Pharmacological Management of Painful Peripheral Neuropathies: A Systematic Review

Mitochondrial translocator-protein ligand etifoxine reduces pain symptoms and protects against motor dysfunction development following peripheral nerve injury in rats

Peripheral nerve injury enhances mitochondrial translocator protein (TSPO) expression in the spinal cord and dorsal root ganglia (DRG), which is associated with neuroinflammation and mitochondrial dysfunction contributing to chronic pain development. Here, we investigate the effect of TSPO ligand Etifoxine, on the development of chronic pain and motor dysfunction following sciatic nerve injury. Mechanical and thermal sensitivity, as well as motor function, were measured in rats before and after sciatic nerve crush (SNC). Rats were treated with the Etifoxine (50 mg/kg, twice daily) for one week. At the end of the experiment, RT-PCR and immunohistochemistry (IHC) were performed to assess mitochondrial stress and neuroinflammation. Additionally, high-resolution respirometry (O2k) was used to evaluate mitochondrial function in the spinal cord following mitochondrial permeability transition pore (mPTP) induction by Ca2+. Etifoxine treatment post-SNC alleviated mechanical and thermal hypersensitivity, as well as motor dysfunction in rats. In addition, Etifoxine treatment modulates neuroinflammation and mitochondrial stress. Specifically, we found a significant reduction in microglia presence and the transcription of pro-inflammatory cytokines (TNFα, IL-6, IL-1β) in the DRG and spinal cord of the SNC/etifoxine-treated group. Furthermore, Etifoxine treatment prevent the decline in mitochondrial respiration, including non-phosphorylation, ATP-linked respiration, and maximal respiration, after mPTP induction by Ca2+. Our findings suggest that TSPO-ligand Etifoxine protects against motor dysfunction and the development of chronic pain by reducing neuroinflammation and apoptosis in the DRG and spinal cord. Importantly, the beneficial effects of TSPO-ligands are reflected in the restoration of the mitochondrial function under challenging conditions.

Supportive care for systemic amyloidosis: International Society of Amyloidosis (ISA) expert panel guidelines

Systemic amyloidosis refers to a group of protein misfolding disorders resulting in organ deposition with amyloid, leading to organ dysfunction, ultimately resulting in organ failure and death if not successfully treated. Treatment is type-specific and aimed at the underlying source of the misfolded protein. In the past decades, treatments have become increasingly available across the various amyloidosis types with improved response rates and longer survival. Supportive care measures are an integral part of care for patients with systemic amyloidosis to improve symptom burden and quality of life, reduce healthcare costs, and potentially prolong survival while type-directed therapy takes effect. In these guidelines, we provide supportive care recommendations across eight areas of interest in systemic amyloidosis: cardiology, nephrology, peripheral neuropathy, central nervous system involvement, autonomic neuropathy, gastroenterology, coagulopathy and bleeding, nutrition and hematology. These guidelines were developed on behalf of the International Society of Amyloidosis (ISA) by experts in the above fields and provide the best available evidence and expertise for supportive care in these rare disorders.

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.

A remotely delivered exercise-based rehabilitation program for patients with persistent chemotherapy-induced peripheral neuropathy (EX-CIPN): Protocol for a phase I feasibility trial

BACKGROUND

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a prevalent adverse effect of chemotherapy agents that is estimated to be present in 2/3 of patients who receive neurotoxic chemotherapy. In 30-40% of these patients, CIPN signs and symptoms can persist for months or years post-treatment. Recent studies have supported exercise as a feasible and possibly effective intervention for CIPN; however, more rigorous studies are needed to confirm feasibility, estimate efficacy, and clarify risk. In response, we developed an innovative virtual exercise-based rehabilitation program (EX-CIPN) for cancer survivors with persistent CIPN.

METHODS

This study is a phase I study conducted at the Princess Margaret Cancer Centre in cancer survivors with persistent CIPN, with a focus on feasibility, acceptability, and safety. A total of 40 patients aged 18 or older, with persistent CIPN at least 6 months after chemotherapy completion will be recruited and receive the EX-CIPN program. The EX-CIPN program is a 10-week virtual home-based intervention that includes an individualized exercise program supported with a mobile application (Physitrack), wearable technology (FitBit), and weekly virtual check-ins with an oncology exercise specialist. The primary outcome of feasibility will be assessed by examining accrual, retention, and adherence rates. Acceptability will be assessed through qualitative interviews. Safety events will be monitored and reported based on CTCAE v5. Secondary outcomes will be collected using questionnaires and physiological assessments at baseline (T1), after the intervention (T2), and 3-months after intervention (T3).

CONCLUSION

This phase I study will determine intervention feasibility, acceptability, and safety and will inform the planning for a future Phase II RCT with the EX-CIPN intervention.

Cannabis sativa L. Extract Increases COX-1, COX-2 and TNF-α in the Hippocampus of Rats with Neuropathic Pain

Inflammation is the critical component of neuropathic pain; therefore, this study aimed to assess the potential anti-inflammatory effects of Cannabis sativa L. extracts in a vincristine-induced model of neuropathic pain. The effects of different doses (5.0-40.0 mg/kg) of two Cannabis sativa L. extracts (B and D) on COX-1, COX-2, TNF-α, and NF-κB mRNA and protein levels were examined in the rat hippocampus, cerebral cortex, and blood lymphocytes. There were statistically significant differences in COX-1, COX-2, and TNF-α mRNA and protein expression in the hippocampus and cerebral cortex, with significant differences in COX-2 and TNF-α in the lymphocytes. Extract D dose-dependently increased COX-1 mRNA and protein in the hippocampus and cortex. In contrast, Extract B dose-dependently increased COX-1 mRNA and decreased COX-2 mRNA (in a dose of 7.5 mg/kg) and TNF-α protein levels in the cortex. Cannabis sativa L. extracts significantly influenced the expression of inflammatory genes and proteins, with effects varying based on dose and tissue type. The increased expression of COX-1, COX-2, and TNF-α (in comparison to groups receiving NaCl, vincristine, and gabapentin) in the rat hippocampus and COX-1 in the cerebral cortex suggests that Cannabis may have a pro-inflammatory effect. Due to species specificity, the results of our research based on rats require confirmation in humans. However, Cannabis sativa should be recommended with caution for treating pain with an inflammatory component.

An emerging aspect of cancer neuroscience: A literature review on chemotherapy-induced peripheral neuropathy

The nervous system governs both ontogeny and oncology. Foundational discoveries have clarified the direct communication of neurotransmitters with tumors and indirect interactions through neural effects on the immune system and the tumor microenvironment. Meantime, the nervous system is susceptible to cancer and its treatment. Chemotherapy-induced peripheral neuropathy (CIPN) is the most common side effects that significantly reduce the efficacy of anti-cancer treatment and patients' quality of life by leading to dose reduction or early cessation of chemotherapy. However, there are no effective strategies to reverse or treat CIPN. A better understanding of the mechanisms is expected to enable the development of the next generation of therapies. Here, we summarize the recent important studies on clinical manifestations, risk factors, prediction, pathogenesis, prevention, and treatment of CIPN. We also provide perspectives and insights regarding the rationales of bidirectional interactions between cancer and the nervous system.

A Review of Remote Monitoring in Neuromodulation for Chronic Pain Management

PURPOSE OF REVIEW

Neuromodulation techniques have emerged as promising strategies for managing chronic pain. These techniques encompass various modalities of nerve stimulation, including Spinal Cord Stimulation (SCS), Dorsal Root Ganglion Stimulation (DRG-S), and Peripheral Nerve Stimulation (PNS). Studies consistently demonstrate significant improvements in pain intensity, quality of life, and reduced opioid usage among patients treated with these modalities. However, neuromodulation presents challenges, such as the need for frequent in-person follow-up visits to ensure proper functionality of the implanted device. Our review explored factors impacting compliance in current neuromodulation users and examined how remote monitoring can mitigate some of these challenges. We also discuss outcomes of recent studies related to remote monitoring of neuromodulation.

RECENT FINDINGS

While remote monitoring capabilities for neuromodulation devices is an emerging development, there are promising results supporting its role in improving outcomes for chronic pain patients. Higher patient satisfaction, improved pain control, and reduced caretaker burdens have been observed with the use of remote monitoring. This review discusses the current challenges with neuromodulation therapy and highlights the role of remote monitoring. As the field continues to evolve, understanding the importance of remote monitoring for neuromodulation is crucial for optimizing pain management outcomes.

Pregabalin for Neuropathic Pain in Post-radiotherapy Head and Neck Cancer Patients: A Retrospective Study and Review of the Literature

INTRODUCTION

Head and neck cancer (HNC) patients may experience neuropathic pain (NP) due to radiotherapy (RT), which may become chronic. Pregabalin, an anticonvulsant, alters the transmission of painful stimuli at the synaptic level, modifying their perception. Pregabalin is used in NP treatment, but limited data exist on RT-treated HNC patients. This retrospective study aimed to present a case series of HNC patients with chronic NP after RT managed with pregabalin.

METHODS

HNC patients' records from the Department of Oral Medicine and Pathology and Hospital Dentistry, School of Dentistry, National and Kapodistrian University of Athens (NKUA), were searched. Outcome measures were obtained using the Douleur Neuropathique 4 (DN4) scale for NP and the numeric rating scale (NRS) for pain. The use of additional analgesic medication was also recorded.

RESULTS

Five HNC (four oral and one nasopharyngeal cancer) patients (mean age 58.5 years) who had received RT (mean total dose 64.7 gray (Gy)) and developed chronic (i.e., present for at least three months after RT) NP, characterized by a positive DN4 score ≥4, were identified. The initial assessment was five months to six years after RT (mean DN4=4.6±0.89 and mean NRS=6±3.08). "Burning," "pins and needles," and "numbness" were the NP descriptors mostly used. Pregabalin was titrated up to 150-300 mg per day; paracetamol and/or tramadol were also administered (daily doses 3000 mg and 100-150 mg, respectively). A substantial pain relief (≥50%) according to the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) (mean DN4=1.6±1.67 and NRS=1.6±1.67) was reported after two to three months of treatment, when tapering was initiated. Two patients (2/5) had complete remission of symptoms (DN4=0, NRS=0). No serious adverse effects were reported; one patient reported excess salivation.

CONCLUSIONS

Pregabalin may be a promising option for managing RT-related chronic NP in HNC patients. Further studies, including randomized controlled trials on RT-treated HNC patients, should be conducted.

Cannabis sativa L. Extract Alleviates Neuropathic Pain and Modulates CB1 and CB2 Receptor Expression in Rat

INTRODUCTION

Cannabis sativa L. (CSL) extract has pain-relieving potential due to its cannabinoid content, so the effects of two CSL extracts on alleviating neuropathic pain were investigated in vivo. Methods and groups: Male Wistar rats (n = 130) were divided into groups and received vincristine (0.1 mg/kg) and gabapentin (60 mg/kg) to induce and relieve neuropathic pain or CSL extracts (D and B). The mRNA and protein expression of the cannabinoid receptors type 1 and 2 (CB1R, CB2R) were evaluated in the cerebral cortex, hippocampus, and lymphocytes. Behavioural tests (Tail-Flick and von Frey) were performed on all animals.

RESULTS

VK-induced neuropathic pain was accompanied by decreased CB1R protein level and CB2R mRNA expression in the cortex. Gabapentin relieved pain and increased CB1R protein levels in the hippocampus compared to the vincristine group. Hippocampus CB1R protein expression increased with the administration of extract D (10 mg/kg, 40 mg/kg) and extract B (7.5 mg/kg, 10 mg/kg) compared to VK group. In the cerebral cortex CSL decreased CB1R protein expression (10 mg/kg, 20 mg/kg, 40 mg/kg of extract B) and mRNA level (5 mg/kg, 7.5 mg/kg of extract B; 20 mg/kg of extract D) compared to the VK-group.CB2R protein expression increased in the hippocampus after treatment with extract B (7.5 mg/kg) compared to the VK-group. In the cerebral cortex extract B (10 mg/kg, 20 mg/kg) increased CB2R protein expression compared to VK-group.

CONCLUSION

Alterations in cannabinoid receptor expression do not fully account for the observed behavioural changes in rats. Therefore, additional signalling pathways may contribute to the initiation and transmission of neuropathic pain. The Cannabis extracts tested demonstrated antinociceptive effects comparable to gabapentin, highlighting the antinociceptive properties of Cannabis extracts for human use.

Pharmacological and Non-pharmacological Approaches for the Management of Neuropathic Pain in Multiple Sclerosis

Multiple sclerosis is a chronic inflammatory disease that affects the central nervous system and can cause various types of pain including ongoing extremity pain, Lhermitte's phenomenon, trigeminal neuralgia, and mixed pain. Neuropathic pain is a major concern for individuals with multiple sclerosis as it is directly linked to myelin damage in the central nervous system and the management of neuropathic pain in multiple sclerosis is challenging as the options available have limited efficacy and can cause unpleasant side effects. The literature search was conducted across two databases, PubMed, and Google Scholar. Eligible studies included clinical trials, observational studies, meta-analyses, systematic reviews, and narrative reviews. The objective of this article is to provide an overview of literature on pharmacological and non-pharmacological strategies employed in the management of neuropathic pain in multiple sclerosis. Pharmacological options include cannabinoids, muscle relaxants (tizanidine, baclofen, dantrolene), anticonvulsants (benzodiazepines, gabapentin, phenytoin, carbamazepine, lamotrigine), antidepressants (duloxetine, venlafaxine, tricyclic antidepressants), opioids (naltrexone), and botulinum toxin variants, which have evidence from various clinical trials. Non-pharmacological approaches for trigeminal neuralgia may include neurosurgical methods. Non-invasive methods, physical therapy, and psychotherapy (cognitive behavioral therapy, acceptance and commitment therapy and mindfulness-based stress reduction) may be recommended for patients with neuropathic pain in multiple sclerosis. The choice of treatment depends on the severity and type of pain as well as other factors, such as patient preferences and comorbidities. There is a pressing need for healthcare professionals and researchers to prioritize the development of better strategies for managing multiple sclerosis-induced neuropathic pain.

An up-to-date view of paclitaxel-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN),referring to the damage to the peripheral nerves caused by exposure to a neurotoxic chemotherapeutic agent, is a common side effect amongst patients undergoing chemotherapy. Paclitaxel-induced peripheral neuropathy (PIPN) can lead to dose reduction or early cessation of chemotherapy, which is not conducive to patients'survival. Even after treatment is discontinued, PIPN symptoms carried a greater risk of worsening and plagued the patient's life, leading to long-term morbidity in survivors. Here, we summarize the research progress for clinical manifestations, risk factors, pathogenesis, prevention and treatment of PIPN, so as to embark on the path of preventing PIPN with prolongation of patient's life quality on a long-term basis.

Efficacy of Habb-e-Asab in diabetic peripheral neuropathy: a randomized placebo control study

OBJECTIVES

Diabetic peripheral neuropathy (DPN) is a common diabetes complication. The prevalence of neuropathy is 55% for type 1 and 66% for type 2 diabetes. In Unani medicine neuropathy is known as Khidr (numbness). It is treated with drugs possessing hypoglycemic and analgesic properties, etc. Habb-e-Asab, a polyherbal Unani formulation used for the treatment of Waja-ul-Asab (neuralgia) is routinely used for its indications in neurological pain in Unani medicine. The aim of this study to investigate the efficacy of Habb-e-Asab in diabetic peripheral neuropathy.

METHODS

Thirty patients with DPN were randomly assigned to test (n=20) and control (n=10) groups in a randomized single-blind placebo control study. For 45 days, the test group was given 250 mg Habb-e-Asab twice a day and the control group 250 mg placebo twice a day. The subjective parameters Pain in feet, burning in feet, and tingling in feet was assessed by the arbitrary scale and VAS fortnightly and objective parameters MNSI, and VPT was assessed in pre-post-treatment.

RESULTS

The research drug revealed highly statistically significant with p<0.001 on VAS score and MNSI whereas VPT is significant with p<0.01 on few points. But control group exhibits no significant effect in any of the parameters. No adverse effects had been reported in either group.

CONCLUSIONS

Our finding indicated that the Habb-e-Asab for 45 days improved and reduced the severity of DPN in a patient with diabetes (CTRI/2018/02/011725).

Painful Diabetic Peripheral Neuropathy: Practical Guidance and Challenges for Clinical Management

Painful diabetic peripheral neuropathy (PDPN) is present in nearly a quarter of people with diabetes. It is estimated to affect over 100 million people worldwide. PDPN is associated with impaired daily functioning, depression, sleep disturbance, financial instability, and a decreased quality of life. Despite its high prevalence and significant health burden, it remains an underdiagnosed and undertreated condition. PDPN is a complex pain phenomenon with the experience of pain associated with and exacerbated by poor sleep and low mood. A holistic approach to patient-centred care alongside the pharmacological therapy is required to maximise benefit. A key treatment challenge is managing patient expectation, as a good outcome from treatment is defined as a reduction in pain of 30-50%, with a complete pain-free outcome being rare. The future for the treatment of PDPN holds promise, despite a 20-year void in the licensing of new analgesic agents for neuropathic pain. There are over 50 new molecular entities reaching clinical development and several demonstrating benefit in early-stage clinical trials. We review the current approaches to its diagnosis, the tools, and questionnaires available to clinicians, international guidance on PDPN management, and existing pharmacological and non-pharmacological treatment options. We synthesise evidence and the guidance from the American Association of Clinical Endocrinology, American Academy of Neurology, American Diabetes Association, Diabetes Canada, German Diabetes Association, and the International Diabetes Federation into a practical guide to the treatment of PDPN and highlight the need for future research into mechanistic-based treatments in order to prioritise the development of personalised medicine.

A Review of Recent Pharmacological Advances in the Management of Diabetes-Associated Peripheral Neuropathy

Diabetic peripheral neuropathy is a common complication of longstanding diabetes mellitus. These neuropathies can present in various forms, and with the increasing prevalence of diabetes mellitus, a subsequent increase in peripheral neuropathy cases has been noted. Peripheral neuropathy has a significant societal and economic burden, with patients requiring concomitant medication and often experiencing a decline in their quality of life. There is currently a wide variety of pharmacological interventions, including serotonin norepinephrine reuptake inhibitors, gapentanoids, sodium channel blockers, and tricyclic antidepressants. These medications will be discussed, as well as their respective efficacies. Recent advances in the treatment of diabetes mellitus with incretin system-modulating drugs, specifically glucagon-like peptide-1 agonists, have been promising, and their potential implication in the treatment of peripheral diabetic neuropathy is discussed in this review.

Frontiers in diagnostic and therapeutic approaches in diabetic sensorimotor neuropathy (DSPN)

Diabetes sensory polyneuropathy (DSPN) is a significant complication of diabetes affecting up to 50% of patients in their lifetime and approximately 20% of patients suffer from painful diabetes neuropathic pain. DSPN - both painless and painful - leads to considerable morbidity including reduction of quality of life, increased lower limb amputations and is associated with worsening mortality. Significant progress has been made in the understanding of pathogenesis of DSPN and the last decade has seen newer techniques aimed at its earlier diagnosis. The management of painful DSPN remains a challenge despite advances made in the unravelling the pathogenesis of pain and its transmission. This article discusses the heterogenous clinical presentation of DSPN and the need to exclude key differential diagnoses. Furthermore, it reviews in detail the current diagnostic techniques involving both large and small neural fibres, their limitations and advantages and current place in the diagnosis of DSPN. Finally, the management of DSPN including newer pharmacotherapies are also discussed.

Diagnosis, management and impact of painful diabetic peripheral neuropathy: A patient survey in four European countries

AIMS

The aim of this study was to assess patient perspectives and experiences of the impact of neuropathic pain, painful diabetic neuropathy (pDPN) diagnosis and treatment, and the patient-healthcare professional (HCP) relationship.

METHODS

We conducted a quantitative online survey in Germany, the Netherlands, Spain, and the UK among adults with diabetes who responded "yes" to at least four of ten questions of in the Douleur Neuropathique en 4 Questions (DN4) questionnaire.

RESULTS

Of 3626 respondents, 576 met the eligibility criteria. Daily pain was rated as moderate or severe by 79 % of respondents. Most participants reported a negative impact of their pain on sleep (74 %), mood (71 %), exercise (69 %), concentration (64 %) and daily activities (62 %), and 75 % of those in employment had missed work because of their pain in the past year. Overall, 22 % of respondents avoided discussing pain with their HCP, 50 % had not received formal pDPN diagnosis, and 56 % had not used prescribed pain medications. Although two-thirds (67 %) of respondents reported feeling satisfied or very satisfied with treatment, 82 % of these patients still experienced daily moderate or severe pain.

CONCLUSIONS

Neuropathic pain in people with diabetes affects daily life and remains underdiagnosed and undertreated in clinical practice.

The Diagnostic Odyssey of Patients with Chronic Neuropathic Pain-Expert Opinion of Greek Pain Specialists

The diagnosis of chronic neuropathic pain requires a laborious process and can be a very long journey for the patients, one that can be characterized as an "odyssey." Our aim was to describe the "diagnostic odyssey" associated with chronic neuropathic pain in the Greek context. Specialized clinicians working at dedicated chronic pain and palliative care centers were asked to participate in a survey regarding the diagnostic process in Greece. In total, 44 respondents provided information on the organization of their centers, the diagnostic process, and the perceived obstacles involved in the diagnosis of chronic neuropathic pain. Most respondents reported that their centers were not fully or efficiently organized and believed that additional specialized healthcare personnel should be employed. Raising public awareness about the existence of such centers was also considered key. The two main obstacles in reaching a diagnosis were the difficulty non-experts had in recognizing chronic neuropathic pain and the lack of acknowledgement that chronic neuropathic pain is a condition that needs to be addressed. When considering these responses in light of the extended socioeconomic burden associated with chronic neuropathic pain, efforts should be made to limit the "diagnostic odyssey" of chronic neuropathic pain in Greece. The aim of this study is to explore the experience of patients with chronic neuropathic pain in Greece from the viewpoint of pain specialists. A better organization of pain and palliative care centers, facilitation of communication with previously treating clinicians, increased personnel, utilization of a chronic pain registry, and guidelines development can aid in this venture. Keypoints: The diagnosis of chronic neuropathic pain in Greece is a laborious and time-consuming process that needs to be refined; Greek clinicians believe that their centers were not fully or efficiently organized and think that additional specialized healthcare personnel should be employed; Patient comorbidities and retards in visiting a clinic at the onset of symptoms delay the diagnosis of neuropathic pain and may complicate subsequent care; The diagnostic delay has been reported as three years between the onset of symptoms and seeking general medical help and another nine years before a referral to a pain specialist; Neuropathic pain is associated with patient distress and socioeconomic burdens, and diagnostic delays prolong the condition, may allow it to worsen, and utilize valuable healthcare resources without providing effective solutions.

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.

[Post-traumatic pain mononeuropathies]

Neuropathic pain syndrome (NPS) caused by peripheral nerve (PN) injury is a serious clinical problem due to its prevalence, complexity of pathogenesis, significant impact on the quality of life of patients. The issues of epidemiology, pathogenesis and treatment of patients with NBS with PN injury are considered. Modern possibilities of invasive treatment of such patients are discussed.

Enriched enrollment randomized double-blind placebo-controlled cross-over trial with phenytoin cream in painful chronic idiopathic axonal polyneuropathy (EPHENE): a study protocol

Background

Patients with chronic idiopathic axonal polyneuropathy (CIAP) can have neuropathic pain that significantly impacts quality of life. Oral neuropathic pain medication often has insufficient pain relief and side effects. Topical phenytoin cream could circumvent these limitations.

The primary objectives of this trial are to evaluate (1) efficacy in pain reduction and (2) safety of phenytoin cream in patients with painful CIAP. The main secondary objective is to explore the usefulness of a double-blind placebo-controlled response test (DOBRET) to identify responders to sustained pain relief with phenytoin cream.

Methods

This 6-week, enriched enrollment randomized double-blind, placebo-controlled triple cross-over trial compares phenytoin 20%, 10% and placebo cream in 48 participants with painful CIAP. Enriched enrollment is based on a positive DOBRET in 48 participants who experience within 30 minutes ≥2 points pain reduction on the 11-point numerical rating scale (NRS) in the phenytoin 10% cream applied area and ≥1 point difference in pain reduction on the NRS between phenytoin 10% and placebo cream applied area, in favour of the former. To explore whether DOBRET has predictive value for sustained pain relief, 24 DOBRET-negative participants will be included.

An open-label extension phase is offered with phenytoin 20% cream for up to one year, to study long-term safety.

The main inclusion criteria are a diagnosis of CIAP and symmetrical neuropathic pain with a mean weekly pain score of ≥4 and <10 on the NRS.

The primary outcome is the mean difference between phenytoin 20% versus placebo cream in 7-day average pain intensity, as measured by the NRS, over week 2 in DOBRET positive participants.

Key secondary outcomes include the mean difference in pain intensity between phenytoin 10% and phenytoin 20% cream, and between phenytoin 10% and placebo cream. Furthermore, differences between the 3 interventions will be evaluated on the Neuropathic Pain Symptom Inventory, EuroQol EQ5-5D-5L, and evaluation of adverse events.

Discussion

This study will provide evidence on the efficacy and safety of phenytoin cream in patients with painful CIAP and will give insight into the usefulness of DOBRET as a way of personalized medicine to identify responders to sustained pain relief with phenytoin cream.

Trial registration

ClinicalTrials.gov NCT04647877. Registered on 1 December 2020.

Pharmacological Management of Neuropathic Pain after Radiotherapy in Head and Neck Cancer Patients: A Systematic Review

Background: Neuropathic pain (NP) in head and neck cancer (HNC) patients represents a treatment challenge. Most studies investigating drugs against NP are conducted in patients suffering with diabetic neuropathy or postherpetic neuralgia, while data are limited in cancer pain management. Additionally, regarding cancer therapy-related NP, most of the studies do not focus on HNC patients. The aim of this review is to identify the studies on systematically administered medication for NP management that included HNC patients under radiotherapy. Methods: A systematic literature search was performed, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, in PubMed, Cochrane Library, Web of Science and ClinicalTrials.gov on 30 October 2021. The medical subject heading (MeSH) terms were (“head and neck cancer” OR “tumor”) AND “neuropathic pain” AND “medication” AND “radiotherapy.” The Cochrane Collaboration tool was used for quality assessment. Results: The search identified 432 articles. Three more articles were identified after searching the reference lists of the retrieved articles. A total of 10 articles met the eligibility inclusion criteria and were included in this review; 6 on gabapentin, 1 on pregabalin, 1 on nortriptyline, 1 on methadone, and 1 on ketamine. Statistically significant results in pain reduction compared to placebo or standard pain medication were found in the studies on pregabalin (p = 0.003), methadone (p = 0.03), ketamine (p = 0.012), and in two out of six gabapentin studies (p < 0.004). Two of the studies (both concerning gabapentin) had no comparison arm. Conclusions: Treatments including pregabalin, methadone, ketamine, and gabapentin were found to provide pain relief against HNC NP. While there is a plethora of pharmacological treatments available for the management of NP, only a few studies have been conducted regarding the pharmacological management of therapy-related NP in HNC patients. More studies should be conducted regarding the pharmacological approaches in HNC therapy-related NP so that specific treatment algorithms can be developed.

Screening, diagnosis and management of diabetic sensorimotor polyneuropathy in clinical practice: International expert consensus recommendations

Diabetic sensorimotor polyneuropathy (DSPN) affects around one third of people with diabetes and accounts for considerable morbidity, increased risk of mortality, reduced quality of life, and increased health care costs resulting particularly from neuropathic pain and foot ulcers. Painful DSPN is encountered in 13-26% of diabetes patients, while up to 50% of patients with DSPN may be asymptomatic. Unfortunately, DSPN still remains inadequately diagnosed and treated. Herein we provide international expert consensus recommendations and algorithms for screening, diagnosis, and treatment of DSPN in clinical practice derived from a Delphi process. Typical neuropathic symptoms include pain, paresthesias, and numbness particularly in the feet and calves. Clinical diagnosis of DSPN is based on neuropathic symptoms and signs (deficits). Management of DSPN includes three cornerstones: (1) lifestyle modification, optimal diabetes treatment aimed at near-normoglycemia, and multifactorial cardiovascular risk intervention, (2) pathogenetically oriented pharmacotherapy (e.g. α-lipoic acid and benfotiamine), and (3) symptomatic treatment of neuropathic pain including analgesic pharmacotherapy (antidepressants, anticonvulsants, opioids, capsaicin 8% patch and combinations, if required) and non-pharmacological options. Considering the individual risk profile, pain management should not only aim at pain relief, but also allow for improvement in quality of sleep, functionality, and general quality of life.

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.

Pharmacotherapy of Painful Diabetic Neuropathy: A Clinical Update

The rising prevalence of diabetes mellitus (DM) leads on to an increase in chronic diabetic complications. Diabetic peripheral neuropathies (DPNs) are common chronic complications of diabetes. Distal symmetric polyneuropathy is the most prevalent form. Most patients with DPN will remain pain-free; however, painful DPN (PDPN) occurs in 6-34% of all DM patients and is associated with reduced health-related-quality-of-life and substantial economic burden. Symptomatic treatment of PDPN and diabetic autonomic neuropathy is the key treatment goals. Using certain patient related characteristics, subjects with PDPN can be stratified and assigned targeted therapies to produce better pain outcomes. The aim of this review is to discuss the various pathogenetic mechanisms of DPN with special reference to the mechanisms leading to PDPN and the various pharmacological and non-pharmacological therapies available for its management. Recommended pharmacological therapies include anticonvulsants, antidepressants, opioid analgesics, and topical medications.

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.

Pharmacologic agents directed at the treatment of pain associated with maladaptive neuronal plasticity

INTRODUCTION

The definition of nociplastic pain in 2016 has changed the way maladaptive chronic pain is viewed in that it may emerge without neural lesions or neural disease. Many endogenous and pharmacologic substances are being investigated for their role in treating the pain associated with neuronal plasticity.

AREAS COVERED

The authors review promising pharmacologic agents for the treatment of pain associated with maladaptive neuronal plasticity. The authors then provide the reader with their expert opinion and provide their perspectives for the future.

EXPERT OPINION

An imbalance between the amplification of ascending pain signals and the poor activation of descending inhibitory signals may be at the root of many chronic pain syndromes. The inhibitory activity of noradrenaline reuptake may play a role in neuropathic and nociplastic analgesia. A better understanding of the brain's pain matrix, its signaling cascades, and the complex bidirectional communication between the immune system and the nervous system may help meet the urgent and unmet medical need for safe, effective chronic pain treatment, particularly for pain with a neuropathic and/or nociplastic component.

Hypnosis Sedation Reduces the Duration of Different Side Effects of Cancer Treatments in Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

Simple Summary

Reducing side effects of cancer treatments is a major challenge for clinicians involved in the management of breast cancer patients. Among patients receiving neoadjuvant chemotherapy followed by surgery, radiotherapy and endocrine therapy, prolonged side effects frequently mentioned are: polyneuropathy, musculoskeletal pain, postoperative pain and cancer-related fatigue. Conventional drugs have proven to be ineffective in treating theses effects, except for postoperative pain. This is the reason why we prospectively tested the impact of hypnosis sedation used as anesthetic technique for breast cancer surgery on the different side effects of cancer treatment. Despite the limitations of this small non-randomized cohort, preliminary results are very encouraging.

Abstract

Background: Reducing side effects of cancer treatments is a major challenge for clinicians involved in the management of breast cancer patients. Methods: We analyzed data from 63 patients (32 in the general anesthesia group and 31 in the hypnosis sedation group) who were included in 1 prospective non-randomized trial evaluating hypnosis sedation in breast cancer treatment. The patients were followed every 3 months for 2 years. All patients received neoadjuvant chemotherapy with 4 cycles of epirubicin and cyclophosphamide followed by taxanes. Thereafter, patients underwent surgery while on general anesthesia or while on hypnosis sedation. Radiotherapy was administered according to institutional guidelines. Endocrine therapy was prescribed if tumors expressed hormone receptors. Prevalence, intensity and duration of polyneuropathy, musculoskeletal pain, postoperative pain and cancer-related fatigue were assessed at each medical visit. Results: Symptoms duration was statistically reduced for polyneuropathy (p < 0.05), musculoskeletal pain (p < 0.05) postoperative pain and cancer-related fatigue (p < 0.05) in the hypnosis group. Conclusion: Despite the limitations of this study (lack of randomization and small size) we conclude that hypnosis sedation may exert a role on different side effects of breast cancer treatment in patients receiving neoadjuvant chemotherapy, mainly by reducing their duration.

Treatment of neuropathic pain

Background: Neuropathic pain presents a therapeutic challenge because patients cannot be relieved from it, even when all known medical options have been tried. Several treatment guidelines have been provided, and several pharmacotherapies have been proposed with non-pharmacological treatments. This study aimed to present the current pharmacological and non-pharmacological treatments used to treat patients with neuropathic pain. Furthermore, several treatment guidelines for neuropathic pain are compared.Current Concepts: Tricyclic antidepressants, gabapentinoids, and serotonin-norepinephrine reuptake inhibitors are the first-line agents recommended by clinical guidelines in several countries. Tramadol and topical agents are recommended as second-line agents. Opioids and cannabinoids are recommended as third-line agents; cannabinoids are recommended by Canadian treatment guidelines. Combination therapy may be more effective because it results in synergistic pain-relieving effects, and the individual drug dose may be lower. Non-pharmacologic treatment is recommended as third-line or supplementary management because of the lack of evidence.Discussion and Conclusion: Several guidelines have recommended similar drugs; however, it is impossible to completely cure neuropathic pain. Therefore, therapeutic goals must be realistically discussed to improve patient compliance. In addition, additional studies based on pathophysiological mechanisms should be conducted to improve the management of neuropathic pain.

Emerging Role of C5 Complement Pathway in Peripheral Neuropathies: Current Treatments and Future Perspectives

The complement system is a key component of innate immunity since it plays a critical role in inflammation and defense against common pathogens. However, an inappropriate activation of the complement system is involved in numerous disorders, including peripheral neuropathies. Current strategies for neuropathy-related pain fail to achieve adequate pain relief, and although several therapies are used to alleviate symptoms, approved disease-modifying treatments are unavailable. This urgent medical need is driving the development of therapeutic agents for this condition, and special emphasis is given to complement-targeting approaches. Recent evidence has underscored the importance of complement component C5a and its receptor C5aR1 in inflammatory and neuropathic pain, indicating that C5a/C5aR1 axis activation triggers a cascade of events involved in pathophysiology of peripheral neuropathy and painful neuro-inflammatory states. However, the underlying pathophysiological mechanisms of this signaling in peripheral neuropathy are not fully known. Here, we provide an overview of complement pathways and major components associated with dysregulated complement activation in peripheral neuropathy, and of drugs under development targeting the C5 system. C5/C5aR1 axis modulators could represent a new strategy to treat complement-related peripheral neuropathies. Specifically, we describe novel C5aR allosteric modulators, which may potentially become new tools in the therapeutic armory against neuropathic pain.

Validation of the Patient Neurotoxicity Questionnaire for Patients Suffering From Chemotherapy-Induced Peripheral Neuropathy in Greek

PURPOSE

The Patient Neurotoxicity Questionnaire (PNQ) represents a diagnostic tool concerning patients with chemotherapy-induced peripheral neuropathy (CIPN). The application of such a tool in the Greek clinical praxis requires validation.

METHODS

Validation consists of three stages - translation, reverse translation, and patient application. Hundred oncologic patients were assessed by comparing the PNQ to the National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) at the chemotherapy onset and second, fourth, and sixth sessions. The diagnostic tool's specific requirements (compliance, validity, concordance, sensitivity, specificity, reliability) were statistically evaluated.

RESULTS

Differences between translated texts and between the reverse translation and the original were considered negligible. At the second, fourth, and sixth session compliance was 98%, 95%, and 93% while Cronbach's α was 0,57 0,69, and 0,81, respectively. Cohen's weighted κ was 0,67 and 0,58, Spearman's ρ was 0,7 and 0,98, while the area under the curve (AUC) of the receiver operating characteristic (ROC) was 1 and 0,9 for the sensory and the motor part, respectively. The variance's linear regression analysis confirmed CIPN worsening over time (P<0.0001).

DISCUSSION

The Greek version remains close to the original English version. Compliance rates reflect easy PNQ applications. Cohen's κ values highlight the physicians' tension to underestimate the patients' condition. Spearman's ρ, Cronbach's α, and AUC values reflect good validity, reliability, and specificity of the PNQ respectively. Finally, the linear analysis confirmed the PNQ sensitivity over time.

CONCLUSIONS

The PNQ validation in Greek adds a crucial tool to the physicians' armamentarium. It can now delineate the necessary information to modify the chemotherapy and analgesic treatment regimens at both preventive and acute levels.

COVID-19 Related Acro-Ischemic Neuropathic-like Painful Lesions in Pediatric Patients: A Case Series

BACKGROUND

A variety of skin manifestations have been associated with COVID-19 infection. Acral lesions on hands and feet, closely resembling chilblains, have been reported in association with COVID-19, which are nonspecific. These acro-ischemic painful lesions have been described mainly in asymptomatic and mildly symptomatic pediatric COVID-19 positive patients, without a precise pathogenetic mechanism. COVID-19-induced chilblains may portend an indolent course and a good outcome. In young patients, the IFN-1 response induces microangiopathic changes and produces a chilblain lupus erythematosus-like eruption with vasculitic neuropathic pain features.

OBJECTIVES

This paper presented a case series of pediatric patients with COVID-19-related skin lesions and neuropathic-like pain.

METHODS

Clinical outcomes were collected from 11 patients diagnosed with painful erythematous skin lesions with neuropathic-like pain and positive IgG for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

RESULTS

It is a mildly symptomatic condition not related to severe pain rates, and it is treated with paracetamol due to the transitory nature of the problem, which provides good results.

CONCLUSIONS

A particular point of interest is skin lesion manifestation as a further indirect sign of SARS-CoV-2 infection. Due to the initial manifestation of chilblains in pauci-symptomatic pediatric patients, they need to be immediately tested and isolated. Chilblains can be considered a clinical clue to suspect SARS-CoV-2 infection and help in early diagnosis, patient triage, and infection control.

Neuromodulation for Pain Management in the Inpatient Setting: A Narrative Review

Pain is highly prevalent and pharmacological therapy is not always efficacious. There are a few pathophysiological reasons to believe that neuromodulation would increase the rate of success of pain management. This review article is focused on that aspect, discussing non-invasive or minimally invasive neuromodulation techniques in both the inpatient and outpatient setting. This article provides an in-depth discussion of the multiple neuromodulation techniques available over time to be suitable and effective when used as analgesic therapies for chronic pain. We reviewed the literature and discussed all available neuromodulation options that were tested in the inpatient and outpatient setting. Neuromodulation plays a very important role in treating chronic pain in both inpatient and outpatient setting.

Anti-Cholinergic Drug Burden Among Ambulatory Elderly Patients in a Nigerian Tertiary Healthcare Facility

Background: The use of drugs with anticholinergic effects among elderly patients is associated with adverse clinical outcomes. There is paucity of information about anticholinergic drug burden among Nigerian elderly population. Objectives: To determine the anticholinergic drug burden among elderly Nigerian patients. Methods: This was a retrospective cross-sectional study conducted among elderly patients (aged 65 and above) who visited the Family Medicine outpatients' clinics of the Ekiti State University Teaching Hospital, Ado-Ekiti, Nigeria between July 1 and October 31, 2018. Information extracted from the case files included patient's age, sex, diagnoses, and list of prescribed medications. Medicines with anticholinergic effects were identified and scored using the anticholinergic drug burden calculator (http://www.acbcalc.com). Results: The medical records of 400 patients were analyzed with females accounting for 60.5% of the study population. The mean age of participants was 73 ± 7.4 years with only 28 (7%) of patients having more than two co-morbid conditions. Polypharmacy was identified in 152 (38%) of the patients while 147 (36.7%) had drugs with anticholinergic effects prescribed. The anticholinergic burden was high in 60 (15%) patients. Polypharmacy was significantly associated with having more than two diagnosed conditions and high anticholinergic burden (p value of < 0 .001 and 0.013 respectively). There was significant correlation between total number of prescribed drugs and count of diagnoses (r = 0.598; p < 0 .000) and between total number of prescribed drugs and number of drugs with anticholinergic effects (r = 0 .196; p < 0 .000). Conclusion: The anticholinergic burden in this group of elderly Nigerian patients was low; majority (67%) had no exposure to drugs with anticholinergic effects with only 15% having high anticholinergic burden. Polypharmacy and multiple diagnosed conditions were positively associated with high anticholinergic burden. Based on the positive and significant correlations found in this study, a reduction in the number of prescribed medicines especially those with significant anticholinergic effects used for secondary indications may lessen the anticholinergic burden among the elderly.

Electroacupuncture Alleviates Diabetic Peripheral Neuropathy by Regulating Glycolipid-Related GLO/AGEs/RAGE Axis

Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes mellitus (DM) and affects over one-third of all patients. Neuropathic pain and nerve dysfunction induced by DM is related to the increase of advanced glycation end products (AGEs) produced by reactive dicarbonyl compounds in a hyperglycemia environment. AGEs induce the expression of pro-inflammatory cytokines via the main receptor (RAGE), which has been documented to play a crucial role in the pathogenesis of diabetic peripheral neuropathy. Electroacupuncture (EA) has been reported to have a positive effect on paralgesia caused by various diseases, but the mechanism is unclear. In this study, we used high-fat-fed low-dose streptozotocin-induced rats as a model of type 2 diabetes (T2DM). Persistent metabolic disorder led to mechanical and thermal hyperalgesia, as well as intraepidermal nerve fiber density reduction and nerve demyelination. EA improved neurological hyperalgesia, decreased the pro-inflammatory cytokines, reduced the generation of AGEs and RAGE, and regulated the glyoxalase system in the EA group. Taken together, our study suggested that EA plays a role in the treatment of T2DM-induced DPN, and is probably related to the regulation of metabolism and the secondary influence on the GLO/AGE/RAGE axis.