Virtual Reality in Acute and Chronic Pain Medicine: An Updated Review.

PURPOSE OF REVIEW: This review critically analyzes the recent literature on virtual reality's (VR) use in acute and chronic pain management, offering insights into its efficacy, applications, and limitations. RECENT FINDINGS: Recent studies, including meta-analyses and randomized controlled trials, have demonstrated VR's effectiveness in reducing pain intensity in various acute pain scenarios, such as procedural/acute pain and in chronic pain conditions. The role of factors such as immersion and presence in enhancing VR's efficacy has been emphasized. Further benefits have been identified in the use of VR for assessment as well as symptom gathering through conversational avatars. However, studies are limited, and strong conclusions will require further investigation. VR is emerging as a promising non-pharmacological intervention in pain management for acute and chronic pain. However, its long-term efficacy, particularly in chronic pain management, remains an area requiring further research. Key findings highlight that VR programs vary in efficacy depending on the specificity of the origin of pain.

A brief review of complex regional pain syndrome and current management.

Complex regional pain syndrome (CRPS) is a debilitating chronic pain condition that, although exceedingly rare, carries a significant burden for the affected patient population. The complex and ambiguous pathophysiology of this condition further complicates clinical management and therapeutic interventions. Furthermore, being a diagnosis of exclusion requires a diligent workup to ensure an accurate diagnosis and subsequent targeted management. The development of the Budapest diagnostic criteria helped to consolidate existing definitions of CRPS but extensive work remains in identifying the underlying pathways. Currently, two distinct types are identified by the presence (CRPS type 1) or absence (CRPS type 2) of neuronal injury. Current management directed at this disease is broad and growing, ranging from non-invasive modalities such as physical and psychological therapy to more invasive techniques such as dorsal root ganglion stimulation and potentially amputation. Ideal therapeutic interventions are multimodal in nature to address the likely multifactorial pathological development of CRPS. Regardless, a significant need remains for continued studies to elucidate the pathways involved in developing CRPS as well as more robust clinical trials for various treatment modalities.

Complex regional pain syndrome (CRPS) is a debilitating and complex condition that places a significant physical, psychological and emotional burden upon afflicted patients necessitating multi-modal approaches to treatment.The development of the Budapest criteria provided a robust and well-tested set of diagnostic criteria to aid clinicians in the diagnosis of CRPS.The pathophysiology of CRPS has been challenging to elucidate with numerous proposed mechanisms, altogether suggesting a multi-factorial process is involved in the development of this condition.Non-invasive treatments for CRPS are essential in addressing the physical limitations this disease can cause as well as addressing the significant psychological burden that involves increased incidence of depression and suicidal ideation.Invasive treatments offer promising results, especially when considering dorsal root ganglion stimulation; however, the need for more robust clinical trials remains, especially when considering a small portion of patients who have refractory CRPS resort to amputation to control their pain symptoms.

Mechanisms of Action of Dorsal Root Ganglion Stimulation.

The dorsal root ganglion (DRG) serves as a pivotal site for managing chronic pain through dorsal root ganglion stimulation (DRG-S). In recent years, the DRG-S has emerged as an attractive modality in the armamentarium of neuromodulation therapy due to its accessibility and efficacy in alleviating chronic pain refractory to conventional treatments. Despite its therapeutic advantages, the precise mechanisms underlying DRG-S-induced analgesia remain elusive, attributed in part to the diverse sensory neuron population within the DRG and its modulation of both peripheral and central sensory processing pathways. Emerging evidence suggests that DRG-S may alleviate pain by several mechanisms, including the reduction of nociceptive signals at the T-junction of sensory neurons, modulation of pain gating pathways within the dorsal horn, and regulation of neuronal excitability within the DRG itself. However, elucidating the full extent of DRG-S mechanisms necessitates further exploration, particularly regarding its supraspinal effects and its interactions with cognitive and affective networks. Understanding these mechanisms is crucial for optimizing neurostimulation technologies and improving clinical outcomes of DRG-S for chronic pain management. This review provides a comprehensive overview of the DRG anatomy, mechanisms of action of the DRG-S, and its significance in neuromodulation therapy for chronic pain.

Spinal Cord Stimulation Waveforms for the Treatment of Chronic Pain.

PURPOSE OF REVIEW: Since the advent of spinal cord stimulation (SCS), advances in technology have allowed for improvement and treatment of various conditions, especially chronic pain. Additionally, as the system has developed, the ability to provide different stimulation waveforms for patients to treat different conditions has improved. The purpose and objective of the paper is to discuss basics of waveforms and present the most up-to-date literature and research studies on the different types of waveforms that currently exist. During our literature search, we came across over sixty articles that discuss the various waveforms we intend to evaluate. RECENT FINDINGS: There are several publications on several waveforms used in clinical practice, but to our knowledge, this is the only educational document teaching on waveforms which provides essential knowledge. There is a gap of knowledge related to understanding wave forms and how they work.

Chronic Abdominal Discomfort Syndrome (CADS): Defining and Discussing a Novel Diagnosis.

In this article, we propose a new diagnostic paradigm known as Chronic Abdominal Discomfort Syndrome (CADS). Patient's presentation centers around chronic abdominal pain not explained by acute pathology with or without accompanying dyspepsia, bloating, nausea and vomiting among other symptoms. The pathophysiology is noted to be neurogenic, possibly stemming from visceral sympathetic nerves or abdominal wall afferent nerves. Diagnosis is supported by signs or symptoms traversing clinical, diagnostic and functional criteria. Included is a tool which can assist clinicians in diagnosing patients with CADS per those domains. We hope to facilitate primary care physicians' and gastroenterologists' utilization of our criteria to provide guidance for selecting which patients may benefit from further interventions or evaluation by a pain physician. The pain physician may then offer interventions to provide the patient with relief.

Peripheral Nerve Stimulation for the Treatment of Superior Cluneal Neuralgia: A Cadaver Demonstration of a Novel Technique for Lead Placement.

Superior cluneal neuralgia (SCN) is a distinct cause of lower back and/or leg pain related to pathology of the superior cluneal nerve. When assessing a patient with low back pain (LBP), superior cluneal neuralgia is frequently misdiagnosed. The pathophysiology of SCN ranges from myofascial compression brought on by aberrant muscle tone to direct iatrogenic injury or trauma. In this technical report we will discuss the anatomy of superior cluneal nerve, superior cluneal neuralgia, current treatment modalities, and a novel approach to peripheral nerve stimulation (PNS) lead placement via a cadaver demonstration for SCN.

Novel Implantation Technique for Thoracoabdominal Peripheral Nerve Stimulation via a Transversus Abdominal Plane Approach for Treatment of Chronic Abdominal Pain.

Background: Chronic abdominal pain (CAP) is a common and challenging to treat condition with a global prevalence of up to 25%. Despite extensive evaluation, approximately 40% of patients with CAP have an unknown diagnosis. Medications may be ineffective, and surgery is rarely indicated. Interventional treatment including sympathetic blocks, sympathetic neurolysis, and transversus abdominal plane (TAP) blocks may be an option, but their efficacy can wane over time. Neuromodulation has emerged as an option for these patients, as there is evidence of success with dorsal column spinal cord and dorsal root ganglion (DRG) stimulation. Peripheral nerve stimulation (PNS) may be an alternative option, particularly in higher risk patients or in patients for whom neuraxial access may be unsafe or too technically challenging. Thoracoabdominal nerve peripheral nerve stimulation via a TAP approach may be more specifically targeted in comparison to dorsal column or DRG stimulation. In this short report, we detail a technique that the authors have successfully used for thoracoabdominal nerve PNS via a TAP approach for management of CAP. Methods: This article describes a novel medial to lateral ultrasound guided thoracoabdominal nerve PNS via a TAP approach technique for lead placement and implantation. Results: A medial to lateral ultrasound guided TAP approach as described to successfully implant percutaneous thoracoabdominal nerve PNS leads for management of CAP. Conclusion: The thoracoabdominal nerve PNS via a TAP approach lead placement technique noted in this report has been used as a means for management of CAP utilizing peripheral neuromodulation. Here, we present a short report detailing a potential technique for PNS utilization for management of CAP. Further studies are needed to validate the safety and efficacy of this therapy modality, although the authors have found it to be a viable management option for patients with medically refractory neuropathic CAP.

Mitigating Factors in L4 and L5 Medial Branch Motor Stimulation During Radiofrequency Ablation.

PURPOSE OF REVIEW: Radiofrequency ablation (RFA) is a minimally invasive procedure for facet joint pain. The targets for the procedure are the medial branches of the dorsal spinal nerves which innervate the facet joints. Before RFA, patients undergo diagnostic meal branch blocks to ensure appropriate pain relief and confirm the utility of proceeding to RFA. The success of RFA relies heavily on procedural technique and accurate placement near the medial branch. RECENT FINDINGS: Motor testing is utilized in the lumbar region to assess the response of the multifidus and ensure proper placement of the RFA probe to prevent inadvertent damage to surrounding spinal anatomy. However, relying on motor responses in this area presents challenges given the frequency of lack of muscle twitching. Factors contributing to limited muscle twitch responses include muscle atrophy, excessive lordosis, facet arthropathy, local anesthetic use before ablation, and previous surgical neurotomy. These complexities highlight the challenges in ensuring precise motor stimulation during RFA. Despite these obstacles, accurate anatomical placement remains crucial. For RFA cases that prove challenging, relying on anatomical placement can be adequate to proceed with the procedure. Bridging knowledge gaps is vital for standardized practices and safer procedures. Further research is necessary to refine techniques, understand patient-specific factors, and enhance the efficacy of RFA in managing chronic lumbar facet joint pain.

Literature Review: Mechanism, Indications, and Clinical Efficacy of Peripheral Nerve Stimulators in Lower Extremity Pain.

PURPOSE OF REVIEW: Lower extremity pain is deemed by Center for Disease Control and Prevention (CDC) to be a significant source of chronic pain in adults. If not appropriately managed, patients are subjected to risks of prolonged musculoskeletal dysfunction, disruption to quality of life, and elevated healthcare expenditures. Peripheral nerve stimulation (PNS) has shown great potential in recent years demonstrating efficacy in multiple diagnoses ranging from acute post-surgical pain to complex regional pain syndrome (CRPS). This study seeks to delineate efficacy of peripheral neuromodulation in the context of chronic lower extremity pain. RECENT FINDINGS: Prevailing clinical studies demonstrate evidence levels ranging from II to V (Oxford Centre of Level of Evidence) in lower limb PNS, attaining positive outcomes in pain scores, opioid use, and quality of life measures. Nerves most frequently targeted are the sciatic and femoral nerves with post-amputation pain and CRPS most commonly investigated for efficacy. PNS is a promising therapeutic modality demonstrated to be effective for a variety of nociceptive and neuropathic pain conditions in the lower extremity. PNS offers chronic pain physicians a powerful tool in the multi-modal management of lower limb chronic pain.

Pudendal nerve blockade for persistent genital arousal disorder (PGAD): A clinical review and case report.

BACKGROUND: Persistent genital arousal disorder (PGAD) is a condition characterized by unwanted and potentially painful genital sensations or spontaneous orgasms without stimulation. We present a case of a 55-year-old woman with refractory genital arousal disorder that was treated with serial pudendal nerve blocks. CASE: RW is a 55-year-old woman with chronic pelvic pain, pudendal neuralgia, MDD, SI, GAD, CRPS, and persistent genital arousal disorder for 11 years. Her PGAD was refractory to conservative management, physical therapy, and bilateral clitoral artery embolization. We performed bilateral pudendal nerve blocks with Kenalog and Bupivacaine, which provided almost complete relief for 2-3 months. We performed a bilateral pudendal nerve radiofrequency ablation; however, there was minimal benefit. RW continues to have significant relief with serial pudendal nerve blocks. SUMMARY AND CONCLUSION: Persistent genital arousal disorder is often refractory to medication and physical therapy requiring significant intervention such as entrapment surgery or artery embolization. Our case demonstrates pudendal nerve blocks as a potential treatment modality with minimal side effects.

Neuromodulation Techniques for Headache Management.

This narrative review aims to summarize evidence regarding the current utilization and future applications of neuromodulation in patients with headaches, with special attention paid to migraine and chronic cluster headache. A search was conducted in PubMed in August of 2023 to survey the current literature on neuromodulation for the treatment of headache. In total, the search yielded 1989 results, which were further filtered to include only systematic reviews published between 2022 to 2023 to capture the most up-to-date and comprehensive research on this topic. The citation lists of these articles were reviewed to find additional research on neuromodulation and supplement the results presented in this paper with primary literature. Research on the use of neuromodulation for the treatment of headache has predominantly focused on four neuromodulation techniques: peripheral nerve stimulation (PNS), transcranial magnetic stimulation (TMS), deep brain stimulation (DBS), and spinal cord stimulation (SCS). Outcome measures reported in this article include impact on migraine and headache frequency and/or pain intensity, adverse effects of the neuromodulation technique, and associated costs, when available. We found that neuromodulation has developed utility as an alternative treatment for both chronic cluster headaches and migraines, with a reduction in frequency and intensity of headache most elucidated from the articles mentioned in this review.

The Role of Orthoses in Chronic Axial Spinal Conditions.

PURPOSE OF REVIEW: Bracing represents a prevalent conservative, non-surgical approach used in the management of chronic spinal conditions such as spondylosis, degenerative disc disease, and spondylolisthesis. A wide variety of orthoses are available to aid in addressing cervical, thoracic, lumbar, thoracic, and SI joint pain. In this review, we aim to comprehensively examine brace types with their current applications and implications of usage. RECENT FINDINGS: There are multiple cervical bracing options, such as soft and rigid collars, to assist in managing acute trauma and chronic degenerative conditions. The review highlights the nuanced decision-making process between hard and soft collars based on the severity of bone or ligamentous injury and neurological findings. Orthoses for low back pain are commonly used. The review highlights the challenges of chronic neck and lower back pain, emphasizing the importance of clinicians exploring all treatment strategies including braces which can improve function and reduce pain.

Sacroiliac Joint Denervation-A Novel Approach to Target Sacral Lateral Branches: A Practical Approach.

INTRODUCTION: Sacroiliac joint (SIJ) pain is a relatively common cause of low back pain. Percutaneous radiofrequency (RF) techniques for SIJ are limited to ablation of the posterior SIJ innervation. Different techniques have been described for SIJ radiofrequency ablation, including conventional thermal, cooled RF, pulsed RF, bipolar RF, and specialized tip RF needle (i.e., multi-tined); however, additional costs may limit these applications. METHODS: This new technique for SIJ denervation uses anatomical landmarks and a single RF cannula. Two spinal needles are placed lateral to the posterior S1 and S2 sacral foramina; then, with caudal tilt we get a coaxial view of the sacral bone, we advance an 18-G curved 15-mm active tip RF cannula just lateral to the aligned finder needles. Ablation is performed, and then the RF cannula is retracted 2 cm and ablation is repeated for a total of four lesions. RESULTS: The two spinal needles placed lateral to the posterior sacral foramina S1 and S2 guide the final needle in the posterior aspect of the sacrum, lateral to the sacral foramina, where the lateral sacral branches are located. CONCLUSION: We introduce a cost and time efficient technique to perform radiofrequency ablation of the sacral lateral branches using a single RF needle. This technique utilizes the sacrum's reliable anatomy and angulation and maximizes the surface area of the active tip lesioning. This technique creates a strip lesion lateral to the sacral foramina and reduces time and cost efficacy compared to several of the other techniques and/or commercially available special devices designed for sacroiliac denervation.

Applications of Artificial Intelligence in Pain Medicine.

PURPOSE OF REVIEW: This review explores the current applications of artificial intelligence (AI) in the field of pain medicine with a focus on machine learning. RECENT FINDINGS: Utilizing a literature search conducted through the PubMed database, several current trends were identified, including the use of AI as a tool for diagnostics, predicting pain progression, predicting treatment response, and performance of therapy and pain management. Results of these studies show promise for the improvement of patient outcomes. Current gaps in the research and subsequent directions for future study involve AI in optimizing and improving nerve stimulation and more thoroughly predicting patients' responses to treatment.

The Gut Microbiota and Chronic Pain.

PURPOSE OF REVIEW: To examine the effects and interactions between gut microbia and chronic pain. RECENT FINDINGS: The gut microbiome has been an area of interest in both the scientific and general audience due to a growing body of evidence suggesting its influence in a variety of health and disease states. Communication between the central nervous system (CNS) and gut microbiome is said to be bidirectional, in what is referred to as the gut-brain axis. Chronic pain is a prevalent costly personal and public health burden and so, there is a vested interest in devising safe and efficacious treatments. Numerous studies, many of which are animal studies, have been conducted to examine the gut microbiome's role in the pathophysiology of chronic pain states, such as neuropathy, inflammation, visceral pain, etc. As the understanding of this relationship grows, so does the potential for therapeutic targeting of the gut microbiome in chronic pain.

Novel ultrasound-guided supraclavicular stellate ganglion block.

INTRODUCTION: Stellate ganglion block (SGB) provides diagnostic and therapeutic benefits in pain syndromes in the head, neck, and upper extremity, including complex regional pain syndrome Types I and II, Raynaud's disease, hyperhidrosis, arterial embolism in the region of the arm. METHODS: We present a novel ultrasound-guided supraclavicular stellate ganglion block. Considering the existing anatomical structures of the targeted area. RESULTS AND CONCLUSIONS: We hope that we can provide fewer complications and additional benefits with this new approach.

Infrapatellar Branch of the Saphenous Nerve: Therapeutic Approaches to Chronic Knee Pain.

PURPOSE OF REVIEW: The infrapatellar branch of the saphenous nerve (IPS) is an under-investigated nerve that can be a source of chronic knee pain. This literature review aims to deliver an up-to-date review of chronic pain transmitted via the IPS along with therapeutic approaches available for pain refractory to conservative measures. RECENT FINDINGS: Knee pain transmitted via the IPS can arise from several etiologies. Damage to the IPS is often iatrogenic and develops following total knee arthroplasty, anterior cruciate ligament reconstruction, and other knee surgical procedures. Other causes of IPS-derived pain include entrapment of the nerve, neuromas, Schwannomas, and pain from knee osteoarthritis transmitted through the IPS.This article investigated therapeutic approaches to pain derived from the IPS. Common approaches included radiofrequency ablation, neuroma excisions, Schwannoma excision, nerve blocks, surgical exploration, surgical release of an entrapped nerve, cryoablation, and peripheral nerve stimulation. Pain scores, duration of pain relief, adverse events, and secondary outcomes were all included in this review. A subset of the patient population experiences chronic pain deriving from the IPS that is refractory to conservative treatment measures. This review aims to evaluate the etiologies and therapeutic approaches for chronic pain arising from the IPS refractory to conservative treatments.

Dorsal root ganglion stimulation (DRG-s) for potential resolution of restless leg syndrome symptoms and increased cost savings for patients: A case study.

INTRODUCTION: We report successful use of dorsal root ganglion stimulation (DRG-s) to treat a patient with persistent symptoms of restless leg syndrome (RLS). METHODS: The treatment involved the placement of a small device millimeters away from the patient's DRG, which are nerves near the spinal cord that carry sensory information from the periphery of the body to the brain. The device automatically delivers electrical impulse to the DRG to alter and decrease pain perception in the brain. RESULTS: Our case report elucidates the use of this procedure as a targeted therapy for RLS, with a nearly 90% reduction in reported symptoms in our patient, thus potentially reducing morbidity associated with this condition. Furthermore, we report a 10-year cost savings of nearly $90,000 following DRG-s for our patient. CONCLUSION: This case study aims to demonstrate the effectiveness of DRG-s neuromodulation in managing RLS, a condition that is often difficult and costly to treat.

Peripheral Nerve Stimulation With a High-Frequency Electromagnetic Coupled Powered Implanted Receiver at the Posterior Tibial Nerve for the Treatment of Chronic Pain in the Foot.

INTRODUCTION: Peripheral neuropathy has several causes, with diabetes being the most common. Conservative management may fail to control pain. Our study aimed at evaluating the use of peripheral nerve stimulation of the posterior tibial nerve for treating peripheral neuropathy. MATERIALS AND METHODS: This was an observational study of 15 patients who received peripheral nerve stimulation at the posterior tibial nerve to treat peripheral neuropathy. Outcomes measured were improvement of pain scores and Patient Global Impression of Change (PGIC) at 12 months compared with before the implant. RESULTS: Mean pain scores with the verbal rating scale were 3 ± 1.8 at >12 months compared with 8.6 ± 1.2 at baseline, a reduction of 65% (p < 0.001). Median satisfaction with the PGIC at >12 months was 7 of 7, with most subjects reporting a 6 (better) or a 7 (a great deal better). CONCLUSION: Peripheral nerve stimulation of the posterior tibial nerve can be a safe and effective modality for treating chronic pain symptoms related to peripheral neuropathy of the foot.