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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Quantifying the Response of Relative Brain/Skull Motion to Rotational Input in the PMHS Head

Guettler, Allison Jean 27 February 2018 (has links)
Post-mortem human surrogate (PMHS) head specimens were subjected to two different angular speed pulses. Each pulse was approximately a half-sine with either a peak angular speed of either 40 or 20 rad/s and duration of either 30 or 60 milliseconds. High-speed biplane x-ray was used to record the motion of the brain and skull via radio-opaque markers implanted at specified locations in the brain, and lead markers on the skull. Specimens were perfused to physiologic conditions throughout preparation and testing to maintain the integrity of the brain tissue and ensure coupling of the brain and skull. Intracranial pressure was measured anteriorly and posteriorly. The test event was controlled by a cam-follower-flywheel mechanism, which facilitated control of pulse parameters and provided a form of "infinite energy" so that the device and therefore the test input would not be influenced by the characteristics of the object under test. This approach kept the independent and dependent variables separated. The brain targets were also deployed in a prescribed manner with two methodologies that were scalable to different specimens. The repeatable input and target deployment schemes helped reduce experimental variation (between tests and subjects) to produce consistent response data. Displacement of the brain was calculated with respect to a body-fixed basis on the skull. The relative motion of the brain with respect to the skull was shown to be dependent on the location of the target in the brain. The major deformation axis of each target followed the contour of the skull or bony landmark to which it was closest. Intracranial pressure was relatively low because the changes were due to inertial effects in the absence of impact. Tests with lower speeds and longer durations produced less deformation, lower intracranial pressures, and longer pressure durations than the tests that were high-speed, short-duration. The response of the brain to rotation of the head was quantified at two test levels and on two PMHS specimens. / Master of Science / Motor-vehicle collisions (MVCs) are the second leading cause of traumatic brain injury (TBI) in the United States and the leading cause of TBI-related death [1a]. Regulations are in place for vehicle design to reduce the occurrence and severity of head injuries during MVCs. The metric used is based on the resultant linear acceleration at the center of gravity of the occupant’s head. However, TBI are still occurring despite the current regulations. This suggests the importance of using additional injury metrics to predict TBI in MVCs. In automotive impact biomechanics, a combination of real world, experimental, and simulation data is used to determine how the human body responds during MVCs. While computer (finite element) simulations can provide extensive information about the kinematic and kinetic response of the human body, these models require experimental data to validate and evaluate their responses. This study focuses on determining the response of the human cadaver brain to angular speed loading without contact of the head. High-speed biplane x-ray and radiopaque markers were used to quantify the displacement of the brain with respect to the skull throughout rotational events. Two angular speed profiles with different peak angular speeds and durations were used. The methods were determined to reduce experimental variation to obtain data that is useful for finite element model validation. The average peak angular speed for the high-speed tests was 41.8 rad/s and the average peak angular speed for the low-speed tests was 22.0 rad/s. The peak angular speed only varied by 10% between similar tests. The motion of the brain lagged behind that of the skull, producing a relative displacement of the brain with respect to the skull. The magnitude and primary direction of the relative displacement was dependent on the location at which it was measured. The location of the radiopaque target with respect the anatomical coordinate system and bony landmarks of the skull are both important in determining the characteristics of the relative displacement profiles. The high-speed tests produced an average displacement of +/-5 mm, while the low-speed tests had an average displacement of +/-2.5 mm in the X-direction. Intracranial pressure (ICP) was also measured at two points in the cranial cavity, and showed the delayed response of the brain to the rotational loading of the head.
42

Smartphone inom rehabilitering för personer med förvärvad hjärnskada : En litteraturstudie / Smartphone in rehabilitation for people with acquired brain injury : A literature review

Anderberg, Rosie, Bäckman, Viktoria January 2019 (has links)
Syfte:Syftet med litteraturstudien var att undersöka hur en smartphone kan användas inom rehabilitering efter FHS, i vilken utsträckning smartphonen används. Vilka effekter smartphonen kan ge på i det dagliga livet samt betydelsen en smartphone kan utgöra. Metod:För att besvara syftet så utfördes en litteraturstudie som innefattar kvalitativ och kvantitativ forskning baserad på åtta studier.  Resultat:Smartphonen har många fördelar som ett kompensatoriskt hjälpmedel samt är betydelsefull för personerna i det dagliga livet på många sätt. Signifikanta effekter kunde uppmätas som ledde till att fler aktiviteter både påbörjas och avslutades i rätt tid, därmed så hanteras många av grundproblemen med förvärvad hjärnskada (FHS), såsom svårigheter med minne, planering, initiering och organisering. Smartphonen föredrogs också av användarna framför andra hjälpmedel.  Slutsats:Studien visar att de finns stora fördelar med att implementera smartphonen som en del av rehabiliteringen av förvärvad hjärnskada. Vidare visar studien att smartphonen är den del av människors liv oavsett med eller utan FHS.  Det finns behov av vidare forskning inom ämnet då det finns få studier som belyser smartphonens som kompensatoriskt hjälpmedel i dagsläget. / Aim: The aim of this literature study was to describe how the smartphone is used as a compensatory aid in rehabilitation and the importance it can have for people with acquired brain injury. Method: To answer the purpose, a literature study was carried out which included qualitative and quantitative research based on eight studies. Result: The smartphone has many advantages as a compensatory aid and it shows important for people with acquired brain injury in their daily life in many ways. Significant effects could be measured which led to more activities being initiated and completed at the right time, thus many of the basic problems with acquired brain injury are addressed, such as problems with memory, planning, initiation and organization. The smartphone was also preferred by the users in front of other devices. Conclusion: The study shows great advantages in implementing the smartphone as part of the rehabilitation of acquired brain injury. Furthermore, the study shows that the smartphone is the part of people's lives regardless of if they suffer from acquired brain damage or not. There is a need for further research within the subject since there are few studies that shed light on smartphone's as compensatory aid at present.
43

The use of somatosensory evoked potentials in the prediction of outcome in brain injured children

Carter, Bradley Graham, n/a January 2006 (has links)
This thesis describes studies assessing the ability of somatosensory evoked potentials (SEPs) to predict outcome following severe brain injury by examining outcome and determining the predictive value of SEPs directly and in comparison to alternative tests in both patients and systematic reviews of the literature. Outcome was assessed using a functional and quality of life measure. It changed over time and was influenced by age, mechanism, timing and the type of outcome measure. When 5 year functional outcome was used, sensitivity and specificity for the initial SEPs were 63.2% and 93.3% with a positive predictive value of 92.3% for favourable outcome and 66.7%, 94.7% and 90.9% for unfavourable outcome prediction. SEPs predictive performance varied and was better in patients with 1 year outcomes, when outcome was measured with the quality of life tool and in patients suffering hypoxicischaemic encephalopathy. Importantly, only twelve false positives were identified in the systematic review of 55 studies from 903 patients with bilaterally absent SEPs. Eight of these false positives suffered focal lesions of the brain stem, large cerebral fluid collections or recent decompressive craniectomy which cause SEPs to be absent because of a mechanical disruption to the electrical signal. Comparisons between SEPs and other tests in the patient cohort and wider literature showed that SEPs were the best overall predictors of outcome but were outperformed by some clinical tests in specific areas. Specificity for unfavourable outcome prediction was better for ICP, CPP and the last pupillary response. In patients with any cause of brain injury, the combination of SEPs and Motor responses provided the best predictions for unfavourable outcome while for favourable outcome the best overall prediction and specificity were achieved with a combination of either SEPs or Motor responses and the best sensitivity with pupillary responses alone or a combination of either SEPs or Pupillary responses. The studies in this thesis provide a detailed evaluation of SEPs and showed that SEPs have a place in the prediction of outcome, alone or in combination with existing tests. Overall, they are superior to clinical tests and can be easily obtained at the bedside and in the presence of pharmacological paralysis and analgesia/sedation.
44

Psychosocial Functioning of Children Living with a Brain-Injured Parent

Lillie, Rema Andrea 07 October 2013 (has links)
Historically, there has been limited empirical study of children whose parents have suffered an acquired brain injury. This is despite the fact that both clinical opinion and qualitative study suggest that these children may represent a population at risk for a variety of emotional and behavioral problems. The current study set out to evaluate the overall psychosocial functioning of a small subset of children whose parents had suffered an acquired brain injury (TBI, stroke) and who were in the more chronic phase of recovery (average time post-injury = 3.3 years). Factors that have been proposed to impact child psychosocial functioning in this population were assessed including the neurobehavioral profile of the parent with an injury, parental depression, and the child’s report of the parental relationship. In all, ten children (average age = 13 years) from seven families with parental ABI were evaluated both on a comprehensive measure of child psychosocial functioning (BASC-2) and a series of qualitative measures. As compared to a normative sample, results of quantitative analyses suggest a group of children not experiencing general clinical distress. In fact, statistical analyses suggest resiliency in the current sample as compared to normative data. At the individual level, two of the children in the sample evidenced behavior that warrants further clinical evaluation, though this finding may be on par with the base rates of clinical distress seen in the general population. Qualitative analyses provide a richer understanding of the experiences of these children and their families and suggest avenues for further empirical evaluation. Results are presented in the context of other studies to date. Recommendations for clinicians and researchers based on current findings are provided. / Graduate / 0622 / rlillie@uvic.ca
45

Dimensions of post-concussive symptoms in children with mild traumatic brain injury

Ayr, Lauren K. 16 July 2007 (has links)
No description available.
46

Comprehensive Assessment of Nanoparticle Delivery after Experimental Traumatic Brain Injury

January 2018 (has links)
abstract: Traumatic brain injury (TBI) is a leading cause of disability worldwide with 1.7 million TBIs reported annually in the United States. Broadly, TBI can be classified into focal injury, associated with cerebral contusion, and diffuse injury, a widespread injury pathology. TBI results in a host of pathological alterations and may lead to a transient blood-brain-barrier (BBB) breakdown. Although the BBB dysfunction after TBI may provide a window for therapeutic delivery, the current drug delivery approaches remains largely inefficient due to rapid clearance, inactivation and degradation. One potential strategy to address the current therapeutic limitations is to employ nanoparticle (NP)-based technology to archive greater efficacy and reduced clearance compared to standard drug administration. However, NP application for TBI is challenging not only due to the transient temporal resolution of the BBB breakdown, but also due to the heterogeneous (focal/diffuse) aspect of the disease itself. Furthermore, recent literature suggests sex of the animal influences neuroinflammation/outcome after TBI; yet, the influence of sex on BBB integrity following TBI and subsequent NP delivery has not been previously investigated. The overarching hypothesis for this thesis is that TBI-induced compromised BBB and leaky vasculature will enable delivery of systemically injected NPs to the injury penumbra. This study specifically explored the feasibility and the temporal accumulation of NPs in preclinical mouse models of focal and diffuse TBI. Key findings from these studies include the following. (1) After focal TBI, NPs ranging from 20-500nm exhibited peak accumulation within the injury penumbra acutely (1h) post-injury. (2) A smaller delayed peak of NP accumulation (40nm) was observed sub-acutely (3d) after focal brain injury. (3) Mild diffuse TBI simulated with a mild closed head injury model did not display any measurable NP accumulation after 1h post-injury. (4) In contrast, a moderate diffuse model (fluid percussion injury) demonstrated peak accumulation at 3h post-injury with up to 500 nm size NPs accumulating in cortical tissue. (5) Robust NP accumulation (40nm) was found in female mice compared to the males at 24h and 3d following focal brain injury. Taken together, these results demonstrate the potential for NP delivery at acute and sub-acute time points after TBI by exploiting the compromised BBB. Results also reveal a potential sex dependent component of BBB disruption leading to altered NP accumulation. The applications of this research are far-reaching ranging from theranostic delivery to personalized NP delivery for effective therapeutic outcome. / Dissertation/Thesis / Doctoral Dissertation Biomedical Engineering 2018
47

Effect of Progesterone Administration in Traumatic Subarachnoid Hemorrhage

Lunney, Michael 15 May 2015 (has links)
INTRODUCTION: Traumatic brain injury (TBI) is a major public health problem, causing approximately 52,000 deaths from 1.7 million injuries in the United States annually, with a combined direct and indirect economic cost estimated at $60-75 billion per year. Traumatic subarachnoid hemorrhage (tSAH), a subtype of closed head injury, has a high prevalence within TBI—evident in up to two-thirds of moderately and severely brain injured patients. tSAH is also associated with poor clinical outcomes; some research suggests mortality and unfavorable outcome rates are two-to-three times higher in patients with tSAH, based on brain imaging, compared to those without. To date, no pharmacological treatment has been conclusively shown to improve outcomes in humans for either moderate or severe TBI or for specific tSAH injury. The aim of this study was to assess whether the effect of PROG was substantially different in study TBI patients with evidence of tSAH on initial brain imaging compared to those that did not have evidence of tSAH. METHODS: ProTECT III clinical trial data was used for an exploratory, post hoc subgroup analysis to determine the effect of the hormone progesterone (PROG) on outcome. Study subjects with any abnormality on baseline brain imaging were included in the analysis and two subgroups, tSAH positive (+tSAH) and tSAH negative (–tSAH), were selected. The primary outcome evaluated was a favorable/unfavorable dichotomy derived from the 6-months post-injury Extended Glasgow Outcome Scale (GOSE) assessment, which evaluates both mortality and functional outcomes. Risk ratios (RRs) were calculated for the total sample and each of the two subgroups and used as statistical evidence for interaction between PROG and tSAH. RESULTS: All subjects from the original ProTECT III trial cohort (N=882) with no abnormalities found on baseline computed tomography (CT) image (n=125) or missing image (n=1) were excluded from this analysis. Subjects with one or more abnormalities noted on CT (+CT, n=756) were then divided into subgroups based on presence (n=582) or absence (n=174) of tSAH. Subjects with +tSAH were more severely injured than –tSAH (mean Rotterdam CT score 3.3 vs. 2.2; 3.1 overall) and had a lesser proportion of favorable outcomes (47.4% vs. 74.3%; 53.6% overall). Compared to placebo, patients treated with progesterone had marginally better likelihood of favorable outcomes (risk ratio among +tSAH 1.06, 95% confidence interval [CI], 0.89 to 1.26; and RR among –tSAH 1.02, 95% CI 0.85 to 1.22). A multivariable model, adjusted for baseline differences in treatment group covariates did not yield substantially different results for the effect of progesterone on favorable outcomes (+tSAH 1.07; 95% confidence interval [CI], 0.84 to 1.36, –tSAH 1.08; 95% CI 0.75 to 1.56, +CT 1.06; 95% CI 0.87 to 1.29). CONCLUSION: Our study demonstrated that progesterone did not result in different effects in patients with or without tSAH than those without based on initial brain imaging. This investigation supports previous research findings; tSAH is correlated with more severe injury and worsened outcomes. Concomitant injuries found in +tSAH group are likely worsening the outcomes over –tSAH, but this was not evaluated here. More complex statistical modeling should be used on this data to determine if it provides evidence that tSAH is an independent prognosticator of unfavorable outcome or merely associated with more severely injured patients.
48

The Nova Multilingual Neuropsychological Battery: Traumatic Brain Injury Pilot Study

Figueroa, Maritza Jeannette 01 January 2010 (has links)
The purpose of the current study was to determine if the Nova Multilingual Neuropsychological Battery (NMNB) can detect neurological deficits in the traumatic brained injured (TBI) Hispanic sample by comparing subtest mean scores to the normal group mean scores. The NMNB is comprised of 39 subtests and was developed to account for language and cultural factors thought to influence neuropsychological test results. It was hypothesized that significant differences would be found in NMNB measures sensitive to brain damage. A sample size of 100 English-Spanish speaking bilinguals (50 TBI and 50 cognitively intact participants) was tested in Spanish in order to compare cognitive performance across the various NMNB measures. Due to the number of comparisons, the alpha level for this study was set to .01 to reduce Type I error. Results of the ANCOVA's partially supported the hypothesis after controlling for age and education. Findings show that the NMNB measures were able to successfully detect the TBI Spanish group from the normal Spanish group. Significant differences were displayed in the tests measuring nonverbal abilities, memory and learning, visual spatial skills, and executive functioning. More specifically, no significant differences were displayed in the tests measuring crystallized premorbid abilities, while tests measuring more fluid abilities detected problems with abstract thinking and information processing in the TBI sample. A similar deficit pattern was displayed across all measures of higher functioning systems. Deficits were detected in the nonverbal measures that involved complex attention (selective, divided, and alternating forms of attention) and concentration for visuospatial tasks, pattern synthesis and manipulation, but not for simple visuospatial attentional activities. Significant differences were found in motor speed, but not in the number of errors. These findings support previous research indicating that Hispanics tend to favor accuracy over speed. Additionally, results reveal significant differences across all memory measures. Using Cohen's d, large effect sizes were displayed between the groups ranging from 1.5 to 2.3 in the verbal and visual memory measures. Similar effect sizes were also displayed in tests of executive functioning. Preliminary data of this study suggests that the NMNB may be a sound assessment tool for detecting neurological impairments in TBIs. Collectively, the NMNB displayed significant differences in motor and processing speed, memory, visuospatial tasks, and executive functioning commonly documented in non-Hispanic TBIs. This study concluded that culturally sensitive neuropsychological tests that also control for demographic variables such as age and education can provide accurate results for Hispanics with TBI. However, these results should be interpreted with caution as this study was limited to a small sample size with an unequal proportion of TBI severity levels and educational experiences beyond educational levels. Future studies should focus on obtaining larger samples with varying TBI severity levels. Samples should also include bilingual Hispanics tested in English as well as monolingual Spanish speakers in order to develop profiles that may be useful in differential diagnosis.
49

Mild Traumatic Brain Injury Produces More Immediate and Prolonged Synaptic Plasticity Deficits in the Juvenile Female Hippocampus

White, Emily R. 29 April 2015 (has links)
Traumatic brain injury (TBI) is the leading cause of disability in individuals under 45 years of age, with mild TBI (mTBI) accounting for the majority of cases. The juvenile brain is in a period of robust synaptic reorganization and myelination, making adolescence a particularly vulnerable time to incur a TBI. Learning and memory deficits that involve the hippocampal formation are often observed following mTBI in adults. To examine this issue in the juvenile brain, we assessed changes in hippocampal synaptic plasticity following closed-head mTBI in male and female Long-Evans rats (25-28 days of age). Synaptic plasticity of field excitatory post-synaptic potentials (fEPSPs) was assessed using in vitro electrophysiology at either one hour, one day, seven days, or 28 days following mTBI in the dentate gyrus (DG) and the cornu ammonis area 1 (CA1) regions of the hippocampus. In female rats, the CA1 region ipsilateral to the impact showed a significant reduction in long-term potentiation (LTP) as early as one hour following mTBI. Similar LTP deficits were apparent at one day in the DG, and persisted to 28 days following injury. In male rats, a deficit in both DG- and CA1-LTP was maximal in the ipsilateral hemisphere by seven days following injury, but these deficits did not persist to 28 days post-injury. These data suggest that the juvenile brain is susceptible to mTBI-induced impairments in plasticity, and sex and regional differences are apparent in the expression and recovery of synaptic plasticity following mTBI. / Graduate
50

Severe traumatic brain injury : clinical course and prognostic factors

Stenberg, Maud January 2016 (has links)
Traumatic brain injury (TBI) constitutes a major health problem and is a leading cause of long-term disability and death. Patients with severe traumatic brain injury, S-TBI, comprise a heterogeneous group with varying complexity and prognosis. The primary aim of this thesis was to increase knowledge about clinical course and outcome with regard to prognostic factors. Papers I, II and III were based on data from a prospective multicentre observational study from six neurotrauma centers (NCs) in Sweden and Iceland of patients (n=103-114), 18-65 years with S-TBI requiring neurosurgical intensive care or collaborative care with a neurosurgeon (the “PROBRAIN” study).  Paper IV and V were performed on a regional subset (n=37). In Paper I, patients with posttraumatic disorders of consciousness (DOC) were assessed as regards relationship between conscious state at 3 weeks and outcomes at 1 year. The number of patients who emerged from minimally conscious state (EMCS) 1 year after injury according to status at 3 weeks were: coma (0/6), unresponsive wakeful syndrome (UWS) (9/17), minimally conscious state (MCS) (13/13), anaesthetized (9/11). Outcome at 1 year was good (Glasgow Outcome Scale Extended (GOSE>4) in half of the patients in MCS (or anaesthetized) at 3 weeks, but not for any of the patients in coma or UWS.    In Paper II, the relationships between clinical care descriptors and outcome at 1 year were assessed. A longer length of stay in intensive care, and longer time between discharge from intensive care and admission to inpatient rehabilitation, were both associated with a worse outcome on the GOSE. The number of intervening care units between intensive care and rehabilitation, was not significantly associated with outcome at 1 year.  In Paper III, the clinical course of cognitive and emotional impairments as reflected in the Barrow Neurological Institute Screen for Higher Cerebral Functions (BNIS) and the Hospital Anxiety and Depression Scale (HADS) were assessed from 3 weeks to 1 year together with associations with outcomes GOSE and Rancho Los Amigos Cognitive Scale-Revised (RLAS-R) at 1 year. Cognition improved over time and appeared to be stable from 3 months to 1 year.  In Paper IV, clinical parameters, the clinical pathways from injury to 3 months after discharge from the NC in relation to outcomes 3 months post-injury. Ratings on the RLAS-R improved significantly over time. Eight patients had both “superior cognitive functioning” on the RLAS-R and “favourable outcome” on the GOSE. Acute transfers to the one regional NC was direct and swift, transfers for postacute rehabilitation scattered patients to many hospitals/hospital departments, not seldom by several transitional stages.  In Paper V, an initial computerized tomography of the brain (CTi) and a further posttraumatic brain CT after 24 hours (CT24) were evaluated according to protocols for standardized assessment, the Marshall and Rotterdam classifications. The CT scores only correlated with clinical outcome measures (GOSE and RLAS-R) at 3 months, but failed to yield prognostic information regarding outcome at 1 year. A prognostic model was also implemented, based on acute data (CRASH model). This model predicted unfavourable outcomes for 81% of patients with bad outcome and for 85% of patients with favourable outcome according to GOSE at 1 year. When assessing outcomes per se, both GOSE and RLAS-R improved significantly from 3 months to 1 year.  The papers in this study point both to the generally favourable outcomes that result from active and aggressive management of S-TBI, while also underscore our current lack of reliable instruments for outcome prediction. In the absence of an ability to select patients based on prognostication, the overall favourable prognosis lends support for providing active rehabilitation to all patients with S-TBI. The results of these studies should be considered in conjunction with the prognosis of long-term outcomes and the planning of rehabilitation and care pathways. The results demonstrate the importance of a combination of active, acute neurotrauma care and intensive specialized neurorehabilitation with follow-up for these severely injured patients.

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