Quality of Life in Painful Peripheral Neuropathies: A Systematic Review

Interleukin-35 alleviates neuropathic pain and induces an anti-inflammatory shift in spinal microglia in nerve-injured male mice

Immune cells are critical in promoting neuroinflammation and neuropathic pain and in facilitating pain resolution, depending on their inflammatory and immunoregulatory cytokine response. Interleukin (IL)-35, secreted by regulatory immune cells, is a member of the IL-12 family with a potent immunosuppressive function. In this study, we investigated the effects of IL-35 on pain behaviors, spinal microglia phenotype following peripheral nerve injury, and in vitro microglial cultures in male and female mice. Intrathecal recombinant IL-35 treatment alleviated mechanical pain hypersensitivity prominently in male mice, with only a modest effect in female mice after sciatic nerve chronic constriction injury (CCI). IL-35 treatment resulted in sex-specific microglial changes following CCI, reducing inflammatory microglial markers and upregulating anti-inflammatory markers in male mice. Spatial transcriptomic analysis revealed that IL-35 suppressed microglial complement activation in the superficial dorsal horn in male mice after CCI. Moreover, in vitro studies showed that IL-35 treatment of cultured inflammatory microglia mitigated their hypertrophied morphology, increased their cell motility, and decreased their phagocytic activity, indicating a phenotypic shift towards homeostatic microglia. Further, IL-35 altered microglial cytokines/chemokines in vitro, suppressing the release of IL-9 and monocyte-chemoattractant protein-1 and increasing IL-10 in the supernatant of male microglial cultures. Our findings indicate that treatment with IL-35 modulates spinal microglia and alleviates neuropathic pain in male mice, suggesting IL-35 as a potential sex-specific targeted immunomodulatory treatment for neuropathic pain.

A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled 14-Week Study of Mirogabalin in Chinese Patients with Diabetic Peripheral Neuropathic Pain

INTRODUCTION

There is no approved effective drug for diabetic peripheral neuropathic pain (DPNP) in China. Gabapentinoids including mirogabalin have shown promise, although data in Chinese patients are scarce.

METHODS

This phase 3, multicenter, randomized, double-blind, placebo-controlled trial investigated the efficacy and safety of mirogabalin for treating DPNP in China. Mirogabalin was administered at 5 mg twice daily for the first week and uptitrated to 15 mg twice daily for a total duration of 14 weeks. The primary efficacy endpoint was the change from baseline in weekly average daily pain score (ADPS) at week 14; secondary endpoints included the ADPS responder rate, Short-Form McGill Pain Questionnaire visual analogue scale score, patient global impression of change (PGIC), average daily sleep interference score (ADSIS), EuroQol 5-dimensions 5-levels (EQ-5D-5L), and incidence of treatment-emergent adverse events (TEAEs).

RESULTS

Of 393 patients (mirogabalin, n = 196; placebo n = 197), the mean age was 58.2 years (mirogabalin, 58.7 years; placebo, 57.7 years) and 54.2% were male (mirogabalin, 56.1%; placebo, 52.3%). Mirogabalin elicited a greater change from baseline in the weekly ADPS vs. placebo at week 14: least-squares mean difference (95% confidence interval) vs. placebo - 0.39 (- 0.74, - 0.04), p = 0.0301. PGIC, ADSIS, and EQ-5D-5L data reflected significantly better improvements for patients receiving mirogabalin vs. placebo. The incidence of TEAEs was 75.0% and 75.1% in the mirogabalin and placebo groups, respectively. Most TEAEs were mild or moderate, and the incidence of TEAEs leading to treatment discontinuation was 2.6% in the mirogabalin group and 1.5% in the placebo group.

CONCLUSIONS

Although the effect size of mirogabalin was reduced due to the placebo effect, mirogabalin is a safe and effective treatment option for Chinese patients with DPNP.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT04094662.

Healthcare costs and medical utilization patterns associated with painful and severe painful diabetic peripheral neuropathy

PURPOSE

Painful diabetic peripheral neuropathy (DPN) is a common complication in patients with diabetes. It is associated with a poor quality of life and high costs of care. This study investigated the impact of painful DPN on healthcare costs and resource utilization.

METHODS

This was a retrospective analysis of administrative claims of adult patients with diabetes (type 1 or 2) from Optum's de-identified Clinformatics® Data Mart Database. Patients were assigned to four cohorts by presence of DPN and pain severity, based on diagnoses and prescription patterns in a one-year baseline. All-cause and diabetes-associated costs were calculated for the year following the index DPN diagnosis. Risk factors associated with presence of severely painful DPN were evaluated.

RESULTS

Relative to those without DPN, patients who had DPN without pain, painful DPN (PDPN), or severe PDPN incurred respective increases of $3,093, $9,349, and $20,887 in average annual all-cause costs. More than half of costs from painful/severe DPN were for prescriptions and inpatient hospitalization. Severe PDPN was associated with elevated odds of diabetic amyotrophy (OR: 8.09; 95% CI: 6.84-9.56), diabetic foot ulcers (OR: 6.54, 95% CI: 6.32-6.76), and loss of mobility (OR: 2.54, 95% CI: 2.48-2.60), among other complications.

CONCLUSIONS

Painful DPN is associated with higher healthcare costs and resource utilization, and a greater risk of debilitating conditions that limit quality of life. Future research should focus on better treatment options and more aggressive pain management strategies to reduce the negative impacts of DPN.

Characteristics and outcomes of peripheral neuropathic pain patients with repeated applications of high-concentration capsaicin cutaneous patch: Results of a retrospective chart review in Germany

OBJECTIVE

The aim of this study was to evaluate patient characteristics, concomitant analgesic medication, and pain intensity in a real-world setting in Germany, focusing on the repeated application of high-concentration capsaicin patch (HCCP) for neuropathic pain.

DESIGN

Data were collected from electronic medical records of patients who received at least two HCCP treatments between January 2011 and July 2022. Subgroup analyses were performed based on the number of HCCP treatments, age groups, and specific neuropathic pain conditions.

SETTING

The study was conducted at an outpatient pain center in Wiesbaden, Germany.

SUBJECTS

The study included 97 patients, primarily diagnosed with neuropathic back pain, postoperative or post-traumatic neuropathic pain, and postherpetic neuralgia.

METHODS

The daily dose of concomitant medications (eg, opioids and anticonvulsants) at the start of capsaicin therapy was compared with the average within 2 years of capsaicin therapy. The last observation carried forward method was used if HCCP treatment was discontinued before the end of the 2-year period.

RESULTS

The majority of patients received concomitant medications, with opioids, anticonvulsants, and antidepressants being the most common. The average daily morphine equivalent dose decreased significantly during HCCP treatment. Pain intensity at baseline was generally high, but substantial improvements were observed in patients who received at least three HCCP applications.

CONCLUSIONS

This study provides evidence for the effectiveness of HCCP treatment in reducing pain intensity and concomitant opioid use in patients with neuropathic pain. Further research is needed to explore the long-term outcomes and optimal treatment regimens for different patient populations.

Neuropathic Pain Affects Quality of Life in Breast Cancer Survivors with Chemotherapy-Induced Peripheral Neuropathy

BACKGROUND

Despite the significant impact of chemotherapy-induced peripheral neuropathy on the quality of life for breast cancer survivors, there is a notable lack of comprehensive research. Therefore, a crucial need exists for further systematic investigation and inquiry into this matter.

AIMS

This study examined predictors of quality of life in breast cancer survivors with chemotherapy-induced peripheral neuropathy.

DESIGN

A cross-sectional, correlational design.

SETTINGS

This study was conducted at a medical center in northern Taiwan and a teaching hospital in northeastern Taiwan.

PARTICIPANTS/SUBJECTS

One hundred and thirty adult women with breast cancer, who have undergone chemotherapy and obtained a Total Neuropathy Scale-Clinical Version score>0, were enrolled.

METHODS

Neuropathic pain, sleep disturbances, depression, and quality of life were evaluated using multiple regression analysis to identify quality of life predictors. Clinical importance was established using the minimally important difference of Functional Assessment of Cancer Therapy-Breast.

RESULTS

The study indicated that improving depression (B = -10.87, p < .001) and neuropathic pain (B = -8.33, p = .004) may enhance the quality of life of breast cancer survivors with chemotherapy-induced peripheral neuropathy. Moreover, the individual's marital status and family history of breast cancer were identified as predictive factors.

CONCLUSIONS

This study illuminates quality of life determinants for breast cancer survivors with chemotherapy-induced peripheral neuropathy, advocating comprehensive care and addressing depression and neuropathic pain for better outcomes.

Conservative non-pharmacological treatments for chemotherapy-induced peripheral neuropathies in women treated for breast cancer: a systematic review

INTRODUCTION

Over the last few decades, the use of neo/adjuvant therapies has significantly increased the number of breast cancer survivors who experience chemotherapy-induced peripheral neuropathy (CIPN). To date, few, low-efficacy, pharmacological remedies exist to manage this side effect. For this reason, alternative treatments are increasingly being investigated as possible strategies to prevent or promote faster recovery from CIPN. In this review we aimed to provide an overview of the literature evidence regarding all the non-pharmacological and rehabilitative interventions for patients affected by CIPN secondary to breast cancer care.

EVIDENCE ACQUISITION

A comprehensive literature search was conducted on PubMed, Scopus and Web of Science and included a total of 1895 patients (1528 with breast cancer) with a wide range of CIPN (motor, sensory and autonomic neuropathies) and chemotherapy treatments (e.g., Taxanes, Platins, Vinca alkaloids or monoclonal antibody drugs).

EVIDENCE SYNTHESIS

Of the initial 1108 hits, only 25 studies - describing different treatment modalities for peripheral neuropathies - were finally included in the qualitative synthesis. Most studies focused on acupuncture, physiotherapy, cryotherapy, and yoga.

CONCLUSIONS

There is still controversial evidence on conservative non-pharmacological interventions for the management of CIPN symptoms. We believe however that moderate exercise, as well as all types of stress reducing activities like sport, yoga and mindfulness, should be encouraged in cancer patients for their positive effect on global physical and psychological health. Further studies of higher methodological quality are needed to determine the best conservative approach to CIPN.

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.

Pharmacological Interaction Between Cannabidiol and Tramadol on Experimental Diabetic Neuropathic Pain: An Isobolographic Analysis

Introduction: Diabetic neuropathies are the most prevalent chronic complications of diabetes, characterized by pain and substantial morbidity. Although many drugs have been approved for the treatment of this type of pain, including gabapentin, tramadol (TMD), and classical opioids, it is common to report short-term results or potentially severe side effects. TMD, recommended as a second-line treatment can lead to unwanted side effects. Cannabidiol (CBD) has been gaining attention recently due to its therapeutic properties, including pain management. This study aimed to characterize the pharmacological interaction between CBD and TMD over the mechanical allodynia associated with experimental diabetes using isobolographic analysis. Materials and Methods: After diabetes induction by streptozotocin (STZ), diabetic rats were systemically treated with CBD or TMD alone or in combination (doses calculated based on linear regression of effective dose 40% [ED40]) and had the mechanical threshold evaluated using the electronic Von Frey apparatus. Both experimental and theoretical additive ED40 values (Zmix and Zadd, respectively) were determined for the combination of CBD plus TMD in this model. Results: Acute treatment with CBD (3 or 10 mg/kg) or TMD (2.5, 5, 10, or 20 mg/kg) alone or in combination (0.38+1.65 or 1.14+4.95 mg/kg) significantly improved the mechanical allodynia in STZ-diabetic rats. Isobolographic analysis revealed that experimental ED40 of the combination (Zmix) was 1.9 mg/kg (95% confidence interval [CI]=1.2-2.9) and did not differ from the theoretical additive ED40 2.0 mg/kg (95% CI=1.5-2.8; Zadd), suggesting an additive antinociceptive effect in this model. Conclusions: Using an isobolographic analysis, these results provide evidence of additive pharmacological interaction between CBD and TMD over the neuropathic pain associated with experimental diabetes induced by STZ.

Ultramicronized Palmitoylethanolamide in the Management of Neuropathic Pain Related to Chronic Inflammatory Demyelinating Polyneuropathy: A Proof-of-Concept Study

Background/Objectives: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare autoimmune disease. Neuropathic pain (NP), related to peripheral inflammation, is among its earliest manifestations. This preliminary open-label investigation aimed to evaluate the efficacy of ultramicronized Palmitoylethanolamide (umPEA) in the management of NP. Methods: A total of 14 patients with CIDP, already undergoing immunoglobulin (Ig) therapy, were divided into two groups: Group A received umPEA 600 mg twice daily in addition to Ig for 60 days, followed by Ig alone until the end of the observation (180 days); Group B received Ig alone for 120 days and subsequently umPEA + Ig in the last 60 days of the study. Painful symptom intensity and quality of life were assessed by the Numeric Rating Scale, Neuropathic Pain Symptoms Inventory, and Five Dimensions Health Questionnaire. The safety umPEA profile was evaluated. Results: UmPEA in addition to immunoglobulins allowed for a significant improvement over time in all NP symptoms intensity (p = 0.0007) and in patients' quality of life (p = 0.0036). Conclusions: This study suggests umPEA as a safe and effective treatment in addition to immunoglobulins to improve NP, ameliorating the patient's health status. These results highlight the importance of neuroinflammation modulation in the management of CIDP's painful symptoms, drawing attention to umPEA's potential use also in neuropathies of different etiologies.

Knowledge, attitudes and practices of general practitioners on peripheral neuropathies in Benin in 2021

PURPOSE

First healthcare actors in neurological diseases management, General Practitioners (GPs) still limited in the assessment of Peripheral Neuropathies (PN). This study assesses the knowledge, attitudes, practices (KAP) of GPs on PN in Benin in 2021 and identifying associated factors to low KAP.

MATERIALS AND METHODS

It was a cross-sectional study conducted from 20 November 2020 to 30 June 2021 which included GPs registered in the National Order of Physicians in Benin and interns in last year of medical studies (MS). An overall KAP score of 24 points was derived. KAP levels were low (score < 17), medium (17 to 19) and high (score ≥ 20). Multivariable regression models were performed to identify factors associated with low KAP.

RESULTS

645/1,066 participants (60.5%) were included in the study with median age 28 years [Interquartile range IQR: 26-30 years], and 442 (68.5%) were male. The KAP level was low in 70.1%. 16.7% had a low knowledge of polyneuropathy manifestations, 35% perceived PN as an incurable disease. Lack of knowledge on PN before MS (adjusted Odds-ratio aOR = 1.6 [95% confidence interval CI: 1.1-2.3]), and no postgraduate training on PN (aOR = 1.8 [95% CI: 1.--3.0]) were associated with low overall KAP level. Working in rural area (aOR = 0.4 [95%CI: 0.2-0.7]), and being an intern (aOR = 0.6 [95%CI: 0.4-0.9]) were associated with better overall KAP level.

CONCLUSION

This study highlights the need for better training with strong emphasis on PN during the MS and the organization of postgraduate training for GPs; the cornerstone for improving the management of PN in Benin.

Impact of pain and adverse health outcomes on long-term US testicular cancer survivors

BACKGROUND

No study has quantified the impact of pain and other adverse health outcomes on global physical and mental health in long-term US testicular cancer survivors or evaluated patient-reported functional impairment due to pain.

METHODS

Testicular cancer survivors given cisplatin-based chemotherapy completed validated surveys, including Patient-Reported Outcomes Measurement Information System v1.2 global physical and mental health, Patient-Reported Outcomes Measurement Information System pain questionnaires, and others. Multivariable linear regression examined relationships between 25 adverse health outcomes with global physical and mental health and pain-interference scores. Adverse health outcomes with a β^  of more than 2 are clinically important and reported below.

RESULTS

Among 358 testicular cancer survivors (median age = 46 years, interquartile range [IQR] = 38-53 years; median time since chemotherapy = 10.7 years, IQR = 7.2-16.0 years), median adverse health outcomes number was 5 (IQR = 3-7). A total of 12% testicular cancer survivors had 10 or more adverse health outcomes, and 19% reported chemotherapy-induced neuropathic pain. Increasing adverse health outcome numbers were associated with decreases in physical and mental health (P < .0001 each). In multivariable analyses, chemotherapy-induced neuropathic pain (β^ = -3.72; P = .001), diabetes (β^ = -4.41; P = .037), obesity (β^ = -2.01; P = .036), and fatigue (β^ = -8.58; P < .0001) were associated with worse global mental health, while being married or living as married benefited global mental health (β^ = 3.63; P = .0006). Risk factors for pain-related functional impairment included lower extremity location (β^ = 2.15; P = .04) and concomitant peripheral artery disease (β^ = 4.68; P < .001). Global physical health score reductions were associated with diabetes (β^ = -3.81; P = .012), balance or equilibrium problems (β^ = -3.82; P = .003), cognitive dysfunction (β^ = -4.43; P < .0001), obesity (β^ = -3.09; P < .0001), peripheral neuropathy score (β^ = -2.12; P < .0001), and depression (β^ = -3.17; P < .0001).

CONCLUSIONS

Testicular cancer survivors suffer adverse health outcomes that negatively impact long-term global mental health, global physical health, and pain-related functional status. Clinically important factors associated with worse physical and mental health identify testicular cancer survivors requiring closer monitoring, counseling, and interventions. Chemotherapy-induced neuropathic pain must be addressed, given its detrimental impact on patient-reported functional status and mental health 10 or more years after treatment.

Patient-reported outcomes after free muscle flap coverage for therapy-resistant neuropathic pain from the ulnar nerve

Extensive microsurgical neurolysis followed by free gracilis muscle flap coverage can be performed as a last resort for patients with persistent neuropathic pain of the ulnar nerve. All patients who had this surgery between 2015 and 2021 were identified. Data were collected from the medical records of 21 patients and patient-reported outcomes were collected from 18 patients, with a minimum follow-up of 12 months. The median visual analogue pain score decreased significantly 8 months postoperatively from 8.0 to 6.0 and stabilized to 5.4 at the 3-year follow-up. Health-related quality-of-life scores remained diminished compared to normative data. In the treatment of therapy-resistant neuropathic pain of the ulnar nerve, extensive neurolysis with a subsequent free gracilis muscle flap coverage shows a promising reduction of pain that persists at long-term follow-up.Level of evidence: IV.

Multimodal Approaches in the Treatment of Chronic Peripheral Neuropathy-Evidence from Germany

Patients with chronic peripheral neuropathy suffer greatly and their quality of life is often restricted. Drug therapy can be accompanied by undesirable side effects and intolerances, or the hoped-for effect does not materialize. Therefore, in addition to drug therapy, attempts are also made to treat the physical symptoms with complementary procedures. In the case of severe forms, the search for a suitable form of therapy is difficult. Complex treatments can be an innovative way to treat peripheral neuropathy. At the same time, several different therapy methods are carried out at high frequency by a specialized treatment team. This study aimed to provide an overview of possible complementary forms of therapy. The focus was on a comparison of two interdisciplinary complex therapies that are used in severe cases in an acute inpatient care setting in Germany. The six dimensions (energy, sleep, pain, physicality, emotional response and social isolation) of the Nottingham Health Profile (NHP) were used to assess quality of life. Both complex treatments (naturopathic complex therapy/multimodal pain therapy) showed a significant reduction in impairment in all dimensions of the NHP. In addition, a multivariate analysis was carried out to take into account several influencing variables at the same time. At the time of admission to the hospital, the degree of chronicity was recorded for each patient. This allowed statements to be made about the effect of the respective therapy depending on the chronification stage of the patient. It has been shown that patients with acutely exacerbated pain with the highest degree of chronicity also benefit from both complex treatments. The naturopathic complex treatment gives the treatment team more options. Aspects such as nutrition, methods from phytotherapy and traditional Chinese medicine can be integrated into inpatient care. Thus, a patient-centered, holistic therapy can take place. However, an interdisciplinary holistic therapy requires more time for both the practitioner and the patient. This should be taken into account in the health systems in the context of the diagnosis related groups.

Non-pharmacological management of neuropathic pain in older adults: a systematic review

INTRODUCTION

Neuropathic pain encompasses multiple diagnoses with detrimental impacts on quality of life and overall health. In older adults, pharmacological management is limited by adverse effects and drug interactions, while surgical management involves perioperative risk. Prior reviews addressing non-pharmacological interventions for neuropathic pain have not focused on this demographic. Therefore, this systematic review synthesizes the evidence regarding the effectiveness of non-pharmacological interventions in reducing neuropathic pain severity in older adults.

METHODS

PubMed, CINAHL, Web of Science, and PsycInfo were searched using key terms, with inclusion criteria of age ≥ 65, neuropathic pain, non-pharmacological intervention, pain severity measurement, English language, peer-reviewed, and either randomized controlled trial (RCT) or quasi-experimental design. In total, 2759 records were identified, with an additional 28 records identified by review of reference lists. After removal of duplicates, 2288 records were screened by title and abstract, 404 full-text articles were assessed, and 19 articles were critically reviewed and synthesized.

RESULTS

Of the 14 RCTs and 5 quasi-experimental studies included in the review, the most common intervention was electric and/or magnetic therapy, followed by acupuncture, mindfulness meditation, exercise, and light therapy. Several studies revealed both statistical and clinical significance, but conclusions were limited by small sample sizes and methodological shortcomings. The interventions were generally safe and acceptable.

CONCLUSIONS

Results should be interpreted with consideration of clinical vs statistical significance, mediators of pain severity, and individual variations in effectiveness. Further research should address multimodal and novel interventions, newer models of care, and technology-based interventions.

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.

Feasibility of therapeutic Chinese massage (tui na) for peripheral neuropathy among people with human immunodeficiency virus: findings of a pilot randomized controlled trial

Background

Peripheral neuropathy (PN) is prevalent in people with human immunodeficiency virus (PHIV) with no Food and Drug Administration-approved treatment. Therapeutic Chinese massage (TCM) is a promising noninvasive and non-harmful intervention for HIV-related PN. However, relevant research is lacking. The purpose of this study is to evaluate the feasibility of TCM for HIV-related PN.

Method

We conducted a pilot, single-centered, two-arm, double-blinded, randomized controlled trial. Twenty eligible PHIV were recruited primarily from the AIDS Foundation Houston, Inc. in Texas and were randomly assigned into two groups. Ten participants in the intervention group received three weekly 25-min TCM sessions by a certified TCM therapist. The remaining ten control group participants received the same therapist's three weekly 25-min placebo massage sessions on their lower extremities. The outcome was the feasibility of this study as measured by recruitment and completion rates, participant safety, and treatment adherence and compliance, as well as the effect size of the intervention.

Results

The study population comprised 20 PHIV (mean age 55.23). This study showed high feasibility as measured by a high rate of recruitment, a 100% rate of completion, and zero serious adverse events. As we inquired 21 respondents for eligibility for the study, all except one had HIV-related PN. All respondents were willing to participate in the study and adhered to the group assignment after they enrolled in the study. The participants' baseline pain was at a medium to a high level (6.30 [2.15] out of 10).

Conclusion

Chinese massage is a feasible intervention in PHIV. Future relevant randomized controlled trials are expected.

Clinical trial registration

https://clinicaltrials.gov/, NCT05379140.

Health-related quality of life and spinal cord stimulation in painful diabetic neuropathy

Peripheral neuropathic pain, including painful diabetic neuropathy (PDN), is associated with marked negative impact on health-related quality of life (HRQoL). The magnitude of reduction of HRQoL experienced by individual PDN patients appears to be strongly associated with their level of pain and disease severity. In spite of the availability of a range of pharmacotherapy, a substantive proportion of PDN patients continue to experience suboptimal HRQoL. Such patients are potential candidates for spinal cord stimulation (SCS) devices. Three randomised controlled trials in over 300 patients with refractory PDN have shown that the addition of SCS to standard of care therapy results in important health gains, including pain reduction and enhancement of HRQoL. Sham-controlled RCTs that enable blinding of patients, clinicians and researchers are needed to confirm the role of SCS in PDN.

Effects of Neural Mobilization in Diabetic Peripheral Neuropathy: A Scoping Review

Objective

The purpose of this scoping review was to explore the effects of neural mobilization (NM) on outcomes in adults with diabetic peripheral neuropathy (DPN).

Methods

Five databases were searched-PubMed, Web of Science (Web of Science Core Collection), Physiotherapy Evidence Database (PEDro), and Scopus-from inception to January 2022. The studies included were randomized controlled trials, pre-post single group design, multiple case studies, controlled case studies, quasi-experimental studies, and single case studies, which are published in full text in English.

Results

Six studies were included in this review, and most were of low-level evidence. The sample size of the studies ranges from 20 to 43, except for 1 case study, with a total of 158 participants in all the studies combined. In 4 out of 6 studies, only NM was given, whereas in 2 studies, NM was used along with other treatment strategies. The tibial nerve was the most studied nerve, whereas 1 study administered NM to nerves of the upper limbs, and only 1 trial examined the sciatic nerve. The outcomes included the Michigan Neuropathy Screening Instrument questionnaire, nerve conduction velocity, vibration perception threshold, heat/cold perception threshold, weight-bearing asymmetry and range of motion of lower limb, quality of life, and magnetic imaging changes.

Conclusion

At present, only a few low-level studies exist on the use of NM for the treatment of adults with DPN. The evidence for use of NM on DPN is still limited and insufficient.

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.

Living with chemotherapy-induced peripheral neuropathy: a nested qualitative study

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting side-effect for patients undergoing a variety of chemotherapy regimens. These effects can have a detrimental impact on patients' quality of life and ability to perform everyday tasks.

OBJECTIVE

This study aimed to explore the experience of living with CIPN prior to and while participating in a randomised study of acupuncture versus a control wait group.

DESIGN

The study was nested within a randomised trial (n=120) with participants randomised to acupuncture or to control (wait list for acupuncture).

METHOD

Participants (n=23) volunteered to be interviewed either by telephone (n=20) or face to face (n=3). The audiotapes produced were transcribed verbatim and analysed using a thematic approach.

RESULTS

Four themes developed; these included daily life with CIPN, signs and symptoms, interacting with others and management of CIPN. Patients reported compromised dexterity and ability to safely carry out activities. They were often reliant on help and sought out information from others living with the condition. There were also concerns about the lack of effectiveness and the side-effects of medication prescribed.

CONCLUSION

Participants were self-selecting volunteers across different cancer groups, but the information gathered could influence future study designs and increase understanding of the impact of CIPN on patients' lives.

Declining Incidence Rates of Distal Symmetric Polyneuropathy in People With Type 1 and Type 2 Diabetes in Denmark, With Indications of Distinct Patterns in Type 1 Diabetes

OBJECTIVE

It is not known if incidence rates for diabetic distal symmetric polyneuropathy (DSPN) are decreasing, as they are for other diabetic complications. Here, we investigated incidence rates of DSPN in type 1 and type 2 diabetes in a large population-based study.

RESEARCH DESIGN AND METHODS

In the period 1996 to 2018, 19,342 individuals were identified at a Danish tertiary diabetes center. Vibration perception threshold was assessed by biothesiometry and repeated throughout the study. Exclusion of prevalent DSPN cases or missing data left data on 9,473 individuals for analysis of DSPN using a cutoff of >25 V and on 2,783 individuals for analysis using an age-, sex-, and height-specific cutoff. Poisson regression analysis was used to model incidence rates of DSPN for both cutoff types and separately for diabetes types. Covariates were sex, age, diabetes duration, and calendar time.

RESULTS

Incidence rates (95% CI) of DSPN decreased from 1996 to 2018 (e.g., from 4.78 [3.60-6.33]/100 person-years [PY] to 1.15 [0.91-1.47]/100 PY for 40-year-old men with type 1 diabetes and from 16.54 [11.80-23.18]/100 PY to 8.02 [6.63-9.69]/100 PY for 60-year-old men with type 2 diabetes, when using >25 V as the cutoff value). Analyses using age-, sex-, and height-specific cutoff values demonstrated similar incidence patterns by calendar time without sex differences. For type 1 diabetes, decreasing incidence rates were seen with older age.

CONCLUSIONS

Incidence rates for DSPN are declining in type 1 and type 2 diabetes, possibly due to improved diabetes treatment. This causality remains to be explored. Distinct age-related patterns indicate that the pathophysiology of DSPN may differ between diabetes types.

Electroacupuncture alleviates neuropathic pain caused by SNL by promoting M2 microglia polarization through PD-L1

As a common clinical disease, neuropathic pain is difficult to be cured with drugs. The occurrence and progression of pain is closely related to the response of spinal microglia. Aspartof the regulation of microglialactivity,PD-L1 playsacriticalrole. Loss of PD-L1 promoted the polarization of M1-like microglia. Increased expression of PD-L1 promoted M2-like polarization. Electroacupuncture has a significant analgesic effect in clinical practice, but its specific mechanism remains to be further explored. In this study, we verified the role of PD-L1 in EA analgesia and the underlying molecular mechanism through spinal nerve ligation (SNL) in rats and lipopolysaccharide (LPS)-treated BV2 microglial cells. Forbehavioralstudiesofrats,mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured, and spinal cord neuros were examined under transmission electron microscopyto determine changes to their myelin structure. The expression levels of PD-L1 and M1/M2-specific markers in rat spinal cord and BV2 microglial cells were measured by enzyme-linked immunosorbent assay, flow cytometry, immunofluorescence staining and Western blot analysis. Our study showed that EA increased the pain threshold, reduced the destruction of myelin structure, promoted the expression of PD-L1 and PD-1, inhibited the MAPK signaling pathway, and promoted the conversion of microglial polarization from the M1 phenotype to the M2 phenotype in SNL rats. PD-L1 knockdown reversed these effects of EA. In addition, PD-L1 knockdown activated the MAPK signaling pathway, promoted microglial polarization to the M1 phenotype, decreased the expression of anti-inflammatory mediators and increased the expression of proinflammatory factors in LPS-stimulated BV2 microglial cells. Our results showed that EA may regulate the excitability of primary afferent neurons through PD-L1 and then inhibit the MAPK signaling pathway to promote the transformation of activated M1 microglia into M2 microglia, reduce inflammatory reactions, and finally achieve analgesic effects. A therapy targeting PD-L1 may be an effective strategy for treating neuropathic pain.

Usability and Acceptability of a Videoconference Program for the Treatment of Depression in Adults With Peripheral Neuropathy

Peripheral neuropathy is a debilitating neurological disorder affecting 13% to 14% of the US population. Estimates for co-occurring mood disorders in individuals with neuropathy range from 30% to 47%, but sparse evidence exists regarding depression treatment for adults with neuropathy. A cognitive-behavioral treatment, Acceptance and commitment therapy, is known to reduce depression in people with chronic pain, but little is known about its effectiveness in adults with neuropathy, particularly when the treatment is provided via videoconference. Acceptability and usability of this therapeutic treatment provided via videoconference was assessed in participants with peripheral neuropathy and symptoms of depression. Participants completed pre- and post-self-report outcome measures: the nine-item depression scale of the Patient Health Questionnaire and the 36-item Short-Form Health Survey. They also completed the Acceptability e-Scale and Post-Study System Usability Questionnaire after treatment. Depression decreased significantly, with scores declining from an average of 9.2 to 5.1 on the Patient Health Questionnaire ( P < .05). The Short-Form Health Survey indicated significant improvement post-treatment on the "Energy/Fatigue" and "Emotional Well Being" subscales. The intervention was rated by participants as acceptable and demonstrated high usability. This initial therapeutic treatment via videoconference offers promise to treat depression in older adults with neuropathy.

Differential Effects of Regulatory T Cells in the Meninges and Spinal Cord of Male and Female Mice with Neuropathic Pain

Immune cells play a critical role in promoting neuroinflammation and the development of neuropathic pain. However, some subsets of immune cells are essential for pain resolution. Among them are regulatory T cells (Tregs), a specialised subpopulation of T cells that limit excessive immune responses and preserve immune homeostasis. In this study, we utilised intrathecal adoptive transfer of activated Tregs in male and female mice after peripheral nerve injury to investigate Treg migration and whether Treg-mediated suppression of pain behaviours is associated with changes in peripheral immune cell populations in lymphoid and meningeal tissues and spinal microglial and astrocyte reactivity and phenotypes. Treatment with Tregs suppressed mechanical pain hypersensitivity and improved changes in exploratory behaviours after chronic constriction injury (CCI) of the sciatic nerve in both male and female mice. The injected Treg cells were detected in the choroid plexus and the pia mater and in peripheral lymphoid organs in both male and female recipient mice. Nonetheless, Treg treatment resulted in differential changes in meningeal and lymph node immune cell profiles in male and female mice. Moreover, in male mice, adoptive transfer of Tregs ameliorated the CCI-induced increase in microglia reactivity and inflammatory phenotypic shift, increasing M2-like phenotypic markers and attenuating astrocyte reactivity and neurotoxic astrocytes. Contrastingly, in CCI female mice, Treg injection increased astrocyte reactivity and neuroprotective astrocytes. These findings show that the adoptive transfer of Tregs modulates meningeal and peripheral immunity, as well as spinal glial populations, and alleviates neuropathic pain, potentially through different mechanisms in males and females.

What's New in Neuropathy?

Neuropathic pain presents diagnostic and treatment challenges. Despite recent advances in our understanding of the diagnosis and treatment of neuropathy, much remains to be elucidated. Familiar with neuropathy is the paradox that aberrant nerve signaling causes both sensory loss and pain. Voltage-gated sodium channels play an important role in neuronal electrogenesis and communication among neurons, and their dysregulation leads to hyperexcitability and pain. While numerous validated diagnostic assessment tools are available for neuropathy, patients often experience a diagnostic delay about the cause of their neuropathy. New research is defining more specific types of neuropathy beyond peripheral and central forms. The prevalence of pain varies by type of neuropathy, with chronic idiopathic axonal polyneuropathy associated with the highest proportion of patients experiencing pain. In the majority of types, it exceeds 50%. Gluten neuropathy, a form of peripheral neuropathy, is a new diagnostic consideration. It may require electrochemical conductance testing of hands and feet to test for sudomotor dysfunction. Among those with serologically confirmed gluten sensitivity or celiac disease, gluten neuropathy is a common neurological manifestation and may be addressed at least partially by a gluten-free diet. In Greece, a new neuropathic pain registry was created in 2014 in order to help gather data from real-world neuropathic pain patients. While still in its earliest phase, this registry has already produced demographic and treatment data that suggest suboptimal prescribing and less than recommended use of interventional procedures. Awareness campaigns are underway to encourage more Greek pain clinics to participate in this important registry.

Diabetic neuropathy: Pathogenesis and evolving principles of management

The global rise of prediabetes and diabetes has spawned an epidemic of complications associated with these conditions. Neuropathy is the most common consequence, with distal symmetric polyneuropathy (DSP) being the most prevalent. Diabetic neuropathy (DN) is a debilitating consequence of diabetes mellitus resulting in the highest morbidity and death, besides imposing a substantial financial burden on the patient. Loss of sensory function commencing distally in the lower limbs, accompanied by discomfort and considerable morbidity, characterizes diabetic neuropathy. The clinical evaluation and therapeutic options for diabetic peripheral neuropathy are multifaceted. At least fifty percent of people with diabetes acquire diabetic neuropathy over time. Good glycemic control halts the evolution in individuals with Type 1 diabetes mellitus. These results have prompted fresh attempts to comprehend the origin and develop new guidelines for prevention and treatment. New recommendations have also been established for the treatment of painful DN using separate classes of medications, with an emphasis on avoiding the use of opioids. Although our comprehension of the intricacies of diabetic neuropathy has progressed significantly over the past decade, the unique processes driving the neuropathy in type 1 and type 2 diabetes remain unexplained. Currently, glycemic control and pain management are the only effective therapies. While glucose management significantly reduces neuropathy development in type 1 diabetics, the effect is considerably lower in type 2 diabetics. Evidence supports the use of anticonvulsants and antidepressants for diabetic peripheral neuropathy pain treatment. However, the absence of disease-modifying medications for diabetic DSP necessitates the identification of unrecognized modifiable risk factors. It is imperative to identify the 'missed' risk factors and targets, allowing comprehensive, individualized care for patients.

Painful Peripheral Neuropathies of the Lower Limbs and/or Lower Extremities Treated with Spinal Cord Stimulation: A Systematic Review with Narrative Synthesis

Introduction

Painful peripheral neuropathy (PPN) is a debilitating condition with varied etiologies. Spinal cord stimulation (SCS) is increasingly used when conservative treatments fail to provide adequate pain relief. Few published reviews have examined SCS outcomes in all forms of PPN.

Methods

We conducted a systematic review of SCS in PPN. The PubMed database was searched up to February 7th, 2022, for peer-reviewed studies of SCS that enrolled PPN patients with pain symptoms in their lower limbs and/or lower extremities. We assessed the quality of randomized controlled trial (RCT) evidence using the Cochrane risk of bias tool. Data were tabulated and presented narratively.

Results

Twenty eligible studies documented SCS treatment in PPN patients, including 10 kHz SCS, traditional low-frequency SCS (t-SCS), dorsal root ganglion stimulation (DRGS), and burst SCS. In total, 451 patients received a permanent implant (10 kHz SCS, n=267; t-SCS, n=147; DRGS, n=25; burst SCS, n=12). Approximately 88% of implanted patients had painful diabetic neuropathy (PDN). Overall, we found clinically meaningful pain relief (≥30%) with all SCS modalities. Among the studies, RCTs supported the use of 10 kHz SCS and t-SCS to treat PDN, with 10 kHz SCS providing a higher reduction in pain (76%) than t-SCS (38-55%). Pain relief with 10 kHz SCS and DRGS in other PPN etiologies ranged from 42-81%. In addition, 66-71% of PDN patients and 38% of nondiabetic PPN patients experienced neurological improvement with 10 kHz SCS.

Conclusion

Our review found clinically meaningful pain relief in PPN patients after SCS treatment. RCT evidence supported the use of 10 kHz SCS and t-SCS in the diabetic neuropathy subpopulation, with more robust pain relief evident with 10 kHz SCS. Outcomes in other PPN etiologies were also promising for 10 kHz SCS. In addition, a majority of PDN patients experienced neurological improvement with 10 kHz SCS, as did a notable subset of nondiabetic PPN patients.

Traumatic peripheral nerve injuries: a classification proposal

BACKGROUND

Peripheral nerve injuries (PNIs) include several conditions in which one or more peripheral nerves are damaged. Trauma is one of the most common causes of PNIs and young people are particularly affected. They have a significant impact on patients' quality of life and on the healthcare system, while timing and type of surgical treatment are of the utmost importance to guarantee the most favorable functional recovery. To date, several different classifications of PNIs have been proposed, most of them focusing on just one or few aspects of these complex conditions, such as type of injury, anatomic situation, or prognostic factors. Current classifications do not enable us to have a complete view of this pathology, which includes diagnosis, treatment choice, and possible outcomes. This fragmentation sometimes leads to an ambiguous definition of PNIs and the impossibility of exchanging crucial information between different physicians and healthcare structures, which can create confusion in the choice of therapeutic strategies and timing of surgery.

MATERIALS

The authors retrospectively analyzed a group of 24 patients treated in their center and applied a new classification for PNI injuries. They chose (a) five injury-related factors, namely nerve involved, lesion site, nerve type (whether motor, sensory or mixed), surrounding tissues (whether soft tissues were involved or not), and lesion type-whether partial/in continuity or complete. An alphanumeric code was applied to each of these classes, and (b) four prognostic codes, related to age, timing, techniques, and comorbidities.

RESULTS

An alphanumeric code was produced, similar to that used in the AO classification of fractures.

CONCLUSIONS

The authors propose this novel classification for PNIs, with the main advantage to allow physicians to easily understand the characteristics of nerve lesions, severity, possibility of spontaneous recovery, onset of early complications, need for surgical treatment, and the best surgical approach.

LEVEL OF EVIDENCE

according to the Oxford 2011 level of evidence, level 2.

The effects of aerobic exercise on neuroimmune responses in animals with traumatic peripheral nerve injury: a systematic review with meta-analyses

BACKGROUND

Increasing pre-clinical evidence suggests that aerobic exercise positively modulates neuroimmune responses following traumatic nerve injury. However, meta-analyses on neuroimmune outcomes are currently still lacking. This study aimed to synthesize the pre-clinical literature on the effects of aerobic exercise on neuroimmune responses following peripheral nerve injury.

METHODS

MEDLINE (via Pubmed), EMBASE and Web of Science were searched. Controlled experimental studies on the effect of aerobic exercise on neuroimmune responses in animals with a traumatically induced peripheral neuropathy were considered. Study selection, risk of bias assessment and data extraction were performed independently by two reviewers. Results were analyzed using random effects models and reported as standardized mean differences. Outcome measures were reported per anatomical location and per class of neuro-immune substance.

RESULTS

The literature search resulted in 14,590 records. Forty studies were included, reporting 139 comparisons of neuroimmune responses at various anatomical locations. All studies had an unclear risk of bias. Compared to non-exercised animals, meta-analyses showed the following main differences in exercised animals: (1) in the affected nerve, tumor necrosis factor-α (TNF-α) levels were lower (p = 0.003), while insulin-like growth factor-1 (IGF-1) (p < 0.001) and Growth Associated Protein 43 (GAP43) (p = 0.01) levels were higher; (2) At the dorsal root ganglia, brain-derived neurotrophic factor (BDNF)/BDNF mRNA levels (p = 0.004) and nerve growth factor (NGF)/NGF mRNA (p < 0.05) levels were lower; (3) in the spinal cord, BDNF levels (p = 0.006) were lower; at the dorsal horn, microglia (p < 0.001) and astrocyte (p = 0.005) marker levels were lower; at the ventral horn, astrocyte marker levels (p < 0.001) were higher, and several outcomes related to synaptic stripping were favorably altered; (4) brainstem 5-HT2A receptor levels were higher (p = 0.001); (5) in muscles, BDNF levels (p < 0.001) were higher and TNF-α levels lower (p < 0.05); (6) no significant differences were found for systemic neuroimmune responses in blood or serum.

CONCLUSION

This review revealed widespread positive modulatory effects of aerobic exercise on neuroimmune responses following traumatic peripheral nerve injury. These changes are in line with a beneficial influence on pro-inflammatory processes and increased anti-inflammatory responses. Given the small sample sizes and the unclear risk of bias of the studies, results should be interpreted with caution.

Systemic and Peripheral Mechanisms of Cortical Stimulation-Induced Analgesia and Refractoriness in a Rat Model of Neuropathic Pain

Epidural motor cortex stimulation (MCS) is an effective treatment for refractory neuropathic pain; however, some individuals are unresponsive. In this study, we correlated the effectiveness of MCS and refractoriness with the expression of cytokines, neurotrophins, and nociceptive mediators in the dorsal root ganglion (DRG), sciatic nerve, and plasma of rats with sciatic neuropathy. MCS inhibited hyperalgesia and allodynia in two-thirds of the animals (responsive group), and one-third did not respond (refractory group). Chronic constriction injury (CCI) increased IL-1β in the nerve and DRG, inhibited IL-4, IL-10, and IL-17A in the nerve, decreased β-endorphin, and enhanced substance P in the plasma, compared to the control. Responsive animals showed decreased NGF and increased IL-6 in the nerve, accompanied by restoration of local IL-10 and IL-17A and systemic β-endorphin. Refractory animals showed increased TNF-α and decreased IFNγ in the nerve, along with decreased TNF-α and IL-17A in the DRG, maintaining low levels of systemic β-endorphin. Our findings suggest that the effectiveness of MCS depends on local control of inflammatory and neurotrophic changes, accompanied by recovery of the opioidergic system observed in neuropathic conditions. So, understanding the refractoriness to MCS may guide an improvement in the efficacy of the technique, thus benefiting patients with persistent neuropathic pain.

Safety, Tolerability and Pharmacokinetics of Single and Multiple Doses of Mirogabalin in Healthy Chinese Participants: A Randomized, Double-Blind, Placebo-Controlled Study

INTRODUCTION

Mirogabalin is a treatment option for patients with neuropathic pain; however, safety, tolerability, and pharmacokinetics (PK) data specifically for Chinese individuals are limited to a single-dose study. We aimed to assess these for both single- and multiple-dose mirogabalin in healthy Chinese participants.

METHODS

In this randomized, double-blind, placebo-controlled, phase I study, 54 healthy Chinese men and women aged 18-45 years were randomly allocated to receive single- (5, 10, or 15 mg, daily) or multiple-dose (5 mg titrated to 15 mg, twice-daily, over 22 days) oral mirogabalin or placebo. In each of three single-dose groups, 10 participants received mirogabalin and 2 received placebo; in the multiple-dose group, 14 participants received mirogabalin and 4 received placebo. The primary endpoints were PK, safety, and tolerability variables, including treatment-emergent adverse events (TEAEs), laboratory tests, and vital signs. PK data were collected for both single- and multiple-dose cohorts and evaluated by non-compartmental analysis.

RESULTS

Single- and multiple-dose mirogabalin was generally well tolerated with no deaths, serious TEAEs, or TEAEs leading to treatment discontinuation. Frequently reported TEAEs included dizziness, nystagmus, increased blood triglycerides, headache, and increased blood uric acid and creatine phosphokinase. Single-dose mirogabalin was rapidly absorbed (median time to maximum plasma concentration, 1.00 h) and eliminated (mean terminal elimination half-life, 2.57-3.08 h). The exposure was approximately dose-proportional. In the multiple-dose cohort, the trough plasma concentration increased dose-proportionally, and exposure and clearance were comparable to that following a single 15-mg dose. The mean cumulative amount excreted into urine up to 48 h post-dose increased in a dose-proportional manner, the mean cumulative percentage excreted into urine was 61.9%-74.3%, and renal clearance remained relatively constant.

CONCLUSION

Consistent with previous phase I studies in other populations, mirogabalin was safe and well tolerated in healthy Chinese participants at single and multiple doses of up to 15 mg twice-daily.

Higher Levels of Cerebrospinal Fluid and Plasma Neurofilament Light in Human Immunodeficiency Virus-Associated Distal Sensory Polyneuropathy

BACKGROUND

Neurofilament light (NFL) chain concentrations, reflecting axonal damage, are seen in several polyneuropathies but have not been studied in human immunodeficiency virus (HIV) distal sensory polyneuropathy (DSP). We evaluated NFL in cerebrospinal fluid (CSF) and plasma in relation to DSP in people with HIV (PWH) from 2 independent cohorts and in people without HIV (PWoH).

METHODS

Cohort 1 consisted of PWH from the CHARTER Study. Cohort 2 consisted of PWH and PWoH from the HIV Neurobehavioral Research Center (HNRC). We evaluated DSP signs and symptoms in both cohorts. Immunoassays measured NFL in CSF for all and for plasma as well in Cohort 2.

RESULTS

Cohort 1 consisted of 111 PWH, mean ± SD age 56.8 ± 8.32 years, 15.3% female, 38.7% Black, 49.6% White, current CD4+ T-cells (median, interquartile range [IQR]) 532/µL (295, 785), 83.5% with plasma HIV RNA ≤50 copies/mL. Cohort 2 consisted of 233 PWH of similar demographics to PWH in Cohort 1 but also 51 PWoH, together age 58.4 ± 6.68 years, 41.2% female, 18.0% Black, Hispanic, non-Hispanic White 52.0%, 6.00% White. In both cohorts of PWH, CSF and plasma NFL were significantly higher in both PWH with DSP signs. Findings were similar, albeit not significant, for PWoH. The observed relationships were not explained by confounds.

CONCLUSIONS

Both plasma and CSF NFL were elevated in PWH and PWoH with DSP. The convergence of our findings with others demonstrates that NFL is a reliable biomarker reflecting peripheral nerve injury. Biomarkers such as NFL might provide, validate, and optimize clinical trials of neuroregenerative strategies in HIV DSP.

Tui Na for painful peripheral neuropathy in people with human immunodeficiency virus: A randomized, double-blind, placebo-controlled trial protocol

Background

Peripheral neuropathy (PN), including numbness, loss of sensation, paresthesia, a burning sensation, and stabbing pain in extremities, is a common complication in people with human immunodeficiency virus (PHIV). Medications commonly used to treat HIV-related PN are not effective and lead to many side effects. HIV-related PN symptoms may be alleviated or treated with a series of therapeutic Chinese foot massages (TCFM), which are non-invasive and relatively safe. However, relevant studies are lacking.

Study design

This proposed trial is a prospective, two-arm, parallel, double-blinded, randomized controlled trial.

Aim

This proposed trial aims to assess the effectiveness of TCFM on HIV-related PN in people with HIV (PHIV).

Outcomes

The primary outcomes, measured at baseline, end of TCFM/placebo, and twelve weeks after, include (1), lower extremity pain, (2) lower extremity functioning, and (3) health-related quality of life. The secondary outcomes, measured throughout the trial process, include (1) recruitment and completion rate (No. of referred, No. of eligible, No. of enrolled, No. of withdrawals, trial recruitment rate, and trial completion rate), (2) participants' safety (No. and severity of adverse events), (3) treatment adherence (average time of each message session, No. of completed sessions, and No. of missed sessions), and (4) compliance (No. of participants completing the trial following the initial group assignment).

Sample size

An estimated 142 participants in total, or 71 participants in each arm, will be needed for this trial.

Trial status

This trial was registered at ClinicalTrials.gov of the National Institute of Health on Oct 26, 2022 (ClinicalTrials.gov Identifier: NCT05596123). The researchers expect to recruit participants starting in Feb. 2023 and ending in Feb 2025.

Quality of life and satisfaction in patients surgically treated for cubital tunnel syndrome

OBJECTIVE

Cubital tunnel syndrome (CuTS) results from compression of the ulnar nerve at the elbow, resulting in pain, weakness, and numbness of the hand and forearm. This work describes the Quality of Life (QoL) and satisfaction after CuTS surgery and identifies the factors associated with those outcomes.

METHODS

This cross-sectional study included patients surgically treated for CuTS from January 2011 to September 2021 at the Neurosurgery Clinic of the Clinic Center in Serbia. The questionnaires applied were the Short Form 36 (SF-36), EuroQol instrument (EQ-5D-5 L), Bishop's score and Patient-Rated Ulnar Nerve Evaluation (PRUNE).

RESULTS

Sixty-two patients met the inclusion criteria. Bishop's score: The median score was 10 (7.75-11), 54.8% of the cases presented excellent results. PRUNE: The median score for symptoms was 19 (6-38.5); for functional, was 14 (0.75-38); and the total was 18.25 (5.87-34.12). SF-36: The subscale with the best result was social functioning (84.68 ± 22.79). The scale with the worst value was emotional well-being (49.35 ± 7.87). EQ-5D-5L: Over 50% patients did not present problems with mobility, self-care, activity, and anxiety. The average EQ-VAS was 72.77 ± 18.70; and 0.72 ± 0.21 of the EQ-index, revealing a good QoL. Models for QoL and satisfaction: Ten models showed statistical significance. The variables with major involvement were body mass index and time evolution of the symptoms.

CONCLUSION

Surgical decompression has proved to diminish the symptoms, improving QoL and satisfaction. Many fixed and changeable factors can affect the satisfaction levels after surgery.

Physiotherapy interventions for pain relief in individuals with peripheral neuropathic pain: A systematic review and meta-analyses of randomized controlled trials

OBJECTIVE

To evaluate the effectiveness of physiotherapy interventions on peripheral neuropathic pain (pNeP) due to any underlying cause.

METHODS

Multiple databases were searched from database inception until Dec 2021. Studies on physiotherapy interventions for pain relief assessed using the visual analogue scale among individuals with pNeP of any underlying cause were included. Methodological quality was assessed using the PEDro scale and the quality of the evidence using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool.

RESULTS

The searches yielded 1498 articles. Seventeen studies met the inclusion criteria and were included in the review. Meta-analysis revealed a significant benefit for laser therapy compared to sham laser on pNeP (weighted mean difference [WMD] -1.27; 95% CI: -2.29 to -0.25; p = 0.01) in people with carpal tunnel syndrome. The pooled analyses revealed a significant effect of spinal cord stimulation compared to control for failed back syndrome (standardised mean difference [SMD; Hedges'g] -0.73; 95% CI: -1.17 to -0.30; p = 0.001) and diabetic neuropathy (SMD -1.63; 95% CI -2.06--1.21; p < 0.001). The effect of acupuncture on chemotherapy-induced pain (SMD - 2.09; 95% CI: -4.27-0.09; p = 0.06) and electromagnetic stimulation on diabetic neuropathic pain (Hedges' g - 0.77; 95% CI: -1.82-0.27; p = 0.15) were insignificant.

CONCLUSION

Evidence supports the use of spinal cord stimulation for the treatment of pNeP secondary to failed back surgery syndrome and diabetic neuropathy. Laser therapy was more effective than sham laser for alleviating pain due to carpal tunnel syndrome. The efficacy of acupuncture and electromagnetic therapy for chemotherapy-induced pain and diabetic neuropathy, respectively remains inconclusive.

Non-pharmacological Interventions on Pain and Quality of Life in Chemotherapy Induced Polyneuropathy: Systematic Review and Meta-Analysis

BACKGROUND/AIM

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment, resulting in pain, numbness, instability, and thus affecting quality of life (QoL), occasionally leading to discontinuation of chemotherapy. Pharmacological treatments are not sufficient. Non-pharmacological interventions (NPIs) have also been tried. This study aimed to systematically review the efficacy of NPIs on pain and QoL in patients suffering from CIPN.

MATERIALS AND METHODS

The databases searched were Pubmed, Cohrane, and Scopus for randomized controlled trials (RCTs) published in the last 5 years (2017-2022). Studies were considered eligible, if they assessed adult patients suffering from CIPN because of any chemotherapeutic drug for any type and any stage of cancer and if study protocols included non-pharmacological intervention with a structured protocol.

RESULTS

A total of 1,496 records were identified. Finally, 10 RCTs including 495 patients (253 in the intervention group and 242 in the control group) were included for meta-analysis. Intervention protocols included acupuncture (n=6), exercise (n=3), and yoga (n=1). NPIs significantly reduced neuropathic pain. However, the effect on QoL was not significant.

CONCLUSION

NPIs are beneficial in the treatment of pain in patients with CIPN but their impact on QoL is not statistically supported. Larger sample sizes, more homogenous in outcome measures and interventions are needed to further explore NPIs' efficacy on CIPN symptoms.

A cervical cancer biorepository for pharmacogenomics research in Zimbabwe

BACKGROUND

Research infrastructures such as biorepositories are essential to facilitate genomics and its growing applications in health research and translational medicine in Africa. Using a cervical cancer cohort, this study describes the establishment of a biorepository consisting of biospecimens and matched phenotype data for use in genomic association analysis and pharmacogenomics research.

METHOD

Women aged > 18 years with a recent histologically confirmed cervical cancer diagnosis were recruited. A workflow pipeline was developed to collect, store, and analyse biospecimens comprising donor recruitment and informed consent, followed by data and biospecimen collection, nucleic acid extraction, storage of genomic DNA, genetic characterization, data integration, data analysis and data interpretation. The biospecimen and data storage infrastructure included shared -20 °C to -80 °C freezers, lockable cupboards, secured access-controlled laptop, password protected online data storage on OneDrive software. The biospecimen or data storage, transfer and sharing were compliant with the local and international biospecimen and data protection laws and policies, to ensure donor privacy, trust, and benefits for the wider community.

RESULTS

This initial establishment of the biorepository recruited 410 women with cervical cancer. The mean (± SD) age of the donors was 52 (± 12) years, comprising stage I (15%), stage II (44%), stage III (47%) and stage IV (6%) disease. The biorepository includes whole blood and corresponding genomic DNA from 311 (75.9%) donors, and tumour biospecimens and corresponding tumour DNA from 258 (62.9%) donors. Datasets included information on sociodemographic characteristics, lifestyle, family history, clinical information, and HPV genotype. Treatment response was followed up for 12 months, namely, treatment-induced toxicities, survival vs. mortality, and disease status, that is disease-free survival, progression or relapse, 12 months after therapy commencement.

CONCLUSION

The current work highlights a framework for developing a cancer genomics cohort-based biorepository on a limited budget. Such a resource plays a central role in advancing genomics research towards the implementation of personalised management of cancer.

Use of Accelerometry as an Educational Tool for Spinal Cord Stimulation: A Pilot Study

BACKGROUND

Spinal cord stimulation (SCS) is an important option for patients with chronic neuropathic pain. In the United States, a successful SCS trial determines eligibility for SCS implant. Metrics to determine success are often self-reported and subjective, which may limit achievement of patient goals. This study aimed to assess whether patients undergoing SCS implant after successful trial felt that use of external accelerometry prior to implant was a useful educational tool to objectively appraise function and achievement of treatment goals.

METHODS

This was a single center, prospective, pilot study. Sixteen subjects with persistent spinal pain syndrome type 2 underwent a percutaneous SCS trial. Five subjects did not have a successful trial, one expired after the SCS trial, before implant, and one dropped out prior to completion of post-implant follow-up visits. Nine subjects underwent SCS implant and completed the required follow-up visits. All subjects were provided an Actigraph GT3X external accelerometer, worn 7 days prior to the trial to determine baseline physical activity and during the 7-day trial to assess for change in activity from baseline. Results were shared with subjects to individualize goals for therapy. Goal attainment was assessed at 1, 3, and 6 months after implant. Subjects wore the accelerometer again 24 hours before visits to update progress in meeting treatment goals. The primary outcome was satisfaction with using accelerometry as an educational tool to appraise function and guide treatment goals for SCS therapy. Secondary outcomes included physical activity, as captured via accelerometry, as well as validated patient-reported measures of pain severity, physical functioning, and quality-of-life.

RESULTS

Eight of nine subjects were satisfied with accelerometry as an educational tool. Secondary outcomes were not reliably assessed due to poor stewardship and study execution.

CONCLUSION

External accelerometry may assist patients in developing individualized functional treatment goals for SCS therapy.

Nox, Nox, Are You There? The Role of NADPH Oxidases in the Peripheral Nervous System

Significance: Reactive oxygen species (ROS) contribute to multiple aspects of peripheral nervous system (PNS) biology ranging from physiological processes (e.g., axonal outgrowth and regeneration) to pathophysiology (e.g., nerve degeneration). Although ROS are derived from multiple sources, NADPH oxidase (Nox) family members are dedicated to ROS generation. Noxs are expressed in the PNS, and their overexpression is associated with detrimental effects on nerve function and contributes, at least in part, to peripheral neuropathies. Recent Advances: Of the seven members, studies mostly focused on Nox1, Nox2, and Nox4, which are expressed in the PNS in a cell-specific manner. We have also recently identified human Nox5 in sural nerve biopsies. When maintained at homeostatic levels, Noxs regulate several aspects of peripheral nerve health, most notably neurite outgrowth and axonal regeneration following nerve lesion. While Nox2 and Nox4 dysregulation is a major source of oxidative stress in PNS disorders, including neuropathic pain and diabetic peripheral neuropathy, recent evidence also implicates Nox1 and Nox5. Critical Issues: Although there is compelling evidence for a direct role of Noxs on nerve function, little is known about their subcellular localization, intercellular regulation, and interaction. These, together with redox signaling, are considered crucial components of nerve redox status. In addition, the lack of isoform-specific inhibitors limits conclusions about the physiological role of Noxs in the PNS and their therapeutic potential in peripheral neuropathies. Future Directions: Future research using isoform-specific genetic and pharmacological approaches are therefore needed to better understand the significance of Nox enzymes in PNS (patho) physiology. Antioxid. Redox Signal. 37, 613-630.

Local hyperexcitability of C-nociceptors may predict responsiveness to topical lidocaine in neuropathic pain

We explored whether increased C-nociceptor excitability predicts analgesic effects of topical lidocaine in 33 patients with mono- (n = 15) or poly-neuropathy (n = 18). Excitability of C-nociceptors was tested by transcutaneous electrical sinusoidal (4 Hz) and half sine wave (single 500 ms pulse) stimulation delivered to affected and non-affected sites. Analgesic effects of 24 hrs topical lidocaine were recorded. About 50% of patients reported increased pain from symptomatic skin upon continuous 4 Hz sinusoidal and about 25% upon 500 ms half sine wave stimulation. Electrically-evoked half sine wave pain correlated to their clinical pain level (r = 0.37, p < 0.05). Lidocaine-patches reduced spontaneous pain by >1-point NRS in 8 of 28 patients (p < 0.0001, ANOVA). Patients with increased pain to 2.5 sec sinusoidal stimulation at 0.2 and 0.4 mA intensity had significantly stronger analgesic effects of lidocaine and in reverse, patients with a pain reduction of >1 NRS had significantly higher pain ratings to continuous 1 min supra-threshold sinusoidal stimulation. In the assessed control skin areas of the patients, enhanced pain upon 1 min 4 Hz stimulation correlated to increased depression scores (HADS). Electrically assessed C-nociceptor excitability identified by slowly depolarizing electrical stimuli might reflect the source of neuropathic pain in some patients and can be useful for patient stratification to predict potential success of topical analgesics. Central neuronal circuitry assessment reflected by increased pain in control skin associated with higher HADS scores suggest central sensitization phenomena in a sub-population of neuropathic pain patients.

Neuropathic pain correlates with worsening cognition in people with human immunodeficiency virus

Neuropathic pain and cognitive impairment are among the HIV-related conditions that have most stubbornly resisted amelioration by virally suppressive antiretroviral therapy. Overlaps between the regional brain substrates and mechanisms of neuropathic pain and cognitive disorders are increasingly recognized, yet no studies have examined the longitudinal relationship between these two disorders. Participants in the prospective, observational CNS HIV AntiRetroviral Therapy Effects Research (CHARTER) cohort underwent standardized clinical evaluations for clinical examination findings of distal sensory polyneuropathy, reporting distal neuropathic pain and neurocognitive performance at study entry (baseline) and an average of 12 years later. Change in neuropathic pain and neuropathy status from baseline to follow-up was by self-report and repeat examination, and change in neurocognitive performance was assessed using a previously published summary regression-based change score. Relationships between incident or worsened neuropathic pain and neurocognitive change were evaluated using uni- and multivariable regressions, including age at baseline and other relevant covariates. Participants were 385 people with HIV, 91 (23.6%) females, mean ± standard deviation (SD) age at baseline 43.5 (7.81) years, ethnicity 44.9% African American, 10.6% Hispanic, 42.6% non-Hispanic white and 1.82% other. Baseline median (interquartile range) nadir CD4 was 175 (34 309) cells/µl and current CD4 was 454 (279 639). Incident or worsened distal neuropathic pain occurred in 98 (25.5%) over the follow-up period. People with HIV with incident or worsened distal neuropathic pain had significantly worsened neurocognitive performance at follow-up compared to those without incident or worsened distal neuropathic pain (summary regression-based change score mean ± SD -0.408 ± 0.700 versus -0.228 ± 0.613; P = 0.0158). This effect remained significant when considering viral suppression on antiretroviral therapy, incident diabetes and other covariates as predictors. Overall neurocognitive change related to neuropathic pain was driven primarily by changes in the domains of executive function and speed of information processing. Those with incident distal neuropathy signs did not have neurocognitive worsening, nor did individuals who used opioid analgesics or other pain-modulating drugs such as amitriptyline. Worsened neurocognitive performance in people with HIV was associated with worsened neuropathic pain but not with changes in physical signs of neuropathy, and this was not attributable to therapies for pain or depression or to differences in viral suppression. This finding implies that incident or worsened pain may signal increased risk for neurocognitive impairment, and deserves more investigation, particularly if better pain management might stabilize or improve neurocognitive performance.

Effect of obesity on the associations of 25-hydroxyvitamin D with prevalent and incident distal sensorimotor polyneuropathy: population-based KORA F4/FF4 study

Background/objectives

The association between vitamin D and DSPN has been investigated in cross-sectional studies in individuals with diabetes. However, evidence from prospective and population-based studies is still lacking. Also, the potential modifying effect of obesity and glucose tolerance has not been investigated. Therefore, we examined the cross-sectional and prospective associations of serum 25(OH)D with DSPN and assessed possible effect modifications.

Subjects/methods

The study included individuals aged 62–81 years who participated in the German KORA F4 (2006–2008) and FF4 (2013–2014) studies. DSPN was assessed using the Michigan Neuropathy Screening Instrument. Cross-sectional analyses (n = 1065; 33% of the participants had obesity) assessed the associations of baseline 25(OH)D with prevalent DSPN, while prospective analyses (n = 422) assessed the associations of 25(OH)D with incident DSPN.

Results

No association was found between 25(OH)D and prevalent DSPN in the total sample after adjustment for age, sex, season of blood sampling, BMI, metabolic variables, lifestyle factors, and comorbidities. However, a decrease by 10 nmol/L in 25(OH)D was associated with prevalent DSPN (RR (95% CI) 1.08 (1.01, 1.16)) in individuals with obesity but not in normal-weight individuals (RR (95% CI) 0.97 (0.92, 1.02), p_interaction = 0.002). No evidence for effect modification by glucose tolerance was found (p > 0.05). In the prospective analysis, 25(OH)D levels in the first and second tertiles were associated with higher risk of DSPN (RR (95% CI) 1.18 (1.02; 1.38) and 1.40 (1.04; 1.90)) compared to the third tertile after adjustment for age, sex, season of blood sampling, and BMI. There was no evidence for effect modification by obesity or glucose tolerance categories.

Conclusions

Our study did not show consistent evidence for cross-sectional and prospective associations between serum 25(OH)D levels and DSPN in the total study population of older individuals. However, there was evidence for an association between lower serum 25(OH)D levels and higher prevalence of DSPN in individuals with obesity.

Association between Dietary Inflammatory Index Scores and Diabetes Sensorimotor Polyneuropathy in Patients with Type 2 Diabetes Mellitus: A Case-Control Study

Background

Diabetes sensorimotor polyneuropathy (DSPN) is a common complication of diabetes. Diet has been previously related to DSPN. However, no studies have investigated the relationship between the inflammatory potential of the whole diet and DSPN. So, we aimed to examine the association between dietary inflammatory index (DII) and DSPN in Iranian adults.

Methods

A total of 185 subjects with DSPN and 185 sex- and age-matched controls were selected in this case-control study. A 168-item validated food frequency questionnaire (FFQ) was used to assay dietary intakes. DII was calculated based on the developed formula. The Toronto clinical neuropathy score was applied to define DSPN. Binary logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (95% CIs) of DII in relation to DSPN.

Results

Mean values of age and BMI for all the participants were reported as 50.79 and 28.60, respectively. Also, the median (IQR) of DII for all the participants was estimated as −0.091 (−0.93, 1.07). Our findings suggest that participants in the highest quartile of the DII had higher odds of DSPN (OR = 1.76; 95% CI: 1.03, 3.36) (p-trend = 0.01) compared to subjects in the lowest quartile of DII scores after adjustment for age and sex. Additionally, a strong association was observed after adjusting for energy intake, physical activity, education, smoking status, economic status, marital status, job, BMI, and WC in model 2 (OR = 2.23, 95% CI = 1.13–4.39) (p-trend = 0.0048).

Conclusion

Higher DII score was associated with an increased risk of DSPN. Therefore, it is possible that a diet rich in anti-inflammatory nutrients and foods could improve and prevent DSPN.

The efficacy and safety of massage adjuvant therapy in the treatment of diabetic peripheral neuropathy: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The incidence of diabetic peripheral neuropathy (DPN) is increasing year by year. If patients cannot receive timely and effective treatment, DPN may lead to diabetic foot ulcers or even amputation. This risk factor has been widely concerned around the world. Massage, as a non-invasive physical therapy method, is gradually being applied in the adjuvant treatment of DPN. However, there is no systematic review of the adjuvant treatment of DPN by massage. Our study will explore the effectiveness and safety of massage applied in DPN.

METHODS

Eight electronic databases (PubMed, Cochrane, Web of Science, Sinomed, Embase, China National Knowledge Infrastructure, WanFang Data, Chongqing VIP Information) will be searched by our computer on February 9, 2022. A randomized controlled trial (RCT) of adjuvant massage therapy for DPN was screened. Primary outcome measures: efficiency, nerve conduction velocity. Secondary outcome measures: pain, blood glucose, and incidence of adverse reactions. The quality of the study was evaluated by two researchers using the RCT bias risk assessment tool in the Cochrane review manual Handbook5.4, and meta-analysis was performed by RevMan5.4 software.

RESULTS

RCTs will be used to evaluate the clinical efficacy of massage adjuvant therapy in DPN.

CONCLUSION

This study will provide evidence-based evidence for the safety and effectiveness of massage adjuvant therapy in DPN.

PROTOCOL REGISTRATION NUMBER

INPLASY202220025.

Neuropathic Pain in Neurologic Disorders: A Narrative Review

Neuropathic pain is defined as a painful condition caused by neurological lesions or diseases. Sometimes, neurological disorders may also be associated with neuropathic pain, which can be challenging to manage. For example, multiple sclerosis (MS) may cause chronic centralized painful symptoms due to nerve damage. Other chronic neuropathic pain syndromes may occur in the form of post-stroke pain, spinal cord injury pain, and other central pain syndromes. Chronic neuropathic pain is associated with dysfunction, disability, depression, disturbed sleep, and reduced quality of life. Early diagnosis may help improve outcomes, and pain control can be an important factor in restoring function. There are more than 100 different types of peripheral neuropathy and those involving sensory neurons can provoke painful symptoms. Accurate diagnosis of peripheral neuropathy is essential for pain control. Further examples are represented by gluten neuropathy, which is an extraintestinal manifestation of gluten sensitivity and presents as a form of peripheral neuropathy; in these unusual cases, neuropathy may be managed with diet. Neuropathic pain has been linked to CoronaVirus Disease (COVID) infection both during acute infection and as a post-viral syndrome known as long COVID. In this last case, neuropathic pain relates to the host’s response to the virus. However, neuropathic pain may occur after any critical illness and has been observed as part of a syndrome following intensive care unit hospitalization.

Adjuvant physical exercise for the management of painful polyneuropathy

INTRODUCTION

Physical exercise appeared to be effective, when implemented as an adjuvant to the pharmacotherapy option, in a variety of painful conditions. Peripheral neuropathic pain (PNP) is very prevalent and affects up to two-thirds of individuals with polyneuropathy (PN), regardless of etiology. The aim of this systematic review was to evaluate the currently available studies that assess adjuvant physical exercise for the management of PNP.

METHODS

A systematic literature search was conducted in the PubMed international database. For the systematic search, three medical subject headings (MeSH) were used. Term A was 'physical exercise' OR 'exercise' OR 'activity' OR 'workout' OR 'training'; term B was 'pain' OR 'painful'; term C was 'neuropathy' OR 'polyneuropathy.' Additionally, three filters were used: human subjects, English language, and full text. The reference lists of eligible papers and relevant reviews were also meticulously searched in order to include further relevant studies. Six papers eligible to be included were identified.

RESULTS

Physical exercise in various forms can be of benefit in the management of PNP when used as an adjuvant to the standard care. Overall, using the American Society of Interventional Pain Physicians (ASIPP) criteria, the current best available evidence exists for both aerobic and muscle strengthening exercise programs (level II evidence). The intensity of the exercise seems to play a significant role, with higher intensity interval training programs being more promising, though this remains to be confirmed in future studies.

CONCLUSIONS

Physical exercise is a promising non-pharmacological intervention for the management of PNP. Future RCTs should be conducted to make a face-to-face comparison of the available exercise treatments with the aim to design specific exercise programs for patients with PNP.

Sudomotor dysfunction in patients with gluten neuropathy

BACKGROUND AND AIM

Gluten neuropathy (GN) is a common neurological manifestation of gluten sensitivity (GS), characterized by serological evidence of GS, while other risk factors for developing neuropathy are absent. The degree of small fiber dysfunction in GN has not been studied in depth to date. Small fiber involvement may lead to pain, thermal perception abnormalities, and sweat gland dysfunction. Sudomotor innervation refers to the cholinergic innervation of the sympathetic nervous system through small fibers in the sweat glands. The aim of our study was to assess the sudomotor function of GN patients.

METHODS

Patients with GN were recruited. Clinical and neurophysiological data were obtained. HLA-DQ genotyping was performed. The skin electrochemical conductance (ESC) was measured with SUDOSCAN^TM.

RESULTS

Thirty-two patients (25 males, mean age 69.5±10.2 years) were recruited. Thirteen patients (40.6%) had abnormal sudomotor function of the hands. Sixteen patients (50%) had abnormal sudomotor function of the feet. Twenty-one patients (65.6%) had abnormal sudomotor function of either the hands or feet. Sudomotor dysfunction did not correlate with the type of neuropathy (length-dependent neuropathy or sensory ganglionopathy), gluten-free diet adherence, severity of neuropathy, and duration of disease or HLA-DQ genotype. No differences in the ESC were found between patients with painful and patients with painless GN.

CONCLUSION

Sudomotor dysfunction affects two-thirds of patients with GN. The lack of correlation between pain and sudomotor dysfunction suggests different patterns of small fiber involvement in patients with GN.