Patient\u2019s experience of altered body perception in musculoskeletal and rheumatic conditions

Objective. to investigate personal experience and perception of chronic musculoskeletal and rheumatic patients\u2019 own body, in order to better understand the complex relationship between the mind and the body in pain. Design and Method. a literature review has been conducted by two independent reviewers on Medline (PubMed) and PsycINFO, searching for records indexed until November 2017. \u2018Body perception\u2019, \u2018body representation\u2019, \u2018body schema\u2019, \u2018body image\u2019 and \u2018self image\u2019 have been the main keywords used for the search. No limits have been applied for language or date of publication. Results. the literature on body perception associated to painful experience in musculoskeletal and rheumatic diseases is scarce. Three studies have been analyzed. They investigated the complex relationship between the sense of self, the body and the pain on patients with Complex Regional Pain Syndrome, Fibromyalgia and Chronic Low Back Pain. The methodologies of investigation varied from interpretative-phenomenological analysis to the grounded-theory approach. The present analysis shows that the main themes reported by patients are phenomena of disturbed perception of own body parts, such as distortions in shape, pressure and altered awareness of limb position, coexisting with a compromised or distorted sense of self, such as hostile feelings, spectrum of dissociations and altered body image. Interestingly, a contradictory association between the high level of alertness demanded by pain and a diminished attention, neglect-like, toward the affected body part seems to be present in such conditions. Conclusions. The theme of the experience of the own body suffering, particularly regarding the perception of the body and the related emotions, seems to be scarcely investigated in musculoskeletal and rheumatic diseases. Further qualitative studies are needed to better understand neurocognitive aspects associated to musculoskeletal and rheumatic chronic painful conditions as osteoarthritis, rheumatoid arthritis, neck and shoulder pain in view of a clinical implementation of such information in terms of assessment and treatment

A new visual feedback-based system for the assessment of pinch force, endurance, accuracy and precision. A test-retest reliability study

Introduction: Given that pinch is a precision grip involved in sustained submaximal activities, a Sustained Contraction (SC) task could be associated to Maximal Voluntary Contraction (MVC). To better evaluate the thumb-index system, the test-retest reliability of pinch MVC and SC, measured by a visual feedback-based pinch gauge was assessed. Methods: 26 healthy participants performed MVC and SC in two separate sessions. SC required to maintain 40%MVC as long as possible and it was evaluated in terms of time, accuracy (Mean Distance between force trace and target force, MD), precision (Coefficient of Variability of force trace, CV). MD and CV analyses were conducted dividing the SC task into three equivalent time stages (beginning, middle, exhaustion). Relative Reliability (RR) was measured by Intraclass Correlation Coefficient, and Absolute Reliability (AR) was measured by Standard Error of Measurement and by Bland-Altman plot. Results: MVC and Time showed high RR and AR in both hands. RR of MD and CV in right hand was excellent in the beginning and middle stages, and fair in the exhaustion one, showing decreasing reliability as fatigue increases. In the left hand RR of MD and CV was generally lower. MD showed excellent reliability in the beginning stage and good reliability in the other stages. CV showed fair relative reliability at both beginning and middle stages, excellent in the last one. Conversely, it was observed high AR of MD and CV in all stages in both hands. Conclusions: All indices are reliable to assess motor control of thumb-index pinch in both hands

\u2018External timing\u2019 of placebo analgesia in an experimental model of sustained pain

Background: Research on placebo analgesia commonly focuses on the impact of information about direction (i.e., increase or decrease of pain) and magnitude of the expected analgesic effect, whereas temporal aspects of expectations have received little attention so far. In a recent study, using short-lasting, low-intensity stimuli, we demonstrated that placebo analgesia onset is influenced by temporal information. Here, we investigate whether the same effect of temporal suggestions can be found in longer lasting, high-intensity pain in a Cold Pressor Test (CPT). Methods: Fifty-three healthy volunteers were allocated to one of three groups. Participants were informed that the application of an (inert-)cream would reduce pain after 5 min (P5) or 30 min (P30). The third group was informed that the cream only had hydrating properties (NE). All participants completed the CPT at baseline and 10 (Test 10) and 35 min (Test 35) following cream application. Percentage change in exposure time (pain tolerance) from baseline to Test 10 (\u39410) and to Test 35 (\u39435) and changes in heart rate (HR) during CPT were compared between the three groups. Results: \u39410 was greater in P5 than in NE and P30, indicating that analgesia was only present in the group that was expecting an early onset of analgesia. \u39435 was greater in P5 and P30 compared to NE, reflecting a delayed onset of analgesia in P30 and maintained analgesia in P5. HR differences between groups were not significant. Conclusions: Our data suggest that \u2018externally timing\u2019 of placebo analgesia may be possible for prolonged types of pain. Significance: Research on placebo effects mainly focuses on the influence of information about direction (i.e., increase or decrease of pain) and magnitude (i.e., strong or weak) of the expected effect but ignores temporal aspects of expectations. In our study in healthy volunteers, the reported onset of placebo analgesia followed the temporal information provided. Such \u2018external timing\u2019 effects could not only aid the clinical use of placebo treatment (e.g., in open-label placebos) but also support the efficacy of active drugs

The Effect of Temporal Information on Placebo Analgesia and Nocebo Hyperalgesia

OBJECTIVE: Expectations are known to be key determinants of placebo and nocebo phenomena. In previous studies, verbal suggestions to induce such expectations have mainly focused on the direction and magnitude of the effect, whereas little is known about the influence of temporal information. METHODS: Using an experimental placebo and nocebo design, we investigated whether information about the expected onset of a treatment effect modulates the start and time course of analgesic and hyperalgesic responses. Healthy volunteers (n = 166) in three placebo and three nocebo groups were informed that the application of an (inert) cream would reduce (placebo groups) or amplify pain (nocebo groups) after 5, 15, or 30 minutes. Two control groups were also included (natural history and no expectations). Participants' pain intensity rating of electrical stimuli administered before and 10, 20, and 35 minutes after cream application was obtained. RESULTS: Mixed-method analysis of variance showed a significant interaction between group and time (F(12,262) = 18.172, p < .001, p\u3b72 = 0.454), suggesting that pain variations differed across time points and between groups. Post hoc comparisons revealed that the placebo and nocebo groups began to show a significantly larger change in perceived pain intensity than the no-expectancy control group at the expected time point (p < .05) but not earlier (p > .05). Once triggered, the analgesic effect remained constant over the course of the experiment, whereas the hyperalgesic effect increased over time. CONCLUSIONS: Our results indicate that temporal suggestions can shape expectancy-related treatment effects, which, if used systematically, could open up new ways to optimize treatment outcome