Alcohol-related peripheral neuropathy: a systematic review and meta-analysis

Adolescent alcohol exposure promotes mechanical allodynia and alters synaptic function at inputs from the basolateral amygdala to the prelimbic cortex

Binge drinking is common among adolescents despite mounting evidence linking it to various adverse health outcomes that include heightened pain perception. The prelimbic (PrL) cortex is vulnerable to insult from adolescent alcohol exposure and receives input from the basolateral amygdala (BLA) while sending projections to the ventrolateral periaqueductal gray (vlPAG) - two brain regions implicated in nociception. In this study, adolescent intermittent ethanol (AIE) exposure was carried out in male and female rats using a vapor inhalation procedure. Assessments of mechanical and thermal sensitivity revealed that AIE exposure induced protracted mechanical allodynia. To investigate synaptic function at BLA inputs onto defined populations of PrL neurons, retrobeads and viral labelling were combined with optogenetics and slice electrophysiology. Recordings from retrobead labelled cells in the PrL revealed AIE reduced BLA driven feedforward inhibition of neurons projecting from the PrL to the vlPAG, resulting in augmented excitation/inhibition (E/I) balance and increased intrinsic excitability. Consistent with this finding, recordings from virally tagged PrL parvalbumin interneurons (PVINs) demonstrated that AIE exposure reduced both E/I balance at BLA inputs onto PVINs and PVIN intrinsic excitability. These findings provide compelling evidence that AIE alters synaptic function and intrinsic excitability within a prefrontal nociceptive circuit.

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.

Race explains substantial variance in whole blood thiamine diphosphate concentrations

Deficiency for thiamine (vitamin B1), traditionally assessed via the activity of the thiamine-dependent enzyme erythrocyte transketolase, has been reported in individuals with alcohol use disorder (AUD) and in people with HIV; concentrations of the metabolically active diphosphate form, however, have yet to be reported in HIV cohorts and results in AUD are equivocal. In this cross-sectional study, samples from 170 AUD, 130 HIV, and 100 healthy control individuals were analyzed to test the hypothesis that AUD and HIV groups relative to healthy controls would show low whole blood thiamine diphosphate (TDP) concentrations related to peripheral neuropathy. TDP concentrations were not different in the 3 study groups (P = .6141) but were lower in Black (n = 172) relative to White (n = 155) individuals (P < .0001) regardless of group. In a multiple regression, race relative to diagnoses explained more than 10 times the variance in whole blood TDP concentrations (F4,395 = 3.5, P = .0086; r2 = 15.1]. Performance on a measure of peripheral neuropathy (2-point discrimination) was worse in the HIV and AUD cohorts relative to the healthy control group (P < .0001) but was not associated with TDP concentrations. These findings suggest that Black individuals carry a heightened vulnerability for low whole blood TDP concentrations, but the clinical significance and mechanisms underlying these results remain to be determined.

Impact of Comorbidities on Sensory Return After Breast Reconstruction

PURPOSE

Breast anesthesia after mastectomy and reconstruction has been an ongoing concern with few improvements made in recent years. At present, there is a lack of studies evaluating the impact of comorbidities on sensation restoration. Identifying risk factors (RF) will be helpful with preoperative counseling.

METHODS

This was a prospective study on patients who underwent mastectomy and immediate implant-based or neurotized deep inferior epigastric perforator (DIEP) flap-based reconstruction. Neurosensory testing was performed at predefined time points using a pressure specified device. Patients were stratified based on reconstruction type and comorbidities, including obesity (≥30 kg/m2), age (>55 years), hypertension, alcohol use, and smoking status. Sensory comparisons among the comorbidity groups were conducted using unpaired 2-sample t tests.

RESULTS

A total of 239 patients were included in this study with 109 patients in the implant cohort and 131 patients in the DIEP cohort. One patient underwent bilateral reconstruction using both reconstructive modalities. Preoperatively, age older than 55 years was identified as an RF for reduced breast sensation in the implant cohort (difference in threshold, 10.7 g/mm2), whereas obesity was identified as an RF in the DIEP cohort (difference in threshold, 8 g/mm2). During the first 2 years postreconstruction, age older than 55 years and tobacco use history were found to be negatively correlated with breast sensation for both cohorts. With DIEP reconstruction specifically, obesity was identified as an additional RF during the early postoperative period. Of note, none of the comorbidities were found to be long-term RFs for reduced breast sensitivity. All breast sensation levels returned to comparable levels across all comorbidities by 4 years postreconstruction.

CONCLUSIONS

Currently, various comorbidities have been recognized as RFs for several postoperative complications including extended postoperative stay, necrosis, infection, and reoperation. However, our findings suggest that, although age, smoking history, and obesity showed transient associations with reduced breast sensation during the initial years postreconstruction, they play no role in the long-term potential of sensory nerve regeneration.

Self-medication of pain and discomfort with alcohol and other substances by people with HIV infection and substance use disorder: preliminary findings from a secondary analysis

There is a limited literature regarding factors associated with self-medication of pain and discomfort using alcohol, non-prescription substances or overuse of prescription medications among people living with Human Immunodeficiency Virus (HIV). This cross-sectional analysis used data from the Boston ARCH Cohort among participants with HIV infection and a history of alcohol or other substance use. Among 248 participants, 37% were female, 50% Black, 25% Latinx; 36% reported fair to poor health and 89% had CD4 cell counts >200/mm3. Half reported self-medication and of those, 8.8% reported doing so only with alcohol, 48.8% only with other substances and 42.4% with both alcohol and other substances. Those reporting self-medication were significantly (p < .05) younger (mean 47 vs 50 years), less employed (11% vs 21%), and less likely to have HIV viral suppression (60% vs. 80%). Depression, anxiety, and HIV symptoms were associated with significantly greater odds of self-medicating, as were substance dependence, recent injection substance use, heavy alcohol use, cocaine use, opioid use, sedative use, and cannabis use. Self-medication, highly prevalent and associated with worse mental health symptoms, greater substance use, and lesser HIV disease control, should be explored by HIV clinicians caring for people who use substances.

Elevated liver enzymes and fasting glucose levels correlate with neuropathy in patients diagnosed with alcohol use disorder independently of the blood thiamine levels

AIMS

Chronic alcohol consumption is well known to cause peripheral neuropathy, affecting both small and large nerve fibers. The aim of this study was to correlate biochemical and neurophysiological findings and investigate possible biomarkers and risk factors for pathogenetic mechanisms of neuropathy in patients diagnosed with alcohol use disorder (AUD).

METHODS

Ninety patients diagnosed with AUD were enrolled in this prospective study over a period of 3 years. Serum biochemical parameters, as well as thiamine blood levels, were determined upon admission. Every subject was assessed by clinical neurological examination, followed by Nerve Conduction Studies, Quantitative Sensory Testing, and Sympathetic Skin Response. Fifty age and gender-matched patients without a diagnosis of AUD were used as the control group.

RESULTS

Peripheral neuropathy was diagnosed in 54 patients (60%). Among them, pure large fiber neuropathy was found in 18 patients, pure small fiber neuropathy in 12 patients, and both large and small fiber neuropathy was diagnosed in 24 patients. Elevated liver enzymes and fasting glucose levels upon admission were significantly correlated with neuropathy. Lower blood thiamine levels (than reference) were found in seven patients and were not correlated with neuropathy.

CONCLUSIONS

Our study suggests that alcohol-related liver dysfunction and hyperglycemia may contribute as risk factors of peripheral neuropathy in patients diagnosed with AUD, while blood thiamine levels do not correlate with neuropathy. Moreover, we suggest that liver enzymes and the De Ritis ratio could be potentially used as biomarkers for the incidence and severity of alcohol-related neuropathy.

Approach to non-compressive myeloneuropathy through a rendezvous of 11 cases from an Indian backdrop

Introduction

Myeloneuropathy is a diagnosis ascribed to disorders that concomitantly affect the spinal cord and peripheral nerves. Recognizing this syndrome may sometimes be arduous, even for the most consummate clinicians, because symptomatology can mimic either spinal cord or peripheral nerve disease. Besides, examination findings suggest a predominantly myelopathic or neuropathic picture. This article reports a rendezvous of rare cases of clinically diagnosed myeloneuropathy with different etiological backgrounds and therapeutic responses.

Methods

Eleven cases of non-compressive myeloneuropathy were admitted to the Department of General Medicine of Burdwan Medical College and Hospital, Burdwan, West Bengal, India, between May 2018 and May 2022.

Results

We report the cases of 11 patients (6 men and 5 women) who presented with myeloneuropathy of different etiologies (vitamin B12, copper, and vitamin E deficiencies, organophosphate poisoning, chronic alcohol abuse, illicit substances abuse, anti-thyroid peroxidase/anti-thyroglobulin antibody-related neurologic disorder responsive to steroids, Sjögren syndrome, chikungunya infection, paraneoplastic, and hereditary).

Conclusion

Meticulous historical analysis, careful clinical examination, and apposite utilization and interpretation of biochemical, electrophysiological, and neuroimaging findings are sine-qua-non for an accurate and consistent approach to evaluating a suspected case of myeloneuropathy, facilitating early treatment and recovery. Differential identification of these disorders needs an in-depth perception of the mode of onset of symptoms, the course of progression of the disease, the pattern of myelopathic/neuropathic findings, and recognition of other neurological or systemic manifestations. For untroubled understanding, etiologies of myeloneuropathies should be subdivided into a few broad categories, e.g., metabolic (nutritional), toxic (toxin-induced), infectious, inflammatory (immune-mediated), paraneoplastic, and hereditary disorders.

Peripheral sensory neuropathy is associated with circulating angiopoietins in type 2 diabetes patients in Ghana

Objective

Peripheral sensory neuropathy (PSN) is a common complication of type 2 diabetes (T2DM) that can lead to frequent ulcerations, lower extremities, and reduced quality of life. Imbalance in the circulating levels of angiogenic growth factors, notably, angiopoietin (Ang)-1, Ang-2 and vascular endothelial growth factor (VEGF) may be among the underlying mechanisms of PSN in T2DM patients. We studied the association between PSN and angiogenic growth factors, Ang-1, Ang-2 and VEGF in T2DM patients in Ghana.

Methods

In a case-control study design, PSN was evaluated in 160 patients with T2DM and 108 nondiabetic controls using vibration perception threshold (VPT) and diabetic neurological examination (DNE). The definition of PSN was abnormal VPT (≥25 mV) or the presence of neuropathic symptoms on examination (DNE score > 3). In addition, fasting venous blood samples were collected to measure circulating levels of Ang-1, Ang-2 and VEGF.

Results

Compared to non-diabetic controls, patients with T2DM had a higher prevalence of PSN using abnormal VPT (20.6 % vs 2.8 %, p < 0.001) or neuropathic symptoms (35.6 % vs 3.7 %, p < 0.001). Compared to nondiabetic controls, patients with T2DM had increased levels of Ang-2 [597 (274 - 1005) vs 838 (473 - 1241) ng/ml, p = 0.018] and VEGF [48.4 (17.4 - 110.1) vs 72.2 (28 - 201.8), p = 0.025] and decreased Ang-1 levels [41.1 (30 - 57.3) vs 36.1 (24.7 - 42.1) ng/ml, p = 0.01]. In regression analyses, an increase in Ang-1 levels was associated with decreased odds, while an increase in Ang-2 levels was associated with increased odds, of abnormal VPT and neuropathic symptoms in T2DM patients.

Conclusion

In our study population, PSN was associated with reduced plasma levels of Ang-1 and increased plasma levels of Ang-2 in patients with T2DM. Therefore, an imbalance of angiopoietins may be associated with PSN in T2DM.

Approach to diagnosis, evaluation, and treatment of generalized and nonlocal dysesthesia: A review

Dysesthesia is an abnormal sensation in the skin that occurs in the absence of any extraordinary stimulus or other primary cutaneous disorders, excluding any delusions or tactile hallucinations. Clinicians have characterized dysesthesias to include sensations such as burning, tingling, pruritus, allodynia, hyperesthesia, or anesthesia. The etiology and pathogenesis of various generalized dysesthesias is largely unknown, though many dysesthesias have been associated with systemic pathologies including malignancy, infection, autoimmune disorders, and neuropathies. Dermatologists are often the first-line clinicians for patients presenting with such cutaneous findings, thus it is crucial for these physicians to be able to methodically work-up generalized dysesthesias to build a working differential diagnosis, follow up with key labs and/or imaging, and offer patients evidence-based treatment to relieve their symptoms. This broad literature review is an attempt to centralize key studies, cases, and series to help guide dermatologists in their assessment and evaluation of complaints of abnormal cutaneous sensations.

Alcohol and Skeletal Muscle in Health and Disease

PURPOSE

Alcohol-related myopathy is one of the earliest alcohol-associated pathological tissue changes that is progressively exacerbated by cumulative long-term alcohol misuse. Acute and chronic alcohol use leads to changes in skeletal muscle mass and function. As discussed in this evidence-based review, alcohol-mediated mechanisms are multifactorial with effects on anabolic and catabolic signaling, mitochondrial bioenergetics, extracellular matrix remodeling, and epigenomic alterations. However, systematic studies are limited, especially regarding the acute effects of alcohol on skeletal muscle.

SEARCH METHODS

This review focuses on peer-reviewed manuscripts published between January 2012 and November 2022 using the search terms "alcohol" or "ethanol" and "skeletal muscle" in MEDLINE, PubMed, and Web of Science using EndNote reference management software.

SEARCH RESULTS

Eligible manuscripts included full-length research papers that discussed acute and chronic effects of alcohol on skeletal muscle mass and function in both clinical and preclinical studies. The review also includes alcohol-mediated skeletal muscle effects in the context of comorbidities. The three databases together yielded 708 manuscripts. Of these, the authors excluded from this review 548 papers that did not have "alcohol" or "muscle" in the title and 64 papers that were duplicates or did not discuss skeletal muscle. Thus, of all the manuscripts considered for this review, 96 are included and 612 are excluded. Additionally, relevant papers published earlier than 2012 are included to provide context to the review.

DISCUSSION AND CONCLUSIONS

Both acute and chronic alcohol use decrease protein synthesis and increase protein degradation. Alcohol also impairs mitochondrial function and extracellular matrix remodeling. However, there is a gap in the literature on the known alcohol-mediated mechanisms, including senescence, role of immune activation, and interorgan communication, on the development of alcohol-related myopathy. With increased life expectancy, changing alcohol use patterns, and increasing frequency of alcohol use among females, current observational studies are needed on the prevalence of alcohol-related myopathy. Additionally, the compounding effects of acute and chronic alcohol use on skeletal muscle with aging or exercise, in response to injury or disuse, and in the context of comorbidities including diabetes and human immunodeficiency virus (HIV), call for further investigation. Though evidence suggests that abstinence or reducing alcohol use can improve muscle mass and function, they are not restored to normal levels. Hence, understanding the pathophysiological mechanisms can help in the design of therapeutic strategies to improve skeletal muscle health.

The Role of Micronutrients in Neurological Disorders

Trace elements and vitamins, collectively known as micronutrients, are essential for basic metabolic reactions in the human body. Their deficiency or, on the contrary, an increased amount can lead to serious disorders. Research in recent years has shown that long-term abnormal levels of micronutrients may be involved in the etiopathogenesis of some neurological diseases. Acute and chronic alterations in micronutrient levels may cause other serious complications in neurological diseases. Our aim was to summarize the knowledge about micronutrients in relation to selected neurological diseases and comment on their importance and the possibilities of therapeutic intervention in clinical practice.

What's New in Neuropathy?

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

Longitudinal assessment of strength and body composition in a mouse model of chronic alcohol-related myopathy

BACKGROUND

Excessive, chronic alcohol consumption can result in muscle atrophy and weakness (i.e., alcoholic myopathy) that impairs the quality of life. However, the precise mechanisms responsible for ethanol's detrimental impact on skeletal muscle have not been fully elucidated, in part due because the time course of disease development and progression are not well established. Therefore, we examined muscle strength and body composition longitudinally using an established preclinical mouse model of chronic alcoholic myopathy.

METHODS

To establish a time course of chronic alcoholic myopathy, we fed High Drinking in the Dark (HDID) female mice (n = 7) 20% ethanol for ~32 weeks (following a 2-week ethanol ramping period). We assessed in vivo isometric contractility of the left ankle dorsiflexor and lean mass via NMR every 4 weeks. Outcomes were compared with age-matched control HDID mice that did not consume ethanol (n = 8).

RESULTS

At study completion, mice who consumed ethanol were 12% weaker than control mice (p = 0.015). Compared to baseline, consuming ethanol resulted in an acute transient reduction in dorsiflexion torque at Week 4 (p = 0.032) that was followed by a second, more sustained reduction at Week 20 (p < 0.001). Changes in lean mass paralleled those of dorsiflexor torque, with ~40% of the variance in dorsiflexor torque being explained by the variance in lean mass of the ethanol group (p < 0.001). Dorsiflexor torque normalized to lean mass (mN·m/g lean mass) did not differ between the ethanol and control groups from Weeks 4 to 32 (p ≥ 0.498).

CONCLUSIONS

These results indicate that reductions in muscle mass and strength due to chronic, excessive ethanol intake are dynamic, not necessarily linear, processes. Moreover, the findings confirm that ethanol-induced weakness is primarily driven by muscle atrophy (i.e., loss of muscle quantity). Future studies should consider how chronic alcoholic myopathy develops and progresses rather than identifying changes after it has been diagnosed.

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.

Excessive Ethanol Intake in Mice Does Not Impair Recovery of Torque after Repeated Bouts of Eccentric Contractions

PURPOSE

Alcoholics develop muscle atrophy and weakness from excessive ethanol (EtOH) intake. To date, most research has examined outcomes of alcohol-induced atrophy and weakness under basal or unstressed conditions despite physical stress being a normal occurrence in a physiological setting. Therefore, this study set out to determine if recovery of torque is impaired after repetitive bouts of physical stress in skeletal muscle during excessive short-term (experiment 1) and long-term (experiment 2) EtOH consumption.

METHODS

Twenty male and female mice were assigned to receive either 20% EtOH in their drinking water or 100% water. Short- and long-term consumption was predetermined to be EtOH intake starting at 4 and 26 wk, respectively. Anterior crural muscles performed repeated bouts of physical stress using in vivo eccentric contractions, with tetanic isometric torque being measured immediately pre- and postinjury. A total of 10 bouts were completed with 14 d between each bout within bouts 1-5 (experiment 1) and bouts 6-10 (experiment 2), and 12 wk between bouts 5 and 6.

RESULTS

Mice consuming EtOH had blood alcohol concentrations up to 270 mg·dL -1 . In experiment 1, five bouts of eccentric contractions did not reduce recovery of torque, regardless of sex or EtOH treatment ( P ≥ 0.173). Similarly, in experiment 2, preinjury torques did not differ from day 14 values regardless of sex or treatment ( P ≥ 0.322). However, there was a group effect in female mice for bouts 6 and 10 during experiment 2, with female EtOH mice being weaker than controls ( P ≤ 0.002).

CONCLUSIONS

Excessive short- or long-term EtOH misuse in a mouse model did not affect the muscle's ability to regain strength after repeated bouts of eccentric contractions, suggesting that EtOH may not be as detrimental to recovery as once predicted.

Oral Cannabidiol does not alter Alcohol Seeking and Self-Administration in Baboons

BACKGROUND

The cannabinoid cannabidiol (CBD) is currently under investigation as a pharmacotherapy for alcohol use disorder. The aim of the present study was to examine whether acute and chronic treatment with pure CBD would decrease alcohol seeking and consumption behaviors or alter drinking patterns in male baboons with extensive histories of daily alcohol intake (1 g/kg/day).

METHODS

Seven male baboons self-administered oral alcohol (4% w/v) in a validated chained schedule of reinforcement (CSR) procedure that modeled periods of anticipation, seeking, and consumption. In Experiment 1, CBD (5-40 mg/kg) or vehicle (peanut oil, USP) was administered orally 15- or 90-minutes prior to the start of the session. In Experiment 2, oral doses of CBD (10-40 mg/kg) or vehicle were administered for 5 consecutive days during ongoing alcohol access under the CSR. In addition, behavioral observations were conducted to assess potential drug side effects (e.g., sedation, motor incoordination) following chronic CBD treatment immediately after the session and 24-hours after drug administration.

RESULTS

Across both experiments, baboons self-administered an average of 1 g/kg/day of alcohol under baseline conditions. Administration of acute or chronic CBD (150-1200 mg total CBD dose/day) that encompassed the purported therapeutic dose range did not significantly reduce alcohol seeking, self-administration or intake (g/kg). Drinking patterns (i.e., number of drinks/bouts, bout duration, nor interdrink interval) also were not altered. There were no observable behavioral disruptions following CBD treatment.

CONCLUSIONS

In sum, the current data do not support use of pure CBD as an effective pharmacotherapy to reduce ongoing excessive drinking.

Toxic neuropathies: a practical approach

Toxic neuropathies result from exogenous substances damaging the peripheral nerves. There are numerous causes, including prescribed and recreational drugs, heavy metals, industrial agents and biological toxins. Timely recognition of these neuropathies gives better outcomes, as they usually improve or stabilise once the toxin is removed. Most toxic neuropathies are axonal, length-dependent and sensory predominant, although some have significant motor involvement or can present acutely or subacutely. Here, we outline our clinical approach and discuss the major causes of toxic neuropathy, while emphasising the clinical and neurophysiological features and the neuropathy phenotype. We also include an update on newer medications that can cause neuropathy, including immune checkpoint inhibitors and BRAF/MEK inhibitors.

Chronic pain in Chile: first prevalence report of noncancer chronic pain, fibromyalgia, and neuropathic pain and its associated factors

ABSTRACT

Although we know chronic pain (CP) affects approximately 30% of people in developed countries, data from Latin America are scarce. Moreover, prevalence of specific CP conditions, such as chronic noncancer pain (CNCP), fibromyalgia (FM), and neuropathic pain (NP), is unknown. To estimate them in Chile, we prospectively enrolled 1945 participants (61.4% women and 38.6% men), aged 38 to 74 years, from an agricultural town who answered a Pain Questionnaire, the Fibromyalgia Survey Questionnaire, and Douleur Neuropathique 4 (DN4) to identify CNCP, FM, and NP, respectively. The estimated prevalence of CNCP was 34.7% (95% CI 32.6; 36.8), with an average duration of 32.3 months (SD ± 56.3), producing deep impairments in daily activities, sleep, and mood. We estimated a prevalence of 3.3% for FM (95% CI 2.5; 4.1) and 12% for NP (95% CI 10.6; 13.4). Female sex, fewer school years, and depressive symptoms were associated with FM and NP, whereas diabetes was only associated with NP. We standardized the results from our sample against the whole Chilean population and found no significant difference to our crude estimates. This is in line with studies from developed countries, highlighting the idea that despite genetic and environmental differences, the conditions that confer risk to CNCP remain stable.

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 differences in neuromuscular disorders

The prevalence, onset, pathophysiology, and clinical course of many neuromuscular disorders (NMDs) may significantly differ between males and females. Some NMDs are more frequently observed in females, and characterized to show a higher grade of severity during or after the pregnancy. Meanwhile, others tend to have an earlier onset in males and exhibit a more variable progression. Prevalently, sex differences in NMDs have a familiar character given from genetic inheritance. However, they may also influence clinical presentation and disease severity of acquired NMD forms, and are represented by both hormonal and genetic factors. Consequently, to shed light on the distinctive role of biological factors in the different clinical phenotypes, we summarize in this review the sex related differences and their distinctive biological roles emerging from the current literature in both acquired and inherited NMDs.

Role of tubulin post-translational modifications in peripheral neuropathy

Peripheral neuropathy is a common disorder that results from nerve damage in the periphery. The degeneration of sensory axon terminals leads to changes or loss of sensory functions, often manifesting as debilitating pain, weakness, numbness, tingling, and disability. The pathogenesis of most peripheral neuropathies remains to be fully elucidated. Cumulative evidence from both early and recent studies indicates that tubulin damage may provide a common underlying mechanism of axonal injury in various peripheral neuropathies. In particular, tubulin post-translational modifications have been recently implicated in both toxic and inherited forms of peripheral neuropathy through regulation of axonal transport and mitochondria dynamics. This knowledge forms a new area of investigation with the potential for developing therapeutic strategies to prevent or delay peripheral neuropathy by restoring tubulin homeostasis.

Electrophysiologic Characteristics of Nitrous-Oxide-Associated Peripheral Neuropathy: A Retrospective Study of 76 Patients

BACKGROUND AND PURPOSE

The electrophysiologic characteristics of peripheral neuropathy secondary to nitrous oxide (N₂O) abuse remain unclear. The paper therefore aimed to summarize the electrophysiologic characteristics of N₂O-associated peripheral neuropathy and identify the risk factors of severe nerve injury.

METHODS

The electrophysiologic results and clinical data of patients with peripheral neuropathy secondary to N₂O abuse at our hospital between 2018 and 2020 were analyzed retrospectively, and their electrophysiologic changes were summarized.

RESULTS

Most patients exhibited decreased sensory and motor nerve conduction velocities (75% and 76%), decreased sensory nerve and compound motor action potentials (57% and 59%), and prolonged distal motor latency (59%), while a response was absent in 36%. These findings indicate that N₂O abuse can result in generalized injury to sensory and motor nerves. Electrophysiologic results indicated axonal neuropathy in 37 cases (49%), demyelinating peripheral neuropathy in 4 (5%), and mixed neuropathy in 12 (16%). Peripheral nerve injury was more common in the lower limbs (72%) than in the upper limbs (42%, p<0.0001). The upper and lower limbs were primarily affected by sensory nerve demyelination (35%) and motor axonal injury (67%), respectively. Subgroup analysis indicated that longer N₂O exposure and longer disease course were associated with more-severe motor axonal injury in the lower limbs.

CONCLUSIONS

N₂O-associated peripheral neuropathy can lead to sensory and motor nerve injury, with axonal injury being the most common. Injuries were more severe in the lower limbs. Prolonged N₂O exposure and disease course increased the severity of motor axonal injury in the lower limbs.

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.

TRPV4 Role in Neuropathic Pain Mechanisms in Rodents

Neuropathic pain is a chronic pain caused by a disease or damage to the somatosensory nervous system. The knowledge about the complete mechanisms is incomplete, but the role of oxidative compounds has been evaluated. In this context, we highlight the transient potential receptor vanilloid 4 (TRPV4), a non-selective cation channel, that can be activated by oxidated compounds. In clinical trials, the TRPV4 antagonist (GSK2798745) has been well-tolerated in healthy volunteers. The TRPV4 activation by oxidative compounds, such as hydrogen peroxide (H₂O₂) and nitric oxide (NO), has been researched in neuropathic pain models. Thus, the modulation of TRPV4 activation by decreasing oxidated compounds could represent a new pharmacological approach for neuropathic pain treatment. Most models evaluated the TRPV4 using knockout mice, antagonist or antisense treatments and detected mechanical allodynia, hyposmotic solution-induced nociception and heat hyperalgesia, but this channel is not involved in cold allodynia. Only H₂O₂ and NO were evaluated as TRPV4 agonists, so one possible target to reduce neuropathic pain should focus on reducing these compounds. Therefore, this review outlines how the TRPV4 channel represents an innovative target to tackle neuropathic pain signaling in models induced by trauma, surgery, chemotherapy, cancer, diabetes and alcohol intake.

Identification of factors affecting outcomes in patients with Guillain Barre syndrome

Background

Guillain Barre syndrome (GBS) is a rare autoimmune neurological disorder resulting in variable clinical course and outcome. Various factors such as age, symptoms and disease form that influence the outcome of GBS have been previously studied.

Aim

This study aimed at identifying factors affecting the outcomes in patients with GBS.

Methods

A retrospective observational study was conducted on GBS (ICD-G61.0) patients admitted to the hospital between 2014 and 2019. Patient information on demographics, medical and medication history, laboratory parameters, electrophysiological data, type of GBS and therapy received were retrieved from medical records. Univariate and multivariate analysis were conducted to identify factors associated with outcome (improved and not improved) and calculate odds ratio (OR).

Results

A total of 212 GBS patients were included in the study, of which 67% were males and the mean age was 39.9±20.1 years. 168 (79%) patients showed improvement whereas the remaining 44(21%) did not show improvement. Patients with hypertension (OR=4.512; CI=1.309-15.556, p=0.017), alcoholics (OR=5.148; CI=1.234-21.472, p=0.025), sepsis (OR= 9.139; CI=1.102-75.760, p=0.040) and cardiac arrest (OR=17.495; CI=1.249-245.027, p=0.034) were associated with risk of no improvement. Whereas those treated with IVIgG plus Physiotherapy/Occupational therapy (OR=0.062; CI=0.016-0.242, p=0.001) and Plasmapheresis plus Physiotherapy/Occupational therapy (OR=0.007; CI=0.000-0.147, p=0.001) were associated with improvement.

Conclusion

Understanding these factors help to further give a more directed and focused management to improve the condition in patients who are at risk of poor outcome. Further follow-up studies could be done to determine and manage the residual disabilities associated with GBS to improve patient's quality of life.

Acil Servise Başvuran Metil Alkol Zehirlenmelerinin Geriye Dönük Analizi

Objective: Methyl alcohol poisoning remains a significant cause of mortality and morbidity. This poisoning is still one of the important reasons for admission to emergency services. We aimed to examine the admission complaints, laboratory findings, treatment methods, clinical outcomes and examine the factors affecting the mortality of patients diagnosed with methyl alcohol poisoning in the emergency department. Methods: In this retrospective descriptive study, we analysed the patients who were considered to be diagnosed with methyl alcohol intoxication among those who came to our emergency department due to alcohol intoxication from June 1, 2018 to June 1, 2020. Results: The study included 20 (4.86%) individuals with methyl alcohol poisoning among 411 people who presented to the emergency department due to ethyl and methyl alcohol intake and resulting effects.The mean age of the patients was 47.35±14.2 years and 85% (n=17/20) were male. Upon reviewing the patients' admission symptoms, 70% were observed to have visual problems, 60% complaints of vomiting, 45% shortness of breath, and 40% changes in consciousness. In the study, it was revealed that 18.2%(n=2/11) females and 81.8%(n=9/11) males died, and the mortality rate was calculated as 55%(n=11/20). Conclusions: The presence of visual problems, hypotension, and coma in clinical findings, high anion gap metabolic acidosis, marked osmolar gap, an increase in lactate level, and hyperglycemia in laboratory findings may be the early signs of mortality in patients with methyl alcohol poisoning. Therefore, patients with these signs should be followed up more closely and treated.

Insight into Lotusine and Puerarin in Repairing Alcohol-Induced Metabolic Disorder Based on UPLC-MS/MS

Alcohol is an essential element in human culture. However, alcoholism has contributed to numerous health issues, including alcoholic fatty liver and sudden death. We found that the alkaloid lotusine possessed hepato- and neuroprotection against alcohol injuries. Lotusine showed comparable protective effects to puerarin, a widely recognized antagonist against alcohol damage. To better understand the metabolic response to alcohol injury and antagonist molecules, we applied sensitive zebrafish and LC-ESI-MS to collect metabolites related to alcohol, puerarin and lotusine exposure. LC-MS identified 119 metabolites with important physiological roles. Differential metabolomic analysis showed that alcohol caused abnormal expression of 82 metabolites (60 up-regulated and 22 down-regulated). These differential metabolites involved 18 metabolic pathways and modules, including apoptosis, necroptosis, nucleotide and fatty acid metabolism. Puerarin reversed seven metabolite variations induced by alcohol, which were related to necroptosis and sphingolipid metabolism. Lotusine was found to repair five metabolites disorders invoked by alcohol, mainly through nucleotide metabolism and glutathione metabolism. In phenotypic bioassay, lotusine showed similar activities to puerarin in alleviating behavioral abnormalities, neuroapoptosis and hepatic lipid accumulation induced by alcohol exposure. Our findings provided a new antagonist, lotusine, for alcohol-induced damage and explored the roles in repairing abnormal metabolism.

Extrahepatic Manifestations in Alcoholic Liver Disease

Though liver is the most commonly affected organ in patients with chronic and excessive intake of alcohol, no organ is immune to toxic effects of alcohol and patients with alcohol-related liver disease (ALD) can suffer from a wide list of extrahepatic manifestations involving gastrointestinal tract, central and peripheral nervous systems, cardio vascular system, musculo-skeletal system, disruption of nutritional status, endocrinological abnormalities, hematological abnormalities and immune dysfunction. These extrahepatic organ involvements are usually overlooked by hepatologists and physicians who are mostly focused on managing life threatening complications of ALD. As a result, there is delayed diagnosis, delay in the initiation of appropriate treatment and late referral to other specialists. Some of these manifestations are of utmost clinical importance (e.g. delirium tremans and Wernicke's encephalopathy) because an early diagnosis and treatment can lead to full recovery while delayed or no treatment can result in death. On the other hand, several extrahepatic manifestations are of prognostic significance (such as alcoholic cardiomyopathy and malignancies) in which there is an increased risk of morbidity and mortality. Hence, a clear understanding and awareness of the extrahepatic manifestations of ALD is quintessential for proper management of these patients.

Neuromuscular mechanisms of weakness in a mouse model of chronic alcoholic myopathy

BACKGROUND

Weakness is a common clinical symptom reported in individuals with chronic alcohol use disorder. However, it remains unclear whether low strength in these individuals is directly related to excessive ethanol intake, other deleterious factors (lifestyle, environment, genetics, etc.), or a combination of both. Therefore, we examined whether (and how) ethanol reduces the muscle's force-producing capacity using a controlled in vivo preclinical mouse model of excessive ethanol intake.

METHODS

To establish whether chronic ethanol consumption causes weakness, C57BL/6 female mice consumed 20% ethanol for 40 weeks (following a 2-week ethanol ramping period), and various measures of muscular force were quantified. Functional measures included all-limb grip strength and in vivo contractility of the left ankle dorsiflexors and plantarflexors. Once confirmed that mice consuming ethanol were weaker than age-matched controls, we sought to determine the potential neuromuscular mechanisms of muscle dysfunction by assessing neuromuscular excitation, muscle quantity, and muscle quality.

RESULTS

Mice consuming chronic ethanol were 13 to 16% weaker (p ≤ 0.016) than controls (i.e., mice consuming 100% water) with the negative impact of ethanol on voluntary grip strength (ƞ²  = 0.603) being slightly larger than that of electrically stimulated muscle contractility (ƞ²  = 0.482). Relative to controls, lean mass and muscle wet masses were 9 to 16% lower in ethanol-consuming mice (p ≤ 0.048, ƞ²  ≥ 0.268). No significant changes were observed between groups for indices of neuromuscular excitation at the level of the motor unit, neuromuscular junction, or plasmalemma (p ≥ 0.259, ƞ²  ≤ 0.097), nor was muscle quality altered after 40 weeks of 20% ethanol consumption (p ≥ 0.695, ƞ²  ≤ 0.012).

CONCLUSIONS

Together, these findings establish that chronic ethanol consumption in mice induces a substantial weakness in vivo that we interpret to be primarily due to muscle atrophy (i.e., reduced muscle quantity) and possibly, to a lesser degree, loss of central neural drive.

Perineural Capsaicin Treatment Inhibits Collateral Sprouting of Intact Cutaneous Nociceptive Afferents

Perineural treatment of peripheral nerves with capsaicin produces a long-lasting selective regional thermo- and chemo-analgesia and elimination of the neurogenic inflammatory response involving degeneration of nociceptive afferent fibers. In this study, we examined longitudinal changes in mustard oil–induced sensory neurogenic vasodilatation and plasma extravasation following perineural capsaicin treatment of the rat saphenous nerve utilizing scanning laser Doppler imaging and vascular labeling with colloidal silver. Capsaicin treatment resulted in a marked decrease in mustard oil–induced vasodilatation in the skin area served by the saphenous nerve. Repeated imaging of the vasodilatatory response showed no recovery for at least 7 weeks. However, following transection and ligation of the capsaicin-treated saphenous nerve, a substantial recovery of the vasodilatatory response was observed, suggesting a reinnervation of the chemodenervated skin area by collateral sprouting of neighboring intact sciatic nerve afferents. Elimination of the recovered vascular reaction by capsaicin treatment of the sciatic nerve supported this conclusion. Similar results have been obtained by using the vascular labeling technique. These findings indicate an inhibitory effect of persisting cutaneous nerve fibers on the collateral sprouting of intact nerve fibers into the chemodenervated skin area. These observations may bear implications for the development of sensory disturbances following peripheral nerve injuries.

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.

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.

Complications of Ethanolic Withdrawal in Hospitalized Patients

Chronic alcohol consumption, also called alcoholism, is a chronic disease characterized by compulsive alcohol consumption, loss of control over alcohol consumption and a negative emotional state in the absence/lack of consumption. Statistics show that the incidence of alcohol consumption in the adult population has been increasing during the isolation due to the pandemic. It is fre-quently associated with the consumption of other substances, in which case mortality is higher than in the case of single alcohol consumption. The patterns of alcohol consumption are varied, being related to a series of demographic, social, psychological and behavioral variables. The most worrying aspect of alcohol consumption is represented by the increase in the frequency of this type of addiction among teenagers and young people. It should also be mentioned that there is an increase in the incidence in females and there are new variables related to the context of consumption: increased boredom, alcohol consumption for the purpose of relaxation and alcohol consumption as an activity in the absence of an entourage. During the pandemic, there was also the myth that alcohol consumption would be the basis for reducing the risk of contamination with the SARS CoV 2 virus, an aspect disproved by specialist studies. The increased consumption of alcohol during the pandemic could be correlated with anxiety and depression determined by the fear of illness and depression due to the loss of the job, the lack of social relations or online education, being unanimously accepted that alcohol has an anxiolytic role. Regarding ethanolic withdrawal (EW) symptoms, studies show that approximately 50% of patients with chronic alcohol consumption will develop withdrawal symptoms when they reduce the quantity of alcohol or stop drinking alcohol.

South African men and women living with HIV have similar distributions of pain sites

Background

No studies have investigated sex differences in the location and number of pain sites in people living with human immunodeficiency virus (HIV) (PLWH), despite evidence that women, in general, bear a greater burden of pain than men.

Aim

To determine sex differences in the location and number of pain sites, and whether there were demographic or disease-related differences in the number of pain sites.

Setting

South African tertiary hospital HIV clinics and a community healthcare centre

Methods

We conducted a retrospective analysis of records from South African PLWH who had pain.

Results

Of the 596 participant records, 19% were male (115/596) and the median number of pain sites for both sexes was 2 (interquartile range [IQR]: 1 to 3). Pain was most frequently experienced in the head (men: 12%, women: 38%), feet and ankles (men: 42%, women: 28%), abdomen (men = 19%, women = 28%) and chest (men = 20%, women = 20%). After correcting for multiple comparisons, males were less likely to experience headache than females (Fisher’s exact text, odds ratio [OR] = 0.23, 95% confidence interval [CI]: 0.12 – 0.42, p = 0.000). Pain at other body sites was experienced similarly between the sexes. There was no meaningful variation in the number of pain sites between the sexes (logistic regression, p = 0.157).

Conclusion

A similar location and number of pain sites were experienced by male and female South African PLWH. The locations of pain sites were different from previous reports, however, suggesting that research into pain in PLWH cannot necessarily be generalised across cultures.

Integrated Care of Alcohol-Related Liver Disease

BACKGROUND/AIMS

Alcohol-related liver disease (ALD) is the medical manifestation of alcohol use disorder, a prevalent psychiatric condition. Acute and chronic manifestations of ALD have risen in recent years especially in young people and ALD is now a leading indication of liver transplantation (LT) worldwide. Such alarming trends raise urgent and unanswered questions about how medical and psychiatric care can be sustainably integrated to better manage ALD patients before and after LT.

METHODS

Critical evaluation of the interprofessional implications of broad and multifaceted ALD pathophysiology, general principles of and barriers to interprofessional teamwork and care integration, and measures that clinicians and institutions can implement for improved and integrated ALD care.

RESULTS

The breadth of ALD pathophysiology, and its numerous medical and psychiatric comorbidities, ensures that no single medical or psychiatric discipline is adequately trained and equipped to manage the disease alone.

CONCLUSIONS

Early models of feasible ALD care integration have emerged in recent years but much more work is needed to develop and study them. The future of ALD care is an integrated approach led jointly by interprofessional medical and psychiatric clinicians.

Alcohol use and interoception - A narrative review

Interoception, defined as the ability to perceive and interpret body signals, may play an important role in alcohol use disorder (AUD). Earlier studies suggested an association between interoception impairment and known risk factors for AUD (e.g., alexithymia, emotion dysregulation, impulsivity, pain). Neurobiological studies show that the neurotoxicity of alcohol affects various elements of the interoceptive system (especially the insula) at structural and functional levels, with differential short/long term impacts. Conversely, primary interoceptive impairments may promote alcohol consumption and foster the evolution towards addiction. Despite convincing evidence demonstrating that interoception impairment may be an important contributor to the development and course of AUD, only a few studies directly evaluated interoceptive abilities in AUD. The research shows that interoceptive accuracy, the objective component of interoception, is lower in AUD individuals, and is correlated with craving and emotion dysregulation. Interoceptive sensibility is in turn higher in AUD individuals compared to healthy controls. Moreover, there is evidence that therapy focused on improving the ability to sense signals from the body in addiction treatment is effective. However, important methodological limitations in interoceptive measures persist, and it is therefore necessary to further investigate the associations between interoception and AUD.

Adjuvant physical exercise for the management of painful polyneuropathy

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Peripheral polyneuropathy from electrodiagnostic tests: a 10-year etiology and neurophysiology overview

BACKGROUND

Polyneuropathies are characterized by a symmetrical impairment of the peripheral nervous system, resulting in sensory, motor and/or autonomic deficits. Due to the heterogeneity of causes, an etiological diagnosis for polyneuropathy is challenging.

OBJECTIVE

The aim of this study was to determine the main causes of polyneuropathy confirmed by electrodiagnostic (EDX) tests in a tertiary service and its neurophysiological aspects.

METHODS

This observational cross-sectional study from a neuromuscular disorders center included individuals whose electrodiagnostic tests performed between 2008 and 2017 confirmed a diagnosis of polyneuropathy. Through analysis of medical records, polyneuropathies were classified according to etiology and neurophysiological aspect.

RESULTS

Of the 380 included patients, 59.5% were male, with a median age of 43 years. The main etiologies were: inflammatory (23.7%), hereditary (18.9%), idiopathic (13.7%), multifactorial (11.1%), and diabetes (10.8%). The main electrophysiological patterns were axonal sensorimotor polyneuropathy (36.1%) and "demyelinating and axonal" sensorimotor polyneuropathy (27.9%). Axonal patterns showed greater etiological heterogeneity, with a predominance of idiopathic and multifactorial polyneuropathy, while demyelinating and "demyelinating and axonal" polyneuropathies had a significantly fewer etiologies, with a predominance of hereditary and inflammatory polyneuropathies.

CONCLUSION

The main causes of polyneuropathy confirmed by EDX test in this study were those that presented a severe, atypical and/or rapidly progressing pattern. Other causes were hereditary and those that defy clinical reasoning, such as multiple risk factors; some polyneuropathies did not have a specific etiology. EDX tests are useful for etiological diagnosis of rare polyneuropathies, because neurophysiological patterns are correlated with specific etiologies.

Sudomotor dysfunction in patients with gluten neuropathy

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Persistent neuropathy among early-stage breast cancer survivors in a population-based cohort

BACKGROUND

The prevalence of persistent peripheral neuropathy (PN) in early-stage breast cancer (ESBC) survivors is largely unknown. We explored the occurrence and risk factors of PN among long-term ESBC survivors treated with taxane chemotherapy.

METHODS

A population-based cohort of 884 recurrence-free ESBC survivors diagnosed 2010-2015 in the South East Health Care region, Sweden and 1768 control women without prior cancer received a postal questionnaire that included the European Organisation for Research and Treatment of Cancer chemotherapy-induced peripheral neuropathy (CIPN20) items. Prevalence, relative risks (RRs) (Poisson regression) and risk factors (binomial regression) were calculated. Adjustments were made for confounding factors (e.g. age, body mass index, comorbidities).

RESULTS

The response rate was 79% for survivors and 59% for controls. The median time post taxane was 3.6 years (1.5-7.3 years). The adjusted RR was highest (RR 1.8) for "tingling/numbness of toes/feet". Individual sensory symptoms occurred in 8.9-48.4% and motor symptoms in 7.2-61.3% of survivors; the most prevalent symptoms were "difficulty opening jar" and "cramps in feet". Paclitaxel, older age, overweight, diabetes mellitus, vibrating hand tools, autoimmune disease and smoking were independent risk factors.

CONCLUSIONS

PN was more common among ESBC survivors than control women and many symptoms persisted over time. Risk factors should be considered when treatment decisions are made.

Co-occurrence of Marchiafava-Bignami Disease and Alcoholic Polyneuropathy in Chronic Alcoholic Patient Who Had Past History of Wernicke Encephalopathy: a Case Report

Marchiafava-Bignami disease (MBD), Wernicke encephalopathy (WE) and alcoholic polyneuropathy (AP) are distinct diseases and all have strong relationship with chronic alcoholism. A 70-year-old male who had altered mentality and ataxia of both lower limbs and had past history of WE 3 years previously admitted with 6 months history of impaired walking. He also had a symptom of altered sensorium by impaired consciousness for 2 days. In brain magnetic resonance imaging, the body, splenium of corpus callosum and bilateral frontal cortex were involved. The patient was diagnosed with MBD on the basis of the clinical features and the brain imaging findings. The electrodiagnostic findings implied demyelinating neuropathy in all extremities. He failed to recover his mentality and the function of the limbs remained poor finishing several treatment options including medications and physical therapy. The poor prognosis of this patient is thought to be associated with cortical involvement of MBD. We reported this very rare case who was affected by 3 distinct diseases of MBD, AP, and WE as complications of chronic alcohol abuse. Moreover, the case was relevant to a rare clinical presentation of MBD with cortical involvement which was associated with poor prognosis.

[Polyneuropathies during COVID-19 epidemics]

Our review article aimed for analysis of pathogenesis, diagnostyics and treatment of polyneuropathies manifesting in the course of COVID-19. The reasons for hyposmia and taste disturbances are considered in the subjects with this coronavirus infection as well as relationship between these clinical manifestations and severity of the viral infection. Special attention is given to description of autoimmune mechanisms of Guillain-Barré syndrome and polyneuropathies of critical conditions associated with COVID-19. Some data report about clinical deterioration of diabetic and alcoholic neuropathy during the SARS-CoV-2 infection. Inclusion of group B vitamins, together with C and D vitamins, is recommended to the schedules of combined treatment for polyneuropathies in these patients. Early diagnostics of polyneuropathies, especially, Guillain-Barré syndrome, is required during COVID-19 pandemics, thus helping to administer rational therapy and promoting better quality of life in the patients.

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.