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European Journal of Pain (London,... Nov 2022The mechanisms of pain perception in individuals with masochistic behaviour (MB) remain poorly documented. We hypothesized that MB is associated with context-specific...
BACKGROUND
The mechanisms of pain perception in individuals with masochistic behaviour (MB) remain poorly documented. We hypothesized that MB is associated with context-specific changes in descending pain modulation.
METHODS
We compared the effects of four standardized sets of images with positive (erotic), negative (mutilations), masochistic or neutral emotional valences on the RIII nociceptive reflex evoked by electrical stimulation of the sural nerve and recorded on the ipsilateral biceps femoris in 15 controls and 15 men routinely engaging in MB. We systematically assessed the RIII reflex threshold and recruitment curves (up to the tolerance threshold), thermal (heat and cold) pain thresholds measured on the upper and lower limbs and responses to the pain sensitivity questionnaire, to compare basal pain perception between our two groups of participants. We also assessed anxiety, depression, empathy, alexithymia, high sensation seeking and catastrophizing, to investigate their potential influence on the emotional modulation of pain.
RESULTS
Thermal pain thresholds, RIII reflex recruitment curves, and responses to the psychological and pain sensitivity questionnaires were similar in the two groups. Neutral, positive and negative images modulated the RIII reflex similarly in the two groups. By contrast, masochistic images induced a significant (p < 0.01) decrease in RIII reflex responses in subjects with MB, whereas it tended to increase these responses in control subjects.
CONCLUSIONS
Our data suggest that psychological profile, basal pain sensitivity and the emotional modulation of pain are normal in individuals with MB but that these subjects selectively engage descending pain inhibition in the masochistic context.
SIGNIFICANCE
Decrease pain perception related to masochistic behaviours is associated with specific activation of descending pain inhibition.
Topics: Electric Stimulation; Humans; Male; Pain; Pain Perception; Pain Threshold; Reflex
PubMed: 36094743
DOI: 10.1002/ejp.2037 -
Psychiatria Danubina 2023Pain is one of the basic defense responses of living organisms. Although the threshold for pain perception varies from person to person, there is no doubt that pain... (Review)
Review
INTRODUCTION
Pain is one of the basic defense responses of living organisms. Although the threshold for pain perception varies from person to person, there is no doubt that pain reduces a person's quality of life. Assessing the subjective experience of pain is especially important in the treatment of patients with schizophrenia. In light of recent advances in neuroscience, we discuss pain thresholds in patients with schizophrenia.
METHODS
A narrative review of pain thresholds in patients with schizophrenia was conducted. We electronically searched the PubMed and Google Scholar databases for articles in English with "pain," "schizophrenia," "neural circuits," and "neurotransmitters" in the title or abstract, for the period January 2000 through June 2022.
RESULTS
A seemingly contradictory phenomenon has been noted with regard to pain thresholds in patients with schizophrenia. One phenomenon is a high pain threshold for nociceptive stimuli, and the other is a low pain threshold in chronic pain. As a result, a pain threshold paradox has been observed.
CONCLUSIONS
Many schizophrenia patients appear to have an excess of dopamine in the mesolimbic system, which stimulates both the descending pain inhibitory pathway and the salience network. As a result, a pain threshold paradox has been observed, in which the threshold for acute nociceptive pain is high and the threshold for chronic pain is low.
Topics: Humans; Pain Threshold; Chronic Pain; Quality of Life; Schizophrenia; Pain Perception
PubMed: 37480304
DOI: 10.24869/psyd.2023.174 -
Pain Jun 2016The "gate control theory of pain" of 1965 became famous for integrating clinical observations and the understanding of spinal dorsal horn circuitry at that time into a... (Review)
Review
The "gate control theory of pain" of 1965 became famous for integrating clinical observations and the understanding of spinal dorsal horn circuitry at that time into a testable model. Although it became rapidly clear that spinal circuitry is much more complex than that proposed by Melzack and Wall, their prediction of the clinical efficacy of transcutaneous electrical nerve stimulation and spinal cord stimulation has left an important clinical legacy also 50 years later. In the meantime, it has been recognized that the sensitivity of the nociceptive system can be decreased or increased and that this "gain control" can occur at peripheral, spinal, and supraspinal levels. The resulting changes in pain sensitivity can be rapidly reversible or persistent, highly localized or widespread. Profiling of spatio-temporal characteristics of altered pain sensitivity (evoked pain to mechanical and/or heat stimuli) allows implications on the mechanisms likely active in a given patient, including peripheral or central sensitization, intraspinal or descending inhibition. This hypothesis generation in the diagnostic process is an essential step towards a mechanism-based treatment of pain. The challenge now is to generate the rational basis of multimodal pain therapy algorithms by including profile-based stratification of patients into studies on efficacy of pharmacological and nonpharmacological treatment modalities. This review outlines the current evidence base for this approach.
Topics: Animals; Humans; Nociception; Nociceptors; Pain; Pain Measurement; Pain Threshold; Spinal Cord
PubMed: 26817644
DOI: 10.1097/j.pain.0000000000000499 -
Georgian Medical News Feb 2022The phenomenon of pain remains one of the most important challenges in medicine and biology, which often causes disability in humans and worsens the quality of life. The...
The phenomenon of pain remains one of the most important challenges in medicine and biology, which often causes disability in humans and worsens the quality of life. The pain is a variable, subjective experience, and it is impossible to fully understand it without getting to know the physiological mechanisms beyond sensory damage of the tissues. There are some gender differences in pain perception, particularly, females tend to be more sensitive towards experimental pain. Interestingly, the observed data is consistent for males throughout life, but as for females, parameters vary according to the age and ovarian-menstrual cycle (OMC) phases. Study aims to assess correlation between pain perception and indices of hostility in males and females (in the follicular phase of OMC cycle). The sample of this study included volunteer students, ages 18 to 23. The main selection criterium for participants was their health state; Those without chronic pain, excess body weight (assessed by BMI), cardiovascular, respiratory, endocrine, etc. disorders were selected for participation in the study. Prior to the start of the study, participants were given information about their rights and written informed consent was obtained. Participants were informed that they could refuse to take part in the study at any stage. All procedures and protocol of the study were approved by Tbilisi State Medical University Biomedical Research Committee. The study was conducted in compliance with all requirements and regulations of International Pain Association for biomedical observation and experiments. Ovarian-menstrual cycle of the women participating in the research were evaluated using relevant questionnaires. All experiments were performed in the follicular phase of menstrual cycle (7-11 days of the cycle). At this stage, study was conducted in starvation state- 10-12 hours after the last meal. According to our experiment, the findings about gender differences of psychologic parameters and their linkage to heat and cold sensitivity coincides with previous study results, where pain threshold and tolerance to the pain are positively correlated with high degree of assault. Our findings demonstrate that pain perception by humans, besides intensity of nociceptive stimuli, depends on psychophysiologic parameters. The findings correlate with the data from previous studies, particularly to the idea, that negative emotions and different types of assault define individual correlates of pain perception, pain threshold and tolerance to the pain. It is quite clear that further research is warranted in order to make evidence-based statements and recommendations for clinical practice, including treatment protocols for pain management. It is quite possible, that in near future, assessing psychoemotional condition will be one of the most important tools in pain management. Besides, by evaluating psychoemotional parameters, it may become possible to predict the probability of progressing acute pain into chronic pain, which will be essential predictive information to decrease the risk of disease chronization.
Topics: Adolescent; Adult; Chronic Pain; Female; Hostility; Humans; Male; Pain Perception; Pain Threshold; Quality of Life; Young Adult
PubMed: 35271474
DOI: No ID Found -
Medicine and Science in Sports and... Feb 2022Exercise-induced hypoalgesia is frequently documented in the literature. However, the underlying neural mechanism of this phenomenon remains unclear. Here, we explored... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
Exercise-induced hypoalgesia is frequently documented in the literature. However, the underlying neural mechanism of this phenomenon remains unclear. Here, we explored the effects of different intensities of isometric exercise on pain perception with a randomized controlled design and investigated its neural mechanisms through tracing the dynamic changes of heat-evoked brain responses.
METHODS
Forty-eight participants were randomly assigned to one of the three groups with different exercise intensities (i.e., high, low, and control). Their subjective pain reports and brain responses elicited by heat stimuli before and after exercise were assessed.
RESULTS
We observed 1) the increased pressure pain thresholds and heat pain thresholds on the dorsal surface of the hand and the biceps brachii muscle of the exercised limb (closed to the contracting muscle), and the decreased pressure pain ratings at the indexed finger of the unexercised limb; 2) more reduction of pain sensitivity on both the biceps brachii muscle and the dorsal surface of the hand induced by the high-intensity isometric exercise than the low-intensity isometric exercise; and 3) both the high-intensity and the low-intensity isometric exercise induced the reduction of N2 amplitudes and N2-P2 peak-to-peak amplitudes, as well as the reduction of event-related potential magnitudes elicited by the heat stimuli on the exercised limb.
CONCLUSIONS
The hypoalgesic effects induced by the isometric exercise were not only localized to the moving part of the body but also can be extended to the distal part of the body. The exercise intensities play a vital role in modulating these effects. Exercise-induced hypoalgesia could be related to the modulation of nociceptive information transmission via a spinal gating mechanism and also rely on a top-down descending pain inhibitory mechanism.
Topics: Adolescent; Adult; Exercise; Female; Humans; Male; Pain Measurement; Pain Perception; Pain Threshold; Young Adult
PubMed: 34468414
DOI: 10.1249/MSS.0000000000002781 -
Clinical and Experimental Rheumatology Jun 2022Fibromyalgia (FM) is associated with central pain sensitisation, autonomic alterations and neuropathy in small nerve fibres. This study aimed to analyse the association...
OBJECTIVES
Fibromyalgia (FM) is associated with central pain sensitisation, autonomic alterations and neuropathy in small nerve fibres. This study aimed to analyse the association between tonic sweating and central pain sensitisation in FM.
METHODS
Fifty-eight FM patients and thirty healthy women were assessed in terms of slowly repeated evoked pain (SREP), as a measure of central sensitisation. Sweating was evaluated by skin conductance (SC), as a sympathetic autonomic measure secondarily indexing possible small nerve fibre peripheral neuropathy. Clinical and psychological factors were evaluated through questionnaire measures.
RESULTS
FM patients displayed smaller SC values than healthy controls, and SREP sensitisation was only observed in FM patients. Pain threshold and tolerance were also lower in the patient sample. Clinical symptoms (pain, fatigue, insomnia) only correlated significantly with SREP sensitisation. SC was inversely related to SREP sensitisation, and this association persisted after statistically controlling for levels of catastrophising and antidepressant use.
CONCLUSIONS
These results suggest that central pain sensitisation, proposed as a main pathophysiological mechanism of FM, may depend on sympathetic autonomic deficiencies, suggestive of small nerve fibres neuropathy. Future studies should aim to replicate these results using other central pain sensitisation measures and direct measures of neuropathy or small nerve fibre density.
Topics: Central Nervous System Sensitization; Female; Fibromyalgia; Humans; Pain; Pain Measurement; Pain Threshold
PubMed: 35748717
DOI: 10.55563/clinexprheumatol/n280oi -
Behavior Research Methods Apr 2024We introduce the Denver Pain Authenticity Stimulus Set (D-PASS), a free resource containing 315 videos of 105 unique individuals expressing authentic and posed pain. All...
We introduce the Denver Pain Authenticity Stimulus Set (D-PASS), a free resource containing 315 videos of 105 unique individuals expressing authentic and posed pain. All expressers were recorded displaying one authentic (105; pain was elicited via a pressure algometer) and two posed (210) expressions of pain (one posed expression recorded before [posed-unrehearsed] and one recorded after [posed-rehearsed] the authentic pain expression). In addition to authentic and posed pain videos, the database includes an accompanying codebook including metrics assessed at the expresser and video levels (e.g., Facial Action Coding System metrics for each video controlling for neutral images of the expresser), expressers' pain threshold and pain tolerance values, averaged pain detection performance by naïve perceivers who viewed the videos (e.g., accuracy, response bias), neutral images of each expresser, and face characteristic rating data for neutral images of each expresser (e.g., attractiveness, trustworthiness). The stimuli and accompanying codebook can be accessed for academic research purposes from https://digitalcommons.du.edu/lsdl_dpass/1/ . The relatively large number of stimuli allow for consideration of expresser-level variability in analyses and enable more advanced statistical approaches (e.g., signal detection analyses). Furthermore, the large number of Black (n = 41) and White (n = 56) expressers permits investigations into the role of race in pain expression, perception, and authenticity detection. Finally, the accompanying codebook may provide pilot data for novel investigations in the intergroup or pain sciences.
Topics: Humans; Male; Facial Expression; Female; Adult; Pain; Young Adult; Pain Threshold; Video Recording; Pain Measurement; Adolescent; Photic Stimulation
PubMed: 37993672
DOI: 10.3758/s13428-023-02283-2 -
Neuroscience and Biobehavioral Reviews Aug 2022All studies that investigated personal factors influencing pressure pain threshold (PPT) in healthy people were synthesized. Data was summarized, and risk of bias (RoB)... (Meta-Analysis)
Meta-Analysis Review
All studies that investigated personal factors influencing pressure pain threshold (PPT) in healthy people were synthesized. Data was summarized, and risk of bias (RoB) and level of evidence were determined. Results were pooled per influencing factor, grouped by body region and included in meta-analyses. Fifty-four studies were eligible. Five had low, nine moderate, and 40 high RoB. Following meta-analyses, a strong conclusion was found for the influence of scapular position, a moderate for the influence of gender, and a weak for the influence of age (shoulder/arm region) and blood pressure on PPT. In addition, body mass index, gender (leg region), alcohol consumption and pain vigilance may not influence PPT. Based on qualitative summary, depression and menopause may not influence PPT. For other variables there was only preliminary or conflicting evidence. However, caution is advised, since the majority of included studies showed a high RoB and several were not eligible to include in meta-analyses. Heterogeneity was high in the performed meta-analyses, and most conclusions were weak. More standardized research is necessary.
Topics: Bias; Female; Humans; Pain; Pain Measurement; Pain Threshold
PubMed: 35697160
DOI: 10.1016/j.neubiorev.2022.104727 -
Pain Medicine (Malden, Mass.) Mar 2017The purpose of this study was to examine psychosocial influences on exercise-induced hypoalgesia (EIH). (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
The purpose of this study was to examine psychosocial influences on exercise-induced hypoalgesia (EIH).
DESIGN
Randomized controlled trial.
SETTING
Clinical research unit in a hospital.
SUBJECTS
Fifty-eight healthy men and women (mean age = 21 ± 3 years) participated in this study.
METHODS
Participants were first asked to complete a series of baseline demographic and psychological questionnaires including the Pain Catastrophizing Scale, the Fear of Pain Questionnaire, and the Family Environment Scale. Following this, they were familiarized with both temporal summation of heat pain and pressure pain testing protocols. During their next session, participants completed the Profile of Mood States, rated the intensity of heat pulses, and indicated their pressure pain thresholds and ratings before and after three minutes of submaximal, isometric exercise. Situational catastrophizing was assessed at the end of the experimental session.
RESULTS
Results indicated that experimental pain sensitivity was significantly reduced after exercise ( P < 0.05). Men and women did not differ on any of the measured psychosocial variables ( P > 0.05). Positive family environments predicted attenuated pain sensitivity and greater EIH, whereas negative and chronic pain-present family environments predicted worse pain and EIH outcomes. Situational catastrophizing and negative mood state also predicted worse pain and EIH outcomes and were additionally associated with increased ratings of perceived exertion and muscle pain during exercise.
CONCLUSIONS
This study provides preliminary evidence that psychosocial variables, such as the family environment and mood states, can affect both pain sensitivity and the ability to modulate pain through exercise-induced hypoalgesia.
Topics: Exercise; Female; Humans; Male; Naltrexone; Narcotic Antagonists; Pain; Pain Threshold; Psychology; Young Adult
PubMed: 28034985
DOI: 10.1093/pm/pnw275 -
Applied Psychophysiology and Biofeedback Dec 2021To understand the variable response to pain, researchers have examined the change in cardiovascular measures to a uniform painful stimulation. Pain catastrophizing is...
To understand the variable response to pain, researchers have examined the change in cardiovascular measures to a uniform painful stimulation. Pain catastrophizing is the tendency to magnify or exaggerate pain sensations, and it affects the outcome of rehabilitation in a clinical setting. Its effect on cardiovascular changes during a painful stimulus is unclear. Twenty-four healthy human participants completed the study. All participants completed a cold pressor test while subjective pain intensity was measured with a numeric pain scale from 0-10. Continuous cardiac output measurements were obtained with finger-pulse plethysmograph waveform analysis. The measurements included systolic and diastolic blood pressure, heart rate averaged over 30 s intervals. Pain catastrophizing and anxiety were assessed using the pain catastrophizing scale (PCS), and Spielberger's State-Trait Anxiety Inventories, respectively. Peak pain was correlated to pain catastrophizing (r = 0.628, p < 0.01). There was a strong correlation between change in heart rate (HR) and subjective peak pain (r = 0.805, p < 0.01), total PCS (r = 0.474, p < 0.05), and the helplessness subscale of the PCS (r = 0.457, p < 0.05). Peak pain and catastrophizing explained a significant amount of the variance for the change in HR during the cold pressor test (R of 0.649 and 0.224 respectively, p = 0.019). These novel findings demonstrate a psycho-physiological relationship between cardiovascular changes and pain catastrophizing. Further research should include participants with subacute or persistent pain.
Topics: Catastrophization; Cold Temperature; Heart Rate; Humans; Pain; Pain Measurement; Pain Threshold
PubMed: 34453652
DOI: 10.1007/s10484-021-09520-4