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Background and objective: This systematic, rapid review aimed to critically appraise and synthesize the recent literature (2014–2019) evaluating the incidence and prevalence of post-amputation phantom limb pain (PLP) and sensation (PLS). Databases and data treatment: Five databases (Medline, Embase, Emcare, PsychInfo, Web of Science) and Google Scholar were searched, with two independent reviewers completing eligibility screening, risk of bias assessment and data extraction. Results: The search identified 1,350 studies with 12 cross-sectional and 3 prospective studies included. Studies evaluated traumatic (n = 5), atraumatic (n = 4), and combined traumatic/atraumatic (n = 6) amputee populations, ranging from 1 month to 33 years post-amputation. Study heterogeneity prevented data pooling. The majority of studies had a high risk of bias, primarily due to limited generalizability. Three studies evaluated PLP incidence, ranging from 2.2% (atraumatic; 1 month) to 41% (combined; 3 months) and 82% (combined; 12 months). Only one study evaluated PLS/telescoping incidence. Across contrasting populations, PLP point prevalence was between 6.7%–88.1%, 1 to 3-month period prevalence was between 49%-93.5%, and lifetime prevalence was high at 76%–87%. Point prevalence of PLS was 32.4%-90%, period prevalence was 65% (1 month) and 56.9% (3 months), and lifetime prevalence was 87%. Telescoping was less prevalent, highest among traumatic amputees (24.6%) within a 1-month prevalence period. Variations in population type (e.g. amputation characteristics) and incidence and prevalence measures likely influence the large variability seen here. Conclusions: This review found that lifetime prevalence was the highest, with most individuals experiencing some type of phantom phenomena at some point post-amputation. Significance: This systematic rapid review provides a reference for clinicians to make informed prognosis estimates of phantom phenomena for patients undergoing amputation. Results show that most amputees will experience phantom limb pain (PLP) and phantom limb sensations (PLS): high PLP incidence 1-year post-amputation (82%); high lifetime prevalence for PLP (76%–87%) and PLS (87%). Approximately 25% of amputees will experience telescoping. Consideration of individual patient characteristics (cause, amputation site, pre-amputation pain) is pertinent given their likely contribution to incidence/prevalence of phantom phenomena. Refereed/Peer-reviewed

Background: Burning mouth syndrome (BMS) is a chronic pain disorder affecting the oral cavity. Previous work has shown promising analgesic results of bodily illusions in other chronic pain conditions. The aim of this proof‐of‐concept, pilot study was to investigate whether bodily illusions reduce pain in BMS patients. Methods: Nine participants diagnosed with BMS underwent bodily illusions using a MIRAGE‐mediated reality system. All participants completed 4 conditions and performed standardised movements of the tongue. First, a baseline condition was performed while the tongue was viewed at normal size and colour. Then, three conditions were performed in random order: resizing shrink, colour‐based (blue tongue), and incongruent movement illusions. During each condition, participants rated overall pain intensity as well as the intensity of burning pain/sensation on the tongue. Results: There was no difference in overall pain intensity ratings between conditions. However, a significant effect of condition was found for burning pain/sensation of the tongue. The colour illusion significantly reduced burning pain compared with baseline (MD = ‐12.8, 95% CI ‐20.7 to ‐4.8), corresponding to an average pain reduction of 32%. Exploratory analyses showed the colour illusion also significantly reduced pain compared with the shrink illusion (MD = ‐11.7, 95% CI ‐22.2 to ‐1.1). Conclusion: Using visual illusions to change tongue colour to blue resulted in significant reductions in burning pain/sensations in BMS patients for the duration of the illusion. This proof‐of‐concept study suggests that BMS patients may benefit from bodily illusions, and supports additional research using larger samples and more comprehensive control conditions. Refereed/Peer-reviewed

Background: There is a growing interest in the role of disturbed body perception in people with persistent pain problems such as chronic low back pain (CLBP). A questionnaire, the Fremantle Back Awareness Questionnaire (FreBAQ), was recently developed as a simple and quick way of assessing disturbed perceptual awareness of the back in people with CLBP and appears to have acceptable psychometric properties. The aim of the present study was to develop a Japanese version of the FreBAQ (FreBAQ-J) and evaluate its psychometric properties in a sample of Japanese people with low back pain (LBP). Methods: Translation of the FreBAQ into Japanese was conducted using a forward-backward method. One hundred participants with LBP completed the resultant FreBAQ-J. A subset of the participants completed the FreBAQ-J again 2 weeks later. Validity was investigated by examining the relationship between the FreBAQ-J and clinical valuables. Rasch analysis was used to assess targeting, category ordering, unidimensionality, person fit, internal consistency, and differential item functioning. Results: The FreBAQ-J was significantly correlated with pain in motion, disability, pain-related catastrophizing, fear of movement, and anxiety symptomatology. The FreBAQ-J had acceptable internal consistency, a minor departure from unidimensionality, and good test-retest reliability, and was functional on the category rating scale. Conclusions: The FreBAQ-J has acceptable psychometric properties and is suitable for use in people with LBP. Participants with high levels of disturbed body perception are well targeted by the scale. The functioning of one item (item 8) was poor. Further study is warranted to confirm if this item should be excluded. Refereed/Peer-reviewed

It is widely accepted that complex regional pain syndrome (CRPS) is associated with shrink- age of the primary somatosensory cortex (S1) representation of the affected limb. However, supporting evidence is surprisingly limited and may be compromised by high risk of bias. This study compared the S1 spatial representation of the hand in 17 patients with upper-limb CRPS to 16 healthy controls, using functional MRI. Innocuous vibration was delivered to digits one (D1) and five (D5) in a block- design. Resultant activation maxima were located within a bilateral S1 mask, determined a priori. Dis- tance between D1 and D5 activation maxima, calculated for both hands, was used as a measure of S1 representation. Analyses were blinded to group and hand. In patients, S1 representation was smaller for the affected hand than it was for the healthy hand (t(11) 52.02, P 50.03), as predicted. However, S1 representation of the affected hand was no different to that of either hand in controls. Critically, S1 representation of the healthy hand of patients was larger than that of controls' hands. CRPS seems to be associated with an enlarged representation of the healthy hand, not a smaller representation of the affected hand. These findings raise important questions about neuroplasticity in CRPS. Hum Brain

This is the peer reviewed version of the following article: The Cochrane database of systematic reviews, which has been published in final form at https://doi.org/10.1002/14651858.CD004598.pub4. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Background: This review is an update of a previously published review in the Cochrane Database of Systematic Reviews, 2005, Issue 4 (and last updated in the Cochrane Database of Systematic Reviews, 2013 issue 8), on local anaesthetic blockade (LASB) of the sympathetic chain to treat people with complex regional pain syndrome (CRPS). Objectives: To assess the efficacy of LASB for the treatment of pain in CRPS and to evaluate the incidence of adverse effects of the procedure. Search methods: For this update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 9), MEDLINE (Ovid), EMBASE (Ovid), LILACS (Birme), conference abstracts of the World Congresses of the International Association for the Study of Pain, and various clinical trial registers up to September 2015. We also searched bibliographies from retrieved articles for additional studies. Selection criteria: We considered randomised controlled trials (RCTs) that evaluated the effect of sympathetic blockade with local anaesthetics in children or adults with CRPS compared to placebo, no treatment, or alternative treatments. Data collection and analysis: We used standard methodological procedures expected by Cochrane. The outcomes of interest were reduction in pain intensity, the proportion who achieved moderate or substantial pain relief, the duration of pain relief, and the presence of adverse effects in each treatment arm. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created a 'Summary of findings' table. Main results: We included an additional four studies (N = 154) in this update. For this update, we excluded studies that did not follow up patients for more than 48 hours. As a result, we excluded four studies from the previous review in this update. Overall we included 12 studies (N = 461), all of which we judged to be at high or unclear risk of bias. Overall, the quality of evidence was low to very low, downgraded due to limitations, inconsistency, imprecision, indirectness, or a combination of these. Two small studies compared LASB to placebo/sham (N = 32). They did not demonstrate significant short-term benefit for LASB for pain intensity (moderate quality evidence). One small study (N = 36) at high risk of bias compared thoracic sympathetic block with corticosteroid and local anaesthetic versus injection of the same agents into the subcutaneous space, reporting statistically significant and clinically important differences in pain intensity at one-year follow-up but not at short term follow-up (very low quality evidence). Of two studies that investigated LASB as an addition to rehabilitation treatment, the only study that reported pain outcomes demonstrated no additional benefit from LASB (very low quality evidence). Eight small randomised studies compared sympathetic blockade to various other active interventions. Most studies found no difference in pain outcomes between sympathetic block versus other active treatments (low to very low quality evidence). One small study compared ultrasound-guided LASB with non-guided LASB and found no clinically important difference in pain outcomes (very low quality evidence). Six studies reported adverse events, all with minor effects reported. Authors' conclusions: This update's results are similar to the previous versions of this systematic review, and the main conclusions are unchanged. There remains a scarcity of published evidence and a lack of high quality evidence to support or refute the use of local anaesthetic sympathetic blockade for CRPS. From the existing evidence, it is not possible to draw firm conclusions regarding the efficacy or safety of this intervention, but the limited data available do not suggest that LASB is effective for reducing pain in CRPS.