Middle cluneal nerve entrapment sites in the surgical field.

INTRODUCTION: Middle cluneal nerve (MCN) entrapment around the sacroiliac joint elicits low back pain (LBP). For surgical decompression to be successful, the course of the MCN must be known. We retrospectively studied the MCN course in 15 patients who had undergone MCN neurolysis. METHODS: Enrolled in this retrospective study were 15 patients (18 sides). We inspected their surgical records and videos to determine the course of the entrapped MCN. The area between the posterior superior- and the posterior inferior iliac spine was divided into areas A-D from the rostral side. The MCN transit points were identified at the midline and the lateral edge connecting the posterior superior- and posterior inferior iliac spine. Before and 6 months after surgery, the patients recorded the degree of LBP on the numerical rating scale and the Roland-Morris Disability Questionnaire. RESULTS: We decompressed 24 MCNs. The mean number was 1.3 nerves per patient (range 1-2). The MCN course was oblique in the cranio-caudal direction; the nerve tended to be observed in areas C and D. In six patients (40%), we detected two MCN branches, they were in the same area and adjacent. Postoperatively, LBP was improved significantly in all patients. CONCLUSION: Between the posterior superior- and the posterior inferior iliac spine, the MCN ran obliquely in the cranio-caudal direction; it was prominent in areas on the caudal side. In six (40%) patients, we decompressed two adjacent MCNs. Our findings are useful for MCN decompression surgery.

Effect of exercise on cluneal nerve entrapment neuropathy: a case report.

BACKGROUND: Low back pain is an important disability problem frequently encountered in the clinic. In the literature, it has been shown that neuropathic pain in chronic low back pain is quite common in patients. Although superior cluneal nerve entrapment syndrome is an underdiagnosed cause of low back and leg pain, differential diagnosis is very important anatomically and clinically. The superior cluneal nerves are pure sensory nerves that innervate the skin of the upper part of the buttocks. In the literature, methods such as surgery, nerve blockade, prolotherapy, and acupuncture have been used in the treatment of cluneal nerve entrapment syndrome, but there are no studies on exercise. In this case report, our aim is to explain the importance of differential diagnosis in cluneal nerve entrapment syndrome, which is one of the common causes of low back pain in the clinic, and the effects of exercise in this disease. CASE PRESENTATION: A 22-year-old, Turkish-ethnicity, male patient with complaints of low back pain, neck-back pain, and weakness did not use alcohol or cigarettes. In his family history, there was a history of diabetes in the mother and diabetes and heart failure in the father. He had a history of osteoporosis, epilepsy, asthma, sarcoidosis, and cardiac arrhythmia. The patient reported that he suffered from constipation three to four times a month. As a result of the detailed evaluation, the planned exercise prescription was taught to the patient, and after it was confirmed that the patient did the exercises correctly for 3 days, the exercise brochure was given and followed as a home exercise program for 8 weeks. CONCLUSIONS: Lumbar stabilization exercises, gluteal muscle strengthening exercises, thoracolumbar fascia mobilization, and stretching exercises, which will be given in accordance with the clinical anatomy of the disease after the correct diagnosis in cluneal nerve entrapment syndrome, have been beneficial for the patient. However, we think that randomized controlled studies with a large sample will contribute to the literature.

Anatomical Proximity Between Sciatic Nerve and Ischial Spine and its Relationship to the Development of Deep Gluteal Pain Syndrome.

OBJECTIVE: Deep gluteal syndrome (DGS) is a medical diagnosis in which the pathoanatomy of the subgluteal space contributes to pain. The growing recognition that gluteal neuropathies can be associated with the presence of a bone-neural conflict with irritation or compression may allow us to shed some light on this pathology. This study aims to determine whether the location of the sciatic nerve (SN) in relation to the ischial spine (IS) contributes to the development of DGS. METHODS: The SN - IS relationship was analyzed based on magnetic resonance imaging (MRI) in 15 surgical patients (SPs), who underwent piriformis release, and in 30 control patients who underwent MRI of the pelvis for reasons unrelated to sciatica. The SN exit from the greater sciatic foramen was classified as either zone A (medial to the IS); zone B (on the IS); or zone C (lateral to the IS). RESULTS: The SN was significantly closer to the IS in SPs than in MRI controls (P = 0.014). When analyzing patients of similar age, SNs in SPs were significantly closer (P = 0.0061) to the IS, and located in zone B significantly more (P = 0.0216) as compared to MRI controls. Patients who underwent surgery for piriformis release showed a significant decrease in pain postoperatively (P < 0.0001). CONCLUSIONS: The results from this study suggest that the relationship between the IS and SN may play a role in the development of DGS. This may also help establish which patients would benefit more from surgical intervention.

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.

Recommendation of the best site based on the distribution pattern of extramuscular and intramusular nerves for gluteal muscle injection / Recomendación del mejor sitio para la inyección del músculo glúteo basado en el patrón de distribución de los nervios extramusculares e intramusculares

To reveal the extra- and intramuscular nerve distribution patterns of the gluteus maximus, medius, and minimus, and to provide guidance for gluteal muscle injection in order to avoid nerve injury. Ten adult and 10 child cadavers were used. The superior and inferior gluteal nerves innervating the gluteus maximus, medius, and minimus were dissected, exposed, and sutured in-situ on the muscle. The three gluteal muscles were removed, and the distribution patterns of the intramuscular nerves were revealed by modified Sihler's nerve staining. The nerve distribution pattern was returned to the corresponding position in the body, and the patterns in the four quadrants of the buttock were analyzed. There were 3-12 extramuscular nerve branches of the gluteus maximus, medius, and minimus. After entering the muscle, these nerve branches arborized and anastomosed to form an arc-shaped, nerve-dense zone. The nerve distribution was most dense in the inferomedial region of the superolateral quadrant and the inferolateral region of the superomedial quadrant of the buttocks. The nerve distribution was relatively dense in the inferolateral region of the superolateral quadrant, and the medial region of the inferomedial quadrant. An arc-shaped, nerve-sparse zone in the superolateral and superomedial quadrants near the lower iliac crest accounted for about two-fifths of the two quadrants' limits. The arc-shaped, nerve-sparse zone in the superolateral quadrant is the preferred injection site, and the superomedial quadrant near the lower iliac crest is also recommended as a gluteal intramuscular injection region, free from nerve injury.

El objetivo de este trabajo fue revelar los patrones de distribución nerviosa extramusculat e intramuscular de los músculos glúteo máximo, medio y mínimo y proporcionar orientación para la inyección en la región glútea con el propósito de evitar lesiones nerviosas. Se utilizaron diez cadáveres adultos y diez niños. Los nervios glúteos superior e inferior que inervan a los músculos glúteo máximo, medio y mínimo fueron disecados, expuestos y suturados in situ en el músculo. Se extirparon los tres músculos glúteos y se revelaron los patrones de distribución de los nervios intramusculares mediante la tinción nerviosa de Sihler modificada. El patrón de distribución nerviosa se devolvió a la posición correspondiente en el cuerpo y se analizaron los patrones en los cuatro cuadrantes de la región glútea. Se encontraron 3 a 12 ramos nerviosos extramusculares de los músculos glúteo máximo, medio y mínimo. Después de ingresar al músculo, estas ramas nerviosas se arborizaron y anastomizaron para formar una zona densamente nerviosa en forma de arco. La distribución nerviosa fue de mayor densidad en la región inferomedial del cuadrante superolateral y en la región inferolateral del cuadrante superomedial de la región glútea. La distribución nerviosa era relativamente densa en la región inferolateral del cuadrante superolateral y en la región medial del cuadrante inferomedial. Una zona en forma de arco en los cuadrantes superolateral y superomedial y con escasa inervación, cerca de la cresta ilíaca representaba una parte de los límites de los dos cuadrantes. La zona de poca inervación en forma de arco en el cuadrante superolateral es el sitio de inyección preferido, y el cuadrante superomedial próximo a la cresta ilíaca también se recomienda como una región de inyección intramuscular glútea, libre de lesión nerviosa.

Superior gluteal nerve: a new block on the block? / Nervo glúteo superior: um novo bloqueio a caminho?

Abstract Background and objectives The superior gluteal nerve is responsible for innervating the gluteus medius, gluteus minimus and tensor fascia latae muscles, all of which can be injured during surgical procedures. We describe an ultrasound-guided approach to block the superior gluteal nerve which allowed us to provide efficient analgesia and anesthesia for two orthopedic procedures, in a patient who had significant risk factors for neuraxial techniques and deep peripheral nerve blocks. Clinical report An 84-year-old female whose regular use of clopidogrel contraindicated neuraxial techniques or deep peripheral nerve blocks presented for urgent bipolar hemiarthroplasty in our hospital. Taking into consideration the surgical approach chosen by the orthopedic team, we set to use a combination of general anesthesia and superficial peripheral nerve blocks (femoral, lateral cutaneous of thigh and superior gluteal nerve) for the procedure. A month and a half post-discharge the patient was re-admitted for debriding and correction of suture dehiscence; we performed the same blocks and light sedation. She remained comfortable in both cases, and reported no pain in the post-operative period. Conclusions Deep understanding of anatomy and innervation empowers anesthesiologists to solve potentially complex cases with safer, albeit creative, approaches. The relevance of this block in this case arises from its innervation of the gluteus medius muscle and posterolateral portion of the hip joint. To the best of our knowledge, this is the first report of an ultrasound-guided superior gluteal nerve block with an analgesic and anesthetic goal, which was successfully achieved.

Resumo Justificativa e objetivos O nervo glúteo superior é responsável pela inervação dos músculos glúteo médio, glúteo mínimo e tensor da fáscia lata, todos podem ser lesados durante procedimentos cirúrgicos. Descrevemos uma abordagem guiada por ultrassom para bloqueio do nervo glúteo superior, o que nos permitiu fornecer analgesia e anestesia eficientes para dois procedimentos ortopédicos a uma paciente que apresentava fatores de risco significativos para técnicas neuraxiais e bloqueios profundos de nervos periféricos. Relato de caso Paciente do sexo feminino, 84 anos, cujo uso regular de clopidogrel contraindicava técnicas neuraxiais ou bloqueios profundos de nervos periféricos, apresentou-se para hemiartroplastia bipolar urgente em nosso hospital. Levando em consideração a abordagem cirúrgica escolhida pela equipe de ortopedia, estabelecemos o uso de uma combinação de anestesia geral e bloqueios superficiais de nervos periféricos (femoral, cutâneo lateral da coxa e nervo glúteo superior) para o procedimento. Um mês e meio após a alta, a paciente foi readmitida para desbridamento e correção da deiscência de sutura quando fizemos os mesmos bloqueios e sedação leve. A paciente permaneceu confortável em ambos os casos, sem queixa de dor no período pós-operatório. Conclusões A compreensão profunda da anatomia e da inervação capacita os anestesiologistas a resolver casos potencialmente complexos com abordagens mais seguras, até criativas. A relevância desse bloqueio neste caso resulta da sua inervação do músculo glúteo médio e da porção posterolateral da articulação do quadril. De acordo com nossa pesquisa, este é o primeiro relato de um bloqueio do nervo glúteo superior guiado por ultrassom com objetivo analgésico e anestésico que foi obtido com sucesso.

Variations in the vascular supply of the upper one third of the sciatic nerve

The arteria comitans nervi ischiadica (ACNI), which is a branch of the inferior gluteal artery and represents the axial artery of the inferior extremity, supplies the sciatic nerve in gluteal region. The vascular supply of the upper 1/3rd of the sciatic nerve and the morphological details of the ACNI have not been characterized yet in detail. Hence, we studied the extraneuronal blood supply of the upper 1/3rd of the sciatic nerve by cadaveric dissection. The upper 1/3rd of the sciatic nerve was dissected in the gluteal region by reflecting the gluteus maximus muscle in 33 formalin-fixed cadavers. Variations in the number of ACNI arising from the inferior gluteal artery and length of segments of ACNI were noted. The source of other nutrient branches supplying the sciatic nerve in the gluteal region was also noted. In 86.6% of cases one ACNI was found. 9% of limbs had two ACNI and 1.8% had three ACNI arising respectively from the inferior gluteal artery (IGA). The morphology of the ACNI was studied in three segments and it showed variation in length. Blood supply to the sciatic nerve was assisted by the nutrient branches from trochanteric & cruciate anastomosis in 71% of cases, and branches from the artery accompanying the posterior cutaneous nerve of the thigh in 34% of cases. Both sources assisted blood supply in 3% of cases. Detailed knowledge of blood supply to the peripheral nerve is essential for surgeons dealing with peripheral nerve injuries

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Unusual relationship between the piriform muscle and sciatic, inferior gluteal and posterior femoral cutaneous nerves / Relación inusual entre el músculo piriforme y los nervios isquiático, glúteo inferior y cutâneo femoral posterior

Piriformis muscle syndrome has been increasingly recognized as a cause of leg pain. Overuse, strain, or anatomical variations of the relationship between the nerve and the piriformis muscle are thought to be the underlying causes of the entrapment of the sciatic nerve. We report a variation not previously described which was found during a routine dissection. During routine dissection of the left gluteal region of an adult male cadaver we observed a high division of the sciatic nerve and the presence of an accessory piriformis muscle. The sciatic nerve divided beneath the piriformis muscle and the common fibular nerve passed over the accessory piriformis muscle, whereas the tibial nerve reflected anteriorly to pass between the accessory piriformis and the superior gemellus muscle. Additionally, both nerves communicated with a side branch under the inferior border of the accessory piriformis muscle and the inferior gluteal nerve originated from the fibular nerve. Anatomical variations in the relationship between the piriformis muscle and the sciatic nerve may be present in up to 17% of the population. Six different variations have been described and none of them is similar to our description. Though complete understanding of the physiopathology of the piriformis muscle syndrome remains to be elucidated, knowledge of the possible anatomical variations may be useful for its adequate diagnosis and treatment.

El síndrome del músculo piriforme se ha reconocido cada vez más como una causa de dolor en los miembros inferiores. Tensión excesiva o variaciones anatómicas del nervio y del músculo piriforme se cree son las causas subyacentes de pinzamiento del nervio isquiático. Se presenta una variación no descrita anteriormente. Durante una disección de rutina en un cadáver de sexo masculino, se observó una división más alta del nervio isquiático y la presencia de un músculo piriforme accesorio. El nervio isquiático se dividía bajo el músculo piriforme y el nervio fibular común pasaba sobre el músculo piriforme accesorio. Por otra parte, el nervio tibial cruzaba entre los músculos piriforme accesorio y gemelo superior. Además, ambos nervios se comunicaban con un ramo lateral bajo el margen inferior del músculo piriforme accesorio y el nervio glúteo inferior se originaba desde el nervio fibular. Variaciones anatómicas y relaciones entre el músculo piriforme y nervio isquiático pueden estar presentes hasta en el 17% de la población. Seis variaciones diferentes se han descrito en este artículo y ninguna es similar a nuestra descripción. A pesar del completo entendimiento de la fisiopatología del síndrome del músculo piriforme, aún queda por esclarecer y conocer las posibles variaciones anatómicas que pueden ser útiles tanto para su diagnóstico como para el tratamiento adecuado.

Aspectos anatómicos y topográficos del nervio pudendo en la región glútea / Anatomical and topographical aspects of the pudendal nerve in gluteal region

El nervio pudendo distribuye ramos motores y sensitivos para la región perineal y órganos genitales externos. Tiene importancia funcional en la micción, defecación, erección y parto. Desde el punto de vista clínico, se realiza bloqueo anestésico del mismo en la práctica obstétrica, se electroestimula en casos de incontinencia fecal o urinaria, entre otros procedimientos. Investigaciones anatómicas han señalado que puede presentar variaciones en su conformación y topografía. Con el propósito de complementar el conocimiento sobre este nervio en su trayecto por la región glútea, se estudió su conformación, biometría y relaciones con los vasos pudendos internos y ligamentos adyacentes. Se disecaron 30 regiones glúteas de 15 cadáveres formolizados de individuos brasileños, adultos, de ambos sexos, observando la conformación del nervio, número de ramos, disposición respecto a los vasos pudendos internos y ligamentos sacrotuberoso y sacroespinoso, registrando también su ancho en el trayecto entre los forámenes isquiático mayor y menor. El nervio pudendo se presentó como tronco único en 53,3 por ciento de los casos y dividido en ramos en 46,7 por ciento (dos ramos en 36,7 por ciento, tres en 6,7 por ciento y cuatro en 3,3 por ciento). Cuando estaba dividido, en 36,7 por ciento los ramos permanecieron separados y en 10 por ciento se unieron antes de ingresar en el foramen isquiático menor. El nervio (único o dividido) fue medial a los vasos pudendo internos en 70 por ciento y lateral a ellos en 3,3 por ciento. En el 26,7 por ciento restante, estaba dividido en dos o tres ramos, que se situaban medial y lateralmente a los vasos o los cruzaban posteriormente. Su posición fue anterior al ligamento sacrotuberoso en 93,3 por ciento. El nervio pudendo presenta interesantes variaciones en su conformación y topografía, que deben ser consideradas durante los procedimientos clínicos y quirúrgicos que lo involucren.

The pudendal nerve distributes motor and sensory branches to the perineum and genital external organs. It has functional importance in the micturition, defecation, erection and labor. From the clinical point of view, anaesthetic blockade of the same one is realized in the obstetric practice, electroestimulation in cases of fecal or urinary incontinence, among other procedures. Anatomical investigations have indicated that it can present variations in its conformation and topography. The objective of this study was complete knowledge about this nerve in its course through the gluteal region, its conformation, biometry and its relationship with the internal pudendal vessels and adjacent ligaments were studied. We dissected 30 gluteal regions of 15 corpses fixed in formaldehyde 10 percent of Brazilian individuals, adult, of both sexes, observing the conformation of the nerve, number of branches, disposition with regard to the internal pudendal vessels and sacrotuberous and sacrospinous ligaments, also recording its external diameter in the distance between greater sciatic foramen and lesser sciatic foramen. The pudendal nerve appeared as a single trunk in 53.3 percent of the cases and divided in branches in 46.7 percent (two branches in 36.7 percent, three in 6.7 percent and four in 3.3 percent). When it was divided, in 36,7 percent the branches remained separated and in 10 percent they joined before the lesser sciatic foramen. The nerve (single or divided) was medial to the internal pudendal vessels in 70 percent and lateral to them in 3.3 percent. In 26.7 percent, it was divided in two or three branches, which were located medially and laterally to these vessels or crossing posterior to them. Its position was anterior to the sacrotuberous ligament in 93.3 percent. The pudendal nerve presents interesting variations in its conformation and topography which must be considered during the clinical and surgical procedures.

L4-L5-S1 human dermatomes: a clinical, electromyographical, imaging and surgical findings / Dermátomos humanos L4, L5 e S1: achados clínicos, eletromiográficos, de imagem e cirúrgicos

There is substantial controversy in literature about human dermatomes. We studied L4, L5, and S1 inferior limb dermatomes by comparing clinical signs and symptoms with conduction studies, electromyographical data, neurosurgical findings, and imaging data from computerized tomography (CT) or magnetic resonance imaging (MRI). After analyzing 60 patients, we concluded that L4 is probably located in the medial aspect of the leg, L5 in the lateral aspect of the leg and foot dorsus, and S1 in the posterior aspect of the backside, tight, leg and plantar foot skin. This is the first time that these human dermatomes have been evaluated by combined analysis of clinical, electromyographical, neurosurgical, and imaging data.

Há controvérsia na literatura sobre os dermátomos humanos. Estudamos dermátomos do membro inferior comparando sinais e sintomas com estudos eletromiográficos, de imagem e achados cirúrgicos. Analisando 60 pacientes, concluímos que o dermátomo L4 provavelmente está localizado na região medial da perna, o dermátomo L5 na região lateral da perna e dorso do pé, e o dermátomo S1 na nádega, região posterior da coxa e da perna e na região plantar. Este é o primeiro estudo que os dermátomos do membro inferior foram analisados através de dados clínicos, eletromiográficos, imagem e achados cirúrgicos.

Colgajos de perforantes de arteria glútea superior y arteria glútea inferior / Gluteal artery perforator flaps: S-GAP and I-GAP

En la actualidad la transferencia de tejido ha evolucionado hasta el nivel de los colgajos de perforantes, los cuales aportan tejido formado por piel y grasa, con la mínima morbilidad a nivel de la zona donante. Los colgajos de perforantes de la región glútea, de arteria glutea superior (S-GAP) y de arteria glútea inferior (I-GAP), han ganado popularidad debido a su fiabilidad, preservación del músculo, versatilidad en el diseño sin comprometer otras alternativas reconstructivas y por su baja morbilidad. Se analizarán en este artículo de forma detallada la anatomía, técnica quirúrgica e indicaciones específicas de estos colgajos de perforantes de la región glútea (AU)

The evolution of free tissue transfer has progressed to the level of the perforator flaps. They allow the transfer of the patient´s own skin and fat in a reliable way with minimal donor-site morbidity. Nowadays the gluteal artery perforator flaps, superior (S-GAP) and inferior (I-GAP), have gained popularity due to reliability, preservation of the muscle, versatility in flap design without restricting other flap options, and lower donor-site morbidity. Anatomy of the gluteal region, flap raising technique and specific indications will be well-described (AU)

Trayecto del nervio gluteo inferior asociado a la división alta del nervio isquiático / Inferior gluteal nerve course associated to the high division of the sciatic nerve

El nervio glúteo inferior, ramo del plexo sacro, abandona la pelvis pasando generalmente por debajo del músculo piriforme. De este plexo se origina también el nervio isquiático, el cual puede presentar variaciones en su relación con el músculo mencionado, entre ellas, las que se refieren a la division alta del mismo. Sin embargo, son escasos los trabajos que correlacionen esta división con el trayecto del nervio glúteo inferior y su relación con el músculo iriforme. Con el propósito de verificar una posible asociación entre los trayectos de estos nervios, fueron disecadas 80 regiones glúteas de cadáveres de individuos brasileños adultos en el Departamento de Morfología de la Universidade Federal de Sao Paulo. Se encontraron dos tipos de variación entre el nervio isquiático y el músculo piriforme: en 9 casos (11,2 por ciento) el nervio fibular común pasó a través del músculo y el nervio tibial transcurrió por debajo de su margen inferior (Tipo I); en dos casos (2,5 por ciento), correspondientes a un mismo individuo, el nervio fibular común hizo su trayecto por sobre el margen superior del músculo piriforme y el nervio tibial pasó por debajo de su margen inferior (Tipo II). En el tipo I, el nervio glúteo inferior pasó a través del músculo en 65 casos y en los 3 restantes una parte del nervio perforó al músculo y la otra pasó por debajo de su margen inferior; en el tipo II, el nervio glúteo inferior transcurrió por debajo del margen inferior del músculo en uno de los casos y en el otro, una parte de este nervio se originó del nervio fibular común y la otra, pasó por debajo del margen inferior del músculo. El trayecto del nervio glúteo inferior a través del músculo piriforme podría estar relacionado con la atrofia glútea observada en los pacientes con síndrome del músculo piriforme

Síndrome neurológico transitorio tras bupivacaína hiperbara intradural. Un nuevo caso / Transient neurological syndrome after spinal hyperbaric bupivacaine: a new case

Paciente de 47 años sometida a histeroscopia y exéresisde pólipo endometrial por metrorragias de seis mesesde evolución. El procedimiento se llevó a cabo bajo anestesiaintradural. No hubo incidencias durante la punción,el intra ni el postoperatorio inmediato. La recuperacióndel bloqueo sensitivo y motor fue normal. A las 24horas de la cirugía comenzó con dolor y disestesias englúteos y miembros inferiores, sin déficit sensitivo nimotor. La clínica era sugerente de síndrome neurológicotransitorio.El síndrome neurológico transitorio (TNS) ha sidodefinido como dolor en los miembros inferiores, nalgas,muslos y piernas tras una anestesia espinal sin complicacionesy tras una recuperación completa del bloqueosensitivo-motor durante el periodo postoperatorio inmediato(antes de las primeras 24 horas). El curso es autolimitadoy no permanece secuela neurológica alguna.Los últimos estudios han demostrado cambios bioquímicosy anatomopatológicos que aportan una baseestructural a la entidad clínica de TNS. Según algunosautores TNS podría ser la menor expresión de la toxicidadpor anestésicos locales. Hallazgos recientes demuestranque el daño inicial en la membrana de la célula nerviosa,inducida por altas concentraciones de anestésicolocal, podría desembocar en un daño neuronal permanente

A 47-year-old woman underwent hysteroscopy andremoval of an endometrial polyp because of irregular, acyclicbleeding of 6 months’ duration. The procedure wascarried out under spinal anesthesia. No adverse eventsoccurred during puncture or surgery, or in the immediatepostoperative recovery period. Recovery from the sensoryand motor block was normal. Twenty-four hours after surgerygluteal and lower limb pain and paresthesia developed,with no sensory or motor deficit. The symptoms suggestedtransient neurological syndrome.This syndrome has been defined by pain in the lowerlimbs, buttocks, thighs and calves after uncomplicatedspinal anesthesia and full recovery from the sensorimotorblock during the immediate postoperative period(first 24 hours). The condition is self-limiting and doesnot leave permanent neurological sequelae.Recent studies have demonstrated biochemical andanatomical changes that provide a structural basis forthis clinical entity. According to this literature, transientneurological syndrome might be a mild expression oflocal anesthetic toxicity. Recent findings show that theinitial injury to the nerve cell membrane, induced byhigh concentrations of local anesthetic could lead to permanentneuronal damage