The influence of dynamic response and brain deformation metrics on the occurrence of subdural hematoma in different regions of the brain

Abstract

Object The purpose of this study was to examine how the dynamic response and brain deformation of the head and brain—representing a series of injury reconstructions of which subdural hematoma (SDH) was the outcome—influence the location of the lesion in the lobes of the brain. Methods Sixteen cases of falls in which SDH was the outcome were reconstructed using a monorail drop rig and Hybrid III headform. The location of the SDH in 1 of the 4 lobes of the brain (frontal, parietal, temporal, and occipital) was confirmed by CT/MR scan examined by a neurosurgeon. Results The results indicated that there were minimal differences between locations of the SDH for linear acceleration. The peak resultant rotational acceleration and x-axis component were larger for the parietal lobe than for other lobes. There were also some differences between the parietal lobe and the other lobes in the z-axis component. Maximum principal strain, von Mises stress, shear strain, and product of strain and strain rate all had differences in magnitude depending on the lobe in which SDH was present. The parietal lobe consistently had the largest-magnitude response, followed by the frontal lobe and the occipital lobe. Conclusions The results indicated that there are differences in magnitude for rotational acceleration and brain deformation metrics that may identify the location of SDH in the brain.

Characterization of persistent concussive syndrome using injury reconstruction and finite element modelling

“…The Neurotrauma forms were hardcopy or electronic documents that were used as a standardized method to collect the impact parameters of the event for laboratory reconstruction purposes (Post et al, 2014;Post et al, 2014). These forms were filled in by the neurosurgeon or research assistant based on interviews with the patients involved.…”

“…The MADYMO simulations were conducted based upon the initial body positions of the subject based on the Neurotrauma report form and the slip, or trip that resulted in the fall (Figure 4) (Adamec et al, 2010). A series of MADYMO simulations were conducted for each fall case to determine the upper and lower boundaries for velocity for the Hybrid III impact reconstructions Post et al, 2014). …”

“…From a biomechanical perspective, brain injury, be it transient concussion or PCS, is likely linked to the characteristics of the event that caused the injury . These characteristics have been defined in the past as combinations of mass, velocity, location of impact, and others that determine the stresses and strains in the brain tissue Post et al, 2014;Karton et al, 2013). These brain injuries likely cause a complex series of cellular events that result in the symptomology associated with PCS (Giza and Hovda, 2001).…”

“…There has been some theories put forward suggesting that there is a continuum, or hierarchy, of brain injury Post et al, 2014). In the past researchers have shown that it is likely that no injury would be at the low ranges of head impact injury, followed by concussion, and finally TBI .…”

“…In the past researchers have shown that it is likely that no injury would be at the low ranges of head impact injury, followed by concussion, and finally TBI . However, recently there has been suggestions that within each of these brain injury categories (concussion and TBI) there is a further continuum that may be influenced by factors related not only to the increasing energy of impact, but to the characteristics of the event and how that affects the mechanisms of injury attached to particular anatomical structures Post et al, 2014). While it is likely that severity of impact may affect the occurrence of PCS, the characteristics leading to this type of injury have not been examined or in any way quantified.…”