Diffuse Axonal and Vascular Pathology in the Gyrencephalic Brain after High-Energy Blunt Injury: Clinicopathological...

Area of Science:

• Neuroscience
• Pathology
• Trauma Research

Background:

• High-energy blunt force trauma, particularly behind helmet blunt trauma (BHBT), is a poorly understood cause of traumatic brain injury (TBI).
• BHBT is frequently associated with apnea and mortality in humans, suggesting a critical role for brainstem injury.
• Characterizing neuropathologies in BHBT is crucial for understanding acute respiratory decompensation.

Purpose of the Study:

• To characterize neuropathologies in a swine model of high-energy BHBT.
• To investigate the association between these neuropathologies and acute respiratory decompensation.
• To examine the role of brainstem axonal and vascular lesions in apnea following BHBT.

Main Methods:

• Utilized a swine model subjected to high-energy BHBT.
• Euthanized animals within 4 hours post-injury for neuropathological assessment.
• Focused on axonal and vascular pathologies, particularly in the brainstem.

Main Results:

• BHBT frequently caused cranial fractures, subarachnoid hemorrhages, contusions, and diffuse axonal and vascular lesions, especially in the brainstem.
• Absence of spontaneous respiration correlated with impact severity and brainstem lesion severity.
• Diffuse axonal lesions in the medial medulla or vascular lesions in the anteroventral brainstem were linked to adverse outcomes, suggesting brainstem respiratory center involvement.

Conclusions:

• High-energy blunt force TBI induces diffuse axonal and vascular lesions associated with poor outcomes.
• Axons and blood vessels may respond differently to tissue deformation, with vascular markers not being direct surrogates for axonal injury.
• Regional brainstem injuries, both axonal and vascular, play a significant role in acute respiratory decompensation after blunt TBI, even with head protection.