Development of a Novel Technology-Based Biomarker for Identification of Mild Brain Injury

Dr. Magdalena Ietswaart, University of Stirling

Using cortico-spinal excitability as a biomarker for identifying mild traumatic brain injury

Mild traumatic brain injury is difficult to diagnose. What is lacking is a reliable physical measure or biomarker of neural change following events such as a blow to the head. Because mild traumatic brain injury is common, it is important that such sensitive, objective, and repeatable diagnostic tools are developed. This project aims to establish a neural biomarker by measuring the ease with which a neural impulse travels from the brain to the muscle it controls. This measure is called cortico-spinal excitability and is established by applying a electromagnetic pulse to the brain and measuring the size of the effect in a lower limb muscle. We predict that when there is (mild) traumatic brain injury the conductivity of the brain-to-muscle pathway in reduced. This reduction in cortico-spinal excitability could then be used as a marker for neural change, specifically relating to damage or brain injury. There is evidence that (amateur) football/soccer players may induce a form of mild brain injury through their ball heading practice with effects that can persist for a day or more. We will measure the cortico-spinal excitability before and after ball heading so that we can show whether there is actual neural change. Volunteers in this project will do ball heading in our lab by returning a ball projected at approximately 67 miles per hour. This speed is entirely in keeping with what players routinely do as part of their football practice and competition, reflecting our aim to examine the consequence of real-world behaviour. Changes to cortico-spinal excitability after ball heading in this project will also be related to 1) changes in postural balance (the ability to stand on one leg) which has also been shown to be affected by ball heading, and 2) changes to cognitive performance. If successful, our novel approach to the diagnosis of mild traumatic brain injury will significantly increase our ability to identify which routine behaviours are most damaging, and in turn, what can be done to reduce the impact of such damage.