End-on versus parallel radiofrequency lesioning for neurotomy of the cervical medial branch nerves: a study protocol of a prospective, randomized, double-blind clinical trial: the "EndPaRL" study.

BACKGROUND: Cervical facet joint disease is a common source of neck pain and its prevalence increases with aging. Conservative multimodal management options (e.g., strengthening of neck muscles, non-steroidal anti-inflammatory medications, massage, and thermal modalities) often fail to relieve pain. Cervical medial branch nerve (CMBN) radiofrequency neurotomy (RFN) is an effective minimally invasive technique for treating chronic neck pain secondary to facet joint disease. An end-on approach for this procedure has been proposed that may be technically easier and require less time while reducing post-procedural discomfort. The protocol presented here is for a study that aims to compare the efficacy of a new end-on approach using multi-tined cannulae, against the conventional parallel technique that employs straight cannulae for RFN of the CMBN in patients with chronic neck pain due to cervical facet joint disease. METHODS: A multicentre randomized, non-inferior, active comparator-controlled trial will be conducted with two parallel groups and blinding of participants and outcome assessor. The study will include 72 adults with chronic neck pain secondary to facet joint disease who are candidates for RFA of the CMBN. Participants will be randomized to either the conventional parallel or the end-on approach in a 1:1 ratio. The intensity of pain and pain-related domains (function, quality of life, sleep, adverse effects of the interventions, analgesic intake) will be measured at 1, 3, 6, and 12 months after the procedure. DISCUSSION: Neck pain secondary to cervical facet joint disease is prevalent and RFA of the CMBN is a validated treatment for relieving it. The conventional parallel technique can be technically challenging, and it can be associated with adverse effects while the newer end-on approach has the potential of being a simpler technique with less adverse effects. This trial will be the first non-inferiority study to compare the clinical efficacy of the end-on approach against the conventional parallel approach for RFN of CMBN in patients with chronic neck pain due to cervical facet joint disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT05818774. Registered on April 20, 2023.

A systematic review of the efficacy of ketamine for craniofacial pain.

Background: Craniofacial pain (CFP) poses a burden on patients and health care systems. It is hypothesized that ketamine, an N-methyl-d-aspartate (NMDA) receptor antagonist, can reverse central sensitization associated with causation and propagation of CFP. This systematic review aims to assess the role of ketamine for CFP. Methods: Databases were searched for studies published up to September 26, 2022, investigating the efficacy of ketamine for adults with CFP. Primary outcome was the change in pain intensity at 60 min postintervention. Two reviewers screened and extracted data. Registration with PROSPERO was performed (CRD42020178649). Results: Twenty papers (six randomized controlled trials [RCTs], 14 observational studies) including 670 patients were identified. Substantial heterogeneity in terms of study design, population, dose, route of administration, treatment duration, and follow-up was noted. Bolus dose ranged from 0.2-0.3 mg/kg (intravenous) to 0.4 mg/kg (intramuscular) to 0.25-0.75 mg/kg (intranasal). Ketamine infusions (0.1-1 mg/kg/h) were given over various durations. Follow-up was short in RCTs (from 60 min to 72 h) but longer in observational studies (up to 18 months). Ketamine by bolus treatment failed to reduce migraine intensity but had an effect by reducing intensity of aura, cluster headache (CH), and trigeminal neuralgia. Prolonged ketamine infusions showed sustainable reduction of migraine intensity and frequency of CH attacks, but the quality of the evidence is low. Conclusion: Current evidence remains conflicting on the efficacy of ketamine for CFP owing to low quality and heterogeneity across studies. Ketamine infusions are suggested to provide sustained improvement, possibly because of prolonged duration and higher dosage of administration. RCTs should focus on the dose-response relationship of prolonged ketamine infusions on CFP.

Contexte: La douleur crânio-faciale représente un fardeau pour les patients et les systèmes de soins de santé. L'hypothèse a été émise que la kétamine, un antagoniste du récepteur N-méthyl-D-aspartate (NMDA), peut inverser la sensibilisation centrale associée à la causalité et à la propagation de la douleur crânio-faciale. Cette revue systématique vise à évaluer le rôle de la kétamine dans la douleur crânio-faciale.Méthodes: Les bases de données ont été consultées pour y repérer les études publiées jusqu'au 26 septembre 2022 qui portaient sur l'efficacité de la kétamine chez les adultes atteints de douleur crânio-faciale. Le critère de jugement principal était le changement de l'intensité de la douleur 60 minutes après l'intervention. Deux évaluateurs ont examiné et extrait les données. L'inscription auprès de PROSPERO a été réalisée (CRD42020178649).Résultats: Vingt articles (six essais contrôlés randomisés, 14 études observationnelles) incluant 670 patients ont été répertoriées. Une hétérogénéité considérable en matière de devis d'étude, de population, de dose, de voie d'administration, de durée du traitement et de suivi a été notée. La dose bolus variait de 0,2 à 0,3 mg/kg (voie intraveineuse) à 0,4 mg/kg (voie intramusculaire) et à 0,25-0,75 mg/kg (voie intranasale). Les perfusions de kétamine (0,1-1 mg/kg/h) étaient administrées sur différentes durées. Le suivi était court dans les études contrôllées randomisées (de 60 min à 72 h) mais plus long dans les études observationnelles (jusqu'à 18 mois). La kétamine par traitement bolus n'a pas réussi à réduire l'intensité de la migraine mais a eu un effet en réduisant l'intensité de l'aura, la céphalée en grappe et la névralgie du trijumeau. Les perfusions de kétamine prolongées ont montré une réduction durable de l'intensité de la migraine et la fréquence des crises de CH, mais la qualité des données probantes est faible.Conclusions: Les données probantes actuelles demeurent contradictoires sur l'efficacité de la kétamine pour la douleur crânio-faciale en raison de la faible qualité et de l'hétérogénéité des études. Il est suggéré que les perfusions de kétamine procurent une amélioration soutenue, peut-être en raison de leur durée prolongée et de leur posologie d'administration plus élevée. Les essais contrôlés randomisés devraient se concentrer sur la relation dose-réponse des perfusions prolongées de kétamine sur la douleur crâno-faciale.

Review of Ultrasound-Guided Procedures in the Management of Chronic Pain.

This article summarizes clinical expert recommendations and findings for the application of ultrasound-guided procedures in chronic pain management. Data on analgesic outcomes and adverse effects were collected and analyzed and are reported in this narrative review. Ultrasound guidance offers opportunities for the treatment of pain, with focus in this article on greater occipital nerve, trigeminal nerves, sphenopalatine ganglion, stellate ganglion, suprascapular nerve, median nerve, radial nerve, ulnar nerve, transverse abdominal plane block, quadratus lumborum, rectus sheath, anterior cutaneous abdominal nerves, pectoralis and serratus plane, erector spinae plane, illioinguinal/iliohypogastric/genitofemoral nerve, lateral femoral cutaneous nerve, genicular nerve, and foot and ankle nerves.

A Scoping Review of Epidural Spinal Cord Stimulation for Improving Motor and Voiding Function Following Spinal Cord Injury.

Objectives: To identify and synthesize the existing evidence on the effectiveness and safety of epidural spinal cord stimulation (SCS) for improving motor and voiding function and reducing spasticity following spinal cord injury (SCI). Methods: This scoping review was performed according to the framework of Arksey and O'Malley. Comprehensive serial searches in multiple databases (MEDLINE, Embase, Cochrane Central, Cochrane Database of Systematic Reviews, LILACS, PubMed, Web of Science, and Scopus) were performed to identify relevant publications that focused on epidural SCS for improving motor function, including spasticity, and voiding deficits in individuals with SCI. Results: Data from 13 case series including 88 individuals with complete or incomplete SCI (American Spinal Injury Association Impairment Scale [AIS] grade A to D) were included. In 12 studies of individuals with SCI, the majority (83 out of 88) demonstrated a variable degree of improvement in volitional motor function with epidural SCS. Two studies, incorporating 27 participants, demonstrated a significant reduction in spasticity with SCS. Two small studies consisting of five and two participants, respectively, demonstrated improved supraspinal control of volitional micturition with SCS. Conclusion: Epidural SCS can enhance central pattern generator activity and lower motor neuron excitability in individuals with SCI. The observed effects of epidural SCS following SCI suggest that the preservation of supraspinal transmission is sufficient for the recovery of volitional motor and voiding function, even in patients with complete SCI. Further research is warranted to evaluate and optimize the parameters for epidural SCS and their impact on individuals with differing degrees of severity of SCI.

Spontaneous intracranial hypotension due to CSF-venous fistula: Evaluation of renal accumulation of contrast following decubitus myelography and maintained decubitus CT to improve fistula localization.

PURPOSE: Presented here is a strategy of sequential lateral decubitus digital subtraction myelography (LDDSM) followed closely by lateral decubitus CT (LDCT) to facilitate cerebrospinal fluid (CSF)-venous fistula (CVF) localization. MATERIALS AND METHODS: This is a retrospective analysis of patients referred to our institution for evaluation of CSF leak. Patients with Type 1 and Type 2 leaks, and those not displaying MR brain stigmata of intracranial hypotension were excluded. All patients underwent consecutive LDDSM and LDCT. If the CVF was not localized on the first LDDSM-LDCT pair the patient returned for contralateral examinations. Images were reviewed for CVF and for accumulation of contrast within the renal pelvises expressed as a renal pelvis contrast score (RPCS) in Hounsfield units (HU). RESULTS: Twenty-two patients were included in this study. In 21 of 22 patients (95%) a CVF was identified yielding an RPCS for the LDDSM-LDCT pair ipsilateral to the CVF ranging from 71 to 423 with an average of 146 HU. An RPCS of the negative side LDDSM-LDCT pair contralateral to a CVF was available in 8 patients and averaged 51 HU. In 4 patients the initial bilateral LDDSM-LDCT pairs did not reveal the location of the CVF however in 3 of these 4 cases the CVF was revealed on a third LDDSM repeated ipsilateral to the higher RPCS. CONCLUSION: The strategy of sequential LDDSM-LDCT coupled with evaluation of renal accumulation of contrast agent appears to improve the rate of CVF localization and warrants further evaluation.

Trial protocol for a multicenter randomized controlled trial to assess the efficacy and safety of intravenous ketamine for chronic daily headaches: the "KetHead" trial.

BACKGROUND: Chronic daily headaches (CDH) are common and associated with significant morbidity, poor quality of life, and substantial burden on the healthcare system. CDH tends to be refractory to conventional medical management and/or patients cannot afford expensive treatments. It is stipulated that CDH share a mechanism of central sensitization in the trigeminocervical complex, mediated by activation of the N-methyl-D-aspartate (NMDA) receptors. Ketamine, a non-competitive NMDA antagonist, has been used in the treatment of chronic pain, but its role in CDH has not been completely established. This trial aims to evaluate the effect of high-dose IV ketamine infusions (compared to placebo) on the number of headache days at 28 days post-infusion. METHODS: A multicenter, placebo-controlled, randomized controlled trial will be conducted with two parallel groups and blinding of participants and outcome assessors. The study will include 56 adults with a CDH diagnosis as per ICHD-3 criteria. Participants will be randomized (1:1) to either ketamine (1 mg. kg-1 bolus followed by infusion of 1 mg. kg-1. h-1 for 6 h) or placebo (0.9% saline in the same volume and infusion rate as the trial medication) bolus and infusion for 6 h. The impact on the number of monthly headache days, headache intensity, physical activity, mood, sleep, quality of life, analgesic consumption, and adverse effects will be recorded at baseline, immediately post-infusion, and from 1 to 28 days, 29 to 56 days, and 57 to 84 days after the infusion DISCUSSION: Despite advancements in treatment, many patients continue to suffer from CDH. This trial investigates whether high-dose IV ketamine infusions can effectively and safely improve the CDH burden as compared to a placebo infusion. This treatment could become a safe, affordable, and widely available option for patients living with refractory headache. TRIAL REGISTRATION: ClinicalTrials.gov NCT05306899. Registered on April 1, 2022.

Stellate ganglion block for non-pain indications: a scoping review.

INTRODUCTION: Stellate ganglion block (SGB) is performed to relieve head, face, neck, or upper limb pain, and several non-pain indications for performing this block have emerged over the years. To date, there has been no attempt to synthesize evidence on SGB for treating non-pain indications. This scoping review presents a summary of the efficacy and adverse effects of SGB when performed for 6 non-pain indications. METHODS: This scoping review was accomplished through the use of Arksey and O'Malley framework. A literature search was conducted for relevant articles in medical databases to identify publications on SGB and specified study types. Two reviewers independently assessed the risk of bias for randomized controlled trials, nonrandomized comparative studies, and case series. Results were summarized and recommendations were made on the basis of the strength of the available evidence according to the US Preventative Services Task Force grading system. RESULTS: Twenty-four studies (19 randomized controlled trials and 5 nonrandomized studies) were included in this review. On the basis of the evidence, SGB is recommended for obtunding cardiovascular sympathetic stimulation, improving perfusion in limbs, and alleviating menopausal symptoms with a Grade B or C recommendation and a moderate-to-low level of certainty. There was insufficient evidence to recommend SGB for the other indications. CONCLUSIONS: SGB can be considered for obtunding cardiovascular sympathetic stimulation and stress response, reducing vascular tone to improve vascular insufficiency in the limbs and perioperative hemodynamic stability, and alleviating hot flashes in menopause, in conditions refractory to conventional medical management.

A systematic review and meta-analysis of radiofrequency procedures on innervation to the shoulder joint for relieving chronic pain.

BACKGROUND AND OBJECTIVE: Studies have reported relief of chronic shoulder pain with non-ablative pulsed neuromodulatory (pRF) or ablative radiofrequency (aRF) procedures on innervation of the shoulder joint but interpretation of these reports is hampered by inconsistent indications, anatomic targets and follow-up. This systematic review was conducted to synthesize the existing literature on procedures employing pRF or aRF for treating chronic shoulder pain. DATABASES AND DATA TREATMENT: MEDLINE and other medical literature databases were reviewed up to 31 December 2019 for publications on pRF or aRF procedures on shoulder joint innervation to relieve chronic pain. Data on analgesic and functional outcomes measured at any time point following the interventions were extracted. Existing knowledge on innervation of the shoulder joint with relevance to RF procedures was also synthesized. RESULTS: In all, 42 publications, 7 randomized controlled trials (RCTs) and 35 observational studies, case series or reports were identified. Thirty-six of these publications were on pRF procedure and 29 of these reported procedures exclusively targeting the suprascapular nerve. A meta-analysis of the seven RCTs evaluating pRF indicated no analgesic benefit or functional improvement with this treatment over conventional medical management. Case series and reports on aRF indicate a potential for analgesic benefit but the quality of this evidence was low. CONCLUSIONS: RF treatments targeting the sensory innervation of the shoulder joint affected by degenerative conditions have the potential to reduce pain but the current evidence does not suggest analgesic or functional benefit (GRADE certainty of evidence-low). Studies of high methodological quality are required to further investigate the role of these interventions. SIGNIFICANCE: This is a comprehensive review of literature on pulsed (non-ablative) and ablative radiofrequency (RF) procedures for chronic shoulder pain. The systematic review and meta-analysis of 7 trials found that pulsed RF for chronic shoulder pain provided similar analgesia and functional improvement as conservative medical management at three months after the procedures. The case series and reports on ablative RF for shoulder pain indicate possible analgesic benefit but their quality was low. This review highlights the need for studies of a high quality on ablative RF treatments for chronic shoulder pain.

Factors associated with success and failure of patient-controlled oral analgesia after total hip and knee arthroplasty: a historical comparative cohort study.

PURPOSE: Patient-controlled oral analgesia (PCOA) is a novel method of oral opioid administration using set doses of short-acting oral opioids self-administered by patients with a "lockout" period as part of a multimodal regimen. Failure of PCOA can result in severe postoperative pain necessitating use of intravenous patient-controlled analgesia (IV-PCA) with its potential complications. This study evaluated factors related to success or failure of PCOA following total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: We conducted a retrospective cohort study of all adults who underwent THA and TKA at our institution by extracting data from the proprietary database of our acute pain service. Patient, anesthetic, and surgical variables associated with PCOA failure defined as inadequate analgesia requiring conversion to IV-PCA within 24 hr following THA and TKA were evaluated. Univariable and multivariable logistic regression analyses were performed to identify predictors of PCOA failure. RESULTS: Of the 926 patients who underwent THA or TKA (n = 411 and 515, respectively), 147 (15.9%) patients (67 THA and 80 TKA patients) had PCOA failure with moderate-to-severe pain. Multivariable regression analysis showed that PCOA failure occurred in those with younger age (adjusted odds ratio [aOR] per year of age, 0.97; 99% CI, 0.95 to 0.99; P < 0.001), preoperative chronic use of controlled-release opioids (aOR, 3.45; 99% CI, 1.60 to 7.35; P < 0.001), and with the use of general anesthesia vs spinal anesthesia (aOR, 2.86; 99% CI, 1.20 to 6.84; P = 0.002). CONCLUSION: The use of PCOA provides adequate analgesia to a majority of patients undergoing THA and TKA. Factors predictive for PCOA failure should be considered when choosing the primary breakthrough analgesic modality following THA/TKA.

RéSUMé: OBJECTIF: L'analgésie orale contrôlée par le patient (AOCP) est une méthode novatrice d'administration d'opioïdes oraux qui utilise des doses pré-établies d'opioïdes oraux à courte action auto-administrées par les patients avec un intervalle minimal entre les doses dans le cadre d'un régime multimodal. Le non-fonctionnement d'une AOCP peut entraîner une douleur postopératoire grave nécessitant le recours à une analgésie intraveineuse contrôlée par le patient (ACP-IV), ce qui s'accompagne de complications potentielles. Cette étude a évalué les facteurs liés à la réussite ou à l'échec de l'AOCP à la suite d'une arthroplastie totale de la hanche (ATH) ou du genou (ATG). MéTHODE: Nous avons réalisé une étude de cohorte rétrospective de tous les adultes ayant subi une ATH ou une ATG dans notre établissement en extrayant les données de la base de données de notre service de douleur aiguë. Les variables liées au patient, à l'anesthésie, et à la chirurgie et associées à un échec de l'AOCP, défini comme une analgésie inadéquate exigeant la conversion en ACP-IV dans les 24 heures suivant l'ATH ou l'ATG, ont été évaluées. Des analyses de régression logistique univariée et multivariée ont été effectuées pour identifier les prédicteurs d'un échec de l'AOCP. RéSULTATS: Sur les 926 patients ayant subi une ATH ou une ATG (n = 411 et 515, respectivement), l'AOCP n'a pas fonctionné chez 147 (15,9 %) patients (67 patients d'ATH et 80 d'ATG), entraînant une douleur modérée à grave. L'analyse de régression multivariée a montré que les échecs de l'AOCP sont survenus chez les personnes plus jeunes (rapport de cotes ajusté [RCA] par année d'âge, 0,97; IC 99 %, 0,95 à 0,99; P < 0,001), lors d'une utilisation préopératoire chronique d'opioïdes à libération contrôlée (RCA, 3,45; IC 99 %, 1,60 à 7,35; P < 0,001), et lors d'une anesthésie générale vs une rachianesthésie (RCA, 2,86; IC 99 %, 1,20 à 6,84; P = 0,002). CONCLUSION: L'utilisation de l'AOCP procure une analgésie adéquate à la majorité des patients subissant une ATH ou une ATG. Les facteurs prédictifs d'un échec de l'AOCP devraient être pris en considération lors du choix de la principale modalité analgésique après une ATH/ATG.

Thoracolumbar Interfascial Plane Block for Spinal Cord Stimulator System Implantation: A Case Series.

Thoracolumbar interfascial plane block (TLIPB) has recently been described for postoperative analgesia after thoracolumbar spine surgery. This block is minimally invasive, relatively safe, and easy to perform. TLIPB can potentially decrease opioid requirements and enhance recovery following spine surgery. We describe the sonoanatomic landmarks of this technique, and we report results of this retrospective case series on analgesic impact of this block in patients undergoing implantation of spinal cord stimulation systems. Clinical studies are required to investigate the analgesic role of TLIPB for spinal thoracolumbar surgery.

Quality of chronic pain interventional treatment guidelines from pain societies: Assessment with the AGREE II instrument.

BACKGROUND AND OBJECTIVE: Procedures to relieve pain are performed frequently but there are concerns about patient selection, appropriate image guidance, frequency and training for physicians. Patients, healthcare providers, policymakers and licensing bodies seek evidence-based recommendations to use these interventions judiciously. In this review we appraised the methodological quality of recent clinical practice guidelines (CPGs) for interventional pain procedures. DATABASE AND DATA TREATMENT: A systematic search of the medical literature was performed. Three trained appraisers independently evaluated the methodological quality of the CPGs using a validated instrument, the Appraisal of Guidelines in Research and Evaluation II (AGREE II). Six domains were considered: 1) score and purpose; 2) stakeholder involvement; 3) rigour of development; 4) clarity of presentation; 5) applicability and 6) editorial independence. A total of 23 items were scored. CPGs were deemed 'high quality' if a mean scaled score above 60% for rigour of development and for two other domains was obtained. RESULTS: Mean scaled domain quality scores ranged from 61.72% to 69.99%. Despite being based on modest levels of evidence, two of the four included CPGs were considered to be of high methodological quality. The AGREE II scores across the four guidelines exhibited good inter-rater reliability. None of the guidelines involved key stakeholders such as patients, other healthcare providers, and payers. CONCLUSIONS: All four CPGs were limited by a weak execution of the guideline development process. There is a need to develop methodologically sound evidence-based guidelines for the use of interventional pain procedures using a rigorous process that involves all relevant stakeholders. SIGNIFICANCE: This systematic review appraises the methodological quality of existing CPGs on interventional procedures using a validated epidemiological tool (AGREE II). The aims of this review were to identify methodological and knowledge gaps in existing CPGs. Findings of this study will help in development of a high-quality CPG that can assist healthcare providers and patients in making informed decisions while ensuring that the right intervention is performed for the right patient at the right time. The quality of the evidence provided by the CPGs provided in support of their recommendations was also evaluated.

Correction to: A Review of Current Denervation Techniques for Chronic Hip Pain: Anatomical and Technical Considerations.

In the original publication, the legend in the Figure 1 caption were missing and Table 2 was not presented correctly.

A Review of Current Denervation Techniques for Chronic Hip Pain: Anatomical and Technical Considerations.

PURPOSE OF REVIEW: Percutaneous radiofrequency (RF) denervation of articular sensory nerves of the hip joint is a minimally invasive neurotomy technique that can provide pain relief in patients with chronic hip pain. There has been an increase in the number of publications on RF denervation of the hip over the last few years although many questions remain regarding anatomical targets, technical aspects, selection criteria, and evidence for effectiveness. RECENT FINDINGS: For this updated review, publications were identified by searching MEDLINE and other medical literature databases from inception through November 30, 2018. Existing knowledge of hip joint innervation was reviewed and data on patient selection, prognostication of analgesic benefit from ablation by using local anesthetic blocks, current techniques of performing hip joint ablation, analgesic success, functional outcomes, and adverse effects were critically reviewed and analyzed. Sensory denervation of the anterior hip joint using RF current is a viable treatment option for management of chronic hip pain after conservative methods fails to do so. We have synthesized knowledge from papers on techniques of ablation and from recently elaborated anatomical details. We also provide suggestions regarding anticipated outcomes of the procedure. Our review of existing literature indicates evidence for analgesic benefits, improvement in function, and a low incidence of adverse effects of RF ablation of sensory innervation to the hip joint. Future research should focus on refining the technique of ablation and monitoring of long-term outcomes.

Comparison of two ultrasound-guided techniques for greater occipital nerve injections in chronic migraine: a double-blind, randomized, controlled trial.

BACKGROUND AND OBJECTIVES: Two ultrasound (US)-guided techniques for greater occipital nerve (GON) block have been described for the management of headache disorders: a "proximal or central" technique targeting the GON at the level of the second cervical vertebra and a "distal or peripheral" technique targeting the GON at the level of the superior nuchal line. In this multicenter, prospective, randomized control trial, we compared accuracy, effectiveness, and safety of these two techniques in patients with chronic migraines (CMs). METHODS: Forty patients with refractory CMs were randomized to receive either a proximal or distal US-guided GON block with bupivacaine and methylprednisolone acetate. The primary outcome was the difference in Numerical Rating Score (NRS) for headache intensity at 1 month. Secondary outcomes were effectiveness, performance, and safety-related. Effectiveness-related outcomes included NRS for headache intensity, number of headache days per week, patient satisfaction, quality of life, assessment of sleep quality, and sleep interruption. Performance-related outcomes included procedure time, accuracy of block, and patient discomfort. Safety-related outcomes included an assessment for adverse effects. RESULTS: NRS pain scores were significantly reduced at 24 hours and at 1 week postprocedure in both cohorts and at 1 and 3 months in the proximal group as compared with the baseline. There was no significant difference in NRS pain scores between the two cohorts at any of the follow-up time points. There was a significant reduction in number of headache days per week at 1 month in both groups, and a significant improvement in sleep interruption at 1 week in both groups. There were no significant adverse effects. CONCLUSIONS: This study was designed to compare two different US-guided approaches for blocking the GON. Our results demonstrate that both distal and proximal techniques can provide a short-term improvement in headache intensity, reduction in number of headache days per week, and an improvement in sleep interruption. The proximal GON technique may confer more sustained analgesic benefit compared with the distal approach in patients with CM headaches. TRIAL REGISTRATION NUMBER: NCT02031822.

A scoping review of novel spinal cord stimulation modes for complex regional pain syndrome.

Background: Paresthesia-based spinal cord stimulation (PB-SCS) is used for the treatment of complex regional pain syndrome (CRPS), but many patients are refractory to PB-SCS or experience attenuation of analgesic effect over time due to tolerance. Novel SCS modes including high-frequency, BurstTM, and high-density (HDTM) stimulation were introduced recently and this systematic review was conducted to summarize the evidence on their role for CRPS. Materials and Methods: We searched MEDLINE and other databases (up to September 21, 2017) for studies including adults with refractory CRPS treated by paresthesia-free SCS (PF-SCS) modes compared to placebo, conventional medical treatment, or PB-SCS. We determined the posttreatment intensity of pain (up to 24 months after intervention), changes in CRPS-associated symptoms, and associated domains. Sustainability and adverse effects were also assessed. Results: We identified 13 studies (seven case series, five conference abstracts, one randomized controlled trial) including 62 patients with upper or lower limb CRPS. Eleven papers reported on outcomes of high-frequency stimulation at 10 kHz (HF-10) and other high frequencies, two papers were on Burst, and one paper was on HD. In 59 patients, pain intensity with novel SCS modes was reduced by 30% to 100% with a corresponding reduction in analgesic medications. Novel SCS modes also attenuated CRPS-associated symptoms and six papers reported significant improvement of quality of life. Conclusions: Novel SCS modes have the potential to provide analgesia in patients with CRPS. However, the low quality of available evidence necessitates definitive and prospective comparative effectiveness studies to establish the role of these modes in CRPS.

Contexte: La stimulation médullaire par induction de paresthésies est utilisée pour le traitement du syndrome douloureux régional complexe (SDRC), mais de nombreux patients y sont réfractaires ou ressentent une atténuation de l'effet analgésique avec le temps dû à la tolérance. De nouvelles modalités de stimulation médullaire, dont la stimulation à haute fréquence, la stimulation par rafales (BurstTM) et la stimulation à haute densité (HDTM), ont récemment facommentcé à être utilisés. Cette revue systématique a été menée afin de résumer les données probantes portant sur leur rôle dans le SDRC.Matériel et méthodes: Nous avons fait des recherches dans MEDLINE et d'autres bases de données (jusqu'au 21 septembre 2017) pour trouver des études portant sur des adultes souffrant d'un SDRC réfractaire traité par stimulation médullaire sans parasthésie comparativement à un placebo, à un traitement médical conventionnel ou à une stimulation médullaire par induction de paresthésies. Nous avons déterminé l'intensité post-traitement de la douleur (jusqu'à 24 mois après l'intervention), ainsi que les changements dans les symptômes associés au SDRC et dans des domaines connexes. La pérennité et les effets défavorables ont aussi été évalués.Résultats: Nous avons répertorié 13 études (7 séries de cas, 5 résumés de conférence, un essai contrôlé randomisé) auxquelles ont participé 62 patients souffrant d'un SDRC aux membres supérieurs ou inférieurs. Onze articles portaient sur les résultats de la HF-10 et d'autres hautes fréquences, deux articles portaient sur la stimulation Burst TM et un article portait sur la HDTM. Chez 50 patients, les modalités novatrices de stimulation médullaire ont donné lieu à une diminution de l'intensité de la douleur allant de 30 % à 100 %, accompagnée d'une réduction similaire des médications analgésiques. Les nouveaux modes de stimulation médullaire atténuaient également les symptômes associés au SDRC. De plus, six articles faisaient état d'une amélioration considérable de la qualité de vie.Conclusions: Les nouveaux modes de stimulation médullaire peuvent avoir un effet analgésique pour les patients souffrant d'un SDRC. Toutefois, la qualité médiocre des données probantes disponibles rend nécessaire la conduite d'études comparatives et prospectives sur leur efficacité des afin d'établir leur rôle dans le SDRC.

Echo-guided invasive pain therapy: indications and limitations.

PURPOSE OF REVIEW: The purposes of this review are to summarize the advantages and limitations of ultrasound-guided pain interventions, and to illustrate those interventions with peripheral, axial and musculoskeletal pain procedures. RECENT FINDINGS: With the capability of locating the interfascial plane, ultrasonography has led to the emergence of a series of plane blocks for the thoracoabdominal region in the recent decade.Ultrasonography for musculoskeletal procedures has been of growing interest because of the major advantage of direct visualization and scanning of various soft tissues and real-time spread in the injectate, thereby enhancing precision and efficacy, reducing risk of trauma and avoidance of radiation. For spine and intra-articular structures, ultrasonography is complicated by the bony shadow artefact and often deep location of the structure, making acquisition of ultrasound image challenging. Despite these difficulties, there is growing interest in applying ultrasonography for cervical spine and sacroiliac joint procedures. SUMMARY: Pain intervention under ultrasound guidance is particularly valuable in peripheral and musculoskeletal procedures. There is growing interest of its application in cervical spine and sacroiliac joint. More outcome studies are required in the future to make ultrasound-guided pain intervention as the established procedure.

The analgesic efficacy of intravenous regional anesthesia with a forearm versus conventional upper arm tourniquet: a systematic review.

BACKGROUND: The main objective of this review is to perform a systematic review and meta-analysis of the existing evidence related to the analgesic efficacy with the use of conventional, upper arm intravenous regional anesthesia (IVRA) as compared to a modified, forearm IVRA in adult patients undergoing procedures on the distal upper extremity. METHODS: MEDLINE, EMBASE and CENTRAL (Cochrane) databases were searched for randomized controlled trials published in English, French, Dutch, German or Spanish language. Primary outcomes of interest including description of quality level of anesthesia and onset of sensory block were assessed for this review. Dosage of the local anesthetic, local anesthetic toxicity and need for sedation due to tourniquet pain were considered as secondary outcomes. RESULTS: Our literature search yielded 3 papers for qualitative synthesis. Four other articles were added into a parallel analysis of 7 reports that provided data on the incidence of complications and success rate after forearm IVRA. Forearm IVRA was found to be as efficient as upper arm IVRA (RR = 0.98 [0.93, 1.05], P = 0.78), but comes with the advantage of a lower need for sedation due to less tourniquet pain. CONCLUSION: Our results demonstrate that forearm IVRA is as effective in providing a surgical block as compared to a conventional upper arm IVRA, even with a reduced, non-toxic dosage of local anesthetic. No severe complications were associated with the use of a forearm IVRA. Other benefits of the modified technique include a faster onset of sensory block, better tourniquet tolerance and a dryer surgical field. REGISTRATION OF THE SYSTEMATIC REVIEW: A review protocol was published in the PROSPERO register in November 2015 with registration number CRD42015029536 .

Radiofrequency Procedures to Relieve Chronic Hip Pain: An Evidence-Based Narrative Review.

BACKGROUND AND OBJECTIVES: Chronic hip pain from osteoarthritis and other degenerative conditions is a common problem. A few publications have recently reported analgesic success of radiofrequency (RF) procedures on nerves innervating the hip, but interpretation is hampered by lack of clarity regarding indications, clinical protocols, anatomic targets, and longevity of benefit from RF procedures. METHODS: We reviewed the following medical literature databases for publications on RF procedures on the hip joint for chronic pain: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Google Scholar through February 28, 2017. Existing knowledge on innervation of the hip joint was synthesized. Data on analgesic and functional outcomes and adverse effects measured at any time points following the interventions were also collected, analyzed, and reported in this narrative review. RESULTS: Fourteen publications on ablative RF treatments of innervation of the hip joint were identified. A high success rate of these procedures in relieving chronic pain of the hip joint was reported at 8 days to 36 months after the procedures, but none of the publications were randomized controlled trials. There was evidence for improvement in function and a lack of serious adverse events of RF treatments. CONCLUSIONS: Radiofrequency treatments for the sensory innervation of the hip joint have the potential to reduce pain secondary to degenerative conditions. Ongoing concerns remain regarding the anatomic targets, as well as quality, procedural aspects, and monitoring of outcomes in publications on this topic. Randomized controlled trials of high methodological quality are required to further elaborate the role of these interventions in this population.