Rotational Acceleration Closed Head Flexion Trauma Generates More Extensive Diffuse Brain Injury than Extension Trauma

• Our aim was to investigate if seemingly identical head and neck trauma would generate differing types of braindamage. We experimentally evaluated induced brain injuries immediately after trauma exposure, and at 1 weekpost-injury. Anesthetized rabbits were exposed once to a sagittal rotational acceleration head and neck injury ateither a high or a low load level, using either flexion or extension. A high-load extension trauma induced scatteredmeningeal petechial hemorrhages and no deaths, in contrast to a flexion trauma of the same level, which resultedin extensive parenchymal and meningeal hemorrhages, and all animals succumbed immediately. A low-levelflexion trauma induced scattered meningeal petechiae, but no gross damage, while extension at the same forcegenerated no macroscopically visible acute brain injury. Immunohistochemical investigations carried out at 7 daysdisclosed that a low-level flexion trauma, as well as both low- and high-level extension exposures, all induceddiffuse brain injuries in the cerebral cortex and white matter, corpus callosum, hippocampus, brainstem, andcerebellum, as revealed by abnormal distribution of neurofilaments, a prevalence of b-amyloid precursor protein,and astrogliosis. The diffuse brain injury seen after a low-level flexion trauma was equal to or more extensive thanthat seen after a high-level extension trauma. A low-level extension trauma induced only minor histopathologicalabnormalities. We conclude that a sagittal rotational acceleration trauma of the head and neck induced diffusebrain injury, and that flexion caused more extensive damage than extension at the same applied load.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Neurovetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Neurosciences (hsv//eng)

Nyckelord

mild traumatic brain injury

astrocytosis

b-amyloid precursor protein

diffuse axonal injury

astrocytosis; b-amyloid precursor protein; diffuse axonal injury; mild traumatic brain injury

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art (ämneskategori)

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