Peripheral neurostimulation for control of intractable occipital neuralgia

Does Peripheral Nerve Stimulator-Guided Extraoral Mandibular Nerve Block Provide Effective Anaesthesia for Third Molar Surgery: A Prospective Interventional Study

Background/Aim

Mandibular nerve block provides good quality and long-lasting analgesia. In situations necessitating extraoral nerve-blocking procedures, clinicians may find it technically challenging to administer this block due to its uncertain surface landmarks or distorted anatomy. Peripheral nerve stimulator is a device used to electrically stimulate the peripheral and terminal branches of the nerve.

Methods

This prospective interventional clinical study was carried out in the Department of Oral and Maxillofacial Surgery, SRM Kattankulathur Dental College And Hospital in patients requiring surgical extraction of mandibular third molar. Patients were divided into two groups: control group and test group based on computer-generated randomization. Control group patients underwent impaction procedure after conventional extraoral mandibular nerve block, while test group patients underwent impaction procedure after PNS-guided extraoral mandibular nerve block.

Results

Statistical analysis was done and the mean length of anaesthesia between the two groups was compared using a paired t test, and the mean pain levels up to six hours were compared using a Wilcoxon signed-rank test. Out of 42 patients, 25 were male and 17 were female. The mean age was 28.36 years. The age range was 19-52 years. In both control and test groups, no patients had failure of anaesthesia, and no one complained of pain during the procedure; hence, no supplemental injections were given. Visual analogue scale score remained (score ≤ 2) up to 6 h for patients in test group.

Conclusion

Thus, using a peripheral nerve stimulator guarantees the success of the block. For patients undergoing third molar surgery, it is a reliable, secure, and safer option for administering extraoral mandibular nerve block. In the future, the use of this technique could extend to pain control during major procedures such as cleft lip and palate, orthognathic, tumour removal, and facial injuries too.

11. Cervicogenic headache and occipital neuralgia

INTRODUCTION

Cervicogenic headache (CEH) and occipital neuralgia (ON) are headaches originating in the occiput and that radiate to the vertex. Because of the intimate relationship between structures based in the occiput and those in the upper cervical region, there is significant overlap between the presentation of CEH and ON. Diagnosis starts with a headache history to assess for diagnostic criteria formulated by the International Headache Society. Physical examination evaluates range of motion of the neck and the presence of tender areas or pressure points.

METHODS

The literature for the diagnosis and treatment of CEH and ON was searched from 2015 through August 2022, retrieved, and summarized.

RESULTS

Conservative treatment includes pain education and self-care, analgesic medication, physical therapy (such as reducing secondary muscle tension and improving posture), the use of TENS (transcutaneous electrical nerve stimulation), or a combination of the aforementioned treatments. Injection at various anatomical locations with local anesthetic with or without corticosteroids can provide pain relief for a short period. Deep cervical plexus block can result in improved pain for less than 6 months. In both CEH and ON, an occipital nerve block can provide important diagnostic information and improve pain in some patients, with PRF providing greater long-term pain control. Radiofrequency ablation of the cervical facet joints can result in improvement for over 1 year. Occipital nerve stimulation (ONS) should be considered for the treatment of refractory ON.

CONCLUSION

The treatment of CEH preferentially consists of radiofrequency treatment of the facet joints, while for ON, pulsed radiofrequency of the occipital nerves is indicated. For refractory cases, ONS may be considered.

Occipital nerve stimulation: A detailed description of a surgical approach and a discussion on implantation techniques

OBJECTIVE

Occipital Nerve Stimulation (ONS) is increasingly used to treat a range of chronic, refractory headache conditions, most notably chronic cluster headache (CCH). Despite this, there is still no consensus on the optimal implantation technique. Clinical reports and reviews in the field have reported remarkably high complication rates of which several can be directly related to the surgical approach. We here describe a comprehensive and detailed surgical approach used at Aarhus University Hospital, Denmark, aiming to improve paresthesia coverage and minimize complications.

METHODS

The implantation procedure described here is performed with a sleep-awake anesthetic regimen in a lateral position using anatomical landmarks and perioperative testing based on patient feedback. A single lead is subcutaneously implanted from behind the ear and across the back of the head, and the implantable pulse generator (IPG) is placed below the right clavicle.

RESULTS

From March 2018 to June 2024, 45 CCH patients were implanted using this approach and followed up for a total of 86.3 patient years. A total of 22 adverse events (AEs) occurred in 17 patients, with nine AEs requiring revision surgery. Notably, no instances of lead migration, lead breakage, or muscle/neck stiffness were observed. Temporary occipital dysesthesia was the most frequent non-surgical AE, resolving spontaneously within weeks. The rate of serious adverse events (SAEs) was one per 9.6 patient years. Six patients had the ONS system explanted due to lack of efficacy.

CONCLUSIONS

The surgical approach described here in detail offers several advantages, with a favorable complication profile, satisfactory paresthesia coverage, and good perioperative patient comfort. Advances in the surgical technique are vital to both patients and healthcare providers, and we believe this approach is a valuable contribution toward improved patient outcomes and procedural efficiency.

Neurosurgery for mental conditions and pain: An historical perspective on the limits of biological determinism

Neurosurgical operations treat involuntary movement disorders (MvDs), spasticity, cranial neuralgias, cancer pain, and other selected disorders, and implantable neurostimulation or drug delivery devices relieve MvDs, epilepsy, cancer pain, and spasticity. In contrast, studies of surgery or device implantations to treat chronic noncancer pain or mental conditions have not shown consistent evidence of efficacy and safety in formal, randomized, controlled trials. The success of particular operations in a finite set of disorders remains at odds with disconfirming results in others. Despite expectations that surgery or device implants would benefit particular patients, the normalization of unproven procedures could jeopardize the perceived legitimacy of functional neurosurgery in general. An unacknowledged challenge in functional neurosurgery is the limitation of biological determinism, wherein network activity is presumed to exclusively or predominantly mediate nociception, affect, and behavior. That notion regards certain pain states and mental conditions as disorders or dysregulation of networks, which, by implication, make them amenable to surgery. Moreover, implantable devices can now detect and analyze neural activity for observation outside the body, described as the extrinsic or micro perspective. This fosters a belief that automated analyses of physiological and imaging data can unburden the treatment of selected mental conditions and pain states from psychological subjectivity and complexity and the inherent sematic ambiguity of self-reporting. That idea is appealing; however, it discounts all other influences. Attempts to sway public opinion and regulators to approve deep brain stimulation for unproven indications could, if successful, harm the public interest, making demands for regulatory approval beside the point.

Mechanism of Action of Temporary Peripheral Nerve Stimulation

PURPOSE OF REVIEW

Peripheral nerve stimulation (PNS) refers to the technique of utilizing electrical stimulation of peripheral nerves to inhibit the transmission of pain signals. PNS is used to treat chronic intractable pain and post-surgical or post-traumatic pain alongside a variety of other pain conditions, including headaches, facial pain, pelvic and urogenital pain, chest wall pain, residual limb or phantom limb pain, and back pain.

RECENT FINDINGS

More recently, PNS has been used temporarily for periods of time less than 60 days to treat acute post-surgical pain. Peripheral nerve stimulation is believed to be effective due to its effects on both central and peripheral pathways. Centrally, it is proposed that the electrical pulses of PNS inhibit alpha-delta and C fibers, which decreases pain signaling in the higher centers of the central nervous system. Peripherally, gate theory is applied as it is theorized that PNS downregulates inflammatory mediators, endorphins, and neurotransmitters associated with pain signaling to decrease the transmission of efferent nociception and reduce pain sensations.

Conservative Management of Occipital Neuralgia Supported by Physical Therapy: A Review of Available Research and Mechanistic Rationale to Guide Treatment

PURPOSE OF REVIEW

Conservative management is consistently recommended as a first line intervention for occipital neuralgia (ON); however, there is limited clinical research regarding conservative intervention for ON. This lack of research may lead to underutilization or unwarranted variability in conservative treatment. This article provides mechanism-based guidance for conservative management of ON as a component of a multimodal treatment approach, and discusses the role of the physical therapist in the care team. It also highlights opportunities for further research to refine conservative management of this condition.

RECENT FINDINGS

Published research on conservative interventions specific to ON is limited to very low-quality evidence for the use of TENS. The contemporary shift toward precision pain management emphasizing treatment based on a patient's constellation of clinical features-a phenotype-rather than solely a diagnosis provides more personalized and specifically targeted pain treatment. This paradigm can guide treatment in cases where diagnosis-specific research is lacking and can be used to inform conservative treatment in this case. Various conservative interventions have demonstrated efficacy in treating many of the symptoms and accepted etiologies of ON. Conservative interventions provided by a physical therapist including exercise, manual therapy, posture and biomechanical training, TENS, patient education, and desensitization have mechanistic justification to treat symptoms and causes of ON. Physical therapists have adequate time and skill to provide such progressive and iterative interventions and should be included in a multimodal treatment plan for ON. Further research is required to determine appropriate dosing, sequencing, and progression of conservative treatments.

Pathophysiology of Pain and Mechanisms of Neuromodulation: A Narrative Review (A Neuron Project)

Pain serves as a vital innate defense mechanism that can significantly impact an individual's quality of life. Understanding the physiological effects of pain well plays an important role in developing novel pain treatments. Nociceptor neurons play a key role in pain and inflammation. Interactions between nociceptors and the immune system occur both at the site of injury and within the central nervous system. Modulating chemical mediators and nociceptor activity offers promising new approaches to pain management. Essentially, the sensory nervous system is essential for modulating the body's protective response, making it critical to understand these interactions to discover new pain treatment strategies. New innovations in neuromodulation have led to alternatives to opioids individuals with chronic pain with consequent improvement in disease-based treatment and nerve targeting. New neural targets from cellular and structural perspectives have revolutionized the field of neuromodulation. This narrative review aims to elucidate the mechanisms of pain transmission and processing, examine the characteristics and properties of nociceptors, and explore how the immune system influences pain perception. It further provides an updated overview of the physiology of pain and neuromodulatory mechanisms essential for managing acute and chronic pain. We assess the current understanding of different pain types, focusing on key molecules involved in each type and their physiological effects. Additionally, we compare painful and painless neuropathies and discuss the neuroimmune interactions involved in pain manifestation.

Four Decades of Occipital Nerve Stimulation for Headache Disorders: A Systematic Review

PURPOSE OF REVIEW

Chronic headaches are a significant source of disability worldwide. Despite the development of conventional strategies, a subset of patients remain refractory and/or experience side effects following these treatments. Hence, occipital nerve stimulation (ONS) should be considered as an alternative strategy for intractable chronic headaches. This review aims to provide a comprehensive overview of the effectiveness, safety, mechanisms and practical application of ONS for the treatment of headache disorders.

RECENT FINDINGS

Overall response rate of ONS is 35.7-100%, 17-100%, and 63-100% in patients with cluster headache, chronic migraine and occipital neuralgia respectively. Regarding the long-term effectivity in all groups, 41.6-88.0% of patients remain responders after ≥ 18.3 months. The most frequently reported adverse events include lead migration/fracture (13%) and local pain (7.3%). Based on our results, ONS can be considered a safe and effective treatment for chronic intractable headache disorders. To support more widespread application of ONS, additional research with larger sample sizes should be conducted.

Neuromodulation treatments for migraine: a contemporary update

PURPOSE OF REVIEW

Neuromodulation approaches have been a part of a revolution in migraine therapies with multiple devices approved or in development. These devices vary in the nerve(s) being targeted, implantable versus noninvasive form factors as well as their effectiveness for acute pain reduction or migraine prevention. This review will summarize these recent advancements and approaches that are being developed which build upon prior work and improved technology that may help enhance the effectiveness as well as the patient experience.

RECENT FINDINGS

Both noninvasive and implantable devices primarily targeting cranial nerves have shown the ability to help alleviate migraine symptoms. Multiple prospective and retrospective studies have demonstrated clinically meaningful reductions in headache intensity with noninvasive approaches, while prevention of migraine demonstrates more modest effects. Implantable neuromodulation technologies focusing on occipital and supraorbital stimulation have shown promise in migraine/headache prevention in chronic migraine patients, but there is a need for improvements in technology to address key needs for surgical approaches.

SUMMARY

Electrical neuromodulation approaches in the treatment of migraine is undergoing a transformation towards improved outcomes with better technologies that may suit various patient needs on a more individualized basis.

Occipital nerve stimulation in pediatric patients with refractory occipital neuralgia

PURPOSE

Occipital neuralgia (ON) is a disabling problem within the pediatric population. Many of these patients fail medical therapies and continue to suffer without further surgical management. Occipital nerve stimulation (ONS) is used to treat ON in the adult population leading to a 72-89% reduction in pain; however, there are limited studies regarding its use in the pediatric population. In this study, we examined the outcomes of ONS in pediatric patients with medically refractory ON.

METHODS

We performed a chart review of pediatric patients at our institution who have undergone ONS for the same indications.

RESULTS

We identified 3 patients at our institution who underwent ONS trial and/or permanent implantation for ON. One patient had complete pain relief after the trial and declined permanent implantation. The other patient had fewer attacks compared to his pre-trial baseline and controlled them by adjusting his permanent implant stimulation settings. The last patient had near complete relief of her symptoms and no longer required any pain medication.

CONCLUSION

Our study highlights the paucity of studies evaluating the utility of ONS in the pediatric ON population. Limited data from both the literature and our institution's experience reveal that pediatric patients may benefit from trial and/or permanent implantation of ONS for medically refractory ON pain.

A Definition of Neuromodulation and Classification of Implantable Electrical Modulation for Chronic Pain

OBJECTIVES

Neuromodulation therapies use a variety of treatment modalities (eg, electrical stimulation) to treat chronic pain. These therapies have experienced rapid growth that has coincided with escalating confusion regarding the nomenclature surrounding these neuromodulation technologies. Furthermore, studies are often published without a complete description of the effective stimulation dose, making it impossible to replicate the findings. To improve clinical care and facilitate dissemination among the public, payors, research groups, and regulatory bodies, there is a clear need for a standardization of terms.

APPROACH

We formed an international group of authors comprising basic scientists, anesthesiologists, neurosurgeons, and engineers with expertise in neuromodulation. Because the field of neuromodulation is extensive, we chose to focus on creating a taxonomy and standardized definitions for implantable electrical modulation of chronic pain.

RESULTS

We first present a consensus definition of neuromodulation. We then describe a classification scheme based on the 1) intended use (the site of modulation and its indications) and 2) physical properties (waveforms and dose) of a neuromodulation therapy.

CONCLUSIONS

This framework will help guide future high-quality studies of implantable neuromodulatory treatments and improve reporting of their findings. Standardization with this classification scheme and clear definitions will help physicians, researchers, payors, and patients better understand the applications of implantable electrical modulation for pain and guide informed treatment decisions.

A surgical decision aid for occipital neuralgia with literature review and single center case series

BACKGROUND

Occipital neuralgia (ON) is a debilitating headache disorder. Due to the rarity of this disorder and lack of high-level evidence, a clear framework for choosing the optimal surgical approach for medically refractory ON incorporating shared decision making with patients does not exist.

METHODS

A literature review of studies reporting pain outcomes of patients who underwent surgical treatment for ON was performed, as well as a retrospective chart review of patients who underwent surgery for ON within our institution.

RESULTS

Thirty-two articles met the inclusion criteria. A majority of the articles were retrospective case series (22/32). The mean number of patients across the studies was 34 (standard deviation (SD) 39). Among the 13 studies that reported change in pain score on 10-point scales, a study of 20 patients who had undergone C2 and/or C3 ganglionectomies reported the greatest reduction in pain intensity after surgery. The studies evaluating percutaneous ablative methods including radiofrequency ablation and cryoablation showed the smallest reduction in pain scores overall. At our institution from 2014 to 2023, 11 patients received surgical treatment for ON with a mean follow-up of 187 days (SD 426).

CONCLUSION

Based on these results, the first decision aid for selecting a surgical approach to medically refractory ON is presented. The algorithm prioritizes nerve sparing followed by non-nerve sparing techniques with the incorporation of patient preference. Shared decision making is critical in the treatment of ON given the lack of clear scientific evidence regarding the superiority of a particular surgical method.

Peripheral Nervous System Pain Modulation

The percutaneous technique of electrode insertion in the vicinity of the greater occipital nerves to treat occipital neuralgia was first described in the 1990s by Weiner and Reed. This subsequently stimulated awareness of peripheral nerve stimulation (PNS). The more recent advent emergence of a minimally invasive percutaneous approach by way of using ultrasound has further increased the interest in PNS as a viable alternative to more invasive techniques. PNS has become more popular recently and is increasingly used to treat various pain conditions. Its foundation is fundamentally based on the gate control theory, although the precise mechanism underlying its analgesic effect is still indefinite. Studies have demonstrated the peripheral and central analgesic mechanisms of PNS by modulating the inflammatory pathways, the autonomic nervous system, the endogenous pain inhibition pathways, and the involvement of the cortical and subcortical areas. Peripheral nerve stimulation exhibits its neuromodulatory effect both peripherally and centrally. Further understanding of the modulation of PNS mechanisms can help guide stimulation approaches and parameters to optimize the use of PNS. his chapter aims to review the background and mechanisms of PNS modulation. PNS is becoming one of the most diverse therapies in neuromodulation due to rapid evolution and expansion. It is an attractive option for clinicians due to the simplicity and versatility of procedures that can be combined with other neuromodulation treatments or used alone. It has a distinct role in the modulation of functional conditions.

Neuromodulation for Craniofacial Pain and Headaches

Headaches and facial pain are highly prevalent diseases but are often difficult to treat. Though there have been significant advances in medical management, many continue to suffer from refractory pain. Neuromodulation has been gaining interest for its therapeutic purposes in many chronic pain conditions, including headaches and facial pain. There are many potential targets of neuromodulation for headache and facial pain, and some have more robust evidence in favor of their use than others. Despite the need for more high-quality research, the available evidence for the use of neuromodulation in treating headaches and facial pain is promising. Considering the suffering that afflicts patients with intractable headache, neuromodulation may be an appropriate tool to improve not only pain but also disability and quality of life.

Peripheral Nerve Stimulation for Pain Management: A Review

PURPOSE OF REVIEW

Peripheral nerve stimulation has seen a recent upsurge in utilization for various chronic pain conditions, specifically from a neuropathic etiology, where a single peripheral nerve can be pinpointed as a culprit for pain.

RECENT FINDINGS

There is conflicting evidence about the efficacy and long-term outcomes of peripheral nerve stimulation for chronic pain, with most studies being small sized. The focus of this article is to review available evidence for the utilization of peripheral nerve stimulation for chronic pain syndromes as well as upcoming evidence in the immediate postoperative realm. The indications for the use of PNS have expanded from neuropathic pain such as occipital neuralgia and post-amputation pain, to more widespread disease processes such as chronic low back pain. Percutaneous PNS delivered over a 60-day period may provide significant carry-over effects including pain relief, potentially avoiding the need for a permanently implanted system while enabling improved function in patients with chronic pain.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Occipital Nerve Stimulation for the Treatment of Patients With Medically Refractory Occipital Neuralgia: Update

BACKGROUND

The Guidelines Task Force conducted a systematic review of the relevant literature on occipital nerve stimulation (ONS) for occipital neuralgia (ON) to update the original 2015 guidelines to ensure timeliness and accuracy for clinical practice.

OBJECTIVE

To conduct a systematic review of the literature and update the evidence-based guidelines on ONS for ON.

METHODS

The Guidelines Task Force conducted another systematic review of the relevant literature, using the same search terms and strategies used to search PubMed and Embase for relevant literature. The updated search included studies published between 1966 and January 2023. The same inclusion/exclusion criteria as the original guideline were also applied. Abstracts were reviewed, and relevant full text articles were retrieved and graded. Of 307 articles, 18 were retrieved for full-text review and analysis. Recommendations were updated according to new evidence yielded by this update .

RESULTS

Nine studies were included in the original guideline, reporting the use of ONS as an effective treatment option for patients with medically refractory ON. An additional 6 studies were included in this update. All studies in the original guideline and this current update provide Class III evidence.

CONCLUSION

Based on the availability of new literature, the current article is a minor update only that does not result in modification of the prior recommendations: Clinicians may use ONS as a treatment option for patients with medically refractory ON.

Literature Review: Pericranial Nerve Blocks for Chronic Migraines

Purpose of Review

Headaches, especially migraines, are one of the most pervasive neurological disorders affecting up to 15.9% of the population. Current methods of migraine treatment include lifestyle changes, pharmacologic, and minimally invasive techniques such as peripheral nerve stimulation (PNS) and pericranial nerve blocks (PNB).

Recent Findings

PNBs are used to treat and prevent migraines and involves injection of local anesthetics with or without corticosteroids. PNBs include the greater occipital, supraorbital, supratrochlear, lesser occipital, auriculotemporal, sphenopalantine ganglion, and cervical root nerve blocks. Of the PNBs, the most extensively studied is the greater occipital nerve block (GONB) which has been shown to be an efficacious treatment for migraines, trigeminal neuralgia, hemi-crania continua, and post-lumbar puncture, post-concussive, cluster, and cervicogenic headaches but not medication overuse and chronic tension type headaches.

Summary

In this review, we aim to summarize the recent literature on PNBs and their efficacy in the treatment of migraines including a brief discussion of peripheral nerve stimulation.

Minimally Invasive Preganglionic C2 Root Section for Occipital Neuralgia: 2 Case Reports and Operative Video

BACKGROUND

Occipital neuralgia is a painful condition that is believed to occur from processes that affect the greater, lesser, or third occipital nerves. Diagnosis is often made with a combination of classical symptoms, tenderness over the occipital region, and response to occipital nerve blocks. Cervical computed tomography or MRI may be obtained in multiple positions to detect any impingement. Diagnosis can be made with MRI tractography. Nonsurgical treatments include local anesthetic and steroid injections, anticonvulsant medications, botulinum toxin injections, physical therapy, acupuncture, transcutaneous electrical stimulation, cryoneurolysis, and radiofrequency ablation. Surgical treatments include greater occipital nerve decompression, C2 root section, intradural dorsal root rhizotomy, C1-2 fusion, and occipital nerve stimulation. Although stimulation has been favored in the past decade, complications and maintenance of the devices have led us to return to C2 ganglionectomy.

OBJECTIVE

To report on the use of a minimally invasive technique for C2 ganglionectomy to treat occipital neuralgia.

METHODS

Review demographic, surgery, and outcome data of a minimally invasive C2 root ganglionectomy used to treat to 2 patients with occipital neuralgia.

RESULTS

We report on 2 patients with clinically stereotypical unilateral occipital neuralgia confirmed by greater occipital nerve block, but with no imaging correlate. Both were successfully managed by C2 ganglionectomy through an 18-mm tubular retractor and outpatient surgery. Accompanying text, still photographs, and video describe the technique in detail.

CONCLUSION

Minimally invasive C2 ganglionectomy can be used to successfully treat occipital neuralgia.

Mechanism of Action of Peripheral Nerve Stimulation for Chronic Pain: A Narrative Review

The use of stimulation of peripheral nerves to test or treat various medical disorders has been prevalent for a long time. Over the last few years, there has been growing evidence for the use of peripheral nerve stimulation (PNS) for treating a myriad of chronic pain conditions such as limb mononeuropathies, nerve entrapments, peripheral nerve injuries, phantom limb pain, complex regional pain syndrome, back pain, and even fibromyalgia. The ease of placement of a minimally invasive electrode via percutaneous approach in the close vicinity of the nerve and the ability to target various nerves have led to its widespread use and compliance. While most of the mechanism behind its role in neuromodulation is largely unknown, the gate control theory proposed by Melzack and Wall in the 1960s has been the mainstay for understanding its mechanism of action. In this review article, the authors performed a literature review to discuss the mechanism of action of PNS and discuss its safety and usefulness in treating chronic pain. The authors also discuss current PNS devices available in the market today.

Efficacy of Peripheral Nerve Stimulation with a High Frequency Electromagnetic Coupled (HF-EMC) Powered Implanted Receiver in Treating Different Pain Targets/Neuralgias

Introduction

Chronic pain is a significant global public health problem. Peripheral nerve stimulation (PNS) has been gaining popularity in recent years as it is effective, safe and less invasive than surgery for the treatment of chronic pain. The authors aimed to document and share a collection of patient-reported pain scores before and after implanting a percutaneous PNS lead/s with an external wireless generator at various target nerves.

Methods

The authors designed a retrospective study, reviewing electronic medical records. Statistical analysis was performed using SPSS 26; p-value ≤ 0.05 was considered significant.

Results

The mean baseline pain scores of 57 patients have reduced significantly after the procedure at different follow-up durations. Target nerves included genicular nerves, superior cluneal nerves, posterior tibial nerve ± sural nerve, middle cluneal nerves, radial and ulnar nerves and right common peroneal nerve. In the one-month follow-up group, mean pain score was reduced from 7.44 ± 1.48 pre-procedure to 1.6 ± 1.49, from 7.42 ± 1.5 pre-procedure to 1.6 ± 1.5 7.42 at 3 months, from 7.52 ± 1.5 to 1.72 ± 1.57 at 6 months, from 7.41 ± 1.53 to 1.7 ± 1.55 at 9 months, from 7.41 ± 1.58 to 1.76 ± 1.63 at 12 months, from 7.38 ± 1.59 to 1.69 ± 1.56 at 15 months and from 7.5 ± 1.7 to 1.45 ± 1.57 at 24 months (p ≤ 0.001). Patients also reported significant reduction in morphine milliequivalent, pre-procedure MME 47.75 ± 452.5 to 37.92 ± 43.51 at 6 months (p = 0.002, N = 57), pre-procedure MME 42.72 ± 43.19 to 30.38 ± 41.62 at 12 months (p = 0.003, N = 42), and pre-procedure MME 41.2 ± 46.12 to 21.19 ± 40.88 at 24 months (p ≤ 0.001, N = 27). The only complications occurred post procedure with 2 patients receiving an explant and 1 patient receiving a lead migration.

Conclusion

PNS has been shown to be safe and effective in treating chronic pain at different sites with sustained pain relief for up to 24 months. This study is unique in providing long-term follow-up data.

Long term outcomes of occipital nerve stimulation

Background

Occipital nerve stimulation (ONS) has been investigated as a potential treatment for disabling headaches and has shown promise for disorders such as chronic migraine and cluster headache. Long term outcomes stratified by headache subtype have had limited exploration, and literature on outcomes of this neuromodulatory intervention spanning 2 or more years is scarce.

Measures

We performed a narrative review on long term outcomes with ONS for treatment of headache disorders. We surveyed the available literature for studies that have outcomes for 24 months or greater to see if there is a habituation in response over time. Review of the literature revealed evidence in treatment of occipital neuralgia, chronic migraine, cluster headache, cervicogenic headache, short lasting unilateral neuralgiform headache attacks (SUNHA) and paroxysmal hemicrania. While the term "response" varied per individual study, a total of 17 studies showed outcomes in ONS with long term sustained responses (as defined per this review) in the majority of patients with specific headache types 177/311 (56%). Only 7 studies in total (3 cluster, 1 occipital neuralgia, 1 cervicogenic headache, 1 SUNHA, 1 paroxysmal hemicrania) provided both short-term and long-term responses up to 24 months to ONS. In cluster headache, the majority of patients (64%) were long term responders (as defined per this review) and only a minority of patients 12/62 (19%) had loss of efficacy (e.g., habituation). There was a high number 313/439 (71%) of adverse events per total number of patients in the studies including lead migration, requirements of revision surgery, allergy to surgical materials, infection and intolerable paresthesias.

Conclusions

With the evidence available, the response to ONS was sustained in the majority of patients with cluster headache with low rates of loss of efficacy in this patient population. There was a high percent of adverse events per number of patients in long term follow-up and likely related to the off-label use of leads typically used for spinal cord stimulation. Further longitudinal assessments of outcomes in occipital nerve stimulation with devices labelled for use in peripheral nerve stimulation are needed to evaluate the extent of habituation to treatment in headache.

Peripheral Nerve Stimulation in Painful Conditions of the Upper Extremity-An Overview

Our objective is to present a brief history of the evolution of peripheral nerve stimulation, the current understanding of peripheral nerve stimulation mechanisms in chronic pain, peripheral nerve stimulation applications in upper extremity chronic pain conditions, and complications of peripheral nerve stimulation. The evolution of peripheral nerve stimulation from the early ages to the current status has been facilitated by discoveries in neurobehavioral mechanisms of pain, advances in technology and percutaneous lead development, and the availability of high-quality portable ultrasound units. Peripheral nerve stimulation application in managing upper extremity pain of amputated limbs, post-stroke shoulder pain, complex regional pain syndrome (CRPS), and median, ulnar, and radial neuropathies are discussed. Finally, we describe complications of peripheral nerve stimulation. The availability of ultrasound-guided peripheral nerve stimulation techniques and superior peripheral nerve stimulation technology have opened up new and minimally invasive treatment options for chronic intractable neuropathic pain of the upper extremity. Additionally, the ability to place peripheral nerve stimulation leads percutaneously without open peripheral nerve surgery expands the pool of implanting physicians, while simultaneously decreasing the risks and complications that are associated with open surgery.

Implantable Peripheral Nerve Stimulation for Peripheral Neuropathic Pain: A Systematic Review of Prospective Studies

Peripheral nerve stimulation (PNS) has been utilized for over 50 years with accumulating evidence of efficacy in a variety of chronic pain conditions. The level and strength of evidence supporting the use of PNS for peripheral neuropathic pain remains unclear. The purpose of this review is to synthesize data from prospective studies on the efficacy of PNS for neuropathic pain as it pertains to pain intensity, neurological deficits/neuropathy (e.g., weakness, sensory deficits, gait/balance), and other secondary outcomes (quality of life, satisfaction, emotional functioning, and adverse events). In compliance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, this review identified articles from MEDLINE(R), EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus. Overall, per the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria, pooled results demonstrate very low quality or low quality of evidence supporting modest to substantial improvement in pain and neurological function after PNS implantation for treatment of peripheral neuropathic pain. PNS for phantom limb pain was the only indication that had moderate level evidence. Future prospective and well-powered studies are warranted to assess the efficacy of PNS for peripheral neuropathic pain.

Evidence-Based Clinical Guidelines from the American Society of Pain and Neuroscience for the Use of Implantable Peripheral Nerve Stimulation in the Treatment of Chronic Pain

The objective of this peripheral nerve stimulation consensus guideline is to add to the current family of consensus practice guidelines and incorporate a systematic review process. The published literature was searched from relevant electronic databases, including PubMed, Scopus, Cochrane Central Register of Controlled Trials, and Web of Science from database inception to March 29, 2021. Inclusion criteria encompassed studies that described peripheral nerve stimulation in patients in terms of clinical outcomes for various pain conditions, physiological mechanism of action, surgical technique, technique of placement, and adverse events. Twenty randomized controlled trials and 33 prospective observational studies were included in the systematic review process. There is Level I evidence supporting the efficacy of PNS for treatment of chronic migraine headaches via occipital nerve stimulation; chronic hemiplegic shoulder pain via stimulation of nerves innervating the trapezius, supraspinatus, and deltoid muscles; failed back surgery syndrome via subcutaneous peripheral field stimulation; and lower extremity neuropathic and lower extremity post-amputation pain. Evidence from current Level I studies combined with newer technologies facilitating less invasive and easier electrode placement make peripheral nerve stimulation an attractive alternative for managing patients with complex pain disorders. Peripheral nerve stimulation should be used judiciously as an adjunct for chronic and acute postoperative pain following adequate patient screening and positive diagnostic nerve block or stimulation trial.

Cancer Pain Management-New Therapies

PURPOSE OF REVIEW

Despite the rapid advance in anti-cancer treatment in recent years, the treatment to cancer-related pain remains largely unchanged. One systemic review has shown that approximately 32% of patient with cancer-related pain were undertreated. While in patients responding to strong opioids, long-term use of opioids will lead to many undesired side effects such as constipation, tolerance, and addiction. The goals of this review are to re visit the current algorism of cancer pain management and bring attention to the emerging interventional pain management techniques.

RECENT FINDINGS

Peripheral nerve stimulation (PNS) has been successfully used to treat certain types of chronic non-cancer pain with long-term analgesic effect. PNS has also brought some promising results in treating localized cancer-related pain in a pilot study. More studies are needed to advance the novel and safe treatment of cancer-related pain. Incorporating interventional techniques such as PNS properly can optimize the current treatment strategy and improve outcomes.

Peripheral Nerve Stimulation: The Evolution in Pain Medicine

Electrical stimulation of peripheral nerves has been utilized for a variety of indications for over five decades [...].

Subcutaneous Peripheral Nerve Stimulation for Treatment of Acute/Subacute Herpes Zoster-related Trigeminal Neuralgia: A Retrospective Research

OBJECTIVES

The purpose of this study was to observe the effect of subcutaneous stimulation of the peripheral nerve on acute or subacute zoster occurring in trigeminal nerve branches, and to evaluate the preventive effect of prior temporary implant of a peripheral stimulation electrode in the acute or subacute phase of herpes zoster (HZ) (from 30 to 90 d after zoster onset) before postherpetic neuralgia (PHN) presents.

METHODS AND MATERIALS

A total of 26 patients' medical records were analyzed. All of patients had received temporary subcutaneous peripheral nerve stimulation (PNS). The clinical efficacy of treatment was evaluated on a visual analog scale (VAS), and dosages of pain medication were recorded before and at 1 to 6 months after the temporary stimulation. The rate of PHN was reevaluated at a 6 months follow-up.

RESULTS

There was a significant decrease in VAS values after PNS. Medication doses decreased significantly after TPNS. The rate of clinically meaningful PHN (VAS >3) dropped below 4%.

DISCUSSION

This study revealed that PNS is an effective treatment for trigeminal herpetic neuralgia following acute or subacute HZ. As a extend neuromodulation method, subcutaneous peripheral nerve-field stimulation might be a useful option to reduce the progression of neuropathic changes caused by persistent transmission of pain signals in the trigeminal nerve branches after the acute or subacute phase of HZ.

A narrative review and future considerations of spinal cord stimulation, dorsal root ganglion stimulation and peripheral nerve stimulation

PURPOSE OF REVIEW

In recent years, neuromodulation has experienced a renaissance. Novel waveforms and anatomic targets show potential improvements in therapy that may signify substantial benefits. New innovations in peripheral nerve stimulation and dorsal root ganglion stimulation have shown prospective evidence and sustainability of results. Sub-perception physiologic bursting, high-frequency stimulation and feedback loop mechanisms provide significant benefits over traditional tonic spinal cords stimulation (SCS) in peer reviewed investigations. We reviewed the themes associated with novel technology in the context of historical stalwart publications.

RECENT FINDINGS

New innovations have led to better nerve targeting, improvements in disease-based treatment, and opioid alternatives for those in chronic pain. In addition, new neural targets from both structural and cellular perspectives have changed the field of Neurostimulation.

SUMMARY

For many years, tonic SCS was representative of neuromodulation, but as this review examines, the progression of the field in the past decade has reshaped patient options.

Peripheral Nerve Stimulation for Chronic Pain: A Systematic Review of Effectiveness and Safety

Peripheral nerve stimulation (PNS) was the first application of neuromodulation. Widespread application of PNS was limited by technical concerns. Recent advances now allow the percutaneous placement of leads with ultrasound or fluoroscopic guidance, while the transcutaneous powering of these leads removes the need for leads to cross major joints. This systematic review was written to assess the current status of high-quality evidence supporting the use of PNS for pain conditions treated by interventional pain physicians. The available literature on PNS, limited to conditions treated by interventional pain physicians, was reviewed and the quality assessed. Literature from 1966 to June 2021 was reviewed. The outcome measures were pain relief and functional improvement. One hundred and two studies were identified. Five randomized controlled trials (RCT) and four observational studies, all case series, met the inclusion criteria. One RCT was of high quality and four were of moderate quality; all four case series were of moderate quality. Three of the RCTs and all four case series evaluated peripheral nerve neuropathic pain. Based upon these studies, there is level II evidence supporting the use of PNS to treat refractory peripheral nerve injury. One moderate-quality RCT evaluated tibial nerve stimulation for pelvic pain, providing level III evidence for this indication. One moderate-quality RCT evaluated surgically placed cylindrical leads for cluster headaches, providing level III evidence for this indication. The evidence suggests that approximately two-thirds of patients with peripheral neuropathic pain will have at least 50% sustained pain relief. Adverse events from PNS are generally minor. A major advantage of PNS over spinal cord stimulation is the absence of any risk of central cord injury. The study was limited by the paucity of literature for some indications. No studies dealt with joint-related osteoarthritic pain.

Peripheral Nerve Stimulation for Treatment of Headaches: An Evidence-Based Review

Headaches are one of the most common medical complaints worldwide, and treatment is often made difficult because of misclassification. Peripheral nerve stimulation has emerged as a novel treatment for the treatment of intractable headaches in recent years. While high-quality evidence does exist regarding its use, efficacy is generally limited to specific nerves and headache types. While much research remains to bring this technology to the mainstream, clinicians are increasingly able to provide safe yet efficacious pain control.

Inflammation neuroscience: neuro-immune crosstalk and interfaces

Inflammation is a key process in antimicrobial defence and tissue repair, and failure to properly regulate inflammation can result in tissue damage and death. Neural circuits play important roles throughout the course of an inflammatory response, and the neurophysiological and molecular mechanisms are only partly understood. Here, we review key evidence for the neural regulation of inflammation and discuss emerging technologies to further map and harness this neurophysiology, a cornerstone in the rapidly evolving field of inflammation neuroscience.

Temperature-Mediated Nerve Blocks in the Treatment of Pain

PURPOSE OF REVIEW

Analgesic hot and cold temperatures have been used for both conservative and ablative therapies for millennia. There are well-known locoregional neurovascular changes associated with the application of heat or ice in the literature and in practice. The oscillation between heat and cold has recently been identified as a synergistic mechanism of action with early translational results in humans.

RECENT FINDINGS

Recent mechanistic work in the feline model has demonstrated that a reliable, reversible nerve block can be achieved within a temperature range that is non-destructive (15-45°C). The underlying mechanism is a newly described hysteresis in the responsiveness of peripheral nerves to alternating thermal stimuli resulting in nerve blockade. Recently presented feasibility data reports positive results in subjects with occipital pain and peripheral scar pain in terms of pain and associated symptom improvement. Temperature-mediated changes in pain and sensation have been observed for hot and cold applications at a variety of temperatures. Recent insights into the synergy between preheating followed by cooling resulting in peripheral nerve fiber block has potential in a variety of conditions in which peripheral nerve etiology is noted. Recent findings in chronic headache patients report decreased pain and symptom improvement. Further studies are ongoing to understand the indications for this novel therapy.

Percutaneous Full-Endoscopic C2 Ganglionectomy for the Treatment of Intractable Occipital Neuralgia: Technical Note

BACKGROUND

The C-2 dorsal root ganglionectomy procedure can provide effective treatment for intractable occipital neuralgia (ON). However, the traditional microsurgery of C2 ganglionectomy needs a wide incision and significant paraspinous muscle dissection for adequate visualization. The indications of endoscopic spine surgery are ever expanding, with the development of endoscopic armamentaria and technological innovations.

OBJECTIVE

To validate the feasibility of the approach and describe several operative nuances based on the authors' experience. In this paper, the authors describe a patient with intractable ON who was successfully treated with a percutaneous full-endoscopic C2 ganglionectomy.

METHODS

We describe the case of an 83-yr-old female with a 2-yr history of left ON who did not respond to a series of treatments, including physical therapy, drug therapy, injection therapy, and radiofrequency therapy. After careful examination, we performed a percutaneous, full-endoscopic left C2 ganglionectomy.

RESULTS

The patient was successfully treated with a percutaneous full-endoscopic ganglionectomy. Afterwards, her intractable and constant pain was relieved. There was no cerebrospinal fluid leakage, incision infection, neck deformity, or other complications.

CONCLUSION

C2 ganglionectomy can be accomplished successfully using a full-endoscopic uniportal surgical technique under continuous irrigation, which has the advantages of excellent illumination and visualization, reduced surgery-related trauma, and reduced bleeding.

Occipital Neuralgia: Advances in the Operative Management

Background

Occipital neuralgia (ON) is a primary headache disorder characterized by sharp, shooting, or electric shock-like pain in the distribution of the greater, lesser, or third occipital nerves.

Aim

To review the existing literature on the management of ON and to describe our technique of an endoscopic-assisted approach to decompress the GON proximally in areas of fibrous and muscular compression, as well as distally by thorough decompression of the occipital artery from the nerve.

Methods

Relevant literature on the medical and surgical management of ON was reviewed. Literature on the anatomical relationships of occipital nerves and their clinical relevance were also reviewed.

Results

While initial treatment of ON is conservative, peripheral nerve blocks and many surgical management approaches are available for patients with pain refractory to the medical treatment. These include greater occipital nerve blocks, occipital nerve stimulation, Botulinum toxin injections locally, pulsed radiofrequency ablation, cryoneuroablation, C-2 ganglionectomy, and endoscopic-assisted ON decompression.

Conclusion

Patients of ON refractory to medical management can be benefitted by surgical approaches and occipital nerve blocks. Endoscopic-assisted ON decompression provides one such approach for the patients with vascular, fibrous or muscular compressions of occipital nerves resulting in intractable ON.

Occipital Neuralgia and Its Management: An Overview

Background

Greater and lesser occipital neuralgias are primary neuralgias that are relatively uncommon, where the pain is felt in the distribution of these nerves.

Objective

This review paper was intended to describe the features and management of occipital neuralgia in the context of a challenging case.

Material and Methods

We looked at succinct literature from the past 30 years. We compared the features of our challenging case given in the current literature. In addition, an overview of the current literature is provided.

Results

The case, although proved to be a diagnostic challenge, we were able to reach a conclusion and render the patient almost complete pain relief by conservative management modalities. It proved to be a rare presentation of occipital neuralgia with unusual pain distribution, and we are able to describe a literature-based explanation for this entity to be a diagnostic and management challenge.

Conclusion

Primary headaches, i'n general, are a group of headache disorders that require exquisite diagnostic skills. The clinical history is a key factor when making an accurate diagnosis, and to establish an appropriate management plan.

Long-Term Experience with Occipital and Supraorbital Nerve Stimulation for the Various Headache Disorders-A Retrospective Institutional Case Series of 96 Patients

OBJECTIVE

We have provided long-term data on clinically meaningful pain alleviation for drug-refractory headache disorders using occipital (ONS) and supraorbital nerve stimulation (SONS).

METHODS

We performed a retrospective review of 96 patients with migraine, cervicogenic headache, cluster headache, neuropathic pain of the scalp, tension-type headache, and new daily persistent headache who had undergone ONS (61.5%), SONS (11.5%), or combined ONS plus SONS (27.1%) trial implantation and definitive implantation from 2007 to 2017. Changes in pain perception over time were monitored using the visual analog scale (VAS) for pain.

RESULTS

The cohort consisted of 60.4% women and 39.6% men, with a mean age of 46.9 ± 11.5 years and pain duration of 14 ± 14.1 years. Of the 96 patients, 65 (67.7%) were treatment responders to a trial (≥30% amelioration in the average or maximum VAS score for pain and/or number of headache days) that had lasted 22.5 ± 8.8 days. The reduction in their average VAS score for pain was to 37% ± 24.4% of baseline compared with 99.1% ± 24.1% of baseline for those without a response (P < 0.01). Of the 56 patients who had undergone implantation and had long-term follow-up data available for ≤10 years, 32 (57.1%) reported a ≥50% reduction in their average VAS score for pain. Four patients (6.5%) had requested hardware explantation. Stage II complications included 1 infection (1.6%) and 6 electrode dislocations (9.7%). The study limitations included the retrospective nature, lack of controls receiving placebo intervention, and randomization.

CONCLUSIONS

After careful patient selection according to a positive response to a trial of ONS and/or SONS, clinically meaningful long-term benefit was achieved in 57.1% of our patients with various chronic headache conditions.

Is Noninvasive Vagus Nerve Stimulation a Safe and Effective Alternative to Medication for Acute Migraine Control?

BACKGROUND

Noninvasive neuromodulation devices have been used for a variety of headache disorders, including cluster and migraine, since recently being cleared by the Federal Drug Administration. Although these devices have been touted as low-risk options for improved headache control, the data behind actual efficacy endpoints remain unclear.

OBJECTIVE

To critically assess current evidence regarding the efficacy of the noninvasive vagus nerve stimulator (nVNS) device for acute migraine management.

METHODS

The objective was addressed through the development of a structured critically appraised topic. This included a clinical scenario with a clinical question, literature search strategy, critical appraisal, results, evidence summary, commentary, and bottom line conclusions.Participants included consultant and resident neurologists, a medical librarian, clinical epidemiologists, and a content expert in the field of headache.

RESULTS

A randomized, double-blind, sham-controlled clinical trial was selected for critical appraisal. In this trial, the primary endpoint (pain freedom at 120 min after use of nVNS for first acute migraine attack) was not met when compared with sham device (30.4% for nVNS vs. 19.7% for sham; P=0.067). However, there were statistically significant differences found for various secondary endpoints favoring nVNS, such as pain freedom rates at 30 and 60 minutes, pain relief at 120 minutes, and mean percentage pain score reduction rates at 60 and 120 minutes.

CONCLUSIONS

When comparing nVNS with sham, no statistically significant differences were found with regards to the primary endpoint of pain freedom at 120 minutes, although differences were found with various secondary endpoints and post hoc analysis. nVNS is likely a safe alternative to medications.

Peripherally Induced Reconditioning of the Central Nervous System: A Proposed Mechanistic Theory for Sustained Relief of Chronic Pain with Percutaneous Peripheral Nerve Stimulation

Peripheral nerve stimulation (PNS) is an effective tool for the treatment of chronic pain, although its efficacy and utilization have previously been significantly limited by technology. In recent years, purpose-built percutaneous PNS devices have been developed to overcome the limitations of conventional permanently implanted neurostimulation devices. Recent clinical evidence suggests clinically significant and sustained reductions in pain can persist well beyond the PNS treatment period, outcomes that have not previously been observed with conventional permanently implanted neurostimulation devices. This narrative review summarizes mechanistic processes that contribute to chronic pain, and the potential mechanisms by which selective large diameter afferent fiber activation may reverse these changes to induce a prolonged reduction in pain. The interplay of these mechanisms, supported by data in chronic pain states that have been effectively treated with percutaneous PNS, will also be discussed in support of a new theory of pain management in neuromodulation: Peripherally Induced Reconditioning of the Central Nervous System (CNS).

Effect of Occipital Nerve Stimulation (ONS) on the Orbicularis Oculi Reflex Triggered by a Standardized Air Flow in Patients with Chronic Migraine-A Prospective, Randomized, Interventional Study

Introduction

Occipital nerve stimulation (ONS) is a specific form of peripheral neuromodulation used in the treatment of chronic pain disorders. A particular field of application is in the therapy of treatment-refractory headaches, especially of chronic migraine. The precise mode of action is unknown. It is presumed that central and peripheral sensitization are reduced in patients with chronic headache. The aim of this study was to examine the effect of ONS on pain-modulatory mechanisms in the trigeminocervical area in patients with chronic migraine.

Methods

In a balanced repeated measurements design in eight patients with chronic migraine with and without active ONS, we analyzed which effects ONS had on the orbicularis oculi reflex dynamically elicited by corneal air flow.

Results

The orbicularis oculi reflex in active ONS (7.38 ± 20.14 eyelid closures/minute) compared to inactive ONS (18.73 ± 14.30 eyelid closures/minute) is significantly reduced (p = 0.021).

Conclusions

The results show that under active ONS compared to inactive ONS in patients with chronic migraine, the orbicularis oculi reflex, dynamically triggered by a standardized air flow, is significantly reduced. This suggests that ONS is able to directly counteract the trigeminally mediated central sensitization in chronic migraine and protectively reduce the effects of aversive peripheral stimulation.

Occipital Nerve Stimulation for Pain Modulation in Drug-Resistant Chronic Cluster Headache

Occipital nerve stimulation (ONS) is a surgical treatment proposed for drug-resistant chronic cluster headache (drCCH). Long-term series assessing its efficacy are scarce. We designed a retrospective observational study with consecutive sampling, evaluating the follow-up of 17 drCCH patients who underwent ONS. Our main endpoint was the reduction the rate of attacks per week. We also evaluated the pain intensity through the Visual Analogue Scale (VAS), patient overall perceived improvement and decrease in oral medication intake. After a median follow-up of 6.0 years (4.5–9.0), patients decreased from a median of 30 weekly attacks to 22.5 (5.6–37.5, p = 0.012), 7.5 at 1 year (p = 0.006) and 15.0 at the end of follow-up (p = 0.041). The VAS decreased from a median of 10.0 to 8.0 (p = 0.011) at three months, to 7.0 (p = 0.008) at twelve months and 7.0 (p = 0.003) at the end of the follow-up. A total of 23.5% had an overall perceived improvement of ≥70% at 3 months, 41.2% at 1 year and 27.8% at the end of follow-up. Reducing prophylactic oral medication was possible in 76.5% and it was stopped in 17.7%. Triptan use decreased in all the responder patients and 17.7% stopped its intake. A total of 41.2% presented mild adverse events. In conclusion, our long-term experience suggests that ONS could be an interesting option for drCCH-selected patients, as it is a beneficial and minimally invasive procedure with no serious adverse events.

Updated management of occipital nerve stimulator lead migration: case report of a technical challenge

Electrode migration is a challenge, even with adequate anchoring techniques, due to the high mechanical stress on components of occipital nerve stimulation (ONS) for headache disorders. When a lead displacement of an ONS implant is diagnosed, there are currently different approaches described for its management. Nevertheless current neuromodulation devices are designed like a continuum of components without any intermediate connector, and if a lead displacement is diagnosed, the solution is the complete removal of the electrode from its placement, and its repositioning through an ex-novo procedure. The described technique can allow ONS leads to be revised while minimizing the need to reopen incisions over the IPG, thus improving patients' intraoperative and postoperative discomfort, shortening surgical time and medical costs, reasonably reducing the incidence of infective postoperative complications.

Noninvasive Neuromodulation in Migraine

PURPOSE OF REVIEW

The past two decades has seen an influx of noninvasive neuromodulation devices aimed at treatment of various primary headache disorders, including cluster headache and migraine. This narrative review is to summarize the current options in noninvasive neuromodulation in migraine.

RECENT FINDINGS

A variety of noninvasive neuromodulation devices have been FDA cleared and marketed for use in migraine, including single-pulse transcranial magnetic stimulation (sTMS), noninvasive vagal nerve stimulators (nVNS), and external trigeminal nerve stimulators (eTNS). Newer devices include peripheral electrical stimulation devices (PES), caloric stimulation, and others. Each has varying levels of evidence supporting its use in migraine, tolerability profiles, and access issues. Noninvasive neuromodulation devices can be beneficial when used in patients with migraine, with minimal side effects. As more devices are developed, approved, and marketed in the future, rigorous research on efficacy and safety remain a top priority.

Peripheral nerve stimulation registry for intractable migraine headache (RELIEF): a real-life perspective on the utility of occipital nerve stimulation for chronic migraine

BACKGROUND

Migraine is common and ranked as the first cause of disability in people under fifty. Despite significant advances in its pharmacological treatment, it often remains intractable. Neuromodulation is one option considered in the management of those patients.

OBJECTIVE

To assess the safety and efficacy of neuromodulation in the treatment of intractable chronic migraine using the Abbott occipital nerve stimulator.

METHODS

Recruitment took place in 18 centres in 6 countries. Patients over the age of 18 who had failed three or more preventative drugs, had at least moderate disability based on MIDAS or HIT-6 score and were implanted with an Abbott neurostimulator were included in the study. Patients were followed up for a maximum of 24 months. Data were collected on adverse events, headache relief, headache days, quality of life, migraine disability, satisfaction and quality of life.

RESULTS

One hundred twelve patients were included, 79 female and 33 male, with 45 patients reaching the maximum follow-up of 24 months. At 3 months, 33.7% were satisfied or very satisfied with the procedure with 43.0% reporting improved or greatly improved quality of life. 67.5% indicated that they would undergo the procedure again with satisfaction peaking at 9 months when 49.3% were satisfied or very satisfied with the procedure. At 24 months, 46.7% of available patients were satisfied or very satisfied with the procedure-18% of enrolled patients. The adverse events were however frequent with incidences of 37%, 47% and 31% respectively for hardware-, biological and stimulation-related side effects.

CONCLUSION

Neuromodulation can be beneficial for selected patients with intractable chronic migraine although frequent complications have been consistently reported across studies. Further research focusing on development of better hardware and technique optimisation and in particular reliable randomised trials with significantly longer follow-ups are warranted in this field.

Changes in peripheral and central sensitization in patients undergoing occipital nerve stimulation

Introduction

Central sensitization and impaired conditioned pain modulation (CPM) response have been reported to contribute to migraine progression. Migraine patients can present with allodynia possibly attributed to increased sensitivity of peripheral ends of nociceptors with both peripheral and central sensitization. Occipital nerve stimulation (ONS) works by stimulating the distal branches of C1, C2 and C3 possibly altering the nociceptive traffic to the trigemino-cervical complex, brainstem and supranuclear connections.

Aims

This observational study explores peripheral and central sensitization in patients undergoing percutaneous ONS.

Methods

Following local regulatory approval, 13 patients undergoing ONS with dual Octrode 90 cm leads and rechargeable implantable pulse generator (IPG) (St Jude) were recruited to have quantitative sensory testing (QST) pre- and post-procedure 2 weeks, 1, 3, 6 and 12 months.

Results

Patients with intractable migraine demonstrated impaired CPM (mean baseline pressure pain thresholds (PPTs): 61.98 kPa vs 48.01 kPa cuff inflated) prior to ONS, reverting to an efficient CPM response within 2 weeks following ONS implant (68.9 kPa vs 104.5 kPa cuff inflated) and continuing positively over the next 12 months. In contrast, no statistical difference was observed in PPTs.

Conclusion

This is the first reported observation highlighting the effects on central sensitization following ONS. A consistent and sustained improvement in CPM was observed in contrast to PPT's where there was no difference. Normalisation of the CPM response following ONS indicates that the treatment may reduce central sensitization in the migraine population.