A neglected normal anatomical structure in mammal: a study in bats and tree shrews / Una estructura anatómica normal desatendida en mamíferos: un estudio en murciélagos y musarañas arborícolas

SUMMARY: The myodural bridge is a dense connective tissue connecting muscles and ligaments to the spinal dura mater in the atlanto-occipital interspace. Some researchers believe that the myodural bridge may play a vital physiological role. It is possible, for instance, that the prevention of spinal dura mater infoldings might be involved in regulated cerebrospinal fluid circulation. For instance, it is possible to prevent spinal dura mater infoldings, regulating cerebrospinal circulation. Bats are nocturnal and the only mammals that can perform a genuine and sustained flight, whereas tree shrews are arboreal mammals that often climb to a high altitude of about 10,000 feet. Both animals have lifestyles that are different from other previously studied mammals. The study of these two animals will shed further light on the existence of the myodural bridge in mammals. Gross anatomical dissection was used to observe the connections between the deep muscles of the neck and the dura mater at the level of the atlanto-occipital interspace. The existing structures were analyzed using conventional and special histological staining techniques. The suboccipital regions in bats and tree shrews contained the rectus capitis dorsal major (RCDma), rectus capitis dorsal minor (RCDmi), oblique capitis anterior (OCA), and oblique capitis posterior (OCP). Dense connective tissue connects the RCDmi to the posterior atlanto-occipital membrane (PAOM) and the latter to the spinal dura mater. The myodural bridge in these mammals shares a similar structure to the myodural bridge in humans. Histological analyses confirmed that the connective fibers of the myodural bridge were primarily type I collagen fibers. In this study, it is supplemented by the existence of the myodural bridge in mammals. This further demonstrates that myodural bridge widely exists in the normal anatomy of mammals. This provides morphological support for a comparative anatomical study of the physiological function of the myodural bridge.

El puente miodural es un tejido conjuntivo denso que conecta los músculos y los ligamentos a la duramadre espinal en el espacio atlanto-occipital. Algunos investigadores creen que el puente miodural puede desempeñar un papel fisiológico vital. Es posible, por ejemplo, que la prevención de los pliegues de la duramadre espinal pueda estar involucrada en la circulación regulada del líquido cefalorraquídeo. En esta instancia, es posible prevenir los pliegues de la duramadre espinal, regulando la circulación cerebro espinal. Los murciélagos son animales nocturnos y los únicos mamíferos que pueden realizar un vuelo real y sostenido, mientras que las musarañas arborícolas son mamíferos arbóreos que a menudo ascienden a una gran altura de unos 10 000 pies. Ambos animales tienen estilos de vida diferentes a los de otros mamíferos previamente estudiados. El estudio de estos dos animales ofrecerá más información sobre la existencia del puente miodural en los mamíferos. Se realizó una disección anatómica macroscópica para observar las conexiones entre los músculos profundos del cuello y la duramadre a nivel del espacio atlanto-occipital. Las estructuras existentes se analizaron mediante técnicas de tinción histológica convencionales y especiales. Las regiones suboccipitales en murciélagos y musarañas arbóreas presentaban el músculo recto dorsal mayor de la cabeza (RCDma), el recto dorsal menor de la cabeza (RCDmi), el oblicuo anterior de la cabeza (OCA) y el oblicuo posterior de la cabeza (OCP). El tejido conjuntivo denso conecta el RCDmi con la membrana atlanto- occipital posterior (PAOM) y esta última con la duramadre espinal. El puente miodural en estos mamíferos comparte una estructura similar al puente miodural en humanos. Los análisis histológicos confirmaron que las fibras conectivas del puente miodural son principalmente fibras de colágeno tipo I. Esto demuestra además que el puente miodural existe ampliamente en la anatomía normal de los mamíferos. Esta investigación proporciona apoyo morfológico para un estudio anatómico comparativo de la función fisiológica del puente miodural.

Dissecação anatômica como estratégia para o estudo do sistema neural em fetos humanos / Anatomic dissection as a strategy for the study of the neural system in fetuses / Disección anatómica como estrategia para el estudio del sistema neural en fetos

Esse trabalho busca relatar o processo de confecção de peças anatômicas para o ensino da anatomia humana a partir de material cadavérico fetal. Os discentes do curso de medicina da Universidade Federal do Paraná (UFPR) ­ Campus Toledo participaram do programa de voluntariado acadêmico e deram atenção especial aos aspectos técnicos do processo de dissecação, bem como a experiência subjetiva desse procedimento como ferramenta de aprendizado ativo. O procedimento foi realizado na sala de preparação de cadáver da UFPR ­ Campus Toledo, utilizando instrumental de dissecação e cadáveres humanos fetais com 20, 17 e 14 semanas de idade gestacional, direcionado de modo a expor as partes constituintes do sistema neural. Foram confeccionadas peças de cérebro, cerebelo, tronco encefálico, medula espinal, nervos espinais e suas estruturas associadas. Os voluntários envolvidos foram capazes de produzir material de estudo de qualidade através da dissecação e fortalecer seu conhecimento em anatomia humana e aptidão manual. Também foi dada atenção à importância e às limitações do processo de dissecação como estratégia de aprendizado em cursos da área de saúde. pôde ser observado que a dissecação pode fazer parte de uma formação completa e bem estruturada dos discentes, que por sua vez irão integrar a sociedade e a academia. Além disso, a exposição da topografia neural fetal pode servir de referencial para posteriores estudos que venham a utilizar essas informações.

This work aims to report the confection process of anatomic pieces for teaching human anatomy from fetal cadaveric material. The students of the medicine course of Universidade Federal do Paraná (UFPR) ­ Campus Toledo, took part in the academic volunteer program and paid special attention to the technical aspects of the dissection process, as well as the subjective experience of this procedure as an active learning tool. The procedure was performed at the cadaver preparation room of the UFPR ­ Campus Toledo, using dissection tools and human fetal corpses of 20, 17 and 14 weeks of gestational ages, directed so as to expose the constituent parts of the neural system. Pieces of the brain, cerebellum, brainstem, spinal cord, spinal nerves, and its associated structures were made. The involved voluntaries were able to produce quality study material through dissection, and strengthen their knowledge in human anatomy and manual skill. Attention was also given to the importance and limitations of the dissection process as a learning strategy in health courses. it was observed that dissection can be part of a complete and well-structured training of students, who in turn will integrate society and academia. In addition, the exposure of fetal neural topography can serve as a reference for further studies that use this information

Este trabajo tiene como objetivo relatar el proceso de confección de piezas anatómicas para la enseñanza de la anatomía humana a partir de material cadavérico fetal. Los alumnos del curso de medicina de la Universidade Federal do Paraná (UFPR) - Campus Toledo, participaron del programa de voluntariado académico y prestaron especial atención a los aspectos técnicos del proceso de disección, así como a la vivencia subjetiva de este procedimiento como herramienta de aprendizaje activo. El procedimiento fue realizado en la sala de preparación de cadáveres de la UFPR - Campus Toledo, utilizando herramientas de disección y cadáveres de fetos humanos de 20, 17 y 14 semanas de edad gestacional, dirigidos de forma a exponer las partes constitutivas del sistema neural. Se realizaron piezas del cerebro, cerebelo, tronco encefálico, médula espinal, nervios espinales y sus estructuras asociadas. Los voluntarios participantes pudieron elaborar material de estudio de calidad mediante la disección y reforzar sus conocimientos de anatomía humana y habilidad manual. También se prestó atención a la importancia y las limitaciones del proceso de disección como estrategia de aprendizaje en los cursos de salud. Se observó que la disección puede formar parte de una formación completa y bien estructurada de los estudiantes, que a su vez integrarán la sociedad y el mundo académico. Además, la exposición de la topografía neural fetal puede servir de referencia para estudios posteriores que utilicen esta información.

Identification of the myodural bridge in a venomous snake, the gloydius shedaoensis: what is the functional significance? / Identificación del puente miodural en una serpiente venenosa, gloydius shedaoensis: ¿cuál es el significado funcional?

SUMMARY: Myodural bridges (MDB) are anatomical connections between the suboccipital muscles and the cervical dura mater which pass through both the atlanto-occipital and the atlanto-axial interspaces in mammals. In our previous studies, we found that the MDB exists in seven terrestrial mammal species, two marine mammal species, two reptilian species, and one bird species. A recent study suggested that given the "ubiquity" of myodural bridges in terrestrial vertebrates, the MDB may also exist in snakes. Specifically, we focused on the Gloydius shedaoensis, a species of Agkistrodon (pit viper snake) that is only found on Shedao Island, which is in the southeastern sea of Dalian City in China. Six head and neck cadaveric specimens of Gloydius shedaoensis were examined. Three specimens were used for anatomical dissection and the remaining three cadaveric specimens were utilized for histological analysis. The present study confirmed the existence of the MDB in the Gloydius shedaoensis. The snake's spinalis muscles originated from the posterior edge of the supraoccipital bones and the dorsal facet of the exocciput, and then extended on both sides of the spinous processes of the spine, merging with the semispinalis muscles. On the ventral aspect of this muscular complex, it gave off fibers of the MDB. These MDB fibers twisted around the posterior margin of the exocciput and then passed through the atlanto-occipital interspace, finally terminating on the dura mater. We observed that the MDB also existed in all of the snakes' intervertebral joints. These same histological findings were also observed in the Gloydius brevicaudus, which was used as a control specimen for the Gloydius shedaoensis. In snakes the spinal canal is longer than that observed in most other animals. Considering the unique locomotive style of snakes, our findings contribute to support the hypothesis that the MDB could modulate cerebrospinal fluid (CSF) pulsations.

RESUMEN: Los puentes miodurales (MDB) son conexiones anatómicas entre los músculos suboccipitales y la duramadre cervical que pasan a través de los espacios intermedios atlanto-occipital y atlanto-axial en los mamíferos. En nuestros estudios anteriores, encontramos que el MDB existe en siete especies de mamíferos terrestres, dos especies de mamíferos marinos, dos especies de reptiles y una especie de ave. Un estudio reciente sugirió que dada la "ubicuidad" de los puentes miodurales en los vertebrados terrestres, el MDB también puede existir en las serpientes. Específicamente, nos enfocamos en Gloydius shedaoensis, una especie de Agkistrodon (serpiente víbora) que solo se encuentra en la isla Shedao, en el mar sureste de la ciudad de Dalian en China. Se examinaron seis especímenes cadavéricos de cabeza y cuello de Gloydius shedaoensis. Se utilizaron tres especímenes para la disección anatómica y los tres especímenes cadavéricos restantes se utilizaron para el análisis histológico. El presente estudio confirmó la existencia del MDB en Gloydius shedaoensis. Los músculos espinosos de la serpiente se originaron en el margen posterior de los huesos supraoccipital y la cara dorsal del exoccipucio, y luego se extendieron a ambos lados de los procesos espinosas de la columna vertebral, fusionándose con los músculos semiespinosos. En la cara ventral de este complejo muscular se desprendían fibras del MDB. Estas fibras MDB se ubican alrededor del margen posterior del exoccipucio y luego atraviesan el interespacio atlanto-occipital, terminando finalmente en la duramadre. Observamos que el MDB también existía en todas las articulaciones intervertebrales de las serpientes. Estos mismos hallazgos histológicos también se observaron en Gloydius brevicaudus, que se utilizó como muestra de control para Gloydius shedaoensis. En las serpientes, el canal espinal es más largo que el observado en la mayoría de los otros animales. Teniendo en cuenta el estilo único locomotor de las serpientes, nuestros hallazgos contribuyen a respaldar la hipótesis de que el MDB podría modular las pulsaciones del líquido cerebroespinal.

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.

Intra- and extradural anterior clinoidectomy: anatomy review and surgical technique step by step.

PURPOSE: The complex relations of the paraclinoid area make the surgical management of the pathology of this region a challenge. The anterior clinoid process (ACP) is an anatomical landmark that hinders the visualization and manipulation of the surrounding neurovascular structures, hence in certain surgical interventions might be necessary to remove it. We reviewed the anatomical relationships that involve the paraclinoid area and detailed the step-by-step techniques of intra and extradural clinoidectomy in cadaveric specimens. MATERIALS AND METHODS: A literature review was done describing the most relevant anatomic relationships regarding the anterior clinoid process. Extradural and intradural clinoidectomy techniques were performed in six dry bone heads and in ten previously injected cadaverous specimens with colored latex (Sanan et al. in Neurosurgery 45:1267-1274, 1999) and each step of the procedure was recorded using photographic material. Finally, an analysis of the anatomical exposure achieved in each of the techniques used was performed. RESULTS: The main advantage of the intradural clinoidectomy technique is the direct visualization of the neurovascular structures adjacent to the ACP when drilling, at the same time, opening the Sylvian fissure will allow the direct visualization of the ACP variants. The main advantage offered by the extradural technique is that the dura protects adjacent eloquent structures while drilling. Among the disadvantages, it is noted that the same dura that would protect the underlying structures also prevents the direct visualization of these neurovascular structures adjacent to the ACP. CONCLUSION: We reviewed the anatomy of the paraclinoid area and made a step-by-step description of the technique of the anterior clinoidectomy in its intra- and extradural variants in cadaveric preparations for a better understanding.

Anatomy of the dura mater venous sinus of Alouatta belzebul.

The anatomy of the dura mater's venous sinuses is important in the veterinary clinical and surgical area, for cranial procedures and interventions of wild animals, in addition to assisting in the management of neurological diseases, which can prevent serious complications. The macroscopic anatomy of the venous sinuses of the dura mater of Alouatta belzebul was studied. Five adult specimens, males and females, were dissected and fixed in 10% formaldehyde solution. In the dura mater of the Alouatta belzebul, nine venous sinuses were observed, being them dorsal sagittal sinus, ventral sagittal sinus, transverse sinus, straight sinus, sigmoid sinus, temporal sinus, parietal sinus, basilar sinus and cavernous sinus, with morphological similarities in origin, path and destination of blood flow to the internal jugular vein, assisting in the venous drainage function of the brain in this species. These data are similar to those found in other species of non-human and human primates such as Saimiri sciureus, Sapajus libidinosus and Homo sapiens. Of the venous sinuses observed, the cavernous sinus was of considerable clinical and surgical importance in Alouatta belzebul due to its topographic arrangement next to the internal carotid artery and pituitary gland, data that corroborate Sapajus libidinosus, Macaca fascicularis, Macaca mulatta, Papio ursinus, Cercopithecus pygerithrus and Galago senegalensis. In this context, the knowledge of the macroscopic anatomy of the venous sinuses of the dura mater may contribute to the role of veterinarians in less invasive surgical procedures in non-human primates such as Alouatta belzebul and other mammals.

Existence of myodural bridge in the trachemys scripta elegans: indication of its important physiological function / Existencia del puente miodural en trachemys scripta elegans: indicación de su importante función fisiológica

The myodural bridge (MDB) is confirmed that connecting the most of suboccipital muscles to the cervical dura mater through the posterior intervertebral spaces and widely exists in mammals and birds. In order to reveal whether the MDB is universally existing in amniota of vertebrates, we explored the existence and the morphological features of the MDB in the Trachemys scripta elegans. Twenty fresh red-eared slider specimens were observed by the gross anatomy dissection and histological analysis. In the results, three kind of muscles in the postoccipital region of the red-eared slider were found. The rectus capitis dorsum minor muscle originated from the posterior margin of the occiput (C0) and terminated at the spinous process of the atlas (C1). The transversospinales muscle was attached to the vertebral arch and the postzygapophysis of the atlas and extended to the spinous process of the axis (C2). The C2-C3 intertransversales muscle were extended from the postzygapophysis of C2 and the one of C3. The three muscles covered the dorsal interspaces among C0-C3, and meantime they were closely connected with dense connective tissues, which filled in these interspaces. Each of these thick dense connective tissue membranes sent off several short and strong fibrous bundles ventrally to merge with the cervical spinal dura mater. Furthermore the connective tissues connecting these muscles with cervical spinal dura mater directly were revealed under the microscopy and they consisted of parallel and intensive collagen fibers with orientation from dorsal to ventral. In conclusion, this study for the first time demonstrated the existence of the MDB in the testudines, in all of the dorsal atlantooccipital, atlantoaxial and C2-C3 intervertebral spaces. Based on our results and comparative anatomical evidences in recent year, it could be inferred that the MDB might be its highly conserved structure in the evolution of amniota.

Se confirma que el puente miodural (PMD) conecta la mayoría de los músculos suboccipitales con la duramadre cervical a través de los espacios intervertebrales posteriores y existe ampliamente en mamíferos y aves. Para revelar si el MDB existe universalmente en la amniota de vertebrados, exploramos la existencia y las características morfológicas del PMD en Trachemys scripta elegans. Veinte muestras se observaron mediante disección anatómica y análisis histológico. En los resultados, se encontraron tres tipos de músculos en la región occipital. El músculo recto capitis dorsum minor se originó en el margen posterior del occipital (C0) y terminó en el proceso espinoso del atlas (C1). El músculo transverso espinal se unió al arco vertebral y el proceso del atlas y se extendió al proceso espinoso del axis (C2). El músculo intertransversario C2-C3 se extendió entre los procesos transversos de C2 y el de C3. Los tres músculos cubrían los espacios intermedios dorsales entre C0-C3 y, mientras tanto, estaban estrechamente conectados con tejidos conectivos densos, que rellenaban estos espacios. Cada una de estas membranas densas de tejido conectivo envían varios haces fibrosos cortos y fuertes ventralmente para fusionarse con la duramadre espinal cervical. Además, los tejidos conectivos que conectan estos músculos con la duramadre cervical y espinal se revelaron directamente bajo microscopía y consistían en intensas fibras de colágeno, paralelas, con orientación desde dorsal a ventral. En conclusión, este estudio demostró por primera vez la existencia del PMD en los estudios de prueba, en todos los espacios dorsales atlantooccipital, atlantoaxial e intervertebral C2-C3. Sobre la base de nuestros resultados y las evidencias anatómicas comparativas de los últimos años, se podría inferir que el PMD podría ser una estructura altamente conservada en la evolución de la amniota.

Anatomia comparativa da dura-máter de Sapajus libidinosus / Comparative anatomy of dura-mater of Sapajus libidinosus

O Sapajus libidinosus é um primata do novo mundo popularmente conhecido como macaco-prego, geograficamente distribuído por todo território sul-americano, possui características de inquietude e habilidade de manipulação de ferramentas para a obtenção de alimentos. Este estudo teve por objetivo descrever a morfologia dos seios da dura-máter de Sapajus libidinosus numa perspectiva comparativa. Foram utilizados um total de 3 animais adultos e machos oriundos da Universidade Federal de Goiás e fixados em solução aquosa de formaldeído 10%. No encéfalo de S. libidinosus, foi possível observar a fissura longitudinal, profunda e que divide o mesmo em dois hemisférios, esquerdo e direito. O lobo parietal e frontal apresenta-se relativamente lisoencefálico, mas com giros e sulcos bem definidos e no lobo occipital nota-se a predominância do aspecto lisencefálico. Nota-se a presença de 8 seios da dura-máter, que corresponde de modo geral às descrições para outros primatas como Pan, Papio e homem. Notamos a presença dos seios sagital dorsal, seio sagital ventral, seio transverso, seio reto, seio sigmóide, seio temporal e seio basilar, que são semelhantes a Pan, Papio e homem, a presença do seio parietal semelhante à Saimiri sciureus e a ausência do seio occipital, assim como em Macaca mullata. No macaco prego não foram observados os seios intracavernosos, seio esfenoparietal, seio petroso superior, seio petroso inferior, sendo estes descritos em Pan, Papio e Homem. Sendo assim, estes dados demonstram uma possível maior proximidade evolutiva entre Papio e Pan em relação ao homem do que o macaco Sapajus.

Sapajus libidinosus is a new World primate commonly known as capuchin monkey, geographically distributed throughout South America, has characteristics of restlessness and ability to manipulate tools to obtain food. This study aimed to describe the morphology of the dural sinuses of S. libidinosus through a comparative perspective. We used 3 adult male from the Federal University of Goiás, Brazil, fixed in aqueous 10% formaldehyde. The longitudinal fissure in the brain extends deeply and divides the organ into two left right hemispheres, The frontal and parietal lobe presents relatively smooth surface, but with well-defined gyri and sulci. In the occipital lobe, however, smooth surface aspect prevails. We observed eight sinuses of the dura mater, sagittal dorsal, ventral sagittal, transverse, straight, sigmoid, basilar and temporal which corresponds generally to the descriptions of other primates as Pan, Papio and man. Furthermore, parietal sinus similar to Saimiri sciureus and absence of sinus occipital, as in Macaca mullata, were also recorded. In the capuchin monkey, intracavernous, sphenoparietal, superior petrosal and inferior petrosal sinuses, which are described in Pan, Papio and Man, were absent. Taken together, these data point to a possible grater evolutionary proximity to man of Papio and Pan as compared to Cebus.

Anatomia comparativa da dura-máter de Sapajus libidinosus / Comparative anatomy of dura-mater of Sapajus libidinosus

O Sapajus libidinosus é um primata do novo mundo popularmente conhecido como macaco-prego, geograficamente distribuído por todo território sul-americano, possui características de inquietude e habilidade de manipulação de ferramentas para a obtenção de alimentos. Este estudo teve por objetivo descrever a morfologia dos seios da dura-máter de Sapajus libidinosus numa perspectiva comparativa. Foram utilizados um total de 3 animais adultos e machos oriundos da Universidade Federal de Goiás e fixados em solução aquosa de formaldeído 10%. No encéfalo de S. libidinosus, foi possível observar a fissura longitudinal, profunda e que divide o mesmo em dois hemisférios, esquerdo e direito. O lobo parietal e frontal apresenta-se relativamente lisoencefálico, mas com giros e sulcos bem definidos e no lobo occipital nota-se a predominância do aspecto lisencefálico. Nota-se a presença de 8 seios da dura-máter, que corresponde de modo geral às descrições para outros primatas como Pan, Papio e homem. Notamos a presença dos seios sagital dorsal, seio sagital ventral, seio transverso, seio reto, seio sigmóide, seio temporal e seio basilar, que são semelhantes a Pan, Papio e homem, a presença do seio parietal semelhante à Saimiri sciureus e a ausência do seio occipital, assim como em Macaca mullata. No macaco prego não foram observados os seios intracavernosos, seio esfenoparietal, seio petroso superior, seio petroso inferior, sendo estes descritos em Pan, Papio e Homem. Sendo assim, estes dados demonstram uma possível maior proximidade evolutiva entre Papio e Pan em relação ao homem do que o macaco Sapajus. (AU)

Sapajus libidinosus is a new World primate commonly known as capuchin monkey, geographically distributed throughout South America, has characteristics of restlessness and ability to manipulate tools to obtain food. This study aimed to describe the morphology of the dural sinuses of S. libidinosus through a comparative perspective. We used 3 adult male from the Federal University of Goiás, Brazil, fixed in aqueous 10% formaldehyde. The longitudinal fissure in the brain extends deeply and divides the organ into two left right hemispheres, The frontal and parietal lobe presents relatively smooth surface, but with well-defined gyri and sulci. In the occipital lobe, however, smooth surface aspect prevails. We observed eight sinuses of the dura mater, sagittal dorsal, ventral sagittal, transverse, straight, sigmoid, basilar and temporal which corresponds generally to the descriptions of other primates as Pan, Papio and man. Furthermore, parietal sinus similar to Saimiri sciureus and absence of sinus occipital, as in Macaca mullata, were also recorded. In the capuchin monkey, intracavernous, sphenoparietal, superior petrosal and inferior petrosal sinuses, which are described in Pan, Papio and Man, were absent. Taken together, these data point to a possible grater evolutionary proximity to man of Papio and Pan as compared to Cebus. (AU)

Cavernous sinus medial wall: dural or fibrous layer? Systematic review of the literature.

The cavernous sinus (CS) has one of the most complex anatomical networks of the skull base and because of the diversity of its contents is involved in many pathological processes. Nevertheless, anatomical literature concerning the CS is still controversial, so a systematic literature review was performed to find out the microanatomy of the medial wall of the CS and its clinical importance on sellar pathologies. Experimental studies from English-language literature between 1996 and 2010 were identified in MEDLINE, LILACS, and Cochrane databases. After analysis, two tables were prepared exhibiting the major points of each article. Fourteen experimental studies were included in the tables. Four studies concluded that the medial wall of the CS is composed of a loose, fibrous structure, and the remaining ten presumed that the medial wall is formed by a dural layer that constitutes the lateral wall of the sella. The lack of definition standards and of methodological criteria led to variation in the results among different studies. Thus, this hindered results comparison, possibly explaining the different observations.

An experimental model for the study of craniofacial deformities / Modelo experimental para o estudo de deformidades craniofaciais

PURPOSE: To develop an experimental surgical model in rats for the study of craniofacial abnormalities. METHODS: Full thickness calvarial defects with 10x10-mm and 5x8-mm dimensions were created in 40 male NIS Wistar rats, body weight ranging from 320 to 420 g. The animals were equally divided into two groups. The periosteum was removed and dura mater was left intact. Animals were killed at 8 and 16 weeks postoperatively and cranial tissue samples were taken from the defects for histological analysis. RESULTS: Cranial defects remained open even after 16 weeks postoperatively. CONCLUSION: The experimental model with 5x8-mm defects in the parietal region with the removal of the periosteum and maintenance of the integrity of the dura mater are critical and might be used for the study of cranial bone defects in craniofacial abnormalities.(AU)

OBJETIVO: Desenvolver um modelo experimental em ratos para o estudo de deformidades craniofaciais. MÉTODOS: Foram realizados defeitos ósseos de espessura total com diâmetro de 5 x 8 mm e 10 x 10mm na calota craniana em 40 ratos, machos, NIS Wistar, com peso de 320 a 420 g divididos igualmente em dois grupos. O periósteo foi retirado e a dura-máter mantida intacta. Os animais foram sacrificados na 8ª e 16ª semana de pós-operatório e amostras de tecido ósseo foram extraídas para realização da análise histológica. RESULTADOS: Os defeitos cranianos permaneceram abertos mesmo após 16 semanas após a cirurgia. CONCLUSÃO: O modelo experimental com defeitos de 5x8mm na região parietal, com remoção do periósteo e manutenção da integridade da dura-máter são considerados críticos, e poderá ser utilizado para o estudo dos defeitos ósseos cranianos nas anomalias craniofaciais.(AU)

Surgical anatomy of the dural walls of the cavernous sinus.

The external structure of each cavernous sinus (CS) is made of four dural walls. The aim of this study was to describe the anatomy of the dural walls of the CS. We studied 42 adult cadaveric heads, fixed with formalin and injected with coloured silicon. The main findings were: (i) the lateral wall of the CS has two layers - the external, which is thick and pearly grey, and the internal, which is semi-transparent and containing the cranial nerves (CNs); (ii) the medial wall of the CS has two areas - sellar and sphenoidal, both made up of one dural layer only; and (iii) the superior wall of the CS is formed by three triangles - oculomotor, clinoid and carotid - CN III may be found in a cisternal space of the oculomotor triangle; and (iv) the posterior wall of the CS is made up of two dural layers - meningeal dura and periostic dura - and this wall is close to the vertical segment of CN VI.

The anatomy of the thoracic spinal canal investigated with magnetic resonance imaging.

BACKGROUND: We investigated, with magnetic resonance imaging, the distance of the dura mater to the spinal cord in patients without spinal or medullar disease at the 2nd, 5th, and 10th thoracic segments. METHODS: Fifty patients in the supine position underwent magnetic resonance imaging. Medial sagittal slices of the 2nd, 5th, and 10th thoracic segments were measured for the relative distances using the 1.5-T superconducting system (Gyroscan Intera, Philips Medical Systems, Best, the Netherlands). In 10 patients, the angles relative to the tangent at the insertion point on the skin were measured. RESULTS: The posterior dural-spinal cord distance is significantly greater at the midthoracic region (5th thoracic = 5.8 +/- 0.8 mm) than at the upper (2nd thoracic = 3.9 +/- 0.8 mm) and lower thoracic levels (10th thoracic = 4.1 +/- 1.0 mm) (P < 0.015). There were no differences between interspaces T2 and T10. There was no correlation between age and the measured distance between the dura mater and the spinal cord. The entry angle of the needle at T2 was 9.0 degrees +/- 2.5 degrees ; at T5, 45.0 degrees +/- 7.4 degrees ; and at T10, 9.5 degrees +/- 4.2 degrees . CONCLUSIONS: This study demonstrated that there is greater depth of the posterior subarachnoid space at the T2, T5, and T10 levels. The greater distance was found at T5.

Modified abbreviated transcavernous approach to basilar artery aneurysms--case report.

BACKGROUND: Endovascular procedures and direct surgical clipping are the main therapeutic modalities for managing of BAAs. Furthermore, giant or wide-necked aneurysms and those that involve the PCA or perforators at its neck usually are not embolized. CASE DESCRIPTION: A 55-year-old man presented to the emergency room complaining of sudden and intense headache. Neurological examination evidenced meningismus. Computed tomography disclosed a subarachnoid hemorrhage (Fisher grade III). Arteriograms revealed BAA, whose neck was partially obscured by the PCP. A standard pterional craniotomy was performed, followed by extensive drilling of the greater sphenoid wing. The neck was partially hidden by the PCP, and no proximal control was obtained without drilling the PCP and opening the CS (modified TcA). Drilling of the PCP was begun by cutting the overlying dura and extended caudally as much as possible. Next, opening of the roof of the CS was performed by incising the dura in the oculomotor trigone medial and parallel to the oculomotor nerve and lateral to ICA; the incision progressed posteriorly toward the dorsum sellae. Further resection of the dorsum sellae and clivus was carried out. After performing these steps, proximal control was obtained, aneurysm was deflated, perforators were saved, and aneurysm was clipped. CONCLUSIONS: This study has demonstrated the clinical usefulness of an abbreviated form of the TcA, which led the "modified TcA," in approaching complex low-lying BAA. It provides additional surgical room by removing the PCP and partially opening the CS, which permits further bone removal and improves exposure.

El saco dural humano. Morfología de la dura-aracnoides espinal. Origen del espacio subdural espinal / The human dural sac. Morphology of the spinal dura-arachnoid membrane. Origin of the spinal subdural space

Esta revisión resume los hallazgos encontrados en el saco dural de cadáveres de recién fallecidos estudiados con diferentes técnicas histológicas. El saco dural espinal está formado por tres estructuras concéntricas: la duramadre, que ocupa el 85-90 por ciento de su espesor, del lado externo; el compartimiento subdural, integrado por células neuroteliales, y la lámina aracnoidea, que ocupa el 5 al 8 por ciento interno. La duramadre, que consta de aproximadamente 80 láminas durales concéntricas, es una estructura permeable y fibrosa, por lo cual posee resistencia mecánica. El compartimiento subdural es una estructura concéntrica, celular, de resistencia mecánica muy baja, donde se pueden producir fisuras concéntricas por rotura de las células neuroteliales dando origen a un espacio subdural adquirido. La lámina aracnoidea es una estructura celular con mayor resistencia mecánica que el compartimiento subdural. Sus células están firmemente unidas por uniones especializadas de membrana y forman una barrera semipermeable que regula el pasaje de sustancias a través del espesor del saco dural.

El saco dural humano. Morfología de la dura-aracnoides espinal. Origen del espacio subdural espinal / The human dural sac. Morphology of the spinal dura-arachnoid membrane. Origin of the spinal subdural space

Esta revisión resume los hallazgos encontrados en el saco dural de cadáveres de recién fallecidos estudiados con diferentes técnicas histológicas. El saco dural espinal está formado por tres estructuras concéntricas: la duramadre, que ocupa el 85-90 por ciento de su espesor, del lado externo; el compartimiento subdural, integrado por células neuroteliales, y la lámina aracnoidea, que ocupa el 5 al 8 por ciento interno. La duramadre, que consta de aproximadamente 80 láminas durales concéntricas, es una estructura permeable y fibrosa, por lo cual posee resistencia mecánica. El compartimiento subdural es una estructura concéntrica, celular, de resistencia mecánica muy baja, donde se pueden producir fisuras concéntricas por rotura de las células neuroteliales dando origen a un espacio subdural adquirido. La lámina aracnoidea es una estructura celular con mayor resistencia mecánica que el compartimiento subdural. Sus células están firmemente unidas por uniones especializadas de membrana y forman una barrera semipermeable que regula el pasaje de sustancias a través del espesor del saco dural. (AU)

Contribuição ao estudo anatômico da dura-máter do Bradypus torquatus (Linnaeus, 1758) e Bradypus variegatus (Schinz, 1825) / Contribution to the anatomic study of the dura-mater of the Bradypus torquatus (Linnaeus, 1758) e Bradypus variegatus (Schinz, 1825)

Pesquisas em neurociências têm contribuído para elucidar a história dos animais na terra, contudo diversos animais silvestres da América do sul ainda não foram estudados. O bicho preguiça, ameaçado de extinção, por sua alta especificidade e especialização alimentar pode nos fornecer informações sobre a história evolutiva animal. Utilizamos animais mortos naturalmente, sendo congelados, fixados e injetados com látex natural na reserva da Marinha, Itabuna/llhéus, cedidos para projetos em parceria entre a reserva, Universidade de São Paulo e outras instituições. As dissecações foram realizadas com auxilio de lupas e, após documentação, descritas e analisadas pelo referencial a disposição. Não é abundante a literatura sobre o tema e, por isso, utilizamos descrições e sistematizações em humanos e outros mamíferos como base para as discussões. Na dura-máter, foi encontrada uma estrutura semelhante à descrita em mamíferos, com foice do cérebro e tenda do cerebelo, além de seios venosos. Tais seios apresentaram alterações interessantes em sua formação, todas adequadas às características anatômicas de seu cérebro, entre elas um seio orbículo frontal em tomo da base dos bulbos olfatórios, um seio para-sagital cerebelar no lugar de uma veia cerebelar como descrito por diversos autores e uma conexão entre os seios transversos por meio de um seio inter-transverso. Finalmente, uma peculiaridade neste sistema é o deslocamento do seio sigmóide no sentido caudo-rostral, drenando o aporte sangüíneo da porção rostral do encéfalo, em especial do aparato olfatório.

Contribuição ao estudo anatômico da dura-máter do Bradypus torquatus (Linnaeus, 1758) e Bradypus variegatus (Schinz, 1825) / Contribution to the anatomic study of the dura-mater of the Bradypus torquatus (Linnaeus, 1758) e Bradypus variegatus (Schinz, 1825)

Pesquisas em neurociências têm contribuído para elucidar a história dos animais na terra, contudo diversos animais silvestres da América do sul ainda não foram estudados. O bicho preguiça, ameaçado de extinção, por sua alta especificidade e especialização alimentar pode nos fornecer informações sobre a história evolutiva animal. Utilizamos animais mortos naturalmente, sendo congelados, fixados e injetados com látex natural na reserva da Marinha, Itabuna/llhéus, cedidos para projetos em parceria entre a reserva, Universidade de São Paulo e outras instituições. As dissecações foram realizadas com auxilio de lupas e, após documentação, descritas e analisadas pelo referencial a disposição. Não é abundante a literatura sobre o tema e, por isso, utilizamos descrições e sistematizações em humanos e outros mamíferos como base para as discussões. Na dura-máter, foi encontrada uma estrutura semelhante à descrita em mamíferos, com foice do cérebro e tenda do cerebelo, além de seios venosos. Tais seios apresentaram alterações interessantes em sua formação, todas adequadas às características anatômicas de seu cérebro, entre elas um seio orbículo frontal em tomo da base dos bulbos olfatórios, um seio para-sagital cerebelar no lugar de uma veia cerebelar como descrito por diversos autores e uma conexão entre os seios transversos por meio de um seio inter-transverso. Finalmente, uma peculiaridade neste sistema é o deslocamento do seio sigmóide no sentido caudo-rostral, drenando o aporte sangüíneo da porção rostral do encéfalo, em especial do aparato olfatório.(AU)

Neurosciences research have contribution to elucidate the history ofthe animal on the earth, nevertheless many sylvan animals, in SouthAmerica yet wont be studied. The Sloths, in risk of extinction, becauseyour high specificity and alimentary specialization can give usinformation about evolutive animal history. We use dead animals bynatural process, freeze, fixed and injected by natural latex in Matinha´sreserve, Itabuna/Ilhéus, ceded for projects in association between the reserve, São Paulo University and other institutions. Thedissections were realized by magnified glass succors, documented,descript and analyzed by the references. We dont have many referencesabout the theme thus were utilized descriptions and systematizationsin humans and other mammals as the base for discussions. In thedura-mater was found a similar structure in other mammals, withfalx´s brain and cerebelar tent , over there venous sinus. This sinusshow interests alterations in your formations, all adequate to youranatomic characteristics of your brain, among these a orbiculo-frontalsinus around the base of olfactory bulbs, a sinus para-sagital cerebelarin a place of a cerebelar vein like description for many authors, and aconnection between transverse sinus and inter-transverse sinus. Finallya peculiarity in this system is a transposition of the sigmoid sinus ina caudo-rostral orientation draining the blood support of the rostralregion of the brain, specially the olfactory set. (AU)

Anatomical landmarks for hemispherotomy and their clinical application.

OBJECT: The authors introduce the surgical concept of the central core of a hemisphere, from which anatomical structures are disconnected during most current hemispherotomy techniques. They also propose key anatomical landmarks for hemispherotomies that can be used to disconnect the hemisphere from its lateral surface around the insula, through the lateral ventricle toward the midline. METHODS: This anatomical study was performed in five adult cadaveric heads following perfusion of the cerebral arteries and veins with colored latex. Anatomical landmarks were used in five hemispheric deafferentations. The central core of a hemisphere consists of extreme, external, and internal capsules; claustrum; lentiform and caudate nuclei; and thalamus. Externally, this core is covered by the insula and surrounded by the fornix, choroid plexus, and lateral ventricle. During most hemispherotomies, the surgeon reaches the lateral ventricle through the frontoparietal opercula or temporal lobe; removes the mesial temporal structures; and disconnects the frontal lobe ahead, the parietal and occipital lobes behind, and the intraventricular fibers of the corpus callosum above the central core. After a temporal lobectomy, the landmarks include the choroid plexus and posterior/ascending portion of the tentorium to disconnect the parietal and occipital lobes, the callosal sulcus or distal anterior cerebral artery (ACA) to sever the intraventricular fibers of the corpus callosum, and the head of the caudate nucleus and ACA to detach the frontal lobe. CONCLUSIONS: These landmarks can be used in any hemispherotomy during which a cerebral hemisphere is disconnected from its lateral surface. Furthermore, they can be used to perform any resection around the central core of the hemisphere and the tentorial incisura.

Enxertos homólogos de esclera e dura-mater em olhos de coelhos: análise histopatoógica comparativa / Homologous sclera and dura mater grafts in rabbiteyes: a comparative histopathological analysis

Para analisar comparativamente, qualitativa e semiquantitativamente, a reação tecidual ao emprego de enxertos homólogos de esclera e dura-máter em olhos de coelhos, foram realizadas cirurgias experimentais em 39 coelhos albinos fêmeas da raça Nova Zelândia. Os olhos foram enucleados e amostras foram colhidas em duas, seis e 12 semanas após o experimento. O enxerto de dura-máter mostrou intensa reabsorção e progressiva substituição por tecido conjuntivo frouxo. O enxerto de esclera mostrou discreta reabsorção na periferia com formação de membrana fibrosa, integrando este à esclera do hospedeiro /A comparative, qualitative and semi-quantitative analysis was made of the tissular reaction to the use of homologous grafts of sclera and dura mater in rabbit eyes. Experimental surgeries were performed in 39 female, albino New Zealand rabbits. The eyes were enucleated and samples collected two, six and 12 weeks after the experiment. The dura mater graft showed intense absorption and progressive substitution by loose connective tissue. The sclera graft presented a discrete absorption in the periphery with formation of a fibrous membrane, becoming integrated with the sclera of the host...