Diseases of the peripheral nerves

Imbalance of bladder neurohomeostasis by Myosin 5a aggravates diabetic cystopathy

BACKGROUND

Diabetic cystopathy (DCP) is linked to bladder nerve conduction disorders, with diabetes-induced neuropathy impairing nerve signal transmission and causing bladder dysfunction. Myosin 5a, vital for neuronal transport, has been linked to neurological disorders, though its role in DCP remains unclear. The objective of this study was to investigate whether Myosin 5a plays a potential regulatory role in Diabetic Cystopathy.

METHODS

Bladder strips from diabetic rats were use to assess heightened responsiveness to external stimuli. Urodynamic assessments were conducted to track the progression of bladder voiding dysfunction over time, following streptozotocin (STZ) injection. Single-cell RNA-Seq mining was employed to identify associations between Myosin 5a and bladder overactivity. Cellular and tissue analyses were performed to determine the co-localization of Myosin 5a with neurotransmitter-related proteins. The impact of Myosin 5a knockdown on ChAT and SP expression in bladder neurons was also evaluated. Additionally, Myosin 5a-deficient DBA mice were studied for voiding function and sensitivity to stimuli. Student's t-test (two-tailed) or Mann-Whitney's U test analysis of variance was used to analyze the difference between groups.

RESULTS

Bladder strips from diabetic rats exhibit increased responsiveness to external stimuli, with urodynamic assessments showing a progressive decline in bladder function, culminating in overactivity by the fourth week post-STZ injection. Co-localization of Myosin 5a with neurotransmitter-related proteins was observed, and the knockdown of Myosin 5a in bladder neurons led to a significant reduction in ChAT and SP expression. Myosin 5a-deficient DBA mice exhibited abnormal voiding function and reduced sensitivity to stimuli, along with significant downregulation of SLC17A9. Single-cell RNA-Seq analysis revealed a significant link between Myosin 5a and bladder overactivity, with Myosin 5a expression escalating in tandem with the severity of bladder dysfunction.

CONCLUSIONS

Myosin 5a's dysregulation in diabetic rats may worsen bladder overactivity, suggesting its potential as a therapeutic target for diabetic OAB.

Advances in wearable electronics for monitoring human organs: Bridging external and internal health assessments

Devices used for diagnosing disease are often large, expensive, and require operation by trained professionals, which can result in delayed diagnosis and missed opportunities for timely treatment. However, wearable devices are being recognized as a new approach to overcoming these difficulties, as they are small, affordable, and easy to use. Recent advancements in wearable technology have made monitoring information possible from the surface of organs like the skin and eyes, enabling accurate diagnosis of the user's internal status. In this review, we categorize the body's organs into external (e.g., eyes, oral cavity, neck, and skin) and internal (e.g., heart, brain, lung, stomach, and bladder) organ systems and introduce recent developments in the materials and designs of wearable electronics, including electrochemical and electrophysiological sensors applied to each organ system. Further, we explore recent innovations in wearable electronics for monitoring of deep internal organs, such as the heart, brain, and nervous system, using ultrasound, electrical impedance tomography, and temporal interference stimulation. The review also addresses the current challenges in wearable technology and explores future directions to enhance the effectiveness and applicability of these devices in medical diagnostics. This paper establishes a framework for correlating the design and functionality of wearable electronics with the physiological characteristics and requirements of various organ systems.

Activation of P2X7R Inhibits Proliferation and Promotes the Migration and Differentiation of Schwann Cells

In the vertebrate nervous system, myelination of nerve fibers is crucial for the rapid propagation of action potentials through saltatory conduction. Schwann cells-the main glial cells and myelinating cells of the peripheral nervous system-play a crucial role in myelination. Following injury during the repair of peripheral nerve injuries, a significant amount of ATP is secreted. This ATP release acts to trigger the dedifferentiation of myelinating Schwann cells into repair cells, an essential step for axon regeneration. Subsequently, to restore nerve function, these repair cells undergo redifferentiate into myelinating Schwann cells. Except for P2X4R, purine receptors such as P2X7R also play a significant role in this process. In the current study, decreased expression of P2X7R was observed after sciatic nerve injury, followed by a gradual increase to the normal level of P2X7R expression. In vivo experiments showed that the activation of P2X7R using an agonist injection promoted remyelination, while the antagonists hindered remyelination. Further, in vitro experiments supported these findings and demonstrated that P2X7R activation inhibited the proliferation of Schwann cells, but it promoted the migration and differentiation of the Schwann cells. Remyelination is a prominent feature of the nerve regeneration. In the current study, it was proposed that the manipulation of P2X7R expression in Schwann cells after nerve injury could be effective in facilitating nerve remyelination.

Metal-induced autoimmunity in neurological disorders: A review of current understanding and future directions

Autoimmunity is a multifaceted disorder influenced by both genetic and environmental factors, and metal exposure has been implicated as a potential catalyst, especially in autoimmune diseases affecting the central nervous system. Notably, metals like mercury, lead, and aluminum exhibit well-established neurotoxic effects, yet the precise mechanisms by which they elicit autoimmune responses in susceptible individuals remain unclear. Recent studies propose that metal-induced autoimmunity may arise from direct toxic effects on immune cells and tissues, coupled with indirect impacts on the gut microbiome and the blood-brain barrier. These effects can activate self-reactive T cells, prompting the production of autoantibodies, inflammatory responses, and tissue damage. Diagnosing metal-induced autoimmunity proves challenging due to nonspecific symptoms and a lack of reliable biomarkers. Treatment typically involves chelation therapy to eliminate excess metals and immunomodulatory agents to suppress autoimmune responses. Prevention strategies include lifestyle adjustments to reduce metal exposure and avoiding occupational and environmental risks. Prognosis is generally favorable with proper treatment; however, untreated cases may lead to autoimmune disorder progression and irreversible organ damage, particularly in the brain. Future research aims to identify genetic and environmental risk factors, enhance diagnostic precision, and explore novel treatment approaches for improved prevention and management of this intricate and debilitating disease.

Prevalence and associated factors with peripheral neuropathies in the general population in the rural area of Adjohoun in Benin

BACKGROUND

Peripheral neuropathies (PN) are a group of neurological conditions related to damage to the peripheral nervous system. Due to their wide diversity, few studies in sub-Saharan Africa have explored their epidemiology in general population. Our objective was to study the prevalence and associated factors with PN in general population in Adjohoun in Benin.

METHODS

A cross-sectional study has been conducted from February to March 2019 and included people aged ≥ 18 years old living in Adjohoun, Benin. Following a screening phase for PN (using World Health Organization questionnaire for major neurological diseases), a neurologist made a diagnosis after in-depth clinical examinations completed in some cases by electroneuromyography. The EFNS (European Federation of Neurological Societies) 2010 criteria was used for chronic inflammatory demyelinating polyneuropathy diagnosis. Data such as age, occupation, consanguinity, alcohol consumption, diabetes, hypertension were collected. Association between independent variables and PN were investigated using multivariable logistic regression models.

RESULTS

In total, 1 655 participants were included, mean age 41.4 ± 16.7 years; 64.8 % are female. The overall prevalence of PN was 6.9 % (95 %CI: 5.7 %-8.2 %). The main types of PN were: polyneuropathies 4.8 % (95 %CI: 3.8 %-5.9 %); polyradiculoneuropathies 1.6 % (95 %CI: 1.0 %-2.2 %). Factors independently associated with PN were age ≥ 40 years (adjusted Odds Ratio aOR = 19.6; 95 %CI: 8.2-46.3), diabetes (aOR = 1.8; 95 %CI: 1.08-2.99) and hypertension (aOR = 1.6; 95 %CI: 1.02-2.5).

CONCLUSION

The prevalence of PN was high in the rural commune of Adjohoun in Benin. Actions on its modifiable associated factors such as diabetes and hypertension could help reduce the proportion of PN and their potential harmful consequences.

Exploring the Physicochemical, Electroactive, and Biodelivery Properties of Metal Nanoparticles on Peripheral Nerve Regeneration

Despite the advances in the regeneration/rehabilitation field of damaged tissues, the functional recovery of peripheral nerves (PNs), especially in a long gap injury, is considered a great medical challenge. Recent progress in nanomedicine has provided great hope for PN regeneration through the strategy of controlling cell behavior by metal nanoparticles individually or loaded on scaffolds/conduits. Despite the confirmed toxicity of metal nanoparticles due to long-term accumulation in nontarget tissues, they play a role in the damaged PN regeneration based on the topography modification of scaffolds/conduits, enhancing neurotrophic factor secretion, the ion flow improvement, and the regulation of electrical signals. Determining the fate of neural progenitor cells would be a major achievement in PN regeneration, which seems to be achievable by metal nanoparticles through altering cell vital approaches and controlling their functions. Therefore, in this literature, an attempt was made to provide an overview of the effective activities of metal nanoparticles on the PN regeneration, until the vital clues of the PN regeneration and how they are changed by metal nanoparticles are revealed to the researcher.

Recommended Musculoskeletal and Sports Ultrasound Terminology: A Delphi-Based Consensus Statement

OBJECTIVES

The current lack of agreement regarding standardized terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice, and research. This consensus was developed to provide a reference to improve clarity and consistency in communication.

METHODS

A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus which was defined as group level agreement >80%.

RESULTS

Content was organized into seven general topics including: 1) General Definitions, 2) Equipment and Transducer Manipulation, 3) Anatomic and Descriptive Terminology, 4) Pathology, 5) Procedural Terminology, 6) Image Labeling, and 7) Documentation. Terms and definitions which reached consensus agreement are presented herein.

CONCLUSIONS

The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients, and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

Formulated Curcumin Prevents Paclitaxel-Induced Peripheral Neuropathy through Reduction in Neuroinflammation by Modulation of α7 Nicotinic Acetylcholine Receptors

Paclitaxel is widely used in the treatment of various types of solid malignancies. Paclitaxel-induced peripheral neuropathy (PIPN) is often characterized by burning pain, cold, and mechanical allodynia in patients. Currently, specific pharmacological treatments against PIPN are lacking. Curcumin, a polyphenol of Curcuma longa, shows antioxidant, anti-inflammatory, and neuroprotective effects and has recently shown efficacy in the mitigation of various peripheral neuropathies. Here, we tested, for the first time, the therapeutic effect of 1.5% dietary curcumin and Meriva (a lecithin formulation of curcumin) in preventing the development of PIPN in C57BL/6J mice. Curcumin or Meriva treatment was initiated one week before injection of paclitaxel and continued throughout the study (21 days). Mechanical and cold sensitivity as well as locomotion/motivation were tested by the von Frey, acetone, and wheel-running tests, respectively. Additionally, sensory-nerve-action-potential (SNAP) amplitude by caudal-nerve electrical stimulation, electronic microscopy of the sciatic nerve, and inflammatory-protein quantification in DRG and the spinal cord were measured. Interestingly, a higher concentration of curcumin was observed in the spinal cord with the Meriva diet than the curcumin diet. Our results showed that paclitaxel-induced mechanical hypersensitivity was partially prevented by the curcumin diet but completely prevented by Meriva. Both the urcumin diet and the Meriva diet completely prevented cold hypersensitivity, the reduction in SNAP amplitude and reduced mitochondrial pathology in sciatic nerves observed in paclitaxel-treated mice. Paclitaxel-induced inflammation in the spinal cord was also prevented by the Meriva diet. In addition, an increase in α7 nAChRs mRNA, known for its anti-inflammatory effects, was also observed in the spinal cord with the Meriva diet in paclitaxel-treated mice. The use of the α7 nAChR antagonist and α7 nAChR KO mice showed, for the first time in vivo, that the anti-inflammatory effects of curcumin in peripheral neuropathy were mediated by these receptors. The results presented in this study represent an important advance in the understanding of the mechanism of action of curcumin in vivo. Taken together, our results show the therapeutic potential of curcumin in preventing the development of PIPN and further confirms the role of α7 nAChRs in the anti-inflammatory effects of curcumin.

Update on Toxic Neuropathies

Purpose of Review

Toxic neuropathies are an important preventable and treatable form of peripheral neuropathy. While many forms of toxic neuropathies have been recognized for decades, an updated review is provided to increase vigilant in this area of neurology. A literature review was conducted to gather recent information about toxic neuropathies, which included the causes, clinical findings, and treatment options in these conditions.

Recent Findings

Toxic neuropathies continue to cause significant morbidity throughout the world and the causative agents, particularly with regards to medications, do not appear to be diminishing. A wide variety of causes of toxic neuropathies exist, which include alcohol, industrial chemicals, biotoxins, and medications. Unfortunately, no breakthrough treatments have been developed and prevention and symptom management remain the standard of care.

Summary

A detailed medication, occupational and hobby exposure history is critical to identifying toxic neuropathies. Increased research is warranted to identify mechanisms of neurotoxic susceptibility and potential common pathomechanistic pathways for treatment across diverse toxic neuropathies.

Recommended musculoskeletal and sports ultrasound terminology: a Delphi-based consensus statement

The current lack of agreement regarding standardised terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice and research. This consensus was developed to provide a reference to improve clarity and consistency in communication. A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus, which was defined as group level agreement of >80%. Content was organised into seven general topics including: (1) general definitions, (2) equipment and transducer manipulation, (3) anatomical and descriptive terminology, (4) pathology, (5) procedural terminology, (6) image labelling and (7) documentation. Terms and definitions which reached consensus agreement are presented herein. The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

Abnormal photoplethysmography waveforms are associated with chemotherapy induced neuropathy

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-dependent adverse event of many chemotherapy agents that affects autonomic, motor, and sensory nerve fibers. The purpose of this study is to describe abnormal photoplethysmography waveforms (PPGs) in the setting of CIPN in cancer patients screened for peripheral arterial disease (PAD), which to our knowledge has not been previously described. Patients and methods: 147 patients who underwent vascular physiologic testing in evaluation for PAD with an ankle brachial index (ABI) or toe brachial index (TBI), segmental pressures, pulse volume recordings, and toe PPGs, in a tertiary cancer center's vascular lab between January 1, 2019 and January 31, 2021 were included in the study. Results: Odds ratio analysis demonstrates 3 times increased odds of abnormal PPGs in patients with PAD (OR 3.2256 95% CI 1.523-6.832, p=0.002), 7 times increased odds of abnormal PPGs in patients with CIPN (OR 7.802 95% CI 3.606-16.880, p<0.001), 9 times increased odds of abnormal PPGs in patients with both CIPN and PAD (9.895 95% CI 2.643-37.043, p=0.001), and 7 times increased odds of abnormal PPGs in patients with chemotherapy agent known to cause CIPN (7.821 95% CI 3.619-16.902, p<0.001). Logistic regression demonstrated that PAD (coefficient 1.171 std. error 0.383 wald 9.354 p=0.002), CIPN (coefficient 2.054 std. error 0.394 wald 27.227 p<0.001), and chemo agent known to cause CIPN (coefficient 2.057 std. error 0.393 wald 27.370 p<0.001) were all predictors of abnormal PPGs. Conclusions: CIPN had greater odds for abnormal PPGs than PAD. Additional larger studies are needed to assess if PPG analysis could be utilized to assess for early diagnosis of CIPN.

3D MR Neurography

High-resolution isotropic volumetric three-dimensional (3D) magnetic resonance neurography (MRN) techniques enable multiplanar depiction of peripheral nerves. In addition, 3D MRN provides anatomical and functional tissue characterization of different disease conditions affecting the peripheral nerves. In this review article, we summarize clinically relevant technical considerations of 3D MRN image acquisition and review clinical applications of 3D MRN to assess peripheral nerve diseases, such as entrapments, trauma, inflammatory or infectious neuropathies, and neoplasms.

Common Peroneal Nerve Injury in a Patient with COVID-19 Infection

This report described a 46-year man with the characteristic Computerized Tomography (CT) scan findings of Corona Virus Disease Infection 19 (COVID-19) who presented to the hospital with right ankle weakness three weeks after the pneumonitis. He had been initially hospitalized, complaining of fever, myalgia, cough, and dyspnea. Electromyogram (EMG) revealed obvious evidence of increased insertional activity (IA) and significant denervation potentials, including positive sharp waves (PSW) and fibrillation potentials, particularly in ankle dorsiflexor muscles. Moreover, no voluntary motor unit action potential (MUAP) was observed. Eventually, the patient was diagnosed with severe axonal mononeuropathy of the right CPN, which could be considered a rare complication of COVID-19.

Differential Diagnosis of Acquired and Hereditary Neuropathies in Children and Adolescents-Consensus-Based Practice Guidelines

Disorders of the peripheral nerves can be caused by a broad spectrum of acquired or hereditary aetiologies. The objective of these practice guidelines is to provide the reader with information about the differential diagnostic workup for a target-oriented diagnosis. Following an initiative of the German-speaking Society of Neuropaediatrics, delegates from 10 German societies dedicated to neuroscience worked in close co-operation to write this guideline. Applying the Delphi methodology, the authors carried out a formal consensus process to develop practice recommendations. These covered the important diagnostic steps both for acquired neuropathies (traumatic, infectious, inflammatory) and the spectrum of hereditary Charcot-Marie-Tooth (CMT) diseases. Some of our most important recommendations are that: (i) The indication for further diagnostics must be based on the patient's history and clinical findings; (ii) Potential toxic neuropathy also has to be considered; (iii) For focal and regional neuropathies of unknown aetiology, nerve sonography and MRI should be performed; and (iv) For demyelinated hereditary neuropathy, genetic diagnostics should first address PMP22 gene deletion: once that has been excluded, massive parallel sequencing including an analysis of relevant CMT-genes should be performed. This article contains a short version of the guidelines. The full-length text (in German) can be found at the Website of the "Arbeitsgemeinschaft der Wissenschftlichen Medizinischen Fachgesellschaften e.V. (AWMF), Germany.

Small Fiber Functionality in Patients with Diabetic Neuropathic Pain

OBJECTIVES

Diabetic neuropathic pain is associated with small fiber neuropathy. We aimed to assess the functionality of small fibers in patients with diabetes by using a practical method.

DESIGN

Patients with impaired glucose tolerance (IGT), diabetic neuropathic pain (DNP), type II diabetes mellitus without neuropathic pain, and healthy control were included. Axon-reflex flare responses were induced by the intradermal application of capsaicin and histamine at the distal leg. The associated flare characteristics (flare areas and flare intensities) were recorded by using Laser Speckle Contrast Analysis (LASCA). The pain and itch responses were rated while performing LASCA. To verify the structural properties of the small fibers, proximal and distal skin biopsies were performed.

RESULTS

DN4, MNSI, NRS, evoked-burning pain scores, and HbA1c levels were the highest in the DNP group. Compatible with length-dependent neuropathy, the distal skin PGP9.5-positive intraepidermal nerve fiber densities (IENFDs) were the lowest, whereas TRPV1-positive IENFDs were the highest in patients with DNP. The distal leg LASCA data showed hypo-functionality in both patients with IGT and DNP and association with disease severity.

CONCLUSION

There is an unmet need to practically assess the functionality of small fibers in patients with pain. In this study, a practical and objective method that does not need special expertise for the measurement of the functional properties of small fibers by using axon-flare responses is presented. The LASCA method could potentially facilitate a practical, quick (within 5 minutes), and very early diagnosis of small fiber hypo-functionality in both patients with IGT and DNP.

Imaging Review of Peripheral Nerve Injuries in Patients with COVID-19

With surging numbers of patients with coronavirus disease 2019 (COVID-19) throughout the world, neuromuscular complications and rehabilitation concerns are becoming more apparent. Peripheral nerve injury can occur in patients with COVID-19 secondary to postinfectious inflammatory neuropathy, prone positioning-related stretch and/or compression injury, systemic neuropathy, or nerve entrapment from hematoma. Imaging of peripheral nerves in patients with COVID-19 may help to characterize nerve abnormality, to identify site and severity of nerve damage, and to potentially elucidate mechanisms of injury, thereby aiding the medical diagnosis and decision-making process. This review article aims to provide a first comprehensive summary of the current knowledge of COVID-19 and peripheral nerve imaging.

What Every Neuropathologist Needs to Know: Peripheral Nerve Biopsy

Peripheral neuropathy is a common disorder with many possible etiologies including metabolic diseases, inflammatory conditions, infections, malignancy, inherited diseases, drugs, and toxins. In most instances, diagnosis and treatment plan can be established based on clinical presentation, family history, laboratory results, genetic testing, and electrophysiological studies. But in some situations, a peripheral nerve biopsy remains a valuable tool. This is especially true in patients with rapidly progressive disease, with atypical presentation or for whom other approaches fail to yield a definitive diagnosis. The pathologic examination starts with basic decisions about specimen triage. A few basic questions help to provide an initial framework for the assessment of a nerve biopsy-is the specimen adequate; are there inflammatory changes; are there vascular changes; is there amyloid; are there changes to axonal density and the Schwann cell-myelin-axon unit. In the appropriate context and with such an approach peripheral nerve biopsies can still represent a clinically helpful test.

Mini review: Lipids in Peripheral Nerve Disorders

Neurons are polarized cells whose fundamental functions are to receive, conduct and transmit signals. In bilateral animals, the nervous system is divided into the central (CNS) and peripheral (PNS) nervous system. The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body. Sensory axons can be up to 3 feet in length. Because of its long-reaching and complex structure, the peripheral nervous system (PNS) is exposed and vulnerable to many genetic, metabolic and environmental predispositions. Lipids and lipid intermediates are essential components of nerves. About 50 % of the brain dry weight consist of lipids, which makes it the second highest lipid rich tissue after adipose tissue. However, the role of lipids in neurological disorders in particular of the peripheral nerves is not well understood. This review aims to provide an overview about the role of lipids in the disorders of the PNS.

Alcohol-Induced Neuropathy in Chronic Alcoholism: Causes, Pathophysiology, Diagnosis, and Treatment Options

Purpose of the Review

Alcohol abuse causes a wide range of disorders that affect the nervous system. These include confusion, cerebellar ataxia, peripheral neuropathy, and cognitive impairment. Chronic and excessive alcohol consumption is the primary cause of peripheral neuropathy. It is worth noting that peripheral neuropathy has no reliable treatment due to the poor understanding of its pathology.

Recent Findings

Coasting is a major feature of alcoholic neuropathy, largely due to chronic alcohol abuse. Its major features are hyperalgesia, allodynia, and burning pain. Even though much research was done in this area, still we do not have a full understanding of the mechanism of alcoholic neuropathy. However, some theories have been proposed. These include direct or indirect effects of alcohol metabolites, impaired axonal transport, suppressed excitatory nerve pathway activity, or imbalance in neurotransmitters. Activation of spinal cord microglia, mGlu5 spinal cord receptors, and hypothalamic-pituitary-adrenal axis also seem to be implicated in the pathophysiology of this alcoholic neuropathy. The goal of treatment is to impede further damage to the peripheral nerves while also restoring their normal physiology. Alcohol abstinence, intake of balanced diets, and treatment with medications are suggested including benfotiamine, alpha-lipoic acid, acetyl-l-carnitine, vitamin E, methylcobalamin, myo-inositol, N-acetylcysteine, capsaicin, tricyclic antidepressants, or antiepileptic drugs.

Summary

This review focuses on the many pathways that play a role in the onset and development of alcohol-induced neuropathy, as well as present the possible treatment strategies of this disorder, providing insights into a further search of new treatment modalities.

Role of Oxidative Stress in Hepatic and Extrahepatic Dysfunctions during Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a pathology that contains a broad liver dysfunctions spectrum. These alterations span from noninflammatory isolated steatosis until nonalcoholic steatohepatitis (NASH), a more aggressive form of the disease characterized by steatosis, inflammatory status, and varying liver degrees fibrosis. NAFLD is the most prevalent chronic liver disease worldwide. The causes of NAFLD are diverse and include genetic and environmental factors. The presence of NASH is strongly associated with cirrhosis development and hepatocellular carcinoma, two conditions that require liver transplantation. The liver alterations during NAFLD are well described. Interestingly, this pathological condition also affects other critical tissues and organs, such as skeletal muscle and even the cardiovascular, renal, and nervous systems. Oxidative stress (OS) is a harmful state present in several chronic diseases, such as NAFLD. The purpose of this review is to describe hepatic and extrahepatic dysfunctions in NAFLD. We will also review the influence of OS on the physiopathological events that affect the critical function of the liver and peripheral tissues.

Key Developments in the Potential of Curcumin for the Treatment of Peripheral Neuropathies

Peripheral neuropathies (PN) can be triggered after metabolic diseases, traumatic peripheral nerve injury, genetic mutations, toxic substances, and/or inflammation. PN is a major clinical problem, affecting many patients and with few effective therapeutics. Recently, interest in natural dietary compounds, such as polyphenols, in human health has led to a great deal of research, especially in PN. Curcumin is a polyphenol extracted from the root of Curcuma longa. This molecule has long been used in Asian medicine for its anti-inflammatory, antibacterial, and antioxidant properties. However, like numerous polyphenols, curcumin has a very low bioavailability and a very fast metabolism. This review addresses multiple aspects of curcumin in PN, including bioavailability issues, new formulations, observations in animal behavioral tests, electrophysiological, histological, and molecular aspects, and clinical trials published to date. The, review covers in vitro and in vivo studies, with a special focus on the molecular mechanisms of curcumin (anti-inflammatory, antioxidant, anti-endoplasmic reticulum stress (anti-ER-stress), neuroprotection, and glial protection). This review provides for the first time an overview of curcumin in the treatment of PN. Finally, because PN are associated with numerous pathologies (e.g., cancers, diabetes, addiction, inflammatory disease...), this review is likely to interest a large audience.

Amyloid Proteins and Peripheral Neuropathy

Painful peripheral neuropathy affects millions of people worldwide. Peripheral neuropathy develops in patients with various diseases, including rare familial or acquired amyloid polyneuropathies, as well as some common diseases, including type 2 diabetes mellitus and several chronic inflammatory diseases. Intriguingly, these diseases share a histopathological feature-deposits of amyloid-forming proteins in tissues. Amyloid-forming proteins may cause tissue dysregulation and damage, including damage to nerves, and may be a common cause of neuropathy in these, and potentially other, diseases. Here, we will discuss how amyloid proteins contribute to peripheral neuropathy by reviewing the current understanding of pathogenic mechanisms in known inherited and acquired (usually rare) amyloid neuropathies. In addition, we will discuss the potential role of amyloid proteins in peripheral neuropathy in some common diseases, which are not (yet) considered as amyloid neuropathies. We conclude that there are many similarities in the molecular and cell biological defects caused by aggregation of the various amyloid proteins in these different diseases and propose a common pathogenic pathway for "peripheral amyloid neuropathies".

The safety of medications used to treat peripheral neuropathic pain, part 1 (antidepressants and antiepileptics): review of double-blind, placebo-controlled, randomized clinical trials

INTRODUCTION

Peripheral neuropathic pain is a highly disabling condition for patients and a challenge for neurologists and pain physicians. Although many drugs have been assessed in scientific studies, few have demonstrated a clear clinical efficacy against neuropathic pain. Moreover, the paucity of data regarding their safety raised the question on the benefit-risk ratio when used in patients experiencing peripheral neuropathies.

AREAS COVERED

The authors conducted a review of double-blind, placebo-controlled, randomized clinical trials to assess the safety of medications used to treat neuropathic pain. This first review was focused on antidepressant and antiepileptic medications. The aim was to provide an overview of the treatment-emergent adverse events (≥10%) and the serious adverse effects described in clinical trials.

EXPERT OPINION

Among antiepileptics and antidepressants, duloxetine appeared to have the most detailed safety for the treatment of peripheral neuropathic pain. Over all studies, the most commonly reported adverse effects were dizziness, drowsiness, nausea, and constipation. Only 20.0% of the included studies (N = 90) presented a good description of adverse effects that included a statistical comparison vers usa placebo group. Important methodological improvements must be made to improve the assessment of medication safety in future clinical trials.

Neural crest derived stem cells from dental pulp and tooth-associated stem cells for peripheral nerve regeneration

The peripheral nerve injuries, representing some of the most common types of traumatic lesions affecting the nervous system, are highly invalidating for the patients besides being a huge social burden. Although peripheral nervous system owns a higher regenerative capacity than does central nervous system, mostly depending on Schwann cells intervention in injury repair, several factors determine the extent of functional outcome after healing. Based on the injury type, different therapeutic approaches have been investigated so far. Nerve grafting and Schwann cell transplantation have represented the gold standard treatment for peripheral nerve injuries, however these approaches own limitations, such as scarce donor nerve availability and donor site morbidity. Cell based therapies might provide a suitable tool for peripheral nerve regeneration, in fact, the ability of different stem cell types to differentiate towards Schwann cells in combination with the use of different scaffolds have been widely investigated in animal models of peripheral nerve injuries in the last decade. Dental pulp is a promising cell source for regenerative medicine, because of the ease of isolation procedures, stem cell proliferation and multipotency abilities, which are due to the embryological origin from neural crest. In this article we review the literature concerning the application of tooth derived stem cell populations combined with different conduits to peripheral nerve injuries animal models, highlighting their regenerative contribution exerted through either glial differentiation and neuroprotective/neurotrophic effects on the host tissue.

Semi-automated volumetry of MRI serves as a biomarker in neuromuscular patients

BACKGROUND

Muscle MRI is of increasing importance for neuromuscular patients to detect changes in muscle volume, fat-infiltration, and edema. We developed a method for semi-automated segmentation of muscle MRI datasets.

METHODS

An active contour-evolution algorithm implemented within the ITK-SNAP software was used to segment T1-weighted MRI, and to quantify muscle volumes of neuromuscular patients (n = 65).

RESULTS

Semi-automated compared with manual segmentation was shown to be accurate and time-efficient. Muscle volumes and ratios of thigh/lower leg volume were lower in myopathy patients than in controls (P < .0001; P < .05). We found a decrease of lower leg muscle volume in neuropathy patients compared with controls (P < .01), which correlated with clinical parameters. In myopathy patients, muscle volume showed a positive correlation with muscle strength (r_left = 0.79, p_left  < .0001). Muscle volumes were independent of body mass index and age.

CONCLUSIONS

Our method allows for exact and time-efficient quantification of muscle volumes with possible use as a biomarker in neuromuscular patients.

A Comparative Review of Chemotherapy-Induced Peripheral Neuropathy in In Vivo and In Vitro Models

Chemotherapy-induced peripheral neuropathy (CIPN) is an adverse effect caused by several classes of widely used anticancer therapeutics. Chemotherapy-induced peripheral neuropathy frequently leads to dose reduction or discontinuation of chemotherapy regimens, and CIPN symptoms can persist long after completion of chemotherapy and severely diminish the quality of life of patients. Differences in the clinical presentation of CIPN by widely diverse classifications of anticancer agents have spawned multiple mechanistic hypotheses that seek to explain the pathogenesis of CIPN. Despite its clinical relevance, common occurrence, and extensive investigation, the pathophysiology of CIPN remains unclear. Furthermore, there is no unequivocal gold standard for the prevention and treatment of CIPN. Herein, we review in vivo and in vitro models of CIPN with a focus on histopathological changes and morphological features aimed at understanding the pathophysiology of CIPN and identify gaps requiring deeper exploration. An elucidation of the underlying mechanisms of CIPN is imperative to identify potential targets and approaches for prevention and treatment.

Metabolic and Non-Metabolic Peripheral Neuropathy: Is there a Place for Therapeutic Apheresis?

As the rate of obesity and the incidence of diabetes mellitus have been increasing, diabetic neuropathy has become the most common cause of peripheral neuropathy in developed countries. In addition, a variety of pathogenetically heterogeneous disorders can lead to impairment of the peripheral nervous system including amyloidosis, vitamin deficiencies, uremia and lipid disorders, alcohol abuse, autoimmune and infectious diseases as well as exposure to environmental toxins. We have noted that a combination of these disorders may aggravate the manifestations of peripheral diabetic neuropathy, an effect, which is most pronounced when metabolic and non-metabolic pathologies lead to cumulative damage. Current treatment options are limited and generally have unsatisfactory results in most patients. Therapeutic apheresis (INUSpherese®) allows the removal of metabolic, inflammatory, immunologic and environmental contributors to the disease process and may be an effective treatment option. We reviewed the developments in therapeutic apheresis for metabolic and non-metabolic peripheral neuropathy, including the current literature as well as data from our university diabetes center.

Can imaging be the new yardstick for diagnosing peripheral neuropathy?-a comparison between high resolution ultrasound and MR neurography with an approach to diagnosis

PURPOSE

Peripheral neuropathies are a group of disorders which affect the peripheral nervous system which have been conventionally diagnosed using electrodiagnostic studies. This study was carried out to assess the role of imaging in diagnosing peripheral mononeuropathy as exact anatomical localisation of the pathology is possible using high-resolution ultrasound and MR neurography, the modalities assessed in this study.

METHOD

A hospital-based prospective analytical study was carried out in a resource-limited setting on 180 peripheral nerves in 131 patients with symptoms of peripheral mononeuropathy after taking IRB approval. Each patient underwent high-resolution ultrasound examination and MR neurography, findings of which were then compared and statistically analysed assuming electrodiagnostic findings as the gold standard.

RESULTS

Overall, the diagnostic accuracy was highest for the proton density fat-saturated MR sequence (93.89%) followed by high-resolution ultrasound (80%). The sensitivity was highest for proton density fat-saturated sequence while the T1 MR sequence had the highest specificity. Combined diagnostic accuracy of both modalities was calculated to be 93.33% with a negative predictive value of 80%. High-resolution ultrasound and MRI equally detected the cases with nerve discontinuity, while neuromas were better identified on MRI.

CONCLUSION

With the advent of higher frequency probes and improved MR field strength, imaging of peripheral nerves is possible with better accuracy. Imaging assessment of nerves allows anatomical delineation with identification of exact site of involvement. This comparative study demonstrates the role of imaging in diagnosing peripheral nerve pathologies with the accuracy of MRI as high as 93.89% which may serve as an imaging gold standard. High-resolution ultrasound, being quicker, cost effective and a comparable accuracy of 80% can serve as a reliable screening tool. This study incorporates a larger study group and compares HRUS with MRI, taking NCV as gold standard, which has not been done in the preceding studies. With this study, we conclude that these two imaging modalities are not mutually exclusive. Rather, they complement each other and can be used in conjunction as an imaging yardstick for diagnosing peripheral neuropathies.

Monocarboxylate transporter 1 in Schwann cells contributes to maintenance of sensory nerve myelination during aging

Schwann cell (SC)-specific monocarboxylate transporter 1 (MCT1) knockout mice were generated by mating MCT1 ^f/f mice with myelin protein zero (P0)-Cre mice. P0-Cre^+/- , MCT1 ^f/f mice have no detectable early developmental defects, but develop hypomyelination and reduced conduction velocity in sensory, but not motor, peripheral nerves during maturation and aging. Furthermore, reduced mechanical sensitivity is evident in aged P0-Cre^+/- , MCT1 ^f/f mice. MCT1 deletion in SCs impairs both their glycolytic and mitochondrial functions, leading to altered lipid metabolism of triacylglycerides, diacylglycerides, and sphingomyelin, decreased expression of myelin-associated glycoprotein, and increased expression of c-Jun and p75-neurotrophin receptor, suggesting a regression of SCs to a less mature developmental state. Taken together, our results define the contribution of SC MCT1 to both SC metabolism and peripheral nerve maturation and aging.

Neural microphysiological systems for in vitro modeling of peripheral nervous system disorders

PNS disease pathology is diverse and underappreciated. Peripheral neuropathy may result in sensory, motor or autonomic nerve dysfunction and can be induced by metabolic dysfunction, inflammatory dysfunction, cytotoxic pharmaceuticals, rare hereditary disorders or may be idiopathic. Current preclinical PNS disease research relies heavily on the use of rodent models. In vivo methods are effective but too time-consuming and expensive for high-throughput experimentation. Conventional in vitro methods can be performed with high throughput but lack the biological complexity necessary to directly model in vivo nerve structure and function. In this review, we survey in vitro PNS model systems and propose that 3D-bioengineered microphysiological nerve tissue can improve in vitro–in vivo extrapolation and expand the capabilities of in vitro PNS disease modeling.

Post-9/11 Peripheral Neuropathy Symptoms among World Trade Center-Exposed Firefighters and Emergency Medical Service Workers

Peripheral neuropathy can result from numerous conditions including metabolic disorders, inflammatory disease, or exposure to environmental or biological toxins. We analyzed questionnaire data from 9239 Fire Department of the City of New York (FDNY) World Trade Center (WTC)-exposed firefighters and emergency medical service workers (EMS) to evaluate the association between work at the WTC site and subsequent peripheral neuropathy symptoms using the validated Diabetic Neuropathy Symptom (DNS) score. We grouped the population into an "Indicated" group with conditions known to be associated with paresthesia (N = 2059) and a "Non-Indicated" group without conditions known to be associated (N = 7180). The level of WTC exposure was categorized by time of arrival to the WTC. Overall, 25% of workers aged 40 and older reported peripheral neuropathy symptoms: 30.6% in the Indicated and 23.8% in the Non-Indicated groups, respectively. Multivariable logistic models performed on the Non-Indicated group, and on the Non-Indicated in comparison with non-WTC exposed National Health and Nutrition Examination Survey (NHANES), found that the highest level of WTC-exposure was significantly associated with DNS positive outcomes, after controlling for potential confounders. In conclusion, this study suggests that symptoms of peripheral neuropathy and paresthesias are common and are associated with WTC-exposure intensity.

Fluorescence-Based Analysis of Noncanonical Functions of Aminoacyl-tRNA Synthetase-Interacting Multifunctional Proteins (AIMPs) in Peripheral Nerves

Aminoacyl-tRNA synthetase-interacting multifunctional proteins (AIMPs) are auxiliary factors involved in protein synthesis related to aminoacyl-tRNA synthetases (ARSs). AIMPs, which are well known as nonenzymatic factors, include AIMP1/p43, AIMP2/p38, and AIMP3/p18. The canonical functions of AIMPs include not only protein synthesis via multisynthetase complexes but also maintenance of the structural stability of these complexes. Several recent studies have demonstrated nontypical (noncanonical) functions of AIMPs, such as roles in apoptosis, inflammatory processes, DNA repair, and so on. However, these noncanonical functions of AIMPs have not been studied in peripheral nerves related to motor and sensory functions. Peripheral nerves include two types of structures: peripheral axons and Schwann cells. The myelin sheath formed by Schwann cells produces saltatory conduction, and these rapid electrical signals control motor and sensory functioning in the service of survival in mammals. Schwann cells play roles not only in myelin sheath formation but also as modulators of nerve degeneration and regeneration. Therefore, it is important to identify the main functions of Schwann cells in peripheral nerves. Here, using immunofluorescence technique, we demonstrated that AIMPs are essential morphological indicators of peripheral nerve degeneration, and their actions are limited to peripheral nerves and not the dorsal root ganglion and the ventral horn of the spinal cord.

NONRATT021972 long-noncoding RNA: A promising lncRNA in diabetes-related diseases

Diabetes mellitus (DM) is a principal health problem with increasing incidence worldwide. It can be associated with various systemic diseases. Long non-coding RNA (lncRNA), a member of non-coding RNA has been newly linked with various human diseases. Recent evidence from animal experiments has shown that the incidence and development of type 2 diabetes are contributed by the atypical expression of lncRNA in which the biomarker with capable clinical potential was lncRNA NONRATT021972. In this review, we demonstrated the numerous functions of NONRATT021972 in different diabetes-related diseases including diabetic neuropathy, diabetic cardiac autonomic neuropathy, myocardial ischemia, and hepatic glucokinase dysfunction. The emerging evidence shows that the role of NONRATT021972 in diabetic-related disease is novel and therapeutic. These results direct us to conclude that NONRATT021972 is a potential diagnostic and future targeted therapy for diabetes-associated diseases.