Role of ulnar nerve sonography in leprosy neuropathy with electrophysiologic correlation

Role of multisegmental nerve ultrasound in the diagnosis of leprosy neuropathy

INTRODUCTION/AIMS

Leprosy is the most common treatable peripheral neuropathy worldwide. The detection of peripheral nerve impairment is essential for its diagnosis and treatment, in order to prevent stigmatizing deformities and disabilities. This study was performed to identify neural thickening through multisegmental ultrasound (US).

METHODS

We assessed US measurements of cross-sectional areas (CSAs) of ulnar, median and tibial nerves at two points (in the osteofibrous tunnel and proximal to the tunnel), and also of the common fibular nerve at the fibular head level in 53 leprosy patients (LP), and compared with those of 53 healthy volunteers (HV), as well as among different clinical forms of leprosy.

RESULTS

US evaluation detected neural thickening in 71.1% (38/53) of LP and a mean number of 3.6 enlarged nerves per patient. The ulnar and tibial were the most frequently affected nerves. All nerves showed significantly higher measurements in LP compared with HV, and also greater asymmetry, with significantly higher values for ulnar and tibial nerves. We found significant CSAs differences between tunnel and pre-tunnel points for ulnar and tibial nerves, with maximum values proximal to the tunnel. All clinical forms of leprosy evaluated showed neural enlargement through US.

DISCUSSION

Our findings support the role of multisegmental US as a useful method for diagnosing leprosy neuropathy, revealing that asymmetry, regional and non-uniform thickening are characteristics of the disease. Furthermore, we observed that neural involvement is common in different clinical forms of leprosy, reinforcing the importance of including US evaluation of peripheral nerves in the investigation of all leprosy patients.

Neuromuscular Ultrasound in Polyneuropathies

Neuromuscular ultrasound is a painless, radiation-free, high-resolution imaging technique for assessing the peripheral nervous system. It can accurately depict changes in the nerves and muscles of individuals with neuromuscular conditions, and it is therefore a robust diagnostic tool for the assessment of individuals with polyneuropathies. This review will outline the typical ultrasonographic changes found in a wide variety of polyneuropathies. In general, demyelinating conditions result in greater nerve enlargement than axonal conditions, and acquired conditions result in more patchy nerve enlargement compared to diffuse nerve enlargement in hereditary conditions. This review is data-driven, but more nuanced anecdotal findings are also described. The overall goal of this paper is to provide clinicians with an accessible review of the ultrasonographic approaches and findings in a wide variety of polyneuropathies.

A case report on imaging findings of rare segmental necrotizing granulomatous neuritis of leprosy involving ulnar nerve

Introduction

Segmental necrotizing granulomatous neuritis (SNGN) is a rare complication of leprosy involving peripheral nerves. It can appear alone in cases of pure neuritic leprosy or in combination with cutaneous lesions.

Case Presentation

A 15-year-old female diagnosed with borderline tuberculoid leprosy who received prior multidrug therapy presented 2 years later with occasional pain and tingling sensations along the inner aspect of her right arm and forearm. Imaging findings suggested SNGN, which was corroborated by cytopathological examination. She was considered relapsed from leprosy, and multi-drug therapy and steroids were started, following which she reported a decrease in the size of the swelling along with no further deterioration of the sensorineural deficit.

Discussion

SNGN, which is one of the rare complications of leprosy, can create diagnostic dilemmas as its differential diagnoses include reversal reactions, and peripheral nerve tumors (such as schwannoma and neurofibroma), which have been outlined in this article. SNGN is more likely when magnetic resonance imaging (MRI) shows a well-defined ovoid lesion with central necrosis and peripheral rim enhancement.

Conclusion

The incidence of SNGN is on the rise due to multi-drug therapy. In our case, the patient developed SNGN, which was considered a relapse from leprosy, and multi-drug therapy and steroids were started, following which the patient reported a significant reduction in the size of the swelling with no further deterioration of the sensorineural deficit. Hence, an appropriate diagnosis of SNGN through ultrasonography and MRI will lead to favorable outcomes, ultimately benefiting the patient.

A case report on imaging findings of rare segmental necrotizing granulomatous neuritis of leprosy involving ulnar nerve

Introduction

Segmental necrotizing granulomatous neuritis (SNGN) is a rare complication of leprosy involving peripheral nerves. It can appear alone in cases of pure neuritic leprosy or in combination with cutaneous lesions.

Case Presentation

A 15-year-old female diagnosed with borderline tuberculoid leprosy who received prior multidrug therapy presented 2 years later with occasional pain and tingling sensations along the inner aspect of her right arm and forearm. Imaging findings suggested SNGN, which was corroborated by cytopathological examination. She was considered relapsed from leprosy, and multi-drug therapy and steroids were started, following which she reported a decrease in the size of the swelling along with no further deterioration of the sensorineural deficit.

Discussion

SNGN, which is one of the rare complications of leprosy, can create diagnostic dilemmas as its differential diagnoses include reversal reactions, and peripheral nerve tumors (such as schwannoma and neurofibroma), which have been outlined in this article. SNGN is more likely when magnetic resonance imaging (MRI) shows a well-defined ovoid lesion with central necrosis and peripheral rim enhancement.

Conclusion

The incidence of SNGN is on the rise due to multi-drug therapy. In our case, the patient developed SNGN, which was considered a relapse from leprosy, and multi-drug therapy and steroids were started, following which the patient reported a significant reduction in the size of the swelling with no further deterioration of the sensorineural deficit. Hence, an appropriate diagnosis of SNGN through ultrasonography and MRI will lead to favorable outcomes, ultimately benefiting the patient.

The role of imaging in focal neuropathies

Electrodiagnostic testing (EDX) has been the diagnostic tool of choice in peripheral nerve disease for many years, but in recent years, peripheral nerve imaging has been used ever more frequently in daily clinical practice. Nerve ultrasound and magnetic resonance (MR) neurography are able to visualize nerve structures reliably. These techniques can aid in localizing nerve pathology and can reveal significant anatomical abnormalities underlying nerve pathology that may have been otherwise undetected by EDX. As such, nerve ultrasound and MR neurography can significantly improve diagnostic accuracy and can have a significant effect on treatment strategy. In this chapter, the basic principles and recent developments of these techniques will be discussed, as well as their potential application in several types of peripheral nerve disease, such as carpal tunnel syndrome (CTS), ulnar neuropathy at the elbow (UNE), radial neuropathy, brachial and lumbosacral plexopathy, neuralgic amyotrophy (NA), fibular, tibial, sciatic, femoral neuropathy, meralgia paresthetica, peripheral nerve trauma, tumors, and inflammatory neuropathies.

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.

Ulnar nerve thickness at the elbow on longitudinal ultrasound view in control subjects

INTRODUCTION

Ulnar mononeuropathy at the elbow is the second most frequent neuropathy in humans. Diagnosis is based on clinical and electrophysiological criteria and, more recently, also on ultrasound. Cross-sectional ultrasound is currently the most valued, although longitudinal ultrasound allows assessment of the entire affected trajectory of the nerve in a single view, but always in a straight line with no changes in direction, as in the extended elbow. The main aim of this work is to propose normative values ​​for longitudinal ultrasound of the ulnar nerve at the elbow.

METHODS

The neurological exploration of upper extremity, and electrophysiological and ultrasound parameters at the elbow of ulnar nerve were evaluated in 76 limbs from 38 asymptomatic subjects.

RESULTS

The diameters of the nerve as well as the distal and proximal areas were larger at the proximal region of the ulnar groove, and even more so in older individuals. In most of these elderly subjects, we found a small, non-significant slowdown in motor conduction velocity at the elbow with respect to the forearm (less than 5 m/s).

CONCLUSIONS

We observed a good correlation between the longitudinal and cross-sectional ultrasounds of the ulnar nerve at the elbow. Longitudinal ultrasound proved to be sensitive, reliable, simple and rapid, but its greatest contribution was allowing the visualization of the entire nerve trajectory in an integrated way, providing an image with good definition of the outline, proportions and intraneural characteristics of the nerve.

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.

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].

Review Article "Spotlight on Ultrasonography in the Diagnosis of Peripheral Nerve Disease: The Evidence to Date"

Neuromuscular ultrasound is rapidly becoming incorporated into clinical practice as a standard tool in the assessment of peripheral nerve diseases. Ultrasound complements clinical phenotyping and electrodiagnostic evaluation, providing critical structural anatomical information to enhance diagnosis and identify structural pathology. This review article examines the evidence supporting neuromuscular ultrasound in the diagnosis of compressive mononeuropathies, traumatic nerve injury, generalised peripheral neuropathy and motor neuron disease. Extending the sonographic evaluation of nerves beyond simple morphological measurements has the potential to improve diagnostics in peripheral neuropathy, as well as advancing the understanding of pathological mechanisms, which in turn will promote precise therapies and improve therapeutic outcomes.

Sonographic pattern of median nerve enlargement in Hansen's neuropathy

OBJECTIVES

Median nerve enlargement in leprosy seems to be more proximal than in carpal tunnel syndrome (CTS), but this feature has not been studied systematically. The aim of the study was to compare the sites of median nerve enlargement in patients with leprosy with that of patients with CTS.

MATERIALS AND METHODS

Transverse sections of the median nerve were recorded from wrist to the mid-forearm (at distal wrist crease and at 2-cm: M1, 4-cm: M2, 6-cm: M3, 8-cm: M4 and 10-cm: M5, proximal to the distal wrist crease in the forearm) in patients with leprosy, CTS and healthy subjects using high-resolution ultrasound.

RESULTS

Twenty-six patients each with leprosy and CTS were compared with healthy controls. Patients with leprosy included 6 (23.1%), 7 (26.9%), 7 (26.9%) and 6 (23.1%) patients with borderline tuberculoid, borderline-borderline, borderline lepromatous and lepromatous leprosy, respectively. Cross-sectional area (CSA) of median nerve was increased in all patients with leprosy as compared to healthy controls at all points of measurement. CSA was higher among patients with leprosy as compared to CTS at all points except at the wrist. In patients with leprosy, the maximal enlargement was noted 2-cm (M1) proximal to the wrist crease with gradual tapering of the CSA proximally (p < .05). In contrast, in patients with CTS the median nerve was maximally enlarged at the distal wrist crease (p<.05).

CONCLUSIONS

Median nerve enlargement 2-cm proximal to the distal wrist crease distinguishes leprosy from CTS. This important discriminating sign can be used at point-of-care to identify patients with leprosy.

High-resolution ultrasound in the assessment of peripheral nerves in leprosy: A comparative cross-sectional study

BACKGROUND

Detection of peripheral nerve thickening and nerve function impairment is crucial in the diagnosis and the management of leprosy.

AIMS AND OBJECTIVES

(1) To document the cross-sectional area, echotexture and blood flow of peripheral nerves in healthy controls and leprosy cases using high-resolution ultrasound, (2) to compare the sensitivities of clinical examination and high-resolution ultrasound in detecting peripheral nerve thickening in leprosy.

METHODS

Peripheral nerves of 30 leprosy patients and 30 age- and sex-matched controls were evaluated clinically and by high-resolution ultrasound. When the cross-sectional area of a peripheral nerve on high-resolution ultrasound in a leprosy patient was more than the calculated upper bound of the 95% confidence interval for mean for that specific nerve in controls, that particular peripheral nerve was considered to be enlarged.

RESULTS

Cross-sectional areas more than 7.1 mm2 for the radial nerve, 8.17 mm2 for ulnar, 10.17 mm2 for median, 9.50 mm2 for lateral popliteal and 11.21mm2 for the posterior tibial nerve were considered as nerve thickening on high-resolution ultrasound. High-resolution ultrasound detected 141/300 (47%) nerves enlarged in contrast to the 60 (20%) diagnosed clinically by palpation (P < 0.001). Clinical examination identified thickening in 31/70 (44.3%) nerves in cases with impairment of nerve function and 29/230 (12.6%) in the absence of nerve function impairment. High-resolution ultrasound detected thickening in 50/70 (71.4%) nerves with impairment of function and in 91/230 (39.6%) nerves without any impairment of function.

LIMITATION

A single-centre study design was the major study limitation.

CONCLUSION

High-resolution ultrasound showed greater sensitivity than clinical examination in detecting peripheral nerve thickening in leprosy cases. High-resolution ultrasound, may therefore improve the sensitivity of the diagnostic criterion of peripheral nerve enlargement in the diagnosis and classification 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.

Ultrasound Measurements and Assessments of the Ulnar Nerve at the Elbow and Cubital Tunnel: A Scoping Review

Ulnar neuropathy at the elbow (UNE) is the second most frequent peripheral nerve entrapment neuropathy in the upper extremity. The diagnosis is determined through a combination of history, physical examination, and electrodiagnostic testing. However, the use of high-resolution sonography is increasing, with sonographic measurements of ulnar nerve dimension established as a reliable diagnostic criterion for UNE. Sonographic imaging can describe anatomical features beyond ulnar nerve size, and therefore additional observations could potentially be used in UNE diagnosis and treatment follow-up. This review was a scoping of the literature on different sonographic measurements and assessments that have been reported to evaluate the ulnar nerve and cubital tunnel. This should provide a guide to scanning protocols for sonographers.

Diagnostic accuracy of tests for leprosy: a systematic review and meta-analysis

OBJECTIVES

Owing to difficulties in the clinical diagnosis of leprosy, several complementary tests have been developed and used. The aim was to systematically summarize the accuracy of diagnostic tests for leprosy.

METHODS

We searched for relevant articles in Embase, Medline, and Global Health databases, until June 2017. Studies evaluating the accuracy of any diagnostic techniques for differentiating between people with and without leprosy were included. Studies solely focusing on differentiating between the separate forms of leprosy were excluded. Our protocol was registered on PROSPERO (CRD42017071803). We assessed study quality using the QUADAS-2 checklist. A bivariate random effects regression model was used for the meta-analyses.

RESULTS

We included 78 studies, most of those evaluating the detection of IgM antibodies against phenolic glycolipid I using ELISA. Sensitivity of the 39 studies evaluating ELISA was 63.8% (95% CI 55.0-71.8); specificity 91.0% (95% CI 86.9-93.9). The lateral flow test (nine studies) and the agglutination test (five studies) had a slightly higher sensitivity and a slightly lower specificity. Sensitivity of qPCR was (five studies) 78.5% (95% CI 61.9-89.2) and specificity 89.3% (95% CI 61.4-97.8). Sensitivity of conventional PCR was (17 studies) 75.3% (95% CI 67.9-81.5) and specificity 94.5% (95% CI 91.4-96.5).

CONCLUSIONS

Although the test accuracy looks reasonable, the studies suffered from heterogeneity and low methodological quality.

Ulnar Neuropathy at the Elbow Associated With Focal Demyelination in the Proximal Forearm and Intraoperative Imaging Correlation

Ulnar nerve focal demyelination (FD) in the forearm [defined as conduction block (CB) and or temporal dispersion (TD)] has been described with immune-mediated neuropathy and with compression affecting the forearm segment of the nerve. The association of FD in the forearm with entrapment ulnar neuropathy at the elbow, as well as the intraoperative imaging of the abnormal ulnar nerve at the flexor carpi ulnaris muscle level (FCU), has not been reported before. We report a 33-years-old woman presented with only sensory symptoms of the right hand suggestive of right ulnar neuropathy for the last 10 years. On clinical examination, she had reduced pinprick sensation on the little and ring fingers with no motor deficit. Nerve-conduction study showed slowing of conduction velocity across the elbow on the right when recording at the abductor digiti minimi (ADM) and first dorsal interossei (FDI). There was 63% amplitude drop when stimulating below the elbow compared to distal stimulation at the wrist. Increment inching study localized the block at 5 cm distal to the medial epicondyle. During surgical transposition, the ulnar nerve was swollen, and edematous in the segment where the nerve enters the FCU muscle, which provides a physiological explanation for the electrophysiological findings. After the surgery, the patient reported complete resolution of the symptoms. This case demonstrate that ulnar nerve motor potential FD at the proximal forearm could be recorded and it is still compatible with ulnar-nerve entrapment at the elbow.

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.

Active Leprosy Neuritis Detected on FDG PET/CT

Uses of FDG PET/CT have been previously documented in multiple series in peripheral nerve pathologies, including neurolymphomatosis, peripheral nerve sheath tumor, and plexopathies. We present the case of a 24-year-old man with leprosy neuritis who underwent FDG PET/CT. We suggest that FDG PET/CT can be used as an adjunct tool to monitor neuritis in leprosy patients.

Nerve ultrasound in polyneuropathies

Ultrasound can be used to visualize pathology in the peripheral nerves of patients with polyneuropathy. Nerve enlargement is the most frequent pathology, but other abnormalities, including abnormal nerve echogenicity and vascularity, are also encountered. This monograph presents an overview of the role of nerve ultrasound in the evaluation and management of both inherited and acquired polyneuropathies. A description of the sonographic techniques and common abnormalities is provided, followed by a presentation of typical findings in different neuropathies. Scoring systems for characterizing the presence and pattern of nerve abnormalities as they relate to different polyneuropathies are presented. Muscle Nerve 57: 716-728, 2018.

Neuromuscular Ultrasound in the Assessment of Polyneuropathies and Motor Neuron Disease

Neuromuscular ultrasound is an emerging technology for the evaluation of conditions affecting nerve and muscle, with most of the research focusing on focal neuropathies. Despite this focus, researchers have also investigated the ultrasonographic changes that occur in the nerves and muscles of those with more diffuse polyneuropathies and motor neuron diseases, and this review will detail the findings in these conditions. Specific findings are discussed in this article, but general themes will also be presented and include the following: hereditary polyneuropathies show diffuse nerve enlargement, whereas immune-mediated polyneuropathies show more patchy involvement; nerve enlargement is more profound in demyelinating than axonal polyneuropathies; and muscle changes in motor neuron diseases include heterogeneous increases in echogenicity, atrophy, readily detectable fasciculations, and increased subcutaneous tissue thickness.

Leprosy with ulnar nerve abscess: ultrasound findings in a child

We report the ultrasound findings of a typical case of nerve abscess due to leprosy in an 11-year-old boy. The patient had previously undergone pediatric multibacillary leprosy multidrug therapy (MDT) in accordance with World Health Organization guidelines. He presented to our service with bilateral ulnar neuritis with no response to prednisone (1 mg/kg). Right ulnar nerve ultrasound revealed nerve hypoechogenicity, fascicular pattern disorganization, marked fusiform thickening, and a round anechoic area suggestive of intraneural abscess. Intense intraneural power Doppler signal was detected, indicating active neuritis. Intravenous methylprednisolone had a poor response and the patient was submitted to ulnar nerve decompression, which confirmed nerve abscess with purulent discharge during surgery. As the patient weighed more than 40 kg, treatment with a pediatric dose was considered insufficient and adult-dose MDT was prescribed, with improvement of nerve pain and function. Although leprosy is rare in developed countries, it still exists in the USA and it is endemic in many developing countries. Leprosy neuropathy is responsible for the most serious complications of the disease, which can lead to irreversible impairments and deformities. Nerve abscess is an uncommon complication of leprosy and ultrasound can efficiently demonstrate this condition, allowing for prompt treatment. There is scant literature about the imaging findings of nerve abscess in leprosy patients. Radiologists should suspect leprosy in patients with no other known causes of neuropathy when detecting asymmetric nerve enlargement and nerve abscess on ultrasound.

Ultrasonography of Leprosy Neuropathy: A Longitudinal Prospective Study

BACKGROUND

Previous studies have shown that leprosy multi-drug therapy (MDT) does not stop the progression of nerve function impairment. There are no prospective studies investigating the evolution of nerve anatomic abnormalities after treatment. We examined leprosy patients aiming to investigate the evolution of nerve ultrasonography (US) abnormalities and the risk factors for poor outcomes after MDT.

METHODOLOGY/PRINCIPAL FINDINGS

We performed bilateral US of the ulnar (U), median (M) and common fibular (CF) nerves in 9 paucibacillary (PB) and 64 multibacillary (MB) patients before and after MDT. Forty-two patients had leprosy reactions (type 1, type 2, acute neuritis) during the study. We analyzed nerve maximum cross-sectional areas (CSA), echogenicity and Doppler signal. Poor outcomes included a post-treatment CSA above normal limits with a reduction of less than 30% (U, M) or 40% (CF) from the baseline, echogenicity abnormalities or intraneural Doppler in the post-treatment study. We found that PB and patients without reactions showed significant increases in CSA at CF, whereas MB and patients with reactions had CSA reduction in some nerves after treatment (p<0.05). Despite this reduction, we observed a greater frequency of poor CSA outcomes in the MB compared to the PB (77.8% and 40.6%; p>0.05) and in the patients with reactions compared to those without (66.7% and 38.7%; p<0.05). There was significantly higher odds ratio (7.75; 95%CI: 1.56-38.45) for poor CSA outcomes only for M nerve in patients with reactions. Poor echogenicity outcomes were more frequent in MB (59.4%) compared to PB (22.2%) (p<0.05). There was significant association between poor Doppler outcomes and neuritis. Gender, disease duration, and leprosy classification were not significant risk factors for poor outcomes in CSA, echogenicity or Doppler.

CONCLUSIONS/SIGNIFICANCE

US nerve abnormalities can worsen after treatment despite the leprosy classification or the presence of reactions.

Atraumatic Main-En-Griffe due to Ulnar Nerve Leprosy

Background

Leprosy is the most common form of treatable peripheral neuropathy. However, in spite of effective chemotherapeutic agents, neuropathy and associated deformities are seldom ameliorated to a significant extent. This necessitates early diagnosis and treatment. Clinical examination of peripheral nerves is highly subjective and inaccurate. Electrophysiological studies are painful and expensive. Ultrasonography circumvents these demerits and has emerged as the preferred modality for probing peripheral nerves.

Case Report

We describe a 23-year-old male who presented with weakness and clawing of the medial digits of the right hand (main-en-griffe) and a few skin lesions since eighteen months. The right ulnar nerve was thickened and exquisitely tender on palpation. Ultrasonography revealed an extensive enlargement of the nerve with presence of intraneural color Doppler signals suggestive of acute neuritis. Skin biopsy was consistent with borderline tuberculoid leprosy with type 1 lepra reaction. The patient was started on WHO multidrug therapy for paucibacillary leprosy along with antiinflammatory drugs. Persistence of vascular signals at two months’ follow-up has led to continuation of the steroid therapy. The patient is compliant with the treatment and is on monthly follow-up.

Conclusions

In this manuscript, we review multitudinous roles of ultrasonography in examination of peripheral nerves in leprosy. Ultrasonography besides diagnosing enlargement of nerves in leprosy and acute neuritis due to lepra reactions, guides the duration of anti-inflammatory therapy in lepra reactions. Further, it is relatively inexpensive, non-invasive and easily available. All these features make ultrasonography a preferred modality for examination of peripheral nerves.

Application of Ultrasonography in the Diagnosis of Infectious Diseases in Resource-Limited Settings

Ultrasound (US) has vast potential in the field of infectious diseases, especially so in resource-limited settings. Recent technological advances have increased availability and access to ultrasound in low-resource settings, where the burden of infectious diseases is greatest. This paper collates the evidence for the utilization of ultrasound and evaluates its effectiveness in the diagnosis and management of a range of infectious diseases. This paper explores the role of ultrasound in population-based screening for specific diseases as well as highlights its benefits for individual patient management. We describe the common diagnostic signs seen on US for common and neglected parasitic, bacterial, and viral diseases. We proceed to document the emerging field of chest US which is proving to be a superior imaging modality for the diagnosis of specific pulmonary conditions. We conclude by discussing the efforts needed to formalize and rigorously evaluate the role of ultrasound in infectious diseases.

Ulnar nerve sonography in leprosy neuropathy

A 23-year-old woman presented with a half-year history of right forearm sensory and motor dysfunction. Ultrasound imaging revealed definite thickening of the right ulnar nerve trunk and inner epineurium, along with heterogeneous hypoechogenicity and unclear nerve fiber bundle. Color Doppler exhibited a rich blood supply, which was clearly different from the normal ulnar nerve presentation with a scarce blood supply. The patient subsequently underwent needle aspiration of the right ulnar nerve, and histopathological examination confirmed that granulomatous nodules had formed with a large number of infiltrating lymphocytes and a plurality of epithelioid cells in the fibrous connective tissues, with visible atypical foam cells and proliferous vascularization, consistent with leprosy. Our report will familiarize readers with the characteristic sonographic features of the ulnar nerve in leprosy, particularly because of the decreasing incidence of leprosy in recent years.

W, Foss NT, Frade MAC. Asymmetric Nerve Enlargement: A Characteristic of Leprosy Neuropathy Demonstrated by Ultrasonography

Background

Neurological involvement occurs throughout the leprosy clinical spectrum and is responsible for the most feared consequences of the disease. Ultrasonography (US) provides objective measurements of nerve thickening and asymmetry. We examined leprosy patients before beginning multi-drug therapy aiming to describe differences in US measurements between classification groups and between patients with and without reactions.

Methodology/Principal Findings

Eleven paucibacillary (PB) and 85 multibacillary (MB) patients underwent nerve US. Twenty-seven patients had leprosy reactions (type 1, type 2 and/or acute neuritis) prior to US. The ulnar (at the cubital tunnel–Ut–and proximal to the tunnel–Upt), median (M) and common fibular (CF) nerves were scanned to measure cross-sectional areas (CSAs) in mm² and to calculate the asymmetry indexes ΔCSA (absolute difference between right and left CSAs) and ΔUtpt (absolute difference between Upt and Ut CSAs). MB patients showed greater (p<0.05) CSAs than PB at Ut (13.88±11.4/9.53±6.14) and M (10.41±5.4/6.36±0.84). ΔCSAs and ΔUtpt were similar between PB and MB. The CSAs, ΔCSAs and ΔUtpt were similar between PB patients with reactions compared to PB patients without reactions. MB patients with reactions showed significantly greater CSAs (Upt, Ut and M), ΔCSAs (Upt and Ut) and ΔUtpt compared to MB patients without reactions. PB and MB showed similar frequencies of abnormal US measurements. Patients with reactions had higher frequency of nerve thickening and similar frequency of asymmetry to those without reactions.

Conclusions/Significance

This is the first study to investigate differences in nerve involvement among leprosy classification groups using US before treatment. The magnitude of thickening was greater in MB and in patients with reactions. Asymmetry indexes were greater in patients with reactions and did not significantly differ between PB and MB, demonstrating that asymmetry is a characteristic of leprosy neuropathy regardless of its classification.

Leprosy is an infectious disease that affects the peripheral nerves, leading to nerve thickening, asymmetry and dysfunction; therefore, early detection of leprosy neuropathy is important for preventing deformities and disabilities. We examined peripheral nerve involvement using ultrasonography (US) in 96 leprosy patients prior to treatment, aiming to better understand differences in neuropathy patterns between leprosy classification groups and between patients with and without leprosy reactions. Patients underwent bilateral US of the ulnar (at the cubital tunnel and proximal to the tunnel), median and common fibular nerves to measure thickening and asymmetry. We found that nerve thickening was more severe in patients with a high bacillary load (multibacillary) and in those with previous reactions. Nerve asymmetry measurements were greater in the patients with previous reactions. Asymmetry did not differ significantly between the paucibacillary and multibacillary patients, demonstrating that asymmetry is a characteristic of leprosy neuropathy regardless of its classification.

New sonographic measures of peripheral nerves: a tool for the diagnosis of peripheral nerve involvement in leprosy

To evaluate ultrasonographic (US) cross-sectional areas (CSAs) of peripheral nerves, indexes of the differences between CSAs at the same point (∆CSAs) and between tunnel (T) and pre-tunnel (PT) ulnar CSAs (∆TPTs) in leprosy patients (LPs) and healthy volunteers (HVs). Seventy-seven LPs and 49 HVs underwent bilateral US at PT and T ulnar points, as well as along the median (M) and common fibular (CF) nerves, to calculate the CSAs, ∆CSAs and ∆TPTs. The CSA values in HVs were lower than those in LPs (p < 0.0001) at the PT (5.67/9.78 mm2) and T (6.50/10.94 mm2) points, as well as at the M (5.85/8.48 mm2) and CF (8.17/14.14 mm2) nerves. The optimum CSA- receiver operating characteristic (ROC) points and sensitivities/specificities were, respectively, 6.85 mm2 and 68-85% for the PT point, 7.35 mm2 and 71-78% for the T point, 6.75 mm2 and 62-75% for the M nerve and 9.55 mm2 and 81-72% for the CF nerve. The ∆CSAs of the LPs were greater than those of the HVs at the PT point (4.02/0.85; p = 0.007), T point (3.71/0.98; p = 0.0005) and CF nerve (2.93/1.14; p = 0.015), with no difference found for the M nerve (1.41/0.95; p = 0.17). The optimum ∆CSA-ROC points, sensitivities, specificities and p-values were, respectively, 1.35, 49%, 80% and 0.003 at the PT point, 1.55, 55-85% and 0.0006 at the T point, 0.70, 58-50% and 0.73 for the M nerve and 1.25, 54-67% and 0.022 for the CF nerve. The ∆TPT in the LPs was greater than that in the HVs (4.43/1.44; p <0.0001). The optimum ∆TPT-ROC point was 2.65 (90% sensitivity/41% specificity, p < 0.0001). The ROC analysis of CSAs showed the highest specificity and sensitivity at the PT point and CF nerve, respectively. The PT and T ∆CSAs had high specificities (> 80%) and ∆TPT had the highest specificity (> 90%). New sonographic peripheral nerve measurements (∆CSAs and ∆TPT) provide an important methodological improvement in the detection of leprosy neuropathy.

Leprosy neuropathy: clinical presentations

Leprosy is a chronic infectious peripheral neuropathy caused by Mycobacterium leprae. The different clinical presentations of the disease are determined by the quality of the host immune response. Early detection of leprosy and treatment by multidrug therapy are the most important steps in preventing deformity and disability. Thus the early recognition of the clinical leprosy presentation is essential. Mononeuritis, mononeuritis multiplex (MM), polyneuritis (MM summation) are the most frequent. The frequent anesthetic skin lesions are absent in the pure neuritic leprosy presentation form. Isolated peripheral nerve involvement is common, including the cranial ones. Arthritic presentation is occasionally seen, usually misdiagnosed as rheumatoid arthritis. Attention should be given to autonomic dysfunctions in leprosy. There are clinical presentations with severe neuropathic pain - painful small-fiber neuropathy. Leprous late-onset neuropathy (LLON) clinical presentation should be considered facing a patient who develop an inflammatory neuropathy many years after a previous skin leprosy treatment.

Ultrasonography of peripheral nerves

Over the last decade, neuromuscular ultrasonography has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves, including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent articles outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasonography is well suited for use in electrodiagnostic laboratories, where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient's history, physical examination, electrophysiological studies, and imaging for diagnosis and management.

Leprous neuropathy

Leprous neuropathy, which is due to infection of nerve cells by Mycobacterium leprae, still affects millions of people in many developing countries. The clinical and pathological manifestations are determined by the natural resistance of the host to invasion of M. Leprae. Failure of early detection of leprosy often leads to severe disability in spite of eradication of mycobacterium at a later date. In the lepromatous type, bacilli are easily found in the skin and in nerve cells including Schwann cells, endothelial cells, and macrophages. In the tuberculoid type, a strong cell-mediated immune reaction leads to formation of granulomas and destruction of cells harboring bacilli and neighboring nerve fibers. In many cases, treatment of patients with the multibacillary leprosy is complicated by reversal reaction and further nerve damage. Nerve lesions lead to a symmetrical, pseudo-polyneuritic pattern in most cases of lepromatous leprosy, which is usually associated with typical skin lesions, but pure neuritic forms occur in up to 10% of patients with lepromatous leprosy. In the pure neuropathic cases, only nerve biopsy permits diagnosis. The multifocal pattern is more common in tuberculoid leprosy. Treatment is currently based on multidrug therapy with dapsone, rifampicin, and clofazimine. The use of corticosteroids can reduce or prevent nerve damage in reversal reactions. It is important to remember that sequelae, especially sensory loss, are extremely common, which can lead to secondary trophic changes due to repeated trauma in painless areas.

Comparative study of different surgical transposition methods for ulnar nerve entrapment at the elbow

This study compared the therapeutic effects of two techniques for surgical decompression treatment for ulnar nerve entrapment at the elbow: subcutaneous transposition and modified submuscular transposition with Z-lengthening of the pronator teres origin. A total of 278 patients with ulnar nerve entrapment (McGowan grades I - III) were randomly assigned to undergo one of these techniques. All patients were followed-up for 2 years. The effects were assessed by preoperative and postoperative cross-sectional area, motor conduction velocity, sensory conduction velocity and nerve action potential. All of these parameters improved after surgery in both groups. For patients with grade I disease, there were no significant differences between the two techniques. For patients with grade II and III disease, modified submuscular transposition was associated with significantly greater improvements compared with subcutaneous transposition. In conclusion, subcutaneous ulnar nerve transposition is recommended for grade I patients and modified submuscular ulnar nerve transposition for grade II and III patients.

Neuromuscular ultrasonography: quantifying muscle and nerve measurements

Neuromuscular ultrasonography can be used both descriptively and quantitatively in the evaluation of patients with neuromuscular disorders. This article reviews the quantitative use of this technology, particularly measurements of the size and echogenicity of nerve and muscle, as a tool for assessing the severity, progression, and response of these tissues to therapeutic interventions. Neuromuscular ultrasonography has several features, including portability and noninvasiveness, that make it an attractive research tool for advancing the diagnosis and treatment of neuromuscular disorders.