Journal of neurotrauma
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Journal of neurotrauma · Dec 2024
Diffuse Axonal and Vascular Pathology in the Gyrencephalic Brain after High-Energy Blunt Injury: Clinicopathological Correlations Involving the Brainstem.
Traumatic brain injury (TBI) after high-energy, behind helmet blunt trauma (BHBT) is an important but poorly understood clinical entity often associated with apnea and death in humans. In this study, we use a swine model of high-energy BHBT to characterize key neuropathologies and their association with acute respiratory decompensation. Animals with either stable or critical vital signs were euthanized within 4 h after injury for neuropathological assessment, with emphasis on axonal and vascular pathologies in the brainstem. ⋯ Our findings indicate that high-energy, blunt-force impact TBI causes diffuse lesions in axons and blood vessels associated with poor outcomes. They also suggest that axons and vessels may have distinct responses to tissue deformation and that commonly used markers of vascular pathology, for example, in diagnostic radiology, cannot be used as direct surrogates of diffuse axonal injury. In concert, our study underscores the role of regional axonal and vascular injuries in the brainstem in acute respiratory decompensation after high-rate blunt TBI, even in the presence of head protection; it also emphasizes the importance of detailed clinicopathological work in complex brains in the field of TBI.
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Journal of neurotrauma · Dec 2024
Vasomotion and Cerebral Blood Flow in Patients With Traumatic Brain Injury and Subarachnoid Hemorrhage: Cerebrovascular Autoregulation Versus Autonomic Control.
This study compared the roles of extraparenchymal autonomic nervous system (ANS) control of cerebral blood flow (CBF) versus intraparenchymal cerebrovascular autoregulation in 487 patients with aneurysmal subarachnoid hemorrhage (SAH) and 413 patients with traumatic brain injury (TBI). Vasomotion intensity of extraparenchymal and intraparenchymal vessels were quantified as the amplitude of oscillations of arterial blood pressure (ABP) and intracranial pressure (ICP) in the very low frequency range of 0.02-0.07 Hz, or periods of 55-15 sec, computed with a bandpass filter. A version of the pressure reactivity index (PRx-55-15) was computed as the correlation of the filtered waveforms, ABP-55-15 and ICP-55-15. ⋯ CBF in patients with TBI is more reliant on cerebrovascular autoregulation based on metabolic demand. This appears to be deficient following SAH, making the heightened ANS support necessary. Although this support is beneficial, it does not fully compensate for the loss of cerebrovascular autoregulation, as reflected in the problems in the SAH cohort with delayed cerebral ischemia and poor outcome.
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Journal of neurotrauma · Dec 2024
The Co-Occurrence of Vestibular/Ocular Motor Provocation and State Anxiety in Adolescents and Young Adults with Concussion.
Vestibular/ocular motor provocation and state anxiety are both independently linked to poor recovery outcomes following concussion. However, the relationship between these two clinical presentations and their co-occurring effects on concussion recovery outcomes is understudied. The purpose was to examine the co-occurring effects of vestibular/ocular motor provocation and state anxiety following concussion. ⋯ Participants exhibiting vestibular/ocular motor provocation with clinical levels of state anxiety were at 2.47 times (p < 0.001, 95% CI: 1.53-3.99) greater odds of experiencing a protracted concussion recovery than participants with vestibular/ocular motor provocation without clinical state anxiety. Vestibular/ocular motor provocation is associated with increased state anxiety following concussion, and the addition of clinical state anxiety to vestibular/ocular motor provocation increases the odds for protracted recovery. Clinicians should assess vestibular/ocular motor function and anxiety following concussion.
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Journal of neurotrauma · Dec 2024
Characterizing the Effect of Repetitive Head Impact Exposure and mTBI on Adolescent Collision Sports Players' Brain with Diffusion Magnetic Resonance Imaging.
Athletes in collision sports frequently sustain repetitive head impacts (RHI), which, while not individually severe enough for a clinical mild traumatic brain injury (mTBI) diagnosis, can compromise neuronal organization by transferring mechanical energy to the brain. Although numerous studies target athletes with mTBI, there is a lack of longitudinal research on young collision sport participants, highlighting an unaddressed concern regarding cumulative RHI effects on brain microstructures. Therefore, this study aimed to investigate the microstructural changes in the brains' of high school rugby players due to repeated head impacts and to establish a correlation between clinical symptoms, cumulative effects of RHI exposure, and changes in the brain's microstructure. ⋯ Repeated head impacts during a rugby season may adversely affect the structural organization of the brain's white matter. The observed diffusion changes, closely tied to SCAT5 symptom burden, stress the profound effects of seasonal head impacts and highlight individual variability in response to repetitive head impact exposure. To better manage sports-related mTBI and guide return-to-play decisions, comprehensive studies on brain injury mechanisms and recovery post-mTBI/RHI exposure are required.
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Journal of neurotrauma · Dec 2024
Detecting Mild Traumatic Brain Injury after Combat Deployment: Agreement Between Veterans Health Administration Clinical System and LIMBIC-CENC Research Protocol.
Identifying historical mild traumatic brain injury (TBI) is important for many clinical care reasons; however, diagnosing mild TBI is inherently challenging and utility of screening is unknown. This study compares a standardized research process to an established clinical process for screening and diagnosis of historical mild TBI during combat deployment in a military/Veteran cohort. Using validated instruments, the Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) prospective longitudinal study (PLS) screens for all potential concussive events (PCEs) and conducts structured concussion diagnostic interviews for each PCE. ⋯ Significant characteristics of PLS-positive/VHA-negative mismatches included demographic variables, military service variables, and current symptom levels. Further research is needed to better understand whether there is a clinical value to adjust the VHA TBI screening process and how these characteristics could be considered. Providers should be aware that some Veterans may have undocumented, positive mild TBI histories even if they underwent screening and/or CTBIE processes.