Diabetic Neuropathy: A Guide to Pain Management.

PURPOSE OF REVIEW: Diabetic neuropathy is a common complication of diabetes mellitus (DM) and can affect up to 50% of DM patients during their lifetime. Patients typically present with numbness, tingling, pain, and loss of sensation in the extremities. Since there is no treatment targeting the underlying mechanism of neuropathy, strategies focus on preventative care and pain management. RECENT FINDINGS: Up to 69% of patients with diabetic neuropathy receive pharmacological treatment for neuropathic pain. The United States Food and Drug Administration (FDA) confirmed four drugs for painful diabetic neuropathy (PDN): pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch. Nonpharmacological treatments such as spinal cord stimulation (SCS) and transcutaneous electrical nerve stimulation (TENS) both show promise in reducing pain in DM patients. Despite the high burden associated with PDN, effective management remains challenging. This update covers the background and management of diabetic neuropathy, including its epidemiology, pathogenesis, preventative care, and current therapeutic strategies.

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.

Reviewing the Potential Role of Artificial Intelligence in Delivering Personalized and Interactive Pain Medicine Education for Chronic Pain Patients.

The integration of artificial intelligence (AI) in patient pain medicine education has the potential to revolutionize pain management. By harnessing the power of AI, patient education becomes more personalized, interactive, and supportive, empowering patients to understand their pain, make informed decisions, and actively participate in their pain management journey. AI tailors the educational content to individual patients' needs, providing personalized recommendations. It introduces interactive elements through chatbots and virtual assistants, enhancing engagement and motivation. AI-powered platforms improve accessibility by providing easy access to educational resources and adapting content to diverse patient populations. Future AI applications in pain management include explaining pain mechanisms, treatment options, predicting outcomes based on individualized patient-specific factors, and supporting monitoring and adherence. Though the literature on AI in pain medicine and its applications are scarce yet growing, we propose avenues where AI may be applied and review the potential applications of AI in pain management education. Additionally, we address ethical considerations, patient empowerment, and accessibility barriers.

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.

Pain Scales: What Are They and What Do They Mean.

PURPOSE OF REVIEW: It is essential to have validated and reliable pain measurement tools that cover a wide range of areas and are tailored to individual patients to ensure effective pain management. The main objective of this review is to provide comprehensive information on commonly used pain scales and questionnaires, including their usefulness, intended purpose, applicability to different patient populations, and associated advantages and disadvantages. RECENT FINDINGS: Acute pain questionnaires typically focus on measuring the severity of pain and the extent of relief achieved through interventions. Chronic pain questionnaires evaluate additional aspects such as pain-related functional limitations, psychological distress, and psychological well-being. The selection of an appropriate pain scale depends on the specific assessment objectives. Additionally, each pain scale has its strengths and limitations. Understanding the differences among these pain scales is essential for selecting the most appropriate tool tailored to individual patient needs in different settings. CONCLUSION: Medical professionals encounter challenges in accurately assessing pain. Physicians must be familiar with the different pain scales and their applicability to specific patient population.

Discrepancy Between Reported and Calculated Pain Reduction in Patients With Spinal Cord Stimulation Therapy and Lack of Agreement Between Patient Satisfaction and Degree of Pain Relief.

OBJECTIVES: This study aimed to determine agreement between reported percentage pain reduction (RPPR) and calculated percentage pain reduction (CPPR) in patients with percutaneous spinal cord stimulation (SCS) implants, and to correlate RPPR and CPPR with patient satisfaction. We also sought to determine which patient-reported outcome measures are most improved in patients with SCS. MATERIALS AND METHODS: Fifty patients with percutaneous spinal cord stimulator implants with a mean follow-up of 51.1 months were interviewed and surveyed to assess their pain level, impression of degree of pain relief, satisfaction with the therapy, and desire to have the device again. Baseline pain level was obtained from their preimplant records. RESULTS: Overall, RPPR was found to be 53.3%, whereas CPPR was 44.4%. Of all patients, 21 reported <50% pain reduction; however, most of these (12/21, 57%) were satisfied with the outcome of therapy. In terms of individual improvement in outcomes, activities of daily life was the most improved measure at 82%, followed by mood, sleep, medication use, and health care utilization at 74%, 62%, 50%, and 48%, respectively. CONCLUSIONS: RPPR appears to be a complex outcome measure that may not agree with CPPR. Overall RPPR is greater than the CPPR. On the basis of our data, these independently valid measures should not be used interchangeably. A 50% pain reduction threshold is not a requisite for patient satisfaction and desire to have the device again. Activities of daily living was the most improved measure in this cohort, followed by mood, sleep, medication usage, and decrease in health care utilization.

Review: Discogenic Back Pain: Update on Treatment.

Purpose of Review: Lower back pain (LBP) has a lifetime prevalence of 80% in the United States population. Discogenic back pain (DBP), a subcategory of LBP, occurs as a result of the interverbal disc degeneration without disc herniation. Diagnosis relies on history, physical exam, and imaging such as MRI, provocative discography, or CT discography. Recent Findings: Treatment of DBP involves a multifaceted approach with an emphasis on conservative measures including behavioral modification, pharmacologic management, and other non-pharmacologic interventions with invasive therapy reserved for select patients. Due to the paucity of data on the treatment of DBP, treatment also relies on data derived from treatment of chronic LBP (CLBP). Summary: Despite the scarcity of data for the treatment of DBP, treatments do exist with varying efficacy for DBP. Novel techniques such as the use of biologics may provide another avenue for treatment though further studies are needed to better evaluate the most efficacious regimen for both novel and existing treatments.

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.

Notalgia Paresthetica Review: Update on Presentation, Pathophysiology, and Treatment.

PURPOSE OF REVIEW: Notalgia paresthetica (NP) is a chronic cutaneous neuropathy primarily characterized by localized pruritus and associated dysesthesias, including sensations of pain, numbness, and tingling. The sensory neuropathy characteristic of NP is thought to result from spinal nerve entrapment caused by degenerative changes in the spine or musculoskeletal compression. This review summarizes the current medical literature with a focus on the past five years regarding NP, its pathophysiology, presentation, and current treatment options. RECENT FINDINGS: Though treatments exist with varying efficacy, to date, there exists no definitive treatment for NP. Treatment options for NP are varied and range from topical and oral agents to interventional procedures and physical therapy. Of the treatments evaluated, topical capsaicin remains the most efficacious treatment for NP. CONCLUSIONS: The lack of established treatment guidelines makes treating NP complicated as it dramatically affects patients' quality of life. Further research with larger sample sizes is needed to evaluate better the most effective treatment and dosing regimen for patients afflicted with NP.

A Survey on the Choice of Spinal Cord Stimulation Parameters and Implantable Pulse Generators and on Reasons for Explantation.

Objective: Spinal Cord Stimulation (SCS) is a vital treatment for chronic intractable pain. In the last few years, the field has undergone dramatic changes in new waveform and frequency introduction as well as device miniaturization. It is important to understand contemporary practice patterns regarding these parameters. Methods: We surveyed the active membership of Spine Intervention Society (SIS), and American Society of Regional Anesthesia (ASRA) on their practices regarding various aspects of Spinal Cord Stimulation therapy. Here we report on SCS waveform usage, battery types, and causes of explant in this cohort of providers. Results: There was similar degree of usage of tonic, burst, and 10 kHz usage at 71.5%, 74.1% and 61.7% respectively. Dorsal root ganglion stimulation was used by 32.6% and other modes of stimulation by 13.5%. Rechargeable systems were often or always used by 67.2% whereas 10% never used a rechargeable system. Most common cause of explant was loss of effectiveness, reported by 53.7%. Conclusion: There has been significant adoption of new waveforms in daily practice of spinal cord stimulation therapy and there is robust mixed usage of new waveforms and frequencies. Rechargeable systems are the most commonly used but primary cell is also used in significant numbers. Loss of efficacy remains the most common cause of explant for the majority of practitioners. This survey establishes practice patterns of SCS usage regarding these important variables against which future changes can be gauged.

A Comprehensive Review of Zavegepant as Abortive Treatment for Migraine.

Migraine headache is a widespread and complex neurobiological disorder that is characterized by unilateral headaches that are often accompanied by photophobia and phonophobia. Migraine is one of the leading chief complaints in the emergency department with negative impacts on quality of life and activities of daily living. The high number of emergency presentations also results in a significant economic burden. Its risk factors include family history, genetics, sex, race, socioeconomics, the existence of comorbid conditions, and level of education. Triggers include stress, light, noise, menstruation, weather, changes in sleep pattern, hunger, dehydration, dietary factors, odors, and alcohol. The International Headache Society has defined criteria for the diagnosis of migraine with and without aura. The pathophysiology of migraine headaches is multifactorial so there are a variety of treatment approaches. The current treatment approach includes abortive medications and prophylactic medications. Abortive medications include the first-line treatment of triptans, followed by ergot alkaloids, and calcitonin gene-related peptide (CGRP) receptor antagonists along with supplemental caffeine and antiemetics. Trigeminal afferents from the trigeminal ganglion innervate most cranial tissues and many areas of the head and face. These trigeminal afferents express certain biomarkers such as calcitonin gene-related peptide (CGRP), substance P, neurokinin A, and pituitary adenylate cyclase-activating polypeptide that are important to the pain and sensory aspect of migraines. In this comprehensive review, we discuss Zavegepant, a calcitonin gene-related peptide receptor antagonist, as a new abortive medication for migraine headaches.

Meralgia Paresthetica.

PURPOSE OF REVIEW: This review article summaries the epidemiology, etiology, clinical presentations, and latest treatment modalities of meralgia paresthetica, including the latest data about peripheral and spinal cord stimulation therapy. Meralgia paresthetica (MP) causes burning, stinging, or numbness in the anterolateral part of the thigh, usually due to compression of the lateral femoral cutaneous nerve (LFCN). RECENT FINDINGS: There are emerging data regarding the benefit of interventional pain procedures, including steroid injection and radiofrequency ablation, and other interventions including spinal cord and peripheral nerve stimulation reserved for refractory cases. The strength of evidence for treatment choices in meralgia paraesthetica is weak. Some observational studies are comparing local injection of corticosteroid versus surgical interventions. However, more extensive studies are needed regarding the long-term benefit of peripheral and spinal cord stimulation therapy.

Trends in US Ambulatory Care Patterns During the COVID-19 Pandemic, 2019-2021.

Importance: Following reductions in US ambulatory care early in the pandemic, it remains unclear whether care consistently returned to expected rates across insurance types and services. Objective: To assess whether patients with Medicaid or Medicare-Medicaid dual eligibility had significantly lower than expected return to use of ambulatory care rates than patients with commercial, Medicare Advantage, or Medicare fee-for-service insurance. Design, Setting, and Participants: In this retrospective cohort study examining ambulatory care service patterns from January 1, 2019, through February 28, 2021, claims data from multiple US payers were combined using the Milliman MedInsight research database. Using a difference-in-differences design, the extent to which utilization during the pandemic differed from expected rates had the pandemic not occurred was estimated. Changes in utilization rates between January and February 2020 and each subsequent 2-month time frame during the pandemic were compared with the changes in the corresponding months from the year prior. Age- and sex-adjusted Poisson regression models of monthly utilization counts were used, offsetting for total patient-months and stratifying by service and insurance type. Exposures: Patients with Medicaid or Medicare-Medicaid dual eligibility compared with patients with commercial, Medicare Advantage, or Medicare fee-for-service insurance, respectively. Main Outcomes and Measures: Utilization rates per 100 people for 6 services: emergency department, office and urgent care, behavioral health, screening colonoscopies, screening mammograms, and contraception counseling or HIV screening. Results: More than 14.5 million US adults were included (mean age, 52.7 years; 54.9% women). In the March-April 2020 time frame, the combined use of 6 ambulatory services declined to 67.0% (95% CI, 66.9%-67.1%) of expected rates, but returned to 96.7% (95% CI, 96.6%-96.8%) of expected rates by the November-December 2020 time frame. During the second COVID-19 wave in the January-February 2021 time frame, overall utilization again declined to 86.2% (95% CI, 86.1%-86.3%) of expected rates, with colonoscopy remaining at 65.0% (95% CI, 64.1%-65.9%) and mammography at 79.2% (95% CI, 78.5%-79.8%) of expected rates. By the January-February 2021 time frame, overall utilization returned to expected rates as follows: patients with Medicaid at 78.4% (95% CI, 78.2%-78.7%), Medicare-Medicaid dual eligibility at 73.3% (95% CI, 72.8%-73.8%), commercial at 90.7% (95% CI, 90.5%-90.9%), Medicare Advantage at 83.2% (95% CI, 81.7%-82.2%), and Medicare fee-for-service at 82.0% (95% CI, 81.7%-82.2%; P < .001; comparing return to expected utilization rates among patients with Medicaid and Medicare-Medicaid dual eligibility, respectively, with each of the other insurance types). Conclusions and Relevance: Between March 2020 and February 2021, aggregate use of 6 ambulatory care services increased after the preceding decrease in utilization that followed the onset of the COVID-19 pandemic. However, the rate of increase in use of these ambulatory care services was significantly lower for participants with Medicaid or Medicare-Medicaid dual eligibility than for those insured by commercial, Medicare Advantage, or Medicare fee-for-service.

Improved Pain Control with Combination Spinal Cord Stimulator Therapy Utilizing Sub-perception and Traditional Paresthesia Based Waveforms: A Pilot Study.

BACKGROUND: Chronic back and neck pain affects 20% of Americans. Spinal cord stimulation (SCS) is an effective therapy for otherwise refractory chronic pain. Traditional SCS relies on low-frequency stimulus in the 40 - 60 Hz range causing robust paresthesia in regions overlapping with painful dermatomes. OBJECTIVES: This study aims to determine the effect of superimposing sub-perception stimulation in patients who previously had good long-term relief with paresthesia. METHODS: This is a prospective observational trial examining patients who had previously been implanted with paresthesia based SCS for failed back surgery syndrome (FBSS) or complex regional pain syndrome (CRPS). These patients presented for implantable pulse generator (IPG) replacement based on battery depletion with an IPG capable of combined sub-perception and paresthesia based SCS therapy. Patients were assessed immediately following the exchange and four weeks later using a telephone survey. Their pain was assessed on each follow up using a Numerical Rating scale (NRS); the primary outcome was the change in NRS after four weeks from the exchange day. Secondary outcomes included paresthesia changes, which included the subjective quality of sensation generated, the overall subjective coverage of the painful region, subjective variation of coverage with positional changes, and global perception of the percentage improvement in pain. RESULTS: Based on our clinic registry, 30 patients were eligible for IPG exchange, 16 were consented for follow up and underwent an exchange, and 15 were available for follow up four weeks following. The average NRS decreased from 7.47 with traditional SCS to 4.5 with combination therapy. 80% of patients reported an improvement in the quality of paresthesia over traditional SCS therapy, and in most patients, this translated to significantly improved pain control. CONCLUSIONS: Our findings suggest improved pain relief in patients who had previously had good results with paresthesia based therapy and subsequently underwent IPG exchange to a device capable of delivering combined sub-perception stimulation. The mechanism of action is unclear though there may be an additive and/or synergistic effect of the two waveforms delivered. Larger studies with long-term follow-up are needed to elucidate the durability of pain relief and the precise mechanism by which combined subperception and paresthesia based SCS may improve overall patient outcomes.

Successful Reimplantation of Spinal Cord Stimulator One Year after Device Removal Due to Infection.

Spinal cord stimulation is an effective treatment modality for patients with numerous pain conditions. Although proven to be highly successful, device implantation does come with some inherent risks. One of the most challenging complications is perioperative infection. For most patients, a simple trial of oral antibiotics and in-office drainage of any superficial infectious material may be sufficient. Deeper infections with wound dehiscence necessitate device removal and intravenous antibiotic therapy. The question remains, if the device was previously providing pain relief for the patient, when is the appropriate time to reimplant the device after the infection has cleared? We describe the case of explantation of an infected device and successful reimplantation after 1 year.

Cannabis and cannabidiol (CBD) for the treatment of fibromyalgia.

Fibromyalgia is a complex disease process that is as prevalent as it is poorly understood. Research into the pathophysiology is ongoing, and findings will likely assist in identifying new therapeutic options to augment those in existence today that are still insufficient for the care of a large population of patients. Recent evidence describes the use of cannabinoids in the treatment of fibromyalgia. This study provides a systematic, thorough review of the evidence alongside a review of the seminal data regarding the pathophysiology, diagnosis, and current treatment options. Fibromyalgia is characterized by widespread chronic pain, fatigue, and depressive episodes without an organic diagnosis, which may be prevalent in up to 10% of the population and carries a significant cost in healthcare utilization, morbidity, a reduced quality of life, and productivity. It is frequently associated with psychiatric comorbidities. The diagnosis is clinical and usually prolonged, and diagnostic criteria continue to evolve. Some therapies have been previously described, including neuropathic medications, milnacipran, and antidepressants. Despite some level of efficacy, only physical exercise has strong evidence to support it. Cannabis has been used historically to treat different pain conditions since ancient times. Recent advances allowed for the isolation of the active substances in cannabis and the production of cannabinoid products that are nearly devoid of psychoactive influence and provide pain relief and alleviation of other symptoms. Many of these, as well as cannabis itself, are approved for use in chronic pain conditions. Evidence supporting cannabis in chronic pain conditions is plentiful; however, in fibromyalgia, they are mostly limited. Only a handful of randomized trials exists, and their objectivity has been questioned. However, many retrospective trials and patient surveys suggest the significant alleviation of pain, improvement in sleep, and abatement of associated symptoms. Evidence supporting the use of cannabis in chronic pain and specifically in fibromyalgia is being gathered as the use of cannabis increases with current global trends. While the current evidence is still limited, emerging data do suggest a positive effect of cannabis in fibromyalgia. Cannabis use is not without risks, including psychiatric, cognitive, and developmental as well as the risks of addiction. As such, clinical judgment is warranted to weigh these risks and prescribe to patients who are more likely to benefit from this treatment. Further research is required to define appropriate patient selection and treatment regimens.

Obesity Trends Amongst Hospitalized Patients with Spinal Cord Stimulator Implants.

INTRODUCTION: Chronic pain remains an important public health problem as it continues to increase healthcare-related cost. Comorbidities like obesity have been associated with efficacy of spinal cord stimulator (SCS) therapy and worse outcomes. The goal of this study is to investigate the trends of obesity amongst hospitalized patients with SCS therapy as well as healthcare utilization outcomes. METHODS: Using the International Classification of Diseases (ICD) ninth and tenth procedure and diagnosis code, we investigated the National Inpatient Sample (NIS) for patients with SCS implants between 2011 and 2015. Patients received a diagnosis of obesity based on the following categories: class I, II and III obesity. Age, gender, and comorbid conditions of patients with obesity were matched 1:1 on propensity score to those without obesity diagnosis. Our primary outcome was defined as trend of obesity diagnosis. Our secondary outcome, healthcare utilization, included in-hospital cost, length of stay, and discharge location. RESULTS: Between 2011 and 2015, a total of 3893 patients with SCS implants were identified (average age 56 ± 15 years, 58% female, 0.70 ± 1.1 Charlson Comorbidity Index, CCI). Of this cohort, 640 patients were identified as obese. The proportion of patients with obesity diagnosis increased significantly from 13.75% in 2011 to 19.36% in 2015 (p < 0.001). After 1:1 matching on propensity score, 597 patients with obesity were successfully matched to 597 patients without obesity. The total hospital cost for SCS patients with obesity (median $104,845, IQR $74,648-144,292) was not significantly different from patients without obesity diagnosis (median $111,092, IQR $68,990-145,459) (p = 0.161). CONCLUSIONS: The data from our study suggests that there is an increasing rate of obesity diagnosis amongst patients with SCS therapy. However, there was no difference in healthcare utilization between patients with and without obesity. Additional studies may provide more insight into our findings.