Ultrahigh-frequency ultrasound of fascicles in the common fibular, superficial fibular, and sural nerves.

INTRODUCTION/AIMS: While ultrasound assessment of cross-sectional area and echogenicity has gained popularity as a biomarker for various neuropathies, there is a scarcity of data regarding fascicle count and density in neuropathies or even healthy controls. The aim of this study was to determine whether fascicles within select lower limb nerves (common fibular, superficial fibular, and sural nerves) can be counted in healthy individuals using ultrahigh-frequency ultrasound (UHFUS). METHODS: Twenty healthy volunteers underwent sonographic examination of the common fibular, superficial fibular, and sural nerves on each lower limb using UHFUS with a 48 MHz linear transducer. Fascicle counts and density in each examined nerve were determined by a single rater. RESULTS: The mean fascicle number for each of the measured nerves included the following: common fibular nerve 9.85 (SD 2.29), superficial fibular nerve 5.35 (SD 1.59), and sural nerve 6.73 (SD 1.91). Multivariate linear regression analysis revealed a significant association between cross-sectional area and fascicle count for all three nerves. In addition, there was a significant association seen in the common fibular nerve between fascicle density and height, weight, and body mass index. Age and sex did not predict fascicle count or density (all p > .13). DISCUSSION: UHFUS enabled the identification and counting of fascicles and fascicle density in the common fibular, superficial fibular, and sural nerves. Knowledge about normal values and normal peripheral nerve architecture is needed in order to further understand and identify pathological changes that may occur within each nerve in different disease states.

Ultra high-frequency ultrasound of fascicles in the ulnar and radial nerves.

INTRODUCTION/AIMS: Ultra high-frequency ultrasound (UHFUS) has been demonstrated to allow easy visualization and quantification of median and digital nerve fascicles; however, there is a lack of normative data for other upper limb nerves. The purpose of this study was to use UHFUS to establish normative reference values and ranges for fascicle count and density within selected upper extremity nerves. METHODS: Twenty-one healthy volunteers underwent sonographic examination of the ulnar, superficial branch of the radial, and radial nerves on one upper limb using UHFUS with a 48 MHz linear transducer. The number of fascicles in each peripheral nerve and fascicle density were assessed. RESULTS: The mean fascicle number and fascicle density for each of the measured nerves was ulnar nerve at the wrist 11.7 and 2.0, ulnar nerve at the elbow 9.2 and 1.1, superficial branch of the radial nerve 7.3 and 2.5, and radial nerve at the spiral groove 4.2 and 0.8. A single significant association was observed between CSA and fascicle number in the ulnar nerve at the wrist (p = .023, r = 0.66). Neither fascicle number nor density could be predicted by age, sex, height, weight, or body mass index. DISCUSSION: UHFUS may help to establish a baseline of normative data on upper limb nerves that are not frequently biopsied due to their mixed motor and sensory functions and has the potential for increased understanding of nerve fascicular anatomy to improve diagnostic accuracy of focal nerve lesions, particularly those with selective fascicular involvement.

Porphyric neuropathy.

Acute hepatic porphyrias are inherited metabolic disorders that may present with polyneuropathy, which if not diagnosed early can lead to quadriparesis, respiratory weakness, and death. Porphyric neuropathy is an acute to subacute motor predominant axonal neuropathy with a predilection for the upper extremities and usually preceded by a predominantly parasympathetic autonomic neuropathy. The rapid progression and associated dysautonomia mimic Guillain-Barré syndrome but are distinguished by the absence of cerebrospinal fluid albuminocytologic dissociation, progression beyond 4 wk, and associated abdominal pain. Spot urine test to assess the porphyrin precursors delta-aminolevulinic acid and porphobilinogen can provide a timely diagnosis during an acute attack. Timely treatment with intravenous heme, carbohydrate loading, and avoidance of porphyrinogenic medications can prevent further neurological morbidity and mortality.

Molecular characterization of influenza virus circulating in Nepal in the year 2019.

Influenza (sometimes referred to as "flu") is a contagious viral infection of the airways in the lungs that affects a significant portion of the world's population. Clinical symptoms of influenza virus infections can range widely, from severe pneumonia to moderate or even asymptomatic sickness. If left untreated, influenza can have more severe effects on the heart, brain, and lungs than on the respiratory tract and can necessitate hospitalization. This study was aimed to investigate and characterize all types of influenza cases prevailing in Nepal and to analyze seasonal occurrence of Influenza in Nepal in the year 2019. A cross sectional, retrospective and descriptive study was carried out at National Influenza Center (NIC), National Public Health Laboratory Kathmandu Nepal for the period of one year (Jan-Dec 2019). A total of 3606 throat swab samples from various age groups and sexes were processed at the NIC. The specimens were primarily stored at 4 °C and processed using ABI 7500 RT PCR system for the identification of Influenza virus types and subtypes. Data accessed for research purpose were retrieved from National Influenza Centre (NIC) on 1st Jan 2020. Of the total 3606 patients suspected of having influenza infection, influenza viruses were isolated from 1213 (33.6%) patients with male predominance. The highest number of infection was caused by Influenza A/Pdm09 strain 739 (60.9%) followed by Influenza B 304 (25.1%) and Influenza A/H3 169 (13.9%) and most remarkable finding of this study was the detection of H5N1 in human which is the first ever case of such infection in human from Nepal. Similar to other tropical nations, influenza viruses were detected year-round in various geographical locations of Nepal. The influenza virus type and subtypes that were in circulation in Nepal were comparable to vaccine candidate viruses, which the currently available influenza vaccine may prevent.

Clinical Utility and Diagnostic Yield of Genetic Testing for Inherited Neuromuscular Disorders in a Single, Large Neuromuscular Center.

Background and Objectives: Most published studies on the clinical utility of genetic testing for neuromuscular diseases (NMDs) focus on disease-specific cohorts and/or involve multiple centers. The aim of this study was to examine the clinical utility and diagnostic yield of genetic testing at a single, large neuromuscular center. Unlike previous studies, this study is unique in that it includes a broad array of patients at a single, large neuromuscular center, providing real-world data that may assist both neuromuscular specialists as well as general neurologists in decision-making regarding the need for genetic testing in patients with suspected NMDs. Methods: Genetic testing results were reviewed for all patients who underwent testing through a single genetic testing company for NMDs in this single laboratory at a large neuromuscular center from 2015 to 2020. Retrospective chart reviews were performed to determine whether genetic testing results conferred a specific NMD diagnosis, including cases where a variant of uncertain significance (VUS) was identified. Results: Genetic testing was pursued for 192 patients. A positive result, defined as a pathogenic mutation, a VUS, or both, was found in 77.1%. A definitive diagnosis was conferred in 35.9%. The most common testing indication was suspected neuropathy (53.3%), and the indication with the highest diagnostic yield was suspected myopathy (48.7%). Discussion: This study provides further evidence of the clinical utility of genetic testing for NMDs in a real-world setting with over one-third of patients tested receiving a definitive diagnosis. Over time, genetic testing will continue to become increasingly accessible, cost-effective, and sensitive, which will lead to even more utilization.

Knowledge, practice, and infection status of prisoners toward dermatomycosis: a study in Nepal.

Background: Dermatophytosis, commonly known as tinea, poses a significant public health concern worldwide, especially in environments with poor hygiene and overcrowding, such as prisons. Despite its prevalence and impact on quality of life, there is a lack of research on the knowledge and hygiene practices regarding dermatophytosis among prisoners, particularly in Nepal. Objective: The study aimed to assess prisoners' knowledge, hygiene practice and infection status regarding dermatophytosis in Central Prison, Nepal. Methods: A descriptive cross-sectional study with a sample size of 184 respondents was designed to collect data using a validated pre-tested questionnaire from September 2023 to January 2024. The collected data was then analyzed using IBM SPSS version 21. Knowledge and hygiene practices were measured on an eight and 11-point scale and rated as poor (≤4) and sound (>4), bad (≤6), and good (>6), respectively. Summary data were presented by descriptive, while Chi-square and logistic regression were used for inferential statistics at p < 0.05. Results: The findings revealed moderate knowledge among prisoners regarding dermatophytosis, with significant gaps in understanding its spread and prevention. While most prisoners recognized the importance of treatment, there were misconceptions about the inevitability of contracting dermatophytosis and the role of personal hygiene. Conclusion: Despite good knowledge levels, adherence to recommended hygiene practices was suboptimal, highlighting the need for targeted interventions. The study underscores the importance of addressing knowledge gaps, changing attitudes, and promoting hygienic practices to mitigate the burden of dermatophytosis among prisoners.

Ultrasound Scanning Protocol in the Assessment of Ulnar Neuropathy at the Elbow.

Ulnar neuropathy at the elbow is commonly encountered in clinical practice and is the second most common entrapment neuropathy. Left untreated, ulnar neuropathy at the elbow can result in significant disability due to loss of dexterity and grip strength secondary to the weakness of intrinsic hand muscles. Precisely localizing a lesion in ulnar neuropathy can be challenging with electrodiagnostic testing alone. Ultrasound is a relatively quick and useful adjunctive diagnostic modality in overcoming this limitation, as an increase in the cross-sectional area (CSA) of the nerve is a common and validated finding in ulnar neuropathies at the elbow. Sonographic assessment of the nerve's echotexture and vascularity can provide additional diagnostic clues. Ultrasound also offers the unique benefit of detecting ulnar nerve subluxation or dislocation out of the retroepicondylar groove during dynamic assessment, although the clinical significance of this is controversial. Finally, ultrasound can also identify structural abnormalities leading to nerve compressions, such as the presence of bony abnormalities, scar tissue, and space-occupying lesions. These findings may influence management strategies and surgical planning. This protocol aims to illustrate the technique of static and dynamic sonographic imaging of the ulnar nerve around the elbow as a complement to electrodiagnostic testing in the assessment of ulnar neuropathy at the elbow.

Neuromuscular Ultrasound of the Median Nerve at the Carpal Tunnel.

The use of neuromuscular ultrasound greatly enhances the evaluation of carpal tunnel syndrome as an adjunct diagnostic tool as it provides dynamic and structural information about the median nerve and its surrounding anatomy. Neuromuscular ultrasound aids in diagnostic accuracy (when used with electrodiagnostic testing) and offers etiologic information as a non-invasive, painless, cost-effective, and radiation-free imaging technology that can be easily carried out at the bedside for immediate interpretation. Neuromuscular ultrasound has the limitation of subjectivity, and the need for training and experience will affect the interpretation of results. This article describes a basic practical guide to visualizing the median nerve using neuromuscular ultrasound in a step-by-step manner to aid in the evaluation of carpal tunnel syndrome. Even though the use of ultrasound in the assessment of median nerve entrapment has been long established, there has been no recognized standard protocol. The present protocol aims to provide clear and concise instructions to describe a standard technique to visualize the median nerve through diagnostic ultrasound.

Monkeypox and Its Possible Sexual Transmission: Where Are We Now with Its Evidence?

Monkeypox is a rare disease but is increasing in incidence in different countries since the first case was diagnosed in the UK by the United Kingdom (UK) Health Security Agency on 6 May 2022. As of 9 August, almost 32,000 cases have been identified in 89 countries. In endemic areas, the monkeypox virus (MPXV) is commonly transmitted through zoonosis, while in non-endemic regions, it is spread through human-to-human transmission. Symptoms can include flu-like symptoms, rash, or sores on the hands, feet, genitalia, or anus. In addition, people who did not take the smallpox vaccine were more likely to be infected than others. The exact pathogenesis and mechanisms are still unclear; however, most identified cases are reported in men who have sex with other men (MSM). According to the CDC, transmission can happen with any sexual or non-sexual contact with the infected person. However, a recent pooled meta-analysis reported that sexual contact is involved in more than 91% of cases. Moreover, it is the first time that semen analysis for many patients has shown positive monkeypox virus DNA. Therefore, in this review, we will describe transmission methods for MPXV while focusing mainly on potential sexual transmission and associated sexually transmitted infections. We will also highlight the preventive measures that can limit the spread of the diseases in this regard.

Diagnostic performance of GeneXpert MTB/RIF assay compared to conventional Mycobacterium tuberculosis culture for diagnosis of pulmonary and extrapulmonary tuberculosis, Nepal.

Tuberculosis is an infectious disease caused by the Mycobacterium tuberculosis. It is a global health problem and major cause of death in resource-limited countries like Nepal. Timely diagnosis with sensitive testing methods could assist in early management of the disease. This study was conducted to compare the diagnostic performance of GeneXpert MTB/RIF and conventional acid-fast staining with M. tuberculosis culture. The study was carried out in the Department of Microbiology, Shree Birendra Army Hospital, Nepal. Samples (n=500) were tested with a GeneXpert MTB/RIF assay and acid-fast bacilli (AFB) smear microscopy. All samples were sent for M. tuberculosis conventional culture by the German-Nepal Tuberculosis Project, Kathmandu, Nepal (GENETUP). Out of a total 500 pulmonary and extrapulmonary samples tested, 97 samples were positive for M. tuberculosis by GeneXpert MTB/RIF assay. Out of the positive samples, only 95 samples were found positive by the culture method. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of AFB microscopy was 45.3%, 99.5%, 99.5% and 88.5%, respectively. The sensitivity, specificity, PPV and NPV of GeneXpert MTB/RIF was found to be 100%, 99.5%, 97.5% and 100%, respectively compared to the gold standard culture method. The GeneXpert MTB/RIF test was comparable with culture diagnosis of both pulmonary and extrapulmonary tuberculosis cases.

Airborne transmission of SARS-CoV-2 is the dominant route of transmission: droplets and aerosols.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a pandemic worldwide. On a daily basis the number of deaths associated with COVID-19 is rapidly increasing. The main transmission route of SARS-CoV-2 is through the air (airborne transmission). This review details the airborne transmission of SARS-CoV-2, the aerodynamics, and different modes of transmission (e.g. droplets, droplet nuclei, and aerosol particles). SARS-CoV-2 can be transmitted by an infected person during activities such as expiration, coughing, sneezing, and talking. During such activities and some medical procedures, aerosols and droplets contaminated with SARS-CoV-2 particles are formed. Depending on their sizes and the environmental conditions, such particles stay viable in the air for varying time periods and can cause infection in a susceptible host. Very few studies have been conducted to establish the mechanism or the aerodynamics of virus-loaded particles and droplets in causing infection. In this review we discuss the various forms in which SARS-CoV-2 virus particles can be transmitted in air and cause infections.