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Avaliação de pacientes com odontalgia atípica perante Teste Sensorial Quantitativo (QST) e Teste de Controle de Modulação da Dor (CPM); Evaluation of Patients with Atypical Odontalgia through Quantitative Sensory Testing (QST) and Controlled Pain Modulation (CPM)

Porporatti, André Luís
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/03/2013 PT
Relevância na Pesquisa
56.37%
Odontalgia Atípica (OA) é uma condição dolorosa orofacial crônica de intensidade moderada a severa, que ocorre nas estruturas dentoalveolares e na mucosa oral. É considerada de difícil diagnóstico por estar associada com a ausência de alterações clínicas e radiográficas perceptíveis. Seus aspectos patofisiológicos sensoriais e de manutenção e perpetuação da dor ainda são mal compreendidos. Os objetivos deste estudo foram: (1) avaliar as alterações somatossensoriais em pacientes com OA através dos testes sensoriais quantitativos (QST); (2) ampliar o conhecimento disponível sobre os mecanismos de modulação da dor através do teste de controle de modulação da dor (CPM); e (3) avaliar as condições psicológicas como ansiedade e depressão, qualidade do sono e qualidade de vida através de questionários auto-aplicáveis. Um total de 50 indivíduos foram incluídos, sendo 25 sujeitos do grupo sintomático com OA (19 mulheres, 58,25 +- 12,17 anos de idade) e 25 sujeitos saudáveis do grupo controle (19 mulheres, 58,92 +- 7,39 anos)(p>0.05). Os QSTs englobaram os testes de Limiar de Detecção Mecânica (MDT), Limiar de Sensibilidade Dolorosa Mecânica (PDT), Teste Mecânico de Alodinia com cotonete (DMA1) e escova dental (DMA2)...

Avaliação somatossensorial do sistema trigeminal em condições dolorosas crônicas: testes quantitativos sensoriais e limiar de percepção atual; Trigeminal system somatosensory evaluation in chronic pain patients: quantitative sensory tests and current perception threshold

Sydney, Priscila Brenner Hilgenberg
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 20/05/2013 PT
Relevância na Pesquisa
46.41%
A dor crônica envolve complexos processos de gênese e condução neural e é decorrente da ativação de mecanismos periféricos e centrais de manutenção. Muitos pacientes crônicos são refratários aos diferentes tipos de tratamento propostos, o que gera a suspeita de que de alguma maneira estes não estão sendo totalmente eficazes. O objetivo deste trabalho é avaliar os mecanismos de condução, manutenção e modulação da dor em diferentes condições dolorosas crônicas. Foram avaliadas 92 mulheres, divididas em 5 grupos: Grupo I, 20 pacientes com Dor Miofascial da musculatura mastigatória; Grupo II, 20 pacientes com Fibromialgia; Grupo III, 20 pacientes com Cefaleia Crônica Diária; Grupo IV, 12 pacientes com Neuralgia Trigeminal e Grupo V, 20 pacientes saudáveis assintomáticas. Foram aplicados dois questionários, o IDATE e o OHIP-30, para mensuração do estado ansioso e da qualidade de vida relacionada a condição dolorosa diagnosticada, respectivamente. Todas as pacientes foram submetidas a Testes Quantitativos Sensoriais, como: Limiar de Dor à Pressão, Limiar de Detecção Mecânico, Limiar Doloroso Mecânico, Tolerância à Dor Isquêmica, Sensibilidade Dolorosa ao Frio, Sensação Pós-Estímulo e Controle da Modulação da Dor. Além disso...

Prostaglandin E2 in the medial preoptic area produces hyperalgesia and activates pain-modulating circuitry in the rostral ventromedial medulla

Heinricher, M. M.; Neubert, M. J.; Martenson, M. E.; Gonçalves, Leonor
Fonte: Elsevier Ltd. Publicador: Elsevier Ltd.
Tipo: Artigo de Revista Científica
Publicado em //2004 ENG
Relevância na Pesquisa
56.06%
Prostaglandin E2 (PGE2) produced in the medial preoptic region (MPO) in response to immune signals is generally accepted to play a major role in triggering the illness response, a complex of physiological and behavioral changes induced by infection or injury. Hyperalgesia is now thought to be an important component of the illness response, yet the specific mechanisms through which the MPO acts to facilitate nociception have not been established. However, the MPO does project to the rostral ventromedial medulla (RVM), a region with a well-documented role in pain modulation, both directly and indirectly via the periaqueductal gray. To test whether PGE2 in the MPO produces thermal hyperalgesia by recruiting nociceptive modulating neurons in the RVM, we recorded the effects of focal application of PGE2 in the MPO on paw withdrawal latency and activity of identified nociceptive modulating neurons in the RVM of lightly anesthetized rats. Microinjection of a sub-pyrogenic dose of PGE2 (50 fg in 200 nl) into the MPO produced thermal hyperalgesia, as measured by a significant decrease in paw withdrawal latency. In animals displaying behavioral hyperalgesia, the PGE2 microinjection activated on-cells, RVM neurons thought to facilitate nociception...

Sex differences in endogenous pain modulation by distracting and painful conditioning stimulation

Quiton, Raimi L.; Greenspan, Joel D.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.29%
Sex differences in endogenous pain modulation were tested in healthy volunteers (32 men, 30 women). Painful contact heat stimuli were delivered to the right leg alone, and then in combination with various electrical conditioning stimuli delivered to the left forearm. Four conditioning protocols were applied to each subject in separate sessions: mild, nonpainful (control); distracting; stressful-yet-nonpainful; strongly painful. Thermal stimuli were rated on visual analog scales for pain intensity (INT) and unpleasantness (UNP). Distracting and painful conditioning stimuli significantly reduced heat pain INT and UNP ratings for both sexes, with significantly larger distraction effects on INT ratings for men than women (p=0.004). No sex differences in pain-evoked hypoalgesia were detected (p>0.05). The stress protocol did not consistently reduce heat pain ratings, possibly because the protocol was not sufficiently stressful to activate endogenous modulatory systems. Regression analysis revealed that the magnitude of pain-evoked hypoalgesia was predicted by the perceived distraction (p=0.003) and stress (p=0.04) produced by the painful conditioning stimulation, providing evidence that distraction and stress contribute to pain-evoked hypoalgesia. However...

Physical Activity, Sustained Sedentary Behavior and Pain Modulation in Women with Fibromyalgia

Ellingson, Laura D.; Shields, Morgan R.; Stegner, Aaron J.; Cook, Dane B.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.31%
Fibromyalgia (FM) has been conceptualized as a disorder of the central nervous system, characterized by augmented sensory processing and an inability to effectively modulate pain. We previously reported that physical activity (PA) is related to brain processing of pain, providing evidence for a potential mechanism of pain management. The purpose of this study was to extend our work by manipulating pain modulation and determining relationships to both PA and sustained sedentary behavior. Eleven women with FM completed accelerometer measures of PA and underwent functional magnetic resonance imaging of painful heat, administered alone and during distracting cognitive tasks. Results showed that PA was significantly (P<0.005) and positively related to brain responses during distraction from pain in regions implicated in pain modulation including the dorsolateral prefrontal cortex (DLPFC), the dorsal posterior cingulate and the periaqueducatal grey. A significant negative relationship occurred in the left anterior insula. For sedentary time, significant negative relationships were observed in areas involved in both pain modulation and the sensory-discriminative aspects of pain including the DLPFC, thalamus and superior frontal and pre and postcentral gyri. These results suggest that physical activity and sedentary behaviors are related to central nervous system regulation of pain in FM.

Abnormal endogenous pain modulation is a shared characteristic of many chronic pain conditions

Staud, Roland
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/2012 EN
Relevância na Pesquisa
46.32%
The intensity of acute and chronic pain depends on interactions between peripheral impulse input and CNS pain mechanisms, including facilitation and inhibition. Whereas tonic pain inhibition is a characteristic of most pain-free individuals, pain facilitation can be detected in many chronic pain patients. The capability to inhibit pain is normally distributed along a wide continuum in the general population and can be used to predict chronic pain. Accumulating evidence suggests that endogenous pain inhibition depends on activation of the prefrontal cortex, periaqueductal gray and rostral ventral medulla. Quantitative sensory test paradigms have been designed to acquire detailed information regarding each individual’s endogenous pain inhibition and facilitation. Such tests include: temporal summation of pain, which is mostly used to assess facilitatory pain modulation by measuring the change in pain perception during a series of identical nociceptive stimuli; and conditioned pain modulation, which tests pain inhibition by utilizing two simultaneously applied painful stimuli (the ‘pain inhibits pain’ paradigm). Considerable indirect evidence seems to indicate that not only increased pain facilitation but also ineffective pain inhibition represents a predisposition for chronic pain. This view is supported by the fact that many chronic pain syndromes (e.g....

Reduction of conditioned pain modulation in humans by naltrexone: an exploratory study of the effects of pain catastrophizing

King, Christopher D.; Goodin, Burel; Kindler, Lindsay L.; Caudle, Robert M.; Edwards, Robert R.; Gravenstein, Nikolaus; Riley, Joseph L.; Fillingim, Roger B.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.36%
The current study tested the hypothesis that conditioned pain modulation is mediated by the release of endogenous opioids with a placebo-controlled (sugar pill) study of naltrexone (50 mg) in 33 healthy volunteers over two counter-balanced sessions. Pain modulation consisted of rating of heat pain (palm) during concurrent cold water immersion (foot). Compared to baseline heat pain ratings, concurrent foot immersion lowered pain intensity ratings, which suggests an inhibitory effect, was reduced with naltrexone, suggesting at least partial dependence of inhibition on endogenous opioids. An exploratory analysis revealed that individual differences in catastrophizing moderated the effects of naltrexone; endogenous opioid blockade abolished modulation in subjects lower in catastrophizing while modulation was unaffected by naltrexone among high catastrophizers. The results suggest a role of endogenous opioids in endogenous analgesia, but hint that multiple systems might contribute to conditioned pain modulation, and that these systems might be differentially activated as a function of individual differences in responses to pain.

Personalized Pain Medicine: The Clinical Value of Psychophysical Assessment of Pain Modulation Profile

Granovsky, Yelena; Yarnitsky, David
Fonte: Rambam Health Care Campus Publicador: Rambam Health Care Campus
Tipo: Artigo de Revista Científica
Publicado em 29/10/2013 EN
Relevância na Pesquisa
56.28%
Experimental pain stimuli can be used to simulate patients’ pain experience. We review recent developments in psychophysical pain testing, focusing on the application of the dynamic tests—conditioned pain modulation (CPM) and temporal summation (TS). Typically, patients with clinical pain of various types express either less efficient CPM or enhanced TS, or both. These tests can be used in prediction of incidence of acquiring pain and of its intensity, as well as in assisting the correct choice of analgesic agents for individual patients. This can help to shorten the commonly occurring long and frustrating process of adjusting analgesic agents to the individual patients. We propose that evaluating pain modulation can serve as a step forward in individualizing pain medicine.

Reliability of subjective pain ratings and nociceptive flexion reflex responses as measures of conditioned pain modulation

Jurth, Carlo; Rehberg, Benno; von Dincklage, Falk
Fonte: Pulsus Group Inc Publicador: Pulsus Group Inc
Tipo: Artigo de Revista Científica
Publicado em //2014 EN
Relevância na Pesquisa
46.28%
Conditioned pain modulation refers to the process by which an initial painful stimulus (a ‘conditioning stimulus’) reduces the pain experienced during a test stimulus. Pain modulation can be assessed using subjective measures (eg, self-report) or objective measures (eg, measuring the nociceptive flexion reflex, a withdrawal reflex of the leg). The authors of this study aimed to test the reliability of both subjective and objective measures of pain during conditioned pain modulation.

Association of anxiety with intracortical inhibition and descending pain modulation in chronic myofascial pain syndrome

Vidor, Liliane Pinto; Torres, Iraci LS; Medeiros, Liciane Fernandes; Dussán-Sarria, Jairo Alberto; Dall’Agnol, Letizzia; Deitos, Alicia; Brietzke, Aline; Laste, Gabriela; Rozisky, Joanna R; Fregni, Felipe; Caumo, Wolnei
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.22%
Background: This study aimed to answer three questions related to chronic myofascial pain syndrome (MPS): 1) Is the motor cortex excitability, as assessed by transcranial magnetic stimulation parameters (TMS), related to state-trait anxiety? 2) Does anxiety modulate corticospinal excitability changes after evoked pain by Quantitative Sensory Testing (QST)? 3) Does the state-trait anxiety predict the response to pain evoked by QST if simultaneously receiving a heterotopic stimulus [Conditional Pain Modulation (CPM)]? We included females with chronic MPS (n = 47) and healthy controls (n = 11), aged 19 to 65 years. Motor cortex excitability was assessed by TMS, and anxiety was assessed based on the State-Trait Anxiety Inventory. The disability related to pain (DRP) was assessed by the Profile of Chronic Pain scale for the Brazilian population (B:PCP:S), and the psychophysical pain measurements were measured by the QST and CPM. Results: In patients, trait-anxiety was positively correlated to intracortical facilitation (ICF) at baseline and after QST evoked pain (β = 0.05 and β = 0.04, respectively) and negatively correlated to the cortical silent period (CSP) (β = -1.17 and β = -1.23, respectively) (P <0.05 for all comparisons). After QST evoked pain...

Modulation of Pain with Transcranial Direct Current Stimulation and Diffuse Noxious Inhibitory Controls

Reidler, Jay S.
Fonte: Harvard University Publicador: Harvard University
Tipo: Thesis or Dissertation; text Formato: application/pdf
EN
Relevância na Pesquisa
56.31%
Background: While pain is essential for physiological functioning, chronic or pathologic pain is responsible for a major burden of disease in society. Novel approaches to treating acute and chronic pain have employed neuromodulatory tools to target the central and peripheral neural structures that mediate pain. Transcranial direct current stimulation (tDCS), for example, is a safe, non-invasive brain stimulation technique that has been shown in preliminary studies to reduce chronic pain when applied to the primary motor cortex. In contrast to this exogenous neuromodulatory approach, diffuse noxious inhibitory controls (DNIC) refers to endogenous pain regulatory mechanisms that decrease pain following introduction of heterotopic noxious stimuli. This thesis explores whether combining these exogenous and endogenous pain modulation approaches synergistically increases the threshold at which pain is perceived. Methods: We conducted a double-blinded, randomized, placebo-controlled trial with a crossover design to investigate the effects of tDCS and DNIC on pain thresholds in 15 healthy human subjects. Pain thresholds were assessed prior to and following administration of active tDCS, sham tDCS, cold-water-induced DNIC, and combined active tDCS and DNIC. Using magnetic resonance spectroscopy...

Disrupted functional connectivity of the periaqueductal gray in chronic low back pain

Yu, Rongjun; Gollub, Randy L.; Spaeth, Rosa; Napadow, Vitaly; Wasan, Ajay; Kong, Jian
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
46.29%
Chronic low back pain is a common neurological disorder. The periaqueductal gray (PAG) plays a key role in the descending modulation of pain. In this study, we investigated brain resting state PAG functional connectivity (FC) differences between patients with chronic low back pain (cLBP) in low pain or high pain condition and matched healthy controls (HCs). PAG seed based functional connectivity (FC) analysis of the functional MR imaging data was performed to investigate the difference among the connectivity maps in the cLBP in the low or high pain condition and HC groups as well as within the cLBP at differing endogenous back pain intensities. Results showed that FC between the PAG and the ventral medial prefrontal cortex (vmPFC)/rostral anterior cingulate cortex (rACC) increased in cLBP patients compared to matched controls. In addition, we also found significant negative correlations between pain ratings and PAG–vmPFC/rACC FC in cLBP patients after pain-inducing maneuver. The duration of cLBP was negatively correlated with PAG–insula and PAG–amygdala FC before pain-inducing maneuver in the patient group. These findings are in line with the impairments of the descending pain modulation reported in patients with cLBP. Our results provide evidence showing that cLBP patients have abnormal FC in PAG centered pain modulation network during rest.

The neurobiology of meditation for the control of pain

Grant, Joshua A.
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
Relevância na Pesquisa
46.35%
La douleur est une expérience multidimensionnelle comportant des aspects sensoriels, émotionnels et cognitifs. Il a été montré que cette expérience peut être modulée par des facteurs psychologiques ou des interventions cognitives comme l’attention, la distraction, l’hypnose ou les attentes. La tradition orientale suggère également que la pratique de la méditation pourrait avoir des effets analgésiques. D’un point de vue théorique, plusieurs mécanismes pourraient expliquer ces effets. Cependant, très peu d’études ont testé ces hypothèses. Les études présentées dans cette thèse avaient donc pour objectif d’examiner les mécanismes analgésiques de la méditation. Dans un premier temps, une étude psychophysique a été réalisée afin de comparer les réponses à la douleur entre des adeptes de la méditation Zen et des sujets contrôles, dans différentes conditions attentionnelles. Durant la condition attentionnelle de type « mindful », les adeptes de la méditation ont présenté une plus faible sensibilité à la douleur, des réponses attentionnelles à la douleur atypiques et une diminution de la perception de la douleur associée à l’entraînement à la méditation. Une deuxième étude a été réalisée en imagerie par résonance magnétique fonctionnelle (IRMf) avec des groupes de participants similaires. Dans une condition sans méditation...

Étude des mécanismes psychophysiologiques de la modulation volontaire de la douleur par le biofeedback et la respiration.

Arsenault, Marianne
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
Relevância na Pesquisa
46.49%
Bien que la douleur soit une expérience subjective universelle, la façon de la percevoir et de l’interpréter est modulée par une multitude de facteurs. Plusieurs interventions cognitives se sont montrées efficaces pour réduire la douleur dans des conditions cliniques et expérimentales. Cette thèse s’intéressera particulièrement aux mécanismes psychophysiologiques impliqués dans les stratégies de modulation volontaire de la douleur. Ces stratégies sont intéressantes puisqu’elles encouragent une prise en charge par l’individu, lui permettant de jouer un rôle actif dans la régulation de sa douleur. La première étude s’intéresse à l’efficacité du biofeedback comme moyen de modulation volontaire de la douleur. Il s’agissait de déterminer si le fait de présenter une rétroaction de l’amplitude du réflex RIII (évoqué par une stimulation électrique du nerf sural) au cours d’un entraînement de plusieurs essais permettrait au participant d’adopter des stratégies de modulation de la douleur et d’activer volontairement des mécanismes de contrôle descendant de la douleur. De façon à évaluer spécifiquement les changements induits par le biofeedback, la modulation du réflexe RIII et de la douleur était comparée dans trois groupes (biofeedback valide...

An investigation of the emotional modulation of pain perception and neural processing in the human brainstem and spinal cord using functional magnetic resonance imaging

McIver, Theresa
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
46.44%
Pain is an extremely subjective and complex sensory and emotional experience. It is affected by a range of factors including attention, suggestion, attitude, expectation, and affective state. The influence of emotion on pain perception and neural processing is the central focus of this thesis. Previous research has demonstrated that individuals exposed to a painful stimulus will rate that stimulus as more painful when accompanied by or associated with a negative emotional influence. Conversely, pain ratings decrease when the painful stimulus is coupled with a positive emotional influence. Although many studies have confirmed that emotional manipulations affect pain perception at a group level, there has been little exploration of the range in the effect size across individuals or the psychological characteristics that may act to mediate emotional modulation of pain. Furthermore, although there is a growing body of research exploring the neural response in the brain, no other study, to date, has used functional MRI to examine the neural response across the brainstem and spinal cord involved in emotional modulation of pain. As such, this thesis used a combination of behavioural measures and functional MRI to explore differences in the effect of emotional modulation on pain perception across individuals...

Behavioral and Neural Correlates of Conditioned Pain Modulation in the Human Brainstem and Cervical Spinal Cord Using Functional Magnetic Resonance Imaging

Cotoi, ANDREEA
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
56.35%
When one noxious stimulus is coupled with a second noxious stimulus applied to a remote region of the body relative to the first stimulus, the perception of pain is reduced. This phenomenon is termed conditioned pain modulation (CPM) and it’s thought to engage descending inhibitory controls originating in the brainstem which modulate pain processing pathways, resulting in a decrease in pain. This thesis explores the CPM effect in humans, to further our understanding of pain modulation within the central nervous system (CNS). Previous research reveals that CPM evokes pain inhibition in the majority of healthy pain-free individuals, while recent studies have shown that a significant proportion of healthy individuals also demonstrate pain facilitatory responses similar to those exhibited by individuals with chronic pain. Currently, no imaging studies have exclusively explored subcortical changes in activity evoked by the CPM paradigm. Therefore, this thesis delves into uncovering the changes in the brainstem and spinal cord activity in response to the CPM paradigm by investigating the behavioral and neural responses of healthy females using functional magnetic resonance imaging (fMRI). CPM was induced by delivering a heat test stimulus to the right thenar eminence and a cold conditioning stimulus to the left thenar eminence simultaneously...

AN INVESTIGATION OF THE NEURAL CORRELATES OF COGNITIVE MODULATION OF PAIN PERCEPTION IN THE HUMAN BRAINSTEM AND CERVICAL SPINAL CORD USING FUNCTIONAL MAGNETIC RESONANCE IMAGING

Leung, Roxanne
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
46.44%
Pain is a multifaceted and malleable sensory experience that is processed at all levels of the central nervous system. It can be influenced by cognitive factors such as attention, expectation, suggestion, and attitudes; the role of attention in cognitive modulation of pain is the focus for the work that is presented in this thesis. Behavioural studies showed that pain perception was reduced under cognitive loads that place a continuous demand on executive functions such as working memory. Neuroimaging, pharmacological, and electrophysiological studies provide evidence that the underpinnings of cognitive modulation of pain involve a network of descending modulation of pain among cortical and brainstem structures. However, the role and relationship of subcortical regions in the brainstem and spinal cord (SC) during cognitive modulation of pain is not well understood. Therefore, the aim of this thesis was to confirm the behavioural effect of cognitive modulation of pain using a working memory task and to investigate the neural correlates of this modulatory mechanism in the brainstem and cervical SC using a combination of functional Magnetic Resonance Imaging (fMRI) and Structural Equation Modelling (SEM). Twelve female participants, ages 24-52...

EFFECTS OF MUSIC ON THE PAIN RESPONSE IN THE CENTRAL NERVOUS SYSTEM USING FUNCTIONAL MAGNETIC RESONANCE IMAGING

Dobek, CHRISTINE ELIZABETH
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
46.34%
The oldest procedure for pain relief has been music. There is abundant behavioural evidence to support music’s pain relieving properties, however, studies to date have yet to investigate music-induced analgesia via imaging. Our first imaging study used thermal stimulation just below pain threshold in combination with various music stimuli, to determine whether music can affect neural activity in response to heat stimuli within brainstem and spinal cord regions. Differential responses to music stimuli were found within regions known for descending modulation, and familiar classical music had a unique effect on neural activity in these regions compared to unpleasant music, reverse music, and no music. This study confirmed that the emotional valence of music affects neural activity in the brainstem and spinal cord. The second study used a well-defined pain paradigm applied with or without favorite music to study the neural activity responses in the brain, brainstem, and spinal cord using imaging. Subjective pain ratings were significantly lower when painful stimuli were administered with music than without music. The pain condition alone elicited neural activity in brain regions consistently activated during similar pain studies. Brain regions associated with pleasurable music listening were activated including limbic...

Les mécanismes endogènes de modulation de la douleur et leur dysfonction dans le syndrome de l'intestin irritable

Piché, Mathieu
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
Relevância na Pesquisa
46.43%
La douleur est une expérience subjective multidimensionnelle accompagnée de réponses physiologiques. Ces dernières sont régulées par des processus cérébraux qui jouent un rôle important dans la modulation spinale et cérébrale de la douleur. Cependant, les mécanismes de cette régulation sont encore mal définis et il est essentiel de bien les comprendre pour mieux traiter la douleur. Les quatre études de cette thèse avaient donc comme objectif de préciser les mécanismes endogènes de modulation de la douleur par la contreirritation (inhibition de la douleur par une autre douleur) et d’investiguer la dysfonction de ces mécanismes chez des femmes souffrant du syndrome de l’intestin irritable (Sii). Dans un premier temps, un modèle expérimental a été développé pour mesurer l’activité cérébrale en imagerie par résonance magnétique fonctionnelle concurremment à l’enregistrement du réflexe nociceptif de flexion (RIII : index de nociception spinale) et des réponses de conductance électrodermale (SCR : index d’activation sympathique) évoqués par des stimulations électriques douloureuses. La première étude indique que les différences individuelles d’activité cérébrale évoquée par les stimulations électriques dans les cortex orbitofrontal (OFC) et cingulaire sont associées aux différences individuelles de sensibilité à la douleur...

Modulation of nociception and pain by attention and stress

Cardinal-Aucoin, Natalie
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
Relevância na Pesquisa
46.46%
Les facteurs psychologiques tels que l'hypnose, l'émotion, le stress et l’attention exercent un effet modulant puissant sur la nociception et la douleur. Toutefois, l’influence de l'attention sur la nociception et la douleur, ainsi que les mécanismes neuronaux sous-jacents, ne sont pas clairs. La littérature actuelle sur la modulation attentionnelle des réponses spinales nociceptives, telles que mesurées par le réflexe RIII, et de la perception de l’intensité de la douleur est discordante et souvent contradictoire. Ce mémoire fournit un nouveau cadre pour examiner la modulation du réflexe RIII et de la douleur par l’attention. Une tâche de discrimination sensorielle a été décomposée en trois composantes attentionnelles : la vigilance, l’orientation, et le contrôle exécutif. Auparavant, la nature multidimensionnelle de l’attention fut largement ignorée dans la littérature. Nous démontrons que les composantes attentionnelles ont des effets modulatoires distincts sur la nociception et la douleur et suggérons que ceci représente une partie de la confusion présente dans la littérature. En prenant compte du stress indépendamment, nous démontrons, pour la première fois, que le stress inhibe la modulation attentionnelle du réflexe RIII ce qui indique une interaction et dissociation de la modulation des réponses nociceptives par l’attention et le stress. Ces résultats importants clarifient...