Mandating nerve biopsy: A step towards personalizing therapy in pure neuritic leprosy

Silent peripheral neuropathy determined by high-resolution ultrasound among contacts of patients with Hansen's disease

Introduction

Hansen's disease (HD) primarily infects peripheral nerves, with patients without HD being free of peripheral nerve damage. Household contacts (HHCs) of patients with HD are at a 5-10 times higher risk of HD than the general population. Neural thickening is one of the three cardinal signs that define a case of HD according to WHO guidelines, exclusively considering palpation examination that is subjective and may not detect the condition in the earliest cases even when performed by well-trained professionals. High-resolution ultrasound (HRUS) can evaluate most peripheral nerves, a validated technique with good reproducibility allowing detailed and accurate examination.

Objective

This study aimed to use the peripheral nerve HRUS test according to the HD protocol as a diagnostic method for neuropathy comparing HHCs with healthy volunteers (HVs) and patients with HD.

Methods

In municipalities from 14 different areas of Brazil we selected at random 83 HHC of MB-patients to be submitted to peripheral nerve ultrasound and compared to 49 HVs and 176 HD-patients.

Results

Household contacts assessed by HRUS showed higher median and mean absolute peripheral nerve cross-sectional area (CSA) values and greater asymmetries (ΔCSA) compared to HVs at the same points. Median and mean absolute peripheral nerve CSA values were higher in patients with HD compared to HCCs at almost all points, while ΔCSA values were equal at all points. Mean ± SD focality (ΔTpT) values for HHCs and patients with HD, respectively, were 2.7 ± 2.2/2.6 ± 2.2 for the median nerve, 2.9 ± 2.7/3.3 ± 2.9 for the common fibular nerve (p > 0.05), and 1.3 ± 1.3/2.2 ± 3.9 for the ulnar nerve (p < 0.0001).

Discussion

Considering HRUS findings for HHCs, asymmetric multiple mononeuropathy signs (thickening or asymmetry) in at least 20% of the nerves evaluated could already indicates evidence of HD neuropathy. Thus, if more nerve points are assessed in HHCs (14 instead of 10), the contacts become more like patients with HD according to nerve thickening determined by HRUS, which should be a cutting-edge tool for an early diagnosis of leprosy cases.

Central nervous system, spinal root ganglion and brachial plexus involvement in leprosy: A prospective study

Background

Leprosy is primarily a disease of peripheral nerves. Some isolated case reports and case series have communicated imaging changes in the central nervous system (CNS) and brachial plexus in patients with leprosy.

Objectives

To study the neuroimaging abnormalities in patients with lepra bacilli-positive neuropathy in the context of CNS, spinal root ganglion, and brachial plexus.

Design

Prospective observational study

Methods

We screened newly-diagnosed patients with multibacillary leprosy presenting with neuropathy. Patients with bacilli-positive sural nerve biopsies were included in the study and subjected to magnetic resonance imaging (MRI) of the brain and spinal cord.

Results

A total of 54 patients with bacteriologically confirmed multibacillary leprosy were screened; Mycobacterium leprae was demonstrated in the sural nerve biopsies of 29 patients. Five patients (5/29; 17.24%) had MRI abnormalities in CNS, spinal root ganglion, and/or brachial plexus. Three patients had MRI changes suggestive of either myelitis or ganglionitis. One patient had T2/FLAIR hyperintensity in the middle cerebellar peduncle while 1 had T2/FLAIR hyperintensity in the brachial plexus.

Conclusion

CNS, spinal root ganglion, and brachial plexus are involved in patients with leprous neuropathy. Immunological reaction against M leprae antigen might be a plausible pathogenetic mechanism for brachial plexus and CNS imaging abnormalities.

Primary neural leprosy: clinical, neurophysiological and pathological presentation and progression

Disability in leprosy is a direct consequence of damage to the peripheral nervous system which is usually worse in patients with no skin manifestations, an underdiagnosed subtype of leprosy known as primary neural leprosy. We evaluated clinical, neurophysiological and laboratory findings of 164 patients with definite and probable primary neural leprosy diagnoses. To better understand the disease progression and to improve primary neural leprosy clinical recognition we compared the characteristics of patients with short (≤ 12 months) and long (> 12 months) disease duration. Positive and negative symptoms mediated by small-fibre were frequent at presentation (∼95%), and symptoms tend to manifest first in the upper limbs (∼68%). There is a consistent phenotypic variability between the aforementioned groups. Deep sensory modalities were spared in patients evaluated within the first 12 months of the disease, and were only affected in patients with longer disease duration (∼12%). Deep tendon reflexes abnormalities were most frequent in patients with longer disease duration (p < 0,001), as well as motor deficits (p = 0,002). Damage to large fibres (sensory and motor) is a latter event in primary neural leprosy. Grade-2 disability and nerve thickening was also more frequent in cases with long disease duration (p < 0,001). Primary neural leprosy progress over time and there is a marked difference in clinical phenotype between patients with short and long disease duration. Patients assessed within the first 12 months of symptom onset had a non-length-dependent predominant small-fibre sensory neuropathy, whilst patients with chronic disease presented an asymmetrical all diameter sensory-motor neuropathy and patchily decreased/absent deep tendon reflexes.

Pure neural leprosy or amyloid neuropathy? Systematic review and clinical case report

OBJECTIVE

To review the literature and to report a clinical case with initial suspicion of pure neural leprosy and final diagnosis of amyloid neuropathy.

METHODS

The study was conducted in two stages. In stage one, a systematic literature review was carried out, with searches performed in the PubMed, Medline, and Lilacs databases, as well as in the leprosy sectoral library of the Virtual Health Library, using the following descriptors: neuritic leprosy, pure neural leprosy, primary neural leprosy, pure neuritic leprosy, amyloid polyneuropathy, amyloid neuropathies, and amyloid polyneuropathy. The search was carried out on May 28, 2020. Clinical trials, cohort studies, cross-sectional studies, clinical cases, and case studies published in Portuguese, English or Spanish between 2010 and 2020 were included. Stage two reports a case with initial suspicion of pure neural leprosy. Laboratory tests, electroneuromyography, ultrasound, and biopsy of the sural nerve were requested.

RESULTS

Twenty-three scientific texts were included. No publications were found that contained both topics together. The challenging diagnosis of pure neural leprosy and the possibility of using auxiliary resources in diagnosis were the most emphasized themes in the studies. In the clinical case, the patient's electroneuromyography showed sensitive and motor polyneuropathy of the lower limbs, which was predominantly sensory and axonal, symmetrical, of moderate intensity, and the mixed type (axonal-demyelinating). Ultrasonography of the sural nerve revealed changes in the contour of the deep fibular nerves; biopsy of the sural nerve showed an accumulation of amorphous eosinophilic material in the nerve path, and Congo red stain showed apple-green birefringence of the deposit under polarized light. The final diagnosis was amyloid neuropathy.

CONCLUSIONS

The final clinical diagnosis was amyloid neuropathy. The diagnosis of pure neural leprosy in endemic areas in Brasil is still a challenge for the health system.

Neuropathies of leprosy

Neuropathies form an integral part of the symptomatology of leprosy. Neuropathies of leprosy take various forms and shapes. At one end is the cutaneous nerve involvement adjacent to the anaesthetic skin patch and the other is of symmetrical pansensory neuropathy and the devastating sensory ataxia of leprous ganglionits. Lepra reactions add to the spectrum. Hosts immunological status largely decides the clinical manifestations seen in nerves and skin. A wide array of diagnostic techniques like ultrasonography, magnetic resonance neurography, serological markers, molecular tests, skin biopsy and in selected cases, the nerve biopsy with special stains and electron microscopy are obtainable to help the clinical diagnosis. The unsuspecting clinician, lack of community awareness and limited availability of diagnostic tests are important adverse factors in the total outcome. Multi drug therapy is efficacious and corticosteroids reduce the impact of nerve damage in leprosy. The efficacy, dose and duration of corticosteroid therapy are presently inexact and other immune suppressants like azathioprine are being evaluated. Chronic disabilities and residual deficits require attention of multiple specialties. In the coming time, focus on prevention could lead to favourable results. This review will discuss the classification systems, common and uncommon clinical features, diagnostic armamentarium and therapeutic and preventive aspects of neuropathies of leprosy.

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.