Phantom Limb Pain Research Articles

How timing and preexisting pain affect outcomes of TMR: a systematic review

Introduction: Targeted muscle reinnervation (TMR) is increasingly common in the care of major limb amputation to limit amputation-related pain. This review aims to elucidate how chronic pain states and length of delay prior to TMR affect its success and outcomes. Methods: Manuscripts were collected from three databases. Articles were first screened and excluded based on exclusion criteria. The remaining manuscripts were independently reviewed to determine inclusion. Article and patient demographics, as well as pain outcomes, were extracted. Data were analyzed based on pain condition, amputation vs. neuroma, and time from amputation/injury to surgery. Results: The literature search yielded 723 articles, with 41 meeting the inclusion criteria. Twenty-one articles included patients with residual limb pain (RLP) and phantom limb pain (PLP), including 14 on amputation and 6 on neuroma excision. Five articles included cancer-related amputation. Complex Regional Pain Syndrome (CRPS) was discussed in 3 articles, ischemia or infection in 2 articles, and neurofibromatosis 1 in 1 article. Twenty-two articles described TMR at the time of amputation. Conclusions: TMR is effective at preventing neuroma formation and limiting pain when performed at the time of amputation. Delayed patients had a greater improvement in RLP but less of an improvement in PLP, when assessed against immediate TMR patients who were compared to non-TMR standard amputees. In the presence of chronic pain states, such as CRPS, there is also improved analgesia. However, current clinical data are limited, indicating a need for further research into the use of TMR for chronic pain management.

Ultrasound-guided pulsed radiofrequency ablation of stellate ganglion in upper-extremity phantom limb pain: a case series

BackgroundPhantom limb pain (PLP) is the most common type of pain experienced by amputees and is chronic and complex, with manifestations including pain in a limb that no longer exists. To date, treatments that are pharmaceutical or surgical in nature are relatively ineffective at bringing much relief as the pathophysiology of PLP is somewhat obscure. Chronic pain syndromes such as PLP may benefit from sympathetic nervous system modulation through the stellate ganglion.Case Ten refractory PLP patients treated with ultrasound-guided stellate ganglion pulsed radiofrequency ablation (SG PRF) after a diagnostic stellate ganglion block took effect: A case series Patients were assessed before and after the treatment at 1 week, 1 month, and 3 months. Significant reductions in pain as measured using a numerical rating scale; Pain Disability Indexwas improved, and Medication Quantification Scale also was improved. Minimal side effects.ConclusionsUltrasound-guided SG PRF has provided promising results for PLP by giving the patient with sustained pain relief and functional improvement without much side effects. Further studies need to be done to validate this finding.

Surgical Complications after Targeted Muscle Reinnervation at a Safety-Net Hospital.

Targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) can reduce neuroma formation and phantom limb pain (PLP) after lower extremity (LE) amputation. These techniques have not been studied in safety-net hospitals. This study aims to examine the surgical complication rates after TMR and/or RPNI at an academic safety-net hospital in an urban setting. This was a retrospective review of patients older than 18 years who had prior above-knee guillotine amputation (AKA) or below-knee guillotine amputation (BKA) and underwent stump formalization with TMR and/or RPNI from 2020 to 2022. Demographics, medical history, and operative and postoperative characteristics were collected. The primary outcome was any surgical complication, defined as infection, dehiscence, hematoma, neuroma, or reoperation. Univariate analysis was conducted to identify variables associated with surgical complications and PLP. Thirty-two patients met the inclusion criteria. The median age was 52 years, and 75% were males. Indications for amputation included diabetic foot infection (71.9%), necrotizing soft tissue infection (25.0%), and malignancy (3.1%). BKA was the most common indication for formalization (93.8%). Most patients (56.3%) had formalization with TMR and RPNI, 34.4% patients had TMR only, and 9.4% had RPNI alone. The incidence of postoperative complications was 46.9%, with infection being the most common (31.3%). The median follow-up time was 107.5 days. There was no significant difference in demographics, medical history, or operative characteristics between patients who did and did not have surgical complications. However, there was a trend toward higher rates of PLP in patients who had a postoperative wound infection (p = 0.06). Overall complication rates after LE formalization with TMR and/or RPNI at our academic safety-net hospital were consistent with reported literature. Given the benefits, including reduced chronic pain and lower health care costs, we advocate for the wider adoption of these techniques at other safety-net hospitals.

Targeted Muscle Reinnervation Compared to Standard Peripheral Nerve Management Following Amputation: A Systematic Review and Meta-Analysis.

Chronic pain remains a significant challenge for individuals following limb amputation, with incidence of painful neuromas, phantom limb pain (PLP), and residual limb pain (RLP). Targeted muscle reinnervation (TMR) is a surgical technique designed to restore motor control information lost during amputation by redirecting residual nerves to new muscle targets. This systematic review and meta-analysis aims to compare patient-reported and functional outcomes following amputation with either TMR or standard neurological treatment (SNT). The study also includes an examination of primary versus secondary TMR and explores outcomes in highly comorbid patient populations. A search of central databases was performed, and meta-analysis was completed on extracted data where possible. Eleven studies were identified. Results indicate a significant reduction in PLP and RLP in patients undergoing TMR compared to SNT using various pain scores. TMR also demonstrates improved functional outcomes and decreased opioid use. Furthermore, results indicated patients who underwent TMR at the time of amputation (primary TMR) had improved pain scores compared with those who had TMR performed later (secondary TMR). The review emphasizes the benefits of TMR as a valuable surgical adjunct for amputee patients, while also highlighting the need for further research, especially in comorbid populations.

Bedside Neuromodulation of Persistent Pain and Allodynia with Caloric Vestibular Stimulation.

Caloric vestibular stimulation (CVS) is a well-established neurological diagnostic technique that also induces many phenomenological modulations, including reductions in phantom limb pain (PLP), spinal cord injury pain (SCIP), and central post-stroke pain. We aimed to assess in a variety of persistent pain (PP) conditions (i) short-term pain modulation by CVS relative to a forehead ice pack cold-arousal control procedure and (ii) the duration and repeatability of CVS modulations. The tolerability of CVS was also assessed and has been reported separately. We conducted a convenience-based non-randomised single-blinded placebo-controlled study. Thirty-eight PP patients were assessed (PLP, n = 8; SCIP, n = 12; complex regional pain syndrome, CRPS, n = 14; non-specific PP, n = 4). Patients underwent 1-3 separate-day sessions of iced-water right-ear CVS. All but four also underwent the ice pack procedure. Analyses used patient-reported numerical rating scale pain intensity (NRS-PI) scores for pain and allodynia. Across all groups, NRS-PI for pain was significantly lower within 30 min post-CVS than post-ice pack (p < 0.01). Average reductions were 24.8% (CVS) and 6.4% (ice pack). CRPS appeared most responsive to CVS, while PLP and SCIP responses were less than expected from previous reports. The strongest CVS pain reductions lasted hours to over three weeks. CVS also induced substantial reductions in allodynia in three of nine allodynic CRPS patients, lasting 24 h to 1 month. As reported elsewhere, only one patient experienced emesis and CVS was widely rated by patients as a tolerable PP management intervention. Although these results require interpretative caution, CVS was found to modulate pain relative to an ice pack control. CVS also modulated allodynia in some cases. CVS should be examined for pain management efficacy using randomised controlled trials.

Reducing phantom limb pain using phantom motor execution enabled by augmented and virtual reality: participants’ perspectives on an innovative treatment

Purpose Phantom limb pain (PLP) is a condition that greatly diminishes quality of life. Phantom motor execution (PME), enabled by myoelectric pattern recognition combined with virtual and augmented reality, is a novel treatment for PLP. Here we, aimed to describe patients’ experiences of this treatment. Material and Methods Qualitative, using semi-structured interviews one month after completed PME treatment. Twenty-one Swedish and Dutch patients (mean age 57, 16 males, 16 lower limb amputations) participated. The analysis followed the framework approach. Results The main themes were 1) treatment effects on the perception of the phantom limb, 2) living with PLP before and after treatment, and 3) facilitators and barriers to treatment. Most participants learned to control their phantom limb, perceived it more positively and as more complete. This control over the phantom limb became a tool for managing PLP. Most participants’ outlook on life and energy levels improved after treatment. Being mentally focused during treatment was important. Therapists were pivotal to the success of the treatment. Conclusion Controlling the phantom limb improved their perception of it and pain management, self-agency, and quality of life. The therapists’ role was invaluable. We suggest training for patients in phantom limb control before and after amputation.

A Case Report of Successful Off-Label Neuromodulation for Concurrent Refractory Sacroiliac Pain and Phantom Limb in a Hip Disarticulation Patient

Hip disarticulation is a morbid procedure for those whose bony or soft tissues are unable to be salvaged. It involves extensive resection, and the patient featured in this report expressed mechanical pain from their sacroiliac joint (SIJ) as well as phantom limb pain (PLP). Spinal cord stimulation is known to assist with neuropathic pain syndromes, and SIJ fusion is effective in these cases of multifactorial pain. This report presents a successful off-label use of thoracic spinal cord stimulation in a complex pain condition consisting of coexisting PLP and mechanical SIJ pain in a hip disarticulation patient.

The effects of neuron morphology and spatial distribution on the selectivity of dorsal root ganglion stimulation

Objective.For prosthesis users, sensory feedback that appears to come from the missing limb can improve function, confidence, and phantom limb pain. Numerous pre-clinical studies have considered stimulation via penetrating microelectrodes at the dorsal root ganglion (DRG) as a potential approach for somatosensory neuroprostheses. However, to develop clinically translatable neuroprosthetic devices, a less invasive approach, such as stimulation via epineural macroelectrodes, would be preferable. This work explores the feasibility of using such electrodes to deliver focal sensory feedback by examining the mechanisms of selective activation in response to stimulation via epineural electrodes compared with penetrating electrodes.Approach.We developed computational models of the DRG, representing the biophysical properties of the DRG and surrounding tissue to evaluate neural responses to stimulation via penetrating microelectrodes and epineural macroelectrodes. To assess the role of properties such as neuron morphology and spatial arrangement we designed three models, including one that contained only axons (axon only), one with pseudounipolar neurons arranged randomly (random), and one with pseudounipolar neurons placed according to a realistic spatial distribution (realistic).Main results.Our models demonstrate that activation in response to stimulation via epineural electrodes in a realistic model is commonly initiated in the axon initial segment adjacent to the cell body, whereas penetrating electrodes commonly elicit responses in t-junctions and axons. Moreover, we see a wider dynamic range for epineural electrodes compared with penetrating electrodes. This difference appears to be driven by the spatial organization and neuron morphology of the realistic DRG.Significance.We demonstrate that the anatomical features of the DRG make it a potentially effective target for epineural stimulation to deliver focal sensations from the limbs. Specifically, we show that epineural stimulation at the DRG can be highly selective thanks to the neuroanatomical arrangement of the DRG, making this a promising approach for future neuroprosthetic development.

ID: 323187 Successful use of Peripheral Nerve Stimulation in a Case of Recalcitrant Phantom Limb Pain

ID: 323187 Successful use of Peripheral Nerve Stimulation in a Case of Recalcitrant Phantom Limb Pain

The home-based mirror therapy in the reduction of phantom limb pain in unilateral below-knee amputees

The home-based mirror therapy in the reduction of phantom limb pain in unilateral below-knee amputees

Peripheral Nerve Blocks as a Predictor of Nerve Reconstruction Success After Major Limb Amputation.

Postamputation pain is a spectrum of debilitating sensations that impacts millions of people in the United States. While the development of postamputation pain, including phantom limb pain (PLP), is multifactorial, it has been associated with disorganized axonal sprouting, resulting in a neuroma and subsequent central nervous system changes. Nerve reconstruction surgeries, such as regenerative peripheral nerve interface (RPNI) and targeted muscle reinnervation (TMR), provide transected nerve fibers with proper target organs for reinnervationand have been shown to significantly reduce PLP. This case series aims to describe perioperative peripheral nerve blocks as a diagnostic tool for identifying patients who would benefit from RPNI or TMR. We conducted a retrospective search of patients who underwent major extremity amputation and who received a diagnostic peripheral nerve block before undergoing reconstructive nerve surgery (TMR and/or RPNI). Six patients (58-80 years old) with below-knee amputations (BKA) were examined. All patients experienced a reduction in postamputation pain (PAP), specifically PLP, after a diagnostic peripheral nerve block (PNB). The average time between amputation and revision surgery was approximately two years (Mean: 22.35 months). Following surgical intervention, all patientsreported a reduction in PLP episodes after nerve reconstruction surgery. Two patients no longer reported PLP.Ambulation rates also improved following revision (50% vs 83%). PNBs can be used as an effective diagnostic tool to identify patients that will significantly benefit from amputation revisions with TMR or RPNI.

Cryoablation in Chronic Pain Management: A Narrative Review

Abstract Cryoneurolysis is a technique of applying extreme cold temperatures to specific sensory nerves, causing a prolonged period of loss of conduction through that nerve. This technique has found widespread application in the field of interventional pain medicine in a variety of conditions including chronic postsurgical pain, phantom limb pain (PLP), and cancer pain. Its use in chronic pain states has been aided further by the advent of handheld cryoneurolysis devices and the widespread use of ultrasonographic imaging to guide and target nerves accurately. Chronic pain states – chronic knee pain from osteoarthritis, refractory PLP, temporomandibular disorders, cervicogenic headaches, low back pain, different peripheral neuropathies, and metastatic bone tumor pain – are some of the conditions where cryoneurolysis has been proven to benefit patients in cases where the symptoms were refractory to other conventionally used modalities. Chronic pain is a complex and multifaceted condition and hence requires a variety of individualized treatment approaches. Current research on this treatment method for chronic pain indicates that it carries low risk and, when used correctly, offers extended pain relief without causing motor function loss. This narrative review includes all types of scientific studies, published between 2010 and 2023, which were selected using a specific set of keywords through two different literature search engines. In conclusion, it explains how cryoneurolysis works to provide long-term pain relief and summarizes the latest evidence supporting its use in chronic pain management.

Clinical Characteristics Associated with the PLP-PLS Index, a New Potential Metric to Phenotype Phantom Limb Pain.

Phantom limb pain (PLP) is highly prevalent after amputation. However, the influence of non-painful sensations (PLS) remains unclear. This study examines the PLP-PLS index as a novel tool to differentiate PLP from PLS and explores the association of clinical factors with the index. We conducted a cross-sectional analysis of baseline data from 112 participants in a previous factorial trial in patients with unilateral traumatic lower limb amputation. Linear regression models were used to examine the associations between the index and various demographic, psychological and clinical factors. Logistic and Poisson regression, and e-value calculation were utilized for sensitivity analyses. Adjusted multivariable linear regression models demonstrated significant associations of phantom movement sensation (β: -1.532; 95% CI: -2.615 to -0.449; p = 0.006) and time since amputation (β: 0.005; 95% CI: 0.0006 to 0.0101; p = 0.026) with the PLP-PLS index. These findings were confirmed by multivariable logistic regression (phantom movement sensation OR: 0.469; 95% CI: 0.200 to 1.099, p = 0.082; time since amputation OR: 1.003; 95% CI: 1.00003 to 1.007; p = 0.048) and sensitivity analyses. Time since amputation and phantom movement sensation likely reflect distinct phenotypes and potential mechanisms for PLP and PLS. The PLP-PLS index is a promising clinical tool for selecting therapies to prevent/treat PLP and for measuring treatment effects to modulate phantom pain. These findings emphasize the importance of understanding the mechanisms underlying PLP and PLS for improving clinical management and guiding future research.

Extended reality used in the treatment of phantom limb pain: a multicenter, double-blind, randomized controlled trial

Abstract Phantom limb pain (PLP) represents a significant challenge after amputation. This study investigated the use of phantom motor execution (PME) and phantom motor imagery (PMI) facilitated by extended reality (XR) for the treatment of PLP. Both treatments used XR, but PME involved overt execution of phantom movements, relying on the decoding of motor intent using machine learning to enable real-time control in XR. In contrast, PMI involved mental rehearsal of phantom movements guided by XR. The study hypothesized that PME would be superior to PMI. A multicenter, double-blind, randomized controlled trial was conducted in 9 outpatient clinics across 7 countries. Eighty-one participants with PLP were randomly assigned to PME or PMI training. The primary outcome was the change in PLP, measured by the Pain Rating Index, from baseline to treatment cessation. Secondary outcomes included various aspects related to PLP, such as the rate of clinically meaningful reduction in pain (CMRP; &gt;50% pain decrease). No evidence was found for superiority of overt execution (PME) over imagery (PMI) using XR. PLP decreased by 64.5% and 68.2% in PME and PMI groups, respectively. Thirty-seven PME participants (71%) and 19 PMI participants (68%) experienced CMRP. Positive changes were recorded in all other outcomes, without group differences. Pain reduction for PME was larger than previously reported. Despite our initial hypothesis not being confirmed, PME and PMI, aided by XR, are likely to offer meaningful PLP relief to most patients. These findings merit consideration of these therapies as viable treatment options and alternatives to pharmacological treatments.

Analysis of amputations occurring in the earthquakes centered in Kahramanmaraş: Adıyaman experience.

Amputations are a common surgical procedure resulting from trauma during earthquakes, leading to severe disability. This study aims to investigate surgical outcomes specific to amputations that occurred in Adıyaman after the Kahramanmaraş earthquakes. This descriptive study included amputees who presented to Adıyaman University Training and Research Hospital. Between March 6, 2024 and March 29, 2024, amputees were contacted by phone and asked the questions in the form. Data analyzed included demographic information, number and level of amputated extremities, phantom limb pain, stump infection, extrication time, time to initiation of rehabilitation, number of revision, and whether a prosthesis was fitted. The study reached 75 amputees. The mean age was 37.9 ± 19.2, and the most frequently amputated age group was adults. Stump infection was observed in 40 amputees (53.3%), phantom limb pain in 47 (62.6%),and revision in 29 (38.7%). The median extrication time was 36h and initiation of rehabilitation time was 45 days. It was noted that 35 amputees (62.5%) used prostheses. A statistically significant relationship was found between fasciotomy and stump infection (p = .000). Infection was detected in 65% of those who underwent fasciotomy. Earthquake-related amputations most frequently affected the adult age group and primarily involved lower extremity amputations, such as transfemoral and transtibial amputations. Phantom limb pain, need for revision, and infection are common in earthquake-induced amputations. Delayed fasciotomy increases the risk of stump infection. The data obtained in this study will help plan local health services to coordinate amputation care in disasters.

Prevalence and factors associated with psychological morbidity, phantom limb Pain in lower limb amputees

BackgroundLower limb amputation can lead to psychological problems.There is a lack of data to evaluate the psychological problems and associated factors in lower limb amputees. AimPrevalence and factors associated with psychological disorder and phantom limb pain in lower limb amputees MethodsIt was a cross-sectional study with a consecutive sampling technique. Patients were assessed on the Hospital Anxiety and Depression Scale (HADS) for the presence of depression and anxiety disorder. DSM-5 diagnostic criteria for substance use disorder were used, andphantom limb pain was diagnosed as defined by Pare. Results103 patients were included in the present study with a mean age of37.7 ± 14.5 yrs. The majorityof patients were males (87.4 %), married (69.9 %), on paid employment (95.1 %), and were of middle socioeconomic status (83.5 %). Most of the patients presented with roadside accident injuries (83.5 %)and had below-knee amputation (58.3 %). As per DSM-5, 38.8 % had a substance use disorder, out of which 35.9 % and 24.3 % had alcohol and tobacco use disorders, respectively. On HADS, 48.5 % had a presence of depressive disorder, and 30.1 % had anxiety disorder. The majority of patients (97.1 %) had phantom limb pain. Those from rural areas reported significantly more frequency of anxiety (x2-5.501; p-0.019) and depressive disorder (x2-7.009; p-0.008). Lower incomehad a significant positive association with depression (r-0.228; p-0.021) and phantom limb pain (U-22.500; p-0.008). ConclusionThe prevalence of psychiatric morbidity in lower-limb amputeeswas very high. The most common psychological morbidity was depression,followed by anxiety disorder and substance use disorders.Our findings reflect that we would benefit by including mental health professionals asintegral members of the multidisciplinary team to do an early psychological assessment and intervention, which would help prevent psychological illnesses and improve quality of life.

Clinical Practice Guideline: The Treatment of Peripheral Nerve Injuries.

Nerve lesions often heal incompletely, leading to lifelong functional impairment and high costs for the health care system. The updated German clinical practice guideline is intended to promote the early recognition of nerve lesions and the timely initiation of proper treatment for optimal restoration of function. The recommendations are based on an assessment of all the evidence revealed by a systematic search of the literature, as well as on the expertise of the multiprofessional guideline group. Only a few publications contain high-quality evidence. This version of the guideline contains a more detailed discussion of war injuries, iatrogenic injuries, MR neurography, and specific treatments than the previous version. As for the different methods of nerve replacement, a comparison of autologous transplantation versus the use of conduits and tubes revealed no significant difference between these two methods on the mBMRC scale, and minimal superiority of autologous transplantation with respect to two-point discrimination. As for the use of nerve transfers when nerve reconstruction is not feasible or unlikely to succeed, nerve transfer yielded slightly better results than proximal reconstruction for elbow flexion, but the difference did not reach statistical significance (mBMRC ≥ 3: RR 1.16, 95% confidence interval [1.02; 1.32]). The treatment of neuromas with targeted muscle reinnervation was superior to the classic approach in decreasing both stump pain (MD 2.0 +/- 2.8) and phantom limb pain (MD 3.4 +/- 4.03). The delayed or improper treatment of peripheral nerve lesions can lead to severe impairment. Timely diagnosis, the use of appropriate treatments in conformity with the guidelines, and interdisciplinary collaboration among specialists are all essential for optimizing the outcome.

Robotic-Enhanced Prosthetic Liners for Vibration Therapy: Reducing Phantom Limb Pain in Transfemoral Amputees.

Phantom limb pain, a common challenge for amputees, lacks effective treatment options. Vibration therapy is a promising non-pharmacologic intervention for reducing pain intensity, but its efficacy in alleviating phantom limb pain requires further investigation. This study focused on developing prosthesis liners with integrated vibration motors to administer vibration therapy for phantom limb pain. The prototypes developed for this study addressed previous issues with wiring the electronic components. Two transfemoral amputees participated in a four-week at-home trial, during which they used the vibration liner and rated their initial and final pain intensity on a numeric rating scale each time they had phantom pain. Semi-structured interviews were conducted to gather feedback following the at-home trial. Both participants described relaxing and soothing sensations in their residual limb and phantom limb while using vibration therapy. One participant reported a relaxation of his phantom limb sensations, while both participants noted a decrease in the intensity of their phantom limb pain. Participants said the vibration liners were comfortable but suggested that the vibration could be stronger and that aligning the contacts could be easier. The results of this study highlight the potential effectiveness of using vibration therapy to reduce the intensity of phantom limb pain and suggest a vibration liner may be a feasible mode of administering the therapy. Future research should address optimizing the performance of the vibration liners to maximize their therapeutic benefits.

A preliminary study exploring the effects of transcutaneous spinal cord stimulation on spinal excitability and phantom limb pain in people with a transtibial amputation

Objective. Phantom limb pain (PLP) is debilitating and affects over 70% of people with lower-limb amputation. Other neuropathic pain conditions correspond with increased spinal excitability, which can be measured using reflexes andF-waves. Spinal cord neuromodulation can be used to reduce neuropathic pain in a variety of conditions and may affect spinal excitability, but has not been extensively used for treating PLP. Here, we propose using a non-invasive neuromodulation method, transcutaneous spinal cord stimulation (tSCS), to reduce PLP and modulate spinal excitability after transtibial amputation.Approach. We recruited three participants, two males (5- and 9-years post-amputation, traumatic and alcohol-induced neuropathy) and one female (3 months post-amputation, diabetic neuropathy) for this 5 d study. We measured pain using the McGill Pain Questionnaire (MPQ), visual analog scale (VAS), and pain pressure threshold (PPT) test. We measured spinal reflex and motoneuron excitability using posterior root-muscle (PRM) reflexes andF-waves, respectively. We delivered tSCS for 30 min d-1for 5 d.Main Results. After 5 d of tSCS, MPQ scores decreased by clinically-meaningful amounts for all participants from 34.0 ± 7.0-18.3 ± 6.8; however, there were no clinically-significant decreases in VAS scores. Two participants had increased PPTs across the residual limb (Day 1: 5.4 ± 1.6 lbf; Day 5: 11.4 ± 1.0 lbf).F-waves had normal latencies but small amplitudes. PRM reflexes had high thresholds (59.5 ± 6.1μC) and low amplitudes, suggesting that in PLP, the spinal cord is hypoexcitable. After 5 d of tSCS, reflex thresholds decreased significantly (38.6 ± 12.2μC;p< 0.001).Significance. These preliminary results in this non-placebo-controlled study suggest that, overall, limb amputation and PLP may be associated with reduced spinal excitability and tSCS can increase spinal excitability and reduce PLP.

The Test-Retest Reliability of Pain Outcome Measures in People With Phantom Limb Pain.

To quantify the test-retest reliability of 3 patient-reported outcome measures of pain for people living with phantom limb pain (PLP) and assess the impact of test-retest errors on future research and clinical decisions. Thirty-nine participants (30 males), mean (SD) age: 55 (16), mean (SD) years postamputation: 6.8 (8.3), reported their PLP levels on a visual analogue scale (VAS) for pain intensity, the revised short-form McGill Pain Questionnaire (SF-MPQ-2), and a pain diary, on 2 occasions 7 to 14 days apart. Mean systematic change, within-subjects SD, limits of agreement (LOA), coefficient of variation, and the intraclass correlation coefficient (ICC) were quantified alongside their respective 95% confidence intervals (95% CIs). Systematic learning effects (mean changes) were not clinically relevant across the VAS, SF-MPQ-2, and pain diary. Within-subject SDs (95% CI) were 11.8 (9.6-15.3), 0.9 (0.7-1.2), and 8.6 (6.9-11.5), respectively. LOA (95% CI) were 32.6 (26.5-42.4), 2.5 (2-3.3), and 23.9 (19.2-31.8), respectively. ICCs (95% CI) were 0.8 (0.6-0.9), 0.8 (0.7-0.9), and 0.9 (0.8-0.9), respectively, but may have been inflated by sample heterogeneity. The test-retest errors allowed detection of clinically relevant effect sizes with feasible sample sizes in future studies, but individual errors were large. For people with PLP, a pain intensity VAS, the SF-MPQ-2, and a pain diary show an acceptable level of intersession reliability for use in future clinical trials with feasible sample sizes. Nevertheless, the random error observed for all 3 of the pain outcome measures suggests they should be interpreted with caution in case studies and when monitoring individuals' clinical status and progress.