the available clinical and experimental evidence. Some experimental studies of acute pain have indicated that pain threshold was higher than normal but only when using a reaction time method to measure pain sensitivity. However, when reaction time is not part of the calculation of the pain threshold, pain sensitivity in people with Down syndrome is in fact lower than normal (more sensitive to pain). Clinical studies of chronic pain have shown that people with an intellectual disability experience chronic pain and within that population, people with Down syndrome also experience chronic pain, but the precise prevalence of chronic pain in Down syndrome has yet to be established. Taken together, the literature suggests that people with Down syndrome experience pain, both acute and chronic, with at least the same frequency as the rest of the population. Furthermore, the evidence suggests that although acute pain expression appears to be delayed, once pain is registered, there appears to be a magnified pain response. We conclude by proposing an agenda for future research in this area. PMID:26283936

  17. Stress-Induced Pain: A Target for the Development of Novel Therapeutics

    PubMed Central

    Johnson, Anthony C.

    2014-01-01

    Although current therapeutics provide relief from acute pain, drugs used for treatment of chronic pain are typically less efficacious and limited by adverse side effects, including tolerance, addiction, and gastrointestinal upset. Thus, there is a significant need for novel therapies for the treatment of chronic pain. In concert with chronic pain, persistent stress facilitates pain perception and sensitizes pain pathways, leading to a feed-forward cycle promoting chronic pain disorders. Stress exacerbation of chronic pain suggests that centrally acting drugs targeting the pain- and stress-responsive brain regions represent a valid target for the development of novel therapeutics. This review provides an overview of how stress modulates spinal and central pain pathways, identifies key neurotransmitters and receptors within these pathways, and highlights their potential as novel targets for therapeutics to treat chronic pain. PMID:25194019

  18. Pain in critically ill patients with substance use disorder or long-term opioid use for chronic pain.

    PubMed

    Drew, Debra J; St Marie, Barbara J

    2011-01-01

    Opioid tolerance resulting from long-term opioid consumption for chronic pain or from substance use disorder adds a layer of complexity to managing pain in the critical care setting. This article discusses similarities and differences of these 2 conditions. The phenomenon of tolerance and opioid-induced hyperalgesia are presented. Prevention of opioid withdrawal, when patients are on methadone or buprenorphine, is described. An overview of the neurophysiology of pain and substance use disorder is presented. Practical clinical suggestions are given to assist the critical care nurse in caring for these complex patients. PMID:21808159

  19. Central Neuropathic Pain Syndromes.

    PubMed

    Watson, James C; Sandroni, Paola

    2016-03-01

    Chronic pain is common in patients with neurologic complications of a central nervous system insult such as stroke. The pain is most commonly musculoskeletal or related to obligatory overuse of neurologically unaffected limbs. However, neuropathic pain can result directly from the central nervous system injury. Impaired sensory discrimination can make it challenging to differentiate central neuropathic pain from other pain types or spasticity. Central neuropathic pain may also begin months to years after the injury, further obscuring recognition of its association with a past neurologic injury. This review focuses on unique clinical features that help distinguish central neuropathic pain. The most common clinical central pain syndromes-central poststroke pain, multiple sclerosis-related pain, and spinal cord injury-related pain-are reviewed in detail. Recent progress in understanding of the pathogenesis of central neuropathic pain is reviewed, and pharmacological, surgical, and neuromodulatory treatments of this notoriously difficult to treat pain syndrome are discussed. PMID:26944242

  20. [Clinical variants of pain syndromes in patients with Parkinson's disease].

    PubMed

    Makhnev, S O; Levin, O S

    2013-01-01

    Parkinson's disease (PD) is characterized by well-known motor symptoms as well as by non-motor symptoms including pain syndrome which remains poorly understood and often ignored by physicians. The purpose of this study was to determine the frequency of chronic pain syndrome and develop approaches to its diagnosis, treatment and systematization. Authors examined 130 patients with PD. Chronic pain was found in 68 (52%) patients. In 51 (75%) patients, pain was located on the side of more severe motor symptoms. The main types of pain in PD were identified related to regional changes in muscle tone, motor fluctuations and primary ("central" pain). More severe symptoms of parkinsonism, cognitive and affective disorders as well as lower pain threshold were identified in patients with pain compared to those without pain. A negative impact of pain on quality of life was shown. The positive effect of dopaminergic therapy on the severity of pain was found in one-third of patients with PD. Criteria for the association of pain with PD and approaches to the correction of different types of pain are discussed. PMID:23994930

  1. Perioperative management of the opioid tolerant patient for orthopedic surgery.

    PubMed

    Mahathanaruk, Marchyarn; Hitt, James; de LeonCasasola, Oscar A

    2014-12-01

    The prevalence of opioid use in the North America and some countries of the European Union has resulted in an increase in the number of patients who may exhibit opioid tolerance when requiring postoperative pain management. The approach to postoperative pain control in these patients is different from the strategies used in opioid-naïve patients. Better understanding of the cellular mechanisms of opioid tolerance in animals has resulted in the transfer of these concepts from the basic research to the clinical arena. This article presents new developments in opioid tolerance and how this knowledge can be applied to clinical practice. PMID:25453671

  2. Race effects on temporal summation to heat pain in youth.

    PubMed

    Morris, Matthew C; Walker, Lynn; Bruehl, Stephen; Hellman, Natalie; Sherman, Amanda L; Rao, Uma

    2015-05-01

    Racial differences in pain responsiveness have been demonstrated in adults. However, it is unclear whether racial differences are also present in youth and whether they extend to experimental pain indices assessing temporal summation of second pain (TSSP). Temporal summation of second pain provides an index of pain sensitivity and may be especially relevant in determining risk for chronic pain. This study assessed pain tolerance and TSSP to evoked thermal pain in 78 healthy youth (age range, 10-17), 51% of whom were African American and 49% were non-Hispanic white. Multilevel models revealed within-individual increases in pain ratings during the temporal summation task in non-Hispanic white youth that were consistent with TSSP. Pain ratings did not change significantly during the temporal summation task in African-American youth. Baseline evoked pain ratings were significantly higher in African-American compared with non-Hispanic white youth. These findings suggest that enhanced responsiveness to evoked thermal pain in African Americans is present in adolescence but is unlikely to be related to elevated TSSP. These results may have implications for understanding racial differences in chronic pain experience in adulthood. PMID:25734994

  3. Descending pain modulation and chronification of pain

    PubMed Central

    Ossipov, Michael H.; Morimura, Kozo; Porreca, Frank

    2015-01-01

    Purpose of review Chronic pain is an important public health problem that negatively impacts quality of life of affected individuals and exacts an enormous socio-economic cost. Currently available therapeutics provide inadequate management of pain in many patients. Acute pain states generally resolve in most patients. However, for reasons that are poorly understood, in some individuals, acute pain can transform to a chronic state. Our understanding of the risk factors that underlie the development of chronic pain is limited. Recent studies have suggested an important contribution of dysfunction in descending pain modulatory circuits to pain ‘chronification’. Human studies provide insights into possible endogenous and exogenous factors that may promote the conversion of pain into a chronic condition. Recent findings Descending pain modulatory systems have been studied and characterized in animal models. Human brain imaging techniques, deep brain stimulation and the mechanisms of action of drugs that are effective in the treatment of pain confirm the clinical relevance of top-down pain modulatory circuits. Growing evidence supports the concept that chronic pain is associated with a dysregulation in descending pain modulation. Disruption of the balance of descending modulatory circuits to favour facilitation may promote and maintain chronic pain. Recent findings suggest that diminished descending inhibition is likely to be an important element in determining whether pain may become chronic. This view is consistent with the clinical success of drugs that enhance spinal noradrenergic activity, such as serotonin/norepinephrine reuptake inhibitors (SNRIs), in the treatment of chronic pain states. Consistent with this concept, a robust descending inhibitory system may be normally engaged to protect against the development of chronic pain. Imaging studies show that higher cortical and subcortical centres that govern emotional, motivational and cognitive processes communicate directly with descending pain modulatory circuits providing a mechanistic basis to explain how exogenous factors can influence the expression of chronic pain in a susceptible individual. Summary Preclinical studies coupled with clinical pharmacologic and neuroimaging investigations have advanced our understanding of brain circuits that modulate pain. Descending pain facilitatory and inhibitory circuits arising ultimately in the brainstem provide mechanisms that can be engaged to promote or protect against pain ‘chronification’. These systems interact with higher centres, thus providing a means through which exogenous factors can influence the risk of pain chronification. A greater understanding of the role of descending pain modulation can lead to novel therapeutic directions aimed at normalizing aberrant processes that can lead to chronic pain. PMID:24752199

  4. miR-155 modulates the progression of neuropathic pain through targeting SGK3

    PubMed Central

    Liu, Shaoxing; Zhu, Bo; Sun, Yan; Xie, Xianfeng

    2015-01-01

    This study aimed to illustrate the potential effects of miR-155 in neuropathic pain and its potential mechanism. Spragure-Dawley (SD) rats were used for neuropathic pain model of bilateral chronic constriction injury (bCCI) construction. Effects of miR-155 expression on pain threshold of mechanical stimuli (MWT), paw withdrawal threshold latency (PMTL) and cold threshold were analyzed. Target for miR-155 was analyzed using bioinformatics methods. Moreover, effects of miR-155 target gene expression on pain thresholds were also assessed. Compared with the controls and sham group, miR-155 was overexpressed in neuropathic pain rats (P<0.05), but miR-155 slicing could significantly decreased the pain thresholds (P<0.05). Serum and glucocorticoid regulated protein kinase 3 (SGK3) was predicted as the target gene for miR-155, and miR-155 expression was negatively correlated to SGK3 expression. Furthermore, SGK3 overexpression could significantly decreased the pain thresholds which was the same as miR-155 (P<0.05). Moreover, miR-155 slicing and SGK3 overexpression could significantly decrease the painthreshold. The data presented in this study suggested that miR-155 slicing could excellently alleviate neuropathic pain in rats through targeting SGK3 expression. miR-155 may be a potential therapeutic target for neuropathic pain treatment. PMID:26823753

  5. Network problem threshold

    NASA Technical Reports Server (NTRS)

    Gejji, Raghvendra, R.

    1992-01-01

    Network transmission errors such as collisions, CRC errors, misalignment, etc. are statistical in nature. Although errors can vary randomly, a high level of errors does indicate specific network problems, e.g. equipment failure. In this project, we have studied the random nature of collisions theoretically as well as by gathering statistics, and established a numerical threshold above which a network problem is indicated with high probability.

  6. Activation-threshold tuning in an affinity model for the T-cell repertoire.

    PubMed Central

    Scherer, Almut; Noest, Andr; de Boer, Rob J.

    2004-01-01

    Naive T cells respond to peptides from foreign proteins and remain tolerant to self peptides from endogenous proteins. It has been suggested that self tolerance comes about by a 'tuning' mechanism, i.e. by increasing the T-cell activation threshold upon interaction with self peptides. Here, we explore how such an adaptive mechanism of T-cell tolerance would influence the reactivity of the T-cell repertoire to foreign peptides. We develop a computer simulation model in which T cells are tolerized by increasing their activation-threshold dependent on the affinity with which they see self peptides presented in the thymus. Thus, different T cells acquire different activation thresholds (i.e. different cross-reactivities). In previous mathematical models, T-cell tolerance was deletional and based on a fixed cross-reactivity parameter, which was assumed to have evolved to an optimal value. Comparing these two different tolerance-induction mechanisms, we found that the tuning model performs somewhat better than an optimized deletion model in terms of the reactivity to foreign antigens. Thus, evolutionary optimization of clonal cross-reactivity is not required. A straightforward extension of the tuning model is to delete T-cell clones that obtain a too high activation threshold, and to replace these by new clones. The reactivity of the immune repertoires of such a replacement model is enchanced compared with the basic tuning model. These results demonstrate that activation-threshold tuning is a functional mechanism for self tolerance induction. PMID:15156919

  7. Prediction of post-operative pain following arthroscopic subacromial decompression surgery: an observational study

    PubMed Central

    Davis, Anthony

    2013-01-01

    Background: Arthroscopic shoulder surgery is increasingly performed as a day case procedure. Optimal post-operative pain relief remains a challenge due to considerable variations in the level of pain experienced between individuals. Our aim was to examine whether the preoperative electrical pain threshold was a strong predictor of elevated postoperative pain levels following arthroscopic subacromial decompression (ASD) surgery. Methods: Forty consenting patients with American Society of Anesthesiologists (ASA) grade 1-2 presenting for elective ASD surgery were recruited. Patients’ electrical pain thresholds were measured preoperatively using a PainMatcher® (Cefar Medical AB, Lund, Sweden) device. Following surgery under general anaesthesia, the maximum pain experienced at rest and movement was recorded using a visual analogue scale until the end of postoperative day four. Results: In univariate analyses (t-test), the postoperative pain experienced (Area Under Curve) was significantly greater in patients with a low pain threshold as compared with a high pain threshold at both rest (mean 12.5, S.E. 1.7 v mean 6.5, S.E.1.2. P=0.008) and on movement (mean 18.7, S.E. 1.5 v mean 14.1, S.E.1.4. P=0.031). In multivariate analyses, adjusting for additional extra analgesia, the pain experienced postoperatively was significantly greater in the low pain threshold group both at rest (mean difference 4.9, 95% CI 1.5 to 8.4, P=0.007) and on movement (mean difference 4.1, 95%CI 0.03 to 8.2, P=0.049). Conclusions: Preoperative pain threshold can predict postoperative pain level following ASD of the shoulder. Trial registration: Clinicaltrials.gov identifier: NCT01351363 Level of Evidence: II PMID:24358863

  8. Physicians Experience with and Expectations of the Safety and Tolerability of WHO-Step III Opioids for Chronic (Low) Back Pain: Post Hoc Analysis of Data from a German Cross-Sectional Physician Survey

    PubMed Central

    Ueberall, Michael A.; Eberhardt, Alice; Mueller-Schwefe, Gerhard H. H.

    2015-01-01

    Objective. To describe physicians' daily life experience with WHO-step III opioids in the treatment of chronic (low) back pain (CLBP). Methods. Post hoc analysis of data from a cross-sectional online survey with 4.283 Germany physicians. Results. With a reported median use in 17% of affected patients, WHO-step III opioids play a minor role in treatment of CLBP in daily practice associated with a broad spectrum of positive and negative effects. If prescribed, potent opioids were reported to show clinically relevant effects (such as ≥50% pain relief) in approximately 3 of 4 patients (median 72%). Analgesic effects reported are frequently related with adverse events (AEs). Only 20% of patients were reported to remain free of any AE. Most frequently reported AE was constipation (50%), also graded highest for AE-related daily life restrictions (median 46%). Specific AE countermeasures were reported to be necessary in approximately half of patients (median 45%); nevertheless AE-related premature discontinuation rates reported were high (median 22%). Fentanyl/morphine were the most/least prevalently prescribed potent opioids mentioned (median 20 versus 8%). Conclusion. Overall, use of WHO-step III opioids for CLBP is low. AEs, especially constipation, are commonly reported and interfere significantly with analgesic effects in daily practice. Nevertheless, beneficial effects outweigh related AEs in most patients with CLBP. PMID:26568890

  9. A novel psychovisual threshold on large DCT for image compression.

    PubMed

    Abu, Nur Azman; Ernawan, Ferda

    2015-01-01

    A psychovisual experiment prescribes the quantization values in image compression. The quantization process is used as a threshold of the human visual system tolerance to reduce the amount of encoded transform coefficients. It is very challenging to generate an optimal quantization value based on the contribution of the transform coefficient at each frequency order. The psychovisual threshold represents the sensitivity of the human visual perception at each frequency order to the image reconstruction. An ideal contribution of the transform at each frequency order will be the primitive of the psychovisual threshold in image compression. This research study proposes a psychovisual threshold on the large discrete cosine transform (DCT) image block which will be used to automatically generate the much needed quantization tables. The proposed psychovisual threshold will be used to prescribe the quantization values at each frequency order. The psychovisual threshold on the large image block provides significant improvement in the quality of output images. The experimental results on large quantization tables from psychovisual threshold produce largely free artifacts in the visual output image. Besides, the experimental results show that the concept of psychovisual threshold produces better quality image at the higher compression rate than JPEG image compression. PMID:25874257

  10. A Novel Psychovisual Threshold on Large DCT for Image Compression

    PubMed Central

    2015-01-01

    A psychovisual experiment prescribes the quantization values in image compression. The quantization process is used as a threshold of the human visual system tolerance to reduce the amount of encoded transform coefficients. It is very challenging to generate an optimal quantization value based on the contribution of the transform coefficient at each frequency order. The psychovisual threshold represents the sensitivity of the human visual perception at each frequency order to the image reconstruction. An ideal contribution of the transform at each frequency order will be the primitive of the psychovisual threshold in image compression. This research study proposes a psychovisual threshold on the large discrete cosine transform (DCT) image block which will be used to automatically generate the much needed quantization tables. The proposed psychovisual threshold will be used to prescribe the quantization values at each frequency order. The psychovisual threshold on the large image block provides significant improvement in the quality of output images. The experimental results on large quantization tables from psychovisual threshold produce largely free artifacts in the visual output image. Besides, the experimental results show that the concept of psychovisual threshold produces better quality image at the higher compression rate than JPEG image compression. PMID:25874257

  11. Cancer-related pain management in clinical oncology.

    PubMed

    Cipta, Andre M; Pietras, Christopher J; Weiss, Timothy E; Strouse, Thomas B

    2015-10-01

    Uncontrolled pain is one of the most feared and debilitating symptoms among cancer patients, and many suffer unnecessarily from suboptimal pain control. Cancer-related pain is often multidimensional and can affect all aspects of a patient's life. Hence, achieving adequate pain relief among cancer patients involves a proper assessment of psychosocial, spiritual, and physical pain issues, matched with an individualized treatment plan involving pharmacologic, nonpharmacologic, and procedural therapies when appropriate. Providing effective pain relief can help ease the overall burden of disease among oncology patients while helping them tolerate cancer-directed therapies and achieve the most optimal quality of life throughout all phases of the disease continuum. In this review, the authors will discuss the syndromes, assessment of, and treatment for cancer-related pain in the outpatient setting. PMID:26862909

  12. Preclinical Assessment of Inflammatory Pain.

    PubMed

    Muley, Milind M; Krustev, Eugene; McDougall, Jason J

    2016-02-01

    While acute inflammation is a natural physiological response to tissue injury or infection, chronic inflammation is maladaptive and engenders a considerable amount of adverse pain. The chemical mediators responsible for tissue inflammation act on nociceptive nerve endings to lower neuronal excitation threshold and sensitize afferent firing rate leading to the development of allodynia and hyperalgesia, respectively. Animal models have aided in our understanding of the pathophysiological mechanisms responsible for the generation of chronic inflammatory pain and allowed us to identify and validate numerous analgesic drug candidates. Here we review some of the commonly used models of skin, joint, and gut inflammatory pain along with their relative benefits and limitations. In addition, we describe and discuss several behavioral and electrophysiological approaches used to assess the inflammatory pain in these preclinical models. Despite significant advances having been made in this area, a gap still exists between fundamental research and the implementation of these findings into a clinical setting. As such we need to characterize inherent pathophysiological pathways and develop new endpoints in these animal models to improve their predictive value of human inflammatory diseases in order to design safer and more effective analgesics. PMID:26663896

  13. Pain and pain management in dermatology.

    PubMed

    Beiteke, Ulrike; Bigge, Stefan; Reichenberger, Christina; Gralow, Ingrid

    2015-10-01

    It is estimated that 23 million Germans suffer from chronic pain. A recent survey has revealed that 30 % of chronic pain patients are dissatisfied with their pain management. Furthermore, five million Germans suffer from neuropathic pain, 20 % of whom are inadequately treated. Pain is also a symptom of many dermatologic diseases, which is mostly somatic and may be classified as mild in the majority of cases. Nevertheless, research on the quality of life (QoL) has increasingly shown a marked impairment of QoL by moderate pain such as in psoriatic arthritis. -Severe pain is associated with herpes zoster (shingles), leg ulcers, and pyoderma gangrenosum. This article addresses the basics of pain classification and, in a short excerpt, pain transduction/transmission and modulation. The use of standardized diagnostic -scales is recommended for the purpose of recording and monitoring pain intensity, which allows for the optimization of therapy and consistent interdisciplinary -communication. Any dermatology residency program includes the acquisition of knowledge and skills in pain management. This review therefore aims to present fundamental therapeutic concepts based on the expanded WHO analgesic ladder, and describes a step-wise therapeutic approach and combination therapies. The article focuses on the pain management of the above-mentioned severely painful, conservatively treated dermatoses. Besides well-established therapeutic agents and current -therapeutic standards, it discusses specific options based on guidelines (where available). Current knowledge on peri- and postoperative pain management is briefly outlined. This article addresses: ▸ The fundamentals of the classification and neurophysiology of pain; ▸ Standards for pain documentation in children and adults; ▸ General standards for pharmaceutical pain management; ▸ Current specific treatment options for postherpetic neuralgia, leg ulcers, and -pyoderma gangrenosum in conjunction with the expanded WHO analgesic -ladder. PMID:26408457

  14. Pharmacotherapy for breakthrough cancer pain.

    PubMed

    Mercadante, Sebastiano

    2012-01-22

    Breakthrough pain (BTP) is a transient exacerbation of pain that occurs either spontaneously, or in relation to a specific predictable or unpredictable trigger, despite relatively stable and adequately controlled background pain. The principal pharmacological treatment of BTP is represented by the administration of opioids as needed. Oral opioids have traditionally been the only available drugs for BTP. However, the onset and duration of action of oral opioids such as morphine or oxycodone may not be suitable for treating many episodes of BTP that are of short onset and duration. Transmucosal administration of lipophilic substances has gained a growing popularity in recent years due to the rapid effect, clinically observable 10-15 minutes after drug administration, and the non-invasive form. Different technologies have been developed to provide fast pain relief with potent opioid drugs such fentanyl, delivered by non-invasive routes (rapid onset opioids, ROOs). All the studies performed with ROOs have recommended that these drugs should be administered to opioid-tolerant patients receiving doses of oral morphine equivalents of at least 60?mg. These preparations, including oral transmucosal fentanyl citrate, fentanyl buccal tablet, sublingual fentanyl, intranasal fentanyl spray, fentanyl-pectin nasal spray and fentanyl buccal soluble film have shown better efficacy than placebo or oral opioids. Long-term studies have confirmed their efficacy and safety. PMID:22233484

  15. Pain from bluebottle jellyfish stings.

    PubMed

    Li, Li; McGee, Richard G; Webster, Angela C

    2015-07-01

    An 11-year-old girl presented to the emergency department with severe pain after a jellyfish sting at a New South Wales beach. Bluebottle (Physalia) jellyfish was deemed the most likely cause considering her geographical location. The Australian Resuscitation Council Guideline (2010) suggests immersing in water as hot as can be tolerated for 20 min for treating pain from jellyfish stings. This guideline was written based on past case reports, books and randomised controlled trials (RCTs). We performed a search to assess the most current evidence for relief of pain from Bluebottle jellyfish stings, which yielded two systematic reviews and seven RCTs. Both systematic reviews had similar conclusions, with one of the RCTs used in both reviews showing the most relevance to our presenting patient in terms of demographics, location and jellyfish type. This journal club article is an appraisal of this RCT by Loten et al. and the validity of its conclusion that hot water immersion is most effective for the relief of pain from Bluebottle stings. PMID:26135148

  16. Therapy of metastatic bone pain.

    PubMed

    Serafini, A N

    2001-06-01

    Bone metastasis is a common sequella of solid malignant tumors such as prostate, breast, lung, and renal cancers, which can lead to various complications, including fractures, hypercalcemia, and bone pain, as well as reduced performance status and quality of life. A multidisciplinary approach is usually required not only to address the etiology of the pain and its complicating factors but also to treat the patient appropriately. Currently, the treatment of bone pain remains palliative at best with systemic therapy (analgesics, hormones, chemotherapy, steroids, and bisphosphonates) as well as local treatments (such as surgery, nerve blocks, and external beam radiation). However, many of these treatments are limited in their efficacy or duration and have significant side effects that seriously limit the cancer patient's quality of life. Various radiopharmaceuticals have shown good efficacy in relieving bone pain secondary to bone metastasis. This systemic form of metabolic radiotherapy is simple to administer and complements other treatment options. This has been associated with improved mobility in many patients, reduced dependence on narcotic and non-narcotic analgesics, improved performance status and quality of life, and, in some studies, improved survival. Additional radiopharmaceuticals are under investigation and appear promising. All of these agents, although comprising different physical and chemical characteristics, offer certain advantages in that they are simple to administer, are well tolerated by the patient if used appropriately, and can be used alone or in combination with the other forms of treatment. PMID:11390554

  17. Central Pain Syndrome

    MedlinePlus

    ... Enhancing Diversity Find People About NINDS NINDS Central Pain Syndrome Information Page Table of Contents (click to ... being done? Clinical Trials Organizations What is Central Pain Syndrome? Central pain syndrome is a neurological condition ...

  18. Pain medications - narcotics

    MedlinePlus

    Painkillers; Drugs for pain; Analgesics; Opioids ... Narcotics are also called opioid pain relievers. They are used only for pain that is severe and is not helped by other types of painkillers. When used ...

  19. Complex Regional Pain Syndrome

    MedlinePlus

    ... Diversity Find People About NINDS NINDS Complex Regional Pain Syndrome Information Page Synonym(s): Reflex Sympathetic Dystrophy Syndrome, ... Additional resources from MedlinePlus What is Complex Regional Pain Syndrome? Complex regional pain syndrome (CRPS) is a ...

  20. NIH Pain Consortium

    MedlinePlus

    ... Excellence in Pain Education Trailer Tweets by @NIHPainResearch space The NIH Pain Consortium was established to enhance pain research and promote collaboration among researchers across the many ...

  1. Pain and your emotions

    MedlinePlus

    ... separated. The way your mind controls thoughts and attitudes affects the way your body controls pain. Pain ... Elsevier Saunders; 2012:chap 100. Turk DC. Psychosocial aspects of chronic pain. In: Benzon HT. Practical Management ...

  2. What Is Back Pain?

    MedlinePlus

    ... some types of treatments for chronic back pain. Hot or Cold Packs (or Both) Hot or cold packs can soothe sore, stiff backs. ... helps reduce swelling and numbs deep pain. Using hot or cold packs may relieve pain, but this ...

  3. Palliative care - managing pain

    MedlinePlus

    End of life - pain management; Hospice - pain management ... or if you have side effects from your pain treatments. ... Bookbinder M, McHugh ME. Symptom management in palliative care and ... Medicine . 1st ed. Philadelphia, PA: Elsevier Saunders; 2008:chap ...

  4. Techniques for assessing knee joint pain in arthritis

    PubMed Central

    Neugebauer, Volker; Han, Jeong S; Adwanikar, Hita; Fu, Yu; Ji, Guangchen

    2007-01-01

    The assessment of pain is of critical importance for mechanistic studies as well as for the validation of drug targets. This review will focus on knee joint pain associated with arthritis. Different animal models have been developed for the study of knee joint arthritis. Behavioral tests in animal models of knee joint arthritis typically measure knee joint pain rather indirectly. In recent years, however, progress has been made in the development of tests that actually evaluate the sensitivity of the knee joint in arthritis models. They include measurements of the knee extension angle struggle threshold, hind limb withdrawal reflex threshold of knee compression force, and vocalizations in response to stimulation of the knee. A discussion of pain assessment in humans with arthritis pain conditions concludes this review. PMID:17391515

  5. The effect of repeated intramuscular alfentanil injections on experimental pain and abuse liability indices in healthy males

    PubMed Central

    Tompkins, D. Andrew; Smith, Michael T.; Bigelow, George E.; Moaddel, Ruin; Venkata, S.L. Vatem; Strain, Eric C.

    2013-01-01

    Objective Opioid-induced hyperalgesia (OIH), increased sensitivity to noxious stimuli following repeated opioid exposures, has been demonstrated in pre-clinical studies. However, there is no accepted, prospective model of OIH following repeated opioid exposures currently available in humans. This study assessed a potential prospective OIH model. Methods Double-blind intramuscular (IM) injections of a short-acting opioid, (alfentanil 15 mcg/kg; N=8) were compared to active placebo (diphenhydramine 25 mg; N=3) on cold and pressure pain testing and standard abuse liability measures in eight 10-hour sessions (1 injection/session) over 4–5 weeks in healthy pain-free males. Decreases from session baseline pain threshold (PThr) and tolerance (PTol) were calculated to represent hyperalgesia, and were assessed both within and across sessions. Results Mean decreases in cold PTol were seen in the alfentanil group at 180 minutes (−3.8 seconds, +/−26.5) and 480 minutes (−1.63 seconds, +/−31.5) after drug administration. There was a trend for differences between conditions on cold PThr hyperalgesia but not for pressure PThr. Alfentanil participants had greater mean ratings on LIKING and HIGH visual analog scales at peak effects (30 minutes), but these scores did not change across sessions. Discussion Repeated alfentanil exposures over 4–5 weeks resulted in within session decreases in cold pain tolerance from baseline but these differences were not substantially different from diphenhydramine controls. The results did not support the phenomenon of OIH in this model, although definitive conclusions regarding the existence of OIH in humans likely requires a larger sample size or an alternative model. PMID:23446076

  6. A direct comparison of affective pain processing underlying two traditional pain modalities in rodents.

    PubMed

    McNabb, C T; Uhelski, M L; Fuchs, P N

    2012-01-17

    In the preclinical study of pain, two commonly used pain models are the L5 spinal nerve ligation (SNL) and the injection of carrageenan. Using a modified place escape/avoidance paradigm (mPEAP), a novel behavioral test that quantifies aversive behavior evoked by painful stimuli, we directly compared the affective component of the SNL and inflammation models. Fifty three Sprague-Dawley rats underwent baseline mechanical paw withdrawal threshold (MPWT) and mPEAP testing followed by an L5 SNL or sham surgery for the left paw and then a carrageenan or saline injection for the right paw. After recovering, animals underwent post-manipulation MPWT and mPEAP tests. Both pain conditions produced mechanical hypersensitivity, and animals with a single-paw condition demonstrated escape/avoidance behavior in response to stimulation of the affected paw. Animals with the bilateral pain condition did not show a preference for stimulation of one paw versus the other paw, and the avoidance behavior was not significantly different from the sham/saline control. The results indicate that the pain models are associated with significant avoidance behavior and that they produce comparable degrees of pain affect. These findings advance the preclinical study of pain by validating the simultaneous utilization of the SNL and inflammation models and will allow future studies that combine pain conditions to more closely resemble clinical conditions. PMID:22172927

  7. Dental (Odontogenic) Pain

    PubMed Central

    Renton, Tara

    2011-01-01

    This article provides a simple overview of acute trigeminal pain for the non dentist. This article does not cover oral mucosal diseases (vesiculobullous disorders) that may cause acute pain. Dental pain is the most common in this group and it can present in several different ways. Of particular interest for is that dental pain can mimic both trigeminal neuralgia and other chronic trigeminal pain disorders. It is crucial to exclude these disorders whilst managing patients with chronic trigeminal pain. PMID:26527224

  8. Assessing cancer pain.

    PubMed

    Dalal, Shalini; Bruera, Eduardo

    2012-08-01

    Regular assessment for the presence of pain and response to pain management strategies should be high priority in cancer patients. Pain is a multidimensional experience in cancer patients. Pain management will be most effective when treatments are individualized after exploring the various physical and non-physical components of pain, and the patient and family are educated and involved in decision making. This article discusses the various issues that are pertinent to the assessment of pain in cancer patients. PMID:22585314

  9. Pain sensitivity in major depression and its relationship to central serotoninergic function as reflected by the neuroendocrine response to clomipramine.

    PubMed

    Kundermann, Bernd; Hemmeter-Spernal, Julia; Strate, Peter; Gebhardt, Stefan; Huber, Martin Tobias; Krieg, Jürgen-Christian; Lautenbacher, Stefan

    2009-12-01

    Several studies reported a decreased pain sensitivity in patients with depression, but the underlying neurobiological mechanisms of this phenomenon are unclear. While there is extensive evidence that the serotoninergic system plays a key role in pain modulation, especially in pain inhibitory mechanisms via descending pathways, as well as in the pathophysiology of depression, no study so far has examined its potential relevance in mediating the alteration of pain processing. The present study addresses the question of whether indices of serotoninergic dysfunction, as investigated by a neuroendrocine challenge paradigm, are related to pain sensitivity. Nineteen drug-free inpatients with unipolar major depression underwent a neuroendocrine challenge test by measuring cortisol and prolactin in response to intravenously administered clomipramine (12.5mg). Heat/cold pain thresholds, warmth/cold detection thresholds, measures of current pain complaints and mood were assessed the day before and three day after challenge procedure. When patients were classified in subgroups based on a median split of their cortisol response values, the low-responsive group showed significantly elevated heat pain thresholds and nearly significantly elevated cold pain thresholds compared to the high-responsive group. No such group differences were found with regard to somatosensory thresholds, measures of pain complaints and mood. Subgrouping on the basis of prolactin responsiveness did not reveal significant differences in any parameter. In summary, a decreased pain sensitivity was demonstrated in patients characterized by a reduced neuroendocrine responsiveness to clomipramine, suggesting an involvement of serotoninergic dysfunction underlying altered pain perception in depression. PMID:19467668

  10. Gas threshold Cerenkov counters

    NASA Technical Reports Server (NTRS)

    Logachev, V. I.; Sinitsyna, V. G.; Chukin, V. S.

    1975-01-01

    The report describes two designs are reported of gas threshold Cerenkov counters for recording electrons of primary cosmic rays without recording protons. Also presented are design and technological measures which ensure maximum light collection of the Cerenkov radiation originating on the photocathode of the photomultiplier inside the radiator. The dependence of the reflection factor on the length of the light wave for different coatings is shown as well as for the throughput of the different optical materials employed. A range of methods for determining the efficiency of the counters during the recording of cosmic ray nucons and ways of increasing it further are given.

  11. Orofacial pain: a primer.

    PubMed

    De Rossi, Scott S

    2013-07-01

    Orofacial pain refers to pain associated with the soft and hard tissues of the head, face, and neck. It is a common experience in the population that has profound sociologic effects and impact on quality of life. New scientific evidence is constantly providing insight into the cause and pathophysiology of orofacial pain including temporomandibular disorders, cranial neuralgias, persistent idiopathic facial pains, headache, and dental pain. An evidence-based approach to the management of orofacial pain is imperative for the general clinician. This article reviews the basics of pain epidemiology and neurophysiology and sets the stage for in-depth discussions of various painful conditions of the head and neck. PMID:23809298

  12. Neuroplastic Effects of Transcranial Direct Current Stimulation on Painful Symptoms Reduction in Chronic Hepatitis C: A Phase II Randomized, Double Blind, Sham Controlled Trial

    PubMed Central

    Brietzke, Aline P.; Rozisky, Joanna R.; Dussan-Sarria, Jairo A.; Deitos, Alicia; Laste, Gabriela; Hoppe, Priscila F. T.; Muller, Suzana; Torres, Iraci L. S.; Alvares-da-Silva, Mário R.; de Amorim, Rivadavio F. B.; Fregni, Felipe; Caumo, Wolnei

    2016-01-01

    Introduction: Pegylated Interferon Alpha (Peg-IFN) in combination with other drugs is the standard treatment for chronic hepatitis C infection (HCV) and is related to severe painful symptoms. The aim of this study was access the efficacy of transcranial direct current stimulation (tDCS) in controlling the painful symptoms related to Peg-IFN side effects. Materials and Methods: In this phase II double-blind trial, twenty eight (n = 28) HCV subjects were randomized to receive either 5 consecutive days of active tDCS (n = 14) or sham (n = 14) during 5 consecutive days with anodal stimulation over the primary motor cortex region using 2 mA for 20 min. The primary outcomes were visual analogue scale (VAS) pain and brain-derived neurotrophic factor (BDNF) serum levels. Secondary outcomes were the pressure-pain threshold (PPT), the Brazilian Profile of Chronic Pain: Screen (B-PCP:S), and drug analgesics use. Results: tDCS reduced the VAS scores (P < 0.003), with a mean pain drop of 56% (p < 0.001). Furthermore, tDCS was able to enhance BDNF levels (p < 0.01). The mean increase was 37.48% in the active group. Finally, tDCS raised PPT (p < 0.001) and reduced the B-PCP:S scores and analgesic use (p < 0.05). Conclusions: Five sessions of tDCS were effective in reducing the painful symptoms in HCV patients undergoing Peg-IFN treatment. These findings support the efficacy of tDCS as a promising therapeutic tool to improve the tolerance of the side effects related to the use of Peg-IFN. Future larger studies (phase III and IV trials) are needed to confirm the clinical use of the therapeutic effects of tDCS in such condition. Trial registration: Brazilian Human Health Regulator for Research with the approval number CAAE 07802012.0.0000.5327. PMID:26793047

  13. A preliminary study on how hypohydration affects pain perception.

    PubMed

    Bear, Tracey; Philipp, Michael; Hill, Stephen; Mündel, Toby

    2016-05-01

    Chronic pain is a prevalent health issue with one in five people suffering from some form of chronic pain, with loss of productivity and medical costs of chronic pain considerable. However, the treatment of pain can be difficult, as pain perception is complex and can be affected by factors other than tissue damage. This study investigated the effect of hypohydration (mild, voluntary dehydration from ∼24 h of limiting fluid intake, mimicking someone drinking less than usual) on a person's pain perception. Seventeen healthy males (age 27 ± 5 years) visited the laboratory on three occasions, once as a familiarization and then twice again while either euhydrated (urine specific gravity: 1.008 ± 0.005) or hypohydrated (urine specific gravity: 1.024 ± 0.003, and -1.4 ± 0.9% body mass). Each visit, they performed a cold pressor test, where their feet were placed in cold water (0-3°C) for a maximum of 4 min. Measures of hydration status, pain sensitivity, pain threshold, and catastrophization were taken. We found that hypohydration predicted increased pain sensitivity (β = 0.43), trait pain catastrophizing, and baseline pain sensitivity (β = 0.37 and 0.47, respectively). These results are consistent with previous research, and suggest that a person's hydration status may be an important factor in their perception of acute pain. PMID:26785699

  14. Significant Determinants of Mouse Pain Behaviour

    PubMed Central

    Minett, Michael S.; Eijkelkamp, Niels; Wood, John N.

    2014-01-01

    Transgenic mouse behavioural analysis has furthered our understanding of the molecular and cellular mechanisms underlying damage sensing and pain. However, it is not unusual for conflicting data on the pain phenotypes of knockout mice to be generated by reputable groups. Here we focus on some technical aspects of measuring mouse pain behaviour that are often overlooked, which may help explain discrepancies in the pain literature. We examined touch perception using von Frey hairs and mechanical pain thresholds using the Randall-Selitto test. Thermal pain thresholds were measured using the Hargreaves apparatus and a thermal place preference test. Sodium channel Nav1.7 knockout mice show a mechanical deficit in the hairy skin, but not the paw, whilst shaving the abdominal hair abolished this phenotype. Nav1.7, Nav1.8 and Nav1.9 knockout mice show deficits in noxious mechanosensation in the tail, but not the paw. TRPA1 knockout mice, however, have a loss of noxious mechanosensation in the paw but not the tail. Studies of heat and cold sensitivity also show variability depending on the intensity of the stimulus. Deleting Nav1.7, Nav1.8 or Nav1.9 in Nav1.8-positive sensory neurons attenuates responses to slow noxious heat ramps, whilst responses to fast noxious heat ramps are only reduced when Nav1.7 is lost in large diameter sensory neurons. Deleting Nav1.7 from all sensory neurons attenuates responses to noxious cooling but not extreme cold. Finally, circadian rhythms dramatically influence behavioural outcome measures such as von Frey responses, which change by 80% over the day. These observations demonstrate that fully characterising the phenotype of a transgenic mouse strain requires a range of behavioural pain models. Failure to conduct behavioural tests at different anatomical locations, stimulus intensities, and at different points in the circadian cycle may lead to a pain behavioural phenotype being misinterpreted, or missed altogether. PMID:25101983

  15. Pain Management: Post-Amputation Pain

    MedlinePlus

    Pain Management Post-Amputation Pain Volume 8 · Issue 2 · March/April 1998 Text size Larger text Smaller text ... post-op epidural analgesia is being recommended for pain management since it can be very effective. Adequate doses ...

  16. Laser threshold magnetometry

    NASA Astrophysics Data System (ADS)

    Jeske, Jan; Cole, Jared H.; Greentree, Andrew D.

    2016-01-01

    We propose a new type of sensor, which uses diamond containing the optically active nitrogen-vacancy (NV-) centres as a laser medium. The magnetometer can be operated at room-temperature and generates light that can be readily fibre coupled, thereby permitting use in industrial applications and remote sensing. By combining laser pumping with a radio-frequency Rabi-drive field, an external magnetic field changes the fluorescence of the NV- centres. We use this change in fluorescence level to push the laser above threshold, turning it on with an intensity controlled by the external magnetic field, which provides a coherent amplification of the readout signal with very high contrast. This mechanism is qualitatively different from conventional NV--based magnetometers which use fluorescence measurements, based on incoherent photon emission. We term our approach laser threshold magnetometer (LTM). We predict that an NV--based LTM with a volume of 1 mm3 can achieve shot-noise limited dc sensitivity of 1.86 fT /\\sqrt{{{Hz}}} and ac sensitivity of 3.97 fT /\\sqrt{{{Hz}}}.

  17. Coloring geographical threshold graphs

    SciTech Connect

    Bradonjic, Milan; Percus, Allon; Muller, Tobias

    2008-01-01

    We propose a coloring algorithm for sparse random graphs generated by the geographical threshold graph (GTG) model, a generalization of random geometric graphs (RGG). In a GTG, nodes are distributed in a Euclidean space, and edges are assigned according to a threshold function involving the distance between nodes as well as randomly chosen node weights. The motivation for analyzing this model is that many real networks (e.g., wireless networks, the Internet, etc.) need to be studied by using a 'richer' stochastic model (which in this case includes both a distance between nodes and weights on the nodes). Here, we analyze the GTG coloring algorithm together with the graph's clique number, showing formally that in spite of the differences in structure between GTG and RGG, the asymptotic behavior of the chromatic number is identical: {chi}1n 1n n / 1n n (1 + {omicron}(1)). Finally, we consider the leading corrections to this expression, again using the coloring algorithm and clique number to provide bounds on the chromatic number. We show that the gap between the lower and upper bound is within C 1n n / (1n 1n n){sup 2}, and specify the constant C.

  18. Dipole Symmetry Near Threshold

    NASA Astrophysics Data System (ADS)

    Gai, Moshe

    2004-04-01

    In celebrating Iachello's 60th birthday we underline many seminal contributions for the study of the degrees of freddom relevant for the structure of nuclei and other hadrons. A dipole degree of freedom, well described by the spectrum generating algebra U(4) and the Vibron Model, is a most natural concept in molecular physics. It has been suggested by Iachello with much debate, to be most important for understanding the low lying structure of nuclei and other hadrons. After its first observation in 18O it was also shown to be relevant for the structure of heavy nuclei (e.g. 218Ra). Much like the Ar-benzene molecule, it is shown that molecular configurations are important near threshold as exhibited by states with a large halo and strong electric dipole transitions. The cluster-molecular Sum Rule derived by Alhassid, Gai and Bertsch (AGB) is shown to be a very useful model independent tool for examining such dipole molecular structure near thereshold. Accordingly, the dipole strength observed in the halo nuclei such as 6He, 11Li, 11Be,17O, as well as the N=82 isotones is concentrated around threshold and it exhausts a large fraction (close to 100%) of the AGB sum rule, but a small fraction (a few percent) of the TRK sum rule. This is suggested as an evidence for a new soft dipole Vibron like oscillations in nuclei.

  19. Mechanical Data for Use in Damage Tolerance Analyses

    NASA Technical Reports Server (NTRS)

    Forth, Scott C.; James, Mark A.; Newman, John A.; Everett, Richard A., Jr.; Johnston, William M., Jr.

    2004-01-01

    This report describes the results of a research program to determine the damage tolerance properties of metallic propeller materials. Three alloys were selected for investigation: 2025-T6 Aluminum, D6AC Steel and 4340 Steel. Mechanical response, fatigue (S-N) and fatigue crack growth rate data are presented for all of the alloys. The main conclusions that can be drawn from this study are as follows. The damage tolerant design of a propeller system will require a complete understanding of the fatigue crack growth threshold. There exists no experimental procedure to reliably develop the fatigue crack growth threshold data that is needed for damage tolerant design methods. Significant research will be required to fully understand the fatigue crack growth threshold. The development of alternative precracking methods, evaluating the effect of specimen configuration and attempting to identify micromechanical issues are simply the first steps to understanding the mechanics of the threshold.

  20. [Physiotherapy and physical therapy in pain management].

    PubMed

    Egan, M; Seeger, D; Schöps, P

    2015-10-01

    Patients attend physiotherapy and physical therapy (PT) due to pain problems and/or functional impairments. Although the main focus for therapists has traditionally been physical examination and treatment of tissue structures and biomechanics, over the last few decades a growing body of research has highlighted the importance of central nervous system processing and psychosocial contributors to pain perception. Treatment with PT aims to reduce disability and suffering by reducing pain and increasing tolerance to movement. In Germany, pain management conducted by physiotherapists is currently undergoing major changes. Firstly, PT education is transitioning from a vocational to a degree level and additionally new concepts for improved multidisciplinary treatment approaches are being developed. However, there still remain substantial differences between therapists working in multidisciplinary pain clinics and those following medical referral in private practices. This article provides information on how national and international impulses have contributed to the development of different concepts of passive therapies and active/functional pain rehabilitation in Germany. In the future PT will need to provide more evidence about efficiency and modes of actions for different treatment options to selectively reason the application to patients with acute, subacute and chronic pain. PMID:26373552

  1. Factors affecting mechanical (nociceptive) thresholds in piglets

    PubMed Central

    Janczak, Andrew M; Ranheim, Birgit; Fosse, Torunn K; Hild, Sophie; Nordgreen, Janicke; Moe, Randi O; Zanella, Adroaldo J

    2012-01-01

    Objective To evaluate the stability and repeatability of measures of mechanical (nociceptive) thresholds in piglets and to examine potentially confounding factors when using a hand held algometer. Study design Descriptive, prospective cohort. Animals Forty-four piglets from four litters, weighing 4.6 ± 1.0 kg (mean ± SD) at 2 weeks of age. Methods Mechanical thresholds were measured twice on each of 2 days during the first and second week of life. Data were analyzed using a repeated measures design to test the effects of behavior prior to testing, sex, week, day within week, and repetition within day. The effect of body weight and the interaction between piglet weight and behaviour were also tested. Piglet was entered into the model as a random effect as an additional test of repeatability. The effect of repeated testing was used to test the stability of measures. Pearson correlations between repeated measures were used to test the repeatability of measures. Variance component analysis was used to describe the variability in the data. Results Variance component analysis indicated that piglet explained only 17% of the variance in the data. All variables in the model (behaviour prior to testing, sex, week, day within week, repetition within day, body weight, the interaction between body weight and behaviour, piglet identity) except sex had a significant effect (p < 0.04 for all). Correlations between repeated measures increased from the first to the second week. Conclusions and Clinical relevance Repeatability was acceptable only during the second week of testing and measures changed with repeated testing and increased with increasing piglet weight, indicating that time (age) and animal body weight should be taken into account when measuring mechanical (nociceptive) thresholds in piglets. Mechanical (nociceptive) thresholds can be used both for testing the efficacy of anaesthetics and analgesics, and for assessing hyperalgesia in chronic pain states in research and clinical settings. PMID:22709378

  2. Tetrodotoxin suppresses thermal hyperalgesia and mechanical allodynia in a rat full thickness thermal injury pain model.

    PubMed

    Salas, Margaux M; McIntyre, Matthew K; Petz, Lawrence N; Korz, Walter; Wong, Donald; Clifford, John L

    2015-10-21

    Burn injuries have been identified as the primary cause of injury in 5% of U.S. military personnel evacuated from Operations Iraqi Freedom and Enduring Freedom. Severe burn-associated pain is typically treated with opioids such as fentanyl, morphine, and methadone. Side effects of opioids include respiratory depression, cardiac depression, decrease in motor and cognitive function, as well as the development of hyperalgesia, tolerance and dependence. These effects have led us to search for novel analgesics for the treatment of burn-associated pain in wounded combat service members. Tetrodotoxin (TTX) is a selective voltage-gated sodium channel blocker currently in clinical trials as an analgesic. A phase 3 clinical trial for cancer-related pain has been completed and phase 3 clinical trials on chemotherapy-induced neuropathic pain are planned. It has also been shown in mice to inhibit the development of chemotherapy-induced neuropathic pain. TTX was originally identified as a neurotoxin in marine animals but has now been shown to be safe in humans at therapeutic doses. The antinociceptive effects of TTX are thought to be due to inhibition of Na(+) ion influx required for initiation and conduction of nociceptive impulses. One TTX sensitive sodium channel, Nav1.7, has been shown to be essential in lowering the heat pain threshold after burn injuries. To date, the analgesic effect of TTX has not been tested in burn-associated pain. Male Sprague-Dawley rats were subjected to a full thickness thermal injury on the right hind paw. TTX (8 μg/kg) was administered once a day systemically by subcutaneous injection beginning 3 days post thermal injury and continued through 7 days post thermal injury. Thermal hyperalgesia and mechanical allodynia were assessed 60 and 120 min post injection on each day of TTX treatment. TTX significantly reduced thermal hyperalgesia at all days tested and had a less robust, but statistically significant suppressive effect on mechanical allodynia. These results suggest that systemic TTX may be an effective, rapidly acting analgesic for battlefield burn injuries and has the potential for replacing or reducing the need for opioid analgesics. PMID:26424077

  3. Managing Chemotherapy Side Effects: Pain

    MedlinePlus

    N ational C ancer I nstitute Managing Chemotherapy Side Effects Pain It’s important to treat pain. If you ... help to pay for pain medicine. Managing Chemotherapy Side Effects: Pain Keep track of the pain. Each day, ...

  4. Napping Reverses Increased Pain Sensitivity Due to Sleep Restriction

    PubMed Central

    Faraut, Brice; Léger, Damien; Medkour, Terkia; Dubois, Alexandre; Bayon, Virginie; Chennaoui, Mounir; Perrot, Serge

    2015-01-01

    Study Objective To investigate pain sensitivity after sleep restriction and the restorative effect of napping. Design A strictly controlled randomized crossover study with continuous polysomnography monitoring was performed. Setting Laboratory-based study. Participants 11 healthy male volunteers. Interventions Volunteers attended two three-day sessions: “sleep restriction” alone and “sleep restriction and nap”. Each session involved a baseline night of normal sleep, a night of sleep deprivation and a night of free recovery sleep. Participants were allowed to sleep only from 02:00 to 04:00 during the sleep deprivation night. During the “sleep restriction and nap” session, volunteers took two 30-minute naps, one in the morning and one in the afternoon. Measurements and Results Quantitative sensory testing was performed with heat, cold and pressure, at 10:00 and 16:00, on three areas: the supraspinatus, lower back and thigh. After sleep restriction, quantitative sensory testing revealed differential changes in pain stimuli thresholds, but not in thermal threshold detection: lower back heat pain threshold decreased, pressure pain threshold increased in the supraspinatus area and no change was observed for the thigh. Napping restored responses to heat pain stimuli in the lower back and to pressure stimuli in the supraspinatus area. Conclusions Sleep restriction induces different types of hypersensitivity to pain stimuli in different body areas, consistent with multilevel mechanisms, these changes being reversed by napping. The napping restorative effect on pain thresholds result principally from effects on pain mechanisms, since it was independent of vigilance status. PMID:25723495

  5. [Perioperative analgesia for opioid tolerant patients].

    PubMed

    Lerchl-Wanie, G; Angster, R

    2010-07-01

    In this review article the special anesthesiological problems of opioid tolerance and surgical interventions will be presented. These affect patients with a long-term opioid therapy of chronic pain, addicts with long-term substitution therapy and addicts with current or previous heroin addiction ("clean"). For all patient groups a guarantee of continuous and adequate analgesia (avoidance of fear and increasing patient compliance), exploiting suitable regional anesthesia or regional analgesia procedures when possible, and prevention of a physical opioid withdrawal syndrome have utmost priority. The necessary optimization of perioperative pain therapy only succeeds when based on a thorough preoperative examination of the clinical history which subtly inquires into the drug taking habits with respect to opioids and associated medications. Systemic and/or regional analgesia procedures are possible. Regional procedures are more effective for analgesia. Systemic analgesia procedures do not basically differ from those routinely used for patients without opioid tolerance. However, higher doses of opioids are necessary as well as individual titration according to needs. Special conditions apply to patients previously addicted to opioids (clean) when they are to be operated on. Non-opioids are sufficiently effective for low level pain and opiates can be avoided. Opioid therapy with inclusion of a non-opioid is necessary following major operations or for severe postoperative pain, even as i.v. patient-controlled analgesia (i.v. PCA) if needed. For these patients a relapse to addiction can be provoked by insufficient administration of analgesics, not by pain management including opioids. PMID:20625693

  6. Oscillatory Threshold Logic

    PubMed Central

    Borresen, Jon; Lynch, Stephen

    2012-01-01

    In the 1940s, the first generation of modern computers used vacuum tube oscillators as their principle components, however, with the development of the transistor, such oscillator based computers quickly became obsolete. As the demand for faster and lower power computers continues, transistors are themselves approaching their theoretical limit and emerging technologies must eventually supersede them. With the development of optical oscillators and Josephson junction technology, we are again presented with the possibility of using oscillators as the basic components of computers, and it is possible that the next generation of computers will be composed almost entirely of oscillatory devices. Here, we demonstrate how coupled threshold oscillators may be used to perform binary logic in a manner entirely consistent with modern computer architectures. We describe a variety of computational circuitry and demonstrate working oscillator models of both computation and memory. PMID:23173034

  7. Crossing the Petawatt threshold

    SciTech Connect

    Perry, M.

    1996-12-01

    A revolutionary new laser called the Petawatt, developed by Lawrence Livermore researchers after an intensive three-year development effort, has produced more than 1,000 trillion ({open_quotes}peta{close_quotes}) watts of power, a world record. By crossing the petawatt threshold, the extraordinarily powerful laser heralds a new age in laser research. Lasers that provide a petawatt of power or more in a picosecond may make it possible to achieve fusion using significantly less energy than currently envisioned, through a novel Livermore concept called {open_quotes}fast ignition.{close_quotes} The petawatt laser will also enable researchers to study the fundamental properties of matter, thereby aiding the Department of Energy`s Stockpile Stewardship efforts and opening entirely new physical regimes to study. The technology developed for the Petawatt has also provided several spinoff technologies, including a new approach to laser material processing.

  8. Thai perspectives on pain.

    PubMed

    Mongkhonthawornchai, Siriporn; Sangchart, Bumpenchit; Sornboon, Ariya; Chantarasiri, Jongkolnee

    2013-09-01

    This qualitative research aimed to study the meaning, the characteristics, and the dimensions of pain from a Thai point of view. It was conducted under the research project on the development of the quality of pain management for people in the hospital. The subjects were 62 patients, experiencing pain and receiving treatment in 4 hospitals in northeast Thailand. Data were analyzed through content analysis. The findings included: 1) concept from experience of pain, perceived pain as suffering physically and psychologically, 2) different characteristics between acute and chronic pain, 3) four levels of pain intensity: mild, moderate, high and severe, 4) pain effects on four dimensions: physical, psychological, behavioral and societal (family-social-economy), 5) two factors related to pain: alleviating factor and predisposing factor, and 6) pain management relies on beliefs, culture and religion i.e. good deeds in Buddhism affected six dimensions: physical, psychological, social, spiritual, treatment seeking and asking health personnel for help. The results of the present study revealed the influence of culture beliefs on the meaning of pain, pain characteristics, and the effects of pain as well as pain management in terms of cultural contexts. The findings may be implemented for the development of pain assessment and the model development of pain management more appropriately according to cultural contexts. PMID:24386747

  9. Hispanic Inpatient Pain Intensity.

    PubMed

    McDonald, Deborah Dillon; Ambrose, Margaret; Morey, Barbara

    2015-11-01

    Hispanic adults experience significant pain, but little is known about their pain during hospitalization. The purpose of this research was to describe Hispanic inpatients' pain intensity and compare their pain intensity with that of non-Hispanic patients. A post hoc descriptive design was used to examine 1,466 Hispanic inpatients' medical records (63.2% English speakers) and 12,977 non-Hispanic inpatients' medical records from one hospital for 2012. Mean documented pain intensity was mild for both Hispanic and non-Hispanic inpatients. Pain intensity was greater for English-speaking Hispanic patients than Spanish speakers. The odds of being documented with moderate or greater pain intensity decreased 30% for Spanish-speaking patients. Greater pain intensity documented for English-speaking Hispanic inpatients suggests underreporting of pain intensity by Spanish-speaking patients. Practitioners should use interpreter services when assessing and treating pain with patients who speak languages different from the practitioners' language(s). PMID:24958761

  10. [Tramadol in the treatment of pain].

    PubMed

    Curkovi?, B

    2000-01-01

    Tramadol hydrochloride is a centrally-acting, synthetic analgesic with a dual mechanism of action-weak opioid and monoaminergic effects. Tramadol is a racemic mixture and its mechanism of action via opioid and noradrenergic/serotonergic mechanisms is related to the independent effects of its two enantiomers. Interestingly, the enantiomers act synergistically to achieve better antinociceptive effect without enhancing side effects, moreover, lowering respiratory depression and tolerance/dependence. In several post-marketing surveillance studies tramadol is showed as effective as codeine, penthazocine, pethidine and morphine with good tolerability. Tramadol might be analgesic of choice for a wide variety of painful conditions. PMID:11552611

  11. Integrated Approach for Pain Management in Parkinson Disease.

    PubMed

    Geroin, Christian; Gandolfi, Marialuisa; Bruno, Veronica; Smania, Nicola; Tinazzi, Michele

    2016-04-01

    Pain, one of the most frequent nonmotor symptoms of Parkinson disease (PD), is recognized as an important component of the illness that adversely affects patient quality of life. The aims of this review are to summarize the current knowledge on the clinical assessment and to provide a detailed overview of the evidence-based pharmacologic and nonpharmacologic approaches to treating pain. Results of a literature search include studies investigating pain/sensory abnormalities in PD. The effects of levodopa administration, deep brain stimulation (DBS), pallidotomy, spinal cord stimulation, rehabilitation, and complementary/alternative medicine are reviewed critically. PD patients have altered pain and sensory thresholds; levodopa and DBS improve pain and change sensory abnormalities toward normal levels through antinociceptive and/or modulatory effects that remain unknown. A wide range of nonpharmacologic approaches require further investigation. A multidisciplinary approach is fundamental in managing pain syndromes in PD. PMID:26879763

  12. Pain and sex hormones: a review of current understanding.

    PubMed

    Maurer, Adrian J; Lissounov, Alexei; Knezevic, Ivana; Candido, Kenneth D; Knezevic, Nebojsa Nick

    2016-05-01

    Multiple epidemiologic studies have demonstrated an increased prevalence for women in several chronic pain disorders. Clinical and experimental investigations have consistently demonstrated sex-specific differences in pain sensitivity and pain threshold. Even though the underlying mechanisms responsible for these differences have not yet been elucidated, the logical possibility of gonadal hormone influence on nociceptive processing has garnered recent attention. In this review, we evaluated the complex literature regarding gonadal hormones and their influence on pain perception. We reviewed the numerous functions of gonadal hormones, discussed the influence of these hormones on several common chronic pain syndromes (migraine, tension and cluster headaches, fibromyalgia, temporomandibular syndrome, rheumatoid arthritis and back pain, among others), and have attempted to draw conclusions from the available data. PMID:26983893

  13. Testing the gate-control theory of pain in man

    PubMed Central

    Nathan, P. W.; Rudge, P.

    1974-01-01

    According to the gate-control theory of pain, the electrical stimulation of large nerve fibres should stop the pain induced when only C fibres are active. This kind of pain was induced by pressure, repeated pinprick, cold and heat in the ischaemic limb. The peripheral nerves were electrically stimulated in the same way as is done by patients treating their chronic pain by electrical stimulation. There was no change in the quantity nor the quality of the C fibre pain. In other experiments, electrical stimulation of the peripheral nerves induced no change in pain threshold to a heat stimulus when only C fibres were conducting, nor when the whole spectrum of fibres were conducting. Although many experiments have been reported that are consistent with the gate-control theory, the experiments reported here, and others mentioned, are inconsistent with the theory. PMID:4449001

  14. Do burn injuries during infancy affect pain and sensory sensitivity in later childhood?

    PubMed

    Wollgarten-Hadamek, Iris; Hohmeister, Johanna; Demirakça, Sueha; Zohsel, Katrin; Flor, Herta; Hermann, Christiane

    2009-01-01

    Studies in animals and humans suggest that neonatal and early infant pain or stress experiences can induce long-term alterations in somatosensory and pain processing. We studied pain and sensory sensitivity in school-aged children (9-16 years) who had suffered moderate (N=24) or severe (N=24) burn injuries in infancy (6-24 months of age) and 24 controls. Quantitative sensory testing entailing detection and pain thresholds for thermal and mechanical stimuli and perceptual sensitization to tonic heat and repetitive mechanical stimuli was performed. Two testing sites (thenar, trigeminal region), both not affected by the burn injury, were used to determine whether there are global changes in pain sensitivity. The result pattern suggests a differential impact of burn severity. Compared to controls, moderately burned children showed significantly higher mechanical detection thresholds (thenar) and significantly lower mechanical pain thresholds and significantly greater perceptual sensitization to repetitive mechanical stimuli (both testing sites). No significant alterations were observed for thermal stimuli. In contrast, severely burned children showed, compared to controls, primarily alterations in thermal pain sensitivity (elevated pain thresholds at both testing sites, significantly greater perceptual sensitization at the thenar). In these children, mechanical pain sensitivity and detection thresholds were not consistently altered. This differential pattern of altered sensory and pain sensitivity may reflect differences in experienced stress, pain and analgesic treatment between moderately and severely burned children. Most importantly, our findings suggest that early traumatic and painful injuries, such as burns, can induce global, long-term alterations in sensory and pain processing. PMID:19095356

  15. Inflammatory pain in experimental burns in man.

    PubMed

    Pedersen, J L

    2000-06-01

    Human experimental pain models are important tools in pain research. The primary aims of pain research in normal man is 1) to provide insight in pain mechanisms, 2) to provide a rational basis for clinical trials of pain relieving interventions, and 3) to confirm the anti-nociceptive effects demonstrated in animal models. Most often clinical pain is due to tissue damage leading to acute inflammation and hyperalgesia, but only few human pain models have examined pain responses in injured tissues. Therefore, models with controlled and reversible tissue trauma are needed. The human burn model is an example of such a model, and several groups have performed studies of analgesics and pain mechanisms based on the model. The thesis aims to provide a critical review of the human burn model as a tool in pain research, and to give suggestions for development of the model and future research. The pain and inflammatory responses to superficial thermal burns in skin have been studied in healthy volunteers. Burns have the potential for releasing most of the inflammatory and chemical mediators that produce sensitisation and excitation of nociceptors, and the intense nociceptive input during injury produces sensitisation of central neurones in the nociceptive pathway. Pain and hyperalgesia have been evaluated in the model by thermal, various mechanical, and electrical stimuli. The different methods of pain assessments are discussed to clarify the underlying neural mechanisms, the questions that can be addressed by the measurements, and the discrepancies in results between studies. Inflammation has been evaluated in the model by skin erythema intensity, area of flare, and blister formation. The major determinant of skin erythema intensity is the amount of blood in the most superficial part of the dermis, and burn-induced erythema may be primarily due to congestion of capillary loops and postcapillary venules. The area of flare may be used to evaluate the efferent function of heat-sensitive A delta- and C-fibre nociceptors, whereas blisters may be used to assess edema formation and the degree of injury. Hyperalgesia is induced immediately by the burns and lasts about 24 h dependent on the intensity of the heat stimulus. The burns heal without sequela. A study of the reproducibility of pain assessments in the burn model has shown that measures based on repeated measurements were significantly more reproducible than measures based on single time points. Further, within-day reproducibility was better than between-day reproducibility. Within-day variations of heat pain responses to 45 degrees C and 47 degrees C were smaller than that of pain responses to 43 degrees C, suggesting that assessments using clearly painful stimuli may be more reproducible. A methodological study also demonstrated that habituation to experimental pain developed as the study proceeded. Habituation is common in experimental pain models, and dividing analgesics and placebo evenly between the study days is one way of eliminating the effects of habituation. The use of simultaneous right-left comparisons represents the ideal design when possible. The burn model has been a valuable tool in the study of pain mechanisms. Hyperalgesia to heat in the burned area (primary hyperalgesia) is mediated by sensitisation of C-fibre mechano-heat-sensitive (CMH) nociceptors and A delta-fibre mechano-heat-sensitive (AMH) nociceptors of type I in hairy skin. A contribution from sensitised CNS neurones is likely, and the sensitisation of nociceptors is confined to the injured area. The presence of hyperalgesia to heat in normal skin surrounding a burn (secondary hyperalgesia) has been demonstrated in several studies, but the pain threshold may be unaltered. The mechanisms for primary hyperalgesia to mechanical stimuli may be both peripheral and central, but the importance of peripheral mechanisms is unclear and central mechanisms may account for mechanical hyperalgesia in both the primary and th PMID:10913984

  16. A human experimental model of episodic pain.

    PubMed

    Petrini, Laura; Hennings, Kristian; Li, Xi; Negro, Francesco; Arendt-Nielsen, Lars

    2014-12-01

    An experimental model of daily episodic pain was developed to investigate peripheral sensitization and cortical reorganization in healthy individuals. Two experiments (A and B) were conducted. Experiments A and B consisted of one and five consecutive days, respectively, in which the participants were subjected to 45 min of intense painful cutaneous electrical stimulation (episodic pain session), using a stimulus paradigm that in animals has been shown to induce long-term potentiation. These electrical stimulations produced a verbal pain rating of approximately 85 on a 0-100 verbal rating scale (VRS). Physiological (blood flow and axon flare reflex), psychophysical (perception threshold and verbal pain ratings) and electrophysiological (128 channels recorded somatosensory evoked potential (SEP)) measurements were recorded. The stimulation evoked a visible axon flare reflex and caused significantly increased cutaneous blood flow around the site of the stimulation. Axon flare reflex and blood flow reached a plateau on day one in all the subjects and no significant changes between the days were observed. The results showed that the effect of the electrical stimulations changed over the five days; pain potentiation was induced on the first day (significant increase in the verbal pain ratings during the 45 min stimulation) but not on any of the subsequent days. After five days of subsequent pain induction, the global field power showed a significant reduction in P2 amplitude in the late stage (200-370 ms, in the central-parietal area). In conclusion, the results suggest that in healthy individuals this model of episodic pain produces a rapid adaptation after day one and that generates significant SEP changes at day five. PMID:25128903

  17. A Systematic Comparison Between Subjects with No Pain and Pain Associated with Active Myofascial Trigger Points

    PubMed Central

    Gerber, Lynn H.; Sikdar, Siddhartha; Armstrong, Katee; Diao, Guoqing; Heimur, Juliana; Kopecky, John; Turo, Diego; Otto, Paul; Gebreab, Tadesse; Shah, Jay

    2013-01-01

    Objective To determine whether standard evaluations of pain distinguish subjects with no pain from those with myofascial pain syndromes (MPS) and active trigger points (MTrPs); and to assess whether self-reports of mood, function and health-related quality of life differ between these groups. Design Prospective, descriptive study. Setting University Patients Adults with and without neck pain Methods We evaluated adults with MPS and active (painful) MTrPs and those without pain. Subjects in the “Active” (‘A’) group had at least one active MTrP with spontaneous pain which was persistent, lasted more than 3 months and had characteristic pain on palpation. Subjects in the “No pain” (‘Np’) group had no spontaneous pain. However, some had discomfort on MTrP palpation (latent MTrP) while others in the Np group had no discomfort on palpation of nodules or had no nodules. Outcome Measures Each participant underwent range of motion (ROM) measurement, 10-point manual muscle test, and manual and algometric palpation. The latter determined the pain/pressure threshold using an algometer of 4 pre-determined anatomical sites along the upper trapezius. Participants rated pain using a verbal analogue scale (0–10); completed the Brief Pain Inventory and Oswestry Disability Scale (ODS), which included a sleep sub-scale; Short Form 36(SF36) and the Profile of Mood States (POMS). Results here were 24 in the ‘A’ group (mean 36 yrs, 16 women) and 26 in the ‘Np’ group (mean 26 yrs, 12 women). Subjects in group ‘A’ differed from ‘Np’ in number of latent MTrPs (p=.0062); asymmetrical cervical ROM (p=.01 side bending and p=.002 rotation); in all pain reports (p<.0001); algometry (p<.03); POMS (p<.038); SF36 (p<.01) and ODS (p<.0001). Conclusion A systematic musculoskeletal evaluation of people with MPS reliably distinguishes them from subjects with no pain. The two groups are significantly different in their physical findings and self-reports of pain, sleep disturbance, disability, health status and mood. These findings support the view that a “local” pain syndrome has significant associations with mood, health-related quality of life and function.. PMID:23810811

  18. Evidence of Increased Non-Verbal Behavioral Signs of Pain in Adults with Neurodevelopmental Disorders and Chronic Self-Injury

    ERIC Educational Resources Information Center

    Symons, Frank J.; Harper, Vicki N.; McGrath, Patrick J.; Breau, Lynn M.; Bodfish, James W.

    2009-01-01

    The role of pain in relation to self-injurious behavior (SIB) among individuals with intellectual disabilities is not well understood. Some models of SIB are based on altered endogenous opioid system activity which could result in elevated pain thresholds. In this study, non-verbal behavioral signs indicative of pain as measured by the…

  19. Evidence of Increased Non-Verbal Behavioral Signs of Pain in Adults with Neurodevelopmental Disorders and Chronic Self-Injury

    ERIC Educational Resources Information Center

    Symons, Frank J.; Harper, Vicki N.; McGrath, Patrick J.; Breau, Lynn M.; Bodfish, James W.

    2009-01-01

    The role of pain in relation to self-injurious behavior (SIB) among individuals with intellectual disabilities is not well understood. Some models of SIB are based on altered endogenous opioid system activity which could result in elevated pain thresholds. In this study, non-verbal behavioral signs indicative of pain as measured by the

  20. Comparison of acceptance and distraction strategies in coping with experimentally induced pain

    PubMed Central

    Moore, Hazel; Stewart, Ian; Barnes-Holmes, Dermot; Barnes-Holmes, Yvonne; McGuire, Brian E

    2015-01-01

    Background This study compared an acceptance-based strategy with a control-based strategy (distraction) in terms of the ability of participants to tolerate a painful stimulus, across two experiments. In addition, participants were either actively encouraged, or not, to link pain tolerance with pursuit of valued goals to examine the impact of pursuing a personally meaningful goal or value on the extent to which pain will be tolerated. Methods Participants in experiment 1 (n=41) and experiment 2 (n=52) were equally assigned to acceptance or distraction protocols. Further, half the participants in each group generated examples from their own lives in which they had pursued a valued objective, while the other half did not. In experiment 2, the values focus was enhanced to examine the impact on pain tolerance. Results There were no significant differences overall between the acceptance and distraction groups on pain tolerance in either experiment. However, in experiment 2, individuals classified as accepting in terms of general coping style and who were assigned to the acceptance strategy showed significantly better pain tolerance than accepting individuals who were in the distraction condition. Across both experiments, those with strong goal-driven values in both protocols were more tolerant of pain. Participants appeared to have more difficulty adhering to acceptance than to distraction as a strategy. Conclusion Acceptance may be associated with better tolerance of pain, but may also be more difficult to operationalize than distraction in experimental studies. Matching coping style and coping strategy may be most effective, and enhancement of goal-driven values may assist in pain coping. PMID:25834464

  1. Probabilistic Threshold Criterion

    SciTech Connect

    Gresshoff, M; Hrousis, C A

    2010-03-09

    The Probabilistic Shock Threshold Criterion (PSTC) Project at LLNL develops phenomenological criteria for estimating safety or performance margin on high explosive (HE) initiation in the shock initiation regime, creating tools for safety assessment and design of initiation systems and HE trains in general. Until recently, there has been little foundation for probabilistic assessment of HE initiation scenarios. This work attempts to use probabilistic information that is available from both historic and ongoing tests to develop a basis for such assessment. Current PSTC approaches start with the functional form of the James Initiation Criterion as a backbone, and generalize to include varying areas of initiation and provide a probabilistic response based on test data for 1.8 g/cc (Ultrafine) 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and LX-17 (92.5% TATB, 7.5% Kel-F 800 binder). Application of the PSTC methodology is presented investigating the safety and performance of a flying plate detonator and the margin of an Ultrafine TATB booster initiating LX-17.

  2. Hairpin Vortex Regeneration Threshold

    NASA Astrophysics Data System (ADS)

    Sabatino, Daniel; Maharjan, Rijan

    2015-11-01

    A free surface water channel is used to study hairpin vortex formation created by fluid injection through a narrow slot into a laminar boundary layer. Particle image velocimetry is used to calculate the circulation of the primary hairpin vortex head which is found to monotonically decrease in strength with downstream distance. When a secondary hairpin vortex is formed upstream of the primary vortex, the circulation strength of the head is comparable to the strength of the primary head at the time of regeneration. However, the legs of the primary vortex strengthen up to the moment the secondary hairpin is generated. Although the peak circulation in the legs is not directly correlated to the strength of the original elongated ring vortex, when the circulation is scaled with the injection momentum ratio it is linearly related to scaled injection time. It is proposed that the injection momentum ratio and nondimensionalized injection time based on the wall normal penetration time can be used to identify threshold conditions which produce a secondary vortex. Supported by the National Science Foundation under Grant CBET- 1040236.

  3. Learning foraging thresholds for lizards

    SciTech Connect

    Goldberg, L.A.; Hart, W.E.; Wilson, D.B.

    1996-01-12

    This work gives a proof of convergence for a randomized learning algorithm that describes how anoles (lizards found in the Carribean) learn a foraging threshold distance. This model assumes that an anole will pursue a prey if and only if it is within this threshold of the anole`s perch. This learning algorithm was proposed by the biologist Roughgarden and his colleagues. They experimentally confirmed that this algorithm quickly converges to the foraging threshold that is predicted by optimal foraging theory our analysis provides an analytic confirmation that the learning algorithm converses to this optimal foraging threshold with high probability.

  4. Arthritis and pain. Current approaches in the treatment of arthritic pain

    PubMed Central

    Kidd, Bruce L; Langford, Richard M; Wodehouse, Theresa

    2007-01-01

    Current evidence suggests that although persistent arthritic pain is initiated and maintained by articular pathology, it is also heavily influenced by a range of other factors. Strategies for treating arthritic pain are therefore different from those adopted for acute pain. Although published guidelines offer general assistance, the complexity of underlying mechanisms requires that measures designed to relieve pain must take into account individual biological, psychological and societal factors. It follows that a combination of both pharmacological and non-pharmacological approaches offers the best opportunity for therapeutic success, although determining the effectiveness of such complex interventions remains difficult. Pharmacological therapy is often prolonged, and safety and tolerability issues become as important as efficacy over time. PMID:17572915

  5. The problem of pain.

    PubMed

    Nicholson, Keith; Martelli, Michael F

    2004-01-01

    Pain problems, especially posttraumatic headache, are very common following head trauma. Pain may be the most significant problem, more disabling than any brain or other injuries, and interfering with aspects of cognition or other function. However, posttraumatic headache and most other chronic posttraumatic pain problems remain poorly understood. This article reviews fundamental issues that should be considered in understanding the nature of chronic pain including the distinction between acute and chronic pain; neurobiological distinctions between the lateral and medial pain system; nociceptive versus neuropathic or other central pain; sensitization effects; the widely accepted view of chronic pain as a multidimensional subjective experience involving sensory, motivational-affective and cognitive-behavioral components; the problem of mind-body dualism; the role of psychosocial factors in the onset, maintenance, exacerbation or severity of pain; plus issues of response bias and malingering. PMID:14732827

  6. Pain and the ethics of pain management.

    PubMed

    Edwards, R B

    1984-01-01

    In this article I clarify the concepts of 'pain', 'suffering', 'pains of body', 'pains of soul'. I explore the relevance of an ethic to the clinical setting which gives patients a strong prima facie right to freedom from unnecessary and unwanted pain and which places upon medical professionals two concomitant moral obligations to patients. First, there is the duty not to inflict pain and suffering beyond what is necessary for effective diagnosis, treatment and research. Next, there is the duty to do all that can be done to relieve all the pain and suffering which can be alleviated. I develop in some detail that individuality of pain sensitivity must be taken into account in fulfilling these obligations. I explore the issue of the relevance of informed consent and the right to refuse treatment to the matter of pain relief. And I raise the question of what conditions, if any, should override the right to refuse treatment where pain relief is of paramount concern. PMID:6710192

  7. Pain. Part 1: Introduction to pain.

    PubMed

    Renton, Tara

    2015-03-01

    This series of papers aims to provide the dental and medical teams with an update in pain, both acute and chronic orofacial conditions, relevant to dentistry and medicine. Pain is the most common symptom for patients presenting to their dentist, and is increasingly commonly presenting to doctors as well, in general practice and A & E departments. Most of the dental team take for granted their knowledge and ability to manage acute dental pain. However, the education and preparation in managing patients with chronic pain conditions remains poor in many medical and dental schools. Conversely, medics are better educated and exposed to chronic pain during their undergraduate education, however, with regards to orofacial pain education, exposure is diminishing due to decreased exposure to dentistry, ENT, otolaryngology, OMFS and oral surgery. Thus many clinical teams remain disadvantaged when diagnosing and managing orofacial pain. Clinical Relevance: Significant advances that have been made in understanding the pain mechanisms are not to be overlooked and have a huge impact on how we manage patients in pain. PMID:26058224

  8. Image analysis using threshold reduction

    NASA Astrophysics Data System (ADS)

    Bloomberg, Dan S.

    1991-07-01

    A class of shift-variant reduction operations is introduced, that is useful for performing efficient and controllable shape and texture transformations between resolution levels. In their most general form, the operations proceed in three steps: (a) convolve a binary image with a kernel of arbitrary size; (b) threshold the result; (c) subsample to produce the reduced image. Taking a binary structuring element for the kernel, the threshold convolution on a binary image is equivalent to a rank order filter, and the full reduction operation is a threshold reduction. Threshold reductions that use convolution filters and subsample tiles of equal size are optimized by combining the three operations, using only logical raster operations and producing threshold convolution values only at the sampling points. For 2x reduction, the four possible threshold values (1, 2, 3, and 4) refer to the minimum number of ON pixels within each 2x2 tile for which a pixel in the reduced image will be ON. Algorithms for boolean raster operations are given for 2x, 3x, and 4x threshold reduction, and lookup tables that efficiently implement column raster operations are provided. Threshold reduction rates of 2.5x107 pixel/second can be achieved with a Sun SparcStation2TM . A maskforming image analysis cycle of threshold reduction, augmented by morphology and followed by replicative expansion to full resolution, is described, and some general properties of the cycle are derived. A simple application of threshold reduction to document image analysis, the extraction of halftone regions from scanned images that also contain text and line graphics, is illustrated. A sequence of 2x reductions with first low and then high thresholds is used to create a reduced image consisting of a mask over the halftone regions. In this way, the extraction occurs as a natural consequence of the reductions.

  9. [Botulinum toxins for pain].

    PubMed

    Soinila, Seppo; Haanp, Maija

    2011-01-01

    We review the evidence of botulinum toxins in the treatment of pain. Main indications of botulinum toxin treatment, dystonia and spasticity, involve pain. Increasing evidence suggests direct analgesic effects of botulinum. Botulinum inhibits release of pain mediators (substance P, CGRP, excitatory amino acids, ATP, noradrenaline). Clinical trials have consistently shown analgesic effect of botulinum toxin in post-stroke shoulder pain, bladder dysfunction, chronic migraine, neuropathic pain, bruxism and lateral epicondylitis. Other pain conditions have been studied with yet uncertain results. It seems that the number of patients who would benefit from botulinum toxin treatment will increase considerably in the future. PMID:22238920

  10. Pediatric pain management.

    PubMed

    Lederhaas, G

    1997-01-01

    It is now recognized that from the newborn period onwards, children are capable of experiencing pain. This includes the premature infant. The challenge for healthcare providers is to incorporate methods of pain assessment and treatment into their daily practices. The child's understanding of pain closely follows the cognitive and behavioral model developed by Jean Piaget. Based on these developmental stages, pain assessment measures have been developed. Pharmacologic advances have accompanied this improved understanding of infant, child, and adolescent psychology. While acute pain accounts for the majority of children's experiences, recurrent/chronic pain states do occur (e.g. sickle cell related and neuropathic) and can be effectively treated. PMID:9037997

  11. [Muscle-skeletal pain].

    PubMed

    Vygonskaya, M V; Filatova, E G

    2016-01-01

    The paper is devoted to the most complicated aspects of low back pain. The differences between specific and nonspecific low back pain using the "red flags" system is highlighted. The authors consider the causes of pain chronification (the "yellow flags" system) and the necessity of using a biopsychosocial model. Main pathogenetic mechanisms of chronic muscle/skeletal pain are considered and the possible involvement of several mechanism in the pathogenesis of chronic pain as well as the use of complex therapy is discussed. The high efficacy and safety of ketorolac in treatment of nonspecific muscle/skeletal pain is demonstrated. PMID:27042717

  12. Epidural injections for back pain

    MedlinePlus

    ... Society Low Back Pain Guideline Panel. Interventional therapies, surgery, and interdisciplinary rehabilitation for low back pain: an evidence-based clinical practice guideline from the American Pain Society. ...

  13. Chiropractic care for back pain

    MedlinePlus

    ... Society Low Back Pain Guideline Panel. Interventional therapies, surgery, and interdisciplinary rehabilitation for low back pain: an evidence-based clinical practice guideline from the American Pain Society. ...

  14. Managing your chronic back pain

    MedlinePlus

    ... Society Low Back Pain Guideline Panel. Interventional therapies, surgery, and interdisciplinary rehabilitation for low back pain: an evidence-based clinical practice guideline from the American Pain Society. ...

  15. Ecohydrology on the Threshold?

    NASA Astrophysics Data System (ADS)

    Wainwright, John

    2013-04-01

    This presentation suggests that there are three major limitations to the development of ecohydrology as a coherent disciplinary area. One of the principal controls and feedbacks on patterns of plants and water in the environment is the form of the landscape and landscape-forming processes. Yet (eco)geomorphology is typically overlooked as a topic for ecohydrological investigation. Thus, the process domains used to explain patterns is typically overly restricted. As surface change controls the connectivity of other process, this restriction is significant. However, even when surface change is incorporated, there is often an emphasis on subdisciplinary areas, so that the investigation of patterns across process domains is not carried out in a holistic way. For example, studies of the feedbacks of vegetation on flow resistance are carried out significantly differently when considering wind and water flows (and indeed differently for water flows on hillslopes compared to in channels). Human action is the most important global control on ecohydrology, either from a top-down perspective through climate change, or from a bottom-up perspective through land use and land-use change. The actions of people on ecohydrological and ecogeomorphic processes, though, are typically considered in a static way. Techniques of agent-based modelling are being developed to overcome this limitation, but there need to be parallel developments in field techniques to address the data requirements and empirical underpinnings of such approaches. I argue that to cross the threshold into becoming a more mature discipline ecohydrology/ecogeomorphology needs to take on board the limitations of representations of process, pattern and people. Using examples from studies of land degradation in drylands, as well as from more temperate settings, I will suggest how progress may start to be made.

  16. Dorsal Horn Circuits for Persistent Mechanical Pain.

    PubMed

    Peirs, Cedric; Williams, Sean-Paul G; Zhao, Xinyi; Walsh, Claire E; Gedeon, Jeremy Y; Cagle, Natalie E; Goldring, Adam C; Hioki, Hiroyuki; Liu, Zheng; Marell, Paulina S; Seal, Rebecca P

    2015-08-19

    Persistent mechanical hypersensitivity that occurs in the setting of injury or disease remains a major clinical problem largely because the underlying neural circuitry is still not known. Here we report the functional identification of key components of the elusive dorsal horn circuit for mechanical allodynia. We show that the transient expression of VGLUT3 by a discrete population of neurons in the deep dorsal horn is required for mechanical pain and that activation of the cells in the adult conveys mechanical hypersensitivity. The cells, which receive direct low threshold input, point to a novel location for circuit initiation. Subsequent analysis of c-Fos reveals the circuit extends dorsally to nociceptive lamina I projection neurons, and includes lamina II calretinin neurons, which we show also convey mechanical allodynia. Lastly, using inflammatory and neuropathic pain models, we show that multiple microcircuits in the dorsal horn encode this form of pain. PMID:26291162

  17. Painful Spastic Hip Dislocation: Proximal Femoral Resection

    PubMed Central

    Albiñana, Javier; Gonzalez-Moran, Gaspar

    2002-01-01

    The dislocated hip in a non-ambulatory child with spastic paresis tends to be a painful interference to sleep, sitting upright, and perineal care. Proximal femoral resection-interposition arthroplasty is one method of treatment for this condition. We reviewed eight hips, two bilateral cases, with a mean follow-up of 30 months. Clinical improvement was observed in all except one case, with respect to pain relief and sitting tolerance. Some proximal migration was observed in three cases, despite routine post-operative skeletal traction in all cases and careful soft tissue interposition. One case showed significant heterotopic ossification which restricted prolonged sitting. This patient needed some occasional medication for pain. PMID:12180614

  18. Pain and Associated Substance Use among Opioid Dependent Individuals Seeking Office-Based Treatment with Buprenorphine-Naloxone: A Needs Assessment Study

    PubMed Central

    Barry, Declan T.; Savant, Jonathan D.; Beitel, Mark; Cutter, Christopher J.; Moore, Brent A.; Schottenfeld, Richard S.; Fiellin, David A.

    2012-01-01

    Background and Objectives A paucity of studies has examined the pain experiences of opioid dependent individuals seeking office-based buprenorphine-naloxone treatment (BNT). We set out to examine, among those seeking BNT: (a) the prevalence of pain types (i.e., recent pain, chronic pain), (b) the characteristics of pain (intensity, frequency, duration, interference, location, and genesis), and (c) substance use to alleviate pain. Methods We surveyed 244 consecutive individuals seeking office-based buprenorphine-naloxone treatment (BNT) for opioid dependence about physical pain and associated substance use. Results Thirty-six percent of respondents reported chronic pain (CP) (i.e., pain lasting at least 3 months) and 36% reported “some pain” (SP) (i.e., past week pain not meeting the threshold for CP). In comparison to SP respondents, those with CP were, on average, older; reported greater current pain intensity, pain frequency, typical pain duration, typical pain intensity, and typical pain interference; were more likely to report shoulder or pelvis and less likely to report stomach or arms as their most bothersome pain location; and were more likely to report accident or nerve damage and less likely to report opioid withdrawal as the genesis of their pain. Both pain subgroups reported similarly high rates of past-week substance use to alleviate pain. Conclusions and Scientific Significance The high rates of pain and self-reported substance use to manage pain suggest the importance of assessing and addressing pain in BNT patients. PMID:23617861

  19. Threshold Concepts and Information Literacy

    ERIC Educational Resources Information Center

    Townsend, Lori; Brunetti, Korey; Hofer, Amy R.

    2011-01-01

    What do we teach when we teach information literacy in higher education? This paper describes a pedagogical approach to information literacy that helps instructors focus content around transformative learning thresholds. The threshold concept framework holds promise for librarians because it grounds the instructor in the big ideas and underlying…

  20. Threshold Hypothesis: Fact or Artifact?

    ERIC Educational Resources Information Center

    Karwowski, Maciej; Gralewski, Jacek

    2013-01-01

    The threshold hypothesis (TH) assumes the existence of complex relations between creative abilities and intelligence: linear associations below 120 points of IQ and weaker or lack of associations above the threshold. However, diverse results have been obtained over the last six decades--some confirmed the hypothesis and some rejected it. In this

  1. The Nature of Psychological Thresholds

    ERIC Educational Resources Information Center

    Rouder, Jeffrey N.; Morey, Richard D.

    2009-01-01

    Following G. T. Fechner (1966), thresholds have been conceptualized as the amount of intensity needed to transition between mental states, such as between a states of unconsciousness and consciousness. With the advent of the theory of signal detection, however, discrete-state theory and the corresponding notion of threshold have been discounted.…

  2. Threshold Hypothesis: Fact or Artifact?

    ERIC Educational Resources Information Center

    Karwowski, Maciej; Gralewski, Jacek

    2013-01-01

    The threshold hypothesis (TH) assumes the existence of complex relations between creative abilities and intelligence: linear associations below 120 points of IQ and weaker or lack of associations above the threshold. However, diverse results have been obtained over the last six decades--some confirmed the hypothesis and some rejected it. In this…

  3. Fatigue Crack Growth Threshold Testing of Metallic Rotorcraft Materials

    NASA Technical Reports Server (NTRS)

    Newman, John A.; James, Mark A.; Johnson, William M.; Le, Dy D.

    2008-01-01

    Results are presented for a program to determine the near-threshold fatigue crack growth behavior appropriate for metallic rotorcraft alloys. Four alloys, all commonly used in the manufacture of rotorcraft, were selected for study: Aluminum alloy 7050, 4340 steel, AZ91E Magnesium, and Titanium alloy Ti-6Al-4V (beta-STOA). The Federal Aviation Administration (FAA) sponsored this research to advance efforts to incorporate damage tolerance design and analysis as requirements for rotorcraft certification. Rotorcraft components are subjected to high cycle fatigue and are typically subjected to higher stresses and more stress cycles per flight hour than fixed-wing aircraft components. Fatigue lives of rotorcraft components are generally spent initiating small fatigue cracks that propagate slowly under near-threshold cracktip loading conditions. For these components, the fatigue life is very sensitive to the near-threshold characteristics of the material.

  4. Case Report: Neuropathic pain in a patient with congenital insensitivity to pain

    PubMed Central

    Wheeler, Daniel W.; Lee, Michael C.H.; Harrison, E. Katherine; Menon, David K.; Woods, C. Geoffrey

    2015-01-01

    We report a unique case of a woman with Channelopathy-associated Insensitivity to Pain (CIP) Syndrome, who developed features of neuropathic pain after sustaining pelvic fractures and an epidural hematoma that impinged on the right fifth lumbar (L5) nerve root. Her pelvic injuries were sustained during painless labor, which culminated in a Cesarean section. She had been diagnosed with CIP as child, which was later confirmed when she was found to have null mutations of the SCN9A gene that encodes the voltage-gated sodium channel Nav1.7. She now complains of troubling continuous buzzing in both legs and a vice-like squeezing in the pelvis on walking. Quantitative sensory testing showed that sensory thresholds to mechanical stimulation of the dorsum of both feet had increased more than 10-fold on both sides compared with tests performed before her pregnancy. These findings fulfill the diagnostic criteria for neuropathic pain. Notably, she mostly only experiences the negative symptoms (such as numbness and tingling, but also electric shocks), and she has not reported sharp or burning sensations, although the value of verbal descriptors is somewhat limited in a person who has never felt pain before. However, her case strongly suggests that at least some of the symptoms of neuropathic pain can persist despite the absence of the Nav1.7 channel. Pain is a subjective experience and this case sheds light on the transmission of neuropathic pain in humans that cannot be learned from knockout mice. PMID:26676151

  5. Diabetic neuropathic pain: a role for testosterone metabolites.

    PubMed

    Calabrese, Donato; Giatti, Silvia; Romano, Simone; Porretta-Serapiglia, Carla; Bianchi, Roberto; Milanese, Marco; Bonanno, Giambattista; Caruso, Donatella; Viviani, Barbara; Gardoni, Fabrizio; Garcia-Segura, Luis Miguel; Melcangi, Roberto Cosimo

    2014-04-01

    Diabetic neuropathy is associated with neuropathic pain in about 50% of diabetic subjects. Clinical management of neuropathic pain is complex and so far unsatisfactory. In this study, we analyzed the effects of the testosterone metabolites, dihydrotestosterone (DHT), and 3α-diol, on nociceptive and allodynia thresholds and on molecular and functional parameters related to pain modulation in the dorsal horns of the spinal cord and in the dorsal root ganglia of rats rendered diabetic by streptozotocin injection. Furthermore, the levels of DHT and 3α-diol were analyzed in the spinal cord. Diabetes resulted in a significant decrease in DHT levels in the spinal cord that was reverted by DHT or 3α-diol treatments. In addition, 3α-diol treatment resulted in a significant increase in 3α-diol in the spinal cord compared with control values. Both steroids showed analgesic properties on diabetic neuropathic pain, affecting different pain parameters and possibly by different mechanisms of action. Indeed, DHT counteracted the effect of diabetes on the mechanical nociceptive threshold, pre- and post-synaptic components, glutamate release, astrocyte immunoreactivity, and expression of interleukin-1β (IL1β), while 3α-diol was effective on tactile allodynia threshold, glutamate release, astrocyte immunoreactivity and the expression of substance P, toll-like receptor 4, tumor necrosis factor-α, transforming growth factor β-1, IL1β, and translocator protein. These results indicate that testosterone metabolites are potential agents for the treatment of diabetic neuropathic pain. PMID:24424289

  6. Phytotherapy for pain relief.

    PubMed

    Zareba, Grazyna

    2009-06-01

    Pain is considered the third most common healthcare problem disabling more individuals than heart disease and cancer together. Although pharmacological pain management offers a significant relief in several pain-related diseases, many patients turn to its supplementation with complementary and alternative medicine. Botanicals used in pain therapy can contribute to restoring the quality of life to a patient and may effect and enhance conventional pain management. Herbal analgesic use in several pain-related diseases such as rheumatologic diseases, back pain, cancer, diabetic peripheral neuropathy and migraine will be discussed. In addition, this review describes botanicals with known analgesic activity for which randomized, placebo-controlled, double-blind trials assessing their efficacy in different pain-related diseases have been published and which have been recently evaluated in many systematic reviews with well-described methodology. PMID:19649334

  7. Pain in Blood Cancers

    PubMed Central

    Niscola, Pasquale; Tendas, Andrea; Scaramucci, Laura; Giovannini, Marco; De Sanctis, Vitaliana

    2011-01-01

    Patients with blood-related cancers (BRC) suffer from a substantial symptom burden, including several pain syndromes sustained by different causes and pathogenetic mechanisms. So, with regard to pain, a multifaceted clinical scenario may be observed in this setting. Indeed, pain may be correlated to disease itself, to disease-associated complications, to iatrogenic causes or may be due to unrelated clinical conditions. A close diagnostic procedure for the assessment of the underlying causes of the pain and of its pathogenetic mechanisms may direct the treatment approach which should be based on a multidisciplinary management and requires the integration of etiology-targeted interventions and painkilling drugs. The World Health Organization's three-step analgesic ladder for cancer pain relief can provide adequate pain control using oral drugs in most patients with BRC on pain, although more complex interventions may be necessary for many difficult-to-treat pain syndromes which are not infrequently encountered in this setting. PMID:22346041

  8. Hepatitis C: Managing Pain

    MedlinePlus

    ... Living with Hepatitis » Managing Pain: Entire Lesson Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... the hepatitis C is worsening. Pain associated with hepatitis C Some patients with hepatitis C feel discomfort ...

  9. Diet and Pain

    MedlinePlus

    ... 12 By Emily McCloud, RD Rheumatoid Arthritis: Lifestyle Management Diet and Pain Many people who suffer from ... and Pain Information Back to Rheumatoid Arthritis: Lifestyle Management Print Page Email Page Add Page I want ...

  10. Neuropathic pain in leprosy.

    PubMed

    Haanpää, Maija; Lockwood, Diana N J; Hietaharju, Aki

    2004-03-01

    Chronic neuropathic pain in treated leprosy has received scant attention. In this article the concept, clinical features and diagnosis of neuropathic pain are reviewed. The possible pathophysiological mechanisms, treatment challenges and research needs in this area are discussed. PMID:15072122

  11. Pain in cancer survivors

    PubMed Central

    Ramirez, Juan D; Farquhar-Smith, Paul

    2014-01-01

    Cancer and its treatment exert a heavy psychological and physical toll. Of the myriad symptoms which result, pain is common, encountered in between 30% and 60% of cancer survivors. Pain in cancer survivors is a major and growing problem, impeding the recovery and rehabilitation of patients who have beaten cancer and negatively impacting on cancer patients’ quality of life, work prospects and mental health. Persistent pain in cancer survivors remains challenging to treat successfully. Pain can arise both due to the underlying disease and the various treatments the patient has been subjected to. Chemotherapy causes painful chemotherapy-induced peripheral neuropathy (CIPN), radiotherapy can produce late effect radiation toxicity and surgery may lead to the development of persistent post-surgical pain syndromes. This review explores a selection of the common causes of persistent pain in cancer survivors, detailing our current understanding of the pathophysiology and outlining both the clinical manifestations of individual pain states and the treatment options available. PMID:26516548

  12. Block That Pain!

    MedlinePlus

    ... turn Javascript on. New NIH Research Points to Childbirth and Surgical Pain Relief For those who suffer ... promise. That is especially so for pain from childbirth and surgical procedures. The NIH animal study used ...

  13. INSOMNIA IN CHRONIC DISABLING MUSCULOSKELETAL PAIN DISORDERS IS INDEPENDENT OF PAIN AND DEPRESSION

    PubMed Central

    Asih, Sali; Neblett, Randy; Mayer, Tom G.; Brede, Emily; Gatchel, Robert J.

    2014-01-01

    BACKGROUND CONTEXT Insomnia is frequently experienced by patients suffering from chronic musculoskeletal disorders, but is often seen as simply a symptom of pain or depression, and not as an independent disorder. Compared to those who experience only chronic pain, patients with both chronic pain and insomnia report higher pain intensity, more depressive symptoms, and greater distress. However, insomnia has not yet been systematically studied in a chronic musculoskeletal pain with disability population. PURPOSES This study assessed the prevalence and severity of patient-reported insomnia, as well as the relationship among insomnia, pain intensity, and depressive symptoms, in a chronic musculoskeletal pain with disability population. STUDY DESIGN/SETTING A retrospective study of prospectively captured data. PATIENT SAMPLE A consecutive cohort of 326 chronic musculoskeletal pain with disability patients (85% with spinal injuries) entered a functional restoration treatment program. All patients signed a consent form to participate in this protocol. OUTCOME MEASURES Insomnia was assessed with the Insomnia Severity Index (ISI), a validated patient-report measure of insomnia symptoms. Four patient groups were formed: No Clinically Significant Insomnia (score 0–7); Sub-Threshold Insomnia (score 8–14); Moderate Clinical Insomnia (score 15–21); and Severe Clinical Insomnia (score 22–28). Three patterns of sleep disturbance were also evaluated: Early, Middle, and Late Insomnia. Additional validated psychosocial patient-report data were collected, including the Pain Visual Analog Scale (PVAS), the Beck Depression Inventory (BDI), and the Pain Disability Questionnaire (PDQ). METHODS Patients completed a standard psychosocial assessment battery upon admission to the functional restoration program. The program included a quantitatively-directed exercise process in conjunction with a multimodal disability management approach. The four insomnia groups were compared on demographic and psychosocial variables. The shared variances among insomnia, depression, and pain were determined by partial correlational analyses. The writing of this article was supported in part by Grant 1K05 MH 71892 from NIH, focusing on evidence-based assessment and treatment approaches to musculoskeletal pain and the monitoring of valid outcomes. None of the authors involved in this study had a conflict of interest. RESULTS The presence of No Clinically Significant Insomnia, Sub-threshold Insomnia, Moderate Clinical Insomnia and Severe Clinical Insomnia was found in 5.5%, 21.2%, 39.6%, and 33.7% of the cohort, respectively. More than 70% of patients reported moderate to severe insomnia symptoms, which is a considerably higher prevalence than found in most patient cohorts studied previously. A step-wise pattern was found, in which Severe Clinical Insomnia patients reported the highest pain, the most severe depressive symptoms, and the greatest disability. The Severe Clinical Insomnia patients also reported a higher number of sleep disturbance types (Early, Middle, and Late insomnia) than the other 3 groups. In fact, 62.9% of them reported all 3 disturbance types. Although correlations were found between insomnia and depressive symptoms, and between insomnia and pain, the shared variances were small (12.9% and 3.6%, respectively), indicating that depression and pain are separate constructs from insomnia. CONCLUSION This research indicates that insomnia is a significant and pervasive problem in a chronic musculoskeletal pain with disability population. Most importantly, although insomnia has traditionally been assumed to be simply a symptom of pain or depression, the findings of the present study reveal that it is a construct relatively independent from both pain and depression. Specific insomnia assessment and treatment is therefore recommended for this chronic musculoskeletal pain with disability population. PMID:24333458

  14. Effects of heel support banding using an elastic band on chronic pain at the achilles tendon in a mountaineer.

    PubMed

    Yoo, Won-Gyu

    2016-01-01

    [Purpose] This study developed heel support banding (HSB) using an elastic band for flexible heel support and investigated its effect on chronic Achilles tendon pain of a mountaineer. [Subject] A 40-year-old male mountaineer with chronic Achilles tendon pain [Methods] Ankle dorsiflexion and plantar flexion angles, VISA-A questionnaire, load-induced pain, total pain threshold and tenderness at 3 kg of pressure were measured before and after applying HSB. [Results] After one month of applying HSB, the dorsiflexion and plantar flexion angles increased; the VISA-A questionnaire score increased; the load-induced pain assessment score decreased; the pain threshold increased; and tenderness at 3 kg decreased. [Conclusion] These results indicate that HSB use improves ankle range of motion, decreases pressure and pain, and could provide a new approach for effective intervention and management of chronic Achilles tendon pain. PMID:26957781

  15. Effects of heel support banding using an elastic band on chronic pain at the achilles tendon in a mountaineer

    PubMed Central

    Yoo, Won-Gyu

    2016-01-01

    [Purpose] This study developed heel support banding (HSB) using an elastic band for flexible heel support and investigated its effect on chronic Achilles tendon pain of a mountaineer. [Subject] A 40-year-old male mountaineer with chronic Achilles tendon pain [Methods] Ankle dorsiflexion and plantar flexion angles, VISA-A questionnaire, load-induced pain, total pain threshold and tenderness at 3 kg of pressure were measured before and after applying HSB. [Results] After one month of applying HSB, the dorsiflexion and plantar flexion angles increased; the VISA-A questionnaire score increased; the load-induced pain assessment score decreased; the pain threshold increased; and tenderness at 3 kg decreased. [Conclusion] These results indicate that HSB use improves ankle range of motion, decreases pressure and pain, and could provide a new approach for effective intervention and management of chronic Achilles tendon pain. PMID:26957781

  16. Racial differences in the physical and psychosocial health among black and white women with chronic pain.

    PubMed Central

    Ndao-Brumblay, S. Khady; Green, Carmen R.

    2005-01-01

    Gender-based differences in pain epidemiology, pain threshold, attitudes toward pain management, coping styles and social roles are well described, yet little is known about the chronic pain experience in women or the role race plays. A retrospective analysis of self-reported data using a secondary clinical database was performed to elucidate the relationship between race and pain severity, depression, physical disability, posttraumatic stress disorder (PTSD) as well as affective distress in women with chronic pain. White (n=1,088) and black (n=104) adult women were compared based on their responses to the McGill Pain Questionnaire, Beck Depression Inventory, Pain Disability Index, Posttraumatic Chronic Pain Test and items from the West-Haven Yale Multidisciplinary Pain Inventory. After accounting for sociodemographic, medical, psychological and physical confounders, there was no significant race effect for pain severity or affective distress. However, black women with chronic pain experience more physical impairments than white women with chronic pain (beta = 4.622; p<0.005). Except for the family/home responsibilities, similar differences were found on all PDI subscales. We also found that disability mediates the race-depression relationship such that black women are comparatively more vulnerable to depression as a result of higher disability. Due to the economic, social and emotional impact that disability has on women with chronic pain and their families, these findings have significant implications for chronic pain research as well as its management in black women. PMID:16353658

  17. Technology for chronic pain.

    PubMed

    Zhang, Suyi; Seymour, Ben

    2014-09-22

    Technology developed for chronic pain management has been fast evolving and offers new stand-alone prospects for the diagnosis and treatment of pain, rather than simply addressing the limitations of pharmacology-based approaches. There are two central challenges to be tackled: developing objective measures that capture the subjectivity of pain experience, and providing technology-based interventions that offer new approaches for pain management. Here we highlight recent developments that hold promise in addressing both of these challenges. PMID:25247372

  18. Differential changes in gingival somatosensory sensitivity after painful electrical tooth stimulation.

    PubMed

    Baad-Hansen, Lene; Lu, Shengyi; Kemppainen, Pentti; List, Thomas; Zhang, Zhenting; Svensson, Peter

    2015-04-01

    We aimed to evaluate the effect of painful tooth stimulation on gingival somatosensory sensitivity of healthy volunteers in a randomized, controlled design. Thirteen healthy volunteers (six women, seven men; 28.4 ± 5.0 years) were included for two experimental sessions of electrical tooth stimulation: painful tooth stimulation and tooth stimulation below the sensory threshold (control). Eight of the human subjects participated in a third session without tooth stimulation. In all sessions, the somatosensory sensitivity of the gingiva adjacent to the stimulated tooth was evaluated with a standardized battery of quantitative sensory tests (QST) before, immediately after and 30 min after tooth stimulation. Painful tooth stimulation evoked significant decreases in warmth and heat pain thresholds (P < 0.001) as well as pressure pain thresholds (increased sensitivity) (P = 0.024) and increases in mechanical detection thresholds (decreased sensitivity) (P < 0.050). Similar thermal threshold changes (P < 0.019) but no mechanical changes were found after tooth stimulation below the sensory threshold (P > 0.086). No QST changes were detected in the session without tooth stimulation (P > 0.060). In conclusion, modest increased gingival sensitivity to warmth, painful heat and pressure stimuli as well as desensitization to non-painful mechanical stimulation were demonstrated after tooth stimulation. This suggests involvement of competing heterotopic facilitatory and inhibitory mechanisms. Furthermore, stimulation below the sensory threshold induced similar thermal sensitization suggesting the possibility of activation of axon-reflex-like mechanisms even at intensities below the perception threshold. These findings may have implications for interpretation of somatosensory results in patients with chronic intraoral pain. PMID:25567087

  19. Neuropathic pain syndrome.

    PubMed

    Jones, James

    2015-06-01

    Questions from patients about pain conditions and analgesic pharmacotherapy and responses from authors are presented to help educate patients and make them more effective self-advocates. This article provides information to patients regarding the treatment of neuropathic pain syndrome. It narrates how a doctor might explain neuropathic pain to a patient and particularly discusses the use of anticonvulsants. PMID:26095492

  20. Post-operative pain.

    PubMed

    2016-04-20

    Essential facts According to the National Institute for Health and Care Excellence, about 60% of people who have surgery will experience severe pain post-operatively. Controlling this pain minimises patients' discomfort and distress, contributes to recovery and rehabilitation, and may prevent patients progressing from acute to chronic pain. PMID:27097185

  1. Pediatric Procedural Pain

    ERIC Educational Resources Information Center

    Blount, Ronald L.; Piira, Tiina; Cohen, Lindsey L.; Cheng, Patricia S.

    2006-01-01

    This article reviews the various settings in which infants, children, and adolescents experience pain during acute medical procedures and issues related to referral of children to pain management teams. In addition, self-report, reports by others, physiological monitoring, and direct observation methods of assessment of pain and related constructs…

  2. Pediatric Procedural Pain

    ERIC Educational Resources Information Center

    Blount, Ronald L.; Piira, Tiina; Cohen, Lindsey L.; Cheng, Patricia S.

    2006-01-01

    This article reviews the various settings in which infants, children, and adolescents experience pain during acute medical procedures and issues related to referral of children to pain management teams. In addition, self-report, reports by others, physiological monitoring, and direct observation methods of assessment of pain and related constructs

  3. Pain and pain control in children.

    PubMed

    Schechter, N L

    1985-05-01

    Focused research on pain and pain control in children has developed primarily in the last 10 years and even now is woefully inadequate in relation to the magnitude of the problem. The available research, inferences from the adult literature, and anecdotal information all indicate the elusive nature of pain. Pain is not solely a fixed neurophysiologic response to a noxious stimulus but a product of the interaction of many variables such as age, cognitive set, personality, ethnic background, and emotional state. These factors exert a tremendous influence on the suffering which surrounds the pain message. Technology exists at present to eliminate or substantially reduce pain in almost all cases. There remains, however, a tendency, which is even more pronounced with respect to children, to underestimate or ignore pain. In an overall approach to pain in children, the following points should be considered: A high index of suspicion is necessary to determine if children are experiencing pain since they may have difficulty verbalizing their discomfort. In infants, physiologic variables should be considered (increased heart rate, palmar sweating, increased respiratory rate), and in preschoolers, time should be taken to ascertain that the child actually understands the word "pain" if it is used in questioning them. Some method of continuous monitoring, such as a visual analogue scan, should be considered as part of the treatment plan. Adequate analgesia should be provided. The appropriate dose should be administered at the appropriate pharmacokinetic time. Too little medication may cause obsessive attention to medication-related issues. Too much medication may cause sedation and lack of mental clarity, which is often anxiety-producing for both the parents and the child. The usefulness of p.r.n. medication has been seriously questioned and a time-contingent as opposed to pain-contingent strategy should be applied. Fears of addiction are generally unwarranted. Adjunctive medication may increase the value of offered narcotics and counteract some of their side effects. Although this monograph has focused more attention on pharmacologic than on nonpharmacologic approaches to pain, this is merely a reflection of available data and not necessarily of relative importance. The importance of distraction from pain by nursing, medical, or child life personnel using play techniques cannot be overestimated. Every attempt should be made to relax the child by using creative strategies. Preparation of the child for procedures is often helpful as some of the fear of the unknown is eliminated.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2861066

  4. Bayesian estimation of dose thresholds

    NASA Technical Reports Server (NTRS)

    Groer, P. G.; Carnes, B. A.

    2003-01-01

    An example is described of Bayesian estimation of radiation absorbed dose thresholds (subsequently simply referred to as dose thresholds) using a specific parametric model applied to a data set on mice exposed to 60Co gamma rays and fission neutrons. A Weibull based relative risk model with a dose threshold parameter was used to analyse, as an example, lung cancer mortality and determine the posterior density for the threshold dose after single exposures to 60Co gamma rays or fission neutrons from the JANUS reactor at Argonne National Laboratory. The data consisted of survival, censoring times and cause of death information for male B6CF1 unexposed and exposed mice. The 60Co gamma whole-body doses for the two exposed groups were 0.86 and 1.37 Gy. The neutron whole-body doses were 0.19 and 0.38 Gy. Marginal posterior densities for the dose thresholds for neutron and gamma radiation were calculated with numerical integration and found to have quite different shapes. The density of the threshold for 60Co is unimodal with a mode at about 0.50 Gy. The threshold density for fission neutrons declines monotonically from a maximum value at zero with increasing doses. The posterior densities for all other parameters were similar for the two radiation types.

  5. Bayesian estimation of dose thresholds.

    PubMed

    Groer, P G; Carnes, B A

    2003-01-01

    An example is described of Bayesian estimation of radiation absorbed dose thresholds (subsequently simply referred to as dose thresholds) using a specific parametric model applied to a data set on mice exposed to 60Co gamma rays and fission neutrons. A Weibull based relative risk model with a dose threshold parameter was used to analyse, as an example, lung cancer mortality and determine the posterior density for the threshold dose after single exposures to 60Co gamma rays or fission neutrons from the JANUS reactor at Argonne National Laboratory. The data consisted of survival, censoring times and cause of death information for male B6CF1 unexposed and exposed mice. The 60Co gamma whole-body doses for the two exposed groups were 0.86 and 1.37 Gy. The neutron whole-body doses were 0.19 and 0.38 Gy. Marginal posterior densities for the dose thresholds for neutron and gamma radiation were calculated with numerical integration and found to have quite different shapes. The density of the threshold for 60Co is unimodal with a mode at about 0.50 Gy. The threshold density for fission neutrons declines monotonically from a maximum value at zero with increasing doses. The posterior densities for all other parameters were similar for the two radiation types. PMID:12593429

  6. The effects of exposure to repeated minor pain during the neonatal period on formalin pain behaviour and thermal withdrawal latencies.

    PubMed

    Johnston, C Celeste; Walker, Claire-Dominique

    2003-01-01

    Preterm infants undergoing untreated, repeated painful procedures as part of their early experience are more likely to behave differently to pain as they mature than infants who were born at term and did not experience excessive exogenous pain. The neonatal rat model was used to investigate the short- and long-term effects of repeated pain in infancy on later development of pain responses. Newborn rat pups were randomly assigned by litter to be left unhandled (UH), handled by being removed from the dam for 15 min four times daily (H), and being handled and receiving pain from a paw prick with a 26G needle four times daily (P) on postnatal days (PD) 2 through 8 (PD2-PD8). Maternal behaviour and grooming of pups on their return to the nest were recorded at PD6 for H and P pups. At PD15, PD36 and PD65, animals were first tested for latency to thermal stimulation threshold using the Hargreaves test and then for inflammatory pain using the formalin test. Pups in the HP group received significantly more grooming from their mothers (359 s) than pups in the H group (295 s, P<0.0001). When accounting for differences in maternal grooming, a decreased thermal threshold in the P group compared with the H group (6.04 s versus 5.3 s, P<0.05) was found, although the correlations were not significant between maternal grooming and thermal thresholds. No group differences were seen with the formalin test. Interestingly, age was a significant factor in both tests, with younger animals showing fewer pain behaviours regardless of group or maternal grooming of the pup. Sex was significant at one age only in latency to thermal stimulation testing. The results suggest that changes in maternal care may be an important factor mediating the long-term effects of repeated neonatal experiences of pain. PMID:14679416

  7. Orthodoxy, recalcitrance and in-between: describing variation in seed storage characteristics using threshold responses to water loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tolerance of desiccation is typically described by a threshold or low-water-content-limit to survival. This convention provides fairly good distinction between orthodox and recalcitrant seeds, which show thresholds of less than about 0.07 and greater than about 0.2 g H2O g dw-1, respectively. Thresh...

  8. A longitudinal study of pain, personality, and brain plasticity following peripheral nerve injury.

    PubMed

    Goswami, Ruma; Anastakis, Dimitri J; Katz, Joel; Davis, Karen D

    2016-03-01

    We do not know precisely why pain develops and becomes chronic after peripheral nerve injury (PNI), but it is likely due to biological and psychological factors. Here, we tested the hypotheses that (1) high Pain Catastrophizing Scale (PCS) scores at the time of injury and repair are associated with pain and cold sensitivity after 1-year recovery and (2) insula gray matter changes reflect the course of injury and improvements over time. Ten patients with complete median and/or ulnar nerve transections and surgical repair were tested ∼3 weeks after surgical nerve repair (time 1) and ∼1 year later for 6 of the 10 patients (time 2). Patients and 10 age-/sex-matched healthy controls completed questionnaires that assessed pain (patients) and personality and underwent quantitative sensory testing and 3T MRI to assess cortical thickness. In patients, pain intensity and neuropathic pain correlated with pain catastrophizing. Time 1 pain catastrophizing trended toward predicting cold pain thresholds at time 2, and at time 1 cortical thickness of the right insula was reduced. At time 2, chronic pain was related to the time 1 pain-PCS relationship and cold sensitivity, pain catastrophizing correlated with cold pain threshold, and insula thickness reversed to control levels. This study highlights the interplay between personality, sensory function, and pain in patients following PNI and repair. The PCS-pain association suggests that a focus on affective or negative components of pain could render patients vulnerable to chronic pain. Cold sensitivity and structural insula changes may reflect altered thermosensory or sensorimotor awareness representations. PMID:26588697

  9. Surgical Treatment for Chronic Pelvic Pain

    PubMed Central

    1998-01-01

    The source of chronic pelvic pain may be reproductive organ, urological, musculoskeletal - neurological, gastrointestinal, or myofascial. A psychological component almost always is a factor, whether as an antecedent event or presenting as depression as result of the pain. Surgical interventions for chronic pelvic pain include: 1) resection or vaporization of vulvar/vestibular tissue for human papillion virus (HPV) induced or chronic vulvodynia/vestibulitis; 2) cervical dilation for cervix stenosis; 3) hysteroscopic resection for intracavitary or submucous myomas or intracavitary polyps; 4) myomectomy or myolysis for symptomatic intramural, subserosal or pedunculated myomas; 5) adhesiolysis for peritubular and periovarian adhesions, and enterolysis for bowel adhesions, adhesiolysis for all thick adhesions in areas of pain as well as thin ahesions affecting critical structures such as ovaries and tubes; 6) salpingectomy or neosalpingostomy for symptomatic hydrosalpinx; 7) ovarian treatment for symptomatic ovarian pain; 8) uterosacral nerve vaporization for dysmenorrhea; 9) presacral neurectomy for disabling central pain primarily of uterine but also of bladder origin; 10) resection of endometriosis from all surfaces including removal from bladder and bowel as well as from the rectovaginal septal space. Complete resection of all disease in a debulking operation is essential; 11) appendectomy for symptoms of chronic appendicitis, and chronic right lower quadrant pain; 12) uterine suspension for symptoms of collision dyspareunia, pelvic congestion, severe dysmenorrhea, cul-desac endometriosis; 13) repair of all hernia defects whether sciatic, inguinal, femoral, Spigelian, ventral or incisional; 14) hysterectomy if relief has not been achieved by organ-preserving surgery such as resection of all endometriosis and presacral neurectomy, or the central pain continues to be disabling. Before such a radical step is taken, MRI of the uterus to confirm presence of adenomyosis may be helpful; 15) trigger point injection therapy for myofascial pain and dysfunction in pelvic and abdominal muscles. With application of all currently available laparoscopic modalities, 80% of women with chronic pelvic pain will report a decrease of pain to tolerable levels, a significant average reduction which is maintained in 3-year follow-up. Individual factors contributing to pain cannot be determined, although the frequency of endometriosis dictates that its complete treatment be attempted. The beneficial effect of uterosacral nerve ablation may be as much due to treatment of occult endometriosis in the uterosacral ligaments as to transection of the nerve fibers themselves. The benefit of the presacral neurectomy appears to be definite but strictly limited to midline pain. Appendectomy, herniorraphy, and even hysterectomy are all appropriate therapies for patients with chronic pelvic pain. Even with all laparoscopic procedures employed, fully 20% of patients experience unsatisfactory results. In addition, these patients are often depressed. Whether the pain contributes to the depression or the depression to the pain is irrelevant to them. Selected referrals to an integrated pain center with psychologic assistance together with judicious prescription of antidepressant drugs will likely benefit both women who respond to surgical intervention and those who do not. A maximum surgical effort must be expended to resect all endometriosis, restore normal pelvic anatomy, resect nerve fibers, and treat surgically accessible disease. In addition, it is important to provide patients with chronic pelvic pain sufficient psychologic support to overcome the effects of the condition, and to assist them with underlying psychologic disorders. PMID:9876726

  10. Pain Management for Children during Bone Marrow and Stem Cell Transplantation

    PubMed Central

    Vasquenza, Kelly; Ruble, Kathy; Chen, Allen; Billett, Carol; Kozlowski, Lori; Atwater, Sara; Kost-Byerly, Sabine

    2014-01-01

    Pain management for children during bone marrow and stem cell transplantation is a significant clinical challenge for the health care team. Pain management strategies vary by institution. This paper reports on the use of a pediatric pain management service and patient-and caregiver-controlled analgesia for children undergoing transplant. This 2-year retrospective chart review examined the pain management practices and outcomes of children undergoing bone marrow and stem cell transplants in a large urban teaching hospital during 2008 and 2009. We concluded that patient- and caregiver-controlled analgesia is a well-tolerated modality for pain control during hospitalization for transplantation at this institution. PMID:25267531

  11. Ethnic differences in pain and pain management

    PubMed Central

    Campbell, Claudia M; Edwards, Robert R

    2012-01-01

    SUMMARY Considerable evidence demonstrates substantial ethnic disparities in the prevalence, treatment, progression and outcomes of pain-related conditions. Elucidating the mechanisms underlying these group differences is of crucial importance in reducing and eliminating disparities in the pain experience. Over recent years, accumulating evidence has identified a variety of processes, from neurophysiological factors to structural elements of the healthcare system, that may contribute to shaping individual differences in pain. For example, the experience of pain differentially activates stress-related physiological responses across various ethnic groups, members of different ethnic groups appear to use differing coping strategies in managing pain complaints, providers’ treatment decisions vary as a function of patient ethnicity and pharmacies in predominantly minority neighborhoods are far less likely to stock potent analgesics. These diverse factors, and others may all play a role in facilitating elevated levels of pain-related suffering among individuals from ethnic minority backgrounds. Here, we present a brief, nonexhaustive review of the recent literature and potential physiological and sociocultural mechanisms underlying these ethnic group disparities in pain outcomes. PMID:23687518

  12. Experimentally induced pain perception in men and women in the morning and evening.

    PubMed

    Koltyn, K F; Focht, B C; Ancker, J M; Pasley, J

    1999-01-01

    The literature regarding whether or not there are diurnal differences in pain perception in men and women is equivocal. The purpose of this study was to examine the influence of time of day on experimentally induced pain threshold in men and women. A secondary purpose was to measure selected psychological and physiological responses. Pressure (3000 gm force) was applied to the middle digit of the left forefinger for 2-min with the Forgione-Barber pain stimulator. Twenty-nine volunteers (women = 14; men = 15) completed two randomly assigned sessions between 6.00-8.00 in the AM and PM. Selected psychological variables (STAI,POMS) and physiological variables (BP, HR, TEMP) were assessed before application of the pressure stimulus. Data were analyzed with a 2x2 ANOVA. Results indicated that men had significantly higher (p<.05) systolic blood pressure and pain thresholds than women however, there was not a significant time of day effect for pain threshold. Significant time of day effects (p<.05) were found for systolic blood pressure and tympanic temperature. Heart rate, and tympanic temperature were found to be significantly higher (p<.05) in women in comparison to men. It is concluded that pain threshold did not differ in the AM and PM. Furthermore, men were found to have higher pain thresholds compared to the women. PMID:10395360

  13. Investigation of the paradoxical painful sensation ('illusion of pain') produced by a thermal grill.

    PubMed

    Bouhassira, Didier; Kern, Delphine; Rouaud, Jean; Pelle-Lancien, Emilie; Morain, Françoise

    2005-03-01

    A paradoxical painful sensation can be elicited by the simultaneous application of innocuous warm and cold stimuli to the skin. In the present study, we analyzed the conditions of production of this unique experimental illusion of pain in 52 healthy volunteers (27 men, 25 women). The stimuli were produced by a thermode composed of six bars whose temperature was controlled by Peltier elements. The temperature of alternate (even- and odd-numbered) bars could be controlled independently to produce various patterns of the 'thermal grill'. After measuring the cold and heat pain thresholds, a series of combinations of warm and cold stimuli, whose distance to the thermal pain threshold was at least 4 degrees C, were applied on the palmar surface of the right hand during 30s. After each stimulus, the subjects had to describe and rate their sensations on visual analog scales. Paradoxical painful sensations, mostly described as burning, were reported by all the subjects but three. However, the phenomenon was less frequent in approximately one third of ('low responder') volunteers. The frequency and intensity of such painful sensations were directly related to the magnitude (i.e. 5-25 degrees C) of the difference of the temperature between the warm and cold bars of the grill. The combination of increasingly colder temperature to a given warm temperature induces similar effects as combining increasingly warmer temperature to a given cold temperature. These results suggest that pain can be the result of a simple addition of non-noxious warm and cold signals. PMID:15733641

  14. Psychological Aspects of Chronic Pain

    PubMed Central

    Jacobs, Rosevelt

    1983-01-01

    Since its inception in June 1979, over 500 patients have been treated at the King/Drew Pain Center in Los Angeles. Based upon the treatment and observations of this patient group, this paper describes the psychologic aspects in patients suffering from chronic abdominal pain, low back pain, phantom limb pain, chest pain, and arthritic pain. PMID:6864816

  15. The role of sensitization in musculoskeletal shoulder pain

    PubMed Central

    Borstad, John; Woeste, Christopher

    2015-01-01

    Introduction: Peripheral and central sensitization are neurophysiological processes that can prolong painful conditions. Painful shoulder conditions are often persistent, perhaps due to the presence of sensitization. Method: This manuscript summarizes six studies that have evaluated those with musculoskeletal shoulder pain for the presence of sensitization. Results: All six manuscripts report evidence of peripheral sensitization, while central sensitization was described in five of the studies. The chronicity of symptoms in subjects who were included in the studies is probably influencing this finding. The primary somatosensory test used to assess sensitization in these studies was Pressure Pain Threshold, a test for lowered nociceptive thresholds. Discussion: It appears that peripheral sensitization manifests consistently in those with musculoskeletal shoulder pathology, probably due to the inflammatory processes related to tissue injury. Central sensitization, while not universally present, was reported in a majority of the manuscripts. Because central sensitization is thought to be a key step on the pathway to chronic pain, evidence for its presence in those with shoulder pain is significant. Clinicians should expect the presence of sensitization with shoulder pathology and make appropriate choices about interventions so as not to exacerbate pain. PMID:26443971

  16. Pain perception in female adolescents with borderline personality disorder.

    PubMed

    Ludscher, Petra; von Kalckreuth, Clemens; Parzer, Peter; Kaess, Michael; Resch, Franz; Bohus, Martin; Schmahl, Christian; Brunner, Romuald

    2015-03-01

    Borderline personality disorder (BPD) is a severe and often debilitating psychiatric disorder that begins during adolescence. Core features of BPD are affective dysregulation, dysfunctional self-concepts, and difficulties in social interactive domains. A widely accepted marker for severe emotion dysregulation in adult BPD is decreased pain sensitivity. Until now it is unclear whether this characteristic feature of BPD is already present during adolescence. Thus, this study aims to investigate pain sensitivity in adolescent patients meeting DSM-IV criteria for BPD. 20 female adolescent patients with BPD (mean age 16.4years) and 20 healthy age-matched control participants were investigated. Detection and pain thresholds for thermal stimuli were assessed on both hands. Furthermore, self-rating instruments were used to assess overall psychopathology, dissociation, and depression. We found significantly higher pain thresholds in patients with BPD than in healthy controls. Patients with BPD had higher intensities of depression, overall psychopathology, and dissociative symptoms, but there was no correlation between pain sensitivity and any of these measures of psychopathology. These findings are in line with previous findings in adult BPD patients concerning lower pain sensitivity as compared to healthy controls. This provides support for the idea that disturbed pain processing is not only a consequence of chronic BPD but is already present in early stages of BPD. PMID:25053123

  17. Chronic pain: the burden of disease and treatment innovations.

    PubMed

    Monti, S; Caporali, R

    2015-01-01

    Musculoskeletal conditions are the most frequent cause of chronic pain and affect around 1 in 5 adults in Europe. When chronic pain occurs, it becomes disease itself, with substantial clinical, social and economic impact. Efficacy and tolerability problems are encountered with all therapeutic strategies available to treat musculoskeletal pain. This often limits effective analgesia and patients' long term compliance, with the result that chronic pain is persistently underestimated and undertreated. Tapentadol is a novel, centrally acting analgesic that has been recently commercialized for the treatment of chronic pain. This new molecule, by combining two distinct mechanisms of action, μ-opioid receptor agonism (MOR) and noradrenaline reuptake inhibition (NRI), introduces a new pharmacological class called MOR-NRI. Several studies demonstrated promising results in the management of both nociceptive and neuropathic pain and good tolerability profile, particularly concerning side effects, compared to traditional opioids. This novel analgesic represents a possible therapeutic option also in the rheumatologic field, particularly in the treatment of osteoarthritis and low back pain. PMID:26492961

  18. [Neurorehabilitation for Neuropathic Pain].

    PubMed

    Hozumi, Jun; Osumi, Michihiro; Ogata, Toru; Sumitani, Masahiko

    2015-07-01

    Deafferentation, like as in limb amputation, brachial plexus avulsion injury and spinal cord injury, is usually followed by neuropathic pain. Neuropathic pain is a debilitating condition and it impairs the quality of life profoundly. Based on recent advances in the cognitive neuroscience, we explain intimate relationships among neuropathic pain, reorganization of primary sensory and motor cortices and the sensorimotor integration of the deafferentated limb. From the standpoint of the sensorimotor integration theory for emerging phantom limb pain, we further discuss the analgesic mechanism of neurorehabilitation techniques such as mirror visual feedback treatment and its related neurorobotics advancement for neuropathic pain. PMID:26422941

  19. [Pathophysiology of abdominal pain].

    PubMed

    Curatolo, Michele

    2011-08-01

    Abdominal pain can be induced by stimulation of visceral nociceptors. Activation of nociceptors usually requires previous sensitization by pathological events, such as inflammation, ischemia or acidosis. Although abdominal pain can obviously be caused by pathology of a visceral structure, clinicians frequently observe that such a pathology explains only part of the pain complaints. Occasionally, there is lack of objective signs of visceral lesions. There is clear evidence that pain states are associated with profound changes of the central processing of the sensory input. The main consequences of such alterations for patients are twofold: 1) a central sensitization, i.e. an increased excitability of the central nervous system; 2) an alteration of the endogenous pain modulation, which under normal conditions inhibits the processing of nociceptive signals in the central nervous system. Both phenomena lead to a spread of pain to other body regions and an amplification of the pain perception. The interactions between visceral pathology and alterations of the central pain processes represent an at least partial explanation for the discrepancy between objective signs of peripheral lesions and severity of the symptoms. Today, both central hypersensitivity and alteration in endogenous pain modulation can be measured in clinical practice. This information can be used to provide the patients with an explanatory model for their pain. Furthermore, first data suggest that alterations in central pain processing may represent negative prognostic factors. A better understanding of the individual pathophysiology may allow in the future the development of individual therapeutic strategies. PMID:21796591

  20. Preventing chronic postoperative pain.

    PubMed

    Reddi, D

    2016-01-01

    Chronic postoperative pain is common. Nerve injury and inflammation promote chronic pain, the risk of which is influenced by patient factors, including psychological characteristics. Interventional trials to prevent chronic postoperative pain have been underpowered with inadequate patient follow-up. Ketamine may reduce chronic postoperative pain, although the optimum treatment duration and dose for different operations have yet to be identified. The evidence for gabapentin and pregabalin is encouraging but weak; further work is needed before these drugs can be recommended for the prevention of chronic pain. Regional techniques reduce the rates of chronic pain after thoracotomy and breast cancer surgery. Nerve-sparing surgical techniques may be of benefit, although nerve injury is not necessary or sufficient for chronic pain to develop. PMID:26620149

  1. Common medical pains

    PubMed Central

    Jacobson, Sheila

    2007-01-01

    Pain in infancy and childhood is extremely common. Sources of pain include illness, injury, and medical and dental procedures. Over the past two decades, tremendous progress has been made in the assessment, prevention and treatment of pain. It is important for the paediatric health care provider to be aware of the implications and consequences of pain in childhood. A multitude of interventions are available to reduce or alleviate pain in children of all ages, including neonates. These include behavioural and psychological methods, as well as a host of pharmacological preparations, which are safe and effective when used as indicated. Many complementary and alternative treatments appear to be promising in treating and relieving pain, although further research is required. The present article reviews the most common sources of pain in childhood and infancy, as well as current treatment strategies and options. PMID:19030348

  2. The Pain of Labour

    PubMed Central

    Labor, Simona

    2008-01-01

    Labour is an emotional experience and involves both physiological and psychological mechanisms. The pain of labour is severe but despite this its memory diminishes with time. Labour pain has two components: visceral pain which occurs during the early first stage and the second stage of childbirth, and somatic pain which occurs during the late first stage and the second stage. The pain of labour in the first stage is mediated by T10 to L1 spinal segments, whereas that in the second stage is carried by T12 to L1, and S2 to S4 spinal segments. Pain relief in labour is complex and often challenging without regional analgesia. Effective management of labour pain plays a relatively minor role in a woman's satisfaction with childbirth. PMID:26526404

  3. Pulsed Radiofrequency Application for the Treatment of Pain Secondary to Sacroiliac Joint Metastases.

    PubMed

    Yi, Yu Ri; Lee, Na Rea; Kwon, Young Suk; Jang, Ji Su; Lim, So Young

    2016-01-01

    Sacroiliac (SI) joint pain can result from degeneration, infection, malignancy, and trauma. Patients with metastatic bone pain who do not respond to conventional treatment may need more aggressive neuroinvasive approaches. Recently, pulsed radiofrequency (PRF) neuromodulation has emerged as a promising treatment alternative for refractory cases of SI joint pain. Nevertheless, there is no report on the treatment of pain arising from SI joint metastases with PRF. We are reporting about a 63-year-old woman suffering from buttock pain due to breast cancer metastases in the SI joint. We treated this patient with PRF neuromodulation of the L4-S3 primary dorsal rami and lateral branches using a rotating curved needle technique. The patient tolerated the procedures well, without any complications. She experienced about 70% reduction in pain, and pain relief was sustained for 10 months. This result suggests that PRF neuromodulation is a safe, effective treatment for pain from SI joint metastases. PMID:26839672

  4. Targeting Epigenetic Mechanisms for Chronic Pain: A Valid Approach for the Development of Novel Therapeutics.

    PubMed

    Ligon, Casey O; Moloney, Rachel D; Greenwood-Van Meerveld, Beverley

    2016-04-01

    Chronic pain is a multifaceted and complex condition. Broadly classified into somatic, visceral, or neuropathic pain, it is poorly managed despite its prevalence. Current drugs used for the treatment of chronic pain are limited by tolerance with long-term use, abuse potential, and multiple adverse side effects. The persistent nature of pain suggests that epigenetic machinery may be a critical factor driving chronic pain. In this review, we discuss the latest insights into epigenetic processes, including DNA methylation, histone modifications, and microRNAs, and we describe their involvement in the pathophysiology of chronic pain and whether epigenetic modifications could be applied as future therapeutic targets for chronic pain. We provide evidence from experimental models and translational research in human tissue that have enhanced our understanding of epigenetic processes mediating nociception, and we then speculate on the potential future use of more specific and selective agents that target epigenetic mechanisms to attenuate pain. PMID:26787772

  5. Extenuating Circumstances in Perceptions of Suicide: Disease Diagnosis (AIDS, Cancer), Pain Level, and Life Expectancy.

    ERIC Educational Resources Information Center

    Martin, Stephen K.; Range, Lillian M.

    1991-01-01

    Examined whether illness type, pain level, and life expectancy affected reactions of undergraduates (n=160) toward a terminal illness suicide with Acquired Immune Deficiency Syndrome (AIDS) or cancer. AIDS patients were more stigmatized than cancer patients; suicide was more tolerated if victim was suffering greater pain. (Author/ABL)

  6. Citalopram Treatment of Pediatric Recurrent Abdominal Pain and Comorbid Internalizing Disorders: An Exploratory Study

    ERIC Educational Resources Information Center

    Campo, John V.; Perel, James; Lucas, Amanda; Bridge, Jeff; Ehmann, Mary; Kalas, Catherine; Monk, Kelly; Axelson, David; Birmaher, Boris; Ryan, Neal; Di Lorenzo, Carlo; Brent, David A.

    2004-01-01

    Objective: To assess the potential efficacy, tolerability, and safety of citalopram in the treatment of functional pediatric recurrent abdominal pain and comorbid internalizing disorders. Method: Twenty-five clinically referred children and adolescents with recurrent abdominal pain aged 7 to 18 years, inclusive, participated in a 12-week,…

  7. Immune mediators of chronic pelvic pain syndrome.

    PubMed

    Murphy, Stephen F; Schaeffer, Anthony J; Thumbikat, Praveen

    2014-05-01

    The cause of chronic pelvic pain syndrome (CPPS) has yet to be established. Since the late 1980s, cytokine, chemokine, and immunological classification studies using human samples have focused on identifying biomarkers for CPPS, but no diagnostically beneficial biomarkers have been identified, and these studies have done little to deepen our understanding of the mechanisms underlying chronic prostatic pain. Given the large number of men thought to be affected by this condition and the ineffective nature of current treatments, there is a pressing need to elucidate these mechanisms. Prostatitis types IIIa and IIIb are classified according to the presence of pain without concurrent presence of bacteria; however, it is becoming more evident that, although levels of bacteria are not directly associated with levels of pain, the presence of bacteria might act as the initiating factor that drives primary activation of mast-cell-mediated inflammation in the prostate. Mast cell activation is also known to suppress regulatory T cell (Treg) control of self-tolerance and also activate neural sensitization. This combination of established autoimmunity coupled with peripheral and central neural sensitization can result in the development of multiple symptoms, including pelvic pain and bladder irritation. Identifying these mechanisms as central mediators in CPPS offers new insight into the prospective treatment of the disease. PMID:24686526

  8. Controversies in cancer pain. Medical perspectives.

    PubMed

    Foley, K M

    1989-06-01

    The treatment of pain in the patient with cancer has focused attention on a series of controversial issues involving medical, social, and moral factors. The medical factors include a lack of knowledge on the part of health care professionals regarding the rational use of opioid drugs. This is coupled with real limitations in the general understanding of the mechanisms of pain and its treatment using pharmacologic, anesthetic, and neurosurgical approaches. Several pharmacologic controversies, including the choice of drug, route and method of administration, and tolerance development and risk of substance abuse, have emerged with the use of opioids on a chronic basis in the cancer population. The social and moral implications involve the issue of who will pay for high technology pain management approaches for patients either at home or in hospice care and the ethical considerations in managing pain with opioid drugs. Carefully designed studies to assess these factors, coupled with broad educational programs, will improve the care of cancer patients in pain and expand our understanding of these important issues. PMID:2566369

  9. [Pain: an approach to its understanding and management].

    PubMed

    Jacob, Graciela

    2013-01-01

    The article highlights that pain is a human experience that goes beyond the merely physical, and notes the importance of understanding that only the sufferer is able to describe and quantify it. Describe the pain not only as a symptom, more than that is feeling, and emotion and emphasizes the role of the doctor-patient relationship in their approach. It emphasizes the neurobiological, psychosocial and spiritual dimensions of pain and the need for an interdisciplinary approach. Upgrade contributions of neurobiology in brain modulation of pain and the origins of the levels of sensitivity and pain tolerance. Rescue the importance of recognizing the total pain and suffering in the pain therapeutic approach, and highlights the difficulties of the health team. Review various international human rights instruments, to support the argument that the patient should be protected from the inadequate treatment of pain. Lack of education and updating of health professionals is another major problem. Finally emphasizes that pain relief is a human right and the inadequacy of treatment is a serious ethical lapse. PMID:24312922

  10. An equine pain face

    PubMed Central

    Gleerup, Karina B; Forkman, Björn; Lindegaard, Casper; Andersen, Pia H

    2015-01-01

    Objective The objective of this study was to investigate the existence of an equine pain face and to describe this in detail. Study design Semi-randomized, controlled, crossover trial. Animals Six adult horses. Methods Pain was induced with two noxious stimuli, a tourniquet on the antebrachium and topical application of capsaicin. All horses participated in two control trials and received both noxious stimuli twice, once with and once without an observer present. During all sessions their pain state was scored. The horses were filmed and the close-up video recordings of the faces were analysed for alterations in behaviour and facial expressions. Still images from the trials were evaluated for the presence of each of the specific pain face features identified from the video analysis. Results Both noxious challenges were effective in producing a pain response resulting in significantly increased pain scores. Alterations in facial expressions were observed in all horses during all noxious stimulations. The number of pain face features present on the still images from the noxious challenges were significantly higher than for the control trial (p = 0.0001). Facial expressions representative for control and pain trials were condensed into explanatory illustrations. During pain sessions with an observer present, the horses increased their contact-seeking behavior. Conclusions and clinical relevance An equine pain face comprising ‘low’ and/or ‘asymmetrical’ ears, an angled appearance of the eyes, a withdrawn and/or tense stare, mediolaterally dilated nostrils and tension of the lips, chin and certain facial muscles can be recognized in horses during induced acute pain. This description of an equine pain face may be useful for improving tools for pain recognition in horses with mild to moderate pain. PMID:25082060

  11. Effectiveness of tizanidine in neuropathic pain: an open-label study.

    PubMed

    Semenchuk, M R; Sherman, S

    2000-01-01

    The purpose of this research trial is to assess the effectiveness and tolerability of tizanidine in neuropathic pain. In an open-label study, patients with neuropathic pain received 1 to 4 mg of tizanidine once daily for 7 days, followed by weekly dose escalation of 2 to 8 mg to his/her effective or maximum tolerated dose or a maximum of 36 mg over an 8-week period. Treatment effects were assessed, using average weekly pain scores as well as biweekly scores for patient global assessment of pain relief, the neuropathic pain scale, and wisconsin brief pain inventory. Frequency and severity of adverse events were examined also. Twenty-three patients were enrolled. The mean average weekly pain score at baseline was 6.9, which decreased by 1.7 points at the end of week 8 to 5.2 (p < or =.01). A total of 15 patients (68%) reported that their pain relief was improved or much improved with tizanidine therapy, and 2 of these patients became completely pain-free. The following neuropathic pain qualities were significantly lower at week 8 compared with baseline: intense, sharp, hot, dull, cold, sensitive, unpleasant, and deep pain. There was a significant decline in pain quantity and interference of pain on quality of life from baseline to week 8. The mean effective or maximum tolerated dose was 23 mg/day (range 6 to 36 mg/day). Side effects consisted primarily of dizziness/lightheadedness (52%), drowsiness (48%), fatigue/weakness (43%), dry mouth (39%), gastrointestinal upset (30%), and sleep difficulty (22%). One patient developed significant elevation in liver function tests (LFTS) With symptoms at week 4. Tizanidine therapy was discontinued. LFTS returned to normal in 3 weeks. Tizanidine might be an effective treatment for neuropathic pain, offering an alternative for patients poorly responsive to other medications. A larger, randomized placebo-controlled trial is recommended. In addition, comparative studies with alternative agents should be sought. PMID:14622612

  12. A possible neural mechanism for photosensitivity in chronic pain.

    PubMed

    Martenson, Melissa E; Halawa, Omar I; Tonsfeldt, Karen J; Maxwell, Charlene A; Hammack, Nora; Mist, Scott D; Pennesi, Mark E; Bennett, Robert M; Mauer, Kim M; Jones, Kim D; Heinricher, Mary M

    2016-04-01

    Patients with functional pain disorders often complain of generalized sensory hypersensitivity, finding sounds, smells, or even everyday light aversive. The neural basis for this aversion is unknown, but it cannot be attributed to a general increase in cortical sensory processing. Here, we quantified the threshold for aversion to light in patients with fibromyalgia, a pain disorder thought to reflect dysregulation of pain-modulating systems in the brain. These individuals expressed discomfort at light levels substantially lower than that of healthy control subjects. Complementary studies in lightly anesthetized rat demonstrated that a subset of identified pain-modulating neurons in the rostral ventromedial medulla unexpectedly responds to light. Approximately half of the pain-facilitating "ON-cells" and pain-inhibiting "OFF-cells" sampled exhibited a change in firing with light exposure, shifting the system to a pronociceptive state with the activation of ON-cells and suppression of OFF-cell firing. The change in neuronal firing did not require a trigeminal or posterior thalamic relay, but it was blocked by the inactivation of the olivary pretectal nucleus. Light exposure also resulted in a measurable but modest decrease in the threshold for heat-evoked paw withdrawal, as would be expected with engagement of this pain-modulating circuitry. These data demonstrate integration of information about light intensity with somatic input at the level of single pain-modulating neurons in the brain stem of the rat under basal conditions. Taken together, our findings in rodents and humans provide a novel mechanism for abnormal photosensitivity and suggest that light has the potential to engage pain-modulating systems such that normally innocuous inputs are perceived as aversive or even painful. PMID:26785323

  13. Mechanisms of immunological tolerance.

    PubMed

    Waldmann, Herman

    2016-03-01

    There is increasing interest in establishing diagnostic markers of immunological tolerance applicable to efforts to minimize drug immunosuppression in transplantation and chronic immunological diseases. It is hoped that an understanding of the diverse mechanisms that can contribute to tolerance will guide efforts to establish diagnostic tolerance biomarkers. Not only would these be valuable for management of autoimmune diseases, transplants and allergies, but they might also guide efforts to override tolerance processes in cancer and vaccine development. Where tolerance is generated by deletion or inactivation of antigen reactive lymphocytes, it is unlikely that any long-term-valid blood biomarkers might be found. Where tolerance is mediated by active regulatory mechanisms, indicators that can be usefully measured may emerge, but these would likely show significant heterogeneity reflecting the diversity of active tolerance processes operating in different individuals. Given this, the most useful "kits" might be those "smart" enough to detect this diversity of tolerance players. PMID:26036868

  14. Lactose tolerance tests

    MedlinePlus

    Hydrogen breath test for lactose tolerance ... Two common methods include: Lactose tolerance blood test Hydrogen breath test The hydrogen breath test is the preferred method. It measures the amount of hydrogen in the air you breathe out. ...

  15. Sweet Taste and Menthol Increase Cough Reflex Thresholds

    PubMed Central

    Wise, Paul M.; Breslin, Paul A.S.; Dalton, Pamela

    2015-01-01

    Cough is a vital protective reflex that is triggered by both mechanical and chemical stimuli. The current experiments explored how chemosensory stimuli modulate this important reflex. Cough thresholds were measured using a single-inhalation capsaicin challenge. Experiment 1 examined the impact of sweet taste: Cough thresholds were measured after rinsing the mouth with a sucrose solution (sweet) or with water (control). Experiment 2 examined the impact of menthol: Cough thresholds were measured after inhaling headspace above a menthol solution (menthol vapor) or headspace above the mineral oil solvent (control). Experiment 3 examined the impact of rinsing the mouth with a (bitter) sucrose octaacetate solution. Rinsing with sucrose and inhaling menthol vapor significantly increased measured cough thresholds. Rinsing with sucrose octaacete caused a non-significant decrease in cough thresholds, an important demonstration of specificity. Decreases in cough reflex sensitivity from sucrose or menthol could help explain why cough syrups without pharmacologically active ingredients are often almost as effective as formulations with an added drug. Further, the results support the idea that adding menthol to cigarettes might make tobacco smoke more tolerable for beginning smokers, at least in part, by reducing the sensitivity of an important airway defense mechanism. PMID:22465565

  16. Relation of the factor to menstrual pain and musculoskeletal pain

    PubMed Central

    Lee, Jang-Won; Park, Hye-Sang

    2015-01-01

    The purpose of the present study is to investigate the relationship between the regions of menstrual pain and of myofascial pain syndrome, which is the main cause of musculoskeletal pain, as well as to examine the changes and relationships among the menstrual pain-related factors, which are pain level, pain area, activity, appetite, mood, and sleeping pattern. The subjects were 13 sufferers of musculoskeletal pain and 17 non-sufferers. Pain diary and pain chart systems were used for the measurement of menstrual pain-related factors and musculoskeletal pain. Data were analyzed using repeated ANOVA. The results show that there are significant differences between the two groups in pain level, activity, and mood during menstruation periods (P< 0.05). The area of musculoskeletal pain and menstrual pain were found to be the same. PMID:25960984

  17. Spatial Variable Thresholding for SCALES

    NASA Astrophysics Data System (ADS)

    Nejadmalayeri, Alireza; Vasilyev, Oleg V.; Vezolainen, Alexei; de Stefano, Giuliano

    2009-11-01

    The Stochastic Coherent Adaptive Large Eddy Simulation (SCALES) is a novel wavelet-based approach that resolves energy containing turbulent motions using wavelet multiresolution decomposition and self-adaptivity. The extraction of the most energetic structures is achieved using wavelet thresholding filter with a priori prescribed threshold level. This strategy, although successful, has a major drawback: the thresholding criterion is global and does not fully utilize the spatial/temporal intermittency of the turbulent flow. In the current numerical effort, for the first time (to the best of our knowledge), the concept of physics-based spatially variable thresholding in the context of wavelet-based numerical techniques for solving PDEs is introduced. The procedure consists of tracking the wavelet thresholding-factor within a Lagrangian frame by exploiting a Lagrangian Path-Line Diffusive Averaging approach that uses linear averaging along characteristics. The results for incompressible flow around NACA 0015 airfoil show a very robust and fast methodology for adjusting the thresholding-factor based on dynamically important flow characteristics, for instance, the magnitude of vorticity or strain rate.

  18. Threshold models in radiation carcinogenesis

    SciTech Connect

    Hoel, D.G.; Li, P.

    1998-09-01

    Cancer incidence and mortality data from the atomic bomb survivors cohort has been analyzed to allow for the possibility of a threshold dose response. The same dose-response models as used in the original papers were fit to the data. The estimated cancer incidence from the fitted models over-predicted the observed cancer incidence in the lowest exposure group. This is consistent with a threshold or nonlinear dose-response at low-doses. Thresholds were added to the dose-response models and the range of possible thresholds is shown for both solid tumor cancers as well as the different leukemia types. This analysis suggests that the A-bomb cancer incidence data agree more with a threshold or nonlinear dose-response model than a purely linear model although the linear model is statistically equivalent. This observation is not found with the mortality data. For both the incidence data and the mortality data the addition of a threshold term significantly improves the fit to the linear or linear-quadratic dose response for both total leukemias and also for the leukemia subtypes of ALL, AML, and CML.

  19. Thresholds for Correcting Errors, Erasures, and Faulty Syndrome Measurements in Degenerate Quantum Codes

    NASA Astrophysics Data System (ADS)

    Dumer, Ilya; Kovalev, Alexey A.; Pryadko, Leonid P.

    2015-07-01

    We suggest a technique for constructing lower (existence) bounds for the fault-tolerant threshold to scalable quantum computation applicable to degenerate quantum codes with sublinear distance scaling. We give explicit analytic expressions combining probabilities of erasures, depolarizing errors, and phenomenological syndrome measurement errors for quantum low-density parity-check codes with logarithmic or larger distances. These threshold estimates are parametrically better than the existing analytical bound based on percolation.

  20. Thresholds for Correcting Errors, Erasures, and Faulty Syndrome Measurements in Degenerate Quantum Codes.

    PubMed

    Dumer, Ilya; Kovalev, Alexey A; Pryadko, Leonid P

    2015-07-31

    We suggest a technique for constructing lower (existence) bounds for the fault-tolerant threshold to scalable quantum computation applicable to degenerate quantum codes with sublinear distance scaling. We give explicit analytic expressions combining probabilities of erasures, depolarizing errors, and phenomenological syndrome measurement errors for quantum low-density parity-check codes with logarithmic or larger distances. These threshold estimates are parametrically better than the existing analytical bound based on percolation. PMID:26274403

  1. Hypersensitivity Due to Stress

    PubMed Central

    Hampf, Göran

    1989-01-01

    Basal, preoperative and postoperative perception thresholds and pain tolerance thresholds were studied in 32 patients undergoing minor oral surgery using monopolar stimulation of a vital anterior tooth. Significant differences were found between the perception and pain tolerance thresholds, the basal and preoperative perception and pain tolerance thresholds being higher than the postoperative thresholds. Decreased postoperative pain tolerance thresholds were found in patients with increased anxiety. The effect of premedication on the thresholds was also studied. Premedication with diazepam and pethidine caused an increase in the preoperative perception and pain tolerance thresholds but did not prevent a decrease in the postoperative perception and pain tolerance thresholds. The increase in the preoperative perception and pain tolerance thresholds caused by the premedication was equal in magnitude to the decrease in the thresholds measured immediately after surgery. PMID:2490058

  2. [Analgesic management of acute pain in patients receiving methadone or buprenorphine].

    PubMed

    Zinck, Louise; Sonne, Nan M; Madsen, Sidsel Lgdsgaard; Nikolajsen, Lone

    2015-03-01

    In Denmark, approximately 7,600 patients receive maintenance therapy with methadone or buprenorphine because of opioid addiction. These patients have an increased risk of inadequate pain treatment during hospitalization, among others because of tolerance to opioids and poor communication with the staff. The present article describes four common misconceptions among health-care providers that underlie inadequate pain treatment and provides practical recommendations for the analgesic management of acute pain in patients receiving methadone or buprenorphine. PMID:25749118

  3. The genetics of pain and pain inhibition.

    PubMed Central

    Mogil, J S; Sternberg, W F; Marek, P; Sadowski, B; Belknap, J K; Liebeskind, J C

    1996-01-01

    The present review summarizes the current state of knowledge about the genetics of pain-related phenomena and illustrates the scope and power of genetic approaches to the study of pain. We focus on work performed in our laboratories in Jastrzebiec, Poland; Portland, OR; and Los Angeles, which we feel demonstrates the continuing usefulness of classical genetic approaches, especially when used in combination with newly available molecular genetic techniques. PMID:8610166

  4. Peripartum pain management in opioid dependent women

    PubMed Central

    Höflich, Anna S.; Langer, Martin; Jagsch, Reinhold; Bäwert, Andjela; Winklbaur, Bernadette; Fischer, Gabriele; Unger, Annemarie

    2011-01-01

    Increased pain sensitivity and the development of opioid tolerance complicate the treatment of pain experienced by opioid maintained pregnant women during delivery and the perinatal period. The aim of the present study was to investigate differences in pain management of opioid maintained compared to non-dependent pregnant women during delivery and the postpartum period. 40 deliveries of 37 opioid dependent women enrolled in a double-blind, double-dummy randomized controlled trial (RCT) examining the safety and efficacy of methadone (mean dose at the time of delivery = 63.89 mg) and buprenorphine (mean dose at the time of delivery = 14.05 mg) during pregnancy were analyzed and participants were matched to a non-dependent comparison group of 80 pregnant women. Differences in pain management (opioid and non-opioid analgesic medication) during delivery and perinatal period were analyzed. Following cesarean delivery opioid maintained women received significantly less opioid analgesics (day of delivery p = 0.038; day 1: p = 0.02), NSAIDs were administered more frequently to opioid dependent patients than to the comparison group during cesarean section and on the third day postpartum. Significantly higher nicotine consumption in the group of opioid dependent women had a strong influence on the retrieved results, and might be considered as an independent factor of altered pain experience. Differences in pain treatment became evident when comparing opioid maintained women to healthy controls. These differences might be based on psychosocial consequences of opioid addiction along with the lack of an interdisciplinary consensus on pain treatment protocols for opioid dependent patients. PMID:22396085

  5. Decoding the perception of pain from fMRI using multivariate pattern analysis

    PubMed Central

    Brodersen, Kay H.; Wiech, Katja; Lomakina, Ekaterina I.; Lin, Chia-shu; Buhmann, Joachim M.; Bingel, Ulrike; Ploner, Markus; Stephan, Klaas Enno; Tracey, Irene

    2012-01-01

    Pain is known to comprise sensory, cognitive, and affective aspects. Despite numerous previous fMRI studies, however, it remains open which spatial distribution of activity is sufficient to encode whether a stimulus is perceived as painful or not. In this study, we analyzed fMRI data from a perceptual decision-making task in which participants were exposed to near-threshold laser pulses. Using multivariate analyses on different spatial scales, we investigated the predictive capacity of fMRI data for decoding whether a stimulus had been perceived as painful. Our analysis yielded a rank order of brain regions: during pain anticipation, activity in the periaqueductal gray (PAG) and orbitofrontal cortex (OFC) afforded the most accurate trial-by-trial discrimination between painful and non-painful experiences; whereas during the actual stimulation, primary and secondary somatosensory cortex, anterior insula, dorsolateral and ventrolateral prefrontal cortex, and OFC were most discriminative. The most accurate prediction of pain perception from the stimulation period, however, was enabled by the combined activity in pain regions commonly referred to as the ‘pain matrix’. Our results demonstrate that the neural representation of (near-threshold) pain is spatially distributed and can be best described at an intermediate spatial scale. In addition to its utility in establishing structure-function mappings, our approach affords trial-by-trial predictions and thus represents a step towards the goal of establishing an objective neuronal marker of pain perception. PMID:22922369

  6. Decoding the perception of pain from fMRI using multivariate pattern analysis.

    PubMed

    Brodersen, Kay H; Wiech, Katja; Lomakina, Ekaterina I; Lin, Chia-Shu; Buhmann, Joachim M; Bingel, Ulrike; Ploner, Markus; Stephan, Klaas Enno; Tracey, Irene

    2012-11-15

    Pain is known to comprise sensory, cognitive, and affective aspects. Despite numerous previous fMRI studies, however, it remains open which spatial distribution of activity is sufficient to encode whether a stimulus is perceived as painful or not. In this study, we analyzed fMRI data from a perceptual decision-making task in which participants were exposed to near-threshold laser pulses. Using multivariate analyses on different spatial scales, we investigated the predictive capacity of fMRI data for decoding whether a stimulus had been perceived as painful. Our analysis yielded a rank order of brain regions: during pain anticipation, activity in the periaqueductal gray (PAG) and orbitofrontal cortex (OFC) afforded the most accurate trial-by-trial discrimination between painful and non-painful experiences; whereas during the actual stimulation, primary and secondary somatosensory cortex, anterior insula, dorsolateral and ventrolateral prefrontal cortex, and OFC were most discriminative. The most accurate prediction of pain perception from the stimulation period, however, was enabled by the combined activity in pain regions commonly referred to as the 'pain matrix'. Our results demonstrate that the neural representation of (near-threshold) pain is spatially distributed and can be best described at an intermediate spatial scale. In addition to its utility in establishing structure-function mappings, our approach affords trial-by-trial predictions and thus represents a step towards the goal of establishing an objective neuronal marker of pain perception. PMID:22922369

  7. Mechanisms of cardiac pain.

    PubMed

    Foreman, Robert D; Garrett, Kennon M; Blair, Robert W

    2015-04-01

    Angina pectoris is cardiac pain that typically is manifested as referred pain to the chest and upper left arm. Atypical pain to describe localization of the perception, generally experienced more by women, is referred to the back, neck, and/or jaw. This article summarizes the neurophysiological and pharmacological mechanisms for referred cardiac pain. Spinal cardiac afferent fibers mediate typical anginal pain via pathways from the spinal cord to the thalamus and ultimately cerebral cortex. Spinal neurotransmission involves substance P, glutamate, and transient receptor potential vanilloid-1 (TRPV1) receptors; release of neurokinins such as nuclear factor kappa b (NF-kb) in the spinal cord can modulate neurotransmission. Vagal cardiac afferent fibers likely mediate atypical anginal pain and contribute to cardiac ischemia without accompanying pain via relays through the nucleus of the solitary tract and the C1-C2 spinal segments. The psychological state of an individual can modulate cardiac nociception via pathways involving the amygdala. Descending pathways originating from nucleus raphe magnus and the pons also can modulate cardiac nociception. Sensory input from other visceral organs can mimic cardiac pain due to convergence of this input with cardiac input onto spinothalamic tract neurons. Reduction of converging nociceptive input from the gallbladder and gastrointestinal tract can diminish cardiac pain. Much work remains to be performed to discern the interactions among complex neural pathways that ultimately produce or do not produce the sensations associated with cardiac pain. PMID:25880519

  8. 21. Phantom pain.

    PubMed

    Wolff, Andre; Vanduynhoven, Eric; van Kleef, Maarten; Huygen, Frank; Pope, Jason E; Mekhail, Nagy

    2011-01-01

    Phantom pain is pain caused by elimination or interruption of sensory nerve impulses by destroying or injuring the sensory nerve fibers after amputation or deafferentation. The reported incidence of phantom limb pain after trauma, injury or peripheral vascular diseases is 60% to 80%. Over half the patients with phantom pain have stump pain as well. Phantom pain can also occur in other parts of the body; it has been described after mastectomies and enucleation of the eye. Most patients with phantom pain have intermittent pain, with intervals that range from 1 day to several weeks. Even intervals of over a year have been reported. The pain often presents itself in the form of attacks that vary in duration from a few seconds to minutes or hours. In most cases, the pain is experienced distally in the missing limb, in places with the most extensive innervation density and cortical representation. Although there are still many questions as to the underlying mechanisms, peripheral as well as central neuronal mechanisms seem to be involved. Conservative therapy consists of drug treatment with amitriptyline, tramadol, carbamazepine, ketamine, or morphine. Based on the available evidence some effect may be expected from drug treatment. When conservative treatment fails, pulsed radiofrequency treatment of the stump neuroma or of the spinal ganglion (DRG) or spinal cord stimulation could be considered (evidence score 0). These treatments should only be applied in a study design. PMID:21447079

  9. Pain Management in Newborns

    PubMed Central

    Hall, Richard W.; Anand, Kanwaljeet J. S.

    2014-01-01

    Effective pain management is a desirable standard of care for preterm and term newborns and may potentially improve their clinical and neurodevelopmental outcomes. Neonatal pain should be assessed routinely using context-specific, validated and objective pain methods, despite the limitations of currently available tools. Reducing invasive procedures, and using pharmacological, behavioral or environmental measures can be used to manage neonatal pain. Non-pharmacologic approaches include kangaroo care, facilitated tucking, non-nutritive sucking, sucrose and other sweeteners, massage and acupuncture therapy. They are used for procedures causing acute, transient, or mild pain, or as adjunctive therapy for moderate or severe pain. Local and topical anesthetics can reduce the acute pain caused by skin-breaking or mucosa-injuring procedures. Opioids form the mainstay for treatment of severe pain; morphine and fentanyl are the most commonly used drugs, although other opioids are also available. Non-opioid drugs include various sedatives and anesthetic agents, mostly used as adjunctive therapy in ventilated neonates. Acetaminophen, ibuprofen and other drugs are used for neonates, although their efficacy and safety remains unproven. Approaches for implementing an effective pain management program in the Neonatal ICU are summarized, together with practical protocols for procedural, postoperative, and mechanical ventilation-associated neonatal pain and stress. PMID:25459780

  10. Pain in Parkinson's disease.

    PubMed

    Ha, Ainhi D; Jankovic, Joseph

    2012-04-01

    Pain and other nonmotor symptoms in PD are increasingly recognized as a major cause of reduced health-related quality of life. Pain in PD may be categorized into a number of different subtypes, including musculoskeletal, dystonic, radicular neuropathic, and central pain. The onset of pain can vary in relation to motor symptoms, and may precede the appearance of motor symptoms by several years, or occur after the diagnosis of PD has been made. Pain in PD is frequently under-recognized and is often inadequately treated. Levodopa-related dystonia may respond to manipulation of dopaminergic medication. Dopaminergic therapy may also improve musculoskeletal pain related to rigidity and akinesia, as well as akathisia in PD. Botulinum toxin injections can be effective for treatment of painful focal dystonia. Pain and dysesthesia have been reported to improve with DBS, in some cases. Increased understanding of basal ganglia pathways has provided further insights into the pathogenesis of pain in PD, but the exact mechanism of pain processing and modulation remains unclear. PMID:21953990

  11. Hypothesizing that brain reward circuitry genes are genetic antecedents of pain sensitivity and critical diagnostic and pharmacogenomic treatment targets for chronic pain conditions

    PubMed Central

    Chen, Amanda L.-C.; Chen, Thomas J.H.; Waite, Roger L.; Reinking, Jeffrey; Tung, Howard L.; Rhoades, Patrick; Downs, B. William; Braverman, Eric; Braverman, Dasha; Kerner, Mallory; Blum, Seth H.; DiNubile, Nicholas; Smith, David; Oscar-Berman, Marlene; Prihoda, Thomas J.; Floyd, John B.; O’Brien, David; Liu, H.H.; Blum, Kenneth

    2014-01-01

    SUMMARY While it is well established that the principal ascending pathways for pain originate in the dorsal horn of the spinal cord and in the medulla, the control and sensitivity to pain may reside in additional neurological loci, especially in the mesolimbic system of the brain (i.e., a reward center), and a number of genes and associated polymorphisms may indeed impact pain tolerance and or sensitivity. It is hypothesized that these polymorphisms associate with a predisposition to intolerance or tolerance to pain. It is further hypothesized that identification of certain gene polymorphisms provides a unique therapeutic target to assist in the treatment of pain. It is hereby proposed that pharmacogenetic testing of certain candidate genes (i.e., mu receptors, PENK etc.) will result in pharmacogenomic solutions personalized to the individual patient, with potential improvement in clinical outcomes. PMID:18951726

  12. Pain in cancer survivors.

    PubMed

    Glare, Paul A; Davies, Pamela S; Finlay, Esmé; Gulati, Amitabh; Lemanne, Dawn; Moryl, Natalie; Oeffinger, Kevin C; Paice, Judith A; Stubblefield, Michael D; Syrjala, Karen L

    2014-06-01

    Pain is a common problem in cancer survivors, especially in the first few years after treatment. In the longer term, approximately 5% to 10% of survivors have chronic severe pain that interferes with functioning. The prevalence is much higher in certain subpopulations, such as breast cancer survivors. All cancer treatment modalities have the potential to cause pain. Currently, the approach to managing pain in cancer survivors is similar to that for chronic cancer-related pain, pharmacotherapy being the principal treatment modality. Although it may be appropriate to continue strong opioids in survivors with moderate to severe pain, most pain problems in cancer survivors will not require them. Moreover, because more than 40% of cancer survivors now live longer than 10 years, there is growing concern about the long-term adverse effects of opioids and the risks of misuse, abuse, and overdose in the nonpatient population. As with chronic nonmalignant pain, multimodal interventions that incorporate nonpharmacologic therapies should be part of the treatment strategy for pain in cancer survivors, prescribed with the aim of restoring functionality, not just providing comfort. For patients with complex pain issues, multidisciplinary programs should be used, if available. New or worsening pain in a cancer survivor must be evaluated to determine whether the cause is recurrent disease or a second malignancy. This article focuses on patients with a history of cancer who are beyond the acute diagnosis and treatment phase and on common treatment-related pain etiologies. The benefits and harms of the various pharmacologic and nonpharmacologic options for pain management in this setting are reviewed. PMID:24799477

  13. Pain in Cancer Survivors

    PubMed Central

    Glare, Paul A.; Davies, Pamela S.; Finlay, Esmé; Gulati, Amitabh; Lemanne, Dawn; Moryl, Natalie; Oeffinger, Kevin C.; Paice, Judith A.; Stubblefield, Michael D.; Syrjala, Karen L.

    2014-01-01

    Pain is a common problem in cancer survivors, especially in the first few years after treatment. In the longer term, approximately 5% to 10% of survivors have chronic severe pain that interferes with functioning. The prevalence is much higher in certain subpopulations, such as breast cancer survivors. All cancer treatment modalities have the potential to cause pain. Currently, the approach to managing pain in cancer survivors is similar to that for chronic cancer-related pain, pharmacotherapy being the principal treatment modality. Although it may be appropriate to continue strong opioids in survivors with moderate to severe pain, most pain problems in cancer survivors will not require them. Moreover, because more than 40% of cancer survivors now live longer than 10 years, there is growing concern about the long-term adverse effects of opioids and the risks of misuse, abuse, and overdose in the nonpatient population. As with chronic nonmalignant pain, multimodal interventions that incorporate nonpharmacologic therapies should be part of the treatment strategy for pain in cancer survivors, prescribed with the aim of restoring functionality, not just providing comfort. For patients with complex pain issues, multidisciplinary programs should be used, if available. New or worsening pain in a cancer survivor must be evaluated to determine whether the cause is recurrent disease or a second malignancy. This article focuses on patients with a history of cancer who are beyond the acute diagnosis and treatment phase and on common treatment-related pain etiologies. The benefits and harms of the various pharmacologic and nonpharmacologic options for pain management in this setting are reviewed. PMID:24799477

  14. Neurological diseases and pain

    PubMed Central

    2012-01-01

    Chronic pain is a frequent component of many neurological disorders, affecting 20–40% of patients for many primary neurological diseases. These diseases result from a wide range of pathophysiologies including traumatic injury to the central nervous system, neurodegeneration and neuroinflammation, and exploring the aetiology of pain in these disorders is an opportunity to achieve new insight into pain processing. Whether pain originates in the central or peripheral nervous system, it frequently becomes centralized through maladaptive responses within the central nervous system that can profoundly alter brain systems and thereby behaviour (e.g. depression). Chronic pain should thus be considered a brain disease in which alterations in neural networks affect multiple aspects of brain function, structure and chemistry. The study and treatment of this disease is greatly complicated by the lack of objective measures for either the symptoms or the underlying mechanisms of chronic pain. In pain associated with neurological disease, it is sometimes difficult to obtain even a subjective evaluation of pain, as is the case for patients in a vegetative state or end-stage Alzheimer's disease. It is critical that neurologists become more involved in chronic pain treatment and research (already significant in the fields of migraine and peripheral neuropathies). To achieve this goal, greater efforts are needed to enhance training for neurologists in pain treatment and promote greater interest in the field. This review describes examples of pain in different neurological diseases including primary neurological pain conditions, discusses the therapeutic potential of brain-targeted therapies and highlights the need for objective measures of pain. PMID:22067541

  15. Fixed orthodontic appliances cause pain and disturbance in somatosensory function.

    PubMed

    Shen, Huijie; Shao, Sheng; Zhang, Jinglu; Wang, Zhendong; Lv, Dong; Chen, Wenjing; Svensson, Peter; Wang, Kelun

    2016-02-01

    This study aimed to assess the short-term effects of orthodontic pain on quantitative sensory testing (QST) in subjects receiving fixed orthodontic treatment. Twenty patients and 12 healthy volunteers (as controls) participated. All 20 patients had bonded AO self-ligating brackets, with a 0.014 super elastic nickel-titanium arch wire placed in the brackets. Pain [self-reported on a visual analog scale (VAS)], and thermal and mechanical thresholds, were tested at six time points--before (baseline), and 2 h, 24 h, 7 d, 14 d, and 30 d after, force application--in the treatment group. The attached gingiva adjacent to the left upper central incisor (21 gingiva) was hypersensitive to cold stimuli (i.e. increased cold detection thresholds were detected) in the treatment group. The pressure pain thresholds of the left upper central incisor (21) and 21 gingiva were significantly reduced. Our results suggest clear signs of sensitization of the trigeminal nociceptive system up to 1 month after force application and orthodontic pain. Quantitative assessment of somatosensory function may help to provide a better understanding and profiling of the underlying neurobiological mechanisms related to orthodontic pain. PMID:26715259

  16. Deficits in pain perception in borderline personality disorder: results from the thermal grill illusion.

    PubMed

    Bekrater-Bodmann, Robin; Chung, Boo Young; Richter, Ingmarie; Wicking, Manon; Foell, Jens; Mancke, Falk; Schmahl, Christian; Flor, Herta

    2015-10-01

    It is well documented that borderline personality disorder (BPD) is characterized by reduced pain sensitivity, which might be related to nonsuicidal self-injury and dissociative experiences in patients with BPD. However, it remains an open question whether this insensitivity relies at least partly on altered sensory integration or on an altered evaluation of pain or a combination of both. In this study, we used the thermal grill illusion (TGI), describing a painful sensation induced by the application of alternating cold and warm nonnoxious stimuli, in patients with either current or remitted BPD as well as matched healthy controls. Two additional conditions, applying warm or cold temperatures only, served as control. We further assessed thermal perception, discrimination, and pain thresholds. We found significantly reduced heat and cold pain thresholds for the current BPD group, as well as reduced cold pain thresholds for the remitted BPD group, as compared with the HC group. Current BPD patients perceived a less-intense TGI in terms of induced pain and unpleasantness, while their general ability to perceive this kind of illusion seemed to be unaffected. Thermal grill illusion magnitude was negatively correlated with dissociation and traumatization only in the current BPD patients. These results indicate that higher-order pain perception is altered in current BPD, which seems to normalize after remission. We discuss these findings against the background of neurophysiological evidence for the TGI in general and reduced pain sensitivity in BPD and suggest a relationship to alterations in N-methyl-D-aspartate neurotransmission. PMID:26098439

  17. Pain catastrophizing and cortical responses in amputees with varying levels of phantom limb pain: a high-density EEG brain-mapping study.

    PubMed

    Vase, Lene; Egsgaard, Line Lindhardt; Nikolajsen, Lone; Svensson, Peter; Jensen, Troels Staehelin; Arendt-Nielsen, Lars

    2012-05-01

    Pain catastrophizing has been associated with phantom limb pain, but so far the cortical processes and the brain regions involved in this relationship have not been investigated. It was therefore tested whether catastrophizing was related to (1) spontaneous pain, (2) somatosensory activity and (3) cortical responses in phantom limb pain patients. The cortical responses were investigated via electroencephalography (EEG) as it has a high temporal resolution which may be ideal for investigating especially the attentional and hypervigilance aspect of catastrophizing to standardized acute stimuli. Eighteen upper limb amputees completed the pain catastrophizing scale. Patients' spontaneous pain levels (worst and average pain, numerical rating scales) and thresholds to electrical stimulation (sensory detection and VRS2: intense but not painful) were determined. Non-painful electrical stimuli were applied to both the affected and non-affected arm, while high-resolution (128 channels) EEG signals were recorded. Catastrophizing accounted for significant amounts of the variance in relation to spontaneous pain, especially worst pain (64.1%), and it was significantly associated with thresholds. At the affected side, catastrophizing was significantly related to the power RMS of the N/P135 dipole located in the area around the secondary somatosensory cortex which has been shown to be associated with arousal and expectations. These findings corroborate the attentional model of pain catastrophizing by indicating that even non-painful stimuli are related to enhanced attention to and negative expectations of stimuli, and they suggest that memory processes may be central to understanding the link between catastrophizing and pain. PMID:22349560

  18. Experimental Sleep Restriction Facilitates Pain and Electrically Induced Cortical Responses

    PubMed Central

    Matre, Dagfinn; Hu, Li; Viken, Leif A.; Hjelle, Ingri B.; Wigemyr, Monica; Knardahl, Stein; Sand, Trond; Nilsen, Kristian Bernhard

    2015-01-01

    Study Objectives: Sleep restriction (SR) has been hypothesized to sensitize the pain system. The current study determined whether experimental sleep restriction had an effect on experimentally induced pain and pain-elicited electroencephalographic (EEG) responses. Design: A paired crossover study. Intervention: Pain testing was performed after 2 nights of 50% SR and after 2 nights with habitual sleep (HS). Setting: Laboratory experiment at research center. Participants: Self-reported healthy volunteers (n = 21, age range: 18–31 y). Measurements and Results: Brief high-density electrical stimuli to the forearm skin produced pinprick-like pain. Subjective pain ratings increased after SR, but only in response to the highest stimulus intensity (P = 0.018). SR increased the magnitude of the pain-elicited EEG response analyzed in the time-frequency domain (P = 0.021). Habituation across blocks did not differ between HS and SR. Event-related desynchronization (ERD) was reduced after SR (P = 0.039). Pressure pain threshold of the trapezius muscle region also decreased after SR (P = 0.017). Conclusion: Sleep restriction (SR) increased the sensitivity to pressure pain and to electrically induced pain of moderate, but not low, intensity. The increased electrical pain could not be explained by a difference in habituation. Increased response magnitude is possibly related to reduced processing within the somatosensory cortex after partial SR. Citation: Matre D, Hu L, Viken LA, Hjelle IB, Wigemyr M, Knardahl S, Sand T, Nilsen KB. Experimental sleep restriction facilitates pain and electrically induced cortical responses. SLEEP 2015;38(10):1607–1617. PMID:26194577

  19. Thalamic pain: anatomical and physiological indices of prediction.

    PubMed

    Vartiainen, Nuutti; Perchet, Caroline; Magnin, Michel; Creac'h, Christelle; Convers, Philippe; Nighoghossian, Norbert; Mauguière, François; Peyron, Roland; Garcia-Larrea, Luis

    2016-03-01

    Thalamic pain is a severe and treatment-resistant type of central pain that may develop after thalamic stroke. Lesions within the ventrocaudal regions of the thalamus carry the highest risk to develop pain, but its emergence in individual patients remains impossible to predict. Because damage to the spino-thalamo-cortical system is a crucial factor in the development of central pain, in this study we combined detailed anatomical atlas-based mapping of thalamic lesions and assessment of spinothalamic integrity using quantitative sensory analysis and laser-evoked potentials in 42 thalamic stroke patients, of whom 31 had developed thalamic pain. More than 97% of lesions involved an area between 2 and 7 mm above the anterior-posterior commissural plane. Although most thalamic lesions affected several nuclei, patients with central pain showed maximal lesion convergence on the anterior pulvinar nucleus (a major spinothalamic target) while the convergence area lay within the ventral posterior lateral nucleus in pain-free patients. Both involvement of the anterior pulvinar nucleus and spinothalamic dysfunction (nociceptive thresholds, laser-evoked potentials) were significantly associated with the development of thalamic pain, whereas involvement of ventral posterior lateral nucleus and lemniscal dysfunction (position sense, graphaesthesia, pallaesthesia, stereognosis, standard somatosensory potentials) were similarly distributed in patients with or without pain. A logistic regression model combining spinothalamic dysfunction and anterior pulvinar nucleus involvement as regressors had 93% sensitivity and 87% positive predictive value for thalamic pain. Lesion of spinothalamic afferents to the posterior thalamus appears therefore determinant to the development of central pain after thalamic stroke. Sorting out of patients at different risks of developing thalamic pain may be achievable at the individual level by combining lesion localization and functional investigation of the spinothalamic system. As the methods proposed here do not need complex manipulations, they can be added to routine patients' work up, and the results replicated by other investigators in the field. PMID:26912644

  20. [Botulinum toxin and painful peripheral neuropathies: what should be expected?].

    PubMed

    Ranoux, D

    2011-01-01

    Botulinum toxin type A (BTX-A) is a potent neurotoxin that blocks acetylcholine release from presynaptic nerve terminals by cleaving the SNARE complex. BTX-A has been reported to have analgesic effects independent of its action on muscle tone. The most robust results have been observed in patients with neuropathic pain. Neuropathic pain due to peripheral lesions has been the most widely studied. BTX-A has shown its efficacy on pain and allodynia in various animal models of inflammatory neuropathic pain. The only randomized, double-blind, placebo-controlled trial in patients with focal painful neuropathies due to nerve trauma or postherpetic neuralgia demonstrated significant effects on average pain intensity from 2 weeks after the injections to 14 weeks. Most patients reported pain during the injections, but there were no further local or systemic side effects. The efficacy of BTX-A in painful peripheral neuropathies has been more recently studied. Results were positive in the only study in an animal model of peripheral neuropathy. One study in patients with diabetic painful peripheral neuropathy demonstrated a significant decrease in Visual Analog Scale. In conclusion, one session of multiple intradermal injection of BTX-A produces long-lasting analgesic effects in patients with focal painful neuropathies and diabetic neuropathic pain, and is particularly well tolerated. The findings are consistent with a reduction of peripheral sensitisation, the place of a possible central effect remaining to define. Further studies are needed to assess some important issues, i.e. BTX-A efficacy in patients with small fiber neuropathies and the relevance of early and repeated injections. Future studies could also provide valuable insights into pathophysiology of neuropathic pain. PMID:21194720

  1. Pain and Psychological Outcomes After Rehabilitative Treatment for a Woman With Chronic Pelvic Pain With Stage III Cervical Cancer: A Case Report

    PubMed Central

    Alappattu, Meryl J.

    2016-01-01

    Background Chronic pelvic pain and sexual dysfunction are adverse effects of treatment of cervical cancer. Surgery and radiation therapies may result in soft tissue pain and dysfunction, including spasms and trigger points of the pelvic floor muscles that result in pain. In addition to physical restrictions, negative mood associated with pain is believed to intensify and prolong the pain experience. Study Design The purpose of this case report was to describe outcomes of pelvic physical therapy in a 58-year-old woman with chronic pelvic pain after medical treatments for cervical cancer. Case Description The patient reported dyspareunia, hip pain, and lower abdominal, pelvic pain, and fatigue with activities lasting greater than 30 minutes. Interventions included pelvic floor massage, dilator use, and patient education. Symptoms were assessed at baseline and completion of physical therapy, using the Female Sexual Function Index, Fear of Pain Questionnaire–III, Pain Catastrophizing Scale, and Numerical Pain Rating Scale. Outcomes The Female Sexual Function Index score decreased from 7.8 to 2.8, the Fear of Pain Questionnaire– III score decreased from 85 to 73, the Pain Catastrophizing Scale score decreased from 18 to 8, and lower abdominal and pelvic pain decreased from 4 of 10 to 0 of 10, while bilateral hip pain remained at 4 of 10. In addition, she exhibited increased tolerance to mechanical pressure, evidenced by progression in size of a vaginal dilator. Discussion These results suggest that pelvic physical therapy may be useful in treating chronic pelvic pain after cervical cancer treatments and may also help decrease the magnitude of negative mood aspects such as pain-related fear and catastrophizing. PMID:27134605

  2. Clinical relevance of cannabis tolerance and dependence.

    PubMed

    Jones, R T; Benowitz, N L; Herning, R I

    1981-01-01

    Psychoactive drugs are often widely used before tolerance and dependence is fully appreciated. Tolerance to cannabis-induced cardiovascular and autonomic changes, decreased intraocular pressure, sleep and sleep EEG, mood and behavioral changes is acquired and, to a great degree, lost rapidly with optimal conditions. Mechanisms appear more functional than metabolic. Acquisition rate depends on dose and dose schedule. Dependence, manifested by withdrawal symptoms after as little as 7 days of THC administration, is characterized by irritability, restlessness, insomnia, anorexia, nausea, sweating, salivation, increased body temperature, altered sleep and waking EEG, tremor, and weight loss. Mild and transient in the 120 subjects studied, the syndrome was similar to sedative drug withdrawal. Tolerance to drug side effects can be useful. Tolerance to therapeutic effects or target symptoms poses problems. Clinical significance of dependence is difficult to assess since drug-seeking behavior has many determinants. Cannabis-induced super sensitivity should be considered wherever chronic drug administration is anticipated in conditions like epilepsy, glaucoma or chronic pain. Cannabis pharmacology suggests ways of minimizing tolerance and dependence problems. PMID:6271820

  3. "Infectious" Transplantation Tolerance

    NASA Astrophysics Data System (ADS)

    Qin, Shixin; Cobbold, Stephen P.; Pope, Heather; Elliott, James; Kioussis, Dimitris; Davies, Joanna; Waldmann, Herman

    1993-02-01

    The maintenance of transplantation tolerance induced in adult mice after short-term treatment with nonlytic monoclonal antibodies to CD4 and CD8 was investigated. CD4^+ T cells from tolerant mice disabled naive lymphocytes so that they too could not reject the graft. The naive lymphocytes that had been so disabled also became tolerant and, in turn, developed the capacity to specifically disable other naive lymphocytes. This process of "infectious" tolerance explains why no further immunosuppression was needed to maintain long-term transplantation tolerance.

  4. Chronic pain alters drug self-administration: implications for addiction and pain mechanisms.

    PubMed

    Martin, Thomas J; Ewan, Eric

    2008-10-01

    This review article focuses on the impact that the presence of pain has on drug self-administration in rodents, and the potential for using self-administration to study both addiction and pain, as well as their interaction. The literature on the effects of noxious input to the brain on both spinal and supraspinal neuronal activity is reviewed as well as the evidence that human and rodent neurobiology is affected similarly by noxious stimulation. The convergence of peripheral input to somatosensory systems with limbic forebrain structures is briefly discussed in the context of how the activity of one system may influence activity within the other system. Finally, the literature on how pain influences drug-seeking behaviors in rodents is reviewed, with a final discussion of how these techniques might be able to contribute to the development of novel analgesic treatments that minimize addiction and tolerance. PMID:18837632

  5. Importance of glial activation in neuropathic pain.

    PubMed

    Mika, Joanna; Zychowska, Magdalena; Popiolek-Barczyk, Katarzyna; Rojewska, Ewelina; Przewlocka, Barbara

    2013-09-15

    Glia plays a crucial role in the maintenance of neuronal homeostasis in the central nervous system. The microglial production of immune factors is believed to play an important role in nociceptive transmission. Pain may now be considered a neuro-immune disorder, since it is known that the activation of immune and immune-like glial cells in the dorsal root ganglia and spinal cord results in the release of both pro- and anti-inflammatory cytokines, as well as algesic and analgesic mediators. In this review we presented an important role of cytokines (IL-1alfa, IL-1beta, IL-2, IL-4, IL-6, IL-10, IL-15, IL-18, TNFalpha, IFNgamma, TGF-beta 1, fractalkine and CCL2); complement components (C1q, C3, C5); metaloproteinases (MMP-2,-9) and many other factors, which become activated on spinal cord and DRG level under neuropathic pain. We discussed the role of the immune system in modulating chronic pain. At present, unsatisfactory treatment of neuropathic pain will seek alternative targets for new drugs and it is possible that anti-inflammatory factors like IL-10, IL-4, IL-1alpha, TGF-beta 1 would fulfill this role. Another novel approach for controlling neuropathic pain can be pharmacological attenuation of glial and immune cell activation. It has been found that propentofylline, pentoxifylline, minocycline and fluorocitrate suppress the development of neuropathic pain. The other way of pain control can be the decrease of pro-nociceptive agents like transcription factor synthesis (NF-kappaB, AP-1); kinase synthesis (MEK, p38MAPK, JNK) and protease activation (cathepsin S, MMP9, MMP2). Additionally, since it is known that the opioid-induced glial activation opposes opioid analgesia, some glial inhibitors, which are safe and clinically well tolerated, are proposed as potential useful ko-analgesic agents for opioid treatment of neuropathic pain. This review pointed to some important mechanisms underlying the development of neuropathic pain, which led to identify some possible new approaches to the treatment of neuropathic pain, based on the more comprehensive knowledge of the interaction between the nervous system and glial and immune cells. PMID:23500198

  6. Amphibian pain and analgesia.

    PubMed

    Machin, K L

    1999-03-01

    Analgesics are often not provided to amphibians because the presence and severity of pain may not be recognized in these animals. In addition, there is little information on the mechanism of action of analgesic agents in amphibians. However, amphibians possess appropriate neurologic components for transmitting pain from peripheral receptors to the central nervous system and antinociceptive mechanisms to modulate pain. They are capable of displaying behavioral and physiologic modification of pain systems in response to analgesic pharmacologic agents. Therefore, pain perception in amphibians is likely analogous to that in mammals and invasive, potentially painful procedures should be accompanied by appropriate analgesia and anesthesia. Although specific doses have not been established in clinical trials, basic research into the mechanisms and regulation of endogenous opioid systems demonstrates the potential clinical benefit for the use of opioids in these animals. Other analgesics such as alpha2-agonists, ketamine, and tricaine methanesulfonate have also demonstrated analgesic potential. PMID:10367638

  7. [Neuromusculoskeletal chest pain].

    PubMed

    Horvat, Davor

    2003-01-01

    To determine frequency of neuromusculoskeletal etiology of chest pain is performed. By means of a retrospective analysis and on the basis of the history of the patients' disease, data were collected after chest pain had been medically worked out. The causes to chest pain were in 82% of cardial etiology, in 9% of neuromusculoskeletal etiology, in 6% of gastrointestinal etiology and 3% others. All the patients suffering from neuromusculoskeletal causes to chest pain were, besides anti-rheumatic therapy, also treated by certain form of cardiac therapy. The task of a doctor is to accurately recognize serious disorders as possible causes to chest pain. However, the doctor must not make wrong diagnosis of potentially dangerous conditions thus causing unwanted psychological and economical consequences. In order to realize this, adequate diagnostic possibilities are necessary besides the knowledge about all possible causes to chest pain. PMID:15067819

  8. Pain relief in Thailand.

    PubMed

    Spencer, Meg

    2003-01-01

    Pain is a complex problem, for both those who are enduring it and those trying to relieve it. Most people in the developed world have access to adequate treatment and management of pain, the availability of trained and educated doctors and nurses, feasible opioid prescribing policies, as well as ready access to appropriate medication. Often, this is not the case in developing countries such as Thailand. This paper is based on recent experience in the southeast of Thailand providing pain relief for persons with HIV and AIDS in Rayong Province at the Camillian Social Centre. The severity and frequency of pain endured by this group of individuals presented a daily challenge. Problems encountered in providing pain relief for these patients and some potential solutions are described. There is a lack of literature on pain relief in Thailand. PMID:15022951

  9. Neonatal pain management

    PubMed Central

    Bhalla, Tarun; Shepherd, Ed; Tobias, Joseph D.

    2014-01-01

    The past 2-3 decades have seen dramatic changes in the approach to pain management in the neonate. These practices started with refuting previously held misconceptions regarding nociception in preterm infants. Although neonates were initially thought to have limited response to painful stimuli, it was demonstrated that the developmental immaturity of the central nervous system makes the neonate more likely to feel pain. It was further demonstrated that untreated pain can have long-lasting physiologic and neurodevelopmental consequences. These concerns have resulted in a significant emphasis on improving and optimizing the techniques of analgesia for neonates and infants. The following article will review techniques for pain assessment, prevention, and treatment in this population with a specific focus on acute pain related to medical and surgical conditions. PMID:25538531

  10. Pain management in newborns.

    PubMed

    Hall, Richard W; Anand, Kanwaljeet J S

    2014-12-01

    As a standard of care for preterm/term newborns effective pain management may improve their clinical and neurodevelopmental outcomes. Neonatal pain is assessed using context-specific, validated, and objective pain methods, despite the limitations of currently available tools. Therapeutic approaches reducing invasive procedures and using pharmacologic, behavioral, or environmental measures are used to manage neonatal pain. Nonpharmacologic approaches like kangaroo care, facilitated tucking, non-nutritive sucking, sucrose, and others can be used for procedural pain or adjunctive therapy. Local/topical anesthetics, opioids, NSAIDs/acetaminophen and other sedative/anesthetic agents can be incorporated into NICU protocols for managing moderate/severe pain or distress in all newborns. PMID:25459780

  11. Tolerance in Drosophila

    PubMed Central

    Atkinson, Nigel S.

    2016-01-01

    The set of genes that underlie ethanol tolerance (inducible resistance) are likely to overlap with the set of genes responsible for ethanol addiction. Whereas addiction is difficult to recognize in simple model systems, behavioral tolerance is readily identifiable and can be induced in large populations of animals. Thus, tolerance lends itself to analysis in model systems with powerful genetics. Drosophila melanogaster has been used by a variety of laboratories for the identification of genes that interfere with the acquisition of ethanol tolerance. Here I discuss the genes identified as being important for the production of ethanol tolerance in Drosophila. Some of these genes have also been shown to be important for the production of tolerance in mammals, demonstrating that gene discovery in Drosophila has predictive value for understanding the molecular pathways that generate tolerance in mammals. PMID:19180359

  12. Taste Detection Thresholds of Resveratrol.

    PubMed

    Koga, Clarissa C; Becraft, Alexandra R; Lee, Youngsoo; Lee, Soo-Yeun

    2015-09-01

    Resveratrol is a polyphenol that is associated with numerous health benefits related to heart disease, cancer, diabetes, and neurological function. The addition of this compound to food products would help to deliver these health benefits to the consumer. However, bitterness associated with resveratrol may impart negative sensory qualities on the food products into which resveratrol is added; thus, decreasing consumer acceptability. This concern may be resolved by encapsulating resveratrol through spray drying, an innovative processing technique. The objectives of this research were to (1) compare taste detection thresholds of unencapsulated resveratrol and encapsulated resveratrol and (2) determine if the inclusion of anhydrous milk fat in the formulation of the encapsulation wall material affects the taste detection threshold of resveratrol within the microcapsules. Resveratrol microcapsules were produced by encapsulating resveratrol in a protein matrix through spray drying. R-index measure by the rating method was used to determine the average taste detection threshold and the pooled group taste detection threshold. The average and pooled group taste detection thresholds of unencapsulated resveratrol, sodium-caseinate-based resveratrol microcapsule without fat (SC), and sodium-caseinate-based resveratrol microcapsule with fat (SCAMF) were 90 and 47 mg resveratrol/L (unencapsulated), 313 and 103 mg resveratrol/L (SC), 334 and 108 mg resveratrol/L (SCAMF), respectively. The findings demonstrate that the encapsulation of resveratrol decreased the detection of the compound and provided a means to incorporate resveratrol into food products without imparting negative sensory properties. PMID:26235804

  13. Painful Peripheral Neuropathies

    PubMed Central

    Marchettini, P; Lacerenza, M; Mauri, E; Marangoni, C

    2006-01-01

    Peripheral neuropathies are a heterogeneous group of diseases affecting peripheral nerves. The causes are multiple: hereditary, metabolic, infectious, inflammatory, toxic, traumatic. The temporal profile includes acute, subacute and chronic conditions. The majority of peripheral neuropathies cause mainly muscle weakness and sensory loss, positive sensory symptoms and sometimes pain. When pain is present, however, it is usually extremely intense and among the most disabling symptoms for the patients. In addition, the neurological origin of the pain is often missed and patients receive inadequate or delayed specific treatment. Independently of the disease causing the peripheral nerve injury, pain originating from axonal pathology or ganglionopathy privileges neuropathies affecting smaller fibres, a clinical observation that points towards abnormal activity within nociceptive afferents as a main generator of pain. Natural activation of blood vessels or perineurial nociceptive network by pathology also causes intense pain. Pain of this kind, i.e. nerve trunk pain, is among the heralding symptoms of inflammatory or ischemic mononeuropathy and for its intensity represents itself a medical emergency. Neuropathic pain quality rekindles the psychophysical experience of peripheral nerves intraneural microstimulation i.e. a combination of large and small fibres sensation temporally distorted compared to physiological perception evoked by natural stimuli. Pins and needles, burning, cramping mixed with numbness, and tingling are the wording most used by patients. Nociceptive pain instead is most often described as aching, deep and dull. Good command of peripheral nerve anatomy and pathophysiology allows timely recognition of the different pain components and targeted treatment, selected according to intensity, type and temporal profile of the pain. PMID:18615140

  14. Low-back pain.

    PubMed

    Violante, Francesco S; Mattioli, Stefano; Bonfiglioli, Roberta

    2015-01-01

    Low-back pain is one of the most common painful conditions experienced by humans throughout their life. Some occupational risk factors (namely, heavy manual material handling) may also contribute to the development of low-back pain: due to the high prevalence of both low-back pain and manual material handling in the adult working population, it has been estimated that low-back pain is probably the most common occupational disorder worldwide. Lifetime prevalence of low-back pain has been reported to be as high as 84%, depending on the case definition used, and no age group is spared, even children. Although low-back pain is not a lethal condition, it was estimated at the third rank among all diseases by disability-adjusted life-years in 2010 in the USA, after ischemic heart disease and chronic obstructive pulmonary disease, and at the first rank by years lived with disability. It also ranked high (13th) globally for the same year, in disability-adjusted life-years. Low-back pain is currently classified as nonspecific/specific as to putative cause and as acute (lasting less than 6 weeks), subacute (6-12 weeks), or chronic (more than 12 weeks) according to duration of symptoms. The distinction between nonspecific/specific and acute/subacute/chronic low-back pain is useful not only for epidemiologic studies, but also (mainly) for choosing the appropriate strategy for the diagnosis and treatment of the disorder. Workplace risk factors for low-back pain include manual lifting and whole-body vibration exposure. This chapter will provide an overview of modern concepts of low-back pain (in general) and will then outline some distinctive features of work-related low-back pain. PMID:26563799

  15. Pain management and yoga.

    PubMed

    Nespor, K

    1991-01-01

    The use of yoga and yoga related techniques in pain management is reviewed and discussed. Self-awareness, relaxation, approaches which use respiration, increased self-understanding and self-acceptance, changed context of pain, increased control, life style improvements, group and social support proved beneficial. The use of yoga in pain management has its transpersonal and philosophical dimensions. Independence and self-confidence of suffering people may be protected in this way. PMID:1723397

  16. Somatization and chronic pain.

    PubMed

    Birket-Smith, M

    2001-10-01

    The experience of pain is related not only to tissue damage and physical illness, but also to mental phenomena including depression, anxiety and somatization. Somatization is common among chronic pain patients and presents special problems in management and treatment. Somatoform patients are often given inappropriate diagnoses, treated for non-existent depressive disorders, and exposed to multiple, superfluous investigations. Psychological models of chronic pain and somatization are presented, and treatment issues including psychotherapy and the use of antidepressants are discussed. PMID:11683662

  17. Relationship between cold pressor pain-sensitivity and sleep quality in opioid-dependent males on methadone treatment.

    PubMed

    Zahari, Zalina; Lee, Chee Siong; Tan, Soo Choon; Mohamad, Nasir; Lee, Yeong Yeh; Ismail, Rusli

    2015-01-01

    Aim. Poor sleep quality due to pain has been reported among opioid-dependent male patients on methadone maintenance therapy (MMT) but objective pain data are lacking. This study aimed to investigate the rate of pain-sensitivity using cold pressor test (CPT) and the relationship between pain-sensitivity and sleep quality in this population. Methods. A total of 168 male participants were included into the study. Objective pain-tolerance was evaluated at 0 h and at 24 h after the first CPT. Malay version of the Pittsburgh Sleep Quality Index (PSQI) and the subjective opiate withdrawal scale (SOWS) questionnaires were administered to evaluate the quality of sleep and withdrawal symptoms, respectively. Results. The mean age of study participants was 37.22 (SD 6.20) years old. Mean daily methadone dose was 76.64 (SD 37.63) mg/day, mean global PSQI score was 5.47 (SD 2.74) and mean averaged SOWS score was 5.43 (SD 6.91). The averaged pain-tolerance time ranged from 7 to 300 s with a mean time of 32.16 (SE 2.72) s, slightly below the cut-off score of 37.53 s. More specifically, 78.6% (n = 132) of participants were identified as pain-sensitive (averaged pain-tolerance time ≤37.53 s), and 36 (21.4%) participants were pain-tolerant (averaged pain-tolerance time >37.53 s). The pain-sensitive group reported poorer sleep quality with mean (SD) PSQI of 5.78 (2.80) compared with the pain-tolerant group with mean (SD) PSQI of 4.31 (2.18) (p = 0.005). With analysis of covariance, pain-sensitive group was found to have higher global PSQI scores (adjusted mean 5.76, 95% CI 5.29; 6.22) than pain-tolerant participants (adjusted mean 4.42, 95% CI 3.52; 5.32) (p = 0.010). Conclusions. Majority of opioid-dependent male patients on methadone treatment are pain-sensitive with CPT. Poor sleep quality is associated with cold pressor pain-sensitivity. Pain and sleep complaints in this male population should not be overlooked. PMID:25870765

  18. Relationship between cold pressor pain-sensitivity and sleep quality in opioid-dependent males on methadone treatment

    PubMed Central

    Lee, Chee Siong; Tan, Soo Choon; Mohamad, Nasir; Lee, Yeong Yeh; Ismail, Rusli

    2015-01-01

    Aim. Poor sleep quality due to pain has been reported among opioid-dependent male patients on methadone maintenance therapy (MMT) but objective pain data are lacking. This study aimed to investigate the rate of pain-sensitivity using cold pressor test (CPT) and the relationship between pain-sensitivity and sleep quality in this population. Methods. A total of 168 male participants were included into the study. Objective pain-tolerance was evaluated at 0 h and at 24 h after the first CPT. Malay version of the Pittsburgh Sleep Quality Index (PSQI) and the subjective opiate withdrawal scale (SOWS) questionnaires were administered to evaluate the quality of sleep and withdrawal symptoms, respectively. Results. The mean age of study participants was 37.22 (SD 6.20) years old. Mean daily methadone dose was 76.64 (SD 37.63) mg/day, mean global PSQI score was 5.47 (SD 2.74) and mean averaged SOWS score was 5.43 (SD 6.91). The averaged pain-tolerance time ranged from 7 to 300 s with a mean time of 32.16 (SE 2.72) s, slightly below the cut-off score of 37.53 s. More specifically, 78.6% (n = 132) of participants were identified as pain-sensitive (averaged pain-tolerance time ≤37.53 s), and 36 (21.4%) participants were pain-tolerant (averaged pain-tolerance time >37.53 s). The pain-sensitive group reported poorer sleep quality with mean (SD) PSQI of 5.78 (2.80) compared with the pain-tolerant group with mean (SD) PSQI of 4.31 (2.18) (p = 0.005). With analysis of covariance, pain-sensitive group was found to have higher global PSQI scores (adjusted mean 5.76, 95% CI 5.29; 6.22) than pain-tolerant participants (adjusted mean 4.42, 95% CI 3.52; 5.32) (p = 0.010). Conclusions. Majority of opioid-dependent male patients on methadone treatment are pain-sensitive with CPT. Poor sleep quality is associated with cold pressor pain-sensitivity. Pain and sleep complaints in this male population should not be overlooked. PMID:25870765

  19. Perioperative pain therapy in opioid abuse.

    PubMed

    Stromer, Waltraud; Michaeli, Kristina; Sandner-Kiesling, Andreas

    2013-02-01

    Opioid addiction represents an exaggerated organic and psychological comorbidity and should be regarded as a high-risk problem. Particular features seen perioperatively are tolerance, hyperalgesia and higher analgesic requirement together with physical and psychological withdrawal symptoms. Adequate pain management should have a high priority even for these patients.This review deals with the specific problems of addiction or opioid tolerance in this vulnerable patient group in the perioperative period. In this group are opioid-tolerant chronic pain patients on long-term therapy, addicts with long-term substitution therapy, those currently addicted and those with a previous history of addiction, mainly to heroin. This article intends to simplify the management of drug-dependent patients and offers strategies for perioperative analgesia that include stabilisation of physical dependency by substitution with methadone or μ-agonists; avoidance of stress; use of regional techniques in combination with non-opioids or opioids with higher doses than those used in non-addicts; avoidance of inadequate analgesic dosing; effective use of the opioid-sparing effect of different co-analgesics; and psychological support wherever appropriate.Those caring for abstinent patients should note that an inadequate dosage of analgesics can potentially reactivate addiction. After successful withdrawal of opioids and prolonged abstinence, opioid therapy can result in an exaggerated response. PMID:23241915

  20. Stimulation of the ventral tegmental area increased nociceptive thresholds and decreased spinal dorsal horn neuronal activity in rat.

    PubMed

    Li, Ai-Ling; Sibi, Jiny E; Yang, Xiaofei; Chiao, Jung-Chih; Peng, Yuan Bo

    2016-06-01

    Deep brain stimulation has been found to be effective in relieving intractable pain. The ventral tegmental area (VTA) plays a role not only in the reward process, but also in the modulation of nociception. Lesions of VTA result in increased pain thresholds and exacerbate pain in several pain models. It is hypothesized that direct activation of VTA will reduce pain experience. In this study, we investigated the effect of direct electrical stimulation of the VTA on mechanical, thermal and carrageenan-induced chemical nociceptive thresholds in Sprague-Dawley rats using our custom-designed wireless stimulator. We found that: (1) VTA stimulation itself did not show any change in mechanical or thermal threshold; and (2) the decreased mechanical and thermal thresholds induced by carrageenan injection in the hind