Alcoholic neuropathy: possible mechanisms and future treatment possibilities

Identification of ethanol analgesia quantitative trait loci and candidate genes in BXD recombinant inbred mouse lines

Alcohol consumption produces acute analgesic effects, and people experiencing pain conditions may drink alcohol to alleviate discomfort. However, tolerance to the analgesic properties of alcohol could prompt escalating consumption and dependence. Both nociception and alcohol-induced analgesia are under significant genetic control. Understanding the genetic architecture of these processes could inform better treatment options for people with pain conditions. This study aims to identify quantitative trait loci (QTL) driving variation in ethanol-induced analgesia across BXD recombinant inbred mouse lines. Male and female mice from 62 BXD strains received ethanol or saline oral gavage for five days and were tested for hot plate (HP) latency at baseline, Day 1, and Day 5. QTL mapping of HP phenotypes identified a significant provisional QTL on chromosome 17 for Day 1 HP latency in mice receiving ethanol. An additional highly suggestive QTL was present on chromosome 9 for the difference in pre- and post-ethanol thermal nociception. Candidate genes within QTL support intervals were provisionally identified using HP phenotypic correlations to transcriptomic database, expression QTL analysis, and other bioinformatics inquiries. The combined behavioral and bioinformatic analyses yielded strong ethanol analgesia candidate genes, specifically Myo6. Thus, the results of this genetic study of ethanol-induced analgesia in BXD mouse strains may contribute significantly to our understanding of the molecular basis for individual variation in the analgesic response to acute ethanol.

Alcohol-related peripheral neuropathy: Clinico-neurophysiological characteristics and diagnostic utility of the neuropathy symptoms score and the neuropathy impairment score

Alcohol overconsumption is well known to cause damage to the peripheral nervous system, affecting both small and large nerve fibers. The aim of this descriptive study was to investigate peripheral nerve damage, and to correlate clinical, epidemiological and neurophysiological findings, in patients diagnosed with Alcohol Use Disorder (AUD). Ninety alcohol-dependent subjects on inpatient basis were enrolled in this prospective study over a 3-year period. Every subject was assessed by the Neuropathy Symptoms Score (NSS) questionnaire and the Neuropathy Impairment Score (NIS) clinical examination grading scale, followed by Nerve Conduction Studies, Quantitative Sensory Testing and Sympathetic Skin Response (SSR) testing. Peripheral neuropathy was diagnosed in 54 subjects (60%), by abnormal neurophysiological tests and presence of clinical signs or symptoms. Among them, pure large fiber neuropathy (LFN) was found in 18 subjects, pure small fiber neuropathy (SFN) in 12 subjects, and both large and small fiber neuropathy was diagnosed in 24 subjects. Using linear regression, we found that higher NSS and NIS scores correlated with lower amplitudes of the sural sensory nerve action potential and of the SSR. We also found a significant longer duration of alcohol abuse in subjects with neuropathy, using Student's t-test (p = 0.024). Additionally, applying NIS abnormal cut-off score ≥4, using ROC analysis, we predicted the majority of subjects with LFN, confirming 95.23% sensitivity and 93.75% specificity. Our study confirmed that peripheral neuropathy involving large and small nerve fibers, with a symmetrical length-dependent pattern, is common between patients with AUD and related to the duration of the disorder. We suggest that NSS and NIS scales could be used for the assessment of neuropathy in clinical practice, when the essential neurophysiological testing is not available.

Alcohol Use Disorder and Chronic Pain: An Overlooked Epidemic

Alcohol use disorder (AUD) and chronic pain disorders are pervasive, multifaceted medical conditions that often co-occur. However, their comorbidity is often overlooked, despite its prevalence and clinical relevance. Individuals with AUD are more likely to experience chronic pain than the general population. Conversely, individuals with chronic pain commonly alleviate their pain with alcohol, which may escalate into AUD. This narrative review discusses the intricate relationship between AUD and chronic pain. Based on the literature available, the authors present a theoretical model explaining the reciprocal relationship between AUD and chronic pain across alcohol intoxication and withdrawal. They propose that the use of alcohol for analgesia rapidly gives way to acute tolerance, triggering the need for higher levels of alcohol consumption. Attempts at abstinence lead to alcohol withdrawal syndrome and hyperalgesia, increasing the risk of relapse. Chronic neurobiological changes lead to preoccupation with pain and cravings for alcohol, further entrenching both conditions. To stimulate research in this area, the authors review methodologies to improve the assessment of pain in AUD studies, including self-report and psychophysical methods. Further, they discuss pharmacotherapies and psychotherapies that may target both conditions, potentially improving both AUD and chronic pain outcomes simultaneously. Finally, the authors emphasize the need to manage both conditions concurrently, and encourage both the scientific community and clinicians to ensure that these intertwined conditions are not overlooked given their clinical significance.

Decrypting the multifaceted peripheral neuropathy based on molecular pathology and therapeutics: a comprehensive review

CONTEXT

Peripheral neuropathy (PN) is a multifaceted complication characterized by nerve damage due to oxidative stress, inflammatory mediators, and dysregulated metabolic processes. Early PN manifests as sensory changes that develop progressively in a "stocking and glove" pattern.

METHODS AND MECHANISMS

A thorough review of literature has been done to find the molecular pathology, clinical trials that have been conducted to screen the effects of different drugs, current treatments and novel approaches used in PN therapy. Diabetic neuropathy occurs due to altered protein kinase C activity, elevated polyol pathway activity in neurons, and Schwann cells-induced hyperglycemia. Other causes involve chemotherapy exposure, autoimmune ailments, and chronic ethanol intake.

CONCLUSION

Symptomatic treatments for neuropathic pain include use of tricyclic antidepressants, anticonvulsants, and acetyl-L-carnitine. Patients will have new hope if clinicians focus on novel therapies including gene therapy, neuromodulation techniques, and cannabidiol as an alternative to traditional medications, as management is still not ideal.

New-Onset Wrist Drop After a Night of Drinking: A Case Report

This case report highlights the clinical approach to evaluating a patient with substance use disorder presenting with a sudden onset of peripheral neuropathy in the left hand. Our patient had significant cardiovascular risk factors, which further broadened the differential diagnosis beyond common causes of mononeuropathy. The use of detailed and appropriate clinical history, physical examination, and careful selection of relevant laboratory and radiological tests was instrumental in ruling out multiple medical differential diagnoses, including common mononeuropathies and life-threatening ones, such as cerebrovascular accidents, which facilitated the involvement of necessary consults while also treating both the presenting medical complication and underlying severe alcohol use disorder with additional efforts at relapse prevention.

Pain Intensity, Pain-Related Anxiety, and Hazardous Drinking Among Individuals With PTSD

OBJECTIVE

Evidence suggests that pain intensity may be indirectly linked to hazardous drinking and PTSD symptom severity via pain-related anxiety. The goal of this analysis was to test the hypotheses in a population with PTSD symptoms that pain intensity would be positively and indirectly associated with hazardous drinking, alcohol dependence, alcohol-related problems, and PTSD symptom severity via pain-related anxiety.

METHODS

Heavy drinkers with probable PTSD were recruited via Qualtrics panels (N = 371, 53% Female, Mage = 39.68, SD = 10.86). Linear regression and conditional process models were conducted to examine indirect associations between pain intensity and primary outcomes via pain-related anxiety.

RESULTS

Pain intensity was found to be indirectly associated with hazardous drinking, alcohol dependence, alcohol-related problems, and PTSD symptom severity via greater pain-related anxiety.

CONCLUSION

These initial findings suggest that pain-related anxiety may play an important role in relations between the experience of pain and hazardous patterns of alcohol consumption among individuals with probable PTSD. Future research is needed to determine the temporal nature of these associations and to examine the potential utility of treatments that address pain-related anxiety in the context of comorbid pain, PTSD, and hazardous drinking.

Visual memory and alcohol use in a middle-aged birth cohort

Light and moderate alcohol use has been reported to be associated with both impaired and enhanced cognition. The purpose of this study was to explore whether there was a linear relationship between visual memory and alcohol consumption in males and females in a large middle-aged birth cohort population in cross-sectional and longitudinal settings. Data were collected from 5585 participants completing 31-year (1997-1998) and 46-year (2012-2014) follow-ups including Paired Associate Learning (PAL) test at 46-years follow-up. The participants were originally from 12,231 study population of the Northern Finland Birth Cohort 1966 (NFBC1966). The PAL test was conducted to assess visual memory. Reported alcohol use was measured as total daily use of alcohol, beer, wine, and spirits converted into grams and as frequency and amount of use of beer, wine, and spirits. The total daily alcohol use was not associated with reduced visual memory. The frequency of use of beer and wine in males was associated with better visual memory in cross-sectional and longitudinal settings. Using six or more servings of spirits was associated with worse visual memory in males in cross-sectional and longitudinal settings. Using six or more servings of spirits was associated with worse visual memory in males in cross-sectional and longitudinal setting. The study suggested a lack of a linear association between drinking and visual memory in the middle-aged population.

Nutritional status changes in the treatment of substance use disorder: Relationship with substance craving

Tailored nutrition counseling enhances the efficacy of routine treatment for substance (alcohol/drugs) use disorders (SUDs). For this purpose, it is important to understand the current nutritional status of addicts and the changes in their nutritional status during the treatment process. Furthermore, the consumption of sweets to manage substance cravings is common among people with SUDs, but the evidence for the effectiveness of this practice is limited and conflicting. We therefore hypothesized SUD treatment would be associated with increases in appetite, nutrient intake, and anthropometric measurements in addicts, and that these changes, including changes in sweet consumption, would not be associated with decreased substance craving. Data for this prospective observational study were collected from 38 adult male patients who completed 21 days of inpatient SUD treatment. During the treatment, the participants' levels of appetite (P < 1.0 × 10-4), the frequency of main meals (P < 1.0 × 10-4), intake of macro- and micronutrients (P < .05 for each), and anthropometric measurements (P ≤ 5.9 × 10-4), significantly increased. Furthermore, it was found that the patients had a significant increase in sweets craving (P < 1.0 × 10-4) and sweets consumption (P = 1.2 × 10-3) during treatment. However, there was no significant difference between the individuals whose craving decreased and those whose craving did not decrease at the end of the treatment (P > .05 for both). The findings suggest the need to offer dietary counseling to individuals undergoing inpatient SUD treatment, given the substantial changes in nutritional status, and that increased consumption of sweets is not an effective strategy to reduce substance craving.

The Usefulness of Deep Tendon Reflexes in the Diagnosis of Lumbar Spine Diseases: A Narrative Review

The deep tendon reflex (DTR) is a more objective indicator than sensory and muscle assessments for lumbar spine disorders. Further, unlike sensory and muscle assessments that require patient cooperation, the DTR can be assessed even in patients with impaired consciousness or cognition. Therefore, DTR assessment with a hammer is an essential neurological test for lumbar spinal diseases. However, despite the usefulness of DTR assessment, few reports have described the significance of increased, diminished, or absent deep lower extremity reflexes in lumbar spine diseases. This review outlines the history of DTR of the lower limbs and describes the techniques, evaluation, and interpretation of DTR for the diagnosis of lumbar spine diseases. The patellar tendon reflex (PTR) was the first parameter of lower extremity DTR identified to have clinical usefulness, followed by the Achilles tendon reflex (ATR), pathological reflexes (Babinski reflex), and reflex enhancement (Jendrassik maneuver). They have now become an integral part of clinical examination. To determine whether an increase or decrease in DTR is pathological, it is necessary to determine left-right differences, differences between the upper and lower extremities, and the overall balance of the limb. There are several critical limitations and pitfalls in interpreting DTRs for lumbar spine diseases. Attention should be paid to examiner and patient factors that make the DTR assessment less objective. When there is a discrepancy between clinical and imaging findings and the level of the lumbosacral nerve root disorder is difficult to diagnose, the presence of a lumbosacral transitional vertebra, nerve root malformation, or furcal nerve should be considered. In addition, assessing the DTR after the gait loading test and standing extension loading test, which induce lumbosacral neuropathy, will help provide a rationale for the diagnosis.

Alcohol use and the pain system

The World Health Organization's epidemiological data from 2016 revealed that while 57% of the global population aged 15 years or older had abstained from drinking alcohol in the previous year, more than half of the population in the Americas, Europe, and Western Pacific consumed alcohol. The spectrum of alcohol use behavior is broad: low-risk use (sensible and in moderation), at-risk use (e.g., binge drinking), harmful use (misuse) and dependence (alcoholism; addiction; alcohol use disorder). The at-risk use and misuse of alcohol is associated with the transition to dependence, as well as many damaging health outcomes and preventable causes of premature death. Recent conceptualizations of alcohol dependence posit that the subjective experience of pain may be a significant contributing factor in the transition across the spectrum of alcohol use behavior. This narrative review summarizes the effects of alcohol at all levels of the pain system. The pain system includes nociceptors as sensory indicators of potentially dangerous stimuli and tissue damage (nociception), spinal circuits mediating defensive reflexes, and most importantly, the supraspinal circuits mediating nocifensive behaviors and the perception of pain. Although the functional importance of pain is to protect from injury and further or future damage, chronic pain may emerge despite the recovery from, and absence of, biological damage (i.e., in the absence of nociception). Like other biological perceptual systems, pain is a construction contingent on sensory information and a history of individual experiences (i.e., learning and memory). Neuroadaptations and brain plasticity underlying learning and memory and other basic physiological functions can also result in pathological conditions such as chronic pain and addiction. Moreover, the negative affective/emotional aspect of pain perception provides embodied and motivational components that may play a substantial role in the transition from alcohol use to dependence.

Increased Incidence of Depression and Chronic Pain in Traumatic Spinal Cord Injury Patients With Pre-Injury Alcohol Use Disorder: Longitudinal Analysis of Insurance Claim Database

Alcohol use disorder (AUD) increases risk of traumatic spinal cord injury (SCI) and is associated with depression, anxiety, and chronic pain. Given that these neuropsychiatric morbidities are frequently observed in SCI patients, the effects of pre-injury AUD on risk of depression, anxiety, or chronic pain were analyzed using an insurance claim database. Of 10,591 traumatic SCI patients, 507 had AUD-associated claims in a 12-month period before injury. Those AUD-positive SCI patients showed distinct demographic characteristics, including greater representation of men, younger age, more comorbidities, lower coverage by commercial insurance, and more cervical-level injuries. The AUD group also showed elevated pre-injury comorbidity of depression, anxiety, and chronic pain. However, multi-regression analysis revealed an increased odds ratio (OR) of de novo diagnosis of post-SCI depression in AUD patients 6 months (1.671; 95% confidence interval [CI]: 1.124, 2.483) and 1 year post-injury (1.511; 95% CI: 1.071, 2.131). The OR of de novo post-SCI anxiety was unaffected by pre-injury AUD. Finally, 1 year after SCI, pre-injury AUD increased the OR of de novo diagnosis of post-injury chronic pain (1.545; 95% CI: 1.223, 1.951). Thus, pre-injury AUD may be a risk factor for development of depression and chronic pain after traumatic SCI.

Extrahepatic Health Effects of Alcohol Use and Alcohol-associated Liver Disease

PURPOSE

Alcohol use disorder (AUD) is a growing public health concern and an important contributor to global morbidity and mortality. While the hepatotoxic effects of alcohol are well known, the adverse effects of alcohol are manifested in almost every organ system. With the growing public health impact of AUD, the aim of this narrative review is to highlight the epidemiology and burden of AUD and its association with extrahepatic diseases including malignancy and disorders of the gastrointestinal (GI), cardiovascular, immunologic, neurologic, endocrine, and hematologic systems.

METHODS

A narrative review of the literature was performed to identify studies addressing the epidemiology, pathophysiology, clinical manifestations, and therapy of extrahepatic health manifestations of alcohol use.

FINDINGS

In the United States, an estimated 14.5 million people have AUD and approximately 88,000 adults die yearly due to alcohol-related causes. The consumption of alcohol and AUD is associated with injuries, violence, cancers, nonmalignant conditions of the GI system, infections, effects on the cardiovascular system, and neurodegenerative diseases. These conditions contribute to the increased mortality associated with AUD and are burdensome to patients and caregivers.

IMPLICATIONS

Increased awareness of the extrahepatic manifestations of AUD, screening for AUD using validated screening tools, such as the Alcohol Use Disorders Identification Test-Concise (AUDIT-C) score, and offering evidence-based interventions to patients with AUD is imperative to reduce the public health burden of AUD. Although historically controversial, recent evidence suggests that any level of alcohol consumption can have negative health consequences. Further research is warranted to determine if any amount of alcohol is safe for consumption. Public health efforts are warranted to help curtail the growing burden of AUD.

Alcohol use severity in relation to pain severity and interference among latinx adults with current pain who smoke cigarettes

Limited research has focused expressly on dual tobacco-alcohol use among the Latinx population. Latinx individuals who smoke represent a tobacco health disparities group and evince elevated rates of pain problems and symptoms. Prior research has consistently linked pain problems and severity to smoking and alcohol prevalence, maintenance, and behavior. Accordingly, the current study sought to build from the limited work that exists among Latinx persons who smoke and evaluate the role of alcohol use severity in terms of pain severity and interference. The current sample consisted of 228 adult Latinx daily cigarette smokers (Mage = 34.95 years; SD = 8.58; 39.0% female) who endorsed current pain. Results indicated that elevated alcohol use problems were associated with greater levels of pain severity (R2 = 0.06) and interference (R2 = 0.06). The present findings suggest that there may be utility in clinical screening for alcohol use problems among Latinx persons who smoke to offset pain problems among this high-risk group.

Neural and Psychosocial Mechanisms Underlying Alcohol Use and Pain Interactions: Overview of Current Evidence and Future Directions

Purpose of Review

A growing body of research indicates bidirectional associations between alcohol use and pain. In this review, we highlight common neural and psychosocial mechanisms underlying pain and alcohol use and identify current gaps in the literature regarding alcohol/pain interactions. We also suggest future directions for the field moving forward, including more nuanced conceptualization of alcohol's negative reinforcing effects in the context of pain, broader use of clinically-relevant experimental pain induction modalities, and characterization of age, biological sex, gender, race, and ethnicity as moderators of pain/alcohol interactions.

Recent Findings

Acute alcohol intake has analgesic and negative-reinforcing effects in the context of pain, and chronic heavy alcohol use appears to increase risk for development of chronic pain. At the same time, pain, both acute and chronic, acts as a proximal antecedent for alcohol use and is associated with relapse risk for individuals in recovery from alcohol use disorder.

Summary

Although the links between alcohol use and pain are increasingly appreciated, significant gaps in understanding remain and systematic study of alcohol/pain interactions at all levels, including basic, preclinical, translational, and interventional, is needed.

Association between lifestyle habits and glaucoma incidence: a retrospective cohort study

BACKGROUND/OBJECTIVES

Although lifestyle habits may represent modifiable risk factors of glaucoma, the association between lifestyle factors and glaucoma is not well understood. The aim of this study was to investigate the association between lifestyle habits and the development of glaucoma.

SUBJECTS/METHODS

Participants who underwent health check-ups from 2005 to 2020 using a large-scale administrative claims database in Japan were included in the study. Cox regression analyses were performed where glaucoma development was regressed on the lifestyle (body mass index, current smoking, frequency and amount of alcohol consumption, eating habits, exercise habits and quality of sleep), age, sex, hypertension, diabetes mellitus and dyslipidaemia.

RESULTS

Among the 3,110,743 eligible individuals, 39,975 developed glaucoma during the mean follow-up of 2058 days. Factors associated with increased risk of glaucoma were overweight/obese (vs. moderate weight: hazard ratio, 1.04 [95% confidence interval, 1.02-1.07]), alcohol consumption of 2.5-4.9 units/day, 5-7.4 units/day, and ≥7.5 units/day (vs. <2.5 units/day: 1.05 [1.02-1.08], 1.05 [1.01-1.08] and 1.06 [1.01-1.12], respectively), skipping breakfast (1.14 [1.10-1.17]), late dinner (1.05 [1.03-1.08]) and daily walking of 1 h (1.14 [1.11-1.16]). Factors associated with decreased risk of glaucoma were daily alcohol consumption (vs. rarely: 0.94 [0.91-0.97]) and regular exercise (0.92 [0.90-0.95]).

CONCLUSIONS

Moderate body mass index, having breakfast, avoiding late dinner, limiting alcohol intake to <2.5 units/day, and regular exercise were associated with a reduced risk of developing glaucoma in the Japanese population. These findings may be useful for promoting glaucoma prophylaxis.

Analysis of Japanese nationwide health datasets: association between lifestyle habits and prevalence of neuropathic pain and fibromyalgia with reference to dementia-related diseases and Parkinson's disease

OBJECTIVES

Chronic pain is defined as pain that persists or recurs for more than 3 months. This study focuses on neuropathic pain (NP) and fibromyalgia (FM) which are chronic pain states, and aims to identify lifestyle habits associated with their prevalence. Other neurological disorders are also analyzed as references.

METHODS

Association between the variable referring to disease prevalence (number of claims for reimbursement of marker drugs) and the variable for lifestyle habits/health examination results (collected from insured individuals aged 40-74 years) was determined by analyzing Japanese nationwide datasets, which were collected in 2018 and aggregated by prefecture. Pregabalin, donepezil, and levodopa were used as marker drugs for the chronic pain states, dementia-related diseases (Alzheimer's disease and Lewy body dementia) and Parkinson's disease (PD), respectively. Pearson's correlation analysis and multiple linear regression analysis were conducted.

RESULTS

Variables showing correlation coefficient (|r|)>0.5 were put into the multiple linear regression. Exercise habits (ꞵ=-0.3182), smoking habits (0.3218), daily drinking (0.2683), and alanine aminotransferase>51 U/L (0.2309) were finally incorporated in the equation for pregabalin (R 2=0.7268). Walking speed (-0.4543) and daily drinking (0.5077) were incorporated in the equation for donepezil (R 2=0.5718).

CONCLUSIONS

The prevalence of chronic pain states is associated with lifestyle habits, just like the dementia-related diseases. Exercise in daily life is negatively associated with the prevalence of the chronic pain states, although excessive alcohol drinking, smoking, and high serum ALT are positively associated with it. The prevalence of PD seems less associated with lifestyle habits.

Associations of smoking and alcohol consumption with the development of open angle glaucoma: a retrospective cohort study

OBJECTIVES

To investigate the associations of alcohol consumption and smoking with the development of perimetric glaucoma in patients with suspected glaucoma.

DESIGN

A retrospective cohort study of patients suspected to have glaucoma enrolled in the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES).

SETTING

Three tertiary glaucoma centres in the USA.

PARTICIPANTS

825 eyes of 610 patients with glaucoma suspect eyes with normal visual fields (VF) at baseline were followed over an average of 9 years from the DIGS and ADAGES studies.

OUTCOME MEASURES

Development of glaucoma was defined as occurrence of three consecutive abnormal VF tests during follow-up. Univariable and multivariable Cox regression models were used to investigate lifestyle-related factors associated with development of VF loss over time.

RESULTS

VF tests were abnormal three times in a row in 235 (28.5%) eyes. Alcohol consumption was associated with a higher risk of developing glaucoma (HR 1.57, 95% CI 1.03 to 2.38, p=0.037). In men, the risk of developing glaucoma in alcohol drinkers (HR 1.92, 95% CI 1.00 to 3.68, p=0.048) was greater than non-alcohol drinkers. In individuals of African descent, the risk of developing glaucoma in alcohol drinkers (HR 1.79, 95% CI 1.02 to 3.15, p=0.043) was greater than non-alcohol drinkers. Age was a modifier of the relationship between smoking and glaucomatous VF defects (p=0.048). The risk of developing glaucoma in smokers (HR 1.73, 95% CI 1.10 to 2.72, p=0.019) was greater than never smokers after adjustment for confounding factors in older patients (age >61 years).

CONCLUSION

Alcohol consumption was associated with an increased risk of developing glaucoma, particularly in men and individuals of African descent. The risk of developing glaucoma among smokers suspected of having glaucoma was influenced by age, with older individuals having a higher risk than younger people.

TRIAL REGISTRATION NUMBER

NCT00221897 and NCT00221923.

Charcot Neuroarthropathy of the Foot and Ankle in the Acute Setting: An Illustrative Case Report and Targeted Review

Charcot neuroarthropathy (CN) is a rare but serious sequela of diabetes and other diseases that cause peripheral neuropathy. It is most commonly characterized by degeneration of the foot and/or ankle joints leading to progressive deformity and altered weight-bearing. If left untreated, the deformities of CN lead to ulceration, infection, amputation, and even death. Because of the associated peripheral neuropathy and proprioception deficits that accompany CN, patients typically do not perceive the onset of joint destruction. Moreover, in the hands of the untrained clinician, the initial presentation of CN can easily be mistaken for infection, osteoarthritis, gout, or inflammatory arthropathy. Misdiagnosis can lead to the aforementioned serious sequelae of CN. Thus, an early accurate diagnosis and off-loading of the involved extremity, followed by prompt referral to a specialist trained in the care of CN are crucial to prevent the late-term sequelae of the disease. The purpose of this article was to create an opportunity for enhanced understanding between orthopedic surgeons and emergency physicians, to improve patient care through the optimization of diagnosis and early management of CN in the emergent setting.

Somatosensory profiling of patients undergoing alcohol withdrawal: Do neuropathic pain and sensory loss represent a problem?

INTRODUCTION

Chronic heavy alcohol use is known to cause neurological complications such as peripheral neuropathy. Concerning the pathophysiology, few sural nerve and skin biopsy studies showed that small fibers might be selectively vulnerable to degeneration in alcohol-related peripheral neuropathy. Pain has rarely been properly evaluated in this pathology. The present study aims at assessing pain intensity, potential neuropathic characteristics as well as the functionality of both small and large nerve sensitive fibers.

METHODS

In this observational study, 27 consecutive adult patients, hospitalized for alcohol withdrawal and 13 healthy controls were recruited. All the participants underwent a quantitative sensory testing (QST) according to the standardized protocol of the German Research Network Neuropathic Pain, a neurological examination and filled standardized questionnaires assessing alcohol consumption and dependence as well as pain characteristics and psychological comorbidities.

RESULTS

Nearly half of the patients (13/27) reported pain. Yet, pain intensity was weak, leading to a low interference with daily life, and its characteristics did not support a neuropathic component. A functional impairment of small nerve fibers was frequently described, with thermal hypoesthesia observed in 52% of patients. Patients with a higher alcohol consumption over the last 2 years showed a greater impairment of small fiber function.

DISCUSSION

Patients report pain but it is however unlikely to be caused by peripheral neuropathy given the non-length-dependent distribution and the absence of neuropathic pain features. Chronic pain in AUD deserves to be better evaluated and managed as it represents an opportunity to improve long-term clinical outcomes, potentially participating to relapse prevention.

Chronic alcohol induced mechanical allodynia by promoting neuroinflammation: A mouse model of alcohol-evoked neuropathic pain

BACKGROUND AND PURPOSE

Chronic pain is considered a key factor contributing to alcohol use disorder (AUD). The mechanisms responsible for chronic pain associated with chronic alcohol consumption are unknown. We evaluated the development of chronic pain in a mouse model of alcohol dependence and investigate the role of neuroinflammation.

EXPERIMENTAL APPROACH

The chronic-intermittent ethanol two-bottle choice CIE-2BC paradigm generates three groups: alcohol-dependent with escalating alcohol intake, nondependent (moderate drinking) and alcohol-naïve control male and female mice. We measured mechanical allodynia during withdrawal and after the last voluntary drinking. Immunoblotting was used to evaluate the protein levels of IBA-1, CSFR, IL-6, p38 and ERK2/1 in spinal cord tissue of dependent and non-dependent animals.

KEY RESULTS

We found significant escalation of drinking in the dependent group in male and female compared with the non-dependent group. The dependent group developed mechanical allodynia during 72 h of withdrawal, which was completely reversed after voluntary drinking. We observed an increased pain hypersensitivity compared with the naïve in 50% of non-dependent group. Increased IBA-1 and CSFR expression was observed in spinal cord tissue of both hypersensitivity-abstinence related and neuropathy-alcohol mice, and increased IL-6 expression and ERK1/2 activation in mice with hypersensitivity-related to abstinence, but not in mice with alcohol-evoked neuropathic pain.

CONCLUSIONS AND IMPLICATIONS

The CIE-2BC model induces two distinct pain conditions specific to the type of ethanol exposure: abstinence-related hypersensitivity in dependent mice and alcohol-evoked neuropathic pain in about a half of the non-dependent mice.

Neuroprotective effects of vitamin B1 on memory impairment and suppression of pro-inflammatory cytokines in traumatic brain injury

Traumatic Brain Injury (TBI) remains one of the prevailing disorders that affect millions of people around the globe. There is a cascade of secondary attributes attached to TBI including excitotoxicity, axonal degeneration, neuroinflammation, oxidative stress, and apoptosis. Neuroinflammation is caused due to the activation of microglia along with pro-inflammatory cytokines. The activation of microglia triggers TNF-α which sequentially results in the triggering and upregulation of NF-kB. The aim of the current research was to investigate vitamin B1's potential as neuroprotective agent against TBI-induced neuroinflammation arbitrated memory impairment together with pre- and post-synaptic dysfunction in an adult albino male mice model. TBI was induced using the weight-drop method which caused the microglial activation resulting in neuroinflammation along with synaptic dysfunction leading to the memory impairment of the adult mice. Vitamin B1 was administered for seven days via the intraperitoneal pathway. To analyze the memory impairment and efficacy of vitamin B1, Morris water maze and Y-maze tests were performed. The escape latency time and short-term memories of the experimental mice treated with vitamin B1 were significantly different from the reference mice. The western blot results showed that vitamin B1 has reduced neuroinflammation by downregulating proinflammatory cytokines (NFκ-B, TNF- α). Vitamin B1 also proved its worthiness as a convincing neuroprotective agent by reducing memory dysfunction and recovering the activities of pre- and post-synapse via upregulation of synaptophysin and Postsynaptic density protein 95 (PSD-95).

The Association of Alcohol Consumption with Glaucoma and Related Traits: Findings from the UK Biobank

PURPOSE

To examine the associations of alcohol consumption with glaucoma and related traits, to assess whether a genetic predisposition to glaucoma modified these associations, and to perform Mendelian randomization (MR) experiments to probe causal effects.

DESIGN

Cross-sectional observational and gene-environment interaction analyses in the UK Biobank. Two-sample MR experiments using summary statistics from large genetic consortia.

PARTICIPANTS

UK Biobank participants with data on intraocular pressure (IOP) (n = 109 097), OCT-derived macular inner retinal layer thickness measures (n = 46 236) and glaucoma status (n = 173 407).

METHODS

Participants were categorized according to self-reported drinking behaviors. Quantitative estimates of alcohol intake were derived from touchscreen questionnaires and food composition tables. We performed a 2-step analysis, first comparing categories of alcohol consumption (never, infrequent, regular, and former drinkers) before assessing for a dose-response effect in regular drinkers only. Multivariable linear, logistic, and restricted cubic spline regression, adjusted for key sociodemographic, medical, anthropometric, and lifestyle factors, were used to examine associations. We assessed whether any association was modified by a multitrait glaucoma polygenic risk score. The inverse-variance weighted method was used for the main MR analyses.

MAIN OUTCOME MEASURES

Intraocular pressure, macular retinal nerve fiber layer (mRNFL) thickness, macular ganglion cell-inner plexiform layer (mGCIPL) thickness, and prevalent glaucoma.

RESULTS

Compared with infrequent drinkers, regular drinkers had higher IOP (+0.17 mmHg; P < 0.001) and thinner mGCIPL (-0.17 μm; P = 0.049), whereas former drinkers had a higher prevalence of glaucoma (odds ratio, 1.53; P = 0.002). In regular drinkers, alcohol intake was adversely associated with all outcomes in a dose-dependent manner (all P < 0.001). Restricted cubic spline regression analyses suggested nonlinear associations, with apparent threshold effects at approximately 50 g (∼6 UK or 4 US alcoholic units)/week for mRNFL and mGCIPL thickness. Significantly stronger alcohol-IOP associations were observed in participants at higher genetic susceptibility to glaucoma (Pinteraction < 0.001). Mendelian randomization analyses provided evidence for a causal association with mGCIPL thickness.

CONCLUSIONS

Alcohol intake was consistently and adversely associated with glaucoma and related traits, and at levels below current United Kingdom (< 112 g/week) and United States (women, < 98 g/week; men, < 196 g/week) guidelines. Although we cannot infer causality definitively, these results will be of interest to people with or at risk of glaucoma and their advising physicians.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Alcohol-mediated susceptibility to lung fibrosis is associated with group 2 innate lymphoid cells in mice

Chronic alcohol ingestion promotes acute lung injury and impairs immune function. However, the mechanisms involved are incompletely understood. Here, we show that alcohol feeding enhances bleomycin-induced lung fibrosis and inflammation via the regulation of type 2 innate immune responses, especially by group 2 innate lymphoid cells (ILC2s). Neuroimmune interactions have emerged as critical modulators of lung inflammation. We found alcohol consumption induced the accumulation of ILC2 and reduced the production of the neuropeptide calcitonin gene-related peptide (CGRP), primarily released from sensory nerves and pulmonary neuroendocrine cells (PNECs). CGRP potently suppressed alcohol-driven type 2 cytokine signals in vivo. Vagal ganglia TRPV1+ afferents mediated immunosuppression occurs through the release of CGRP. Inactivation of the TRPV1 receptor enhanced bleomycin-induced fibrosis. In addition, mice lacking the CGRP receptor had the increased lung inflammation and fibrosis and type 2 cytokine production as well as exaggerated responses to alcohol feeding. Together, these data indicate that alcohol consumption regulates the interaction of CGRP and ILC2, which is a critical contributor of lung inflammation and fibrosis.

Irisin attenuates ethanol-induced behavioral deficits in mice through activation of Nrf2 and inhibition of NF-κB pathways

This study aims to investigate the effect of irisin on ethanol-induced behavioral deficits and explore the underlying mechanisms. A mouse model of ethanol addiction/withdrawal was constructed through chronic ethanol administration. Depressive-like behaviors were evaluated by the tail suspension test and forced swimming test, and anxiety-like behaviors were evaluated by the marble-burying test and elevated plus maze test. The expression of Nrf2 was measured by western blotting. Levels of inflammatory mediators (NF-κB, TNF-α, IL-1β and IL-6) and oxidative stress factors (ROS, MDA, GSH and SOD) were detected by ELISA. The ethanol-induced PC12/BV2 cell injury model was used to elucidate whether the effect of irisin on ethanol-induced neurological injury was related to anti-inflammatory and antioxidant mechanisms. Ethanol-induced ethanol preference and emotional deficits were improved by chronic irisin treatment; however, these improvements were partly reversed by cotreatment with the Nrf2 inhibitor ML385. Further results implied that the improvement effect of irisin on behavioral abnormalities may be related to its anti-inflammatory and antioxidant effects. In detail, irisin inhibited ethanol-induced abnormal expression of ROS and MDA and upregulated the expression of GSH and SOD. Meanwhile, irisin treatment inhibited ethanol-induced overexpression of NF-κB, TNF-α, IL-1β and IL-6 in the hippocampus and cerebral cortex. The regulation of oxidative stress factors by irisin was reversed after ML385 treatment. In the in vitro study, overexpression of oxidative stress factors in ethanol-treated PC12 cells was inhibited by irisin treatment; however, the prevention was reversed after the knockdown of Nrf2 siRNA. Moreover, ethanol-induced overexpression of inflammatory mediators in BV2 cells was also inhibited by irisin treatment. Irisin improved depressive and anxiety-like behaviors induced by ethanol addiction/withdrawal in mice, and this protection was greatly associated with the NF-κB-mediated anti-inflammatory signaling pathway and Nrf2-mediated antioxidative stress signaling pathway.

Comparison of the effects of ketoprofen and ketoprofen lysine salt on the Wistar rats' nervous system, kidneys and liver after ethyl alcohol intoxication

Side effects of Ketoprofen and ketoprofen lysine salt (KLS) may be inter alia from the central nervous system, kidneys and liver. After binge drinking people often use ketoprofen, which increases the risk for the occurrence of side effects. The aim of the study was to compere effects of ketoprofen and KLS on the nervous system, kidneys and liver after ethyl alcohol intoxication. There were 6 groups of 6 male rats which received: ethanol; 0.9%NaCl; 0.9%NaCl and ketoprofen; ethanol and ketoprofen; 0.9%NaCl and KLS; ethanol and KLS. On day 2, the motor coordination test on a rotary rod and memory and motor activity test in the Y-maze were performed. Hot plate test was performed on day 6. After euthanasia brains, livers and kidneys were taken to histopathological tests. Motor coordination was significant worse in group 5 vs 1,3, p 0.05. Spontaneous motor activity of group 6 was significant better than that of groups 1,5. Pain tolerance of group 6 was significant worse than that of groups 1,4,5. Liver and kidney mass were significantly lower in group 6 vs group 3,5 and vs group 1,3, respectively. The histopathologic examination of the brains and kidneys revealed normal picture in all groups, without signs of inflammation. In the histopathologic examination of the livers in one animal in group 3 some of the specimens showed perivascular inflammation. After alcohol ketoprofen is a better painkiller than KLS. Spontaneous motor activity is better after KLS after alcohol. Both drugs have a similar effect on the kidneys and liver.

Sex-specific differences in alcohol-induced pain sensitization

Pain sensitization is a phenomenon that occurs to protect tissues from damage and recent studies have shown how a variety of non-noxious stimuli included in our everyday lives can lead to pain sensitization. Consumption of large amounts of alcohol over a long period of time invokes alcohol use disorder (AUD), a complex pathological state that has many manifestations, including alcohol peripheral neuropathy (neuropathic pain). We asked if 'non-pathological' alcohol consumption can cause pain sensitization in the absence of other pathology? Studies have pointed to glia and other immune cells and their role in pain sensitization that results in cell and sex-specific responses. Using a low-dose and short-term ethanol exposure model, we investigated whether this exposure would sensitize mice to a subthreshold dose of an inflammatory mediator that normally does not induce pain. We observed female mice exhibited specific mechanical and higher thermal sensitivity than males. We also observed an increase in CD68⁺ macrophages in the ipsilateral dorsal root ganglia (DRG) and Iba1⁺ microglia in the ipsilateral spinal dorsal horn of animals that were exposed to ethanol and injected with subthreshold inflammatory prostaglandin E2. Our findings suggest that short-term ethanol exposure stimulates peripheral and central, immune and glial activation, respectively to induce pain sensitization. This work begins to reveal a possible mechanism behind the development of alcoholic peripheral neuropathy.

Development and external validation of multivariable risk models to predict incident and resolved neuropathic pain: a DOLORisk Dundee study

Neuropathic pain is difficult to treat, and an understanding of the risk factors for its onset and resolution is warranted. This study aimed to develop and externally validate two clinical risk models to predict onset and resolution of chronic neuropathic pain. Participants of Generation Scotland: Scottish Family Health Study (GS; general Scottish population; n = 20,221) and Genetic of Diabetes Audit and Research in Tayside Scotland (GoDARTS; n = 5236) were sent a questionnaire on neuropathic pain and followed- -up 18 months later. Chronic neuropathic pain was defined using DN4 scores (≥ 3/7) and pain for 3 months or more. The models were developed in GS using logistic regression with backward elimination based on the Akaike information criterion. External validation was conducted in GoDARTS and assessed model discrimination (ROC and Precision-Recall curves), calibration and clinical utility (decision curve analysis [DCA]). Analysis revealed incidences of neuropathic pain onset (6.0% in GS [236/3903] and 10.7% in GoDARTS [61/571]) and resolution (42.6% in GS [230/540] and 23.7% in GoDARTS [56/236]). Psychosocial and lifestyle factors were included in both onset and resolved prediction models. In GoDARTS, these models showed adequate discrimination (ROC = 0.636 and 0.699), but there was evidence of miscalibration (Intercept = - 0.511 and - 0.424; slope = 0.623 and 0.999). The DCA indicated that the models would provide clinical benefit over a range of possible risk thresholds. To our knowledge, these are the first externally validated risk models for neuropathic pain. The findings are of interest to patients and clinicians in the community, who may take preventative or remedial measures.

Construction and validation of a nomogram for predicting the risk of secondary peripheral neuropathy in patients with advanced lung cancer

OBJECTIVE

To construct and validate a nomogram for predicting the risk of secondary peripheral neuropathy in patients with advanced lung cancer.

METHODS

The sociodemographic and clinical data of 335 patients with advanced lung cancer admitted to Department of Respiratory, the First Affiliated Hospital of Zhejiang University School of Medicine from May 2020 to May 2021 were retrospectively collected. Pearson correlation analysis, univariate and multivariate logistic regression analyses were used to identify the risk factors of secondary peripheral neuropathy in patients with advanced lung cancer. A nomogram was constructed according to the contribution of each risk factor to secondary peripheral neuropathy, and the receiver operating characteristic (ROC) curve, Calibration curve and clinical decision curve were used to evaluate differentiation, calibration, and the clinical utility of the model. The nomogram was further validated with data from 64 patients with advanced lung cancer admitted between June 2021 and August 2021.

RESULTS

The incidences of secondary peripheral neuropathy in two series of patients were 34.93% (117/335) and 40.63% (26/64), respectively. The results showed that drinking history ( OR=3.650, 95% CI: 1.523-8.746), comorbid diabetes ( OR=3.753, 95% CI: 1.396-10.086), chemotherapy ( OR=2.887, 95% CI: 1.046-7.970), targeted therapy ( OR=8.671, 95% CI: 4.107-18.306), immunotherapy ( OR=2.603, 95% CI: 1.337-5.065) and abnormal liver and kidney function ( OR=12.409, 95% CI: 4.739-32.489) were independent risk factors for secondary peripheral neuropathy (all P<0.05). A nomogram was constructed based on the above risk factors. The area under the ROC curve (AUC) of the nomogram for predicting the secondary peripheral neuropathy was 0.913 (95% CI: 0.882-0.944); and sensitivity, specificity, positive and negative predictive values were 85.47%, 81.65%, 71.43% and 91.28%, respectively. The Calibration curve and clinical decision curve showed good calibration and clinical utility. External validation results showed that the AUC was 0.764 (95% CI: 0.638-0.869); and sensitivity, specificity, positive and negative predictive values were 79.28%, 85.79%, 73.25% and 85.82%, respectively.

CONCLUSIONS

Advanced lung cancer patients have a high risk of secondary peripheral neuropathy after anticancer therapy. Drinking history, comorbid diabetes, chemotherapy, targeted therapy, immunotherapy, abnormal liver and kidney function are independent risk factors. The nomogram prediction model constructed in the study is effective and may be used for the risk assessment of secondary peripheral neuropathy in patients with advanced lung cancer.

Alcoholic neuropathy associated with chronic alcohol intake

Alcoholic neuropathy (AN), a debilitating condition that mainly affects chronic alcohol drinkers, is thought to cause lesions in the peripheral nervous system leading to sensory, autonomic, and motor dysfunctions. Despite many studies, the pathogenesis of these lesions is still not completely understood. We investigated few aspects on the development of alcohol-induced peripheral neuropathy, by assessing sensory, motor and autonomic functions, as well as stereological analysis of axonal fibers and myelin sheath of the sciatic nerve. Twelve male Wistar rats were divided into Control group and Alcohol group that was submitted to Two Bottle-Choice Paradigm of intermittent and voluntary alcohol solution intake (20%; v/v) during eight weeks. At the end of treatment, three different sensorium-motor tests were applied - Tactile Sensitivity, Thermal Sensitivity, and Functional Observational Battery (FOB). Quantitative morphometric analysis of sciatic nerve structures was performed by stereological method. Alcohol concentration in the blood was measured to analyze possible correlation between availability of alcohol in the blood and the magnitude of the peripheral nerve lesion. Our data showed a peripheral effect of chronic alcohol intake associated with hyperalgesia and a process of demyelination with a strong correlation with alcohol consumption. This process was associated with increased tactile sensitivity, with behavioral reflexes such as locomotor hyperactivity, changes in gait and balance, and autonomic reflexes such as piloerection.

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Alcoholic neuropathy and its consequences.

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Neuropathy and sensitive and motor alterations.

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Alcoholic neuropathy and thinner myelin sheath thickness.

A review of the diet, nutrients, and supplementation potential for the outcome augmentation in surgical treatment of peripheral nerve injuries

OBJECTIVE

Although the studies have shown the beneficial effects of diet, nutrition, and supplementation as an independent treatment modality, their roles are underestimated in the treatment of peripheral nerve injuries. This is in great part due to the development of efficient nerve repair techniques, combined with physical treatment and stimulation. To achieve the best possible functional recovery diet, nutrition, and supplementation should be implemented within a multidisciplinary approach. The aim of the study is to provide insight into the potentially beneficial effects of diet, nutrients, and supplementation, in the limitation of nerve damage and augmentation of the functional recovery after surgery in a review of human and animal studies.

METHODS

The data relating to the diet, nutrients, and supplementation effects on peripheral nerve injuries and their treatment was extracted from the previously published literature.

RESULTS

General balanced diet as well as obesity influence the initial nerve features prior to the injury. In the period following the injury, neuroprotective agents demonstrated beneficial effects prior to surgery, and immediately after the injury, while those potentiating nerve regeneration may be used after the surgical repair to complement the physical treatment and stimulation for improved functional recovery.

CONCLUSIONS

Standardized diet, nutrition, and supplementation recommendations and protocols may be of great importance for better nerve regeneration and functional recovery as a part of the multidisciplinary approach to achieve the best possible results in surgically treated patients with peripheral nerve injuries in the future.

Enteric VIP-producing neurons maintain gut microbiota homeostasis through regulating epithelium fucosylation

Interactions between the enteric nervous system (ENS) and intestinal epithelium are thought to play a vital role in intestinal homeostasis. How the ENS monitors the frontier with commensal and pathogenic microbes while maintaining epithelial function remains unclear. Here, by combining subdiaphragmatic vagotomy with transcriptomics, chemogenetic strategy, and coculture of enteric neuron-intestinal organoid, we show that enteric neurons expressing VIP shape the α1,2-fucosylation of intestinal epithelial cells (IECs). Mechanistically, neuropeptide VIP activates fut2 expression via the Erk1/2-c-Fos pathway through the VIPR1 receptor on IECs. We further demonstrate that perturbation of enteric neurons leads to gut dysbiosis through α1,2-fucosylation in the steady state and results in increased susceptibility to alcohol-associated liver disease (ALD). This was attributed to an imbalance between beneficial Bifidobacterium and opportunistic pathogenic Enterococcus faecalis in ALD. In addition, Bifidobacterium α1,2-fucosidase may promote Bifidobacterium adhesion to the mucosal surface, which restricts Enterococcus faecalis overgrowth and prevents ALD progression.

Remnant Cholesterol and Dyslipidemia Are Risk Factors for Guillain–Barré Syndrome and Severe Guillain–Barré Syndrome by Promoting Monocyte Activation

Background

Guillain–Barré syndrome (GBS) is the most common severe acute paralytic neuropathy, with a mortality rate of 5% and permanent sequelae rate of 10%. Currently, the cause of GBS remains unclear. Therefore, we sought to determine potential predictors for GBS and its severity.

Methods

A case–control study was performed at Tiantan Hospital in Beijing from January 2017 to December 2021. Laboratory and clinical characteristics were assessed in recruited GBS patients and healthy control individuals (matched by sex and age). The potential risk factors for GBS and severe GBS were assessed using a logistic regression analysis. The mRNA levels of toll-like receptor 4 (TLR4), toll-like receptor 2 (TLR2) and nuclear factor κB (NF-κB) in GBS patients and control PBMCs were detected by fluorescence quantitative PCR. THP-1 cells were costimulated with LPS and free cholesterol to demonstrate the effect of free cholesterol on monocyte activation.

Results

A total of 147 GBS patients and 153 healthy individuals were included in the study. Logistic regression analyses showed that preceding infection, alcohol consumption, remnant cholesterol, homocysteine and the dyslipidemia index were correlated with a higher risk of GBS. In contrast, increased HDL cholesterol was correlated with a lower risk of GBS. Moreover, remnant cholesterol and the dyslipidemia index were significantly correlated with severe GBS. The mRNA levels of TLR4, TLR2 and NF-κB in the PBMCs of GBS patients were significantly higher than those of healthy individuals. LPS activated THP-1 cells, and free cholesterol treatment increased the expression of TLR4, TLR2, NF-κB and IL-1β mRNA in LPS-activated THP-1 cells.

Conclusion

Dyslipidemia was correlated with the risk of GBS and severe GBS. Remnant cholesterol may promote the activation of monocytes in GBS patients. It may be valuable to control lipid levels in the prevention of GBS and severe GBS.

Effects of ethanol and deferoxamine on rat primary glial cell cultures, in regard with ischemia induced by traumatic spinal cord injury

Although they have been regarded, in the past, as passive support cells, many experimental data have shown that glial cells play a critical role in the development and functioning of the nervous system. Despite the advances that have been made in understanding astrocytes' role in the nervous system's development and function, our knowledge of their interactions with other cells is still limited, albeit neurons are dependent on the trophic support provided by astrocytes release. Materials and Methods. The use of the McCarthy and de Vellis methods for isolating glial cells has been regarded as an essential tool for studying their function. This study aims to evaluate the effects of ethanol and deferoxamine on primary rat glial cell cultures and try to explain, as far as possible, the relevance of such effects for patients with chronic alcoholism and traumatic spinal cord injuries. Discussion. Because glial cells are very important in the functioning of the central nervous system and experiments cannot be performed on human primary nerve cell cultures, we performed an experiment on glial cells harvested from the newborn rat, analyzing the dynamics of IL-6 and TNF alpha on models of suffering in spinal cord injury (hypoxia and thermally stress). Conclusion. Inhibition of TNF alpha synthesis was more important at 7 days posttraumatic in cells with prolonged ethanolic exposure, even if protein levels of IL-6 were elevated (under similar experimental conditions). Thus, we can say that long-term exposure to ethanol of nerve cells can ensure a favorable evolution of medical recovery (by increasing TNF alpha), even if the inflammatory process remains active (shown by elevated IL-6 values). Keywords: ethyl alcohol, deferoxamine, primary glial cells cultures, traumatic Spinal Cord Injury

Toxic and Nutritional Optic Neuropathies—An Updated Mini-Review

Optic neuropathies constitute a group of conditions with various etiologies and might be caused by different factors; we can distinguish the genetic and acquired causes of optic neuropathies. Even though the symptoms are not highly specific, this condition is primarily characterized by unilateral or bilateral vision loss with worsening color detection. The loss may be acute or gradual depending on the causation. In this article, we included a specification of toxic optic neuropathy (TON) mainly triggered by alcohol abuse and also the usage of other substances, including drugs or methanol, as well as intoxication by metals, organic solvents, or carbon dioxide. Nutritional deficiencies, vitamin absorption disorder, and anemia, which usually appear during excessive alcohol intake, and their effect on the etiology of the optic neuropathy have been likewise discussed.

Chronic Alcohol Abuse Alters Hepatic Trace Element Concentrations-Metallomic Study of Hepatic Elemental Composition by Means of ICP-OES

Trace element accumulation varies in different human tissues. Distribution of several elements was found to be disrupted in the case of excessive alcohol consumption, causing negative effects and exacerbation of pathological processes in the liver. In this study, we analyzed the levels and interactions between seven trace elements including calcium (Ca), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), potassium (K), and magnesium (Mg), manganese (Mn), sodium (Na), zinc (Zn), and selenium (Se) in individuals with alcohol-use disorder (AUD) and patients without AUD (control group). The liver samples were collected during autopsy from 39 individuals with AUD and 45 control subjects. Elemental composition inductively coupled plasma optical emission spectrometry (ICP-OES) after wet mineralization by nitric acid was applied for the evaluation of the samples. Positive correlations dominated in the AUD group, mainly in relation to Mg, which strongly positively correlated with Ca, Mn, Fe; K correlated with Mn and Zn, and Cu positively correlated with K and Zn. The strongest positive correlation in the AUD group was observed for the Mg-Mn pair (r = 0.87). Significant statistical differences (p < 0.05) between the groups concerned the average concentration of Co, Cu, Mn, and Mg, which were lower in the AUD group, and Fe, the level of which was significantly higher in the AUD group compared to the control group. Evaluation of the chronic alcohol consumption effect on the accumulation of trace elements in the liver allows a better understanding of the pathological processes taking place in this organ.

Alcohol, intraocular pressure and open-angle glaucoma: A systematic review and meta-analysis

Topic

This systematic review and meta-analysis summarizes the existing evidence for the association of alcohol use with intraocular pressure (IOP) and open-angle glaucoma (OAG).

Clinical Relevance

Understanding and quantifying these associations may aid clinical guidelines or treatment strategies and shed light on disease pathogenesis. The role of alcohol, a modifiable factor, in determining IOP and OAG risk also may be of interest from an individual or public health perspective.

Methods

The study protocol was preregistered in the Open Science Framework Registries (https://osf.io/z7yeg). Eligible articles (as of May 14, 2021) from 3 databases (PubMed, Embase, Scopus) were independently screened and quality assessed by 2 reviewers. All case-control, cross-sectional, and cohort studies reporting a quantitative effect estimate and 95% confidence interval (CI) for the association between alcohol use and either IOP or OAG were included. The evidence for the associations with both IOP and OAG was qualitatively summarized. Effect estimates for the association with OAG were pooled using random effects meta-analysis. Studies not meeting formal inclusion criteria for systematic review, but with pertinent results, were also appraised and discussed. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

Results

Thirty-four studies were included in the systematic review. Evidence from 10 studies reporting an association with IOP suggests that habitual alcohol use is associated with higher IOP and prevalence of ocular hypertension (IOP > 21 mmHg), although absolute effect sizes were small. Eleven of 26 studies, comprising 173 058 participants, that tested for an association with OAG met inclusion criteria for meta-analysis. Pooled effect estimates indicated a positive association between any use of alcohol and OAG (1.18; 95% confidence interval [CI], 1.02–1.36; P = 0.03; I² = 40.5%), with similar estimates for both prevalent and incident OAG. The overall GRADE certainty of evidence was very low.

Conclusions

Although this meta-analysis suggests a harmful association between alcohol use and OAG, our results should be interpreted cautiously given the weakness and heterogeneity of the underlying evidence base, the small absolute effect size, and the borderline statistical significance. Nonetheless, these findings may be clinically relevant, and future research should focus on improving the quality of evidence.

Patients with alcohol use disorder increase pain and analgesics use: A nationwide population-based cohort study

BACKGROUND

Alcohol has dual effects on many systems, including the pain system. We will test whether and how chronic alcohol consumption enhances pain sensation to develop pain disorder.

METHODS

We conducted a retrospective matched cohort study using data from the National Health Insurance Research Database (NHIRD) in Taiwan, in patients with and without alcohol use disorder (AUD). This study enrolled 19,174 individuals with AUD as study cohort and 19,174 propensity score-matched individuals without AUD as comparison cohort. The outcome was the incidence of pain disorders and the need for analgesics. The hazard ratios of pain disorders and the need for analgesics were evaluated using Cox proportional hazard regression analysis after adjusting for age, sex, index year, comorbidities, urbanization, areas of residence, and insurance premium.

RESULTS

The 14 years of follow-up showed that AUD patients had a higher adjusted hazard ratio (aHR) for developing pain disorders than in non-AUD controls [aHR= 1.290, 95% confidence interval (CI): 1.045-1.591]. Besides, AUD patients had a higher risk of analgesic use (aHR = 1.081, 95% CI: 1.064-1.312), including opioids and non-opioid analgesics. Most importantly, AUD patients required more days of analgesic use, increased dose of analgesics, and higher costs of analgesics. Moreover, AUD patients had more anemia (aHR=2.772, 95% CI: 2.581-2.872), which could be a mediating factor.

CONCLUSIONS

AUD patients had higher risks of developing pain disorders and subsequently increased analgesic demand. These results suggest that AUD worsened pain, and pain syndrome is correlated with the duration of chronic alcohol exposure.

Alcohol Use Disorder in Older Adults

As the number of older adults worldwide continues to grow, we observe a proportional growth of substance use. Despite the myriad of complications alcohol use disorder (AUD) has on the body with regards to organ systems and mental health, the topic has been underresearched in the older adult population. Thus, it is important to create awareness about the growing problem of AUD among older adults. In this way, we can mitigate the long-term complications and side effects observed with alcohol abuse in this vulnerable population.

Alcohol Consumption as a Causator and/or an Accelerator of Neuropathy in People With Diabetes Is Regularly Overlooked

Patients with diabetes and distal symmetrical polyneuropathy (DSP) are routinely evaluated for etiologies other than diabetes, including vitamin B12 deficiency, paraproteinemia, hypothyroidism and drug or autoimmune-induced neuropathy. However, the most common cause of DSP, next to that of diabetes, is alcohol intake, which is almost never evaluated. In addition to assessment of alcohol intake based on patient history, which often leads to an underestimation of alchohol intake, markers of a high alcohol intake (elevated liver enzymes, uric acid, triglycerides, low magnesium or low folic acid levels) should be obtained. However, the test that is most likely to detect surreptitious alcohol intake is urinary ethyl glucuronide (EtG), which will detect the intake of alcohol within the previous 90 h. Detection of alcohol use is important since if alcohol consumption is not discontinued, DSP, whatever the etiology, will not improve. In addition, the use of drugs to improve symptoms of DSP (tricyclics, anti-epileptics, serotonin, norepinephrine reuptake inhibitors and analgesics) may in combination with alcohol excessively suppress respiration and cognitive function such that these drugs should not be prescribed or utilized if use of alcohol continues. In the future, all patients with DSP, and especially those with symptomatic DSP, should be biochemically screened for excessive alcohol intake and appropriate action taken.

Prevalence of peripheral neuropathy defined by monofilament insensitivity in middle-aged and older adults in two US cohorts

Peripheral neuropathy is associated with substantial morbidity, but risk factors other than diabetes are largely uncharacterized. The aim of this study was to describe the prevalence and risk factors for peripheral neuropathy in adults with and without diabetes from two different population-based studies in the US. We performed a cross-sectional analysis of 5200 black and white participants from NHANES (1999-2004, age 40-85 years) and 3362 black and white participants from the ARIC Study (2016-2017, age 70-89 years) who underwent monofilament testing for peripheral neuropathy using a shared protocol. We used logistic regression to quantify age, sex, and race-adjusted risk factor associations for peripheral neuropathy among middle-aged (40-69 years) and older (≥ 70 years) adults. The age, sex, and race-adjusted prevalence of peripheral neuropathy (decreased sensation on monofilament testing) was 10.4% for middle-aged adults in NHANES, 26.8% for older adults in NHANES, and 39.2% for older adults in ARIC. Diabetes was an important risk factor, but more strongly associated with peripheral neuropathy in middle-aged (OR ~ 5 for long-standing diabetes) compared to older adults (ORs ~ 1.5-2). Male sex (ORs ~ 2), black race (ORs ~ 1.3-1.5), and greater height (ORs ~ 1.5-3) were robust risk factors for peripheral neuropathy. Other risk factors included body mass index, education, and peripheral artery disease. The burden of peripheral neuropathy defined by abnormal monofilament testing among older adults is substantial, even among adults without diabetes. Studies are needed to understand the etiology and prognosis of peripheral neuropathy in the absence of diabetes.

Characterization and quantification of alcohol-related polyneuropathy by magnetic resonance neurography

BACKGROUND

We characterized and quantified peripheral nerve damage in alcohol-dependent patients (ADP) by magnetic resonance neurography (MRN) in correlation with clinical and electrophysiologic findings.

METHODS

Thirty-one adult patients with a history of excessive alcohol consumption and age-/sex-matched healthy controls were prospectively examined. After detailed neurologic and electrophysiologic testing, the patient group was subdivided into ADP with alcohol-related polyneuropathy (ALN) and without ALN (Non-ALN). 3T MRN with anatomical coverage from the proximal thigh down to the tibiotalar joint was performed using dual-echo 2-dimensional relaxometry sequences with spectral fat saturation. Detailed quantification of nerve injury by morphometric (cross-sectional area [CSA]) and microstructural MRN markers (proton spin density [ρ], apparent T2-relaxation-time [T2_app ]) was conducted in all study participants.

RESULTS

MRN detected nerve damage in ADP with and without ALN. A proximal-to-distal gradient was identified for nerve T2-weighted (T2w)-signal and T2_app in ADP, indicating a proximal predominance of nerve lesions. While all MRN markers differentiated significantly between ADP and controls, microstructural markers were able to additionally differentiate between subgroups: tibial nerve ρ at thigh level was increased in ALN (p < 0.0001) and in Non-ALN (p = 0.0052) versus controls, and T2_app was higher in ALN versus controls (p < 0.0001) and also in ALN versus Non-ALN (p = 0.0214). T2w-signal and CSA were only higher in ALN versus controls.

CONCLUSIONS

MRN detects and quantifies peripheral nerve damage in ADP in vivo even in the absence of clinically overt ALN. Microstructural markers (T2_app , ρ) are most suitable for differentiating between ADP with and without manifest ALN, and may help to elucidate the underlying pathomechanism in ALN.

Herbal Prescription SH003 Alleviates Docetaxel-Induced Neuropathic Pain in C57BL/6 Mice

Docetaxel-based therapy has been applied to kill cancers including lung and breast cancers but frequently causes peripheral neuropathy such as mechanical allodynia. Lack of effective drugs for chemotherapy-induced peripheral neuropathy (CIPN) treatment leads us to find novel drugs. Here, we investigated whether and how novel anticancer herbal prescription SH003 alleviates mechanical allodynia in mouse model of docetaxel-induced neuropathic pain. Docetaxel-induced mechanical allodynia was evaluated using von Frey filaments. Nerve damage and degeneration in paw skin of mice were investigated by immunofluorescence staining. Neuroinflammation markers in bloodstream, lumbar (L4-L6) spinal cord, and sciatic nerves were examined by ELISA or western blot analysis. Docetaxel (15.277 mg/kg) was intravenously injected into the tail vein of C57BL/6 mice, and mechanical allodynia was followed up. SH003 (557.569 mg/kg) was orally administered at least 60 min before the mechanical allodynia test, and von Frey test was performed twice. Docetaxel injection induced mechanical allodynia, and SH003 administration restored withdrawal threshold. Meanwhile, degeneration of intraepidermal nerve fibers (IENF) was observed in docetaxel-treated mice, but SH003 treatment suppressed it. Moreover, docetaxel injection increased levels of TNF-α and IL-6 in plasma and expressions of phospho-NF-κB and phospho-STAT3 in both of lumbar spinal cord and sciatic nerves, while SH003 treatment inhibited those changes. Taken together, it is worth noting that TNF-α and IL-6 in plasma and phospho-NF-κB and phospho-STAT3 in spinal cord and sciatic nerves are putative biomarkers of docetaxel-induced peripheral neuropathy (DIPN) in mouse models. In addition, we suggest that SH003 would be beneficial for alleviation of docetaxel-induced neuropathic pain.

Hyperalgesia after a Drinking Episode in Young Adult Binge Drinkers: A Cross-Sectional Study

AIMS

Rodent studies propose potential mechanisms linking excessive drinking and pain hypersensitivity (hyperalgesia), such that stress hormones (i.e. epinephrine and cortisol) mediate induction and maintenance of alcohol withdrawal-induced hyperalgesia. The first aim of this study was to examine whether hyperalgesia would occur within 48 h after a drinking episode in healthy young adult binge drinkers. The second was to examine whether stress hormones and negative effect would be associated with binge drinking or alcohol withdrawal-associated hyperalgesia.

METHODS

A cross-sectional experiment was conducted in five groups with naturally occurring drinking (mean age = 19.6, range 18-29 years): abstainers (n = 43, 54% female), moderate drinkers with (n = 50, 50% female) or without recent drinking (i.e. within 48 h, n = 23, 26% female) and binge drinkers with (n = 36, 58% female) or without recent drinking (n = 25, 44% female). All types of drinkers endorsed drinking about 2-3 times a month and 2-3 years of drinking history.

RESULTS

Muscle pressure pain thresholds were significantly lower in the binge group with recent drinking compared to other groups, but cutaneous mechanical and heat pain thresholds were not significantly different across the five groups. Basal epinephrine levels were significantly higher in binge groups regardless of recent drinking, but cortisol and negative effect were not significantly different across the five groups.

CONCLUSIONS

This is the first study to show that alcohol withdrawal-associated muscle hyperalgesia may occur in healthy episodic binge drinkers with only 2-3 years of drinking history, and epinephrine may play a role in binge drinking-associated hyperalgesia.

Cognitive-Affective Transdiagnostic Factors Associated With Vulnerability to Alcohol and Prescription Opioid Use in the Context of Pain

The use of alcohol and prescription opioids is common among people in pain and poses significant public health burdens. This review identifies factors associated with motivation to use alcohol and prescription opioids in the context of pain. Pain-relevant, cognitive-affective, transdiagnostic vulnerability factors-expectancies/motives, pain catastrophizing, pain-related anxiety, distress intolerance, anxiety sensitivity, and perceived interrelations-were selected from theoretical conceptualizations of pain and substance use. Searches conducted in PubMed, PsycINFO, and Embase returned 25 studies that examined associations between identified variables of interest and the use of alcohol and prescription opioids in the context of pain. Consistent with a larger literature on pain and substance use, the studies included in this review demonstrated that people with chronic pain are motivated to use alcohol and opioids in response to negative affect and hold expectancies/motives for coping with pain. Vulnerabilities that engender difficulty managing aversive internal states (distress intolerance and anxiety sensitivity) and maladaptive responses to pain (pain-related anxiety and pain catastrophizing) also were implicated in motivation for alcohol and opioid use. Although one study found that pain-related anxiety was associated with co-use of alcohol and opioids, no studies examined simultaneous use. Future research directions that can explicate causal associations, identify patterns of alcohol and opioid co-use, clarify the role of pain in cessation processes, and inform treatment development are discussed.

Chemotherapy-induced peripheral neuropathy after modern treatment of Hodgkin's lymphoma; symptom burden and quality of life

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting side effect of Hodgkin's lymphoma (HL) treatment. We aimed to describe the prevalence of CIPN associated symptoms in long-term HL survivors compared to controls, and determine associated factors, including impact on health-related quality of life (HRQoL).

MATERIAL AND METHODS

A questionnaire, including EORTC QLQ-CIPN-20 for CIPN related symptoms and SF-36 for HRQoL, was completed by 303 HL survivors at a median of 16 years after diagnosis. CIPN results were compared to a normative population (n = 606). CIPN associated factors were identified by linear regression analysis.

RESULTS

Total CIPN score and subscores were significantly higher in HL survivors compared to controls. In multivariate analysis of HL survivors, a number of comorbidities (p < 0.001) and female gender (p = 0.05) were significantly associated with more CIPN. No association with disease or treatment factors was found. In a multivariate analysis including survivors and controls, the number of comorbidities (p < 0.001) and caseness (p < 0.001) were significantly associated with more CIPN. In HL survivors higher CIPN score was associated with reduced HRQoL (p < 0.001).

CONCLUSION

HL survivors more than a decade after treatment report higher neuropathy-related symptom burden than controls, with a negative impact on HRQoL. Symptoms may be related to factors other than neurotoxic chemotherapy.

Burning sensation in the feet and glycosylated haemoglobin levels in Swedish- and non-Swedish-born primary healthcare patients

BACKGROUND

A painful burning sensation in the feet is a common problem. The most common cause is small fibre neuropathy, a type of peripheral neuropathy that is often a consequence of diabetes and prediabetes.

AIM

To examine the association between a self-reported burning sensation in the feet and HbA1c levels in primary healthcare patients.

METHODS

This study used data from patients in the 4D diabetes project in Swedish primary healthcare. The study population included 824 patients. Logistic regression was performed to study the association between the outcome and explanatory variables.

RESULTS

A total of 24% of patients reported a burning sensation in the feet. This sensation was not associated with HbA1c levels. However, the probability of reporting a burning sensation was two times higher in non-Swedish-born than Swedish-born patients (OR, 2.31; 95% CI, 1.55-3.44) and higher in smokers than those who had never smoked, regardless of region of birth (OR, 1.69; 95% CI, 1.07-2.65).

CONCLUSIONS

Our results do not support the hypothesis that a self-reported burning sensation in the feet is associated with HbA1c levels. Rather, they indicate a strong relationship between a burning sensation and region of birth, as well as between a burning sensation and smoking.

Beneficial effects of octreotide in alcohol-induced neuropathic pain. Role of H 2S, BDNF, TNF-α and Nrf2

Purpose

To explore the role and molecular mechanisms of neuroprotective effects of octreotide in alcohol-induced neuropathic pain.

Methods

Male Wistar rats were employed and were administered a chronic ethanol diet containing 5% v/v alcohol for 28 days. The development of neuropathic pain was assessed using von Frey hair (mechanical allodynia), pinprick (mechanical hyperalgesia) and cold acetone drop tests (cold allodynia). The antinociceptive effects of octreotide (20 and 40 µg·kg^–1) were assessed by its administration for 28 days in ethanol-treated rats. ANA-12 (0.25 and 0.50 mg·kg^–1), brain-derived neurotrophic factor (BDNF) receptor blocker, was coadministered with octreotide. The sciatic nerve was isolated to assess the biochemical changes including hydrogen sulfide (H₂S), cystathionine β synthase (CBS), cystathionine γ lyase (CSE), tumor necrosis factor-α (TNF-α), BDNF and nuclear factor erythroid 2-related factor 2 (Nrf2).

Results

Octreotide significantly attenuated chronic ethanol-induced neuropathic pain and it also restored the levels of H₂S, CBS, CSE, BDNF, Nrf2 and decreased TNF-α levels. ANA-12 abolished the effects of octreotide on pain, TNF-α, BDNF, Nrf2 without any significant effects on H₂S, CBS, CSE.

Conclusions

Octreotide may attenuate the behavioral manifestations of alcoholic neuropathic pain, which may be due to an increase in H₂S, CBS, CSE, BDNF, Nrf2 and a decrease in neuroinflammation.

A measure of expectancies for alcohol analgesia: Preliminary factor analysis, reliability, and validity

Rates of alcohol consumption are substantially higher among persons with pain, and recent research has focused on elucidating bidirectional pain-alcohol effects. Expectancies for alcohol analgesia could influence the degree to which alcohol confers acute pain-relieving effects, and may amplify the propensity to respond to pain with drinking behavior. However, no validated measures of expectancies for alcohol analgesia are available. Therefore, we developed a five-item measure of Expectancies for Alcohol Analgesia (EAA), which assesses the perceived likelihood that alcohol will reduce pain. The goal of this project was to examine psychometric properties of the EAA among a sample of 273 current alcohol users with chronic pain (M_age = 32.9; 34% female) who completed an online survey of pain and substance use. Confirmatory factor analysis (CFA) results indicated that the hypothesized single-factor structure of the EAA provided good model fit (Bollen-Stine bootstrap p = .13). The EAA also showed excellent internal consistency (α = 0.97), and scores were positively associated with quantity/frequency of alcohol use, alcohol outcome expectancies, coping-related drinking motives, and pain severity (ps < 0.01). These findings provide initial support regarding the single-factor structure, reliability, and validity of the EAA. Examination of predictive utility and further validation are important next steps.

A Rare Complication of Rhabdomyolysis: Peripheral Neuropathy

Rhabdomyolysis is a complex medical condition characterized by muscle necrosis and the release of intracellular components into the circulation. Although its most common cause is a direct traumatic injury, it can result from non-traumatic factors as well, including infection, toxins, and drugs. Serum creatine phosphokinase (CPK) levels are usually elevated in this condition and they correlate with the severity of the muscle damage (the higher the CPK peak, the greater the magnitude of muscle damage), although lower levels of CPK do not necessarily rule it out. The common complications associated with rhabdomyolysis include acute kidney injury, compartment syndrome, and, in rare cases, peripheral neuropathy. In this report, we present a case of a young patient, with a history of alcohol abuse, who presented with bilateral numbness of the feet post-immobilization and was subsequently found to have severe rhabdomyolysis.