-
Cortex; a Journal Devoted To the Study... Aug 2022Acute and chronic states of physical pain are inherently linked to our bodily perception. Bodily illusion paradigms have demonstrated that an experimentally induced... (Clinical Trial)
Clinical Trial
Acute and chronic states of physical pain are inherently linked to our bodily perception. Bodily illusion paradigms have demonstrated that an experimentally induced sense of body disownership can modulate both acute and chronic pain. Insight into the relationship between enduring clinical alterations in body perception and pain is much more limited. The current study examined both pain perception and placebo analgesia in Body Integrity Dysphoria (BID), a clinical model of long-term alterations of bodily disownership: in its most commonly studied variant, people feel like a part of their body does not belong to them, leading to a desire for amputation of a physically healthy limb. Heat stimulations were applied before and after a placebo intervention (sham analgesic cream) to the desired and the undesired leg of 19 patients with BID with a unilateral leg amputation desire. Pain perception was assessed using pain thresholds, and ratings for pain intensity and pain unpleasantness. Results show that pain perception and placebo efficacy were lower for the undesired than for the desired leg, demonstrating a potential link between a clinical disorder of body ownership, pain perception, and placebo analgesia.
Topics: Humans; Analgesia; Illusions; Pain; Pain Management; Pain Perception; Body Integrity Identity Disorder; Placebos; Placebo Effect
PubMed: 35588553
DOI: 10.1016/j.cortex.2022.03.023 -
Sleep Medicine Reviews Dec 2022Many experimental sleep deprivation (SD) studies were conducted to clarify the causal relationship between sleep and pain. This systematic review and meta-analysis aimed... (Meta-Analysis)
Meta-Analysis Review
Many experimental sleep deprivation (SD) studies were conducted to clarify the causal relationship between sleep and pain. This systematic review and meta-analysis aimed to update the evidence regarding the effects of different experimental SD paradigms on various pain outcomes. Five databases were searched from their inception to June 2022. Separate random-effects models were used to estimate the pooled effect sizes (ES) of different experimental SD paradigms on various pain outcomes. Thirty-one studies involving 699 healthy individuals and 47 individuals with chronic pain were included. For healthy individuals, limited evidence substantiated that total SD significantly reduced pain threshold and tolerance (ES 0.74-0.95), while moderate evidence supported that partial SD significantly increased spontaneous pain intensity (ES 0.30). Very limited to moderate evidence showed that sleep fragmentation significantly increased peripheral and central sensitization in healthy individuals (ES 0.42-0.79). Further, there was very limited evidence that total or partial SD significantly aggravated spontaneous pain intensity in people with chronic pain. Our results accentuated that different SD paradigms differentially increased subjective pain intensity and worsened peripheral/central pain sensitization in healthy individuals, whereas the corresponding findings in people with chronic pain remain uncertain. Further rigorous studies are warranted to quantify their relationships in clinical populations.
Topics: Humans; Chronic Pain; Sleep Deprivation; Health Status; Pain Perception
PubMed: 36334461
DOI: 10.1016/j.smrv.2022.101695 -
Current Biology : CB Feb 2013Pain is a subjective experience that protects the body. This function implies a special relation between the brain mechanisms underlying pain perception and... (Review)
Review
Pain is a subjective experience that protects the body. This function implies a special relation between the brain mechanisms underlying pain perception and representation of the body. All sensory systems involve the body for the trivial reason that sensory receptors are located in the body. The nociceptive system of detecting noxious stimuli comprises two classes of peripheral afferents, Aδ and C nociceptors, that cover almost the entire body surface. We review evidence from experimental studies of pain in humans and other animals suggesting that Aδ skin nociceptors project to a spatially-organised, somatotopic map in the primary somatosensory cortex. While the relation between pain perception and homeostatic regulation of bodily systems is widely acknowledged, the organization of nociceptive information into spatial maps of the body has received little attention. Importantly, the somatotopic neural organization of pain systems can shed light on pain-related plasticity and pain modulation. Finally, we show that the neural coding of noxious stimuli, and consequent experience of pain, are both strongly influenced when cognitive representations of the body are activated by viewing the body, as opposed to viewing another object - an effect we term 'visual analgesia'. We argue that pain perception involves some of the representational properties of exteroceptive senses, such as vision and touch. Pain, however, has the unique feature that the content of representation is the body itself, rather than any external object of perception. We end with some suggestions regarding how linking pain to body representation could shed light on clinical conditions, notably chronic pain.
Topics: Afferent Pathways; Body Image; Brain; Humans; Mechanoreceptors; Nociception; Nociceptors; Pain; Pain Perception; Sensation; Somatosensory Cortex
PubMed: 23428330
DOI: 10.1016/j.cub.2013.01.047 -
Pain perception and physiological responses are modulated by active support from a romantic partner.Psychophysiology Sep 2023As social animals, humans are strongly affected by social bonds and interpersonal interactions. Proximity and social support from significant others may buffer the...
As social animals, humans are strongly affected by social bonds and interpersonal interactions. Proximity and social support from significant others may buffer the negative outcomes of a painful experience. Several studies have investigated the role of romantic partners' support in pain modulation, mostly focusing on tactile support and showing its effectiveness in reducing pain perception. Nevertheless, no study so far has investigated the role of supportive speaking on pain modulation, nor has compared the effects of a tactile and vocal support within the same couples. The present study directly compared for the first time the efficacy of mere presence (Passive Support) and different forms of active (Touch, Voice, Touch + Voice) support from a romantic partner during a painful experience in a naturalistic setting. We assessed pain modulation in 37 romantic couples via both subjective (self-reported ratings) and physiological (skin conductance) measurements. We found that all three types of active support were equally more effective than passive support in reducing the painful experience at both subjective and physiological levels; interestingly, our results suggest that supportive speaking can reduce pain perception with respect to passive support to a similar extent as tactile support does. Overall, this study highlights the relevance of an active support in reducing pain perception, with active types of support being more effective than passive support, regardless of its specific modality.
Topics: Humans; Pain Perception; Pain; Interpersonal Relations; Social Support; Touch Perception; Sexual Partners
PubMed: 36961121
DOI: 10.1111/psyp.14299 -
Marine Drugs Sep 2017The Conus genus includes around 500 species of marine mollusks with a peculiar production of venomous peptides known as conotoxins (CTX). Each species is able to produce... (Review)
Review
The Conus genus includes around 500 species of marine mollusks with a peculiar production of venomous peptides known as conotoxins (CTX). Each species is able to produce up to 200 different biological active peptides. Common structure of CTX is the low number of amino acids stabilized by disulfide bridges and post-translational modifications that give rise to different isoforms. µ and µO-CTX are two isoforms that specifically target voltage-gated sodium channels. These, by inducing the entrance of sodium ions in the cell, modulate the neuronal excitability by depolarizing plasma membrane and propagating the action potential. Hyperexcitability and mutations of sodium channels are responsible for perception and transmission of inflammatory and neuropathic pain states. In this review, we describe the current knowledge of µ-CTX interacting with the different sodium channels subtypes, the mechanism of action and their potential therapeutic use as analgesic compounds in the clinical management of pain conditions.
Topics: Action Potentials; Amino Acids; Animals; Conotoxins; Humans; Neuralgia; Pain Perception; Protein Processing, Post-Translational; Sodium; Voltage-Gated Sodium Channels
PubMed: 28937587
DOI: 10.3390/md15100295 -
Social Cognitive and Affective... Jul 2019Predictability has been suggested to modulate both the anticipation and perception of self-pain. Considering the overlapping neural circuits between self-pain and...
Predictability has been suggested to modulate both the anticipation and perception of self-pain. Considering the overlapping neural circuits between self-pain and other-pain perceptions, the present study investigated how the predictability of forthcoming pain modulates the anticipation and perception of self-pain and other-pain. We used a balanced, within-participant experimental design in which a visual cue indicating the recipient, intensity and predictability of an upcoming painful electrical stimulation was presented before its delivery. Subjective ratings and electroencephalography activities to the anticipation and perception of self-pain and other-pain were recorded and compared between certain and uncertain conditions. Results showed that predictability affected the perception of self-pain and other-pain in a similar manner such that the differences in behavioral ratings and event-related potentials to high-intensity and low-intensity pain were significantly reduced when the intensity was uncertain. The strengths of predictability-induced modulation of self-pain and other-pain perceptions were positively correlated with each other. Furthermore, predictability also modulated the anticipation of both self-pain and other-pain such that pre-stimulus high-frequency α-oscillation power at sensorimotor electrodes contralateral to the stimulation side was maximally suppressed when anticipating certain high-intensity pain. These findings demonstrate that predictability-induced modulation on pain anticipation and perception was similarly applied to both self-pain and other-pain.
Topics: Adult; Electric Stimulation; Electroencephalography; Evoked Potentials; Female; Humans; Male; Pain; Pain Measurement; Pain Perception; Uncertainty
PubMed: 31236566
DOI: 10.1093/scan/nsz047 -
Cephalalgia : An International Journal... Mar 2021Cyclic hormonal fluctuations influence migraine incidence and severity. Previously, we described reduced menstrual cyclicity in estradiol levels and dermal blood flow...
BACKGROUND
Cyclic hormonal fluctuations influence migraine incidence and severity. Previously, we described reduced menstrual cyclicity in estradiol levels and dermal blood flow reaction to capsaicin in female migraineurs. It is unclear whether pain perception in women with migraine is influenced by the menstrual cycle.
METHODS
Women with menstrually-related migraine (n = 14), healthy age-matched controls (n = 10) and postmenopausal women (n = 15) were asked to grade trigeminal and non-trigeminal painful stimuli on a numeric pain rating scale on menstrual cycle day 19-21 (mid-luteal) and day 1-2 (early follicular).
RESULTS
In women with menstrually-related migraine, trigeminal pain remained low throughout the cycle. Controls showed increased trigeminal pain during the mid-luteal phase compared to the early follicular phase. Changes throughout the cycle were significantly different between women with MRM and controls.
CONCLUSION
The compromised menstrual cyclicity of pain perception in women with menstrually-related migraine parallels our earlier findings on estradiol levels and dermal blood flow.
Topics: Estradiol; Female; Humans; Menstrual Cycle; Migraine Disorders; Pain; Pain Perception
PubMed: 33086876
DOI: 10.1177/0333102420966977 -
Psychosomatic Medicine Jan 2018Stress reactivity research has traditionally focused on the idea that exaggerated responses to stress may have adverse effects on health. Accumulating evidence suggests... (Review)
Review
OBJECTIVE
Stress reactivity research has traditionally focused on the idea that exaggerated responses to stress may have adverse effects on health. Accumulating evidence suggests that attenuated responses to stress and delayed recovery may also be problematic.
METHODS
This review focuses on the role of the stress response of the hypothalamic-pituitary-adrenocortical axis, the endogenous opioid system, and the cardiovascular system in hypertension, pain perception, and addictive behaviors. Results from multiple methods of assessment and stress paradigms conducted in our laboratory over the past two decades are integrated with research from other investigators and with existing theories.
RESULTS
Research indicates that exaggerated biological and physiological responses to stress and attenuated pain perception are associated with hypertension and risk for cardiovascular diseases. This research complements work linking reduced stress responses with enhanced pain sensitivity and discomfort. Multiple studies have also demonstrated that an attenuated stress response is linked to exacerbation of withdrawal symptoms and relapse in nicotine addiction. Evidence indicates important moderators (i.e., sex, personality traits, and early life adversity) and hypothalamic-pituitary-adrenocortical- and endogenous opioid system-related mechanisms in the altered response to stress. I integrate these findings in a conceptual model emphasizing that robust stress responses in the context of addiction and relapse should be considered as a marker of resiliency.
CONCLUSIONS
A blunted stress response may indicate long-term physiological dysregulation that could usher harmful consequences for cardiovascular disease, pain perception, and addictive disorders. The impact of dysregulation is influenced by multiple individual and situational factors that should be considered in evaluating the clinical significance of stress response dysregulation.
Topics: Behavior, Addictive; Cardiovascular Diseases; Humans; Pain Perception; Resilience, Psychological; Stress, Psychological; Tobacco Use Disorder
PubMed: 28834923
DOI: 10.1097/PSY.0000000000000520 -
Dental Press Journal of Orthodontics May 2019Various types of separators have been advocated, but the ideal separator should produce optimum separation with minimal pain and discomfort. (Randomized Controlled Trial)
Randomized Controlled Trial
INTRODUCTION
Various types of separators have been advocated, but the ideal separator should produce optimum separation with minimal pain and discomfort.
OBJECTIVE
The objective of this study was to evaluate and compare the amount of separation achieved by three different types of separators (Elastomeric, Kesling and Kansal), and to assess the associated pain and discomfort.
METHODS
A random single-blind split-mouth study was conducted on 108 patients seeking fixed orthodontic treatment, in which two different separators were used on each side in both the arches for a single patient. After five days, the amount of separation was measured with a feeler gauge. Visual Analogue Scale (VAS) scoring was performed by the patient on each day, to evaluate pain perception. Discomfort was evaluated by questionnaire filled by the patient at the time of separator removal.
RESULTS
The greatest amount of separation was seen with the elastomeric separators, while the smallest separation was seen with Kansal separators. VAS scoring showed maximum pain at day 1 with all the three separator types. Highest pain was perceived in the Elastomeric separators group, followed by Kesling and Kansal separators, respectively. Statistically significant difference was found in VAS score of Elastomeric separators, when compared to both Kesling and Kansal, on day 1 and 2 (p= 0.001). Analysis of the questionnaires revealed that a greater number of patients experienced discomfort with elastomeric separators placement (69.4%), which was statistically significant (p< 0.01) when compared to the other two types of separators. Answers to the other questions were comparable, except for the need for medications, which was reportedly highest with elastomeric separators.
CONCLUSION
Kesling separators produce adequate separation with minimal discomfort and pain, compared to Elastomeric and Kansal separators.
Topics: Humans; Orthodontic Appliances; Pain; Pain Measurement; Pain Perception; Single-Blind Method
PubMed: 31116286
DOI: 10.1590/2177-6709.24.2.042-048.oar -
Neuroscience Bulletin Apr 2016An increasing body of neuroimaging and electrophysiological studies of the brain suggest that the insular cortex (IC) integrates multimodal salient information ranging... (Review)
Review
An increasing body of neuroimaging and electrophysiological studies of the brain suggest that the insular cortex (IC) integrates multimodal salient information ranging from sensation to cognitive-affective events to create conscious interoception. Especially with regard to pain experience, the IC has been supposed to participate in both sensory-discriminative and affective-motivational aspects of pain. In this review, we discuss the latest data proposing that subregions of the IC are involved in isolated pain networks: the posterior sensory circuit and the anterior emotional network. Due to abundant connections with other brain areas, the IC is likely to serve as an interface where cross-modal shaping of pain occurs. In chronic pain, however, this mode of emotional awareness and the modulation of pain are disrupted. We highlight some of the molecular mechanisms underlying the changes of the pain modulation system that contribute to the transition from acute to chronic pain in the IC.
Topics: Cerebral Cortex; Chronic Pain; Discrimination, Psychological; Emotions; Humans; Neural Pathways; Pain Perception
PubMed: 26898298
DOI: 10.1007/s12264-016-0016-y