Simulation of acute subdural hematoma and diffuse axonal injury in coronalhead impact

Coronal head impacts were simulated in a physical model, based on the hypot hesis that acute subdural hematoma (ASDH) is related to cerebral vertex dis placement and diffuse axonal injury (DAI) to local Green-Lagrange strain. T he geometry of the 2D model was based on anatomical measurements taken from the MRI scans of 10 adult males. Silicone gel modelled the cerebrum, paraf fin the CSF and elastic membranes the trabeculae of the sulci. Pendulum imp acts gave peak angular acceleration of 7800 rad s (- 2) in models with and without sulci. The motion of the gel and Green-Lagrange strain were calcula ted from tracked coordinates of Patrick markers. Worst-case bridging vein s trains are produced on the contrecoup side and are approximately doubled by adding sulci. Given that axons in the corpus callosum are highly oriented, Green-Lagrange strain was resolved in the fibre direction. It is found to be close to the minimum principal strain, indicating a degree of natural, t eleological protection for the axons. The data support the use of Delta (0) over dot (peak) as a suitable descriptor for the risk of DAT but not for A SDH. (C) 2000 Elsevier Science Ltd. All rights reserved.