Persistent Spinal Pain Syndrome: A Proposal for Failed Back Surgery Syndrome and ICD-11

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.

Direct Peripheral Nerve Stimulation for the Treatment of Complex Regional Pain Syndrome: A 30-Year Review

INTRODUCTION

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy (RSD), is a difficult to treat condition characterized by debilitating pain and limitations in functional ability. Neuromodulation, in the form of spinal cord stimulation (SCS) and peripheral nerve stimulation (PNS), have been traditionally used as a treatment for CRPS with variable success.

OBJECTIVE

This chart review describes the use of implantable PNS systems in the treatment of CRPS of the upper and lower extremities spanning nearly three decades.

MATERIALS AND METHODS

A retrospective chart review was performed on 240 patients with PNS implanted between 1990 and 2017 at our institution. Of these, 165 patients were identified who had PNS systems implanted for a diagnosis of CRPS. Patient profile, including baseline characteristics, comorbidities, past/current interventions/medications and targeted nerves, was descriptively summarized through standard summary statistics. Patients' pain scores and opioid consumptions at baseline (preimplant), 1 month, 6 months, and 12 months were collected and compared. Device revisions and explants were summarized, and patient functional outcomes were described.

RESULTS

Pain scores at baseline and at 12-month follow-up were decreased from a mean of 7.4 ± 1.6 to 5.5 ± 2.4 and estimated to be 1.87 (95% CI: [1.29, 2.46], paired t-test p-value <0.001) lower at 12 months. At baseline, 62% of patients were on chronic opioid therapy, compared with 41% at 12 months. Of 126 patients who reported changes in functional status, 64 (51%) reported improvement, 27 (21%) reported worsening, and 35 (28%) did not report any meaningful change. Excluding end-of-life battery replacements, surgical revision occurred in 56 (34%) of patients. Thirteen patients (8%) underwent implantation of a second PNS because of symptomatic expansion outside of the original painful region. Device explant was performed in 32 (19%) of patients. Median length of follow-up was 74 [14, 147] months. Of the 36 patients who continue to follow-up at our institution, 29 (81%) continue to use their PNS.

CONCLUSIONS

We can conclude that PNS is a useful modality to improve function and reduce long-term pain in selected patients suffering from CRPS type I and type II.

The appropriate use of neurostimulation of the spinal cord and peripheral nervous system for the treatment of chronic pain and ischemic diseases: the Neuromodulation Appropriateness Consensus Committee

INTRODUCTION

The Neuromodulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society (INS) evaluated evidence regarding the safety and efficacy of neurostimulation to treat chronic pain, chronic critical limb ischemia, and refractory angina and recommended appropriate clinical applications.

METHODS

The NACC used literature reviews, expert opinion, clinical experience, and individual research. Authors consulted the Practice Parameters for the Use of Spinal Cord Stimulation in the Treatment of Neuropathic Pain (2006), systematic reviews (1984 to 2013), and prospective and randomized controlled trials (2005 to 2013) identified through PubMed, EMBASE, and Google Scholar.

RESULTS

Neurostimulation is relatively safe because of its minimally invasive and reversible characteristics. Comparison with medical management is difficult, as patients considered for neurostimulation have failed conservative management. Unlike alternative therapies, neurostimulation is not associated with medication-related side effects and has enduring effect. Device-related complications are not uncommon; however, the incidence is becoming less frequent as technology progresses and surgical skills improve. Randomized controlled studies support the efficacy of spinal cord stimulation in treating failed back surgery syndrome and complex regional pain syndrome. Similar studies of neurostimulation for peripheral neuropathic pain, postamputation pain, postherpetic neuralgia, and other causes of nerve injury are needed. International guidelines recommend spinal cord stimulation to treat refractory angina; other indications, such as congestive heart failure, are being investigated.

CONCLUSIONS

Appropriate neurostimulation is safe and effective in some chronic pain conditions. Technological refinements and clinical evidence will continue to expand its use. The NACC seeks to facilitate the efficacy and safety of neurostimulation.

Polyanalgesic Consensus Conference--2012: recommendations to reduce morbidity and mortality in intrathecal drug delivery in the treatment of chronic pain

INTRODUCTION

Targeted intrathecal drug infusion to treat moderate to severe chronic pain has become a standard part of treatment algorithms when more conservative options fail. This therapy is well established in the literature, has shown efficacy, and is an important tool for the treatment of both cancer and noncancer pain; however, it has become clear in recent years that intrathecal drug delivery is associated with risks for serious morbidity and mortality.

METHODS

The Polyanalgesic Consensus Conference is a meeting of experienced implanting physicians who strive to improve care in those receiving implantable devices. Employing data generated through an extensive literature search combined with clinical experience, this work group formulated recommendations regarding awareness, education, and mitigation of the morbidity and mortality associated with intrathecal therapy to establish best practices for targeted intrathecal drug delivery systems.

RESULTS

Best practices for improved patient care and outcomes with targeted intrathecal infusion are recommended to minimize the risk of morbidity and mortality. Areas of focus include respiratory depression, infection, granuloma, device-related complications, endocrinopathies, and human error. Specific guidance is given with each of these issues and the general use of the therapy.

CONCLUSIONS

Targeted intrathecal drug delivery systems are associated with risks for morbidity and mortality that can be devastating. The panel has given guidance to treating physicians and healthcare providers to reduce the incidence of these problems and to improve outcomes when problems occur.

Polyanalgesic Consensus Conference 2012: recommendations for the management of pain by intrathecal (intraspinal) drug delivery: report of an interdisciplinary expert panel

INTRODUCTION

The use of intrathecal (IT) infusion of analgesic medications to treat patients with chronic refractory pain has increased since its inception in the 1980s, and the need for clinical research in IT therapy is ongoing. The Polyanalgesic Consensus Conference (PACC) panel of experts convened in 2000, 2003, and 2007 to make recommendations on the rational use of IT analgesics based on preclinical and clinical literature and clinical experiences.

METHODS

The PACC panel convened again in 2011 to update the standard of care for IT therapies to reflect current knowledge gleaned from literature and clinical experience. A thorough literature search was performed, and information from this search was provided to panel members. Analysis of published literature was coupled with the clinical experience of panel members to form recommendations regarding the use of IT analgesics to treat chronic pain.

RESULTS

After a review of literature published from 2007 to 2011 and discussions of clinical experience, the panel created updated algorithms for the rational use of IT medications for the treatment of neuropathic pain and nociceptive pain.

CONCLUSIONS

The advent of new algorithmic tracks for neuropathic and nociceptive pain is an important step in improving patient care. The panel encourages continued research and development, including the development of new drugs, devices, and safety recommendations to improve the care of patients with chronic pain.

Polyanalgesic Consensus Conference--2012: recommendations on trialing for intrathecal (intraspinal) drug delivery: report of an interdisciplinary expert panel

INTRODUCTION

Trialing for intrathecal pump placement is an essential part of the decision-making process in placing a permanent device. In both the United States and the international community, the proper method for trialing is ill defined.

METHODS

The Polyanalgesic Consensus Conference (PACC) is a group of well-published experienced practitioners who meet to update the state of care for intrathecal therapies on the basis of current knowledge in the literature and clinical experience. Anexhaustive search is performed to create a base of information that the panel considers when making recommendations for best clinical practices. This literature, coupled with clinical experience, is the basis for recommendations and for identification of gaps in the base of knowledge regarding trialing for intrathecal pump placement.

RESULTS

The panel has made recommendations for the proper methods of trialing for long-term intrathecal drug delivery.

CONCLUSION

The use of intrathecal drug delivery is an important part of the treatment algorithm for moderate to severe chronic pain. It has become common practice to perform a temporary neuroaxial infusion before permanent device implantation. On the basis of current knowledge, the PACC has developed recommendations to improve care. The need to update these recommendations will be very important as new literature is published.

Administering ziconotide and monitoring patients treated with ziconotide: expert opinions

Some patients with chronic pain who are intolerant of or refractory to treatment with systemic analgesics may benefit from intrathecal therapy. Ziconotide is the first nonopioid analgesic approved by the United States Food and Drug Administration for intrathecal administration. Several randomized, double-blind, placebo-controlled clinical trials have demonstrated the efficacy and safety of ziconotide. However, the maximum recommended dosing and titration schedule provided in the prescribing information may be too aggressive for some patients, and experience has demonstrated that ziconotide is better tolerated with slower titration to a lower maximum dose. Efficacy can be assessed by an evaluation of changes in pain, functionality, and quality of life. Cognitive adverse events may be subtle; therefore, it is important that health care professionals not only monitor patients for signs and symptoms of cognitive adverse events, but also teach family members how to do the same. Careful patient assessment and monitoring can help optimize the potential benefit from treatment with ziconotide.

The future of peripheral nerve stimulation

The field of peripheral nerve stimulation (PNS) is now experiencing a phase of rapid growth in number of patients, number of implanters, number of indications, and procedure types. This, however, appears to be only a beginning of major developments that could revolutionize the field of PNS. It is expected that the progress in PNS will continue simultaneously in several directions as new indications, new stimulation targets and new device designs evolve in the foreseeable future. Responding to a major need for safe and effective pain treatments and following a general trend toward less-invasive and nondestructive interventions, PNS has the potential of becoming a premier pain-relieving modality that will be used instead of or in combination with existing more established approaches such as spinal cord stimulation and pharmacological pain control. Recent technological advancements are cause for considerable optimism regarding the development of PNS and are likely to be a beginning of a major overhaul in our perception of PNS approaches. Expanding the number of applications will without question strengthen the field of PNS. The turning point, however, will not occur until sufficient scientific evidence is gathered to unequivocally prove its safety, clinical efficacy and cost-effectiveness, and when PNS applications become officially endorsed through regulatory approval of each indication. Such changes will allow implanters to use approved devices for approved indications--instead of the contemporary 'off-label' use--and at the same time give device manufacturers a chance to market these devices and support education on their appropriate use.

Evidence-based interventional pain medicine according to clinical diagnoses. 16. Complex regional pain syndrome

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy is a pain syndrome with an unclear pathophysiology and unpredictable clinical course. The disease is often therapy resistant, the natural course not always favorable. The diagnosis of CRPS is based on signs and symptoms derived from medical history and physical examination. Pharmacological pain management and physical rehabilitation of limb function are the main pillars of therapy and should be started as early as possible. If, however, there is no improvement of limb function and persistent severe pain, interventional pain management techniques may be considered. Intravenous regional blocks with guanethidine did not prove superior to placebo but frequent side effects occurred.Therefore this technique receives a negative recommendation (2 A-). Sympathetic block is the interventional treatment of first choice and has a 2 B+ rating. Ganglion stellatum (stellate ganglion) block with repeated local anesthetic injections or by radiofrequency denervation after positive diagnostic block is documented in prospective and retrospective trials in patients suffering from upper limb CRPS. Lumbar sympathetic blocks can be performed with repeated local anesthetic injections. For a more prolonged lumbar sympathetic block radiofrequency treatment is preferred over phenol neurolysis because effects are comparable whereas the risk for side effects is lower (2 B+). For patients suffering from CRPS refractory to conventional treatment and sympathetic blocks, plexus brachialis block or continuous epidural infusion analgesia coupled with exercise therapy may be tried (2 C+). Spinal cord stimulation is recommended if other treatments fail to improve pain and dysfunction (2 B+). Alternatively peripheral nerve stimulation can be considered, preferentially in study conditions (2 C+).

Proposed new diagnostic criteria for complex regional pain syndrome

This topical update reports recent progress in the international effort to develop a more accurate and valid diagnostic criteria for complex regional pain syndrome (CRPS). The diagnostic entity of CRPS (published in the International Association for the Study of Pain's Taxonomy monograph in 1994; International Association for the Study of Pain [IASP]) was intended to be descriptive, general, and not imply etiopathology, and had the potential to lead to improved clinical communication and greater generalizability across research samples. Unfortunately, realization of this potential has been limited by the fact that these criteria were based solely on consensus and utilization of the criteria in the literature has been sporadic at best. As a consequence, the full potential benefits of the IASP criteria have not been realized. Consensus-derived criteria that are not subsequently validated may lead to over- or underdiagnosis, and will reduce the ability to provide timely and optimal treatment. Results of validation studies to date suggest that the IASP/CRPS diagnostic criteria are adequately sensitive; however, both internal and external validation research suggests that utilization of these criteria causes problems of overdiagnosis due to poor specificity. This update summarizes the latest international consensus group's action in Budapest, Hungary to approve and codify empirically validated, statistically derived revisions of the IASP criteria for CRPS.

Failure modes of spinal cord stimulation hardware

Object

Epidural spinal cord stimulation (SCS) is effective at treating refractory pain. The failure modes of the implanted hardware, however, have not been well studied. A better understanding of this could aid in improving the current procedure or designing future devices.

Methods

The authors reviewed electronic charts and operative reports of 289 patients who had undergone SCS implantation between 1998 and 2002 at the Cleveland Clinic Foundation. Data were collected on demographics, type of hardware, date of implantation procedure, indication for treatment, time to failure, and failure mode. Data were then analyzed to identify significant differences.

A total of 577 procedures were performed, 43.5% of which involved revision or removal of SCS hardware. The most common indication was complex regional pain syndrome 1, and this was followed by failed–back surgery syndrome. The median number of procedures per patient was two. Approximately 80% of all leads were the percutaneous type. The majority (62%) of leads were placed in the thoracic region, and 33.5% of all leads required revision. Poor pain relief coverage was the most common indication for revision. Surgically implanted leads broke twice as often as percutaneous leads. In 46% of the patients, hardware revision was required, and multiple revisions were necessary in 22.5%. Three-way ANOVA revealed significant differences in failure mode rates according to location (cervical compared with thoracic, p = 0.037) and failure modes (p = 0.019). Laminotomy leads tended to break and migrate sooner than percutaneous leads. Thoracic leads became infected sooner than cervical leads.

Conclusions

The results of this analysis of SCS hardware failures may be used as a basis for refining surgical technique and designing the next generation of SCS hardware.

Complex regional pain syndrome: manifestations and the role of neurostimulation in its management

The hallmark of complex regional pain syndrome (CRPS) is excruciating pain (aching, burning, pricking, or shooting). Diagnosis should be established as soon as possible, as response to treatment is adversely affected by any delay. Treatment of CRPS is aimed at improving function, using an interdisciplinary, time-dependent, patient-dependent approach that encompasses rehabilitation, psychological therapy, and pain management. If no response to conventional treatment (e.g., pharmacotherapy) is noted within 12-16 weeks, a more interventional technique such as spinal cord stimulation (SCS) should be used. SCS has been shown to be highly effective in the treatment of CRPS type I, resulting in a significant, long-term reduction in pain and improvement in quality of life. SCS is particularly effective at helping to restore function in affected extremities, especially if applied early in the course of the disease. SCS is also cost effective and improves health-related quality of life.

Tunneled Epidural Catheter Infections in Noncancer Pain: Increased Risk in Patients With Neuropathic Pain/Complex Regional Pain Syndrome

BACKGROUND AND OBJECTIVE

Tunneled epidural catheters are often used to control pain and facilitate rehabilitation in patients with regional pain syndromes. A cohort retrospective study design was undertaken to evaluate the risk of catheter-related infection in patients who underwent a TEC placement to manage their chronic noncancer regional pain over a 5-year period.

METHODS

There were 260 tunneled epidural catheters placed in 218 patients accounting for a total of 10,985 catheter-days. Of these, 230 catheters were placed in patients with neuropathic pain (90% of whom had complex regional pain syndrome) and 30 catheters in patients with somatic pain.

RESULTS

There were 24 epidural space infections in symptomatic patients, 23 of whom were in the neuropathic pain group-22 had complex regional pain syndrome. Additionally, tunneled epidural catheters had to be discontinued in 34 patients because of superficial infection or suspicion of infection; 33 of these were in the neuropathic pain group. The differences in the infection rates were significantly higher in the neuropathic pain group compared to the somatic group. When analyzed to an infection index per 1,000 catheter-days, the rate of infection rate was 5.51 for the patients with neuropathic pain and 2.43 for the patients with somatic pain. The rates for deep and superficial infections were 2.26 and 3.25, respectively, per 1000 catheter-days for the neuropathic pain group compared to 1.22 for both deep and superficial infections in the patients with somatic pain. There were 6 frank epidural abscesses upon contrast-enhanced magnetic resonance imaging examinations of the spine, 1 epidural phlegmon and 2 patients displayed mild or questionable epidural enhancement on magnetic resonance imaging, suggestive of epidural inflammation. All these magnetic resonance imaging abnormalities were detected in patients with complex regional pain syndrome. Two of the patients with epidural abscesses underwent surgical exploration and drainage of the epidural abscess, though no neurologic deficits were observed in any of the patients.

CONCLUSIONS

The higher risk of tunneled epidural catheter infection observed in patients with neuropathic pain (particularly complex regional pain syndrome) warrants further study.

Occipital nerve electrical stimulation via the midline approach and subcutaneous surgical leads for treatment of severe occipital neuralgia: a pilot study

Persistent occipital neuralgia can produce severe headaches that may not be controllable by conservative or surgical approaches. We describe a case series of 6 patients who had chronic headaches over an average of 4.9 yr who underwent occipital nerve electrical stimulation lead implantation using a modified midline approach. The patients had received conservative and surgical therapies in the past including oral antidepressants, membrane stabilizers, opioids, occipital nerve blocks, and radiofrequency ablations. Significant decreases in pain visual analog scale (VAS) scores and drastic improvement in functional capacity were observed during the occipital stimulation trial and during the 3-mo follow-up after implantation. The mean VAS score changed from 8.66 +/- 1.0 to 2.5 +/- 1.3 whereas pain disability index improved from 49.8 +/- 15.9 to 14.0 +/- 7.4. Our midline approach has several advantages compared with the submastoid approach used elsewhere. There is only one small midline incision over the upper neck and the strain on the lead extension occurs only with flexion and is minimal with lateral flexion and rotation, which contributes to overall stability of this system.

American Academy of Disability Evaluating Physicians (AADEP) position paper: complex regional pain syndrome I (RSD): impairment and disability issues

OBJECTIVE

To provide an overview and methodology for the evaluation of impairment and functional residual capacity in complex regional pain syndrome I (CRPS I, RSD). This paper is intended to provide assistance to physicians asked to evaluate impairment- and disability-related issues and is not primarily geared to guide treatment of the CRPS I patient.

METHOD

Conference and literature review by neurology, anesthesiology, pain medicine, physiatry, and disability evaluating physicians followed by description of issues, options, and recommendations based upon the committee's deliberations and the widely used AMA Guides to the Evaluation of Permanent Impairment, fourth and fifth editions. The authors present functional criteria for assessing the severity of CRPS. These criteria were developed by committee consensus opinion based on multidisciplinary clinical experience considering daily functional issues. They can be used in conjunction with CRPS-ADL Classes of Impairment in order to categorize an individual into a specific class for purposes of permanent impairment rating. Future reliability and validity studies of this rating scale are pending future use, acceptance and, hopefully, additional studies.

RESULTS

Evaluators should perform a comprehensive assessment of patients with CRPS I to make an accurate diagnosis and exclude other conditions that could explain the symptoms and signs of the condition. While radiological, laboratory, and other diagnostic studies may be of assistance in making the diagnosis, in the final analysis, this is a clinical diagnosis. Impairment is based on objectively validated limitation in activities of daily living (ADL).

Cost benefit analysis of neurostimulation for chronic pain

OBJECTIVES

To assess the healthcare utilization of patients with intractable chronic neuropathic pain treated with spinal cord stimulation and peripheral nerve stimulation and to provide a cost-benefit analysis.

METHODS

The case records of 222 consecutive patients who received spinal cord stimulation or peripheral nerve stimulation implants at the Cleveland Clinic Foundation between 1990 and 1998 were reviewed retrospectively. Patients were asked to complete a Neurostimulation Outcome Questionnaire designed to gather data on utilization of healthcare resources starting 1 year before surgical implantation. These data were pooled and net differences in events per patient per year, before and after device implantation were calculated and modeled to 2000 cost data obtained from the Medicare Fee Schedule and Healthcare Financing Administration.

RESULTS

Neurostimulation Outcome Questionnaires were returned by 128 patients. The mean patient age was 46 +/- 12.5 years (range 21-71 years) and the mean implant duration was 3.1 +/- 2.3 years (range 0.5-8.9 years). The mean per patient total reimbursement of spinal cord stimulation/peripheral nerve stimulation absent pharmacotherapy was $38,187. Patients treated with spinal cord stimulation/peripheral nerve stimulation for pain management achieved reductions in physician office visits, nerve blocks, radiologic imaging, emergency department visits, hospitalizations, and surgical procedures, which translated into a net annual savings of approximately $30,221 and a savings of $93,685 over the 3.1-year implant duration. The large reduction in healthcare utilization following spinal cord stimulation/peripheral nerve stimulation implantation resulted in a net per patient per year cost savings of approximately $17,903.

DISCUSSION

The reduced demand for healthcare resources by patients receiving neurostimulation suggests that peripheral nerve stimulation and spinal cord stimulation treatment, although associated with relatively high initial costs, demonstrates substantial long-term economic benefits. Thus, neurostimulation should be considered as a viable option for the early treatment of patients with intractable chronic neuropathic pain.

Relaxation and music reduce pain following intestinal surgery

Three nonpharmacological nursing interventions, relaxation, chosen music, and their combination, were tested for pain relief following intestinal (INT) surgery in a randomized clinical trial. The 167 patients were randomly assigned to one of three intervention groups or control and were tested during ambulation and rest on postoperative days 1 and 2. Pain sensation and distress were measured with visual analog scales (VAS). Multivariate analysis of covariance showed significantly less post-test pain in the intervention groups than in the control group on both days after rest and at three of six ambulation post-tests (p = .024-.001), resulting in 16-40% less pain. Mixed effects after ambulation were due to the large variation in pain and difficulty relaxing while returning to bed; but post hoc explorations showed effects for those with high and low pain. These interventions are recommended along with analgesics for greater postoperative relief without additional side effects.

Interventional modalities in the treatment of complex regional pain syndrome

Complex regional pain syndrome (CRPS) applies to a variety of conditions in which symptoms such as allodynia and hyperalgesia predominate along with hyperpathia and vasomotor/sudomotor disturbances. The incidence of CRPS in the chronic pain population varies and is difficult to determine, though it appears to affect women more than men. Treatment is multidisciplinary, and recovery of function and the reduction of pain are the main goals of treatment;this article addresses some of the interventional modalities that are used.