Efecto del ácido láctico en la respuesta celular del sistema inmunitario durante la fase inflamatoria temprana en el nervio isquiático dañado por compresión / Effect of lactic acid on the cellular response of the immune system during the early inflammatory phase in the sciatic nerve damaged by compression

En órganos dañados, el ácido láctico (AL) modifica la respuesta inmune innata e inflamatoria, induciendo una menor expresión de citoquinas pro-inflamatorias, que provocan, la modulación del reclutamiento de células inmunes. El daño por compresión del nervio isquiático (NI) desencadena una respuesta inflamatoria y un aumento exponencial del infiltrado inflamatorio de células inmunes, produciendo la destrucción de axones y pérdida funcional del nervio. El objetivo de este estudio es evaluar el efecto agudo de la inyección de AL, sobre la proporción de células inmunes en la fase inflamatoria temprana, en el sitio de lesión del NI post compresión. Para ello, se utilizaron 15 ratas machos Sprague Dawley adultas, en tres grupos de compresión nerviosa. Un grupo control, un grupo control negativo con placebo (100 µL PBS) y un grupo experimental con inyección de 100 µL de AL [20mM]. Al tercer día los NI se analizaron histológicamente y se estableció la proporción de células inmunes en el sitio de lesión. Los resultados muestran que la inyección intraneural de AL provoca una disminución en el porcentaje de linfocitos y un aumento en el porcentaje de macrófagos. Este es el primer trabajo de inyección intraneural de AL y demuestra el efecto modulador del AL sobre las células inmunes en el sistema nervioso periférico.

In damaged organs, lactic acid (LA) modifies the innate and inflammatory immune response, inducing a lower expression of pro-inflammatory cytokines, which provoke the modulation of immune cell recruitment. Damage by compression of the sciatic nerve (SN) triggers an inflammatory response and an exponential increase in the inflammatory infiltrate of immune cells, producing the destruction of axons and functional loss of the nerve. The objective of this study is to evaluate the acute effect of the injection of LA, on the proportion of immune cells in the early inflammatory phase, in the site of SN post-compression injury. For this, 15 adult Sprague Dawley rats were used in three groups of nervous compression. A control group, a negative control group with placebo (100 mL PBS) and an experimental group with injection of 100 mL of LA [20mM]. On the third day, the SNs were histologically analyzed and the proportion of immune cells at the injury site was established. The results show that the intraneural injection of LA causes a decrease in the percentage of lymphocytes and an increase in the percentage of macrophages. This is the first work of intraneural injection of LA and demonstrates the modulating effect of LA on immune cells in the peripheral nervous system.

Analysis of BMSCs-intervened viscoelasticity of sciatic nerve in rats with chronic alcoholic intoxication

Abstract Purpose: To investigate the impact of bone mesenchymal stem cells (BMSCs) intervention on the viscoelasticity of sciatic nerve in rats with chronic alcohol intoxication (CAI). Methods: The CAI rat models were prepared, divided into model groups, and treated with either BMSCs or basic fibroblast growth factor (bFGF). Then the rats underwent electrophysiological test and the serum levels of malondialdehyde (MDA), superoxide dismutase (SOD), and metallothionein (MT) were measured. Histological observation, stress relaxation test, and creep test were performed for the sciatic nerve of the CAI model in each group. Results: The MDA level of group BMSC was significantly lower (p<0.05) than that of groups MOD (the CIA model) and bFGF. The SOD and MT levels were higher in group BMSC than in groups MOD and bFGF (p<0.05). The motor nerve conduction velocity and amplitude were higher in group BMSC than in groups MOD and bFGF (p<0.05). The amounts of 7200s stress reduction and 7200 s strain increase of the sciatic nerve in group BMSC were greater than those in groups bFGF and MOD (p<0.05). Conclusion: Bone mesenchymal stem cells can improve the metabolism of free radicals, restore the tissue morphology and viscoelasticity of the chronic alcohol intoxication animal model, and positively affect the repairing of the injured sciatic nerve.

Analysis of the muscle tissue of Wistar rats submitted to the sciatic nerve compression model and cryotherapy / Análise do tecido muscular de ratos Wistar submetidos ao modelo de compressão do nervo isquiático e à crioterapia

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.

The effect of gestational diabetes mellitus on sciatic nerve in adult offspring rats / Efecto de la diabetes mellitus gestacional sobre el nervio ciático en ratas adultas

Gestational diabetes mellitus (GDM) is one form of diabetes affect approximately 7 % of pregnancies. Diabetic peripheral neuropathy (DPN) is a common complication of diabetes that is associated with loss of nerve fibers, myelin abnormalities and significant decrease in the expression of myelin basic protein (MBP) in peripheral nerves. This study was done to determine the effect of induced diabetes during pregnancy on sciatic nerve in adult rat offspring. In this study, wistar rats' dams were allocated to control and diabetic groups. Diabetic rats were received 40 mg/kg/body weight of streptozotocin (STZ) on the first day of gestation. Six offspring of each group were randomly selected on 12 weeks postnatal and histopathological changes in their nerve tissue were examined through H&E staining and transmission electron microscopy. Furthermore, the expression of MBP in sciatic nerve was examined by immunohistochemistry. We found that the myelinated fiber number of sciatic nerve in offspring of diabetic rats was reduced compared to the controls, but this difference was not significant. The average thickness of the myelin sheath of sciatic nerve fibers in the control and GDM was 97.1±0.1and 94.1±0.2 µm, respectively that the difference was not statistically significant. The expression of MBP protein in the myelin sheath of both groups was similar. TEM results showed that myelin sheath of diabetic offspring had not any changes compared to control. Atrophy of axons and schwannocytus (Schwann cells) alterations were not observed in diabetic offspring. Induction of diabetes during pregnancy reduced the number of nerve fibers and thickness of the myelin sheath. But it has no effect on MBP expression and schwannocytus morphology.

La diabetes mellitus gestacional (DMG) es una forma de diabetes que afecta aproximadamente al 7 % de los embarazos. La neuropatía periférica diabética (NPD) es una complicación frecuente de la diabetes asociada a la pérdida de fibras nerviosas, anomalías de la mielina y disminución significativa de la expresión de la proteína básica de mielina (PBM) en los nervios periféricos. Este estudio se realizó para determinar el efecto de la diabetes inducida durante el embarazo en el nervio ciático en descendientes de ratas adultas. Las ratas Wistar madres fueron asignadas a los grupos control y diabéticas. Las ratas diabéticas recibieron 40 mg/kg/peso corporal de estreptozotocina (STZ) el primer día de gestación. Seis descendientes de cada grupo fueron seleccionados al azar en la semana 12 postnatal y los cambios histopatológicos en su tejido nervioso se examinaron a través de tinción H-E y microscopía electrónica de transmisión. Además, la expresión de PBM en el nervio ciático se examinó mediante inmunohistoquímica. Se encontró que el número de fibras mielinizadas de nervio ciático en descendientes de ratas diabéticas se redujo en comparación con los controles, pero esta diferencia no fue significativa. El espesor medio de la vaina de mielina de las fibras nerviosas ciáticas en el control y DMG fue de 97,1±0,1 y 94,1±0,2 µm, respectivamente, y la diferencia no fue estadísticamente significativa. La expresión de la proteína PBM en la vaina de mielina de ambos grupos fue similar. Los resultados del TEM mostraron que la vaina de mielina de la descendencia diabética no tuvo ningún cambio en comparación con el control. La atrofia de los axones y las alteraciones de los schwannocitos (células de Schwann) no se observaron en descendientes diabéticos. La inducción de diabetes durante el embarazo redujo el número de fibras nerviosas y el grosor de la vaina de mielina. Pero no tiene ningún efecto sobre la expresión de PBM y la morfología de las schwannocitos.

Regenerative capacity and histomorphometric changes in rat sciatic nerve following experimental neurotmesis / Capacidad regenerativa y cambios histomorfométricos en el nervio ciático de ratas luego de una neurotmesis experimental

Through a wide range of cellular and molecular events, the peripheral nervous system is endowed with great regenerative capacity, responding immediately to injuries that occur along the length of the nerve. The aim of this study was to histomorphometrically assess the degree of maturity of the nervous tissue and possible microscopic changes in newly formed nerve segments 60 days after experimental neurotmesis of the sciatic nerve in rats. Control Group (CG) and an Injury Group (IG) were used. IG underwent neurotmesis of the sciatic nerve of the right foot, with immediate surgical repair using the tubulization technique. 60 days following experimental surgery, animals from both groups had their sciatic nerves collected for histomorphometric analysis. Statistical analysis was performed, using the Student t-test for independent samples, expressed as mean ± standard deviation, with 5% significance. In the event of injury, peripheral nerve tissue is mobilized in an intrinsic self-healing process. 60 days following of nerve regeneration in neurotmesis injury, the peripheral nerve presents a segment joining the newly formed neural stump. The new stump has a number of regenerated axons compatible with an intact nerve, but which still show great immaturity in the axonal structural layers of the nerve.

Mediante diversos procesos celulares y moleculares, el sistema nervioso periférico tiene una gran capacidad regenerativa, respondiendo inmediatamente a las lesiones ocurridas a lo largo de su extensión. El objetivo de este estudio fue evaluar histomorfométricamente el grado de madurez del tejido nervioso y los posibles cambios microscópicos en los segmentos nerviosos recién formados 60 días después de la neurotmesis experimental en el nervio ciático de ratas. Se utilizaron 9 ratas (Wistar) separadas en grupo control (GC, n= 4) y Grupo lesión (GL, n= 5). A los 60 días de vida, el grupo GL fue sometido a neurotmesis del nervio ciático de la miembro posterior derecho, con inmediata corección quirúrgica con la técnica de tubolización. Completados 60 días luego de la cirugía experimental, los animales de ambos grupos fueron anestesiados y sus nervios ciáticos seccionados para el análisis histomorfométrico. Se realizó un análisis estadístico utilizando la prueba t de Student para muestras independientes, expresado como media ± desviación estándar, con un 5% de significancia. A los 60 días de la lesión por neurotmesis, el nervio ciático del GL presentó alteraciones histomorfométricas significativas para las variables: número de vasa nevorum, densidad de fibras mielínicas, diámetro axonal y de fibras mielínicas, espesor de la vaina de mielina y razón G, con similitud solamente para los números absolutos de fibras mielínicas regeneradas. El nervio periférico durante su proceso regenerativo, pasa por grandes alteraciones estructurales, siguiendo una secuencia coordinada de acciones, que dependiendo de las condiciones del microambiente donde ocurre esta regeneración, podrá ser clave para el nivel de regenerecion nerviosa periférica.

Análise do potencial citotóxico agudo da bupivacaína e bupivacaína em excesso enantiomerico de 50 por cento (S75-R25) incorporadas a microesferas sobre o nervo ciático de ratos / Analysis of the acute cytotoxic potential of bupivacaine and 50 percent enantiomeric excess bupivacaine (S75-R25) incorporated into microspheres in rat sciatic nerves / Análisis del potencial citotóxico agudo de la bupivacaína y bupivacaína en exceso enantiomérico de 50 por ciento (S75-R25) incorporadas a microesferas sobre el nervio ciático de ratones

JUSTIFICATIVA E OBJETIVOS: A duração do efeito dos anestésicos locais (AL) pode ser ampliada pela sua incorporação aos sistemas de liberação prolongada como microesferas. No entanto, a possibilidade de que os sistemas de liberação prolongada de AL sejam neurotóxicos não tem recebido a devida atenção na literatura. Este estudo teve o objetivo de investigar os efeitos de microesferas de ácido poliláctico-co-glicólico puras, preenchidas com bupivacaína em excesso enantiomérico de 50 por cento ou com bupivacaína (BP), assim como os efeitos da bupivacaína em excesso enantiomérico de 50 por cento em nervo ciático de ratos Wistar. MÉTODO: Os ratos foram alocados em quatro grupos de acordo com o tempo de avaliação (dois, quatro, seis e oito dias) e denominados conforme a solução injetada sobre o nervo ciático: microsferas com bupivacaína em excesso enantiomérico de 50 por cento (MBE), microesferas com bupivacaína (MB); microesferas puras (MP) e bupivacaína em excesso enantiomérico de 50 por cento (BE). RESULTADOS: Nos cortes histológicos semifinos observou-se distribuição regular homogênea nas fibras de colágeno no endoneuro e nenhuma alteração degenerativa dos axônios ou das bainhas de mielina foi constatada. Nos cortes ultrafinos foram observados axônios mielinizados e fibras de Remak de aspecto normal com axoplasma apresentando distribuição homogênea de neurofilamentos e microtúbulos. A análise histomorfométrica dos axônios não revelou diferença significativa entre os diâmetros dos axônios dos grupos estudados.

BACKGROUND AND OBJECTIVES: The duration of Local Anesthetic (LA) effects can be expanded by its incorporation into systems of sustained release microspheres. However, the possibility that LA sustained release systems are neurotoxic has not received due attention in literature. The objective of this study was to investigate the effects of pure microspheres of poly(lactic-co-glycolic acid), filled with 50 percent enantiomeric excess bupivacaine or bupivacaine (BP), as well as the effects of 50 percent enantiomeric excess bupivacaine in the sciatic nerve of Wistar rats. METHODS: The rats were allocated into four groups according to the evaluation time (two, four, six, and eight days) and nominated according to the injected solution on the sciatic nerve: Microspheres with 50 percent Enantiomeric excess Bupivacaine (MEB), Microspheres with Bupivacaine (MB), Pure Microspheres (PM), and 50 percent Enantiomeric excess Bupivacaine (EB). RESULTS: In semi-fine histologic sections, no regular homogeneous distribution of collagen fibers in the endoneurium or degenerative changes of axons and myelin sheaths were observed. In ultrathin sections, we found myelinated axons and normal Remak fibers with axoplasm showing homogeneous distribution of neurofilaments and microtubules. Histomorphometric analysis of axons revealed no significant difference between the axon diameters of the studied groups.

JUSTIFICATIVA Y OBJETIVOS: La duración del efecto de los anestésicos locales (AL), puede ser ampliada por su incorporación a los sistemas de liberación prolongada como microesferas. Sin embargo, la posibilidad de que los sistemas de liberación prolongada de AL sean neurotóxicos, no ha recibido la debida atención en la literatura. Este estudio tuvo el objetivo de investigar los efectos de microesferas de ácido poliláctico-co-glicólico puras, rellenados con bupivacaína en exceso enantiomérico de 50 por ciento o con bupivacaína (BP), como también los efectos de la bupivacaína en exceso enantiomérico de 50 por ciento en nervio ciático de ratones Wistar. MÉTODO: Los ratones se dividieron en cuatro grupos de acuerdo con el tiempo de evaluación (dos, cuatro, seis y ocho días), y fueron denominados conforme a la solución inyectada sobre el nervio ciático: microesferas con bupivacaína en exceso enantiomérico de 50 por ciento (MBE), microesferas con bupivacaína (MB); microesferas puras (MP) y bupivacaína en exceso enantiomérico de 50 por ciento (BE). RESULTADOS: En los cortes semifinos se observó la distribución regular homogénea en las fibras de colágeno en el endoneuro y no se comprobó ninguna alteración degenerativa de los axones o de las vainas de mielina. En los cortes ultrafinos fueron observados axones mielinizados y fibras de Remak de aspecto normal con axoplasma presentando una distribución homogénea de neurofilamentos y microtúbulos. El análisis histomorfométrico de los axones no reveló diferencias significativas entre los diámetros de los axones de los grupos estudiados.

Impacto isquiofemoral: uma etiologia de quadril doloroso: relato de caso / Ischiofemoral impingement: an etiology of hip pain: case report

A associação entre dor no quadril, anormalidade do músculo quadrado femoral na ressonância magnética (RM) e estreitamento do espaço isquiofemoral tem sido relatada na literatura atual, levantando a possibilidade de que essa lesão muscular seja causada pelo impacto isquiofemoral. Tal diagnóstico foi observado em algumas mulheres de meia-idade com ou sem história de trauma ou cirurgia. Os autores relatam aqui uma mulher de 31 anos de idade, que apresentava dor no quadril sem história de trauma, com evidência de estreitamento do espaço isquiofemoral e edema no músculo quadrado femoral. Foi realizado tratamento não cirúrgico com alívio dos sintomas. O diagnóstico de impacto isquiofemoral deve ser considerado em pacientes do sexo feminino com queixa de dor no quadril sem outra causa evidente.

An association between hip pain and quadratus femoris muscle abnormality on magnetic resonance imaging (MRI) with concurrent narrowing of the ischiofemoral space has been reported in the recent literature. This raises the possibility that the muscle damage observed is due to ischiofemoral impingement. This diagnosis has been noted in middle-aged females either with or without a history of trauma or surgery, is a rarely described feature. We report here on a 31-year-old woman who presented with non-traumatic hip pain and evidence of narrowing of the ischiofemoral space and edema in the quadratus femoris. Nonsurgical treatment was administered, which relieved her hip pain. The diagnosis of ischiofemoral impingement should be considered in female patients complaining of hip pain without any other evident cause.

Histologic study on the protective effect of alpha-lipoic acid in sciatic nerve neurotoxicity induced by cypermethrin in albino rats

This work was undertaken to study the possible protective role of ex-lipoic acid [ALA] in the sciatic nerve of rats intoxicated with the pesticide cypermethrin by histological and morphometric methods. Thirty adult male albino rats were randomly divided into five equal groups [six rats each]: group I [control group] received no treatment, group II received daily 1 ml of corn oil orally, group III received 100 mg/kg of oral ALA daily, group IV received oral cypermethrin [75 mg/kg] daily, and group V received both ALA and cypermethrin. After 5 days treatment, both sciatic nerves were dissected out from each animal, and then semithin and ultrathin sections were prepared for light and electron microscopic examinations. Morphometric and statistical analyses were also conducted, After cypermethrine administration, the sciatic nerve showed nerve damage particularly affecting the myelinated nerve fibers. The lesions were manifested as axonal damage and changes in the myelin sheath. Myelinated nerve fibers were swollen showing Wallerian degeneration. Ultrastructurally, myelin sheaths exhibited fragmentation, vacuolations, and hyalinization, Axoplasm displayed shrinkage, vacuolations, fragmentations, myelin figures, and intra-axonal wipe spaces, with swelling of Schwann cells. Unmyelinated fibers were minimally affected. Concomitant administration of ALA with cypermethrine displayed an observable protection against these changes. ALA showed a protective effect against sciatic neurotoxicity induced by cypermethrin in albino rats

Beneficial effects of treadmill training in experimental diabetic nerve regeneration

OBJECTIVES: We investigated the effects of treadmill training (10 weeks) on hindlimb motor function and nerve morphometric parameters in diabetic rats submitted to sciatic nerve crush. MATERIALS AND METHOD: Wistar rats (n = 64) were divided into the following groups: non-diabetic; trained non-diabetic; non-diabetic with sciatic nerve crush; trained non-diabetic with sciatic nerve crush; diabetic; trained diabetic; diabetic with sciatic nerve crush or trained diabetic with sciatic nerve crush. Diabetes was induced by streptozotocin injection (50 mg/kg, iv). Hindlimb motor function was evaluated weekly by assessing sciatic functional indices, and the proximal and distal portions of the sciatic nerve were used for morphometric analysis. RESULTS: At 13 weeks post-injury, the distal nerve portion of all injured groups and the proximal nerve portion of the diabetic with sciatic nerve crush group presented altered morphometric parameters such as decreased myelinated fiber diameter (~7.4 + 0.3μm vs ~4.8 + 0.2μm), axonal diameter (~5 + 0.2μm vs ~3.5 + 0.1μm) and myelin sheath thickness (~1.2 + 0.07μm vs ~0.65 + 0.07μm) and an increase in the percentage of area occupied by endoneurium (~28 + 3 percent vs ~60 + 3 percent). In addition, in the non-diabetic with sciatic nerve crush group the proximal nerve portion showed a decreased myelinated fiber diameter (7.4+0.3μm vs 5.8 + 0.3μm) and myelin sheath thickness (1.29 + 0.08μm vs 0.92 + 0.08μm). The non-diabetic with sciatic nerve crush, trained non-diabetic with sciatic nerve crush, diabetic with sciatic nerve crush and trained diabetic with sciatic nerve crush groups showed normal sciatic functional index from the 4th,4th,9th and 7th week post-injury, respectively. Morphometric alterations in the proximal nerve portion of the diabetic with sciatic nerve crush and non-diabetic with sciatic nerve crush groups were either prevented or reverted to values similar to the non-diabetic group by treadmill training. CONCLUSION: Diabetic condition promoted delay in sciatic nerve regeneration. Treadmill training is able to accelerate hindlimb motor function recovery in diabetic injured rats and prevent or revert morphometric alterations in proximal nerve portions in non-diabetic and diabetic injured rats.

Síndrome lumbociático de etiología distinta a hernia discal / Etiology of lumbosciatic syndrome different from lumbar herniated disk

La causa más frecuente de lumbociática es la hernia de disco y la patología asociada de estenosis foraminal, espondilolistesis y entesopatía de la articulación facetaria, incluyendo quistes sinoviales. Existen una serie de condiciones que pueden presentar un cuadro clínico similar, y el problema es detectar estas causas infrecuentes en un universo muy grande de pacientes con patología discal. Esto crea una situación potencialmente peligrosa, en la cual se podría interpretar la sintomatología secundaria, por ejemplo a un tumor, como producida por una hernia discal, por otro lado asintomática. En base a una historia clínica cuidadosa y al uso racional de los exámenes complementarios, se puede sospechar aquellos casos que pudieran albergar esta patología de baja incidencia, pero de gran importancia clínica. Se revisan las causas más importantes que pueden provocar un síndrome lumbociático y que deben incluirse en el diagnóstico diferencial, como el síndrome piriforme, tumores intradurales y del nervio ciático y fístulas durales.

The most frequent etiology of sciatic pain is herniation of the nucleus pulposus and associated entesopathic diseases, including synovial cysts. There are several conditions that can present with a similar clinical picture, and the clinician is confronted with the problem of detecting this infrequent occurrences. This creates a potentially dangerous condition of thinking that an asymptomatic disc herniation is causing the symptoms that are originated higher by a tumor for example. With a careful history and judicious use of ancillary examinations, specially NMR, most of the cases can be suspected. The principal causes of non-discal sciatica are reviewed, including piriform syndrome, tumors of the spine and sciatic nerve, and dural fistulae.

Uso do laser, 670 nm, no quadro álgico de ratos submetidos à modelo experimental de ciatalgia / Use of laser, 670 nm, in painful episodes of rats submitted to experimental model of sciatica

A ciatalgia deve-se a compressão do nervo isquiático em algum ponto de seu trajeto, e seu tratamento consiste em solucionar a causa da compressão nervosa, seja por tratamento cirúrgico ou conservador. Alguns recursos fisioterapêuticos atuam basicamente na redução dos sintomas ocasionados por este distúrbio. O objetivo deste estudo foi verificar a eficácia do laser 670 nm, em duas diferentes densidades de energia, na redução do quadro álgico, em ratos submetidos a modelo experimental de ciatalgia. Foram utilizados 18 ratos, divididos em 3 grupos: G1 (n=6) submetidos à ciatalgia e simulado o tratamento (grupo placebo), G2 (n=6) submetido à ciatalgia e tratados com laser 2 J/cm², G3 (n=6) submetidos à ciatalgia e irradiados com laser 4 J/cm². O nervo isquiático do membro posterior direito dos animais foi exposto e compressão com fio catgut em 4 pontos ao redor do nervo foi realizada. No 3° dia pós-operatório, iniciou-se o tratamento com laser na região do procedimento cirúrgico do membro posterior direito durante 10 dias consecutivos. Verificou-se por meio da marcha, o tempo em que o membro permanecia no ar nos períodos: anterior à ciatalgia, pré e pós-tratamento. Os resultados demonstraram que o laser não foi eficaz na redução do quadro álgico, porém com 4 J/cm² houve efeito positivo, sem restabelecimento completo da funcionalidade.

Sciatica is caused by the sciatic nerve compression in some point of its course, and its treatment consists of solving the nervous compression cause, either by surgical or conservative treatment. Some physiotherapeutic resources act basically in the reduction of the symptoms caused by this disturbance. The aim of this study was to verify the effectiveness of the laser 670 nm, in two different energy densities, in the pain reduction, in rats submitted to a sciatica experimental model. Eighteen rats, divided in 3 groups were used: G1 (n=6) submitted to sciatica and simulated treatment (placebo group), G2 (n=6) submitted to sciatica and treated with laser 2 J/cm², G3 (n=6) submitted to sciatica and irradiated with laser 4 J/cm². The hamstring nerve of the animals' right hind limb was exposed and compression with catgut thread in 4 points of the nerve was performed. On the 3rd post-operation day, the treatment was begun with laser in the surgical procedure area of the right hind limb for 10 days. The time during which the limb remained on the air was verified through gait in the following periods: previous to the sciatica, before and after treatment. The results have demonstrated that the laser was not effective in the pain reduction; however, with 4 J/cm² there was positive effect, without complete functionality reestablishment.

Origem e distribuição dos nervos isquiáticos em caprinos da raça Saanen / Origin and distribution of the ischiatic nerves in goats of the Saanen breed

Estudaram-se a origem e distribuição dos nervos isquiáticos, de ambos os antímeros, em 30 caprinos (Capra hircus) da raça Saanen, sendo 16 machos e 14 fêmeas. Estes animais foram coletados após morte natural e submetidos à fixação em solução aquosa, a 10 por cento, de formaldeído. Os nervos isquiáticos originaram-se 28 vezes (93,3 por cento) do ramo ventral do sexto nervo espinhal lombar e dos ramos ventrais do primeiro e segundo nervos espinhais sacrais; além disso, esses nervos tabém receberam duas vezes (6,7 por cento), contribuição do ramo ventral do terceiro nervo espinhal sacral. Os nervos isquiáticos cederam, em todos os animais, ramos para os músculos glúteos médios, glúteos profundos, gluteobíceps, gêmeos, semitendíneos e semimembranáceos. Sobretudo, notaram-se arranjos peculiares desses ramos musculares para cada espécime. Através da aplicação da prova de Wilcoxon, com nível de significância de 0,05, não se observaram diferenças significativas entre as freqüências de ramos musculares dos nervos isquiáticos, que foram cedidos para os antímeros direito e esquerdo, e ainda em relação ao sexo dos caprinos da presente investigação.

The origin and distribution of the ischiatic nerves at both sides were studied in 30 goats (Capra hircus) of the Saanen breed, being 16 males and 14 females. These specimens were collected after natural death of the animals and submitted to fixation in a 10 percent formaldehyde solution. The ischiatic nerves arose from the ventral branch of the sixth lumbar and the first and second sacral spinal nerves in 28 cases (93.3 percent). In addition, these nerves also received contributions from the ventral branch of the third sacral spinal nerve in two cases (6.7 percent) at both sides. In all animals, the right and left ischiatic nerves gave off branches to the muscles gluteus medius, gluteus profundus, gluteobiceps, gemelli, semitendinosus, and semimembranosus muscles. In particular, peculiar arrangements of these muscular branches were noticed for each specimen. By using the Wilcoxon test with significance level at 0.05, there were no significant differences among the frequencies of muscular branches of the ischiatic nerves emitted to the right and left sides, and also in relation to the sex of the goats in the present investigation.

Hematoma intraneural experimental em ratos: avaliação da recuperação funcional e histomorfometria neural / Experimental intraneural hematoma model in rats: evaluation of functional recovery and neural histomorphometry

A formação do hematoma intraneural com comprometimento de nervos periféricos pode ocorrer após trauma ou coagulopatias. O tratamento expectante ou abordagem cirúrgica descompressiva ainda não estão definidos. Foram estudados 40 ratos da raça Wistar divididos em 4 grupos. No grupo A realizou-se injeção intraneural de 0,2 ml de sangue autógeno no nervo ciático direito. No grupo B, após produção do hematoma, fez-se descompressão imediata com epineurotomia longitudinal. No grupo D realizamos liberação imediata do hematoma com neurólise interfascicular. No grupo C (CONTROLE) apenas realizou-se a exposição do nervo ciático sem formação de hematoma. A avaliação da função nervosa foi feita com o índice de Função Ciática de Bain-Mackinnon-Hunter (IFC). O grupo A apresentou IFC inicial de -28,43, com recuperação funcional no 5° dia. A drenagem imediata desse hematoma através de uma epineurotomia longitudinal (B) determinou retorno da função ciática normal desde o 1° dia (IFC= -14,42). Tratando o hematoma através da neurólise interfascicular observamos um IFC inicial de -23,69 e retorno da função ciática normal no 3° dia. Os parâmetros histomorfométricos apontaram melhora dos parâmetros de isquemia após os 2 tipos de intervenção cirúrgica aplicadas neste estudo. Não houve diferença entre os tipos de intervenções aplicadas.

Emergence of intraneural hematoma with involvement of peripheral nerves can occur after trauma or coagulation disorders. The decision for expectant management or decompressive surgical techniques is still controversial. Forty male Wistar rats were divided into 4 groups. In group A, an intraneural injection of autologous blood was provided at the right sciatic nerve. In group B, after the hematoma creation, a longitudinal epineurotomy was performed. In the group C (sham-operated), the sciatic nerve was exposed without hematoma. In group D. immediately after the hematoma creation, an interfascicular neurolysis was performed. Nerve function recovery was assessed using the Bain-Mackinnon-Hunter Sciatic Function Index (SFI). At the end of the study, the animals were sacrificed and a specimen of the sciatic nerve at compression midpoint was removed for morphometric analysis. Group A displayed an initial SFI of -28.43, with full functional recovery on the fifth day. Immediate drainage of the hematoma by longitudinal epineurotomy (group B) promoted recovery of normal sciatic function on the first day (SFI -14.42). Addressing the hematoma via interfascicular neurolysis resulted in an initial SFI of -23.69 and recovery of normal sciatic function on the third day. The morphometric variables indicated an improvement of ischemic parameters following both types of surgical intervention.

Correlation between parameters of electrophysiological, histomorphometric and sciatic functional index evaluations after rat sciatic nerve repair / Correlações entre parâmetros obtidos das avaliações eletrofisiológica, histomorfométrica e do índice funcional ciático após o reparo do nervo ciático do rato

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.

[Ischemic and reperfusion injury of adult rat sciatic nerve]

Ischemia plays a major role in development of pathological changes in various neuropathies. Reperfusion amplifies physiological and pathological abnormalities in ischemic nerves. In this research, we studied ischemic-reperfusion [IR] injury of sciatic nerve up to 14 days of reperfusion. IR was produced by ligation and release of nooses around supplying vessels to the sciatic nerve. 30 rats were assigned into 5 groups of 6. Group 1 [control] did not undergo IR while the 4 remaining groups after three hours of complete hind leg ischemia underwent reperfusion within 0hr, 3hrs, 7 days and 14 days. Pathologically, two phases were identifiable. During phase 1 [0-3 hrs] fiber degeneration and endoneurial edema were observed. During phase 2 [7 days and, 14 days] prominent fiber degeneration and prominent endoneurial edema were observed. Loss of function occurred in more than 75% of the rats with ischemia alone, in comparison with the control group the maximum reduction in activities was observed amongst the group of rats reperfused within 3 hours. IR injury depends on duration of reperfusion. Microvascular events during reperfusion may enhance the nerve fiber damage following the ischemia period

Amelioration the effect of sciatic nerve transection in the dorsal root ganglia in albino rat by methylprednisolone acetate

The present study was performed to investigate the neuroprotective effect of methylprednisolone [MP] acetate on the cells of the dorsal root ganglia [DRG] following transection of the sciatic nerve in albino rats. Twenty adult male Sprague-Dawley albino rats were allocated into 4 groups. Animals of group II were injected with a single dose of normal saline. Animals of group II were injected with a single dose of MP acetate. Animals of both groups were subjected to surgical Sham's operation prior to the injection. Animals of both groups III and IV were subjected to transection of the right sciatic nerve. Those of group IV were injected with a single dose of MP acetate following transection. After 2 weeks, all animals were sacrificed and the fifth lumbar DRG were excised and processed for light microscopy. The results showed marked pathological lesions in the cells of DRG of animals of group III in the form of chromatolysis, eccentric position of nuclei, appearance of intracytoplasmic vacuoles, necrosis and disappearance of some DRG neurons. Inflammatory mononuclear cells were observed in the vicinity of degenerating and necrotic cells. The cells of DRG of animals of group IV showed a picture almost similar to that of the cells of DRG of animals of both control groups I and II. In conclusion, the present study has proved the neuroprotective effect of MP acetate in experimental model of peripheral nerve crush injury

Inhabitual case of sciatica in a child: presacral hydatid cyst

Hydatid cyst involving the pelvis in children is extremely rare. We report a case of an 11-year old boy with sciatic pain. Ultrasonography and computerised tomography scan showed a presacral cyst mass extending into the intervertebral foramen at the S1 level. The intraoperative findings and histologic examination indicated the diagnosis of a solitary hydatid cyst. After surgical enucleation, there was no envidence of recurrence on long-term follow-up

Fish oil supplementation improves histological changes after sciatic nerve injury in rats

Peripheral nerve injury often leads to neuropathic pain. The potential effect of dietary supplementation with fish oil [Omega-3] fatty acids on the injured sciatic nerve was studied in albino rats. 25 adult male albino rats weighing 200g were divided into three groups. Group I consisted of five rats were fed a non purified diet supplemented with olive oil for six weeks, they were used as control group. Group II consisted of ten rats were undergone sciatic nerve crush injury and fed a non purified diet supplemented with olive oil for six weeks, they were used as the injured comparative group. Group III consisted of ten rats were undergone sciatic nerve crush injury and were fed a non purified diet supplemented with [Omega-3] fatty acid enriched fish oil concentrate at a dose of 0.5 g/kg/day for six weeks. Histological study showed partially intact neurolemmal sheath, absence of endoneural oedema and signs of regeneration in group three in contrast with group two in which there were apparent signs of degeneration. This beneficial effect of fish oil on injured sciatic nerve with attenuated histological damage suggested a treatment role for patients suffering from neuropathic pain

Uso da celulose liofilizada em lesöes de nervos periféricos com perda de substância / Use of lyophilized cellulose in peripheral nerve lesions with loss of substance

O trabalho analisou a celulose liofilizada como invólucro de lesöes de nervos periféricos, com perda de substância, investigando a intensidade de reaçäo inflamatória e o alinhamento axonal. Dez cäes foram divididos em 3 grupos: Grupo 1 - seccçäo e recolocaçäo de 1 cm de nervo ciático; Grupo 2 - näo recolocado fragmento seccionado; Grupo 3 - sutura epineural, sem invólucro celulósico. A recuperaçäo motora iniciou na oitava semana, lenta e progressiva, sem recuperaçäo total. A autópsia mostrou reaçäo fibrótica ao redor da celulose e aderência ao plano muscular. Quando o enxerto foi recolocado, constatou-se continuidade do nervo com aumento de calibre local. Nos dez cäes foi observada fibrose e regeneraçäo neural variáveis na área de secçäo do nervo. Os grupos 1 e 3 mostraram coaptaçäo entre cotos e enxerto. Concluiu-se que a celulose liofilizada provocou moderada reaçäo fibrótica com realinhamento e crescimento axonal quando foi recolocado, como enxerto, o fragmento do nervo seccionado