ABSTRACT
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.
Subject(s)
Animals , Rats , Sciatic Nerve/cytology , Exercise , Aspirin/therapeutic use , Sciatic Neuropathy/rehabilitation , Schwann Cells , Immunohistochemistry , Pain Threshold , Combined Modality Therapy , Sciatic Neuropathy/physiopathology , Disease Models, AnimalABSTRACT
Resumen: Introducción: La neuropatía ciática es una entidad infrecuente y de difícil diagnóstico en Pediatría. Su evolución a largo plazo no ha sido claramente definida. Objetivo: Analizar la presentación clínica y evolución de un grupo de niños con neuropatía ciática. Pacientes y Método: Análisis retrospectivo de las características clínicas de pacientes pediátricos con neuropatía ciática atendidos en 2 hospitales de Santiago, entre 2014-2018. Se evaluó examen motor, trofismo muscular, reflejos osteotendíneos, marcha, sensibilidad y dolor. Se estudió neuroconducción de nervio ciático, electromiografía (EMG) y en 3 pacientes, Resonancia Magnética (RM). Resultados: Se incluyeron 6 pacientes, edad promedio 11,8 años. Hubo 2 causas traumáticas, 2 compresivas, 1 vascular y 1 tumoral. Los 6 pa cientes debutaron con pie caído e hiporreflexia/arreflexia aquiliana; 5 pacientes presentaron dolor neuropático severo. La EMG mostró en todos los casos compromiso en nervios y musculatura de pendientes del nervio ciático. En 2 casos se realizó RM de cintura pélvica y extremidades inferiores, mostrando compromiso muscular selectivo en pierna en territorio ciático. En 1 caso, se realizó RM de plexo lumbosacro, y luego estudio histológico, que concluyeron un tumor neural benigno. En los 3 pacientes que tuvieron seguimiento mayor a un año, se observaron secuelas motoras, con marcha alterada. Conclusión: La neuropatía ciática en este grupo fue secundaria a diversas etiologías, predominando las traumático-compresivas. En los 3 casos que tuvieron seguimiento a largo plazo se observaron secuelas motoras significativas. En la mayoría la lesión se asoció a causas prevenibles como accidentes y posicionamiento en niños con compromiso de conciencia, lo que resulta fundamental en la prevención de una patología con alto grado de secuelas.
Abstract: Introduction: Sciatic neuropathy is rare and difficult to diagnose in pediatrics, and its long-term course has not been completely understood. Objective: To analyze the clinical presentation and evolution of a group of pediatric patients with sciatic neuropathy. Patients and Method: Retrospective anal ysis of the clinical characteristics of pediatric patients with sciatic neuropathy treated in two hospitals of Santiago between 2014 and 2018. Locomotor examination, muscle trophism, deep tendon reflexes, gait, sensation, and pain were assessed. Sciatic nerve conduction study and electromyography (EMG) were performed, and magnetic resonance imaging (MRI) in three patients. Results: Six patients were included with an average age of 11.8 years. The etiologies were traumatic (N = 2), by compression (N = 2), vascular (N = 1), and tumor (N = 1). All of the 6 patients presented foot drop and Achilles tendon hyporeflexia/areflexia, and 5 patients presented severe neuropathic pain. The EMG showed involvement of the sciatic nerve rami and dependent muscles. In two patients, a pelvic girdle and lower limbs MRI was performed, showing selective muscle involvement in sciatic territory. One patient underwent a lumbosacral plexus MRI, and subsequently histological study showing a benign neural tumor. Out of the three patients who were followed-up longer than one year presented motor sequelae and gait disorder. Conclusion: Sciatic neuropathy in the study group was secondary to different causes, predominantly traumatic and compressive etiologies. The three patients that were ina long-term follow-up presented significant motor sequelae. In most of the cases, neural injury wasassoci- ated with preventable causes, such as accidents and positioning in unconscious children, which is crucial in the prevention of a pathology with a high sequelae degree.
Subject(s)
Humans , Female , Child, Preschool , Child , Adolescent , Sciatic Neuropathy/diagnosis , Prognosis , Magnetic Resonance Imaging , Retrospective Studies , Risk Factors , Follow-Up Studies , Sciatic Neuropathy/etiology , Sciatic Neuropathy/physiopathology , Sciatic Neuropathy/therapy , ElectromyographyABSTRACT
Abstract Purpose To investigate the effects of Chemically Extracted Acellular Nerves (CEANs) when combined with Adipose-Derived mesenchymal Stem Cell (ADSC) transplantation on the repair of sciatic nerve defects in rabbits. Methods A total of 71 six-month-old Japanese rabbit were used in this study. Twenty rabbits served as sciatic nerve donors, while the other 51 rabbits were randomly divided into Autologous Nerve Transplantation Group (ANT, n=17), CEAN group (n=17) and CEAN-ADSCs group (n=17). In all these groups, the rabbit's left sciatic nerves were injured before the experiment, and the uninjured sciatic nerves on their right side were used as the control (CON). Electrophysiological tests were carried out and sciatic nerves were prepared for histomorphology and stretch testing at 24 weeks post-transplant. Results There were significant differences between ANT and Con groups in amplitude (AMP): P=0.031; motor nerve conduction velocity (MNCV): P=0.029; Maximum stress: P=0.029; and Maximum strain P=0.027. There were also differences between the CEAN and CEAN+ADSCs groups in AMP: P=0.026, MNCV: P=0.024; Maximum stress: P=0.025 and Maximum strain: P=0.030. No significant differences in these parameters were observed when comparing the ANT and CEAN+SACN groups (MNCV: P=0.071) or the CEAN and ANT groups (Maximum stress: P=0.069; Maximum strain P=0.077). Conclusion Addition of ADSCs has a significant impact on the recovery of nerve function, morphology, and tensile mechanical properties following sciatic nerve injury.
Subject(s)
Animals , Male , Sciatic Neuropathy/surgery , Sciatic Neuropathy/physiopathology , Mesenchymal Stem Cell Transplantation/methods , Mesenchymal Stem Cells , Nerve Tissue/transplantation , Rabbits , Reference Values , Sciatic Nerve/surgery , Sciatic Nerve/physiopathology , Biomechanical Phenomena , Reproducibility of Results , Treatment Outcome , Electromyography , Nerve Regeneration/physiology , Nerve Tissue/surgeryABSTRACT
ABSTRACT Objective: To evaluate the effects of right sciatic nerve compression and cryotherapy on muscle tissue. Methods: We used 42 male Wistar rats, subdivided in the following Groups Control, Injury 3, Injury 8 and Injury 15 submitted to nerve compression and euthanized in the 3rd, 8th and 15th day after surgery. The Cryotherapy Injury 3 was entailed treatment with cryotherapy by immersion of the animal in recipient for 20 minutes during 1 day, then animals were euthanized at the 3rd day after surgery, and the Cryotherapy Injury 8 and the Cryotherapy Injury 15 was treated for 6 days, and euthanized at the 8th and 15th day after surgery. Functional evaluation was performed by the grasping strength of the right pelvic limb. The right tibialis anterior muscles were evaluated for mass, smaller diameter and cross-sectional area. In the Cryotherapy Injury 8 and the Cryotherapy Injury 15 groups, the hydroxyproline was dosed in the right soles. Results: In the compression there was a significant difference in the Injury Groups compared with the Control Group (p<0.05). In the smaller diameter, the compression in Control Group was higher than Injury 8 (p=0.0094), Injury 15 (p=0.002) and Cryotherapy Injury 15 (p<0.001) groups. The comparison between groups with euthanasia in the same post-operative period, a significant difference (p=0.0363) was seen in day 8th after surgery, and this result in Cryotherapy Injury Group was greater than Injury Group. In the fiber area, Control Group was also higher than the Injury 8 (p=0.0018), the Injury 15 (p<0.001) and the Cryotherapy Injury 15 (p<0.001). In hydroxyproline, no significant difference was seen between groups. Conclusion: Nerve damage resulted in decreased muscle strength and trophism, the cryotherapy delayed hypotrophy, but this effect did not persist after cessation of treatment.
RESUMO Objetivo: Avaliar os efeitos da compressão nervosa do isquiático direito e da crioterapia no tecido muscular. Métodos: Foram utilizados 42 ratos Wistar machos, subdivididos nos Grupos Controle, Lesão 3, Lesão 8 e Lesão 15, submetidos a compressão nervosa e eutanasiados, respectivamente, no 3°, 8° e 15° dias pós-operatório; Lesão Crioterapia 3, tratado com crioterapia, por imersão durante 20 minutos, por 1 dia, e eutanasiados no 3° dia pós-operatório; e Lesão Crioterapia 8 e Lesão Crioterapia 15, tratados durante 6 dias e eutanasiados no 8° e 15° dias pós-operatório. A avaliação funcional foi realizada pela força de preensão do membro pélvico direito. Os músculos tibiais anteriores direitos foram avaliados quanto a massa, menor diâmetro e área de secção transversa. Em Lesão Crioterapia 8 e Lesão Crioterapia 15, foi dosada a hidroxiprolina nos sóleos direitos. Resultados: Na preensão, houve diferença significativa nos Grupos Lesão quando comparados ao Grupo Controle (p<0,05). No menor diâmetro, o Grupo Controle foi maior que Lesão 8 (p=0,0094), Lesão 15 (p = 0,002) e Lesão Crioterapia 15 (p<0,001). Na comparação entre os grupos com eutanásia no mesmo pós-operatório, houve diferença significativa (p=0,0363) no 8° pós-operatório, sendo Lesão Crioterapia maior que Lesão. Na área das fibras, o Grupo Controle também foi maior que Lesão 8 (p=0,0018), Lesão 15 (p<0,001) e Lesão Crioterapia 15 (p<0,001). Na hidroxiprolina, não houve diferença significativa entre os grupos. Conclusão: A lesão nervosa resultou na diminuição da força e em trofismo muscular, e a crioterapia retardou a hipotrofia, porém este efeito não se manteve após o tratamento cessar.
Subject(s)
Animals , Male , Sciatic Nerve/pathology , Cryotherapy/methods , Sciatic Neuropathy/pathology , Sciatic Neuropathy/therapy , Nerve Compression Syndromes/pathology , Nerve Compression Syndromes/therapy , Reference Values , Sciatic Nerve/surgery , Sciatic Nerve/physiopathology , Time Factors , Random Allocation , Reproducibility of Results , Treatment Outcome , Rats, Wistar , Muscle Weakness/physiopathology , Sciatic Neuropathy/physiopathology , Disease Models, Animal , Hypertrophy/physiopathology , Nerve Compression Syndromes/physiopathologyABSTRACT
ABSTRACT Objective To evaluate the effect of jumping in aquatic environment on nociception and in the soleus muscle of trained and not trained Wistar rats, in the treatment of compressive neuropathy of the sciatic nerve. Methods Twenty-five Wistar rats were distributed into five groups: Control, Lesion, Trained + Lesion, Lesion + Exercise, and Trained + Lesion + Exercise. The training was jumping exercise in water environment for 20 days prior to injury, and treatment after the injury. Nociception was evaluated in two occasions, before injury and seven after injury. On the last day of the experiment, the right soleus muscles were collected, processed and analyzed as to morphology and morphometry. Results In the assessment of nociception in the injury site, the Control Group had higher average than the rest, and the Lesion Group was larger than the Trained + Lesion and Lesion + Exercise Groups. The Control Group showed higher nociceptive threshold in paw, compared to the others. In the morphometric analysis, in relation to Control Group, all the injured groups showed decreased muscle fiber area, and in the Lesion Group was lower than in the Lesion + Exercise Group and Trained + Lesion Group. Considering the diameter of the muscle fiber, the Control Group had a higher average than the Trained + Lesion Group and the Trained + Lesion + Exercise Group; and the Lesion Group showed an average lower than the Trained + Lesion and Lesion + Exercise Groups. Conclusion Resistance exercise produced increased nociception. When performed prior or after nerve damage, it proved effective in avoiding hypotrophy. The combination of the two protocols led to decrease in diameter and area of the muscle fiber.
RESUMO Objetivo Avaliar os efeitos do salto em meio aquático, na nocicepção e no músculo sóleo, em ratos Wistar treinados e não treinados, no tratamento de neuropatia compressiva do nervo isquiático. Métodos Foram distribuídos em cinco grupos 25 ratos Wistar: Controle, Lesão, Treinado + Lesão, Lesão + Exercício e Treinado + Lesão + Exercício. O treino foi com exercício de salto em meio aquático durante 20 dias, prévio à lesão, e o tratamento ocorreu após a lesão. Foram realizadas avaliações da nocicepção, sendo uma pré-lesão e sete pós-lesão. No último dia de experimento, os músculos sóleos direitos foram coletados, processados e analisados por meio de morfologia e morfometria. Resultados Na avaliação da nocicepção no local da lesão, o Grupo Controle apresentou média maior que os demais, e o Grupo Lesão foi maior que os Grupos Treinado + Lesão e Lesão + Exercício. O Grupo Controle apresentou limiar nociceptivo na pata maior com relação aos demais. Nas análises morfométricas, em relação ao Grupo Controle, todos os grupos lesionados apresentaram diminuição da área da fibra muscular; o Grupo Lesão apresentou-se menor que os Grupos Treinado + Lesão e Lesão + Exercício. No diâmetro da fibra muscular, o Grupo Controle apresentou média maior que os Grupos Treinado + Lesão e Treinado + Lesão + Exercício, e o Grupo Lesão apresentou média menor que os Grupos Treinado + Lesão e Lesão + Exercício. Conclusão O exercício físico resistido produziu aumento da nocicepção. Quando realizado previamente ou após a lesão nervosa, mostrou-se eficaz em evitar a hipotrofia. A associação dos dois protocolos levou à diminuição do diâmetro e da área da fibra muscular.
Subject(s)
Animals , Male , Muscle, Skeletal/physiopathology , Sciatic Neuropathy/physiopathology , Sciatic Neuropathy/therapy , Nociception/physiology , Hydrotherapy/methods , Nerve Compression Syndromes/physiopathology , Nerve Compression Syndromes/therapy , Physical Conditioning, Animal/physiology , Reference Values , Time Factors , Random Allocation , Reproducibility of Results , Treatment Outcome , Rats, WistarABSTRACT
JUSTIFICATIVA E OBJETIVOS: A dor neuropática é uma condição frequente e desafiadora no que concerne ao tratamento, necessitando assim do uso de modelos experimentais para a melhor compreensão de seus mecanismos. O objetivo deste estudo foi reproduzir cirurgicamente o modelo de constrição crônica do nervo ciático e quantificar os comportamentos auto-dirigidos sugestivos de dor neuropática crônica experimental durante quatro semanas.MÉTODO: Foram utilizados 21 ratos Wistar divididos em três grupos: normal (n = 7), pseudo-cirúrgico (n = 7) e cirúrgico (n = 7). No grupo pseudo-cirúrgico, procedeu-se apenas a exposição bilateral do nervo ciático, sem lesioná-los. No grupo cirúrgico procedeu-se a exposição do nervo ciático à direita e então constrição com fio mononylon 4.0 em quatro locais, separados por 2 mm de distância. No membro esquerdo, fez-se apenas exposição do nervo ciático, sem lesioná-lo. RESULTADOS: A análise dos comportamentos revelou um aumento significativo (p < 0,05) de coçar-se e morder-se nos membros posteriores direito e esquerdo (em espelho), com predomínio à direita. Além disso, houve diminuição significativa de empinar-se e exploratórios como correr, andar, farejar, e aumento significativo de descansar/dormir e congelar-se. A análise dos testes térmicos revelou presença de alodínia (40º C) e hiperalgesia (46º C) nos membros posteriores direito e esquerdo.CONCLUSÃO: O modelo induziu mononeuropatia ciática dolorosa expressa por comportamentos espontâneos sugestivos de dor crônica, além de alodínia e hiperalgesia.
BACKGROUND AND OBJECTIVES: Neuropathic pain is a frequent and challenging condition in terms of management, thus requiring the use of experimental models to better understand its mechanisms. This study aimed at surgically reproducing chronic sciatic nerve constriction model and at quantifying self-directed behaviors suggestive of experimental chronic neuropathic pain during four weeks.METHOD: Twenty-one Wistar rats were divided in three groups: normal (n = 7), pseudo-surgical (n = 7) and surgical (n = 7). The pseudo-surgical group was submitted to bilateral sciatic nerve exposure without injury. The surgical group was submitted to right sciatic nerve exposure and constriction with mononylon thread 4.0 in four sites 2 mm apart from each other. Left sciatic nerve was exposed without injury. RESULTS: Behavioral analysis has shown significant increase (p < 0.05) in scratching and biting right and left hind limbs (in mirror), predominantly to the right. In addition there has been significant decrease in rearing up and exploratory behaviors such as running, walking and sniffing, and significant increase in resting / sleeping and freezing. Thermal tests analysis has shown allodynia (40º C) and hyperalgesia (46º C) in right and left hind limbs. CONCLUSION: The model has induced painful sciatic single neuropathy expressed by spontaneous behaviors suggestive of chronic pain, in addition to allodynia and hyperalgesia
Subject(s)
Animals , Male , Female , Rats , Behavior, Animal , Chronic Pain/physiopathology , Sciatic Nerve/injuries , Sciatic Neuropathy/physiopathology , Constriction , Disease Models, Animal , Hyperalgesia/physiopathology , Pruritus/physiopathology , Rats, WistarABSTRACT
The rat sciatic nerve is a well-established model for the study of recovery from peripheral nerve injuries. Traditional methods of assessing nerve regeneration after nerve injury and repair, such as electrophysiology and histomorphometry, despite widely used in neural regeneration experiments, do not necessarily correlate with return of motor and sensory functions. The aim of this experimental study is to investigate the possible correlation between several parameters of peripheral nerve regeneration after repair of sectioned sciatic nerve in Wistar rat. A two-stage approach was used to obtain 17 parameters after electrophysiological, morphometric and sciatic functional index evaluations. Pearson's correlation analysis was performed between these results. Only two positives correlations between different classes of peripheral nerve assessments were noted, between sciatic functional index and proximal nerve fiber diameter (r=0.56, p<0.01) and between sciatic functional index and distal fiber diameter (r=0.50, p<0.01). The data presented in our study demonstrates that there is a poor correlation between the sciatic functional index and outcome measures of electrophysiological and morphometric evaluations.
O nervo ciático do rato é o modelo mais amplamente utilizado para o estudo da regeneração após uma lesão de nervo. Apesar do uso amplo para a avaliação da regeneração os métodos tradicionais, como a avaliação eletrofisiológica e histomorfométrica, nem sempre apresentam correlações com a recuperação motora e sensitiva. O objetivo deste estudo é investigar as possíveis correlações entre vários parâmetros da regeneração após a secção e reparo do nervo ciático do rato. Foi utilizado um experimento dividido em dois estágios para obter 17 parâmetros após a realização de avaliações eletrofisiológica, histomorfométrica e funcional. A análise das possíveis correlações foi obtida através da aplicação do método de Pearson. Somente duas correlações positivas entre diferentes tipos de avaliações foram obtidas, entre o índice funcional ciático e o diâmetro proximal das fibras (r=0,56, p<0,01) e entre o índice funcional ciático e o diâmetro distal das fibras (r=0,50, p<0,01). Concluímos que as correlações entre diferentes métodos de avaliação da regeneração no nervo ciático do rato são pouco freqüentes.