Enfermedad de Rosai-Dorfman intracraneal: un infrecuente diagnóstico diferencial del meningioma. Reporte de un caso ilustrativo

La Enfermedad de Rosai-Dorfman es un trastorno infrecuente y de etiología desconocida. La presentación intracraneal es aún más rara y suele imitar la apariencia de un meningioma en las imágenes del encéfalo. Se presenta el caso de un paciente varón de 38 años que ingresa por una tumoración intracraneal, extra-axial y supratentorial asociada a déficit neurológico leve; con diagnóstico presuntivo de meningioma de la convexidad. Después de la intervención quirúrgica, el diagnóstico histológico definitivo fue de Enfermedad de Rosai-Dorfman intracraneal. Se debe considerar la Enfermedad de Rosai-Dorfman intracraneal dentro del diagnóstico diferencial de una lesión intracraneal extra-axial sugestiva de un meningioma debido a la similitud en las neuroimágenes y la presentación clínica entre ambas patologías.

Rosai-Dorfman disease is an infrequent condition with no known etiology. The intracranial presentation is even rarer, and it resembles the appearance of a meningioma in image studies. We present the case of a 38-year-old male patient who was admitted because of an extra-axial supratentorial cranial tumor, associated to mild neurological deficit. The presumptive diagnosis was convexity meningioma. After surgery, the definitive histologic diagnosis was intracranial Rosai-Dorfman disease. This condition should be considered in the differential diagnosis of an extra-axial intracranial lesion suggesting meningioma, because of similar neuroimaging results and the similar clinical picture.

Application progress in synthetic and natural polymer materials for dural membrane repair / 国际生物医学工程杂志

The dura mater is a double-layer tough membrane tissue located between the surface of the brain and the inner surface of the skull that supports and protects the brain tissue. The phenomenon of dural defects caused by tumor resection, inflammation destruction, and craniotomies is becoming more common clinically. Therefore, the development of effective dural repair materials can not only reduce the leakage of cerebrospinal fluid and the occurrence of epilepsy complications but also promote the recovery of the dural defect to its normal physiological structure. With the continuous development of modern medicine, many biomaterials have been developed for dural defect repair. At present, the most promising and most researched biomaterials are synthetic polymer materials and natural polymer materials. Synthetic polymer materials have been extensively studied by domestic and foreign scholars due to their stable performance, low foreign body infection, and easy mass production advantages. Natural polymer materials are the most promising biomaterials because of their extensive sources, excellent biocompatibility, and biodegradability advantages. This article summarizes the research progress based on synthetic polymer materials and natural polymer materials in dural repair materials. In this review paper, the application progress of synthetic polymer materials and natural polymer materials in dural membrane repair was reviewed.

Presence of mast cells in the rat pericranium ­ a tissue very sensitive to pain / Presença de mastócitos no pericrânio do rato ­ tecido muito sensível à dor

Objective: To evaluate mast cell presence in the pericranium of Wistar rats. Methods: Five male rats of the Wistar strain were used. The animals were housed under a 12 h light cycle with ad libitum access to food and water and allowed 10 days of acclimatization before tissue sampling. The five rats were anesthetized by intraperitoneal injection of ketamine/xylazine, 10/20 mg/kg. Following aseptic preparation of the head skin, a midline longitudinal incision was made to expose the pericranium. Two samples of the pericranium were taken, one from the right and one from the left. These samples were fixed in 10% buffered formaldehyde for 24 h. After fixation, tissue samples were paraffin-embedded and sectioned at 4 µm. Then, slides were deparaffinized, stained with a concentration of 0.1% toluidine blue for 1 min, and washed with distilled water. Last, slides were photomicrographed under 400x magnification to identify mast cells. Results: Mast cells were identified in the dura mater and the five rats' pericranium. In the dura mater, mast cells were also found in these rats. We found both granulated (intact) and degranulated mast cells. Conclusion: We suggest that future preclinical studies investigating the involvement of dural mast cells and other meningeal cell populations should also include pericranium samples to explore this structure's relevance in migraine pain and other headache disorders.

Objetivo: Avaliar a presença de mastócitos no pericrânio de ratos Wistar. Métodos: Foram utilizados cinco ratos machos da linhagem Wistar. Os animais foram alojados sob um ciclo de luz de 12 horas com acesso ad libitum a comida e água e tiveram 10 dias de aclimatação antes da amostragem de tecido. Os cinco ratos foram anestesiados por injeção intraperitoneal de cetamina/xilazina, 10/20 mg/kg. Após preparação asséptica da pele da cabeça, foi feita uma incisão longitudinal na linha média para expor o pericrânio. Foram retiradas duas amostras do pericrânio, uma da direita e outra da esquerda. Essas amostras foram fixadas em formaldeído tamponado a 10% por 24 horas. Após a fixação, as amostras de tecido foram embebidas em parafina e seccionadas a 4 µm. Em seguida, as lâminas foram desparafinizadas, coradas com concentração de azul de toluidina 0,1% por 1 min e lavadas com água destilada. Por fim, as lâminas foram fotomicrografadas com aumento de 400x para identificação de mastócitos. Resultados: Foram identificados mastócitos na dura-máter e no pericrânio dos cinco ratos. Na dura-máter, mastócitos também foram encontrados nesses ratos. Encontramos mastócitos granulados (intactos) e desgranulados. Conclusão: Sugerimos que futuros estudos pré-clínicos que investiguem o envolvimento de mastócitos durais e outras populações de células meníngeas também incluam amostras de pericrânio para explorar a relevância desta estrutura na dor da enxaqueca e em outros distúrbios de cefaleia.

Storage and purification adaptations for the isolation of total RNA from the dura mater / Adaptações no armazenamento e purificação para o isolamento de RNA total da dura-máter

Abstract Background RNA extraction is a step that precedes several molecular techniques. The fibrous tissue, more specifically the dura mater, has several limitations in routine protocols, and lacks optimization protocols to overcome these problems. Objective To test stock reagents and purification kits, optimizing commercial kit protocols for RNA extraction from the dura mater. Methods Dura mater samples were obtained from eight Wistar rats and maintained in two different stabilizers. The samples were purified using four different protocols, and the RNA was evaluated for the yield and purity in NanoDrop 2000 (Thermo Scientific, Wilmington, DE, United States). Beta-actin gene was used for analyzing gene expression, since is one of the most used reference genes. Results The RNA preservation was similar in both stabilizers. The addition of an incubation step prior the purification protocols allowed better tissue digestion and RNA recovery. The RNA purified using the protocols membrane-based showed higher quality than liquid-liquid purification. This impact was observed in the 3-week evaluation using RT-qPCR. Conclusion Stabilizers are efficient for RNA preservation and membrane-based purification protocols are more suitable for RNA recovery from dura mater tissue, allowing the evaluation of gene expression in this type of tissue. Adaptations in the dura mater RNA extraction protocol differ from the pre-established protocols because it takes into account the peculiarity of fibrous tissue and low cellularity. In addition to providing a low-cost mechanism, based on techniques that are part of the laboratory routine, it is possible to improve the quality of the extracted material, ensuring greater efficiency in the use of subsequent techniques.

Resumo Antecedentes A extração de RNA é uma etapa que antecede várias técnicas moleculares. O tecido fibroso, mais especificamente a dura-máter, apresenta várias limitações nos protocolos de rotina e carece de protocolos de otimização para superar estes problemas. Objetivo Testar reagentes de estoque e kits de purificação, otimizando protocolos de kits comerciais para extração de RNA da dura-máter. Métodos Amostras de dura-máter foram obtidas de oito ratos Wistar e mantidas em dois estabilizadores diferentes. As amostras foram purificadas em quatro protocolos diferentes e o RNA foi avaliado quanto ao rendimento e pureza no NanoDrop 2000 (Thermo Scientific, Wilmington, DE, United States). O gene da beta-actina foi utilizado para analisar a expressão gênica, uma vez que é um dos genes de referência mais utilizados. Resultados A preservação do RNA foi semelhante em ambos os estabilizadores. A adição de uma etapa de incubação antes dos protocolos de purificação permitiu uma melhor digestão do tecido e recuperação de RNA. O RNA purificado pelos protocolos baseados em membrana apresentou qualidade superior ao da purificação líquido-líquido. Este impacto foi observado na avaliação de três semanas usando RT-qPCR. Conclusão Os estabilizadores são eficientes para preservação do RNA e os protocolos de purificação baseados em membrana são mais adequados para recuperação de RNA do tecido da dura-máter, permitindo a avaliação da expressão gênica neste tipo de tecido. As adaptações no protocolo de extração de RNA da dura-máter diferem dos protocolos preestabelecidos porque leva em consideração a peculiaridade do tecido fibroso e com baixa celularidade. Além de fornecer um mecanismo de baixo custo, baseado em técnicas que fazem parte da rotina laboratorial, é possível melhorar a qualidade do material extraído, garantindo maior eficácia no uso de técnicas subsequentes.

Deambulación precoz e incidencia de cefalea pospunción dural en paciente obstétrica propuesta para cesárea electiva / Early ambulation and incidence of postdural puncture headache in an obstetric patient proposed for elective cesarean section

Introducción: La cefalea pospunción dural es la complicación más habitual tras la anestesia neuroaxial, y es especialmente frecuente en obstetricia, un hallazgo común en el período posparto. Suele ser una complicación benigna y autolimitada, pero sin tratamiento puede conducir a otras complicaciones más graves. Objetivo: Describir la incidencia de cefalea pospunción dural en las pacientes obstétricas programadas para cesárea electiva con anestesia espinal y su relación con la deambulación precoz. Métodos: Se realizó un estudio observacional descriptivo en una serie de casos (50), todas las pacientes propuestas para cesárea electiva bajo el método anestésico espinal subaracnoideo con trocar calibre 25 en el período comprendido entre mayo a diciembre del 2018. Resultados: De un total de 50 pacientes estudiadas con edades entre 18 y 35 años de edad, al 96 por ciento se le realizó punción única de la duramadre, en todas se utilizó trócar 25, atraumático y ninguna presentó cefalea pospunción dural. Conclusiones: Se concluye que la incidencia de cefalea pospunción dural puede disminuir cuando se utilizan agujas espinales atraumáticas, de pequeño calibre; lo cual facilita también la deambulación temprana de la paciente(AU)

Introduction: Postdural puncture headache is the most common complication following neuraxial anesthesia, and is especially common in obstetrics, a common finding in the postpartum period. It is usually a benign and self-limited complication, but if not treated, it can lead to further serious complications. Objective: To describe the incidence of postdural puncture headache in obstetric patients scheduled for elective cesarean section with spinal anesthesia and its relationship with early ambulation. Methods: A descriptive observational study was carried out in a case series (50) of patients proposed for elective cesarean section under the subarachnoid spinal anesthesia method with 25-gauge trocar in the period from May to December 2018. Results: Out of a total of 50 patients aged 18-35 years who participated in the study, 96 percent underwent single dura mater puncture. In all cases, a 25-gauge trocar was used and none presented postdural puncture headache. Conclusions: The incidence of postdural puncture headache may be concluded to decrease when atraumatic spinal needles of small caliber are used, which also facilitates early ambulation of the patient(AU)

Diagnostic value of the fat deposition between the base of spinous process and dura mater for occult pars interarticularis defect / 中华骨科杂志

Objective:To observe the diagnostic value of the fat deposition between the base of spinous process and dura mater in the mid-sagittal T1WI image of lumbar spine MRI for occult pars interarticularis defect, and to discuss the its mechanism.Methods:From January 2015 to December 2019, 32 cases with low back and leg pain were confirmed by MR scanning that the fat deposition between the dura mater and the base of spinous process with or without fat deposition in the rest of the spinal canal, including 20 males and 12 females were included. The age was 28.5±6.2 years (range, 18-57 years). Spiral CT scanning and multiplanar reconstruction were used to judge the integrity of the isthmus, levels of defect, and unilateral or bilateral defect. The observation of the above imaging data were independently completed by two orthopaedic doctors.Results:In 32 patients with epidural fat deposition, there were 24 patients with occult isthmus and 8 patients with simple epidural lipomatosis, confirmed by spiral CT multiplanar reconstruction. In 24 cases of isthmus, there were 18 males and 6 females. The age was 27.3±5.3 years (range, 18-45 years). There were 2 cases between the base of L 4 spinous process and dura mater, and 22 cases between the base of L 5 spinous process and dura mater, without fat deposition in the rest of the spinal canal. All 24 cases were bilateral isthmus, and the anterior and lateral X-ray could not be diagnosed. All patients complained of different degrees of mechanical low back pain. 6 cases with disc herniation, and no case with intermittent claudication. In 8 patients with simple epidural lipomatosis, there were 2 males and 6 females. The age ranged from 32 to 55 years, with an average of 38.4±6.7 years. There were 4 cases between the base of L 3 spinous process and dura mater, 3 cases between the base of L 4 spinous process and dura mater, and 1 case between the base of L 5 spinous process and dura mater. All 8 patients had fat deposition between the lamina and dura mater in the upper and/or the same level, and the dura mater was compressed by the fat. 8 patients complained of different degrees of low back pain without tenderness. 2 cases with disc herniation, and one case with intermittent claudication. Conclusion:The fat deposition sign between the base of spinous process and dura mater has certain specificity for occult lumbar spondylolysis. As an effective supplement to the discontinuous bone signal of spondylolysis, it is helpful to the early diagnosis of spondylolysis.

Clinical outcomes following microsurgery and endovascular embolization in the management of spinal dural arteriovenous fistula: A meta-analysis study / 北京大学学报(医学版)

OBJECTIVE@#To compare the clinical effect of microsurgery and endovascular embolization in the treatment of spinal dural arteriovenous fistula (SDAVF) by meta-analysis.@*METHODS@#A systematic review was performed to retrieve all relevant literature about surgical treatment or endovascular embolization of SDAVF up to December 2019 through PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials Results, CNKI, Wanfang Data, and SinoMed. The Chinese and English key words included: "SDAVF", "spinal dural arteriovenous fistula", "spinal AVM", "spinal vascular malformation and treatment". The included studies were evaluated using the Newcastle-Ottawa scale. The early failure rate, long-term recurrence, neurological recovery, and complications were evaluated and the clinical effects of the two methods in the treatment of SDAVF were compared by using RevMan 5.3 software. And a further subgroup analysis of the therapeutic effect of endovascular embolization with different embolic agents was conducted.@*RESULTS@#A total of 46 studies involving 1 958 cases of SDAVF were included, in which 935 cases were treated by microsurgery and 1 023 cases were treated by endovascular embolization. The funnel plot demonstrated that there was no publication bias. The results of meta-analysis showed that the incidence of early surgical failure was lower than that of endovascular embolization (OR=0.20, 95%CI: 0.13-0.30, P < 0.05), and the long-term recurrence was also lower than that of endovascular embolization (OR=0.36, 95%CI: 0.22-0.58, P < 0.05). The improvement of neurological function in the surgical patients is significantly higher than that in the patients treated with endovascular embolization (OR=2.86, 95%CI: 1.36-5.99, P < 0.05). There was no significant difference in the occurrence of complications in these two groups (OR=1.52, 95%CI: 0.88-2.64, P=0.14). In the cases of endovascular embolization, the risk of treatment failure or recurrence was higher with Onyx glue than with n-butyl 2-cyanoacrylate (NBCA), and the difference was statistically significant (OR=4.70, 95%CI: 1.55-14.28, P < 0.05).@*CONCLUSION@#Although the treatment of dural arteriovenous fistulas by intravascular embolization has been widely used, the clinical effect of microsurgery is still better than that of endovascular embolization. Large scale and high-quality randomized controlled trials are required to validate the efficacy and safety of endovascular treatment in SDAVF patients.

Quantitative evaluation of the regenerated dura mater in a decompressive skull trepanation model in rats / Evaluación cuantitativa de la duramadre regenerada en un modelo de perforación cranial descompresiva en ratas

SUMMARY: Regeneration of the dura mater following duraplasty using a collagen film, a chitosan film, or a combination of both with gelatin, was studied in a craniotomy and penetrating brain injury model in rats. Collagen autofluorescence in the regenerated dura mater was evaluated using confocal microscopy with excitation at λem = 488 nm and λem = 543 nm. An increase in regeneration of the extracellular matrix of connective tissue and an increase in matrix fluorescence were detected at 6 weeks after duraplasty. The major contributors to dura mater regeneration were collagen films, chitosan plus gelatin-based films, and, to a much lesser extent, chitosan-based films. By using autofluorescence densitometry of extracellular matrix, the authors were able to quantify the degree of connective tissue regeneration in the dura mater following duraplasty.

RESUMEN: Se estudió la regeneración de la duramadre después de una duraplastía utilizando una lámina de colágeno, una lamina de quitosano o una combinación de ambas con gelatina en un modelo de craneotomía y lesión cerebral en ratas. La autofluorescencia del colágeno en la duramadre regenerada se evaluó mediante microscopía confocal con excitación a λem = 488 nm y λem = 543 nm. Se observó un aumento en la regeneración de la matriz extracelular del tejido conectivo y un aumento en la fluorescencia de la matriz a las 6 semanas después de la duraplastía. Se observe un efecto significativo en la regeneración de la duramadre con las láminas de colágeno, las láminas en base de quitosano más gelatina y, en un menor grado, las láminas a base de quitosano. Mediante el uso de densitometría de autofluorescencia de la matriz extracelular, los autores lograron cuantificar el grado de regenera- ción del tejido conectivo en la duramadre después de la duraplastía.

Individual variation of tentorial notch morphometry in a series of neurocritical patients / Variación individual de la morfometría de la hendidura tentorial en una serie de pacientes neurocríticos

Background: Cadaveric studies on humans have shown anatomical variabilities in the morphometric characteristics of the tentorial notch. These anatomical variations could influence the worsening of neurocritical patients. Objectives: 1) To investigate the morphometric characteristics of the tentorial notch in neurocritical patients using computed tomography (CT); 2) To investigate the correlation between tentorial notch measurements by CT and by magnetic resonance imaging (MRI); and 3) To analyze the individual variability of the tentorial notch anatomy seen in neurocritical patients. Methods: Prospective series of neurocritical patients was examined. An imaging protocol for measurements was designed for CT and MRI. The level of the agreement of the measurements from CT and MR images was established. According to the measurements found, patients were divided into different types of tentorial notch. Results: We studied 34 neurocritical patients by CT and MRI. Measurements of the tentorial notch via CT and MRI showed significant agreement: concordance correlation coefficient of 0.96 for notch length and 0.85 for maximum width of tentorial notch. Classification of tentorial notch measurements according to the criteria established by Adler and Milhorat, we found the following: 15 patients (58%) corresponded to a "short" subtype; 7 (21%) to "small"; 3 (9%) to "narrow"; 2 (6%) to "wide"; 2 (6%) to "large"; 1 (3%) to "long"; and 4 (12%) to "typical". Conclusions: The anatomical variability of the tentorial notch could be detected in vivo by means of CT scan and MRI. Good agreement between the measurements made using these two imaging methods was found.

Antecedentes: Estudios cadavéricos en humanos han mostrado variabilidad anatómica en las características morfométricas de la hendidura tentorial (HT). Estas variaciones anatómicas podrían influir en el neurodeterioro agudo de los pacientes neurocríticos. Objetivos: 1) Investigar las características morfométricas de la HT en pacientes neurocríticos mediante tomografía computarizada (TC); 2) Investigar la correlación de las mediciones de la HT realizadas por TC y resonancia magnética (RM); 3) Analizar la variabilidad individual de la anatomía de la HT observada en pacientes neurocríticos. Métodos: Se examinó una serie prospectiva de pacientes neurocríticos. Se diseñó un protocolo de imágenes para mediciones por TC y RM. Se estableció la concordancia de las mediciones realizadas mediante TC y RM. Según las mediciones encontradas, los pacientes se dividieron en diferentes tipos de HT. Resultados: Estudiamos 34 pacientes neurocríticos por TC y RM. Las mediciones de la HT por TC y RM mostraron una concordancia significativa: coeficiente de correlación de concordancia de 0,96 para la longitud de la HT y 0,85 para el ancho máximo de la HT. Clasificando las medidas de la HT de acuerdo con los criterios establecidos por Adler y Milhorat, encontramos: 15 pacientes (58%) correspondieron al subtipo "corto", 7 (21%) al "pequeño", 3 (9%) al "estrecho" ", 2 (6%) a "ancho ", 2 (6%) al "grande ", 1 (3%) al "largo" y 4 (12%) al "típico". Conclusiones: Se pudo detectar variabilidad anatómica de la HT in vivo, mediante TC y RM. Se encontró una buena concordancia en las medidas obtenidas con ambos métodos imagenológicos.

Effect of thrombin concentration on the prevention of postoperative cerebrospinal leakage by fibrin glue / 中国组织工程研究

BACKGROUND: Fibrin glue is commonly used to prevent postoperative cerebrospinal fluid leakage from dural injuries. However, fibrin glue with standard-concentration thrombin coagulates too fast, resulting in poor adhesion of dural mater. Effect of low-concentration thrombin fibrin glue on sealing dural injuries to prevent cerebrospinal fluid leakage is unclear. OBJECTIVE: To compare the effect of low-concentration thrombin and standard-concentration thrombin on the prevention of cerebrospinal fluid leakage from dural injuries by fibrin glue. METHODS: Forty patients including 25 males and 15 females with dural injuries admitted at Fifth People’s Hospital of Chengdu from May 2017 to December 2019 were enrolled. Patients were randomly divided into two groups, 20 patients in each group. In low-concentration thrombin group, dural injuries were sealed with fibrin glue prepared with low-concentration thrombin solution (100 IU/mL). In standard-concentration thrombin group, dural injuries were sealed with fibrin glue prepared with standard-concentration thrombin solution (500 IU/mL). All patients were followed up for 2 months. The incidence of cerebrospinal fluid leakage, cumulative drainage flow, drainage duration and incision complications were compared between the two groups. The study was approved by Ethics Committee of Fifth People’s Hospital of Chengdu. RESULTS AND CONCLUSION: (1) The incidence of cerebrospinal leakage, accumulative volume and duration of drainage in the low-concentration thrombin group were lower than those of standard-concentration thrombin group (P 0.05). (3) These results indicate that fibrin glue prepared with low-concentration thrombin solution decreases the rate of cerebrospinal leakage, reduces the drainage volume and shortens the duration of drainage, which is demonstrated to be an effective strategy for sealing dural injuries.

Diagnosis and surgical treatment of symptomatic lumbar spinal epidural liposis / 中国骨伤

OBJECTIVE@#To explore diagnosis and surgical treatment of symptomatic lumbar spinal epidural lipoplasia.@*METHODS@#A retrospective analysis of 19 patients with symptomatic lumbar spinal epidural hyperplasia treated with hemilaminectomy and interbody fusion and internal fixation from February 2012 to November 2018 were performed, including 7 males and 12 females, aged from 48 to 72 years old with an average of (57.6±1.2) years old;the course of disease ranged from 6 to 60 months with an average of (18.6±5.1) months;plane requiring decompression:L@*RESULTS@#All patients were followed up from 12 to 37 months with an average of (16.3±3.8) months. Ninteen patients were successfully completed operation, and all adipose tissues in the compressed segment of the spinal canal were removed. Operation time was from 125 to 260 min with an average of (186± 15) min, and blood bleeding was from 150 to 500 ml with an average of (280±46) ml. Two patients occurred partial incision fat liquefaction and exudate did not heal, the incision was opened to remove effusion, the dressing was changed and anti-inflammatory treatments were performed. No complications such as cauda equina injury, cerebrospinal fluid leakage, and broken nails occurred. Preopertaive VAS of back pain and leg pain were 5.3±0.7 and 6.8±0.8, respectively, while 2.1±0.4 and 2.3±0.5 respectively at 6 months after opertaion, there were statisticalsignificant difference between 6 months after operation and before operation (@*CONCLUSION@#Patients with symptomatic lumbar spinal epidural lipoplasia undergo hemilaminectomy and internal fixation of compression segment could relieve compression of dura mater and cauda equina, and achieve good clinical results.

Application of Sequential Changes of Dural Thickness and Biomechanical Parameters in Postmortem Interval Estimation / 法医学杂志

Objective To study the relations of the dural thickness and the biomechanical parameters with postmortem interval （PMI） of human cadavers, and to explore the feasibility of the two indexes used for PMI estimation. Methods Dural samples were collected at different postmortem intervals of 6 h, 12 h, 18 h, 24 h, 30 h, 36 h, 48 h, 60 h, 72 h, 84 h and 96 h, then fabricated into 4.0 cm×1.0 cm A and B test specimens. The thickness of the A test specimen was measured, and the biomechanical parameters, such as ultimate load, maximum force deformation, tensile strength, elastic modulus and fracture force, were measured. The regression equations of thickness, biomechanical parameters and PMI were fitted respectively, and the difference between the predicted value and actual measured value of PMI was verified by the verification group. The B test specimen was fixed with 10% neutral formaldehyde solution, then tissue sections were prepared to observe its morphological changes. Results From 6 h to 96 h after death, the dural thickness decreased gradually, the collagen fibers gradually changed from clear arrangement to mutual fusion, and the number of nuclei decreased gradually. The dural thickness, ultimate load, tensile strength, elastic modulus and fracture force decreased sequentially, among which the dural thickness, ultimate load, elastic modulus and fracture force had a correlation with PMI （P<0.05）. In the return test, the difference between the predicted value and actual measured value of PMI in the verification group had no statistical significance （P>0.05）. Conclusion The dural thickness, ultimate load, elastic modulus and fracture force change sequentially from 6 h to 96 h after death. The regression equation established by the relationship between the changes and PMI can be used for PMI estimation.

Clinical analysis of 5 cases of dural arteriovenous fistulas complained of pulsatile tinnitus / 中华耳鼻咽喉头颈外科杂志

Objective@#The clinical characteristics of dural arteriovenous fistula with pulsatile tinnitus were analyzed to deepen the understanding of the disease.@*Methods@#The clinical data of five patients complained of pulsatile tinnitus and diagnosed dural arteriovenous fistula in Henan People's Hospital from May 2013 to June 2018 were retrospectively analyzed, including 3 males and 2 females, aged 27-65 years.@*Results@#The main clinical symptoms of the five patients were continuous pulsatile tinnitus, accompanied/not accompanied by headache, memory decline, etc., with a course of three months to 20 years. They were diagnosed as dural arteriovenous fistula by digital subtraction angiography, and three cases of tinnitus disappeared and two cases of tinnitus were relieved after embolization.@*Conclusions@#The dural arteriovenous fistula is a rare and complicated disease. When the patient complain of the pulsatile tinnitus, the related etiology should be considered and managed properly.

Experimental study of the neurotoxic effects of photodynamic therapy on the spinal cord / Estudo experimental dos efeitos neurotóxicos da terapia fotodinâmica na medula espinhal / Estudio experimental de los efectos neurotóxicos de la terapia fotodinámica en la médula espinal

ABSTRACT Objective To evaluate the effects of photodynamic therapy (PDT) on the dura mater using the photosensitizers aluminum chloride phthalocyanine and methylene blue in in vivo assays. Methods Fifty-six male Wistar rats were divided into two groups; one submitted to PDT and the other submitted to the photosensitizers without their photoactivation (control). The photosensitizers were applied to the dura mater after laminectomy at the T10 level. The methods used for assessment were the Basso, Beattie and Bresnahan (BBB) functional evaluation scale and study of the dura mater by light microscopy. Results No changes in motor activity were observed in the animals submitted to PDT compared to control. Histological and pathological evaluation did not show any differences between the group exposed to activated photosensitizers and the control group with regard to the inflammatory process and tissue necrosis. Conclusion The joint use of PDT with the photosensitizing pharmaceuticals aluminum chloride phthalocyanine and methylene blue did not induce any clinical neurotoxic effects or histological changes in the dura mater of the animals studied. Level de evidence V; Expert Opnion.

RESUMO Objetivo Avaliar os efeitos da terapia fotodinâmica (PDT) na dura-máter usando os fotossensibilizadores cloreto de alumínio ftalocianina e azul de metileno em ensaios in vivo. Métodos Cinquenta e seis ratos Wistar machos divididos em dois grupos; um submetido à PDT e o outro submetido aos fotossensibilizadores sem a fotoativação (controle). Os fotossensibilizadores foram aplicados sobre a dura-máter depois de laminectomia no nível T10. Os métodos de avaliação usados foram a escala de avaliação funcional de Basso, Beattie e Bresnahan (BBB) e o estudo da dura-máter por microscopia óptica. Resultados Não foram observadas alterações da atividade motora dos animais submetidos à PDT com relação ao grupo controle. A avaliação histológica e histopatológica não mostrou diferenças entre o grupo exposto aos fotossensibilizadores ativados e o grupo controle, com relação ao processo inflamatório e à necrose tecidual. Conclusões O uso conjunto de PDT e os fármacos fotossensibilizantes cloreto de alumínio ftalocianina e azul de metileno não induziu efeitos neurotóxicos clínicos e/ou alterações histológicas sobre a dura-máter dos animais estudados. Nível de evidência V; Opinião de Especialista.

RESUMEN Objetivo Evaluar los efectos de la terapia fotodinámica (PDT) en la duramadre utilizando los fotosensibilizadores de ftalocianina de aluminio clorada y azul de metileno en ensayos in vivo. Métodos Cincuenta y seis ratas Wistar machos se dividieron en 2 grupos; uno fue sometido a PDT y el otro sometido a fotosensibilizadores sin fotoactivación (control). Los fotosensibilizadores se aplicaron a la duramadre después de la laminectomía en el nivel T10. Los métodos de evaluación utilizados fueron la escala de evaluación funcional de Basso, Beattie y Bresnahan (BBB) y el estudio de la duramadre mediante microscopía óptica. Resultados No hubo cambios en la actividad motora de los animales sometidos a PDT en relación con el grupo de control. La evaluación histológica e histopatológica no mostró diferencias entre el grupo expuesto a fotosensibilizadores activados y el grupo de control con respecto al proceso inflamatorio y la necrosis tisular. Conclusiones El uso conjunto de PDT con las sustancias fotosensibilizadores ftalocianina de aluminio clorada y azul de metileno no indujo efectos neurotóxicos clínicos o cambios histológicos en la duramadre de los animales estudiados. Nivel de evidencia V; Opinión del Especialista.

The effects of mobile phone exposure on mast cells in rat dura mater / Efectos de la exposición del teléfono móvil en los mastocitos de la duramadre de ratas

Mobile phone use has increased rapidly. The central nervous system has been shown to be adversely affected by its electromagnetic field (EMF) resulting in headache and sleep disturbances. How the cells make up the CNS and are affected by EMF is unclear. However, because of their central role in inflammation through diverse stimuli including radiation, this study aimed to investigate the effects of electromagnetic fields induced by mobile phones on mast cells in rat dura mater. A total of 18 adult, female, SpragueDawley rats were divided into two groups. The choice of female rats for his study was based on recent surveys demonstrating that mobile phone use is more frequent and prolonged among females. The study group was exposed to 900 MHz electromagnetic field (1 h/day for 45 days). In the end of the study, duramater tissue was extracted and stained using Toluidine blue. Mast cells were counted and results were analysed using Student t test. Mean mast cell number was 202.33±9.82 and 456.78±35.01 in the control and study groups, respectively (p<0.05). Analysis of serum electrolyte and immunoglobulin E levels showed no statistically significant difference between the two groups (p>0.05). The study showed that mobile phone exposure increased mast cell number and degranulation in rat dura mater. Further studies are required to evaluate the clinical implications of these findings.

El uso del teléfono móvil ha aumentado rápidamente. Se ha demostrado que el sistema nervioso central (SNC) se ve afectado de manera adversa debido al campo electromagnético (CEM) que produce dolor de cabeza y trastornos del sueño. No está claro cómo se ve afectada la composición celular del SNC por el CEM. Sin embargo, debido a su función principal en la inflamación a través de diversos estímulos que incluyen la radiación, este estudio tuvo como objetivo investigar los efectos de los campos electromagnéticos inducidos por los teléfonos móviles en los mastocitos de la duramadre de ratas. Un total de 18 ratas Sprague-Dawley adultas, hembras, se dividieron en dos grupos. Se usaron ratas hembras para este estudio en base a investigaciones recientes que han demostrado que el uso de teléfonos móviles es más frecuente y prolongado en las mujeres. Los grupos de estudio fueron expuestos a un campo electromagnético de 900 MHz (1 h / día durante 45 días). Al término del estudio, fue extirpado el tejido de la duramadre y teñido con azul de toluidina. Se contaron los mastocitos y se analizaron los resultados utilizando la prueba t de Student. La cantidad media de células cebadas fue de 202,33 ± 9.82 y 456,78 ± 35,01 en los grupos control y estudio, respectivamente (p <0,05). El análisis del electrolito sérico y los niveles de inmunoglobulina E no mostraron diferencias estadísticamente significativas entre los dos grupos (p> 0,05). El estudio mostró que la exposición a teléfonos móviles aumentó el número de mastocitos y la desgranulación en la duramadre de las ratas. Se requieren estudios adicionales para evaluar las implicaciones clínicas de estos hallazgos.

Comparison of Biomechanical Properties of Dura Mater Substitutes and Cranial Human Dura Mater : An In Vitro Study

OBJECTIVE: The aim of this study was to investigate the biomechanical differences between human dura mater and dura mater substitutes to optimize biomimetic materials.METHODS: Four groups were investigated. Group I used cranial dura mater (n=10), group II used Gore-Tex® Expanded Cardiovascular Patch (W.L. Gore & Associates Inc., Flagstaff, AZ, USA) (n=6), group III used Durepair® (Medtronic Inc., Goleta, CA, USA) (n=6), and group IV used Tutopatch® (Tutogen Medical GmbH, Neunkirchen am Brand, Germany) (n=6). We used an axial compression machine to measure maximum tensile strength.RESULTS: The mean tensile strengths were 7.01±0.77 MPa for group I, 22.03±0.60 MPa for group II, 19.59±0.65 MPa for group III, and 3.51±0.63 MPa for group IV. The materials in groups II and III were stronger than those in group I. However, the materials in group IV were weaker than those in group I.CONCLUSION: An important dura mater graft property is biomechanical similarity to cranial human dura mater. This biomechanical study contributed to the future development of artificial dura mater substitutes with biomechanical properties similar to those of human dura mater.

Biomechanical Properties of the Cranial Dura Mater with Puncture Defects: An In Vitro Study

OBJECTIVE: The primary aim of this investigation was to explore the nature of dura mater biomechanics following the introduction of puncture defect(s).METHODS: Twenty-eight dura mater specimens were collected during autopsy from the department of forensic medicine of the authors' institution. Specimens were divided randomly into one of four groups : group I (cranial dura mater; n=7), group II (cranial dura mater with one puncture defect; n=7); group III (cranial dura mater with two puncture defects; n=7), and group IV (cranial dura mater with three puncture defects; n=7).RESULTS: The mean±standard deviation tensile strengths of the dura mater were 8.35±3.16, 8.22±3.32, 7.13±1.77, and 6.94±1.93 MPa for groups I, II, III, and IV, respectively. There was no statistical difference between all groups. A single, two or more punctures of the dura mater using a 20-gauge Quincke needle did not affect cranial dura tensile strength.CONCLUSION: This biomechanical study may contribute to the future development of artificial dura mater substitutes and medical needles that have a lower negative impact on the biomechanical properties of dura mater.

Imaging and pathogenic characteristics of thoracic ossification of the ligamentum flavum complicated with dural ossification / 中华骨科杂志

Objective To investigate the imaging characteristics and pathogenic manifestations of thoracic ossification of the ligamentum flavum complicated with dural ossification.Methods CT and MRI imaging data of 62 segments from 29 patients with thoracic ossification of the ligamentum flavum (TOLF) treated with "en bloc resection of lamina and ossified mass" were retrospectively analyzed.There were 19 males and 10 females,aged 54.9±10.25 years (36-77 years),16 segments in 11 cases with dural ossification (DO) and 46 segments in 18 cases without DO.The ossified mass shape,the relationship between ossified mas and dura mater on cross section of CT bone window and MRI T2WI,and the ossified mass occupational rate (OR) of the spinal canal were investigated.Pathologic features of TOLF-DO from 2 patients were analyzed by H&E staining.Results The shape of ossified mass was as followed,in 16 segments with DO,7 segments (43.8％) by CT and 2 segments (12.5％) by MRI showing ossification layer on the dural sac side of ligamentum flavum;1 segment (6.3％) by CT and 2 segments (12.5％) by MRI showing typical Tram track sign.The relationship between ossified mass and dura mater was that 7 segments (43.8％) by CT and 7 segments (43.8％) by MRI with "C" sign and 7 segments (43.8％) by CT and 8 segments (50.0％) by MRI with "V" sign.The ossified mass OR was 60.5％± 13.0％ in the group with DO and 42.2％± 12.3％ in the group without DO.There was a significant difference between the two groups (t=5.192,P＜0.001).Among the 16 segments with DO,the ossified mass OR of 7 segments with "C" sign was 68.8％± 12.8％ and that of the other 9 segments without "C" sign was 54.39％±9.9％.There was significant difference between the two groups (t=2.45,P=-0.028).Histological examination showed that there were two pathological phenomena in the dura tissue adjacent to ossified mass.The one,there were fibrocartilage,cartilage and osteogenesis in the dura mater.The other,the unossified dura mater fused with the ossified mass but with clear histological demarcation,while the dura mater on the ventral side of the ossified ligamentum flavum atrophies or disappeared.Conclusion The occurrence of dural sac ossification is associated with the ossification of ligamentum flavum beginning at the side of the dural sac and the persistent thickening of the ossified mass.The pathological manifestations of DO are ossification of dural tissue or fusion of dural with ligamentum flavum ossification.

Comparison of Biomechanical Properties of Dura Mater Substitutes and Cranial Human Dura Mater : An In Vitro Study

OBJECTIVE: The aim of this study was to investigate the biomechanical differences between human dura mater and dura mater substitutes to optimize biomimetic materials. METHODS: Four groups were investigated. Group I used cranial dura mater (n=10), group II used Gore-Tex® Expanded Cardiovascular Patch (W.L. Gore & Associates Inc., Flagstaff, AZ, USA) (n=6), group III used Durepair® (Medtronic Inc., Goleta, CA, USA) (n=6), and group IV used Tutopatch® (Tutogen Medical GmbH, Neunkirchen am Brand, Germany) (n=6). We used an axial compression machine to measure maximum tensile strength. RESULTS: The mean tensile strengths were 7.01±0.77 MPa for group I, 22.03±0.60 MPa for group II, 19.59±0.65 MPa for group III, and 3.51±0.63 MPa for group IV. The materials in groups II and III were stronger than those in group I. However, the materials in group IV were weaker than those in group I. CONCLUSION: An important dura mater graft property is biomechanical similarity to cranial human dura mater. This biomechanical study contributed to the future development of artificial dura mater substitutes with biomechanical properties similar to those of human dura mater.

Biomechanical Properties of the Cranial Dura Mater with Puncture Defects: An In Vitro Study

OBJECTIVE: The primary aim of this investigation was to explore the nature of dura mater biomechanics following the introduction of puncture defect(s). METHODS: Twenty-eight dura mater specimens were collected during autopsy from the department of forensic medicine of the authors' institution. Specimens were divided randomly into one of four groups : group I (cranial dura mater; n=7), group II (cranial dura mater with one puncture defect; n=7); group III (cranial dura mater with two puncture defects; n=7), and group IV (cranial dura mater with three puncture defects; n=7). RESULTS: The mean±standard deviation tensile strengths of the dura mater were 8.35±3.16, 8.22±3.32, 7.13±1.77, and 6.94±1.93 MPa for groups I, II, III, and IV, respectively. There was no statistical difference between all groups. A single, two or more punctures of the dura mater using a 20-gauge Quincke needle did not affect cranial dura tensile strength. CONCLUSION: This biomechanical study may contribute to the future development of artificial dura mater substitutes and medical needles that have a lower negative impact on the biomechanical properties of dura mater.