scholarly journals Predicting and comparing three corrective techniques for sagittal craniosynostosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Connor Cross ◽  
Roman H. Khonsari ◽  
Dawid Larysz ◽  
David Johnson ◽  
Lars Kölby ◽  
...  
Keyword(s):  
Finite Element ◽  
Surgical Techniques ◽  
Morphological Characteristics ◽  
Neurocognitive Deficits ◽  
Sagittal Synostosis ◽  
Sagittal Craniosynostosis ◽  
Reconstruction Methods ◽  
The Impact ◽  
The Brain

AbstractSagittal synostosis is the most occurring form of craniosynostosis, resulting in calvarial deformation and possible long-term neurocognitive deficits. Several surgical techniques have been developed to correct these issues. Debates as to the most optimal approach are still ongoing. Finite element method is a computational tool that’s shown to assist with the management of craniosynostosis. The aim of this study was to compare and predict the outcomes of three reconstruction methods for sagittal craniosynostosis. Here, a generic finite element model was developed based on a patient at 4 months of age and was virtually reconstructed under all three different techniques. Calvarial growth was simulated to predict the skull morphology and the impact of different reconstruction techniques on the brain growth up to 60 months of age. Predicted morphology was then compared with in vivo and literature data. Our results show a promising resemblance to morphological outcomes at follow up. Morphological characteristics between considered techniques were also captured in our predictions. Pressure outcomes across the brain highlight the potential impact that different techniques have on growth. This study lays the foundation for further investigation into additional reconstructive techniques for sagittal synostosis with the long-term vision of optimizing the management of craniosynostosis.

scholarly journals A Long-Term Fine-Resolution Record of AVHRR Surface Temperatures for the Laurentian Great Lakes

2018 ◽  
Vol 10 (8) ◽  
pp. 1210
Author(s):  
Charles White ◽  
Andrew Heidinger ◽  
Steven Ackerman ◽  
Peter McIntyre
Keyword(s):  
Great Lakes ◽  
Morphological Characteristics ◽  
Laurentian Great Lakes ◽  
Environmental Research ◽  
Weighted Interpolation ◽  
Large Lakes ◽  
Fine Resolution ◽  
Observation Times ◽  
The Impact

Inland waters are warming at highly variable rates that often differ from regional air temperature trends. This variable warming is partially attributable to an individual lake’s geographical and morphological characteristics. In very large lakes, significant intralake variability in long-term warming trends has also been observed. In light of this intralake and interlake heterogeneity of lake surface water temperature (LSWT) and LSWT trends, we revisit the 1.1 km Advanced Very High Resolution Radiometer (AVHRR) record for the Laurentian Great Lakes. In this work, we have assembled a long-term (1986–2016) and high-spatial-resolution (0.018°) daily LSWT dataset using AVHRR record. Subtracting an empirically-determined mean diurnal cycle mitigates the effects of varying observation times. Adjustments in the georegistration of the images are made to reduce the impact of AVHRR navigational errors on the earlier platforms. Both the original daily composites, and a gap-filled product using locally weighted interpolation methods will be made available to support fine-scale physical and environmental research in the region.

scholarly journals BMI Specific Complications Following Implant-Based Breast Reconstruction after Mastectomy

2021 ◽  
Vol 10 (23) ◽  
pp. 5665
Author(s):  
Helena Sophie Leitner ◽  
Reinhard Pauzenberger ◽  
Ines Ana Ederer ◽  
Christine Radtke ◽  
Stefan Hacker
Keyword(s):  
Postoperative Complications ◽  
Breast Reconstruction ◽  
Positive Impact ◽  
Surgical Techniques ◽  
Study Cohort ◽  
Complication Rates ◽  
Impaired Wound Healing ◽  
Reconstruction Methods ◽  
Study Results ◽  
The Impact

Background: Breast reconstruction has a positive impact on body image and quality of life for women after experiencing the physically and psychologically demanding process of mastectomy. Previous studies have presented body mass index (BMI) as a predictor for postoperative complications after breast reconstruction, however, study results vary. This retrospective study aimed to investigate the impact of patients’ BMI on postoperative complications following implant-based breast reconstruction. Methods: All implant-based breast reconstructions performed at the Department of Plastic, Reconstructive and Aesthetic Surgery at the Medical University of Vienna from January 2001 to March 2018 were evaluated. A total of 196 reconstructed breasts among 134 patients met eligibility criteria. Demographic data, surgical techniques, as well as major and minor complications within a one-year follow-up period were analyzed. Results: Patients’ BMI did not show a significant impact on complication rates. The overall incidence of postoperative complications was 30.5% (40/131) of which 17.6% required reoperation. Impaired wound healing (18.3%), seroma (6.1%), hematoma (4.6%), capsular contraction (4.6%) and infection (3.8%) were the most common complications. Conclusion: In our study cohort, BMI was not associated with a significantly higher risk of complications. However, postoperative complications significantly increased with a longer operative time and resulted in an extended length of hospital stay.

scholarly journals The Causes and Long-Term Consequences of Viral Encephalitis

2021 ◽  
Vol 15 ◽  
Author(s):  
Karen Bohmwald ◽  
Catalina A. Andrade ◽  
Nicolás M. S. Gálvez ◽  
Valentina P. Mora ◽  
José T. Muñoz ◽  
...  
Keyword(s):  
Viral Encephalitis ◽  
Viral Infections ◽  
Immune Cell ◽  
Clinical Symptoms ◽  
Brain Inflammation ◽  
High Morbidity ◽  
Stiff Neck ◽  
The Impact ◽  
The Brain

Reports regarding brain inflammation, known as encephalitis, have shown an increasing frequency during the past years. Encephalitis is a relevant concern to public health due to its high morbidity and mortality. Infectious or autoimmune diseases are the most common cause of encephalitis. The clinical symptoms of this pathology can vary depending on the brain zone affected, with mild ones such as fever, headache, confusion, and stiff neck, or severe ones, such as seizures, weakness, hallucinations, and coma, among others. Encephalitis can affect individuals of all ages, but it is frequently observed in pediatric and elderly populations, and the most common causes are viral infections. Several viral agents have been described to induce encephalitis, such as arboviruses, rhabdoviruses, enteroviruses, herpesviruses, retroviruses, orthomyxoviruses, orthopneumovirus, and coronaviruses, among others. Once a neurotropic virus reaches the brain parenchyma, the resident cells such as neurons, astrocytes, and microglia, can be infected, promoting the secretion of pro-inflammatory molecules and the subsequent immune cell infiltration that leads to brain damage. After resolving the viral infection, the local immune response can remain active, contributing to long-term neuropsychiatric disorders, neurocognitive impairment, and degenerative diseases. In this article, we will discuss how viruses can reach the brain, the impact of viral encephalitis on brain function, and we will focus especially on the neurocognitive sequelae reported even after viral clearance.

Investigation of Stress Wave Propagation in Brain Tissues Through the Use of Finite Element Method

2010 ◽  
Author(s):  
Biaobiao Zhang ◽  
W. Steve Shepard ◽  
Candace L. Floyd
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Brain Injury ◽  
Stress Wave ◽  
Brain Research ◽  
Complex Structure ◽  
Stress Wave Propagation ◽  
Wave Loads ◽  
The Impact ◽  
The Brain

Because axons serve as the conduit for signal transmission within the brain, research related to axon damage during brain injury has received much attention in recent years. Although myelinated axons appear as a uniform white matter, the complex structure of axons has not been thoroughly considered in the study of fundamental structural injury mechanisms. Most axons are surrounded by an insulating sheath of myelin. Furthermore, hollow tube-like microtubules provide a form of structural support as well as a means for transport within the axon. In this work, the effects of microtubule and its surrounding protein mediums inside the axon structure are considered in order to obtain a better understanding of wave propagation within the axon in an attempt to make progress in this area of brain injury modeling. By examining axial wave propagation using a simplified finite element model to represent microtubule and its surrounding proteins assembly, the impact caused by stress wave loads within the brain axon structure can be better understood. Through conducting a transient analysis as the wave propagates, some important characteristics relative to brain tissue injuries are studied.

Keep Your Brain Tissue Healthy

2021 ◽  
pp. 27-66
Author(s):  
Charles Alessi ◽  
Larry W. Chambers ◽  
Muir Gray
Keyword(s):  
Physical Activity ◽  
Immune System ◽  
Inflammatory Response ◽  
Stress Reduction ◽  
Indirect Effects ◽  
Cognitive Abilities ◽  
Direct And Indirect Effects ◽  
The Impact ◽  
The Brain

This chapter starts by advising how to reduce the impact of stress. When stress becomes long term, the immune system becomes less sensitive to cortisol, and since inflammation is partly regulated by this hormone, this decreased sensitivity heightens the inflammatory response and allows inflammation to get out of control, increasing our risk of many diseases. You can reduce your stress yourself through a variety of methods, including physical activity and mindfulness-based stress reduction. Adequate sleep is also a major factor that can improve cognitive abilities and reduce the risk of dementia, and this chapter outlines what we need to know about sleep cycles, insomnia, and sleep disordered breathing, and how to sleep more and sleep better. The chapter then covers how to protect your brain from over medication (polypharmacy). It finishes by discussing how to maintain and indeed increase your levels of physical activity, and how increasing physical activity has both direct and indirect effects on the brain.

scholarly journals Predicting calvarial morphology in sagittal craniosynostosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Oyvind Malde ◽  
Connor Cross ◽  
Chien L. Lim ◽  
Arsalan Marghoub ◽  
Michael L. Cunningham ◽  
...  
Keyword(s):  
Finite Element ◽  
Input Parameter ◽  
Surgical Techniques ◽  
Element Model ◽  
Specific Model ◽  
Patient Specific ◽  
Sagittal Craniosynostosis ◽  
Sensitivity Tests ◽  
Ct Data

AbstractEarly fusion of the sagittal suture is a clinical condition called, sagittal craniosynostosis. Calvarial reconstruction is the most common treatment option for this condition with a range of techniques being developed by different groups. Computer simulations have a huge potential to predict the calvarial growth and optimise the management of this condition. However, these models need to be validated. The aim of this study was to develop a validated patient-specific finite element model of a sagittal craniosynostosis. Here, the finite element method was used to predict the calvarial morphology of a patient based on its preoperative morphology and the planned surgical techniques. A series of sensitivity tests and hypothetical models were carried out and developed to understand the effect of various input parameters on the result. Sensitivity tests highlighted that the models are sensitive to the choice of input parameter. The hypothetical models highlighted the potential of the approach in testing different reconstruction techniques. The patient-specific model highlighted that a comparable pattern of calvarial morphology to the follow up CT data could be obtained. This study forms the foundation for further studies to use the approach described here to optimise the management of sagittal craniosynostosis.

scholarly journals Can a comparison of clinical and deep space irradiation scenarios shed light on the radiation response of the brain?

2020 ◽  
Vol 93 (1115) ◽  
pp. 20200245 ◽  
Author(s):  
Charles Limoli
Keyword(s):  
Occupational Exposures ◽  
Functional Change ◽  
Radiation Environment ◽  
Neurocognitive Deficits ◽  
Deep Space ◽  
Environmental Radiation ◽  
Cellular Targets ◽  
Inhibitory Circuits ◽  
The Impact ◽  
The Brain

Not surprisingly, our knowledge of the impact of radiation on the brain has evolved considerably. Decades of work have struggled with identifying the critical cellular targets in the brain, the latency of functional change and understanding how irradiation alters the balance between excitatory and inhibitory circuits. Radiation-induced cell kill following clinical fractionation paradigms pointed to both stromal and parenchymal targets but also defined an exquisite sensitivity of neurogenic populations of newly born cells in the brain. It became more and more apparent too, that acute (days) events transpiring after exposure were poorly prognostic of the late (months-years) waves of radiation injury believed to underlie neurocognitive deficits. Much of these gaps in knowledge persisted as NASA became interested in how exposure to much different radiation types, doses and dose rates that characterize the space radiation environment might impair central nervous system functionality, with possibly negative implications for deep space travel. Now emerging evidence from researchers engaged in clinical, translational and environmental radiation sciences have begun to fill these gaps and have uncovered some surprising similarities in the response of the brain to seemingly disparate exposure scenarios. This article highlights many of the commonalities between the vastly different irradiation paradigms that distinguish clinical treatments from occupational exposures in deep space.

scholarly journals Neurological, neuropsychiatric and neurodevelopmental complications of COVID-19

2020 ◽  
pp. 000486742096147
Author(s):  
Christos Pantelis ◽  
Mahesh Jayaram ◽  
Anthony J Hannan ◽  
Robb Wesselingh ◽  
Jess Nithianantharajah ◽  
...  
Keyword(s):  
Organ Damage ◽  
Multiple Organ ◽  
Global Pandemic ◽  
Organ Systems ◽  
Future Challenges ◽  
The Central Nervous System ◽  
The Impact ◽  
Collaborative Efforts ◽  
The Brain

Although COVID-19 is predominantly a respiratory disease, it is known to affect multiple organ systems. In this article, we highlight the impact of SARS-CoV-2 (the coronavirus causing COVID-19) on the central nervous system as there is an urgent need to understand the longitudinal impacts of COVID-19 on brain function, behaviour and cognition. Furthermore, we address the possibility of intergenerational impacts of COVID-19 on the brain, potentially via both maternal and paternal routes. Evidence from preclinical models of earlier coronaviruses has shown direct viral infiltration across the blood–brain barrier and indirect secondary effects due to other organ pathology and inflammation. In the most severely ill patients with pneumonia requiring intensive care, there appears to be additional severe inflammatory response and associated thrombophilia with widespread organ damage, including the brain. Maternal viral (and other) infections during pregnancy can affect the offspring, with greater incidence of neurodevelopmental disorders, such as autism, schizophrenia and epilepsy. Available reports suggest possible vertical transmission of SARS-CoV-2, although longitudinal cohort studies of such offspring are needed. The impact of paternal infection on the offspring and intergenerational effects should also be considered. Research targeted at mechanistic insights into all aspects of pathogenesis, including neurological, neuropsychiatric and haematological systems alongside pulmonary pathology, will be critical in informing future therapeutic approaches. With these future challenges in mind, we highlight the importance of national and international collaborative efforts to gather the required clinical and preclinical data to effectively address the possible long-term sequelae of this global pandemic, particularly with respect to the brain and mental health.

scholarly journals The Role of Dietary Antioxidants in the Pathogenesis of Neurodegenerative Diseases and Their Impact on Cerebral Oxidoreductive Balance

Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 435 ◽  
Author(s):  
Anna Winiarska-Mieczan ◽  
Ewa Baranowska-Wójcik ◽  
Małgorzata Kwiecień ◽  
Eugeniusz R. Grela ◽  
Dominik Szwajgier ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Negative Impact ◽  
Functional Disorders ◽  
Brain Functions ◽  
Diet Supplements ◽  
The Impact ◽  
The Brain ◽  
All Diseases

Neurodegenerative diseases are progressive diseases of the nervous system that lead to neuron loss or functional disorders. Neurodegenerative diseases require long-term, sometimes life-long pharmacological treatment, which increases the risk of adverse effects and a negative impact of pharmaceuticals on the patients’ general condition. One of the main problems related to the treatment of this type of condition is the limited ability to deliver drugs to the brain due to their poor solubility, low bioavailability, and the effects of the blood-brain barrier. Given the above, one of the main objectives of contemporary scientific research focuses on the prevention of neurodegenerative diseases. As disorders related to the competence of the antioxidative system are a marker in all diseases of this type, the primary prophylactics should entail the use of exogenous antioxidants, particularly ones that can be used over extended periods, regardless of the patient’s age, and that are easily available, e.g., as part of a diet or as diet supplements. The paper analyzes the significance of the oxidoreductive balance in the pathogenesis of neurodegenerative diseases. Based on information published globally in the last 10 years, an analysis is also provided with regard to the impact of exogenous antioxidants on brain functions with respect to the prevention of this type of diseases.

An Analytical Viscoelastic Model of the Head in Blunt Impacts

2008 ◽  
Author(s):  
Shahab Baghaei ◽  
Ali Sadegh ◽  
Mohamad Rajaai
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Spherical Shell ◽  
Head Injuries ◽  
Head Impacts ◽  
Closed Head Injuries ◽  
Brain Motion ◽  
Closed Head ◽  
The Impact ◽  
The Brain

The relative motion between the brain and skull and an increase in contact and shear stresses in the meningeal region could cause traumatic closed head injuries due to vehicular collisions, sport accidents and falls. There are many finite element studies of the brain/head models, but limited analytical models. The goal of this paper is to mathematically model subarachnoid space and the meningeal layers and to investigate the motion of the brain relative to the skull during blunt head impacts. The model consists of an elastic spherical shell representing the skull containing a visco-elastic solid material as the brain and a visco-elastic interface, which models the meningeal layers between the brain and the skull. In this study, the shell (the head) is moved toward a barrier and comes in contact with the barrier. Consequently, the skull deforms elastically and the brain is excited to come in contact with the skull. The viscoelastic characteristics of the interface (consisting of springs and dampers) are determined using experimental results of Hardy et al. [5]. Hertzian contact theory and Newtonian method are employed to acquire time dependant equations for the problem. The governing nonlinear integro-differential equations are formed and are solved using 4th order Runge Kutta method and elastic deformation of spherical shell, brain motion during the impact, and contact conditions between the brain and the skull are evaluated. Furthermore, some important mechanical parameters such as acceleration, impact force, and the impact time duration are also specified. The results of the analytical method are validated by performing an explicit finite element analysis. Acceptable agreement between these two methods is observed. The results of the analytical investigation give the contact threshold of the skull/brain, and represent the relevant velocity of this event. Furthermore, the impact analysis in different velocities is performed in order to compare the transmitted forces and the impact durations in different cases. It is concluded that the proposed mathematical model can predict head impacts in accidents and is capable in determining the relative brain motion of the skull and the brain. The mathematical model could be employed by other investigators to parametrically study the traumatic closed head injuries and hence to propose new head injury criteria.

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