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.

NerveTracker: a Python-based software toolkit for visualizing and tracking groups of nerve fibers in serial block-face microscopy with ultraviolet surface excitation images.

Significance: Information about the spatial organization of fibers within a nerve is crucial to our understanding of nerve anatomy and its response to neuromodulation therapies. A serial block-face microscopy method [three-dimensional microscopy with ultraviolet surface excitation (3D-MUSE)] has been developed to image nerves over extended depths ex vivo. To routinely visualize and track nerve fibers in these datasets, a dedicated and customizable software tool is required. Aim: Our objective was to develop custom software that includes image processing and visualization methods to perform microscopic tractography along the length of a peripheral nerve sample. Approach: We modified common computer vision algorithms (optic flow and structure tensor) to track groups of peripheral nerve fibers along the length of the nerve. Interactive streamline visualization and manual editing tools are provided. Optionally, deep learning segmentation of fascicles (fiber bundles) can be applied to constrain the tracts from inadvertently crossing into the epineurium. As an example, we performed tractography on vagus and tibial nerve datasets and assessed accuracy by comparing the resulting nerve tracts with segmentations of fascicles as they split and merge with each other in the nerve sample stack. Results: We found that a normalized Dice overlap ( Dice norm ) metric had a mean value above 0.75 across several millimeters along the nerve. We also found that the tractograms were robust to changes in certain image properties (e.g., downsampling in-plane and out-of-plane), which resulted in only a 2% to 9% change to the mean Dice norm values. In a vagus nerve sample, tractography allowed us to readily identify that subsets of fibers from four distinct fascicles merge into a single fascicle as we move ∼ 5 mm along the nerve's length. Conclusions: Overall, we demonstrated the feasibility of performing automated microscopic tractography on 3D-MUSE datasets of peripheral nerves. The software should be applicable to other imaging approaches. The code is available at https://github.com/ckolluru/NerveTracker.

Mapeo sonográfico de los nervios de la cara medial del tobillo y del pie / Sonographic mapping of the nerves of the medial side of the ankle and foot

El uso de los ultrasonidos en el examen, la identificación y el intervencionismo de las diferentes ramas nerviosas del tobillo y del pie son una herramienta de gran apoyo en el ámbito clínico. En la actualidad, la ecografía es un método que se ha ido universalizando en el mundo de la podología, bien por su mayor accesibilidad debido al abaratamiento de los costes, a los avances tecnológicos y a sus beneficios de inocuidad, fácil disponibilidad para el examen inmediato y su aplicación dinámica en la evaluación de las diferentes estructuras anatómicas. El presente trabajo trata de presentar a la comunidad podológica una descripción detallada del mapeo mediante ecografía de los nervios en cara medial del pie. Entendemos que esta descripción puede ayudar a los profesionales en el diagnóstico de las patologías de atrapamiento nervioso a dicho nivel, así como en procedimientos mínimamente invasivos guiados ecográficamente en dicha área anatómica.(AU)

The use of ultrasound in clinical practice is a great tool for the examination, identification and intervention of the different nerve branches in the foot and ankle. Nowadays, sonography is an exploratory method that has been universally expanded in podiatry because of lowering of costs associated to its use, technological progresses and its benefits of safety, disposal for the inmediate clinical exam and its dynamic application in the evaluation of different structures. The aim of the present paper is to present to the podiatry community a detailed description of sonographic mapping of the nerves in the medial side of the ankle. It is intended to help professionals involved in the management of foot ankle disorders regarding the diagnosis of entrapment neuropathies at this level and also to help with minimally invasive treatments sonographically guided.(AU)

Propuesta de abordaje para bloqueo selectivo del nervio tibial en paciente espástico. A propósito de un caso / Proposal for approach to selective tibial nerve block in spastic patient. A propos of a case

El patrón más frecuente de espasticidad en el miembro inferior es el pie equino-varo. En pacientes con daño en el sistema nervioso central y espasticidad severa es frecuente que el tratamiento conservador y la toxina botulínica tipo A presenten un efecto limitado. En estos casos, los bloqueos nerviosos pueden ser de mucha utilidad para decidir nuestra actuación terapéutica. Presentamos un caso clínico como ejemplo de abordaje ecoguiado novedoso para el bloqueo del principal nervio involucrado en este patrón de pie equino-varo como es el nervio tibial, adaptado a la idiosincrasia de los pacientes espásticos y su utilidad para el manejo clínico de la espasticidad (AU)

The most frequent pattern of spasticity in the lower limb is equinovarus foot. Patients with central nervous system injury and severe spasticity, conservative treatment and botulinum toxin type A often have a limited effect. In these cases, nerve blocks can be very useful in deciding our therapeutic action. We present a clinical case as an example of a new ultrasound-guided approach to tibial nerve block, as this is the main nerve involved in equinovarus foot pattern, specific for spastic patients and its usefulness for the clinical management of spasticity (AU)