Predominant Pain Research Articles

Improvements in Back and Leg Pain After Minimally Invasive Lumbar Decompression.

Few studies have quantified clinical improvement following minimally invasive lumbar decompression based on predominant back pain or leg pain. To quantify improvement in patient-reported outcomes following minimally invasive lumbar decompression and determine the degree of improvement in back pain, leg pain, and disability in patients who present with predominant back pain or predominant leg pain. Patients who underwent primary, one-level minimally invasive lumbar decompression for degenerative pathology were retrospectively reviewed. Comparisons of visual analog scale (VAS) back and leg pain scores, Oswestry Disability Index (ODI) scores, and Short Form-12 (SF-12) mental and physical component scores from pre-operative to 6-week, 12-week, 6-month, and 1-year follow-up. Subgroup analyses were performed for patients with predominant back pain or predominant leg pain. A total of 102 patients were identified. Scores on VAS back and leg pain, ODI, and SF-12 physical component improved from pre-operative to all post-operative time points. After 1year, patients reported a 2.8-point (47%) reduction in back pain and a 4-point (61.1%) reduction in leg pain scores; 52 patients with predominant back pain and 50 patients with predominant leg pain reported reductions in pain throughout the year following surgery. In both the back and leg pain cohorts, patients experienced reductions in ODI during the first 6months and throughout 1-year follow-up, respectively. The majority of patients achieved minimum clinically important difference, regardless of predominant symptom. Patients reported improvements in back and leg pain following minimally invasive lumbar decompression regardless of predominant presenting symptom; however, patients with predominant leg pain may experience greater improvement than those with predominant back pain.

Multicolumn spinal cord stimulation for predominant back pain in failed back surgery syndrome patients: a multicenter randomized controlled trial.

Despite optimal medical management (OMM), low back pain (LBP) can be disabling, particularly after spinal surgery. Spinal cord stimulation (SCS) is effective in reducing neuropathic leg pain; however, evidence is limited for LBP. This prospective, open-label, parallel-group trial randomized (1:1) failed back surgery syndrome (FBSS) patients with predominant LBP to SCS plus OMM (SCS group) or OMM alone (OMM group) at 28 sites in Europe and the Americas. If trial stimulation was successful, a multicolumn SCS system was implanted. Outcomes were assessed at baseline (before randomization) and at 1, 3, 6, and 12 months after randomization. Patients could change treatment groups at 6 months. The primary outcome was the proportion of patients with ≥50% reduction in LBP (responder) at 6 months. Secondary outcomes included change in pain intensity, functional disability, and health-related quality of life (HRQoL). The results are posted at ClinicalTrials.gov under registration number NCT01697358. In the intent-to-treat analysis, there were more responders in the SCS group than in the OMM group (13.6%, 15/110 vs 4.6%, 5/108, difference 9% with 95% confidence interval 0.6%-17.5%, P = 0.036) at 6 months. The SCS group improved in all secondary outcomes compared with the OMM group. The OMM group only improved in HRQoL. In the SCS group, 17.6% (18/102) experienced SCS-related adverse events through 6 months, with 11.8% (12/102) requiring surgical reintervention. Adding multicolumn SCS to OMM improved pain relief, HRQoL, and function in a traditionally difficult-to-treat population of failed back surgery syndrome patients with predominant LBP. Improvements were sustained at 12 and 24 months.

Oral medicine psychiatric liaison clinic: study of 1202 patients attending over an 18-year period

Patients with orofacial pain and discomfort often suffer from psychiatric disorders. However, few studies involving a large sample have examined the diagnostic results of patients with orofacial pain or discomfort in relation to psychiatric disorders. The purpose of this study was to summarize and clarify the characteristics and demographic data of 1202 patients attending the psychiatric liaison clinic at Aichi Gakuin University Hospital. Psychiatric diagnosis was performed by psychiatrists for all patients, based on the Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Among the 1202 patients, 992 (82.5%) were female. The average age of the patients was 57.2±15.0years. The predominant broad categories of orofacial pain and discomfort seen were burning mouth syndrome (n=484, 40.3%), persistent idiopathic facial pain (n=258, 21.5%), and oral dysesthesia (n=215, 17.9%). The predominant broad categories of psychiatric diagnoses seen were somatic symptoms and related disorders (n=934, 77.7%) and depressive disorders (n=76, 6.3%). Among the 934 patients with somatic symptoms and related disorders, 678 had a somatic symptom disorder with predominant pain. The results confirmed that most patients with orofacial pain and discomfort were middle-aged and elderly women suffering from a somatic symptom disorder with predominant pain.

Chronic Pain in Breast Cancer Survivors: Nociceptive, Neuropathic, or Central Sensitization Pain?

The differentiation between acute and chronic pain can be insufficient for appropriate pain management. The aim of this study was to evaluate the prevalence of the predominant pain type (nociceptive, neuropathic, or central sensitization [CS] pain) in breast cancer survivors (BCS) with chronic pain. The secondary aims were to examine (1) differences in health-related quality of life (HRQoL) between the different pain groups; and (2) the associations between patient-, disease-, and treatment-related factors and the different pain types. To determine the prevalence of the predominant type of pain, a recently proposed classification system was used. BCS were asked to complete the VAS for pain, Douleur Neuropathique 4 Questionnaire, Margolis Pain Diagram, Central Sensitization Inventory, and Short Form 36 (SF-36). Ninety-one BCS participated, among whom 25.3% presented neuropathic pain, 18.7% nociceptive pain, and 15.4% CS pain. Mixed pain was found in 40.6%. A significant intergroup difference in HRQoL was found for SF-36 "general health" (P=0.04). The odds for the presence of CS rather than nociceptive pain are 26 times higher in patients exposed to hormone therapy in comparison to the nonexposed (odds ratio 25.95, 95% confidence interval 1.33 to 504.37, P=0.03). Neuropathic pain is most frequent in BCS. Strong associations were found between CS pain and hormone therapy.

The interrater reliability of a pain mechanisms-based classification for patients with nonspecific neck pain

ObjectiveTo examine the interrater reliability and agreement of a pain mechanisms-based classification for patients with nonspecific neck pain (NSNP). MethodsDesign – Observational, cross-sectional reliability study with a simultaneous examiner design. Setting: University hospital-based outpatient physical therapy clinic. Participants: A random sample of 48 patients, aged between 18 and 75 years old, with a primary complaint of neck pain was included. Interventions: Subjects underwent a standardized subjective and clinical examination, performed by 1 experienced physical therapist. Two assessors independently classified the participants’ NSNP on 3 main outcome measures. Main outcome measures: The Cohen kappa, percent agreement, and 95% confidence intervals (CIs) were calculated to determine the interrater reliability for (1) the predominant pain mechanism; (2) the predominant pain pattern; and (3) the predominant dysfunction pattern (DP). ResultsThere was almost perfect agreement between the 2 physical therapists’ judgements on the predominant pain mechanism, kappa=.84 (95% CI, .65–1.00), p<.001. There was substantial agreement between the raters’ judgements on the predominant pain pattern and predominant DP with respectively kappa=.61 (95% CI, .42–.80); and kappa=.62 (95% CI, .44–.79), p<.001. Conclusion(s)The proposed classification exhibits substantial to almost perfect interrater reliability. Further validity testing in larger neck pain populations is required before the information is used in clinical settings. Clinical trial registration numberNCT03147508 (https://clinicaltrials.gov/ct2/show/NCT03147508).

The strategy and results of percutaneous endoscopic surgery for cervical disc herniation

Objective To evaluate the strategy and clinical effects of percutaneous endoscopic surgery for cervical disc herniation. Methods Fifty-one patients with cervical disc herniation were treated with percutaneous endoscopic surgery from June 2015 to March 2017, including 32 men and 19 women, with an average age of 52.2 years (range, 28-66 years). Radicular symptoms were present in all patients, while 23 patients had mild myelopathy (Nurick Grade: 0-3) and 3 patients of multilevel stenosis had severe myelopathy (Nurick Grade: 4-5). According to axial image of preoperative magnetic resonance imaging (MRI), 31 patients had lateral herniation that was located lateral to the edge of spinal cord, 20 patients had central herniation that was located within the lateral edge of spinal cord. Among them, 48 patients had soft herniation and 3 patients had ossified lateral herniation combined with foraminal stenosis. All surgery was carried out under general anesthesia, while posterior and anterior percutaneous endoscopic surgeries were performed for lateral herniation and central herniation respectively. Posterior endoscopic surgery was performed with keyhole fenestration at V point (the junction of lateral edge of lamina space and inner edge of facet). Lateral edge of thecal sac and nerve root were exposed and decompressed, soft herniation was explored and removed. Anterior endoscopic surgery was performed through puncture and 4mm tube between the visceral sheath and vascular sheath. The tube was inserted through disc to the base of herniation under fluoroscopy. The herniation was removed until the dura sac was exposed and relaxed. One stage open-door laminoplasty was performed for 3 patients with severe multiple segmental stenosis and huge central herniation. The operative time and blood loss were recorded, and patients were followed-up (range, 6-18 months, average 12.1 months) to evaluate the clinical efficacy. Results The mean operative time of posterior endoscopic surgery was 90 min (range, 45-150 min). The nerve root was not well exposed, and the fenestration was too lateral in 1 patient, with partial relieve of symptoms; and simple nerve root decompression was performed for 3 patients of ossified herniation combined with foraminal stenosis. Herniated or sequestered nucleus pulposus was removed for 27 patients, one of them had transient paralysis ipsilateral limb and 2 of them had linkage of cerebrospinal fluid. The Visual Analogue Score (VAS) score improved form preoperative 8.9±1.6 to 0.5±0.4, and the Oswestry Disability Index (ODI) score improved form 32.8±4.2 to 2.3±1.9 at final follow-up. For anterior percutaneous endoscopic surgery, the mean operative time was 80 min (range, 45–120 min). Herniated or free nucleus was successfully removed for all patients. The thecal sac was lacerated due to unclear exposure in 1 case. The VAS score improved form preoperative 6.9±2.3 to 0.9±0.8, and the ODI score improved form 40.1±8.6 to 5.6±3.0 at final follow-up, with improvement of myelopathy at least one Nurick Grade. During follow-up, the alignment of cervical spine was well preserved without kyphosis for two groups, while the height of intervertebral space decreased with 0.4±0.3 mm and 0.9±0.6 mm in posterior and anterior surgery respectively. Conclusion Percutaneous endoscopic surgery provides minimally invasive alternatives for some cervical disc herniation with predominant radicular pain. Posterior endoscopic surgery is suitable for lateral herniation, and anterior endoscopic discectomy is suitable for some central soft herniation without obvious collapse and instability. However, the long-term results of disc space collapsed after anterior approach remains unclear. Key words: Cervical vertebrae; Intervertebral disc displacement; Endoscopy; Surgical procedures, minimally invasive

Thursday, September 27, 2018 3:35 PM–5:05 PM Section on Motion Technology Abstract Presentations: 137. How do patients with predominant chronic neck pain experience cervical disc replacement? Results from a prospective study at 5 years follow-up

BACKGROUND CONTEXT Several studies have demonstrated that cervical total disc replacement (CTDR) is a safe and effective alternative to anterior cervical discectomy and fusion for the treatment of well-defined cervical pathologies. Nevertheless, data on some specific indications remain in short supply. PURPOSE To compare clinical and radiological outcomes of patients with preoperative predominant chronic neck pain (PCNP) to those without, 5 years after CTDR. STUDY DESIGN/SETTING Patients were from an observational, prospective and multicentric French study (involving eight centers). Exploratory analysis of CTDR patients with predominant chronic neck pain (VAS neck pain >50/100 & VAS neck pain > VAS arm pain) before the surgery, compared to the rest of the population. PATIENT SAMPLE The study enrolled 384 patients and is ongoing up to 10 years. Learning curve cases, patients with previous cervical surgery, patients with severely degenerated discs and work related injuries were not excluded. OUTCOME MEASURES Clinical outcomes (NDI 0-100%, VAS arm and neck pain 0-100 mm, SF-36) were completed prospectively by patients. Radiological outcomes included range of motion at index and adjacent levels, heterotopic ossifications (HO) according to Mehren-McAfee classification, adjacent segment degeneration according to Kellgren-Lawrence classification. Complications and subsurgery were reported. Patient satisfaction, medication consumption and employment status were also completed. METHODS The analysis considers patients treated with 1- or 2-level CTDR. PCNP patients were selected based on VAS pain (VAS neck pain > 50/100 & VAS neck pain > VAS arm pain) and duration of symptoms (>1 year). Mann-Whitney test was applied to compare data between groups and Fisher's exact test was applied to compare proportions. RESULTS For the PCNP group 47 patients were selected and 291 represents the group rest of population (RP). Mean age and mean operative duration were significantly higher for PCNP group. PCNP patients were more likely to be treated with 2-level. For VAS neck pain PCNP patients showed significantly higher improvement at 5-year compared to preoperative baseline (43.9 mm vs. 22.9; p CONCLUSIONS Patients with preoperative predominant chronic neck pain had similar patient-reported clinical and radiological outcomes with better improvement for VAS neck pain up to 5 years after surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Gaining insight into the complexity of pain in patients with haemophilia: State-of-the-art review on pain processing.

Despite the high prevalence of recurrent, constant and/or widespread pain in patients with haemophilia (PwH), there is an immense lack of studies examining the (patho)physiology of pain in this population. This contrasts to the bulk of literature in other pain conditions, such as osteoarthritis, low back pain or rheumatoid arthritis. Understanding the complexity of pain allows to better assess and manage pain. In PwH, the first priority is always to exclude bleeding as a cause of pain. An important next step in pain assessment is the evaluation of the predominant pain mechanism (ie nociceptive, neuropathic pain or altered central pain processing) as the treatment approach will be very different according to the underlying pain mechanism. Pain assessment should include both physiological and psychological components. This review summarizes the evidence regarding nociceptive, neuropathic and altered central pain processing in PwH and serves as a research agenda to prioritize pain research in PwH.

Tonic, Burst, Dorsal Root Ganglion, and High Frequency

The current environment of spinal cord stimulation is rapidly advancing, with new technologies and applications emerging constantly, allowing for more effective and individualized treatment of our patients. However, these new advances can be overwhelming for the practicing clinician, because there are no high-quality, head-to-head studies comparing these new technologies, making the clinician's choice a difficult one. High-level evidence already exists on the efficacy and safety of traditional tonic stimulation for the treatment of chronic refractory lower back with predominant limb pain. More recently, paresthesia-free high-frequency and burst stimulation was introduced, and has shown superiority over traditional stimulation for both chronic lower back and leg pain (Figure 1).1 Dorsal root ganglion stimulation is another novel form of neuromodulation that offers a highly targeted form of stimulation (Figure 2).2 Level I evidence now exists showing the superiority of both dorsal root ganglion and high-frequency stimulation over traditional stimulation.1,2 When attempting to choose between these different technologies, the main goal should be to achieve the best pain relief with minimal further interventions. Burst stimulation provides the option of alternating between tonic and paresthesia-free stimulation depending on patient preference and efficacy.3 High-frequency therapy is useful for patients who cannot tolerate paresthesia or have predominantly axial back pain. Dorsal root ganglion is particularly useful in covering areas that are hard to cover with conventional stimulation, such as the foot and groin. Overall, these different technologies provide drug-free, safe, and effective options for chronic pain.Figure 1: Burst spinal cord stimulation for limb and back pain. Reprinted with permission from Elsevier.3Figure 2: ACCURATE Study. Reprinted with permission.2 DRG indicates dorsal root ganglion; SCS, spinal cord stimulation.

Elastomeric Lumbar Total Disc Replacement: Clinical and Radiological Results With Minimum 84 Months Follow-Up.

Total lumbar disc replacement (TDR) devices have been designed to maintain motion, but both biomechanical and clinical data have indicated that a more controlled motion and additional load absorption in TDR would be beneficial. This work analyzed long-term results of an elastomeric disc (Physio-L) for degenerative lumbar conditions. This was a prospective, noncomparative, single-center clinical and radiological study. A total of 15 patients with predominant low back pain due degenerative disc disease received anterior total disc replacement with a Physio-L disc. Clinical outcomes were assessed both with a visual analog scale for pain and Oswestry Disability Index questionnaires. Radiological outcomes included implant failure, range of motion (ROM), facet degeneration, and adjacent level disease. Complication and reoperation rates were also recorded. The cases were assessed with a minimum follow-up of 84 months. A total of 15 patients were enrolled (20 TDRs)-10 single-level cases (L5S1) and 5 two-level cases (L4L5/L5S1). After 84 months, clinical outcomes scores still demonstrated significant improvement compared with baseline (P < .001). Mean visual analog scale scores dropped from 7.1 to 2.9, and the Oswestry Disability Index improved from 50 to 16. No disc has experienced migration or breakage. The average range of motion value went from a baseline of 12.0° to 13.3° at 12 months, and at the final follow-up it decreased to 9.9°. Regarding the double-level cases, 3 of 5 (60%) had adverse events; just 1 single-level (10%) had adverse events. At final follow-up, radiological signs of facet degeneration were present in 7 of 15 patients (47%) but with only 1 of 15 (6.7%) symptomatic. Two patients (13%) required surgery at the adjacent level. At the 84-month follow-up, 16 of 18 prostheses (89%) were still active (2 revised to fusion and 2 were lost to follow-up). The long-term follow-up data shows satisfactory clinical results for the use of Physio-L elastomeric TDR in the treatment of degenerative disc disease. Studies with bigger cohorts are needed to replicate results and add new information regarding other details.

Techirghiol Balneal and Rehabilitation Sanatorium – one year study on patients’ profile

Introduction: The Balneal and Rehabilitation Sanatorium of Techirghiol gained its fame over the years, due to the good therapeutic results and the great number of patients treated here with natural cure factors – salted water and sapropelic mud of Techirghiol Lake. Aim: to analyse the profile of patients admitted in Techirghiol Balneal and Rehabilitation Sanatorium; Material and method: we analysed a plot of six thousand two hundred eighty one patients from ten thousand nine hundred fifty seven patients admitted in the sanatorium within one year. All patients underwent the cure according to the protocols of TBRS. After the initial clinical examination, a questionnaire containing more than 50 items, conceived by the authors, which includes personal data, medical history, comorbidities, stress level, home physical activity, were filled in. All patients were informed about the study and agreed to participate. Data from the questionnaires were statistically processed and plotted. Twenty young residents and six final year students in medicine worked together with the authors to process the huge amount of data entry and information. Conclusions: data obtained after processing of the questionnaires show that osteoarthritis is the predominant pathology and pain the main symptom in patients admitted to cure. The patient is: ‐ rather women (64%) than men (36%); ‐ rather 50 – 59 y.o. (31%) or 60 – 69 y.o. (29%) than 40 – 49 y.o. (15%) or more than 70 y.o. (17%), ‐ rather retired (53%) than active (43%), ‐ rather overweight (44%) than obese (27%) or normal weight (24%); ‐ rather with comorbidities (37% one, 34% polipatology) than without (29%), ‐ no smokers and urban citizen Acknowledgement: other different parts of this study were presented by the authors in other conferences. Authors thanks to the young physicians and students for their contribution to this study.

Burst or High-Frequency (10 kHz) Spinal Cord Stimulation in Failed Back Surgery Syndrome Patients With Predominant Back Pain: One Year Comparative Data

Burst and 10 kHz spinal cord stimulation (SCS) demonstrated improvement for failed back surgery syndrome (FBSS) with predominant, refractory back pain. Here, we report the long-term follow-up of a previously published study comparing the safety and efficacy of burst vs. 10 kHz SCS for predominant back pain (70% of global pain) of FBSS patients. This comparative, observational study extended the follow-up period up to 20 months evaluating both SCS modalities. Pain intensity (visual analog scale [VASB , VASL ]), functional capacity (Pittsburgh Sleep Quality Index [PSQI]; depression (Beck Depression Inventory [BDI]), stimulation parameters and hardware and/or stimulation associated adverse events were recorded and analyzed over time. Overall VASB (t1,12 = 66.76, p < 0.001) and VASL (t1,12 = 4.763, p < 0.049; p < 0.001) declined over time. Burst significantly decreased VASB by 87.5% (±17.7) (mean 8 ± 0.76 to 1 ± 1.41; t1 =12.3, p < 0.001), and 10 kHz significant decreased VASB by 54.9% (±44) (mean 8 ± 0.63 to 3.5 ± 3.27; t1 =3.09, p = 0.027). No significant differences for between SCS types were revealed (t1 =1.75, p = 0.13). VASL was significantly suppressed for burst (burst: 3.6 ± 1.59 to 1.5 ± 1.06; t1 = 3.32, p = 0.013). A significant effect of time was found for functional outcome with no significant differences between SCS types (PSQI: t1,12 = 8.8, p = 0.012; and BDI: t1 = 53.3, p < 0.001). No stimulation/hardware-related complications occurred. Long-term data of this comparative study suggests that burst responsiveness was superior to 10 kHz in our small-scale cohort, thus a larger, randomized-controlled comparative study design is highly recommended.

Incidence and predictive factors of spinal cord stimulation treatment after lumbar spine surgery

IntroductionSpinal cord stimulation (SCS) is recommended for the treatment of postsurgical chronic back and leg pain refractory to other treatments. We wanted to estimate the incidence and predictive factors of SCS treatment in our lumbar surgery cohort.Patients and methodsThree questionnaires (a self-made questionnaire, the Oswestry Low Back Pain Disability Questionnaire, and the Beck Depression Inventory) were sent to patients aged 18–65 years with no contraindications for the use of SCS, and who had undergone non-traumatic lumbar spine surgery in the Oulu University Hospital between June 2005 and May 2008. Patients who had a daily pain intensity of ≥5/10 with predominant radicular component were interviewed by telephone.ResultsAfter exclusions, 814 patients remained in this cohort. Of those, 21 patients had received SCS by the end of June 2015. Fifteen (71%) of these received benefit and continued with the treatment. Complications were rare. The number of patients who replied to the postal survey were 537 (66%). Eleven of them had undergone SCS treatment after their reply. Features predicting SCS implantation were daily or continuous pain, higher intensities of pain with predominant radicular pain, more severe pain-related functional disability, a higher prevalence of depressive symptoms, and reduced benefit from pain medication. The mean waiting time was 65 months (26–93 months). One hundred patients were interviewed by telephone. Fourteen seemed to be potential SCS candidates. From the eleven patients who underwent SCS after responding to the survey, two were classified as potential candidates in the phone interview, while nine were other patients. Twelve patients are still waiting for treatment to commence.ConclusionIn our region, the SCS treatment is used only for very serious pain conditions. Waiting time is too long and it may be the reason why this treatment option is not offered to all candidates.

59 - Outcome of Fusion vs Nonoperative Care in Degenerative Lumbar Scoliosis in Relation to Preoperative Chronic Pain Pattern and Disability: a Registry Study of 6796 Patients

BACKGROUND CONTEXT: Patients with degenerative lumbar scoliosis (DS) and predominant back pain (PBP) have been shown to have an inferior outcome after surgery. Studies comparing outcome according to preoperative pain predominance and treatment received are lacking.

What Are the Predictors of Altered Central Pain Modulation in Chronic Musculoskeletal Pain Populations? A Systematic Review

Background: Altered central pain modulation is the predominant pain mechanism in a proportion of chronic musculoskeletal pain disorders and is associated with poor outcomes. Although existing studies predict poor outcomes such as persistent pain and disability, to date there is little consensus on what factors specifically predict altered central pain modulation. Objectives: To review the existing literature on the predictive factors specifically for altered central pain modulation in musculoskeletal pain populations. Study Design: This is a systematic review in accordance with supplemented PRISMA guidelines. Methods: A systematic search was performed by 2 mutually blinded reviewers. Relevant articles were screened by title and abstract from Medline, Embase, PubMed, CINAHL, and Web of Science electronic databases. Alternative sources were also sought to locate missed potential articles. Eligibility included studies published in English, adults aged 18 to 65, musculoskeletal pain, baseline measurements taken at the pre-morbid or acute stage, &gt; 3-month follow-up time after pain onset, and primary outcome measures specific to altered central pain modulation. Studies were excluded where there were concurrent diseases or they were non-predictive studies. Risk of bias was assessed using the quality in prognostic studies (QUIPS) tool. Study design, demographics, musculoskeletal region, inclusion/ exclusion criteria, measurement timelines, predictor and primary outcome measures, and results were extracted. Data were synthesized qualitatively and strength of evidence was scored using the grading of recommendations, assessment, development, and evaluations (GRADE) scoring system. Results: Nine eligible articles were located, in various musculoskeletal populations (whiplash, n = 2; widespread pain, n = 5; temporomandibular disorder, n = 2). Moderate evidence was found for 2 predictive factors of altered central pain modulation: 1) high sensory sensitivity (using genetic testing or quantitative sensory tests), and 2) psychological factors (somatization and poor self-expectation of recovery), at a pre-morbid or acute stage baseline. Limitations: At the times of the article publications, the current definitions and clinical guidelines for identifying altered central pain modulation were not yet available. Careful interpretation of the information provided using current knowledge and published guidelines was necessary to extract information specific to altered central pain modulation in some of the studies, avoiding unwarranted assumptions. Conclusions: Premorbid and acute stage high sensory sensitivity and/or somatization are the strongest predictors of altered central pain modulation in chronic musculoskeletal pain to date. This is the first systematic review specifically targeting altered central pain modulation as the primary outcome in musculoskeletal pain populations. Early identification of people at risk of developing chronic pain with altered central pain modulation may guide clinicians in appropriate management, diminishing the burden of persistent pain on patients and heath care providers alike. Systematic Review Registration no.: PROSPERO 2015:CRD42015032394

Identifying predictors for postoperative clinical outcome in lumbar spinal stenosis patients using smart-shoe technology

BackgroundApproximately 33% of the patients with lumbar spinal stenosis (LSS) who undergo surgery are not satisfied with their postoperative clinical outcomes. Therefore, identifying predictors for postoperative outcome and groups of patients who will benefit from the surgical intervention is of significant clinical benefit. However, many of the studied predictors to date suffer from subjective recall bias, lack fine digital measures, and yield poor correlation to outcomes.MethodsThis study utilized smart-shoes to capture gait parameters extracted preoperatively during a 10 m self-paced walking test, which was hypothesized to provide objective, digital measurements regarding the level of gait impairment caused by LSS symptoms, with the goal of predicting postoperative outcomes in a cohort of LSS patients who received lumbar decompression and/or fusion surgery. The Oswestry Disability Index (ODI) and predominant pain level measured via the Visual Analogue Scale (VAS) were used as the postoperative clinical outcome variables.ResultsThe gait parameters extracted from the smart-shoes made statistically significant predictions of the postoperative improvement in ODI (RMSE =0.13, r=0.93, and p<3.92×10−7) and predominant pain level (RMSE =0.19, r=0.83, and p<1.28×10−4). Additionally, the gait parameters produced greater prediction accuracy compared to the clinical variables that had been previously investigated.ConclusionsThe reported results herein support the hypothesis that the measurement of gait characteristics by our smart-shoe system can provide accurate predictions of the surgical outcomes, assisting clinicians in identifying which LSS patient population can benefit from the surgical intervention and optimize treatment strategies.

Motion preservation following total lumbar disc replacement at the lumbosacral junction: a prospective long-term clinical and radiographic investigation

Background ContextTotal lumbar disc replacement (TDR) intends to avoid fusion-related negative side effects by means of motion preservation. Despite their widespread use, the adequate quality and quantity of motion, as well as the correlation between radiographic data with the patient's clinical symptomatology, remains to be established. Long-term data are lacking in particular. PurposeThis study aimed to perform a clinical and radiographic long-term investigation following TDR with special emphasis on motion preservation assessment and to establish any potential correlation with patient-reported outcome parameters. Study Design/SettingA prospective, single-center, clinical, and radiological investigation following TDR with ProDisc II (Synthes, Paoli, PA, USA) was carried out. Patient SamplePatients with a minimum 5-year follow-up (FU) after TDR performed for the treatment of intractable and predominant (≥80%) axial low back pain resulting from single-level degenerative disc disease without instabilities or deformities at the lumbosacral junction (L5–S1) comprised the sample. Outcome MeasuresVisual analogue scale (VAS), Oswestry Disability Index (ODI), and patient satisfaction rates (three-scale outcome rating), range of motion (ROM) at the index- and cranially adjacent level as well as segmental lumbar lordosis (SLL) and global lumbar lordosis (GLL) were the outcome measures. MethodsAll data were acquired within the framework of an ongoing prospective clinical trial. Patients were examined preoperatively, 3, 6, and 12 months postoperatively, and annually thereafter. X-rays were performed in antero-posterior and lateral views as well as functional flexion/extension images. Radiological examinations included ROM at the index and cranially adjacent level as well as SLL and GLL. X-ray measurements were correlated with the clinical outcome parameters. A longitudinal analysis was performed between baseline data with those from the early (3–6 months), mid- (12–24 months), and late FU stages (≥5 years). ResultsResults from 51 patients with a mean FU of 7.8 years (range 5.0–13.3 years) were available for the final analysis. X-ray measurements revealed a maintained mobility with a trend toward gradually declining ROM values. Although no statistically significant difference in ROM was detected between the preoperative and early FU (6.8° vs. 5.8°, p=.1), a further reduction in ROM became statistically significant at the mid- and final FU, with mean ROM of 5.2° and 4.4°, respectively (p<.001).Global lumbar lordosis increased from 48.8° to 54.4° (p<.0001) which was attributed to a lordotic shift from 18.2° to 28.0° at the index segment (p<.00001) and which was positively correlated with the applied implant lordosis (p<.05). A compensatory reduction of lordosis was observed at the cranially adjacent segment (p<.0001). The mobility of the cranially adjacent level remained unchanged (p>.05).The clinical outcome scores (VAS, ODI) revealed a significant improvement from baseline levels (p<.05). The reduction in ROM was not negatively correlated with the patient's clinical symptomatology (p>.05). ConclusionThe present data reveal an increased GLL resulting from a lordotic shift of the index segment, which was strongly correlated with the applied implant lordosis. This lordotic shift was accompanied by a compensatory reduction of lordosis at the cranially adjacent segment.A gradual and statistically significant decline of the device mobility was noted over time which, however, did not negatively impact the patient's clinical symptomatology.Although the present long-term investigation provides additional insight into longitudinal radiographic changes and their influence on the patient's clinical symptomatology following TDR, the adequate quality and quantity of motion with artificial motion-preserving implants remains to be established, which will aid in defining more refined treatment concepts for both fusion and motion preserving techniques alike.

Burst Spinal Cord Stimulation Increases Peripheral Antineuroinflammatory Interleukin 10 Levels in Failed Back Surgery Syndrome Patients With Predominant Back Pain

Burst spinal cord stimulation (SCS) has been reported to reduce back pain and improve functional capacity in Failed Back Surgery Syndrome (FBSS). However, its mechanism of action is not completely understood. Systemic circulating cytokines have been associated with the development of chronic back pain. This prospective, feasibility study enrolled 12 refractory FBSS patients with predominant back pain (70% of overall pain) suitable for Burst SCS. Back and leg pain intensity (back pain [VASB ]/leg pain [VASL ]), functional capacity (sleep quality [PSQI]), depressive symptoms (BDI), body weight, stimulation parameters, and plasma levels of pro-inflammatory (Il-1b; TNF; HMGB1)/anti-inflammatory (Il-10) cytokines were collected at baseline and after three months of Burst SCS and compared to healthy controls. Pain intensity (pre VASB : 8.25 ± 0.75 vs. post 1.42 ± 1.24) and functional capacity (PSQI: pre 7.92 ± 3.92 vs. post 3.42 ± 1.24; BDI: pre 20.83 ± 3.56 vs. post 10.92 ± 0.75) significantly improved compared to baseline. Pro-inflammatory HMGB1 remained unchanged (preburst: 3.35 ± 3.25 vs. postburst: 3.78 ± 3.83 ng/mL; p = 0.27; W = -30) versus the HC group (2.53 ± 2.6 ng/mL; p = 0.47; U = 59), while anti-inflammatory IL-10 levels were significantly elevated after burst SCS as compared to baseline (preburst 12.54 ± 22.95 vs. postburst 43.16 ± 74.71 pg/mL; p = 0.03; W = -48) and HC group (HC: 7.03 ± 11.6 vs. postburst 43.16 ± 74.71 pg/mL; p = 0.03; W = -48; p = 0.04). Baseline preburst IL-10 values and preburst VASB significantly correlated (Spearman correlation r = -0.66; p = 0.05; 95 CI -0.86 to -0.24), while correlation was not significant between postburst IL-10 values and postburst VASB (Spearman correlation r = -0.49; p = 0.18; 95 CI -0.83 to -0.15). Postburst IL-10 values correlated significantly with postburst PSQI scores (Spearman correlation r = -0.66; p = 0.05; 95 CI -0.86 to -0.24), while no correlation was found between preburst and postburst changes related to the BDI. Burst SCS increased systemic circulating anti-inflammatory IL-10, improved FBSS back pain and back pain associated co-morbidities like disrupted sleep architecture and depressive symptoms in FBSS patients. Thus, suggesting a possible relationship between burst SCS and burst-evoked modulation of peripheral anti-inflammatory cytokine IL-10 in chronic back pain.

Prospective Audit of a Pathway for In-Patient Pain Management of Chronic Abdominal Pain: A Novel and Cost-Effective Strategy.

Unexplained abdominal pain is a common cause of hospital admission and utilizes significant resource. Current in-patient pain management of acute exacerbation of chronic abdominal pain is primarily directed at pharmacological and psychological management strategies in this group of complex patients. We adopted a novel approach that proved to be both clinically effective and cost-effective. Adult patients admitted to a surgical ward with acute exacerbation of chronic abdominal pain referred to in-patient pain management were prospectively audited over a two-year period at a single tertiary centre. Management strategy focused on a somatic source as the predominant pain generator. Patients were offered ultrasound-guided trigger point injection with steroids within 48 hours of referral and were discharged when pain control was achieved. Subsequent care by the pain physician included targeted treatment of somatic component (repeated trigger point injection with steroids or pulsed radiofrequency treatment of trigger points). We audited 43 patients referred to the inpatient pain management service over a two-year period. Four patients refused to undergo the diagnostic trigger point injection. Three patients with active visceral disease had a transient response to the injection. Thirty-six patients were diagnosed with abdominal myofascial pain syndrome, and two-thirds of these patients were discharged home within 36 hours of the intervention. Abdominal myofascial pain syndrome is a poorly recognized cause of chronic abdominal pain, especially in patients with a past history of visceral inflammation. The novel strategy resulted in a significant reduction in opioid consumption, length of stay, and readmission rate.

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

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