The Role and Mechanism of Aspirin Combined with Rehabilitation Training in the Repair of Sciatic Nerve Injury and the Changes in the Schwannocytus (Schwann Cells) in Rats / Rol y Mecanismo de la Aspirina Combinados con Entrenamiento de Rehabilitación en la Reparación de la Lesión del Nervio Ciático y los Cambios en los Schwannocitos (Células de Schwann) en Ratas

SUMMARY: This study investigated the role and mechanism of aspirin combined with rehabilitation training in the nerve injury repair and Schwann cell changes in rats with sciatic nerve injury. Totally, 120 male healthy SD rats were randomly divided into sham, model, aspirin, and aspirin + rehabilitation groups, with 30 rats in each group. The sciatic nerve function index (SFI), photothermal pain tolerance threshold and inclined plane test results at 4, 6, and 8 weeks after operation were compared. The distance of sensory nerve regeneration and the expression of S100B protein in Schwann cells were analyzed. Compared with the sham group, the SFI of the model, aspirin, and aspirin+rehabilitation groups were significantly lower at 4, 6, and 8 weeks after operation. However, the aspirin and aspirin+rehabilitation groups had significantly higher SFI than the model group. The SFI at 6 and 8 weeks after operation was higher in the aspirin+rehabilitation group than that in the aspirin group (P<0.05). The photothermal pain tolerance threshold of the sham, aspirin, and aspirin+rehabilitation groups were significantly higher than those of the model group at 4, 6, and 8 weeks after operation (P<0.05). The inclination angles of the model, aspirin, and aspirin+rehabilitation groups were significantly lower than those of the sham group at 4, 6, and 8 weeks after operation, and the inclination angle of the aspirin+rehabilitation group was significantly higher than that of the model and aspirin groups (P<0.05). The sensory nerve regeneration distance in aspirin and aspirin+rehabilitation groups was higher than that in the sham and model groups (P<0.05). The expression of S100B protein in the aspirin and aspirin+rehabilitation groups was higher than that in the model group (P<0.05). Aspirin combined with rehabilitation training can promote the functional recovery of sciatic nerve injury, and the mechanism may be related to the increase of the expression of S100B protein in Schwann cells.

En este estudio se investigó el papel y el mecanismo que desempeña la aspirina combinada, con el entrenamiento de rehabilitación en la reparación de lesiones nerviosas y los cambios en los schwannocitos en ratas con lesiones en el nervio ciático. En total, 120 ratas SD macho sanas se dividieron aleatoriamente en cuatro grupos de 30 ratas en cada uno: simulación, modelo, aspirina y aspirina + rehabilitación. Se compararon el índice de función del nervio ciático (SFI), el umbral de tolerancia al dolor fototérmico y los resultados de la prueba del plano inclinado a las 4, 6 y 8 semanas después de la operación. Se analizó la distancia de regeneración del nervio sensorial y la expresión de la proteína S100B en los schwannocitos. En comparación con el grupo simulado, el SFI de los grupos modelo, aspirina y aspirina+rehabilitación fue significativamente menor a las 4, 6 y 8 semanas después de la operación. Sin embargo, los grupos de aspirina y aspirina + rehabilitación tuvieron un SFI significativamente más alto que el grupo modelo. El SFI a las 6 y 8 semanas después de la operación fue mayor en el grupo de aspirina + rehabilitación que en el grupo de aspirina (P<0,05). El umbral de tolerancia al dolor fototérmico de los grupos simulado, aspirina y aspirina+rehabilitación fue significativamente mayor que el del grupo modelo a las 4, 6 y 8 semanas después de la operación (P<0,05). Los ángulos de inclinación de los grupos modelo, aspirina y aspirina+rehabilitación fueron significativamente menores que los del grupo simulado a las 4, 6 y 8 semanas después de la operación, y el ángulo de inclinación del grupo aspirina+rehabilitación fue significativamente mayor que el de los grupos modelo y aspirina (P<0.05). La distancia de regeneración del nervio sensorial en los grupos de aspirina y aspirina+rehabilitación fue mayor que en los grupos simulado y modelo (P<0,05). La expresión de la proteína S100B en los grupos de aspirina y aspirina+rehabilitación fue mayor que en el grupo modelo (P<0,05). La aspirina combinada con el entrenamiento de rehabilitación puede promover la recuperación funcional de la lesión del nervio ciático, y el mecanismo puede estar relacionado con el aumento de la expresión de la proteína S100B en los schwannocitos.

Investigation of the Neuro-Regenerative Effects of Bioresonance and Magnetotherapy in Sciatic Nerve Damage-Induced Rats / Investigación de los Efectos Neurorregenerativos de Biorresonancia y Magnetoterapia en Ratas Inducidas por Daño del Nervio Ciático

SUMMARY: Peripheral nerve damage is a significant clinical problem that can lead to severe complications in patients. Regarding the regeneration of peripheral nerves, it is crucial to use experimental animals' nerves and use different evaluation methods. Epineural or perineural suturing is the gold standard in treating sciatic nerve injury, but nerve repair is often unsuccessful. This study aimed to investigate the neuroregenerative effects of magnetotherapy and bioresonance in experimental animals with sciatic nerve damage. In this study, 24 female Wistar rats were divided into 7 groups (n=6) as follows: Group 1 (Control), Group 2 (Axonotmesis control), Group 3 (Anastomosis control), Group 4 (Axonotmesis + magnetotherapy), Group 5 (Anastomosis + magnetotherapy), Group 6 (Axonotmesis + bioresonance), Group 7 (Anastomosis + bioresonance). Magnetotherapy and bioresonance treatments were applied for 12 weeks. Behavioural tests and EMG tests were performed at the end of the 12th week. Then the rats were sacrificed, and a histopathological evaluation was made. The statistical significance level was taken as 5 % in the calculations, and the SPSS (IBM SPSS for Windows, ver.21) statistical package program was used for the calculations. Statistically significant results were obtained in animal behaviour tests, EMG, and pathology groups treated with magnetotherapy. There was no statistically significant difference in the groups treated with bioresonance treatment compared to the control groups. Muscle activity and nerve repair occurred in experimental animals with acute peripheral nerve damage due to 12 weeks of magnetotherapy, and further studies should support these results.

El daño a los nervios periféricos es un problema clínico importante que puede conducir a complicaciones graves en los pacientes. En cuanto a la regeneración de los nervios periféricos, es crucial utilizar los nervios de los animales de experimentación y diferentes métodos de evaluación. La sutura epineural o perineural es el gold estándar en el tratamiento de lesiones del nervio ciático, pero la reparación del nervio a menudo no tiene éxito. Este estudio tuvo como objetivo investigar los efectos neuroregenerativos de la magnetoterapia y la biorresonancia en animales de experimentación con daño del nervio ciático. En el estudio, 24 ratas hembras Wistar se dividieron en 7 grupos (n=6) de la siguiente manera: Grupo 1 (Control), Grupo 2 (Control de axonotmesis), Grupo 3 (Control de anastomosis), Grupo 4 (Axonotmesis + magnetoterapia), Grupo 5 (Anastomosis + magnetoterapia), Grupo 6 (Axonotmesis + biorresonancia), Grupo 7 (Anastomosis + biorresonancia). Se aplicaron durante 12 semanas tratamientos de magnetoterapia y biorresonancia. Las pruebas de comportamiento y las pruebas de EMG se realizaron al final de la semana 12. Luego se sacrificaron las ratas y se realizó una evaluación histopatológica. El nivel de significación estadística se tomó como 5 % en los cálculos, y se utilizó el programa de paquete estadístico SPSS (IBM SPSS para Windows, ver.21). Se obtuvieron resultados estadísticamente significativos en pruebas de comportamiento animal, EMG y grupos de patología tratados con magnetoterapia. No hubo diferencia estadísticamente significativa en los grupos con tratamiento de biorresonancia en comparación con los grupos controles. La actividad muscular y la reparación nerviosa, se produjeron en animales de experimentación con daño nervioso periférico agudo, debido a 12 semanas de magnetoterapia.Estudios adicionales deberían respaldar estos resultados.

A study of high division of sciatic nerve in human cadavers and its clinical significance

Background: Sciatic nerve is a mixed nerve which provide sensory and motor supply for skin and muscles of the lower limb by tibial and common peroneal nerve. Anatomical variations of sciatic nerve at high division have been reported by various authors. The path of the sciatic nerve is important while administration of intramuscular injection to prevent nerve injury and nerve blockage failure during anesthesia. This knowledge of high division helps in different surgical approach for sciatic nerve injury or hip dislocation. Aims and Objectives: The aim of the study was to describe incidences of high division variation of Sciatic nerve and different types in cadavers during routine dissection schedule. Materials and Methods: The study was conducted during routine dissection schedule in anatomy department for first MBBS students to observe sciatic nerve course in 30 gluteal regions from 15 adult cadavers fixed by formalin. Location of sciatic nerve in relation to piriformis muscle and its division whether in single nerve sheath or separate sheath and types was recorded. Results: In 12 cadavers (80%), sciatic nerve course found normal which leaves pelvis at inferior border of piriformis muscle and bifurcate in terminal branches tibial nerve and common peroneal nerve as it approaches at the apex of popliteal fossa. In 3 cadavers (20%), two male and one female, we found high division of sciatic nerve where terminal branches, tibial nerve, and common peroneal nerve leave the pelvis below piriformis separately in different sheaths. Conclusion: Knowledge of variations-related high division of sciatic nerve would help surgeons during different interventions related to sciatic nerve and for preventing further complications.

Comparison of the Nerve Regeneration Capacity and Characteristics between Sciatic Nerve Crush and Transection Injury Models in Rats / 生物医学与环境科学（英文）

OBJECTIVE@#To provide useful information for selecting the most appropriate peripheral nerve injury model for different research purposes in nerve injury and repair studies, and to compare nerve regeneration capacity and characteristics between them.@*METHODS@#Sixty adult SD rats were randomly divided into two groups and underwent crush injury alone (group A, n = 30) or transection injury followed by surgical repair (group B, n = 30) of the right hind paw. Each group was subjected to the CatWalk test, gastrocnemius muscle evaluation, pain threshold measurement, electrophysiological examination, retrograde neuronal labeling, and quantification of nerve regeneration before and 7, 14, 21, and 28 days after injury.@*RESULTS@#Gait analysis showed that the recovery speed in group A was significantly faster than that in group B at 14 days. At 21 days, the compound muscle action potential of the gastrocnemius muscle in group A was significantly higher than that in group B, and the number of labeled motor neurons in group B was lower than that in group A. The number of new myelin sheaths and the g-ratio were higher in group A than in group B. There was a 7-day time difference in the regeneration rate between the two injury groups.@*CONCLUSION@#The regeneration of nerve fibers was rapid after crush nerve injury, whereas the transection injury was relatively slow, which provides some ideas for the selection of clinical research models.

Sciatic nerve derived exosomes in promotion of axon regeneration and functional recovery following peripheral nerve injury in rat / 中华显微外科杂志

Objective:To explore the effect of sciatic nerve derived exosomes(SN-EXO) on axon regeneration and functional recovery after peripheral nerve injury(PNI).Methods:From March 2021 to October 2022, the Department of Orthopedics of the First Affiliated Hospital of Zhengzhou University studied the effect of SN-EXO on the proliferation of Schwann cells(SCs) through EdU cell proliferation experiment. Twenty-one healthy male SD rats were randomly divided into 3 groups of sham operation, peripheral nerve injury(PNI) and SN-EXO treatment, with 7 rats in each group. The right sciatic nerves of rat models in sham group were exposed without injury. In the rat in PNI group and SN-EXO treatment group, PBS and SN-EXO were injected under the epineurium of right sciatic nerves following sciatic nerve crush. Sciatic nerve function index(SFI) was performed at 28 days after operation, and then sacrificed. Right sciatic nerves were removed for further exploration of nerve regeneration. The histopathological changes and axon arrangement of sciatic nerves were evaluated by HE staining. Regeneration efficiency of neurofilaments and SCs were obserred by NF200 and S100β double staining of sciatic nerve. The data obtained were statistically analyzed, and P<0.05 was statistically significant. Results:It was found that SN-EXO can significantly enhance the proliferation ability of SCs, with statistically significant difference( P<0.05). SFI in SN-EXO treatment group and PNI group were(-27.65±4.36) and(-57.33±7.49), respectively, and the difference was statistically significant( P<0.05). Axons in SN-EXO treatment group were arranged more closely and orderly than those in the PNI group at 28 days after operation, and there were less injury induced axon disintegration and vacuolation. Immunofluorescence assay indicated that NF200 and S100β fluorescence intensity in SN-EXO treatment group was significantly higher than that in the PNI group, and the difference was statistically significant( P<0.05). Conclusion:SN-EXO could enhance the proliferation of SCs to promote axon regeneration following peripheral nerve injury.

An enriched environment can promote nerve regeneration in a mouse model of sciatic nerve compression / 中华物理医学与康复杂志

Objective:To document any effect of environmental enrichment on nerve regeneration in a mouse model of sciatic nerve compression and explore its mechanism.Methods:A crushed sciatic nerve model was successfully established in 22 C57BL/6 mice, and they were then randomly divided into an intervention group and a control group. The mice of the intervention group were raised in a cage with an enriched environment, while those of the control group were kept in a standard cage. Two weeks later, both groups′ gait was analyzed and the compound muscle action potential (CMAP) of the sciatic nerve was measured. The proportion of myelinated sciatic nerve fibers was examined using toluidine blue staining, and the expression of myelin basic protein (MBP), growth associated protein-43 (GAP43) and p75 neurotrophin receptor (p75 NTR) was measured using immunofluorescence intensity. Results:①The latency of the CMAP [(1.05±0.04)ms] was significantly shortened in the intervention group compared with the control group and the amplitude was significantly higher. ②Gait analysis showed a significant increase in the average contact intensity, stride length and stride rate of the intervention group compared with the control group. However, the step axis angle of the intervention group was significantly smaller than in the control group on average. ③The stained nerve fibers in the intervention group were orderly and dense, and the average number of myelinated fibers was significantly greater than in the control group. ④Quantitative analysis of the immunofluorescence showed that the levels of MBP, GAP43 and p75 NTR in the sciatic nerves of the intervention group were, on average, significantly higher than in the control group. Conclusion:An enriched environmental can promote the regeneration and functional recovery of crushed sciatic nerves by promoting the proliferation and myelination of Schwann cells.

A Cadaveric Based Morphometric Analysis of the Sciatic Nerve with Clinical Implications

Background: The sciatic nerve is one of the very vital nerves of the body, which has importance not only in the field of Anatomy but also in various clinical fields such as Orthopaedics, Anaesthesia, Plastic & Reconstructive Surgery, and Neurosurgery. This study was the first attempt to analyze the different dimensions of the anatomically normal sciatic nerves at different levels, involving Malaysian cadavers.Material & Methods:The study was conducted on 78 adult, both cadaveric and disarticulated lower limb specimens belonging to both genders. The morphometric analysis was done in 64 specimens having anatomically normal sciatic nerves. The dimensions were measured by a digital Vernier caliper, a measuring tape, and thread.Results:The average width, thickness and circumference of the nerve at the lower border of piriformis muscle (PM) were 15.86 mm ± 1.47 (right) & 16.56 mm ± 1.08 (left); 4.22 mm ± 0.29 (right) & 4.10 mm ± 0.20 (left) and 27.70 mm ± 2.02 (right) & 27.72 mm ± 2.39 (left), respectively. Similarly, at the level between ischial tuberosity (IT) and greater trochanter (GT), the mean width was 11.59 mm ± 1.43 (right) & 11.50 mm ± 1.53 (left); thickness was 3.48 mm ± 0.18 (right) & 3.35 mm ± 0.17 (left) and circumference was 27.08 mm ± 2.79 (right) & 27.22 mm ± 2.87 (left). At bifurcation, the mean width was 8.66 mm ± 0.65 (right) & 8.90 mm ± 0.81 (left); thickness was 2.41 mm ± 0.12 (right) & 2.31 mm ± 0.15 (left) and circumference was 19.75 mm ± 1.44 (right) & 19.99 mm ± 1.45 (left). The average distance between IT and GT was 50.37 mm ± 4.47 (right) & 47.73 mm ± 4.24 (left); between lateral border of IT and medial border of sciatic nerve was 15.43 mm ± 1.45 (right) & 14.66 mm ± 1.37 (left); and between medial border of GT and lateral border of the nerve was 27.13 mm ± 1.38 (right) & 25.07 mm ± 1.73 (left). The average length of the nerve was 328.20 ± 26.26 (right) & 332.31 ± 21.89 (left); and that of the thigh was 412.19 ± 24.50 (right) & 407.24 ± 25.82 (left).Conclusion: This knowledge will not only aid future researchers but also will assist surgeons, orthopaedicians, anaesthetists, reconstructive surgeons, and neurosurgeons by preventing iatrogenic nerve injuries.

Fotobiomodulação com LED induz melhora na funcionalidade da marcha em ratos após lesão nervosa periférica / Photobiomodulation with LED increased the gait functionality in rats submitted to peripheral nerve injury

Introdução: As lesões nervosas periféricas (LNP) podem resultar em distúrbios motores e sensoriais alterando a funcionalidade do membro afetado, porém pouco se conhece a respeito dos efeitos da fotobiomodulação (FBM) com diodo emissor de luz (LED). Objetivo: Analisar os efeitos do LED sobre a funcionalidade da marcha de ratos Wistar pós LNP. Metodologia: Ratos Wistar foram submetidos a LNP por esmagamento de ciático e analisados nos seguintes grupos experimentais: (1) Controle; (2) LNP; (3) LNP+ LED (780 nm, potência média 40 mW, exposição radiante, energia por ponto, 3,2 J sobre o nervo ciático (LEDn); (4) LNP+ LED em nervo e região do músculo envolvido (LEDnm) e (5) LNP+ LED apenas em região do músculo (LEDm). Após 7, 14, 21 e 28 dias foram realizadas as análises de marcha utilizando o Índice Funcional Ciático (IFC). Resultado: Após 7 dias, os grupos tratados com LED apresentaram uma melhora da marcha em relação ao grupo Lesão, sendo essa melhora mais pronunciada no grupo LEDn. Após 14 dias, os grupos LEDn e LEDnm apresentaram valores semelhantes ao grupo controle e após 21 e 28 dias o IFC não apresentou diferenças entre os grupos experimentais. Conclusão: O LED aumentou a funcionalidade da marcha avaliada pelo IFC após 1 e 2 semanas pós LNP, especialmente quando foi usado na região nervosa associada ou não à região muscular.

Introduction: Peripheral nerve injuries (PNI) can result in motor and sensory disturbances altering the functionality of the affected limb, however not much is known about the effects of photobiomodulation (PBM) with light emitting diode (LED). Objective: We aimed to analyze the effects of LED on the gait function of Wistar rats after PNI. Methodology: Wistar rats were submitted to PNI by sciatic crush and analyzed in the following experimental groups: (1) Control; (2) PNI; (3) PNI+ LED (780 nm, mean power 40 mW, radiant exposure, energy per spot, 3.2 J on the sciatic nerve) (LEDn); (4) LNP+ LED on nerve and involved muscle region (LEDnm) and (5) LNP+ LED only on muscle region (LEDm). After 7-, 14-, 21- and 28-days gait analyses were performed using the Sciatic Functional Index (SFI). Results: After 7 days, the groups treated with LED showed an improvement in gait compared to the PNI group, with this improvement being more pronounced in the LEDn group. After 14 days, the LEDn and LEDnm groups showed similar values to the control group and after 21 and 28 days the SFI did not show differences between the experimental groups. Conclusion: LED increased the gait functionality evaluated by SFI after 1 and 2 weeks post-PNI, especially when it was used in the nerve region associated or not with the muscle region.

Regional anesthesia for compartment syndrome as a complication of ECMO. Case report / Anestesia regional para síndrome compartimental como complicación de ECMO. Reporte de caso

Abstract We present the case of a patient intervened for mechanical mitral replacement, tricuspid annuloplasty, and correction of a total anomalous pulmonary venous return, which required Extracorporeal Membrane Oxygenation (ECMO) in the immediate postoperative period because of refractory cardiogenic shock. After withdrawal of the arterial cannula, the patient developed compartment syndrome of the right lower limb, requiring urgent intervention. Also, the patient went into respiratory failure, requiring support with high flow oxygen cannula. Given the patient's condition, general anesthesia was discarded. An ultrasound-guided popliteal block and sedation with dexmedetomidine and ketamine was performed instead, maintaining the high flow nasal cannula. Regional anesthesia along with dexmedetomidine and ketamine could be an alternative for a surgical procedure in patients with high risk of cardiovascular and respiratory complications.

Resumen Presentamos el caso de una paciente femenina sometida a remplazo de válvula mitral mecánica, anuloplastia y corrección de retorno venoso pulmonar anómalo total, quien requirió oxigenación con membrana extracorpórea (ECMO) en el postoperatorio inmediato debido a shock cardiogénico refractario. Una vez retirada la cánula arterial, la paciente desarrolló síndrome compartimental de la extremidad inferior derecha, requiriendo intervención urgente. Adicionalmente, presentó insuficiencia respiratoria que requirió soporte de oxígeno por cánula de alto flujo. En vista de la condición de la paciente se descartó la anestesia general, optando a cambio por un bloqueo poplíteo guiado por ultrasonido más sedación con dexmedetomidina y ketamina, manteniendo la cánula nasal de alto flujo. La anestesia regional junto con dexmedetomidina y ketamina puede ser una alternativa para procedimientos quirúrgicos en pacientes de alto riesgo cardiovascular y complicaciones respiratorias.

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

Comparative study of cold hyperalgesia and mechanical allodynia in two animal models of neuropathic pain: different etiologies and distinct pathophysiological mechanisms

Abstract Neuropathic pain (NP) affects more than 8% of the global population. The proposed action of the transient receptor potential ankyrin 1 (TRPA1) as a mechanosensor and the characterization of the transient receptor potential melastatin 8 (TRPM8) as a cold thermosensor raises the question of whether these receptors are implicated in NP. Our study aimed to evaluate the involvement of TRPA1 and TRPM8 in cold and mechanical signal transduction to obtain a comparative view in rat models of streptozotocin-induced diabetes (STZ) and chronic constriction injury of the sciatic nerve (CCI). The electronic von Frey test showed that STZ rats presented mechanical allodynia that was first evidenced on the 14th day after diabetes confirmation, and four days after CCI. This phenomenon was reduced by the intraplantar (ipl) administration of a TRPA1 receptor antagonist (HC-030031; 40 µL/300 µg/paw) in both NP models. Only CCI rats displayed cold hyperalgesia based on the cold plate test. The pharmacological blocking of TRPA1 through the injection of the antagonist attenuated cold hyperalgesia in this NP model. STZ animals showed a reduction in the number of flinches induced by the intraplantar injection of mustard oil (MO; TRPA1 agonist; 0.1%/50 µL/paw), or intraplantar injection of menthol (MT; TRPM8 agonist; 0.5% and 1%/50 µL/paw). The response induced by the ipl administration of MT (1%/50 µL/paw) was significantly different between the CCI and SHAM groups. Together, these data suggest a different pattern in nociceptive behavior associated with different models of NP, suggesting a variant involvement of TRPA1 and TRPM8 in both conditions

Alleviation of neuropathic pain by trazodone in rats

Abstract Neuropathic pain is generally characterised by an abnormal sensation (dysesthesia), an increased response to painful stimuli (hyperalgesia), and pain in response to a stimulus that does not normally provoke pain (allodynia). The present study was designed to investigate the effect of trazodone (5mg/kg and 10mg/kg) on peripheral neuropathic pain induced by partial sciatic nerve ligation in rats. Mechanical hyperalgesia, cold allodynia and thermal hyperalgesia were assessed by performing the pinprick, acetone, and hot plate tests, respectively. Biochemically, lipid peroxidation level and total calcium levels were measured. However, trazodone administration (5 and 10 mg/ kg i.p.) for 21days significantly diminished partial sciatic nerve ligation-induced neuropathic pain along with areduction in oxidative stress and calcium levels. The results of the present study suggest that trazodone is effective in attenuating partial sciatic nerve ligation-inducedpainful neuropathic states, which may be attributed to decreased oxidative stress and calcium levels.

Síndrome do piriforme: diagnóstico e tratamento: um estudo retrospectivo / Piriformis syndrome: diagnosis and treatment: a retrospective study

Introdução: A síndrome do piriforme (SP) é uma causa de dor ciática pouco entendida e conhecida, por isso, subdiagnosticada. Possui múltiplas possibilidades etiológicas e a abordagem terapêutica corrente privilegia o tratamento conservador. Objetivo: Neste estudo retrospectivo são destacados o diagnóstico, a etiologia, o diagnóstico diferencial e analisados os resultados do tratamento instituído. Métodos: 34 casos com seguimento mínimo de seis meses e máximo de 12 meses avaliados por uma escala simplificada de graduação de sintomas. Resultados: O tratamento clínico-conservador obteve excelentes resultados em 23 pacientes (67,6%), bom em nove pacientes (26,4%) e razoáveis (insatisfatórios) em dois pacientes (5,8%). Conclusões: Na dor com característica ciática, contínua ou intermitente e sem evidências de compressão radicular ou herniação discal lombar, deve-se pesquisar a possibilidade de síndrome do piriforme como um diagnóstico eminentemente clínico e de exclusão. O tratamento conservador apresenta resultados satisfatórios na maioria dos casos e a indicação cirúrgica está reservada como último recurso às falhas da terapia conservadora.

Introduction: Piriformis syndrome is a cause of sciatalgy barely understood and frequently unrecognized. It has multiple possible etiologic factors and the treatment of option is largely conservative. Objective: In this retrospective study, the diagnostic signs, the ethiology, the diferential diagnosis and the treatment results are discussed. Methods: 34 patients were followed-up for 6-12 months and evaluated by a simplified symptom rating scale. Results: Excellent results in 23 patients (67,6%), good in 9 patients (26,4%) and fair (unsatisfactory) in 2 patients (5,8%). Conclusions: In patients with sciatic pain without proved rachidian or discal lumbar disease, the possibility of Piriformis Syndrome must be investigated mainly by proper clinical examination and seen as a diagnosis of exclusion. The conservative treatment has satisfactory outcomes in most of cases and surgical procedure is reserved as a last resort in case of failure of the conservative management.

Effect of dexmedetomidine on blood concentrations of ropivacaine during sciatic nerve block in rabbits / 中华麻醉学杂志

Objective:To evaluate the effect of dexmedetomidine on the blood concentrations of ropivacaine during sciatic nerve block in rabbits.Methods:Twelve New Zealand rabbits of both sexes, weighing 2-3 kg, were randomly divided into ropivacaine group (R group) and ropivacaine mixed with dexmedetomidine group (RD group). The right femoral vein was cannulated for blood sampling in both groups, 0.375% ropivacaine 3 ml was injected around the left sciatic nerve in group R, and 0.375% ropivacaine 3 ml containing 1.5 μg/kg dexmedetomidine was injected instead in group RD.Blood samples from the right femoral vein were collected before nerve block (T 0) and at 15, 30, 45, 60, 120 and 180 min after nerve block (T 1-6) for determination of plasma concentrations of ropivacaine using high-performance liquid chromatography after centrifugation, and concentration-time curves were plotted. Results:Compared with group R, the blood concentrations of ropivacaine were significantly decreased at T 1-3 ( P<0.05), no significant change was found in the blood concentrations of ropivacaine at T 4-6 ( P>0.05), the peak blood concentration of ropivacaine was significantly decreased ( P<0.01), and no significant change was found in the time to peak blood concentrations of ropivacaine or area under the concentration-time curves in group RD ( P>0.05). Conclusions:Dexmedetomidine can decrease the blood concentrations of ropivacaine during sciatic nerve block in rabbits.

Local vibration therapy promotes the recovery of nerve function in rats with sciatic nerve injury / 中西医结合学报

OBJECTIVE@#It has been reported that local vibration therapy can benefit recovery after peripheral nerve injury, but the optimized parameters and effective mechanism were unclear. In the present study, we investigated the effect of local vibration therapy of different amplitudes on the recovery of nerve function in rats with sciatic nerve injury (SNI).@*METHODS@#Adult male Sprague-Dawley rats were subjected to SNI and then randomly divided into 5 groups: sham group, SNI group, SNI + A-1 mm group, SNI + A-2 mm group, and SNI + A-4 mm group (A refers to the amplitude; n = 10 per group). Starting on the 7th day after model initiation, local vibration therapy was given for 21 consecutive days with a frequency of 10 Hz and an amplitude of 1, 2 or 4 mm for 5 min. The sciatic function index (SFI) was assessed before surgery and on the 7th, 14th, 21st and 28th days after surgery. Tissues were harvested on the 28th day after surgery for morphological, immunofluorescence and Western blot analysis.@*RESULTS@#Compared with the SNI group, on the 28th day after surgery, the SFIs of the treatment groups were increased; the difference in the SNI + A-2 mm group was the most obvious (95% confidence interval [CI]: [5.86, 27.09], P < 0.001), and the cross-sectional areas of myocytes in all of the treatment groups were improved. The G-ratios in the SNI + A-1 mm group and SNI + A-2 mm group were reduced significantly (95% CI: [-0.12, -0.02], P = 0.007; 95% CI: [-0.15, -0.06], P < 0.001). In addition, the expressions of S100 and nerve growth factor proteins in the treatment groups were increased; the phosphorylation expressions of ERK1/2 protein in the SNI + A-2 mm group and SNI + A-4 mm group were upregulated (95% CI: [0.03, 0.96], P = 0.038; 95% CI: [0.01, 0.94], P = 0.047, respectively), and the phosphorylation expression of Akt in the SNI + A-1 mm group was upregulated (95% CI: [0.11, 2.07], P = 0.031).@*CONCLUSION@#Local vibration therapy, especially with medium amplitude, was able to promote the recovery of nerve function in rats with SNI; this result was linked to the proliferation of Schwann cells and the activation of the ERK1/2 and Akt signaling pathways.

Lesión del nervio ciático mayor por proyectil de escopeta / Lesion of the major sciatic nerve due to a shotgun projectile

Se describe el caso clínico de un paciente de 26 años de edad, atendido en la consulta de Ortopedia y Traumatología del Centro de Diagnóstico Integral Salvador Allende de Caracas, en la República Bolivariana de Venezuela, quien desde hacía 6 meses había recibido un disparo de escopeta en la cara posterior de ambos muslos. Esta vez acudió a consulta con dolor intenso en el miembro inferior izquierdo, sobre todo por debajo de la rodilla, acompañado de parestesias en la zona de inervación de ambas ramas de bifurcación del nervio ciático. Se pudo comprobar que el joven presentaba múltiples impactos de proyectiles en la cara posterior de ambos muslos y marcha claudicante. Los estudios radiográficos confirmaron la presencia de 8 proyectiles, 2 en el muslo derecho y 6 en el izquierdo. En la vista lateral se observó que uno de ellos se encontraba a una profundidad que se correspondía con la región anatómica del nervio ciático izquierdo. Para la intervención quirúrgica se utilizó anestesia local, sedación y un intensificador de imágenes. Con la cooperación del paciente se pudo extraer el proyectil alojado en el epineuro del ciático sin complicaciones. A los 3 meses habían desaparecido las molestias y pudo reincorporarse a sus actividades habituales.

The case report of a 26 years patient is described. He was assisted in the Orthopedics and Traumatology Service of Salvador Allende Integral Diagnostic Center from Caracas, in the Bolivian Republic of Venezuela who had received a shotgun shot in the posterior face of both thighs 6 months ago. This time he went to visit the doctor with intense pain in the left inferior member, mainly below the knee, accompanied by paresthesias in the innervation area of both bifurcation branches of the sciatic nerve. It could be demonstrated that the young man presented multiple projectile impacts in the posterior face of both thighs and hesitating gait. The radiographic studies confirmed the presence of 8 projectiles, two in the right thigh and 6 in the left one. In the lateral view it was observed that one of them was at a depth that matched with the anatomical region of the left sciatic nerve. Local anesthesia, sedation and an images intensifier were used for the operation. The projectile located in the epineurium of the sciatic nerve could be removed with the patient cooperation without complications. After 3 months the discomfort had disappeared and he could return to his usual activities.

Morphometric study of rat sciatic nerve recovery after three nerve repair techniques: epineural suture, polyethylene glycol hydrogel and fibrin sealant / Estudio morfométrico de la recuperación del nervio ciático de rata después de tres técnicas de reparación nerviosa: sutura epineural, hidrogel de polietilenglicol y sellante de fibrina

SUMMARY: The effectiveness of microsurgical technique has a direct impact on the recovery of the injured peripheral nerve. The aim of our study was to investigate the result of sciatic nerve regeneration in rats after complete neurotomy and after nerve repair techniques including: 1) epineural suture; 2) polyethylene glycol hydrogel (PEG) (DuraSeal); 3) fibrin sealant (Tisseel). The cross-section of distal sciatic nerve was studied at 14th, 30th and 60th days after nerve repair. Morphometry of myelinated nerve fibers in the distal stump of the sciatic nerve was performed. A significant increase in the number of myelinated nerve fibers was found, especially between 14 and 30 days. The density of myelinated nerve fibers in the distal stump at day 60 was significantly higher after using nerve repair technique including PEG and fibrin versus epineural suture (29.2 % and 32.1 % versus 21.5 %, P <0.05), and a higher level of remyelination of nerve fibers observed in the group with PEG. On day 60, complete elimination of PEG and fibrin sealant was not observed, encapsulation was found around the clusters of hydrogel. Thereby, three peripheral nerve repair techniques were equally effective, only with the use of PEG remyelination of nerve fibers was increasing.

RESUMEN: La efectividad de la técnica microquirúrgica tiene un impacto directo en la recuperación del nervio periférico lesionado. El objetivo de nuestro estudio fue investigar el resultado de la regeneración del nervio ciático en ratas después de una neurotomía completa y después de técnicas de reparación nerviosa que incluyeron: 1) sutura epineural; 2) hidrogel de polietilenglicol (PEG) (DuraSeal); 3) sellante de fibrina (Tisseel). La sección transversal del nervio ciático distal se estudió a los 14, 30 y 60 días después de la reparación del nervio. Se realizó la morfometría de fibras nerviosas mielinizadas en el muñón distal del nervio ciático. Se observó un aumento significativo en el número de fibras nerviosas mielinizadas, especialmente entre los 14 y 30 días. La densidad de las fibras nerviosas mielinizadas en el muñón distal en el día 60 fue significativamente mayor después de usar una técnica de reparación nerviosa que incluye PEG y fibrina en comparación con la sutura epineural (29,2 % y 32,1 % versus 21,5 %, P <0,05), y un mayor nivel de remielinización del nervio en fibras observadas en el grupo con PEG. El día 60, no se observó la eliminación completa de PEG y sellador de fibrina, se encontró encapsulación alrededor de los grupos de hidrogel. Por lo tanto, tres técnicas de reparación de nervios periféricos fueron igualmente efectivas, solo que aumentaba la remielinización de fibras nerviosas con PEG.

Neurofibroma plexiforme gigante del nervio ciático en una adulta burkinesa / Giant plexiform neurofibroma of the sciatic nerve in a Burkinabé adult

Se presenta el caso de una paciente de 36 años de edad con antecedente patológico de enfermedad de Von Reklinghausen, quien fue asistida en el Servicio de Cirugía General del Centro Hospitalario de Kossodô en Burkina Faso por presentar un tumor gigante en la región posterior del muslo derecho. Los exámenes complementarios confirmaron el presunto diagnóstico de neurofibroma plexiforme gigante del nervio ciático. Durante el procedimiento quirúrgico se extirpó un tumor infrecuente cuyo peso excedió los 22,5 kg. Con el tratamiento rehabilitador posoperatorio del miembro operado la paciente evolucionó satisfactoriamente y se le dio el alta hospitalaria 7 días después.

The case report of a 36 years patient with pathological history of Von Reklinghausen disease is presented. She was assisted in the General Surgery Service of the Hospital Center from Kossodô in Burkina Faso presenting a giant tumor in the back region of the right thigh. The complementary exams confirmed the presumed diagnosis of giant plexiform neurofibroma of the sciatic nerve. During the surgical procedure an uncommon tumor was removed which weight exceeded the 22.5 kg. With the postoperative rehabilitative treatment of the operated member the patient had a favorable clinical course and she was discharged from the hospital 7 days later.

Anatomic landmarks for a safe arthroscopic approach to the deep gluteal space: a cadaveric study / Hitos anatómicos para un abordaje artroscópico seguro del espacio glúteo profundo: un estudio cadavérico

SUMMARY: To determine the morphometric landmarks and anatomical variants relevant to the arthroscopic approach to the deep gluteal space. Twenty deep gluteal spaces from cadaveric specimens were dissected. The anatomical variants of the sciatic nerve (SN) were determined according to the Beaton and Anson classification. A morphometric study of the distances in the subgluteal space was carried out to define the anatomical references to achieve a safe arthroscopic approach for piriformis syndrome [GT-SN=Distance from greater trochanter (GT) to SN emergence; GT-IT=Distance from GT to ischial tuberosity (IT); GT-IGA=distance from GT to inferior gluteal artery (IGA) emergence; IT-SN=distance from IT to SN emergence; IT-IGA=distance from IT to IGA]. The SN showed the most frequent anatomical pattern with an undivided nerve coming out of the pelvis below the piriformis muscle (Beaton type A) in 16 specimens (80 %). The common peroneal nerve emergence in the subgluteal space through the piriformis muscle (PM) with the tibial nerve being located at the lower margin of the piriformis muscle (Beaton type B) was observed in 4 specimens (20 %). The morphometric measurements of the surgical area of study were: GT-SN=7.23 cm (±8.3); GT-IT=8.56 cm (±0.1); GT-IGA=8.46 cm (±0.97); IT-SN=5.28 cm (±0.73), IT- IGA=5.47 cm (±0.74). When planning surgery for the deep gluteal syndrome in adult patients, the fact that the emergence of the SN in the subgluteal space is approximately 7 cm from the greater trochanter and 5 cm from the ischial tuberosity must be considered.

RESUMEN: El objetivo del estudio fue determinar referentes morfométricos y variantes anatómicas relevantes en el abordaje artroscópico del espació subglúteo. Se disecaron veinte regiones glúteas procedentes de cadáver. Las variaciones anatómicas del nervio ciático (SN) se determinaron de acuerdo con la clasificación de Beaton y Anson. Se llevó a cabo un estudio morfométrico de distancias en el espacio subglúteo, con objeto de determinar referencias que permitan un abordaje artroscópico seguro del sindrome piriforme [GT-SN= distancia trocánter mayor (GT) a la emergencia del nervio ciático (SN); GT-IT= distancia GT a la tuberosidad isquiática (IT); GT-IGA= distancia GT a la emergen- cia de la arteria glútea inferior (IGA); IT-SN= distancia IT a la emergencia del SN; IT-IGA= distancia IT a la IGA]. El patrón más frecuente del SN fue su emergencia no dividida por el margen inferior del músculo piriforme (tipo A Beaton) en 16 especímenes (80 %). La salida del nervio fibular común a través del músculo piriforme (PM) con el nervio tibial localizado en el margen inferior del PM (tipo B Beaton) se observó en 4 especímenes (20 %). Las medidas en el área quirúrgica de estudio fueron: GT-SN= 7,23 cm ± 8,3; GT-IT= 8,56 cm ± 0,1; GT-IGA= 8,46 cm ± 0,97; IT-SN= 5,28 cm ± 0,73 IT-IGA= 5,47 cm ± 0,74. En la cirugía del síndrome glúteo profundo en adultos, debe considerarse que la sa- lida del SN hacia el espacio subglúteo tiene lugar aproximadamente a 7 cm del GT y a 5 cm de la IT.

Endometriosis con infiltración aislada del nervio ciático, una forma de presentación atípica: reporte de un caso clínico / Isolated infiltrative endometriosis of the sciatic nerve, an atypical presentation: clinical case report

INTRODUCCIÓN: La endometriosis afecta hasta un 10-15% de las mujeres jóvenes. Se define como tejido endometrial funcional fuera de la cavidad uterina y su presentación clásica es la dismenorrea. La variedad profunda afecta a un 1-2% y las localizaciones más frecuentes son el peritoneo pélvico, ovarios, ligamentos útero-sacros y septum recto-vaginal; sin embargo, puede presentarse de forma muy infrecuente como implantes aislados localizados en relación al nervio ciático. El diagnóstico habitualmente es complejo y tardío, dado que los síntomas son inespecíficos y el examen físico puede ser indistinguible de otras etiologías. El estudio imagenológico de elección para la endometriosis profunda es la resonancia magnética (RM) de pelvis ya que una adecuada localización pre-quirúrgica de las lesiones es fundamental. CASO CLÍNICO: Paciente de sexo femenino de 46 años, con tres años de dolor pélvico, dismenorrea y dispareunia. El síntoma cardinal fue dolor ciático progresivo, con déficit motor y alteraciones sensitivas, los cuales se exacerbaban durante la menstruación y no presentaban respuesta al tratamiento farmacológico. En la RM se identifica nódulo sólido sospechoso de endometriosis en relación al nervio ciático derecho. El caso es evaluado por un comité multidisciplinario y se realiza cirugía laparoscópica. El diagnóstico de sospecha es confirmado histológicamente. La paciente presenta buena recuperación post-quirúrgica y cese completo de los síntomas descritos. DISCUSIÓN: La endometriosis profunda presenta un reto diagnóstico y habitualmente es tardío. Este caso presenta el resultado exitoso de una buena sospecha clínica, un estudio imagenológico completo y la resolución con una técnica quirúrgica compleja.

INTRODUCTION: Endometriosis is a disease that affects 10-15% of young women. It is characterized as functional endometrial tissue outside the uterine cavity. The most common form of presentation is dysmenorrhea. Deep endometriosis affects 1-2% of the patients, and is frequently located in the pelvic peritoneum, ovaries, utero-sacral ligaments and recto-vaginal septum. The isolated endometriosis of the sciatic nerve is a very uncommon presentation of this disease. Late diagnosis is frequent, mainly because the symptoms are non-specific, and the physical examination may be indistinguishable from other etiologies. The imaging study of choice is the pelvic magnetic resonance imaging (MRI) and an accurate pre-surgical location of the lesions is critical for a successful surgical outcome. CLINICAL CASE: 46-year-old female patient with 3 years of pelvic pain, dysmenorrhea and dyspareunia. The cardinal symptom was progressive sciatic pain, with motor deficit and sensory alterations. The pain was persistent despite pharmacological treatment and exacerbated during menstruation. MRI identifies a nodule located in the pelvic portion of the right sciatic nerve, suggestive of an endometriosis implant. The case was discussed by a multidisciplinary committee and laparoscopic surgery was performed. The diagnosis was confirmed with histology. The patient recovered well from surgery with significant improvement of the previously described symptoms. DISCUSSION: The diagnosis of deep endometriosis is challenging and usually delayed. This rare disease had a successful outcome, due to an early clinical suspicion, a thorough imaging study and an effective resolution with a complex surgical technique.