Neuromodulation Strategies to Reduce Inflammation and Improve Lung Complications in COVID-19 Patients.

Since the outbreak of the COVID-19 pandemic, races across academia and industry have been initiated to identify and develop disease modifying or preventative therapeutic strategies has been initiated. The primary focus has been on pharmacological treatment of the immune and respiratory system and the development of a vaccine. The hyperinflammatory state ("cytokine storm") observed in many cases of COVID-19 indicates a prognostically negative disease progression that may lead to respiratory distress, multiple organ failure, shock, and death. Many critically ill patients continue to be at risk for significant, long-lasting morbidity or mortality. The human immune and respiratory systems are heavily regulated by the central nervous system, and intervention in the signaling of these neural pathways may permit targeted therapeutic control of excessive inflammation and pulmonary bronchoconstriction. Several technologies, both invasive and non-invasive, are available and approved for clinical use, but have not been extensively studied in treatment of the cytokine storm in COVID-19 patients. This manuscript provides an overview of the role of the nervous system in inflammation and respiration, the current understanding of neuromodulatory techniques from preclinical and clinical studies and provides a rationale for testing non-invasive neuromodulation to modulate acute systemic inflammation and respiratory dysfunction caused by SARS-CoV-2 and potentially other pathogens. The authors of this manuscript have co-founded the International Consortium on Neuromodulation for COVID-19 to advocate for and support studies of these technologies in the current coronavirus pandemic.

A proposed definition of remission from chronic pain, based on retrospective evaluation of 24-month outcomes with spinal cord stimulation.

Objective: In the treatment of chronic diseases, remission is commonly used as a meaningful treatment goal, synonymous with the absence of significant clinical signs and symptoms of a disease, but not representing a cure. The objective of this paper is to propose a definition for remission for use as an outcome to evaluate the long-term efficacy of therapies for chronic pain. Methods: Data from a randomized clinical trial (NCT01609972) testing the efficacy of spinal cord stimulation in low back and leg pain subjects was used to evaluate the association between pain and functional outcomes and identify the cut-off value to predict remission. Available data over 24-month assessment period included visual analog score (VAS), disability (Oswestry Disability Index [ODI]), patient and clinician global impression of change (PGIC and CGIC), and patient satisfaction. Cluster analysis, Pearson's correlation coefficients, sensitivity, and specificity analyses were used to evaluate its utility in predicting higher patient functionality and satisfaction. Results: Though the term remission has been used in the chronic pain field, a consistent definition has not been previously established. Based on the analysis of the clinical data, we propose that a sustained (≥6 months) pain score of ≤3.0 cm out of 10 cm on VAS be defined as remission. Applying this definition to the clinical trial data: subjects in remission at 24 months versus non-remitters were significantly more likely to be in the highest functional category of minimally disabled according to the ODI (31.5 vs. 8.2%, respectively, p = 0.001), and be 'very satisfied' (75.7 vs 22.6%, respectively, p < 0.001). Conclusions: The validity of the proposed definition of remission is supported by the persistence of remission in this study group, and its correspondence with patient satisfaction, and reduced disability. Further evaluation of the definition using clinical data from other long-term studies is needed.

The Polyanalgesic Consensus Conference (PACC): Recommendations on Intrathecal Drug Infusion Systems Best Practices and Guidelines.

INTRODUCTION: Pain treatment is best performed when a patient-centric, safety-based philosophy is used to determine an algorithmic process to guide care. Since 2007, the International Neuromodulation Society has organized a group of experts to evaluate evidence and create a Polyanalgesic Consensus Conference (PACC) to guide practice. METHODS: The current PACC update was designed to address the deficiencies and innovations emerging since the previous PACC publication of 2012. An extensive literature search identified publications between January 15, 2007 and November 22, 2015 and authors contributed additional relevant sources. After reviewing the literature, the panel convened to determine evidence levels and degrees of recommendations for intrathecal therapy. This meeting served as the basis for consensus development, which was ranked as strong, moderate or weak. Algorithms were developed for intrathecal medication choices to treat nociceptive and neuropathic pain for patients with cancer, terminal illness, and noncancer pain, with either localized or diffuse pain. RESULTS: The PACC has developed an algorithmic process for several aspects of intrathecal drug delivery to promote safe and efficacious evidence-based care. Consensus opinion, based on expertise, was used to fill gaps in evidence. Thirty-one consensus points emerged from the panel considerations. CONCLUSION: New algorithms and guidance have been established to improve care with the use of intrathecal drug delivery.

The Polyanalgesic Consensus Conference (PACC): Recommendations for Trialing of Intrathecal Drug Delivery Infusion Therapy.

INTRODUCTION: Intrathecal (IT) drug infusion is an appropriate and necessary tool in the algorithm to treat refractory cancer and noncancer pain. The decision-making steps/methodology for selecting appropriate patients for implanted targeted drug delivery systems is controversial and complicated. Therefore, a consensus on best practices for determining appropriate use of IT drug infusion may involve testing/trialing this therapy before implantation. METHODS: This current Polyanalgesic Consensus Conference (PACC) update was designed to address the deficiencies and emerging innovations since the previous PACC convened in 2012. A literature search identified publications available since the previous PACC publications in 2014, and relevant sources were contributed by the PACC members. After reviewing the literature, the panel determined the evidence levels and degrees of recommendations. The developed consensus was ranked as strong (>80%), moderate (50-79%), or weak (<49%). RESULTS: The trialing for IT drug delivery systems (IDDS) remains an area of continued controversy. The PACC recommendations for trialing are presented in 34 consensus points and cover trialing for morphine, ziconotide, and medication admixtures; starting doses and titration practices; measurements of success; trial settings and monitoring; management of systemic opioids during trialing; and the role of psychological evaluation. Finally, the PACC describes clinical scenarios in which IT trialing is required or not required. CONCLUSION: The PACC provides consensus guidance on best practices of trialing for IDDS implants. In addition, the PACC recommends that no trial may be required in certain patient populations.

The Neurostimulation Appropriateness Consensus Committee (NACC) Recommendations for Infection Prevention and Management.

INTRODUCTION: The use of neurostimulation for pain has been an established therapy for many decades and is a major tool in the arsenal to treat neuropathic pain syndromes. Level I evidence has recently been presented to substantiate the therapy, but this is balanced against the risk of complications of an interventional technique. METHODS: The Neurostimulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society convened an international panel of well published and diverse physicians to examine the best practices for infection mitigation and management in patients undergoing neurostimulation. The NACC recommendations are based on evidence scoring and peer-reviewed literature. Where evidence is lacking the panel added expert opinion to establish recommendations. RESULTS: The NACC has made recommendations to improve care by reducing infection and managing this complication when it occurs. These evidence-based recommendations should be considered best practices in the clinical implantation of neurostimulation devices. CONCLUSION: Adhering to established standards can improve patient care and reduce the morbidity and mortality of infectious complications in patients receiving neurostimulation.

The dorsal root ganglion in chronic pain and as a target for neuromodulation: a review.

BACKGROUND: In the not-too-distant past, the dorsal root ganglion (DRG) was portrayed as a passive neural structure without involvement in the development or maintenance of chronic neuropathic pain (NP). The DRG was thought of as a structure that merely "supported" physiologic communication between the peripheral nervous system (PNS) and the central nervous system (CNS). Newer scientific information regarding the anatomic and physiologic changes that occur within the DRG as a result of environmental pressures has dispelled this concept and suggests that the DRG is an active participant in the development of NP. This new information, along with new clinical data showing that stimulation of the DRG reduces intensity of pain, suggests that the DRG can be a robust target for neuromodulation therapies. METHODS: A review of the anatomical and physiological literature regarding the role of the DRG in the development of NP was performed utilizing SciBase, PubMed, and Google Scholar. The information gathered was used to lay an anatomic and physiologic foundation for establishing the DRG as a relevant target for neuromodulation therapies and to formulate a hypothesis as to how electrical stimulation of the DRG might reverse the process and perception of NP. CONCLUSIONS: The DRG is an active participant in the development of NP. DRG stimulation has multiple effects on the abnormal changes that occur within the DRG as a result of peripheral afferent fiber injury. The sum total of these stimulation effects is to stabilize and decrease hyperexcitability of DRG neurons and thereby decrease NP.

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.

The appropriate use of neurostimulation: stimulation of the intracranial and extracranial space and head for chronic pain. Neuromodulation Appropriateness Consensus Committee.

INTRODUCTION: The International Neuromodulation Society (INS) has identified a need for evaluation and analysis of the practice of neurostimulation of the brain and extracranial nerves of the head to treat chronic pain. METHODS: The INS board of directors chose an expert panel, the Neuromodulation Appropriateness Consensus Committee (NACC), to evaluate the peer-reviewed literature, current research, and clinical experience and to give guidance for the appropriate use of these methods. The literature searches involved key word searches in PubMed, EMBASE, and Google Scholar dated 1970-2013, which were graded and evaluated by the authors. RESULTS: The NACC found that evidence supports extracranial stimulation for facial pain, migraine, and scalp pain but is limited for intracranial neuromodulation. High cervical spinal cord stimulation is an evolving option for facial pain. Intracranial neurostimulation may be an excellent option to treat diseases of the nervous system, such as tremor and Parkinson's disease, and in the future, potentially Alzheimer's disease and traumatic brain injury, but current use of intracranial stimulation for pain should be seen as investigational. CONCLUSIONS: The NACC concludes that extracranial nerve stimulation should be considered in the algorithmic treatment of migraine and other disorders of the head. We should strive to perfect targets outside the cranium when treating pain, if at all possible.

The appropriate use of neurostimulation: avoidance and treatment of complications of neurostimulation therapies for the treatment of chronic pain. Neuromodulation Appropriateness Consensus Committee.

INTRODUCTION: The International Neuromodulation Society (INS) has determined that there is a need for guidance regarding safety and risk reduction for implantable neurostimulation devices. The INS convened an international committee of experts in the field to explore the evidence and clinical experience regarding safety, risks, and steps to risk reduction to improve outcomes. METHODS: The Neuromodulation Appropriateness Consensus Committee (NACC) reviewed the world literature in English by searching MEDLINE, PubMed, and Google Scholar to evaluate the evidence for ways to reduce risks of neurostimulation therapies. This evidence, obtained from the relevant literature, and clinical experience obtained from the convened consensus panel were used to make final recommendations on improving safety and reducing risks. RESULTS: The NACC determined that the ability to reduce risk associated with the use of neurostimulation devices is a valuable goal and possible with best practice. The NACC has recommended several practice modifications that will lead to improved care. The NACC also sets out the minimum training standards necessary to become an implanting physician. CONCLUSIONS: The NACC has identified the possibility of improving patient care and safety through practice modification. We recommend that all implanting physicians review this guidance and consider adapting their practice accordingly.

The appropriate use of neurostimulation: new and evolving neurostimulation therapies and applicable treatment for chronic pain and selected disease states. Neuromodulation Appropriateness Consensus Committee.

INTRODUCTION: The International Neuromodulation Society (INS) has determined that there is a need to provide an expert consensus that defines the appropriate use of neuromodulation technologies for appropriate patients. The Neuromodulation Appropriateness Consensus Committee (NACC) was formed to give guidance to current practice and insight into future developments. METHODS: The INS executive board selected members of the international scientific community to analyze scientific evidence for current and future innovations and to use clinical experience to fill in any gaps in information. The NACC used PubMed and Google Scholar to obtain current evidence in the field and used clinical and research experience to give a more complete picture of the innovations in the field. RESULTS: The NACC has determined that currently approved neurostimulation techniques and technologies have expanded our ability to treat patients in a more effective and specific fashion. Despite these advances, the NACC has identified several additional promising technologies and potential applications for neurostimulation that could move this field forward and expand the applicability of neuromodulation. CONCLUSIONS: The NACC concludes that the field of neurostimulation is an evolving and rapidly changing one that will lead to improved patient access, safety, and outcomes.

The role of the dorsal root ganglion in the development of neuropathic pain.

BACKGROUND: The dorsal root ganglion (DRG), in the not too distant past, had been thought of as a passive organ not involved in the development of abnormal aberrent neuropathic pain (NP), but merely metabolically "supporting" physiologic functions between the peripheral nervous system (PNS) and the central nervous system (CNS). New information regarding metabolic change within the DRG has dispelled this supportive passive role and suggests that the DRG is an active, not a passive, organ, in the process of the development of chronic pain. METHODS: A review of the anatomic and physiologic literature utilizing PubMed and Google Scholar was performed to create a review of the anatomic and physiologic foundations for the development of NP after peripheral afferent fiber injury. CONCLUSIONS: The DRG is as involved in the process of generating NP as is the nociceptor and the dorsal horn of the spinal cord.

Spinal cord stimulation as treatment for complex regional pain syndrome should be considered earlier than last resort therapy.

BACKGROUND: Spinal cord stimulation (SCS), by virtue of its historically described up-front costs and level of invasiveness, has been relegated by several complex regional pain syndrome (CRPS) treatment algorithms to a therapy of last resort. Newer information regarding safety, cost, and efficacy leads us to believe that SCS for the treatment of CRPS should be implemented earlier in a treatment algorithm using a more comprehensive approach. METHODS: We reviewed the literature on pain care algorithmic thinking and applied the safety, appropriateness, fiscal or cost neutrality, and efficacy (S.A.F.E.) principles to establish an appropriate position for SCS in an algorithm of pain care. RESULTS AND CONCLUSION: Based on literature-contingent considerations of safety, efficacy, cost efficacy, and cost neutrality, we conclude that SCS should not be considered a therapy of last resort for CRPS but rather should be applied earlier (e.g., three months) as soon as more conservative therapies have failed.

A history of intraspinal analgesia, a small and personal journey.

INTRODUCTION: There is a large and robust literature on the spinal use of opioids and non-opioids alike, but unless one is my age and older, very few persons know how we got here. This small history offering tells us how we got to where we are today regarding the science, clinical uses, and management of intraspinal analgesia. METHODS: I have reviewed the literature bases of Google Scholar and the National Library of Medicine using the key words: history, opium, spinal analgesia, spinal morphine, intrathecal (IT), opioid receptors, endogenous opioids, IT delivery of opioids, and IT side-effects/complications. RESULTS: In this personal review of the history of intraspinal analgesia, I relate my own early and later experiences of the science and clinical uses of intraspinal morphine, other opioids, and non-opioids alike to a historical context. This review outlines a rather small history of opium, the historical use of opium and its various compounds, and the search for and answer to the question, "why was the poppy created for wondrous medicinal uses for mankind?" This search led to the discovery of endogenous opioid like chemicals, the discovery of opiate receptors for these endogenous opioids, the first uses of intraspinal opioids in animal models and man, and, finally, our understanding of the appropriate and inappropriate clinical uses of intraspinal analgesia. Within this paper, I acknowledge the works of my colleagues and the "heroes" who have laid the foundation for our understanding of intraspinal analgesia. CONCLUSIONS: The history of the use of intraspinal analgesia is rich and guides us to advance the science and clinical use of intraspinal analgesia without reinventing the wheel.

Using the SAFE principles when evaluating electrical stimulation therapies for the pain of failed back surgery syndrome.

OBJECTIVE: In this paper we review the literature on failed back surgery syndrome (FBSS) and use principles of Safety, Appropriateness, Fiscal Neutrality, and Effectiveness (SAFE) to determine the appropriate place for spinal cord stimulation (SCS) for the treatment of FBSS. METHODS AND RESULTS: We analyzed the most recent literature regarding treatments of pain due to FBSS and used the SAFE principles to reprioritize pain treatments, particularly electrical stimulation therapies, for FBSS in a more appropriate, relevant, and up to date continuum of care. CONCLUSIONS: Based on this review and analysis of the safety, appropriateness, cost-effectiveness, and efficacy of treatments for the pain of FBSS, relegating SCS to a last resort therapy is no longer justifiable. SCS should be considered before submitting a patient to either long-term systemic opioid therapy or repeat spinal surgery for chronic pain resulting from FBSS.

Practice choices and challenges in the current intrathecal therapy environment: an online survey.

OBJECTIVE: The objective of this study was to evaluate current practice characteristics, treatment choices, clinical experiences, and economic concerns associated with intrathecal therapy. DESIGN: Health care professionals in the United States, who were known to actively use intrathecal therapy in their practices, were recruited to participate in an online survey; contact information was obtained via Internet searches, university Websites, association memberships, industry databases, and personal contacts. Survey responses were summarized descriptively. RESULTS: Of the 329 practitioners who were contacted, 87 participated in the survey. Most participants specialized in anesthesiology (77.0%), worked in a private practice or private hospital (74.7%), and had been practicing pain management for more than 10 years (64.4%). Morphine was the most frequently used opioid for the initiation of intrathecal therapy (80.7% of practitioners), and 81.9% had used ziconotide in their practice. Most practitioners (63.9%) had treated at least one patient who developed a granuloma, and 66.0% of those practitioners had a patient experience permanent or temporary neurological injury due to a granuloma. Fewer than half of practitioners were satisfied with reimbursement from private insurance companies (25.3%) or workers compensation (34.9%), and 90.5% believed reimbursement rates for filling, refilling, and programming patient pumps are not adequate to cover practice costs. The majority of practitioners (56.6%) use fewer pumps in their practices because of reimbursement issues. CONCLUSIONS: Intrathecal pain management practices continue to evolve as the options for treatment increase, and the body of applicable scientific literature grows; however, economic considerations can influence clinical decisions and may interfere with treatment choice and patient access to therapy.

"On the shoulders of giants": a history of the understandings of pain, leading to the understandings of neuromodulation.

The history of the use of electrical stimulation for pain is a cavalcade of research and innovation of many great scholars, scientists, and physicians over centuries that continues up to the present day. The legacy of this philosophy, research, and innovation is the field of neuromodulation for pain control. Today, patients with chronic pain from damage to the nervous system and chronic pain of the extremities, the axial low back, and neck, the face, and the viscera, all derive benefit from these early pioneers that have led to the expanding field of neuromodulation ... "on the shoulders of giants." We present here a history of the understandings of pain from the ancients to the present, which has led to our understandings of the use of electricity to cure disease and release patients from their suffering, generating the new, exciting, and expanding field of neuromodulation.