New Mechanics of Traumatic Brain Injury

TL;DR

This paper introduces a new hypothesis that traumatic brain injury results from an external impulsive load called SE(3)-jolt, causing rapid brain deformations, modeled through coupled dynamics and continuum mechanics.

Contribution

It formulates a coupled loading-rate hypothesis for TBI and derives the associated dynamics using covariant force law and Cosserat continuum models, offering a novel mechanistic explanation.

Findings

SE(3)-jolt causes brain dislocations and disclinations.

Coupled Newton-Euler dynamics describe brain's micro-motions.

Cosserat continuum model captures brain's viscoelastic response.

Abstract

The prediction and prevention of traumatic brain injury is a very important aspect of preventive medical science. This paper proposes a new coupled loading-rate hypothesis for the traumatic brain injury (TBI), which states that the main cause of the TBI is an external Euclidean jolt, or SE(3)-jolt, an impulsive loading that strikes the head in several coupled degrees-of-freedom simultaneously. To show this, based on the previously defined covariant force law, we formulate the coupled Newton-Euler dynamics of brain's micro-motions within the cerebrospinal fluid and derive from it the coupled SE(3)-jolt dynamics. The SE(3)-jolt is a cause of the TBI in two forms of brain's rapid discontinuous deformations: translational dislocations and rotational disclinations. Brain's dislocations and disclinations, caused by the SE(3)-jolt, are described using the Cosserat multipolar viscoelastic continuum brain model. Keywords: Traumatic brain injuries, coupled loading-rate hypothesis, Euclidean jolt, coupled Newton-Euler dynamics, brain's dislocations and disclinations