Psychosocial characteristics of candidates for implantable pain devices: validation of an assessment model.

Aim: To provide a detailed profile of Veteran and community patients with chronic pain who completed preprocedural psychological evaluations for implantable pain devices. Patients & methods: A total of 157 candidates completed a preimplantable pain device evaluation between June 2018 and October 2019 with a pain psychologist that included a structured interview, elicitation of patient-centered goals for the implantable device, and psychometric testing. Results: Candidates demonstrated moderate to high rates of sleep impairment (73%), depressive symptoms (62%), anxiety symptoms (61%), pain catastrophizing (37%), cognitive impairment screen (30%) and somatic symptoms (24%). Conclusion: Candidates for implantable pain devices report high rates of mood, sleep and cognitive impairment, reinforcing the value of preprocedural psychological evaluations.

Can Alzheimer's Disease Be Prevented? First Evidence from Spinal Stimulation Efficacy on Executive Functions.

BACKGROUND: Recently, a growing body of evidence has shown that, from the early stage of impairment, Alzheimer's patients (AD) present difficulties on a variety of tasks mostly relying on executive functions. These strongly impact their daily life activities causing a severe loss of independency and autonomy. OBJECTIVE: To evaluate the efficacy of transpinal direct current stimulation (tsDCS) combined with cognitive trainings for improving attentional and executive function abilities in a group of AD patients. METHODS: In a randomized-double blind design, sixteen AD patients underwent different cognitive trainings combined with tsDCS. During the treatment, each subject received tsDCS (20 min, 2 mA) over the thoracic vertebrae (IX-X vertebrae) in two different conditions: 1) anodal, and 2) sham while performing three computerized tasks: alertness, selective attention, and executive functions. Each experimental condition was run in ten consecutive daily sessions over two weeks. RESULTS: After anodal tsDCS, a greater improvement in executive functions compared to sham condition was found. More importantly, the follow-up testing revealed that these effects lasted over 1 month after the intervention and generalized to the different neuropsychological tests administered before, after the treatment and at one month after the end of the intervention. This generalization was present also in the attentional domain. CONCLUSION: This evidence emphasizes, for the first time, that tsDCS combined with cognitive training results efficacious for AD patients. We hypothesize that enhancing activity into the spinal sensorimotor pathways through stimulation improved cognitive abilities which rely on premotor activity, such as attention and executive functions.

Pain relief and improvement in quality of life with 10 kHz SCS therapy: Summary of clinical evidence.

OBJECTIVE: Chronic pain is a prevalent condition which has a significant effect on the lives of those it impacts. High-frequency 10 kHz spinal cord stimulation (10 kHz SCS) has been shown to provide paresthesia-free pain relief for a wide variety of pain indications. This article summarizes the current and emerging data as they relate to the clinical use of the therapy in various pain syndromes. METHODS: A literature search was conducted using the PubMed electronic database using keywords related to 10 kHz SCS. The database was queried from 2013 to May 2019. Articles reporting clinical studies that included human subjects permanently treated with 10 kHz SCS (Senza® system) were included in the review. Recent and relevant conference proceedings known to the authors were also included. RESULTS: The selected literature demonstrated significant evidence for the efficacy of 10 kHz SCS in treating chronic back and leg pain (CBLP), including a randomized, controlled trial as well as prospective and retrospective studies. One-year follow-up responder rates (pain relief ≥50%) ranged from 60% to 80%. Other studies and case series showed promising outcomes in specific conditions, including nonsurgical refractory back pain, neuropathic limb pain, complex regional pain syndrome, chronic widespread pain, chronic pelvic pain, and intractable headache. Subgroup analyses also pointed toward the potential of 10 kHz SCS being successful when low-frequency SCS has failed. The vast majority of these studies reported improved quality of life (QOL) metrics and/or reduced opioid consumption. CONCLUSIONS: Level I evidence already exists for the efficacy of 10 kHz SCS in treating CBLP, supported by real-world clinical experience. Other studies demonstrate the potential of the therapy across a range of chronic pain etiologies, although larger confirmatory studies are recommended. Overall, the literature suggests that the therapy is associated with improved QOL as well as reduced opioid consumption.

Assessment of spinal cord stimulation and radiofrequency: Chronic pain and psychological impact.

Pain has a major impact on anxiety and depression levels. The aim of this study is to demonstrate how these symptoms (depression and anxiety) could positively influence the perception of pain after neurostimulation system implantation.We enrolled 100 patients and divided in 2 different groups, by using tests screening such as Beck Depression Inventory (BDI), Hamilton Anxiety Rating Scale (HAM-A), Nursing Rating Scale (NRS): the group with spinal cord stimulation (SCS) and the group with pulsed spinal cord radiofrequency (RFP).We highlighted a significant decrease of scores (BDI, HAM-A, NRS) in each group between T0 (baseline) and T1. Moreover, the intra-group analysis showed a positive significant correlation between NRS and depressive and anxiety symptoms.We assert that the use of alternative methods (SCS and RFP) to the traditional pharmaceutical-surgical treatments, provide the reduction of the algic and anxiety-depressant symptoms, restoring also the perception of psychological well-being.

Goal Identification Before Spinal Cord Stimulation: A Qualitative Exploration in Potential Candidates.

INTRODUCTION: Due to the difficulties encountered in the treatment process of patients with chronic pain, it is of utmost importance to involve patients themselves in their rehabilitation trajectory. Patient engagement can be obtained by motivating patients to select their own treatment goals. We hypothesize that applying goal setting, as a form of patient empowerment, in potential candidates for spinal cord stimulation (SCS) may further improve the outcome of SCS. As a first step in creating patient empowerment, patients' goals that they aim to achieve with SCS will be explored. METHODS: Fifteen patients suffering from failed back/neck surgery syndrome and scheduled for SCS were interviewed in depth. All interviews were audio recorded and analyzed using in vivo coding. Afterwards, the International Classification of Functioning, Disability and Health framework was used to structure the responses of patients. RESULTS: In the domain of bodily functions, all patients mentioned pain reduction, and 1 patient wanted to regain his previous sleep pattern. In the domain of activities, walking, sitting, driving a car, bending down, and picking up were the highest ranked goals. Regaining a social life was the highest ranked goal for participation. Eleven patients wanted to regain a feeling of happiness, and 5 patients wanted to focus on avoiding depression. CONCLUSION: The interviews revealed a broad spectrum of individual patients' goals, highlighting the need of individually targeted rehabilitation trajectories in the field of neuromodulation. Goal identification could entail the first step towards individualized medicine in the SCS trajectory.

Elucidating somatization in a dimensional model of psychopathology across medical settings.

Research using a categorical-polythetic classification system for mental illness has raised concern regarding the validity of categorical classification systems. Recent efforts suggest psychopathology is better understood from a dimensional framework, though there has been varying evidence of a somatization factor. The current investigation seeks to produce and validate a dimensional model of psychopathology, with a particular emphasis on the placement of somatization, across three nonoverlapping medical samples. Using a bariatric surgery seeking sample (n = 1,268), a spine surgery/spinal cord stimulator seeking sample (n = 1,711), and a chronic pain treatment seeking sample (n = 1,388), a dimensional model of psychopathology was replicated across all three samples using a dimensional measure of psychopathology (the Minnesota Multiphasic Personality Inventory-2-Restructured Form [MMPI-2-RF]). Clear evidence of a separate somatization factor was found in addition to broad internalizing, externalizing, and social detachment factors. Constructs assessable with the model yielded good convergent and discriminant validity coefficients with external criteria, and further supported the presence of a higher-order somatization construct. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

An Exploration of the Experiences and Educational Needs of Patients With Failed Back Surgery Syndrome Receiving Spinal Cord Stimulation.

OBJECTIVE: To explore the experience of spinal cord stimulation (SCS) for patients with failed back surgery syndrome (FBSS). METHODS: Adults with FBSS referred for SCS underwent semistructured interviews at three time points: before their SCS trial, after the trial, and three months after receiving the SCS implant. The face-to-face interviews were audio recorded, transcribed verbatim and analyzed thematically. RESULTS: Twelve adults (8 male, 4 female, aged 38-80 years, pain duration 1-26 years) were recruited. Six themes were identified; 1) What should I expect? 2) Varied outcomes, 3) Understanding pain and this new treatment, 4) Experiences of the SCS journey, 5) Getting used to the device, and 6) Finding out what I need to know. Participants' expectations were varied and the procedures were broadly viewed as minor surgery. Participants' expectations about SCS were not limited to pain relief and included reductions in medication, better sleep, and increased physical activity. Participants' understanding of pain and how SCS purports to work was limited. Throughout the process, practical challenges were identified such as the surgical wound management and battery recharging. Participants received information from multiple sources and identified a range of key information needs including a quick-start guide on how to operate the device and a list of dos and don'ts. CONCLUSIONS: Overall, participants' understanding of SCS was limited. The value participants placed on understanding of the process varied markedly. A list of practical informational needs has been identified. Bespoke, user-friendly, informational tools should be developed from this list to enhance the patient experience of SCS.

Determinants for Meaningful Clinical Improvement of Pain and Health-Related Quality of Life After Spinal Cord Stimulation for Chronic Intractable Pain.

OBJECTIVES: Previous studies demonstrated significant improvement in mean pain scores and quality of life (QOL) scales in patients with chronic pain who underwent spinal cord stimulation (SCS). However, the number of individuals who experience relevant improvements in QOL, termed the meaningful clinical improvement (MCI), is not known. The present study investigated changes in pain measurements based on MCI after SCS. MATERIALS AND METHODS: Thirty-four patients with chronic intractable pain completed scales of pain (visual analogue scale [VAS]), QOL (SF-36), and psychological dimensions during a 22-month follow-up period (mean). Patient-centered MCI of the VAS and SF-36 domain scores were determined based on the MacNab criteria of surgical global effectiveness. Independent presurgical predictors for MCI in the VAS and SF-36 domains were analyzed using multiple binary logistic regression. RESULTS: There was significant improvement of pain and QOL after the SCS (p < 0.00001). Twenty-three patients (67.6%) reached an MCI of pain, and 16 (47.7%)-23 (67.7%) reported an MCI of QOL. Predictors of MCI included ≥80% paresthesia coverage of the painful area, lower levels of anxiety and catastrophizing symptoms, shorter pain duration, female gender and no use of opioids before surgery. MCI of pain and QOL was observed in 50%-70% of patients with chronic pain after SCS. CONCLUSIONS: The identification of determinants for MCI is a challenge to improve the accuracy of prognostic models in SCS for patients with chronic pain. Our results, if confirmed in other populations with a larger sample size, have implications for patients with chronic pain who are candidates for SCS treatment.

The primary diagnosis and the coexisting anxiety disorders have no impact on the additional surgical procedure after spinal cord stimulators implantation: An analysis of 11,029 patients.

Studies have demonstrated superior outcomes and cost effectiveness of the spinal cord stimulation (SCS) for the treatment of chronic pain syndromes such as failed back surgery syndrome (FBSS) or complex regional pain syndrome (CRPS). However, little is known about the impact of primary diagnosis or mental disorders on the revision rate. This is the Retrospective cohort study to analyze the reintervention rates based on the primary diagnosis or comorbid mental disorder. Data of the annual trends of SCS use, revision and removal rate of SCS and additional surgical rate after removal was collected and analyzed for patients undergoing SCS between 2007 and 2015, within a private insurance billing database. Trial cases were excluded from this study. The results showed 11,029 patients received SCS implantation with percutaneous electrodes (PE, n = 7418) or surgical electrode (SE, n = 3611). There was a trend of increasing use of SCS from 2007 to 2013, followed by a decrease in last two years. There was no significant difference in the neither removal nor revision rate regardless between the patients with FBSS or CRPS at each time point. Although the removal rates within 2 years were significantly higher in the patients with anxiety disorders compared to the patients without any mental disorders (PE: p < .001, SE: 0.003), the rate of additional surgery after the removal showed no significant difference (PE: p = .532, SE: p = .262). Therefore, we concluded that the primary diagnosis and the presence of anxiety disorders did not have an impact on the additional surgical rate following SCS implantation.

Measuring Emotional Intelligence Enhances the Psychological Evaluation of Chronic Pain.

The assessment of emotional factors, in addition to other psychosocial factors, has been recommended as a means of identifying individuals with chronic pain who may not respond to certain pain treatments. Systematic reviews of the evidence regarding the prediction of responsiveness to a treatment called the spinal cord stimulator (SCS) have yielded inconclusive results. Emotional intelligence is a term which refers to the ability to identify and manage emotions in oneself and others and has been shown to be inversely associated with emotional distress and acute pain. This study aims to investigate the relationship between emotional intelligence, chronic pain, and the more established psychosocial factors usually used for SCS evaluations by clinical psychologists in medical settings. A sample of 112 patients with chronic pain on an acute hospital waiting list for SCS procedures in a pain medicine service were recruited. Psychological measures were completed including: a novel measure of emotional intelligence; usual measures of emotional distress and catastrophizing; and a numerical rating scale designed to assess pain intensity, pain-related distress, and interference. As predicted, findings revealed significant associations between most of the measures analyzed and current pain intensity. When entered into a simultaneous regression analysis, emotional intelligence scores remained the only significant predictor of current pain intensity. There are potential clinical, ethical, and organizational implications of emotional intelligence processes partially predicting pain in patients on a waiting list for a medical procedure. These results may offer new insight, understanding, and evaluation targets for clinical psychologists in the field of pain management.

Prospective Evaluation of Patient Usage of Above and Below Threshold Waveforms With Traditional Spinal Cord Stimulation Devices.

OBJECTIVES: Spinal cord stimulation (SCS) is an efficacious therapy used to treat chronic pain. The type of SCS programming is important in improving patients' quality of life and overall satisfaction. In this study, 19 patients who underwent SCS with traditional devices were given between 4 and 6 programs including programs with stimulation below sensory threshold and above sensory threshold. Usage patterns and preferences were assessed. METHODS: SCS patients were given 4-6 programs, some above sensory threshold and some below threshold immediately postoperatively after permanent implantation. Usage patterns of different programs were documented, including percent of time that the settings were used and preference for above threshold vs. below threshold settings during sleeping, walking, sitting, and vigorous activity. Improvements at three months in Oswestry disability index (ODI), numeric rating scale (NRS), Beck depression inventory (BDI), McGill pain questionnaire (MPQ), pain catastrophizing scale (PCS), insomnia severity index (ISI), and Epworth sleepiness scale (ESS) were evaluated. RESULTS: Patients were all trialed on above sensory threshold programs. Six weeks after implantation, most patients preferred above threshold stimulation (74%) vs. below threshold waveforms (21%). Patient diagnosis, type/location of lead or recharging burden played no role in patient preference. Above threshold patients had significantly better improvement in BDI scores than did below threshold patients (p < 0.05) at three-month follow-up but also had worse ESS scores (p < 0.05). Above threshold stimulation was preferred for walking and sitting (p < 0.05). CONCLUSIONS: Results indicate that when given the option between waveforms inducing paresthesias and those that do not, SCS patients tend to prefer waveforms that induce paresthesias. Among users of above threshold waveforms, there was preference for these settings during walking and sitting. There was a trend for below threshold preference in vigorous activity and sleeping.

Associations Between Pre-Implant Psychosocial Factors and Spinal Cord Stimulation Outcome: Evaluation Using the MMPI-2-RF.

Spinal cord stimulation (SCS) has variable effectiveness in controlling chronic pain. Previous research has demonstrated that psychosocial factors are associated with diminished results of SCS. The objective of this investigation is to examine associations between pre-implant psychological functioning as measured by the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) and SCS outcomes. SCS candidates at two sites (total N = 319) completed the MMPI-2-RF and measures of pain, emotional distress, and functional ability as part of a pre-implant psychological evaluation. At an average of 5 months post-implant, patients completed the measures of pain and emotional distress a second time. Poorer SCS outcomes and poorer patient satisfaction were associated with higher pre-implant MMPI-2-RF scores on scales used to assess emotional dysfunction, somatic/cognitive complaints, and interpersonal problems. Ways through which pre-implant psychological evaluations of spinal cord stimulator candidates can be informed by MMPI-2-RF findings are discussed.

Analysis of psychological characteristics impacting spinal cord stimulation treatment outcomes: a prospective assessment.

BACKGROUND: Psychological factors are recognised as influencing the outcome of spinal cord stimulation (SCS) although there is currently no consensus as to which factors impact upon SCS efficacy. OBJECTIVE: To identify psychological characteristics that may impact the efficacy of SCS. STUDY DESIGN: Prospective evaluation. SETTING: Single secondary care center in Dudley, United Kingdom. PATIENTS: Seventy-five patients were initially recruited and 56 patients (31 women and 25 men) were followed-up for 12-months. INTERVENTION: SCS for the management of chronic non-cancer pain. MAIN OUTCOME MEASURES: Outcome measures assessed at baseline, 6 months, and 12 months following SCS implantation included the visual analogue scale (VAS), Oswestry disability index (ODI), hospital anxiety and depression (HAD) scale, and the pain coping strategies questionnaire (PCSQ). RESULTS: Statistically significant improvements were observed for the VAS (P < 0.001), ODI (P = 0.011), anxiety (P = 0.042), and depression (P = 0.010) in the HAD scale and for the subscales reinterpreting pain sensation (P = 0.018), control over pain (P = 0.001), and ability to decrease pain (P < 0.001) of the PCSQ. We observed that depression and autonomous coping (control over pain, ability to reduce pain, and catastrophizing) may impact sensory aspects such as pain intensity and disability scores affecting the outcome of SCS treatment. Age at time of implant and duration of pain prior to implant were also found to impact SCS efficacy. LIMITATIONS: It has been reported that loss of analgesia may be experienced within 12 to 24 months following SCS implantation and therefore, it would be of interest to follow patients over a longer period. CONCLUSIONS: This study demonstrates that psychological aspects such as depression and autonomous coping may impact SCS treatment. Addressing these issues prior to SCS implantation may improve SCS long-term outcome.

Dynamic Pain Phenotypes are Associated with Spinal Cord Stimulation-Induced Reduction in Pain: A Repeated Measures Observational Pilot Study.

OBJECTIVE: Spinal cord stimulation (SCS) has become a widely used treatment option for a variety of pain conditions. Substantial variability exists in the degree of benefit obtained from SCS and patient selection is a topic of expanding interest and importance. However, few studies have examined the potential benefits of dynamic quantitative sensory testing (QST) to develop objective measures of SCS outcomes or as a predictive tool to help patient selection. Psychological characteristics have been shown to play an important role in shaping individual differences in the pain experience and may aid in predicting responses to SCS. Static laboratory pain-induction measures have also been examined in their capacity for predicting SCS outcomes. METHODS: The current study evaluated clinical, psychological and laboratory pain measures at baseline, during trial SCS lead placement, as well as 1 month and 3 months following permanent SCS implantation in chronic pain patients who received SCS treatment. Several QST measures were conducted, with specific focus on examination of dynamic models (central sensitization and conditioned pain modulation [CPM]) and their association with pain outcomes 3 months post SCS implantation. RESULTS: Results suggest few changes in QST over time. However, central sensitization and CPM at baseline were significantly associated with clinical pain at 3 months following SCS implantation, controlling for psycho/behavioral factors and pain at baseline. Specifically, enhanced central sensitization and reduced CPM were associated with less self-reported pain 3 months following SCS implantation. CONCLUSIONS: These findings suggest a potentially important role for dynamic pain assessment in individuals undergoing SCS, and hint at potential mechanisms through which SCS may impart its benefit.

Improving patient experience with spinal cord stimulation: implications of position-related changes in neurostimulation.

OBJECTIVES: The objective of this narrative review is to discuss the clinical implications of position-related changes in spinal cord stimulation and technological improvements to better meet patient needs. METHODS: Keywords applicable to spinal cord stimulation therapy, including paresthesia perception, spinal cord position, lead impedance, and sensor technologies, were searched in the PubMed, EMBASE, and Cochrane Library databases. Literature analysis, combined with extensive clinical experience with spinal cord stimulation therapy, forms the basis of this review. RESULTS: Fluctuations in paresthesia perception are largely caused by variation in the distance between the fixed electrodes and the spinal cord consequent to patient movement. Patients employ multiple strategies with varying success to manage position-related fluctuations in stimulation perception, which may result in suboptimum therapy delivery. CONCLUSIONS: A new type of spinal cord stimulation system that incorporates accelerometer technology to automatically adjust stimulation amplitude based on patient position may better meet patient analgesic needs and is in early clinical application.

Long-term outcomes of spinal cord stimulation with percutaneously introduced paddle leads in the treatment of failed back surgery syndrome and lumboischialgia.

OBJECTIVE: The study aims to evaluate the long-term clinical and technical efficacy of recently developed percutaneously introducible plate electrodes for spinal cord stimulation. METHODS: Twenty-one patients diagnosed with failed back surgery syndrome (FBSS) or lumboischialgia were implanted with a small profile plate-type electrode. Patients were followed-up long term and were asked at baseline, after trial, and during each follow-up visit to score their pain on a visual analog scale (VAS) for pain now, worst pain last week, least pain last week, and mean pain last week. Pain location, electrophysiologic parameters, and number of reprogrammings were collected as well. Furthermore, each patient was asked if he/she would redo the procedure post trial and at each of the follow-up visits. RESULTS: A total of 21 patients were prospectively followed up long term. With a mean follow-up of 40.8 months, a significant mean reduction in patient self-reported pain from baseline to postoperative of 75.79% pain reduction was seen at follow-up 1 and 62.52% at follow-up 2. A significant decrease was obtained for, respectively, pain at the present moment, VAS pain worst last week, VAS pain least last week, and VAS pain mean last week in comparison with baseline VAS scores. All patients indicated that they would redo the procedure. CONCLUSION: Percutaneous implantation of small profile paddle leads in patients with FBSS and lumboischialgia produces favorable results over the long term that are at least comparable with surgical implanted paddle leads. The percutaneous approach also allows nonsurgically trained pain physicians to introduce paddle leads. Indices like if patients would redo the procedure may be more appropriate for analyzing long-term outcomes than the arbitrarily taking 50% reduction in VAS scores.

Psychological screening/phenotyping as predictors for spinal cord stimulation.

Spinal cord stimulation (SCS) is becoming a widely used treatment for a number of pain conditions and is frequently considered as a pain management option when conservative or less invasive techniques have proven to be ineffective. Potential indications for SCS include complex regional pain syndrome (CRPS), postherpetic neuralgia, traumatic nerve injury, failed back surgery syndrome, refractory angina pectoris, peripheral vascular disease, neuropathic pain, and visceral pain (Guttman et al. Pain Pract. 9:308-11, 2009). While research on SCS is in its infancy, it is clear that substantial variation exists in the degree of benefit obtained from SCS, and the procedure does not come without risks; thus focused patient selection is becoming very important. Psychological characteristics play an important role in shaping individual differences in the pain experience and may influence responses to SCS, as well as a variety of other pain treatments (Doleys Neurosurg Focus 21:E1, 2006). In addition to psychological assessment, quantitative sensory testing (QST) procedures offer another valuable resource in forecasting who may benefit most from SCS and may also shed light on mechanisms underlying the individual characteristics promoting the effectiveness of such procedures (Eisenberg et al. Pain Pract. 6:161-165, 2006). Here, we present a brief overview of recent studies examining these factors in their relationship with SCS outcomes.

Qualitative exploration of psychological factors associated with spinal cord stimulation outcome.

BACKGROUND AND AIM: Spinal cord stimulation (SCS) is a last resort treatment for chronic pain consisting of an implantable pulse generator connected to leads placed in the epidural space of the spinal cord. Effective in reducing chronic pain, however, efficacy has been found to decrease over time. Psychological factors affecting outcome of SCS have been investigated through quantitative methods, but these have failed to provide confident predictors. We aimed to investigate via a qualitative approach, the experience of SCS following 1 year of therapy. METHODS: Thirteen chronic non-cancer pain participants were interviewed. All participants had been trialled with SCS. The majority had gone on to full implantation with varying degrees of pain relief. Thematic analysis was employed to analyse the data from the interviews. RESULTS: Interviews resulted in findings that previous quantitative studies had failed to uncover. Two emergent core themes surfaced: 'coping with pain' and 'SCS treatment'. The effect of emotion upon coping was recurrent. Participants divided the SCS experience into information provision, independence and unexpected experiences. CONCLUSION: The findings provide context for the patients' experience of SCS. This research suggests that improved preparation prior to SCS including information provision, CBT and contact with expert patients may be of value.