Functional Connectivity Magnetic Resonance Imaging Sequences in Patients With Postsurgical Persistent Spinal Pain Syndrome Type 2 With Implanted Spinal Cord Stimulation Systems: A Safety, Feasibility, and Validity Study.

BACKGROUND: Chronic pain has been associated with alterations in brain connectivity, both within networks (regional) and between networks (cross-network connectivity). Functional connectivity (FC) data on chronic back pain are limited and based on heterogeneous pain populations. Patients with postsurgical persistent spinal pain syndrome (PSPS) type 2 are good candidates for spinal cord stimulation (SCS) therapy. We hypothesize that 1) FC magnetic resonance imaging (fcMRI) scans can be safely obtained in patients with PSPS type 2 with implanted therapeutic SCS devices and that 2) their cross-network connectivity patterns are altered and involve emotion and reward/aversion functions. MATERIALS AND METHODS: Resting-state (RS) fcMRI (rsfcMRI) scans were obtained from nine patients with PSPS type 2 implanted with therapeutic SCS systems and 13 age-matched controls. Seven RS networks were analyzed, including the striatum. RESULTS: Cross-network FC sequences were safely obtained on a 3T MRI scanner in all nine patients with PSPS type 2 with implanted SCS systems. FC patterns involving emotion/reward brain circuitry were altered as compared with controls. Patients with a history of constant neuropathic pain, experiencing longer therapeutic effects of SCS, had fewer alterations in their connectivity patterns. CONCLUSIONS: To our knowledge, this is the first report of altered cross-network FC involving emotion/reward brain circuitry in a homogeneous population of patients with chronic pain with fully implanted SCS systems, on a 3T MRI scanner. All rsfcMRI studies were safe and well tolerated by all nine patients, with no detectable effects on the implanted devices.

MR Neurography of Lumbosacral Plexus: Incremental Value Over XR, CT, and MRI of L Spine With Improved Outcomes in Patients With Radiculopathy and Failed Back Surgery Syndrome.

BACKGROUND: Lower back pain is often evaluated using magnetic resonance imaging (MRI) and conventional imaging, which provide incomplete information about the etiology of pain and lead to less than optimal management. HYPOTHESIS: MR neurography (MRN) of the lumbosacral (LS) plexus renders a more accurate diagnosis, alters the management strategy, and clinical outcomes of radiculopathy or failed back surgery Syndrome (FBSS) patients when compared to the conventional imaging modalities. STUDY TYPE: Retrospective, cross-sectional. POPULATION: A total of 356 patients (mean age 65.8 ± 12.3; 48.9% female) from single university hospital over 6 years with MRN of LS plexus were included from a cohort of 14,775 total patients with lumbar spine MR imaging. ASSESSMENT: Conventional imaging obtained before and after MRN of LS plexus was reevaluated and categorized into three levels based on extent of imaging findings' correlation to presenting clinical symptoms (contributory levels). Clinical notes were reviewed for changes in ordering provider's recommended management and subsequent patients' symptom level pre-MRN to post-MRN. FIELD STRENGTH/SEQUENCE: A 5 T and 3.0 T. T1-weighted (T1W), T2-weighted (T2W), short T1 inversion recovery (STIR), T1 turbo spin echo (T1 TSE), T2 spectral attenuated inversion recovery (T2 SPAIR). STATISTICAL TESTS: Chi-squared test. Statistical significance was set at P < 0.05. RESULTS: A total of 356 total patients (174 females) with mean age ± SD was 65.8 ± 12.3 years, 4.2% of patients imaged with lumbar spine MRI. Definitely contributory studies among X-rays, computed tomography, MRI, and MRN were 3 of the 129 (2.3%), 3 of the 48 (6.2%), 35 of the 184 (19.0%), and 283 of the 356 (79.8%), respectively. Pre-MRN vs. post-MRN led to change in recommendation in 219 of the 356 (61.5%) patients and 71 of the 99 (71.7%) patients had improved symptoms. CONCLUSION: MRN of the LS plexus can provide more corroborative image findings for symptom correlation compared to other imaging modalities for accurate diagnosis, effects patient management and leads to positive clinical outcomes in a small subset of patients with radiculopathy or FBSS. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 5.

The Correlation of Epidural Fibrosis with Epiduroscopic and Radiologic Imaging for Chronic Pain after Back Surgery.

BACKGROUND: Chronic low back pain is observed frequently after lumbar spinal surgery. Epidural fibrosis has been implicated in the etiology of persistent pain after back surgery. The incidence of epidural fibrosis increases as the number and extent of spinal surgery increases. Epidural fibrosis can be detected by conventional radiologic methods [e.g., lumbosacral magnetic resonance imaging (MRI) with gadolinium], but these methods are insufficient to reveal the presence of epidural adhesions. Imaging of the epidural cavity using an epiduroscope is one of the best methods for visualizing the spinal cavity without damaging anatomic structures. OBJECTIVES: To evaluate the correlation between the type and number of surgery and the degree of epidural fibrosis and to compare epidural fibrosis in epiduroscopic and MRI findings in patients with failed back surgery syndrome (FBSS). STUDY DESIGN: A prospective trial. SETTING: A university hospital. METHODS: This study included 61 patients with persistent low back pain and/or radicular pain for at least 6 months, despite lumbar surgery and conservative treatment, and who accepted epiduroscopic imaging. All patients were evaluated in a physical examination using a visual analog scale (VAS) per the elapsed time after surgery. The patients were divided into 3 groups according to the number and type of surgeries. Epidural fibrosis was rated using MRI with gadolinium and epiduroscopy. RESULTS: When the relationship between admission symptoms and epidural fibrosis was evaluated, MRI findings of fibrosis were found to be significantly higher in all patients with both lumbar and radicular pain symptoms at the confidence level of 95% (P = 0.001). The degree of fibrosis detected using epiduroscopy was grade 1 and 2 in almost all patients who presented with low back pain only, only radicular pain, or only distal paresthesia (P = 0.001). In the correlation analysis between the duration of the postoperative period (4.13 ± 2.97 years) and the degree of fibrosis detected using MRI and epiduroscopy, a statistically significant relationship was found at the confidence level of 95% (P < 0.05). As the number and extent of spinal surgeries increased, the incidence of MRI fibrosis increased, which is compatible with the literature (P = 0.001) There was a statistically significant relationship between the degree of fibrosis as detected using MRI and epiduroscopy at the confidence level of 95% (P < 0.05). Differently, we observed that 6 patients had grade 1 fibrosis as diagnosed using epiduroscopy, whereas none had fibrosis on MRI. LIMITATIONS: We did not have a control group. Further studies are required to demonstrate the relevance of these 2 imaging techniques (epiduroscopy and MRI) in terms of detecting epidural fibrosis in patients with FBSS.  CONCLUSIONS: Epiduroscopic imaging seems to be more sensitive than MRI in detecting grade I epidural fibrosis in patients with FBSS. Thus, the possibility of low-grade epidural fibrosis as a source of pain after back surgery, should be kept in mind in normally reported MRIs. Treatment should be planned accordingly.

Placement of Surgical Spinal Cord Stimulation Leads Using Spinal Process Splitting Laminotomy: Technical Note.

OBJECTIVE: Spinal cord stimulation has become an established method within the therapy of chronic pain allowing for significant pain relief. Surgical leads usually must be implanted via a surgical procedure involving unilateral or bilateral muscle detachment and partial laminectomy. METHODS: We present the application of a novel minimal invasive microsurgical approach for lead placement, which combines the beneficial advantages of anatomic midline lead placement while preserving the midline structures, avoiding muscle detachments, and thus ensuring spinal stability: spinal process splitting laminotomy. CONCLUSIONS: The spinal process splitting laminotomy technique can be successfully applied to introduce the surgical leads for spinal cord stimulation.

The dimensions of "failed back surgery syndrome": what is behind a label?

BACKGROUND: The term failed back surgery syndrome (FBSS) has been criticized for being too unspecific and several studies have shown that a variety of conditions may underlie this label. The aims of the present study were to describe the specific symptoms and to investigate the primary and secondary underlying causes of FBSS in a contemporary series of patients who had lumbar spinal surgery before. METHODS: We used a multilevel approach along three different axes defining symptomatic, morphological, and functional pathology dimensions. RESULTS: Within the study period of 3 years, a total of 145 patients (74 f, 71 m, mean age 51a, range 32-82a) with the external diagnosis of FBSS were included. Disk surgery up to 4 times and surgery for spinal stenosis up to 3 times were the commonest index operations. Most often, the patients complained of low back pain (n = 126), pseudoradicular pain (n = 54), and neuropathic pain (n = 44). Imaging revealed osteochondrosis (n = 61), spondylarthrosis (n = 48), and spinal misalignment (n = 32) as the most frequent morphological changes. The majority of patients were assigned at least to two different symptomatic subcategories and morphological subcategories, respectively. According to these findings, one or more functional pathologies were assigned in 131/145 patients that subsequently enabled a specific treatment strategy. CONCLUSIONS: FBSS has become rather a vague and imprecisely used generic term. We suggest that it should be avoided in the future both with regard to its partially stigmatizing connotation and its inherent hindering to provide individualized medicine.

Effects of spinal cord stimulation on voxel-based brain morphometry in patients with failed back surgery syndrome.

OBJECTIVE: Despite the clinical effectiveness of Spinal Cord Stimulation (SCS), potential structural brain modifications have not been explored. Our aim was to identify structural volumetric changes during subsensory SCS, in patients with Failed Back Surgery Syndrome (FBSS). METHODS: In this cohort study, twenty-two FBSS patients underwent a magnetic resonance imaging protocol before SCS and 3 months after SCS. Clinical parameters were correlated with volumetric changes, calculated with voxel-based morphometry. RESULTS: After 3 months, a significant volume decrease was found in the inferior frontal gyrus, precuneus, cerebellar posterior lobe and middle temporal gyrus. Significant increases were found in the inferior temporal gyrus, precentral gyrus and the middle frontal gyrus after SCS. Additionally, significant increases in volume of superior frontal and parietal white matter and a significant decrease in volume of white matter underlying the premotor/middle frontal gyrus were revealed after SCS. A significant correlation was highlighted between white matter volume underlying premotor/middle frontal gyrus and leg pain relief. CONCLUSIONS: This study revealed for the first time that SCS is able to induce volumetric changes in gray and white matter, suggesting the reversibility of brain alterations after chronic pain treatment. SIGNIFICANCE: Volumetric brain alterations are observable after 3 months of subsensory SCS in FBSS patients.

Magnetic Resonance Imaging Exploration of the Human Brain During 10 kHz Spinal Cord Stimulation for Failed Back Surgery Syndrome: A Resting State Functional Magnetic Resonance Imaging Study.

INTRODUCTION: Apart from the clinical efficacy of high frequency spinal cord stimulation at 10 kHz, the underlying mechanism of action remains unclear. In parallel with spinal or segmental theories, supraspinal hypotheses have been recently proposed. In order to unveil hidden altered brain connectome patterns, a resting state functional magnetic resonance imaging (rsfMRI) protocol was performed in subjects routinely treated for back and/or leg pain with high-frequency spinal cord stimulation (HF-SCS) HF-SCS at 10 kHz. METHODS: RsfMRI imaging was obtained from ten patients with failed back surgery syndrome who were eligible for HF-SCS at 10 kHz. Specifically-chosen regions of interest with different connectivity networks have been investigated over time. Baseline measurements were compared with measurements after 1 month and 3 months of HF-SCS at 10 kHz. Additionally, clinical parameters on pain intensity, central sensitization, pain catastrophizing, and sleep quality were correlated with the functional connectivity strengths. RESULTS: The study results demonstrate an increased connectivity over time between the anterior insula (affective salience network) and regions of the frontoparietal network and the central executive network. After 3 months of HF-SCS, the increased strength in functional connectivity between the left dorsolateral prefrontal cortex and the right anterior insula was significantly correlated with the minimum clinically important difference (MCID) value of the Pittsburgh sleep quality index. CONCLUSION: These findings support the hypothesis that HF-SCS at 10 kHz might influence the salience network and therefore also the emotional awareness of pain.

Magnetic Resonance Neurography of the Lumbosacral Plexus in Failed Back Surgery Syndrome.

STUDY DESIGN: Retrospective clinical case series. OBJECTIVE: To study the role of magnetic resonance neurography (MRN) of the lumbosacral plexus in management of patients with failed back surgery syndrome (FBSS). SUMMARY OF BACKGROUND DATA: FBSS is one of the major problems in health care, affecting up to 40% of patients after spine surgery. To date, no imaging modality has been used to effectively classify nerve compression, because nerve injuries are challenging to detect on conventional lumbar spine magnetic resonance imaging (MRI). To our knowledge, no previous studies have addressed the use of MRN in FBSS or compared it to lumbar spine MRI. METHODS: From 203 consecutive 3 T MRN studies of lumbosacral plexus in 1 year, 12% (25/203) presented as FBSS. Demographic data, number of previous lumbar MRIs and their findings, MRN findings, interval between MRI and MRN, pre-and post-MRN diagnosis, pain levels, and treatments were recorded. Changes in diagnosis, treatment, and outcomes after MRN were determined. RESULTS: The final sample of 25 patients had a mean age 62 ±â€Š15 and male to female ratio 1:1.08. Approximately 88% (22/25) had previous lumbar MRI, of which 27% had 3 or more. Most common imaging findings were neuroforaminal stenosis 22.6% (7/31) on MRI and neuropathy 22.9% (19/83) on MRN. Mean interval between MRI and MRN was 13.9 ±â€Š28.3 months. Lumbar MRIs were inconclusive in 36% (8/22). MRN detected 63% (52/83) more findings and changed the diagnosis and treatment in 12% and 48% of FBSS cases, respectively. Favorable outcomes were recorded in 40% to 67% of patients following MRN-guided treatments. CONCLUSION: FBSS is a complex problem and MRN of lumbosacral plexus impacts its management by better directing source of symptoms. LEVEL OF EVIDENCE: 4.

Effect of Pain Neuroscience Education Combined With Cognition-Targeted Motor Control Training on Chronic Spinal Pain: A Randomized Clinical Trial.

Importance: Effective treatments for chronic spinal pain are essential to reduce the related high personal and socioeconomic costs. Objective: To compare pain neuroscience education combined with cognition-targeted motor control training with current best-evidence physiotherapy for reducing pain and improving functionality, gray matter morphologic features, and pain cognitions in individuals with chronic spinal pain. Design, Setting, and Participants: Multicenter randomized clinical trial conducted from January 1, 2014, to January 30, 2017, among 120 patients with chronic nonspecific spinal pain in 2 outpatient hospitals with follow-up at 3, 6, and 12 months. Interventions: Participants were randomized into an experimental group (combined pain neuroscience education and cognition-targeted motor control training) and a control group (combining education on back and neck pain and general exercise therapy). Main Outcomes and Measures: Primary outcomes were pain (pressure pain thresholds, numeric rating scale, and central sensitization inventory) and function (pain disability index and mental health and physical health). Results: There were 22 men and 38 women in the experimental group (mean [SD] age, 39.9 [12.0] years) and 25 men and 35 women in the control group (mean [SD] age, 40.5 [12.9] years). Participants in the experimental group experienced reduced pain (small to medium effect sizes): higher pressure pain thresholds at primary test site at 3 months (estimated marginal [EM] mean, 0.971; 95% CI, -0.028 to 1.970) and reduced central sensitization inventory scores at 6 months (EM mean, -5.684; 95% CI, -10.589 to -0.780) and 12 months (EM mean, -6.053; 95% CI, -10.781 to -1.324). They also experienced improved function (small to medium effect sizes): significant and clinically relevant reduction of disability at 3 months (EM mean, -5.113; 95% CI, -9.994 to -0.232), 6 months (EM mean, -6.351; 95% CI, -11.153 to -1.550), and 12 months (EM mean, -5.779; 95% CI, -10.340 to -1.217); better mental health at 6 months (EM mean, 36.496; 95% CI, 7.998-64.995); and better physical health at 3 months (EM mean, 39.263; 95% CI, 9.644-66.882), 6 months (EM mean, 53.007; 95% CI, 23.805-82.209), and 12 months (EM mean, 32.208; 95% CI, 2.402-62.014). Conclusions and Relevance: Pain neuroscience education combined with cognition-targeted motor control training appears to be more effective than current best-evidence physiotherapy for improving pain, symptoms of central sensitization, disability, mental and physical functioning, and pain cognitions in individuals with chronic spinal pain. Significant clinical improvements without detectable changes in brain gray matter morphologic features calls into question the relevance of brain gray matter alterations in this population. Trial Registration: clinicaltrials.gov Identifier: NCT02098005.

Segmental Spinal Myoclonus Complicating Lumbar Transforaminal Epidural Steroid Injection.

OBJECTIVE: Lumbar transforaminal epidural steroid injection is commonly used for treating lumbar radicular pain. We report a case of segmental spinal myoclonus that developed during lumbar transforaminal epidural injection with local anesthetic and steroid. CASE REPORT: A 58-year-old woman with failed back surgery syndrome presented with low back and right L3 and L4 radicular pain. As she had responded well previously to diagnostic selective nerve root injection with local anesthetic at the right L3 and L4 levels, lumbar transforaminal epidural steroid injection at the same levels was scheduled. During injection of ropivacaine and triamcinolone at the right L3-4 intervertebral foramen, she complained of back pain and immediately developed involuntary contraction of her right hip. The procedure was terminated. No new neurological deficit was detected when she was examined 15 minutes after the procedure. There were no abnormalities from blood tests and magnetic resonance imaging of the lower thoracic and lumbar spine. A neurologist subsequently made the clinical diagnosis of segmental spinal myoclonus. The myoclonus improved over 1 month and eventually resolved completely. CONCLUSIONS: Segmental spinal myoclonus is a rare complication after lumbar transforaminal epidural steroid and local anesthetic injection. Pain physicians should be aware of this potential complication.

Failed back surgery syndrome: a new strategy by the epidural injection of MESNA.

PURPOSE: Evaluate the efficacy and safety of MESNA (sodium 2-mercaptoethanesulfonate) injection into the epidural space in the FBSS. METHODS: We designed a prospective phase II longitudinal study. Six consecutive patients were enrolled. Patients underwent one peridural injection per week for 3 weeks. NRS and ODI were investigated before and 48 h after injections, and at 1 week, 1 month and 2 months after the last procedures. Opioids intake is investigated before procedures and 1 week, 1 month and 3 months after the last procedures. Lumbosacral MRI is performed before the first procedure, at the end and 3 months after the last procedures. RESULTS: From baseline, at 3 months, NRS in standing, sitting and lying position improved, respectively, of 34.29, 30.56 and 26.47%; ODI improved of 20.3%; the average decrease in morphine intake was 20.54%. No difference in MR images was found. Conclusions Our preliminary results suggest that MESNA might be an efficacy alternative to common practice.

Increasing Rates of Imaging in Failed Back Surgery Syndrome Patients: Implications for Spinal Cord Stimulation.

BACKGROUND: Failed back surgery syndrome (FBSS) has a high incidence following spinal surgery, is notoriously refractory to treatment, and results in high health care utilization. Spinal cord stimulation (SCS) is a well-accepted modality for pain relief in this population; however, until recently magnetic resonance imaging (MRI) was prohibited due to risk of heat conduction through the device. OBJECTIVES: We examined trends in imaging use over the past decade in patients with FBSS to determine its impact on health care utilization and implications for patients receiving SCS. STUDY DESIGN: Retrospective. SETTING: Inpatient and outpatient sample. METHODS: We identified patients from 2000 to 2012 using the Truven MarketScan database. Annual imaging rates (episodes per 1000 patient months) were determined for MRI, computed tomography (CT) scan, x-ray, and ultrasound. A multivariate Poisson regression model was used to determine imaging trends over time, and to compare imaging in SCS and non-SCS populations. RESULTS: A total of 311,730 patients with FBSS were identified, of which 5.17% underwent SCS implantation (n = 16,118). The median (IQR) age was 58.0 (49.0 - 67.0) years. Significant increases in imaging rate ratios were found in all years for each of the modalities. Increases were seen in the use of CT scans (rate ratio [RR] = 3.03; 95% confidence interval [CI]: 2.79 - 3.29; P < 0.0001), MRI (RR = 1.73; 95% CI: 1.61 - 1.85; P < 0.0001), ultrasound (RR = 2.00; 95% CI: 1.84 - 2.18; P < 0.0001), and x-ray (RR = 1.10; 95% CI: 1.05 - 1.15; P < 0.0001). Despite rates of MRI in SCS patients being half that in the non-SCS group, these patients underwent 19% more imaging procedures overall (P < 0.0001). SCS patients had increased rates of x-ray (RR = 1.27; 95% CI: 1.25 - 1.29), CT scans (RR = 1.32; 95% CI: 1.30 - 1.35), and ultrasound (RR = 1.10; 95% CI: 1.07 - 1.13) (all P < 0.0001). LIMITATIONS: This study is limited by a lack of clinical and historical variables including the complexity of prior surgeries and pain symptomatology. Miscoding cannot be precluded, as this sample is taken from a large nationwide database. CONCLUSIONS: We found a significant trend for increased use of advanced imaging modalities between the years 2000 and 2012 in FBSS patients. Those patients treated with SCS were 50% less likely to receive an MRI (as expected, given prior incompatibility of neuromodulation devices), yet 32% and 27% more likely to receive CT and x-ray, respectively. Despite the decrease in the use of MRI in those patients treated with SCS, their overall imaging rate increased by 19% compared to patients without SCS. This underscores the utility of MR-conditional SCS systems. These findings demonstrate that imaging plays a significant role in driving health care expenditures. This is the largest analysis examining the role of imaging in the FBSS population and the impact of SCS procedures. Further studies are needed to assess the impact of MRI-conditional SCS systems on future trends in imaging in FBSS patients receiving neuromodulation therapies. Key words: Failed back surgery syndrome, spinal cord stimulation, imaging, health care utilization, MRI, chronic pain, back pain, neuromodulation.

Clinical Evidence for Spinal Cord Stimulation for Failed Back Surgery Syndrome (FBSS): Systematic Review.

STUDY DESIGN: A systematic review. OBJECTIVE: A systematic literature review of the clinical data from prospective studies was undertaken to assess the efficacy of spinal cord stimulation (SCS) in the treatment of failed back surgery syndrome (FBSS) in adults. SUMMARY OF BACKGROUND DATA: For patients with unrelenting back pain due to mechanical instability of the spine, degenerative disc disease, spinal injury, or deformity, spinal surgery is a well-accepted treatment option; however, even after surgical intervention, many patients continue to experience chronic back pain that can be notoriously difficult to treat. Clinical evidence suggests that for patients with FBSS, repeated surgery will not likely offer relief. Additionally, evidence suggests long-term use of opioid pain medications is not effective in this population, likely presents additional complications, and requires strict management. METHODS: A systematic literature review was performed using several bibliographic databases, prospective studies in adults using SCS for FBSS were included. RESULTS AND CONCLUSION: SCS has been shown to be a safe and efficacious treatment for this patient population. Recent technological developments in SCS offer even greater pain relief to patients' refractory to other treatment options, allowing patients to regain functionality and improve their quality of life with significant reductions in pain. LEVEL OF EVIDENCE: N/A.

Twiddler's Syndrome and Neuromodulation-Devices: A Troubled Marriage.

OBJECTIVE: The occurrence of Twiddler's syndrome in subjects with neurostimulator devices is poorly understood and might be influenced by age, sex, BMI, use of medication or psychologic disorders. METHODS: Two hundred thiry-five patients who received a neuromodulator were included in this retrospective study in a period between 2008 and 2015. The subjects were divided into a group of Twiddler's syndrome patients (TS) and a group of non-Twiddler's patients (NTS). Outcome measures were gender, age at implantation, type of neuromodulation, use of antipsychotics, antidepressants and opioids, the presence of other psychologic disorders and BMI. RESULTS: Both groups differ significantly in age (p = 0.024), weight (p = 0.001) and BMI (p = 0.001). No statistical difference was found in the type of neuromodulation (p = 0.537), gender (p = 0.368), the use of antipsychotics (p = 0.071), antidepressants (p = 0.097), and opioids (p = 1). Forward stepwise logistic regression of all variables showed that age of implementation (p = 0.029), the use of antipsychotics (p = 0.022) and BMI (p = 0.001) were statistically significant for predicting Twiddler's syndrome. CONCLUSION: Twiddler's syndrome is an uncommon complication of neuromodulation implantable devices. Younger age, use of antipsychotics, and high BMI are risk factors that can be used to facilitate rapid diagnosis and treatment.

Comparison of Clinical Efficacy and Computed Tomographic Analysis of Lead Position Between Three-Column and Five-Column Paddle Leads Spinal Cord Stimulation for Failed Back Surgery Syndrome.

OBJECTIVE: To investigate the difference in clinical outcome and the position of paddle lead spinal cord stimulation (SCS) between 3-column and 5-column paddle lead SCS in patients with failed back surgery syndrome. METHODS: In 21 patients who underwent paddle lead SCS at T9 (3-column, n = 9; 5-column, n =12) for failed back surgery syndrome, a 12-month follow-up numerical rating scale, percent pain relief, and computed tomography assessment of contact angle and percent reduction of T9 canal area were investigated. RESULTS: There was no difference in paresthesia coverage of the painful area, trial success rate, clinical outcomes, and percent pain relief between the 2 groups (P >0.05). The contact angle in the 5-column group was generally more than that of the 3-column group (P = 0.067). Overall reduction of 35.51% ± 4.76% in the T9 canal was observed and there was no difference between the 2 groups (P >0.05) and no correlation between the contact angle and percent T9 spinal canal reduction (r = -0.247, P > 0.05). CONCLUSIONS: Although clinical efficacy of SCS using three-column and five-column paddle lead was not significant different from each other, significant inclination of paddle lead in posterior epidural space with significant reduction in T9 canal area were observed in both groups. The degree of inclination in the 5-column group was more than that in the 3-column lead group. Close approximation of paddle lead contacts to dorsal spinal cord with reduced dorsal cerebrospinal fluid space and intraoperative neurophysiologic guidance might have contributed to the high rate of trial success and long-term pain control.

[Postoperative spinal column]. / Postoperative Wirbelsäule.

STANDARD PROCEDURE: As a rule, postoperative imaging is carried out after spinal interventions to document the exact position of the implant material. INFORMATION: Imaging is absolutely necessary when new clinical symptoms occur postoperatively. In this case a rebleeding or an incorrect implant position abutting a root or the spinal cord must be proven. In addition to these immediately occurring postoperative clinical symptoms, there are a number of complications that can occur several days, weeks or even months later. These include the failed back surgery syndrome, implant loosening or breakage of the material and relapse of a disc herniation and spondylodiscitis. REVIEW: In addition to knowledge of the original clinical symptoms, it is also important to know the operation details, such as the access route and the material used. RECOMMENDATION: In almost all postoperative cases, imaging with contrast medium administration and corresponding correction of artefacts by the implant material, such as the dual energy technique, correction algorithms and the use of special magnetic resonance (MR) sequences are necessary. RECOMMENDATION: In order to correctly assess the postoperative imaging, knowledge of the surgical procedure and the previous clinical symptoms are mandatory besides special computed tomography (CT) techniques and MR sequences.

Thoracic Nerve Root Entrapment by Intrathecal Catheter Coiling: Case Report and Review of the Literature.

BACKGROUND: Intrathecal catheter placement has long-term therapeutic benefits in the management of chronic, intractable pain. Despite the diverse clinical applicability and rising prevalence of implantable drug delivery systems in pain medicine, the spectrum of complications associated with intrathecal catheterization remains largely understudied and underreported in the literature. OBJECTIVE: To report a case of thoracic nerve root entrapment resulting from intrathecal catheter migration. STUDY DESIGN: Case report. SETTING: Inpatient hospital service. RESULTS/ CASE REPORT: A 60-year-old man status post implanted intrathecal (IT) catheter for intractable low back pain secondary to failed back surgery syndrome returned to the operating room for removal of IT pump trial catheter after experiencing relapse of preoperative pain and pump occlusion. Initial attempt at ambulatory removal of the catheter was aborted after the patient reported acute onset of lower extremity radiculopathic pain during the extraction. Noncontrast computed tomography (CT) subsequently revealed that the catheter had ascended and coiled around the T10 nerve root. The patient was taken back to the operating room for removal of the catheter under fluoroscopic guidance, with possible laminectomy for direct visualization. Removal was ultimately achieved with slow continuous tension, with complete resolution of the patient's new radicular symptoms. LIMITATIONS: This report describes a single case report. CONCLUSION: This case demonstrates that any existing loops in the intrathecal catheter during initial implantation should be immediately re-addressed, as they can precipitate nerve root entrapment and irritation. Reduction of the loop or extrication of the catheter should be attempted under continuous fluoroscopic guidance to prevent further neurosurgical morbidity.