Military personnel often experience mild traumatic brain injury (mTBI) from exposure to improvised explosive devices (IEDs). Soldiers typically endure blast trauma from the IED pressure wave as well as blunt trauma from ensuing head impacts. Researchers have not reached a consensus on whether the biomechanical response from blunt or blast trauma plays a more dominant role in mTBI because the specific biomechanical sources of injury are often undetermined. Consequently, the goal of this dissertation was to conduct three separate studies in order to characterize the mechanical behavior of the brain after exposure to mTBI conditions. For Study 1, mild blunt and blast trauma were induced in Sprague-Dawley rats using a custom-built device. In-house diffusion tensor imaging (DTI) software was used to make 3-D reconstructions of white matter fiber tracts before and after injury (1, 4, and 7 days). Axonal integrity was characterized by examining the fiber count, fiber length, and fractional anisotropy (FA). In-house image analysis software also quantified the microstructural variations in Hematoxylin and Eosin (H&E) stained brain sections, where significant differences in parameters such as the area fraction (AF) and nearest neighbor distance (NND) correlated to voids that formed after water diffused extracellularly from axons. Study 2 employed a computational approach involving the development of a finite element (FE) model for the rat head followed by the simulation of blunt and blast trauma, respectively. FE parameters such as von Mises stress, pressure, and maximum principal strain were analyzed at various locations including the skull, cerebral cortex, corpus callosum, and hypothalamus to compare injury cases. Study 3 involved interruption mechanical testing of porcine brain, a suitable animal surrogate of human brain. Compression, tension, and shear experiments were performed at a strain rate of 0.1 s-1 to examine the differential mechanical response. Microstructural changes in H&E stained brain sections were analyzed with in-house image analysis software to quantify differences among stress states at strains of 0.15, 0.30, and 0.40. Studies 1 and 2 confirmed that the brain behaves differently in response to blunt and blast trauma, respectively, while Study 3 further demonstrated the stress state dependent behavior of brain tissue.

Mild traumatic Brain Injury (mTBI or Concussion) is an increasingly common public health issue in sports, military environments, and life in today’s active world. Despite a great deal of study and public attention to this disorder, knowledge about optimal diagnostic, prognostic, and treatment information remains lacking. Neurosensory symptoms have been shown to be the most frequent complications of mTBI in both the acute and chronic setting. Neurosensory Disorders in Mild Traumatic Brain Injury brings together both the basic science work as well as the clinical work in mTBI into one volume to provide a comprehensive examination of the neurosensory issues associated with this disorder. Coverage includes chapters on defining mild Traumatic Brain Injury, neurosensory consequences, neurosensory disorders in clinical practice, and diagnosis and treatment for neurosensory disorders in mTBI. This book is written for clinicians, researchers, residents and students in neurology and neuroscience. Provides a comprehensive examination of the neurosensory issues associated with mild Traumatic Brain Injury and concussion Brings together both the basic science work and the clinical work in mTBI into a single volume Helps clinicians understand the best diagnosis and treatment paths and puts current research into perspective for researchers

There is increasing concern over the common, repetitive forms of blast to which military members are exposed during service, and how those exposures could affect the central nervous system. The authors of this report review the relevant literature.

Otolaryngology Head and Neck Surgery is the medical and surgical specialty addressing disorders of the head and neck in both adult and pediatric populations. The goal of the encyclopedia is to serve as a single and comprehensive source of all the information that is essential for students and practitioners of the specialty. The vast amount of information included in the encyclopedia is divided into 5 volumes in line with the subspecialties of general otolaryngology, head and neck surgery, pediatric otolaryngology, otology–neurotology, and facial plastics. All volume editors are internationally recognized otolaryngologists with experience in publishing. Each section editor recruited experienced authors from all over the world to contribute on structured topics, and all entries are supported by published references. Thus, all information included in the encyclopedia is from credible sources and has been carefully screened for accuracy. The strength of the encyclopedia is its online availability and quick search features, which allow rapid retrieval of definitions and more in-depth information. Key words are hyperlinked to provide a gateway to numerous referenced manuscripts, journals, and books.

Organized for easy reference, this comprehensive, concise, and clinically focused text covers all aspects of emergency medicine. Chapters follow a consistent, structured format—clinical presentation, differential diagnosis, evaluation, management, and disposition with highlighted critical interventions and common pitfalls. In this edition, the Pain and Pain Management section is now at the front of the book, since a large percentage of emergency department patients present with pain-related complaints. The Trauma section now follows the High-Risk Chief Complaint section. A new two-color design will help readers find critical elements of each chapter easily. A companion Website will include the fully searchable text, more than 400 self-assessment questions with answers, and additional images and tables.