Nonfatal strangulation (NFS) can cause severe physical and psychological injury. Instances of NFS are correlated with a heightened risk of lethal violence between partners [1]. While NFS does not result in death, it can result in severe hypoxic brain injury (HBI) and has been shown to increase the likelihood of an eventual fatality in the relationship eightfold [1]. Unfortunately, minimal quantitative biomechanical research has been performed to study strangulation injury, and detection and diagnosis of NFS, which often relies upon visible injuries, remains challenging [2]. The effects of occluded cerebral venous flow on intracranial pressure (ICP) have not been considered in a model for HBI as opposed to the context of stroke and neonatal hypoxic-ischemic encephalopathy. In this project, the effects of elevated ICP on the hemodynamics and structural dynamics of a diploic vein were considered. This was done by performing transient coupled fluid-structure simulations on a segment of an intracranial vein that sought to replicate the ICP surge experienced during strangulation. The vessel model was created by isolating a segment of an intracranial vessel. Using the software 3D Slicer, the skull was extracted and exported as an STL file. From there, a segment of a diploic vein was isolated and edited by importing the STL into Blender. The segment was then processed using MeshLab and Blender to make it a solid geometry and remove potential complications. Once the vessel segment was isolated and processed, it was exported as an STL file into a commercial solver from ANSYS, Inc., Canonsburg, PA, USA. Using a coupling system of the Ansys Fluent and Mechanical models, a transient Fluid-Solid Interaction (FSI) simulation was performed by coupling ANSYS' Fluent and Mechanical models. In the simulation, blood flowed steadily through the vessel, and the data for FSI was recorded. The software was used to simulate the deformation and stress of the blood vessels caused by the blood flow for elevated intracranial pressure events for five different durations and magnitudes. Following the FSI simulations, the total deformation, equivalent stress, dynamic pressure, static pressure, and fluid velocity were plotted. The results show that altering the pressure duration can increase average total vessel wall deformation by up to 356.35%, average equivalent stress by 331.11%, dynamic pressure by 19.28%, and decrease static pressure by 30.94%. Likewise, increasing the magnitude of pressure can also increase the dynamic pressure by 17.17 %, the maximum velocity by 16.77%, and can decrease the static pressure by 27.31%. The statistical behavior of each type of modification was unique, as altering the duration created a logarithmic plot while changing the magnitude of pressure created a second power plot. With the provided data, researchers will better understand the effects of NFS-like elevated intracranial pressure on cerebral vasculature. / Master of Science / Nonfatal strangulation (NFS) has been identified as a leading indicator of escalating partner violence. The first occurrence of NFS in an intimate partnership correlated with an 8-fold increase in the risk of future attacks that are fatal by that partner. While NFS does not result in the immediate death of the victim, it can still cause severe physical and psychological harm. This includes traumatic brain injury from lack of proper blood flow, increased intracranial pressure (ICP), and hypoxia. Quantitative research on strangulation injury has mainly been carried out by forensics researchers, resulting in a lack of understanding of the biomechanics of nonfatal strangulation. This lack of knowledge, coupled with the frequent absence of visible injuries in victims of NFS, makes diagnosing NFS events particularly difficult. This study aims to begin to fill this gap by developing a computational biomechanics model of a phenomenon that occurs during NFS. The model examines how altering the duration and magnitude of a pressure wave that mimics the increased intracranial pressure during NFS can impact the blood flow and vessel motions in an intracranial blood vessel. The blood vessel model was extracted from a computed tomography (CT) scan of a patient's skull, preprocessed, and transferred into ANSYS finite element modeling software. Fluid-solid interaction (FSI) simulations were performed in ANSYS, which allowed the study of blood pressure, blood velocity, vessel deformation, and vessel stress. The results showed that increasing either the magnitude or duration of the pressure wave caused an increase in vessel stress and deformation. The results also showed that doing either increased the maximum blood velocity and dynamic pressure while decreasing the static pressure of the blood. These results contribute toward the understanding of the biomechanics of nonfatal strangulation. The model developed in this project may serve as the foundation for more complex models in future studies.

A major goal in the care of patients with neurological problems is to prevent or minimize episodes of increased intracranial pressure (ICP). Elevations in ICP in response to nursing interventions have been acknowledged since the 1960’s when ICP monitoring was first introduced in the clinical setting. Until recently few studies have specifically examined the effect of oral care on ICP and oral care and other hygiene measures were combined or not specified, prohibiting a direct interpretation of the influence of oral care alone on ICP. The purpose of this study was to describe the relationship between routine oral care interventions and the changes in ICP specifically focusing on the effect of intensity and duration of this intervention. Twenty-three patients with a clinical condition requiring ICP monitoring were enrolled over a 12 month period. Oral care provided by neuroscience intensive care nurses was observed and videotaped. Characteristics of the intervention were documented including products used, patient positioning, and duration of the intervention. A 1-5 subjective scale was used to score intensity of oral care. Wrist actigraphy data were collected from the nurses to provide an objective measure of intensity. Patient physiologic data were collected at 12 second epochs 5 minutes before, during and 5 minutes after oral care. The mixed effect repeated measures ANOVA model indicated that there was a statistically significant increase in ICP in response to oral care (p=0.0031). There was, however, no clinically significant effect on ICP. This study provides evidence that oral care is safe to perform in patients in the absence of pre-existing elevated ICP.

A hidrocefalia ainda é um desafio no que diz respeito ao diagnóstico, tratamento e acompanhamento na população pediátrica. O tratamento, por meio das derivações ventriculares ou ventriculostomias endoscópicas, está bem estabelecido. Contudo, o diagnóstico de mau funcionamento das derivações, associado à hipertensão intracraniana, permanece um problema, especialmente em crianças menores e com fontanelas não patentes. Os exames radiológicos, tais como: ultrassonografia, tomografia computadorizada e ressonância magnética, possibilitam apenas o acesso indireto à pressão intracraniana, enquanto os métodos para sua avaliação direta podem apresentar riscos e raramente são utilizados em crianças. O objetivo deste estudo foi avaliar um dispositivo não invasivo para acessar alguns parâmetros da curva de pressão intracraniana em crianças portadoras de hidrocefalia. Para tanto, foi realizado um estudo descritivo-analítico, não experimental, prospectivo. A amostra foi composta por indivíduos menores de 18 anos, incluindo 28 pacientes portadores de hidrocefalia e 28 crianças em seguimento rotina de puericultura (grupo controle). Os participantes foram divididos em quatro grupos: grupo A: hidrocefalia compensada clinicamente; grupo B: pacientes com hidrocefalia, sem sinais clínicos sugestivos de hipertensão intracraniana e já submetidos à cirurgia para tratamento da hidrocefalia; grupo C: pacientes com hidrocefalia aguda e hipertensão intracraniana; grupo D: crianças sem qualquer doença neurológica (controle). Os dados foram coletados entre 2014 e 2016, por meio da instalação de um sensor extracraniano de deformação, acoplado sobre o couro cabeludo, com registro da curva de pressão intracraniana não invasiva. A análise dos dados foi realizada com software Freemat® 4, Origin Pro® 8 e R® 3.1.3. Foram analisados parâmetros obtidos na curva de pressão intracraniana como \"relação P2/P1\", \"classificação de P1 e P2\" (P1>P2 ou P2>P1) e \"inclinação de P1\". Os resultados apontaram, que na amostra estudada, o índice P2>P1 apresentou sensibilidade de 80% e especificidade de 100%, a \"classificação de P1 e P2\" sensibilidade de 100% e especificidade de 80% para predição de hipertensão intracraniana em hidrocefalia, sendo que a \"inclinação de P1\" não apresentou relação estatística. Conclui-se que, apesar de limitações operacionais, o método de monitorização não invasiva da pressão intracraniana se mostrou útil na detecção de hipertensão intracraniana e apresenta perspectivas de aplicação clínica futura. / Hydrocephalus is still a challenge regarding diagnosis, treatment and monitoring in the pediatric population. Currently, treatments by ventricular or endoscopic ventriculostomies are well established. However, to date, the diagnosis of malfunctioning shunts associated with intracranial hypertension remains a problem, especially in young children and without patent fontanelles. Radiological examinations, such as ultrasonography, computerized tomography and magnetic resonance, allow only an indirect access to the intracranial pressure, whilst methods for direct assessment may present risks and therefore are rarely used in children. The aim of this study was to evaluate a noninvasive device to assess some parameters of the intracranial pressure curve in children with hydrocephalus. For this, we performed a prospective and non-experimental descriptive-analytic study. The sample consisted of children (under 18 years), including 28 patients with hydrocephalus and 28 children following routine child care (control group). Participants were divided into four groups; Group A: children with clinically compensated hydrocephalus; B: patients with hydrocephalus, but with no clinical signs of intracranial hypertension and no history of medical surgery for the treatment of hydrocephalus; C: patients with acute intracranial hypertension due to hydrocephalus, and D: children without neurological disease (control). Data were collected between 2014 and 2016, through the installation of an extracranial deformation sensor, coupled to the children\'s scalp, which allowed registration of non-invasive intracranial pressure curves. Data analysis was performed using Freemat® 4, Origin Pro® 8 and R® 3.1.3 software. Parameters obtained from the intracranial pressure curves were analyzed, such as \"ratio P2 / P1\", \"classification P1 and P2\" (P1> P2 or P2> P1) and \"P1 slope.\" The results showed that P2>P1 index had a sensitivity of 80% and specificity of 100%, while the \"classification of P1 and P2\" had 100% of sensitivity and 80% of specificity for predicting intracranial hypertension. \"P1 slope\" presented no statistical difference. In summary, despite some operational limitations, this study showed an useful and non-invasive method for monitoring intracranial pressure, which was able to indicate the intracranial hypertension in children with hydrocephalus and, thus, should be further investigated for clinical applications.

Made available in DSpace on 2017-07-21T14:35:56Z (GMT). No. of bitstreams: 1 Anderson Jose de Melo Silva.pdf: 2395463 bytes, checksum: ffa3d1c0f5669babc3c89ef037bd4833 (MD5) Previous issue date: 2017-10-06 / The Acute Coronary Syndrome (ACS) defines a range of clinical changes that are compatible with myocardial ischemia, resulting in the death of myocardial cells due functional deficit of blood flow, characterizing the acute myocardial infarction (AMI). The AMI is evidenced through clinical data that are reinforced by electrocardiogram (ECG), imaging and even the biochemical markers (biomarkers) evaluation, such as serum creatine phosphokinase (CK), its isoenzyme MB fraction (CK-MB), troponin and new biomarkers not yet included in routine laboratory tests, such as myeloperoxidase (MPO). In addition to new laboratory markers, science allows the development of new technologies for clinical assessment of patients, providing new information and less risk, such as non-invasive evaluation of intracranial pressure (ICP). This study is justified by the need to predict earlier the complications in patients with suspected AMI, as well as evaluate them as to the diagnosis and prognosis of the event in question. Thus, we sought to study patients with suspected ACS/AMI about the cardiovascular risk and possible PIC change through traditional biomarkers, most current markers ( "gold standard") and new biomarkers and new ICP monitoring technology. Therefore, from a population of 20 patients, randomly selected according to gender and age, separated into two groups: CK-MB≥25 IU (n = 6) and CK-MB<25 IU (n = 14), which were submitted to measurement of PIC and PAS, as well as biochemical and hematological measurements, and specific cardiac biomarkers. As a result, there was correlation of clinical significance between the values of creatine kinase MB fraction (CK-MB) and glycated hemoglobin (HGBA1C). From these data, it started to study two cases that were selected two patients. It was observed that even with changes of CK-MB, troponin and myeloperoxidase (compared to laboratory practice reference values for traditional markers and "gold standard" and MPO value considered normal in the literature), it was found not manifestations that have allowed to observe reduction of cerebral compliance, where the waves P2 are larger than P1, and therefore, there were no PIC changes identified for patients under the conditions studied. Thus, it was concluded that, even without demonstration of PIC change in this work, it is not possible to exclude the value of its inclusion in the clinical evaluation, considering that biases, like the sample universe and the time of collection of PIC or the use of medication at the admission time on hospital, may have contributed to the non-registration of changes in ICP, even in cases where patients had an unfavorable evolution of the clinical picture. / A Síndrome Coronariana Aguda (SCA) define uma gama de alterações clinicas que são compatíveis com um quadro de isquemia miocárdica, acarretando na morte de células do tecido miocárdico devido ao déficit funcional do fluxo sanguíneo, caracterizando o Infarto Agudo do Miocárdio (IAM). O IAM pode se revelar através de dados clínicos que são reforçados pelo eletrocardiograma (ECG), exames de imagem e ainda a pesquisa de marcadores bioquímicos (biomarcadores), tais como Creatinafosfoquinase (CK), sua isoenzima fração MB (CK-MB), troponina e novos biomarcadores ainda não inclusos na rotina laboratorial, tais como mieloperoxidase (MPO). Além de novos marcadores laboratoriais a ciência permite o desenvolvimento de novas tecnologias para avaliação clínica dos pacientes, proporcionando novas informações e menor risco, tais como a avaliação não invasiva da pressão intracraniana (PIC). O presente trabalho justifica-se pela necessidade de se prever intercorrências com maior antecedência em pacientes com suspeita de IAM, assim como em avaliá-los quanto ao diagnóstico e prognóstico do evento em questão. Desta forma, buscou-se estudar pacientes com suspeita de SCA/IAM quanto ao risco cardiovascular e possível alteração de PIC por meio biomarcadores tradicionais, marcadores mais atuais ("padrão ouro") e novos biomarcadores e nova tecnologia de acompanhamento da PIC. Para tanto, de uma população de 20 pacientes, escolhidos aleatoriamente quanto ao gênero e idade, separou-se em dois grupos: CK-MB≥25 UI (n=6) e CK-MB˂ 25 UI (n=14), os quais foram submetidos à aferição de PIC e PAS, além de dosagens bioquímicas e hematológicas, bem como biomarcadores cardíacos. Como resultado, observou-se correlação de significância clinica entre os valores de creatinofosfoquinase fração MB (CK-MB) e hemoglobina glicada (HgbA1C). A partir destes dados, passou-se ao estudo de dois casos clínicos em que foram selecionados dois pacientes. Foi observado que, mesmo com alterações de CK-MB, troponinas e Mieloperoxidase (comparando-se a valores de referencia da prática laboratorial para os marcadores tradicionais e "padrão ouro" e valor de MPO considerado normal em literatura especializada), constatou-se não haver manifestações que permitissem observar redução da complacência cerebral, quando as ondas P2 se dão maiores que ondas P1 e, portanto, não foram identificadas alterações de PIC para os pacientes nas condições estudadas. Com isso, concluiu-se que, mesmo não havendo demonstração de alteração de PIC neste trabalho, não se pode excluir o valor de sua inclusão na avaliação clínica, dado que vieses como universo amostral, bem como o momento da coleta da PIC e ou uso de medicação no momento da admissão hospitalar, podem ter contribuído para o não-registro de alterações da PIC, mesmo em casos que os pacientes tiveram uma evolução desfavorável do quadro clínico.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / A hemorragia subaracnÃidea (HSA) pode advir de diversos agravos ao sistema nervoso central. A HSA pode aumentar a pressÃo intracraniana (PIC) a patamares de grande morbidade. AlÃm de sintomas neurolÃgicos e cardiovasculares, bem descritos na literatura; sintomas gastrintestinais como nÃuseas, vÃmitos e gastrenterites sÃo comuns, mas pouco estudados. O retardo do esvaziamento gÃstrico (EG) à uma das alteraÃÃes fisiolÃgicas encontrada em pacientes com hipertensÃo intracraniana (HIC). Tal distÃrbio reduz as respostas terapÃuticas tendo em vista a reduÃÃo na absorÃÃo dos nutrientes e fÃrmacos, alÃm de levar à aspiraÃÃo pulmonar, que pode levar a Ãbito. Avaliamos o efeito da HSA sobre as alteraÃÃes da motilidade gastrintestinal (Esvaziamento GÃstrico - EG; TrÃnsito Intestinal â TI e ComplacÃncia GÃstrica â CG), dos parÃmetros hemodinÃmicos (PressÃo Arterial MÃdia â PAM, FreqÃÃncia CardÃaca - FC) e sobre a PIC. Bem como os mecanismos neuro-humorais relacionados a essas alteraÃÃes. Utilizamos ratos Wistar (300-350g, N=113), sob auspÃcios do COBEA (CEUA/UFC- Protocolo 41/13). ApÃs anestesia (Ketamina/Xilasina 20-10mg/Kg-IP), os animais foram contidos por estereotÃxico sendo injetados 0,1; 0,2 ou 0,3ml na cisterna magna (sangue autÃlogo â grupo HSA ou Liquor sÃmile â grupo Sham). No momento da induÃÃo da HSA os animais foram submetidos à canulaÃÃo dos ventrÃculos laterais para monitoraÃÃo da PIC e dos vasos femorais Direito a fim de se obter dados hemodinÃmicos. ApÃs 72h da induÃÃo, e sob jejum (24h) com soluÃÃo de reidrataÃÃo oral ad libitum, procedemos aos estudos de EG, TI e CG. Para determinaÃÃo da taxa de EG, uma refeiÃÃo teste (1ml/100g) (vermelho-fenol 0,5mg/ml em glicose-5%) foi administrada via gavagem. Jà o TI foi determinado com administraÃÃo direta da refeiÃÃo no duodeno por meio de cÃnula previamente implantada. Jà a CG foi avaliada utilizando um sistema de barostato a 4, 8 e 12 cm de pressÃo de distensÃo gÃstrica. A PA, FC e PIC foram aferidas no momento da avaliaÃÃo da motilidade gastrintestinal. Os dados, mÃdiaÂEPM, foram analisados pelo teste âtâ de Student (P<0,05). A HSA retardou o EG (38,90Â2,73 vs 47,00Â0,72%; 52,85Â5,14 vs 31,12Â2,0% ou 22,89Â4,46 vs 46,24Â3,56%) e aumentou a PIC (3,33Â0,47 vs 16,10Â0,47cmH2O; 7,68Â0,650 vs 30,86Â0,82cmH2O ou 17,50Â1,29 vs 37,90Â1,38cmH2O) nos diferentes volumes de sangue, seja 0,1; 0,2 ou 0,3ml respectivamente, quando comparados ao controle. A HSA tambÃm promoveu retarde no TI e diminuiÃÃo da CG, aumento da PA e diminuiÃÃo da FC. A vagotomia subdiafragmÃtica, a esplancnotomia e o prÃ-tratamento com guanetidina reverteram o efeito da HSA sobre as alteraÃÃes do EG. Os resultados sugerem que os agravos gastrintestinais advindos da HSA refletem um padrÃo de dismotilidade secundÃrios a HIC, mostrando uma forte correlaÃÃo com os valores de PIC / Subarachnoid hemorrhage (SAH) can arise from various types of damage to the central nervous system. The HSA can increase intracranial pressure (ICP) to levels high morbidity. In addition to neurological and cardiovascular symptoms, well described in the literature; gastrointestinal symptoms such as nausea, vomiting and gastroenteritis are common but little studied. The delay gastric emptying (GE) is one of the physiological changes found in patients with intracranial hypertension (ICH). This disorder reduces therapeutic responses with a view to reducing the absorption of nutrients and drugs, and lead to lung aspiration, which can lead to death. We evaluated the effect of HSA on gastrointestinal motility disorders (Gastric Emptying - EG; Intestinal Transit â IT or Gastric Compliance - CG), hemodynamic parameters (Mean Arterial Pressure - MAP, Heart Rate - HR) and the PIC. As well as neurohumoral mechanisms related to these changes. We used Wistar rats (300 - 350g, N=113) under the auspices COBEA (CEUA/UFC- Protocol 41/13). After anesthesia (Ketamine/Xylazine 20-10mg/Kg-IP), the animals were restrained by stereotactic aparatus being injected 0.1, 0.2 or 0.3 ml in the cisterna magna (autologous blood - HSA group or Liquor simile - Control group). At the time of induction of HSA, the animals were subjected to cannulation of the lateral ventricles for measurement of ICP and rigth femoral vessels in order to obtain the hemodynamic data. After 72h of induction, and fasted (24h) animals with oral rehydration solution ad libitum, proceeded studies EG, IT and CG. To determine the rate of GE a test meal (1ml/100g - phenol red - 0.5 mg/ml in 5 % glucose) was administered by gavage. The IT was already determined on direct administration of the meal into the duodenum through previously implanted cannula. Since the CG was evaluated using a barostat system at 4, 8 and 12 cm of gastric pressure distension. The MAP, HR and ICP were measured when assessing gastrointestinal motility. Data, mean  SEM, were analyzed by the "t" Student test (p<0.05). The HSA delayed gastric emptying (38.90  2.73 vs 47.00  0.72 %; 52.85  5.14 vs 31.12  2.0 % and 22.89  4.46 vs 46,24  3.56 % ) and increased the ICP (3.33  0.47 vs 16.10  0.47 cmH2O; 7.68  0.650 vs 30.86Â0.82 cmH2O and 17.50  1.29 vs 37.90  1.38 cmH2O ) in different volumes of blood, either 0.1, 0.2 or 0.3 ml, respectively, when compared to control. The HSA also promoted delay in IT and GC, increased BP and decreased HR. The subdiaphragmatic vagotomy, the esplancnotomia and pretreatment with guanethidine reversed the effect of HSA on changes in EG. The results suggest that the SAH arising gastrointestinal diseases reflect a pattern of secondary gut dysmotility, showing a strong correlation with the values of ICP

A hidrocefalia ainda é um desafio no que diz respeito ao diagnóstico, tratamento e acompanhamento na população pediátrica. O tratamento, por meio das derivações ventriculares ou ventriculostomias endoscópicas, está bem estabelecido. Contudo, o diagnóstico de mau funcionamento das derivações, associado à hipertensão intracraniana, permanece um problema, especialmente em crianças menores e com fontanelas não patentes. Os exames radiológicos, tais como: ultrassonografia, tomografia computadorizada e ressonância magnética, possibilitam apenas o acesso indireto à pressão intracraniana, enquanto os métodos para sua avaliação direta podem apresentar riscos e raramente são utilizados em crianças. O objetivo deste estudo foi avaliar um dispositivo não invasivo para acessar alguns parâmetros da curva de pressão intracraniana em crianças portadoras de hidrocefalia. Para tanto, foi realizado um estudo descritivo-analítico, não experimental, prospectivo. A amostra foi composta por indivíduos menores de 18 anos, incluindo 28 pacientes portadores de hidrocefalia e 28 crianças em seguimento rotina de puericultura (grupo controle). Os participantes foram divididos em quatro grupos: grupo A: hidrocefalia compensada clinicamente; grupo B: pacientes com hidrocefalia, sem sinais clínicos sugestivos de hipertensão intracraniana e já submetidos à cirurgia para tratamento da hidrocefalia; grupo C: pacientes com hidrocefalia aguda e hipertensão intracraniana; grupo D: crianças sem qualquer doença neurológica (controle). Os dados foram coletados entre 2014 e 2016, por meio da instalação de um sensor extracraniano de deformação, acoplado sobre o couro cabeludo, com registro da curva de pressão intracraniana não invasiva. A análise dos dados foi realizada com software Freemat® 4, Origin Pro® 8 e R® 3.1.3. Foram analisados parâmetros obtidos na curva de pressão intracraniana como \"relação P2/P1\", \"classificação de P1 e P2\" (P1>P2 ou P2>P1) e \"inclinação de P1\". Os resultados apontaram, que na amostra estudada, o índice P2>P1 apresentou sensibilidade de 80% e especificidade de 100%, a \"classificação de P1 e P2\" sensibilidade de 100% e especificidade de 80% para predição de hipertensão intracraniana em hidrocefalia, sendo que a \"inclinação de P1\" não apresentou relação estatística. Conclui-se que, apesar de limitações operacionais, o método de monitorização não invasiva da pressão intracraniana se mostrou útil na detecção de hipertensão intracraniana e apresenta perspectivas de aplicação clínica futura. / Hydrocephalus is still a challenge regarding diagnosis, treatment and monitoring in the pediatric population. Currently, treatments by ventricular or endoscopic ventriculostomies are well established. However, to date, the diagnosis of malfunctioning shunts associated with intracranial hypertension remains a problem, especially in young children and without patent fontanelles. Radiological examinations, such as ultrasonography, computerized tomography and magnetic resonance, allow only an indirect access to the intracranial pressure, whilst methods for direct assessment may present risks and therefore are rarely used in children. The aim of this study was to evaluate a noninvasive device to assess some parameters of the intracranial pressure curve in children with hydrocephalus. For this, we performed a prospective and non-experimental descriptive-analytic study. The sample consisted of children (under 18 years), including 28 patients with hydrocephalus and 28 children following routine child care (control group). Participants were divided into four groups; Group A: children with clinically compensated hydrocephalus; B: patients with hydrocephalus, but with no clinical signs of intracranial hypertension and no history of medical surgery for the treatment of hydrocephalus; C: patients with acute intracranial hypertension due to hydrocephalus, and D: children without neurological disease (control). Data were collected between 2014 and 2016, through the installation of an extracranial deformation sensor, coupled to the children\'s scalp, which allowed registration of non-invasive intracranial pressure curves. Data analysis was performed using Freemat® 4, Origin Pro® 8 and R® 3.1.3 software. Parameters obtained from the intracranial pressure curves were analyzed, such as \"ratio P2 / P1\", \"classification P1 and P2\" (P1> P2 or P2> P1) and \"P1 slope.\" The results showed that P2>P1 index had a sensitivity of 80% and specificity of 100%, while the \"classification of P1 and P2\" had 100% of sensitivity and 80% of specificity for predicting intracranial hypertension. \"P1 slope\" presented no statistical difference. In summary, despite some operational limitations, this study showed an useful and non-invasive method for monitoring intracranial pressure, which was able to indicate the intracranial hypertension in children with hydrocephalus and, thus, should be further investigated for clinical applications.

Glaucoma affects tens of millions of people and is the leading cause of irreversible blindness worldwide. Virtually all current glaucoma therapies target elevated intraocular pressure (IOP); however, the contribution of intracranial pressure (ICP) to glaucoma has recently garnered interest. Strain at the optic nerve head is now known to depend on the translaminar pressure difference (TLPD), which is the difference between IOP and ICP, rather than IOP alone. A better understanding of how IOP and ICP relate to glaucoma development and progression is essential for developing improved therapies and diagnostic tests. Glaucoma is commonly modeled in rats, yet aqueous humor dynamics are not well-documented in healthy nor diseased rat eyes. Moreover, because rats do not develop glaucoma spontaneously, it is essential to develop low-cost, reliable, and relevant models of glaucomatous pathology in the animal. The purpose of this dissertation work is to achieve the following goals: i) quantitatively assess aqueous humor dynamics in healthy, living rat eyes, ii) develop an ideal model of experimental glaucoma in rats, iii) quantitatively characterize aqueous humor dynamics throughout experimental glaucoma in living rats, and iv) investigate the effects of ICP manipulations on aqueous humor dynamics in living rats. Chapter 2 reports physiological parameters of aqueous humor dynamics for the first time in the eyes of living, healthy Brown-Norway rats, and presents a novel perfusion technique for efficiently and accurately estimating these parameters. Chapter 3 introduces the constant-pressure perfusion model of experimental glaucoma: a powerful new model which overcomes several limitations of existing techniques. The constant-pressure perfusion model induces IOP elevations which are prescribable and easily manipulated, does not directly target the trabecular meshwork or its vasculature, and offers continuous records of IOP rather than requiring regular animal handling and tonometry. Chapter 3 characterizes IOP-induced optic neuropathies in rats and demonstrates their resemblance to human glaucoma. Chapter 4 evaluates whether the constant-pressure perfusion model affects ocular physiology, specifically showing that resting IOP and conventional outflow facility are not permanently nor significantly altered in the model. Chapter 5 examines the effect of ICP manipulations on aqueous outflow physiology in living rats, and reports for the first time a graded effect of intracranial hypertension on conventional outflow facility. Evidence for a neural feedback mechanism that may serve to regulate the TLPD is also presented. Chapter 6 summarizes the results of this dissertation, provides recommendations for future work, and gives closing remarks. These collective projects provide insight into IOP regulation in both healthy and diseased rat eyes, advancing our understanding of glaucomatous development and damage in rats. A novel model of experimental glaucoma and several perfusion systems have been developed which are distinctly tailored for use in future glaucoma studies and will allow future investigators to study the disease with enhanced efficiency and exactitude. The results of this dissertation work suggest that detecting and correcting impairments of either IOP or ICP homeostatic capabilities may be of utmost importance for improving clinical outcomes in human glaucoma.

Cerebrospinal fluid (CSF) infusion tests can be used to estimate the dynamic properties of the CSF system. Idiopathic normal pressure hydrocephalus (INPH) is a syndrome signified by a disturbance to the CSF system, where the cause is unknown and the diagnosis is difficult to determine. As an aid in identifying patients with INPH who will improve after shunt surgery, infusion tests are commonly used to determine the outflow conductance (Cout), or outflow resistance (Rout=1/Cout), of the CSF system. The tests are also used to determine shunt function in vivo. The general aim of this thesis was to develop and validate CSF infusion methods, to investigate the dynamics of the CSF system. The methods should be applicable to patients with INPH, to aid in the quest to further improve the diagnosis and management of this syndrome. An existing mathematical model describing the dynamics of the CSF system was further developed. The characteristics of the model were verified and the effect of expanding intracranial air on the intracranial pressure (ICP) was simulated. The simulations supported the recommendation to maintain sea-level pressure during air ambulance transportation of patients with suspected intracranial air. A recently developed infusion apparatus was evaluated, on an experimental model as well as on a patient material. The repetitiveness in estimating Cout was found to be good. A statistically significant difference was found between the repeated Cout estimations in the patient group, indicating that there might have been a small physiological change introduced during the infusion test. A parameter, ∆Cout, was proposed and evaluated. It proved to reflect the reliability of individual Cout investigations in a clinically useful way, as well as to provide easily interpreted information. An adaptive algorithm for assessment of Cout was developed and evaluated on a patient group. The new algorithm was shown to reduce the investigation time, from 60 minutes, by 14.3 ± 5.9 minutes (mean ± SD), p&lt;0.01, without reducing the reliability of the estimated Cout below clinically relevant levels. The relationship between ICP and CSF outflow was studied in a group of patients investigated for INPH. It was found that in the range of moderate increase from baseline pressure, the assumption of a pressure independent Rout was confirmed (p=0.5). However, at larger pressure increments, the relationship had a non-linear tendency (p&lt;0.05). This indicates that the traditional view of a pressure independent Rout might have to be questioned in the region where ICP exceeds baseline pressure too much. Infusion tests can be performed in different ways, where three main categories may be distinguished. The bolus infusion method was compared to the constant pressure and constant flow infusion methods, on an experimental model as well as on a patient material. When physiological pressure fluctuations were added to the model, significant differences were found in the determination of Cout in the range of clinical importance, i.e. low Cout (p&lt;0.05). The finding was supported by the patient investigations, the difference was however not significant. With the application of the new methods developed in this thesis, and the increased knowledge concerning relationships between CSF dynamic parameters, the CSF infusion test was further improved with the ability to increase measurement reliability in a reduced time. This constitutes a good basis to perform a large multi-centre study with the main goal to determine the predictive value of the parameter Cout.

Following a head concussion the intracranial pressure increases due to the impact, which cannot be adequately relieved because of the stiffness of the skull. Popular strategies aimed at decompressing the head consist in the administration of osmotic agents and skull removal. The mechanical properties of bone can be affected by the administration of different solutions. If the malleability of skull is influenced by the osmotic agents that are administered to the patient then the pressure and volume in the intracranial cavity can also be modified following the treatment. In this thesis research, we hypothesize that administered osmotic agents can influence the mechanical properties of the skull, which can also impact the volume the cavity can hold and subsequently the pressure in the head. This premise was tested by modifying existing mathematical models compiled through two general MATLAB codes that allow the computation of a non-symbolic differential-algebraic initial value problem. Three main features were changed in comparison to current models: the skull's influence on the pressure and volume modulation was tested (inputs were obtained from skull tested under different solutions); pulsatile flow was accounted for on the creation and movement of cerebrospinal fluid; and the input on the mechanical behavior of the cranial vessels was accounted for through previously published continuum-mechanics vessel-behavior models. To complete the model, materials and mechanical properties were obtained through laboratory experiments as well as data collection from existing literature. From our bone test we were able to conclude that there are different factors that affect the mechanical properties of bone in various degrees. There is a mild statistical correlation (p-value 0.05) between the mechanical properties of bone obtained from different regions of the skull samples (2-14mm) and the DPBS and hDPBS solutions. Additionally there is a strong statistical difference (p-value 0.05) between the mechanical properties obtained from cross head speed (0.02, 0.002, and 0.004 (mm/s)) and solution variation (DI, DPBS and hDPBS). Finally, we were able to see that there seems to be a correlation between the mechanical properties of bone, the solution treatments and hypertension; although more test need to be developed to affirm this premise since our results are preliminary.

Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 4 uppsatser.