Intact white matter is critical for normal cognitive function. In traumatic brain injury (TBI), chronic cerebral hypoperfusion and Alzheimer’s disease (AD) damage to white matter is associated with cognitive impairment. However, these conditions are associated with grey matter damage or with other pathological states and the contribution of white matter damage in isolation to their pathogenesis is not known. Furthermore, TBI is a risk factor for AD and cerebral hypoperfusion is an early feature of AD. It is hypothesised that white matter damage following TBI or chronic cerebral hypoperfusion will be associated with cognitive deficits and that white matter changes after injury contribute to AD pathogenesis. To investigate this, this thesis examined the contribution of white matter damage to cognitive deficits after TBI and chronic cerebral hypoperfusion and furthermore, investigated the role of white matter damage in the relationship between TBI and AD. Three studies addressed these aims. In the first, mild TBI was induced in wild-type mice and the effects on axons, myelin and neuronal cell bodies examined at time points from 4 hours to 6 weeks after injury. Spatial reference learning and memory was tested at 3 and 6 weeks after injury. Injured mice showed axonal damage in the cingulum, close to the injury site in the hours after injury and at 6 weeks, damage in the thalamus and external capsule were apparent. Injured and sham animals had comparable levels of neuronal damage and no change was observed in myelin. Injured animals showed impaired spatial reference learning at 3 weeks after injury, demonstrating that selective axonal damage is sufficient to impair cognition. In the second study mild TBI was induced in a transgenic mouse model of AD and the effects on white matter pathology and AD-related proteins examined 24 hours after injury. There was a significant increase in axonal damage in the cingulum and external capsule and parallel accumulations of amyloid were observed in these regions. There were no changes in tau or in overall levels of AD-related proteins. This suggests that axonal damage may have a role in mediating the link between TBI and AD. The third study used a model of chronic cerebral hypoperfusion in wild type mice and investigated white matter changes after one and two months of hypoperfusion as well as a comprehensive assessment of learning and memory. Chronic cerebral hypoperfusion resulted in diffuse myelin damage in the absence of ischaemic neuronal damage at both 1 and 2 months after induction of hypoperfusion. Hypoperfused animals also showed minimal axonal damage and microglial activation. Cognitive testing revealed a selective impairment in spatial working memory but not spatial reference or episodic memory in hypoperfused animals, showing that modest reductions in blood flow have effects on white matter sufficient to cause cognitive impairment. These results demonstrate that selective damage to white matter components can have a long-term impact on cognitive function as well as on the development of AD. This suggests that minimisation of axonal damage after TBI is a target for reducing subsequent risk of AD and that repair or prevention of white matter damage is a promising strategy for rescuing cognitive function in individuals who have experienced mild TBI or chronic cerebral hypoperfusion.

Background and aims: The provenance of post-concussion symptoms (PCS) and post-traumatic stress (PTSD) after mild traumatic brain injury (mTBI) is controversial. This thesis investigated factors influencing these two conditions separately, as well as the interplay between PCS and PTSD, in individuals with mTBI and a control sample without mTBI (orthopaedic injuries). Method: Consecutive adult attendees of an Emergency Department with mTBI or orthopaedic injury were prospectively recruited and completed the Rivermead Post-concussion Questionnaire (RPQ) and Trauma Screening Questionnaire (TSQ) for PTSD at two weeks (T1) and three months (T2) post-injury. The sample at T1 consisted of 34 with complicated mTBI, 76 with uncomplicated mTBI and 47 with orthopaedic injury, and 18 with complicated mTBI, 43 with uncomplicated mTBI and 33 orthopaedic controls at T2. Results: Although there were no differences in overall PCS symptomology between groups, a subset of PCS symptoms (headaches, dizziness and nausea) was found to be specific to mTBI at both time points. These symptoms are proposed to have a neurological basis, as opposed to a psychological basis. PTSD interacted with PCS, particularly in mTBI, such that PTSD was associated with greater “neurogenic” and “psychogenic” symptomology in this group, but only a moderate increase in psychogenic symptoms for controls. A model of the influence of PTSD on PCS is presented. PTSD was influenced by poor memory quality for the traumatic event and attribution of blame to others, but not by mTBI. Discussion and conclusions: Though mTBI may set the scene for at least neurogenic symptoms of PCS to occur, psychological mechanisms, particularly PTSD, have a significant role in the persistence of PCS. Our findings suggest the need for a clear story and sense of meaning for a traumatic event for good recovery from PTSD. Taken together, the results suggest that psychological interventions, particularly aimed at PTSD, may be most effective after mTBI.

Few studies have explored emotion processing abilities in children following Acquired Brain Injury (ABI). This study develops previous research in this area by exploring emotion processing skills in children with focal ABI, using eye tracking technology. It was hypothesised that children with focal ABI would demonstrate impaired emotion recognition abilities relative to a control group and that, similar to adult eye tracking studies, they would show an atypical pattern of eye moments when viewing faces. Sixteen participants with focal ABI (10-16 years) and 27 healthy controls (10-16 years) completed one novel and one adapted visual emotion processing task, presented using a T120 Tobii eye-tracker. The eye-tracker measured eye-movement fixations in three areas of interest (AOIs; eyes, nose, mouth), as participants viewed the stimuli. Emotion perception accuracy was recorded. All participants from the ABI group also completed neuropsychological assessment of their immediate visual memory, visual attention, visuospatial abilities, and everyday executive function. The results of the study showed no significant difference in accuracy between the ABI and control groups. However, on average children with ABI appeared slightly less accurate than the control group in both emotion recognition tasks. Within-subjects analysis revealed no effect of lesion location and laterality or age at lesion onset upon emotion recognition accuracy. Eye tracking analysis showed that children within the ABI group presented with an atypical pattern of eye movements relative to the control group, demonstrating significantly greater fixation times within the eye region, when viewing disgusted, fearful angry and happy faces. The ABI group also showed reduced mean percentage fixation duration within the nose and mouth regions, relative to controls. Furthermore, it was observed that the ABI group took longer on average to give an accurate response to sad, disgusted, happy and surprised faces and this difference reached statistical significance for the accurate recognition of happy and surprised faces. It is suggested that the atypical fixation patterns noted within the ABI group, may represent a difficulty with dividing visual attention rapidly across the whole of the face. This slowing may have an impact upon functioning in everyday social situations, where rapid processing and appraisal of emotion is thought to be particularly important. It is therefore suggested that eye tracking technology may be a valuable method for the identification of subtle difficulties in facial emotion processing, following focal ABI in childhood, and may also have an application in the rehabilitation of these difficulties in future.

Bakgrund: Traumatisk hjärnskada (THS) orsakas av våld mot huvud i samband med fallolyckor eller trafikolyckor. Varje år söker 20 000 personer vård på grund av skallskador. Vården för traumatiskt hjärnskadade patienter i Sverige skiljer sig åt, mycket beroende på avstånden som finns till specialistsjukhus, tiden och rätta åtgärder är avgörande faktorer för denna patientgrupp. Syfte: Att undersöka vikten och intensivvårdssjuksköterskors behov av rutiner i samband med vård av patienter med hjärnskador på allmänintensivvårdsavdelningar och på neurointensivvårdavdelningar. Metod: Kvalitativ studie med fokusgruppsintervjuer av tio intensivvårdsjuksköterskor som arbetar på en allmänintensivvårdsavdelning (IVA) och specialistneurointensivvårdavdelningen (NIVA). Resultat: På NIVA finns väl inarbetade rutiner och tydliga riktlinjer nedskrivna. Sjuksköterskornas upplevelse var att det fanns tillräckligt med rutiner, men några rutiner kunde utvecklas. På IVA fanns det inga nedskrivna riktlinjer och inga tydliga rutiner för att vårda denna patientgrupp. Vården och kontrollerna ordinerades av läkare som är i tjänst. Slutsats: Vården kring hjärnskadade patienter är ytterst viktigt då man ständigt måste förebygga sekundära skador/insulter. Rutiner är väl inarbetade på specialistsjukhuset, men vården börjar först på hemsjukhuset på IVA där tydliga rutiner och riktlinjer saknas. / Introduction: Traumatic brain injury caused by violence against the head during a fall or traffic accident. Each year 20000 people gets medical care because of head injuries. The care for traumatic brain injured patients in Sweden differ greatly depending on the distances available to specialist hospitals, the time and the proper measures are crucial factors in this population. Aim: The study aims to examine the importance and intensive care nurses need routines in connection with care of patients with brain injuries in general intensive care units and in neurological intensive care units. The study consists of three group interviews in a general ICU unit in Falun and specialist unit (NIVA). Method: A qualitative study with focus group interviews. Results: The results showed that the level have clear procedures and written guidelines regarding the "avoidable factors" which are well established, their experience was that there were enough procedures, but that some could continue to develop. IVA there were no written guidelines and no clear procedures to care for this population without the care and controls prescribed by the doctor who is on duty. Conclusion: The conclusion is that care about the brain-damaged patients is extremely important when you constantly have to prevent secondary injury / insults and check the "avoidable factors". Routines are well established on specialist hospital care but starts first at home hospital where the importance of working towards the same goal and have clear procedures and guidelines from the start.

Injuries to the brain are the leading cause of permanent disability and death. Survivors of acquired brain injury (ABI) experience cognitive impairments and emotional problems. These often persist into community rehabilitation and are among the most significant needs for those in chronic stages of rehabilitation. There is a dearth of research providing evidence of music therapy addressing cognitive deficits and emotional needs in a holistic approach. This research answers the question how can brief group music therapy address cognitive functional gains and emotional needs of people with acquired brain injury. A mixed methods design was used to investigate the effect of 16 sessions of weekly group music therapy on attention and memory impairments, and emotional needs of ten ABI survivors in community rehabilitation. Quantitative data were collected to determine the effect of treatment on attention and memory functioning, mood state, and the satisfaction of emotional needs. Qualitative data were collected to reveal survivors’ experiences of brain injury and brief group music therapy. Analysis of the data showed that the intervention improved sustained attention (p<.05, r=.80) and immediate memory recall (p>.05, r=.46), and that the effect of treatment increased with dosage. Overall, the intervention was more effective than standard care, and cognitive functional gains continued after treatment for some ABI survivors. The intervention addressed emotional needs of feeling confident (p<.05, d=.88), feeling part of a group (p<.05, d=.74), feeling productive/useful (p<.05, d=.90), feeling supportive (p<.05, d=.75), feeling valued (p<.05, d=.74), and enjoyment (p<.05, d=.34). Improvements in these domains were observed in the immediate term and over the course of therapy. Music therapy enabled emotional adjustment through the development of selfawareness and insight. This study offers a music therapy method to deliver a holistic approach in rehabilitation. It demonstrates that music therapy can provide a cost effective, holistic treatment for ABI survivors.

Background: Child maltreatment is a serious health concern in the United States (U.S.) affecting as many as one in four children throughout their lifetime (Finkelhor, Turner, Ormond, & Hamby, 2013). In 2013, a reported 678, 932 victims of child maltreatment were reported to Child Protective Services (CPS), and of those cases 1,520 were fatal (CDC, 2015a). Out of all the various types of child maltreatment, Shaken Baby Syndrome (SBS) is the leading cause of child abuse deaths in the U.S. (CDC, n.d.). While current research has focused on validating the effectiveness of educational interventions, very few studies have analyzed the efficacy of individualized, patient-centered action plans. Such data would be beneficial to assess the usefulness of action plans in preparing caregivers for coping with an inconsolable infant at home. Purpose: To enhance caregiver knowledge about SBS and to provide parents with the skills and resources necessary to cope effectively and efficiently at home when unable to console their infant. Methods: This study utilized a quasi-experimental pre-test/post-test design. Participants were recruited from the Franciscan Women’s Health Associates located at St. Joseph Medical Center in Tacoma, Washington and were members of the Centering prenatal groups. The entirety of the study was completed during these groups including the pre-test, intervention, action plan, and post-test. Data was analyzed through the utilization of descriptive statistics as well as a paired t test. Results: Overall, results revealed that participant (n=26) knowledge significantly improved after the educational intervention (p=0.000) with a mean score of 87.56% on the pre-test and a mean score of 95.38% on the post-test. In addition, a majority of participants (57.5%) found both the action plan and the education to be extremely useful. Discussion: The results of this study were consistent with current evidence indicating that education on SBS, the dangers of shaking, and healthy coping mechanisms significantly impacts caregiver knowledge. In addition, a majority of participants viewed the action plans favorably identifying that they would be beneficial if they felt frustrated. Future research is warranted to gather more information on the long-term outcomes of educational interventions as well as individualized action plans.

Blast wave induced traumatic brain injury (bTBI) is a modality of injury that has come into prominence at the current time due to the large number of military and civilian personnel who have experienced the localized shock wave produced by explosive devices. The shock wave will travel concentrically outward from the explosive center, being absorbed and transmitted thru soft objects, such as tissue, and reflecting off stationary obstructions. Transmission and absorption in tissues can result in a number of physiological measureable injuries, the most common of which being what is frequently called “blast lung”. Blast lung involves the spalling effect at air-tissue interfaces. Another documented effect involves the asynchronous motion of tissue, particularly in the cranium, as the shock wave passes by. This predominately manifests itself in what is believed to be diffuse axonal injury and initiation of secondary injury mechanism. This study is designed to explore the relationship between shock waves and bTBI. A blast device was constructed for generating a free field shock wave through the high pressure rupture of a polycarbonate membrane. Air pressure in a small chamber is increased to a value several orders of magnitude greater than ambient air pressure and is held in place with the polycarbonate member. At the rupture of this membrane a shock wave is created. Measurements of this blast event, carried out with a piezoelectric pressure transducer, have shown that this shock wave is reproducible for the different membrane materials tested and is symmetrical with respect to the central axis of the high pressure chamber and exit nozzle. Having characterized the shock wave properties in the blast field, a location was chosen at which maximum shock wave pressure could be applied to the cranium for inducing bTBI. Experiments involving blast wave exposure were performed on two separate groups of animals in an attempt at establishing injury. One group was placed at a fixed distance directly below the blast nozzle, thereby experiencing both the shock wave and the associated air blast from the residual air in the chamber, and one placed at a defined distance off-axis to avoid the air blast, yet receiving two sequential blast exposures. All animal studies were approved by the VCU Institutional Animal Care and Use Committee. The degree of injury was then assessed with the use of magnetic resonance imaging (MRI) and spectroscopy (MRS). Image Data was acquired on a 2.4 Tesla magnet for assessing changes in either the total percent water concentration or the apparent diffusion coefficients (ADC) of selected regions of interest in the brain of rats. Localized proton spectroscopic data was acquired from a voxel placed centrally in the brain. The baseline values of these parameters were established before the induction of bTBI. After the blast exposure, the animals were followed up with MRI and MRS at defined intervals over a period of one week. The first group of animals received blast exposure directly underneath the blast device nozzle and the MR data does suggest changes in some of the measureable parameters from baseline following blast exposure. This blast wave data though is confounded with additional and undesirable characteristics of the blast wave. The second group of animals that received a pure shock wave blast exposure revealed no remarkable changes in the MR data pre- to post- blast exposure. The percent water concentration, ADC and spectroscopic parameters were for statistical purposes identical before and after the blast. The resolution of this negative result will require reconsideration of the free field blast exposure concept.

Traumatic brain injury (TBI) affects 3 out of every 1000 Americans each year, and is the leading cause of morbidity and mortality after trauma, accounting for as many as 56,000 deaths per year (Dutton and McCunn, 2003). The Centers for Disease and Control and Prevention found that TBI most commonly occurs in adolescents and young adults aged from 15 to 24 years and in the elderly (75 years and older). Following injury, the secondary injury begins almost immediately after the primary injury and is the result of a number of cascades where once activated, exacerbate the already altered homeostasis of the injured brain. Brain trauma leads to complex secondary injury responses that trigger many cellular and molecular pathways, especially inflammation. The cerebral inflammation that occurs after TBI has been described through the processes of glial activation followed by leukocyte recruitment, and upreglation and secretion of cytokines and chemokines. With aging there is a decrease in the production of anti-inflammatory cytokines along with increasing amounts of pro-inflammatory cytokines by peripheral blood monoculear cells, microglia, and astrocytes. Studies have shown that inflammation has a strong negative effect on neurogenesis in the adult brain due to the impact of the pro-inflammatory cytokines that are released following the acute injury or disease. In this study, we first examined the differences in glial cells responses in young adult brain and aged brain following a moderate lateral fluid percussion injury and the correlation of glial cell activation with hippocampal neurogenesis. We then examined the effect of anti-inflammation treatment on glial cell response in the young and aged brain. The levels of astrocytic and microglial responses in the DG of the hippocampus following injury at 3, 7 or 28 days post-injury were measured using densitometry image analysis on GFAP or Iba1 immunofluorescent labeled brain tissue sections. We found that injury increased both astrocyte and microglial activation and proliferation in both young and aged brain. The young injured animals exhibited greater levels of GFAP while the aged injured animals exhibited greater levels of Iba1 expression at all three time points. We also found that short time anti-inflammatory treatment with minocycline decreased levels of Iba1 expression while increased levels of GFAP expression in both young and aged brain following injury. Our data suggests that there are differences in glial response in the injured young and aged brain that may contribute to the differences in the regenerative and recovery potential in the two age groups following injury.

Traumatic brain injury (TBI) is a worldwide epidemic as the number of victims living with the resulting cognitive and physical impairment continues to rise, principally due to limited treatment options which fail to address its multifaceted sequelae. By approaching TBI therapy from a molecular standpoint, we have the opportunity to develop a better understanding of the mechanisms which prevent effective recovery. With this information, we can move toward the identification of novel therapeutic treatments which target specific molecules to improve patient outcome following TBI. Here, we have focused on the therapeutic potential of osteopontin (OPN), an extracellular matrix (ECM) protein which is a substrate of several matrix metalloproteinases (MMPs), and capable of acting as both a cytokine and modulator of axonal outgrowth during synaptic recovery. The ECM and its components are of particular interest with respect to selecting novel TBI therapeutics since this network has been implicated in neuronal plasticity during both development and following central nervous system (CNS) insult. In this dissertation study, the temporal and spatial profile of OPN expression, its protein and transcript localization within reactive glia (IBA1 positive microglia or GFAP positive astroglia), and its interaction with the cytoarchitectural protein (microtubule associated protein 1B, MAP1B) after injury were each compared under conditions of deafferentation induced synaptogenesis. Two TBI models were employed: one exhibiting adaptive synaptic plasticity (unilateral entorhinal cortex lesion, UEC), and the other generating maladaptive synaptic plasticity (central fluid percussion injury followed by bilateral entorhinal cortex lesions, TBI+BEC), in each case targeting 1, 2, and 7d postinjury intervals. In addition, we examined the potential for converting the adaptive response to one of maladaptive plasticity by attenuating immune reactivity through acute administration of the tricyclic antibiotic minocycline, utilizing a dosing paradigm previously demonstrated to reduce inflammation. To more clearly confirm that OPN has a role in successful synaptic regeneration, we developed a colony of OPN knockout (KO) mice which were used to profile synaptic structure and functional outcome under conditions of UEC-induced synaptogenesis. In Chapter 2, we report that full length OPN responds robustly in the acute (1-2d postinjury) degenerative period following UEC and TBI+BEC. After UEC, time-dependent differences were observed for two alternative, MMP-processed OPN forms, including early increase in a RGD 45 kD, integrin binding fragment (1d), and delayed increase in a C-terminal 32 kD OPN peptide (7d). OPN transcript was also elevated acutely after UEC, a finding which was pronounced in enriched dentate molecular layer (ML) fractions. Parallel immunohistochemistry (IHC) and in situ hybridization localized OPN protein and transcript to reactive glia following UEC. This localization was concentrated within microglia which delineated the border between the intact and deafferented ML, a pattern which was less pronounced in maladaptive TBI+BEC animals. The timing of this glial movement suggests that OPN regulates microglial migration and, potentially, could act as an astrokine to recruit activated astrocytes for influencing subsequent synaptic regeneration. MAP1B staining confirmed dendritic loss during axonal degeneration and dendritic atrophy, with a reemergence during collateral axonal sprouting. However, OPN colocalization with MAP1B was minimal, suggesting a minor role for OPN in reorganization of dendritic/axonal cytoarchitecture in this model of deafferentation. Minocycline reduced acute OPN protein response 2d after UEC, and caused a more random OPN positive glial distribution, similar to that of the maladaptive TBI+BEC. The role of OPN in the inflammation-directed degeneration of terminals is supported by reduced MMP-9 activity, which is temporally correlated with the reduction of MMP-generated OPN lytic fragments (45 kD). Interestingly, this reduction of integrin-binding OPN peptide also matched the impaired removal of presynaptic terminals, evidenced by diminished synapsin 1 clearance in animals which received postinjury minocycline. In Chapter 3, we sought to more precisely evaluate the role of OPN following deafferentation, utilizing wild type (WT) C57BL/6 and OPN KO mice subjected to UEC, comparing the spatio-temporal injury response between WT and KO. To do this we profiled several outcome measures which assessed OPN role in different aspects of recovery: 1) expression of select proteins important in various stages of synaptic recovery, 2) glial response, 3) cognitive recovery, and 4) MMP enzymatic activity. Compared to WT mice, OPN KO mice did not show significant differences in the acute injury-induced alteration of proteins important to cytoarchitectural reorganization (MAP1B) or stabilization of the synaptic junction (N-cadherin). However, both Western blot and IHC analyses showed OPN KO mice had impaired presynaptic terminal clearance, supported by attenuated synapsin 1 breakdown, a result quite similar to that of the minocycline-treated rats with OPN reduction in Chapter 2. This impaired degeneration in OPN KO mice at 2d postinjury correlated with IHC evidence for altered microglial morphology, and hippocampal function assessed by the novel object recognition (NOR) task. Our NOR results confirmed cognitive dysfunction in OPN KO mice during the 4-21d period of synapse reorganization after UEC. In addition, OPN KO decreased MMP-9 activity, an effect associated with reduced MMP-9 bound lipocalin 2 (LCN2), a persistently activated form of that MMP. These latter findings further support the hypothesis that MMP processing of OPN contributes to effective regenerative response after injury. Collectively, the studies presented in the two chapters of this dissertation provide evidence that OPN is a critical element in the acute immune response following injury-induced CNS deafferentation. They suggest that the cytokine can be produced by reactive microglia, may mediate cell migration and acute degenerative clearance, potentially serves as an astrokine to recruit those glia to sites of synaptic repair, and that these processes are disrupted when OPN is either reduced or ablated. Interestingly, this OPN role in synaptogenesis appears to involve ECM interaction with MMP-9, possibly regulated by LCN2. Most importantly, OPN involvement seems to affect the time-dependent progression of synaptic repair, an effect which can be measured by efficacy of functional outcome

Traumatic brain injury (TBI) affects 1.5 million Americans annually and is a major health concern. Increasing evidence suggests that the brain extracellular environment regulates plasticity and synaptic recovery following TBI. Here we have focused on phosphacan/RPTPβ, an alternatively spliced group of chondroitin sulfate proteoglycans which are prominent within the mature brain extracellular matrix (ECM). Previous studies show that phosphacan/RPTPβ influences neuronal migration, adhesion, neurite outgrowth, and morphogenesis. However, our understanding of how these important ECM components are involved in recovery from brain trauma remains unclear. In the present study, we used unilateral entorhinal cortex lesion (UEC), a model which induces robust hippocampal reactive plasticity, to investigate the role(s) of phosphacan/RPTPβ isoforms in adaptive synaptogenesis after TBI. Using detailed protein and mRNA quantification, immunohistochemistry, and qualitative ultrastructural analyses, we show elevated phosphacan expression in the deafferented hippocampus at the early degenerative phase and during the subsequent period of active sprouting. By contrast, the receptor variant sRPTPβ is persistently elevated in hippocampus over the first two weeks following UEC. We have further characterized a process for validating appropriate reference genes for quantitative real-time RT-PCR studies of plasticity and recovery after TBI. From these studies we conclude that injury model, brain region, survival period and correlative protein expression are critical factors which must be considered for reference gene selection. Finally, we investigated functional implications of sRPTPβ increase during reactive synaptogenesis, showing that the sRPTPβ substrate β-catenin, an important cytoskeletal regulator, is altered in hippocampus during injury-induced plasticity. Together, these results support a role for phosphacan/RPTPβ in both degenerative and regenerative phases of reactive synaptogenesis. Phosphacan may promote adaptive plasticity at earlier post-injury phases through interactions with adhesion molecules or growth factors in the extracellular space. The prolonged increase in sRPTPβ after UEC, along with its localization at postsynaptic profiles, suggests that this isoform may work with intracellular substrates to influence spine morphogenesis and/or stabilization of new synapses. Gaining a better understanding of the roles of ECM components in recovery from TBI will be an essential part of defining the difference between injuries where recovery is successful, and those where recovery fails.