Pure neuritic leprosy: Current status and relevance

From periphery to center, untold story of pure neuritic leprosy: an electrophysiological study

BACKGROUND

Pure neuritic leprosy (PNL) is uncommon form of leprosy involving peripheral nerves. Some isolated case reports have shown imaging changes in the central nervous system (CNS) and also impairment in visual evoked potential (VEP), somatosensory evoked potential (SSEP) and brain stem auditory-evoked potentials (BAEPs) parameters in PNL, but there is lack of large study. This prospective observational study evaluates impairment in these central conduction studies among PNL patients.

METHODS

We screened patients with leprosy presenting with features of neuropathy and/or thickened nerves. Patients with bacilli-positive nerve biopsies were included in the study and subjected to routine tests along with nerve conduction study (NCS), VEP, tibial SSEP and BAEPs. Parameters of these studies were analyzed based on data from previous studies.

RESULTS

Of 76 patients screened for PNL 49 had positive findings in biopsy. Most of patients were male and mean age group was 46.35 ± 15.35 years. Mononeuritis multiplex was most common NCS pattern in 46.93% (23/49) patients. We found abnormal VEP in 13 out of 35 patients (37.14%). Similarly abnormal SSEP and BAEPs among 42.85% and 40% patients respectively.

DISCUSSION

This study shows that in PNL significant number of patients have subclinical CNS involvement. Exact pathophysiology of CNS involvement is not known till now but study of VEP, SSEP and BAEPs parameter may help in early diagnosis of PNL.

Neural leprosy investigation using electroneuromyography and the ML Flow rapid test: a case report

Neural leprosy, which is characterized by nerve involvement without visible skin lesions, presents a diagnostic challenge. This case report examined the significance of diverse diagnostic modalities in the identification of pure neural leprosy. A 28-year-old patient with symptoms of edema, pain, paresthesia, and diminished sensitivity in the lower limbs underwent various tests. A stilt skin smear yielded negative results on bacilloscopy, whereas a Fast ML Flow leprosy test and electroneuromyography supported the diagnosis. This discussion highlights the importance of accessible methods for early investigation. This study emphasizes the multidisciplinary approach and value of the Fast ML Flow leprosy test and electroneuromyography for diagnosing neural leprosy.

High-resolution ultrasonography for early diagnosis of neural impairment in seropositive leprosy household contacts

Leprosy household contacts (HC) represent a high-risk group for the development of the disease. Anti-PGL-I IgM seropositivity also increases the risk of illness. Despite significant advances in leprosy control, it remains a public health problem; and early diagnosis of this peripheral neuropathy represents one of the main goals of leprosy programs. The present study was performed to identify neural impairment in leprosy HC by analyzing differences in high-resolution ultrasonographic (US) measurements of peripheral nerves between leprosy HC and healthy volunteers (HV). Seventy-nine seropositive household contacts (SPHC) and 30 seronegative household contacts (SNHC) underwent dermato-neurological examination and molecular analysis, followed by high-resolution US evaluation of cross-sectional areas (CSAs) of the median, ulnar, common fibular and tibial nerves. In addition, 53 HV underwent similar US measurements. The US evaluation detected neural thickening in 26.5% (13/49) of the SPHC and only in 3.3% (1/30) among the SNHC (p = 0.0038). The CSA values of the common fibular and tibial nerves were significantly higher in SPHC. This group also had significantly greater asymmetry in the common fibular and tibial nerves (proximal to the tunnel). SPHC presented a 10.5-fold higher chance of neural impairment (p = 0.0311). On the contrary, the presence of at least one scar from the BCG vaccine conferred 5.2-fold greater protection against neural involvement detected by US (p = 0.0184). Our findings demonstrated a higher prevalence of neural thickening in SPHC and support the role of high-resolution US in the early diagnosis of leprosy neuropathy. The combination of positive anti-PGL-I serology and absence of a BCG scar can identify individuals with greater chances of developing leprosy neuropathy, who should be referred for US examination, reinforcing the importance of including serological and imaging methods in the epidemiological surveillance of leprosy HC.

Leprosy in an Adopted Woman Diagnosed by Molecular Tools: A Case Report from a Non-Endemic Area

Coupled with its rarity in non-endemic areas, the clinical heterogeneity of leprosy makes diagnosis very challenging. We report a diagnosis of multibacillary leprosy in a 22-year-old Indian woman, adopted at the age of 10 and living in Italy. The patient presented with painful skin lesions on the face, trunk, and lower and upper extremities, associated with dysesthesia and a motor deficit in her left leg following corticosteroid therapy interruption. Histopathology results from the skin lesions suggested leprosy, but no acid-fast bacilli were identified. Molecular biology in a center specializing in tropical diseases confirmed the diagnosis, allowing prompt and adequate treatment. Genotype analysis allowed the identification of a genotype 1D of M. leprae, facilitating the epidemiological investigation of the plausible infection origin. No resistances to rifampicin, dapsone, or ofloxacin were detected. Leprosy will continue to exist in high-income nations, and the incidence may rise over time due to increasing migration and globalization. CARE guidelines were followed.

Pathogenicity and virulence of Mycobacterium leprae

Leprosy is caused by Mycobacterium leprae (M. leprae) and M. lepromatosis, an obligate intracellular organism, and over 200,000 new cases occur every year. M. leprae parasitizes histiocytes (skin macrophages) and Schwann cells in the peripheral nerves. Although leprosy can be treated by multidrug therapy, some patients relapse or have a prolonged clinical course and/or experience leprosy reaction. These varying outcomes depend on host factors such as immune responses against bacterial components that determine a range of symptoms. To understand these host responses, knowledge of the mechanisms by which M. leprae parasitizes host cells is important. This article describes the characteristics of leprosy through bacteriology, genetics, epidemiology, immunology, animal models, routes of infection, and clinical findings. It also discusses recent diagnostic methods, treatment, and measures according to the World Health Organization (WHO), including prevention. Recently, the antibacterial activities of anti-hyperlipidaemia agents against other pathogens, such as M. tuberculosis and Staphylococcus aureus have been investigated. Our laboratory has been focused on the metabolism of lipids which constitute the cell wall of M. leprae. Our findings may be useful for the development of future treatments.

Intraneural ganglion cyst of the ulnar nerve causing cubital tunnel syndrome masquerading a peripheral nerve abscess of a neuritic leprosy

Cubital tunnel syndrome is a common entrapment neuropathy affecting the ulnar nerve. Intraneural ganglion cyst and nerve abscess due to leprosy can cause cubital tunnel syndrome. In this article, we are presenting a case of cubital tunnel syndrome caused due to an intraneural ganglion cyst in a 48-year-old lady. It had produced some diagnostic confusion due to its clinical similarity with nerve abscess. This is the first report of a case of an intraneural ganglion cyst of the ulnar nerve masquerading the diagnosis of a nerve abscess.

Mononeuritis Multiplex as Initial Manifestation of Pure Neuritic Leprosy-A Forgotten Cause: Clinical, Electrodiagnostic and Pathologic Correlations

Despite being common, polyneuropathy remains a diagnostic challenge for most clinicians. Mononeuritis multiplex (MM) refers to involvement of several or many peripheral nerves at the same or different points in time by a disease process. This report describes a case of an atypical presentation of Hansen's disease (HD) as mononeuritis multiplex in the left lower limb with corresponding radiographic, electrodiagnostic, and histopathological data that confirmed pure neuritic leprosy (PNL). We reiterate that although the incidence of PNL is exceedingly low characterized by nerve involvement without the characteristic cutaneous stigmata, leprosy is still the commonest cause of MM in the Indian sub-continent.This report underscores the crucial need for a heightened multi-disciplinary awareness of this "forgotten and uncommon" presentation of PNL. It is imperative that the treating physician should also understand the various neurological presentations, both mimics and chameleons, of this treatable disease to prevent permanent neuropathic injury and disability.

Rare occurrence of lepra type 1 reaction in pure neuritic leprosy: A case report

Type 1 reaction in pure neuritic leprosy usually occurs in the form of neuritis. The development of new skin lesion during reaction is rare. Clinicians should be aware about occurrence of type 1 reaction in pure neuritic leprosy.

A Clinicohistopathological Correlation of Hansen's Disease in a Rural Tertiary Care Hospital of Central India

Background

Leprosy is an ancient, chronic granulomatous infectious disease caused by Mycobacterium leprae, principally affecting the skin and peripheral nerves. The clinical manifestations of leprosy are variable and can mimic a variety of other skin diseases. Thus, histopathological examination plays an important role in early diagnosis and management.

Aim

The aim was to study the clinicohistopathological correlation of all suspected cases of Hansen's disease.

Materials and Methods

A retrospective study was conducted on 207 skin biopsies obtained from patients clinically diagnosed as new lesion of leprosy in the department of pathology from 2016 to 2019. Demographic, clinical details of the patients were retrieved from hospital information system. Hematoxylin-eosin- and Fite-Faraco-stained sections were evaluated for features confirming leprosy and further categorized as per Ridley-Jopling system. Sensitivity, specificity, and concordance rates were studied.

Results

The male-to-female ratio was 1.5:1. The agreement between histopathological and clinical diagnoses was more than 90% in all the subclasses except for borderline tuberculoid leprosy (BT) and tuberculoid leprosy (TT) which showed an agreement of 86.5% and 88.4%, respectively. The sensitivity of clinical diagnosis ranged from 69.70% for indeterminate to 100% for histoid and neuritic types. The specificity ranged from 90% for BT and TT to 100% for neuritic leprosy.

Conclusion

Clinical diagnosis of early leprosy lesions offers difficulties even to experienced dermatologists as a patient presents in different clinicopathological forms, depending on host immune status. Thus, the correlation between clinical, histopathological, and bacteriological features is required for diagnosis and classification of leprosy. Nerve damage is irreversible; therefore, early detection and treatment is important to prevent Grade 2 disabilities.

Evidence for Mycobacterium leprae Drug Resistance in a Large Cohort of Leprous Neuropathy Patients from India

Resistance to anti-leprosy drugs is on the rise. Several studies have documented resistance to rifampicin, dapsone, and ofloxacin in patients with leprosy. We looked for point mutations within the folP1, rpoB, and gyrA gene regions of the Mycobacterium leprae genome predominantly in the neural form of leprosy. DNA samples from 77 nerve tissue samples were polymerase chain reaction (PCR)-amplified for M leprae DNA and sequenced for drug resistance-determining regions of genes rpoB, folP1, and gyrA. The mean age at presentation and onset was 38.2 ± 13.4 (range 14-71) years and 34.9 ± 12.6 years (range 10-63) years, respectively. The majority had borderline tuberculoid leprosy (53 [68.8%]). Mutations associated with resistance were identified in 6/77 (7.8%) specimens. Mutations seen were those associated with resistance to rifampicin, ofloxacin, and dapsone. All the six patients were drug-naive. The clinical and pathological manifestations in this group did not differ from the drug-sensitive group. This study highlights the occurrence of resistance to the standard multidrug therapy and ofloxacin in leprosy. Among the entire cohort, 1/77 (1.3%) showed resistance to rifampicin, 2/77 (2.6%) to dapsone, and 5/77 (6.4%) to ofloxacin. Six new patients showing infection by mutant strains indicated the emergence of primary resistance. Resistance to ofloxacin could be due to frequent use of quinolones for many bacterial infections. The results of the study indicate the need for development of a robust and strict surveillance system for detecting drug resistance in leprosy in India.

Pathological, ultrasonographic, and electrophysiological characterization of clinically diagnosed cases of pure neuritic leprosy

A subset of neuritic form of leprosy, called pure neuritic leprosy (PNL), seen in a minority of leprosy patients, is characterized by peripheral neuropathy without skin lesions and an absence of acid-fast bacilli on skin smears. Patients with PNL are often started on drug therapy without confirmation of diagnosis. We, therefore, did a prospective study of clinically diagnosed PNL patients with correlation of ultrasonographic and biopsy findings. A total of 100 consecutive patients with PNL, diagnosed according to the consensus case definition, were included in the study. All patients underwent nerve conduction study, peripheral nerve ultrasonography, and sural nerve biopsy. Multiple mononeuropathies were present in 75% of cases, mononeuropathy in 18%, and polyneuropathy in the remaining 7%. Compared to clinical examination, ultrasonographic assessment of the peripheral nerves was not only better at the detection of thickening but also helped in characterization of their fascicular architecture, echogenicity, and vascularity. A total of 32 cases were confirmed on nerve biopsy, out of which 75% had demonstrable lepra bacilli. Cranial nerve involvement, presence of trophic ulcers, and bilateral thickening of the great auricular nerve were significantly associated with the positivity of lepra bacilli. A significant improvement in the disability score happened after multidrug therapy. A comprehensive electrophysiologic, ultrasonographic, and histological evaluation may be helpful in establishing a diagnosis of PNL with greater confidence, while ruling out other non-leprosy diagnoses.

Integrated approach in the control and management of skin neglected tropical diseases in three health districts of Côte d'Ivoire

BACKGROUND

Neglected tropical diseases (NTDs) comprise 20 communicable diseases that are prevalent in rural poor and remote communities with less access to the health system. For effective and efficient control, the WHO recommends that affected countries implement integrated control interventions that take into account the different co-endemic NTDs in the same community. However, implementing these integrated interventions involving several diseases with different etiologies, requiring different control approaches and driven by different vertical programs, remains a challenge. We report here the results and lessons learned from a pilot test of this integrated approach based on integrated screening of skin diseases in three co-endemic health districts of Côte d'Ivoire, a West African country endemic for Buruli ulcer, leprosy and yaw.

METHOD

This cross-sectional study took place from April 2016 to March 2017 in 3 districts of Côte d'Ivoire co-endemic for BU, leprosy and yaws. The study was carried out in 6 stages: identification of potentially co-endemic communities; stakeholder training; social mobilization; mobile medical consultations; case detection and management; and a review meeting.

RESULTS

We included in the study all patients with skin signs and symptoms at the screening stage who voluntarily accepted screening. In total, 2310 persons screened had skin lesions at the screening stage. Among them, 07 cases were diagnosed with Buruli ulcer. There were 30 leprosy cases and 15 yaws detected. Other types of ulcerations and skin conditions have been identified and represent the majority of cases detected. We learned from this pilot experience that integration can be successfully implemented in co-endemic communities in Côte d'Ivoire. Health workers are motivated and available to implement integrated interventions instead of interventions focused on a single disease. However, it is essential to provide capacity building, a minimum of drugs and consumables for the care of the patients identified, as well as follow-up of identified patients, including those with other skin conditions.

CONCLUSIONS

The results of this study show that the integration of activities can be successfully implemented in co-endemic communities under the condition of staff capacity building and minimal care of identified patients.

Appropriately Selected Nerve in Suspected Leprous Neuropathy Yields High Positive Results for Mycobacterium leprae DNA by Polymerase Chain Reaction Method

Identification of Mycobacterium leprae DNA by polymerase chain reaction (PCR) is a reliable and an affordable method to confirm leprosy. DNA from 87 nerve samples (61 from paraffin blocks and 26 fresh samples) was extracted. Mycobacterium leprae DNA was amplified by PCR from 80/87 (92%) specimens. Patients were seen over a period of 11 years (2007-2019), and leprosy was diagnosed based on clinical and characteristic histopathology findings. The clinical diagnostic possibilities were as follows: leprous neuropathy in 73/80 (91.3%), mononeuritis multiplex of unknown etiology in four (5.0%), vasculitic neuropathy in two (2.5%), and distal symmetric sensory motor neuropathy in one (1.3%). The biopsied nerves were as follows: superficial radial = 34 (42.6%), dorsal cutaneous branch of ulnar = 19 (23.8%), sural = 18 (22.5%), and superficial peroneal = 9 (11.3%), and corresponding neurological deficits were recorded in 77 (96.3%) cases. The histopathological diagnoses in total group were as follows: (borderline tuberculoid (BT) = 52, tuberculoid (TT) = 8, borderline lepromatous (BL) = 8, borderline borderline (BB) = 3, nonspecific inflammation = 3, healed/fibrosed = 4, and axonopathy = 2). Acid fast bacilli (AFB) was demonstrated in 11 (13.7%) samples. For comparison, 31 clinically and histopathologically defined non-leprous disease control nerves (inherited neuropathy = 20, vasculitis = 8, and nutritional neuropathy = 3) subjected to PCR were negative for M. leprae DNA. In most instances, there are multiple thickened peripheral nerves in suspected cases of leprosy, but neurological deficits pertaining to the thickened nerve are not as widespread. The current findings emphasize the importance of selecting the most appropriate nerve for biopsy to obtain a positive PCR result. We infer that clinical, histopathological, and PCR tests complement each other to help achieve a definitive diagnosis of leprosy particularly in pure neuritic leprosy and in leprous neuropathy with negative skin smears/biopsy.

A 10-year Retrospective Descriptive Study on Pure Neuritic Leprosy from a Tertiary Referral Centre

CONTEXT

Pure neuritic leprosy is a risk factor for grade 2 disability owing to the early nerve damage.

AIMS

To study the clinical patterns of neuritic leprosy, to determine the percentage of patients manifesting grade 2 disability at the time of diagnosis and to identify any risk factors for the same.

SETTINGS AND DESIGN

Retrospective descriptive study from previous case records of pure neuritic leprosy patients who attended a tertiary centre from 1st July 2007 to 30th June 2017.

SUBJECTS AND METHODS

Data on patients who satisfied the World Health Organization (WHO) cardinal criteria for diagnosis of leprosy, who had no skin lesion of leprosy and had acid-fast bacilli negative status on skin smears were collected using a pre-set proforma.

STATISTICAL ANALYSIS USED

The Chi-square test was used to assess statistical significance and logistic regression model was applied to avoid the effects of confounding factors.

RESULTS

A diagnostic delay of >1 year was observed in 44% patients. At the time of diagnosis, grade 2 disability was documented in 60 (80%) of patients. No statistically significant risk factor was identified for grade 2 disability.

LIMITATIONS

Retrospective nature and the study conducted in a tertiary care centre not reflecting the status in the community were the limitations.

CONCLUSIONS

Grade 2 disability noted in 80% of patients points to the inherent nature of disease to cause early nerve damage. Diagnostic delay of >1 year documented in 44% of patients underscores the diagnostic challenges in the absence of skin lesions.

Coexistence of Nerve Enlargement and Neuratrophy Detected by Ultrasonography in Leprosy Patients

The purpose of this study was to evaluate peripheral neural impairment in leprosy patients by ultrasonography (US). The cross-sectional areas (CSAs) of the median (M), ulnar (U) and common fibular (CF) nerves were compared in 71 leprosy patients and 29 healthy controls, and the data were analyzed between the leprosy, multibacillary (MB)/paucibacillary (PB), reaction (R)/no reaction (NR), disability (D)/no disability (ND), and longer/shorter duration groups after treatment. We found that for the nerves located in upper limbs, the CSAs were significantly increased in the leprosy patients vs the controls; the PB group vs the MB group; the R group vs the NR group; the ND group vs the D group; and the longer duration group vs the shorter duration group at some positions of the M nerve and U nerve. In contrast, for the nerves located in lower limbs, the CSAs were significantly reduced in the leprosy patients vs the controls and in the longer duration group vs the shorter duration group at some positions of the CF nerve. This result indicated that nerve enlargement and neuratrophy coexist in leprosy patients.

Hansen's Neuritis Revisited - A Clinicopathological Study

INTRODUCTION

Leprosy affecting the nerve solely or with concomitant skin lesions is not an uncommon condition in clinical practice. It is responsible for extensive morbidity and often poses a diagnostic challenge. This study aims to highlight the clinicopathological features of Hansen's neuritis (HN).

MATERIALS AND METHODS

In this retrospective study, cases of histologically diagnosed HN, from January 2010 to July 2017, were reviewed in the light of clinical features, treatment history, and outcome.

RESULTS

There were 18 cases of HN which accounted for 3.97% of total nerve biopsy samples (n = 453) and 0.02% of total histopathology samples (n = 81,013). The male: female ratio was 5:1 in the cases of HN. Age range was 20-79 years with a mean age of 42.4 years (standard deviation: ±14.03). Among the HN cases, there were 13 cases of pure neuritic leprosy (61.1%). Mononeuritis multiplex was the most common finding in the nerve conduction study. Six (33.3%) cases exhibited histological features of borderline tuberculoid leprosy, followed by five (27.8%) cases of mid-borderline features, three (16.7%) cases each of borderline lepromatous and burnt-out HN, and one (5.6%) case of polar tuberculoid leprosy. Lepra bacilli were detected on Fite-Faraco stain in 44.4% cases.

CONCLUSION

Diagnosis of HN depends on astute search for skin lesions, nerve thickening or tenderness, sensory or motor symptoms, histopathological examination, and demonstration of lepra bacilli.

Nerve abscess in pure neural leprosy mistaken for peripheral nerve sheath tumour with disastrous consequence: what can we learn?

A 34-year-old Indian man presented to an orthopaedician with gradually progressive hypoesthesia affecting his right lower limb and an ipsilateral common peroneal nerve swelling around the knee. The nerve swelling was diagnosed as a peripheral nerve sheath tumour based on MRI findings and was excised, only to be revealed as leprous nerve abscess on histopathology later. The patient developed right foot drop as a result of common peroneal nerve biopsy. This case presents several learning points in the diagnosis of pure neural leprosy.

Revisiting primary neural leprosy: Clinical, serological, molecular, and neurophysiological aspects

BACKGROUND

Leprosy neuropathy is considered the most common peripheral neuropathy of infectious etiology worldwide, representing a public health problem. Clinical diagnosis of primary neural leprosy (PNL) is challenging, since no skin lesions are found and the slit skin smear bacilloscopy is negative. However, there are still controversial concepts regarding the primary-neural versus pure-neural leprosy definition, which will be explored by using multiple clinical-laboratory analyses in this study.

METHODOLOGY/PRINCIPAL FINDINGS

Seventy patients diagnosed with primary neural leprosy from 2014 to 2016 underwent clinical, laboratorial and neurophysiological evaluation. All patients presented an asymmetric neural impairment, with nerve thickening in 58.6%. Electroneuromyography showed a pattern of mononeuropathy in 51.4%. Positivity for ELISA anti-PGL1 was 52.9%, while the qPCR of slit skin smear was 78.6%. The qPCR of nerve biopsies was positive in 60.8%. Patients with multiple mononeuropathy patterns showed lower levels of anti-PGL-1 (p = 0.0006), and higher frequency of neural thickening (p = 0.0008) and sensory symptoms (p = 0.01) than those with mononeuropathy.

CONCLUSIONS/SIGNIFICANCE

PNL is not a synonym of pure neural leprosy, as this condition may include a generalized immune response and also a skin involvement, documented by molecular findings. Immunological, molecular, and neurophysiological tools must be implemented for diagnosing primary neural leprosy to achieve effective treatment and reduction of its resultant disabilities that still represent a public health problem in several developing nations. Finally, we propose a algorithm and recommendations for the diagnosis of primary neural leprosy based on the combination of the three clinical-laboratorial tools.

Extensive sonographic ulnar nerve enlargement above the medial epicondyle is a characteristic sign in Hansen's neuropathy

Objective

Earlier studies have shown sonographic enlargement of the ulnar nerve in patients with Hansen’s neuropathy. The present study was performed to determine whether sonography or electrophysiological studies can detect the specific site of ulnar nerve pathology in leprosy.

Methods

Eighteen patients (thirty arms) with Hansen’s disease and an ulnar neuropathy of whom 66% had borderline tuberculoid (BT), 27% lepromatous leprosy (LL) and 7% mid-borderline (BB) leprosy were included in the study. Cross-sectional area (CSA) of ulnar nerve was measured every two centimeters from wrist to medial epicondyle and from there to axilla. All patients underwent standard motor and sensory nerve conduction studies of the ulnar nerve. Thirty age and sex matched controls underwent similar ulnar nerve CSA measurements and conduction studies.

Results

Ulnar nerve was clinically palpable in 19 of the 30 arms of patients. Motor and sensory nerve conduction studies of the ulnar nerve showed a reduced compound motor action potential and sensory nerve action potential amplitude in all patients. Motor Conduction Velocity (MCV) in patients were slower in comparison to controls, especially at the elbow and upper arm, but unable to exactly locate the site of the lesion. In comparison to controls the ulnar nerveCSA was larger in the whole arm in patients and quite specific the maximum enlargement was seen between nulnar sulcus and axilla, peaking at four centimeters above the sulcus.

Conclusions

A unique sonographic pattern of nerve enlargement is noted in patients with ulnar neuropathy due to Hansen’s disease, while this was not the case for the technique used until now, the electrodiagnostic testing. The enlargement starts at ulnar sulcus and is maximum four centimeters above the medial epicondyle and starts reducing further along the tract. This characteristic finding can help especially in diagnosing pure neuritic type of Hansen’s disease, in which skin lesions are absent, and alsoto differentiate leprosy from other neuropathies in which nerve enlargement can occur.

Hansen’s neuropathy is caused by Mycobacterium leprae. The diagnosis of Hansen disease is based on typical skin lesions, nerve enlargement and presence of bacilli in the skin smear. One of the types of leprosy is a pure neuritic type which manifests without skin lesions. High resolution ultrasound is new modality by which the morphology of the peripheral nerves can be studied. Earlier studies have shown that peripheral nerves are thickened in Hansen’s disease and ultrasound is superior in identifying nerve enlargement when compared with clinical palpation. Good correlation exits between nerve enlargement and electrophysiological studies. The current research was to look for a specific pattern of nerve enlargement and we studied patients with Hansen’s ulnar neuropathy. We found an unique pattern of nerve enlargement in which the ulnar nerve enlargement starts at the sulcus and the enlargement is maximum four centimetres above the sulcus and then it tapers. This pattern of unique nerve enlargement can help especially in diagnosing pure neuritic type of Hansen’s disease, in which skin lesions are absent, and is also useful to differentiate leprosy from other neuropathies in which nerve enlargement can occur.

Evaluation of polymerase chain reaction in nerve biopsy specimens of patients with Hansen's disease

BACKGROUND

Pure neuritic variety of leprosy (PNL) presents as peripheral neuropathy with absent skin lesions and negative skin smears. Diagnosing PNL is an uphill task as most of these patients have nonspecific changes on nerve biopsy. In such circumstances, additional molecular diagnostic tools like polymerase chain reaction (PCR) has proven to be useful in diagnosing leprosy. The present study was planned to evaluate the role of PCR in nerve biopsy specimens of patients with PNL.

METHODS

Patients attending the neuromuscular clinic from January 2013 to June 2014 with mononeuropathy multiplex underwent detailed diagnostic evaluation to ascertain the cause of neuropathy. Patients where this evaluation failed to establish an etiology underwent a nerve biopsy.

RESULTS

Nerve biopsy was done in 52 patients, of which 35 were diagnosed as pure neuritic leprosy. Definite leprosy with positive wade fite staining for lepra bacilli was seen in 13 patients and 22 biopsies revealed a probable leprosy without lepra bacilli being identified. PCR for M. leprae was positive in 22 patients (62%). 12 of the 13 cases with definite leprosy on histopathology were PCR positive while in the AFB negative group, PCR was positive in 10 cases. PCR had a sensitivity of 92.3%, specificity of 54.5%. The positive and negative predictive value of PCR was 54.5% and 92.3% respectively.

CONCLUSIONS

PCR helps in diagnosing PNL in doubtful cases. A positive PCR increases the sensitivity of detection of M. leprae especially in cases of probable PNL group where AFB cannot be demonstrated on histopathology.

A unique case of concomitant intra and extracranial Hansen's disease

Leprosy is a debilitating disease that usually involves the peripheral branches of the cranial nerves leading to anesthetic/hypoesthetic skin lesions and thickened peripheral nerves. However, the involvement of the central nervous system (CNS) is extremely rare. To the best of the author's knowledge, the involvement of the cranial nerve nuclei by leprosy has not been reported in the literature and the present case is the first report of involvement of the facial nerve nuclei by leprosy.

Diffusion Tensor Imaging Tractography in Pure Neuritic Leprosy: First Experience Report and Review of the Literature

Five years after both right ulnar and median nerve decompression for paraesthesias and palsy, a patient, coming from Nigeria but living in Italy, came to our unit claiming to have persistent pain and combined median and ulnar palsy. Under suspicion of leprosy, skin and left sural nerve biopsy were performed. Skin tests were negative, but Schwann cells resulted as positive for acid-fast bacilli (AFB), leading to the diagnosis of Pure Neuritic Leprosy (PNL). The patient was given PB multidrug therapy and recovered from pain in two months. After nine months both High Resolution Ultrasonography (HRUS) and Magnetic Resonance Imaging (MRI) were performed, revealing thickening of the nerves. Since demyelination is common in PNL, the Authors started to use Diffusion Tensor Imaging Tractography (DTIT) to get better morphological and functional data about myelination than does the traditional imaging. DTIT proved successful in showing myelin discontinuity, reorganization, and myelination, and the Authors suggest that it can give more information about the evolution of the disease, as well as further indications for surgery (nerve decompression, nerve transfers, and babysitting for distal effector protection), and should be added to traditional imaging tools in leprosy.