Functional anatomy of hypnotic analgesia: A PET study of patients with fibromyalgia

Neuroscientific results of experimental studies on the control of acute pain with hypnosis and suggested analgesia

This narrative review summarizes a representative collection of electrophysiological and imaging studies on the neural processes and brain sources underlying hypnotic trance and the effects of hypnotic suggestions on the processing of experimentally induced painful events. It complements several reviews on the effect of hypnosis on brain processes and structures of chronic pain processing. Based on a summary of previous findings on the neuronal processing of experimentally applied pain stimuli and their effects on neuronal brain structures in healthy subjects, three neurophysiological methods are then presented that examine which of these neuronal processes and structures get demonstrably altered by hypnosis and can thus be interpreted as neuronal signatures of the effect of analgesic suggestions: (A) On a more global neuronal level, these are electrical processes of the brain that can be recorded from the cranial surface of the brain with magnetoencephalography (MEG) and electroencephalography (EEG). (B) On a second level, so-called evoked (EPs) or event-related potentials (ERPs) are discussed, which represent a subset of the brain electrical parameters of the EEG. (C) Thirdly, imaging procedures are summarized that focus on brain structures involved in the processing of pain states and belong to the main imaging procedures of magnetic resonance imaging (MRI/fMRI) and positron emission tomography (PET). Finally, these different approaches are summarized in a discussion, and some research and methodological suggestions are made as to how this research could be improved in the future.

Neural functional correlates of hypnosis and hypnoanalgesia: Role of the cingulate cortex

Hypnosis is a hetero-induced or self-induced altered state of consciousness that involves focused attention and reduced peripheral awareness. It is determined by response to suggestions and can be used in the management of various clinical conditions. Nowadays there is growing attention to the neurobiological correlates of hypnosis because of its future clinical applications. The greater attention is due to the wide range of applications that might stem from its knowledge. Functional neuroimaging studies show that hypnosis affects attention by modulating the activation of the anterior cingulate cortex and other brain areas, modifying the conflict monitoring and cognitive control. During hypnoanalgesia, several changes in brain functions occur in all the areas of the pain network, and other brain areas. Among these, the anterior cingulate cortex is significantly involved in modulating the activity of pain circuits under hypnosis, both in the affective, sensory-cognitive, and behavioral aspects. The study of the functionality of the cingulate cortices, mainly the anterior and medial portions, appears to be crucial for better understanding the hypnotic phenomena, related to both the neurocognitive and somatosensory aspects.

Neurophysiology of hypnosis in chronic pain: A review of recent literature

Chronic pain is a complex phenomenon which includes biological, psychological, and socio-professional factors that undermine patients' everyday life. Currently, only few patients significantly benefit from pharmacological treatments and many have to stop them because of negative side effects. Moreover, no medication or treatment addresses all aspects of chronic pain at once (i.e., sensations, emotions, behaviors, and cognitions), positioning chronic pain as an important public health issue and thus contributing to high health-care costs. Consequently, patients and health-care providers are increasingly turning to complementary non-pharmacological techniques such as hypnosis. Clinical research has demonstrated a decrease of pain perception, pain interference, depression and anxiety, and an increase in global quality of life when patients with chronic pain have benefited from hypnosis learning. Neuroimaging studies offer a possible explanation of these results by focusing on neural processes of pain modulation in chronic pain patients' brain. Studies conducted with chronic pain patients showed a modulation of pain matrix activity during hypnosis with a specific involvement of the anterior cingulate cortex (related to emotional and cognitive processing of pain). Therefore, hypnosis seems to act upon regions underlying emotion and cognition, with an influence on pain perception and emotional regulation. In this review, we propose to carry out a review of the recent literature on hypnosis in chronic pain management. A better understanding of the beneficial effects of hypnosis on chronic pain and its neurophysiology should enable more systematic use of this technique in the management of this complex health problem.

The Link between Fibromyalgia Syndrome and Anger: A Systematic Review Revealing Research Gaps

Anger has been associated with increased pain perception, but its specific connection with Fibromyalgia Syndrome (FMS) has not yet been established in an integrated approach. Therefore, the present systematic review focuses on exploring this connection, and based on this connection, delimiting possible gaps in the research, altogether aimed at improving FMS clinical intervention and guiding future research lines. Anger is considered a basic negative emotion that can be divided into two dimensions: anger-in (the tendency to repress anger when it is experienced) and anger-out (the leaning to express anger through verbal or physical means). The current systematic review was performed based on the guidelines of the PRISMA and Cochrane Collaborations. The Prospective Register of Systematic Reviews (PROSPERO) international database was forehand used to register the review protocol. The quality of chosen articles was assessed and the main limitations and research gaps resulting from each scientific article were discussed. The search included PubMed, Scopus, and Web of Science databases. The literature search identified 13 studies eligible for the systematic review. Levels of anger-in have been shown to be higher in FMS patients compared to healthy participants, as well as patients suffering from other pain conditions (e.g., rheumatoid arthritis). FMS patients had also showed higher levels of state and trait anxiety, worry and angry rumination than other chronic pain patients. Anger seems to amplify pain especially in women regardless FMS condition but with a particularly greater health-related quality of life´s impact in FMS patients. In spite of the relevance of emotions in the treatment of chronic pain, including FMS, only two studies have proposed intervention programs focus on anger treatment. These two studies have observed a positive reduction in anger levels through mindfulness and a strength training program. In conclusion, anger might be a meaningful therapeutic target in the attenuation of pain sensitivity, and the improvement of the general treatment effects and health-related quality of life in FMS patients. More intervention programs directed to reduce anger and contribute to improve well-being in FMS patients are needed.

The Hypnotic Analgesia Suggestion Mitigated the Effect of the Transcranial Direct Current Stimulation on the Descending Pain Modulatory System: A Proof of Concept Study

Objective

We evaluated whether active(a)-tDCS combined with hypnotic analgesia suggestion (HS) would be more effective than a single active(a)-tDCS, and/or sham-(s)-tDCS and s-tDCS/HS on the following outcomes: function of descending pain modulatory system (DPMS) during the conditioned pain modulation test (CPM-test) (primary outcome), heat pain threshold (HPT), heat pain tolerance (HPTo) and cold pressor test (CPT) (secondary outcomes). We also examined whether their effects are related to neuroplasticity state evaluated by serum brain-derived-neurotropic factor (BDNF).

Materials and Methods

Forty-eight females received one session of one of the four interventions (a-tDCS/HS, s-tDCS/HS, a-tDCS, and s-tDCS) in an incomplete randomized crossover sequence. The a-tDCS or s-tDCS was applied over the left dorsolateral prefrontal cortex (DLPFC) for 30 minutes at 2mA.

Results

A generalized linear model revealed a significant main effect for the intervention group (P <0.032). The delta-(Δ) pain score on the Numerical Pain Scale (NPS0-10) during CPM-test in the a-tDCS/HS group was -0.25 (0.43). The (Δ) pain score on NPS (0-10) during CPM-test in the other three groups was a-tDCS=-0.54 (0.41), HS -0.01 (0.41) and s-tDCS/HS=-0.19 (0.43). A-tDCS/HS intervention increased the CPT substantially compared to all other interventions. Also, higher baseline levels of BDNF were associated with a larger change in CPT and HPTo.

Conclusion

These findings indicate that the HS combined with a-tDCS mitigated the effect of the a-tDCS on the DPMS. The a-tDCS up-regulates the inhibition on DPMS, and the HS improved pain tolerance. And, together they enhanced the reaction time substantially upon the CPT.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier NCT03744897.

Effects of a Hypnotic Induction and an Unpleasantness-Focused Analgesia Suggestion on Pain Catastrophizing to an Experimental Heat Stimulus: A Preliminary Study

Pain catastrophizing is associated with greater levels of pain. While many studies support the efficacy of hypnosis for pain, the effect on pain catastrophizing remains unclear. The present study evaluated the effect of hypnosis on pain catastrophizing using experimental heat stimulation. Twenty-two pain patients engaged in 3 conditions: baseline (no suggestion), hypnotic induction, and hypnotic induction plus analgesia suggestion. Participants with higher baseline pain showed a significant reduction in rumination following hypnotic induction plus analgesia suggestion and significant reductions in pain due to both the hypnotic induction alone and the hypnotic induction plus analgesia suggestion. The findings suggest that unpleasantness-focused hypnotic analgesia reduces pain via its effect on the rumination component of pain catastrophizing.

Fibromyalgia, Fibro Fog, and Exercise

Fibro fog causes serious problems for those with fibromyalgia syndrome. The mechanisms that cause it have not been well identified. Since prescription medication and other conventional medical interventions have proven less than satisfactory, and while waiting for more investigational information, research suggests that exercise might be helpful.

Chaos-chaos transition of left hemisphere EEGs during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility

A recent study, recurrence quantification analysis of EEG signals during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility investigated recurrence quantifiers (RQs) of hypnotic electroencephalograph (EEG) signals recorded after hypnotic induction while subjects were doing standard tasks of Waterloo-Stanford Group Scale (WSGS) of hypnotic susceptibility to distinguish subjects of different hypnotizability levels. Following the same analysis, the current study determines the capability of different RQs to distinguish subjects of low, medium and high hypnotizability level and studies the influence of hypnotizability level on underlying dynamic of tasks. Besides, EEG channels were sorted according to the number of their RQs, which differed significantly among subjects of different hypnotizability levels. Another valuable result was determination of major brain regions in observing significant differences in various task types (ideomotors, hallucination, challenge and memory).

Pain perception and hypnosis: findings from recent functional neuroimaging studies

Hypnosis modulates pain perception and tolerance by affecting cortical and subcortical activity in brain regions involved in these processes. By reviewing functional neuroimaging studies focusing on pain perception under hypnosis, the authors aimed to identify brain activation-deactivation patterns occurring in hypnosis-modulated pain conditions. Different changes in brain functionality occurred throughout all components of the pain network and other brain areas. The anterior cingulate cortex appears to be central in modulating pain circuitry activity under hypnosis. Most studies also showed that the neural functions of the prefrontal, insular, and somatosensory cortices are consistently modified during hypnosis-modulated pain conditions. Functional neuroimaging studies support the clinical use of hypnosis in the management of pain conditions.

Hypnosis and imaging of the living human brain

Over more than two decades, studies using imaging techniques of the living human brain have begun to explore the neural correlates of hypnosis. The collective findings provide a gripping, albeit preliminary, account of the underlying neurobiological mechanisms involved in hypnotic phenomena. While substantial advances lend support to different hypotheses pertaining to hypnotic modulation of attention, control, and monitoring processes, the complex interactions among the many mediating variables largely hinder our ability to isolate robust commonalities across studies. The present account presents a critical integrative synthesis of neuroimaging studies targeting hypnosis as a function of suggestion. Specifically, hypnotic induction without task-specific suggestion is examined, as well as suggestions concerning sensation and perception, memory, and ideomotor response. The importance of carefully designed experiments is highlighted to better tease apart the neural correlates that subserve hypnotic phenomena. Moreover, converging findings intimate that hypnotic suggestions seem to induce specific neural patterns. These observations propose that suggestions may have the ability to target focal brain networks. Drawing on evidence spanning several technological modalities, neuroimaging studies of hypnosis pave the road to a more scientific understanding of a dramatic, yet largely evasive, domain of human behavior.

Neurophysiological correlates of dissociative symptoms

OBJECTIVE

Dissociation is a mental process with psychological and somatoform manifestations, which is closely related to hypnotic suggestibility and essentially shows the ability to obtain distance from reality. An increased tendency to dissociate is a frequently reported characteristic of patients with functional neurological symptoms and syndromes (FNSS), which account for a substantial part of all neurological admissions. This review aims to investigate what heart rate variability (HRV), EEG and neuroimaging data (MRI) reveal about the nature of dissociation and related conditions.

METHODS

Studies reporting HRV, EEG and neuroimaging data related to hypnosis, dissociation and FNSS were identified by searching the electronic databases Pubmed and ScienceDirect.

RESULTS

The majority of the identified studies concerned the physiological characteristics of hypnosis; relatively few investigations on dissociation related FNSS were identified. General findings were increased parasympathetic functioning during hypnosis (as measured by HRV), and lower HRV in patients with FNSS. The large variety of EEG and functional MRI investigations with diverse results challenges definite conclusions, but evidence suggests that subcortical as well as (pre)frontal regions serve emotion regulation in dissociative conditions. Functional connectivity analyses suggest the presence of altered brain networks in patients with FNSS, in which limbic areas have an increased influence on motor preparatory regions.

CONCLUSIONS

HRV, EEG and (functional) MRI are sensitive methods to detect physiological changes related to dissociation and dissociative disorders such as FNSS, and can possibly provide more information about their aetiology. The use of such measures could eventually provide biomarkers for earlier identification of patients at risk and appropriate treatment of dissociative conditions.

An hypnotic suggestion: review of hypnosis for clinical emergency care

BACKGROUND

Hypnosis has been used in medicine for nearly 250 years. Yet, emergency clinicians rarely use it in emergency departments or prehospital settings.

OBJECTIVE

This review describes hypnosis, its historical use in medicine, several neurophysiologic studies of the procedure, its uses and potential uses in emergency care, and a simple technique for inducing hypnosis. It also discusses reasons why the technique has not been widely adopted, and suggests methods of increasing its use in emergency care, including some potential research areas.

DISCUSSION

A limited number of clinical studies and case reports suggest that hypnosis may be effective in a wide variety of conditions applicable to emergency medical care. These include providing analgesia for existing pain (e.g., fractures, burns, and lacerations), providing analgesia and sedation for painful procedures (e.g., needle sticks, laceration repair, and fracture and joint reductions), reducing acute anxiety, increasing children's cooperation for procedures, facilitating the diagnosis and treatment of acute psychiatric conditions, and providing analgesia and anxiolysis for obstetric/gynecologic problems.

CONCLUSIONS

Although it is safe, fast, and cost-effective, emergency clinicians rarely use hypnosis. This is due, in part, to the myths surrounding hypnosis and its association with alternative-complementary medicine. Genuine barriers to its increased clinical use include a lack of assured effectiveness and a lack of training and training requirements. Based on the results of further research, hypnosis could become a powerful and safe nonpharmacologic addition to the emergency clinician's armamentarium, with the potential to enhance patient care in emergency medicine, prehospital care, and remote medical settings.

Neurophysiology of hypnosis

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.

Neurophysiology of pain and hypnosis for chronic pain

In the past decade there has been a dramatic increase in (1) understanding the neurophysiological components of the pain experiences, (2) randomized clinical trials testing the efficacy of hypnotic treatments on chronic pain, and (3) laboratory research examining the effects of hypnosis on the neurophysiological processes implicated in pain. Work done in these areas has not only demonstrated the efficacy of hypnosis for treating chronic pain but is beginning to shed light on neurophysiological processes that may play a role in its effectiveness. This paper reviews a selection of published studies from these areas of research, focusing on recent findings that have the most potential to inform both clinical work and research in this area. The paper concludes with research and clinical recommendations for maximizing treatment efficacy based on the research findings that are available.

The impacts of hypnotic susceptibility on chaotic dynamics of EEG signals during standard tasks of Waterloo-Stanford Group Scale

Chaotic features of hypnotic EEG (electroencephalograph), recorded during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility (WSGS), were used to investigate the underlying dynamic of tasks and analyse the effect of hypnotic depth and concentration on EEG signals. Results demonstrate: (1) More efficiency of Higuchi dimension in comparison with Correlation dimension to distinguish subjects from different hypnotizable groups, (2) Channels with significantly different chaotic features among people from various hypnotizability levels in tasks, (3) High level of consistency among discriminating channels of tasks with function of brain's lobes, (4) Most affectability of medium hypnotizable subjects and (5) Rise in fractal dimensions due to increase in hypnosis depth.

Do patients with fibromyalgia show abnormal neural responses to the observation of pain in others?

Chronic widespread pain is a hallmark of fibromyalgia (FM). Previous neuroimaging studies have reported that the pain neuro-matrix in patients with FM showed augmented activation in response to actual pain. However, the effect of observing pain in others among patients with FM remains poorly understood. Both healthy female control subjects (n=24) and female patients with FM (n=23) underwent functional magnetic resonance imaging while observing a series of color pictures depicting others' hands and feet being injured, and a matched set of control pictures that did not show any painful events. Compared with healthy subjects, patients with FM showed a smaller neural response to pain-related versus neutral stimuli in several neural regions, including the thalamus, anterior cingulate cortex, dorsolateral prefrontal cortex, pre- and post-central gyrus, and supplementary motor area. In contrast to augmented pain processing in response to actual experimental pain, patients with FM did not show an enhanced pain response but generally showed lesser activation in cortical regions known to play a role in processing of pain. These hemodynamic alterations observed in patients with FM suggest that patients with chronic pain may empathize less with others in pain, possibly in order to lessen arousal and aversive self-oriented emotions.

Theories of pain: from specificity to gate control

Several theoretical frameworks have been proposed to explain the physiological basis of pain, although none yet completely accounts for all aspects of pain perception. Here, we provide a historical overview of the major contributions, ideas, and competing theories of pain from ancient civilizations to Melzack and Wall's Gate Control Theory of Pain.

The use of functional neuroimaging to evaluate psychological and other non-pharmacological treatments for clinical pain

A large number of studies have provided evidence for the efficacy of psychological and other non-pharmacological interventions in the treatment of chronic pain. While these methods are increasingly used to treat pain, remarkably few studies focused on the exploration of their neural correlates. The aim of this article was to review the findings from neuroimaging studies that evaluated the neural response to distraction-based techniques, cognitive behavioral therapy (CBT), clinical hypnosis, mental imagery, physical therapy/exercise, biofeedback, and mirror therapy. To date, the results from studies that used neuroimaging to evaluate these methods have not been conclusive and the experimental methods have been suboptimal for assessing clinical pain. Still, several different psychological and non-pharmacological treatment modalities were associated with increased pain-related activations of executive cognitive brain regions, such as the ventral- and dorsolateral prefrontal cortex. There was also evidence for decreased pain-related activations in afferent pain regions and limbic structures. If future studies will address the technical and methodological challenges of today's experiments, neuroimaging might have the potential of segregating the neural mechanisms of different treatment interventions and elucidate predictive and mediating factors for successful treatment outcomes. Evaluations of treatment-related brain changes (functional and structural) might also allow for sub-grouping of patients and help to develop individualized treatments.

Use of hypnosis in the treatment of pain

Hypnosis is an altered state of consciousness that comprises of heightened absorption in focal attention, dissociation of peripheral awareness, and enhanced responsiveness to social cues. Hypnosis has a long tradition of effectiveness in controlling somatic symptoms, such as pain. Pain, the most common symptom in clinical practice, is a multi-dimensional experience, which includes sensory-discriminative, affective-emotional, cognitive and behavioral components. There is a growing recognition for hypnosis and related techniques in pain management. Psychological approaches to pain control, such as hypnosis, can be highly effective analgesics, but are underused in Korea. In this article, we would like to review the basic concepts of hypnosis, the mechanism, and the outcome data of the analgesic effects of hypnosis, and also, its limitations.

Multicomponent cognitive-behavioral group therapy with hypnosis for the treatment of fibromyalgia: long-term outcome

This study compared the efficacy of 2 psychological treatments for fibromyalgia with each other and with standard care. Ninety-three patients with fibromyalgia (FM) were randomly assigned to 1 of the 3 experimental conditions: 1) multicomponent cognitive-behavioral therapy (CBT); 2) multicomponent CBT with hypnosis; and 3) pharmacological treatment (standard care control group). The outcome measures of pain intensity, catastrophizing, psychological distress, functionality, and sleep disturbances were assessed before treatment, immediately after treatment, and at 3- and 6-month follow-up visits. CBT and CBT with hypnosis participants received the standard pharmacological management plus 14 weekly, 120-minute-long sessions of psychological treatment. All but 1 session followed a group format; the remaining session was individual. The analyses indicated that: 1) patients with FM who received multicomponent CBT alone or multicomponent CBT with hypnosis showed greater improvements than patients who received only standard care; and 2) adding hypnosis enhanced the effectiveness of multicomponent CBT. This study presents new evidence about the efficacy of multicomponent CBT for FM and about the additional effects of hypnosis as a complement to CBT. The relevance and implications of the obtained results are discussed.

PERSPECTIVE

This article highlights the beneficial effects of adding hypnosis in a multicomponent cognitive-behavioral group treatment of fibromyalgia patients. Also, this research showed that by adding hypnosis the length of treatment did not increase.

Effect of hypnotic suggestion on fibromyalgic pain: Comparison between hypnosis and relaxation

The main aims of this experimental study are: (1) to compare the relative effects of analgesia suggestions and relaxation suggestions on clinical pain, and (2) to compare the relative effect of relaxation suggestions when they are presented as "hypnosis" and as "relaxation training". Forty-five patients with fibromyalgia were randomly assigned to one of the following experimental conditions: (a) hypnosis with relaxation suggestions; (b) hypnosis with analgesia suggestions; (c) relaxation. Before and after the experimental session, the pain intensity was measured using a visual analogue scale (VAS) and the sensory and affective dimensions were measured with the McGill Pain Questionnaire. The results showed: (1) that hypnosis followed by analgesia suggestions has a greater effect on the intensity of pain and on the sensory dimension of pain than hypnosis followed by relaxation suggestions; (2) that the effect of hypnosis followed by relaxation suggestions is not greater than relaxation. We discuss the implications of the study on our understanding of the importance of suggestions used in hypnosis and of the differences and similarities between hypnotic relaxation and relaxation training.

Review of neuroimaging studies related to pain modulation

Background and purpose: A noxious stimulus does not necessarily cause pain. Nociceptive signals arising from a noxious stimulus are subject to modulation via endogenous inhibitory and facilitatory mechanisms as they travel from the periphery to the dorsal horn or brainstem and on to higher brain sites. Research on the neural structures underlying endogenous pain modulation has largely been restricted to animal research due to the invasiveness of such studies (e.g., spinal cord transection, brain lesioning, brain site stimulation). Neuroimaging techniques (e.g., magnetoencephalography (MEG), positron emission tomography (PET) and functional magnetic resonance imaging (fMRI)) provide non-invasive means to study neural structures in humans. The aim is to provide a narrative review of neuroimaging studies related to human pain control mechanisms.

Methods: The approach taken is to summarise specific pain modulation mechanisms within the somatosensory (diffuse noxious inhibitory controls, acupuncture, movement), affective (depression, anxiety, catastrophizing, stress) and cognitive (anticipation/placebo, attention/distraction, hypnosis)domains with emphasis on the contribution of neuroimaging studies.

Results and conclusions: Findings from imaging studies are complex reflecting activation or deactivation in numerous brain areas. Despite this, neuroimaging techniques have clarified supraspinal sites involved in a number of pain control mechanisms. The periaqueductal grey (PAG) is one area that has consistently been shown to be activated across the majority of pain mechanisms. Activity in the rostral ventromedial medulla known to relay descending modulation from the PAG, has also been observed both during acupuncture analgesia and anxiety-induced hyperalgesia. Other brain areas that appear to be involved in a number of mechanisms are the anterior cingulate cortex, prefrontal cortex, orbitofrontal cortex and nucleus accumbens, but their exact role is less clear.

Implications: Neuroimaging studies have provided essential information about the pain modulatory pathways under normal conditions, but much is still to be determined. Understanding the mechanisms of pain control is important for understanding the mechanisms that contribute to failed pain control in chronic pain. Applying fMRI outside the brain, such as in the trigeminal nucleus caudalis of the spinotrigeminal pathway and in the dorsal horn of the spinal cord, and coupling brain activity with activity at these sites may help improve our understanding of the function of brain sites and shed light on functional connectivity in the pain pathway.

© 2011 Scandinavian Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Hypnosis for functional abdominal pain

Chronic abdominal pain is a common pediatric condition affecting 20% of the pediatric population worldwide. Most children with this disorder are found to have no specific organic etiology and are given the diagnosis of functional abdominal pain. Well-designed clinical trials have found hypnotherapy and guided imagery to be the most efficacious treatments for this condition. Hypnotic techniques used for other somatic symptoms are easily adaptable for use with functional abdominal pain. The author discusses 2 contrasting hypnotic approaches to functional abdominal pain and provides implications for further research. These approaches may provide new insights into this common and complex disorder.

Can neuroimaging help us to understand and classify somatoform disorders? A systematic and critical review

OBJECTIVE

Debate about the nature of somatoform disorders and their current diagnostic classification has been stimulated by the anticipation of new editions of Diagnostic and Statistical Manual of Mental Disorders and International Statistical Classification of Diseases and Related Health Problems diagnostic classifications. In the current paper, we review systematically the literature on the neuroimaging of somatoform disorders and related conditions with the aim of addressing two specific questions: Is there evidence of altered neural function or structure that is specifically associated with somatoform disorders? What conclusions can we draw from these findings about the etiology of somatoform disorders?

METHODS

Studies reporting neuroimaging findings in patients with a somatoform disorder or a functional somatic syndrome (such as fibromyalgia) were found using Pubmed, PsycINFO, and EMBASE database searches. Reported structural and functional neuroimaging findings were then extracted to form a narrative review.

RESULTS

A relatively mature literature on symptoms of pain and less developed literatures on conversion and fatigue symptoms were identified. The available evidence indicates that, when compared with nonclinical groups, somatoform diagnoses are associated with increased activity of limbic regions in response to painful stimuli and a generalized decrease in gray matter density; however, methodological considerations restrict the interpretation of these findings.

CONCLUSIONS

Whereas the neuroimaging literature has provided evidence about the possible mechanisms underlying somatoform disorders, this is not yet sufficient to provide a basis for classification. By adopting a wider variety of experimental designs and a more dynamic approach to diagnosis, there is every reason to be hopeful that neuroimaging data will play a significant role in future taxonomies.

Differential central pain processing following repetitive intramuscular proton/prostaglandin E₂ injections in female fibromyalgia patients and healthy controls

BACKGROUND

While the etiology of fibromyalgia syndrome (FMS) remains unclear, it is assumed that both peripheral and central components are involved.

AIMS/METHODS

To investigate central activation patterns following chemically-induced muscle pain we repetitively injected protons (low pH) and prostaglandin E(2) (PGE(2)) in isotonic solution into the left extensor carpi radialis brevis muscle of female FMS patients and female healthy control subjects (HC). The injection of protons/PGE(2) has the advantage that it is not prone to tachyphylaxis compared to capsaicin and hypotonic saline solution. During the repetitive injections continuous pain ratings were recorded and functional magnetic resonance imaging measurements were conducted.

RESULTS

Injection of protons/PGE(2) led to activation of the anterior and medial cingulate cortices, contralateral primary sensory cortex, bilateral insula and thalamus, left basal ganglia, left orbitofrontal cortex and the cerebellum in FMS patients. In HC, activations were found only in the anterior, medial, and posterior cingulate cortices, and the primary somatosensory cortex. The contrast between the groups revealed significantly stronger activation for FMS patients in the left anterior insula. Peak pain ratings were comparable between HC and FMS patients, but pain duration (sustained pain) was prolonged in FM.

CONCLUSION

Repetitive proton/PGE(2)-induced excitation of muscle tissue led to a more prolonged perception of pain and more wide-spread activation in pain-related brain areas in FMS, especially in the left (ipsilateral) insula, whereas acute protons/PGE(2)-induced pain processing was similar in the two groups. These data provide further evidence for enhanced central pain processing in FMS patients.

Chronic low-back pain modulation is enhanced by hypnotic analgesic suggestion by recruiting an emotional network: a PET imaging study

This study aimed to characterize the neural networks involved in patients with chronic low-back pain during hypnoanalgesia. PET was performed in 2 states of consciousness, normal alertness and hypnosis. Two groups of patients received direct or indirect analgesic suggestion. The normal alertness state showed activations in a cognitive-sensory pain modulation network, including frontotemporal cortex, insula, somatosensory cortex, and cerebellum. The hypnotic state activated an emotional pain modulation network, including frontotemporal cortex, insula, caudate, accumbens, lenticular nuclei, and anterior cingulate cortex (ACC). Direct suggestion activated cognitive processes via frontal, prefrontal, and orbitofrontal cortices, while indirect suggestion activated a widespread and more emotional network including frontal cortex, anterior insula, inferior parietal lobule, lenticular nucleus, and ACC. Confirmed by visual analog scale data, these results suggest that chronic pain modulation is greater with hypnosis, which enhances both activated networks.

A new mind-body approach for a total healing of fibromyalgia: a case report

Fibromyalgia is a severe, chronic and widespread pain syndrome with no definite treatment protocol. Several medications are currently in use to treat this condition. Various pharmacological treatments, as well as alternative mind-body therapies, have been directed towards reducing fatigue and pain, but these treatments have only resulted in a partial relief of symptoms with no long-term or permanent effects. This study shows the results obtained from four female patients suffering from fibromyalgia after undergoing a mind-body treatment in which psychosocial genomic postulates as well as ideodynamic hand movements were the main tools employed in their healing. It is suggested that a mind-body oriented treatment could generate stable and permanent changes that enable patients to experience a total recovery from fibromyalgia.

The neurophysiology of pain perception and hypnotic analgesia: implications for clinical practice

Although there remains much to be learned, a great deal is now known about the neurophysiological processes involved in the experience of pain. Research confirms that there is no single focal "center" in the brain responsible for the experience of pain. Rather, pain is the end product of a number of integrated networks that involve activity at multiple cortical and subcortical sites. Our current knowledge about the neurophysiological mechanisms of pain has important implications for understanding the mechanisms underlying the effects of hypnotic analgesia treatments, as well as for improving clinical practice. This article is written for the clinician who uses hypnotic interventions for pain management. It begins with an overview of what is known about the neurophysiological basis of pain and hypnotic analgesia, and then discusses how clinicians can use this knowledge for (1) organizing the types of suggestions that can be used when providing hypnotic treatment, and (2) maximizing the efficacy of hypnotic interventions in clients presenting with pain problems.

[Etiology and pathophysiology of fibromyalgia syndrome and chronic widespread pain]

OBJECTIVE

To write a systematic review on the etiology and pathophysiology of the fibromyalgia syndrome (FMS) and of chronic widespread pain (CWP).

METHODS

An interdisciplinary level-3 guideline (i.e. systematic literature search and assessment, logic analysis, formal consensus procedure) for the diagnosis and therapy of FMS was created in cooperation with 10 medical and psychological societies and 2 patient self-help organizations. A literature search was performed covering all available review articles on the etiology and pathophysiology of FMS and CWP using the Cochrane Collaboration Reviews (1993-12/2006), Medline (1980-2006), PsychInfo (1966-12/2006), and Scopus (1980-12/2006). For the assignment of evidence classes the system of the Oxford Centre for Evidence-Based Medicine was applied. Consensus was achieved by a multi-step nominal group procedure.

RESULTS

FMS aggregates in families (evidence level 2c). Physical and psychological stress at the workplace are risk factors for the development of CWP and FMS. Affective disorders are risk factors for the development and maintenance of FMS. Operant learning mechanisms and sensitization are risk factors for the chronification of FMS (evidence levels 2b). Several factors are associated with the pathophysiology of FMS, but the causal relationship is unclear. This includes alterations of central pain pathways, hyporeactivity of the hypothalamus-pituitary-adrenal axis, increased systemic pro-inflammatory and reduced anti-inflammatory cytokine profiles and disturbances in the dopaminergic and serotonergic systems.

CONCLUSIONS

FMS is the common final product of various etiological factors and pathophysiological mechanisms.

Hypnosis as a treatment of chronic widespread pain in general practice: a randomized controlled pilot trial

BACKGROUND

Hypnosis treatment in general practice is a rather new concept. This pilot study was performed to evaluate the effect of a standardized hypnosis treatment used in general practice for patients with chronic widespread pain (CWP).

METHODS

The study was designed as a randomized control group-controlled study. Sixteen patients were randomized into a treatment group or a control group, each constituting eight patients. Seven patients in the treatment group completed the schedule. After the control period, five of the patients in the control group also received treatment, making a total of 12 patients having completed the treatment sessions. The intervention group went through a standardized hypnosis treatment with ten consecutive therapeutic sessions once a week, each lasting for about 30 minutes, focusing on ego-strengthening, relaxation, releasing muscular tension and increasing self-efficacy. A questionnaire was developed in order to calibrate the symptoms before and after the 10 weeks period, and the results were interpolated into a scale from 0 to 100, increasing numbers representing increasing suffering. Data were analyzed by means of T-tests.

RESULTS

The treatment group improved from their symptoms, (change from 62.5 to 55.4), while the control group deteriorated, (change from 37.2 to 45.1), (p = 0,045). The 12 patients who completed the treatment showed a mean improvement from 51.5 to 41.6. (p = 0,046). One year later the corresponding result was 41.3, indicating a persisting improvement.

CONCLUSION

The study indicates that hypnosis treatment may have a positive effect on pain and quality of life for patients with chronic muscular pain. Considering the limited number of patients, more studies should be conducted to confirm the results.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov and released 27.08.07 Reg nr NCT00521807 Approval Number: 05032001.

Insular hypometabolism in a patient with fibromyalgia: a case study

BACKGROUND

Neuroimaging studies have demonstrated differential involvement of a variety of brain centers in fibromyalgia both at baseline and in response to stimulation. The insular cortex is one such structure.

FINDINGS

A 46-year-old woman with chronic widespread pain underwent positron emission tomography utilizing 18F-fluorodeoxyglucose while participating as a healthy control subject in a brain imaging study. Analysis of the scan revealed metabolic hypoactivity within the left insular cortex as an incidental finding. Soon after her scan, she underwent further clinical evaluation and was subsequently diagnosed with fibromyalgia.

DISCUSSION

The potential contribution of insular dysfunction to the development of hyperalgesia has been demonstrated in rat models via local manipulations of dopaminergic, gamma-aminobutyric acid (GABA) ergic, and opioidergic neurotransmission within this region. Thus, our demonstration of insular hypometabolism in this patient's case may have bearing on her experience of chronic widespread pain.

Hypnotic treatment synergizes the psychological treatment of fibromyalgia: a pilot study

In this pilot study, we compare the efficacy for fibromyalgia of multimodal cognitive behavioral treatments, with and without hypnosis, with that of a purely pharmacological approach, with a multiple baseline N = 1 design. We randomly assigned six hospital patients to the three experimental conditions. The results suggest that psychological treatment produces greater symptom benefits than the conventional medical treatment only, especially when hypnosis is added. We conclude that hypnosis may be a useful tool to help people with fibromyalgia manage their symptomatology.

Fractal analysis of EEG in hypnosis and its relationship with hypnotizability

Fractal analysis was applied to study the trends of EEG signals in the hypnotic condition. The subjects were 19 psychiatric outpatients. Hypnotizability was measured with the Hypnotic Induction Profile (HIP). Fifty-four sets of EEG data were analyzed by detrended fluctuation analysis (DFA), a well-established fractal analysis technique. The scaling exponents, which are the results of fractal analysis, are reduced toward white noise during the hypnotic condition, which differentiates the hypnotic condition from the waking condition. Further, the decrease in the scaling exponents during hypnosis was solely associated with the eye-roll sign within specific cortical areas (F3, C4, and O1/2) closely related to eye movements and attention. In conclusion, the present study has found that the application of the fractal analysis technique can demonstrate the electrophysiological correlations with hypnotic influence on cerebral activity.

Cognitive dysfunction in fibromyalgia and chronic fatigue syndrome: New trends and future directions

Fibromyalgia (FM) and chronic fatigue syndrome (CFS) patients often have memory and cognitive complaints. Objective cognitive testing demonstrates long-term and working memory impairments. In addition, CFS patients have slow information-processing, and FM patients have impaired control of attention, perhaps due to chronic pain. Neuroimaging studies demonstrate cerebral abnormalities and a pattern of increased neural recruitment during cognitive tasks. Future work should focus on the specific neurocognitive systems involved in cognitive dysfunction in each syndrome.

The use of hypnosis to improve pain management during voluntary interruption of pregnancy: an open randomized preliminary study

OBJECTIVE

This report describes an open randomized study that aims to determine whether a brief hypnotic intervention during first-trimester surgical abortion reduces requests for pain medication.

METHODS

Thirty women undergoing first-trimester surgical abortion at the family planning clinics of a large hospital in Quebec City were randomized into a control group that received standard care and a hypnosis group that received, in addition to standard care, an intervention of hypnosis, including analgesia suggestions 20 min before and throughout the surgical procedure. Patients in both groups were given the option to control their pain with nitrous oxide (N(2)O) sedation administered through a nose mask as often and for as long as they wanted during the procedure. N(2)O sedation as the primary outcome was assessed at each step of the procedure. The patient's self-reported anxiety and pain were also assessed during the procedure as secondary outcomes.

RESULTS

Thirty-six percent of patients in the hypnosis group requested N(2)O sedation during the procedure versus 87% in the control group (p<.01). No differences between the groups were found in reports of pain and anxiety during the procedure.

CONCLUSION

These results suggest that hypnosis can be integrated into standard care and reduces the need for N(2)O in patients undergoing first-trimester surgical abortion. This reduction in N(2)O consumption did not lead to significant changes in pain or anxiety, and a larger sample size is required to assess the possible effects of hypnosis on those variables.

Retrospenial cortical deactivation during painful stimulation of fibromyalgic patients

To study fibromyalgic pain this article contrasts positron emission tomographic measures of regional cerebral blood flow (rCBF) during externally induced acute pain and rest in eight fibromyalgia syndrome patients. An expected pattern of frontal and parietal cortical activation during acute pain as compared to rest was observed. However, reduced rCBF was additionally found in the retrosplenial cortex during acute pain as compared to rest. This may reflect that externally induced pain inhibits fibromyalgic pain and syndrome-related evaluative processes located in the retrosplenial cortex, and that fibromyalgic pain results from exaggerated attention to sub-noxious pain signaling, that is, secondary hyperalgesia.

Hypnosis decouples cognitive control from conflict monitoring processes of the frontal lobe

Hypnosis can profoundly alter sensory awareness and cognitive processing. While the cognitive and behavioral phenomena associated with hypnosis have long been thought to relate to attentional processes, the neural mechanisms underlying susceptibility to hypnotic induction and the hypnotic condition are poorly understood. Here, we tested the proposal that highly hypnotizable individuals are particularly adept at focusing attention at baseline, but that their attentional control is compromised following hypnosis due to a decoupling between conflict monitoring and cognitive control processes of the frontal lobe. Employing event-related fMRI and EEG coherence measures, we compared conflict-related neural activity in the anterior cingulate cortex (ACC) and control-related activity in the lateral frontal cortex (LFC) during Stroop task performance between participants of low and high hypnotic susceptibility, at baseline and after hypnotic induction. The fMRI data revealed that conflict-related ACC activity interacted with hypnosis and hypnotic susceptibility, in that highly susceptible participants displayed increased conflict-related neural activity in the hypnosis condition compared to baseline, as well as with respect to subjects with low susceptibility. Cognitive-control-related LFC activity, on the other hand, did not differ between groups and conditions. These data were complemented by a decrease in functional connectivity (EEG gamma band coherence) between frontal midline and left lateral scalp sites in highly susceptible subjects after hypnosis. These results suggest that individual differences in hypnotic susceptibility are linked with the efficiency of the frontal attention system, and that the hypnotized condition is characterized by a functional dissociation of conflict monitoring and cognitive control processes.

Human brain mechanisms of pain perception and regulation in health and disease

CONTEXT

The perception of pain due to an acute injury or in clinical pain states undergoes substantial processing at supraspinal levels. Supraspinal, brain mechanisms are increasingly recognized as playing a major role in the representation and modulation of pain experience. These neural mechanisms may then contribute to interindividual variations and disabilities associated with chronic pain conditions.

OBJECTIVE

To systematically review the literature regarding how activity in diverse brain regions creates and modulates the experience of acute and chronic pain states, emphasizing the contribution of various imaging techniques to emerging concepts.

DATA SOURCES

MEDLINE and PRE-MEDLINE searches were performed to identify all English-language articles that examine human brain activity during pain, using hemodynamic (PET, fMRI), neuroelectrical (EEG, MEG) and neurochemical methods (MRS, receptor binding and neurotransmitter modulation), from January 1, 1988 to March 1, 2003. Additional studies were identified through bibliographies.

STUDY SELECTION

Studies were selected based on consensus across all four authors. The criteria included well-designed experimental procedures, as well as landmark studies that have significantly advanced the field.

DATA SYNTHESIS

Sixty-eight hemodynamic studies of experimental pain in normal subjects, 30 in clinical pain conditions, and 30 using neuroelectrical methods met selection criteria and were used in a meta-analysis. Another 24 articles were identified where brain neurochemistry of pain was examined. Technical issues that may explain differences between studies across laboratories are expounded. The evidence for and the respective incidences of brain areas constituting the brain network for acute pain are presented. The main components of this network are: primary and secondary somatosensory, insular, anterior cingulate, and prefrontal cortices (S1, S2, IC, ACC, PFC) and thalamus (Th). Evidence for somatotopic organization, based on 10 studies, and psychological modulation, based on 20 studies, is discussed, as well as the temporal sequence of the afferent volley to the cortex, based on neuroelectrical studies. A meta-analysis highlights important methodological differences in identifying the brain network underlying acute pain perception. It also shows that the brain network for acute pain perception in normal subjects is at least partially distinct from that seen in chronic clinical pain conditions and that chronic pain engages brain regions critical for cognitive/emotional assessments, implying that this component of pain may be a distinctive feature between chronic and acute pain. The neurochemical studies highlight the role of opiate and catecholamine transmitters and receptors in pain states, and in the modulation of pain with environmental and genetic influences.

CONCLUSIONS

The nociceptive system is now recognized as a sensory system in its own right, from primary afferents to multiple brain areas. Pain experience is strongly modulated by interactions of ascending and descending pathways. Understanding these modulatory mechanisms in health and in disease is critical for developing fully effective therapies for the treatment of clinical pain conditions.

Hypnotherapy in the treatment of irritable bowel syndrome

There is accumulating and compelling evidence that hypnotherapy is an effective treatment for irritable bowel syndrome. Recently, studies have shown that hypnotherapy has beneficial effects that are long lasting, with most patients maintaining improvement, and with decreased consultation and medication needs in the long term. The particular gut directed approach used, which is aimed at normalizing and controlling gut function, is also described. While the mechanisms of how hypnotherapy brings about its therapeutic effect are not fully known, changes in colonic motility and rectal sensitivity have been demonstrated, although changes in central processing and psychological effects may also play a role.