Assessing nerves in leprosy

Case report: Myelitis and ganglionitis, an atypical presentation of Hansen's disease

Hansen's disease, or leprosy, is a disease characterized by dermatological and neurological disorders. A neural form also exists, in which peripheral neuropathy occurs in the absence of skin lesions. However, cases of leprosy that involve the central nervous system and proximal nerves are rare in the literature. We describe the case of an oligosymptomatic patient diagnosed with the neural form of leprosy with involvement of peripheral nerves, dorsal root ganglion, and cervical spinal cord in an atypical presentation of the disease. Through complementary examinations and nerve biopsies, the bacillus was identified, and treatment was subsequently initiated. This case highlights the importance of investigating the suspicion of leprosy, even in cases with atypical manifestations, as early diagnosis and treatment can reduce neurological damage and deformities.

The role of neurotrophin polymorphisms and susceptibility to neural damage in leprosy

OBJECTIVES

Mycobacterium leprae is able to infect Schwann cells leading to neural damage. Neurotrophins are involved in nervous system plasticity and impact neural integrity during diseases. Investigate the association between single nucleotide polymorphisms in neurotrophin genes and leprosy phenotypes, especially neural damage.

DESIGN

We selected single nucleotide polymorphisms in neurotrophins or their receptors genes associated with neural disorders: rs6265 and rs11030099 of brain-derived neurotrophic factor (BDNF), rs6330 of BDNF, rs6332 in NT3 and rs2072446 of P75NTR. The association of genetic frequencies with leprosy phenotypes was investigated in a case-control study.

RESULTS

An association of the BDNF single nucleotide polymorphism rs11030099 with the number of affected nerves was demonstrated. The "AA+AC" genotypes were demonstrated to be protective against nerve impairment. However, this variation does not affect BDNF serum levels. BDNF is an important factor for myelination of Schwann cells and polymorphisms in this gene can be associated with leprosy outcome. Moreover, rs11030099 is located in the binding region for micro-RNA (miRNA) 26a that could be involved in control of BDNF expression. We demonstrated different expression levels of this miRNA in polar forms of leprosy.

CONCLUSION

Our findings demonstrate for the first time an association between the polymorphism rs11030099 in the BDNF gene and neural commitment in leprosy and may indicate a possible role of miRNA-26a acting synergistically to these genetic variants in neural damage development.

The International Classification of Functioning, Disability and Health to map leprosy-related disability in rural and remote areas in Indonesia

The International Classification of Function, Disability, and Health (ICF-WHO, 2001) recognizes several dimensions of disability, such as body structure and function (and impairment thereof), activity (and activity restrictions) and participation (and participation restriction) and their interactions with contextual factor (personal and environmental). In this study, we map and analyse the relationship between the components of ICF in leprosy patients from two rural areas in Indonesia: Lewoleba (East Nusa Tenggara) and Likupang (North Minahasa). This study was part of a community outreach program by the KATAMATAKU team from Universitas Indonesia. The body structure was graded using the WHO hand and feet disability grade and the number of enlarged nerves, while the body function was measured by the Jebsen Taylor Hand Function Test (JTT) and Timed-up and Go (TUG). Activity limitation and participation restriction were measured using the Screening Activity Limitation Safety Awareness (SALSA) Scale and Participation Scale (P-scale), respectively. There were 177 leprosy patients from the two regions and 150 patients with complete data were included in the analysis. We found 82% (95% CI: 75.08%-87.32%) of subjects with multibacillary leprosy, 10.67% (95% CI: 6.67%-16.62%) of subjects with grade 2 WHO hand disability, and 9.33% (95% CI: 5.64%-15.06%) of subjects with grade 2 WHO foot disability. Assessment using the SALSA Scale showed 29.33% of subjects with limitation activity and 11.33% with participation restriction. Age was shown to have positive correlations with SALSA, JTT, and TUG. Inter-dimensional analysis showed that the SALSA scale had significant positive correlations with the number of nerve enlargements, P-scale, JTT, and TUG. SALSA scores of grade 2 WHO hand and foot disability were also significantly higher than grades 1 and 0. The participation scale also had a positive correlation with JTT but not TUG. Hand disability seemed to affect societal participation while foot did not. We used the ICF to describe and analyse dimensions of leprosy-related disability in Indonesia.

Case report: Injected corticosteroids for treating leprosy isolated neuritis

One of the main manifestations of leprosy is peripheral nerve impairment. Early diagnosis and treatment are important to reduce the impact of neurological impairment, which can cause deformities and physical disabilities. Leprosy neuropathy can be acute or chronic, and neural involvement can occur before, during, or after multidrug therapy, and especially during reactional episodes when neuritis occurs. Neuritis causes loss of function in the nerves and can be irreversible if left untreated. The recommended treatment is corticosteroids, usually through an oral regimen at an immunosuppressive dose. However, patients with clinical conditions that restrict corticosteroid use or that have focal neural involvement may benefit from the use of ultrasound-guided perineural injectable corticosteroids. In this study, we report two cases that demonstrate how the treatment and follow-up of patients with neuritis secondary to leprosy, using new techniques, can be provided in a more individualized way. Nerve conduction studies in association with neuromuscular ultrasound were used to monitor the response to treatment with injected steroids, focusing on neural inflammation. This study provides new perspectives and options for this profile of patients.

Ultrasonography as a diagnostic tool for Neural Pain in Leprosy

Leprosy is still a prevalent disease in Brazil, representing 93% of all occurrences in the Americas. Leprosy neuropathy is one of the most worrying manifestations of the disease. Acute neuropathy usually occurs during reaction episodes and is called neuritis. Twenty-two leprosy patients were included in this study. These patients had neural pain associated with ulnar sensory neuropathy, with or without adjunct motor involvement. The neurological picture began within thirty days of the clinical evaluation. The patients underwent a nerve conduction study and the demyelinating findings confirmed the diagnosis of neuritis. Ultrasonographic study (US) of the ulnar nerve was performed in all patients by a radiologist who was blinded to the clinical or neurophysiological results. Morphological characteristics of the ulnar nerve were analyzed, such as echogenicity, fascicular pattern, transverse cross-sectional area (CSA), aspect of the epineurium, as well as their anatomical relationships. The volume of selected muscles referring to the ulnar nerve, as well as their echogenicity, was also examined. Based on this analysis, patients with increased ulnar nerve CSA associated with loss of fascicular pattern, epineurium hyperechogenicity and presence of power Doppler flow were classified as neuritis. Therefore, patients initially classified by the clinical-electrophysiological criteria were reclassified by the imaging criteria pre-established in this study as with and without neuritis. Loss of fascicular pattern and flow detection on power Doppler showed to be significant morphological features in the detection of neuritis. In 38.5% of patients without clinical or neurophysiological findings of neuritis, US identified power Doppler flow and loss of fascicular pattern. The US is a method of high resolution and portability, and its low cost means that it could be used as an auxiliary tool in the diagnosis of neuritis and its treatment, especially in basic health units.

Leprosy remains a public health problem, despite being an ancient disease. In most cases, it is associated with neuropathy that can be acute or chronic and this neural involvement can occur before, during, or after multidrug therapy (MDT). Acute neuropathy usually occurs during reaction episodes and is called neuritis. It causes compromised nerve function associated with nociceptive pain [1]. The inflammatory process can also develop neuroplasticity of the peripheral and central nervous systems, which perpetuates this sensation; this phenomenon is known as neuropathic pain, a chronic sensation in leprosy. Differential diagnosis between nociceptive and neuropathic pain is not always easy and in some patients there may be an overlap between nociceptive and neuropathic pain. Currently, clinical and electrophysiological criteria are used for the differential diagnosis of neural pain [2], but especially in the case of recurrent neuritis, these criteria are insufficient. Recent knowledge about pain mechanisms does not define the limit as to where nociceptive ends and neuropathic begins, suggesting that this process is continuous, in addition to being associated. Ultrasonography (US) has been used as an auxiliary tool in the early diagnosis of peripheral nervous system diseases. The method can be implemented in addition to clinical and neurophysiological studies for the diagnosis of neuritis, which allows for the early identification and treatment of the disease [3,4].

Follow-up assessment of patients with Pure Neural Leprosy in a reference center in Rio de Janeiro—Brazil

Introduction

Pure Neural Leprosy (PNL) is a rare clinical form of leprosy in which patients do not present with the classical skin lesions but have a high burden of the disability associated with the disease. Clinical characteristics and follow up of patients in PNL are still poorly described in the literature.

Objective

This paper aims to describe the clinical, electrophysiological and histopathological characteristics of PNL patients, as well as their evolution after multidrug therapy (MDT).

Methods

Fifty-two PNL patients were selected. Clinical, nerve conduction studies (NCS), histopathological and anti-PGL-1serology were evaluated. Patients were also assessed monthly during the MDT. At the end of the MDT, all of the patients had a new neurological examination and 44 were submitted to another NCS.

Results

Paresthesia was the complaint most frequently reported by patients, and in the neurological examination the most common pattern observed was impairment in sensory and motor examination and a mononeuropathy multiplex. Painful nerve enlargement, a classical symptom of leprosy neuropathy, was observed in a minority of patients and in the motor NCS axonal injuries, alone or in combination with demyelinating features, were the most commonly observed. 88% of the patients did not present any leprosy reaction during MDT. There was no statistically significant difference between the neurological examinations, nor the NCS pattern, performed before and after the MDT.

Discussion

The classical hallmarks of leprosy neuropathy are not always present in PNL making the diagnosis even more challenging. Nerve biopsy is an important tool for PNL diagnosis as it may guide therapeutic decisions. This paper highlights unique characteristics of PNL in the spectrum of leprosy in an attempt to facilitate the diagnosis and management of these patients.

Neuropathy is responsible for most of the disability associated with leprosy disease. The pure neural leprosy (PNL), in spite of being a rare clinical presentation of that, has some singular characteristics that are still poorly studied. In this study, we selected 52 patients at the diagnosis to describe their clinical, neurophysiological and histopathological presentation patterns as well as their evolution during the multidrug therapy (MDT). We confirmed that sensitive symptoms were the most commonly described by PNL patients but neural pain is rare. Also confirmed that mononeuropathy mutiplex was the most common pattern observed at neurological examination and at the nerve conduction studies at the moment of the diagnosis. However we showed that painful nerve enlargement other cardinal signs of leprosy, besides the skin lesions, is not common in this group of patients, There was no statistically significant difference between the neurological examination and NCS performed before and after the MDT.During the MDT88.4% of the patients did not have any leprosy reaction. This may suggest that that MDT was effective in stopping disease progression. Our results highlight the difficulties in the diagnosis of PNL and the progression following MDT in an attempt to prevent further disability in PNL patients.

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.

Late follow-up of peripheral neural decompression in leprosy: functional and clinical outcomes

BACKGROUND

Peripheral neural surgical decompression (PNSD) is used as a complementary therapy to the clinical treatment of neuritis to preserve neural function.

OBJECTIVE

To evaluate the long-term (≥ 1 year) clinical and functional results for PNSD in leprosy neuritis.

METHODS

This cross-sectional study included leprosy patients who were in late postoperative period (LPO) of surgical decompression of ulnar, median, tibial, and fibular nerves. Socioeconomic, epidemiological, and clinical data were collected. The following instruments were used in this evaluation: visual analogue pain scale (VAS), Douleur Neuropathique en 4 Questions (DN4), SALSA scale, and simplified neurological assessment protocol. The preoperative (PrO) and 180-day postoperative (PO180) results were compared.

RESULTS

We evaluated 246 nerves from 90 patients: 56.6% were on multidrug therapy (MDT) and 43.3% discharged from MDT. Motor scores and pain intensity showed statistically significant improvement (p<0.01). There was an increase in sensory scores only for bilateral ulnar nerves (p<0.05). Of the operated cases, 26.0% of patients were referred for surgery of ulnar neuritis and 23.6% of tibial neuritis. Neuropathic pain was reported in 41% of cases. Daily dose of prednisone reduced from 39.6 mg (±3.0) in PrO, 16.3 mg (±5.2) in PO180, to 1.7 mg (±0.8) in LPO. The SALSA scale results showed mild activity limitation in 51% and moderate in 34% of patients. Eighty percent of individuals reported that the results reached their expectations.

CONCLUSIONS

PNSD in leprosy was effective in the long term to decrease the prevalence and intensity of pain, improve motor function, and reduce the dose of corticosteroids, which is reflected in the patients' satisfaction.

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.

Comparison between nerve conduction study and high-resolution ultrasonography with color doppler in type 1 and type 2 leprosy reactions

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Identifying leprosy reactions is important to prevent disability.

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HRUS with CD can be useful compared to NCS to diagnose acute inflammatory activity.

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HRUS with CD helps reactions diagnosis in minimal and complete NCS abnormalities.

Objective

To analyze the role of high-resolution ultrasonography with color Doppler (HRUS with CD) to diagnose inflammatory activity (IA) in nerves of leprosy patients under type 1 (RT1) and 2 (RT2) reactions compared to Nerve Conduction Studies (NCS).

Methods

Leprosy patients with signs or symptoms suggestive of neuritis (RT1 and RT2) without corticosteroids use were selected. They were evaluated by NCS and subsequently by HRUS with CD. Subacute segmental demyelination and the presence of blood flow, respectively, were considered signs of IA. The two methods were compared for their ability to diagnose patients with leprosy reactions.

Results

A total of 257 nerves from 35 patients were evaluated. NCS and HRUS with CD diagnosed IA in 68% and 74% of patients, respectively. When both methods were used concomitantly, the diagnosis rate was 91.4%. HRUS with CD was particular helpful when there was minimal neurophysiological compromise in NCS or when motor potentials were not detected.

Conclusion

HRUS with CD was able to detect leprosy reactions, especially when combined with NCS. It was especially useful in two opposite situations: nerves with only minor changes and those without motor response in NCS.

Significance

Our data shows the usefulness of HRUS and CD, similar to NCS, as a tool to diagnose leprosy reactions.

Leprosy: Clinical aspects and diagnostic techniques

Leprosy, also known as Hansen's disease, is a curable infectious disease that remains endemic in >140 countries around the world. Despite being declared "eliminated" as a global public health problem by the World Health Organization in the year 2000, approximately 200,000 new cases were reported worldwide in 2017. Widespread migration may bring leprosy to nonendemic areas, such as North America. In addition, there are areas in the United States where autochthonous (person-to-person) transmission of leprosy is being reported among Americans without a history of foreign exposure. In the first article in this continuing medical education series, we review leprosy epidemiology, transmission, classification, clinical features, and diagnostic challenges.

Myelination key factor krox-20 is downregulated in Schwann cells and murine sciatic nerves infected by Mycobacterium leprae

Schwann cells (SCs) critically maintain the plasticity of the peripheral nervous system. Peripheral nerve injuries and infections stimulate SCs in order to retrieve homeostasis in neural tissues. Previous studies indicate that Mycobacterium leprae (ML) regulates the expression of key factors related to SC identity, suggesting that alterations in cell phenotype may be involved in the pathogenesis of neural damage in leprosy. To better understand whether ML restricts the plasticity of peripheral nerves, the present study sought to determine the expression of Krox-20, Sox-10, c-Jun and p75NTR in SC culture and mice sciatic nerves, both infected by ML Thai-53 strain. Primary SC cultures were stimulated with two different multiplicities of infection (MOI 100:1; MOI 50:1) and assessed after 7 and 14 days. Sciatic nerves of nude mice (NU-Foxn1nu ) infected with ML were evaluated after 6 and 9 months. In vitro results demonstrate downregulation of Krox-20 and Sox-10 along with the increase in p75NTR-immunolabelled cells. Concurrently, sciatic nerves of infected mice showed a significant decrease in Krox-20 and increase in p75NTR. Our results corroborate previous findings on the interference of ML in the expression of factors involved in cell maturation, favouring the maintenance of a non-myelinating phenotype in SCs, with possible implications for the repair of adult peripheral nerves.

Evaluation of the cutaneous sensation of the face in patients with different clinical forms of leprosy

Background

Leprosy can be considered to be the most common peripheral neuropathy of infectious etiology and constitutes a public health problem. The standard routine examination for assessing sensory impairment in leprosy neuropathy basically evaluates hands, feet and eyes. However, evaluation of facial cutaneous sensation is not routinely performed.

Objectives

The aim of this study was to evaluate facial cutaneous sensation in patients with different clinical forms of leprosy and compare the findings with those from healthy individuals.

Methodology

19 healthy controls and 71 leprosy patients who were being treated at a national reference center for leprosy in Brazil underwent facial sensation assessment using the Semmes-Weinstein monofilament test. This test was applied over the facial areas corresponding to the ophthalmic, maxillary and mandibular distal branches of the trigeminal nerve.

Results

The predominant clinical form in terms of changes to facial cutaneous sensation was lepromatous leprosy (LL), followed by the borderline-borderline (BB), and borderline-lepromatous (BL) forms, in comparison with healthy individuals. The distal branches most affected were the zygomatic (28.2%; 20/71), buccal (23.9%; 17/71) and nasal (22.5%; 16/71). There was asymmetrical sensory impairment of the face in 62.5% (20/32) of the cases.

Conclusion

The face is just as impaired in leprosy as are the feet, hands and eyes, but facial impairment is underdiagnosed. Our evaluation on the different sensory branches and evidence of asymmetrical impairment of the face confirm the classically described pattern of leprosy neuropathy, i.e. consisting of asymmetrical and predominantly sensory peripheral neuropathy.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Mycobacterium leprae-induced nerve damage: direct and indirect mechanisms

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. This disease is characterized by skin and peripheral nerve trunk damage. The mechanisms responsible for the observed nerve damage in leprosy could be directly related to the ability of M. leprae to infect Schwann cells, leading to triggering of signaling events. Therefore, we hypothesize that in response to M. leprae infection, activation of the Notch signaling pathway in Schwann cells could play a crucial role in glial cell dedifferentiation. On the other hand, nerve damage evidenced in this disease may be additionally explained by indirect mechanisms such as the immune response and genetic susceptibility of the host. The understanding of the mechanisms leading to nerve damage induced by M. leprae infection will allow us to generate valuable tools for the early detection of leprosy as well as for the mitigation of the effects of this disabling disease.