Those with high baseline stress levels are more likely to develop mild cognitive impairment (MCI) and Alzheimer's Disease (AD). While meditation may reduce stress and alter the hippocampus and default mode network (DMN), little is known about its impact in these populations. Our objective was to conduct a “proof of concept” trial to determine whether Mindfulness Based Stress Reduction (MBSR) would improve DMN connectivity and reduce hippocampal atrophy among adults with MCI. 14 adults with MCI were randomized to MBSR vs. usual care and underwent resting state fMRI at baseline and follow-up. Seed based functional connectivity was applied using posterior cingulate cortex as seed. Brain morphometry analyses were performed using FreeSurfer. The results showed that after the intervention, MBSR participants had increased functional connectivity between the posterior cingulate cortex and bilateral medial prefrontal cortex and left hippocampus compared to controls. In addition, MBSR participants had trends of less bilateral hippocampal volume atrophy than control participants. These preliminary results indicate that in adults with MCI, MBSR may have a positive impact on the regions of the brain most related to MCI and AD. Further research with larger sample sizes and longer-follow-up are needed to further investigate the results from this pilot study.
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Using a common set of mindfulness exercises, mindfulness based stress reduction (MBSR) and mindfulness based cognitive therapy (MBCT) have been shown to reduce distress in chronic pain and decrease risk of depression relapse. These standardized mindfulness (ST-Mindfulness) practices predominantly require attending to breath and body sensations. Here, we offer a novel view of ST-Mindfulness's somatic focus as a form of training for optimizing attentional modulation of 7–14 Hz alpha rhythms that play a key role in filtering inputs to primary sensory neocortex and organizing the flow of sensory information in the brain. In support of the framework, we describe our previous finding that ST-Mindfulness enhanced attentional regulation of alpha in primary somatosensory cortex (SI). The framework allows us to make several predictions. In chronic pain, we predict somatic attention in ST-Mindfulness “de-biases” alpha in SI, freeing up pain-focused attentional resources. In depression relapse, we predict ST-Mindfulness's somatic attention competes with internally focused rumination, as internally focused cognitive processes (including working memory) rely on alpha filtering of sensory input. Our computational model predicts ST-Mindfulness enhances top-down modulation of alpha by facilitating precise alterations in timing and efficacy of SI thalamocortical inputs. We conclude by considering how the framework aligns with Buddhist teachings that mindfulness starts with “mindfulness of the body.” Translating this theory into neurophysiology, we hypothesize that with its somatic focus, mindfulness' top-down alpha rhythm modulation in SI enhances gain control which, in turn, sensitizes practitioners to better detect and regulate when the mind wanders from its somatic focus. This enhanced regulation of somatic mind-wandering may be an important early stage of mindfulness training that leads to enhanced cognitive regulation and metacognition.
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SummaryObjectives
To investigate neural representation evoked by acupuncture from human somatosensory cortices, especially from primary (SI) and secondary (SII) somatosensory areas.
Design and setting
Neuroimaging study – Blood-oxygenation-level-dependent (BOLD) functional MRI was performed during acupuncture on LI4 (n = 12 healthy participants). Sham acupuncture and innocuous tactile stimulation were also applied on the same acupuncture site as control comparisons.
Outcome measures
Responsive neural substrates were visualized and identified based on both individual and group-level surface activation maps.
Results
Discrete regions within the precentral gyrus (area 4) and the fundus of the central sulcus (area 3a) were selectively activated during the real acupuncture stimulation. In SII, the activation was extended in a postero-inferior direction to the fundus of the lateral sulcus.
Conclusion
This specific pattern of acupuncture-related activation indicates that deep tissue stimulation (as seen in area 3a activation) and concurrent processing of sensory stimulation (as seen in activation in SII) may mediate neural responses to manual acupuncture.
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Objective To explore participants’ experience in placebo-controlled randomized clinical trials (RCTs) specifically in relationship to their expectations. Background Aspects of being in RCTs, such as informed consent, perception of benefit and understanding of randomization, have been examined. In contrast, little is known concerning the formation of patient expectations before and during trials. Methods Qualitative methods using in-depth interviews with a semi-structured interview guide of nine patients from four different RCTs. Data analysis was conducted using a codebook format arranging participant responses under broad analytical headings. The interviewer used a semi-structured interview guide to direct the conversation from one broad topic to the next within the context of the ongoing conversation. A checklist of topics encouraged participants to describe their experiences in RCTs. Narratives concerning expectation, blinding and placebo were compared to identify common themes. Results Patient anticipatory processes were influenced and modified both before and during the trial from multiple inputs. Such factors as past experiences in RCTs, past experiences of ineffective treatment, stress of being off regular medications, fear of being a ‘placebo responder’, input of non-study doctors or other health professionals, the experience of other participants, measurements of health parameters made during the trial and the presence or absence of side-effects all affected patient expectation. Conclusion Expectations in RCTs are not fixed and instead may be viewed as continuously shaped by multiple inputs that include experience and information received both before and during the trial. Variability in placebo response observed in previous studies may be related to the fluid nature of expectations. Trying to control and equalize expectations in RCTs may be more difficult than previously assumed.
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Evidence that placebo acupuncture is an effective treatment for chronic pain presents a puzzle: how do placebo needles appearing to patients to penetrate the body, but instead sitting on the skin’s surface in the manner of a tactile stimulus, evoke a healing response? Previous accounts of ritual touch healing in which patients often described enhanced touch sensations (including warmth, tingling or flowing sensations) suggest an embodied healing mechanism. In this qualitative study, we asked a subset of patients in a singleblind randomized trial in irritable bowel syndrome to describe their treatment experiences while undergoing placebo treament. Analysis focused on patients’ unprompted descriptions of any enhanced touch sensations (e.g., warmth, tingling) and any significance patients assigned to the sensations. We found in 5/6 cases, patients associated sensations including “warmth” and “tingling” with treatment efficacy. The conclusion offers a “neurophenomenological” account of the placebo effect by considering dynamic effects of attentional filtering on early sensory cortices, possibly underlying the phenomenology of placebo acupuncture.
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Objective To investigate whether a sham device (a validated sham acupuncture needle) has a greater placebo effect than an inert pill in patients with persistent arm pain.
Design A single blind randomised controlled trial created from the two week placebo run-in periods for two nested trials that compared acupuncture and amitriptyline with their respective placebo controls. Comparison of participants who remained on placebo continued beyond the run-in period to the end of the study.
Setting Academic medical centre.
Participants 270 adults with arm pain due to repetitive use that had lasted at least three months despite treatment and who scored ≥3 on a 10 point pain scale.
Interventions Acupuncture with sham device twice a week for six weeks or placebo pill once a day for eight weeks.
Main outcomemeasures Arm pain measured on a 10 point pain scale. Secondary outcomes were symptoms measured by the Levine symptom severity scale, function measured by Pransky's upper extremity function scale, and grip strength.
Results Pain decreased during the two week placebo run-in period in both the sham device and placebo pill groups, but changes were not different between the groups (−0.14, 95% confidence interval −0.52 to 0.25, P = 0.49). Changes in severity scores for arm symptoms and grip strength were similar between groups, but arm function improved more in the placebo pill group (2.0, 0.06 to 3.92, P = 0.04). Longitudinal regression analyses that followed participants throughout the treatment period showed significantly greater downward slopes per week on the 10 point arm pain scale in the sham device group than in the placebo pill group (−0.33 (−0.40 to −0.26) v −0.15 (−0.21 to −0.09), P = 0.0001) and on the symptom severity scale (−0.07 (−0.09 to −0.05) v −0.05 (−0.06 to −0.03), P = 0.02). Differences were not significant, however, on the function scale or for grip strength. Reported adverse effects were different in the two groups.
Conclusions The sham device had greater effects than the placebo pill on self reported pain and severity of symptoms over the entire course of treatment but not during the two week placebo run in. Placebo effects seem to be malleable and depend on the behaviours embedded in medical rituals.
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The scientific discovery of novel training paradigms has yielded better understanding of basic mechanisms underlying cortical plasticity, learning and development. This study is a first step in evaluating Tai Chi (TC), the Chinese slow-motion meditative exercise, as a training paradigm that, while not engaging in direct tactile stimulus training, elicits enhanced tactile acuity in long-term practitioners. The rationale for this study comes from the fact that, unlike previously studied direct-touch tactile training paradigms, TC practitioners focus specific mental attention on the body’s extremities including the fingertips and hands as they perform their slow routine. To determine whether TC is associated with enhanced tactile acuity, experienced adult TC practitioners were recruited and compared to age–gender matched controls. A blinded assessor used a validated method (Van Boven et al. in Neurology 54(12): 2230–2236, 2000) to compare TC practitioners’ and controls’ ability to discriminate between two different orientations (parallel and horizontal) across different grating widths at the fingertip. Study results showed that TC practitioners’ tactile spatial acuity was superior to that of the matched controls (P < 0.04). There was a trend showing TC may have an enhanced effect on older practitioners (P < 0.066), suggesting that TC may slow age related decline in this measure. To the best of our knowledge, this is the first study to evaluate a long-term attentional practice’s effects on a perceptual measure. Longitudinal studies are needed to examine whether TC initiates or is merely correlated with perceptual changes and whether it elicits long-term plasticity in primary sensory cortical maps. Further studies should also assess whether related somatosensory attentional practices (such as Yoga, mindfulness meditation and Qigong) achieve similar effects.
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OBJECTIVES: This study aimed to compare the effects of true and sham acupuncture in relieving symptoms of irritable bowel syndrome (IBS).
METHODS: A total of 230 adult IBS patients (75% females, average age: 38.4 years) were randomly assigned to 3 weeks of true or sham acupuncture (6 treatments) after a 3-week "run-in" with sham acupuncture in an "augmented" or "limited" patient–practitioner interaction. A third arm of the study included a waitlist control group. The primary outcome was the IBS Global Improvement Scale (IBS-GIS) (range: 1–7); secondary outcomes included the IBS Symptom Severity Scale (IBS-SSS), the IBS Adequate Relief (IBS-AR), and the IBS Quality of Life (IBS-QOL).
RESULTS: Although there was no statistically significant difference between acupuncture and sham acupuncture on the IBS-GIS (41 vs. 32%, P=0.25), both groups improved significantly compared with the waitlist control group (37 vs. 4%, P=0.001). Similarly, small differences that were not statistically significant favored acupuncture over the other three outcomes: IBS-AR (59 vs. 57%, P=0.83), IBS-SSS (31 vs. 21%, P=0.18), and IBS-QOL (17 vs. 13%, P=0.56). Eliminating responders during the run-in period did not substantively change the results. Side effects were generally mild and only slightly greater in the acupuncture group.
CONCLUSIONS: This study did not find evidence to support the superiority of acupuncture compared with sham acupuncture in the treatment of IBS.
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