# Shear shock waves are observed in the brain

## TL;DR

This study uses advanced ultrasound imaging to directly observe shear shock waves in the brain, revealing their spontaneous formation and potential role in traumatic injuries.

## Contribution

First direct observation of shear shock waves in the brain using a novel ultrasound technique, highlighting their significance in traumatic brain injury mechanisms.

## Key findings

- Shear shock waves are spontaneously generated in the brain during impacts.
- Acceleration at the shock front is amplified up to 8.5 times.
- Shear shock waves may be a fundamental mechanism for traumatic injuries.

## Abstract

The internal deformation of the brain is far more complex than the rigid motion of the skull. An ultrasound imaging technique that we have developed has a combination of penetration, frame-rate, and motion detection accuracy required to directly observe, for the first time, the formation and evolution of shear shock waves in the brain. Experiments at low impacts on the traumatic brain injury scale demonstrate that they are spontaneously generated and propagate within the porcine brain. Compared to the initially smooth impact, the acceleration at the shock front is amplified up to a factor of 8.5. This highly localized increase in acceleration suggests that shear shock waves are a fundamental mechanism for traumatic injuries in soft tissue.