Systematic Reviews and Meta-analyses in Regional Anesthesia and Pain Medicine (Part I): Guidelines for Preparing the Review Protocol.

Comprehensive resources exist on how to plan a systematic review and meta-analysis. The objective of this article is to provide guidance to authors preparing their systematic review protocol in the fields of regional anesthesia and pain medicine. The focus is on systematic reviews of health care interventions, with or without an aggregate data meta-analysis. We describe and discuss elements of the systematic review methodology that review authors should prespecify, plan, and document in their protocol before commencing the review. Importantly, authors should explain their rationale for planning their systematic review and describe the PICO framework-participants (P), interventions (I), comparators (C), outcomes (O)-and related elements central to constructing their clinical question, framing an informative review title, determining the scope of the review, designing the search strategy, specifying the eligibility criteria, and identifying potential sources of heterogeneity. We highlight the importance of authors defining and prioritizing the primary outcome, defining eligibility criteria for selecting studies, and documenting sources of information and search strategies. The review protocol should also document methods used to evaluate risk of bias, quality (certainty) of the evidence, and heterogeneity of results. Furthermore, the authors should describe their plans for managing key data elements, the statistical construct used to estimate the intervention effect, methods of evidence synthesis and meta-analysis, and conditions when meta-analysis may not be possible, including the provision of practical solutions. Authors should provide enough detail in their protocol so that the readers could conduct the study themselves.

The practice of regional anesthesia during the COVID-19 pandemic: an international survey of members of three regional anesthesia societies.

PURPOSE: To determine the preferences and attitudes of members of regional anesthesia societies during the COVID-19 pandemic. METHODS: We distributed an electronic survey to members of the American Society of Regional Anesthesia and Pain Medicine, Regional Anaesthesia-UK, and the European Society of Regional Anaesthesia & Pain Therapy. A questionnaire consisting of 19 questions was developed by a panel of experienced regional anesthesiologists and distributed by email to the participants. The survey covered the following domains: participant information, practice settings, preference for the type of anesthetic technique, the use of personal protective equipment, and oxygen therapy. RESULTS: The survey was completed by 729 participants from 73 different countries, with a response rate of 20.1% (729/3,630) for the number of emails opened and 8.5% (729/8,572) for the number of emails sent. Most respondents (87.7%) identified as anesthesia staff (faculty or consultant) and practiced obstetric and non-obstetric anesthesia (55.3%). The practice of regional anesthesia either expanded or remained the same, with only 2% of respondents decreasing their use compared with the pre-pandemic period. The top reasons for an increase in the use of regional anesthesia was to reduce the need for an aerosol-generating medical procedure and to reduce the risk of possible complications to patients. The most common reason for decreased use of regional anesthesia was the risk of urgent conversion to general anesthesia. Approximately 70% of the responders used airborne precautions when providing care to a patient under regional anesthesia. The most common oxygen delivery method was nasal prongs (cannula) with a surgical mask layered over it (61%). CONCLUSIONS: Given the perceived benefits of regional over general anesthesia, approximately half of the members of three regional anesthesia societies seem to have expanded their use of regional anesthesia techniques during the initial surge of the COVID-19 pandemic.

RéSUMé: OBJECTIF: Déterminer les préférences et les attitudes des membres des sociétés d'anesthésie régionale pendant la pandémie de COVID-19. MéTHODE: Nous avons distribué un sondage électronique aux membres de l'American Society of Regional Anesthesia and Pain Medicine, de Regional Anesthesia-UK et de l'European Society of Regional Anaesthesia & Pain Therapy. Un questionnaire composé de 19 questions a été élaboré par un panel d'anesthésiologistes régionaux d'expérience et distribué par courriel aux participants. Le sondage couvrait les domaines suivants : les renseignements sur les participants, les contextes de pratique, leur préférence quant au type de technique d'anesthésie, l'utilisation d'équipement de protection individuelle et l'oxygénothérapie RéSULTATS: Le sondage a été complété par 729 participants provenant de 73 pays différents, avec un taux de réponse de 20,1 % (729/3630) pour le nombre de courriels ouverts et de 8,5 % (729/8572) pour le nombre de courriels envoyés. La plupart des répondants (87,7 %) se sont identifiés comme anesthésiologistes (académique ou consultant) et pratiquaient l'anesthésie obstétricale et non obstétricale (55,3 %). Leur pratique de l'anesthésie régionale s'est étendue ou est demeurée inchangée, et seulement 2 % des répondants ont indiqué avoir diminué leur utilisation de cette pratique par rapport à la période pré-pandémique. Les principales raisons d'une augmentation de l'utilisation de l'anesthésie régionale étaient de réduire la nécessité d'une intervention médicale générant des aérosols et de réduire le risque de complications potentielles pour les patients. La raison la plus courante de diminution du recours à l'anesthésie régionale était le risque de conversion urgente à une anesthésie générale. Environ 70 % des intervenants ont utilisé des précautions en matière de propagation des aérosols lorsqu'ils procuraient des soins à un patient sous anesthésie régionale. La méthode d'administration d'oxygène la plus fréquemment utilisée était les canules nasales avec un masque chirurgical superposé (61 %). CONCLUSION: Compte tenu des avantages perçus de l'anesthésie régionale par rapport à l'anesthésie générale, environ la moitié des membres de trois sociétés d'anesthésie régionale semblent avoir élargi leur utilisation des techniques d'anesthésie régionale pendant la vague initiale de la pandémie de COVID-19.

Recommended Musculoskeletal and Sports Ultrasound Terminology: A Delphi-Based Consensus Statement.

OBJECTIVES: The current lack of agreement regarding standardized terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice, and research. This consensus was developed to provide a reference to improve clarity and consistency in communication. METHODS: A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus which was defined as group level agreement >80%. RESULTS: Content was organized into seven general topics including: 1) General Definitions, 2) Equipment and Transducer Manipulation, 3) Anatomic and Descriptive Terminology, 4) Pathology, 5) Procedural Terminology, 6) Image Labeling, and 7) Documentation. Terms and definitions which reached consensus agreement are presented herein. CONCLUSIONS: The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients, and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

Recommended musculoskeletal and sports ultrasound terminology: a Delphi-based consensus statement.

The current lack of agreement regarding standardised terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice and research. This consensus was developed to provide a reference to improve clarity and consistency in communication. A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus, which was defined as group level agreement of >80%. Content was organised into seven general topics including: (1) general definitions, (2) equipment and transducer manipulation, (3) anatomical and descriptive terminology, (4) pathology, (5) procedural terminology, (6) image labelling and (7) documentation. Terms and definitions which reached consensus agreement are presented herein. The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

Consensus practice guidelines on interventions for cervical spine (facet) joint pain from a multispecialty international working group.

BACKGROUND: The past two decades have witnessed a surge in the use of cervical spine joint procedures including joint injections, nerve blocks and radiofrequency ablation to treat chronic neck pain, yet many aspects of the procedures remain controversial. METHODS: In August 2020, the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine approved and charged the Cervical Joint Working Group to develop neck pain guidelines. Eighteen stakeholder societies were identified, and formal request-for-participation and member nomination letters were sent to those organizations. Participating entities selected panel members and an ad hoc steering committee selected preliminary questions, which were then revised by the full committee. Each question was assigned to a module composed of 4-5 members, who worked with the Subcommittee Lead and the Committee Chairs on preliminary versions, which were sent to the full committee after revisions. We used a modified Delphi method whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chairs, who incorporated the comments and sent out revised versions until consensus was reached. Before commencing, it was agreed that a recommendation would be noted with >50% agreement among committee members, but a consensus recommendation would require ≥75% agreement. RESULTS: Twenty questions were selected, with 100% consensus achieved in committee on 17 topics. Among participating organizations, 14 of 15 that voted approved or supported the guidelines en bloc, with 14 questions being approved with no dissensions or abstentions. Specific questions addressed included the value of clinical presentation and imaging in selecting patients for procedures, whether conservative treatment should be used before injections, whether imaging is necessary for blocks, diagnostic and prognostic value of medial branch blocks and intra-articular joint injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for designating a block as positive, how many blocks should be performed before radiofrequency ablation, the orientation of electrodes, whether larger lesions translate into higher success rates, whether stimulation should be used before radiofrequency ablation, how best to mitigate complication risks, if different standards should be applied to clinical practice and trials, and the indications for repeating radiofrequency ablation. CONCLUSIONS: Cervical medial branch radiofrequency ablation may provide benefit to well-selected individuals, with medial branch blocks being more predictive than intra-articular injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of false-negatives (ie, lower overall success rate). Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations on Bleeding and Coagulation Management in Neurostimulation Devices.

INTRODUCTION: The Neurostimulation Appropriateness Consensus Committee (NACC) was formed by the International Neuromodulation Society (INS) in 2012 to evaluate the evidence to reduce the risk of complications and improve the efficacy of neurostimulation. The first series of papers, published in 2014, focused on the general principles of appropriate practice in the surgical implantation of neurostimulation devices. The NACC was reconvened in 2014 to address specific patient care issues, including bleeding and coagulation. METHODS: The INS strives to improve patient care in an evidence-based fashion. The NACC members were appointed or recruited by the INS leadership for diverse expertise, including international clinical expertise in many areas of neurostimulation, evidence evaluation, and publication. The group developed best practices based on peer-reviewed evidence and, in the absence of specific evidence, on expert opinion. Recommendations were based on international evidence in accordance with guideline creation. CONCLUSIONS: The NACC has recommended specific measures to reduce the risk of bleeding and neurological injury secondary to impairment of coagulation in the setting of implantable neurostimulation devices in the spine, brain, and periphery.

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 Neurostimulation Appropriateness Consensus Committee (NACC) Safety Guidelines for the Reduction of Severe Neurological Injury.

INTRODUCTION: Neurostimulation involves the implantation of devices to stimulate the brain, spinal cord, or peripheral or cranial nerves for the purpose of modulating the neural activity of the targeted structures to achieve specific therapeutic effects. Surgical placement of neurostimulation devices is associated with risks of neurologic injury, as well as possible sequelae from the local or systemic effects of the intervention. The goal of the Neurostimulation Appropriateness Consensus Committee (NACC) is to improve the safety of neurostimulation. METHODS: The International Neuromodulation Society (INS) is dedicated to improving neurostimulation efficacy and patient safety. Over the past two decades the INS has established a process to use best evidence to improve care. This article updates work published by the NACC in 2014. NACC authors were chosen based on nomination to the INS executive board and were selected based on publications, academic acumen, international impact, and diversity. In areas in which evidence was lacking, the NACC used expert opinion to reach consensus. RESULTS: The INS has developed recommendations that when properly utilized should improve patient safety and reduce the risk of injury and associated complications with implantable devices. CONCLUSIONS: On behalf of INS, the NACC has published recommendations intended to reduce the risk of neurological injuries and complications while implanting stimulators.

Occipital Neuralgia Diagnosis and Treatment: The Role of Ultrasound.

BACKGROUND: Occipital neuralgia is a form of neuropathic type of pain in the distribution of the greater, lesser, or third occipital nerves. Patients with intractable occipital neuralgia do not respond well to conservative treatment modalities. This group of patients represents a significant therapeutic challenge and may require interventional or invasive therapeutic approaches. PURPOSE: Occipital neuralgia frequently occurs as a result of nerve entrapment or irritation by a tight muscle or vascular structure, or nerve trauma during whiplash injury. Although the entrapment theory is most commonly accepted, it lacks strong clinical evidence to support it. Accordingly, the available interventional approaches have been targeting the accessible part of the occipital nerve rather than the entrapped part. CONCLUSION: Bedside sonography is an excellent imaging modality for soft tissue structures. Ultrasound not only allows distinguishing normal from abnormal entrapped occipital nerves, it can identify the level and the cause of entrapment as well. Ultrasound guidance allows precise occipital nerve blocks and interventions at the level of the "specific" entrapment location rather than into the site of "presumed" entrapment.

An International Survey to Understand Infection Control Practices for Spinal Cord Stimulation.

OBJECTIVES: Surgical site infections (SSIs) are associated with significant healthcare costs and morbidity. Limited research exists specific to the prevention of spinal cord stimulation (SCS) SSIs. The objectives of this international survey were to examine current infection control practices for SCS trials and implants and to compare reported responses with evidence-based recommendations. MATERIALS AND METHODS: A 33-question survey was developed based on an extensive literature review for infection control policies. The survey was hosted on the Internet. Dispersion of the survey occurred through professional associations and device manufacturers. Responses to 15 questions directly related to defined CDC, NICE, and SCIP evidence-based infection control practice recommendations were classified as either compliant or noncompliant. The survey was open for 20 days. Responses also were grouped and analyzed based on geographic location, practice location, and procedural volumes. RESULTS: Five hundred six physicians responded to the survey. Compliance rates for CDC, NICE, SCIP infection control practice recommendations were low with only four of the 15 questions having compliance rates ≥80%. Areas associated with high levels of noncompliance included weight-based antibiotic dosing, hair removal strategies, double gloving, surgical dressing, skin antiseptic agent selection, and postoperative continuation of antibiotics. Geographic and practice type variations existed for particular infection control practices. Procedural volume influenced operative implant times with low physician procedural volumes associated with extended operative times. CONCLUSIONS: The survey provided significant insight into current practices and will assist in the development of specific SCS infection control policies. Based on the survey, further education is warranted on infection control strategies for physicians performing spinal cord stimulator trials and implants.

Safety and efficacy of peripheral nerve stimulation of the occipital nerves for the management of chronic migraine: long-term results from a randomized, multicenter, double-blinded, controlled study.

BACKGROUND: Recent studies evaluated short-term efficacy and safety of peripheral nerve stimulation (PNS) of the occipital nerves for managing chronic migraine. We present 52-week safety and efficacy results from an open-label extension of a randomized, sham-controlled trial. METHODS: In this institutional review board-approved, randomized, multicenter, double-blinded study, patients were implanted with a neurostimulation system, randomized to an active or control group for 12 weeks, and received open-label treatment for an additional 40 weeks. Outcomes collected included number of headache days, pain intensity, migraine disability assessment (MIDAS), Zung Pain and Distress (PAD), direct patient reports of headache pain relief, quality of life, satisfaction and adverse events. Statistical tests assessed change from baseline to 52 weeks using paired t-tests. Intent-to-treat (ITT) analyses of all patients (N = 157) and analyses of only patients who met criteria for intractable chronic migraine (ICM; N = 125) were performed. RESULTS: Headache days were significantly reduced by 6.7 (±8.4) days in the ITT population (p < 0.001) and by 7.7 (±8.7) days in the ICM population (p < 0.001). The percentages of patients who achieved a 30% and 50% reduction in headache days and/or pain intensity were 59.5% and 47.8%, respectively. MIDAS and Zung PAD scores were significantly reduced for both populations. Excellent or good headache relief was reported by 65.4% of the ITT population and 67.9% of the ICM population. More than half the patients in both cohorts were satisfied with the headache relief provided by the device. A total of 183 device/procedure-related adverse events occurred during the study, of which 18 (8.6%) required hospitalization and 85 (40.7%) required surgical intervention; 70% of patients experienced an adverse event. CONCLUSION: Our results support the 12-month efficacy of PNS of the occipital nerves for headache pain and disability associated with chronic migraine. More emphasis on adverse event mitigation is needed in future research. TRIAL REGISTRATION: Clinical trials.gov (NCT00615342).

Analysis of adverse events in the management of chronic migraine by peripheral nerve stimulation.

OBJECTIVE: In this study, we analyze device- and procedure-related adverse events (AEs) from a recent prospective, multicenter, double-blinded controlled study that utilized peripheral nerve stimulation (PNS) of occipital nerves for management of chronic migraine. METHODS: PNS device characteristics (lead length and spacing), surgical techniques including lead orientation (parallel or perpendicular to the nerve), and implantable pulse generator (IPG) placement (upper buttock, abdomen, infraclavicular, or lower axilla) in 157 patients were analyzed to identify any relationship with the AE incidence rate. Number of prior PNS implants performed (NPPIP) by the implanter and its relationship with different AE categories (hardware-related, biological, and stimulation-related events) and frequently observed device/procedure-related AEs (lead migration/fracture/breakage, persistent pain at the lead/IPG location, unintended/undesirable changes in stimulation, infection) were also evaluated. Three-way ANOVA tests were utilized to evaluate the dependence of AE occurrence on the variables described above. RESULTS: IPG pocket locations closer to the lead (e.g. infraclavicular region) were associated with a lower AE incidence rate (p < 0.05). Higher NPPIP was related to lower stimulation- and hardware-related AEs (p < 0.05), frequently observed AEs like lead migration, pain, and infection (p < 0.05), and procedure-related additional surgeries (p < 0.05). CONCLUSION: Implantation of the IPG closer to the lead location was associated with reduced AEs. PNS is a relatively new procedure, and the skill and precision in performing these procedures improves with experience. Our results demonstrate that as the implanter gains more experience with these procedures, a significant reduction in device- and procedure-related AEs may be expected.

Risk Factors for Chronic Saphenous Neuralgia Following Coronary Artery Bypass Graft Surgery Utilizing Saphenous Vein Grafts.

OBJECTIVES: The aim of this trial was to determine risk factors for chronic saphenous neuralgia (SN) following harvesting of the great saphenous vein (GSV) for coronary artery bypass graft (CABG) surgery. METHODS: In a prospective observational trial, 526 patients with no history of chronic painful disorders or surgery in the lower limbs were followed up for 13 weeks after undergoing CABG surgery in which GSV grafts were used. The primary outcome measure was persistence of clinically significant pain of neuropathic type in the territory supplied by the saphenous nerve beyond 12 weeks after surgery. RESULTS: Eighty-one (15.4%) patients consistently had probable neuropathic pain of clinically significant severity throughout the follow-up period and were labeled as suffering from chronic SN. Multivariable binary logistic regression analysis showed that younger age (OR, 0.92; 95% CI, 0.88-0.95; P-value, < 0.0001), female gender (OR, 2.28; 95% CI, 1.21-4.29; P-value, 0.011), higher body mass index (OR, 1.25; 95% CI, 1.17-1.35; P-value, < 0.0001), diabetes mellitus (OR, 2.13; 95% CI, 1.13-4.01; P-value, 0.020), distal-to-proximal dissection of the GSV (OR, 7.28; 95% CI, 3.62-14.66; P-value, < 0.0001), and closure of the leg wound in two layers (OR, 3.28; 95% CI, 1.81-5.95; P-value, 0.0001) were independent risk factors for chronic SN. CONCLUSIONS: Chronic SN after CABG surgery utilizing GSV grafts is not uncommon. Risk factors identified in this trial are younger age, female gender, higher body mass index, diabetes mellitus, distal-to-proximal dissection of the GSV, and closure of the leg wound in two layers.

Neurostimulation at pterygopalatine fossa for cluster headaches and cerebrovascular disorders.

There are numerous neural structures (parasympathetic, sympathetic, and trigeminal sensory) that are compacted in a small well defined area of the pterygopalatine fossa (PPF). These targets can be readily accessed via minimally invasive neuromodulation techniques making the methods more desirable than neurosurgical deep brain or hypothalamic intervention. Recent research has shed light over the important role of the sphenopalatine ganglion (SPG), which is located within the PPF, in cerebrovascular autonomic physiology as well as in the pathophysiology of different headache disorders (cluster headache, migraine, and trigeminal autonomic cephalalgias). Accordingly, neuromodulation of the autonomic fibers (parasympathetic and sympathetic) may play a key role in the management of headaches, stroke, or cerebral vasospasm. Another important structure within the PPF is the maxillary nerve (V2), which passes through the roof of the fossa. Here the trigeminal system is accessible for a reliable neuromodulation by targeting its second branch -the maxillary nerve- and this could be utilized in various painful conditions of the head and face.

Ultrasound-guided stellate ganglion block: safety and efficacy.

Cervical sympathetic and stellate ganglion blocks (SGB) provide a valuable diagnostic and therapeutic benefit to sympathetically maintained pain syndromes in the head, neck, and upper extremity. With the ongoing efforts to improve the safety of the procedure, the techniques for SGB have evolved over time, from the use of the standard blind technique, to fluoroscopy, and recently to the ultrasound (US)-guided approach. Over the past few years, there has been a growing interest in the ultrasound-guided technique and the many advantages that it might offer. Fluoroscopy is a reliable method for identifying bony surfaces, which facilitates identifying the C6 and C7 transverse processes. However, this is only a surrogate marker for the cervical sympathetic trunk. The ideal placement of the needle tip should be anterolateral to the longus colli muscle, deep to the prevertebral fascia (to avoid spread along the carotid sheath) but superficial to the fascia investing the longus colli muscle (to avoid injecting into the muscle substance). Identifying the correct fascial plane can be achieved with ultrasound guidance, thus facilitating the caudal spread of the injectate to reach the stellate ganglion at C7-T1 level, even if the needle is placed at C6 level. This allows for a more effective and precise sympathetic block with the use of a small injectate volume. Ultrasound-guided SGB may also improve the safety of the procedure by direct visualization of vascular structures (inferior thyroidal, cervical, vertebral, and carotid arteries) and soft tissue structures (thyroid, esophagus, and nerve roots). Accordingly, the risk of vascular and soft tissue injury may be minimized.

Neurostimulation for the treatment of axial back pain: a review of mechanisms, techniques, outcomes, and future advances.

INTRODUCTION: The use of spinal cord stimulation (SCS) is well established in the treatment of neuropathic pain. This procedure has been approved in the United States for neuropathic pain of the trunk and limbs from various conditions. International use is variable based on governmental policy. Most studies showing efficacy have focused on pain primarily in the limbs for such conditions as complex regional pain syndrome (CRPS), sciatica, radiculitis, ischemic limb pain, and peripheral neuropathy. Data on success in neuropathic pain of the trunk and particularly of the axial back are limited. New understanding about the targets of neuromodulation and their treatment with novel neurostimulation approaches has led to a new dawn of enthusiasm for spinal cord stimulation for axial low back pain. METHODS: The authors review mechanisms, current and future targets, techniques, and their outcomes for treating axial back pain with neurostimulation. The paper discusses many newer methods and targets that may substantially improve results for the treatment of this patient group. The continuing evolution of technology and new data may well change these recommendations over time and regular updates of this manuscript will be critical moving forward. CONCLUSIONS: Improved technology and a better understanding of the goals of stimulation have led to a new ability to stimulate the axial low back and increase the effectiveness of these therapies to reduce pain. New paddle lead constructs, percutaneous paddle lead introduction, and other new technologies have led to an increased number of potential candidates for spinal cord stimulation. Optimizing the application of neurostimulation for chronic axial back pain will depend upon answering questions relating to patient selection, implantation technique, and stimulation parameters.

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.