Rise of multiattribute decision-making in combating COVID-19: A systematic review of the state-of-the-art literature.

Considering the coronavirus disease 2019 (COVID-19) pandemic, the government and health sectors are incapable of making fast and reliable decisions, particularly given the various effects of decisions on different contexts or countries across multiple sectors. Therefore, leaders often seek decision support approaches to assist them in such scenarios. The most common decision support approach used in this regard is multiattribute decision-making (MADM). MADM can assist in enforcing the most ideal decision in the best way possible when fed with the appropriate evaluation criteria and aspects. MADM also has been of great aid to practitioners during the COVID-19 pandemic. Moreover, MADM shows resilience in mitigating consequences in health sectors and other fields. Therefore, this study aims to analyse the rise of MADM techniques in combating COVID-19 by presenting a systematic literature review of the state-of-the-art COVID-19 applications. Articles on related topics were searched in four major databases, namely, Web of Science, IEEE Xplore, ScienceDirect, and Scopus, from the beginning of the pandemic in 2019 to April 2021. Articles were selected on the basis of the inclusion and exclusion criteria for the identified systematic review protocol, and a total of 51 articles were obtained after screening and filtering. All these articles were formed into a coherent taxonomy to describe the corresponding current standpoints in the literature. This taxonomy was drawn on the basis of four major categories, namely, medical (n = 30), social (n = 4), economic (n = 13) and technological (n = 4). Deep analysis for each category was performed in terms of several aspects, including issues and challenges encountered, contributions, data set, evaluation criteria, MADM techniques, evaluation and validation and bibliography analysis. This study emphasised the current standpoint and opportunities for MADM in the midst of the COVID-19 pandemic and promoted additional efforts towards understanding and providing new potential future directions to fulfil the needs of this study field.

Spinal Cord Stimulation vs Conventional Therapies for the Treatment of Chronic Low Back and Leg Pain: A Systematic Review of Health Care Resource Utilization and Outcomes in the Last Decade.

OBJECTIVE: The purpose of this review is to critically appraise the literature for evidence supporting the health care resource utilization and cost-effectiveness of spinal cord stimulation (SCS) compared with conventional therapies (CTs) for chronic low back and leg pain. METHODS: The PubMed, MEDLINE, Embase, CINAHL, and Rehabilitation & Sports Medicine databases were searched for studies published from January 2008 through October 2018, using the following MeSH terms: "spinal cord stimulation," "chronic pain," "back pain," "patient readmission," "economics," and "costs and cost analysis." Additional sources were added based on bibliographies and consultation with experts. The following data were extracted and analyzed: demographic information, study design, objectives, sample sizes, outcome measures, SCS indications, complications, costs, readmissions, and resource utilization data. RESULTS: Of 204 studies screened, 11 studies met inclusion criteria, representing 31,439 SCS patients and 299,182 CT patients. The mean age was 53.5 years for SCS and 55.6 years for CT. In eight of 11 studies, SCS was associated with favorable outcomes and found to be more cost-effective than CT for chronic low back pain. Compared with CT, SCS resulted in shorter hospital stays and lower complication rates and health care costs at 90 days. SCS was associated with significant improvement in health-related quality of life, health status, and quality-adjusted life-years. CONCLUSIONS: For the treatment of chronic low back and leg pain, the majority of studies are of fair quality, with level 3 or 4 evidence in support of SCS as potentially more cost-effective than CT, with less resource expenditure but higher complication rates. SCS therapy may yet play a role in mitigating the financial burden associated with chronic low back and leg pain.

Ultrasmall Superparamagnetic Iron Oxide Imaging Identifies Tissue and Nerve Inflammation in Pain Conditions.

Objective: Correlation between radiologic structural abnormalities and clinical symptoms in low back pain patients is poor. There is an unmet clinical need to image inflammation in pain conditions to aid diagnosis and guide treatment. Ferumoxytol, an ultrasmall superparamagnetic iron oxide (USPIO) nanoparticle, is clinically used to treat iron deficiency anemia and showed promise in imaging tissue inflammation in human. We explored whether ferumoxytol can be used to identify tissue and nerve inflammation in pain conditions in animals and humans. Methods: Complete Freud's adjuvant (CFA) or saline was injected into mice hind paws to establish an inflammatory pain model. Ferumoxytol (20 mg/kg) was injected intravenously. Magnetic resonance imaging (MRI) was performed prior to injection and 72 hours postinjection. The changes in the transverse relaxation time (T2) before and after ferumoxytol injection were compared between mice that received CFA vs saline injection. In the human study, we administered ferumoxytol (4 mg/kg) to a human subject with clinical symptoms of lumbar radiculopathy and compared the patient with a healthy subject. Results: Mice that received CFA exhibited tissue inflammation and pain behaviors. The changes in T2 before and after ferumoxytol injection were significantly higher in mice that received CFA vs saline (20.8 ± 3.6 vs 2.2 ± 2.5, P = 0.005). In the human study, ferumoxytol-enhanced MRI identified the nerve root corresponding to the patient's symptoms, but the nerve root was not impinged by structural abnormalities, suggesting the potential superiority of this approach over conventional structural imaging techniques. Conclusions: Ferumoxytol-enhanced MRI can identify tissue and nerve inflammation and may provide a promising diagnostic tool in assessing pain conditions in humans.

Neuropathic Pain Medication Use Does Not Alter Outcomes of Spinal Cord Stimulation for Lower Extremity Pain.

INTRODUCTION: Spinal cord stimulation (SCS) for the treatment of lower extremity pain is believed to the result of increased activity in the descending inhibitory and decreased activity in the ascending excitatory tracts. Evidence suggests that the analgesia afforded by SCS may be altered using certain neuropathic pain medications that also modulate neurotransmitters in these sensory tracts. We hypothesize that neuropathic pain medications may alter the response to SCS therapy. METHODS: One hundred and fifteen subjects undergoing SCS therapy for lower extremity pain were retrospectively examined. The pharmacologic profile, including stable use of neuropathic and opioid medications, were recorded. Three separate logistic regression models examined the odds ratio of primary outcomes; a successful SCS trial, a 50% decrease in pain or a 50% reduction in opioid use one year after implant. RESULTS: Neither the use of opioids or neuropathic pain medications were associated with changes in the odds of a successful SCS trial or a 50% pain reduction. A higher dose of chronic opioids use prior to a trial was associated with greater odds of having a 50% reduction in opioid use following implant. OR 1.02, 95% CI 1.01-1.02, p-value < 0.01). CONCLUSIONS: The use of neuropathic pain medications did not change the odds of either a successful SCS trial, or of experiencing a 50% reduction in pain at one year. The association between higher opioid doses and greater odds of a 50% reduction in opioid use may be the reflective of SCS's ability to reduce opioid reliance in chronic pain patients.

Thermal QST Phenotypes Associated with Response to Lumbar Epidural Steroid Injections: A Pilot Study.

OBJECTIVE: Response to lumbar epidural steroid injection in lumbar radicular pain varies. The purpose of this study is to characterize the changes in quantitative sensory testing (QST) phenotypes of subjects and compare the QST characteristics in patients who do respond to treatment of radicular pain with a lumbar epidural steroid injection (ESI). DESIGN: Prospective, observational pilot study. SETTING: Outpatient pain center. METHODS: Twenty subjects with a lower extremity (LE) radicular pain who were scheduled to have an ESI were recruited. At the visit prior to and four weeks following an ESI, subjects underwent QST measurements of both the affected LE and the contralateral unaffected UE. RESULTS: Following an ESI, nine subjects reported a greater than 30% reduction in radicular pain and 11 reported a less than 30% reduction in radicular pain. Subjects who had less than 30% pain reduction response (nonresponders) to an ESI had increased pre-injection warm sensation threshold (37.30 °C, SD = 2.51 vs 40.39, SD = 3.36, P = 0.03) and heat pain threshold (47.22 °C, SD = 1.38, vs 48.83 °C, SD = 2.10, P = 0.04). Further, the nonresponders also showed increased pre-injection warm sensation threshold as measured in the difference of warm sensation detection threshold difference in the affected limb and the unaffected arm (2.68 °C, SD = 2.92 vs 5.67 °C, SD = 3.22, P = 0.045). Other QST parameters were not affected. CONCLUSIONS: The results show that the nonresponders to ESIs have increased detection threshold to heat pain and warm sensation, suggesting that a preexisting dysfunction in the C fibers in this group of subjects who can be detected by QST. Such altered QST characteristics may prognosticate the response to ESIs.

High-Frequency Spinal Cord Stimulation for Chronic Pain: Pre-Clinical Overview and Systematic Review of Controlled Trials.

OBJECTIVE: To assess the evidence base for high-frequency spinal cord stimulation (HFSCS). HFSCS has the potential to provide paresthesia-free pain relief for patients with chronic pain, in contrast to conventional spinal cord stimulation, which produces distracting and potentially unpleasant paresthesias. DESIGN: A systematic review following standard methodological guidelines (Prospero #CRD42015029215). METHODS: We searched PubMed to March 14, 2016 without language restriction and hand-checked reference lists. Two authors independently performed study selection, bias evaluations, and data extraction. The pre-clinical review selected studies focusing on the mechanism and non-human experience with HFSCS. Clinically, any prospective study of adults using HFSCS (≥ 1000 Hz) was included. RESULTS: Pre-clinical studies have characterized many aspects underlying the mechanism of HFSCS. For the clinical systematic review, eight trials (236 participants randomized or 160 followed prospectively) met inclusion criteria. All trials of HFSCS focused on patients with chronic low back pain with one exception, which included patients with chronic migraine. All but one trial documented funding by industry. Performance bias due to unmasked participants, physicians, and outcome assessors limited the quality of all but one study. CONCLUSIONS: Significant growth in the preclinical and clinical evidence base for HFSCS suggests that HFSCS may differ from conventional SCS in mechanism of action and efficacy of treatment, respectively. Addressing current knowledge gaps in clinical evidence will require standardization in trial reporting and leveraging the paresthesia-free characteristic of HFSCS to enable masking in high-quality randomized controlled trials.

Profiles of Urine Drug Test in Clinical Pain Patients vs Pain Research Study Subjects.

OBJECTIVE: To examine similarities and differences in urine drug test (UDT) results in clinical pain patients and pain subjects participating in pain research studies. DESIGN: An observational study with retrospective chart review and data analysis. METHODS: We analyzed 1,874 UDT results obtained from 1) clinical pain patients (Clinical Group; n = 1,529) and 2) pain subjects consented to participate in pain research studies (Research Group; n = 345). Since several medications such as opioids used in pain management are drugs of abuse (DOA) and can result in a positive UDT, we specifically identified those cases of positive UDT due to nonprescribed DOA and designated these cases as positive UDT with DOA (PUD). RESULTS: We found that 1) there was a higher rate of PUD in clinical pain patients (41.3%) than in pain research study subjects (14.8%); 2) although subjects in the Research Group were informed ahead of time that UDT will be conducted as a screening test, a substantial number (14.8%) of pain research study subjects still showed PUD; 3) there were different types of DOA between clinical pain patients (cannabinoids as the top DOA) and research study subjects (cocaine as the top DOA); and 4) a common factor associated with PUD was opioid therapy in both Clinical Group and Research Group. CONCLUSION: These results support previous findings that PUD is a common finding in clinical pain patients, particularly in those prescribed opioid therapy, and we suggest that UDT be used as routine screening testing in pain research studies.

Effect of 1.5% Topical Diclofenac on Clinical Neuropathic Pain.

BACKGROUND: Neuropathic pain is a condition resulting from injury to the peripheral and/or central nervous system. Despite extensive research over the last several decades, neuropathic pain remains difficult to manage. METHODS: The authors conducted a randomized, placebo-controlled, double-blinded, and crossover clinical trial to examine the effect of 1.5% topical diclofenac (TD) on neuropathic pain. The authors hypothesized that 1.5% TD would reduce the visual pain score and improve both quantitative sensory testing and functional status in subjects with neuropathic pain. The authors recruited subjects with postherpetic neuralgia and complex regional pain syndrome. The primary outcome was subject's visual pain score. RESULTS: Twenty-eight subjects completed the study (12 male and 16 female) with the mean age of 48.8 yr. After 2 weeks of topical application, subjects in 1.5% TD group showed lower overall visual pain score compared with placebo group (4.9 [1.9] vs. 5.6 [2.1], difference: 0.8; 95% CI, 0.1 to 1.3; P = 0.04) as well as decreased burning pain (2.9 [2.6] vs. 4.3 [2.8], difference, 1.4; 95% CI, 0.2 to 2.6; P = 0.01). There were no statistical differences in constant pain, shooting pain, or hypersensitivity over the painful area between the groups. This self-reported improvement of pain was corroborated by the decreased pain summation detected by quantitative sensory testing. There were no statistically significant changes in functional status in these subjects. There were no complications in both groups. CONCLUSION: The findings indicate that 1.5% TD may serve as an effective treatment option for patients with neuropathic pain from postherpetic neuralgia and complex regional pain syndrome.

Cervical epidural blood patch--A literature review.

OBJECTIVE: Epidural blood patches (EBP) are rarely performed at the cervical levels, primarily due to fear of neurological complications such as spinal cord compression. We reviewed the literature to provide an evidence-based review of performance of cervical EBPs, with a specific focus on indication, technique, safety, and efficacy. DESIGN: A comprehensive electronic literature search was done to include studies that reported on performance of cervical EBPs in patients with CSF leak at the cervical level. Data regarding indication, level of CSF leak, level of cervical EBP, volume of blood used, efficacy, and complications were collected. RESULTS: A total of 15 studies, reporting on 19 patients were included. All patients presented with a headache that increased in the standing position, and improved in the supine position. All patients were identified to have a CSF leak at the cervical level. Eight patients first underwent a lumbar EBP, without complete, long-term relief. All these patients, along with 11 patients who did not undergo a lumbar EPB prior to cervical EBP, reported complete, long-term pain relief. EBPs were mostly done in the prone position, using imaging guidance. An average of 5-8 mL of autologous blood was injected in the epidural space. No major neurological complications were reported in any patient. CONCLUSION: The review suggests that cervical EBP can be performed for cervical CSF leaks associated with positional headache without a significant risk of serious adverse events. CLASSIFICATION OF EVIDENCE: Our review provides Class II level of evidence that cervical EBPs are safe and effective in reliving positional headache due to CSF leak.

Increased pain sensitivity in chronic pain subjects on opioid therapy: a cross-sectional study using quantitative sensory testing.

OBJECTIVE: The aim of this study was to compare the sensitivity to experimental pain of chronic pain patients on opioid therapy vs chronic pain patients on non-opioid therapy and healthy subjects by quantitative sensory testing (QST). SETTING: There is a growing body of evidence demonstrating that chronic use of opioid drugs may alter pain sensitivity. Identifying the characteristic changes in thermal pain sensitivity in chronic opioid users will be helpful in diagnosing pain sensitivity alterations associated with chronic opioid use. METHODS: Utilizing an office-based QST technique, we examined thermal pain threshold, tolerance, and temporal summation in 172 chronic pain subjects receiving opioid therapy, 121 chronic pain subjects receiving non-opioid therapy, and 129 healthy subjects. RESULTS: In chronic pain subjects receiving opioid therapy, there were detectable differences in QST characteristics compared with both chronic pain subjects receiving non-opioid therapy and healthy subjects. Specifically, in chronic pain subjects receiving opioid therapy, 1) sensitivity to heat pain was increased; threshold to heat pain was significantly lower; 2) tolerance to supra-threshold heat pain was significantly decreased; and 3) temporal pain summation was exacerbated, as compared with chronic pain subjects receiving non-opioid therapy. In a subgroup of chronic pain subjects receiving opioid therapy with increased heat pain sensitivity, their average opioid medication dosage was significantly higher than those who had an above-average heat pain threshold. Moreover, a subset of chronic pain subjects on opioid therapy exhibited a significant decrease in diffuse noxious inhibitory control (DNIC) compared with chronic pain subjects on non-opioid therapy. CONCLUSION: These findings suggest that a subset of QST parameters can reflect opioid-associated thermal pain sensitivity alteration, including decreased heat pain threshold, decreased cold and heat pain tolerance, diminished DNIC, and/or exacerbated temporal summation.

Diagnosis and treatment of posterior sacroiliac complex pain: a systematic review with comprehensive analysis of the published data.

OBJECTIVE: To assess the evidence on the validity of sacral lateral branch blocks and the effectiveness of sacral lateral branch thermal radiofrequency neurotomy in managing sacroiliac complex pain. DESIGN: Systematic review with comprehensive analysis of all published data. INTERVENTIONS: Six reviewers searched the literature on sacral lateral branch interventions. Each assessed the methodologies of studies found and the quality of the evidence presented. OUTCOME MEASURES: The outcomes assessed were diagnostic validity and effectiveness of treatment for sacroiliac complex pain. The evidence found was appraised in accordance with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system of evaluating scientific evidence. RESULTS: The searches yielded two primary publications on sacral lateral branch blocks and 15 studies of the effectiveness of sacral lateral branch thermal radiofrequency neurotomy. One study showed multisite, multidepth sacral lateral branch blocks can anesthetize the posterior sacroiliac ligaments. Therapeutic studies show sacral lateral branch thermal radiofrequency neurotomy can relieve sacroiliac complex pain to some extent. The evidence of the validity of these blocks and the effectiveness of this treatment were rated as moderate in accordance with the GRADE system. CONCLUSIONS: The literature on sacral lateral branch interventions is sparse. One study demonstrates the face validity of multisite, multidepth sacral lateral branch blocks for diagnosis of posterior sacroiliac complex pain. Some evidence of moderate quality exists on therapeutic procedures, but it is insufficient to determine the indications and effectiveness of sacral lateral branch thermal radiofrequency neurotomy, and more research is required.

Effects of Spinal Cord Stimulation on Pain Thresholds and Sensory Perceptions in Chronic Pain Patients.

OBJECTIVE: Spinal cord stimulation (SCS) has been in clinical use for nearly four decades. In earliest observations, researchers found a significant increase in pain threshold during SCS therapy without changes associated with touch, position, and vibration sensation. Subsequent studies yielded diverse results regarding how SCS impacts pain and other sensory thresholds. This pilot study uses quantitative sensory testing (QST) to objectively quantify the impact of SCS on warm sensation, heat pain threshold, and heat pain tolerance. MATERIALS AND METHODS: Nineteen subjects with an indwelling SCS device for chronic pain were subjected to QST with heat stimuli. QST was performed on an area of pain covered with SCS-induced paresthesia and an area without pain and without paresthesia, while the SCS was turned off and on. The temperature at which the patient detected warm sensation, heat pain, and maximal tolerable heat pain was used to define the thresholds. RESULTS: We found that all three parameters, the detection of warm sensation, heat pain threshold, and heat pain tolerance, were increased during the period when SCS was on compared with when it was off. This increase was observed in both painful and non-painful sites. CONCLUSION: The observed pain relief during SCS therapy seems to be related to its impact on increased sensory threshold as detected in this study. The increased sensory threshold on areas without pain and without the presence of SCS coverage may indicate a central (spinal and/or supra-spinal) influence from SCS.

tRF-BERT: A transformative approach to aspect-based sentiment analysis in the bengali language.

In recent years, the surge in reviews and comments on newspapers and social media has made sentiment analysis a focal point of interest for researchers. Sentiment analysis is also gaining popularity in the Bengali language. However, Aspect-Based Sentiment Analysis is considered a difficult task in the Bengali language due to the shortage of perfectly labeled datasets and the complex variations in the Bengali language. This study used two open-source benchmark datasets of the Bengali language, Cricket, and Restaurant, for our Aspect-Based Sentiment Analysis task. The original work was based on the Random Forest, Support Vector Machine, K-Nearest Neighbors, and Convolutional Neural Network models. In this work, we used the Bidirectional Encoder Representations from Transformers, the Robustly Optimized BERT Approach, and our proposed hybrid transformative Random Forest and Bidirectional Encoder Representations from Transformers (tRF-BERT) models to compare the results with the existing work. After comparing the results, we can clearly see that all the models used in our work achieved better results than any of the previous works on the same dataset. Amongst them, our proposed transformative Random Forest and Bidirectional Encoder Representations from Transformers achieved the highest F1 score and accuracy. The accuracy and F1 score of aspect detection for the Cricket dataset were 0.89 and 0.85, respectively, and for the Restaurant dataset were 0.92 and 0.89 respectively.

Metastatic Prostate Cancers with BRCA2 versus ATM Mutations Exhibit Divergent Molecular Features and Clinical Outcomes.

PURPOSE: In patients with metastatic prostate cancer (mPC), ATM and BRCA2 mutations dictate differences in PARPi inhibitor response and other therapies. We interrogated the molecular features of ATM- and BRCA2-mutated mPC to explain the divergent clinical outcomes and inform future treatment decisions. EXPERIMENTAL DESIGN: We examined a novel set of 1,187 mPCs after excluding microsatellite-instable (MSI) tumors. We stratified these based on ATM (n = 88) or BRCA2 (n = 98) mutations. As control groups, mPCs with mutations in 12 other homologous recombination repair (HRR) genes were considered non-BRCA2/ATM HRR-deficient (HRDother, n = 193), whereas lack of any HRR mutations were considered HRR-proficient (HRP; n = 808). Gene expression analyses were performed using Limma. Real-world overall survival was determined from insurance claims data. RESULTS: In noncastrate mPCs, only BRCA2-mutated mPCs exhibited worse clinical outcomes to AR-targeted therapies. In castrate mPCs, both ATM and BRCA2 mutations exhibited worse clinical outcomes to AR-targeted therapies. ATM-mutated mPCs had reduced TP53 mutations and harbored coamplification of 11q13 genes, including CCND1 and genes in the FGF family. BRCA2-mutated tumors showed elevated genomic loss-of-heterozygosity scores and were often tumor mutational burden high. BRCA2-mutated mPCs had upregulation of cell-cycle genes and were enriched in cell-cycle signaling programs. This was distinct from ATM-mutated tumors. CONCLUSIONS: Tumoral ATM and BRCA2 mutations are associated with differential clinical outcomes when patients are stratified by treatments, including hormonal or taxane therapies. ATM- and BRCA2-mutated tumors exhibited differences in co-occurring molecular features. These unique molecular features may inform therapeutic decisions and development of novel therapies.

A Complex Regional Pain Syndrome Imaging Journal: Case Report.

Complex regional pain syndrome (CRPS) poses a diagnostic and management challenge for many clinicians, particularly when disease symptomatology waxes and wanes. Monitoring symptom variations with digital and infrared thermal images allows for more accurate evaluation of disease progression overtime. We present the case of a patient who developed CRPS and catalog his symptoms using a digital and infrared thermal imaging diary. The images were instrumental toward establishing the initial diagnosis of CRPS, monitoring disease progression, and assessing response to treatment. We discuss the present understanding of infrared thermography in CRPS and advocate for its routine use at the beside.

Epidural blood patch for postdural puncture positional vertigo.

STUDY DESIGN: Case report. OBJECTIVE: To report an unusual case of refractory positional vertigo without headache that developed after the placement of an epidural catheter for postoperative pain and that was treated with an epidural blood patch. SUMMARY OF THE BACKGROUND DATA: Although it is common practice to use epidural blood patch (EBP) to treat positional headache from postdural puncture (PDP), the literature is limited to one letter to the editor describing PDP positional vertigo treated with EBP. METHODS: Description of a clinical case. RESULTS: Here we present a case where the patient presented with the complaint of vertigo without headache and had a characteristic onset with upright position and marked relief when lying down. The patient received an EBP with complete resolution of her symptoms. CONCLUSIONS: This case illustrates patient can present with an isolated symptom such as dizziness without headache after PDP. The patient received an EBP with complete resolution of her symptom of postdural dizziness.

Comparison between acupuncture therapy and gabapentin for chronic pain: a pilot study.

BACKGROUND: We examined whether the effect of true electroacupuncture on pain and functionality in chronic pain participants can be differentiated from that of medication (gabapentin) by analyzing quantitative sensory testing (QST). METHODS: We recruited chronic back and neck pain participants who received six sessions (twice weekly) of true electroacupuncture versus sham electroacupuncture or 3 weeks of gabapentin versus placebo treatment. QST profiles, pain scores, and functionality profile were obtained at baseline (visit 1) and after three sessions (visit 4) or six sessions (visit 7) of acupuncture or 3 weeks of gabapentin or placebo. RESULTS: A total of 50 participants were analyzed. We found no differences in QST profile changes (p = 0.892), pain reduction (p = 0.222), or functionality (p = 0.254) between the four groups. A major limitation of this pilot study was the limited number of study participants in each group. CONCLUSION: This pilot study suggests that a large-scale clinical study with an adequate sample size would be warranted to compare acupuncture and medication therapy for chronic pain management. TRIAL REGISTRATION NUMBER: NCT01678586 (ClinicalTrials.gov).

Fantastic Four: Age, Spinal Cord Stimulator Waveform, Pain Localization and History of Spine Surgery Influence the Odds of Successful Spinal Cord Stimulator Trial.

BACKGROUND: There is a dearth in our understanding of the factors that are predictive of successful spinal cord stimulator (SCS) trials and eventual conversion to permanent implants. Knowledge of these factors is important for appropriate patient selection and treatment optimization. OBJECTIVES: Although previous studies have explored factors predictive of trial success, few have examined the role of waveform in trial outcomes. This study sought to establish the relationship of neuraxial waveform and related measures to trial outcomes. STUDY DESIGN: This study used a retrospective chart review design. METHODS: Data were retrospectively collected on 174 patients undergoing SCS trials upon institutional review board approval of the study protocol. Indications for SCS were: complex regional pain syndrome, failed back surgery syndrome with radicular symptoms, peripheral neuropathy, and axial low back pain. Descriptive statistics and logistic regression analyses were used to assess the association of demographic and clinical variables with SCS trial outcomes. RESULTS: The study population comprised 56% women, had a median age of 55 (interquartile range [IQR], 44-64), and 32 of 174 (18%) patients failed SCS trials. Individuals with successful trials (>= 50% pain relief) were significantly younger and had a median age of 54 years (IQR, 42-60) compared to those who failed SCS trials (median age 66 years; IQR, 50-76; P = .005). Adjusting for age, gender, number of leads, pain category, and diagnoses: surgical history (odds ratio [OR] = 4.4; 95% confidence interval [CI], 1.3-15.8) and paresthesia-based tonic-stimulation (OR = 10.3; 95% CI, 1.7-62.0), but not burst or high frequency, were significantly associated with successful trials. Of note, the number of leads (whether dual or single), pain duration, characteristics, and category (nociceptive vs neuropathic) were not significant factors. An interaction between surgical spine history and lower extremity pain was significantly associated with a positive trial (P = .005). LIMITATIONS: This study was limited by its retrospective nature and focus on a patient population at a single major academic medical center. CONCLUSIONS: Paresthesia-based tonic stimulation, age, and surgical history have significant effects on SCS trials. Prospective and randomized controlled studies may provide deeper insights regarding impact on costs and overall outcomes.IRB Approval #: 2018P002216. KEY WORDS: Pain duration, pain location, spinal cord stimulator trial, stimulator waveform, surgical history.