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Neurophysiologie Clinique = Clinical... Oct 2014We here review behavioral, neuroimaging and electrophysiological studies of hypnosis as a state, as well as hypnosis as a tool to modulate brain responses to painful... (Review)
Review
We here review behavioral, neuroimaging and electrophysiological studies of hypnosis as a state, as well as hypnosis as a tool to modulate brain responses to painful stimulations. Studies have shown that hypnotic processes modify internal (self awareness) as well as external (environmental awareness) brain networks. Brain mechanisms underlying the modulation of pain perception under hypnotic conditions involve cortical as well as subcortical areas including anterior cingulate and prefrontal cortices, basal ganglia and thalami. Combined with local anesthesia and conscious sedation in patients undergoing surgery, hypnosis is associated with improved peri- and postoperative comfort of patients and surgeons. Finally, hypnosis can be considered as a useful analogue for simulating conversion and dissociation symptoms in healthy subjects, permitting better characterization of these challenging disorders by producing clinically similar experiences.
Topics: Brain; Humans; Hypnosis; Hysteria; Nerve Net; Pain Perception
PubMed: 25306075
DOI: 10.1016/j.neucli.2013.09.006 -
Pain Management 2015Pain is a significant national burden in terms of patient suffering, expenditure and lost productivity. Understanding pain is fundamental to improving evaluation,... (Review)
Review
Pain is a significant national burden in terms of patient suffering, expenditure and lost productivity. Understanding pain is fundamental to improving evaluation, treatment and innovation in the management of acute and persistent pain syndromes. Pain perception begins in the periphery, and then ascends in several tracts, relaying at different levels. Pain signals arrive in the thalamus and midbrain structures which form the pain neuromatrix, a constantly shifting set of networks and connections that determine conscious perception. Several cortical regions become active simultaneously during pain perception; activity in the cortical pain matrix evolves over time to produce a complex pain perception network. Dysfunction at any level has the potential to produce unregulated, persistent pain.
Topics: Analgesia; Brain; Chronic Pain; Humans; Nociception; Pain; Pain Perception; Pain Threshold; Peripheral Nervous System; Spinal Cord; Visceral Pain
PubMed: 26088531
DOI: 10.2217/pmt.15.27 -
Pain Jun 2017Breathing techniques are commonly used to alleviate pain. Despite their frequent use, surprisingly little is known about their efficacy as well as their underlying... (Review)
Review
Breathing techniques are commonly used to alleviate pain. Despite their frequent use, surprisingly little is known about their efficacy as well as their underlying physiological mechanisms. The purpose of this systematic review is to summarize and critically appraise the results of existing studies on the association between respiration and pain, and to highlight a potential physiological mechanism underlying the respiration-pain connection. A total of 31 publications from between 1984 and 2015 were retrieved and analyzed. These articles were classified into 4 groups: experimental and clinical studies of the effect of pain on respiration, clinical studies of the effects of breathing techniques on pain, and experimental studies of the influence of various forms of respiration on laboratory-induced pain. The findings suggest that pain influences respiration by increasing its flow, frequency, and volume. Furthermore, paced slow breathing is associated with pain reduction in some of the studies, but evidence elucidating the underlying physiological mechanisms of this effect is lacking. Here, we focus on the potential role of the cardiovascular system on the respiratory modulation of pain. Further research is definitely warranted.
Topics: Animals; Breathing Exercises; Evidence-Based Medicine; Humans; Models, Biological; Pain Perception; Respiratory Mechanics; Treatment Outcome
PubMed: 28240995
DOI: 10.1097/j.pain.0000000000000865 -
Neuron Aug 2015Recent neuroimaging studies suggest that the brain adapts with pain, as well as imparts risk for developing chronic pain. Within this context, we revisit the concepts... (Review)
Review
Recent neuroimaging studies suggest that the brain adapts with pain, as well as imparts risk for developing chronic pain. Within this context, we revisit the concepts for nociception, acute and chronic pain, and negative moods relative to behavior selection. We redefine nociception as the mechanism protecting the organism from injury, while acute pain as failure of avoidant behavior, and a mesolimbic threshold process that gates the transformation of nociceptive activity to conscious pain. Adaptations in this threshold process are envisioned to be critical for development of chronic pain. We deconstruct chronic pain into four distinct phases, each with specific mechanisms, and outline current state of knowledge regarding these mechanisms: the limbic brain imparting risk, and the mesolimbic learning processes reorganizing the neocortex into a chronic pain state. Moreover, pain and negative moods are envisioned as a continuum of aversive behavioral learning, which enhance survival by protecting against threats.
Topics: Affect; Animals; Avoidance Learning; Brain; Humans; Nociception; Pain; Pain Perception
PubMed: 26247858
DOI: 10.1016/j.neuron.2015.06.005 -
European Journal of Obstetrics,... Apr 2022Endometriosis is a painful, chronic inflammatory disorder that is difficult to treat. Studies have suggested that diet may have a therapeutic effect on chronic... (Review)
Review
INTRODUCTION
Endometriosis is a painful, chronic inflammatory disorder that is difficult to treat. Studies have suggested that diet may have a therapeutic effect on chronic inflammation. However, only limited information is available regarding the impact of diet on pain perception in relation to endometriosis. As such, the aim of this review was to evaluate if diet has any impact on pain perception in women suffering from endometriosis.
MATERIALS AND METHODS
A systematic review was conducted by searching Medline and Embase to identify randomized controlled trials and observational studies adhering to the PRISMA and SWiM guidelines. A table summarizing the findings was developed using the GRADE approach. Inclusion criteria were: women of reproductive age; laparoscopically confirmed diagnosis of endometriosis; and intervention including any type of dietary change. This review was registered with PROSPERO on 14 November 2020 (CRD42020212314).
RESULTS
In total, the database search identified 2185 studies; of these, six studies fulfilled the inclusion criteria. The Newcastle-Ottawa scale and the Cochrane tool were used to assess the studies, which were concluded to be of high quality and to have low risk of bias. All studies had a positive impact on pain perception, with all except one study reporting a significant reduction in pain perception, indicating that high intake of polyunsaturated fatty acids, a gluten-free diet and a low nickel diet may improve painful endometriosis. It was not possible to conduct a meta-analysis due to considerable heterogeneity amongst the included studies due to differences in dietary adherence, dietary therapies, outcome measurements, populations, durations and study designs.
CONCLUSION
All studies found that diet had a positive impact on pain perception among women with endometriosis. However, the majority of available evidence on dietary interventions in relation to endometriosis-associated pain was derived from non-randomized controlled trials, which have multiple sources of bias. Therefore, further studies are needed to investigate diet and its effect on pain perception in women with endometriosis.
Topics: Diet; Endometriosis; Female; Humans; Pain; Pain Perception
PubMed: 35245715
DOI: 10.1016/j.ejogrb.2022.02.028 -
Seminars in Fetal & Neonatal Medicine Aug 2019Premature infants hospitalized after birth are exposed to repeated painful procedures as part of their routine medical care. Early neonatal exposure to unmanaged pain... (Review)
Review
Premature infants hospitalized after birth are exposed to repeated painful procedures as part of their routine medical care. Early neonatal exposure to unmanaged pain has been linked to numerous negative long-term outcomes, such as the development of pain hypersensitivity, detrimental psychological symptomology, and altered neurodevelopment. These findings emphasize the crucial role of pain management in neonatal care. The aim of this article is to give an overview of evidence-based non-pharmacological pain management techniques for hospitalized neonates. Research supporting the effectiveness of various proximal, distal, and procedural pain management methods in neonates will be presented. Additionally, understanding the larger biopsychosocial context of the infant that underpins the mechanisms of these pain management methods is essential. Therefore, two important models that inform non-pharmacological approaches to infant pain management (DIAPR-R [The Development of Infant Acute Pain Responding-Revised], Attachment Theory) will be discussed.
Topics: Caregivers; Humans; Infant Behavior; Infant, Newborn; Intensive Care Units, Neonatal; Nociception; Object Attachment; Pain Management; Pain Perception
PubMed: 31326301
DOI: 10.1016/j.siny.2019.05.009 -
Nature Neuroscience Jul 2020General anesthesia (GA) can produce analgesia (loss of pain) independent of inducing loss of consciousness, but the underlying mechanisms remain unclear. We hypothesized...
General anesthesia (GA) can produce analgesia (loss of pain) independent of inducing loss of consciousness, but the underlying mechanisms remain unclear. We hypothesized that GA suppresses pain in part by activating supraspinal analgesic circuits. We discovered a distinct population of GABAergic neurons activated by GA in the mouse central amygdala (CeA neurons). In vivo calcium imaging revealed that different GA drugs activate a shared ensemble of CeA neurons. CeA neurons also possess basal activity that mostly reflects animals' internal state rather than external stimuli. Optogenetic activation of CeA potently suppressed both pain-elicited reflexive and self-recuperating behaviors across sensory modalities and abolished neuropathic pain-induced mechanical (hyper-)sensitivity. Conversely, inhibition of CeA activity exacerbated pain, produced strong aversion and canceled the analgesic effect of low-dose ketamine. CeA neurons have widespread inhibitory projections to many affective pain-processing centers. Our study points to CeA as a potential powerful therapeutic target for alleviating chronic pain.
Topics: Anesthetics, General; Animals; Central Amygdaloid Nucleus; Female; GABAergic Neurons; Male; Mice; Neural Pathways; Pain; Pain Perception
PubMed: 32424286
DOI: 10.1038/s41593-020-0632-8 -
Nature Neuroscience May 2023A painful episode can lead to a life-long increase in an individual's experience of pain. Fearful anticipation of imminent pain could play a role in this phenomenon, but...
A painful episode can lead to a life-long increase in an individual's experience of pain. Fearful anticipation of imminent pain could play a role in this phenomenon, but the neurobiological underpinnings are unclear because fear can both suppress and enhance pain. Here, we show in mice that long-term associative fear memory stored in neuronal engrams in the prefrontal cortex determines whether a painful episode shapes pain experience later in life. Furthermore, under conditions of inflammatory and neuropathic pain, prefrontal fear engrams expand to encompass neurons representing nociception and tactile sensation, leading to pronounced changes in prefrontal connectivity to fear-relevant brain areas. Conversely, silencing prefrontal fear engrams reverses chronically established hyperalgesia and allodynia. These results reveal that a discrete subset of prefrontal cortex neurons can account for the debilitating comorbidity of fear and chronic pain and show that attenuating the fear memory of pain can alleviate chronic pain itself.
Topics: Mice; Animals; Chronic Pain; Memory, Long-Term; Fear; Brain; Prefrontal Cortex; Hyperalgesia; Pain Perception
PubMed: 37024573
DOI: 10.1038/s41593-023-01291-x -
Acta Obstetricia Et Gynecologica... Sep 2021Endometriosis is challenging to treat. It is a painful and chronic inflammatory disorder that impacts up to 10% of women of reproductive age. Despite available surgical...
INTRODUCTION
Endometriosis is challenging to treat. It is a painful and chronic inflammatory disorder that impacts up to 10% of women of reproductive age. Despite available surgical and medical treatment options, recurrence of symptoms is common. Available studies suggest that exercise may have a therapeutic effect on chronic inflammation and thereby on pain perception. This review evaluates whether exercise can decrease pain perception in women with symptomatic endometriosis.
MATERIAL AND METHODS
This systematic review was conducted according to PRISMA by searching databases Medline and Embase to locate randomized controlled trials and observational studies. Risk of bias was investigated using the Cochrane Collaboration Tool for the Evaluation of Randomized Controlled Trials and the ROBINS-I quality assessment scale. Inclusion criteria were women of reproductive age, laparoscopically confirmed diagnosis of endometriosis, and intervention of any type of exercise. All manuscripts were evaluated by two of the authors and when in doubt a third author was consulted. This review was registered in PROSPERO on November 14, 2020 (CRD42020212309).
RESULTS
Six articles fulfilled the inclusion criteria and were included in this systematic review. Concerning exercise, two studies showed significant decrease in pain relief but the remaining studies showed either negative or no impact on pain relief. A meta-analysis could not be conducted because of the considerable heterogeneity among the included studies.
CONCLUSIONS
The present review does not indicate any beneficial effect of exercise on pain in women with endometriosis. There is a need for randomized controlled trials with correct power calculation, well-defined study groups and training programs to be able to answer the question of whether exercise can improve the pain experience in patients with endometriosis.
Topics: Endometriosis; Exercise Therapy; Female; Humans; Pain Perception; Pelvic Pain
PubMed: 33999412
DOI: 10.1111/aogs.14169 -
Lancet (London, England) Apr 2018Treatment-resistant major depressive disorder is common; repetitive transcranial magnetic stimulation (rTMS) by use of high-frequency (10 Hz) left-side dorsolateral... (Clinical Trial)
Clinical Trial Comparative Study Randomized Controlled Trial
BACKGROUND
Treatment-resistant major depressive disorder is common; repetitive transcranial magnetic stimulation (rTMS) by use of high-frequency (10 Hz) left-side dorsolateral prefrontal cortex stimulation is an evidence-based treatment for this disorder. Intermittent theta burst stimulation (iTBS) is a newer form of rTMS that can be delivered in 3 min, versus 37·5 min for a standard 10 Hz treatment session. We aimed to establish the clinical effectiveness, safety, and tolerability of iTBS compared with standard 10 Hz rTMS in adults with treatment-resistant depression.
METHODS
In this randomised, multicentre, non-inferiority clinical trial, we recruited patients who were referred to specialty neurostimulation centres based at three Canadian university hospitals (Centre for Addiction and Mental Health and Toronto Western Hospital, Toronto, ON, and University of British Columbia Hospital, Vancouver, BC). Participants were aged 18-65 years, were diagnosed with a current treatment-resistant major depressive episode or could not tolerate at least two antidepressants in the current episode, were receiving stable antidepressant medication doses for at least 4 weeks before baseline, and had an HRSD-17 score of at least 18. Participants were randomly allocated (1:1) to treatment groups (10 Hz rTMS or iTBS) by use of a random permuted block method, with stratification by site and number of adequate trials in which the antidepressants were unsuccessful. Treatment was delivered open-label but investigators and outcome assessors were masked to treatment groups. Participants were treated with 10 Hz rTMS or iTBS to the left dorsolateral prefrontal cortex, administered on 5 days a week for 4-6 weeks. The primary outcome measure was change in 17-item Hamilton Rating Scale for Depression (HRSD-17) score, with a non-inferiority margin of 2·25 points. For the primary outcome measure, we did a per-protocol analysis of all participants who were randomly allocated to groups and who attained the primary completion point of 4 weeks. This trial is registered with ClinicalTrials.gov, number NCT01887782.
FINDINGS
Between Sept 3, 2013, and Oct 3, 2016, we randomly allocated 205 participants to receive 10 Hz rTMS and 209 participants to receive iTBS. 192 (94%) participants in the 10 Hz rTMS group and 193 (92%) in the iTBS group were assessed for the primary outcome after 4-6 weeks of treatment. HRSD-17 scores improved from 23·5 (SD 4·4) to 13·4 (7·8) in the 10 Hz rTMS group and from 23·6 (4·3) to 13·4 (7·9) in the iTBS group (adjusted difference 0·103 [corrected], lower 95% CI -1·16; p=0·0011), which indicated non-inferiority of iTBS. Self-rated intensity of pain associated with treatment was greater in the iTBS group than in the 10 Hz rTMS group (mean score on verbal analogue scale 3·8 [SD 2·0] vs 3·4 [2·0] out of 10; p=0·011). Dropout rates did not differ between groups (10 Hz rTMS: 13 [6%] of 205 participants; iTBS: 16 [8%] of 209 participants); p=0·6004). The most common treatment-related adverse event was headache in both groups (10 Hz rTMS: 131 [64%] of 204; iTBS: 136 [65%] of 208).
INTERPRETATION
In patients with treatment-resistant depression, iTBS was non-inferior to 10 Hz rTMS for the treatment of depression. Both treatments had low numbers of dropouts and similar side-effects, safety, and tolerability profiles. By use of iTBS, the number of patients treated per day with current rTMS devices can be increased several times without compromising clinical effectiveness.
FUNDING
Canadian Institutes of Health Research.
Topics: Adult; Antidepressive Agents; Canada; Depression; Depressive Disorder, Major; Depressive Disorder, Treatment-Resistant; Female; Humans; Male; Middle Aged; Outcome Assessment, Health Care; Pain Perception; Prefrontal Cortex; Theta Rhythm; Transcranial Magnetic Stimulation; Treatment Outcome
PubMed: 29726344
DOI: 10.1016/S0140-6736(18)30295-2