Effect of Long-term Peripheral Nerve Stimulation on Neuro-Muscular Complex Morphologic Recovery in Experiment / Efecto de la Estimulación del Nervio Periférico a Largo Plazo sobre la Recuperación Morfológica del Complejo Neuromuscular en Experimento

SUMMARY: Peripheral nerve injury is an extremely important medical and socio-economic problem. It is far from a solution, despite on rapid development of technologies. To study the effect of long-term electrical stimulation of peripheral nerves, we used a domestically produced electrical stimulation system, which is approved for clinical use. The study was performed on 28 rabbits. Control of regeneration was carried out after 3 month with morphologic techniques. The use of long-term electrostimulation technology leads to an improvement in the results of the recovery of the nerve trunk after an injury, both directly at the site of damage, when stimulation begins in the early period, and indirectly, after the nerve fibers reach the effector muscle.

La lesión de los nervios periféricos es un problema médico y socioeconómico extremadamente importante. Sin embargo, y a pesar del rápido desarrollo de las tecnologías, aún no tiene solución. Para estudiar el efecto de la estimulación eléctrica a largo plazo de los nervios periféricos, utilizamos un sistema de estimulación eléctrica de producción nacional, que está aprobado para uso clínico. El estudio se realizó en 28 conejos. El control de la regeneración se realizó a los 3 meses con técnicas morfológicas. El uso de tecnología de electro estimulación a largo plazo conduce a una mejora en los resultados de la recuperación del tronco nervioso después de una lesión, tanto directamente en el lugar del daño, cuando la estimulación comienza en el período temprano, como indirectamente, después de que las fibras nerviosas alcanzan el músculo efector.

3D-Structural Characterization of MicroRNA Expressed in Leprosy / Caracterização Estrutural em 3D de MicroRNAs Expressos na Hanseníase

Introduction: Hansen's disease, or leprosy is caused by Mycobacterium leprae (M. leprae), is a major public health problem in developing countries, and affecting the skin and peripheral nerves. However, M. leprae can also affect bone tissue, mucous membranes, liver, eyes, and testicles, producing a variety of clinical phenotypes. MicroRNAs (miRNAs) have been expressed in the various clinical forms of leprosy and could potentially be used for its diagnosis. Objective: in silico design of the molecular structure of miRNAs expressed in leprosy. Methodology: we performed a nucleotide sequence search of 17 miRNAs expressed in leprosy, designing in silico the molecular structure of the following miRNAs: miRNA-26a, miRNA-27a, miRNA-27b, miRNA-29c, miRNA-34c, miRNA-92a-1, miRNA- 99a-2, miRNA-101-1, miRNA-101-2, miRNA-125b-1, miRNA-196b, miRNA-425-5p, miRNA-452, miRNA-455, miRNA-502, miRNA-539, and miRNA-660. We extracted the nucleotides were from the GenBank of National Center for Biotechnology Information genetic sequence database. We aligned the extracted sequences with the RNA Folding Form, and the three-dimensional molecular structure design was performed with the RNAComposer. Results: we demonstrate the nucleotide sequences, and molecular structure projection of miRNAs expressed in leprosy, and produces a tutorial on the molecular model of the 17 miRNAs expressed in leprosy through in silico projection processing of their molecular structures. Conclusion: we demonstrate in silico design of selected molecular structures of 17 miRNAs expressed in leprosy through computational biology.

Introdução: a doença de Hansen, ou hanseníase é causada pelo Mycobacterium leprae (M. leprae), é um grande problema de saúde pública nos países em desenvolvimento e afeta, a pele e os nervos periféricos. Entretanto, o M. leprae também pode comprometer o tecido ósseo, membranas mucosas, fígado, olhos e testículos, produzindo uma variedade de fenótipos clínicos. MicroRNAs (miRNAs) têm sido expressos nas várias formas clínicas da hanseníase e podem ser potencialmente utilizados para seu diagnóstico. Objetivo: objetivou-se com esse experimento modelar computacionalmente a estrutura molecular dos miRNAs expressos na hanseníase. Metodologia: realizou-se como metodologia uma pesquisa das sequências nucleotídicas de 17 miRNAs expressos na hanseníase, desenhando em modelo computacional a estrutura molecular dos seguintes miRNAs: miRNA-26a, miRNA-27a, miRNA-27b, miRNA- 29c, miRNA-34c, miRNA-92a-1, miRNA-99a-2, miRNA-101-1, miRNA-101-2, miRNA-125b-1, miRNA-196b, miRNA-425-5p, miRNA-452, miRNA-455, miRNA-502, miRNA-539, e miRNA-660. Extraiu-se os nucleotídeos do banco de dados do GenBank of National Center for Biotechnology Information . Alinhou-se as sequências extraídas com o RNA Folding Form, e o projeto da estrutura molecular tridimensional foi realizado com o RNAComposer. Resultados: demonstrou-se como resultados as sequências dos nucleotídeos e a projeção da estrutura molecular dos miRNAs expressos na hanseníase, e produzimos um tutorial sobre o modelo molecular dos 17 miRNAs expressos em hanseníase através do processamento de suas estruturas moleculares em projeção computacional. Conclusão: foi demonstrado computacionalmente o projeto de estruturas moleculares selecionadas de 17 miRNAs expressos em hanseníase através da biologia computacional.

Schwannoma intraóseo en fémur, una presentación inusual. Reporte de caso / Intraosseous Schwannoma in femur, an unusual presentation. Case report

El Schwannoma o Neurilemoma es un tumor benigno de derivación neuroectodérmica que se origina en las células de Schwann, que constituyen la envoltura de los nervios. Es el tumor benigno más común de los nervios periféricos, tiene predisposición a originarse a partir de nervios periféricos sensoriales y puede presentarse como tumores en tejidos blandos. La presentación intraósea del Schwannoma es rara y corresponde al 0,2% de los tumores óseos primarios. Se presenta caso clínico de paciente masculino de 36 años de edad con tumor en cóndilo femoral medial de rodilla derecha de 4 años de evolución, cursando con dolor intermitente moderado a quien se le practicó el protocolo oncológico, imagenológico e histológico, de la Unidad de Oncología Ortopédica del estado Monagas. Se diagnosticó Schwannoma intraóseo, se procedió a realizar resección marginal y reconstrucción con alloinjerto y fijación con placa y tornillos con excelente evolución postoperatoria. El Schwannoma intraóseo es extraordinariamente raro y su ubicación en el fémur lo es aún más. El objetivo del presente trabajo es reportar un caso de Schwannoma Intraóseo, mostrar las estrategias para su diagnóstico y los tratamientos aplicados, así como la revisión de los datos al respecto existentes en la literatura(AU)

Schwannoma or Neurilemoma is a benign tumor of neuroectodermal derivation that originates in Schwann cells, which constitute the nerve sheath. It is the most common benign tumor of the peripheral nerves, has a predisposition to originate from peripheral sensory nerves, and can present as soft tissue tumors. The intraosseous presentation of Schwannoma is rare and corresponds to 0,2% of primary bone tumors. A clinical case of a 36-yearold male patient with a tumor in the medial femoral condyle of the right knee of 4 years of evolution is presented, presenting with moderate intermittent pain who underwent the oncological, imaging and histological protocol of the Oncology Unit. Monagas State Orthopedic. Intraosseous Schwannoma was diagnosed, marginal resection and allograft reconstruction and plate and screw fixation were performed with excellent postoperative evolution. Intraosseous Schwannoma is extraordinarily rare and its location in the femur is even more so. The objective of this paper is to report a case of Intraosseous Schwannoma, show the strategies for its diagnosis and the treatments applied, as well as the review of the existing data in the literature(AU)

Upper limb nerve variations may alter clinical diagnosis: a scoping review / Las variaciones nerviosas del miembros superior pueden alterar el diagnóstico clínico: una revisión de alcance

SUMMARY: Upper limb nerve variations may be related to the absence of a nerve, an interconnection between two nerves or a variant course. The purpose of this review is to screen the existing literature on upper limb nerve variations that may alter the neurologic diagnostic process. A scoping review was performed following PRISMA for Scoping Reviews guidelines. Initially, 1331 articles were identified by searching Pubmed and Web of Science until the 22nd of October 2022. After screening, reading, and additional searching 50 articles were included in this review. Variations were divided into two categories: 1) variations causing a different innervation pattern involving sensory, motor, or both types of fibers, and 2) variations causing or related to compression syndromes. Two-thirds of the included articles were cadaver studies. Nine articles were diagnostic studies on symptomatic or healthy individuals involving medical imaging and/or surgery. Nerve variations that may cause a different innervation pattern concern most frequently their interconnection. The connection between the median and musculocutaneous nerve in the upper limb and the connection between the median and ulnar nerve in the forearm (Martin-Gruber) or hand (Riche-Cannieu) may be present in half of the population. Injury to these connections may cause compound peripheral neuropathies a result of variant sensory and motor branching patterns. Muscular, vascular, or combined anomalies in the forearm were reported as causes of entrapment neuropathies. These nerve variations may mimic classical entrapment syndromes such as carpal tunnel syndrome or compression at ulnar canal (Guyon's canal). Knowledge of frequent nerve variations in the arm may be important during the diagnostic process and examination. Variant innervation patterns may explain non-classical clinical signs and/or symptoms during provocative tests. Classical nerve compression syndromes in the arm may warrant for differential diagnosis, especially in the case of persistent or recurrent symptoms.

Las variaciones nerviosas del miembro superior pueden estar relacionadas con la ausencia de un nervio, una interconexión entre dos nervios o un curso variante. El objetivo de esta revisión fue examinar la literatura existente sobre las variaciones de los nervios de los miembros superiores que pueden alterar el proceso de diagnóstico neurológico. Se realizó una revisión de alcance siguiendo las pautas de PRISMA para revisiones de alcance. Inicialmente, se identificaron 1331 artículos mediante la búsqueda en Pubmed y Web of Science hasta el 22 de octubre de 2022. Después de la selección, la lectura y la búsqueda adicional, se incluyeron 50 artículos en esta revisión. Las variaciones se dividieron en dos categorías: 1) variaciones que causan un patrón de inervación diferente que involucra fibras sensoriales, motoras o de ambos tipos, y 2) variaciones que causan o están relacionadas con síndromes de compresión. Dos tercios de los artículos incluidos eran estudios de cadáveres. Nueve artículos fueron estudios de diagnóstico en individuos sintomáticos o sanos que involucraron imágenes médicas y/o cirugía. Las variaciones nerviosas que pueden causar un patrón de inervación diferente se refieren con mayor frecuencia a su interconexión. La conexión entre el nervio mediano y musculocutáneo en el miembro superior y la conexión entre el nervio mediano y ulnar en el antebrazo (Martin-Gruber) o la mano (Riche-Cannieu) puede estar presente en la mitad de la población. La lesión de estas conexiones puede causar neuropatías periféricas compuestas como resultado de patrones de ramificación variantes sensitivos y motores. Se informaron anomalías musculares, vasculares o combinadas en el antebrazo como causas de neuropatías por atrapamiento. Estas variaciones nerviosas pueden imitar los síndromes de atrapamiento clásicos, como el síndrome del túnel carpiano o la compresión en el canal ulnar. El conocimiento de las variaciones nerviosas frecuentes en el brazo puede ser importante durante el proceso de diagnóstico y examen. Los patrones de inervación variantes pueden explicar los signos y/o síntomas clínicos no clásicos durante las pruebas de provocación. Los síndromes clásicos de compresión nerviosa en el brazo pueden justificar el diagnóstico diferencial, especialmente en el caso de síntomas persistentes o recurrentes.

Lepra de presentación focal en un paciente con mononeuropatía cubital en Uruguay / Focal presentation leprosy in a patient with ulnar mononeuropathy in Uruguay

La lepra, o enfermedad de Hansen (EH), es una enfermedad infectocontagiosa crónica de evolución lenta, causada por el bacilo Mycobacterium Leprae. Resulta un problema de salud importante en áreas endémicas con un gran impacto en la calidad de vida de los pacientes. Actualmente, se presenta como una causa infrecuente de neuropatía en nuestra región, pero su sospecha diagnóstica y su tratamiento precoz repercute a nivel pronóstico y funcional. Nuestro objetivo es analizar un caso único de Enfermedad de Hansen en nuestro país, haciendo enfoque en la presentación clínica y el abordaje médico-quirúrgico. Se presenta un paciente con un cuadro de debilidad progresiva de mano izquierda y una lesión de piel cronificada a nivel de codo, cuyos hallazgos clínicos, neurofisiológicos e imagenológicos fueron concordantes con una lesión del nervio cubital por atrapamiento en el conducto epitrócleo-olecraneano. La anatomía patológica mostró un proceso granulomatoso crónico y la baciloscopia fue positiva para bacilos ácido-alcohol resistentes con coloración de Hansel positiva, haciéndose diagnóstico de mononeuropatía cubital secundaria a infección por M. Leprae. Dada la severidad del compromiso nervioso, se realiza cirugía de nervio periférico con epineurotomía y descompresión nerviosa. En el caso de nuestro paciente con neuropatía cubital secundaria a enfermedad de Hansen, la cirugía descompresiva fue exitosa en el alivio del dolor, mostrándose como una opción terapéutica de relevancia en este tipo de pacientes(AU)

Leprosy, or Hansen disease, is a cronic infectious-contagious illness of slow progression that is caused by the bacillus Mycobacterium Leprae. It continues to be a major health problem in endemic areas and has a great impact on the quality of life of patients who suffer from it. It is currently presented as an infrequent cause of neuropathy in our region, but its diagnostic suspicion and therefore its early treatment have repercussions at the prognostic and functional level. Our goal is to analyze a unique case of Hansen's disease in our country, focusing on the clinical presentation and the medical-surgical approach. We present a patient with progressive weakness of the left hand and a chronic skin lesion at the level of the elbow, whose clinical, neurophysiological and imaging findings were consistent with an ulnar nerve injury due to entrapment in the epitrochlear-olecranon canal. The pathology showed a chronic granulomatous process; then bacilloscopy was performed, which was positive for acid-fast bacilli with positive Hansel staining, making a diagnosis of ulnar mononeuropathy secondary to infection by M. Leprae. Given the severity of the nerve involvement, peripheral nerve surgery with epineurotomy and nerve decompression was performed.In the case of our patient with ulnar neuropathy secondary to Hansen's disease, decompressive surgery was successful in relieving pain, proving to be a relevant therapeutic option in this type of patient

Time-dependent proregenerative effects of exogenous melatonin on the transected sciatic nerve / Efectos proregenerativos dependientes del tiempo de la melatonina exógena en el nervio ciático seccionado

SUMMARY: Microsurgical procedures are the treatment of choice of peripheral nerve injuries, but often fail to reach full functional recovery. Melatonin has neuroprotective actions and might be used as a possible proregenerative pharmacological support. Therefore, the aim of this study was to analyze the time-dependence of the neuroprotective effect of melatonin on the overall fascicular structures of both ends of the transected nerve. Sciatic nerve transection was performed in 34 adult male Wistar rats divided in four groups: two vehicle groups (N=7) treated intraperitoneally for 7 (V7) or 21 (V21) consecutive days with vehicle (5 % ethanol in Ringer solution) and two melatonin groups (N=10) administered intraperitoneally 30 mg/kg of melatonin for 7 (M7) or 21 (M21) consecutive days. At the end of the experiment, proximal stump neuroma and distal stump fibroma were excised and processed for qualitative and quantitative histological analysis. Intrafascicular neural structures were better preserved and the collagen deposition was reduced in the melatonin treated groups than in the vehicle groups. Myelin sheath regeneration observed through its thickness measurement was statistically significantly (p<0,05) more pronounced in the M21 (1,23±0,18 µm) vs. V21 group (0,98±0,13 µm). The mean volume density of the endoneurium was lower in both melatonin treated groups in comparison to the matching vehicle treated groups. Although not statistically different, the endoneural tube diameter was larger in both melatonin groups vs. vehicle groups, and the effect of melatonin was more pronounced after 21 days (24,97 % increase) vs. 7 days of melatonin treatment (18,8 % increase). Melatonin exerts a time-dependent proregenerative effect on nerve fibers in the proximal stump and an anti-scarring effect in both stumps.

Los procedimientos microquirúrgicos son el tratamiento de elección de las lesiones de los nervios periféricos, pero a menudo no logran una recuperación funcional completa. La melatonina tiene acciones neuroprotectoras y podría ser utilizada como un posible apoyo farmacológico proregenerativo. Por lo tanto, el objetivo de este estudio fue analizar la dependencia del tiempo del efecto neuroprotector de la melatonina sobre las estructuras fasciculares generales de ambos extremos del nervio seccionado. La sección del nervio ciático se realizó en 34 ratas Wistar macho adultas divididas en cuatro grupos: dos grupos de vehículo (N=7) tratados por vía intraperitoneal durante 7 (V7) o 21 (V21) días consecutivos con vehículo (5 % de etanol en solución Ringer) y dos grupos grupos de melatonina (N=10) a los que se les administró por vía intraperitoneal 30 mg/kg de melatonina durante 7 (M7) o 21 (M21) días consecutivos. Al final del experimento, se extirparon y procesaron el neuroma del muñón proximal y el fibroma del muñón distal del nervio para un análisis histológico cualitativo y cuantitativo. Las estructuras neurales intrafasciculares se conservaron mejor y el depósito de colágeno se redujo en los grupos tratados con melatonina respecto a los grupos con vehículo. La regeneración de la vaina de mielina observada a través de la medición de su espesor fue estadísticamente significativa (p<0,05) más pronunciada en el grupo M21 (1,23±0,18 µm) vs V21 (0,98±0,13 µm). La densidad de volumen media del endoneuro fue menor en ambos grupos tratados con melatonina en comparación con los grupos tratados con vehículo equivalente. Aunque no fue estadísticamente diferente, el diámetro del tubo endoneural fue mayor en ambos grupos de melatonina frente a los grupos de vehículo, y el efecto de la melatonina fue más pronunciado después de 21 días (aumento del 24,97 %) frente a los 7 días de tratamiento con melatonina (18,8 % de aumento). La melatonina ejerce un efecto proregenerativo dependiente del tiempo sobre las fibras nerviosas del muñón proximal y un efecto anticicatricial en ambos muñones.

Crosstalk Between Peripheral Innervation and Pancreatic Ductal Adenocarcinoma / 神经科学通报·英文版

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal malignancy, characterized by late diagnosis, aggressive growth, and therapy resistance, leading to a poor overall prognosis. Emerging evidence shows that the peripheral nerve is an important non-tumor component in the tumor microenvironment that regulates tumor growth and immune escape. The crosstalk between the neuronal system and PDAC has become a hot research topic that may provide novel mechanisms underlying tumor progression and further uncover promising therapeutic targets. In this review, we highlight the mechanisms of perineural invasion and the role of various types of tumor innervation in the progression of PDAC, summarize the potential signaling pathways modulating the neuronal-cancer interaction, and discuss the current and future therapeutic possibilities for this condition.

Study of the potential toxicity of adrenaline to neurons, using the SH-SY5Y human cellular model

Abstract Prolonged overexposure to catecholamines causes toxicity, usually credited to continuous adrenoceptor stimulation, autoxidation, and the formation of reactive pro-oxidant species. Non-differentiated SH-SY5Y cells were used to study the possible contribution of oxidative stress in adrenaline (ADR)-induced neurotoxicity, as a model to predict the toxicity of this catecholamine to peripheral nerves. Cells were exposed to several concentrations of ADR (0.1, 0.25, 0.5 and 1mM) and two cytotoxicity assays [lactate dehydrogenase (LDH) release and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction] were performed at several time-points (24, 48, and 96h). The cytotoxicity of ADR was concentration- and time-dependent in both assays, since the lowest concentration tested (0.1mM) also caused significant cytotoxicity at 96h. N-acetyl-cysteine (1mM), a precursor of glutathione synthesis, prevented ADR-induced toxicity elicited by 0.5mM and 0.25mM ADR following a 96-h exposure, while the antioxidant Tiron (100µM) was non-protective. In conclusion, ADR led to mitochondrial distress and ultimately cell death in non-differentiated SH-SY5Y cells, possibly because of ADR oxidation products. The involvement of such processes in the catecholamine-induced peripheral neuropathy requires further analysis.

Bloqueos de nervios periféricos en cirugía cesárea anestesia y analgesia, en dolor agudo y crónico / Periferal nerve blocks in cessarian secction

Cesarean section is the most frequent surgery in the world and postoperative pain is commonly reported as moderate to severe. Thus, timely multimodal analgesia, based on systemic agents and neuraxial hydrophilic opioids, is the current recommended standard. The role of peripheral nerve blocks has accumulated some evidence on this subject. The most published blocks are the transverse abdominis muscle plane blocks, the quadratus lumborum muscle plane blocks, and the most recently described, the erector spinae muscle plane block. More classic blocks, such as thoracic paravertebral or ilioinguinal-iliohypogastric nerve blocks, have limited evidence in comparison. To date, peripheral blocks neither replace nor add to the analgesic role of neuraxial opioids in cesarean surgery. However, there is room to investigate these blocks in specific scenarios. For instance, studies looking for the benefits of more lasting blocks, their role as rescue alternatives for cases still in pain after a standardized treatment, and their pertinence in patients with a high risk of severe pain becoming a chronic entity are granted. Regardless of the technique, but especially in fascial plane injections, the vulnerability to local anesthetics' systemic toxicity should be considered. Therefore, operators must follow the current guidelines for preventing and treating this complication.

La cesárea es la cirugía más frecuente en el mundo y el dolor posoperatorio en esta cirugía es comúnmente reportado con intensidad moderada a severa. Una analgesia oportuna basada en multimodalidad de agentes sistémicos y opioides hidrofílicos neuroaxiales es el estándar recomendado actual. El rol de los bloqueos regionales periféricos ha acumulado cierta evidencia hasta la fecha. Los bloqueos con más evidencia publicada son el del plano del músculo transverso abdominal, luego aquellos en relación al músculo cuadrado lumbar y por último, el más recientemente descrito del plano de los músculos erectores de la columna. Bloqueos más clásicos como el paravertebral torácico o de los nervios ilioinguinal- iliohipogástrico poseen evidencia limitada en comparación. A la fecha, ningún bloqueo regional periférico ha demostrado poder reemplazar el rol analgésico de los opioides neuroaxiales en esta cirugía, sin embargo, aún existen ventanas abiertas para investigar ciertas alternativas en escenarios puntuales, como con bloqueos que aseguren mayor duración, rescate de dolor severo posoperatorio, pacientes con mayor riesgo de dolor severo o de su cronificación. Independiente del escenario en que estos bloqueos se utilicen no se debe olvidar que es una población de particular vulnerabilidad a desarrollar cuadros de toxicidad sistémica por anestésicos locales y por lo tanto se deben considerar las medidas de prevención y tratamiento actualmente recomendadas.

Manejo de cefalea cervicogénica mediante bloqueo great occipital nerve (GON) ecoguiado en el área de urgencias. Reporte de un caso / Cervicogenic headache treated with great nerve occipital block

Cervicogenic headache can be confused with migraine headache, which conditions multiple admissions to emergency services, within the established treatments, the international headache society establishes the blockade of the greater occipital nerve (GON) with local anesthetics as necessary for the diagnosis of occipital neuralgia, with the introduction of ultrasound to perform invasive procedures, it has facilitated the performance of the technique, with excellent results, reducing stays in the emergency department and it is a technique that emergency physicians can perform.

La cefalea cervicogenica se puede confundir con cefalea migrañosa eso condiciona múltiples ingresos a los servicios de urgencias, dentro de los tratamientos establecidos, the internacional headache society establece el bloqueo del nervio occipital mayor (GON) con anestésico locales como necesario para el diagnóstico de neuralgia occipital, con la introducción del ultrasonido para realizar procedimientos invasivos ha facilitado la realización de la técnica, con excelentes resultados reduciendo las estancias en el servicio de urgencias y es una técnica que pueden realizar los médicos urgenciologos.

Tourette's Syndrome cervical dystonia induced occipital neuralgia remedied by peripheral nerve stimulation: A case report / Síndrome de Tourette, distonia cervical induzida por neuralgia occipital remediada por estimulação nervosa periférica: relato de caso

BACKGROUND: Dystonia is uncommon in Tourette's syndrome, and occipital neuralgia secondary to Tourette's dystonia is more rare, affecting quality of life. Occipital peripheral nerve stimulation (PNS) is an excellent alternative by being adjustable and minimally invasive. Our case demonstrates occipital PNS as an effective option for refractory Tourette's dystonia. CASE PRESENTATION: A thirty-four-year-old male with poorly controlled Tourette's cervical dystonia presented with severe occipital neuralgia. Various medications were prescribed including propranolol and amitriptyline, and bilateral third-occipital nerve rhizotomies and occipital nerve blocks were trialed. Distal nerve blocks at the occipital protuberance were most effective. Therefore, an occipital PNS trial was done, and a PNS was implanted with no complications. Upon follow-up, the patient reported drastic pain reduction. CONCLUSION: Our case illustrates neuromodulation benefits for a rare presentation of refractory occipital neuralgia secondary to Tourette's-related dystonia. Occipital PNS should be considered for refractory cases because it is safe, easy to implant, and effective.

FUNDAMENTO: A distonia é incomum na síndrome de Tourette, e a neuralgia occipital secundária à distonia de Tourette é mais rara, afetando a qualidade de vida. A estimulação do nervo periférico occipital (SNP) é uma excelente alternativa por ser ajustável e minimamente invasiva. Nosso caso demonstra o SNP occipital como uma opção eficaz para a distonia de Tourette refratária. APRESENTAÇÃO DO CASO: Um homem de 34 anos com distonia cervical de Tourette mal controlada apresentou neuralgia occipital grave. Vários medicamentos foram prescritos, incluindo propranolol e amitriptilina, e foram testadas rizotomias bilaterais do nervo terceiro-occipital e bloqueios do nervo occipital. Os bloqueios dos nervos distais na protuberância occipital foram mais eficazes. Portanto, foi feito um ensaio de PNS occipital e um PNS foi implantado sem complicações. Após o acompanhamento, o paciente relatou redução drástica da dor. CONCLUSÃO: Nosso caso ilustra os benefícios da neuromodulação para uma apresentação rara de neuralgia occipital refratária secundária à distonia relacionada a Tourette. O PNS occipital deve ser considerado para casos refratários porque é seguro, fácil de implantar e eficaz.

Effect of Tacrolimus and Cyclosporine Immunosuppressants on Peripheral Nerve Regeneration: Systematic Review and Meta-analysis / Efeito dos imunossupressores tacrolimus e ciclosporina na regeneração de nervos periféricos: Revisão sistemática e metanálises

Abstract Peripheral nerve damage is an important cause of seeking medical attention. It occurs when the continuity of structures is interrupted and the propagation of nervous impulses is blocked, affecting the functional capacity of individuals. To assess the effects of the immunosuppressants tacrolimus and cyclosporine on the regeneration of peripheral nerves, a systematic review of the literature was carried out. The articles included were published until September 2018 and proposed to evaluate the effects of the immunosuppressants tacrolimus and cyclosporine on nerve regeneration and neuroprotection, available in the MEDLINE, EMBASE, Cochrane Library, Web of Science, Oxford Pain Relief Database, and LILACS databases. The research analysed a total of 56 articles, of which 22 were included in the meta-analysis. Statistical analysis suggests the protective effect of tacrolimus in the regeneration of the number of myelinated axons (95% confidence interval [CI]: 0.93-2.39; p< 0.01); however, such effect was not observed in relation to cyclosporine (95%CI: - 0.38-1.18; p» 0.08) It also suggests that there is a significant relationship between the use of tacrolimus and myelin thickness (95%CI» 2.00-5.71; p< 0. 01). The use of immunosuppressants in the regeneration of peripheral nerve damage promotes an increase in the number of myelinated axons in general, regardless of the administered dose. In addition, it ensures greater myelin thickness, muscle weight and recovery of the sciatic functional index. However, heterogeneity was high in most analyses performed.

Resumo As lesões nervosas periféricas são uma causa importante de busca por atendimento médico. Elas ocorrem quando há a interrupção da continuidade das estruturas e do bloqueio da propagação dos impulsos nervosos, afetando a capacidade funcional dos indivíduos. Para avaliar os efeitos dos imunossupressores tacrolimus e ciclosporina na regeneração de nervos periféricos, foi realizada uma revisão sistemática da literatura. Foram incluídos artigos publicados até setembro de 2018, que se propunham avaliar os efeitos dos imunossupressores tacrolimus e ciclosporina na regeneração nervosa e neuroproteção, disponíveis nas bases de dados MEDLINE, EMBASE, Cochrane Library, Web of Science, Oxford Pain Relief Database e LILACS. A pesquisa analisou um total de 56 artigos, dos quais 22 foram para metanálise. A análise estatística sugere o efeito protetor do tacrolimus na regeneração do número de axônios mielinizados (intervalo de confiança [IC] 95%: 0,93-2,39; p< 0,01); todavia tal efeito não foi observado em relação à ciclosporina (IC95%: - 0,38-1,18; p» 0,08). Ela também sugere haver uma relação significativa entre o uso do tacrolimus e a espessura da mielina (IC95%: 2,00-5,71; p< 0,01). O uso de imunossupressores na regeneração de lesão nervosa periférica promove um aumento no número de axônios mielinizados de forma geral, independentemente da dose administrada. Além disso, garante uma maior espessura da mielina, um maior peso muscular e restabelecimento do índice da função do nervo ciático. Todavia, a heterogeneidade foi alta na maioria das análises realizadas.

Effect of melatonin on peripheral nerve damage resulting from tibial defect in rats / Efecto de la melatonina sobre el daño de los nervios periféricos como resultado de un defecto tibial en ratas

SUMMARY: Peripheral nerve damage (PNI) can cause demyelination, axonal degeneration and loss of motor and sensory function. Melatonin with its antioxidative effect, has been reported to reduce scar formation in nerve injury, take a role in repair process by suppressing fibroblast proliferation in the damaged area. It was aimed to investigate the effect of melatonin in the repair of peripheral nerve damage and the relationship between S100 proteins and angiogenic regulation. Wistar albino rats were divided into 3 groups. In the Defect group, 6 mm tibial bone defect using a motorized drill was created and kept immobile for 28 days. In Defect + graft group, tibial bone defect with allograft treatment was applied and kept immobile for 28 days. In Defect + graft + Melatonin group, melatonin was administered to defect + allograft group. All rats were sacrified by decapitation, skin and tibia bone were removed then fixed with 10 % neutral buffered formalin and embedded in paraffin, sections were examined under light microscopy. In the Defect+Graft group, enlargement and occlusion of the vessels with degeneration of the epineural sheath, thickening of the endoneural sheath and mild hyperplasia of schwannocytus (Schwann cells) were remarkable. In the Defect+Graft+Melatonin group, the epineural sheath was tight and regular, the axonal structures were prominent in the endoneural area. Mild S100 expression was observed in Defect+Graft group in fibers of the endoneural region with a prominent expression in schwannocytus. In Defect+Graft+Melatonin group (10mg/kg), S100 expression was moderate in areas where schwannocytus proliferated and nerve-connective tissue sheaths were reconstructed. VEGF expression was moderate in endoneural, perineural and epineural connective tissue sheaths in the Defect+Graft+Melatonin group, with negative expression in blood vessel endothelial cells, but with a positive expression in schwannocytus. We conclude that with the application of melatonin; oxidative stress decreases, schwannocytus proliferation increases, having positive influence on nerve repair with the regulation of S100 signaling and angiogenetic structuring.

RESUMEN: El daño a los nervios periféricos puede causar desmielinización, degeneración axonal y pérdida de la función motora y sensorial. Se ha informado que la melatonina, con su efecto antioxidante, reduce la formación de cicatrices en lesiones nerviosas y desempeña un papel en el proceso de reparación al suprimir la proliferación de fibroblastos en el área dañada. El objetivo de este trabajo fue investigar el efecto de la melatonina en la reparación del daño de los nervios periféricos y la relación entre las proteínas S100 y la regulación angiogénica. Ratas albinas Wistar se dividieron en 3 grupos. En el grupo Defecto, se creó un defecto óseo tibial de 6 mm con un taladro motorizado y se mantuvo inmóvil durante 28 días. En el grupo Defecto + injerto, se aplicó tratamiento de defecto óseo tibial con aloinjerto y se mantuvo inmóvil durante 28 días. En el grupo Defecto + injerto + Melatonina, se administró melatonina al grupo defecto + aloinjerto. Todas las ratas fueron sacrificadas por decapitación, se extrajo la piel y el hueso de la tibia y luego se fijaron con formalina tamponada neutra al 10 % y se incluyeron en parafina, las secciones se examinaron bajo microscopía óptica. En el grupo Defecto+Injerto, fueron notables el agrandamiento y la oclusión de los vasos con degeneración de la vaina epineural, engrosamiento de la vaina endoneural e hiperplasia leve de los schwannocitos (neurolemnocitos). En el grupo Defecto+Injerto+Melatonina, la vaina epineural era estrecha y regular, las estructuras axonales eran prominentes en el área endoneural. Se observó expresión leve de S100 en el grupo Defecto+Injerto en fibras de la región endoneural con una expresión prominente en los schwannocitos. En el grupo Defecto+Injerto+Melatonina, la expresión de S100 fue moderada en áreas donde proliferaron los schwannocitos y se reconstruyeron las vainas de tejido conectivo nervioso. La expresión de VEGF fue moderada en vainas de tejido conectivo endoneural, perineural y epineural en el grupo Defecto+Injerto+Melatonina, con expresión negativa en células endoteliales de vasos sanguíneos, pero con expresión positiva en schwannocitos. Concluimos que con la aplicación de melatonina; disminuye el estrés oxidativo, aumenta la proliferación de schwannocitos, influyendo positivamente en la reparación nerviosa con la regulación de la señalización S100 y la estructuración angiogenética.

Dolor de rebote en anestesia regional: Una revisión narrativa / Rebound pain in regional anesthesia: A narrative review Abstract

OBJECTIVES: To describe the phenomenon of rebound pain associated with peripheral nerve blocks in the setting of trauma and orthopedic surgery, to know its characteristics, pathophysiological mechanisms, risk factors, preventive and treatment measures. METHODOLOGY: Non-systematic bibliographic review of articles in English, in medical databases PubMed, Google Scholar, Embase, Epistemonikos and Cochrane library in January 2021, restricting the search to articles published in the last five years. A total of 58 articles related to rebound pain in the context of orthopedic and trauma surgery were identified according to the inclusion and exclusion criteria. RESULTS: It was evidenced that there is still no consensus on its definition, although it presents repeated characteristics, such as acute and transitory pain, which occurs after the resolution of the peripheral nerve block. An incidence of up to 50% is described in the outpatient setting, but there is no data outside this setting. Its pathophysiology is complex and not yet fully understood, however, a peripheral sensitization component could determine a higher incidence of the phenomenon. Recognized risk factors correspond to trauma and orthopedic surgeries of the upper limb with dense peripheral nerve blocks and young female patients. In relation to its prevention, dexamethasone and dexmedetomidine stand out as promising adjuvants that together with a multimodal analgesia scheme can mitigate its appearance. CONCLUSIONS: Understanding the impact of rebound pain, its characteristics, risk factors, preventive measures and benefits of multimodal analgesia, is part of a comprehensive clinical practice to avoid the negative consequences of increased use of health resources, as well as to reduce the consumption of opioids and their known adverse effects.

OBJETIVOS : Describir el fenómeno de dolor de rebote asociado a bloqueos de nervio periférico en el entorno de cirugía traumatoló- gica y ortopédica, conocer sus características, mecanismos fisiopatológicos, factores de riesgo, medidas preventivas y de tratamiento. METODOLOGÍA: Revisión bibliográfica no sistemática de artículos en inglés, en bases de datos médicas PubMed, GoogleScholar, Embase, Epistemonikos y Cochrane library en enero del 2021, restringiéndose la búsqueda a los artículos publicados en los últimos cinco años. Se identificaron un total de 67 artículos relacionados a dolor de rebote en contexto de cirugía ortopédica y traumatológica según los criterios de inclusión y exclusión. RESULTADOS: Se evidenció que aún no existe un consenso en su definición, no obstante presenta características reiteradas, como ser un dolor agudo y transitorio, que ocurre posterior a la resolución del bloqueo de nervio periférico. Se describe una incidencia en el ámbito ambulatorio de hasta 50%, pero sin datos fuera de este entorno. Su fisiopatología es compleja y todavía no se comprende en su totalidad, sin embargo, un componente de sensibilización periférica podría determinar una mayor incidencia del fenómeno. Factores de riesgo reconocidos corresponden a cirugías traumatológicas y ortopédicas de miembro superior con bloqueos de nervio periférico densos y pacientes jóvenes de sexo femenino. En relación a su prevención destacan dexametasona y dexmedetomidina como adyuvantes prometedores que junto a un esquema de analgesia multimodal pueden mitigar su aparición. CONCLUSIONES: Entender el impacto del dolor de rebote, sus características, factores de riesgo, medidas preventivas y beneficios de la analgesia multimodal, forma parte de una práctica clínica integral para evitar las consecuencias negativas de una mayor utilización de recursos sanitarios, como también reducir el consumo de opioides y de sus efectos adversos conocidos

The Effect of Anakinra on Acrylamide-induced Peripheral Neuropathy and Neuropathic Pain in Rats

Abstract Acrylamide is a neurotoxic compound. Moreover, anakinra is an interleukin-1 (IL-1) receptor antagonist used in rheumatoid arthritis treatment. This study investigated the effect of anakinra on acrylamide-related neuropathy and neuropathic pain. Acrylamide exposure caused a significant decrease in the pain threshold; an increase in malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1ß) levels; and a decrease in total glutathione (tGSH) values in the sciatic nerve. This indicates hyperalgesia presence, oxidative stress, and peripheral nerve tissue inflammation. Anakinra treatment significantly reduced the MDA, IL-1ß, and TNF-α levels, and increased the pain threshold and mean tGSH values. The analgesic effect of anakinra was 67.9% at the first hour, increasing to 74.9% and 76.7% at the second and third hours, respectively. The group receiving acrylamide exhibited histopathological changes (e.g., swollen and degenerated axons, hypertrophic and hyperplasic Schwann cells, and congested vessels). The use of anakinra significantly improved these morphological changes. Anakinra is concluded to reduce neuropathic pain and prevent neurotoxic effect of acrylamide on peripheral nerves due to its analgesic, antioxidant, and anti-inflammatory properties

Comparison of two volumes for sciatic perineural injection using 1% methylene blue in rabbit cadavers / [Comparação de dois volumes para injeção perineural no nervo isquiático utilizando azul de metileno 1% em cadáveres de coelhos]

The purpose of this study was to assess the efficacy of a blind technique for sciatic and femoral nerve block in rabbit cadavers by evaluating the spread of 1% methylene blue at two different volumes. Nine recently euthanized rabbits weighing 2.5(0.3kg were used. The sciatic (SN) and femoral (FN) nerves of each limb were randomly assigned for injection with 1% methylene blue at 0.2mL/kg (G0.2) or 0.3mL/kg (G0.3). Nerves were dissected and measured for depth and extension of staining (cm). Mean comparisons were performed using paired t test. The relation between volume and nerve staining ( 2cm was assessed using chi-square test. The mean depth of SN was 1.9±0.2 and 1.6±0.3cm and staining 1.9±1.4 and 2.0±1.2cm, respectively in G0.2 and G0.3. No relation was found between depth and dye spread and there was no association between nerve staining ( 2.0cm and volume of solution. The FN failed to be stained in all subjects. In conclusion, SN injection can be successfully performed without guidance in rabbits. The lower volume (0.2mL/kg) is recommended to avoid systemic toxicity.(AU)

O objetivo deste estudo foi avaliar a eficácia de uma técnica para bloqueio às cegas dos nervos isquiático e femoral em cadáveres de coelhos, por meio da avaliação da dispersão de azul de metileno 1% em dois volumes distintos. Nove coelhos recém-eutanasiados, com peso 2,5(0,3kg, foram utilizados. Os nervos isquiático (NI) e femoral (NF) de cada membro foram aleatoriamente designados para injeção com azul de metileno 1% a 0,2mL/kg (G0,2) ou 0,3mL/kg (G0,3). Em seguida, foram dissecados e mensurados em relação à sua profundidade e extensão corada (cm). As médias foram comparadas por meio de teste t pareado. A relação entre volume e extensão corada ( 2cm foi avaliada utilizando-se teste de qui-quadrado. A profundidade média do NI foi 1,9±0,2 e 1,6±0,3cm, e a extensão corada 1,9±1,4 e 2,0±1,2cm, respectivamente, no G0,2 e no G0,3. Não houve relação entre a profundidade e a extensão corada ou entre a extensão corada ( 2,0cm e o volume de solução. Não foi observada coloração do NF em nenhum cadáver. Concluiu-se que a injeção do NI pode ser realizada com sucesso sem auxílio de tecnologias em coelhos. O menor volume (0,2mL/kg) é recomendado para evitar toxicidade sistêmica.(AU)

Nervio interóseo posterior: origen, localización y trayecto nervioso: una revisión / Posterior interosseous nerve: origin, location and nerve path: a review

RESUMEN: El nervio interóseo posterior (NIP) ha sido utilizado como sinónimo ocontinuación inmediata del ramo profundo del nervio radial (RPNR) al emerger en el compartimiento posterior del antebrazo. Su origen tampoco es claro, describiéndose como nervio interóseo posterior a su trayecto proximal, intermedio o distal al músculo supinador. El objetivo de esta revisión es detallar la visión de diversos autores respecto al origen y trayecto del NIP, proponiendo una correcta terminología para estas estructuras. Se realizó una revisión bibliográfica de varios textos y de algunos artículos utilizados para la enseñanza de la anatomía humana, publicados entre los años 1800 y la actualidad. En la búsqueda, se determinaron criterios de inclusión que consideraban, anatomía humana, escritos en español, francés o inglés y que aludieran al NIP. Tras la exploración inicial se localizaron 18 libros, procedentes de Francia, Rusia, España, Argentina, Estados Unidos, Canadá, Reino Unido, Alemania, India y México. Una descripción del NIP más precisa, en cuanto al origen, trayecto y función, es aquella postulada por la vertiente francesa, correspondiendo a un origen terminal del ramo profundo del nervio radial, luego de emitir sus ramos musculares. Este delgado nervio transcurre adosado a la membrana interósea para luego avanzar por el cuarto compartimiento extensor, distribuyéndose en las articulaciones dorsales del carpo a quienes inerva sensitiva y propioceptivamente.

SUMMARY: The posterior interosseous nerve (PIN) has been used as a synonym or immediate continuation of the deep branch of the radial nerve as it emerges in the posterior compartment of the forearm. Its origin is not clear either, being described as a posterior interosseous nerve to its proximal, intermediate or distal path to the supinator muscle. The objective of this review is to detail the vision of various authors regarding the origin and path of the PIN, proposing a correct terminology for these structures. A bibliographic review of several texts and some articles used for the teaching of human anatomy, published between the 1800s and the present day, was carried out. In the search, inclusion criteria were determined that considered human anatomy, written in Spanish, French or English and that alluded to the PIN. After the initial exploration, 18 books were located, coming from France, Russia, Spain, Argentina, the United States, Canada, the United Kingdom, Germany, India and Mexico. A more precise description of the PIN, in terms of origin, path and function, is that postulated by the French literature, corresponding to a terminal origin of the deep branch of the radial nerve, after emitting its muscular branches. This thin nerve runs attached to the interosseous membrane to then advance through the fourth extensor compartment, distributing itself in the dorsal carpal joints to which it innervates sensitively and proprioceptively.

Clinical, electrophysiological, and ultrasound evaluation for early detection of musculoskeletal hand disorders and nerve entrapment in mobile phone users

ABSTRACT Introduction: Smartphone overuse may lead to musculoskeletal manifestations, such as carpal tunnel syndrome (CTS) and arthritis of hand joints, with an increased median nerve cross-sectional area (CSA). Objective: The aim of this study is the early detection of musculoskeletal hand disorders using ultrasound techniques, and to detect nerve entrapment using clinical evaluation, ultrasound, and electrophysiological studies, in university employees younger than 35 years using mobile phones. Function is assessed using the Michigan Hand Outcomes Questionnaire (MHQ). Materials and methods: Cross-sectional controlled study included 74 smartphone users classified into two groups according to a smartphone addiction scale (SAS), into high and low smart phone users, with 35 non-smartphone users with matched age and gender as a control group. A clinical assessment of nerve entrapment symptoms was performed, and the Michigan Hand Outcomes Questionnaire (MHQ), with a total score from 0 to100, was used to assess hand function. Electrodiagnostic studies of median and ulnar nerves were used to detect early nerve entrapment. Bilateral ultrasound was performed in order to assess the median nerve CSA and involvement of thumb and small hand joints. The data collected were analyzed using the SPSS program version 20. Results: CSAs of median nerves were significantly higher in the dominant hand of high smartphone users than in low and non-smartphone users (p < 0.001). There was a significant positive correlation between CSA and SAS (r = 0.45), visual analogue scale (VAS) (r = 0.61), and duration of smartphone use (r = 0.80), with negative correlation with MHQ (r = -0.63). Significant differences in were found in the electrophysiological studies of median and ulnar nerves. The mean ultrasound score for both hands was higher in the high smartphone users compared to low smartphone users (15.08 ± 4.17 vs. 6.46 ± 1.38, p < .001). Conclusions: There is increased median nerve CSAs among high smartphone users associated with prolongation of both sensory and motor latencies and slow conduction velocities. Caution should be exercised when using mobile phones, in order to minimize the risk of developing hand musculoskeletal disorders.

Accuracy of sonographic identification of suprascapular nerve at supraclavicular fossa: a cadaveric study / Precisión de la identificación ecográfica del nervio supraescapular en la fosa supraclavicular: un estudio cadavérico

SUMMARY: Sonographic identification of suprascapular nerve (SSN) is essential for diagnosis of suprascapular neuropathy and ultrasound-guided suprascapular nerve block. This study aims to demonstrate the accuracy of identification of SSN at supraclavicular region by ultrasonography in fresh cadavers. Ninety-three posterior cervical triangles were examined. With ultrasonography, SSN emerging from the upper trunk of brachial plexus was identified and followed until it passed underneath the inferior belly of omohyoid muscle. Sonographic visualization of SSN in supraclavicular fossa was recorded. Then, cadaveric dissection was performed to determine the presence or absence of SSN. An agreement between sonographic identification and direct visualization was specified and categorized the following three patterns: "correctly identified" (pattern I), "incorrectly identified" (pattern II), and "unidentified" (pattern III). The identification of SSN using sonography was correct in almost 90 %. The diameter of SSN with pattern I was the largest compared to those of other two patterns. In pattern I, SSN ran laterally from the upper trunk of brachial plexus and passed underneath the inferior belly of omohyoid muscle. Therefore, SSN was easily identified under ultrasonography. In pattern II, nerve identified by ultrasonography was literally the dorsal scapular nerve. In pattern III, SSN was unable to be identified because of its anatomical variation. The accuracy of ultrasonographic identification of SSN at supraclavicular fossa is high and the key sonoanatomical landmarks are the lateral margin of brachial plexus and the inferior belly of omohyoid muscle. The anatomical variants of SSN are reasons of incorrect or unable identification of SSN under ultrasonography.

RESUMEN: La identificación ecográfica del nervio supraescapular (NSE) es esencial para el diagnóstico de neuropatía supraescapular y bloqueo del nervio supraescapular mediante la ecografía. Este estudio tiene como objetivo demostrar la precisión de la identificación de NSE en la región supraclavicular por ecografía en cadáveres frescos. Se examinaron noventa y tres triángulos cervicales posteriores. Se identificó el NSE emergente de la parte superior del tronco del plexo braquial con la ecografía, y se siguió hasta su trayecto por debajo del vientre inferior del músculo omohioideo. Se registró la visualización ecográfica del NSE en la fosa supraclavicular. Luego, se realizó disección cadavérica para determinar la presencia o ausencia de NSE. Se especificó un acuerdo entre la identificación ecográfica y la visualización directa y se categorizaron los siguientes tres patrones: "identificado correctamente" (patrón I), "identificado incorrectamente" (patrón II) y "no identificado" (patrón III). La identificación de NSE mediante ecografía fue correcta en casi el 90 %. El diámetro del NSE con el patrón I fue el más grande en comparación con los de los otros dos patrones. En el patrón I, NSE corría lateralmente desde la parte superior del tronco del plexo braquial y pasaba por debajo del vientre inferior del músculo omohioideo. Por lo tanto, el NSE se identificó fácilmente mediante ecografía. En el patrón II, el nervio identificado por ecografía era literalmente el nervio escapular dorsal; en el patrón III, el NSE no pudo ser identificado debido a su variación anatómica. La precisión de la identificación ecográfica del NSE en la fosa supraclavicular es alta y los puntos de referencia sonoanatómicos clave son el borde lateral del plexo braquial y el vientre inferior del músculo omohioideo. Las variantes anatómicas de NSE son razones de identificación incorrecta o incapaz de NSE bajo ecografía.