Evaluation of the implantation of transpedicular screws in spinal instrumentation with free-hand technique and navigation-assisted with intraoperative computed tomography: An analytical-positional study.

BACKGROUND: Spinal instrumentation using transpedicular screws has been used for decades to stabilize the spine. In October 2018, an intraoperative CT system was acquired in the Neurosurgery service of the University Hospital Complex of Vigo, this being the first model of these characteristics in the Spanish Public Health System, so we began a study from January 2015 to December 2019 to assess the precision of the transpedicular screws implanted with this system compared with a control group performed with the classical technique and final fluoroscopic control. METHODS: The study was carried out in patients who required transpedicular instrumentation surgery, in total 655 screws were placed, 339 using the free-hand technique (Group A) and 316 assisted with intraoperative CT navigation (Group B) (p>0.05). Demographic characteristics, related to surgery and the screw implantation grades were assessed using the Gertzbein-Robbins classification. RESULTS: 92 patients were evaluated, between 12 and 86 years (average: 57.1 years). 161 thoracic screws (24.6%) and 494 lumbo-sacral screws (75.4%) were implanted. Of the thoracic screws, 33 produced a pedicle rupture. For the lumbo-sacral screws, 71 have had pedicle violation. The overall correct positioning rate for the free-hand group was 72.6% and for the CT group it was 96.5% (p<0.05). CONCLUSION: The accuracy rate is higher in thoracic-lumbar instrumentation in the navigation group versus free-hand group with fluoroscopic control.

Evaluation of the implantation of transpedicular screws in spinal instrumentation with free-hand technique and navigation-assisted with intraoperative computed tomography: An analytical-positional study.

BACKGROUND: Spinal instrumentation using transpedicular screws has been used for decades to stabilize the spine. In October 2018, an intraoperative CT system was acquired in the Neurosurgery service of the University Hospital Complex of Vigo, this being the first model of these characteristics in the Spanish Public Health System, so we began a study from January 2015 to December 2019 to assess the precision of the transpedicular screws implanted with this system compared with a control group performed with the classical technique and final fluoroscopic control. METHODS: The study was carried out in patients who required transpedicular instrumentation surgery, in total 655 screws were placed, 339 using the free-hand technique (Group A) and 316 assisted with intraoperative CT navigation (Group B) (p>0.05). Demographic characteristics, related to surgery and the screw implantation grades were assessed using the Gertzbein-Robbins classification. RESULTS: 92 patients were evaluated, between 12 and 86 years (average: 57.1 years). 161 thoracic screws (24.6%) and 494 lumbo-sacral screws (75.4%) were implanted. Of the thoracic screws, 33 produced a pedicle rupture. For the lumbo-sacral screws, 71 have had pedicle violation. The overall correct positioning rate for the free-hand group was 72.6% and for the CT group it was 96.5% (p<0.05). CONCLUSION: The accuracy rate is higher in thoracic-lumbar instrumentation in the navigation group versus free-hand group with fluoroscopic control.

Hemangiopericytoma/Solitary Fibrous Tumor in the central nervous system. Experience with surgery and radiotherapy as a complementary treatment: A 10-year analysis of a heterogeneous series in a single tertiary center / Hemangiopericitoma/tumor fibroso solitario en el sistema nervioso central. Experiencia con Cirugía y Radioterapia como tratamiento complementario: un análisis de 10 años sobre una serie heterogénea en un centro terciario

Hemangiopericytoma and Solitary Fibrous Tumor are tumors with low incidence. They have a tendency to recur locally and to metastasize. The WHO integrated both tumors into a new entity but one of the pending issues is to demonstrate the effectiveness of surgery plus complementary radiotherapy (RT) and standardize the use of it. We reviewed the data from 10 years. We assessed pathologic and radiologic characteristics. The operation records were evaluated to determine the features and extent of tumor resection. We compared the outcomes in patients using or not RT. The mean follow-up was 74.8 months, with a range of 12 and 210 months. The population included 3 males (30%) and 7 females (70%). The most common location was brain convexity (30%), the remaining were cervical and lumbar spine, sacrum, intraventricular, torcular, sphenoid ridge and intraorbital. Postoperative external beam radiotherapy was delivered in 7 patients (70%), the criteria were a partial resection or WHO II and III histological grades.2 patients developed local recurrences at 12 and 19 months after initial surgery.1 patient underwent 2 surgeries, and the other, 4 surgeries. The mean recurrence free survival rate was 15.5 months. Distant metastases were found in 4 PATIENTS: 3 of the 10 patients died. Five-year overall survival rate was 66% and mean overall survival was 76 months. A safe and complete resection in the first surgery is the most important prognostic factor.complementary RT can be helpful, even in cases of complete resection in WHO low-grade

El hemangiopericitoma y el tumor fibroso solitario son enfermedades del sistema nervioso central (SNC) con una incidencia baja. Estos tumores también pueden tener algunas características como una tendencia a recurrir localmente y hacer metástasis. La OMS, en su última clasificación de tumores del SNC, integró ambos tumores en una nueva entidad: tumor fibroso solitario/hemangiopericitoma (SFT/HPC), pero uno de los problemas actuales pendientes es demostrar la efectividad de la cirugía y la radioterapia (RT) complementaria, y estandarizar el uso de la misma. Revisamos todos los datos clínicos de nuestro hospital en un período de 10 años, y encontramos 10 pacientes con SFT/HPC. Se evaluaron los tamaños de los tumores, las ubicaciones y las características radiológicas. Los registros quirúrgicos de cada paciente se evaluaron para determinar las características macroscópicas y el alcance de la resección del tumor (EOR). También comparamos los resultados en los pacientes que utilizan o no RT como tratamiento complementario. El seguimiento medio fue de 74,8 meses, con un rango de 12 y 210 meses. La población incluía 3 varones (30%) y 7 mujeres (70%). La localización más frecuente fue la convexidad cerebral (30%). Las distribuciones de las localizaciones restantes del tumor fueron columna cervical y lumbar, sacro, intraventricular, torcular, ala esfenoidal e intraorbitario. La radioterapia postoperatoria (EBRT) se administró en 7 pacientes (70%), los criterios para tratarlos fueron una resección parcial o un grado histológico de la OMS II y III. Dos pacientes desarrollaron recidivas locales a los 12 y 19 meses después de la cirugía inicial. Un paciente se sometió a 2 cirugías, y el otro a 4 cirugías. La tasa media de supervivencia libre de recidiva (RFS) fue de 15,5 meses. Se encontraron metástasis a distancia en 4 pacientes durante el período de seguimiento. Tres de los 10 pacientes fallecieron durante el período de seguimiento. La tasa de supervivencia general a 5 años fue del 66%, y la supervivencia media global fue de 76 meses. Una resección segura y completa en la primera cirugía es el factor pronóstico más importante. Consideramos que la RT complementaria puede ser útil, incluso en casos de resección completa en SFT/HPC de bajo grado. Sería interesante definir previamente la diferenciación entre el SFT/HPC y los meningiomas para las estrategias de tratamiento

Hemangiopericytoma/Solitary Fibrous Tumor in the central nervous system. Experience with surgery and radiotherapy as a complementary treatment: A 10-year analysis of a heterogeneous series in a single tertiary center.

Hemangiopericytoma and Solitary Fibrous Tumor are tumors with low incidence. They have a tendency to recur locally and to metastasize. The WHO integrated both tumors into a new entity but one of the pending issues is to demonstrate the effectiveness of surgery plus complementary radiotherapy (RT) and standardize the use of it. We reviewed the data from 10 years. We assessed pathologic and radiologic characteristics. The operation records were evaluated to determine the features and extent of tumor resection. We compared the outcomes in patients using or not RT. The mean follow-up was 74.8 months, with a range of 12 and 210 months. The population included 3 males (30%) and 7 females (70%). The most common location was brain convexity (30%), the remaining were cervical and lumbar spine, sacrum, intraventricular, torcular, sphenoid ridge and intraorbital. Postoperative external beam radiotherapy was delivered in 7 patients (70%), the criteria were a partial resection or WHO II and III histological grades. 2 patients developed local recurrences at 12 and 19 months after initial surgery. 1 patient underwent 2 surgeries, and the other, 4 surgeries. The mean recurrence free survival rate was 15.5 months. Distant metastases were found in 4 patients. 3 of the 10 patients died. Five-year overall survival rate was 66% and mean overall survival was 76 months. A safe and complete resection in the first surgery is the most important prognostic factor. Complementary RT can be helpful, even in cases of complete resection in WHO low-grade.

Quistes aracnoideos del sistema nervioso central. Algoritmos y recomendaciones generales de manejo / Arachnoid cysts of the central nervous system. Algorithms and recommendations for management

La sintomatología relacionada con la presencia de quistes aracnoideos en el sistema nervioso central dependerá del tamaño del quiste y de su velocidad de crecimiento, su localización y, en algunos casos, de la posible alteración de dinámica de LCR asociada. En ocasiones la clínica se presenta de forma brusca por rotura del quiste o sangrado agudo. Aunque se acepta de forma general que los quistes asintomáticos o paucisintomáticos no precisan tratamiento quirúrgico, no existe consenso respecto a la actitud terapéutica de elección en los casos sintomáticos. El objetivo del presente trabajo es el de revisar la literatura analizando los pros y contras de las 3 opciones quirúrgicas principales (microcirugía, neuroendoscopia y derivación de LCR) en función principalmente de la localización de la lesión. Aunque el tratamiento debe ser siempre individualizado para cada caso, pueden ofrecerse unas recomendaciones generales de manejo

The symptoms related to the presence of arachnoid cysts in the Central Nervous System depend on the size of the cyst and its growth rate, its location and, in some cases, the associated CSF dynamic disorder. Sometimes there is acute clinical presentation due to cyst rupture or acute bleeding. Although it is generally accepted that asymptomatic or paucisymptomatic cysts do not require surgical treatment, there is no consensus on the therapeutic approach of choice in symptomatic cases. The aim of this paper is to review the literature, analyzing the pros and cons of the three main surgical options (microsurgery, neuroendoscopy, and CSF shunt) based primarily on the location of the cyst. Although treatment must be always individualized, basic management recommendations may be offered

[Arachnoid cysts of the central nervous system. Algorithms and recommendations for management]. / Quistes aracnoideos del sistema nervioso central. Algoritmos y recomendaciones generales de manejo.

The symptoms related to the presence of arachnoid cysts in the Central Nervous System depend on the size of the cyst and its growth rate, its location and, in some cases, the associated CSF dynamic disorder. Sometimes there is acute clinical presentation due to cyst rupture or acute bleeding. Although it is generally accepted that asymptomatic or paucisymptomatic cysts do not require surgical treatment, there is no consensus on the therapeutic approach of choice in symptomatic cases. The aim of this paper is to review the literature, analyzing the pros and cons of the three main surgical options (microsurgery, neuroendoscopy, and CSF shunt) based primarily on the location of the cyst. Although treatment must be always individualized, basic management recommendations may be offered.

Ethmoidal meningoencephalocele and CSF leak after posthaemorrhagic ventricular dilatation in a newborn child.

BACKGROUND: Rhinoliquorrhoea suggests a communication between the subarachnoid space and the sinonasal tract. Clinical presentation includes clear nasal discharge, headache, pneumocephalus, meningitis or brain abscess. Cerebrospinal fluid (CSF) leaks are mostly of traumatic origin (skull base fractures), iatrogenic (secondary to endoscopic endonasal surgery) or associated with tumour aetiology. Occasionally, hydrocephalus has been the cause of rhinoliquorrhoea in adults, presumably secondary to the chronically raised intracranial pressure with skull base erosion and meningocele. To our knowledge, the association of hydrocephalus and ethmoid meningoencephalocele/CSF leak has not been previously reported in a newborn child. CASE PRESENTATION: We present the case of a 9-month-old girl who was referred for rhinorrhoea. She had a history of posthaemorrhagic ventricular dilatation. Brain computed tomography (CT) and magnetic resonance imaging (MRI) showed a left ethmoidal meningoencephalocele and small ventricular size. The meningoencephalocele was surgically repaired using an intradural subfrontal approach. During the postoperative period, after the transient lumbar drain was withdrawn, she developed symptomatic hydrocephalus. Ventriculoperitoneal shunting was required. CONCLUSION: Progressive ventricular dilatation may arise from a meningoencephalocele/CSF leak in paediatric patients. Early identification and repair of the meningoencephalocele are critical to avoid development of complications.

Hernias encefálicas. Clasificación, neuropatología y problemas medicolegales / Brain herniations. Classification, Neuropathology and medico-legal problems

Las hernias cerebrales son la causa inmediata del fallecimiento en muchas lesiones neurológicas. Algunos protocolos recientes de actuación neuroquirúrgica han originado nuevas modalidades, como por ejemplo en el llamado síndrome del trefinado. Se requiere, pues, una revisión actualizada del tema, máxime cuando tiene importantes implicaciones medicolegales. Nuestro objetivo es revisar las clasificaciones, adaptarlas a los avances en Neurorradiología y Neurocirugía, y analizar su problemática medicolegal. La actualización de la clasificación y un conocimiento detallado de la fisiopatología de las hernias cerebrales constituyen la mejor orientación para la resolución de problemas forenses en lo relativo a etiología, causalidad y secuelas de las lesiones encefálicas (AU)

Brain herniation is the immediate cause of death in most of neurological lesions. Some recent neurosurgical protocols have promoted new kinds of herniation, like those that occur in the so-called syndrome of the threphined. Therefore, an up-to-date revision of this subject is required in regard of its important medico-legal implications. Our aim is to review the present classifications, adapting them to Neuroimaging and Neurosurgical advances, and analyzing the medical-legal issues of brain herniation. The problems extend not only to Pathology, but also to Clinical Forensic subjects. An up-to-date classification and a more detailed knowledge of the brain herniations physiology and pathology are the best tools to address their forensic problems, in particular those related with etiology, causation and sequels of brain lesions (AU)

Dispositivos interespinosos y hernia discal. Estudio morfogeométrico y clínico de 71 casos tratados con microdiscectomía L4-L5 asociada a colocación de espaciador / Interspinous spacers and disc herniation. Geomorphometric and clinical study of 71 cases treated by L4-L5 microdiscectomy associated to spacer placement

Objetivo: Una indicación controvertida de los espaciadores interespinosos es su utilización complementaria a la discectomía. Actualmente, no existen evidencias sólidas de la eficacia de dicha asociación, lo que podría derivar de la variabilidad en la colocación del espaciador, limitando su labor biomecánica. El presente trabajo busca identificar y analizar la variabilidad de emplazamiento de un espaciador interespinoso, y determinar su relación con el resultado clínico. Material y método: Se estudiaron 71 casos de hernia discal L4-L5 intervenidos en nuestro hospital mediante discectomía y colocación de espaciador interespinoso. Se utilizaron técnicas de morfometría geométrica: análisis procrustes y componentes principales. Se comparan los resultados morfológicos con la lordotización, distracción quirúrgica, así como con variables clínicas (índice de Herron y Turner). Resultados: Se identificó significativa variabilidad morfológica tanto en forma de traslación cráneo-caudal como rotación horaria-antihoraria en la posición del implante. Esta variación no se correlacionó con el resultado clínico, pero sí con variables anatómicas (grado de lordosis), y con aspectos quirúrgicos (distracción adicional del implante). Se detectó, igualmente, un emplazamiento ligeramente diferente en los casos con recidiva. Conclusiones: La morfometría geométrica permite objetivar una elevada variabilidad morfológica en el emplazamiento de los espaciadores interespinosos, que, sin embargo, no parece influir en el resultado clínico, dependiendo más bien del grado de lordosis y distracción. Se apreciaron diferencias de emplazamiento en los casos que recidivaron. Para valorar la eficacia de los espaciadores como complemento de la cirugía discal se requieren estudios con mayor número de casos, que necesariamente deben incluir análisis de variables morfológicas

Objective: A controversial indication of interspinous spacers is their use as a complement to discectomy. At the present time, there is no solid clinical evidence of effectiveness of that association, which might result from variability in spacer positioning, restricting its correct biomechanical actions. In this study our goal was to identify and analyse the variability in the placement of an interspinous spacer, and to investigate its relationship with the clinical results. Materials and methods. We performed a retrospective study on X-ray films from 71 patients suffering from disc herniation in L4-L5 who underwent surgery in our hospital, consisting of: microdiscectomy and biomed interspinous spacer implantation. The geomorphometric techniques used to analyse the data were procrustes superimposition and principal components analysis. We compared the clinical results (using the Herron and Turner scale), segmental lordosis and surgical distraction with the geomorphometric parameters. Results. Significant morphological variability was found in the implant position showing cephalo-caudal translation and clockwise-counterclockwise rotations. This variability did not correlate with clinical results. A relationship with anatomical features (lordosis) and additional surgical distraction was identified. A different morphology of implant-segment configuration was identified in cases with recurrence of disc herniation. Conclusions: Geometric morphometrics allowed identifying high variability in the final placement of interspinous spacers. Nevertheless, it seems not to be related to the clinical outcome, depending rather on the degree of lordosis and distraction. Some differences in segment-implant morphology were identified in cases with recurrences. To assess the effectiveness of spacers, larger studies including morphological and clinical variables are required

Endoscopic endonasal resection of clival xanthoma: case report and literature review.

Bone xanthoma is an extremely rare and benign tumor in terms of its nature and growth over time. We describe the first case coexisting with ventriculomegaly secondary to aqueduct stenosis (non-tumoral hydrocephalus), the second xanthoma of the clivus described to date. The patient was a 51-year-old woman with headaches and absence seizures. Axial T1-weighted MRI showed a well-demarcated, hypointense, osteolytic, 25 × 18 × 15 mm lesion with cortical erosion located at the right margin of the clivus. Sagittal T2-weighted MRI demonstrated a hypointense mass without associated edema. Sagittal gadolinium-enhanced T1-weighted MRI showed contrast uptake with a partially hypointense rim. The increased ventricular size without periventricular edema was associated with aqueduct stenosis, and there was no contiguity with the tumor. A neuronavigation image-guided transsphenoidal approach was chosen to perform a macroscopically complete resection. Intraoperative histopathological study showed a chordoma of the clivus. Exhaustive postsurgical study revealed the benign nature of a bone xanthoma. Given the finding of a clival lesion, the differential diagnosis is essentially with other malignant entities with a rapidly fatal outcome, such as metastases, or with a possible invasive evolution, such as clivus chordomas. This report describes the clinical, radiological, and pathological keys for such differentiation in order to avoid unnecessarily aggressive treatment with ablative surgery and radiotherapy.

[Interspinous spacers and disc herniation. Geomorphometric and clinical study of 71 cases treated by L4-L5 microdiscectomy associated to spacer placement]. / Dispositivos interespinosos y hernia discal. Estudio morfogeométrico y clínico de 71 casos tratados con microdiscectomía L4-L5 asociada a colocación de espaciador.

OBJECTIVE: A controversial indication of interspinous spacers is their use as a complement to discectomy. At the present time, there is no solid clinical evidence of effectiveness of that association, which might result from variability in spacer positioning, restricting its correct biomechanical actions. In this study our goal was to identify and analyse the variability in the placement of an interspinous spacer, and to investigate its relationship with the clinical results. MATERIALS AND METHODS: We performed a retrospective study on X-ray films from 71 patients suffering from disc herniation in L4-L5 who underwent surgery in our hospital, consisting of: microdiscectomy and biomed interspinous spacer implantation. The geomorphometric techniques used to analyse the data were procrustes superimposition and principal components analysis. We compared the clinical results (using the Herron and Turner scale), segmental lordosis and surgical distraction with the geomorphometric parameters. RESULTS: Significant morphological variability was found in the implant position showing cephalo-caudal translation and clockwise-counterclockwise rotations. This variability did not correlate with clinical results. A relationship with anatomical features (lordosis) and additional surgical distraction was identified. A different morphology of implant-segment configuration was identified in cases with recurrence of disc herniation. CONCLUSIONS: Geometric morphometrics allowed identifying high variability in the final placement of interspinous spacers. Nevertheless, it seems not to be related to the clinical outcome, depending rather on the degree of lordosis and distraction. Some differences in segment-implant morphology were identified in cases with recurrences. To assess the effectiveness of spacers, larger studies including morphological and clinical variables are required.

Plexopatía braquial compresiva por necrosis grasa encapsulada supraclavicular. Caso clínico / Brachial plexus compression from supraclavicular encapsulated fat necrosis. A case report

Se presenta el caso clínico de un varón de 44 años de edad, sin antecedentes de interés, intervenido quirúrgicamente en nuestro servicio de una lesión ocupante de espacio supraclavicular diagnosticada tras un cuadro de un mes de evolución de paresia distal progresiva del miembro superior izquierdo. Tras el análisis histológico de la lesión resecada el diagnóstico fue de necrosis grasa encapsulada. Dicha entidad se caracteriza a nivel histológico por presentar una estructura quística, encapsulada, con necrosis grasa en su interior e infiltrado inflamatorio en su pared. La compresión de estructuras nerviosas secundaria a esta lesión tumoral es excepcional, la cual suele localizarse en miembros inferiores, especialmente en zonas expuestas a traumatismos. En el presente trabajo se expone el primer caso descrito de compresión supraclavicular del plexo braquial a consecuencia de una necrosis grasa

We report the case of a 44-year-old male, lacking clinical history of previous illness, who had surgery at our hospital to treat a mass in the supraclavicular space. The patient presented with a 1-month progressive distal paresis of the left arm. The histo-pathological examination of the mass revealed an encapsulated fat necrosis. Fat necrosis is characterised bycystic architecture, encapsulation with fat necrosis within, and inflammatory infiltration of its walls. Neural structure compression secondary to this tumour mass is very rare. Fatnecrosis is more frequent in the lower limbs, in areas exposed to trauma. This article is the first report of brachial plexus compression due to supraclavicular fat necrosis

[Brachial plexus compression from supraclavicular encapsulated fat necrosis. A case report]. / Plexopatía braquial compresiva por necrosis grasa encapsulada supraclavicular. Caso clínico.

We report the case of a 44-year-old male, lacking clinical history of previous illness, who had surgery at our hospital to treat a mass in the supraclavicular space. The patient presented with a 1-month progressive distal paresis of the left arm. The histo-pathological examination of the mass revealed an encapsulated fat necrosis. Fat necrosis is characterised by cystic architecture, encapsulation with fat necrosis within, and inflammatory infiltration of its walls. Neural structure compression secondary to this tumour mass is very rare. Fat necrosis is more frequent in the lower limbs, in areas exposed to trauma. This article is the first report of brachial plexus compression due to supraclavicular fat necrosis.

Fascitis craneal: caso clínico y revisión de la literatura / No disponible

La fascitis craneal es una lesión miofibroblástica benigna infrecuente, de rápido crecimiento, localizada en el cráneo y de aparición preferente en niños durante el primer año de vida. Histológicamente es similar a la fascitis nodular o a la fascitis seudosarcomatosa. Puede mimetizar patologías más agresivas, como histiocitosis o sarcomas, por su rápido crecimiento de forma nodular en el tejido subcutáneo. La resección completa se considera curativa y tiene bajo riesgo de metástasis o de malignización. En el presente trabajo se presenta el caso de un varón de 4 años con fascitis en tejido celular subcutáneo craneal con erosión de la tabla externa y reacción perióstica circundante, respetando las meninges. El objetivo de este trabajo es destacar la ausencia de necesidad de tratamiento adyuvante con radioterapia o quimioterapia. Se lleva a cabo, además, una revisión de la literatura (AU)

[Cranial fasciitis: a case report and review of the literature]. / Fascitis craneal: caso clínico y revisión de la literatura.

Cranial fasciitis is an uncommon, rapidly-growing, benign, non-tumoural, myofibroblastic lesion of the skull, found mainly among young children in their first year of life. It is histologically similar to nodular fasciitis and pseudosarcomatous fasciitis. It may mimic more aggressive pathologies, such as sarcomatosis or histiocytosis, due to its rapid, nodular growth in subcutaneous tissue. Complete resection is considered curative and, therefore, entails a low risk of metastases or malignant recurrences. We present the clinical, radiological and pathological findings in a 4-year-old boy with cranial fasciitis in the deep, subcutaneous, soft tissue, with erosion of the outer table of the cranium, which also produced periosteal reaction, while respecting the inner table and meninges. The objective of this article is to highlight the absence of radiotherapeutic or chemotherapeutic adjuvant treatment. In addition, an exhaustive review of the literature is also presented.

Ciatalgia secundaria a endometriosis extrapélvica del músculo piriforme. A propósito de un caso / No disponible

Objetivos Mostrar un caso de compresión sintomática del nervio ciático derecho a nivel de la escotadura ciática secundaria a una endometriosis en el músculo piriforme y realizar una revisión de los casos publicados en la literatura. Material y métodos Se presenta el caso de una paciente de 29 años con un cuadro de ciática derecha crónica de 2 años de evolución: el primer año episódica y coincidente con la menstruación, el segundo año constante y con un trastorno de la marcha por debilidad de la musculatura dependiente del músculo ciático. Como causa de la mononeuropatía (demostrada por estudio neurofisiológico) se objetivó en RM y PET una masa a nivel de la escotadura ciática con un aumento del metabolismo de las estructuras adyacentes. Con la finalidad de liberar el nervio y obtener muestra para diagnóstico histológico se decidió intervenir quirúrgicamente a la paciente. Resultados Se procedió a un abordaje transglúteo, neurólisis externa del nervio ciático y resección de un (..) (AU)

[Sciatica secondary to extrapelvic endometriosis affecting the piriformis muscle. Case report]. / Ciatalgia secundaria a endometriosis extrapélvica del músculo piriforme. A propósito de un caso.

OBJECTIVE: We present a case report of symptomatic compression of the right sciatic nerve notch, secondary to piriformis muscle endometriosis, as well as a literature review. MATERIAL AND METHODS: We report the case of a 29-year-old woman with 2-year evolution of right chronic sciatica. During the first year, symptoms were episodic and associated with menstruation. During the second year, sciatica was constant and associated with gait disorder due to sciatic musculature weakness. Mononeuropathy was proved by a neurophysiological study, with MRI and PET studies revealing a mass in the sciatic notch and regional pathological increase in metabolic activity. Surgical treatment was performed in order to release the nerve and obtain a histological sample. RESULTS: The patient was treated by a transgluteal approach, with external neurolysis of the sciatic nerve and resection of an old-blood cyst at the level of the piriformis muscle. This was subsequently reported as endometriosis by histological examination. The sciatica was resolved after surgery. CONCLUSIONS: Extrapelvic sciatic nerve compression by adjacent endometriosis is very infrequent. Muscle denervation and lack of a histological diagnosis led to surgical exploration of the compression area in order to release the nerve, resect the cause of compression and obtain a definitive diagnosis. The procedure improved all symptoms.