Oral and Topical Treatment of Painful Diabetic Polyneuropathy: Practice Guideline Update Summary: Report of the AAN Guideline Subcommittee

AAN Position: Opioids

This position statement serves to establish the American Academy of Neurology (AAN)'s stance on neurology care team's needs for safe prescribing of opioids and research for nonopioid pain alternatives so that the AAN can continue to advocate effectively for its members. While considerable improvements have been made in prescribing practices to address patient pain, opioids remain the most misused prescription medication in the United States. Neurology care teams often care for patients with chronic, complex conditions that include pain disorders such as migraine, peripheral neuropathy, traumatic brain injury, multiple sclerosis, and low back pain and are the 14th most frequent group to prescribe opioids. The AAN is dedicated to upstream approaches to prevent opioid misuse through research aimed at finding alternative therapies for chronic pain, reducing opioid addiction and misuse, and using tools such as electronic prescribing of controlled substances and state prescription monitoring programs to improve the safety of opioid prescribing when opioid treatment is necessary.

CASPAR: a retrospective cohort study of the high-concentration capsaicin topical system in patients with painful diabetic peripheral neuropathy of the feet

INTRODUCTION

Painful diabetic peripheral neuropathy (pDPN), a common complication of diabetes, is challenging to treat and negatively impacts quality of life (QoL). Many patients either fail to achieve adequate pain relief with current treatments or suffer from systemic side effects with oral options. This study used data from the German Pain e-Registry (GPeR) to evaluate the high-concentration capsaicin topical system (HCCTS) for treating pDPN of the feet.

RESEARCH DESIGN AND METHODS

This retrospective, non-interventional cohort study (CASPAR) included patients with pDPN of the feet who received ≥1 HCCTS treatment (~3-month treatment intervals) and contributed data to the GPeR for ≥12 months. Data were collected on pain intensity, QoL, sleep, mood, concomitant medication, and tolerability.

RESULTS

Overall, 365 patients with pDPN of the feet were included. Significant reductions in 24-hour average pain intensity (API) were observed from baseline to month 3 (following one HCCTS treatment). Further reductions in mean API score were seen over 12 months with ongoing treatments, whereas API increased in patients who discontinued treatment (baseline to month 12 mean API scores: 61.4 to 8.8 for four HCCTS [∆ -52.6], 59.3 to 16.7 for three HCCTS [∆ -42.6], 56.3 to 31.9 for two HCCTS [∆ -24.4], 57.5 to 51.4 for one HCCTS [∆ -6.1]). Similar trends were seen for sleep, mood, and QoL outcomes. There was a significant reduction in concomitant pain medication use in patients receiving ongoing HCCTS treatments. The most common adverse events were local application-site reactions.

CONCLUSIONS

This real-world study in patients with pDPN of the feet demonstrates that ongoing HCCTS treatments continue to improve pain intensity, mood, and QoL, while concomitant medication use decreases. Benefits from treatment were lost following HCCTS discontinuation. These findings emphasize the importance of ongoing treatments to achieve the potential of HCCTS in improving outcomes for patients with pDPN.

Diabetic neuropathy: cutting-edge research and future directions

Diabetic neuropathy (DN) is a prevalent and debilitating complication of diabetes mellitus, significantly impacting patient quality of life and contributing to morbidity and mortality. Affecting approximately 50% of patients with diabetes, DN is predominantly characterized by distal symmetric polyneuropathy, leading to sensory loss, pain, and motor dysfunction, often resulting in diabetic foot ulcers and lower-limb amputations. The pathogenesis of DN is multifaceted, involving hyperglycemia, dyslipidemia, oxidative stress, mitochondrial dysfunction, and inflammation, which collectively damage peripheral nerves. Despite extensive research, disease-modifying treatments remain elusive, with current management primarily focusing on symptom control. This review explores the complex mechanisms underlying DN and highlights recent advances in diagnostic and therapeutic strategies. Emerging insights into the molecular and cellular pathways have unveiled potential targets for intervention, including neuroprotective agents, gene and stem cell therapies, and innovative pharmacological approaches. Additionally, novel diagnostic tools, such as corneal confocal microscopy and biomarker-based tests, have improved early detection and intervention. Lifestyle modifications and multidisciplinary care strategies can enhance patient outcomes. While significant progress has been made, further research is required to develop therapies that can effectively halt or reverse disease progression, ultimately improving the lives of individuals with DN. This review provides a comprehensive overview of current understanding and future directions in DN research and management.

Trends in Celecoxib Prescribing: A Single Institution 16-Month Review

Background/Objectives: Celecoxib, a COX-2 selective nonsteroidal anti-inflammatory drug (NSAID), is widely prescribed for pain management due to its efficacy and improved gastrointestinal safety profile compared to traditional NSAIDs. Understanding prescription trends and their comparison to other NSAIDs provides valuable insight into prescribing behaviors in clinical settings. Methods: This retrospective study analyzed celecoxib prescriptions written by three pain management physicians in a single institution over a 16-month period from 1 January 2023 to 30 April 2024. Prescription data were collected and grouped into four 4-month intervals to assess temporal trends. Additionally, we compared celecoxib prescriptions to other commonly prescribed NSAIDs, including ibuprofen, meloxicam, naproxen, and diclofenac. Results: A total of 143 celecoxib prescriptions were identified during the study period, with a steady increase observed across consecutive intervals: 8 prescriptions from January-April 2023, 22 from May-August 2023, 46 from September-December 2023, and 67 from January-April 2024. In comparison, a total of 165 prescriptions were written for other NSAIDs over the same period, with 26 prescriptions from January-April 2023, 41 from May-August 2023, 45 from September-December 2023, and 53 from January-April 2024. While prescriptions for both celecoxib and other NSAIDs increased over time, the rate of celecoxib prescriptions showed a steeper rise. Conclusions: The findings demonstrate a notable increase in celecoxib prescriptions in this pain management clinic, outpacing the growth of other NSAIDs. This trend may reflect increasing provider preference for COX-2 selective inhibitors due to their favorable safety profile and efficacy. Further research is warranted to explore the underlying factors driving these prescribing patterns.

Nonpharmaceutical treatment of distal sensorimotor polyneuropathy in diabetic patients: an unblinded randomized clinical trial

BACKGROUND

For Diabetic polyneuropathy, the most prevalent form of polyneuropathy, there is a lack of evidence-based treatment options. Current approaches include pain management, alpha-lipoic acid, and antidepressants. Physical interventions, such as electrical stimulation (four-chamber galvanic bath) have been suggested but have limited supporting evidence. Heated granular stone therapy is another option to consider.

METHODS

An unblinded randomized controlled trials was conducted in 68 diabetic patients with distal sensorimotor polyneuropathy undergoing rehabilitation for diabetes mellitus as a primary or secondary diagnosis in the Paracelsus-Harz-Clinic (Quedlinburg, Germany). Patients were randomized into either the intervention group receiving heated granulated stone footbaths, or the control group receiving four-chamber galvanic baths. The primary endpoint was the assessment of any change in polyneuropathy using a vibration sensation test (Rydel-Seiffer scale, 8/8) from admission to discharge, analyzed by t-test and multivariable regression. Additionally, serum TNF-α and IL-6 as potential markers for polyneuropathy were compared over time using paired t-test.

RESULTS

The mean age of the patients was 66.8 ± 7.8 years; 63.2% were male and mean BMI was 32.2 ± 6.4 kg/m2. Of the patients, 98.5% suffered from type 2 diabetes (one patient with type I diabetes); 82.4% were receiving oral antidiabetic medication; and 58.8% were insulin dependent. Distal sensorimotor polyneuropathy improved in both groups. The sum score increased from 16.7 to 22.6 in the study group and from 20.3 to 23.6 in the control group. A t-test showed a non-significant difference in the change of sum score between the treatment groups (2.6 points, p = 0.092), but adjusting for potential risk factors favors the intervention group (p = 0.043). Both analyzed markers decreased over time in each treatment group with IL-6 showing a clinical and significant reduction in the control group (p = 0.03).

CONCLUSION

Diabetic patients with distal sensorimotor polyneuropathy benefit from physical treatment with administration of electrical stimulation (four-chamber galvanic bath) or a therapy with heated granulated stones three times a week. Our results indicate that heated stone therapy may be a potential treatment option. However, further research is required to understand the underlying biological processes.

TRIAL REGISTRATION

The study was registered in clinical trials.gov (identifier: NCT05622630, registration date: 18/11/2022).

Implementation of Pharmacist Driven Gabapentinoid Titration for Diabetic Peripheral Neuropathy in a Primary Care Setting

Previous studies suggest that patients with diabetic peripheral neuropathy (DPN) frequently do not receive the minimum effective doses of a gabapentinoid according to guidance from national organizations. There is opportunity to assess the implementation of pharmacist intervention for patients not meeting minimum effective gabapentinoid dosing for DPN. This prospective, single site quality improvement project was conducted at a primary care clinic and included patients with DPN prescribed a gabapentinoid by their primary care provider (PCP) at a dose lower than minimum effective dosing. Pharmacists assessed patient-reported pain ratings, adverse effects, and renal function for appropriate dosing and titrated to minimum effective dosing based on clinical judgment. All patients that were followed through week 13 had a clinically significant improvement in pain. No patients met a 50% reduction in patient-reported pain rating scales on guidance-directed minimum effective dosing. No patients were able to meet the minimum effective dose. The majority of patients declined pharmacist services due to neuropathy being controlled on the current gabapentinoid dose. This study supports the ability for pharmacists to assess patient specific factors for adequate dosing, titration, and deprescribing recommendations for analgesic medications in diabetic peripheral neuropathy.

Rodent Models of Diabetic Neuropathy, Role of Calcium Homeostasis in Pain and KB-R7943 as a Potential Therapeutic

Diabetic neuropathy (DN) is characterized by nerve damage as a consequence of diabetes mellitus. Diabetes causes high blood glucose and triglyceride levels, which destroy the nerve blood vessels over time and trigger DN. Peripheral neuropathy is the most common type of DN, which encompasses a broad range of symptoms. One fourth of patients with diabetes suffer from neuropathic pain, which decreases their quality of life and puts them at high risk for emotional disturbances and depression. Finding an adequate therapy is an essential element in the cure of painful DN (PDN). Since the pathophysiology of this disease still needs to be elucidated, this has led to the development of various in vivo diabetic models. Animal models of DN not only provide insights into this disease but also are significant drivers for treatment assessment and improvement. In this review, we present the major features of the most commonly used chemically and diet-induced models of PDN in rodents and their progress to date, which are utilized for a better understanding of the disease mechanism for finding novel therapeutics. Considering the role of Ca2+ homeostasis in pain, we also review our recent research data on the Na+/Ca2+ exchanger blocker KB-R7943, which is a potential neuropathic pain reliever in a rodent model of DN.

Fast Analgesic Effect in Response Test with Topical Phenytoin Cream Correlates with Prolonged Pain Relief After Extended Use in Painful Diabetic Neuropathy

Background: Treatment of painful diabetic neuropathy (PDN) poses several challenges due to the limited effectiveness, high incidence of side effects, and potential drug interactions of oral neuropathic pain medication. Lacking systemic side effects, topical phenytoin cream offers a promising innovative approach to addressing unmet needs in neuropathic pain treatment. In this retrospective study in patients with PDN, we evaluated the analgesic effect of topical phenytoin cream in response tests and after extended use. Methods: We collected data from PDN patients who, prior to prolonged use of phenytoin 10% or 20% cream, either had an open response test (ORET), a single-blind (SIBRET), or a double-blind (DOBRET) placebo-controlled response test with phenytoin cream between November 2016 and February 2023. A positive ORET was defined as pain reduction of at least two points on the 11-point numerical scale (NRS) within 30 min after phenytoin cream application. A positive SIBRET or DOBRET required an additional pain reduction of 1 NRS point in the phenytoin treated area compared to the placebo. In patients with a positive response test, we evaluated the sustained pain reduction and the proportion of patients experiencing minimum pain relief of at least 30% (MPR30: moderate pain relief) and 50% (MPR50: considerable pain relief) after the extended use of phenytoin cream. We also assessed the correlation between the response test analgesic effect and the sustained pain relief. Results: We identified 65 patients with PDN of whom 31 (47.7%) had a positive response test. The median pain reduction in response tests was 3.0 NRS points (IQR 2.0-4.0). Extended use (median 3.3 months, IQR 1.5-12.1]) resulted in a median pain reduction of 4.0 NRS points (IQR 3.0-5.0); 26/31 (83.9%) of patients achieved MPR30, and 21/31 (67.7%) MPR50 achieved pain relief. The response test analgesic effect correlated significantly with sustained pain relief after extended use (τ = 0.72, p < 0.0001). Conclusions: In PDN patients who had a positive phenytoin cream response test, extended use of phenytoin cream provided a significant sustained pain relief.

Pharmacologic and Nonpharmacologic Management of Neuropathic Pain

Disorders of the somatosensory nervous system that cause neuropathic pain are treated in a variety of ways. Herein, we introduce a stepwise approach to treating neuropathic pain. We then summarize the available data and guidelines for treating neuropathic pain, both with pharmacologic and nonpharmacologic methods, and provide a synthesized algorithm highlighting the similarities and differences between recent guidelines on the management of neuropathic pain. Pharmacologic treatments are primarily antiseizure medications (e.g., gabapentinoids, sodium channel blockers) and antidepressant medications (e.g., tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors), though other medications and interventional pharmacologic therapies can also be considered. There are a wide variety of nonpharmacologic treatments for neuropathic pain including neuromodulation, nerve stimulation, physiotherapy, movement therapies, lifestyle modification, nutritional supplements, acupuncture, and mind-body techniques.

Pain management and social functioning limitations among adults with chronic pain by diabetes status: National Health Interview Survey, United States, 2019-2020

AIMS

This study aims to describe pain management technique usage and social functioning limitations among adults with chronic pain by diabetes status.

METHODS

The 2019 and 2020 National Health Interview Survey data were pooled to complete this analysis. Use of the following techniques in the past 3 months were measured: 1) prescription opioids; 2) physical, rehabilitative, or occupational therapy; 3) talk therapies; 4) chiropractic care; 5) yoga, Tai Chi, or Qi Gong; 6) massage; and 7) relaxation techniques. The social functioning limitations assessed were: 1) doing errands alone; 2) participating in social activities; and 3) work limitations. Weighted prevalence and 95 % confidence intervals (CIs) were estimated for each outcome by diabetes status. Logistic regression was used to estimate age- and sex-adjusted odds ratios (aORs) to assess differences by diabetes status.

RESULTS

Adults with diabetes and chronic pain were more likely to use prescription opioids (aOR: 1.4; 95 % CI: 1.2, 1.6) but less likely to use various nonpharmacological techniques than those without diabetes. Additionally, adults with diabetes and chronic pain were more likely to report each social functioning limitation than those without diabetes.

CONCLUSIONS

Results suggest adults with diabetes and chronic pain may be missing beneficial opportunities to manage pain.

12. Retinopathy, Neuropathy, and Foot Care: Standards of Care in Diabetes-2025

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Neurological manifestations of MGUS

Monoclonal gammopathy of undetermined significance (MGUS) is a highly prevalent disorder characterized by a small bone marrow plasma cell or lymphoplasmacytic clone (less than 10%) that produces a small amount of monoclonal paraprotein without associated organ damage. Most patients with MGUS display benign behavior indefinitely, but some progress to an overt malignancy, and others develop organ damage despite no increase in monoclonal protein, resulting in the so-called MG of clinical significance (MGCS). This concept includes different disorders depending on the organ involved, and among them, MG of neurological significance (MGNS) constitutes a real challenge from both a diagnostic and therapeutic point of view. Diagnosis is particularly difficult due to MGNS's heterogeneous clinical presentation and common lack of a diagnostic biopsy. On the other hand, the complexity of treatment lies in the lack of standardized regimens and the common irreversibility of neurological damage. Focusing on the neurological manifestations of MGUS affecting the peripheral nervous system, we describe 3 illustrative cases from daily practice and discuss different aspects of diagnosis to treatment, emphasizing the need for multidisciplinary management based on the close collaboration of neurologists and hematologists.

Advances of traditional Chinese medicine preclinical mechanisms and clinical studies on diabetic peripheral neuropathy

CONTEXT

Diabetic peripheral neuropathy (DPN) results in an enormous burden and reduces the quality of life for patients. Considering there is no specific drug for the management of DPN, traditional Chinese medicine (TCM) has increasingly drawn attention of clinicians and researchers around the world due to its characteristics of multiple targets, active components, and exemplary safety.

OBJECTIVE

To summarize the current status of TCM in the treatment of DPN and provide directions for novel drug development, the clinical effects and potential mechanisms of TCM used in treating DPN were comprehensively reviewed.

METHODS

Existing evidence on TCM interventions for DPN was screened from databases such as PubMed, the Cochrane Neuromuscular Disease Group Specialized Register (CENTRAL), and the Chinese National Knowledge Infrastructure Database (CNKI). The focus was on summarizing and analyzing representative preclinical and clinical TCM studies published before 2023.

RESULTS

This review identified the ameliorative effects of about 22 single herbal extracts, more than 30 herbal compound prescriptions, and four Chinese patent medicines on DPN in preclinical and clinical research. The latest advances in the mechanism highlight that TCM exerts its beneficial effects on DPN by inhibiting inflammation, oxidative stress and apoptosis, endoplasmic reticulum stress and improving mitochondrial function.

CONCLUSIONS

TCM has shown the power latent capacity in treating DPN. It is proposed that more large-scale and multi-center randomized controlled clinical trials and fundamental experiments should be conducted to further verify these findings.

Virtual Reality to Improve Sleep Quality in Patients Suffering from Painful Diabetic Polyneuropathy: A Proof of Concept Study

Background/Objectives: Sleep disturbance is often observed in the context of chronic pain. We hypothesize that, by providing an immersive Virtual Reality (VR) experience with a serious game to chronic pain patients an hour before bedtime, attention can be diverted from the pain condition, consequently leading to improved sleep quality. The aim is to evaluate the efficacy of VR compared to usual care in reducing the number of awakenings during the night and increasing sleep efficiency in patients suffering from painful diabetic polyneuropathy (PDPN). Methods: Eight patients with PDPN were randomized to either two weeks of VR or two weeks of usual care, followed by a cross-over. The primary outcome measurements were sleep efficiency and number of awakenings during the night. As secondary outcomes, self-reported sleep quality, insomnia, pain catastrophizing, anxiety, depression, pain intensity, side effects and impression of change were evaluated. Results: Data of seven patients were analysed. Actigraphy data, self-reported sleep quality, insomnia, pain catastrophizing, anxiety, depression and pain intensity scores did not differ between usual care and VR. As for impression of change, more patients improved after VR compared to usual care (V = 21, p = 0.03). Conclusions: A 2-week period of pain neuroscience education through VR did not result in increased sleep efficiency or fewer awakenings compared to usual care in patients with PDPN. These pilot results indicate that patients subjectively experience an improvement, yet this is not substantiated by either self-reported or objective measurements.

Acupuncture for the treatment of painful diabetic peripheral neuropathy: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

A growing number of studies have investigated the efficacy of acupuncture in the treatment of painful diabetic peripheral neuropathy (PDPN), but the findings of these studies have generated conflicting results. This study therefore aimed to assess the efficacy of acupuncture for treating PDPN so as to offer more conclusive results.

METHODS

Seven databases were systematically searched for studies published up until December 1, 2023. All randomized controlled trials (RCTs) of acupuncture for PDPN with visual analog scale (VAS) for pain score were included. Study selection, data extraction, and evaluation were conducted independently by researchers. The Risk of Bias 2 (RoB2) tool was employed to assess the risk of bias. From this sample, the mean difference (MD), 95 % confidence intervals (CI), publication bias, and heterogeneity were then computed.

RESULTS

The manual acupuncture group exhibited a significant decrease in the VAS for pain score compared with the routine care group (p < 0.0001; MD = -1.45 [95 % CI, -1.97 to -0.93], I2 = 84 %). The real acupuncture group demonstrated a greater reduction in VAS scores than the sham acupuncture group (p = 0.004; MD = -0.97 [95 % CI, -1.63 to -0.31], I2 = 65 %). Additionally, the acupuncture group showed improvements in sensory nerve conduction velocity (SNCV, p < 0.0001; MD = 2.29 [95 % CI, 1.79 to 2.78], I2 = 14 %) as well as motor nerve conduction velocity (MNCV, p < 0.0001; MD = 2.87 [95 % CI, 2.46 to 3.27], I2 = 0). Different durations of acupuncture treatment, including 6-10 weeks and 3-4 weeks, demonstrated a significant reduction in VAS scores compared with the routine care group.

CONCLUSION

This meta-analysis provides preliminary evidence for the claim that acupuncture has the potential to alleviate PDPN symptoms and improve SNCV and MNCV. However, high-quality RCTs are needed to offer further evidence and thus better substantiate such a contention.

Neuropathy of diabetes following initiation of a low-carbohydrate diet: Case report

Introduction

This case study portrays an unusual case of treatment-induced neuropathy of diabetes (TIND) in a patient with uncontrolled type 2 diabetes (T2D) who achieved rapid improvement in glucose control primarily with dietary intervention. Initial presentation was 50-year-old white male with a long-standing history of obesity and a family history of T2D with a screening glucose level >500mg/dL by glucometer, HbA1c of 14.9%, and initial weight 213 lbs.

Methods

The initial intervention included a low-carbohydrate diet, metformin, and a continuous glucose monitor (CGM). Semaglutide was added after seven days.

Results

His glycemia was within the target range within three weeks. Four weeks after initiation of therapy, he developed TIND symptoms consisting of burning, tightness, and numbness of bilateral feet along with 10/10 pain. At three months, his HbA1c dropped to 6.9% and his weight to 195 lbs. Treatment of his TIND reduced his pain from 10/10 to 2/10.

Conclusion

Whereas TIND is commonly associated with the use of insulin or sulfonylureas, this study adds evidence to the paucity of literature regarding TIND precipitated by dietary intervention.

Evaluation of tricyclic antidepressant deprescribing in the treatment of diabetic peripheral neuropathy within federally qualified health centers

BACKGROUND

Tricyclic antidepressants (TCAs) are a treatment option for diabetic peripheral neuropathy (DPN). Existing evidence demonstrates the prolonged use of TCA therapy increases the risk of cognitive decline and dementia, likely due to the anticholinergic effects of these medications. Anticholinergic activity is thought to contribute significantly to the observed increase in cognitive decline and dementia risks associated with long-term TCA use. There is little information available to describe the usage patterns of TCAs in DPN, particularly within underserved populations who receive care at federally qualified health centers.

OBJECTIVES

The objective of this study was to characterize (1) prescribing patterns of TCAs as a treatment for DPN and (2) evidence of deprescribing attempts in an FQHC population.

METHODS

A retrospective chart review of electronic medical record data for patients at 2 different FQHCs was performed. A convenience sample of 100 adults ≥ 18 years of age was stratified into 2 age groups, 18-55 years and 55+ years. All patients had a diagnosis of type 1 or type 2 diabetes mellitus and had been prescribed TCAs in the previous 4 years and had a visit with a primary care provider in the past 12 months.

RESULTS

The study population was comprised of 100 individuals. Seventy-four of 100 were persistent users of TCAs at the time of data collection, and the mean duration of utilization was 54.8 months. In total, 104 TCAs were prescribed across 100 individual patients. Of all 104 prescribed TCAs, 66 (63%) were prescribed at a rate that exceeded thresholds associated with a higher risk of dementia. Black older adults prescribed TCAs were more likely to exceed this dose threshold.

CONCLUSION

Sixty-five percent of patients used TCAs with a strength, frequency, and duration that exceeded risk thresholds for dementia in an older adult population. Interventions preventing use of or deprescribing TCAs in patients with DPN should be conducted for the potential benefits of preventing or delaying cognitive impairment and promoting equitable care.

Running Out of Breath: The Diminishing Role of Gabapentinoids in Epilepsy

Gabapentinoids and Risk for Severe Exacerbation in Chronic Obstructive Pulmonary Disease: A Population-Based Cohort Study Rahman AA, Dell’Aniello S, Moodie EEM, Durand M, Coulombe J, Boivin JF, Suissa S, Ernst P, Renoux C. Ann Intern Med. 2024;177(2):144-154. doi:10.7326/M23-0849 Background: North American and European health agencies recently warned of severe breathing problems associated with gabapentinoids, including in patients with chronic obstructive pulmonary disease (COPD), although supporting evidence is limited. Objective: To assess whether gabapentinoid use is associated with severe exacerbation in patients with COPD. Design: Time-conditional propensity score-matched, new-user cohort study. Setting: Health insurance databases from the Régie de l’assurance maladie du Québec in Canada. Patients: Within a base cohort of patients with COPD between 1994 and 2015, patients initiating gabapentinoid therapy with an indication (epilepsy, neuropathic pain, or other chronic pain) were matched 1:1 with nonusers on COPD duration, indication for gabapentinoids, age, sex, calendar year, and time-conditional propensity score. Measurements: The primary outcome was severe COPD exacerbation requiring hospitalization. Hazard ratios (HRs) associated with gabapentinoid use were estimated in subcohorts according to gabapentinoid indication and in the overall cohort. Results: The cohort included 356 gabapentinoid users with epilepsy, 9411 with neuropathic pain, and 3737 with other chronic pain, matched 1:1 to nonusers. Compared with nonuse, gabapentinoid use was associated with increased risk for severe COPD exacerbation across the indications of epilepsy (HR, 1.58 [95% CI, 1.08 to 2.30]), neuropathic pain (HR, 1.35 [CI, 1.24 to 1.48]), and other chronic pain (HR, 1.49 [CI, 1.27 to 1.73]) and overall (HR, 1.39 [CI, 1.29 to 1.50]). Limitation: Residual confounding, including from lack of smoking information. Conclusion: In patients with COPD, gabapentinoid use was associated with increased risk for severe exacerbation. This study supports the warnings from regulatory agencies and highlights the importance of considering this potential risk when prescribing gabapentin and pregabalin to patients with COPD.

Innate Immune Sensing of Adeno-Associated Virus Vectors

Adeno-associated virus (AAV) based viral vectors are widely used in human gene therapy and form the basis of approved treatments for several genetic diseases. Immune responses to vector and transgene products, however, substantially complicate these applications in clinical practice. The role of innate immune recognition of AAV vectors was initially unclear, given that inflammatory responses early after vector administration were typically mild in animal models. However, more recent research continues to identify innate immune pathways that are triggered by AAV vectors and that serve to provide activation signals for antigen-presenting cells and initiation of adaptive immune responses. Sensing of the AAV genome by the endosomal DNA receptor toll-like receptor 9 (TLR9) promotes early inflammatory response and interferon expression. Thus, activation of the TLR9>MyD88 pathway in plasmacytoid dendritic cells (pDCs) leads to the conditioning of antigen cross-presenting DCs through type I interferon (IFN-I) and ultimately CD8+ T cell activation. Alternatively, pDCs may also promote CD8+ T cell responses in a TLR9-independent manner by the production of IL-1 cytokines, thereby activating the IL-1R1>MyD88 signaling pathway. AAV can induce cytokine expression in monocyte-derived DCs, which in turn increases antibody formation. Binding of AAV capsid to complement components likely further elevates B cell activation. At high systemic vector doses in humans and in non-human primates, AAV vectors can trigger complement activation, with contributions by classical and alternative pathways, leading to severe toxicities. Finally, evidence for activation of TLR2 by the capsid and of additional innate receptors for nucleic acids has been presented. These observations show that AAV vectors can initiate several and likely redundant innate immune pathways resulting in an exaggerated adaptive immune response.

Pathology of pain and its implications for therapeutic interventions

Pain is estimated to affect more than 20% of the global population, imposing incalculable health and economic burdens. Effective pain management is crucial for individuals suffering from pain. However, the current methods for pain assessment and treatment fall short of clinical needs. Benefiting from advances in neuroscience and biotechnology, the neuronal circuits and molecular mechanisms critically involved in pain modulation have been elucidated. These research achievements have incited progress in identifying new diagnostic and therapeutic targets. In this review, we first introduce fundamental knowledge about pain, setting the stage for the subsequent contents. The review next delves into the molecular mechanisms underlying pain disorders, including gene mutation, epigenetic modification, posttranslational modification, inflammasome, signaling pathways and microbiota. To better present a comprehensive view of pain research, two prominent issues, sexual dimorphism and pain comorbidities, are discussed in detail based on current findings. The status quo of pain evaluation and manipulation is summarized. A series of improved and innovative pain management strategies, such as gene therapy, monoclonal antibody, brain-computer interface and microbial intervention, are making strides towards clinical application. We highlight existing limitations and future directions for enhancing the quality of preclinical and clinical research. Efforts to decipher the complexities of pain pathology will be instrumental in translating scientific discoveries into clinical practice, thereby improving pain management from bench to bedside.

Ranking Alpha Lipoic Acid and Gamma Linolenic Acid in Terms of Efficacy and Safety in the Management of Adults With Diabetic Peripheral Neuropathy: A Systematic Review and Network Meta-analysis

OBJECTIVES

Current medications for diabetic neuropathy (DN) recommended by the American Diabetes Association and American Academy of Neurology do not address the pathologic process of denervation among patients with DN, because ancillary treatments, such as reactive oxygen scavengers, may be needed. The purpose of this work was to summarize the available evidence about the efficacy and safety of alpha lipoic acid (ALA) and gamma linolenic acid (GLA) in the management of DN.

METHODS

Using the search terms [(alpha lipoic acid or ALA or thioctic acid or thioctacid) or (gamma linolenic acid or GLA)] AND [(diabetes or diabetes mellitus) AND (polyneuropathy or neuropathy or sensorimotor polyneuropathy or radiculopathy)], 11 studies were included in this review and combined meta-analysis.

RESULTS

Eight of the 11 articles (73%) reported significant benefit of ALA vs placebo. In the meta-analysis, the Total Symptom Score (TSS) for ALA 600 mg/day (ALA600) was 1.05 points lower (standard mean difference [SMD] -1.05, 95% confidence interval [CI] -2.07 to -0.04, p=0.04, I2=98.18%) compared with control at the end of the study. In the network meta-analysis, ALA600 (SMD -1.68, 95% CI -2.8 to -0.6) and GLA (SMD -2.39, 95% CI -4.3 to -0.5) had significantly lower TSSs compared with placebo. Moreover, GLA had the highest probability of being the best (52.7%) for improving DN symptoms. In all studies, most adverse events include gastrointestinal disturbances. In terms of tolerability, no differences were detected between ALA and control groups.

CONCLUSION

ALA and GLA appear to be safe and efficacious biofactors for improvement of DN symptoms.

Peripheral Neuropathy

Peripheral neuropathy is a commonly encountered diagnosis in both neurology and primary care office settings. It is important for primary care providers to identify, characterize, and diagnose patients with neuropathy. This study aims to describe the clinical presentation, diagnostic work up, and treatment options for this entity, as well as the identification of atypical features that should prompt specialized laboratory testing, electrodiagnostic testing, and neurologic consultation.

Prevalence and Risk Factors of Distal Symmetric Polyneuropathy Among Predominantly Non-Hispanic Black, Low-Income Patients

BACKGROUND AND OBJECTIVES

Distal symmetric polyneuropathy (DSP) is a disabling, often painful condition associated with falls and reduced quality of life. Non-Hispanic Black people and people with low income are underrepresented in existing DSP studies; therefore, it is unknown whether data accurately reflect the prevalence, risk factors, and burden of disease in these populations.

METHODS

Patients older than 40 years presenting to an outpatient internal medicine clinic predominantly serving Medicaid patients in Flint, Michigan, were enrolled in a cross-sectional study. Demographics, clinical characteristics, including medication use, anthropomorphic measurements, fasting lipids, and hemoglobin A1c were collected. DSP was defined using the modified Toronto Clinical Neuropathy Score (mTCNS). Multivariable logistic regression was performed to model DSP and undiagnosed DSP as a function of potential risk factors age, metabolic syndrome, and race. DSP burden was measured using Peripheral Neuropathy Quality of Life Instrument-97.

RESULTS

Two hundred participants were enrolled, and 169 (85%) completed all data collection. The population was 55% female of mean age (SD) 58.2 years (10.4) and 69% non-Hispanic Black. Among the population, 50% had diabetes, 67% had metabolic syndrome, and 47% had a household income <$20,000. DSP was present in 73% of the population, of which 75% were previously undiagnosed. Neuropathic pain was documented in 57% of participants with DSP. DSP based on mTCNS criteria was associated with older age (odds ratio [OR] 1.1 [95% confidence interval (CI) 1.03-1.2]) and metabolic syndrome (OR 4.4 [1.1-18.1]). Non-Hispanic Black participants had lower odds of DSP (OR 0.1 [0.01-0.4]) than non-Hispanic White and Hispanic participants. DSP burden was high, including increased pain, health-related worry, and poorer quality of life (all p < 0.001).

DISCUSSION

DSP is extremely common and often underrecognized in this predominantly non-Hispanic Black, low-income population and leads to substantial disease burden. Metabolic syndrome is a highly prevalent, modifiable risk factor in this population that should be managed to lower DSP prevalence.

A Systematic Guideline by the ASPN Workgroup on the Evidence, Education, and Treatment Algorithm for Painful Diabetic Neuropathy: SWEET

Introduction

Painful diabetic neuropathy (PDN) is a leading cause of pain and disability globally with a lack of consensus on the appropriate treatment of those suffering from this condition. Recent advancements in both pharmacotherapy and interventional approaches have broadened the treatment options for PDN. There exists a need for a comprehensive guideline for the safe and effective treatment of patients suffering from PDN.

Objective

The SWEET Guideline was developed to provide clinicians with the most comprehensive guideline for the safe and appropriate treatment of patients suffering from PDN.

Methods

The American Society of Pain and Neuroscience (ASPN) identified an educational need for a comprehensive clinical guideline to provide evidence-based recommendations for PDN. A multidisciplinary group of international experts developed the SWEET guideline. The world literature in English was searched using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Meeting Abstracts, and Scopus to identify and compile the evidence for diabetic neuropathy pain treatments (per section as listed in the manuscript) for the treatment of pain. Manuscripts from 2000-present were included in the search process.

Results

After a comprehensive review and analysis of the available evidence, the ASPN SWEET guideline was able to rate the literature and provide therapy grades for most available treatments for PDN utilizing the United States Preventive Services Task Force criteria.

Conclusion

The ASPN SWEET Guideline represents the most comprehensive review of the available treatments for PDN and their appropriate and safe utilization.

Painful diabetic neuropathy: The role of ion channels

Painful diabetic neuropathy (PDN) is a common chronic complication of diabetes that causes neuropathic pain and negatively affects the quality of life. The management of PDN is far from satisfactory. At present, interventions are primarily focused on symptomatic treatment. Ion channel disorders are a major cause of PDN, and a complete understanding of their roles and mechanisms may provide better options for the clinical treatment of PDN. Therefore, this review summarizes the important role of ion channels in PDN and the current drug development targeting these ion channels.

Pain in the Context of Sensory Deafferentation

Pain that accompanies deafferentation is one of the most mysterious and misunderstood medical conditions. Prevalence rates for the assorted conditions vary considerably but the most reliable estimates are greater than 50% for strokes involving the somatosensory system, brachial plexus avulsions, spinal cord injury, and limb amputation, with controversy surrounding the mechanistic contributions of deafferentation to ensuing neuropathic pain syndromes. Deafferentation pain has also been described for loss of other body parts (e.g., eyes and breasts) and may contribute to between 10% and upwards of 30% of neuropathic symptoms in peripheral neuropathies. There is no pathognomonic test or sign to identify deafferentation pain, and part of the controversy surrounding it stems from the prodigious challenges in differentiating cause and effect. For example, it is unknown whether cortical reorganization causes pain or is a byproduct of pathoanatomical changes accompanying injury, including pain. Similarly, ascertaining whether deafferentation contributes to neuropathic pain, or whether concomitant injury to nerve fibers transmitting pain and touch sensation leads to a deafferentation-like phenotype can be clinically difficult, although a detailed neurologic examination, functional imaging, and psychophysical tests may provide clues. Due in part to the concurrent morbidities, the physical, psychologic, and by extension socioeconomic costs of disorders associated with deafferentation are higher than for other chronic pain conditions. Treatment is symptom-based, with evidence supporting first-line antineuropathic medications such as gabapentinoids and antidepressants. Studies examining noninvasive neuromodulation and virtual reality have yielded mixed results.

Diabetic Sensorimotor Polyneuropathy: An Overview on Epidemiology, Risk Factors, Classification, Diagnosis, and Treatment

Diabetic distal symmetric sensorimotor polyneuropathy (DSPN) is a common complication of diabetes with devastating consequences. Hyperglycaemia is the major aetiological factor, while emerging data demonstrate that cardiometabolic risk factors also contribute to its development. Diagnosis of DSPN involves interview of medical and neurological history, foot inspection, and sensory and motor function examination with specific tests such as temperature and pinprick perception for small nerve fibers, and vibration and light touch assessments for large nerve fibers. Management includes optimised glycaemic control, treatment of cardiovascular risk factors, and symptomatic treatment aiming at improving life quality. This article provides an overview on epidemiology, risk factors, classification, diagnosis and current treatment of DSPN.

Update on Treating Painful Diabetic Peripheral Neuropathy: A Review of Current US Guidelines with a Focus on the Most Recently Approved Management Options

Painful diabetic peripheral neuropathy (DPN) is a highly prevalent and disabling complication of diabetes that is often misdiagnosed and undertreated. The management of painful DPN involves treating its underlying cause via lifestyle modifications and intensive glucose control, targeting its pathogenesis, and providing symptomatic pain relief, thereby improving patient function and health-related quality of life. Four pharmacologic options are currently approved by the US Food and Drug Administration (FDA) to treat painful DPN. These include three oral medications (duloxetine, pregabalin, and tapentadol extended release) and one topical agent (capsaicin 8% topical system). More recently, the FDA approved several spinal cord stimulation (SCS) devices to treat refractory painful DPN. Although not FDA-approved specifically to treat painful DPN, tricyclic antidepressants, serotonin/norepinephrine reuptake inhibitors, gabapentinoids, and sodium channel blockers are common first-line oral options in clinical practice. Other strategies may be used as part of individualized comprehensive pain management plans. This article provides an overview of the most recent US guidelines for managing painful DPN, with a focus on the two most recently approved treatment options (SCS and capsaicin 8% topical system), as well as evidence for using FDA-approved and guideline-supported drugs and devices. Also discussed are unmet needs for this patient population, and evidence for potential future treatments for painful DPN, including drugs with novel mechanisms of action, electrical stimulation devices, and nutraceuticals.

Gabapentinoids and Risk for Severe Exacerbation in Chronic Obstructive Pulmonary Disease : A Population-Based Cohort Study

BACKGROUND

North American and European health agencies recently warned of severe breathing problems associated with gabapentinoids, including in patients with chronic obstructive pulmonary disease (COPD), although supporting evidence is limited.

OBJECTIVE

To assess whether gabapentinoid use is associated with severe exacerbation in patients with COPD.

DESIGN

Time-conditional propensity score-matched, new-user cohort study.

SETTING

Health insurance databases from the Régie de l'assurance maladie du Québec in Canada.

PATIENTS

Within a base cohort of patients with COPD between 1994 and 2015, patients initiating gabapentinoid therapy with an indication (epilepsy, neuropathic pain, or other chronic pain) were matched 1:1 with nonusers on COPD duration, indication for gabapentinoids, age, sex, calendar year, and time-conditional propensity score.

MEASUREMENTS

The primary outcome was severe COPD exacerbation requiring hospitalization. Hazard ratios (HRs) associated with gabapentinoid use were estimated in subcohorts according to gabapentinoid indication and in the overall cohort.

RESULTS

The cohort included 356 gabapentinoid users with epilepsy, 9411 with neuropathic pain, and 3737 with other chronic pain, matched 1:1 to nonusers. Compared with nonuse, gabapentinoid use was associated with increased risk for severe COPD exacerbation across the indications of epilepsy (HR, 1.58 [95% CI, 1.08 to 2.30]), neuropathic pain (HR, 1.35 [CI, 1.24 to 1.48]), and other chronic pain (HR, 1.49 [CI, 1.27 to 1.73]) and overall (HR, 1.39 [CI, 1.29 to 1.50]).

LIMITATION

Residual confounding, including from lack of smoking information.

CONCLUSION

In patients with COPD, gabapentinoid use was associated with increased risk for severe exacerbation. This study supports the warnings from regulatory agencies and highlights the importance of considering this potential risk when prescribing gabapentin and pregabalin to patients with COPD.

PRIMARY FUNDING SOURCE

Canadian Institutes of Health Research and Canadian Lung Association.

Guideline for the Management of Diabetes Mellitus in the Elderly in China (2024 Edition)

With the deepening of aging in China, the prevalence of diabetes in older people has increased noticeably, and standardized diabetes management is critical for improving clinical outcomes of diabetes in older people. In 2021, the National Center of Gerontology, Chinese Society of Geriatrics, and Diabetes Professional Committee of Chinese Aging Well Association organized experts to write the first guideline for diabetes diagnosis and treatment in older people in China, the Guideline for the Management of Diabetes Mellitus in the Elderly in China (2021 Edition). The guideline emphasizes that older patients with diabetes are a highly heterogeneous group requiring comprehensive assessment and stratified and individualized management strategies. The guideline proposes simple treatments and de-intensified treatment strategies for older patients with diabetes. This edition of the guideline provides clinicians with practical and operable clinical guidance, thus greatly contributing to the comprehensive and full-cycle standardized management of older patients with diabetes in China and promoting the extensive development of clinical and basic research on diabetes in older people and related fields. In the past 3 years, evidence-based medicine for older patients with diabetes and related fields has further advanced, and new treatment concepts, drugs, and technologies have been developed. The guideline editorial committee promptly updated the first edition of the guideline and compiled the Guideline for the Management of Diabetes Mellitus in the Elderly in China (2024 Edition). More precise management paths for older patients with diabetes are proposed, for achieving continued standardization of the management of older Chinese patients with diabetes and improving their clinical outcomes.

Perineural injections of incobotulinumtoxin-A for diabetic neuropathic pain of the lower extremities: protocol for a phase II, single-centre, double-blind, randomised, placebo-controlled trial (the PINBOT study)

INTRODUCTION

Diabetic neuropathic pain (DNP) is a debilitating complication affecting 15-20% of people with diabetes and is a predictor of depression, poor sleep and decreased quality of life. Current pharmacological treatments are often insufficient and have significant side-effects. Subcutaneous or intradermal botulinumtoxin-A (BonT-A) is an effective and safe treatment for neuropathic pain but is limited by the need to cover the entire affected area with injections. For large cutaneous areas, infiltration of the sensory nerve supply with BonT-A could provide similar effects, with a single injection. We aim to investigate the safety, efficacy, and effects on quality of life, physical activity, depressive symptoms and activities of daily living of perineural injections of BonT-A in patients with DNP of both lower extremities.

METHODS

This study is a double-blind, randomised, placebo-controlled clinical trial. 80 participants with moderate to severe DNP of both legs will be randomised 1:1 to receive injections of either 100 units incobotulinumtoxin-A or a saline placebo around each distal sciatic nerve for two cycles of 12 weeks. Average daily pain scores will be recorded once a day from 1 week prior to the first treatment and through the entire study period. Primary outcomes are differences between groups in daily and weekly mean pain scores. Secondary outcomes are levels of physical activity, depression scores, health-related quality of life, activities of daily living, sensory profiles and motor function, recorded at baseline, 4, 12, 16 and 24 weeks. The use of rescue medication and adverse events will be recorded throughout the study period.

ETHICS AND DISSEMINATION

The study is approved by the Danish Committee on Health Research Ethics and the Danish Medicines Agency. EU-Clinical Trial Information System (EU: 2022-500727-68-01), clinicaltrials.gov (ID: NCT05623111). Results will be published in peer-reviewed journals in open-access formats and data made available in anonymised form.

TRIAL REGISTRATION NUMBER

NCT05623111.

Alpha-lipoic acid for diabetic peripheral neuropathy

BACKGROUND

Diabetic peripheral neuropathy (DPN) is a frequent complication in people living with type 1 or type 2 diabetes. There is currently no effective treatment for DPN. Although alpha-lipoic acid (ALA, also known as thioctic acid) is widely used, there is no consensus about its benefits and harms.

OBJECTIVES

To assess the effects of alpha-lipoic acid as a disease-modifying agent in people with diabetic peripheral neuropathy.

SEARCH METHODS

On 11 September 2022, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, and two clinical trials registers. We also searched the reference lists of the included studies and relevant review articles for additional references not identified by the electronic searches.

SELECTION CRITERIA

We included randomised clinical trials (RCTs) that compared ALA with placebo in adults (aged 18 years or older) and that applied the study interventions for at least six months. There were no language restrictions.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane. The primary outcome was change in neuropathy symptoms expressed as changes in the Total Symptom Score (TSS) at six months after randomisation. Secondary outcomes were change in neuropathy symptoms at six to 12 months and at 12 to 24 months, change in impairment, change in any validated quality of life total score, complications of DPN, and adverse events. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

Our analysis incorporated three trials involving 816 participants. Two studies included people with type 1 or type 2 diabetes, while one study included only people with type 2 diabetes. The duration of treatment was between six months and 48 months. We judged all studies at high risk of overall bias due to attrition. ALA compared with placebo probably has little or no effect on neuropathy symptoms measured by TSS (lower score is better) after six months (mean difference (MD) -0.16 points, 95% confidence interval (CI) -0.83 to 0.51; 1 study, 330 participants; moderate-certainty evidence). The CI of this effect estimate did not contain the minimal clinically important difference (MCID) of 0.97 points. ALA compared with placebo may have little or no effect on impairment measured by the Neuropathy Impairment Score-Lower Limbs (NIS-LL; lower score is better) after six months (MD -1.02 points, 95% CI -2.93 to 0.89; 1 study, 245 participants; low-certainty evidence). However, we cannot rule out a significant benefit, because the lower limit of the CI surpassed the MCID of 2 points. There is probably little or no difference between ALA and placebo in terms of adverse events leading to cessation of treatment within six months (risk ratio (RR) 1.48, 95% CI 0.50 to 4.35; 3 studies, 1090 participants; moderate-certainty evidence). No studies reported quality of life or complications associated with DPN.

AUTHORS' CONCLUSIONS

Our analysis suggests that ALA probably has little or no effect on neuropathy symptoms or adverse events at six months, and may have little or no effect on impairment at six months. All the studies were at high risk of attrition bias. Therefore, future RCTs should ensure complete follow-up and transparent reporting of any participants missing from the analyses.

Placebo and nocebo responses in painful diabetic neuropathy: systematic review and meta-analysis

ABSTRACT

This preregistered (CRD42021223379) systematic review and meta-analysis aimed to characterize the placebo and nocebo responses in placebo-controlled randomized clinical trials (RCTs) on painful diabetic neuropathy (PDN), updating the previous literature by a decade. Four databases were searched for PDN trials published in the past 20 years, testing oral medications, adopting a parallel-group design. Magnitude of placebo or nocebo responses, Cochrane risk of bias, heterogeneity, and moderators were evaluated. Searches identified 21 studies (2425 placebo-treated patients). The overall mean pooled placebo response was -1.54 change in the pain intensity from baseline [95% confidence interval (CI): -1.52, -1.56, I 2 = 72], with a moderate effect size (Cohen d = 0.72). The pooled placebo 50% response rate was 25% [95% CI: 22, 29, I 2 = 50%]. The overall percentage of patients with adverse events (AEs) in the placebo arms was 53.3% [95% CI: 50.9, 55.7], with 5.1% [95% CI: 4.2, 6] of patients dropping out due to AEs. The year of study initiation was the only significant moderator of placebo response (regression coefficient = -0.06, [95% CI: -0.10, -0.02, P = 0.007]). More recent RCTs tended to be longer, bigger, and to include older patients (N = 21, rs = 0.455, P = 0.038, rs = 0.600, P = 0.004, rs = 0.472, P = 0.031, respectively). Our findings confirm the magnitude of placebo and nocebo responses, identify the year of study initiation as the only significant moderator of placebo response, draw attention to contextual factors such as confidence in PDN treatments, patients' previous negative experiences, intervention duration, and information provided to patients before enrollment.

Psychosocial Care for People With Diabetic Neuropathy: Time for Action

Psychological factors and psychosocial care for individuals with diabetic neuropathy (DN), a common and burdensome complication of diabetes, are important but overlooked areas. In this article we focus on common clinical manifestations of DN, unremitting neuropathic pain, postural instability, and foot complications, and their psychosocial impact, including depression, anxiety, poor sleep quality, and specific problems such as fear of falling and fear of amputation. We also summarize the evidence regarding the negative impact of psychological factors such as depression on DN, self-care tasks, and future health outcomes. The clinical problem of underdetection and undertreatment of psychological problems is described, together with the value of using brief assessments of these in clinical care. We conclude by discussing trial evidence regarding the effectiveness of current pharmacological and nonpharmacological approaches and also future directions for developing and testing new psychological treatments for DN and its clinical manifestations.

12. Retinopathy, Neuropathy, and Foot Care: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

A phase I study to evaluate the safety, tolerability, and pharmacokinetics of a novel, potent GABA analog HSK16149 in healthy Chinese subjects

Purpose: HSK16149 is a novel, potent gamma-aminobutyric acid (GABA) analog for the treatment of neuropathic pain. This study aimed to evaluate the safety, tolerability, and pharmacokinetics of HSK16149 after single and multiple doses in healthy Chinese subjects. Methods: The randomized, double-blind, placebo-controlled study comprised two parts: SAD (single ascending-dose study) and MAD (multiple ascending-dose study). A total of 122 healthy subjects were enrolled in this study. HSK16149 capsule or placebo was administered as the protocol required. The safety of the drug was evaluated through clinical examinations and adverse events. Blood and urine samples were collected at the designated time intervals for pharmacokinetic analysis. Results: Subjects were generally well tolerated after HSK16149 administration and the most common treatment-emergent adverse event (TEAEs) was dizziness, which was expected based on the mechanism of action of HSK16149. In SAD, AUC and Cmax were shown to have a dose-proportional relationship in the dose range of 5-120 mg. The t1/2 of HSK16149 is 3.7-6.4 h. In MAD, after a single and multiple administration of 15-80 mg, AUC and Cmax are proportional to the increased dose of HSK16149, and the accumulative ratios of AUC and Cmax at steady-state were 1.05-1.44 and 1.07-1.36, respectively, indicating that HSK16149 only accumulated slightly after repeated administration. Conclusion: HSK16149 was well tolerated in healthy Chinese subjects. Based on the safety and pharmacokinetic data, 80 mg twice daily (BID) was suggested as the highest target dose for further clinical development. Clinical Trial Registration: http://www.chinadrugtrials.org.cn, identifier CTR20182535 and CTR20191317.

Advances in diagnosis and management of distal sensory polyneuropathies

Distal sensory polyneuropathy (DSP) is characterised by length-dependent, sensory-predominant symptoms and signs, including potentially disabling symmetric chronic pain, tingling and poor balance. Some patients also have or develop dysautonomia or motor involvement depending on whether large myelinated or small fibres are predominantly affected. Although highly prevalent, diagnosis and management can be challenging. While classic diabetes and toxic causes are well-recognised, there are increasingly diverse associations, including with dysimmune, rheumatological and neurodegenerative conditions. Approximately half of cases are initially considered idiopathic despite thorough evaluation, but often, the causes emerge later as new symptoms develop or testing advances, for instance with genetic approaches. Improving and standardising DSP metrics, as already accomplished for motor neuropathies, would permit in-clinic longitudinal tracking of natural history and treatment responses. Standardising phenotyping could advance research and facilitate trials of potential therapies, which lag so far. This review updates on recent advances and summarises current evidence for specific treatments.

Conventional management and current guidelines for painful diabetic neuropathy

Painful Diabetic Peripheral Neuropathy (PDN) is common, affecting around a quarter of patients with both type 1 and type 2 diabetes, and can lead to significant curtailment of functionality and quality of life. Patients may present with unremitting burning, aching or "electric-shock" type pains in their feet, legs and later, in the hands. Conventional management approaches must focus not only on pain relief, but also on concurrent sleep problems, mood disorders and functionality. The mainstay of treatment is pharmacotherapy. Most current international guidelines recommend a choice of four drugs: amitriptyline, duloxetine, pregabalin or gabapentin, as initial treatment for PDN. Recent evidence from the OPTION-DM trial demonstrated that these drugs and their combinations have equivalent efficacy. Moreover, combination treatment provided significant pain relief to patients with inadequate response to the maximum tolerated dose of monotherapy. PDN refractory to pharmacotherapy can be treated with capsaicin 8% or high frequency spinal cord stimulation.

Monotherapy Versus Combination Therapy in the Treatment of Painful Diabetic Neuropathy: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Painful peripheral neuropathy is a common and challenging complication of diabetes mellitus. Combination therapy is used widely by clinicians, although strong evidence for efficacy and safety is lacking. The goal of this study is to compare the efficacy and safety of combination versus monotherapy of first-line medications for peripheral diabetic neuropathy.

METHODS

PubMed, Embase, Cochrane Central, and clinicaltrials.gov databases were searched on December 5, 2022, for randomized clinical trials comparing combined therapy with gabapentinoids and either tricyclic antidepressants (TCAs) or serotonin and norepinephrine reuptake inhibitors (SNRIs) versus monotherapy with any of these drugs. Pooled mean differences (MD) with a 95% confidence interval (CI) were computed for pain outcomes, measured on an 11-point numeric rating scale averaging pain scores in the last 7 days. Risk ratios (RRs) were computed for binary endpoints. Risk assessment was performed using the Risk of Bias 2 tool.

RESULTS

A total of five randomized studies and 916 patients were included. Follow-up ranged from 6 to 12 weeks. Mean pain reduction was greater for combination therapy than monotherapy (MD - 0.39; 95% CI - 0.67 to - 0.12; p = 0.005). Similarly, there was an improvement in ≥ 30% reduction in average pain (RR 1.16; 95% CI 1.07-1.26; p < 0.01) with combination therapy. In contrast, there was no significant difference between groups in ≥ 50% reduction in average pain (RR 1.21; 95% CI 0.99-1.49; p = 0.06). When comparing combination therapy versus gabapentinoid monotherapy, there was also a significant reduction in average pain (MD - 0.61; 95% CI - 0.85 to - 0.37; p < 0.01) with combination therapy.

CONCLUSION

In patients with painful diabetic peripheral neuropathy, the combination of gabapentinoids with TCAs or SNRIs is associated with a greater reduction in pain as compared with monotherapy, although this difference may not translate into a clinically important difference.

Prescription Opioid Initiation for Neuropathy, Headache, and Low Back Pain: A US Population-based Medicare Study

Neuropathy, headache, and low back pain (LBP) are common conditions requiring pain management. Yet little is known regarding whether access to specialists impacts opioid prescribing. We aimed to identify factors associated with opioid initiation among opioid-naïve older adults and evaluate how access to particular specialists impacts prescribing. This retrospective cohort study used a 20% Medicare sample from 2010 to 2017. Opioid initiation was defined as a first opioid prescription filled within 12 months after a diagnosis encounter. Disease-related opioid initiation was defined as a first opioid prescription filled within 7 days following a disease-specific claim. Logistic regression using generalized estimating equations was used to determine the association of patient demographics, provider types, and regional physician specialty density with disease-related opioid initiation, accounting for within-region correlation. We found opioid initiation steadily declined from 2010 to 2017 (neuropathy: 26-19%, headache: 31-20%, LBP: 45-32%), as did disease-related opioid initiation (4-3%, 12-7%, 29-19%) and 5 to 10% of initial disease-related prescriptions resulted in chronic opioid use within 12 months of initiation. Certain specialist visits were associated with a lower likelihood of disease-related opioid initiation compared with primary care. Residence in high neurologist density regions had a lower likelihood of disease-related opioid initiation (headache odds ratio [OR] .76 [95% CI: .63-.92]) and LBP (OR .7 [95% CI: .61-.81]) and high podiatrist density regions for neuropathy (OR .56 [95% CI: .41-.78]). We found that specialist visits and greater access to specialists were associated with a lower likelihood of disease-related opioid initiation. These data could inform strategies to perpetuate reductions in opioid use for these common pain conditions. PERSPECTIVE: This article presents how opioid initiation for opioid-naïve patients with newly diagnosed neuropathy, headache, and LBP varies across providers. Greater access to certain specialists decreased the likelihood of opioid initiation. Future work may consider interventions to support alternative treatments and better access to specialists in low-density regions.

Where does spinal cord stimulation fit into the international guidelines for refractory painful diabetic neuropathy? a consensus statement

BACKGROUND

Although pharmacotherapy with anticonvulsants and/or antidepressants can be effective for many people with painful diabetic neuropathy (PDN), albeit with frequent side-effects, a critical juncture occurs when neuropathic pain no longer responds to standard first- and second-step mono- and dual therapy and becomes refractory. Subsequent to these pharmacotherapeutic approaches, third-line treatment options for PDN may include opioids (short-term), capsaicin 8% patches, and spinal cord stimulation (SCS).

AIM

This document summarizes consensus recommendations regarding appropriate treatment for refractory peripheral diabetic neuropathy (PDN), based on outcomes from an expert panel convened on December 10, 2022, as part of the Worldwide Initiative for Diabetes Education Virtual Global Summit, "Advances in the Management of Painful Diabetic Neuropathy."

PARTICIPANTS

Nine attendees, eminent physicians and academics, comprising six diabetes specialists, two pain specialists, and one health services expert.

EVIDENCE

For individuals with refractory PDN, opioids are a high-risk option that do not provide a long-term solution and should not be used. For appropriately selected individuals, SCS is an effective, safe, and durable treatment option. In particular, high-frequency (HF) SCS (10 kHz) shows strong efficacy and improves quality of life. To ensure treatment success, strict screening criteria should be used to prioritize candidates for SCS.

CONSENSUS PROCESS

Each participant voiced their opinion after reviewing available data, and a verbal consensus was reached during the meeting.

CONCLUSION

Globally, the use of opioids should rarely be recommended for refractory, severe PDN. Based on increasing clinical evidence, SCS, especially HF-SCS, should be considered as a treatment for PDN that is not responsive to first- or second-line monotherapy/dual therapy.

The lived experience of patients with breast cancer on adjuvant endocrine therapy: side effects and coping strategies during the first year of medication initiation

PURPOSE

Adjuvant endocrine therapy (AET) is pivotal for hormone receptor-positive breast cancer patients, significantly enhancing survival rates. Yet, adherence to AET remains challenging due to side effects. This study delves into the lived experience of breast cancer survivors concerning AET-induced side effects and examines differences in symptom profiles between Tamoxifen and aromatase inhibitors (AIs).

METHODS

We interviewed 35 breast cancer survivors on AET, conducting qualitative iterative analysis using grounded theory. A codebook was developed to aid data coding and interpretation. NVIVO software facilitated comprehensive transcript analysis.

RESULTS

Survivors reported a spectrum of side effects like hot flashes, sexual issues, joint pain, stiffness, mood swings, and fertility concerns. Symptom profiles differed based on AET type. Tamoxifen users experienced more frequent sexual side effects and mood swings, while AIs were linked to joint pain, stiffness, and bone health worries. Those on AET for over 6 months expressed heightened concerns about side effects.

CONCLUSION

Tailored patient education, aligned with AET type, empowers survivors to manage side effects using self-regulatory strategies. Acknowledging distinct symptom profiles enables informed decisions, improving adherence and quality of life.

IMPLICATIONS

This study underscores tailored survivorship support, equipping patients with tools to manage side effects, enhancing adherence, and long-term outcomes. The findings inform the integration of comprehensive survivorship programs, emphasizing individualized strategies for managing side effects and promoting better adherence and improved quality of life.

Treatment-induced neuropathy of diabetes: challenges in diagnosing neuropathic pain, value of sudomotor function testing

A patient in his 60s was admitted for an extensive neurological work-up due to progressive asymmetrical, distally pronounced pain in both feet and legs. Conventional pain relievers did not help in pain reduction. A Sudoscan revealed small fibre damage in all extremities indicating an underlying neuropathy. The patient had started insulin treatment around 6 months prior to hospitalisation because of a newly diagnosed late-onset diabetes. Due to a rapid drop in glycated haemoglobin (from over 14% to 6% in 4 months), treatment-induced neuropathy of diabetes (TIND) was hypothesised. On increasing the dose of pregabalin and adding duloxetine, the patient reported improvement of symptoms, which further underlined the suspected diagnosis. Hence, in patients with severe hyperglycaemia, changes in glycaemic control should be stepwise and not rapid; however, to date, no guidelines exist how to avoid TIND.

Evaluation and treatment approaches for neurological post-acute sequelae of COVID-19: A consensus statement and scoping review from the global COVID-19 neuro research coalition

Post-acute neurological sequelae of COVID-19 affect millions of people worldwide, yet little data is available to guide treatment strategies for the most common symptoms. We conducted a scoping review of PubMed/Medline from 1/1/2020-4/1/2023 to identify studies addressing diagnosis and treatment of the most common post-acute neurological sequelae of COVID-19 including: cognitive impairment, sleep disorders, headache, dizziness/lightheadedness, fatigue, weakness, numbness/pain, anxiety, depression and post-traumatic stress disorder. Utilizing the available literature and international disease-specific society guidelines, we constructed symptom-based differential diagnoses, evaluation and management paradigms. This pragmatic, evidence-based consensus document may serve as a guide for a holistic approach to post-COVID neurological care and will complement future clinical trials by outlining best practices in the evaluation and treatment of post-acute neurological signs/symptoms.

Pharmacological and Nonpharmacological Treatments for Painful Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is one of the most prevalent chronic complications of diabetes. The lifetime prevalence of DPN is thought to be >50%, and 15%-25% of patients with diabetes experience neuropathic pain, referred to as "painful DPN." Appropriate treatment of painful DPN is important because this pain contributes to a poor quality of life by causing sleep disturbance, anxiety, and depression. The basic principle for the management of painful DPN is to control hyperglycemia and other modifiable risk factors, but these may be insufficient for preventing or improving DPN. Because there is no promising diseasemodifying medication for DPN, the pain itself needs to be managed when treating painful DPN. Drugs for neuropathic pain, such as gabapentinoids, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, alpha-lipoic acid, sodium channel blockers, and topical capsaicin, are used for the management of painful DPN. The U.S. Food and Drug Administration (FDA) has approved pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch as drugs for the treatment of painful DPN. Recently, spinal cord stimulation using electrical stimulation is approved by the FDA for the treatment for painful DPN. This review describes the currently available pharmacological and nonpharmacological treatments for painful DPN.

Treatment‐induced neuropathy of diabetes: an update

Background and aims: Treatment‐induced neuropathy of diabetes is an acute small‐fibre neuropathy associated with rapid glycaemia improvement.

Methods: This study is a narrative review carried out based on a bibliographic review, using articles indexed in PubMed/Medline and Scielo.

Results: This entity is more frequent in adult patients with poor previous glycaemic control. Its precise pathophysiology is unknown, but it is likely related to unrestored microcirculation changes that occurred during the hyperglycaemic period. It presents with intense, sudden neuropathic pain and autonomic dysfunction after a rapid glycaemic correction and a poorer analgesic response than in diabetic neuropathy.

Conclusions: Since rapid glycaemia correction is the cause of this problem, clinical practice guidelines that can help physicians to prevent, diagnose and manage this entity should be developed. Copyright © 2023 John Wiley & Sons.