Meditation experience predicts less negative appraisal of pain: electrophysiological evidence for the involvement of anticipatory neural responses

The recurrent pain and sexual sequelae of provoked vestibulodynia: a perpetuating cycle

INTRODUCTION

Optimal management of provoked vestibulodynia (PVD), thought to be the most common form of chronic dyspareunia, is unclear.

AIM

To integrate recent brain data on chronic pain circuitry with stress-induced neuroendocrine mechanisms in the skin and the stress burden (allostatic load) of women with PVD; to also clarify the typical chronicity and negative sexual sequelae associated with PVD; and then review modulation of pain circuitry by cognitive therapy and mindfulness practice and apply to PVD management. Methods.  Review of scientific publications in the areas of sexual medicine, pain, brain imaging, gynecology, stress response, mindfulness, and cognitive behavioral therapy (CBT).

MAIN OUTCOME MEASURES

(i) A model of PVD to reflect its etiology, typical chronicity, and the detrimental effects on sexual function; (ii) Interventions of sexual rehabilitation based on principles underlying changes associated with CBT and mindfulness practice.

RESULTS

A model emerges which reflects how stress-induced changes of pain amplification (central sensitization), characteristic of chronic pain conditions, may impair sexual response in addition to sexual dysfunction that arises from conscious pain avoidance and/or fear-related inattention to sexual cues. Stress from low self-acceptance may be a major component of the allostatic load present in women with PVD, only to be exacerbated by the sexual dysfunction precipitated by the pain of intercourse. Mindfulness-based CBT appears promising to target both the pain and sexual suffering from PVD.

CONCLUSION

New findings on brain activity associated with recurrent clinical pain, functional brain changes associated with CBT and mindfulness, plus new data on stress systems within the skin along with data on increased stress load in women with PVD, support the use of mindfulness-based CBT for the recurrent pain and sexual suffering from PVD.

Mindfulness meditation-related pain relief: evidence for unique brain mechanisms in the regulation of pain

The cognitive modulation of pain is influenced by a number of factors ranging from attention, beliefs, conditioning, expectations, mood, and the regulation of emotional responses to noxious sensory events. Recently, mindfulness meditation has been found attenuate pain through some of these mechanisms including enhanced cognitive and emotional control, as well as altering the contextual evaluation of sensory events. This review discusses the brain mechanisms involved in mindfulness meditation-related pain relief across different meditative techniques, expertise and training levels, experimental procedures, and neuroimaging methodologies. Converging lines of neuroimaging evidence reveal that mindfulness meditation-related pain relief is associated with unique appraisal cognitive processes depending on expertise level and meditation tradition. Moreover, it is postulated that mindfulness meditation-related pain relief may share a common final pathway with other cognitive techniques in the modulation of pain.

Electrocortical activity prior to unpredictable stimuli in meditators and nonmeditators

Advanced meditators occasionally report experiences of timelessness, or states of awareness that seem to transcend the usual boundaries of the subjective present. This type of experience was investigated in eight experienced meditators and eight matched controls by measuring 32 channels of EEG before, during, and after exposure to unpredictable light and sound stimuli. The experiment postulated that if some aspect of consciousness extends beyond the present moment, then prestimulus electrocortical signals should differ depending on stimuli that were about to be selected by a truly random process, and that if such experiences were catalyzed through meditation practice, then prestimulus differences should be more apparent in meditators than in nonmeditators. Each of the 32 EEG channels was baseline adjusted on each trial by the electrical potential averaged between two- and one-second prestimulus, then for each channel the average potential was determined from one-second prestimulus to stimulus onset. The resulting means across subjects in each group were compared by stimulus type using randomized permutation procedures and corrected for multiple comparisons. Within the control group, no EEG channels showed significant prestimulus differences between light versus sound stimulus conditions, but within the meditator group five of 32 channels resulted in significant differences (P < .05, two tailed). Comparisons between control and meditator groups showed significant prestimulus differences prior to audio tone stimuli in 14 of 32 channels (P < .05, two tailed, of which eight channels were P < .005, two tailed). This outcome successfully replicates effects reported in earlier experiments, suggesting that sometimes the subjective sense of awareness extending into the future may be ontologically accurate.

Pain attenuation through mindfulness is associated with decreased cognitive control and increased sensory processing in the brain

Pain can be modulated by several cognitive techniques, typically involving increased cognitive control and decreased sensory processing. Recently, it has been demonstrated that pain can also be attenuated by mindfulness. Here, we investigate the underlying brain mechanisms by which the state of mindfulness reduces pain. Mindfulness practitioners and controls received unpleasant electric stimuli in the functional magnetic resonance imaging scanner during a mindfulness and a control condition. Mindfulness practitioners, but not controls, were able to reduce pain unpleasantness by 22% and anticipatory anxiety by 29% during a mindful state. In the brain, this reduction was associated with decreased activation in the lateral prefrontal cortex and increased activation in the right posterior insula during stimulation and increased rostral anterior cingulate cortex activation during the anticipation of pain. These findings reveal a unique mechanism of pain modulation, comprising increased sensory processing and decreased cognitive control, and are in sharp contrast to established pain modulation mechanisms.

The validation of an active control intervention for Mindfulness Based Stress Reduction (MBSR)

Most of the extant literature investigating the health effects of mindfulness interventions relies on wait-list control comparisons. The current article specifies and validates an active control condition, the Health Enhancement Program (HEP), thus providing the foundation necessary for rigorous investigations of the relative efficacy of Mindfulness Based Stress Reduction (MBSR) and for testing mindfulness as an active ingredient. 63 participants were randomized to either MBSR (n = 31) or HEP (n = 32). Compared to HEP, MBSR led to reductions in thermal pain ratings in the mindfulness- but not the HEP-related instruction condition (η(2) = .18). There were significant improvements over time for general distress (η(2) = .09), anxiety (η(2) = .08), hostility (η(2) = .07), and medical symptoms (η(2) = .14), but no effects of intervention. Practice was not related to change. HEP is an active control condition for MBSR while remaining inert to mindfulness. These claims are supported by results from a pain task. Participant-reported outcomes (PROs) replicate previous improvements to well-being in MBSR, but indicate that MBSR is no more effective than a rigorous active control in improving these indices. These results emphasize the importance of using an active control condition like HEP in studies evaluating the effectiveness of MBSR.

Brain mechanisms supporting the modulation of pain by mindfulness meditation

The subjective experience of one's environment is constructed by interactions among sensory, cognitive, and affective processes. For centuries, meditation has been thought to influence such processes by enabling a nonevaluative representation of sensory events. To better understand how meditation influences the sensory experience, we used arterial spin labeling functional magnetic resonance imaging to assess the neural mechanisms by which mindfulness meditation influences pain in healthy human participants. After 4 d of mindfulness meditation training, meditating in the presence of noxious stimulation significantly reduced pain unpleasantness by 57% and pain intensity ratings by 40% when compared to rest. A two-factor repeated-measures ANOVA was used to identify interactions between meditation and pain-related brain activation. Meditation reduced pain-related activation of the contralateral primary somatosensory cortex. Multiple regression analysis was used to identify brain regions associated with individual differences in the magnitude of meditation-related pain reductions. Meditation-induced reductions in pain intensity ratings were associated with increased activity in the anterior cingulate cortex and anterior insula, areas involved in the cognitive regulation of nociceptive processing. Reductions in pain unpleasantness ratings were associated with orbitofrontal cortex activation, an area implicated in reframing the contextual evaluation of sensory events. Moreover, reductions in pain unpleasantness also were associated with thalamic deactivation, which may reflect a limbic gating mechanism involved in modifying interactions between afferent input and executive-order brain areas. Together, these data indicate that meditation engages multiple brain mechanisms that alter the construction of the subjectively available pain experience from afferent information.

Mindfulness meditation: a primer for rheumatologists

Over the past decade, there has been an increasing interest in meditation as a mind-body approach, given its potential to alleviate emotional distress and promote improved well being in a variety of populations. The overall purpose of this review is to provide the practicing rheumatologist with an overview of mindfulness and how it can be applied to Western medical treatment plans to enhance both the medical and psychological care of patients.