Diffuse axonal injury is best described as ...

Diffuse axonal injury is best described as ...

• A. Injury caused by acceleration/deceleration leading to microscopic tears of nerve fibers, often resulting in loss of consciousness.
• B. Direct cortical contusion due to blunt trauma
• C. Shearing of neurons due to vasogenic edema
• D. Focal epidural hematoma formation

Answer: (A)

Diffuse axonal injury occurs when rapid brain movement—acceleration and deceleration—stretches and tears axons across widespread white-matter tracts. This shearing disrupts the brain’s communication pathways, so transmission of signals is impaired, which is why patients often have immediate or prolonged loss of consciousness after blunt head trauma. Unlike focal injuries, there isn’t a single contusion or a discrete mass lesion; imaging may be normal early on, though MRI can show tiny hemorrhages at the gray–white matter junction or in the corpus callosum and brainstem as evidence of the diffuse injury. Edema can accompany the injury, but the defining feature is the microscopic axonal tearing from the mechanical shear forces, not a localized cortical contusion, a focal epidural hematoma, or edema-driven damage.

Diffuse axonal injury occurs when rapid brain movement—acceleration and deceleration—stretches and tears axons across widespread white-matter tracts. This shearing disrupts the brain’s communication pathways, so transmission of signals is impaired, which is why patients often have immediate or prolonged loss of consciousness after blunt head trauma. Unlike focal injuries, there isn’t a single contusion or a discrete mass lesion; imaging may be normal early on, though MRI can show tiny hemorrhages at the gray–white matter junction or in the corpus callosum and brainstem as evidence of the diffuse injury. Edema can accompany the injury, but the defining feature is the microscopic axonal tearing from the mechanical shear forces, not a localized cortical contusion, a focal epidural hematoma, or edema-driven damage.