Diagnosis and impact of neuropathic pain in leprosy patients in Nepal after completion of multidrug therapy

Leprosy: The age-old companion of humans - Re-evaluation and comparative analysis of Avar-period cases with Hansen's disease from the Danube-Tisza Interfluve, Hungary

In recent years, our knowledge of leprosy in the past has substantially been enriched. Nonetheless, much still remains to be discovered, especially in regions and periods from where no written sources are available. To fill in some research gaps, we provide the comparative analysis of eight Avar-period leprosy cases from the Danube-Tisza Interfluve (Hungary). In every case, to reconstruct the biological consequences of leprosy, the detected bony changes were linked with palaeopathological and modern medical information. To reconstruct the social consequences of being affected by leprosy, conceptualisation of the examined individuals' treatment in death was conducted. In every case, the disease resulted in deformation and disfigurement of the involved anatomical areas (rhinomaxillary region, feet, and/or hands) with difficulties in conducting certain physical activities. These would have been disadvantageous for the examined individuals and limited or changed their possibilities to participate in social situations. The most severe cases would have required continuous support from others to survive. Our findings indicate that, despite their very visible disease and associated debility, the examined communities did not segregate leprosy sufferers but provided and cared for them, and maintained a strong enough social network that made their survival possible even after becoming incapable of self-sufficiency.

The efficacy of a whole foods, plant-based dietary lifestyle intervention for the treatment of peripheral neuropathic pain in leprosy: a randomized control trial protocol

Introduction

Despite effective treatment of leprosy via WHO-approved multi-drug therapy (MDT), patients still suffer from debilitating neuropathic sequelae, including peripheral neuropathic pain (PNP), and continue to develop intercurrent etiologies (such as diabetes), and progressive existing neuropathy over time. Strategies seeking to improve physiological and metabolic wellness, including those that reduce systemic inflammation and enhance immune responsiveness to neurotoxic factors may influence underlying neuropathic etiologies. A whole food plant-based diet (WFPBD) has been shown to be effective in the management of neuropathic pain due to diabetes, limiting severity and relevant symptomology. Diabetes remains a significant sequela of leprosy, as up to 50% of patients in reaction requiring corticosteroids, may develop a biochemical diabetes. As nutritional interventions may modulate both leprosy and diabetes, a specific exploration of these relationships remains relevant.

Objectives

(1) To demonstrate the effect of a WFPBD lifestyle intervention, on neuropathic pain variables in leprosy; and (2) To contextualize the significance of diet in the treatment of chronic sequelae in leprosy by evaluating tolerability and side effect profile.

Methods

A prospective, randomized, controlled, single-blind, multicentre interventional trial is described. Weekly one-hour dietary counseling sessions promoting a WFPBD emphasizing vegetables, fruits, whole-grains, nuts, and legumes, omitting animal products, and limiting fat intake over a six-month duration will be implemented. Participants will be 70 age and sex-matched individuals experiencing active or treated "cured" leprosy and PNP, randomized to either intervention or control groups. Primary outcome measures include efficacy via visual analog scale, subjective questionnaire and objective quantitative sensory testing, as well as safety, tolerability, and harms of a WFPBD on PNP in leprosy. This study will be initiated after Research Ethics Board (REB) approval at all participating sites, and in advance of study initiation, the trial will be registered at ClinicalTrials.gov.

Expected impact

It is hypothesized that WFPBDs will mitigate progression and severity of PNP and potentially reduce the adverse events related to standard corticosteroid treatment of leprosy reactions, thereby reducing disease severity. By examining the effects of WFPBDs on PNP in leprosy, we hope to illuminate data that will lead to the enhanced therapeutic management of this neglected tropical disease.

Assessment of neuropathic pain, functional activity limitation and quality of life of people affected by leprosy in an endemic area in Northeast Brazil: a cross-sectional study

BACKGROUND

This study investigated the prevalence of neuropathic pain (NP) among people affected by leprosy and its effects on functional limitation and health-related quality of life (HRQoL) in an endemic area in Northeast Brazil.

METHODS

This is a cross-sectional study of 122 leprosy patients. Functional limitation and HRQoL were assessed using the Screening of Activity Limitation and Safety Awareness (SALSA) and WHO Quality-of-Life (WHOQoL-BREF) scales, respectively. Participants were assessed for the presence of pain and completed the Douleur Neuropathique 4 and the Brief Pain Inventory scales.

RESULTS

The prevalence of NP was 59%. Participants with NP had higher SALSA scores than those without pain (median; IQR: 42; 32-49.5 vs 27.5; 24-34; p=0.002). Increasing SALSA scores were related to decreasing WHOQoL-BREF scores in the physical (r=-0.54; p<0.001), psychological (r=-0.33; p=0.002) and environmental (r=-0.22; p=0.01) domains, but not in the social domain (r=-0.14; p=0.10). Individuals with NP had the lowest scores in all domains compared with individuals without pain.

CONCLUSIONS

Appropriate tools and training of clinicians for diagnosing NP in leprosy patients are necessary for their appropriate management and better HRQoL outcomes.

A review of nutrition in neuropathic pain of leprosy

Leprosy is a neglected tropical disease (NTD) that continues to burden low- and middle-income countries (LMICs), despite being eliminated as a public health concern by the World Health Organization (WHO) in 2000. The causative agents, Mycobacterium leprae and Mycobacterium lepromatosis, affect nearly 200,000 individuals globally each year, with over 19,000 new cases detected in the Americas in 2020 alone. Canada has experienced an increasing incidence of leprosy, due to rising levels of travel and migration from endemic areas, reaching over 37,000 individuals with leprosy by the end of 2020. Patients experience a spectrum of signs and symptoms including hypopigmented cutaneous macules alongside peripheral neuropathy including peripheral neuropathic pain (PNP) and disabling sensory neuropathies. Despite the development of effective and curative therapeutics via multidrug therapy (MDT), many barriers to treatment adherence and effective immunological control of the pathogen challenge the care of patients with leprosy. Socioeconomic barriers, such as disability-related social stigma and often undiagnosed nutritional deficiencies, have resulted in heightened disease severity. PNP therapeutics are associated with significant side effects and remain ineffective as the majority of individuals will not experience a greater than 30% reduction of symptoms. Nutrient supplementation is known to be instrumental in reducing host oxidative stress, strengthening the immune system and mitigating comorbidities. Likewise, dietary lifestyle interventions known to be physiologically beneficial have recently emerged as powerful tools conferring neuroprotective effects, potentially mitigating PNP severity. However, a significant knowledge gap concerning the effect of adequate nutrition on host immunological control of leprosy and PNP severity exists. Further evaluation of this relationship will provide key insight into the pathogenesis of leprosy, strengthening the current body of literature.

Chronic pain and infection: mechanisms, causes, conditions, treatments, and controversies

Throughout human history, infection has been the leading cause of morbidity and mortality, with pain being one of the cardinal warning signs. However, in a substantial percentage of cases, pain can persist after resolution of acute illness, manifesting as neuropathic, nociplastic (eg, fibromyalgia, irritable bowel syndrome), or nociceptive pain. Mechanisms by which acute infectious pain becomes chronic are variable and can include immunological phenomena (eg, bystander activation, molecular mimicry), direct microbe invasion, central sensitization from physical or psychological triggers, and complications from treatment. Microbes resulting in a high incidence of chronic pain include bacteria such as the Borrelia species and Mycobacterium leprae, as well as viruses such as HIV, SARS-CoV-2 and herpeses. Emerging evidence also supports an infectious cause in a subset of patients with discogenic low back pain and inflammatory bowel disease. Although antimicrobial treatment might have a role in treating chronic pain states that involve active infectious inflammatory processes, their use in chronic pain conditions resulting from autoimmune mechanisms, central sensitization and irrevocable tissue (eg, arthropathy, vasculitis) or nerve injury, are likely to cause more harm than benefit. This review focuses on the relation between infection and chronic pain, with an emphasis on common viral and bacterial causes.

Clinical and electrophysiological characteristics of neuropathic pain in leprosy patients: A prospective cross-sectional study

INTRODUCTION

Neuropathic pain is a common and disabling late complication of leprosy. We investigated the clinical and electrophysiological characteristics of neuropathic pain in leprosy patients by evaluating nerve conduction, sympathetic skin response (SSR) and A-waves.

METHODS

Twenty one leprosy patients with neuropathic pain validated by the Douleur Neuropathique en 4 (DN4)Questionnaire were selected for study. Pain intensity was measured by the visual analog scale. Demographic and clinical data were collected for all patients. Clinical data included appraisal of the median, ulnar, radial, tibial and common peroneal nerves, assessment of the sympathetic skin response and conventional electrophysiological recordings.

RESULTS

Among all electroneuromyographic presentations, multifocal mononeuropathy was still the most prevalent. Sensory loss was observed more frequently than motor deficits. As most patients presented advanced clinical forms of leprosy and were under treatment, this high mean was found and the ulnar nerve was most frequently affected. The sympathetic skin response was absent in 16 patients. Higher DN4 Questionnaire scores were observed in women and in those receiving corticosteroid therapy. These inferences are possible to be made, but our study's limitations don't allow us to be certain about it. The statistical significance found only permits us to evidence what we related on the textual part of the study.

LIMITATIONS

The small number of patients studied, the lack of sophisticated diagnostic methods for leprosy, as well as the difficulties in assessing nerve conduction were the main limitations of this study.

CONCLUSION

The neurophysiological and clinical findings in leprous neuropathy were modest despite the conspicuous neuropathic pain. Although electrophysiological studies are a vital tool to verify nerve damage, variations in the clinical presentation of leprosy neuropathic pain render the diagnosis challenging. Further studies are needed to describe the neurophysiological evolution of this disease.

Assessment of neuropathic pain in leprosy patients with relapse or treatment failure by infrared thermography: A cross-sectional study

BACKGROUND

Neuropathic pain (NP) is one of the main complications of leprosy, and its management is challenging. Infrared thermography (IRT) has been shown to be effective in the evaluation of peripheral autonomic function resulting from microcirculation flow changes in painful syndromes. This study used IRT to map the skin temperature on the hands and feet of leprosy patients with NP.

METHODOLOGY/PRINCIPAL FINDINGS

This cross-sectional study included 20 controls and 55 leprosy patients, distributed into 29 with NP (PWP) and 26 without NP (PNP). Thermal images of the hands and feet were captured with infrared camera and clinical evaluations were performed. Electroneuromyography (ENMG) was used as a complementary neurological exam. Instruments used for the NP diagnosis were visual analog pain scale (VAS), Douleur Neuropathic en 4 questions (DN4), and simplified neurological assessment protocol. The prevalence of NP was 52.7%. Pain intensity showed that 93.1% of patients with NP had moderate/severe pain. The most frequent DN4 items in individuals with NP were numbness (86.2%), tingling (86.2%) and electric shocks (82.7%). Reactional episodes type 1 were statistically significant in the PWP group. Approximately 81.3% of patients showed a predominance of multiple mononeuropathy in ENMG, 79.6% had sensory loss, and 81.4% showed some degree of disability. The average temperature in the patients' hands and feet was slightly lower than in the controls, but without a significant difference. Compared to controls, all patients showed significant temperature asymmetry in almost all points assessed on the hands, except for two palmar points and one dorsal point. In the feet, there was significant asymmetry in all points, indicating a greater involvement of the lower limbs.

CONCLUSION

IRT confirmed the asymmetric pattern of leprosy neuropathy, indicating a change in the function of the autonomic nervous system, and proving to be a useful method in the approach of pain.

Perception of cure among leprosy patients post completion of multi-drug therapy

BACKGROUND

Leprosy is a treatable disease; however, the release from treatment after completion of multidrug therapy (MDT) often does not equal absence of health problems. Consequently, sequelae interfere with the patient's perception of cure. The objective of this study was to analyze the factors associated with the perception of not being healed among people treated for leprosy in a highly endemic area in Brazil.

METHOD

A cross-sectional study of perceived cure of leprosy in the post-release from treatment period was conducted in Cáceres in the state of Mato Grosso, Brazil. The study included a total of 390 leprosy patients treated with MDT and released after completion of treatment from 1 January 2000 to 31 December 2017. The dependent variable was self-reported cure of leprosy; the independent variables included clinical, operational and socioeconomic variables.

RESULTS

Out of the 390 former leprosy patients, 304 (77.9%) perceived themselves as cured and 86 (22.1%) considered themselves unhealed. Among the latter, 49 (57.0%) reported muscle weakness and joint pains. Individuals with complaints related to leprosy post-release from treatment had a 4.6 times higher chance to self-report as unhealed (OR 4.6; 95% CI 2.5-8.5). Patients with physical disabilities (PD) grade 1 and 2 at the time of the study had a 3.1 (OR 3.1; 95% CI 1.3-7.4) and 8.8 (OR 7.7; 95% CI 3.5-21.9) times higher likelihood to self-identify as unhealed, respectively.

CONCLUSION

Among successfully treated leprosy patients, a quarter self-report as unhealed of the disease. The factors associated with the perception of being unhealed are PD and complaints related to leprosy in the post-release from treatment phase.

Clinical prediction rules for the diagnosis of neuritis in leprosy

Background

Diagnosing neuritis in leprosy patients with neuropathic pain or chronic neuropathy remains challenging since no specific laboratory or neurophysiological marker is available.

Methods

In a cross-sectional study developed at a leprosy outpatient clinic in Rio de Janeiro, RJ, Brazil, 54 individuals complaining of neural pain (single or multiple sites) were classified into two groups (“neuropathic pain” or “neuritis”) by a neurological specialist in leprosy based on anamnesis together with clinical and electrophysiological examinations. A neurologist, blind to the pain diagnoses, interviewed and examined the participants using a standardized form that included clinical predictors, pain features, and neurological symptoms. The association between the clinical predictors and pain classifications was evaluated via the Pearson Chi-Square or Fisher’s exact test (p < 0.05).

Results

Six clinical algorithms were generated to evaluate sensitivity and specificity, with 95% confidence intervals, for clinical predictors statistically associated with neuritis. The most conclusive clinical algorithm was: pain onset at any time during the previous 90 days, or in association with the initiation of neurological symptoms during the prior 30-day period, necessarily associated with the worsening of pain upon movement and nerve palpation, with 94% of specificity and 35% of sensitivity.

Conclusion

This algorithm could help physicians confirm neuritis in leprosy patients with neural pain, particularly in primary health care units with no access to neurologists or electrophysiological tests.

Chronic aspects of leprosy-neglected but important

The chronic aspects of leprosy are discussed here. They are a consequence of the peripheral nerve damage that affects many patients during their lifetime with leprosy. The peripheral nerve damage leaves people unable to feel and with weakness in their hands and feet. They are at risk of damaging their hands and feet, causing the disabilities and deformities that characterise late leprosy. More than 200 000 new leprosy patients are diagnosed globally each year. Better data are needed from cohort studies to estimate the number of patients developing nerve damage and modelling studies are needed to estimate the number of patients who develop disabilities. For some of them, this will be a lifelong disability. Nerve damage is caused by inflammation in leprosy-affected nerves. Patients with nerve damage of <6-mo duration need treatment with steroids. About 66% of multibacillary patients will develop nerve damage. Plastic graded monofilaments can be used to detect nerve damage in leprosy and diabetic clinics. Assessing nerve damage and treating patients with steroids in leprosy programmes needs to be strengthened. The World Health Organization has a successful programme for supplying antibiotics for treating leprosy infection to national leprosy programmes. They should take responsibility for providing steroids to national programmes since this is a core part of the treatment for >66% of multibacillary patients. Patients need to be asked about neuropathic pain symptoms and treated if necessary. Treated leprosy patients are at risk of developing ulcers in their feet. Treatment and prevention needs to be improved through health education, providing protective footwear and patient empowerment.

Exploring the Promise of Flavonoids to Combat Neuropathic Pain: From Molecular Mechanisms to Therapeutic Implications

Neuropathic pain (NP) is the result of irregular processing in the central or peripheral nervous system, which is generally caused by neuronal injury. The management of NP represents a great challenge owing to its heterogeneous profile and the significant undesirable side effects of the frequently prescribed psychoactive agents, including benzodiazepines (BDZ). Currently, several established drugs including antidepressants, anticonvulsants, topical lidocaine, and opioids are used to treat NP, but they exert a wide range of adverse effects. To reduce the burden of adverse effects, we need to investigate alternative therapeutics for the management of NP. Flavonoids are the most common secondary metabolites of plants used in folkloric medicine as tranquilizers, and have been claimed to have a selective affinity to the BDZ binding site. Several studies in animal models have reported that flavonoids can reduce NP. In this paper, we emphasize the potentiality of flavonoids for the management of NP.

State of clinical pain research in Nepal: a systematic scoping review

Supplemental Digital Content is Available in the Text.

Before determining the pain research priorities for a country, a comprehensive literature review of existing research is warranted. We aimed to (1) identify and describe the extent and nature of pain research performed in Nepal, (2) identify existing knowledge and significant knowledge gaps, and (3) provide recommendations for future studies. We conducted a systematic scoping review of the literature, in accordance with recommended guidelines. We searched local and international databases to identify research conducted in Nepal on individuals with a diagnosis of clinical pain conditions. A pair of independent reviewers screened the studies for inclusion. We identified 1396 records and included 116 studies. Most studies were published in Nepalese journals (75%) and were conducted in clinical settings (73%). Postsurgical pain was the most commonly studied pain condition (33%), followed by musculoskeletal pain (16%), headache (14%), and low back pain (13%). The most common research topics, in order of frequency, were (1) medical management (40%), (2) pain prevalence/incidence (21%), (3) diagnostic procedures (15%), (4) surgical management (8%), and (5) patient-reported outcome measurement (8%). Research gaps and potential areas of research waste were identified. Although a large number of research articles about pain in Nepal have been published, the majority of these have focused on the biomedical diagnosis and management of pain. Other topic areas (eg, psychological and social aspects of pain) are under-represented. The findings may inform future research directions for maximizing the knowledge that could be gained.