Painful and nonpainful phantom and stump sensations in acute traumatic amputees. ACTA ACUST UNITED AC. 2008;65:858-864. [PMID: 18849803 DOI: 10.1097/ta.0b013e31812eed9e]

The efficacy of topical oxygen therapy for wound healing: A meta-analysis of randomized controlled trials and observational studies

In preclinical studies, topical oxygen treatment (TOT) was shown to enhance wound healing by applying supplemental oxygen topically to the surface of a moist wound at normobaric conditions. The objective of this systematic review and meta-analysis is to provide a thorough evaluation of published RCTs and observational studies that compare supplemental TOT with standard wound care. A total of 1077 studies were obtained from a variety of databases, including PubMed, ScienceDirect, Web of Science, ProQuest, Scopus, ClinicalTrials.gov, EU Clinical Trial Registers, and Preprints.org. The Jadad scale was employed to assess the reliability of RCT studies, while the Newcastle-Ottawa Scale (NOS) was employed to assess the quality of observational studies. Seven RCT studies (n = 692) and two controlled observational studies (n = 111) were analysed. The rate of healed wounds was 25.8% in the control group and 43.25% in the adjuvant TOT group, which shows the use of TOT significantly increased the number of healed wounds (RR = 1.77; 95% CI 1.18-2.64; p = 0.005). A significant decrease in the percentage of wound area was found in the TOT group in RCT studies (mean difference = 15.64; 95% CI 5.22-26.06; p = 0.003). In observational studies, the rate of healed wounds was 37.5% in the standard care group and 80.95% in the adjuvant TOT group, which shows a significant increase in the number of healed wounds in the adjuvant TOT group (RR = 2.15; 95% CI 1.46-3.15; p < 0.00001). Topical oxygen therapy is considered a great adjuvant therapy for chronic wound healing, particularly wounds with vascular compromise such as diabetic ulcers and pressure ulcers. Further studies on this topic are still needed as there are a lot of potential uses for this technology in various types of wounds.

Percutaneous treatments for residual and/or phantom limb pain in adults with lower-extremity amputations: A narrative review

Residual limb pain (RLP) and phantom limb pain (PLP) profoundly affect the lives of many individuals who have undergone lower- or upper-extremity amputation. Despite the considerable impact of RLP/PLP on quality of life in persons with amputation, there have been few attempts to evaluate the efficacy of percutaneous interventions in the treatment of RLP and/or PLP. This narrative review evaluates the effectiveness of percutaneous treatments for RLP and/or PLP in patients after lower-extremity amputation. Peripheral nerve stimulation, alcohol neurolysis, conventional thermal radiofrequency ablation, perineural corticosteroid injection, botulinum toxin injection, and etanercept injection were associated with varying success rates. Wide confidence intervals and small treatment cohorts impede assessments of overall success. High-quality studies of nonsurgical, percutaneous treatments for RLP and/or PLP are lacking. Well-designed randomized controlled trials and large cohort studies with comparison groups using validated outcomes are needed to determine the effectiveness of nonsurgical interventions for the treatment of RLP and PLP.

An Algorithm Approach to Phantom Limb Pain

Phantom limb pain (PLP) is a common condition that occurs following both upper and lower limb amputation. First recognized and described in 1551 by Ambroise Pare, research into its underlying pathology and effective treatments remains a very active and growing field. To date, however, there is little consensus regarding the optimal management of phantom limb pain. With few large well-designed clinical trials of which to make treatment recommendations, as well as significant heterogeneity in clinical response to available treatments, the management of PLP remains challenging. Below we summarize the current state of knowledge in the field, as well as propose an algorithm for the approach to the treatment of PLP.

Variation on a technique for the intra-muscular insertion of nerve endings to minimise neuropathic and residual pain in lower limb amputees: a retrospective cohort study

INTRODUCTION

A major cause of morbidity in lower limb amputees is phantom limb pain (PLP) and residual limb pain (RLP). This study aimed to determine whether a variation of the surgical technique of inserting nerve endings into adjacent muscle bellies at the time of lower limb amputation can decrease the incidence and severity of PLP and RLP.

METHODS

Data were retrospectively collected from January 2015 to January 2021, including eight patients that underwent nerve insertion (NI) and 36 that received standard treatment. Primary outcomes included the 11-point Numerical Rating Scale (NRS) for pain severity, and Patient-Reported Outcomes Measurement Information System (PROMIS) pain intensity, behaviour, and interference. Secondary outcome included Neuro-QoL Lower Extremity Function assessing mobility. Cumulative scores were transformed to standardised t scores.

RESULTS

Across all primary and secondary outcomes, NI patients had lower PLP and RLP. Mean 'worst pain' score was 3.5 out of 10 for PLP in the NI cohort, compared to 4.89 in the control cohort (p = 0.298), and 2.6 out of 10 for RLP in the NI cohort, compared to 4.44 in the control cohort (p = 0.035). Mean 'best pain' and 'current pain' scores were also superior in the NI cohort for PLP (p = 0.003, p = 0.022), and RLP (p = 0.018, p = 0.134). Mean PROMIS t scores were lower for the NI cohort for RLP (40.1 vs 49.4 for pain intensity; p = 0.014, 44.4 vs 48.2 for pain interference; p = 0.085, 42.5 vs 49.9 for pain behaviour; p = 0.025). Mean PROMIS t scores were also lower for the NI cohort for PLP (42.5 vs 52.7 for pain intensity; p = 0.018); 45.0 vs 51.5 for pain interference; p = 0.015, 46.3 vs 51.1 for pain behaviour; p = 0.569). Mean Neuro-QoL t score was lower in NI cohort (45.4 vs 41.9; p = 0.03).

CONCLUSION

Surgical insertion of nerve endings into adjacent muscle bellies during lower limb amputation is a simple yet effective way of minimising PLP and RLP, improving patients' subsequent quality of life. Additional comparisons with targeted muscle reinnervation should be performed to determine the optimal treatment option.

Making sense of phantom limb pain

Phantom limb pain (PLP) impacts the majority of individuals who undergo limb amputation. The PLP experience is highly heterogenous in its quality, intensity, frequency and severity. This heterogeneity, combined with the low prevalence of amputation in the general population, has made it difficult to accumulate reliable data on PLP. Consequently, we lack consensus on PLP mechanisms, as well as effective treatment options. However, the wealth of new PLP research, over the past decade, provides a unique opportunity to re-evaluate some of the core assumptions underlying what we know about PLP and the rationale behind PLP treatments. The goal of this review is to help generate consensus in the field on how best to research PLP, from phenomenology to treatment. We highlight conceptual and methodological challenges in studying PLP, which have hindered progress on the topic and spawned disagreement in the field, and offer potential solutions to overcome these challenges. Our hope is that a constructive evaluation of the foundational knowledge underlying PLP research practices will enable more informed decisions when testing the efficacy of existing interventions and will guide the development of the next generation of PLP treatments.

Peripheral Nerve Management in Extremity Amputations

The effective management of peripheral nerves in amputation surgery is critical to optimizing patient outcomes. Nerve-related pain after amputation is common, maybe a source of dissatisfaction and functional impairment, and should be considered in all amputees presenting with pain and dysfunction. While traction neurectomy or transposition has long been the standard of care, both regenerative peripheral nerve interface (RPNI) and targeted muscle reinnervation (TMR) have emerged as promising techniques to improve neuroma-related and phantom pain. A multi-disciplinary and multi-modal approach is essential for the optimal management of amputees both acutely and in the delayed or chronic setting.

Sleep disruption considerations for Paralympic athletes competing at Tokyo 2020

The role of sleep is now recognized as an important component for success in athletic performance, and sleep is proposed to be one of the most effective recovery strategies available. Insufficient sleep is commonly reported among athletes while several factors have been put forward to explain why elite athletes might experience poor sleep. However, Paralympic athletes may be predisposed to a greater risk of poor sleep due to the associated complexities of some impairment types. In fact, clinical research has previously shown that individuals with disabilities have a higher prevalence of sleep disturbances when compared to their able-bodied counterparts. However, research and evidence-based practices regarding the sleep of elite Paralympic athletes are limited. Firstly, this narrative review aims to identify challenges associated with the Paralympic games to obtain optimal sleep. Secondly, identify the specific risk factors to sleep associated with particular impairment groups within the Paralympic population, and lastly to propose potential sleep-enhancing strategies that might be of relevance for Paralympic athletes. From this review, initial observations have identified that Paralympic athletes may have a heightened risk of sleep-related problems, and importantly highlighted the current lack of understanding within this population group. Furthermore, this review identified where further research is warranted to better understand how specific impairments impact sleep and, consequently, athletic performance. Additionally, this review highlighted that the forthcoming Tokyo games may offer a unique challenge for athletes trying to obtain optimal sleep, due to the anticipated thermal demands and the consequent irregular scheduling of events.

Strategies for Gait Retraining in a Collegiate Runner with Transfemoral Amputation: A Case Report

BACKGROUND

More than fifty percent of people with limb amputations participate in sports or physical activity following amputation. Athletes with limb amputations may face additional challenges including phantom limb pain (PLP), psychological barriers, prosthetic complications, and gait abnormalities. Prevalence of PLP in the general amputee population is estimated to be as high as 85%. Despite the high prevalence of PLP, there is little research regarding the use of gait training as a treatment for PLP among both the general amputee population and athletes.

CASE DESCRIPTION

A 20-year old female collegiate track and field athlete presented with phantom knee pain brought on with running. The athlete demonstrated deficits in core and hip strength as well as decreased single leg stability bilaterally. Running gait analysis revealed circumduction with the prosthesis for limb advancement and increased vaulting with push off on the sound (uninvolved) limb. Gait retraining strategies were implemented to address video analysis findings and create a more efficient running gait and address phantom limb pain symptoms.

OUTCOMES

Rehabilitation and gait retraining strategies were effective in improving several clinical and functional outcomes in this case. Significant improvements were noted in PLP, running gait mechanics, and the patient's psychological and functional status as measured with a standardized outcome tool, the Patient-Reported Outcomes Measurement Information System® (PROMIS®).

DISCUSSION

Running gait training following amputation could be a crucial component of rehabilitation for athletes in an attempt to lessen pain while running, especially in those experiencing phantom limb pain (PLP). Utilization of a multidisciplinary team in the gait retraining process is recommended. There is a need for further research to determine the effects of running gait retraining for management of PLP in athletes with amputation.

LEVEL OF EVIDENCE

5.

Psychiatric understanding and treatment of patients with amputations

Amputation changes the lives of patients and their families. Consequently, the patient must adapt to altered body function and image. During this adaptation process, psychological problems, such as depression, anxiety, and posttraumatic stress disorder, can occur. The psychological difficulties of patients with amputation are often accepted as normal responses that are often poorly recognized by patients, family members, and their primary physicians. Psychological problems can interfere with rehabilitation and cause additional psychosocial problems. Therefore, their early detection and treatment are important. A multidisciplinary team approach, including mental health professionals, is ideal for comprehensive and biopsychosocial management. Mental health professionals could help patients set realistic goals and use adaptive coping styles. Psychiatric approaches should consider the physical, cognitive, psychological, social, and spiritual functions and social support systems before and after amputation. The abilities and limitations of physical, cognitive, psychological, and social functions should also be considered. To improve the patient’s adaptation, psychological interventions such as short-term psychotherapy, cognitive behavioral therapy, mindfulness meditation, biofeedback, and group psychotherapy can be helpful.

Residual limb pain: An evidence-based review

Acquired limb loss, whether from accident or amputation, occurs with an incidence of greater than 175,000 per year in the United States. Current prevalence is estimated at greater than 1.5 million and is expected to double within 30 years. While many patients with amputations may have no significant pain or sensory issues after healing from the initial loss, one-quarter to one-half of patients may have ongoing difficulties with residual limb pain, phantom limb pain, or phantom limb sensation. This review explores the potential etiologies of those symptoms, as well as a variety of treatment options that a practitioner may consider when approaching this condition.

Clinical updates on phantom limb pain

Phantom limb pain is highly prevalent after amputation. Treatment results will probably benefit from an interdisciplinary team and individually adapted surgical, prosthetic and pain medicine approaches.

Introduction:

Most patients with amputation (up to 80%) suffer from phantom limb pain postsurgery. These are often multimorbid patients who also have multiple risk factors for the development of chronic pain from a pain medicine perspective. Surgical removal of the body part and sectioning of peripheral nerves result in a lack of afferent feedback, followed by neuroplastic changes in the sensorimotor cortex. The experience of severe pain, peripheral, spinal, and cortical sensitization mechanisms, and changes in the body scheme contribute to chronic phantom limb pain. Psychosocial factors may also affect the course and the severity of the pain. Modern amputation medicine is an interdisciplinary responsibility.

Methods:

This review aims to provide an interdisciplinary overview of recent evidence-based and clinical knowledge.

Results:

The scientific evidence for best practice is weak and contrasted by various clinical reports describing the polypragmatic use of drugs and interventional techniques. Approaches to restore the body scheme and integration of sensorimotor input are of importance. Modern techniques, including apps and virtual reality, offer an exciting supplement to already established approaches based on mirror therapy. Targeted prosthesis care helps to obtain or restore limb function and at the same time plays an important role reshaping the body scheme.

Discussion:

Consequent prevention and treatment of severe postoperative pain and early integration of pharmacological and nonpharmacological interventions are required to reduce severe phantom limb pain. To obtain or restore body function, foresighted surgical planning and technique as well as an appropriate interdisciplinary management is needed.

Gabapentin for phantom limb pain after amputation in pediatric oncology: a systematic review protocol

BACKGROUND

Phantom limb pain (PLP) is a prevalent problem for children after amputation because of the chemotherapy treatment. Gabapentin is a potential option to manage PLP after amputation in pediatric oncology. However, no systematic review specifically investigated this topic. Thus, this study aims to appraise the efficacy and safety of gabapentin for post-amputation PLP in pediatric oncology.

METHODS

Electronic databases (Cochrane Library, MEDLINE, EMBASE, Web of Science, CINAHL, PsychINFO, Scopus, WANGFANG, and Chinese Biomedical Literature Database) will be systematically searched from the beginning to the present without limitations to publication status and language. Primary outcome is pain intensity. Secondary outcomes are analgesic drug consumption, sleep quality, depression, anxiety, health-related quality of life, and adverse events. The treatment effect of all dichotomous outcome data will be estimated as risk ratio and 95% confidence intervals (CIs) and that of continuous outcome data will be calculated as mean difference or standardized mean difference and 95% CIs. Methodological quality of randomized controlled trials (RCTs) will be assessed using Cochrane risk of bias tool and that of case-controlled studies (CCSs) will be appraised using Newcastle-Ottawa Tool. Statistical analysis will be conducted using RevMan 5.3 software.

DISCUSSION

This study will summarize up-to-date high-quality RCTs and CCSs to assess the efficacy and safety of gabapentin for PLP after amputation in pediatric oncology. The findings of this study will help to determine whether or not gabapentin is effective and safe for children with PLP after amputation.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202060090.

Effects of different anesthetic techniques on the incidence of phantom limb pain after limb amputation: a population-based retrospective cohort study

Background

General anesthesia (GA) has been considered the anesthetic technique which most frequent leads to phantom limb pain (PLP) after a limb amputation. However, these prior reports were limited by small sample sizes. The aims of this study were to evaluate the incidence of PLP according to the various anesthetic techniques used for limb amputation and also to compare the occurrence of PLP according to amputation etiology using the Korean Health Insurance Review and Assessment Service for large-scale demographic information.

Methods

The claims of patients who underwent limb amputation were reviewed by analyzing the codes used to classify standardized medical behaviors. The patients were categorized into three groups—GA, neuraxial anesthesia (NA), and peripheral nerve block (PNB)—in accordance with the anesthetic technique. The recorded diagnosis was confirmed using the diagnostic codes for PLP registered within one year after the limb amputation.

Results

Finally, 7,613 individuals were analyzed. According to the recorded diagnoses, 362 patients (4.8%) developed PLP after amputation. Among the 2,992 patients exposed to GA, 191 (6.4%) were diagnosed with PLP, whereas 121 (4.3%) of the 2,840 patients anesthetized with NA, and 50 (2.8%) of the 1,781 patients anesthetized under PNB developed PLP. The relative risks were 0.67 (95% confidence interval [CI], 0.53–0.84; P < 0.001) for NA and 0.43 (95% CI, 0.32–0.59; P < 0.001) for PNB.

Conclusions

In this retrospective cohort study, using large-scale population-based databases, the incidence rates of PLP after limb amputations were, in the order of frequency, GA, NA, and PNB.

The role of afferent input in postamputation pain: a randomized, double-blind, placebo-controlled crossover study

In this randomized, double-blind, placebo-controlled crossover study, we investigated whether a peripheral nerve block could temporarily eliminate phantom and stump pain after amputation. Amputees with constant postamputation pain were included and randomized to receive a nerve block with lidocaine 2% with adrenaline or saline in a crossover design. Spontaneous phantom and stump pain and evoked responses were assessed at baseline and at fixed time-points until 120 minutes after lidocaine or saline injection. The primary outcome was the difference in absolute change between worst pain intensity, either phantom or stump pain, at baseline and at 30 minutes after lidocaine or saline injection. Twelve amputees were randomized and 9 patients were included in the analysis. The absolute change in median worst pain intensity between lidocaine and saline injection was -2.0 (interquartile range, -4.0 to 0.0) (n = 9, P = 0.12). Nine of 9 patients reported at least some pain relief after lidocaine injection compared with only 2 of 9 patients after saline injection (P = 0.02). Phantom pain intensity was significantly reduced after lidocaine compared with saline injection (P = 0.04), whereas there was no significant change in stump pain intensity between the 2 interventions (P = 0.17). In all 9 amputees, evoked responses were eliminated after lidocaine injection. Thus, our findings suggest that afferent input from the peripheral nervous system plays an important role in postamputation pain.

Role of Potassium Ions Quantum Tunneling in the Pathophysiology of Phantom Limb Pain

(1) Background: multiple theories were proposed to explain the phenomenon of phantom limb pain (PLP). Nevertheless, the phenomenon is still shrouded in mystery. The aim of this study is to explore the phenomenon from a new perspective, where quantum tunneling of ions, a promising field in medical practice, might play a major role. (2) Methods: investigators designed a quantum mathematical model based on the Schrödinger equation to examine the probability of potassium ions quantum tunneling through closed membrane potassium channels to the inside of phantom axons, leading to the generation of action potential. (3) Results: the model suggests that the probability of action potential induction at a certain region of the membrane of phantom neurons, when a neuron of the stump area is stimulated over 1 mm² surface area of the membrane available for tunneling is 1.04 × 10⁻². Furthermore, upon considering two probabilities of potassium channelopathies, one that decreased the energy of the barrier by 25% and another one by 50%, the tunneling probability became 1.22 × 10⁻⁸ and 3.86 × 10⁻⁴, respectively. (4) Conclusion: quantum models of potassium ions can provide a reliable theoretical hypothesis to unveil part of the ambiguity behind PLP.

The current state of bionic limbs from the surgeon's viewpoint

Amputations have a devastating impact on patients' health with consequent psychological distress, economic loss, difficult reintegration into society, and often low embodiment of standard prosthetic replacement.The main characteristic of bionic limbs is that they establish an interface between the biological residuum and an electronic device, providing not only motor control of prosthesis but also sensitive feedback.Bionic limbs can be classified into three main groups, according to the type of the tissue interfaced: nerve-transferred muscle interfacing (targeted muscular reinnervation), direct muscle interfacing and direct nerve interfacing.Targeted muscular reinnervation (TMR) involves the transfer of the remaining nerves of the amputated stump to the available muscles.With direct muscle interfacing, direct intramuscular implants record muscular contractions which are then wirelessly captured through a coil integrated in the socket to actuate prosthesis movement.The third group is the direct interfacing of the residual nerves using implantable electrodes that enable reception of electric signals from the prosthetic sensors. This can improve sensation in the phantom limb.The surgical procedure for electrode implantation consists of targeting the proximal nerve area, competently introducing, placing, and fixing the electrodes and cables, while retaining movement of the arm/leg and nerve, and avoiding excessive neural damage.Advantages of bionic limbs are: the improvement of sensation, improved reintegration/embodiment of the artificial limb, and better controllability. Cite this article: EFORT Open Rev 2020;5:65-72. DOI: 10.1302/2058-5241.5.180038.

Electro-cutaneous stimulation on the palm elicits referred sensations on intact but not on amputated digits

OBJECTIVE

Grasping and manipulation control critically depends on tactile feedback. Without this feedback, the ability for fine control of a prosthesis is limited in upper limb amputees. Early studies have shown that non-invasive electro-cutaneous stimulation (ES) can induce referred sensations that are spread to a wider and/or more distant area, with respect to the electrodes. Building on this, we sought to exploit this effect to provide somatotopically matched sensory feedback to people with partial hand (digital) amputations.

APPROACH

For the first time, this work investigated the possibility of inducing referred sensations in the digits by activating the palmar nerves. Specifically, we electrically stimulated 18 sites on the palm of non-amputees to evaluate the effects of sites and stimulation parameters on modality, magnitude, and location of the evoked sensations. We performed similar tests with partial hand amputees by testing those sites that had most consistently elicited referred sensations in non-amputees.

MAIN RESULTS

We demonstrated referred sensations in non-amputees from all stimulation sites in one form or another. Specifically, the stimulation of 16 of the 18 sites gave rise to reliable referred sensations. Amputees experienced referred sensations to unimpaired digits, just like non-amputees, but we were unable to evoke referred sensations in their missing digits: none of them reported sensations that extended beyond the tip of the stump.

SIGNIFICANCE

The possibility of eliciting referred sensations on the digits may be exploited in haptic systems for providing touch sensations without obstructing the fingertips or their movements. The study also suggests that the phenomenon of referred sensations through ES may not be exploited for partial hand prostheses, and it invites researchers to explore alternative approaches. Finally, the results seem to confirm previous studies suggesting that the stumps in partial hand amputees partially acquire the role of the missing fingertips, physiologically and cognitively.

Joint power distribution does not change within the contralateral limb one year after unilateral limb loss

BACKGROUND

To assist with forward progression during gait, persons with unilateral lower-limb amputation typically perform more work within the unaffected versus affected limb. However, prior cross-sectional (>2years post-amputation) studies cannot necessarily elucidate the origin or evolution of these compensatory mechanics.

RESEARCH QUESTION

Do lower limb joint kinetics change during the initial stages of independent ambulation among persons with lower-limb amputation?

METHODS

Nine males with unilateral lower-limb amputation (6 transtibial; 3 transfemoral) completed instrumented gait analyses (speed = 1.2 m/s) at 2 and 12-months post-independent ambulation. Within the unaffected limb, sagittal and frontal plane total positive and negative work, peak power, average positive power, and percent contribution of each joint were compared between time points using paired t-tests.

RESULTS

No differences existed between time points in total positive or negative work, at any joint (p > 0.038) in either plane. Similarly, there were no differences in percent contribution by each joint to total average power by sagittal (p > 0.15) or frontal (p > 0.32) planes.

SIGNIFICANCE

Persons with unilateral lower-limb amputation do not alter power distribution among joints within the unaffected limb during initial independent ambulation. However, compared to previous cross-sectional reports, smaller peak powers in the unaffected hip and knee here suggest mechanical work increases with time since amputation. Future research should longitudinally monitor segment mechanics to determine when deleterious strategies develop, as these have implications for joint degeneration and pain.

The Effect of Once-Daily Gabapentin Extended Release Formulation in Patients With Postamputation Pain

Objectives

To compare gabapentin extended-release, a gastro-retentive formulation, in relieving postamputation pain among gabapentin-experienced and gabapentin-naïve patients.

Design

Open-labeled pilot study.

Subjects

Sixteen patients with postamputation pain (8 patients in the gabapentin-experienced and 8 patients in the gabapentin-naïve groups).

Methods

Patients were started on gabapentin extended-release and were followed up for 8 weeks. Patients reported their pain severity during rest and movement using a numeric rating scale (NRS), interference of pain with daily activities using the modified brief pain inventory (MBPI) questionnaire, and treatment satisfaction using the treatment satisfaction questionnaire for medication (TSQM).

Results

Patients from both gabapentin-experienced and gabapentin-naïve groups achieved a significant and sustainable pain relief over the course of therapy. The pain scores at rest decreased in both gabapentin-experienced and gabapentin-naïve groups from 5.88 ± 1.36 and 4.88 ± 2.95 to 1.88 ± 0.99 and 1.38 ± 1.51, respectively. An average percent of pain relief with gabapentin extended-release was noted to be significant (p < 0.01) after 8 weeks of therapy among gabapentin-experienced (81.25 ± 16.42%) and gabapentin-naïve groups (85 ± 17.73%) when compared to baseline for gabapentin-experienced (31.25 ± 29%) and gabapentin-naïve groups (36.25 ± 34.2%), respectively. Gabapentin-experienced and gabapentin-naïve groups had no significant difference in global satisfaction from treatment (79.14 ± 10.47 and 83.3 ± 20.82), convenience of treatment (73.78 ± 19.04 and 90.44 ± 11.66), effectiveness of treatment (72.6 ± 10.1 and 79.73 ± 11.6). The only statistically significant difference among gabapentin-experienced and gabapentin-naïve groups was found in adverse event tolerability (65.78 ± 10.36 and 85.8 ± 10.14, p < 0.01).

Conclusion

Once-daily dosing of gabapentin-extended release showed significant improvement in pain severity and functional status, with no difference found between gabapentin-experienced versus gabapentin-naïve patients.

Coping with Phantom Limb Pain

Phantom limb pain is a chronic neuropathic pain that develops in 45-85% of patients who undergo major amputations of the upper and lower extremities and appears predominantly during two time frames following an amputation: the first month and later about 1 year. Although in most patients the frequency and intensity of pain diminish over time, severe pain persists in about 5-10%. It has been proposed that factors in both the peripheral and central nervous systems play major roles in triggering the development and maintenance of pain associated with extremity amputations. Chronic pain is physically and mentally debilitating, affecting an individual's capacity for self-care, but also diminishing an individual's daily capacity for personal and economic independence. In addition, the pain may lead to depression and feelings of hopelessness. A National Center for Biotechnology Information study found that in the USA alone, the annual cost of dealing with neuropathic pain is more than $600 billion, with an estimated 20 million people in the USA suffering from this condition. Although the pain can be reduced by antiepileptic drugs and analgesics, they are frequently ineffective or their side effects preclude their use. The optimal approach for eliminating neuropathic pain and improving individuals' quality of life is the development of novel techniques that permanently prevent the development and maintenance of neuropathic pain, or that eliminate the pain once it has developed. What is still required is understanding when and where an effective novel technique must be applied, such as onto the nerve stump of the transected peripheral axons, dorsal root ganglion neurons, spinal cord, or cortex to induce the desired influences. This review, the second of two in this journal volume, examines the techniques that may be capable of reducing or eliminating chronic neuropathic pain once it has developed. Such an understanding will improve amputees' quality of life by blocking the mechanisms that trigger and/or maintain PLP and chronic neuropathic pain.

Motor cortex stimulation: a systematic literature-based analysis of effectiveness and case series experience

Background

Aim to quantitatively analyze the clinical effectiveness for motor cortex stimulation (MCS) to refractory pain.

Methods

The literatures were systematically searched in database of Cocharane library, Embase and PubMed, using relevant strategies. Data were extracted from eligible articles and pooled as mean with standard deviation (SD). Comparative analysis was measured by non-parametric t test and linear regression model.

Results

The pooled effect estimate from 12 trials (n = 198) elucidated that MCS shown the positive effect on refractory pain, and the total percentage improvement was 35.2% in post-stroke pain and 46.5% in trigeminal neuropathic pain. There is no statistical differences between stroke involved thalamus or non-thalamus. The improvement of plexus avulsion (29.8%) and phantom pain (34.1%) was similar. The highest improvement rate was seen in post-radicular plexopathy (65.1%) and MCS may aggravate the pain induced by spinal cord injury, confirmed by small sample size. Concurrently, Both the duration of disease (r = 0.233, p = 0.019*) and the time of follow-up (r = 0.196, p = 0.016*) had small predicative value, while age (p = 0.125) had no correlation to post-operative pain relief.

Conclusions

MCS is conducive to the patients with refractory pain. The duration of disease and the time of follow-up can be regarded as predictive factor. Meanwhile, further studies are needed to reveal the mechanism of MCS and to reevaluate the cost-benefit aspect with better-designed clinical trials.

Electronic supplementary material

The online version of this article (10.1186/s12883-019-1273-y) contains supplementary material, which is available to authorized users.

Mechanical/thermal sensitivity and superficial temperature in the stump of long-term tail-docked dairy cows

Background

Tail docking of dairy cows is a painful procedure that affects animal welfare level. The aims of this study were first to evaluate the response to mechanical and thermal stimulation, and second to determine the superficial temperature of the stump of tail-docked dairy cows.

Methods

One hundred and sixty-four dairy cows were enrolled. From these, 133 cows were assigned to the tail-docked (TD) group and 31 cows were selected as control animals. The following sensory assessments to evaluate pain in tail-docked cows were performed. Sensitivity of the tail region in both groups of animals was evaluated using a portable algometer. Cold and heat sensitivity assessment was performed using a frozen pack (0 °C) and warm water (45 °C), respectively. Pinprick sensitivity was evaluated using a Wartenberg neurological pinwheel. Superficial temperature was evaluated using a thermographic camera. All sensory assessments and superficial temperature were evaluated in the ventral surface of the tail stump (TD) and tail (C).

Results

Pressure pain threshold was lower in TD cows (5.97 ± 0.19 kg) compared to control cows (11.75 ± 0.43 kg). Heat and cold sensitivity was higher in the TD cows compared to control cows with 29% and 23% of TD cows responding positively, respectively. Similarly, after pinprick sensitivity test was performed, 93% of TD cows elicited a positive response to stimulation. Tail-docked cows had lower superficial temperature (26.4 ± 0.27 °C) compared to control cows (29.9 ± 0.62 °C).

Discussion

Pressure pain threshold values in both groups of animals were higher than those previously reported for TD pigs, sows and cows. In contrast, pinprick stimulation evaluates the presence of punctate mechanical hyperalgesia/allodynia, usually related to traumatic nerve injury, and this association may reveal that it is possible that these animals developed a disorder associated to the development of a tail stump neuroma and concurrent neuropathic pain, previously reported in TD lambs, pigs and dogs. Thermal sensitivity showed that TD cows responded positively to heat and cold stimulation. These findings suggest that long-term TD cows could be suffering hyperalgesia/allodynia, which may be indicative of chronic pain. Lower superficial temperature in the stump may be associated to sympathetic fiber sprouting in the distal stump, which can lead to vasoconstriction and lower surface temperatures. Further studies are needed in order to confirm neuroma development and adrenergic sprouting.

[Psychotherapies for the Treatment of Phantom Limb Pain]

INTRODUCTION

The phantom limb pain has been described as a condition in which patients experience a feeling of itching, spasm or pain in a limb or body part that has been previously amputated. Such pain can be induced by a conflict between the representation of the visual and proprioceptive feedback of the previously healthy limb. The phantom limb pain occurs in at least 42 to 90% of amputees. Regular drug treatment of phantom limb pain is almost never effective.

METHODS

A systematic review of the literature was conducted in Medline and Cochrane using the MESH terms "phantom limb pain" and "psychotherapy", published in the last 10 years, in English and Spanish, finding 49 items. After reviewing the abstracts, 25 articles were excluded for not being related to the objective of the research. Additionally cross references of included articles and literature were reviewed.

OBJECTIVES

To describe the psychotherapies used in the management of phantom limb pain, their effectiveness and clinical application reported in the literature.

AIMS

The mechanisms underlying phantom limb pain were initially explained, as were the published studies on the usefulness of some psychotherapies such as mirror visual feedback and immersive virtual reality, visual imagery, desensitization and reprocessing eye movements and hypnosis.

CONCLUSIONS

The phantom limb pain is a complex syndrome that requires pharmacological and psychotherapeutic intervention. The psychotherapies that have been used the most as adjuvants in the treatment of phantom limb pain are mirror visual feedback, desensitization and reprocessing eye movements, imagery and hypnosis. Studies with more representative samples, specifically randomized trials are required.

Capsaicin 8% patch treatment for amputation stump and phantom limb pain: a clinical and functional MRI study

Purpose

The aim of this study was to measure the efficacy of a single 60 min application of capsaicin 8% patch in reducing chronic amputation stump and phantom limb pain, associated hypersensitivity with quantitative sensory testing, and changes in brain cortical maps using functional MRI (fMRI) scans.

Methods

A capsaicin 8% patch (Qutenza) treatment study was conducted on 14 patients with single limb amputation, who reported pain intensity on the Numerical Pain Rating Scale ≥4/10 for chronic stump or phantom limb pain. Pain assessments, quantitative sensory testing, and fMRI (for the lip pursing task) were performed at baseline and 4 weeks after application of capsaicin 8% patch to the amputation stump. The shift into the hand representation area of the cerebral cortex with the lip pursing task has been correlated with phantom limb pain intensity in previous studies, and was the fMRI clinical model for cortical plasticity used in this study.

Results

The mean reduction in spontaneous amputation stump pain, phantom limb pain, and evoked stump pain were −1.007 (p=0.028), −1.414 (p=0.018), and −2.029 (p=0.007), respectively. The areas of brush allodynia and pinprick hypersensitivity in the amputation stump showed marked decreases: −165 cm², −80% (p=0.001) and −132 cm², −72% (p=0.001), respectively. fMRI analyses provided objective evidence of the restoration of the brain map, that is, reversal of the shift into the hand representation of the cerebral cortex with the lip pursing task (p<0.05).

Conclusion

The results show that capsaicin 8% patch treatment leads to significant reduction in chronic pain and, particularly, in the area of stump hypersensitivity, which may enable patients to wear prostheses, thereby improving mobility and rehabilitation. Phantom limb pain (“central” pain) and associated brain plasticity may be modulated by peripheral inputs, as they can be ameliorated by the peripherally restricted effect of the capsaicin 8% patch.

Characterization of short- and long-term mechanical sensitisation following surgical tail amputation in pigs

Commercial pigs are frequently exposed to tail mutilations in the form of preventive husbandry procedures (tail docking) or as a result of abnormal behaviour (tail biting). Although tissue and nerve injuries are well-described causes of pain hypersensitivity in humans and in rodent animal models, there is no information on the changes in local pain sensitivity induced by tail injuries in pigs. To determine the temporal profile of sensitisation, pigs were exposed to surgical tail resections and mechanical nociceptive thresholds (MNT) were measured in the acute (one week post-operatively) and in the long-term (either eight or sixteen weeks post-surgery) phase of recovery. The influence of the degree of amputation on MNTs was also evaluated by comparing three different tail-resection treatments (intact, ‘short tail’, ‘long tail’). A significant reduction in MNTs one week following surgery suggests the occurrence of acute sensitisation. Long-term hypersensitivity was also observed in tail-resected pigs at either two or four months following surgery. Tail amputation in pigs appears to evoke acute and sustained changes in peripheral mechanical sensitivity, which resemble features of neuropathic pain reported in humans and other species and provides new information on implications for the welfare of animals subjected to this type of injury.

Trajectory of phantom limb pain relief using mirror therapy: Retrospective analysis of two studies

Background and purpose

Research indicates that mirror therapy reduces phantom limb pain (PLP). Objectives were to determine when mirror therapy works in those who respond to treatment, the relevance of baseline PLP to when pain relief occurs, and what pain symptoms respond to mirror therapy.

Methods

Data from two independent cohorts with unilateral lower limb amputation were analyzed for this study (n = 33). Mirror therapy consisted of 15-min sessions in which amputees performed synchronous movements of the phantom and intact legs/feet. PLP was measured using a visual analogue scale and the Short-Form McGill Pain Questionnaire.

Results

The severity of PLP at the beginning of treatment predicted when pain relief occurred. Those with low baseline PLP experienced a reduction (p < 0.05) in PLP by session 7 of treatment, those with medium baseline PLP experienced pain relief by session 14 of treatment, and those with high baseline PLP experienced pain relief by session 21 of treatment. Mirror therapy reduced throbbing, shooting, stabbing, sharp, cramping, aching, tender, splitting, tiring/exhausting, and punishing-cruel pain symptoms.

Conclusion

The degree of PLP at baseline predicts when mirror therapy relieves pain.

Implications

This article indicates that the degree of baseline PLP affects when mirror therapy relieves pain: relief occurs by session 7 in patients with low PLP but by session 21 in patients with high PLP. Clinicians should anticipate slower pain relief in patients who begin treatment with high levels of pain.

Selective Radiofrequency Stimulation of the Dorsal Root Ganglion (DRG) as a Method for Predicting Targets for Neuromodulation in Patients With Post Amputation Pain: A Case Series

OBJECTIVE

While spinal cord stimulation (SCS) has established itself as an accepted and validated treatment for neuropathic pain, there are a number of conditions where it has experienced less, long-term success: post amputee pain (PAP) being one of them. Dorsal root ganglion (DRG) stimulation has shown great promise, particularly in conditions where traditional SCS has fallen short. One major difference between DRG stimulation and traditional SCS is the ability to provide focal stimulation over targeted areas. While this may be a contributing factor to its superiority, it can also be a limitation insofar stimulating the wrong DRG(s) can lead to failure. This is particularly relevant in conditions like PAP where neuroplastic maladaptation occurs causing the pain to deviate from expected patterns, thus creating uncertainty and variability in predicting targets for stimulation. We propose selective radiofrequency (RF) stimulation of the DRG as a method for preoperatively predicting targets for neuromodulation in patients with PAP.

METHODS

We present four patients with PAP of the lower extremities. RF stimulation was used to selectively stimulate individual DRG's, creating areas of paresthesias to see which most closely correlated/overlapped with the painful area(s). RF stimulation to the DRG's that resulted in the desirable paresthesia coverage in the residual or the missing limb(s) was recorded as "positive." Trial DRG leads were placed based on the positive RF stimulation findings.

RESULTS

In each patient, stimulating one or more DRG(s) produced paresthesias patterns that were contradictory to know dermatomal patterns. Upon completion of a one-week trial all four patients reported 60-90% pain relief, with coverage over the painful areas, and opted for permanent implant.

CONCLUSIONS

Mapping the DRG via RF stimulation appears to provide improved accuracy for determining lead placement in the setting of PAP where pain patterns are known to deviate from conventional dermatomal mapping.

Association between phantom limb complex and the level of amputation in lower limb amputee

Objective

The aim of this study was to evaluate the natural course of phantom limb complex without any treatment after lower limb amputation.

Methods

The study design was consisted of a combination of retrospective review and cross-sectional interview. 101 patients with lower limb amputation were included into the study. Patients were divided into three groups according to the amputation level: i) from hip disarticulation to knee disarticulation (including knee disarticulation) (25 patients, mean age: 55.9, 19 males, 6 females) ii) transtibial amputation (below knee to ankle including ankle disarticulation) (41 patients, mean age: 58.6, 33 males, 8 females) iii) below ankle to toe amputation (35 patients, mean age: 58.7, 26 males, 9 females). The patients were evaluated on both early postoperative period (EPP) and sixth months after the surgery (ASM). The data related amputation including amputation date, level, cause, stump pain (SP), phantom limb pain (PLP), components of PLP, phantom sensation (PS) were recorded based on the information obtained from patients' and hospital files.

Results

Statistically significant differences were found for pain intensity (VAS) between groups for SP and PLP at EPP (p < 0.001, p = 0.036; respectively). The mean VAS score in Group I for SP and PLP was higher than other groups. This differences for SP and PLP did not continue at ASM assessment (p = 0.242, p = 0.580; respectively).

Conclusion

VAS scores for SP in above knee amputations and VAS scores for PLP in above knee amputations and below ankle amputations were higher at EPP. But these high scores had disappeared over time. Management strategies have to be considered particularly in the early postoperative period in patients who had undergone above knee amputation.

Level of Evidence

Level III Prognostic study.

Prevalence of Phantom Limb Pain, Stump Pain, and Phantom Limb Sensation among the Amputated Cancer Patients in India: A Prospective, Observational Study

INTRODUCTION

The phantom limb pain (PLP) and phantom limb sensation (PLS) are very common among amputated cancer patients, and they lead to considerable morbidity. In spite of this, there is a lack of epidemiological data of this phenomenon among the Asian population. This study was done to provide the data from Indian population.

METHODS

The prevalence of PLP, stump pain (SP), and PLS was prospectively analyzed from the amputated cancer patients over a period of 2 years in Dr. B.R.A. Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, New Delhi. The risk factors and the impact of phantom phenomenon on patients were also noted.

RESULTS

The prevalence of PLP was 41% at 3 and 12 months and 45.3% at 6 months, whereas that of SP and PLS was 14.4% and 71.2% at 3 months, 18.75% and 37.1% at 6 months, 15.8% and 32.4% at 12 months, respectively. There was higher prevalence of PLP and PLS among the patients with history of preamputation pain, smoking with proximal level of amputation, receiving general anesthesia, receiving intravenous (IV) opioid postoperative analgesia, and developing neuroma or infection.

CONCLUSION

The prevalence of PLP and PLS was higher among the cancer amputees as compared to SP, and a few risk factors responsible for their higher prevalence were found in our study. The PLP and PLS lead to considerable morbidity in terms of sleep disturbance and depression.

Regenerative peripheral neuropathic pain: novel pathological pain, new therapeutic dimension

After peripheral nerve damage, injured or stressed primary sensory neurons (PSNs) transmitting pathological pain (pathopain) sensitize central nervous system (CNS) neural circuits and determine behavioral phenotypes of peripheral neuropathic pain (PNP). Therefore, phenotypic profiling of pathopain-transmitting PSNs is vital for probing and discovering PNP conditions. Following peripheral nerve injuries (PNIs), PNP might be potentially transmitted by distinct classes of damaged or stressed PSNs, such as axotomized PSNs without regeneration (axotomy-non-regenerative neurons), axotomized PSNs with accurate regeneration (axotomy-regenerative neurons), and spared intact PSNs adjacent to axotomized neurons (axotomy-spared neurons). Both axotomy-non-regenerative neurons and axotomy-spared neurons have been definitely shown to participate in specific PNP transmission. However, whether axotomy-regenerative neurons could transmit PNP with unique features has remained unclear. Recent studies in rodent models of axonotmesis have clearly demonstrated that axotomy-regenerative neurons alone transmit persistent pathological pain with unique behavioral phenotypes. In this review, we exclusively review this novel category of PNP, reasonably term it ‘regenerative peripheral neuropathic pain’, and finally discuss its potential clinical significance as a new therapeutic dimension for PNIs beyond nerve regeneration.

Percutaneous Image-Guided Cryoablation for the Treatment of Phantom Limb Pain in Amputees: A Pilot Study

PURPOSE

To prospectively evaluate percutaneous image-guided nerve cryoablation for treatment of refractory phantom limb pain (PLP) in a pilot cohort for purposes of deriving parameters to design a larger, randomized, parallel-armed, controlled trial.

MATERIALS AND METHODS

From January 2015 to January 2016, 21 patients with refractory PLP underwent image-guided percutaneous cryoneurolysis procedures. Visual analog scale scores were documented at baseline and 7, 45, and 180 days after the procedure. Responses to a modified Roland Morris Disability Questionnaire were documented at baseline and 7 and 45 days after the procedure.

RESULTS

Technical success rate of the procedures was 100%. There were 6 (29%) minor procedure-related complications. Disability scores decreased from a baseline mean of 11.3 to 3.3 at 45-day follow-up (95% confidence interval 5.8, 10.3; P < .0001). Pain intensity scores decreased from a baseline mean of 6.2 to 2.0 at long-term follow-up (95% confidence interval 2.8, 5.6; P < .0001).

CONCLUSIONS

Image-guided percutaneous nerve cryoablation is feasible and safe and may represent a new efficacious therapeutic option for patients with phantom pains related to limb loss.

Where is hidden the ghost in phantom sensations?

The term phantom sensations (PS) refers to sensations in a missing body part. They are almost universal in amputees and can be both painful and not painful. Although PS have been frequently described in limb amputees, they can also occur in other clinical conditions and several pathophysiological interpretations have been proposed, with a predominance of theories based on a central origin. Actually, different mechanisms are able to create a phantom sensation. After an amputation, PS are frequently generated by the genesis of ectopic action potentials in the interrupted nerve fibers but the PS generator can also be more proximal. Sometimes PS are not created by the stimulation of somatosensory fibers with a missing territory, but they can be the result of central sensitization or neuroplastic changes that allow for the convergence of impulses coming from different body parts (referred sensations), one of which is missing. In conclusion, PS can be generated by both neuropathic and non-neuropathic mechanisms developed in the amputated body part or in other parts of the nervous system. Since these mechanisms are not pathognomonic of amputation there are no hidden ghosts to look for in phantom sensations. The only interpretative rule is just to follow the pathophysiological principles.

Perceptions of phantom limb pain in lower limb amputees and its effect on quality of life: a qualitative study

BACKGROUND

Phantom limb pain (PLP) is a prevalent complication post-amputation. Currently, qualitative literature exploring the experience of PLP in amputees is sparse, and little is known about whether the educational needs of amputees are being met.

OBJECTIVES

To explore lower limb amputees' descriptive lived experiences of PLP, to understand how PLP affects quality of life and to determine whether amputees feel they are provided with adequate information about PLP.

METHODS

A qualitative descriptive approach, situated under the constructivist paradigm was taken, consisting of cross-sectional semi-structured interviews. A purposive sample of 15 lower limb amputees, 1-3 months post-surgery with past or current experience of PLP were interviewed once about their experience of PLP. Interviews were audio-recorded, transcribed verbatim and analysed using Framework Analysis. Interviews were conducted while participants were inpatients at an amputee rehabilitation unit in London.

RESULTS

Six key themes were identified during analysis, of which three were related to PLP and are reported on in this article (real and physical phantoms, living with a phantom and being informed). PLP had numerous painful qualities. The phantom felt real, with kinetic and kinaesthetic properties. PLP had multiple meanings to amputees, was considered a reminder of circumstances and could affect quality of life. Information provided about PLP was inadequate.

CONCLUSION

PLP can be a severe and annoying experience acting as a reminder of amputees' circumstances. Information provided about PLP is inadequate, with some amputees still perceiving PLP as mental and imaginary. Education about PLP and awareness and accessibility to non-pharmacological interventions needs to be improved.

Post-amputation pain is associated with the recall of an impaired body representation in dreams-results from a nation-wide survey on limb amputees

The experience of post-amputation pain such as phantom limb pain (PLP) and residual limb pain (RLP), is a common consequence of limb amputation, and its presence has negative effects on a person's well-being. The continuity hypothesis of dreams suggests that the presence of such aversive experiences in the waking state should be reflected in dream content, with the recalled body representation reflecting a cognitive proxy of negative impact. In the present study, we epidemiologically assessed the presence of post-amputation pain and other amputation-related information as well as recalled body representation in dreams in a sample of 3,234 unilateral limb amputees. Data on the site and time of amputation, residual limb length, prosthesis use, lifetime prevalence of mental disorders, presence of post-amputation pain, and presence of non-painful phantom phenomena were included in logistic regression analyses using recalled body representation in dreams (impaired, intact, no memory) as dependent variable. The effects of age, sex, and frequency of dream recall were controlled for. About 22% of the subjects indicated that they were not able to remember their body representation in dreams, another 24% of the amputees recalled themselves as always intact, and only a minority of less than 3% recalled themselves as always impaired. Almost 35% of the amputees dreamed of themselves in a mixed fashion. We found that lower-limb amputation as well as the presence of PLP and RLP was positively associated with the recall of an impaired body representation in dreams. The presence of non-painful phantom phenomena, however, had no influence. These results complement previous findings and indicate complex interactions of physical body appearance and mental body representation, probably modulated by distress in the waking state. The findings are discussed against the background of alterations in cognitive processes after amputation and hypotheses suggesting an innate body model.

Phantom pain in a patient with brachial plexus avulsion injury

OBJECTIVE

Phantom limb pain is a painful sensation perceived in the absent limb following surgical or traumatic amputation. Phantom limb sensations, which are nonpainful, occur in nearly all amputees. Deafferentation can also produce similar symptoms. Here we report the presence of phantom pain in a deafferented limb.

DESIGN

Case report.

SETTING

Hospital-based outpatient clinic.

PATIENT

A 65-year-old man was referred to the pain clinic for management of upper extremity pain secondary to brachial plexus avulsion (BPA) following a motor vehicle accident. Initially he noticed a feeling of growing and shrinking of his arm. Following this, the pain started gradually from his elbow extending to his fingertips covering all dermatomes. He described the pain as continuous, severe, and sharp. He also described the arm as being separate from his existing insensate arm and felt as though the fist was closed with the thumb pointing out. On physical examination, he had no sensation to fine touch or pressure below the elbow. There were no consistent areas of allodynia. He had diffuse muscle wasting in all the muscle groups of his left upper extremity, besides winging of the scapula. Electrodiagnostic studies showed a left brachial plexopathy consistent with multilevel nerve root avulsion sparing the dorsal rami.

CONCLUSION

This is a report of phantom limb sensations and phantom pain following BPA in an intact but flaccid and insensate limb.

Psychological aspects of hand transplantation

PURPOSE OF REVIEW

Psychosocial aspects are important indicators for reconstructive hand transplantation (RHT). They warrant further research attention given the influence of psychosocial factors on the success of RHT. This review will contrast RHT with solid organ transplantation, provide information to guide selection of RHT candidates and ethical implications, share information on psychological outcomes, and address the importance of a multicenter research approach.

RECENT FINDINGS

Previously published RHT reports have tried to identify psychosocial factors that are essential to guide selection of RHT candidates and that predict psychosocial outcomes. These issues in RHT are receiving increased attention, but standardized psychosocial evaluation and follow-up protocols are still needed. Recent study highlights the potential for a multicenter research approach that uses standardized assessment strategies and also emphasizes the need for a shared assessment approach to understand psychosocial outcomes.

SUMMARY

RHT combines the technical rigors of hand surgery and microsurgery with the complex multidisciplinary care that defines modern transplantation medicine. As recent work has provided a more complete picture of the complexities of the psychosocial factors in RHT, a psychosocial assessment protocol developed with input across the centers currently performing this procedure would capitalize on the collective diverse clinical experiences and standardize the assessment and follow-up protocol. With such standardized procedures in place, psychosocial risk factors for both poor psychosocial and medical/surgical outcomes can be identified which can inform the selection or preparation of future candidates.

Prevalence of acute neuropathic pain after cancer surgery: A prospective study

Background and Aims:

Acute neuropathic pain (ANP) is an under-recognised and under-diagnosed condition and often difficult to treat. If left untreated, it may further transform into persistent post-operative chronic pain leading to a disability.

Aims:

This prospective study was undertaken on 300 patients to identify the prevalence of ANP in the post-operative period by using a neuropathic pain detection questionnaire tool.

Methods:

This is an open-label study in which patients with six different types of cancer surgeries (Thoracic, gastro-intestinal, gynae/urology, bone/soft-tissue, head and neck and breast subgroups-50 each) were included for painDETECT questionnaire tool on the 2^nd and 7^th day surgery.

Results:

This study found a 10% point prevalence of ANP. Analysis showed that 25 patients had ‘possible’ ANP, the maximum from urological cancer surgery (6) followed by thoracic surgery (5). Five patients were found to have ‘positive’ ANP including 2 groin node dissection, 2 hemipelvectomy and 1 oesophagectomy.

Conclusion:

Significant relationship between severity of post-operative pain was found with the occurrence of ANP in the post-operative period requiring a special attention to neuropathic pain assessment. Larger studies are required with longer follow-up to identify accurately the true prevalence and causative factors of ANP after surgery.

An overview of psychosocial assessment procedures in reconstructive hand transplantation

There have been more than 90 hand and upper extremity transplants performed worldwide. Functional and sensory outcomes have been reported in several studies, but little is known about the psychosocial outcomes. A comprehensive systematic literature review was performed, addressing the psychosocial impact of reconstructive hand transplantation. This review provides an overview of psychosocial evaluation protocols and identifies standards in this novel and exciting field. Essentials of the psychosocial assessment are discussed and a new protocol, the 'Chauvet Protocol', representing a standardized assessment protocol for future multicenter psychosocial trials is being introduced.

Postamputation pain: epidemiology, mechanisms, and treatment

Postamputation pain (PAP) is highly prevalent after limb amputation but remains an extremely challenging pain condition to treat. A large part of its intractability stems from the myriad pathophysiological mechanisms. A state-of-art understanding of the pathophysiologic basis underlying postamputation phenomena can be broadly categorized in terms of supraspinal, spinal, and peripheral mechanisms. Supraspinal mechanisms involve somatosensory cortical reorganization of the area representing the deafferentated limb and are predominant in phantom limb pain and phantom sensations. Spinal reorganization in the dorsal horn occurs after deafferentataion from a peripheral nerve injury. Peripherally, axonal nerve damage initiates inflammation, regenerative sprouting, and increased "ectopic" afferent input which is thought by many to be the predominant mechanism involved in residual limb pain or neuroma pain, but may also contribute to phantom phenomena. To optimize treatment outcomes, therapy should be individually tailored and mechanism based. Treatment modalities include injection therapy, pharmacotherapy, complementary and alternative therapy, surgical therapy, and interventions aimed at prevention. Unfortunately, there is a lack of high quality clinical trials to support most of these treatments. Most of the randomized controlled trials in PAP have evaluated medications, with a trend for short-term Efficacy noted for ketamine and opioids. Evidence for peripheral injection therapy with botulinum toxin and pulsed radiofrequency for residual limb pain is limited to very small trials and case series. Mirror therapy is a safe and cost-effective alternative treatment modality for PAP. Neuromodulation using implanted motor cortex stimulation has shown a trend toward effectiveness for refractory phantom limb pain, though the evidence is largely anecdotal. Studies that aim to prevent PA P using epidural and perineural catheters have yielded inconsistent results, though there may be some benefit for epidural prevention when the infusions are started more than 24 hours preoperatively and compared with nonoptimized alternatives. Further investigation into the mechanisms responsible for and the factors associated with the development of PAP is needed to provide an evidence-based foundation to guide current and future treatment approaches.

The role of the environment in eliciting phantom-like sensations in non-amputees

Following the amputation of a limb, many amputees report that they can still vividly perceive its presence despite conscious knowledge that it is not physically there. However, our ability to probe the mental representation of this experience is limited by the intractable and often distressing pain associated with amputation. Here, we present a method for eliciting phantom-like experiences in non-amputees using a variation of the rubber hand illusion in which a finger has been removed from the rubber hand. An interpretative phenomenological analysis revealed that the structure of this experience shares a wide range of sensory attributes with subjective reports of phantom limb experience. For example, when the space where the ring finger should have been on the rubber hand was stroked, 93% of participants (i.e., 28/30) reported the vivid presence of a finger that they could not see and a total of 57% (16/28) of participants who felt that the finger was present reported one or more additional sensory qualities such as tingling or numbness (25%; 7/28) and alteration in the perceived size of the finger (50%; 14/28). These experiences indicate the adaptability of body experience and share some characteristics of the way that phantom limbs are described. Participants attributed changes to the shape and size of their "missing" finger to the way in which the experimenter mimed stroking in the area occupied by the missing finger. This alteration of body perception is similar to the phenomenon of telescoping experienced by people with phantom limbs and suggests that our sense of embodiment not only depends on internal body representations but on perceptual information coming from peripersonal space.