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R. Shane Tubbs - One of the best experts on this subject based on the ideXlab platform.
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A hugely elevated torcular Herophili
Child's Nervous System, 2020Co-Authors: Kennedy Carpenter, Joe Iwanaga, Aaron S. Dumont, R. Shane TubbsAbstract:The torcular Herophili is formed by the joining of the major dural venous Sinuses including the superior sagittal Sinus, transverse Sinuses, straight Sinuses, and the Occipital Sinus. Surgically, knowledge of the position of the torcular Herophili is vitally important to avoid catastrophic hemorrhage. Here, we present a case report of an elevated torcularia found on radiological imaging. Such an anatomical variation should be kept in mind by clinicians and anatomists alike.
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The Torcular Herophili (Confluence of Sinuses)
Anatomy Imaging and Surgery of the Intracranial Dural Venous Sinuses, 2020Co-Authors: Andre Granger, R. Shane TubbsAbstract:Abstract The torcular Herophili (confluence of Sinuses) is a highly variable structure that constitutes a vital part of the network of dural venous Sinuses. The torcular Herophili is defined historically as the intersection of the superior sagittal Sinus, the straight Sinus, the Occipital Sinus, and the two transverse Sinuses. Its size varies and it is located inferior to the Occipital lobes and posterosuperiomedially to the cerebellum. This chapter outlines the anatomy and clinical implications of this Sinus.
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The Occipital Sinus
Anatomy Imaging and Surgery of the Intracranial Dural Venous Sinuses, 2020Co-Authors: Pamela Youssef, R. Shane TubbsAbstract:Abstract Among the dural venous Sinuses, the Occipital Sinus is one of those studied least. One reason for this might be its absence in a significant number of people with no clinical sequelae; another reason may be the high degree of variation that it exhibits, which is discussed later. This chapter details the anatomy, variations, and clinical significance of this intradural venous Sinus.
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Intracranial Connections of the Vertebral Venous Plexus: Anatomical Study with Application to Neurosurgical and Endovascular Procedures at the Craniocervical Junction.
Operative neurosurgery (Hagerstown Md.), 2017Co-Authors: R. Shane Tubbs, Marios Loukas, Joel K. Curé, Amin Demerdash, Rod J. Oskouian, Shaheryar F. Ansari, Aaron A. Cohen-gadolAbstract:Background Descriptions of intracranial extensions of vertebral venous plexuses are lacking. Objective To identify vertebral venous plexuses at the craniocervical junction in cadavers and describe them. Methods The authors dissected 15 ink-injected, formalin-fixed, adult cadaveric heads and measured cranial extensions of the spinal venous plexuses. Results All specimens had vertebral venous plexuses at the craniocervical junction composed of multiple interwoven vessels concentrated anteriorly (anterior vertebral plexuses), posteriorly (posterior vertebral venous plexuses), and laterally (lateral vertebral venous plexuses). Veins making up the plexus tended to be largest for the anterior internal vertebral venous plexus. On 33%, a previously unnamed lateral internal vertebral venous plexus was identified that connected to the lateral marginal Sinus. The anterior external vertebral venous plexus connected to the basilar venous plexus via transclival emissary veins in 13%; remaining veins connected either intracranially via small perforating branches through the anterior atlanto-Occipital membrane (33%) or had no direct gross connections inside the cranium (53%). The anterior internal vertebral plexus, which traveled between layers of the posterior longitudinal ligament, connected to the anterior half of the marginal Sinus in 33% and anterolateral parts of the marginal Sinus in 20%. The posterior internal venous plexus connected to the posterior aspect of the marginal Sinus on 80% and into the Occipital Sinus in 13.3%. The posterior external venous plexus connected to veins of the hypoglossal canal in 20% and into the posterior aspect of the marginal Sinus in 13.3%. Conclusion Knowledge of these connections is useful to neurosurgeons and interventional radiologists.
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The oblique Occipital Sinus: a review of anatomy and imaging characteristics
Surgical and Radiologic Anatomy, 2011Co-Authors: R. Shane Tubbs, Anand N. Bosmia, Mohammadali M. Shoja, Marios Loukas, Joel K. Curé, Aaron A. Cohen-gadolAbstract:Variations of the dural venous Sinuses may result in inaccurate imaging interpretation or complications during surgical approaches. One variation of the dural venous Sinuses reported infrequently in the literature is the oblique Occipital Sinus. The present paper reviews this anatomy and offers illustrations of the cadaveric and imaging findings seen with this venous variation.
Kazunari Yoshida - One of the best experts on this subject based on the ideXlab platform.
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Fate of the three embryonic dural Sinuses in infants: the primitive tentorial Sinus, Occipital Sinus, and falcine Sinus
Neuroradiology, 2018Co-Authors: Katsuhiro Mizutani, Tomoru Miwa, Takenori Akiyama, Yoshiaki Sakamoto, Hirokazu Fujiwara, Kazunari YoshidaAbstract:Purpose The primitive tentorial, Occipital, and falcine Sinuses are thought to attain the adult pattern or regress between the fetal stage and adulthood. The anatomy of these three primitive dural Sinuses has seldom been studied in the infant population, and it remains unclear when these dural Sinuses reach the adult condition. Using computed tomography digital subtraction venography (CT-DSV), we analyzed the anatomy of these embryonic dural Sinuses in infants. Methods We included 13 infants who underwent CT-DSV prior to neurosurgery and 35 cases with unruptured cerebral aneurysms as normal adult controls. Three embryonic dural Sinuses, i.e., the primitive tentorial, Occipital, and falcine Sinuses, were retrospectively analyzed in CT-DSV images of infants and adults. We also analyzed the drainage patterns of the superficial middle cerebral vein (SMCV), determined by the connection between the primitive tentorial Sinus and the cavernous Sinus. Results The primitive tentorial, Occipital, and falcine Sinuses were present in 15.4%, 46.2%, and none of the infants, respectively, and in 10.0, 8.6, and 2.9% of the adults, respectively. The difference in SMCV draining pattern between infants and adults was insignificant. The incidence of the Occipital Sinus was significantly higher in infants than in adults. Conclusions The connection between the primitive tentorial Sinus and the cavernous Sinus appears to be established before birth. The Occipital Sinus is formed at the embryonic stage and mostly regresses after infancy. The falcine Sinus is usually obliterated prenatally. Our findings form the basis for interventions by pediatric interventional neuroradiologists and neurosurgeons.
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Fate of the three embryonic dural Sinuses in infants: the primitive tentorial Sinus, Occipital Sinus, and falcine Sinus
Neuroradiology, 2018Co-Authors: Katsuhiro Mizutani, Tomoru Miwa, Takenori Akiyama, Yoshiaki Sakamoto, Hirokazu Fujiwara, Kazunari YoshidaAbstract:The primitive tentorial, Occipital, and falcine Sinuses are thought to attain the adult pattern or regress between the fetal stage and adulthood. The anatomy of these three primitive dural Sinuses has seldom been studied in the infant population, and it remains unclear when these dural Sinuses reach the adult condition. Using computed tomography digital subtraction venography (CT-DSV), we analyzed the anatomy of these embryonic dural Sinuses in infants. We included 13 infants who underwent CT-DSV prior to neurosurgery and 35 cases with unruptured cerebral aneurysms as normal adult controls. Three embryonic dural Sinuses, i.e., the primitive tentorial, Occipital, and falcine Sinuses, were retrospectively analyzed in CT-DSV images of infants and adults. We also analyzed the drainage patterns of the superficial middle cerebral vein (SMCV), determined by the connection between the primitive tentorial Sinus and the cavernous Sinus. The primitive tentorial, Occipital, and falcine Sinuses were present in 15.4%, 46.2%, and none of the infants, respectively, and in 10.0, 8.6, and 2.9% of the adults, respectively. The difference in SMCV draining pattern between infants and adults was insignificant. The incidence of the Occipital Sinus was significantly higher in infants than in adults. The connection between the primitive tentorial Sinus and the cavernous Sinus appears to be established before birth. The Occipital Sinus is formed at the embryonic stage and mostly regresses after infancy. The falcine Sinus is usually obliterated prenatally. Our findings form the basis for interventions by pediatric interventional neuroradiologists and neurosurgeons.
Katsuhiro Mizutani - One of the best experts on this subject based on the ideXlab platform.
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Fate of the three embryonic dural Sinuses in infants: the primitive tentorial Sinus, Occipital Sinus, and falcine Sinus
Neuroradiology, 2018Co-Authors: Katsuhiro Mizutani, Tomoru Miwa, Takenori Akiyama, Yoshiaki Sakamoto, Hirokazu Fujiwara, Kazunari YoshidaAbstract:Purpose The primitive tentorial, Occipital, and falcine Sinuses are thought to attain the adult pattern or regress between the fetal stage and adulthood. The anatomy of these three primitive dural Sinuses has seldom been studied in the infant population, and it remains unclear when these dural Sinuses reach the adult condition. Using computed tomography digital subtraction venography (CT-DSV), we analyzed the anatomy of these embryonic dural Sinuses in infants. Methods We included 13 infants who underwent CT-DSV prior to neurosurgery and 35 cases with unruptured cerebral aneurysms as normal adult controls. Three embryonic dural Sinuses, i.e., the primitive tentorial, Occipital, and falcine Sinuses, were retrospectively analyzed in CT-DSV images of infants and adults. We also analyzed the drainage patterns of the superficial middle cerebral vein (SMCV), determined by the connection between the primitive tentorial Sinus and the cavernous Sinus. Results The primitive tentorial, Occipital, and falcine Sinuses were present in 15.4%, 46.2%, and none of the infants, respectively, and in 10.0, 8.6, and 2.9% of the adults, respectively. The difference in SMCV draining pattern between infants and adults was insignificant. The incidence of the Occipital Sinus was significantly higher in infants than in adults. Conclusions The connection between the primitive tentorial Sinus and the cavernous Sinus appears to be established before birth. The Occipital Sinus is formed at the embryonic stage and mostly regresses after infancy. The falcine Sinus is usually obliterated prenatally. Our findings form the basis for interventions by pediatric interventional neuroradiologists and neurosurgeons.
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Fate of the three embryonic dural Sinuses in infants: the primitive tentorial Sinus, Occipital Sinus, and falcine Sinus
Neuroradiology, 2018Co-Authors: Katsuhiro Mizutani, Tomoru Miwa, Takenori Akiyama, Yoshiaki Sakamoto, Hirokazu Fujiwara, Kazunari YoshidaAbstract:The primitive tentorial, Occipital, and falcine Sinuses are thought to attain the adult pattern or regress between the fetal stage and adulthood. The anatomy of these three primitive dural Sinuses has seldom been studied in the infant population, and it remains unclear when these dural Sinuses reach the adult condition. Using computed tomography digital subtraction venography (CT-DSV), we analyzed the anatomy of these embryonic dural Sinuses in infants. We included 13 infants who underwent CT-DSV prior to neurosurgery and 35 cases with unruptured cerebral aneurysms as normal adult controls. Three embryonic dural Sinuses, i.e., the primitive tentorial, Occipital, and falcine Sinuses, were retrospectively analyzed in CT-DSV images of infants and adults. We also analyzed the drainage patterns of the superficial middle cerebral vein (SMCV), determined by the connection between the primitive tentorial Sinus and the cavernous Sinus. The primitive tentorial, Occipital, and falcine Sinuses were present in 15.4%, 46.2%, and none of the infants, respectively, and in 10.0, 8.6, and 2.9% of the adults, respectively. The difference in SMCV draining pattern between infants and adults was insignificant. The incidence of the Occipital Sinus was significantly higher in infants than in adults. The connection between the primitive tentorial Sinus and the cavernous Sinus appears to be established before birth. The Occipital Sinus is formed at the embryonic stage and mostly regresses after infancy. The falcine Sinus is usually obliterated prenatally. Our findings form the basis for interventions by pediatric interventional neuroradiologists and neurosurgeons.
Gary Wilson - One of the best experts on this subject based on the ideXlab platform.
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Blood-respiratory and acid–base changes during extended diving in the bimodally respiring freshwater turtle Rheodytes leukops
Journal of Comparative Physiology B, 2004Co-Authors: Matthew A. Gordos, Craig E. Franklin, Colin J. Limpus, Gary WilsonAbstract:Changes in blood-gas, acid–base, and plasma-ion status were investigated in the bimodally respiring turtle, Rheodytes leukops , during prolonged dives of up to 12 h. Given that R. leukops routinely submerges for several hours, the objective of this study was to determine whether voluntarily diving turtles remain aerobic and simultaneously avoid hypercapnic conditions over increasing dive lengths. Blood PO_2, PCO_2, and pH, as well as plasma concentrations of lactate, glucose, Na^+, K^+, Cl^−, total Ca, and total Mg were determined in venous blood collected from the Occipital Sinus. Blood PO_2 declined significantly with dive length; however, oxy-haemoglobin saturation remained greater than 30% for all R. leukops sampled. No changes were observed in blood PCO_2, pH, [HCO_3 ^−], or plasma glucose, with increasing dive length. Despite repeated dives lasting more than 2 h, plasma lactate remained less than 3 mmol l^−1 for all R. leukops sampled, indicating the absence of anaerobiosis. Compensatory acid–base adjustments associated with anaerobiosis (e.g. declining [Cl^−], increasing total [Ca] and [Mg]) were likewise absent, with plasma-ion concentrations remaining stable with increasing dive length. Results indicate that R. leukops utilises aquatic respiration to remain aerobic during prolonged dives, thus effectively avoiding the development of a metabolic and respiratory acidosis.
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Blood-respiratory and acid-base changes during extended diving in the bimodally respiring freshwater turtle Rheodytes leukops.
Journal of comparative physiology. B Biochemical systemic and environmental physiology, 2004Co-Authors: Matthew A. Gordos, Craig E. Franklin, Colin J. Limpus, Gary WilsonAbstract:Changes in blood-gas, acid-base, and plasma-ion status were investigated in the bimodally respiring turtle, Rheodytes leukops, during prolonged dives of up to 12 h. Given that R. leukops routinely submerges for several hours, the objective of this study was to determine whether voluntarily diving turtles remain aerobic and simultaneously avoid hypercapnic conditions over increasing dive lengths. Blood PO2, PCO2, and pH, as well as plasma concentrations of lactate, glucose, Na+, K+, Cl-, total Ca, and total Mg were determined in venous blood collected from the Occipital Sinus. Blood PO2 declined significantly with dive length; however, oxy-haemoglobin saturation remained greater than 30% for all R. leukops sampled. No changes were observed in blood PCO2, pH, [HCO3-], or plasma glucose, with increasing dive length. Despite repeated dives lasting more than 2 h, plasma lactate remained less than 3 mmol l(-1) for all R. leukops sampled, indicating the absence of anaerobiosis. Compensatory acid-base adjustments associated with anaerobiosis (e.g. declining [Cl-], increasing total [Ca] and [Mg]) were likewise absent, with plasma-ion concentrations remaining stable with increasing dive length. Results indicate that R. leukops utilises aquatic respiration to remain aerobic during prolonged dives, thus effectively avoiding the development of a metabolic and respiratory acidosis.
Concezio Di Rocco - One of the best experts on this subject based on the ideXlab platform.
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Occipital Sinus pericranii superseding both jugular veins: description of two rare pediatric cases.
Neurosurgery, 2013Co-Authors: Paolo Frassanito, Luca Massimi, Gianpiero Tamburrini, Massimo Caldarelli, Alessandro Pedicelli, Concezio Di RoccoAbstract:The extracranial venous drainage of the brain is provided mainly by the jugular veins with the variable participation of extrajugular pathways. Two cases of Occipital Sinus pericranii (SP) were observed. A 6-year-old girl presented with a progressively enlarging Occipital lump; she was otherwise asymptomatic. An 8-year-old boy presented with mild nuchal headache. In the former case, neuroimaging examinations confirmed the diagnosis of SP; in the latter, SP was noticed on magnetic resonance imaging because it was neglected at physical examination. In both subjects, the radiological examination also showed bilateral occlusion of the jugular veins with ventricular dilation and herniation of cerebellar tonsils into the foramen magnum. Exceptionally, SP was noticed to represent the main venous drainage of the underlying brain, thereby compensating for the intracranial hypertension due to venous engorgement. Preservation of SP was advised, and any surgical or endovascular treatment was contraindicated.
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Occipital Sinus pericranii superseding both jugular veins: description of two rare pediatric cases.
Neurosurgery, 2013Co-Authors: Paolo Frassanito, Luca Massimi, Gianpiero Tamburrini, Massimo Caldarelli, Alessandro Pedicelli, Concezio Di RoccoAbstract:Background and importance The extracranial venous drainage of the brain is provided mainly by the jugular veins with the variable participation of extrajugular pathways. Clinical presentation Two cases of Occipital Sinus pericranii (SP) were observed. A 6-year-old girl presented with a progressively enlarging Occipital lump; she was otherwise asymptomatic. An 8-year-old boy presented with mild nuchal headache. In the former case, neuroimaging examinations confirmed the diagnosis of SP; in the latter, SP was noticed on magnetic resonance imaging because it was neglected at physical examination. In both subjects, the radiological examination also showed bilateral occlusion of the jugular veins with ventricular dilation and herniation of cerebellar tonsils into the foramen magnum. Conclusion Exceptionally, SP was noticed to represent the main venous drainage of the underlying brain, thereby compensating for the intracranial hypertension due to venous engorgement. Preservation of SP was advised, and any surgical or endovascular treatment was contraindicated.
