Endoscopic Resection of Skull Base Teratoma in Klippel-Feil Syndrome through Use of Combined Ultrasonic and Bipolar Diathermy Platforms

PubMed Central

Psaltis, Alkis J.; Williams, Ryan A.; Charville, Gregory W.; Dodd, Robert L.

2017-01-01

Klippel-Feil syndrome (KFS) is associated with numerous craniofacial abnormalities but rarely with skull base tumor formation. We report an unusual and dramatic case of a symptomatic, mature skull base teratoma in an adult patient with KFS, with extension through the basisphenoid to obstruct the nasopharynx. This benign lesion was associated with midline palatal and cerebral defects, most notably pituitary and vertebrobasilar arteriolar duplications. A multidisciplinary workup and a complete endoscopic, transnasal surgical approach between otolaryngology and neurosurgery were undertaken. Out of concern for vascular control of the fibrofatty dense tumor stalk at the skull base and need for complete teratoma resection, we successfully employed a tissue resection tool with combined ultrasonic and bipolar diathermy to the tumor pedicle at the sphenoid/clivus junction. No CSF leak or major hemorrhage was noted using this endonasal approach, and no concerning postoperative sequelae were encountered. The patient continues to do well now 3 years after tumor extirpation, with resolution of all preoperative symptoms and absence of teratoma recurrence. KFS, teratoma biology, endocrine gland duplication, and the complex considerations required for successfully addressing this type of advanced skull base pathology are all reviewed herein. PMID:28133560

The inferior turbinate flap in skull base reconstruction

PubMed Central

2013-01-01

Background As the indications for expanded endonasal approaches continue to evolve, alternative reconstructive techniques are needed to address increasingly complex surgical skull base defects. In the absence of the nasoseptal flap, we describe our experience with the posterior pedicle inferior turbinate flap (PPITF) in skull base reconstruction. Design Case series. Setting Academic tertiary care centre. Methods Patients who underwent reconstruction of the skull base with the PPITF were identified. Medical records were reviewed for demographic, presentation, treatment, follow-up, surgical and outcomes data. Main outcome measures Flap survival, adequacy of seal, and complications. Results Two patients with residual/recurrent pituitary adenomas met the inclusion criteria. The nasoseptal flap was unavailable in each case due to a prior septectomy. Salvage of the original nasoseptal flap was not possible, as it did not provide adequate coverage of the resultant defect due to contraction from healing. All PPITFs healed uneventfully and covered the entire defect. No complications were observed in the early post-operative period. Endoscopic techniques and limitations of the PPITF are also discussed. Conclusions Our clinical experience supports the PPITF to be a viable alternative for reconstruction of the skull base in the absence of the nasoseptal flap. PMID:23663897

Effect of skull flexural properties on brain response during dynamic head loading - biomed 2013.

PubMed

Harrigan, T P; Roberts, J C; Ward, E E; Carneal, C M; Merkle, A C

2013-01-01

The skull-brain complex is typically modeled as an integrated structure, similar to a fluid-filled shell. Under dynamic loads, the interaction of the skull and the underlying brain, cerebrospinal fluid, and other tissue produces the pressure and strain histories that are the basis for many theories meant to describe the genesis of traumatic brain injury. In addition, local bone strains are of interest for predicting skull fracture in blunt trauma. However, the role of skull flexure in the intracranial pressure response to blunt trauma is complex. Since the relative time scales for pressure and flexural wave transmission across the skull are not easily separated, it is difficult to separate out the relative roles of the mechanical components in this system. This study uses a finite element model of the head, which is validated for pressure transmission to the brain, to assess the influence of skull table flexural stiffness on pressure in the brain and on strain within the skull. In a Human Head Finite Element Model, the skull component was modified by attaching shell elements to the inner and outer surfaces of the existing solid elements that modeled the skull. The shell elements were given the properties of bone, and the existing solid elements were decreased so that the overall stiffness along the surface of the skull was unchanged, but the skull table bending stiffness increased by a factor of 2.4. Blunt impact loads were applied to the frontal bone centrally, using LS-Dyna. The intracranial pressure predictions and the strain predictions in the skull were compared for models with and without surface shell elements, showing that the pressures in the mid-anterior and mid-posterior of the brain were very similar, but the strains in the skull under the loads and adjacent to the loads were decreased 15% with stiffer flexural properties. Pressure equilibration to nearly hydrostatic distributions occurred, indicating that the important frequency components for typical impact loading are lower than frequencies based on pressure wave propagation across the skull. This indicates that skull flexure has a local effect on intracranial pressures but that the integrated effect of a dome-like structure under load is a significant part of load transfer in the skull in blunt trauma.

Locoregional and Microvascular Free Tissue Reconstruction of the Lateral Skull Base.

PubMed

Arnaoutakis, Demetri; Kadakia, Sameep; Abraham, Manoj; Lee, Thomas; Ducic, Yadranko

2017-11-01

The goals of reconstruction following any oncologic extirpation are preservation of function, restoration of cosmesis, and avoidance of morbidity. Anatomically, the lateral skull base is complex and conceptually intricate due to its three-dimensional morphology. The temporal bone articulates with five other cranial bones and forms many sutures and foramina through which pass critical neural and vascular structures. Remnant defects following resection of lateral skull base tumors are often not amenable to primary closure. As such, numerous techniques have been described for reconstruction including local rotational muscle flaps, pedicled flaps with skin paddle, or free tissue transfer. In this review, the advantages and disadvantages of each reconstructive method will be discussed as well as their potential complications.

Reconstruction of the anterior skull base after major trauma or extensive tumour resection.

PubMed

König, Stefan Alexander; Ranguis, Sebastian; Gramlich, Veronika; Spetzger, Uwe

2015-01-01

The authors describe their experience with the reconstruction of complex anterior skull base defects after trauma or tumour resection using a "sandwich" technique with pericranial flap, titanium mesh and TachoSil. Description of surgical anatomy, surgical technique, indications, limitations, complications, specific perioperative considerations and specific information to give to the patient about surgery and potential risks. A summary of ten key points is given. After a bifrontal craniotomy and a subfrontal approach, it is possible to achieve a reliable reconstruction of the anterior skull base in a watertight manner by fixing a pericranial flap or a fascia lata graft to the orbital roofs and planum sphenoidale with an individually tailored titanium mesh and closing the frontobasal dura leasion with TachoSil.

The evolution of cranial base and face in Cercopithecoidea and Hominoidea: Modularity and morphological integration.

PubMed

Profico, Antonio; Piras, Paolo; Buzi, Costantino; Di Vincenzo, Fabio; Lattarini, Flavio; Melchionna, Marina; Veneziano, Alessio; Raia, Pasquale; Manzi, Giorgio

2017-12-01

The evolutionary relationship between the base and face of the cranium is a major topic of interest in primatology. Such areas of the skull possibly respond to different selective pressures. Yet, they are often said to be tightly integrated. In this paper, we analyzed shape variability in the cranial base and the facial complex in Cercopithecoidea and Hominoidea. We used a landmark-based approach to single out the effects of size (evolutionary allometry), morphological integration, modularity, and phylogeny (under Brownian motion) on skull shape variability. Our results demonstrate that the cranial base and the facial complex exhibit different responses to different factors, which produces a little degree of morphological integration between them. Facial shape variation appears primarily influenced by body size and sexual dimorphism, whereas the cranial base is mostly influenced by functional factors. The different adaptations affecting the two modules suggest they are best studied as separate and independent units, and that-at least when dealing with Catarrhines-caution must be posed with the notion of strong cranial integration that is commonly invoked for the evolution of their skull shape. © 2017 Wiley Periodicals, Inc.

Craniofacial resection and its role in the management of sinonasal malignancies.

PubMed

Taghi, Ali; Ali, Ahmed; Clarke, Peter

2012-09-01

Sinonasal malignancy is rare, and its presentation is commonly late. There is a wide variety of pathologies with varying natural histories and survival rates. Anatomy of the skull base is extremely complex and tumors are closely related to orbits, frontal lobes and cavernous sinus. Anatomical detail and the late presentation render surgical management a challenging task. A thorough understanding of anatomy and pathology combined with modern neuroimaging and reliable reconstruction within a multidisciplinary team is imperative to carry out skull base surgery effectively. While endoscopic approaches are gaining credibility, clearly, it will be some time before meaningful comparisons with craniofacial resection can be made. Until then, craniofacial resection will remain the gold standard for managing the sinonasal malignancies of the anterior skull base, as it has proved to be safe and effective.

The History and Evolution of Internal Maxillary Artery Bypass.

PubMed

Wang, Long; Cai, Li; Lu, Shuaibin; Qian, Hai; Lawton, Michael T; Shi, Xiang'en

2018-05-01

Internal maxillary artery (IMA) bypass has gained momentum in the last 5 years for the treatment of complex cerebrovascular disorders and skull base tumors. However, some issues regarding this treatment modality have been proposed. As one of the most experienced neurosurgical teams to perform internal maxillary artery bypass in the world (>100 clinical cases), we reviewed the literature in aspects of basic anatomy of maxillary artery with its variations to the lateral pterygoid muscle, initial anastomosis modalities, and subsequent exposure techniques in cadaver studies, preoperative arterial evaluation methods, optimal interposed graft selections, and surgical outcome in the management of complex aneurysms, skull base tumors, and steno-occlusive disorders. Copyright © 2018 Elsevier Inc. All rights reserved.

A Three-Dimensional Statistical Average Skull: Application of Biometric Morphing in Generating Missing Anatomy.

PubMed

Teshima, Tara Lynn; Patel, Vaibhav; Mainprize, James G; Edwards, Glenn; Antonyshyn, Oleh M

2015-07-01

The utilization of three-dimensional modeling technology in craniomaxillofacial surgery has grown exponentially during the last decade. Future development, however, is hindered by the lack of a normative three-dimensional anatomic dataset and a statistical mean three-dimensional virtual model. The purpose of this study is to develop and validate a protocol to generate a statistical three-dimensional virtual model based on a normative dataset of adult skulls. Two hundred adult skull CT images were reviewed. The average three-dimensional skull was computed by processing each CT image in the series using thin-plate spline geometric morphometric protocol. Our statistical average three-dimensional skull was validated by reconstructing patient-specific topography in cranial defects. The experiment was repeated 4 times. In each case, computer-generated cranioplasties were compared directly to the original intact skull. The errors describing the difference between the prediction and the original were calculated. A normative database of 33 adult human skulls was collected. Using 21 anthropometric landmark points, a protocol for three-dimensional skull landmarking and data reduction was developed and a statistical average three-dimensional skull was generated. Our results show the root mean square error (RMSE) for restoration of a known defect using the native best match skull, our statistical average skull, and worst match skull was 0.58, 0.74, and 4.4  mm, respectively. The ability to statistically average craniofacial surface topography will be a valuable instrument for deriving missing anatomy in complex craniofacial defects and deficiencies as well as in evaluating morphologic results of surgery.

The transnasal approach to the skull base. From sinus surgery to skull base surgery

PubMed Central

Wagenmann, Martin; Schipper, Jörg

2012-01-01

The indications for endonasal endoscopic approaches to diseases of the skull base and its adjacent structures have expanded considerably during the last decades. This is not only due to improved technical possibilities such as intraoperative navigation, the development of specialized instruments, and the compilation of anatomical studies from the endoscopic perspective but also related to the accumulating experience with endoscopic procedures of the skull base by multidisciplinary centers. Endoscopic endonasal operations permit new approaches to deeply seated lesions and are characterized by a reduced manipulation of neurovascular structures and brain parenchyma while at the same time providing improved visualization. They reduce the trauma caused by the approach, avoid skin incisions and minimize the surgical morbidity. Transnasal endoscopic procedures for the closure of small and large skull base defects have proven to be reliable and more successful than operations with craniotomies. The development of new local and regional vascularized flaps like the Hadad-flap have contributed to this. These reconstructive techniques are furthermore effectively utilized in tumor surgery in this region. This review delineates the classification of expanded endonasal approaches in detail. They provide access to lesions of the anterior, middle and partly also to the posterior cranial fossa. Successful management of these complex procedures requires a close interdisciplinary collaboration as well as continuous education and training of all team members. PMID:22558058

Automated Surgical Approach Planning for Complex Skull Base Targets: Development and Validation of a Cost Function and Semantic At-las.

PubMed

Aghdasi, Nava; Whipple, Mark; Humphreys, Ian M; Moe, Kris S; Hannaford, Blake; Bly, Randall A

2018-06-01

Successful multidisciplinary treatment of skull base pathology requires precise preoperative planning. Current surgical approach (pathway) selection for these complex procedures depends on an individual surgeon's experiences and background training. Because of anatomical variation in both normal tissue and pathology (eg, tumor), a successful surgical pathway used on one patient is not necessarily the best approach on another patient. The question is how to define and obtain optimized patient-specific surgical approach pathways? In this article, we demonstrate that the surgeon's knowledge and decision making in preoperative planning can be modeled by a multiobjective cost function in a retrospective analysis of actual complex skull base cases. Two different approaches- weighted-sum approach and Pareto optimality-were used with a defined cost function to derive optimized surgical pathways based on preoperative computed tomography (CT) scans and manually designated pathology. With the first method, surgeon's preferences were input as a set of weights for each objective before the search. In the second approach, the surgeon's preferences were used to select a surgical pathway from the computed Pareto optimal set. Using preoperative CT and magnetic resonance imaging, the patient-specific surgical pathways derived by these methods were similar (85% agreement) to the actual approaches performed on patients. In one case where the actual surgical approach was different, revision surgery was required and was performed utilizing the computationally derived approach pathway.

Reconstruction of posterior neck and skull with vertical trapezius musculocutaneous flap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathes, S.J.; Stevenson, T.R.

1988-10-01

The vertical trapezius musculocutaneous flap has been successfully utilized for reconstruction in 13 patients with complex posterior skull and neck defects. This flap based on its vascular pedicle, the descending branch of the transverse cervical artery, provides well-vascularized tissue for coverage of defects related to chronic osteomyelitis, tumor extirpation, osteoradionecrosis, and dehisced cervical laminectomy wounds. Emphasis on flap design, including the location of the skin island, allows adequate wound coverage, direct donor site closure, and muscle function preservation. With its large size and wide arc of rotation, the vertical trapezius musculocutaneous flap provides reliable coverage for posterior trunk, cervical, andmore » skull defects.« less

Skull base tumors: a comprehensive review of transfacial swing osteotomy approaches.

PubMed

Moreira-Gonzalez, Andrea; Pieper, Daniel R; Cambra, Jorge Balaguer; Simman, Richard; Jackson, Ian T

2005-03-01

Numerous techniques have been proposed for the resection of skull base tumors, each one unique with regard to the region exposed and degree of technical complexity. This study describes the use of transfacial swing osteotomies in accessing lesions located at various levels of the cranial base. Eight patients who underwent transfacial swings for exposure and resection of cranial base lesions between 1996 and 2002 were studied. The mandible was the choice when wide exposure of nasopharyngeal and midline skull base tumors was necessary, especially when they involved the infratemporal fossa. The midfacial swing osteotomy was an option when access to the entire clivus was necessary. An orbital swing approach was used to access large orbital tumors lying inferior to the optic nerve and posterior to the globe, a region that is often difficult to visualize. Gross total tumor excision was possible in all patients. Six patients achieved disease control and two had recurrences. The complications of cerebrospinal fluid leak, infection, hematoma, or cranial nerve damage did not occur. After surgery, some patients experienced temporary symptoms caused by local swelling. The aesthetic result was considered good. Transfacial swing osteotomies provide a wide exposure to tumors that occur in the central skull base area. Excellent knowledge of the detailed anatomy of this region is paramount to the success of this surgery. The team concept is essential; it is built around the craniofacial surgeon and an experienced skull base neurosurgeon.

Atlas and feature based 3D pathway visualization enhancement for skull base pre-operative fast planning from head CT

NASA Astrophysics Data System (ADS)

Aghdasi, Nava; Li, Yangming; Berens, Angelique; Moe, Kris S.; Bly, Randall A.; Hannaford, Blake

2015-03-01

Minimally invasive neuroendoscopic surgery provides an alternative to open craniotomy for many skull base lesions. These techniques provides a great benefit to the patient through shorter ICU stays, decreased post-operative pain and quicker return to baseline function. However, density of critical neurovascular structures at the skull base makes planning for these procedures highly complex. Furthermore, additional surgical portals are often used to improve visualization and instrument access, which adds to the complexity of pre-operative planning. Surgical approach planning is currently limited and typically involves review of 2D axial, coronal, and sagittal CT and MRI images. In addition, skull base surgeons manually change the visualization effect to review all possible approaches to the target lesion and achieve an optimal surgical plan. This cumbersome process relies heavily on surgeon experience and it does not allow for 3D visualization. In this paper, we describe a rapid pre-operative planning system for skull base surgery using the following two novel concepts: importance-based highlight and mobile portal. With this innovation, critical areas in the 3D CT model are highlighted based on segmentation results. Mobile portals allow surgeons to review multiple potential entry portals in real-time with improved visualization of critical structures located inside the pathway. To achieve this we used the following methods: (1) novel bone-only atlases were manually generated, (2) orbits and the center of the skull serve as features to quickly pre-align the patient's scan with the atlas, (3) deformable registration technique was used for fine alignment, (4) surgical importance was assigned to each voxel according to a surgical dictionary, and (5) pre-defined transfer function was applied to the processed data to highlight important structures. The proposed idea was fully implemented as independent planning software and additional data are used for verification and validation. The experimental results show: (1) the proposed methods provided greatly improved planning efficiency while optimal surgical plans were successfully achieved, (2) the proposed methods successfully highlighted important structures and facilitated planning, (3) the proposed methods require shorter processing time than classical segmentation algorithms, and (4) these methods can be used to improve surgical safety for surgical robots.

Automatic Brain Portion Segmentation From Magnetic Resonance Images of Head Scans Using Gray Scale Transformation and Morphological Operations.

PubMed

Somasundaram, Karuppanagounder; Ezhilarasan, Kamalanathan

2015-01-01

To develop an automatic skull stripping method for magnetic resonance imaging (MRI) of human head scans. The proposed method is based on gray scale transformation and morphological operations. The proposed method has been tested with 20 volumes of normal T1-weighted images taken from Internet Brain Segmentation Repository. Experimental results show that the proposed method gives better results than the popular skull stripping methods Brain Extraction Tool and Brain Surface Extractor. The average value of Jaccard and Dice coefficients are 0.93 and 0.962 respectively. In this article, we have proposed a novel skull stripping method using intensity transformation and morphological operations. This is a low computational complexity method but gives competitive or better results than that of the popular skull stripping methods Brain Surface Extractor and Brain Extraction Tool.

Role of targeted magnetic resonance imaging sequences in the surgical management of anterior skull base pathology.

PubMed

Chawla, S; Bowman, J; Gandhi, M; Panizza, B

2017-01-01

The skull base is a highly complex anatomical region that provides passage for important nerves and vessels as they course into and out of the cranial cavity. Key to the management of pathology in this region is a thorough understanding of the anatomy, with its variations, and the relationship of various neurovascular structures to the pathology in question. Targeted high-resolution magnetic resonance imaging on high field strength magnets can enable the skull base surgeon to understand this intricate relationship and deal with the pathology from a position of relative advantage. With the help of case studies, this paper illustrates the application of specialised magnetic resonance techniques to study pathology of the orbital apex in particular. The fine anatomical detail provided gives surgeons the ability to design an endonasal endoscopic procedure appropriate to the anatomy of the pathology.

Proof of Concept Study for the Design, Manufacturing, and Testing of a Patient-Specific Shape Memory Device for Treatment of Unicoronal Craniosynostosis.

PubMed

Borghi, Alessandro; Rodgers, Will; Schievano, Silvia; Ponniah, Allan; Jeelani, Owase; Dunaway, David

2018-01-01

Treatment of unicoronal craniosynostosis is a surgically challenging problem, due to the involvement of coronal suture and cranial base, with complex asymmetries of the calvarium and orbit. Several techniques for correction have been described, including surgical bony remodeling, early strip craniotomy with orthotic helmet remodeling and distraction. Current distraction devices provide unidirectional forces and have had very limited success. Nitinol is a shape memory alloy that can be programmed to the shape of a patient-specific anatomy by means of thermal treatment.In this work, a methodology to produce a nitinol patient-specific distractor is presented: computer tomography images of a 16-month-old patient with unicoronal craniosynostosis were processed to create a 3-dimensional model of his skull and define the ideal shape postsurgery. A mesh was produced from a nitinol sheet, formed to the ideal skull shape and heat treated to be malleable at room temperature. The mesh was afterward deformed to be attached to a rapid prototyped plastic skull, replica of the patient initial anatomy. The mesh/skull construct was placed in hot water to activate the mesh shape memory property: the deformed plastic skull was computed tomography scanned for comparison of its shape with the initial anatomy and with the desired shape, showing that the nitinol mesh had been able to distract the plastic skull to a shape close to the desired one.The shape-memory properties of nitinol allow for the design and production of patient-specific devices able to deliver complex, preprogrammable shape changes.

Comparison of analytical and numerical approaches for CT-based aberration correction in transcranial passive acoustic imaging

NASA Astrophysics Data System (ADS)

Jones, Ryan M.; Hynynen, Kullervo

2016-01-01

Computed tomography (CT)-based aberration corrections are employed in transcranial ultrasound both for therapy and imaging. In this study, analytical and numerical approaches for calculating aberration corrections based on CT data were compared, with a particular focus on their application to transcranial passive imaging. Two models were investigated: a three-dimensional full-wave numerical model (Connor and Hynynen 2004 IEEE Trans. Biomed. Eng. 51 1693-706) based on the Westervelt equation, and an analytical method (Clement and Hynynen 2002 Ultrasound Med. Biol. 28 617-24) similar to that currently employed by commercial brain therapy systems. Trans-skull time delay corrections calculated from each model were applied to data acquired by a sparse hemispherical (30 cm diameter) receiver array (128 piezoceramic discs: 2.5 mm diameter, 612 kHz center frequency) passively listening through ex vivo human skullcaps (n  =  4) to emissions from a narrow-band, fixed source emitter (1 mm diameter, 516 kHz center frequency). Measurements were taken at various locations within the cranial cavity by moving the source around the field using a three-axis positioning system. Images generated through passive beamforming using CT-based skull corrections were compared with those obtained through an invasive source-based approach, as well as images formed without skull corrections, using the main lobe volume, positional shift, peak sidelobe ratio, and image signal-to-noise ratio as metrics for image quality. For each CT-based model, corrections achieved by allowing for heterogeneous skull acoustical parameters in simulation outperformed the corresponding case where homogeneous parameters were assumed. Of the CT-based methods investigated, the full-wave model provided the best imaging results at the cost of computational complexity. These results highlight the importance of accurately modeling trans-skull propagation when calculating CT-based aberration corrections. Although presented in an imaging context, our results may also be applicable to the problem of transmit focusing through the skull.

The combined endonasal and transoral approach for the management of skull base and nasopharyngeal pathology: a case series.

PubMed

Sreenath, Satyan B; Rawal, Rounak B; Zanation, Adam M

2014-01-01

The posterior skull base and the nasopharynx have historically represented technically difficult regions to approach surgically given their central anatomical locations. Through continued improvements in endoscopic instrumentation and technology, the expanded endonasal approach (EEA) has introduced a new array of surgical options in the management of pathology involving these anatomically complex areas. Similarly, the transoral robotic surgical (TORS) approach was introduced as a minimally invasive surgical option to approach tongue base, nasopharyngeal, parapharyngeal, and laryngeal lesions. Although both the EEA and the TORS approach have been extensively described as viable surgical options in managing nasopharyngeal and centrally located head and neck pathology, both endonasal and transoral techniques have inherent limitations. Given these limitations, several institutions have published feasibility studies with the combined EEA and TORS approaches for a variety of skull base and nasopharyngeal pathologies. In this article, the authors present their clinical experience with the combined endonasal and transoral approach through a case series presentation, and discuss advantages and limitations of this approach for surgical management of the middle and posterior skull base and nasopharynx. In addition, a presentation is included of a unique, simultaneous endonasal and transoral dissection of the nasopharynx through an innovative intraoperative setup.

Complex single step skull reconstruction in Gorham's disease - a technical report and review of the literature.

PubMed

Ohla, Victoria; Bayoumi, Ahmed B; Hefty, Markus; Anderson, Matthew; Kasper, Ekkehard M

2015-03-11

Gorham's disease is a rare osteolytic disorder characterized by progressive resorption of bone and replacement of osseous matrix by a proliferative non-neoplastic vascular or lymphatic tissue. A standardized treatment protocol has not yet been defined due to the unpredictable natural history of the disease and variable clinical presentations. No single treatment has proven to be superior in arresting the course of the disease. Trials have included surgery, radiation and medical therapies using drugs such as calcium salts, vitamin D supplements and hormones. We report on our advantageous experience in the management of this osteolyic disorder in a case when it affected only the skull vault. A brief review of pertinent literature about Gorham's disease with skull involvement is provided. A 25-year-old Caucasian male presented with a skull depression over the left fronto-temporal region. He noticed progressive enlargement of the skull defect associated with local pain and mild headache. Physical examination revealed a tender palpable depression of the fronto-temporal convexity. Conventional X-ray of the skull showed widespread loss of bone substance. Subsequent CT scans showed features of patchy erosions indicative of an underlying osteolysis. MRI also revealed marginal enhancement at the site of the defect. The patient was in need of a pathological diagnosis as well as complex reconstruction of the afflicted area. A density graded CT scan was done to determine the variable degrees of osteolysis and a custom made allograft was designed for cranioplasty preoperatively to allow for a single step excisional craniectomy with synchronous skull repair. Gorham's disease was diagnosed based on histopathological examination. No neurological deficit or wound complications were reported postoperatively. Over a two-year follow up period, the patient had no evidence of local recurrence or other systemic involvement. A single step excisional craniectomy and cranioplasty can be an effective treatment for patients with Gorham's disease affecting the skull vault only. Preoperative planning by a density graded CT aids to design a synthetic bone flap and is beneficial in skull reconstruction. Systemic involvement is variable in this patient's population.

Derivation of the mammalian skull vault

PubMed Central

MORRISS-KAY, GILLIAN M.

2001-01-01

This review describes the evolutionary history of the mammalian skull vault as a basis for understanding its complex structure. Current information on the developmental tissue origins of the skull vault bones (mesoderm and neural crest) is assessed for mammals and other tetrapods. This information is discussed in the context of evolutionary changes in the proportions of the skull vault bones at the sarcopterygian-tetrapod transition. The dual tissue origin of the skull vault is considered in relation to the molecular mechanisms underlying osteogenic cell proliferation and differentiation in the sutural growth centres and in the proportionate contributions of different sutures to skull growth. PMID:11523816

Use of Tranexamic Acid Is Associated with Reduced Blood Product Transfusion in Complex Skull Base Neurosurgical Procedures: A Retrospective Cohort Study.

PubMed

Mebel, Dmitry; Akagami, Ryojo; Flexman, Alana M

2016-02-01

Compared with other procedures, complex skull base neurosurgery has the potential for increased intraoperative blood loss yet coagulation near eloquent cranial structures should be minimized. The safety and efficacy of the antifibrinolytic, tranexamic acid in elective neurosurgical procedures is not known. Our primary objective was to determine the relationship between the use of tranexamic acid and transfusion at our institution. Our secondary objective was to determine the incidence of adverse events associated with the use of tranexamic acid. In this retrospective cohort study, we included all patients who underwent complex skull base neurosurgical procedures at our institution between 2001 and 2013. Tranexamic acid was introduced during these procedures in 2006. Patient and surgical variables, transfusion data, and adverse events in the perioperative period were abstracted from the medical record. The rates of transfusion and adverse events were compared between patients who did and did not receive tranexamic acid. Multivariate regression was used to identify independent predictors of perioperative transfusion. We compared 245 patients who received tranexamic acid with 274 patients who did not receive the drug during the study period. The 2 groups were similar, with the exception that patients who received tranexamic acid had larger tumors (mean, 3.5 vs 2.9 cm; P < 0.001) and longer procedures (mean, 7.2 vs 6.2 hours, P < 0.001). The rate of perioperative transfusion in patients who received tranexamic acid was lower (7% vs 13%, P = 0.04). After adjusting for preoperative hemoglobin, tumor diameter, and surgical procedure category, the use of tranexamic acid was independently predictive of perioperative transfusion (adjusted odds ratio, 0.32; 95% confidence interval, 0.15-0.65, P = 0.002). The rates of thromboembolic events and seizure were similar between the 2 groups. Our results demonstrate that tranexamic acid use is associated with reduced transfusion rates in our study population, with no apparent increase in seizure or thrombotic complications. Our data support the need for further randomized clinical trials to evaluate the efficacy and safety of tranexamic acid on perioperative blood loss during complex skull base neurosurgery.

The Role of Skull Modeling in EEG Source Imaging for Patients with Refractory Temporal Lobe Epilepsy.

PubMed

Montes-Restrepo, Victoria; Carrette, Evelien; Strobbe, Gregor; Gadeyne, Stefanie; Vandenberghe, Stefaan; Boon, Paul; Vonck, Kristl; Mierlo, Pieter van

2016-07-01

We investigated the influence of different skull modeling approaches on EEG source imaging (ESI), using data of six patients with refractory temporal lobe epilepsy who later underwent successful epilepsy surgery. Four realistic head models with different skull compartments, based on finite difference methods, were constructed for each patient: (i) Three models had skulls with compact and spongy bone compartments as well as air-filled cavities, segmented from either computed tomography (CT), magnetic resonance imaging (MRI) or a CT-template and (ii) one model included a MRI-based skull with a single compact bone compartment. In all patients we performed ESI of single and averaged spikes marked in the clinical 27-channel EEG by the epileptologist. To analyze at which time point the dipole estimations were closer to the resected zone, ESI was performed at two time instants: the half-rising phase and peak of the spike. The estimated sources for each model were validated against the resected area, as indicated by the postoperative MRI. Our results showed that single spike analysis was highly influenced by the signal-to-noise ratio (SNR), yielding estimations with smaller distances to the resected volume at the peak of the spike. Although averaging reduced the SNR effects, it did not always result in dipole estimations lying closer to the resection. The proposed skull modeling approaches did not lead to significant differences in the localization of the irritative zone from clinical EEG data with low spatial sampling density. Furthermore, we showed that a simple skull model (MRI-based) resulted in similar accuracy in dipole estimation compared to more complex head models (based on CT- or CT-template). Therefore, all the considered head models can be used in the presurgical evaluation of patients with temporal lobe epilepsy to localize the irritative zone from low-density clinical EEG recordings.

The accuracy of an electromagnetic navigation system in lateral skull base approaches.

PubMed

Komune, Noritaka; Matsushima, Ken; Matsuo, Satoshi; Safavi-Abbasi, Sam; Matsumoto, Nozomu; Rhoton, Albert L

2017-02-01

Image-guided optical tracking systems are being used with increased frequency in lateral skull base surgery. Recently, electromagnetic tracking systems have become available for use in this region. However, the clinical accuracy of the electromagnetic tracking system has not been examined in lateral skull base surgery. This study evaluates the accuracy of electromagnetic navigation in lateral skull base surgery. Cadaveric and radiographic study. Twenty cadaveric temporal bones were dissected in a surgical setting under a commercially available, electromagnetic surgical navigation system. The target registration error (TRE) was measured at 28 surgical landmarks during and after performing the standard translabyrinthine and middle cranial fossa surgical approaches to the internal acoustic canal. In addition, three demonstrative procedures that necessitate navigation with high accuracy were performed; that is, canalostomy of the superior semicircular canal from the middle cranial fossa, 1 cochleostomy from the middle cranial fossa, 2 and infralabyrinthine approach to the petrous apex. 3 RESULTS: Eleven of 17 (65%) of the targets in the translabyrinthine approach and five of 11 (45%) of the targets in the middle fossa approach could be identified in the navigation system with TRE of less than 0.5 mm. Three accuracy-dependent procedures were completed without anatomical injury of important anatomical structures. The electromagnetic navigation system had sufficient accuracy to be used in the surgical setting. It was possible to perform complex procedures in the lateral skull base under the guidance of the electromagnetically tracked navigation system. N/A. Laryngoscope, 2016 127:450-459, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Open Approaches to the Anterior Skull Base in Children: Review of the Literature.

PubMed

Wasserzug, Oshri; DeRowe, Ari; Ringel, Barak; Fishman, Gadi; Fliss, Dan M

2018-02-01

Introduction  Skull base lesions in children and adolescents are rare, and comprise only 5.6% of all skull base surgery. Anterior skull base lesions dominate, averaging slightly more than 50% of the cases. Until recently, surgery of the anterior skull base was dominated by open procedures and endoscopic skull base surgery was reserved for benign pathologies. Endoscopic skull base surgery is gradually gaining popularity. In spite of that, open skull base surgery is still considered the "gold standard" for the treatment of anterior skull base lesions, and it is the preferred approach in selected cases. Objective  This article reviews current concepts and open approaches to the anterior skull base in children in the era of endoscopic surgery. Materials and Methods  Comprehensive literature review. Results  Extensive intracranial-intradural invasion, extensive orbital invasion, encasement of the optic nerve or the internal carotid artery, lateral supraorbital dural involvement and involvement of the anterior table of the frontal sinus or lateral portion of the frontal sinus precludes endoscopic surgery, and mandates open skull base surgery. The open approaches which are used most frequently for surgical resection of anterior skull base tumors are the transfacial/transmaxillary, subcranial, and subfrontal approaches. Reconstruction of anterior skull base defects is discussed in a separate article in this supplement. Discussion  Although endoscopic skull base surgery in children is gaining popularity in developed countries, in many cases open surgery is still required. In addition, in developing countries, which accounts for more than 80% of the world's population, limited access to expensive equipment precludes the use of endoscopic surgery. Several open surgical approaches are still employed to resect anterior skull base lesions in the pediatric population. With this large armamentarium of surgical approaches, tailoring the most suitable approach to a specific lesion in regard to its nature, location, and extent is of utmost importance.

High Resolution Three-Dimensional MR Imaging of the Skull Base: Compartments, Boundaries, and Critical Structures.

PubMed

Blitz, Ari Meir; Aygun, Nafi; Herzka, Daniel A; Ishii, Masaru; Gallia, Gary L

2017-01-01

High-resolution 3D MRI of the skull base allows for a more detailed and accurate assessment of normal anatomic structures as well as the location and extent of skull base pathologies than has previously been possible. This article describes the techniques employed for high-resolution skull base MRI including pre- and post-contrast constructive interference in the steady state (CISS) imaging and their utility for evaluation of the many small structures of the skull base, focusing on those regions and concepts most pertinent to localization of cranial nerve palsies and in providing pre-operative guidance and post-operative assessment. The concept of skull base compartments as a means of conceptualizing the various layers of the skull base and their importance in assessment of masses of the skull base is discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

A regional method for craniofacial reconstruction based on coordinate adjustments and a new fusion strategy.

PubMed

Deng, Qingqiong; Zhou, Mingquan; Wu, Zhongke; Shui, Wuyang; Ji, Yuan; Wang, Xingce; Liu, Ching Yiu Jessica; Huang, Youliang; Jiang, Haiyan

2016-02-01

Craniofacial reconstruction recreates a facial outlook from the cranium based on the relationship between the face and the skull to assist identification. But craniofacial structures are very complex, and this relationship is not the same in different craniofacial regions. Several regional methods have recently been proposed, these methods segmented the face and skull into regions, and the relationship of each region is then learned independently, after that, facial regions for a given skull are estimated and finally glued together to generate a face. Most of these regional methods use vertex coordinates to represent the regions, and they define a uniform coordinate system for all of the regions. Consequently, the inconsistence in the positions of regions between different individuals is not eliminated before learning the relationships between the face and skull regions, and this reduces the accuracy of the craniofacial reconstruction. In order to solve this problem, an improved regional method is proposed in this paper involving two types of coordinate adjustments. One is the global coordinate adjustment performed on the skulls and faces with the purpose to eliminate the inconsistence of position and pose of the heads; the other is the local coordinate adjustment performed on the skull and face regions with the purpose to eliminate the inconsistence of position of these regions. After these two coordinate adjustments, partial least squares regression (PLSR) is used to estimate the relationship between the face region and the skull region. In order to obtain a more accurate reconstruction, a new fusion strategy is also proposed in the paper to maintain the reconstructed feature regions when gluing the facial regions together. This is based on the observation that the feature regions usually have less reconstruction errors compared to rest of the face. The results demonstrate that the coordinate adjustments and the new fusion strategy can significantly improve the craniofacial reconstructions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Design and Characterization of an Acoustically and Structurally Matched 3-D-Printed Model for Transcranial Ultrasound Imaging.

PubMed

Bai, Chen; Ji, Meiling; Bouakaz, Ayache; Zong, Yujin; Wan, Mingxi

2018-05-01

For investigating human transcranial ultrasound imaging (TUI) through the temporal bone, an intact human skull is needed. Since it is complex and expensive to obtain one, it requires that experiments are performed without excision or abrasion of the skull. Besides, to mimic blood circulation for the vessel target, cellulose tubes generally fit the vessel simulation with straight linear features. These issues, which limit experimental studies, can be overcome by designing a 3-D-printed skull model with acoustic and dimensional properties that match a real skull and a vessel model with curve and bifurcation. First, the optimal printing material which matched a real skull in terms of the acoustic attenuation coefficient and sound propagation velocity was identified at 2-MHz frequency, i.e., 7.06 dB/mm and 2168.71 m/s for the skull while 6.98 dB/mm and 2114.72 m/s for the printed material, respectively. After modeling, the average thickness of the temporal bone in the printed skull was about 1.8 mm, while it was to 1.7 mm in the real skull. Then, a vascular phantom was designed with 3-D-printed vessels of low acoustic attenuation (0.6 dB/mm). It was covered with a porcine brain tissue contained within a transparent polyacrylamide gel. After characterizing the acoustic consistency, based on the designed skull model and vascular phantom, vessels with inner diameters of 1 and 0.7 mm were distinguished by resolution enhanced imaging with low frequency. Measurements and imaging results proved that the model and phantom are authentic and viable alternatives, and will be of interest for TUI, high intensity focused ultrasound, or other therapy studies.

Craniosynostosis

MedlinePlus

... fibrous joints between the bones of your baby's skull (cranial sutures) close prematurely (fuse), before your baby's ... than one of the sutures in your baby's skull (complex craniosynostosis). In rare cases, craniosynostosis is caused ...

Application of computer-aided three-dimensional skull model with rapid prototyping technique in repair of zygomatico-orbito-maxillary complex fracture.

PubMed

Li, Wei Zhong; Zhang, Mei Chao; Li, Shao Ping; Zhang, Lei Tao; Huang, Yu

2009-06-01

With the advent of CAD/CAM and rapid prototyping (RP), a technical revolution in oral and maxillofacial trauma was promoted to benefit treatment, repair of maxillofacial fractures and reconstruction of maxillofacial defects. For a patient with zygomatico-facial collapse deformity resulting from a zygomatico-orbito-maxillary complex (ZOMC) fracture, CT scan data were processed by using Mimics 10.0 for three-dimensional (3D) reconstruction. The reduction design was aided by 3D virtual imaging and the 3D skull model was reproduced using the RP technique. In line with the design by Mimics, presurgery was performed on the 3D skull model and the semi-coronal incision was taken for reduction of ZOMC fracture, based on the outcome from the presurgery. Postoperative CT and images revealed significantly modified zygomatic collapse and zygomatic arch rise and well-modified facial symmetry. The CAD/CAM and RP technique is a relatively useful tool that can assist surgeons with reconstruction of the maxillofacial skeleton, especially in repairs of ZOMC fracture.

Imaging of the Posterior Skull Base.

PubMed

Job, Joici; Branstetter, Barton F

2017-01-01

The posterior skull base can be involved by a variety of pathologic processes. They can be broadly classified as: traumatic, neoplastic, vascular, and inflammatory. Pathology in the posterior skull base usually involves the lower cranial nerves, either as a source of pathology or a secondary source of symptoms. This review will categorize pathology arising in the posterior skull base and describe how it affects the skull base itself and surrounding structures. Copyright © 2016 Elsevier Inc. All rights reserved.

A case of bilateral lower cranial nerve palsies after base of skull trauma with complex management issues: case report and review of the literature.

PubMed

Lehn, Alexander Christoph; Lettieri, Jennie; Grimley, Rohan

2012-05-01

Fractures of the skull base can cause lower cranial nerve palsies because of involvement of the nerves as they traverse the skull. A variety of syndromes have been described, often involving multiple nerves. These are most commonly unilateral, and only a handful of cases of bilateral cranial nerve involvement have been reported. We describe a 64-year-old man with occipital condylar fracture complicated by bilateral palsies of IX and X nerves associated with dramatic physiological derangement causing severe management challenges. Apart from debilitating postural hypotension, he developed dysphagia, severe gastrointestinal dysmotility, issues with airway protection as well as airway obstruction, increased oropharyngeal secretions and variable respiratory control. This is the first report of a patient with traumatic bilateral cranial nerve IX and X nerve palsies. This detailed report and the summary of all 6 previous case reports of traumatic bilateral lower cranial nerve palsies illustrate clinical features, treatment strategies, and outcomes of these rare events.

Skull defect reconstruction based on a new hybrid level set.

PubMed

Zhang, Ziqun; Zhang, Ran; Song, Zhijian

2014-01-01

Skull defect reconstruction is an important aspect of surgical repair. Historically, a skull defect prosthesis was created by the mirroring technique, surface fitting, or formed templates. These methods are not based on the anatomy of the individual patient's skull, and therefore, the prosthesis cannot precisely correct the defect. This study presented a new hybrid level set model, taking into account both the global optimization region information and the local accuracy edge information, while avoiding re-initialization during the evolution of the level set function. Based on the new method, a skull defect was reconstructed, and the skull prosthesis was produced by rapid prototyping technology. This resulted in a skull defect prosthesis that well matched the skull defect with excellent individual adaptation.

Demonstration of skull bones mobility using optical methods: practical importance in medicine

NASA Astrophysics Data System (ADS)

Zakharov, Alexander V.; Okushko, Vladimir R.; Vturin, Sergey A.; Moseychuk, Vladimir V.; Petrov, Aleksey A.; Suetenkov, Dmitry E.

2014-01-01

Unprompted skull bones mobility not related to breathing, heart beating and other physiological reactions, using installation of original construction with control of physiological parameters by biofeedback hardware-software complex BOS-lab and BOS-pulse appliance (COMSIB, Novosibirsk, Russia) has been confirmed. Teeth eruption occurs through odontiasis canals, emerging from the funiculus. The main driving force for promoting a tooth into odontiasis canal during eruption is the unprompted skull bones mobility. A simple optical installation was made for the visualization of skull bones mobility during the investigation of the median palatine and incisors sutures. Early detection of failures of unprompted skull bones mobility and its normalization can lead to prevention of impact teeth, malocclusion, extrudocclusion and other anomalies and deformations of teeth, teeth rows, TMJ and skull. The skull bones mobility should be considered during the early preventive treatment and therapy of the consequences of injuries and malfunction of the maxillofacial area.

Does shape co-variation between the skull and the mandible have functional consequences? A 3D approach for a 3D problem

PubMed Central

Cornette, Raphaël; Baylac, Michel; Souter, Thibaud; Herrel, Anthony

2013-01-01

Morpho-functional patterns are important drivers of phenotypic diversity given their importance in a fitness-related context. Although modularity of the mandible and skull has been studied extensively in mammals, few studies have explored shape co-variation between these two structures. Despite being developmentally independent, the skull and mandible form a functionally integrated unit. In the present paper we use 3D surface geometric morphometric methods allowing us to explore the form of both skull and mandible in its 3D complexity using the greater white-toothed shrew as a model. This approach allows an accurate 3D description of zones devoid of anatomical landmarks that are functionally important. Two-block partial least-squares approaches were used to describe the co-variation of form between skull and mandible. Moreover, a 3D biomechanical model was used to explore the functional consequences of the observed patterns of co-variation. Our results show the efficiency of the method in investigations of complex morpho-functional patterns. Indeed, the description of shape co-variation between the skull and the mandible highlighted the location and the intensity of their functional relationships through the jaw adductor muscles linking these two structures. Our results also demonstrated that shape co-variation in form between the skull and mandible has direct functional consequences on the recruitment of muscles during biting. PMID:23964811

Tracing the developmental origin of a lizard skull: Chondrocranial architecture, heterochrony, and variation in lacertids.

PubMed

Yaryhin, Oleksandr; Werneburg, Ingmar

2018-06-08

The sand lizard, Lacerta agilis, is a classical model species in herpetology. Its adult skull anatomy and its embryonic development are well known. The description of its fully formed primordial skull by Ernst Gaupp, in 1900, was a key publication in vertebrate morphology and influenced many comparative embryologists. Based on recent methodological considerations, we restudied the early cranial development of this species starting as early as the formation of mesenchymal condensations up to the fully formed chondrocranium. We traced the formation of the complex chondrocranial architecture in detail, clarified specific homologies for the first time, and uncovered major differences to old textbook descriptions. Comparison with other lacertid lizards revealed a very similar genesis of the primordial skull. However, we detected shifts in the developmental timing of particular cartilaginous elements, mainly in the nasal region, which may correlate to specific ecological adaptation in the adults. Late timing of nasal elements might be an important innovation for the successful wide range distribution of the well-known sand lizard. © 2018 Wiley Periodicals, Inc.

The 360 photography: a new anatomical insight of the sphenoid bone. Interest for anatomy teaching and skull base surgery.

PubMed

Jacquesson, Timothée; Mertens, Patrick; Berhouma, Moncef; Jouanneau, Emmanuel; Simon, Emile

2017-01-01

Skull base architecture is tough to understand because of its 3D complex shape and its numerous foramen, reliefs or joints. It is especially true for the sphenoid bone whom central location hinged with most of skull base components is unique. Recently, technological progress has led to develop new pedagogical tools. This way, we bought a new real-time three-dimensional insight of the sphenoid bone that could be useful for the teacher, the student and the surgeon. High-definition photography was taken all around an isolated dry skull base bone prepared with Beauchêne's technique. Pictures were then computed to provide an overview with rotation and magnification on demand. From anterior, posterior, lateral or oblique views and from in out looks, anatomical landmarks and subtleties were described step by step. Thus, the sella turcica, the optic canal, the superior orbital fissure, the sphenoid sinus, the vidian canal, pterygoid plates and all foramen were clearly placed relative to the others at each face of the sphenoid bone. In addition to be the first report of the 360 Photography tool, perspectives are promising as the development of a real-time interactive tridimensional space featuring the sphenoid bone. It allows to turn around the sphenoid bone and to better understand its own special shape, numerous foramen, neurovascular contents and anatomical relationships. This new technological tool may further apply for surgical planning and mostly for strengthening a basic anatomical knowledge firstly introduced.

The olfactory fascia: an evo-devo concept of the fibrocartilaginous nose.

PubMed

Jankowski, Roger; Rumeau, Cécile; de Saint Hilaire, Théophile; Tonnelet, Romain; Nguyen, Duc Trung; Gallet, Patrice; Perez, Manuela

2016-12-01

Evo-devo is the science that studies the link between evolution of species and embryological development. This concept helps to understand the complex anatomy of the human nose. The evo-devo theory suggests the persistence in the adult of an anatomical entity, the olfactory fascia, that unites the cartilages of the nose to the olfactory mucosa. We dissected two fresh specimens. After resecting the superficial tissues of the nose, dissection was focused on the disarticulation of the fibrocartilaginous noses from the facial and skull base skeleton. Dissection shows two fibrocartilaginous sacs that were invaginated side-by-side in the midface and attached to the anterior skull base. These membranous sacs were separated in the midline by the perpendicular plate of the ethmoid. Their walls contained the alar cartilages and the lateral expansions of the septolateral cartilage, which we had to separate from the septal cartilage. The olfactory mucosa was located inside their cranial ends. The olfactory fascia is a continuous membrane uniting the nasal cartilages to the olfactory mucosa. Its origin can be found in the invagination and differentiation processes of the olfactory placodes. The fibrous portions of the olfactory fascia may be described as ligaments that unit the different components of the olfactory fascia one to the other and the fibrocartilaginous nose to the facial and skull base skeleton. The basicranial ligaments, fixing the fibrocartilaginous nose to the skull base, represent key elements in the concept of septorhinoplasty by disarticulation.

Construction of a three-dimensional interactive model of the skull base and cranial nerves.

PubMed

Kakizawa, Yukinari; Hongo, Kazuhiro; Rhoton, Albert L

2007-05-01

The goal was to develop an interactive three-dimensional (3-D) computerized anatomic model of the skull base for teaching microneurosurgical anatomy and for operative planning. The 3-D model was constructed using commercially available software (Maya 6.0 Unlimited; Alias Systems Corp., Delaware, MD), a personal computer, four cranial specimens, and six dry bones. Photographs from at least two angles of the superior and lateral views were imported to the 3-D software. Many photographs were needed to produce the model in anatomically complex areas. Careful dissection was needed to expose important structures in the two views. Landmarks, including foramen, bone, and dura mater, were used as reference points. The 3-D model of the skull base and related structures was constructed using more than 300,000 remodeled polygons. The model can be viewed from any angle. It can be rotated 360 degrees in any plane using any structure as the focal point of rotation. The model can be reduced or enlarged using the zoom function. Variable transparencies could be assigned to any structures so that the structures at any level can be seen. Anatomic labels can be attached to the structures in the 3-D model for educational purposes. This computer-generated 3-D model can be observed and studied repeatedly without the time limitations and stresses imposed by surgery. This model may offer the potential to create interactive surgical exercises useful in evaluating multiple surgical routes to specific target areas in the skull base.

Hand in glove: brain and skull in development and dysmorphogenesis

PubMed Central

Flaherty, Kevin

2013-01-01

The brain originates relatively early in development from differentiated ectoderm that forms a hollow tube and takes on an exceedingly complex shape with development. The skull is made up of individual bony elements that form from neural crest- and mesoderm-derived mesenchyme that unite to provide support and protection for soft tissues and spaces of the head. The meninges provide a protective and permeable membrane between brain and skull. Across evolutionary and developmental time, dynamic changes in brain and skull shape track one another so that their integration is evidenced in two structures that fit soundly regardless of changes in biomechanical and physiologic functions. Evidence for this tight correspondence is also seen in diseases of the craniofacial complex that are often classified as diseases of the skull (e.g., craniosynostosis) or diseases of the brain (e.g., holoprosencephaly) even when both tissues are affected. Our review suggests a model that links brain and skull morphogenesis through coordinated integration of signaling pathways (e.g., FGF, TGFβ, Wnt) via processes that are not currently understood, perhaps involving the meninges. Differences in the earliest signaling of biological structure establish divergent designs that will be enhanced during morphogenesis. Signaling systems that pattern the developing brain are also active in patterning required for growth and assembly of the skull and some members of these signaling families have been indicated as causal for craniofacial diseases. Because cells of early brain and skull are sensitive to similar signaling families, variation in the strength or timing of signals or shifts in patterning boundaries that affect one system (neural or skull) could also affect the other system and appropriate co-adjustments in development would be made. Interactions of these signaling systems and of the tissues that they pattern are fundamental to the consistent but labile functional and structural association of brain and skull conserved over evolutionary time obvious in the study of development and disease. PMID:23525521

Dandy-Walker syndrome with severe velopharyngeal dysfunction: a contraindication for Le Fort I surgery?

PubMed

Nelke, Kamil H; Pawlak, Wojciech; Gerber, Hanna

2015-01-01

Dandy-Walker syndrome is a rare congenital brain deformation. Most symptoms are related with fourth ventricle and skull base malformations. Quite often, symptoms develop from infancy or progress rapidly. Cerebellar dysfunction, lack of muscle coordination, and skull deformities involving eye movement might be present. There are several Dandy-Walker syndrome complex types. We present a 23-year-old patient who had a severe dentofacial deformity with mandibular prognathism and extremely undeveloped maxillary bone resulting in palatopharyngeal and velopharyngeal dysfunction with complete lack of soft palate function resulting in increased speech tone and volume. Performing Le Fort I osteotomy in this case is greatly controversial and might result in even greater loss of function or even its total lack. Velopharyngeal complex is very important, and every surgeon should consider its value while planning Le Fort I osteotomies.

The occipitofrontal circumference: reliable prediction of the intracranial volume in children with syndromic and complex craniosynostosis.

PubMed

Rijken, Bianca Francisca Maria; den Ottelander, Bianca Kelly; van Veelen, Marie-Lise Charlotte; Lequin, Maarten Hans; Mathijssen, Irene Margreet Jacqueline

2015-05-01

OBJECT Patients with syndromic and complex craniosynostosis are characterized by the premature fusion of one or more cranial sutures. These patients are at risk for developing elevated intracranial pressure (ICP). There are several factors known to contribute to elevated ICP in these patients, including craniocerebral disproportion, hydrocephalus, venous hypertension, and obstructive sleep apnea. However, the causal mechanism is unknown, and patients develop elevated ICP even after skull surgery. In clinical practice, the occipitofrontal circumference (OFC) is used as an indirect measure for intracranial volume (ICV), to evaluate skull growth. However, it remains unknown whether OFC is a reliable predictor of ICV in patients with a severe skull deformity. Therefore, in this study the authors evaluated the relation between ICV and OFC. METHODS Eighty-four CT scans obtained in 69 patients with syndromic and complex craniosynostosis treated at the Erasmus University Medical Center-Sophia Children's Hospital were included. The ICV was calculated based on CT scans by using autosegmentation with an HU threshold < 150. The OFC was collected from electronic patient files. The CT scans and OFC measurements were matched based on a maximum amount of the time that was allowed between these examinations, which was dependent on age. A Pearson correlation coefficient was calculated to evaluate the correlations between OFC and ICV. The predictive value of OFC, age, and sex on ICV was then further evaluated using a univariate linear mixed model. The significant factors in the univariate analysis were subsequently entered in a multivariate mixed model. RESULTS The correlations found between OFC and ICV were r = 0.908 for the total group (p < 0.001), r = 0.981 for Apert (p < 0.001), r = 0.867 for Crouzon-Pfeiffer (p < 0.001), r = 0.989 for Muenke (p < 0.001), r = 0.858 for Saethre- Chotzen syndrome (p = 0.001), and r = 0.917 for complex craniosynostosis (p < 0.001). Age and OFC were significant predictors of ICV in the univariate linear mixed model (p < 0.001 for both factors). The OFC was the only predictor that remained significant in the multivariate analysis (p < 0.001). CONCLUSIONS The OFC is a significant predictor of ICV in patients with syndromic and complex craniosynostosis. Therefore, measuring the OFC during clinical practice is very useful in determining which patients are at risk for impaired skull growth.

Annual National Test and Evaluation Conference (27th) Held in Tampa, Florida on March 14-17, 2011

DTIC Science & Technology

2011-03-17

Based Test & Evaluation PETALLINGFRAGMENTATION RADIAL FRACTUREBRITTLE FRACTURE DUCTILE HOLE GROWTH PLUGGING THREAT VELOCITY MATERIAL MATERIAL V50 TYPE...Less Complex Less Costly Testing More Complex More Costly PETALLINGFRAGMENTATION RADIAL FRACTUREBRITTLE FRACTURE DUCTILE HOLE GROWTH PLUGGING...Reversible injuries; medical attention required 3 Serious Fracture of skull, penetration < 2 cm Reversible injuries; hospitalization required 4 Severe

Superior and anterior inferior cerebellar arteries and their relationship with cerebello-pontine angle cranial nerves revisited in the light of cranial cephalometric indexes: a cadaveric study.

PubMed

Habibi, Zohreh; Meybodi, Ali Tayebi; Maleki, Farid; Tabatabai, Seyed

2011-01-01

The aim was to clarify the anatomical features of the superior and anterior inferior cerebellar arteries in relation to the trigeminal nerve and acoustic-facial complex and to the bony structures of the skull in a sample of male Iranian cadavers. Bilateral dissections, calvariectomy, and brain evacuation were performed on 31 adult human fresh brains and skull bases to assess the neurovascular associations, and skull base morphometry. Equations were defined to estimate posterior fossa volume and the relationships between bony and neurovascular elements. Eight SCAs were duplicated from origin. There were 9 cases of SCA-trigeminal contacts, which were at the root entry zone in 7. Mean distance from the origin of AICA to the vertebrobasilar junction was 11.80 mm, while 79% of AICAs originated from the lower half of the BA. This was significantly associated with "posterior fossa funneling" and "basilar narrowing" indexes. In most cases AICA crossed the acoustic-facial complex and coursed between neural bundles (48.3%). The AICA reached or entered the internal acoustic canal in 22.6% of cases and was medial to porous in 77.4%. We documented anatomical variations of the superior and anterior inferior cerebellar arteries along with some cephalometric equations with relevant neurovascular anatomy in Iranian cadavers.

Skull Base Invasion Patterns and Survival Outcomes of Nonmelanoma Skin Cancers

PubMed Central

Dundar, Yusuf; Cannon, Richard B.; Monroe, Marcus M.; Buchmann, Luke Oliver; Hunt, Jason Patrick

2016-01-01

Objective Report routes of skull base invasion for head and neck nonmelanoma skin cancers (NMSCs) and their survival outcomes. Design Retrospective. Participants Ninety patients with NMSC with skull base invasion between 2004 and 2014. Major Outcome Measures Demographic, tumor characteristics, and treatments associated with different types of skull base invasion and disease-specific survival (DSS) and overall survival (OS). Results Perineural invasion (PNI) to the skull base occurred in 69% of patients, whereas 38% had direct skull base invasion. Age, histology, orbital invasion, active immunosuppression, cranial nerve (CN) involved, and type of skull base invasion were significantly associated with DSS and OS (p < 0.05). Patients with basal cell carcinoma (BCC) had significantly improved DSS and OS compared with other histologies (p < 0.05). Patients with CN V PNI had significantly improved DSS and OS compared with CN VII PNI (p < 0.05). Patients with zone II PNI had significantly improved DSS and OS compared with those with direct invasion or zone III PNI (p < 0.05). Nonsurgical therapy was rarely used and is associated with a reduction in DSS and OS (p < 0.05). Conclusion Patterns and survival outcomes for NMSC skull base invasion are reported. Zone II PNI, BCC, and CN V PNI are associated with improved survival outcomes. PMID:28321381

[Application of neuroendoscope in the treatment of skull base chordoma].

PubMed

Zhang, Ya-Zhuo; Wang, Zong-Cheng; Zong, Xu-Yi; Wang, Xin-Sheng; Gui, Song-Bai; Zhao, Peng; Li, Chu-Zhong; He, Yue; Wang, Hong-Yun

2011-07-05

To further explore the application, approach, indication and prognosis of neuroendoscope treatment for skull base chordoma. A total of 101 patients of skull base chordoma were admitted at our hospital from May 2000 to April 2010. There were 59 males and 42 females. Their major clinical manifestations included headache, cranial nerve damage and dyspnea. They were classified according to the patterns of tumor growth: Type I (n = 13): tumor location at a single component of skull base, i. e. clivus or sphenoid sinus with intact cranial dura; Type II (n = 56): tumor involving more than two components of skull e. g clivus, sphenoid and nasal/oral cavity, etc. But there was no intracranial invasion; Type III (n = 32) : tumor extending widely and intradurally forming compression of brain stems and multiple cranial nerves. Based on the types of chordoma, different endoscopic approaches were employed, viz. transnasal, transoral, trans-subtemporal fossa and plus microsurgical craniotomy for staging in some complex cases. Among all patients, total resection was achieved (n = 19), subtotal (n = 58) and partial (n = 24). In partial resection cases, 16 cases were considered to be subtotal due to a second-stage operation. Most cases had conspicuous clinical improvements. Self-care recovery within one week post-operation accounted for 58.4%, two weeks 30.7%, one month 6.9% and more than one month 1.9%. Postoperative complications occurred in 13 cases (12.8%) and included CSF leakage (n = 4) cranial nerve palsy (n = 5), hemorrhagic nasal wounds (n = 3) and delayed intracranial hemorrhage (n = 1). All of these were cured or improved after an appropriate treatment. A follow-up of 6 - 60 months was conducted in 56 cases. Early detection and early treatment are crucial for achieving a better outcome in chordoma. Neuroendoscopic treatment plays an important role in managing those complicated cases. Precise endoscopic techniques plus different surgical approaches and staging procedures are required to improve the post-operative quality of life for patients.

Three-dimensional stereotactic atlas of the adult human skull correlated with the brain, cranial nerves, and intracranial vasculature.

PubMed

Nowinski, Wieslaw L; Thaung, Thant Shoon Let; Chua, Beng Choon; Yi, Su Hnin Wut; Ngai, Vincent; Yang, Yili; Chrzan, Robert; Urbanik, Andrzej

2015-05-15

Although the adult human skull is a complex and multifunctional structure, its 3D, complete, realistic, and stereotactic atlas has not yet been created. This work addresses the construction of a 3D interactive atlas of the adult human skull spatially correlated with the brain, cranial nerves, and intracranial vasculature. The process of atlas construction included computed tomography (CT) high-resolution scan acquisition, skull extraction, skull parcellation, 3D disarticulated bone surface modeling, 3D model simplification, brain-skull registration, 3D surface editing, 3D surface naming and color-coding, integration of the CT-derived 3D bony models with the existing brain atlas, and validation. The virtual skull model created is complete with all 29 bones, including the auditory ossicles (being among the smallest bones). It contains all typical bony features and landmarks. The created skull model is superior to the existing skull models in terms of completeness, realism, and integration with the brain along with blood vessels and cranial nerves. This skull atlas is valuable for medical students and residents to easily get familiarized with the skull and surrounding anatomy with a few clicks. The atlas is also useful for educators to prepare teaching materials. It may potentially serve as a reference aid in the reading and operating rooms. Copyright © 2015 Elsevier B.V. All rights reserved.

Skull Base Inverted Papilloma: A Comprehensive Review

PubMed Central

Wassef, Shafik N.; Batra, Pete S.; Barnett, Samuel

2012-01-01

Skull base inverted papilloma (IP) is an unusual entity for many neurosurgeons. IP is renowned for its high rate of recurrence, its ability to cause local destruction, and its association with malignancy. This paper is a comprehensive review of the reports, studies, and reviews published in the current biomedical literature from 1947 to September 2010 and synthesize this information to focus on its potential invasion to the base of the skull and possible intradural extension. The objective is to familiarize the clinician with the different aspects of this unusual disease. The role of modern diagnostic tools in medical imaging in order to assess clearly the limits of the tumors and to enhance the efficiency and the safety in the choice of a surgical approach is pointed out. The treatment guidelines for IP have undergone a complex evolution that continues today. Radical excision of the tumour is technically difficult and often incomplete. Successful management of IP requires resection of the affected mucosa which could be achieved with open surgery, endoscopic, or combined approach. Radio and chemotherapy were used for certain indications. More optimally research would be a multicenter randomized trials with large size cohorts. PMID:23346418

[The Base of the Skull. Rudolf Virchow between Pathology and Anthropology].

PubMed

Seemann, Sophie

2016-01-01

Throughout his scientific career, the pathologist and anthropologist Rudolf Virchow (1821-1902) examined countless skulls, gradually changing his perspective on this object of research. Initially, he was mainly concerned with pathologically deformed skulls. From the 1850s onwards, he gradually developed a more anthropological approach, and anthropology increasingly came to dominate his scientific interest. This article shows how different influences became central for the establishment of his specific and dynamic model of the human skull development and its successful application in anthropology. Crucial for this process were Virchow's collaboration with his teacher Robert Froriep (1804-1861) in the department of pathology of the Charité, his research on cretinism and rickets, as well as his description of the base of the skull as the center of skull development. His research work was attended by and showed a reciprocal interaction with the buildup of large skull collections. This article uses Virchow's original publications on skull pathology as well as his still preserved skull specimens from the collection of the Berlin Museum of Medical History at the Charité for an integrated text and object based analysis.

Model-based surgical planning and simulation of cranial base surgery.

PubMed

Abe, M; Tabuchi, K; Goto, M; Uchino, A

1998-11-01

Plastic skull models of seven individual patients were fabricated by stereolithography from three-dimensional data based on computed tomography bone images. Skull models were utilized for neurosurgical planning and simulation in the seven patients with cranial base lesions that were difficult to remove. Surgical approaches and areas of craniotomy were evaluated using the fabricated skull models. In preoperative simulations, hand-made models of the tumors, major vessels and nerves were placed in the skull models. Step-by-step simulation of surgical procedures was performed using actual surgical tools. The advantages of using skull models to plan and simulate cranial base surgery include a better understanding of anatomic relationships, preoperative evaluation of the proposed procedure, increased understanding by the patient and family, and improved educational experiences for residents and other medical staff. The disadvantages of using skull models include the time and cost of making the models. The skull models provide a more realistic tool that is easier to handle than computer-graphic images. Surgical simulation using models facilitates difficult cranial base surgery and may help reduce surgical complications.

A Novel Augmented Reality Navigation System for Endoscopic Sinus and Skull Base Surgery: A Feasibility Study

PubMed Central

Li, Liang; Yang, Jian; Chu, Yakui; Wu, Wenbo; Xue, Jin; Liang, Ping; Chen, Lei

2016-01-01

Objective To verify the reliability and clinical feasibility of a self-developed navigation system based on an augmented reality technique for endoscopic sinus and skull base surgery. Materials and Methods In this study we performed a head phantom and cadaver experiment to determine the display effect and accuracy of our navigational system. We compared cadaver head-based simulated operations, the target registration error, operation time, and National Aeronautics and Space Administration Task Load Index scores of our navigation system to conventional navigation systems. Results The navigation system developed in this study has a novel display mode capable of fusing endoscopic images to three-dimensional (3-D) virtual images. In the cadaver head experiment, the target registration error was 1.28 ± 0.45 mm, which met the accepted standards of a navigation system used for nasal endoscopic surgery. Compared with conventional navigation systems, the new system was more effective in terms of operation time and the mental workload of surgeons, which is especially important for less experienced surgeons. Conclusion The self-developed augmented reality navigation system for endoscopic sinus and skull base surgery appears to have advantages that outweigh those of conventional navigation systems. We conclude that this navigational system will provide rhinologists with more intuitive and more detailed imaging information, thus reducing the judgment time and mental workload of surgeons when performing complex sinus and skull base surgeries. Ultimately, this new navigational system has potential to increase the quality of surgeries. In addition, the augmented reality navigational system could be of interest to junior doctors being trained in endoscopic techniques because it could speed up their learning. However, it should be noted that the navigation system serves as an adjunct to a surgeon’s skills and knowledge, not as a substitute. PMID:26757365

A Novel Augmented Reality Navigation System for Endoscopic Sinus and Skull Base Surgery: A Feasibility Study.

PubMed

Li, Liang; Yang, Jian; Chu, Yakui; Wu, Wenbo; Xue, Jin; Liang, Ping; Chen, Lei

2016-01-01

To verify the reliability and clinical feasibility of a self-developed navigation system based on an augmented reality technique for endoscopic sinus and skull base surgery. In this study we performed a head phantom and cadaver experiment to determine the display effect and accuracy of our navigational system. We compared cadaver head-based simulated operations, the target registration error, operation time, and National Aeronautics and Space Administration Task Load Index scores of our navigation system to conventional navigation systems. The navigation system developed in this study has a novel display mode capable of fusing endoscopic images to three-dimensional (3-D) virtual images. In the cadaver head experiment, the target registration error was 1.28 ± 0.45 mm, which met the accepted standards of a navigation system used for nasal endoscopic surgery. Compared with conventional navigation systems, the new system was more effective in terms of operation time and the mental workload of surgeons, which is especially important for less experienced surgeons. The self-developed augmented reality navigation system for endoscopic sinus and skull base surgery appears to have advantages that outweigh those of conventional navigation systems. We conclude that this navigational system will provide rhinologists with more intuitive and more detailed imaging information, thus reducing the judgment time and mental workload of surgeons when performing complex sinus and skull base surgeries. Ultimately, this new navigational system has potential to increase the quality of surgeries. In addition, the augmented reality navigational system could be of interest to junior doctors being trained in endoscopic techniques because it could speed up their learning. However, it should be noted that the navigation system serves as an adjunct to a surgeon's skills and knowledge, not as a substitute.

Panorama of Reconstruction of Skull Base Defects: From Traditional Open to Endonasal Endoscopic Approaches, from Free Grafts to Microvascular Flaps

PubMed Central

Reyes, Camilo; Mason, Eric; Solares, C. Arturo

2014-01-01

Introduction A substantial body of literature has been devoted to the distinct characteristics and surgical options to repair the skull base. However, the skull base is an anatomically challenging location that requires a three-dimensional reconstruction approach. Furthermore, advances in endoscopic skull base surgery encompass a wide range of surgical pathology, from benign tumors to sinonasal cancer. This has resulted in the creation of wide defects that yield a new challenge in skull base reconstruction. Progress in technology and imaging has made this approach an internationally accepted method to repair these defects. Objectives Discuss historical developments and flaps available for skull base reconstruction. Data Synthesis Free grafts in skull base reconstruction are a viable option in small defects and low-flow leaks. Vascularized flaps pose a distinct advantage in large defects and high-flow leaks. When open techniques are used, free flap reconstruction techniques are often necessary to repair large entry wound defects. Conclusions Reconstruction of skull base defects requires a thorough knowledge of surgical anatomy, disease, and patient risk factors associated with high-flow cerebrospinal fluid leaks. Various reconstruction techniques are available, from free tissue grafting to vascularized flaps. Possible complications that can befall after these procedures need to be considered. Although endonasal techniques are being used with increasing frequency, open techniques are still necessary in selected cases. PMID:25992142

Chordomas of the Skull Base, Mobile Spine, and Sacrum: An Epidemiologic Investigation of Presentation, Treatment, and Survival.

PubMed

Zuckerman, Scott L; Bilsky, Mark H; Laufer, Ilya

2018-05-01

Chordomas are rare primary bone tumors that arise from the axial skeleton. Our objective was to analyze trends in radiation and surgery over time and determine location-based survival predictors for chordomas of the skull base, mobile spine, and sacrum. A retrospective cohort study of the SEER (Surveillance Epidemiology and End Results) database from 1973 to 2013 was conducted. All patients had histologically confirmed chordomas. The principal outcome measure was overall survival (OS). The cohort included 1616 patients: skull base (664), mobile spine (444), and sacrum (508). Skull base tumors presented earliest in life (47.4 years) and sacral tumors presented latest (62.7 years). Rates of radiation remained stable for skull base and mobile spine tumors but declined for sacral tumors (P = 0.006). Rates of surgical resection remained stable for skull base and sacral tumors but declined for mobile spine tumors (P = 0.046). Skull base chordomas had the longest median survival (162 months) compared with mobile spine (94 months) and sacral tumors (87 months). Being married was independently associated with improved OS for skull base tumors (hazard ratio, 0.73; 95% confidence interval, 0.53-0.99; P = 0.044). Surgical resection was independently associated with improved OS for sacral chordomas (hazard ratio, 0.48; 95% confidence interval, 0.34-0.69; P < 0.001). Surgical resection for mobile spine chordomas and radiation for sacral chordomas decreased over time. Patients with skull base tumors survived longer than did patients with mobile spine and sacral chordomas, and surgical resection was associated with improved survival in sacral chordomas only. Understanding the behavior of these tumors can help cranial and spinal surgeons improve treatment in this patient population. Copyright © 2018 Elsevier Inc. All rights reserved.

Application of CUSA Excel ultrasonic aspiration system in resection of skull base meningiomas.

PubMed

Tang, Hailiang; Zhang, Haishi; Xie, Qing; Gong, Ye; Zheng, Mingzhe; Wang, Daijun; Zhu, Hongda; Chen, Xiancheng; Zhou, Liangfu

2014-12-01

Here, we introduced our short experience on the application of a new CUSA Excel ultrasonic aspiration system, which was provided by Integra Lifesciences corporation, in skull base meningiomas resection. Ten patients with anterior, middle skull base and sphenoid ridge meningioma were operated using the CUSA Excel ultrasonic aspiration system at the Neurosurgery Department of Shanghai Huashan Hospital from August 2014 to October 2014. There were six male and four female patients, aged from 38 to 61 years old (the mean age was 48.5 years old). Five cases with tumor located at anterior skull base, three cases with tumor on middle skull base, and two cases with tumor on sphenoid ridge. All the patents received total resection of meningiomas with the help of this new tool, and the critical brain vessels and nerves were preserved during operations. All the patients recovered well after operation. This new CUSA Excel ultrasonic aspiration system has the advantage of preserving vital brain arteries and cranial nerves during skull base meningioma resection, which is very important for skull base tumor operations. This key step would ensure a well prognosis for patients. We hope the neurosurgeons would benefit from this kind of technique.

Skull Base Erosion Resulting From Primary Tumors of the Temporomandibular Joint and Skull Base Region: Our Classification and Reconstruction Experience.

PubMed

Chen, Min-Jie; Yang, Chi; Zheng, Ji-Si; Bai, Guo; Han, Zi-Xiang; Wang, Yi-Wen

2018-06-01

We sought to introduce our classification and reconstruction protocol for skull base erosions in the temporomandibular joint and skull base region. Patients with neoplasms in the temporomandibular joint and skull base region treated from January 2006 to March 2017 were reviewed. Skull base erosion was classified into 3 types according to the size of the defect. We included 33 patients, of whom 5 (15.2%) had type I defects (including 3 in whom free fat grafts were placed and 2 in whom deep temporal fascial fat flaps were placed). There were 8 patients (24.2%) with type II defects, all of whom received deep temporal fascial fat flaps. A total of 20 patients (60.6%) had type III defects, including 17 in whom autogenous bone grafts were placed, 1 in whom titanium mesh was placed, and 2 who received total alloplastic joints. The mean follow-up period was 50 months. All of the patients exhibited stable occlusion and good facial symmetry. No recurrence was noted. Our classification and reconstruction principles allowed reliable morpho-functional skull base reconstruction. Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Anisotropic composite human skull model and skull fracture validation against temporo-parietal skull fracture.

PubMed

Sahoo, Debasis; Deck, Caroline; Yoganandan, Narayan; Willinger, Rémy

2013-12-01

A composite material model for skull, taking into account damage is implemented in the Strasbourg University finite element head model (SUFEHM) in order to enhance the existing skull mechanical constitutive law. The skull behavior is validated in terms of fracture patterns and contact forces by reconstructing 15 experimental cases. The new SUFEHM skull model is capable of reproducing skull fracture precisely. The composite skull model is validated not only for maximum forces, but also for lateral impact against actual force time curves from PMHS for the first time. Skull strain energy is found to be a pertinent parameter to predict the skull fracture and based on statistical (binary logistical regression) analysis it is observed that 50% risk of skull fracture occurred at skull strain energy of 544.0mJ. © 2013 Elsevier Ltd. All rights reserved.

The effect of the skull of low-birthweight neonates on applied potential tomography imaging of centralised resistivity changes.

PubMed

McArdle, F J; Brown, B H; Pearse, R G; Barber, D C

1988-01-01

An investigation is presented into the likely effects of the neonatal skull on impedance images produced by applied potential tomography (APT) by imaging impedance changes inside the skull of a human infant of occipito-frontal circumference 30 cm. Measurements have been made with the skull immersed in a tank of saline and electrodes fixed to the perimeter of the tank. Sensitivity measurements have been assessed for imaging a small target close to the centre of the skull as compared with images produced without the skull. The results obtained compare favourably with measurements on a more realistic model of the neonatal head constructed by filling the skull with agar jelly to leave only a thin exterior coating of jelly to simulate the scalp. These experiments suggest that in the central region of the head of a neonate, measured changes by the APT technique are about 44% of that expected from a homogeneous phantom, but that this might vary from 32% to 55% at different points in the image in a very complex manner.

Modified three-dimensional skull base model with artificial dura mater, cranial nerves, and venous sinuses for training in skull base surgery: technical note.

PubMed

Mori, Kentaro; Yamamoto, Takuji; Oyama, Kazutaka; Ueno, Hideaki; Nakao, Yasuaki; Honma, Keiichirou

2008-12-01

Experience with dissection of the cavernous sinus and the temporal bone is essential for training in skull base surgery, but the opportunities for cadaver dissection are very limited. A modification of a commercially available prototype three-dimensional (3D) skull base model, made by a selective laser sintering method and incorporating surface details and inner bony structures such as the inner ear structures and air cells, is proposed to include artificial dura mater, cranial nerves, venous sinuses, and the internal carotid artery for such surgical training. The transpetrosal approach and epidural cavernous sinus surgery (Dolenc's technique) were performed on this modified model using a high speed drill or ultrasonic bone curette under an operating microscope. The model could be dissected in almost the same way as a real cadaver. The modified 3D skull base model provides a good educational tool for training in skull base surgery.

Harvey Cushing's Approaches to Tumors in His Early Career: From the Skull Base to the Cranial Vault

PubMed Central

Pendleton, Courtney; Raza, Shaan M.; Gallia, Gary L.; Quiñones-Hinojosa, Alfredo

2011-01-01

In this report, we review Dr. Cushing's early surgical cases at the Johns Hopkins Hospital, revealing details of his early operative approaches to tumors of the skull base and cranial vault. Following Institutional Review Board approval, and through the courtesy of the Alan Mason Chesney Archives, we reviewed the Johns Hopkins Hospital surgical files from 1896 to 1912. Participants included four adult patients and one child who underwent surgical resection of bony tumors of the skull base and the cranial vault. The main outcome measures were operative approach and condition recorded at the time of discharge. The indications for surgery included unspecified malignant tumor of the basal meninges and temporal bone, basal cell carcinoma, osteoma of the posterior skull base, and osteomas of the frontal and parietofrontal cranial vault. While Cushing's experience with selected skull base pathology has been previously reported, the breadth of his contributions to operative approaches to the skull base has been neglected. PMID:22470271

Evolving the Concept of Homology

ERIC Educational Resources Information Center

Naples, Virginia L.; Miller, Jon S.

2009-01-01

Understanding homology is fundamental to learning about evolution. The present study shows an exercise that can be varied in complexity, for which students compile research illustrating the fate of homologous fish skull elements, and assemble a mural to serve as a learning aid. The skull of the most primitive living Actinopterygian (bony fish),…

Embryonic development of the skull of the Andean lizard Ptychoglossus bicolor (Squamata, Gymnophthalmidae)

PubMed Central

Hernández-Jaimes, Carlos; Jerez, Adriana; Ramírez-Pinilla, Martha Patricia

2012-01-01

The study of cranial design and development in Gymnophthalmidae is important to understand the ontogenetic processes behind the morphological diversity of the group and to examine the possible effects of microhabitat use and other ecological parameters, as well as phylogenetic constraints, on skull anatomy. Complete morphological descriptions of embryonic skull development within Gymnophthalmidae are non-existent. Likewise, very little is known about the complete chondrocranium of the family. Herein, the development of the skull of the semi-fossorial lizard Ptychoglossus bicolor is described along with an examination of the chondrocranium of other gymnophthalmid taxa and the teiid Cnemidophorus lemniscatus. Cranial chondrification begins with early condensations in the ethmoid, orbitotemporal and occipital regions of the chondrocranium as well as the viscerocranium. Ossification of the skull starts with elements of the dermatocranium (pterygoid, prefrontal, maxilla and jugal). The orbitosphenoid is the last chondral bone to appear. At birth, the skull is almost completely ossified and exhibits a large frontoparietal fontanelle. In general terms, the chondrocranium of the gymnophthalmids studied is characteristic of lacertiform terrestrial lizards, in spite of their life habits, and resembles the chondrocranium of C. lemniscatus in many aspects. However, the gymnophthalmids show great variation in the orbitosphenoid and a complex nasal capsule. The latter exhibits greater development of some nasal cartilages, which make it more complex than in C. lemniscatus. These characteristics might be related to microhabitat use and the well-developed olfactory and vomeronasal systems observed within this clade. PMID:22881276

Application of CUSA Excel ultrasonic aspiration system in resection of skull base meningiomas

PubMed Central

Tang, Hailiang; Zhang, Haishi; Xie, Qing; Zheng, Mingzhe; Wang, Daijun; Zhu, Hongda; Chen, Xiancheng; Zhou, Liangfu

2014-01-01

Background Here, we introduced our short experience on the application of a new CUSA Excel ultrasonic aspiration system, which was provided by Integra Lifesciences corporation, in skull base meningiomas resection. Methods Ten patients with anterior, middle skull base and sphenoid ridge meningioma were operated using the CUSA Excel ultrasonic aspiration system at the Neurosurgery Department of Shanghai Huashan Hospital from August 2014 to October 2014. There were six male and four female patients, aged from 38 to 61 years old (the mean age was 48.5 years old). Five cases with tumor located at anterior skull base, three cases with tumor on middle skull base, and two cases with tumor on sphenoid ridge. Results All the patents received total resection of meningiomas with the help of this new tool, and the critical brain vessels and nerves were preserved during operations. All the patients recovered well after operation. Conclusions This new CUSA Excel ultrasonic aspiration system has the advantage of preserving vital brain arteries and cranial nerves during skull base meningioma resection, which is very important for skull base tumor operations. This key step would ensure a well prognosis for patients. We hope the neurosurgeons would benefit from this kind of technique. PMID:25561762

Bolstering the Nasoseptal Flap Using Sphenoid Sinus Fat Packing: A Technical Case Report.

PubMed

Abou-Al-Shaar, Hussam; Zaidi, Hasan A; Cote, David J; Laws, Edward R

2017-03-01

Resection of extensive skull base lesions often necessitates relatively large dural openings and arachnoid, resulting in skull base defects with the potential for a postoperative cerebrospinal fluid leak. A nasoseptal flap (NSF) is a vascularized graft that has greatly diminished the incidence of cerebrospinal fluid leak. Annealing of flaps against the ventral skull base can be tenuous within the first few days after surgery. We report the use of sphenoid sinus fat packing as a buttress to support the nasoseptal flap during skull base reconstruction. A 37-year-old man presented with pan-hypopituitarism, bitemporal hemianopsia, and imaging consistent with a craniopharyngioma. He underwent an endoscopic endonasal approach with resection of the planum and tuberculum sphenoidale for resection of this mass. An NSF was harvested, and a combination of suprasellar fat packing, tensor fasciae lata graft, and Porex plate along with the flap were used to reconstruct the skull base. Postoperatively, he precipitously experienced copious rhinorrhea necessitating surgical re-exploration. A redundant segment of the NSF had retracted into the sphenoid sinus, and was no longer supported against the ventral skull base. We repositioned the NSF and used sphenoid sinus fat packing to help support the graft against the ventral skull base. A postoperative computed tomographic scan demonstrated a clear delineation between the vascularized graft and the fat packing, confirming proper positioning of the flap. Sphenoid sinus fat packing can be an important technical adjunct in bolstering the nasoseptal flap against the ventral skull base in the tenuous early perioperative period. Copyright © 2016 Elsevier Inc. All rights reserved.

Management Strategies for Skull Base Inverted Papilloma.

PubMed

Grayson, Jessica W; Khichi, Sunny S; Cho, Do-Yeon; Riley, Kristen O; Woodworth, Bradford A

2016-07-01

Inverted papilloma attached to the ventral skull base presents a surgical dilemma because surgical removal of the bony pedicle is critical to decrease risk of recurrence. The objective of this study is to evaluate the effectiveness of endoscopic management of skull base inverted papilloma. Case series with planned data collection. Tertiary medical center. Patients with skull base inverted papilloma. Over 7 years, 49 patients with skull base inverted papilloma were referred for surgical resection. Demographics, operative technique, pathology, complications, recurrence, and postoperative follow-up were evaluated. Average age at presentation was 57 years. Twenty-six patients (53%) had prior attempts at resection elsewhere, and 5 had squamous cell carcinoma (SCCA) arising in an inverted papilloma. Six patients (12%) suffered major complications, including skull base osteomyelitis in 2 previously irradiated patients, cerebrospinal fluid leak with pneumocephalus (n = 1), meningitis (n = 1), invasive fungal sinusitis (n = 1), and cerebrovascular accident (n = 1). The mean disease-free interval was 29 months (range, 10-78 months). One patient with SCCA recurred in the nasopharynx (overall 2% recurrence rate). He is disease-free 3 years following endoscopic nasopharyngectomy. Three patients with SCCA had endoscopic resection of the skull base, while 1 subject with inverted papilloma pedicled on the superior orbital roof had an osteoplastic flap in conjunction with a Draf III procedure. All others received endoscopic resection. Removal of the bony pedicle resulted in excellent local control of skull base inverted papillomas. Our experience demonstrates that disease eradication with limited morbidity is attainable with this approach. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Fatal carotid dissection after blunt head trauma.

PubMed

Tartara, F; Regolo, P; Servadei, F; Versari, P P; Giovanelli, M

2000-06-01

Occurrence of internal carotid artery injuries associated with skull base fracture has been reported. A. report a case of fatal intracranial carotid dissection related to petrous fracture involving the carotid canal. Identification of carotid lesions may be difficult and generally related to appearance of unexpected neurological deficit. Skull base fractures may be considered an indirect sign for detection of vascular injury. Patterns of the fracture are of paramount importance; routine CT scan may fail to detect basilar fractures and high definition fine-cut CT scan should be executed to carefully identify and evaluate fractures. Temporal and sphenoid bone fractures are common in head trauma and involvement of the course of the carotid artery is frequent. The involvement of the intracranial carotid artery course represents a direct risk factor for lesions of the petrous, lacerum and cavernous segments of the carotid artery. Early diagnosis of post-traumatic vascular injury may lead to prognosis improvement because of effectiveness of heparin anticoagulant therapy. Then vascular screening is recommendable in cases with complex fractures of the skull base and particularly fracturing along the course of the carotid artery. Magnetic resonance angiography may be considered the first line diagnostic tools for vascular screening. Angiography may be reserved for patients with a proven lesion or rapid neurological deterioration taking into account the possibility of interventional treatment.

The application of finite element analysis in the skull biomechanics and dentistry.

PubMed

Prado, Felippe Bevilacqua; Rossi, Ana Cláudia; Freire, Alexandre Rodrigues; Ferreira Caria, Paulo Henrique

2014-01-01

Empirical concepts describe the direction of the masticatory stress dissipation in the skull. The scientific evidence of the trajectories and the magnitude of stress dissipation can help in the diagnosis of the masticatory alterations and the planning of oral rehabilitation in the different areas of Dentistry. The Finite Element Analysis (FEA) is a tool that may reproduce complex structures with irregular geometries of natural and artificial tissues of the human body because it uses mathematical functions that enable the understanding of the craniofacial biomechanics. The aim of this study was to review the literature on the advantages and limitations of FEA in the skull biomechanics and Dentistry study. The keywords of the selected original research articles were: Finite element analysis, biomechanics, skull, Dentistry, teeth, and implant. The literature review was performed in the databases, PUBMED, MEDLINE and SCOPUS. The selected books and articles were between the years 1928 and 2010. The FEA is an assessment tool whose application in different areas of the Dentistry has gradually increased over the past 10 years, but its application in the analysis of the skull biomechanics is scarce. The main advantages of the FEA are the realistic mode of approach and the possibility of results being based on analysis of only one model. On the other hand, the main limitation of the FEA studies is the lack of anatomical details in the modeling phase of the craniofacial structures and the lack of information about the material properties.

Cranial ontogenetic variation in early saurischians and the role of heterochrony in the diversification of predatory dinosaurs.

PubMed

Foth, Christian; Hedrick, Brandon P; Ezcurra, Martin D

2016-01-01

Non-avian saurischian skulls underwent at least 165 million years of evolution and shapes varied from elongated skulls, such as in the theropod Coelophysis, to short and box-shaped skulls, such as in the sauropod Camarasaurus. A number of factors have long been considered to drive skull shape, including phylogeny, dietary preferences and functional constraints. However, heterochrony is increasingly being recognized as an important factor in dinosaur evolution. In order to quantitatively analyse the impact of heterochrony on saurischian skull shape, we analysed five ontogenetic trajectories using two-dimensional geometric morphometrics in a phylogenetic framework. This allowed for the comparative investigation of main ontogenetic shape changes and the evaluation of how heterochrony affected skull shape through both ontogenetic and phylogenetic trajectories. Using principal component analyses and multivariate regressions, it was possible to quantify different ontogenetic trajectories and evaluate them for evidence of heterochronic events allowing testing of previous hypotheses on cranial heterochrony in saurischians. We found that the skull shape of the hypothetical ancestor of Saurischia likely led to basal Sauropodomorpha through paedomorphosis, and to basal Theropoda mainly through peramorphosis. Paedomorphosis then led from Orionides to Avetheropoda, indicating that the paedomorphic trend found by previous authors in advanced coelurosaurs may extend back into the early evolution of Avetheropoda. Not only are changes in saurischian skull shape complex due to the large number of factors that affected it, but heterochrony itself is complex, with a number of possible reversals throughout non-avian saurischian evolution. In general, the sampling of complete ontogenetic trajectories including early juveniles is considerably lower than the sampling of single adult or subadult individuals, which is a major impediment to the study of heterochrony on non-avian dinosaurs. Thus, the current work represents an exploratory analysis. To better understand the cranial ontogeny and the impact of heterochrony on skull evolution in saurischians, the data set that we present here must be expanded and complemented with further sampling from future fossil discoveries, especially of juvenile individuals.

Microsurgical resection of skull base meningioma-expanding the operative corridor.

PubMed

Raheja, Amol; Couldwell, William T

2016-11-01

A better understanding of surgical anatomy, marked improvement in illumination devices, provision of improved hemostatic agents, greater availability of more precise surgical instruments, and better modalities for skull base reconstruction have led to an inevitable evolution of skull base neurosurgery. For the past few decades, many skull base neurosurgeons have worked relentlessly to improve the surgical approach and trajectory for the expansion of operative corridor. With the advent of newer techniques and their rapid adaptation, it is foundational, especially for young neurosurgeons, to understand the basics and nuances of modifications of traditional neurosurgical approaches. The goal of this topic review is to discuss the evolution of, concepts in, and technical nuances regarding the operative corridor expansion in the field of skull base surgery for intracranial meningioma as they pertain to achieving optimal functional outcome.

The Making of a Skull Base Team and the Value of Multidisciplinary Approach in the Management of Sinonasal and Ventral Skull Base Malignancies.

PubMed

Snyderman, Carl H; Wang, Eric W; Fernandez-Miranda, Juan C; Gardner, Paul A

2017-04-01

The management of sinonasal and ventral skull base malignancies is best performed by a team. Although the composition of the team may vary, it is important to have multidisciplinary representation. There are multiple obstacles, both individual and institutional, that must be overcome to develop a highly functioning team. Adequate training is an important part of team-building and can be fostered with surgical telementoring. A quality improvement program should be incorporated into the activities of a skull base team. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of SPECT/CT, MRI and CT in diagnosis of skull base bone invasion in nasopharyngeal carcinoma.

PubMed

Zhang, Shu-xu; Han, Peng-hui; Zhang, Guo-qian; Wang, Rui-hao; Ge, Yong-bin; Ren, Zhi-gang; Li, Jian-sheng; Fu, Wen-hai

2014-01-01

Early detection of skull base invasion in nasopharyngeal carcinoma (NPC) is crucial for correct staging, assessing treatment response and contouring the tumor target in radiotherapy planning, as well as improving the patient's prognosis. To compare the diagnostic efficacy of single photon emission computed tomography/computed tomography (SPECT/CT) imaging, magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of skull base invasion in NPC. Sixty untreated patients with histologically proven NPC underwent SPECT/CT imaging, contrast-enhanced MRI and CT. Of the 60 patients, 30 had skull base invasion confirmed by the final results of contrast-enhanced MRI, CT and six-month follow-up imaging (MRI and CT). The diagnostic efficacy of the three imaging modalities in detecting skull base invasion was evaluated. The rates of positive findings of skull base invasion for SPECT/CT, MRI and CT were 53.3%, 48.3% and 33.3%, respectively. The sensitivity, specificity and accuracy were 93.3%, 86.7% and 90.0% for SPECT/CT fusion imaging, 96.7%, 100.0% and 98.3% for contrast-enhanced MRI, and 66.7%, 100.0% and 83.3% for contrast-enhanced CT. MRI showed the best performance for the diagnosis of skull base invasion in nasopharyngeal carcinoma, followed closely by SPECT/CT. SPECT/CT had poorer specificity than that of both MRI and CT, while CT had the lowest sensitivity.

High activity iodine 125 endocurietherapy for recurrent skull base tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, P.P.; Good, R.R.; Leibrock, L.G.

1988-04-15

Experience with endocurietherapy of skull base tumors is reviewed. We present our cases of recurrent pituitary hemangiopericytoma, radiation-induced recurrent meningioma, recurrent clival chordoma, recurrent nasopharyngeal cancer involving the cavernous sinus, and recurrent parotid carcinoma of the skull base which were all successfully retreated with high-activity 125-iodine (I-125) permanent implantation.76 references.

[Endonasal skull base endoscopy].

PubMed

Simal-Julián, Juan Antonio; Miranda-Lloret, Pablo; Pancucci, Giovanni; Evangelista-Zamora, Rocío; Pérez-Borredá, Pedro; Sanromán-Álvarez, Pablo; Perez-de-Sanromán, Laila; Botella-Asunción, Carlos

2013-01-01

The endoscopic endonasal techniques used in skull base surgery have evolved greatly in recent years. Our study objective was to perform a qualitative systematic review of the likewise systematic reviews in published English language literature, to examine the evidence and conclusions reached in these studies comparing transcranial and endoscopic approaches in skull base surgery. We searched the references on the MEDLINE and EMBASE electronic databases selecting the systematic reviews, meta-analyses and evidence based medicine reviews on skull based pathologies published from January 2000 until January 2013. We focused on endoscopic impact and on microsurgical and endoscopic technique comparisons. Full endoscopic endonasal approaches achieved gross total removal rates of craniopharyngiomas and chordomas higher than those for transcranial approaches. In anterior skull base meningiomas, complete resections were more frequently achieved after transcranial approaches, with a trend in favour of endoscopy with respect to visual prognosis. Endoscopic endonasal approaches minimised the postoperative complications after the treatment of cerebrospinal fluid (CSF) leaks, encephaloceles, meningoceles, craniopharyngiomas and chordomas, with the exception of postoperative CSF leaks. Randomized multicenter studies are necessary to resolve the controversy over endoscopic and microsurgical approaches in skull base surgery. Copyright © 2013 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

Surgery of the ear and the lateral skull base: pitfalls and complications

PubMed Central

Schick, Bernhard; Dlugaiczyk, Julia

2013-01-01

Surgery of the ear and the lateral skull base is a fascinating, yet challenging field in otorhinolaryngology. A thorough knowledge of the associated complications and pitfalls is indispensable for the surgeon, not only to provide the best possible care to his patients, but also to further improve his surgical skills. Following a summary about general aspects in pre-, intra-and postoperative care of patients with disorders of the ear/lateral skull base, this article covers the most common pitfalls and complications in stapes surgery, cochlear implantation and surgery of vestibular schwannomas and jugulotympanal paragangliomas. Based on these exemplary procedures, basic “dos and don’ts” of skull base surgery are explained, which the reader can easily transfer to other disorders. Special emphasis is laid on functional aspects, such as hearing, balance and facial nerve function. Furthermore, the topics of infection, bleeding, skull base defects, quality of life and indication for revision surgery are discussed. An open communication about complications and pitfalls in ear/lateral skull base surgery among surgeons is a prerequisite for the further advancement of this fascinating field in ENT surgery. This article is meant to be a contribution to this process. PMID:24403973

[Complications and pitfalls in surgery of the ear/lateral skull base].

PubMed

Schick, B; Dlugaiczyk, J

2013-04-01

Surgery of the ear and the lateral skull base is a fascinating, yet challenging field in otorhinolaryngology. A thorough knowledge of the associated complications and pitfalls is indispensable for the surgeon, not only to provide the best possible care to his patients, but also to further improve his surgical skills.Following a summary about general aspects in pre-, intra- and postoperative care of patients with disorders of the ear/lateral skull base, this article covers the most common pitfalls and complications in stapes surgery, cochlear implantation, surgery of vestibular schwannomas, and jugulotympanal paragangliomas. Based on these exemplary procedures, basic "do's and don'ts" of skull base surgery are explained, which the reader can easily transfer to other disorders. Special emphasis is laid on functional aspects, such as hearing, balance and facial nerve function. Furthermore, the topics of infection, bleeding, skull base defects, quality of life and indication for revision surgery are discussed.An open communication about complications and pitfalls in ear/lateral skull base surgery among surgeons is a prerequisite for the further advancement of this fascinating field in ENT surgery. This article is meant to be a contribution to this process. © Georg Thieme Verlag KG Stuttgart · New York.

Deformed Skull Morphology Is Caused by the Combined Effects of the Maldevelopment of Calvarias, Cranial Base and Brain in FGFR2-P253R Mice Mimicking Human Apert Syndrome

PubMed Central

Luo, Fengtao; Xie, Yangli; Xu, Wei; Huang, Junlan; Zhou, Siru; Wang, Zuqiang; Luo, Xiaoqing; Liu, Mi; Chen, Lin; Du, Xiaolan

2017-01-01

Apert syndrome (AS) is a common genetic syndrome in humans characterized with craniosynostosis. Apert patients and mouse models showed abnormalities in sutures, cranial base and brain, that may all be involved in the pathogenesis of skull malformation of Apert syndrome. To distinguish the differential roles of these components of head in the pathogenesis of the abnormal skull morphology of AS, we generated mouse strains specifically expressing mutant FGFR2 in chondrocytes, osteoblasts, and progenitor cells of central nervous system (CNS) by crossing Fgfr2+/P253R-Neo mice with Col2a1-Cre, Osteocalcin-Cre (OC-Cre), and Nestin-Cre mice, respectively. We then quantitatively analyzed the skull and brain morphology of these mutant mice by micro-CT and micro-MRI using Euclidean distance matrix analysis (EDMA). Skulls of Col2a1-Fgfr2+/P253R mice showed Apert syndrome-like dysmorphology, such as shortened skull dimensions along the rostrocaudal axis, shortened nasal bone, and evidently advanced ossification of cranial base synchondroses. The OC-Fgfr2+/P253R mice showed malformation in face at 8-week stage. Nestin-Fgfr2+/P253R mice exhibited increased dorsoventral height and rostrocaudal length on the caudal skull and brain at 8 weeks. Our study indicates that the abnormal skull morphology of AS is caused by the combined effects of the maldevelopment in calvarias, cranial base, and brain tissue. These findings further deepen our knowledge about the pathogenesis of the abnormal skull morphology of AS, and provide new clues for the further analyses of skull phenotypes and clinical management of AS. PMID:28123344

Deformed Skull Morphology Is Caused by the Combined Effects of the Maldevelopment of Calvarias, Cranial Base and Brain in FGFR2-P253R Mice Mimicking Human Apert Syndrome.

PubMed

Luo, Fengtao; Xie, Yangli; Xu, Wei; Huang, Junlan; Zhou, Siru; Wang, Zuqiang; Luo, Xiaoqing; Liu, Mi; Chen, Lin; Du, Xiaolan

2017-01-01

Apert syndrome (AS) is a common genetic syndrome in humans characterized with craniosynostosis. Apert patients and mouse models showed abnormalities in sutures, cranial base and brain, that may all be involved in the pathogenesis of skull malformation of Apert syndrome. To distinguish the differential roles of these components of head in the pathogenesis of the abnormal skull morphology of AS, we generated mouse strains specifically expressing mutant FGFR2 in chondrocytes, osteoblasts, and progenitor cells of central nervous system (CNS) by crossing Fgfr2 +/P253R-Neo mice with Col2a1-Cre, Osteocalcin-Cre (OC-Cre), and Nestin-Cre mice, respectively. We then quantitatively analyzed the skull and brain morphology of these mutant mice by micro-CT and micro-MRI using Euclidean distance matrix analysis (EDMA). Skulls of Col2a1-Fgfr2 +/P253R mice showed Apert syndrome-like dysmorphology, such as shortened skull dimensions along the rostrocaudal axis, shortened nasal bone, and evidently advanced ossification of cranial base synchondroses. The OC-Fgfr2 +/P253R mice showed malformation in face at 8-week stage. Nestin-Fgfr2 +/P253R mice exhibited increased dorsoventral height and rostrocaudal length on the caudal skull and brain at 8 weeks. Our study indicates that the abnormal skull morphology of AS is caused by the combined effects of the maldevelopment in calvarias, cranial base, and brain tissue. These findings further deepen our knowledge about the pathogenesis of the abnormal skull morphology of AS, and provide new clues for the further analyses of skull phenotypes and clinical management of AS.

Lumbar subarachnoid drainage in cerebrospinal fluid leaks after lateral skull base surgery.

PubMed

Allen, Kyle P; Isaacson, Brandon; Purcell, Patricia; Kutz, Joe Walter; Roland, Peter S

2011-12-01

To determine the efficacy of lumbar drainage in managing cerebrospinal fluid (CSF) leak after lateral skull base surgery. Retrospective case review. Academic tertiary referral center. Patients who had a lumbar subarachnoid drain placed after a lateral skull base procedure between July 1999 and February 2010 were included. Patients were identified by searching medical records for lateral skull base approach Current Procedural Terminology codes. The following variables were recorded for each subject: diagnosis, type of lateral skull base operation, duration of lumbar drainage, need for revision surgery, and presence of meningitis. Successful cessation of postoperative CSF leakage. Five hundred eight charts were reviewed, and 63 patients were identified who received a lumbar drain after a lateral skull base operation. The most common diagnosis was acoustic neuroma in 61.9%. The most common skull base approaches were the translabyrinthine, middle fossa, and transpetrosal approaches. Approximately 60.3% of patients had CSF rhinorrhea, 23.8% had an incisional leak, and 14.3% had otorrhea. The mean duration of lumbar drainage was 4.6 days. Forty eight (76.2%) study subjects had resolution of their CSF leak with lumbar drainage. Fifteen patients (23.8%) required revision surgery to stop the CSF leak. Lumbar drainage was successful in 90% of leaks after the translabyrinthine approach but in only 50% of those undergoing a suboccipital approach, which was a statistically significant difference. Postoperative CSF leaks after lateral skull base surgery can be managed with a lumbar subarachnoid drain in a majority of cases but is more successful after the translabyrinthine than the suboccipital approach. Recurrent CSF leaks after lumbar drainage is likely to require a revision operation.

Endoscopic Approach to Remove Intra-extracranial Tumors in Various Skull Base Regions: 10-year Experience of a Single Center

PubMed Central

Zhang, Qiu-Hang; Wang, Zhen-Lin; Guo, Hong-Chuan; Kong, Feng; Yan, Bo; Li, Ming-Chu; Chen, Ge; Liang, Jian-Tao; Bao, Yu-Hai; Ling, Feng

2017-01-01

Background: Some problems have been found in the usually adopted combined approach for the removal of intra-extracranial tumors in skull base. Herein, we described a pure endoscopic transnasal or transoral approach (ETA) for the removal of intra-extracranial tumors in various skull base regions. Methods: Retrospectively, clinical data, major surgical complications, pre- and postoperative images, and follow-up information of a series of 85 patients with intra-extracranial tumors in various skull base regions who were treated by surgery via ETA in our skull base center during the past 10 years were reviewed and analyzed. Results: Gross total tumor removal was achieved in 80/85 cases (94.1%) in this study. All 37 cases with tumors in anterior skull base and all 14 cases with tumors in jugular foramen received total tumor removal. Thirteen and three cases with tumors in clivus received total and subtotal tumor removal, respectively. Total and subtotal tumor removal was performed for 16 cases and 2 cases in lateral skull base, respectively. The complications in this study included: cerebrospinal fluid leakage (n = 3), meningitis (n = 3), and new cranial nerve deficits (n = 3; recovered in 3 months after surgery). In the follow-up period of 40–151 months (median: 77 months), seven patients (8.8%) out of the 80 cases of total tumor removal experienced recurrence. Conclusions: Complete resection of intra-extracranial growing tumors in various skull base regions can be achieved via the pure ETA in one stage in selected cases. Surgical procedure for radical removal of tumors is feasible and safe. PMID:29237926

Repair of bony lateral skull base defects equal to or larger than 10 mm by extracorporeally sewed unit-sandwich graft.

PubMed

Indorewala, Shabbir; Nemade, Gaurav; Indorewala, Abuzar; Mahajan, Gauri

2018-06-23

To see effectiveness of the senior author's repair technique for repair of large (equal to or larger than 10 mm) bony lateral skull base defects. Retrospective. Secondary/tertiary care center. We performed retrospective review of 9 surgeries done in our institution between January 2010 and December 2013 for repair of large lateral bony skull base defects. We defined skull base defects extra-cranially and repaired them intra-cranially. We made an extracorporeal sandwich of autologous fascia-bone-fascia (fascia lata and nasal septal bone) and sewed it together to make it into a unit-sandwich graft. This extracorporeally sewed unit-sandwich graft was then inserted to close the large skull base defects either via (1) a cranial slit-window, or (2) the skull base defect itself. Since skull base is bony, bony repair is preferred. Bone plates that are easily available for skull base repair are calvarial and nasal septal bone. Occasionally, harvest of split calvarial bone carries risk of major complications. We preferred nasal septal bone. Harvesting of septal bone even in children using a posterior incision should not disturb the cartilage growth centers. All nine patients were operated by this technique. We had four patients with cerebrospinal fluid leak, and five patients with brain herniation. All these patients had complete reversal of herniation of cranial contents and cessation of cerebrospinal fluid leak. On imaging, in 6 cases the bone graft remained in original intended position after 12 months of surgery. The bone graft was not identifiable in 3 cases. The senior author's technique using autologous multi-layered graft is simple to master, repeatable and very effective.

Osseointegrated Implant Applications in Cosmetic and Functional Skull Base Rehabilitation

PubMed Central

Benscoter, Brent J.; Jaber, James J.; Kircher, Matthew L.; Marzo, Sam J.; Leonetti, John P.

2011-01-01

This study discusses the indications, outcomes, and complications in patients that underwent osseointegrated implantation for skull base rehabilitation. We conducted a retrospective review of eight patients with skull base defects who had undergone implantation of a facial prosthetic retention device ± bone-anchored hearing aid at a tertiary academic referral center. Descriptive analysis of applications, techniques, outcomes, and complications were reviewed. The majority of patients were males (n = 6) with previously diagnosed skull base malignancy (n = 5) with an average age of 46 (range, 14 to 77). All patients received an implanted facial prosthetic device either for an aural (n = 7) or orbital (n = 1) prosthesis. There were only two complications that included infection (n = 1) and implant extrusion (n = 1). Osseointegrated implantation of abutments for anchoring prosthetic devices in patients for skull base rehabilitation provides an excellent cosmetic option with minimal complications. PMID:22451830

Minimally invasive surgery of the anterior skull base: transorbital approaches

PubMed Central

Gassner, Holger G.; Schwan, Franziska; Schebesch, Karl-Michael

2016-01-01

Minimally invasive approaches are becoming increasingly popular to access the anterior skull base. With interdisciplinary cooperation, in particular endonasal endoscopic approaches have seen an impressive expansion of indications over the past decades. The more recently described transorbital approaches represent minimally invasive alternatives with a differing spectrum of access corridors. The purpose of the present paper is to discuss transorbital approaches to the anterior skull base in the light of the current literature. The transorbital approaches allow excellent exposure of areas that are difficult to reach like the anterior and posterior wall of the frontal sinus; working angles may be more favorable and the paranasal sinus system can be preserved while exposing the skull base. Because of their minimal morbidity and the cosmetically excellent results, the transorbital approaches represent an important addition to established endonasal endoscopic and open approaches to the anterior skull base. Their execution requires an interdisciplinary team approach. PMID:27453759

Head and neck injury patterns in fatal falls: epidemiologic and biomechanical considerations.

PubMed

Freeman, Michael D; Eriksson, Anders; Leith, Wendy

2014-01-01

Fatal falls often involve a head impact, which are in turn associated with a fracture of the skull or cervical spine. Prior authors have noted that the degree of inversion of the victim at the time of impact is an important predictor of the distribution of skull fractures, with skull base fractures more common than skull vault fractures in falls with a high degree of inversion. The majority of fatal fall publications have focused on skull fractures, and no research has described the association between fall circumstances and the distribution of fractures in the skull and neck. In the present study, we accessed data regarding head and neck fractures resulting from fatal falls from a Swedish autopsy database for the years 1992-2010, for the purposes of examining the relationships between skull and cervical spine fracture distribution and the circumstances of the fatal fall. Out of 102,310 medico-legal autopsies performed there were 1008 cases of falls associated with skull or cervical spine fractures. The circumstances of the falls were grouped in 3 statistically homogenous categories; falls occurring at ground level, falls from a height of <3 m or down stairs, and falls from ≥3 m. Only head and neck injuries and fractures that were associated with the fatal CNS injuries were included for study, and categorized as skull vault and skull base fractures, upper cervical injuries (C0-C1 dislocation, C1 and C2 fractures), and lower cervical fractures. Logistic regression modeling revealed increased odds of skull base and lower cervical fracture in the middle and upper fall severity groups, relative to ground level falls (lower cervical <3 m falls, OR = 2.55 [1.32, 4.92]; lower cervical ≥3 m falls, OR = 2.23 [0.98, 5.08]; skull base <3 m falls, OR = 1.82 [1.32, 2.50]; skull base ≥3 m falls, OR = 2.30 [1.55, 3.40]). C0-C1 dislocations were strongly related to fall height, with an OR of 8.3 for ≥3 m falls versus ground level. The findings of increased odds of skull base and lower cervical spine fracture in falls from a height are consistent with prior observations that the risk of such injuries is related to the degree of victim inversion at impact. The finding that C0-C1 dislocations are most common in falls from more than 3 m is unique, an indication that the injuries likely result from high energy shear forces rather than pure tension, as previously thought. Copyright © 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Management of osteomyelitis of the skull base

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benecke, J.E. Jr.

1989-12-01

Osteomyelitis of the skull base is the most severe form of malignant otitis externa. As a result of having treated 13 patients with skull base osteomyelitis over a 4-year period, we have developed a method of staging and monitoring this malady using gallium and technetium scanning techniques. Stage I is localized to soft tissues, stage II is limited osteomyelitis, and stage III represents extensive skull base osteomyelitis. All stages are treated with appropriate antipseudomonal antibiotics. The duration of therapy depends upon the clearing of inflammation as shown on the gallium scan. Each case must be looked at independently and notmore » subjected to an arbitrary treatment protocol.« less

Robotic Anterior and Midline Skull Base Surgery: Preclinical Investigations

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Malley, Bert W.; Weinstein, Gregory S.

Purpose: To develop a minimally invasive surgical technique to access the midline and anterior skull base using the optical and technical advantages of robotic surgical instrumentation. Methods and Materials: Ten experimental procedures focusing on approaches to the nasopharynx, clivus, sphenoid, pituitary sella, and suprasellar regions were performed on one cadaver and one live mongrel dog. Both the cadaver and canine procedures were performed in an approved training facility using the da Vinci Surgical Robot. For the canine experiments, a transoral robotic surgery (TORS) approach was used, and for the cadaver a newly developed combined cervical-transoral robotic surgery (C-TORS) approach wasmore » investigated and compared with standard TORS. The ability to access and dissect tissues within the various areas of the midline and anterior skull base were evaluated, and techniques to enhance visualization and instrumentation were developed. Results: Standard TORS approaches did not provide adequate access to the midline and anterior skull base; however, the newly developed C-TORS approach was successful in providing the surgical access to these regions of the skull base. Conclusion: Robotic surgery is an exciting minimally invasive approach to the skull base that warrants continued preclinical investigation and development.« less

Developing a musculoskeletal model of the primate skull: predicting muscle activations, bite force, and joint reaction forces using multibody dynamics analysis and advanced optimisation methods.

PubMed

Shi, Junfen; Curtis, Neil; Fitton, Laura C; O'Higgins, Paul; Fagan, Michael J

2012-10-07

An accurate, dynamic, functional model of the skull that can be used to predict muscle forces, bite forces, and joint reaction forces would have many uses across a broad range of disciplines. One major issue however with musculoskeletal analyses is that of muscle activation pattern indeterminacy. A very large number of possible muscle force combinations will satisfy a particular functional task. This makes predicting physiological muscle recruitment patterns difficult. Here we describe in detail the process of development of a complex multibody computer model of a primate skull (Macaca fascicularis), that aims to predict muscle recruitment patterns during biting. Using optimisation criteria based on minimisation of muscle stress we predict working to balancing side muscle force ratios, peak bite forces, and joint reaction forces during unilateral biting. Validation of such models is problematic; however we have shown comparable working to balancing muscle activity and TMJ reaction ratios during biting to those observed in vivo and that peak predicted bite forces compare well to published experimental data. To our knowledge the complexity of the musculoskeletal model is greater than any previously reported for a primate. This complexity, when compared to more simple representations provides more nuanced insights into the functioning of masticatory muscles. Thus, we have shown muscle activity to vary throughout individual muscle groups, which enables them to function optimally during specific masticatory tasks. This model will be utilised in future studies into the functioning of the masticatory apparatus. Copyright © 2012 Elsevier Ltd. All rights reserved.

Facial artery musculomucosal flap for reconstruction of skull base defects: a cadaveric study.

PubMed

Xie, Liyue; Lavigne, François; Rahal, Akram; Moubayed, Sami Pierre; Ayad, Tareck

2013-08-01

Failure in skull base defects reconstruction following tumor resection can have serious consequences such as ascending meningitis and pneumocephaly. The nasoseptal flap showed a very low incidence of cerebrospinal fluid leak but is not always available. The superiorly pedicled facial artery musculomucosal (FAMM) flap has been successfully used for reconstruction of head and neck defects. Our objective is to show that the FAMM flap can be used as a new alternative in skull base reconstruction. Cadaveric study. Feasibility. Thirteen specimens underwent bilateral FAMM flap dissection. Two new modifications of the traditional FAMM flap have been developed. Feasibility in FAMM flap transfer to the skull base was investigated through endoscopic skull base dissection and maxillectomy in four specimens. Measurements were recorded for each harvested flap. The mean surface area of the modified FAMM flap efficient for reconstruction was 15.90 cm(2) . The flaps easily covered the simulated defects of the frontal sinus and the fovea ethmoidalis areas. Modifications of the traditional FAMM flap were necessary for a tension-free coverage of the planum sphenoidale and sella turcica. The FAMM flap holds high potential as a new alternative vascular flap in skull base reconstruction. However, it has not been used in patients yet and should be considered only when other options are not available. New modifications developed in this article can elongate the traditional FAMM flap, potentially contributing to a tighter seal of the skull base defect than FAMM flap alone. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

3D printing and intraoperative neuronavigation tailoring for skull base reconstruction after extended endoscopic endonasal surgery: proof of concept.

PubMed

Essayed, Walid I; Unadkat, Prashin; Hosny, Ahmed; Frisken, Sarah; Rassi, Marcio S; Mukundan, Srinivasan; Weaver, James C; Al-Mefty, Ossama; Golby, Alexandra J; Dunn, Ian F

2018-03-02

OBJECTIVE Endoscopic endonasal approaches are increasingly performed for the surgical treatment of multiple skull base pathologies. Preventing postoperative CSF leaks remains a major challenge, particularly in extended approaches. In this study, the authors assessed the potential use of modern multimaterial 3D printing and neuronavigation to help model these extended defects and develop specifically tailored prostheses for reconstructive purposes. METHODS Extended endoscopic endonasal skull base approaches were performed on 3 human cadaveric heads. Preprocedure and intraprocedure CT scans were completed and were used to segment and design extended and tailored skull base models. Multimaterial models with different core/edge interfaces were 3D printed for implantation trials. A novel application of the intraoperative landmark acquisition method was used to transfer the navigation, helping to tailor the extended models. RESULTS Prostheses were created based on preoperative and intraoperative CT scans. The navigation transfer offered sufficiently accurate data to tailor the preprinted extended skull base defect prostheses. Successful implantation of the skull base prostheses was achieved in all specimens. The progressive flexibility gradient of the models' edges offered the best compromise for easy intranasal maneuverability, anchoring, and structural stability. Prostheses printed based on intraprocedure CT scans were accurate in shape but slightly undersized. CONCLUSIONS Preoperative 3D printing of patient-specific skull base models is achievable for extended endoscopic endonasal surgery. The careful spatial modeling and the use of a flexibility gradient in the design helped achieve the most stable reconstruction. Neuronavigation can help tailor preprinted prostheses.

Relationship between the cranial base and the mandible in artificially deformed skulls.

PubMed

Ferros, I; Mora, M J; Obeso, I F; Jimenez, P; Martinez-Insua, A

2016-11-01

There is controversy regarding the relationship between mandibular position and alterations of the cranial base that provoke a more anterior location of the glenoid fossa. Artificially deformed skulls display marked alterations of the cranial base. This study evaluates mandibular changes as function of the morphology of the cranial base in these skulls. A geometric morphometric study was performed on lateral cephalometric X-rays of three groups of skulls: 32 with anteroposterior deformity, 17 with circumferential deformity and 39 with no apparent deformity. In artificially deformed skulls, the cranial base was deformed causing the mandibular condyle to be in a more anterior position. There was a complete remodelling of the mandible involving narrowing and elongation of the mandibular ramus, rotation of the corpus of the mandible and increased vertical height of the symphysis. Forward displacement did not occur. Integration between mandible and cranial base is not altered by deformation of the skull. Deformity of the cranial vault exerts an influence on the mandible, supporting the theory of modular units in complete integration. This also supports the theory that mandibular prognathism is a multifactorial result and not a direct effect of displacement of the cranial base. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Skull of Phyllomedusa sauvagii (Anura, Hylidae).

PubMed

Ruiz-Monachesi, Mario R; Lavilla, Esteban O; Montero, Ricardo

2016-05-01

The hylid genus Phyllomedusa comprises charismatic frogs commonly known as monkey, leaf or green frogs, and is the most diverse genus of the subfamily Phyllomedusinae, including about 31 species. Although there is some information about the anatomy of these frogs, little is known about the osteology. Here the adult skull of Phyllomedusa sauvagii, both articulated and disarticulated, is described and the intraspecific variation is reported. Additionally, cartilage associated with the adult skull, such as the nasal capsules, auditory apparatus, and hyobranchial apparatus, are included in the analysis. Further examination of disarticulated bones reveals their remarkable complexity, specifically in the sphenethmoid and of the oocipital region. The description of disarticulated bones is useful for the identification of fossil remains as well as providing morphological characteristics that are phylogenetically informative. When comparing the skull morphology with the available information of other species of the genus, Phyllomesusa sauvagii skull resembles more that of P. vaillantii and P. venusta than P. atelopoides. © 2016 Wiley Periodicals, Inc.

Low-grade fibrosarcoma of the anterior skull base: endoscopic resection and repair.

PubMed

Kuhn, Frederick A; Javer, Amin R

2003-01-01

Fibrosarcomas of the paranasal sinuses and skull base are uncommon tumors. Traditionally, "open approach" surgery remains the mainstay for treatment of choice for these tumors. A 49-year-old man underwent resection of a right anterior skull base fibrosarcoma using the endoscopic approach. Close follow-up using both endoscopic and imaging methods over a period of four years has revealed a well-healed skull base with no evidence of recurrence. Significant resistance exists at present for such a technique to deal with malignant diseases of the head and neck but results from advanced centers continue to prove that this may be a technique worth mastering and improving on.

Dimensional, Geometrical, and Physical Constraints in Skull Growth.

PubMed

Weickenmeier, Johannes; Fischer, Cedric; Carter, Dennis; Kuhl, Ellen; Goriely, Alain

2017-06-16

After birth, the skull grows and remodels in close synchrony with the brain to allow for an increase in intracranial volume. Increase in skull area is provided primarily by bone accretion at the sutures. Additional remodeling, to allow for a change in curvatures, occurs by resorption on the inner surface of the bone plates and accretion on their outer surfaces. When a suture fuses too early, normal skull growth is disrupted, leading to a deformed final skull shape. The leading theory assumes that the main stimulus for skull growth is provided by mechanical stresses. Based on these ideas, we first discuss the dimensional, geometrical, and kinematic synchrony between brain, skull, and suture growth. Second, we present two mechanical models for skull growth that account for growth at the sutures and explain the various observed dysmorphologies. These models demonstrate the particular role of physical and geometrical constraints taking place in skull growth.

Dimensional, Geometrical, and Physical Constraints in Skull Growth

NASA Astrophysics Data System (ADS)

Weickenmeier, Johannes; Fischer, Cedric; Carter, Dennis; Kuhl, Ellen; Goriely, Alain

2017-06-01

After birth, the skull grows and remodels in close synchrony with the brain to allow for an increase in intracranial volume. Increase in skull area is provided primarily by bone accretion at the sutures. Additional remodeling, to allow for a change in curvatures, occurs by resorption on the inner surface of the bone plates and accretion on their outer surfaces. When a suture fuses too early, normal skull growth is disrupted, leading to a deformed final skull shape. The leading theory assumes that the main stimulus for skull growth is provided by mechanical stresses. Based on these ideas, we first discuss the dimensional, geometrical, and kinematic synchrony between brain, skull, and suture growth. Second, we present two mechanical models for skull growth that account for growth at the sutures and explain the various observed dysmorphologies. These models demonstrate the particular role of physical and geometrical constraints taking place in skull growth.

Meckel's cave access: anatomic study comparing the endoscopic transantral and endonasal approaches.

PubMed

Van Rompaey, Jason; Suruliraj, Anand; Carrau, Ricardo; Panizza, Benedict; Solares, C Arturo

2014-04-01

Recent advances in endonasal endoscopy have facilitated the surgical access to the lateral skull base including areas such as Meckel's cave. This approach has been well documented, however, few studies have outlined transantral specific access to Meckel's. A transantral approach provides a direct pathway to this region obviating the need for extensive endonasal and transsphenoidal resection. Our aim in this study is to compare the anatomical perspectives obtained in endonasal and transantral approaches. We prepared 14 cadaveric specimens with intravascular injections of colored latex. Eight cadavers underwent endoscopic endonasal transpterygoid approaches to Meckel's cave. Six additional specimens underwent an endoscopic transantral approach to the same region. Photographic evidence was obtained for review. 30 CT scans were analyzed to measure comparative distances to Meckel's cave for both approaches. The endoscopic approaches provided a direct access to the anterior and inferior portions of Meckel's cave. However, the transantral approach required shorter instrumentation, and did not require clearing of the endonasal corridor. This approach gave an anterior view of Meckel's cave making posterior dissection more difficult. A transantral approach to Meckel's cave provides access similar to the endonasal approach with minimal invasiveness. Some of the morbidity associated with extensive endonasal resection could possibly be avoided. Better understanding of the complex skull base anatomy, from different perspectives, helps to improve current endoscopic skull base surgery and to develop new alternatives, consequently, leading to improvements in safety and efficacy.

Skull base tumors: a kaleidoscope of challenge.

PubMed

Khanna, J N; Natrajan, Srivalli; Galinde, Jyotsna

2014-08-01

Resection of skull base lesions has always been riddled with problems like inadequate access, proximity to major vessels, dural tears, cranial nerve damage, and infection. Understanding the modular concept of the facial skeleton has led to the development of transfacial swing osteotomies that facilitates resection in a difficult area with minimal morbidity and excellent cosmetic results. In spite of the current trend toward endonasal endoscopic management of skull base tumors, our series presents nine cases of diverse extensive skull base lesions, 33% of which were recurrent. These cases were approached through different transfacial swing osteotomies through the mandible, a midfacial swing, or a zygomaticotemporal osteotomy as dictated by the three-dimensional spatial location of the lesion, and its extent and proximity to vital structures. Access osteotomies ensured complete removal and good results through the most direct and safe route and good vascular control. This reiterated the fact that transfacial approaches still hold a special place in the management of extensive skull base lesions.

Skull Base Tumors: A Kaleidoscope of Challenge

PubMed Central

Khanna, J.N.; Natrajan, Srivalli; Galinde, Jyotsna

2014-01-01

Resection of skull base lesions has always been riddled with problems like inadequate access, proximity to major vessels, dural tears, cranial nerve damage, and infection. Understanding the modular concept of the facial skeleton has led to the development of transfacial swing osteotomies that facilitates resection in a difficult area with minimal morbidity and excellent cosmetic results. In spite of the current trend toward endonasal endoscopic management of skull base tumors, our series presents nine cases of diverse extensive skull base lesions, 33% of which were recurrent. These cases were approached through different transfacial swing osteotomies through the mandible, a midfacial swing, or a zygomaticotemporal osteotomy as dictated by the three-dimensional spatial location of the lesion, and its extent and proximity to vital structures. Access osteotomies ensured complete removal and good results through the most direct and safe route and good vascular control. This reiterated the fact that transfacial approaches still hold a special place in the management of extensive skull base lesions. PMID:25083368

Microsurgical management of basilar artery apex aneurysms: a single surgeon's experience from Louisiana State University, Shreveport.

PubMed

Nanda, Anil; Sonig, Ashish; Banerjee, Anirban Deep; Javalkar, Vijay Kumar

2014-01-01

Basilar artery apex aneurysms continue to generate technical challenges and management controversy. Endovascular intervention is becoming the mainstay in the management of these formidable aneurysms, but it has limitations, especially with large/giant or wide neck basilar apex aneurysms. There is paucity of data in the available literature pertaining to the successful management of large/giant, wide neck, and calcified/thrombosed basilar apex aneurysms. We present our experience with consecutively operated complex basilar apex aneurysms so as to present the role of microneurosurgery as a viable management option for these aneurysms. Ours is a retrospective analysis of case-records for operated cases of basilar artery aneurysms spanning 18 years. Basilar apex aneurysms >10 cm, calcified or thrombosed, neck ≥4 mm posterior direction, and retro/subsellar were considered as complex anatomy aneurysms. Basilar apex aneurysms with favorable anatomy were included in the study as a reference group for statistical analysis. Patient demographics, complex features of aneurysms, clinical grade, and outcomes were analyzed. A total of 33 (53.2%) patients had complex anatomy: large (>10 mm) in eight (24.2%); giant aneurysms (>25 mm) in seven (21.2%); wide-neck in 22 (66.7%); and calcified/thrombosed morphology in five (15.1%). The mean age was 48.5 years, and 22 (66.67%) were women. All aneurysms were clipped by the use of various skull base approaches. A total of 71.9% of patients harboring complex aneurysm had good outcomes. If only unruptured and good grade complex aneurysms also are considered, then 86.9% (n = 20) patients had good outcomes. Statistically there was no significant difference in the outcomes of complex and noncomplex aneurysm. Although concerning, the management of large/giant, wide neck, and calcified/thrombosed aneurysms with microneurosurgery is still a competitive alternative to endovascular therapy. After careful selection of appropriate skull base approaches based on the complexity of the basilar apex aneurysm, microneurosurgery can achieve acceptable results. Copyright © 2014 Elsevier Inc. All rights reserved.

A symbolic shaped-based retrieval of skull images.

PubMed

Lin, H Jill; Ruiz-Correa, Salvador; Shapiro, Linda G; Cunningham, Michael L; Sze, Raymond W

2005-01-01

In this work, we describe a novel symbolic representation of shapes for quantifying skull abnormalities in children with craniosynostosis. We show the efficacy of our work by demonstrating an application of this representation in shape-based retrieval of skull morphologies. This tool will enable correlation with potential pathogenesis and prognosis in order to enhance medical care.

Skull base erosion and associated complications in sphenoid sinus fungal balls

PubMed Central

Meier, Josh C.; Remenschneider, Aaron K.; Sadow, Peter; Chambers, Kyle; Dedmon, Matt; Lin, Derrick T.; Holbrook, Eric H.; Metson, Ralph; Gray, Stacey T.

2016-01-01

Background: Sphenoid sinus fungal balls (SSFB) are rare entities that can result in serious orbital and intracranial complications. There are few published reports of complications that result from SSFB. Objective: To review the incidence of skull base erosion and orbital or intracranial complications in patients who present with SSFB. Methods: A retrospective review was performed of all the patients with SSFB who were treated at the Massachusetts Eye and Ear Infirmary from 2006 to 2014. Presenting clinical data, radiology, operative reports, pathology, and postoperative course were reviewed. Results: Forty-three patients with SSFB were identified. Demographic data were compared between patients with (39.5%) and those without (61.5%) skull base erosion. Two patients underwent emergent surgery for acute complications of SSFB (one patient with blindness, one patient who had a seizure). Both patients with acute complications had evidence of skull base erosion, whereas no patients with an intact skull base developed an orbital or intracranial complication (p = 0.15). All the patients were surgically managed via an endoscopic approach. Conclusion: SSFBs are rare but may cause significant skull base erosion and potentially severe orbital and intracranial complications if not treated appropriately. Endoscopic sphenoidotomy is effective in treating SSFB and should be performed emergently in patients who presented with associated complications. PMID:28683250

In vivo characterization of 3D skull and brain motion during dynamic head vibration using magnetic resonance elastography.

PubMed

Yin, Ziying; Sui, Yi; Trzasko, Joshua D; Rossman, Phillip J; Manduca, Armando; Ehman, Richard L; Huston, John

2018-05-17

To introduce newly developed MR elastography (MRE)-based dual-saturation imaging and dual-sensitivity motion encoding schemes to directly measure in vivo skull-brain motion, and to study the skull-brain coupling in volunteers with these approaches. Six volunteers were scanned with a high-performance compact 3T-MRI scanner. The skull-brain MRE images were obtained with a dual-saturation imaging where the skull and brain motion were acquired with fat- and water-suppression scans, respectively. A dual-sensitivity motion encoding scheme was applied to estimate the heavily wrapped phase in skull by the simultaneous acquisition of both low- and high-sensitivity phase during a single MRE exam. The low-sensitivity phase was used to guide unwrapping of the high-sensitivity phase. The amplitude and temporal phase delay of the rigid-body motion between the skull and brain was measured, and the skull-brain interface was visualized by slip interface imaging (SII). Both skull and brain motion can be successfully acquired and unwrapped. The skull-brain motion analysis demonstrated the motion transmission from the skull to the brain is attenuated in amplitude and delayed. However, this attenuation (%) and delay (rad) were considerably greater with rotation (59 ± 7%, 0.68 ± 0.14 rad) than with translation (92 ± 5%, 0.04 ± 0.02 rad). With SII the skull-brain slip interface was not completely evident, and the slip pattern was spatially heterogeneous. This study provides a framework for acquiring in vivo voxel-based skull and brain displacement using MRE that can be used to characterize the skull-brain coupling system for understanding of mechanical brain protection mechanisms, which has potential to facilitate risk management for future injury. © 2018 International Society for Magnetic Resonance in Medicine.

Image guidance systems for minimally invasive sinus and skull base surgery in children.

PubMed

Benoit, Margo McKenna; Silvera, V Michelle; Nichollas, Richard; Jones, Dwight; McGill, Trevor; Rahbar, Reza

2009-10-01

The use of image guidance for sinonasal and skull base surgery has been well-characterized in adults but there is limited information on the use of these systems in the pediatric population, despite their widespread use. The aim of this study is to evaluate the use of image guidance systems to facilitate an endoscopic minimally invasive approach to sinonasal and skull base surgery in a pediatric population. A retrospective cohort study was performed at a tertiary pediatric hospital. Thirty-three children presented with complications of sinusitis, tumors, traumatic, or congenital lesions of the skull base and underwent endoscopic surgery using image guidance from March 2000 to April 2007. Patient variables including diagnosis, extent of disease, and complications were extracted from paper and computer charts. Additional surgical variables including set-up time, accuracy, surgeon satisfaction index and number of uses per case were also reviewed. Twenty-eight patients (85%) underwent sinonasal surgery and five (15%) underwent skull base surgery. Indications included infectious complications of acute sinusitis (N=15), neoplasms (N=12), choanal atresia (N=4), and cerebrospinal fluid leak (N=2). Thirty-one patients (94%) required only one procedure. No surgical complications were reported. Surgeon satisfaction, mean accuracy and number of uses per procedure increased over time (p<0.05). Image guidance systems are safe and effective tools that facilitate a minimally invasive approach to sinonasal and skull base surgery in children. Consistent with adult literature, usage and surgeon comfort increased with experience. The additional anatomical information obtained by image guidance systems facilitates a minimally invasive endoscopic approach for sinonasal and skull base pathologies.

Sinus anatomy associated with inadvertent cerebrospinal fluid leak during functional endoscopic sinus surgery.

PubMed

Heaton, Chase M; Goldberg, Andrew N; Pletcher, Steven D; Glastonbury, Christine M

2012-07-01

Anatomic variations in skull base anatomy may predispose the surgeon to inadvertent skull base injury with resultant cerebrospinal fluid (CSF) leak during functional endoscopic sinus surgery (ESS). Our objective was to compare preoperative sinus imaging of patients who underwent FESS with and without CSF leak to elucidate these variations. In this retrospective case-control study, 18 patients with CSF leak following FESS for chronic rhinosinusitis (CRS) from 2000 to 2011 were compared to 18 randomly selected patients who underwent preoperative imaging for FESS for CRS. Measurements were obtained from preoperative computed tomography images with specific attention to anatomic differences in cribriform plate and ethmoid roof heights in the coronal plane, and the skull base angle in the sagittal plane. Mean values of measured variables were compared using a nonparametric Mann-Whitney test. When compared to controls, patients with CSF leak demonstrated a greater angle of the skull base in the sagittal plane (P < .001) and a greater slope of the skull base in the coronal plane (P < .006). A lower cribriform height relative to ethmoid roof height was also noted in cases of CSF leak as compared to controls (P < .04). A steep skull base angle in the sagittal plane, a greater slope of the skull base in the coronal plane, and a low cribriform height relative to the ethmoid roof predispose the patient to CSF leak during FESS. Preoperative review of imaging with specific attention paid to these anatomic variations may help to prevent iatrogenic CSF leak. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Preformed titanium cranioplasty after resection of skull base meningiomas - a technical note.

PubMed

Schebesch, Karl-Michael; Höhne, Julius; Gassner, Holger G; Brawanski, Alexander

2013-12-01

Meningiomas of the fronto-basal skull are difficult to manage as the treatment usually includes extensive resection of the lesion, consecutive reconstruction of the meninges and of the skull. Especially after removal of spheno-orbital and sphenoid-wing meningiomas, the cosmetic result is of utmost importance. In this technical note, we present our institutional approach in the treatment of skull base meningiomas, focussing on the reconstruction of the neurocranium with individually preformed titanium cranioplasty (CRANIOTOP(®), CL Instruments, Germany). Two female patients (40 years, 64 years) are presented. Both patients presented with skull base lesions suggestive of meningiomas. The preoperative thin-sliced CT scan was processed to generate a 3D-model of the skull. On it, the resection was mapped and following a simulated resection, the cranioplasty was manufactured. Intra-operatively, the titanium plate served as a template for the skull resection and was implanted after microsurgical tumour removal, consecutively. The cosmetic result was excellent. Immediate postoperative CT scan revealed accurate fitting and complete tumour removal. Control Magnetic Resonance Imaging (MRI) within 12 weeks was possible without any artifacts. The comprehensive approach described indicates only one surgical procedure for tumour removal and for reconstruction of the skull. The titanium plate served as an exact template for complete resection of the osseous parts of the tumour. Cosmetic outcome was excellent and control MRI was possible post operatively. CRANIOTOP(®) cranioplasty is a safe and practical tool for reconstruction of the skull after meningioma surgery. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Endonasal Skull Base Tumor Removal Using Concentric Tube Continuum Robots: A Phantom Study.

PubMed

Swaney, Philip J; Gilbert, Hunter B; Webster, Robert J; Russell, Paul T; Weaver, Kyle D

2015-03-01

Objectives The purpose of this study is to experimentally evaluate the use of concentric tube continuum robots in endonasal skull base tumor removal. This new type of surgical robot offers many advantages over existing straight and rigid surgical tools including added dexterity, the ability to scale movements, and the ability to rotate the end effector while leaving the robot fixed in space. In this study, a concentric tube continuum robot was used to remove simulated pituitary tumors from a skull phantom. Design The robot was teleoperated by experienced skull base surgeons to remove a phantom pituitary tumor within a skull. Percentage resection was measured by weight. Resection duration was timed. Setting Academic research laboratory. Main Outcome Measures Percentage removal of tumor material and procedure duration. Results Average removal percentage of 79.8 ± 5.9% and average time to complete procedure of 12.5 ± 4.1 minutes (n = 20). Conclusions The robotic system presented here for use in endonasal skull base surgery shows promise in improving the dexterity, tool motion, and end effector capabilities currently available with straight and rigid tools while remaining an effective tool for resecting the tumor.

Construction and validation of the midsagittal reference plane based on the skull base symmetry for three-dimensional cephalometric craniofacial analysis.

PubMed

Kim, Hak-Jin; Kim, Bong Chul; Kim, Jin-Geun; Zhengguo, Piao; Kang, Sang Hoon; Lee, Sang-Hwy

2014-03-01

The objective of this study was to determine the reliable midsagittal (MS) reference plane in practical ways for the three-dimensional craniofacial analysis on three-dimensional computed tomography images. Five normal human dry skulls and 20 normal subjects without any dysmorphoses or asymmetries were used. The accuracies and stability on repeated plane construction for almost every possible candidate MS plane based on the skull base structures were examined by comparing the discrepancies in distances and orientations from the reference points and planes of the skull base and facial bones on three-dimensional computed tomography images. The following reference points of these planes were stable, and their distribution was balanced: nasion and foramen cecum at the anterior part of the skull base, sella at the middle part, and basion and opisthion at the posterior part. The candidate reference planes constructed using the aforementioned reference points were thought to be reliable for use as an MS reference plane for the three-dimensional analysis of maxillofacial dysmorphosis.

Use of a 3D Skull Model to Improve Accuracy in Cranioplasty for Autologous Flap Resorption in a 3-Year-Old Child.

PubMed

Maduri, Rodolfo; Viaroli, Edoardo; Levivier, Marc; Daniel, Roy T; Messerer, Mahmoud

2017-01-01

Cranioplasty is considered a simple reconstructive procedure, usually performed in a single stage. In some clinical conditions, such as in children with multifocal flap osteolysis, it could represent a surgical challenge. In these patients, the partially resorbed autologous flap should be removed and replaced with a precustomed prosthesis which should perfectly match the expected bone defect. We describe the technique used for a navigated cranioplasty in a 3-year-old child with multifocal autologous flap osteolysis. We decided to perform a cranioplasty using a custom-made hydroxyapatite porous ceramic flap. The prosthesis was produced with an epoxy resin 3D skull model of the patient, which included a removable flap corresponding to the planned cranioplasty. Preoperatively, a CT scan of the 3D skull model was performed without the removable flap. The CT scan images of the 3D skull model were merged with the preoperative 3D CT scan of the patient and navigated during the cranioplasty to define with precision the cranioplasty margins. After removal of the autologous resorbed flap, the hydroxyapatite prosthesis matched perfectly with the skull defect. The anatomical result was excellent. Thus, the implementation of cranioplasty with image merge navigation of a 3D skull model may improve cranioplasty accuracy, allowing precise anatomic reconstruction in complex skull defect cases. © 2017 S. Karger AG, Basel.

The ‘Unicorn’ Dinosaur That Wasn’t: A New Reconstruction of the Crest of Tsintaosaurus and the Early Evolution of the Lambeosaurine Crest and Rostrum

PubMed Central

Prieto-Márquez, Albert; Wagner, Jonathan R.

2013-01-01

The lambeosaurine Tsintaosaurus spinorhinus has traditionally been reconstructed with an elevated, hollow, spike-like crest composed entirely of the nasal bones, although this has been disputed. Here, we provide a new reconstruction of the skull of this species based on reexamination and reinterpretation of the morphology and articular relationships of the type and Paratype skulls and a fragmentary crest. We confirm the presence of a supracranial crest composed of the elevated nasal bones, but also including the premaxillae. We hypothesize that the crest is a tall, lobate, hollow structure that projects dorsally and slightly caudally a distance greater than the height of the skull along the quadrate. In our reconstruction, the nasal passage passes through the crest, but enters the skull rostral to the tubular process of the nasals, not through it. Tsintaosaurus spinorhinus is rediagnosed on the basis of a suite of cranial autapomorphies including a circumnarial fossa subdivided into three accessory fossae, prefrontal with ascending rostral process and lateral flange, nasals fused sagittally to form elongate tubular process that rises dorsally from skull roof, each nasal being expanded rostrocaudally into a rhomboid distal process, and medial processes of premaxillae at the summit of the cranial crest inserted between rhomboid processes of nasals. Tsintaosaurus spinorhinus lacks characters that are present in more derived lambeosaurines (parasaurolophins and lambeosaurins), such as rotation of the caudal margin of the crest to an acute angle with the skull roof, lateral processes of the nasals that enclose part of the intracranial cavity and participate in the formation of the walls of the common median chamber, and a smooth narial fossa lacking ridges and accessory fossae. We hypothesize that ancestrally the rostrum of lambeosaurines may have been more similar to that in Saurolophinae, and became subsequently reduced in complexity during evolution of the group. PMID:24278478

The 'Unicorn' dinosaur that wasn't: a new reconstruction of the crest of Tsintaosaurus and the early evolution of the lambeosaurine crest and rostrum.

PubMed

Prieto-Márquez, Albert; Wagner, Jonathan R

2013-01-01

The lambeosaurine Tsintaosaurus spinorhinus has traditionally been reconstructed with an elevated, hollow, spike-like crest composed entirely of the nasal bones, although this has been disputed. Here, we provide a new reconstruction of the skull of this species based on reexamination and reinterpretation of the morphology and articular relationships of the type and Paratype skulls and a fragmentary crest. We confirm the presence of a supracranial crest composed of the elevated nasal bones, but also including the premaxillae. We hypothesize that the crest is a tall, lobate, hollow structure that projects dorsally and slightly caudally a distance greater than the height of the skull along the quadrate. In our reconstruction, the nasal passage passes through the crest, but enters the skull rostral to the tubular process of the nasals, not through it. Tsintaosaurus spinorhinus is rediagnosed on the basis of a suite of cranial autapomorphies including a circumnarial fossa subdivided into three accessory fossae, prefrontal with ascending rostral process and lateral flange, nasals fused sagittally to form elongate tubular process that rises dorsally from skull roof, each nasal being expanded rostrocaudally into a rhomboid distal process, and medial processes of premaxillae at the summit of the cranial crest inserted between rhomboid processes of nasals. Tsintaosaurus spinorhinus lacks characters that are present in more derived lambeosaurines (parasaurolophins and lambeosaurins), such as rotation of the caudal margin of the crest to an acute angle with the skull roof, lateral processes of the nasals that enclose part of the intracranial cavity and participate in the formation of the walls of the common median chamber, and a smooth narial fossa lacking ridges and accessory fossae. We hypothesize that ancestrally the rostrum of lambeosaurines may have been more similar to that in Saurolophinae, and became subsequently reduced in complexity during evolution of the group.

Modeling skull's acoustic attenuation and dispersion on photoacoustic signal

NASA Astrophysics Data System (ADS)

Mohammadi, L.; Behnam, H.; Nasiriavanaki, M. R.

2017-03-01

Despite the great promising results of a recent new transcranial photoacoustic brain imaging technology, it has been shown that the presence of the skull severely affects the performance of this imaging modality. In this paper, we investigate the effect of skull on generated photoacoustic signals with a mathematical model. The developed model takes into account the frequency dependence attenuation and acoustic dispersion effects occur with the wave reflection and refraction at the skull surface. Numerical simulations based on the developed model are performed for calculating the propagation of photoacoustic waves through the skull. From the simulation results, it was found that the skull-induced distortion becomes very important and the reconstructed image would be strongly distorted without correcting these effects. In this regard, it is anticipated that an accurate quantification and modeling of the skull transmission effects would ultimately allow for skull aberration correction in transcranial photoacoustic brain imaging.

Role of preoperative 3-dimensional computed tomography reconstruction in depressed skull fractures treated with craniectomy: a case report of forensic interest.

PubMed

Viel, Guido; Cecchetto, Giovanni; Manara, Renzo; Cecchetto, Attilio; Montisci, Massimo

2011-06-01

Patients affected by cranial trauma with depressed skull fractures and increased intracranial pressure generally undergo neurosurgical intervention. Because craniotomy and craniectomy remove skull fragments and generate new fracture lines, they complicate forensic examination and sometimes prevent a clear identification of skull fracture etiology. A 3-dimensional reconstruction based on preoperative computed tomography (CT) scans, giving a picture of the injuries before surgical intervention, can help the forensic examiner in identifying skull fracture origin and the means of production.We report the case of a 41-year-old-man presenting at the emergency department with a depressed skull fracture at the vertex and bilateral subdural hemorrhage. The patient underwent 2 neurosurgical interventions (craniotomy and craniectomy) but died after 40 days of hospitalization in an intensive care unit. At autopsy, the absence of various bone fragments did not allow us to establish if the skull had been stricken by a blunt object or had hit the ground with high kinetic energy. To analyze bone injuries before craniectomy, a 3-dimensional CT reconstruction based on preoperative scans was performed. A comparative analysis between autoptic and radiological data allowed us to differentiate surgical from traumatic injuries. Moreover, based on the shape and size of the depressed skull fracture (measured from the CT reformations), we inferred that the man had been stricken by a cylindric blunt object with a diameter of about 3 cm.

Virtual surgical planning in endoscopic skull base surgery.

PubMed

Haerle, Stephan K; Daly, Michael J; Chan, Harley H L; Vescan, Allan; Kucharczyk, Walter; Irish, Jonathan C

2013-12-01

Skull base surgery (SBS) involves operative tasks in close proximity to critical structures in a complex three-dimensional (3D) anatomy. The aim was to investigate the value of virtual planning (VP) based on preoperative magnetic resonance imaging (MRI) for surgical planning in SBS and to compare the effects of virtual planning with 3D contours between the expert and the surgeon in training. Retrospective analysis. Twelve patients with manually segmented anatomical structures based on preoperative MRI were evaluated by eight surgeons in a randomized order using a validated National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire. Multivariate analysis revealed significant reduction of workload when using VP (P<.0001) compared to standard planning. Further, it showed that the experience level of the surgeon had a significant effect on the NASA-TLX differences (P<.05). Additional subanalysis did not reveal any significant findings regarding which type of surgeon benefits the most (P>.05). Preoperative anatomical segmentation with virtual surgical planning using contours in endoscopic SBS significantly reduces the workload for the expert and the surgeon in training. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Endoscopic endonasal double flap technique for reconstruction of large anterior skull base defects: technical note.

PubMed

Dolci, Ricardo Landini Lutaif; Todeschini, Alexandre Bossi; Santos, Américo Rubens Leite Dos; Lazarini, Paulo Roberto

2018-04-19

One of the main concerns in endoscopic endonasal approaches to the skull base has been the high incidence and morbidity associated with cerebrospinal fluid leaks. The introduction and routine use of vascularized flaps allowed a marked decrease in this complication followed by a great expansion in the indications and techniques used in endoscopic endonasal approaches, extending to defects from huge tumours and previously inaccessible areas of the skull base. Describe the technique of performing endoscopic double flap multi-layered reconstruction of the anterior skull base without craniotomy. Step by step description of the endoscopic double flap technique (nasoseptal and pericranial vascularized flaps and fascia lata free graft) as used and illustrated in two patients with an olfactory groove meningioma who underwent an endoscopic approach. Both patients achieved a gross total resection: subsequent reconstruction of the anterior skull base was performed with the nasoseptal and pericranial flaps onlay and a fascia lata free graft inlay. Both patients showed an excellent recovery, no signs of cerebrospinal fluid leak, meningitis, flap necrosis, chronic meningeal or sinonasal inflammation or cerebral herniation having developed. This endoscopic double flap technique we have described is a viable, versatile and safe option for anterior skull base reconstructions, decreasing the incidence of complications in endoscopic endonasal approaches. Copyright © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Comparison of CT and MRI in diagnosis of cerebrospinal leak induced by multiple fractures of skull base

PubMed Central

Wang, Xuhui; Xu, Minhui; Liang, Hong; Xu, Lunshan

2011-01-01

Background Multiple basilar skull fracture and cerebrospinal leak are common complications of traumatic brain injury, which required a surgical repair. But due to the complexity of basilar skull fracture after severe trauma, preoperatively an exact radiological location is always difficult. Multi-row spiral CT and MRI are currently widely applied in the clinical diagnosis. The present study was performed to compare the accuracy of cisternography by multi-row spiral CT and MRI in the diagnosis of cerebrospinal leak. Methods A total of 23 patients with multiple basilar skull fracture after traumatic brain injury were included. The radiological and surgical data were retrospectively analyzed. 64-row CT (mm/row) scan and three-dimensional reconstruction were performed in 12 patients, while MR plain scan and cisternography were performed in another 11 patients. The location of cerebrospinal leak was diagnosed by 2 experienced physicians majoring neurological radiology. Surgery was performed in all patients. The cerebrospinal leak location was confirmed and repaired during surgery. The result was considered as accurate when cerebrospinal leak was absent after surgery. Results According to the surgical exploration, the preoperative diagnosis of the active cerebrospinal leak location was accurate in 9 out of 12 patients with CT scan. The location could not be confirmed by CT because of multiple fractures in 2 patients and the missed diagnosis occurred in 1 patient. The preoperative diagnosis was accurate in 10 out of 11 patients with MRI examination. Conclusions MRI cisternography is more advanced than multi-row CT scan in multiple basilar skull fracture. The combination of the two examinations may increase the diagnostic ratio of active cerebrospinal leak. PMID:22933941

Orbital shape in intentional skull deformations and adult sagittal craniosynostoses.

PubMed

Sandy, Ronak; Hennocq, Quentin; Nysjö, Johan; Giran, Guillaume; Friess, Martin; Khonsari, Roman Hossein

2018-06-21

Intentional cranial deformations are the result of external mechanical forces exerted on the skull vault that modify the morphology of various craniofacial structures such as the skull base, the orbits and the zygoma. In this controlled study, we investigated the 3D shape of the orbital inner mould and the orbital volume in various types of intentional deformations and in adult non-operated scaphocephaly - the most common type of craniosynostosis - using dedicated morphometric methods. CT scans were performed on 32 adult skulls with intentional deformations, 21 adult skull with scaphocephaly and 17 non-deformed adult skulls from the collections of the Muséum national d'Histoire naturelle in Paris, France. The intentional deformations group included six skulls with Toulouse deformations, eight skulls with circumferential deformations and 18 skulls with antero-posterior deformations. Mean shape models were generated based on a semi-automatic segmentation technique. Orbits were then aligned and compared qualitatively and quantitatively using colour-coded distance maps and by computing the mean absolute distance, the Hausdorff distance, and the Dice similarity coefficient. Orbital symmetry was assessed after mirroring, superimposition and Dice similarity coefficient computation. We showed that orbital shapes were significantly and symmetrically modified in intentional deformations and scaphocephaly compared with non-deformed control skulls. Antero-posterior and circumferential deformations demonstrated a similar and severe orbital deformation pattern resulting in significant smaller orbital volumes. Scaphocephaly and Toulouse deformations had similar deformation patterns but had no effect on orbital volumes. This study showed that intentional deformations and scaphocephaly significantly interact with orbital growth. Our approach was nevertheless not sufficient to identify specific modifications caused by the different types of skull deformations or by scaphocephaly. © 2018 Anatomical Society.

Finite-element modeling of the human neurocranium under functional anatomical aspects.

PubMed

Mall, G; Hubig, M; Koebke, J; Steinbuch, R

1997-08-01

Due to its functional significance the human skull plays an important role in biomechanical research. The present work describes a new Finite-Element model of the human neurocranium. The dry skull of a middle-aged woman served as a pattern. The model was developed using only the preprocessor (Mentat) of a commercial FE-system (Marc). Unlike that of other FE models of the human skull mentioned in the literature, the geometry in this model was designed according to functional anatomical findings. Functionally important morphological structures representing loci minoris resistentiae, especially the foramina and fissures of the skull base, were included in the model. The results of two linear static loadcase analyses in the region of the skull base underline the importance of modeling from the functional anatomical point of view.

Surgical resection of a huge cemento-ossifying fibroma in skull base by intraoral approach.

PubMed

Cheng, Xiao-Bing; Li, Yun-Peng; Lei, De-Lin; Li, Xiao-Dong; Tian, Lei

2011-03-01

Cemento-ossifying fibroma, also known as ossifying fibroma, usually occurs in the mandible and less commonly in the maxilla. The huge example in the skull base is even rare. We present a case of a huge cemento-ossifying fibroma arising below the skull base of a 30-year-old woman patient. Radiologic investigations showed a giant, lobulated, heterogeneous calcified hard tissue mass, which is well circumscribed and is a mixture of radiolucent and radiopaque, situated at the rear of the right maxilla to the middle skull base. The tumor expands into the right maxillary sinus and the orbital cavity, fusing with the right maxilla at the maxillary tuberosity and blocking the bilateral choanas, which caused marked proptosis and blurred vision. The tumor was resected successfully by intraoral approach, and pathologic examination confirmed the lesion to be a cemento-ossifying fibroma. This case demonstrates that cemento-ossifying fibroma in the maxilla, not like in the mandible, may appear more aggressive because the extensive growth is unimpeded by anatomic obstacles and that the intraoral approach can be used to excise the tumor in the skull base.

Classification of Suncus murinus species complex (Soricidae: Crocidurinae) in Peninsular Malaysia using image analysis and machine learning approaches.

PubMed

Abu, Arpah; Leow, Lee Kien; Ramli, Rosli; Omar, Hasmahzaiti

2016-12-22

Taxonomists frequently identify specimen from various populations based on the morphological characteristics and molecular data. This study looks into another invasive process in identification of house shrew (Suncus murinus) using image analysis and machine learning approaches. Thus, an automated identification system is developed to assist and simplify this task. In this study, seven descriptors namely area, convex area, major axis length, minor axis length, perimeter, equivalent diameter and extent which are based on the shape are used as features to represent digital image of skull that consists of dorsal, lateral and jaw views for each specimen. An Artificial Neural Network (ANN) is used as classifier to classify the skulls of S. murinus based on region (northern and southern populations of Peninsular Malaysia) and sex (adult male and female). Thus, specimen classification using Training data set and identification using Testing data set were performed through two stages of ANNs. At present, the classifier used has achieved an accuracy of 100% based on skulls' views. Classification and identification to regions and sexes have also attained 72.5%, 87.5% and 80.0% of accuracy for dorsal, lateral, and jaw views, respectively. This results show that the shape characteristic features used are substantial because they can differentiate the specimens based on regions and sexes up to the accuracy of 80% and above. Finally, an application was developed and can be used for the scientific community. This automated system demonstrates the practicability of using computer-assisted systems in providing interesting alternative approach for quick and easy identification of unknown species.

Taking a fresh look at the skull base in otorhinolaryngology with web-based simulation: Student's Interactive Skull-Base Trainer (SISTer).

PubMed

von Sass, Peter Freiherr; Scheckenbach, Kathrin; Wagenmann, Martin; Klenzner, Thomas; Schipper, Joerg; Chaker, Adam

2015-02-01

The increasing amount of medical knowledge and necessity for time-effective teaching and learning have given rise to emerging online, or e-learning, applications. The base of the skull is a challenging anatomic area in the otorhinolaryngology (ORL) department-for both students and lecturers. Technology-enhanced learning might be an expedient approach to benefit both learners and lecturers. To investigate and create for advanced medical students a self-assessed adaptive e-learning application for the skull base within our curriculum of otolaryngology at the University Medical Center of Heinrich Heine University, Düsseldorf, Germany. Pilot approach with prospective evaluation of a newly implemented web-based e-learning simulation. The e-learning application (Student's Interactive Skull-Base Trainer) was made accessible as an elective course to a total of 269 enrolled medical students during the first 2 semesters after web launch. Spatiotemporal independent e-learning application for the skull base. Self-assessed evaluation with focus on general acceptance and personal value as well as usage data analysis. The application was well accepted by the learners. More than 80% of the participating students found the application to be a beneficial tool for enhancing their analytical and clinical problem-solving skills. Although the general matter of the skull base seemed to be of lesser interest, the concept of anchored instructions with the use of high-end, interactive, multimedia-based content was considered to be particularly suitable for this challenging topic. Most of the students would have appreciated an extension of optional e-learning modules. With this pilot approach we were able to implement a useful and now well-accepted tool for blended learning. We showed that it is possible to raise interest even in this very specialized subspecialty of ORL with overall individual learning benefit for the students. There is a demand for more e-learning and web-based simulation to support the existing curricula in a hybrid, blended way.

Sinus Anatomy

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Transcranial passive acoustic mapping with hemispherical sparse arrays using CT-based skull-specific aberration corrections: a simulation study

PubMed Central

Jones, Ryan M.; O’Reilly, Meaghan A.; Hynynen, Kullervo

2013-01-01

The feasibility of transcranial passive acoustic mapping with hemispherical sparse arrays (30 cm diameter, 16 to 1372 elements, 2.48 mm receiver diameter) using CT-based aberration corrections was investigated via numerical simulations. A multi-layered ray acoustic transcranial ultrasound propagation model based on CT-derived skull morphology was developed. By incorporating skull-specific aberration corrections into a conventional passive beamforming algorithm (Norton and Won 2000 IEEE Trans. Geosci. Remote Sens. 38 1337–43), simulated acoustic source fields representing the emissions from acoustically-stimulated microbubbles were spatially mapped through three digitized human skulls, with the transskull reconstructions closely matching the water-path control images. Image quality was quantified based on main lobe beamwidths, peak sidelobe ratio, and image signal-to-noise ratio. The effects on the resulting image quality of the source’s emission frequency and location within the skull cavity, the array sparsity and element configuration, the receiver element sensitivity, and the specific skull morphology were all investigated. The system’s resolution capabilities were also estimated for various degrees of array sparsity. Passive imaging of acoustic sources through an intact skull was shown possible with sparse hemispherical imaging arrays. This technique may be useful for the monitoring and control of transcranial focused ultrasound (FUS) treatments, particularly non-thermal, cavitation-mediated applications such as FUS-induced blood-brain barrier disruption or sonothrombolysis, for which no real-time monitoring technique currently exists. PMID:23807573

3D printing and modelling of customized implants and surgical guides for non-human primates.

PubMed

Chen, Xing; Possel, Jessy K; Wacongne, Catherine; van Ham, Anne F; Klink, P Christiaan; Roelfsema, Pieter R

2017-07-15

Primate neurobiologists use chronically implanted devices such as pedestals for head stabilization and chambers to gain access to the brain and study its activity. Such implants are skull-mounted, and made from a hard, durable material, such as titanium. Here, we present a low-cost method of creating customized 3D-printed cranial implants that are tailored to the anatomy of individual animals. We performed pre-surgical computed tomography (CT) and magnetic resonance (MR) scans to generate three-dimensional (3D) models of the skull and brain. We then used 3D modelling software to design implantable head posts, chambers, and a pedestal anchorage base, as well as craniotomy guides to aid us during surgery. Prototypes were made from plastic or resin, while implants were 3D-printed in titanium. The implants underwent post-processing and received a coating of osteocompatible material to promote bone integration. Their tailored fit greatly facilitated surgical implantation, and eliminated the gap between the implant and the bone. To date, our implants remain robust and well-integrated with the skull. Commercial-off-the-shelf solutions typically come with a uniform, flat base, preventing them from sitting flush against the curved surface of the skull. This leaves gaps for fluid and tissue ingress, increasing the risk of microbial infection and tissue inflammation, as well as implant loss. The use of 3D printing technology enabled us to quickly and affordably create unique, complex designs, avoiding the constraints levied by traditional production methods, thereby boosting experimental success and improving the wellbeing of the animals. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Surgical outcomes after reoperation for recurrent skull base meningiomas.

PubMed

Magill, Stephen T; Lee, David S; Yen, Adam J; Lucas, Calixto-Hope G; Raleigh, David R; Aghi, Manish K; Theodosopoulos, Philip V; McDermott, Michael W

2018-05-04

OBJECTIVE Skull base meningiomas are surgically challenging tumors due to the intricate skull base anatomy and the proximity of cranial nerves and critical cerebral vasculature. Many studies have reported outcomes after primary resection of skull base meningiomas; however, little is known about outcomes after reoperation for recurrent skull base meningiomas. Since reoperation is one treatment option for patients with recurrent meningioma, the authors sought to define the risk profile for reoperation of skull base meningiomas. METHODS A retrospective review of 2120 patients who underwent resection of meningiomas between 1985 and 2016 was conducted. Clinical information was extracted from the medical records, radiology data, and pathology data. All records of patients with recurrent skull base meningiomas were reviewed. Demographic data, presenting symptoms, surgical management, outcomes, and complications data were collected. Kaplan-Meier analysis was used to evaluate survival after reoperation. Logistic regression was used to evaluate for risk factors associated with complications. RESULTS Seventy-eight patients underwent 100 reoperations for recurrent skull base meningiomas. Seventeen patients had 2 reoperations, 3 had 3 reoperations, and 2 had 4 or more reoperations. The median age at diagnosis was 52 years, and 64% of patients were female. The median follow-up was 8.5 years. Presenting symptoms included cranial neuropathy, headache, seizure, proptosis, and weakness. The median time from initial resection to first reoperation was 4.4 years and 4.1 years from first to second reoperation. Seventy-two percent of tumors were WHO grade I, 22% were WHO grade II, and 6% were WHO grade III. The sphenoid wing was the most common location (31%), followed by cerebellopontine angle (14%), cavernous sinus (13%), olfactory groove (12%), tuberculum sellae (12%), and middle fossa floor (5%). Forty-four (54%) tumors were ≥ 3 cm in maximum diameter at the time of the first reoperation. In 100 reoperations, 60 complications occurred in 30 cases. Twenty of the 60 complications required surgical intervention (33%). Complications included hydrocephalus (12), CSF leak/pseudomeningocele (11), wound infection (9), postoperative hematoma (4), venous infarction (1), and pneumocephalus (1). Postoperative neurological deficits included new or worsened cranial nerve deficits (10) and hemiparesis (3). There were no perioperative deaths in this series. On multivariate analysis, posterior fossa location was significantly associated with complications (OR 3.45, p = 0.0472). The 1-, 2-, 5-, and 10-year overall survival rates according to Kaplan-Meier analysis after the first reoperation were 94%, 92%, 88%, and 76%, respectively. The median survival after the first reoperation was 17 years. CONCLUSIONS Recurrent skull base meningiomas are surgically challenging tumors, and reoperation is associated with high morbidity and complication rates. Despite these cautionary data, repeat resection of recurrent skull base meningiomas in appropriately selected patients provides excellent long-term survival.

Comparative diagnostic value of 18F-fluoride PET-CT versus MRI for skull-base bone invasion in nasopharyngeal carcinoma.

PubMed

Le, Yali; Chen, Yu; Zhou, Fan; Liu, Guangfu; Huang, Zhanwen; Chen, Yue

2016-10-01

This study compared the diagnostic value of F-fluoride PET-computed tomography (PET-CT) and MRI in skull-base bone erosion in nasopharyngeal carcinoma (NPC) patients. A total of 93 patients with biopsy-confirmed NPC were enrolled, including 68 men and 25 women between 23 and 74 years of age. All patients were evaluated by both F-fluoride PET-CT and MRI, and the interval between the two imaging examinations was less than 20 days. The patients received no treatment either before or between scans. The studies were interpreted by two nuclear medicine physicians or two radiologists with more than 10 years of professional experience who were blinded to both the diagnosis and the results of the other imaging studies. The reference standard was skull-base bone erosion at a 20-week follow-up imaging study. On the basis of the results of the follow-up imaging studies, 52 patients showed skull-base bone erosion. The numbers of true positives, false positives, true negatives, and false negatives with F-fluoride PET-CT were 49, 4, 37, and 3, respectively. The numbers of true positives, false positives, true negatives, and false negatives with MRI were 46, 5, 36, and 6, respectively. The sensitivity, specificity, and crude accuracy of F-fluoride PET-CT were 94.23, 90.24, and 92.47%, respectively; for MRI, these values were 88.46, 87.80, and 88.17%. Of the 52 patients, 43 showed positive findings both on F-fluoride PET-CT and on MRI. Within the patient cohort, F-fluoride PET-CT and MRI detected 178 and 135 bone lesions, respectively. Both F-fluoride PET-CT and MRI have high sensitivity, specificity, and crude accuracy for detecting skull-base bone invasion in patients with NPC. F-fluoride PET-CT detected more lesions than did MRI in the skull-base bone. This suggests that F-fluoride PET-CT has a certain advantage in evaluating the skull-base bone of NPC patients. Combining the two methods could improve the diagnostic accuracy of skull-base bone invasion for NPC.

Endoscopic endonasal approaches for the management of skull base meningiomas. Selection criteria and clinical outcomes.

PubMed

Todeschini, Alexandre B; Otto, Bradley A; Carrau, Ricardo L; Prevedello, Daniel M

2018-05-28

Meningiomas are the most common primary intracranial tumor, arising from different locations, including the skull base. Despite advances in adjuvant treatments, surgical resection remains the main and best treatment for meningiomas. New surgical strategies, such as the endoscopic endonasal approach, have greatly contributed in achieving maximum and total safe resection, preserving the patient's neurological function. Based on the senior authors large experience and a review of the current literature, we have compiled this chapter. We review the surgical technique used at our institution and the most relevant aspects of patient selection when considering resecting a skull base meningioma using the the EEA. Further consideration is given to some skull base meningiomas arising from specific locations with some case examples. The EEA is not an ideal approach for every skull base meningioma. Careful evaluation of the surrounding neurovascular structures surrounding the tumor is imperative to select the appropriate surgical corridor for a safe resection. Nevertheless, for appropriately selected cases, the endoscopic technique is a very valuable tool with some evidences of being superior to the microscopic transcranial approach. A dual-trained surgeon, in both endoscopic and transcranial approaches, is the best alternative to achieve the best patient outcome.

Creating Physical 3D Stereolithograph Models of Brain and Skull

PubMed Central

Kelley, Daniel J.; Farhoud, Mohammed; Meyerand, M. Elizabeth; Nelson, David L.; Ramirez, Lincoln F.; Dempsey, Robert J.; Wolf, Alan J.; Alexander, Andrew L.; Davidson, Richard J.

2007-01-01

The human brain and skull are three dimensional (3D) anatomical structures with complex surfaces. However, medical images are often two dimensional (2D) and provide incomplete visualization of structural morphology. To overcome this loss in dimension, we developed and validated a freely available, semi-automated pathway to build 3D virtual reality (VR) and hand-held, stereolithograph models. To evaluate whether surface visualization in 3D was more informative than in 2D, undergraduate students (n = 50) used the Gillespie scale to rate 3D VR and physical models of both a living patient-volunteer's brain and the skull of Phineas Gage, a historically famous railroad worker whose misfortune with a projectile tamping iron provided the first evidence of a structure-function relationship in brain. Using our processing pathway, we successfully fabricated human brain and skull replicas and validated that the stereolithograph model preserved the scale of the VR model. Based on the Gillespie ratings, students indicated that the biological utility and quality of visual information at the surface of VR and stereolithograph models were greater than the 2D images from which they were derived. The method we developed is useful to create VR and stereolithograph 3D models from medical images and can be used to model hard or soft tissue in living or preserved specimens. Compared to 2D images, VR and stereolithograph models provide an extra dimension that enhances both the quality of visual information and utility of surface visualization in neuroscience and medicine. PMID:17971879

A reevaluation of the anatomy of the jaw-closing system in the extant coelacanth Latimeria chalumnae

NASA Astrophysics Data System (ADS)

Dutel, Hugo; Herrel, Anthony; Clément, Gaël; Herbin, Marc

2013-11-01

The coelacanth Latimeria is the only extant representative of the Actinistia, a group of sarcopterygian fishes that originated in the Devonian. Moreover, it is the only extant vertebrate in which the neurocranium is divided into an anterior and a posterior portion that articulate by means of an intracranial joint. This joint is thought to be highly mobile, allowing an elevation of the anterior portion of the skull during prey capture. Here we provide a new description of the skull and jaw-closing system in Latimeria chalumnae in order to better understand its skull mechanics during prey capture. Based on a dissection and the CT scanning of an adult coelacanth, we provide a detailed description of the musculature and ligaments of the jaw system. We show that the m. adductor mandibulae is more complex than previously reported. We demonstrate that the basicranial muscle inserts more anteriorly than has been described previously, which has implications for its function. Moreover, the anterior insertion of the basicranial muscle does not correspond to the posterior tip of the tooth plate covering the parasphenoid, questioning previous inferences made on fossil coelacanths and other sarcopterygian fishes. Strong ligaments connect the anterior and the posterior portions of the skull at the level of the intracranial joint, as well as the notochord and the catazygals. These observations suggest that the intracranial joint is likely to be less mobile than previously thought and that its role during feeding merits to be reexamined.

The oldest anatomical handmade skull of the world c. 1508: 'the ugliness of growing old' attributed to Leonardo da Vinci.

PubMed

Missinne, Stefaan J

2014-06-01

The author discusses a previously unknown early sixteenth-century renaissance handmade anatomical miniature skull. The small, naturalistic skull made from an agate (calcedonia) stone mixture (mistioni) shows remarkable osteologic details. Dr. Saban was the first to link the skull to Leonardo. The three-dimensional perspective of and the search for the senso comune are discussed. Anatomical errors both in the drawings of Leonardo and this skull are presented. The article ends with the issue of physiognomy, his grotesque faces, the Perspective Communis and his experimenting c. 1508 with the stone mixture and the human skull. Evidence, including the Italian scale based on Crazie and Braccia, chemical analysis leading to a mine in Volterra and Leonardo's search for the soul in the skull are presented. Written references in the inventory of Salai (1524), the inventory of the Villa Riposo (Raffaello Borghini 1584) and Don Ambrogio Mazenta (1635) are reviewed. The author attributes the skull c. 1508 to Leonardo da Vinci.

Reconstruction Using Locoregional Flaps for Large Skull Base Defects.

PubMed

Hatano, Takaharu; Motomura, Hisashi; Ayabe, Shinobu

2015-06-01

We present a modified locoregional flap for the reconstruction of large anterior skull base defects that should be reconstructed with a free flap according to Yano's algorithm. No classification of skull base defects had been proposed for a long time. Yano et al suggested a new classification in 2012. The lb defect of Yano's classification extends horizontally from the cribriform plate to the orbital roof. According to Yano's algorithm for subsequent skull base reconstructive procedures, a lb defect should be reconstructed with a free flap such as an anterolateral thigh free flap or rectus abdominis myocutaneous free flap. However, our modified locoregional flap has also enabled reconstruction of lb defects. In this case series, we used a locoregional flap for lb defects. No major postoperative complications occurred. We present our modified locoregional flap that enables reconstruction of lb defects.

Lack of causal association between spontaneous intracranial hypotension and cranial cerebrospinal fluid leaks.

PubMed

Schievink, Wouter I; Schwartz, Marc S; Maya, M Marcel; Moser, Franklin G; Rozen, Todd D

2012-04-01

Spontaneous intracranial hypotension is an important cause of headaches and an underlying spinal CSF leak can be demonstrated in most patients. Whether CSF leaks at the level of the skull base can cause spontaneous intracranial hypotension remains a matter of controversy. The authors' aim was to examine the frequency of skull base CSF leaks as the cause of spontaneous intracranial hypotension. Demographic, clinical, and radiological data were collected from a consecutive group of patients evaluated for spontaneous intracranial hypotension during a 9-year period. Among 273 patients who met the diagnostic criteria for spontaneous intracranial hypotension and 42 who did not, not a single instance of CSF leak at the skull base was encountered. Clear nasal drainage was reported by 41 patients, but a diagnosis of CSF rhinorrhea could not be established. Four patients underwent exploratory surgery for presumed CSF rhinorrhea. In addition, the authors treated 3 patients who had a postoperative CSF leak at the skull base following the resection of a cerebellopontine angle tumor and developed orthostatic headaches; spinal imaging, however, demonstrated the presence of a spinal source of CSF leakage in all 3 patients. There is no evidence for an association between spontaneous intracranial hypotension and CSF leaks at the level of the skull base. Moreover, the authors' study suggests that a spinal source for CSF leakage should even be suspected in patients with orthostatic headaches who have a documented skull base CSF leak.

Detailed anatomy knowledge: first step to approach petroclival meningiomas through the petrous apex. Anatomy lab experience and surgical series.

PubMed

Altieri, Roberto; Sameshima, Tetsuro; Pacca, Paolo; Crobeddu, Emanuela; Garbossa, Diego; Ducati, Alessandro; Zenga, Francesco

2017-04-01

Petroclival meningiomas are a challenge for neurosurgeons due to the complex anatomy of the region that is rich of vessels and nerves. A perfect and detailed knowledge of the anatomy is very demanding in neurosurgery, especially in skull base surgery. The authors describe the microsurgical anatomy to perform an anterior petrosectomy based on their anatomical and surgical experience and perform a literature review. The temporal bone is the most complex and fascinating bone of skull base. The apex is located in the angle between the greater wing of the sphenoid and the occipital bone. Removing the petrous apex exposes the clivus. The approach directed through the temporal bone in this anatomical area is referred to as an anterior petrosectomy. The area that must be drilled is the rhomboid fossa that is defined by the Kawase, premeatal, and postmeatal triangles. In Division of Neurosurgery - University of Turin, 130 patients, from August 2013 to September 2015, underwent surgical resection of intracranial meningiomas. In this group, we have operated 7 PCMs and 5 of these were approached performing an anterior petrosectomy with good results. In our conclusions, we feel that this surgery require an advanced knowledge of human anatomy and a specialized training in interpretation of radiological and microsurgical anatomy both in the dissection lab and in the operating room.

Experimental demonstration of passive acoustic imaging in the human skull cavity using CT-based aberration corrections.

PubMed

Jones, Ryan M; O'Reilly, Meaghan A; Hynynen, Kullervo

2015-07-01

Experimentally verify a previously described technique for performing passive acoustic imaging through an intact human skull using noninvasive, computed tomography (CT)-based aberration corrections Jones et al. [Phys. Med. Biol. 58, 4981-5005 (2013)]. A sparse hemispherical receiver array (30 cm diameter) consisting of 128 piezoceramic discs (2.5 mm diameter, 612 kHz center frequency) was used to passively listen through ex vivo human skullcaps (n = 4) to acoustic emissions from a narrow-band fixed source (1 mm diameter, 516 kHz center frequency) and from ultrasound-stimulated (5 cycle bursts, 1 Hz pulse repetition frequency, estimated in situ peak negative pressure 0.11-0.33 MPa, 306 kHz driving frequency) Definity™ microbubbles flowing through a thin-walled tube phantom. Initial in vivo feasibility testing of the method was performed. The performance of the method was assessed through comparisons to images generated without skull corrections, with invasive source-based corrections, and with water-path control images. For source locations at least 25 mm from the inner skull surface, the modified reconstruction algorithm successfully restored a single focus within the skull cavity at a location within 1.25 mm from the true position of the narrow-band source. The results obtained from imaging single bubbles are in good agreement with numerical simulations of point source emitters and the authors' previous experimental measurements using source-based skull corrections O'Reilly et al. [IEEE Trans. Biomed. Eng. 61, 1285-1294 (2014)]. In a rat model, microbubble activity was mapped through an intact human skull at pressure levels below and above the threshold for focused ultrasound-induced blood-brain barrier opening. During bursts that led to coherent bubble activity, the location of maximum intensity in images generated with CT-based skull corrections was found to deviate by less than 1 mm, on average, from the position obtained using source-based corrections. Taken together, these results demonstrate the feasibility of using the method to guide bubble-mediated ultrasound therapies in the brain. The technique may also have application in ultrasound-based cerebral angiography.

Experimental demonstration of passive acoustic imaging in the human skull cavity using CT-based aberration corrections

PubMed Central

Jones, Ryan M.; O’Reilly, Meaghan A.; Hynynen, Kullervo

2015-01-01

Purpose: Experimentally verify a previously described technique for performing passive acoustic imaging through an intact human skull using noninvasive, computed tomography (CT)-based aberration corrections Jones et al. [Phys. Med. Biol. 58, 4981–5005 (2013)]. Methods: A sparse hemispherical receiver array (30 cm diameter) consisting of 128 piezoceramic discs (2.5 mm diameter, 612 kHz center frequency) was used to passively listen through ex vivo human skullcaps (n = 4) to acoustic emissions from a narrow-band fixed source (1 mm diameter, 516 kHz center frequency) and from ultrasound-stimulated (5 cycle bursts, 1 Hz pulse repetition frequency, estimated in situ peak negative pressure 0.11–0.33 MPa, 306 kHz driving frequency) Definity™ microbubbles flowing through a thin-walled tube phantom. Initial in vivo feasibility testing of the method was performed. The performance of the method was assessed through comparisons to images generated without skull corrections, with invasive source-based corrections, and with water-path control images. Results: For source locations at least 25 mm from the inner skull surface, the modified reconstruction algorithm successfully restored a single focus within the skull cavity at a location within 1.25 mm from the true position of the narrow-band source. The results obtained from imaging single bubbles are in good agreement with numerical simulations of point source emitters and the authors’ previous experimental measurements using source-based skull corrections O’Reilly et al. [IEEE Trans. Biomed. Eng. 61, 1285–1294 (2014)]. In a rat model, microbubble activity was mapped through an intact human skull at pressure levels below and above the threshold for focused ultrasound-induced blood–brain barrier opening. During bursts that led to coherent bubble activity, the location of maximum intensity in images generated with CT-based skull corrections was found to deviate by less than 1 mm, on average, from the position obtained using source-based corrections. Conclusions: Taken together, these results demonstrate the feasibility of using the method to guide bubble-mediated ultrasound therapies in the brain. The technique may also have application in ultrasound-based cerebral angiography. PMID:26133635

Prediction of skull fracture risk for children 0-9 months old through validated parametric finite element model and cadaver test reconstruction.

PubMed

Li, Zhigang; Liu, Weiguo; Zhang, Jinhuan; Hu, Jingwen

2015-09-01

Skull fracture is one of the most common pediatric traumas. However, injury assessment tools for predicting pediatric skull fracture risk is not well established mainly due to the lack of cadaver tests. Weber conducted 50 pediatric cadaver drop tests for forensic research on child abuse in the mid-1980s (Experimental studies of skull fractures in infants, Z Rechtsmed. 92: 87-94, 1984; Biomechanical fragility of the infant skull, Z Rechtsmed. 94: 93-101, 1985). To our knowledge, these studies contained the largest sample size among pediatric cadaver tests in the literature. However, the lack of injury measurements limited their direct application in investigating pediatric skull fracture risks. In this study, 50 pediatric cadaver tests from Weber's studies were reconstructed using a parametric pediatric head finite element (FE) model which were morphed into subjects with ages, head sizes/shapes, and skull thickness values that reported in the tests. The skull fracture risk curves for infants from 0 to 9 months old were developed based on the model-predicted head injury measures through logistic regression analysis. It was found that the model-predicted stress responses in the skull (maximal von Mises stress, maximal shear stress, and maximal first principal stress) were better predictors than global kinematic-based injury measures (peak head acceleration and head injury criterion (HIC)) in predicting pediatric skull fracture. This study demonstrated the feasibility of using age- and size/shape-appropriate head FE models to predict pediatric head injuries. Such models can account for the morphological variations among the subjects, which cannot be considered by a single FE human model.

Application of Thinned-Skull Cranial Window to Mouse Cerebral Blood Flow Imaging Using Optical Microangiography

PubMed Central

Wang, Ruikang K.

2014-01-01

In vivo imaging of mouse brain vasculature typically requires applying skull window opening techniques: open-skull cranial window or thinned-skull cranial window. We report non-invasive 3D in vivo cerebral blood flow imaging of C57/BL mouse by the use of ultra-high sensitive optical microangiography (UHS-OMAG) and Doppler optical microangiography (DOMAG) techniques to evaluate two cranial window types based on their procedures and ability to visualize surface pial vessel dynamics. Application of the thinned-skull technique is found to be effective in achieving high quality images for pial vessels for short-term imaging, and has advantages over the open-skull technique in available imaging area, surgical efficiency, and cerebral environment preservation. In summary, thinned-skull cranial window serves as a promising tool in studying hemodynamics in pial microvasculature using OMAG or other OCT blood flow imaging modalities. PMID:25426632

Sinonasal outcomes following endoscopic anterior skull base surgery with nasoseptal flap reconstruction: a prospective study.

PubMed

Hanson, M; Patel, P M; Betz, C; Olson, S; Panizza, B; Wallwork, B

2015-07-01

To assess nasal morbidity resulting from nasoseptal flap use in the repair of skull base defects in endoscopic anterior skull base surgery. Thirty-six patients awaiting endoscopic anterior skull base surgery were prospectively recruited. A nasoseptal flap was used for reconstruction in all cases. Patients were assessed pre-operatively and 90 days post-operatively via the Sino-Nasal Outcome Test 20 questionnaire and visual analogue scales for nasal obstruction, pain, secretions and smell; endoscopic examination findings and mucociliary clearance times were also recorded. Sino-Nasal Outcome Test 20 questionnaire data and visual analogue scale scores for pain, smell and secretions showed no significant differences between pre- and post-operative outcomes, with visual analogue scale scores for nasal obstruction actually showing a significant improvement (p = 0.0007). A significant deterioration for both flap and non-flap sides was demonstrated post-operatively on endoscopic examination (p = 0.002 and p = 0.02 respectively). Whilst elevation of a nasoseptal flap in endoscopic surgery of the anterior skull base engendered significant clinical deterioration on examination post-operatively, quality of life outcomes showed that no such deterioration was subjectively experienced by the patient. In fact, there was significant nasal airway improvement following nasoseptal flap reconstruction.

Harvey Cushing's Treatment of Skull Base Infections: The Johns Hopkins Experience

PubMed Central

Somasundaram, Aravind; Pendleton, Courtney; Raza, Shaan M.; Boahene, Kofi; Quinones-Hinojosa, Alfredo

2012-01-01

Objectives In this report, we review Dr. Cushing's early surgical cases at the Johns Hopkins Hospital, revealing details of his early operative approaches to infections of the skull base. Design Following institutional review board (IRB) approval, and through the courtesy of the Alan Mason Chesney Archives, we reviewed the Johns Hopkins Hospital surgical files from 1896 to 1912. Setting The Johns Hopkins Hospital, 1896 to 1912. Participants Eleven patients underwent operative treatment for suspected infections of the skull base. Main Outcome Measures The main outcome measure was operative approach, postoperative mortality, and condition recorded at the time of discharge. Results Eleven patients underwent operative intervention for infections of the skull base. The mean age was 30 years (range: 9 to 63). Of these patients, seven (64%) were female. The mean length of stay was 16.5 days (range: 4 to 34). Postoperatively eight patients were discharged in “well” or “good” condition, one patient remained “unimproved,” and two patients died during their admission. Conclusion Cushing's careful preoperative observation of patients, meticulous operative technique, and judicious use of postoperative drainage catheters contributed to a remarkably low mortality rate in his series of skull base infections. PMID:24083129

Clinical diagnostic dilemma of intracranial germinoma manifesting as wide skull base extension.

PubMed

Zhou, Zhi-hang; Zhang, Hai-bo; Rao, Jun; Bian, Xiu-wu

2014-09-01

The aims of this study were to present an uncommon intracranial germinoma manifesting as skull base extension and analyze its clinical characteristics to give valuable insight into such uncommon radiologic variant. This is a clinical study of a 15-year-old girl with intracranial germinoma manifesting as skull base extension. Clinical characteristics, magnetic resonance imaging scan observations, pathologic findings, and flow of the treatment procedure were presented and analyzed. She had a 5-month history of diuresis and diplopia. magnetic resonance imaging observation displayed a neoplasm located in the right-side central skull base and suprasellar area with wide extension into the cavernous sinus, intraorbital region, ethmoidal sinus, sphenoid sinus, and pituitary fossa. After administration of contrast medium, strong and heterogeneous enhancement of the mass was observed, with a dural tail sign along the right cerebellar tentorial. Right pterional approach was performed, and intraoperative histologic examination suspected the diagnosis of germinoma; partial resection was achieved, and postoperative radiotherapy was administered. Cranial nerve palsy improved greatly 6 months postoperatively. Although highly unusual, germinoma should be included in the differential diagnosis of all masses with extension along the midline region of skull base, especially when it happens in young female patients.

Metastatic Renal Cell Carcinoma Masquerading as Jugular Foramen Paraganglioma: A Role for Novel Magnetic Resonance Imaging.

PubMed

Thomas, Andrew J; Wiggins, Richard H; Gurgel, Richard K

2017-08-01

To describe a case of metastatic renal cell carcinoma (RCC) masquerading as a jugular foramen paraganglioma (JP). To compare imaging findings between skull base metastatic RCC and histologically proven paraganglioma. A case of unexpected metastatic skull base RCC is reviewed. Computed tomography (CT) and magnetic resonance imaging (MRI) were compared between 3 confirmed cases of JP and our case of metastatic RCC. Diffusion-weighted MRI (DW-MRI) sequences and computed apparent diffusion coefficient (ADC) values were compared between these entities. A 55-year-old man presents with what appears clinically and radiographically to be JP. The tumor was resected, then discovered on postoperative pathology to be metastatic RCC. Imaging was retrospectively compared between 3 histologically confirmed cases of JP and our case of skull base RCC. The RCC metastasis was indistinguishable from JP on CT and traditional MRI but distinct by ADC values calculated from DW-MRI. Metastatic RCC at the skull base may mimic the clinical presentation and radiographic appearance of JP. The MRI finding of flow voids is seen in both paraganglioma and metastatic RCC. Diffusion-weighted MRI is able to distinguish these entities, highlighting its potential utility in distinguishing skull base lesions.

Multi-atlas and label fusion approach for patient-specific MRI based skull estimation.

PubMed

Torrado-Carvajal, Angel; Herraiz, Joaquin L; Hernandez-Tamames, Juan A; San Jose-Estepar, Raul; Eryaman, Yigitcan; Rozenholc, Yves; Adalsteinsson, Elfar; Wald, Lawrence L; Malpica, Norberto

2016-04-01

MRI-based skull segmentation is a useful procedure for many imaging applications. This study describes a methodology for automatic segmentation of the complete skull from a single T1-weighted volume. The skull is estimated using a multi-atlas segmentation approach. Using a whole head computed tomography (CT) scan database, the skull in a new MRI volume is detected by nonrigid image registration of the volume to every CT, and combination of the individual segmentations by label-fusion. We have compared Majority Voting, Simultaneous Truth and Performance Level Estimation (STAPLE), Shape Based Averaging (SBA), and the Selective and Iterative Method for Performance Level Estimation (SIMPLE) algorithms. The pipeline has been evaluated quantitatively using images from the Retrospective Image Registration Evaluation database (reaching an overlap of 72.46 ± 6.99%), a clinical CT-MR dataset (maximum overlap of 78.31 ± 6.97%), and a whole head CT-MRI pair (maximum overlap 78.68%). A qualitative evaluation has also been performed on MRI acquisition of volunteers. It is possible to automatically segment the complete skull from MRI data using a multi-atlas and label fusion approach. This will allow the creation of complete MRI-based tissue models that can be used in electromagnetic dosimetry applications and attenuation correction in PET/MR. © 2015 Wiley Periodicals, Inc.

[Establishment of a 3D finite element model of human skull using MSCT images and mimics software].

PubMed

Huang, Ping; Li, Zheng-dong; Shao, Yu; Zou, Dong-hua; Liu, Ning-guo; Li, Li; Chen, Yuan-yuan; Wan, Lei; Chen, Yi-jiu

2011-02-01

To establish a human 3D finite element skull model, and to explore its value in biomechanics analysis. The cadaveric head was scanned and then 3D skull model was created using Mimics software based on 2D CT axial images. The 3D skull model was optimized by preprocessor along with creation of the surface and volume meshes. The stress changes, after the head was struck by an object or the head hit the ground directly, were analyzed using ANSYS software. The original 3D skull model showed a large number of triangles with a poor quality and high similarity with the real head, while the optimized model showed high quality surface and volume meshes with a small number of triangles comparatively. The model could show the local and global stress changes effectively. The human 3D skull model can be established using MSCT and Mimics software and provides a good finite element model for biomechanics analysis. This model may also provide a base for the study of head stress changes following different forces.

Augmented reality-assisted skull base surgery.

PubMed

Cabrilo, I; Sarrafzadeh, A; Bijlenga, P; Landis, B N; Schaller, K

2014-12-01

Neuronavigation is widely considered as a valuable tool during skull base surgery. Advances in neuronavigation technology, with the integration of augmented reality, present advantages over traditional point-based neuronavigation. However, this development has not yet made its way into routine surgical practice, possibly due to a lack of acquaintance with these systems. In this report, we illustrate the usefulness and easy application of augmented reality-based neuronavigation through a case example of a patient with a clivus chordoma. We also demonstrate how augmented reality can help throughout all phases of a skull base procedure, from the verification of neuronavigation accuracy to intraoperative image-guidance. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Intraoperative Neurophysiological Monitoring for Endoscopic Endonasal Approaches to the Skull Base: A Technical Guide

PubMed Central

Lober, Robert M.; Doan, Adam T.; Matsumoto, Craig I.; Kenning, Tyler J.; Evans, James J.

2016-01-01

Intraoperative neurophysiological monitoring during endoscopic, endonasal approaches to the skull base is both feasible and safe. Numerous reports have recently emerged from the literature evaluating the efficacy of different neuromonitoring tests during endonasal procedures, making them relatively well-studied. The authors report on a comprehensive, multimodality approach to monitoring the functional integrity of at risk nervous system structures, including the cerebral cortex, brainstem, cranial nerves, corticospinal tract, corticobulbar tract, and the thalamocortical somatosensory system during endonasal surgery of the skull base. The modalities employed include electroencephalography, somatosensory evoked potentials, free-running and electrically triggered electromyography, transcranial electric motor evoked potentials, and auditory evoked potentials. Methodological considerations as well as benefits and limitations are discussed. The authors argue that, while individual modalities have their limitations, multimodality neuromonitoring provides a real-time, comprehensive assessment of nervous system function and allows for safer, more aggressive management of skull base tumors via the endonasal route. PMID:27293965

[Anatomy of the skull base and the cranial nerves in slice imaging].

PubMed

Bink, A; Berkefeld, J; Zanella, F

2009-07-01

Computed tomography (CT) and magnetic resonance imaging (MRI) are suitable methods for examination of the skull base. Whereas CT is used to evaluate mainly bone destruction e.g. for planning surgical therapy, MRI is used to show pathologies in the soft tissue and bone invasion. High resolution and thin slice thickness are indispensible for both modalities of skull base imaging. Detailed anatomical knowledge is necessary even for correct planning of the examination procedures. This knowledge is a requirement to be able to recognize and interpret pathologies. MRI is the method of choice for examining the cranial nerves. The total path of a cranial nerve can be visualized by choosing different sequences taking into account the tissue surrounding this cranial nerve. This article summarizes examination methods of the skull base in CT and MRI, gives a detailed description of the anatomy and illustrates it with image examples.

Genomic and transcriptomic characterization of skull base chordoma

PubMed Central

Sa, Jason K.; Lee, In-Hee; Hong, Sang Duk; Kong, Doo-Sik; Nam, Do-Hyun

2017-01-01

Skull base chordoma is a primary rare malignant bone-origin tumor showing relatively slow growth pattern and locally destructive lesions, which can only be characterized by histologic components. There is no available prognostic or therapeutic biomarker to predict clinical outcome or treatment response and the molecular mechanisms underlying chordoma development still remain unexplored. Therefore, we sought out to identify novel somatic variations that are associated with chordoma progression and potentially employed as therapeutic targets. Thirteen skull base chordomas were subjected for whole-exome and/or whole-transcriptome sequencing. In process, we have identified chromosomal aberration in 1p, 7, 10, 13 and 17q, high frequency of functional germline SNP of the T gene, rs2305089 (P = 0.0038) and several recurrent alterations including MUC4, NBPF1, NPIPB15 mutations and novel gene fusion of SAMD5-SASH1 for the first time in skull base chordoma. PMID:27901492

Genomic and transcriptomic characterization of skull base chordoma.

PubMed

Sa, Jason K; Lee, In-Hee; Hong, Sang Duk; Kong, Doo-Sik; Nam, Do-Hyun

2017-01-03

Skull base chordoma is a primary rare malignant bone-origin tumor showing relatively slow growth pattern and locally destructive lesions, which can only be characterized by histologic components. There is no available prognostic or therapeutic biomarker to predict clinical outcome or treatment response and the molecular mechanisms underlying chordoma development still remain unexplored. Therefore, we sought out to identify novel somatic variations that are associated with chordoma progression and potentially employed as therapeutic targets. Thirteen skull base chordomas were subjected for whole-exome and/or whole-transcriptome sequencing. In process, we have identified chromosomal aberration in 1p, 7, 10, 13 and 17q, high frequency of functional germline SNP of the T gene, rs2305089 (P = 0.0038) and several recurrent alterations including MUC4, NBPF1, NPIPB15 mutations and novel gene fusion of SAMD5-SASH1 for the first time in skull base chordoma.

Form and function of damselfish skulls: rapid and repeated evolution into a limited number of trophic niches.

PubMed

Cooper, W James; Westneat, Mark W

2009-01-30

Damselfishes (Perciformes, Pomacentridae) are a major component of coral reef communities, and the functional diversity of their trophic anatomy is an important constituent of the ecological morphology of these systems. Using shape analyses, biomechanical modelling, and phylogenetically based comparative methods, we examined the anatomy of damselfish feeding among all genera and trophic groups. Coordinate based shape analyses of anatomical landmarks were used to describe patterns of morphological diversity and determine positions of functional groups in a skull morphospace. These landmarks define the lever and linkage structures of the damselfish feeding system, and biomechanical analyses of this data were performed using the software program JawsModel4 in order to calculate the simple mechanical advantage (MA) employed by different skull elements during feeding, and to compute kinematic transmission coefficients (KT) that describe the efficiency with which angular motion is transferred through the complex linkages of damselfish skulls. Our results indicate that pomacentrid planktivores are significantly different from other damselfishes, that biting MA values and protrusion KT ratios are correlated with pomacentrid trophic groups more tightly than KT scores associated with maxillary rotation and gape angle, and that the MAs employed by their three biting muscles have evolved independently. Most of the biomechanical parameters examined have experienced low levels of phylogenetic constraint, which suggests that they have evolved quickly. Joint morphological and biomechanical analyses of the same anatomical data provided two reciprocally illuminating arrays of information. Both analyses showed that the evolution of planktivory has involved important changes in pomacentrid functional morphology, and that the mechanics of upper jaw kinesis have been of great importance to the evolution of damselfish feeding. Our data support a tight and biomechanically defined link between structure and the functional ecology of fish skulls, and indicate that certain mechanisms for transmitting motion through their jaw linkages may require particular anatomical configurations, a conclusion that contravenes the concept of "many-to-one mapping" for fish jaw mechanics. Damselfish trophic evolution is characterized by rapid and repeated shifts between a small number of eco-morphological states, an evolutionary pattern that we describe as reticulate adaptive radiation.

Skull base trauma: diagnosis and management.

PubMed

Samii, Madjid; Tatagiba, Marcos

2002-03-01

The singular anatomical relationship of the base of the skull is responsible for the particular problems that may arise after injury. Extensive dural laceration and severe neurovascular damage may accompany skull base injuries. Trauma to the anterior skull base is frequently related to the paranasal sinuses, and trauma to the middle and the posterior skull base usually affects the petrous bone. Injury to the anterior fossa including the paranasal sinuses may produce CSF leakage, damage the olfactory nerves, optic nerves, and orbita contents. Fractures may affect the carotid canal, injure the internal carotid artery and result in carotid-cavernous fistula. Trauma to the petrous bone may cause facial palsy and deafness, and CSF leakage with otorrhoea or paradoxal rhinoliquorrhoea. Trauma to the posterior fossa may lacerate the major venous sinuses, and affect the cranio-cervical stability. Each one of these injuries will need a particular strategy. Decision making for management as a whole must consider all aspects, including the fact that these injuries frequently involve polytraumatized patients. Decisions regarding the timing of surgery and the sequence of the surgical procedures must be made with great care. Modern surgical techniques and recent technologies including functional preservation of the olfactory nerves in frontobasal trauma, visual evoked potentials, assisted optic nerve decompression, facial nerve reconstruction, interventional technique for intravascular repair of vascular injuries, and recent developments in cochlea implants and brain stem implants, all contributed significantly to improve outcome and enhance the quality of life of patients. This article reviews basic principles of management of skull base trauma stressing the role of these advanced techniques.

Ontogenetic study of the skull in modern humans and the common chimpanzees: neotenic hypothesis reconsidered with a tridimensional Procrustes analysis.

PubMed

Penin, Xavier; Berge, Christine; Baylac, Michel

2002-05-01

Heterochronic studies compare ontogenetic trajectories of an organ in different species: here, the skulls of common chimpanzees and modern humans. A growth trajectory requires three parameters: size, shape, and ontogenetic age. One of the great advantages of the Procrustes method is the precise definition of size and shape for whole organs such as the skull. The estimated ontogenetic age (dental stages) is added to the plot to give a graphical representation to compare growth trajectories. We used the skulls of 41 Homo sapiens and 50 Pan troglodytes at various stages of growth. The Procrustes superimposition of all specimens was completed by statistical procedures (principal component analysis, multivariate regression, and discriminant function) to calculate separately size-related shape changes (allometry common to chimpanzees and humans), and interspecific shape differences (discriminant function). The results confirm the neotenic theory of the human skull (sensu Gould [1977] Ontogeny and Phylogeny, Cambridge: Harvard University Press; Alberch et al. [1979] Paleobiology 5:296-317), but modify it slightly. Human growth is clearly retarded in terms of both the magnitude of changes (size-shape covariation) and shape alone (size-shape dissociation) with respect to the chimpanzees. At the end of growth, the adult skull in humans reaches an allometric shape (size-related shape) which is equivalent to that of juvenile chimpanzees with no permanent teeth, and a size which is equivalent to that of adult chimpanzees. Our results show that human neoteny involves not only shape retardation (paedomorphosis), but also changes in relative growth velocity. Before the eruption of the first molar, human growth is accelerated, and then strongly decelerated, relative to the growth of the chimpanzee as a reference. This entails a complex process, which explains why these species reach the same overall (i.e., brain + face) size in adult stage. The neotenic traits seem to concern primarily the function of encephalization, but less so other parts of the skull. Our results, based on the discriminant function, reveal that additional structural traits (corresponding to the nonallometric part of the shape which is specific to humans) are rather situated in the other part of the skull. They mainly concern the equilibrium of the head related to bipedalism, and the respiratory and masticatory functions. Thus, the reduced prognathism, the flexed cranial base (forward position of the foramen magnum which is brought closer to the palate), the reduced anterior portion of the face, the reduced glabella, and the prominent nose mainly correspond to functional innovations which have nothing to do with a neotenic process in human evolution. The statistical analysis used here gives us the possibility to point out that some traits, which have been classically described as paedomorphic because they superficially resemble juvenile traits, are in reality independent of growth. Copyright 2002 Wiley-Liss, Inc.

Heavy ion therapy: Bevalac epoch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castro, J.R.

1993-10-01

An overview of heavy ion therapy at the Bevelac complex (SuperHILac linear accelerator + Bevatron) is given. Treatment planning, clinical results with helium ions on the skull base and uveal melanoma, clinical results with high-LET charged particles, neon radiotherapy of prostate cancer, heavy charged particle irradiation for unfavorable soft tissue sarcoma, preliminary results in heavy charged particle irradiation of bone sarcoma, and irradiation of bile duct carcinoma with charged particles and-or photons are all covered. (GHH)

[A case of pycnodysostosis--observation of the skull by CT scan].

PubMed

Anegawa, S; Bekki, Y; Furukawa, Y; Yokota, S; Torigoe, R

1987-07-01

A 13-year-old boy was presented to the Department of Neurosurgery, Saiseikai Fukuoka General Hospital for further examinations concerning abnormal findings in the skull radiogram taken when he struck his head. His physical features showed some characteristics the same as those of pycnodysostosis as follows--proportionate dwarfism, prominent forehead, short spoon-shaped fingers, bilateral exophthalmos. A skull radiogram revealed widely open cranial sutures with no healing of the fracture and craniotomy which was performed for an acute epidural hematoma 6 years ago. Furthermore, the mandible was hypoplastic with a virtual loss of mandibular angle. CT of the soft tissues showed somewhat dilated cortical sulci and ventricles without any structural abnormalities in the brain. CT of bone algorithm revealed specific characteristics of this disease. The paranasal sinuses were quite hypoplastic. Especially in the maxillary sinuses, frontal sinuses and mastoid air cells, none of developments of sinuses were noted, even though the middle and internal ear seemed to be normal. Moreover, the ethmoid and sphenoid sinuses were noted, although their developments were poor. The appearance of skull base was normal, including the inlets and outlets of cranial nerves or vessels and synchondroses. However, the density of the skull base, especially in the diploe, was higher than normal in Hansfield number. Furthermore, detailed measurements of skull base demonstrated that the skull base itself was also dwarfism. Pycnodysostosis is a generalized skeletal disease whose cardinal features are moderate generalized osteosclerosis and dwarfism. However, the detailed observation on the cranium by CT has not been reported. In our study, the development of sinuses in bones with intramembranous ossification are worse than that with endochondral ossification.(ABSTRACT TRUNCATED AT 250 WORDS)

Integration of Brain and Skull in Prenatal Mouse Models of Apert and Crouzon Syndromes

PubMed Central

Motch Perrine, Susan M.; Stecko, Tim; Neuberger, Thomas; Jabs, Ethylin W.; Ryan, Timothy M.; Richtsmeier, Joan T.

2017-01-01

The brain and skull represent a complex arrangement of integrated anatomical structures composed of various cell and tissue types that maintain structural and functional association throughout development. Morphological integration, a concept developed in vertebrate morphology and evolutionary biology, describes the coordinated variation of functionally and developmentally related traits of organisms. Syndromic craniosynostosis is characterized by distinctive changes in skull morphology and perceptible, though less well studied, changes in brain structure and morphology. Using mouse models for craniosynostosis conditions, our group has precisely defined how unique craniosynostosis causing mutations in fibroblast growth factor receptors affect brain and skull morphology and dysgenesis involving coordinated tissue-specific effects of these mutations. Here we examine integration of brain and skull in two mouse models for craniosynostosis: one carrying the FGFR2c C342Y mutation associated with Pfeiffer and Crouzon syndromes and a mouse model carrying the FGFR2 S252W mutation, one of two mutations responsible for two-thirds of Apert syndrome cases. Using linear distances estimated from three-dimensional coordinates of landmarks acquired from dual modality imaging of skull (high resolution micro-computed tomography and magnetic resonance microscopy) of mice at embryonic day 17.5, we confirm variation in brain and skull morphology in Fgfr2cC342Y/+ mice, Fgfr2+/S252W mice, and their unaffected littermates. Mutation-specific variation in neural and cranial tissue notwithstanding, patterns of integration of brain and skull differed only subtly between mice carrying either the FGFR2c C342Y or the FGFR2 S252W mutation and their unaffected littermates. However, statistically significant and substantial differences in morphological integration of brain and skull were revealed between the two mutant mouse models, each maintained on a different strain. Relative to the effects of disease-associated mutations, our results reveal a stronger influence of the background genome on patterns of brain-skull integration and suggest robust genetic, developmental, and evolutionary relationships between neural and skeletal tissues of the head. PMID:28790902

[The transperygoid approach to the removal of a recurrent juvenile angiofibroma at the base of the skull without preoperative embolization].

PubMed

Grachev, N S; Vorozhtsov, I N

The authors report a clinical case of successful elimination of a recurrent juvenile angiofibroma at the base of the skull (JAFBS) with the application of the optical navigation system and a cold plasma scalpel in the absence of preoperative embolization. It has been demonstrated using the proposed transperygoid approach to the extirpation of the tumour that a recurrent juvenile angiofibroma at the base of the skull can be efficiently removed by means of a modern minimally invasive and at the same time radical surgical method.

Neurophysiological Identification of Cranial Nerves During Endoscopic Endonasal Surgery of Skull Base Tumors: Pilot Study Technical Report.

PubMed

Shkarubo, Alexey Nikolaevich; Chernov, Ilia Valerievich; Ogurtsova, Anna Anatolievna; Moshchev, Dmitry Aleksandrovich; Lubnin, Andrew Jurievich; Andreev, Dmitry Nicolaevich; Koval, Konstantin Vladimirovich

2017-02-01

Intraoperative identification of cranial nerves is crucial for safe surgery of skull base tumors. Currently, only a small number of published papers describe the technique of trigger electromyography (t-EMG) in endoscopic endonasal removal of such tumors. To assess the effectiveness of t-EMG in preventing intraoperative cranial nerve damage in endoscopic endonasal surgery of skull base tumors. Nine patients were operated on using the endoscopic endonasal approach within a 1-year period. The tumors included large skull base chordomas and trigeminal neurinomas localized in the cavernous sinus. During the surgical process, cranial nerve identification was carried out using monopolar and bipolar t-EMG methods. Assessment of cranial nerve functional activity was conducted both before and after tumor removal. We mapped 17 nerves in 9 patients. Third, fifth, and sixth cranial nerves were identified intraoperatively. There were no cases of postoperative functional impairment of the mapped cranial nerves. In one case we were unable to get an intraoperative response from the fourth cranial nerve and observed its postoperative transient plegia (the function was normal before surgery). t-EMG allows surgeons to control the safety of cranial nerves both during and after skull base tumor removal. Copyright © 2016 Elsevier Inc. All rights reserved.

[Applicability of the da Vinci robotic system in the skull base surgical approach. Preclinical investigation].

PubMed

Fernandez-Nogueras Jimenez, Francisco J; Segura Fernandez-Nogueras, Miguel; Jouma Katati, Majed; Arraez Sanchez, Miguel Ángel; Roda Murillo, Olga; Sánchez Montesinos, Indalecio

2015-01-01

The role of robotic surgery is well established in various specialties such as urology and general surgery, but not in others such as neurosurgery and otolaryngology. In the case of surgery of the skull base, it has just emerged from an experimental phase. To investigate possible applications of the da Vinci surgical robot in transoral skull base surgery, comparing it with the authors' experience using conventional endoscopic transnasal surgery in the same region. A transoral transpalatal approach to the nasopharynx and medial skull base was performed on 4 cryopreserved cadaver heads. We used the da Vinci robot, a 30° standard endoscope 12mm thick, dual camera and dual illumination, Maryland forceps on the left terminal and curved scissors on the right, both 8mm thick. Bone drilling was performed manually. For the anatomical study of this region, we used 0.5cm axial slices from a plastinated cadaver head. Various skull base structures at different depths were reached with relative ease with the robot terminals Transoral robotic surgery with the da Vinci system provides potential advantages over conventional endoscopic transnasal surgery in the surgical approach to this region. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

Pedicled Extranasal Flaps in Skull Base Reconstruction

PubMed Central

Kim, Grace G.; Hang, Anna X.; Mitchell, Candace; Zanation, Adam M.

2013-01-01

Cerebrospinal fluid (CSF) leaks most commonly arise during or after skull base surgery, although they occasionally present spontaneously. Recent advances in the repair of CSF leaks have enabled endoscopic endonasal surgery to become the preferred option for management of skull base pathology. Small defects (<1cm) can be repaired by multilayered free grafts. For large defects (>3cm), pedicled vascular flaps are the repair method of choice, resulting in much lower rates of postoperative CSF leaks. The pedicled nasoseptal flap (NSF) constitutes the primary reconstructive option for the vast majority of skull base defects. It has a large area of potential coverage and high rates of success. However, preoperative planning is required to avoid sacrificing the NSF during resection. In cases where the NSF is unavailable, often due to tumor involvement of the septum or previous resection removing or compromising the flap, other flaps may be considered. These flaps include intranasal options—inferior turbinate (IT) or middle turbinate (MT) flaps—as well as regional pedicled flaps: pericranial flap (PCF), temporoparietal fascial flap (TPFF), or palatal flap (PF). More recently, novel alternatives such as the pedicled facial buccinator flap (FAB) and the pedicled occipital galeopericranial flap (OGP) have been added to the arsenal of options for skull base reconstruction. Characteristics of and appropriate uses for each flap are described. PMID:23257554

Endoscopic endonasal skull base surgery: advantages, limitations, and our techniques to overcome cerebrospinal fluid leakage: technical note.

PubMed

Ishii, Yudo; Tahara, Shigeyuki; Teramoto, Akira; Morita, Akio

2014-01-01

In recent years, resections of midline skull base tumors have been conducted using endoscopic endonasal skull base (EESB) approaches. Nevertheless, many surgeons reported that cerebrospinal fluid (CSF) leakage is still a major complication of these approaches. Here, we report the results of our 42 EESB surgeries and discuss the advantages and limits of this approach for resecting various types of tumors, and also report our technique to overcome CSF leakage. All 42 cases involved midline skull base tumors resected using the EESB technique. Dural incisions were closed using nasoseptal flaps and fascia patch inlay sutures. Total removal of the tumor was accomplished in seven pituitary adenomas (33.3%), five craniopharyngiomas (62.5%), five tuberculum sellae meningiomas (83.3%), three clival chordomas (100%), and one suprasellar ependymoma. Residual regions included the cavernous sinus, the outside of the intracranial part of the internal carotid artery, the lower lateral part of the posterior clivus, and the posterior pituitary stalk. Overall incidence of CSF leakage was 7.1%. Even though the versatility of the approach is limited, EESB surgery has many advantages compared to the transcranial approach for managing mid-line skull base lesions. To avoid CSF leakage, surgeons should have skills and techniques for complete closure, including use of the nasoseptal flap and fascia patch inlay techniques.

Relationships between scalp, brain, and skull motion estimated using magnetic resonance elastography.

PubMed

Badachhape, Andrew A; Okamoto, Ruth J; Johnson, Curtis L; Bayly, Philip V

2018-05-17

The objective of this study was to characterize the relationships between motion in the scalp, skull, and brain. In vivo estimates of motion transmission from the skull to the brain may illuminate the mechanics of traumatic brain injury. Because of challenges in directly sensing skull motion, it is useful to know how well motion of soft tissue of the head, i.e., the scalp, can approximate skull motion or predict brain tissue deformation. In this study, motion of the scalp and brain were measured using magnetic resonance elastography (MRE) and separated into components due to rigid-body displacement and dynamic deformation. Displacement estimates in the scalp were calculated using low motion-encoding gradient strength in order to reduce "phase wrapping" (an ambiguity in displacement estimates caused by the 2 π-periodicity of MRE phase contrast). MRE estimates of scalp and brain motion were compared to skull motion estimated from three tri-axial accelerometers. Comparison of the relative amplitudes and phases of harmonic motion in the scalp, skull, and brain of six human subjects indicate that data from scalp-based sensors should be used with caution to estimate skull kinematics, but that fairly consistent relationships exist between scalp, skull, and brain motion. In addition, the measured amplitude and phase relationships of scalp, skull, and brain can be used to evaluate and improve mathematical models of head biomechanics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Skull's acoustic attenuation and dispersion modeling on photoacoustic signal

NASA Astrophysics Data System (ADS)

Mohammadi, Leila; Behnam, Hamid; Tavakkoli, Jahan; Nasiriavanaki, Mohammadreza

2018-02-01

Despite the promising results of the recent novel transcranial photoacoustic (PA) brain imaging technology, it has been demonstrated that the presence of the skull severely affects the performance of this imaging modality. We theoretically investigate the effects of acoustic heterogeneity induced by skull on the PA signals generated from single particles, with firstly developing a mathematical model for this phenomenon and then explore experimental validation of the results. The model takes into account the frequency dependent attenuation and dispersion effects occur with wave reflection, refraction and mode conversion at the skull surfaces. Numerical simulations based on the developed model are performed for calculating the propagation of photoacoustic waves through the skull. The results show a strong agreement between simulation and ex-vivo study. The findings are as follow: The thickness of the skull is the most PA signal deteriorating factor that affects both its amplitude (attenuation) and phase (distortion). Also we demonstrated that, when the depth of target region is low and it is comparable to the skull thickness, however, the skull-induced distortion becomes increasingly severe and the reconstructed image would be strongly distorted without correcting these effects. It is anticipated that an accurate quantification and modeling of the skull transmission effects would ultimately allow for aberration correction in transcranial PA brain imaging.

Transcranial Near-Infrared Laser Transmission (NILT) Profiles (800 nm): Systematic Comparison in Four Common Research Species

PubMed Central

Lapchak, Paul A.; Boitano, Paul D.; Butte, Pramod V.; Fisher, David J.; Hölscher, Thilo; Ley, Eric J.; Nuño, Miriam; Voie, Arne H.; Rajput, Padmesh S.

2015-01-01

Background and Purpose Transcranial near-infrared laser therapy (TLT) is a promising and novel method to promote neuroprotection and clinical improvement in both acute and chronic neurodegenerative diseases such as acute ischemic stroke (AIS), traumatic brain injury (TBI), and Alzheimer’s disease (AD) patients based upon efficacy in translational animal models. However, there is limited information in the peer-reviewed literature pertaining to transcranial near-infrared laser transmission (NILT) profiles in various species. Thus, in the present study we systematically evaluated NILT characteristics through the skull of 4 different species: mouse, rat, rabbit and human. Results Using dehydrated skulls from 3 animal species, using a wavelength of 800nm and a surface power density of 700 mW/cm2, NILT decreased from 40.10% (mouse) to 21.24% (rat) to 11.36% (rabbit) as skull thickness measured at bregma increased from 0.44 mm in mouse to 0.83 mm in rat and then 2.11 mm in rabbit. NILT also significantly increased (p<0.05) when animal skulls were hydrated (i.e. compared to dehydrated); but there was no measurable change in thickness due to hydration. In human calvaria, where mean thickness ranged from 7.19 mm at bregma to 5.91 mm in the parietal skull, only 4.18% and 4.24% of applied near-infrared light was transmitted through the skull. There was a slight (9.2-13.4%), but insignificant effect of hydration state on NILT transmission of human skulls, but there was a significant positive correlation between NILT and thickness at bregma and parietal skull, in both hydrated and dehydrated states. Conclusion This is the first systematic study to demonstrate differential NILT through the skulls of 4 different species; with an inverse relationship between NILT and skull thickness. With animal skulls, transmission profiles are dependent upon the hydration state of the skull, with significantly greater penetration through hydrated skulls compared to dehydrated skulls. Using human skulls, we demonstrate a significant correlation between thickness and penetration, but there was no correlation with skull density. The results suggest that TLT should be optimized in animals using novel approaches incorporating human skull characteristics, because of significant variance of NILT profiles directly related to skull thickness. PMID:26039354

A hybrid skull-stripping algorithm based on adaptive balloon snake models

NASA Astrophysics Data System (ADS)

Liu, Hung-Ting; Sheu, Tony W. H.; Chang, Herng-Hua

2013-02-01

Skull-stripping is one of the most important preprocessing steps in neuroimage analysis. We proposed a hybrid algorithm based on an adaptive balloon snake model to handle this challenging task. The proposed framework consists of two stages: first, the fuzzy possibilistic c-means (FPCM) is used for voxel clustering, which provides a labeled image for the snake contour initialization. In the second stage, the contour is initialized outside the brain surface based on the FPCM result and evolves under the guidance of the balloon snake model, which drives the contour with an adaptive inward normal force to capture the boundary of the brain. The similarity indices indicate that our method outperformed the BSE and BET methods in skull-stripping the MR image volumes in the IBSR data set. Experimental results show the effectiveness of this new scheme and potential applications in a wide variety of skull-stripping applications.

The journey of discovering skull base anatomy in ancient Egypt and the special influence of Alexandria.

PubMed

Elhadi, Ali M; Kalb, Samuel; Perez-Orribo, Luis; Little, Andrew S; Spetzler, Robert F; Preul, Mark C

2012-08-01

The field of anatomy, one of the most ancient sciences, first evolved in Egypt. From the Early Dynastic Period (3100 BC) until the time of Galen at the end of the 2nd century ad, Egypt was the center of anatomical knowledge, including neuroanatomy. Knowledge of neuroanatomy first became important so that sacred rituals could be performed by ancient Egyptian embalmers during mummification procedures. Later, neuroanatomy became a science to be studied by wise men at the ancient temple of Memphis. As religious conflicts developed, the study of the human body became restricted. Myths started to replace scientific research, squelching further exploration of the human body until Alexander the Great founded the city of Alexandria. This period witnessed a revolution in the study of anatomy and functional anatomy. Herophilus of Chalcedon, Erasistratus of Chios, Rufus of Ephesus, and Galen of Pergamon were prominent physicians who studied at the medical school of Alexandria and contributed greatly to knowledge about the anatomy of the skull base. After the Royal Library of Alexandria was burned and laws were passed prohibiting human dissections based on religious and cultural factors, knowledge of human skull base anatomy plateaued for almost 1500 years. In this article the authors consider the beginning of this journey, from the earliest descriptions of skull base anatomy to the establishment of basic skull base anatomy in ancient Egypt.

An investigation into the accuracy and reliability of skull-photo superimposition in a South African sample.

PubMed

Gordon, G M; Steyn, M

2012-03-10

One of the aims of forensic science is to determine the identities of victims of crime. In some cases the investigators may have ideas as to the identities of the victims and in these situations, ante mortem photographs of the victims could be used in order to try and establish identity through skull-photo superimposition. The aim of this study was to evaluate the accuracy of a newly developed digital photographic superimposition technique on a South African sample of cadaver photographs and skulls. Forty facial photographs were selected and for each photo, 10 skulls (including the skull corresponding to the photo) were used for superimposition. The investigator did not know which of the 10 skulls corresponded to the photograph in question. The skulls were scanned 3-dimensionally, using a Cyberware™ Model 3030 Colour-3D Scanhead scanner. The photos were also scanned. Superimposition was done in 3D Studio Max and involved a morphological superimposition, whereby a skull is superimposed over the photo and assessed for a morphological match. Superimposition using selected anatomical landmarks was also performed to assess the match. A total of 400 skull-photo superimpositions were carried out using the morphological assessment and another 400 using the anatomical landmarks. In 85% of cases the correct skull was included in the possible matches for a particular photo using morphological assessment. However, in all of these cases, between zero and three other skulls out of 10 possibilities could also match a specific photo. In the landmark based assessment, the correct skull was included in 80% of cases. Once again, however, between one and seven other skulls out of 10 possibilities also matched the photo. This indicates that skull-photo superimposition has limited use in the identification of human skeletal remains, but may be useful as an initial screening tool. Corroborative techniques should also be used in the identification process. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Bone up: craniomandibular development and hard-tissue biomineralization in neonate mice.

PubMed

Thompson, Khari D; Weiss-Bilka, Holly E; McGough, Elizabeth B; Ravosa, Matthew J

2017-10-01

The presence of regional variation in the osteogenic abilities of cranial bones underscores the fact that the mechanobiology of the mammalian skull is more complex than previously recognized. However, the relationship between patterns of cranial bone formation and biomineralization remains incompletely understood. In four strains of mice, micro-computed tomography was used to measure tissue mineral density during perinatal development in three skull regions (calvarium, basicranium, mandible) noted for variation in loading environment, embryological origin, and ossification mode. Biomineralization levels increased during perinatal ontogeny in the mandible and calvarium, but did not increase in the basicranium. Tissue mineral density levels also varied intracranially, with density in the mandible being highest, in the basicranium intermediate, and in the calvarium lowest. Perinatal increases in, and elevated levels of, mandibular biomineralization appear related to the impending postweaning need to resist elevated masticatory stresses. Similarly, perinatal increases in calvarial biomineralization may be linked to ongoing brain expansion, which is known to stimulate sutural bone formation in this region. The lack of perinatal increase in basicranial biomineralization could be a result of earlier developmental maturity in the cranial base relative to other skull regions due to its role in supporting the brain's mass throughout ontogeny. These results suggest that biomineralization levels and age-related trajectories throughout the skull are influenced by the functional environment and ontogenetic processes affecting each region, e.g., onset of masticatory loads in the mandible, whereas variation in embryology and ossification mode may only have secondary effects on patterns of biomineralization. Knowledge of perinatal variation in tissue mineral density, and of normal cranial bone formation early in development, may benefit clinical therapies aiming to correct developmental defects and traumatic injuries in the skull, and more generally characterize loading environments and skeletal adaptations in mammals by highlighting the need for multi-level analyses for evaluating functional performance of cranial bone. Copyright © 2017 Elsevier GmbH. All rights reserved.

Radiological features of the skull in Klinefelter's syndrome and male hypogonadism.

PubMed

Kosowicz, J; Rzymski, K

1975-07-01

Skull radiographs were performed in 21 cases of Klinefelter's syndrome and in 30 cases of eunuchoidism. The radiographic changes of the skull in Klinefelter's syndrome are: temporal flattening, decreased width of the vault, narrowing of the mandible, decreased length of the skull, shortening of the anterior fossa cranii, decrease in the angle of the base, thinning of the vault bones at the major fontanelle, premature and excessive calcification of the coronal suture, deepening of the posterior fossa and shortening of the mandibular rami. In hypogonadotropic eunuchoidism the skull radiographs show: small mastoid processes, fine bones of the vault, small sella turcica, club-shaped clinoid processes, excessive development of sphenoidal sinuses and in the fourth and later decades of life a diminished bone density (osteoporosis).

Unusual case of post-traumatic lingual paraesthesia.

PubMed

Tekeli, K M; Agrawal, T; Worrall, S F

2008-03-01

We report an unusual case of lingual paraesthesia caused by a fracture of the base of the skull involving the foramen ovale. As far as we know, lingual sensory neuropathy associated purely with a fracture of the base of the skull has not been reported before.

Extended endoscopic endonasal skull base surgery: from the sella to the anterior and posterior cranial fossa.

PubMed

Oostra, Amanda; van Furth, Wouter; Georgalas, Christos

2012-03-01

Skull base surgery has gone through significant changes with the development of extended endoscopic endonasal approaches over the last decade. Initially used for the transphenoidal removal of hypophyseal adenomas, the endoscopic transnasal approach gradually evolved into a way of accessing the whole ventral skull base. Improved visualization, avoidance of brain retraction, the ability to access directly tumours with minimal damage to critical neurosurgical structures as well lack of external scars are among its obvious benefits. However, it presents the surgeons with a number of challenges, including the need to deal endoscopically with potential arterial bleeding, complicated reconstruction requirements as well as the need for a true team approach. In this review drawing from our experience as well as published series, we present an overview of current indications, challenges and limitations of the expanded endonasal approaches to the skull base. © 2012 The Authors. ANZ Journal of Surgery © 2012 Royal Australasian College of Surgeons.

Removal of a foreign body from the skull base using a customized computer-designed guide bar.

PubMed

Wei, Ran; Xiang-Zhen, Liu; Bing, Guo; Da-Long, Shu; Ze-Ming, Tan

2010-06-01

Foreign bodies located at the base of the skull pose a surgical challenge. Here, a customized computer-designed surgical guide bar was designed to facilitate removal of a skull base foreign body. Within 24h of the patient's presentation, a guide bar and mounting platform were designed to remove a foreign body located adjacent to the transverse process of the atlas and pressing against the internal carotid artery. The foreign body was successfully located and removed using the custom designed guide bar and computer operative planning. Ten months postoperatively the patient was free of complaints and lacked any complications such as restricted opening of the mouth or false aneurysm. The inferior alveolar nerve damage noted immediately postoperatively (a consequence of mandibular osteotomy) was slightly reduced at follow-up, but labial numbness persisted. The navigation tools described herein were successfully employed to aid foreign body removal from the skull base. Copyright (c) 2009 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Subcranial approach in the surgical treatment of anterior skull base trauma.

PubMed

Schaller, B

2005-04-01

Fractures of the anterior skull base, because of the region's anatomical relationships, are readily complicated by neurological damage to the brain or cranial nerves. This review highlights the use of a subcranial approach in the operative treatment of injuries of the anterior skull base and compares it to the more traditional neurosurgical transcranial approach. The extended anterior subcranial approach takes advantage of the specific features of injuries in this region and allows direct access to the central anterior cranial base in order to repair fractures, close CSF fistulae and relieve of optic nerve compression. It avoids extensive frontal lobe manipulation. The success of the approach in achieving the aims of surgery with low morbidity is reviewed.

Random Positional Variation Among the Skull, Mandible, and Cervical Spine With Treatment Progression During Head-and-Neck Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahn, Peter H.; Ahn, Andrew I.; Lee, C. Joe

2009-02-01

Purpose: With 54{sup o} of freedom from the skull to mandible to C7, ensuring adequate immobilization for head-and-neck radiotherapy (RT) is complex. We quantify variations in skull, mandible, and cervical spine movement between RT sessions. Methods and Materials: Twenty-three sequential head-and-neck RT patients underwent serial computed tomography. Patients underwent planned rescanning at 11, 22, and 33 fractions for a total of 93 scans. Coordinates of multiple bony elements of the skull, mandible, and cervical spine were used to calculate rotational and translational changes of bony anatomy compared with the original planning scan. Results: Mean translational and rotational variations on rescanningmore » were negligible, but showed a wide range. Changes in scoliosis and lordosis of the cervical spine between fractions showed similar variability. There was no correlation between positional variation and fraction number and no strong correlation with weight loss or skin separation. Semi-independent rotational and translation movement of the skull in relation to the lower cervical spine was shown. Positioning variability measured by means of vector displacement was largest in the mandible and lower cervical spine. Conclusions: Although only small overall variations in position between head-and-neck RT sessions exist on average, there is significant random variation in patient positioning of the skull, mandible, and cervical spine elements. Such variation is accentuated in the mandible and lower cervical spine. These random semirigid variations in positioning of the skull and spine point to a need for improved immobilization and/or confirmation of patient positioning in RT of the head and neck.« less

Growth overshoot and seasonal size changes in the skulls of two weasel species

PubMed Central

Keicher, Lara; Wikelski, Martin; Zub, Karol; Dechmann, Dina K. N.

2017-01-01

Ontogenetic changes in mammalian skulls are complex. For a very few species (i.e. some Sorex shrews), these also include seasonally driven, bidirectional size changes within individuals, presumably to reduce energy requirements during low resource availabilities. These patterns are poorly understood, but are likely most pronounced in high-metabolic species with limited means for energy conservation. We used generalized additive models to quantify the effect of location, Julian day, age and sex on the length and depth of 512 and 847 skulls of stoat (Mustela erminea) and weasel (M. nivalis) specimens collected throughout the northern hemisphere. Skull length of both species varies between sexes and geographically, with stoat skull length positively correlated with latitude. Both species demonstrate seasonal and ontogenetic patterns, including a rare, absolute growth overshoot in juvenile braincase depth. Standardized braincase depths of both species peak in their first summer, then decrease in their first winter, followed by a remarkable regrowth that peaks again during their second summer. This seasonal pattern varies in magnitude and timing between geographical regions and the sexes, matching predictions of Dehnel's phenomenon. This suggests implications for the evolution of over-wintering strategies in mammals, justifying further research on their mechanisms and value, with implications for applied osteology research. PMID:28280592

Transfer of children with isolated linear skull fractures: is it worth the cost?

PubMed

White, Ian K; Pestereva, Ecaterina; Shaikh, Kashif A; Fulkerson, Daniel H

2016-05-01

OBJECTIVE Children with skull fractures are often transferred to hospitals with pediatric neurosurgical capabilities. Historical data suggest that a small percentage of patients with an isolated skull fracture will clinically decline. However, recent papers have suggested that the risk of decline in certain patients is low. There are few data regarding the financial costs associated with transporting patients at low risk for requiring specialty care. In this study, the clinical outcomes and financial costs of transferring of a population of children with isolated skull fractures to a Level 1 pediatric trauma center over a 9-year period were analyzed. METHODS A retrospective review of all children treated for head injury at Riley Hospital for Children (Indianapolis, Indiana) between 2005 and 2013 was performed. Patients with a skull fracture were identified based on ICD-9 codes. Patients with intracranial hematoma, brain parenchymal injury, or multisystem trauma were excluded. Children transferred to Riley Hospital from an outside facility were identified. The clinical and radiographic outcomes were recorded. A cost analysis was performed on patients who were transferred with an isolated, linear, nondisplaced skull fracture. RESULTS Between 2005 and 2013, a total of 619 pediatric patients with isolated skull fractures were transferred. Of these, 438 (70.8%) patients had a linear, nondisplaced skull fracture. Of these 438 patients, 399 (91.1%) were transferred by ambulance and 39 (8.9%) by helicopter. Based on the current ambulance and helicopter fees, a total of $1,834,727 (an average of $4188.90 per patient) was spent on transfer fees alone. No patient required neurosurgical intervention. All patients recovered with symptomatic treatment; no patient suffered late decline or epilepsy. CONCLUSIONS This study found that nearly $2 million was spent solely on transfer fees for 438 pediatric patients with isolated linear skull fractures over a 9-year period. All patients in this study had good clinical outcomes, and none required neurosurgical intervention. Based on these findings, the authors suggest that, in the absence of abuse, most children with isolated, linear, nondisplaced skull fractures do not require transfer to a Level 1 pediatric trauma center. The authors suggest ideas for further study to refine the protocols for determining which patients require transport.

A fiducial skull marker for precise MRI-based stereotaxic surgery in large animal models.

PubMed

Glud, Andreas Nørgaard; Bech, Johannes; Tvilling, Laura; Zaer, Hamed; Orlowski, Dariusz; Fitting, Lise Moberg; Ziedler, Dora; Geneser, Michael; Sangill, Ryan; Alstrup, Aage Kristian Olsen; Bjarkam, Carsten Reidies; Sørensen, Jens Christian Hedemann

2017-06-15

Stereotaxic neurosurgery in large animals is used widely in different sophisticated models, where precision is becoming more crucial as desired anatomical target regions are becoming smaller. Individually calculated coordinates are necessary in large animal models with cortical and subcortical anatomical differences. We present a convenient method to make an MRI-visible skull fiducial for 3D MRI-based stereotaxic procedures in larger experimental animals. Plastic screws were filled with either copper-sulfate solution or MRI-visible paste from a commercially available cranial head marker. The screw fiducials were inserted in the animal skulls and T1 weighted MRI was performed allowing identification of the inserted skull marker. Both types of fiducial markers were clearly visible on the MRÍs. This allows high precision in the stereotaxic space. The use of skull bone based fiducial markers gives high precision for both targeting and evaluation of stereotaxic systems. There are no metal artifacts and the fiducial is easily removed after surgery. The fiducial marker can be used as a very precise reference point, either for direct targeting or in evaluation of other stereotaxic systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Innovative real CSF leak simulation model for rhinology training: human cadaveric design.

PubMed

AlQahtani, Abdulaziz A; Albathi, Abeer A; Alhammad, Othman M; Alrabie, Abdulkarim S

2018-04-01

To study the feasibility of designing a human cadaveric simulation model of real CSF leak for rhinology training. The laboratory investigation took place at the surgical academic center of Prince Sultan Military Medical City between 2016 and 2017. Five heads of human cadaveric specimens were cannulated into the intradural space through two frontal bone holes. Fluorescein-dyed fluid was injected intracranialy, then endoscopic endonasal iatrogenic skull base defect was created with observation of fluid leak, followed by skull base reconstruction. The outcome measures included subjective assessment of integrity of the design, the ability of creating real CSF leak in multiple site of skull base and the possibility of watertight closure by various surgical techniques. The fluid filled the intradural space in all specimens without spontaneous leak from skull base or extra sinus areas. Successfully, we demonstrated fluid leak from all areas after iatrogenic defect in the cribriform plate, fovea ethmoidalis, planum sphenoidale sellar and clival regions. Watertight closure was achieved in all defects using different reconstruction techniques (overly, underlay and gasket seal closure). The design is simulating the real patient with CSF leak. It has potential in the learning process of acquiring and maintaining the surgical skills of skull base reconstruction before direct involvement of the patient. This model needs further evaluation and competence measurement as training tools in rhinology training.

Management of Anterior Skull Base Defect Depending on Its Size and Location

PubMed Central

Bernal-Sprekelsen, Manuel; Rioja, Elena; Enseñat, Joaquim; Enriquez, Karla; Viscovich, Liza; Agredo-Lemos, Freddy Enrique; Alobid, Isam

2014-01-01

Introduction. We present our experience in the reconstruction of these leaks depending on their size and location. Material and Methods. Fifty-four patients who underwent advanced skull base surgery (large defects, >20 mm) and 62 patients with CSF leaks of different origin (small, 2–10 mm, and midsize, 11–20 mm, defects) were included in the retrospective study. Large defects were reconstructed with a nasoseptal pedicled flap positioned on fat and fascia lata. In small and midsized leaks. Fascia lata in an underlay position was used for its reconstruction covered with mucoperiosteum of either the middle or the inferior turbinate. Results. The most frequent etiology for small and midsized defects was spontaneous (48.4%), followed by trauma (24.2%), iatrogenic (5%). The success rate after the first surgical reconstruction was 91% and 98% in large skull base defects and small/midsized, respectively. Rescue surgery achieved 100%. Conclusions. Endoscopic surgery for any type of skull base defect is the gold standard. The size of the defects does not seem to play a significant role in the success rate. Fascia lata and mucoperiosteum of the turbinate allow a two-layer reconstruction of small and midsized defects. For larger skull base defects, a combination of fat, fascia lata, and nasoseptal pedicled flaps provides a successful reconstruction. PMID:24895567

Endoscopic Endonasal Skull Base Surgery: Advantages, Limitations, and Our Techniques to Overcome Cerebrospinal Fluid Leakage: Technical Note

PubMed Central

ISHII, Yudo; TAHARA, Shigeyuki; TERAMOTO, Akira; MORITA, Akio

2014-01-01

In recent years, resections of midline skull base tumors have been conducted using endoscopic endonasal skull base (EESB) approaches. Nevertheless, many surgeons reported that cerebrospinal fluid (CSF) leakage is still a major complication of these approaches. Here, we report the results of our 42 EESB surgeries and discuss the advantages and limits of this approach for resecting various types of tumors, and also report our technique to overcome CSF leakage. All 42 cases involved midline skull base tumors resected using the EESB technique. Dural incisions were closed using nasoseptal flaps and fascia patch inlay sutures. Total removal of the tumor was accomplished in seven pituitary adenomas (33.3%), five craniopharyngiomas (62.5%), five tuberculum sellae meningiomas (83.3%), three clival chordomas (100%), and one suprasellar ependymoma. Residual regions included the cavernous sinus, the outside of the intracranial part of the internal carotid artery, the lower lateral part of the posterior clivus, and the posterior pituitary stalk. Overall incidence of CSF leakage was 7.1%. Even though the versatility of the approach is limited, EESB surgery has many advantages compared to the transcranial approach for managing mid-line skull base lesions. To avoid CSF leakage, surgeons should have skills and techniques for complete closure, including use of the nasoseptal flap and fascia patch inlay techniques. PMID:25446379

Prediction and near-field observation of skull-guided acoustic waves

NASA Astrophysics Data System (ADS)

Estrada, Héctor; Rebling, Johannes; Razansky, Daniel

2017-06-01

Ultrasound waves propagating in water or soft biological tissue are strongly reflected when encountering the skull, which limits the use of ultrasound-based techniques in transcranial imaging and therapeutic applications. Current knowledge on the acoustic properties of the cranial bone is restricted to far-field observations, leaving its near-field unexplored. We report on the existence of skull-guided acoustic waves, which was herein confirmed by near-field measurements of optoacoustically-induced responses in ex-vivo murine skulls immersed in water. Dispersion of the guided waves was found to reasonably agree with the prediction of a multilayered flat plate model. We observed a skull-guided wave propagation over a lateral distance of at least 3 mm, with a half-decay length in the direction perpendicular to the skull ranging from 35 to 300 μm at 6 and 0.5 MHz, respectively. Propagation losses are mostly attributed to the heterogenous acoustic properties of the skull. It is generally anticipated that our findings may facilitate and broaden the application of ultrasound-mediated techniques in brain diagnostics and therapy.

Prediction and near-field observation of skull-guided acoustic waves.

PubMed

Estrada, Héctor; Rebling, Johannes; Razansky, Daniel

2017-06-21

Ultrasound waves propagating in water or soft biological tissue are strongly reflected when encountering the skull, which limits the use of ultrasound-based techniques in transcranial imaging and therapeutic applications. Current knowledge on the acoustic properties of the cranial bone is restricted to far-field observations, leaving its near-field unexplored. We report on the existence of skull-guided acoustic waves, which was herein confirmed by near-field measurements of optoacoustically-induced responses in ex-vivo murine skulls immersed in water. Dispersion of the guided waves was found to reasonably agree with the prediction of a multilayered flat plate model. We observed a skull-guided wave propagation over a lateral distance of at least 3 mm, with a half-decay length in the direction perpendicular to the skull ranging from 35 to 300 μm at 6 and 0.5 MHz, respectively. Propagation losses are mostly attributed to the heterogenous acoustic properties of the skull. It is generally anticipated that our findings may facilitate and broaden the application of ultrasound-mediated techniques in brain diagnostics and therapy.

Collagen matrix as an inlay in endoscopic skull base reconstruction.

PubMed

Oakley, G M; Christensen, J M; Winder, M; Jonker, B P; Davidson, A; Steel, T; Teo, C; Harvey, R J

2018-03-01

Multi-layer reconstruction has become standard in endoscopic skull base surgery. The inlay component used can vary among autografts, allografts, xenografts and synthetics, primarily based on surgeon preference. The short- and long-term outcomes of collagen matrix in skull base reconstruction are described. A case series of patients who underwent endoscopic skull base reconstruction with collagen matrix inlay were assessed. Immediate peri-operative outcomes (cerebrospinal fluid leak, meningitis, ventriculitis, intracranial bleeding, epistaxis, seizures) and delayed complications (delayed healing, meningoencephalocele, prolapse of reconstruction, delayed cerebrospinal fluid leak, ascending meningitis) were examined. Of 120 patients (51.0 ± 17.5 years, 41.7 per cent female), peri-operative complications totalled 12.7 per cent (cerebrospinal fluid leak, 3.3 per cent; meningitis, 3.3 per cent; other intracranial infections, 2.5 per cent; intracranial bleeding, 1.7 per cent; epistaxis, 1.7 per cent; and seizures, 0 per cent). Delayed complications did not occur in any patients. Collagen matrix is an effective inlay material. It provides robust long-term separation between sinus and cranial cavities, and avoids donor site morbidity, but carries additional cost.

Transnasal endoscopic partial maxillectomy: Operative nuances and proposal for a comprehensive classification system based on 1378 cases.

PubMed

Turri-Zanoni, Mario; Battaglia, Paolo; Karligkiotis, Apostolos; Lepera, Davide; Zocchi, Jacopo; Dallan, Iacopo; Bignami, Maurizio; Castelnuovo, Paolo

2017-04-01

Despite the development of functional endoscopic endonasal surgery, there are still areas of the maxillary sinus that remain technically difficult to access using a standard middle meatal antrostomy as well as deep-seated skull base lesions requiring expanded transmaxillary approaches. All patients who underwent transnasal endoscopic partial maxillectomy (TEPM) in a single institution from 2000 to 2014 were retrospectively reviewed. The TEPM was classified into 5 types according to the anatomic structures progressively removed and to the access provided. The TEPM was performed in 1378 patients for the management of: inflammatory diseases in 513 cases (37%), benign sinonasal tumors in 425 cases (31%), skull base malignancies in 285 cases (21%), and as a corridor to address deep-seated skull base lesions in 155 cases (11%). The TEPM is a stepwise approach offering increasing access that can be tailored to different maxillary, sinonasal, and skull base pathologies with minimal morbidity for patients. © 2016 Wiley Periodicals, Inc. Head Neck 39: 754-766, 2017. © 2016 Wiley Periodicals, Inc.

Usefulness of an Osteotomy Template for Skull Tumorectomy and Simultaneous Skull Reconstruction.

PubMed

Oji, Tomito; Sakamoto, Yoshiaki; Miwa, Tomoru; Nakagawa, Yu; Yoshida, Kazunari; Kishi, Kazuo

2016-09-01

Simultaneous tumor resection and cranioplasty with hydroxyapatite osteosynthesis are sometimes necessary in patients of skull neoplasms or skull-invasive tumors. However, the disadvantage of simultaneous surgery is that mismatches often occur between the skull defect and the hydroxyapatite implant. To solve this problem, the authors developed a customized template for designing the craniotomy line. Before each operation, the craniotomy design was discussed with a neurosurgeon. Based on the discussion, 2 hydroxyapatite implants were customized for each patient on the basis of models prepared using computed tomography data. The first implant was an onlay template for the preoperative cranium, which was customized for designing the osteotomy line. The other implant was used for the skull defect. Using the template, the osteotomy line was drawn along the template edge, osteotomy was performed along this line, and the implant was placed in the skull defect. This technique was performed in 3 patients. No implant or defect trimming was required in any patient, good cosmetic outcomes were noted in all patients, and no complications occurred. Use of predesigned hydroxyapatite templates for craniotomy during simultaneous skull tumor resection and cranioplasty has some clinical advantages: the precise craniotomy line can be designed, the implant and skull defect fit better and show effective osteoconduction, trimming of the implant or defect is minimized, and the operation time is shortened.

Changes in human skull morphology across the agricultural transition are consistent with softer diets in preindustrial farming groups.

PubMed

Katz, David C; Grote, Mark N; Weaver, Timothy D

2017-08-22

Agricultural foods and technologies are thought to have eased the mechanical demands of diet-how often or how hard one had to chew-in human populations worldwide. Some evidence suggests correspondingly worldwide changes in skull shape and form across the agricultural transition, although these changes have proved difficult to characterize at a global scale. Here, adapting a quantitative genetics mixed model for complex phenotypes, we quantify the influence of diet on global human skull shape and form. We detect modest directional differences between foragers and farmers. The effects are consistent with softer diets in preindustrial farming groups and are most pronounced and reliably directional when the farming class is limited to dairying populations. Diet effect magnitudes are relatively small, affirming the primary role of neutral evolutionary processes-genetic drift, mutation, and gene flow structured by population history and migrations-in shaping diversity in the human skull. The results also bring an additional perspective to the paradox of why Homo sapiens , particularly agriculturalists, appear to be relatively well suited to efficient (high-leverage) chewing.

Cancer around the brain

PubMed Central

Grisold, Wolfgang; Grisold, Anna

2014-01-01

Background Neuro-oncologists are familiar with primary brain tumors, intracerebral metastases meningeal carcinomatosis and extracerebral intracranial tumors as meningeoma. For these conditions, and also some other rare tumor entities several treatment options exist. Cancer can also involve structures around the brain as the dura, the base of the skull, the cavities of the skull and tissue around the bony skull, the skin, the tissue of the neck. and either compress, invade or spread in the central or peripheral nervous system. Methods A systematic literature research was conducted determining symptoms and signs, tumor sites of nerve invasion, tumor types, diagnostic techniques, mechanisms of nerve invasion, and important differential diagnosis. Additional cases from own experience were added for illustration. Results The mechanisms of tumor invasion of cranial nerves is heterogenous and not only involves several types of invasion, but also spread along the cranial nerves in antero- and retrograde fashion and even spread into different nerve territories via anastomosis. In addition the concept of angiosomas may have an influence on the spread of metastases. Conclusion In addition to the well described tumor spread in meningeal carcinomatosis and base of the skull metastases, dural spread, lesions of the bony skull, the cavities of the skull and skin of the face and tissue of the neck region need to be considered, and have an impact on therapeutic decisions. PMID:26034610

Numerical evaluation of the skull for human neuromodulation with transcranial focused ultrasound

NASA Astrophysics Data System (ADS)

Mueller, Jerel K.; Ai, Leo; Bansal, Priya; Legon, Wynn

2017-12-01

Objective. Transcranial focused ultrasound is an emerging field for human non-invasive neuromodulation, but its dosing in humans is difficult to know due to the skull. The objective of the present study was to establish modeling methods based on medical images to assess skull differences between individuals on the wave propagation of ultrasound. Approach. Computational models of transcranial focused ultrasound were constructed using CT and MR scans to solve for intracranial pressure. We explored the effect of including the skull base in models, different transducer placements on the head, and differences between 250 kHz or 500 kHz acoustic frequency for both female and male models. We further tested these features using linear, nonlinear, and elastic simulations. To better understand inter-subject skull thickness and composition effects we evaluated the intracranial pressure maps between twelve individuals at two different skull sites. Main results. Nonlinear acoustic simulations resulted in virtually identical intracranial pressure maps with linear acoustic simulations. Elastic simulations showed a difference in max pressures and full width half maximum volumes of 15% at most. Ultrasound at an acoustic frequency of 250 kHz resulted in the creation of more prominent intracranial standing waves compared to 500 kHz. Finally, across twelve model human skulls, a significant linear relationship to characterize intracranial pressure maps was not found. Significance. Despite its appeal, an inherent problem with the use of a noninvasive transcranial ultrasound method is the difficulty of knowing intracranial effects because of the skull. Here we develop detailed computational models derived from medical images of individuals to simulate the propagation of neuromodulatory ultrasound across the skull and solve for intracranial pressure maps. These methods allow for a much better understanding of the intracranial effects of ultrasound for an individual in order to ensure proper targeting and more tightly control dosing.

Transversal craniofacial growth evaluated on children dry skulls using V2 and V 3 canal openings as references.

PubMed

Harnet, J C; Lombardi, T; Manière-Ezvan, A; Chamorey, E; Kahn, J L

2013-11-01

The aim of this study was to investigate the transversal relationships between two cephalometric landmarks and lines on the face using ovale, rotundum, greater palatine and infra-orbital foramina as references. Thirty-four children dry skulls, 19 males and 15 females aged 0-6 years, were examined by computed tomography scanning by using constructed tomographic axial and frontal planes. The cephalometric transversal dimensions of the face skull were measured between the right and left landmarks from the orbital lateral wall and from the zygomatic arch. The cephalometric transversal dimensions of the base skull were measured between the right and left ovale, rotundum, greater palatine and infra-orbital foramina. Statistical analysis using partial correlations, regardless of the age, showed strong relationships (p < 0.05) among transversal measurements with nerve canal openings and transversal distances of skull face. We showed that the cranial base transversal growth was very strongly related to facial transversal growth from the postnatal period up to 6 years of age.

Investigation of the elastic modulus, tensile and flexural strength of five skull simulant materials for impact testing of a forensic skin/skull/brain model.

PubMed

Falland-Cheung, Lisa; Waddell, J Neil; Chun Li, Kai; Tong, Darryl; Brunton, Paul

2017-04-01

Conducting in vitro research for forensic, impact and injury simulation modelling generally involves the use of a skull simulant with mechanical properties similar to those found in the human skull. For this study epoxy resin, fibre filled epoxy resin, 3D-printing filaments (PETG, PLA) and self-cure acrylic denture base resin were used to fabricate the specimens (n=20 per material group), according to ISO 527-2 IBB and ISO20795-1. Tensile and flexural testing in a universal testing machine was used to measure their tensile/flexural elastic modulus and strength. The results showed that the epoxy resin and fibre filled epoxy resin had similar tensile elastic moduli (no statistical significant difference) with lower values observed for the other materials. The fibre filled epoxy resin had a considerably higher flexural elastic modulus and strength, possibly attributed to the presence of fibres. Of the simulants tested, epoxy resin had an elastic modulus and flexural strength close to that of mean human skull values reported in the literature, and thus can be considered as a suitable skull simulant for a skin/skull/brain model for lower impact forces that do not exceed the fracture stress. For higher impact forces a 3D printing filament (PLA) may be a more suitable skull simulant material, due to its closer match to fracture stresses found in human skull bone. Influencing factors were also anisotropy, heterogeneity and viscoelasticity of human skull bone and simulant specimens. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evolutionary origin of the turtle skull.

PubMed

Bever, G S; Lyson, Tyler R; Field, Daniel J; Bhullar, Bhart-Anjan S

2015-09-10

Transitional fossils informing the origin of turtles are among the most sought-after discoveries in palaeontology. Despite strong genomic evidence indicating that turtles evolved from within the diapsid radiation (which includes all other living reptiles), evidence of the inferred transformation between an ancestral turtle with an open, diapsid skull to the closed, anapsid condition of modern turtles remains elusive. Here we use high-resolution computed tomography and a novel character/taxon matrix to study the skull of Eunotosaurus africanus, a 260-million-year-old fossil reptile from the Karoo Basin of South Africa, whose distinctive postcranial skeleton shares many unique features with the shelled body plan of turtles. Scepticism regarding the status of Eunotosaurus as the earliest stem turtle arises from the possibility that these shell-related features are the products of evolutionary convergence. Our phylogenetic analyses indicate strong cranial support for Eunotosaurus as a critical transitional form in turtle evolution, thus fortifying a 40-million-year extension to the turtle stem and moving the ecological context of its origin back onto land. Furthermore, we find unexpected evidence that Eunotosaurus is a diapsid reptile in the process of becoming secondarily anapsid. This is important because categorizing the skull based on the number of openings in the complex of dermal bone covering the adductor chamber has long held sway in amniote systematics, and still represents a common organizational scheme for teaching the evolutionary history of the group. These discoveries allow us to articulate a detailed and testable hypothesis of fenestral closure along the turtle stem. Our results suggest that Eunotosaurus represents a crucially important link in a chain that will eventually lead to consilience in reptile systematics, paving the way for synthetic studies of amniote evolution and development.

First complete sauropod dinosaur skull from the Cretaceous of the Americas and the evolution of sauropod dentition.

PubMed

Chure, Daniel; Britt, Brooks B; Whitlock, John A; Wilson, Jeffrey A

2010-04-01

Sauropod dinosaur bones are common in Mesozoic terrestrial sediments, but sauropod skulls are exceedingly rare--cranial materials are known for less than one third of sauropod genera and even fewer are known from complete skulls. Here we describe the first complete sauropod skull from the Cretaceous of the Americas, Abydosaurus mcintoshi, n. gen., n. sp., known from 104.46 +/- 0.95 Ma (megannum) sediments from Dinosaur National Monument, USA. Abydosaurus shares close ancestry with Brachiosaurus, which appeared in the fossil record ca. 45 million years earlier and had substantially broader teeth. A survey of tooth shape in sauropodomorphs demonstrates that sauropods evolved broad crowns during the Early Jurassic but did not evolve narrow crowns until the Late Jurassic, when they occupied their greatest range of crown breadths. During the Cretaceous, brachiosaurids and other lineages independently underwent a marked diminution in tooth breadth, and before the latest Cretaceous broad-crowned sauropods were extinct on all continental landmasses. Differential survival and diversification of narrow-crowned sauropods in the Late Cretaceous appears to be a directed trend that was not correlated with changes in plant diversity or abundance, but may signal a shift towards elevated tooth replacement rates and high-wear dentition. Sauropods lacked many of the complex herbivorous adaptations present within contemporaneous ornithischian herbivores, such as beaks, cheeks, kinesis, and heterodonty. The spartan design of sauropod skulls may be related to their remarkably small size--sauropod skulls account for only 1/200th of total body volume compared to 1/30th body volume in ornithopod dinosaurs.

Neck swelling due to skull base (pseudo)meningocele protruding through a congenital skull base bone defect: a case report.

PubMed

Sharma, Rajeev; Singh, Bhoopendra; Kedia, Shweta; Laythalling, Rajinder Kumar

2017-02-01

Meningocele is defined as a protrusion of the meninges through an opening in the skull or spinal column, forming a bulge or sac filled with cerebrospinal fluid. A pseudomeningocele is defined as a cerebrospinal fluid (CSF) collection formed due to escape of CSF through a dural defect with trapping of CSF into the surrounding soft tissues. We herby report rare occurrence of a large (pseudo)meningocele in a young patient with congenital skull base defect presenting as upper lateral neck swelling. We present the case of a 17-year-old boy who had painless progressive swelling right side of the upper neck without any history of meningitis or CSF leak. He had a history of undergoing cranioplasty using steel plates for nontraumatic boggy swelling right parieto-occipital region at the age of 5 years at another hospital. Clinical examination showed painless swelling right side of the upper neck, with positive cough impulse and transillumination. CT head with cisternography showed a large right skull base defect through which a large pseudomeningocele was herniating, thus producing upper neck swelling and compressing oral cavity. The neck swelling and intraoral bulge reduced in size after the coperitoneal shunt. Differential diagnosis of (pseudo)meningocele should be considered while evaluating a painless progressive upper neck swelling having cough impulse and transillumination in a young patient.

Relevance of Whitnall's tubercle and auditory meatus in diagnosing exclusions during skull-photo superimposition.

PubMed

Jayaprakash, Paul T; Hashim, Natassha; Yusop, Ridzuan Abd Aziz Mohd

2015-08-01

Video vision mixer based skull-photo superimposition is a popular method for identifying skulls retrieved from unidentified human remains. A report on the reliability of the superimposition method suggested increased failure rates of 17.3 to 32% to exclude and 15 to 20% to include skulls while using related and unrelated face photographs. Such raise in failures prompted an analysis of the methods employed for the research. The protocols adopted for assessing the reliability are seen to vary from those suggested by the practitioners in the field. The former include overlaying the skull- and face-images on the basis of morphology by relying on anthropometric landmarks on the front plane of the face-images and evaluating the goodness of match depending on mix-mode images; the latter consist of orienting the skull considering landmarks on both the eye and ear planes of the face- and skull-images and evaluating the match utilizing images seen in wipe-mode in addition to those in mix-mode. Superimposition of a skull with face-images of five living individuals in two sets of experiments, one following the procedure described for the research on reliability and the other applying the methods suggested by the practitioners has shown that overlaying the images on the basis of morphology depending on the landmarks on the front plane alone and assessing the match in mix-mode fails to exclude the skull. However, orienting the skull relying on the relationship between the anatomical landmarks on the skull- and face-images such as Whitnall's tubercle and exocanthus in the front (eye) plane and the porion and tragus in the rear (ear) plane as well as assessing the match using wipe-mode images enables excluding that skull while superimposing with the same set of face-images. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Skull Base Tumors

NASA Astrophysics Data System (ADS)

Schulz-Ertner, Daniela

In skull base tumors associated with a low radiosensitivity for conventional radiotherapy (RT), irradiation with proton or carbon ion beams facilitates a safe and accurate application of high tumor doses due to the favorable beam localization properties of these particle beams. Cranial nerves, the brain stem and normal brain tissue can at the same time be optimally spared.

Pre-reconstruction of cervical-to-petrous internal carotid artery: An improved technique for treatment of vascular lesions involving internal carotid artery at the lateral skull base.

PubMed

Li, Fang-Da; Gao, Zhi-Qiang; Ren, Hua-Liang; Liu, Chang-Wei; Song, Xiao-Jun; Li, Yan-Feng; Zheng, Yue-Hong

2016-04-01

Reconstruction of the internal carotid artery (ICA) is an operative challenge for lesions involving the lateral skull base because of excessive blood loss, intraoperative cranial nerve injury, and difficulties in cerebral protection. Between January 2010 and October 2014, 9 patients with vascular lesions at the lateral skull base were treated with a "pre-reconstruction" technique, which means reconstruction of the ICA in advance of excising the lesions. All operations were technically successful with no mortality or strokes. The mean blood loss was 921 ± 210 mL. The mean total clamping time was 18 ± 5 minutes. Among the 5 patients without invasion of specific cranial nerves, no long-term sequelae occurred during the follow-up period ranging from 11 to 54 months. With less blood loss, slighter cranial nerve injuries, and shorter clamping time, the "pre-reconstruction" technique was safe and effective for the treatment of vascular lesions at the lateral skull base. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1562-E1567, 2016. © 2016 Wiley Periodicals, Inc.

The transition from microscopic to endoscopic transsphenoidal surgery: the experience at Brigham and Women's Hospital.

PubMed

Laws, Edward R; Barkhoudarian, Garni

2014-12-01

As interest and enthusiasm for the use of the endoscope in transsphenoidal anterior skull base and pituitary surgery increases, neurosurgeons are increasingly adopting endoscopic technology and associated novel concepts. Often this involves a transition from the standard operating microscope as the main means of visualization to the operating endoscope (2D or 3D) during surgery. The authors' experience with this transition is described, including the rationale, advantages and disadvantages of the two surgical techniques. The successful use of endoscopic surgery for a large variety of pathological problems involving the anterior skull base and the pituitary region is presented. Perceived advantages for the patient and the surgeon are described, as is the occasional need for transition back to the microscopic approach. The endoscopic approach and its allied technology are here to stay. They are useful and occasionally preferable methods for treating a variety of suitable lesions involving the anterior skull base. The importance of incorporating the basic principles of skull base surgery is emphasized. Copyright © 2014 Elsevier Inc. All rights reserved.

Intraoperative Magnetic Resonance Imaging in Skull Base Surgery: A Review of 71 Consecutive Cases.

PubMed

Ashour, Ramsey; Reintjes, Stephen; Park, Michael S; Sivakanthan, Sananthan; van Loveren, Harry; Agazzi, Siviero

2016-09-01

Although intraoperative magnetic resonance imaging (iMRI) increasingly is used during glioma resection, its role in skull base surgery has not been well documented. In this study, we evaluate our experience with iMRI for skull base surgery. Medical records were reviewed retrospectively on all neurosurgical cases performed at our institution in the IMRIS iMRI suite between April 2014 and July 2015. During the study period, the iMRI suite was used for 71 skull base tumors. iMRI was performed in 23 of 71 cases. Additional tumor resection was pursued after scanning in 7 of 23 patients. There was a significant difference in procedure length between the scanned versus nonscanned groups, and this was likely attributable to a greater proportion of petroclival meningiomas in the scanned group. Further analyses revealed significant increases in procedure length for the following scanned subgroups: anterolateral approach, anterolateral and petroclival lesion locations, and meningiomas. The rate of non-neurologic complications was significantly greater in the scanned group, particularly for patients with tumors >3 cm. Despite the unique challenges associated with skull base tumor surgery, iMRI can be safely obtained while adding a modest although not prohibitive amount of time to the procedure. The immediate evidence of residual tumor with a patient still in position to have additional resection may influence the surgeon to alter the surgical plan and attempt further resection in a critical area. Copyright © 2016 Elsevier Inc. All rights reserved.

Preoperative Visualization of Cranial Nerves in Skull Base Tumor Surgery Using Diffusion Tensor Imaging Technology.

PubMed

Ma, Jun; Su, Shaobo; Yue, Shuyuan; Zhao, Yan; Li, Yonggang; Chen, Xiaochen; Ma, Hui

2016-01-01

To visualize cranial nerves (CNs) using diffusion tensor imaging (DTI) with special parameters. This study also involved the evaluation of preoperative estimates and intraoperative confirmation of the relationship between nerves and tumor by verifying the accuracy of visualization. 3T magnetic resonance imaging scans including 3D-FSPGR, FIESTA, and DTI were used to collect information from 18 patients with skull base tumor. DTI data were integrated into the 3D slicer for fiber tracking and overlapped anatomic images to determine course of nerves. 3D reconstruction of tumors was achieved to perform neighboring, encasing, and invading relationship between lesion and nerves. Optic pathway including the optic chiasm could be traced in cases of tuberculum sellae meningioma and hypophysoma (pituitary tumor). The oculomotor nerve, from the interpeduncular fossa out of the brain stem to supraorbital fissure, was clearly visible in parasellar meningioma cases. Meanwhile, cisternal parts of trigeminal nerve and abducens nerve, facial nerve were also imaged well in vestibular schwannomas and petroclival meningioma cases. The 3D-spatial relationship between CNs and skull base tumor estimated preoperatively by tumor modeling and tractography corresponded to the results determined during surgery. Supported by DTI and 3D slicer, preoperative 3D reconstruction of most CNs related to skull base tumor is feasible in pathological circumstances. We consider DTI Technology to be a useful tool for predicting the course and location of most CNs, and syntopy between them and skull base tumor.

Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement.

PubMed

Dröge, L H; Hinsche, T; Canis, M; Alt-Epping, B; Hess, C F; Wolff, H A

2014-02-01

Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting.

Multimodal navigated skull base tumor resection using image-based vascular and cranial nerve segmentation: A prospective pilot study

PubMed Central

Dolati, Parviz; Gokoglu, Abdulkerim; Eichberg, Daniel; Zamani, Amir; Golby, Alexandra; Al-Mefty, Ossama

2015-01-01

Background: Skull base tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal tumor resection with incomplete knowledge of patient anatomy remains a challenge. Methods: To determine the accuracy and utility of image-based preoperative segmentation in skull base tumor resections, we performed a prospective study. Ten patients with skull base tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured. Results: Strong correspondence between image-based segmentation and microscopic view was found at the surface of the tumor and tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases. Conclusion: Image-based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during skull base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients. PMID:26674155

Multimodal navigated skull base tumor resection using image-based vascular and cranial nerve segmentation: A prospective pilot study.

PubMed

Dolati, Parviz; Gokoglu, Abdulkerim; Eichberg, Daniel; Zamani, Amir; Golby, Alexandra; Al-Mefty, Ossama

2015-01-01

Skull base tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal tumor resection with incomplete knowledge of patient anatomy remains a challenge. To determine the accuracy and utility of image-based preoperative segmentation in skull base tumor resections, we performed a prospective study. Ten patients with skull base tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured. Strong correspondence between image-based segmentation and microscopic view was found at the surface of the tumor and tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases. Image-based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during skull base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients.

A New Baurusuchid (Crocodyliformes, Mesoeucrocodylia) from the Late Cretaceous of Brazil and the Phylogeny of Baurusuchidae

PubMed Central

Montefeltro, Felipe C.; Larsson, Hans C. E.; Langer, Max C.

2011-01-01

Background Baurusuchidae is a group of extinct Crocodyliformes with peculiar, dog-faced skulls, hypertrophied canines, and terrestrial, cursorial limb morphologies. Their importance for crocodyliform evolution and biogeography is widely recognized, and many new taxa have been recently described. In most phylogenetic analyses of Mesoeucrocodylia, the entire clade is represented only by Baurusuchus pachecoi, and no work has attempted to study the internal relationships of the group or diagnose the clade and its members. Methodology/Principal Findings Based on a nearly complete skull and a referred partial skull and lower jaw, we describe a new baurusuchid from the Vale do Rio do Peixe Formation (Bauru Group), Late Cretaceous of Brazil. The taxon is diagnosed by a suite of characters that include: four maxillary teeth, supratemporal fenestra with equally developed medial and anterior rims, four laterally visible quadrate fenestrae, lateral Eustachian foramina larger than medial Eustachian foramen, deep depression on the dorsal surface of pterygoid wing. The new taxon was compared to all other baurusuchids and their internal relationships were examined based on the maximum parsimony analysis of a discrete morphological data matrix. Conclusion The monophyly of Baurusuchidae is supported by a large number of unique characters implying an equally large morphological gap between the clade and its immediate outgroups. A complex phylogeny of baurusuchids was recovered. The internal branch pattern suggests two main lineages, one with a relatively broad geographical range between Argentina and Brazil (Pissarrachampsinae), which includes the new taxon, and an endemic clade of the Bauru Group in Brazil (Baurusuchinae). PMID:21765925

Anatomical features of skull base and oral cavity: a pilot study to determine the accessibility of the sella by transoral robotic-assisted surgery.

PubMed

Amelot, Aymeric; Trunet, Stephanie; Degos, Vincent; André, Olivier; Dionnet, Aurore; Cornu, Philippe; Hans, Stéphane; Chauvet, Dorian

2015-10-01

The role of transoral robotic surgery (TORS) in the skull base emerges and represents the natural progression toward miniinvasive resections in confined spaces. The accessibility of the sella via TORS has been recently described on fresh human cadavers. An anatomic study is mandatory to know if this approach would be feasible in the majority of patients regardless of their oral morphological features. From 30 skull base CT scans from patients who were asked to open their mouth as wide as they can, we measured specific dimensions of the oral cavity and the skull base, such as length of the palate, mouth opening and distance from the sella to the palate. All data were acquired on a sagittal midline plane and on a 25° rotation plane, which simulated the axis of the robotic instruments. Looking at the projection of the dental palatine line on the sella, we studied possible predictive factors of sellar accessibility and tried to bring objective data for surgical feasibility. We also proposed an angle α to study the working angle at the skull base. We observed that the maximal mouth opening was a good predictive factor of sellar accessibility by TORS (p < 0.05). The mouth aperture threshold value for a good sensitivity, over 80 %, was comparable to the mean value of mouth opening in our series, 38.9 and 39.4 mm respectively. Moreover, we showed a statistically significant increase of the working angle α at the skull base comparing the lateral access to the midline one (p < 0.05). This seemed to quantitatively demonstrate that the robotic arms placed at the labial commissure of the mouth can reach the sella. From these anatomical features and previous cadaveric dissections, we assume that TORS may be feasible on a majority of patients to remove pituitary adenomas.

The anterior interhemispheric approach: a safe and effective approach to anterior skull base lesions.

PubMed

Mielke, Dorothee; Mayfrank, Lothar; Psychogios, Marios Nikos; Rohde, Veit

2014-04-01

Many approaches to the anterior skull base have been reported. Frequently used are the pterional, the unilateral or bilateral frontobasal, the supraorbital and the frontolateral approach. Recently, endoscopic transnasal approaches have become more popular. The benefits of each approach has to be weighted against its complications and limitations. The aim of this study was to investigate if the anterior interhemispheric approach (AIA) could be a safe and effective alternative approach to tumorous and non-tumorous lesions of the anterior skull base. We screened the operative records of all patients with an anterior skull base lesion undergoing transcranial surgery. We have used the AIA in 61 patients. These were exclusively patients with either olfactory groove meningioma (OGM) (n = 43), ethmoidal dural arteriovenous fistula (dAVF) ( n = 6) or frontobasal fractures of the anterior midline with cerebrospinal fluid (CSF) leakage ( n = 12). Patient records were evaluated concerning accessibility of the lesion, realization of surgical aims (complete tumor removal, dAVF obliteration, closure of the dural tear), and approach related complications. The use of the AIA exclusively in OGMs, ethmoidal dAVFs and midline frontobasal fractures indicated that we considered lateralized frontobasal lesions not suitable to be treated successfully. If restricted to these three pathologies, the AIA is highly effective and safe. The surgical aim (complete tumor removal, complete dAVF occlusion, no rhinorrhea) was achieved in all patients. The complication rate was 11.5 % (wound infection (n = 2; 3.2 %), contusion of the genu of the corpus callosum, subdural hygroma, epileptic seizure, anosmia and asymptomatic bleed into the tumor cavity (n = 1 each). Only the contusion of the corpus callosum was directly related to the approach (1.6 %). Olfaction, if present before surgery, was preserved in all patients, except one (1.6 %). The AIA is an effective and a safe approach to tumorous, vascular and traumatic pathologies of the midline anterior skull base. This approach should be part of the armamentarium of skull base surgeons.

Properties and architecture of the sperm whale skull amphitheatre.

PubMed

Alam, Parvez; Amini, Shahrouz; Tadayon, Maryam; Miserez, Ali; Chinsamy, Anusuya

2016-02-01

The sperm whale skull amphitheatre cradles an enormous two-tonne spermaceti organ. The amphitheatre separates this organ from the cranium and the cervical vertebrae that lie in close proximity to the base of the skull. Here, we elucidate that this skull amphitheatre is an elastic, flexible, triple-layered structure with mechanical properties that are conjointly guided by bone histology and the characteristics of pore space. We contend that the amphitheatre will flex elastically to equilibrate forces transmitted via the spermaceti organ that arise through diving. We find that collisions from sperm whale aggression do not cause the amphitheatre to bend, but rather localise stress to the base of the amphitheatre on its anterior face. We consider, therefore, that the uniquely thin and extended construction of the amphitheatre, has relevance as an energy absorptive structure in diving. Copyright © 2015 Elsevier GmbH. All rights reserved.

Ultrashort echo-time MRI versus CT for skull aberration correction in MR-guided transcranial focused ultrasound: In vitro comparison on human calvaria.

PubMed

Miller, G Wilson; Eames, Matthew; Snell, John; Aubry, Jean-François

2015-05-01

Transcranial magnetic resonance-guided focused ultrasound (TcMRgFUS) brain treatment systems compensate for skull-induced beam aberrations by adjusting the phase and amplitude of individual ultrasound transducer elements. These corrections are currently calculated based on a preacquired computed tomography (CT) scan of the patient's head. The purpose of the work presented here is to demonstrate the feasibility of using ultrashort echo-time magnetic resonance imaging (UTE MRI) instead of CT to calculate and apply aberration corrections on a clinical TcMRgFUS system. Phantom experiments were performed in three ex-vivo human skulls filled with tissue-mimicking hydrogel. Each skull phantom was imaged with both CT and UTE MRI. The MR images were then segmented into "skull" and "not-skull" pixels using a computationally efficient, threshold-based algorithm, and the resulting 3D binary skull map was converted into a series of 2D virtual CT images. Each skull was mounted in the head transducer of a clinical TcMRgFUS system (ExAblate Neuro, Insightec, Israel), and transcranial sonications were performed using a power setting of approximately 750 acoustic watts at several different target locations within the electronic steering range of the transducer. Each target location was sonicated three times: once using aberration corrections calculated from the actual CT scan, once using corrections calculated from the MRI-derived virtual CT scan, and once without applying any aberration correction. MR thermometry was performed in conjunction with each 10-s sonication, and the highest single-pixel temperature rise and surrounding-pixel mean were recorded for each sonication. The measured temperature rises were ∼ 45% larger for aberration-corrected sonications than for noncorrected sonications. This improvement was highly significant (p < 10(-4)). The difference between the single-pixel peak temperature rise and the surrounding-pixel mean, which reflects the sharpness of the thermal focus, was also significantly larger for aberration-corrected sonications. There was no significant difference between the sonication results achieved using CT-based and MR-based aberration correction. The authors have demonstrated that transcranial focal heating can be significantly improved in vitro by using UTE MRI to compute skull-induced ultrasound aberration corrections. Their results suggest that UTE MRI could be used instead of CT to implement such corrections on current 0.7 MHz clinical TcMRgFUS devices. The MR image acquisition and segmentation procedure demonstrated here would add less than 15 min to a clinical MRgFUS treatment session.

[Skull base meningiomas: a predictive system to know the extent of their surgical resection and patient outcome].

PubMed

Morales, F; Maillo, A; Díaz-Alvarez, A; Merino, M; Muñoz-Herrera, A; Hernández, J; Santamarta, D

2005-12-01

The aim of this study was to build a preoperative predictive system which could provide reliable information about: 1 degrees which skull base meningiomas can be total or partially removed, and 2 degrees their surgical outcome. Patient histories and imaging data were reviewed retrospectively from 85 consecutive skull base meningiomas patients who underwent surgery from 1990 and 2002. From the preoperative data, nine variables were selected for conventional statistical analysis as regards their relationship with: 1 degrees total vs partial tumor resection and 2 degrees with patients outcome according to the degree of tumour removal. From the nine variables analysed only two had a statistical association with the type of tumour resection performed (total vs partial) and the patient outcome: 1) arteries encasement and 2) cranial nerves involvement. Upon correlating these two variables with the type of tumour resection performed (total vs partial) and with the Karnofsky'scale to evaluate patients surgical outcome, the following grading groups were identified: Grade I: skull base meningiomas which did not involve cranial nerves or artery or only encased one artery or one cranial nerve. In these cases the incidence of gross tumour resection was 98.3% (p< 0.0001) and the perspective to reach 70 points in the Karnofsky'scale was of 96.5% ( p=0.001). Grade II: skull base meningiomas which involved one cranial nerve and encased, at least, two main cerebral arteries. In these cases, the frequency of total resection, decreased to 83.3% (p<0.0001) and the probability to reach 70 points in the Karnofsky'scale was 70.6% (p=0.001). Grade III: skull base meningiomas which involved two or more cranial nerves and encased several arteries In this group, the frequency of a total resection was of 42.9% (p<0.0001) and the probability of reaching 70 points in the Karnofsky'scale was only 60% (p=0.001). We propose a preoperative grading system for skull base meningiomas that helps predicting both whether total or partial tumor removal will be achieved during surgery and the immediate postsurgical outcome of the patient. In applying this predictive system we will be able to reduce surgical morbidity, to advance the possibility of a radiosurgical treatment and give a more precise information to the patients and their families about our surgical decision-making process.

Congenital muscle dystrophy and diet consistency affect mouse skull shape differently.

PubMed

Spassov, Alexander; Toro-Ibacache, Viviana; Krautwald, Mirjam; Brinkmeier, Heinrich; Kupczik, Kornelius

2017-11-01

The bones of the mammalian skull respond plastically to changes in masticatory function. However, the extent to which muscle function affects the growth and development of the skull, whose regions have different maturity patterns, remains unclear. Using muscle dissection and 3D landmark-based geometric morphometrics we investigated the effect of changes in muscle function established either before or after weaning, on skull shape and muscle mass in adult mice. We compared temporalis and masseter mass and skull shape in mice with a congenital muscle dystrophy (mdx) and wild type (wt) mice fed on either a hard or a soft diet. We found that dystrophy and diet have distinct effects on the morphology of the skull and the masticatory muscles. Mdx mice show a flattened neurocranium with a more dorsally displaced foramen magnum and an anteriorly placed mandibular condyle compared with wt mice. Compared with hard diet mice, soft diet mice had lower masseter mass and a face with more gracile features as well as labially inclined incisors, suggesting reduced bite strength. Thus, while the early-maturing neurocranium and the posterior portion of the mandible are affected by the congenital dystrophy, the late-maturing face including the anterior part of the mandible responds to dietary differences irrespective of the mdx mutation. Our study confirms a hierarchical, tripartite organisation of the skull (comprising neurocranium, face and mandible) with a modular division based on development and function. Moreover, we provide further experimental evidence that masticatory loading is one of the main environmental stimuli that generate craniofacial variation. © 2017 Anatomical Society.

[Craniometrical study of the species complex of Meriones shawii-grandis (Mammalia: Rodentia) in Morocco, in Algeria and in Tunisia].

PubMed

Djelaila, Yassine; Denys, Christiane; Stoetzel, Emmanuelle; Cornette, Raphaël; Lalis, Aude; Adamou-Djerbaoui, Malika; Boukhemza, Mohamed

2018-01-01

In North Africa, the rodents of the species complex Meriones shawii-grandis have a considerable ecological, economic and epidemiological importance. Until now, the systematics of these species was subject to discussion due to the presence of populations displaying high morphological variability. By means of an approach of traditional morphometrics based on cranial distances and by using the method of the log shape-ratio, we attempt to characterize morphologically these two taxa. The results show significant differences in size and shape between the specimens of Morocco, on the one hand, and those of Algeria and Tunisia, on the other hand. The samples of Morocco that have been molecularly typed and attributed to M. grandis have larger tooth rows and narrower skulls, as well as relatively small tympanic bullae. On the other hand, those of Algeria and Tunisia assigned to M. shawii are characterized by small tooth rows and wide skulls with well-developed tympanic bullae. The morphological distance is relatively strong between both clades (79.5%), which corresponds to the molecular distance. However, the discriminant analysis performed after molecularly-typed specimens allows the correct classification of only 91.8% of the individuals. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

New Insights into the Skull of Istiodactylus latidens (Ornithocheiroidea, Pterodactyloidea)

PubMed Central

Witton, Mark P.

2012-01-01

The skull of the Cretaceous pterosaur Istiodactylus latidens, a historically important species best known for its broad muzzle of interlocking, lancet-shaped teeth, is almost completely known from the broken remains of several individuals, but the length of its jaws remains elusive. Estimates of I. latidens jaw length have been exclusively based on the incomplete skull of NHMUK R3877 and, perhaps erroneously, reconstructed by assuming continuation of its broken skull pieces as preserved in situ. Here, an overlooked jaw fragment of NHMUK R3877 is redescribed and used to revise the skull reconstruction of I. latidens. The new reconstruction suggests a much shorter skull than previously supposed, along with a relatively tall orbital region and proportionally slender maxilla, a feature documented in the early 20th century but ignored by all skull reconstructions of this species. These features indicate that the skull of I. latidens is particularly distinctive amongst istiodactylids and suggests greater disparity between I. latidens and I. sinensis than previously appreciated. A cladistic analysis of istiodactylid pterosaurs incorporating new predicted I. latidens skull metrics suggests Istiodactylidae is constrained to five species (Liaoxipterus brachyognathus, Lonchengpterus zhoai, Nurhachius ignaciobritoi, Istiodactylus latidens and Istiodactylus sinensis) defined by their distinctive dentition, but excludes the putative istiodactylids Haopterus gracilis and Hongshanopterus lacustris. Istiodactylus latidens, I. sinensis and Li. brachyognathus form an unresolved clade of derived istiodactylids, and the similarity of comparable remains of I. sinensis and Li. brachyognathus suggest further work into their taxonomy and classification is required. The new skull model of I. latidens agrees with the scavenging habits proposed for these pterosaurs, with much of their cranial anatomy converging on that of habitually scavenging birds. PMID:22470442

The amniote temporal roof and the diapsid origin of the turtle skull.

PubMed

Bever, G S; Lyson, Tyler R; Field, Daniel J; Bhullar, Bhart-Anjan S

2016-12-01

Fossils provide a glimpse into the architecturally complex origins of modern vertebrate body plans. One such origin that has been long debated is that of turtles. Although much attention has been directed toward the origin of the shell, the enigmatic evolution of the turtle skull and its anapsid temporal region has long clouded our understanding of reptile phylogeny. Two taxa, Eunotosaurus africanus and Pappochelys rosinae, were recently and independently described as long-anticipated stem turtles whose diapsid skulls would cement the evolutionary link between turtles and other modern reptile lineages. Detailed μCT analysis of the stratigraphically older and phylogenetically stemward of the two, Eunotosaurus, provides empirical insight into changing developmental trajectories that may have produced the anapsid cranial form of modern turtles and sets the stage for more comprehensive studies of early amniote cranial evolution. Copyright © 2016 Elsevier GmbH. All rights reserved.

Lesson to be remembered from a skull base tumor.

PubMed

Briet, C; Bernard, F; Rodien, P

2017-09-01

The natural history of giant prolactinomas is not known. While it is commonly accepted that the enlargement of microadenoma is rare and more limited than macroadenoma, it is so far uncommon that macroadenoma progress to giant adenoma. Thus, spontaneous enlargement of adenomas is poorly documented. We report the unusual history of undiagnosed microprolactinoma, revealed 12years later at the stage of a giant adenoma presenting as a skull base tumor. This unique observation provides information on the natural history of giant adenomas and arguments for particular attention to microadenomas with signs of invasion. Moreover, this clinical case highlights the need for a prolactin dosage for all midline skull base tumors. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

[Anatomy and imaging study of a new upper-agger nasi pathway of frontal sinus surgery].

PubMed

Liu, Zhixian; Li, Xiaohui; Wang, Peng; Yang, Gui; Li, Xingwei; Zhao, Peng

2014-10-01

To investigate the new surgical pathway of endoscopic frontal sinus surgery for frontal sinus lesions through the upper-agger nasi approach. The computed tomography (CT) scans from 32 patients were collected and subjected to three-dimensional reconstruction by Mimics. The distance in sagittal planes from anterior ethmoid artery to midpoint of axilla and to skull base attachment at anterior middle turbinate was measured. The distance in coronal planes between the perpendicular plate of middle turbinate and the orbital lamina was also detected as well as the height of agger nasi. Three-dimensional structures of the frontal sinus and its surrounding cells was reconstructed by Sinuses Trachea I software. We integrated the CT scans and the above data for simulating surgical operation on cadaveric heads. (1) Skull base attachment at anterior middle turbinate located at the anterior or posterior of aperture of frontal sinus. (2) The mean distance between anterior ethmoid artery and midpoint of axilla was (22.23 ± 2.78) mm on the left side and (22.30 ± 2.80) mm on right. The mean distance between anterior ethmoid artery and skull base attachment at anterior middle turbinate was (15.31 ± 2.82) mm on left and (15.39 ± 3.53) mm on right. The distance between perpendicular plate of middle turbinate and orbital lamina was (7.61 ± 1.34) mm on left and (7.80 ± 1.40) mm on right side. The height of the agger nasi was (8.33 ± 2.14) mm on left and (8.00 ± 2.57) mm on right. There was no statistical difference in the above data between left and right side (P > 0.05). (3) The visible three-dimensional structure showed that skull base attachment at the anterior middle turbinate was closely adjoined the aperture of frontal sinus, the space between sub-outer side of the attachment and orbital lamina, above the agger nasi cell or the upper area of the agger nasi cell was solely cell structures. Endoscopic frontal sinus surgery for frontal sinus lesions through the upper-agger nasi approach was practicable to solitary frontal sinus lesions and to solve the complex frontal sinus or frontal recess lesions by flexible operation according to the feature of the lesions.

[Anatomy of the skull].

PubMed

Pásztor, Emil

2010-01-01

The anatomy of the human body based on a special teleological system is one of the greatest miracles of the world. The skull's primary function is the defence of the brain, so every alteration or disease of the brain results in some alteration of the skull. This analogy is to be identified even in the human embryo. Proportions of the 22 bones constituting the skull and of sizes of sutures are not only the result of the phylogeny, but those of the ontogeny as well. E.g. the age of the skeletons in archaeological findings could be identified according to these facts. Present paper outlines the ontogeny and development of the tissues of the skull, of the structure of the bone-tissue, of the changes of the size of the skull and of its parts during the different periods of human life, reflecting to the aesthetics of the skull as well. "Only the human scull can give me an impression of beauty. In spite of all genetical colseness, a skull of a chimpanzee cannot impress me aesthetically"--author confesses. In the second part of the treatise those authors are listed, who contributed to the perfection of our knowledge regarding the skull. First of all the great founder of modern anatomy, Andreas Vesalius, then Pierre Paul Broca, Jacob Benignus Winslow are mentioned here. The most important Hungarian contributors were as follow: Sámuel Rácz, Pál Bugát or--the former assistant of Broca--Aurél Török. A widely used tool for measurement of the size of the skull, the craniometer was invented by the latter. The members of the family Lenhossék have had also important results in this field of research, while descriptive anatomy of the skull was completed by microsopical anatomy thanks the activity of Géza Mihálkovits.

Localized intraoperative virtual endoscopy (LIVE) for surgical guidance in 16 skull base patients.

PubMed

Haerle, Stephan K; Daly, Michael J; Chan, Harley; Vescan, Allan; Witterick, Ian; Gentili, Fred; Zadeh, Gelareh; Kucharczyk, Walter; Irish, Jonathan C

2015-01-01

Previous preclinical studies of localized intraoperative virtual endoscopy-image-guided surgery (LIVE-IGS) for skull base surgery suggest a potential clinical benefit. The first aim was to evaluate the registration accuracy of virtual endoscopy based on high-resolution magnetic resonance imaging under clinical conditions. The second aim was to implement and assess real-time proximity alerts for critical structures during skull base drilling. Patients consecutively referred for sinus and skull base surgery were enrolled in this prospective case series. Five patients were used to check registration accuracy and feasibility with the subsequent 11 patients being treated under LIVE-IGS conditions with presentation to the operating surgeon (phase 2). Sixteen skull base patients were endoscopically operated on by using image-based navigation while LIVE-IGS was tested in a clinical setting. Workload was quantitatively assessed using the validated National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire. Real-time localization of the surgical drill was accurate to ~1 to 2 mm in all cases. The use of 3-mm proximity alert zones around the carotid arteries and optic nerve found regular clinical use, as the median minimum distance between the tracked drill and these structures was 1 mm (0.2-3.1 mm) and 0.6 mm (0.2-2.5 mm), respectively. No statistical differences were found in the NASA-TLX indicators for this experienced surgical cohort. Real-time proximity alerts with virtual endoscopic guidance was sufficiently accurate under clinical conditions. Further clinical evaluation is required to evaluate the potential surgical benefits, particularly for less experienced surgeons or for teaching purposes. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array

DOE Office of Scientific and Technical Information (OSTI.GOV)

O’Reilly, Meaghan A., E-mail: moreilly@sri.utoront

Purpose: Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to themore » ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. Methods: A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. Results: The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). Conclusions: If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available.« less

Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array.

PubMed

O'Reilly, Meaghan A; Jones, Ryan M; Birman, Gabriel; Hynynen, Kullervo

2016-09-01

Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available.

Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array

PubMed Central

O’Reilly, Meaghan A.; Jones, Ryan M.; Birman, Gabriel; Hynynen, Kullervo

2016-01-01

Purpose: Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. Methods: A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. Results: The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). Conclusions: If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available. PMID:27587036

A QI Initiative to Reduce Hospitalization for Children With Isolated Skull Fractures.

PubMed

Lyons, Todd W; Stack, Anne M; Monuteaux, Michael C; Parver, Stephanie L; Gordon, Catherine R; Gordon, Caroline D; Proctor, Mark R; Nigrovic, Lise E

2016-06-01

Although children with isolated skull fractures rarely require acute interventions, most are hospitalized. Our aim was to safely decrease the hospitalization rate for children with isolated skull fractures. We designed and executed this multifaceted quality improvement (QI) initiative between January 2008 and July 2015 to reduce hospitalization rates for children ≤21 years old with isolated skull fractures at a single tertiary care pediatric institution. We defined an isolated skull fracture as a skull fracture without intracranial injury. The QI intervention consisted of 2 steps: (1) development and implementation of an evidence-based guideline, and (2) dissemination of a provider survey designed to reinforce guideline awareness and adherence. Our primary outcome was hospitalization rate and our balancing measure was hospital readmission within 72 hours. We used standard statistical process control methodology to assess change over time. To assess for secular trends, we examined admission rates for children with an isolated skull fracture in the Pediatric Health Information System administrative database. We identified 321 children with an isolated skull fracture with a median age of 11 months (interquartile range 5-16 months). The baseline admission rate was 71% (179/249, 95% confidence interval, 66%-77%) and decreased to 46% (34/72, 95% confidence interval, 35%-60%) after implementation of our QI initiative. No child was readmitted after discharge. The admission rate in our secular trend control group remained unchanged at 78%. We safely reduced the hospitalization rate for children with isolated skull fractures without an increase in the readmissions. Copyright © 2016 by the American Academy of Pediatrics.

The preprocessed connectomes project repository of manually corrected skull-stripped T1-weighted anatomical MRI data.

PubMed

Puccio, Benjamin; Pooley, James P; Pellman, John S; Taverna, Elise C; Craddock, R Cameron

2016-10-25

Skull-stripping is the procedure of removing non-brain tissue from anatomical MRI data. This procedure can be useful for calculating brain volume and for improving the quality of other image processing steps. Developing new skull-stripping algorithms and evaluating their performance requires gold standard data from a variety of different scanners and acquisition methods. We complement existing repositories with manually corrected brain masks for 125 T1-weighted anatomical scans from the Nathan Kline Institute Enhanced Rockland Sample Neurofeedback Study. Skull-stripped images were obtained using a semi-automated procedure that involved skull-stripping the data using the brain extraction based on nonlocal segmentation technique (BEaST) software, and manually correcting the worst results. Corrected brain masks were added into the BEaST library and the procedure was repeated until acceptable brain masks were available for all images. In total, 85 of the skull-stripped images were hand-edited and 40 were deemed to not need editing. The results are brain masks for the 125 images along with a BEaST library for automatically skull-stripping other data. Skull-stripped anatomical images from the Neurofeedback sample are available for download from the Preprocessed Connectomes Project. The resulting brain masks can be used by researchers to improve preprocessing of the Neurofeedback data, as training and testing data for developing new skull-stripping algorithms, and for evaluating the impact on other aspects of MRI preprocessing. We have illustrated the utility of these data as a reference for comparing various automatic methods and evaluated the performance of the newly created library on independent data.

[Development of a Striatal and Skull Phantom for Quantitative 123I-FP-CIT SPECT].

PubMed

Ishiguro, Masanobu; Uno, Masaki; Miyazaki, Takuma; Kataoka, Yumi; Toyama, Hiroshi; Ichihara, Takashi

123 Iodine-labelled N-(3-fluoropropyl) -2β-carbomethoxy-3β-(4-iodophenyl) nortropane ( 123 I-FP-CIT) single photon emission computerized tomography (SPECT) images are used for differential diagnosis such as Parkinson's disease (PD). Specific binding ratio (SBR) is affected by scattering and attenuation in SPECT imaging, because gender and age lead to changes in skull density. It is necessary to clarify and correct the influence of the phantom simulating the the skull. The purpose of this study was to develop phantoms that can evaluate scattering and attenuation correction. Skull phantoms were prepared based on the measuring the results of the average computed tomography (CT) value, average skull thickness of 12 males and 16 females. 123 I-FP-CIT SPECT imaging of striatal phantom was performed with these skull phantoms, which reproduced normal and PD. SPECT images, were reconstructed with scattering and attenuation correction. SBR with partial volume effect corrected (SBR act ) and conventional SBR (SBR Bolt ) were measured and compared. The striatum and the skull phantoms along with 123 I-FP-CIT were able to reproduce the normal accumulation and disease state of PD and further those reproduced the influence of skull density on SPECT imaging. The error rate with the true SBR, SBR act was much smaller than SBR Bolt . The effect on SBR could be corrected by scattering and attenuation correction even if the skull density changes with 123 I-FP-CIT on SPECT imaging. The combination of triple energy window method and CT-attenuation correction method would be the best correction method for SBR act .

Neomorphosis and heterochrony of skull shape in dog domestication.

PubMed

Geiger, Madeleine; Evin, Allowen; Sánchez-Villagra, Marcelo R; Gascho, Dominic; Mainini, Cornelia; Zollikofer, Christoph P E

2017-10-18

The overall similarity of the skull shape of some dog breeds with that of juvenile wolves begs the question if and how ontogenetic changes such as paedomorphosis (evolutionary juvenilisation) played a role in domestication. Here we test for changes in patterns of development and growth during dog domestication. We present the first geometric morphometric study using ontogenetic series of dog and wolf crania, and samples of dogs with relatively ancestral morphology and from different time periods. We show that patterns of juvenile-to-adult morphological change are largely similar in wolves and domestic dogs, but differ in two ways. First, dog skulls show unique (neomorphic) features already shortly after birth, and these features persist throughout postnatal ontogeny. Second, at any given age, juvenile dogs exhibit skull shapes that resemble those of consistently younger wolves, even in dog breeds that do not exhibit a 'juvenilized' morphology as adults. These patterns exemplify the complex nature of evolutionary changes during dog domestication: the cranial morphology of adult dogs cannot simply be explained as either neomorphic or paedomorphic. The key to our understanding of dog domestication may lie in a closer comparative examination of developmental phases.

Skull Bone Defects Reconstruction with Custom-Made Titanium Graft shaped with Electron Beam Melting Technology: Preliminary Experience in a Series of Ten Patients.

PubMed

Francaviglia, Natale; Maugeri, Rosario; Odierna Contino, Antonino; Meli, Francesco; Fiorenza, Vito; Costantino, Gabriele; Giammalva, Roberto Giuseppe; Iacopino, Domenico Gerardo

2017-01-01

Cranioplasty represents a challenge in neurosurgery. Its goal is not only plastic reconstruction of the skull but also to restore and preserve cranial function, to improve cerebral hemodynamics, and to provide mechanical protection of the neural structures. The ideal material for the reconstructive procedures and the surgical timing are still controversial. Many alloplastic materials are available for performing cranioplasty and among these, titanium still represents a widely proven and accepted choice. The aim of our study was to present our preliminary experience with a "custom-made" cranioplasty, using electron beam melting (EBM) technology, in a series of ten patients. EBM is a new sintering method for shaping titanium powder directly in three-dimensional (3D) implants. To the best of our knowledge this is the first report of a skull reconstruction performed by this technique. In a 1-year follow-up no postoperative complications have been observed and good clinical and esthetic outcomes were achieved. Costs higher than those for other types of titanium mesh, a longer production process, and the greater expertise needed for this technique are compensated by the achievement of most complex skull reconstructions with a shorter operative time.

Local phylogenetic divergence and global evolutionary convergence of skull function in reef fishes of the family Labridae.

PubMed

Westneat, Mark W; Alfaro, Michael E; Wainwright, Peter C; Bellwood, David R; Grubich, Justin R; Fessler, Jennifer L; Clements, Kendall D; Smith, Lydia L

2005-05-22

The Labridae is one of the most structurally and functionally diversified fish families on coral and rocky reefs around the world, providing a compelling system for examination of evolutionary patterns of functional change. Labrid fishes have evolved a diverse array of skull forms for feeding on prey ranging from molluscs, crustaceans, plankton, detritus, algae, coral and other fishes. The species richness and diversity of feeding ecology in the Labridae make this group a marine analogue to the cichlid fishes. Despite the importance of labrids to coastal reef ecology, we lack evolutionary analysis of feeding biomechanics among labrids. Here, we combine a molecular phylogeny of the Labridae with the biomechanics of skull function to reveal a broad pattern of repeated convergence in labrid feeding systems. Mechanically fast jaw systems have evolved independently at least 14 times from ancestors with forceful jaws. A repeated phylogenetic pattern of functional divergence in local regions of the labrid tree produces an emergent family-wide pattern of global convergence in jaw function. Divergence of close relatives, convergence among higher clades and several unusual 'breakthroughs' in skull function characterize the evolution of functional complexity in one of the most diverse groups of reef fishes.

Use of duraseal in repair of cerebrospinal fluid leaks.

PubMed

Chin, Christopher J; Kus, Lukas; Rotenberg, Brian W

2010-10-01

The purpose of our article is to review the use of the DuraSeal Sealant System (Confluent Surgical Inc., Waltham, MA) in the repair of complex cerebrospinal fluid (CSF) leaks in endoscopic skull-base surgery. Retrospective chart review. London Health Sciences Centre. A database of endoscopic skull-base cases between 2007 and 2009 that involved CSF leakage repaired with DuraSeal was created. Demographic data and operative reports were collected and analyzed qualitatively. Recurrence of CSF leak after repair. Five cases were identified that met study criteria. In four of the five cases, the repair was successful. There were no complications related to DuraSeal use. Comparison to a subset of patients using Tisseel Fibrin Sealant (Baxter, Toronto, ON) for repair did not show a significant difference in failure rate (χ2 = 0.029, p = .858). There are a variety of techniques described to repair CSF rhinorrhea, with various studies demonstrating the advantages of using tissue glues in CSF leak repairs. We used DuraSeal in five patients to enhance graft strength and form a watertight seal. The system was effective in the majority of patients. Our study is the first to report on endoscopic endonasal repair of CSF leaks using DuraSeal.

Pediatric Clival Chordoma: A Curable Disease that Conforms to Collins' Law.

PubMed

Rassi, Marcio S; Hulou, M Maher; Almefty, Kaith; Bi, Wenya Linda; Pravdenkova, Svetlana; Dunn, Ian F; Smith, Timothy R; Al-Mefty, Ossama

2018-05-01

Skull base chordomas in children are extremely rare. Their course, management, and outcome have not been defined. To describe the preeminent clinical and radiological features in a series of pediatric patients with skull base chordomas and analyze the outcome of a cohort who underwent uniform treatment. We emphasize predictors of overall survival and progression-free survival, which aligns with Collins' law for embryonal tumors. Thirty-one patients with a mean age of 10.7 yr (range 0.8-22) harboring skull base chordomas were evaluated. We retrospectively analyzed the outcomes and prognostic factors for 18 patients treated by the senior author, with uniform management of surgery with the aim of gross total resection and adjuvant proton-beam radiotherapy. Mean follow-up was 119.2 mo (range 8-263). Abducens nerve palsy was the most common presenting symptom. Imaging disclosed large tumors that often involve multiple anatomical compartments. Patients undergoing gross total resection had significantly increased progression-free survival (P = .02) and overall survival (P = .05) compared with those having subtotal resection. Those who lived through the period of risk for recurrence without disease progression had a higher probability of living entirely free of progression (P = .03; odds ratio = 16.0). Age, sex, and histopathological variant did not yield statistical significance in survival. Long-term overall and progression-free survival in children harboring skull base chordomas can be achieved with gross surgical resection and proton-beam radiotherapy, despite an advanced stage at presentation. Collins' law does apply to pediatric skull base chordomas, and children with this disease have a high hope for cure.

Safety of drilling for clinoidectomy and optic canal unroofing in anterior skull base surgery.

PubMed

Spektor, Sergey; Dotan, Shlomo; Mizrahi, Cezar José

2013-06-01

Skull base drilling is a necessary and important element of skull base surgery; however, drilling around vulnerable neurovascular structures has certain risks. We aimed to assess the frequency of complications related to drilling the anterior skull base in the area of the optic nerve (ON) and internal carotid artery (ICA), in a large series of patients. We included anterior skull base surgeries performed from 2000 to 2012 that demanded unroofing of the optic canal, with extra- or intradural clinoidectomy and/or drilling of the clinoidal process and lateral aspect of the tuberculum sella. Data was retrieved from a prospective database and supplementary retrospective file review. Our IRB waived the requirement for informed consent. The nature and location of pathology, clinical presentation, surgical techniques, surgical morbidity and mortality, pre- and postoperative vision, and neurological outcomes were reviewed. There were 205 surgeries, including 22 procedures with bilateral optic canal unroofing (227 optic canals unroofed). There was no mortality, drilling-related vascular damage, or brain trauma. Complications possibly related to drilling included CSF leak (6 patients, 2.9 %), new ipsilateral blindness (3 patients, 1.5 %), visual deterioration (3 patients, 1.5 %), and transient oculomotor palsy (5 patients, 2.4 %). In all patients with new neuropathies, the optic and oculomotor nerves were manipulated during tumor removal; thus, new deficits could have resulted from drilling, or tumor dissection, or both. Drilling of the clinoid process and tuberculum sella, and optic canal unroofing are important surgical techniques, which may be performed relatively safely by a skilled neurosurgeon.

Severe skull base osteomyelitis caused by Pseudomonas aeruginosa with successful outcome after prolonged outpatient therapy with continuous infusion of ceftazidime and oral ciprofloxacin: a case report.

PubMed

Conde-Díaz, Cristina; Llenas-García, Jara; Parra Grande, Mónica; Terol Esclapez, Gertrudis; Masiá, Mar; Gutiérrez, Félix

2017-02-21

Skull base osteomyelitis is an uncommon disease that usually complicates a malignant external otitis with temporal bone involvement. It affects predominantly diabetic and immunocompromised males and has a high mortality rate. Pseudomonas aeruginosa is the most common causative organism. Currently, there is no consensus about the best therapeutic option. Here we describe a case of severe skull base osteomyelitis caused by Pseudomonas aeruginosa with progressive palsy of cranial nerves that was successfully managed with prolonged outpatient continuous infusion of ceftazidime plus oral ciprofloxacin. A 69-year-old Caucasian man presented with dysphagia, headache, and weight loss. He complained of left earache and purulent otorrhea. Over the following weeks he developed progressive palsy of IX, X, VI, and XII cranial nerves and papilledema. A petrous bone computed tomography scan showed a mass in the left jugular foramen with a strong lytic component that expanded to the cavum. A biopsy was then performed and microbiological cultures grew Pseudomonas aeruginosa. After 6 weeks of parenteral antibiotic treatment, our patient was discharged and treatment was continued with a domiciliary continuous infusion of a beta-lactam through a peripherally inserted central catheter, along with an oral fluoroquinolone for 10 months. Both radiological and clinical responses were excellent. Skull base osteomyelitis is a life-threating condition; clinical suspicion and correct microbiological identification are key to achieve an accurate and timely diagnosis. Due to the poor outcome of Pseudomonas aeruginosa skull base osteomyelitis, prolonged outpatient parenteral antibiotic therapy administered by continuous infusion could be a valuable option for these patients.

Endoscopic Endonasal Anterior Skull Base Surgery: A Systematic Review of Complications During the Past 65 Years.

PubMed

Borg, Anouk; Kirkman, Matthew A; Choi, David

2016-11-01

Endoscopic skull base surgery is becoming more popular as an approach to the anterior skull base for tumors and cerebrospinal fluid (CSF) fistulae. It offers the advantages of better cosmesis and improved quality of life after surgery. We reviewed the complication rates reported in the literature. A literature search was performed in the electronic database Ovid MEDLINE (1950 to August 25, 2015) with the search item "([Anterior] AND Skull base surgery) AND endoscopic." We identified 82 relevant studies that included 7460 cases. An average overall complication rate of 17.1% (range 0%-68.0%) and a mortality rate of 0.4% (0%-10.0%) were demonstrated in a total of 82 studies that included 7460 cases. The average CSF leak rate for all studies was 8.9% (0%-40.0%) with meningiomas and clival lesions having the greatest CSF leak rates. The most frequent benign pathology encountered was pituitary adenomas (n = 3720, 49.8% of all cases) and the most frequent malignant tumor was esthesioneuroblastoma (n = 120, 1.6% of all cases). Studies that included only CSF fistula repairs had a lower average total complication rate (12.9%) but a greater rate of meningitis compared with studies that reported mixed pathology (2.4% vs. 1.3%). A trend towards a lower total complication rate with increasing study size was observed. The endoscopic approach is an increasingly accepted technique for anterior skull base tumor surgery and is associated with acceptable complication rates. Increasing experience with this technique can decrease rates of complications. Copyright © 2016 Elsevier Inc. All rights reserved.

Predicting variation in subject thermal response during transcranial magnetic resonance guided focused ultrasound surgery: Comparison in seventeen subject datasets.

PubMed

Vyas, Urvi; Ghanouni, Pejman; Halpern, Casey H; Elias, Jeff; Pauly, Kim Butts

2016-09-01

In transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) treatments, the acoustic and spatial heterogeneity of the skull cause reflection, absorption, and scattering of the acoustic beams. These effects depend on skull-specific parameters and can lead to patient-specific thermal responses to the same transducer power. In this work, the authors develop a simulation tool to help predict these different experimental responses using 3D heterogeneous tissue models based on the subject CT images. The authors then validate and compare the predicted skull efficiencies to an experimental metric based on the subject thermal responses during tcMRgFUS treatments in a dataset of seventeen human subjects. Seventeen human head CT scans were used to create tissue acoustic models, simulating the effects of reflection, absorption, and scattering of the acoustic beam as it propagates through a heterogeneous skull. The hybrid angular spectrum technique was used to model the acoustic beam propagation of the InSightec ExAblate 4000 head transducer for each subject, yielding maps of the specific absorption rate (SAR). The simulation assumed the transducer was geometrically focused to the thalamus of each subject, and the focal SAR at the target was used as a measure of the simulated skull efficiency. Experimental skull efficiency for each subject was calculated using the thermal temperature maps from the tcMRgFUS treatments. Axial temperature images (with no artifacts) were reconstructed with a single baseline, corrected using a referenceless algorithm. The experimental skull efficiency was calculated by dividing the reconstructed temperature rise 8.8 s after sonication by the applied acoustic power. The simulated skull efficiency using individual-specific heterogeneous models predicts well (R(2) = 0.84) the experimental energy efficiency. This paper presents a simulation model to predict the variation in thermal responses measured in clinical ctMRGFYS treatments while being computationally feasible.

Predicting variation in subject thermal response during transcranial magnetic resonance guided focused ultrasound surgery: Comparison in seventeen subject datasets

PubMed Central

Vyas, Urvi; Ghanouni, Pejman; Halpern, Casey H.; Elias, Jeff; Pauly, Kim Butts

2016-01-01

Purpose: In transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) treatments, the acoustic and spatial heterogeneity of the skull cause reflection, absorption, and scattering of the acoustic beams. These effects depend on skull-specific parameters and can lead to patient-specific thermal responses to the same transducer power. In this work, the authors develop a simulation tool to help predict these different experimental responses using 3D heterogeneous tissue models based on the subject CT images. The authors then validate and compare the predicted skull efficiencies to an experimental metric based on the subject thermal responses during tcMRgFUS treatments in a dataset of seventeen human subjects. Methods: Seventeen human head CT scans were used to create tissue acoustic models, simulating the effects of reflection, absorption, and scattering of the acoustic beam as it propagates through a heterogeneous skull. The hybrid angular spectrum technique was used to model the acoustic beam propagation of the InSightec ExAblate 4000 head transducer for each subject, yielding maps of the specific absorption rate (SAR). The simulation assumed the transducer was geometrically focused to the thalamus of each subject, and the focal SAR at the target was used as a measure of the simulated skull efficiency. Experimental skull efficiency for each subject was calculated using the thermal temperature maps from the tcMRgFUS treatments. Axial temperature images (with no artifacts) were reconstructed with a single baseline, corrected using a referenceless algorithm. The experimental skull efficiency was calculated by dividing the reconstructed temperature rise 8.8 s after sonication by the applied acoustic power. Results: The simulated skull efficiency using individual-specific heterogeneous models predicts well (R2 = 0.84) the experimental energy efficiency. Conclusions: This paper presents a simulation model to predict the variation in thermal responses measured in clinical ctMRGFYS treatments while being computationally feasible. PMID:27587047

Predicting variation in subject thermal response during transcranial magnetic resonance guided focused ultrasound surgery: Comparison in seventeen subject datasets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vyas, Urvi, E-mail: urvi.vyas@gmail.com; Ghanouni,

Purpose: In transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) treatments, the acoustic and spatial heterogeneity of the skull cause reflection, absorption, and scattering of the acoustic beams. These effects depend on skull-specific parameters and can lead to patient-specific thermal responses to the same transducer power. In this work, the authors develop a simulation tool to help predict these different experimental responses using 3D heterogeneous tissue models based on the subject CT images. The authors then validate and compare the predicted skull efficiencies to an experimental metric based on the subject thermal responses during tcMRgFUS treatments in a dataset of seventeen humanmore » subjects. Methods: Seventeen human head CT scans were used to create tissue acoustic models, simulating the effects of reflection, absorption, and scattering of the acoustic beam as it propagates through a heterogeneous skull. The hybrid angular spectrum technique was used to model the acoustic beam propagation of the InSightec ExAblate 4000 head transducer for each subject, yielding maps of the specific absorption rate (SAR). The simulation assumed the transducer was geometrically focused to the thalamus of each subject, and the focal SAR at the target was used as a measure of the simulated skull efficiency. Experimental skull efficiency for each subject was calculated using the thermal temperature maps from the tcMRgFUS treatments. Axial temperature images (with no artifacts) were reconstructed with a single baseline, corrected using a referenceless algorithm. The experimental skull efficiency was calculated by dividing the reconstructed temperature rise 8.8 s after sonication by the applied acoustic power. Results: The simulated skull efficiency using individual-specific heterogeneous models predicts well (R{sup 2} = 0.84) the experimental energy efficiency. Conclusions: This paper presents a simulation model to predict the variation in thermal responses measured in clinical ctMRGFYS treatments while being computationally feasible.« less

Mirror-Imaged Rapid Prototype Skull Model and Pre-Molded Synthetic Scaffold to Achieve Optimal Orbital Cavity Reconstruction.

PubMed

Park, Sung Woo; Choi, Jong Woo; Koh, Kyung S; Oh, Tae Suk

2015-08-01

Reconstruction of traumatic orbital wall defects has evolved to restore the original complex anatomy with the rapidly growing use of computer-aided design and prototyping. This study evaluated a mirror-imaged rapid prototype skull model and a pre-molded synthetic scaffold for traumatic orbital wall reconstruction. A single-center retrospective review was performed of patients who underwent orbital wall reconstruction after trauma from 2012 to 2014. Patients were included by admission through the emergency department after facial trauma or by a tertiary referral for post-traumatic orbital deformity. Three-dimensional (3D) computed tomogram-based mirror-imaged reconstruction images of the orbit and an individually manufactured rapid prototype skull model by a 3D printing technique were obtained for each case. Synthetic scaffolds were anatomically pre-molded using the skull model as guide and inserted at the individual orbital defect. Postoperative complications were assessed and 3D volumetric measurements of the orbital cavity were performed. Paired samples t test was used for statistical analysis. One hundred four patients with immediate orbital defect reconstructions and 23 post-traumatic orbital deformity reconstructions were included in this study. All reconstructions were successful without immediate postoperative complications, although there were 10 cases with mild enophthalmos and 2 cases with persistent diplopia. Reoperations were performed for 2 cases of persistent diplopia and secondary touchup procedures were performed to contour soft tissue in 4 cases. Postoperative volumetric measurement of the orbital cavity showed nonsignificant volume differences between the damaged orbit and the reconstructed orbit (21.35 ± 1.93 vs 20.93 ± 2.07 cm(2); P = .98). This protocol was extended to severe cases in which more than 40% of the orbital frame was lost and combined with extensive soft tissue defects. Traumatic orbital reconstruction can be optimized and successful using an individually manufactured rapid prototype skull model and a pre-molded synthetic scaffold by computer-aid design and manufacturing. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Pervasive genetic integration directs the evolution of human skull shape.

PubMed

Martínez-Abadías, Neus; Esparza, Mireia; Sjøvold, Torstein; González-José, Rolando; Santos, Mauro; Hernández, Miquel; Klingenberg, Christian Peter

2012-04-01

It has long been unclear whether the different derived cranial traits of modern humans evolved independently in response to separate selection pressures or whether they resulted from the inherent morphological integration throughout the skull. In a novel approach to this issue, we combine evolutionary quantitative genetics and geometric morphometrics to analyze genetic and phenotypic integration in human skull shape. We measured human skulls in the ossuary of Hallstatt (Austria), which offer a unique opportunity because they are associated with genealogical data. Our results indicate pronounced covariation of traits throughout the skull. Separate simulations of selection for localized shape changes corresponding to some of the principal derived characters of modern human skulls produced outcomes that were similar to each other and involved a joint response in all of these traits. The data for both genetic and phenotypic shape variation were not consistent with the hypothesis that the face, cranial base, and cranial vault are completely independent modules but relatively strongly integrated structures. These results indicate pervasive integration in the human skull and suggest a reinterpretation of the selective scenario for human evolution where the origin of any one of the derived characters may have facilitated the evolution of the others. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Comparison of Scientific Calipers and Computer-Enabled CT Review for the Measurement of Skull Base and Craniomaxillofacial Dimensions

PubMed Central

Citardi, Martin J.; Herrmann, Brian; Hollenbeak, Chris S.; Stack, Brendan C.; Cooper, Margaret; Bucholz, Richard D.

2001-01-01

Traditionally, cadaveric studies and plain-film cephalometrics provided information about craniomaxillofacial proportions and measurements; however, advances in computer technology now permit software-based review of computed tomography (CT)-based models. Distances between standardized anatomic points were measured on five dried human skulls with standard scientific calipers (Geneva Gauge, Albany, NY) and through computer workstation (StealthStation 2.6.4, Medtronic Surgical Navigation Technology, Louisville, CO) review of corresponding CT scans. Differences in measurements between the caliper and CT model were not statistically significant for each parameter. Measurements obtained by computer workstation CT review of the cranial skull base are an accurate representation of actual bony anatomy. Such information has important implications for surgical planning and clinical research. ImagesFigure 1Figure 2Figure 3 PMID:17167599

The endonasal endoscopic harvest and anatomy of the buccal fat pad flap for closure of skull base defects.

PubMed

Markey, Jeff; Benet, Arnau; El-Sayed, Ivan H

2015-10-01

Extirpation via expanded endonasal approaches (EEA) to the skull base can result in defects requiring vascularized rotational flap reconstruction. The buccal fat pad (BFP) is a vascularized graft described in open skull base resections, but its harvest and adequacy of vascular supply have not been examined for use with EEA. A transfacial cadaveric dissection was carried forth in a latex-injected specimen to characterize the BFP blood supply. Then a cadaveric dissection series was performed involving the endoscopic harvest and rotation of 10 buccal fat pads in five cadaveric specimens to assess defect coverage. An endoscopic medial maxillectomy combined with an anterior maxillotomy was performed prior to endoscopic harvest in cadaveric specimens. The BFP was rotated to assess its capability to reconstruct seven possible ventral skull base defects. Finally, the BFP vascular anatomy was further characterized following harvest and transposition. The BFP reconstructed defects at the greater sphenoid wing, inferior and superior clivus, sella, planum, and bilateral ethmoids in all cadaveric specimens. In some cases it covered two sites concurrently. The BFP pedicled rotational flap is a potential alternate flap following EEA in select cases. NA © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Ex vivo optimisation of a heterogeneous speed of sound model of the human skull for non-invasive transcranial focused ultrasound at 1 MHz.

PubMed

Marsac, L; Chauvet, D; La Greca, R; Boch, A-L; Chaumoitre, K; Tanter, M; Aubry, J-F

2017-09-01

Transcranial brain therapy has recently emerged as a non-invasive strategy for the treatment of various neurological diseases, such as essential tremor or neurogenic pain. However, treatments require millimetre-scale accuracy. The use of high frequencies (typically ≥1 MHz) decreases the ultrasonic wavelength to the millimetre scale, thereby increasing the clinical accuracy and lowering the probability of cavitation, which improves the safety of the technique compared with the use of low-frequency devices that operate at 220 kHz. Nevertheless, the skull produces greater distortions of high-frequency waves relative to low-frequency waves. High-frequency waves require high-performance adaptive focusing techniques, based on modelling the wave propagation through the skull. This study sought to optimise the acoustical modelling of the skull based on computed tomography (CT) for a 1 MHz clinical brain therapy system. The best model tested in this article corresponded to a maximum speed of sound of 4000 m.s -1 in the skull bone, and it restored 86% of the optimal pressure amplitude on average in a collection of six human skulls. Compared with uncorrected focusing, the optimised non-invasive correction led to an average increase of 99% in the maximum pressure amplitude around the target and an average decrease of 48% in the distance between the peak pressure and the selected target. The attenuation through the skulls was also assessed within the bandwidth of the transducers, and it was found to vary in the range of 10 ± 3 dB at 800 kHz and 16 ± 3 dB at 1.3 MHz.

Preoperative Embolization of Skull Base Meningiomas: Outcomes in the Onyx Era.

PubMed

Przybylowski, Colin J; Baranoski, Jacob F; See, Alfred P; Flores, Bruno C; Almefty, Rami O; Ding, Dale; Chapple, Kristina M; Sanai, Nader; Ducruet, Andrew F; Albuquerque, Felipe C

2018-05-09

Preoperative embolization may facilitate skull base meningioma resection, but its safety and efficacy in the Onyx era have not been investigated. In this retrospective cohort study, we evaluated the outcomes of preoperative embolization of skull base meningiomas using Onyx as the primary embolysate. We queried an endovascular database for patients with skull base meningiomas who underwent preoperative embolization at our institution in 2007-2017. Patient, tumor, procedure, and outcome data were analyzed. Twenty-eight patients (28 meningiomas) underwent successful preoperative meningioma embolization. The mean patient age ± SD was 56 ± 13 years, and 18 patients (64%) were women. The mean tumor size was 49 cm 3 . There were 1, 2, or 3 arterial pedicles embolized in 21 cases (75%), 6 cases (21%), and 1 case (4%), respectively. The embolized pedicles included branches of the middle meningeal artery in 19 cases (68%), the internal maxillary artery in 8 cases (29%), the ascending pharyngeal artery in 2 cases (7%), and the posterior auricular, ophthalmic, occipital, and anterior cerebral arteries in 1 case each (4%). The embolysates used were Onyx alone in 20 cases (71%), n-butyl cyanoacrylate alone in 3 cases (11%), coils/particles and Onyx/n-butyl cyanoacrylate in 2 cases each (7%), and Onyx and coils in 1 case (4%). The median degree of tumor devascularization was 60%. Significant neurologic morbidity occurred in 1 patient (4%) who developed symptomatic peritumoral edema after Onyx embolization. For appropriately selected skull base meningiomas supplied by dura mater-based arterial pedicles without distal cranial nerve supply, preoperative embolization with current embolysate technology affords substantial tumor devascularization with a low complication rate. Copyright © 2018 Elsevier Inc. All rights reserved.

Earliest Directly-Dated Human Skull-Cups

PubMed Central

Bello, Silvia M.; Parfitt, Simon A.; Stringer, Chris B.

2011-01-01

Background The use of human braincases as drinking cups and containers has extensive historic and ethnographic documentation, but archaeological examples are extremely rare. In the Upper Palaeolithic of western Europe, cut-marked and broken human bones are widespread in the Magdalenian (∼15 to 12,000 years BP) and skull-cup preparation is an element of this tradition. Principal Findings Here we describe the post-mortem processing of human heads at the Upper Palaeolithic site of Gough's Cave (Somerset, England) and identify a range of modifications associated with the production of skull-cups. New analyses of human remains from Gough's Cave demonstrate the skilled post-mortem manipulation of human bodies. Results of the research suggest the processing of cadavers for the consumption of body tissues (bone marrow), accompanied by meticulous shaping of cranial vaults. The distribution of cut-marks and percussion features indicates that the skulls were scrupulously 'cleaned' of any soft tissues, and subsequently modified by controlled removal of the facial region and breakage of the cranial base along a sub-horizontal plane. The vaults were also ‘retouched’, possibly to make the broken edges more regular. This manipulation suggests the shaping of skulls to produce skull-cups. Conclusions Three skull-cups have been identified amongst the human bones from Gough's Cave. New ultrafiltered radiocarbon determinations provide direct dates of about 14,700 cal BP, making these the oldest directly dated skull-cups and the only examples known from the British Isles. PMID:21359211

Autogenous Bone Reconstruction of Large Secondary Skull Defects.

PubMed

Fearon, Jeffrey A; Griner, Devan; Ditthakasem, Kanlaya; Herbert, Morley

2017-02-01

The authors sought to ascertain the upper limits of secondary skull defect size amenable to autogenous reconstructions and to examine outcomes of a surgical series. Published data for autogenous and alloplastic skull reconstructions were also examined to explore associations that might guide treatment. A retrospective review of autogenously reconstructed secondary skull defects was undertaken. A structured literature review was also performed to assess potential differences in reported outcomes between autogenous bone and synthetic alloplastic skull reconstructions. Weighted risks were calculated for statistical testing. Ninety-six patients underwent autogenous skull reconstruction for an average defect size of 93 cm (range, 4 to 506 cm) at a mean age of 12.9 years. The mean operative time was 3.4 hours, 2 percent required allogeneic blood transfusions, and the average length of stay was less than 3 days. The mean length of follow-up was 28 months. There were no postoperative infections requiring surgery, but one patient underwent secondary grafting for partial bone resorption. An analysis of 34 studies revealed that complications, infections, and reoperations were more commonly reported with alloplastic than with autogenous reconstructions (relative risk, 1.57, 4.8, and 1.48, respectively). Autogenous reconstructions are feasible, with minimal associated morbidity, for patients with skull defect sizes as large as 500 cm. A structured literature review suggests that autogenous bone reconstructions are associated with lower reported infection, complication, and reoperation rates compared with synthetic alloplasts. Based on these findings, surgeons might consider using autogenous reconstructions even for larger skull defects. Therapeutic, IV.

Flow-diverter in radiation-induced skull base carotid blowout syndrome: do not write it off!

PubMed

Anil, Gopinathan; Zhang, Junwei; Ong, Yew Kwang; Hui, Francis

2017-10-01

Post-radiotherapy carotid blowout syndrome (CBS) of the skull base is a rare but often catastrophic complication of head and neck malignancies. The existing literature on the treatment of this condition with flow-diverting devices (FDD) is extremely limited and disappointing. We present a case of impending CBS in a patient previously irradiated for nasopharyngeal cancer that was successfully treated with use of multiple FDDs, adjunctive endonasal packing and delayed reinforcement with pedicled naso-septal flap, yielding an excellent outcome at 14-months follow-up. Notwithstanding the discouraging results in literature, our anecdotal experience suggests that endovascular reconstruction using FDD could be an option with long-term viability in post-radiotherapy CBS involving the skull base when reinforced with a vascularised naso-septal flap.

Brown tumors of the anterior skull base as the initial manifestation of true normocalcemic primary hyperparathyroidism: report of three cases and review of the literature.

PubMed

Khalatbari, Mahmoud Reza; Hamidi, Mehrdokht; Moharamzad, Yashar; Setayesh, Ali; Amirjamshidi, Abbas

2013-01-01

Brown tumor is a bone lesion secondary to hyperparathyroidism of various etiologies. Skeletal involvement in primary hyperparathyroidism secondary to parathyroid adenoma is very uncommon and brown tumor has become extremely a rare clinical entity. Hyperparathyroidism is usually associated with high levels of serum calcium. Brown tumor as the only and initial symptom of normocalcemic primary hyperparathyroidism is extremely rare. Moreover, involvement of the skull base and the orbit is exceedingly rare. The authors would report three cases of brown tumor of the anterior skull base that were associated with true normocalcemic primary hyperparathyroidism. Clinical manifestations, neuroimaging findings, pathological findings, diagnosis and treatment of the patients are discussed and the relevant literature is reviewed.

Intraoperative neurophysiological monitoring during endoscopic endonasal surgery for pediatric skull base tumors.

PubMed

Elangovan, Cheran; Singh, Supriya Palwinder; Gardner, Paul; Snyderman, Carl; Tyler-Kabara, Elizabeth C; Habeych, Miguel; Crammond, Donald; Balzer, Jeffrey; Thirumala, Parthasarathy D

2016-02-01

OBJECT The aim of this study was to evaluate the value of intraoperative neurophysiological monitoring (IONM) using electromyography (EMG), brainstem auditory evoked potentials (BAEPs), and somatosensory evoked potentials (SSEPs) to predict and/or prevent postoperative neurological deficits in pediatric patients undergoing endoscopic endonasal surgery (EES) for skull base tumors. METHODS All consecutive pediatric patients with skull base tumors who underwent EES with at least 1 modality of IONM (BAEP, SSEP, and/or EMG) at our institution between 1999 and 2013 were retrospectively reviewed. Staged procedures and repeat procedures were identified and analyzed separately. To evaluate the diagnostic accuracy of significant free-run EMG activity, the prevalence of cranial nerve (CN) deficits and the sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS A total of 129 patients underwent 159 procedures; 6 patients had a total of 9 CN deficits. The incidences of CN deficits based on the total number of nerves monitored in the groups with and without significant free-run EMG activity were 9% and 1.5%, respectively. The incidences of CN deficits in the groups with 1 staged and more than 1 staged EES were 1.5% and 29%, respectively. The sensitivity, specificity, and negative predictive values (with 95% confidence intervals) of significant EMG to detect CN deficits in repeat procedures were 0.55 (0.22-0.84), 0.86 (0.79-0.9), and 0.97 (0.92-0.99), respectively. Two patients had significant changes in their BAEPs that were reversible with an increase in mean arterial pressure. CONCLUSIONS IONM can be applied effectively and reliably during EES in children. EMG monitoring is specific for detecting CN deficits and can be an effective guide for dissecting these procedures. Triggered EMG should be elicited intraoperatively to check the integrity of the CNs during and after tumor resection. Given the anatomical complexity of pediatric EES and the unique challenges encountered, multimodal IONM can be a valuable adjunct to these procedures.

Simulation of bone-conducted sound transmission in a three-dimensional finite-element model of a human skull

NASA Astrophysics Data System (ADS)

Chang, You; Kim, Namkeun; Stenfelt, Stefan

2015-12-01

Bone conduction (BC) is the transmission of sound to the inner ear through the bones of the skull. This type of transmission is used in humans fitted with BC hearing aids as well as to classify between conductive and sensorineural hearing losses. The objective of the present study is to develop a finite-element (FE) model of the human skull based on cryosectional images of a female cadaver head in order to gain better understanding of the sound transmission. Further, the BC behavior was validated in terms of sound transmission against experimental data published in the literature. Results showed the responses of the simulated skull FE model were consistent with the experimentally reported data.

The role of various structures in the head on the formation of the biosonar beam of the baiji (Lipotes vexillifer).

PubMed

Wei, Chong; Au, Whitlow W L; Song, Zhongchang; Zhang, Yu

2016-02-01

The relative role of the various structures in the head of the baiji (Lipotes vexillifer) is examined. A finite element approach was applied to numerically simulate the acoustic propagation through a dolphin's head to examine the relative role of the skull, air sacs, and melon in the formation of the biosonar beam in the vertical plane. The beam pattern obtained with the whole head in place is compared with the beam pattern when the air sac is removed and the other structures (skull and melon) are in place, with only the skull removed, and finally with only the melon removed. The beam pattern with the air sacs and skull intact and the melon removed closely resembled the beam pattern for the complete head, suggesting that the melon has a minor role in the formation of the beam. The beam pattern for the other two cases had very little resemblance to the beam pattern for the whole head. The air sacs seem to have a role of directing propagation of the signal toward the front and the skull prevents the sound propagating below the rostrum. The beam patterns along with a correlation analysis showed that the melon had only a slight influence on the shape and direction of the beam. The resultant beam exiting the head of the dolphin is the result of complex reflection processes within the head of the animal.

Arterial supply of the upper cranial nerves: a comprehensive review.

PubMed

Hendrix, Philipp; Griessenauer, Christoph J; Foreman, Paul; Shoja, Mohammadali M; Loukas, Marios; Tubbs, R Shane

2014-11-01

The arterial supply to the upper cranial nerves is derived from a complex network of branches derived from the anterior and posterior cerebral circulations. We performed a comprehensive literature review of the arterial supply of the upper cranial nerves with an emphasis on clinical considerations. Arteries coursing in close proximity to the cranial nerves regularly give rise to small vessels that supply the nerve. Knowledge of the arteries supplying the cranial nerves is of particular importance during surgical approaches to the skull base. © 2014 Wiley Periodicals, Inc.

Chordoma of the Head and Neck: A Review.

PubMed

Wasserman, Jason K; Gravel, Denis; Purgina, Bibianna

2018-06-01

Chordoma is a rare malignant bone tumor that can arise anywhere along the central neural axis and many involve head and neck sites, most commonly the skull base. The relative rarity of these tumors, combined with the complex anatomy of the head and neck, pose diagnostic challenges to pathologists. This article describes the pertinent clinical, pathologic, and molecular features of chordomas and describes how these features can be used to aid in formulating a differential diagnosis. Emphasis is placed on key diagnostic pitfalls and the importance of incorporating immunohistochemical information into the diagnosis.

Readability analysis of internet-based patient information regarding skull base tumors.

PubMed

Misra, Poonam; Kasabwala, Khushabu; Agarwal, Nitin; Eloy, Jean Anderson; Liu, James K

2012-09-01

Readability is an important consideration in assessing healthcare-related literature. In order for a source of information to be the most beneficial to patients, it should be written at a level appropriate for the audience. The National Institute of Health recommends that health literature be written at a maximum level of sixth grade. This is not uniformly found in current health literature, putting patients with lower reading levels at a disadvantage. In February 2012, healthcare-oriented education resources were retrieved from websites obtained using the Google search phrase skull base tumors. Of the first 25 consecutive, unique website hits, 18 websites were found to contain information for patients. Ten different assessment scales were utilized to assess the readability of the patient-specific web pages. Patient-oriented material found online for skull base tumors was written at a significantly higher level than the reading level of the average US patient. The average reading level of this material was found to be at a minimum of eleventh grade across all ten scales. Health related material related to skull base tumors available through the internet can be improved to reach a larger audience without sacrificing the necessary information. Revisions of this material can provide significant benefit for average patients and improve their health care.

Clinical efficacy and safety of surface imaging guided radiosurgery (SIG-RS) in the treatment of benign skull base tumors.

PubMed

Lau, Steven K M; Patel, Kunal; Kim, Teddy; Knipprath, Erik; Kim, Gwe-Ya; Cerviño, Laura I; Lawson, Joshua D; Murphy, Kevin T; Sanghvi, Parag; Carter, Bob S; Chen, Clark C

2017-04-01

Frameless, surface imaging guided radiosurgery (SIG-RS) is a novel platform for stereotactic radiosurgery (SRS) wherein patient positioning is monitored in real-time through infra-red camera tracking of facial topography. Here we describe our initial clinical experience with SIG-RS for the treatment of benign neoplasms of the skull base. We identified 48 patients with benign skull base tumors consecutively treated with SIG-RS at a single institution between 2009 and 2011. Patients were diagnosed with meningioma (n = 22), vestibular schwannoma (n = 20), or nonfunctional pituitary adenoma (n = 6). Local control and treatment-related toxicity were retrospectively assessed. Median follow-up was 65 months (range 61-72 months). Prescription doses were 12-13 Gy in a single fraction (n = 18), 8 Gy × 3 fractions (n = 6), and 5 Gy × 5 fractions (n = 24). Actuarial tumor control rate at 5 years was 98%. No grade ≥3 treatment-related toxicity was observed. Grade ≤2 toxicity was associated with symptomatic lesions (p = 0.049) and single fraction treatment (p = 0.005). SIG-RS for benign skull base tumors produces clinical outcomes comparable to conventional frame-based SRS techniques while enhancing patient comfort.

The First AO Classification System for Fractures of the Craniomaxillofacial Skeleton: Rationale, Methodological Background, Developmental Process, and Objectives

PubMed Central

Audigé, Laurent; Cornelius, Carl-Peter; Ieva, Antonio Di; Prein, Joachim

2014-01-01

Validated trauma classification systems are the sole means to provide the basis for reliable documentation and evaluation of patient care, which will open the gateway to evidence-based procedures and healthcare in the coming years. With the support of AO Investigation and Documentation, a classification group was established to develop and evaluate a comprehensive classification system for craniomaxillofacial (CMF) fractures. Blueprints for fracture classification in the major constituents of the human skull were drafted and then evaluated by a multispecialty group of experienced CMF surgeons and a radiologist in a structured process during iterative agreement sessions. At each session, surgeons independently classified the radiological imaging of up to 150 consecutive cases with CMF fractures. During subsequent review meetings, all discrepancies in the classification outcome were critically appraised for clarification and improvement until consensus was reached. The resulting CMF classification system is structured in a hierarchical fashion with three levels of increasing complexity. The most elementary level 1 simply distinguishes four fracture locations within the skull: mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). Levels 2 and 3 focus on further defining the fracture locations and for fracture morphology, achieving an almost individual mapping of the fracture pattern. This introductory article describes the rationale for the comprehensive AO CMF classification system, discusses the methodological framework, and provides insight into the experiences and interactions during the evaluation process within the core groups. The details of this system in terms of anatomy and levels are presented in a series of focused tutorials illustrated with case examples in this special issue of the Journal. PMID:25489387

The First AO Classification System for Fractures of the Craniomaxillofacial Skeleton: Rationale, Methodological Background, Developmental Process, and Objectives.

PubMed

Audigé, Laurent; Cornelius, Carl-Peter; Di Ieva, Antonio; Prein, Joachim

2014-12-01

Validated trauma classification systems are the sole means to provide the basis for reliable documentation and evaluation of patient care, which will open the gateway to evidence-based procedures and healthcare in the coming years. With the support of AO Investigation and Documentation, a classification group was established to develop and evaluate a comprehensive classification system for craniomaxillofacial (CMF) fractures. Blueprints for fracture classification in the major constituents of the human skull were drafted and then evaluated by a multispecialty group of experienced CMF surgeons and a radiologist in a structured process during iterative agreement sessions. At each session, surgeons independently classified the radiological imaging of up to 150 consecutive cases with CMF fractures. During subsequent review meetings, all discrepancies in the classification outcome were critically appraised for clarification and improvement until consensus was reached. The resulting CMF classification system is structured in a hierarchical fashion with three levels of increasing complexity. The most elementary level 1 simply distinguishes four fracture locations within the skull: mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). Levels 2 and 3 focus on further defining the fracture locations and for fracture morphology, achieving an almost individual mapping of the fracture pattern. This introductory article describes the rationale for the comprehensive AO CMF classification system, discusses the methodological framework, and provides insight into the experiences and interactions during the evaluation process within the core groups. The details of this system in terms of anatomy and levels are presented in a series of focused tutorials illustrated with case examples in this special issue of the Journal.

Occipital condyle syndrome secondary to bone metastases from rectal cancer.

PubMed

Marruecos, J; Conill, C; Valduvieco, I; Vargas, M; Berenguer, J; Maurel, J

2008-01-01

Skull-base metastases are very unfrequent. Occipital condyle syndrome (OCS) is usually underdiagnosed. Until now few cases have been reported in the literature. We present a 71-year-old woman with metastatic rectum adenocarcinoma, with right occipital headache and ipsilateral hypoglossal palsy, diagnosed by computed tomography and magnetic resonance imaging of OCS due to a skull-base metastasis and treated with radiation therapy.

Transorbital and transnasal endoscopic repair of a meningoencephalocele.

PubMed

Schaberg, Madeleine; Murchison, Ann P; Rosen, Marc R; Evans, James J; Bilyk, Jurij R

2011-10-01

A 71-year-old female with a history of thyroid eye disease (TED) presented for evaluation of a skull base mass noted on neuroimaging. She had previously undergone bilateral orbital decompressions and strabismus surgery and had no neurologic symptoms. Successful resection of the menigoencephalocele and repair of the skull base defect was performed through a combined transnasal endoscopic and transorbital approach, obviating the need for craniotomy.

Quantitative and qualitative 5-aminolevulinic acid–induced protoporphyrin IX fluorescence in skull base meningiomas

PubMed Central

Bekelis, Kimon; Valdés, Pablo A.; Erkmen, Kadir; Leblond, Frederic; Kim, Anthony; Wilson, Brian C.; Harris, Brent T.; Paulsen, Keith D.; Roberts, David W.

2011-01-01

Object Complete resection of skull base meningiomas provides patients with the best chance for a cure; however, surgery is frequently difficult given the proximity of lesions to vital structures, such as cranial nerves, major vessels, and venous sinuses. Accurate discrimination between tumor and normal tissue is crucial for optimal tumor resection. Qualitative assessment of protoporphyrin IX (PpIX) fluorescence following the exogenous administration of 5-aminolevulinic acid (ALA) has demonstrated utility in malignant glioma resection but limited use in meningiomas. Here the authors demonstrate the use of ALA-induced PpIX fluorescence guidance in resecting a skull base meningioma and elaborate on the advantages and disadvantages provided by both quantitative and qualitative fluorescence methodologies in skull base meningioma resection. Methods A 52-year-old patient with a sphenoid wing WHO Grade I meningioma underwent tumor resection as part of an institutional review board–approved prospective study of fluorescence-guided resection. A surgical microscope modified for fluorescence imaging was used for the qualitative assessment of visible fluorescence, and an intraoperative probe for in situ fluorescence detection was utilized for quantitative measurements of PpIX. The authors assessed the detection capabilities of both the qualitative and quantitative fluorescence approaches. Results The patient harboring a sphenoid wing meningioma with intraorbital extension underwent radical resection of the tumor with both visibly and nonvisibly fluorescent regions. The patient underwent a complete resection without any complications. Some areas of the tumor demonstrated visible fluorescence. The quantitative probe detected neoplastic tissue better than the qualitative modified surgical microscope. The intraoperative probe was particularly useful in areas that did not reveal visible fluorescence, and tissue from these areas was confirmed as tumor following histopathological analysis. Conclusions Fluorescence-guided resection may be a useful adjunct in the resection of skull base meningiomas. The use of a quantitative intraoperative probe to detect PpIX concentration allows more accurate determination of neoplastic tissue in meningiomas than visible fluorescence and is readily applicable in areas, such as the skull base, where complete resection is critical but difficult because of the vital structures surrounding the pathology. PMID:21529179

A PCA-Based method for determining craniofacial relationship and sexual dimorphism of facial shapes.

PubMed

Shui, Wuyang; Zhou, Mingquan; Maddock, Steve; He, Taiping; Wang, Xingce; Deng, Qingqiong

2017-11-01

Previous studies have used principal component analysis (PCA) to investigate the craniofacial relationship, as well as sex determination using facial factors. However, few studies have investigated the extent to which the choice of principal components (PCs) affects the analysis of craniofacial relationship and sexual dimorphism. In this paper, we propose a PCA-based method for visual and quantitative analysis, using 140 samples of 3D heads (70 male and 70 female), produced from computed tomography (CT) images. There are two parts to the method. First, skull and facial landmarks are manually marked to guide the model's registration so that dense corresponding vertices occupy the same relative position in every sample. Statistical shape spaces of the skull and face in dense corresponding vertices are constructed using PCA. Variations in these vertices, captured in every principal component (PC), are visualized to observe shape variability. The correlations of skull- and face-based PC scores are analysed, and linear regression is used to fit the craniofacial relationship. We compute the PC coefficients of a face based on this craniofacial relationship and the PC scores of a skull, and apply the coefficients to estimate a 3D face for the skull. To evaluate the accuracy of the computed craniofacial relationship, the mean and standard deviation of every vertex between the two models are computed, where these models are reconstructed using real PC scores and coefficients. Second, each PC in facial space is analysed for sex determination, for which support vector machines (SVMs) are used. We examined the correlation between PCs and sex, and explored the extent to which the choice of PCs affects the expression of sexual dimorphism. Our results suggest that skull- and face-based PCs can be used to describe the craniofacial relationship and that the accuracy of the method can be improved by using an increased number of face-based PCs. The results show that the accuracy of the sex classification is related to the choice of PCs. The highest sex classification rate is 91.43% using our method. Copyright © 2017 Elsevier Ltd. All rights reserved.

Can skull form predict the shape of the temporomandibular joint? A study using geometric morphometrics on the skulls of wolves and domestic dogs.

PubMed

Curth, Stefan; Fischer, Martin S; Kupczik, Kornelius

2017-11-01

The temporomandibular joint (TMJ) conducts and restrains masticatory movements between the mammalian cranium and the mandible. Through this functional integration, TMJ morphology in wild mammals is strongly correlated with diet, resulting in a wide range of TMJ variations. However, in artificially selected and closely related domestic dogs, dietary specialisations between breeds can be ruled out as a diversifying factor although they display an enormous variation in TMJ morphology. This raises the question of the origin of this variation. Here we hypothesise that, even in the face of reduced functional demands, TMJ shape in dogs can be predicted by skull form; i.e. that the TMJ is still highly integrated in the dog skull. If true, TMJ variation in the dog would be a plain by-product of the enormous cranial variation in dogs and its genetic causes. We addressed this hypothesis using geometric morphometry on a data set of 214 dog and 60 wolf skulls. We digitized 53 three-dimensional landmarks of the skull and the TMJ on CT-based segmentations and compared (1) the variation between domestic dog and wolf TMJs (via principal component analysis) and (2) the pattern of covariation of skull size, flexion and rostrum length with TMJ shape (via regression of centroid size on shape and partial least squares analyses). We show that the TMJ in domestic dogs is significantly more diverse than in wolves: its shape covaries significantly with skull size, flexion and rostrum proportions in patterns which resemble those observed in primates. Similar patterns in canids, which are carnivorous, and primates, which are mostly frugivorous imply the existence of basic TMJ integration patterns which are independent of dietary adaptations. However, only limited amounts of TMJ variation in dogs can be explained by simple covariation with overall skull geometry. This implies that the final TMJ shape is gained partially independently of the rest of the skull. Copyright © 2017 Elsevier GmbH. All rights reserved.

Endoscopic Endonasal Approach in Skull Base Chondrosarcoma Associated with Maffucci Syndrome: Case Series and Literature Review.

PubMed

Beer-Furlan, André; Balsalobre, Leonardo; Vellutini, Eduardo A S; Stamm, Aldo C

2016-01-01

Maffucci syndrome is a nonhereditary disorder in which patients develop multiple enchondromas and cutaneous, visceral, or soft tissue hemangiomas. The potential malignant progression of enchondroma into a secondary chondrosarcoma is a well-known fact. Nevertheless, chondrosarcoma located at the skull base in patients with Maffuci syndrome is a very rare condition, with only 18 cases reported in the literature. We report 2 other cases successfully treated through an expanded endoscopic endonasal approach and discuss the condition based on the literature review. Skull base chondrosarcoma associated with Maffucci syndrome is a rare condition. The disease cannot be cured, therefore surgical treatment should be performed in symptomatic patients aiming for maximal tumor resection with function preservation. The endoscopic endonasal approach is a safe and reliable alternative for the management of these tumors. Copyright © 2016 Elsevier Inc. All rights reserved.

Surgical management of hydrocephalic dementia in Paget's disease of bone: the 6-year outcome of ventriculo-peritoneal shunting.

PubMed

Roohi, Fereydoon; Mann, David; Kula, Roger W

2005-06-01

Paget's disease of bone is a chronic progressive skeletal disorder usually occurring in the long bones and skull of older adults and elderly persons. In the skull, softening of the skull base may lead to basilar impression and consequently obstruction of the cerebrospinal fluid through the basilar cisterns, resulting ventricular enlargement in association with gait difficulties, incontinence and dementia: a syndrome resembling normal pressure hydrocephalus. The optimal management of hydrocephalus associated with Paget's disease of the skull is not well documented and is still debated. We report a patient with hydrocephalic dementia linked to Paget's disease of the skull who showed marked sustained improvement in her neurological condition after ventriculo-peritoneal shunt insertion. We have now followed this patient for 6 years. Our experience supports the view that ventricular shunting is the procedure of choice for treating hydrocephalus linked to the Paget's disease of bone and is best carried out in the early stages of the illness.

Non-Invasive Transcranial Brain Therapy Guided by CT Scans: an In Vivo Monkey Study

NASA Astrophysics Data System (ADS)

Marquet, F.; Pernot, M.; Aubry, J.-F.; Montaldo, G.; Tanter, M.; Boch, A.-L.; Kujas, M.; Seilhean, D.; Fink, M.

2007-05-01

Brain therapy using focused ultrasound remains very limited due to the strong aberrations induced by the skull. A minimally invasive technique using time-reversal was validated recently in-vivo on 20 sheeps. But such a technique requires a hydrophone at the focal point for the first step of the time-reversal procedure. A completely noninvasive therapy requires a reliable model of the acoustic properties of the skull in order to simulate this first step. 3-D simulations based on high-resolution CT images of a skull have been successfully performed with a finite differences code developed in our Laboratory. Thanks to the skull porosity, directly extracted from the CT images, we reconstructed acoustic speed, density and absorption maps and performed the computation. Computed wavefronts are in good agreement with experimental wavefronts acquired through the same part of the skull and this technique was validated in-vitro in the laboratory. A stereotactic frame has been designed and built in order to perform non invasive transcranial focusing in vivo. Here we describe all the steps of our new protocol, from the CT-scans to the therapy treatment and the first in vivo results on a monkey will be presented. This protocol is based on protocols already existing in radiotherapy.

Is there a role for conventional MRI and MR diffusion-weighted imaging for distinction of skull base chordoma and chondrosarcoma?

PubMed

Müller, Uta; Kubik-Huch, Rahel A; Ares, Carmen; Hug, Eugen B; Löw, Roland; Valavanis, Antonios; Ahlhelm, Frank J

2016-02-01

Chordoma and chondrosarcoma are locally invasive skull base tumors with similar clinical symptoms and anatomic imaging features as reported in the literature. To determine differentiation of chordoma and chondrosarcoma of the skull base with conventional magnetic resonance imaging (cMRI) and diffusion-weighted MR imaging (DWI) in comparison to histopathological diagnosis. This retrospective study comprised 96 (chordoma, n = 64; chondrosarcoma, n = 32) patients with skull base tumors referred to the Paul Scherrer Institute (PSI) for proton therapy. cMRI signal intensities of all tumors were investigated. In addition, median apparent diffusion coefficient (ADC) values were measured in a subgroup of 19 patients (chordoma, n = 11; chondrosarcoma, n = 8). The majority 81.2% (26/32) of chondrosarcomas displayed an off-midline growth pattern, 18.8% (6/32) showed clival invasion, 18.8% (6/32) were located more centrally. Only 4.7% (3/64) of chordomas revealed a lateral clival origin. Using cMRI no significant differences in MR signal intensities were observed in contrast to significantly different ADC values (subgroup of 19/96 patients examined by DWI), with the highest mean value of 2017.2 × 10(-6 )mm(2)/s (SD, 139.9( )mm(2)/s) for chondrosarcoma and significantly lower value of 1263.5 × 10(-6 )mm(2)/s (SD, 100.2 × 10(-6 )mm(2)/s) for chordoma (P = 0.001/median test). An off-midline growth pattern can differentiate chondrosarcoma from chordoma on cMRI in a majority of patients. Additional DWI is a promising tool for the differentiation of these skull base tumors. © The Foundation Acta Radiologica 2015.

Early Stage olfactory neuroblastoma and the impact of resecting dura and olfactory bulb.

PubMed

Mays, Ashley C; Bell, Diana; Ferrarotto, Renata; Phan, Jack; Roberts, Dianna; Fuller, Clifton D; Frank, Steven J; Raza, Shaan M; Kupferman, Michael E; DeMonte, Franco; Hanna, Ehab Y; Su, Shirley Y

2018-06-01

Compare outcomes of patients with olfactory neuroblastoma (ONB) without skull base involvement treated with and without resection of the dura and olfactory bulb. Retrospective review of ONB patients treated from 1992 to 2013 at the MD Anderson Cancer Center (The University of Texas, Houston, Texas, U.S.A.). Primary outcomes were overall and disease-free survival. Thirty-five patients were identified. Most patients had Kadish A/B. tumors (97%), Hyams grade 2 (70%), with unilateral involvement (91%), and arising from the nasal cavity (68%). Tumor involved the mucosa abutting the skull base in 42% of patients. Twenty-five patients (71%) received surgery and radiation, whereas the remainder had surgery alone. Five patients (14%) had bony skull base resection, and eight patients (23%) had resection of bony skull base, dura, and olfactory bulb. Surgical margins were grossly positive in one patient (3%) and microscopically positive in four patients (12%). The 5- and 10-year overall survival were 93% and 81%, respectively. The 5- and 10-year disease-free survival (DFS) were 89% and 78%, respectively. Bony cribriform plate resection was associated with better DFS (P = 0.05), but dura and olfactory bulb resection was not (P = 0.11). There was a trend toward improved DFS in patients with negative resection margins (P = 0.19). Surgical modality (open vs. endoscopic) and postoperative radiotherapy did not impact DFS. Most Kadish A/B ONB tumors have low Hyams grade, unilateral involvement, and favorable survival outcomes. Resection of the dura and olfactory bulb is not oncologically advantageous in patients without skull base involvement who are surgically treated with negative resection margins and cribriform resection. 4. Laryngoscope, 128:1274-1280, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Proton beam therapy in the management of skull base chordomas: systematic review of indications, outcomes, and implications for neurosurgeons.

PubMed

Matloob, Samir A; Nasir, Haleema A; Choi, David

2016-08-01

Chordomas are rare tumours affecting the skull base. There is currently no clear consensus on the post-surgical radiation treatments that should be used after maximal tumour resection. However, high-dose proton beam therapy is an accepted option for post-operative radiotherapy to maximise local control, and in the UK, National Health Service approval for funding abroad is granted for specific patient criteria. To review the indications and efficacy of proton beam therapy in the management of skull base chordomas. The primary outcome measure for review was the efficacy of proton beam therapy in the prevention of local occurrence. A systematic review of English and non-English articles using MEDLINE (1946-present) and EMBASE (1974-present) databases was performed. Additional studies were reviewed when referenced in other studies and not available on these databases. Search terms included chordoma or chordomas. The PRISMA guidelines were followed for reporting our findings as a systematic review. A total of 76 articles met the inclusion and exclusion criteria for this review. Limitations included the lack of documentation of the extent of primary surgery, tumour size, and lack of standardised outcome measures. Level IIb/III evidence suggests proton beam therapy given post operatively for skull base chordomas results in better survival with less damage to surrounding tissue. Proton beam therapy is a grade B/C recommended treatment modality for post-operative radiation therapy to skull base chordomas. In comparison to other treatment modalities long-term local control and survival is probably improved with proton beam therapy. Further, studies are required to directly compare proton beam therapy to other treatment modalities in selected patients.

Radio-anatomical analysis of the pericranial flap "money box approach" for ventral skull base reconstruction.

PubMed

Santamaría, Alfonso; Langdon, Cristóbal; López-Chacon, Mauricio; Cordero, Arturo; Enseñat, Joaquim; Carrau, Ricardo; Bernal-Sprekelsen, Manuel; Alobid, Isam

2017-11-01

To evaluate the versatility of the pericranial flap (PCF) to reconstruct the ventral skull base, using the frontal sinus as a gate for its passage into the sinonasal corridor "money box approach." Anatomic-radiological study and case series. Various approaches and their respective defects (cribriform, transtuberculum, clival, and craniovertebral junction) were completed in 10 injected specimens. The PCF was introduced into the nose through the uppermost portion of the frontal sinus (money box approach). Computed tomography (CT) scans (n = 50) were used to measure the dimensions of the PCF and the skull base defects. The vertical projection of the external ear canal was used as the reference point to standardize the incisions for the PCF. The surface area and maximum length of the PCF were 121.5 ± 19.4 cm 2 and 18.3 ± 1.3 cm, respectively. Using CT scans, we determined that to reconstruct defects secondary to transcribriform, transtuberculum, clival, and craniovertebral approaches, the PCF distal incision must be placed respectively at -3.7 ± 2.0 cm (angle -17.4 ± 8.5°), -0.2 ± 2.0 cm (angle -1.0 ± 9.3°), +5.5 ± 2.3 cm (angle +24.4 ± 9.7°), +8.4 ± 2.4 cm (angle +36.6 ± 11.5°), as related to the reference point. Skull base defects in our clinical cohort (n = 6) were completely reconstructed uneventfully with the PCF. The PCF renders enough surface area to reconstruct all possible defects in the ventral and median skull base. Using the uppermost frontal sinus as a gateway into the nose (money box approach) is feasible and simple. NA. Laryngoscope, 127:2482-2489, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

First Application of 7-T Magnetic Resonance Imaging in Endoscopic Endonasal Surgery of Skull Base Tumors.

PubMed

Barrett, Thomas F; Dyvorne, Hadrien A; Padormo, Francesco; Pawha, Puneet S; Delman, Bradley N; Shrivastava, Raj K; Balchandani, Priti

2017-07-01

Successful endoscopic endonasal surgery for the resection of skull base tumors is reliant on preoperative imaging to delineate pathology from the surrounding anatomy. The increased signal-to-noise ratio afforded by 7-T MRI can be used to increase spatial and contrast resolution, which may lend itself to improved imaging of the skull base. In this study, we apply a 7-T imaging protocol to patients with skull base tumors and compare the images with clinical standard of care. Images were acquired at 7 T on 11 patients with skull base lesions. Two neuroradiologists evaluated clinical 1.5-, 3-, and 7-T scans for detection of intracavernous cranial nerves and internal carotid artery (ICA) branches. Detection rates were compared. Images were used for surgical planning and uploaded to a neuronavigation platform and used to guide surgery. Image analysis yielded improved detection rates of cranial nerves and ICA branches at 7 T. The 7-T images were successfully incorporated into preoperative planning and intraoperative neuronavigation. Our study represents the first application of 7-T MRI to the full neurosurgical workflow for endoscopic endonasal surgery. We detected higher rates of cranial nerves and ICA branches at 7-T MRI compared with 3- and 1.5-T MRI, and found that integration of 7 T into surgical planning and guidance was feasible. These results suggest a potential for 7-T MRI to reduce surgical complications. Future studies comparing standardized 7-, 3-, and 1.5-T MRI protocols in a larger number of patients are warranted to determine the relative benefit of 7-T MRI for endonasal endoscopic surgical efficacy. Copyright © 2017 Elsevier Inc. All rights reserved.

First Application of 7T Magnetic Resonance Imaging in Endoscopic Endonasal Surgery of Skull Base Tumors

PubMed Central

Barrett, Thomas F; Dyvorne, Hadrien A; Padormo, Francesco; Pawha, Puneet S; Delman, Bradley N; Shrivastava, Raj K; Balchandani, Priti

2018-01-01

Background Successful endoscopic endonasal surgery for the resection of skull base tumors is reliant on preoperative imaging to delineate pathology from the surrounding anatomy. The increased signal-to-noise ratio afforded by 7T MRI can be used to increase spatial and contrast resolution, which may lend itself to improved imaging of skull base. In this study, we apply a 7T imaging protocol to patients with skull base tumors and compare the images to clinical standard of care. Methods Images were acquired at 7T on 11 patients with skull base lesions. Two neuroradiologists evaluated clinical 1.5T, 3T, and 7T scans for detection of intracavernous cranial nerves and ICA branches. Detection rates were compared. Images were utilized for surgical planning and uploaded to a neuronavigation platform and used to guide surgery. Results Image analysis yielded improved detection rates of cranial nerves and ICA branches at 7T. 7T images were successfully incorporated into preoperative planning and intraoperative neuronavigation. Conclusion Our study represents the first application of 7T MRI to the full neurosurgical workflow for endoscopic endonasal surgery. We detected higher rates of cranial nerves and ICA branches at 7T MRI compared to 3T and 1.5 T, and found that integration of 7T into surgical planning and guidance was feasible. These results suggest a potential for 7T MRI to reduce surgical complications. Future studies comparing standardized 7T, 3T, and 1.5 T MRI protocols in a larger number of patients are warranted to determine the relative benefit of 7T MRI for endonasal endoscopic surgical efficacy. PMID:28359922

Skull fracture

MedlinePlus

Basilar skull fracture; Depressed skull fracture; Linear skull fracture ... Skull fractures may occur with head injuries . The skull provides good protection for the brain. However, a severe impact ...

Severe complication of posterior nasal packing: Case Report.

PubMed

Pinto, José Antônio; Cintra, Pedro Paulo Vivacqua da Cunha; Sônego, Thiago Branco; Leal, Carolina de Farias Aires; Artico, Marina Spadari; Soares, Josemar Dos Santos

2012-10-01

 Severe Epistaxis is common in patients with head trauma, especially when associated with multiple fractures of the face and skull base. Several methods of controlling bleeding that can be imposed. The anterior nasal tapenade associated with posterior Foley catheter is one of the most widespread, and the universal availability of necessary materials or their apparent ease of execution.  Case report on control of severe epistaxis after severe TBI, with posterior nasal packing by Foley catheter and control tomography showing multiple fractures of the skull base and penetration of the probe into the brain parenchyma.  This is a rare but possible complication in the treatment of severe nose bleeds associated with fracture of the skull base. This brief report highlights risks related to the method and suggests some care to prevent complications related through a brief literature review.

The Ardipithecus ramidus skull and its implications for hominid origins.

PubMed

Suwa, Gen; Asfaw, Berhane; Kono, Reiko T; Kubo, Daisuke; Lovejoy, C Owen; White, Tim D

2009-10-02

The highly fragmented and distorted skull of the adult skeleton ARA-VP-6/500 includes most of the dentition and preserves substantial parts of the face, vault, and base. Anatomical comparisons and micro-computed tomography-based analysis of this and other remains reveal pre-Australopithecus hominid craniofacial morphology and structure. The Ardipithecus ramidus skull exhibits a small endocranial capacity (300 to 350 cubic centimeters), small cranial size relative to body size, considerable midfacial projection, and a lack of modern African ape-like extreme lower facial prognathism. Its short posterior cranial base differs from that of both Pan troglodytes and P. paniscus. Ar. ramidus lacks the broad, anteriorly situated zygomaxillary facial skeleton developed in later Australopithecus. This combination of features is apparently shared by Sahelanthropus, showing that the Mio-Pliocene hominid cranium differed substantially from those of both extant apes and Australopithecus.

A retrospective study of skull base neoplasia in 42 dogs.

PubMed

Rissi, Daniel R

2015-11-01

This study describes the prevalence and distribution of 42 cases of skull base neoplasia in dogs between 2000 and 2014. The average age of affected individuals was 9.5 years, and there was no sex or breed predisposition. The most common skull base neoplasms were meningioma (25 cases) and pituitary adenoma (9 cases). Less common tumors included craniopharyngioma (2 cases), nerve sheath tumor (2 cases), and 1 case each of pituitary carcinoma, meningeal oligodendrogliomatosis, presumed nasal or sinonasal carcinoma, and multilobular tumor of bone. All neoplasms caused some degree of compression of adjacent structures. The distribution of the tumors was greatest in the sellar region (n = 18), followed by the paranasal region (n = 12), caudal cranial fossa (n = 10), central cranial fossa (n = 1), and rostral cranial fossa (n = 1). © 2015 The Author(s).

Morphometry and CT measurements of useful bony landmarks of skull base.

PubMed

Ray, Biswabina; Rajagopal, K V; Rajesh, T; Gayathri, B M V; D'Souza, A S; Swarnashri, J V; Saxena, Alok

2011-01-01

Aim of this study was to determine the distance between Henle's spine (HS) on the temporal bone to the clinically important bony landmarks on the dry skulls that will act as a guide in various surgical procedures on skull base. Distances from the head of malleus (HOM) to surgically relevant landmarks were also studied on CT images. Thirty-nine adult preserved dry skulls were studied bilaterally. The parapetrosal triangle bounded by spinopterygoidal, bispinal and the midsagittal lines was identified. The location of the HS and its distance from the various important anatomical structures were measured. In addition, five CT images, where distances from the HOM to various anatomical landmarks were measured. The mean and range of distances from the HS to various important anatomical landmarks on the spinopterygoidal line, bispinal line and in the parapetrosal triangle were tabulated. The mean and range of CT-based measurements of distances from HOM to other anatomical landmarks were also noted. The knowledge of unvarying relationship of the HS and the HOM to the various structures of the skull would assume significance while planning surgeries around the temporal bone by guiding the direction and degree of bone removal. Statistical differences between the two genders showed significant difference only in the distance between the HS to the medial margin of the external orifice of carotid canal. Therefore, these landmarks can also be applied as references for various surgeries of middle cranial fossa, as well as transpetrosal and transmastoid approaches.

Assessment of craniometric traits in South Indian dry skulls for sex determination.

PubMed

Ramamoorthy, Balakrishnan; Pai, Mangala M; Prabhu, Latha V; Muralimanju, B V; Rai, Rajalakshmi

2016-01-01

The skeleton plays an important role in sex determination in forensic anthropology. The skull bone is considered as the second best after the pelvic bone in sex determination due to its better retention of morphological features. Different populations have varying skeletal characteristics, making population specific analysis for sex determination essential. Hence the objective of this investigation is to obtain the accuracy of sex determination using cranial parameters of adult skulls to the highest percentage in South Indian population and to provide a baseline data for sex determination in South India. Seventy adult preserved human skulls were taken and based on the morphological traits were classified into 43 male skulls and 27 female skulls. A total of 26 craniometric parameters were studied. The data were analyzed by using the SPSS discriminant function. The analysis of stepwise, multivariate, and univariate discriminant function gave an accuracy of 77.1%, 85.7%, and 72.9% respectively. Multivariate direct discriminant function analysis classified skull bones into male and female with highest levels of accuracy. Using stepwise discriminant function analysis, the most dimorphic variable to determine sex of the skull, was biauricular breadth followed by weight. Subjecting the best dimorphic variables to univariate discriminant analysis, high levels of accuracy of sexual dimorphism was obtained. Percentage classification of high accuracies were obtained in this study indicating high level of sexual dimorphism in the crania, setting specific discriminant equations for the gender determination in South Indian people. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Morphometric appraisal of the skull of Caroline Crachami, the Sicilian "dwarf" 1815?-1824: a contribution to the study of primordial microcephalic dwarfism.

PubMed

Jeffery, Nathan; Berkovitz, B K B

2002-08-15

The skeleton of Caroline Crachami is a rare historical example of primordial microcephalic dwarfism (PMD). Studies show the condition to be heterogeneous, with at least three types, for which the assessment criteria rely on descriptive evaluations and/or simple measures with regard to cranial features. Advances in noninvasive imaging allow for a more complete morphometric examination of the skull of Caroline Crachami with the aim of clarifying aspects of the condition. In the present study, the skull of Caroline Crachami was three-dimensionally imaged with computed tomography (CT) and reconstructed in virtual space. Coordinates for a number of measurements were taken to represent interesting anatomies with an emphasis on those measures not easily replicated on the skull itself. Volumes of the endocranial cavity and sella turcica were also computed. These data were compared with normative values taken from the literature and measured from CT images of the Bosma collection. Findings indicate that the general size of the skull is equivalent to that of a 6- to 8-month-old, that the endocranial volume and cranial base angle are commensurate with that of a newborn, and that the sella volume is the same as that for an 8- to 15-month-old. Apart from these traits, the skull was well proportioned and within the range of normal variation for a skull aged between 2-9 years. We conclude that further quantitative analysis on related skulls is warranted in the study of PMD using the methods and techniques described. Copyright 2002 Wiley-Liss, Inc.

Biomechanical Evaluation of Different Musculoskeletal Arrangements in Psittacosaurus and Implications for Cranial Function.

PubMed

Taylor, Adam C; Lautenschlager, Stephan; Qi, Zhao; Rayfield, Emily J

2017-01-01

The masseter muscle complex is a unique feature of extant mammals and their advanced cynodont precursors, originating from the zygomatic arch and inserting onto the lateral surface of the dentary. This muscle complex is absent in sauropsids, with the exception of the neomorphic m. pseudomasseter complex that is unique to psittaciform birds (parrots and cockatiels). The anterior position and anterodorsally inclined line of action of both muscle groups increases leverage of the jaw and is thought to contribute to increased bite force, particularly in psittaciforms. A corollary is that in mammals at least, the masseter places increased load on the zygomatic arch, which may be withstood by soft tissue temporal fascia. Recently the existence of a m. pseudomasster (mPSM) and m. adductor mandibulae externus ventralis (mAMEV) has been proposed in the ornithischian dinosaur Psittacosaurus. Here we use computed tomography, digital restoration of skull anatomy and adductor musculature and computational biomechanics to test how the presence of anterodorsally inclined muscle loads influences stress, strain, deformation and estimated bite forces in the skull of Psittacosaurus. We find that the m. pseudomasseter and m. amev increases bite force with an associated increase in cranial stress and deformation. There is, however, limited osteological evidence for the existence of these two additional muscles in the psittacosaur skull and geometric morphometric informed sensitivity analysis of our finite element models shows that bite position has a greater effect on loading-induced deformation than muscle loading or material property variation. Anat Rec, 300:49-61, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Quality assurance of multiport image-guided minimally invasive surgery at the lateral skull base.

PubMed

Nau-Hermes, Maria; Schmitt, Robert; Becker, Meike; El-Hakimi, Wissam; Hansen, Stefan; Klenzner, Thomas; Schipper, Jörg

2014-01-01

For multiport image-guided minimally invasive surgery at the lateral skull base a quality management is necessary to avoid the damage of closely spaced critical neurovascular structures. So far there is no standardized method applicable independently from the surgery. Therefore, we adapt a quality management method, the quality gates (QG), which is well established in, for example, the automotive industry and apply it to multiport image-guided minimally invasive surgery. QG divide a process into different sections. Passing between sections can only be achieved if previously defined requirements are fulfilled which secures the process chain. An interdisciplinary team of otosurgeons, computer scientists, and engineers has worked together to define the quality gates and the corresponding criteria that need to be fulfilled before passing each quality gate. In order to evaluate the defined QG and their criteria, the new surgery method was applied with a first prototype at a human skull cadaver model. We show that the QG method can ensure a safe multiport minimally invasive surgical process at the lateral skull base. Therewith, we present an approach towards the standardization of quality assurance of surgical processes.

Quality Assurance of Multiport Image-Guided Minimally Invasive Surgery at the Lateral Skull Base

PubMed Central

Nau-Hermes, Maria; Schmitt, Robert; Becker, Meike; El-Hakimi, Wissam; Hansen, Stefan; Klenzner, Thomas; Schipper, Jörg

2014-01-01

For multiport image-guided minimally invasive surgery at the lateral skull base a quality management is necessary to avoid the damage of closely spaced critical neurovascular structures. So far there is no standardized method applicable independently from the surgery. Therefore, we adapt a quality management method, the quality gates (QG), which is well established in, for example, the automotive industry and apply it to multiport image-guided minimally invasive surgery. QG divide a process into different sections. Passing between sections can only be achieved if previously defined requirements are fulfilled which secures the process chain. An interdisciplinary team of otosurgeons, computer scientists, and engineers has worked together to define the quality gates and the corresponding criteria that need to be fulfilled before passing each quality gate. In order to evaluate the defined QG and their criteria, the new surgery method was applied with a first prototype at a human skull cadaver model. We show that the QG method can ensure a safe multiport minimally invasive surgical process at the lateral skull base. Therewith, we present an approach towards the standardization of quality assurance of surgical processes. PMID:25105146

Isolated Petroclival Craniopharyngioma with Aggressive Skull Base Destruction

PubMed Central

Lee, Young-Hen; Lim, Dong-Jun; Park, Jung-Yul; Chung, Yong-Gu; Kim, Young-Sik

2009-01-01

We report a rare case of petroclival craniopharyngioma with no connection to the sellar or suprasellar region. MRI and CT images revealed a homogenously enhancing retroclival solid mass with aggressive skull base destruction, mimicking chordoma or aggressive sarcoma. However, there was no calcification or cystic change found in the mass. Here, we report the clinical features and radiographic investigation of this uncommon craniopharyngioma arising primarily in the petroclival region. PMID:19881982

Balloon-assisted embolization of skull base meningioma with liquid embolic agent.

PubMed

Abdel Kerim, Amr; Bonneville, Fabrice; Jean, Betty; Cornu, Philippe; LeJean, Lise; Chiras, Jacques

2010-01-01

The authors report a novel technique of balloon-assisted embolization of a skull base meningioma supplied by a branch of the cavernous segment of the internal carotid artery using liquid embolic agent. A temporarily inflated balloon distal to the meningioma's feeding vessel may improve the access to this small branch and may reduce the chances of unintended reflux during delivery of the liquid embolic agent.

Cranial asymmetry in Eocene archaeocete whales and the evolution of directional hearing in water

PubMed Central

Fahlke, Julia M.; Gingerich, Philip D.; Welsh, Robert C.; Wood, Aaron R.

2011-01-01

Eocene archaeocete whales gave rise to all modern toothed and baleen whales (Odontoceti and Mysticeti) during or near the Eocene-Oligocene transition. Odontocetes have asymmetrical skulls, with asymmetry linked to high-frequency sound production and echolocation. Mysticetes are generally assumed to have symmetrical skulls and lack high-frequency hearing. Here we show that protocetid and basilosaurid archaeocete skulls are distinctly and directionally asymmetrical. Archaeocete asymmetry involves curvature and axial torsion of the cranium, but no telescoping. Cranial asymmetry evolved in Eocene archaeocetes as part of a complex of traits linked to directional hearing (such as pan-bone thinning of the lower jaws, mandibular fat pads, and isolation of the ear region), probably enabling them to hear the higher sonic frequencies of sound-producing fish on which they preyed. Ultrasonic echolocation evolved in Oligocene odontocetes, enabling them to find silent prey. Asymmetry and much of the sonic-frequency range of directional hearing were lost in Oligocene mysticetes during the shift to low-frequency hearing and bulk-straining predation. PMID:21873217

Contemporary skull development - palatal angle analysis.

PubMed

Dostalova, T; Eliasova, H; Gabcova, D; Feberova, J; Kaminek, M

2015-01-01

The palatal angle is an important angle of the craniofacial complex. It is significant for the diagnosis of craniofacial disorders mainly for nasopharyngeal soft-tissue patterns.Background The dentists and otorhinolaryngologists use this relationship to establish proper treatment mechanics and evaluate facial profile. The aims of this study were to provide comparative cephalometric analyses of historical and contemporary skulls. A total of 190 cephalograms of 2 groups of subjects were evaluated. Dolphin Imaging 11.0 - Cephalometric Tracing Analysis was used for the analysis. Unpaired two-tailed t-test assuming equality of variances was used for all variables (at the significance level p = 0.0001). The -modern forensic skulls had larger palatal angle at average value of 8.60 degrees ± 4.35, than that of archeological ones, the average value of which was 6.50 degrees ± 3.92. The difference was found significant. Unpaired two-tailed t-test assuming equality of variances showed that historical and contemporary skulls had statistically significant results. The difference was -2.09 with standard error of 0.60 (95% confidence interval from -3.29 to -0.89). Two-tailed probability attained value of P was less than 0.0001. The difference between both groups was found significant. An increase in the palatal angle can be directly connected with anterior rotation of upper jaw(Tab. 2, Fig. 5, Ref. 19).

Local phylogenetic divergence and global evolutionary convergence of skull function in reef fishes of the family Labridae

PubMed Central

Westneat, Mark W; Alfaro, Michael E; Wainwright, Peter C; Bellwood, David R; Grubich, Justin R; Fessler, Jennifer L; Clements, Kendall D; Smith, Lydia L

2005-01-01

The Labridae is one of the most structurally and functionally diversified fish families on coral and rocky reefs around the world, providing a compelling system for examination of evolutionary patterns of functional change. Labrid fishes have evolved a diverse array of skull forms for feeding on prey ranging from molluscs, crustaceans, plankton, detritus, algae, coral and other fishes. The species richness and diversity of feeding ecology in the Labridae make this group a marine analogue to the cichlid fishes. Despite the importance of labrids to coastal reef ecology, we lack evolutionary analysis of feeding biomechanics among labrids. Here, we combine a molecular phylogeny of the Labridae with the biomechanics of skull function to reveal a broad pattern of repeated convergence in labrid feeding systems. Mechanically fast jaw systems have evolved independently at least 14 times from ancestors with forceful jaws. A repeated phylogenetic pattern of functional divergence in local regions of the labrid tree produces an emergent family-wide pattern of global convergence in jaw function. Divergence of close relatives, convergence among higher clades and several unusual ‘breakthroughs’ in skull function characterize the evolution of functional complexity in one of the most diverse groups of reef fishes. PMID:16024356

Incidental Findings on Cone Beam Computed Tomography Studies outside of the Maxillofacial Skeleton

PubMed Central

2016-01-01

Objective. To define the presence and prevalence of incidental findings in and around the base of skull from large field-of-view CBCT of the maxillofacial region and to determine their clinical importance. Methods. Four hundred consecutive large fields of view CBCT scans viewed from January 1, 2007, to January 1, 2014, were retrospectively evaluated for incidental findings of the cervical vertebrae and surrounding structures. Findings were categorized into cervical vertebrae, intracranial, soft tissue, airway, carotid artery, lymph node, and skull base findings. Results. A total of 653 incidental findings were identified in 309 of the 400 CBCT scans. The most prevalent incidental findings were soft tissue calcifications (29.71%), followed by intracranial calcifications (27.11%), cervical vertebrae (20.06%), airway (11.49%), external carotid artery calcification (10.41%), lymph node calcification (0.77%), subcutaneous tissue calcification and calcified tendonitis of the longus colli muscle (0.3%), and skull base finding (0.15%). A significant portion of the incidental findings (31.24%) required referral, 17.76% required monitoring, and 51% did not require either. Conclusion. A comprehensive review of the CBCT images beyond the region of interest, especially incidental findings in the base of skull, cervical vertebrae, pharyngeal airway, and soft tissue, is necessary to avoid overlooking clinically significant lesions. PMID:27462350

Skull Base Meningiomas and Cranial Nerves Contrast Using Sodium Fluorescein: A New Application of an Old Tool

PubMed Central

da Silva, Carlos Eduardo; da Silva, Vinicius Duval; da Silva, Jefferson Luis Braga

2014-01-01

Objective The identification of cranial nerves is one of the most challenging goals in the dissection of skull base meningiomas. The authors present an application of sodium fluorescein (SF) in skull base meningiomas with the purpose of improving the identification of cranial nerves. Design A prospective study within-subjects design. Setting Hospital Ernesto Dornelles, Porto Alegre, Brazil. Participants Patients with skull base meningiomas. Main Outcomes Measures Cranial nerve identification. Results The group of nine meningiomas was composed of one cavernous sinus, three petroclival, one tuberculum sellae, two sphenoid wing, one olfactory groove, and one temporal floor meningioma. The SF enhancement in all tumors was strong, and the contrast with cranial nerves clearly evident. There were one definite olfactory nerve deficit, one transient abducens deficit, and one definite hemiparesis. All lesions were resected (Simpson grades 1 and 2). The analysis of the difference of the delta SF wavelength between the meningiomas and cranial nerve contrast was performed by the Wilcoxon signed rank test and showed p = 0.011. Conclusions The contrast between the enhanced meningiomas and cranial nerves was evident and assisted in the visualization and microsurgical dissection of these structures. The anatomical preservation of these structures was improved using the contrast. PMID:27054056

Skull Base Meningiomas and Cranial Nerves Contrast Using Sodium Fluorescein: A New Application of an Old Tool.

PubMed

da Silva, Carlos Eduardo; da Silva, Vinicius Duval; da Silva, Jefferson Luis Braga

2014-08-01

Objective The identification of cranial nerves is one of the most challenging goals in the dissection of skull base meningiomas. The authors present an application of sodium fluorescein (SF) in skull base meningiomas with the purpose of improving the identification of cranial nerves. Design A prospective study within-subjects design. Setting Hospital Ernesto Dornelles, Porto Alegre, Brazil. Participants Patients with skull base meningiomas. Main Outcomes Measures Cranial nerve identification. Results The group of nine meningiomas was composed of one cavernous sinus, three petroclival, one tuberculum sellae, two sphenoid wing, one olfactory groove, and one temporal floor meningioma. The SF enhancement in all tumors was strong, and the contrast with cranial nerves clearly evident. There were one definite olfactory nerve deficit, one transient abducens deficit, and one definite hemiparesis. All lesions were resected (Simpson grades 1 and 2). The analysis of the difference of the delta SF wavelength between the meningiomas and cranial nerve contrast was performed by the Wilcoxon signed rank test and showed p = 0.011. Conclusions The contrast between the enhanced meningiomas and cranial nerves was evident and assisted in the visualization and microsurgical dissection of these structures. The anatomical preservation of these structures was improved using the contrast.

Imaging and Outcomes for a New Entity: Low-Grade Sinonasal Sarcoma with Neural and Myogenic Features.

PubMed

Cannon, Richard B; Wiggins, Richard H; Witt, Benjamin L; Dundar, Yusuf; Johnston, Tawni M; Hunt, Jason P

2017-01-01

Objectives  Low-grade sinonasal sarcoma with neural and myogenic features (LGSSNMF) is a new, rare tumor. Our goal is to describe the imaging characteristics and surgical outcomes of this unique skull base malignancy. Design  Retrospective case series. Setting  Academic medical center. Participants  There were three patients who met inclusion criteria with a confirmed LGSSNMF. Main Outcome Measures  Imaging and histopathological characteristics, treatments, survival and recurrence outcomes, complications, morbidity, and mortality. Results  Patients presented with diplopia, facial discomfort, a supraorbital mass, and nasal obstruction. Magnetic resonance imaging and computed tomography imaging in all cases showed an enhancing sinonasal mass with associated hyperostotic bone formation that involved the frontal sinus, invaded the lamina papyracea and anterior skull base, and had intracranial extension. One patient underwent a purely endoscopic surgical resection and the second underwent a craniofacial resection, while the last is pending treatment. All patients recovered well, without morbidity or long-term complications, and are currently without evidence of disease (mean follow-up of 2.1 years). One patient recurred after 17 months and underwent a repeat endoscopic skull base and dural resection. Conclusions  The surgical outcomes and imaging of this unique, locally aggressive skull base tumor are characterized.

The Pedicled Buccal Fat Pad: Anatomical Study of the New Flap for Skull Base Defect Reconstruction After Endoscopic Endonasal Transpterygoid Surgery

PubMed Central

Golbin, Denis A.; Lasunin, Nikolay V.; Cherekaev, Vasily A.; Polev, Georgiy A.

2016-01-01

Objectives To evaluate the efficacy and safety of using a buccal fat pad for endoscopic skull base defect reconstruction. Design Descriptive anatomical study with an illustrative case presentation. Setting Anatomical study was performed on 12 fresh human cadaver specimens with injected arteries (24 sides). Internal carotid artery was exposed in the coronal plane via the endoscopic transpterygoid approach. The pedicled buccal fat pad was used for reconstruction. Participants: 12 human cadaver head specimens; one patient operated using the proposed technique. Main outcome measures: Proximity of the buccal fat pad flap to the defect, compliance of the flap, comfort and safety of harvesting procedure, and compatibility with the Hadad–Bassagasteguy nasoseptal flap. Results: Harvesting procedure was performed using anterior transmaxillary corridor. The pedicled buccal fat pad flap can be used to pack the sphenoid sinus or cover the internal carotid artery from cavernous to upper parapharyngeal segment. Conclusion The buccal fat pad can be safely harvested through the same approach without external incisions and is compliant enough to conform to the skull base defect. The proposed pedicled flap can replace free abdominal fat in central skull base reconstruction. The volume of the buccal fat pad allows obliteration of the sphenoid sinus or upper parapharyngeal space. PMID:28180047

An Innovate Robotic Endoscope Guidance System for Transnasal Sinus and Skull Base Surgery: Proof of Concept.

PubMed

Friedrich, D T; Sommer, F; Scheithauer, M O; Greve, J; Hoffmann, T K; Schuler, P J

2017-12-01

Objective  Advanced transnasal sinus and skull base surgery remains a challenging discipline for head and neck surgeons. Restricted access and space for instrumentation can impede advanced interventions. Thus, we present the combination of an innovative robotic endoscope guidance system and a specific endoscope with adjustable viewing angle to facilitate transnasal surgery in a human cadaver model. Materials and Methods  The applicability of the robotic endoscope guidance system with custom foot pedal controller was tested for advanced transnasal surgery on a fresh frozen human cadaver head. Visualization was enabled using a commercially available endoscope with adjustable viewing angle (15-90 degrees). Results  Visualization and instrumentation of all paranasal sinuses, including the anterior and middle skull base, were feasible with the presented setup. Controlling the robotic endoscope guidance system was effectively precise, and the adjustable endoscope lens extended the view in the surgical field without the common change of fixed viewing angle endoscopes. Conclusion  The combination of a robotic endoscope guidance system and an advanced endoscope with adjustable viewing angle enables bimanual surgery in transnasal interventions of the paranasal sinuses and the anterior skull base in a human cadaver model. The adjustable lens allows for the abandonment of fixed-angle endoscopes, saving time and resources, without reducing the quality of imaging.

Lateral skull base approaches in the management of benign parapharyngeal space tumors.

PubMed

Prasad, Sampath Chandra; Piccirillo, Enrico; Chovanec, Martin; La Melia, Claudio; De Donato, Giuseppe; Sanna, Mario

2015-06-01

To evaluate the role of lateral skull base approaches in the management of benign parapharyngeal space tumors and to propose an algorithm for their surgical approach. Retrospective study of patients with benign parapharyngeal space tumors. The clinical features, radiology and preoperative management of skull base neurovasculature, the surgical approaches and overall results were recorded. 46 patients presented with 48 tumors. 12 were prestyloid and 36 poststyloid. 19 (39.6%) tumors were paragangliomas, 15 (31.25%) were schwannomas and 11 (23%) were pleomorphic adenomas. Preoperative embolization was performed in 19, stenting of the internal carotid artery in 4 and permanent balloon occlusion in 2 patients. 19 tumors were approached by the transcervical, 13 by transcervical-transparotid, 5 by transcervical-transmastoid, 6, 1 and 2 tumors by the infratemporal fossa approach types A, B and D, respectively. Total radical tumor removal was achieved in 46 (96%) of the cases. Lateral skull base approaches have an advantage over other approaches in the management of benign tumors of the parapharyngeal space due to the fact that they provide excellent exposure with less morbidity. The use of microscope combined with bipolar cautery reduces morbidity. Stenting of internal carotid artery gives a chance for complete tumor removal with arterial preservation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Predicting Patient-specific Dosimetric Benefits of Proton Therapy for Skull-base Tumors Using a Geometric Knowledge-based Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, David C.; Trofimov, Alexei V.; Winey, Brian A.

Purpose: To predict the organ at risk (OAR) dose levels achievable with proton beam therapy (PBT), solely based on the geometric arrangement of the target volume in relation to the OARs. A comparison with an alternative therapy yields a prediction of the patient-specific benefits offered by PBT. This could enable physicians at hospitals without proton capabilities to make a better-informed referral decision or aid patient selection in model-based clinical trials. Methods and Materials: Skull-base tumors were chosen to test the method, owing to their geometric complexity and multitude of nearby OARs. By exploiting the correlations between the dose and distance-to-targetmore » in existing PBT plans, the models were independently trained for 6 types of OARs: brainstem, cochlea, optic chiasm, optic nerve, parotid gland, and spinal cord. Once trained, the models could estimate the feasible dose–volume histogram and generalized equivalent uniform dose (gEUD) for OAR structures of new patients. The models were trained using 20 patients and validated using an additional 21 patients. Validation was achieved by comparing the predicted gEUD to that of the actual PBT plan. Results: The predicted and planned gEUD were in good agreement. Considering all OARs, the prediction error was +1.4 ± 5.1 Gy (mean ± standard deviation), and Pearson's correlation coefficient was 93%. By comparing with an intensity modulated photon treatment plan, the model could classify whether an OAR structure would experience a gain, with a sensitivity of 93% (95% confidence interval: 87%-97%) and specificity of 63% (95% confidence interval: 38%-84%). Conclusions: We trained and validated models that could quickly and accurately predict the patient-specific benefits of PBT for skull-base tumors. Similar models could be developed for other tumor sites. Such models will be useful when an estimation of the feasible benefits of PBT is desired but the experience and/or resources required for treatment planning are unavailable.« less

Full-wave acoustic and thermal modeling of transcranial ultrasound propagation and investigation of skull-induced aberration correction techniques: a feasibility study.

PubMed

Kyriakou, Adamos; Neufeld, Esra; Werner, Beat; Székely, Gábor; Kuster, Niels

2015-01-01

Transcranial focused ultrasound (tcFUS) is an attractive noninvasive modality for neurosurgical interventions. The presence of the skull, however, compromises the efficiency of tcFUS therapy, as its heterogeneous nature and acoustic characteristics induce significant distortion of the acoustic energy deposition, focal shifts, and thermal gain decrease. Phased-array transducers allow for partial compensation of skull-induced aberrations by application of precalculated phase and amplitude corrections. An integrated numerical framework allowing for 3D full-wave, nonlinear acoustic and thermal simulations has been developed and applied to tcFUS. Simulations were performed to investigate the impact of skull aberrations, the possibility of extending the treatment envelope, and adverse secondary effects. The simulated setup comprised an idealized model of the ExAblate Neuro and a detailed MR-based anatomical head model. Four different approaches were employed to calculate aberration corrections (analytical calculation of the aberration corrections disregarding tissue heterogeneities; a semi-analytical ray-tracing approach compensating for the presence of the skull; two simulation-based time-reversal approaches with and without pressure amplitude corrections which account for the entire anatomy). These impact of these approaches on the pressure and temperature distributions were evaluated for 22 brain-targets. While (semi-)analytical approaches failed to induced high pressure or ablative temperatures in any but the targets in the close vicinity of the geometric focus, simulation-based approaches indicate the possibility of considerably extending the treatment envelope (including targets below the transducer level and locations several centimeters off the geometric focus), generation of sharper foci, and increased targeting accuracy. While the prediction of achievable aberration correction appears to be unaffected by the detailed bone-structure, proper consideration of inhomogeneity is required to predict the pressure distribution for given steering parameters. Simulation-based approaches to calculate aberration corrections may aid in the extension of the tcFUS treatment envelope as well as predict and avoid secondary effects (standing waves, skull heating). Due to their superior performance, simulationbased techniques may prove invaluable in the amelioration of skull-induced aberration effects in tcFUS therapy. The next steps are to investigate shear-wave-induced effects in order to reliably exclude secondary hot-spots, and to develop comprehensive uncertainty assessment and validation procedures.

Craniofacial morphology in ancient and modern Greeks through 4,000 years.

PubMed

Papagrigorakis, Manolis J; Kousoulis, Antonis A; Synodinos, Philippos N

2014-01-01

Multiple 20th century studies have speculated on the anthropological similarities of the modern inhabitants of Greece with their ancient predecessors. The present investigation attempts to add to this knowledge by comparing the craniofacial configuration of 141 ancient (dating around 2,000-500 BC) and 240 modern Greek skulls (the largest material among relevant national studies). Skulls were grouped in age at death, sex, era and geographical categories; lateral cephalograms were taken and 53 variables were measured and correlated statistically. The craniofacial measurements and measurements of the basic quadrilateral and cranial polygon were compared in various groups using basic statistical methods, one-way ANOVA and assessment of the correlation matrices. Most of the measurements for both sexes combined followed an akin pattern in ancient and modern Greek skulls. Moreover, sketching and comparing the outline of the skull and upper face, we observed a clock-wise movement. The present study confirms that the morphological pattern of Greek skulls, as it changed during thousands of years, kept some characteristics unchanged, with others undergoing logical modifications. The analysis of our results allows us to believe that the influence upon the craniofacial complex of the various known factors, including genetic or environmental alterations, is apt to alter its form to adapt to new conditions. Even though 4,000 years seems too narrow a span to provoke evolutionary insights using conventional geometric morphometrics, the full presentation of our results makes up a useful atlas of solid data. Interpreted with caution, the craniofacial morphology in modern and ancient Greeks indicates elements of ethnic group continuation within the unavoidable multicultural mixtures.

Evolution of skull shape in the family Salamandridae (Amphibia: Caudata).

PubMed

Ivanović, Ana; Arntzen, Jan W

2018-03-01

We carried out a comparative morphometric analysis of 56 species of salamandrid salamanders, representing 19 out of 21 extant genera, with the aim of uncovering the major patterns of skull shape diversification, and revealing possible trends and directions of evolutionary change. To do this we used micro-computed tomography scanning and three-dimensional geometric morphometrics, along with a well-resolved molecular phylogeny. We found that allometry explains a relatively small amount of shape variation across taxa. Congeneric species of salamandrid salamanders are more similar to each other and cluster together producing distinct groups in morphospace. We detected a strong phylogenetic signal and little homoplasy. The most pronounced changes in the skull shape are related to the changes of the frontosquamosal arch, a unique feature of the cranial skeleton for the family Salamandridae, which is formed by processes arising from the frontal and squamosal bones that arch over the orbits. By mapping character states over the phylogeny, we found that a reduction of the frontosquamosal arch occurs independently in three lineages of the subfamily Pleurodelinae. This reduction can probably be attributed to changes in the development and ossification rates of the frontosquamosal arch. In general, our results are similar to those obtained for caecilian amphibians, with an early expansion into the available morphospace and a complex history characterizing evolution of skull shape in both groups. To evaluate the specificity of the inferred evolutionary trajectories and Caudata-wide trends in the diversity of skull morphology, information from additional groups of tailed amphibians is needed. © 2017 Anatomical Society.

Determinants of the electric field during transcranial direct current stimulation.

PubMed

Opitz, Alexander; Paulus, Walter; Will, Susanne; Antunes, Andre; Thielscher, Axel

2015-04-01

Transcranial direct current stimulation (tDCS) causes a complex spatial distribution of the electric current flow in the head which hampers the accurate localization of the stimulated brain areas. In this study we show how various anatomical features systematically shape the electric field distribution in the brain during tDCS. We constructed anatomically realistic finite element (FEM) models of two individual heads including conductivity anisotropy and different skull layers. We simulated a widely employed electrode montage to induce motor cortex plasticity and moved the stimulating electrode over the motor cortex in small steps to examine the resulting changes of the electric field distribution in the underlying cortex. We examined the effect of skull thickness and composition on the passing currents showing that thinner skull regions lead to higher electric field strengths. This effect is counteracted by a larger proportion of higher conducting spongy bone in thicker regions leading to a more homogenous current over the skull. Using a multiple regression model we could identify key factors that determine the field distribution to a significant extent, namely the thicknesses of the cerebrospinal fluid and the skull, the gyral depth and the distance to the anode and cathode. These factors account for up to 50% of the spatial variation of the electric field strength. Further, we demonstrate that individual anatomical factors can lead to stimulation "hotspots" which are partly resistant to electrode positioning. Our results give valuable novel insights in the biophysical foundation of tDCS and highlight the importance to account for individual anatomical factors when choosing an electrode montage. Copyright © 2015 Elsevier Inc. All rights reserved.

Degradation of the Bragg peak due to inhomogeneities.

PubMed

Urie, M; Goitein, M; Holley, W R; Chen, G T

1986-01-01

The rapid fall-off of dose at the end of range of heavy charged particle beams has the potential in therapeutic applications of sparing critical structures just distal to the target volume. Here we explored the effects of highly inhomogeneous regions on this desirable depth-dose characteristic. The proton depth-dose distribution behind a lucite-air interface parallel to the beam was bimodal, indicating the presence of two groups of protons with different residual ranges, creating a step-like depth-dose distribution at the end of range. The residual ranges became more spread out as the interface was angled at 3 degrees, and still more at 6 degrees, to the direction of the beam. A second experiment showed little significant effect on the distal depth-dose of protons having passed through a mosaic of teflon and lucite. Anatomic studies demonstrated significant effects of complex fine inhomogeneities on the end of range characteristics. Monoenergetic protons passing through the petrous ridges and mastoid air cells in the base of skull showed a dramatic degradation of the distal Bragg peak. In beams with spread out Bragg peaks passing through regions of the base of skull, the distal fall-off from 90 to 20% dose was increased from its nominal 6 to well over 32 mm. Heavy ions showed a corresponding degradation in their ends of range. In the worst case in the base of skull region, a monoenergetic neon beam showed a broadening of the full width at half maximum of the Bragg peak to over 15 mm (compared with 4 mm in a homogeneous unit density medium). A similar effect was found with carbon ions in the abdomen, where the full width at half maximum of the Bragg peak (nominally 5.5 mm) was found to be greater than 25 mm behind gas-soft-tissue interfaces. We address the implications of these data for dose computation with heavy charged particles.

Preliminary study on magnetic tracking-based planar shape sensing and navigation for flexible surgical robots in transoral surgery: methods and phantom experiments.

PubMed

Song, Shuang; Zhang, Changchun; Liu, Li; Meng, Max Q-H

2018-02-01

Flexible surgical robot can work in confined and complex environments, which makes it a good option for minimally invasive surgery. In order to utilize flexible manipulators in complicated and constrained surgical environments, it is of great significance to monitor the position and shape of the curvilinear manipulator in real time during the procedures. In this paper, we propose a magnetic tracking-based planar shape sensing and navigation system for flexible surgical robots in the transoral surgery. The system can provide the real-time tip position and shape information of the robot during the operation. We use wire-driven flexible robot to serve as the manipulator. It has three degrees of freedom. A permanent magnet is mounted at the distal end of the robot. Its magnetic field can be sensed with a magnetic sensor array. Therefore, position and orientation of the tip can be estimated utilizing a tracking method. A shape sensing algorithm is then carried out to estimate the real-time shape based on the tip pose. With the tip pose and shape display in the 3D reconstructed CT model, navigation can be achieved. Using the proposed system, we carried out planar navigation experiments on a skull phantom to touch three different target positions under the navigation of the skull display interface. During the experiments, the real-time shape has been well monitored and distance errors between the robot tip and the targets in the skull have been recorded. The mean navigation error is [Formula: see text] mm, while the maximum error is 3.2 mm. The proposed method provides the advantages that no sensors are needed to mount on the robot and no line-of-sight problem. Experimental results verified the feasibility of the proposed method.

Extensive traumatic anterior skull base fractures with cerebrospinal fluid leak: classification and repair techniques using combined vascularized tissue flaps.

PubMed

Archer, Jacob B; Sun, Hai; Bonney, Phillip A; Zhao, Yan Daniel; Hiebert, Jared C; Sanclement, Jose A; Little, Andrew S; Sughrue, Michael E; Theodore, Nicholas; James, Jeffrey; Safavi-Abbasi, Sam

2016-03-01

This article introduces a classification scheme for extensive traumatic anterior skull base fracture to help stratify surgical treatment options. The authors describe their multilayer repair technique for cerebrospinal fluid (CSF) leak resulting from extensive anterior skull base fracture using a combination of laterally pediculated temporalis fascial-pericranial, nasoseptal-pericranial, and anterior pericranial flaps. Retrospective chart review identified patients treated surgically between January 2004 and May 2014 for anterior skull base fractures with CSF fistulas. All patients were treated with bifrontal craniotomy and received pedicled tissue flaps. Cases were classified according to the extent of fracture: Class I (frontal bone/sinus involvement only); Class II (extent of involvement to ethmoid cribriform plate); and Class III (extent of involvement to sphenoid bone/sinus). Surgical repair techniques were tailored to the types of fractures. Patients were assessed for CSF leak at follow-up. The Fisher exact test was applied to investigate whether the repair techniques were associated with persistent postoperative CSF leak. Forty-three patients were identified in this series. Thirty-seven (86%) were male. The patients' mean age was 33 years (range 11-79 years). The mean overall length of follow-up was 14 months (range 5-45 months). Six fractures were classified as Class I, 8 as Class II, and 29 as Class III. The anterior pericranial flap alone was used in 33 patients (77%). Multiple flaps were used in 10 patients (3 salvage) (28%)--1 with Class II and 9 with Class III fractures. Five (17%) of the 30 patients with Class II or III fractures who received only a single anterior pericranial flap had persistent CSF leak (p < 0.31). No CSF leak was found in patients who received multiple flaps. Although postoperative CSF leak occurred only in high-grade fractures with single anterior flap repair, this finding was not significant. Extensive anterior skull base fractures often require aggressive treatment to provide the greatest long-term functional and cosmetic benefits. Several vascularized tissue flaps can be used, either alone or in combination. Vascularized flaps are an ideal substrate for cranial base repair. Dual and triple flap techniques that combine the use of various anterior, lateral, and nasoseptal flaps allow for a comprehensive arsenal in multilayered skull base repair and salvage therapy for extensive and severe fractures.

Severe complication of posterior nasal packing: Case Report

PubMed Central

Pinto, José Antônio; Cintra, Pedro Paulo Vivacqua da Cunha; Sônego, Thiago Branco; Leal, Carolina de Farias Aires; Artico, Marina Spadari; Soares, Josemar dos Santos

2012-01-01

Summary Introduction: Severe Epistaxis is common in patients with head trauma, especially when associated with multiple fractures of the face and skull base. Several methods of controlling bleeding that can be imposed. The anterior nasal tapenade associated with posterior Foley catheter is one of the most widespread, and the universal availability of necessary materials or their apparent ease of execution. Methods: Case report on control of severe epistaxis after severe TBI, with posterior nasal packing by Foley catheter and control tomography showing multiple fractures of the skull base and penetration of the probe into the brain parenchyma. Conclusion: This is a rare but possible complication in the treatment of severe nose bleeds associated with fracture of the skull base. This brief report highlights risks related to the method and suggests some care to prevent complications related through a brief literature review. PMID:25991984

Do Concomitant Cranium and Axis Injuries Predict Worse Outcome? A Trauma Database Quantitative Analysis

PubMed Central

Chittiboina, Prashant; Banerjee, Anirban Deep; Nanda, Anil

2011-01-01

We performed a trauma database analysis to identify the effect of concomitant cranial injuries on outcome in patients with fractures of the axis. We identified patients with axis fractures over a 14-year period. A binary outcome measure was used. Univariate and multiple logistic regression analysis were performed. There were 259 cases with axis fractures. Closed head injury was noted in 57% and skull base trauma in 14%. Death occurred in 17 cases (6%). Seventy-two percent had good outcome. Presence of abnormal computed tomography head findings, skull base fractures, and visceral injury was significantly associated with poor outcome. Skull base injury in association with fractures of the axis is a significant independent predictor of worse outcomes, irrespective of the severity of the head injury. We propose that presence of concomitant cranial and upper vertebral injuries require careful evaluation in view of the associated poor prognosis. PMID:22470268

Hepatocellular carcinoma metastasizing to the skull base involving multiple cranial nerves.

PubMed

Kim, Soo Ryang; Kanda, Fumio; Kobessho, Hiroshi; Sugimoto, Koji; Matsuoka, Toshiyuki; Kudo, Masatoshi; Hayashi, Yoshitake

2006-11-07

We describe a rare case of HCV-related recurrent multiple hepatocellular carcinoma (HCC) metastasizing to the skull base involving multiple cranial nerves in a 50-year-old woman. The patient presented with symptoms of ptosis, fixation of the right eyeball, and left abducens palsy, indicating disturbances of the right oculomotor and trochlear nerves and bilateral abducens nerves. Brain contrast-enhanced computed tomography (CT) revealed an ill-defined mass with abnormal enhancement around the sella turcica. Brain magnetic resonance imaging (MRI) disclosed that the mass involved the clivus, cavernous sinus, and petrous apex. On contrast-enhanced MRI with gadolinium-chelated contrast medium, the mass showed inhomogeneous intermediate enhancement. The diagnosis of metastatic HCC to the skull base was made on the basis of neurological findings and imaging studies including CT and MRI, without histological examinations. Further studies may provide insights into various methods for diagnosing HCC metastasizing to the craniospinal area.

Calvarial and skull base metastases: expanding the clinical utility of Gamma Knife surgery.

PubMed

Kotecha, Rupesh; Angelov, Lilyana; Barnett, Gene H; Reddy, Chandana A; Suh, John H; Murphy, Erin S; Neyman, Gennady; Chao, Samuel T

2014-12-01

Traditionally, the treatment of choice for patients with metastases to the calvaria or skull base has been conventional radiation therapy. Because patients with systemic malignancies are also at risk for intracranial metastases, the utility of Gamma Knife surgery (GKS) for these patients has been explored to reduce excess radiation exposure to the perilesional brain parenchyma. The purpose of this study was to report the efficacy of GKS for the treatment of calvarial metastases and skull base lesions. The authors performed a retrospective chart review of 21 patients with at least 1 calvarial or skull base metastatic lesion treated with GKS during 2001-2013. For 7 calvarial lesions, a novel technique, in which a bolus was placed over the treatment site, was used. For determination of local control or disease progression, radiation therapy data were examined and posttreatment MR images and oncology records were reviewed. Survival times from the date of procedure were estimated by using Kaplan-Meier analyses. The median patient age at treatment was 57 years (range 29-84 years). A total of 19 (90%) patients received treatment for single lesions, 1 patient received treatment for 3 lesions, and 1 patient received treatment for 4 lesions. The most common primary tumor was breast cancer (24% of patients). Per lesion, the median clinical and radiographic follow-up times were 10.3 months (range 0-71.9 months) and 7.1 months (range 0-61.3 months), respectively. Of the 26 lesions analyzed, 14 (54%) were located in calvarial bones and 12 (46%) were located in the skull base. The median lesion volume was 5.3 cm(3) (range 0.3-55.6 cm(3)), and the median prescription margin dose was 15 Gy (range 13-24 Gy). The median overall survival time for all patients was 35.9 months, and the 1-year local control rate was 88.9% (95% CI 74.4%-100%). Local control rates did not differ between lesions treated with the bolus technique and those treated with traditional methods or between calvarial lesions and skull base lesions (p > 0.05). Of the 3 patients for whom local treatment failed, 1 patient received no further treatment and 2 patients responded to salvage chemotherapy. Subsequent brain parenchymal metastases developed in 2 patients, who then underwent GKS. GKS is an effective treatment modality for patients with metastases to the calvarial bones or skull base. For patients with superficial calvarial lesions, a novel approach with bolus application resulted in excellent rates of local control. GKS provides an effective therapeutic alternative to conventional radiation therapy and should be considered for patients at risk for calvarial metastases and brain parenchymal metastases.

Method for noninvasive intracranial pressure measurement

DOEpatents

Sinha, Dipen N.

2000-01-01

An ultrasonic-based method for continuous, noninvasive intracranial pressure (ICP) measurement and monitoring is described. The stress level in the skull bone is affected by pressure. This also changes the interfacial conditions between the dura matter and the skull bone. Standing waves may be set up in the skull bone and the layers in contact with the bone. At specific frequencies, there are resonance peaks in the response of the skull which can be readily detected by sweeping the excitation frequency on an excitation transducer in contact with a subject's head, while monitoring the standing wave characteristics from the signal received on a second, receiving transducer similarly in contact with the subject's head. At a chosen frequency, the phase difference between the excitation signal and the received signal can be determined. This difference can be related to the intracranial pressure and changes therein.

A metric analysis of Mumbai region (India) crania.

PubMed

Salve, Vishal M; Chandrashekhar, C H

2012-10-01

The human skull has been studied both metrically and non- metrically previously. These studies have thrown light on the functional and morphological aspect of the skull. Cranial index and other cranial indices are useful in differentiation of racial and gender difference. As studies on sexual dimorphism of cranium were very few we have taken this study to find out the differences in cranial index, vertical index and transverse vertical index of male and female crania at Mumbai region. This study was carried out on 210 (150 males and 60 females) dry human skulls available in department of anatomy of four Medical Colleges in Mumbai. The mean and SD of cranial index were 74.23 +/- 4.06; for males: 73.19 +/- 3.76, and for females: 76.84 +/- 3.63. The mean and SD of transverse vertical index were 100.84 +/- 6.31; for males: 102.19 +/- 6.15, and for females: 97.46 +/- 5.41. The difference between cranial index (p = 0.000000) and transverse vertical index (p = 0.000019) of male and female skulls were significant. The results of the present study show that majority of male skulls of Mumbai region belong to dolicocephalic group and majority of female skulls to mesocephalic.The result of present study shows that majority of male skulls of Mumbai region belong to acrocranial group (based on transverse vertical index). This data can be useful for forensic medicine experts, plastic surgeons, anatomist and oral surgeons for clinical and research purpose.

Estimation of skull table thickness with clinical CT and validation with microCT.

PubMed

Lillie, Elizabeth M; Urban, Jillian E; Weaver, Ashley A; Powers, Alexander K; Stitzel, Joel D

2015-01-01

Brain injuries resulting from motor vehicle crashes (MVC) are extremely common yet the details of the mechanism of injury remain to be well characterized. Skull deformation is believed to be a contributing factor to some types of traumatic brain injury (TBI). Understanding biomechanical contributors to skull deformation would provide further insight into the mechanism of head injury resulting from blunt trauma. In particular, skull thickness is thought be a very important factor governing deformation of the skull and its propensity for fracture. Current computed tomography (CT) technology is limited in its ability to accurately measure cortical thickness using standard techniques. A method to evaluate cortical thickness using cortical density measured from CT data has been developed previously. This effort validates this technique for measurement of skull table thickness in clinical head CT scans using two postmortem human specimens. Bone samples were harvested from the skulls of two cadavers and scanned with microCT to evaluate the accuracy of the estimated cortical thickness measured from clinical CT. Clinical scans were collected at 0.488 and 0.625 mm in plane resolution with 0.625 mm thickness. The overall cortical thickness error was determined to be 0.078 ± 0.58 mm for cortical samples thinner than 4 mm. It was determined that 91.3% of these differences fell within the scanner resolution. Color maps of clinical CT thickness estimations are comparable to color maps of microCT thickness measurements, indicating good quantitative agreement. These data confirm that the cortical density algorithm successfully estimates skull table thickness from clinical CT scans. The application of this technique to clinical CT scans enables evaluation of cortical thickness in population-based studies. © 2014 Anatomical Society.

Skull shape and size variation within and between mendocinus and torquatus groups in the genus Ctenomys (Rodentia: Ctenomyidae) in chromosomal polymorphism context

PubMed Central

Fornel, Rodrigo; Cordeiro-Estrela, Pedro; de Freitas, Thales Renato O.

2018-01-01

Abstract We tested the association between chromosomal polymorphism and skull shape and size variation in two groups of the subterranean rodent Ctenomys. The hypothesis is based on the premise that chromosomal rearrangements in small populations, as it occurs in Ctenomys, produce reproductive isolation and allow the independent diversification of populations. The mendocinus group has species with low chromosomal diploid number variation (2n=46-48), while species from the torquatus group have a higher karyotype variation (2n=42-70). We analyzed the shape and size variation of skull and mandible by a geometric morphometric approach, with univariate and multivariate statistical analysis in 12 species from mendocinus and torquatus groups of the genus Ctenomys. We used 763 adult skulls in dorsal, ventral, and lateral views, and 515 mandibles in lateral view and 93 landmarks in four views. Although we expected more phenotypic variation in the torquatus than the mendocinus group, our results rejected the hypothesis of an association between chromosomal polymorphism and skull shape and size variation. Moreover, the torquatus group did not show more variation than mendocinus. Habitat heterogeneity associated to biomechanical constraints and other factors like geography, phylogeny, and demography, may affect skull morphological evolution in Ctenomys. PMID:29668015

The Skeletal Site-Specific Role of Connective Tissue Growth Factor in Prenatal Osteogenesis

PubMed Central

Lambi, Alex G.; Pankratz, Talia L.; Mundy, Christina; Gannon, Maureen; Barbe, Mary F.; Richtsmeier, Joan T.; Popoff, Steven N.

2013-01-01

Background Connective tissue growth factor (CTGF/CCN2) is a matricellular protein that is highly expressed during bone development. Mice with global CTGF ablation (knockout, KO) have multiple skeletal dysmorphisms and perinatal lethality. A quantitative analysis of the bone phenotype has not been conducted. Results We demonstrated skeletal site-specific changes in growth plate organization, bone microarchitecture, and shape and gene expression levels in CTGF KO compared with wild-type mice. Growth plate malformations included reduced proliferation zone and increased hypertrophic zone lengths. Appendicular skeletal sites demonstrated decreased metaphyseal trabecular bone, while having increased mid-diaphyseal bone and osteogenic expression markers. Axial skeletal analysis showed decreased bone in caudal vertebral bodies, mandibles, and parietal bones in CTGF KO mice, with decreased expression of osteogenic markers. Analysis of skull phenotypes demonstrated global and regional differences in CTGF KO skull shape resulting from allometric (size-based) and nonallometric shape changes. Localized differences in skull morphology included increased skull width and decreased skull length. Dysregulation of the transforming growth factor-β-CTGF axis coupled with unique morphologic traits provides a potential mechanistic explanation for the skull phenotype. Conclusions We present novel data on a skeletal phenotype in CTGF KO mice, in which ablation of CTGF causes site-specific aberrations in bone formation. PMID:23073844

Pilot study to establish a nasal tip prediction method from unknown human skeletal remains for facial reconstruction and skull photo superimposition as applied to a Japanese male populations.

PubMed

Utsuno, Hajime; Kageyama, Toru; Uchida, Keiichi; Kibayashi, Kazuhiko; Sakurada, Koichi; Uemura, Koichi

2016-02-01

Skull-photo superimposition is a technique used to identify the relationship between the skull and a photograph of a target person: and facial reconstruction reproduces antemortem facial features from an unknown human skull, or identifies the facial features of unknown human skeletal remains. These techniques are based on soft tissue thickness and the relationships between soft tissue and the skull, i.e., the position of the ear and external acoustic meatus, pupil and orbit, nose and nasal aperture, and lips and teeth. However, the ear and nose region are relatively difficult to identify because of their structure, as the soft tissues of these regions are lined with cartilage. We attempted to establish a more accurate method to determine the position of the nasal tip from the skull. We measured the height of the maxilla and mid-lower facial region in 55 Japanese men and generated a regression equation from the collected data. We obtained a result that was 2.0±0.99mm (mean±SD) distant from the true nasal tip, when applied to a validation set consisting of another 12 Japanese men. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Coupling of a finite element human head model with a lumped parameter Hybrid III dummy model: preliminary results.

PubMed

Ruan, J S; Prasad, P

1995-08-01

A skull-brain finite element model of the human head has been coupled with a multilink rigid body model of the Hybrid III dummy. The experimental coupled model is intended to represent anatomically a 50th percentile human to the extent the dummy and the skull-brain model represent a human. It has been verified by simulating several human cadaver head impact tests as well as dummy head 'impacts" during barrier crashes in an automotive environment. Skull-isostress and brain-isostrain response curves were established based on model calibration of experimental human cadaver tolerance data. The skull-isostress response curve agrees with the JARI Human Head Impact Tolerance Curve for skull fracture. The brain-isostrain response curve predicts a higher G level for concussion than does the JARI concussion curve and the Wayne State Tolerance Curve at the longer time duration range. Barrier crash simulations consist of belted dummies impacting an airbag, a hard and soft steering wheel hub, and no head contact with vehicle interior components. Head impact force, intracranial pressures and strains, skull stress, and head center-of-gravity acceleration were investigated as injury parameters. Head injury criterion (HIC) was also calculated along with these parameters. Preliminary results of the model simulations in those impact conditions are discussed.

Anastomoses between lower cranial and upper cervical nerves: a comprehensive review with potential significance during skull base and neck operations, part I: trigeminal, facial, and vestibulocochlear nerves.

PubMed

Shoja, Mohammadali M; Oyesiku, Nelson M; Griessenauer, Christoph J; Radcliff, Virginia; Loukas, Marios; Chern, Joshua J; Benninger, Brion; Rozzelle, Curtis J; Shokouhi, Ghaffar; Tubbs, R Shane

2014-01-01

Descriptions of the anatomy of the neural communications among the cranial nerves and their branches is lacking in the literature. Knowledge of the possible neural interconnections found among these nerves may prove useful to surgeons who operate in these regions to avoid inadvertent traction or transection. We review the literature regarding the anatomy, function, and clinical implications of the complex neural networks formed by interconnections among the lower cranial and upper cervical nerves. A review of germane anatomic and clinical literature was performed. The review is organized in two parts. Part I concerns the anastomoses between the trigeminal, facial, and vestibulocochlear nerves or their branches with any other nerve trunk or branch in the vicinity. Part II concerns the anastomoses among the glossopharyngeal, vagus, accessory and hypoglossal nerves and their branches or among these nerves and the first four cervical spinal nerves; the contribution of the autonomic nervous system to these neural plexuses is also briefly reviewed. Part I is presented in this article. An extensive anastomotic network exists among the lower cranial nerves. Knowledge of such neural intercommunications is important in diagnosing and treating patients with pathology of the skull base. Copyright © 2013 Wiley Periodicals, Inc.

A comprehensive review with potential significance during skull base and neck operations, Part II: glossopharyngeal, vagus, accessory, and hypoglossal nerves and cervical spinal nerves 1-4.

PubMed

Shoja, Mohammadali M; Oyesiku, Nelson M; Shokouhi, Ghaffar; Griessenauer, Christoph J; Chern, Joshua J; Rizk, Elias B; Loukas, Marios; Miller, Joseph H; Tubbs, R Shane

2014-01-01

Knowledge of the possible neural interconnections found between the lower cranial and upper cervical nerves may prove useful to surgeons who operate on the skull base and upper neck regions in order to avoid inadvertent traction or transection. We review the literature regarding the anatomy, function, and clinical implications of the complex neural networks formed by interconnections between the lower cranial and upper cervical nerves. A review of germane anatomic and clinical literature was performed. The review is organized into two parts. Part I discusses the anastomoses between the trigeminal, facial, and vestibulocochlear nerves or their branches and other nerve trunks or branches in the vicinity. Part II deals with the anastomoses between the glossopharyngeal, vagus, accessory and hypoglossal nerves and their branches or between these nerves and the first four cervical spinal nerves; the contribution of the autonomic nervous system to these neural plexuses is also briefly reviewed. Part II is presented in this article. Extensive and variable neural anastomoses exist between the lower cranial nerves and between the upper cervical nerves in such a way that these nerves with their extra-axial communications can be collectively considered a plexus. Copyright © 2013 Wiley Periodicals, Inc.

A watertight acrylic-free titanium recording chamber for electrophysiology in behaving monkeys

PubMed Central

Economides, John R.; Jocson, Cristina M.; Parker, John M.; Horton, Jonathan C.

2011-01-01

Neurophysiological recording in alert monkeys requires the creation of a permanent aperture in the skull for repeated insertion of microelectrodes. Most laboratories use polymethyl methacrylate to attach a recording chamber over the skull opening. Here, we describe a titanium chamber that fastens to the skull with screws, using no polymethyl methacrylate. The gap between the base of the chamber and the skull is filled with hydroxyapatite, forming a watertight gasket. As the chamber base osseointegates with the skull, the hydroxyapatite is replaced with bone. Rather than having a finite lifetime, the recording chamber becomes more firmly anchored the longer it is in place. It has a small footprint, low profile, and needs little maintenance to control infection. Toilette consists of occasional application of betadine to clean the scalp margin, followed by application of neomycin, polymyxin, and bacitracin ointment. Antibiotic is also placed inside the chamber to suppress bacterial proliferation. Thickening of the dura within the chamber can be prevented by regular application of mitocycin C and/or bevacizumab, an antibody against vascular endothelial growth factor. By conducting an e-mail survey, this protocol for chamber maintenance was compared with procedures used in 37 other vision research laboratories. Refinement of appliances and techniques used for recordings in awake monkeys promises to increase the pace of scientific discovery and to benefit animal welfare. PMID:21676928

Diet and morphology of extant and recently extinct northern bears

USGS Publications Warehouse

Mattson, David J.

1998-01-01

I examined the relationship of diets to skull morphology of extant northern bears and used this information to speculate on diets of the recently extinct cave (Ursus spelaeus) and short-faced (Arctodus simus) bears. Analyses relied upon published skull measurements and food habits of Asiatic (U. thibetanus) and American (U. americanus) black bears, polar bears (U. maritimus), various subspecies of brown bears (U. arctos), and the giant panda (Ailuropoda melanoleuca). Principal components analysis showed major trends in skull morphology related to size, crushing force, and snout shape. Giant pandas, short-faced bears, cave bears, and polar bears exhibited extreme features along these gradients. Diets of brown bears in colder, often non-forested environments were distinguished by large volumes of roots, foliage, and vertebrates, while diets of the 2 black bear species and brown bears occupying broadleaf forests contained greater volumes of mast and invertebrates and overlapped considerably. Fractions of fibrous foods in feces (foliage and roots) were strongly related to skull morphology (R2=0.97)">(R2=0.97). Based on this relationship, feces of cave and short-faced bears were predicted to consist almost wholly of foliage, roots, or both. I hypothesized that cave bears specialized in root grubbing. In contrast, based upon body proportions and features of the ursid digestive tract, I hypothesized that skull features associated with crushing force facilitated a carnivorous rather than herbivorous diet for short-faced bears.

Scalp and skull influence on near infrared photon propagation in the Colin27 brain template.

PubMed

Strangman, Gary E; Zhang, Quan; Li, Zhi

2014-01-15

Near-infrared neuromonitoring (NIN) is based on near-infrared spectroscopy (NIRS) measurements performed through the intact scalp and skull. Despite the important effects of overlying tissue layers on the measurement of brain hemodynamics, the influence of scalp and skull on NIN sensitivity are not well characterized. Using 3555 Monte Carlo simulations, we estimated the sensitivity of individual continuous-wave NIRS measurements to brain activity over the entire adult human head by introducing a small absorption perturbation to brain gray matter and quantifying the influence of scalp and skull thickness on this sensitivity. After segmenting the Colin27 template into five tissue types (scalp, skull, cerebrospinal fluid, gray matter and white matter), the average scalp thickness was 6.9 ± 3.6 mm (range: 3.6-11.2mm), while the average skull thickness was 6.0 ± 1.9 mm (range: 2.5-10.5mm). Mean NIN sensitivity - defined as the partial path length through gray matter divided by the total photon path length - ranged from 0.06 (i.e., 6% of total path length) at a 20mm source-detector separation, to over 0.19 at 50mm separations. NIN sensitivity varied substantially around the head, with occipital pole exhibiting the highest NIRS sensitivity to gray matter, whereas inferior frontal regions had the lowest sensitivity. Increased scalp and skull thickness were strongly associated with decreased sensitivity to brain tissue. Scalp thickness always exhibited a slightly larger effect on sensitivity than skull thickness, but the effect of both varied with SD separation. We quantitatively characterize sensitivity around the head as well as the effects of scalp and skull, which can be used to interpret NIN brain activation studies as well as guide the design, development and optimization of NIRS devices and sensors. Copyright © 2013 Elsevier Inc. All rights reserved.

How to Make a Bird Skull: Major Transitions in the Evolution of the Avian Cranium, Paedomorphosis, and the Beak as a Surrogate Hand.

PubMed

Bhullar, Bhart-Anjan S; Hanson, Michael; Fabbri, Matteo; Pritchard, Adam; Bever, Gabe S; Hoffman, Eva

2016-09-01

The avian skull is distinctive in its construction and in its function. Much of bird anatomical variety is expressed in the beak; but the beak itself, largely formed of the premaxillary bone, is set upon a shortened face and a bulbous, enlarged braincase. Here, we use original anatomical observations and reconstructions to describe the overall form of the avian skull in a larger context and to provide a general account of the evolutionary transformation from the early dinosaur skull-the skull of an archosaurian macropredator-to that of modern birds. Facial shortening, the enlargement of the braincase around an enlarged brain (with consequential reduction of circumorbital elements and the adductor chamber), and general thinning and looser articulation of bones are trends. Many of these owe to juvenilization or paedomorphosis, something that is abundantly evident from comparison of a juvenile early theropod (Coelophysis) to early avialans like Archaeopteryx Near the avian crown, the premaxilla becomes dramatically enlarged and integrated into the characteristic mobile kinetic system of birds. We posit that this addition of a large element onto the skull may be biomechanically feasible only because of the paedomorphic shortening of the face; and kinesis of the beak only because of the paedomorphic thinning of the bones and loosening of articulations, as played out in reverse during the maturation of Coelophysis Finally, the beak itself becomes elaborated as the hands are integrated into the wing. There are structural, kinematic, and neurological similarities between avian pecking and primate grasping. The ability to precision-select high-quality food against a complex but depauperate background may have permitted crown birds to survive the end-Cretaceous cataclysm by feeding on insects, seeds, and other detritus after the collapse of higher trophic levels in the food web. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Prevertebral corridor: posterior pathway for reconstruction of the ventral skull base.

PubMed

Durmaz, Abdullah; Fernandez-Miranda, Juan; Snyderman, Carl H; Rivera-Serrano, Carlos; Tosun, Fuat

2011-05-01

Regional vascularized flaps, such as the pericranial and temporoparietal fascia flaps, are currently used for reconstruction of skull base defects after endoscopic endonasal surgery whenever local vascularized flaps, such as the nasoseptal flap, are not available. Two different transposition pathways, infratemporal transpterygoid and subfrontal, have been proposed for regional flaps. The objective of this study was to describe and assess the feasibility of the transposition of a vascularized pedicled flap from the occipital galeopericranium via the prevertebral space corridor into the nasopharynx. Ten heads were injected with colored silicone. An endoscopic endonasal anterior craniofacial resection and panclival approach were performed in each specimen. The occipital flap was harvested using a previously described technique. The prevertebral corridor, extending from the neck to the nasopharynx, was dissected superficial to the paraspinal muscles. Computed tomography-based image guidance was used to assess the relationship between the corridor and adjacent neurovascular structures. Length of the corridor and pedicle and area of the donor flap were measured. The flap was harvested and successfully transposed into the nasopharynx using the proposed corridor in all studied specimens (10 heads, 20 sides). All flaps provided complete coverage of the skull base defects. The average length of the pedicle was 70.5 (SD, 6.5) mm, and the average length and width of the flap were 99.9 (SD, 14.6) mm and 59.3 (SD, 10.9) mm, respectively. The average length of the prevertebral corridor was 49.7 (SD, 4.8) mm. The occipital flap has favorable anatomic characteristics for use in skull base reconstruction. Transposition of the flap via the prevertebral corridor is a suitable option for vascularized reconstruction of expanded endonasal skull base defects when other local or regional flaps are not available. Additional clinical studies are necessary to define its role in endoscopic endonasal surgery.

Challenges in Linear Accelerator Radiotherapy for Chordomas and Chondrosarcomas of the Skull Base: Focus on Complications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hauptman, Jason S., E-mail: jhauptman@mednet.ucla.edu; Barkhoudarian, Garni; Safaee, Michael

2012-06-01

Purpose: Intracranial chordomas and chondrosarcomas are histologically low-grade, locally invasive tumors that infiltrate the skull base. Currently, consensus therapy includes surgical resection and adjuvant radiotherapy. Radiation delivery is typically limited by the proximity of these tumors to critical skull base structures. Methods: This is a retrospective review of 13 cases of chordomas and 2 cases of chondroid chondrosarcomas of the skull based treated with linear accelerator stereotactic radiotherapy (SRT, n = 10) or stereotactic radiosurgery (SRS, n = 5). The average time to the most recent follow-up visit was 4.5 years. The tumor characteristics, treatment details, and outcomes were recorded.more » Each radiation plan was reviewed, and the dosage received by the brainstem, optic apparatus, and pituitary was calculated. Results: Of the 10 patients treated with SRT, 6 were found to have unchanged or decreased tumor size as determined from radiographic follow-up. Of the 5 patients treated with SRS, 3 were found to have stable or unchanged tumors at follow-up. The complications included 1 SRT patient who developed endocrinopathy, 2 patients (1 treated with SRS and the other with SRT), who developed cranial neuropathy, and 1 SRS patient who developed visual deficits. Additionally, 1 patient who received both SRS and SRT within 2 years for recurrence experienced transient medial temporal lobe radiation changes that resolved. Conclusions: Where proton beam therapy is unavailable, linear accelerator-based SRT or radiosurgery remains a safe option for adjuvant therapy of chordomas and chondrosarcomas of the skull base. The exposure of the optic apparatus, pituitary stalk, and brainstem must be considered during planning to minimize complications. If the optic apparatus is included in the 80% isodose line, it might be best to fractionate therapy. Exposure of the pituitary stalk should be kept to <30 Gy to minimize endocrine dysfunction. Brainstem exposure should be limited to <60 Gy in fractions.« less

Skull counting in late stages after internal contamination by actinides.

PubMed

Tani, Kotaro; Shutt, Arron; Kurihara, Osamu; Kosako, Toshiso

2015-02-01

Monitoring preparation for internal contamination with actinides (e.g. Pu and Am) is required to assess internal doses at nuclear fuel cycle-related facilities. In this paper, the authors focus on skull counting in case of single-incident inhalation of (241)Am and propose an effective procedure for skull counting with an existing system, taking into account the biokinetic behaviour of (241)Am in the human body. The predicted response of the system to skull counting under a certain counting geometry was found to be only ∼1.0 × 10(-5) cps Bq(-1) 1y after intake. However, this disadvantage could be remedied by repeated measurements of the skull during the late stage of the intake due to the predicted response reaching a plateau at about the 1000th day after exposure and exceeding that in the lung counting. Further studies are needed for the development of a new detection system with higher sensitivity to perform reliable internal dose estimations based on direct measurements. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Descriptive Anatomy and Three-Dimensional Reconstruction of the Skull of the Early Tetrapod Acanthostega gunnari Jarvik, 1952

PubMed Central

Porro, Laura B.; Rayfield, Emily J.; Clack, Jennifer A.

2015-01-01

The early tetrapod Acanthostega gunnari is an iconic fossil taxon exhibiting skeletal morphology reflecting the transition of vertebrates from water onto land. Computed tomography data of two Acanthostega skulls was segmented using visualization software to digitally separate bone from matrix and individual bones of the skull from each other. A revised description of cranial and lower jaw anatomy in this taxon based on CT data includes new details of sutural morphology, the previously undescribed quadrate and articular bones, and the mandibular symphysis. Sutural morphology is used to infer loading regime in the skull during feeding, and suggests Acanthostega used its anterior jaws to initially seize prey while smaller posterior teeth were used to restrain struggling prey during ingestion. Novel methods were used to repair and retrodeform the skull, resulting in a three-dimensional digital reconstruction that features a longer postorbital region and more strongly hooked anterior lower jaw than previous attempts while supporting the presence of a midline gap between the nasals and median rostrals. PMID:25760343

Use of titanium mesh for reconstruction of large anterior cranial base defects.

PubMed

Badie, B; Preston, J K; Hartig, G K

2000-10-01

The authors evaluated the role of titanium mesh used in combination with vascularized pericranium to provide rigid support during reconstruction of anterior skull base defects. Thirteen patients with large anterior skull base defects caused by tumor invasion or traumatic injury involving the cribriform plate, orbital roof, and planum sphenoidale were included in the study. The reconstruction technique involved placement of titanium mesh between two layers of continuous vascularized pericranium. Surgical glue and routine lumbar cerebrospinal fluid (CSF) drainage were not used in any patient. At a mean postoperative follow-up time of 22 months (range 8-39 months), none of the patients had developed infection or meningocele. Postoperative CSF rhinorrhea occurred in two patients with extensive dural defects, which resolved with temporary lumbar drainage. Use of titanium mesh and a two-layer vascularized pericranial graft is a safe, reproducible, and feasible method for reconstructing the anterior skull base. Patients with large dural defects may need temporary CSF diversion to avoid postoperative fistula formation.

Molecular genetics of craniosynostosis

NASA Astrophysics Data System (ADS)

Caterine; Auerkari, Elza Ibrahim

2018-03-01

Tight regulation process and complex interplay occur along the osteogenic interfaces of the cranial sutures in normal growth and development of the skull. Cranial sutures serve as sites of bone growth while maintaining a state of patency to accommodate the developing brain. Cranial sutures are fibro-cellular structures that separate the rigid plates of the skull bones. Premature fusion of one or more cranial sutures leads to a condition known as craniosynostosis. Craniosynostosis is one of the most common craniofacial anomalies with a prevalence of 1 in 2,500 newborns. Several genes have been identified in the pathogenesis of craniosynostosis. Molecular signaling events and the intracellular signal transduction pathways implicated in the suture pathobiology will provide a useful approach for therapeutic targeting.

Formation and Rupture of the Internal Carotid Artery Aneurysm after Multiple Courses of Intensity-Modulated Radiation Therapy for Management of the Skull Base Ewing Sarcoma/PNET: Case Report.

PubMed

Tamura, Manabu; Kogo, Kasei; Masuo, Osamu; Oura, Yoshinori; Matsumoto, Hiroyuki; Fujita, Koji; Nakao, Naoyuki; Uematsu, Yuji; Itakura, Toru; Chernov, Mikhail; Hayashi, Motohiro; Muragaki, Yoshihiro; Iseki, Hiroshi

2013-12-01

Background Aneurysm formation after stereotactic irradiation of skull base tumors is rare. The formation and rupture of an internal carotid artery (ICA) aneurysm in a patient with skull base Ewing sarcoma/primitive neuroectodermal tumor (PNET), who underwent surgery followed by multiple courses of intensity-modulated radiation therapy (IMRT) and chemotherapy, is described. Case Description A 25-year-old man presented with a sinonasal tumor with intraorbital and intracranial growth. At that time cerebral angiography did not reveal any vascular abnormalities. The lesion was resected subtotally. Histopathologic diagnosis was Ewing sarcoma/PNET. The patient underwent multiple courses of chemotherapy and three courses of IMRT at 3, 28, and 42 months after initial surgery. The total biologically effective dose delivered to the right ICA was 220.2 Gy. Seven months after the third IMRT, the patient experienced profound nasal bleeding that resulted in hypovolemic shock. Angiography revealed a ruptured right C4-C5 aneurysm and irregular stenotic changes of the ICA. Lifesaving endovascular trapping of the right ICA was done. The patient recovered well after surgery but died due to tumor recurrence 6 months later. Conclusion Excessive irradiation of the ICA may occasionally result in aneurysm formation, which should be borne in mind during stereotactic irradiation of malignant skull base tumors.

Treatment of anterior skull base defects by a transnasal endoscopic approach in children.

PubMed

Di Rocco, Federico; Couloigner, Vincent; Dastoli, Patricia; Sainte-Rose, Christian; Zerah, Michel; Roger, Gilles

2010-11-01

The object of this study was to assess the efficacy and complications of endoscopic management of anterior skull base defects. The authors reviewed the medical records of 28 children (20 boys and 8 girls) undergoing endoscopic repair of anterior skull base defects in their tertiary referral center between 2001 and 2008; 18 cases were congenital and 10 cases posttraumatic. During the endoscopic procedure, rigid telescopes--2.7 or 4 mm in diameter, with 0° or 30° lenses--were used. In 23 patients the anterior skull base defect was sealed with fragments of middle turbinate (bone and mucosa). In the remaining 5 patients it was sealed with cartilage harvested from the nasal septum (3 cases) or from the auricle (2 cases), fibrin glue, and oxidized cellulose. A combined external and endoscopic approach was required in 3 cases because of the size and extensions of the encephalocele. Outcome was primarily assessed by means of clinical examination, nasal fibroscopy, and imaging. The mean duration of follow-up was 26.7 months (range 9-57 months). One patient treated by a combined approach died of meningitis 2 years after surgery. In the remaining 27 patients, there was no recurrence of CSF leak, meningitis, or encephalocele. An iatrogenic frontal or ethmoidal mucocele was observed in 4 cases. The endoscopic approach is a minimally invasive, safe, and efficient technique for removing nasal encephaloceles in children.

Transsphenoidal Approach in Endoscopic Endonasal Surgery for Skull Base Lesions: What Radiologists and Surgeons Need to Know.

PubMed

García-Garrigós, Elena; Arenas-Jiménez, Juan José; Monjas-Cánovas, Irene; Abarca-Olivas, Javier; Cortés-Vela, Jesús Julián; De La Hoz-Rosa, Javier; Guirau-Rubio, Maria Dolores

2015-01-01

In the last 2 decades, endoscopic endonasal transsphenoidal surgery has become the most popular choice of neurosurgeons and otolaryngologists to treat lesions of the skull base, with minimal invasiveness, lower incidence of complications, and lower morbidity and mortality rates compared with traditional approaches. The transsphenoidal route is the surgical approach of choice for most sellar tumors because of the relationship of the sphenoid bone to the nasal cavity below and the pituitary gland above. More recently, extended approaches have expanded the indications for transsphenoidal surgery by using different corridors leading to specific target areas, from the crista galli to the spinomedullary junction. Computer-assisted surgery is an evolving technology that allows real-time anatomic navigation during endoscopic surgery by linking preoperative triplanar radiologic images and intraoperative endoscopic views, thus helping the surgeon avoid damage to vital structures. Preoperative computed tomography is the preferred modality to show bone landmarks and vascular structures. Radiologists play an important role in surgical planning by reporting extension of sphenoid pneumatization, recesses and septations of the sinus, and other relevant anatomic variants. Radiologists should understand the relationships of the sphenoid bone and skull base structures, anatomic variants, and image-guided neuronavigation techniques to prevent surgical complications and allow effective treatment of skull base lesions with the endoscopic endonasal transsphenoidal approach. ©RSNA, 2015.

Transcranial ultrasonic therapy based on time reversal of acoustically induced cavitation bubble signature

PubMed Central

Gâteau, Jérôme; Marsac, Laurent; Pernot, Mathieu; Aubry, Jean-Francois; Tanter, Mickaël; Fink, Mathias

2010-01-01

Brain treatment through the skull with High Intensity Focused Ultrasound (HIFU) can be achieved with multichannel arrays and adaptive focusing techniques such as time-reversal. This method requires a reference signal to be either emitted by a real source embedded in brain tissues or computed from a virtual source, using the acoustic properties of the skull derived from CT images. This non-invasive computational method focuses with precision, but suffers from modeling and repositioning errors that reduce the accessible acoustic pressure at the focus in comparison with fully experimental time-reversal using an implanted hydrophone. In this paper, this simulation-based targeting has been used experimentally as a first step for focusing through an ex vivo human skull at a single location. It has enabled the creation of a cavitation bubble at focus that spontaneously emitted an ultrasonic wave received by the array. This active source signal has allowed 97%±1.1% of the reference pressure (hydrophone-based) to be restored at the geometrical focus. To target points around the focus with an optimal pressure level, conventional electronic steering from the initial focus has been combined with bubble generation. Thanks to step by step bubble generation, the electronic steering capabilities of the array through the skull were improved. PMID:19770084

Antiquity and geographic distribution of cranial modification among the prehistoric groups of Fuego-Patagonia, Chile.

PubMed

Alfonso-Durrruty, Marta P; Giles, Bretton T; Misarti, Nicole; San Roman, Manuel; Morello, Flavia

2015-12-01

Nineteenth and twentieth century documents testify that four ethnic groups, generally classified as terrestrial hunters or canoe nomads, inhabited Fuego-Patagonia. Archaeologically, however, their presence and temporal depth remains unknown. This study analyzes the antiquity and geographic distribution of cranial modification, a highly visible symbol of social identity, in Fuego-Patagonia, Chile, to assess whether it expressed ethnic affiliation. A total of 60 adult skulls from Southern Patagonia (n = 32; 53.3%) and Tierra del Fuego (n = 28; 46.7%) were examined for age-at-death, sex and cranial modification with standard methods. Individuals were further categorized as terrestrial (n = 26; 43.3%), marine (n = 21; 35%) or indetermined hunter-gatherers (n = 13; 21.7%) based on the archaeological site's characteristics, geographic location, and isotopic information. Thirty percent (n = 18) of the skulls in this study were modified, and most of the modified skulls (n = 15) presented a tabular-erect shape. No statistically significant differences were identified between Fuegians and Patagonians, males or females, or between the different types of adaptation and geographic locations. Thus, this Late Holocene, widely distributed practice, was not a reflection of ethnicity, but a material expression of information circulation and the complex social relations that these small-size groups had with one another. These results suggest that the emergence of modern ethnic identities in the region is a historic process that resulted from the interaction of local groups with European and Criollos. © 2015 Wiley Periodicals, Inc.

Influence of anisotropic conductivity in the skull and white matter on transcranial direct current stimulation via an anatomically realistic finite element head model

NASA Astrophysics Data System (ADS)

Suh, Hyun Sang; Lee, Won Hee; Kim, Tae-Seong

2012-11-01

To establish safe and efficient transcranial direct current stimulation (tDCS), it is of particular importance to understand the electrical effects of tDCS in the brain. Since the current density (CD) and electric field (EF) in the brain generated by tDCS depend on various factors including complex head geometries and electrical tissue properties, in this work, we investigated the influence of anisotropic conductivity in the skull and white matter (WM) on tDCS via a 3D anatomically realistic finite element head model. We systematically incorporated various anisotropic conductivity ratios into the skull and WM. The effects of anisotropic tissue conductivity on the CD and EF were subsequently assessed through comparisons to the conventional isotropic solutions. Our results show that the anisotropic skull conductivity significantly affects the CD and EF distribution: there is a significant reduction in the ratio of the target versus non-target total CD and EF on the order of 12-14%. In contrast, the WM anisotropy does not significantly influence the CD and EF on the targeted cortical surface, only on the order of 1-3%. However, the WM anisotropy highly alters the spatial distribution of both the CD and EF inside the brain. This study shows that it is critical to incorporate anisotropic conductivities in planning of tDCS for improved efficacy and safety.

Aberration correction for transcranial photoacoustic tomography of primates employing adjunct image data

NASA Astrophysics Data System (ADS)

Huang, Chao; Nie, Liming; Schoonover, Robert W.; Guo, Zijian; Schirra, Carsten O.; Anastasio, Mark A.; Wang, Lihong V.

2012-06-01

A challenge in photoacoustic tomography (PAT) brain imaging is to compensate for aberrations in the measured photoacoustic data due to their propagation through the skull. By use of information regarding the skull morphology and composition obtained from adjunct x-ray computed tomography image data, we developed a subject-specific imaging model that accounts for such aberrations. A time-reversal-based reconstruction algorithm was employed with this model for image reconstruction. The image reconstruction methodology was evaluated in experimental studies involving phantoms and monkey heads. The results establish that our reconstruction methodology can effectively compensate for skull-induced acoustic aberrations and improve image fidelity in transcranial PAT.

Motor evoked potential monitoring of the vagus nerve with transcranial electrical stimulation during skull base surgeries.

PubMed

Ito, Eiji; Ichikawa, Masahiro; Itakura, Takeshi; Ando, Hitoshi; Matsumoto, Yuka; Oda, Keiko; Sato, Taku; Watanabe, Tadashi; Sakuma, Jun; Saito, Kiyoshi

2013-01-01

Dysphasia is one of the most serious complications of skull base surgeries and results from damage to the brainstem and/or cranial nerves involved in swallowing. Here, the authors propose a method to monitor the function of the vagus nerve using endotracheal tube surface electrodes and transcranial electrical stimulation during skull base surgeries. Fifteen patients with skull base or brainstem tumors were enrolled. The authors used surface electrodes of an endotracheal tube to record compound electromyographic responses from the vocalis muscle. Motor neurons were stimulated using corkscrew electrodes placed subdermally on the scalp at C3 and C4. During surgery, the operator received a warning when the amplitude of the vagal motor evoked potential (MEP) decreased to less than 50% of the control level. After surgery, swallowing function was assessed clinically using grading criteria. In 5 patients, vagal MEP amplitude permanently deteriorated to less than 50% of the control level on the right side when meningiomas were dissected from the pons or basilar artery, or when a schwannoma was dissected from the vagal rootlets. These 5 patients had postoperative dysphagia. At 4 weeks after surgery, 2 patients still had dysphagia. In 2 patients, vagal MEPs of one side transiently disappeared when the tumors were dissected from the brainstem or the vagal rootlets. After surgery, both patients had dysphagia, which recovered in 4 weeks. In 7 patients, MEP amplitude was consistent, maintaining more than 50% of the control level throughout the operative procedures. After surgery all 7 patients were neurologically intact with normal swallowing function. Vagal MEP monitoring with transcranial electrical stimulation and endotracheal tube electrode recording was a safe and effective method to provide continuous real-time information on the integrity of both the supranuclear and infranuclear vagal pathway. This method is useful to prevent intraoperative injury of the brainstem corticobulbar tract or the vagal rootlets and to avoid the postoperative dysphagia that is often associated with brainstem or skull base surgeries.

Prospective analysis of neuropsychological deficits following resection of benign skull base meningiomas.

PubMed

Zweckberger, Klaus; Hallek, Eveline; Vogt, Lidia; Giese, Henrik; Schick, Uta; Unterberg, Andreas W

2017-12-01

OBJECTIVE Resection of skull base tumors is challenging. The introduction of alternative treatment options, such as radiotherapy, has sparked discussion regarding outcome in terms of quality of life and neuropsychological deficits. So far, however, no prospective data are available on this topic. METHODS A total of 58 patients with skull base meningiomas who underwent surgery for the first time were enrolled in this prospective single-center trial. The average age of the patients was 56.4 ± 12.5 years. Seventy-nine percent of the tumors were located within the anterior skull base. Neurological examinations and neuropsychological testing were performed at 3 time points: 1 day prior to surgery (T1), 3-5 months after surgery (T2), and 9-12 months after surgery (T3). The average follow-up duration was 13.8 months. Neuropsychological assessment consisted of quality of life, depression and anxiety, verbal learning and memory, cognitive speed, attention and concentration, figural memory, and visual-motor speed. RESULTS Following surgery, 23% of patients showed transient neurological deficits and 12% showed permanent new neurological deficits with varying grades of manifestation. Postoperative quality of life, however, remained stable and was slightly improved at follow-up examinations at T3 (60.6 ± 21.5 vs 63.6 ± 24.1 points), and there was no observed effect on anxiety and depression. Long-term verbal memory, working memory, and executive functioning were slightly affected within the first months following surgery and appeared to be the most vulnerable to impairment by the tumor or the resection but were stable or improved in the majority of patients at long-term follow-up examinations after 1 year. CONCLUSIONS This report describes the first prospective study of neuropsychological outcomes following resection of skull base meningiomas and, as such, contributes to a better understanding of postoperative impairment in these patients. Despite deterioration in a minority of patients on subscales of the measures used, the majority demonstrated stable or improved outcome at follow-up assessments.

The impact of gape on the performance of the skull in chisel-tooth digging and scratch digging mole-rats (Rodentia: Bathyergidae).

PubMed

McIntosh, Andrew F; Cox, Philip G

2016-10-01

The African mole-rats (Bathyergidae) are a family of rodents highly adapted for life underground. Previous research has shown that chisel-tooth digging mole-rats (which use their incisors to dig burrows) are clearly distinguishable from scratch diggers (which only use the forelimbs to tunnel) on the basis of morphology of the skull, and that the differences are linked to the production of high bite forces and wide gapes. We hypothesized that the skull of a chisel-tooth digging mole-rat would perform better at wider gapes than that of a scratch digging mole-rat during incisor biting. To test this hypothesis, we created finite-element models of the cranium of the scratch digging Bathyergus suillus and the chisel-tooth digging Fukomys mechowii , and loaded them to simulate incisor bites at different gapes. Muscle loads were scaled such that the ratio of force to surface area was the same in both models. We measured three performance variables: overall stress across the cranium, mechanical efficiency of biting and degree of deformation across the skull. The Fukomys model had a more efficient incisor bite at all gapes, despite having greater average stress across the skull. In addition, the Fukomys model deformed less at wider gapes, whereas the Bathyergus model deformed less at narrower gapes. These properties of the cranial morphology of Fukomys and Bathyergus are congruent with their respective chisel-tooth and scratch digging behaviours and, all other factors being equal, would enable the more efficient production of bite force at wider gapes in Fukomys . However, in vivo measurements of muscle forces and activation patterns are needed to fully understand the complex biomechanics of tooth digging.

The impact of gape on the performance of the skull in chisel-tooth digging and scratch digging mole-rats (Rodentia: Bathyergidae)

NASA Astrophysics Data System (ADS)

McIntosh, Andrew F.; Cox, Philip G.

2016-10-01

The African mole-rats (Bathyergidae) are a family of rodents highly adapted for life underground. Previous research has shown that chisel-tooth digging mole-rats (which use their incisors to dig burrows) are clearly distinguishable from scratch diggers (which only use the forelimbs to tunnel) on the basis of morphology of the skull, and that the differences are linked to the production of high bite forces and wide gapes. We hypothesized that the skull of a chisel-tooth digging mole-rat would perform better at wider gapes than that of a scratch digging mole-rat during incisor biting. To test this hypothesis, we created finite-element models of the cranium of the scratch digging Bathyergus suillus and the chisel-tooth digging Fukomys mechowii, and loaded them to simulate incisor bites at different gapes. Muscle loads were scaled such that the ratio of force to surface area was the same in both models. We measured three performance variables: overall stress across the cranium, mechanical efficiency of biting and degree of deformation across the skull. The Fukomys model had a more efficient incisor bite at all gapes, despite having greater average stress across the skull. In addition, the Fukomys model deformed less at wider gapes, whereas the Bathyergus model deformed less at narrower gapes. These properties of the cranial morphology of Fukomys and Bathyergus are congruent with their respective chisel-tooth and scratch digging behaviours and, all other factors being equal, would enable the more efficient production of bite force at wider gapes in Fukomys. However, in vivo measurements of muscle forces and activation patterns are needed to fully understand the complex biomechanics of tooth digging.

3D-printed adaptive acoustic lens as a disruptive technology for transcranial ultrasound therapy using single-element transducers.

PubMed

Maimbourg, Guillaume; Houdouin, Alexandre; Deffieux, Thomas; Tanter, Mickael; Aubry, Jean-François

2018-01-16

The development of multi-element arrays for better control of the shape of ultrasonic beams has opened the way for focusing through highly aberrating media, such as the human skull. As a result, the use of brain therapy with transcranial-focused ultrasound has rapidly grown. Although effective, such technology is expensive. We propose a disruptive, low-cost approach that consists of focusing a 1 MHz ultrasound beam through a human skull with a single-element transducer coupled with a tailored silicone acoustic lens cast in a 3D-printed mold and designed using computed tomography-based numerical acoustic simulation. We demonstrate on N  =  3 human skulls that adding lens-based aberration correction to a single-element transducer increases the deposited energy on the target 10 fold.

3D-printed adaptive acoustic lens as a disruptive technology for transcranial ultrasound therapy using single-element transducers

NASA Astrophysics Data System (ADS)

Maimbourg, Guillaume; Houdouin, Alexandre; Deffieux, Thomas; Tanter, Mickael; Aubry, Jean-François

2018-01-01

The development of multi-element arrays for better control of the shape of ultrasonic beams has opened the way for focusing through highly aberrating media, such as the human skull. As a result, the use of brain therapy with transcranial-focused ultrasound has rapidly grown. Although effective, such technology is expensive. We propose a disruptive, low-cost approach that consists of focusing a 1 MHz ultrasound beam through a human skull with a single-element transducer coupled with a tailored silicone acoustic lens cast in a 3D-printed mold and designed using computed tomography-based numerical acoustic simulation. We demonstrate on N  =  3 human skulls that adding lens-based aberration correction to a single-element transducer increases the deposited energy on the target 10 fold.

Modeling ultrasound propagation through material of increasing geometrical complexity.

PubMed

Odabaee, Maryam; Odabaee, Mostafa; Pelekanos, Matthew; Leinenga, Gerhard; Götz, Jürgen

2018-06-01

Ultrasound is increasingly being recognized as a neuromodulatory and therapeutic tool, inducing a broad range of bio-effects in the tissue of experimental animals and humans. To achieve these effects in a predictable manner in the human brain, the thick cancellous skull presents a problem, causing attenuation. In order to overcome this challenge, as a first step, the acoustic properties of a set of simple bone-modeling resin samples that displayed an increasing geometrical complexity (increasing step sizes) were analyzed. Using two Non-Destructive Testing (NDT) transducers, we found that Wiener deconvolution predicted the Ultrasound Acoustic Response (UAR) and attenuation caused by the samples. However, whereas the UAR of samples with step sizes larger than the wavelength could be accurately estimated, the prediction was not accurate when the sample had a smaller step size. Furthermore, a Finite Element Analysis (FEA) performed in ANSYS determined that the scattering and refraction of sound waves was significantly higher in complex samples with smaller step sizes compared to simple samples with a larger step size. Together, this reveals an interaction of frequency and geometrical complexity in predicting the UAR and attenuation. These findings could in future be applied to poro-visco-elastic materials that better model the human skull. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Recurrent life-threatening haemoptysis from a bleeding vertebral artery pseudoaneurysm: A diagnostic dilemma.

PubMed

Chandran, Arun; Biswas, Shubhabrata; Hartley, James Leon; Nahser, Hans Christean; Lancaster, Jeffrey; Puthuran, Mani

2016-10-01

A bleeding vertebral artery pseudoaneurysm is a rare cause of haemoptysis. Pseudoaneurysm can arise due to radionecrosis from previous radiotherapy in the base of skull and neck region and may present with haemoptysis many years later. It is important to be aware of this entity in the work-up of haemoptysis, particularly in patients with previous base of skull and neck radiotherapy. Our patient was successfully treated with endovascular occlusion. © The Author(s) 2016.

Preservation of cranial nerves during removal of the brain for an enhanced student experience in neuroanatomy classes.

PubMed

Long, Jennifer; Roberts, David J H; Pickering, James D

2014-01-01

Neuroanatomy teaching at the University of Leeds includes the examination of isolated brains by students working in small groups. This requires the prosected brains to exhibit all 12 pairs of cranial nerves. Traditional methods of removing the brain from the skull involve elevating the frontal lobes and cutting each cranial nerve as the brain is reflected posteriorly. This can leave a substantial length of each nerve attached to the skull base rather than to the removed brain. We have found a posterior approach more successful. In this study, five adult heads were disarticulated at the level of the thyroid cartilage and placed, prone, in a head stand. A wedge of bone from the occipital region was removed before the cerebellum and brainstem were elevated to visualize the cranial nerves associated with the medulla oblongata, cerebellopontine angle and mesencephalic-pontine junction prior to cutting them as close to the skull as possible. Five brains were successfully removed from the skull, each having a full complement of cranial nerves of good length attached to them. This approach significantly increases the length and number of cranial nerves remaining attached to the brain, which supports student education. For integration into head and neck dissection courses, careful consideration will be required to ensure the necks are suitably dissected and to decide whether the cranial nerves are best left attached to the skull base or brain. Copyright © 2013 Wiley Periodicals, Inc.

Evaluation of the cranial base in amnion rupture sequence involving the anterior neural tube: implications regarding recurrence risk.

PubMed

Jones, Kenneth Lyons; Robinson, Luther K; Benirschke, Kurt

2006-09-01

Amniotic bands can cause disruption of the cranial end of the developing fetus, leading in some cases to a neural tube closure defect. Although recurrence for unaffected parents of an affected child with a defect in which the neural tube closed normally but was subsequently disrupted by amniotic bands is negligible; for a primary defect in closure of the neural tube to which amnion has subsequently adhered, recurrence risk is 1.7%. In that primary defects of neural tube closure are characterized by typical abnormalities of the base of the skull, evaluation of the cranial base in such fetuses provides an approach for making a distinction between these 2 mechanisms. This distinction has implications regarding recurrence risk. The skull base of 2 fetuses with amnion rupture sequence involving the cranial end of the neural tube were compared to that of 1 fetus with anencephaly as well as that of a structurally normal fetus. The skulls were cleaned, fixed in 10% formalin, recleaned, and then exposed to 10% KOH solution. After washing and recleaning, the skulls were exposed to hydrogen peroxide for bleaching and photography. Despite involvement of the anterior neural tube in both fetuses with amnion rupture sequence, in Case 3 the cranial base was normal while in Case 4 the cranial base was similar to that seen in anencephaly. This technique provides a method for determining the developmental pathogenesis of anterior neural tube defects in cases of amnion rupture sequence. As such, it provides information that can be used to counsel parents of affected children with respect to recurrence risk.

The evolution of the complex sensory and motor systems of the human brain.

PubMed

Kaas, Jon H

2008-03-18

Inferences about how the complex sensory and motor systems of the human brain evolved are based on the results of comparative studies of brain organization across a range of mammalian species, and evidence from the endocasts of fossil skulls of key extinct species. The endocasts of the skulls of early mammals indicate that they had small brains with little neocortex. Evidence from comparative studies of cortical organization from small-brained mammals of the six major branches of mammalian evolution supports the conclusion that the small neocortex of early mammals was divided into roughly 20-25 cortical areas, including primary and secondary sensory fields. In early primates, vision was the dominant sense, and cortical areas associated with vision in temporal and occipital cortex underwent a significant expansion. Comparative studies indicate that early primates had 10 or more visual areas, and somatosensory areas with expanded representations of the forepaw. Posterior parietal cortex was also expanded, with a caudal half dominated by visual inputs, and a rostral half dominated by somatosensory inputs with outputs to an array of seven or more motor and visuomotor areas of the frontal lobe. Somatosensory areas and posterior parietal cortex became further differentiated in early anthropoid primates. As larger brains evolved in early apes and in our hominin ancestors, the number of cortical areas increased to reach an estimated 200 or so in present day humans, and hemispheric specializations emerged. The large human brain grew primarily by increasing neuron number rather than increasing average neuron size.

Investigation of standing wave formation in a human skull for a clinical prototype of a large-aperture, transcranial MR-guided Focused Ultrasound (MRgFUS) phased array: An experimental and simulation study

PubMed Central

Song, Junho; Pulkkinen, Aki; Huang, Yuexi; Hynynen, Kullervo

2014-01-01

Standing wave formation in an ex vivo human skull was investigated using a clinical prototype of a 30 cm diameter with 15 cm radius of curvature, low frequency (230 kHz), hemispherical transcranial Magnetic Resonance guided Focused Ultrasound (MRgFUS) phased-array. Experimental and simulation studies were conducted with changing aperture size and f-number configurations of the phased array, and qualitatively and quantitatively examined the acoustic pressure variation at the focus due to standing waves. The results demonstrated that the nodes and anti-nodes of standing wave produced by the small aperture array were clearly seen at approximately every 3 mm. The effect of the standing wave became more pronounced as the focus was moved closer to skull base. However, a sharp focus was seen for the full array, and there was no such standing wave pattern in the acoustic plane or near the skull base. This study showed that the fluctuation pressure amplitude would be greatly reduced by using a large-scale, hemispherical phased array with a low f-number. PMID:22049360

Influence of the cranial base flexion on Class I, II and III malocclusions: a systematic review.

PubMed

Almeida, Kélei Cristina Mathias de; Raveli, Taísa Boamorte; Vieira, Camila Ivini Viana; Santos-Pinto, Ary Dos; Raveli, Dirceu Barnabé

2017-01-01

The aim of this study was to perform a systematic review on the morphological characteristics of the skull base (flexion, anterior length and posterior length) and the concomitant development of malocclusions, by comparing differences in dimorphism, ethnicity and age. The articles were selected by means of electronic search on BBO, MEDLINE and LILACS databases from 1966 to 2016. A qualitative evaluation of the methodologies used on the articles was also performed. Although the literature on this topic is abundant, only 16 articles were selected for the present systematic review. The cranial base angle itself does not seem to play a significant role in the development of malocclusions. In fact, the cranial base angle is relatively stable at the ages of 5 to 15 years. A more obtuse angle at the skull base, in association or not with a greater anterior length of the cranial base, can contribute to the development of Class II division 1 malocclusions. On the other hand, a more acute angle at the skull base can contribute to a more anterior positioning of the mandible and to the development of Class III malocclusions.

Influence of the cranial base flexion on Class I, II and III malocclusions: a systematic review

PubMed Central

de Almeida, Kélei Cristina Mathias; Raveli, Taísa Boamorte; Vieira, Camila Ivini Viana; dos Santos-Pinto, Ary; Raveli, Dirceu Barnabé

2017-01-01

ABSTRACT Objective: The aim of this study was to perform a systematic review on the morphological characteristics of the skull base (flexion, anterior length and posterior length) and the concomitant development of malocclusions, by comparing differences in dimorphism, ethnicity and age. Methods: The articles were selected by means of electronic search on BBO, MEDLINE and LILACS databases from 1966 to 2016. A qualitative evaluation of the methodologies used on the articles was also performed. Results: Although the literature on this topic is abundant, only 16 articles were selected for the present systematic review. The cranial base angle itself does not seem to play a significant role in the development of malocclusions. In fact, the cranial base angle is relatively stable at the ages of 5 to 15 years. Conclusions: A more obtuse angle at the skull base, in association or not with a greater anterior length of the cranial base, can contribute to the development of Class II division 1 malocclusions. On the other hand, a more acute angle at the skull base can contribute to a more anterior positioning of the mandible and to the development of Class III malocclusions. PMID:29160345

If the skull fits: magnetic resonance imaging and microcomputed tomography for combined analysis of brain and skull phenotypes in the mouse

PubMed Central

Blank, Marissa C.; Roman, Brian B.; Henkelman, R. Mark; Millen, Kathleen J.

2012-01-01

The mammalian brain and skull develop concurrently in a coordinated manner, consistently producing a brain and skull that fit tightly together. It is common that abnormalities in one are associated with related abnormalities in the other. However, this is not always the case. A complete characterization of the relationship between brain and skull phenotypes is necessary to understand the mechanisms that cause them to be coordinated or divergent and to provide perspective on the potential diagnostic or prognostic significance of brain and skull phenotypes. We demonstrate the combined use of magnetic resonance imaging and microcomputed tomography for analysis of brain and skull phenotypes in the mouse. Co-registration of brain and skull images allows comparison of the relationship between phenotypes in the brain and those in the skull. We observe a close fit between the brain and skull of two genetic mouse models that both show abnormal brain and skull phenotypes. Application of these three-dimensional image analyses in a broader range of mouse mutants will provide a map of the relationships between brain and skull phenotypes generally and allow characterization of patterns of similarities and differences. PMID:22947655

Automated human skull landmarking with 2D Gabor wavelets

NASA Astrophysics Data System (ADS)

de Jong, Markus A.; Gül, Atilla; de Gijt, Jan Pieter; Koudstaal, Maarten J.; Kayser, Manfred; Wolvius, Eppo B.; Böhringer, Stefan

2018-05-01

Landmarking of CT scans is an important step in the alignment of skulls that is key in surgery planning, pre-/post-surgery comparisons, and morphometric studies. We present a novel method for automatically locating anatomical landmarks on the surface of cone beam CT-based image models of human skulls using 2D Gabor wavelets and ensemble learning. The algorithm is validated via human inter- and intra-rater comparisons on a set of 39 scans and a skull superimposition experiment with an established surgery planning software (Maxilim). Automatic landmarking results in an accuracy of 1–2 mm for a subset of landmarks around the nose area as compared to a gold standard derived from human raters. These landmarks are located in eye sockets and lower jaw, which is competitive with or surpasses inter-rater variability. The well-performing landmark subsets allow for the automation of skull superimposition in clinical applications. Our approach delivers accurate results, has modest training requirements (training set size of 30–40 items) and is generic, so that landmark sets can be easily expanded or modified to accommodate shifting landmark interests, which are important requirements for the landmarking of larger cohorts.

Medical diagnosis imaging systems: image and signal processing applications aided by fuzzy logic

NASA Astrophysics Data System (ADS)

Hata, Yutaka

2010-04-01

First, we describe an automated procedure for segmenting an MR image of a human brain based on fuzzy logic for diagnosing Alzheimer's disease. The intensity thresholds for segmenting the whole brain of a subject are automatically determined by finding the peaks of the intensity histogram. After these thresholds are evaluated in a region growing, the whole brain can be identified. Next, we describe a procedure for decomposing the obtained whole brain into the left and right cerebral hemispheres, the cerebellum and the brain stem. Our method then identified the whole brain, the left cerebral hemisphere, the right cerebral hemisphere, the cerebellum and the brain stem. Secondly, we describe a transskull sonography system that can visualize the shape of the skull and brain surface from any point to examine skull fracture and some brain diseases. We employ fuzzy signal processing to determine the skull and brain surface. The phantom model, the animal model with soft tissue, the animal model with brain tissue, and a human subjects' forehead is applied in our system. The all shapes of the skin surface, skull surface, skull bottom, and brain tissue surface are successfully determined.

Two Immigrants with Tuberculosis of the Ear, Nose, and Throat Region with Skull Base and Cranial Nerve Involvement

PubMed Central

Richardus, Renate A.; Jansen, Jeroen C.; Steens, Stefan C. A.; Arend, Sandra M.

2011-01-01

We report two immigrants with tuberculosis of the skull base and a review of the literature. A Somalian man presented with bilateral otitis media, hearing loss, and facial and abducens palsy. Imaging showed involvement of both mastoid and petrous bones, extending via the skull base to the nasopharynx, suggesting tuberculosis which was confirmed by characteristic histology and positive auramine staining, while Ziehl-Neelsen staining and PCR were negative. A Sudanese man presented with torticollis and deviation of the uvula due to paresis of N. IX and XI. Imaging showed a retropharyngeal abscess and lysis of the clivus. Histology, acid-fast staining, and PCR were negative. Both patients had a positive Quantiferon TB Gold in-tube result and improved rapidly after empiric treatment for tuberculosis. Cultures eventually yielded M. tuberculosis. These unusual cases exemplify the many faces of tuberculosis and the importance to include tuberculosis in the differential diagnosis of unexplained problems. PMID:21541186

Hypertrophic Cranial Pachymeningitis and Skull Base Osteomyelitis by Pseudomonas Aeruginosa: Case Report and Review of the Literature

PubMed Central

Caldas, Ana Rita; Brandao, Mariana; Paula, Filipe Seguro; Castro, Elsa; Farinha, Fatima; Marinho, Antonio

2012-01-01

Hypertrophic cranial pachymeningitis (HCP) is an uncommon disorder characterized by localized or diffuse thickening of the dura mater, and it usually presents with multiple cranial neurophaties. It has been associated with a variety of inflammatory, infectious, traumatic, toxic and neoplasic diseases, when no specific cause is found the process is called idiopathic. The infectious cases occur in patients under systemic immunosuppression, which have an evident contiguous source or those who have undergone neurosurgical procedures. We describe a case of a 62-year-old immunosuppressed woman with diabetes and rheumatoid arthritis, which had HCP and osteomyelitis of the skull base caused by pseudomonas aeruginosa, presenting with headache and diplopia. We believe this is the second documented case of pachymeningitis secondary to this microorganism. As a multifactorial disease, it is essencial to determine the specific causative agent of HCP before making treatment decisions, and great care is needed with immunocompromised patients. Keywords Pseudomonas aeruginosa; Hypertrophic pachymeningitis; Ophtalmoplegia, optical neuropathy; Osteomyelitis; Skull base PMID:22505989

Skull Defects in Finite Element Head Models for Source Reconstruction from Magnetoencephalography Signals

PubMed Central

Lau, Stephan; Güllmar, Daniel; Flemming, Lars; Grayden, David B.; Cook, Mark J.; Wolters, Carsten H.; Haueisen, Jens

2016-01-01

Magnetoencephalography (MEG) signals are influenced by skull defects. However, there is a lack of evidence of this influence during source reconstruction. Our objectives are to characterize errors in source reconstruction from MEG signals due to ignoring skull defects and to assess the ability of an exact finite element head model to eliminate such errors. A detailed finite element model of the head of a rabbit used in a physical experiment was constructed from magnetic resonance and co-registered computer tomography imaging that differentiated nine tissue types. Sources of the MEG measurements above intact skull and above skull defects respectively were reconstructed using a finite element model with the intact skull and one incorporating the skull defects. The forward simulation of the MEG signals reproduced the experimentally observed characteristic magnitude and topography changes due to skull defects. Sources reconstructed from measured MEG signals above intact skull matched the known physical locations and orientations. Ignoring skull defects in the head model during reconstruction displaced sources under a skull defect away from that defect. Sources next to a defect were reoriented. When skull defects, with their physical conductivity, were incorporated in the head model, the location and orientation errors were mostly eliminated. The conductivity of the skull defect material non-uniformly modulated the influence on MEG signals. We propose concrete guidelines for taking into account conducting skull defects during MEG coil placement and modeling. Exact finite element head models can improve localization of brain function, specifically after surgery. PMID:27092044

Direct phase projection and transcranial focusing of ultrasound for brain therapy.

PubMed

Pinton, Gianmarco F; Aubry, Jean-Francois; Tanter, Mickaël

2012-06-01

Ultrasound can be used to noninvasively treat the human brain with hyperthermia by focusing through the skull. To obtain an accurate focus, especially at high frequencies (>500 kHz), the phase of the transmitted wave must be modified to correct the aberrations introduced by the patient's individual skull morphology. Currently, three-dimensional finite-difference time-domain simulations are used to model a point source at the target. The outward-propagating wave crosses the measured representation of the human skull and is recorded at the therapy array transducer locations. The signal is then time reversed and experimentally transmitted back to its origin. These simulations are resource intensive and add a significant delay to treatment planning. Ray propagation is computationally efficient because it neglects diffraction and only describes two propagation parameters: the wave's direction and the phase. We propose a minimal method that is based only on the phase. The phase information is projected from the external skull surface to the array locations. This replaces computationally expensive finite-difference computations with an almost instantaneous direct phase projection calculation. For the five human skull samples considered, the phase distribution outside of the skull is shown to vary by less than λ/20 as it propagates over a 5 cm distance and the validity of phase projection is established over these propagation distances. The phase aberration introduced by the skull is characterized and is shown to have a good correspondence with skull morphology. The shape of this aberration is shown to have little variation with propagation distance. The focusing quality with the proposed phase-projection algorithm is shown to be indistinguishable from the gold-standard full finite-difference simulation. In conclusion, a spherical wave that is aberrated by the skull has a phase propagation that can be accurately described as radial, even after it has been distorted. By combining finite-difference simulations with a phase-projection algorithm, the time required for treatment planning is significantly reduced. The correlation length of the phase is used to validate the algorithm and it can also be used to provide guiding parameters for clinical array transducer design in terms of transducer spacing and phase error.

Pamidronic acid and cabergoline as effective long-term therapy in a 12-year-old girl with extended facial polyostotic fibrous dysplasia, prolactinoma and acromegaly in McCune-Albright syndrome: a case report

PubMed Central

2012-01-01

Introduction McCune-Albright syndrome is a complex inborn disorder due to early embryonal postzygotic somatic activating mutations in the GNAS1 gene. The phenotype is very heterogeneous and includes polyostotic fibrous dysplasia, typically involving the facial skull, numerous café-au-lait spots and autonomous hyperfunctions of several endocrine systems, leading to hyperthyroidism, hypercortisolism, precocious puberty and acromegaly. Case presentation Here, we describe a 12-year-old Caucasian girl with severe facial involvement of fibrous dysplasia, along with massive acromegaly due to growth hormone excess and precocious puberty, with a prolactinoma. Our patient was treated with a bisphosphonate and the prolactin antagonist, cabergoline, resulting in the inhibition of fibrous dysplasia and involution of both the prolactinoma and growth hormone excess. During a follow-up of more than two years, no severe side effects were noted. Conclusion Treatment with bisphosphonates in combination with cabergoline is a suitable option in patients with McCune-Albright syndrome, especially in order to circumvent surgical interventions in patients suffering from polyostotic fibrous dysplasia involving the skull base. PMID:22273876

Biomechanical testing of isolated bones: holographic study

NASA Astrophysics Data System (ADS)

Silvennoinen, Raimo; Nygren, Kaarlo; Karna, Markku

1992-08-01

Holographic nondestructive testing (HNDT) is used to investigate the complex structures of bones of various shapes and sizes subjected to forces. Three antlered deer skulls of different species were investigated and significant species-specific differences were observed. The HNDT method was also used to verify the advanced healing of an osteosynthetized sheep jawbone. Radioulnar bones of a normal and an orphaned moose calf were subjected to a bending test. The undernourished calf showed torsio displacement combined with the bending of the bone, which was not seen in the normal calf. The effects of the masticatory forces on the moose skull surface were studied by simulating masseter muscle contractions with jawbones in occlusion. The fringe patterns showed fast-moving bone surfaces on the naso- maxillo-lacrimal region.

High-resolution whole-genome analysis of skull base chordomas implicates FHIT loss in chordoma pathogenesis.

PubMed

Diaz, Roberto Jose; Guduk, Mustafa; Romagnuolo, Rocco; Smith, Christian A; Northcott, Paul; Shih, David; Berisha, Fitim; Flanagan, Adrienne; Munoz, David G; Cusimano, Michael D; Pamir, M Necmettin; Rutka, James T

2012-09-01

Chordoma is a rare tumor arising in the sacrum, clivus, or vertebrae. It is often not completely resectable and shows a high incidence of recurrence and progression with shortened patient survival and impaired quality of life. Chemotherapeutic options are limited to investigational therapies at present. Therefore, adjuvant therapy for control of tumor recurrence and progression is of great interest, especially in skull base lesions where complete tumor resection is often not possible because of the proximity of cranial nerves. To understand the extent of genetic instability and associated chromosomal and gene losses or gains in skull base chordoma, we undertook whole-genome single-nucleotide polymorphism microarray analysis of flash frozen surgical chordoma specimens, 21 from the clivus and 1 from C1 to C2 vertebrae. We confirm the presence of a deletion at 9p involving CDKN2A, CDKN2B, and MTAP but at a much lower rate (22%) than previously reported for sacral chordoma. At a similar frequency (21%), we found aneuploidy of chromosome 3. Tissue microarray immunohistochemistry demonstrated absent or reduced fragile histidine triad (FHIT) protein expression in 98% of sacral chordomas and 67%of skull base chordomas. Our data suggest that chromosome 3 aneuploidy and epigenetic regulation of FHIT contribute to loss of the FHIT tumor suppressor in chordoma. The finding that FHIT is lost in a majority of chordomas provides new insight into chordoma pathogenesis and points to a potential new therapeutic target for this challenging neoplasm.

Stereotactic radiotherapy using Novalis for skull base metastases developing with cranial nerve symptoms.

PubMed

Mori, Yoshimasa; Hashizume, Chisa; Kobayashi, Tatsuya; Shibamoto, Yuta; Kosaki, Katsura; Nagai, Aiko

2010-06-01

Skull base metastases are challenging situations because they often involve critical structures such as cranial nerves. We evaluated the role of stereotactic radiotherapy (SRT) which can give high doses to the tumors sparing normal structures. We treated 11 cases of skull base metastases from other visceral carcinomas. They had neurological symptoms due to cranial nerve involvement including optic nerve (3 patients), oculomotor (3), trigeminal (6), abducens (1), facial (4), acoustic (1), and lower cranial nerves (1). The interval between the onset of cranial nerve symptoms and Novalis SRT was 1 week to 7 months. Eleven tumors of 8-112 ml in volume were treated by Novalis SRT with 30-50 Gy in 10-14 fractions. The tumors were covered by 90-95% isodose. Imaging and clinical follow-up has been obtained in all 11 patients for 5-36 months after SRT. Seven patients among 11 died from primary carcinoma or other visceral metastases 9-36 months after Novalis SRT. All 11 metastatic tumors were locally controlled until the end of the follow-up time or patient death, though retreatment for re-growth was done in 1 patient. In 10 of 11 patients, cranial nerve deficits were improved completely or partially. In some patients, the cranial nerve symptoms were relieved even during the period of fractionated SRT. Novalis SRT is thought to be safe and effective treatment for skull base metastases with involvement of cranial nerves and it may improve cranial nerve symptoms quickly.

Growth of the skull in young children in Baotou, China.

PubMed

Hou, Hai-dong; Liu, Ming; Gong, Ke-rui; Shao, Guo; Zhang, Chun-Yang

2014-09-01

There are some controversies about the optimal time to perform skull repair in very young Chinese children because of the rapid skull growth in this stage of life. The purpose of this current study is to describe the characteristics of skull growth and to discuss the optimal time for skull repair in young Chinese children with skull defects. A total of 112 children born in the First Affiliated Hospital of Baotou Medical College were measured for six consecutive years starting in 2006. Cranial length (CL, linear distance between the eyebrows to the pillow tuberosity), cranial width (CW, double-sided linear distance of connection of external auditory canal), ear over the top line (EOTL), the eyebrows-the posterior tuberosity line (EPTL), and head circumference (HC) were measured to describe the skull growth. The most rapid period of skull growth occurs during the first year of life. The second and third most rapid periods are the second and third years, respectively. Then, the skull growth slowed and the values of the skull growth index of 6-year-old children were close to those of adults. Children 0-1 years old should not receive skull repair due to their rapid skull growth. The indexes of children 3 years old or older were close to those of the adult; therefore, 3 years old or older may receive skull repair.

Expanded Endoscopic Endonasal Approaches to Skull Base Meningiomas

PubMed Central

Prosser, J. Drew; Vender, John R.; Alleyne, Cargill H.; Solares, C. Arturo

2012-01-01

Anterior cranial base meningiomas have traditionally been addressed via frontal or frontolateral approaches. However, with the advances in endoscopic endonasal treatment of pituitary lesions, the transphenoidal approach is being expanded to address lesions of the petrous ridge, anterior clinoid, clivus, sella, parasellar region, tuberculum, planum, olfactory groove, and crista galli regions. The expanded endoscopic endonasal approach (EEEA) has the advantage of limiting brain retraction and resultant brain edema, as well as minimizing manipulation of neural structures. Herein, we describe the techniques of transclival, transphenoidal, transplanum, and transcribiform resections of anterior skull base meningiomas. Selected cases are presented. PMID:23730542

Effectiveness and Safety of Spot Scanning Proton Radiation Therapy for Chordomas and Chondrosarcomas of the Skull Base: First Long-Term Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ares, Carmen, E-mail: carmen.ares@psi.c; Hug, Eugen B.; Lomax, Antony J.

2009-11-15

Purpose: To evaluate effectiveness and safety of spot-scanning-based proton radiotherapy (PT) in skull-base chordomas and chondrosarcomas. Methods and Materials: Between October 1998 and November 2005, 64 patients with skull-base chordomas (n = 42) and chondrosarcomas (n = 22) were treated at Paul Scherrer Institute with PT using spot-scanning technique. Median total dose for chordomas was 73.5 Gy(RBE) and 68.4 Gy(RBE) for chondrosarcomas at 1.8-2.0 Gy(RBE) dose per fraction. Local control (LC), disease specific survival (DSS), and overall survival (OS) rates were calculated. Toxicity was assessed according to CTCAE, v. 3.0. Results: Mean follow-up period was 38 months (range, 14-92 months).more » Five patients with chordoma and one patient with chondrosarcoma experienced local recurrence. Actuarial 5-year LC rates were 81% for chordomas and 94% for chondrosarcomas. Brainstem compression at the time of PT (p = 0.007) and gross tumor volume >25 mL (p = 0.03) were associated with lower LC rates. Five years rates of DSS and OS were 81% and 62% for chordomas and 100% and 91% for chondrosarcomas, respectively. High-grade late toxicity consisted of one patient with Grade 3 and one patient with Grade 4 unilateral optic neuropathy, and two patients with Grade 3 central nervous system necrosis. No patient experienced brainstem toxicity. Actuarial 5-year freedom from high-grade toxicity was 94%. Conclusions: Our data indicate safety and efficacy of spot-scanning based PT for skull-base chordomas and chondrosarcomas. With target definition, dose prescription and normal organ tolerance levels similar to passive-scattering based PT series, complication-free, tumor control and survival rates are at present comparable.« less

A dual resolution measurement based Monte Carlo simulation technique for detailed dose analysis of small volume organs in the skull base region

NASA Astrophysics Data System (ADS)

Yeh, Chi-Yuan; Tung, Chuan-Jung; Chao, Tsi-Chain; Lin, Mu-Han; Lee, Chung-Chi

2014-11-01

The purpose of this study was to examine dose distribution of a skull base tumor and surrounding critical structures in response to high dose intensity-modulated radiosurgery (IMRS) with Monte Carlo (MC) simulation using a dual resolution sandwich phantom. The measurement-based Monte Carlo (MBMC) method (Lin et al., 2009) was adopted for the study. The major components of the MBMC technique involve (1) the BEAMnrc code for beam transport through the treatment head of a Varian 21EX linear accelerator, (2) the DOSXYZnrc code for patient dose simulation and (3) an EPID-measured efficiency map which describes non-uniform fluence distribution of the IMRS treatment beam. For the simulated case, five isocentric 6 MV photon beams were designed to deliver a total dose of 1200 cGy in two fractions to the skull base tumor. A sandwich phantom for the MBMC simulation was created based on the patient's CT scan of a skull base tumor [gross tumor volume (GTV)=8.4 cm3] near the right 8th cranial nerve. The phantom, consisted of a 1.2-cm thick skull base region, had a voxel resolution of 0.05×0.05×0.1 cm3 and was sandwiched in between 0.05×0.05×0.3 cm3 slices of a head phantom. A coarser 0.2×0.2×0.3 cm3 single resolution (SR) phantom was also created for comparison with the sandwich phantom. A particle history of 3×108 for each beam was used for simulations of both the SR and the sandwich phantoms to achieve a statistical uncertainty of <2%. Our study showed that the planning target volume (PTV) receiving at least 95% of the prescribed dose (VPTV95) was 96.9%, 96.7% and 99.9% for the TPS, SR, and sandwich phantom, respectively. The maximum and mean doses to large organs such as the PTV, brain stem, and parotid gland for the TPS, SR and sandwich MC simulations did not show any significant difference; however, significant dose differences were observed for very small structures like the right 8th cranial nerve, right cochlea, right malleus and right semicircular canal. Dose volume histogram (DVH) analyses revealed much smoother DVH curves for the dual resolution sandwich phantom when compared to the SR phantom. In conclusion, MBMC simulations using a dual resolution sandwich phantom improved simulation spatial resolution for skull base IMRS therapy. More detailed dose analyses for small critical structures can be made available to help in clinical judgment.

Cystic angiomatosis of the craniocervical junction associated with Chiari I malformation: case report and review of the literature.

PubMed

Pavanello, Marco; Piatelli, Gianluca; Ravegnani, Marcello; Consales, Alessandro; Rossi, Andrea; Nozza, Paolo; Milanaccio, Claudia; Carbone, Marco; Cama, Armando

2007-06-01

Cystic angiomatosis of the skull and spine is an exceptionally rare, benign vascular lesion. Both the vertebral bones and the skull may be affected. Diagnosis and treatment of this disease is multidisciplinary. Histological examination is ultimately required to make a diagnosis. When the craniocervical junction is involved, the site of biopsy should be carefully selected so as to reduce procedure-related morbidity, including cerebrospinal fluid leakage and spinal deformity. We present a case report of a 4-year-old boy with cystic angiomatosis of the skull base and upper cervical spine associated with a Chiari I malformation and provide a review of the pertinent literature.

Leg length, skull circumference, and the prevalence of dementia in low and middle income countries; a 10/66 population-based cross sectional survey

PubMed Central

Prince, Martin; Acosta, Daisy; Dangour, Alan D; Uauy, Ricardo; Guerra, Mariella; Huang, Yueqin; Jacob, KS; Llibre Rodriguez, Juan J.; Salas, Aquiles; Sosa, Ana Luisa; Williams, Joseph D.; Acosta, Isaac; Albanese, Emiliano; Dewey, Michael E.; Ferri, Cleusa P.; Stewart, Robert; Gaona, Ciro; Jotheeswaran, AT.; Senthil Kumar, P; Li, Shuran; Llibre Guerra, Juan C.; Rodriguez, Diana; Rodriguez, Guillermina

2017-01-01

Background Adult leg length is influenced by nutrition in the first few years of life. Adult head circumference is an indicator of brain growth. There is a limited literature linking short legs and small skulls to an increased risk for cognitive impairment and dementia in late life. Methods One phase cross-sectional surveys of all over 65 year old residents (n=14,960) in 11 catchment areas in China, India, Cuba, Dominican Republic, Venezuela, Mexico and Peru. The cross-culturally validated 10/66 dementia diagnosis, and a sociodemographic and risk factor questionnaire were administered to all participants, and anthropometric measures taken. Poisson regression was used to calculate prevalence ratios for the effect of leg length and skull circumference upon 10/66 Dementia, controlling for age, gender, education and family history of dementia. Results The pooled meta-analysed fixed effect for leg length (highest vs. lowest quarter) was 0.82 (95% CI, 0.68-0.98) and for skull circumference 0.75 (95% CI, 0.63-0.89). While point estimates varied between sites, the proportion of the variability attributable to heterogeneity between studies as opposed to sampling error (I2) was 0% for leg length and 22% for skull circumference. The effects were independent and not mediated by family history of dementia. The effect of skull circumference was not modified by educational level or gender, and the effect of leg length was not modified by gender. Conclusions Since leg length and skull circumference are said to remain stable throughout adulthood into old age, reverse causality is an unlikely explanation for the findings. Early life nutritional programming, as well as neurodevelopment may protect against neurodegeneration. PMID:20701817

Does skull shape mediate the relationship between objective features and subjective impressions about the face?

PubMed

Marečková, Klára; Chakravarty, M Mallar; Huang, Mei; Lawrence, Claire; Leonard, Gabriel; Perron, Michel; Pike, Bruce G; Richer, Louis; Veillette, Suzanne; Pausova, Zdenka; Paus, Tomáš

2013-10-01

In our previous work, we described facial features associated with a successful recognition of the sex of the face (Marečková et al., 2011). These features were based on landmarks placed on the surface of faces reconstructed from magnetic resonance (MR) images; their position was therefore influenced by both soft tissue (fat and muscle) and bone structure of the skull. Here, we ask whether bone structure has dissociable influences on observers' identification of the sex of the face. To answer this question, we used a novel method of studying skull morphology using MR images and explored the relationship between skull features, facial features, and sex recognition in a large sample of adolescents (n=876; including 475 adolescents from our original report). To determine whether skull features mediate the relationship between facial features and identification accuracy, we performed mediation analysis using bootstrapping. In males, skull features mediated fully the relationship between facial features and sex judgments. In females, the skull mediated this relationship only after adjusting facial features for the amount of body fat (estimated with bioimpedance). While body fat had a very slight positive influence on correct sex judgments about male faces, there was a robust negative influence of body fat on the correct sex judgments about female faces. Overall, these results suggest that craniofacial bone structure is essential for correct sex judgments about a male face. In females, body fat influences negatively the accuracy of sex judgments, and craniofacial bone structure alone cannot explain the relationship between facial features and identification of a face as female. Copyright © 2013 Elsevier Inc. All rights reserved.

Transposition of the paraclival carotid artery: a novel concept of self-retaining vascular retraction during endoscopic endonasal skull base surgery technical report.

PubMed

Freeman, Jacob L; Sampath, Raghuram; Casey, Michael A; Quattlebaum, Steven Craig; Ramakrishnan, Vijay R; Youssef, A Samy

2016-08-01

Fixed retraction of the internal carotid artery (ICA) has previously been described for use during transcranial microscopic surgery. We report the novel use of a self-retaining microvascular retractor for static repositioning and protection of the ICA during expanded endonasal endoscopic approaches to the paramedian skull base. The transmaxillary, transpterygoid approach was performed in five cadaver heads (ten sides). The self-retaining microvascular retractor was used to laterally reposition the pterygopalatine fossa contents during exposure of the pterygoid base/plates and the paraclival ICA to expose the petrous apex. Maximum ICA retraction distance was measured in the x-axis for all ten sides. The average horizontal distance of ICA retraction measured at the mid-paraclival segment for all ten sides was 4.75 mm. In all cases, the carotid artery was repositioned without injury to the vessel or disruption of the surrounding neurovascular structures. Static repositioning of the ICA and other delicate neurovascular structures was effectively performed during endonasal, endoscopic cadaveric surgery of the skull base and has potential merits in live patients.

Neural network modeling for surgical decisions on traumatic brain injury patients.

PubMed

Li, Y C; Liu, L; Chiu, W T; Jian, W S

2000-01-01

Computerized medical decision support systems have been a major research topic in recent years. Intelligent computer programs were implemented to aid physicians and other medical professionals in making difficult medical decisions. This report compares three different mathematical models for building a traumatic brain injury (TBI) medical decision support system (MDSS). These models were developed based on a large TBI patient database. This MDSS accepts a set of patient data such as the types of skull fracture, Glasgow Coma Scale (GCS), episode of convulsion and return the chance that a neurosurgeon would recommend an open-skull surgery for this patient. The three mathematical models described in this report including a logistic regression model, a multi-layer perceptron (MLP) neural network and a radial-basis-function (RBF) neural network. From the 12,640 patients selected from the database. A randomly drawn 9480 cases were used as the training group to develop/train our models. The other 3160 cases were in the validation group which we used to evaluate the performance of these models. We used sensitivity, specificity, areas under receiver-operating characteristics (ROC) curve and calibration curves as the indicator of how accurate these models are in predicting a neurosurgeon's decision on open-skull surgery. The results showed that, assuming equal importance of sensitivity and specificity, the logistic regression model had a (sensitivity, specificity) of (73%, 68%), compared to (80%, 80%) from the RBF model and (88%, 80%) from the MLP model. The resultant areas under ROC curve for logistic regression, RBF and MLP neural networks are 0.761, 0.880 and 0.897, respectively (P < 0.05). Among these models, the logistic regression has noticeably poorer calibration. This study demonstrated the feasibility of applying neural networks as the mechanism for TBI decision support systems based on clinical databases. The results also suggest that neural networks may be a better solution for complex, non-linear medical decision support systems than conventional statistical techniques such as logistic regression.

[Extended endoscopic endonasal posterior (transclival) approach to tumors of the clival region and ventral posterior cranial fossa. Part 1. Topographic and anatomical features of the clivus and adjacent structures].

PubMed

Shkarubo, A N; Koval', K V; Dobrovol'skiy, G F; Shkarubo, M A; Karnaukhov, V V; Kadashev, B A; Andreev, D N; Chernov, I V; Gadzhieva, O A; Aleshkina, O Yu; Anisimova, E A; Kalinin, P L; Kutin, M A; Fomichev, D V; Sharipov, O I; Ismailov, D B; Selivanov, E S

to describe the main topographic and anatomical features of the clival region and its adjacent structures for improvement and optimization of the extended endoscopic endonasal posterior (transclival) approach for resection of tumors of the clival region and ventral posterior cranial fossa. We performed a craniometric study of 125 human skulls and a topographic anatomical study of heads of 25 cadavers, the arterial and venous bed of which was stained with colored silicone (the staining technique was developed by the authors) to visualize bed features and individual variability. Currently, we have clinical material from more than 120 surgical patients with various skull base tumors of the clival region and ventral posterior cranial fossa (chordomas, pituitary adenomas, meningiomas, cholesteatomas, etc.) who were operated on using the endoscopic transclival approach. We present the main anatomical landmarks and parameters of some anatomical structures that are required for performing the endoscopic endonasal posterior approach. The anatomical landmarks, such as the intradural openings of the abducens and glossopharyngeal nerves, may be used to arbitrarily divide the clival region into the superior, middle, and inferior thirds. The anatomical landmarks important for the surgeon, which are detected during a topographic anatomical study of the skull base, facilitate identification of the boundaries between the different clival portions and the C1 segments of the internal carotid arteries. The superior, middle, and inferior transclival approaches provide an access to the ventral surface of the upper, middle, and lower neurovascular complexes in the posterior cranial fossa. The endoscopic transclival approach may be used to access midline tumors of the posterior cranial fossa. The approach is an alternative to transcranial approaches in surgical treatment of clival region lesions. This approach provides results comparable (and sometimes better) to those of the transcranial and transfacial approaches.

Device and method for skull-melting depth measurement

DOEpatents

Lauf, R.J.; Heestand, R.L.

1993-02-09

A method of skull-melting comprises the steps of: (a) providing a vessel adapted for a skull-melting process, the vessel having an interior, an underside, and an orifice connecting the interior and the underside; (b) disposing a waveguide in the orifice so that the waveguide protrudes sufficiently into the interior to interact with the skull-melting process; (c) providing a signal energy transducer in signal communication with the waveguide; (d) introducing into the vessel a molten working material; (e) carrying out the skull-melting process so that a solidified skull of the working material is formed, the skull and the vessel having an interface therebetween, the skull becoming fused to the waveguide so the signal energy can be transmitted through the waveguide and the skull without interference from the interface; (f) activating the signal energy transducer so that a signal is propagated through the waveguide; and, (g) controlling at least one variable of the skull-melting process utilizing feedback information derived from the propagated signal energy.

Device and method for skull-melting depth measurement

DOEpatents

Lauf, Robert J.; Heestand, Richard L.

1993-01-01

A method of skull-melting comprises the steps of: a. providing a vessel adapted for a skull-melting process, the vessel having an interior, an underside, and an orifice in connecting the interior and the underside; b. disposing a waveguide in the orifice so that the waveguide protrudes sufficiently into the interior to interact with the skull-melting process; c. providing a signal energy transducer in signal communication with the waveguide; d. introducing into the vessel a molten working material; e. carrying out the skull-melting process so that a solidified skull of the working material is formed, the skull and the vessel having an interface therebetween, the skull becoming fused to the waveguide so the signal energy can be transmitted through the waveguide and the skull without interference from the interface; f. activating the signal energy transducer so that a signal is propagated through the waveguide; and, g. controlling at least one variable of the skull-melting process utilizing feedback information derived from the propagated signal energy.

Risk factors for cerebrospinal fluid leak in pediatric patients undergoing endoscopic endonasal skull base surgery.

PubMed

Stapleton, Amanda L; Tyler-Kabara, Elizabeth C; Gardner, Paul A; Snyderman, Carl H; Wang, Eric W

2017-02-01

To determine the risk factors associated with cerebrospinal fluid (CSF) leak following endoscopic endonasal surgery (EES) for pediatric skull base lesions. Retrospective chart review of pediatric patients (ages 1 month to 18 years) treated for skull base lesions with EES from 1999 to 2014. Five pathologies were reviewed: craniopharyngioma, clival chordoma, pituitary adenoma, pituitary carcinoma, and Rathke's cleft cyst. Fisher's exact tests were used to evaluate the different factors to determine which had a statistically higher risk of leading to a post-operative CSF leak. 55 pediatric patients were identified who underwent 70 EES's for tumor resection. Of the 70 surgeries, 47 surgeries had intraoperative CSF leaks that were repaired at the time of surgery. 11 of 47 (23%) surgeries had post-operative CSF leaks that required secondary operative repair. Clival chordomas had the highest CSF leak rate at 36%. There was no statistical difference in leak rate based on the type of reconstruction, although 28% of cases that used a vascularized flap had a post-operative leak, whereas only 9% of those cases not using a vascularized flap had a leak. Post-operative hydrocephalus and perioperative use of a lumbar drain were not significant risk factors. Pediatric patients with an intra-operative CSF leak during EES of the skull base have a high rate of post-operative CSF leaks. Clival chordomas appear to be a particularly high-risk group. The use of vascularized flaps and perioperative lumbar drains did not statistically decrease the rate of post-operative CSF leak. Copyright © 2017 Elsevier B.V. All rights reserved.

Early harvesting of the vascularized pedicled nasoseptal flap during endoscopic skull base surgery.

PubMed

Eloy, Jean Anderson; Patel, Amit A; Shukla, Pratik A; Choudhry, Osamah J; Liu, James K

2013-01-01

The vascularized pedicled nasoseptal flap (PNSF) represents a successful option for reconstruction of large skull base defects after expanded endoscopic endonasal approaches (EEA). This vascularized flap can be harvested early or late in the operation depending on the anticipation of high-flow CSF leaks. Each harvesting technique (early vs. late) is associated with different advantages and disadvantages. In this study, we evaluate our experience with early harvesting of the PNSF for repair of large skull base defects after EEA. A retrospective review was performed at a tertiary care medical center on patients who underwent early PNSF harvesting during reconstruction of intraoperative high-flow CSF leaks after EEA between December 2008 and March 2012. Demographic data, repair materials, surgical approach, and incidence of PNSF usage were collected. Eighty-seven patients meeting the inclusion criteria were identified. In 86 procedures (98.9%), the PNSF harvested at the beginning of the operation was used. In 1 case (1.1%), the PNSF was not used because a high-flow intraoperative CSF leak was not encountered. This patient had recurrence of intradural disease 8months later, and the previously elevated PNSF was subsequent used after tumor resection. Based on our data, a high-flow CSF leak and need for a PNSF can be accurately anticipated in patients undergoing EEA for skull base lesions. Because of the advantages of early harvesting of the PNSF and the high preoperative predictive value of CSF leak anticipations, this technique represents a feasible harvesting practice for EEA surgeries. Copyright © 2013 Elsevier Inc. All rights reserved.

The pioneering contribution of italian surgeons to skull base surgery.

PubMed

Priola, Stefano M; Raffa, Giovanni; Abbritti, Rosaria V; Merlo, Lucia; Angileri, Filippo F; La Torre, Domenico; Conti, Alfredo; Germanò, Antonino; Tomasello, Francesco

2014-01-01

The origin of neurosurgery as a modern, successful, and separate branch of surgery could be dated back to the end of the 19th century. The most important development of surgery occurred in Europe, particularly in Italy, where there was a unique environment, allowing brilliant open-minded surgeons to perform, with success, neurosurgical operations. Neurosurgery began at the skull base. In everyday practice, we still pay tribute to early Italian neuroanatomists and pioneer neurosurgeons who represented a starting point in a new, obscure, and still challenging field of medicine and surgery during their times. In this paper, we report at a glance the contributions of Tito Vanzetti from Padua (1809-1888), for his operation on a destructive skull base cyst that had, indeed, an intracranial expansion; of Davide Giordano (1864-1954) from Venice, who described the first transnasal approach to the pituitary gland; and, most importantly, of Francesco Durante from Messina (1844-1934), who was the first surgeon in the history of neurosurgery to successfully remove a cranial base meningioma. They carried out the first detailed reported surgical excision of intracranial lesions at the skull base, diagnosed only through clinical signs; used many of the advances of the 19th century; and conceived and performed new operative strategies and approaches. Their operations were radical enough to allow the patient to survive the surgery and, in the case of Durante, for the first time, to obtain more than 12 years of good survival at a time when a tumor of this type would have been fatal. Copyright © 2014 Elsevier Inc. All rights reserved.

Immediate, but Not Delayed, Microsurgical Skull Reconstruction Exacerbates Brain Damage in Experimental Traumatic Brain Injury Model

PubMed Central

Lau, Tsz; Kaneko, Yuji; van Loveren, Harry; Borlongan, Cesario V.

2012-01-01

Moderate to severe traumatic brain injury (TBI) often results in malformations to the skull. Aesthetic surgical maneuvers may offer normalized skull structure, but inconsistent surgical closure of the skull area accompanies TBI. We examined whether wound closure by replacement of skull flap and bone wax would allow aesthetic reconstruction of the TBI-induced skull damage without causing any detrimental effects to the cortical tissue. Adult male Sprague-Dawley rats were subjected to TBI using the controlled cortical impact (CCI) injury model. Immediately after the TBI surgery, animals were randomly assigned to skull flap replacement with or without bone wax or no bone reconstruction, then were euthanized at five days post-TBI for pathological analyses. The skull reconstruction provided normalized gross bone architecture, but 2,3,5-triphenyltetrazolium chloride and hematoxylin and eosin staining results revealed larger cortical damage in these animals compared to those that underwent no surgical maneuver at all. Brain swelling accompanied TBI, especially the severe model, that could have relieved the intracranial pressure in those animals with no skull reconstruction. In contrast, the immediate skull reconstruction produced an upregulation of the edema marker aquaporin-4 staining, which likely prevented the therapeutic benefits of brain swelling and resulted in larger cortical infarcts. Interestingly, TBI animals introduced to a delay in skull reconstruction (i.e., 2 days post-TBI) showed significantly reduced edema and infarcts compared to those exposed to immediate skull reconstruction. That immediate, but not delayed, skull reconstruction may exacerbate TBI-induced cortical tissue damage warrants a careful consideration of aesthetic repair of the skull in TBI. PMID:22438975

A testbed for optimizing electrodes embedded in the skull or in artificial skull replacement pieces used after injury

PubMed Central

Jiang, JingLe; Marathe, Amar R.; Keene, Jennifer C.; Taylor, Dawn M.

2016-01-01

Background Custom-fitted skull replacement pieces are often used after a head injury or surgery to replace damaged bone. Chronic brain recordings are beneficial after injury/surgery for monitoring brain health and seizure development. Embedding electrodes directly in these artificial skull replacement pieces would be a novel, low-risk way to perform chronic brain monitoring in these patients. Similarly, embedding electrodes directly in healthy skull would be a viable minimally-invasive option for many other neuroscience and neurotechnology applications requiring chronic brain recordings. New Method We demonstrate a preclinical testbed that can be used for refining electrode designs embedded in artificial skull replacement pieces or for embedding directly into the skull itself. Options are explored to increase the surface area of the contacts without increasing recording contact diameter to maximize recording resolution. Results Embedding electrodes in real or artificial skull allows one to lower electrode impedance without increasing the recording contact diameter by making use of conductive channels that extend into the skull. The higher density of small contacts embedded in the artificial skull in this testbed enables one to optimize electrode spacing for use in real bone. Comparison with Existing Methods For brain monitoring applications, skull-embedded electrodes fill a gap between electroencephalograms recorded on the scalp surface and the more invasive epidural or subdural electrode sheets. Conclusions Embedding electrodes into the skull or in skull replacement pieces may provide a safe, convenient, minimally-invasive alternative for chronic brain monitoring. The manufacturing methods described here will facilitate further testing of skull-embedded electrodes in animal models. PMID:27979758

A testbed for optimizing electrodes embedded in the skull or in artificial skull replacement pieces used after injury.

PubMed

Jiang, JingLe; Marathe, Amar R; Keene, Jennifer C; Taylor, Dawn M

2017-02-01

Custom-fitted skull replacement pieces are often used after a head injury or surgery to replace damaged bone. Chronic brain recordings are beneficial after injury/surgery for monitoring brain health and seizure development. Embedding electrodes directly in these artificial skull replacement pieces would be a novel, low-risk way to perform chronic brain monitoring in these patients. Similarly, embedding electrodes directly in healthy skull would be a viable minimally-invasive option for many other neuroscience and neurotechnology applications requiring chronic brain recordings. We demonstrate a preclinical testbed that can be used for refining electrode designs embedded in artificial skull replacement pieces or for embedding directly into the skull itself. Options are explored to increase the surface area of the contacts without increasing recording contact diameter to maximize recording resolution. Embedding electrodes in real or artificial skull allows one to lower electrode impedance without increasing the recording contact diameter by making use of conductive channels that extend into the skull. The higher density of small contacts embedded in the artificial skull in this testbed enables one to optimize electrode spacing for use in real bone. For brain monitoring applications, skull-embedded electrodes fill a gap between electroencephalograms recorded on the scalp surface and the more invasive epidural or subdural electrode sheets. Embedding electrodes into the skull or in skull replacement pieces may provide a safe, convenient, minimally-invasive alternative for chronic brain monitoring. The manufacturing methods described here will facilitate further testing of skull-embedded electrodes in animal models. Published by Elsevier B.V.

True lemurs…true species - species delimitation using multiple data sources in the brown lemur complex

PubMed Central

2013-01-01

Background Species are the fundamental units in evolutionary biology. However, defining them as evolutionary independent lineages requires integration of several independent sources of information in order to develop robust hypotheses for taxonomic classification. Here, we exemplarily propose an integrative framework for species delimitation in the “brown lemur complex” (BLC) of Madagascar, which consists of seven allopatric populations of the genus Eulemur (Primates: Lemuridae), which were sampled extensively across northern, eastern and western Madagascar to collect fecal samples for DNA extraction as well as recordings of vocalizations. Our data base was extended by including museum specimens with reliable identification and locality information for skull shape and pelage color analysis. Results Between-group analyses of principal components revealed significant heterogeneity in skull shape, pelage color variation and loud calls across all seven populations. Furthermore, post-hoc statistical tests between pairs of populations revealed considerable discordance among different data sets for different dyads. Despite a high degree of incomplete lineage sorting among nuclear loci, significant exclusive ancestry was found for all populations, except for E. cinereiceps, based on one mitochondrial and three nuclear genetic loci. Conclusions Using several independent lines of evidence, our results confirm the species status of the members of the BLC under the general lineage concept of species. More generally, the present analyses demonstrate the importance and value of integrating different kinds of data in delimiting recently evolved radiations. PMID:24159931

3D shape recovery of a newborn skull using thin-plate splines.

PubMed

Lapeer, R J; Prager, R W

2000-01-01

The objective of this paper is to construct a mesh-model of a newborn skull for finite element analysis to study its deformation when subjected to the forces present during labour. The current state of medical imaging technology has reached a level which allows accurate visualisation and shape recovery of biological organs and body-parts. However, a sufficiently large set of medical images cannot always be obtained, often because of practical or ethical reasons, and the requirement to recover the shape of the biological object of interest has to be met by other means. Such is the case for a newborn skull. A method to recover the three-dimensional (3D) shape from (minimum) two orthogonal atlas images of the object of interest and a homologous object is described. This method is based on matching landmarks and curves on the orthogonal images of the object of interest with corresponding landmarks and curves on the homologous or 'master'-object which is fully defined in 3D space. On the basis of this set of corresponding landmarks, a thin-plate spline function can be derived to warp from the 'master'-object space to the 'slave'-object space. This method is applied to recover the 3D shape of a newborn skull. Images from orthogonal view-planes are obtained from an atlas. The homologous object is an adult skull, obtained from CT-images made available by the Visible Human Project. After shape recovery, a mesh-model of the newborn skull is generated.

Implant-retained skull prosthesis to cover a large defect of the hairy skull resulting from treatment of a basal cell carcinoma: A clinical report.

PubMed

Hoekstra, Jitske; Vissink, Arjan; Raghoebar, Gerry M; Visser, Anita

2017-05-01

Skin carcinoma, particularly basal cell carcinoma, and its treatment can result in large defects of the hairy skull. A 53-year-old man is described who was surgically treated for a large basal cell carcinoma invading the skin and underlying tissue at the top of the hairy skull. Treatment consisted of resecting the tumor and external part of the skull bone. To protect the brain and to cover the defect of the hairy skull, an acrylic resin skull prosthesis with hair was designed to mask the defect. The skull prosthesis was retained on 8 extraoral implants placed at the margins of the defect in the skull bone. The patient was satisfied with the treatment outcome. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Skull removal in MR images using a modified artificial bee colony optimization algorithm.

PubMed

Taherdangkoo, Mohammad

2014-01-01

Removal of the skull from brain Magnetic Resonance (MR) images is an important preprocessing step required for other image analysis techniques such as brain tissue segmentation. In this paper, we propose a new algorithm based on the Artificial Bee Colony (ABC) optimization algorithm to remove the skull region from brain MR images. We modify the ABC algorithm using a different strategy for initializing the coordinates of scout bees and their direction of search. Moreover, we impose an additional constraint to the ABC algorithm to avoid the creation of discontinuous regions. We found that our algorithm successfully removed all bony skull from a sample of de-identified MR brain images acquired from different model scanners. The obtained results of the proposed algorithm compared with those of previously introduced well known optimization algorithms such as Particle Swarm Optimization (PSO) and Ant Colony Optimization (ACO) demonstrate the superior results and computational performance of our algorithm, suggesting its potential for clinical applications.

Study on the criteria for assessing skull-face correspondence in craniofacial superimposition.

PubMed

Ibáñez, Oscar; Valsecchi, Andrea; Cavalli, Fabio; Huete, María Isabel; Campomanes-Alvarez, Blanca Rosario; Campomanes-Alvarez, Carmen; Vicente, Ricardo; Navega, David; Ross, Ann; Wilkinson, Caroline; Jankauskas, Rimantas; Imaizumi, Kazuhiko; Hardiman, Rita; Jayaprakash, Paul Thomas; Ruiz, Elena; Molinero, Francisco; Lestón, Patricio; Veselovskaya, Elizaveta; Abramov, Alexey; Steyn, Maryna; Cardoso, Joao; Humpire, Daniel; Lusnig, Luca; Gibelli, Daniele; Mazzarelli, Debora; Gaudio, Daniel; Collini, Federica; Damas, Sergio

2016-11-01

Craniofacial superimposition has the potential to be used as an identification method when other traditional biological techniques are not applicable due to insufficient quality or absence of ante-mortem and post-mortem data. Despite having been used in many countries as a method of inclusion and exclusion for over a century it lacks standards. Thus, the purpose of this research is to provide forensic practitioners with standard criteria for analysing skull-face relationships. Thirty-seven experts from 16 different institutions participated in this study, which consisted of evaluating 65 criteria for assessing skull-face anatomical consistency on a sample of 24 different skull-face superimpositions. An unbiased statistical analysis established the most objective and discriminative criteria. Results did not show strong associations, however, important insights to address lack of standards were provided. In addition, a novel methodology for understanding and standardizing identification methods based on the observation of morphological patterns has been proposed. Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.

Skull ontogeny: developmental patterns of fishes conserved across major tetrapod clades.

PubMed

Schoch, Rainer R

2006-01-01

In vertebrates, the ontogeny of the bony skull forms a particularly complex part of embryonic development. Although this area used to be restricted to neontology, recent discoveries of fossil ontogenies provide an additional source of data. One of the most detailed ossification sequences is known from Permo-Carboniferous amphibians, the branchiosaurids. These temnospondyls form a near-perfect link between the piscine osteichthyans and the various clades of extant tetrapods, retaining a full complement of dermal bones in the skull. For the first time, the broader evolutionary significance of these event sequences is analyzed, focusing on the identification of sequence heterochronies. A set of 120 event pairs was analyzed by event pair cracking, which helped identify active movers. A cladistic analysis of the event pair data was also carried out, highlighting some shared patterns between widely divergent clades of tetrapods. The analyses revealed an unexpected degree of similarity between the widely divergent taxa. Most interesting is the apparently modular composition of the cranial sequence: five clusters of bones were discovered in each of which the elements form in the same time window: (1) jaw bones, (2) marginal palatal elements, (3) circumorbital bones, (4) skull roof elements, and (5) neurocranial ossifications. In the studied taxa, these "modules" have in most cases been shifted fore and back on the trajectory relative to the Amia sequence, but did not disintegrate. Such "modules" might indicate a high degree of evolutionary limitation (constraint).

A computed tomography-based spatial normalization for the analysis of [18F] fluorodeoxyglucose positron emission tomography of the brain.

PubMed

Cho, Hanna; Kim, Jin Su; Choi, Jae Yong; Ryu, Young Hoon; Lyoo, Chul Hyoung

2014-01-01

We developed a new computed tomography (CT)-based spatial normalization method and CT template to demonstrate its usefulness in spatial normalization of positron emission tomography (PET) images with [(18)F] fluorodeoxyglucose (FDG) PET studies in healthy controls. Seventy healthy controls underwent brain CT scan (120 KeV, 180 mAs, and 3 mm of thickness) and [(18)F] FDG PET scans using a PET/CT scanner. T1-weighted magnetic resonance (MR) images were acquired for all subjects. By averaging skull-stripped and spatially-normalized MR and CT images, we created skull-stripped MR and CT templates for spatial normalization. The skull-stripped MR and CT images were spatially normalized to each structural template. PET images were spatially normalized by applying spatial transformation parameters to normalize skull-stripped MR and CT images. A conventional perfusion PET template was used for PET-based spatial normalization. Regional standardized uptake values (SUV) measured by overlaying the template volume of interest (VOI) were compared to those measured with FreeSurfer-generated VOI (FSVOI). All three spatial normalization methods underestimated regional SUV values by 0.3-20% compared to those measured with FSVOI. The CT-based method showed slightly greater underestimation bias. Regional SUV values derived from all three spatial normalization methods were correlated significantly (p < 0.0001) with those measured with FSVOI. CT-based spatial normalization may be an alternative method for structure-based spatial normalization of [(18)F] FDG PET when MR imaging is unavailable. Therefore, it is useful for PET/CT studies with various radiotracers whose uptake is expected to be limited to specific brain regions or highly variable within study population.

Aberrant growth of maxillary canine teeth in male babirusa (genus Babyrousa).

PubMed

Macdonald, Alastair A

2018-04-01

A worldwide survey of babirusa skulls curated in museum and private collections located 431 that were from adult males and had retained at least one maxillary canine tooth. Eighty-three of these skulls were identified as exhibiting aberrant maxillary canine tooth growth. Twenty-four of the skulls represented babirusa from Buru and the Sula Islands, and forty-five skulls represented babirusa from Sulawesi and the Togian Islands. The remaining series of fourteen babirusa skulls originally came from zoo animals. Fifteen skulls showed anomalous alveolar and tooth rotation in a median plane. Twenty-nine skulls had maxillary canine teeth that did not grow symmetrically towards the median plane of the cranium. Fourteen skulls showed evidence that the tips of one or both maxillary canine teeth had eroded the nasal bones. Twenty-one skulls had maxillary canine teeth that had eroded the frontal bones. The teeth of two skulls had eroded a parietal bone. One skull had two maxillary canines arising from an adjacent pair of alveoli on the left side of the cranium. Three skulls exhibited alveoli with no formed maxillary canine teeth in them. Analysis suggested that approximately 12% of the adult male babirusa in the wild experience erosion of the cranial bony tissues as a result of maxillary canine tooth growth. There was no skeletal evidence that maxillary canine teeth penetrate the eye. Crown Copyright © 2018. Published by Elsevier Masson SAS. All rights reserved.

Patterns of postnatal ontogeny of the skull and lower jaw of snakes as revealed by micro-CT scan data and three-dimensional geometric morphometrics.

PubMed

Palci, Alessandro; Lee, Michael S Y; Hutchinson, Mark N

2016-12-01

We compared the head skeleton (skull and lower jaw) of juvenile and adult specimens of five snake species [Anilios (=Ramphotyphlops) bicolor, Cylindrophis ruffus, Aspidites melanocephalus, Acrochordus arafurae, and Notechis scutatus] and two lizard outgroups (Ctenophorus decresii, Varanus gilleni). All major ontogenetic changes observed were documented both qualitatively and quantitatively. Qualitative comparisons were based on high-resolution micro-CT scanning of the specimens, and detailed quantitative analyses were performed using three-dimensional geometric morphometrics. Two sets of landmarks were used, one for accurate representation of the intraspecific transformations of each skull and jaw configuration, and the other for comparison between taxa. Our results document the ontogenetic elaboration of crests and processes for muscle attachment (especially for cervical and adductor muscles); negative allometry in the braincase of all taxa; approximately isometric growth of the snout of all taxa except Varanus and Anilios (positively allometric); and positive allometry in the quadrates of the macrostomatan snakes Aspidites, Acrochordus and Notechis, but also, surprisingly, in the iguanian lizard Ctenophorus. Ontogenetic trajectories from principal component analysis provide evidence for paedomorphosis in Anilios and peramorphosis in Acrochordus. Some primitive (lizard-like) features are described for the first time in the juvenile Cylindrophis. Two distinct developmental trajectories for the achievement of the macrostomatan (large-gaped) condition in adult snakes are documented, driven either by positive allometry of supratemporal and quadrate (in pythons), or of quadrate alone (in sampled caenophidians); this is consistent with hypothesised homoplasy in this adaptive complex. Certain traits (e.g. shape of coronoid process, marginal tooth counts) are more stable throughout postnatal ontogeny than others (e.g. basisphenoid keel), with implications for their reliability as phylogenetic characters. © 2016 Anatomical Society.

Conveying practical clinical skills with the help of teaching associates-a randomised trial with focus on the long term learning retention.

PubMed

Hoefer, Sebastian H; Sterz, Jasmina; Bender, Bernd; Stefanescu, Maria-Christina; Theis, Marius; Walcher, Felix; Sader, Robert; Ruesseler, Miriam

2017-03-28

Ensuring that all medical students achieve adequate clinical skills remains a challenge, yet the correct performance of clinical skills is critical for all fields of medicine. This study analyzes the influence of receiving feedback by teaching associates in the context of achieving and maintaining a level of expertise in complex head and skull examination. All third year students at a German university who completed the obligatory surgical skills lab training and surgical clerkship participated in this study. The students were randomized into two groups. lessons by an instructor and peer-based practical skills training. Intervention group: training by teaching associates who are examined as simulation patients and provided direct feedback on student performance. Their competency in short- and long-term competence (directly after intervention and at 4 months after the training) of head and skull examination was measured. Statistical analyses were performed using SPSS Statistics version 19 (IBM, Armonk, USA). Parametric and non-parametric test methods were applied. As a measurement of correlation, Pearson correlations and correlations via Kendall's-Tau-b were calculated and Cohen's d effect size was calculated. A total of 181 students were included (90 intervention, 91 control). Out of those 181 students 81 agreed to be videotaped (32 in the control group and 49 in the TA group) and examined at time point 1. At both time points, the intervention group performed the examination significantly better (time point 1, p = <.001; time point 2 (rater 1 p = .009, rater 2 p = .015), than the control group. The effect size (Cohens d) was up to 1.422. The use of teaching associates for teaching complex practical skills is effective for short- and long-term retention. We anticipate the method could be easily translated to nearly every patient-based clinical skill, particularly with regards to a competence-based education of future doctors.

21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures. (b...

21 CFR 882.4750 - Skull punch.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Skull punch. 882.4750 Section 882.4750 Food and... NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4750 Skull punch. (a) Identification. A skull punch is a device used to punch holes through a patient's skull to allow fixation of cranioplasty plates or...

21 CFR 882.4030 - Skull plate anvil.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Skull plate anvil. 882.4030 Section 882.4030 Food... DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4030 Skull plate anvil. (a) Identification. A skull plate anvil is a device used to form alterable skull plates in the proper shape to fit...

Contrast enhancement in EIT imaging of the brain.

PubMed

Nissinen, A; Kaipio, J P; Vauhkonen, M; Kolehmainen, V

2016-01-01

We consider electrical impedance tomography (EIT) imaging of the brain. The brain is surrounded by the poorly conducting skull which has low conductivity compared to the brain. The skull layer causes a partial shielding effect which leads to weak sensitivity for the imaging of the brain tissue. In this paper we propose an approach based on the Bayesian approximation error approach, to enhance the contrast in brain imaging. With this approach, both the (uninteresting) geometry and the conductivity of the skull are embedded in the approximation error statistics, which leads to a computationally efficient algorithm that is able to detect features such as internal haemorrhage with significantly increased sensitivity and specificity. We evaluate the approach with simulations and phantom data.

Infant skull fracture (image)

MedlinePlus

Skull fractures may occur with head injuries. Although the skull is both tough and resilient and provides excellent ... or blow can result in fracture of the skull and may be accompanied by injury to the ...

Paleoneurosurgical aspects of Proto-Bulgarian artificial skull deformations.

PubMed

Enchev, Yavor; Nedelkov, Grigoriy; Atanassova-Timeva, Nadezhda; Jordanov, Jordan

2010-12-01

Paleoneurosurgery represents a comparatively new developing direction of neurosurgery dealing with archaeological skull and spine finds and studying their neurosurgical aspects. Artificial skull deformation, as a bone artifact, naturally has been one of the main paleoneurosurgical research topics. Traditionally, the relevant neurosurgical literature has analyzed in detail the intentional skull deformations in South America's tribes. However, little is known about the artificial skull deformations of the Proto-Bulgarians, and what information exists is mostly due to anthropological studies. The Proto-Bulgarians originated from Central Asia, and distributed their skull deformation ritual on the Balkan Peninsula by their migration and domination. Proto-Bulgarian artificial skull deformation was an erect or oblique form of the anular type, and was achieved by 1 or 2 pressure bandages that were tightened around a newborn's head for a sufficiently long period. The intentional skull deformation in Proto-Bulgarians was not associated with neurological deficits and/or mental retardation. No indirect signs of chronic elevated intracranial pressure were found on the 3D CT reconstruction of the artificially deformed skulls.

Diffuse skull base/cervical fusion syndromes in two siblings with spondylocostal dysostosis syndrome: analysis via three dimensional computed tomography scanning.

PubMed

Al Kaissi, Ali; Ben Chehida, Farid; Ben Ghachem, Maher; Klaushofer, Klaus; Grill, Franz

2008-06-01

A study on a pair of male sibs to reach for the etiological understanding of unusual skull base/spine maldevelopment. Previously, radiographs alone were used to formulate this diagnosis. Here, three-dimensional computed tomography (3D CT) studies further clarified the typical diagnostic findings associated with spondylocostal dysostosis (SCD). Interestingly, patients with SCD are at increased risk for diffuse skull base/cervical fusion syndromes and can result in severe neurologic deficits associated with any degree of trauma. Classically SCD is defined as a skeletal dysplasia with clinical and radiologic manifestations, consisting of short neck and trunk, nonprogressive scoliosis and abnormalities of vertebral segmentation and of the ribs. Radiograms have been adopted as the only modality for the classification and prognostication of patients with SCD. Detailed clinical and radiographic examinations were undertaken with emphasis on the significance of the 3D CT scanning. We observed extensive fusion of the clivus with the cervical/entire spine, resulting in a remarkable solid, immobile, and fixed bony ankylosis of extremely serious outcome. Patients with spondylcostal dysostosis are predisposed to develop extensive skull-base-cervical spine fusion. The latter might lead to the development of a solid, immobile, and fixed bony ankylosis. In children/adults trivial injuries and/or high-energy trauma can lead to serious intracranial and spinal cord injury. Comprehensive orthopedic and neurosurgeons management must follow the recognition of these anomalies. To the best of our knowledge, no previous CT studies of the spine have been published in patients with SCD.

A clinical pilot study of a modular video-CT augmentation system for image-guided skull base surgery

NASA Astrophysics Data System (ADS)

Liu, Wen P.; Mirota, Daniel J.; Uneri, Ali; Otake, Yoshito; Hager, Gregory; Reh, Douglas D.; Ishii, Masaru; Gallia, Gary L.; Siewerdsen, Jeffrey H.

2012-02-01

Augmentation of endoscopic video with preoperative or intraoperative image data [e.g., planning data and/or anatomical segmentations defined in computed tomography (CT) and magnetic resonance (MR)], can improve navigation, spatial orientation, confidence, and tissue resection in skull base surgery, especially with respect to critical neurovascular structures that may be difficult to visualize in the video scene. This paper presents the engineering and evaluation of a video augmentation system for endoscopic skull base surgery translated to use in a clinical study. Extension of previous research yielded a practical system with a modular design that can be applied to other endoscopic surgeries, including orthopedic, abdominal, and thoracic procedures. A clinical pilot study is underway to assess feasibility and benefit to surgical performance by overlaying CT or MR planning data in realtime, high-definition endoscopic video. Preoperative planning included segmentation of the carotid arteries, optic nerves, and surgical target volume (e.g., tumor). An automated camera calibration process was developed that demonstrates mean re-projection accuracy (0.7+/-0.3) pixels and mean target registration error of (2.3+/-1.5) mm. An IRB-approved clinical study involving fifteen patients undergoing skull base tumor surgery is underway in which each surgery includes the experimental video-CT system deployed in parallel to the standard-of-care (unaugmented) video display. Questionnaires distributed to one neurosurgeon and two otolaryngologists are used to assess primary outcome measures regarding the benefit to surgical confidence in localizing critical structures and targets by means of video overlay during surgical approach, resection, and reconstruction.

The use of portable intraoperative computed tomography scanning for real-time image guidance: a pilot cadaver study.

PubMed

Das, Subinoy; Maeso, Patricia A; Figueroa, Ramon E; Senior, Brent A; Delgaudio, John M; Sillers, Michael J; Schlosser, Rod J; Kountakis, Stilianos E

2008-01-01

This study was performed to assess the feasibility of using intraoperative computed tomography (CT) to provide real-time updates to image guidance systems (IGSs) during surgery. The xCAT ENT portable intraoperative CT scanner (Xoran Technologies, Ann Arbor, MI) was used to acquire scans before, midway, and at the end of six cadaver dissections during the Southern States Rhinology Course, Augusta, GA, in October 2006. These scans were used to recalibrate three different IGSs used during the dissection. Time measurements were recorded and dosimetry was obtained from the cornea, sphenoid sinus (near the optic chiasm), and from the operative field during acquisition of the images. IGS accuracy was determined at the skull base and lamina papyracea. Surgeons were interviewed on benefits of real-time updates to the IGS after completion of dissections. The xCAT ENT scanner was compatible with all three IGS platforms. The average time to update the IGS was 13 minutes. Radiation doses to the cornea were 620 mrad per scan, and optic chiasm was 800 mrad/scan. The accuracy at the anterior skull base improved from 1.58 to 0.62 mm (p=0.026). The accuracy at the posterior skull base improved from 1.46 to 0.71 mm (p=0.014). The accuracy at the lamina was not significantly changed. Intraoperative portable CT scanning with real-time IGS updates is feasible and likely would add little additional time. Accuracy is improved at the skull base. Prospective studies on actual patients are warranted.

Required Reading: The Most Impactful Articles in Endoscopic Endonasal Skull Base Surgery.

PubMed

Zhang, Michael; Singh, Harminder; Almodovar-Mercado, Gustavo J; Anand, Vijay K; Schwartz, Theodore H

2016-08-01

Endoscopic endonasal skull base surgery has become widely accepted in neurosurgery and otolaryngology over the last 15 years. However, there has yet to be a formal curation of the most impactful articles for an introductory curriculum to its technical evolution. The Science Citation Index Expanded was used to generate a citation rank list (October 2015) on articles relevant to endoscopic skull base surgery. The top 35 cited articles overall, as well as the top 15 since 2009, were identified. Journal, year, author, study population, article format, and level of evidence were compiled. Additional surgeon experts were polled and made recommendations for significant contributions to the literature. The top 35 publications ranged from 98 to 467 citations and were published in 10 different journals. Four articles had more than 250 citations. A period of frequent contribution occurred between 2005 and 2009, when 21/35 reports were published. 18/35 articles were case series, and 13/35 were technical reports. There were 11/35 articles focused primarily on pituitary surgery and 10/35 on extrasellar lesions. The top 15 articles since 2009 had 8/15 articles focused on extrasellar lesions. Polled surgeons consistently identified the most prominently cited articles, and their recommendations drew attention to cerebrospinal fluid leak as well as extrasellar management. Identification of the most cited works within endoscopic endonasal skull base surgery shows greater anatomic access and safety over the last 2 decades. These articles can serve as an educational tool for novices or midlevel practitioners wishing to obtain a greater understanding of the field. Copyright © 2016 Elsevier Inc. All rights reserved.

Robust Skull-Stripping Segmentation Based on Irrational Mask for Magnetic Resonance Brain Images.

PubMed

Moldovanu, Simona; Moraru, Luminița; Biswas, Anjan

2015-12-01

This paper proposes a new method for simple, efficient, and robust removal of the non-brain tissues in MR images based on an irrational mask for filtration within a binary morphological operation framework. The proposed skull-stripping segmentation is based on two irrational 3 × 3 and 5 × 5 masks, having the sum of its weights equal to the transcendental number π value provided by the Gregory-Leibniz infinite series. It allows maintaining a lower rate of useful pixel loss. The proposed method has been tested in two ways. First, it has been validated as a binary method by comparing and contrasting with Otsu's, Sauvola's, Niblack's, and Bernsen's binary methods. Secondly, its accuracy has been verified against three state-of-the-art skull-stripping methods: the graph cuts method, the method based on Chan-Vese active contour model, and the simplex mesh and histogram analysis skull stripping. The performance of the proposed method has been assessed using the Dice scores, overlap and extra fractions, and sensitivity and specificity as statistical methods. The gold standard has been provided by two neurologist experts. The proposed method has been tested and validated on 26 image series which contain 216 images from two publicly available databases: the Whole Brain Atlas and the Internet Brain Segmentation Repository that include a highly variable sample population (with reference to age, sex, healthy/diseased). The approach performs accurately on both standardized databases. The main advantage of the proposed method is its robustness and speed.

[Neurophysiological identification of the cranial nerves in endoscopic endonasal surgery of skull base tumors].

PubMed

Shkarubo, A N; Ogurtsova, A A; Moshchev, D A; Lubnin, A Yu; Andreev, D N; Koval', K V; Chernov, I V

2016-01-01

Intraoperative identification of the cranial nerves is a useful technique in removal of skull base tumors through the endoscopic endonasal approach. Searching through the scientific literature found one pilot study on the use of triggered electromyography (t-EMG) for identification of the VIth nerve in endonasal endoscopic surgery of skull base tumors (D. San-Juan, et al, 2014). The study objective was to prevent iatrogenic injuries to the cranial nerves without reducing the completeness of tumor tissue resection. In 2014, 5 patients were operated on using the endoscopic endonasal approach. Surgeries were performed for large skull base chordomas (2 cases) and trigeminal nerve neurinomas located in the cavernous sinus (3). Intraoperatively, identification of the cranial nerves was performed by triggered electromyography using a bipolar electrode (except 1 case of chordoma where a monopolar electrode was used). Evaluation of the functional activity of the cranial nerves was carried out both preoperatively and postoperatively. Tumor resection was total in 4 out of 5 cases and subtotal (chordoma) in 1 case. Intraoperatively, the IIIrd (2 patients), Vth (2), and VIth (4) cranial nerves were identified. No deterioration in the function of the intraoperatively identified nerves was observed in the postoperative period. In one case, no responses from the VIth nerve on the right (in the cavernous sinus region) were intraoperatively obtained, and deep paresis (up to plegia) of the nerve-innervated muscles developed in the postoperative period. The nerve function was not impaired before surgery. The t-EMG technique is promising and requires further research.

Combined treatment of advanced stages of recurrent skin cancer of the head.

PubMed

Pompucci, Angelo; Rea, Giancarla; Farallo, Eugenio; Salgarello, Marzia; Campanella, Antonino; Fernandez, Eduardo

2004-04-01

The authors investigated whether skull base resection and primary free-flap reconstruction in a single-stage surgery is oncologically effective for treating advanced stages of recurrent skin cancer (RSC) of the head. Eighteen consecutive patients were surgically treated. Twelve of them underwent an anterolateral skull base resection, which was performed using a pterional craniotomy combined with an orbitozygomatic osteotomy. Six patients underwent a posterolateral skull base resection, which was performed using an asterional craniotomy combined with a retrolabyrinthine petrosectomy. The wide postoperative defects were covered with muscular or myocutaneous free flaps. The main factor influencing survival was the extent of the resection: patients with no or minimal residual disease showed a statistically significant longer survival time than those with consistent residual disease. Basal cell carcinoma had a better prognosis than squamous cell carcinoma. A trend toward improved survival was observed in patients classified as T4M0 with negative lymph nodes (N0), but this trend was not statistically significant. Adjuvant radiotherapy significantly influenced both survival time and the rate of local recurrence. The surgical morbidity rate was 27.8%; there were two transient cerebrospinal fluid leaks and three seventh cranial nerve injuries. Late complications included radionecrosis in one patient and skin erosion requiring a second surgery in another patient. No deaths occurred during a 30-day postoperative period. Advances in skull base surgery and free-flap reconstruction allowed the authors to treat patients with advanced-stage RSC of the head in a rather satisfactory manner. Only when it is impossible to achieve no or minimal residual disease should aggressive treatment be considered.

Skull x-ray

MedlinePlus

X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... Chernecky CC, Berger BJ. Radiography of skull, chest, and cervical spine - diagnostic. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. ...

Surgical approaches to complex vascular lesions: the use of virtual reality and stereoscopic analysis as a tool for resident and student education.

PubMed

Agarwal, Nitin; Schmitt, Paul J; Sukul, Vishad; Prestigiacomo, Charles J

2012-08-01

Virtual reality training for complex tasks has been shown to be of benefit in fields involving highly technical and demanding skill sets. The use of a stereoscopic three-dimensional (3D) virtual reality environment to teach a patient-specific analysis of the microsurgical treatment modalities of a complex basilar aneurysm is presented. Three different surgical approaches were evaluated in a virtual environment and then compared to elucidate the best surgical approach. These approaches were assessed with regard to the line-of-sight, skull base anatomy and visualisation of the relevant anatomy at the level of the basilar artery and surrounding structures. Overall, the stereoscopic 3D virtual reality environment with fusion of multimodality imaging affords an excellent teaching tool for residents and medical students to learn surgical approaches to vascular lesions. Future studies will assess the educational benefits of this modality and develop a series of metrics for student assessments.

A large, switchable optical clearing skull window for cerebrovascular imaging

PubMed Central

Zhang, Chao; Feng, Wei; Zhao, Yanjie; Yu, Tingting; Li, Pengcheng; Xu, Tonghui; Luo, Qingming; Zhu, Dan

2018-01-01

Rationale: Intravital optical imaging is a significant method for investigating cerebrovascular structure and function. However, its imaging contrast and depth are limited by the turbid skull. Tissue optical clearing has a great potential for solving this problem. Our goal was to develop a transparent skull window, without performing a craniotomy, for use in assessing cerebrovascular structure and function. Methods: Skull optical clearing agents were topically applied to the skulls of mice to create a transparent window within 15 min. The clearing efficacy, repeatability, and safety of the skull window were then investigated. Results: Imaging through the optical clearing skull window enhanced both the contrast and the depth of intravital imaging. The skull window could be used on 2-8-month-old mice and could be expanded from regional to bi-hemispheric. In addition, the window could be repeatedly established without inducing observable inflammation and metabolic toxicity. Conclusion: We successfully developed an easy-to-handle, large, switchable, and safe optical clearing skull window. Combined with various optical imaging techniques, cerebrovascular structure and function can be observed through this optical clearing skull window. Thus, it has the potential for use in basic research on the physiopathologic processes of cortical vessels. PMID:29774069

Augmented real-time navigation with critical structure proximity alerts for endoscopic skull base surgery.

PubMed

Dixon, Benjamin J; Daly, Michael J; Chan, Harley; Vescan, Allan; Witterick, Ian J; Irish, Jonathan C

2014-04-01

Image-guided surgery (IGS) systems are frequently utilized during cranial base surgery to aid in orientation and facilitate targeted surgery. We wished to assess the performance of our recently developed localized intraoperative virtual endoscopy (LIVE)-IGS prototype in a preclinical setting prior to deployment in the operating room. This system combines real-time ablative instrument tracking, critical structure proximity alerts, three-dimensional virtual endoscopic views, and intraoperative cone-beam computed tomographic image updates. Randomized-controlled trial plus qualitative analysis. Skull base procedures were performed on 14 cadaver specimens by seven fellowship-trained skull base surgeons. Each subject performed two endoscopic transclival approaches; one with LIVE-IGS and one using a conventional IGS system in random order. National Aeronautics and Space Administration Task Load Index (NASA-TLX) scores were documented for each dissection, and a semistructured interview was recorded for qualitative assessment. The NASA-TLX scores for mental demand, effort, and frustration were significantly reduced with the LIVE-IGS system in comparison to conventional navigation (P < .05). The system interface was judged to be intuitive and most useful when there was a combination of high spatial demand, reduced or absent surface landmarks, and proximity to critical structures. The development of auditory icons for proximity alerts during the trial better informed the surgeon while limiting distraction. The LIVE-IGS system provided accurate, intuitive, and dynamic feedback to the operating surgeon. Further refinements to proximity alerts and visualization settings will enhance orientation while limiting distraction. The system is currently being deployed in a prospective clinical trial in skull base surgery. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Blunt forehead trauma and optic canal involvement: finite element analysis of anterior skull base and orbit on causes of vision impairment.

PubMed

Huempfner-Hierl, Heike; Bohne, Alexander; Wollny, Gert; Sterker, Ina; Hierl, Thomas

2015-10-01

Clinical studies report on vision impairment after blunt frontal head trauma. A possible cause is damage to the optic nerve bundle within the optic canal due to microfractures of the anterior skull base leading to indirect traumatic optic neuropathy. A finite element study simulating impact forces on the paramedian forehead in different grades was initiated. The set-up consisted of a high-resolution skull model with about 740 000 elements, a blunt impactor and was solved in a transient time-dependent simulation. Individual bone material parameters were calculated for each volume element to increase realism. Results showed stress propagation from the frontal impact towards the optic foramen and the chiasm even at low-force fist-like impacts. Higher impacts produced stress patterns corresponding to typical fracture patterns of the anterior skull base including the optic canal. Transient simulation discerned two stress peaks equalling oscillation. It can be concluded that even comparatively low stresses and oscillation in the optic foramen may cause micro damage undiscerned by CT or MRI explaining consecutive vision loss. Higher impacts lead to typical comminuted fractures, which may affect the integrity of the optic canal. Finite element simulation can be effectively used in studying head trauma and its clinical consequences. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Skull base osteomyelitis: current microbiology and management.

PubMed

Spielmann, P M; Yu, R; Neeff, M

2013-01-01

Skull base osteomyelitis typically presents in an immunocompromised patient with severe otalgia and otorrhoea. Pseudomonas aeruginosa is the commonest pathogenic micro-organism, and reports of resistance to fluoroquinolones are now emerging, complicating management. We reviewed our experience of this condition, and of the local pathogenic organisms. A retrospective review from 2004 to 2011 was performed. Patients were identified by their admission diagnostic code, and computerised records examined. Twenty patients were identified. A facial palsy was present in 12 patients (60 per cent). Blood cultures were uniformly negative, and culture of ear canal granulations was non-diagnostic in 71 per cent of cases. Pseudomonas aeruginosa was isolated in only 10 (50 per cent) cases; one strain was resistant to ciprofloxacin but all were sensitive to ceftazidime. Two cases of fungal skull base osteomyelitis were identified. The mortality rate was 15 per cent. The patients' treatment algorithm is presented. Our treatment algorithm reflects the need for multidisciplinary input, early microbial culture of specimens, appropriate imaging, and prolonged and systemic antimicrobial treatment. Resolution of infection must be confirmed by close follow up and imaging.

Thermal Model to Investigate the Temperature in Bone Grinding for Skull Base Neurosurgery

PubMed Central

Zhang, Lihui; Tai, Bruce L.; Wang, Guangjun; Zhang, Kuibang; Sullivan, Stephen; Shih, Albert J.

2013-01-01

This study develops a thermal model utilizing the inverse heat transfer method (IHTM) to investigate the bone grinding temperature created by a spherical diamond tool used for skull base neurosurgery. Bone grinding is a critical procedure in the expanded endonasal approach to remove the cranial bone and access to the skull base tumor via nasal corridor. The heat is generated during grinding and could damage the nerve or coagulate the blood in the carotid artery adjacent to the bone. The finite element analysis is adopted to investigate the grinding-induced bone temperature rise. The heat source distribution is defined by the thermal model, and the temperature distribution is solved using the IHTM with experimental inputs. Grinding experiments were conducted on a bovine cortical bone with embedded thermocouples. Results show significant temperature rise in bone grinding. Using 50°C as the threshold, the thermal injury can propagate about 3 mm in the traverse direction, and 3 mm below the ground surface under the dry grinding condition. The presented methodology demonstrated the capability of being a thermal analysis tool for bone grinding study. PMID:23683875

Extended maxillotomy for skull base access in contemporary management of chordomas: Rationale and technical aspect.

PubMed

Abdul Jalil, Muhammad Fahmi; Story, Rowan D; Rogers, Myron

2017-05-01

Minimally invasive approaches to the central skull base have been popularized over the last decade and have to a large extent displaced 'open' procedures. However, traditional skull base surgery still has its role especially when dealing with a large clival chordoma where maximal surgical resection is the principal goal to maximize patient survival. In this paper, we present a case of a 25year-old male patient with chordoma in the inferior clivus which was initially debulked via a transnasal endoscopic approach. He unfortunately had a large recurrence of tumor requiring re-do resection. With the aim to achieve maximal surgical resection, we then chose the technique of a transoral approach with Le Fort 1 maxillotomy and midline palatal split. Post-operative course for the patient was uneventful and post-operative MRI confirmed significant debulking of the clival lesion. The technique employed for the surgical procedure is presented here in detail as is our experience over two decades using this technique for tumors, inflammatory lesions and congenital abnormalities at the cranio-cervical junction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Visualizing Simulated Electrical Fields from Electroencephalography and Transcranial Electric Brain Stimulation: A Comparative Evaluation

PubMed Central

Eichelbaum, Sebastian; Dannhauer, Moritz; Hlawitschka, Mario; Brooks, Dana; Knösche, Thomas R.; Scheuermann, Gerik

2014-01-01

Electrical activity of neuronal populations is a crucial aspect of brain activity. This activity is not measured directly but recorded as electrical potential changes using head surface electrodes (electroencephalogram - EEG). Head surface electrodes can also be deployed to inject electrical currents in order to modulate brain activity (transcranial electric stimulation techniques) for therapeutic and neuroscientific purposes. In electroencephalography and noninvasive electric brain stimulation, electrical fields mediate between electrical signal sources and regions of interest (ROI). These fields can be very complicated in structure, and are influenced in a complex way by the conductivity profile of the human head. Visualization techniques play a central role to grasp the nature of those fields because such techniques allow for an effective conveyance of complex data and enable quick qualitative and quantitative assessments. The examination of volume conduction effects of particular head model parameterizations (e.g., skull thickness and layering), of brain anomalies (e.g., holes in the skull, tumors), location and extent of active brain areas (e.g., high concentrations of current densities) and around current injecting electrodes can be investigated using visualization. Here, we evaluate a number of widely used visualization techniques, based on either the potential distribution or on the current-flow. In particular, we focus on the extractability of quantitative and qualitative information from the obtained images, their effective integration of anatomical context information, and their interaction. We present illustrative examples from clinically and neuroscientifically relevant cases and discuss the pros and cons of the various visualization techniques. PMID:24821532

The evolution of the complex sensory and motor systems of the human brain

PubMed Central

Kaas, Jon H.

2008-01-01

Inferences about how the complex sensory and motor systems of the human brain evolved are based on the results of comparative studies of brain organization across a range of mammalian species, and evidence from the endocasts of fossil skulls of key extinct species. The endocasts of the skulls of early mammals indicate that they had small brains with little neocortex. Evidence from comparative studies of cortical organization from small-brained mammals of the six major branches of mammalian evolution supports the conclusion that the small neocortex of early mammals was divided into roughly 20–25 cortical areas, including primary and secondary sensory fields. In early primates, vision was the dominant sense, and cortical areas associated with vision in temporal and occipital cortex underwent a significant expansion. Comparative studies indicate that early primates had 10 or more visual areas, and somatosensory areas with expanded representations of the forepaw. Posterior parietal cortex was also expanded, with a caudal half dominated by visual inputs, and a rostral half dominated by somatosensory inputs with outputs to an array of seven or more motor and visuomotor areas of the frontal lobe. Somatosensory areas and posterior parietal cortex became further differentiated in early anthropoid primates. As larger brains evolved in early apes and in our hominin ancestors, the number of cortical areas increased to reach an estimated 200 or so in present day humans, and hemispheric specializations emerged. The large human brain grew primarily by increasing neuron number rather than increasing average neuron size. PMID:18331903

A Giant Pliosaurid Skull from the Late Jurassic of England

PubMed Central

Benson, Roger B. J.; Evans, Mark; Smith, Adam S.; Sassoon, Judyth; Moore-Faye, Scott; Ketchum, Hilary F.; Forrest, Richard

2013-01-01

Pliosaurids were a long-lived and cosmopolitan group of marine predators that spanned 110 million years and occupied the upper tiers of marine ecosystems from the Middle Jurassic until the early Late Cretaceous. A well-preserved giant pliosaurid skull from the Late Jurassic Kimmeridge Clay Formation of Dorset, United Kingdom, represents a new species, Pliosaurus kevani. This specimen is described in detail, and the taxonomy and systematics of Late Jurassic pliosaurids is revised. We name two additional new species, Pliosaurus carpenteri and Pliosaurus westburyensis, based on previously described relatively complete, well-preserved remains. Most or all Late Jurassic pliosaurids represent a globally distributed monophyletic group (the genus Pliosaurus, excluding ‘Pliosaurus’ andrewsi). Despite its high species diversity, and geographically widespread, temporally extensive occurrence, Pliosaurus shows relatively less morphological and ecological variation than is seen in earlier, multi-genus pliosaurid assemblages such as that of the Middle Jurassic Oxford Clay Formation. It also shows less ecological variation than the pliosaurid-like Cretaceous clade Polycotylidae. Species of Pliosaurus had robust skulls, large body sizes (with skull lengths of 1.7–2.1 metres), and trihedral or subtrihedral teeth suggesting macropredaceous habits. Our data support a trend of decreasing length of the mandibular symphysis through Late Jurassic time, as previously suggested. This may be correlated with increasing adaptation to feeding on large prey. Maximum body size of pliosaurids increased from their first appearance in the Early Jurassic until the Early Cretaceous (skull lengths up to 2360 mm). However, some reduction occurred before their final extinction in the early Late Cretaceous (skull lengths up to 1750 mm). PMID:23741520

Modelling and Experiment Based on a Navigation System for a Cranio-Maxillofacial Surgical Robot.

PubMed

Duan, Xingguang; Gao, Liang; Wang, Yonggui; Li, Jianxi; Li, Haoyuan; Guo, Yanjun

2018-01-01

In view of the characteristics of high risk and high accuracy in cranio-maxillofacial surgery, we present a novel surgical robot system that can be used in a variety of surgeries. The surgical robot system can assist surgeons in completing biopsy of skull base lesions, radiofrequency thermocoagulation of the trigeminal ganglion, and radioactive particle implantation of skull base malignant tumors. This paper focuses on modelling and experimental analyses of the robot system based on navigation technology. Firstly, the transformation relationship between the subsystems is realized based on the quaternion and the iterative closest point registration algorithm. The hand-eye coordination model based on optical navigation is established to control the end effector of the robot moving to the target position along the planning path. The closed-loop control method, "kinematics + optics" hybrid motion control method, is presented to improve the positioning accuracy of the system. Secondly, the accuracy of the system model was tested by model experiments. And the feasibility of the closed-loop control method was verified by comparing the positioning accuracy before and after the application of the method. Finally, the skull model experiments were performed to evaluate the function of the surgical robot system. The results validate its feasibility and are consistent with the preoperative surgical planning.

Modelling and Experiment Based on a Navigation System for a Cranio-Maxillofacial Surgical Robot

PubMed Central

Duan, Xingguang; Gao, Liang; Li, Jianxi; Li, Haoyuan; Guo, Yanjun

2018-01-01

In view of the characteristics of high risk and high accuracy in cranio-maxillofacial surgery, we present a novel surgical robot system that can be used in a variety of surgeries. The surgical robot system can assist surgeons in completing biopsy of skull base lesions, radiofrequency thermocoagulation of the trigeminal ganglion, and radioactive particle implantation of skull base malignant tumors. This paper focuses on modelling and experimental analyses of the robot system based on navigation technology. Firstly, the transformation relationship between the subsystems is realized based on the quaternion and the iterative closest point registration algorithm. The hand-eye coordination model based on optical navigation is established to control the end effector of the robot moving to the target position along the planning path. The closed-loop control method, “kinematics + optics” hybrid motion control method, is presented to improve the positioning accuracy of the system. Secondly, the accuracy of the system model was tested by model experiments. And the feasibility of the closed-loop control method was verified by comparing the positioning accuracy before and after the application of the method. Finally, the skull model experiments were performed to evaluate the function of the surgical robot system. The results validate its feasibility and are consistent with the preoperative surgical planning. PMID:29599948

Pubertal neurocranium growth in thymectomized rats.

PubMed

Rino, W; Teixeira, D

1979-01-01

Differences in neurocranium growth at puberty were studied in rats of both sexes thymectomized and sham-thymectomized at 2, 4, 6, 8, 10, 12 and 14 days of age and in controls of matched age and sex; skull length, width and height, and skull base length and face length were measured. The neurocranium of the thymectomized rats was significantly smaller than that of the sham-thymectomized and control rats of both sexes and in all age-groups.

Finite element modelling of squirrel, guinea pig and rat skulls: using geometric morphometrics to assess sensitivity.

PubMed

Cox, P G; Fagan, M J; Rayfield, E J; Jeffery, N

2011-12-01

Rodents are defined by a uniquely specialized dentition and a highly complex arrangement of jaw-closing muscles. Finite element analysis (FEA) is an ideal technique to investigate the biomechanical implications of these specializations, but it is essential to understand fully the degree of influence of the different input parameters of the FE model to have confidence in the model's predictions. This study evaluates the sensitivity of FE models of rodent crania to elastic properties of the materials, loading direction, and the location and orientation of the models' constraints. Three FE models were constructed of squirrel, guinea pig and rat skulls. Each was loaded to simulate biting on the incisors, and the first and the third molars, with the angle of the incisal bite varied over a range of 45°. The Young's moduli of the bone and teeth components were varied between limits defined by findings from our own and previously published tests of material properties. Geometric morphometrics (GMM) was used to analyse the resulting skull deformations. Bone stiffness was found to have the strongest influence on the results in all three rodents, followed by bite position, and then bite angle and muscle orientation. Tooth material properties were shown to have little effect on the deformation of the skull. The effect of bite position varied between species, with the mesiodistal position of the biting tooth being most important in squirrels and guinea pigs, whereas bilateral vs. unilateral biting had the greatest influence in rats. A GMM analysis of isolated incisor deformations showed that, for all rodents, bite angle is the most important parameter, followed by elastic properties of the tooth. The results here elucidate which input parameters are most important when defining the FE models, but also provide interesting glimpses of the biomechanical differences between the three skulls, which will be fully explored in future publications. © 2011 The Authors. Journal of Anatomy © 2011 Anatomical Society of Great Britain and Ireland.

Skull wounds linked with blunt trauma (hammer example). A report of two depressed skull fractures--elements of biomechanical explanation.

PubMed

Delannoy, Yann; Becart, Anne; Colard, Thomas; Delille, Rémi; Tournel, Gilles; Hedouin, Valéry; Gosset, Didier

2012-09-01

The lesions of the skull following perforating traumas can create complex fractures. The blunt traumas can, according to the swiftness and the shape of the object used, create a depressed fracture. The authors describe through two clinical cases the lesional characteristic of the blunt traumas, perforating the skull using a hammer. In both cases the cranial lesions were very typical: they were geometrical, square shaped, of the same size than the tool (head and tip of the hammer). On the outer table of the skull, the edges of the wounds were sharp and regular. On the inner table, the edges of the wounds were beveled and irregular. The bony penetration in the depressed fracture results from a rupture of the outer table of the bone under tension, in periphery, by the bend of the bone to the impact (outbending) and then, from the inner table with comminuted bony fragmentation. Breeding on the fractures of the size and the shape of the blunt objects used is inconstant and differs, that it is the objects of flat surface or wide in opposition to those of small surface area. Fractures morphologies depend on one hand on these extrinsic factors and on the other hand, of intrinsic factors (structure of the bone). To identify them, we had previously conducted experimental work on cranial bone samples. The bone was submitted to a device for three-point bending. This work had shown properties of thickness and stiffness of the various areas of the vault. Our cases are consistent with these results and illustrate the variability of bone lesions according to region and mode of use of blunt weapons. Many studies have identified criteria for identification of the weapons and the assistance of digital and biomechanical models will be an invaluable contribution with this aim in the future. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

[Criminal methods in archaeology--collaboration between Forensic Medicine Department, Pomeranian Medical University and the Archaeological Museum in Gdańsk].

PubMed

Kempińska-Podhorodecka, Agnieszka; Knap, Oktawian; Parafiniuk, Mirosław

2007-01-01

During excavation works carried in the Old Town by the Archaeological Museum in Gdańsk, human remains were found which date back to the turn of the 12th and 13th centuries. On the basis of Gdańsk townsmen's skulls, Forensic Medicine Department, Pomeranian Medical University (PAM) performed the skull based face reconstruction of 8 individuals. In this study, we wanted to present possibilities of using Gierasimow reconstruction method for museum goals. Reconstruction is an anthropological method which aims at reconstructing bony elements of a skull and head soft tissue. The most commonly employed modern way of reconstruction is Gierasimow's method which is based on the observation of soft tissue thickness and its dependence on the form and level of development of different skull areas. Standards for tissue thickness were elaborated for various points (along the profile and transverse sections); they were based on the examination of soft tissue thickness performed on the corpse (for each sex separately). Deviations from the standards result from racial affiliation, age, and the level of development of adequate skull areas. The research scheme includes determination of sex and age, and collection of the detailed craniometrical and cranioscopic data with comprehensive description of the features which can affect the appearance of soft parts. After relevant measurements are done, the muscles are modeled. During the following stage, soft tissue thickness is marked in particular points as stalks and ridges. Next they are joined together to achieve the final effect of reconstruction. From this moment, finishing works are continued by a sculptor in cooperation with an anthropologist. The results of research conducted by anthropologists, anatomists, morphologists, physicians and criminologists are of great importance and they convey both cognitive and practical meaning. Reconstructions appeal to human imagination, and for that reason they are also addressed to non-professional audience.

Functional Relationship between Skull Form and Feeding Mechanics in Sphenodon, and Implications for Diapsid Skull Development

PubMed Central

Curtis, Neil; Jones, Marc E. H.; Shi, Junfen; O'Higgins, Paul; Evans, Susan E.; Fagan, Michael J.

2011-01-01

The vertebrate skull evolved to protect the brain and sense organs, but with the appearance of jaws and associated forces there was a remarkable structural diversification. This suggests that the evolution of skull form may be linked to these forces, but an important area of debate is whether bone in the skull is minimised with respect to these forces, or whether skulls are mechanically “over-designed” and constrained by phylogeny and development. Mechanical analysis of diapsid reptile skulls could shed light on this longstanding debate. Compared to those of mammals, the skulls of many extant and extinct diapsids comprise an open framework of fenestrae (window-like openings) separated by bony struts (e.g., lizards, tuatara, dinosaurs and crocodiles), a cranial form thought to be strongly linked to feeding forces. We investigated this link by utilising the powerful engineering approach of multibody dynamics analysis to predict the physiological forces acting on the skull of the diapsid reptile Sphenodon. We then ran a series of structural finite element analyses to assess the correlation between bone strain and skull form. With comprehensive loading we found that the distribution of peak von Mises strains was particularly uniform throughout the skull, although specific regions were dominated by tensile strains while others were dominated by compressive strains. Our analyses suggest that the frame-like skulls of diapsid reptiles are probably optimally formed (mechanically ideal: sufficient strength with the minimal amount of bone) with respect to functional forces; they are efficient in terms of having minimal bone volume, minimal weight, and also minimal energy demands in maintenance. PMID:22216358

Mechanical Analysis of Feeding Behavior in the Extinct “Terror Bird” Andalgalornis steulleti (Gruiformes: Phorusrhacidae)

PubMed Central

Degrange, Federico J.; Tambussi, Claudia P.; Moreno, Karen; Witmer, Lawrence M.; Wroe, Stephen

2010-01-01

The South American phorusrhacid bird radiation comprised at least 18 species of small to gigantic terrestrial predators for which there are no close modern analogs. Here we perform functional analyses of the skull of the medium-sized (∼40 kg) patagornithine phorusrhacid Andalgalornis steulleti (upper Miocene–lower Pliocene, Andalgalá Formation, Catamarca, Argentina) to assess its mechanical performance in a comparative context. Based on computed tomographic (CT) scanning and morphological analysis, the skull of Andalgalornis steulleti is interpreted as showing features reflecting loss of intracranial immobility. Discrete anatomical attributes permitting such cranial kinesis are widespread phorusrhacids outgroups, but this is the first clear evidence of loss of cranial kinesis in a gruiform bird and may be among the best documented cases among all birds. This apomorphic loss is interpreted as an adaptation for enhanced craniofacial rigidity, particularly with regard to sagittal loading. We apply a Finite Element approach to a three-dimensional (3D) model of the skull. Based on regression analysis we estimate the bite force of Andalgalornis at the bill tip to be 133 N. Relative to results obtained from Finite Element Analysis of one of its closest living relatives (seriema) and a large predatory bird (eagle), the phorusrhacid's skull shows relatively high stress under lateral loadings, but low stress where force is applied dorsoventrally (sagittally) and in “pullback” simulations. Given the relative weakness of the skull mediolaterally, it seems unlikely that Andalgalornis engaged in potentially risky behaviors that involved subduing large, struggling prey with its beak. We suggest that it either consumed smaller prey that could be killed and consumed more safely (e.g., swallowed whole) or that it used multiple well-targeted sagittal strikes with the beak in a repetitive attack-and-retreat strategy. PMID:20805872

Facial image of Biblical Jews from Israel.

PubMed

Kobyliansky, E; Balueva, T; Veselovskaya, E; Arensburg, B

2008-06-01

The present report deals with reconstructing the facial shapes of ancient inhabitants of Israel based on their cranial remains. The skulls of a male from the Hellenistic period and a female from the Roman period have been reconstructed. They were restored using the most recently developed programs in anthropological facial reconstruction, especially that of the Institute of Ethnology and Anthropology of the Russian Academy of Sciences (Balueva & Veselovskaya 2004). The basic craniometrical measurements of the two skulls were measured according to Martin & Saller (1957) and compared to the data from three ancient populations of Israel described by Arensburg et al. (1980): that of the Hellenistic period dating from 332 to 37 B.C., that of the Roman period, from 37 B.C. to 324 C.E., and that of the Byzantine period that continued until the Arab conquest in 640 C.E. Most of this osteological material was excavated in the Jordan River and the Dead Sea areas. A sample from the XVIIth century Jews from Prague (Matiegka 1926) was also used for osteometrical comparisons. The present study will characterize not only the osteological morphology of the material, but also the facial appearance of ancient inhabitants of Israel. From an anthropometric point of view, the two skulls studied here definitely belong to the same sample from the Hellenistic, Roman, and Byzantine populations of Israel as well as from Jews from Prague. Based on its facial reconstruction, the male skull may belong to the large Mediterranean group that inhabited this area from historic to modern times. The female skull also exhibits all the Mediterranean features but, in addition, probably some equatorial (African) mixture manifested by the shape of the reconstructed nose and the facial prognatism.

Reflections on the mechanical structure of the base of the skull and on the face. Part 1: Classical theories, observed structures.

PubMed

Ferré, J C; Chevalier, C; Robert, R; Degrez, J; Le Cloarec, A Y; Legoux, R; Orio, E; Barbin, J Y

1989-01-01

Using thick sections of the base of the skull and face their mechanical structure is viewed from the engineering aspect and the anatomic solutions evolved are compared with those selected by Aerospatiale engineers for the concept and development of the Airbus. It is concluded that the anterior and middle cranial fossae, together with the face, constitute an inseparable mechanical assembly each of whose component units participate in the rigidity of the others. Since this mechanical assembly must provide maximal rigidity for minimal weight, this suggests that aeronautical solutions should throw much light on the detail of construction of the skull and face. Indeed, the rigidity and lightness of the latter are obtained by means of solutions familiar in aeronautics: the reliance on thin-shelled beams with a honeycomb filling, the diploe analogous to a preconstrained composite or sandwich structure, a system of frames, struts and stiffeners, and the use of fillets at the sites of junction of struts.

Numerical simulation of high intensity focused ultrasound temperature distribution for transcranial brain therapy

NASA Astrophysics Data System (ADS)

Zhang, Qian; Wang, Yizhe; Zhou, Wenzheng; Zhang, Ji; Jian, Xiqi

2017-03-01

To provide a reference for the HIFU clinical therapeutic planning, the temperature distribution and lesion volume are analyzed by the numerical simulation. The adopted numerical simulation is based on a transcranial ultrasound therapy model, including an 8 annular-element curved phased array transducer. The acoustic pressure and temperature elevation are calculated by using the approximation of Westervelt Formula and the Pennes Heat Transfer Equation. In addition, the Time Reversal theory and eliminating hot spot technique are combined to optimize the temperature distribution. With different input powers and exposure times, the lesion volume is evaluated based on temperature threshold theory. The lesion region could be restored at the expected location by the time reversal theory. Although the lesion volume reduces after eliminating the peak temperature in the skull and more input power and exposure time is required, the injury of normal tissue around skull could be reduced during the HIFU therapy. The prediction of thermal deposition in the skull and the lesion region could provide a reference for clinical therapeutic dose.

A paediatric case of bilateral mandibular condyle fracture presenting with bloody otorrhoea following trauma.

PubMed

Chan, Yat Chun; Au-Yeung, Kwan Leong

2017-04-22

A 7-year-old boy presented to the emergency department with bilateral bloody otorrhoea after falling from his scooter. Skull base fracture was suspected. CT showed no evidence of skull base fracture but bilateral mandibular condyle and external acoustic canals fractures. We report this case to illustrate a rare possibility of bilateral external acoustic canal fracture associated with condylar fracture in trauma patients presented with bloody otorrhoea. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Skull base lesions: extracranial origins.

PubMed

Mosier, Kristine M

2013-10-01

A number of extracranial anatomical sites, including the nasopharynx, paranasal sinuses, and masticator space, may give rise to lesions involving the skull base. Implicit in the nature of an invasive lesion, the majority of these lesions are malignant. Accordingly, for optimal patient outcomes and treatment planning, it is imperative to include a search pattern for extracranial sites and to assess accurately the character and extent of these diverse lesions. Of particular importance to radiologists are lesions arising from each extracranial site, the search patterns, and relevant information important to convey to the referring clinician. Copyright © 2013 Elsevier Inc. All rights reserved.

Degenerative Pannus Mimicking Clival Chordoma Resected via an Endoscopic Transnasal Approach.

PubMed

Khaldi, Ahmad; Griauzde, Julius; Duckworth, Edward A M

2011-05-01

Lesions of the lower clivus represent a technically challenging subset of skull base disease that requires careful treatment. A 75-year-old woman with tongue atrophy was referred for resection of a presumed clival chordoma. The lesion was resected via an endoscopic transnasal transclival approach with no complications. Pathology revealed only chronic inflammatory tissue consistent with a degenerative pannus. Degenerative pannus should be included in the differential diagnosis of lower clival extradural lesions. The endoscopic transnasal transclival corridor should be considered for resection of such lesions as an alternative to larger, more morbid, traditional skull base approaches.

Degenerative Pannus Mimicking Clival Chordoma Resected via an Endoscopic Transnasal Approach

PubMed Central

Khaldi, Ahmad; Griauzde, Julius; Duckworth, Edward A.M.

2011-01-01

Lesions of the lower clivus represent a technically challenging subset of skull base disease that requires careful treatment. A 75-year-old woman with tongue atrophy was referred for resection of a presumed clival chordoma. The lesion was resected via an endoscopic transnasal transclival approach with no complications. Pathology revealed only chronic inflammatory tissue consistent with a degenerative pannus. Degenerative pannus should be included in the differential diagnosis of lower clival extradural lesions. The endoscopic transnasal transclival corridor should be considered for resection of such lesions as an alternative to larger, more morbid, traditional skull base approaches. PMID:23984195

Endoscopic Removal of a Bullet in Rosenmuller Fossa: Case Report

PubMed Central

Burks, Joshua D.; Glenn, Chad A.; Conner, Andrew K.; Bonney, Phillip A.; Sanclement, Jose A.; Sughrue, Michael E.

2016-01-01

Fractures of the anterior skull base may occur in gunshot victims and can result in traumatic cerebrospinal fluid (CSF) leak. Less commonly, CSF leaks occur days or even weeks after the trauma occurred. Here, we present the case of a 21-year-old man with a delayed-onset, traumatic CSF leak secondary to a missile injury that left a bullet fragment in the Rosenmuller fossa. The patient was treated successfully with endoscopic, endonasal extraction of the bullet, and repair with a nasal septal flap. Foreign bodies lodged in Rosenmuller fossa can be successfully treated with endoscopic skull base surgery. PMID:27330924

Observation of skull-guided acoustic waves in a water-immersed murine skull using optoacoustic excitation

NASA Astrophysics Data System (ADS)

Estrada, Héctor; Rebling, Johannes; Razansky, Daniel

2017-02-01

The skull bone, a curved solid multilayered plate protecting the brain, constitutes a big challenge for the use of ultrasound-mediated techniques in neuroscience. Ultrasound waves incident from water or soft biological tissue are mostly reflected when impinging on the skull. To this end, skull properties have been characterized for both high-intensity focused ultrasound (HIFU) operating in the narrowband far-field regime and optoacoustic imaging applications. Yet, no study has been conducted to characterize the near-field of water immersed skulls. We used the thermoelastic effect with a 532 nm pulsed laser to trigger a wide range of broad-band ultrasound modes in a mouse skull. In order to capture the waves propagating in the near-field, a thin hydrophone was scanned in close proximity to the skull's surface. While Leaky pseudo-Lamb waves and grazing-angle bulk water waves are clearly visible in the spatio-temporal data, we were only able to identify skull-guided acoustic waves after dispersion analysis in the wavenumber-frequency space. The experimental data was found to be in a reasonable agreement with a flat multilayered plate model.

The Development of Skull Prosthesis Through Active Contour Model.

PubMed

Chen, Yi-Wen; Shih, Cheng-Ting; Cheng, Chen-Yang; Lin, Yu-Cheng

2017-09-09

Skull defects result in brain infection and inadequate brain protection and pose a general danger to patient health. To avoid these situations and prevent re-injury, a prosthesis must be constructed and grafted onto the deficient region. With the development of rapid customization through additive manufacturing and 3D printing technology, skull prostheses can be fabricated accurately and efficiently prior to cranioplasty. However, an unfitted skull prosthesis made with a metal implant can cause repeated infection, potentially necessitating secondary surgery. This paper presents a method of creating suitably geometric graphics of skull defects to be applied in skull repair through active contour models. These models can be adjusted in each computed tomography slice according to the graphic features, and the curves representing the skull defect can be modeled. The generated graphics can adequately mimic the natural curvature of the complete skull. This method will enable clinical surgeons to rapidly implant customized prostheses, which is of particular importance in emergency surgery. The findings of this research can help surgeons provide patients with skull defects with treatment of the highest quality.

Anatomical and Radiographic Study on the Skull and Mandible of the Common Opossum (Didelphis Marsupialis Linnaeus, 1758) in the Caribbean.

PubMed

Mohamed, Reda

2018-04-23

Common opossums ( Didelphis marsupialis ) are found throughout the Caribbean island of Trinidad and Tobago. The present work was conducted on 10 skulls and mandibles of the common opossum to describe the osteology and foramina of these skulls and mandibles grossly and radiographically. The information that is garnered can be used to detect, diagnose, and treat head affections, as well as for comparative studies with the skulls and mandibles of other similar species. The skulls and mandibles were prepared and cleaned using standard method. All of the characteristic features of various standards views of the skulls bones, including dorsal, lateral, caudal and midsagittal, and the lateral and caudal views of the mandibles as well as the foramina of the skulls and mandibles were described and discussed. Each skull was divided into long facial and short cranial regions. No supraorbital foramen was observed in the skulls. The tympanic bulla was absent while there was the tympanic process of the alisphenoid. The temporal process of the zygomatic bone, zygomatic process of maxilla, and zygomatic process of the squamosal bone formed the zygomatic arch. The dental formula was confirmed. The bones and foramina of the skull and mandible were similar to other marsupial species and were homologue to that of other mammals.

Magnetoencephalography signals are influenced by skull defects.

PubMed

Lau, S; Flemming, L; Haueisen, J

2014-08-01

Magnetoencephalography (MEG) signals had previously been hypothesized to have negligible sensitivity to skull defects. The objective is to experimentally investigate the influence of conducting skull defects on MEG and EEG signals. A miniaturized electric dipole was implanted in vivo into rabbit brains. Simultaneous recording using 64-channel EEG and 16-channel MEG was conducted, first above the intact skull and then above a skull defect. Skull defects were filled with agar gels, which had been formulated to have tissue-like homogeneous conductivities. The dipole was moved beneath the skull defects, and measurements were taken at regularly spaced points. The EEG signal amplitude increased 2-10 times, whereas the MEG signal amplitude reduced by as much as 20%. The EEG signal amplitude deviated more when the source was under the edge of the defect, whereas the MEG signal amplitude deviated more when the source was central under the defect. The change in MEG field-map topography (relative difference measure, RDM(∗)=0.15) was geometrically related to the skull defect edge. MEG and EEG signals can be substantially affected by skull defects. MEG source modeling requires realistic volume conductor head models that incorporate skull defects. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Coexistence of Wormian Bones With Metopism, and Vice Versa, in Adult Skulls.

PubMed

Cirpan, Sibel; Aksu, Funda; Mas, Nuket; Magden, Abdurrahman Orhan

2016-03-01

The aim of the study is to investigate coexistence of Wormian bones with metopism, and vice versa, in adult skulls. A total of 160 dry adult human skulls of unknown sex and ages were randomly selected from the Gross Anatomy Laboratory of Medical School of Dokuz Eylul University. The skulls were examined for presence of metopism, Wormian bones (WB), and coexistence of WBs with metopism and vice versa. Topographic distribution of the WBs was macroscopically evaluated within the skulls including metopism. The photographs were being taken with Canon 400B (55 mm objective). The frequency of metopism and WBs in 160 skulls is 7.50% (12/160) and 59.3% (95/160), respectively, P < 0.05 (). The incidence of coexistence of WBs with metopism was found as 11 of 12 skulls (91.66%), whereas the incidence of coexistence of metopism with WBs was found as 11 of 95 skulls (11.58%), P < 0.05 (). There were totally 23 sutures including WBs in 11 skulls, which had metopism (). The number (%) of metopic skulls for each specific suture including WBs were found as: 11 lamdoid sutures in 7/11 (63.63%) skulls, 4 lambda in 4/11 (36.36%) skulls, 2 asterion in 2/11 (18.18%) skulls, 1 squamous in 1/11 (9.09%) skull, 2 sagittal in 2/11 (18.18%) skulls, and 3 parieromsatoid sutures in 2/11 (18.18%) skulls (). The distribution of these 23 WBs in sutures of 11 skulls including metopisms is determined as follows: 11/23 (47.82%) WBs at lambdoid sutures [5/23 (21.74%) at the right lambdoid sutures and 6/23 (26.08%) at the left lambdoid sutures, and 4 pair of 11 WBs bilaterally located]; 4 (17.39%) WBs at lambda; 2/23 (8.69%) WBs at asterion [1/23 (4.34%) at the right asterion and 1/23 (4.34%) at the left asterion of 2 diverse skulls]; 2/23 (8.69%) WBs at sagittal sutures; 1/23 (4.34%) WBs at the left squamous suture; 3/23 (13.04%) WBs at parietomastoid sutures [2/23 (8.69%) at the right parietomastoid sutures and 1/23 (4.34%) at the left parietomastoid suture and 1 pair of them bilaterally located; , ].(Figure is included in full-text article.)(Table is included in full-text article.)(Table is included in full-text article.) : There was a significant difference in rates between coexistence of WBs with metopism (11/12, 91.66%) and coexistence of metopism with WBs (11/95, 11.58%). The factors leading to metopism may also lead to WBs, whereas that the factors leading to WBs may not lead to metopism.

Minimum-norm cortical source estimation in layered head models is robust against skull conductivity error☆☆☆

PubMed Central

Stenroos, Matti; Hauk, Olaf

2013-01-01

The conductivity profile of the head has a major effect on EEG signals, but unfortunately the conductivity for the most important compartment, skull, is only poorly known. In dipole modeling studies, errors in modeled skull conductivity have been considered to have a detrimental effect on EEG source estimation. However, as dipole models are very restrictive, those results cannot be generalized to other source estimation methods. In this work, we studied the sensitivity of EEG and combined MEG + EEG source estimation to errors in skull conductivity using a distributed source model and minimum-norm (MN) estimation. We used a MEG/EEG modeling set-up that reflected state-of-the-art practices of experimental research. Cortical surfaces were segmented and realistically-shaped three-layer anatomical head models were constructed, and forward models were built with Galerkin boundary element method while varying the skull conductivity. Lead-field topographies and MN spatial filter vectors were compared across conductivities, and the localization and spatial spread of the MN estimators were assessed using intuitive resolution metrics. The results showed that the MN estimator is robust against errors in skull conductivity: the conductivity had a moderate effect on amplitudes of lead fields and spatial filter vectors, but the effect on corresponding morphologies was small. The localization performance of the EEG or combined MEG + EEG MN estimator was only minimally affected by the conductivity error, while the spread of the estimate varied slightly. Thus, the uncertainty with respect to skull conductivity should not prevent researchers from applying minimum norm estimation to EEG or combined MEG + EEG data. Comparing our results to those obtained earlier with dipole models shows that general judgment on the performance of an imaging modality should not be based on analysis with one source estimation method only. PMID:23639259

Modelling human skull growth: a validated computational model

PubMed Central

Marghoub, Arsalan; Johnson, David; Khonsari, Roman H.; Fagan, Michael J.; Moazen, Mehran

2017-01-01

During the first year of life, the brain grows rapidly and the neurocranium increases to about 65% of its adult size. Our understanding of the relationship between the biomechanical forces, especially from the growing brain, the craniofacial soft tissue structures and the individual bone plates of the skull vault is still limited. This basic knowledge could help in the future planning of craniofacial surgical operations. The aim of this study was to develop a validated computational model of skull growth, based on the finite-element (FE) method, to help understand the biomechanics of skull growth. To do this, a two-step validation study was carried out. First, an in vitro physical three-dimensional printed model and an in silico FE model were created from the same micro-CT scan of an infant skull and loaded with forces from the growing brain from zero to two months of age. The results from the in vitro model validated the FE model before it was further developed to expand from 0 to 12 months of age. This second FE model was compared directly with in vivo clinical CT scans of infants without craniofacial conditions (n = 56). The various models were compared in terms of predicted skull width, length and circumference, while the overall shape was quantified using three-dimensional distance plots. Statistical analysis yielded no significant differences between the male skull models. All size measurements from the FE model versus the in vitro physical model were within 5%, with one exception showing a 7.6% difference. The FE model and in vivo data also correlated well, with the largest percentage difference in size being 8.3%. Overall, the FE model results matched well with both the in vitro and in vivo data. With further development and model refinement, this modelling method could be used to assist in preoperative planning of craniofacial surgery procedures and could help to reduce reoperation rates. PMID:28566514

Modelling human skull growth: a validated computational model.

PubMed

Libby, Joseph; Marghoub, Arsalan; Johnson, David; Khonsari, Roman H; Fagan, Michael J; Moazen, Mehran

2017-05-01

During the first year of life, the brain grows rapidly and the neurocranium increases to about 65% of its adult size. Our understanding of the relationship between the biomechanical forces, especially from the growing brain, the craniofacial soft tissue structures and the individual bone plates of the skull vault is still limited. This basic knowledge could help in the future planning of craniofacial surgical operations. The aim of this study was to develop a validated computational model of skull growth, based on the finite-element (FE) method, to help understand the biomechanics of skull growth. To do this, a two-step validation study was carried out. First, an in vitro physical three-dimensional printed model and an in silico FE model were created from the same micro-CT scan of an infant skull and loaded with forces from the growing brain from zero to two months of age. The results from the in vitro model validated the FE model before it was further developed to expand from 0 to 12 months of age. This second FE model was compared directly with in vivo clinical CT scans of infants without craniofacial conditions ( n = 56). The various models were compared in terms of predicted skull width, length and circumference, while the overall shape was quantified using three-dimensional distance plots. Statistical analysis yielded no significant differences between the male skull models. All size measurements from the FE model versus the in vitro physical model were within 5%, with one exception showing a 7.6% difference. The FE model and in vivo data also correlated well, with the largest percentage difference in size being 8.3%. Overall, the FE model results matched well with both the in vitro and in vivo data. With further development and model refinement, this modelling method could be used to assist in preoperative planning of craniofacial surgery procedures and could help to reduce reoperation rates. © 2017 The Author(s).

Strain in the Braincase and Its Sutures During Function

PubMed Central

Herring, Susan W.; Teng, Shengyi

2010-01-01

The skull is distinguished from other parts of the skeleton by its composite construction. The sutures between bony elements provide for interstitial growth of the cranium, but at the same time they alter the transmission of stress and strain through the skull. Strain gages were bonded to the frontal and parietal bones of miniature pigs and across the interfrontal, interparietal and coronal sutures. Strains were recorded 1) during natural mastication in conjunction with electromyographic activity from the jaw muscles and 2) during stimulation of various cranial muscles in anesthetized animals. Vault sutures exhibited vastly higher strains than did the adjoining bones. Further, bone strain primarily reflected torsion of the braincase set up by asymmetrical muscle contraction; the tensile axis alternated between +45° and −45° depending on which diagonal masseter/temporalis pair was most active. However, suture strains were not related to overall torsion but instead were responses to local muscle actions. Only the coronal suture showed significant strain (tension) during jaw opening; this was caused by the contraction of neck muscles. All sutures showed strain during jaw closing, but polarity depended on the pattern of muscle usage. For example, masseter contraction tensed the coronal suture and the anterior part of the interfrontal suture, whereas the temporalis caused compression in these locations. Peak tensile strains were larger than peak compressive strains. Histology suggested that the skull is bent at the sutures, with the ectocranial surface tensed and the endocranial surface predominantly compressed. Collectively, these results indicate that skulls with patent sutures should be analyzed as complexes of independent parts rather than solid structures. PMID:10918130

Do Muscles Constrain Skull Shape Evolution in Strepsirrhines?

PubMed

Fabre, Anne-Claire; Perry, Jonathan M G; Hartstone-Rose, Adam; Lowie, AuróLien; Boens, Andy; Dumont, MaÏtena

2018-02-01

Despite great interest and decades of research, the musculoskeletal relationships of the masticatory system in primates are still not fully understood. However, without a clear understanding of the interplay between muscles and bones it remains difficult to understand the functional significance of morphological traits of the skeleton. Here, we aim to study the impacts of the masticatory muscles on the shape of the cranium and the mandible as well as their co-variation in strepsirrhine primates. To do so, we use 3D geometric morphometric approaches to assess the shape of each bone of the skull of 20 species for which muscle data are available in the literature. Impacts of the masticatory muscles on the skull shape were assessed using non-phylogenetic regressions and phylogenetic regressions whereas co-variations were assessed using two-blocks partial least square (2B-PLS) and phylogenetic 2B-PLS. Our results show that there is a phylogenetic signal for skull shape and masticatory muscles. They also show that there is a significant impact of the masticatory muscles on cranial shape but not as much as on the mandible. The co-variations are also stronger between the masticatory muscles and cranial shape even when taking into account phylogeny. Interestingly, the results of co-variation between the masticatory muscles and mandibular shape show a more complex pattern in two different directions to get strong muscles associated with mandibular shape: a folivore way (with the bamboo lemurs and sifakas) and a hard-object eater one (with the aye-aye). Anat Rec, 301:291-310, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Immediate Placement of Ultrawide-Diameter Implants in Molar Sockets: Description of a Recommended Technique.

PubMed

Hattingh, André C; De Bruyn, Hugo; Ackermann, Andrew; Vandeweghe, Stefan

Immediate implant placement is performed less frequently in molar extraction sockets than in single root sockets. This is mainly due to the tripodal anatomical configuration of molar roots, which is perceived as complex and therefore unsuitable. The mechanical burden of molar sites, combined with much larger socket dimensions, make it amenable to the use of ultrawide-diameter dental implants. This article describes a practical, sequenced technique that can be used predictably for immediate implant placement in maxillary and mandibular first molar sockets, using a dry skull model for clarification. This detailed description is based on the experience of more than 580 clinical cases over a 10-year period.

Functional relationship between skull form and feeding mechanics in Sphenodon, and implications for diapsid skull development.

PubMed

Curtis, Neil; Jones, Marc E H; Shi, Junfen; O'Higgins, Paul; Evans, Susan E; Fagan, Michael J

2011-01-01

The vertebrate skull evolved to protect the brain and sense organs, but with the appearance of jaws and associated forces there was a remarkable structural diversification. This suggests that the evolution of skull form may be linked to these forces, but an important area of debate is whether bone in the skull is minimised with respect to these forces, or whether skulls are mechanically "over-designed" and constrained by phylogeny and development. Mechanical analysis of diapsid reptile skulls could shed light on this longstanding debate. Compared to those of mammals, the skulls of many extant and extinct diapsids comprise an open framework of fenestrae (window-like openings) separated by bony struts (e.g., lizards, tuatara, dinosaurs and crocodiles), a cranial form thought to be strongly linked to feeding forces. We investigated this link by utilising the powerful engineering approach of multibody dynamics analysis to predict the physiological forces acting on the skull of the diapsid reptile Sphenodon. We then ran a series of structural finite element analyses to assess the correlation between bone strain and skull form. With comprehensive loading we found that the distribution of peak von Mises strains was particularly uniform throughout the skull, although specific regions were dominated by tensile strains while others were dominated by compressive strains. Our analyses suggest that the frame-like skulls of diapsid reptiles are probably optimally formed (mechanically ideal: sufficient strength with the minimal amount of bone) with respect to functional forces; they are efficient in terms of having minimal bone volume, minimal weight, and also minimal energy demands in maintenance. © 2011 Curtis et al.

Does skull morphology constrain bone ornamentation? A morphometric analysis in the Crocodylia.

PubMed

Clarac, F; Souter, T; Cubo, J; de Buffrénil, V; Brochu, C; Cornette, R

2016-08-01

Previous quantitative assessments of the crocodylians' dermal bone ornamentation (this ornamentation consists of pits and ridges) has shown that bone sculpture results in a gain in area that differs between anatomical regions: it tends to be higher on the skull table than on the snout. Therefore, a comparative phylogenetic analysis within 17 adult crocodylian specimens representative of the morphological diversity of the 24 extant species has been performed, in order to test if the gain in area due to ornamentation depends on the skull morphology, i.e. shape and size. Quantitative assessment of skull size and shape through geometric morphometrics, and of skull ornamentation through surface analyses, produced a dataset that was analyzed using phylogenetic least-squares regression. The analyses reveal that none of the variables that quantify ornamentation, be they on the snout or the skull table, is correlated with the size of the specimens. Conversely, there is more disparity in the relationships between skull conformations (longirostrine vs. brevirostrine) and ornamentation. Indeed, both parameters GApit (i.e. pit depth and shape) and OArelat (i.e. relative area of the pit set) are negatively correlated with snout elongation, whereas none of the values quantifying ornamentation on the skull table is correlated with skull conformation. It can be concluded that bone sculpture on the snout is influenced by different developmental constrains than on the skull table and is sensible to differences in the local growth 'context' (allometric processes) prevailing in distinct skull parts. Whatever the functional role of bone ornamentation on the skull, if any, it seems to be restricted to some anatomical regions at least for the longirostrine forms that tend to lose ornamentation on the snout. © 2016 Anatomical Society.

Reappraisal of Pediatric Diastatic Skull Fractures in the 3-Dimensional CT Era: Clinical Characteristics and Comparison of Diagnostic Accuracy of Simple Skull X-Ray, 2-Dimensional CT, and 3-Dimensional CT.

PubMed

Sim, Sook Young; Kim, Hyun Gi; Yoon, Soo Han; Choi, Jong Wook; Cho, Sung Min; Choi, Mi Sun

2017-12-01

Diastatic skull fractures (DSFs) in children are difficult to detect in skull radiographs before they develop into growing skull fractures; therefore, little information is available on this topic. However, recent advances in 3-dimensional (3D) computed tomography (CT) imaging technology have enabled more accurate diagnoses of almost all forms of skull fracture. The present study was undertaken to document the clinical characteristics of DSFs in children and to determine whether 3D CT enhances diagnostic accuracy. Two hundred and ninety-two children younger than 12 years with skull fractures underwent simple skull radiography, 2-dimensional (2D) CT, and 3DCT. Results were compared with respect to fracture type, location, associated lesions, and accuracy of diagnosis. DSFs were diagnosed in 44 (15.7%) of children with skull fractures. Twenty-two patients had DSFs only, and the other 22 had DSFs combined with compound or mixed skull fractures. The most common fracture locations were the occipitomastoid (25%) and lambdoid (15.9%). Accompanying lesions consisted of subgaleal hemorrhages (42/44), epidural hemorrhages (32/44), pneumocephalus (17/44), and subdural hemorrhages (3/44). A total of 17 surgical procedures were performed on 15 of the 44 patients. Fourteen and 19 patients were confirmed to have DSFs by skull radiography and 2D CT, respectively, but 3D CT detected DSFs in 43 of the 44 children (P < 0.001). 3D CT was found to be markedly superior to skull radiography or 2D CT for detecting DSFs. This finding indicates that 3D CT should be used routinely rather than 2D CT for the assessment of pediatric head trauma. Copyright © 2017 Elsevier Inc. All rights reserved.

Molding of top skull in the treatment of Apert syndrome.

PubMed

Shen, Weimin; Cui, Jie; Chen, Jianbin; Weiping, Shen

2015-03-01

Patients with Apert syndrome have bilateral coronal craniosynostosis, along with a distinguishing feature of their many deformity, called tower skull. Surgical correction of this deformity is the mainstay of treatment. We describe 3 patients molded top skull after front bone osteotomy orbital bar advancement. This successfully restricted growth of their top skull while allowing growth in other dimensions. Utilization of top-skull molding after cranial surgery shows promise of satisfaction in this setting.

Arterial relationships to the nerves and some rigid structures in the posterior cranial fossa.

PubMed

Surchev, N

2008-09-01

The close relationships between the cranial nerves and the arterial vessels in the posterior cranial fossa are one of the predisposing factors for artery-nerve compression. The aim of this study was to examine the relationships of the vertebral and basilar arteries to some skull and dural structures and the nerves in the posterior cranial fossa. For this purpose, the skull bases and brains of 70 cadavers were studied. The topographic relationships of the vertebral and basilar arteries to the cranial nerves in the posterior cranial fossa were studied and the distances between the arteries and some osseous formations were measured. The most significant variations in arterial position were registered in the lower half of the basilar artery. Direct contact with an artery was established for the hypoglossal canal, jugular tubercle, and jugular foramen. The results reveal additional information about the relationships of the nerves and arteries to the skull and dural formations in the posterior cranial fossa. New quantitative information is given to illustrate them. The conditions for possible artery-nerve compression due to arterial dislocation are discussed and two groups (lines) of compression points are suggested. The medial line comprises of the brain stem points, usually the nerve root entry/exit zone. The lateral line includes the skull eminences, on which the nerves lie, or skull and dural foramina through which they exit the cranial cavity. (c) 2008 Wiley-Liss, Inc.

An optimal set of landmarks for metopic craniosynostosis diagnosis from shape analysis of pediatric CT scans of the head

NASA Astrophysics Data System (ADS)

Mendoza, Carlos S.; Safdar, Nabile; Myers, Emmarie; Kittisarapong, Tanakorn; Rogers, Gary F.; Linguraru, Marius George

2013-02-01

Craniosynostosis (premature fusion of skull sutures) is a severe condition present in one of every 2000 newborns. Metopic craniosynostosis, accounting for 20-27% of cases, is diagnosed qualitatively in terms of skull shape abnormality, a subjective call of the surgeon. In this paper we introduce a new quantitative diagnostic feature for metopic craniosynostosis derived optimally from shape analysis of CT scans of the skull. We built a robust shape analysis pipeline that is capable of obtaining local shape differences in comparison to normal anatomy. Spatial normalization using 7-degree-of-freedom registration of the base of the skull is followed by a novel bone labeling strategy based on graph-cuts according to labeling priors. The statistical shape model built from 94 normal subjects allows matching a patient's anatomy to its most similar normal subject. Subsequently, the computation of local malformations from a normal subject allows characterization of the points of maximum malformation on each of the frontal bones adjacent to the metopic suture, and on the suture itself. Our results show that the malformations at these locations vary significantly (p<0.001) between abnormal/normal subjects and that an accurate diagnosis can be achieved using linear regression from these automatic measurements with an area under the curve for the receiver operating characteristic of 0.97.

Hyperostotic Esthesioneuroblastoma: Rare Variant and Fibrous Dysplasia Mimicker

PubMed Central

Knott, Phillip Daniel

2014-01-01

A 65-year-old male presented with a 3-year history of orbital symptoms. An imaging-based diagnosis of fibrous dysplasia involving the skull base was made at another institution. CT showed a diffuse sinonasal mass and ground-glass appearance of the bones of the anterior skull base with bony defects and mucocele formation. MRI demonstrated an accompanying intracranial and orbital rind of soft tissue mass along the hyperostotic bones. FDG-PET showed corresponding intense hypermetabolism. Small cysts were observed at the tumor-brain interface. Biopsy revealed esthesioneuroblastoma with bone infiltration that is compatible with the hyperostotic variant of esthesioneuroblastoma. There are a few cases of hyperostotic esthesioneuroblastoma reported in the literature. PMID:24497807

Shape and mechanics in thalattosuchian (Crocodylomorpha) skulls: implications for feeding behaviour and niche partitioning

PubMed Central

Pierce, S E; Angielczyk, K D; Rayfield, E J

2009-01-01

Variation in modern crocodilian and extinct thalattosuchian crocodylomorph skull morphology is only weakly correlated with phylogeny, implying that factors other than evolutionary proximity play important roles in determining crocodile skull shape. To further explore factors potentially influencing morphological differentiation within the Thalattosuchia, we examine teleosaurid and metriorhynchid skull shape variation within a mechanical and dietary context using a combination of finite element modelling and multivariate statistics. Patterns of stress distribution through the skull were found to be very similar in teleosaurid and metriorhynchid species, with stress peaking at the posterior constriction of the snout and around the enlarged supratemporal fenestrae. However, the magnitudes of stresses differ, with metriorhynchids having generally stronger skulls. As with modern crocodilians, a strong linear relationship between skull length and skull strength exists, with short-snouted morphotypes experiencing less stress through the skull than long-snouted morphotypes under equivalent loads. Selection on snout shape related to dietary preference was found to work in orthogonal directions in the two families: diet is associated with snout length in teleosaurids and with snout width in metriorhynchids, suggesting that teleosaurid skulls were adapted for speed of attack and metriorhynchid skulls for force production. Evidence also indicates that morphological and functional differentiation of the skull occurred as a result of dietary preference, allowing closely related sympatric species to exploit a limited environment. Comparisons of the mechanical performance of the thalattosuchian skull with extant crocodilians show that teleosaurids and long-snouted metriorhynchids exhibit stress magnitudes similar to or greater than those of long-snouted modern forms, whereas short-snouted metriorhynchids display stress magnitudes converging on those found in short-snouted modern species. As a result, teleosaurids and long-snouted metriorhynchids were probably restricted to lateral attacks of the head and neck, but short-snouted metriorhynchids may have been able to employ the grasp and shake and/or ‘death roll’ feeding and foraging behaviours. PMID:19702868

Skull Practice.

ERIC Educational Resources Information Center

Slesnick, Irwin L.

1988-01-01

Disguises a lesson about skulls with some fun to cause less fear among students. Outlines strategies, questions, and answers for use. Includes a skull mask which can be photocopied and distributed to students as a learning tool and a fun Halloween treat. Also shown is a picture of skull parts. (RT)

Study of mastoid canals and grooves in north karnataka human skulls.

PubMed

Hadimani, Gavishiddappa Andanappa; Bagoji, Ishwar Basavantappa

2013-08-01

This study was undertaken to observe the frequency of mastoid canals and grooves in north Karnataka dry human skulls. 100 dry human skulls of unknown age and sex from the department of Anatomy were selected and observed for the present study. The mastoid regions of dry skulls were observed for the presence of mastoid canals and grooves, if any. A metallic wire was passed through the canal for its confirmation and then the length was measured. The Mastoid canals were present in 53% of the total 100 skulls observed either bilaterally or unilaterally. Mastoid grooves were present in 18% of the total skulls (100) observed. Double mastoid canal was found in 01% of total skull studied and both Mastoid canals & Mastoid grooves together were present in 02% of the total skulls (100) observed. The knowledge of mastoid canals and grooves is very important for otolaryngologists and neurosurgeons. Because they contain an arterial branch of occipital artery with its accompanying vein which is liable to injury resulting into severe bleeding.

Orbit-associated tumors: navigation and control of resection using intraoperative computed tomography.

PubMed

Terpolilli, Nicole A; Rachinger, Walter; Kunz, Mathias; Thon, Niklas; Flatz, Wilhelm H; Tonn, Jörg-Christian; Schichor, Christian

2016-05-01

OBJECT Treatment of skull base lesions is complex and usually requires a multidisciplinary approach. In meningioma, which is the most common tumor entity in this region, resection is considered to be the most important therapeutic step to avoid tumor recurrence. However, resection of skull base lesions with orbital or optic nerve involvement poses a challenge due to their anatomical structure and their proximity to eloquent areas. Therefore the main goal of surgery should be to achieve the maximum extent of resection while preserving neurological function. In the postoperative course, medical and radiotherapeutic strategies may then be successfully used to treat possible tumor residues. Methods to safely improve the extent of resection in skull base lesions therefore are desirable. The current study reports the authors' experience with the use of intraoperative CT (iCT) combined with neuronavigation with regard to feasibility and possible benefits of the method. METHODS Those patients with tumorous lesions in relationship to the orbit, sphenoid wing, or cavernous sinus who were surgically treated between October 2008 and December 2013 using iCT-based neuronavigation and in whom an intraoperative scan was obtained for control of resection were included. In all cases a second iCT scan was performed under sterile conditions after completion of navigation-guided microsurgical tumor resection. The surgical strategy was adapted accordingly; if necessary, resection was continued. RESULTS Twenty-three patients (19 with WHO Grade I meningioma and 4 with other lesions) were included. The most common clinical symptoms were loss of visual acuity and exophthalmus. Intraoperative control of resection by iCT was successfully obtained in all cases. Intraoperative imaging changed the surgical approach in more than half (52.2%) of these patients, either because iCT demonstrated unexpected residual tumor masses or because the second scan revealed additional tumor tissue that was not detected in the first scan due to overlay by osseous tumor parts; in these cases resection was continued. In the remaining cases resection was concluded as planned because iCT verified the surgeon's microscopic estimation of tumor resection status. Postoperative visual outcome was favorable in more than 80% of patients. CONCLUSIONS Intraoperative CT allows control of resection in case of uncertainty and can help to improve the extent of maximal safe resection, especially in case of osseous tumor parts and masses within the orbit.

Trans-zygomatic middle cranial fossa approach to access lesions around the cavernous sinus and anterior parahippocampus: a minimally invasive skull base approach.

PubMed

Melamed, Itay; Tubbs, R Shane; Payner, Troy D; Cohen-Gadol, Aaron A

2009-08-01

Exposure of the cavernous sinus or anterior parahippocampus often involves a wide exposure of the temporal lobe and mobilization of the temporalis muscle associated with temporal lobe retraction. The authors present a cadaveric study to illustrate the feasibility, advantages and landmarks necessary to perform a trans-zygomatic middle fossa approach to lesions around the cavernous sinus and anterior parahippocampus. The authors performed bilateral trans-zygomatic middle fossae exposures to reach the cavernous sinus and parahippocampus in five cadavers (10 sides). We assessed the morbidity associated with this procedure and compared the indications, advantages, and disadvantages of this method versus more extensive skull base approaches. A vertical linear incision along the middle portion of the zygomatic arch was extended one finger breadth inferior to the inferior edge of the zygomatic arch. Careful dissection inferior to the arch allowed preservation of facial nerve branches. A zygomatic osteotomy was followed via a linear incision through the temporalis muscle and exposure of the middle cranial fossa floor. A craniotomy along the inferolateral temporal bone and middle fossa floor allowed extradural dissection along the middle fossa floor and exposure of the cavernous sinus including all three divisions of the trigeminal nerve. Intradural inspection demonstrated adequate exposure of the parahippocampus. Exposure of the latter required minimal or no retraction of the temporal lobe. The trans-zygomatic middle fossa approach is a simplified skull base exposure using a linear incision, which may avoid the invasivity of more extensive skull base approaches while providing an adequate corridor for resection of cavernous sinus and parahippocampus lesions. The advantages of this approach include its efficiency, ease, minimalism, preservation of the temporalis muscle, and minimal retraction of the temporal lobe.

[Management of occult malformations at the lateral skull base].

PubMed

Bryson, E; Draf, W; Hofmann, E; Bockmühl, U

2005-12-01

Occult malformations of the lateral skull base are rare anomalies, but can cause severe complications such as recurrent meningitis. Therefore, they need to be precisely delineated and sufficient surgical closure is mandatory. Between 1986 and 2004 twenty patients (10 children and 10 adults) with occult malformations at the lateral skull base were treated surgically at the ENT-Department of the Hospital Fulda gAG. Of these 3 Mondini-malformations, 11 defects of the tegmen tympani or the mastoidal roof, 2 dural lesions to the posterior fossa and 4 malformations within the pyramidal apex have been found. Four patients have had multiple anomalies. Routing symptom was in all cases at least one previous meningitis. Radiological diagnostics included high-resolution computed tomography (CT) and magnetic resonance imaging (MRI) as well as CT- or MR-cisternography. Depending on type and localisation of the defect the following surgical algorithm was carried out: The trans-mastoidal approach was used in all cases of Mondini-malformation (including obliteration of the ear), in case of lesions to the posterior fossa as well as partly in anomalies at the tegmen tympani and mastoidal roof, respectively. Defects of the pyramidal apex should be explored via the trans-mastoidal way if the lesion is located caudally to the inner auditory canal (IAC), whereas the trans-temporal approach should be used if the lesion is situated ventral to the IAC and dorso-medially to the internal carotid artery (ICA). The trans-temporal approach was also performed in large defects of the tegmen tympani and mastoidal roof as well as in recurrences. In all cases of recurrent meningitis caused by agents of the upper airway tract the basic principle should be to search for occult skull base malformations radiologically as well as by sodium fluorescein endoscopy as long as the anomaly is detected.

Geometric and mechanical evaluation of 3D-printing materials for skull base anatomical education and endoscopic surgery simulation - A first step to create reliable customized simulators.

PubMed

Favier, Valentin; Zemiti, Nabil; Caravaca Mora, Oscar; Subsol, Gérard; Captier, Guillaume; Lebrun, Renaud; Crampette, Louis; Mondain, Michel; Gilles, Benjamin

2017-01-01

Endoscopic skull base surgery allows minimal invasive therapy through the nostrils to treat infectious or tumorous diseases. Surgical and anatomical education in this field is limited by the lack of validated training models in terms of geometric and mechanical accuracy. We choose to evaluate several consumer-grade materials to create a patient-specific 3D-printed skull base model for anatomical learning and surgical training. Four 3D-printed consumer-grade materials were compared to human cadaver bone: calcium sulfate hemihydrate (named Multicolor), polyamide, resin and polycarbonate. We compared the geometric accuracy, forces required to break thin walls of materials and forces required during drilling. All materials had an acceptable global geometric accuracy (from 0.083mm to 0.203mm of global error). Local accuracy was better in polycarbonate (0.09mm) and polyamide (0.15mm) than in Multicolor (0.90mm) and resin (0.86mm). Resin and polyamide thin walls were not broken at 200N. Forces needed to break Multicolor thin walls were 1.6-3.5 times higher than in bone. For polycarbonate, forces applied were 1.6-2.5 times higher. Polycarbonate had a mode of fracture similar to the cadaver bone. Forces applied on materials during drilling followed a normal distribution except for the polyamide which was melted. Energy spent during drilling was respectively 1.6 and 2.6 times higher on bone than on PC and Multicolor. Polycarbonate is a good substitute of human cadaver bone for skull base surgery simulation. Thanks to short lead times and reasonable production costs, patient-specific 3D printed models can be used in clinical practice for pre-operative training, improving patient safety.

[Management of cerebrospinal fluid leaks according to size. Our experience].

PubMed

Alobid, Isam; Enseñat, Joaquim; Rioja, Elena; Enriquez, Karla; Viscovich, Liza; de Notaris, Matteo; Bernal-Sprekelsen, Manuel

2014-01-01

We present our experience in the reconstruction of cerebrospinal fluid (CSF) leaks according to their size and location. Fifty-four patients who underwent advanced skull base surgery (large defects) and 62 patients with CSF leaks of different origin (small and medium-sized defects) were included. Large defects were reconstructed with a nasoseptal pedicled flap positioned on fat and fascia lata and lumbar drainage was used. In small and medium-sized leaks of other origin, intrathecal fluorescein 5% was applied previously to identify the defect. Fascia lata in an underlay position was used for reconstruction, which was then covered with mucoperiosteum from the turbinate. Perioperative antibiotics were administered for 5-7 days. Nasal packing was removed after 24-48 hours. The most frequent aetiology for small and medium-sized defects was spontaneous (48.4%), followed by trauma (24.2%), iatrogenic (5%) and others. The success rate was of 91% after the first surgery and 98% in large skull base defects and small/medium-sized respectively. After rescue surgery, the rate of closure achieved was 100%. The follow-up was 15.6 ± 12.4 months for large defects and 75.3 ± 51.3 months for small/medium-sized defects without recurrence. Endoscopic surgery for closure of any type of skull base defect is the gold standard approach. Defect size does not play a significant role in the success rate. Fascia lata and mucoperiosteum allow a reconstruction of small/medium-sized defects. For larger skull base defects, a combination of fat, fascia lata and nasoseptal pedicled flaps provide a successful reconstruction. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Endoscopic endonasal surgery for benign fibro-osseous lesions of the pediatric skull base.

PubMed

Stapleton, Amanda L; Tyler-Kabara, Elizabeth C; Gardner, Paul A; Snyderman, Carl H

2015-09-01

To describe the presentation, treatment, and outcomes of benign fibro-osseous tumors involving the skull base in a pediatric population. Retrospective chart review from January 2002 to September 2013 of pediatric patients (ages 0-18 years) who underwent endoscopic endonasal surgery (EES) for benign fibro-osseous tumors involving the skull base. Fourteen patients were identified with an age range of 2.7 to 17.9 years (mean, 12.5 years). Six juvenile ossifying fibromas, five benign fibro-osseous lesions, two osteomas, and one fibrous dysplasia were treated. Ocular symptoms and nasal obstruction were the most common presenting symptoms in nine (64%) and six (43%) of patients, respectively; five (36%) presented with proptosis and four (29%) with diplopia. Two (14%) patients had cranial nerve VI palsy. Transsellar and transclival approaches were used in five (36%) of patients. Orbital and optic nerve decompressions were the most common components of the approaches performed in nine (64%) of the surgeries. Gross total resection (GTR) was achieved with single-stage surgery in 10 (71%) patients; two additional patients underwent staged GTR. Two intraoperative cerebrospinal fluid (CSF) leaks occurred and were repaired endoscopically. There were no postoperative CSF leaks or infectious complications. Two patients had transient diplopia, and two had transient diabetes insipidus, all of which resolved. The mean follow-up was 13.8 months. Two patients had a recurrence, and both required additional EES achieving GTR. EES for benign fibro-osseous tumors of the skull base is a safe and effective treatment for excision of these lesions in the pediatric population. 4. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Skull metastases detecting on arterial spin labeling perfusion: Three case reports and review of literature.

PubMed

Ryu, Kyeong H; Baek, Hye J; Cho, Soo B; Moon, Jin I; Choi, Bo H; Park, Sung E; An, Hyo J

2017-11-01

Detection of skull metastases is as important as detection of brain metastases because early diagnosis of skull metastases is a crucial determinant of treatment. However, the skull can be a blind spot for assessing metastases on routine brain magnetic resonance imaging (MRI). To the best of our knowledge, the finding of skull metastases on arterial spin labeling (ASL) has not been reported. ASL is a specific MRI sequence for evaluating cerebral blood flow using magnetized endogenous inflow blood. This study uses ASL as a routine sequence of brain MRI protocol and describes 3 clinical cases of skull metastases identified by ASL. The study also highlights the clinical usefulness of ASL in detecting skull metastases. Three patients with known malignancy underwent brain MRI to evaluate for brain metastases. All of the skull metastases were conspicuously depicted on routine ASL images, and the lesions correlated well with other MRI sequences. Three patients received palliative chemotherapy. Three patients are being followed up regularly at the outpatient department. The routine use of ASL may help to detect lesions in blind spots, such as skull metastases, and to facilitate the evaluation of intracranial pathologies without the use of contrast materials in exceptional situations.

Creating a normative database of age-specific 3D geometrical data, bone density, and bone thickness of the developing skull: a pilot study.

PubMed

Delye, Hans; Clijmans, Tim; Mommaerts, Maurice Yves; Sloten, Jos Vnder; Goffin, Jan

2015-12-01

Finite element models (FEMs) of the head are used to study the biomechanics of traumatic brain injury and depend heavily on the use of accurate material properties and head geometry. Any FEM aimed at investigating traumatic head injury in children should therefore use age-specific dimensions of the head, as well as age-specific material properties of the different tissues. In this study, the authors built a database of age-corrected skull geometry, skull thickness, and bone density of the developing skull to aid in the development of an age-specific FEM of a child's head. Such a database, containing age-corrected normative skull geometry data, can also be used for preoperative surgical planning and postoperative long-term follow-up of craniosynostosis surgery results. Computed tomography data were processed for 187 patients (age range 0-20 years old). A 3D surface model was calculated from segmented skull surfaces. Skull models, reference points, and sutures were processed into a MATLAB-supported database. This process included automatic calculation of 2D measurements as well as 3D measurements: length of the coronal suture, length of the lambdoid suture, and the 3D anterior-posterior length, defined as the sum of the metopic and sagittal suture. Skull thickness and skull bone density calculations were included. Cephalic length, cephalic width, intercoronal distance, lateral orbital distance, intertemporal distance, and 3D measurements were obtained, confirming the well-established general growth pattern of the skull. Skull thickness increases rapidly in the first year of life, slowing down during the second year of life, while skull density increases with a fast but steady pace during the first 3 years of life. Both skull thickness and density continue to increase up to adulthood. This is the first report of normative data on 2D and 3D measurements, skull bone thickness, and skull bone density for children aged 0-20 years. This database can help build an age-specific FEM of a child's head. It can also help to tailor preoperative virtual planning in craniosynostosis surgery toward patient-specific normative target values and to perform objective long-term follow-up in craniosynostosis surgery.

3D Printed, Customized Cranial Implant for Surgical Planning

NASA Astrophysics Data System (ADS)

Bogu, Venkata Phanindra; Ravi Kumar, Yennam; Asit Kumar, Khanra

2018-06-01

The main objective of the present work is to model cranial implant and printed in FDM machine (printer model used: mojo). Actually this is peculiar case and the skull has been damaged in frontal, parietal and temporal regions and a small portion of frontal region damaged away from saggital plane, complexity is to fill this frontal region with proper curvature. The Patient CT-data (Number of slices was 381 and thickness of each slice is 0.488 mm) was processed in mimics14.1 software, mimics file was sent to 3-matic software and calculated thickness of skull at different sections where cranial implant is needed then corrected the edges of cranial implant to overcome CSF (cerebrospinal fluid) leakage and proper fitting. Finally the implant average thickness is decided as 2.5 mm and printed in FDM machine with ABS plastic.

3D Printed, Customized Cranial Implant for Surgical Planning

NASA Astrophysics Data System (ADS)

Bogu, Venkata Phanindra; Ravi Kumar, Yennam; Asit Kumar, Khanra

2016-06-01

The main objective of the present work is to model cranial implant and printed in FDM machine (printer model used: mojo). Actually this is peculiar case and the skull has been damaged in frontal, parietal and temporal regions and a small portion of frontal region damaged away from saggital plane, complexity is to fill this frontal region with proper curvature. The Patient CT-data (Number of slices was 381 and thickness of each slice is 0.488 mm) was processed in mimics14.1 software, mimics file was sent to 3-matic software and calculated thickness of skull at different sections where cranial implant is needed then corrected the edges of cranial implant to overcome CSF (cerebrospinal fluid) leakage and proper fitting. Finally the implant average thickness is decided as 2.5 mm and printed in FDM machine with ABS plastic.

Anatomical and computed tomographic analysis of the transcochlear and endoscopic transclival approaches to the petroclival region.

PubMed

Mason, Eric; Van Rompaey, Jason; Carrau, Ricardo; Panizza, Benedict; Solares, C Arturo

2014-03-01

Advances in the field of skull base surgery aim to maximize anatomical exposure while minimizing patient morbidity. The petroclival region of the skull base presents numerous challenges for surgical access due to the complex anatomy. The transcochlear approach to the region provides adequate access; however, the resection involved sacrifices hearing and results in at least a grade 3 facial palsy. An endoscopic endonasal approach could potentially avoid negative patient outcomes while providing a desirable surgical window in a select patient population. Cadaveric study. Endoscopic access to the petroclival region was achieved through an endonasal approach. For comparison, a transcochlear approach to the clivus was performed. Different facets of the dissections, such as bone removal volume and exposed surface area, were computed using computed tomography analysis. The endoscopic endonasal approach provided a sufficient corridor to the petroclival region with significantly less bone removal and nearly equivalent exposure of the surgical target, thus facilitating the identification of the relevant anatomy. The lateral approach allowed for better exposure from a posterolateral direction until the inferior petrosal sinus; however, the endonasal approach avoided labyrinthine/cochlear destruction and facial nerve manipulation while providing an anteromedial viewpoint. The endonasal approach also avoided external incisions and cosmetic deficits. The endonasal approach required significant sinonasal resection. Endoscopic access to the petroclival region is a feasible approach. It potentially avoids hearing loss, facial nerve manipulation, and cosmetic damage. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Volumetric modulated arc therapy versus step-and-shoot intensity modulated radiation therapy in the treatment of large nerve perineural spread to the skull base: a comparative dosimetric planning study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorayski, Peter; Fitzgerald, Rhys; Barry, Tamara

Cutaneous squamous cell carcinoma with large nerve perineural (LNPN) infiltration of the base of skull is a radiotherapeutic challenge given the complex target volumes to nearby organs at risk (OAR). A comparative planning study was undertaken to evaluate dosimetric differences between volumetric modulated arc therapy (VMAT) versus intensity modulated radiation therapy (IMRT) in the treatment of LNPN. Five consecutive patients previously treated with IMRT for LNPN were selected. VMAT plans were generated for each case using the same planning target volumes (PTV), dose prescriptions and OAR constraints as IMRT. Comparative parameters used to assess target volume coverage, conformity and homogeneitymore » included V95 of the PTV (volume encompassed by the 95% isodose), conformity index (CI) and homogeneity index (HI). In addition, OAR maximum point doses, V20, V30, non-target tissue (NTT) point max doses, NTT volume above reference dose, monitor units (MU) were compared. IMRT and VMAT plans generated were comparable for CI (P = 0.12) and HI (P = 0.89). VMAT plans achieved better V95 (P = < 0.001) and reduced V20 and V30 by 652 cubic centimetres (cc) (28.5%) and 425.7 cc (29.1%), respectively. VMAT increased MU delivered by 18% without a corresponding increase in NTT dose. Compared with IMRT plans for LNPN, VMAT achieved comparable HI and CI.« less

Use of Pedicled Trapezius Myocutaneous Flap for Posterior Skull Reconstruction.

PubMed

Singh, Mansher; Rios Diaz, Arturo J; Cauley, Ryan; Smith, Timothy R; Caterson, E J

2015-09-01

Soft-tissue defects in posterior skull can be challenging for reconstruction. If related to tumor resection, these wound beds are generally irradiated and can be difficult from a recipient-vessel perspective for a free tissue transfer. Locoregional flaps might prove to be important reconstructive option in such patients. There is a very limited data on the usage of pedicled trapezius myocutaneous flaps for such defects. The authors reviewed existing study for usage of trapezius flap for posterior skull repair and used pedicled trapezius myocutaneous flaps based on the descending branch of superficial cervical artery (SCA) for reconstruction of posterior skull soft-tissue defect in an irradiated and infected wound. Two patients were operated for trapezius myocutaneous flap for posterior skull defects complicated by cerebrospinal fluid (CSF) leakage and epidural abscess. There was no recipient or donor-site complication at a mean follow-up of 12.5 months. Neither of the 2 patients had any functional deficits for the entire duration of the follow-up. Although this flap was able to help in controlling the CSF leakage in the first patient, it successfully healed the cavity generated from epidural abscess drainage in the second patient. The large angle of rotation coupled with the ability to complete the procedure without repositioning the patients makes trapezius myocutaneous flap an attractive option for posterior skull reconstruction. In our limited experience, the pedicled trapezius flaps are a reliable alternative as they are well vascularized and able to obliterate the soft-tissue defect completely. The recipient site healed completely in infected as well as irradiated wound beds. In addition, the donor site can be primarily closed with minimal donor-associated complication.

[Skull cult. Trophy heads and tzantzas in pre-Columbian America].

PubMed

Carod-Artal, F J

2012-07-16

The skull cult is a cultural tradition that dates back to at least Neolithic times. Its main manifestations are trophy heads, skull masks, moulded skulls and shrunken heads. The article reviews the skull cult in both pre-Columbian America and the ethnographic present from a neuro-anthropological perspective. The tradition of shaping and painting the skulls of ancestors goes back to the Indo-European Neolithic period (Natufian culture and Gobekli Tepe). In Mesoamerica, post-mortem decapitation was the first step of a mortuary treatment that resulted in a trophy head, a skull for the tzompantli or a skull mask. The lithic technology utilised by the Mesoamerican cultures meant that disarticulation had to be performed in several stages. Tzompantli is a term that refers both to a construction where the heads of victims were kept and to the actual skulls themselves. Skull masks are skulls that have been artificially modified in order to separate and decorate the facial part; they have been found in the Templo Mayor of Tenochtitlan. The existence of trophy heads is well documented by means of iconographic representations on ceramic ware and textiles belonging to the Paraca, Nazca and Huari cultures of Peru. The Mundurucu Indians of Brazil and the Shuar or Jivaroan peoples of Amazonian Ecuador have maintained this custom down to the present day. The Shuar also shrink heads (tzantzas) in a ritual process. Spanish chroniclers such as Fray Toribio de Benavente 'Motolinia' and Gaspar de Carvajal spoke of these practices. In pre-Columbian America, the tradition of decapitating warriors in order to obtain trophy heads was a wide-spread and highly developed practice.

Phantom-based evaluation method for surgical assistance devices in minimally invasive cochlear implantation

NASA Astrophysics Data System (ADS)

Lexow, G. Jakob; Kluge, Marcel; Majdani, Omid; Lenarz, Thomas; Rau, Thomas S.

2017-03-01

Several research groups have proposed individual solutions for surgical assistance devices to perform minimally invasive cochlear implantation. The main challenge is the drilling of a small bore hole from the surface of the skull to the inner ear at submillimetric accuracy. Each group tested the accuracy of their device in their respective test bench or in a small number of temporal bone specimens. This complicates the comparison of the different approaches. Thus, a simple and inexpensive phantom based evaluation method is proposed which resembles clinical conditions. The method is based on half-skull phantoms made of bone-substitute material - optionally equipped with an artificial skin replica to include skin incision within the evaluation procedure. Anatomical structures of the temporal bone derived from segmentations using clinical imaging data are registered into a computer tomographic scan of the skull phantom and used for the planning of the drill trajectory. Drilling is performed with the respective device under conditions close to the intraoperative setting. Evaluation of accuracy can either be performed through postoperative imaging or by means of added targets on the inside of the skull model. Two different targets are proposed: simple reference marks only for measuring the accuracy of the device and a target containing a scala tympani model for evaluation of the complete workflow including the insertion of the electrode carrier. Experiments using the presented method take place under reproducible conditions thus allowing the comparison of the different approaches. In addition, artificial phantoms are easier to obtain and handle than human specimens.

21 CFR 882.4750 - Skull punch.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Skull punch. 882.4750 Section 882.4750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4750 Skull punch. (a) Identification. A skull punch is...

21 CFR 882.5960 - Skull tongs for traction.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Skull tongs for traction. 882.5960 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5960 Skull tongs for traction. (a) Identification. Skull tongs for traction is an instrument used to immobilize a patient with a...

Planning of skull reconstruction based on a statistical shape model combined with geometric morphometrics.

PubMed

Fuessinger, Marc Anton; Schwarz, Steffen; Cornelius, Carl-Peter; Metzger, Marc Christian; Ellis, Edward; Probst, Florian; Semper-Hogg, Wiebke; Gass, Mathieu; Schlager, Stefan

2018-04-01

Virtual reconstruction of large cranial defects is still a challenging task. The current reconstruction procedures depend on the surgeon's experience and skills in planning the reconstruction based on mirroring and manual adaptation. The aim of this study is to propose and evaluate a computer-based approach employing a statistical shape model (SSM) of the cranial vault. An SSM was created based on 131 CT scans of pathologically unaffected adult crania. After segmentation, the resulting surface mesh of one patient was established as template and subsequently registered to the entire sample. Using the registered surface meshes, an SSM was generated capturing the shape variability of the cranial vault. The knowledge about this shape variation in healthy patients was used to estimate the missing parts. The accuracy of the reconstruction was evaluated by using 31 CT scans not included in the SSM. Both unilateral and bilateral bony defects were created on each skull. The reconstruction was performed using the current gold standard of mirroring the intact to the affected side, and the result was compared to the outcome of our proposed SSM-driven method. The accuracy of the reconstruction was determined by calculating the distances to the corresponding parts on the intact skull. While unilateral defects could be reconstructed with both methods, the reconstruction of bilateral defects was, for obvious reasons, only possible employing the SSM-based method. Comparing all groups, the analysis shows a significantly higher precision of the SSM group, with a mean error of 0.47 mm compared to the mirroring group which exhibited a mean error of 1.13 mm. Reconstructions of bilateral defects yielded only slightly higher estimation errors than those of unilateral defects. The presented computer-based approach using SSM is a precise and simple tool in the field of computer-assisted surgery. It helps to reconstruct large-size defects of the skull considering the natural asymmetry of the cranium and is not limited to unilateral defects.

Clinical outcome after high-precision radiotherapy for skull base meningiomas: Pooled data from three large German centers for radiation oncology.

PubMed

Combs, Stephanie E; Farzin, Mostafa; Boehmer, Julia; Oehlke, Oliver; Molls, Michael; Debus, Jürgen; Grosu, Anca-Ligia

2018-05-01

To evaluate outcome in patients with base of skull meningiomas treated with modern high precision radiation therapy (RT) techniques. 927 patients from three centers were treated with either radiosurgery or fractionated high-precision RT for meningiomas. Treatment planning was based on CT and MRI following institutional guidelines. For radiosurgery, a median dose of 13 Gy was applied, for fractionated treatments, a median dose of 54 Gy in 1.8 Gy single fractions was prescribed. Follow-up included a clinical examination as well as contrast-enhanced imaging. All patients were followed up prospectively after radiotherapy in the three departments within a strict follow-up regimen. The median follow-up time was 81 months (range 1-348 months). Median local control was 79 months (range 1-348 months). Local control (LC) was 98% at 1 year, 94% at 3 years, 92% at 5 years and 86% at 10 years. There was no difference between radiosurgery and fractionated RT. We analyzed the influence of higher doses on LC and could show that dose did not impact LC. Moreover, there was no difference between 54 Gy and 57.6 Gy in the fractionated group. Side effects were below 5% in both groups without any severe treatment-related complications. Based on the pooled data analysis this manuscript provides a large series of meningiomas of the skull base treated with modern high precision RT demonstrating excellent local control and low rates of side effects. Such data support the recommendation of RT for skull base meningiomas in the interdisciplinary tumor board discussions. The strong role of RT must influence treatment recommendations keeping in mind the individual risk-benefit profile of treatment alternatives. Copyright © 2018 Elsevier B.V. All rights reserved.

Malignant external otitis: The diagnostic value of bone scintigraphy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostfeld, E.; Aviel, A.; Pelet, D.

1981-06-01

Technetium99m Methylene Diphosphate bone scintigraphy (BS) of the skull was performed in three patients with malignant external otitis (MEO). Pathological uptake of the radioisotope in the mastoid region was found during the early stages of MEO updating radiologic findings. The extent of the radioisotope accumulation during the early stages of MEO indicates that the actual tissue damage exceeds the clinical estimation. The follow-up BS findings correlate well with the clinical course of MEO indicating either healing or extension to the base of skull.

A Brain-Machine-Brain Interface for Rewiring of Cortical Circuitry after Traumatic Brain Injury

DTIC Science & Technology

2011-09-01

parietal bones, and a threaded rod was implanted into the interparietal bone. These were affixed to the skull with dental acrylic. A hybrid, 16...then sealed with a silicone polymer (Kwik-Cast, WPI). The base of the probe connector was lowered onto the dental acrylic and fixed into place. An...the skull using a dental drill with a trephine bit over the cortex contralateral to the dominant forelimb. A total of 14 animals received CCI in the

Clinical anatomy and imaging of the cranial nerves and skull base.

PubMed

Jha, Ruchira M; Klein, Joshua P

2012-09-01

Evaluation of patients with cranial neuropathies requires an understanding of brainstem anatomy and nerve pathways. Advances in neuroimaging, particularly high spatial resolution magnetic resonance imaging (MRI), have enabled visualization of these tiny structures and their related pathology. This review provides an approach toward using imaging in the evaluation of cranial nerve (CN) and skull base anatomy and pathology. Because brainstem nuclei are inextricably linked to the information contained within CNs, they are briefly mentioned whenever relevant; however, a comprehensive discussion of brainstem syndromes is beyond the scope of this review. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Olfaction in Endoscopic Sinus and Skull Base Surgery.

PubMed

Thompson, Christopher F; Kern, Robert C; Conley, David B

2015-10-01

Olfactory dysfunction is a common complaint for patients with chronic rhinosinusitis, because smell loss decreases a patient's quality of life. Smell loss is caused by obstruction from polyps, nasal discharge, and mucosal edema, as well as inflammatory changes within the olfactory epithelium. Addressing olfaction before endoscopic sinus and skull base surgery is important in order to set postoperative expectations, because an improvement in smell is difficult to predict. Several commercially available olfactory testing measures are available and can easily be administered in clinic. During surgery, careful dissection within the olfactory cleft is recommended in order to optimize postoperative olfactory function. Copyright © 2015 Elsevier Inc. All rights reserved.

Management of Major Vascular Injury During Endoscopic Endonasal Skull Base Surgery.

PubMed

Gardner, Paul A; Snyderman, Carl H; Fernandez-Miranda, Juan C; Jankowitz, Brian T

2016-06-01

A major vascular injury is the most feared complication of endoscopic sinus and skull base surgery. Risk factors for vascular injury are discussed, and an algorithm for management of a major vascular injury is presented. A team of surgeons (otolaryngology and neurosurgery) is important for identification and control of a major vascular injury applying basic principles of vascular control. A variety of techniques can be used to control a major injury, including coagulation, a muscle patch, sacrifice of the artery, and angiographic stenting. Immediate and close angiographic follow-up is critical to prevent and manage subsequent complications of vascular injury. Copyright © 2016 Elsevier Inc. All rights reserved.

Application of Ultrasonic Bone Curette in Endoscopic Endonasal Skull Base Surgery: Technical Note

PubMed Central

Rastelli, Milton M.; Pinheiro-Neto, Carlos D.; Fernandez-Miranda, Juan C.; Wang, Eric W.; Snyderman, Carl H.; Gardner, Paul A.

2014-01-01

Background Endoscopic endonasal surgery (EES) of the skull base often requires extensive bone work in proximity to critical neurovascular structures. Objective To demonstrate the application of an ultrasonic bone curette during EES. Methods Ten patients with skull base lesions underwent EES from September 2011 to April 2012 at the University of Pittsburgh Medical Center. Most of the bone work was done with high-speed drill and rongeurs. The ultrasonic curette was used to remove specific structures. Results All the patients were submitted to fully endoscopic endonasal procedures and had critical bony structures removed with the ultrasonic bone curette. Two patients with degenerative spine diseases underwent odontoid process removal. Five patients with clival and petroclival tumors underwent posterior clinoid removal. Two patients with anterior fossa tumors underwent crista galli removal. One patient underwent unilateral optic nerve decompression. No mechanical or heat injury resulted from the ultrasonic curette. The surrounding neurovascular structures and soft tissue were preserved in all cases. Conclusion In selected EES, the ultrasonic bone curette was successfully used to remove loose pieces of bone in narrow corridors, adjacent to neurovascular structures, and it has advantages to high-speed drills in these specific situations. PMID:24719795

Scarless abdominal fat graft harvest for neurosurgical procedures: technical note.

PubMed

Trinh, Victoria T; Duckworth, Edward A M

2015-02-01

Background Abdominal fat grafts are often harvested for use in skull base reconstruction and cerebrospinal fluid (CSF) leak repairs, and for operations traversing the nasal sinuses or mastoid bone. Although the endoscopic transnasal surgery has gained significant popularity, in part because it is considered "scarless," a common adjunct, the abdominal fat graft, can result in a disfiguring scar across the abdomen. Objective This is the first report of a scarless abdominal fat graft technique for skull base reconstruction. Methods Ten patients with a median age of 56.5 years (range: 45-73 years) underwent endoscopic transsphenoidal tumor resection with intraumbilical fat graft harvest. Careful circumferential fat dissection at the umbilicus, with progressive retraction of the graft, was crucial to ensure maximal visualization and to prevent injury to the subcutaneous vessels and rectus fascia. Results Following reconstruction of the sellar skull base, all patients did well postoperatively with no evidence of CSF leak. At 12-week follow-up for all patients, there was no evidence of scar, intracavity hematoma, or wound infection. Conclusions Fat graft harvest through an intraumbilical incision results in a scar-free abdominal harvest, and is a useful procedural adjunct to complement "scarless" brain surgery.

A forward-adjoint operator pair based on the elastic wave equation for use in transcranial photoacoustic computed tomography

PubMed Central

Mitsuhashi, Kenji; Poudel, Joemini; Matthews, Thomas P.; Garcia-Uribe, Alejandro; Wang, Lihong V.; Anastasio, Mark A.

2017-01-01

Photoacoustic computed tomography (PACT) is an emerging imaging modality that exploits optical contrast and ultrasonic detection principles to form images of the photoacoustically induced initial pressure distribution within tissue. The PACT reconstruction problem corresponds to an inverse source problem in which the initial pressure distribution is recovered from measurements of the radiated wavefield. A major challenge in transcranial PACT brain imaging is compensation for aberrations in the measured data due to the presence of the skull. Ultrasonic waves undergo absorption, scattering and longitudinal-to-shear wave mode conversion as they propagate through the skull. To properly account for these effects, a wave-equation-based inversion method should be employed that can model the heterogeneous elastic properties of the skull. In this work, a forward model based on a finite-difference time-domain discretization of the three-dimensional elastic wave equation is established and a procedure for computing the corresponding adjoint of the forward operator is presented. Massively parallel implementations of these operators employing multiple graphics processing units (GPUs) are also developed. The developed numerical framework is validated and investigated in computer19 simulation and experimental phantom studies whose designs are motivated by transcranial PACT applications. PMID:29387291

Thermal model to investigate the temperature in bone grinding for skull base neurosurgery.

PubMed

Zhang, Lihui; Tai, Bruce L; Wang, Guangjun; Zhang, Kuibang; Sullivan, Stephen; Shih, Albert J

2013-10-01

This study develops a thermal model utilizing the inverse heat transfer method (IHTM) to investigate the bone grinding temperature created by a spherical diamond tool used for skull base neurosurgery. Bone grinding is a critical procedure in the expanded endonasal approach to remove the cranial bone and access to the skull base tumor via nasal corridor. The heat is generated during grinding and could damage the nerve or coagulate the blood in the carotid artery adjacent to the bone. The finite element analysis is adopted to investigate the grinding-induced bone temperature rise. The heat source distribution is defined by the thermal model, and the temperature distribution is solved using the IHTM with experimental inputs. Grinding experiments were conducted on a bovine cortical bone with embedded thermocouples. Results show significant temperature rise in bone grinding. Using 50°C as the threshold, the thermal injury can propagate about 3mm in the traverse direction, and 3mm below the ground surface under the dry grinding condition. The presented methodology demonstrated the capability of being a thermal analysis tool for bone grinding study. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

Endoscopic endonasal approach for the treatment of anterior skull base tumours.

PubMed

López, Fernando; Suárez, Vanessa; Costales, María; Rodrigo, Juan P; Suárez, Carlos; Llorente, José Luis

2012-01-01

The increasing expertise of transnasal endoscopic surgery has recently expanded its indications to include the management of tumours affecting the skull base. We report our experience with endoscopic management of these tumours, emphasising the indications and surgical technique used. A retrospective analysis was performed of patients treated by an endoscopic endonasal approach (EEA) in our department from 2004 until 2011. Sixty-three patients were analysed. We performed an endoscopic craniofacial resection in 32 patients (51%), an expanded EEA in 22 (35%), a transclival approach in 6 (9%) and a transpterygoid approach in 3 (5%). The most frequent benign tumour was nasopharyngeal angiofibroma (24%), while adenocarcinoma (30%) was the most common among malignancies. Mean follow-up was 26 months (range: 6 to 84 months). The complication rate was 5% and resection was complete in 56 cases (89%). The 5-year overall-survival was 71% in patients with malignant tumours and the effectiveness was 100% in benign tumours. Our results support that endoscopic surgery, when properly planned, represents a valid alternative to standard surgical approaches for the management of skull base tumours. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Covered Stent-Graft Treatment of Traumatic Internal Carotid Artery Pseudoaneurysms: A Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maras, Dimitrios; Lioupis, Christos; Magoufis, George

Objective. To review the literature concerning the management with placement of covered stent-grafts of traumatic pseudoaneurysms of the extracranial internal carotid artery (ICA) resulting from penetrating craniocervical injuries or skull base fractures. Method. We have reviewed, from the Medline database, all the published cases in the English literature since 1990 and we have added a new case. Results. We identified 20 patients with traumatic extracranial ICA pseudoaneurysms due to penetrating craniocervical injuries or skull base fractures who had been treated with covered stent-graft implantation. Many discrepancies have been ascertained regarding the anticoagulation therapy. In 3 patients the ICA was totallymore » occluded in the follow-up period, giving an overall occlusion rate 15%. No serious complication was reported as a result of the endovascular procedure. Conclusion. Preliminary results suggest that placement of stent-grafts is a safe and effective method of treating ICA traumatic pseudoaneurysms resulting from penetrating craniocervical injuries or skull base fractures. The immediate results are satisfactory when the procedure takes place with appropriate anticoagulation therapy. The periprocedural morbidity and mortality and the early patency are also acceptable. A surveillance program with appropriate interventions to manage restenosis may improve the long-term patency.« less

Skulls and Human Evolution: The Use of Casts of Anthropoid Skulls in Teaching Concepts of Human Evolution.

ERIC Educational Resources Information Center

Gipps, John

1991-01-01

Proposes the use of a series of 11 casts of fossil skulls as a method of teaching about the theory of human evolution. Students explore the questions of which skulls are "human" and which came first in Homo Sapien development, large brain or upright stance. (MDH)

Geologic map of the Skull Creek Quadrangle, Moffat County Colorado

USGS Publications Warehouse

Van Loenen, R. E.; Selner, Gary; Bryant, W.A.

1999-01-01

The Skull Creek quadrangle is in northwestern Colorado a few miles north of Rangely. The prominent structural feature of the Skull Creek quadrangle is the Skull Creek monocline. Pennsylvanian rocks are exposed along the axis of the monocline while hogbacks along its southern flank expose rocks that are from Permian to Upper Cretaceous in age. The Wolf Creek monocline and the Wolf Creek thrust fault, which dissects the monocline, are salient structural features in the northern part of the quadrangle. Little or no mineral potential exists within the quadrangle. A geologic map of the Lazy Y Point quadrangle, which is adjacent to the Skull Creek quadrangle on the west, is also available (Geologic Investigations Series I-2646). This companian map shows similar geologic features, including the western half of the Skull Creek monocline. The geology of this quadrangle was mapped because of its proximity to Dinosaur National Monument. It is adjacent to quadrangles previously mapped to display the geology of this very scenic and popular National Monument. The Skull Creek quadrangle includes parts of the Skull Creek Wilderness Study Area, which was assessed for its mineral resource potential.

Study of Mastoid Canals and Grooves in North Karnataka Human Skulls

PubMed Central

Hadimani, Gavishiddappa Andanappa; Bagoji, Ishwar Basavantappa

2013-01-01

Introduction: This study was undertaken to observe the frequency of mastoid canals and grooves in north Karnataka dry human skulls. 100 dry human skulls of unknown age and sex from the department of Anatomy were selected and observed for the present study. Material and Methods: The mastoid regions of dry skulls were observed for the presence of mastoid canals and grooves, if any. A metallic wire was passed through the canal for its confirmation and then the length was measured. Results: The Mastoid canals were present in 53% of the total 100 skulls observed either bilaterally or unilaterally. Mastoid grooves were present in 18% of the total skulls (100) observed. Double mastoid canal was found in 01% of total skull studied and both Mastoid canals & Mastoid grooves together were present in 02% of the total skulls (100) observed. Conclusion: The knowledge of mastoid canals and grooves is very important for otolaryngologists and neurosurgeons. Because they contain an arterial branch of occipital artery with its accompanying vein which is liable to injury resulting into severe bleeding. PMID:24086832

Trans-skull ultrasonic Doppler system aided by fuzzy logic

NASA Astrophysics Data System (ADS)

Hata, Yutaka; Nakamura, Masato; Yagi, Naomi; Ishikawa, Tomomoto

2012-06-01

This paper describes a trans-skull ultrasonic Doppler system for measuring the blood flow direction in brain under skull. In this system, we use an ultrasonic array probe with the center frequency of 1.0 MHz. The system determines the fuzzy degree of blood flow by Doppler Effect, thereby it locates blood vessel. This Doppler Effect is examined by the center of gravity shift of the frequency magnitudes. In in-vitro experiment, a cow bone was employed as the skull, and three silicon tubes were done as blood vessels, and bubble in water as blood. We received the ultrasonic waves through a protein, the skull and silicon tubes in order. In the system, fuzzy degrees are determined with respect to the Doppler shift, amplitude of the waves and attenuation of the tissues. The fuzzy degrees of bone and blood direction are calculated by them. The experimental results showed that the system successfully visualized the skull and flow direction, compared with the location and flow direction of the phantom. Thus, it detected the flow direction by Doppler Effect under skull, and automatically extracted the region of skull and blood vessel.

The ontogenetic origins of skull shape disparity in the Triturus cristatus group.

PubMed

Cvijanović, Milena; Ivanović, Ana; Kalezić, Miloš L; Zelditch, Miriam L

2014-09-01

Comparative studies of ontogenies of closely related species provide insights into the mechanisms responsible for morphological diversification. Using geometric morphometrics, we investigated the ontogenetic dynamics of postlarval skull shape and disparity in three closely related crested newt species. The skull shapes of juveniles just after metamorphosis (hereafter metamorphs) and adult individuals were sampled by landmark configurations that describe the shape of the dorsal and ventral side of the newt skull, and analyzed separately. The three species differ in skull size and shape in metamorphs and adults. The ontogenies of dorsal and ventral skull differ in the orientation but not lengths of the ontogenetic trajectories. The disparity of dorsal skull shape increases over ontogeny, but that of ventral skull shape does not. Thus, modifications of ontogenetic trajectories can, but need not, increase the disparity of shape. In species with biphasic life-cycles, when ontogenetic trajectories for one stage can be decoupled from those of another, increases and decreases in disparity are feasible, but our results show that they need not occur. © 2014 Wiley Periodicals, Inc.

Management of Dropped Skull Flaps.

PubMed

Abdelfatah, Mohamed AbdelRahman

2017-01-01

Dropping a skull flap on the floor is an uncommon and avoidable mistake in the neurosurgical operating theater. This study retrospectively reviewed all incidents of dropped skull flaps in Ain-Shams University hospitals during a 10-year period to show how to manage this problem and its outcome. Thirty-one incidents of dropped skull flaps occurred from January 2004 to January 2014 out of more than 10,000 craniotomies. Follow-up period varied from 20 to 44 months. The bone flap was dropped while elevating the bone (n = 16), while drilling the bone on the operating table (n = 5), and during insertion of the bone flap (n = 10). Treatment included re-insertion of the skull flap after soaking it in povidone iodine and antibiotic solution (n = 17) or after autoclaving (n = 11), or discarding the skull flap and replacing it with a mesh cranioplasty in the same operation (n = 3). No bone or wound infection was noted during the follow-up period. Management of dropped skull flap is its prevention. Replacement of the skull flap, after decontamination, is an option that avoids the expense and time of cranioplasty.

The Relationship of Three-Dimensional Human Skull Motion to Brain Tissue Deformation in Magnetic Resonance Elastography Studies.

PubMed

Badachhape, Andrew A; Okamoto, Ruth J; Durham, Ramona S; Efron, Brent D; Nadell, Sam J; Johnson, Curtis L; Bayly, Philip V

2017-05-01

In traumatic brain injury (TBI), membranes such as the dura mater, arachnoid mater, and pia mater play a vital role in transmitting motion from the skull to brain tissue. Magnetic resonance elastography (MRE) is an imaging technique developed for noninvasive estimation of soft tissue material parameters. In MRE, dynamic deformation of brain tissue is induced by skull vibrations during magnetic resonance imaging (MRI); however, skull motion and its mode of transmission to the brain remain largely uncharacterized. In this study, displacements of points in the skull, reconstructed using data from an array of MRI-safe accelerometers, were compared to displacements of neighboring material points in brain tissue, estimated from MRE measurements. Comparison of the relative amplitudes, directions, and temporal phases of harmonic motion in the skulls and brains of six human subjects shows that the skull-brain interface significantly attenuates and delays transmission of motion from skull to brain. In contrast, in a cylindrical gelatin "phantom," displacements of the rigid case (reconstructed from accelerometer data) were transmitted to the gelatin inside (estimated from MRE data) with little attenuation or phase lag. This quantitative characterization of the skull-brain interface will be valuable in the parameterization and validation of computer models of TBI.

Paleopathological findings in radiographs of ancient and modern Greek skulls.

PubMed

Papagrigorakis, Manolis J; Karamesinis, Kostas G; Daliouris, Kostas P; Kousoulis, Antonis A; Synodinos, Philippos N; Hatziantoniou, Michail D

2012-12-01

The skull, when portrayed radiologically, can be a useful tool in detecting signs of systemic diseases and results of pathological growth mechanisms. The aim of this study was therefore to examine, compare, and classify findings in cranial configuration of pathological origin, in modern and ancient skulls. The material consists of 240 modern and 141 ancient dry skulls. Three radiographs for each skull (lateral, anteroposterior, basilar) provide enough evidence for differential diagnoses. Cases of osteoporosis are among the interesting pathological findings. A prevalence of female modern skulls in those determined as osteoporotic skulls is noted. Special interest is placed on the area of the sella turcica and many variations, regarding the shape and texture, are recognized both in ancient and modern skulls. Malignancies and important causes of cranial destruction are identified in both skull collections. Diploid thickening and osteolytic areas appear commonly among ancient remains. Moreover, from the ancient skull collection, one case possibly recognizable as fibrous dysplasia is noted while another case with an unusual exostosis gives rise to many questions. Interpreted with caution, the results of the present study, which can serve as an approach of paleopathology and paleoradiology, indicate similarity trends in cranial configuration of pathologic origin in modern and ancient people. Radiography and cephalometry were the main diagnostic tools used to gather evidence and are evaluated as a quite appropriate method to examine anthropological material and assess the internal structure of skeletal remains since they are non-destructive techniques.

Juvenile psammomatoid ossifying fibroma in paranasal sinus and skull base.

PubMed

Wang, Mingjie; Zhou, Bing; Cui, Shunjiu; Li, Yunchuan

2017-07-01

The endoscopic transnasal approach with IGS is a safe and effective technique, allowing completely resection of JPOF, with minimal morbidity and recurrence. JPOF is a benign but locally aggressive fibro-osseous lesion. This study presents a series of JPOF cases, involving anterior skull base and orbit, treated by endoscopic transnasal approach with image guidance system (IGS) to resect the mass completely. This study retrospectively reviewed the clinical presentations, surgical procedures, and complications of 11 patients with JPOF who were treated by endoscopic approach from May 2009 to April 2014. All patients were followed by endoscopic and CT scan evaluations during follow-up. All of the 11 cases were boys, with a mean age of 11.8 years (range = 6-17 years). The size of mass in the paranasal sinus ranged from 2.5-4.6 cm in greatest dimension (mean = 3.7 cm), and the medial orbital wall and cranial base were involved in all patients. All 11 patients received successful operation and were relieved from symptoms without mortality and major complications. During follow-up (range from 17-67 months; mean follow-up = 25.8 months), only one patient was recurrent in local position. The skull base partial resected during surgery was found to rebuild after 1 year.

Cerebrospinal fluid leakage and Chiari I malformation with Gorham's disease of the skull base: A case report.

PubMed

Nagashima, Hiroaki; Mizukawa, Katsu; Taniguchi, Masaaki; Yamamoto, Yusuke; Kohmura, Eiji

Gorham's syndrome is a rare bone disorder characterized by massive osteolysis of unknown etiology. There are no reports of comorbidity involving cerebrospinal fluid (CSF) leakage and Chiari I malformation with Gorham's syndrome. Here, we report an unusual case of an acute presyrinx state complicated by bacterial meningitis due to CSF leakage and Chiari I malformation associated with Gorham's disease of the skull base. A 25-year-old woman with Chiari I malformation associated with Gorham's syndrome presented with aggressive paresthesia following bacterial meningitis. Axial magnetic resonance imaging (MRI) and computed tomography (CT) cisternography revealed CSF leakage in the right petrous apex. A presyrinx state was diagnosed based on the clinical symptoms and MRI findings. With resolution of the bacterial meningitis, the spinal edema and tonsillar ectopia also improved. Surgical repair of the CSF leakage was performed by an endoscopic endonasal transsphenoidal approach to prevent recurrence of meningitis. The postoperative course was uneventful. Skull base osteolysis in Gorham's syndrome may induce Chiari I malformation and CSF leakage. We should pay attention to acute progression of clinical symptoms because Gorham's syndrome may predispose to development of Chiari I malformation and may be complicated by CSF leakage. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Vestibular evoked myogenic potentials in response to lateral skull taps are dependent on two different mechanisms.

PubMed

Brantberg, Krister; Westin, Magnus; Löfqvist, Lennart; Verrecchia, Luca; Tribukait, Arne

2009-05-01

To explore the mechanisms for skull tap induced vestibular evoked myogenic potentials (VEMP). The muscular responses were recorded over both sternocleidomastoid (SCM) muscles using skin electrodes. A skull tapper which provided a constant stimulus intensity was used to test cervical vestibular evoked myogenic potentials (VEMP) in response to lateral skull taps in healthy subjects (n=10) and in patients with severe unilateral loss of vestibular function (n=10). Skull taps applied approximately 2 cm above the outer ear canal caused highly reproducible VEMP. There were differences in VEMP in both normals and patients depending on side of tapping. In normals, there was a positive-negative ("normal") VEMP on the side contra-lateral to the skull tapping, but no significant VEMP ipsi-laterally. In patients, skull taps above the lesioned ear caused a contra-lateral positive-negative VEMP (as it did in the normals), in addition there was an ipsi-lateral negative-positive ("inverted") VEMP. When skull taps were presented above the healthy ear there was only a small contra-lateral positive-negative VEMP but, similar to the normals, no VEMP ipsi-laterally. The present data, in conjunction with earlier findings, support a theory that skull-tap VEMP responses are mediated by two different mechanisms. It is suggested that skull tapping causes both a purely ipsi-lateral stimulus side independent SCM response and a bilateral and of opposite polarity SCM response that is stimulus side dependent. Possibly, the skull tap induced VEMP responses are the sum of a stimulation of two species of vestibular receptors, one excited by vibration (which is rather stimulus site independent) and one excited by translation (which is more stimulus site dependent). Skull-tap VEMP probably have two different mechanisms. Separation of the two components might reveal the status of different labyrinthine functions.

On the integral use of foundational concepts in verifying validity during skull-photo superimposition.

PubMed

Jayaprakash, Paul T

2017-09-01

Often cited reliability test on video superimposition method integrated scaling face-images in relation to skull-images, tragus-auditory meatus relationship in addition to exocanthion-Whitnall's tubercle relationship when orientating the skull-image and wipe mode imaging in addition to mix mode imaging when obtaining skull-face image overlay and evaluating the goodness of match. However, a report that found higher false positive matches in computer assisted superimposition method transited from the above foundational concepts and relied on images of unspecified sizes that are lesser than 'life-size', frontal plane landmarks in the skull- and face- images alone for orientating the skull-image and mix images alone for evaluating the goodness of match. Recently, arguing the use of 'life-size' images as 'archaic', the authors who tested the reliability in the computer assisted superimposition method have denied any method transition. This article describes that the use of images of unspecified sizes at lesser than 'life-size' eliminates the only possibility to quantify parameters during superimposition which alone enables dynamic skull orientation when overlaying a skull-image with a face-image in an anatomically acceptable orientation. The dynamic skull orientation process mandatorily requires aligning the tragus in the 2D face-image with the auditory meatus in the 3D skull-image for anatomically orientating the skull-image in relation to the posture in the face-image, a step not mentioned by the authors describing the computer assisted superimposition method. Furthermore, mere reliance on mix type images during image overlay eliminates the possibility to assess the relationship between the leading edges of the skull- and face-image outlines as also specific area match among the corresponding craniofacial organs during superimposition. Indicating the possibility of increased false positive matches as a consequence of the above method transitions, the need for testing the reliability in the superimposition method adopting concepts that are considered safe is stressed. Copyright © 2017 Elsevier B.V. All rights reserved.

A Telerobotic System for Transnasal Surgery

PubMed Central

Burgner, Jessica; Rucker, D. Caleb; Gilbert, Hunter B.; Swaney, Philip J.; Russell, Paul T.; Weaver, Kyle D.; Webster, Robert J.

2014-01-01

Mechanics-based models of concentric tube continuum robots have recently achieved a level of sophistication that makes it possible to begin to apply these robots to a variety of real-world clinical scenarios. Endonasal skull base surgery is one such application, where their small diameter and tentacle like dexterity are particularly advantageous. In this paper we provide the medical motivation for an endonasal surgical robot featuring concentric tube manipulators, and describe our model-based design and teleoperation methods, as well as a complete system incorporating image-guidance. Experimental demonstrations using a laparoscopic training task, a cadaver reachability study, and a phantom tumor resection experiment illustrate that both novice and expert users can effectively teleoperate the system, and that skull base surgeons can use the robot to achieve their objectives in a realistic surgical scenario. PMID:25089086

Non-Invasive Method of Determining Absolute Intracranial Pressure

NASA Technical Reports Server (NTRS)

Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor); Hargens, Alan E. (Inventor)

2004-01-01

A method is presented for determining absolute intracranial pressure (ICP) in a patient. Skull expansion is monitored while changes in ICP are induced. The patient's blood pressure is measured when skull expansion is approximately zero. The measured blood pressure is indicative of a reference ICP value. Subsequently, the method causes a known change in ICP and measured the change in skull expansion associated therewith. The absolute ICP is a function of the reference ICP value, the known change in ICP and its associated change in skull expansion; and a measured change in skull expansion.

Simultaneous skull-stripping and lateral ventricle segmentation via fast multi-atlas likelihood fusion

NASA Astrophysics Data System (ADS)

Tang, Xiaoying; Kutten, Kwame; Ceritoglu, Can; Mori, Susumu; Miller, Michael I.

2015-03-01

In this paper, we propose and validate a fully automated pipeline for simultaneous skull-stripping and lateral ventricle segmentation using T1-weighted images. The pipeline is built upon a segmentation algorithm entitled fast multi-atlas likelihood-fusion (MALF) which utilizes multiple T1 atlases that have been pre-segmented into six whole-brain labels - the gray matter, the white matter, the cerebrospinal fluid, the lateral ventricles, the skull, and the background of the entire image. This algorithm, MALF, was designed for estimating brain anatomical structures in the framework of coordinate changes via large diffeomorphisms. In the proposed pipeline, we use a variant of MALF to estimate those six whole-brain labels in the test T1-weighted image. The three tissue labels (gray matter, white matter, and cerebrospinal fluid) and the lateral ventricles are then grouped together to form a binary brain mask to which we apply morphological smoothing so as to create the final mask for brain extraction. For computational purposes, all input images to MALF are down-sampled by a factor of two. In addition, small deformations are used for the changes of coordinates. This substantially reduces the computational complexity, hence we use the term "fast MALF". The skull-stripping performance is qualitatively evaluated on a total of 486 brain scans from a longitudinal study on Alzheimer dementia. Quantitative error analysis is carried out on 36 scans for evaluating the accuracy of the pipeline in segmenting the lateral ventricle. The volumes of the automated lateral ventricle segmentations, obtained from the proposed pipeline, are compared across three different clinical groups. The ventricle volumes from our pipeline are found to be sensitive to the diagnosis.