To evaluate structural variations of the jugular tubercles (JTs) and their relationships with the vertebral artery, the posterior inferior cerebellar artery (PICA), and the vertebrobasilar junction ...(VBJ).
The depth, height, and width of the JTs were measured using 30 cadaveric basicranial specimens and 50 three-dimensional angiography computed tomographic (angio-CT) scans evaluating morphological variations between the 2 sides. Angio-CT analysis evaluated the relationships of the JTs with the vertebral arteries and the PICAs. The location of the VBJ with respect to the JT level in the coronal plane was evaluated.
In the cadaveric specimens, the mean JT depth ranged from 0.9 to 3.1 cm, the mean height ranged from 0.6 to 1.5 cm, and the mean width ranged from 0.4 to 1.2 cm. According to the 3-dimensional angio-CT scans, JT measurements ranged as follows: depth, 0.7 to 2.6 cm; height, 0.6 to 1.4 cm; and width, 0.3 to 1.2 cm. The vertebral artery was in close contact with the JT on the left side in 30% of cases and on the right side in 24% of the cases. On axial scans, the PICA origin was classified as anterior to the JT in 20.5% of patients on the left side and 17.4% on the right, at the JT level in 50% of patients on the left side and 45.7% on the right, and posterior to the JT in 29.5% of patients on the left side and 36.9% on the right. On coronal scans, the PICA origin was classified as superior to the JT in 13.6% of patients on the left side and 8.7% on the right, at the JT level in 54.6% of patients on the left side and 50% on the right, and inferior to the JT in 31.8% of patients on the left side and 41.3% on the right. In the coronal plane, the VBJ was located above the tubercles in 16 patients (32%), at the JT level in 28 patients (56%), and below the tubercles in 6 patients (12%).
A precise morphometric analysis of the JTs on 3-dimensional CT scans was quick and safe and showed significant variations in their size and shape. The relationship of the JT with vertebral artery and the PICA varied significantly, as well as with the VBJ location. Knowledge of these morphological variations can contribute to optimal preoperative surgical planning, minimizing retraction and reducing morbidity during extreme lateral infrajugular-transtubercular exposure surgery.
Background:
Microscopic microvascular decompression (MVD) has a low but not negligible failure rate due to some missed conflicts, especially in case of multiple offending vessels. The reported study ...is aimed to assess the principles, methodology, technical notes, and effectiveness of the endoscope-assisted (EA) MVD for neurovascular compression syndromes (NVCS) in the posterior fossa.
Materials and Methods:
A series of 43 patients suffering from an NVCS and undergone to an EA MVD were retrospectively reviewed. Syndromes were trigeminal neuralgia in 25 cases, hemifacial spasm in nine cases, positional vertigo in six cases, glossopharyngeal neuralgia in two cases, and spasmodic torticollis in one case. In all cases, a 0°–30° specially designed endoscope was inserted into the surgical field to find/treat those conflicts missed by the microscopic exploration. Each procedure was judged in terms of the effectiveness of the adjunct of the endoscope according to a three types classification system: Type I – improvement in the visualization of the nerve's root entry/exit zone; Type II – endoscopic detection of one or more conflicts involving the ventral aspects of the nerve and missed by the microscope; Type III – endoscope-controlled release of the neurovascular conflict otherwise difficult to treat under the only microscopic view.
Results:
A total of 55 conflicts were found and treated. Twenty-eight procedures were classified as Type I, nine as Type II, and six as Type III. All the patients had a full recovery from their symptoms.
Conclusions:
In selected cases, EA MVD offers some advantages in the detection and treatment of neurovascular conflicts in the posterior fossa.
The ventriculus terminalis (VT) is a small ependyma-lined cavity within the conus medullaris that is in direct continuity with the central canal of the anterior portion of the spinal cord. Normally, ...such a cavity is identifiable only histologically in children and adults and can be visualized using common neuroradiological techniques only after dilation. Currently, the mechanisms of isolated dilation are not documented. The present work describes 2 cases of VT in elderly patients. Data from a histological and ultrastructural study of a case of VT dilation are reported, and the results are compared with those obtained from the VT of 5 fetuses to explain the nosological aspects of nontumoral VT lesions. Our data suggest that the site, age, and histological characteristics of the lesion allow us to define VT dilation as a nosological entity distinct from other cystic dilations of the conus medullaris.
We develop a new four-phase tumor growth model with angiogenesis, derived from a diffuse-interface mixture model composed by a viable, a necrotic, a liquid and an angiogenetic component, coupled with ...two massless chemicals representing a perfectly diluted nutrient and an angiogenetic factor. This model is derived from variational principles complying with the second law of thermodynamics in isothermal situations, starting from biological constitutive assumptions on the tumor cells adhesion properties and on the infiltrative mechanics of tumor-induced vasculature in the tumor tissues, and takes the form of a coupled degenerate Cahn-Hilliard Keller-Segel system for the mixture components with reaction diffusion equations for the chemicals. The model is informed by neuroimaging data, which give informations about the patient-specific brain geometry and tissues microstructure, the distribution of the different tumor components, the white matter fiber orientations and the vasculature density. We describe specific and robust preprocessing steps to extract quantitative informations from the neuroimaging data and to construct a computational platform to solve the model on a patient-specific basis. We introduce a finite element approximation of the model which preserve the qualitative properties of the continuous solutions. Finally, we show simulation results for the patient-specific tumor evolution of a patient affected by GlioBlastoma Multiforme, considering two different test cases before surgery, corresponding to situations with high or low nutrient supply inside the tumor, and a test case after surgery. We show that our model correctly predicts the overall extension of the tumor distribution and the intensity of the angiogenetic process, paving the way for assisting the clinicians in properly assessing the therapy outcomes and in designing optimal patient-specific therapeutic schedules.
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