Browsing by Subject "TBI"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Canadian CT Head Rule is an Effective Clinical Screening Tool in Minor Head Trauma Cases.
    (2010-11-02) Donald, Bryan
    The Canadian CT Head Rule is a simple screening tool used in cases of adults with minor head trauma. It can identify patients needing surgery 100% of the time while limiting the number of patients needing head CT to only 32% of those with minor head trauma and a loss of consciousness.
  • Thumbnail Image
    Item
    Emotion-modulated startle reactivity in OEF/OIF veterans with PTSD
    (2012-08) Goldman, Daniel Jacob
    In addition to an exaggerated startle reflex, the most commonly reported symptoms of post- traumatic stress disorder (PTSD) are intense physiological reactivity and psychological distress, respectively, on exposure to cues that symbolize or resemble an aspect of the traumatic event. While the presence of an objectively measured exaggerated startle reflex in PTSD is firmly established, questions regarding when it is exhibited and what it tells us about the disorder remain unanswered. Furthermore, the data on emotion-modulated startle reactivity in PTSD are especially unclear and need further exploration. This is in large part due to a surprising paucity of data in the literature, as well as the interrelated problems of within-category heterogeneity and diagnostic comorbidity. Given that emotion-modulated startle is such a well-validated measure of emotional processing and defensive system reactivity, the lack of knowledge on this startle blink parameter is striking. The current study explored emotion-modulated startle reactivity in PTSD by investigating startle responses to pleasant, neutral, unpleasant, and trauma-related picture stimuli. Additional information regarding emotional dysregulations in PTSD was obtained through analyses of facial EMG, skin conductance, and heart rate responses. Both categorical (i.e., PTSD vs no-PTSD) and dimensional (i.e., specific symptom cluster) analyses were conducted in order to develop psychophysiological models and measures of the emotional dysregulations in PTSD. Contrary to expectations, categorical comparisons of individuals with and without PTSD did not yield a clear pattern of fruitful differences on any psychophysiological measure other than heart rate. In categorical comparisons, there was no strong indication for a particular physiological model for emotional dysregulations in PTSD and present results provide very little support for the presence of an objectively-measured exaggerated startle response in PTSD. However, significant relationships between most specific symptom clusters and the startle blink response were observed. The same was true for subjective ratings of the affective valence and arousal of the picture stimuli. Unexpectedly, the most consistent effects were for diminished emotion modulation to pleasant stimuli rather than exaggerated responding to unpleasant or trauma-relevant stimuli. Current results suggest that PTSD is not defined by an abnormality in fear and that an underappreciated and central aspect of PTSD is a limited capacity for positive affect. Implications regarding the coherence of the construct of PTSD as defined in DSM-IV are discussed.
  • Thumbnail Image
    Item
    Greed-OxyContin-Addiction-Death
    (2022) Hilleboe, Cody J
    A supporting paper to fulfill the Master of Fine Arts degree requirements Submitted to the Graduate Faculty of the Department of Art University of Minnesota By Cody Hilleboe In partial fulfillment of the requirements of the Master of Fine Arts Degree in Art 2022 Committee: Rotem Tamir Christina Schmid Emily Jordan Jensen Tetsuya Yamada
  • Thumbnail Image
    Item
    N-back Performance with Trauma-Relevant Visual Distractors: Associations with Posttraumatic Stress Symptomatology
    (2018-09) Marquardt, Craig
    Responses to psychological trauma can range widely from resiliency to psychiatric disability. Posttraumatic stress disorder (PTSD) is one possible outcome following trauma composed of specific symptoms such as intrusive re-experiencing of trauma reminders, avoidance of trauma-related cues, dysphoric mood, and hyperarousal. The existence of PTSD-related cognitive impairments is well documented, but the contributory factors behind these effects are less understood. Questions about cognitive functioning are relevant for recently returning military service members who commonly report past neurological sequelae consistent with mild traumatic brain injury (mTBI) from explosive blasts. There is interest in using laboratory paradigms to tease apart the relative effects of PTSD and mTBI. The attentional control theory proposes misallocations of attentional resources are responsible for cognitive alterations among individuals with anxiety-related disorders. Elevated anxiety may lead to perceptual engagement with task-irrelevant threat, which would require goal-directed attentional resources to inhibit and shift back towards primary task goals. In this way, task effectiveness can be maintained at the cost of inefficiently slowed responding. A cross-sectional sample of veterans from Operations Enduring/Iraqi Freedom (OEF/OIF) were recruited (n = 128) to complete a sequential-letter N-back task superimposed over task-irrelevant neutral images or affectively aversive combat scenes. Consistent with the attentional control theory, individuals with elevated symptoms of PTSD were more inefficient while task efficacy was largely preserved. Response time (RT) variability indices assessing the relative prominence of goal-directed decisional processes failed to produce associations with PTSD. Instead, inefficient cognition was best explained by general psychopathology effects and prolonged engagement with threat by non-decisional mental processes. Event-related potentials (ERPs) to the onset of the task stimuli supported the RT findings. Specific alterations in early engagement with stimulus-driven attentional processing were observed among individuals with elevated PTSD symptomatology. Two-step temporal-spatial decompositions of the ERPs did not reveal any PTSD effects specific to an identified central spatial component. Instead, effects of PTSD were best explained as alterations in perceptual processing most clearly observed within neural activity at a posterior spatial component. Effects of mTBI were isolated to the behavioral indices and resulted in more rather than less efficient engagement with the task. Several key aspects of the attentional control theory were not supported by the results. Alterations in goal-directed attentional systems may not be strictly necessary to produce PTSD-related cognitive inefficiencies. Study findings have implications for alternative models of PTSD using dimensional symptom severity scores.