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

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.

published_or_final_version / Clinical Psychology / Master / Master of Social Sciences

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There is a paucity of research into traumatic incidents concerning police workers (Hart et al. 1995). There are also few studies relating the prolonged and repetitive exposure to traumatic stressors, or 'sequential trauma' (Gersons and earlier 1990; 1992). Whilst it was acknowledged that organisational stress contributes to adaptive or maladaptive well being, dependent on transactional variables between the person and their environment, it was also argued that further along the stress continuum, there exists gross stress reactions similar to Post Traumatic stress Disorders (PTSD; DSM-IIIR; American Psychiatric Association 1989) and newly revised PTSD criterion (DSM-IV; American Psychiatric Association 1994). However PTSD exclusively relates to a single event of overwhelming magnitude (Davidson and Foa 1991), whilst sequential trauma relates to mUltiple event exposure (Peters-Bean 1990b; 1996). It was argued that the magnitude of stimuli in trauma is not as important as the management of the trauma. Rather trauma is an artefact of person-environment transactions and the operation of 'traumatic signatures' which can be used adaptively or maladaptively in certain scenarios. Models of sequential trauma were proposed and tested. These notions are discussed in relation to three studies: an interview booklet survey (N=89); a Metropolitan Police Survey (N=134) and a Main U.K. Forces Survey (N=528) Results and implications for police workers and further research was discussed. It was found that trauma signatures may possibly assist in the processes involved with encountering trauma, primary and secondary appraisal mechanisms, coping post-event and physiological and psychological well-being with reference to individual and organisational outcomes.

The purpose of this study was to investigate post-traumatic stress disorder among Guatemalan and Salvadoran refugees living in Tucson, Arizona. The questions that guided the study were: (1) Does post-traumatic stress disorder exist among Central American refugees living in Tucson? (2) If so, how does it manifest itself in this population? (3) What counseling or other therapeutic interventions may be helpful for Central Americans experiencing post-traumatic stress disorder? Six Guatemalan and Salvadoran refugees who had reportedly experienced major stressors participated in a semi-structured interview and responded to a health questionnaire based upon post-traumatic stress disorder symptoms. Findings indicate that five out of six participants were experiencing patterns of stress-induced symptoms which were consistent with a DSM III diagnosis of "Post-Traumatic Stress Disorder". Recommendations for intervention with Central American individuals experiencing post-traumatic stress disorder are presented.

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