Neural Mechanisms of Hypnosis and Meditation-Induced Analgesia: A Narrative Review

Effects of meditation on neural responses to pain: A systematic review and meta-analysis of fMRI studies

This systematic review investigates the impact of meditation on neural responses to pain, as measured by functional magnetic resonance imaging (fMRI). Up to March 2024, we conducted searches across four databases for human studies implementing fMRI to assess the efficacy of meditation for pain relief. Eighteen studies met the inclusion criteria. Our systematic review indicates that activation of the insula, anterior cingulate cortex, and orbitofrontal cortex is positively associated with meditation for pain relief, while activity in regions like the amygdala and medial prefrontal cortex is negatively correlated with pain relief. Meta-analyses consistently reveal the involvement of various brain regions, including the insula, putamen, amygdala, anterior cingulate cortex, precentral gyrus, postcentral gyrus, inferior parietal lobule, superior temporal gyrus, inferior frontal gyrus, and caudate nucleus, in meditation-induced alleviation of pain. These findings suggest ccthat meditation acts on specific brain regions related to pain, mood, and cognition, providing insight into the potential mechanisms underlying the pain-alleviating effects of meditation on both pain sensations and emotional experiences.

The Role of Electroencephalogram-Assessed Bandwidth Power in Response to Hypnotic Analgesia

Research supports the efficacy of therapeutic hypnosis for reducing acute and chronic pain. However, little is known about the mechanisms underlying these effects. This paper provides a review of the evidence regarding the role that electroencephalogram-assessed bandwidth power has in identifying who might benefit the most from hypnotic analgesia and how these effects occur. Findings are discussed in terms of the slow wave hypothesis, which posits that brain activity in slower bandwidths (e.g., theta and alpha) can facilitate hypnosis responsivity. Although the extant research is limited by small sample sizes, the findings from this research are generally consistent with the slow wave hypothesis. More research, including and especially studies with larger sample sizes, is needed to confirm these preliminary positive findings.

Variations of the Relative Parasympathetic Tone Assessed by ANI During Oocyte Retrieval Under Local Anaesthesia with Virtual Reality : A Randomized, Controlled, Monocentric, Open Study

Transvaginal oocyte retrieval is an outpatient procedure performed under local anaesthesia. Hypno-analgesia could be effective in managing comfort during this procedure. This study aimed to assess the effectiveness of a virtual reality headset as an adjunct to local anaesthesia in managing nociception during oocyte retrieval. This was a prospective, randomized single-centre study including patients undergoing oocyte retrieval under local anaesthesia. Patients were randomly assigned to the intervention group (virtual reality headset + local anaesthesia) or the control group (local anaesthesia). The primary outcome was the efficacy on the ANI®, which reflects the relative parasympathetic tone. Secondary outcomes included pain, anxiety, conversion to general anaesthesia rate, procedural duration, patient's and gynaecologist's satisfaction and virtual reality headset tolerance. ANI was significantly lower in the virtual reality group during the whole procedure (mean ANI: 79 95 CI [77; 81] vs 74 95 CI [72; 76]; p < 0.001; effect size Cohen's d -0.53 [-0.83, -0.23]), and during the two most painful moments: infiltration (mean ANI: 81 +/- 11 vs 74 +/- 13; p < 0.001; effect size Cohen's d -0.54[-0.85, -0.24]) and oocytes retrieval (mean ANI: 78 +/- 11 vs 74.40 +/- 11; p = 0.020; effect size Cohen's d -0.37 [-0.67, -0.07]).There was no significant difference in pain measured by VAS. No serious adverse events related were reported. The integration of virtual reality as an hypnotic tool during oocyte retrieval under local anaesthesia in assisted reproductive techniques could improve patient's comfort and experience.

Brain Functional Correlates of Resting Hypnosis and Hypnotizability: A Review

This comprehensive review delves into the cognitive neuroscience of hypnosis and variations in hypnotizability by examining research employing functional magnetic resonance imaging (fMRI), positron emission tomography (PET), and electroencephalography (EEG) methods. Key focus areas include functional brain imaging correlations in hypnosis, EEG band oscillations as indicators of hypnotic states, alterations in EEG functional connectivity during hypnosis and wakefulness, drawing critical conclusions, and suggesting future research directions. The reviewed functional connectivity findings support the notion that disruptions in the available integration between different components of the executive control network during hypnosis may correspond to altered subjective appraisals of the agency during the hypnotic response, as per dissociated and cold control theories of hypnosis. A promising exploration avenue involves investigating how frontal lobes' neurochemical and aperiodic components of the EEG activity at waking-rest are linked to individual differences in hypnotizability. Future studies investigating the effects of hypnosis on brain function should prioritize examining distinctive activation patterns across various neural networks.

Effect of Hypnosis on Pain, Anxiety, and Quality of Life in Female Patients with Fibromyalgia: Prospective, Randomized, Controlled Study

This prospective, randomized, controlled study aimed to investigate the effects of standardized adjuvant hypnosis on pain, depression, anxiety, aerobic exercise practices, quality of life, and disease impact score in female patients with fibromyalgia syndrome (FMS). This study included 47 female patients with FMS who had been under treatment for at least six months. The hypnosis group (n = 24) received a total of three hypnosis sessions and was taught to patients' self-hypnosis. The patients in this group practiced self-hypnosis for six months. During this period, all patients also continued their medical treatment. The Visual Analogue Scale (VAS) was used to determine the intensity of pain. At the end of the six-month follow-up period, it was determined that the patients of FMS with hypnosis therapy had lower pain intensity, FMS symptoms, depression, and anxiety symptoms, and better well-being than those in the control group (p < .05). Standardized hypnosis is an effective method in reducing pain, depression and anxiety symptoms and improving quality of life in patients with FMS.

Real-time assessment of hypnotic depth, using an EEG-based brain-computer interface: a preliminary study

OBJECTIVE

Hypnosis can be an effective treatment for many conditions, and there have been attempts to develop instrumental approaches to continuously monitor hypnotic state level ("depth"). However, there is no method that addresses the individual variability of electrophysiological hypnotic correlates. We explore the possibility of using an EEG-based passive brain-computer interface (pBCI) for real-time, individualised estimation of the hypnosis deepening process.

RESULTS

The wakefulness and deep hypnosis intervals were manually defined and labelled in 27 electroencephalographic (EEG) recordings obtained from eight outpatients after hypnosis sessions. Spectral analysis showed that EEG correlates of deep hypnosis were relatively stable in each patient throughout the treatment but varied between patients. Data from each first session was used to train classification models to continuously assess deep hypnosis probability in subsequent sessions. Models trained using four frequency bands (1.5-45, 1.5-8, 1.5-14, and 4-15 Hz) showed accuracy mostly exceeding 85% in a 10-fold cross-validation. Real-time classification accuracy was also acceptable, so at least one of the four bands yielded results exceeding 74% in any session. The best results averaged across all sessions were obtained using 1.5-14 and 4-15 Hz, with an accuracy of 82%. The revealed issues are also discussed.

A whole new world of healing: exploring medical hypnotherapy for pediatric patients : A review

This narrative review aims to unravel the potential of medical hypnotherapy for the treatment of children with a variety of diseases and symptoms. Going beyond its history and assumed neurophysiology, the chances of success for hypnotherapy will be outlined per pediatric speciality, accentuated by clinical research and experiences. Future implications and recommendations are given on extracting the positive effects of medical hypnotherapy for all pediatricians.    Conclusion: Medical hypnotherapy is an effective treatment for children with specified conditions such as abdominal pain or headache. Studies suggest effectiveness for other pediatric disciplines, from the first line up to third line of care. In a time in which health is defined as 'a state of complete physical, mental and social well-being', hypnotherapy stays an underrated treatment option for children. It is a unique mind-body treatment, which true potential still needs to be unraveled. What is Known: • Mind-body health techniques become a more relevant and accepted part of treatment in pediatric patients. • Medical hypnotherapy is an effective treatment for children with specified conditions such as functional abdominal pain. What is New: • Studies suggest the effectiveness of hypnotherapy in a high variety of pediatric symptoms and disease. • Hypnotherapy is a unique mind-body treatment which potential goes far beyond its current utilization.

Direct comparisons between hypnosis and meditation: A mini-review

Hypnosis and meditation share phenomenological and neurophysiological features, and their comparison is a topic of growing interest in the scientific literature. In this article, we review a classification of these two kinds of non-ordinary states of consciousness, and discuss the studies that directly compare them. Some findings seem to suggest that hypnosis and meditation are distinct phenomena, while others underline their similarities, but experiments that directly contrast them are still scarce and no consensus has been reached yet. While this comparison could give us fundamental insights into central issues concerning the role of attention, metacognition and executive control in the study of consciousness, it is clear that we are still at the early stages of this research.

Hypnosis, Meditation, and Self-Induced Cognitive Trance to Improve Post-treatment Oncological Patients' Quality of Life: Study Protocol

Introduction

A symptom cluster is very common among oncological patients: cancer-related fatigue (CRF), emotional distress, sleep difficulties, pain, and cognitive difficulties. Clinical applications of interventions based on non-ordinary states of consciousness, mostly hypnosis and meditation, are starting to be investigated in oncology settings. They revealed encouraging results in terms of improvements of these symptoms. However, these studies often focused on breast cancer patients, with methodological limitations (e.g., small sample size, no control group, and no follow-up). Another non-ordinary state of consciousness may also have therapeutic applications in oncology: self-induced cognitive trance (SICT). It seems to differ from hypnosis and meditation, as it involves the body more directly. Thus, investigating its clinical applications, along with hypnosis and meditation interventions, could improve available therapeutic options in oncology. This article details the study protocol of a preference-based longitudinal controlled superiority trial aiming to assess the effectiveness of 3 group interventions (hypnosis, meditation, and SICT) to improve oncological patients’ quality of life, and more specifically CRF, emotional distress, sleep, pain, and cognitive difficulties (primary outcomes).

Methods and analysis

A power analysis required a total sample of 160 patients. Main inclusion criteria are: cancer diagnosis, active treatments completed for less than a year, no practice of hypnosis, meditation, or SICT, and presence of at least one of these four symptoms: fatigue, sleep difficulties, depression, or anxiety. Each participant will choose the intervention in which they want to participate (hypnosis, mindful self-compassion meditation, SICT, or no intervention—control group). To test the effectiveness of the interventions, data will be collected by questionnaires and neurobiological measures and directly from the medical record at four time points: before inclusion in the study (baseline); immediately after the intervention; and at 3- and 12-month follow-up. The longitudinal data in each group will then be measured.

Discussion

In addition to standard cancer therapies, there is a growing interest from patients in complementary approaches, such as hypnosis, meditation, and SICT. The results of this study will be useful to increase knowledge about short- and long-term effectiveness of 3 group interventions for CRF, emotional distress, sleep, pain, and cognitive difficulties in patients with different cancers.

Clinical Trial Registration

ClinicalTrials.gov/ (NCT04873661). Retrospectively registered on the 29th of April 2021. url: https://clinicaltrials.gov/ct2/show/NCT04873661

Functional Changes in Brain Activity Using Hypnosis: A Systematic Review

Hypnosis has proven a powerful method in indications such as pain control and anxiety reduction. As recently discussed, it has been yielding increased attention from medical/dental perspectives. This systematic review (PROSPERO-registration-ID-CRD42021259187) aimed to critically evaluate and discuss functional changes in brain activity using hypnosis by means of different imaging techniques. Randomized controlled trials, cohort, comparative, cross-sectional, evaluation and validation studies from three databases—Cochrane, Embase and Medline via PubMed from January 1979 to August 2021—were reviewed using an ad hoc prepared search string and following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. A total of 10,404 articles were identified, 1194 duplicates were removed and 9190 papers were discarded after consulting article titles/abstracts. Ultimately, 20 papers were assessed for eligibility, and 20 papers were included after a hand search (n^total = 40). Despite a broad heterogenicity of included studies, evidence of functional changes in brain activity using hypnosis was identified. Electromyography (EMG) startle amplitudes result in greater activity in the frontal brain area; amplitudes using Somatosensory Event-Related Potentials (SERPs) showed similar results. Electroencephalography (EEG) oscillations of θ activity are positively associated with response to hypnosis. EEG results showed greater amplitudes for highly hypnotizable subjects over the left hemisphere. Less activity during hypnosis was observed in the insula and anterior cingulate cortex (ACC).

Dorsolateral prefrontal cortex sensing analgesia

Chronic pain often has an unknown cause, and many patients with chronic pain learn to accept that their pain is incurable and pharmacologic treatments are only temporarily effective. Complementary and integrative health approaches for pain are thus in high demand. One such approach is soft touch, e.g., adhesion of pyramidal thorn patches in a pain region. The effects of patch adhesion on pain relief have been confirmed in patients with various types of pain. A recent study using near-infrared spectroscopy revealed that the dorsolateral prefrontal cortex (DLPFC), especially the left side, is likely to be inactivated in patients experiencing pain relief during patch treatment. Mindfulness meditation is another well-known complementary and integrative approach for achieving pain relief. The relation between pain relief due to mindfulness meditation and changes in brain regions, including the DLPFC, has long been examined. In the present review article, we survey the literature describing the effects of the above-mentioned complementary and integrative treatments on pain relief, and outline the important brain regions, including the DLPFC, that are involved in analgesia. We hope that the present article will provide clues to researchers who hope to advance neurosensory treatments for pain relief without medication.