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In the article, the authors discuss the clinical and pathophysiological aspects of spinal cord stimulation (SCS) as a pain management strategy by citing the case of 11 patients with nonpathological spinal cord. Also cited are the use of epidural electrodes in SCS to electrically modulate the circuitry in the spinal cord, and the potential autonomic side effects of SCS.

Background: Failed back surgery syndrome (FBSS) is a constellation of conditions that describes persistent or recurring low back pain following spine surgeries with a reported point prevalence in the general adult population of 37% and a lifetime prevalence of between 60% and 85%. It always has a significant impact on patients' quality of life. Neuromodulation such as spinal cord stimulation has been showing significant effect and improvement in pain scores and functional capacity of the FBSS patients with a reflected effect on their daily activities and quality of life. Aim and Objectives: Our aim in this study is to assess the change in pain scores, quality of life and opioid medications intake as an outcome of neuromodulation procedures performed to patients diagnosed with failed back surgery syndrome, and to detect the post procedure complications. Subjects and Methods: This is a mixed prospective-retrospective study conducted at Ain Shams University (ASU) hospital and Oregon Health and Science University (OHSU) hospital during the period from September 2019 till December 2022. Patients who are 18 years old or older diagnosed with FBSS for more than 6 months and treated with spinal cord stimulation with successful trials during this time frame were included in the study. Results: 34 patients were included in this study who had successful SCS trials and underwent a permanent implantation of SCS devices with post procedure follow up period of 12 months. Patients showed median pain numerical rating scale (NRS) of 7/10 at baseline with median NRS of 4/10 through the follow up period, also, there was a significant improvement of functional capacity using metabolic equivalent assessment with 74% of patients became moderate capacity compared to 32% at baseline. Quality of life assessed by activity measure of post-acute care (AM-PAC) showed significant improvement from mean of 16.87 6 2.74 at baseline to mean of 19.97 6 2.93 through follow up. Also there was a significant reduction of opioid medication usage. Post procedure complications was of low percentage with the most commonly detected were battery dysfunction in 7 patients and pocket pain in 6 patients. Reoperation was needed in 13 patients with 4 needed just revision and 9 patients required a complete removal of the device. Conclusion: Failed back surgery syndrome is a widely described chronic pain condition which has a negative impact on the patients' quality of life and daily activities with an evidenced effect on chronic use and abuse of opioid analgesic medications. We presented in our study that SCS could be offered as an effective modality of treatment with a statistically significant reduction in pain scores and a significant improvement in functional capacity and quality of life. Also, it has a recognizable but not statistically significant reduction in opioid analgesic medications and a very low percentage of procedure related complications. [ABSTRACT FROM AUTHOR]

Failed back surgery syndrome is defined as increased or persistent pain following spinal surgery. Despite a relatively high incidence of failed back surgery syndrome (20%), patients may not be counselled regarding this complication pre-operatively. The Academy of Medical Royal Colleges has provided the Benefits, Risks, Alternatives and doing Nothing Toolkit to guide clinical discussions during the consent process. A 46-year-old female experiencing chronic lower back pain since 2003 suffered an exacerbation in 2015. Imaging identified non-compressive disc bulges. She was not put through the low back pain pathway as recommended by NICE and underwent spinal fusion in 2017. She continues to experience severe pain 54 months postsurgery. When considering spinal surgery, the risk of failed back surgery syndrome should be discussed with patients. Both clinicians and patients can use the BRAN toolkit to ensure open and transparent discussion prior to any intervention. [ABSTRACT FROM AUTHOR]

Objective Generator site pain is a relatively common phenomenon in patients undergoing spinal cord stimulation (SCS) that complicates management and effective pain relief. This pain may be managed conservatively, with repositioning of the battery and, in some cases, with explant. Here we explore our experience with management of generator site pain ("pocket pain") in a large single-center study. Methods All SCS permanent implants and implantable pulse generator (IPG) placements over 9 years were reviewed. Of 785 cases, we identified 43 patients with pocket pain (5.5%). Demographics and treatments of the pocket pain cohort were analyzed. Results The mean age (± SEM) of the pocket pain cohort was 46.86 ± 1.06, and there were 10/33 males/females. Females were overrepresented in pocket pain cohort (76.7%) when compared with the total SCS cohort (59.0%) (X2 = 5.93, P  = 0.015). Diagnosis included failed back surgery syndrome (51.2%), complex regional pain syndrome (23.3%), and chronic neuropathic pain (25.5%). No patients improved with conservative therapy. All patients either went on to revision (n  = 23) or explant (n  = 20). Time from initial surgery to development of pocket pain was 7.5 months (range: 0.3–88) and from pocket pain to revision surgery was 4.5 months (range: 0.4–26). In addition, significantly more pocket pain patients (65.1%) had workers' compensation (WC) insurance compared with patients without pocket pain (24.9%) (X2 = 33.3, P  < 0.001). Conclusion In our institutional experience, pocket pain was inadequately managed with conservative treatments. Being female and having SCS filed under WC increased risk of pocket pain. Future work will explore the nuances in device placement based on body shape and manual activity responsibilities. [ABSTRACT FROM AUTHOR]

Objective For many medical professionals dealing with patients with persistent pain following spine surgery, the term Failed back surgery syndrome (FBSS) as a diagnostic label is inadequate, misleading, and potentially troublesome. It misrepresents causation. Alternative terms have been suggested, but none has replaced FBSS. The International Association for the Study of Pain (IASP) published a revised classification of chronic pain, as part of the new International Classification of Diseases (ICD-11), which has been accepted by the World Health Organization (WHO). This includes the term Chronic pain after spinal surgery (CPSS), which is suggested as a replacement for FBSS. Methods This article provides arguments and rationale for a replacement definition. In order to propose a broadly applicable yet more precise and clinically informative term, an international group of experts was established. Results 14 candidate replacement terms were considered and ranked. The application of agreed criteria reduced this to a shortlist of four. A preferred option—Persistent spinal pain syndrome—was selected by a structured workshop and Delphi process. We provide rationale for using Persistent spinal pain syndrome and a schema for its incorporation into ICD-11. We propose the adoption of this term would strengthen the new ICD-11 classification. Conclusions This project is important to those in the fields of pain management, spine surgery, and neuromodulation, as well as patients labeled with FBSS. Through a shift in perspective, it could facilitate the application of the new ICD-11 classification and allow clearer discussion among medical professionals, industry, funding organizations, academia, and the legal profession. [ABSTRACT FROM AUTHOR]

Background Combining neuraxial opioids and local anesthetics in acute pain results in improved duration of analgesia and reduced dosages and adverse effects. Although commonly used in intrathecal drug delivery systems (IDDS) for chronic pain, the effectiveness of this admixture has not been examined specifically in relation to patient-controlled intrathecal analgesia (PCIA). Methods IDDS-implanted chronic noncancer pain patients receiving opioids with bupivacaine (O + B) were randomized to receive either opioids without bupivacaine (O) or O + B in a double-blind manner, at IDDS refills, for one week and then crossed over to the other solution for another week. Primary outcome measures included numeric rating scale (NRS) pain scores before and within 30 minutes after PCIA boluses. Secondary outcome measures included average NRS scores and functional outcome measures. Results Seventeen patients were enrolled, and 16 patients completed the study. There were no differences in NRS scores before and after PCIA boluses between the O and O + B conditions, though pain scores improved significantly (average decrease in NRS scores: O 1.81 ± 1.47 vs O + B 1.87 ± 1.40, P  =   0.688). No differences were noted in speed of onset or duration of analgesia. Although more patients subjectively preferred the O + B treatment, the difference was not statistically significant. No differences were noted in secondary outcome measures, with the exception of global impression of change having higher scores in O compared with O + B. Conclusions Acutely removing bupivacaine from a chronic intrathecal infusion of opioids and bupivacaine in patients with chronic noncancer pain did not adversely affect PCIA effectiveness, nor did it affect speed of onset or duration of effect. These findings are divergent from those in acute pain and may have to do with study conditions and pain phenotypes. [ABSTRACT FROM AUTHOR]

Objective Determine the effectiveness of spinal cord stimulation (SCS) for the treatment of axial low back pain (LBP) with or without leg pain. Design Systematic review. Subjects Persons aged ≥18 with axial LBP with or without accompanying leg pain. Intervention Traditional low-frequency, burst, or high-frequency SCS. Comparison Sham, active standard of care treatment, or none. Outcomes The primary outcome was ≥50% pain improvement, and the secondary outcome was functional improvement measured six or more months after treatment intervention. Methods Publications in PubMed, MEDLINE, and Cochrane databases were reviewed through September 19, 2019. Randomized or nonrandomized comparative studies and nonrandomized studies without internal controls were included. The Cochrane Risk of Bias Tool and GRADE system were used to assess individual study characteristics and overall quality. Results Query identified 262 publications; 17 were suitable for inclusion. For high-frequency SCS, the only level 1 study showed that 79% (95% confidence interval = 70–87%) of patients reported ≥50% pain improvement. For low-frequency SCS, the only level 1 study reported no categorical data for axial LBP-specific outcomes; axial LBP improved by a mean 14 mm on the visual analog scale at six months. Meta-analysis was not performed due to study heterogeneity. Conclusions According to GRADE, there is low-quality evidence that high-frequency SCS compared with low-frequency SCS is effective in patients with axial LBP with concomitant leg pain. There is very low-quality evidence for low-frequency SCS for the treatment of axial LBP in patients with concomitant leg pain. There is insufficient evidence addressing the effectiveness of burst SCS to apply a GRADE rating. [ABSTRACT FROM AUTHOR]

The article presents a case study related to 70-year-old male with a history of atrial fibrillation has anticoagulated with warfarin and chronic low back pain status post–L3-L5 laminectomy and fusion 3 years before presentation was referred to the pain clinic for assessment of ongoing chronic low back pain. Topics include the spinal cord stimulation has emerged as an impactful interventional modality has utilized to treat pain, and the pain physicians should be cognizant of the potential risks.

Objective Targeted intrathecal drug delivery (TIDD) is an effective interventional pain management modality often used in postlaminectomy patients with refractory chronic low back pain. A combination of intrathecal bupivacaine with an opioid is often used. However, intrathecal catheter tip granulomas have occurred with use of morphine or hydromorphone but generally not with fentanyl. The objective of this study was to compare the efficacy of TIDD using bupivacaine/fentanyl vs bupivacaine/hydromorphone in patients with chronic intractable low back pain postlaminectomy. Materials and Methods A retrospective comparative analysis of consecutive patients with lumbar postlaminectomy syndrome who were trialed and later received TIDD with a combination of bupivacaine/hydromorphone or bupivacaine/fentanyl between June 2009 and May 2016 at a single tertiary medical center. Results We identified a cohort of 58 lumbar postlaminectomy patients receiving a TIDD admixture of either hydromorphone/bupivacaine (30 patients) or low-dose fentanyl/bupivacaine (28 patients) with at least two years of follow-up. The fentanyl group had significantly lower baseline opioid consumption and a lower rate of intrathecal opioid dose escalation. Both groups had similar and significant reductions in pain scores over the two-year follow-up period. No granulomas were observed. Conclusion TIDD using a low-dose fentanyl admixture with bupivacaine in patients with postlaminectomy syndrome and refractory chronic low back pain results in similar pain relief to TIDD with hydromorphone and bupivacaine. Low-dose intrathecal fentanyl leads to a lower rate of opioid escalation and may be safer than hydromorphone. [ABSTRACT FROM AUTHOR]

Objective When evaluating sensory dysfunctions and pain mechanisms in patients with low back pain (LBP), a specific subgroup of patients with radicular symptoms is often excluded. Comparative studies that evaluate sensory sensitivity in patients with a dominant nociceptive and neuropathic pain component are rarely performed. Therefore, the goal of this study was to examine differences in electrical thresholds and conditioned pain modulation (CPM) between patients with low back–related leg pain (LBRLP) and patients with failed back surgery syndrome (FBSS). Design Cross-sectional study. Setting University Hospital Brussels. Subjects Twenty-one patients with LBRLP and 21 patients with FBSS were included. Methods Electrical detection thresholds (EDTs), electrical pain thresholds (EPTs), and CPM were evaluated on the symptomatic and nonsymptomatic sides. Within- and between-group differences were evaluated for all parameters. Results No between-group differences were found for EDT and EPT at both sides. On the nonsymptomatic side, a significantly lower CPM effect was found in the FBSS group (P  = 0.04). The only significant within-group difference was an increased EDT at the symptomatic side in patients with FBSS (P  = 0.01). Conclusions LBP patients with a primary neuropathic pain component revealed altered detection sensitivity at the symptomatic side, without severe indications for altered nociceptive processing, compared with LBP patients without a dominant neuropathic pain component. Endogenous modulation is functioning in LBP patients, although it is possible that it might only be functioning partially in patients with a dominant neuropathic pain component. [ABSTRACT FROM AUTHOR]

Objective Case reports and a case series have described relief of neuropathic pain (NP) after treatment with epidermal growth factor receptor inhibitors (EGFR-Is). These observations are supported by preclinical findings. The aim of this trial was to explore a potential clinical signal supporting the therapeutic efficacy of EGFR-Is in NP. Methods In a proof-of-concept trial using a randomized, double-blind, placebo-controlled design, 14 patients with severe, chronic, therapy-resistant NP due to compressed peripheral nerves or complex regional pain syndrome were randomized to receive a single infusion of the EGFR-I cetuximab and placebo in crossover design, followed by a single open-label cetuximab infusion. Results The mean reduction in daily average pain scores three to seven days after single-blinded cetuximab infusion was 1.73 points (90% confidence interval [CI] = 0.80 to 2.66), conferring a 1.22-point greater reduction than placebo (90% CI = –0.10 to 2.54). Exploratory analyses suggested that pain reduction might be greater in the 14 days after treatment with blinded cetuximab than after placebo. The proportion of patients who reported ≥50% reduction in average pain three to seven days after cetuximab was 36% (14% after placebo), and comparison of overall pain reduction suggests a trend in favor of cetuximab. Skin rash (grade 1–2) was the most frequent side effect (12/14, 86%). Conclusions This small proof-of-concept evaluation of an EGFR-I against NP did not provide statistical evidence of efficacy. However, substantial reductions in pain were reported, and confidence intervals do not rule out a clinically meaningful treatment effect. Evaluation of EGFR-I against NP therefore warrants further investigation. [ABSTRACT FROM AUTHOR]

The article focuses on Analyzing Spinal Cord Stimulator Explants in Refractory Angina Pectoris Patients. Topics discussed include Spinal cord stimulation (SCS) is a form of neuromodulation that provides electrical stimulation to the spinal cord and interferes with pain signals traveling to the brain; and the goal of SCS is to diminish the patient's sensation of pain and, in doing so, decrease physical limitations and improve functional status.

Background This study aimed to evaluate the wireless Freedom Spinal Cord Stimulator (WSCS) System for the treatment of chronic back and/or leg pain associated with failed back surgery syndrome (FBSS) refractory to standard medical treatment utilizing 10-kHz stimulation (high-frequency [HF]) in comparison with 10–1,500-Hz stimulation (low-frequency [LF]) waveforms. Methods Ninety-nine subjects were randomized in a 1:1 ratio to receive either HF or LF stimulation waveforms utilizing the same Freedom WSCS System. All subjects were implanted with two 8-electrode arrays in the exact same anatomical positions within the dorsal epidural spinal column, with the top electrode positioned at the T8 and T9 vertebrae levels, respectively, and the wireless receiver placed under the skin in a subcutaneous pocket. Results Seventy-two (HF: N = 38; LF: N = 34) subjects had completed the six-month follow-up after an initial 30-day trial period at the time of this report. For both the HF and LF arms, mean visual analog scale (VAS) scores for back and leg pain decreased significantly: 77% and 76%, respectively, for the HF arm and 64% and 64%, respectively, for the LF arm. In addition, most subjects experienced significant improvements in VAS, Oswestry Disability Index, European Quality of Life 5 Dimension questionnaire, Patient Global Impression of Change, and sleep duration. Conclusions These preliminary results demonstrate that WSCS devices can reduce FBSS chronic pain substantially with both LF and HF stimulation waveforms over a seven-month period (30-day trial period and six-month post-trial evaluation). [ABSTRACT FROM AUTHOR]

Background Radicular pain is related to lesions that either directly compromise the dorsal root ganglion (DRG) or indirectly compromise the spinal nerve and its roots by causing ischemia or inflammation of the axons. Objective Our study aimed to assess the outcomes of pulsed readiofrequency treatment (PRF) according to electrodiagnosis results in patients with chronic intractable lumbosacral radicular pain. Methods A total of 82 failed back surgery syndrome (FBSS) patients were included in this study. All of them underwent electromyography/nerve conduction studies before pulsed radiofrequency (PRF) treatment at the DRG, and they were classified according to the electrodiagnostic results as: group 1, no definite finding (normal); group 2, radiculopathy; and group 3, neuropathy. Pain intensity was assessed according to a numeric rating scale score and the Oswestry Disability Index (ODI) before treatment and at one, three, six, and 12 months after treatment, and successful treatment was defined as a pain score reduction of ≥50% at 12 months, as compared with the pretreatment score. Results Pretreatment electrodiagnosis identified 28 patients with no definite findings, 31 patients with radiculopathy, and 23 patients with neuropathy. The patients with neuropathy had less pain relief after treatment than those with no definite findings and those with radiculopathy. The prevalence of pain reduction of at least 50% was lower in the neuropathy group than in the other groups. There was no statistically significant difference in ODI between group. Conclusion Outcomes after PRF at the DRG did not show strong differences according to electrodiagnostic findings in FBSS patients with chronic intractable lumbosacral radicular pain. [ABSTRACT FROM AUTHOR]

Background: Descending nociceptive inhibitory pathways often malfunction in people with chronic pain. Conditioned pain modulation (CPM) is an experimental evaluation tool for assessing the functioning of these pathways. Spinal cord stimulation (SCS), a well-known treatment option for people with failed back surgery syndrome (FBSS), probably exerts its pain-relieving effect through a complex interplay of segmental and higher-order structures. Objective: To the best of our knowledge, no clinical studies have thoroughly investigated the associations between SCS and CPM. Design: This was a prospective cohort study in people with FBSS. Methods: Seventeen people who had FBSS and were scheduled for SCS were enrolled in this study. The CPM model was evaluated at both sural nerves and was induced by electrical stimulation as the test stimulus and the cold pressor test as the conditioning stimulus. Results: Before SCS, less than 30% of the participants with FBSS showed a CPM effect. Significant increases in the electrical detection threshold on the symptomatic side and the nonsymptomatic side were found. On the symptomatic side, no differences in the numbers of CPM responders before and after SCS could be found. On the nonsymptomatic side, more participants showed a CPM effect during SCS. Additionally, there were significant differences for CPM activation and SCS treatment. Limitations: Limitations were the small sample size and the subjective outcome parameters in the CPM model. Conclusions: This study revealed a bilateral effect of SCS that suggests the involvement of higher-order structures, such as the periaqueductal gray matter and rostroventromedial medulla (key regions in the descending pathways), as previously suggested by animal research. [ABSTRACT FROM AUTHOR]

Objectives The aims of this study were to identify the reasons for explanation of spinal cord stimulator (SCS) devices and to further quantify the proportions and time lines of these causes of explantation in order to determine improvement opportunities for the development of best practices. Design Retrospective, single academic center. Materials and Methods Patients who were implanted with percutaneous SCS devices from 2002 to 2015 and with follow-up available until the end of September 2017 were included in this retrospective chart analysis. Results Of the 356 patients trialed, 252 underwent implantation of an SCS device with a permanent to trial ratio of 71%. Of the patients who had a permanent implant, 50% had failed back surgery syndrome, 25% had complex regional pain syndrome, and 25% had other diagnoses. At the end of the study period, the explantation rate was 30%. The causes for explantation included biological complications (26.6%), paresthesia limitations or side effects (26.6%), hardware complications (13.3%), ineffective pain control (28%), and no further need for stimulation therapy (5.3%). Conclusions Device removal is not uncommon, and opportunities to enhance the long-term success of SCS devices do exist. These include modification of trialing methods, achieving better paresthesia overlay, using magnetic resonance imaging (MRI) conditional equipment, development of robust technologies and hardware to reduce equipment malfunction, and improving efficacy with new innovative wave forms. [ABSTRACT FROM AUTHOR]

Background Failed back surgery syndrome (FBSS) has a profound impact on patients' quality of life and represents a major clinical challenge and a significant economic burden for society. Adhesiolysis is used as a treatment to eliminate perineural/epidural adhesions in patients with chronic pain attributed to FBSS. Objective To evaluate the efficacy, effectiveness, safety, and cost-effectiveness of epidural adhesiolysis compared with other procedures for treating FBSS. Method A systematic review was conducted. The electronic databases Medline/PreMedline, EMBASE, Cochrane Library Plus, Centre for Reviews and Dissemination databases, SCOPUS, Science Citation Index, and PEDRO were consulted through April 2017. Predefined criteria were used to determine inclusion of the studies and to assess their methodological quality. Results Ten reports were included. No randomized controlled trials (RCTs) on efficacy or cost-effectiveness were found. Three reports (corresponding to two RCTs, N = 212) suggested that adhesiolysis was effective, especially for pain and disability. However, both studies presented serious methodological flaws. In addition to RCTs, seven observational studies with high risk of bias reported data on effectiveness and safety. Fifty-eight adverse events were reported among 130 patients undergoing endoscopic adhesiolysis, and 19 among the 110 undergoing percutaneous adhesiolysis. Conclusions The evidence on the efficacy and cost-effectiveness of adhesiolysis for treating FBSS is nonexistent, whereas evidence on its effectiveness and safety is insufficient. Incorporating data from observational studies did not improve the quality of the evidence on effectiveness. [ABSTRACT FROM AUTHOR]

Objective. Epiduroscopy is a proven method of diagnosis and treatment for chronic radicular pain after spinal surgery, which is known as failed back surgery syndrome (FBSS). The aim of the study was to compare the efficacy of drugs (the enzyme hyaluronidase and corticosteroid DEPO-Medrol) administrated into the epidural space during epiduroscopy, performed within the ventral and ventro-lateral epidural space with a focus on releasing foraminal adhesions. Methods. Forty-eight patients with diagnosed FBBS were randomized into two groups before epiduroscopy. Group A received the standard treatment- mechanical lysis of fibrotic tissue in the epidural space. Group B received hyaluronidase and corticosteroid methylprednisolone acetate during the procedure. Subjects were followed for six and 12 months via scheduled double-blinded examinations by pain physicians. Leg and back pain intensity was assessed by an 11-point numerical rating scale, and patients' functional disability was assessed by the Oswestry Disability Index (ODI). Results. Study subjects showed a significant decrease in ODI score in both groups (P< 0.05). Significantly lower pain scores for leg pain (P< 0.05) and back pain (P< 0.05) were also recorded after the six-month follow-up. However, the one-year followup showed a return to the baseline ODI values of most monitored pain scores in both groups (P> 0.05). Improvement was only noted on the NRS for back pain at one-year follow-up (P< 0.05). Conclusions. A significant improvement of leg and back pain was found in both groups after six months. ODI was significantly improved only in group B in both the six- and 12-month intervals. Back pain at one-year follow-up was only improved in group B. [ABSTRACT FROM AUTHOR]

Objectives. Spinal cord stimulation (SCS) for patients with failed back surgery syndrome (FBSS) show variable results and limited to moderate evidence. In the last years the stimulation of high frequency (HF) has been considered as a better alternative in this pathology for its supposed benefits compared to the stimulation with conventional frequency (CF). To compare in one year follow-up, the efficacy of high-frequency SCS (HF) versus conventional frequency SCS (CF) on the patients with FBSS. Design. Prospective, Randomized blind trial. Setting. Academic University Pain Medicine Center. Subject. Seventy eight patients with FBSS diagnosis based on internationally recognized criteria, and refractory to conservative therapy for at least 6 months, have been initially recruited. Methods. Sixty subjects met the eligibility criteria and were randomized and scheduled for the trial phase. The patients were randomly assigned in either, one of the two groups: CF SCS or HF SCS. Within the study methods, special attention was paid to standardizing patient programming, so that these parameters would not impact the results. The trial period was considered successful if there was ? 50% reduction in the NRS from baseline. Results. A total of 55 subjects successfully completed all assessments during one year follow-up. Change patterns in scores do not differ based on high versus conventional frequency, with significant global average reduction at 1year similarly for both groups. Among all the items included in the Short Form-12 questionnaire (SF-12), only the variations in the social function score between the instants t1 and t2 are somewhat higher in the high frequency group. Conclusion. The evolutionary pattern of the different parameters studied in our patients with FBSS does not differ according to their treatment by spinal stimulation, with conventional or high frequency, in one year follow-up. [ABSTRACT FROM AUTHOR]

Objectives. Test a miniaturized neurostimulator transforaminally placed at the dorsal root ganglion (DRG) and evaluate the device's safety and efficacy in treating failed back surgery syndrome (FBSS) low back pain. Design. Pilot, two-phase study. Subjects. Eleven subjects with chronic intractable neuropathic trunk and/or lower limbs pain were included. Methods. The system consisted of an implantable, miniaturized stimulator, provided by Stimwave Technologies (Freedom-4) and an external transmitter. Only one stimulator per subject was implanted unilaterally and transforaminally at L1 to L5 levels. During Phase 1 of the study, the stimulators were not anchored. In Phase 2, the stimulators were anchored. Subjects were treated during 45 days after which the stimulator was removed. Pain reduction, implant duration, and stimulator migration were registered. Results. Overall pain reduction was 59.9%, with only one device placed at one location, covering only a portion of the painful areas in the majority of the subjects. In Phase 1, the non-anchored stimulators migrated a mean of 8.80mm and in Phase 2 a mean of 1.83mm. Stimulator migration did not correlate with changes in pain relief. Mean time-to-implant duration was 10minutes and no adverse events were reported during implant, follow-up period, or after explant. Conclusions. The pain reduction results indicate that the Freedom-4 spinal cord stimulation (SCS) Wireless System is a viable treatment of low back pain through stimulation of the DRG, and better overall pain reduction may be achieved by implanting multiple devices. With short percutaneous implant times and excellent safety profile, this new system may offer health cost savings. [ABSTRACT FROM AUTHOR]

Background. Intrathecal (IT) pumps have become a valuable tool in managing intractable non-cancer pain. The purpose of this study was to evaluate the efficacy of using a rigorous treatment algorithm for trialing and implanting IT pumps with hydromorphone and bupivacaine in managing a more homogeneous population of post-laminectomy syndrome or failed back surgery syndrome (FBSS) patients. Methods. This is a retrospective analysis of FBSS patients with chronic intractable back pain implanted with IT pumps delivering hydromorphone and bupivacaine. Results. A cohort of 57 (26 males, 31 females) consecutively implanted FBSS patients was analyzed. The average age at implant was 65.4 years. Average pain scores were 8.4±0.2 (pre-implant), 4.9±0.4 (6 months), 5.2±0.5 (12 months), and 4.3±0.5 (24 months). Average oral opioid doses in morphine equivalents were 56±10 mg/day (pre-implant), 12.0±3.5 mg/day (12 months), 15±6 mg/day (24 months). Average IT hydromorphone doses were 79±6.8 mcg/day (at implant), 184±22 mcg/day (6 months), 329±48 mcg/day (12 months), and 487±80 mcg (24 months). IT hydromorphone dose escalation from baseline was 133% (6 months vs baseline), 78% (12 months vs 6 months), and 48% from 12 months to 24 months. Average IT bupivacaine doses were 5.8±0.3 mg/day (implant), 9.5±0.6 mg/day (6 months), 12.2±0.7 mg/day (12 months), and 12.6±0.9 mg/day (24 months). Conclusion. IT hydromorphone and bupivacaine are effective in treating chronic pain of FBSS, as demonstrated by the reduction of pain intensity and oral opioid consumption. However, an IT dose escalation phenomenon was observed, although at a reduced rate compared with what had been previously reported in the literature. It is possible that the local anesthetic combination delivered via a patient-activaed bolus device is an important factor. Despite demonstrating effectiveness, the clinical utility of myPTM-optimized IT therapy remains limited by a lack of prospective, placebo-controlled trials and comparative effectiveness research. [ABSTRACT FROM AUTHOR]

Objective. Pregabalin group (PGB) is an antiepileptic used to treat neuropathic pain. We evaluated analgesic efficacy and safety for postoperative/ chronic pain, disability, and sleep quality in patients who underwent spine surgery administered with PGB, or not, during the presurgical and postsurgical periods. Design. Retrospective cohort study of 60 patients (two groups with 30 patients) with full information on 50 (29 with PGB and 21 without PGB). Ten patients were dismissed as information was lacking. The PGB group (P) (29 patients) received 75 mg/12 hours before surgery, 150 mg 10 hours after surgery, and 150 mg/12 hours 3 days after surgery. The control group (C; 21 patients) took no PGB. Methods. Neuropathic pain was assessed before surgery, and 2 and 6 months later using visual analog scales (VAS), DN4, disability (Oswestry), and sleep quality. No serious adverse events occurred with PGB. Results. The median VAS pain score at rest was lower in the PGB group at 2 months postsurgery (1 vs 2, P=0.032), as was the median DN4 score (0 vs 3, P=0.032) and the median Oswestry disability index (ODI: 12 vs 18, P=0.001). At 6 months postsurgery, pain scores were also lower in the PGB group for VAS (0 vs 4, P=0.001), DN4 score (0 vs 4, P=0.001) and the ODI (10 vs 24, P=0.001). Improvement in the functionality and sleep quality of the PGB group was noteworthy (P=0.018). Conclusions. PGB has analgesic/antihyperalgesic effects on postoperative neuropathic pain after surgery for lumbar disc hernia. Our findings show that this benefit increases with time. [ABSTRACT FROM AUTHOR]

The authors discuss a study that examines two different types of epidural lysis of adhesions. Study highlights include association of adhesions and fibrosis in the epidural space with a history of prior spine surgery or spinal stenosis, improvements in both groups in terms of function, back pain, and leg pain at six-month follow-up, and institution of regulatory measures such as limiting the overuse of procedures.

Objective. Chronic pain remains a serious public health problem worldwide. A spinal cord stimulation (SCS) therapy called HF10 SCS uses 10-kHz high-frequency stimulation to provide pain relief without paresthesia. In this article, we describe the therapy, device, and the methods of implant and then review the safety and effectiveness data for this therapy. Results. HF10 SCS uses a charge-balanced stimulation waveform that has been shown to be safe in both animal and human studies. Data from a multi-center, prospective clinical trial shows that the therapy provides substantial back and leg pain relief. Numerous additional reports suggest improved pain relief in other body areas and for complex pain patterns, even for patients who have previously failed other neuromodulation therapies. Conclusions. The clinical experience reported in this article supports the efficacy and pain relief provided by HF10 SCS therapy. Clinical studies have also concluded that HF10 SCS does not generate paresthesia nor was it necessary to provide adequate coverage for pain relief. As clinical evidence accumulates and technological innovation improves patient outcomes, neuromodulatory techniques will be sought earlier in the treatment continuum to reduce the suffering for the many with otherwise intractable chronic pain. [ABSTRACT FROM AUTHOR]

The article describes a case study by 2 renowned authorities on intrathecal opioids namely Doctor John Loeser and Tim Deer regarding patient Mrs. Jones with failed back surgery syndrome habituated to oral opioid where they expressed their opinion on whether intrathecal opioid therapy can be appropriate for her. Pump placement for intrathecal administration of opioiids was considered after her pain increased and she became less functional despite an increase of oxycodone to 150 milligram.

Objective The aim of this study was to investigate the long-term efficacy and safety of paresthesia-free high-frequency spinal cord stimulation ( HF10 SCS) for the treatment of chronic, intractable pain of the low back and legs. Design Prospective, multicenter, observational study. Method Patients with significant chronic low back pain underwent implantation of a spinal cord stimulator capable of HF10 SCS. Patients' pain ratings, disability, sleep disturbances, opioid use, satisfaction, and adverse events were assessed for 24 months. Results After a trial period, 88% (72 of 82) of patients reported a significant improvement in pain scores and underwent the permanent implantation of the system. Ninety percent (65 of 72) of patients attended a 24-month follow-up visit. Mean back pain was reduced from 8.4 ± 0.1 at baseline to 3.3 ± 0.3 at 24 months ( P < 0.001), and mean leg pain from 5.4 ± 0.4 to 2.3 ± 0.3 ( P < 0.001). Concomitantly to the pain relief, there were significant decreases in opioid use, Oswestry Disability Index score, and sleep disturbances. Patients' satisfaction and recommendation ratings were high. Adverse Events were similar in type and frequency to those observed with traditional SCS systems. Conclusions In patients with chronic low back pain, HF10 SCS resulted in clinically significant and sustained back and leg pain relief, functional and sleep improvements, opioid use reduction, and high patient satisfaction. These results support the long-term safety and sustained efficacy of HF10 SCS. [ABSTRACT FROM AUTHOR]

Objective To evaluate the cost-effectiveness of spinal cord stimulation ( SCS) and conventional medical management ( CMM) compared with CMM alone for patients with failed back surgery syndrome ( FBSS), complex regional pain syndrome ( CRPS), peripheral arterial disease ( PAD), and refractory angina pectoris ( RAP). Design Markov models were developed to evaluate the cost-effectiveness of SCS vs CMM alone from the perspective of a Canadian provincial Ministry of Health. Each model followed costs and outcomes in 6-month cycles. Health effects were expressed as quality-adjusted life years ( QALYs). Costs were gathered from public sources and expressed in 2012 Canadian dollars ( CAN$). Costs and effects were calculated over a 20-year time horizon and discounted at 3.5% annually, as suggested by the National Institute of Clinical Excellence. Cost-effectiveness was identified by deterministic and probabilistic sensitivity analysis (50,000 Monte- Carlo iterations). Outcome measures were: cost, QALY, incremental net monetary benefit ( INMB), incremental cost-effectiveness ratio ( ICER), expected value of perfect information ( EVPI), and strategy selection frequency. Results The ICER for SCS was: CAN$ 9,293 ( FBSS), CAN$ 11,216 ( CRPS), CAN$ 9,319 ( PAD), CAN$ 9,984 ( RAP) per QALY gained, respectively. SCS provided the optimal economic path. The probability of SCS being cost-effective compared with CMM was 75-95% depending on pathology. SCS generates a positive INMB for treatment of pain syndromes. Sensitivity analyses demonstrated that results were robust to plausible variations in model costs and effectiveness inputs. Per-patient EVPI was low, indicating that gathering additional information for model parameters would not significantly impact results. Conclusion SCS with CMM is cost-effective compared with CMM alone in the management of FBSS, CRPS, PAD, and RAP. [ABSTRACT FROM AUTHOR]

Objective To assess the effectiveness of a muscle protocol to treat patients diagnosed with neuraxial low back pain ( LBP) before and after invasive treatments. Design Patients with chronic (>6 months) LBP-postinvasive treatment and pre-spine surgery-were assessed and treated. An electrical device rather than palpation was used to determine muscle(s) as possible sources of pain. Patients testing positive for muscle pain were treated with a comprehensive protocol and were followed for >3 months to determine the effect of treatment on pain severity and interference in function. Results Study 1: In 56 (postinvasive treatment) patients who had failed back surgery, epidural steroid injections, facet blocks, and/or trigger point injections, mean Brief Pain Inventory ( BPI) pain severity dropped from 5.54 at baseline to 3.96 ( P < 0.001) at a median follow-up of 77 weeks; mean BPI interference dropped from 6.09 to 3.4 ( P < 0.001). Fifty-two percent of respondents reported over 50% relief. Study 2: Three of seven patients originally scheduled for spine surgery completed a substantial part of the muscle protocol, canceled their surgeries, and obtained significant relief at the 16-19 month follow-up point. Conclusion In patients thought to have neuraxial pain, identification and treatment of painful muscles had statistically significant long-lasting and clinically meaningful reductions in pain and improvement in function. Muscle and tendon attachments may be an important and treatable source of pain in patients diagnosed with pre and postsurgical neuraxial pain. [ABSTRACT FROM AUTHOR]

Background. The antinociceptive effect of intrathecal midazolam is based on its affecting spinal gamma-amino butyric acid receptors. Objective. To evaluate pain relief in patients with chronic low back pain and failed back surgery syndrome after a single-shot intrathecal administration of midazolam. Design. A prospective, open-label study. Outcome Measures. The analgesic effect was determined using a patient questionnaire during subsequent visits to the pain therapy service. We classified at least a 50% pain reduction with improved quality of life and improved functional condition as a positive outcome. Results. Between 1995 and 2010, we performed 500 administrations: 227 administrations in 57 male patients and 273 administrations in 69 female patients. We performed 81 administrations for chronic low back pain and 419 administrations for failed back surgery syndrome. The average age of our patients was 50 years (range 28 to 86). The dose administered ranged from 2 to 5 mg of midazolam. The analgesic effect lasted 9.7 weeks on average, ranging from 1 week to 3 years; the most common reported duration was between 4 and 12 weeks (3 months). In 65% of patients, we achieved pain relief lasting 4 weeks or longer; in 13%, the administration provided no analgesic effect at all. The incidence of side effects (drowsiness, nausea, headache, or transient worsening of complaints) was rather low. Conclusion. Intrathecal midazolam is a useful supplement to standard analgesic therapy with opioids, non-opioids, or spinal steroids. [ABSTRACT FROM AUTHOR]

Failed back surgery syndrome (FBSS) is a chronic pain condition that has considerable impact on the patient and health care system. Despite advances in surgical technology, the rates of failed back surgery have not declined. The factors contributing to the development of this entity may occur in the preoperative, intraoperative, and postoperative periods. Due to the severe pain and disability this syndrome may cause, more radical treatments have been utilized. Recent trials have been published that evaluate the efficacy and cost-effectiveness of therapeutic modalities such as spinal cord stimulation for the management of patients with failed back surgery. This article will describe the epidemiology and etiology of FBSS. The importance of prevention will be emphasized. In those patients with established FBSS, a guide to interdisciplinary evaluation and management will be outlined. Special attention will focus on recent trials that have studied the efficacy of more invasive procedures such as spinal cord stimulation. Finally, a suggested management pathway is presented. FBSS is a challenging clinical entity with significant impact on the individual and society. To better prevent and manage this condition, knowledge of the factors contributing to its development is necessary. While research on FBSS has increased in recent years, perhaps the best strategy to reduce incidence and morbidity is to focus on prevention. Patients diagnosed with FBSS should be managed in an interdisciplinary environment. More radical treatments for FBSS have now been extensively studied providing clinicians with much needed evidence on their efficacy. Incorporating these results into our current knowledge provides a basis on which to construct an evidence-based guide on how best to manage patients who suffer from FBSS. [ABSTRACT FROM AUTHOR]

Background. The use of pulsed radiofrequency (PRF) for treatment of the medial branch is controversial. Study Design. A retrospective study of the results of PRF treatment of the medial branch in 48 patients with chronic low back pain was carried out. Patients who did not respond were offered treatment with conventional radiofrequency heat lesions. Patient Material. Patients were included who had low back pain and >50% pain relief following a diagnostic medial branch block. The mean age was 53.1 ± 13.5 years, the mean duration of pain was 11.4 ± 10.9 years (range 2-50). Nineteen patients had undergone surgery. Methods. Pain scores on a numeric rating scale of 1-10 were noted before and after the diagnostic nerve block, before the procedure, and at 1-month and 4-month follow-up. PRF was applied for 2 minutes at a setting of 2 × 20 ms/s and 45 V at a minimum of two levels using a 22G electrode with a 5 mm active tip. Heat lesions were made at 80°C for 1 minute. Outcome Definition. A successful outcome was defined as a >60% improvement on the numeric rating scale at 4-month follow-up. Results. In 21/29 nonoperated patients and 5/19 operated patients, the outcome was successful. In the unsuccessful patients who were subsequently treated with heat lesions, the success rate was 1/6. Conclusion. The setup of our study does not permit a comparison with the results of continuous radiofrequency (CRF) for the same procedure, other than the detection of an obvious trend. When comparing our results with various studies on CRF of the medial branch such a trend could not be found. Based on these retrospective data, prospective and randomized trials, for example, radiofrequency vs PRF are justified. [ABSTRACT FROM AUTHOR]

Abstract Study Design. Retrospective chart review. Objective. To report the epidemiologic data of nonsurgical and surgical etiologies of failed back surgery syndrome (FBSS) from two outpatient spine practices. Summary of Background Data. FBSS has been offered as a diagnosis, but this is an imprecise term encompassing a heterogeneous group of disorders that have in common pain symptoms after lumbar surgery. The current literature primarily diagnoses for the various etiologies of FBSS from a surgical perspective. To our knowledge, there is no study that investigates the myriad of surgical and nonsurgical diagnoses from a nonsurgical perspective. Methods. Specific inclusion and exclusion criteria were developed for a list of 42 nonsurgical and surgical differential diagnoses of FBSS. The determination of which category, surgical or nonsurgical, each diagnosis was placed into depended upon the categorization of those diagnoses in previously published literature on FBSS. Each of the authors reviewed the definitions, and they came to a unanimous agreement on each diagnosis' inclusion and exclusion criteria. Data extraction was then carried out in each of the two involved institutions by using the key words discectomy, laminectomy, and fusion to identify all the patients who had any combination of low back, buttock, or lower extremity pain after lumbar discectomy surgery. These charts were then individually reviewed to extract epidemiologic data. Results. A total of 267 charts were reviewed. One hundred and ninety-seven (197) charts had a complete workup. Of these, 11 (5.6%) had an unknown etiology, and 186 had a known diagnosis. Twenty-three (23) various diagnoses were identified. There was approximately an equal distribution between the incidences of nonsurgical and surgical diagnoses; 44.4% had nonsurgical diagnoses and 55.6% had surgical diagnoses. The most common diagnoses identified were spinal stenosis, internal disc disruption syndrome, recurrent/retained disc,... [ABSTRACT FROM AUTHOR]

The article focuses on the safety of spinal cord stimulation (SCS) for treating chronic pain disorders in patients with a prior permanent pacemaker or implantable cardioverter defibrillator. It discusses the importance of a basic understanding of permanent pacemaker or implantable cardioverter defibrillator, cites studies and trials that demonstrate the safety and effectiveness of an SCS system, and offers suggestions to maximize safety and minimize complications of SCS.

A letter to the editor about a patient who experienced seizure and transient neurological deficits during epiduroscopy is presented.

The author discusses the efficacy of intrathecal opioids in relieving various types of pain although most studies show patients on high-does opioids without pain relief are poor candidates. Topics discussed include the need to remember that chronic pain is not an opioid deficiency state and that pain relief alone is not an adequate treatment goal and the author's belief that the patient needs more than opioids to be functional.