Peripheral Nerve Stimulation on the Brachial Plexus With Ultrasound-guided Percutaneous Technique: A Case Series.

INTRODUCTION: The aim of this case series was to assess the safety and effectiveness of peripheral nerve stimulation (PNS) of the brachial plexus performed using a low invasive percutaneous approach with ultrasound guide. MATERIALS AND METHODS: Patients affected by neuropathic pain with a documented brachial plexus partial avulsion were included in this observational study. A totally implantable PNS system specifically designed for peripheral placement (Neurimpulse, Padua, Italy) was implanted and followed for 18 months, recording the level of pain (Numeric Rating Scale [NRS]), therapy satisfaction (Patient Global Impression of Improvement), quality of life (Short Form Health Survey questionnaire), and change in drug consumption and work status. Descriptive statistic (mean and SD) was used to compare pre- and postimplantation differences. RESULTS: A total of 18 patients were included in the observational study; 16 of them proceeded with the permanent implantation. System infection (N = 1) and lead migrations (N = 2) were recorded during a follow-up mean of 14.8 ± 5.4 months. The average NRS reduction at 18 months was 41%. Average quality-of-life physical and mental indexes increased by 14% and 32%, respectively. Drug intake was stopped in 22% and reduced in 56% of the patients. CONCLUSIONS: PNS systems of the brachial plexus implanted with percutaneous approach appear to be safe and effective in a follow-up period of 18 months. Longer and larger studies are needed to confirm and extend these outcomes.

Applicability and Validity of an e-Health Tool for the Appropriate Referral and Selection of Patients With Chronic Pain for Spinal Cord Stimulation: Results From a European Retrospective Study.

OBJECTIVES: To support rational decision-making on spinal cord stimulation (SCS), a European expert panel developed an educational e-health tool using the RAND/University of California at Los Angeles Appropriateness Method. This retrospective study aimed to determine the applicability and validity of the tool using data from patients for whom SCS had been considered. MATERIALS AND METHODS: A total of 12 European implant centers retrieved data from 25 to 50 consecutive patients for whom SCS was considered in 2018-2019. For each patient, data were captured on the clinical and psychosocial variables included in the e-health tool, center decisions on SCS, and patient outcomes. Patient outcomes included global perception of effect by the patient and observer, and pain reduction (numeric pain rating scale) at six-month follow-up. RESULTS: In total, 483 patients were included, of whom 133 received a direct implant, 258 received an implant after a positive trial, 32 had a negative trial, and 60 did not receive SCS for reasons other than a negative trial. The most frequent indication was persistent spinal pain syndrome type 1 and type 2 (74%), followed by neuropathic pain syndromes (13%), complex regional pain syndrome (12%), and ischemic pain syndromes (0.8%). Data on the clinical and psychosocial variables were complete for 95% and 93% of patients, respectively, and missing data did not have a significant impact on the study outcomes. In patients who had received SCS, panel recommendations were significantly associated with patient outcomes (p < 0.001 for all measures). Substantial improvement ranged from 25% if the e-health tool outcome was "not recommended" to 83% if SCS was "strongly recommended". In patients who underwent a trial (N = 290), there was 3% of trial failure when SCS was "strongly recommended" vs 46% when SCS was "not recommended". CONCLUSIONS: Retrospective application of the e-health tool on patient data showed a strong relationship between the panel recommendations and both SCS trial results and treatment outcomes.

Common-sense model of self-regulation to cluster fibromyalgia patients: results from a cross-sectional study in Italy.

OBJECTIVES: Fibromyalgia is a severe and disabling chronic pain syndrome affecting millions of people worldwide. Various patients' subgroups were identified using different atheoretical measures, hardly effective to tailor treatments. Previous literature findings showed the relevance of fibromyalgia patients' illness perceptions in adjusting to the disease. The present study aims to identify clusters of fibromyalgia patients based on their illness perceptions and investigate whether they can differ across pain, mood, physical functioning, catastrophising, and pain acceptance measures. METHODS: Fifty-three newly referred fibromyalgia patients completed clinical and psychological questionnaires. Patients' subgroups were created by applying hierarchical cluster analysis to their answers to Illness Perception Questionnaire-Revised subscales. Potential differences across subgroups in outcome variables were tested. RESULTS: Cluster analysis identified two patient groups. Group A (32 patients) had a higher representation of fibromyalgia as a chronic disease with severe consequences, lower beliefs in personal and treatment control, and a higher fibromyalgia-related emotional distress than group B (21 patients). Clusters did not differ on pain intensity and duration. Group A, compared to group B, showed worse physical functioning and overall impairment due to fibromyalgia, a poorer psychological condition, a higher tendency to catastrophise, and less pain acceptance. CONCLUSIONS: Study findings reveal two fibromyalgia subgroups differing in emotional suffering and impairment despite similar pain intensity and duration. Patients' illness perceptions and attitudes towards pain, like catastrophising and acceptance, might be critical in adjusting to the disease. A detailed assessment of such risk and protective factors is critical to differentiate patients' subgroups with different needs and thus offering tailored treatments.

Cerebellar Transcranial Direct Current Stimulation (ctDCS) Ameliorates Phantom Limb Pain and Non-painful Phantom Limb Sensations.

Phantom limb pain (PLP) is a disabling and intractable sensation arising in about 80% of patients after amputation. The aim of this study was to evaluate the possibility to modulate nociceptive processing and pain perception with cerebellar transcranial direct current stimulation (ctDCS) in patients suffering from painful and non-painful phantom limb sensations. Fourteen upper limb amputees underwent ctDCS (anodal or sham, 2.0 mA, 20 min per day, 5 days a week). Clinical scores and electrophysiological parameters were assessed before tDCS, at the end of the 5-day treatment, 2 and 4 weeks later. Laser-evoked potentials (LEPs) were obtained from the stump using a Nd:YAP laser by pulses with short duration (5 ms) and small diameter spots (5 mm). Changes in visual analogue scores (VAS) were evaluated (chronic pain, paroxysmal pain, stump pain, phantom movements, phantom sensations). Anodal polarization significantly dampened LEP amplitudes (N1, p = 0.021 and N2/P2, p = 0.0034), whereas sham intervention left them unchanged. Anodal ctDCS significantly reduced paroxysmal pain (p < 0.0001), non-painful phantom limb sensations (p < 0.0001) and phantom limb movements (p = 0.0003), whereas phantom limb and stump pain did not change compared to the sham condition. Anodal ctDCS significantly improves both paroxysmal pain and non-painful phantom limb sensations, which are likely induced by maladaptive changes in the sensorimotor network and posterior parietal cortex respectively.

Are Multidimensional Pain Inventory Coping Strategy Profiles Associated with Long-Term Spinal Cord Stimulation Effectiveness?

Introduction: It is acknowledged that the way patients cope with pain may influence treatment outcome. In particular, psychological factors are deemed important when considering patients for suitability for spinal cord stimulation (SCS). Objective: The aim of the study is to observe how pre-implantation psychological characteristics impact the effectiveness of SCS for chronic pain. Methods: The analysis comprised data from 137 patients who underwent an SCS implant. Screening evaluation included a coping strategies profile (Multidimensional Pain Inventory) and psychiatric disorders (Mini-International Neuropsychiatric Interview). Based on SCS implant outcome collected during follow-up visits, patients were divided into three groups: subjects with long-term pain relief (long-term group), subjects who failed the SCS treatment and decided to explant trial device (trial explanter group [TE]), and those who chose a permanent device (permanent explanter group [PE]). Results: Results showed that most of the patients who failed with the SCS (TE and PE groups) demonstrated a dysfunctional coping profile and showed a higher presence of psychiatric disorders, which significantly influenced the experience and perception of pain. Conclusions: The findings of this study support the value of a multidisciplinary screening. Addressing psychological issues before SCS implantation can reduce the failure rate of SCS.

Neurophysiological Comparison Among Tonic, High Frequency, and Burst Spinal Cord Stimulation: Novel Insights Into Spinal and Brain Mechanisms of Action.

RATIONALE: Spinal cord stimulation (SCS) is an effective option for neuropathic pain treatment. New technological developments, as high-frequency (HF) and theta burst stimulation (TBS), have shown promising results, although putative mechanisms of action still remain debated. METHODS: thirty patients with lower back pain were enrolled and underwent LF, HF, and TBS. Laser evoked potentials (LEPs) were recorded by using a Nd:YAG laser. Amplitudes and latencies of the main two components (N1, N2/P2) were compared among different experimental sessions. Changes in resting motor threshold (RMT), cortical silent period (cSP), short intracortical inhibition (SICI), and intracortical facilitation (ICF) were also evaluated. RESULTS: TBS dampened LEP amplitudes compared with LF (N1: p = 0.032; N2/P2: p < 0.0001) and HF stimulation (N1: p = 0.029; N2/P2: p < 0.0001, Holm-Sidak post-hoc test). Concurrently, TBS increased N1 latency, when compared with baseline and LF stimulation (p = 0.009 and 0.0033). Whereas RMT and SICI did not change among experimental conditions, TBS significantly prolonged cSP duration compared with baseline (p = 0.002), LF (p = 0.048), and HF-SCS (p = 0.016); finally, both HF (p = 0.004) and TBS (p = 0.0039) increased ICF. CONCLUSION: TBS modulates medial and lateral pain pathways through distinct mechanisms, possibly involving both GABA(a)ergic and Glutamatergic networks at an intracortical level. These results may have implications for therapy and for the choice of best stimulation protocol.

Can a psychologically based treatment help people to live with chronic pain when they are seeking a procedure to reduce it?

OBJECTIVE: At present, the potential benefits of psychologically oriented approaches to pain management for patients waiting to undergo medical interventions, such as neuromodulation, remain unclear. Therefore, this study aimed to examine the results of an interdisciplinary treatment based on principles of Acceptance and Commitment Therapy (ACT) delivered to a group of patients being considered for a neuromodulation procedure. DESIGN: Participants were 86 adults with chronic pain. All were referrals to a 2-week, interdisciplinary, residential pain management course for people being considered for a later neuromodulation procedure. Patients completed standard self-report measures of outcome and treatment process at the beginning and end of the 2-week treatment. Data on progression on the neuromodulation pathway were extracted from medical records. RESULTS: After the 2-week ACT-based interdisciplinary treatment, the majority of patients showed a clinically significant improvement on pain, depression, physical functioning, social functioning, and pain acceptance. Regression analyses indicated that change in pain acceptance related to improvements in depression, mental health, physical function, and social function. Results with regard to the trial of neuromodulation revealed that patients who did not proceed to the trial at their physician's request (n = 13) reported significantly worse depression and mental health, and lower levels of pain acceptance and committed action following the 2-week program compared with those who went for the trial. CONCLUSION: People seeking medical interventions to reduce pain appear able to benefit from an interdisciplinary treatment aimed to improve daily functioning and mental health through increased psychological flexibility.

An Italian Survey and Focus Groups on Fibromyalgia Impairment: Impact on Work and Possible Reasonable Accommodations.

Fibromyalgia symptoms affect the sufferers' working life; however, through reasonable accommodations in workplaces, they can continue to work satisfactorily. There are no Italian studies on factors that facilitate or hinder fibromyalgia-affected people's working life. Our objective was to explore, in a pre-pandemic setting, the quality of working life of fibromyalgia sufferers and reasonable accommodations to improve it. Quantitative and qualitative methods were applied; a survey-questionnaire, participatory-developed, was online-administered to a sample of self-reported FM sufferers (N = 1176). Then, two Focus Groups (FGs), involving 15 fibromyalgia-affected women, were held. Data were analyzed by a thematic analysis approach. Among survey-respondents, 20% were unemployed and only 14% went to work gladly. Variability of pain (84%) and fatigue (90%) were the most perceived reasons for difficulties at work. Negative relationships at work were reported by most participants. The FGs' discussions addressed different strategies for overcoming the main obstacle of "not being believed by colleagues and employers" and reasonable accommodations. However, a negative hopeless attitude towards the solution of problems at work was also apparent. Different critical issues in the workplace emerged from the survey and the FGs. Coordinated actions, according to a transdisciplinary approach, are needed to manage fibromyalgia-induced difficulties in the workplace.

Patients with Chronic Pain: Are Mindfulness Traits Protective Against Distress, Anxiety and Depression?

Objective: To investigate mindfulness traits/attitudes as protective factors against chronic pain related distress, depression and anxiety. Method: Fifty patients (25 with chronic non-oncologic pain-NOP; 25 with chronic oncologic pain-COP) were administered with the following scales: Visual Analogue Scale (VAS), Pain Disability Index (PDI), Italian Questionnaire for Pain (QUID), Perceived Stress Scale (PSS), State and Trait Anxiety Scale (STAY-y1 module), Beck Depression Inventory II (BDI-II), Pittsburgh Sleep Quality Index (PSQI), Psychological General Well Being Index (PGWBI), Mindful Attention Awareness Scale (MAAS). Results: MAAS value ≥ 4.38 was adopted as cut-off to compare 'high level of mindfulness' (HM) vs. 'normal level of mindfulness' (NM) attitudes. Twenty-six patients (52%) scored ≥4.38, with no different distribution between NOP and COP. HM patients scored significantly lower than NM patients on PDI 'family/home responsibilities' domain (4.5±3.2 vs. 6.4±2.8; p<.037), and on PSS (17.8±2.6 vs. 20.9±2.5; p<.0001), STAY-y1 (9.4±1.8 vs. 10.3±2.1; p<.0001), BDI-II (7.8±5.0 vs. 17.6±8.6; p<.0001) total scores. HM scored significantly higher than NM patients in all PGWBI domains. A multiple regression analysis was carried out to analyze the predictor variables of PGWB. The most complete model considered the variables MAAS, STAIy and VAS (F=42.21; p<.0001), that accounted for the 71.6% of PGWB variance. MAAS score was the only variable positively predicting for PGWB; STAIy and VAS scores predicted negatively. Conclusions: Chronic pain patients with high levels of mindfulness attitudes experienced less distress, anxiety, depressive symptoms, and more physical and general wellbeing than patients with low levels of mindfulness attitudes.

Patient selection for spinal cord stimulation: The importance of an integrated assessment of clinical and psychosocial factors.

BACKGROUND: A previously developed educational e-health tool considers both clinical and psychosocial factors when selecting patients with chronic pain for spinal cord stimulation (SCS). The validity of the composite recommendations was evaluated in a retrospective study, demonstrating a strong relationship with patient outcomes after SCS. METHODS: An additional retrospective analysis was performed to determine the added value of a psychosocial evaluation as part of the decision-making process on SCS. Data concerned 482 patients who were considered for SCS in 2018-2019. The analysis focused on the relationship between the different layers of the tool recommendations (clinical, psychosocial, composite) with trial results and patient outcomes at 6 months after SCS. Of the initial study population, 381 patients underwent SCS and had follow-up data on at least one of three pain-related outcome measures. RESULTS: Pain improvement was observed in 76% of the patients for whom SCS was strongly recommended based on merely the clinical aspects. This percentage varied by the level of psychosocial problems and ranged from 86% in patients without any compromising psychosocial factors to 60% in those with severe problems. Similarly, the severity of psychosocial problems affected trial results in patients for whom SCS was either recommended or strongly recommended. CONCLUSIONS: The strong relationship between psychosocial factors embedded in the SCS e-health tool and patient outcomes supports an integrated and multidisciplinary approach in the selection of patients for SCS. The educational e-health tool, combining both clinical and psychosocial aspects, is believed to be helpful for further education and implementation of this approach. SIGNIFICANCE STATEMENT: This study confirms the relevance of the psychosocial factors embedded in the educational SCS e-health tool (https://scstool.org/). The strong relationship between the severity of psychosocial factors with patient outcomes supports conducting a comprehensive psychological and behavioural assessment when determining the eligibility of patients for SCS.

Appropriate referral and selection of patients with chronic pain for spinal cord stimulation: European consensus recommendations and e-health tool.

BACKGROUND: Spinal cord stimulation (SCS) is an established treatment for chronic neuropathic, neuropathic-like and ischaemic pain. However, the heterogeneity of patients in daily clinical practice makes it often challenging to determine which patients are eligible for this treatment, resulting in undesirable practice variations. This study aimed to establish patient-specific recommendations for referral and selection of SCS in chronic pain. METHODS: A multidisciplinary European panel used the RAND/UCLA Appropriateness Method (RUAM) to assess the appropriateness of (referral for) SCS for 386 clinical scenarios in four pain areas: chronic low back pain and/or leg pain, complex regional pain syndrome, neuropathic pain syndromes and ischaemic pain syndromes. In addition, the panel identified a set of psychosocial factors that are relevant to the decision for SCS treatment. RESULTS: Appropriateness of SCS was strongly determined by the neuropathic or neuropathic-like pain component, location and spread of pain, anatomic abnormalities and previous response to therapies targeting pain processing (e.g. nerve block). Psychosocial factors considered relevant for SCS selection were as follows: lack of engagement, dysfunctional coping, unrealistic expectations, inadequate daily activity level, problematic social support, secondary gain, psychological distress and unwillingness to reduce high-dose opioids. An educational e-health tool was developed that combines clinical and psychosocial factors into an advice on referral/selection for SCS. CONCLUSIONS: The RUAM was useful to establish a consensus on patient-specific criteria for referral/selection for SCS in chronic pain. The e-health tool may help physicians learn to apply an integrated approach of clinical and psychosocial factors. SIGNIFICANCE: Determining the eligibility of SCS in patients with chronic pain requires careful consideration of a variety of clinical and psychosocial factors. Using a systematic approach to combine evidence from clinical studies and expert opinion, a multidisciplinary European expert panel developed detailed recommendations to support appropriate referral and selection for SCS in chronic pain. These recommendations are available as an educational e-health tool (https://www.scstool.org/).

Paresthesia-Independence: An Assessment of Technical Factors Related to 10 kHz Paresthesia-Free Spinal Cord Stimulation.

BACKGROUND: Spinal cord stimulation (SCS) has been successfully used to treat chronic intractable pain for over 40 years. Successful clinical application of SCS is presumed to be generally dependent on maximizing paresthesia-pain overlap; critical to achieving this is positioning of the stimulation field at the physiologic midline. Recently, the necessity of paresthesia for achieving effective relief in SCS has been challenged by the introduction of 10 kHz paresthesia-free stimulation. In a large, prospective, randomized controlled pivotal trial, HF10 therapy was demonstrated to be statistically and clinically superior to paresthesia-based SCS in the treatment of severe chronic low back and leg pain. HF10 therapy, unlike traditional paresthesia-based SCS, requires no paresthesia to be experienced by the patient, nor does it require paresthesia mapping at any point during lead implant or post-operative programming. OBJECTIVES: To determine if pain relief was related to technical factors of paresthesia, we measured and analyzed the paresthesia responses of patients successfully using HF10 therapy. STUDY DESIGN: Prospective, multicenter, non-randomized, non-controlled interventional study. SETTING: Outpatient pain clinic at 10 centers across the US and Italy. METHODS: Patients with both back and leg pain already implanted with an HF10 therapy device for up to 24 months were included in this multicenter study. Patients provided pain scores prior to and after using HF10 therapy. Each patient's most efficacious HF10 therapy stimulation program was temporarily modified to a low frequency (LF; 60 Hz), wide pulse width (~470 mus), paresthesia-generating program. On a human body diagram, patients drew the locations of their chronic intractable pain and, with the modified program activated, all regions where they experienced LF paresthesia. Paresthesia and pain drawings were then analyzed to estimate the correlation of pain relief outcomes to overlap of pain by paresthesia, and the mediolateral distribution of paresthesia (as a surrogate of physiologic midline lead positioning). RESULTS: A total of 61 patients participated across 11 centers. Twenty-eight men and 33 women with a mean age of 56 ± 12 years of age participated in the study. The average duration of implantable pulse generator (IPG) implant was 19 ± 9 months. The average predominant pain score, as measured on a 0 - 10 visual analog scale (VAS), prior to HF10 therapy was 7.8 ± 1.3 and at time of testing was 2.5 ± 2.1, yielding an average pain relief of 70 ± 24%. For all patients, the mean paresthesia coverage of pain was 21 ± 28%, with 43% of patients having zero paresthesia coverage of pain. Analysis revealed no correlation between percentage of LF paresthesia overlap of predominant pain and HF10 therapy efficacy (P = 0.56). Exact mediolateral positioning of the stimulation electrodes was not found to be a statistically significant predictor of pain relief outcomes. LIMITATIONS: Non-randomized/non-controlled study design; short-term evaluation; certain technical factors not investigated. CONCLUSION: Both paresthesia concordance with pain and precise midline positioning of the stimulation contacts appear to be inconsequential technical factors for successful HF10 therapy application. These results suggest that HF10 therapy is not only paresthesia-free, but may be paresthesia-independent.